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Background Locked posterior glenohumeral dislocations with a reverse Hill-Sachs impaction fracture involving less than 30% of the humeral head are most frequently treated with lesser tuberosity transfer into the defect, whereas those involving more than 50% undergo humeral head arthroplasty. Reconstruction of the defect with segmental femoral osteochondral allografts has been proposed to treat patients between these two ranges, but the medium−/long-term outcomes of this joint-preserving procedure are controversial. Methods Between 2001 and 2018, 12 consecutive patients with a unilateral locked posterior shoulder dislocation and an impaction fracture from 30 to 50% (mean 31% ± 1.32) of the humeral head were treated with segmental reconstruction of the defect with fresh-frozen humeral head osteochondral allografts. Patients were assessed clinically, radiographically and with computed tomography (CT) at a medium follow-up of 66 ± 50.25 months (range, 24–225). Results All twelve shoulders presented a slight limitation in anterior elevation (average, 166.6° ± 22.76). The mean active external rotation with the shoulder at 90° of abduction was 82.5° ± 6.61, and that with the arm held in stable adduction was 79.16 ± 18.80. The mean abduction was 156.25° ± 25.09. The mean Constant-Murley score (CS) was 82 ± 15.09 points (range, 40–97 points), and the mean ASES was 94 ± 8.49 points. The mean pre- and postoperatively Western Ontario Shoulder Instability index (WOSI) was 236.5 ± 227.9 and 11.20 ± 10.85, respectively. Development of osteoarthrosis (OA) was minimal. The average allograft resorption rate was 4% ± 2.4. There were no cases of failure (reoperation for any reason) in this series. Conclusion Segmental humeral head reconstruction with humeral head fresh-frozen osteochondral allografts provides good to excellent clinical results with low-grade OA and low allograft resorption in patients with locked posterior shoulder dislocation. Trial registration ClinicalTrials.gov PRS, ClinicalTrials.gov ID: NCT04823455. Registered 29 March 2021 - Retrospectively registered, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000AU8P&selectaction=Edit&uid=U0004J36&ts=12&cx=6cykp8 Level of evidence Level IV, Case Series, Treatment Study.

The case of a former high-level professional soccer player is presented at 10-year follow-up after arthroscopically implanted lateral Collagen Meniscus Implant (CMI). The patient achieved a full-knee functional recovery and a complete sport resumption to the same pre-injury level for several soccer seasons and he is still performing semi-professional soccer activity (minor league) 10years after surgery. Level of evidence Case Report. Level IV.

Lateral closing wedge osteotomies are still actual treatments of unicompartmental arthrosis and deformities. This article focuses on surgical timing, indications, and technique to achieve a pain-free knee joint and a normal weight forces distribution.

Purpose: To evaluate if there was a correlation between in vivo kinematics of a medial-stabilized (MS) total knee arthroplasty (TKA) and post-operative clinical scores. We hypothesized that (1) a MS-TKA would produce a medial pivot movement and that (2) this specific pattern would be correlated with higher clinical scores. Methods: 18 patients were evaluated through clinical and functional scores evaluation (Knee Society Score clinical and functional, Womac, Oxford), and kinematically through dynamic radiostereometric analysis (RSA) at 9months after MS-TKA, during the execution of a sit-to-stand and a lunge motor task. The anteroposterior (AP) Low Point translation of medial and lateral femoral compartments was compared through Student’s t test (p < 0.05). A correlation analysis between scores and kinematics was performed through the Pearson’s correlation coefficient r. Results: A significantly greater (p < 0.0001) anterior translation of the lateral compartment with respect to the medial one was found in both sit-to-stand (medial 2.9mm ± 0.7mm, lateral 7.1mm ± 0.6mm) and lunge (medial 5.3mm ± 0.9mm, lateral 10.9mm ± 0.7mm) motor tasks, thus resulting in a medial pivot pattern in about 70% of patients. Significant positive correlation in sit-to-stand was found between the peak of AP translation in the lateral compartment and clinical scores (r = 0.59 for Knee Society Score clinical and r = 0.61 for Oxford). Moreover, we found that the higher peak of AP translation of the medial compartment correlated with lower clinical scores (r = − 0.55 for Knee Society Score clinical, r = − 0.61 for Womac and r = − 0.53 for Oxford) in the lunge. A negative correlation was found between Knee Society Score clinical and VV laxity during sit-to-stand (r = − 0.56) and peak of external rotation in the lunge motor task (r = − 0.66). Conclusions: The MS-TKA investigated produced in vivo a medial pivot movement in about 70% of patients in both examined motor tasks. There was a correlation between the presence of medial pivot and higher post-operative scores. Level of evidence: IV.

