Aims. The primary aim was to assess whether robotic total knee arthroplasty (rTKA) had a greater early knee-specific outcome when compared to manual TKA (mTKA). Secondary aims were to assess whether rTKA was associated with improved expectation fulfilment, health-related quality of life (HRQoL), and patient satisfaction when compared to mTKA. Methods. A randomized controlled trial was undertaken, and patients were randomized to either mTKA or rTKA. The primary objective was functional improvement at six months. Overall, 100 patients were randomized, 50 to each group, of whom 46 rTKA and 41 mTKA patients were available for review at six months following surgery. There were no differences between the two groups. Results. There was no difference between rTKA and mTKA groups at six months according to the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) functional score (mean difference (MD) 3.8 (95% confidence interval (CI) -5.6 to 13.1); p = 0.425). There was a greater improvement in the WOMAC pain score at two months (MD 9.5 (95% CI 0.6 to 18.3); p = 0.037) in the rTKA group, although by six months no significant difference was observed (MD 6.7 (95% CI -3.6 to 17.1); p = 0.198). The rTKA group were more likely to achieve a minimal important change in their WOMAC pain score when compared to the mTKA group at two months (n = 36 (78.3%) vs n = 24 (58.5%); p = 0.047) and at six months (n = 40 (87.0%) vs n = 29 (68.3%); p = 0.036). There was no difference in satisfaction between the rTKA group (97.8%; n = 45/46) and the mTKA group (87.8%; n = 36/41) at six months (p = 0.096). There were no differences in EuroQol five-dimension questionnaire (EQ-5D) utility gain (p ≥ 0.389) or fulfilment of patient expectation (p ≥ 0.054) between the groups. Conclusion. There were no statistically significant or clinically meaningful differences in the change in WOMAC function between mTKA and rTKA at six months. rTKA was associated with a higher likelihood of achieving a clinically important change in knee pain at two and six months, but no differences in knee-specific function, patient satisfaction, health-related quality of life, or expectation fulfilment were observed. Cite this article: Bone Joint J 2023;105-B(9):961–970

Aims. The primary aim of this study was to assess whether pain in the contralateral knee had a clinically significant influence on the outcome of total knee arthroplasty (TKA) according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Secondary aims were to: describe the prevalence of contralateral knee pain; identify if it clinically improves after TKA; and assess whether contralateral knee pain independently influences patient satisfaction with their TKA. Methods. A retrospective cohort of 3,178 primary TKA patients were identified from an arthroplasty database. Patient characteristics, comorbidities, and WOMAC scores were collected preoperatively and one year postoperatively for the index knee. In addition, WOMAC pain scores were also collected for the contralateral knee. Overall patient satisfaction was assessed at one year. Preoperative contralateral knee pain was defined according to the WOMAC score: minimal (> 78 points), mild (59 to 78), moderate (44 to 58), and severe (< 44). Multivariate regression analysis was used to adjust for confounding. Results. According to severity there were 1,425 patients (44.8%) with minimal, 710 (22.3%) with mild, 518 (16.3%) with moderate, and 525 (16.5%) with severe pain in the contralateral knee. Patients in the severe group had a greater clinically significant improvement in their functional WOMAC score (9.8 points; p < 0.001). Only patients in the moderate (22.9 points) and severe (37.8 points) groups had a clinically significant improvement in their contralateral knee pain (p < 0.001), but they were significantly less likely to be satisfied with their TKA (moderate: odds ratio (OR) 0.64, 95% confidence interval (CI) 0.4 to 0.92, p = 0.022; severe: OR 0.57, 95% CI 0.39 to 0.82, p = 0.002). Conclusion. Contralateral knee pain did not impair improvement in the WOMAC score after TKA, and patients with the most severe contralateral knee pain had a clinically significantly greater improvement in their functional outcome. More than half the patients presenting for TKA had mild-to-severe contralateral knee pain, most of whom had a clinically meaningful improvement but were significantly less likely to be satisfied with their TKA. Cite this article: Bone Joint J. 2020;102-B(1):125–131

Aims. The primary aim of this study was to assess whether patient satisfaction one year after total knee arthroplasty (TKA) changed with longer follow-up. The secondary aims were to identify predictors of satisfaction at one year, persistence of patient dissatisfaction, and late onset dissatisfaction in patients that were originally satisfied at one year. Patients and Methods. A retrospective cohort consisting of 1369 patients undergoing a primary TKA for osteoarthritis that had not undergone revision were identified from an established arthroplasty database. Patient demographics, comorbidities, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and Short Form 12 (SF-12) questionnaire scores were collected preoperatively, and one and five years postoperatively. In addition, patient satisfaction was assessed at one and five years postoperatively. Logistic regression analysis was used to identify independent predictors of satisfaction at one and five years. Results. The overall rate of satisfaction did not change from one (91.7%, n = 1255) to five (90.1%, n = 1234) years (p = 0.16). Approximately half (n = 53/114) of the patients who were dissatisfied at one year became satisfied with their TKA at five years, whereas 6% (n = 74/1255) of those who were satisfied at one year became dissatisfied at five years. At one year, patients with lung disease (p = 0.04), with depression (p = 0.001), with back pain (p <  0.001), undergoing unilateral TKA (p = 0.001), or with a worse preoperative WOMAC pain score (p = 0.04) were more likely to be dissatisfied. Patients with gastric ulceration (p = 0.04) and a worse WOMAC stiffness score (p = 0.047) were at increased risk of persistent dissatisfaction at five years. In contrast, a worse WOMAC pain score (p = 0.01) at one year was a predictor of dissatisfaction in previously satisfied patients at five years. Conclusion. Three groups of dissatisfied patients exist after TKA: ‘early’ dissatisfaction at one year, ‘persistent’ dissatisfaction with longer follow-up, and ‘late’ dissatisfaction developing in previously satisfied patients at one year. All three groups have different independent predictors of satisfaction, and potentially addressing risk factors specific to these groups may improve patient outcome and their satisfaction. Cite this article: Bone Joint J 2018;100-B:161–9

The periacetabular osteotomy(PAO) is an effective common hip-preserving procedure to treat symptomatic acetabular dysplasia of the hip (DDH). The literature regarding truly long-term patient outcomes after PAO remains limited. We sought to evaluate our patient cohort treated by PAO 25 to 33 years ago to identify factors positively and negatively associated with durable therapeutic success. 219 dysplastic hips (183 patients) underwent PAO between August 1991 and December 1999 by a single surgeon. 164 hips in 134 patients were retrospectively evaluated at minimum of 25 years and maximum of 33 years post-operatively. Hips were evaluated using the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) postoperatively. Osteotomy failure was defined as WOMAC pain score of >/=10 or the need for total hip arthroplasty (THA). 7 patients (7 hips) had died - none of whom had THR. 142/176 remaining patients were located. All patients returned questionnaires; some were seen in person with images. Of patients analyzed to date, 109 hips (63%) were asymptomatic/mildly symptomatic with a preserved hip. 58 hips (33%) had undergone THA. 7 preserved hips (5%) were symptomatic (WOMAC>10). Patients with THA were slightly older than asymptomatic patients (54 ± 8 years vs. 50 ± 11 years; p=0.08), as they had been at time of PAO. Most patients were female (83%), with 89% of hip replacement patients being female. 4/58 replaced hips had been revised - 3 for instability and 1 for acetabular loosening. Data collection is ongoing as more patients are located and reviewed. Long-term follow-up of patients is challenging. Review after minimum of 25 years of the Boston cohort treated with PAO after minimum of 25 years dysplasia reveals that most at long-term follow-up report high levels of function, whether or not they had required arthroplasty, although 33% had required interim treatment with THA

Pelvic osteotomies for hip dysplasia results can be variable and depend on the amount of preexisting arthritis. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a technique designed to measure early arthritis, and could be used to select hips that would benefit from a joint-preserving reconstructive procedure. Our objective was to investigate the role of preoperative dGEMRIC in predicting the success of PAO in patients 40 and above. We hypothesized that patients who failed had lower preoperative dGEMRIC index compared to those who did not. Following IRB approval, patients 40 or older who underwent PAO between 1990–2013 and had preoperative dGEMRIC scan and minimum follow-up of 4 years were identified. Patients with prior hip surgeries or any pathologies were removed leading to a total of 70 patients (Age: 44.2 ± 2.9 years old, BMI: 25.7 ± 4.5 Kg/m. 2. ). We only included the first hip undergoing PAO for those with bilateral PAO. Out of 70, 19 had failure defined by the need for total hip replacement or WOMAC pain score of 10 and above within 10 years after index PAO surgery. Articular cartilage was segmented on the 3D pre-operative dGEMRIC scan. The average thickness and dGEMRIC index across the whole articular surface were analyzed. Failed hips had a lower dGEMRIC index by 115 ± 20 ms (P<0.001). All but one failed hips had a dGMERIC index of 400 or less (range: 313 – 479 ms), while all survived hips had a dGMERIC index of greater than 400 (range: 403 – 691 ms). Similar trends were observed when comparing the dGEMRIC index within the 6 subgroups (P<0.01). There were no differences in cartilage thickness (combined femoral head and acetabular cartilage) between the failed and survived hips (p>0.2). Patients with a high dGMERIC index (indicating high GAG content) may have a higher chance of successful outcomes following PAO. Current efforts are underway to develop a multi-modal predictive model to evaluate risk of failure after PAO

