Aims: A study was undertaken using foot pressure analysis, to assess the biomechanical outcomes following calcaneal fractures using the HR Mat and to assess their correlation with function.

Methods: Twenty four individuals who had been treated for unilateral, intra-articular comminuted calcaneal fractures performed 4 walking trials. 14 patients had operative treatment and 10 were treated conservatively.

Results: There was significant restriction in subtalar and ankle movements on the affected side in both groups. Peak pressures in the midfoot and fifth metatarsal head were significantly higher in the injured foot compared to the normal side. Peak values of forces transmitted by the fractured foot were significantly lower (ANOVA < 0.001). Hindfoot movements, foot pressure and force measurements did not correlate with the AOFAS and Bristol scores.

Conclusions: Calcaneal fractures cause significant alteration of loading in the foot. Altered loading patterns do not appear to have an influence on the functional outcome.

This study evaluated the effect on movement under load of three different techniques for re-attachment of the tuberosities of the humerus using test sawbones. In the first, the tuberosities were attached both to the shaft and to each other, with one cerclage suture through the anterior hole in the prosthesis. The second technique was identical except for omission of the cerclage suture and in the third the tuberosities were attached to the prosthesis and to the shaft. An orthogonal photogrammetric system allowed all segments to be tracked in a 3D axis system. The humeri were incrementally-loaded in abduction, and the 3D linear and angular movements of all segments were calculated. Displacement between the tuberosities and the shaft was measured.

The first and second techniques were the most stable constructs, with the third allowing greater separation of fragments and angular movement. Separation at the midpoint of the tuberosities was significantly greater using the latter technique (p < 0.05). The cerclage suture added no further stability to the fixation.

The purpose of this study was to evaluate the effect on movement under load of different techniques of reattachment of the humeral tuberosities following 4-part proximal humeral fracture.

Biomechanical test sawbones were used. 4-part fracture was simulated and a cemented Neer3 prosthesis inserted. Three different techniques of reattachment of the tuberosities were used – 1)tuberosities attached to the shaft, and to each other through the lateral fins in the prosthesis with one cerclage suture through the anterior hole in the prosthesis, 2)as 1 without cerclage suture, and 3)tuberosities attached to the prosthesis and to the shaft. All methods used a number 5 ethibond suture. Both tuberosities and the shaft had multiple markers attached. Two Digital cameras formed an orthogonal photogrammetric system allowing all segments to be tracked in a 3-D axis system. Humeri were incrementally loaded in abduction using an Instron machine, to a minimum 1200N, and sequential photographs taken. Photographic data was analysed to give 3-D linear and angular motions of all segments with respect to the anatomically relevant humeral axis, allowing intertuberosity and tuberosity-shaft displacement to be measured.

Techniques 1 and 2 were the most stable constructs with technique 3 allowing greater separation of fragments and angular movement. True intertuberosity separation at the midpoint of the tuberosities was significantly greater using technique 3 (p< 0.05). The cerclage suture used in technique 2 added no further stability to the fixation.

In conclusion, our model suggests that the most effective and simplest technique of reattachment involves suturing the tuberosities to each other as well as to the shaft of the humerus. The cerclage suture appears to add little to the fixation in abduction, although the literature would suggest it may have a role in resisting rotatory movements.