Cuboid fractures are an uncommon occurrence in sports. Isolated cuboid fractures are rare because cuboid fractures typically occur in combination with other midfoot fractures or dislocations.1 A 5-year study demonstrated an annual incidence of mid-foot fractures as 3.6 in 100,000 per year in the United Kingdom, of which the cuboid accounted for 50% of all midfoot fractures.2
The cuboid bone has six surfaces, four of which articulate with surrounding bony structures (Figure 1). This is vital in supporting the lateral column of the midfoot and maintaining the alignment and length of the lateral aspect of the foot, which includes the calcaneus, lateral cuneiform, and fourth and fifth metatarsals. Additionally, the articulation of the cuboid bone with the fourth and fifth metatarsals makes the largest contribution to dorsiflexion and plantar flexion of the midfoot, allowing for adaptation to uneven surfaces.3 In fact, the four or five metatarsal-cuboid joints provide as much as three times the plantar flexion/dorsiflexion motion compared with the medial tarsometatarsal joints4 and are a primary contributor to pronation and supination of the foot, whereas the calcaneocuboid joint makes a further contribution to a lesser degree.5
Anatomy of the foot. Published with permission from Winterstein AP. Athletic Training Student Primer: A Foundation for Success, Third Edition (pp. 111–142). © 2018 SLACK Incorporated.
The nutcracker mechanism of injury to the cuboid bone was first described by Hermel and Gershon-Cohen in 1953.6 According to Fenton et al,5 in this injury, axial forces transmitted through the fourth and fifth metatarsals lead to failure of the cancellous bone of the body of the cuboid bone but are insufficient to produce additional injury elsewhere in the midfoot. Additionally, due to the strain on the insertion of the tibialis posterior during extreme forefoot abduction, avulsion fractures of the navicular bone can be associated with the nutcracker fracture of the cuboid bone.7
The proper care for these fractures begins with recognition from a heightened index of suspicion for the typical injury pattern, leading one to careful examination and then appropriate imaging to properly identify the problem. Comprehensive ankle and foot examination should specifically include careful direct palpation of the midtarsal bones and stress evaluation of the tarsal segments evaluating stability of the midfoot. Fractures of the cuboid bone can be detected on plain radiography with anteroposterior, lateral, and medial oblique views of the foot,8 but nondisplaced fractures can be missed. If suspected based on examination, magnetic resonance imaging (MRI) or computed tomography (CT) scan can improve visualization. However, findings of a nutcracker type injury may be subtle. MRI can delineate injury with increased signal on T2 sequences, and the fracture line can be determined if decreased signal is present on T1 imaging. A CT scan provides improved visualization of the fracture pattern and evaluation for shortening, which plays a key role in determining treatment recommendations.4 There is no universally accepted classification specifically for cuboid fractures; however, Fenton et al5 reported a classification system describing pattern and typical mechanism of injury.
Management strategies include casting or immobilization, external fixation, open reduction and internal fixation with or without bone grafting, and midtarsal fusion.3 Operative intervention is advised when there is lateral column shortening or articular displacement usually greater than 1 mm.3 Failure to correct shortening of the lateral column usually leads to instability, pes planus deformity,4 early arthritic changes, and compensatory eversion of the hindfoot.9 In a case series of 13 patients with extra-articular cuboid fractures where the lateral column was maintained and cuboid articulations remained intact, none of these patients underwent surgical treatment.9 Nondisplaced fractures of the cuboid bone can be treated conservatively with cast/boot immobilization and then a progressive rehabilitation treatment plan.
The purpose of this report is to present the case of a collegiate football player who sustained an isolated cuboid fracture via the nutcracker mechanism while participating in a collegiate football practice session.
A 22-year-old male football player hyperplantarflexed his ankle when he was tackled. He had immediate and progressive worsening pain with activity. On initial examination, he could not fully bear weight, push off, or ambulate without difficulty. There was full active range of motion of the ankle and no effusion but pain over the lateral ankle and foot. Ankle anterior drawer, inversion and eversion talar-tilt, and Kleiger tests were negative. Midfoot torsion testing was painful. No point tenderness was noted at the fifth metatarsal, the navicular bone, or along the medial and lateral malleoli. Resistive muscle testing was within normal limits for dorsiflexion and plantarflexion, but resistive eversion caused pain. The athlete was treated with rest, ice, compression, and elevation (RICE), walking boot, and non-weight-bearing on crutches. He was referred the next morning to the team orthopedist for further evaluation.
