外翻合并第二跖骨头下疼痛的生物力学定量研究

目的探讨跖骨头下压力变化与(足,母)外翻合并跖骨头下疼痛的关系,并对引起第二跖骨头下疼痛的跖骨头下压力进行定量分析.方法采用由中国中医研究院骨伤科研究所生物力学实验室研制的足底压力测试系统,对58名正常人(116足),32例(45足)(足,母)外翻单纯合并第二跖骨头下疼痛患者,56例(102足)(足,母)外翻无足底疼痛患者进行足底压力测试,将三组跖骨头下压力进行比较.采用病例-对照设计,研究压力与疼痛的关系,并对引起第二跖骨头下疼痛的压力进行定量分析.结果(1)(足,母)外翻单纯合并第二跖骨头下疼痛组分别与(足,母)外翻无足底疼痛组及正常组比较,第二跖骨头下压力均明显增高(均P＜0.05);(2)第二跖骨头下压力高于正常组与第二跖骨头下压力不高于正常组比较,疼痛的发生率明显增加(P＜0.05,OR＞3,OR95%CI＞1);(3)(足,母)外翻合并第二跖骨头下疼痛组第二跖骨头下压力占体重的5.20%～7.29%.结论跖骨头下压力异常增高是跖骨头下疼痛的危险因素,第二跖骨头下压力超过体重的5.20%,极易出现跖骨头下疼痛.

Biomechanical quantitativestudy in hallux valgus deformity associated with the second metatarsalgia

Objective To study the relation between the pressure in forefoot and the second metatarsalgia in hallux valgus deformity, finally to quantitatively analyze the pressure under the second metatarsal head which is a dangerous factor leading to second metatarsalgia. Methods Three groups volunteered for this study by a self-devised foot pressure measurement system: fifty-eight normal subjects (116 feet) without pain and deformity in foot, thirty-two patients (45 feet) with hallux valgus and pain only under the second metatarsal head, fifty-six patients (102 feet) with hallux valgus without symptoms of metatarsalgia. The percentage of pressure to weight was the criteria for data analysis. First the pressures under second metatarsal head among three groups were compared with each other. Secondly we used case-control study to identify whether it was high pressure that was likely to result in metatarsalgia. Finally we compared the pressure interval under second metatarsal head among three groups to define the pressure interval which might be a dangerous factor to second metatarsalgia. Results 1)The pressure beneath the second meatatarsal head in patients with metatarsalgia was the highest in the three groups (P< 0.05). 2) In case-control study, we calculated the odds ratio of the high pressure between the group with metatarsalgia and that without symptom. The odds ratio was larger than three. The low limit of 95% confident interval of the odds was larger than one. 3) The pressure under second metatarsal in the group with second metatarsalgia existed in the interval between 5.20% to 7.29% of body weight. Conclusion The increased pressure under metatarsal head is the dangerous factor leading to metatarsalgia. If the pressure under the second metatarsal head increases beyond 5.20% of weight, metatarsalgia will be happened at the region.