Delayed-onset ulnar neuritis after release of elbow contracture: preventive strategies derived from a study of 563 cases.

PURPOSE

The purposes of this study were to determine whether delayed-onset ulnar neuritis (DOUN) after elbow contracture release can be prevented and to compare the efficacy of ulnar nerve decompression versus subcutaneous transposition.

METHODS

A retrospective study of 563 consecutive arthroscopic elbow contracture releases was conducted. The prophylactic efficacy of (1) subcutaneous transposition, (2) ulnar nerve decompression, (3) limited ulnar nerve decompression (7 to 8 cm), and (4) mini-decompression (4 to 6 cm) was assessed prospectively. The efficacy of prophylactic strategies (transposition, decompression, limited decompression, or mini-decompression) in preventing DOUN was compared by univariate survival analysis. Patients who underwent a subcutaneous transposition were matched with patients who underwent a standard open decompression or a limited decompression, according to gender, age (±10 years), diagnosis, and preoperative motion. This analysis was repeated after we excluded the patients who underwent associated open procedures (e.g., hardware removal).

RESULTS

DOUN occurred in 26 of 235 patients (11%) who did not undergo any prophylactic procedure versus 8 of 295 patients (3%) who underwent a prophylactic ulnar nerve decompression or transposition at the time of contracture release (P < .001). The neurologic impairment was significantly less severe after prophylactic decompression compared with patients without any prophylactic intervention (grade on Neuropathy Grading Scale, 2 vs. 4; P = .03). Ulnar nerve transposition and decompression were equally protective. The decompression length was the only factor significantly related to the failure of the prophylactic intervention (odds ratio, 0.19; P = .02). A mini-decompression was not as effective as a prophylactic procedure, whereas a limited decompression was equal to a standard decompression. The case-control analysis showed that the decompression and transposition had equal preventive effects but the transposition was associated with a higher rate of wound complications (19% vs. 4%, P = .03).

CONCLUSIONS

DOUN is a complication of arthroscopic elbow contracture release. Its incidence and severity can be reduced by limited open ulnar nerve decompression or transposition.

LEVEL OF EVIDENCE

Level II, prospective comparative study with retrospective analysis.