Total Knee Arthroplasty with Plate Osteosynthesis Provides a Reliable Solution for Concurrent Acute Metaphyseal Stress Fractures and Osteoarthritis: A Case Series.

Acute metaphyseal tibial stress fractures (AMTSF) in the setting of severe osteoarthritis (OA) were relatively rare. Total knee arthroplasty (TKA) with a long stem was considered the preferred treatment. However, achieving rotational stability solely with a long stem at the metaphyseal level remained questionable. We report four female patients (mean age 65.3 ± 11.8) with AMTSF and severe OA between 2021 and 2022. All presented with sudden pain, weight-bearing inability, swelling, and proximal leg tenderness. Radiographs confirmed complete metaphyseal stress fractures. Each had vitamin D deficiency, and two had secondary hypoparathyroidism. Fractures were stabilized with medial plating to ensure rotational stability and provide a secure foundation for TKA. Knee Society Score and Functional Score improved from 14.8 ± 6.8 and 23 ± 16.2 to 86 ± 8.7 and 85 ± 10.3 (p < 0.05). No complications occurred during follow-up. In AMTSF with severe OA, TKA combined with plate osteosynthesis reliably achieves fracture union and excellent functional outcome. Level of evidence: IV. Level of clinical care: Level I Tertiary trauma center.