Multi-staged management of a mangled, exploded hand crush injury with long-term outcome: the critical link between surgery and therapy

Abstract

A 38-year-old right-hand dominant man sustained a severe, work-related left-hand crushing injury. A multi-staged approach to salvage was employed in conjunction with aggressive hand therapy involvement for a successful, functional outcome. Now at approximately 5 years postinjury, the patient can perform daily activities, coaches sports and has returned to and maintained his full-time work position. Mangled, severe hand crush injuries warrant immediate treatment to debride non-salvageable tissues, stabilise and revascularise the hand in an effort to maximise reconstructive potential and functional capacity. It is critical to recognise that these cases require multiple stages of operative reconstruction with direct and ongoing involvement of hand therapy and pending degree of injury, rehabilitation often lasting months to years.

Background

Crushed, mangled hand injuries are uniquely challenging cases, and may result in a poor functional outcome or even require amputation. Pending degree of injury, decision to pursue reconstruction versus amputation can be an ill-defined grey area.¹ In these circumstances, pursuing reconstruction is based on multiple factors, including surgeon’s skill level and overall experience, as well as patient factors including age, overall health and functional capacity, goals, and overall understanding of the short-term and long-term requirements of surgery and hand therapy. Initial steps to salvage prioritise stability, revascularisation and employ measures to prevent infection through timely intervention and aggressive debridement.^1–3 In these circumstances, multi-staged procedures are required to maximise reconstructive potential and overall functional capacity.

Exploded hand syndrome is a type of crush injury following significant compressive force resulting in a unique presentation of hand musculature herniation, skin fissuring and fracture.^{2 4 5} This type of injury is devastating due to the crushing nature of all bone, neurovascular and soft tissue components. Here, we present a case of a right-hand dominant 38-year-old man with a severe, compressive crush injury to the left hand secondary to a forklift accident. The purpose of this paper is to act as an educational tool for the rising reconstructive surgeon explaining the ‘when, why and how’ in a stepwise manner for preoperative, intraoperative and postoperative management to achieve a successful, functional, long-term outcome.

Case presentation

A healthy 38-year-old right-hand dominant man presented in early 2017 with an extensive high-energy, mangled crush injury to the left hand secondary to a gas-powered forklift machinery accident. The patient was ejected from the forklift secondary to roll-over, trapping his left hand between the forklift and concrete floor. Initial evaluation demonstrated significant ‘exploded’ thenar and hypothenar musculature, fractures to the index, long and ring finger metacarpals, dislocation of the small finger metacarpophalangeal (MCP) joint, and injury to the distal ulnar artery (figures 1–6) secondary to the severe compressive, crushing nature of the injury. There were no injuries to the carpus, radius or ulna. The hand and digits all showed good perfusion on initial assessment. Following a complete trauma workup and assessment, the patient consented for emergent surgery—salvage attempt versus possible amputation.

Figure 1.

Dorsal view of the traumatic left hand injury at initial presentation. Note the ‘exploded’ appearance of the musculature.

Figure 2.

Lateral view of the traumatic left hand injury at initial presentation. Note the ‘exploded’ appearance of the musculature.

Figure 3.

Volar view of the traumatic left hand injury at initial presentation with associated soft tissue avulsion.

Figure 4.

Anterior X-ray view of the traumatic left hand injury at initial presentation.

Figure 5.

Lateral X-ray view of the traumatic left hand injury at initial presentation.

Figure 6.

Original artistic rendered line diagram by author SRA, demonstrating the degree of sustained injury and pertinent associated anatomy.

Multi-stage surgical evaluation and treatment

Initial surgical assessment

The initial surgical assessment focused on damage control with irrigation, debridement and identification of salvageable tissue. Prior to tourniquet placement, perfusion was evaluated under anaesthesia where the hand and all fingers demonstrated stable flow. The avulsed palm skin flap was carefully debrided back to healthy viable-appearing soft tissue. The adductor pollicis and flexor pollicis brevis were avulsed from their proximal attachments. These avulsed thumb intrinsic muscles were gathered and sutured back in anatomic position. The palmaris longus tendon and palmar cutaneous branch of the median nerve were completely destroyed beyond repair.

Focus was then shifted to evaluation of the ulnar aspect of the hand. The distal aspect of the ulnar artery was found to be avulsed at the level of the wrist and thrombosed. The tourniquet was taken down, and adequate perfusion of the hand and digits (ie, through the palmar arch) was confirmed again; the ulnar artery was therefore deemed not to require reconstruction. Guyon’s canal and the carpal tunnel were then released to prevent compression on regenerating nerves and healing structures. The ulnar nerve sensory and deep motor branches were traced and found to be intact. The median nerve within the carpal tunnel was contused but the distal branches were intact and in continuity. The hypothenar muscles were avulsed off their distal attachments; sutured back and reattached into anatomic position. Fasciotomies were performed to decompress the remaining compartments of the hand.

