Objective To discuss the surgical procedures and curative effect of stiff 2-5 metacarpophalangeal (MP) joints after crash injury in hand. Methods Between January 2006 and June 2009, 7 cases of stiff 2-5 MP joints were treated by releasing the stiff MP joints and reconstructing the function of lumbrical muscle in one stage. There were 6 males and 1 female with an average age of 32 years (range, 18-56 years). All injuries were caused by crash. Six cases suffered from multiple metacarpal fracture or complex dislocation of MP joint and 1 case suffered from complete amputation at level of middle palm of hand. The interval from initial wound heal ing to hospital ization was 3 to 15 months. Before operation, the X-ray films showed fracture healed and the results of nipping paper test were positive. All hands were treated with physical therapy for 1 month. After the plaster external fixation for 6 weeks, the physical therapy and function training were given. Results All wounds healed by first intention. The patients had no joint instabil ity and extensor tendon side-sl ipping with normal finger function. Six patients were followed up from 6 months to 3 years. The extension and flexion of MP joint were 0° and 67-90°, respectively. The average grip strength of injured dominant hand reached 86.70% of normal side and non-dominant hand reached 66.70% of normal side. The average injured dominant tip pinch strength reached 83.52% of normal side and non-dominant tip pinch strength reached 61.30% of normal side. Based on total active motion (TAM) system of Chinese Medical Association for Hand Surgery, the results were excellent in 4 cases, good in 1 case, and fair in 1 case; the excellent and good rate was 83.33%. Conclusion In patients with stiff MP joint and lumbrical muscle defect, releasing stiff MP joint and reconstructing lumbrical function in one stage can recover the function of MP joint and achieve good outcome. Physical therapy plays an important role before operation.