Radiographs were obtained, revealing a transverse fracture to the cuboid bone (Figure 2). A CT scan was ordered to further delineate the fracture (Figure 3). The athlete remained non-weight-bearing in the walking boot for 3 weeks. During the initial 7 days after trauma, he was treated with cryotherapy and pulsed ultrasound to assist in limiting the inflammatory response. After this time, thermotherapy via whirlpool was the modality of choice. At 14 days after trauma, he was given permission to resume strength training upper body exercises in no weight-bearing positions.
Oblique x-ray of the foot showing cortical disruption at the lateral aspect of the cuboid with lucency extending into the body of the cuboid (arrows).
Sagittal computed tomography scan through the cuboid bone. There is an incidental finding of an old posterior malleolus fracture.
Repeat x-rays at 25 days after trauma showed evidence of bone callous formation. The athlete was permitted to begin progressive weight-bearing activities and aggressive ankle and foot rehabilitation exercises as tolerated. Exercises included manual resistance and elastic tubing exercises for muscular strengthening, marble pick-ups, and toe-curling exercises by scrunching up a towel. As the patient tolerated progression, proprioceptive exercises included single-leg balance exercises on a foam pad and the Bosu Ball (Bosu). Running was initiated on the mini-trampoline and progressed as tolerated to the playing field. Approximately 35 days after trauma, the athlete was able to run full speed and begin all football-related activity without any ill effects.
The literature shows few cases of traumatic isolated cuboid fractures occurring in sports and, to our knowledge, none are reported specifically in collegiate football. This is especially true as it relates to the nutcracker mechanism causing compression fractures of the cuboid bone. Cuboid compression fractures uniquely occur when the cuboid bone is caught between the bases of the fourth and fifth metatarsal and the anterior surface of the calcaneus during severe forefoot abduction.7 Ceroni et al10 described 4 cases of cuboid fractures occurring in teenaged female equestrian athletes who sustained extreme forefoot abduction with axial loading as their horses fell on top of them with their feet caught in the stirrup, which acted as a fulcrum. Nutcracker cuboid fractures (stress and traumatic) have been described in ballet dancers, likely due to repetitive axial loading of the foot.11
The static and dynamic functions of the foot are influenced by the integrity of the cuboid bone5; therefore, these fractures are concerning for potential serious complications. Operative reconstruction is advised in all cases presenting with bony displacement or articular step-off, which may present with lateral column shortening or articular displacement.12 Isolated nondisplaced fractures are a small proportion of fractures to the cuboid bone. These do not typically require fixation and can be treated conservatively if there are no other concomitant fractures or ligamentous disruption. Long-term sequelae of cuboid fractures are due to: the residual incongruity of intra-articular fractures (particularly of the calcaneocuboid and cubometatarsal joints), shortening of the lateral column, and nonunion.7 These can lead to peroneal tendinopathy, midfoot instability, and early degenerative changes.13 Therefore, continued pain or inability to return to activity needs further evaluation.
Implications for Clinical Practice
Cuboid fractures are uncommon in sports, with isolated cuboid fractures being rare1,8 because they typically occur in combination with other fractures or dislocations about the foot and ankle. Anatomy and function as it relates to the foot biomechanics is important because, once disrupted, they are the main factors that underlie the concern for potential complications. A focused clinical examination and appropriate imaging is key to the appropriate diagnosis guiding management decisions as to the need for surgical or conservative treatment options. Clinical decision rules such as the Ottawa Ankle Rules (OAR) and subsequently the Buffalo Modified OAR can help decrease the use of radiographs in foot and ankle injuries.14 The Buffalo Modified OAR emphasize the need for palpation of the midline of the lateral and medial malleolus to improve the specificity of the OAR. However, in cases where weight-bearing (two steps on the affected leg) is possible in either the initial presentation or in the examination room, sensitivity would be increased by direct palpation of the midtarsal bones individually.