The initial plan was to stabilise the numerous fractures with application of an external fixator; however, the hand was too unstable given the fractures and dislocations sustained across all metacarpals. The long and ring finger metacarpal fractures were highly unstable; their fixation was augmented with intramedullary K-wires for stability. This restored a somewhat stable central axis of the hand and thereby significantly improved the ability to reduce and stabilise the remainder of the hand with external fixation. Next, two Schanz pins were placed into the distal radius as a proximal anchor point for external fixation stability. Additional Schanz pins were placed in the index, long and ring fingers and connected to the external construct as shown in figure 7. The small finger’s MCP joint was dislocated dorsally and closed reduction was not possible; therefore, open reduction was performed to facilitate extrication of the interposed volar plate. The ruptured small finger’s MCP collateral ligaments were directly repaired. Postoperative, occupational hand therapy was consulted to establish care for direct and ongoing involvement.

Figure 7.

Left hand external hardware fixation.

Assessment of soft tissue injury: debridement and flap reconstruction

Following initial operative ‘damage control’, multiple additional surgeries were performed to debride demarcated tissues, particularly at the site of the avulsed palmar skin flap, which fully demarcated. A few days later, the patient returned to the operating room (OR) for evaluation of critical soft tissues within the initial zone of injury. Debridement left the thenar muscles and neurovascular palmar arch structures were exposed. An ulnar artery perforator-based Becker flap was dissected, mobilised and rotated into place to resurface and cover the palmar arch with healthy fresh vascularised soft tissues. A split thickness skin graft was used to cover the remaining non-critical soft tissue deficits at the base of the wrist. The flap maintained good perfusion and the forearm flap harvest site was closed primarily.

External hardware removal and soft tissue evaluation

Approximately 6 weeks after initial surgery, the external fixator was removed. Further debridement of volar and dorsal wounds was performed at this time. Dorsally, a local rotational flap was used to provide adequate soft tissue coverage at a site where soft tissue had demarcated around a Schanz pin site on the dorsal hand, resulting in extensor tendon exposure. ACell MicroMatrix (ACell, Columbia, MD, USA) powder was applied to the remaining superficial open wounds to help stimulate tissue and secondary healing. The patient subsequently went on to heal all wounds.

Surgical release of extensor contractures

Despite ongoing intensive hand therapy, the patient developed severe stiffness with extension contractures involving the MCP joints and extensor tendons to all four digits. The small finger’s proximal interphalangeal (PIP) joint and flexor tendons were also extremely stiff with limited excursion. Approximately 5 months after the initial injury, the patient returned to the OR for surgical releases. The surgery was performed with a wrist block and intravenous sedation, to allow the patient to actively test the releases intraoperatively. The extensor indicis proprius (EIP), extensor digiti minimi and extensor digiti communis (EDC) tendons to the index, long, ring and small fingers were identified and circumferentially tenolysed. Meals tenolysis knives were used to perform tenolysis from the hand proximally into the forearm and also distally onto the fingers.

Next, the dorsal MCP joint capsules were sharply incised serially, and partial capsulotomies and partial collateral ligament releases were performed to restore full passive flexion. Lumbrical tenolyses were performed to improve the lumbrical-plus deformities, and small finger flexor tenolyses were also performed. Anaesthesia was lightened and the patient showed greatly improved active range of motion, which was further tailored intraoperatively. Active range-of-motion exercises were initiated immediately postoperatively; formal hand therapy was resumed on postoperative day one.

Long finger metacarpal non-union

Approximately 7 months after injury, additional X-ray and CT imaging of the hand demonstrated non-union of the long finger transverse fracture, resulting in persistent focal pain and instability contributing to altered biomechanics and a recurrent extension contracture. After discussion with the patient, the decision was made to return to the OR for surgical management of the non-union and further tenolysis.

The EIP and EDC tendons to the index, long and ring finger were tenolysed again, and the dorsal exposure was used to treat the long finger metacarpal shaft non-union. The dissection was carried down subperiosteally to the long finger metacarpal. The previously placed intra-medullary (IM) nail was removed, the non-union site was debrided back to healthy bleeding bone and the volar angulation deformity was corrected.

Autologous cancellous bone graft was then taken from the dorsal distal radius and applied to the metacarpal defect. A 2.4 mm Synthes plate was contoured and placed dorsally over the fracture site. Once alignment was confirmed with fluoroscopy the plate was secured using a combination of bicortical locking and cortical screws. Successful reduction and plate position were confirmed with fluoroscopy (figure 4). The non-union bone graft correction went on to heal uneventfully.

