Aims. Global literature suggests that female surgical trainees have lower rates of independent operating (operative autonomy) than their male counterparts. The objective of this study was to identify any association between gender and lead/independent operating in speciality orthopaedic trainees within the UK national training programme. Methods. This was a retrospective case-control study using electronic surgical logbook data from 2009 to 2021 for 274 UK orthopaedic trainees. Total operative numbers and level of supervision were compared between male and female trainees, with correction for less than full-time training (LTFT), prior experience, and time out during training (OOP). The primary outcome was the percentage of cases undertaken as lead surgeon (supervised and unsupervised) by UK orthopaedic trainees by gender. Results. All participants gave permission for their data to be used. In total, 274 UK orthopaedic trainees submitted data (65% men (n = 177) and 33% women (n = 91)), with a total of 285,915 surgical procedures logged over 1,364 trainee-years. Males were lead surgeon (under supervision) on 3% more cases than females (61% (115,948/189,378) to 58% (50,285/86,375), respectively; p < 0.001), and independent operator (unsupervised) on 1% more cases. A similar trend of higher operative numbers in male trainees was seen for senior (ST6 to 8) trainees (+5% and +1%; p < 0.001), those with no time OOP (+6% and +8%; p < 0.001), and those with orthopaedic experience prior to orthopaedic specialty training (+7% and +3% for lead surgeon and independent operator, respectively; p < 0.001). The gender difference was less marked for those on LTFT training, those who took time OOP, and those with no prior orthopaedic experience. Conclusion. This study showed that males perform 3% more cases as the lead surgeon than females during UK orthopaedic training (p < 0.001). This may be due to differences in how cases are recorded, but must engender further research to ensure that all surgeons are treated equitably during their training. Cite this article: Bone Joint J 2023;105-B(7):821–832

For all the research into arthroplasty, provision of total knee arthroplasty (TKR) services based on gender in the Australian context is yet to be explored. International literature points toward a heavily gender biased provision of TKA services, skewed away from female patients. This research has aimed to assess the current experience of Australian female patients and to explore better assessment techniques that could provide more equitable services. A retrospective cohort analysis has been conducted using pre-op PROMs data, where available, from the Australian National Joint Replacement Registry (AOANJRR), between 7 August 2018 and 31 December 2021, including: EQ VAS Health; Oxford Knee Score; joint pain; and KOOS-12. Data was adjusted for age, ASA score, BMI, primary diagnosis, public vs private hospital, surgeon gender and years of practice (as estimated from years of registry data available). Of 1,001,231 procedures performed, 27,431 were able to be analysed (12,300 male and 15,131 female). Gender-based bias against female patients reached statistical significance across all PROM scores, according to the Kruskal-Wallis test of difference (p-value <0.0001). Males were more likely to undergo TKR than females, with odds ratios remaining statistically significant when adjusted for age, ASA score, BMI, primary diagnosis, and hospital type. Numbers were further analysed for surgeon years of recorded practice and surgeon gender with mixed results. This study found that women were less likely to undergo TKR despite worse scores on every pre-op PROM available, thus we demonstrate a statistically significant gender-based bias against female patients. More effort needs to be made to identify the base of this bias and find new ways to assess patients that can provide more equitable provision of healthcare

This qualitative study aims to explore and highlight the experiences of trainees in the Orthopaedic Surgical Education Training (SET) program in New Zealand, with a focus on identifying gender-specific biases which may impact professional development. Orthopaedic SET trainees in New Zealand were invited to complete a qualitative, semi-structured questionnaire exploring their experiences in the Orthopaedic SET program. A broad range of topics were covered, addressing culture, belonging, learning styles and role modelling. Recurrent themes were identified using inductive methods. Analysis of questionnaire responses identified several key themes for women in the Orthopaedic SET program, compared to their male counterparts, including (1) role incredulity, (2) confidence vs. competence, (3) adaptation, (4) interdisciplinary relationships and (5) role modelling. Female participants described experiencing gender bias or discrimination by both patients and interdisciplinary colleagues at a higher rate than their male counterparts. The majority of female participants described feeling as competent as their male counterparts at the same SET level, however, identified that they do not typically exhibit the same confidence in their surgical abilities. Whilst similar numbers of female and male participants described experiencing barriers to career progression, female participants described having to adapt both physically and socially to overcome additional gender-specific barriers. Positive influences on training experience included role modelling and supportive relationships amongst trainee groups. This study highlighted gender-specific biases experienced by trainees in the Orthopaedic SET program in New Zealand. Further investigation is warranted to determine how these experiences affect professional development, and how they may be addressed to foster increased gender equity in the surgical profession. This will likely require system-level interventions to create meaningful and sustainable culture change

