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The aim of the study was to compare clinical and radiological outcomes between primary and aseptic revision TKAs using the same posterior-stabilised (PS) prosthesis. The authors hypothesised similar outcomes between both groups for selected patients. This retrospective, case–control study assessed 36 patients who underwent aseptic revision TKA compared to a match group of 72 primary TKA. Both groups had the same PS design implant (ANATOMIC®, Amplitude, Valence, France). The International Knee Society (IKS) score, radiological outcomes (postoperative alignment, patellar tilt and radiolucent lines), re-intervention and revision rate were compared between the two groups with a minimum follow-up of 3 years. The final study cohort included 29 patients and 63 patients respectively in the revision and primary group, with a mean follow-up of 49.1 months (range 36.1–69). Postoperatively, there was no significant difference in IKS scores between the two groups [169.8 for the revision group and 179.6 for the primary group (p = 0.09)]. No statistical difference was observed for post-operative satisfaction 86.2% versus 92.1% (p = 0.46). Between the two groups, there was no difference in mean radiological assessment, including radiolucent lines (p = 0.7). There was no significant difference for overall implant survivorship 96.5% versus 100% (p = 0.13) at 36 months. Similar clinical, radiological and survivorship outcomes were found between rTKA and primary TKA groups using the same PS level of constraint in patients undergoing revision surgery for aseptic indications at 3-year follow-up. Use of PS implants in rTKA for the correct indication suggests this to be a safe approach at least in the medium term. IV, retrospective case–control study.

The purpose of the study was to compare clinical and radiological results between kinematic alignment (KA) and mechanical alignment (MA) with a posterior-stabilized (PS) total knee arthroplasty (TKA) with a post-cam mechanism at a minimum follow-up of 3 years. The authors hypothesized a higher risk of aseptic loosening when performing KA using PS TKA. A retrospective monocentric single surgeon case control study was performed comparing 100 matched patients who had TKA performed using a MA philosophy to 50 patients receiving TKA with a KA technique between January 2016 and October 2017. All patients had the same knee prosthesis (GMK primary posterior-stabilized, Medacta®, Switzerland). Patient specific cutting blocks were used in both groups and a restricted KA (rKA) was aimed in the KA group. A hybrid cementation technique was performed. The new Knee Society Score (KSS) and radiological assessment were collected preoperatively and at the final follow-up. Comparisons between groups were done with the T test or Fisher exact test. Global survival curves were estimated with Kaplan–Meier model. Significance was set at p

In total knee arthroplasty (TKA), knee phenotypes including joint line obliquity are of interest regarding surgical realignment strategies. The hypothesis of this study is that better clinical results, including decreased postoperative knee pain, will be observed for patients with a restored knee phenotype. A retrospective analysis was performed on prospective data, including 1078 primary osteoarthritic knees in 936 patients. The male:female ratio was 780:298, mean age at surgery was 71.3 years ± 8.0. International Knee Society Scores and standardized long-leg radiographs (LLR) were collected preoperatively and at 2 years follow-up after TKA. Patients were categorized using the Coronal Plane Alignment of the Knee (CPAK) classification including the lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) measured on LLR by a single observer, allowing knee phenotypes to be categorized considering the arithmetic hip–knee–ankle (aHKA) angle (MPTA-LDFA) as measure of constitutional alignment, and joint line obliquity (JLO) (MPTA + LDFA). Clinical results were compared between patients with surgically restored preoperative constitutional knee phenotype to patients without restored constitutional knee phenotypes. Descriptive data analysis such as means, standard deviations and ranges were performed. T tests for independent samples were performed to compare group differences. Comparisons of categorical data were performed using the χ2 test. Significance was set at p

The aim of this systematic review was to compare relevant health economic consequences of the CT-based robotic-arm-assisted system versus conventional Uni-compartmental Knee Arthroplasty (UKA). In November 2020, A PRISMA systematic review was conducted using four databases (Pubmed, Scopus, Cochrane and Google Scholar) to identify all comparative studies reporting health economic assessments, such as robotic system costs, consumable costs, surgical revision rate, operating time, length of stay, and inpatient care costs. A total of nine comparative studies published between 2014 and 2020 were included in this systematic review. There was a moderate risk of bias as assessed using the ROBINS-I Tool. The CT-based robotic-arm-assisted system seemed to be associated with a lower risk of revision, decreased analgesia requirements during hospitalization, a shorter length of stay, and lower inpatient care costs compared to a conventional technique. CT-based robotic-arm-assisted system for UKA appears to be an economically viable solution with a positive health economic impact as it tends to decrease revision rate compared to conventional UKA, improve post-operative rehabilitation and analgesia management. Post-operative inpatient care costs seem lower with the robotic-assisted system but depend on institutional case volume and differ among health systems. More studies are needed to confirm cost-effectiveness of CT-based robotic-arm-assisted system based on different health systems. Systematic review, Level IV

Femorotibial alignment is crucial for the outcome of unicompartmental knee arthroplasty (UKA). Robotic-assisted systems are useful to increase the accuracy of alignment in UKA. However, no study has assessed if the femorotibial alignment measured by the image-free robotic system is reliable. The aim of this study was to determine whether measurement of the mechanical femorotibial axis (mFTA) in the coronal plane with handheld robotic assistance during surgery is equivalent to a static measurement on radiographs and to a dynamic measurement during walking. Twenty patients scheduled for robotic-assisted medial UKA using handheld technology were included in this prospective study. Three measurements of the frontal femorotibial axis were compared: intra-operative acquisition by computer assistance (dynamic, non-weightbearing position), radiographic measurements on long leg X-ray (static, weightbearing position), and by gait analysis during walking (dynamic, weightbearing position). There was no significant difference in the mFTA between computer (174.4 ± 3.4°), radiological (173.9 ± 3.3°), and gait analysis (172.9 ± 5.1°) measurements (p = 0.5). There was a strong positive correlation (r = 0.6577355, p = 0.0016) between robotic-assisted measurements and gait analysis. There was no significant difference in the femorotibial axis measured by the image-free robotic assistance, from the preoperative radiographs or by gait analysis. The reliability of intra-operative measurements of the frontal femorotibial axis by these robotic-assisted systems is acceptable.

There are increased surgical considerations when revising total knee arthroplasty (TKA) in active patients. Few studies have assessed if a semi-constrained [Total Stabilized (TS)] prostheses has similar knee biomechanics to a primary posterior stabilized (PS) prosthesis. The aim was to compare the gait parameters in patients with PS or TS TKA and normal controls. 32 patients with TKA were prospectively included with either a primary PS (n = 15) or a revision TS (n = 17) prosthesis. Gait analysis was performed at 6 months postoperatively for each patient, with an optoelectronic knee assessment device (KneeKG®) assessing the displacement of the tibia relative to the femur during the different gait phases (flexion/extension, anterior/posterior translation, adduction/abduction, internal/external rotation). A control group (n = 12) of healthy knees was compared with the TKA groups. There were no significant kinematic differences between PS and TS groups. The maximum knee flexion during gait was 53° ± 8.1° in the PS group vs 52° ± 8.7° in the TS group. The antero-posterior translation was similar in both group (2.3 ± 0.5 mm vs 2.6 ± 0.9 mm, respectively). Peak varus angle during loading and swing phase was slightly higher in the TS group (2.7° ± 0.7° and 5.2° ± 0.9°) than in the PS group (2.9° ± 0.6° and 5.6° ± 1.2°), without significant difference. The ranges in internal/external rotation were similar between PS and TS TKA (3.7° ± 0.5° vs 3.3° ± 0.6°, respectively). Both designs approached closely the normal gait patterns of the control group except in the frontal plane. Single radius TS TKA has gait parameters similar to single radius PS TKA. Use of a single radius TS TKA in revision TKA is not detrimental to a patient’s gait pattern. Both designs approached closely the normal gait patterns of the control group. Prospective, case–control study; Level III.

In recent studies, robotic-assisted surgical techniques for unicompartmental knee arthroplasty (UKA) have demonstrated superior implant positioning and limb alignment compared to a conventional technique. However, the impact of the robotic-assisted technique on clinical and functional outcomes is less clear. The aim of this study was to compare the gait parameters of UKA performed with conventional and image-free robotic-assisted techniques. This prospective, single-center study included 66 medial UKA, randomized to a robotic-assisted (n = 33) or conventional technique (n = 33). Gait knee kinematics was assessed on a treadmill at 6 months to identify changes in gait characteristics (walking speed, each degree-of-freedom: flexion–extension, abduction–adduction, internal–external rotation, and anterior–posterior displacement). Clinical results were assessed at 6 months using the IKS score and the Forgotten Joint Score. Implants position was assessed on post-operative radiographs. Post-operatively, the whole gait cycle was not significantly different between groups. In both groups, there was a significant improvement in varus deformity between the pre- and post-operative gait cycle. There was no significant difference between the two groups in clinical scores, implant position, revision, and complication rates. No difference of gait parameters could be identified between medial UKA performed with image-free robotic-assisted technique or with conventional technique. Prospective randomized controlled trial. Level of evidence I.

