Osteolysis of the femur: principles of management.

Femoral osteolysis is and will remain an important cause of THA failures. The presentation is initially radiographic and patients may or may not become symptomatic. If so, pain is the most common symptom. Infection is the most common differential diagnosis and must be excluded. Osteolysis is usually progressive and may eventually lead to loss of implant fixation, implant fracture, or periprosthetic fracture. Multiple factors influence the decision to revise a femoral component, including the degree and type of bone loss, the rate at which it is progressing, the potential for fracture, the degree of symptoms, especially pain, and the activity level and general health of the patient. There are many options for revising failed femoral stems, each with varying degrees of success. The choice of technique and prosthesis used in the revision can be guided by a simple bone defect classification presented in this chapter. Revision of femoral components in these patients can be fraught with complications and poor results; hence, the importance of preoperative planning cannot be overemphasized.

Proximal femoral allografts for reconstruction of bone stock in revision arthroplasty of the hip. A nine to fifteen-year follow-up.

BACKGROUND: Revision of a femoral component in a patient who has severe bone loss is a complex problem that is likely to increase with the increasing numbers of patients who have multiple revision hip arthroplasties. A valuable option in such a situation is use of a long-stem prosthesis that is cemented to a proximal femoral allograft but not to the host bone. METHODS: Between April 1984 and December 1989, sixty-three total hip arthroplasties in sixty consecutive patients were revised with a proximal femoral allograft-prosthesis construct. The average length of the allograft was 15 cm. The average age of the patients at the time of the revision was 62.5 years. All patients had undergone at least one previous total hip arthroplasty, and an average of 3.8 previous total hip arthroplasties had been performed in the series. Each patient was assigned a modified Harris hip score. Radiographs were examined for trochanteric union, allograft-host union, endosteal and periosteal resorption, component loosening, and fracture. RESULTS: At an average of eleven years (range, nine years and four months to fifteen years) after the revision, forty-five patients were alive, fourteen patients had died, and one patient had been lost to follow-up. The patients who had died or had been lost to follow-up had had a total of fifteen allografts (24%) and had been followed for an average of five years and seven months (range, two years and four months to eight years). The average preoperative Harris hip score for the sixty-three hips was 30 points (range, 6 to 65 points). At the latest follow-up evaluation, the average score for the hips with the original graft in situ was 71 points (range, 47 to 95 points). Five hips failed because of infection, and four of them were successfully revised. Three hips failed because of aseptic loosening, at an average of ten years and three months; two were successfully revised, and the third was awaiting revision at the time of writing. An additional operation was performed in three hips with allograft-host nonunion and in two with dislocation. Success was defined as a postoperative increase in the Harris hip score of greater than 20 points, a stable implant, and no need for additional surgery related to the allograft at the time of the review. The success rate for all hips was 78% (forty-nine of sixty-three) after an average of nine years of follow-up. The success rate for the patients who were alive at the time of follow-up was 77% (thirty-seven of forty-eight hips) after an average of eleven years of follow-up. CONCLUSIONS: The clinical and radiographic results at an average of eleven years after revision hip arthroplasty with a proximal femoral allograft are encouraging. This report represents our early experience; improvements in the technique have been made. We believe that this technique provides a viable option for treatment of the difficult problem of severe femoral bone loss.

Extensile exposures for revision hip arthroplasty.

Revision arthroplasty is being performed with increasing frequency and the cases are becoming increasingly complex. A key component to successful revision surgery is the surgical exposure. This is influenced by the surgeon's experience, the reason for revision, the type of components to be revised, the type of bone defects, and the previous exposures used. In simple revisions one of the standard hip approaches with which the surgeon is familiar often will suffice. However, with more complex cases an extensile or specialized approach may be necessary. No one approach is suitable for all cases and the surgeon must be familiar with several approaches, their relative indications, and possible complications.

Treatment of giant-cell tumors of long bones with curettage and bone-grafting.

BACKGROUND: The use of curettage, phenol, and cement is accepted by most experts as the best treatment for giant-cell tumor of bone. The present study was performed to evaluate whether equivalent results could be obtained with curettage with use of a high-speed burr and reconstruction of the resulting defect with autogenous bone graft with or without allograft bone. METHODS: The prospectively collected records of patients who had a giant-cell tumor of a long bone were reviewed to determine the rate of local recurrence after treatment with curettage with use of a high-speed burr and reconstruction with autogenous bone graft with or without allograft bone. All of the patients were followed clinically and radiographically, and a biopsy was performed if there were any suspicious changes. RESULTS: Fifty-nine patients met the criteria for inclusion in the study. According to the grading system of Campanacci et al., two patients (3 percent) had a grade-I tumor, twenty-nine (49 percent) had a grade-II tumor, and twenty-eight (47 percent) had a grade-III tumor. Seventeen patients (29 percent) had a pathological fracture at the time of presentation. The mean duration of follow-up was eighty months (range, twenty-eight to 132 months). Seven patients (12 percent) had a local recurrence. Six of these seven were disease-free at the latest follow-up examination after at least one additional treatment with curettage or soft-tissue resection (one patient). One patient had resection and reconstruction with a prosthesis after a massive local recurrence and pulmonary metastases. CONCLUSIONS: Despite the high rates of recurrence reported in the literature after treatment of giant-cell tumor with curettage and bone-grafting, the results of the present study suggest that the risk of local recurrence after curettage with a high-speed burr and reconstruction with autogenous graft with or without allograft bone is similar to that observed after use of cement and other adjuvant treatment. It is likely that the adequacy of the removal of the tumor rather than the use of adjuvant modalities is what determines the risk of recurrence.

Determining the sagittal dimensions of the canal of the cervical spine. The reliability of ratios of anatomical measurements.

The ratio of the sagittal diameter of the cervical canal to the corresponding diameter of the vertebral body has been described as a reliable means for assessing stenosis of the canal and detecting those at risk of cervical neuropraxia. The use of ratio techniques has the advantage of avoiding variation in magnification when direct measurements are made from plain radiographs. We examined the reliability of this method using plain lateral radiographs of unknown magnification and CT scans. We also assessed other possible ratios of anatomical measurements as a guide to the diameter of the canal. Our findings showed a poor correlation between the true diameter of the canal and the ratio of its sagittal diameter to that of the vertebral body. No other more reliable ratio was identified. The variability in anatomical morphology means that the use of ratios from anatomical measurements within the cervical spine is not reliable in determining the true diameter of the cervical canal.