顺行髓内针内固定术治疗第五掌骨颈和头下骨折

Antegrade intramedullary fixation of the neck and subcapital fractures of the fifth metacarpal

目的探讨有明显移位的第五掌骨颈和头下骨折的治疗方法。方法2005年1月至8月，采用顺行髓内针内固定术治疗第五掌骨颈及头下型骨折共31例。其中11例为头下型骨折（A组），20例为掌骨颈骨折（B组）。A组术前第五掌骨头干角为63．4°±14．5°，B组术前第五掌骨头干角为59．1°±10．0°。将骨折闭合复位后，用1枚末端预弯成20°角直径2．0mm的钝头克氏针作为髓内针固定骨折。术后A组加用石膏外固定4周，而B组未用外固定，允许早期主动活动。结果手术时间平均18min（5～30min），31例中，29例获得解剖复位，2例骨皮质对位2／3，对线良好。所有患者均获得随访，随访时间3～6个月，平均4个月。A组术后第五掌骨头干角为15．0°±2．5°，骨折愈合后为15．4°±2．6°，与术前比较，差异均有统计学意义，而与健侧第五掌骨头干角14．2°±2．3°比较，差异无统计学意义，术后掌指关节主动活动范围89．5°±4．3°，与健侧差异无统计学意义；B组术后第五掌骨头干角为15．9°±2．5°，骨折愈合后为15．5°±2．8°，与术前比较，差异均有统计学意义，而与健侧第五掌骨头干角差异无统计学意义，术后掌指关节主动活动范围88．6°±3．6°，与健侧差异无统计学意义。结论顺行髓内针内固定术治疗第五掌骨颈及头下骨折，手术操作简单、创伤小、外固定时间短、费用低廉、治疗效果好、并发症少，是一种理想的治疗方法。

Objective To investigate the treatment of the displaced neck and subcapital fractures of the fifth metacarpal. Methods Thirty-one patients with the neck and subcapital fractures of the fifth metacarpal had been operated on with antegrade intramedullary fixation between January and August 2005. There was 11 subcapital fractures （group A）, and 20 neck fractures （group B）. Following closed reduction of the fracture, a blunt 2. 0 mm diameter K-wire, which was pre-bent into 20°at the distal end, was inserted into the medullary canal of the fifth metacarpal and fixed the fractures. Postoperatively, patients in group A were immobilized in a short arm plaster splint for 4 weeks, and the ones in group B were treated with unrestricted mobilization. Results Operative time was 18 min averagely （range 5 to 30 min）. Twenty-nine of 31 patients obtained anatomic reduction, and 2 patients had 2/3 apposition of bone end and no rotational deformity. Follow-up was available for all patients. The average follow-up interval was 4 months, with a range of 3-6 months. The head/shaft angle of the fifth metacarpal in group A was 63.4° ± 14. 5° preoperatively, and 15.0° ± 2.5° postoperatively, and 15.4° ± 2.6° in 3 months postoperatively. The difference between preoperative and postoperative angles was highly significant. The range of motion of the metacarpal joint was 89. 5° ±4. 3° postoperatively,which was not significantly different compared with that of uninjured side. The head/shaft angle in group B was 59. 1° ± 10. 0° preoperatively, and 15.9° ± 2. 5° postoperatively, and 15.5° ±2. 8° in 3 months postoperatively. The difference between preoperative and postoperative angles was highly significant. The range of motion of the metacarpal joint was 88.6° ± 3.6° postoperatively ,which was not significantly different compared with that of uninjured side. Conclusions The technique is technically easy to perform, minimally invasive, low-cost, allowing early hand mobilization, with good functional results and low morbidity, and it has been proved to be an ideal method.