Rationale, design and protocol of a longitudinal study assessing the effect of total knee arthroplasty on habitual physical activity and sedentary behavior in adults with osteoarthritis

Background: Physical activity levels are decreased and sedentary behaviour levels are increased in patients with knee osteoarthritis (OA). However, previous studies have shown that following total knee arthroplasty (TKA), objectively measured physical activity levels do not change compared to before the surgery. Very few studies have objectively assessed sedentary behaviour following TKA. This study aims to assess patterns of objective habitual physical activity and sedentary behaviour in patients with knee OA and to determine whether these change following TKA. Methods: Patients diagnosed with knee osteoarthritis and scheduled for unilateral primary total knee arthroplasty will be recruited from the Orthopaedic Division at the Charlotte Maxeke Johannesburg Academic Hospital. Eligible participants will have assessments completed one week before the scheduled arthroplasty, six weeks, and six months post-operatively. The primary outcomes are habitual physical activity and sedentary behaviour which will be measured using accelerometry (Actigraph GTX3+ and activPal monitors) at the specific time points. The secondary outcomes will be improvements in osteoarthritis-specific quality of life measures using the following questionnaires: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), Knee Society Clinical Rating System (KSS), UCLA activity index; subjective pain scores, and self reported sleep quality.Discussion: The present study will contribute to the field of musculoskeletal health by providing a rich detailed description of the patterns of accumulation of physical activity and sedentary behaviour in patients with knee OA. These data will contribute to existing knowledge using an objective measurement for the assessment of functional ability after total knee arthroplasty. Although studies have used accelerometry to measure physical activity in knee OA patients, the data provided thus far have not delved into the detailed patterns of how and when physical activity is accumulated before and after TKA. Accurate assessment of physical activity is important for physical activity interventions that target special populations

Piriformis muscle rupture during total hip arthroplasty using a muscle-preserving posterior approach

Total hip arthroplasty via muscle-sparing approaches is advocated and performed with increasing frequency. However, performing total hip arthroplasty through muscle-sparing approaches may require a more forceful retraction, which in turn may damage the muscles which the less invasive approach intended to preserve. We report on the rupture of the piriformis muscle during primary total hip replacement performed through a posterior approach intended to preserve this muscle. The prevalence and effects of such iatrogenic injuries are currently unknown, although unrecognised muscle damage may be a potential reason why early postoperative gait analyses could not demonstrate the expected benefits of less invasive surgery. Surgeons should be aware of this potential complication when performing total hip arthroplasty through a less invasive posterior approach.Lucian B. Solomon, Florian D. Naal, Donald W. Howi

Which Are the Most Frequently Used Outcome Instruments in Studies on Total Ankle Arthroplasty?

The number of studies reporting on outcomes after total ankle arthroplasty is continuously increasing. As the use of valid outcome measures represents the cornerstone for successful clinical research, we aimed to identify the most frequently used outcome instruments in ankle arthroplasty studies and to analyze the evidence to support their use in terms of different quality criteria. A systematic review of the literature identified 15 outcome instruments reported in 79 original studies. The most commonly used measures were the American Orthopaedic Foot and Ankle Society hindfoot score (n = 41), the Kofoed ankle score (n = 21), a visual analog scale assessing pain (n = 15), and the generic SF-36 (n = 6). Eight additional instruments were used only once or twice. The American Orthopaedic Foot and Ankle Society and Kofoed instruments include a clinical examination and score up to 100 points. Evidence to support their use in terms of validity, reliability, responsiveness, and interpretability is limited, raising the question whether their use is justified. Self-reported questionnaires related to ankle osteoarthritis or arthroplasty are rather disregarded in the current literature, and only the Foot Function Index is associated with evidence in terms of the above-mentioned quality criteria. Future research is warranted to improve the outcome assessment after total ankle arthroplasty