Free Vascularized Medial Femoral Condyle Structural Flaps for Septic Terminal Digital Bone Loss

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.

The Medial Femoral Condyle Flap in the Pediatric Patient

BACKGROUND

The use of free flaps from the medial femoral condyle has grown in popularity and is now a workhorse in the reconstruction of skeletal defects. The utility of this technique has not yet been described for the pediatric patient population. The authors present their series of pediatric patients who underwent surgery using a medial femoral condyle free flap or a variant thereof in skeletal reconstruction and demonstrate the efficacy of this technique in this population.

METHODS

A multi-institutional retrospective review of patients aged 18 years or younger who required a medial femoral condyle flap for skeletal reconstruction was undertaken. Operative technique, radiographs, and clinical outcomes were recorded. A novel technique (Innocenti) was used to avoid the distal femoral physis in which a Kirschner wire was placed under fluoroscopic guidance just proximal to the growth plate.

RESULTS

Thirteen patients met inclusion criteria, with an average age of 14.7 years (range, 7 to 18 years) and mean follow-up of 28 months (range, 3 to 120 months). Six were skeletally immature at the time of medial femoral condyle harvest, with the last patient having organic bone disease, putting her at risk for pathologic fracture. All 13 patients achieved bony union, and no patients suffered pathologic fractures or physeal injuries; no patients developed length discrepancies.

CONCLUSIONS

The authors present the first series of corticocancellous medial femoral condyle free flaps in the pediatric population along with a novel technique to avoid injury to the physis in skeletally immature patients. This technique is effective for a variety of skeletal defects or nonunions and is safe for growing patients without causing physeal arrest or growth disturbance.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Compound or Specially Designed Flaps in the Lower Extremities

Novel and combined tissue transfers from the lower extremity provide new tools to combat soft tissue defects of the hand, foot, and ankle, or fracture nonunion. Flaps can be designed for special purposes, such as providing a gliding bed for a grafted or repaired tendon or for thumb or finger reconstruction. Propeller flaps can cover soft tissue defects of the leg and foot. In repairing severe bone and soft tissue defects of the lower extremity, combined approaches, including external fixators, one-stage vascularized bone grafting, and skin or muscle flap coverage of the traumatized leg and foot, have become popular.

Donor-Site Morbidity of Vascularized Bone Flaps from the Distal Femur: A Systematic Review

BACKGROUND

Vascularized grafts from the femur, including the medial femoral condyle and medial femoral trochlea, are increasingly being used. It is critical to understand the lower extremity complications from flap harvest.

METHODS

The authors searched available literature reporting on femoral flaps using PubMed, Embase, Cochrane Database, and Web of Science. After article selection, data were collected regarding demographics, procedure details, outcomes, and complications. The authors classified outcomes as good, fair, or poor based on pain, range-of-motion, sensory changes, subjective reporting, patient-reported outcomes, and other donor-site complications, including the need for additional procedures.

RESULTS

Two hundred twenty articles were identified. Forty-five met criteria for review, with data available for 283 patients. No patients had range-of-motion deficits beyond 1 year. Two percent of patients (six of 283) required additional donor-site procedures, with one report of a femur fracture after medial femoral condyle harvest. Only one study on 45 medial femoral trochlea patients presented patient-reported outcomes regarding the knee. Few objective data were presented. Twenty-eight articles presented adequate complication data for 252 patients to be rated as good, fair, or poor. Overall, 89 percent had good outcomes without donor-site complications. Of the 176 medial femoral condyle patients with outcomes reported, 92 percent had good outcomes; and 71 percent of the 48 medial femoral trochlea patients had good outcomes reported.

CONCLUSIONS

Overall, the reported donor-site morbidity from medial femoral condyle and medial femoral trochlea harvest is low. Chronic knee pain and sensory changes are most frequently reported, especially in medial femoral trochlea patients.

Wrist arthrodesis with the medial femoral condyle flap: Outcomes of vascularized bone grafting for osteomyelitis

BACKGROUND

Osteomyelitis of the wrist is rare but destructive. Subsequent bone defects often require vascularized bone for successful healing. Recent literature has pointed to the successful use of the medial femoral condylar (MFC) flap for difficult non-unions, yet it has not been specifically described for wrist fusion. We present our experience with this technique for limited and complete wrist arthrodesis.

PATIENTS AND METHODS

We reviewed 4 cases of radiocarpal bone loss from osteomyelitis. All cases utilized debridement of nonviable tissues, and at least 6 weeks of intravenous antibiotics, followed by vascularized bone grafting with a MFC flap. The flap was based on the horizontal periosteal branch of the descending geniculate artery, and utilized to directly bridge the bony defects following resection.

RESULTS

Three patients healed primarily, and 1 patient required secondary cancellous bone grafting to reach union. One patient required revision of the donor site closure. None of the patients had a recurrence of infection or other complications. Average follow up was 8.5 months after reconstruction. Average time to union was 11.5 weeks. Three patients demonstrated full composite fist, and 1 patient had incomplete finger range of motion following several flexor and extensor tendon grafts.

CONCLUSIONS

These cases illustrate the use of the MFC in wrist arthrodesis after osteomyelitis defects. In all cases, there was complete union in a short time, no recurrence of infection, and low donor-site morbidity.

Compound or Specially Designed Flaps in the Lower Extremities

Novel and combined tissue transfers from the lower extremity provide new tools to combat soft tissue defects of the hand, foot, and ankle, or fracture nonunion. Flaps can be designed for special purposes, such as providing a gliding bed for a grafted or repaired tendon or for thumb or finger reconstruction. Propeller flaps can cover soft tissue defects of the leg and foot. In repairing severe bone and soft tissue defects of the lower extremity, combined approaches, including external fixators, one-stage vascularized bone grafting, and skin or muscle flap coverage of the traumatized leg and foot, have become popular.