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Background: Total talus replacement (TTR) implants are designed to replace the diseased talar anatomy, reduce pain, maintain ankle range of motion, and restore ankle function after conservative treatments have failed. Currently TTR implants are produced by 3D printing a patient-specific implant designed from the patient’s preoperative anatomy. TTR surgery using patient-specific implants is a relatively new technique that remains understudied in the literature. Therefore, the purpose of this investigation was to determine the early safety and potential benefit of the TTR implant in patients with talar avascular necrosis.Methods: This retrospective, multicenter, cohort study evaluates the safety and potential benefits of TTR using 3D-printed patient-specific implants across 4 US centers. The primary outcome was the occurrence of early adverse events after TTR surgery. Secondary outcomes including, pain, and physical function were assessed using the pain visual analog scale (VAS), and Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF), respectively.Results: The study team analyzed 15 patients with more than 1 year of follow-up. The mean duration of follow-up was 25.9 months (range: 18.3-41 months). Although 33.3% (5 of 15) of patients experienced adverse events, primarily occurring within the initial 6 months postoperatively, 93% (14 of 15) of patients reported implant survivorship. Of the 5 cases (33.3%) resulting in an adverse event, 3 (60.0%) were determined to be unrelated to the subject device, 2 (40.0%) were determined to be possibly procedure-related, and none (0%) were determined to be device-related.Conclusion: Although further studies are needed to compare TTR with the standard of care, the results of this study demonstrate the relative early safety of TTR surgery using a 3D-printed implant for the treatment of challenging talar pathologies. A larger and longer clinical study is required to see if the efficacy of this approach will be statistically and clinically meaningful.

Lesser metatarsophalangeal joint (MTPJ) instability is a common cause of metatarsalgia and is associated with plantar plate pathology. The instability is often due to chronic attenuation and attritional changes of the plantar plate and collateral ligaments, leading to eventual rupture. The plantar plate and collateral ligaments serve as the primary stabilizers of the MTPJ, and rupture or attenuation of these ligaments leads to instability. Surgical intervention is often necessary for plantar plate tears, with various approaches and techniques available.

Background: Despite substantial increase in total ankle arthroplasty (TAA) nationwide, there are few studies comparing flat-cut vs chamfer-cut talar systems in TAA with regard to radiographic aseptic loosening rates of the implant.Methods: This retrospective study included 189 Salto-Talaris TAA and 132 INBONE II primary TAA with a minimum 1-year follow-up. Patient characteristics were obtained including gender, age at surgery, body mass index (BMI), smoking status, primary diagnosis, surgical time, and the presence of diabetes. Radiographic evidence for aseptic loosening was assessed. Statistical analysis was performed for comparison in outcomes between Salto-Talaris and INBONE II.Results: The mean age of the study population was 63.5 ± 9.8 years at surgery. Mean follow-up was 4.9 ± 3.0 years. Radiographic aseptic loosening of the tibial implant showed no significant difference between the 2 groups: Salto-Talaris, 18%, and INBONE II, 18.9% (P= .829). Aseptic loosening of the talar implant also showed no significant difference between the 2 groups: Salto-Talaris, 1.6%, and INBONE II, 1.5% (P= .959). No variables, including the implant type, were found to contribute to the aseptic loosening rate of either the tibia or talus.Conclusion: In our cohort, we observed no difference in radiographic implant aseptic loosening between Salto-Talaris and INBONE II systems.Level of Evidence: Level IV, retrospective case series study.

Lineage transitions are a central feature of prostate development, tumourigenesis and treatment resistance. While epigenetic changes are well known to drive prostate lineage transitions, it remains unclear how upstream metabolic signalling contributes to the regulation of prostate epithelial identity. To fill this gap, we developed an approach to perform metabolomics on primary prostate epithelial cells. Using this approach, we discovered that the basal and luminal cells of the prostate exhibit distinct metabolomes and nutrient utilization patterns. Furthermore, basal-to-luminal differentiation is accompanied by increased pyruvate oxidation. We establish the mitochondrial pyruvate carrier and subsequent lactate accumulation as regulators of prostate luminal identity. Inhibition of the mitochondrial pyruvate carrier or supplementation with exogenous lactate results in large-scale chromatin remodelling, influencing both lineage-specific transcription factors and response to antiandrogen treatment. These results establish reciprocal regulation of metabolism and prostate epithelial lineage identity.

Background: Infection is a serious complication of primary total ankle arthroplasty (TAA) and can lead to implant failure and revision surgery. Various demographic, comorbidity, and surgical factors have been associated with an increased risk of infection. However, the evidence base remains limited, and further research is needed regarding infection in TAA. This study aims to analyze risk factors of infection and explore outcomes following infected TAA.Methods: A retrospective cohort study was conducted using data from a single institution from 2002 to 2022. Patients who underwent primary TAA and had subsequent infection were identified through annual registry surveillance and matched using propensity score matching (PSM) based on various demographic, comorbidity, and surgical factors. Demographics were compared between the matched groups using Mann-Whitney Utest and Fisher exact test. The outcomes following infection were identified and summarized using descriptive statistics.Results: A total of 1863 patients who underwent primary TAA were identified, and 19 were diagnosed with an infection. The identifiable overall infection rate was 1.0%. After PSM, there were no significant differences in the difference in age, gender, BMI, and smoking status between the infected and control cohort. There was a statistically significant increase in the rate of diabetes in the infected cohort. The subsequent surgical intervention resulted in limb salvage in 18 (94.7%) cases. Out of the total number of cases, 2-stage revision to total ankle replacement was performed in 7 cases, whereas revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. One patient had to undergo amputation; however, at the time of the most recent follow-up, all patients were found to be free of infection.Conclusion This study demonstrated high rates of a history of smoking and diabetes in the infected TAA cohort. The diabetes rate in the infected group was significantly higher than the noninfected controls. Two-stage revision to total ankle replacement was performed in 7 cases, and revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. Overall, a high rate of limb salvage was reported.Level of Evidence: Level III, case-control study.

Spine surgeons are often faced with a profoundly difficult challenge in surgically treating adult degenerative scoliosis. Deformity correction surgery is complicated by the difficulty in offering extensive surgical corrections to the elderly, complication-prone population it commonly affects. As spine surgeons attempt to offer minimally invasive solutions to this disease process, the need for fusion of the fractional curve at L4, L5, and S1 may be discounted. A treatment strategy to identify, address, and treat the fractional curve with either open or minimally invasive techniques can lead to improved patient outcomes and decrease revision rates in this complicated pathologic process.