High complication rates and poor outcomes have been widely reported in patients undergoing revision of large head metal-on-metal arthroplasty. A previous study from our centre showed high rates of dislocation, nerve injury, early cup loosening and pseudotumor recurrence. After noting these issues, we implemented the following changes in surgical protocol in all large head MOM revisions: One: Use of highly porous shells in all cases. Two: Use of largest femoral head possible. Three: Low threshold for use of dual mobility and constrained liners when abductors affected or absent posterior capsule. Four: Use of ceramic head with titanium sleeve in all cases. Five: Partial resection of pseudotumor adjacent to sciatic and femoral nerves. The purpose of the present study is to compare the new surgical protocol above to our previously reported early complications in this group of patients. We specifically looked at (1) complications including reoperations, (2) radiologic outcomes, and (3) functional outcomes. Complication rates after (Group 1), and before (Group 2) modified surgical protocol were compared using Chi-square test, assuming statistical significance p < 0 .05. Major complications occurred in 4 (8.3%) of 48 patients who had modified surgical technique, compared to 12 (38%) of 32 revisions prior to modification (p < 0 .05). Two hips of 48 (4.17%) endured dislocations in Group 1, compared to 9 of 32 (28%) in Group 2 (p < 0 .05). Four patients of 48 had repeat revision in Group 1: 2 for recurrence of pseudotumor, 1 for dislocation, and 1 for infection, compared to 6 patients who had 7 repeat revisions of 32 patients in Group 2: 3 for acetabular loosening, 3 for dislocation, and 1 for recurrence of pseudotumor (p=0.1). None of 48 revisions in Group 1 had acetabular loosening, compared to 4 of 32 in Group 2 (p=0.02). Two patients had nerve injury in Group 2, compared to none in Group 1 (p=0.16). The mean WOMAC pain score was 87.1 of 100 and the function score was 88.4 of 100 in Group 1, compared to a mean WOMAC pain score of 78 of 100 (p=0.6) and a function score of 83 of 100 in Group 2 (p=0.8). Modification of the surgical techniques described in the introduction has resulted in a significant decrease in complications in revision of large head MOM total hips. We continue to use this protocol and recommend it for these difficult cases

Introduction and Objective. An important subset of patients is dissatisfied after total joint arthroplasty (TJA) due to residual functional impairment. This study investigated the assessment of objectively measured step-up performance following TJA, to identify patients with poor functional improvement after surgery, and to predict residual functional impairment during early postoperative rehabilitation. Secondary, longitudinal changes of block step-up (BS) transfers were compared with functional changes of subjective patient reported outcome measures (PROMs) following TJA. Materials and Methods. Patients with end stage hip or knee osteoarthritis (n = 76, m/f = 44/32; mean age = 64.4 standard deviation 9.4 years) were measured preoperatively and 3 and 12 months postoperatively. PROMs were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function subscore. BS transfers were assessed by wearable-derived measures of time. In our cohort, subgroups were formed based on either 1) WOMAC function score or 2) BS performance, isolating the worst performing quartile (impaired) of each measure from the better performing others (non-impaired). Subgroup comparisons were performed with the Man-Whitney-U test and Wilcoxon Signed rank test resp. Responsiveness was calculated by the effect size, correlations with Pearson's correlation coefficient. A regression analysis was conducted to investigate predictors of poor functional outcome. Results. WOMAC function scores were strongly correlated to WOMAC pain scores (Pearson's r=0.67–0.84) and moderately correlated to BS performance (Pearson's r = 0.31–0.54). Prior to surgery, no significant differences for WOMAC function scores and BS performance were found between the impaired and non-impaired subgroups. One year after TJA, our cohort performed significantly better at WOMAC and BS with largest effect size for the non-impaired subgroups (0.62 and 0.43 resp.) At 12 months postop, 56% of patients allocated to the impaired subgroup defined by WOMAC, represented the impaired subgroup defined by BS. Allocation to the impaired subgroup at 3 months postop, raised the odds for belonging to the impaired subgroup at 12 months for WOMAC with an odds ratio=19.14 (67%) and for BS with an odds ratio=4.41 (42%). Conclusions. Assessment of BS performance following TJA reveals residual functional impairment that is not captured by pain-dominated PROMs. Its additional use may help to early identify those patients at risk for a poor outcome

Background. High complication rates and poor outcomes have been widely reported in patients undergoing revision of large head metal-on-metal arthroplasty. A previous study from our center showed high rates of dislocation, nerve injury, early cup loosening and pseudotumor recurrence. After noting these issues, we implemented the following changes in surgical protocol in all large head MOM revisions: 1. Use of highly porous shells in all cases 2. Use of largest femoral head possible 3. Low threshold for use of dual mobility and constrained liners when abductors affected or absent posterior capsule 4. Use of ceramic head with titanium sleeve in all cases 5. Partial resection of pseudotumor adjacent to sciatic and femoral nerves. Questions/purposes. The purpose of the present study is to compare the new surgical protocol above to our previously reported early complications in this group of patients. We specifically looked at (1) complications including reoperations; (2) radiologic outcomes; and (3) functional outcomes. Complication rates after (Group 1), and before (Group 2) modified surgical protocol were compared using Chi-square test, assuming statistical significance p<0.05. Results. Major complications occurred in 4 (8.3%) of 48 patients who had modified surgical technique, compared to 12 (38%) of 32 revisions prior to modification (p<0.05). Two hips of 48 (4.17%) endured dislocations in Group 1, compared to 9 of 32 (28%) in Group 2 (p<0.05). Four patients of 48 had repeat revision in Group 1: 2 for recurrence of pseudotumor, 1 for dislocation, and 1 for infection, compared to 6 patients who had 7 repeat revisions of 32 patients in Group 2: 3 for acetabular loosening, 3 for dislocation, and 1 for recurrence of pseudotumor (p=0.1). None of 48 revisions in Group 1 had acetabular loosening, compared to 4 of 32 in Group 2 (p=0.02). Two patients had nerve injury in Group 2, compared to none in Group 1 (p=0.16). The mean WOMAC pain score was 87.1 of 100 and the function score was 88.4 of 100 in Group 1, compared to a mean WOMAC pain score of 78 of 100 (p=0.6) and a function score of 83 of 100 in Group 2 (p=0.8). Conclusions. Modification of the surgical techniques described in the introduction has resulted in a significant decrease in complications in revision of large head MOM total hips. We continue to use this protocol and recommend it for these difficult cases. Level of Evidence. Level IV, therapeutic study

Total joint arthroplasty (TJA) is often utilized to improve pain and dysfunction associated with end-stage osteoarthritis. Previous research has suggested that depression may negatively impact patient reported pain and function. The purpose of this study was to determine the effect of pre-operative depressive symptoms, using the Center for Epidemiologic Scale for Depression (CES-D) scale, on patient reported function and pain at one, three and six months following TJA, after controlling for the impact of age, sex, pain, joint replaced, and other comorbidities. This was a secondary analysis of a prospective cohort of 710 patients aged 40 years and older who underwent elective primary TJA in the Edmonton zone. Participants were recruited pre-operatively and reported socio-demographics, comorbid conditions and medications (including depression medications where appropriate), each participant also completed the Western Ontario McMaster (WOMAC) Osteoarthritis Index and the CES-D scale preoperatively. Participants then completed the WOMAC and CES-D scale again at one, three, and six months postoperatively. Risk-adjusted longitudinal data analysis using a linear mixed regression model was performed, controlling for age, sex, joint replaced, chronic pain, comorbidity, social support and employment status. THA participants had a mean age of 65.9±10.1 years and included 175 (57%) female while TKA participants had a mean age of 67.9±10.1 years and included 249 (61%) females. ‘Possible’ depressive symptoms (CES-D score 16–19) were identified in 58 (8.1%) participants while ‘probable’ depressive symptoms (CES-D score ≥20) were identified in 68 (9.6%) participants. The mean WOMAC pain and function scores, when analyzed using the linear mixed regression model, demonstrated improvement from baseline at one, three, and six months (p < 0 .001 for both pain and function models as well as over time). However, in the patients with possible and probable depressive symptoms, WOMAC pain scores were 7.6±1.5 and 11.7±1.3 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, chronic pain, comorbidities and social support. Similarly, WOMAC function scores in the patients with possible and probable depressive symptoms were 8.8±1.4 and 14.2±1.2 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, comorbidities and employment status. Depressive symptoms negatively affect postoperative pain and function measured using WOMAC scales even after risk adjustment up to six-months post TJA. Screening for depressive symptomology both pre- and postoperatively may provide an opportunity to identify and manage depressive symptoms to improve postoperative pain and function

