Deep Transverse Metatarsal Ligament and Static Stability of Lesser Metatarsophalangeal Joints: A Cadaveric Study

作者：Wang, Bibo; Guss, Andrew; Chalayon, Ornusa; Bachus, Kent N.; Barg, Alexej; Saltzman, Charles L.^*

来源：Foot & Ankle International, 2015, 36(5): 573-578.

DOI：10.1177/1071100714563310

• lesser metatarsophalangeal joint
• deep transverse metatarsal ligament
• plantar plate
• lesser metatarsophalangeal joint instability

Background: The static support that guides motion around the lesser metatarsophalangeal joints (MTPJs) is complex. Biomechanical studies revealed important roles of both the plantar plane and collateral ligaments. Since part of the plantar plate is attached to the deep transverse metatarsal ligament (DTML), we hypothesized that the transection of the DTML in the intermetatarsal space may substantially reduce the MTPJ stability.
Methods: The second, third, and fourth MTPJ stabilities of 6 fresh-frozen human cadaveric foot specimens were measured under load control. Both dorsiflexion and dorsal subluxation conditions were tested. After the intact condition was assessed, the DTML was sequentially transected such that each MTPJ had a unilateral and then a bilateral DTML transection. Stiffness data were calculated using the loading range in each test condition. Paired Student t tests were performed to test for statistical significance (P value less than .05).
Results: In intact specimens, the mean stiffness with dorsiflexion of the second, third, and fourth toes was 0.52 0.15 N/deg. When the DTML was operatively transected on one side, the dorsiflexion stiffness significantly decreased 17.3% to an average of 0.43 1.00 N/deg (P < .001). Subsequent transection of the DTML on the other side of each joint resulted in a further significant decrease of 5.8% to an average of 0.40 +/- 0.08 N/deg (P < .001). The mean stiffness with dorsal subluxation of the intact second, third, and fourth toes was 3.55 +/- 0.66 N/mm. When the DTML was operatively transected on one side, the dorsal subluxation stiffness significantly decreased 16.1% to an average of 2.98 +/- 0.64 N/mm (P < .001). Subsequent transection of the DTML on the other side of each joint resulted in a further significance decrease of 7.6% to an average of 2.71 +/- 0.48 N/mm (P = .016).
Conclusion: The DTML has a significant role in maintaining lesser MTPJ ligament stability. Both unilateral and bilateral DTML transections caused substantial instability of the lesser MTPJ.

• 出版日期2015-5
• 单位上海交通大学; 上海市闵行区中心医院