The efficacy of trabecular metal Cones in reconstructing metaphyseal bone defects during revision total knee arthroplasty / 中华骨科杂志

ABSTRACT

Objective:To investigate the clinical outcomes and efficacy of trabecular metal (TM) cones for the reconstruction of metaphyseal bone defects in revision total knee arthroplasty.Methods:A retrospective analysis was conducted on 46 patients (47 knees), who underwent revision total knee arthroplasty with TM cones for metaphyseal defect reconstruction from July 2015 to August 2023. The cohort comprised 12 males and 34 females, ranging from 41 to 83 years of age, with a mean of 68.65 ± 9.09 years. Body mass index (BMI) ranged from 19.5 to 36.0 kg/m 2, averaging 27.20±4.50 kg/m 2. Bone defects were stratified according to the Anderson Orthopedic Research Institute (AORI) classification, including 64 sides (AORI T2B type 20 sides, T3 type 16 sides, F2B type 11 sides, F3 type 17 sides) which were addressed with 67 cones. Evaluations during follow-up included range of motion (ROM), visual analogue scale (VAS) for pain, and the American Knee Society Score (KSS). Long leg radiographs and knee X-rays were reassessed for femorotibial angle (FTA) and joint alignment, osseointegration of the TM cones, and any complications were documented. Results:The average follow-up duration was 46.22±26.55 months (range 16-103 months). The KSS knee score significantly improved from 29.22±19.79 preoperatively to 88.22±6.01 at the final follow-up ( F=258.118, P<0.001). Similarly, the KSS function score saw a marked increase from a preoperative average of 7.65±8.21 to 56.30±6.10 at the final follow-up ( F=354.711, P<0.001). VAS scores significantly decreased from 5.35±1.50 preoperatively to 0.28±0.50 at the final follow-up ( F=300.934, P<0.001). ROM improved from 67.72°±34.62° preoperatively to 85.33°±9.15° at the final follow-up ( F=7.798, P<0.001), and the FTA improved from 179.24°±10.30° preoperatively to 174.39°±1.69° at the final follow-up, a statistically significant enhancement ( F=9.123, P<0.001). Osseointegration was observed in 95.5% of the cases (64/67 cones). There were no instances of osteolysis or aseptic loosening observed, indicating stable prosthetic fixation. Complications were minimal, with one reported case of a femoral shaft fracture, which was successfully treated with internal fixation, resulting in satisfactory healing at 6 months. At the last follow-up (3 years after operation), the patient could walk at home with a walker and the other patients had no complications such as periprosthetic joint infection, dislocation and periprosthetic fracture. Conclusion:The application of trabecular metal cones in revision total knee arthroplasty provides an effective solution for the reconstruction of severe metaphyseal bone defects, enhancing prosthetic stability and restoring the knee joint's mechanical alignment. The trend towards successful osseointegration in the TM cones is promising, and a significant improvement in knee joint function has been observed.