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RETRACTION: Open reduction internal fixation versus minimally invasive percutaneous fixation for calcaneus fractures: Mid-term outcomes and social consequences

Fahri Emre1, Ceyhun Çağlar2, Özgür Kaya3

1Department of Orthopedics and Traumatology, Ankara Gülhane Training and Research Hospital, Ankara, Turkey
2Department of Orthopedics and Traumatology, Ankara City Hospital, Ankara, Turkey
3Department of Orthopedics and Traumatology, Lokman Hekim Etlik Hospital, Ankara, Turkey

Keywords: Calcaneal varus, calcaneus fracture, minimally invasive cannulated fixation, plate fixation

Abstract

Objectives: This study aims to evaluate the mid-term clinical, functional, radiological, and socioeconomic outcomes of calcaneus fractures treated with open reduction-internal fixation (ORIF) versus minimally invasive percutaneous fixation (MIPF).

Patients and methods: A total of 48 patients (34 males, 14 females; mean age: 44.05 years; range, 19 to 64 years) who underwent either ORIF or MIPF for calcaneus fractures between January 2010 and January 2016 were retrospectively analyzed. The patients were divided into two groups as the ORIF group (n=36) and MIPF group (n=12). The American Orthopaedic Foot & Ankle Society (AOFAS) score, Maryland Foot Score (MFS), and the Short Form-36 (SF-36) scores were assessed for the clinical assessment. The mean duration of operation, mean length of hospitalization, pedobarographic gait analysis, the incidence of contralateral knee pain, increased shoe size, and change of profession due to significant heel pain were also evaluated. The Böhler’s angle, Gissane angle, and calcaneal varus were measured for radiological assessment.

Results: There was a significant difference in the mean operation time (p=0.001) and length of hospitalization (p=0.001) between the two groups. There was no significant difference between the pre- and postoperative third-year Böhler’s and Gissane angles (p=0.05, p=0.07, p=0.09, respectively). There were no significant differences between the postoperative first-, second-, and third-year AOFAS, MFS, and SF-36 scores (p=0.57, p=0.55 p=0.85, p=0.64, p=0.21, p=0.51, p=0.20, p=0.15, p=0.22, respectively). Thirteen patients in the ORIF group and five patients in the MIPF group changed their job due to significant heel pain. The increased shoe size was correlated with the residual calcaneal varus (p=0.001).

Conclusion: Both methods have pros and cons in the treatment of calcaneal fractures. Although MIPF is more advantageous in terms of operation duration and length of hospitalization, more favorable radiological results can be obtained with ORIF. Calcaneal varus should be corrected to prevent the increased shoe size and contralateral knee pain.

Introduction

Calcaneus fractures comprise 2% of all the fractures and 60% of the tarsal fractures.[1] They are commonly encountered following high-energy traumas, such as falling from a height or traffic accidents.[2] These fractures are more common in adult men, leading to significant socioeconomic results, such as prolonged sick leave and even change of profession.[3]

There are various treatment options for displaced intraarticular calcaneal fractures.[4] Several studies have compared the clinical and radiological results of open reduction-internal fixation (ORIF) via an extended lateral approach (ELA) and several minimally invasive-percutaneous fixation (MIPF) methods.[5-9] These fractures have social consequences as well as clinical and radiological outcomes.

Disability and persistent pain can be encountered after calcaneal fractures.[9] Prolonged standing, limited mobility, and pain may compromise the social or professional life of an individual, resulting in changes in their lifestyle, social activities, and even their profession to assure a more sedentary life.

In the present study, we aimed to evaluate the mid-term clinical and radiological results of calcaneal fractures treated with ORIF versus MIPF. We also discuss socioeconomic effects of the disease such as change of profession, changes in the patients' shoe wear and its relevance with residual calcaneal varus, and the incidence of postoperative contralateral knee pain, which are rarely studied in the literature.

Patients and Methods

Achilles tendon's lateral and medial sides not to exceed the calcaneocuboid joint after adequate reduction. After measuring the screw length and drilling, two proper length screws were placed (Figure 1).

Figure 1. An intraoperative fluoroscopy image showing percutaneous fixation.

During the ORIF procedure, after correcting hindfoot alignment via a Steinmann pin (Zimed Medikal, Gaziantep, Turkey) placed at the tuber calcanei, a 2.7-mm profiled calcaneal locking plate through ELA was used. After a thorough irrigation, the flap was closed utilizing the Allgower-Donati suture technique over a suction drain (Figures 2, 3).

