Abstract
BACKGROUND: Massive bone defects present significant challenges in complex primary total knee arthroplasty (TKA). Previous studies with limited sample sizes have demonstrated the potential of metaphyseal sleeves (MS) in addressing such defects. This study mainly aimed to assess the clinical outcomes and survivorship of MS utilized for reconstructing bone defects in complex primary TKA among East Asian patients, with a secondary focus on the use of scews for tibial residual bone defect. METHODS: A total of 3,672 primary TKAs were performed between January 2016 and December 2020, of which 106 procedures (87 patients) utilized MS in conjunction with straight stems to address bone defects. Among these, 55 (46 patients) incorporated screws for tibial residual bone defect, while 51 (41 patients) were performed without screws. The mean follow-up period was 57.86 months, during which demographic data, operative details, clinical and radiographic outcomes, complications, and implant survivorship were recorded and analyzed. RESULTS: All cases demonstrated successful osteointegration, with both the endpoint reoperation and revision implant survival rates reaching 100%. The mean Hospital for Special Surgery (HSS) score significantly improved from 56.98 to 82.36 at the final follow-up, resulting in an overall excellent and good outcome rate of 95.40%. Knee conditions were notably worse in the screw group compared to the non-screw group; however, the clinical and radiographic outcomes between the two groups were comparable. Postoperative tibial end-of-stem pain was reported in 9.8% of the non-screw group, while none (0%) in the screw group, reflecting marginal significance (P = 0.0548). CONCLUSION: The application of metaphyseal sleeves with straight stems represents a promising strategy for addressing massive bone defects in complex primary TKA among East Asian patients. The cement-screw technique, providing potential biomechanical advantages, emerges as a safe and effective solution for managing residual defects surrounding MS placement in tibial site.