Background: There is limited data evaluating the effect of obesity on outcomes following total ankle arthroplasty (TAA), especially in adequate sample sizes to detect impacts on patient-reported outcomes (PROs). The purpose of this study was to assess the effect of obesity on complication rates and PROs.Methods: This was a single-institution, retrospective study of 1093 primary TAA performed between 2001 and 2020. Minimum follow-up was 2 years. Patients were stratified by body mass index (BMI) into control (BMI = 18.5-29.9; n = 615), obesity class I (BMI = 30.0-34.9; n = 285), and obesity class II (BMI > 35.0; n = 193) groups. Patient information, intraoperative variables, postoperative complications, and PRO measures were compared between groups using univariable statistics. Multivariable Cox regression was performed to assess risk for implant failure. Mean follow-up was 5.6 years (SD: 3.1).Results: Compared to control and class I, class II patients had the lowest mean age (P= .001), highest mean ASA score (P< .001), and greatest proportion of female sex (P< .001) and Black/African American race (P= .005). There were no statistically significant differences in postoperative complications (infection, implant failure, or impingement) across the BMI classes (P> .05). Preoperatively, class II had lower (worse) mean scores for Foot and Ankle Outcome Score pain and ADL subscales than controls (post hoc pairwise P< .001 for both). At final follow-up, both class II and class I had lower (worse) mean Short Musculoskeletal Function Assessment (post hoc pairwise P< .001 and P= .030, respectively) and 36-Item Short Form Health Survey scores (post hoc pairwise P< .001 and P= .005, respectively) than controls.Conclusion: At midterm follow-up, obesity was not associated with increased rates of complications after TAA. Patients with obesity reported worse musculoskeletal function and overall quality of life after TAA but there was no differential improvement in PROs across BMI classes. To our knowledge, this is the largest single-institution study to date examining the effect of obesity on outcomes after primary TAA.Level of Evidence: Level III, retrospective comparative study.

There is increasing recognition that pathogenic germ line variants drive the development of hematopoietic cancers in many individuals. Currently, patients with hereditary hematologic malignancies (HHMs) receive similar standard therapies and hematopoietic stem cell transplant (HSCT) approaches as those with sporadic disease. We hypothesize that patients with myeloid malignancies and deleterious germ line predisposition variants have different posttransplant outcomes than those without such alleles. We studied 472 patients with myeloid neoplasms, of whom 26% had deleterious germ line variants and 34% underwent HSCT. Deleterious germ line variants in CHEK2 and DDX41 were most commonly seen in American and Australian cohorts, respectively. Patients with deleterious germ line DDX41 variants had a higher incidence of severe (stage 3-4) acute graft-versus-host disease (GVHD) (38%) than recipients with deleterious CHEK2 variants (0%), other HHM variants (12%), or patients without such germ line variants (9%) (P = .002). Importantly, the use of posttransplant cyclophosphamide reduced the risk of severe acute GVHD in patients receiving HSCT for deleterious germ line DDX41-associated myeloid neoplasms (0% vs 53%, P = .03). Based on these results, we advocate the use of posttransplant cyclophosphamide when individuals with deleterious germ line DDX41 variants undergo allogeneic HSCT for myeloid malignancies, even when transplantation has been performed using wild-type donors.

Background: End-stage ankle arthritis is a debilitating condition often necessitating total ankle replacement (TAR). Tendo-Achilles lengthening (TAL) and gastrocnemius recession (GR) are commonly performed with TAR to improve ankle dorsiflexion (DF). No studies to date have radiographically analyzed tibiopedal motion to guide surgical management. The purpose of this study is to determine the effect of a TAL or GR during TAR on radiographic tibiopedal range of motion (ROM).Methods: A retrospective review of a prospectively maintained database was conducted followed by a propensity score–matched analysis of 110 patients who underwent TAL (n = 26), GR (n = 29), or no lengthening procedure (n = 55) with TAR. Minimum of 1-year ROM radiographic follow-up was required. Exclusion criteria included (1) calcaneal osteotomies, (2) simultaneous or previous hindfoot or midfoot arthrodesis, (3) prior ankle arthrodesis, or (4) revision TAR. Demographic data were extracted from the TAR database. Radiographic assessment included tibiopedal dorsiflexion (DF) and plantarflexion (PF).Results: DF improved by 2.8 degrees (P= .0286) and by 6.0 degrees (P< .0001) in the TAL and GR cohorts, respectively, with no difference in the control group (+0.7 degrees, P= .3764). PF was decreased by 4.5 degrees (P= .0152) and by 7.2 degrees (P= .0002) in the TAL and GR cohorts, respectively, with no difference in the control group (–0.2 degrees, P= .8546). Minimal differences were observed for total arc of motion for all 3 groups (control 0.5 degrees, GR –1.2 degrees, TAL –1.7 degrees), all of which were nonsignificant (all P> .05). There was no between-group difference in the change in overall arc of motion between the groups (P= .3599). GR resulted in a greater increase in DF (6.0 vs 2.8 degrees; P= .1074), with a reciprocal greater decrease in PF (7.2 vs 4.5 degrees; P= .2416) compared with the TAL cohort.Conclusion: Both TAL and GR increased postoperative DF; however, this was accompanied by a reciprocal loss in PF. Minimal differences were observed for total arc of motion. Patients should be counseled that concomitant procedures performed to increase DF will do so at the expense of PF.Level of Evidence: Level III, retrospective review of prospectively collected data.

2D materials have intriguing quantum phenomena that are distinctively different from their bulk counterparts. Recently, epitaxially synthesized wafer-scale 2D metals, composed of elemental atoms, are attracting attention not only for their potential applications but also for exotic quantum effects such as superconductivity. By mapping momentum-resolved electronic states using time-resolved and angle-resolved photoemission spectroscopy (ARPES), we reveal that monolayer Ag confined between bilayer graphene and SiC is a large gap (>1 eV) 2D semiconductor, consistent with ab initio GW calculations. The measured valence band dispersion matches the GW quasiparticle band structure. However, the conduction band dispersion shows an anomalously large effective mass of 2.4 m0. Possible mechanisms for this large enhancement in the “apparent mass” are discussed.

The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on “Pediatric Ankle Cartilage Lesions” developed at the 2019 International Consensus Meeting on Cartilage Repair of the Ankle.

Background: In cases of large osteochondral lesions of the talus (OLTs), fresh structural or bulk osteochondral allograft transplantation has yielded favorable outcomes in several retrospective and few prospective case series. The purpose of this study was to prospectively evaluate patients who received fresh structural allograft transplantation of the talar shoulder.Methods: A prospective evaluation of patients who received a fresh structural allograft of an OLT was performed. Preoperative imaging included magnetic resonance imaging (MRI) and/or computed tomography (CT) with plain radiographs. The following patient-reported outcomes questionnaires were administered preoperatively and yearly after surgery: 36-Item Short-Form Health Survey (SF-36), visual analog scale (VAS) for pain, and the Short Musculoskeletal Functional Assessment (SMFA). Preoperative and postoperative imaging were evaluated for allograft assimilation, evidence of arthritic changes, or functional range of motion abnormalities.Results: Thirty-one patients with a mean age of 41.4 years (±14.1, range 18-69) underwent structural fresh osteochondral allograft transplantation to the talar shoulder and were included in this study. The mean follow-up was 56.2 months (±36.1, range 24-142). The majority of patients were female (n=17, 54.8%), reported some history of prior ankle trauma (n=21, 67.7%), and underwent prior ankle surgery (n=23, 74.2%). The mean lesion size on CT scan was 1879 mm3(n = 27) compared to the mean lesion size of 3877 mm3(n = 21) on MRI. There was a significant improvement in the mean preoperative VAS score (P< .0001), SF-36 score (P< .0005), SMFA bother index (P< .0015), and the SMFA function index (P< .0001) at final follow-up. A total of 15 (48.4%) patients underwent an additional surgery following their osteochondral allograft transplant, most commonly arthroscopic debridement or removal of hardware, performed at an average of 25.2 (±13.0) from their index procedure. There was one failure that required a total ankle replacement. The overall graft survival rate was 96.8%.Conclusion: Fresh, structural allograft transplantation resulted in significant improvement in patient-reported postoperative pain and function in patients suffering from OLTs. The graft survival rate was 96.8% at a mean of 56.2 months follow-up, with half of patients requiring a second procedure.Level of Evidence: Level IV, prospective case series.

