Background. In order to restore the neutral limb alignment in total knee arthroplasty (TKA), surgical procedure usually starts with removing osteophytes in varus osteoarthritic knees. However, there are no reports in the literature regarding the exact influence of osteophyte removal on alignment correction. The purpose of this study was to define the influence of osteophyte removal alone on limb alignment correction in the coronal plane in TKA for varus knee. Methods. Twenty-eight medial osteoarthritic knees with varus malalignment scheduled for TKA were included in this study. After registration of a navigation system, each knee was tested at maximum extension, and at 30, 40 and 60 degrees of flexion before and after osteophyte removal. External loads of 10 N-m valgus torque at each angle and in both states were applied. Subsequently, the widths of the resected osteophytes were measured. Results. The average pre-operative hip-knee-ankle angle was −12.6 degrees. The average width of osteophytes was 7.1 mm in femur and 4.8 mm in tibia, respectively. Angle corrections after osteophyte removal were 2.5 degrees at maximum extension, 2.8 degrees at 30 degrees flexion and 2.5 degrees at 60 degrees flexion; and at all angles, the difference was significant. There was positive correlation between the widths of osteophytes and the degree of angle correction at 30 degrees. Conclusion. Correlation was found at 30 degrees of knee flexion between the widths of osteophytes and the degree of angle correction in the coronal plane in TKA. We found the degree of angle correction per 1mm width of osteophyte removal to be 0.4 degrees

Introduction. For restoration of neutral limb alignment in Total Knee Arthroplasty (TKA), we usually start by removing osteophytes in varus osteoarthritic knees. However, we have found no reports in the literature regarding research on the exact influence of osteophyte removal on angle correction. The purpose of this study was to define the influence of osteophyte removal on limb alignment correction in the coronal plane in TKA. Materials and Methods. Nine patients with varus malalignment that were scheduled for TKA were included in this study. Only patients with degenerative osteoarthritis were considered. After registration of a navigation system, each knee was tested at maximum extension, and 30 and 60 degrees of flexion before and after osteophyte removal. The same examiner applied all external loads of 10 N-m valgus torque at each angle and in both states. Subsequently, the widths of the osteophytes were measured. All data were analyzed statistically using paired t-test and correlation coefficient. A significant difference was determined to be present for P < .05. Results. The average pre-operative femoral tibial angle (FTA) was 185.1 degrees. The average width of femoral osteophytes was 6.4±2.36 mm, and the average width of tibial osteophytes was 3.4±1.16 mm. There were no significant differences in maximum extension angles between before and after osteophyte removal. The corrected angles after osteophyte removal were 1.4±1.31 degrees at maximum extension, 1.8±1.33 degrees at 30 degrees flexion and 1.7±1.15 degrees at 60 degrees flexion; and at all angles, the difference was significant. There was positive correlation between the widths of femoral osteophytes and the degree of angle correction at 30 degrees (r=0.829). Conclusion. At 30 degrees of knee flexion, there was a correlation between the widths of osteophytes and the degree of angle correction. In this study, the degree of angle correction for 1mm width of osteophyte removal was 0.3 degrees

Aims. The aims of this prospective study were to determine the effect of osteophyte excision on deformity correction and soft- tissue gap balance in varus knees undergoing total knee arthroplasty (TKA). Patients and Methods. Limb deformity in coronal (varus) and sagittal (flexion) planes, medial and lateral gap distances in maximum knee extension and 90° knee flexion and maximum knee flexion were recorded before and after excision of medial femoral and tibial osteophytes using computer navigation in 164 patients who underwent 221 computer-assisted, cemented, cruciate- substituting TKAs. Results. Mean varus and flexion deformities of 4.5°±3° (0.5° to 30° varus) and 4.9°±5.9° (−15° hyperextension to 30° flexion) reduced significantly (p<0.0001) to mean varus deformity of 1°±2.3° and mean flexion deformity of 2.7°±4.2° after excision of medial femoral and tibial osteophytes. The mean medio-lateral (ML) soft-tissue gap difference in maximum knee extension and 90°knee flexion of 2.7±3.6mm and 0.7±2.6mm reduced significantly (p<0.0001) to mean ML soft-tissue gap difference of 0.7±2.5mm in maximum knee extension and 0.1±1.9mm in 90°knee flexion. The mean maximum knee flexion (122.8°±8.4°) increased significantly to mean maximum knee flexion of (125°±8°). Conclusion. Excision of medial femoral and tibial osteophytes during TKA in varus knees significantly improves varus and flexion deformities, mediolateral soft-tissue gap imbalance in maximum extension and in 90°knee flexion and maximum knee flexion. Clinical Relevance. Excision of medial femoral and tibial osteophytes can be a useful, initial step towards achieving deformity correction and gap balance without having to resort to soft-tissue release during TKA in varus knees

