Commentary & Perspective

Commentary & Perspective on
"Free Vascularized Fibular Grafting for the Treatment of Postcollapse Osteonecrosis of the Femoral Head"
by Keith R. Berend, MD, et al.

Commentary & Perspective by
Marvin E. Steinberg, MD, and David R. Steinberg, MD*,
Department of Orthopaedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA

The management of nontraumatic osteonecrosis of the femoral head remains one of the more perplexing challenges faced by the orthopaedic surgeon. Without specific treatment, the femoral head will eventually collapse in approximately 80% of patients with this diagnosis, who will then require arthroplasty. Although a number of surgical approaches have been employed to preserve the femoral head, none is completely satisfactory. Results are worse if surgery is performed after femoral head collapse has occurred.

In the June issue of The Journal, Berend et al. have reported their experience with the use of free vascularized fibular grafting (FVFG) for the treatment of postcollapse osteonecrosis of the femoral head. They retrospectively reviewed the results of this procedure in 224 hips in 188 patients with an average follow-up of 4.3 years. The rate of survival was 64.5% for hips followed for a minimum of five years, and 63% of the patients in whom surgery succeeded had a good or excellent result. Outcome was significantly associated with etiologic factors (p = 0.017). There was a trend toward an association between failure and lesion size and, according to their Kaplan-Meier analysis, the amount of preoperative femoral head collapse was not a significant predictor of outcome. The authors concluded that the results of this procedure were better than those of either nonoperative management or core decompression. They believed that free vascularized fibular grafting improved the clinical status of patients with postcollapse osteonecrosis of the femoral head, delayed the need for total hip arthroplasty in the majority of them, and might eliminate the need for future arthroplasty in many. Other authors have shared these opinions^1,2.

Berend et al. are to be complimented for conducting an excellent study and for providing us with additional clinically relevant information. They have perhaps the most experience of any group with this technique. They have previously cited the physiologic advantages of free vascularized fibular grafting in comparison with other joint-preserving procedures³. They have mentioned, however, that once collapse of the femoral head occurs, it is seldom possible to fully restore the joint.

Most of the hips in this series had moderate to large areas of necrosis but relatively little collapse. Although the overall rate of survival was 64.5% for the hips followed for five or more years, only 63% of the patients in that group had a good or excellent result. Thus, a substantial number of patients either required total hip replacement or had an unsatisfactory result from the grafting procedure.

There are several disadvantages of free vascularized fibular grafting for the treatment of osteonecrosis of the femoral head. This procedure is technically demanding and time-consuming; ideally, two surgical teams that include surgeons experienced in both hip and microvascular surgery should operate simultaneously. Postoperatively, patients remain non-weight bearing initially (for six weeks) and then proceed to progressive weight-bearing for six months. Full weight-bearing is usually resumed at six months. If bilateral surgery is indicated, the second procedure must be postponed for several months, during which time the condition may progress. Free vascularized fibular grafting is associated with a substantial prevalence of complications, which include donor-site morbidity in 24% of patients, subtrochanteric fractures in as many as 2.5%, and systemic complications such as phlebitis and pulmonary embolism^2-5. If the femoral head has already collapsed, it cannot be fully restored, and though this procedure may retard the progression of necrosis, most patients will continue to have symptoms and many will eventually require total hip replacement. Total hip replacement following free vascularized fibular grafting is somewhat more difficult to perform.

The authors compared the results, reported in the literature, of free vascularized fibular grafting with those of core decompression and concluded that their technique was superior. One large series of patients who had core decompressions included ninety-two Stage-IV (postcollapse; University of Pennsylvania classification system) hips with a mean follow-up of four years and a femoral head survival rate of 51%³. Although this survival rate after core decompression was not as good as the 65% survival rate after FVFG that was reported in the present study, there is a question whether this increase in survivorship warrants the performance of a more extensive procedure associated with a higher complication rate. Satisfactory results have also been reported for other joint-sparing procedures, such as rotational osteotomies and various grafting techniques, and a comparison of these results with those of free vascularized fibular grafting has not yet been determined³.

The main rationale for the use of free vascularized fibular grafting and other joint-preserving procedures is that saving the hip in the young patient with osteonecrosis of the femoral head is theoretically better than replacing it. Authors of older studies of total hip replacement in this population reported a high prevalence of early implant failure, but more recent reports indicate a much better rate of survivorship as well as improved results with revision surgery³. If these more recent results of arthroplasty prove to be durable, orthopaedic surgeons will be far less reluctant to perform hip replacement in younger patients with osteonecrosis and partial collapse of the femoral head. Even now, many patients and surgeons would prefer total hip replacement, which has a low complication rate, a 95% rate of good to excellent results, and a 90% chance of ten to fifteen years of joint survival, rather than choose a procedure with a much less certain outcome.

We need well-designed, prospective, controlled studies to compare the safety and effectiveness of this procedure with other joint-preserving techniques. When the femoral head is already collapsed, both the patient and the surgeon must weigh the alternatives carefully in order to decide whether free vascularized fibular grafting or other joint-preserving procedures should be performed, or whether total hip replacement or other arthroplasty should be the index procedure. If free vascularized fibular grafting is chosen, ideally it should be performed in selected centers that have personnel with the requisite expertise, the surgeon-procedure volume, and the hospital-procedure volume to yield optimum results in this population 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. Sotereanos DG, Plakseychuk AY, Rubash HE. Free vascularized fibular grafting for the treatment of osteonecrosis of the femoral head. Clin Orthop. 1997;344:243-56.
2. Soucacos PN, Beris AE, Malizos K, Koropilias A, Zalavras H, Dailiana Z. Treatment of avascular necrosis of the femoral head with vascularized fibular transplant. Clin Orthop. 2001;386:120-30.
3. Steinberg ME, Mont MA. Osteonecrosis. In: Chapman MW, Szabo RM, Marder R, Vince KG, Mann RA, Lane JM, McLain RF, Rab G, editors. Chapman's orthopaedic surgery. 3rd Edition. Philadelphia: Lippincott Williams and Wilkins; 2001. pp 3263-308.
4. Aluisio FV, Urbaniak JR. Proximal femur fractures after free vascularized fibular grafting to the hip. Clin Orthop. 1998;356:192-201.
5. Vail TP, Urbaniak JR. Donor-site morbidity with use of vascularized autogenous fibular grafts. J Bone Joint Surg Am. 1996;78:204-11.