The evidence supporting best practice guidelines in the field of cartilage repair of the ankle is based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on “terminology for osteochondral lesions of the ankle” developed at the 2019 International Consensus Meeting on Cartilage Repair of the Ankle.

Background: An international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to present the consensus statements on osteochondral lesions of the tibial plafond (OLTP) and on ankle instability with ankle cartilage lesions developed at the 2019 International Consensus Meeting on Cartilage Repair of the Ankle.Methods: Forty-three experts in cartilage repair of the ankle were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 4 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed on in unanimous fashion within the working groups. A final vote was then held.Results: A total of 11 statements on OLTP reached consensus. Four achieved unanimous support and 7 reached strong consensus (greater than 75% agreement). A total of 8 statements on ankle instability with ankle cartilage lesions reached consensus during the 2019 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support, and seven reached strong consensus (greater than 75% agreement).Conclusion: These consensus statements may assist clinicians in the management of these difficult clinical pathologies.Level of Evidence: Level V, mechanism-based reasoning.

Background: As the incidence of primary total hip arthroplasty (THA) continues to increase, revision THA (rTHA) is becoming an increasingly common procedure. rTHA is widely regarded as a more challenging procedure, with higher complication rates and increased medical, social and economic burdens when compared to its primary counterpart. Given the complexity of rTHA and the projected increase in incidence of these procedures, patient optimisation is becoming of interest to improve outcomes. Anaesthetic choice has been extensively studied in primary THA as a modifiable risk factor for postoperative outcomes, showing favourable results for neuraxial anaesthesia compared to general anaesthesia. The impact of anaesthetic choice in rTHA has not been studied previously.Methods: A retrospective study was performed using the American College of Surgeons National Surgical Quality Improvement Program database. Patients who underwent rTHA between 2014 and 2017 were divided into 3 anaesthesia cohorts: general anaesthesia, neuraxial anaesthesia, and combined general-regional (neuraxial and/or peripheral nerve block) anaesthesia. Univariate and multivariate analyses were used to analyse patient characteristics and 30-day postoperative outcomes. Bonferroni correction was applied for post-hoc analysis.Results: In total, 5759 patients were identified. Of these, 3551 (61.7%) patients underwent general anaesthesia, 1513 (26.3%) patients underwent neuraxial anaesthesia, and 695 (12.1%) patients underwent combined general-regional anaesthesia. On multivariate analysis, neuraxial anaesthesia was associated with decreased odds for any-one complication (OR 0.635; p<0.001), perioperative blood transfusion (OR 0.641; p<0.001), and extended length of stay (OR 0.005; p= 0.005) compared to general anaesthesia.Conclusions: Relative to those receiving general anaesthesia, patients undergoing neuraxial anaesthesia are at decreased risk for postoperative complications, perioperative blood transfusions, and extended length of stay. Prospective controlled trials should be conducted to verify these findings.

Background: Navicular stress fractures are becoming increasingly more common. There is no universal consensus on treatment. We provide an algorithm that we feel will be useful in determining treatment.Methods: A retrospective study was performed on all patients having operative treatment of navicular stress fractures during a 10-year period. Acute fractures were treated with open reduction internal fixation. Chronic fractures greater than 3 months were treated with open reduction and internal fixation (ORIF) and iliac crest bone grafting. Chronic fractures with evidence of sclerosis, avascular changes, or those who failed previous surgery were treated with ORIF, iliac crest bone grafting, as well as vascular bone grafting. Patients’ pain scores were recorded and a return-to-sports scale was used. Radiographic union was compared among the 3 groups using computed tomographic (CT) scans or radiographs.Results: Forty-three patients were identified. Fifteen received ORIF alone, 12 were treated with ORIF and bone graft, and 16 had ORIF with vascularized bone grafting. No difference was found among the median age of the 3 groups. In terms of radiographic healing, 3 patients in the ORIF group received radiographs alone. All other patients had follow-up CT scans. ORIF alone group had 80% union, ORIF with bone graft had 75% union, and ORIF with vascularized bone grafting had 100% union. Return to sports did not show any difference among the 3 groups.Conclusion: The algorithm dividing navicular stress fractures into 3 distinct groups with different operative techniques helped us address these difficult cases. Vascularized bone grafting certainly appeared to be beneficial for the more difficult cases.Level of Evidence: Level IV, case series.

The execution strategy of technical dance movements is constrained by aesthetic and qualitative artistic requirements. As such, there are limited leap-landing strategies that may be used by dancers when executing a grand jeté or saut de chat. The purpose of this study was to determine potential differences in lower extremity angular positioning and joint loading when performing a dance-style leap landing. Fifteen female dancers (age: 20 ± 1 years; height: 1.61 ± 0.13 m; weight: 58.00 ± 11.89 kg) completed six leap-landing trials during which three-dimensional kinematics and kinetics data were collected. Paired-samples t-tests (a = 0.05) and Cohens d effect sizes (ES; large > 0.8) were used to compare the following variables: jump height; peak vertical ground reaction force; loading time; loading rate; joint angular positioning of the ankle, knee, hip, and trunk in the frontal and sagittal planes; and joint angular impulse of the ankle, knee, and hip in the frontal and sagittal planes between the dominant and non-dominant limbs. Frontal plane hip angular impulse was significantly greater in the dominant limb (p = 0.023, ES = 1.53). While no other statistically significant differences were observed between dominant and non-dominant limbs, moderate effect sizes were observed for the hip and trunk angles in the frontal plane along with hip impulse in the sagittal plane. This study indicates that dancers might slightly alter their landing strategy at the hip joint when leap-landing onto the dominant limb. Frontal plane hip mechanics should be considered to minimize overuse injury potential in the dominant limb.

AimsIntra-articular administration of antibiotics during primary total knee arthroplasty (TKA) may represent a safe, cost-effective strategy to reduce the risk of acute periprosthetic joint infection (PJI). Vancomycin with an aminoglycoside provides antimicrobial cover for most organisms isolated from acute PJI after TKA. However, the intra-articular doses required to achieve sustained therapeutic intra-articular levels while remaining below toxic serum levels is unknown. The purpose of this study is to determine the intra-articular and serum levels of vancomycin and tobramycin over the first 24 hours postoperatively after intra-articular administration in primary cementless TKA.MethodsA prospective cohort study was performed. Patients were excluded if they had poor renal function, known allergic reaction to vancomycin or tobramycin, received intravenous vancomycin, or were scheduled for same-day discharge. All patients received 600 mg tobramycin and 1 g of vancomycin powder suspended in 25 cc of normal saline and injected into the joint after closure of the arthrotomy. Serum from peripheral venous blood and drain fluid samples were collected at one, four, and 24 hours postoperatively. All concentrations are reported in µg per ml.ResultsA total of 22 patients were included in final analysis. At one, four, and 24 hours postoperatively, mean (95% confidence interval (CI)) serum concentrations were 2.4 (0.7 to 4.1), 5.0 (3.1 to 6.9), and 4.8 (2.8 to 6.9) for vancomycin and 4.9 (3.4 to 6.3), 7.0 (5.8 to 8.2), and 1.3 (0.8 to 1.8) for tobramycin; intra-articular concentrations were 1,900.6 (1,492.5 to 2,308.8), 717.9 (485.5 to 950.3), and 162.2 (20.5 to 304.0) for vancomycin and 2,105.3 (1,389.9 to 2,820.6), 403.2 (266.6 to 539.7), and 98.8 (0 to 206.5) for tobramycin.ConclusionIntra-articular administration of 1 g of vancomycin and 600 mg of tobramycin as a solution after closure of the arthrotomy in primary cementless TKA achieves therapeutic intra-articular concentrations over the first 24 hours postoperatively and does not reach sustained toxic levels in peripheral blood.Cite this article: Bone Joint J2021;103-B(11):1702–1708.

