Authors: Kunming Ren, Yanmei Wang, Jie Zhao, Xuecheng Sun, Xiaoming Yang, Naibo Feng
Categories: Research, Calcaneal fracture, Minimally invasive surgery, Arthroscopy, Distractor, Screw fixation, Randomized controlled trial
Source: Journal of Orthopaedic Surgery and Research
Authors: Kunming Ren, Yanmei Wang, Jie Zhao, Xuecheng Sun, Xiaoming Yang, Naibo Feng
Calcaneus fractures are common orthopedic injuries, often caused by high-energy impacts such as falls from height or direct trauma. These fractures can result in severe pain, swelling, and dysfunction of the heel. Surgical intervention is essential to reduce the risk of post-traumatic arthritis and restore foot function. However, traditional open surgical approaches can lead to complications such as incision infections and skin necrosis due to the extensive soft tissue exposure required. This randomized controlled trial aimed to assess the clinical efficacy of distractor-assisted, arthroscopy-guided minimally invasive screw fixation for treating Sanders type II and III intra-articular calcaneal fractures. Conducted at Weifang People’s Hospital from February 2022 to February 2024, the study involved 60 patients randomized into two a minimally invasive group (n = 30) and an open reduction group (n = 30). The minimally invasive group received distractor-assisted, arthroscopy-guided reduction with percutaneous screw fixation, while the open group underwent open reduction with plate fixation. Primary outcomes included surgical time, incision length, operative duration, intraoperative blood loss, hospital stay, and fracture healing time. Secondary outcomes involved calcaneal dimensions, functional scores (AOFAS, Maryland Foot Function Score, VAS for pain), and complications at one-year follow-up. At one-year follow-up, all fractures had healed, with an average healing time of 12 weeks. The minimally invasive group showed significant advantages in surgical parameters and pain relief, with no significant differences in functional outcomes. In conclusion, distractor-assisted, arthroscopy-guided minimally invasive screw fixation is an effective, minimally traumatic treatment option for Sanders type II and III calcaneal fractures.
The online version contains supplementary material available at 10.1186/s13018-025-05984-w.
Calcaneal fractures are common orthopedic injuries, often resulting from falls from heights, direct blunt trauma, or similar high-energy impacts. These fractures account for approximately 2% of all body fractures and 60% of tarsal fractures [1]. They are typically characterized by severe pain, swelling, and functional impairment of the heel. A thorough understanding of the fracture patterns of the calcaneus is essential for optimizing treatment strategies, as inadequate management may lead to chronic pain or even disability [2, 3]. Displaced fractures can lead to hindfoot deformity, altered biomechanics, and dysfunction of the peroneal tendons [4]. Surgical intervention aims to restore the anatomical structure of the hindfoot and the congruency of the articular surfaces, thereby reducing the risk of post-traumatic arthritis and improving functional outcomes [4, 5].
The most commonly employed approach for open reduction is the “L”-shaped incision along the posterolateral aspect of the calcaneus. While this technique facilitates effective reduction and fixation of the fracture, it demands extensive soft tissue dissection. Given the relative weakness of the surrounding soft tissues and the substantial surgical exposure required, complications such as incision infection and skin necrosis are common postoperative concerns [6–9]. To reduce these complications—particularly soft tissue-related issues—various minimally invasive techniques have been developed, including the sinus tarsi approach for limited open reduction and internal fixation, and percutaneous reduction and fixation [10]. The sinus tarsi approach enables direct visualization and reduction of the posterior facet of the subtalar joint. Some studies have compared the lateral extensile and sinus tarsi approaches, showing that the latter is associated with lower rates of wound infection and subtalar arthritis, with no significant difference in the incidence of sural nerve injury [11]. However, despite its minimally invasive advantages, the sinus tarsi approach is technically demanding and does not provide full visual access to the entire articular surface. This limitation may hinder the surgeon’s ability to assess the adequacy of fracture reduction intraoperatively, potentially increasing the risk of residual joint incongruity and subsequent post-traumatic arthritis [12].
