Objectively measured 24-hour activity profiles before and after total hip arthroplasty

Aims The purpose of this exploratory study was to investigate if the 24-hour activity profile (i.e. waking activities and sleep) objectively measured using wrist-worn accelerometry of patients scheduled for total hip arthroplasty (THA) improves postoperatively. Patients and Methods A total of 51 THA patients with a mean age of 64 years (24 to 87) were recruited from a single public hospital. All patients underwent THA using the same surgical approach with the same prosthesis type. The 24-hour activity profiles were captured using wrist-worn accelerometers preoperatively and at 2, 6, 12, and 26 weeks postoperatively. Patient-reported outcomes (Hip Disability and Osteoarthritis Outcome Score (HOOS)) were collected at all timepoints except two weeks postoperatively. Accelerometry data were used to quantify the intensity (sedentary, light, moderate, and vigorous activities) and frequency (bouts) of activity during the day and sleep efficiency. The analysis investigated changes with time and differences between Charnley class. Results Patients slept or were sedentary for a mean of 19.5 hours/day preoperatively and the 24-hour activity pattern did not improve significantly postoperatively. Outside of sleep, the patients spent their time in sedentary activities for a mean of 620 minutes/day (sd 143) preoperatively and 641 minutes/day (sd 133) six months postoperatively. No significant improvements were observed for light, moderate, and vigorous intensity activities (p = 0.140, p = 0.531, and p = 0.407, respectively). Sleep efficiency was poor (< 85%) at all timepoints. There was no postoperative improvement in sleep efficiency when adjusted for medications (p > 0.05). Patient-reported outcome measures showed a significant improvement with time in all domains when compared with preoperative levels. There were no differences with Charnley class at six months postoperatively. However, Charnley class C patients were more sedentary at two weeks postoperatively when compared with Charnley class A patients (p < 0.05). There were no further differences between Charnley classifications. Conclusion This study describes the 24-hour activity profile of THA patients for the first time. Prior to THA, patients in this cohort were inactive and slept poorly. This cohort shows no improvement in 24-hour activity profiles at six months postoperative. Cite this article: Bone Joint J 2019;101-B:415–425.

Predictors of Early Stem Loosening after Total Hip Arthroplasty: A Case-Control Study

Purpose. To evaluate the influence of patient characteristics on stem loosening after cemented or uncemented total hip arthroplasty (THA) using a matched case-control study. Methods. Consecutive records of 4372 cemented (716 cases and 3656 controls) and 809 uncemented (115 cases and 694 controls) primary THAs between 1981 and 2003 in 30 hospitals in 8 European countries were reviewed. Cases and controls were defined as patients with and without stem loosening, respectively. In cases of bilateral THA, patients were their own controls. Cases and controls were matched for hospital, date of surgery, date of follow-up, stem type, and head size. Patient characteristics such as gender, age, weight, height, body mass index (BMI), diagnosis, presence of previous surgery on the affected hip, and walking restrictions according to the Charnley classification were recorded. Results. Male patients were at higher risk of cemented stem loosening (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.4–2.2). Older patients were at lower risk of cemented stem loosening; the odds decreased by 3% per year older (OR, 0.97; 95% CI, 0.96–0.98). Regarding BMI, the odds of cemented stem loosening increased by 3% for each additional unit of BMI over 25 kg/m2 (OR, 1.03; 95% CI, 1.004–1.05). Patients in Charnley class B had a lower risk of cemented stem loosening (OR, 0.75; 95% CI, 0.61–0.93). Conclusion. Advanced age, female gender, and Charnley class B (as a proxy measure of reduced walking activity) have a protective effect on survival of cemented stems, whereas a higher BMI was a risk factor.

Habitual Physical Activity Behavior of Patients After Primary Total Hip Arthroplasty

Background and Purpose Despite recognized health benefits of physical activity, little is known about the habitual physical activity behavior of patients after total hip arthroplasty (THA). The purpose of this study was to analyze this behavior and the fulfillment of guidelines for health-enhancing physical activity of these patients compared with a normative population. Subjects and Methods The participants were 273 patients who had undergone a primary THA (minimum of 1 year postoperatively). Comparisons were made between this group and 273 age- and sex-matched individuals from a normative population. Comparisons also were made between participants with THA under 65 years of age and those 65 years of age and older and among participants with THA in different Charnley classes. Level of physical activity was assessed with the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH). Results No significant differences in total amount of physical activity or time spent in different categories of physical activity were found between the THA group and the normative group. Participants with THA spent significantly more minutes in activities of moderate intensity compared with the normative group. Participants with THA who were under 65 years of age were significantly more active than older participants with THA. Charnley class had significant effects on time spent at work, time spent in moderate-intensity activities, and total amount of activity, with the least activity performed by participants in Charnley class C. The guidelines were met by 51.2% of the participants with THA and 48.8% of the normative population. Female participants met the guidelines less frequently than male participants in both the combined groups (odds ratio=0.50, 95% confidence interval=0.35–0.72, P&lt;.001) and the THA group (odds ratio=0.48, 95% confidence interval=0.28–0.80, P=.001). Discussion and Conclusion The results suggest that patients after THA are at least as physically active as a normative population. Nevertheless, a large percentage of these patients do not meet the guidelines; therefore, they need to be stimulated to become more physically active.

Bone mineral density 10 years after a Zweymüller uncemented stem prosthesis

The effect of a Zweymüller uncemented stem prosthesis on the long-term bone remodelling of femoral bone was examined using dual-energy X-ray absorptiometry (DEXA). Thirty-two patients (11 males, 21 females) with a unilateral prosthesis (18 Hochgezogen and 14 Stepless) were scanned at an average of 129.8 months after the initial operation. The average follow-up Harris Hip Score was 93.7: ten patients were classified as Charnley Class A, two patients as class B and 20 patients as class C. The group as a whole showed a moderate activity level and most patients were satisfied with the result of the operation. All stem prostheses were osseo-integrated. The non-operated contralateral femur was used as a control for the bone mineral density (BMD) changes in the femur around the prosthesis. A decrease of bone mineral density on the prosthesis side was found at the region of the calcar femoris, without any clinical decline or any radiographic anomalies.