AimsThe goal of the current systematic review was to assess the impact of implant placement accuracy on outcomes following total knee arthroplasty (TKA).MethodsA systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the Ovid Medline, Embase, Cochrane Central, and Web of Science databases in order to assess the impact of the patient-reported outcomes measures (PROMs) and implant placement accuracy on outcomes following TKA. Studies assessing the impact of implant alignment, rotation, size, overhang, or condylar offset were included. Study quality was assessed, evidence was graded (one-star: no evidence, two-star: limited evidence, three-star: moderate evidence, four-star: strong evidence), and recommendations were made based on the available evidence.ResultsA total of 49 studies were identified for inclusion. With respect to PROMs, there was two-star evidence in support of mechanical axis alignment (MAA), femorotibial angle (FTA), femoral coronal angle (FCA), tibial coronal angle (TCA), femoral sagittal angle (FSA), femoral rotation, tibial and combined rotation/mismatch, and implant size/overhang or offset on PROMs, and one-star evidence in support of tibial sagittal angle (TSA), impacting PROMs. With respect to survival, there was three- to four-star evidence in support FTA, FCA, TCA, and TSA, moderate evidence in support of femoral rotation, tibial and combined rotation/mismatch, and limited evidence in support of MAA, FSA, and implant size/overhang or offset impacting survival.ConclusionOverall, there is limited evidence to suggest that PROMs are impacted by the accuracy of implant placement, and malalignment does not appear to be a significant driver of the observed high rates of patient dissatisfaction following TKA. However, FTA, FCA, TCA, TSA, and implant rotation demonstrate a moderate-strong relationship with implant survival. Efforts should be made to improve the accuracy of these parameters in order to improve TKA survival.Cite this article: Bone Joint J2021;103-B(9):1449–1456.

MnBi2Te4represents a new class of magnetic topological insulators in which novel quantum phases emerge at temperatures higher than those found in magnetically doped thin films. Here, we investigate how couplings between electron, spin, and lattice are manifested in the phonon spectra of few-septuple-layer thick MnBi2Te4. After categorizing phonon modes by their symmetries, we study the systematic changes in frequency, line width, and line shape of a spectrally isolated A1gmode. The electron–phonon coupling increases in thinner flakes as manifested in a broader phonon line width, which is likely due to changes of the electron density of states. In 4- and 5-septuple thick samples, the onset of magnetic order below the Néel temperature is concurrent with a transition to an insulating state. We observe signatures of a reduced electron–phonon scattering across this transition as reflected in the reduced Fano parameter. Finally, spin–lattice coupling is measured and modeled from temperature-dependent phonon frequency.

AimsDual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA.MethodsThis was a prospective study involving patients aged < 65 years, with a BMI of < 35 kg/m2, and University of California, Los Angeles activity score of > 6 who underwent primary THA with a modular cobalt chrome acetabular liner, highly cross-linked polyethylene mobile bearing, and a cementless titanium femoral stem. Patient-reported outcome measures, whole blood metal ion levels (μg/l), and periprosthetic femoral BMD were measured at baseline and at one, two, and five years postoperatively. The results two years postoperatively for this cohort have been previously reported.ResultsA total of 43 patients were enrolled. At minimum follow-up of five years, 23 (53.4%) returned for clinical and radiological review, 25 (58.1%) had metal ion analysis performed, 19 (44.2%) underwent dual energy x-ray absorptiometry scans, and 25 (58%) completed a pain-drawing questionnaire. The mean modified Harris Hip Scores improved significantly from 54.8 (SD 19) preoperatively to 93.08 (SD 10.5) five years postoperatively (p < 0.001). One patient was revised for aseptic acetabular loosening. The mean cobalt levels increased from 0.065 μg/l (SD 0.03) to 0.08 (SD 0.05) and the mean titanium levels increased from 0.35 (SD 0.13) to 0.78 (SD 0.29). The femoral BMD ratio decreased in Gruen Zone 1 (91.9%) at five years postoperatively compared with the baseline scores at six weeks potoperatively. The femoral BMD ratio was maintained in Gruen zones 2 to 7.ConclusionThe use of a modular DM component and a cementless, tapered femoral stem shows excellent mid-term survivorship with minimal concerns for corrosion and metal ion release in a cohort of young, active patients undergoing primary THA.Cite this article: Bone Joint J2021;103-B(7 Supple B):73–77.

AimsThe purpose of this study was to determine the access to and ability to use telemedicine technology in adult patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), and to determine associations with the socioeconomic characteristics of the patients, including age, sex, race, and education. We also sought to understand the patients’ perceived benefits, risks, and preferences when dealing with telemedicine.MethodsWe performed a cross-sectional survey involving patients awaiting primary THA and TKA by one of six surgeons at a single academic institution. Patients were included and called for a telephone-administered survey if their surgery was scheduled to be between 23 March and 2 June 2020, and were aged > 18 years.ResultsThe response rate was 52% (189 of 363 patients). A total of 170 patients (90.4%) reported using the internet, 177 (94.1%) reported owning a device capable of videoconferencing, and 143 (76.1%) had participated in a video call in the past year. When asked for their preferred method for a consultation, 155 (82.8%) and 26 (13.9%) ranked in-person and a videoconference as their first choice, respectively. The perceived benefits of telemedicine consultations included reduced travel to appointments (165 (88.2%) agreed) and reduced cost of attending appointments (123 (65.8%) agreed). However, patients were concerned that they would not establish the same patient-physician connection (100 (53.8%) agreed), and would not receive the same level of care (52 (33.2%) agreed) using telemedicine consultations compared with in-person consultations.ConclusionMost patients undergoing arthroplasty have access to and are capable of using the technology required for telemedicine consultations. However, they still prefer in-person consultations due to concerns that they will not establish the same patient-physician connection and will not receive the same level of care, despite the benefits of reducing the time spent in travelling and the cost of attending appointments, and the appointments being easier to attend.Cite this article: Bone Joint J2021;103-B(7 Supple B):98–102.

