Faculty Bibliography

The surgical and anatomic features pertinent to lower extremity nerve injury are reviewed. The common problems associated with specific nerve lesions are discussed and reparative recommendations are offered. A more informed, aggressive approach to lower extremity nerve repair is suggested.

The evolving areas of microsurgery pertinent to hand surgery are briefly described and outlined. The spectacular developments in the recent past are merely glimpses of what may yet be ahead for hand surgery. This is illustrated by a science fiction story of the management of an amputation injury in outer space in which many of the currently evolving technologies are employed.

A hundred years ago, the question of whether to amputate a severely injured extremity could be answered rather easily and did not pose a serious dilemma. However, the increasing reconstructive capabilities have permitted the retreat to amputation to be made less frequently and occasionally create a dilemma concerning the best means of securing optimal function for the traumatized extremity. The surgeon must carefully balance the extent of trauma with the likelihood that his or her reconstructive efforts would surpass the functional results afforded by prompt amputation and prosthetic fitting. Although the mechanisms of limb destruction have changed in the past 2 centuries, the fundamental dilemma confronting the trauma surgeon has remained unchanged. In the words of Samuel D. Gross: "The cases which may reasonably require and those which may not require interference with the knife are not always so clearly and distinctly defined as not to give rise, in very many instances, to the most serious apprehension ... that, while the surgeon endeavors to avoid Scylla, he may not unwittingly run into Charybdis, mutilating a limb that might have been saved, and endangering life by the retention of one that should have been promptly amputated."

Safe planes exist for plantar incisions that minimize the possibility of subcutaneous nerve injury and are therefore useful in flap design. Nerve branch orientation in the plantar subcutaneous tissue is specific and guides dissection so as to avoid producing anesthesia in weight-bearing areas. An extensive proximal plantar subcutaneous plexus exists that permits elevation of plantar flaps in a superficial plane. This is due to the major contribution that the dorsal circulation makes to the skin of the plantar surface. The blood supply to the non-weight-bearing midsole area is not from the medial plantar artery exclusively. This is a watershed area with important lateral plantar artery and dorsalis pedis artery contributions as well. It is not necessary or desirable to base plantar flaps on a myocutaneous or fasciocutaneous supply with its required deep dissection. Local plantar flaps can be designed to include sensation and abundant blood supply without the need for "subfascial" dissection. Subcutaneous sensory plantar flaps designed in accordance with these principles promise a more ideal solution for the treatment of plantar defects.

Foot injuries constitute a spectrum of problems that can be classified by severity. The development of successful techniques for the treatment of lower leg injuries has made the severity of a concomitant foot injury a key factor in determining the overall salvageability of the leg. A more complete classification of foot injuries is therefore needed and has been proposed. Preoperative assessment of foot injuries differs in the acute versus the delayed presentation. The acute case requires evaluation of wound conditions, exposed structures, and associated proximal injuries. The chronic injury requires gait analysis, study of weight-bearing patterns by Harris mat prints, skeletal evaluation, mapping of plantar sensation, and, in some cases, angiography. Thorough knowledge of foot anatomy is essential for developing a rational plan for treatment. The significance and course of the medial calcaneal nerve and the anatomy of the plantar nerves have not been fully appreciated in most reports on the treatment of foot injuries. The recognition of the proximal plantar subcutaneous plexus blood supply has modified the understanding of plantar flap design. It has simplified and improved the safety of dissection of sensate plantar flaps. A plethora of both local and distant flap options exist for the treatment of foot injuries. The foot is divided into four major areas based on different requirements for reconstruction and the types of flaps available. These areas are the proximal plantar area; the malleoli, Achilles tendon, and posterior (non-weight-bearing) heel area; the distal plantar area; and the dorsum. The options for coverage have been discussed in detail, and a summary of the reconstructive strategy by area has been presented in Table 3. Complex (type III) injuries are special injuries owing to their severity and multiple components. They require a careful initial evaluation for both feasibility and advisability of extremity salvage. Treatment of these injuries consists of bony stabilization and soft-tissue debridement followed by flap coverage.

Laser Doppler flowmetry (LDF) has been found useful in monitoring free flaps. In the present study, waveform analysis has been applied to the LDF waveform. Waveform changes were investigated in the microcirculation during varying degrees of arterial or venous occlusion in the saphenous island and flap of the dog and the human digit. The quantitative analysis of laser Doppler flowmetry waveform allows for the diagnosis of arterial occlusion or venous occlusion and their differentiation.

Lower extremity trauma often results in significant skin or contour deformities as a result of the tissues destroyed. Such deformities are poorly tolerated by most patients, especially younger women. To achieve a satisfactory aesthetic reconstruction, the surgeon must be familiar with the special anatomy of the lower extremity as well all the different reconstructive options at his or her disposal. Minor scars or contour deformities can be corrected by traditional methods of scar revision or serial excision. Tissue expanders or silicone implants have a somewhat limited role in the lower extremity as compared with elsewhere in the body. Most major defects require free flaps to replace the surface or contour. Because of the importance of aesthetic results in the legs, free flaps should be utilized more often during the original trauma surgery if their use is deemed necessary for aesthetic reasons (Case 6).

A submandibular space abscess is reported in which a pure culture of Actinobacillus actinomycetemcomitans was identified. The bacterium may often be overlooked as a pathogen due to its slow growth and its requirement for carbon dioxide for primary isolation. As A. actinomycetemcomitans is often resistant to commonly used antibiotics, proper management is based on careful utilization of microbiologic tests and clinical judgement. In this case prompt surgical drainage and appropriate antibiotic therapy resolved the abscess.