Crystallization study and comparative in vitro-in vivo hydrolysis of PLA reinforcement ligament.

In the present work, the crystallization behavior and in vitro-in vivo hydrolysis rates of PLA absorbable reinforcement ligaments used in orthopaedics for the repair and reinforcement of articulation instabilities were studied. Tensile strength tests showed that this reinforcement ligament has similar mechanical properties to Fascia Latta, which is an allograft sourced from the ilio-tibial band of the human body. The PLA reinforcement ligament is a semicrystalline material with a glass transition temperature around 61 °C and a melting point of ~178 °C. Dynamic crystallization revealed that, although the crystallization rates of the material are slow, they are faster than the often-reported PLA crystallization rates. Mass loss and molecular weight reduction measurements showed that in vitro hydrolysis at 50 °C initially takes place at a slow rate, which gets progressively higher after 30-40 days. As found from SEM micrographs, deterioration of the PLA fibers begins during this time. Furthermore, as found from in vivo hydrolysis in the human body, the PLA reinforcement ligament is fully biocompatible and after 6 months of implantation is completely covered with flesh. However, the observed hydrolysis rate from in vivo studies was slow due to high molecular weight and degree of crystallinity.

Elongation of the femoral neck in Perthes disease.

We present the long-term clinical and radiological results of a series of 168 young patients with unilateral Perthes disease who were treated in our department between 1989 and 1997, using a combined osteotomy in the longitudinal and horizontal axis of the proximal femur and elongation of the femoral neck. Surgical treatment was undertaken for any group II (Catterall's classification) patient, with the presence of two or more radiographic signs of the "head at risk" and the clinical sign of flexion with abduction, as well as for all cases classified by Catterall as groups III and IV. The surgical procedure we describe provided 147 radiologically and clinically normal hips in the short and long-term. However, in the long-term, 21 out of 168 patients presented with residual deformities such as shallow acetabulum, thickening of the acetabular floor, coxa magna, thicker and slightly shorter femoral neck. Thus for the vast majority of patients, the operation we describe here provided leg length equalisation and restored the working length of the abductors by maintaining the tip of the greater trochanter at the same level as on the unaffected side.

Chronic osteomyelitis of the pelvis in children and adolescents.

Osteomyelitis of the pelvis is rare in children as well as in adults. This explains why the diagnosis is often missed, so that the infection becomes chronic. The authors report five chronic paediatric cases, seen between 1993 and 2003. The diagnosis was initially missed in two patients. In two others, the osteomyelitis was recognised but insufficiently treated, so that it also became chronic. The fifth patient developed exogenous osteomyelitis 6 months after an open pelvic fracture. The bone scan was useful for the differential diagnosis, but laboratory and radiographic findings were not. Treatment was the same for all patients, including wide surgical debridement, antibiotic therapy and prolonged immobilisation. Four patients were free of symptoms at the last clinical evaluation, after an average follow-up period of 7 years. Only one patient had a recurrence 3 months postoperatively and was re-operated. This study demonstrates that surgical treatment of chronic pelvic osteomyelitis in children and adolescents yields encouraging results.

Primary total-hip arthroplasty with the autophor 900-s fully porous coated stem in young patients seven to seventeen years of follow-up.

A total of 233 Autophor 900-S fully porous coated stems were implanted in 220 patients with an average age of 47.5 years and an average follow-up of 13.5 years. The mean d' Aubigne-Postel score improved from 7.9 points preoperatively to 16.9 points postoperatively (P < .001). The overall result was excellent in 74.6%, good in 18.1%, fair in 5.8%, and poor in 1.5% of cases. One hip was revised for septic and two for aseptic loosening. The overall survival rate of this prosthesis was 98.1% in 17 years. The Autophor 900-S femoral stem has offered a very satisfactory clinical outcome together with considerable prosthesis longevity in the young patient population studied. It combines adequate initial stability, satisfactory subsequent bone ingrowth, smooth load transfer, and low-friction bearing surfaces.

Antegrade interlocking nailing of humeral shaft fractures.

The results of 39 humeral shaft fractures (37 patients) treated with antegrade locked nailing using a Russell-Taylor nail were reviewed. There were 30 acute fractures, 6 fractures malaligned in a hanging cast or brace, and 3 pathological fractures. Patient age ranged from 26 to 80 years (average, 59.7 years) and average follow-up was 25.7 months (range, 6-48 months). Fracture union was achieved in 92.3% of our cases, while shoulder function was excellent or good in 87.2% of cases. Antegrade locked nailing offers a dependable solution for the treatment of humeral shaft fractures, especially in polytrauma patients and cases of segmental or pathological fractures. Far less satisfactory results were obtained in comminuted fractures of the proximal third in the humerus, especially in osteoporotic patients, and we therefore advocate caution with the use of intramedullary nailing in this type of fracture. Certain technical aspects such as avoiding nailing the fracture in distraction, properly countersinking the tip of the nail, and achieving adequate fixation stability have been found to be of paramount importance to reduce the incidence of delayed union/non-union rate and to obtain better functional results from the shoulder joint.