Fixation Methods for Calcaneus Fractures: A Systematic Review of Biomechanical Studies Using Cadaver Specimens

Locking vs. non-locking plate fixation in comminuted talar neck fractures: a biomechanical study using cadaveric specimens

BACKGROUND

Talar neck fractures are rare but potentially devastating injuries, with early reduction and rigid fixation essential to facilitate union and prevent avascular necrosis. Even small degrees of malunion will alter load transmission and subtalar joint kinematics. Changes in fixation techniques have led to dual plating strategies. While locked plating has perceived advantages in porotic bone and comminution, its biomechanical benefits in talar neck fractures have not been shown.

AIM

To compare the strength of locking vs. non-locking plate fixation in comminuted talar neck fractures.

METHOD

Seven pairs of cadaveric tali were randomised to locking or non-locking plate fixation. A standardised model of talar neck fracture with medial comminution was created, and fixation performed. The fixed specimens were mounted onto a motorised testing device, and an axial load applied.

RESULTS

Peak load to failure, deformation at failure, work done to achieve failure, and stiffness of the constructs were measured. No statistically significant difference was found between locking and non-locking constructs for all parameters.

CONCLUSIONS

Both constructs provide similar strength to failure in talar neck fracture fixations. Mean peak load to failure did not exceed the theoretical maximum forces generated of 1.1 kN when weight-bearing. We would advocate caution with early mobilisation in both fixations.

Minimally invasive K-wire fixation of displaced intraarticular calcaneal fractures through a minimal sinus tarsi approach

BACKGROUND

Displaced intra-articular calcaneal fractures are challenging injuries, and there is debate regarding the best method of treatment.

PATIENTS AND METHODS

Between January 2018 and January 2021, a prospective study was conducted on 46 patients with 56 displaced intraarticular calcaneal fractures that were treated with minimally invasive fixation using Kirschner wires (KWs) through the sinus tarsi approach.

RESULTS

The mean follow-up period was 22.36 months. The American Orthopaedic Foot and Ankle Society (AOFAS) score was adopted as a method of clinical evaluation; the mean AOFAS score was 78.4. All cases showed radiographic evidence of adequate healing, with no collapse till the final follow-up. Complications included persistent pain, subtalar arthritis, deep infection and superficial pin site infection.

CONCLUSION

The use of the sinus tarsi approach and percutaneous KWs represents a minimally invasive approach which expands the indications of surgery for displaced intra-articular calcaneal fractures with fewer treatment-related complications. Level of evidence (4) case series. Trial registration This study has been approved by the ethical research committee of the Faculty of Medicine, Tanta University, under the code: 35901/10/22.

Optimal posterior screw placement configuration in Sanders 2B calcaneal fractures: A biomechanical study

BACKGROUND

Calcaneal fractures can be high energy intra-articular injuries associated with joint depression. Challenges to fracture reduction include lateral wall blow out, medial wall overlap, comminution and central bone loss. Secondary deformity such as hindfoot varus alters foot biomechanics. Minimally invasive approaches with indirect reduction of the calcaneal tuberosity to maintain the reduction using posterior screws is routinely being used in the treatment of joint depression fractures. Biomechanically, optimum screw numbers and configuration is not known. Biomechanical studies have evaluated and proposed different screw configurations, however, it is not clear which configuration best controls varus deformity. This study aims to determine the optimum screw configuration to control varus deformity in Sanders 2B calcaneal fractures.

METHODS

Sawbone models were prepared to replicate Sanders type 2-B fracture, with central bone loss and comminution. 0.5 cm medial wedge of the calcaneal tuberosity was removed to create varus instability. After stabilising posterior facet with a single 4 mm partial threaded screw, and applied an 8 hole contoured plate to stabilise the angle of Gissane, inserted one or two 7 mm cannulated partially threaded Charlotte^TM (Wright Medical Technology, Memphis, USA) Headless Multi-use Compression (under image guidance) extra screws to control varus and subsidence deformity of the fracture. Coronal plane displacement of the dissociated calcaneal tuberosity fragment relative to the body when applying 5 N, 10 N and 20 N force was measured in millimetres (mm).

