Medial Femoral Condyle Periosteal Free Flap: A Novel Technique for the Treatment of Avascular Necrosis of the Talus

CATEGORY: Hindfoot INTRODUCTION/PURPOSE: Avascular necrosis (AVN) of the talus is commonly caused by trauma and often requires surgical management. It is recommended that healthy patients, in pre-collapse stages, undergo joint preservation procedures. Good results have been published in patients in pre-collapse stages who undergo vascularized bone grafting. Although many graft options exist, more recently the medial femoral condyle (MFC) free vascularized graft has been introduced. This graft typically utilizes vascularized corticoperiosteal bone but can be modified to the use of solely periosteum, which theoretically decreases morbidity and operative time. There is limited research on the periosteal-only MFC flap to treat AVN of the talus. We present a case series and surgical technique utilizing a periosteal vascularized pedicle graft to teat AVN of the talus. METHODS: A surgical technique is presented, in addition to a retrospective review of AVN of the talus of 6 lower extremities. Treatment included talus core decompression along with an ipsilateral medial femoral condyle free vascularized periosteal graft. All patients included were in the pre-collapse stage. Short-term clinical outcome measures of Foot & Ankle Ability Measure- Activities of Daily Living (FAAM-ADL) subscale, Short Form-12 (SF-12), and Visual Analog Scale (VAS) for pain were recorded for all patients post-operatively. Paired T-tests were used to compare pre- and post-operative functional scores. Post-operative MRIs were reviewed by a musculoskeletal radiologist. RESULTS: The causes of AVN included trauma (2/6, 33%), sepsis (2/6, 33%), and idiopathic (2/6, 33%). Post-operative FAAM-ADL (P=0.004) and VAS (P=0.003) scores showed statistically significant improvement from pre-operative values at an average of 16.0 months (range, 6-28 months) after surgery. Additionally, all patients (100%) reported being “very satisfied” with their surgical outcome. There was 1 minor complication, with one patient reporting minimal paresthesias following surgery. Post-operative MRIs, taken at a mean of 12.7 months, demonstrated both resolution of marrow edema and soft tissue inflammation surrounding the areas of AVN and a lack of AVN progression in 100% of lower extremities, when compared to pre-operative MRIs. CONCLUSION: Medial femoral condyle free vascularized periosteal graft is a complex procedure which requires a team comprised of a foot & ankle surgeon and a plastic/hand surgeon familiar with microvascular surgery. This study shows promising initial results for the treatment of an extremely challenging diagnosis: AVN of the talus. Long-term, prospective studies are needed to confirm the findings presented in the current study.