Purpose To investigate if postoperative clinical outcomes correlate with specific kinematic patterns after total knee arthroplasty (TKA) surgery. The hypothesis was that the group of patients with higher clinical outcomes would have shown postoperative medial pivot kinematics, while the group of patients with lower clinical outcomes would have not. Methods 52 patients undergoing TKA surgery were prospectively evaluated at least a year of follow-up (13.5 ± 6.8 months) through clinical and functional Knee Society Score (KSS), and kinematically through dynamic radiostereometric analysis (RSA) during a sit-to-stand motor task. Patients received posterior-stabilized TKA design. Based on the result of the KSS, patients were divided into two groups: “KSS > 70 group”, patients with a good-to-excellent score (93.1 ± 6.8 points, n = 44); “KSS n = 8). The anteroposterior (AP) low point (lowest femorotibial contact points) translation of medial and lateral femoral compartments was compared through Student’s t test (p Results Low point AP translation of the medial compartment was significantly lower (p 70 (6.1 mm ± 4.4 mm vs 10.7 mm ± 4.6 mm) and the KSS p > 0.05) between the two groups, while the AP translation of the medial femoral compartment was significantly higher for the KSS > 70 group (p = 0.0442). Conclusion In the group of patients with a postoperative KSS Level of evidence II.

Purpose To compare weight-bearing cone-beam computer tomography (CBCT) and conventional computer tomography (CT)-based measurements of patellofemoral alignment and stability in patients surgically treated for recurrent patellar dislocation. These scans implied respectively single-leg up-right posture, the knee flexed, and lower limb muscles activation, versus supine position with the knee extended. Methods A total of 17 patients (11 males/6 females) after surgical reconstruction with fascia lata allograft for recurrent patellofemoral dislocation were analyzed at 60-month follow-up. Tilt and congruence angles and tibial tuberosity–trochlear groove (TT-TG) offset were measured on images obtained from CBCT and conventional CT scans by three independent and expert radiologists. Paired t tests were performed to compare measurements obtained from the two scans. Inter-rater reliability was assessed using a two-way mixed-effects model intra-class correlation coefficient (ICC). Results Only TT-TG offset was found significantly smaller (p Conclusion In patients surgically treated for recurrent patellar dislocation, TT-TG offset was found overestimated with conventional CT. All measurements of patellofemoral stability and alignment were found more consistent when obtained with weight-bearing CBCT compared to conventional CT.

