Ulnar nerve decompression with osteocapsular arthroplasty for primary elbow osteoarthritis

Purpose The aim of this study was to suggest treatment guidline for primary elbow OA with ulnar nerve neuropathy or high-grade stiffness by evaluating the effect of ulnar nerve decompression on the outcome of osteocapsular arthroplasty. Methods A total of 30 patients who underwent primary osteocapsular arthroplasty for elbow OA were retrospectively reviewed. The surgical outcomes were evaluated for pain score (visual analog scale; VAS), range of motion (ROM), and Mayo Elbow Performance Score (MEPS). The ulnar nerve decompression was performed for (1) ulnar nerve neuropathy, and (2) high-grade stiffness of flexion, defined as the flexion angle, is <90 degrees. Patients were categorized into the two groups: ulnar nerve decompression group (UD group, n = 11) and the non-decompression group (Non-UD group, n = 19). The surgical outcome was compared between the groups. Results Primary elbow OA with cubital tunnel syndrome or high-grade stiffness showed comparable improvement in MEPS, VAS, and ROM arc at final follow-up in the UD group compared with the non-UD group (UD group vs. non-UD group: MEPS 85.91 vs 86.84, p-value = 0.824, VAS 1.46 vs 1.16, p-value = 0.588, ROM arc 108 vs 109, p-value = 0.949). Improvement in ROM arc at 2 years follow-up was significantly higher in UD group (UD group vs. non-UD group: ROM arc difference, 42 vs 14, p = 0.002). Conclusion Osteocapsular arthroplasty with ulnar nerve decompression for primary elbow OA with ulnar nerve neuropathy or high-grade stiffness provided improved motion arc and compatible clinical results.