Abstract. Objectives. The study aims to determine whether an arthroscopic ligament reconstruction is necessary to relieve clinical ankle instability symptoms in patients with an MRI scan showing medial or lateral ligament tear. Methods. This was a single centre retrospective case series study of 25 patients with ankle instability and ligament tear on MRI scan who had undergone arthroscopic procedures from January 2015 to December 2018. Patients were followed up for an average period of 3 years postoperatively to check for any recurrence of symptoms. Results. Of the 25 patients, 23 had ATFL tear on MRI scan, and 2 had deltoid ligament tear. Examination under anaesthesia was stable in 13 patients and unstable in 12 patients. The majority of the patients (76%) had a simple arthroscopic ankle debridement and no ligament repair. Six patients needed Brostrom repair. Conclusions. Our study has shown that in patients with MRI proven ligament tear and clinical instability, a ligament reconstruction was unnecessary in most patients. The instability symptoms of patients were relieved by simple ankle arthroscopic debridement

Introduction. Ligament reconstruction following knee soft tissue injuries, such as posterior cruciate ligament (PCL) tears, aim to restore normal joint function and motion; however, persistant pathomechanical joint behavior indicates that there is room for improvement in current reconstruction techniques. Increased attention is being directed towards the roles of secondary knee stabilizers, in an attempt to better understand their contributions to kinematics of knees. The objective of this study is to characterize the relative biomechanical contributions of the posterior oblique ligament (POL) and the deep medial collateral ligament (dMCL) in PCL-deficient knees. We hypothesized that, compared with the POL, the dMCL would have a more substantial role in stabilizing the medial side of the knee, especially in flexion (slack POL). Methods. Seven fresh-frozen cadaveric knees were used in this study (age 40–62, 4 female, 3). Specimens were potted and mounted onto a VIVO joint motion simulator (AMTI). Once installed, specimens were flexed from 0 to 90 degrees with a 10 N axial load and all remaining degrees of freedom unconstrained. This was repeated with (a) a 67 N posterior load, (b) a 2.5 Nm internal or external rotational moment and (c) a 50 N posterior load and 2.5 Nm internal rotational moment applied to the tibia. During each resulting knee motion, the relative AP kinematics of the dMCL tibial insertion (approximated as the most medial point of the proximal tibia) with respect to the flexion axis of the femur (the geometric center axis, based on the posterior femoral condyles) were calculated at 0, 30, 60 and 90 degrees of flexion. These motions were repeated following dissection of the PCL and then further dissection of either medial ligament (4 POL, 3 dMCL). The changes in AP kinematics due to ligament dissection were analyzed using three-way repeated-measures ANOVA with a significance value of 0.05. Results. Dissection of the dMCL or POL did not result in a statistically significant increase in the posterior displacement of the medial tibial point under posterior directed force, internal rotation moments, or the combined posterior force plus internal rotation moment. Interestingly, under external moment loading, there was a statistically significant increase in anterior displacement of the medial tibia at all flexion angles after POL dissection, by up to 3.0+/−2.6 mm at 0 degrees. Dissection of the dMCL, however, did not have a significant affect. Conclusion. Our results showed that neither the POL nor dMCL play a significant role in resisting posterior tibial displacements on the medial side of a PCL deficient knee. Of the two, the POL appears to have a greater contribution towards preventing anterior translations, particularly when in extension. This finding is rational based on the anatomical path of this ligament wrapping around the femoral medial condyle under external rotational moments. In contrast with our hypothesis, it was observed that the dMCL had less of an effect on medial knee stability. Contributions of these ligaments could be further investigated using more complicated loading, such as those more representative of activities of daily living

Modeling the kinetic effects of the soft tissue structures is a major challenge for dynamic simulation of knees and other joints. We describe a technique whereby a multi-fiber ligament model is evolved to reproduce accurately the passive kinetics of a knee joint. The passive motion can be derived from patient-specific motion capture data. It may also be derived in-silico from a desired articular surface geometry, for example an implant or a surface model acquired by radiography. The technique operates by optimizing the tibial ligament insertion sites to minimize the change in strain energy through a specified range of motion. It is believed that the ligament model so produced is valuable for loaded kinetic and kinematic joint studies as well. The results therefore may be used to inform implant positioning during surgical planning

