Principles of management of crush injury.
This chapter details crush injuries of the hand as opposed to crush syndrome. The definition along with the spectrum of injury is described including a historical review of the causative mechanisms to help in the understanding of basic pathomechanics. The main menu comprises Clinical Assessment, Management and Outcomes, where the reader is taken through the steps one by one on how to approach such an injury, from the history, examination and investigations pointing out important aspects. Basic facts and figures to know and memorize have been placed in an easy-to-absorb format of tables and highlighted boxes. Key points are emphasized, and important aspects of management as well as those simple tips to improve outcome are given to ease the novice as well as the tempered surgeon’s encounter. A special section on management of specialized tissue is given toward the end after the basic management is dealt with so that a deeper understanding is gained and applied. Possible outcomes would alert the surgeon on both adverse events to avoid and excellent results to aim for. As always, good functional outcome is sought after but a good cosmetic appearance should be constantly filed away in mind’s eye to enhance the final result.
- mangled extremity
Crush injuries of the hand pose a challenge to even the most accomplished hand surgeons whether it is a minor fingertip injury sustained by getting squashed in a closing door or a high-pressure compression injury involving the palm or wrist.
2. Clinical presentation
The crush injury may present from the tip of the finger to proximally right up to the arm. Although the management of more proximal and therefore potentially life-threatening injuries is precluded from this chapter, we will deal briefly with their management. There are certain principles in the management of all injuries be they minor or major (Table 1), and these have to be adhered to, especially if it is a high-energy trauma as in a road traffic accident (RTA) or a fall from a height.
Thus, the primary aim in any trauma is to stabilize the patient and rule out any life-threatening injuries. Airway, breathing and circulation must be first secured. Subsequent management will focus on the limb at hand and its systemic sequelae. After the early treatment and resuscitation of the patient, antibiotic and tetanus cover is ensured and the hand surgeon alerted for further assessment.
2.1. Clinical assessment
2.1.1. Functional anatomy of the hand
The hand is basically composed of two types of skin, thick palmar glabrous skin and thin dorsal skin. As can be seen in Figure 1E, the dorsal skin is thin, loose, mobile and stretchable. The palmar side, however, is thickened for protection with papillary ridges to increase the surface area as well as improve the grip. These ridges form our finger prints. The fingers are highly innervated to provide a two-point discrimination of 4–6 mm at the fingertip, as measured by the two-point discriminator disc (2-PD: Figure 1F). The sweat glands give lubrication to aid in feeling and function (Table 2).
|Palmar skin||Dorsal skin|
|1. Specialized glabrous epithelium||Nonglabrous, hirsute|
|2. Thick cornified surface||Thin|
|3. Immobile skin||Mobile|
|4. High-density sensory receptors||Less dense|
|5. Subcutaneous pulp||Nail matrix & plate|
There are numerous flexure creases to anchor the skin down, and with the palmaris brevis muscle, they aid in holding and gripping objects. The muscles of the hypothenar and thenar eminences allow specialized functions of opponens, abduction, adduction and flexion (Figure 2).
The injury may be small involving just the digits or the hand, or it may be more extensive including the wrist and even the forearm. It may even be segmental with intervening areas of normal tissue. It may be open or closed, with associated elements of degloving or avulsion. They may be either clean as in door jamb injuries or obviously dirty as the trash compactor or farm injuries. One must also be alerted to marine-related open wounds with their own peculiar pathogens (
The patient’s occupation, associated medical conditions and allergies if any, and dominant hand should be recorded. A mental or written note of the patient’s expectations would complete the history.
Initial assessment in the emergency room can be conducted while obtaining the history from the patient and observing the hand posture, cascade (Figure 4), color as well as assessing flexor and extensor mechanisms even without exposing the wound. Local anaesthesia should only be given
|2. Resurfacing with skin graft|
|3. Reconstruct with flap (local or free)|
|4. Revision amputation|
|5. Rehabilitation—potential prosthesis/orthosis|
In order to make the choice to replant, reconstruct or amputate, a number of factors have to be taken into consideration (Table 4). These deciding factors will influence the surgeon’s final decision.