Background Predictive modeling promises to improve our understanding of what variables influence patient satisfaction after total knee arthroplasty (TKA). The purpose of this article was to systematically review the relevant literature using predictive models of clinical outcomes after TKA. The aim was to identify the predictor strategies used for systematic data collection with the highest likelihood of success in predicting clinical outcomes. Methods A Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol systematic review was conducted using 3 databases (MEDLINE, EMBASE, and PubMed) to identify all clinical studies that had used predictive models or that assessed predictive features for outcomes after TKA between 1996 and 2020. The ROBINS-I tool was used to evaluate the quality of the studies and the risk of bias. Results A total of 75 studies were identified of which 48 met our inclusion criteria. Preoperative predictive factors strongly associated with postoperative clinical outcomes were knee pain, knee-specific Patient-Reported Outcome Measure (PROM) scores, and mental health scores. Demographic characteristics, pre-existing comorbidities, and knee alignment had an inconsistent association with outcomes. The outcome measures that correlated best with the predictive models were improvement of PROM scores, pain scores, and patient satisfaction. Conclusions Several algorithms, based on PROM improvement, patient satisfaction, or pain after TKA, have been developed to improve decision-making regarding both indications for surgery and surgical strategy. Functional features such as preoperative pain and PROM scores were highly predictive for clinical outcomes after TKA. Some variables such as demographics data or knee alignment were less strongly correlated with TKA outcomes. Level of evidence Systematic review – Level III.

Patellar tracking problems represent 2–10% of complications of total knee arthroplasties (TKA) in valgus knees. However, there are no studies assessing patellar tracking according to the severity of the valgus deformity. The hypothesis was that lateral approach TKA in severe valgus deformity provides equivalent patellar tracking to that in knees with mild valgus deformity. Between 1988 and 2016, 77 TKAs were performed via a lateral approach on a severe valgus deformity (HKA > 195°). Forty-three TKAs performed without tibial tubercle osteotomy and with complete radiological data were included in this study. These were compared with 86 matched TKAs performed via a lateral approach with a mild valgus deformity (HKA between 181° and 190°). Patellar tilt and patellar position were assessed by axial view radiographs at the last follow-up. Complications and clinical outcomes were also evaluated. The follow-up was mean 52 ± 21 months in the severe valgus group. No significant differences were found between the severe valgus deformity group and the mild valgus deformity groups in patellar tilt (1.6° ± 6.6° versus 1.9° ± 3.2°, respectively) or patellar subluxation. There were complications in 12% (n = 5) and 11% (n = 9) of the severe valgus group and the mild valgus group respectively, without significant difference. There was no significant difference in extensor mechanism complication rate (2.3% versus 4.7%, respectively). Lateral parapatellar approach, without tibial tubercle osteotomy, for TKA in severe valgus deformity results in good patellar tracking. With this approach, the extensor mechanism complication rate in severe valgus deformity was not higher than for mild valgus deformity. III.

Reverse shoulder arthroplasty (RSA) is often indicated in elderly patients with displaced proximal humerus fractures (PHF). The rate of greater tuberosity (GT) healing varies from 37 to 90% in this population. The aim of this study was to assess greater and lesser tuberosity (LT) fixation and healing on CT scan after RSA for PHF. Our hypothesis was that both GT and LT healing leads to better functional results after RSA for fracture. Our retrospective cohort consisted of 28 patients treated with an RSA for a four-part PHF during the inclusion period. The mean age at surgery was 77 years. Clinical examination and CT scan were performed at a minimum one year follow-up to assess tuberosity position and healing. The GT healed in 22 patients (78.5%), the LT in 24 patients (87.5%) and both tuberosities were healed in 20 patients (71.5%). Constant score was significantly improved with GT, LT and both tuberosity healing (p = 0.05, p = 0.04 and p = 0.02 respectively). Motion in anterior elevation was improved with GT and both tuberosity healing (p = 0.01 and p = 0.04 respectively). Motion in external rotation was improved with GT and both tuberosity healing (p = 0.01 and p = 0.02 respectively). GT and LT healing was associated with better functional results and active motion. Anatomical reduction and consolidation of both tuberosities is beneficial with a cumulative effect for functional recovery.

Greater trochanter (GT) fractures affect 0.6–29% of patients after direct anterior approach (DAA) total hip arthroplasty (THA). Given the growing popularity of this approach, this study aimed to assess the evolution of the GT fractures during the learning curve, their risk factors and their consequences. 537 total hip arthroplasties were retrospectively included from May 2013 to December 2017 in a single academic centre. Patient characteristics, perioperative management, clinical consequences and postoperative radiographs were analysed. GT fractures represented 2.4% (n = 13) of the THA, and there was not a decrease with experience. The GT fracture patients did not require any additional support during the surgery, and full weight bearing was always allowed without any restriction. This complication only happened in females, with the risk significantly increased in those > 70 years old (OR = 4.9). There was no specific consequence during the follow-up, mean HHS score was 98.5 and all of the patients were satisfied or very satisfied postoperatively. Older osteoporotic women are known to be at risk for GT fracture during DAA THA. Those results reinforce the argument in favour of proper patient selection in DAA to lower the complications since it does not improve with surgeon’s experience. Retrospective, consecutive case series; Level IV.

Background The type of total knee arthroplasty (TKA) fixation (cemented or uncemented) is still subject to debate. The aim of this study is to assess the survival rate, clinical outcomes, and radiological results of TKA according to the fixation type. Methods A total of 130 patients were randomly assigned to either the cement group (cemented femoral and tibial implants) or the hybrid group (cemented tibial implant, uncemented femoral implant). The inclusion criteria were patients between 50 and 90 years old who underwent primary TKA for osteoarthritis between 2004 and 2005 without a history of open knee surgery. Revisions and complications were reported, as well as clinical scores and radiological signs of loosening. Results One hundred eighteen patients had complete data at 10 years of minimum follow-up (59 in each group). The mean age was 72 years old. The mean follow-up was 13 years. The survival rate was 98% at 13 years in both groups (1 aseptic loosening at 2 years in the cement group, 1 septic loosening in the hybrid group). The complication rate in the cement group was 8.5% (n = 5) vs 12.1% (n = 7) in the hybrid group (P = .8). The clinical results were not significantly different. In the cement group, 25% of patients (n = 15) had radiolucent lines at 10 years. In the hybrid group, 33% of patients had bone transparencies, not evolving or symptomatic. Conclusion At a minimum follow-up of 10 years, there were no significant differences between cemented TKA and hybrid TKA for the survivorship, the complication rate, the clinical scores, or the radiological signs of loosening. Level of Evidence I.

PURPOSE: Cup positioning is important for optimum hip stability, avoiding component impingement and decreasing both bearing surface wear and revision rate. Transitioning from posterior approach in a lateral position to direct anterior approach (DAA) in a supine presents unique challenges for surgeons. The aim of this study was to examine the learning curve when using standard instrumentation that was not specific to DAA. METHODS: A consecutive retrospective series of 537 total hip arthroplasty by DAA from May 2013 to December 2017. Cup positioning was analysed on radiographs and classified whether inside or outside two safe zones (inclination 30-50° and anteversion 10-30°). The demographic data (age, BMI, gender, neck shaft angle (NSA)), surgeon's dominant side and experience were assessed as risk factors. RESULTS: Eighty per cent of cups (n=426) were in the combined safe zones. Eighty-eight per cent (n=470) were in appropriate anteversion and 87% (n=463) abduction. Two factors that were significant were identified: Cups of left hips operated by right-handed surgeons were more anteverted (OR=4.06) and more vertical (OR=2.23); females had a higher anteversion of the cup (OR=2.42). Obesity, age and NSA were not risk factors for cup malposition. There was a spike of cups too horizontal at the beginning of the experience (OR=3.86), and no learning curve was observed in the other orientations. CONCLUSION: With our DAA technique using standard instrumentation, there were no risk factors linked to the patient identified for cup malposition. DAA-specific instrumentation is not required to achieve optimum positioning of the cup. Surgeon has to be aware of an excess of abduction at the beginning of his experience and an excess of anteversion and adduction when performing THA on the opposite side of his dominant hand.

