Heel pad injuries, although uncommon, pose a difficult challenge because of the unique and complex nature of the fat pad structure. The tight honeycomb arrangement of elastic fibrous septa enclosing closely packed fat cells has evolved in order to accept very high loading stresses during gait. This specialized anatomy renders the heel tissue irreplaceable in the event of serious injury.
Partial or complete degloving of the heel pad can occur, often as a result of road accidents. It may be associated with a skeletal injury or polytrauma1. Complete or subtotal avulsions of the heel pad, or those with extensive neurovascular damage, will need replantation with use of microvascular surgical techniques2,3 or reconstruction with soft-tissue flaps1,4,5.
In situations of partial avulsion, when the sensation is intact and the heel pad is viable, it may be possible to debride and reattach the flap. Simple suturing to reattach the heel edges may not be secure enough, or it can lead to increased wound pressure, resulting in wound breakdown, infection, and flap necrosis6. This report describes a technique with use of multiple Kirschner wires (K-wires) to reattach a partial heel pad avulsion without the use of sutures in four patients. To our knowledge, this is the first report of this method of anchoring the partially avulsed heel pad with successful outcomes. All four patients were informed that data concerning their cases would be submitted for publication, and they all provided consent.
Following initial assessment and resuscitation of the patient according to the Advanced Trauma Life Support protocols, acutely presenting partial heel pad avulsion injuries are assessed for the extent of the degloving, wound contamination, soft-tissue loss, skeletal injury, and sensation and viability of the degloved flap. The patient is counseled about the potential complications of replantation and the possible necessity for additional surgical procedures, including amputation. Radiographs are obtained to identify any skeletal injury. A third-generation cephalosporin antibiotic, along with sulbactam, is administered intravenously preoperatively.
Under a general or regional anesthetic, the wound is reassessed without the use of a tourniquet. Thorough debridement and copious wound lavage are performed. The heel pad is securely anchored to the calcaneus with multiple 1.8-mm K-wires. The first few K-wires are inserted with an aim to grossly secure the avulsed flap in the correct anatomical position. Additional wires are then inserted as required to ensure that the flap is secured in a stable fashion to the underlying bone. The distance between the wires should be approximately 2 cm. In order to prevent the development of wound tension, we attempt to not place any wires close to the skin wound edge. Furthermore, in order to minimize wound tension, the skin wound is not sutured.
A light compressive dressing is then applied, and the foot is protected in a plaster splint. An oral antibiotic combination of a third-generation cephalosporin and clavulanic acid is administered for one week.
The patient is allowed toe-touch weight-bearing with the use of walking supports. Regular normal saline dressings are used to aid wound healing by secondary intention. The K-wires are removed after four weeks in an outpatient procedure, and the patient is permitted to progress to full weight-bearing as tolerated by eight weeks. Wound and flap healing is assessed weekly, and the patient is discharged when no additional problems are anticipated.
A summary of the four patients treated with our technique is presented in Table I.
Case 1. A fifty-three-year-old man fell approximately six feet and sustained a partial right heel pad avulsion and an ipsilateral distal radius fracture. The avulsed segment was deemed salvageable, and the patient underwent debridement and multiple K-wire fixation. The avulsed flap healed without any complications, and the patient was able to return to heavy work as a farmer after three months.
Case 2. A fifty-six-year-old man sustained a partial heel pad avulsion when a heavy rock landed obliquely on the right heel. No other injuries or any fractures were identified. The sensate, vascular heel flap was secured to the calcaneus with multiple K-wires. Full weight-bearing was possible at three months; at the eighteen-month follow-up, the patient was walking without pain.
Case 3. A thirty-five-year-old woman sustained an isolated partial right heel pad avulsion as a result of a fall from a motorbike (Figs. 1 through 4). The avulsed segment had good sensation and vascularity. Another laceration was present over the heel in the region of the Achilles tendon insertion. At the time of wound debridement, a lateral cortical break was identified in the calcaneus, which was not visualized on the initial radiographs. Apart from slight delayed healing of the island of skin between the two lacerations, the patient made an uncomplicated recovery. She was able to bear weight fully at eight weeks after the injury.
Case 4. A forty-six-year-old woman was run over by a three-wheeled motor vehicle, resulting in a right heel pad avulsion with exposure of the distal Achilles tendon. Radiographs revealed lateral cortical disruption of the calcaneus. After debridement and K-wire fixation of the avulsed heel pad, a few skin sutures were used to cover the exposed Achilles tendon. There was mild necrosis of the posterosuperior edge that eventually healed. At the four-month follow-up, the heel pad was viable with intact sensation, and the patient had no pain and was walking without the use of any walking aids.
Degloving of the heel pad is most commonly caused by a crush injury7. The separation of the flap usually occurs in a posterior-to-anterior direction. Blunt tangential forces disrupt the soft tissues in the medial, posterior, and lateral areas of the heel, leaving a soft-tissue bridge anteriorly7.
Because of the unique load-bearing function of the heel pad and its complex architecture, every attempt should be made to retain the original tissues in cases of partial degloving of the heel with intact vascularity. Attempts to substitute the heel pad with vascularized or regional flaps are not without complications5-7, and problems with fine sensations in the sole, retained soft-tissue bulk, tissue breakdown, and altered physiological pressure distribution during gait have all been reported.
Our technique involves thorough debridement followed by anchorage of the avulsed heel pad to the bone with percutaneous K-wires. This method ensures stable reattachment of the potentially viable heel tissue with the least amount of possible trauma to the flap. The skin edges are not sutured in order to facilitate drainage and prevent buildup of fluid pressure under the flap.
Cichowitz et al. have shown that the blood supply to the heel arises posteriorly from the medial calcaneal branch of the posterior tibial artery along with a minor contribution from the lateral calcaneal branch of the peroneal artery8, and the anterior part is supplied primarily by the lateral plantar artery. However, there are rich vascular anastomoses among these vessels at a subdermal and periosteal level in the heel. The vessels travel within the fibrous septa that anchor the skin of the heel to the periosteum of the calcaneus. As a result, it may be that simple stable reattachment of the avulsed heel pad, as described with our technique, is sufficient to enable survival of the heel flap. We believe that the use of K-wires provides a simple and effective technique to salvage partial avulsion of the heel pad without requiring a complicated microsurgical procedure.