The Treatment of Complex Motorcycle Spoke Injuries in Children. A Report of Four Cases and Literature Review

Abstract

Motorcycle spoke injuries involving the soft tissue, Achilles tendon, and calcaneal defects are rare in children. Currently, calcaneal defects are very challenging to treat. Multiple methods have been used in clinical practice; however, an effective treatment has yet to be established, especially when Achilles tendon and soft-tissue defects are also present. It is important to address this condition, because the calcaneus plays a key role in standing and gait. Unsatisfactory treatment of calcaneal defects may significantly decrease patients’ quality of life (eg, by limiting mobility). In this article, we report the effective treatment of calcaneal defects in four children using distraction osteogenesis with an external fixator framework designed by the authors. From May 2014 to May 2015, four children (age range, 6–11 years) with defects of the Achilles tendon, soft tissue, and calcaneus resulting from a motorcycle accident were treated at our hospital. The Achilles tendon and soft-tissue defects were treated with second-stage reconstruction. In the third-stage surgery, osteotomy of the residual calcaneus was performed. A customized external fixator was used to lengthen the calcaneus at a rate of 1.5 mm/day in the posterior direction and reposition it by 40° in the inferior direction. In all four children, the calcaneus was lengthened by 5 cm. Distraction osteogenesis through external fixation is effective for restoring the length, width, and height of the calcaneus in children.

The mechanisms of motorcycle spoke injuries to the heel have some unique features.[1] A grading system was developed for these injuries according to the tissues involved.[2] Based on the grading system, motorcycle spoke injuries of the heel are divided into four grades. In grade I, there is a heel skin defect exposing the Achilles tendon. In grade II, there is a skin defect, and the Achilles tendon is ruptured and defective. In grade III, there is a skin defect, the Achilles tendon is ruptured or partially lost, and the calcaneus is fractured or partially lost. In grade IV, the heel is mangled. The grade III type or complex motorcycle spoke injury is a unique trauma. It includes not only injury to overlying soft tissue and Achilles tendon rupture/loss but also posterior calcaneal loss, including the absence of the tubercle, which is challenging to treat clinically. There has been no literature report on reconstruction of a partially lost calcaneus. Surgery protocols consist primarily of flap transfers, Achilles tendon reconstruction, and calcaneus management. Achilles tendon and calcaneal defects are rarely reported in children. Achilles tendon defects and soft-tissue defects are usually managed with emergent wound care and second-stage reconstruction.[2] Injury to the Achilles tendon, soft tissue, and calcaneus is devastating to foot function and thus patient quality of life, especially in active children. Currently, there is no effective method for the treatment of calcaneal defects.[2]

Distraction osteogenesis is a well-established technique that has been successfully used in the treatment of old calcaneal fractures, complex foot deformities, and calcaneal osteomyelitis.[2] We designed an external fixator framework for distraction osteogenesis for the treatment of calcaneal defects. In this article, we report our initial outcomes in four children with Achilles tendon defects with soft-tissue and calcaneal defects using this method for treatment of complex motorcycle spoke injuries.

Case Report

From May 2014 to May 2015, four children (age range, 6–11 years) sustained Achilles tendon, soft-tissue, and calcaneal defects and were treated at our hospital. All four patients were injured by spokes while riding at high-speed on a rear motorcycle seat. According to the grading system, the injuries in these four children were grade III. Wounds were emergently debrided and treated with negative-pressure wound therapy in the first-stage surgery. Three days later, the Achilles tendon was reconstructed in the second-stage surgery. The tendon space structure, which is defined as the gap across the missing part of the Achilles tendon, was formed by suturing or bypassing the proximal end of the Achilles tendon to the residual end of the calcaneus bone as a bridge using dissolvable sutures. The Achilles tendon was sutured onto the remnant calcaneus using a previously described surgical method.[3] A pedicled flap was transferred to cover the wound. The third-stage surgery was performed 1 month later to restore the shape of the calcaneus using distraction osteogenesis through an Ilizarov external fixator framework designed by the authors.

The calcaneal defect was evaluated preoperatively using plain radiography and three-dimensional computed tomographic reconstruction (Fig. 1). The patient was placed in the supine position, and general anesthesia was induced. The affected lower limb was raised by 30°. A 4-cm lateral incision was carried out. Through this incision, the plantar fascia was severed (Fig. 2). Because the residual calcaneus was small, it must be close to sideways to have a sufficiently large bone piece to cut and obtain a posterior segment for transplantation. If the osteotomy is too close to the horizontal bone, the posterior inferior segment tends to closely integrate or combine with the plantar fascia. An osteotomy of the calcaneus was performed through a line 1 cm distal from the groove of the fibularis longus tendon and the fibularis brevis tendon. Three olive wires were inserted through the distal part of the calcaneus in the lateral to medial direction (Fig. 3). Another four olive wires were inserted through the proximal part of the residual calcaneus in the lateral to medial direction.

