Performing emergency surgery as early as possible is a major way to avoid soft tissue necrosis and/or improve soft tissue condition.
Beavis et al. 14 subdivided calcaneal avulsion fractures into three different types, i.e., "sleeve" fracture, conventional "beak" fracture, and infrabursal fracture at the middle third of posterior tuberosity 14. Displaced posterior calcaneal tubercle fracture, especially the abovementioned second type ("beak" fracture), can easily result in local skin and soft tissue pressure necrosis and in ulcers 15. Furthermore, fracture blisters and deep abrasions affect clinical treatment in making decisions, by which the good opportunity of in-time surgery may be delayed. It has been reported that delayed fracture treatment can cause severe skin complications 8,11,14,16. When the fracture displacement exhibits local bony bulge, emergency surgery must be performed as soon as possible. In this study, eleven of the fifteen patients underwent emergency surgery, the interval between injury and emergency surgery in patients who admitted to the hospital was a minimum of 8 hours and a maximum of 15 hours, with the average time of 9.67 hours. All of them were accompanied by closed soft tissue injuries of different degrees. According to AO soft tissue classification, five cases were IC-2, six cases were IC-3, and four cases were IC-4. However, it must be emphasized that if patients cannot receive in-time emergency surgery due to objective reasons, plaster fixation in plantar flexion on the front of lower leg must be used first to avoid soft tissue irritation. In addition, it has been generally acknowledged that if non-surgical treatment for avulsion fracture of calcaneal tuberosity does not achieve its expected clinical effect, an alternative of open reduction and internal fixation is strongly recommended 10. When surgical conditions can be guaranteed, the surgery shall be performed immediately.
Strong fixation reduces recovery time while preventing internal fixation from failure.
There are various studies on choosing the optimal internal fixation for performing surgery 10. Avulsion fracture of calcaneal tuberosity has been treated with diverse approaches such as screw fixation, suture anchor fixation, and tension band wiring 14,17. Squires et al. recommended the use of steel wire and tension bands for fixation 10. Yoshida et al. reported that lag screws can be adopted to fix calcaneal tuberosity avulsion fracture 18. However, complications were often reported, which included avulsed fragment displacement, wound dehiscence, and skin irritation 8,14,16. With respect to the patients with small fractures, they were treated with screw fixation. Unfortunately, the article reported one case of failure of the internal fixation using screws 11. As for the patients with large fragments, particularly for those with the fracture line extending to subtalar joint, some researchers adopted conventional lateral calcaneal plate with larger incision 11. The utilization of cannulated cancellous screws and titanium wire not only provided strong internal fixation without any skin or incision problems that may be caused by previous methodologies, but enabled earlier postoperative recovery with range of motion and weight-bearing exercises 19. However, the above approach conducted a posterior Achilles tendon vertical midline curved incision and a small lateral plantar incision, which undoubtedly increased the wound area. In order to treat a case of chronic "beak fracture", Laxman Rijal 2 performed Z-plasty of Achilles tendon, through which the proximal stump of Achilles tendon was reinforced by non-absorbable polyester suture with a 4.5 mm cancellous screw placed transversely in calcaneus. Specifically, the reinforcement sutures were positioned to secure the tendon lengthening. Fragments were fixed with 4.5-mm cancellous cannulated screws and washers. Before allowing the patient to gradually begin weight bearing, the reinforcement sutures were percutaneously removed under local anesthesia on an outpatient basis 2. Ramanujam CL 20 reported that through using Steinmann pins and Ilizarov external fixation, significant traumatic calcaneal avulsion fractures with concomitant Achilles tendon ruptures can be successfully reduced. Nevertheless, it must be noted that this technique still has one disadvantageous effect of cutting a second plantar incision, which may potentially cause skin necrosis or irritation 20. Agni et al. applied locking compression hook plate (LCP) to treat avulsion fracture of calcaneal tuberosity 21. They further discovered that this approach can also offer stable fixation, however, the LCP hook plate is comparatively expensive. Ernst et al. adopted "hurricane strap" technique (An A.L.P.S dorsal midfoot fusion plate is bent into an L shape with a traditional longer "L" incision for fixation) to fix tongue-type calcaneal fracture 22. Ding et al. introduced a new technique for successfully treating calcaneal tuberosity fracture using a fixation of 180-degree microplate 6. However, this research paper is only a case report and provides with limited theoretical foundation.
In contrast to the abovementioned treatment and fixation, the incision involved in our proposal is not performed at the heel or on the sole of the foot. Instead, we choose an improved and shorter "L-shape" incision on the median line of posterior edge of Achilles tendon and fibula. The incision is kept a certain distance away from the injured skin surface to prevent the soft tissue from being irritated by the displaced fracture fragment at the heel. Through performing the above approach, no necrosis of skin or soft tissues are observed in our results. Specifically, our proposed method adopts a one-fourth tubular plate, which is not so expensive compared with locking plates. During the operation, the plate is preformed to customize it hook-shaped, thereby increasing the holding force of the plate on the fragment. One to two screws can be mounted into the hook at the fragment for compression fixation. Apart from the pressure generated by the screws, the plate can offer pressure on the entire surface of the fracture through the hook. In addition, the eccentric screw can be inserted in the lateral wall of the calcaneus to make the hook fit better with the fracture. Inserting several screws in the lateral wall of the calcaneus better fixes the plate while increasing the stability of the fracture fragment, thereby avoiding internal fixation failure. Lots of patients involved in this study have realized early postoperative functional exercises.