The lateral para-olecranon approach for unlinked total elbow arthroplasty with the Kudo prosthesis in patients with rheumatoid arthritis: midterm outcomes

The lateral para-olecranon approach preserves triceps integrity while providing adequate exposure for unlinked total elbow arthroplasty (TEA). However, its effectiveness in patients with rheumatoid arthritis (RA) remains unclear. This study aimed to evaluate midterm clinical and radiographic outcomes of unlinked TEA performed via the lateral para-olecranon approach in patients with RA, focusing on triceps function, range of motion (ROM), strength, and complications. Among 43 elbows (39 patients) undergoing unlinked TEA with the Kudo type 6 prosthesis via the lateral para-olecranon approach, 2 were excluded because of death and 1 underwent implant removal for deep infection. The final clinical cohort comprised 40 elbows in 36 patients (27 women, 9 men; mean age, 64 &#xb1; 13 years; mean follow-up, 73 &#xb1; 33 months). Preoperative radiographs showed Larsen grade III in 12 elbows (30%) and grade IV in 28 elbows (70%). Outcomes included active ROM; flexion and extension strength measured by handheld dynamometry; manual muscle testing; Mayo Elbow Performance Score; and radiographic assessment. All ROM parameters improved significantly: flexion, 121&#xb0; &#xb1; 17&#xb0; to 137&#xb0; &#xb1; 6&#xb0;; extension, -34&#xb0; &#xb1; 17&#xb0; to -26&#xb0; &#xb1; 10&#xb0;; pronation, 64&#xb0; &#xb1; 16&#xb0; to 76&#xb0; &#xb1; 15&#xb0;; and supination, 59&#xb0; &#xb1; 28&#xb0; to 73&#xb0; &#xb1; 24&#xb0; (P < .001 for flexion and pronation; P = .0022 for extension; P = .0010 for supination). Flexion and extension strength increased from 16 &#xb1; 14 to 26 &#xb1; 20 N (P = .0016) and from 13 &#xb1; 12 to 23 &#xb1; 16 N (P < .001). All elbows maintained manual muscle testing grade 5 triceps strength. Mean Mayo Elbow Performance Score increased from 55 &#xb1; 9 to 92 &#xb1; 8 (P < .001). Among 40 elbows with implants in situ, radiographic evaluation revealed no type III or IV lucency. Kaplan-Meier analysis of 41 elbows demonstrated 97.1% implant survival (95% confidence interval, 81.4%-99.6%). Complications included 2 intraoperative medial epicondyle fractures (5%) and 1 deep infection requiring implant removal (2%). No triceps insufficiency, subluxation, or nerve palsy occurred. Unlinked TEA performed via the lateral para-olecranon approach provides favorable midterm outcomes in patients with RA and Larsen grade III-IV disease, preserving triceps function while achieving significant improvements in pain, ROM, strength, and overall elbow function. Complete absence of triceps insufficiency and the favorable outcomes support the present approach as a viable treatment option for appropriately selected patients with RA.