Soft Tissue Reconstruction Using a Distally Pedicled Biceps Femoris Flap in Refractory Fracture-Related Infection around the Knee: An Orthoplastic Approach

Michael R. Bauer1, Dirk J. Schaefer1, Mario Morgenstern2, Rik Osinga2, Florian Frank2, Martin Clauss2

1 - Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital Basel, Switzerland

2 - Department of Orthopaedics and Traumatology, University Hospital Basel, Switzerland

INTRODUCTION AND AIM

Fracture-related infections (FRI) with extensive soft tissue defects around the knee represent a major challenge

in extremity reconstruction. Successful treatment requires an orthoplastic approach integrating radical

debridement, stable fixation, infection control, and robust soft tissue coverage. In cases with multiple prior

reconstruction failures, limb salvage becomes increasingly difficult. This report aims to highlight the role of a

regional muscle flap — the distally pedicled biceps femoris flap — as a last-resort option for knee preservation.

 

METHODS

A patient with a distal femoral fracture (AO 32-C3, Gustilo-

Anderson type II) initially treated with an intramedullary

nail and lateral plate developed FRI with a fistulating soft

tissue defect over the lateral distal thigh. Following implant

removal, radical debridement, and re-osteosynthesis with

a retrograde femoral nail, multiple reconstructive

procedures were performed. Soft tissue reconstruction

attempts included a lateral gastrocnemius flap, a split

vastus lateralis muscle flap, a distally pedicled gracilis flap

and a free anterolateral thigh (ALT) flap, all of which failed

to provide sufficient and durable coverage. As a final

salvage procedure, a distally pedicled biceps femoris

muscle flap was performed. The long head of the biceps

femoris was harvested and transected at its origin on the

pubic bone, while the short head was preserved to

minimize impairment of knee stability and function.

Residual viable tissue from the initial gastrocnemius flap

was preserved. Finally the biceps femoris muscle flap and

the partially exposed vastus lateralis were covered

with split-thickness skin grafts.

RESULTS

The distally pedicled biceps femoris flap achieved stable

soft tissue reconstruction with satisfactory integration and

resolution of infection. Dead space was effectively

obliterated, and durable coverage of the distal femur was

obtained. The knee joint was preserved without clinically

relevant impairment of knee function or stability, thereby

avoiding knee arthrodesis or above-knee amputation.

 

CONCLUSION

The distally pedicled biceps femoris muscle flap is a rarely used but valuable salvage option for complex soft

tissue defects around the lateral distal femur and knee. Even after failure of standard local and free flap

procedures, it can represent a reliable last-resort option for limb salvage. The biceps femoris flap can be

particularly useful for defects beyond the reach of the gastrocnemius flap in the lateral regions of the knee and

distal thigh when conventional local options have failed and further free flap reconstruction is not feasible.