Distal radius fractures are the most common upper extremity fracture. The incidence is significantly higher in elderly females with osteoporotic bone. When surgery is indicated, volar locking plates (VLPs) allow for rigid fixation particularly in comminuted fractures with poor bone quality. Although numerous studies have shown the importance of plate placement to avoid soft tissue complications associated with volar plate fixation, there has been little evidence on the anatomic fit of current VLPs. Moreover, the effect of gender differences in distal radius morphology on anatomic fitting of VLPs has not been studied. The aim of this study was to evaluate the gender difference in distal radius morphology and the accuracy of the fit of a current VLP to CT-based distal radius models. Segmented CT models of ten female (mean age, 89 ± 5 years), and ten male (mean age, 86 ± 4 years) cadaveric wrists were obtained. Micro-CT models of the DePuy-Synthes 4-hole extra-articular (EA) and 8-hole volar column (VC) distal radius VLPs were created. A 3D visualization software was used to simulate appropriate plate placement on to the distal radius models by a fellowship-trained hand surgeon. Volar cortical angles (VCA) of the medial, middle and lateral portion of the distal radius were measured and compared between genders. The accuracy of the fit of the two VLP designs were quantified using the percentage of the watershed line (WSL) overlapped by the plate (WSL overlap), the distance between the WSL and the most distal aspect of the posterior plate (prominence distance) and the percentage of contact between the plate and bone. There were statistically significant gender differences in medial, middle and lateral VCAs (p=.003 medial, p=.0001 middle, p=.002 lateral). VCA ranged from 28° to 36° in females and from 38° to 45° in males. The WSL overlap did not show statistically significant gender differences (male: 5.9%, female: 13.6%, p=.174). However, the difference in prominence distance between different genders approached statistical significance (male: 3.5mm, female: 2.6mm, p=.087). Contact mapping between the plate and bone did not demonstrate a perfect contact in any of our specimens. Thus, contact measurements were categorized into 0.1mm, 0.2mm, and 0.3mm threshold contacts. There were no statistically significant gender differences in any of the threshold categories (0.1mm: p=.84, 0.2mm: p=.97, 0.3mm: p=.99). Our results confirm that there are gender differences in distal radius morphology. Current plate designs incorporate a VCA of 25° which does not match the native VCA of the distal radius in males or females. Although the difference in prominence distance approached statistical significance, there were no statistically significant gender differences in the WSL overlap or the contact threshold values. This lack of statistical significance may be related to the small sample size. This study proposes novel methods of assessing the anatomic fit of current VLPs in a 3D CT-based model that may be used in future studies with a larger sample size. Moreover, this study demonstrated the importance of considering gender differences in distal radius morphology in the design of future generations of implants

Aims

Our primary aim was to establish the proportion of female orthopaedic consultants who perform arthroplasty via cases submitted to the National Joint Registry (NJR), which covers England, Wales, Northern Ireland, the Isle of Man, and Guernsey. Secondary aims included comparing time since specialist registration, private practice participation, and number of hospitals worked in between male and female surgeons.

End-stage ankle arthritis (ESAA) is a debilitating disease that does not affect all individuals equally. Gender differences have been identified in patients with end-stage hip and knee arthritis and have stimulated research to explain these findings. The present study was undertaken to examine if gender has a significant effect on pre-operative disability and post-operative outcomes in patients with ESAA. Patients undergoing ankle arthrodesis (AA) or total ankle replacement (TAR) with minimum 2-year follow-up were identified in the Canadian Orthopaedic Foot and Ankle Society prospective ankle reconstruction database. Demographic data, revision data, patient satisfaction questionnaires, and outcome data using the Ankle Osteoarthritis Scale (AOS) and Short-form 36 (SF-36) health survey were collected. TAR: 384 patients were included, with 198 females and 186 males. Patient BMI, comorbidities, and duration of follow-up were similar between groups. Males were slightly older at the time of surgery (65.1 vs 62.4 years, p=0.01)). The most common etiology was post-traumatic arthritis for both genders, however females had a higher rate of rheumatoid arthritis (17% vs 5%, p=0.001). Implant types included STAR, Hintegra, and Mobility, and were similar between groups. Preoperatively females had higher rates of pain and disability, demonstrated by lower SF-36 physical component scores (PCS) (31.0 vs 34.5, p<0.001), and higher AOS pain (54.7 vs 51.1, p=0.05) and AOS disability scores (66.5 vs 59.6, p<0.001). Postoperatively, both groups had significant improvement in PCS, AOS pain, and AOS disability scores. Females, however, continued to demonstrate lower PCS scores (38.3 vs 41.9, p<0.001) and higher AOS disability (31.0 vs 25.8, p=0.02) than males. Regression analysis found that preoperative PCS, gender, age, and arthritis etiology all had a significant impact on postoperative PCS scores, with preoperative PCS scores having the largest impact. Preoperative AOS pain and disability scores had the largest impact on postoperative AOS pain and disability scores, respectively. Gender had no significant impact on AOS pain and disability scores postoperatively. Patient satisfaction was similar between males and females postoperatively. Secondary surgery was performed in 13.6% of females and 16.1% of males. Five males and five females underwent revision to arthrodesis. In patients with ESAA, females tend to have higher pre-operative levels of pain and disability compared to males, which persists post-operatively. This is consistent with the hip and knee arthroplasty literature. This finding may be due to females undergoing surgery at more advanced disease states, arthritis etiology, referral bias, or treatment bias. Both males and females have significant and similar degrees of improvement in pain and disability scores after TAR, and reoperation rates and patient satisfaction rates are similar despite the apparent disparity in outcomes

