Stability of the metatarsophalangeal joint of the lesser toes: A cadaveric study

Abstract

Dorsal instability of the metatarsophalangeal joint (MTPJ) of the lesser toes is an important cause of forefoot pain. Both conservative and surgical treatment options have been proposed. However, the role of each static stabilizing structure has not been elucidated. We hypothesized that isolated sectioning of the plantar plate (PP) would result in greater dorsal translation compared to isolated sectioning of the medial collateral ligaments (MCL) or lateral (LCL) collateral ligaments, or the extensor hood (EH), and that combined injury to two or more structures would result in greater dorsal translation compared to isolated PP injury. Fifty‐four cadaveric lesser toe specimens were randomized into groups for individual and combined sectioning of the PP, EH, and LCL and MCL. A 30 N axial load was applied to each specimen in the plantar–dorsal direction and dorsal translation of the phalanx was measured for each condition. ANOVA was used to compare groups. A 19% change in MTP translation was found from intact after sectioning the PP. No significant difference in translation was seen after individual sectioning of the EH, MCL, or LCL. A significant increase in translation occurred from intact with the following sectioning combinations: MCL + LCL, 37%; EH + MCL + LCL, 45%; and PP + MCL + LCL, 63%. Thus, the PP is the main restraint for dorsal MTPJ translation. MCL and LCL have important partial contribution to MTPJ stability. Injury to the PP, individually, or combined injuries to the PP, EH, MCL, or LCL, appear to cause significant instability that may warrant more aggressive treatment. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1995–1998, 2012

Metatarsophalangeal joint stability: a systematic review on the plantar plate of the lesser toes

“…Bhatia et al [16] and Suero et al [5] used vertical forces measuring vertical translation. Cooper et al [6] used horizontal measurement of total distraction of the metatarsal head and proximal phalanx base.…”

“…Metatarsalgia symptoms such as gradual onset of forefoot pain, edema and a positive drawer sign can be explained by instability of the metatarsophalangeal (MTP) joint [4, 5], MTP joint instability is described as a dorsal subluxation or dislocation of the base of the proximal phalanx over the metatarsal head. The traditional etiology of instability of the lesser MTP joints in the sagittal and/or transverse plane is described in the literature by plantar plate degeneration and rupture [6, 7].…”

Plantar plate radiofrequency and Weil osteotomy for subtle metatarsophalangeal joint instablity

“…Currently, it is known that the plantar plate plays an important role in the stabilization of the lesser metatarsophalangeal joints. Recent biomechanical studies have shown that PP was the main isolated stabilizer of the MTP joints in the dorsal–plantar direction [ 4 ]. Deland and Sung [ 20 ] showed how an isolated repair of the collateral ligaments was insufficient to resolve instability resulting from PP deformity, which may indicate that the PP itself has a crucial role in stabilizing the joint.…”

Lesser Metatarsophalangeal Instability: Diagnosis and Conservative Management of a Common Cause of Metatarsalgia

“…The MTP joint is primarily stabilized by the plantar plate, 12,21,40 and damage through repetitive stress ultimately leads to an unstable joint. 6,21,34 The plantar plate is a critical anatomic structure composed of fibrocartilage that lies on the inferior aspect of the MTP joint (Figure 1). 12,14 Without its support, the proximal phalanx will deviate dorsally.…”