The aim of this study was to evaluate the radiographic effect of sagittal tibial osteotomy (STO), flexion tibial osteotomy (FTO) and deflexion tibial osteotomy (DTO) around the knee. It has been hypothesized that proximal STO modifies patellar height and could cause varus/valgus changes of the anatomical tibial axis: The purpose of the study was to verify this and to analyse these modifications. Patients underwent proximal STO in our department between 2007 and 2018: overall 28 consecutive patients (19 males, 9 females; 28 knees). Twelve patients underwent DTO, and 16 patients underwent FTO. Two independent observers measured the pre-operative and post-operative radiological indexes: posterior tibial slope, Caton-Deschamps Index (CDI) and Modified Insall-Salvati Index (MISI) in the lateral views; medial Tibial Plateau-Tibial Shaft (mTPTS) and medial Femoral Shaft-Tibial Shaft (mFTA) anatomical angles were measured in the frontal plane. No complications were reported at the average follow-up of 1.6 ± 1.1 years. The mean mTPTS significantly increased from 0.6° ± 2.4° pre-operatively to 2.9° ± 2.6° of varus post-operatively (DTO (pre-operative 0.3 ± 3.1°, post-operative 2.4 ± 2.1°, ns); FTO (pre-operative 0.9 ± 1.9°, post-operative 3.2 ± 3.0°, P

Background: Arthroscopic anterior cruciate ligament (ACL) reconstruction (ACLR) with a bone–patellar tendon–bone graft (BTB) is a reliable surgical option for the control of anterior knee laxity after ACL injury. The addition of a lateral extra-articular tenodesis (LET) may improve control of rotation knee laxity and improve short-term graft survival in high-risk patients. Purpose: The aims of this study were to compare long-term patient-reported outcomes, graft survival, and risk of osteoarthritis between ACLR with and without LET. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: This study included 121 consecutive knees (120 patients) presenting to a single center with an ACL rupture between 1998 and 1999. In total, 61 knees were randomized to an isolated BTB ACLR, and 60 knees were randomized to a BTB ACLR with an extra-articular lateral tenodesis with gracilis tendon (modified Lemaire). Results: Eighty knees in 79 patients (66%) were available for follow-up at a postoperative mean of 19.4 years (range, 19-20.2). Of those patients, 43 had a clinical examination and completed patient-reported outcome questionnaires, and the other 37 patients were evaluated through the questionnaires alone. Standard radiographs were available for 45 patients and laximetry (TELOS) for 42 patients. Mean subjective International Knee Documentation Committee score at last follow-up was 81.8, and no differences were noted between the BTB and BTB-LET groups ( P = .7). Two-thirds of patients were still participating in pivoting sports. A total of 17 knees (21%) experienced a graft failure, 5 of which (6%) underwent revision ACLR. There was no significant difference in graft failure risk between the BTB group (29%) and the BTB-LET group (13%; P = .1). Lateral tibiofemoral osteoarthritis was significantly more frequent in the BTB-LET group (59%) as compared with the BTB group (22%; P = .02). Lateral compartment osteoarthritis was correlated with partial lateral meniscectomy. Conclusion: There were no significant differences in long-term patient-reported outcomes after ACLR with or without an LET. LET may increase the risk of lateral compartment osteoarthritis at long-term follow-up. There was a trend toward decreased graft failure risk with the addition of LET but this study was underpowered to assess this outcome.

Background Revision total hip arthroplasty (rTHA) is a challenging surgery with a higher rate of complications than primary arthroplasty, particularly instability and aseptic loosening. The purpose of this study is to compare dual mobility cup (DMC) and standard mobility cup (SMC) in all rTHAs performed at our institution over a decade with a 1 year minimum follow-up. Methods Two hundred ninety-five rTHAs (acetabular only and bipolar revisions) between 2006 and 2016 were retrospectively reviewed. These were divided into those with a DMC (184 revisions) or SMC (111 revisions). Dislocation and complications requiring re-revision were reported. Results The rTHA mean age was 69 years ± 13.9 (19-92) and the mean follow-up was 2.3 years. Dislocation risk was statistically lower (P = .01) with a DMC (3.8%; 7/184) than with an SMC (13.5%; 15/111). DMC required re-rTHA in 24/184 (13%) for any reason compared to SMC in 19/111 (17.1%) (P = .34). There was no significant difference in early aseptic loosening (P = .28) between the 2 groups. For young patients (≤55 years), results were similar with a lower dislocation rate in the DMC group (P = .24) and no increased risk of early aseptic loosening (P = .49). Conclusion This study demonstrates that for all rTHA indications DMC compared to SMC has a significantly decreased risk of postoperative dislocation without risk of early aseptic loosening at medium term follow-up. The use of DMC in rTHA is an important consideration particularly with the predicted increased incidence of both primary and revision THA globally.

Introduction: Management of chronic infection following total knee arthroplasty (TKA) is challenging. Rotating hinged prostheses are often required in this setting due to severe bone loss, ligamentous insufficiency, or a combination of the two. The nature of the mechanical and septic complications occurring in this setting has not been well-described. The aim of this study was to evaluate patient outcomes using a hinge knee prosthesis for prosthetic knee infections and to investigate risk factors for implant removal.Methods: This was a retrospective cohort study that included all patients treated in our tertiary level referral center between January 2009 and December 2016 for prosthetic knee infection with a hinge knee prosthesis. Only patients with a minimum 2-year of follow-up were included. Functional evaluation was performed using international knee society (IKS) “Knee” and “Function” scores. Survival analysis comparing implant removal risks for mechanical and septic causes was performed using Cox univariate analysis and Kaplan-Meier curves. Risk factors for implant removal and septic failure were assessed.Results: Forty-six knees were eligible for inclusion. The majority of patients had satisfactory functional outcomes as determined by mean IKS scores (mean knee score: 70.53, mean function score: 46.53 points, and mean knee flexion: 88.75°). The 2-year implant survival rate was 89% but dropped to 65% at 7 years follow-up. The risk of failure (i.e., implant removal) was higher for septic etiology compared to mechanical causes. Patients with American society of anesthesiologists (ASA) score>1, immunosuppression, or with peripheral arterial diseases had a higher risk for septic failure. Patients with acute infection according to the Tsukayamaclassification had a higher risk of failure. Of the 46 patients included, 19 (41.3%) had atleast one infectious event on the surgical knee and most of these were superinfections (14/19) with new pathogens isolated. Among pathogens responsible for superinfections (i) cefazolin and gentamicin were both active in six of the cases but failed to prevent the superinfection; (ii) cefazolin and/or gentamicin were not active in eight patients, leading to alternative systemic and/or local antimicrobial prophylaxis consideration.Conclusions: Patients with chronic total knee arthroplasty (TKA) infection, requiring revision using rotating hinge implant, had good functional outcomes but experienced a high rate of septic failure, mostly due to bacterial superinfection. These patients may need optimal antimicrobial systemic prophylaxis and innovative approaches to reduce the rate of superinfection.

Introduction Bone and Joint Infections (BJI) are medically important, costly and occur in both native and prosthetic joints. Arthroplasties are expected to increase significantly in absolute numbers over time as well as the incidence of Prosthetic Joint Infections (PJI). Diagnosis of BJI and PJI is generally sub-optimal. The available diagnostic tests have variable effectiveness, are often below standard in sensitivity and/or specificity and carry a significant contamination risk during the collection of clinical samples. Improvement of diagnostics is urgently needed. Areas covered : We here provide a narrative review on current and future diagnostic microbiology technologies. Pathogen identification, antibiotic resistance detection and assessment of the epidemiology of infections via bacterial typing is considered useful for improved patient management. We here confirm the continuing importance of culture methods and the successful introduction of molecular, mass spectrometry-mediated and next generation genome sequencing technologies. The diagnostic algorithms for BJI must be better defined, especially in the context of the diversity of both disease phenotypes and clinical specimens rendered available. Expert opinion : Whether interventions in BJI or PJI are surgical or chemo-therapeutic (antibiotics and bacteriophages included), prior sensitive and specific pathogen detection remains a therapy-designing necessity. Innovative tests for earlier and more sensitive and specific detection of bacterial pathogens in BJI are urgently needed.

