Arthroscopy for Bennett fractures: A prospective series of 8 cases

Abstract

The Bennett fracture is a trauma associating an intra-articular fracture of the first metacarpal and a trapezio-metacarpal joint subluxation; the prognosis of this trauma depends on quality of reduction and preservation of ligamentous anatomy. This prospective case series aims at demonstrating that arthroscopic procedure for Bennett fractures can improve both the quality of reduction and the preservation of ligamentous anatomy. Over a period of 18 months, 8 intra-articular fractures of the first metacarpal were operated on with arthroscopy. We only retained recent (< 21 days) trauma without extra-articular fracture. We used 2 portals, a 1.9 mm arthroscope, percutaneous cannulated screws and an adhesive strip for closure, a gauntlet splint for 3 weeks followed by an active/passive physiotherapy. Physical examination and X-ray were performed after 3, 6 and 12 weeks. Analysis criteria were: – peroperative: ligament impairment, duration of surgery; – postoperative: pain, trapezio-metacarpal motion (Ant-Retropulsion, Abd-Adduction, Kapandji score), key pinch strength, time off work and sports, X-ray analysis (reduction, consolidation, secondary displacement). All patients were reviewed 3 times. The duration of surgery went down from 60 to 20 minutes; a partial fracture of the trapezium was found in 2 cases; the collateral volar-ulnar ligament was impaired in 2 cases. Active range of motion was: – 3 weeks: Ant 30° – Retro 0°, Abd 20° – Add 5°, Kapandji 4; – 6 weeks: Ant 50° – Retro 10°, Abd 40° – Add 15°, Kapandji 8, key pinch strength 70%; – 12 weeks: Ant 50° – Retro 10°, Abd 40° – Add 15°, Kapandji 10, strength 90%. One patient was still experiencing pain under strain after 12 weeks despite good joint stability. We noticed 7 anatomic reductions and no secondary displacement. Time off work was 4 weeks (1–6); time off upper limb sports was 8 weeks (6–12). Functional mobility was regained after 6 weeks, accompanied by good strength. Arthroscopy seems to be a reliable and efficient procedure for Bennett fractures. Recovery and functional outcomes are at least the same as with an open procedure, whereas arthroscopy reduces morbidity and duration of surgery.