Congenital pseudarthrosis of the clavicle: a case report.

Congenital pseudarthrosis of the clavicle is a rare entity of unknown aetiology. Its pathogenesis is related to the embryology of the clavicle. We present a 6-year-old girl with congenital pseudarthrosis of the right clavicle. A prominence was noticed at birth between the middle and distal ends of the clavicle that increased in size when the right shoulder was actively mobilised. Radiographic examination revealed a hypertrophic pseudarthrosis of the clavicle. The pseudarthrosis was resected and the clavicular segments were fixed with an external fixator for 2 months until union. Clinical results were excellent at the 7-year follow-up: the right shoulder was pain-free and the appearance satisfactory. Surgical treatment of congenital pseudarthrosis of the clavicle in children using an external fixator provides a better cosmetic outcome with smaller postoperative scars and avoids a second surgical procedure to remove the implants.

The role of the dorsal vertebral cortex in the stability of transpedicular screws. A biomechanical study in human cadaveric vertebrae.

The aim of this biomechanical study was to investigate the role of the dorsal vertebral cortex in transpedicular screw fixation. Moss transpedicular screws were introduced into both pedicles of each vertebra in 25 human cadaver vertebrae. The dorsal vertebral cortex and subcortical bone corresponding to the entrance site of the screw were removed on one side and preserved on the other. Biomechanical testing showed that the mean peak pull-out strength for the inserted screws, following removal of the dorsal cortex, was 956.16 N. If the dorsal cortex was preserved, the mean peak pullout strength was 1295.64 N. The mean increase was 339.48 N (26.13%; p = 0.033). The bone mineral density correlated positively with peak pull-out strength. Preservation of the dorsal vertebral cortex at the site of insertion of the screw offers a significant increase in peak pull-out strength. This may result from engagement by the final screw threads in the denser bone of the dorsal cortex and the underlying subcortical area. Every effort should be made to preserve the dorsal vertebral cortex during insertion of transpedicular screws.

Avulsion fractures of the lateral tibial condyle in children.

Avulsion fractures of the lateral tibial condyle are very rare in children and adolescents. Seven patients were treated between 1986 and 2000. They were all involved in sporting activities and an acute contraction of the fibres of the iliotibial band was considered to be their common pathogenetic factor. A subdivision in two types of avulsion fractures according to the anatomic location of the lesion was used. The Segond fracture, a small vertical avulsion fracture involving the midportion of the lateral tibial condyle distal to the plateau but proximal to the physis, was diagnosed in five patients. In two of them it was associated with a fracture of the anterior intercondylar eminence. The avulsion fracture of the Gerdy's tubercle was diagnosed in two other patients. The detached fragment was bigger, more anterior and involved a part of the articular surface of the lateral tibial plateau as well as a part of the physeal plate. All patients were treated conservatively and were free of symptoms after a mean follow-up of 9 years.

Talonavicular dislocation and nondisplaced fracture of the navicular.

Dislocation of the talonavicular joint is rare. We report a case of talonavicular dislocation in a 24-year-old man associated with a nondisplaced fracture of the navicular. Closed reduction was achieved, followed by 4 weeks in a cast. After 2 years of follow-up, no complications have been reported. This patient is still successfully employed as a manual worker 2 years after injury.

Total hip arthroplasty in neglected congenital dislocation of the hip.

Between 1984 and 1995, 74 total hip replacements were performed in 64 adult patients who had painful untreated congenital dislocation of the hip. The arthroplasty was performed in the position of the true acetabulum in all patients who had either high or low congenital dislocations of the hip. The femoral head was positioned in the true acetabulum after either osteotomy of the greater trochanter or shortening of the femur, or progressively using external fixation. Information was available on all patients with a followup of 1 to 11 years (mean, 7.2 years). Of the 74 replaced hips, 70 showed marked improvement concerning pain, gait, and mobility, according to the Merle D'Aubigne and Postel scale. Four hips were revised with satisfactory results. The reason for revision was infection in one case and loosening of the plastic cup in three cases. Shortening of the femur by removing a segment of bone below the level of the lesser trochanter followed by osteosynthesis without osteotomy of the greater trochanter was found to be the best method for treating bilateral and several unilateral high congenital dislocation of the hip.

Humeral head torsion in recurrent anterior dislocation of the shoulder.

We measured torsion of the humeral head in 38 patients (40 shoulders) with recurrent anterior dislocation of the shoulder (RADS) and in 40 normal subjects. We found a reduced mean retroversion in the patients with RADS at 4.3 +/- 10.56 degrees (17 degrees anteversion to 32 degrees retroversion) as compared with 16.1 +/- 11.07 degrees in the control group (0 degrees to 49 degrees) (p = 0.0001). There was anteversion in 11 of the 40 shoulders in the RADS group (27.5%) and in none of the control group. The first dislocation had occurred after minimal force in 18 of 25 patients with less than 10 degrees retroversion, but in only three of 15 with over 10 degrees retroversion. We conclude that decreased retroversion of the humeral head is often associated with RADS and with first dislocation of the shoulder caused by minimal force.