The purpose of this study was to compare the clinical results, radiographic loosening and early complications between patients undergoing primary knee arthroplasty (TKA) with tibial short stem extension and those with standard stem for gross varus deformities at minimum two years after surgery.From a prospective TKA database of 4216 patients, patients with a primary TKA with a tibial short stem extension (30 mm) for severe varus deformity (hip-kneeankle angle, HKA 170°) and a minimum follow-up of 2 years, were reviewed and compared to a matched control group with tibial components with a standard stem, in a 1:3 ratio. Demographics, surgical parameters, pre- and postoperative alignment and outcome parameters were collected for all patients. The primary outcome was aseptic loosening of the tibial component. Secondary outcomes were knee society scores (KSS), postoperative HKA, general postoperative complications and implant survival rates.Forty-five patients with tibial short stem extensions (mean HKA 166.2°) were compared in a 1:3 ratio to a matched case-control group of 135 patients with standard stems (mean HKA 167.1°) at a mean follow-up of 57 and 64 months respectively after primary TKA. In the extension stem group, 4 patients encountered complications (8.9%) versus 12 patients in the standard stem group (8.9%). There were no cases of tibial component loosening in the short extension stem versus four cases in the standard stem group (3%). This difference was significant between groups, p = 0.04.In patients with varus deformities 10°, undergoing primary total knee arthroplasty, prophylactic use of a tibial short extension stem may lead to less loosening of the tibial component. In this study, 3% of patient with big varus deformity without stemmed TKA had a tibial implant loosening versus 0% in the stemmed TKA group.Level III, case-control study.

Background Total hip arthroplasty (THA) is currently performed on active patients with increasing functional demands. Single stage bilateral THA is indicated in younger patients in good general health. Our objective is to evaluate the return to sport (RTS) in patients who underwent bilateral single stage THA compared to unilateral THA. Methods This retrospective case control study was conducted between 2013 and 2017. All patients who underwent bilateral single stage THA were included. The control group had unilateral THA performed and was matched based on age, body mass index, gender, and surgery date (2 controls for each bilateral case). All surgeries were performed by a single senior surgeon using the direct anterior approach. The University of California Los Angeles activity score was collected at the last follow-up. A questionnaire regarding RTS, motivation, and satisfaction was assessed. Results Thirty-two patients were included in the study, of whom 21 were men. The average age was 60.7 ± 9.6 years, body mass index was 26 ± 4 kg/m2, and mean follow-up was 20.1 ± 11.6 months. Twenty-eight patients overall (87%) returned to sport after the procedure. Twenty-five of these (89%) returned to the same sport, and 17 (68%) participated at the same intensity. The average time to RTS was 4 ± 2.8 months. These results were at least as good as those after unilateral THA. The level of motivation of the patient was the only predictive factor for RTS (P Conclusion Bilateral single stage THA via a direct anterior approach allows for RTS and to a similar level in the majority of patients in whom this procedure is indicated. Level of Evidence Comparative retrospective study, Level III.

Background Survivorship of lateral unicompartmental knee arthroplasty (UKA) has progressively improved. However, there are few studies describing long-term results, and no study reports on polyethylene (PE) wear in lateral unicompartmental arthroplasty. The aims of this study are to determine the survival rate of lateral UKA with a fixed, all-PE bearing, and the PE wear of the tibial implant at a minimum of 15 years follow-up. Methods From January 1988 to October 2003, we performed 54 lateral UKAs in 52 patients. All patients had isolated lateral osteoarthritis (OA). The mean age at the index procedure was 65.4 ± 11 years. Thirty-nine UKAs were available for follow-up (30 alive and 9 dead after 15 years). Twelve patients had died before 15 years and 3 patients were lost to follow-up. The mean follow-up was 17.9 years (range, 15-23 years). Results At the final follow-up, 8 knees of 39 (20.5%) had a surgical revision. The cumulative survival rate was 82.1% at 15 years and 79.4% at 20 years. The main reason of revision was progression of OA (87.5%), followed by aseptic loosening of the tibial component (12.5%). With a mean follow-up of 17.9 years, the mean PE wear was 0.061 mm/y. There was no radiographic loosening in the surviving implants and no revisions for wear. The mean functional International Knee Society score was 66.5 ± 26.8, with a mean objective score of 84.4 points ± 13.2. In the population without revision, 90.5% were satisfied or very satisfied at the latest follow-up. Conclusion Lateral UKA with a fixed, all-PE tibial bearing and a femoral resurfacing implant presents a high survivorship at long term, with very low PE wear.

Patella infera is an uncommon but potentially crippling pathology of the knee, resulting in stiffness and anterior knee pain. Several surgical methods have been described for its treatment, but there remains no clear technique of choice. We present the case of a 63-year-old male with patella infera, affecting a native knee, following Complex Regional Pain Syndrome. This patient was treated with a combined technique of Patellar Tendon lengthening and partial Hourglass Extensor Mechanism Allograft reconstruction. The results were excellent at 24 months of follow-up. To our knowledge, this technique has not yet been published, and we present it as a promising treatment option in selected cases.

PURPOSE Recurrent patellar dislocation is a frequent knee disorders in young, active patients. Medial patellofemoral ligament reconstruction (MPFLR) can restore knee stability and function, but the rate of return to sports is less clear. The aim of this study was to evaluate rate of return to sport following treatment of recurrent patellar dislocation with isolated MPFLR. METHODS Between 2011 and 2018, 113 patients with recurrent patellar dislocation were treated with isolated MPFLR at an academic center. Pre-injury sports participation and Tegner score, pre-operative subjective IKDC score, time to return to sports, and post-operative Tegner and subjective IKDC scores were collected, with a minimum of follow-up of 2 years. RESULTS One hundred and three patients (91%) were evaluated at a mean of 4.5 ± 2.5-year post-operative. 92 patients (89%) participated in sports prior to onset of patellar instability. At final follow-up, 84 of these 92 patients (91%) were able to return to sports. The mean time from surgery to return to sports was 10.4 ± 8.6 months (range: 2-48 months). 62 patients (67%) returned to the same (50 patients) or higher (12 patients) level. 22 patients (26%) returned at a lower level. 19 of these patients attributed this decreased participation to ongoing knee problems. The median Tegner score was noted to decrease from 5 pre-injury to 4 post-operatively (p = 0.02). CONCLUSION Isolated MPFL reconstruction allowed return to pre-injury sports in 91% of patients, with 67% of patients returning to the same or higher level than pre-injury. Mean time to return to sports was 10 months and post-operative Tegner score was noted to be modestly decreased from pre-injury level. LEVEL OF EVIDENCE IV.

Purpose: This study aimed to evaluate whether there are any differences in outcomes and complication rates between condylar constrained knee (CCK) and rotating hinge knee (RHK) prostheses used for the first revision of total knee arthroplasty (rTKA) after mechanical failure. Methods: Sixty-three consecutive non-septic revisions of posterior stabilized implants using 33 CCK and 30 RHK prostheses were included. Clinical evaluation and revision rate were compared between the two groups at two years minimum follow-up. Results: The CCK group had significantly better clinical outcomes and satisfaction rates compared to patients with RHK (KSS-knee 70.5 versus 60.7 (p p p = 0.03). The postoperative flexion was significantly better in the CCK group compared to the RHK group (115° vs. 103°, p = 0.01). The prosthesis-related complications and the re-revision rate were higher in the RHK group, especially due to patellofemoral complications and mechanical failures. Conclusions: CCK prostheses provided better clinical and functional outcomes and fewer complications than RHK prostheses when used for the first non-septic rTKA. CCK is a safe and effective implant for selected patients, while RHK should be used with caution as a salvage device for complex knee conditions, with particular attention to the balance of the extensor mechanism.

Bacteriophages are viruses that specifically target bacteria. They are considered to have a high potential in patients with prosthetic joint infection (PJI), as they have a synergistic anti-biofilm activity with antibiotics. We report here the case of an 88-year-old man (63 kg) with relapsing Pseudomonas aeruginosa prosthetic knee infection. The patient had severe alteration of the general status and was bedridden with congestive heart failure. As prosthesis explantation and/or exchange was not feasible, we proposed to this patient the use of phage therapy to try to control the disease in accordance with the local ethics committee and the French National Agency for Medicines and Health Products Safety (ANSM). Three phages, targeting P. aeruginosa, were selected based on their lytic activity on the patient's strain (phagogram). Hospital pharmacist mixed extemporaneously the active phages (initial concentration 1 ml of 1 × 1010 PFU/ml for each phage) to obtain a cocktail of phages in a suspension form (final dilution 1 × 109 PFU/ml for both phages). Conventional arthroscopy was performed and 30 cc of the magistral preparation was injected through the arthroscope (PhagoDAIR procedure). The patient received intravenous ceftazidime and then oral ciprofloxacin as suppressive antimicrobial therapy. Under this treatment, the patient rapidly improved with disappearance of signs of heart failure and pain of the left knee. During the follow-up of 1 year, the local status of the left knee was normal, and its motion and walking were unpainful. The present case suggests that the PhagoDAIR procedure by arthroscopy has the potential to be used as salvage therapy for patients with P. aeruginosa relapsing PJI, in combination with suppressive antimicrobial therapy. A Phase II clinical study deserves to be performed to confirm this hypothesis.

