Decompression of the posterior interosseous nerve for tennis elbow.

Decompression of the posterior interosseous nerve (PIN) was performed in 111 cases of tennis elbow. After a median follow-up time of 5 years, 85% showed improvement and 30% were almost completely relieved of their symptoms, the latter figure being considered to represent the real frequency of PIN entrapment. It thus seems that the PIN is one etiological factor in tennis elbow, but it cannot be distinguished from other causative factors by currently available methods. The confounding factor of PIN decompression being effective in cases of tennis elbow of other origins is discussed.