Poor availability of allografts in South Africa has led to an increased use of synthetic augmentation to stabilize knee joints in the treatment of knee dislocations. This study aims to evaluate multiligament knee injuries treated with a posterior cruciate ligament internal brace. The study included patients with knee dislocations who were treated with a PCL internal brace. The internal brace involved the insertion of a synthetic suture tape, which was drilled into the femoral and tibial footprint. Chronic injuries were excluded. Patient-reported outcome scores (PROMs), range of motion, stress X-Rays, and MRI scans were reviewed to assess outcomes. Acceptable outcomes were defined as a Lysholm score of 84 or more, with grade II laxity in no more than one ligament and a range of motion from full extension to 90° or more. The study included eight patients, with a median age of 42, of which five were female. None of the patients had knee flexion less than 90° or an extension deficit of more than 20°. PROMs indicated acceptable outcomes (EQ5D, Tegner Lysholm). Stress radiographs showed less than 7mm (Grade I) of posterior translation laxity in all patients. Four patients underwent MRI scans 1–2 years after the initial surgery, which revealed healing of the PCL in all patients. However, increased signal in a continuous ligament suggested only partial healing in two patients. Tunnel widening of 200% and 250% was noted around the tibial and femoral PCL footprints, respectively. All patients demonstrated stable knees and acceptable PROMs. Tunnel widening was observed in all patients who had MRI scans. Factors such as suspensory fixation, anisometric tunnel position, and the absence of PCL tear repair may have contributed to the tunnel widening

Acromioclavicular joint injuries are one of the most common injuries in the shoulder girdle complex. Surgical management is considered based on patient profile, level of activity, pain, and classification of injury. To date, a vast array of surgical techniques have been proposed and described in the literature, a possible reason being that the optimal solution is still uncertain. The aim of this study is to determine the efficacy of an alternative surgical technique. This study is a retrospective case series of 80 patients that have been operated by a single surgeon over a period of 6 years. A novel surgical technique, the ‘BiPOD method’, was applied where a synthetic artificial ligament (LARS®) is used to reconstruct and reduce the acromioclavicular joint. The technique is done in a reproducible manner, where a single continuous artificial ligament is used to reduce and reconstruct both, the coracoclavicular and acromioclavicular ligament complexes to achieve bidirectional stability. Patients were followed-up postoperatively, either clinically where possible or telephonically. The Acromioclavicular Joint Instability Score (ACJI) and radiographic measurements were used to determine the clinical and surgical outcome of the surgery. Radiographic parameters, measuring the reduction of the coracoclavicular- and acromioclavicular joint, were analysed and documented. The results showed marked improvement in both, the coracoclavicular distance and acromioclavicular distance. Clinically, using the ACJI scoring system, the patients reported substantial improvement in pain and function. Complications were recorded but were insignificant. The BiPOD surgical technique, making use of an artificial LARS® ligament, has proven acceptable outcomes in the surgical management of acromioclavicular joint dislocations

Introduction. The convincible wisdom is that the release of MCL in severe varus knee should be progressive. This release is usually carried on after resecting the osteophyte and gradually carried on until the MCL is well balanced. However, sometimes, extensive release and releasing the superficial MCL can lead to instability in flexion. On a personal communication with many Asian surgeons they have been doing a careful release of the posteromedial corner in the varus knee and in majority of cases such release is adequate. And even in severe cases of varus knee superficial MCL doesn't need to be released. 20 total knee replacements were performed by the same surgeon using ZimmerPS implant. In the varus deformity ranges from 15–35 degrees. The first bony section was made carefully. All osteophytes were removed and resected. The posterior bone osteophytes were also resected and the intercondylar notches were made along with the posterior release. After doing the bony cut in 18 of those cases the medial compartment was still tight and both flexion and extension. A careful release was carried in the postal medial corner-First using an osteotome around the posteromedial corner to release the soft tissue. After that the thick fibrous tissue that formed like pseudo meniscus was also resected until we were able to reach the posterior capsule. In some cases those scar tissues even extended to the capsule requiring the resecting of the postal medial capsule. We meticulously resected all those scar tissues and in many of those cases were able to visualize the MCL ligament which was well preserved. A tensioning device was used before and after the release. In all of those cases we were able to document an opening ranging from two to seven millimeter after the proper release. In all cases the superficial MCL were still intact and can be operated carefully. Result. This study clearly shows that we did not have to release the superficial MCL and the careful posteromedial release was adequate to obtain a good balance gap immediately and the knee was quite stable. The superficial MCL was maintained and preserved and tensioning device clearly document opening after releasing the postural medial corner. Discussion. In varus knee there is an extensive scar tissue which can sometimes tension the mcl ligament and releasing the deep mcl along with posture medial corner without releasing the superficial will preserve the stability of the knee allowing us to ambulate the patient immediately and preventing instability. Conclusion. Although MCL release has been described in diff ways in multiple literatures, little attention has been paid to the posture medial corner. This paper clearly shows that the complex anatomy of the posture medial corner along with scarring can lead to a tight mcl Releasing such structures would balance MCL&LCL without compromising the superficial MCL which normally lead to obvious flexion instability and a mid-section instability. We strongly recommend surgeon to do the posteromedial release before doing any release to the superficial mcl. Doing so will prevent the incidence of instability after extensive release in varus deformity