Background: The purpose of this study was to evaluate gender differences in patient outcomes and complications following total ankle replacement (TAR).Methods: Consecutive patients who underwent primary TAR from July 2007 through May 2016 were prospectively followed and retrospectively reviewed. Demographic, operative, patient-reported outcomes (PROs), and complication data were collected and analyzed. PROs included the visual analog scale (VAS), 36-Item Short-Form Health Survey (SF-36), American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scale, and Short Musculoskeletal Function Assessment (SMFA). A total of 475 patients were evaluated, including 248 males (52.2%) and 227 females (47.8%) with an average of 56.8 months follow-up.Results: Women were more likely to have inflammatory arthritis (13.7% vs 2.8%; P< .01) and significantly worse preoperative SF-36 total, SF-36 mental health component, AOFAS total, AOFAS pain, SMFA function, and SMFA bother scores (all P< .05). Both genders demonstrated significant improvement in PROs at 1, 2, and 5 years. The magnitude of improvement was similar between genders for all PROs (all P< .05) with the exception of SF-36 physical function, which was greater in men. Females underwent more nonrevision reoperations (32.2% vs 22.6%; P= .0191), but there was no significant difference in failure rates (male 7.3% vs female 3.5%; P= .07). The reoperation and failure rates at 2 years postoperation were 10.1% and 1.6% for men and 18.5% and 0.9% for women, respectively.Conclusion: Women undergoing TAR were more likely to have worse preoperative PROs and higher rates of nonrevision reoperations, which remains true when controlling for their increased incidence of inflammatory arthritis. However, women reported similar improvements in PROs and had similar prosthetic survival rates as men. Increased understanding of these disparities, combined with gender-based interventions, may further advance patient outcomes.Level of Evidence: Level III, therapeutic, retrospective comparative series

Background: The purpose of this study was to report on the radiographic outcomes, clinical outcomes, and implant survivorship following extramedullary-referenced (EMr) vs intramedullary-referenced (IMr) total ankle replacement (TAR).Methods: From May 2007 to February 2018, a consecutive series of patients with end-stage tibiotalar osteoarthritis undergoing TAR was enrolled in this study. Analyses were performed comparing IMr vs EMr components for patient-reported outcomes data, pre- and postoperative radiographic ankle alignment, concomitant procedures, and complications. Kaplan-Meier survivorship analyses served to determine implant reoperation and revision surgery. A total of 340 TARs were included with 105 IMr TAR and 235 EMr TAR. The mean follow-up was 5.3 years (±2.5, range 2-12).Results: The absolute value for preoperative coronal alignment was significantly greater for IMr compared to EMr TAR (13.0 vs 6.4 degrees; P< .0001), but both groups achieved near neutral alignment postoperatively (1.4 vs 1.5 degrees; P= .6655). The odds of having a concomitant procedure was 2.7 times higher in patients with an IMr TAR (OR 2.7, CI 1.7-4.4; P< .0001). There were similar improvements in patient-reported outcome scores at 1 year and final follow-up (all P> .05). The 5-year implant survivorship was 98.6% for IMr vs 97.5% for EMr at final follow-up.Conclusion: The IMr and EMr TAR components had comparable postoperative alignment, patient-reported outcome scores, and complications. The 5-year implant survivorship was similar between the IMr and EMr groups.Level of Evidence: Level III, retrospective comparative study.

Graphical Abstract

Background: We aimed to perform an economic analysis and compare the clinical outcomes between inpatient and short-stay designation total ankle replacement (TAR).Methods: We performed a retrospective study on 178 consecutive patients undergoing primary inpatient versus short-stay designation TAR during the 2016 and 2017 fiscal years. Patient demographics, concomitant procedures, perioperative complications, patient-reported outcomes, and perioperative costs were collected.Results: The mean age of our cohort was 62.5 ± 9.6 years (range, 30-88 years), with a significant difference in age (64.1 vs 58.5 years) (P= .005) and Charlson Comorbidity Index (3.3 ± 1.9 vs 2.3 ± 1.4; P= .002) for the inpatient and short-stay designation groups, respectively. At a mean follow-up of 29.6 ± 11.8 months (range, 12-52.3 months), there was no difference in complications between groups (P= .97). The inpatient designation TAR group had a worse baseline Short Musculoskeletal Functional Assessment (SMFA) function score (76.1; 95% CI, 70.5-81.6) than the short-stay designation TAR group (63.9; 95% CI, 52.5-75.3) while achieving similar final postoperative SMFA function scores for the inpatient (55.2; 95% CI, 51.1-59.2) and short-stay (56.2; 95% CI, 48.2-64.2) designation TAR groups (P> .05). However, the inpatient designation TAR group showed a significantly greater mean improvement in SMFA function score (20.9; 95% CI, 19.4-22.4) compared with the short-stay designation TAR group (7.7; 95% CI, 3.7-11.1) (P= .0442). The total direct cost was significantly higher for the inpatient designation group ($15 340) than the short-stay designation group ($13 002) (P< .001).Conclusion: While inpatient designation TARs were more comorbid, short-stay designation TARs were associated with a 15.5% reduction in perioperative costs, comparable complication rates, and similar final postoperative patient-reported outcome scores compared with inpatient TARs.Level of Evidence: Level III, retrospective comparative study.

COVID‐19, the clinical syndrome caused by the novel coronavirus, SARS‐CoV‐2, continues to rapidly spread, leading to significant stressors on global healthcare infrastructure. The manifestations of COVID‐19 in solid organ transplant recipients are only beginning to be understood with cases reported to date in transplant recipients on chronic immunosuppression. Herein, we report the first case of COVID‐19 in a lung transplant recipient in the immediate posttransplant period, and we describe the epidemiologic challenges in identifying the source of infection in this unique situation. COVID‐19 early after lung transplantation presents unique epidemiological and clinical management challenges.

Background: The current operative standard of treatment for bimalleolar equivalent ankle fracture is open reduction and internal fixation (ORIF) of the lateral malleolus followed by syndesmotic stabilization if indicated. There is controversy surrounding the indication and need for deltoid ligament repair in this setting. The purpose of this study was to quantify the biomechanical effect of deltoid ligament repair in an ankle fracture soft tissue injury model.Methods: Nine fresh-frozen cadaveric specimens were included in this study. Each leg was tested under 5 conditions: intact, syndesmosis and deltoid ligament sectioned, syndesmosis fixed, deltoid repaired, and both the syndesmosis and deltoid ligament repaired. Anterior, posterior, lateral, and medial drawer and rotational stresses were applied to the foot, and the resulting talus displacement was documented.Results: Isolated deltoid repair significantly reduced anterior displacement to normal levels. Displacement with lateral drawer testing was not significantly corrected until both structures were repaired. Deltoid repair and syndesmosis fixation each reduced internal rotation significantly with further reduction to normal levels when both were repaired. External rotation remained elevated relative to the intact condition regardless of which structures were repaired.Conclusion: There is existing controversy regarding the importance of deltoid ligament repair in the setting of ankle fractures. The findings of this biomechanical study indicate that deltoid ligament repair enhances ankle stability in ankle fractures with both syndesmotic and deltoid disruption.Clinical Relevance: Concomitant deltoid ligament repair in addition to stabilization of fracture and syndesmosis may improve long-term functioning of the ankle joint and clinical outcomes.

