Suprascapular nerve injuries with isolated paralysis of the infraspinatus.

Nerve lesions are frequently overlooked in the differential diagnosis of shoulder pain, and there have been few reports in the literature of injuries of the supracapsular nerve that involve only the infraspinatus. We report four cases of suprascapular nerve injuries which involve solely the infraspinatus in which each patient presented with shoulder pain and weakness. The diagnosis can be suspected by careful history and physical examination, but must be confirmed by the appropriate electrical studies. Our patients required 6 months to 1 year to regain full function, and isokinetic testing revealed near normal return of strength. Further diagnostic work-up and surgery may be necessary for those cases which fail to demonstrate satisfactory improvement in the expected time period.