Proximal ulna non-union: treatment concept and postoperative outcome.

Purpose: Non-union of the proximal ulna is a serious complication after surgical treatment of olecranon and complex elbow fractures, frequently leading to poor functional outcome. To date, there is a lack of data regarding optimal treatment strategies and functional outcome parameters after surgical revision.

Methods: From 02/2010 to 12/2018, 31 patients undergoing surgical treatment of proximal ulna non-union could be included. Follow-up period was seven years (SD 2.5 years). All patients were clinically assessed using a clinical assessment tool set and standard elbow scores (MEPS, OES, DASH score). All complications and unplanned revision surgeries were recorded and all radiographic material was analyzed.

Results: Initial non-union procedures were performed at an average of 6.6 months (SD 3 months) after the index procedures. Those included the use of autologous spongiosa graft in all patients and concomitant compression re-osteosynthesis in 28 patients. Radiological consolidation was achieved in all patients. Overall, patients achieved a good to fair functional outcome with Mayo elbow performance score measuring 78.5 (SD 9.1), DASH score 34.7 (SD 14.4), and Oxford elbow score 31.2 (SD 6.6) points. Initial malreduction/implant-malposition could be identified as a main reason for the occurrence of the non-union. Furthermore, inferior postoperative outcome was detected in patients > 60 years and BMI > 30 kg/m.

Conclusion: Using a standardized protocol, bony union and acceptable functional outcomes can be achieved in proximal ulna non-unions. However, surgeons should be aware of potential risk factors and proper initial fracture reduction as key to achieve sufficient bone healing.