Intraneural ulnar nerve pressure changes related to operative techniques for cubital tunnel decompression.

To evaluate the effect of critical anatomic structures on the ulnar nerve after cubital tunnel decompression, we determined the intraneural ulnar nerve pressure in 50 fresh cadavers after the following surgical procedures: simple decompression, medial epicondylectomy, subcutaneous transposition, and submuscular transposition by the Learmonth and by the musculofascial lengthening technique. Intraneural pressure was measured in 0 degrees, 30 degrees, 60 degrees, and 90 degrees elbow flexion at locations that were proximal, within, and distal to the cubital tunnel. Statistical analysis compared the mean change in intraneural pressure between the "postoperative" and the baseline "preoperative" pressure measurements for the different surgical strategies. While both the simple decompression and the medial epicondylectomy had significantly lower intraneural pressures than the Learmonth or the subcutaneous transposition, each of these four techniques resulted in elevated intraneural pressures. The musculofascial lengthening technique for submuscular transposition was the only surgical strategy that reduced intraneural ulnar pressure at each site of measurement and for all degrees of elbow flexion, this reduction of pressure being significant in comparison with the other surgical techniques.