Background Prosthetic joint infections (PJI) are one of the most serious complication of arthroplasty. The management of PJI needs a multidisciplinary collaboration between orthopaedic surgeon, infectious disease specialist and microbiologist. In France, the management of PJI is organized around reference centres (CRIOACs). Our main objective was to perform an audit through a questionnaire survey based on clinical cases, to evaluate how French physicians manage PJI. Eligible participants were all physicians involved in care of patients presenting a PJI. Physicians could answer individually, or collectively during a multidisciplinary team meeting dedicated to PJI. The survey consisted as three questionnaires organized in a total of six clinical cases. Results Answers from the CRIOACs to the three questionnaires were 92, 77, and 53%. Between 32 and 39% of respondents did not administer antibiotic prophylaxis despite positive S. aureus pre-operative documentation. One-stage exchange strategy was widely preferred in all clinical cases, with no difference between CRIOACs and other centres. Rifampicin was prescribed for S. aureus PJI, in a situation with (90–92%) or without any prosthesis (70%). There was no consensus for the total antibiotic regimen duration, with prescriptions from six to 12 weeks for a majority of respondents. Conclusions Surgical strategy for the management of PJI was homogenous with a preference for a one-stage exchange strategy. Medical management was more heterogenous, which reflects the heterogeneity of those infections and difficulties to perform studies with strong conclusions.

Exebacase, a recombinantly produced lysin has recently (i) reported proof-of-concept data from a phase II study in S. aureus bacteremia and (ii) demonstrated antibiofilm activity in vitro against S. epidermidis. In patients with relapsing multidrug-resistant (MDR) S. epidermidis prosthetic knee infection (PKI), the only surgical option is prosthesis exchange. In elderly patients who have undergone several revisions, prosthesis explantation could be associated with definitive loss of function and mortality. In our BJI reference regional center, arthroscopic debridement and implant retention with local administration of exebacase (LysinDAIR) followed by suppressive tedizolid as salvage therapy is proposed for elderly patients with recurrent MDR S. epidermidis PKI with no therapeutic option or therapeutic dead end (for whom revision or transfemoral amputation is not feasible and no other oral option is available). Each use was decided in agreement with the French health authority and in accordance with the local ethics committee. A written consent was obtained for each patient. Exebacase (75 mg/mL; 30 mL) was administered directly into the joint during arthroscopy. Four patients (79–89 years old) were treated with the LysinDAIR procedure. All had several previous prosthetic knee revisions without prosthesis loosening. Three had relapsing PKI despite suppressive antibiotics following open DAIR. Two had clinical signs of septic arthritis; the two others had sinus tract. After the LysinDAIR procedure, no adverse events occurred during arthroscopy; all patients received daptomycin 8 mg/kg and linezolid 600 mg bid (4–6 weeks) as primary therapy, followed by tedizolid 200 mg/day as suppressive therapy. At 6 months, recurrence of the sinus tract occurred in the two patients with sinus tract at baseline. After >1 year follow up, the clinical outcome was favorable in the last two patients with total disappearance of clinical signs of septic arthritis even if microbiological persistence was detected in one of them. Exebacase has the potential to be used in patients with staphylococci PKI during arthroscopic DAIR as salvage therapy to improve the efficacy of suppressive antibiotics and to prevent major loss of function.

There is a growing interest in the potentially deleterious impact of antibiotics on gut microbiota. Patients with bone and joint infection (BJI) require prolonged treatment that may impact significantly the gut microbiota. We collected samples from patients with BJI at baseline, end of antibiotics (EOT), and 2 weeks after antibiotic withdrawal (follow-up, FU) in a multicenter prospective cohort in France. Microbiota composition was determined by shotgun metagenomic sequencing. Fecal markers of gut permeability and inflammation as well as multi-drug-resistant bacteria (MDRB) and Clostridioides difficile carriage were assessed at each time point. Sixty-two patients were enrolled: 27 native BJI, 14 osteosynthesis-related BJI, and 21 prosthetic joint infections (PJI). At EOT, there was a significant loss of alpha-diversity that recovered at FU in patients with native BJI and PJI, but not in patients with osteosynthesis-related BJI. At EOT, we observed an increase of Proteobacteria and Bacteroidetes that partially recovered at FU. The principal component analysis (PCoA) of the Bray–Curtis distance showed a significant change of the gut microbiota at the end of treatment compared to baseline that only partially recover at FU. Microbiota composition at FU does not differ significantly at the genus level when comparing patients treated for 6 weeks vs. those treated for 12 weeks. The use of fluoroquinolones was not associated with a lower Shannon index at the end of treatment; however, the PCoA of the Bray–Curtis distance showed a significant change at EOT, compared to baseline, that fully recovered at FU. Levels of fecal neopterin were negatively correlated with the Shannon index along with the follow-up (r2 = 0.17; p < 0.0001). The PCoA analysis of the Bray–Curtis distance shows that patients with an elevated plasma level of C-reactive protein (≥5 mg/L) at EOT had a distinct gut microbial composition compared to others. MDRB and C. difficile acquisition at EOT and FU represented 20% (7/35) and 37.1% (13/35) of all MDRB/C. difficile-free patients at the beginning of the study, respectively. In patients with BJI, antibiotics altered the gut microbiota diversity and composition with only partial recovery, mucosal inflammation, and permeability and acquisition of MDRB carriage. Microbiome interventions should be explored in patients with BJI to address these issues.

Background: In prosthetic joint infections (PJIs), identification of the causative microorganisms is critical to successfully adapt and optimize treatment. However, microbiological diagnosis of PJIs remains a challenge notably because bacteria are embedded in biofilm adhered to the prosthetic material. Recently, dithiothreitol (DTT) treatment of prosthesis has been proposed as a new strategy to release bacteria from biofilm and to improve the yield of microbiological diagnosis. In this study, we evaluated the interest of a commercial device using DTT, the MicroDTTect system (Heraeus, Hanau, Germany), for the diagnosis of low-grade chronic PJIs, compared to the conventional culture of periprosthetic tissue (PPT) samples.Methods: Twenty patients undergoing a surgery procedure for removal of prosthetic material because of a suspicion of low-grade PJI without pre-operative microbiological documentation were included (NCT04371068). Bacteriological results using the fluid obtained after prosthesis treatment with the MicroDTTect system were compared to results obtained with conventional culture of PPT samples.Results: All the bacteria considered as responsible for PJIs recovered from culture of PPT samples were also detected using the MicroDTTect device. For one patient, an additional bacterial isolate (Staphylococcus haemolyticus) suspected to be involved in a polymicrobial PJI was identified using DTT treatment. Time to positivity of the cultures was also reduced using the MicroDTTect system, notably in case of Cutibacterium acnes infection. However, probable bacterial contaminants were found (MicroDTTect system, n = 5; PPT samples, n = 1).Conclusion: This study showed that DTT treatment of the prosthetic component using the MicroDTTect device could improve the microbiological diagnosis of low-grade PJIs.

Sensors have been introduced within the last 10 years to quantify soft tissue balancing during total knee arthroplasty (TKA) and to give the surgeon objective data. These devices are fairly new and their impact on patient outcome remains uncertain. The aim of this systematic review was to summarize all the relevant surgical and clinical results of sensors for TKA. A PRISMA systematic review was conducted using five databases (PubMed, EMBASE, MEDLINE, GOOGLE SCHOLAR, and the COCHRANE LIBRARY) to identify all available literature that described the surgical and clinical results of sensors for TKA between 2000 and 2021. The main investigated outcome criteria were intraoperative data, postoperative functional and clinical outcome, knee range of motion, complications and revision rates. Twenty-seven articles were finally included. The maximum reported follow-up was 26 months. A balanced knee with sensor corresponded to a mediolateral difference inferior to 15 lb and a stable posterior drawer test. The standard assessment of knee balance was a poor predictor of the true soft tissue balance when compared to sensor data. At least 60% of TKA needed an additional rebalancing procedure with the sensor, after conventional gap balancing. Achieving a quantitatively balanced knee resulted in a significantly higher patient satisfaction score. But the prospective comparative studies found no demonstrable improvement in clinical outcome, range of motion or complication rate at one year postoperatively for patients undergoing TKA using sensor-guided balancing compared with routine techniques. Even though the use of the intraoperative sensing technology was not related to an improvement in clinical outcome, the current studies showed that using sensors facilitates the reproduction of natural joint stability, and improves the rate of achieving a balanced knee. Sensor use in complex cases could be particularly valuable, but their use in standard practice remains to be defined.