Osteophytes are bony spurs on normal bone that develop as an adaptive reparative process due to excessive stress at/near a joint. As osteophytes develop from normal bone, they are not always well depicted in common imaging techniques (e.g. CT, MRI). This creates a challenge for preoperative planning and image-guided surgical methods that are commonly incorporated in the clinical routine of orthopaedic surgery. The study examined the accuracy of osteophyte detection in clinical CT and MRI scans of varying types of joints. The investigation was performed on fresh-frozen ex-vivo human resected joints identified as having a high potential for presentation of osteophytes. The specimens underwent varying imaging protocols for CT scanning and clinical protocols for MRI. After dissection of the joint, the specimens were subjected to structured 3D light scanning to establish a reference model of the anatomy. Scans from the imaging protocols were segmented and their 3D models were co-registered to the light scanner models. The quality of the osteophyte images were evaluated by determining the Root Mean Square (RMS) error between the segmented osteophyte models and the light scan model. The mean RMS errors for CT and MRI scanning were 1.169mm and 1.419mm, respectively. Comparing the different CT parameters, significance was achieved with scanning at 120kVp and 1.25mm slice thickness to depict osteophytes; significance was also apparent at a lower voltage (100kVp). Preliminary results demonstrate that osteophyte detection may be dependent on the degree of calcification of the osteophyte. They also illustrate that while some imaging parameters were more favourable than others, a more accurate osteophyte depiction may result from the combination of both MRI and CT scanning

Gap planning in total knee arthroplasty (TKA) navigation is critically concerned. Osteophyte is one of the contributing factors for gap balancing in TKA. The osteophyte is normally removed before gap planning step. However, the posterior condylar osteophyte of femur is sometimes removed during the flexion gap preparation or may not be removed at all depends on individual case. This study attempts to investigate on how posterior condylar osteophyte affects on gap balancing and limb alignment during operation. The study was conducted on 35 varus osteoarthritis knees with posterior condylar osteophyte and undergone on TKA navigation. All knees were measured by CT scan for the size of posterior condylar osteophyte according to its width. Extension gap, flexion gap width, and limb alignment were measured by using the tension device with distraction force of 98 N on both medial and lateral sides under computer assisted surgery. The measuring of extension gap, flexion gap width, and limb alignment was undertaken before and after the posterior condylar osteophyte removal. This study reveals that the mean of the size of posterior condylar osteophyte after removal is 8.96 mm. The posterior condylar osteophyte has an effect on the increasing of medial extension gap and lateral extension in average 0.74 ± 0.72 mm. and 0.42 ± 0.67 mm. respectively. It also increases 0.71 ± 1.00 mm. in medial flexion gap and 0.97 ± 1.47 mm. in lateral flexion gap. After the posterior condylar osteophyte removal the mean of varus deformity is decreased 0.90° ± 1.14 ° while the mean of extension angle of sagittal limb alignment is increased 1.61°±1.69°. There is also a significant relationship between the size of posterior condylar osteophyte and the increasing of lateral flexion gap and also with the varus deformity decreasing. If the size of posterior condylar osteophyte is increased 10 mm. the lateral flexion gap will be increased 1.15 mm. and varus deformity will be decreased 0.75 degree

Abstract. Introduction. Recurrent groin pain following periacetabular osteotomy (PAO) is a challenging problem. The purpose of our study was to evaluate the position and dynamics of the psoas tendon as a potential cause for recurrent groin pain following PAO. Methods. Patients with recurrent groin pain following PAO were identified from a single surgeon series. A total of 13 patients with 18 hips (4.7%) out of a 386 PAO, had recurrent groin pain. Muscle path of the psoas tendon was accurately represented using 3D models from CT data were created with Mimics software. A validated discrete element model using rigid body springs was used to predict psoas tendon movement during hip circumduction and walking. Results. Five out of the 18 hips did not show any malformations at the osteotomy site. Thirteen hips (72%) showed malformation secondary to callus at the superior pubic ramus. These were classified into: osteophytes at the osteotomy site, hypertrophic callus or non-union and malunion at the osteotomy. Mean minimal distance of the psoas tendon to osteophytes was found to be 6.24 mm (n=6) and to the osteotomy site was 14.18 mm (n=18). Conclusions. Recurrent groin pain after PAO needs a thorough assessment. One need to have a high suspicion of psoas issues as a cause. 3D CT scan may be necessary to identify causes related to healing of the pubic osteotomy. Dynamic ultrasound of the psoas psoas tendon may help in evaluating for psoas impingement as a cause of recurrent groin pain in these cases