Anti-claw hand tendon transfer

Despite continued maximal hand therapy, the patient developed significant clawing of the injured hand affecting all four fingers and significantly limiting his grip function. Evaluation demonstrated a positive Bouvier test, so the decision was made to return to the OR for anti-claw tendon transfers using the Zancolli ‘Lasso’ procedure, along with flexor tenolysis. Two incisions were used, including a transverse palm-spanning incision through the distal palmar flexion crease and also a separate transverse counter incision in the proximal palm (along the distal edge of the prior Becker flap, just distal to the carpal tunnel). The flexor digitorum superficialis (FDS) tendons of the long and ring finger were identified distally and sharply transected. These two tendons were then retracted into the incision at the level of the carpal tunnel. These two FDS tendons were split axially to provide four total FDS slips. Using a tendon passer, each FDS slip was passed through a fibro-osseus canal to each of the four fingers. Through the distal incision, each FDS slip was passed through the A1 pulley of the respective finger, looped back through the distal A1 pulley and onto itself proximally, and tensioned to reverse the claw-deformity of that finger. The tendon transfers were woven and sutured into place with focus on strength or repair to allow for immediate postoperative therapy. A dorsal blocking brace was used to protect the tendon transfers with the MCP joint flexed, while allowing immediate active tendon gliding mobilisation of the tenolysed flexor tendons at the distal and PIP joints. This intervention resolved the clawing and improved range of motion and grip strength.

Thumb intrinsics reconstruction and further tenolysis

At the 2-year mark after initial injury, clinical examination revealed mild recurrence of the MCP joint extension contractures and complete absence of active thumb adduction. Despite initial attempts at salvage repairs of the thumb intrinsic adductor musculature, these crushed avulsed muscles went on to fibrose and become non-functional. The long finger metacarpal fracture site was well healed in good alignment, but the patient had some discomfort at the dorsal metacarpal plate site.

The patient returned to the OR to address the above issues. Revision extensor tenolysis was performed again and the plate was removed. The small finger’s PIP joint was very stiff on examination so thorough revision release was performed on the small finger’s extensor and flexor tendons as well as the PIP joint checkrein and collateral ligaments.

Attention was then turned to the thenar compartment to address the loss of thumb adduction. Given the extent of the initial injury, the adductor pollicis and first dorsal interosseous muscles had undergone post-traumatic necrosis and fibrosis. For thumb adductorplasty, a tendon transfer was performed using the index finger’s FDS tendon, which was harvested distally, re-routed to the thumb through a pulley window created in the index A1 pulley and woven through the thumb adductor insertion. It was tensioned tightly with the wrist extended and sutured back to itself. The thumb showed markedly improved thumb adduction with passive tenodesis wrist flexion and extension. Following a course of hand therapy, the patient demonstrated greatly improved thumb and finger function.

Correction of small finger adduction deformity

Approximately 2½ years after initial injury and numerous reconstructive surgeries, the patient developed significant discomfort in the small finger. Necrosis and fibrosis of the avulsed small finger abductor digiti minimi hypothenar muscle (which failed initial attempts at reconstruction) resulted in and unopposed small finger adduction deformity. This small finger adduction deformity affected his ability to open his hand for large object grasp, and also made donning gloves very difficult. He therefore elected for a small finger abductionoplasty tendon transfer. In order to facilitate tendon transfer, the contracted radial aspect of the MCP joint was released together with the adduction contracture. The small finger’s EDC tendon was sharply transected at its insertion on the proximal phalanx and then rerouted and transferred ulnarly through the ulnar MCP insertion of the abductor digiti minimi tendon. Following a course of hand therapy, the patient demonstrated greatly improved small finger and hand opening function.

Outcome and follow-up

Long term follow-up at 5 years postinjury

Now at approximately 5 years postinjury, the patient is overall doing well with continued improvement in performing activities of daily living and associated hobbies. Soft tissue coverage has remained stable. When making a loose fist, the tips of the digits touch the palm with some limited flexion of the MCP. The patient displays smooth tendon gliding in both active and passive range of motion. Total active range of motion in degrees is 145, 270, 270, 235 and 170 for the left thumb, index, middle, ring and small finger, respectively (figure 8, table 1, video 1). Sensation at the tips of the digits on a scale of 10 with 10 being normal sensation, reports 8, 7, 6, 6 and 5 for the thumb, index, middle, ring and small finger, respectively. Grip strength of the left hand is 41 lb, compared with the unaffected right hand at 110 lb. The patient has returned to and maintained his prior full-time work position and is overall pleased with the operative outcome of the hand.

Figure 8.

Anterior X-ray view of the left hand at 5-year follow-up.

