Introduction
Mutilating injuries have diminished greatly as a result of improvements in workplace conditions and safety measures and huge fines to the industry when regulations are broken. Nevertheless, we still see cases associated with machine repair and traffic and domestic accidents. Domestic accidents can be devastating and are often caused by machines meant for professional use that are actually used for “do-it-yourself” projects. Children are also often injured by these machines, as well as by firecrackers. Though most of these accidents are preventable, the fact remains that we often see mutilating hand injuries and should know how to deal with them. In this chapter, three hand surgeons explain their approaches for thumb and finger reconstructions.
Thumb and finger reconstruction (Francisco del Piñal)
I will summarize herein my approach for injuries to the hand with missing parts. I have divided this information into two main sections: Reconstruction of the thumb, which has a unique role in hand function, and reconstruction of the fingers. The latter is further subdivided by mutilation type. It should be stressed that this is not a surgical atlas, and only the basics of the anatomy will be discussed. I will focus more on the indications and intricacies of the procedures. The techniques should be further examined in the famous Buncke, O’Brien and Morrison’s, Wei-Mardini’s, or Jones’ textbooks of microsurgery.
In short, my focus in this chapter will be the ways in which hand reconstruction has evolved in my career. The main goal in surgery is to make a hand that is going to be used by the patient. If the patient does not understand that his or her cooperation is crucial for the end result, all of our efforts are in vain. Although the saying “smart surgery is for smart people” seems politically incorrect, through my many years of practice, I have learned that, unfortunately, the statement is true. I advise not to pursue surgery in patients who have not accepted their injury or who seem to be uncooperative. Contrarily, I do not dismiss: smokers, drinkers, overweight individuals, or those with diabetes or other chronic conditions, provided they are fit for the surgery (most of my surgeries are performed under local blocks). I have been pleasantly surprised by apparent “problematic patients” who were cooperative and had a complete turnaround in their lives after the procedure. Smoking is prohibited in the hospital, and I advise patients not to smoke during the reconstruction. Most patients comply with these instructions. I warn patients with comorbidities that they may have more damaged vessels and face challenging vascular complications. I also reassure them, however, that the risk of losing the part is very slim. (We have lost three toes in about 550 toe transfers in an unselected population, with no exclusions.)
The thumb (Francisco del Piñal)
Despite the impossibility of discussing every aspect of thumb reconstruction, I believe it is crucial to understand the goal rather than perform surgery in a nonsensical manner. Thus the surgeon must have a goal in mind and propose it to the patient, who must in turn understand the goal, price (in body pieces), and risks. (Actually, this statement holds true for all plans in my practice.)
I usually opt for toe transfers, and for typical losses of the proximal base, the operation devised by Dr. Fu Chan Wei (trimmed toe transfer) is my preferred choice. If the patient strongly opposes transfer of the hallux (as in one or two cases that I can recall), then I offer the second toe and advise that the result will not be as good. I admit, there are other ways of reconstructing a thumb, such as bone distraction or pollicization, but, except for “on-top plasty” under special circumstances, my method of choice is a toe transfer. I am so convinced that patients will be unhappy with the alternatives that I decline other forms of reconstruction except in special circumstances; if a patient is set on an alternative method of reconstruction, I recommend they seek treatment elsewhere ( Fig. 25.1 ).
