Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The treatment of displaced proximal humeral fractures with an angular and sliding stable antegrade nail (Targon-PH) led to good functional results, especially in 2- and 3-part fractures. There exists a substantial risk for postoperative complications and bad motor function in Neer IV/4 fractures. Lateral backing out of screws was abolished by implant modifications (PEEK-inlay) from 2003 onwards. Additional tension wire banding of the major tubercle may further reduce the risk of secondary displacement.

These findings suggest that the heel pad operates close to its pain threshold even at speeds encountered during barefoot walking and provides insight as to why barefoot runners may adopt "forefoot" strike patterns that minimize heel loading.

The results here may shed further light on the role of hypermobility of the first ray on hallux valgus deformity which could have implications for its surgical management.

BackgroundIt is often suggested that sagittal instability at the first tarso-metatarsal joint level is a primary factor for hallux valgus and that sagittal instability increases with the progression of the deformity. The assessment of the degree of vertical instability is usually made by clinical evaluation while any measurements mostly refer to a static assessment of medial ray mobility (i.e. the plantar/dorsal flexion in the sagittal plane). Testing methods currently available cannot attribute the degree of mobility to the corresponding anatomical joints making up the medial column of the foot. The aim of this study was to develop a technique which allows for a quantification of the in-vivo sagittal mobility of the joints of the medial foot column during the roll-over process under full weight bearing.MethodsMobility of first ray bones was investigated by dynamic distortion-free fluoroscopy (25 frames/s) of 14 healthy volunteers and 8 patients with manifested clinical instability of the first ray. A CAD-based evaluation method allowed the determination of mobility and relative displacements and rotations of the first ray bones within the sagittal plane during the stance phase of gait.ResultsTotal flexion of the first ray was found to be 13.63 (SD 6.14) mm with the healthy volunteers and 13.06 (SD 8.01) mm with the patients (resolution: 0.245 mm/pixel). The dorsiflexion angle was 5.27 (SD 2.34) degrees in the healthy volunteers and increased to 5.56 (SD 3.37) degrees in the patients. Maximum rotations were found at the naviculo-cuneiform joints and least at the first tarso-metatarsal joint level in both groups.ConclusionsDynamic fluoroscopic assessment has been shown to be a valuable tool for characterisation of the kinematics of the joints of the medial foot column during gait.A significant difference in first ray flexion and angular rotation between the patients and healthy volunteers however could not be found.