|General factors||Local factors|
|1. Age||1. Circulation|
|2. Circulatory stability||2. Sensation|
|3. Life-threatening conditions||3. Tendon movements|
|4. Associated medical problems||4. Loss of skin|
|5. Injury to contralateral limb||5. Loss of bone & joints|
|6. Time lapse—warm & cold ischemia tissue||6. Loss of specialized tissue|
|7. Mechanism of Injury|
2.1.4. General factors
The patient’s general condition is of prime importance in making a decision since an elderly patient in hypovolemic shock would not be able to tolerate further ischemic insult in terms of prolonged operative time and potential blood loss implicated in reconstruction or limb salvage. Similarly, a patient with diabetes would be more prone to infection and complications. In contrast, severe crushing to a contralateral limb would necessitate more extreme measures to attempt salvage. There has been no consensus achieved yet on the maximum time an amputated part of a limb can tolerate ischemia and gain good functional postreplantation. Many factors are involved such as ambient temperature, collateral circulation and level of amputation. Many attempts have been made to assist in this decision-making process but none are ideal. Although MESS (Table 5: Mangled Extremity Scoring System) was initially developed for the lower limb , it has subsequently been applied to the upper limb as well with some degree of success, provided one knows its limitations [2, 3]. In this score, a total of six implies the limb is salvageable, while seven or more advocates amputation. The score, however, does not take into consideration other major injuries causing hypovolemia, associated medical conditions, injuries to the other limbs that may necessitate salvage, nerve injuries and the type of damage sustained, and a more subdivided range of ages. The latter is important in that an infant would have better nerve regeneration capabilities than an adult, whereas a 90-year-old would have less cardiovascular reserve than a 50-year-old, both situations not being differentiated. The exact mechanism of injury (crush, avulsion, guillotine), as well as the amount of force, its velocity & the width of the offending object are all important factors in decision-making. Smith et al. suggested three contraindications to major replantation, namely brachial plexus avulsion, severely mangled extremity and an excessive ischemia time . There have been many advances since then to overcome some of these obstacles, for example, highly innovative developments in the field of neuromuscular prosthetics; however, brachial plexus avulsion remains challenging. There will come a time though when an equilibrium will be reached in the two arms.
|Skeletal/soft tissue injury|
2.1.5. The five P’s
The most important aspect in the assessment of the limb will be the
Pulselessness and additionally a
Pain, paresthesia and paralysis may not be detected in the head injured patient, patients that are heavily sedated, or those with brachial plexus injuries. Pallor may be unreliable in certain situations such as hypovolemic shock, massive blood loss, pigmented individuals and compartment syndrome. Dyes and other coloring materials as well as grease have to be scrubbed off in order to properly assess the circulation. Other parameters such as capillary refill, bleeding on pin prick, and transcutaneous oxygen pulse pressure may be used as an adjunct in the assessment.
2.1.6. Specific structures
3.1. Preoperative assessment
After a relevant detailed history and thorough examination, the patient is worked up for the operative procedure. The assessment is targeted to evaluating his general condition and co-morbidities if any, and locally to the injury concerned. The pre-operative laboratory tests would depend on the hospital policy, the patient’s age and associated medical conditions if any. Thus, while the older patient (above 40 years of age) would require a chest film, electrocardiogram, full blood count, glucose levels and renal function, the younger patient may do with just the blood counts.
3.2. Surgical treatment
The primary aim of management is to save life, limb and then restore limb function in that order. After that, the aim must be to achieve a function better than that offered by a prosthesis. The principles of replantation and hand reconstruction (Table 6), however, are very stringent and demanding for there is little room for error.
3.3. Radical debridement
The hand surgeon’s greatest enemy is infection secondary to inadequate debridement and lavage, cited by Wang et al. as the most common cause for failure of survival . It follows therefore that the most important step after the initial assessment is meticulous and thorough debridement of all devitalized tissue and foreign bodies to convert a dirty contaminated wound into a clean surgical wound.
Prior to starting surgical debridement, the wound should be adequately irrigated with copious amounts of saline, povidone-iodine (Betadine) and hydrogen peroxide. Some authors have advocated a concoction of the three in a ratio of five parts to one to one, respectively . Washing with gentamycin either neat or diluted with saline is also practiced by some, although clinical support for this is not convincing. Pulsatile lavage has also been advocated as has rigorous scrubbing with a brush. Ultimately, the aim is to get the wound clean
Tomaino said “débridement must be consummate, as if ablating tumor” . Therefore, shredded tendon pieces and avulsed nerve without axonal elements must be excised. Similarly, bone pieces without any muscular or tendinous attachments should be removed. Although difficult to replace some tissue types (such as tendon, nerve and joints), retention of these contaminated or devitalized tissues may result in more harm than good. Whether to debride under tourniquet control or not is dependent on surgeon’s preference. No doubt, the surgical field is much clearer with the tourniquet up, but one has to consider tourniquet time, especially if it is a replantation. Preferably, the skin edges should be débrided with a sharp instrument such as a blade without the tourniquet to assess skin, subcutaneous, muscle as well as bony viability. When it comes to fine dissection and meticulous débridement; for example, around vessels and digital nerves, the tourniquet could be inflated for that particular period. Of course, preferentially, tourniquet control is used for repair of bones, arteries & veins, tendons, and nerves in that order. The use of diathermy should be restricted and drains avoided (Table 7). The wounds should not be closed under tension, and if highly contaminated, delayed primary closure is entertained. If in doubt, a second look and repeated débridements should be carried out. Emergency free flaps have been found to have a higher rate of success with fewer numbers of procedures. They prevent desiccation of tissue & reduce infection, thus ultimately improving the function and eventual outcome .
