Comparison of total knee replacement outcomes using patient-specific templating between severe intra- and extra-articular deformities

Background: Managing total knee arthroplasty (TKA) for patients with severe intra- and extra-articular deformities poses a challenge for many surgeons. Therefore, this study aimed to assess the outcome of the patient-specific templating (PST) technique in TKA for osteoarthritis with severe intra- and extra-articular deformities. Methods: Data from the Egyptian Community Arthroplasty Registry were prospectively collected for matched cases of knee osteoarthritis with severe intra- and extra-articular deformities who had TKA using the PST technique. A total of 77 knees in 45 patients (32 bilateral): 13 men and 32 women were identified. Extra-articular deformities were found in 27 knees (15 patients), and a matched group of 50 knees with intra-articular deformities of 20 degrees or more (30 patients) were included. The knee society score (KSS) was assessed preoperatively and at six months postoperatively. Results: The mean age at surgery was 62.1 (range 35–95) years. In the intra-articular group, the mean pre-operative KSS was 25.1, while it was 97.0 postoperatively. In the extra-articular group, the mean KSS was 21.5 preoperatively, while it was 97.1 postoperatively. No differences in mortality or severity of complications were detected. However, the intra-articular group had a higher rate of overall complications. Conclusion: Both intra- and extra-articular deformities had significant and nearly equal functional improvement after TKA using the PST technique. All procedures were performed using PST without conversion to the conventional technique. This provides hope for utilizing the hospital-based PST technique in low-and-middle-income countries to operate on such complex cases.