A biochemical perspective on bone-implant interface healing after cemented knee arthroplasty: role of serum calcium and ALP

Abstract Objectives Osteointegration at the bone-cement interface is essential for the long-term success of implants following cemented total knee arthroplasty (TKA). This study aims to assess the time-dependent changes in serum calcium (Ca) and alkaline phosphatase (ALP) levels after TKA and to explore their relationship with functional recovery and osteointegration potential. Methods This prospective study involved 100 patients who underwent primary cemented TKA. Serum Ca and ALP levels were measured before surgery and at postoperative days 1, 3 weeks, 6 weeks, 6 months, and 1 year. Functional outcomes were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), while pain levels were recorded with a 10-point Visual Analog Scale (VAS). Knee range of motion (ROM) was measured with a goniometer. Correlation and multivariate regression analyses were conducted to assess links between biochemical markers and clinical outcomes. Radiographic osteolysis was evaluated through standard X-rays. Results Serum Ca levels significantly declined over time (p<0.001), while ALP showed a biphasic pattern. Clinical outcomes, including WOMAC, VAS, and ROM, improved markedly (all p<0.001). However, no significant correlations were observed between Ca or ALP levels and these outcomes (all p>0.05). Conclusions Although measurable changes in serum calcium and ALP levels are observed following cemented TKA, these parameters demonstrate limited clinical utility as systemic markers of osteointegration or predictors of functional recovery. is warranted to assess implant integration and postoperative bone healing better.