3.4. Management of specialized tissue
Once the wound has been thoroughly débrided, a secondary inspection should be carried out to assess the damage sustained and the best course of action to be undertaken. Reid classified mutilating injuries of the hand into (1) dorsal injuries, (2) palmar injuries, (3) radial hemiamputation, (4) ulnar hemiamputation, (5) distal amputation, and (6) degloving injuries . Das De et al. preferred assessment of injuries to be based on damage sustained in terms of tissue components—bone & joints, tendon, muscles, nerve, vessels, and skin—involving different anatomical parts . Although various authors have used different anatomical classification areas (e.g., Tomaino—dorsum of hand, volar forearm and thumb-index web ), we feel division into digits, midhand, wrist and forearm is simple and useful both anatomically as well as functionally. The various tissues will still have to be considered individually in each of these areas.
3.4.1. Skeletal stabilization
Bones provide the stability and skeletal framework to which the soft tissues are attached while joints offer mobility to the hand and digits. When damaged severely as in crush injuries, the hand becomes flail and thus useless and repair of the skeleton has to be undertaken before soft tissue reconstruction proceeds. It is therefore essential that fracture fixation is adequately performed primarily and is
Sometimes in severe comminution in the
Severe damage to the
3.4.2. Tendon repair and reconstruction
Distal anchorage of tendons can be difficult and various ways have been devised to overcome the problem. The steel suture with a button is traditionally used for zone 1 FDP injuries. Newer methods include mini-Mitek screws with swaged sutures for both flexor and extensor tendons . These provide firm anchorage to the proximal phalanx, carpal bones and small structures via a 1.8 or 2.0 mm screw and sutures swaged to it to reattach the severed tendon. A very recent product in the market is the absorbable JuggerKnot® soft Anchor 1.0 mm mini where there is no metal implant hence no chance of irritation to adjacent tendons (Figure 17).
Crushed, contused, contaminated and frayed muscle fibers should be excised to prevent infection. Retention of these would cause fibrosis, contracture and stiffness . Ischemic muscle similarly should be excised. This problem is frequently encountered with the intrinsic muscles of the hand, and special thought should be given intraoperatively since inadequate excision will subsequently interfere with tendon excursion. A “burst laceration” of the first web space also demands
Of all the tissues that are damaged, nerve recovery is the worst, even in the best of circumstances. We have made advances in the repair and reconstruction of bone, soft tissue and vessels, but nerve repair remains a challenge. Perhaps biological options may be the way to go in the future—these are promising results . At present, a clean cut nerve in a young patient with the best repair possible may still not recover full function. The functional outcome of nerve repair depends on the
Once skeletal stability is obtained, repair of arteries should take precedence over the veins especially when ischemic time is of importance. This may not be evident in the digits, but in the
3.4.6. Skin and subcutaneous tissues
“Tendons, nerves, joints and bones cannot be left exposed to the outside world and when infected cause sloughing, purulent arthritis, osteomyelitis, months of dressing and final crippling. All vulnerable parts should be protected from such fate by covering them over and the wound closed, thus saving months of invalidism, compensation and industrial waste, and big permanent disability.” These prophetic words written by Sterling Bunnell in Surgery of the Hand in 1944 still stand true to this day.
3.4.7. Resurfacing options
In resurfacing a loss of skin and subcutaneous tissue in the hand, the choice option will depend on the
The reconstructive ladder (Table 8) as referred to by Levin was designed from the simplest option to the technically most demanding . The best option, however, still has to consider the above-mentioned factors and may differ from surgeon to surgeon. With a small sized wound of less than 1 cm2,
|Grafting—split or full thickness|
The principles of hand resurfacing (Table 9) demand that skin should be replaced by like for like, meaning glabrous palmar skin should ideally be replaced by glabrous skin. The skin on the
|Replace like skin for like skin|
|Mobility over dorsum of hand|
|Availability of tendons on dorsum|
|Durability (glabrous) and sensibility|
|Contouring of web space and fingers|
|Specialized structures e.g., nail complex|
|Preferably compatible vessel size|
|Avoid dependent state e.g., groin flap|
|Good donor morbidity|
4. Learning from outcomes and case examples
4.1. Fingertip injuries and amputations
These are by far the most common hand injuries seen in the emergency and may range from a simple laceration to a complete amputation of the fingertip. The anatomy of the fingertip may be accessed in many esteemed publications but the basic components that are the bone, the overlying nail bed and the volar pulp. As mentioned before, the scaffold must sustain the structure, thus it is imperative to achieve bony stability.