Introduction Injuries involving the tarsometatarsal (TMT) joint are relatively uncommon, and the surgical treatment is potentially characterized by a high complications rate. The purpose of this study is to evaluate the results of the treatment of Lisfranc fracture-dislocations treated with closed reduction and percutaneous fixation with K-wires, considering complications and re-intervantion rate. Materials and methods A retrospective review was performed on all patients undergone closed reduction and percutaneous fixation with K-wires of a Lisfranc fracture-dislocation. Patients have been clinically evaluated at last follow up by American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score and Visual Analogue Scale (VAS), as well as by radiograph assessment. Results Following inclusion and exclusion criteria, 15 patients have been included, with a mean age of 48.2 ± 5.6 years. Average follow-up was 3.8 ± 1.8 years (range 1–6). 7 fractures analyzed were classified as type A, 7 as type B (3 were B1, 4 were B2) and 1 as type C1. No case of loss of reduction has been observed at radiographic 1-month follow-up. At last follow-up mean AOFAS midfoot score and VAS score were respectively 82.2 ± 10.4 and 1.5 ± 1.3. Registered complications showed one deep vein thrombosis and 2 cases of complex regional pain syndrome (CRPS). One patient subsequently underwent arthrodesis of the tarsometatarsal joint for post-traumatic arthritis. Conclusions The treatment of the fracture-dislocations of the Lisfranc joint by percutaneous reduction and fixation with K-wire can achieve good clinical outcomes with a low rate of complications and reoperations. Level of Evidence Level IV

Purpose This work presents a kinematic evaluation of a cruciate retaining highly congruent mobile bearing total knee arthroplasty design using dynamic Roentgen sterephotogrammetric analysis. The aim was to understand the effect of this implant design on the kinematics of prosthetic knees during dynamic activities. Methods A cohort of 15 patients was evaluated at nine month follow-up after surgery. The mean age was 74.8 (range 66–85) years. The kinematics was evaluated using the Grood and Suntay decomposition and the Low-Point (LP) methods. Results ?tlsb=-0.15pt?>From sitting to standing up position, the femoral component internally rotated (from − 11.3 ± 0.2° to − 7.0 ± 0.2°). Varus–valgus rotations were very close to 0° during the whole motor task. LP of medial condyle moved from an anterior position of 12.0 ± 0.2 mm to a posterior position of − 12.4 ± 0.2 mm; LP of the lateral condyle moved from an anterior position of 8.1 ± 0.2 mm to a posterior position of − 12.4 ± 0.2 mm, showing a bi-condylar rollback where both condyles moved parallel backward. Moreover, the femoral component showed anterior translation with respect to the tibia from 80° to 20° (from − 4.9 ± 0.2 mm to 3.3 ± 0.2 mm), then a posterior translation from 20° to full extension was identified (from 3.3 ± 0.2 mm to 0.5 ± 0.2 mm). Conclusions Paradoxical anterior femoral translation and absence of medial-pivoting motion were recorded, highlighting the role of the symmetric deep dishes insert as main driver of the kinematic of this TKA design.

Purpose: The present review aims to analyse the available literature regarding the use of navigation systems in ACL reconstructive surgery underling the evolution during the years. Methods: A research of indexed scientific papers was performed on PubMed and Cochrane Library database. The research was performed in December 2015 with no publication year restriction. Only English-written papers and related to the terms ACL, NAVIGATION, CAOS and CAS were considered. Two reviewers independently selected only those manuscripts that presented at least the application of navigation system for ACL reconstructive surgery. Results: One hundred and forty-six of 394 articles were finally selected. In this analysis, it was possible to review the main uses of navigation system in ACL surgery including tunnel positioning for primary and revision surgery and kinematic assessment of knee laxity before and after different surgical procedures. In the early years, until 2006, navigation system was mainly used to improve tunnel positioning, but since the last decade, this tool has been principally used for kinematics evaluation. Increased accuracy of tunnel placement was observed using navigation surgery, especially, regarding femoral, 42 of 146 articles used navigation to guide tunnel positioning. During the following years, 82 of 146 articles have used navigation system to evaluate intraoperative knee kinematic. In particular, the importance of controlling rotatory laxity to achieve better surgical outcomes has been underlined. Conlusions: Several applications have been described and despite the contribution of navigation systems, its potential uses and theoretical advantages, there are still controversies about its clinical benefit. The present papers summarize the most relevant studies that have used navigation system in ACL reconstruction. In particular, the analysis identified four main applications of the navigation systems during ACL reconstructive surgery have been identified: (1) technical assistance for tunnel placement; (2) improvement in knowledge of the kinematic behaviour of ACL and other structures; (3) comparison of effectiveness of different surgical techniques in controlling laxities; (4) navigation system performance to improve the outcomes of ACL reconstruction and cost-effectiveness. Level of evidence: IV.