Total joint arthroplasty (TJA) is often utilized to improve pain and dysfunction associated with end-stage osteoarthritis. Previous research has suggested that depression may negatively impact patient reported pain and function. The purpose of this study was to determine the effect of preoperative depressive symptoms, using the Center for Epidemiologic Scale for Depression (CES-D) scale, on patient reported function and pain at one, three and six months following TJA, after controlling for the impact of age, sex, pain, joint replaced, and other comorbidities. This was a secondary analysis of a prospective cohort of 710 patients aged 40 years and older who underwent elective primary TJA in the Edmonton zone. Participants were recruited pre-operatively and reported socio-demographics, comorbid conditions and medications (including depression medications where appropriate), each participant also completed the Western Ontario McMaster (WOMAC) Osteoarthritis Index and the CES-D scale preoperatively. Participants then completed the WOMAC and CES-D scale again at one, three, and six months postoperatively. Risk-adjusted longitudinal data analysis using a linear mixed regression model was performed, controlling for age, sex, joint replaced, chronic pain, comorbidity, social support and employment status. THA participants had a mean age of 65.9±10.1 years and included 175 (57%) female while TKA participants had a mean age of 67.9±10.1 years and included 249 (61%) females. ‘Possible’ depressive symptoms (CES-D score 16–19) were identified in 58 (8.1%) participants while ‘probable’ depressive symptoms (CES-D score ≥20) were identified in 68 (9.6%) participants. The mean WOMAC pain and function scores, when analyzed using the linear mixed regression model, demonstrated improvement from baseline at one, three, and six months (p < 0 .001 for both pain and function models as well as over time). However, in the patients with possible and probable depressive symptoms, WOMAC pain scores were 7.6±1.5 and 11.7±1.3 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, chronic pain, comorbidities and social support. Similarly, WOMAC function scores in the patients with possible and probable depressive symptoms were 8.8±1.4 and 14.2±1.2 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, comorbidities and employment status. Depressive symptoms negatively affect postoperative pain and function measured using WOMAC scales even after risk adjustment up to six-months post TJA. Screening for depressive symptomology both pre- and postoperatively may provide an opportunity to identify and manage depressive symptoms to improve postoperative pain and function

This study compared the demographic, clinical and patient-reported outcomes after total hip replacement (THR) and Birmingham Hip Resurfacing (BHR) carried out by a single surgeon. Patients completed a questionnaire that included the WOMAC, SF-36 scores and comorbid medical conditions. Data were collected before operation and one year after. The outcome scores were adjusted for age, gender, comorbid conditions and, at one year, for the pre-operative scores. There were 214 patients with a THR and 132 with a BHR. Patients with a BHR were significantly younger (49 vs 67 years, p < 0.0001), more likely to be male (68% vs 42% of THR, p < 0.0001) and had fewer comorbid conditions (1.3 vs 2.0, p < 0.0001). Before operation there was no difference in WOMAC and SF-36 scores, except for function, in which patients awaiting THR were worse than those awaiting a BHR. At one year patients with a BHR reported significantly better WOMAC pain scores (p = 0.04) and in all SF-36 domains (p < 0.05). Patients undergoing BHR report a significantly greater improvement in general health compared with those with a THR

A prospective cohort of 222 patients who underwent revision hip replacement between April 2001 and March 2004 was evaluated to determine predictors of function, pain and activity level between one and two years post-operatively, and to define quality of life outcomes using validated patient reported outcome tools. Predictive models were developed and proportional odds regression analyses were performed to identify factors that predict quality of life outcomes at one and two years post-operatively. The dependent outcome variables were the Western Ontario and McMaster Osteoarthritis Index (WOMAC) function and pain scores, and University of California Los Angeles activity scores. The independent variables included patient demographics, operative factors, and objective quality of life parameters, including pre-operative WOMAC, and the Short Form-12 mental component score. There was a significant improvement (t-test, p < 0.001) in all patient quality of life scores. In the predictive model, factors predictive of improved function (original regression analyses, p < 0.05) included a higher pre-operative WOMAC function score (p < 0.001), age between 60 and 70 years (p < 0.037), male gender (p = 0.017), lower Charnley class (p < 0.001) and aseptic loosening being the indication for revision (p < 0.003). Using the WOMAC pain score as an outcome variable, factors predictive of improvement included the pre-operative WOMAC function score (p = 0.001), age between 60 and 70 years (p = 0.004), male gender (p = 0.005), lower Charnley class (p = 0.001) and no previous revision procedure (p = 0.023). The pre-operative WOMAC function score (p = 0.001), the indication for the operation (p = 0.007), and the operating surgeon (p = 0.008) were significant predictors of the activity assessment at follow-up. Predictors of quality of life outcomes after revision hip replacement were established. Although some patient-specific and surgery-specific variables were important, age, gender, Charnley class and pre-operative WOMAC function score had the most robust associations with outcome

Introduction:. Unicompartmental knee arthroplasty (UKA) has been proven to be an effective treatment for degenerative joint disease confined to a single tibiofemoral compartment. Recently, UKAs have been performed with robotic-arm assistance (RAA) devices to build and improve upon previous computer-assisted navigation. As a pilot study, we have analyzed short term outcomes for a series of robotic-arm assisted medial UKAs and compared them to a comparable cohort of traditionally instrumented medial UKAs. Methods:. Ninety-eight fixed-bearing medial UKAs were isolated in our prospective data collection database for short-term analysis for this study. Included patients completed pre and post-operative Short Form 12 version 1 Health Survey (SF12), Western Ontario and McMaster University Outcome Scores (WOMAC), and Knee Society Function Score (KSFS) questionnaires. Forty-eight RAA UKAs were performed using the MAKO RIO system with Restoris implants, and fifty manual UKAs were performed with the Zimmer® Unicompartmental High-Flex Knee System (ZUK). Results:. Both cohorts experienced increased gains in all categories, except for the change in SF12 mental subscore in the MAKO cohort. Only the WOMAC pain subscore at 1 year showed statistically significant differences between the two cohorts, with MAKO subjects experiencing less pain than ZUK subjects (92.4 MAKO vs. 82.0 ZUK, p = 0.03). The SF12 mental score at three months and the change in SF12 mental score from pre-op to 1 year were also statistically significant; however, the pre-op differences between the two groups in the SF 12 mental category were also significantly different. Within the groups that were not significantly different, ZUK subjects experienced greater changes from pre-operative to three months in SF12 mental, all WOMAC subsets, and KSFS, while MAKO subjects had a greater change in SF12 physical subscore. This pattern held true with changes between pre-operative and 1 year, with the exception that MAKO patients experienced a greater positive change in WOMAC pain scores than ZUK patients. Additionally, age and body mass index were not significantly different between cohorts; however, operative time was significantly longer in the MAKO cohort (p < 0.001). Discussion:. These results suggest that despite the lower WOMAC pain scores at one year, the extra expense and operative time required for RAA UKA may not translate into immediate functional gains. These conclusions are however limited due to the short follow-up time period and the randomization of patients. Future studies must also analyze implant alignment, rotation and position in order to fully analyze the operations

Purpose: Obesity is known to be a risk factor for the incidence and progression of prevalent osteoarthritis (OA). The relationship is traditionally believed to be a mechanical effect on weight bearing joints such as the hip and knee, however studies showing a relationship between body mass index (BMI) and OA of non-weight bearing joints, such as the hand, suggest another theory. They suggest that the relationship between obesity and joint degeneration may be a systemic metabolic effect whereby visceral and sub-cutaneous truncal white adipose tissue (WAT) secrete inflammatory mediators that directly influence the pathogenesis of OA. We asked what is the relationship between adiponectin, leptin, and the A/L ratio and patient reported pain in an end stage knee OA joint population. Method: We collected demographic data, Short Form McGill Pain scores, WOMAC pain scores, and synovial fluid (SF) samples from 60 consecutive patients with severe knee OA at the time of joint replacement surgery. Synovial fluid samples were analyzed for leptin and adiponectin using specific ELISA. Non-parametric correlations and linear regression modeling were used to identify the relationship between the adipokines and pain levels. Results: The correlations between the individual adipokines and the pain scales were consistently less than that for the corresponding adipokine ratio. The A/L ratio correlated moderately with the MPQ-SF, (r(58) = − 0.46, p < .01) and the WOMAC pain score, (r(58) = − 0.38, p > .01). Linear regression modeling demonstrated that the A/L ratio was a significant predictor of a greater level of pain on the MPQ-SF(p=0.03, Table 3) but not the WOMAC pain scale(p=0.77, Table 4). Models were adjusted for age, gender, BMI, and medical comorbidity. Conclusion: In conclusion, a greater A/L ratio predicted lower knee OA pain as measured by the MPQ-SF, but not on the WOMAC pain scale. This finding was above that of the individual adipokine levels alone. Some authors have suggested that leptin may have a proin-flammatory role while adiponectin an anti-inflammatory role in synovial joint diseases. Further work to elucidate these pathways may present a target for novel therapeutics in knee OA

Objective. To evaluate the clinical and functional outcomes obtained by combination of high-flexion Freedom® Total Knee System (TKS) and mini-subvastus approach in total knee replacement patients. Method. This is a retrospective, observational, real world study conducted at Mumbai in India from 2011 to 2016. All patients who were above the age of 18 and operated for total knee replacement (TKR) with mini-subvastus approach using Freedom (Maxx Medical) by the senior author were included. The Implant survivorship was the survey endpoint; primary endpoint was range of motion (ROM); and secondary endpoints were AKSS (American Knee Society Score) and WOMAC (Western Ontario and McMaster Universities Osteoarthritis) scores collected pre- and post-operatively. Results. 184 patients with 242 knees (126 unilateral and 58 bilateral) were operated with high-flexion TKS. Average age of patients was 70 ± 6.2 years. The mean ROM increased from 99.4°±10.44° (50°-120°) preoperatively to 116.78°±8.18° (88°–140°) postoperatively (p<0.001). Clinical and functional AKSS scores improved from 60.83±5.12 to 91.16±2.19 (p<0.001) and 65.35±3.52 to 99.13±4.61 (p<0.001) respectively. There average WOMAC pain scores improved from 12.12±1.72 to 0.066±0.37 (<0.0001). Moreover, post-operative WOMAC stiffness and function scores depicted significant improvement from 4.43±0.97 to 0.03±0.26 (p<0.0001) and 0.03±0.26 to 0.18±1.21 (p<0.0001) respectively at a mean follow-up of 3.71 ± 0.98 years. Implant survivorship was 100%. Conclusion. High-flexion Freedom® TKS demonstrated a satisfactory clinical and functional improvements including high flexion when operated by the mini-subvastus approach at a mean FU of 4 years

Aims

Despite new technologies for total knee arthroplasty (TKA), approximately 20% of patients are dissatisfied. A major reason for dissatisfaction and revision surgery after TKA is persistent pain. The radiological grade of osteoarthritis (OA) preoperatively has been investigated as a predictor of the outcome after TKA, with conflicting results. The aim of this study was to determine if there is a difference in the intensity of pain 12 months after TKA in relation to the preoperative radiological grade of OA alone, and the combination of the intensity of preoperative pain and radiological grade of OA.