Place: France; International audience; INTRODUCTION: In patients aged over-50 years, although data are sparse, results of anterior cruciate ligament (ACL) surgery are good if selection is correctly performed. However, non-operative treatment is usually proposed for this age group, as patients generally prefer just to scale down their sports activities. Non-operative results are acceptable, but with a high risk of residual instability, secondary lesions and lifestyle alteration. The main aim of the present study was to compare results between surgical versus non-surgical treatment of ACL tear in over-50 year-olds. Secondary objectives comprised assessing prognostic factors for poor functional outcome, and comparing the 2 groups epidemiologically to identify clinical decision-making factors. The study hypothesis was that results are comparable between operative and non-operative treatment of ACL tear.MATERIAL AND METHOD: Three hundred twenty patients were followed up prospectively: 92 non-surgical (NS group) and 288 surgical (S group). Classical epidemiological data were collected. Clinical laxity, differential laximetry, KOOS, IKDC, Tegner and ACL-RSI scores and radiologic assessment were collected pre- and postoperatively, as were intraoperative data. Early and late complications were collected.RESULTS: All patients were followed up. Patients were principally female, and were older, less athletic, with more stable knee and less severe functional impact in the NS group. Functional scores improved in both groups, and especially in group S, where sports scores were also better. In the NS group, laximetry at follow-up correlated with preoperative marked pivot-shift (p=0.024). Severe differential laxity was predictive of poor IKDC score (p=0.06). In the S group, laximetry at follow-up correlated with preoperative explosive pivot-shift (p\textless0.001), lateral meniscal lesion (p=0.007), use of hamstring tendon (p=0.007), and non-operated early complications (p=0.004). Factors for poor global KOOS score in group S comprised female gender (p\textless0.001), high BMI (p\textless0.001) and skiing (p=0.038). Factors for poor Tegner scores comprised skiing or team sport (p\textless0.05), isolated moderate medial osteoarthritis (p=0.01), and non-operated early complications (p=0.022). Factors for poor IKDC score comprised female gender (p=0.064), and non-operated early complications (p=0.019). Complications did not differ between groups. DISCUSSION/CONCLUSION: Results were satisfactory in both groups, with significant improvement in functional scores, but were better in group S. For NS patients, pivot sport was barely feasible and sports activity scores decreased. In case of severe laxity at diagnosis, surgical treatment should be proposed.LEVEL OF EVIDENCE: III; non-randomized prospective comparative series

Introduction: One of the principal complications after total knee arthroplasty (TKA) is stiffness. There are no publications concerning stiffness after unicompartmental knee arthroplasty (UKA). Study objectives were to describe the incidence of stiffness after UKA, to look for risk factors, and to describe safe and effective arthroscopic treatment. Methods: There were 240 UKA performed between March 2016 and January 2019 included. Robotic-assisted surgery was performed in 164 patients and mechanical instrumentation in 76 patients. Stiffness was defined as flexion < 90° or a flexion contracture > 10° during the first 45 post-operative days. Patients with stiffness were treated with arthroscopic arthrolysis. Several factors were studied to look for risk factors of stiffness: body mass index, gender, age, mechanical or robotic instrumentation, preoperative flexion, previous meniscectomy, and anticoagulant treatment. Arthrolysis effectiveness was evaluated by flexion improvement and UKA revision rate. Results: 22 patients (9%) developed stiffness. Mechanical instrumentation significantly increased the risk of stiffness with OR = 0.26 and p = 0.005. Robotic-assisted surgery decreased the risk of stiffness by five-fold. Before arthrolysis, mean knee flexion was 79°, versus 121° (53% improvement) after arthroscopic arthrolysis. Only 2 patients (9%) underwent UKA revision after arthrolysis. Discussion: Stiffness after UKA is an important complication with an incidence of 9% in this study. Arthroscopic arthrolysis is a safe and effective treatment with a range of motion improvement of > 50%. Robotic-assisted surgery significantly decreases the risk of postoperative stiffness. Level of evidence: Level III, therapeutic study, retrospective cohort study

Objective: Chronic prosthetic joint infections (PJI) are serious complications in arthroplasty leading to prosthesis exchange and potential significant costs for health systems, especially if a subsequent new infection occurs. This study assessed the cost of chronic PJI managed with 2-stage exchange at the Lyon University Hospital, CRIOAc Lyon reference center, France. A threshold analysis was then undertaken to determine the reimbursement tariff of a hypothetical preventive device usable at the time of reimplantation, which possibly enables health insurance to save money according to the risk reduction of subsequent new infection. This analysis was also performed for a potential innovative device already available on the market, a dual antibiotic loaded bone cement used to fix cemented prosthesis that releases high concentrations of gentamicin and vancomycin locally (G+V cement).Method: Patients >18 years, admitted for a hip or knee chronic PJI managed with 2-stage exchange, between January 1, 2013, and December 31, 2015, were retrospectively identified. Following, resource consumption in relation to inpatient hospital stay, hospitalization at home, rehabilitation care, outpatient antibiotic treatments, imaging, laboratory analysis, and consultations were identified and collected from patient records and taken into account in the evaluation. Costs were assessed from the French health insurance perspective over the 2 years following prosthesis reimplantation.Results: The study included 116 patients (median age 67 y; 47% hip prosthesis). Mean cost of chronic PJI was estimated over the 2 years following prosthesis reimplantation at €21,324 for all patients, and at €51,697 and €15,745 for patients with (n = 18) and without (n = 98) a subsequent new infection after reimplantation, respectively. According to the threshold analysis the reimbursement tariff (i) should not exceed €2,820 for a device which can reduce the risk of a new infection by 50% and (ii) was between €2,988 and €3,984 if the G + V cement can reduce the risk of a new infection by 80% (this reduction risk is speculative and has to be confirmed by clinical trials).Conclusion: This study revealed that chronic PJI requiring a 2-stage revision is costly, with significant costs in relation to the reimplantation procedure (about 15 k€). However, following reimplantation the rate of subsequent new infection remained high, and the cost of reimplantation following a new infection is considerable, reaching 50k€ per patient. These first cost estimates of managing chronic PJI with 2-stage exchange in France underline the economic interest of preventing new infections.

Background Genu recurvatum is a rare knee deformity. Total knee arthroplasty (TKA) in severe preoperative recurvatum requires surgical adjustments. Few studies have assessed the clinical and radiological results of TKA in recurvatum. The aim was to compare the clinical and radiological outcomes, complications, and revision rates after posterior-stabilized TKA in severe recurvatum with those without recurvatum. Methods Between 1987 and 2015, 32 primary posterior-stabilized TKA were performed with a preoperative genu recurvatum greater than 10° and minimum follow-up of 60 months. In severe genu recurvatum, the extension gap needs to be decreased compared with flexion gap. To achieve this, the distal femoral cut is distalized, whereas the posterior femoral and tibial cuts are performed as usual. They were compared with 64 matched posterior-stabilized TKAs without recurvatum. The demographic data were similar between groups. The clinical and radiological outcomes, complications, and revision rates were assessed at the last follow-up. Results At a mean follow-up of 7.4 years ± 1.9, there was no significant difference in International Knee Score functional score (77.5 vs. 73.4; P = .50) and knee score (86.6 vs. 89.5; P = .37) between the recurvatum group and the control group, respectively. 6 patients had a postoperative recurvatum equal or superior to 10° in the recurvatum group (18.8%). There was no difference between both groups in radiological outcomes, complication, or revision rates. No instability was found in the recurvatum group. Conclusion Posterior-stabilized TKA with controlled distalization of the femoral component in the setting of severe preoperative genu recurvatum achieves good clinical and radiological outcomes at a minimum follow-up of 5 years and similar to TKA without preoperative recurvatum. Level of Evidence III.