Given the limitations of these approaches, there is a compelling need for more refined and minimally invasive treatment options. In this study, we utilized a distractor combined with arthroscopy-assisted minimally invasive screw fixation in patients with Sanders type II and III calcaneal fractures [13] admitted to Weifang People’s Hospital from February 2022 to February 2024. We compared this approach with traditional “L”-shaped incision plate fixation, aiming to evaluate intraoperative parameters, postoperative recovery, and complication rates, thereby providing a clinical basis for optimizing treatment strategies in the management of calcaneal fractures.
From February 2022 to February 2024, 60 patients with calcaneal fractures who met the inclusion criteria were enrolled and randomly divided into two the minimally invasive group (arthroscopy-assisted closed reduction and screw fixation) and the open group (L-shaped incision plate fixation). All surgeries were performed by a fixed team of three trauma orthopedic surgeons, ensuring consistency in the surgical approach. All patients were followed up for an average of 12 months. This study was approved by the Ethics Committee of Weifang People’s Hospital, Shandong Province (approval number KYL20241113-3).
Inclusion (1) Sanders type II or III fractures; (2) closed fresh fractures (injury duration < 2 weeks). Exclusion (1) Open fractures; (2) Pathological fractures; (3) duckbill fractures, fractures associated with impaction injuries leading to talus fractures, or ankle fractures due to torsion injuries; (4) Patients with concomitant neurological disorders who were unable or unwilling to cooperate with treatment.
The procedure was performed with the patient in the prone position under general anesthesia. A distractor was applied using two 2.0-mm Kirschner one inserted into the tibia at the Chaput point (anterolateral distal tibia), and the other inserted into the calcaneal tuberosity approximately 0.5 cm proximal to the junction of the red and white skin zones on the lateral aspect. Gradual distraction was applied to restore the calcaneal length, width, and height. In cases where correction of varus deformity was insufficient, the distractor was temporarily loosened, followed by lateral distraction and subsequent stronger medial distraction to achieve proper alignment.
Arthroscopic-assisted minimally invasive reduction was performed through lateral and anterolateral portals. Hematoma was debrided, and fracture morphology was evaluated under direct arthroscopic visualization. Intraoperative fluoroscopy (anteroposterior, lateral and broden views of the calcaneus) was used to assess the position of compressed articular fragments. A 4.5-mm K-wire was drilled through the plantar cortex of the calcaneus, serving as a working channel. A 2.0-mm K-wire was used as a pushing rod to elevate the depressed fragments through this tunnel, with the subtalar joint surface monitored arthroscopically to ensure restoration of congruity.
To reduce the posteroinferior calcaneal tuberosity, a 0.5-cm lateral incision was made adjacent to the Achilles tendon. A percutaneous reduction clamp was inserted, with one tip engaging the sustentaculum tali and the other tip clamping the lateral calcaneal wall. Under arthroscopic guidance, closure of the posterior facet was confirmed. Fluoroscopy (lateral, axial, and Broden views) was used to verify reduction quality of the articular surface, as well as restoration of calcaneal length and height. A 1.5-mm K-wire was inserted percutaneously from the lateral approach toward the sustentaculum tali, followed by placement of a 4.5-mm cannulated compression screw.
For Sanders type III fractures, the medial depressed articular fragments were reduced first, followed by reduction of the lateral fragments, and fixation with a 4.5-mm cannulated compression screw. The medial tip of the reduction clamp was maintained in position while the lateral tip was rotated to clamp the posterior calcaneus, allowing correction of calcaneal width. A 5.0-mm cannulated screw was inserted from the posterolateral calcaneal tuberosity toward the sustentaculum tali to maintain length and width. Finally, a 5.0-mm cannulated screw was inserted into the calcaneal tuberosity (Double Medical Technology Co., Ltd., Xiamen, China) to maintain height. All incisions were closed and a compressive dressing was applied.
In the open surgery group, the patient was placed in the lateral position under general anesthesia. An “L”-shaped incision was made on the lateral side of the affected foot, extending from the midpoint of the lateral malleolus and Achilles tendon to the junction of the red and white skin, then continuing in a 90-degree arc to the base of the fifth metatarsal. The lateral wall of the calcaneus was carefully dissected to expose the subtalar joint, which was then reduced.
The length, width, and height of the calcaneus were restored, and the fracture was realigned. A clavicle plate (Double Medical Technology Co., Ltd., Xiamen, China) was used for fixation, and a drainage tube was placed. The incision was closed, and the foot was bandaged appropriately.
