The first metatarsophalangeal (MTP) joint is the key joint of the foot in terms of function during gait. Various replacement toe joint prostheses are commercially available but unlike other replacement joints such as the hip or knee, few simulator based studies have been conducted to evaluate the performance and reliability of these prostheses. Presented are results obtained using a newly developed and validated multi-station MTP joint test-rig that is able to simulate the natural biomechanics of the toe joint. The developed simulator is a multi-station computer controlled electro-pneumatic metataso-phalangeal joint simulator that applies dynamic loading and motions commensurate with the walking gait cycle. This involves the combination of plantar-dorsi flexion range of 32 degrees, 5 degrees of inversion/eversion and toe-off dynamic loading peaking at up to 820 N. Presented are the validation and in vitro test results of MTP joint simulations carried out on silastic and articulating metal and polymer designs of MTP prostheses. Despite being subjected to a reduced loading regime of 300 N peak force, the silastic prostheses were found to perform poorly in the simulator, ultimately failing due to a combination of fatigue crack growth and joint collapse. This behaviour and failure mode was consistent with that of ex vivo origin silastic MTP prostheses examined and provides confidence in the validity of the simulator

One of the complications of hallux valgus surgery is shortening of the first metatarsal and this becomes particularly symptomatic in patients with a pre existing short metatarsal (Morton's foot or Greek foot). Initial treatment consists of appropriate insoles which incorporate not only relief of pain due to pressure metatarsalgia under the lesser metatarsal heads but also a Morton type extension under the big toe. Insoles with metatarsal relief are, however, not always well tolerated and surgery becomes necessary. The options are to shorten the lesser metatarsal heads or lengthen the previously shortened first metatarsal. Arthrodesis of the great toe metatarso-phalangeal joint can provide functional length to the first metatarsal. We have achieved good results in lengthening of the first metatarsal and believe that it is a safe option which avoids trauma to the lesser metatarso-phalangeal joints. The technique is presented and depends on whether there is a residual hallux valgus or whether the toe is well aligned. The operation should address the plane of the deformity and reverse the cause of the lengthening. Emphasis should however be placed in not getting the complication in the first instance and the incidence of the problematic short first metatarsal has significantly reduced since the decrease in popularity of the Wilson osteotomy

Background Bony or cartilaginous ossicles appear at the plantar aspect of the interphalangeal joint of the great toe. The variation in pattern, prevalence and anatomic relationships of these structures is not clearly established in the literature, especially in a Caucasian population. Without this knowledge, pathology at this joint may be underestimated and surgical approaches may be poorly planned particularly as radiographs underestimate the incidence of ossicles at this joint. The aims of this study were to determine the incidence and pattern of ossicles at this joint and to establish their anatomical relationships in order to aid planning the approach for their excision. Method The left great toe interphalangeal joint was dissected in forty British Caucasian cadavers and the pattern of ossicles and their anatomic relationships were established. Results In 27.5% of specimens, there was no identifiable ossicle and in these cases, the tendon of flexor hallucis longus was adherent to the joint capsule. In the remaining specimens (72.5%), a bursa separated the tendon of flexor hallucis longus from the plantar joint capsule and ossicles were found embedded within the joint capsule. Over a half (52.5%) of the specimens had a single ossicle located centrally within the plantar capsule and the remaining 20% had two ossicles lying within the capsule. Conclusion This study shows that a large proportion of the population have either one or two bony or cartilaginous ossicles at this joint. In addition, the study has clarified the anatomy of this joint and shown that, when present, ossicles do not lie within the tendon of flexor hallucis longus and could be most safely approached from either a medial or lateral approach

Introduction: Traditionally flexion deformities in Proximal Interphalangeal joints of lesser toes like hammer toes and curly toes are treated with fusing the PIP joint with a single Large Kwire. We describe a new technique of fusing PIP joints using two 1.1mm K wires. The advantages of this technique over single K wire are:. Less post operative complications like pain and pin tract infection. Achieving normal biomechanics of the foot by fixing the PIP joint at 15–20 degrees of flexion. Using two K wires gives more rotational stability of the toes and reduces the complications of over riding, under riding and hyperextension of the toes. 15–20 degrees flexion at PIP joint will give good digital purchase and push off in stance phase. As the K wire engages the cortex of proximal phalanx, there is almost negligible chance of loosening of K wires which is a common problem in large single K wire which usually is driven in to the medullary cavity of proximal phalanx. Aim: To compare the clinical and radiological outcomes in two pin fusions with standard single pin fusions described by Coughlin. To prove that this is a technically and biomechanical better procedure. Materials and Methods: Two pin technique was used for 36 PIP joint fusions in 25 patients with a mean age of 58 years (range–42 to 87 years) and female preponderance. Results were analysed using foot function scale, AOFAS (American Orthopaedic Foot and Ankle Society) lesser metatarsophalageal-Interphalageal scale. Post operative complications were documented. Technique: Dorsal skin incision was used to approach the PIP joint. Articular surfaces were prepared and two 1.1mm K wires were inserted from the tip of the toe and joint fixed in 15 – 20 degrees of flexion which is optimal functional position of PIP joint. Patients were mobilised non weight bearing for 6 weeks when K wires were removed and weight bearing started. Results: The results were analysed at 3–6 months post operatively. The foot function scores and objective parameters of AOFAS scores are slightly better in two pin fusions compared with single pin fusions. Objective parameters of AOFAS scale like adduction/ abduction, flexion, rotational deformities are significantly less with two wire fusions compared with single wire procedures (Coughlin et al). Radiological analysis of the foot showed that 97% had bony union compared 81% with single pin, and only 3% had fibrous union compared to 19% with single wire. Both the procedures didn’t have any non-unions. Only one patient had superficial wound infection, and surprisingly none had pin tract infection. Conclusion: Two pin PIP Joint fusion is relatively easy procedure with many technical advantages over single pin technique. The clinical and radiological outcomes are good. Results of the biomechanical studies should be available soon

The August 2012 Foot & Ankle Roundup³⁶⁰ looks at: calcaneocuboid distraction arthrodesis with allograft for acquired flatfoot; direct repair of the plantar plate; thromboembolism after fixation of the fractured ankle; weight loss after ankle surgery; Haglund’s syndrome and three-portal endoscopic surgery; Keller’s procedure; arthroscopy of the first MTPJ; and Doppler spectra in Charcot arthropathy.