The aim of this study was to determine the outcomes and survivorship of the Triathlon knee replacement at 7 years after surgery. A cohort of 266 patients receiving a Triathlon knee replacement were assessed before surgery and at 3 months, 1 year, 2 years, 3 years, 5 years and 7 years post-operation. Patient-reported outcomes were assessed using the WOMAC, KOOS Knee-Related Quality of Life scale, Satisfaction Scale and questions on kneeling ability and whether they regretted having the operation. Data on survivorship was collected from self-report and medical records. At 7 years after surgery, 32 patients were deceased, and 17 patients were withdrawn. Of the 217 patients remaining in the study, 164 (76%) returned a completed study questionnaire. At 7 years after surgery, 92% of patients reported an improvement in their WOMAC Pain score greater than the minimally clinically important improvement (defined as improvement of ≥9 points from before surgery) and 82% reported this in their WOMAC Function score (defined as improvement of ≥12 points). Knee-related quality of life was good, with a mean score of 66.8 (SD 26.0) (0–100 scale, worst to best). A high percentage of patients (89%) were somewhat or very satisfied with their outcome at 7 years. Survivorship with revision as the endpoint was 96.4% (95% CI 93.2–98.1%) at 7 years post-operation. Five percent of patients regretted having their operation and 68% reported much difficulty or an inability to kneel. In conclusion, this study observed good long-term patient outcomes and survivorship of the Triathlon knee replacement

INTRODUCTION. To test whether there are differences in postoperative mechanical and component alignment, and in functional results, between conventional, navigated and patient-specific total knee arthroplasties in a low-volume centre?. MATERIAL AND METHODS. Retrospective cohort study of 391 patients who received conventional, navigated or patient- specific primary cemented TKA in a low-volume hospital. RESULTS. The risk of mechanical alignment outliers was 89% lower in the navigated group compared to the conventional TKA group. There was a 63% lower risk of femoral component malalignment and a 66% lower risk of tibial component malalignment in the navigated group. No significant reduction in the risk of malalignment was seen in the patient-specific group. Total WOMAC and Oxford scores were no different between the three techniques. The patient-specific group reported better WOMAC pain scores. PSI TKA was 33% more expensive than conventional TKA and 28% more expensive than Navigated TKA. DISCUSSION. Navigated TKA improved alignment, but neither navigated nor patient-specific TKA improved functional outcomes. Patient-specific TKA was more expensive, with little additional benefit. Clinical relevance: The routine use of patient-specific instrumentation in low-volume centers is not supported by the currently available data

Background: Clinical studies of Collagen Hydrolysate have suggested efficacy in decreasing symptoms and increasing joint function. Therefore a large multi-center, randomized, double-blind, placebo-controlled trial including 389 patients with osteoarthritis (OA) of the knee was performed with 6 centers in the United States (US), 3 in the United Kingdom (UK) and 11 in Germany (GER). Patients randomly received either identically packaged 10g Pharmaceutical Collagen Hydrolysate (PCH) or 12g lactose (placebo) for 24 weeks. Centers were used as strata for randomization. Acetaminophen (ACET) rescue up to 4g/day was allowed. Primary efficacy parameters were the differences of the WOMAC pain score, the WOMAC physical function score and the Patient Global Evaluation that were measured at the beginning and the end of the study period. No statistically significant differences between treatment groups were observed for the total study population. However, when individual countries were analyzed, a statistically significant treatment advantage of PCH over placebo was observed in all 3 primary efficacy endpoints in Germany (adjusted p-value < 0.05), but neither in the US nor the UK. Purpose: To analyse country differences of the 3 primary endpoints using univariate and multivariate statistical methods. Methods: Since the randomization was done within the centers, the randomization is still valid for a by country analysis. Firstly, the success of the randomization was investigated. Secondly, the influences of certain factors on the effect of the treatment were exploratorily analyzed for each primary efficacy endpoint by a univariate analysis. Thirdly, a multivariate linear regression analysis (for the two continuous primary efficacy endpoints WOMAC pain score and WOMAC physical function score) or a logistic regression (for the discrete primary efficacy endpoint Patient Global Evaluation) was performed. Results: Randomization – No differences of age, gender, and race were determined between the treatment groups in all countries. Univariate analysis – Effects of the placebo, drop-out rate, protocol violations, ACET consumption, and baseline differences in all primary efficacy endpoints show significant differences between Germany and the USA. Multivariate analysis – The drop-out rate was the prognostic factors with the highest effect for all primary efficacy endpoints. Furthermore treatment, country, baseline differences, and ACET intake were also significant prognostic factors. Conclusions:. Although a unique study protocol for all countries was used, the outcomes of PCH compared to placebo were different between the three countries. In multi-national studies strategies for controlling possible cultural influences have to be developed. Results of studies carried out in one country should only be cautiously transferred into another country

Introduction. Deaths due to overdose involving opioids have nearly quadrupled in USA in the last 20 years. Several published studies have shown that preoperative opioid use independently predicts perioperative complications in total joint arthroplasty. Our objectives were to (1) assess preoperative opioid consumption in patients undergoing total hip arthroplasty (THA) and (2) to determine how preoperative opioid use affects patient oriented outcomes (POO's) and hip scores before and after THA. Methods. 54 primary THA by a single surgeon were reviewed. A new patient questionnaire was administered to document preoperative opioid consumption (type, dosage and length of use); preoperatively and postoperatively POO's measurements [visual analog scale (VAS), QWB-7, SF-36, and WOMAC] and hip scores were recorded. Patients were stratified into two groups: (1) Opioid Users and (2) Non-Opioid Users. Oral morphine equivalents (OME) were calculated for opioid using patients using standard methodology. Results. 22.2% of the patients were using opioids prior to THA. Among these, 16.6% had tried more than 1 drug. Dosage was self-reported in 33.3% and length of usage only in 8.3%. Mean OME was 13.3mg (range: 6mg–32mg) among users. After adjusting for covariates (gender), opioid users reported worse significant outcomes before surgery for the SF-36 general health (69 vs 80.7; p=0.02), SF-36 role emotional (75.7 vs 99.1; p=0.002), and SF-36 mental health (64 vs 79.7; p=0.005). After surgery even though significant improvements were seen in both groups, opioid users reported significantly worse WOMAC pain scores (1.4 vs 0.3; p=0.03) than non-opioid users. Conclusions. Almost a quarter of the patients in our community undergoing THA, use opioid medications prior to surgery. Opioid users came to surgery with more pain and less function and had worse outcomes. Documentation on the use of opioids in self-administered questionnaire was poor at best. Quantification of OME may help the surgeons with a cutoff point for referral to detoxification before surgery. A significant effort needs to be made in order to measure and manage opioids prior to THA

Aims

The aim was to assess whether robotic-assisted total knee arthroplasty (rTKA) had greater knee-specific outcomes, improved fulfilment of expectations, health-related quality of life (HRQoL), and patient satisfaction when compared with manual TKA (mTKA).

Background. Total knee replacement (TKR) is an effective operation for many patients, however approximately 20% of patients experience chronic pain and functional limitations in the months and years following their TKR. If modifiable pre-operative risk factors could be identified, this would allow patients to be targeted with individualised care to optimise these factors prior to surgery and potentially improve outcomes. Psychosocial factors have also been found to be important in predicting outcomes in the first 12 months after TKR, however their impact on long-term outcomes is unknown. This study aimed to identify pre-operative psychosocial predictors of patient-reported and clinician-assessed outcomes at one year and five years after primary TKR. Patients and methods. 266 patients listed for a Triathlon TKR because of osteoarthritis were recruited from pre-operative assessment clinics at one orthopaedic centre. Knee pain and function were assessed pre-operatively and at one and five years post-operative using the WOMAC Pain score, WOMAC Function score and American Knee Society Score (AKSS) Knee score. Pre-operative depression, anxiety, catastrophizing, pain self-efficacy and social support were assessed using patient-reported outcome measures. Statistical analyses were conducted using multiple linear regression and mixed effect linear regression, and adjusted for confounding variables. Results. Higher anxiety was a predictor of worse self-reported pain at one year post-operative. Higher anxiety and catastrophizing were predictive of worse self-reported function at one year post-operative. No psychosocial factors were associated with any outcome measures at five years post-operative. Analysis of change over time found that patients with higher pain self-efficacy had lower pre-operative pain and experienced less improvement in pain up to one year. Higher pain self-efficacy was associated with less improvement in the AKSS up to one year post-operative but more improvement between one and five years post-operative. Conclusion. This study found that pre-operative anxiety and catastrophizing influence outcomes at one year after TKR, highlighting that some patients may benefit from targeted psychological interventions to reduce these risk factors and improve outcomes. However, none of the psychosocial variables assessed were predictors of outcomes at five years post-operative, suggesting that the negative effects of anxiety and catastrophizing on outcome do not persist in the longer term