Introduction. Robotic TKA allows for quantifiable precision performing bone resections for implant realignment within acceptable final component and limb alignments. One of the early steps in this robotic technique is after initial exposure and removal of medial and lateral osteophytes, a “pose-capture” is performed with varus and valgus stress applied to the knee in near full extension and 90° of flexion to assess gaps. Component alignment adjustments can be made on the preoperative plan to balance the gaps. At this point in the procedure any posterior osteophytes will still be present, which could after removal change the flexion and extension gaps by 1–3mm. This must be taken into consideration, or changes in component alignment could result in over-correction of gaps can occur. Objective. The purpose of this study was to identify what effect the posterior osteophyte's size and location and their removal had on gap measurements between pose-capture and after bone cuts are made and gaps assessed during implant trialing. Methods. This was a retrospective, single center cohort study comparing 100 robotic-assisted TKAs. Preoperative computer tomography was assessed for the presence, size and location of posterior osteophytes. Robotic-assessed gaps at pose capture and trialing were collected. Paired t-tests, independent t-tests and Pearson's correlation were used to examine this relationship. Results. Posterior osteophytes were present in 87% of cases with 59.3% isolated to the posterior medial femoral condyle. In the sagittal plane, posterior medial femoral condyle (pMFC), posterior lateral femoral condyle (pLFC) and posterior tibial (pT) osteophytes measured 6.75 ± 2.7mm, 5.77 ± 2.8mm, and 6.52 ± 3.14mm respectively. There was a significant increase in medial (17.4 ± 2.7mm vs 19.7 ± 2.2mm, p<0.01) and lateral (19.2 ± 2.2mm vs 20.5 ± 1.9mm, p<0.01) extension gaps from pose-capture to trialing. There was no difference in the delta of medial extension gaps from pose-change to trialing for knees with pMFC osteophytes > or < 5mm (2.1 ± 2.3 mm vs 2.4 ± 2.1mm, p=0.56). Similarly, there was no difference in the change in lateral extension gaps from pose-capture to trialing for knees with lateral posterior osteophytes > or < 5mm (1.2 ± 2.0mm vs 1.73 ± 1.53mm, p = 0.37). There was no statistically significant correlation between medial or lateral osteophyte size and change in medial (r=0.12, p=0.27) or lateral (r=0.11, p=0.36) extension gaps respectively. Conclusion. While there is a significant change in robotically assessed gaps at pose-capture and trialing, this change is small, our study findings are not able to substantiate that it is solely due to the presence, size or location of posterior osteophytes. A post-hoc power analysis indicates that, in order to detect a difference in gap between pose-capture and trialing of 1mm, over 75 knees with and without posterior osteophytes would be needed

Background. Osteophytes in the posterior compartment of the knee pose a challenge in achieving soft tissue balance during total knee arthroplasty (TKA). Previous investigations have demonstrated the importance of various factors involved in obtaining flexion and extension gap balance, including the precision of femoral and tibial bone cuts as well as tensioning of the supporting pericapsular soft tissue structures (ligaments, capsule, etc.). However, the role of posterior compartment osteophytes has not been well studied. We hypothesize that space-occupying posterior structures affect soft tissue balance, especially in lesser degrees of flexion, in a cadaveric TKA model. Methods. Five cadaveric limbs were acquired. CT scans were obtained of each specimen to define the osseous contours. 3D printed specimen-specific synthetic osteophytes were fabricated in two sizes (10mm and 15mm). Posterior-stabilized TKAs were performed. Medial and lateral contact forces were measured during a passive range of motion using OrthoSensor ® (Dania Beach, FL) technology. For each specimen, trials were completed without osteophytes, and with 10mm and 15mm osteophytes applied to the posterior medial femur, with iterations at 0°, 10°, 30°, 45°, 60°, and 90° of flexion. These were recorded across each specimen in each condition for three trials. Tukey post hoc tests were used with a repeated measures ANOVA for statistical data analysis. Results. The presence of posterior medial osteophytes increased asymmetric loading from 0°– 45° of flexion. The 25–75% bounds of variability in the contact force was less than 3.5lbs. Conclusions. In this cadaveric TKA model, posterior femoral osteophytes caused an asymmetric increase in contact forces from full extension continuing into mid-flexion. To avoid unnecessary soft tissue releases, we recommend early removal of posterior femoral osteophytes prior to performing ligament releases to obtain desired soft tissue balance during TKA

Introduction. In total knee arthroplasty (TKA), component realignment with bone-based surgical correction (BBSC) can provide soft tissue balance and avoid the unpredictability of soft tissue releases (STR) and potential for more post-operative pain. Robotic-assisted TKA enhances the ability to accurately control bone resection and implant position. The purpose of this study was to identify preoperative and intraoperative predictors for soft tissue release where maximum use of component realignment was desired. Methods. This was a retrospective, single center study comparing 125 robotic-assisted TKAs quantitatively balanced using load-sensing tibial trial components with BBSC and/or STR. A surgical algorithm favoring BBSC with a desired final mechanical alignment of between 3° varus and 2° valgus was utilized. Component realignment adjustments were made during preoperative planning, after varus/valgus stress gaps were assessed after removal of medial and lateral osteophytes (pose capture), and after trialing. STR was performed when a BBSC would not result in knee balance within acceptable alignment parameters. The predictability for STR was assessed at four steps of the procedure: Preoperatively with radiographic analysis, and after assessing static alignment after medial and lateral osteophyte removal, pose capture, and trialing. Cutoff values predictive of release were obtained using receiver operative curve analysis. Results. STR was necessary in 43.5% of cases with medial collateral ligament (MCL) release being the most common. On preoperative radiographs, a medial tibiofemoral angle (mTFA) ≤177° predicted MCL release (AUC = 0.76. p< 0.01) while an mTFA ≥188° predicted ITB release (AUC = 0.79, p <0.01). Intraoperatively after removal of osteophytes, a robotically assessed mechanical alignment (MA) ≥8° varus predicted MCL release (AUC = 0.84. p< 0.01) while a MA ≥2° valgus (AUC = 0.89, p< 0.01) predicted ITB release. During pose-capture, in medially tight knees, an extension gap imbalance ≥2.5mm (AUC = 0.82, p <0.01) and a flexion gap imbalance ≥2.0mm (AUC = 0.78, p <0.01) predicted MCL release while in laterally tight knees, any extension or flexion gap imbalance >0 mm predicted ITB release (AUC = 0.84, p <0.01 and AUC = 0.82, p <0.01 respectively). During trialing, in medially tight knees, a medial>lateral extension load imbalance ≥18 PSI (AUC = 0.84. p< 0.01) and a flexion load imbalance ≥ 35 PSI (AUC = 0.83, p< 0.01) predicted MCL release while, in laterally tight knees, a lateral>medial extension load imbalance ≥3 PSI (AUC = 0.97, p< 0.01) or flexion load imbalance ≥ 9.5 PSI (AUC = 0.86, p< 0.01) predicted ITB release. Of all identified predictors, load imbalance at trialing had the greatest positive predictive value for STR. Conclusion. There are limitations to the extent that TKA imbalance that can be corrected with BBSC alone if one has a range of acceptable alignment parameters. The ability to predict STR improves from pose-capture to trialing stages during detection of load imbalance. Perhaps this may be due to posterior osteophytes that are still present at pose capture. Further investigation of the relationship between the presence, location and size of posterior osteophytes and need for STR during TKA is necessary