Basic anatomy
The details of the operation can be found in the original paper and also in textbooks on microsurgery. The variable arterial anatomy faced in other toe transfers (second toe transfers, tandem toe transfers, etc.) can complicate the dissection and disrupt planning. In the normal foot, the hallux and second toe are vascularized by the plantar and dorsal system in a competitive manner ( Fig. 25.2 A). Usually, there is a proximal communicating artery (deep plantar branch of the dorsalis pedis artery [DPA]) and a distal communicating artery (DCA). The DCA is, in turn, formed by the first plantar and first dorsal metatarsal arteries and divides into the dorsal digital arteries (usually hypoplastic) and the larger plantar digital arteries (peroneal digital artery of the hallux and tibial digital artery of the second toe). Variations in the arteries exist ( Fig. 25.2 ). In the early days, most textbooks recommended a long artery transfer, where the hallux (or second toe) is pedicled on the DCA–first dorsal metatarsal artery–dorsalis pedis axis. In this way, an endless arterial pedicle could be used. Unfortunately, there are many anatomical variations. The most well-known was described by Gilbert and others. They noticed that this ideal “long artery axis” was sometimes unusable because the first dorsal metatarsal artery could be deep in the muscle, hypoplastic, or absent. As such, surgeons often deal with short pedicles. This is just a part of the gamut of variations, however, and with experience, one will see all types of variations, including, but not limited to, an absent dorsal arterial system, absent plantar arterial system, absent dorsalis pedis, and absent plantar digital artery. In addition, there are acquired deformities, such as obstruction of the plantar systems (usually in very healthy people, sometimes because of repetitive trauma when jogging) and obstructed arteries from tobacco use, hypertension, or any other cause associated with atheromatous arterial damage. Such variations will enormously complicate the operation and, in my practice, occur in around 3% to 5% of cases. Far more frequently (in about 40% of my cases), the surgeon faces challenges associated with short pedicles.
I do not see many of these variations because, in most cases, I use the digital artery. However, I do not recommend this to the novice surgeon. A long pedicle will permit the surgeon to go far from the area of injury and perform safer anastomoses with larger vessels. Conversely, it is more destructive to the foot, and the dissection is more time consuming. Purposefully or not, the surgeon will often face the “short pedicle.” I usually handle this by performing anastomoses with a digital artery at the base of the recipient thumb or finger; if there are no arteries there, I either swing the radial digital artery of the index to the base of the thumb or, in other digits, use a graft (preferably an arterial graft) to jump to the anatomical snuff-box, a common palmar digital artery, or another location away from damage ( Fig. 25.3 ).
Choice by level of amputation
Classically, the thumb has been divided into three areas to indicate the preferred type of reconstruction: The distal, middle, and proximal thirds ( Fig. 25.4 ).
While it is commonly accepted that distal third amputations do not require a toe for reconstruction, my experience is completely radical. These patients perform poorly and are deeply concerned about the loss. Furthermore, the locking effect of the thumb’s distal phalanx (the so-called “vice grip,” as termed by Buncke and Valauri) is also lost. For this reason, these patients are much better served using a customized hallux transfer, which yields high satisfaction and minimal donor-site morbidity. , , In my practice, this is indicated not only for musicians and “delicate young ladies,” but also for manual workers and any patient who is interested in recovering a nearly perfect thumb and understands the procedure. I do not make exceptions for smokers or those with other adverse conditions, provided they can withstand the operation. Smokers are counseled to refrain from smoking in the immediate postoperative period, and I find that they usually do well for up to a couple of weeks. Despite this unselected population, the possibilities of failure are very low (in my experience, three cases in more than 500 toe-to-hand transfers) ( Fig. 25.5 ).
Surgery involving a partial toe is not an easy procedure, and the surgeon must be familiar with handling small vessels and anastomoses to achieve a good cosmetic result. The dissection must go to the tip of the hallux to reduce the bone in the sagittal and coronal planes because the hallux is much larger than the thumb. The ipsilateral hallux is preferred, as this permits the dominant artery and nerve to be oriented along the ulnar side of the thumb. Veins are dissected first, and this is greatly facilitated if there is some blood in the veins; hence, we elevate the tourniquet without applying an Esmarch bandage. Inclusion of the whole nail greatly facilitates harvesting, as large dorsal veins forming proximal to the eponychial fold can be included. Contrarily, harvesting a partial nail obliges one to dissect the veins of the lateral aspect of the pulp, which are minute, fragile, and easily torn. An alternative recently recommended is to include the volar veins. Regarding arterial inflow, in most cases, I only harvest the peroneal digital artery. This speeds up harvesting at the price of a smaller vessel for the anastomosis. Most importantly, it minimizes donor-site morbidity. Utmost care is taken to identify, isolate, and ligate a constant branch proximal to the neck of the proximal phalanx. If this is missed or avulsed, the blood supply to the transfer may be endangered ( Fig. 25.6 ).