For many patients, UKA is a good alternative to total knee arthroplasty (TKA) or high tibial osteotomy (HTO). Strong evidence that gender influences outcomes following UKA could alter UKA selection criteria. No prior series has been specifically designed and matched to compare outcomes based on gender. The purpose of this study was to elucidate the effect of gender on the clinical outcome of UKA while controlling for other variables that may affect outcome. Between 1988 and 2006, 257 UKA's were carried out in our department. We studied two groups of 40 patients of each gender, matched by pre-operative clinical and radiological presentation, and with post-operative follow up of at least 2 years. The mean age at operation was 71 years and the mean follow-up was 5.9 years. In both groups, IKS score improved significantly. When comparing the male and female groups post-operatively, no significant differences were found between IKS knee or function scores, limb alignment, or the incidence of radiolucent lines. No difference was found between groups in terms of range of motion or radiologic progression of arthritis. Both tibial (p<0.001) and femoral (p<0.001) component sizes were significantly larger in the male group than the female group. For males, the size of both the femoral (r2=0.12, p=0.033) and tibial (r2=0.29, p=0.0005) components correlated with patient height. For females, the size of neither the femoral (r2=0.000082, p=0.96) nor tibial (r2=0.0065, p=0.63) components correlated with patient height. The key finding in this study is that when patients are selected for UKA according to specific selection criteria (including avoiding performance of UKA in younger patients and patients over 85 kg), gender is not a predictor of outcome based on IKS scores. When using these selection criteria, gender should not be considered when determining whether to perform a UKA

Management of the pathologic long-head biceps tendon remains controversial. Biceps tenotomy is a simple intervention but may result in visible deformity and subjective cramping. Comparatively, biceps tenodesis is technically challenging, and has increased operative times, and a more prolonged recovery. The purpose of this study was to determine the incidence of popeye deformity following biceps tenotomy versus tenodesis, identify predictors for developing a deformity, and compare subjective and objective outcomes between those that have one and those that do not. Data for this study were collected as part of a randomized clinical trial comparing tenodesis versus tenotomy in the treatment of lesions of the long head of biceps tendon. Patients 18 years of age or older with an arthroscopy confirmed biceps lesion were randomized to one of these two techniques. The primary outcome measure for this sub-study was the rate of a popeye deformity at 24-months post-operative as determined by an evaluator blinded to group allocation. Secondary outcomes were patient reported presence/absence of a popeye deformity, satisfaction with the appearance of their arm, as well as pain and cramping on a VAS. Isometric elbow flexion and supination strength were also measured. Interrater reliability (Cohen's kappa) was calculated between patient and evaluator on the presence of a deformity, and logistic regression was used to identify predictors of its occurrence. Linear regression was performed to identify if age, gender, or BMI were predictive of satisfaction in appearance if a deformity was present. Fifty-six participants were randomly assigned to each group of which 42 in the tenodesis group and 45 in the tenotomy group completed a 24-month follow-up. The incidence of popeye deformity was 9.5% (4/42) in the tenodesis group and 33% (15/45) in the tenotomy group (18 male, 1 female) with a relative risk of 3.5 (p=0.016). There was strong interrater agreement between evaluator and patient perceived deformity (kappa=0.636; p<0.001). Gender tended towards being a significant predictor of having a popeye with males having 6.6 greater odds (p=0.090). BMI also tended towards significance with lower BMI predictive of popeye deformity (OR 1.21; p=0.051). Age was not predictive (p=0.191). Mean (SD) satisfaction score regarding the appearance of their popeye deformity was 7.3 (2.6). Age was a significant predictor, with lower age associated with decreased satisfaction (F=14.951, adjusted r2=0.582, p=0.004), but there was no association with gender (p=0.083) or BMI (p=0.949). There were no differences in pain, cramping, or strength between those who had a popeye deformity and those who did not. The risk of developing a popeye deformity was 3.5 times higher after tenotomy compared to tenodesis. Male gender and lower BMI tended towards being predictive of having a deformity; however, those with a high BMI may have had popeye deformities that were not as visually apparent to an examiner as those with a lower BMI. Younger patients were significantly less satisfied with a deformity despite no difference in functional outcomes at 24 months. Thus, biceps tenodesis may be favored in younger patients with low BMI to mitigate the risk of an unsatisfactory popeye deformity

