Primary uncemented Harris-Galante acetabular components in patients 50 years old or younger: results at 10 to 12 years.

Seventy-three patients (84 hips) 50 years or younger were treated with primary total hip arthroplasty using the Harris-Galante uncemented acetabular component. At a median followup of 10 years, there were seven acetabular metal shell revisions: five for osteolysis and one each for aseptic loosening and dislocation. There were 10 polyethylene exchanges without metal acetabular shell removal. None of the unrevised acetabular components was radiographically loose, but eight had pelvic osteolysis. The rate of 10-year survival without revision of the acetabular metal shell was 87.9% (95% confidence interval, 80.1%-95.7%). The same rate of survival without revision for aseptic acetabular component loosening was 97.3% (95% confidence interval, 92.9%-100%). Revision for aseptic acetabular loosening or polyethylene liner exchange or both was 84.5% (95% confidence interval, 75.8%-93.4%).

Long-term results of total hip arthroplasty for femoral neck fracture nonunion.

BACKGROUND: Hip arthroplasty for the treatment of nonunion at the site of a femoral neck fracture has provided good short-term results. The purpose of the present study was to evaluate the long-term results and complications of total hip arthroplasty for the treatment of femoral neck nonunion. METHODS: The records of ninety-nine patients who had been managed with total hip arthroplasty with use of a cemented Charnley acetabular component and a cemented Charnley monoblock femoral component for the treatment of a femoral neck nonunion were retrospectively reviewed. The average age at the time of the arthroplasty was sixty-eight years. Eighty-four patients (85%) were followed until death, revision, or component removal or for at least two years (mean, 12.2 years) postoperatively. RESULTS: Twelve patients were treated with revision (eleven) or resection arthroplasty (one), eleven were lost to follow-up, and four died less than two years postoperatively. Of the remaining seventy-two unrevised hips that were followed for at least two years, sixty-nine (96%) had no or mild hip pain at the time of the last follow-up. The rate of component survival free of revision or removal for any reason was 93% at ten years and 76% at twenty years. The risk factors that were significantly associated with revision for aseptic loosening included an age of less than sixty-five years at the time of the arthroplasty (p = 0.045), a body-mass index of >/=30 (p < 0.01), and male gender (p = 0.02). The second most common complication after loosening was dislocation, which occurred in nine patients (9%). CONCLUSIONS: Total hip arthroplasty is an effective method for the treatment of nonunion of the femoral neck and provides satisfactory long-term results. However, the rate of implant survival is poorer than that reported in most other studies of Charnley total hip arthroplasty in the general population.

Levofloxacin and trovafloxacin inhibition of experimental fracture-healing.

We previously have shown that experimental fractures exposed to ciprofloxacin have diminished fracture healing. The purpose of this study was to assess the effect of levofloxacin and trovafloxacin on experimental fracture healing to test the hypothesis that diminished fracture healing is a quinolone class effect. Sixty-one male Wistar rats were divided into three groups, which received 25 mg/kg of levofloxacin twice daily for 3 weeks, 35 mg/kg of trovafloxacin twice daily for 3 weeks, or no treatment, beginning 7 days after production of closed, nondisplaced, bilateral femoral fractures. The mean peak serum concentrations of levofloxacin and trovafloxacin drawn 30 minutes after administration were 6.9 and 7.0 microg/mL, respectively. Radiographic, histologic, and biomechanical studies were used to evaluate fracture healing. Torsional strength testing of fracture callus exposed to levofloxacin and trovafloxacin revealed a decrease in strength (299 and 257 N-mm, respectively) as compared with controls (364 N-mm). Radiographs revealed significantly more advanced healing in control animals (Goldberg score of 2.1) compared with the fractures in the rats treated with levofloxacin and trovafloxacin (Goldberg score of 1.5 in both groups). Fracture calluses in the animals treated with levofloxacin and trovafloxacin showed a lower histologic grade (5.3 and 3.5, respectively) as compared with control animals (7.5) representing a less mature callus with the presence of more cartilage and less woven bone. These data suggest that experimental fractures systemically exposed to levofloxacin or trovafloxacin have diminished healing during the early stages of fracture repair. The administration of quinolones during early fracture repair may compromise fracture healing in humans.

Placement of half-pins for supra-acetabular external fixation: an anatomic study.

An alternative location for placement of half-pins during pelvic external fixation is the dense supra-acetabular bone in the region of the anterior-inferior iliac spine. Although these fixators have gained popularity, to the authors' knowledge there are no studies evaluating the potential anatomic risks of placement of half-pins in this area; no safe corridors have been defined. Additionally, pins are placed near the hip capsule and no studies exist defining the superior extent of the hip capsule which potentially may be violated by placing half-pins in this location. The purposes of the current study were to evaluate the neurovascular risks and accuracy of fluoroscopically guided percutaneous placement of supra-acetabular half-pins, and to evaluate the anatomic superior extent of the hip capsule. Ten fresh frozen cadaveric pelves were used. A 5-mm half-pin was placed in the supra-acetabular bone under fluoroscopic guidance. Iliofemoral dissection was done and the proximity of the half-pin to local neurovascular risks was measured with a caliper. The hip capsule was exposed and the superior extent of the hip capsule was measured. Intraosseous pin placement was evaluated by direct observation. Nine pins were completely in bone, one had partially exited posteriorly and laterally. The lateral femoral cutaneous nerve was at risk with a mean distance of 10 mm (range, 2-25 mm) from the half-pins. The femoral nerve and femoral artery were not at risk. The average superior extent of the hip capsule was 16 mm above the joint (range, 11-20 mm). Half-pins can be placed accurately and safely in the supra-acetabular region using percutaneous techniques, appropriate soft tissue sleeves, and fluoroscopic guidance. Insertion of pins at least 2 cm above the hip is recommended to avoid potential hip capsule penetration.

Revascularization of nerve grafts: a qualitative and quantitative study of the soft-tissue bed contributions to blood flow in canine nerve grafts.

Blood flow to canine saphenous nerve grafts either in contact with a healthy soft-tissue bed or isolated from the soft-tissue bed by entubulation was quantitated at 3, 7, 14, and 28 days after surgery with radionuclide-labeled microspheres and evaluated histomorphometrically. At 3 days there was no statistical difference between the 2 techniques in regard to nerve graft blood flow, and neither group had blood flow in the middle portion of the graft. In contrast, analysis at 7, 14, and 28 days found blood flow in the middle segments of the nonisolated conventional nerve grafts to exceed that of entubulated nerve grafts with evidence in these segments of both lateral and longitudinal revascularization. The results of this investigation support an important role for the soft-tissue bed in nerve graft revascularization and suggest that neovascularization from the soft-tissue bed is the primary mechanism for restoration of blood flow in such grafts.