Temporary ectopic banking as a treatment option for mangled thumb: a case report

Abstract

Background

Management of the extensive soft tissue injuries remains a significant challenge in orthopedic and plastic reconstructive surgery. Since the thumb is responsible for 40% of the functions of the hand, saving and reconstructing a mangled thumb is essential for the patient’s future.

Case presentation

This case report describes the management of a severe occupational thumb injury in a 25-year-old white Persian male who sustained an occupational injury to his left thumb, resulting in extensive burn, crush injury to the distal and proximal phalanx, and severe soft tissue damage to the first metacarpal, thenar, and palmar areas. Necrosis necessitated amputation through the first metacarpophalangeal joint. Postdebridement observation revealed a viable first metacarpal bone but was exposed due to a lack of soft tissue. Given the wound contamination and infection risk, the first metacarpal bone was banked in the distal forearm. After a 4 week period of antibiotics, irrigation, debridement, and vacuum dressing, the thumb and soft tissue reconstruction were performed, retrieving the viable first metacarpal. The first metacarpophalangeal joint fusion was achieved with an intramedullary screw and two K-wires. A reverse adipofascial radial artery forearm flap and skin grafts from the left thigh were used for soft tissue reconstruction.

Conclusion

This case highlights the importance of a flexible, staged approach to hand trauma, emphasizing the utility of ectopic banking and reconstructive techniques in managing complex hand injuries. This report contributes to the ongoing dialogue on optimal strategies for hand reconstruction, particularly in cases where traditional immediate reconstruction is not feasible.

Introduction

The management of severe hand injuries, especially those involving amputations and extensive tissue damage, presents a significant challenge in the field of reconstructive surgery [1, 2]. The thumb, essential for a myriad of hand functions such as grasping, pinching, and manipulating objects, is particularly critical [3, 4]. A thumb loss or dysfunction can impair up to 40% of hand function, highlighting the importance of effective reconstruction strategies [5]. Traditional methods such as immediate replantation often encounter obstacles such as instability of the hemodynamics or unsuitable recipient sites, necessitating innovative approaches such as ectopic banking. This technique, first introduced by Godina et al., involves the temporary relocation of amputated parts to preserve their viability until conditions are favorable for replantation or definitive reconstruction [6].

Ectopic banking has significantly evolved since its inception, now encompassing not only single extremity injuries but also multiple extremities and other body parts, adapting to multiple settings where complex injury patterns may occur [7, 8]. The preservation of soft tissues and bones is vital for successful long-term outcomes, particularly in managing infections that require extensive debridement of soft tissues. The integration of ectopic banking with advanced microsurgical techniques, such as the reverse radial forearm flap, has significantly enhanced the potential for functional restoration in severely mangled hands [9].

This case report details the application of temporary ectopic banking of bone followed by reconstruction using a reverse adipofascial radial artery forearm flap in a patient with a severe occupational thumb injury. This staged approach highlights the necessity of a multidisciplinary strategy in managing complex hand injuries [10]. By exploring this case, we aim to contribute to the ongoing dialogue on optimal strategies for hand reconstruction, emphasizing the critical importance of preserving both tissue viability and bone structure to restore function in the context of severe hand trauma.

Case presentation

A 25-year-old white Persian male sustained an occupational related injury to his left thumb. Factory machinery caused extensive burn and crush injury to the distal phalanx and proximal phalanx and further severe soft tissue damage to the first metacarpal of the left thumb and the thenar and palmar area of the left hand (Fig. 1A). The patient had no previous history of a significant injury to his left upper limb. On admission, the patient was prescribed intravenous cefazolin 1 g every 6 hours (q6h) and gentamycin 80 mg q8h. After extensive debridement of the hand in the operative room, we found that the first metacarpal bone is viable, but there was no soft tissue supporting it, leaving the metacarpal bone exposed (Fig. 1B). Considering the necrosis of the distal and proximal phalanxes, we decided to perform amputation through the first metacarpophalangeal (MCP) joint (Fig. 1C and D). Given the contamination of the wound and high risks for infection, we could not perform primary soft tissue reconstruction for the metacarpal bone and the thenar and palmar area. We banked the first metacarpal bone in the distal forearm for later reconstruction (Fig. 2). Postoperatively, the patient developed signs of local infection, but wound and fluid cultures turned out negative. So, with a consultation with the infectious ward, the patient was prescribed intravenous ciprofloxacin 400 mg q12h and clindamycin 900 mg for the first dose, then 600 mg q8h. Through a 4 week postoperative period, antibiotic therapy, three sessions of irrigation and debridement in the operating room, and vacuum dressing were performed. The patient had physiotherapy sessions for maintaining the range of motion of the remaining fingers.