In literature, the reported incidence of posterior cruciate ligament injury ranges from 1% in people involved in sport activities to 44% in people involved in non-sport-related trauma [1]. Moreover, while isolated PCL lesions are more frequent in athletes, Fanelli et al. [2] demonstrated that 95% of PCL injuries observed in an emergency department are combined with other ligamentous lesions. Among these combined injuries, PCL and medial collateral ligament (MCL) lesions are relatively rare (9.4% of multiple ligament injuries involving PCL), and they are challenging regarding diagnosis as well as treatment. We report the case of a middle-aged man with a chronic posteromedial laxity treated with a one-step procedure, using autologous hamstrings.

The hypothesis was that an alteration of different surgical variables of ACL reconstruction would produce significant changes in post-operative static laxity of knee joint. Joint laxity was acquired by a surgical navigation system for 17 patients just after graft fixation during single-bundle reconstruction with extra-articular lateral tenodesis. The analysed laxity parameters were: internal/external rotation at 30° (IE30) and 90° (IE90) of flexion, varus/valgus rotation at 0° (VV0) and 30° (VV30) of flexion and anterior/posterior displacement at 30° (AP30) and 90° (AP90) of flexion. As surgical variables, the angles between the tibial tunnel and the three planes were defined as well as the lengths of the tunnel and the relationship between native footprints and tunnels. The same analysis was performed for the femoral side. All surgical variables were combined in a multivariate analysis to assess for predictive factors between them and post-operative laxities values. To quantify the performance of each multivariate model, the correlation ratio (η 2) and the corresponding P value (*P

This book covers the basics of meniscus anatomy, biomechanics and, importantly, techniques to address meniscal preservation. Sections of the book cover three distinct areas for consideration: pre-operative issues and decision-making, detailed and well-illustrated surgical techniques, and post-operative issues including outcome and rehabilitation. A thorough overview of the current concepts surrounding MAT by world-leading experts is provided. It will also serve as a template for current clinical paradigms, as well as provide guidance as to where future research could be directed. Members of the International Meniscus Reconstruction Experts Forum (IMREF) have combined to bring together this comprehensive review of MAT.

Since the launch of this course format during the 10th EFORT Congress in Vienna in 2009, the EFORT Comprehensive Review Course (CRC) has been a huge success and sold out months ahead of time. Created during Pierre Hoffmeyer’s time as President of EFORT, the CRC aims to provide the knowledge and skills required by every specialist, and to broaden the participant’s orthopaedic horizon. This course provides up-to-date presentations in five major areas: Lower extremity Upper extremity Spine Pediatrics Basic science The CRC usually takes place parallel to the Annual Congress. Therefore, registration for this course comes in addition to the Congress’ registration.

Although anterior cruciate ligament (ACL) reconstruction has a high success rate, a substantial number of patients are left with unsatisfactory results. Revision ACL Reconstruction: Indications and Technique provides detailed strategies for planning and executing revision ACL reconstructions. Concise chapters by a leading group of international orthopedic surgeons cover the diagnosis of failed ACL reconstruction, patient evaluation, preoperative planning for revision ACL surgery and complex technical considerations.