Ligament releases are necessary for contemporary non-conforming femoral-tibial articulations. Most total knee arthroplasty prostheses are designed to be non-conforming at the articulation between the femoral and tibial components. This design is chosen on the arthroplasty principle that “constraint causes loosening” and conforming surfaces have been considered constrained. To provide stability the ligaments are adjusted so that tension in the ligament can provide stability for the total knee replacement. Ligament releases are NOT necessary for contemporary conforming femoral-tibial articulations. Through the majority of the range of motion, the normal human knee is not stabilised by ligament tension. Rather, it is the geometrical conformity of the femur and tibia, especially on the medial side, that provides stability. The ligaments are present and ready to restrain the knee from excess varus-valgus or anterior-posterior loads. In a knee design that is congruent, ligaments may be left intact as in the normal knee, ready to provide restraint but not necessarily to provide stability except when excess loads are applied to the knee. When designing and using the ADVANCE Medial Pivot total knee, the author has left ligaments in the toe-region of the stress-strain curve rather than releasing and tensioning the ligaments. Patient satisfaction survey data at routine follow-up visits for patients at 7–15 years after arthroplasty with this type of reconstruction indicate high satisfaction despite medial and lateral opening (on valgus and varus stress) that would be considered “mid-flexion instability” for non-conforming joints that require careful ligament releases and tensioning

Trapeziectomy with ligament reconstruction and tendon interposition (LRTI) with the flexor carpi radialis (FCR) tendon is one of the most common procedures for the treatment of thumb carpometacarpal (CMC) arthritis. An alternative method involves trapeziectomy alone (TA). The trapeziectomy with LRTI procedure was developed to theoretically improve biomechanical strength and hand function when compared to TA, which leaves an anatomical void proximal to the first metacarpal. The LRTI procedure takes longer to perform and includes an autologous tendon graft. The goal of this retrospective cohort study was to evaluate the clinical outcomes of trapeziectomy with or without LRTI at a minimum follow-up of 1 year. A total of 43 adult patients who had underwent a total of 58 (TA=36, LRTI=22) surgical procedures for CMC arthritis participated in the study. This single surgeon retrospective cohort study sampled patients who underwent CMC arthroplasty with either TA or LRTI techniques between 2008 and 2020 with a minimum time of 1 year post-operatively. The patients were evaluated subjectively (The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire) and objectively (hand/thumb strength, pre/post-operative hand radiographs). Both the TA and LRTI procedures provided good pain relief, motion, strength, and stability without any severe complications. There was no statistically significant difference in hand or thumb strength between the two groups. Radiography showed that compared to the preoperative status, the trapezial space decreased similarly between the two groups. There was no difference in size of collapse between TA and LRTI post-operatively. The TA procedure had similar outcomes to LRTI and has the advantages of shorter surgical time, less incision length, and lower surgical complexity. TA provided equivalent trapezial space to LRTI after the operation. Future study should investigate these two procedures in a head-to-head comparison rather than longitudinally where both surgeon experience and time since procedure at follow-up may have impacted results

There is no consensus for the appropriate surgical management of chronic ulnar collateral ligament (UCL) injuries of the thumb. A systematic review of Pubmed, MEDLINE, EMBASE and ePub Ahead of Print was performed in accordance with Preferred Reporting of Items in Systematic Review and Meta-analysis (PRISMA) guidelines and formal protocol registered with PROSPERO. Two authors collated data from 10 studies that met strict inclusion criteria, using various surgical techniques in 131 thumbs. Results were heterogenous and metanalysis of results not possible. These data were, therefore, qualitatively assessed and synthesised. Bias was assessed using the ROBINS-I tool. Direct repair, reconstruction with free tendon or bone-tissue-bone grafts and arthrodesis all demonstrated favourable outcomes with Patient Reported Outcome Measures. Direct repair can be safely performed more than two months following injury, with a positive mean Disabilities of the Arm, Shoulder and Hand (DASH) score of 13.5 despite evidence of radiographic osteoarthritis. Arthrodesis should be considered in heavy manual laborers or those at risk of osteoarthritis as it provides significant reduction in pain (Mean Visual Analogue Score of 1.2) when compared to other methods. Free tendon grafting has been criticised for failure rates and poor functional grip strength, however collated analysis of 97 patients found a single graft rupture and mean grip strength of 97% (of the contralateral thumb). Bone-tissue-bone grafting was the least effective method across all outcome measures. Studies included were at high risk of bias, however, it can be concluded that delayed direct repair can be performed safely, while arthrodesis may benefit certain patient subgroups. New findings suggest poor efficacy of bone-tissue-bone grafts, but that free tendon grafting with palmaris longus are in fact safe with good restoration of grip strength. The optimal graft and configuration are yet to be determined for reconstructive methods