Background: Characteristics of responders, or those who achieve a clinical improvement above the level of a minimal clinically important difference, have not been defined for total ankle arthroplasty (TAA). The purpose of this study was to determine patient characteristics that distinguish possible responders from possible nonresponders after TAA using criteria established for other arthroplasty surgeries.Methods: Patients undergoing TAA who were enrolled into a prospective study at a single academic center evaluating patient-reported outcomes were included. Patients were characterized as possible responders if the relative or absolute improvement in their 2-year follow-up Short Musculoskeletal Function Assessment (SMFA) function score was at least 50% or 20, respectively, compared with their preoperative score, consistent with Outcome Measures in Rheumatoid Arthritis Clinical Trials and the Osteoarthritis Research Society International (OMERACT-OARSI) responder criteria. Patient factors were then associated with possible responder or nonresponder status and a multivariable analysis was performed. A total of 491 patients with complete data and 2-year follow-up were included in this study.Results: Multivariable analysis demonstrated that a higher baseline 36-Item Short-Form Survey (SF-36) mental component summary (MCS) score (OR [95% CI], 1.02 [1.01, 1.04]; P= .003), indicating better mental health, was associated with being a possible responder to TAA. The presence of rheumatic disease (OR [95% CI], 0.38 [0.22, 0.67]; P= .001) was a significant predictor of being a possible nonresponder.Conclusion: Our data reveal that a higher baseline SF-36 MCS score was associated with increased improvement in SMFA function scores, while rheumatic disease was associated with worse improvement in SMFA function scores after TAA. Patients with rheumatic disease or poor mental health may not achieve as favorable results after TAA and should be counseled appropriately.Level of Evidence: Level III, retrospective comparative study.

AimsRoutine surveillance of primary hip and knee arthroplasties has traditionally been performed with office follow-up visits at one year postoperatively. The value of these visits is unclear. The present study aims to determine the utility and burden of routine clinical follow-up at one year after primary arthroplasty to patients and providers.MethodsAll patients (473) who underwent primary total hip (280), hip resurfacing (eight), total knee (179), and unicompartmental knee arthroplasty (six) over a nine-month period at a single institution were identified from an institutional registry. Patients were prompted to attend their routine one-year postoperative visit by a single telephone reminder. Patients and surgeons were given questionnaires at the one-year postoperative visit, defined as a clinical encounter occurring at nine to 15 months from the date of surgery, regarding value of the visit.ResultsCompliance with routine follow-up at one year was 35%. The response rate was over 80% for all questions in the patient and clinician surveys. Overall, 75% of the visits were for routine surveillance. Patients reported high satisfaction with their visits despite the general time for attendance, including travel, being over four hours. Surgeons found the visits more worthwhile when issues were identified or problems were addressed.ConclusionPatient compliance with follow-up at one year postoperatively after primary hip and knee is low. Routine visits of asymptomatic patients deliver little practical value and represent a large time and cost burden for patients and surgeons. Remote strategies should be considered for routine postoperative surveillance primary hip and knee arthroplasties beyond the acute postoperative period.Cite this article: Bone Joint J2020;102-B(7 Supple B):85–89.

AimsThe aim of this study was to determine if the local delivery of vancomycin and tobramycin in primary total knee arthroplasty (TKA) can achieve intra-articular concentrations exceeding the minimum inhibitory concentration thresholds for bacteria causing acute prosthetic joint infection (PJI).MethodsUsing a retrospective single-institution database of all primary TKAs performed between January 1 2014 and May 7 2019, we identified patients with acute PJI that were managed surgically within 90 days of the initial procedure. The organisms from positive cultures obtained at the time of revision were tested for susceptibility to gentamicin, tobramycin, and vancomycin. A prospective study was then performed to determine the intra-articular antibiotic concentration on postoperative day one after primary TKA using one of five local antibiotic delivery strategies with tobramycin and/or vancomycin mixed into the polymethylmethacrylate (PMMA) or vancomycin powder.ResultsA total of 19 patients with acute PJI after TKA were identified and 29 unique bacterial isolates were recovered. The mean time to revision was 37 days (6 to 84). Nine isolates (31%) were resistant to gentamicin, ten (34%) were resistant to tobramycin, and seven (24%) were resistant to vancomycin. Excluding one Fusobacterium nucleatum, which was resistant to all three antibiotics, all isolates resistant to tobramycin or gentamicin were susceptible to vancomycin and vice versa. Overall, 2.4 g of tobramycin hand-mixed into 80 g of PMMA and 1 g of intra-articular vancomycin powder consistently achieved concentrations above the minimum inhibitory concentrations of susceptible organisms.ConclusionOne-third of bacteria causing acute PJI after primary TKA were resistant to the aminoglycosides commonly mixed into PMMA, and one-quarter were resistant to vancomycin. With one exception, all bacteria resistant to tobramycin were susceptible to vancomycin and vice versa. Based on these results, the optimal cover for organisms causing most cases of acute PJI after TKA can be achieved with a combination of tobramycin mixed in antibiotic cement, and vancomycin powder.Cite this article: Bone Joint J2020;102-B(6 Supple A):163–169.

The VANTAGE total ankle arthroplasty is a novel anatomic mobile or fixed-bearing total ankle arthroplasty with a good and simple instrumentation giving to surgeons a safe implantation ventral approach technique. Our first cases report a successful functional outcome for patients, with or without additional surgeries, and without very early complications.

Background: Neutral ankle alignment along with medial and lateral support are paramount to the success of total ankle replacement (TAR). Fibula, intra-articular medial malleolus, and supramalleolar tibia osteotomies have been described to achieve these goals; however, the literature is scant with outcomes and union rates of these osteotomies performed concomitant to TAR. The purpose of this study was to describe our results.Methods: A retrospective review was performed to identify patients who had a concomitant tibia, fibula, or combined tibia and fibula osteotomy at the same time as TAR. Routine radiographs were used to assess osteotomy union rates and changes in alignment. Outcomes questionnaires were evaluated preoperatively and at most recent follow-up. Twenty-six patients comprising 4% of the total TAR cohort were identified with a mean follow-up of 3.9 years.Results: There were 12 combined tibia and fibula osteotomies, 9 isolated tibia osteotomies, and 5 isolated fibula osteotomies. The union rate for these osteotomies was 92%, 100%, and 100%, respectively. Mean coronal alignment improved from 15.2 to 2.1 degrees (P< .001). There was significant improvement in patient-reported outcome scores, including Short Form-36, Short Musculoskeletal Function Assessment, and visual analog scale pain. There was 1 failure in the study.Conclusion: These data demonstrate successful use of tibia, fibula, or combined tibia and fibula osteotomies at the same time as TAR in order to gain neutral ankle alignment. The overall union rate was 96% with significant improvement in alignment, pain, and patient-reported outcomes. We believe concomitant osteotomies can be considered a successful adjunctive procedure to TAR.Level of Evidence: Level III, retrospective comparative series.

Background: The utilization of total ankle arthroplasty (TAA) for managing severe ankle osteoarthritis has become increasingly common, leading to a higher occurrence of revision TAA procedures because of failure of primary TAA. This study aims to examine the clinical results associated with revision TAA using the INBONE II system. Given the growing number of TAA revision procedures and a focus on motion-preserving salvage options, we evaluated our early experience with revision TAA.Methods: A retrospective analysis was conducted on a group of 60 presumed noninfected patients who underwent revision TAA with the INBONE II system. Detailed information was collected on patient demographics, implant characteristics, concurrent procedures, and complications. The implant survival was estimated using Kaplan-Meier analysis.Results: The study revealed high complication rates but generally fair clinical outcomes for revision TAA using the INBONE II system. Complications were observed in 22 patients (36.7%), including persistent pain (n = 6), nerve injury/impingement (n = 5), infection (n = 3), fracture (n = 3), implant failure (n = 3), impaired wound healing (n = 2), and osteolysis (n = 3). The 3-year survivorship rate from reoperation was 92.0% (82.7%-100.0%) whereas the 3-year survivorship rate from major complications was 90.4% (80.8%-100.0%).Conclusion: We report high complication rates but generally fair clinical results for revision TAA utilizing the INBONE II system.Level of Evidence: Level IV, retrospective case series study.

