Correspondence Address: Hani El-Mowafi Department of Orthopaedic, Faculty of Medicine, Mansoura University Hospital, 35516 Mansoura Egypt
Source of Support: None, Conflict of Interest: None
Background: Treatment of displaced intra-articular calcaneal fractures (DIACFs) is still controversial. Aim: The objective of our study was to assess the capability of using Ilizarov frame as a minimally invasive technique to improve foot function and restore calcaneal length, height, width, and Bohler's angle in patients with DIACFs. Patients and Methods: We retrospectively reviewed forty patients (mean age, 25.4 ± 9.6 years, a mean follow-up of 44.9 ± 6.9 months) with 48 closed DIACFs who underwent indirect reduction and external fixation using Ilizarov technique. We applied distraction technique through the mechanical axis of the leg and through the foot axis. The drop wire technique was used to restore depressed subtalar fragments. Bone graft was not used. Results: We achieved good alignment in all cases except four feet who had varus deformity. The mean American Orthopaedic Foot and Ankle Society score was 84.6 ± 5. Superficial pin tract infection occurred in 7 feet. Skin pressure necrosis was seen in 3 feet. Statistically, all radiological measures were improved and significantly different from those measured preoperatively. Conclusion: Closed reduction of DIACFs using Ilizarov frame provides a good functional foot outcome with a low risk of postoperative complications. It also has the capability of restoring normal anatomy of the calcaneus.
How to cite this article: El-Mowafi H, Abulsaad MS, Abd-el-naby WL, Kandil YR. Closed reduction of displaced intra-articular calcaneal fractures using ilizarov frame. J Limb Lengthen Reconstr 2017;3:57-64
How to cite this URL: El-Mowafi H, Abulsaad MS, Abd-el-naby WL, Kandil YR. Closed reduction of displaced intra-articular calcaneal fractures using ilizarov frame. J Limb Lengthen Reconstr [serial online] 2017 [cited 2022 May 24];3:57-64. Available from: https://www.jlimblengthrecon.org/text.asp?2017/3/1/57/202215
There is a lack of consensus regarding optimal treatment of displaced intra-articular calcaneal fractures (DIACFs).,, The reported complications of conservative management support the selection of open reduction and internal fixation (ORIF) as the treatment of choice for virtually all displaced calcaneal fractures.,,,, The ideal goals of ORIF include reduction of the articular surfaces of the subtalar and calcaneocuboid joints, restoration of the calcaneal width, height, and length, and correction of varus and lateral translation.,, Recreation of the calcaneal anatomy and joint congruency will restore the normal foot and ankle kinematics. However, deep infection, skin necrosis, peroneal tendonitis, and screw penetration into the subtalar articular surface arising from ORIF will affect the final results. Furthermore, open reduction of comminuted calcaneal fracture is technically difficult and does not necessarily guarantee the anatomic restoration or maintenance of the subtalar joint and calcaneal shape.,,
Several authors have consequently developed minimally invasive or percutaneous techniques for the treatment of intra-articular calcaneal fractures,,, and number of reports have described the use of external fixators to treat such fractures.,,,,,,, Paley and Fischgrund  described open reduction and circular external fixation of intra-articular calcaneal fractures whereas Besch  described closed reduction and use of a hinged external fixator. Emara and Allam  and McGarvey  described techniques using indirect reduction and Ilizarov external fixators. Although these reports have described external fixation as being associated with favorable outcomes, the approaches used have various limitations including technical difficulty, increased operating time, and extensive use of K wires, which may increase the risk of pin tract infection and problematic reduction of the posterior facet.,,,
We conducted this study to find whether the Ilizarov technique could improve foot function and restore calcaneal anatomy (calcaneal length, height, width, and Bohler's angle) if used as a minimally invasive technique without surgical wound for closed reduction of DIACFs.
Patients and Methods
The ethical Committee approval was obtained for this study. A series of forty patients (mean age 25.4 ± 9.6 years; range: 19–65 years) with 48 closed DIACFs were included in this study [Table 1]. Thirty-two patients had unilateral fractures, and eight cases had bilateral fractures. All the patients were treated with indirect reduction and external fixation using Ilizarov technique in the period from June 2009 to August 2011. During the study, this was the only technique used for all the cases of DIACFs who fit into the inclusion criteria. Other methods of treatment were used for patients with calcaneal fractures not fitting the inclusion criteria. Patients included were adult patients who had closed DIACFs. Exclusion criteria included (1) age <18 years, (2) polytraumatized patients, (3) open calcaneal fractures, and (4) patients who were lost to follow-up in our institution before removal of Ilizarov frame. Based on these criteria, sixteen patients were excluded from our analysis: seven were polytraumatized patients, three had open fractures, five were lost to follow-up, and one had inadequate medical records.
