Commentary & Perspective

Commentary & Perspective on
"Vascularized Compared with Nonvascularized Fibular Grafting for the Treatment of Osteonecrosis of the Femoral Head"
by Anton Y. Plakseychuk, MD, PhD, et al.

Commentary & Perspective by
Michael A. Mont, MD, and Gracia Etienne, MD, PhD*,
Center for Joint Preservation and Replacement, Rubin Institute for Advanced Orthopaedics, Sinai Hospital of Baltimore, Baltimore, MD

The article by Plakseychuk et al. provides important information regarding treatment options for osteonecrosis of the femoral head. The authors compared clinical results in two groups of patients with osteonecrosis: one group was treated with nonvascularized fibular grafting in Korea and the other group was treated with free vascularized fibular grafting in the United States. At a follow-up of approximately five years, the Harris hip scores improved for 70% of the hips treated with free vascularized fibular grafting in comparison with such an improvement for only 36% of the hips treated with nonvascularized fibular grafting. The authors concluded that vascularized fibular grafting was associated with better clinical and radiographic results than was nonvascularized fibular grafting for osteonecrosis of the femoral head.

We commend the authors for performing a study that is superior to most published studies comparing methods of treatment of this disease. The two groups of fifty hips were matched very carefully for stage, size, and etiology of the lesion as well as for the mean preoperative Harris hip score and the duration of follow-up (a mean of five years). However, despite this attempt to match parameters that are considered important variables, the reader should be cautioned that the results were generated at two different medical centers with different surgeons and separate patient populations. We believe, therefore, that appreciation of the conclusions of this study must be tempered by awareness of some of the following limitations.

This is a retrospective study comparing fifty hips selected from a group of 200 patients (220 hips) treated with free vascularized fibular grafting at the University of Pittsburgh from 1989 to 1999 with fifty hips in ninety-nine patients (123 hips) who were treated with nonvascularized fibular grafting at the Kyungpook National University Hospital in South Korea during a different period of time (1986 to 1996). Apparently the surgeons at each center were unaware that those at the other were performing these types of procedures at the time.

Although the authors have done a credible job of presenting the two procedures as similar except for one factor (use of vascularized graft versus nonvascularized graft), there are still technical differences between the two procedures, and there is no indication that the surgeons at the two centers contacted each other during the time that they were performing these procedures to make sure that the two techniques were otherwise uniform.

A major problem with this comparison by Plakseychuk et al. is that the prognosis and the outcome of surgical treatment for osteonecrosis of the femoral head differ greatly between the patients in these two populations. Good results have been reported for the transtrochanteric osteotomy as described by Sugioka in Asian patients¹, including those from Korea², but [this procedure has had poor results in patients from the United States³. When Sugioka performed this procedure in patients at multiple centers in the United States, the failure rate was greater than 80%.

Plakseychuk et al. have made a commendable effort to determine the better treatment method. While they found that the patients treated with vascularized fibular grafting had much better clinical scores than did those treated with the nonvascularized fibular grafting, they also found much more morbidity in the vascularized graft group (a 22% prevalence of deep venous thrombosis, peroneal palsy leading to clawing of the great toe, and peroneal neuropathy) in comparison with a 4% prevalence of sensory peroneal neuropathy in the nonvascularized graft group.

The ideal study comparing the clinical results of these two types of grafts would be a prospective study in which the same surgeon or surgeons educated in the same techniques treat two similar groups of patients—one group with the vascularized graft and the other with the nonvascularized graft. In addition, there are easier methods of nonvascularized bone grafting that do not involve sacrificing a portion of the fibula^4,5. Nevertheless, since such a prospective study has been found to be very difficult to perform, we believe that this is an excellent study comparing the results of these two treatments.

Vascularized fibular grafts had superior results in Stage-I and Stage-II hips. It is certainly possible that other methods (core decompression with or without bone-grafting or the use of other ancillary growth factors⁶, osteotomy, or other procedures⁷) might provide equally effective treatment of these hips. One should note that of the Stage-III hips in this study, all fifteen hips that received the nonvascularized fibular graft were rated poor according to the Harris hip score; however, eleven (73%) of the fifteen hips that were treated with vascularized fibular grafting also had a poor rating. In our opinion, this 73% failure rate does not justify the use of vascularized fibular grafting in Stage-III hips. These patients may have had better results after treatment with arthroplasty. Although this study is commendable, the results underscore the need for further research that can be used to develop procedures that offer more predictable outcomes, particularly in hips with more advanced osteonecrosis, and thus obviate the need for total hip arthroplasty in this young (mean age, forty-four years) group of patients.

*The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.

References

1. Sugioka Y, Hotokebuchi T, Tsutsui H. Transtrochanteric anterior rotational osteotomy for idiopathic and steroid-induced necrosis of the femoral head. Indications and long-term results. Clin Orthop. 1992;277:111-20.
2. Yoo MC, Chung DW, Hahn CS. Free vascularized fibula grafting for the treatment of osteonecrosis of the femoral head. Clin Orthop. 1992;277:128-38.
3. Dean MT, Cabanela ME. Transtrochanteric anterior rotational osteotomy for avascular necrosis of the femoral head. Long-term results. J Bone Joint Surg Br. 1993;75:597-601.
4. Rosenwasser MP, Garino JP, Kiernan HA, Michelsen CB. Long term followup of thorough debridement and cancellous bone grafting of the femoral head for avascular necrosis. Clin Orthop. 1994;306:17-27.
5. Mont MA, Einhorn TA, Sponseller PD, Hungerford DS. The trapdoor procedure using autogenous cortical and cancellous bone grafts for osteonecrosis of the femoral head. J Bone Joint Surg Br. 1998;80:56-62.
6. Mont MA, Jones LC, Einhorn TA, Hungerford DS, Reddi AH. Osteonecrosis of the femoral head. Potential treatment with growth and differentiation factors. Clin Orthop. 1998;355 Suppl:S314-35.
7. Mont MA, Hungerford DS. Non-traumatic avascular necrosis of the femoral head. J Bone Joint Surg Am. 1995;77:459-74.