Wang Bibo, Guss Andrew, Chalayon Ornusa, Bachus Kent N, Barg Alexej, Saltzman Charles L
Shanghai Institute of Traumatology and Orthopaedics, Orthopaedic Department of Shanghai Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China University Orthopaedic Center, University of Utah, Salt Lake City, UT, USA.
Harold K. Dunn Orthopaedic Research Laboratory, University of Utah Orthopaedic Center, Salt Lake City, UT, USA.
Foot Ankle Int. 2015 May;36(5):573-8. doi: 10.1177/1071100714563310. Epub 2014 Dec 10.
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.
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).
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).
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.
The DTML is part of the natural static restraint to dorsiflexion or dorsal subluxation of the lesser MTPJ. Operative transection, injury, or degeneration of this ligament may predispose the adjacent MTPJ to instability.
引导小趾跖趾关节（MTPJ）周围运动的静态支撑结构较为复杂。生物力学研究揭示了跖平面和侧副韧带的重要作用。由于部分跖板附着于跖骨深横韧带（DTML），我们推测在跖骨间隙横断DTML可能会显著降低MTPJ的稳定性。
在负载控制下测量6个新鲜冷冻的人体尸体足标本的第二、第三和第四MTPJ的稳定性。测试了背屈和背侧半脱位两种情况。在评估完整状态后，依次横断DTML，使每个MTPJ先进行单侧DTML横断，然后进行双侧DTML横断。使用每个测试条件下的加载范围计算刚度数据。进行配对学生t检验以检验统计学显著性（P值小于0.05）。
在完整标本中，第二、第三和第四趾背屈时的平均刚度为0.52±0.15N/度。当在一侧手术横断DTML时，背屈刚度显著降低17.3%，平均降至0.43±1.00N/度（P<0.001）。随后在每个关节的另一侧横断DTML导致进一步显著降低5.8%，平均降至0.40±0.08N/度（P<0.001）。完整的第二、第三和第四趾背侧半脱位时的平均刚度为3.55±0.66N/mm。当在一侧手术横断DTML时，背侧半脱位刚度显著降低16.1%，平均降至2.98±0.64N/mm（P<0.001）。随后在每个关节的另一侧横断DTML导致进一步显著降低7.6%，平均降至2.71±0.48N/mm（P=0.016）。
DTML在维持小MTPJ韧带稳定性方面具有重要作用。单侧和双侧DTML横断均导致小MTPJ显著不稳定。
DTML是小MTPJ背屈或背侧半脱位的自然静态约束的一部分。该韧带的手术横断、损伤或退变可能使相邻的MTPJ易发生不稳定。
