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The outcome of olecranon and patella fractures fixed with biodegradable implants (self-reinforced poly-L-lactide wire combined with self-reinforced polyglycolide screw or self-reinforced poly-L-lactide plug) or with metallic implants (tension band wiring, Kirschner wire and metallic cerclage wire) was compared in a prospective, randomized study. Twenty-five olecranon fractures (15 with biodegradable implants and 10 with metallic ones) and 10 patella fractures (6 with biodegradable implants and 4 with metallic ones) were treated. There were no differences between these methods in outcome. Olecranon and patella fractures can be treated using biodegradable implants successfully. The total expenses are lower because a second operation is not needed to remove the implants after fracture consolidation.

In this experimental study with bone defects, we focussed on the one hand on external and internal osteogenic callus formation after filling the defect and on the other on the osteochondrogenic differentiation capacity of 4-day-old fibrous-like callus grafts and 12-day-old woven bone grafts in an osteogenic environment. A standard cortical bone defect of the femur was created in 95 young rats. The defect was filled with a cortical bone graft and 4- and 12-day-old callus grafts. The grafts were transplanted as such or in Nucleopore chambers. Follow-up was done at 1, 2, 3 and 6 weeks. The osteochondrogenic tissue formed was studied histologically and histomorphometrically. The results suggest that the filling of the bone defect had no influence on the primary external and internal osteogenic callus formation at 1 and 2 weeks. At 3 and 6 weeks in the chamber groups the persisting internal bridging woven bone was converted into more compact lamellar bone whereas periosteal callus remained at the edges of the defect. In the other groups at 3 and 6 weeks the normal shape of the cortex was reconstituting. Four-day-old fibrous-like callus formed bone in the Nucleopore chamber, indicating that fibrous-like callus tissue at 4 days contains osteogenic cells. Twelve-day-old callus consisting of woven bone was partially differentiated to cartilage, showing that woven bone contains cells capable of chondrogenic differentiation.

A patient who had had been treated by surgery for spinal echinococcosis in a Mediterranean country emigrated to northern Europe. After surgery, the echinococcosis disseminated and he developed chronic lytic and sinus-draining hydatid disease of the left hip and neuromuscular weakness of the left lower extremity. Seventeen years after the spinal surgery, he was referred to our hip service for a possible total hip replacement (THR) after receiving adequate chemotherapy against echinococcosis for nearly 3 years. Because of the poor results reported by others, we decided against THR; two of the four previous patients described in the current literature who had THR died due to complications.

The causes of a clinical tissue response to self-reinforced polyglycolide (SR-PGA) and self-reinforced polylactide (SR-PLLA) implants were studied in the first 2500 polymeric fixations. The incidence was 8.0% in fixations with implants made of SR-PGA (n = 1879) and 0% in SR-PLLA fixations (n = 621). A small number of fixations per site seemed to increase the incidence of a tissue response. In diagnoses involving over 50 fixations, except for ankle fractures, the incidence was 4.2%. The site of fixation influenced the incidence; the lowest incidence was seen for radial head fracture fixation (1.1%). The aromatic dye which has not been used since 1988 in the SR-PGA implant increased the response. A large total implant volume and a large number of implants increased the incidence of a tissue response. In the knee (n = 131), the incidence of a clinical tissue response was 4.3%, with four fluid accumulations and one synovitis of the knee after fixation with SR-PGA implants.

Osteotomies of the distal femur were fixed with two self-reinforced poly-L-lactic acid (SR-PLLA) plates and metallic screws placed through the plates on each side of the femur in 23 adult rabbits. They were followed-up after 3, 6, 12 and 24 weeks. After killing, radiological, histological, microradiographic and oxytetracycline fluorescence studies were performed. Except for one histologically confirmed fibrotic non-union at 24 weeks, the osteotomies healed, including one involving a rabbit which had suffered an ipsilateral femoral shaft fracture of unknown cause. No malformations were observed, and the macroscopically detected swelling was a normal postoperative reaction. This study showed that SR-PLLA plates implanted on both sides on the bone are suitable for the fixation of weight-bearing cancellous bone osteotomies in rabbits.

The economic costs of ankle fractures treated operatively with self-reinforced polyglycolide acid (SR-PGA) screws, with self-reinforced poly-L-lactide acid (SR-PLLA) screws or with metallic implants was determined. All patients were divided into three groups according to the fixation material used. Open and otherwise complicated fractures were excluded. The total expense of operations in each group was taken into account. The average total cost of an ankle fracture fixed with SR-PGA screws was Pounds 3503. In the SR-PLLA group it was Pounds 3906, and in the metallic group it was Pounds 4514. Total expenses were Pounds 1011 higher in the metallic group than in the SR-PGA group, and consequently, expenses in the metallic group were Pounds 608 higher than in the SR-PLLA group. According to this study, it seems that absorbable fixation devices are more economical than metallic implants in operative treatment of ankle fractures though as part of the differences in total expense in this series is due to the age of the patients and other dissimilarities between these groups, the results have to be interpreted carefully.