Objectives: To report the management of three consecutive patients with relapsing Staphylococcus aureus prosthetic knee infection (PKI) for whom explantation was not feasible who received a phage therapy during a “Debridement Antibiotics and Implant Retention” (DAIR) procedure followed by suppressive antimicrobial therapy. Methods: Each case was discussed individually in our reference center and with the French National Agency (ANSM). The lytic activity of three phages targeting S. aureus, which was produced with a controlled and reproducible process, was assessed before surgery (phagogram). A hospital pharmacist extemporaneously assembled the phage cocktail (1 ml of 1 × 1010 PFU/ml for each phage) as “magistral” preparation (final dilution 1 × 109 PFU/ml), which was administered by the surgeon directly into the joint, after the DAIR procedure and joint closure (PhagoDAIR procedure). Results: Three elderly patients were treated with the PhagoDAIR procedure. Phagograms revealed a high susceptibility to at least two of the three phages. During surgery, all patients had poor local conditions including pus in contact to the implant. After a prolonged follow-up, mild discharge of synovial fluid persisted in two patients, for whom a subsequent DAIR was performed showing only mild synovial inflammation without bacterial persistence or super-infection. The outcome was finally favorable with a significant and impressive clinical improvement of the function. Conclusions: The PhagoDAIR procedure has the potential to be used as salvage for patients with relapsing S. aureus PKI, in combination with suppressive antibiotics to avoid considerable loss of function. This report provides preliminary data supporting the setup of a prospective multicentric clinical trial.

Background While many studies have reported the outcomes of open mosaicplasty, data on arthroscopic mosaicplasty are scarce. Only two cadaver studies have compared arthrotomy and arthroscopy. Moreover, the patello-femoral joint, which is the main donor site, has never been assessed using a specific functional score. The objective of this in vivo study was to compare arthrotomy and arthroscopy for mosaicplasty using both a global functional knee score and a specific score of the patello-femoral joint. Hypothesis The arthroscopic technique results in better functional patello-femoral outcomes. Material and methods We retrospectively compared two groups of 17 patients who underwent mosaicplasty for focal condylar cartilage defects, at our department between 2009 and 2019. Functional outcomes were assessed using the Kujala score and the Lysholm score, at least 1 year after surgery. The return to sports was assessed using the Tegner score. Results Mean follow-up was 67.4 ± 15.9 months in the arthrotomy group and 45.2 ± 35.1 months in the arthroscopy group (p Discussion This is the first clinical study comparing arthrotomy and arthroscopy for mosaicplasty. Clinical outcomes were good with both techniques. The proportion of patients with excellent Lysholm and Kujala functional scores was significantly higher in the arthroscopy group than in the arthrotomy group. This result may be ascribable to decreased donor-site morbidity obtained with arthroscopy. Level of evidence IV, retrospective observational comparative study.

Owing to the improved understanding of knee kinematics and the successful introduction of the kinematic alignment (KA) technique for implanting total knee arthroplasty (TKA), it was recently understood that the “Cartier angle technique” corresponds to a kinematic implantation of the uni-compartmental knee arthroplasty (UKA) components. When compared to the universally spread mechanical alignment (MA) technique for implanting UKA, the KA method generates a more anatomic prosthetic knee that may be clinically advantageous. The aims of this study are to determine if KA UKAs are associated with acceptable functional performance and patient satisfaction (question 1), rates of residual pain and tibia plateau fracture (question 2), and rates of reoperation and revision (question 3), and to define the component orientation and limb alignment as measured on radiograph (question 4), and the stress shielding related bone loss in the proximal tibia (question 5) with KA UKA, and where possible to compare with MA UKA. KA UKA generates good clinical outcomes, similar or superior to the ones of MA UKA. Systematic review of literature databases were primarily searched using Healthcare Databases Advanced Search (HDAS). Two primary searches were conducted using the electronic databases MEDLINE, EMBASE, and PubMed, and a secondary search was conducted using review articles and bibliography of obtained papers in order to ascertain more material. Nine eligible non-comparative prospective (3) or retrospective (6) cohort studies, which cumulated 593 KA UKAs with follow-up between 3.2 and 12 years, fulfilled the inclusion criteria for this systematic review. The findings demonstrated high Knee Society Score (KSS) (from 87 to 95) and function scores (from 81 to above 91) in addition to patient satisfaction scores of 88%. There was no revision for tibia plateau fracture, 0.8% (5 cases) for unexplained pain tibia, 2.0% (12 cases) for component loosening, and 5.6% (33 cases) for any causes of aseptic failures reported for KA UKA. The prosthetic lower limb and tibia implant alignments were both found to be in slight varus (means between 3 and 5°), and the postoperative joint line and tibia component was shown to be parallel to the floor when standing. The KA UKA components migration, as measured on radiostereometry, was acceptable. The KA technique is an alternative, personalised, more physiological method for implanting UKA, which could be clinically advantageous when compared to the MA technique. The literature supports the good mid- to long-term clinical safety and good efficacy of KA UKA; however, comparison between KA and MA techniques for UKA was not performed due to limited literature. Further investigations are needed to better define the clinical impact of KA UKA, and the acceptable limits for KA of the UKA tibial component. Level 4; systematic review of level 4 studies.

PURPOSE: Very few studies focus on lateral unicompartmental arthroplasty (LUKA) in the setting of post-traumatic osteoarthritis (PTOA). The hypothesis of our study is that LUKA is an effective procedure for isolated lateral PTOA with similar outcomes to non-traumatic LUKA. METHODS: Between 1990 and 2016, eighteen LUKA performed for isolated lateral tibiofemoral osteoarthritis secondary to tibial plateau fracture were retrospectively reviewed (post-traumatic group) and matched with a control group of thirty-six LUKA performed for non-traumatic OA. Clinical (International Knee Score), radiological outcomes and revision rate were compared between the two groups with a minimum follow-up of three years. RESULTS: With a mean follow-up of 10.1years, postoperative IKS scores were similar between the two groups (IKS Knee: 89.1 (control) versus 85 (p=0.03) and IKS Function: 85.9 (control) versus 77.9 (n.s.). Clinical improvement was greater for the post-traumatic group. No difference was observed with regard to revision rate (3/18 (16.7%) cases in the post-traumatic group and 7/36 (19.4%) in the control group, n.s.) or polyethylene wear per year between the two groups. The revision free-survival rate was 64.8% for the post-traumatic group and 58.8% for the control group at 22-year follow-up (n.s.). CONCLUSION: LUKA is an effective procedure at long-term for patients suffering from isolated lateral PTOA with similar clinical and radiographic results compared to LUKA performed for non-traumatic OA and without increased risk of revision or prosthetic wear. LEVEL OF EVIDENCE: IV.

Infection is the most dramatic complication in patients with knee megaprosthesis. Its management is more complex in comparison with patients with primary arthroplasty, with a high risk of relapse. Lytic bacteriophages are considered to have a high potential in patients with prosthetic joint infection as it has been demonstrated that they have a synergistic anti-biofilm activity with antibiotics. The Defensive Antibacterial Coating (DAC®) hydrogel is a hydrogel available in the market that has been designed to prevent the adherence of bacteria on a prosthetic joint and to have the ability to transport and release anti-bacterial substances such as antibiotics. We report here the case of a patient with a catastrophic relapsing Staphylococcus aureus knee megaprosthesis infection without prosthesis loosening. We firstly perform phage susceptibility testing of the patient's strain to select an active cocktail, under the supervision of the French health authority. Then, we performed, as salvage therapy, a debridement and implant retention procedure with application of a selected cocktail of bacteriophages that was prepared extemporaneously within the DAC® hydrogel. A free flap for soft tissue coverage was required and empirical antibiotic treatment was started immediately after the surgery. Unfortunately, at 5 days after the surgery, while the local aspect of the surgical site was favorable, the patient developed myocardial infarction which required emergency stenting and dual antiplatelet therapy that were rapidly associated with bleeding at the surgical site, leading to a new prosthesis exposition. As a consequence, a transfemoral amputation was finally performed several months later. We also evaluated in vitro the impact of DAC® hydrogel on bacteriophage activity and showed that the selected phages were released very rapidly from the DAC® hydrogel, and then their titers were stable for at least 6 h. This case demonstrated the feasibility of the use of bacteriophages within a hydrogel to treat patients for knee megaprosthesis infection during a debridement procedure. The implementation requires identification of the pathogen before the debridement in order to perform phage susceptibility testing of the patient's strain and to identify a hospital pharmacist who will accept to do the preparation and to take the responsibility of the magistral preparation.

Purpose: The aim of this study was to perform a systematic review of the literature to determine whether there are any clinical or radiological differences in mechanically aligned Total Knee Arthroplasty (TKA) compared with kinematically aligned TKA.Methods: This study included retrospective cohort studies, prospective randomized controlled trials (PRCTs) and prospective cohort studies comparing clinical and radiological outcomes, and complications in TKA with kinematic alignment (KA) and mechanical alignment (MA). All studies had a minimum follow-up of 2 years.Results: Five PRCTs published between 2014 and 2020 were included. These studies showed a low risk of bias and were of very high quality. We did not find a superiority of KA compared to MA technique for clinical and radiological outcomes, except in one study which showed a significant difference favoring KA between the two groups for all clinical scores.Conclusion: We found that KA in TKA achieved clinical and radiological results similar to those of MA. The complication rate was not increased for KA TKAs. Studies with longer follow-up and larger cohorts are required to prove any benefit of KA technique over MA technique.