Background: Ankle arthritis differs from arthritis of the hip and knee in that 80% is posttraumatic and thus often occurs in a younger patient population. The literature supporting total ankle arthroplasty (TAA) in younger patients has increased over recent years and has bolstered the argument that in the short term, TAA in younger patients has successful outcomes that are comparable to older, lower-demand patients. The purpose of our study was to evaluate patient-reported outcomes (PROs) and implant survivorship at midterm after primary TAA in patients ≤ 50 years of age at the time of surgery.Methods: A retrospective chart review was conducted of patients ≤ 50 years of age who underwent primary TAA at a single institution from 2000 to 2017. Patient demographics, outcome measures, and complications were recorded. All patients had a minimum clinical follow-up of 5 years. PRO measures were evaluated at preoperative, 1-year postoperative, and final follow-up visits. Paired ttests were performed to compare individual patient changes in PROs from preoperative. Implant survivorship was evaluated based on need for revision of either the tibial or talar component. The need for additional surgery related to the TAA was also evaluated.Results A total of 58 patients were included. The average age at the time of the index surgery was 43.3 years (range 22-50 years). All patients had a minimum follow-up of 5 years with a mean follow-up of 8.8 years. A total of 11 patients required additional surgery related to their TAA. Six patients (10.3%) required bone grafting of peri-implant cysts, 3 patients (5.2 %) required gutter debridement, and 1 patient underwent complete revision of metal components. Mean visual analog scale, 36-item Short Form Health Survey, Short Musculoskeletal Function Assessment, and American Orthopaedic Foot & Ankle Society hindfoot scores significantly improved from preoperative to 1-year postoperative and final postoperative follow-up.Conclusion: The patients aged ≤50 years treated with a TAA whom we have been able to observe for a minimum of 5 years showed generally maintained improvement in functional scores and thus far have had a relatively low rate of secondary surgeries.

Background: Outcomes of total ankle replacement for the treatment of end-stage ankle arthritis continue to improve. Debate continues whether a mobile-bearing total ankle replacement (MB-TAR) or a fixed-bearing total ankle replacement (FB-TAR) is superior, with successful outcomes reported long term for MB-TAR and at intermediate- to long-term follow-up for newer generation FB-TAR. Although comparisons between the 2 total ankle designs have been reported, to our knowledge, no investigation has compared the 2 designs with a high level of evidence. This prospective, randomized controlled trial conducted at a single institution compares patient satisfaction, functional outcomes, and radiographic results of the mobile-bearing STAR and the fixed-bearing Salto-Talaris in the treatment of end-stage ankle arthritis.Methods: Between November 2011 and November 2014, adult patients with end-stage ankle osteoarthritis failing nonoperative treatment were introduced to the study. With informed consent, 100 patients (31 male and 69 female, average age 65 years, range 35-85 years) were enrolled; a demographic comparison between the 2 cohorts was similar. Exclusion criteria included inflammatory arthropathy, neuropathy, weight exceeding 250 pounds, radiographic coronal plane deformity greater than 15 degrees, or extensive talar dome wear pattern (“flat-top talus”). Prospective patient-reported outcomes, physical examination, and standardized weightbearing ankle radiographs were obtained preoperatively, at 6 and 12 months postoperatively, and then at yearly intervals. Data collection included visual analog pain score, Short Form 36, Foot and Ankle Disability Index, Short Musculoskeletal Functional Assessment, and American Orthopaedic Foot & Ankle Society ankle-hindfoot score. Surgeries were performed by a nondesign team of orthopedic foot and ankle specialists with total ankle replacement expertise. Statistical analysis was performed by a qualified statistician. At average follow-up of 4.5 years (range, 2-6 years) complete clinical data and radiographs were available for 84 patients; 7 had incomplete data, 1 had died, 4 were withdrawn after enrolling but prior to surgery, and 4 were lost to follow-up.Results: In all outcome measures, the entire cohort demonstrated statistically significant improvements from preoperative evaluation to most recent follow-up with no statistically significant difference between the 2 groups. Radiographically, tibial lucency/cyst formation was 26.8% and 20.9% for MB-TAR and FB-TAR, respectively. Tibial settling/subsidence occurred in 7.3% of MB-TAR. Talar lucency/cyst formation occurred in 24.3% and 2.0% of MB-TAR and FB-TAR, respectively. Talar subsidence was observed in 21.9% and 2.0% of MB-TAR and FH-TAR, respectively. Reoperations were performed in 8 MB-TARs and 3 FH-TARs, with the majority of procedures being to relieve impingement or treat cysts and not to revise or remove metal implants.Conclusion: With a high level of evidence, our study found that patient-reported and clinical outcomes were favorable for both designs and that there was no significant difference in clinical improvement between the 2 implants. The incidence of lucency/cyst formation was similar for MB-TAR and FH-TAR for the tibial component, but the MB-TAR had greater talar lucency/cyst formation and tibial and talar subsidence. As has been suggested in previous studies, clinical outcomes do not necessarily correlate with radiographic findings. Reoperations were more common for MB-TAR and, in most cases, were to relieve impingement or treat cysts rather than revise or remove metal implants.Level of Evidence: Level I, prospective randomized study.

Background: Evidence on the management of and outcomes from periprosthetic fractures about a total ankle replacement (TAR) are limited. The purpose of this study was to develop an algorithm for the management of patients with postoperative periprosthetic fractures about a TAR.Methods: This was a retrospective analysis of patients undergoing a TAR from 2007 through 2017 with a subsequent periprosthetic fracture >4 weeks from index surgery. Implant stability was defined radiographically and intraoperatively where appropriate. Univariate and multivariate analyses were used to identify differences in outcomes. Thirty-two patients were identified with a remote TAR periprosthetic fracture with an average follow-up of 26 months (range, 3-104 months).Results: Most fractures were located about the medial malleolus (62.5%); the majority of fractures (75%) were deemed to have stable implants. Fractures of the talus always had unstable implants and always required revision TAR surgery (100%, P= .0002). There was no difference in patient-reported outcomes between stable and unstable fractures at an average of 36 months. In a multivariate analysis, fracture location (talus), less time to fracture, and implant type were found to be predictive of unstable implants (P< .001). Implant stability was independently associated with the need for revision surgery (P< .049). Nonoperative treatment was independently associated with treatment failure (P< .001).Conclusion: The majority of stable fractures about a TAR required operative fixation. Management with immobilization was fraught with a high rate of subsequent surgical intervention. We found that fractures about the talus required revision TAR surgery or arthrodesis.Level of Evidence: Level III, retrospective cohort study.

