Age and ovariectomy impair both the normalization of mechanical properties and the accretion of mineral by the fracture callus in rats.

The impact of age and ovariectomy on the healing of femoral fractures was studied in three groups of female rats at 8, 32 and 50 weeks of age at fracture. In the two older groups, the rats had been subjected to ovariectomy or sham surgery at random at 26 weeks of age. At fracture, all rats received unilateral intramedullary pinning of one femur and a middiaphyseal fracture. Rigidity and breaking load of the femora were evaluated at varying times up to 24 weeks after fracture induction by three-point bending to failure. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. In the youngest group, 8-week-old female rats regained normal femoral rigidity and breaking load by 4 weeks after fracture. They exceeded normal contralateral values by 8 weeks after fracture. In the middle group, at 32 weeks of age, fractures were induced, and the femora were harvested at 6 and 12 weeks after fracture. At 6 weeks after fracture there was partial restoration of rigidity and breaking load. At 12 weeks after fracture, only the sham-operated rats had regained normal biomechanical values in their fractured femora, while the fractured femora of the ovariectomized rats remained significantly lower in both rigidity and breaking load. In contrast, for the oldest group of rats, 50 weeks old at fracture, neither sham-operated nor ovariectomized rats regained normal rigidity or breaking load in their fractured femora within the 24 weeks in which they were studied. In all fractured bones, there was a significant increase in BMD over the contralateral intact femora due to the increased bone tissue and bone mineral in the fracture callus. Ovariectomy significantly reduced the BMD of the intact femora and also reduced the gain in BMD by the fractured femora. In conclusion, age and ovariectomy significantly impair the process of fracture healing in female rats as judged by measurements of rigidity and breaking load in three-point bending and by accretion of mineral into the fracture callus.

Anterior cervical foraminotomy and fusion. Surgical technique and results.

STUDY DESIGN: This study retrospectively reviewed the clinical and radiographic results of a series of patients who underwent osteophyte resection during anterior discectomy and fusion. OBJECTIVE: To determine whether resection of the posterior uncinate process at the time of anterior cervical discectomy is safe and effective. SUMMARY OF BACKGROUND DATA: Previous studies have described techniques of osteophyte resection, but safety and outcome have not been supported by a clinical series of patients. METHODS: Forty-three consecutive patients with radiculopathy due to spondylosis or lateral herniated nucleus pulposus had 68 foraminotomies done at the time of anterior cervical disc foraminotomy for radiculopathy. All patients were followed-up until radiographic union. All patients were examined, and Odom's criteria were used to assess postoperative pain and function in the neck, arm, and iliac donor site. RESULTS: The results were consistent with previous reports of anterior cervical disc foraminotomy for radiculopathy. Excellent and good results occurred in 77% and 14% of the patients, respectively. Three patients had no relief and no patient had worsening of radiculopathy. The fusion rate was 93%. Thirty-one patients (72%) reported being very satisfied. Three patients required a re-operation--one for bone graft dislodgment and two for pseudoarthrosis. No vascular injuries occurred. CONCLUSIONS: Resection of the posterior portion of the uncinate process to remove osteophytes that narrow the neural foraman or to allow direct visualization of laterally herniated disc material can be done safely. When combined with an autogenous interbody bone graft, good results can be expected.

Technique and results of allograft reconstruction in revision total knee arthroplasty.

This study reports more than four years of experience with bone allografts used to reconstruct large uncontained defects in the femur and the tibia in patients requiring revision total knee arthroplasty. Nineteen allografts were used, 13 in the distal femur and six in the proximal tibia. The average follow-up period was 2.1 years. After these complex revision arthroplasties, the average knee score improved from 29 to 87 points. The average patient function score increased from 35 to 85 points. Bulk allografts are effective in the reconstruction of uncontained defects in revision total knee arthroplasty.

Cementless total knee arthroplasty in juvenile onset rheumatoid arthritis.

Twenty-two total knee arthroplasties with at least one cementless component were performed in 14 patients with juvenile rheumatoid arthritis (JRA) from 1985 to 1989. All 22 femoral components and ten tibial components were implanted cementless. The mean age at operation was 26 years. All 14 patients were available for follow-up evaluation at an average of 3.9 years (range, two to 6.2 years). Using The Knee Society's scoring system, the knee score improved from an average of 18 points (range, 0-47 points) preoperatively to 92 points (range, 58-100 points) at follow-up evaluation. The functional score improved from 28 points (range, 0-55 points) to 76 points (range, 40-100 points). Nonprogressive radiolucencies of less than 1 mm were observed in two knees. One reoperation was performed for failure of a metal-backed patellar component. Knee arthroplasty with cementless components in selected JRA patients can give results comparable with a fully cemented knee at the two- to six-year follow-up evaluation.