Introduction. Previous anthropometric studies have reported gender differences in distal femoral morphology. After total knee arthroplasty, females have a higher prevalence of medial or lateral femoral component overhang, which could be responsible for postoperative knee pain and decreased range of motion. Consequently, gender-specific knee prostheses were designed to accommodate female morphology. However, to date, very few studies have investigated the knee morphology of Japanese adults and possible gender differences. The purpose of this study was to examine the distal femoral morphology of Japanese patients, to characterize anatomical differences between men and women, and to evaluate the need to create gender-specific knee prostheses. Material and Methods. We evaluated 107 knees in 17 male and 90 female Japanese patients for total knee arthroplasty (TKA)[fig.1]. The medial-lateral (ML) and anteroposterior (AP) dimensions of the knees at different levels evaluated intraoperative measurement, and ML/AP aspect ratios were calculated. Results. On the distal femoral cut surface, the mean ML widths were 74.8 mm for men and 65.5 mm for women. Such values were generally smaller compared to data from European and North American studies. In this study, the mean ML/AP aspect ratios were 1.21 for men and 1.13 for women, higher than those from non-Asian regions. The ML/AP ratios of Japanese patients were negatively correlated with distal femoral AP length. Discussion. The dimensions and sizes of the human femur have been reported in the literature, as measured by dissection of cadaver knees, plain radiographs or CT scans of living subjects, or other means. Compared to data on knees from European and North American populations, femoral ML/AP ratios were smaller for a given AP length in Japanese individuals. In addition, the mean AP and ML distances of the distal femur of Japanese individuals were smaller than those of Western populations, which could be associated with differences in height or other physical and skeletal characteristics. Several studies reported significant gender difference in the ML/AP ratio. Because of the shapes of the distal femur were more trapezoidal for women and more rectangular for men. After TKA, females have a higher prevalence of medial or lateral femoral component overhang, which could be responsible for postoperative knee pain and decreased range of motion. Our results suggest that gender-specific knee prostheses may prevent such postoperative complications. Conclusions. Japanese women had a relatively narrower femoral width for a given AP length than men. Our study suggests the utility of Japanese-specific implants and provides useful insights for manufacturers to design components of appropriate sizes and aspect ratios for Japanese TKA patients

The use of Patient Reported Outcome Measures (PROMS) has been critical to the success of total joint arthroplasty (TJA). They have made possible the evaluations of new implants, materials and surgical techniques that have been essential to the development of these technologies. PROMS have had a major impact on the decisions that surgeons make regarding treatment and care of patients. However, there are serious limitations of PROMS. They are useless in the first few weeks after surgery. They provide very little objective functional information to which health care providers can respond in the early, critical post-operative period. PROMS do not objectively measure specific outcome measures (e.g. ROM, distance walked). PROMS are also cumbersome and time consuming to use. Joint specific surface sensors are emerging to allow objective measurements of specific functional outcomes of knee surgery. This allows an examination of the factors that might affect these functional outcomes. The purpose of this study was to examine the relationship of age, gender, BMI and pain following TKA on ROM and activity measured using a joint specific surface sensor. Methods. 40 patients who underwent primary cruciate retaining TKA using the same implant system and patient specific instrumentation (PSI) were followed for 3 weeks with a knee specific surface sensor (TracPatch. tm. ). The device was applied one day following surgery. Standard post-TKA care protocols were used. The ROM and distance walked was measured by the device. The relationship of these outcomes to patients’ age, gender, BMI and pain were examined. Results. All but one patient tolerated the device. This patient had a superficial, transient skin reaction to the adhesive and was not included in the study. Patients under 60 regained more motion and were more active in the first 3 weeks after surgery than patients 60–69 and patients 70+. Gender had no significant impact on ROM or activity for each age group. BMI under 30 had no impact on ROM or activity. BMI over 40 had a significant impact on both ROM and activity. Pain had very little impact on ROM and moderate impact on activity in the first 3 weeks after surgery. Summary. Joint specific sensors are becoming available to provide objective measurements of a joint's function. The knee specific sensors used in this study measured the number of steps taken and ROM in patients who underwent a primary, cruciate retaining TKA. The device was liked and well tolerated by patients. ROM was affected by age and BMI, but not by gender or, to a significant degree, by pain. The device will be useful in focusing therapy on those patients who most need it. Use of the device has the potential of making post-surgical care more effective and cost efficient