Isolated fractures to the cuboid bone via the nutcracker mechanism are rare in sports, but recognition of these injuries is imperative to avoid long-term complications. The typical injury pattern is due to hyperplantarflexion of the ankle with axial loading of the midfoot on a fixed forefoot. Evaluation must include the assessment for concomitant injury, with particular focus to determine possible disruption of alignment or shortening of the lateral column of the foot. A conservative approach to nondisplaced fractures of the cuboid bone is recommended. Operative reconstruction is advised in cases presenting with bony displacement, articular malalignment, or with lateral column shortening. We have outlined a progressive rehabilitation program that was successful in aiding a return to sports participation.
- Ohmori T, Katsuo S, Sunayama C, et al. A case report of isolated cuboid nutcracker fracture. Case Rep Orthop. 2016;2016:3264172. doi:10.1155/2016/3264172 [CrossRef]
- Court-Brown CM, Zinna S, Ekrol I. Classification and epidemiology of mid-foot fractures. Foot. 2006;16(3):138–141. doi:10.1016/j.foot.2006.03.003 [CrossRef]
- Yu G, Yu T, Yang Y, Li B, Yuan F, Zhou J. Nutcracker fracture of the cuboid: management and results. Acta Orthop Belg. 2012;78(2):216–219. 22696993
- Clements JR, Dijour F, Leong W. Surgical management navicular and cuboid fractures. Clin Podiatr Med Surg. 2018;35(2):145–159. doi:10.1016/j.cpm.2017.12.001 [CrossRef]
- Fenton P, Al-Nammari S, Blundell C, Davies M. The patterns of injury and management of cuboid fractures: a retrospective case series. Bone Joint J. 2016;98-B(7):1003–1008. doi:10.1302/0301-620X.98B7.36639 [CrossRef]
- Hermel MB, Gershon-Cohen J. The nutcracker fracture of the cuboid by indirect violence. Radiology. 1953;60(6):850–854. doi:10.110.1148/60.6.850 [CrossRef]
- Koch J, Rahimi F. Nutcracker fractures of the cuboid. J Foot Surg. 1991;30(4):336–339.
- Miller SR, Handzel C. Isolated cuboid fracture: a rare occurrence. J Am Podiatr Med Assoc. 2001;91(2):85–88. doi:10.7547/87507315-91-2-85 [CrossRef]
- Dodson NB, Dodson EE, Shromoff PJ. Imaging strategies for diagnosing calcaneal and cuboid stress fractures. Clin Podiatr Med Surg. 2008;25(2):183–201. doi:10.1016/j.cpm.2007.12.001 [CrossRef]
- Ceroni D, De Rosa V, De Coulon G, Kaelin A. Cuboid nutcracker fracture due to horseback riding in children: case series and review of the literature. J Pediatr Orthop. 2007;27(5):557–561. doi:10.1097/01.bpb.0000279031.66774.c0 [CrossRef]
- Carsen S, Quinn BJ, Beck E, Southwick H, Micheli LJ. “Nutcracker fracture” in a ballet dancer performing in The Nutcracker. J Dance Med Sci. 2015;19(3):124–127. doi:10.12678/1089-313X.19.3.124 [CrossRef]
- Mihalich RM, Early JS. Management of cuboid crush injuries. Foot Ankle Clin. 2006;11(1):121–126, ix. doi:10.1016/j.fcl.2005.11.001 [CrossRef]
- Borrelli J Jr, De S, VanPelt M. Fracture of the cuboid. J Am Acad Orthop Surg. 2012;20(7):472–477. doi:10.5435/JAAOS-20-07-472 [CrossRef]
- Leddy JJ, Smolinski RJ, Lawrence J, Snyder JL, Priore RL. Prospective evaluation of the Ottawa Ankle Rules in a university sports center: with a modification to increase specificity for identifying malleolar fractures. Am J Sports Med. 1998;26(2):158–165. doi:10.1177/03635465980260020201 [CrossRef]