Following surgery, the affected limb was elevated to promote venous return and reduce swelling. Prophylactic antibiotics were administered within 24 h postoperatively to prevent infection. Early mobilization of the ankle joint was initiated, gradually progressing through active and passive range-of-motion exercises based on patient pain tolerance. Partial weight-bearing was allowed 6 weeks after surgery, and full weight-bearing functional exercises were commenced following fracture healing.
The primary outcomes included fracture healing and the incidence of complications. Perioperative parameters such as preoperative waiting time, incision length, operative duration, intraoperative blood loss, and hospitalization duration were also recorded.
The Gissane angle was defined as the angle between the anterior and posterior articular surfaces of the calcaneus, while the Bohler angle was measured as the angle formed by the highest point of the posterior articular surface of the calcaneus, the calcaneal tuberosity, and the highest point of the anterior articular surface [14–17]. The length, width, height, Bohler angle, and Gissane angle of the calcaneus were assessed 1 year postoperatively.
Functional outcomes were evaluated using the Ankle and Foot Surgery Association (AOFAS) score, the Maryland Foot Function Index, and the Visual Analogue Scale (VAS) for pain [18]. Postoperative complications were also recorded.
Statistical analysis was performed using IBM SPSS Statistics version 25.0 (IBM Corp., Armonk, NY, USA). The Shapiro–Wilk test was used to assess the normality of continuous variables. Data conforming to a normal distribution were expressed as mean ± standard deviation (x̄±s). An independent samples t-test was used to compare continuous variables between the two groups. Two-way repeated measures analysis of variance (ANOVA) was employed to compare preoperative and 12-month postoperative data between the two groups. If a significant interaction was detected, pairwise comparisons at different time points were conducted using the Bonferroni correction. Categorical variables were compared using the chi-square (χ²) test or Fisher’s exact test, as appropriate. All statistical tests were two-sided, and a p < 0.05 was considered statistically significant.
From February 2022 to February 2024, a total of 60 patients with calcaneal fractures who met the inclusion criteria were enrolled in the study. All surgical procedures were successfully completed, and the patients were followed up for an average duration of 12 months. No statistically significant differences were observed between the minimally invasive group and the open surgery group regarding demographic and clinical characteristics, including age, gender, body mass index (BMI), affected side, injury mechanism, and Sanders classification of calcaneal fractures. The comparison of general patient data between the two groups revealed no statistically significant differences (P > 0.05), as summarized in Table 1.
Table 1Comparison of baseline characteristics between the minimally invasive and open surgery groups before surgeryClinical characteristicsMinimally Invasive Group (n = 30)Open surgery Group (n = 30)P-valueAge (year)37.03 ± 9.0337.37 ± 8.430.665Sex (M/F)19/1121/90.289BMI (kg/m^2^)24.00 ± 1.9623.97 ± 1.010.585Left/Right12/1814/160.359Traffic Accident/ Fall from Height2/283/270.358Classification (Sanders II/III)25/526/40.478
The minimally invasive group demonstrated significantly shorter surgery timing, smaller incision length, reduced operative duration, lower surgical blood loss, and shorter hospital stay compared to the open group. These differences were statistically significant (P < 0.05), as shown in Table 2.
Table 2Comparison of intraoperative parameters between the minimally invasive and open surgery groupsGroupSample SizeTime from Injury to Surgery (day)Incision Length (cm)Surgery Duration (min)Surgical Blood Loss (ml)Length of Hospital Stay (d)Minimally Invasive Group303.90 ± 0.803.23 ± 0.5649.03 ± 5.5818.3 ± 2.696.60 ± 1.03Open Group305.47 ± 1.1115.17 ± 0.6966.87 ± 11.5269.70 ± 13.3912.50 ± 1.50P-value-0.0270.0000.0030.0000.43
The length, height, and width of the calcaneus, as well as the Bohler and Gissane angles, were measured preoperatively and 12 months postoperatively using X-ray imaging [9–12]. No significant differences were observed in the preoperative radiographic parameters between the minimally invasive group and the open surgery group (P > 0.05). However, significant differences were found between the preoperative and 12-month postoperative values within each group for all parameters (P < 0.05), indicating significant radiological improvement over time. Additionally, there were no statistically significant differences in the Bohler angle, Gissane angle, or the length, width, and height of the calcaneus between the two groups at the 12-month follow-up (P > 0.05), as shown in Table 3.
