1.1 Introduction

Lower extremity reconstruction, whether needed for a sequela of severe trauma, cancer ablation, diabetes and/or vascular disease, or chronic infections, remains the most challenging of all reconstructions of the human body. The involvement of multiple discrete structures including bone, muscle, tendon, vessel, and nerve, all contained within the skin itself, makes it difficult to achieve the goal of restoring function, having long-term coverage of vital structures, and obtaining a satisfactory appearance of the lower limb. The objective of our effort then is to provide a pragmatic guide for our readers to understand the preoperative, intraoperative, and postoperative processes that will ultimately help them to develop a logical approach to lower extremity reconstruction that will more likely lead to a successful outcome.

Everyone must also understand that the management of lower extremity defects, whether complex or the most simple, is in a constant state of evolution as we are inundated daily by numerous new techniques and/or innovations that must be carefully scrutinized as to their worthiness. This has allowed the salvage of extremities today, whereas in the past amputation may have been the only alternative. For example, significant bone gaps can now be overcome by the current availability of vascularized bone grafts, Ilizarov lengthening, bone matrices, and growth factors. This coupled with new insights derived from our enhanced knowledge of anatomy like negative pressure wound therapy, tissue expansion or creep, and perforator flaps including propeller flaps has permitted superior soft-tissue coverage. Advances in microsurgery now reliably allow the use of small arteries (even <1 mm in caliber for donor or recipient site anastomoses), or similarly permit lymphatic vessel interventions that will provide better surgical solutions for lymphedema.

Any attempt at lower extremity salvage must be recognized as a long and complex process for both the medical professional and the patients and their support systems. Therefore, as physicians it is important to ensure that all patients and family members are properly informed and included in any decision-making process, ¹ while maintaining on their part an accurate awareness of the expected prognosis. This approach should impact positively on any patient’s motivation and compliance while retaining the support of the family that will be critical not only during the necessary surgeries and hospitalization but also throughout the long phases of physical and psychological recovery.

1.2 History

Many say that the best use of the present is to rely on the past to make the future. What was the best solution may still be so, and at the least it has already had a definitive outcome that can appear predictable. So, history is important, and this has been acknowledged by us in the introduction of every chapter, where that pertinent saga has been included.

The early history of lower extremity reconstruction dates back to Hippocrates (460–370 BC), when amputation was the norm, and procedures trying to improve the success of amputation and survival of life itself were the main practice up to World War I. ² Although early amputation and rapid prosthetic fitting was believed to offer the potential of faster recovery at a lower cost, recent reports have differed from this traditional viewpoint. Undeniably, the choice of reconstruction will be a more challenging path to be taken; yet, the Lower Extremity Assessment Project (LEAP) study showed no significant difference in outcome when compared to amputation at 2 years. ³ Interestingly, a cost analysis derived from this study concluded that amputation was more expensive than limb salvage, and amputation yielded fewer quality-adjusted life-years than salvage. ⁴ Other reports have shown similar findings where projected lifetime health care costs for amputation may be as high as three times that spent on limb salvage. ^{5 ,​ 6} Even if the entire lower extremity cannot be salvaged, the primary goal now should be to maintain maximal limb length with durable soft-tissue coverage of any stump that can then be fitted properly with a prosthesis that will allow a functional gait. Preservation of the knee joint as in a below-knee amputation requires far less energy consumption, and has the potential for two- to threefold greater mobility when compared to an above-knee amputation. ^{7 ,​ 8}

Not until the First and Second World Wars were pedicled flaps of some form used extensively to repair lower extremity injuries (Fig. 1‑2). Many of these had a discrete vascular supply, which today would be called “axial pattern flaps.” ⁹ Stark ¹⁰ and later Ger ¹¹ recognized that the leg muscles themselves were reliable flaps for leg coverage, having an abundant blood supply if outside the zone of injury (Fig. 1‑3).

With the advent of microsurgical capabilities, extensive and complex defects even after severe trauma and truly radical debridements could be solved (Fig. 1‑4).

In 1986, a landmark publication for reconstructive lower extremity microsurgery by Godina established the principles of early extensive debridement, immediate free tissue transfer, and aggressive rehabilitation that routinely salvaged functional limbs. ¹² Radical debridement and coverage within 72 hours compared to more delayed treatment had superior outcomes, as only 0.75% of flaps failed, 1.5% of limbs became infected, and early bony union within 6.8 months was the norm. ¹²

This dramatic deviation from established principles was followed by the development of functioning muscle transfers, ¹³ innervated flaps to regain protective sensation of the sole, ^{14 ,​ 15 ,​ 16} and tissue expansion to create a local flap option for large chronic defects ^{17 ,​ 18} or to minimize donor site morbidity. ¹⁹ By the 1990s, Koshima (Fig. 1‑5) and Soeda ²⁰ provided convincing evidence of the value of perforator flaps (Fig. 1‑6), a cutaneous flap that best ensured preservation of muscle function. The anterolateral thigh flap—first introduced by Song et al, ²¹ (Fig. 1‑7) just as Wei et al ²² Fig. 1‑8 proposed as the ideal soft-tissue flap for all purposes—is widely used worldwide today. However, currently perforator flaps in general allow better choice of a donor site that best matches the tissue qualities needed at the recipient site. ²³ Though originally utilized primarily as microvascular tissue transfers, increasingly they have become a local perforator flap option applicable to all zones of the lower extremity. ²⁴

Advances in nonsurgical alternatives should not be overlooked as well. Subatmospheric pressure devices provide a stable temporary dressing intended to promote a better environment for ultimately a skin graft or flap coverage, ²⁵ although healing by secondary intention or wound contraction may instead be possible. What the future will bring will surely encompass the pioneering fields of tissue engineering, genetic engineering, lower limb replantation or allotransplantation, and supermicrosurgery.