RESULTS

2 screws inserted (one medial screw into the sustentaculum talus from inferior to superior and, one lateral screw into the long axis anterior process) provides the least displacement (0.88 ± 0.390 at 5 N and 1.7 ± 1.251 at 20 N) and the most stable construct (p < 0.05) when compared to other configurations. A single medial screw into the sustentaculum tali (conf. 3) resulted in the least stable construct and most displacement (4.04 ± 0.971 at 5 N and 11.24 ± 7.590 at 20 N) (p < 0.05).

CONCLUSION

This study demonstrates the optimal screw configuration to resist varus in calcaneal fractures using minimally invasive techniques. Optimal stability is achieved using 2 screws; one located along the long axis of the calcaneus (varus control) and the other placed in the short axis directed towards the posterior facet of the calcaneus (control varus and subsidence). Further cadaver research would help evaluate optimal screw placement in simulated fractures to further assess reproducibility.

Optimal posterior screw placement configuration in Sanders 2B calcaneal fractures: A biomechanical study

BACKGROUND

Calcaneal fractures can be high energy intra-articular injuries associated with joint depression. Challenges to fracture reduction include lateral wall blow out, medial wall overlap, comminution and central bone loss. Secondary deformity such as hindfoot varus alters foot biomechanics. Minimally invasive approaches with indirect reduction of the calcaneal tuberosity to maintain the reduction using posterior screws is routinely being used in the treatment of joint depression fractures. Biomechanically, optimum screw numbers and configuration is not known. Biomechanical studies have evaluated and proposed different screw configurations, however, it is not clear which configuration best controls varus deformity. This study aims to determine the optimum screw configuration to control varus deformity in Sanders 2B calcaneal fractures.

METHODS

Sawbone models were prepared to replicate Sanders type 2-B fracture, with central bone loss and comminution. 0.5cm medial wedge of the calcaneal tuberosity was removed to create varus instability. After stabilising posterior facet with a single 4mm partial threaded screw, and applied an 8 hole contoured plate to stabilise the angle of Gissane, inserted one or two 7mm cannulated partially threaded Charlotte™ (Wright Medical Technology, Inc. 5677 Airline Road Arlington, TN) Headless Multi-use Compression (under image guidance) extra screws to control varus and subsidence deformity of the fracture. Coronal plane displacement of the dissociated calcaneal tuberosity fragment relative to the body when applying 5N, 10N and 20N force was measured in millimetres (mm).

RESULTS

2 screws inserted (one medial screw into the sustentaculum talus from inferior to superior and, one lateral screw into the long axis anterior process) provides the least displacement (0.88±0.390 at 5N and 1.7±1.251 at 20N) and the most stable construct (p<0.05) when compared to other configurations. A single medial screw into the sustentaculum tali (conf. 3) resulted in the least stable construct and most displacement (4.04±0.971 at 5N and 11.24±7.590 at 20N) (p<0.05).

CONCLUSION

This study demonstrates the optimal screw configuration to resist varus in calcaneal fractures using minimally invasive techniques. Optimal stability is achieved using 2 screws; one located along the long axis of the calcaneus (varus control) and the other placed in the short axis directed towards the posterior facet of the calcaneus (control varus and subsidence). Further cadaver research would help evaluate optimal screw placement in simulated fractures to further assess reproducibility.

Fixation of intra-articular calcaneal fractures: A comparative study of the postoperative outcome between HA/PPLA screws and locking plates

Background

Forged unsintered hydroxyapatite and poly l-lactic acid (F-u-HA/PLLA) screw is bioactivite, bioabsorbable, and radiopaque with high mechanical strength. Its efficacy has been previously demonstrated in the treatment of lateral humeral condylar, lateral tibial condylar, ankle, and patellar fractures. However, studies on its efficacy in treatment of calcaneal fractures is lacking. This study aimed to compare the postoperative results of F-u-HA/PLLA screw fixation and locking plate fixation for intra-articular calcaneal fractures.

