The heel bone is the most vulnerable tarsal bone, and heel fractures account for 2.6% of all fractures in the body, most of which are intra-articular fractures and are affected by high-energy injuries; intra-articular fractures of the heel bone cannot restore normal anatomy through conservative treatment alone, and often leave sequelae such as traumatic arthritis leading to pain, flat feet, and heel widening, etc. Therefore, most of these fractures are now advocated for incision and internal fixation treatment. This method can achieve both fracture repositioning and reliable fixation of the repositioned fracture block, allowing early functional exercise. From January 2010 to February 2012, 60 cases of intra-articular fractures of the heel were treated by incision and internal fixation with titanium plates, and satisfactory results were achieved.
1. Subjects and methods
1.1 General data of this group 60 cases (63 feet), male 35 cases (38 feet), female 25 cases (25 feet), age 18-57 years, the average age is 35.5 years; left side 31 cases, right side 26 cases, bipedal 3 cases; all are closed fractures of the heel bone. According to Sanders’ staging: 33 feet of type II and 30 feet of type III. Lateral axial radiographs and CT scans of the affected heel bone were performed before surgery. The BÖhler angle 0-20 (10.0±4.5)° combined with spinal fracture was measured preoperatively in 3 cases.
1.2 Surgical method
Epidural anesthesia was used routinely, and general anesthesia was used for combined spinal fractures; a tourniquet was placed on the thigh, and the unilateral position was the healthy side, and the bilateral position was the prone position. The incision was made in the lateral L-shape of the heel bone, with the proximal incision starting longitudinally between the posterior edge of the fibula and the Achilles tendon and turning anteriorly at right angles to the base of the fifth metatarsal at the dorsal and plantar migration of the foot; the skin was incised subcutaneously in full layers to reach the lateral wall of the heel bone, with sharp peeling, no layered peeling, no electric knife, and careful handling of the skin flap peeling.
The skin and subcutaneous tissues are retracted without clamps or hooks, and three to four 2 mm Kristen pins are inserted into the lateral ankle of the fibula, the neck of the talus and the dice bone, respectively. After a comprehensive understanding of the type of fracture and the degree of displacement under direct vision, prying and repositioning was performed, and the subluxated posterior articular surface was pried upward with a periosteal stripper to bring it into alignment with the talar subarticular surface, which was fixed with a kerf pin from the heel bone toward the talus and used as a mold.
The displaced intra-articular fracture block was accurately repositioned, fixed with a Kirschner pin from the heel bone toward the dice bone, and the lateral aspect of the heel bone was extruded to restore the heel height, length, and cross angle of the heel tuberosity joint angle, while attention was paid to repositioning the distal heel dice articular surface of the heel bone without bone grafting in the bone defect area. After the fracture was satisfactorily repositioned, the heel bone splint (made by Jiangsu Genesis Medical Equipment Company, titanium material) was shaped and placed on the lateral wall of the heel bone and fixed with screws, at least one of which was fixed in the talonavicular process of the heel bone. Before closing the wound, a drainage tube is placed in the wound, and a drainage bottle is attached after suturing the wound (2 types of drainage systems: 1. Redon high negative pressure drainage system produced by pfm medical products GmbH, Germany; 2. common negative pressure suction ball used in clinical practice). Suture the wound, dressing pressure dressing 30 minutes after opening negative pressure
2. Results
The postoperative BÖhler angle was measured as 25-40(35.0±3.5)°. The group was followed up for 3 months-16 months; the fracture healing time was 3-6 months. There was no change in heel bone morphology, no loss of Bahler’s angle or height, and no plate screw fracture; postoperative wound healing was delayed in two cases and wound infection occurred in one case, which healed after treatment with negative pressure closed suction and peroneal nerve trophic flap transposition repair. The efficacy was evaluated according to the Maryland score: 40 cases were excellent, 14 cases were good, and 6 cases were acceptable, with an excellent rate of 90%.
3. Discussion
3.1 Timing of surgery
Heel fracture is a high-energy induced injury, and the fracture violence can also lead to soft tissue injury, which is usually more serious. After the injury, the soft tissue swelling is obvious and even the osteofascial compartment syndrome appears. According to Yu et al, the peak of swelling after heel fracture is about 3 days after the injury, and the timing of surgery should be before or after the peak of swelling. In this group of patients, the affected limb was routinely elevated after admission to use mannitol and sodium hesperidin to reduce swelling, and surgery was given when the swelling subsided and the wrinkle test was negative; the operation time was 7-13 days after the injury, with an average of 10 days.