Table 3Comparison of radiographic parameters between the minimally invasive and open surgery groups before and after months after surgeryParameterMinimally Invasive Group (n = 30)Open surgery Group (n = 30)Group Main Effect (F, P)Time Main Effect (F, P)Bohler Angle (°)Preoperative12.49 ± 0.6312.73 ± 0.85(0.014, 0.905)(1354.12, < 0.01)Postoperative 12 months27.90 ± 3.0227.57 ± 2.96Gissane Angle (°)Preoperative76.90 ± 6.5473.20 ± 4.23(3.383, 0.071)(1038.03, < 0.01)Postoperative 12 months112.03 ± 5.63112.47 ± 5.90Calcaneal Length (mm)Preoperative72.53 ± 2.6872.30 ± 3.59(0.004, 0.952)(560.69, < 0.01)Postoperative 12 months81.47 ± 1.8581.77 ± 1.99Calcaneal Width (mm)Preoperative36.30 ± 2.1836.10 ± 1.95(0.017, 0.900)(1104.99, < 0.01)Postoperative 12 months45.53 ± 1.5545.83 ± 1.70Calcaneal Height (mm)Preoperative51.07 ± 3.0252.37 ± 2.28(3.273, 0.076)(619.17, < 0.01)Postoperative 12 months41.70 ± 1.4741.83 ± 1.52
No statistically significant difference was observed in foot function scores between the minimally invasive group and the open surgery group (P > 0.05). However, the VAS pain score in the minimally invasive group was significantly lower than that in the open surgery group (P < 0.05). Regarding complications, the complication rate in the minimally invasive group was 3.3% (1/30), consisting of 1 case of sural nerve injury. In contrast, the complication rate in the open surgery group was 13.3% (4/30), which included 2 cases of skin necrosis and 2 cases of chronic pain, and a statistically significant difference was found between the two groups (P < 0.05), as summarized in Table 4.
Table 4Ankle-hindfoot score and Maryland foot function assessment according to the AOFAS scoring systemParameterMinimally Invasive Group (n = 30)Open surgery Group (n = 30)P-valueAOFAS Score82.00 ± 2.4282.17 ± 2.790.547Maryland Foot Function (Excellent Rate)89%83%VAS Score3.20 ± 0.715.57 ± 0.890.048Complication Rate3.3%13.3%0.004
The patient was a 55-year-old male with a smoking history of over 10 years and no significant medical comorbidities. He was admitted to the hospital following a fall from height, which occurred 3 h prior to presentation, resulting in pain in his right foot. On physical examination, swelling, localized bruising, and no tension blisters were observed on the right foot. There was notable tenderness, palpable crepitus, and restricted ankle dorsiflexion and plantarflexion, while the foot’s blood supply remained intact. Gradually, tension blisters developed around the ankle joint of the affected limb (Fig. 1A and B). Radiographic evaluation, including X-ray and CT imaging, confirmed a right calcaneal fracture, classified as Sanders type IIA (Fig. 1C and F).
Fig. 1A case of calcaneal fracture treated with minimally invasive screw fixation assisted by a traction device combined with arthroscopy. (A-B) Severe tension blisters appeared around the ankle joint of the affected limb. (C-D) Preoperative calcaneal axial and lateral X-ray images of the affected limb. (E-F) Preoperative CT images of the affected limb. (G-H) Intraoperative X-ray evaluation of calcaneal fracture reduction. (I-J) Postoperative CT images of the affected limb. Axial and lateral X-rays were used to evaluate the recovery of calcaneal fractures at 6 weeks (K-L), 10 weeks (M-N), and 14 weeks (O-P) after surgery
Surgical Procedure: Under general anesthesia following endotracheal intubation, the patient was placed in the prone position. A tourniquet was applied to the upper thigh of the affected limb, and routine skin preparation was performed. Kirschner wires were inserted into the calcaneus and tibia, followed by the placement of a distractor. The distractor was used to restore the length, width, and height of the calcaneus. A posterior-lateral, lateral, and anterolateral approach was employed for arthroscopic access. The arthroscopic procedure involved cleaning the joint cavity and synovium to expose the fracture site. A pre-bent 2.0 mm Kirschner wire was used for reduction, and the arthroscope was utilized to monitor the flatness of the joint surface during reduction. The width of the calcaneus was corrected using reduction forceps, followed by sequential insertion and fixation of screws (Fig. 1G and H). Postoperative CT examination showed that the joint surface was well aligned (Fig. 1I and J).