Cam-type femoral acetabular impingement (FAI), is a common structural hip deformity and thought to be a leading cause of early hip osteoarthritis. Although patients who undergo surgical correction notice improved clinical function it is unclear what impact this has on the overall health of the cartilage. T1rho MRI cartilage mapping has been shown to be a reliable imaging technique to assess the proteoglycan (PG) content potentially serving as a biomarker. This study analyses post surgical changes in T1rho levels in hip joints treated with cam FAI. Eleven patients with a mean age of 38 (all males) underwent pre and post T1Rho Cartilage mapping of their hips at a mean time of 20 months post surgical intervention. The acetabulum was spatially divided into 4 main regions of interest (ROI), with levels of T1Rho in cartilage quantified as a whole and in each spatial segment. T1Rho signal is inversely correlated with level of PG content. All patients demonstrated loss of PG content on pre-op imaging with a T1Rho of 33.5ms+2.6ms. Preop T1rho levels were found to significantly correlated with the difference between pre-op and post-op T1rho in entire hip cartilage (R: 0.73; p=0.016). This correlation was reflected both in the anterolateral quadrant (R: 0.86; p=0.002), and in the posteriosuperior quadrant (R:0.70; p=0.035). Additionally, significant correlation was found between improvement of WOMAC pain score over time, and difference of T1rho values over time in the most lateral 3mm slice of the anterolateral quadrant (R: 0.81; p=0.045). Significant correlation was found between pre-op alpha angle at 1:30 and difference between pre-op and post-op total cartilage T1rho content (R: −065;p=0.038). T1Rho Cartilage mapping of the hip is a useful biomarker in the assessment of the surgical management of Cam type FAI. This preliminary data provides some evidence that surgical correction of the deformity can help minimise disease progression

Purpose. Periacetabular osteotomy (PAO) is a versatile acetabular reorienting procedure that is most commonly used to provide greater femoral head coverage in adolescent hip dysplasia. However, PAO can also be used to reorient the acetabulum in the opposite direction to treat femoroacetabular impingement (FAI) due to acetabular over-coverage. We describe the indications, surgical technique, and early results of reverse PAO to reduce femoral head coverage in symptomatic hips with FAI due to acetabular over-coverage. Methods. IRB approval was obtained to retrospectively review cases of symptomatic acetabular over-coverage treated with reverse PAO and that had a minimum of two years follow-up. All hips had atypical intraoperative positioning of the acetabular fragment to uncover the lateral and anterior aspects of the femoral head, with or without anteverting the acetabulum. Prospectively collected pre- and post-operative demographics, WOMAC scores, Modified Harris Hip Score (MHHS), and radiographic measurements consisting of the lateral center edge angle (LCEA), Tönnis angle (TA), and anterior center edge angle (ACEA) were compared using student's t-test. Results. Between 2004 and 2015, 31 hips (18 left, 13 right) in 26 patients (18 female, 8 male) met the inclusion criteria. Average age at the time of surgery was 19.4 years. Average length of follow-up was 30.4 months. After reverse PAO, femoral head coverage significantly decreased (LCEA 41.7° to 35.3°, p<.001; TA −7.4° to −3.7°, p<.01; ACEA 44.0° to 35.3°, p<.0001). Patients experienced improved post-operative pain, with decreases in WOMAC pain score (from 8.8 to 4.2, p<.001) and WOMAC stiffness score (from 3.5 to 1.9, p<.001). Patients also experienced improvements in function and quality of life with improvements in WOMAC function score (from 24.8 to 10.0, p<.001) and MHHS (from 60.8 to 83.2, p<.0001). Conclusion. Reverse PAO is a technically challenging procedure that provides clinical and radiographic improvement in patients with symptomatic FAI due to acetabular over-coverage. Significance. Reverse PAO is an especially useful and appropriate alternative to arthroscopic acetabular rim-trim in complex FAI pathomorphologies

18 Patients with SCD and 2ndry Osteoarthritis of their hips due to Avascular Necrosis underwent uncemented THA. There were 12 male and 6 female patients. Patient had their pre op WOMAC/SF-36/HOOS/and Oxford hip scores recorded preoperatively a well as 3 month, 6months and one year post op. The outcome scores at one year were significantly better than the pre operative scores. However, when compared to a matched cohort of patients who underwent THA for reasons other than SCD/AVN, e.g. primary OA, rheumatoid arthritis, post traumatic OA, the WOMAC pain score improvement was less

When performing total knee replacement (TKR), surgeons must select a size of tibial component tray that most closely matches the anatomy of the proximal tibia. As implants are available in a limited range of sizes, it may be necessary to slightly under or oversize the component. There are concerns overhang could lead to pain from irritation of soft tissues, and underhang could lead to subsidence and failure. 154 TKRs at 1- or 5-year follow up were reviewed prospectively. Oxford Knee Score (OKS), WOMAC and SF-12 was recorded along with pain scores. Scaled radiographs were reviewed and grouped into perfect sizing (78 TKRs, 50.6%), underhang in isolation (48 TKRs, 31.1%), minor overhang 1–3 mm (10 TKRs, 6.49%) or major overhang >3 mm (18 TKRs, 11.7%). There was no significant difference in the SF-12 (p=0.356), post-operative OKS (p=0.401) or WOMAC (p=0.466) score. For the OKS, there was no difference for the scores collected at 1 year (p=0.176) or at 5 years (p=0.883). Pre-operative OKS was well matched between the groups (p=0.152). There was no significant difference in the improvement in OKS from pre-operative scores (p=0.662). There was no significant difference in either the OKS or WOMAC pain scores (p=0.237 and 0.542 respectively). There was no significant association of medial overhang with?medial knee pain (p=1.000) or lateral overhang with lateral knee pain (p=0.569) when compared to the group of patients with a well sized tibial component. Our results suggest that tibial component overhang or underhang has no detrimental affect on outcome or pain scores. Surgeons should continue to select the tibial component that most closely fits the rim of the proximal tibia while accepting slight overhang if necessary due to the potential longer-term complications of subsidence and premature failure with an undersized tibial tray

Introduction. In Total Hip Arthroplasty (THA), polyethylene wear reduction is key to implant longevity. Oxidized Zirconium (OxZi) unites properties of a ceramic bearing surface and metal head, producing less wear in comparison to standard Cobalt-Chromium (CoCr) when articulating with Cross-linked polyethylene (XLPE) in vitro. This study investigates in vivo polyethylene (PE) wear, outcomes and complications for these two bearing couples in patients at 5 year follow-up. Methods. 400 patients undergoing THA across four institutions were prospectively randomised into three groups. Group I received a cobalt-chrome (CoCr) femoral head/ cross-linked polyethylene (XLPE) liner; Group II received an OxZi femoral head/ ultrahigh molecular weight polyethylene (UHMWPE) liner; Group III received an OxZi femoral head/XLPE liner. All bearing heads were 32 mm. Linear wear rate was calculated with Martell computer software. Functional outcome and complications were recorded. Results. At median follow-up of 3.7 years, implant survivorship was 98% across all groups with no difference in SF-36, WOMAC, pain score or complications (p > 0.05). After the first 12 months of creep, rate of linear wear over 3 years was 0.07 mm for Group I, 0.16 mm for Group II, and 0.03 mm/year for Group III. A significant difference was detected when using UHMWPE (p = 0.012) but not when using XLPE (P = 0.75). Conclusion. At midterm follow-up, an XLPE acetabular liner is more important in reducing wear than the femoral head bearing. There is a trend towards lower wear when coupling OxZi rather than CoCr with XLPE; further long-term analysis is recommended to observe this pattern

Comprehensive anthropometric information is essential to avoid patella-related complications after TKA. We compared the anthropometric patellar dimensions of Korean and Western patients. In particular, we determined whether the reestablishment of original patellar thickness, residual bony thickness, and pre- to postoperative deviations between the median ridge position and the component center position influence the clinical and radiographic outcomes of TKAs. We measured anthropometric patellar dimensions in 752 osteoarthritic knees treated with TKA in 466 Korean patients and compared them with those of Western patients reported in the literature. We investigated the effects of postoperative overall thickness deviations, residual bony thickness after bone resection, and postoperative deviations of component center positions from median ridge positions versus clinical and radiographic outcomes evaluated 1 year after surgery. Korean patients undergoing TKA had thinner and smaller patellae than Western patients. We found no associations between pre- to postoperative overall thickness differences and clinical and radiographic outcomes and no differences between knees with a residual bony thickness of 12 mm or more and knees with a residual thickness of less than 12 mm, with the exception of WOMAC pain scores. We found no associations between postoperative deviations of component center position and clinical or radiographic outcomes. Our findings indicate bone resection for patellar resurfacing can be flexible without jeopardizing clinical outcome

The purpose of this study is to evaluate the effect of prosthetic patellar resurfacing on outcome of revision total knee arthroplasty in a matched cohort study. From January 1997 to December 1999 126 patients who underwent revision of total knee arthroplasty were identified. The status of the patella was ascertained post revision as to the presence or absence of patellar prosthesis. At a minimum of two years follow-up, pain and function were assessed by questionnaire for WOMAC, Oxford-12, SF-12 and patient satisfaction data. Co-morbidity, surgical exposure, HSS knee scores and ROM were also collected. Univariate and multivariate analysis were performed. Follow-up was obtained in 110 patients (52 with patellar component, 58 bony shell), matched for age (mean 70 and 67 years), sex and co-morbidity scores and followed for a minimum of two years. There was no significant difference between the two cohorts with regards to outcomes of WOMAC pain scores (mean 66 and 74, p=0.14), WOMAC function scores (mean 59 and 65, p=0.22), Oxford- 12 scores (mean 57 and 64, p=0.17), and satisfaction score outcomes (57 and 68, p=0.14). It remains controversial whether the patient’s pain, function and satisfaction are affected in revision total knee arthroplasty by patellar prosthetic resurfacing. Insufficient patellar bone stock may preclude prosthetic resurfacing in which case patel-loplasty is performed. From this series, the presence or absence of a patellar prosthesis does not appear to sig-nificantly affect pain, function, or satisfaction outcomes following revision total knee arthroplasty