Osteoarthritis (OA) is a disease of the synovial joint with synovial inflammation, capsular contracture, articular cartilage degradation, subchondral sclerosis and osteophyte formation contributing to pain and disability. Transcriptomic datasets have identified genetic loci in hip and knee OA demonstrating joint specificity. A limited number of studies have directly investigated transcriptional changes in shoulder OA. Further, gene expression patterns of periarticular tissues in OA have not been thoroughly investigated. This prospective case control series details transcriptomic expression of shoulder OA by analysing periarticular tissues in patients undergoing shoulder replacement for OA as correlated with a validated patient reported outcome measure of shoulder function, an increasing (clinically worsening) QuickDASH score. We then compared transcriptomic expression profiles in capsular tissue biopsies from the OA group (N=6) as compared to patients undergoing shoulder stabilisation for recurrent instability (the control group, N=26). Results indicated that top ranked genes associated with increasing QuickDASH score across all tissues involved inflammation and response to stress, namely interleukins, chemokines, complement components, nuclear response factors and immediate early response genes. Some of these genes were upregulated, and some downregulated, suggestive of a state of flux between inflammatory and anti-inflammatory signalling pathways. We have also described gene expression pathways in shoulder OA not previously identified in hip and knee OA, as well as novel genes involved in shoulder OA

Low back pain is the single most common cause for disability in individuals aged 45 years or younger, it carries tremendous weight in socioeconomic considerations. Degenerative aging of the structural components of the spine can be associated with genetic aspects, lifetime of tissue exposure to mechanical stress & loads and environmental factors. Mechanical consequences of the disc degenerative include loss of disc height, segment instability and increase the load on facets joints. All these can lead to degenerative changes and osteophytes that can narrow the spinal canal. Surgery is indicated in patients with spinal stenosis who have intractable pain, altered quality of life, substantially diminished functional capacity, failed non-surgical treatment and are not candidates for non-surgical treatment. The aim was to determine the reasons for refusal of surgery in patients with established degenerative lumber spine pathology eligible for surgery. All patients meeting the study criteria, patients older than 18 years, patients with both clinical and radiological established symptomatic degenerative lumbar spine pathology and patients eligible for surgery but refusing it were recruited. Questionnaire used to investigate reasons why they are refusing surgery. Results 59 were recruited, fifty-one (86.4 %) females and eight (13.6 %) males. Twenty (33.8 %) were between the age of 51 and 60 years, followed by nineteen (32.2 %) between 61 and 70 years, and fourteen (23.7 %) between 71 and 80 years. 43 (72 %) patients had lumber spondylosis complicated by lumber spine stenosis, followed by nine (15.2 %) with lumbar spine spondylolisthesis and four (6.7 %) had adjacent level disease. 28 (47.4 %) were scared of surgery, fifteen (25.4 %) claimed that they are too old for surgery and nine (15.2 %) were not ready. Findings from this study outlined that patients lack information about the spinal surgery. Patients education about spine surgery is needed

