Improvement in functional outcome 1 year after nonsurgical multidisciplinary treatment for chronic pain after total knee arthroplasty: A prospective cohort study.

PURPOSE: The purpose of this study was to evaluate a multidisciplinary intervention developed for patients with debilitating chronic pain after total knee arthroplasty (TKA) unresponsive to existing treatment options. METHODS: A treatment-based prospective cohort study was caried out in 30 TKA patients with debilitating chronic pain at least 1 year after TKA. The treatment was a multidisciplinary intervention. Main inclusion criteria: no indication for surgery. Primary outcome was function measured by KOOS-PS, OKS, OKS-APQ and WORQ. Secondary outcome measures were pain, fear of movement, self-efficacy, quality of life (QoL), health care and pain medication use, work rehabilitation and patient satisfaction. The assessments took place pre- and directly posttreatment, at 1, 3 and 12 months follow-up. The clinical relevance was assessed by predefined minimal important clinical change (MCIC). RESULTS: At baseline patients were on average 64.7 (±7.9) years old, 67% were female, and they had knee pain for 42 (10-360) months. The results at 12-month follow-up: first, a significant improvement was shown in function, pain, fear of movement, self-efficacy and QoL. Second, in 38.5%-69.2% of patients clinical relevant improvement was shown for functional outcome, 31% for pain, and 50% for self-efficacy. Third, 42% of patients reported 'no healthcare use in the past three months'. CONCLUSION: One year after a multidisciplinary treatment a clinically relevant improvement was shown in terms of function, pain, self-efficacy and QoL. It seems to be a promising treatment option in this difficult-to-treat patient group with debilitating chronic pain after TKA. Future research should examine the effect of the treatment in a larger study population, considering a control group, and focusing on the working population and evaluating cost-efficacy. LEVEL OF EVIDENCE: Level II.

Late Onset Metallosis after Revision Total Knee Arthroplasty with Metal-Backed Patellar Component In Situ.

We describe a small case series with severe metallosis after revision total knee arthroplasty (TKA) due to metal-backed patellar component failure. Metallosis is a rare complication after TKA, which may cause systemic and local symptoms. In our cases, diagnosis of metallosis was supported by radiographic imaging and aseptic aspiration. Two of our 3 cases were successfully revised; in the remaining case surgery was not desired because of her poor general condition. Based on these cases, we recommend performing regular checkups in case of a metal-backed patellar component to detect metallosis in an early stage, to prevent extensive revision surgery. Moreover, we recommend applying a low threshold to revise a metal-backed patellar component because of the severe consequences of metallosis that might occur.