Table 1: Preoperative and postoperative patients data
Standard anteroposterior, lateral, and axial plain radiographs of the feet were obtained. The length, height, and Bohler's angle of the calcaneus [Figure 1] as well as the width [Figure 2] were measured preoperatively and at the last follow-up. Bohler's angle was measured using the highest points of the calcaneal tuberosity, subtalar joint, and anterior process. The angle lies at the intersection of two lines: the first connecting the highest point of calcaneal tuberosity to the highest point of subtalar joint and the second connecting the highest point of subtalar joint to the highest point of anterior calcaneal process. The length of the calcaneus (distance L) was measured on the lateral view from the most posterior point of the tuberosity to the center of calcaneocuboid joint. The center of calcaneocuboid joint was measured as the center point of a vertical line drawn parallel to the calcaneal cuboid joint, from the most superior and inferior points on the anterior calcaneus. The height of the calcaneus (distance H) was also measured on the lateral view by a line perpendicular on the calcaneal axis to the highest point of the posterior facet. The calcaneal axis was drawn from the most inferior point of the calcaneal tuberosity to the most distal and inferior part of the calcaneus along the calcaneocuboid joint. The width of the calcaneus (distance W) was measured on the axial view as the length of a perpendicular line connecting two parallel lines drawn tangent to the widest part of the calcaneal tuberosity. Computed tomography (CT) scans of fracture calcaneus in both axial and coronal planes were also obtained.
Figure 1: Lateral X-ray showing radiographic measurement of. B: Bohler's angle, H: Height of calcaneus, L: Length of calcaneus
Results were assessed both clinically and radiologically. We used the clinical rating system of the American Orthopaedic Foot and Ankle Society (AOFAS) scores  for evaluation of functional results. The range of motion of the subtalar joint was measured by placing the patient prone, and then passive inversion and eversion of the heel was done while measuring the extent of motion with a goniometer following the movement of the calcaneal tuberosity relative to the axis of the leg.
At the last follow-up, radiological measurements of the fractured feet (48 feet) were compared with normal measurements of noninjured feet (32 feet) in unilateral cases.
Under spinal anesthesia, the patient was placed on the operating table in supine position with elevation the affected extremity above the contralateral limb using sterile drapes. The foot was positioned to hang out about 6–9 cm over edge of table. No tourniquet was used. The tibial part of the frame was applied as the first step. It consisted of two rings and fixed following the principle of the Ilizarov technique. Then, three wires were inserted: the first in the posterior fragment of the calcaneus, the second wire in the metatarsals bones of the foot, and the third wire was inserted in the neck of the talus. The calcaneal wire was held by 5/8 ring around the hindfoot, and the metatarsal wire was held by 5/8 ring. Both 5/8 rings were connected by threaded rods in both sides of the foot. The calcaneal 5/8 ring was connected to the tibial part by two threaded rods. The two threaded rods attaching the tibial frame to the calcaneal 5/8 ring were placed in posteromedial and posterolateral positions making sure that both keep exactly the same distance between the tibial and calcaneal frames. This was done basically to ensure that the alignment of both rings will ensure elimination of any degree of varus alignment or lateral displacement of the calcaneus. The talus wire was connected to the tibial frame to make sure that distraction will be on the subtalar joint only without applying distraction on the ankle joint [Figure 3].
