gms | German Medical Science

Objectives: Injuries of the lumbrical muscles have rarely been described in the past but are currently rapidly increasing due to changing sporty preferences (e.g. climbing). We now aimed to retrospectively study imaging findings, clinical presentations and outcomes of patients with lumbrical muscle injuries treated according a standardized diagnostic and therapeutic algorithm.

Method: Clinical data and imaging findings of 60 patients suffering from an acute lumbrical muscle strain trauma in the middle hand were retrospectively reviewed. Clinical examination, magnetic resonance imaging (MRI) and ultrasound (US) were performed before and after treatment. Lumbrical muscle injuries were graded according to the severity of clinical and imaging findings as grade I-III injuries. The therapy consisted of immobilization, functional therapy and adapted sport activities according to injury grade.

Results: Clinical testing with shear stress examination of the flexor tendons was positive in all patients. Grade II injuries with partial tears of the lumbrical muscles were detected in 32/60 patients (Grade II). Positive imaging correlation with complete detachment of the lumbrical muscle from the flexor tendons was present in 10/60 patients (Grade III). Follow up US and MRI showed injury healing in all patients. All patients had an uncomplicated outcome and regained full sporty activieites.

Conclusion: Lumbrical muscle tears are frequently encountered injuries in climbing sport but also appear in non-climbers. Overall outcome among our study collective was positive und uncomplicated, but symptoms may recur or become chronic if not treated sufficiently. Evaluation of specific clinical and imaging findings is necessary for grading the injuries and determination of therapy.