Figure 2. Intraoperative images showing surgical steps of open reduction: (a) Identification of bony landmarks and incision planning, (b) Incision and the subperiosteal elevation of flap, (c) Temporary Kirschner wires for “no-touch” handling of flap, (d) completed plate osteosynthesis, (e, f) Flap closure utilizing Allgower-Donati technique over a suction drain, (g) Postoperative second week clinical picture.
Figure 3. Fluoroscopic view after open reduction-internal fixation.

Postoperative care and clinical assessment

No immobilization was used, and suction drains were removed 24 h after surgery. The patients were encouraged for postoperative immediate active and passive ankle range of motion exercises, and weight- bearing (WB) was not allowed for the first six weeks. The WB, as tolerated, was encouraged afterwards. Fracture union was evaluated with plain radiographs at the third postoperative month.

The American Orthopaedic Foot & Ankle Society (AOFAS) score, Maryland Foot Score (MFS), and Short Form-36 (SF-36) scores were used for the clinical assessment at the yearly postoperative follow-up visits. The mean time from hospital admission to surgery, duration of the operation, postoperative complications, and the initiation time of WB were obtained from the patients' charts. The incidence of contralateral knee pain, which was absent before the injury, and pre- and postoperative third-year shoe sizes were recorded at the third postoperative year of follow-up. We also investigated whether the patient

This single-center, retrospective
was conducted at Ankara Gülhane Training and Research Hospital, Department of Orthopedics and Traumatology between January 2010 and January 2016. A total of 66 patients who underwent either ORIF or MIPF for calcaneus fractures were screened. Three patients with significant medical comorbidities preventing surgical intervention (e.g., severe cardiovascular disease, cerebrovascular disease), one open fracture, three bilateral calcaneus fractures, six polytrauma patients, one patient with systemic infection, two diabetes mellitus patients, and two peripheral arterial disease patients were excluded from the study. Finally, a total of 48 patients (34 males, 14 females; mean age: 44.05 years; range, 19 to 64 years) who underwent either ORIF or MIPF for calcaneus fractures with a minimum three-year follow-up were included in the study. The patients were divided into two groups as the ORIF group (n=36) and MIPF group (n=12). A written informed consent was obtained from each patient. The study protocol was approved by the University of Health Sciences Ethics Committee (Date: 30.11.2020, No: 2020/427). The study was conducted in accordance with the principles of the Declaration of Helsinki.

Surgical technique

All patients were placed in the lateral decubitus position with the affected extremity upward after applying prophylactic intravenous cephazolin.

During the MIPF procedure, closed reduction of the fracture was achieved under fluoroscopic control and two guidewires for 4-mm cannulated screws were placed via stab incisions from the had to change his/her job after this injury due to significant heel pain.

Gait analysis

Load distribution on the foot sole was evaluated by Rs scan international 0.5 m Entry Level Footscan® (RSscan International®; Olen, Belgium) system for gait analysis. This device takes precise plantar pressure measurements with 4096 sensors at a scanning rate of up to 300 Hz or 300 measurements per sec. By walking the patients on this platform, plantar pressure areas (forefoot, midfoot, and heel) in both the affected and contralateral unaffected foot were recorded. Pedobarographic gait analysis was performed at the postoperative first year.

Radiological assessment

Pre- and postoperative third-year anteroposterior (AP) and lateral ankle views and Harris views were obtained for all of the patients, and Böhler's angle, Gissane angle, and the calcaneal varus were evaluated.[10] The Sanders classification was used to evaluate the preoperative computed tomography (CT) scans.

Statistical analysis

Power analysis of the study was performed using the G*Power version 3.1.9.2 software (Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany). With type 1 error=0.005 and effect size (d)=0.85, the study power was calculated as 0.78 (78%).

Statistical analysis was performed using the IBM SPSS version 21.0 software (IBM Corp., Armonk, NY, USA). Descriptive data were expressed in mean ± standard deviation (SD), median (min-max) or number and frequency, where applicable. The Student t-test and Mann-Whitney U test were used to compare the numerical data, while the chi-square test was used to compare the categorical data. One- way analysis of variance (ANOVA) test was used to compare more than two groups. Pearson correlation analysis was carried out for the correlation analysis. A p value of <0.05 was considered statistically significant.

Results

Of the ORIF group, 69.4% (n=25) were males with a mean age of 43.4±9.3 (range, 19 to 64) years. Of the MIPF group, 75% (n=9) were males with a mean age of 46±6 (range, 36 to 55) years. There were two main etiological factors for calcaneus fractures: falling from a height (75%) and traffic accidents (25%). The mean follow-up was 6.2±1.7 (range, 4 to 9) years in the ORIF group and 5.8±1.7 (range, 4 to 9) years in the MIPF group. The fracture type distribution was similar between the groups. The mean time from admission to surgery, duration of surgery, and length of hospitalization were shorter in the MIPF group (p=0.001, p=0.001, p=0.001, respectively). Also, the full WB time was earlier in the MIPF group than the ORIF group (p=0.01) (Table I).

