We studied the integrity of the rotator cuff in both dominant and non-dominant shoulders of 90 asymptomatic adults between the ages of 30 and 99 years using ultrasound. The criteria for diagnosis had been validated on unembalmed cadaver specimens. We found no statistically significant difference in the incidence of impingement findings between dominant and non-dominant arms or between genders. The prevalence of partial-or full-thickness tears increased markedly after 50 years of age: these were present in over 50% of dominant shoulders in the seventh decade and in 80% of subjects over 80 years of age. Our results indicate that rotator-cuff lesions are a natural correlate of ageing, and are often present with no clinical symptoms. Treatment should be based on clinical findings and not on the results of imaging. J Bone Joint Surg [Br] l995:77-B:296-8.

An arthroscopic 2-row rotator cuff repair produces excellent functional outcome and repair integrity comparable with previously reported open repairs. Presence of a defect after repair did not appear to affect patient-reported function and return to preinjury activity but did affect measured strength.

US can depict most partial-thickness tears with use of the criteria described.

US can be used effectively to locate wooden foreign bodies as small as 2.5 mm in length. Given that many foreign bodies are radiographically undetectable, the accuracy and availability of US make it an excellent modality for evaluation of radiolucent foreign bodies.

Sonography can reveal a Morton's neuroma in 85% of cases. Identification of the presumed plantar digital nerve in continuity with the mass improves diagnostic confidence. The finding of an interdigital mass greater than 20 mm in length should raise suspicion of an abnormality other than a neuroma.