The attachment of the plantar aponeurosis to the proximal phalanx of the toe, through the plantar plate (PP), forms the main flexor of the toe during gait by the reversed windlass mechanism. Disruption of the plantar plate is a common cause of pain, instability and toe deformity. Surgical techniques have recently been described to repair tears but long term results are awaited. This study aims to review the results of a technique designed to reconstruct and reinforce the failed plantar plate and restore the reversed windlass. Through a dorsal extra-articular approach the EDL tendon of the affected toe is used to restore the mechanical link between the proximal phalanx and the plantar aponeurosis on the plantar aspect of the joint. 42 PP reconstructions in 39 patients (36 female) aged 44–72 were undertaken, most frequently on the 2nd toe. 25 required correction of hallux valgus and four had undergone this previously. Follow up was 2–81 months.Introduction
Methods
Excision of prominent metatarsal heads for severe rheumatoid forefoot deformity is well established in clinical practice but results may deteriorate with time. The Stainsby forefoot arthroplasty however, recognises the pathological anatomy of the deformity and is designed to preserve the metatarsal heads by repositioning the plantar plates and forefoot fat pad underneath them. A prospective case series observing the clinical outcomes and changes in pedobarograph patterns in rheumatoid arthritis patients with severe deformity undergoing Stainsby forefoot arthroplasty.Introduction
Design
We present a retrospective comparative review of the radiological outcomes of Chevron and Scarf with Akin osteotomy in the treatment of hallux valgus.
The mean post-operative intermetatarsal angles (IMA) were: Chevron mean 8.050, standard deviation 2.560, standard error 0.57. Scarf with Akin mean 7.220, standard deviation 2.56, standard error 0.57. The difference in postoperative IMA between the two groups did not achieve statistical significance. The mean change in IMA for each was: Chevron mean increment 4.90 Standard deviation 2.290, standard error 0.51. Scarf with Akin mean increment 6.680, standard deviation 4.130, and standard error 0.88. The difference in alteration of IMA between the two groups did not achieve statistical significance.
Syndesmotic stability in ankle fractures is usually assessed by pulling on the fibula with a bone hook in the coronal plane (“hook test”). Our clinical observations have suggested that instability may be more marked in the sagittal plane. Our aim was to compare movement at the tibio-fibular syndesmosis in the sagittal and coronal planes after sequential ligament division in a cadaver model. Seven specimens were used. A blinded subject was asked to perform the hook test both in the sagittal and coronal planes. Movement was assessed by measuring the displacement of parallel k-wires three consecutive times. In all specimens, the anterior tibio-fibular, interosseous and posterior tibio-fibular ligaments were sequentially divided and movement tested. In three specimens the deltoid ligament was then divided and the interosseous membrane in another three. After division of all three syndesmosis ligaments the mean displacement was 8.8mm (±3.9) in the sagittal plane and 1.5mm (±0.4) in the coronal plane. When the deltoid ligament was then divided, the displacement increased to 11.7mm (±2.4) and 3.2mm (±0.5) respectively. When the interosseous membrane was divided the measurements were 12.7mm (±4) and 3.1mm (±1.5). We conclude that distal tibio-fibular instability should be assessed in the sagittal plane.
The purpose of this study was to investigate the influence of ligamentous restraints on first metatarsal (MT1) movements in the context of hallux valgus (HV), the surgical correction of which relies on a sound understanding of factors leading to MT1 deformity. Hypermobility or instability of the first metatarsal at its tarsometatarsal joint (TMJ1) is associated with greater degrees of deformity and also greater risk of recurrence after surgery. Recent anatomical work has shown the importance of the plantar aponeurosis (PA), and the transverse ‘tie-bar’ system (TTB) of the metatarsophalangeal (MPJ) plantar plates and intervening deep transverse inter-metatarsal ligaments in the structure and function of the foot. These ligamentous systems are important in MPJ stability, but may also be important at TMJ1. Ten normal cadaveric feet were dissected to expose the capsules and ligaments of the MPJs and TMTJs and the PA. They were then mounted in plaster of Paris leaving the MT1, MT2, and their articulations free. A loading fixture was constructed so that loads could be applied to MT1 in the transverse plane to produce moments in flexion, abduction or extension. The movements resulting from a load of 40N were measured relative to MT2 using an Isotrak II (Polhemus, US) magnetic measurement system. The tests were performed with the hallux mobile, fixed neutral and fixed dorsiflexed at the MPJ. After an initial test with all structures intact, the PA and the TTB were severed in random order and the test repeated. “Movement maps” were produced showing the range of motion available in different directions and with different ligamentous restraints. Movement maps suggest that the TMJ1 behaves as a ball and socket joint with no preferred axis of motion. The contributions of the PA and TTB to stiffness in the sagittal plane are small (about 1° movement). However, the TTB provides significant control of the abduction of MT1. The control afforded by the TTB is particularly important since it can ensure that the PA acts to provide an adduction moment about the TMJ1. The integrity of these ligamentous structures is likely to be important in the success of corrective surgical procedures for HV, where disruption can allow up to 10° increase in MT1-2 angles.