Table 1. Comparison of patients’ data

There was no significant difference between the two groups in terms of the AOFAS, MFS, and the SF-36 scores at the first, second, and third postoperative years. The mean pre- and postoperative third-year Böhler's and Gissane angles were also similar, indicating no statistically significant difference between the two groups (p=0.05, p=0.07, p=0.09, respectively) (Table II).

Table 2. Comparison of the postoperative first-, second-, and third-year clinical scores of the ORIF and the MIPF groups

The mean preoperative calcaneal varus was 16.21±6.41° in the ORIF group and 17.15±5.21° in the MIPF group (p>0.05). The mean postoperative calcaneal varus was 7.91±5.84° in the ORIF group and 10.66±6.86° in the MIPF group (p>0.05). Postoperative varus degree was significantly lower in the ORIF and MIPF group than preoperative values (p=0.026 and p=0.032, respectively). A total of 13 patients (27.1%) reported a one-unit increase in their shoe size, compared to the contralateral foot at the postoperative third-year follow-up. Ten of these 13 patients with the increased shoe size were in the ORIF group. No significant difference was found between the increase in shoe size and the surgical method (p=0.05). The mean calcaneal varus for the 13 patients with the increased shoe size was 17.41±3.89°, while it was 5.66±3.26° for the remaining 35 patients. The increased shoe size was significantly related to the increased calcaneal varus (p=0.001). There was no significant correlation between the severity (Sanders type) of the fracture and the shoe size change (Table III).

Table 3. Relationship between the shoe size increase, the change of profession, and Sanders type

Thirteen patients (36%) in the ORIF group and five patients (42%) in the MIPF group changed their job after this injury due to significant heel pain, indicating no significant difference between the groups (p=1.00). There was no significant correlation between the severity (Sanders type) of the fracture and change of profession (Table III).

The incidence of contralateral knee pain, which was absent before the injury, was also investigated. Contralateral knee pain occurred in a mean time of 1.5±0.6 years. Regardless of the surgery type (ORIF or MIPF), none of the patients with Sanders type 2 fractures had contralateral knee pain, which was statistically significant (p=0.951). Also, there was no significant difference in contralateral knee pain between the ORIF or MIPF groups (p=0.59) (Table IV). The mean AOFAS scores of the patients with the contralateral knee pain were significantly lower than the patients with no pain at the postoperative first, second, and third year.

Table 4. Relationship between surgical technique, Sanders type, and contralateral knee pain

In the pedobarographic analysis, differences in the distribution of the plantar pressure were detected between the operated foot and contralateral healthy foot. While the plantar pressure decreased in the heel area of the affected foot, an increase was observed in the plantar pressure, particularly in the second metatarsal head (forefoot) and around it (Figure 4). Pedobarographic gait analysis revealed no significant difference between the groups regarding overloading at the contralateral extremity. All of the patients with contralateral overloading reported contralateral knee pain, which was statistically significant (p=0.0001) (Table V).

Figure 4. Pedobarographic gait analysis: The pink line parallel to the second metatarsal from middle of heel and the black line drawn from heel's middle to the first metatarsal. The dotted black line parts showing load distribution of patient’s foot.
Table 5. Relationship between surgical technique, contralateral knee pain, and contralateral extremity overload

In the ORIF group, five patients (13.9%) had a superficial wound infection managed with local debridement, wound care, and oral antibiotics, while one patient (2.8%) developed subtalar arthrosis requiring subtalar arthrodesis. None of the patients had wound problems in the MIPF group, whereas one patient (8.3%) developed subtalar arthrosis requiring subtalar arthrodesis. No other complications were encountered, and there was no statistically significant difference between the two groups in terms of complications (p=0.810).

Discussion

Extended lateral approach provides adequate exposure of the articular surfaces, as well as the whole calcaneal length for restoration. However, this approach is commonly associated with complications such as hematoma, skin breakdown, skin necrosis, and superficial or deep infections.[7] The disruption of the inadequate arterial supply and the relatively thin subcutaneous tissue at the lateral hind food increases the risk of these complications.[11] Therefore, many authors have advocated alternative techniques such as the closed reduction and MIPF or less invasive ORIF to reduce the impact of wound complications.[6,12-15] This approach was later modified and popularized by Gissane and Essex-Lopresti.[8] To date, several studies have compared ORIF by ELA and several minimally invasive methods.[5-9] In this study, we compared these two methods.

