Medial Femoral Condyle Free Flap Reconstruction of Complex Foot and Ankle Pathology

Medial Femoral Condyle Free Flap: A Systematic Review and Proportional Meta-analysis of Applications and Surgical Outcomes

Background

Recalcitrant bone nonunion and osseous defect treatment is challenging and often requires vascularized bone transfer. The medial femoral condyle flap has become an increasingly popular option for reconstruction. The study aims at reviewing its different applications and synthesizing its surgical outcomes.

Method

A systematic review including all studies assessing surgical outcomes of free medial femoral condyle flap for bone reconstruction in adults was conducted on January 31, 2023. Flap failure and postoperative complications were synthesized with a proportional meta-analysis.

Results

Forty articles describing bony reconstruction in the head and neck, upper limb, and lower limb areas were selected. Indications ranged from bony nonunion and bone defects to avascular bone necrosis. Multiple flaps were raised as either pure periosteal, cortico-periosteal, cortico-cancellous-periosteal, or cortico-chondro-periosteal. A minority of composite flaps were reported. Overall failure rate was 1% [95% confidence interval (CI), 0.00-0.08] in head & neck applications, 4% in the lower limb (95% CI, 0.00-0.16), 2% in the upper limb (95% CI, 0.00-0.06), and 1% in articles analyzing various locations simultaneously (95% CI, 0.00-0.04). Overall donor site complication rate was 4% (95% CI, 0.01-0.06). Major reported complications were: femoral fractures (n = 3), superficial femoral artery injury (n = 1), medial collateral ligament injury (n = 1), and septic shock due to pace-maker colonization (n = 1).

Conclusion

The medial femoral condyle flap is a versatile option for bone reconstruction with high success rates and low donor site morbidity.

Medial Femoral Condyle Free Flap for Persistent Osseous Nonunion of the First Metatarsophalangeal Joint: A Preliminary Report of a New Surgical Indication for the Medial Femoral Condyle Free Flap

Background

Recalcitrant or persistent nonunions of the metatarsophalangeal (MTP) joint occur following failed MTP surgery for MTP fusion, failed MTP prosthesis, for hallux rigidus or due to infection and erosion. A deficient soft tissue envelope and compromised vascular supply of tissues in this region compound further attempts to salvage the great toe and preserve function. The medial femoral condyle (MFC) free flap provides vascularized corticocancellous bone and periosteum and has been successfully used for a variety of complex hindfoot and ankle pathologies. We present an additional indication with a small cohort study demonstrating its use in persistent nonunions of the first MTP joint.

Methods

A retrospective review was completed of all MFC flaps used for revision of failed first MTP joint fusion from January 2019 to November 2022. Demographic information, comorbidities, as well as clinical and radiologic follow-up was obtained from the patient charts.

Results

Three patients were included with MTP nonunion and an average of 7.5 (range, 5-11) failed prior surgeries. Mean age at index surgery was 50 (range, 46-57) years. An osseous union was achieved in all patients after 82 (range, 75-88) days. Hardware removal was possible after 81 (range, 55-98) days. Mean follow-up was 17 (range, 5-31) months. We note a 100% flap success rate without returns to the operating room. The lengths of the bone flaps were 2 to 4 cm, the volumes were 8 to 12 cm3. Fixation was performed with 1 intramedullary K-wire. The recipient vessel in all patients was the dorsalis pedis artery or a tributary thereof. All arterial anastomoses were performed under the operating microscope.

Conclusion

The MFC free flap is a reasonable option for salvage of complex recalcitrant or persistent nonunions of the first MTP joint. More prospective long-term studies with functional outcomes are necessary to confirm these findings.

Level of Evidence

Level IV, retrospective case series.

Soft-Tissue Reconstruction of Complicated Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty (TAA) is a popular modality to treat end-stage arthritis or internal ankle derangement. Unfortunately, failure rates remain undesirably high, with severe complications, including prosthesis failure, ankle fusion, and amputation. The importance of a stable soft-tissue envelope for coverage of implant compromise has been previously described, but the predictive factors for successful salvage of complicated TAA remain poorly understood.