Figure 1. Grade III motorcycle spoke injury of the right foot.

Figure 1. Grade III motorcycle spoke injury of the right foot.

Figure 2. Preoperative evaluation showing the calcaneal defect with absence of the epiphysis in a 7-year-old boy. A, Plain radiograph of the calcaneus on the healthy side. B, Plain radiograph of the calcaneus on the injured side. C, Three-dimensional computed tomographic image of the calcaneus on the healthy side. D, Three-dimensional computed tomographic image of the calcaneus on the injured side.

Figure 2. Preoperative evaluation showing the calcaneal defect with absence of the epiphysis in a 7-year-old boy. A, Plain radiograph of the calcaneus on the healthy side. B, Plain radiograph of the calcaneus on the injured side. C, Three-dimensional computed tomographic image of the calcaneus on the healthy side. D, Three-dimensional computed tomographic image of the calcaneus on the injured side.

Figure 3. Right side of the foot with grade III motorcycle spoke injury. The one-stage tensile stress surgical suture technique with the yurt bone surgical technique without orthosis was used.

Figure 3. Right side of the foot with grade III motorcycle spoke injury. The one-stage tensile stress surgical suture technique with the yurt bone surgical technique without orthosis was used.

Caution was used to avoid injury to the gastrocnemius nerve, peroneus brevis tendon, and peroneus longus tendon (Fig. 4). Then, the author-designed external fixator was installed (Fig. 5). The frame consisted of two half-rings fixed around the tibia using olive wires and two half-rings fixed around the foot using olive wires. The olive wires through the calcaneus were connected with the fixator. The posterior segment of the calcaneus was distracted 5 mm and 40° posteroinferiorly. Then, the incision was sutured (Fig. 5). Beginning on postoperative day 10, distraction osteogenesis of the calcaneus was performed at a rate of 0.75 to 1.0 mm two times per day. The calcaneus was lengthened until its length was 2 cm longer than the contralateral side, because of concern regarding skeletal maturity, considering that the healthy side would grow more quickly.

Figure 4. The surgical approach, positioning, osteotomy, and installation of the external fixator framework used for distraction osteogenesis of the calcaneus in a 7-year-old boy. A, The surgical approach. B, Wire positioning in the calcaneal osteotomy site. C, Placement of a metal nut in the calcaneal osteotomy site to support radiographic examination of bone gaps. D, Radiographic image of the final external fixator construct after the osteotomy.

Figure 4. The surgical approach, positioning, osteotomy, and installation of the external fixator framework used for distraction osteogenesis of the calcaneus in a 7-year-old boy. A, The surgical approach. B, Wire positioning in the calcaneal osteotomy site. C, Placement of a metal nut in the calcaneal osteotomy site to support radiographic examination of bone gaps. D, Radiographic image of the final external fixator construct after the osteotomy.

Figure 5. An overview of the external fixator framework and installation of the external fixator (setting the framework onto the leg, front foot, and calcaneus) used for distraction osteogenesis of the calcaneus in a 7-year-old boy. Anteroposterior (A) and lateral (B) views of the external fixator framework. Medial (C), lateral (D), anteroposterior (E), and plantar (F) views of the applied external fixator framework.

Figure 5. An overview of the external fixator framework and installation of the external fixator (setting the framework onto the leg, front foot, and calcaneus) used for distraction osteogenesis of the calcaneus in a 7-year-old boy. Anteroposterior (A) and lateral (B) views of the external fixator framework. Medial (C), lateral (D), anteroposterior (E), and plantar (F) views of the applied external fixator framework.

The calcaneus was lengthened by a mean of 5 cm in the four patients. The length, width, and height of the calcaneus were restored (Fig. 6). After removal of the external fixator, the patient achieved full weight-bearing ambulation without support by 8 weeks. Three-dimensional computed tomographic imaging of the defect side showed fast overall regeneration of the Achilles tendon (Fig. 7). No tendon elongation was observed. Comparison of the shape between the healthy side and the ruptured side in a 7-year-old boy at 18 weeks postoperatively showed appropriate recovery of the shape of the affected heel (Fig. 8).

Figure 6. Plain radiographic and three-dimensional computed tomographic images of the calcaneus on the injured side at postoperative week 18. (A) Plain radiograph of the calcaneus on the injured side. (B) Three-dimensional computed tomographic image of the injured calcaneus.