Background: There have been no direct in vivo biomechanical comparisons performed between an anatomic double-bundle (ADB) and a nonanatomic double-bundle (NADB) anterior cruciate ligament (ACL) reconstruction. Hypothesis: There are differences in kinematic outcomes between ADB and NADB ACL reconstruction techniques. Study Design: Controlled laboratory study. Methods: Twenty-six consecutive patients (mean age, 30 years; range, 18-32 years; 23 men, 3 women; 17 right knees, 9 left knees) with an isolated ACL injury were included in the study. The first 13 consecutive patients underwent NADB reconstruction (combination of a single-bundle and an over-the-top reconstruction), and the following 13 consecutive patients were treated with an ADB approach (using 2 tibial tunnels and 2 femoral tunnels placed in the center of the native femoral and tibial insertion sites). Grafts were pretensioned at 80 N and secured with cortical fixation systems under manual maximum force tension. Standard clinical laxity and pivot-shift tests were quantified at time zero before and after ACL reconstruction by means of a surgical navigation system dedicated to kinematic assessment; displacement of the medial and lateral compartments during the tests was also analyzed. Results: The ADB-reconstructed knees showed a larger preoperative-to-postoperative difference in anterior-posterior tibial plateau displacement of the medial and lateral compartments when compared with the NADB-reconstructed knees during the internal-external rotation test at 30° of flexion ( P < .050). No other significant differences in laxity or pivot-shift values were noted. The mean surgical time for ADB reconstruction was significantly higher than that for NABD reconstruction (62 ± 13 and 43 ± 10 minutes, respectively; P < .0001). Conclusion: Results showed a greater anterior-posterior translation of both compartments during the rotational passive laxity test in the ADB reconstruction group or overconstraint caused by the NADB technique. The 2 analyzed double-bundle ACL reconstructions did not show any significant quantitative difference in isolated anterior-posterior laxity and pivot-shift phenomenon at time zero. Clinical Relevance: Nonanatomic double-bundle ACL reconstruction can control anterior-posterior laxity and the pivot-shift phenomenon as well as ABD ACL reconstruction.

In this chapter we analyze our experience concerning ACL lesion with an associated peripheral instability, as peripheral structures are getting more and more attention. We know that combined damage of the ACL and the posterolateral structures of the knee have been associated to Chronic anterior cruciate ligament laxity, in particular rotational laxity associated with a severe pivot-shift test (PST). Posterolateral structures, that may not have been yet directly identified, probably act as secondary restraints to the PST, supplementing the primary restraint role of the ACL in anteroposterior laxity, with emphasis on rotatory laxity and internal rotation. The persistence of this rotatory laxity has been reported even after cases of uneventful ACL reconstruction, suggesting that a single-bundle intra-articular reconstruction could not be sufficient to completely restore rotational knee stability in certain patients (Tashman et al, Am J Sports Med 32(4):975–983, 2004). The rationale behind extra-articular plasty is therefore to create a restraint in internal tibial rotation, and that’s why we adopted in our Institute since 1993 Marcacci’s technique with good results and good graft survivorship. Authors who favour the supplementary extra-articular plasty to standard ACL reconstruction, report the reduction of the PST and lateral tibial translation, however the introduction of evidence-based inclusion criteria for any similar technique as a primary or a revision option,is difficult and remains sporadical and empirically-based.

Chronic anterior cruciate ligament (ACL) laxity, and in particular rotational laxity associated with a severe positive pivot-shift test (PST), has been associated to the combined damage of the ACL and the posterolateral structures of the knee [6, 26, 32]. Other authors have also recorded possible evidence of damage of these structures along with ACL tears with the presence of the “Segond fracture” that results from avulsion of the iliotibial band (ITB) or the “anterior oblique band” of the lateral collateral ligament (LCL) [8]. Further evidence of the gross instability after ACL and lateral structures damage is the lateral tibial subluxation and the subsequent “bone bruising” observed in magnetic resonance imaging [11, 37]. As Dodds and Amis have recently published, these posterolateral structures may not have been yet directly identified, but probably act as secondary restraints to the PST, supplementing the primary restraint role of the ACL in anteroposterior laxity, with emphasis on rotatory laxity and internal rotation [15]. The persistence of this rotatory laxity has been reported even after cases of uneventful ACL reconstruction, suggesting that a single-bundle intra-articular reconstruction could not be sufficient to completely restore rotational knee stability in certain patients [38].