PURPOSE: Several studies report satisfactory clinical outcomes following ACLR in older patients, but none evaluated the effects of meniscal and cartilage lesions. The aim was to evaluate the influence of meniscal and cartilage lesions on outcomes of ACLR in patients aged over 50years. METHODS: The authors prospectively collected records of 228 patients that underwent primary ACLR, including demographics, time from injury to surgery, whether injuries were work related, and sports level (competitive, recreational, or none). At a minimum follow-up of 6months, knee injury and osteoarthritis outcome scores (KOOS), International Knee Documentation Committee (IKDC) score and Tegner activity level were recorded, and differential laxity was measured as the side-to-side difference in anterior tibial translation (ATT) using instrumented laximetry devices. Regression analyses were performed to determine associations between outcomes and meniscal and cartilage lesions as well as nine independent variables. RESULTS: A total of 228 patients aged 54.8?±?4.3years at index ACLR were assessed at a follow-up of 14.3?±?3.8months. KOOS subcomponents were 85?±?13 for symptoms, 91?±?10 for pain, 75?±?18 for daily activities, 76?±?18 for sport, and 88?±?12 for quality of life (QoL). The IKDC score was A for 84 (37%) knees, B for 96 (42%) knees, C for 29 (13%) knees, and D for 8 (4%) knees. Tegner scores showed a decrease (median 0, range -4 to 4) and differential laxity also decreased (median - 4, range - 23.5 to 6.0). KOOS symptoms worsened with higher BMI (p?=?0.038), for women (p?=?0.007) and for knees that had medial meniscectomy (p?=?0.029). KOOS pain worsened with higher BMI (p???0.001), for women (p?=?0.002) and for knees with untreated (p?=?0.047) or sutured (p?=?0.041) medial meniscal lesions. Differential laxity increased with follow-up (p?=?0.024) and in knees with lateral cartilage lesions (p?=?0.031). CONCLUSION: In primary ACLR for patients aged over 50years, female gender and medial meniscal lesions significantly compromised KOOS symptoms and pain, while lateral cartilage lesions significantly increased differential laxity. Compared to knees with an intact medial meniscus, those with sutured or untreated medial meniscal lesions had worse pain, while those in which the medial meniscus was resected had worse symptoms. These findings are clinically relevant as they could help surgeons with patient selection and adjusting expectations according to their functional demands. LEVEL OF EVIDENCE: III.

Introduction: Distal Femoral Osteotomy (DFO) is a common procedure for correcting lower limb valgus deformity and lateral compartment overload. Low 20-year survivorship rate was reported with a consequent need for total knee arthroplasty (TKA). This study aims to review literature and to analyse the influence of a previous distal femoral osteotomy on outcomes of patients undergoing TKA.Methods: A systematic literature review was performed in PubMed/Medline and Embase in May 2020. Papers were selected based on the following criteria: patient with a previous distal femoral osteotomy; total knee replacement; Pre- and Postoperative outcomes; surgical outcomes: clinical scores, range of motion, radiographic evaluation and revisions for any cause; case series, retrospective studies, observational studies, open-label studies, randomized clinical trials; systematic reviews and meta-analyses were included to extract primitive studies.Results: 306 articles were found, of which five papers were considered eligible for this review. In every study included, postoperative clinical outcomes (Knee Society Score or Hospital for Special Surgery score) statistically improved from the preoperative. Complications were not uncommon; implant survivorship at the available follow-up seems to be similar to primary TKA, although being too short to draw any conclusions.Conclusions: Limited and highly heterogeneous evidence is currently available on the influence of DFO on outcomes after TKA. Knee replacement improves clinical middle-term outcomes in patients with previous distal femoral osteotomy. In this complex surgery, the use of technical tips and tricks could help surgeons to obtain an accurate knee balancing and better long-term results.

The epidemiology of meniscal lesions in stable knee has been a focus of study, but exact topography is not clearly known. Tear patterns are thought to differ between pathologies and the difference between a traumatic and a degenerative pattern is not always easy to draw. In 2010, ISAKOS designed a questionnaire to standardize assessment. The main objective of present study was to detail the precise topography and type of surgical meniscal patterns (i.e., that were operated on) in stable knee. Secondary objectives were to assess the relationship of tear pattern and cartilage lesions in the tibiofemoral compartment, and to analyze age at onset.The study hypotheses were that tear pattern correlates with cartilage lesions, and that mean age differs according to tear pattern, with younger onset of vertical tears, in surgery@ patients.Data collection for this descriptive epidemiological study was prospective, on systematic ISAKOS questionnaire. 1424 isolated meniscal tears in stable knee, operated on between 2010 and 2017, were included: 253 lateral meniscus (LM), and 1171 medial meniscus (MM). Mean age at surgery was respectively 36 and 47 years.The most frequent tear pattern was vertical (39% in LM, 38% in MM). The more frequent locations were posterior+midpart and midpart (22% each) in LM, and posterior in MM (56%). Tears were mainly peripheral (zone 1) in LM (46%), and zone 2 in MM (46%). Mean age in medial vertical tears was 43±14 years, significantly lower (p0.001) than in other types. Meniscal tear pattern correlated significantly with medial tibiofemoral cartilage lesion (p0.001).The present study described the precise topography of isolated meniscal tears in stable knee in a large sample, using the ISAKOS questionnaire. The study hypotheses were confirmed for the medial but not the lateral meniscus.III; well-conducted non-randomized prospective comparative study.

PURPOSE: Surgeons mainly consider the anterior anatomy of the distal femur in the treatment of patellar instability (PI) with trochlear dysplasia (TD). Through this research, the idea was to analyse the posterior femoral condyle length in TD. The research team posited the presence of morphological differences in the posterior part of the femoral epiphysis in TD compared to a control group. They also postulated that the posterior bicondylar angle (PCA), in the axial plane, was increased in TD. METHODS: This is a single-centre morphological study of 100 patients who had a computed tomography (CT) using the same protocol. 50 patients with PI (25 dysplasias A and 25 B-C-D according to the Dejour classification), and 50 controls were included. All patients presenting a clinical PI were considered for the study. None of these patients had undergone a surgical treatment prior to imaging. Demographic characteristics, BMI, and laterality were comparable in all patients. 20 pilot CT scans were used to establish the methodology. The following measurements were performed: anterior bicondylar angle, PCA, and condylar lengths with respect to the surgical transepicondylar axis. Ratios were calculated in relation to the femoral width. TD was classified according to the Dejour classification in grade A or grades B-C-D. An analysis of variance and a linear model were performed within some groups to investigate which parameters correlated with the classification's grade. RESULTS: This study showed a link between TD and the PCA: control group (1.4?±?0.2°), type A group (1.6?±?0.3°), and types B, C, D group (2.6?±?0.3°) (p?=?0.01). The difference between the control group and types B, C, D TD group was significant (p?=?0.002). In groups B, C, D, the PCA was more important, which proves that in these groups the posterior part of the lateral condyle was relatively shorter compared to the medial condyle. The greater the dysplasia, the longer the medial condyle was in the anterior posterior (p?=?0.02). CONCLUSIONS: This study shows not only an anterior but also a posterior anomaly in PI with TD. There is a correlation between the severity of the anterior deformation and the PCA: in other words, the knee is placed in valgus in flexure which promotes the external dislocation of the patella. This anatomical study could open a field of research on the development of surgical treatments based on the correction of posterior condylar femoral anomalies in PI. LEVEL OF EVIDENCE: III.

International audience; OBJECTIVE: The long-term impact of treatment strategies proposed by the IDSA guidelines for patients presenting with methicillin-susceptible S. aureus (MSSA) prosthetic joint infection (PJI) is not well-known. PATIENTS AND METHODS: Retrospective (2000-2010) cohort study including patients presenting with MSSA hip or knee PJI. A univariate Cox analysis was performed to determine if the non-compliance with IDSA surgical guidelines was a risk factor for treatment failure. RESULTS: Eighty-nine patients with a mean follow-up of 2.8 years were included. Non-compliance with IDSA surgical guidelines was associated with treatment failure (hazard ratio 2.157; 95% CI [1.022-4.7]). The American Society of Anesthesiologists score, inadequate antimicrobial therapy, and a rifampicin-based regimen did not significantly influence patient outcome. CONCLUSION: Based on the IDSA guidelines, if a patient presenting with MSSA PJI is not eligible for implant retention, complete implant removal is needed to limit treatment failure.