1.3 Basic Principles

We abhor dogma, and we would be the first to challenge any if something better were available. On the other hand, classical dictums are of paramount importance if nothing more than a guideline to at least keep us near the beaten path. Always remember that the primary goal of surgical reconstruction of the lower extremity is to restore or maintain ambulatory function. That is better assured with a well-vascularized extremity, presence of a skeletal structure able to support both necessary weight bearing and gait, and optimally an innervated plantar surface to provide protective sensation. Without restoration of proper function, the value of any attempted reconstruction will be reduced significantly, increasing both the emotional and the financial burden on the patient.

An early evaluation of the patient as a whole will allow proper decisions to be made, considering not just their overall physical condition but also their socioeconomic status and rehabilitative potential. The lower extremity injury, thus, is best approached by a team of physicians and not just surgeons, with a knowledge base including skeletal, vascular, neurologic, and soft-tissue anatomy, not to forget psychology. According to a study by Lange ²⁶ limited to open tibial fractures, absolute indications for an amputation were anatomically complete disruption of the posterior tibial nerve in adults or crush injuries with warm ischemia time greater than 6 hours. Relative indications listed were serious associated polytrauma, severe ipsilateral foot trauma, and anticipation of a protracted course to obtain soft-tissue coverage and tibial reconstruction. ²⁶ Other means for initial assessments such as the Mangled Extremity Severity Score (MESS), the Predictive Salvage Index, and the Limb Salvage Index can assist the team in making a decision for amputation, but they must never be the sole criterion in making that decision and must always be individualized for each patient. ^{27 ,​ 28 ,​ 29 ,​ 30}

The initial evaluation of a lower extremity wound requires a competent physical examination, both visual and manual, to document the location, size, depth, extent, and character of the wound. A neurological, vascular, and skeletal evaluation is essential to ascertain the extent of injuries, which helps the development of a solid plan for reconstruction (Fig. 1‑9). A thorough vascular profile using whatever clinical or diagnostic tools are available should be foremost in the examiner’s mind. Inadequate perfusion that cannot be rectified may dictate consideration in favor of life over limb preservation. Yet amputated or avulsed tissues should never be thrown away until absolutely not needed, as these may be potential donor sites for skin grafts or even flaps. ^{31 ,​ 32 ,​ 33 ,​ 34 ,​ 35} Nothing currently available can mimic the superiority of autologous tissues, no matter how they are attained.

If the vascular supply is reasonable, then stability of skeletal structures would be next in order, followed by debridement until all nonviable tissues have been removed. Only then should soft-tissue coverage be considered. This may be achieved by following the traditional concept of the reconstructive ladder, or reconstructive elevator, or reconstructive paradigm (see also Chapter 11). ^{36 ,​ 37} The simplest reconstructive option may not necessarily provide the most optimal result in the long term. Think not just about today, but also about tomorrow. Skin grafts or bioengineered acellular dermal matrices ³⁸ may be totally appropriate. Similarly, so may be local muscle or perforator flaps, but if the intent is to avoid the vagaries of microvascular tissue transfers, beware of the substandard outcome. The selection process from this cornucopia of choices is elaborated in more detail in other pertinent chapters that follow, where attributes as well as detriments are listed.

Microsurgery always has and always will have a role in lower extremity reconstruction. Recognize that any perforator flap, whether as a local or free flap, when the perforator is dissected, requires meticulous microsurgical technique Video 1.1. Traditionally, recipient sites should be chosen outside the zone of injury. ^{39 ,​ 40} End-to-side arterial anastomoses are always preferable to preserve distal flow as much as possible especially in those complex, mangled injuries seen so often in this region. ⁴¹ End-to-end venous adjacent to that of the arterial microanastomosis are logistically the most convenient, but do not hesitate to seek out the superficial venous system if the deep venae comitantes are unusable. ⁴²

Related posts:

3 Indications for Vascular Intervention in Lower Extremity Reconstruction 4 Orthopaedic Evaluation of the Lower Extremity and the Concept of the Orthoplastic Approach 11 The Pertinence of the Reconstructive Ladder and the Reconstructive Elevator 17 Supermicrosurgery Approach to the Lower Limb 18 Diabetic Foot Reconstruction 25 Lower Limb Vascularized Composite Allotransplantation

Stay updated, free articles. Join our Telegram channel

Join