INTRODUCTION. Proper ligament engagement is an important topic of discussion for total knee arthroplasty; however, its importance to total ankle arthroplasty (TAA) is uncertain. Ligaments are often lengthened or repaired in order to achieve balance in TAA without an understanding of changes in clinical outcomes. Unconstrained designs increase ankle laxity,. 1. but little is known about ligament changes with constrained designs or throughout functional activity. To better understand the importance of ligament engagement, we first investigated the changes in distance between ligament insertions throughout stance with different TAA designs. We hypothesize that the distance between ligaments spanning the ankle joint would increase in specimens following TAA throughout stance. METHODS. A validated method of measuring individual bone kinematics was performed on pilot specimens pre- and post-TAA using a six-degree-of-freedom robotic simulator with extrinsic muscle actuators and motion capture cameras (Figure 1). 2. Reflective markers attached to surgical pins and radiopaque beads were rigidly fixed to the tibia, fibula, talus, calcaneus, and navicular for each specimen. TAAs were performed by a fellowship-trained foot and ankle surgeon on two specimens with separate designs implanted (Cadence & Salto Talaris; Integra LifeSciences; Plainsboro, NJ). Each specimen was CT-scanned after robotic simulations of stance pre- and post-TAA. Specimens were then dissected before a 3D-coordinate measuring device was used to digitize the ligament insertions and beads. Ligament insertions were registered onto the bone geometries within CT images using the digitized beads. Individual bone kinematics measured from motion capture were then used to record the point-to-point distance between centers of the ligament insertions throughout stance. RESULTS. Results from the pilot specimens are presented for the calcaneofibular ligament (CFL) only. The distance between the CFL insertions was larger throughout stance following Cadence implantation (Figure 2A) and was decreased throughout most of stance following Salto Talaris implantation (Figure 2B). The percent change in CFL distance with respect to static standing was also increased with the Cadence implant (Figure 2C) and similar to intact following Salto Talaris implantation (Figure 2D). Ankle motion was similar to intact with the Cadence (Figure 3A) and was decreased with the Salto Talaris (Figure 3B). DISCUSSION. This study suggests that ligament length during stance changes following TAA. The Cadence implant similarly replicated ankle kinematics but CFL length was increased throughout stance which supports our hypothesis. In contrast, the Salto Talaris implant reduced ankle motion and decreased the CFL length. Although the slack length and pre-strain of the CFL were unknown, the distance between insertions from the pilot specimens provides preliminary insight into how ligament mechanics change post-TAA during functional activity. CLINICAL RELEVANCE. Preliminary results of ligament length changes throughout stance may indicate that ligament mechanics change post-TAA and could affect patient outcomes. Changes may be even more pronounced when a soft tissue release or reconstruction is performed to correct malalignment. For any figures or tables, please contact the authors directly

INTRODUCTION. Applying the proper amount of tension to knees collateral ligaments during surgery is a prerequisite to achieve optimal performance after TKA. It must be taken into account that lower values of ligament tension could lead to an instable joint while higher values could induce over-tensioning thus leading to problems at later follow-up: a “functional stability” must then be defined and achieved to guarantee the best results. In this study, an experimental cadaveric activity was performed to measure the minimum tension required to achieve functional stability in the knee joint. METHODS. Ten cadaveric knee specimens were investigated; each femur and tibia was fixed with polyurethane foam in specific designed 3D-printed fixtures and clamped to a loading frame. A constant displacement rate of 0.05 mm/s was applied to the femoral clamp in order to achieve joint stability and the relative force was measured by the machine: the lowest force guaranteeing joint stability was then determined to be the one corresponding to the slope change in the force/displacement curve, representing the activation of the elastic region of both collateral ligaments. The force span between the slack region and the found point was considered to be the tension required to reach the functional stability of the joint. This methodology was applied on intact knee, after ACL-resection and after further PCL-resection in order to simulate the knee behavior in CR and PS implants. The test was performed at 0, 30, 60 and 90° of flexion using a specifically designed device. Each configuration was analyzed three times for the sake of repeatability. RESULTS. Results demonstrated that an overall tension of 40–50N is sufficient to reach stability in native knee with intact cruciate ligaments. Similar values appear to be sufficient in an ACL-resected knee, while higher tension is required (up to 60N) for stability after ACL and PCL resection. Moreover, the tension required for stabilization was slightly higher at 60° of flexion compared to the one required at the other angles, reflecting thus the mid-flection instability behavior. DISCUSSION AND CONCLUSIONS. The results are in agreement to other experimental studies. 1,2. and show that the tensions necessary to stabilize a knee joint in different ligament conditions are way lower than the ones usually applied via tensioners nowadays. To reach functional stability, surgeons should consider such results intraoperatively to avoid laxity, mid-flexion instability or ligament over-tension