Introduction. Numerous fluoroscopic studies have been conducted to investigate kinematic variabilities of total knee arthroplasty (TKA). In those studies, subjects having a posterior stabilized (PS) TKA experience greater weightbearing knee flexion and posterior femoral rollback of the lateral condyle. In those same studies, subjects did experience a high incidence of variable medial condyle motion and reverse axial rotation, especially occurring when the cam engaged the post. More recently, a PS TKA was designed to accommodate both gender and ethnicity. Therefore, the objective of this study was to assess in vivo kinematics for subjects having this TKA type to determine if subjects having this PS TKA experienced more optimal knee kinematics. Methods. Twenty-five subjects in this study were asked to perform a deep knee bend to maximum knee flexion and a step-up maneuver while under fluoroscopic surveillance. All subjects were patients of one experienced surgeon and received the same PS TKA. Using a 3D-2D registration technique, the CAD models, supplied by the sponsoring company, were superimposed over x-ray images at specified increments throughout the fluoroscopic footage. The kinematics were then analyzed to evaluate lateral anterior/posterior (LAP) and medial anterior/posterior (MAP) condyle translation as well as axial rotation of the femur with respect to the tibia. Results. During the DKB activity, the average flexion for the PS TKA subjects was 1108°. On average subjects experienced a lateral condyle motion in the posterior direction of 7.3mm, with the maximum amount of posterior rollback being 12.8 mm. These same subjects experienced an average medial condyle motion in the posterior direction of 4.8 mm with the maximum amount of posterior motion being 7.8 mm. Therefore, with the lateral condyle rolling more posterior than the medial condyle, these subjects experienced an average amount of 7.1° of axial rotation, with a maximum of 12.0°. Only one subject in this study experienced a reverse axial rotation from full extension to maximum knee flexion. During the step-up maneuver, subjects consistently experienced a roll forward motion of both their condyles. Discussion. Subjects in this study experienced a high incidence and magnitude of lateral condyle posterior femoral rollback, leading a normal-like axial rotation pattern, although less in magnitude compared to the normal knee. There was variability occurring with the medial condyle as some experience experienced an anterior slide while others rolled in the posterior direction. As seen in previous studies, during mid flexion both condyles experienced a more variable motion pattern. Twenty-five subjects having a posterior cruciate retaining TKA are being added to this study to determine if retention of the PCL in a similarly designed TKA leads to more normal-like kinematic patterns

Given their role in reducing anterior tibial translation, the recruitment patterns and viscoelastic properties of the hamstring muscles have been implicated as neuromuscular factors contributing to the ACL gender bias. Nevertheless, it is uncertain whether patterns of aberration displayed by the female neuromuscular system significantly alters the antagonist moments generated by the hamstrings during maximal effort knee extension. The purpose of the current study was to examine the effect of gender on hamstring antagonist moments in order to explain the higher ACL injury rates in females. Eleven females (age 30.6 ± 10.1 years, mass 62.1± 6.9 kg, height 165.9 ± 4.6) and 11 males (age 29.0 ± 8.2 years, mass 78.6± 14.4 kg, height 178.5± 6.2) were recruited as subjects. Surface electrodes were placed over the semitendinosus (ST) and biceps femoris (BF) muscles of the dominant and non-dominant limbs. Each subject performed two sets of five maximal extension and flexion repetitions at 180-1. EMG, isokinetic torque and knee displacement data were sampled at 1000Hz using an AMLAB data acquisition system. Average hamstring antagonist torque data across the range of knee flexion for female subjects was significantly higher (%Diff=24%) than for the male control subject. Statistical analyses revealed a significant main effect of gender (F = 4.802; p = 0.036). Given that females possess a more compliant ACL and hamstring musculature, compared with their male counterparts, an augmented hamstring antagonist may represent a compensatory neuromuscular strategy to increase knee stiffness to control tibial translation and ACL strain. The results of this project suggest that it is unlikely that gender-related differences in hamstring antagonist torque is one of the predisposing factors contributing to the higher ACL injury rates in females

