Joint awareness after fixed and mobile-bearing total knee arthroplasty with minimum 12 years of follow-up: A propensity matched-pair analysis.

BACKGROUND: Many comparative articles studied mobile-bearing (MB) and fixed-bearing (FB) total knee arthroplasties (TKAs). Meta-analyses found no difference in survival or biomechanical outcome. This study aimed to compare long-term clinical results between fixed-bearing (FB) and mobile-bearing (MB) total knee arthroplasty (TKA) as well as patients' adaptation to their artificial joints. METHOD: TKAs performed with the same surgical protocol divided into categories according to the insert design preferred. 70 MB design TKAs were compared with 70 FB design TKAs utilizing propensity matching for parameters; gender, age, body mass index, coronal plane deformity, range of motion (ROM) and appropriateness criteria. Forgotten Joint Score-12 (FJS-12) was used to assess patients' ability to forget their artificial joints in daily life. RESULTS: Patients had a mean follow-up of 15.6 (±2.2) years. No difference was observed between groups for post-operative ROM, WOMAC, Knee Society Knee and Function Scores. The FJS-12 in the MB and FB groups were 66.1 and 72.8, respectively (P = 0.026). There was no significant difference in survival between both designs. CONCLUSION: This study suggests that in TKA, joint awareness is higher in MB compared to FB design. FJS-12 appears to be a sensitive measuring tool when comparing two designs and should be implemented in long-term follow-up.

Scintigraphic evaluation of impaction grafting for total hip arthroplasty revision.

To determine the fate of an impacted allograft after a minimum follow-up of 1 year, we examined 9 of 40 patients who underwent revision arthroplasty with the impaction grafting technique. The allograft used in this study was morselized cancellous freeze-dried allograft. We examined these 9 patients with technetium-99 m methylene diphosphonate bone scintigraphy at an average of 14 (range 12-20) months after surgery. All of them had a good clinical outcome, with an average postoperative Hip Society Score of 89 (range 65-98) and no evidence of radiolucency or subsidence on direct radiography. Scintigraphic examination demonstrated that the area corresponding to the allograft had a remarkable radioactivity accumulation suggesting new bone formation. The allograft in total hip revision using the impaction grafting technique undergoes a significant neovascularization and new bone formation. This study suggests than when vigorous impaction is used, freeze-dried cancellous allograft can be used for impaction grafting.