Free Vascularized Fibular Grafting for Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) remains a challenging condition in orthopaedics¹. Free vascularized fibular grafting (FVFG) theoretically has the potential to restore blood supply to the femoral head and enhance mechanical stability within the femoral head. This method has shown promising clinical outcomes in hip preservation. Previous studies have utilized the anterolateral approach to the hip for this surgical procedure. Here, we report a minimally invasive technique utilizing the direct anterior approach for debridement and bone grafting, requiring a shorter fibular graft and simplifying the procedure. This method holds potential as an effective treatment option for early to mid-stage femoral head necrosis².

This technique integrates the procurement of the fibula and its implantation into the femoral head via a direct anterior approach. The fibular pedicle is harvested, along with its nutrient peroneal vessels. The lateral circumflex femoral vessels are then exposed. Subsequently, an anterior capsulotomy and a cortical trough are created along the femoral neck. The necrotic region is extirpated and substituted with the fibular pedicle and cancellous bone from the femoral neck. Finally, an anastomosis is formed between the peroneal vessels of the transplanted fibula and the ascending branches of the lateral circumflex femoral vessels³.

Nonoperative alternatives for the treatment of ONFH include lifestyle changes like weight control, restriction of weight-bearing activities, and alcohol cessation, alongside pharmaceutical interventions that include antilipemic agents, anticoagulants, vasodilators, and bisphosphonates. Physical therapy methods such as electromagnetic stimulation, extracorporeal shock-wave therapy, and hyperbaric oxygen may also be employed. The surgical approaches to this condition cover a wide array of operations, including core decompression, precursor cell implantation, nonstructural bone grafting, nonvascularized bone grafting, vascularized iliac bone flap transfer, transtrochanteric rotational osteotomy, and porous metal implantation⁴.

FVFG theoretically not only provides potential mechanical support for the necrotic femoral head, which may help prevent collapse, but also has the potential to improve the internal circulation of the femoral head and thus provide a favorable environment for osteoblast activity and contribute to bone induction and formation⁵. It is hypothesized that FVFG targets the pathological mechanism of femoral head necrosis to potentially impede disease progression. For patients <50 years old, FVFG is suitable for treating Association Research Circulation Osseous (ARCO) stage-II ONFH before collapse. For patients <30 years old, FVFG can be utilized to protect the femoral head, even if it has collapsed as ARCO stage III⁶. In light of the need to obtain the vascularized fibular graft, potential complications may include abnormal skin sensation in the lower leg, leg weakness, and ankle pain or weakness³.

On the basis of existing research⁴, FVFG is regarded as a therapeutic option for ONFH. Some reports have provided evidence that FVFG is more effective than nonoperative treatment or core decompression without grafting-although a direct comparison with core decompression augmented with cellular therapies in a prospective trial is lacking^5,7-9. FVFG also carries the benefit of improving blood supply to the femoral head⁵. In our prior investigation published in 2013³, we presented the comprehensive outcomes of FVFG as a treatment strategy for ONFH. The follow-up ranged from 3 to 10 years, with an average of 5.0 years. Only 4.0% of patients (20 of 407) subsequently underwent total hip arthroplasty (THA). On average, patient Harris hip scores increased from 65.0 to 86.9. In another study of 854 patients (1,206 hips) published in 2024¹⁰, 275 hips (22.8%) had hip failure at a median follow-up of 110.3 months (interquartile range [IQR], 29.3 to 137.8 months; range, 3 to 214 months). Of these, 143 hips underwent THA and an additional 132 hips were considered to require a future THA. The median time to hip failure was 68.2 months (IQR, 14.9 to 120.4 months) after FVFG. Kaplan-Meier survival analysis showed that, overall, the estimated survival time was 165.5 months, estimated cumulative survival rate was 79.2% (95% confidence interval [CI], 77.1% to 81.3%), and estimated annual hazard rate was 1.9% (95% CI, 1.7% to 2.1%). Among 1,161 hips with complete records, mean Harris hip scores improved from 70.1 ± 16.4 points before FVFG to 80.9 ± 14.0 points at the time of the latest follow-up (p < 0.001). When compared with other surgical techniques, FVFG exhibits distinct benefits because of its periosteal blood supply and strong structural support, although comparisons with cellular therapies have not been performed⁸.

To safeguard the arcuate artery, it is advisable to sever the fibula with a muscle cuff measuring approximately 1 to 2 cm in length.The length of the fibula should be adjusted according to the surgical method utilized for the hip. Retain the fibula along with the peroneal arteriovenous vessels on the corresponding side, ensuring the preservation of the peroneal vessels to the greatest extent possible.To maintain ankle joint stability, it is necessary for the distal end of the fibula to be positioned at a minimum distance of 8 cm from the ankle joint following its removal.Prior to preparing the free fibula, it is important to carefully examine the side walls of the main vessels for any notable leakage. If leakage is detected, prompt repair should be performed.The period of weight-bearing should be established on the basis of postoperative radiographic follow-up in order to prevent weight-bearing too early, which can result in femoral head collapse and failure of the head preservation therapy.

CD = core decompressionCT = computed tomographyARCO = Association Research Circulation OsseousMRI = magnetic resonance imaging.