The Adult ACL world is constantly changing and is in need of continual updates; approximately 60,000-75,000 ACL reconstructions are performed annually in the United States. Dr. Freddie Fu just held a world-wide symposium on this topic and is considered the expert. In the Clinics survey sent in the fall of 2010, survey takers were most interested in seeing an issue on ACL repair and injury prevention.

A biodegradable, hyaluronian-based biocompatible scaff old is used for autologous chondrocyte implantation (ACI) for the treatment of articular cartilage lesions. This procedure consists of two steps: the fi rst one is an arthroscopic biopsy of healthy cartilage for chondrocyte cell culture. After 6 weeks, the bioengineered tissue obtained can be implanted trough a mini-open procedure or arthroscopic technique.

Abbiamo dimostrato in un precedente studio che i pazienti con lesioni combinate del legamento crociato anteriore (LCA) e del legamento collaterale mediale (LCM) presentano simili lassità in antero-posteriore (AP), ma un maggiore valgo a 30° di flessione dopo la ricostruzione del LCA, rispetto ai pazienti che hanno subito una ricostruzione isolata di del LCA. Il presente studio ha valutato la stessa coorte di pazienti ad un minimo di tre anni di follow-up per valutare se la lassità residua in valgo abbia portato a peggiori risultati clinici. Ogni paziente ha subito una ricostruzione artroscopica a doppio-fascio del LCA utilizzando un innesto di semitendinoso-gracile. Nella gruppo LCA/LCM, la lesione di II grado del legamento collaterale mediale non è stata trattata. Al follow-up, la lassità in AP è stata misurata utilizzando un artrometro KT-2000, mentre la lassità in valgo è stata valutata mediante radiografia e Telos, confrontando l’arto operato con il ginocchio illeso. Abbiamo valutato i punteggi dei risultati clinici ottenuti, della circonferenza muscolare e il tempo necessario al ritorno in attività per i due gruppi. Le radiografie con stress in valgo hanno mostrato una maggiore differenza statistica nell’apertura mediale del gruppo LCA/LCM rispetto all’arto sano (1,7 mm (SD 0,9) rispetto a 0,9 mm (SD 0,7), rispettivamente, p = 0,013), mentre nessuna differenza statisticamente significativa è stata rilevata nelle lassità in AP e negli altri parametri clinici. I nostri risultati mostrano che la lassità residua in valgo non influisce in modo significativo ad un minimo di follow-up di tre anni, il che suggerisce che nessuna procedura chirurgica aggiuntiva è necessaria per il trattamento del legamento collaterale mediale nelle lesioni combinate.

Background: Loss of meniscal tissue can be responsible for increased pain and decreased function. Hypothesis: At a minimum 10-year follow-up, patients receiving a medial collagen meniscus implant (MCMI) would show better clinical, radiological, and magnetic resonance imaging (MRI) outcomes than patients treated with partial medial meniscectomy (PMM). Study Design: Cohort study; Level of evidence 2. Methods: Thirty-three nonconsecutive patients (men; mean age, 40 years) with meniscal injuries were enrolled in the study to receive MCMI or to serve as a control patient treated with PMM. The choice of treatment was decided by the patient. All patients were clinically evaluated at time 0 and at 5 years and a minimum of 10 years after surgery (mean follow-up, 133 months) by Lysholm, visual analog scale (VAS) for pain, objective International Knee Documentation Committee (IKDC) knee form, and Tegner activity level scores. The SF-36 score was performed preoperatively and at final follow-up. Bilateral weightbearing radiographs were completed before the index surgery and at final follow-up. Minimum 10-year follow-up MRI images were compared with preoperative MRI images by means of the Yulish score. The Genovese score was also used to evalute MCMI MRI survivorship. Results: The MCMI group, compared with the PMM one, showed significantly lower VAS for pain (1.2 ± 0.9 vs 3.3 ± 1.8; P = .004) and higher objective IKDC (7A and 10B for MCMI, 4B and 12C for PMM; P = .0001), Teger index (75 ± 27.5 vs 50 ± 11.67; P = .026), and SF-36 (53.9 ± 4.0 vs 44.1 ± 9.2; P = .026 for Physical Health Index; 54.7 ± 3.8 vs 43.8 ± 6.5; P = .004 for Mental Health Index) scores. Radiographic evaluation showed significantly less medial joint space narrowing in the MCMI group than in the PMM group (0.48 ± 0.63 mm vs 2.13 ± 0.79 mm; P = .0003). No significant differences between groups were reported regarding Lysholm ( P = .062) and Yulish ( P = .122) scores. Genovese score remained constant between 5 and 10 years after surgery ( P = .5). The MRI evaluation of the MCMI patients revealed 11 cases of myxoid degeneration signal: 4 had a normal signal with reduced size, and 2 had no recognizable implant. Conclusion: Pain, activity level, and radiological outcomes are significantly improved with use of the MCMI at a minimum 10-year follow-up compared with PMM alone. Randomized controlled trials on a larger population are necessary to confirm MCMI benefits at long term.