Fig. 1

Occupational injury to a 25-year-old man’s left thumb. A Burn and crush injuries to distal and proximal phalanges, severe necrosis soft tissue damage to the first metacarpal, thenar, and palmar areas. B Postdebridement, the first metacarpal bone is viable but lacks supporting soft tissue, leaving it exposed. C Amputation through the first metacarpophalangeal joint. D Complete debridement

Fig. 2

X-rays showing the first metacarpal bone banked in the distal forearm for later reconstruction. A Lateral view. B Posterior–anterior view

Finally, the infection was controlled, and granulation tissue was formed in the bed of the wound. The patient was brought to the operation room for the thumb and soft tissue reconstruction. We retrieved the first metacarpal bone from the forearm, and fortunately, the bone was viable. Considering the fact that there was no soft tissue to support the first MCP joint, we decided to perform fusion of the joint in the functional position (30° flexion, 30° abduction, and slight pronation) by an intramedullary screw and two K-wires. The Allen test was performed to ensure sufficiency of the forearm arteries. Soft tissue reconstruction of the first metacarpal bone and the thenar area was performed by a routine reverse adipofascial radial artery forearm flap. The donor site and the rest of the soft tissue reconstruction was performed by a skin graft which was harvested from the left thigh (Fig. 3A and B).

Fig. 3

A, B Immediately after metacarpophalangeal fusion operation with soft tissue reconstruction of the first metacarpal bone and thenar area by reverse adipofascial radial artery forearm flap. C, D Five weeks later, the patient demonstrates the ability to grasp an object after physiotherapy sessions

The patient was discharged 2 days later with no complications regarding the flap. He was visited 2 weeks later for evaluation of the skin grafts and donor site. As we were reassured of the viability of the soft tissue reconstruction, physical therapy sessions were initiated for the patient with a focus on daily functions of the thumb such as opposition and pinching (Fig. 3C and D).

Three months after the final surgery, bony union was seen in the fusion site (Fig. 4). The patient was followed for 9 months, with no complications observed during the follow-ups (Fig. 5). After extensive physical therapy sessions, complex functions were restored to a reasonable level. He can now pick up objects, such as a pen, with his reconstructed thumb and write on paper (Supplementary Video 1). The patient used his reconstructed thumb daily and expressed satisfaction with the results of the operations.

Fig. 4

X-rays showing the fusion of the first metacarpophalangeal joint in a functional position using an intramedullary screw and two K-wires. A Lateral view. B Posterior–anterior view

Fig. 5

A, B The 9 month postoperative visit. Fisting is observed

Discussion

In this case report, we detail the treatment of a severe occupational thumb and hand injury in a 25-year-old male, which involved extensive burn and crush injuries. The treatment strategy was multifaceted, including amputation, temporary ectopic banking of the first metacarpal bone, and subsequent reconstruction using a reverse adipofascial radial artery forearm flap and skin grafting.

The novel aspect of our approach is highlighted by the ectopic banking of a metacarpal bone, a distinctive adaptation of the traditional ectopic implantation technique primarily used for soft tissue. This step not only preserved the viable bone for later reconstruction but also provided a crucial timeframe for managing the wound, preparing for successful flap coverage and, ultimately, ensuring a more functional reconstruction in complex thumb trauma.

Ectopic banking, a technique first described by Godina et al. [6], where amputated parts are temporarily attached to another part of the body to preserve their viability, has been extensively validated and discussed as a viable option for managing severe hand injuries in which immediate replantation is not feasible [8, 11]. This technique, which can be used for both soft tissue and bone, allows for the preservation of tissues of various sizes that might otherwise be lost, providing a window for planning definitive reconstruction. The use of ectopic banking in traumatic injuries of larger parts, such as the hand and the use of other recipient sites such as the ankle, has been described in literature [6, 12, 13]. Our case, utilizing ectopic banking of a metacarpal bone and later using it for reconstruction, is similar to the technique described by Yang et al., where bony phalanges from a nonreplantable amputated thumb were used for secondary thumb reconstruction [14]. It is important to note the distinction between ectopic and heterotopic replantation, as highlighted by Trapero et al. [15]. Ectopic replantation, as used in our case, involves temporarily storing an amputated element in an uninjured, nonanatomical, and nonfunctional position for later replantation. This differs from heterotopic replantation, which involves replacing an amputated part in a different but related location to the native site, often to improve functional outcomes.