Figure 3: Schematic drawing showing the frame after reconstruction
To restore calcaneal height, distraction was applied between the tibial part of the frame and the foot part through threaded rods [Figure 4]. The process of downward distraction was done simultaneously from both threaded rods to ensure keeping equal distances between the tibial frame and calcaneal 5/8 ring [Video 1] is available on the website www.jlimblengthrecon.org]. This was done to restore calcaneal height as well as to correct any varus position or lateral displacement of the calcaneus. The restoration of height and correct alignment of calcaneus were checked by fluoroscopic lateral and calcaneal views. If there was any residual malalignment or reduced height, the distraction was adjusted accordingly. After that, distraction was started between the calcaneal 5/8 ring and metatarsal 5/8 ring by the threaded rods to restore calcaneal length [Figure 5] and Video 1]. The subtalar joint and calcaneocuboid joint were checked by fluoroscopy. Under fluoroscopy, Schanz pin with a diameter of 6 mm was inserted in the superior surface of the calcaneus midway between the tip of the posterior articular surface of the talus and the superior tip of the calcaneus tuberosity. The pin was directed parallel to the subtalar joint and toward the displaced fragment of the posterior facet [Video 1]. The position of the pin was checked by fluoroscopy and reduction of the displaced fragment was done by manipulating the pin until satisfactory reduction of the posterior subtalar surface of the calcaneus was achieved [Figure 6]. This joystick technique resulted in skin pressure necrosis at posterior aspect of the heel in three feet when the pin was introduced without a surgical wound; hence, we did small longitudinal incision about 1 cm for applying the joystick technique using the Schanz pin in the rest of cases to avoid the skin necrosis.
Figure 4: Schematic drawing showing the direction of distraction along the long axis of the body
If preoperative CT scan showed depressed and separated subtalar fragments, a drop wire technique was used by inserting a wire into the fragment and connecting it to the calcaneal ring using multiple holes plates. This was done to restore the fragment instead of open reduction through minimal skin incisions. Surgeries were performed without the use of bone graft.
Postoperatively, pin care instruction (using normal saline solution three times a day) was advised. Follow-up lateral and axial calcaneal X-rays were done at 4, 8, and 12 weeks then yearly till the last follow-up [Figure 7]. Patients were encouraged to partially bear weight as tolerated at the 4th week. Under short-acting general anesthesia, the fixator was removed when the patient shows adequate bone formation, which usually occurs between 8 and 12 weeks. The mean timing for removal of the frame was 10.5 ± 2.3 weeks; complete weight-bearing and gait exercises were allowed [Figure 8]a and b].
Data were analyzed using SPSS (Statistical Package for Social Sciences) version 16.0 produced by SPSS Inc. Released 2007. SPSS for Windows, Chicago, Illinois, USA. Qualitative variables were presented as numbers and percentages. Normal distribution of data was assessed using Shapiro–Wilk test. Quantitative variables were presented as mean ± standard deviation and analyzed using paired sample t-test. The level of significance was set at P < 0.05.
There were 31 men (77.5%) and 9 women (22.5%). Thirty-four patients (82.5%) sustained fractures as a result of a fall from height while six patients (17.5%) were involved in motor vehicle accidents. The mean follow-up was 44.9 ± 6.9 months after removal of external fixator (range from 39 to 61 months).
According to Sanders classification, there were 14 fracture calcaneus Type II (29.2%), 23 Type III (47.9%) [Figure 9]a and b], and 11 Type IV (22.9%). We achieved good alignment in all cases except four (8.3%) feet who had varus deformity at the last follow-up; all were Type IV Sanders. At the last follow-up, the mean total AOFAS was 84.6 ± 5 (total 100), while the mean pain score of the AOFAS was 27.3 ± 8.2 (total 40).
Figure 9: (a) A lateral radiograph in a 23-year-old female with right calcaneal fracture, (b) preoperative computed tomography scan showing calcaneal fracture Sander Type III
Superficial pin tract infection occurred in seven feet (14.6%) and was controlled with local antibiotics and frequent pin care. We had no deep infection. Skin pressure necrosis at the site of Schanz pin was seen in three feet (6.3%). These patients were managed by enzymatic debridement by collagenase-containing formulas as the pressure necrosis was only confined to the edge of the Schanz pin. None of them needed any surgical intervention till the time of removal. No patient developed reflex sympathetic dystrophy.
The range of movement of the subtalar joint was >25° in 39 feet (81.2%). In nine feet (18.8%), the range of movement of the subtalar joint was <25°; six of them were Type IV Sanders and three were Type III. Full or almost full range of movement of the ankle joint was achieved in 46 of 48 cases, and no arthritic changes of the ankle joint were noted at the last follow-up. Twenty-one patients (43.8%) had arthritic changes in the subtalar joint; 8 of 11 (72.8%) were Type IV Sanders, 12 of 23 (52.2%) were Type III, and 1 of 14 (7.1%) was Type II [Table 1].
Statistically, all radiological measures (Bohler's angle, calcaneal length, height, and width) were improved and significantly different from those measured preoperatively [Figure 10]. Restoration of calcaneal anatomy was notable as there is no statistical difference between normal and postoperative radiological measures at 44.9 ± 6.9 months after removal of external fixator (using the uninjured side in unilateral cases as a reference to normal [Table 2]).
