Muscle strength measurements and functional outcome of an untreated complete distal rectus femoris muscle tear.

A 46-year-old man sustained an injury to his right thigh while skiing. He sought medical advice after 6 weeks, presenting a palpable painful mass of his anterior proximal thigh but no functional deficit. An isolated complete distal intrasubstance tear of the rectus femoris muscle was diagnosed on ultrasound and MRI scans, and the patient received no medical treatment. Functional and dynamometer tests after 1 year showed high limb symmetry indexes and only slightly reduced values for peak torque and total work on the injured side. The patient had resumed skiing activities and reported slight pain after intense downhill skiing runs, but no functional limitations. MRI scans after 19 months showed increased retraction of the rectus femoris muscle. The natural history of an untreated complete distal rectus femoris muscle tear with no functional deficit may result in minimal disability.