The reverse adipofascial radial artery forearm flap, as used in our case, is a well-established technique for hand reconstruction. Several studies have demonstrated its reliability and effectiveness in providing soft tissue coverage and vascular support [16,17,18]. This flap is particularly advantageous due to its reliable vascularity, ease of harvest, and minimal donor site morbidity [16, 19]. Our case further supports the utility of this flap in the context of traumatic injury managed by ectopic implantation and secondary replantation. The adipofascial type of reverse radial forearm flap, compared with osteocutaneous and fasciocutaneous types, offers additional use flexibility with a lesser degree of donor site morbidity but may require more complex surgical planning and execution [16].

Other flap techniques for hand and digit reconstruction include the use of the groin flap [8, 11], the posterior interosseus artery flap [20], and the free ulnar forearm fasciocutaneous flap [21], to name a few. These techniques offer alternative solutions for soft tissue coverage and vascular support, each with its own set of advantages and limitations. The groin flap, for example, while providing ample soft tissue, may be less favorable due to the bulkiness and potential for donor site morbidity [18].

Valerio et al. have discussed the use of ectopic banking in military trauma, where multiple extremity amputations pose significant reconstructive challenges [22]. Our case contributes to this body of evidence by demonstrating the successful use of ectopic banking and secondary replantation in a civilian context, highlighting the technique’s broad applicability.

Celestin et al. [23] provide a flowchart for utilizing temporary ectopic replantation in upper extremity injuries, which aligns with our approach. They highlight that this approach provides time for multiple debridements, facilitates patient resuscitation, and allows for better planning of the reconstruction process. This can lead to improved operative efficiency and potentially better outcomes. In our case, the ectopic banking of the metacarpal bone provides similar benefits, allowing for wound management and preparation for the definitive reconstruction.

The reconstruction options for the mangled thumb may be broadly categorized into replantation/revascularization or complex reconstruction utilizing simple or complex microsurgical flaps, with our treatment falling into the latter category [1]. Other salvage treatment options for the mangled thumb include composite free tissue transfer, such as toe-to-thumb transfer [24,25,26], pollicization [27], metacarpal lengthening by distraction osteogenesis [28, 29], and osseointegrated thumb prosthetic replacement [30]. Each of these methods comes with its own set of advantages and limitations, with varying degrees of validation and evidence. For instance, toe-to-thumb transfer provides a favorable functional outcome but involves significant donor site morbidity and a complex surgical procedure [24]. Innovations in tissue engineering and regenerative medicine also hold promise for improving outcomes in hand reconstruction [31].

There are several limitations to this case. The technical complexity of the procedure requires a high level of surgical expertise and experience, which may not be available in all clinical settings. The long-term outcomes and potential complications need to be monitored over an extended period. The success of this approach in a single case may not be universally applicable, and further studies are needed to validate its efficacy across diverse patient populations and injury types.

Future studies should focus on evaluating ectopic banking of bony parts against immediate reconstruction through comparative studies to better define its role and efficacy. Investigating the utility of this approach in other severe hand injuries could broaden its application. More research should focus on long-term outcomes of traumatic thumb injury reconstructive techniques, including functional and aesthetic results. Comparative studies between different flap techniques or reconstruction strategies would provide valuable insights into the most effective approaches for various types of hand injuries. Scrutinizing the optimal timeline of ectopic banking and replantation can help further fine tune the details of this method.

Conclusion

This case report demonstrates the effective use of temporary ectopic banking of the first metacarpal bone and subsequent reconstruction with a reverse adipofascial radial artery forearm flap for managing a severely mangled thumb. This approach facilitated successful infection control, bone preservation, and functional restoration, highlighting the importance of a flexible, staged approach to hand trauma, particularly in complex cases where traditional immediate reconstruction is not preferred. It underscores the necessity of multidisciplinary management and the potential of ectopic banking as a valuable tool in the reconstructive orthoplastic arsenal.