All authors agree that middle-third amputations deserve a surgical effort. Several methods have been proposed (lengthening, pollicization, osteoplastic), but my first choice is a trimmed toe transfer as described by Wei et al. In this manner, a closer replica of the thumb is achieved, the risk of bone resorption is nonexistent, and there is motion preserved at the interphalangeal (IP) joint. Conversely, the second toe is a poor replica, and its small size provides a smaller surface for opposition. Even in children who have had their thumb amputated, my preference is the hallux. The only drawback of transplanting the hallux is the donor site. While in cases of distal amputations the donor site is very acceptable, in proximal amputations, the donor site is very offensive to most patients (and surgeons). For the latter cases, I move the second toe to the hallux position and increase the girth of the second toe with a tibial flap from the hallux. This creates a much more acceptable donor site.
I should stress the importance of early reconstruction, no later than the first week, in all hand mutilations. This makes the procedure much easier technically and shortens the time the patient is away from their duties. Delaying the procedure may give the patient time to mourn the loss and thus appreciate the achieved result, but doing so will unnecessarily prolong the time off duty and, above all, make the procedure much more difficult. Furthermore, early coverage of the stump—with the toe—allows one to preserve structures without the need for temporary flaps. The surgery is smoother, and, in turn, the donor-site requirements from the foot are diminished. By the same token, emergency toe transfers do not allow the patient to understand the procedure and the entailed risks; thus I do not recommend this either. Contrarily, emergency surgery may be an ideal occasion to construct a thumb with tissues that would otherwise be discarded.
Proximal-third losses are the least common, but the problems presented are enormous. Not only does the surgeon have to provide a neo-thumb distally, but the thenar loss must also be addressed; this implies the need for: Coverage, substitution for the thenar and fist web muscles, and 5 cm of bone to restore the length of the first metacarpal.
Several methods have been proposed, including osteoplastic reconstruction topped with a toe. , However, the reconstructions are extenuating for the patient, which causes a high incidence of dropout in the course of the reconstruction process. Pollicization can restore the thumb, even if the carpometacarpal (CMC) joint is lost. Apart from the obvious drawback of the loss of the index finger, in my experience, this operation will inevitably lead to a worker’s retirement. Furthermore, performance of pollicization is quite dependent on the remaining muscles, and the function achieved in proximal amputations, with loss of thenar muscles, “is little more than [that of] a post.”
Thus toes are probably the best option for proximal amputations. However, since the metacarpal is also needed, absence of the hallux in the foot would cause gait disturbances and is not recommended. The second toe does not have that problem, but it provides a poorer replica and has a tendency to claw, a short nail, and a smaller surface available for opposition. We have circumvented the issue of harvesting the hallux, minimizing donor site morbidity, by the “switching-two-toe transfer” (STTT) ( Fig. 25.7 ). This flap is a variation of the twisted-two-toe flap of Foucher, permitting us to restore any length necessary for the thumb and obtain a closer thumb replica without endangering the foot. The flap is composed of a trimmed hallux plus the second metatarsophalangeal (MTP) joint and the second metatarsal bone. The hallux is based on the peroneal digital artery, whereas the second metatarsophalangeal joint and the second metatarsal bone are based on branches from the distal communicating artery and the tibial digital artery of the second toe. The distal second toe circulation is thus based on the remaining fibular digital artery, which should be carefully preserved. Proximally, the dissection can stop at the first dorsal or plantar metatarsal artery depending on dominance. The “thumb” is built on a side table by switching the proximal phalanx of the hallux on top of the base of the proximal phalanx of the second toe. Fixation is performed with 90/90 wiring.