Knowledge of the premorbid glenoid shape and the morphological changes the bone undergoes in patients with glenohumeral arthritis can improve surgical outcomes in total and reverse shoulder arthroplasty. Several studies have previously used scapular statistical shape models (SSMs) to predict premorbid glenoid shape and evaluate glenoid erosion properties. However, current literature suggests no studies have used scapular SSMs to examine the changes in glenoid surface area in patients with glenohumeral arthritis. Therefore, the purpose of this study was to compare the glenoid articular surface area between pathologic glenoid cavities from patients with glenohumeral arthritis and their predicted premorbid shape using a scapular SSM. Furthermore, this study compared pathologic glenoid surface area with that from virtually eroded glenoid models created without influence from internal bone remodelling activity and osteophyte formation. It was hypothesized that the pathologic glenoid cavities would exhibit the greatest glenoid surface area despite the eroded nature of the glenoid and the medialization, which in a vault shape, should logically result in less surface area. Computer tomography (CT) scans from 20 patients exhibiting type A2 glenoid erosion according to the Walch classification [Walch et al., 1999] were obtained. A scapular SSM was used to predict the premorbid glenoid shape for each scapula. The scapula and humerus from each patient were automatically segmented and exported as 3D object files along with the scapular SSM from a pre-operative planning software. Each scapula and a copy of its corresponding SSM were aligned using the coracoid, lateral edge of the acromion, inferior glenoid tubercule, scapular notch, and the trigonum spinae. Points were then digitized on both the pathologic humeral and glenoid surfaces and were used in an iterative closest point (ICP) algorithm in MATLAB (MathWorks, Natick, MA, USA) to align the humerus with the glenoid surface. A Boolean subtraction was then performed between the scapular SSM and the humerus to create a virtual erosion in the scapular SSM that matched the erosion orientation of the pathologic glenoid. This led to the development of three distinct glenoid models for each patient: premorbid, pathologic, and virtually eroded (Fig. 1). The glenoid surface area from each model was then determined using 3-Matic (Materialise, Leuven, Belgium). Figure 1. (A) Premorbid glenoid model, (B) pathologic glenoid model, and (C) virtually eroded glenoid model. The average glenoid surface area for the pathologic scapular models was 70% greater compared to the premorbid glenoid models (P < 0 .001). Furthermore, the surface area of the virtual glenoid erosions was 6.4% lower on average compared to the premorbid glenoid surface area (P=0.361). The larger surface area values observed in the pathologic glenoid cavities suggests that sufficient bone remodelling exists at the periphery of the glenoid bone in patients exhibiting A2 type glenohumeral arthritis. This is further supported by the large difference in glenoid surface area between the pathologic and virtually eroded glenoid cavities as the virtually eroded models only considered humeral anatomy when creating the erosion. For any figures or tables, please contact the authors directly

When dealing with a flexion contracture, a surgeon first should consider all potential causes, specifically ligament contracture and osteophytes. Then consider the size of the femoral component and its position proximal to distal and also the posterior slope of the tibial component. Most knee flexion contractures are caused by osteophytes and tight ligaments, and once these problems are corrected, no further work needs to be done on the knee. So when the bone surface cuts are made, in general, little compensation is done in terms of positioning the femoral component proximal or distal, or in terms of sloping the tibial component (beyond the normal 3–4 degrees posterior slope), before the ligaments or osteophytes are managed. If the deep medial collateral ligament (MCL) and posterior portion of the superficial MCL are tight, a flexion contracture will almost always be present after the bone surfaces are finished. Once this is corrected with proper ligament releases and removal of osteophytes, then ligament balance and flexion contracture should be reassessed. In the very few cases that still have a flexion contracture, posterior capsule release should be done. Once this is finished, releasing the capsule from both the femur and the medial aspect of the tibia, then ligament balance is reassessed again. If flexion contracture still remains (<10% of cases), then the distal surface of the femur is resected another 4–6 mm, trial components are inserted, and flexion contracture is evaluated. If more bony resection is needed, then changing tibial slope from 4 degrees posterior slope to 0 degrees slope is another step that can be done to remove bone from extension space of the knee finally to achieve full extension. Virtually all flexion contractures, except those with severe contracture resulting from hamstring tightness, can be corrected with this method. In the valgus knee with flexion contracture, similar management is used. Knees that will not extend and remain tight on the lateral side usually are corrected with release of the posterior capsule and posterior portion of the iliotibial band. Just as on the lateral side, bone resection from the distal femur can be performed as a final effort to achieve full extension of the knee. It is worth reiterating that almost all flexion contractures are caused by ligament imbalance, and that over-resection of the distal femur at the start of these cases can easily result in hyperextension that is difficult to manage once ligaments have been balanced