Introduction:. Recent studies have concluded that gender influences hip morphology at the time of surgery as well as dysplastic development of the hip. This may lead to a particular choice of implant including stem design and/or neck modularity. In this study we hypothesized that not only gender but also morphotype and etiology (primary osteoarthritis versus aseptic osteonecrosis) may be a significant factor to predict the anatomy of the hip at the time of total hip arthroplasty (THA). Methods:. We reviewed 690 patients undergoing THA for primary arthritis (OA) or avascular osteonecrosis (AVN) between April 2000 and June 2005 and stratified each into three groups based on their anatomic constitution: endomorph (EN), ectomorph (ECT), or mesomorph (ME) (determined by the ratio: pelvic width/total leg length measured on full-length X-rays). Two independent observers measured twice four parameters on preoperative CT scan: neck-shaft-angle angle (NSA), femoral offset value (FO), helitorsion (Ht) value and femoral neck anteversion (Av). Results:. No significant difference were observed between men and women for the four parameters with respectively: NSA (129.29° ± 5.6 versus 129.3° ± 5.7), Av (20.3° ± 8.6 versus 20.27° ± 8.6), FO (19.7 mm ± 3.98 versus 19.74 mm ± 3.98) and Ht (19.97° ± 12.2 for men and 19.94° ± 12.3). Significant difference were found for NSA: 130.1° ± 5.8 for ECT, 129.55° ± 6 for MES and 128.2° ± 5,1 for EN with p < 0.01. For Av, the values were: 18.9° ± 8.7 for ECT, 20.74° ± 8.1 for MES and 21.2° ± 8.95 for EN (p < 0.01). For FO the values were 19.1 mm ± 3.9 for ECT, 19.7 ± 4 for MES and and 20.44 mm ± 3.93 for EN (p < 0.01). No difference was found for Ht between the 3 groups. A significant difference was found between patients suffering from OA and AVN: mean NSA was 130.36° ± 8.79 for OA patients versus 127.35° ± 8.38 for those who had an AVN (p < 0.01). A value was 17.06° ± 8.1 for OA and 23.7 ± 7.89 for AVN (p < 0.01). FO value was 18.72 mm ± 3.71 for OA versus 20.75 mm ± 4.15 for AVN (p <0.01). And Ht was 18.94° ± 9.64 for OA and 21.05° ± 14.5 for AVN patients (p < 0.01). Discussion and conclusion:. Patients with short and wide morphotype (endomorph) had, irrespective of gender, lower values of NSA with greater anterversion and offset values, whereas patients with long and narrow morphotype (ectomorph) had higher values of NSA and smaller Av and FO (figure 1). In the same time patients suffering from AVN have lower NSA angle, lower Av, smaller FO and Ht (figure 2). Femoral stem design should allow the consideration of these differences to optimize the reconstruction of the hip at the time of THA including pre-operative and intra-operative modularity

Total Knee Arthroplasty (TKA) has a tendency to change the individual anatomy of the patient within the limits of today used arthroplasty designs. Femoral external rotation will lead to mediolateral overhang by upsizing to avoid lateral notching and downsizing will lead to loss of posterior condylar offset. Posterior slope is usually reduced to avoid problems with posterior stabilized (PS) designs. We compared 50 bicompartimental arthroplasties (Uni + PFJ) with 50 TKA's. Demographics and BMI are compared. We looked specifically at patient type, preoperative deformity, postoperative function and alignment and results on functional scores. Bicompartimental arthroplasty is a resurfacing intervention that allows less correction of frontal deformity. Postop alignment was within 3° of varus. Better active flexion was obtained than in TKA. Better function was observed for stair climbing and single leg stability. Rotational position of foot was more natural in bicompartimental as compared to TKA. Functional scores like WOMAC, KOOS and IKDC showed better results for bicompartimental. Illness perception score showed that the resurfacing patient is another patient than the TKA patient. No overhang of components was observed. No change of posterior condylar offset was necessary. Posterior slope on the medial side was minimally reduced. In conclusion resurfacing by bicompartimental arthroplasty with two individual components (Uni + PFJ) is an excellent solution to gender and ethnic differences. The individual anatomy of the specific patient goes through minimal changes resulting in better functional results

Introduction. Opponents of patellar resurfacing during Total Knee Arthroplasty (TKA) note unique complications associated with resurfacing. Problems include over-stuffing (the creation of a composite patellar-prosthesis thickness greater than the native patella) that may contribute to reduced range of motion; and creation of a patellar remnant that is too thin (in order to avoid over-stuffing) that may contribute to post-operative fracture. Factors including surgical technique, prosthesis design and patient anatomy may contribute to these problems. This study was performed to define the native patellar anatomy, and to compare the effect of differences in component thickness between manufacturers. Methods. This retrospective, IRB approved study reviewed 803 knees that underwent primary TKA between 2005 and 2011 with a single surgeon. Patellar resurfacing was performed with a round, polyethylene component from one of two different implant designs using the same surgical technique. Data recorded for each patient included: gender; patellar thickness before and after resurfacing; the dimensions and manufacturer of the prosthesis. The residual patellar bone thickness after resection was calculated. Results. Mean (SD) native patellar thickness was 25.24mm (2.11) in males, versus 22.13mm (1.89) in females (P = <0.001). 47/313 (15%) of males had increases in the composite patellar thickness after resurfacing, versus 120/480 (25%) of females (P < 0.001). 123/480 (26%) of females had a residual patella thickness <= 13mm, versus 12/313 (4%) of males (P <0.001). Finally, 79/265 (30%) of patients with a patellar prosthesis from manufacturer B had increases in the composite thickness, versus 88/522 (17%) of patients with manufacturer A (P < 0.001). Conclusions. Both patient gender (due to smaller native patellae in females) and prosthesis design (thicker components from manufacturer B) are risk factors for over-stuffing of the patella or over-resection of the patella. These findings suggest that patellar component design can be improved for female patients

