Teruhisa Yamashiro

Osteosarcoma around the knee: Intraepiphyseal excision and biological reconstruction with distraction osteogenesis

In 11 patients juxta-articular osteosarcoma around the knee was treated by intraepiphyseal excision of the tumour and reconstruction of the bone defect by distraction osteogenesis. Preoperative and postoperative chemotherapy was given to eight patients with high-grade tumours. The articular cartilage of the epiphysis and a maximum of healthy soft tissues were preserved. Distraction osteogenesis was then carried out. The mean gain in length was 9.7 cm. Full function of the limb was preserved in all except one patient, with a mean follow-up of 53.8 months. Treatment of juxta-articular osteosarcomas around the knee with joint preservation and biological reconstruction using distraction osteogenesis can give excellent functional results.

Effects of timing of low-intensity pulsed ultrasound on distraction osteogenesis

We investigated the effects of low‐intensity pulsed ultrasound (LIPUS; 30 mW/cm2 spatial and temporal average) on the timing of LIPUS treatment in distraction osteogenesis. Lengthening of the right tibia was performed in 75 male Japanese white rabbits using unilateral fixators (waiting period, 7 days; distraction rate, 1.5 mm/day; distraction period, 7 days). Rabbits were divided into four groups according to the timing of the LIPUS treatment. Control group had no stimulation. Waiting group was treated with a daily 20‐min session of LIPUS during a 7‐day latency period. Lengthening group was treated during the lengthening period. Maturation group was treated for the first 7 days after completion of distraction. We evaluated the distraction site by radiography and histology every week for 4 weeks. Bone mineral density (BMD) and mechanical strength were tested and microfocus X‐ray computed tomography was performed on specimens 2 weeks after completion of distraction. The lengthening group had greater BMD and mechanical strength than the other groups, bone regeneration was enhanced more in the maturation group than in the control or waiting groups. Histologically, endochondral bone formation in the lengthening and the maturation groups occurred earlier than in the control or waiting groups. These results suggest the LIPUS effect is mediated via endochondral pathways. We concluded that LIPUS stimulates bone formation in distraction osteogenesis and is most effective during the lengthening phase.

Reconstruction with Distraction Osteogenesis for Juxta-articular Nonunions with Bone Loss

BACKGROUND Nonunions of a juxta-articular lesion with bone loss, which represent a challenging therapeutic problem, were treated using external fixation and distraction osteogenesis. METHODS Seven juxta-articular nonunions (five septic and two aseptic) were treated. The location of the nonunion was the distal femur in four patients, the proximal tibia in one patient, and the distal tibia in two patients. All of them were located within 5 cm from the affected joints. Preoperative limb shortening was present in six cases, averaging 2.9 cm (range, 1-7 cm). The reconstructive procedure consisted of refreshment of the nonunion site, deformity correction, stabilization by external fixation, and lengthening to eliminate leg length discrepancy or to fill the defect. Shortening-distraction was applied to six patients and bone transport to one patient for reconstruction. Intramedullary nailing to reduce the duration of external fixation was simultaneously performed in two cases. All the patients had at least 1 year of follow-up evaluation. RESULTS Osseous union without angular deformity or leg length discrepancy greater than 1 cm was achieved in all patients. The mean amount of lengthening was 5.8 cm (range, 2.2-10.0 cm). The mean external fixation period was 219 days (range, 98-317 days), and the mean external fixation index was 34.4 days/cm (range, 24.5-47.6 days/cm). All patients reported excellent pain reduction. There were no recurrences of infection in five patients with prior history of osteomyelitis. The functional results were categorized as excellent in two, good in three, and fair in two. CONCLUSION Despite the length of postoperative external fixation, distraction osteogenesis can be a valuable alternative for the treatment of juxta-articular nonunions.

Osteosarcoma around the knee

In 11 patients juxta-articular osteosarcoma around the knee was treated by intraepiphyseal excision of the tumour and reconstruction of the bone defect by distraction osteogenesis. Preoperative and postoperative chemotherapy was given to eight patients with high-grade tumours. The articular cartilage of the epiphysis and a maximum of healthy soft tissues were preserved. Distraction osteogenesis was then carried out. The mean gain in length was 9.7 cm. Full function of the limb was preserved in all except one patient, with a mean follow-up of 53.8 months. Treatment of juxta-articular osteosarcomas around the knee with joint preservation and biological reconstruction using distraction osteogenesis can give excellent functional results.

Ilizarov Technique for Correction of the Shepherd's Crook Deformity: A Report of Two Cases

We report 2 patients with fibrous dysplasia who underwent correction, using the Ilizarov technique, of Shepherds crook deformities and pathological fractures of the left femurs. A 12-year-old boy underwent an opening wedge osteotomy and a 48° gradual correction, whereas a 43-year-old woman underwent a 34° acute correction without osteotomy at the fracture site. Both patients could initiate early weight bearing. Final leg function was excellent and alignment was maintained. No complications were encountered. Both patients had no difficulty sleeping and no major complaints about the Ilizarov technique. It is more important to achieve accurate alignment than resection of the lesion. The Ilizarov technique is effective for treating the Shepherds crook deformity in patients with fibrous dysplasia.