Introduction:. Total hip arthroplasty (THA) is extremely effective in treating debilitating arthritic conditions of the hip. With the many modular prosthetic designs available, surgeons can now precisely construct mechanical parameters such as femoral offset (FO). Although several studies have investigated relationships between offset choice and hip abductor strength, hip range of motion, and prosthetic wear rate, there is scarce data on the effect of FO on pain and functional outcomes following THA. The objective of this study was to assess the effect of restoring FO (within varying degrees compared to the contralateral non-diseased hip [CL]) on physical function, mental well-being, pain, and stiffness outcomes as measured by the Short Form 12 Health Survey (SF-12) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) at post-operative follow-up. Methods:. We prospectively collected data on 249 patients that underwent unilateral THA with no or minimal disease of the contralateral hip. Baseline data collection included: age, gender, diagnosis, femoral head size, type of stem, and pre-operative SF-12 and WOMAC scores. Post-operative SF-12 and WOMAC scores were recorded during annual follow-up visits. Post-operative FO was retrospectively measured on standard anteroposterior (AP) pelvis radiographs and compared to FO of CL. FO was measured as the perpendicular distance from the femoral head center of rotation to the anatomic axis of the femur with appropriate adjustments made for image magnification. Patients were categorized into one of three groups: decreased femoral offset (dFO, less than −5 mm compared to CL), normal femoral offset (nFO, between −5 and +5 mm of CL), and increased femoral offset (iFO, greater than +5 mm compared to CL). Results:. In all, 31 patients were categorized into dFO, 163 categorized into nFO, and 55 categorized into iFO. At baseline, the groups differed in categorical diagnoses (p = 0.01). Further analysis revealed a higher percentage of posttraumatic arthritis in dFO as compared to nFO and iFO (12.9%, 1.2%, and 1.8%, respectively). Moreover, a higher percentage of hip dysplasia was present in iFO as compared to nFO and dFO (14.5%, 3.6%, and 6.5%, respectively). Pre-operatively, dFO had lower WOMAC Pain scores than nFO and iFO (29.68, 43.39, and 43.63, respectively; p < 0.005). (Please see Table 1 for comparison of baseline characteristics between groups.) All other pre-operative demographic and survey characteristics were similar. At most recent post-operative follow-up, dFO had lower WOMAC Physical Function scores than nFO and iFO (72.03, 83.23, and 79.51, respectively; p < 0.02) (see Table 2). Discussion:. Reduction of patients' native FOs by greater than 5 mm during THA can lead to inferior levels of physical function. Furthermore, increasing FO by greater than 5 mm did not lead to increased levels of pain nor decreased levels of function

Introduction: In the United Kingdom, the wait for hip or knee joint replacement surgery can be particularly long. There are conflicting research accounts whether debilitating symptoms, such as pain and the effects on physical function and quality of life deteriorate or remain the same in individuals who are on the waiting list for hip or knee joint replacement. This study was conducted to investigate the severity of pain, level of physical function and quality of life amongst adults with osteoarthritis awaiting hip or knee joint replacement. Methods: A longitudinal study was undertaken in the North West of England during 2003–2005. A total of 105 patients listed for primary hip or knee joint replacement were recruited, interviewed at baseline, and followed-up at three, six and nine months, or until their joint replacement. Measurement tools used were a visual analogue scale (VAS), Western Ontario McMaster’s University (WOMAC) Osteoarthritis Index and the Medical Outcomes Study Short Form Health Survey (SF-36). Results: High levels of pain and poor physical function and quality of life were experienced by patients on the waiting list for joint replacement. At the three month follow-up (n=84) changes in VAS pain scores (0.6; 95% CIs mean difference 0.3,1.0); WOMAC pain scores (1.2 (95% CIs mean difference 0.7, 1.8) and WOMAC physical function scores (4.8; 95% CIs mean difference 2.8, 6.7) were significantly worse compared to baseline. However, there were minimal changes in quality of life as measured by the SF-36 while on the waiting list. Discussion: The often long wait for joint replacement surgery and deterioration in pain and physical function has highlighted the need for active management by health professionals while patients are on the waiting list. There needs to be a clinical reassessment of patients by health professionals while on the waiting list for joint replacement

Introduction. Osteoarthritis (OA) represents a leading cause of disability and a growing burden on healthcare budgets. OA is particularly vexing for young, active patients who have failed less invasive therapies but are not yet candidates for arthroplasty. Often, patients suffering in this wide therapeutic gap face a debilitating spiral of disease progression, increasing pain, and decreasing activity until they become suitable arthroplasty patients. An implantable load absorber was evaluated for the treatment of medial knee OA in this patient population. Joint overload has been cited as a contributor to OA onset or progression. In response, the KineSpring® System (Moximed, Inc, USA) has been designed to reduce the load acting on the knee. The absorber is implanted in the subcutaneous tissue without violating the joint capsule, thus preserving the option of future arthroplasty. The implant is particularly useful for young, active patients, given the reversibility of the procedure and the preservation of normal flexibility and range of motion. Methods and Results. The KineSpring System was implanted in 55 patients, with the longest duration exceeding two years. The treated group had medial knee OA, included younger OA sufferers (range 31–68 years), with a mean BMI > 30kg/m2. Acute implant success, adverse events, and clinical outcomes using validated patient reported outcomes tools were recorded at baseline, post-op, 2 and 6 weeks, and 3, 6, 12 and 24 months post-op. All patients were successfully implanted with a mean procedure time of 76.4 min (range 54–153 minutes). Mean hospital length of stay was 1.7 days (range 1–3 days), and patients recovered rapidly, achieving full weight bearing within 1–2 wks and normal range of motion by 6 weeks. Most patients experienced pain relief and functional improvement with 85% (35/41) reporting none or mild pain on the WOMAC pain subscale and 90% (37/41) reporting functional impairment as none on mild on the WOMAC function subscale at the latest follow-up visit (mean 9.3 ± 3.5 months). Clinically meaningful and statistically significant pain reduction and functional improvement were noted with baseline WOMAC pain scores (0–100 scale) improving from 42.4 to 16.1 (p<0.001) and WOMAC function (0–100 scale) improving from 42.0 to 14.7 (p<0.001) at latest follow-up. Patients reported satisfaction with the implant and its appearance. Conclusions. The KineSpring System preserves natural knee anatomy and kinematics while providing pain reduction and resumption of high activity levels that have proven durable. This device, with these excellent results, fills a major gap in treatment options for young and active OA patients

Purpose: The purpose of this study was to compare postoperative quality of life in patients with dysplasia who underwent Bernese periacetabular osteotomy to those who had total hip arthroplasty. Methods: Patients were included who had a diagnosis of dysplasia and were greater than 40 years old. Cases were patients who had a periacetabular osteotomy. Controls were patients who had undergone total hip arthroplasty. Patients were matched for gender, age, and comorbidity. There were 26 cases and 33 controls. Outcome tools were the Western Ontario McMaster Universities (WOMAC) osteoarthritis index, the SF-12, and the Arthroplasty Satisfaction Scale. T-tests were used to compare means between the groups. The chi-squared test was used to compare the percentage of patients who had very good, good, or poor outcomes between the groups. WOMAC scores were normalized on a 0–100 scale with 0 being worst and 100 being best. A WOMAC score > 75 was considered very good, 65–75 good, and below 65 poor. Results: The mean follow-up was just over 4 years in both groups. There was a clinically and statistically significant difference in WOMAC pain and function scores favouring the total hip patients. Mean WOMAC pain scores were 89 vs 71 (p< 0.0050). Mean WOMAC function scores were 91 vs74 (p< 0.005). Ninety-seven percent of total hip patients had a good or very good result vesus 73% of the osteotomy patients (p< 0.05). Conclusions: Total hip arthroplasty gives a more consistent and better return of quality of life in patients over 40 when measured at a mean of 4 years after operation. Future research should be directed toward preoperative and intraoperative factors that could improve the outcome of patients having an osteotomy in this age group