Methods

From January 2013 to December 2019, 47 closed intra-articular fractures treated with either F-u-HA/PLLA screws (group S, 18 feet in 17 patients) or locking plates (group P, 29 feet in 28 patients) in a single trauma center were retrospectively reviewed. The sinus tarsi approach was used in both groups. The time to bone union, step-off, varus deformity, Bohler's angle, and width and height of the calcaneus were assessed after surgery. Ankle joint range of motion (ROM) and postoperative complications were also assessed.

Results

All fractures were successfully treated. The Kaplan-Meier curves of the two groups showed similar trends. The log-rank test showed no significant difference in the time to bone union between the two groups (p = 0.48). In the Cox proportional hazards model adjusted for preoperative width and Bohler's angle, the hazard ratio for bone union was not statistically significant (HR: 1.13, 95%CI: 0.50-2.56, p = 0.78). Other variables included step-off (group S: 2.0 vs group P: 2.2 mm, p = 0.84), varus deformity (2.0° vs. 3.0°, p = 0.7), Gissane's angle (103.5° vs 104.0°, p = 0.84), width (38.0 vs 34.8 mm, p = 0.12), height (42.1 vs 44.0 mm, p = 0.07), and ankle ROM degrees (dorsal flexion, 20.0° vs. 20.0°, p = 0.13; plantar flexion 40.0° vs 40.0°, p = 0.56), which were not significantly different between groups P and S. The Bohler's angle was smaller in group S than in group P (20.5° vs 27.0°, p < 0.01). No skin necrosis or infection was observed in either group.

Conclusion

Postoperative results of F-u-HA/PLLA screw fixation using the sinus tarsi approach for intra-articular calcaneal fractures were as good as those of locking plate fixation.

Comparison of Robot-Assisted Percutaneous Cannulated Screws Versus Open Reduction and Internal Fixation in Calcaneal Fractures

OBJECTIVE

Accurate placement of the screws is challenging in percutaneous cannulated screw fixation of calcaneal fractures, and robot-assisted (RA) surgery enhances the accuracy. We investigated the outcome of percutaneous cannulated screw fixation of Sander's type II and III calcaneal fractures.

METHODS

This retrospective study analyzed clinical data of 26 patients with fresh closed calcaneal fractures (28 fractures) who were admitted to our center from January 2022 to July 2022. All fractures were divided into the RA group and the open reduction and internal fixation (ORIF) group according to the surgeries performed. RA surgery was performed by closed reduction or open reduction combined with a tarsal sinus approach. Age, sex, operation time, preoperative waiting time, length of postoperative hospital stay, wound complications, and American Orthopaedic Foot and Ankle Society Ankle Hindfoot Scale (AOFAS) at 3 months postoperatively were compared. Preoperative and postoperative radiographic parameters (calcaneal length, width, height, Böhler angle, and fixation rate of the sustentaculum tali) were documented. The chi-square test, one-way analysis of variance, and Wilcoxon test were used for the comparison of categorical, normally distributed, and nonnormally distributed continuous variables, respectively.

RESULTS

The calcaneal width, height, and Böhler angle were significantly corrected postoperatively in both groups. The postoperative calcaneal lengths in both groups were also corrected. However, no significant difference was found. No significant differences in calcaneal length, width, height, and Böhler angle were observed between the two groups. The operation time (p < 0.001), preoperative waiting time (p < 0.001), and length of postoperative hospital stay (p = 0.003) in the RA surgery group were significantly shorter than those in the ORIF group. The fixation rate of the sustentaculum tali (p < 0.001) in the RA surgery group was significantly superior to that in the ORIF group. All wound complications occurred in the ORIF group. All fractures healed within 3 months. The AOFAS scores at 3 months postoperatively were not significantly different.