Postoperative Care and Rehabilitation Plan: Postoperatively, cefuroxime was administered for 24 h to prevent infection. On the first postoperative day, toe flexion and extension exercises were initiated. Ankle flexion and extension exercises, along with quadriceps isometric exercises, commenced on the third postoperative day. At 6 weeks post-surgery, partial weight-bearing was permitted with the assistance of a walker. Full weight-bearing was allowed at 10 weeks postoperatively, with return to physical labor at 14 weeks.
The patient’s hospital stay was 6 days. Follow-up evaluations at 6, 10, and 14 weeks post-surgery demonstrated satisfactory fracture healing, with no significant pain and good functional recovery of the affected limb (Fig. 1K and P). The patient’s rehabilitation progressed without complications, and the functional outcome was favorable (Figs. 2, 3).
Fig. 2Another case of calcaneal fracture treated with traction-assisted minimally invasive screw fixation combined with arthroscopy. A 43-year-old male sustained a left calcaneal fracture due to a fall from height. (A-B) Preoperative axial and lateral radiographs of the affected foot. (C) Preoperative CT images reveal three fracture lines involving the posterior facet of the calcaneus, classified as Sanders type III BC. (D–H) Intraoperative reduction of the posterior facet under arthroscopic visualization. (I-J) Postoperative axial and lateral radiographs show restoration of calcaneal length, width, and height, with no obvious varus deformity. (K-L) Postoperative CT scans demonstrate good articular surface congruity
Surgical The patient was placed in the prone position, and a tourniquet was applied at the proximal thigh. Intraoperatively, a distractor was used to restore the length and height of the calcaneus. Under arthroscopic guidance, reduction of the posterior facet of the calcaneus was performed. Bone reduction forceps were applied to compress the posterior subtalar joint space, thereby restoring the width of the calcaneus (D–H). Postoperative radiographs confirmed restoration of calcaneal length, width, and height (I-J), and CT scans demonstrated a smooth and congruent articular surface (K-L).
Fig. 3A case of calcaneal fracture treated with open reduction and internal fixation using a plate. A 44-year-old male sustained a right calcaneal fracture following a fall from height. (A-B) Preoperative axial and lateral radiographs of the affected foot. (C-D) Preoperative CT images show three fracture lines involving the posterior facet of the calcaneus, classified as Sanders type III AB. (E-F) Postoperative axial and lateral radiographs demonstrate restoration of calcaneal length, width, and height, with no obvious varus deformity. (G-H) Postoperative CT scans reveal good congruity of the posterior articular surface. (I) Intraoperative image showing open reduction and internal fixation with an L-shaped incision and plate fixation. (J) Postoperative wound healing status
The patient was placed in the lateral decubitus position, and a tourniquet was applied at the proximal thigh. An “L”-shaped lateral incision was made intraoperatively. Kirschner wires were inserted into the lateral malleolus, talus, and cuboid to retract the flap and expose the fracture site. The depressed posterior facet was elevated, and the length, width, and height of the calcaneus were restored. A plate was used for internal fixation (Figure I). After skin closure, postoperative radiographs confirmed restoration of calcaneal morphology, and CT scans demonstrated a smooth and congruent articular surface (Figure E–H).
The calcaneus, as the largest tarsal bone in the human body, plays a critical role in foot function and weight-bearing. Proper reduction and fixation of calcaneal fractures are essential to restoring the calcaneus’ height, width, length, and articular surface flatness, thereby preventing complications such as traumatic arthritis and joint dysfunction. Traditionally, the lateral “L”-shaped incision has been the standard approach for calcaneal fracture treatment. This method effectively exposes the subtalar articular surface and facilitates anatomical restoration of the calcaneus, but it comes with significant risks, including damage to the lateral arterial network of the calcaneus, skin necrosis, and infection due to the large incision.