Figure 10: A follow-up lateral radiograph 3 years after treatment
The management of DIACFs remains controversial. Many recent meta-analyses and prospective comparative trials have demonstrated that the evidence to support ORIF is weak compared to nonoperative treatment.,, To improve the functional outcome after DIACFs, we used Ilizarov frame to achieve restoration of the calcaneal shape and consequently the foot and ankle kinematics. We used distraction technique through the mechanical axis of the leg and through the foot axis to restore the height, width, and length of the calcaneus. We used drop wire technique to restore depressed subtalar fragments instead of open reduction through minimal skin incisions. We also did not use bone graft after the reduction as the calcaneus is a spongy bone and has the ability for bone formation. We believed, as others,, that the use of bone graft in the treatment of the intra-articular calcaneal fracture was not mandatory. However, many authors , used structural bone graft to strengthen the crushed neutral triangle and provide mechanical support to the previously depressed thalamic portion.
Different scores for evaluating treatment outcomes in calcaneal fractures had been used by various authors: AOFAS score,,,, Maryland Foot Score,, and Creighton–Nebraska Health Foundation Assessment score., The variables assessed in these evaluation systems differ, and the scores allocated to each of the assessment variables also differ a great deal. We have used the AOFAS score in this study as a functional outcome measure because it has been reported to be the most commonly used scoring system for foot and ankle conditions and it may help provide the best comparison tool between different studies.,, We believed that there is an urgent need for “a common language for evaluating calcaneal fractures.”
In the systematic review of Veltman, the mean AOFAS score in 25 studies was 73.7. They have evaluated studies with either surgical or conservative treatment of calcaneal fractures. Their findings suggested that DIACFs should be treated surgically, with ORIF as the method of choice. Makki  reported on 43 DIACFs treated operatively at a mean follow-up of 10 years. Their average AOFAS score was 85. They concluded that ORIF of DIACFs should be considered to restore the shape of the hindfoot and Bohler's angle. Emara and Allam  reported the outcome of 12 patients with Sander's Type III fractures treated by Ilizarov external fixator and compared them with the outcome of a control group having the same type of fracture but treated with ORIF. Using the AOFAS score to assess the outcome, they found similar functional outcomes: 88.2 in the Ilizarov group and 88.6 in the ORIF. They concluded that the use of Ilizarov for reduction and fixation seems to be a safe and effective alternative to ORIF in patients with poor skin condition. In our study, we followed up a series of forty patients with 48 Sanders II, III, or IV calcaneal fractures treated with closed reduction using Ilizarov technique for 44.9 ± 6.9 months after removal of external fixator. At the last follow-up, the mean AOFAS score was 84.6 ± 5. Our relatively better result than in Veltman  systematic review is mainly because our study did not assess the outcome of any conservative case. Nevertheless, its similarity to the other results proves the validity of the technique of closed reduction to get reliable and lasting good outcome.
In our study, 14.6% of the feet developed superficial pin tract infections, whereas 6.3% had skin pressure necrosis. Skin pressure necrosis was reported in 3 feet at the beginning of using our technique when the Schanz pin was introduced percutaneously (without skin incision but just a snip). This was rectified in subsequent cases by opening a skin incision about 1 cm to introduce the Schanz pin without pressure on the skin. In spite of that, our rate of infection and necrosis is still lower than those reported in previous studies using external fixation.,,
No patient in our series developed reflex sympathetic dystrophy. The Ilizarov external fixator permits partial to full early weight bearing in all patients. This may be helpful in desensitization of the heel fat pad and thus prevent chronic heel pad pain and dystrophy.,
A few studies have evaluated the treatment outcome of DIACFs with direct biomechanical measurements. Two studies have evaluated treatment outcome with direct kinematic measurements after DIACFs treated nonoperatively., These studies demonstrated significant restrictions of the ankle and hindfoot motions in injured feet compared with contralateral noninjured feet and healthy controls., Catani  evaluated the function of the ankle–foot complex and the overall gait pattern after fracture of the os calcis and they compared the results of surgical and nonsurgical treatment. They found that patients in whom the geometry of the os calcis and joint was restored by reconstructive surgery had better compensation of gait and a better clinical-functional score, while complex disturbances in gait were found in the group of patients who did not undergo open reduction or internal fixation. Hetsroni  assessed the kinematic profiles of the foot and ankle articulations after open reduction with internal fixation of high-grade intra-articular fractures of the calcaneus. They found that when the gross calcaneal anatomy is recreated during the operation, walking ankle motion is recreated as well. On the other hand, subtalar motions, although recreated to a certain extent, still demonstrate limitations when compared with noninjured individuals. Their results support the advisability of the operation in these complex injuries but demonstrated that subtalar motion is not completely normalized despite a favorable anatomic outcome. The results of the previous studies clearly identify the relevance between restoration of the calcaneal anatomy and the favorable biomechanical outcome of the foot and ankle motion. In our study, we did not perform direct kinematic evaluation of the ankle and hindfoot, but our goal was based on the restoration of the calcaneal anatomy and joint congruency which is proved to be directly linked to restoration of the normal biomechanics of the foot and ankle after these complex fractures.