Figure 6. Plain radiographic and three-dimensional computed tomographic images of the calcaneus on the injured side at postoperative week 18. (A) Plain radiograph of the calcaneus on the injured side. (B) Three-dimensional computed tomographic image of the injured calcaneus.

Figure 7. Three-dimensional computed tomographic image of bilateral calcanei in a 7-year-old boy at postoperative week 18. (A) The Achilles tendon and calcaneus on the uninjured side. (B) Image of the Achilles tendon and calcaneus on the operative side revealing attachment and span of tendon.

Figure 7. Three-dimensional computed tomographic image of bilateral calcanei in a 7-year-old boy at postoperative week 18. (A) The Achilles tendon and calcaneus on the uninjured side. (B) Image of the Achilles tendon and calcaneus on the operative side revealing attachment and span of tendon.

Figure 8. Clinical comparison of the operative versus nonoperative limbs at postoperative week 18 in a 7-year-old boy, showing that an acceptable heel contour had been achieved. (A) Lateral clinical views of the bilateral extremities. (B) Medial clinical views of the bilateral extremities.

Figure 8. Clinical comparison of the operative versus nonoperative limbs at postoperative week 18 in a 7-year-old boy, showing that an acceptable heel contour had been achieved. (A) Lateral clinical views of the bilateral extremities. (B) Medial clinical views of the bilateral extremities.

The Achilles tendon Total Rupture Score (ATRS) is a patient-reported instrument with high reliability, validity, and sensitivity for measuring outcomes after treatment in patients with a total Achilles tendon rupture.[4] Each question of the ATRS was answered by the patients, with a score ranging from 0 to 10 (where 10 is best). The mean ATRS was 7.9 at postoperative week 8, increased to 10 at week 18, and plateaued at week 24 (Table 1). At postoperative week 18, the four patients were able to perform sustained or uninterrupted tiptoe stepping for 60 seconds and a single-leg heel raise of 4.0 to 6.0 cm for 60 seconds (Fig. 9 and Fig. 10).

Table 1. Achilles Tendon Rupture Scores (n = 4).

Table 1. Achilles Tendon Rupture Scores (n = 4).

Figure 9. The patient was able to perform a sustained 5.0-cm single-leg heel rise for 60 seconds at postoperative week 18.

Figure 9. The patient was able to perform a sustained 5.0-cm single-leg heel rise for 60 seconds at postoperative week 18.

Figure 10. One patient was able to perform a sustained single-leg heel rise of more than 10 cm.

Figure 10. One patient was able to perform a sustained single-leg heel rise of more than 10 cm.

Discussion

Complex motorcycle spoke injuries, especially with calcaneal defects, remain a clinical challenge. Because of the critical roles of the calcaneus in standing and gait, lack of treatment or unsatisfactory treatment of calcaneal defects can lead to a significant decrease in the patient’s quality of life. The goal of reconstructing calcaneal defects is to restore foot function and patient activity. When considering calcaneal defect procedures, it is important that the final reconstruction is free from contractures, open lesions, atrophy, and edema. If these conditions occur even after reconstruction, foot amputation or subtotal amputation of the ankle would be necessary.

Various methods have been attempted to reconstruct calcaneal defects. Lykoudis et al reported a case of reconstructing a complex calcaneal defect using a free fibula–flexor hallucis longus osteomuscular flap.[5] The patient achieved full weightbearing at 6 months postoperatively. However, this method is associated with donor-site morbidity, which might be a contraindication in some patients. Similarly, vascularized medial femoral condyle flaps and free fibular osteocutaneous flaps have been used to reconstruct calcaneal defects.[6]

Conclusions

In comparison to reconstruction of soft tissue, Achilles tendon, and calcaneal defects using osteomuscular or osteocutaneous flaps, distraction osteogenesis for the treatment of calcaneal defects associated with complex motorcycle spoke injuries is free of donor-site morbidity. This technique has been previously used to successfully restore the mass of the tubular bones after radical debridement for osteomyelitis. In our case, the distraction was performed at a rate of 0.75 to 1.0 mm two times per day. The bone healing was very fast in all four cases. After removal of the external fixator, the patients achieved full weightbearing ambulation without support by 5 to 8 weeks. The American Orthopaedic Foot and Ankle Society scale scores were 70 at 8 weeks, 84 at 18 weeks, and 100 at 2 years (Table 2). Of note, our patients were young children with ages ranging from 6 to 11 years; thus, future distraction osteogenesis might be considered to accommodate their increasing activity and body weight for follow-up treatment of complex motorcycle spoke injuries. In fact, long-term follow-up is necessary because of the complexity of these motorcycle spoke injuries.

Table 2. American Orthopaedic Foot and Ankle Society Scale ^a.

Table 2. American Orthopaedic Foot and Ankle Society Scale ^a.