The prevalence of gluteal tendinopathy (GT) associated with osteoarthritis of the hip is difficult to determine as it is frequently undiagnosed or misdiagnosed as trochanteric bursitis. Its relationship to total hip arthroplasty (THA) outcomes is currently unknown. The aim of this study was to determine the incidence of GT at the time of hip arthroplasty and examine the relationship between GT and patient reported outcomes (PROMS) before and after THA. Patients undergoing THA for primary osteoarthritis between August 2017 and August 2020 were recruited. Tendinopathy was assessed and graded at time of surgery. PROMS included the Oxford Hip Score (OHS), HOOS JR, EQ-5D, and were collected preoperatively and at one year after THA. Satisfaction with surgery was also assessed at 1 year. 797 patients met eligibility criteria and were graded as Grade 1: normal tendons (n =496, 62%), Grade 2: gluteal tendinopathy but no tear (n=222, 28%), Grade 3: partial/full thickness tears or bare trochanter (n=79, 10%). Patients with abnormal gluteal tendons were older (p=0.001), had a higher mean BMI (p=0.01), and were predominately female (p=0.001). Patients with higher grade tendinopathy had statistically significant inferior PROMS at one year, OHS score (44.1 v 42.9 v 41.3, p 0.001) HOOS JR (89.3 V 86.3 V 85.6 p 0.005). Increasing gluteal tendon grade was associated with a greater incidence of problems with mobility (p=0.001), usual activities (p=0.001) and pain (p=0.021) on EQ5D. There was a 3 times relative risk of overall dissatisfaction with THA in the presence of gluteal tears. This study demonstrated that gluteal tendinopathy was commonly observed and associated with inferior 1-year PROMS in patients undergoing THA for OA. Increasing degree of tendinopathy was a negative prognostic factor for worse functional outcomes and patient satisfaction.
Obesity is a common in individuals undergoing arthroplasty, and the potential for weight loss with improved mobility may be expected by some. The aim of this study was 1. determine the proportion that achieved weight loss after hip or knee arthroplasty, and 2. examine the effect of obesity on patient reported outcomes (PROMS) and satisfaction with surgery. Participants underwent primary TKA or THA between July 2015 and December 2020 and consented to participation in a research database with baseline PROMS, including weight, BMI, Oxford Knee, or Hip Score, and EQ5D. Participants repeated PROMS at 12 months after surgery with additional questions regarding satisfaction with surgery. 3449 patients completed PROMS 1 year after arthroplasty with weight and BMI. There were 1810 THA and 1639 TKA procedures. The mean baseline BMI was higher in TKA (29.8, SD 5.2) compared to THA (27.7, SD 5.0), p=0.001. A higher proportion of TKA were classified as obese class 1 (29% TKA, 19% THA), obese class 2 (11% TKA and 6% THA), and obese class 3 (5% TKA and 2% THA), p=0.001. The mean weight loss after 1 year was 0.4kg and 0.9kg in obese THA subjects and TKA subjects respectively. In the obese >5kg weight loss was achieved in 13% of TKA and 7% of THA (p=0.001). Obese experienced equivalent improvement in Oxford scores, compared to non-obese subjects. Satisfaction with surgery was reported by 95% of THA and 91% of TKA subjects with no significant differences between BMI group grades (p=0.491 THA and p=0.473 TKA). Preoperative obesity was observed in 44% of TKA and 27% of THA subjects. In the obese only 1 in 10 subjects lost 5kg or more over 12 months. Obese patients experienced equivalent improvements in outcome after arthroplasty and rates of satisfaction with surgery to the non-obese.
Total hip arthroplasty (THA) has high rates of patient satisfaction; however patient expectations for recreational and sporting activities are not always met. Our study aimed to identify preoperative factors that predict whether patient expectations for sporting or recreational activity are met 12 months following THA. Patient reported outcome measures (PROMs) were collected prospectively from 2015-2018 at one private hospital in Sydney. Age, gender, postcode, weight, and height were recorded preoperatively. Included participants underwent primary THA by one of the investigating surgeons. Univariable and multivariable analyses were performed with an expectation fulfilment score used as the primary outcome variable. Preoperative predictor variables included: age, gender, BMI, Socio-economic Indexes for Areas (SEIFA), Oxford Hip Score, Hip Osteoarthritis Outcome Score, EQ-5D-5L and EQ Visual Analogue Scale (EQ VAS). 1019 participants were eligible and included. 13% reported that preoperative expectations of sport or recreation were not met at 12 months. Younger age, lower preoperative EQ VAS, and higher BMI were associated with failed expectations on multivariable analysis. Odds of failed expectations increased by 2% for every one year younger in age (OR= 0.98, 95% CI = 0.96 to 1.00, p=.048), by 2% for every one point lower on EQ VAS (OR=0.98, 95% CI = 0.98 to 0.99, p=.002), and by 4% for every one-point increase in BMI (OR = 1.04, 95% CI = 1.00 to 1.09, p=.042). Failure to have expectations met for sporting or recreational activity was associated with younger age, poorer general health, and high BMI. With a rise in younger patients who likely have higher physical demands, a tailored preoperative education is preferable to generic models to better manage patient expectations. Younger age, higher BMI, and poorer health may predict unmet expectations for sport and recreation after THA. Tailored education in these groups should be considered.
The morbidity associated with tendinopathy is a costly burden on our health system. Recent investigations in our laboratory have shown that alterations in mechanical stress cause significant changes in tendon expression of key matrix molecules and proteolytic enzymes including the aggrecanase molecules, (e.g. ADAMTS-5). Here, we investigate the biomechanical consequences of such altered tensile stress in tail tendons from mice with and without deletion of the ADAMTS-5 gene. Tail tendons from 12 week old C57BL6 wild type and ADAMTS-5 knock-out mice were immediately snap frozen (ex vivo), or cultured stress deprived for 120 hours in DMEM/10% FCS (eight tendons per group). Material properties including maximum stress, strain and elastic modulus were determined for each tendon in uniaxial tension to failure at a constant strain rate of 1.0 mm/second (10% strain/second) on an Instron 8874 servo-hydraulic testing apparatus. Significant differences between groups were determined with Kruskal-Wallis one-way analysis of variance, followed by Mann-Whitney U test with Benjamini-Hochberg post-hoc corrections for multiple comparisons. Stress deprivation for 120 hours led to a significant increase in maximum stress for both the wild type (~150% increase, p = 0.0008) and ADAMTS-5 deficient (~100%, p = 0.0033) mice when compared to ex vivo tendon. Stress deprivation led to a 100% increase in elastic modulus compared to ex vivo for the wild type tendons (p = 0.0033) but failed to increase this parameter in the ADAMTS-5 deficient mice. When the effect of stress deprivation of the ADAMTS-5 deficient mice was directly compared to the wild type stress deprived tendons, a 35% decrease in elastic modulus was found (p = 0.021). We have shown for the first time that deletion of an aggrecanase molecule significantly decreases the material properties of tendon. Alterations in the expression of the aggrecanase molecules may play a role in the development and progression of tendinopathy through their ability to modulate the metabolism of aggrecan [