3.2 Preoperative examination
Preoperative orthogonal, lateral and axial radiographs of the heel were routinely taken. Emphasis is placed on the application of CT plain and 3D reconstruction in heel fractures. The application of multilayer spiral CT and high quality multilevel reconstruction techniques is very important to provide morphological information of complex fracture dislocation.CT scan can be performed in three planes: horizontal, sagittal and coronal planes for thin layer plain scan, which can clearly reflect the fracture dislocation of heel talonavicular joint and heel dice joint. The 3D reconstruction technique can visualize the characteristics of the fracture in three dimensions. It provides a basis for preoperative formulation of a thorough and detailed surgical plan, and also allows postoperative evaluation of the fracture to determine the prognosis. In this group of patients, preoperative 3D CT examination was routinely performed.
3.3 Surgical incision and exposure
The lateral L-shaped approach to the heel bone for internal fixation of intra-articular heel fractures has the advantage that the lateral wall of the heel bone can be exposed under direct vision, which is conducive to fracture repositioning and fixation, and the peroneal cutaneous nerve can be exposed and protected during incision; Wu et al. concluded that the lateral incision provides a good surgical view, which can reveal the entire fracture portion of the heel bone and allow anatomical repositioning under direct vision, reducing the incidence of complications. The flap should be cut to the surface of the heel bone in a single incision, and the full-thickness flap should be sharply peeled and exposed, with the flap turned up from under the periosteum to avoid peeling the skin and subcutaneous tissue; the use of an electric knife should be avoided. The “no-touch” technique of flap retraction was used, with gentle movements and no violence; only one case of skin necrosis infection occurred in this group of 60 patients.
3.4 Fracture repositioning and fixation
During the operation, the lateral wall of the heel bone could be pried open to explore the fracture displacement of the anterior, middle and posterior articular surfaces of the heel bone under direct vision, so as to achieve anatomical repositioning of the fracture as far as possible, reconstruct the articular surfaces, restore the heel height, length, heel nodal joint angle (Bohler angle) and heel cross angle (Gissane angle), and pay attention to the repositioning of the distal heel dice articular surface. The posterior articular surface fracture block was temporarily fixed with a kyphotic pin after repositioning. Intraoperative fluoroscopy was performed to check the repositioning and adjust the fracture repositioning if necessary. A heel titanium plate was selected and shaped, placed on the lateral wall of the heel, and screwed in place, with at least 1 of the screws fixed in the talonavicular process of the heel carrier.
3.5 Bone grafting
Most orthopaedic surgeons do not advocate bone grafting because the bone defective part is the osteoporotic area, which does not play a big role in mechanics, but bone grafting affects the recovery of the articular surface, and is prone to complications of bone grafting and increases the chance of infection. The heel bone is mainly cancellous bone, with rich blood circulation and stable mechanics relying on the peripheral “eggshell”-like structure, and the heel bone has a strong regenerative ability, therefore, unless there is a serious defect, bone grafting is not necessary in most cases. Our experience is to avoid bone grafting as much as possible, and if bone grafting is needed, to use autologous iliac bone as much as possible, and to avoid artificial bone and allogeneic bone, because of their high exudation, poor resorbability, high incidence of secondary infection and local skin and soft tissue necrosis.
3.6 Postoperative treatment
3.6.1 Routine treatment: elevate the affected limb, routinely use antibiotics for 3-5 d, dehydration and decongestant drug application; remove the stitches 2 weeks after surgery, and according to the specific situation, the stitches removal time can be extended appropriately.
3.6.2 Pay attention to postoperative drainage: 30 cases in this group used Redon high negative pressure drainage system with vacuum design, and the negative pressure in the drainage bottle could reach 98 kPa, and 30 cases used ordinary negative pressure suction ball with non-vacuum design, which could provide low negative pressure of 10-2 OKPa. As a result, one case of wound infection and two cases of delayed wound healing occurred in the normal negative pressure group, while no l case of infection and delayed healing procedure occurred in the high negative pressure group. And it has been shown [7, 8] that continuous high negative pressure drainage can make the layers of the wound wall closely adhere to form intra-tissue fixation, improve microcirculation, enhance local blood supply, improve the proliferation of cells in the tissue as well as promote the growth of granulation tissue, and accelerate the healing of the wound; our experience is that adequate drainage, which is conducive to reducing postoperative swelling, is conducive to reducing the incidence of wound infection and delayed healing.
3.6.3 Functional exercise After the operation, we can perform isometric muscle stretching functional exercise; after the pain is relieved 2-3 days after the operation, we can perform active and passive ankle flexion and extension exercise; after the fracture is healed 3 months after the operation, we can gradually walk with weight.
Our experience: choosing the proper timing of surgery, fine intraoperative operation, and good postoperative management, titanium plate internal fixation is an effective method to treat intra-articular fractures of the heel bone.