Ebrahimpour et al.[16] reported that returning to work was significantly shorter for the MIPF technique than the ORIF. Peters et al.[17] retrospectively evaluated 44 calcaneus fractures and reported that eight patients changed their professions after surgery. Schuh and Hausel[18] also reported that only 68% of their patients were active in the same profession. In our study, similarly, 36% (n=13) of the patients in the ORIF group and 42% (n=5) of the patients in the MIPF group changed their profession due to heel pain after long-term standing. In this study, the profession change rates were similar between the groups Also, there was no statistically significant difference between the patients, whether they changed their job or not, in terms of the AOFAS, SF36, and MFS clinical scores.

A recent meta-analysis of Zeng et al.[19] discussed the minimally invasive versus extensile lateral approach for Sanders type 2 and 3 calcaneal fractures. Their data showed that the minimally invasive approach yielded 15.3% absolute and 88% relative risk reduction for wound complications. In our study, five patients (13.9%) in the ORIF group had superficial wound infection, and none of the patients in the MIPF group had any wound problems.

The most common shortcoming of the minimally invasive approaches is the incomplete reduction and unstable fixation in complex fractures.[20] However, a recent biomechanical study has revealed that the locking plates are not biomechanically advantageous over other fixation techniques, except for the osteoporotic bone.[21] In the present study, no significant difference was found between the groups in radiological comparisons. None of the patients had a loss of reduction at their second- and third-year follow-up.

In their study, Ebrahimpour et al.[16] reported that the mean time from hospital admission to surgery and the duration of operation were significantly shorter in the MIPF group than the ORIF group. Our findings are consistent with these results. Percutaneous reduction and fixation can be performed earlier, as it is essential to wait for the “wrinkle sign” to minimize wound-related problems for the ELA (Figure 5). This delay naturally leads to the increased interval between the hospital admission and surgery. Furthermore, our data showed that MIPF yielded a significantly shorter hospitalization period (2.25 days) than the ORIF group, which is consistent with the literature.

Figure 5. Positive “wrinkle sign” of a patient with Sanders type 3 calcaneal fracture one week after trauma.

In another study, Peng et al.[22] compared the clinical and radiological results of MIPF and ORIF in patients with calcaneal fractures. The authors found no statistically significant difference in the postoperative AOFAS scores. In another clinical study reported by Weng et al.,[23] similar results were achieved. In our study, there was no statistically significant difference between the two groups in terms of the AOFAS, MFS, and the SF-36 scores at the first, second, and third postoperative years.

Pedobarography is an effective method to identify functional deficiencies of foot and ankle, including calcaneal fractures.[24] Pedobarographic evaluation can measure the pressure distribution under the foot during walking and to identify complex changes in joint kinematics after intra- articular calcaneus fractures. Previous studies have demonstrated significant biomechanical deviations and plantar pressure abnormalities in both injured and healthy feet.[25-27] In our study, plantar pressure increase was measured at the head of the second metatarsal compared to the contralateral foot. Of note, there may be changes after the plantar pressure distribution of the affected foot after calcaneal fracture.

Residual foot and heel pain are significant complaints following calcaneal fractures, commonly after long standing and walking periods. Some of the patients require walking aids such as canes or sticks. They tend to redirect their body weight to the contralateral side of the affected extremity and experience gait asymmetry.[28] It is demonstrated that lower extremity problems cause contralateral knee overload, even chondral lesions of the knee.[28] In a pedobarographic study by Schepers et al.,[29] patients who underwent surgery for calcaneal fractures put more weight on the healthy foot than the affected foot. Our pedobarographic analysis data objectively reveal this phenomenon. Consequently, contralateral knee pain absent before the injury can be encountered later. Compared to the fracture type, contralateral knee pain was less in Sanders type 2 than the AOFAS. The AOFAS score was lower in those with pain in the contralateral knee.

Another concern after calcaneal fractures is the increase in the shoe size. O'Farrell et al.[30] reported that, in 11 of 24 patients, up to two size increase was identified in their shoe sizes. A meta-analysis reported that surgically treated calcaneal fractures had a less shoe size increase compared to the conservatively treated group.[11] In our study, a total of 13 patients reported an increase in their shoe size, compared to the contralateral foot. This finding is significantly related to the increased residual calcaneal varus. Therefore, it is essential to correct the varus deformity to prevent this complication.

The main limitations of this study are its retrospective design and relatively low sample size in the MIPF group. Although retrospective design of the study prevented to include similar number of patients or fracture types to the groups, the distribution was statistically similar.

In conclusion, both methods have pros and cons in the treatment of calcaneal fractures. Although MIPF patients have a shorter length of hospitalization, shorter operation duration, and earlier WB, clinical scores reveal no significant difference between the groups. Also, both methods yield similar change of profession, shoe size increase, and contralateral knee pain rates. Calcaneal varus is related to poor results and should be corrected to prevent the increased shoe size and contralateral knee pain.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.

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