The foot is closed by transferring the second toe to lie on top of the proximal phalanx of the hallux. Dissection of the components of the STTT flap is discussed in the paper, and the reader is referred there. Most importantly, when building the neo-thumb, the second MTP joint should not be twisted into position, as recommended by Foucher, but instead switched across. In other words, the MTP joint should be transposed beneath the hallux rather than rotated 180 degrees around the hallux. Otherwise, the MTP joint would be reversed, which creates sidewise instability during pinch functions. (Note that, despite the fact that the literature recommends rotating the MTP joint 180 degrees to increase its arc of motion, this is a mistake; it will cause sidewise instability on the transferred joint).
Coverage issues
Skin coverage is always a problem. To prevent desiccation and further loss of vital remaining structures, it is essential to provide healthy coverage. Most authors favor cover with a pedicled groin flap, as this gives abundant tissue and some extra time for planning.
Short muscles
A normal thumb requires seven tendons to control the three thumb joints. If there are fewer, such as in cases involving paralysis, a Z-collapse deformity will occur. A reconstructed thumb will behave similarly. Thus at the time of reconstruction, the surgeon must judiciously use arthrodesis and transfer of available motors to prevent a useless neo-thumb ( Fig. 25.8 ). Though tendon transfers may be needed, I have found that the only way to achieve a “normal” functioning thumb is by preserving the original intrinsic muscles. Staging reconstructions will render the muscles unsalvageable and will skyrocket the need for the transfer of tendons, which may not be available. This is, without doubt, the main advantage of immediate reconstruction and has not been sufficiently stressed in the literature. Delaying the reconstruction will lead to functional loss of the important intrinsic muscles ( Fig. 25.9 ).
Absence of the basal joint proves a major challenge. The workhorse is pollicization because it is the only option that will recreate a basal joint, but consideration should be given to tendon transfers and good coverage to prevent the uneasy situation of a useless reconstruction. Perhaps combining our current understanding of immediate reconstruction to preserve local muscles and of tendon transfers is the answer. Currently, guided by my main motto of adding rather than removing from a damaged area, I prefer an STTT and arthrodesis of the second metatarsal to the trapezoid in very proximal amputations. This approach reduces the number of tendons needed to control the thumb, which in most very proximal amputations are also markedly limited ( Fig. 25.10 ).
During thumb reconstruction, major attention should be paid to the first web, and its reconstruction deserves great thought. A contracture at this level will convert the neo-thumb into a useless structure. If there is no skin shortage, web contracture can be prevented by using progressive casting, thus avoiding secondary surgery. A catastrophic scenario occurs when there is soft tissue damage in the web and there is no thumb to put a splint on. In such cases, I give high priority to transplanting the toe and restoring the web at the same time. The web itself has a very special tridimensional structure, and I have found that only another web can restore its pliability and appearance. Sometimes, happy coincidences can be found, and the surgeon can take advantage of any “discardable tissue” ( Fig. 25.11 ).
The fingers (Francisco del Piñal)
While planning reconstruction of the isolated “average” thumb loss is relatively straightforward, the mutilated hand is, in general, a challenge. To prevent disappointment, a plan of the reconstruction and the expected outcomes should be presented and discussed with the patient and family. This will help them to understand the goals, methods, and time the reconstruction may take. In cases involving complex injuries, I have found that having the patient talk to former patients with similar injuries is extremely helpful to decrease fear and anxiety.
The goal depends on the original injury but can be summarized by upgrading what is left. In the early 2000s, I introduced the concept of the “acceptable hand”: a hand with three fingers, mobile at the proximal IP (PIP) joints, with normal sensation and a normal thumb. , The classification has been slightly modified, but the concept holds true in my practice. I find it useful to think of it as escalating from scratch and adding elements to upgrade the hand while also taking into account the importance of the hand’s appearance. The fingers should describe a uniform arcade, without central defects, contour irregularities, or “sausage fingers.” Any of those may make the hand a problem for the patient and will cause it to be hidden and unused. Furthermore, we have to consider the donor site. I am reluctant to harvest more than two lesser toes from each foot or two lesser toes and the hallux from the contralateral foot. It is true that, in metacarpal hands, we can reconstruct all four fingers and the thumb by transferring two tandem second and third toes. However, the aesthetic result is far from normal. The toes are too short, and, as a result, the hand looks squared, without the normal curvature of the fingers, in a somewhat similar way to the short-fingered hand of an individual with symbrachydactyly. In those cases, I prefer other alternatives such as a “tripod-plus” hand.