4.2. Digital amputations
Without doubt, amputations are challenging to the junior as well as the senior surgeon and the difficulty increases the more distal it is. Although replantation is the most obviously best option if it is possible and there are a number of good articles on the technique [34, 39, 40], a revision amputation may be performed with some tips and tricks in mind to maximize the function. In a ring avulsion injury where the skin and subcutaneous tissues are avulsed and the bone plus tendinous structures are intact, or not (Urbaniak II, III), a ring skin graft may be applied (Figure 23) and the use of some regenerating agents may prove to be helpful . Wherever possible, the proximal interphalangeal (PIP) joint should be preserved, for a prosthesis is more functional at this level. Replantation of digits with amputations distal to the FDS insertion do better as opposed to zone 2 ones and Urbaniak advocates amputation . In these instances, placing a full thickness skin graft in a ring fashion may be helpful because it is firmly adherent on its base, provides a good cosmetic outcome and is relatively easy to perform. Alternatively, an abdominal flap may be fashioned (Figure 19) or a venous flow through free flap, in increasing degrees of difficulty.
4.3. Multiple fractures and soft tissue injuries
The key is to stabilize the bony structure as sturdily and speedily as possible. Once that is achieved, the soft tissue elements will fall into place and be relatively easier to repair and reconstruct. The servile Kirschner wire may prove to be very useful as do the miniexternal fixators from LINK®. It is extremely useful to master Lister’s technique as well as polishing one’s skills in applying a (minilocking) plate. We have found using bone grafts (synthetic) may aid tremendously in filling up gaps and aiding the healing process. Restoration of blood supply or minimizing use of the tourniquet is also a tip to remember. In a number of cases of forklift injury to the hand where multiple comminuted fractures occurred in one hand, we used a combination of plates, screws and external fixators to attain rapid stabilization of the skeleton (Figure 24). Damaged flexor and extensor tendons were also repaired in the same sitting.
5. Poor functional outcome
A poor outcome is unintentional and part of a learning curve that a surgeon goes through. There are certain pointers to avoid, which ensure known complications (Figure 25) do not occur. Amongst these are:
a poor history, neglecting to ask the mechanism, the ischemic time and if the patient smokes!
insufficient radiographs depicting the extent of injury
inadequate wound debridement of devitalized and crushed tissue leading to delayed healing and infection
infection causing fibrosis, scarring and contracture, a sure sign of stiffness
insufficient strength of repair of structures (such as nerve, tendon and bony stabilization) to start early active rehabilitation
poor vascular bed and perfusion leading to iii as well
inadequate soft tissue cover especially over hardware or incorrect choice of implant size
placing fixation through the germinal or sterile matrix resulting in nail deformities
malunion in terms of angulation or rotation—1° of MC rotation results in 5°of fingertip malrotation  and 5° of MC rotation ends up with 1.5 cm digital overlap , thus fixation has to be very precise
malunion in terms of shortening—2 mm of MC shortening produces a 7° extension lag, while 1 mm of P1 shortening gives a 12°-extension lag 
skin closure under tension will result in ischemic and necrotic tips
poor hand immobilization.
Thus as can be seen, most of the adverse outcomes can be avoided. The hand surgeon has a multitude of options in resurfacing the hand. Though there are challenges to be overcome, present day microsurgical and other techniques together with biological options offer the hope of good functional outcome in crush injuries to the hand.
These are devastating injuries that are daunting; however, after the patient is stabilized and initial first aid is administered, the assessment should provide a checklist of what is damaged, and what is available for reconstruction; this would include what may be “scavenged” from the parts that are not reattachable—such as skin, parts of bone, even tendons nerves and vessels. The most challenging part is for the surgeon to accept that a “normal” hand will not result but we must remember that if almost all is lost, whatever we salvage is a plus point. Having said that, there are some main points to bear in mind—the goal should be the “greatest total benefit for our patient” , which may be different in various countries, cultures and beliefs. Clear communication, an idea of what is feasibly possible and the likely end result are some of the factors to bear in mind when discussing options with the patient and their relatives.
Roohi SA would like to thank Prof. Dr. Lim Beng Hai for his guidance as well as the use of some of his work in the figures as acknowledged. With gratitude to great teachers: Drs. Gill RS, Shukur MH, and Pathmanathan V.
Conflict of interest
The authors declare no conflict of interest and have not received any remuneration or benefit from any entity for the writing or publication of this article.
Appendix & nomenclature
|ADM:abductor digiti minimi|
|DIPJ:distal interphalangeal joint|
|FDP:flexor digitorum profundus|
|FDS:flexor digitorum superficialis|
|MESS:Mangled Extremity Scoring System|
|MVA:motor vehicle accident|
|P: phalanx 1: proximal, 2: middle, 3: distal|
|PIPJ:proximal interphalangeal joint|
|ROM:range of motion|
|RTA:road traffic accident|