Introduction:. Recently there has been interest in an alternative method of aligning a total knee arthroplasty (TKA) referred to as kinematic alignment. The theoretical appeal of this method is that alignment of each patient's knee can be individualized through the use of preoperative imaging and computer software, with the goal of achieving pre-arthritic alignment through restoration of the axes of rotation of each particular knee. Clinical studies have evaluated the outcomes of this new alignment technique, but to date there have been no randomized controlled trials comparing kinematic alignment to mechanical alignment. This randomized controlled trial was conducted to compare kinematically aligned and mechanically aligned TKA outcomes of knee pain, function and motion at two years' post-op, along with a comparison of limb, knee, and implant alignment of the two methods. Methods and Materials:. Forty-four patients were surgically treated with kinematically aligned TKA (figure 1) with the use of patient specific guides, and forty-four patients were surgically treated with mechanically aligned TKA with the use of conventional instruments. All patients underwent CT long leg scanograms after surgery, and outcomes data were collected at a minimum of 2 years. The patient, radiographic evaluator, and clinical evaluator were blinded as to the alignment method. Results. At a minimum of two years, all outcomes were better in the kinematically aligned group, as determined by the Oxford Knee Score of 41 which was 8 points better (p < 0.001), WOMAC score of 12 which was 13 points better (p = 0.002), Combined Knee Society Score of 164 which was 28 points better (p = 0.001) and flexion of 123 degrees which was 11 degrees better than the mechanically aligned group (p = 0.002). The odds ratio of having a pain free knee at 2 years with the kinematically aligned technique (Oxford and WOMAC pain scores) was 4.1 and 3.53 respectively, compared with the mechanically aligned technique. The hip-knee-ankle angle (0.3° difference; p = 0.693) and anatomicangle of the knee (0.8° difference; p = 0.131) were similar in the two groups. In the kinematically-aligned group, the angle of the femoral component was 2.4° more valgus (p < .001) and the angle of the tibial component was 2.3° more varus (p < .001) than the mechanically-aligned group (Figure 2). Discussion:. The Oxford Knee Score, WOMAC Score, Combined Knee Society Score and flexion were significantly better in the kinematic group at a minimum of two years. Oxford Knee and WOMAC pain scores were significantly better, and the number of pain free patients at 2 years was 3–4 times higher in the kinematically aligned group. The obliquity of the joint line was more anatomic in the kinematically aligned total knee replacement. This study showed that individualizing a total knee arthroplasty using 3-dimensional imaging, preoperative computer planning, and rapid prototyping technology in an attempt to replicate an individual patient's knee kinematics, provided better pain relief and restored better function and flexion compared to the mechanical alignment technique performed with conventional instruments

This study aimed to determine the prevalence of osteoporosis in patients awaiting hip and knee replacement for osteoarthritis and to review them two years later to determine the changes in bone density following joint replacement. Patients aged between 65 and 80 years awaiting total hip or knee replacement were invited to participate. Lumbar spine, bilateral femoral and forearm bone mineral density (BMD) measurements were obtained using dual energy x-ray absorptiometry. BMD values were standardised using previously published T-scores and Z-scores. To assess clinical status, patients completed a questionnaire including the Western Ontario and McMaster University OA Index (WOMAC). All measurements were repeated at two-years. Participants included 199 patients (84 hips and 115 knees) with a mean age of 72 years (SD 4.0) and were predominantly female (hips 67%, knees 50%). At baseline 46/199 (23%) patients (39 females) had evidence of osteoporosis (WHO definition) at one or more sites with the highest prevalence at the forearm (14%). At two-years 144 patients attended for review with 128 having undergone hip (56) or knee (72) replacement. At this review 39/144 (27%) patients (33 females) had evidence of osteoporosis at one or more sites with the highest prevalence at the forearm (22%). The greatest bone loss occurred at the forearm with median BMD change of minus 4% for females (25th percentile minus 7.3%, 75th percentile minus 1.9%) and minus 2.9% for males (25th percentile minus 4.6%, 75th percentile minus 1.1%). There was a significant difference in WOMAC Pain scores at follow-up between the osteo-porotic and non-osteoporotic knee patients (67 versus 81, p=0.002) indicating that osteoporotic patients had greater knee pain. We have identified the forearm as not only the site with the highest prevalence of osteoporosis but also the greatest bone loss at follow-up. Further evaluation of forearm bone density measurements in the preopera-tive assessment and follow-up of patients awaiting joint replacement for hip and knee OA is required. Larger studies are needed to confirm our finding that the presence of osteoporosis is predictive of worse patient-reported outcomes of knee replacement

Introduction:. Two fixed bearing options exist for tibial resurfacing when performing unicompartmental knee arthroplasty (UKA). Inlay components are polyethylene-only implants inserted into a carved pocket on the tibial surface, relying upon the subchondral bone to support the implant. Onlay components have a metal base plate and are placed on top of a flat tibial cut, supported by a rim of cortical bone. To our knowledge, there is no published report that compares the clinical outcomes of these two implants using a robotically controlled surgical technique. We performed a retrospective review of a single surgeon's experience with Inlay versus Onlay components, using a robotic-guided protocol. Methods:. All surgeries were performed using the same planning software and robotic guidance for execution of the surgical plan (Mako Surgical, Fort Lauderdale, FL). The senior surgeon's prospective database was reviewed to identify patients with 1) medial-sided UKA and 2) at least two years of clinical follow up. Eighty-six patients met these inclusion/exclusion criteria: 41 Inlays and 45 Onlays. Five patients underwent a secondary or revision procedure during the follow up period and were considered separately. Our primary outcome was the WOMAC score, subcategorized by the Pain, Stiffness, and Function sub-scores. The secondary outcome was need for secondary surgery. Continuous variables were analyzed using the two-tailed Student's t-test; categorical variables were analyzed using Fisher's exact test. Results:. Average follow up was 2.7 years and 2.3 years in the Inlay and Onlay groups, respectively. The post-op WOMAC Pain score was 3.1 for Inlays and 1.6 for Onlays (p = 0.03). The post-op Stiffness score was 1.8 for Inlays and 1.4 for Onlays (p = 0.19). The post-op Function score was 10.3 for Inlays and 6.7 for Onlays (p = 0.12). We identified a subgroup of 51 patients (23 Inlay, 28 Onlay) for whom there was both pre- and post-op WOMAC data available. There were no differences in the pre-op Pain, Stiffness, or Function scores between groups. In this subgroup, the Pain score improved from 8.3 to 4.0 for Inlays, versus an improvement from 9.2 to 1.7 for Onlays (p = 0.01). The Stiffness score improved from 3.9 to 2.2 for Inlays, versus an improvement from 4.3 to 1.5 for Onlays (p = 0.08). The Function score improved from 27.5 to 12.5 for Inlays, versus an improvement from 32.1 to 7.3 for Onlays (p = 0.03). When all 86 patients in the study were considered, 4/41 Inlays (9.8%) underwent a secondary procedure during the two year follow up (two conversions to total knee replacement [TKR]; one conversion to an Onlay component; one internal fixation of a subchondral compression fracture). In the Onlay group, 1/45 patients (2.2%) underwent a secondary procedure, a conversion to TKR (p = 0.20). Discussion:. Onlay UKR demonstrated improved pain relief compared to inlay UKR at two years of follow up. There was a trend toward improved function and fewer secondary surgical procedures with the onlay device. We advise surgeons performing UKA to preferentially use Onlay implants in order to maximize clinical benefit

Hip resurfacing arthroplasty has become a popular treatment option for younger active patients. The early published results from designing surgeons/centers have been favourable. We undertook a prospective multi-center trial to determine the outcome of hip resurfacing arthroplasty at independent centers. The clinical, radiographic and functional results were assessed. A prospective IRB approved study was initiated in July 2003 to assess the outcome of hip resurfacing arthroplasty using a contemporary design implant. (Conserve Plus - Wright Medical Technology) Disease specific (Harris Hip Score/WOMAC) and global (Rand self assessment index) outcome measures were used. Radiographs were reviewed for component position and migration as well as any signs of lysis or loosening. Complications and re-operations were recorded. A total of one hundred and eighty-eight patients have been enrolled in the study to date. One hundred and four patients have a minimum one year follow-up and forty-six patients have a minimum two year follow-up. Mean Harris Hip Scores (pre-op, one year, two years) were fifty-five, eighty-nine and ninety-one. Mean WOMAC pain scores were forty-seven, ninety and ninety. Mean WOMAC stiffness scores were forty, seventy-eight and eighty-two. Mean WOMAC function scores were forty-six, eighty-seven and eighty. RAND physical function mean scores were thirty-three, seventy-six and seventy-six and the RAND physical limitations mean scores were nineteen, sixty-seven and seventy-five. Radiographic analysis showed average cup abduction to be forty-six degrees (range twenty-six to sixty-three). Average femoral stem position was one hundred and thiry-eight degrees (range one hundred and eighteen to one hundred and fifty-seven). Nine patients have been revised to date (4.8%). Four for acetabular loosening, two for neck fracture, one for femoral loosening, one for impingement and one for persistent pain. There have been eight other patients requiring re-operation without revision. Medical complications occurred in fifteen patients. Early results have demonstrated a good return of function in patients with hip resurfacing arthroplasty. A high early revision rate (4.8%) was seen in our study. Technical factors appear to be the main contributor to the high early complication rate. Hip resurfacing is associated with a steep learning curve. We continue to utilise hip resurfacing in select patients but recommend caution for those who are new to the technique

Background: There are many clinical and radiographic long term results of Total Hip Arthroplasties reported in literature but very few attend to the subjective quality of life of patients living with an implant. In the last few years different quality of life assessment scores were developed. In this study the subjective SF-36 and the WOMAC score were evaluated and the results were compared to the commonly used clinical Harris Hip Score. Patients and methods: From a total number of 152 cement-less Total Hip Arthroplasties (Alloclassic®) performed between October 1987 and December 1988 at our clinic, 103 hips in 99 patients were available for a clinical and radiographic evaluation with an average follow-up of 14.3 years. For clinical evaluation the Harris Hip Score was used. Additionally all patients got SF-36 and WOMAC questionnaires. 78 questionnaires were returned fully completed and could be evaluated. The overall results and the results in the domain “pain” and “function” which occur in all three scores were compared statistically. Results: The mean Harris Hip Score was 88.2 (range 24 – 100), pain score 41.9 and function score 48.4. The mean WOMAC Score was 10.6 in total, pain 2.8 and function 3.9. The SF-36 domain “Bodily Pain” was 56.6 and “physical function” 48.2. Concerning the domain “function” a significant correlation was found in all of the three scores (p < 0.01). A significant “pain” correlation was seen comparing the SF-36 to the WOMAC score (p < 0.01). No significant correlation was found comparing the clinical Harris Pain Score to the SF-36 domain “Bodily Pain” and to the WOMAC pain score. Conclusion: In this study the subjective assessment questionnaires SF-36 and WOMAC show significant similar results to the clinical Harris Hip Score concerning the domain “function”. Concerning “Pain” comparable results were found between the SF-36 and the WOMAC with no significant correlation to the HHS. These data suggest that the quality of life assessment questionnaires can not replace the clinical evaluation using a clinical score