The purpose of this study was to compare subjective, objective and radiographic outcome of the lateralized single-bundle bone-patellar tendon-bone autograft with a non-anatomical double-bundle hamstring tendons autograft anterior cruciate ligament (ACL) reconstruction technique at long-term follow-up. Seventy-nine non-consecutive randomized patients (42 men; 37 women) with unilateral ACL insufficiency were prospectively evaluated, before and after ACL reconstruction by means of the above-mentioned techniques, with a minimum follow-up of 8 years (range 8–10 years; mean 8.6 years). In the double-bundle hamstrings technique, we used one tibial and one femoral tunnel combined with one “over-the-top” passage, cortical staple’s fixation and we left intact hamstrings’ tibial insertion. Patients were evaluated subjectively and objectively, using IKDC score, Tegner level, manual maximum displacement test with KT-2000™ arthrometer. Radiographic evaluation was performed according to IKDC grading system, and re-intervention rate for meniscal lesions was also recorded. The subjective and objective IKDC were similar in both groups while double-bundle hamstrings group showed significantly higher Tegner level (P = 0.0007), higher passive range of motion recovery (P = 0.0014), faster sport resumption (P = 0.0052), lower glide pivot-shift phenomenon (P = 0.0302) and lower re-intervention rate (P = 0.0116) compared with patellar tendon group. Radiographic evaluation showed significant lower objective degenerative changes in double-bundle hamstrings group at final follow-up (P = 0.0056). Although both techniques provide satisfactory results, double-bundle ACL reconstruction shows better functional results, with a faster return to sport activity, a lower re-operation rate and lower degenerative knee changes.

Nowadays the demand for Unicompartmental Knee Replacement (UKR) for the treatment of degenerative arthritis or osteonecrosis of a single compartment of the knee is increasing. The procedure has significantly evolved through the past three decades and we present an extended review of the literature on this topic. A detailed historical overview is reported, in order to follow the subsequent hypothesis that have led to the modern state of the art in Minimally Invasive Surgery (MIS) for UKR and to the resurgence of the concept of interpositional hemiarthroplasties. We have also performed a review of the literature regarding the evolution of indications and contraindications for a UKR, as well as pre-operative evaluation and surgical technique. In separated sections, we have also reported findings and concepts regarding lateral UKR and its surgical technique and also recent diffusion of bi-unicompartmental procedures. A wide section is dedicated to the discussion about different implant designs, considering their biomechanical and kinematics basis and to generally accepted guidelines for the correct implant positioning. The recent advances in Computer Aided Surgery (CAS) related to UKR are also discussed. Finally, we have analysed the modes of failure of UKRs and their surgical implications and the topic of the revision procedures for a failed UKR