Introduction. The use of screws is frequent for additional fixation, however, since some disadvantages have been reported a cup press-fit is desirable, although this can not always be obtained. Cup primary intraoperative fixation in uncemented total hip replacement (THR) depends on sex, acetabular shape, and surgical technique. We analyzed different factors related to primary bone fixation of five different designs in patients only diagnosed with osteoarthritis, excluding severe congenital hip disease and inflammatory arthritis, and their clinical and radiological outcome. Materials y Methods. 791 hips operated in our Institution between 2002 and 2012 were included for the analysis. All cases were operated with the same press-fit technique, and screws were used according to the pull-out test. Two screws were used if there was any movement after the mentioned manoeuvres. Acetabular and femoral radiological shapes were classified according to Dorr et al. We analyzed radiological postoperative cup position for acetabular abduction angle, the horizontal distance and the vertical distance. Cup anteversion was evaluated according to Widmer and the hip rotation centre according to Ranawat. Results. Screws were required in 155 hips (19.6%) and were more frequently used in women and patients with a type A acetabulum (p<0.001, p=0.021, respectively). There were no differences among the different cups evaluated. The need for screws was more frequent in hips with a smaller version of the cup and with a distance greater than 2 mm to the approximate femoral head centre from the centre of the prosthetic femoral head (p=0.022, 0.012, respectively). Adjusted multivariate analysis revealed that female patients (p<0.001, Odds Ratio (OR): 2.063; 95% Confidence Interval (CI) 1.409–3.020), cups with a smaller version (p=0.012, OR: 0.966, 95% CI 0.94–0.992), and a greater distance to the rotation hip center (p<0.005, OR: 1.695; 95% CI 1.173–2.450) had a higher risk for screw use. No hips needed revision for aseptic loosening. Conclusions. Cup press-fit depends on gender and surgical technique in hips without significant acetabular abnormalities or inflammatory arthritis. Contemporary uncemented cups provide similar primary fixation and mid-term outcome

Introduction. Uncemented press-fit cups provide bone fixation in primary total hip replacement (THR). However, sometimes screws are needed to achieve primary stability of the socket. We analyzed biomechanical factors related to press-fit in seven cup designs and assessed whether screw use provides similar loosening rates to those of the press-fit technique. Materials y Methods. From a series of 1,350 primary uncemented THRs using seven different press-fit cup designs (a dome loading hemispheric cup and bi- or tri- radius cups), we only analyzed the 889 diagnosed of primary osteoarthritis. All cases were operated by the same surgical team. The use of screws was decided intraoperatively based on cup stability according to the pull-out test. There were 399 female and 490 male patients with a mean age of 65 years old. The mean follow-up was 8.6 years (5–13 years). The reconstruction of the hip rotation center was evaluated according to Ranawat. Results. Screws were required in 223 (25.1%) of the surgeries: 35% of all dome-loaded cups and less frequently with other cup designs (range 18%-24%) (p<0.001) All hips showed good clinical results and radiological bone fixation. Screws were used more frequently in women (p<0.001). Adjusted multivariate analysis revealed that female patients (p<0.001, Odds Ratio (OR): 1.98; 95% Confidence Interval (CI) 1.34–2.95), hips with one of the hemispherical cup designs (p=0.01, OR: 2.51; 95% CI 1.33–5.33) and a greater distance to the rotation hip centre (p<0.001, OR: 1.25; 95% CI 1.15–1.35) had a higher risk for screw use. Every increase of 5 mm in this distance increased the risk of screw use by three (LI=2–4.5). Conclusions. Gender, cup design and reconstruction of the rotation center of the hip determine the primary stability of the cup in uncemented THR. The use of screws, when necessary, provides similar results than the press-fit technique

Introduction. Accurate alignment and sizing of the femoral component in total knee arthroplasty (TKA) is important for stability and functional outcomes. In relation to the shape of the distal femur, it has been reported that the medial-lateral (ML) femur width in women is narrower than that in men for the same antero-posterior (AP) length. In addition, it has been noted that the elevation of the anterior condyle in women is lower than that in men. Therefore, in TKA for women, it is suggested that a medial or lateral overhanging femoral component can cause pain or limit the range of motion (ROM). As a result, a gender-specific implant for women has been developed. However, there are few studies addressing the morphological dimensions of the distal shape of the femur in the Japanese population. The objective of this study was to reveal the appropriateness of using gender-specific implant for Japanese women. Methods. This study was based on 40 women (40 knees) and 40 men (40 knees) who had primary preoperative osteoarthritis of the knee. The average height was 161.2 cm for men and 149.4 cm for women. The average weight was 68.0 kg for men and 58.5 kg for women. These are significantly different. Resection of the distal femur for TKA was simulated with preoperative computed tomography (CT) data. The ML width on the anterior and distal cut surface, the ML width at the surgical epicondylar axis (SEA) level, the maximum AP length at the medial and lateral condyle, and the AP length after resection were measured. These values were compared between men and women, and compatibility with NexGen LPS-Flex and Gender Solution Femur (GSF) (Zimmer, Warsow, Ind) was evaluated. Results. On the anterior cut surface, the average ML width was 54.0 mm for men and 47.0 mm for women. There was a significant difference between them (P<0.01). The aspect ratio (AP/ML) at the SEA level and the resected distal surface was 0.74 and 0.65 for men and 0.76 and 0.70 for women, respectively. There were significant differences between them (P<0.01). Discussion and Conclusion. In general, the aspect ratio of the distal femur in the Japanese population was smaller than that in the Caucasian population. However, the femoral distal shape in women was narrower than that in men for the same AP length in the Japanese population. As the AP size increased, the femoral component in women tended to overhang the ML width. Therefore, the use of a gender-specific implant for women was suggested. In contrast, there were some cases in which the femoral component tended to be undersized compared with the ML width in men. [Fig. 1] For Japanese women, the use of a gender-specific component should be considered. Additionally, there is a need for further investigation of gender-specific components in men