Anatomical reduction of the subtalar joint surface is an important prognostic indicator [19]. Poor reduction can lead to pain in the subtalar joint, potentially progressing to subtalar arthritis, which may later require arthrodesis to manage foot pain. Sanders defines a step-off of less than 3 mm in the posterior calcaneal articular surface as close to anatomical reduction. However, biomechanical studies indicate that even a 1–2 mm step-off can alter force distribution, increasing the contact area and force ratio on the protruding part, which may lead to progressive wear and ultimately traumatic arthritis. The posterior calcaneal articular surface is a curved plane, and different projection angles of Broden views can reveal various layers of the posterior calcaneal joint surface. However, in Sanders Type III and IV fractures, small bone fragments may exist within the joint compression area, which can be overlooked on fluoroscopy [20].
With advances in minimally invasive surgical techniques, subtalar arthroscopy has emerged as a promising alternative for calcaneal fracture treatment [21]. Subtalar arthroscopy has been shown to be more reliable than intraoperative Broden fluoroscopy in assessing the articular surface [20]. Therefore, compared with minimally invasive percutaneous screw fixation under fluoroscopic guidance alone, arthroscopically assisted minimally invasive percutaneous screw fixation not only preserves the advantages of reduced soft tissue irritation and a lower risk of skin necrosis, but also allows for more accurate restoration of the articular surface congruity with fewer intraoperative fluoroscopic exposures. In this study, we employed both the lateral and anterolateral approaches using a 4.0 mm arthroscope to directly visualize the joint surface. The posterolateral approach, positioned at the level of the lateral malleolus in front of the Achilles tendon, avoids nerve and vascular structures, making it a safe entry point to access the posterior half of the subtalar joint. It also serves as the third incision for the placement of reduction forceps. The lateral approach, approximately 0.5 cm below the posterior malleolus, serves as the operating window, while the anterolateral approach, located about 2 cm anterior to the lateral malleolus in the tarsal sinus area, allows access to the anterior half of the posterior joint surface. Under arthroscopic guidance, achieving anatomical reduction of the subtalar joint surface significantly reduces the incidence of subtalar arthritis due to poor reduction. Additionally, the smaller incision results in minimal soft tissue damage and a lower rate of skin necrosis. During the follow-up period of the minimally invasive group in this study, no cases of foot pain, skin necrosis, or infection were observed, and soft tissue recovery was favorable, which is consistent with findings reported in the literature.
The advantages of arthroscopic treatment for calcaneal fractures (1) minimal skin incisions—only two 1 cm incisions for the arthroscopic portals, one 0.5 cm incision for the reduction forceps, and two 0.5 cm screw channel incisions at the heel—which minimize soft tissue disruption and reduce the risk of skin necrosis; (2) the ability to clean the joint of blood clots, free bone fragments, and articular cartilage, lowering the incidence of subtalar arthritis; (3) improved visualization of the joint surface, allowing real-time feedback for accurate reduction; and (4) fewer fluoroscopy exposures and reduced surgery duration. In this study, the minimally invasive group showed significant improvements in surgical timing, incision length, blood loss, operation time, and hospitalization compared to the open group, consistent with findings from Grün et al. on arthroscopically assisted percutaneous reduction of Sanders type II and III fractures [22].
Arthroscopy, while a valuable adjunct in the treatment of calcaneal fractures, has certain limitations. A primary challenge is the narrow subtalar joint space, which complicates arthroscopic examination. The use of distractors can expand the subtalar joint space, allowing for improved visualization of the joint surface. Both 2.7 mm and 4.0 mm arthroscopes can be easily introduced into the subtalar joint space, enabling direct observation of the compressed articular surfaces in Sanders Type II and III fractures. The 2.7 mm arthroscope is generally more maneuverable than the 4.0 mm scope, particularly when assisting in reduction of Sanders Type IIC fractures. Pastides et al. successfully utilized 3.0 mm and 4.0 mm arthroscopes in minimally invasive treatments for Sanders Type II and III calcaneal fractures, achieving satisfactory clinical outcomes [23].