Reconstruction of the anterior cruciate ligament (ACL) allows to restore stability of the knee, in order to facilitate the return to activity (RTA). Although it is understood that the tendon autograft undergoes a ligamentous transformation postoperatively, knowledge about longitudinal microstructural differences in tissue integrity between types of tendon autografts (ie, hamstring vs. patella) remains limited. Diffusion tensor imaging (DTI) has emerged as an objective biomarker to characterize the ligamentization process of the tendon autograft following surgical reconstruction. One major limitation to its use is the need for a pre-injury baseline MRI to compare recovery of the graft, and inform RTA. Here, we explore the relationship for DTI biomarkers (fractional anisotropy, FA) between knees bilaterally, in healthy participants, with the hypothesis that agreement within a patient's knees may support the use of the contralateral knee as a reference to monitor recovery of the tendon autograft, and inform RTA. Fifteen participants with no previous history of knee injuries were enrolled in this study (age, 26.7 +/− 4.4 years; M/F, 7/8). All images were acquired on a 3T Prisma Siemens scanner using a secured flexible 18-channel coil wrapped around the knee. Both knees were scanned. A 3D anatomical Double Echo Steady State (DESS) sequence was acquired on which regions of interest (ROI) were placed consistent with the footprints of the ACL (femur, posteromedial corner on medial aspect of lateral condyle; tibia, anteromedial to intercondylar eminence). Diffusion images were acquired using fat saturation based on optimized parameters in-house. All diffusion images were pre-processed using the FMRIB FSL toolbox. The footprint ROIs of the ACL were then used to reconstruct the ligament in each patient with fiber-based probabilistic tractography (FBPT), providing a semi-automated approach for segmentation. Average FA was computed for each subject, in both knees, and then correlated against one another using a Pearson correlation to assess the degree of similarity between the ACLs. A total of 30 datasets were collected for this study (1/knee/participant; N=15). The group averaged FA (+/− standard deviation) for the FBPT segmented ACLs were found to equal 0.1683 +/− 0.0235 (dominant leg) and 0.1666 +/− 0.0225 (non-dominant leg). When comparing both knees within subjects, reliable agreement was found for the FBPT-derived ACL with a linear correlation coefficient (rho) equal to 0.87 (P < 0 .001). We sought to assess the degree of concordance in FA between the knees of healthy participants with hopes to provide a method for using the contralateral “healthy” knee in the comparison of autograft-dependent longitudinal changes in microstructural integrity, following ACL reconstruction. Our results suggest that good agreement in anisotropy can be achieved between the non-dominant and dominant knees using DTI and the FBPT segmentation method. Contralateral anisotropy of the ACL, assuming no previous injuries, may be used as a quantitative reference biomarker for monitoring the recovery of the tendon autograft following surgical reconstruction, and gather further insight as to potential differences between chosen autografts. Clinically, this may also serve as an index to supplement decision-making with respect to RTA, and reduce rates of re-injuries

Background. Achieving good ligament balance in total knee arthroplasty (TKA) is essential to prevent early failure and revision surgery. Poor balance and instability are well-defined, however, an ideal ligament balance target across all patients is not well-understood. In this study we investigate the achieved ligament balance using an imageless, intra-operative dynamic balancing tool and its relation to patient reported outcomes. Methods. A prospective, multi-surgeon, multi-center study investigated the use of a dynamic ligament-balancing tool in combination with a robotic-assisted navigation platform using the APEX knee (OMNI-Corin, Raynham MA). After all resections, the femoral trial and a computer-controlled tensioning device in place of the tibial tray was inserted into the knee joint. The difference in medial and lateral (ML) gaps when balancing the knee under constant load at extension (10°), mid-flexion (30°) and flexion (90°) was captured. Patients completed the KOOS questionnaire at 3 months ± 2 weeks post-surgery and considered the past 7 days as a timeframe for responses. Pearson's correlation was used to determine linear correlations between factors and ANOVA tests were used to determine differences in categorical data. Results. Thirty patients have currently completed 3 months KOOS questionnaires for analysis (age: 68±9.3yrs, Male: 43%). Strong correlations were found between the difference in ML gap for KOOS symptoms and pain in extension (r=−0.54, p=0.002, r=−0.50, p=0.005, respectively) and mid flexion (r=−0.52, p=0.003, r=−0.48, p=0.007, respectively), but not in full flexion (r=−0.13, p=0.5, r=−0.23, p=0.22, respectively). A threshold of 1.5 mm difference in joint gap under constant load was used to distinguish between balanced and more lax knees medially or laterally. Worse KOOS symptoms were found in patients with tighter lateral laxity in extension and mid flexion (△=15 points, p=0.03, △=21 points, p=0.0002, respectively) compared to the rest of the cohort, see Figure 1. Similarly, worse KOOS pain was found for tight lateral laxity in mid-flexion (△=14 points, p=0.02). No significant differences were found in full flexion or for patients with a tight medial side at any flexion angle. Stronger differences in extension and mid flexion may reflect the type of activities and range of motion most commonly encountered as a TKA patient. A younger population engaging higher demand activities may be more sensitive to coronal soft tissue balance in full flexion. Conclusion. Improved patient outcomes were found to correlate with a neutrally-balanced or tighter medial soft tissue profile compared to tighter lateral structures. These results reflect the behaviour of the native knee. The cohort investigated here is small and data collection is ongoing. Further data will be needed to determine if these results can be generalized and to investigate the potential of patient specificity in ideal ligament balancing. For any figures or tables, please contact authors directly

