Diabetic amyotrophy masquerading as quadriceps tendon rupture: a word of caution

Diabetic amyotrophy is predominantly a motor condition that involves various elements of the lumbosacral plexus but particularly that related to the femoral nerve. (1,3) It can present acutely as unilateral thigh pain followed by the development of weakness and later wasting in the femoral muscles, usually first seen in the quadriceps. We report on two cases of diabetic amyotrophy from different hospitals that presented with clinical signs and symptoms of quadriceps rupture. These patients underwent surgical exploration but in both the quadriceps tendons were found to be intact. Post-operative neurological consultations established the diagnosis as diabetic amyotrophy, which was confirmed with electrodiagnostic studies. We conclude that any quadriceps rupture in diabetics should be viewed with caution. Electrodiagnostic studies and imaging with ultrasound and magnetic resonance imaging should be carried out before exploratory surgery.