Transverse laxity of the forefoot.

BACKGROUND: Splay of the forefoot reflects the loss of tension in the soft tissues and indicates failure of the biomechanics of the tie-bar system. By identifying and quantifying the soft tissue structures involved in the destruction of forefoot stability we could increase the understanding of forefoot pathologies. METHODS: We investigated the transverse forefoot laxity on healthy feet, feet with forefoot pathology and cadaveric feet undergoing sequential dissection. RESULTS: Statistical difference in transverse laxity was seen between healthy feet (n = 160) and feet with symptomatic forefoot pathology requiring surgery (n = 29). Presence of lesser ray pathology is associated with increased transverse laxity. For the dissected cadaveric feet (n = 9) sequential sectioning the plantar plate causes a progressive evolution of transverse laxity. The repair of plantar plates greatly improves transverse stability. CONCLUSIONS: Forefoot pathology causes increased transverse laxity. In case of a major transverse laxity of the forefoot a plantar plate lesion should be suspected.

Metatarsophalangeal HAPY® spherical pyrocarbon implant: Technical note.

We present a new arthroplasty concept for the first metatarsophalangeal joint (MTP1) involving the HAPY® pyrocarbon interposition implant. This is a spherical implant that does not integrate into bone. Instead, the goal is to achieve gliding of the implant on the bone/cartilage to maintain the function and mobility of the MTP1 joint. We describe the surgical technique used for its implantation. Since the implant is not anchored into bone, it is stabilized in a spherical cavity hollowed out in the metatarsal head. In a preliminary study of 22 cases with a mean follow-up of 36 (20-79) months, the mean AOFAS score improved from 64 (35-72) preoperatively to 91 (47-100) postoperatively (p<0.05). At the final assessment, no subchondral cyst or osteolysis was visible.

Reliability of hindfoot alignment measurements from standard radiographs using the methods of Meary and Saltzman.

BACKGROUND: Few methods have been described for measuring hindfoot alignment from an anteroposterior view. The objective of this study was to compare two methods of angular measurement based on the views of Meary and Saltzman. METHODS: Thirty asymptomatic volunteers were included. Four radiographs were performed: the views of Meary and Saltzman with parallel feet and with the Fick correction. The reproducibility was determined by the inter- and intraobserver variability (ICC). RESULTS: Meary's method revealed a mean valgus angulation of 3.9° (SD 3.47°). The reliability was extremely variable with a mean ICC of 0.59. The best reproducibility was obtained with Meary's method with and without Fick correction. CONCLUSION: The results of this study show that the reliability of the angular measurements depends on the radiographic view and measurement method chosen. The lateral Fick correction did not counteract the influence of tibial rotation. The same method should be used consistently.

Forefoot morphotype study and planning method for forefoot osteotomy.

In the reconstruction of the hip, knee, or any other joint, preoperative planning is necessary for avoiding mistakes during surgery. Since 1995, the authors have been doing this before forefoot surgery to increase the accuracy of the surgery. As much as possible, they try to correct only the lesion and to avoid preventive or extensive surgery on adjacent rays, except if the correction leads to a modified dysharmonious new morphotype with high risk of transfer lesion. The tolerance length seems to be 2 mm, particularly on the middle metatarsals (M2 and M3). This surgery should be performed only if the midfoot and backfoot are correct and if the gastrocnemius muscle has been checked on to eliminate a retraction needing stretching exercises before and generally after surgery.