Neer Type-IIB lateral clavicle fractures are inherently unstable fractures with associated disruption of the coracoclavicular (CC) ligaments. A novel plating technique using a superior lateral locking plate with antero-posterior (AP) locking screws, resulting in orthogonal fixation in the lateral fragment has been designed to enhance stability. The purpose of this study was to biomechanically compare three different clavicle plating constructs. 24 fresh-frozen cadaveric shoulders were randomised into three groups (n=8 specimens). Group 1: lateral locking plate only (Medartis Aptus Superior Lateral Plate); Group 2: lateral locking plate with CC stabilisation (Nr. 2 FiberWire); and Group 3: lateral locking plate with two AP locking screws stabilising the lateral fragment. Data was analysed for gap formation after cyclic loading, construct stiffness and ultimate load to failure, defined by a marked decrease in the load displacement curve. After 500 cycles, there was no statistically significant difference between the three groups in gap-formation (p = 0.179). Ultimate load to failure was significantly higher in Group 3 compared to Group 1 (286N vs. 167N; p = 0.022), but not to Group 2 (286N vs. 246N; p = 0.604). There were no statistically significant differences in stiffness (Group 1: 504N/mm; Group 2: 564N/mm; Group 3: 512N/mm; p = 0.712). Peri-implant fracture was the primary mode of failure for all three groups, with Group 3 demonstrating the lowest rate of peri-implant fractures (Group 1: 6/8; Group 2: 7/8, Group 3: 4/8; p = 0.243). The lateral locking plate with orthogonal AP locking screw fixation in the lateral fragment demonstrated the greatest ultimate failure load, followed by the lateral locking plate with CC stabilization. The use of orthogonal screw fixation in the distal fragment may negate against the need for CC stabilization in these types of fractures, thus minimizing surgical dissection around the coracoid and potential complications

The extent of soft-tissue release and the exact structures that need to be released to correct deformity and balance the knee has been a controversial subject in primary total knee arthroplasty. Asian patients often present late and consequently may have profound deformities due to significant bone loss and contractures on the concave side, and stretching of the collateral ligament on the convex side. Extra-articular deformities may aggravate the situation further and make correction of these deformities and restoration of ‘balance’ more arduous. These considerations do not apply if a hinged prosthesis is used, as may be warranted in an elderly, low-demand patient. However, in active, younger patients, it may be best to avoid use of excess constraint by balancing the soft-tissues and using the least constrained implant. Releasing collateral ligaments during TKA has unintended consequences such as the creation of significant mediolateral instability and a flexion gap which exceeds the extension gap; both of these may require a constrained prosthesis to achieve stability. We will show that soft-tissue balance can be achieved even in cases of severe varus, valgus, flexion and hyperextension deformities without collateral ligament release. The steps are: 1) Determining pre-operatively whether deformity is predominantly intra-articular or extra-articular, 2) Individualizing the valgus resection angle and bony resection depth, 3) Meticulous removal of osteophytes, 4) Reduction osteotomy, posteromedial capsule resection, sliding medial or lateral condylar osteotomy, extra-articular corrective osteotomy, 5) Compensating for bone loss, 6)Only rarely deploying a more constrained device. Case examples will be presented to illustrate the entire spectrum of varus deformities