The normal motion in the subtalar joint was reported to have great variations from a minimum of 20° to a maximum of 60° of motion. With our surgical technique, full or almost full range of movement of the ankle joint was achieved in 46 of 48 cases. The range of movement of the subtalar joint was more than 25° in 39 feet (81.2%). Similar mobility in the ankle and subtalar joints has been reported in literature after open reduction and osteosynthesis with a plate.,, However, Buch  reported a worse range of motion in the ankle and subtalar joints after performing a percutaneous wire osteosynthesis in 100 calcaneal fractures with a varus or valgus deviation of the hind foot occurring in half of the cases. In our study, we achieved good alignment in all cases except 4 (8.3%) feet who ended up with varus deformity at the last follow-up; all were Type IV Sanders.
Thermann  reported arthritic changes in the subtalar joint in 65.2% of Type II fractures and in 81.7% of Type III/IV fractures. Sanders  reported the results of ORIF for Type II and III Sanders in 108 fractures for a minimum follow-up period of 10 years. Thirty-one of their patients (29%) developed subtalar arthritis, requiring an arthrodesis for unrelenting pain during the follow-up period. They also reported that subtalar fusion was performed in 47% of Type III fractures versus only 19% of Type II fractures which means that Type III fractures were four times more likely to need a fusion compared with Type II fractures. In our series of 48 patients, 21 patients (43.8%) had arthritic changes in the subtalar joint; 8 of 11 (72.8%) were Type IV Sanders, 12 of 23 (52.2%) were Type III, and 1 of 14 (7.1%) was Type II. The Ilizarov external fixator allowed slight controlled distraction of the subtalar joint. It is thought that creating a space between the bony surfaces and minimizing the mechanical stress will encourage fibrous repair of defects of the articular cartilage and preservation of an intact and congruent articular surface., In spite of the relatively high rate of subtalar arthritis in our series and comparable figures in the literature especially in Sanders Type III and IV, none of our patients with subtalar arthritis needed subtalar fusion until the end of follow-up. The difference in the need for subtalar fusion between our series and Sanders  could be due to their considerably longer follow-up (15.2 years in average). Even if subtalar fusion is needed later for considerable percentage of DIACF's patients, especially Sanders Type III and IV, it was reported that surgical restoration of the calcaneal shape, alignment, and height will facilitate the fusion procedure and establishes an opportunity to create a better long-term functional result with fewer wound complications.
A significant loss of height, severe shortening, and widening of the calcaneus can lead to late sequelae like anterior impingement (due to loss of calcaneal height) and lateral hindfoot pain as a result of compression of the peroneal tendon sheath (by widening of the calcaneus). In our series, restoration of calcaneal anatomy was notable as there is no statistical difference between normal and postoperative radiological measures at 44.9 ± 6.9 months after removal of external fixator.
Although our results were encouraging, this study had limitations. First, we had a small sample size and there is no control group so we cannot say whether our treatment approach is superior to that of others. Second, follow-up in this study was limited to 44.9 ± 6.9 months after removal of external fixator and we believe that patients should be evaluated at 10 years for valid conclusions to be drawn. Third, the assessment of radiologic changes was made by one observer without calculating intraobserver error.
Based on these observations, closed reduction of DIACFs using Ilizarov frame is a reasonable option as it provides a good functional foot outcome with a low risk of postoperative complications. It also has the capability of restoring the normal height, shape, and length of the calcaneus. Further studies with larger sample size and longer follow-up are required to confirm these findings.
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