Introduction. Most of the algorithm available today to balance varus knee is based on a surgeon's hands-on experience without full understanding of pathological anatomy of varus knee. The high-resolution MRI allows us to recognize the anatomical details of the posteromedial corner and the changes of the soft tissue associated with the osteoarthritis and varus deformity. We have in this study, reviewed 60 cases of severe varus knee scheduled for TKR and compared it to normal MRI and those MRI were evaluated and read by a musculoskeletal radiologist. We have documented clearly the changes that happens in soft tissue, leading to tight medial compartment. We will also show multiple short intra-operative video confirming that MRI findings. Material & method. We have retrospectively reviewed the MRI on 60 patients with advanced osteoarthritis varus knee. We also reviewed 20 MRI for a normal knee matched for age. We evaluated the posteromedial complex and MCL in sagittal PD-weighted VISTA to check the alignment of the MCL and posteromedial complex and the associate MCL bowing and deformity that could happen in osteoarthritis knee. We have measured the thickness of the posteromedial complex and the posterior medial bowing of the superficial MCL and the involvement of the posterior oblique ligament in those patients. To measure the posterior bowing of the MCL, a line was drawn through the posterior aspect of both menisci and we measured the distance between the posterior edge of MCL to that line in actual image. To measure the thickness of the posteromedial complex, we measured it at two areas in the posterior medial corner posteriorly at the level of the medial meniscus. Measuring the medial bowing of the MCL was done by a line drawn through the medial edge of the femoral condyle and the tibial condyle at the level of the medial meniscus to the inner aspect of the MCL. The normal distance between the posterior aspects of the MCL to the posterior meniscus line was approximately measured 2 cm. in average. Results. We were able to recognize and measure the medial deviation of MCL in all arthritic knees due to the deformity and the effect of the medial margin osteophyte and medial extrusion of the meniscus. Thickening of posteromedial complex was recognized in the majority of the cases with prominent thickening seen in 50/60 knees with average thickness measuring approximately 1.2 cm due to the synovial thickening, adhesions, granulation tissue, degenerated medial meniscus, and involvement of the posterior oblique ligament and the capsular branch of the semimembranosus tendon, as well as the oblique popliteal ligament. The involvement of posterior oblique ligament were seen in majority of the cases. In 55 cases we have showed a heterogeneous appearance of the ligament and loss of normal signal within the postero medial complex and we have documented that the oblique ligament will cause the posterior bowing of the MCL. The medial bowing of the MCL is also correlated to the severity of the varus deformity with an average distance to the normal medial line of the medial meniscus measuring approximately 1.1 cm. Discussion. Our study shows that the changes affecting the superficial MCL is likely to be secondary to the obvious changes involving the posteromedial complex and to the marginal osteophyte as well as the extrusion of the medial meniscus. Also, we have confirmed that there are deforming structures such as the oblique ligament with adhesion and thickening with all the posterior medial complex. Those changes clearly caused the posterior bowing to the superficial MCL without an actual shortening of the ligament. The scarring tissue in the posteromedial corner and the adhesion is acting as a soft phyte tensioning and deforming the ligament and the posterior capsule. The oblique ligament act as a deforming forces forcing the superficial MCL to bow posteriorly. The lengths of the superficial MCL stayed the same. Conclusion. The conventional wisdom of releasing the distal attachment of the superficial medial MCL to balance knee has to be a challenge based on our MRI finding. Releasing the superficial MCL can sometimes lead to a major instability of the knee requiring a more constrained implant. Our MRI assessment clearly showed that the Superficial MCL is deformed because of posterior bowing and medial bowing and considerable thickening of the posteromedial corner, as well as the accompanying osteophyte. We believe that clearing the superficial MCL and excising those thickened scar tissue in the posterior medial corner will enable us to balance the knee without creating instability Conclusion: The conventional wisdom of releasing the distal attachment of the superficial medial MCL to balance knee has to be a challenge based on our MRI finding. Releasing the superficial MCL can sometimes lead to a major instability of the knee requiring a more constrained implant. Our MRI assessment clearly showed that the Superficial MCL is deformed because of posterior bowing and medial bowing and considerable thickening of the posteromedial corner, as well as the accompanying osteophyte. We believe that clearing the superficial MCL and excising those thickened scar tissue in the posterior medial corner will enable us to balance the knee without creating instability

Introduction. Since 1989 we have been using custom lateral-flare stems. Using this stem, its lateral flare can produce high proximal fit and less fit in distal part. Applying this automatic designing software to the average femoral geometries, we can make off the shelf high proximal fit stem (Revelation ®). Putting the off the shelf stem, the original center of the femoral heads were well reproduced. But in DDH cases, severe deformities around hip sometimes make complicated difficulty for better functional reconstruction. They are high hip center such as Crowe II-IV, shortening of the femoral neck, high anteversion etc. DDH cases are well known to have higher anteversion than non DDH cases. There would be no definite explanations for it. The high anteversion would not always be harmful for the preoperative patients. But in some cases, osteophytes are observed at posterior side of the femoral head which make another sphere with different centre. We can guess that the patient's biomechanics had not been matched with the original anteversion. Then posterior osteophytes can correct inappropriate anteversion (self-reduction.) (Fig.1) In those patients, reduction of the anteversion by putting stems twisted into the canal or using modular stems are sometimes done by the surgeons' decision. Younger DDH cases can also be treated with THA, because of the complicated deformities or biomechanical disorders. Short stems are expected to reduce operative invasion and stress shielding then can reserve bone quality and quantity. From these point of view to improve the understanding of the characteristics of the DDH anteversion, and design a DDH oriented short stem could be one of good solution for those cases. Method. For the better understanding of the high anteversion 57 femora (mean anteversion: 34.4 deg.) were analyzed slice by slice. The direction of femoral head centre, lesser trochanter (LTR), linea aspera (aspera) just below LTR, aspera in the middle of the femur and aspera between the last 2 sections. All of the directions were assessed from PC line. To clarify the meaning of the head osteophytes, 35 operated cases were analyzed the extent of the head osteophytes. According to the results, a DDH oriented short stem was designed. Results. Even with the different anteversion, femoral head centres and LTRs were located within limited angle (51.4 +/−7.9 deg.) But aspera just below the LTR had no relation to the LTR direction, but always kept within limited angle (102.0 +/− 4.5) to the PC line. This means that DDH cases have proximal femurs of normal shape. But they are only twisted around the level just below the LTR. From this result, stems for DDH cases can have the same shape with normal stem inside the canal. The posterior osteophytes had reduced 4.6+/− 3.0 degree in average independently to the extent of anteversion. There was no tendency that higher anteversion cases have higher self-reduction angle. the stems were give the same shape inside the canal with stems for non DDH cases but its femoral head center was located with 5 degrees less anteversion

