We dissected 21 cadaver elbows to determine the relationship of the posterior interosseous nerve to the posterolateral approach to the elbow and head of the radius. At the distal end of the exposure the first branches at risk, those to extensor carpi ulnaris, were on average 6.0 ± 1.0 cm (4.0 to 8.4) from the articular surface of the radial head. When using the posterolateral approach it is important that the interval between extensor carpi ulnaris and anconeus is clearly identified with the forearm fully pronated. The supinator should be released close to its ulnar border. It is safe to expose the proximal radius as far as the distal aspect of the bicipital tuberosity

We operated on 16 patients for ulnar neuropathy associated with osteoarthritis of the elbow. They were all male manual workers, with an average age of 51 years at the time of surgery. The severity of the symptoms was McGowan grade 1 in five patients, grade 2 in nine and grade 3 in two. The mean follow-up was 36 months. The operation consists of resecting the osteophytes around the postcondylar groove. The shallow and narrow cubital tunnel is made deep and wide and the ulnar nerve is replaced with its surrounding soft tissues in the enlarged groove. All patients were relieved of discomfort and all showed some improvement or full recovery of motor and sensory function. The ulnar nerve showed no evidence of irritation or adhesion. This procedure also allows early movement of the elbow after operation, because the subcutaneous tissues and muscles have not been detached