Abstract：
OBJECTIVE: The aim of this study was to determine whether the shape of the first metacarpal head influences metacarpophalangeal hyperextension, and to evaluate the influence of metacarpophalangeal hyperextension on hand pain and function in patients with trapeziometacarpal osteoarthritis.
METHODS: 362 patients with painful basal thumb osteoarthritis were evaluated over a 2-year period. Pain rating on a visual analog scale, trapeziometacarpal and metacarpophalangeal motion, and grip and pinch strength were evaluated. The shape of the metacarpal head was assessed on strict lateral radiographs using the \"A/r\" ratio.
RESULTS: Round metacarpal heads had significantly greater and more frequent metacarpophalangeal hyperextension than flat heads (28° vs. 8°, and 78% vs. 29%). Metacarpophalangeal hyperextension adversely impacted trapeziometacarpal motion in antepulsion (27° vs. 32°), abduction (25° vs. 30°) and pinch strength (3.6 vs. 4.6 KgF).
CONCLUSIONS: Our findings indicate that the shape of the metacarpal head influences metacarpophalangeal hyperextension in trapeziometacarpal osteoarthritis. Metacarpophalangeal hyperextension adversely impacted pinch strength and trapeziometacarpal motion.
METHODS: Level IV, Retrospective case series.
METHODS: 362 patients with painful basal thumb osteoarthritis were evaluated over a 2-year period. Pain rating on a visual analog scale, trapeziometacarpal and metacarpophalangeal motion, and grip and pinch strength were evaluated. The shape of the metacarpal head was assessed on strict lateral radiographs using the \"A/r\" ratio.
RESULTS: Round metacarpal heads had significantly greater and more frequent metacarpophalangeal hyperextension than flat heads (28° vs. 8°, and 78% vs. 29%). Metacarpophalangeal hyperextension adversely impacted trapeziometacarpal motion in antepulsion (27° vs. 32°), abduction (25° vs. 30°) and pinch strength (3.6 vs. 4.6 KgF).
CONCLUSIONS: Our findings indicate that the shape of the metacarpal head influences metacarpophalangeal hyperextension in trapeziometacarpal osteoarthritis. Metacarpophalangeal hyperextension adversely impacted pinch strength and trapeziometacarpal motion.
METHODS: Level IV, Retrospective case series.
摘要：
目的：本研究的目的是确定第一掌骨头的形状是否影响掌指骨过度伸展，评价掌指过伸对梯形掌骨关节炎患者手疼痛和功能的影响。
方法：对362例疼痛性基底拇指骨关节炎患者进行了为期2年的评估。视觉模拟量表上的疼痛评分，梯形掌骨和掌指骨运动，并对握力和捏合强度进行了评估。使用“A/r”比率在严格的横向X光片上评估掌骨头的形状。
结果：圆形掌骨头的掌指骨过度伸展明显大于平头（28°对8°，和78%对29%）。掌指骨过度伸展对前推时的梯形掌骨运动产生不利影响（与27°相比。32°),外展（25°与。30°)和夹紧强度(3.6与4.6KgF）。
结论：我们的研究结果表明，掌骨头的形状影响梯形掌骨骨关节炎的掌指过伸性。掌指骨过伸会对捏合强度和梯形掌骨运动产生不利影响。
方法：四级，回顾性病例系列。
方法：对362例疼痛性基底拇指骨关节炎患者进行了为期2年的评估。视觉模拟量表上的疼痛评分，梯形掌骨和掌指骨运动，并对握力和捏合强度进行了评估。使用“A/r”比率在严格的横向X光片上评估掌骨头的形状。
结果：圆形掌骨头的掌指骨过度伸展明显大于平头（28°对8°，和78%对29%）。掌指骨过度伸展对前推时的梯形掌骨运动产生不利影响（与27°相比。32°),外展（25°与。30°)和夹紧强度(3.6与4.6KgF）。
结论：我们的研究结果表明，掌骨头的形状影响梯形掌骨骨关节炎的掌指过伸性。掌指骨过伸会对捏合强度和梯形掌骨运动产生不利影响。
方法：四级，回顾性病例系列。