Taking all data into account, I find the following downgrading scale useful: (near)-normal, acceptable, tripod-plus, tripod, basic, and carpal ( Fig. 25.12 ). One should try to upgrade the hand from the preoperative status, adding the maximum number of elements without sacrificing too much of the foot.
Foremost is the (near)- normal hand . It has four fingers with (near) normal length and sensation and a normal thumb. This is only possible for minor injuries. The defect may have not only a cosmetic impact but may also be functionally very limiting. Particularly, when it is painful, the index finger may stick out and bang into things everywhere, thus severely interfering with normal hand use ( Fig. 25.13 ). In this group, I also include patients who have had central amputation (very noticeable) and who wish to be “normal.” There are obviously also professionals, such as musicians, for whom loss of just a small finger part can curtail their careers. The indication is also very high in manual workers when the level of amputation is distal to the PIP joint and they wish for a near-normal hand.
An acceptable hand is the minimum goal the surgeon should strive for in the search of normalcy. We named this type of hand as acceptable because it is so from functional and aesthetic standpoints. Few will notice the lack of one finger in an acceptable hand. An acceptable hand should have three fingers with normal motion at the PIP joints, at least protective sensation, as much length as possible distal to the proximal IP joint, and, most importantly, harmonious finger lengths ( Fig. 25.14 ). As long as one is able to provide an acceptable hand, the patient will likely be happy and the result very functional.
Preservation of the PIP joint is an important issue, and the level of amputation changes the management. In my experience, toes move poorly in the hand; thus it is crucial to preserve as many original joints as possible, which will be the key to a good functional result. Secondly, toes are much shorter than fingers, so if one takes into consideration the importance of restoring the finger arcade, a single finger amputated proximal to the PIP joint should have a ray amputation rather than a toe transfer. Contrarily, fingers amputated distal to the PIP joint benefit enormously from toe transfers. , Not only do toes in this scenario restore the arcade of the hand but, because the native PIP joint is preserved, good range of motion will be restored ( Fig. 25.15 ).
When two or more fingers are amputated proximal to the PIP joint, ray amputation has no role. In those circumstances, the trade-off of arthrodesis at the PIP joint, even in central amputations, is acceptable to most patients. More severe injuries call for compromises, and loss of range of motion at the PIP joint but restoration of digital length and the shape of the hand is very acceptable to many patients ( Fig. 25.16 ).
Moving on to more severe injuries, the next classification is the tripod-plus hand ( Fig. 25.12 ). This concept has evolved from the traditional tripod pinch to a thumb plus three elements to oppose with—obviously not as satisfactory as the acceptable hand. The tripod-plus hand is much more functional than the tripod hand and less objectionable. Needless to say, the longer the fingers the better, and restoration of the arcade is a must ( Fig. 25.17 ).
A tripod pinch has three elements: a thumb plus two opposing fingers. This type of hand reconstruction was promoted to give more stability to a “basic pinch” (in vogue at the time), , and secondarily to the increase of popularity of the second-third tandem transfer. In the tripod hand, the ulnar digit supports the radial, providing a much stronger pinch, and the ability to grasp large objects is dramatically improved. This was revolutionary compared to the standard of care for the metacarpal hand known as the “ basic hand ” or “ pincer .” Basically, this was a lobster type of pincer, which provides a weak pinch and minimal grasping ability but is generally socially unacceptable. Presently, the indications for the latter in my practice are limited to bilateral metacarpal hands. If possible, we should upgrading from those types of weak pincers to tripod or tripod-plus hands ( Fig. 25.18 ).