Calcaneal fractures are often caused by high-energy trauma, which results in severe soft tissue damage around the calcaneus, making treatment more challenging. With the advent of minimally invasive techniques, distractors have gained popularity for treating periarticular fractures. These devices allow for both anatomical restoration and protection of the surrounding soft tissue. The distractor uses the self-traction of ligaments and the joint capsule to facilitate initial fracture reduction, achieving favorable clinical results. Previous studies, such as those by Fröhlich and Ye et al., have shown the benefits of using distractors in treating calcaneal fractures [24, 25]. Traditionally, the classic distraction technique involves pin placement in the calcaneal tuberosity and talus to restore calcaneal morphology through ligamentotaxis [26]. Multiple studies have confirmed the effectiveness of this setup in restoring the length, height, and width of the calcaneus [24]. Forgon M and Zadravecz G further introduced a 3-point traction method involving the calcaneus, talus, and cuboid in their work [26], while Peng et al. used the calcaneus, tibia, and navicular bones with favorable outcomes [25]. In our study, we further modified Peng’s method by selecting the calcaneal tuberosity and the Chaput point (anterolateral distal tibia) as traction sites, while reduction forceps were employed to correct calcaneal width. This configuration not only achieves reliable restoration of the calcaneal dimensions but also avoids direct traction on the talus, thereby reducing the risk of talar injury and facilitating arthroscopic manipulation during the procedure. The Chaput point provides a stable and accessible site on the distal tibia, and its use is also compatible with standard minimally invasive setups. Reduction under arthroscopic assistance facilitates the restoration of the Böhler and Gissane angles, which are commonly used radiographic parameters to evaluate the quality of calcaneal fracture reduction [27]. No statistically significant differences in these parameters were found between the minimally invasive and open groups after 12 months (P > 0.05), indicating that the distractor technique achieves the same reduction outcomes as open surgery.
The distractor has several (1) It increases the calcaneal-talar joint gap, facilitating arthroscopic observation and evaluation of the joint surface, while providing space for the push-up reduction; (2) it aligns with the mechanical axis of the limb and indirectly restores the calcaneal length, width, and height; (3) it only requires small incisions for Kirschner wire insertion, which minimizes soft tissue damage and reduces preoperative waiting time; (4) the use of a distractor facilitates restoration of foot length and helps to redistribute compressive forces on the impacted fracture fragments, enabling reduction using peripherally inserted fine-diameter Kirschner wires. In this study, the preoperative waiting time in the minimally invasive group was significantly shorter than in the open group (P < 0.05). One year post-surgery, there were no significant differences in calcaneal length, width, height, or angles between the two groups, while the VAS pain scores were significantly lower in the minimally invasive group (P < 0.05), suggesting that the minimally invasive approach results in less postoperative pain.
Sural nerve injury is a common complication in subtalar arthroscopy. The lateral subtalar arthroscopic approach is located near the sural nerve and the peroneal tendons, which can be at risk of injury during surgery. Literature reports nerve injury rates ranging from 0.87 to 6.12% [28]. In this study, one case of sural nerve injury occurred in the minimally invasive group. However, careful handling, such as blunt tissue dissection and protective techniques during screw insertion, can minimize the risk of nerve injury. Another common postoperative issue is chronic pain, often due to bulging of the calcaneal lateral wall. The distractor helps restore the calcaneus width and reduces the incidence of this complication. In the open surgery group, two cases of chronic pain were noted, which may have been related to calcaneal widening during fracture healing.
Despite the positive outcomes of this study, there are some limitations. The sample size was small, which may affect the generalizability of the findings. Additionally, the follow-up period was relatively short, and long-term follow-up is necessary to fully assess the efficacy of this treatment method. Furthermore, only Sanders II and III fractures were included, and the effectiveness of this technique for other fracture types requires further investigation.
In conclusion, the combination of a distractor with arthroscopic minimally invasive screw fixation for the treatment of calcaneal fractures represents an innovative and effective approach. As technology continues to advance, this technique is expected to become more widely adopted. Future studies with larger sample sizes, longer follow-up periods, and biomechanical research will help optimize the surgical approach and confirm the safety and efficacy of this treatment for calcaneal fractures.
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Supplementary Material 1