AimsWhether patient-reported pain differs among surgical approaches in total hip arthroplasty (THA) remains unclear. This study’s purposes were to determine differences in pain based on surgical approach (direct anterior (DA) vsposterolateral (PL)) and PL approach incision length. Patients and MethodsThis was a retrospective investigation from two centres and seven surgeons (three DA, three PL, one both) of primary THAs. PL patients were categorized for incision length (6 cm to 8 cm, 8 cm to 12 cm, 12 cm to 15 cm). All patients had cementless femoral and acetabular fixation, at least one year’s follow-up, and well-fixed components. Patients completed a pain-drawing questionnaire identifying the location and intensity of pain on an anatomical diagram. Power analysis indicated 800 patients in each cohort for adequate power to detect a 4% difference in pain (alpha = 0.05, beta = 0.80).ResultsA total of 1848 patients (982 DA, 866 PL) were included. PL patients were younger (59.4 years, sd12.9 vs62.7 years, sd9.7; p < 0.001) and had shorter follow-up (3.3 years, sd1.3 vs3.7 years, sd1.3; p < 0.001). DA patients reported decreased moderate to severe trochanteric (14% vs21%; p < 0.001) and groin pain (19% vs24%; p = 0.004) than PL patients. There were no differences in anterior, lateral, or posterior thigh, back, or buttock pain between cohorts (p = 0.05 to 0.7). PL approach incision length did not impact the incidence or severity of pain (p = 0.3 to 0.7).ConclusionA significant proportion of patients perceive persistent pain following THA regardless of approach. DA patients reported less trochanteric and groin pain versusPL patients. PL incision length did not influence the incidence or severity of patient-reported pain.Cite this article: Bone Joint J2019;101-B(6 Supple B):31–36.

AimsModular dual mobility (DM) prostheses in which a cobalt-chromium liner is inserted into a titanium acetabular shell (vsa monoblock acetabular component) have the advantage of allowing supplementary screw fixation, but the potential for corrosion between the liner and acetabulum has raised concerns. While DM prostheses have shown improved stability in patients deemed ‘high-risk’ for dislocation undergoing total hip arthroplasty (THA), their performance in young, active patients has not been reported. This study’s purpose was to assess clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) in young, active patients receiving a modular DM acetabulum and recently introduced titanium, proximally coated, tapered femoral stem design.Patients and MethodsThis was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m2and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. Patients with a history of renal disease and metal hardware elsewhere in the body were excluded. A total of 43 patients (30 male, 13 female; mean age 52.6 years (sd6.5)) were enrolled. All patients had a minimum of two years’ clinical follow-up. Patient-reported outcome measures, whole blood metal ion levels (ug/l), and periprosthetic femoral BMD were measured at baseline, as well as at one and two years postoperatively. Power analysis indicated 40 patients necessary to demonstrate a five-fold increase in cobalt levels from baseline (alpha = 0.05, beta = 0.80). A mixed model with repeated measures was used for statistical analysis.ResultsMean Harris Hip Scores improved from 54.1 (sd20.5) to 91.2 (sd10.8) at two years postoperatively (p < 0.001). All patients had radiologically well-fixed components, no patients experienced any instability, and no patients required any further intervention. Mean cobalt levels increased from 0.065 ug/l (sd0.03) preoperatively to 0.30 ug/l (sd0.51) at one year postoperatively (p = 0.01) but decreased at two years postoperatively to 0.16 ug/l (sd0.23; p = 0.2). Four patients (9.3%) had a cobalt level outside the reference range (0.03 ug/l to 0.29 ug/l) at two years postoperatively, with values from 0.32 ug/l to 0.94 ug/l. The mean femoral BMD ratio was maintained in Gruen zones 2 to 7 at both one and two years postoperatively using this stem design. At two years postoperatively, mean BMD in the medial calcar was 101.5% of the baseline value.ConclusionUse of a modular DM prosthesis and cementless, tapered femoral stem has shown encouraging results in young, active patients undergoing primary THA. Elevation in mean cobalt levels and the presence of four patients outside the reference range at two years postoperatively demonstrates the necessity of continued surveillance in this cohort.Cite this article: Bone Joint J2019;101-B:365–371.

Background: Total ankle arthroplasty (TAA) is increasingly being recognized as an effective surgical option for end-stage ankle arthritis. Associated hindfoot arthrodesis procedures are at times needed to correct malalignment or to address adjacent joint arthritis. Results following TAA and associated hindfoot arthrodesis have at times been underwhelming and the devascularization of the talar blood supply has been postulated as a potential cause. This study explored the association between hindfoot arthrodesis fixation and talar component subsidence.Methods: The study included 81 consecutive patients who underwent a TAA with either an isolated subtalar arthrodesis or combined subtalar and talonavicular arthrodesis with a minimum of 2 years of follow-up. Radiographic and clinical evaluations including patient-reported outcomes were performed at each postoperative visit. The primary outcome measure was the presence of talar component subsidence while patient-reported outcomes were the secondary outcome measure.Results: 30.9% of patients had evidence of talar component subsidence. Subsidence was seen in 55.5% of patients with dorsal to plantar subtalar fixation compared to 11.1% of patients with plantar to dorsal screws (P< .001) and in 44.4% of patients with screws violating the sinus tarsi compared to 3.7% of patients without screws in the sinus tarsi (P< .001). Screws that were placed from dorsal to plantar were more likely to violate the sinus tarsi (P< .001). Patients with evidence of talar subsidence reported higher pain scores and lower functional scores. There were 8 TAA failures, and the presence of dorsal to plantar screws was associated with failure (P< .01).Conclusion: Screws that are placed across the subtalar joint from a dorsal to plantar approach are more likely to violate the sinus tarsi, contributing to a significantly higher rate of talar component subsidence when associated with TAA.Level of Evidence: Level II, prospective comparative series.

Vascularized bone grafting for talar avascular osteonecrosis is indicated for patients with modified Ficat and Arlet stage I to III disease with minimal subchondral collapse. Outcomes may be more durable than core decompression alone, especially in patients with more advanced disease. Our preferred method, described in this article, involves core decompression followed by use of a vascularized cuboid pedicle graft placed in the defect. Outcomes reported in a small case series have been encouraging, with more than 80% of patients requiring no further surgery.

Background: As the popularity of total ankle arthroplasty (TAA) increases and indications expand, surgeons require a better understanding of which patient factors are associated with implant failure. In this study, we aimed to use a large total ankle database to identify independent risk factors for implant failure at mid- to long-term follow-up.Methods: A prospectively collected database was used to identify all patients who underwent primary TAA with a minimum 5 years’ follow-up. The primary outcome was revision, defined as removal of one or both metal components; failures due to infection were excluded. Patient and clinical factors analyzed included age, sex, body mass index (BMI), smoking status, presence of diabetes, indication for TAA, implant, tourniquet time, and presence of ipsilateral hindfoot fusion. Preoperative coronal deformity and sagittal talar translation were assessed, as were postoperative coronal and sagittal tibial component alignment. Univariable and multivariable analyses were performed to identify predictors of implant failure. After excluding 5 ankles that failed because of deep infection, 533 ankles with a mean 7 (range, 5-11) years of follow-up met the inclusion criteria. Four implants were used: INBONE I, INBONE II, STAR, and Salto-Talaris.Results: Thirty-four ankles (6.4%) were revised or removed a mean 4 (range, 1-9) years postoperatively. The only independent predictors of failure were the INBONE I prosthesis and ipsilateral hindfoot fusion (P= .006 and P= .023, respectively).Conclusions: This is among the largest studies to analyze the relationship between TAA failure rates and multiple different patient, operative, and radiographic factors. Of note, age, BMI, and amount of deformity were not associated with higher failure rates. Only patients with ipsilateral hindfoot fusion or who received the INBONE I prosthesis were at significantly higher risk of implant failure.Level of Evidence: Level III, retrospective cohort study.