Background. The hip joint capsular ligaments passively restrain extreme range of motion (ROM), protecting the native hip against impingement, subluxation, edge loading and dislocation. This passive protection against instability would be beneficial following total hip arthroplasty (THA), however the reduced femoral head diameter postoperatively may prevent a wrapping mechanism that is essential to capsular ligament function in the native hip. Therefore we hypothesized that, post-THA, the reduced femoral head size would prevent the capsular ligaments protective biomechanical function. Methods. In vitro, THA was performed through the acetabular medial wall preserving the entire capsule, avoiding targeting a particular surgical approach. Eight fresh-frozen cadaveric hips were examined and capsular function was measured by internally/externally rotating the hip in five positions ranging from full extension with abduction, to full flexion with adduction. Three head sizes (28, 32, 36 mm) with three neck lengths (restored native 0, +5, +10 mm) were compared. Results. Internal and external rotation ROM increased following THA, indicating late engagement of the capsule and reduced biomechanical function (p<0.05). Internal rotation was affected more than external. Increasing neck length restored ROM more towards the native condition, but too much lengthening over-constrained external rotation. Increasing head size only had a small effect, restoring ROM towards the native condition. Conclusions. Following THA, the capsular ligaments were unable to wrap around the reduced diameter femoral head to restrain excessive hip movement. The posterior capsule was the most affected, indicating native posterior capsule preservation is not advantageous at least in the short-term. Decreased neck length could cause capsular dysfunction, whilst increased could over-tighten the anterior capsule. Relevance. Increased understanding of soft tissue balancing following THA could help prevent instability, a frequent and long-standing THA complication. This study illustrates how the capsule will function according to its preservation or repair following THA

Alignment of total joint replacement in the valgus knee can be done readily with intramedullary alignment and hand-held instruments. Intramedullary alignment instruments usually are used for the femoral resection. The distal femoral surfaces are resected at a valgus angle of 5 degrees. A medialised entry point is advised because the distal femur curves toward valgus in the valgus knee, and the distal surface of the medial femoral condyle is used as reference for distal femoral resection. In the valgus knee, the anteroposterior axis is especially important as a reliable landmark for rotational alignment of the femoral surface cuts because the posterior femoral condyles are in valgus malalignment, and are unreliable for alignment. Rotational alignment of the distal femoral cutting guide is adjusted to resect the anterior and posterior surfaces perpendicular to the anteroposterior axis of the femur. In the valgus knee this almost always results in much greater resection from the medial than from the lateral condyle. Intramedullary alignment instruments are used to resect the proximal tibial surface perpendicular to its long axis. Like the femoral resection, resection of the proximal tibial surface is based on the height of the intact medial bone surface. After correction of the deformity, ligament adjustment is almost always necessary in the valgus knee. Stability is assessed first in flexion by holding the knee at 90 degrees and maximally internally rotating the extremity to stress the medial side of the knee, then maximally externally rotating the extremity to evaluate the lateral side of the knee. Medial opening greater than 4mm, and lateral opening greater than 5mm, is considered abnormally lax, and a very tight lateral side that does not open at all with varus stress is considered to be abnormally tight. Stability is assessed in full extension by applying varus and valgus stress to the knees. Medial opening greater than 2mm is considered to be abnormally lax, and a very tight lateral side that does not open at all with varus stress is considered to be too tight. Release of tight structures should be done in a conservative manner. In some cases, direct release from bone attachment is best (popliteus tendon); in others, release with pie-crusting technique is safe and effective. In knees that are too tight laterally in flexion, but not in extension, the LCL is released in continuity with the periosteum and synovial attachments to the bone. When this lateral tightness is associated with internal rotational contracture, the popliteus tendon attachment to the femur is also released. The iliotibial band and lateral posterior capsule should not be released in this situation because they provide lateral stability only in extension. The only structures that provide passive stability in flexion are the LCL and the popliteus tendon complex, so knees that are tight laterally in flexion and extension have popliteus tendon or LCL release (or both). Stability is tested after adjusting tibial thickness to restore ligament tightness on the lateral side of the knee. Additional releases are done only as necessary to achieve ligament balance. Any remaining lateral ligament tightness usually occurs in the extended position only, and is addressed by releasing the iliotibial band first, then the lateral posterior capsule, if needed. The iliotibial band is approached subcutaneously and released extrasynovially, leaving its proximal and distal ends attached to the synovial membrane. In knees initially too tight laterally in extension, but not in flexion, the LCL and popliteus tendon are left intact, and the iliotibial band is released. If this does not loosen the knee enough laterally, the lateral posterior capsule is released. The LCL and popliteus tendon rarely, if ever, are released in this type of knee. Finally, the tibial component thickness is adjusted to achieve proper balance between the medial and lateral sides of the knee. Anteroposterior stability and femoral rollback are assessed, and posterior cruciate substitution is done, if necessary, to achieve acceptable posterior stability