Table 1.

Range of motion (in degrees)

	Left thumb	Left index finger	Left long finger	Left ring finger	Left small finger
MPJ	+10 to 70	−20 to 70	−10 to 80	−15 to 70	0 to 50
PIPJ	0 to 85 (IP joint)	0 to 100	0 to 110	+15 to 100	+10 to 85
DIPJ		0 to 80	+15 to 85	0 to 65	+15 to 60
Total active motion (TAM)	145	270	270	235	170

Video 1.

Disclaimer: this video summarises a scientific article published by BMJ Publishing Group Limited (BMJ). The content of this video has not been peer-reviewed and does not constitute medical advice. Any opinions expressed are solely those of the contributors. Viewers should be aware that professionals in the field may have different opinions. BMJ does not endorse any opinions expressed or recommendations discussed. Viewers should not use the content of the video as the basis for any medical treatment. BMJ disclaims all liability and responsibility arising from any reliance placed on the content.

bcr-2021-248429supp001.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2021-248429.video01

Discussion

Hand injuries represent as much as 12% of all trauma cases presenting to emergency departments in the USA.⁶ Mangled hand injuries involving a ‘crush’ mechanism represent a constellation of skeletal and soft tissues injuries that require prompt evaluation and multi-staged operative reconstruction. Due to the nature of crush presentations, the true extent of injury cannot be entirely defined on initial presentation. Delay in inflammatory reaction lends to a wide zone of injury, initially misrepresenting the extent of involvement.^{3 7} Higher metabolic requirements of proximal injuries (such as an entire hand vs a single digit) are less tolerant to ischaemia.¹ Therefore, prompt initial assessment and operative management are crucial as devascularised muscle has a limited warm ischaemia survival time period of 4–6 hours.^{1 7}

The initial surgery was focused on early operative intervention to achieve skeletal stabilisation, optimise perfusion and debride clearly non-viable tissue. Skeletal stabilisation is essential to provide a fixed length construct for any necessary immediate or delayed neurovascular repair, and also prevent kinking and twisting of tenuous vascular structures which can result in further ischaemic insults. Staged debridement allows for demarcation and prevents the sacrifice of potentially viable tissue that could be used in later reconstruction efforts. The degree of optimal debridement is oftentimes unclear at the initial presentation and can sometimes be far more significant than anticipated. After initial salvage is completed, next-stage surgery and postoperative management focuses on restoration of function—and depends critically on the integration and support of skilled hand therapists.

This case is an example of the important link between surgery and therapy. Initial surgery in this case provided the foundation and stability for intensive therapy, and subsequent surgeries were performed to address functional limitations. Extensive scarring, joint contractures and soft tissue adhesions are a hallmark of crushing injuries. Therefore, many of the subsequent surgical and therapy needs centred around tenolyses and joint releases for which therapy was initiated immediately postoperatively to leverage immediate tendon gliding to limit recurrent adhesions. Despite these plans, the degree of injuries and potential for recurrent scar adhesions necessitated several revisions of tenolyses and joint releases to achieve an optimal and functional result. Functional evaluation in therapy was crucial to driving the surgical planning and overall outcome.

Similarly, in major mangling injuries, standard tendon transfer donor options may be dwindled by the scope of the injury, or depleted for other necessary tendon transfers. Therefore, flexible approaches may sometimes be required. In this case, we found it necessary to use the long and ring finger FDS tendons for anti-claw tendon transfers to all four fingers. We subsequently used the index FDS tendon to provide a thumb adductorplasty tendon transfer, and then completed his care with re-routing tendon transfer of the small finger’s extensor tendon to the ulnar MCP insertion of the adductor digiti minimi to provide small finger abduction on hand-opening activities.

These cases often require a significant amount of patience on behalf of the patient, surgeon and therapist, as the sequence of reconstruction will require stable soft tissue and healing for functional optimisation. It is paramount to counsel these patients early and often on the staged approach and the importance of hand therapy to keep them engaged on their pathway to optimal final results.^{5 8 9} For significant crushed, mangled hand salvage candidates, we recommend a multi-staged approach with direct involvement of hand therapy with close and consistent follow-up to facilitate operative guidance in effort to achieve a successful functional outcome.

Learning points.

• Mangled, crush-related hand injuries are extremely complex and complicated cases.

• Decision to pursue salvage versus amputation is reliant on many factors, including: surgeon’s skill and experience, patient’s needs and/or goals, overall health status and functional capacity, commitment, and compliance.

• Reconstruction requires a multi-staged approach, working closely with dedicated hand therapy specialists as their input is invaluable to guiding operations as well as overall functional outcome.

Ethics statements

Patient consent for publication

Consent obtained directly from the patient(s).