INTRODUCION. Appropriate soft tissue balance is an important factor for postoperative function and long survival of total knee arthroplasty(TKA). Soft tissue balance is affected by ligament release, osteophyte removal, order of soft tissue release, cutting angle of tibial surface and rotational alignment of femoral components. The purpose of this study is to know the characteristics of soft tissue balance in ACL deficient osteoarthritis(OA) knee and warning points during procedures for TKA. METHODS. We evaluated 139 knees, underwent TKA (NexGen LPS-Flex, fixed surface, Zimmer) by one surgeon (S.A.) for OA. All procedures were performed through a medial parapatellar approach. There were 49 ACL deficient knees. A balanced gap technique was used in 26 ACL deficient knees, and anatomical measured technique based on pre-operative CT was used in 23 ACL deficient knees. To compare flexion-extension gaps and medial- lateral balance during operations between the two techniques, we measured each using an original two paddles tensor (figure 1) at 20lb, 30lb and 40lb, for each knee at a 0 degree extension and 90 degree flexion. We measured bone gaps after removal of all osteophytes and cutting of the tibial surface, then we measured component gaps after insertion of femoral components. Statistical analysis was performed by t-test with significant difference defined as P<0.05. RESULTS. (1) There were 90 ACL remaining knees and 49 deficient knees. Each group's preoperative FTA was 184±4.4 degrees, 187±6.3 degrees, postoperative FTA was 174±2.7 degrees, 173±3.1 degrees, preoperative knee extension was −12.8±7.5 degrees, −14.5.±3.1 degrees, flexion was 122.4±13.7 degrees, 110.7±20.2 degrees, post-operative β angle was, 88.1±2.5 degrees, 88.5±2.5 degrees. Comparing bone gap, medial gap and lateral-medial gap at a 30lb flexion were significantly different(P<0.05). (2) Comparing component gaps using modified gap techniques (group G) and anatomical techniques (group A) in ACL deficient knees, extension of medial and lateral gaps at 30lb and 40 lb in anatomical technique was bigger. The lateral-medial gap at 30lb was bigger in anatomical techniques. (P<0.05). DISCUSSION. The present results showed that ACL deficient OA knee were looser at medial side compared with ACL remaining OA knees. It indicates that we performed medial rerelease carefully in ACL deficient TKA. When we used gap techniques, medial loosening caused malposition of femoral components, and when we used anatomical techniques, extension gap was bigger than using gap techniques because generally smaller femoral components were chosen. It is reported that lateral gaps are bigger in severe varus deformity OA than slightly deformed OA knees and the soft tissue on the medial side is not shorter. It is also reported the correlation of lateral thrust with ACL deficiency and the progression OA, and when OA is developed, lateral side becomes loose. Our study indicated that ACL deficient OA knee progress rotational instability, in addition to antero-posterior instability, and subsequent medial loosening and development of medial osteophyte. Medial preserving gap technique is recommended

Introduction. Instability continues to be the number one reason for revision in primary total hip arthroplasty (THA). Commonly, impingement precedes dislocation, inducing a levering out the prosthetic head from the liner. Impingement can be prosthetic, bony or soft tissue, depending on component positioning and anatomy. The aim of this virtual study was to investigate whether bony or prosthetic impingement occurred first in well positioned THAs, with the hip placed in deep flexion and hyperextension. Methods. Twenty-three patients requiring THA were planned for a TriFit/Trinity ceramic-on-poly cementless construct using the OPS. TM. dynamic planning software (Corin, UK). The cups were sized to best fit the anatomy, medialised to sit on the acetabular fossa and orientated at 45° inclination and 25° anteversion when standing. Femoral components and head lengths were then positioned to reproduce the native anteversion and match the contralateral leg length and offset. The planned constructs were flexed and internally rotated until anterior impingement occurred in deep flexion [Fig. 1]. The type (bony or prosthetic), and location, of impingement was then recorded. Similarly, the hips were extended and externally rotated until posterior impingement occurred, and the type and location of impingement recorded [Fig. 2]. Patients with minimal pre-operative osteophyte were selected as a best-case scenario for bony impingement. Results. 6/23 (26%) patients were planned with only a 32mm articulation (<50mm cup size), with the remaining 17 patients all planned with both 32mm and 36mm articulations (≥50mm cup size). Anterior impingement was 26% prosthetic and 74% bony with the 32mm articulations, and 100% bony with the 36mm articulations. Bony impingement in deep flexion was exclusively anterior neck on anterior inferior iliac spine. Posterior impingement was 57% prosthetic and 43% bony with the 32mm articulations, and 41% prosthetic and 59% bony with the 36mm articulations. Bony impingement in hyperextension was exclusively lesser trochanter (LT) on ischium. Of the patients planned with both 32mm and 36mm articulations, there was a 14% increase in prosthetic impingement when a 32mm head was planned (35% and 21% respectively). Discussion. Impingement in THA usually precedes dislocation and should be avoided with appropriate component positioning. We found that in hyperextension, prosthetic and bony impingement were equally common. In deep flexion, impingement was almost exclusively bony. Further studies should investigate the effects of stem version, cup orientation, liner design, cup depth, native offset and retained osteophytes on the type of impingement in THA. For any figures or tables, please contact the authors directly