Abstract. Optimal acetabular component position in Total Hip Arthroplasty is vital for avoiding complications such as dislocation and impingement, Transverse acetabular ligament (TAL) have been shown to be a reliable landmark to guide optimum acetabular cup position. Reports of iliopsoas impingement caused by acetabular components exist. The Psoas fossa (PF) is not a well-regarded landmark for Component positioning. Our aim was to assess the relationship of the TAL and PF in relation to Acetabular Component positioning. A total of 22 cadavers were implanted on 4 occasions with the an uncemented acetabular component. Measurements were taken between the inner edge of TAL and the base of the acetabular component and the distance between the lower end of the PF and the most medial end of TAL. The distance between the edge of the acetabular component and TAL was a mean of 1.6cm (range 1.4–18cm). The distance between the medial end of TAL and the lowest part of PF was a mean of 1.cm (range 1,3–1.8cm) It was evident that the edge of PF was not aligned with TAL. Optimal acetabular component position is vital to the longevity and outcome following THA. TAL provides a landmark to guide acetabular component position. However we feel the PF is a better landmark to allow appropriate positioning of the acetabular component inside edge of the acetabulum inside the bone without exposure of the component rim and thus preventing iliopsoas impingement at the psoas notch and resultant groin pain

Despite of the high success of TKA, 20% of recipients remain dissatisfied with their surgery. There is an increasing discordance in the literature on what is an optimal goal for component alignment. Furthermore, the unique patient specific anatomical characteristics will also play a role. The dynamic characteristic of a TKR is a product of the complex interaction between a patient's individual anatomical characteristics and the specific alignment of the components in that patient knee joint. These interactions can be better understood with computational models. Our objective was to characterise ligament characteristics by measuring knee joint laxity with functional radiograph and with the aid of a computational model and an optimisation study to estimate the subject specific free length of the ligaments. Pre-operative CT and functional radiographs, varus and valgus stressed X-rays assessing the collateral ligaments, were captured for 10 patients. CT scan was segmented and 3D–2D pose estimation was performed against the radiographs. Patient specific tibio-femoral joint computational model was created. The model was virtually positioned to the functional radiograph positions to simulate the boundary conditions when the knee is stressed. The model was simulated to achieve static equilibrium. Optimisation was done on ligament free length and a scaling coefficient, flexion factor, to consider the ligaments wrapping behaviour. Our findings show the generic values for reference strain differ significantly from reference strains calculated from the optimised ligament parameters, up to 35% as percentage strain. There was also a wide variation in the reference strain values between subjects and ligaments, with a range of 37% strain between subjects. Additionally, the knee laxity recorded clinically shows a large variation between patients and it appears to be divorced from coronal alignment measured in CT. This suggests the ligaments characteristics vary widely between subjects and non-functional imaging is insufficient to determine its characteristics. These large variations necessitate a subject-specific approach when creating knee computational models and functional radiographs may be a viable method to characterise patient specific ligaments

Introduction. Ligament balancing in performing TKA is an upcoming topic to improve the results in TKA. A well balanced knee is working more proper together with the muscular stabilizing structures. Dynamic ligament balancing (DLB)R should give us the opportunity to check the balance of the ligaments at the beginning and the end of the surgery before implanting the definitive prosthesis. It is a platform independent, single-use device, which can be combined with all common types of knee prosthesis. Materials and Methods. DLBR consists of a set of 10 different sizes of baseplates including a feather of 15 to 20N (A). Connected to a tablet all datas can be shown during surgery and stored for patient security. During the surgery after calibrating the tibial cut is performed first, where it should be 90° to the longitudinal axis respecting the right slope. Measurement before femoral cuts are performed and give an information about the joint angle according to the anatomical and load axis. The femoral cuts can be performed with the original cutting block of every set in extension and flexion. After positioning the femoral trial, testing is repeated and should show a balanced situation over all the ROM. The overall period datas were stored and compared to the subjective feeling of the patients. Results. Performing the first 20 patients (DLB) a better balanced situation is visible in all knees respecting the including factors in comparison to the control group (CG). Especially young and active patients demonstrate a huge benefit in coming earlier back to work and sport, elder patients reach independence faster. No extension of the surgical time was seen, respecting the learning curve is a valuable benefit in higher accuracy and precision in TKA. All PROMs show good and excellent results. OKS and AKSS show an average 10% better result after 6 months (AKSS DLB 97/CG 90, OKS DLB 44/ CG 40). The forgotten knee score shows a normal leading according to the short term. Discussion. DLBR is a new concept using single-use devices and is platform independant. Further measurements and comparisons are necessary to value these first excellent results. By the moment the inclusion factors are settled narrow, but the future will show, where the borders of this method will be. Conclusion. Measuring the gap and ligament tension all over the ROM from 0 to 90° continuously gives the possibility to value the accuracy of the procedure together with marking points to compare it to the clinical postoperative result. Matching the procedure shows an increasing satisfaction of the patients due to a better balanced situation. Although there are limiting factors (no severe deformities, muscular deseases, ligament failure) it is a hopeful opportunity to increase the results in TKA in the future