Background: Previous studies reported that several kinematic parameters such as tibial posterior slope, joint line, and femoral posterior condylar offset influence clinical outcomes including maximum flexion after total knee arthroplasty (TKA). However, the effects of the kinematic factors may vary with the implant type. We aimed to determine whether implant type influence the associations between the three kinematic factors (posterior slope, joint line, posterior condylar offset) and clinical outcomes. We hypothesized that the associations between the kinematic factors and clinical outcomes would differ among four implant types [fixed bearing cruciate retaining (FB-CR), fixed bearing posterior stabilized (FB-PS), mobile bearing cruciate retaining (MB-CR), and mobile bearing posterior stabilized (MB-PS)]. Methods: A retrospective review of 1300 TKAs performed with one of the four implant types (FB-CR, FB-PS, MB-CR, MB-PS) was performed to select 50 TKAs for each implant type of which 1 year clinical outcomes (maximum flexion, AKS scores, patellofemoral scores, WOMAC, and SF-36) were available. Three radiographic parameters (posterior slope, joint line, and posterior condylar offset) were measured using pre- and post-operative lateral radiographs and postoperative alterations were calculated from the measurements. The correlations between the alterations in the radiographic parameters and the clinical outcomes were compared among the four groups by the implant type. Results: In 4 designs of implant (FB-CR, FB-PS, MB-CR and MB-PS), the mean increase in posterior condylar offset was +0.22, +0.67, +0.33 and +1.26, respectively. The mean joint elevation was −0.31, +1.34, −0.12 and +1.96, respectively. The mean posterior slope was 6.10, 5.64, 5.01 and 4.59, respectively. The mean maximum flexion was greater in the PS designs than in the CR designs (137.0° in FB-PS and 136.4° in MB-PS vs. 132.2° in MB-CR and 130.1° in FB-CR, p < 0.05). No significant correlations between the alterations in the radiographic parameters and maximum flexion. No significant correlations were found between the alterations in the radiographic parameters and the clinical outcomes in all implant types but the MB-CR type. In MB-CR type, the elevation of joint line was significantly associated with worse WOMAC stiffness and function scores (correlation Coefficient = 0.36 and 0.30, respectively) and the increase of posterior condylar offset was associated with a worse WOMAC pain score (correlation coefficient = 0.39). Conclusion: Our findings indicate that the effects of the alterations in the kinematic parameters on the clinical outcomes vary with the implant type. This study also indicates that implant type is more important in determining postoperative maximum flexion than the alterations in the kinematic parameters

Aims

The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach.

Introduction: Unicondylar knee arthroplasty (UKA) has seen a resurgence in the past decade. Perpetuation of this trend can only be supported through prospective demonstration of efficacy with validated outcomes measures. Materials & Methods: Thirty-three consecutive cemented medial Miller-Galante UKA’s (Zimmer, Warsaw, IN) were performed in 32 patients (7 males/25 females; mean age of 67 ± 9 years). Average weight, height, and body mass index (BMI) of the patient population was 189 ± 31 lbs (Range, 145–293), 65 ± 4 in (range, 60–75), and 33 ± 5 BMI (range, 25–43), respectively. Average polyethylene thickness (as labelled) for this cohort was 8.3mm (range, 8–12mm). Outcomes were prospectively assessed via the SF-12, WOMAC, and Knee Society Score (KSS). No patients were lost to follow-up. Kaplan-Meier survivorship and Student’s t-test were performed using GraphPad Prism 4 software (GraphPad Software Inc., San Diego, CA). Results: Minimum follow-up was 39 months with a mean follow up period of 49 (range, 39–59) months. One knee was converted at 6 months at another institution to a TKA. Kaplan-Meier survivorship analysis reported 97% survivorship at 59 months (95% CI). Of the 32 knees remaining, mean preoperative KSS and WOMAC pain scores improved significantly from 52 ± 7 (range, 37–67) to 89 ± 9 (range, 67–100) (p< 0.0001) and from 40 ± 22 (range, 0–80) to 93 ± 14 (range, 35–100) (p< 0.0001), respectively. Additionally, average SF-12 Physical Component scores significantly increased from 30 ± 7 (range, 18–51) at baseline to 49 ± 10 (range, 28–59) at time of follow-up (p< 0.0001). Overall stiffness and physical function assessed via the WOMAC index also exhibited statistically significant improvement, bettering from mean baseline scores of 54 ± 24 (range, 0–100) and 52 ± 19 (range, 25–87) to 84 ± 19 (range, 50–100, p< 0.0001) and 88 ± 15 (range, 44–100, p< 0.0001), respectively. No significant cement/bone interface radiolucencies were found upon thorough radiographic review at 3 years post UKA. Discussion & Conclusion: The significant improvements observed in knee function & stiffness, and decreases in pain at a mean of 4 years after medial UKA are encouraging. Coinciding results from the physical component of the SF-12 assessment indicate reassurance of physical improvements regarding patient lifestyle. 97% survivorship in the short term would be discouraging if not for the specific circumstances of the sole conversion to TKA. This specific patient went against the advice of the operative surgeon and solicited services at an outside institution in conversion to a TKA despite markedly improved function (Pre-op/3 month post-op WOMAC and KSS of 30/75 and 60/91). Clinical and radiographic follow-up will continue in order to assess the long-term efficacy of medial UKA with the Miller-Galante prosthesis using strict patient selection criteria

Aims

To compare the in vivo long-term fixation achieved by two acetabular components with different porous ingrowth surfaces using radiostereometric analysis (RSA).

Aims

It is not known whether change in patient-reported outcome measures (PROMs) over time can be predicted by factors present at surgery, or early follow-up. The aim of this study was to identify factors associated with changes in PROM status between two-year evaluation and medium-term follow-up.

Objectives

It has been hypothesized that patellofemoral pain, a common knee condition in adolescents and young adults, may be a precursor of degenerative joint changes and may ultimately lead to patellofemoral osteoarthritis. Since both conditions share several mechanical disease characteristics, such as altered contact area between the femur and patella and increased joint stress, we investigated whether these conditions share similar and different shape characteristics of the patella compared with normal controls.

We investigated whether an asymmetric extension gap seen on routine post-operative radiographs after primary total knee replacement (TKR) is associated with pain at three, six, 12 and 24 months’ follow-up. On radiographs of 277 patients after primary TKR we measured the distance between the tibial tray and the femoral condyle on both the medial and lateral sides. A difference was defined as an asymmetric extension gap. We considered three groups (no asymmetric gap, medial-opening and lateral-opening gap) and calculated the associations with the Western Ontario and McMaster Universities osteoarthritis index pain scores over time.

Those with an asymmetric extension gap of ≥ 1.5 mm had a significant association with pain scores at three months’ follow-up; patients with a medial-opening extension gap reported more pain and patients with a lateral-opening extension gap reported less pain (p = 0.036). This effect was still significant at six months (p = 0.044), but had lost significance by 12 months (p = 0.924). When adjusting for multiple cofounders the improvement in pain was more pronounced in patients with a lateral-opening extension gap than in those with a medial-opening extension gap at three (p = 0.037) and six months’ (p = 0.027) follow-up.

Cite this article: Bone Joint J 2013;95-B:472–7.

Several factors have been implicated in unsatisfactory results after total hip replacement (THR). We examined whether femoral offset, as measured on digitised post-operative radiographs, was associated with pain after THR. The routine post-operative radiographs of 362 patients (230 women and 132 men, mean age 70.0 years (35.2 to 90.5)) who received primary unilateral THRs of varying designs were measured after calibration. The femoral offset was calculated using the known dimensions of the implants to control for femoral rotation. Femoral offset was categorised into three groups: normal offset (within 5 mm of the height-adjusted femoral offset), low offset and high offset. We determined the associations to the absolute final score and the improvement in the mean Western Ontario and McMaster Universities osteoarthritis index (WOMAC) pain subscale scores at three, six, 12 and 24 months, adjusting for confounding variables.

The amount of femoral offset was associated with the mean WOMAC pain subscale score at all points of follow-up, with the low-offset group reporting less WOMAC pain than the normal or high-offset groups (six months: 7.01 (sd 11.69) vs 12.26 (sd 15.10) vs 13.10 (sd 16.20), p = 0.006; 12 months: 6.55 (sd 11.09) vs 9.73 (sd 13.76) vs 13.46 (sd 18.39), p = 0.010; 24 months: 5.84 (sd 10.23) vs 9.60 (sd 14.43) vs 13.12 (sd 17.43), p = 0.004). When adjusting for confounding variables, including age and gender, the greatest improvement was seen in the low-offset group, with the normal-offset group demonstrating more improvement than the high-offset group.

Cite this article: Bone Joint J 2014;96-B:36–42.