A quantitative system for staging avascular necrosis.

Much of the current confusion and contradiction on the treatment of avascular necrosis of the femoral head is caused by the lack of an agreed efficient, quantitative system for evaluation and staging. We have used a new system to evaluate over 1000 hips with avascular necrosis during a period of 12 years; it has proved to be very valuable. The system is based on the sequence of pathological events known to take place. It allows accurate quantification in both early and later stages, does not use older, invasive diagnostic procedures, and incorporates the newer techniques of bone scanning and MRI. Clinical records of pain and reduced function are not a specific part of the system, although they help to determine treatment and outcome. Hips are first placed into one of seven stages from 0 to VI, based upon the type of radiological change. The extent of involvement is then measured. This allows more accurate evaluation of progression or resolution and better comparison of different methods of management. The system also helps to provide a prognosis and to decide on the best available method of treatment.

Osteonecrosis of the femoral head. Results of core decompression and grafting with and without electrical stimulation.

The effectiveness of core decompression and bone grafting with and without electrical stimulation was investigated in patients with avascular necrosis (AVN) of the femoral head. One hundred sixteen hips with AVN had decompression and grafting; 74 were also treated with direct current (DC). The DC stimulation was via a coil inserted directly into the femoral head. These were compared to 55 hips with AVN treated nonoperatively. Hips treated with electrical stimulation showed less roentgenographic progression and achieved a better clinical score than hips treated with decompression and grafting alone. Both groups had a significantly lower incidence of arthroplasty than the nonoperated controls. One patient developed a pulmonary embolus, but there were no fractures or other complications. Decompression and grafting are safe and reasonably effective in retarding the progression of AVN. Supplemental electrical stimulation seems to improve the results even further.

Electrical stimulation in the treatment of osteonecrosis of the femoral head--a 1-year follow-up.

To date, there is no completely satisfactory method for the treatment of osteonecrosis of the femoral head. "Conservative" management leads to a high failure rate, and surgical results have been inconsistent and disappointing. The study described in this article seeks to evaluate the role of electrical stimulation in conjunction with decompression and bone grafting. A total of 82 hips have been included to date, of which 42 with a minimum follow-up of 1 year have been evaluated. Pain relief and improved function have been noted in the majority of hips operated on, both with and without electrical stimulation. Careful radiologic assessment using a comprehensive new method of evaluation has shown some degree of progression in the majority of cases, however. No effects of electrical stimulation per se have been demonstrated to date. It must be emphasized that this is a preliminary report with a minimum follow-up of 1 year. Final conclusions await the completion of the study, when all patients have been followed for a minimum of 3 years.

Treatment of avascular necrosis of the femoral head by a combination of bone grafting, decompression, and electrical stimulation.

The goal in the treatment of avascular necrosis is to preserve, not replace, the femoral head. Although many methods have been proposed, none has proved completely satisfactory. Electrical stimulation as a supplement to bone grafting and decompression is an attractive approach to this problem because it combines the desirable features of other procedures, each of which has shown a certain degree of effectiveness in stimulating bone growth and repair. Preliminary results indicate that patients treated with decompression and grafting alone and those in whom electrical stimulation was added to these had better results than patients treated by "conservative" means. The effectiveness of the electrical stimulation itself, however, has not yet been established and remains an important area for investigation. Further improvements in delivery systems and techniques are required to develop better methods for the treatment of avascular necrosis.

Early results in the treatment of avascular necrosis of the femoral head with electrical stimulation.

Our goal in the treatment of avascular necrosis is to retard or reverse the progressive changes that normally take place and thus preserve rather than replace the femoral head. "Conservative" or nonoperative management has generally proved unsuccessful, and results with established surgical procedures have been inconsistent and frequently disappointing. A new approach has been described that uses direct-current stimulation in conjunction with bone grafting and decompression. Results were determined clinically and radiographically using a new method of staging and evaluation. The majority of patients who underwent surgery showed significant clinical improvement, especially in regard to pain relief. Some degree of radiologic progression, however, was detected in most cases, even in many with clinical improvement. Electrical stimulation, as used in this study, did not appear to alter the results obtained with decompression and grafting alone. It must be emphasized that this is a preliminary report. More data and longer follow-up will be required before definitive conclusions can be drawn, and we must continue our efforts to improve the management of avascular necrosis.