METHODS

A retrospective review was conducted of patients requiring soft-tissue reconstruction following TAA wound complications. Patient demographics, history, microbiological data, reconstructive approach, and outcomes data were collected. Statistical analysis was used to abstract factors associated with unsuccessful prosthetic salvage.

RESULTS

In all, 13 patients met inclusion criteria: 8 (61.5%) achieved prosthetic salvage, and 5 (38.5%) failed. The majority (90.9%) of patients presented with infected joints. Reconstructive techniques included skin grafts, dermal substitutes, locoregional flaps, and free tissue transfer. Successful prosthetic salvage was associated with shorter time intervals between wound diagnosis and index reconstructive surgical intervention (median: 20 days for salvage vs 804 days for failure; P = .014). Additionally, salvage was associated with reduced time from the index orthopaedic/podiatric surgical intervention to the index reconstructive surgery procedure (12 vs 727 days; P = .027).

CONCLUSION

The prognosis of complicated TAA requiring soft-tissue reconstruction remains poor, especially in patients who present with infected joints. Several reconstructive techniques, ranging from simple skin grafts to complex free tissue transfers, can be used successfully. Early intervention to achieve soft-tissue coverage is crucial in maximizing salvage rates in the setting of complicated and infected TAA.

LEVEL OF EVIDENCE

Level IV.

Reconstruction Options for Lower Extremity Traumatic Wounds

The senior author first coined the "orthoplastic" approach to traumatic lower extremity reconstruction, by which multidisciplinary surgeons and specialists work together for optimal patient success. The goals of lower extremity salvage are to optimize limb appearance, restore unrestricted pain-free ambulation, and improve quality of life. Composite traumatic defects require an organized approach, and the reconstructive ladder is used for strategies of varying complexity for repair of soft-tissue wounds. The lower rungs of the ladder include simpler reconstructive options such as the use of skin grafts and local flaps, and the higher rungs represent complex techniques such as free tissue transfer. Although there is no notable difference between muscle and fasciocutaneous/perforator flaps in reconstructive outcomes, there has been a trend toward perforator flaps to minimize donor site morbidity.

Biologic Augmentation of Tibiotalocalcaneal Arthrodesis With Allogeneic Bone Block Is Associated With High Rates of Fusion

BACKGROUND

The orthopaedic conditions and systemic comorbidities that occur in patients who require bone block tibiotalocalcaneal (TTC) arthrodesis have made this procedure associated with a higher-than-normal risk of nonunion, graft collapse, hardware failure, and amputation. Here, we present a novel approach to bone block TTC arthrodesis using adjunctive osteoinductive agents and a prolonged course of protected weightbearing to assess if we could improve on historical outcomes. We also evaluated the efficacy of a vascularized medial femoral condyle (MFC) free flap to augment TTC arthrodesis.

METHODS

Fourteen adult patients underwent bone block TTC arthrodesis biologically augmented with fresh-frozen femoral head allograft, bone marrow aspirate concentrate, and demineralized bone matrix cortical fibers. Three patients with soft tissue defects underwent vascularized reconstruction with an MFC free flap. Radiographic union, the Foot Function Index (FFI), and PROMIS pain interference (PI), and physical function (PF) scores were assessed at follow-up.

RESULTS

TTC fusion was documented on plain radiograph in 13 of 14 patients (92.9%) and CT in 10 of 11 patients (90.9%). Mean time to fusion was 183.2 ± 83.2 days. One patient (7.1%) experienced nonunion and persistent infection requiring amputation. Patients who underwent vascularized bone grafting had significantly shorter time to fusion (112.3 ± 31.7 days vs 204.4 ± 82.7 days, P = .05). Patient-reported outcomes revealed mild to moderate pain and dysfunction after 1 year (mean FFI = 41.0% ± 23.1%, PROMIS PI = 58.3 ± 1.8, PROMIS PF = 39.0 ± 2.2).

CONCLUSION

In this relatively small series, the biologic augmentation of bone block TTC arthrodesis with osteoinductive agents and protective weightbearing resulted in excellent rates of fusion, modest pain, and preserved function of the lower extremity in almost all those treated. Osseous healing appears to be enhanced and accelerated with application of an MFC flap. We believe that this approach offers a viable salvage option for these challenging clinical problems.

LEVEL OF EVIDENCE

Level IV, case series.