Fractures of the cuboid bone are uncommon, with an annual incidence of approximately 1.8 per 100,000.1 This is largely attributed to the inherent stability provided by its anatomy and position in the foot’s lateral column, where it functions as a link between the lateral column and transverse plantar arch.2 Regarding its anatomy, the cuboid is a pyramidal-shaped bone with 6 bony surfaces that provide tremendous stability—3 of these are articular, 3 nonarticular.
Although the cuboid bone is susceptible to low-energy avulsion injuries, injuries that occur in the setting of high-energy trauma are most concerning, as they often occur concurrently with other midfoot fractures and dislocations. These less common crush injuries are associated with comminution, articular disruption, and shortening of the lateral column.3-5 Avulsion injuries occur via a twisting mechanism, while the more complex nutcracker fracture evolves via longitudinal compression of the lateral column, with the foot in a position of forced plantarflexion.6 Other comminuted fractures occur from direct impact on the lateral aspect of the foot.
Management of cuboid fractures varies according to etiology, fracture displacement, and articular involvement. Conservative management is reserved solely for stable, nondisplaced fractures.7 Unstable fracture-dislocations and those with associated lateral column shortening necessitate operative treatment, which attempts to restore anatomy, stability, and length of the foot’s lateral column.7-9 However, with the exception of open injuries, fractures tenting the skin, and injuries with concomitant compartment syndrome, the high-energy nature of cuboid fractures often precludes early surgical intervention, as the foot’s soft-tissue envelope is too compromised. For this reason, operative intervention is often performed on a delayed basis only after recovery of the soft tissue.
In this case report and literature review, we describe a reconstructive shelf arthroplasty of the fifth tarsometatarsal (TMT) joint as a primary intervention for crush-type cuboid fractures with associated joint subsidence and lateral column shortening. The shelf arthroplasty, which was first credited to Konig in 1891, has historically been described as a remodeling operation using bone graft wedges for the treatment of nonconcentric acetabular dysplasia.10 Although bone grafting is recognized as an effective means of addressing osseous voids in the setting of comminuted cuboid fractures, its specific application in the form of a shelf arthroplasty has not been described.11 The patient provided written informed consent for print and electronic publication of this case report.
An otherwise healthy 45-year-old woman presented to our institution’s emergency department (ED) complaining of right foot pain after a motor vehicle accident. She was the restrained driver in a head-on collision. Primary survey revealed a swollen, ecchymotic, and tender right foot. Radiographs demonstrated fractures of her first, second, third, and fourth metatarsals, and a comminuted cuboid fracture with lateral column shortening and disruption of the fifth TMT joint (Figure 1).
Due to swelling, initial management consisted of soft-tissue management through the use of a well-padded splint. As this was her only injury, she was instructed to remain non-weight-bearing, ambulate with crutches, and return to our outpatient office for close follow-up. The need for delayed surgical intervention of her multiple foot injuries, due to her compromised soft-tissue envelope, was discussed prior to discharge.
Surgical intervention was performed 15 days after the injury, when the soft-tissue swelling had dissipated. The surgical plan included fixation of the multiple metatarsal fractures and lateral column reconstruction and stabilization. With regard to the lateral column, we obtained patient consent for several possible procedures, including fifth TMT joint closed reduction and percutaneous pinning, open reduction and internal fixation (ORIF), and TMT joint reconstruction with iliac crest bone graft (ICBG).
The metatarsals were addressed first via a dorsomedial incision, using a 5-hole 2.7-mm Limited Contact Dynamic Compression Plate (Synthes) to stabilize the first metatarsal and 2.0-mm Kirschner wires (K-wires) to maintain the length and alignment of the second, third, and fourth metatarsals (Figure 2). Closed reduction and percutaneous pinning of the fifth metatarsal was then attempted but abandoned because of persistent instability and subsidence of the cuboid in the proximal and plantar direction. ORIF was then attempted through a dorsolateral incision extending from just distal to the sinus tarsi to the base of the fourth metatarsal. However, the lateral cuboid was too comminuted to accommodate any fixation and prevent fifth TMT joint subluxation and lateral column shortening.
Autograft reconstruction of the lateral column was therefore performed, using radiographs of the patient’s uninjured, contralateral foot as a template for our lateral column shelf arthroplasty (Figure 3). Based on this template, the length and alignment of the lateral column were provisionally maintained with two 2.0-mm K-wires placed between the fifth metatarsal and intact cuboid (Figure 4). Tricortical ICBG was then harvested through an anterior approach to the iliac crest and contoured accordingly to fill the osseous void. To facilitate graft incorporation, comminuted fragments of cuboid bone were removed, with the remaining bone decorticated. The graft was then fixed to the remaining cuboid with two 4.0-mm partially threaded cannulated screws (Synthes; Figures 2, 4). This construct restored the length of the lateral column and effectively buttressed the fifth TMT joint, preventing subsidence and dislocation of the TMT joint.