Multiple studies have shown that the symptomatology of knee osteoarthritis weakly correlate to radiographic severity of disease. Current literature however does not have much in the way of comparing functional outcomes of those with OA knees with radiographic severity. Our objective was to compare radiographic measurements of OA knees with self-reported functional outcomes and determine if radiographic severity of OA knees correlated with loss of functional ability. A retrospective review of prospectively collected registry data of 305 patients with osteoarthritis of the knee was collected. The patient's x-rays were reviewed, and radiographic measurements were taken to include medial, lateral and patellofemoral joint space distance measured in millimetres. The Kellgren and Lawrence, and Ahlback classifications of radiographic knee OA were computed. These were correlated with severity of functional limitations was measured using the SF36, Knee society score (KSS) and Oxford knee scores. Statistical analysis were conducted with SPSS V22.0 statistical software. Demographic characteristics and functional assessments were analysed using one way ANOVA test. Post-hoc test using Tukey HSD and effect size (partial-eta squared η. 2. ) was performed if one-way ANOVA was found to be statistically significant. A p-value of 0.05 or less was considered statistically significant. Pre-operative patient demographics are shown in table 1. Patients in with Grade 2 osteoarthritis were significantly younger than Grade 4 patients (post-hoc p=0.003). There were no statistically significant differences in age between the other Grades, and there were no differences in BMI or gender or operative site between all grades. There were significant differences in KSS Function scores between Grade 2 and Grade 3 patients (post-hoc p=0.017) and Grade 2 and 4 patients (post-hoc p < 0 .001). Statistically significant differences were also found between Grade 1 and Grade 4 patients for the KSS Knee score (post-hoc p=0.016). There were significant differences in Oxford knee score (post-hoc p=0.026) and SF- Physical Function (post-hoc p < 0 .001) between Grade 2 and Grade 4 patients too. The effect size η. 2. for KSS Function, KSS Knee and Oxford knee score was 0.05, 0.06 and 0.33 respectively. When comparing the loss of joint space with the functional scores, there were no statistically significant correlations. Our study show that the radiological severity of knee osteoarthritis based on the two scoring methods was able to correlate with worsening functional scores. Most notably, the differences in KSS function scores correlated strongly between Grade 2 and Grade 3 patients. Of note, there was no correlation between the loss of joint space and the severity of functional limitations across any of the scoring systems. Our study showed that although both the Kellgren and Lawrence and Ahlback radiological grading of Osteoarthritis were able to correlate with worsening functional scores, this was not due to loss of joint space alone and further studies need to be conducted on the other contributors to the scoring system such as osteophytes and subchondral sclerosis. Our study show that the radiological severity of knee osteoarthritis based on the two scoring methods was able to correlate with worsening functional scores. Most notably, the differences in KSS function scores correlated strongly between Grade 2 and Grade 3 patients. Of note, there was no correlation between the loss of joint space and the severity of functional limitations across any of the scoring systems. Our study showed that although both the Kellgren and Lawrence and Ahlback radiological grading of Osteoarthritis were able to correlate with worsening functional scores, this was not due to loss of joint space alone and further studies need to be conducted on the other contributors to the scoring system such as osteophytes and subchondral sclerosis. For any figures or tables, please contact authors directly

INTRODUCTION. In total hip arthroplasty, preoperative planning is almost indispensable. Moreover, 3-dimensional preoperative planning became popular recently. Anteversion management is one of the most important factors in preoperative planning to prevent dislocation and to obtain better function. In arthritic hip patients osteophytes are often seen on both femoral head and acetabulum. Especially on femoral head, osteophytes are often seen at posterior side and its surface creates smooth round contour that assumes new joint surface. (Fig. 1). We can imagine new femoral head center tracing that new joint surface. OBJECTIVES. In the present study, the posterior osteophytes are compared in osteoarthritic patients and other patients. MATERIALS & METHODS. Anteversion and new anteversion which was reduced by osteophyte formation were assessed in 28 hip CAT scans, (22 arthritic hips, 6 avascular necrotic hips). RESULTS. Only in arthritic patients, osteophytes on posterior side were observed. The anteversion was 33.7+/− 13.0 degree in arthritic patients, which was reduce to 29.7+/−13.1 degree. The mean difference was 4.0+/−4.7 degree reduction. In AVN patients the mean anteversion was 21.4 +/− 9.40 in AVN patients. No reduction was observed in AVN patients. DISCUSSION. Osteophytes are often created to make the biomechanical situation better. This phenomenon is possiblly explained that those posterior osteophytes have been formed for proper reduction of excessive anteversion

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