Key points

Introduction

Various trauma or tumor surgery on lower limbs can result in not only soft tissue envelope defects but also variable functional deficits. Numerous resurfacing procedures are available to repair the defects. Improvements in sterile technique, the use of antibiotics, bony fixation, and microvascular reconstruction have shifted the management paradigm of mutilating limb and limb salvage to functional restoration. The ultimate goal of reconstructing a lower extremity is to achieve painless, stable weight-bearing walking, which requires adequate bone union, a pliable stable joint, and a sensate sole.

In the scenario of open wounds, all the vital structural defects can be well recognized and assessed, and the required recipient neurovasculature is exposed entirely. It is best to plan either a 1-stage or staged reconstructive strategy. Severely contaminated or mutilated limbs make the viability of the traumatized tissue questionable, so the lesion may require repeated debridement before the coverage reconstruction. If the wound infection or contamination is under control, functional reconstruction can be combined with the resurfacing procedure to provide a simultaneous soft tissue and functional restoration.

The authors believe that functional reconstruction should incorporate conventional or microsurgical methods for the restoration of functional loss. Methods such as vascularized bone transfer, bone grafting or distraction, tendon transfer, free functioning muscle transfer, and sensate glabrous skin for plantar defect resurfacing are all designed for functional considerations.

The restoration of a stable, strong femur or tibial bony structure is essential for weight bearing. Conventional bone graft or bone substitute can be used for small-segment bony defects.

Improvements in microsurgical free tissue outcomes contribute to the functional result and quality of life. Establishment of comprehensive wound repair, bony union, and motor unit transplant is the standard for adequate lower extremity functional restoration.

Despite the psychological advantages of limb salvage, the return to premorbid status is equivalent to limb amputation. Thus the reconstructive procedures should be designed to accomplish comprehensive coverage and functional management to shorten the disability and return to work times.

Indications and contraindications of preferred reconstructions, including rationale and timing

The Lower Extremity Assessment Project (LEAP), the first and only prospective, multi-institutional cohort study of several scoring systems on severe lower extremity trauma, found no association between loss of plantar sensation and the need for late amputation, dispelling one of the classic absolute indications for amputation. A comparison of functional outcomes between the amputated and salvaged cohorts found no significant differences.

The scores are not definitely compatible with the functional outcomes. Even low scores tend to have higher lower limb salvage rate. Many patients with high scores have successful salvage or functional outcomes. Recontracture surgery is not appropriate for reconstructable limbs. ^, Thus, reconstructable limbs are related to the facility of the hospital or collaborative team. Appropriate referral of the traumatized patients to a competent team at the right time is essential.

However, before the definite reconstruction, all patient should have justified damaged control for the polytrauma insult. Particularly in patients presenting with impending lethal triad, the overwhelming pathophysiologic effect of severe inflammatory response syndrome or complementary antiinflammatory response syndrome can be life threatening.

In recent decades, free tissue transfers, local flaps, or pedicle perforator flaps have been widely used for posttraumatic lower limb defect reconstruction. Resurfacing surgeries aim at wound repair, either skin, muscle, or osteocutaneous flaps. To go a step further, functional restoration can enhance the benefit for functional deficits of lower limbs. Simultaneous or secondary tendon transfer, or arthrodesis, is applied for functional purposes. Composite free tissue can comprise different components to improve the functional unit loss in various reconstructions.