Background. Recent anthropometric studies have suggested that current design of total knee arthroplasty (TKA) does not cater to racial anthropometric differences. The purpose of this study was to investigate the exact sizing and rotational landmarks of the distal femur collected and its gender differences from a large group of healthy Southern Chinese using 3D-CT measurements, and then compare these measurements to the five total knee prostheses conventionally used in China. Methods. This study evaluated distal femoral geometry in 85 healthy Southern Chinese, included 39 females (78 knees) and 46 males (92 knees) with a mean age of 33.9 years，a mean height of 164.7 cm and a mean weight of 59.9 kg. The width of the articular surface as projected onto the transepicondylar line(ML), anteroposterior dimension (AP), the dimensions from medial/lateral epicondyle to posterior condylar (MEP/LEP) were measured. A characterization of the aspect ratio (ML/AP) was made for distal femur. The angles between the tangent line of the posterior condylar surfaces, the Whiteside line, the transepicondylar line, and the trochlear line were measured. The sulcus angle and hip center-femoral shaft angle were also measured [Fig. 1]. The data were compared with the five total knee prostheses conventionally used in China. In analyzing the data, best-fit lines were calculated with use of least-squares regression. The dimensions are summarized as the mean and standard deviation. Comparisons of dimensions between males and females were made with use of the two-sample t test. A p value of <0.05 indicated a significant effect. Results. Within the population, males had larger ML, AP values and aspect ratio than females (ML: 70.44±3.04 vs. 61.40±2.62 mm, P<0.001; AP: 62.26±2.93 vs. 56.49±2.88 mm, P<0.001; 1.06±0.05 vs. 1.11±0.03, P<0.001). In addition, we found a gradual decrease in the aspect ratio corresponding to an increase in AP dimension, as seen in other studies. The transepicondylar axis was a reliable landmark to properly rotate the femoral component, so we used the MEP and LEP evaluate posterior condylar offset, the values were respectively 28.90±3.00 mm and 22.73±2.67 mm. However, most angles were almost the same between males and females. To evaluate the suitability shape of the femoral components currently used in China, we drawed and calculated best-fit lines for the AP, ML dimensions and aspect ratios of the femur and the five prostheses. For females, there was a significant association between the prostheses size and the amount of overhang, the femoral prostheses for females tended to be too large for a given AP dimension, with larger sizes having more overhang, especially in ML dimensions. In males, the morphologic data tended to be bigger than the prosthetic designs in the ML dimension for a given AP dimension, the femoral aspect ratio was higher for smaller knees and proportionally lower for larger knees[Fig. 2, 3]. Conclusion. Because dimensions of the distal femur and the aspect ratio tend to be smaller in Southern Chinese populations, whereas sulcus angles tend to be larger, designs for knee implants should be modified to improve the outcome of surgical treatment in this population

Background

Humeral version is the twist angle of the humeral head relative to the distal humerus. Pre-operatively, it is most commonly measured referencing the transepicondylar axis, although various techniques are described in literature (Matsumura et al. 2014, Edelson 1999, Boileau et al., 2008). Accurate estimation of the version angle is important for humeral head osteotomy in preparation for shoulder arthroplasty, as deviations from native version can result in prosthesis malalignment. Most humeral head osteotomy guides instruct the surgeon to reference the ulnar axis with the elbow flexed at 90°. Average version values have been reported at 17.6° relative to the transepicondylar axis and 28.8° relative to the ulnar axis (Hernigou, Duparc, and Hernigou 2014), although it is highly variable and has been reported to range from 10° to 55° (Pearl and Volk 1999). These studies used 2D CT images; however, 2D has been shown to be unreliable for many glenohumeral measurements (Terrier 2015, Jacxsens 2015, Budge 2011). Three-dimensional (3D) modeling is now widely available and may improve the accuracy of version measurements. This study evaluated the effects of sex and measurement system on 3D version measurements made using the transepicondylar and ulnar axis methods, and additionally a flexion-extension axis commonly used in biomechanics.