CONCLUSION

RA percutaneous screw fixation of the calcaneal fracture is a safe, effective, rapid, and minimally invasive surgical option for surgeons.

Percutaneous fixation of intraarticular joint-depression calcaneal fractures with different screw configurations - a biomechanical human cadaveric analysis

PURPOSE

The aim of this study was to assess the biomechanical performance of different screw configurations for fixation of Sanders type II B joint-depression calcaneal fractures.

METHODS

Fifteen human cadaveric lower limbs were amputated and Sanders II B fractures were simulated. The specimens were randomized to three groups for fixation with different screw configurations. The calcanei in Group 1 were treated with two parallel longitudinal screws, entering superiorly the Achilles tendon insertion, and two screws fixing the intraarticular posterior facet fracture line. In Group 2 two screws entered the tuberosity inferiorly to the Achilles tendon insertion and two transverse screws fixed the posterior facet. In Group 3 two screws were inserted along the bone axis, one transverse screw fixed the posterior facet and one oblique screw was inserted from the posteroplantar part of the tuberosity supporting the posterolateral part of the posterior facet. All specimens were biomechanically tested to failure under progressively increasing cyclic loading.

RESULTS

Initial stiffness did not differ significantly between the groups, P = 0.152. Cycles to 2 mm plantar movement were significantly higher in both Group 1 (15,847 ± 5250) and Group 3 (13,323 ± 4363) compared with Group 2 (4875 ± 3480), P ≤ 0.048. No intraarticular displacement was observed in any group during testing.

CONCLUSIONS

From a biomechanical perspective, posterior facet support by means of buttress or superiorly inserted longitudinal screws results in less plantar movement between the calcaneal tuberosity and the anterior fragments. Inferiorly inserted longitudinal screws are associated with bigger interfragmentary movements.

Avulsion Fractures of the Calcaneal Tuberosity: A Single-Center Review of Outcomes and Complications

OBJECTIVES

The goal of this investigation was to determine the incidence of complications and revision surgery after calcaneal tuberosity avulsion fractures, to describe experience with different fixation constructs, and to compare revision surgery rates between tuberosity and tongue-type fractures of the calcaneus.

DESIGN

This was a retrospective study at a single level 1 trauma center between 2001 and 2019, including patients with calcaneal tuberosity avulsion fractures compared with patients with calcaneal tongue-type fractures.

RESULTS

Twenty-nine tuberosity fractures (23 surgical and six nonsurgical) and 37 tongue-type fractures (29 surgical and eight nonsurgical) were treated during the study period. Revision surgery was more common in the tuberosity group (26% versus 7%, P = 0.013). In the tuberosity group, 35% experienced some degree of implant failure, with 13% catastrophic loss of reduction and 22% loss of initial reduction with eventual union. Fragment size and initial displacement were not associated with revision surgery. No patients with implant failure noted in the tongue-type group.

DISCUSSION

Calcaneal tuberosity fractures showed significantly higher rate of revision surgery and failure of fixation compared with tongue-type fractures.

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

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.

Limited Open Reduction and Internal Fixation of Calcaneal Fractures

BACKGROUND

The treatment of displaced intra-articular calcaneal fractures remains a challenge and the optimal approach is still controversial. The main reason to avoid the extended lateral approach is the high complication rate due to wound healing problems. We report on 16 years of experience with a standardized limited open reduction and internal fixation technique.

METHODS

Between 2001 and 2017, we prospectively followed 240 consecutive patients operatively treated for a displaced intra-articular calcaneal fracture. Patients with open, multiple, bilateral, extra-articular, and Sanders IV fractures and those lost to follow-up were excluded. A lateral subtalar approach was used, with a cast for 8 weeks and full weightbearing allowed after 12 weeks. Follow-up examinations were scheduled until 24 months. Subjective and clinical assessment included gait abnormality, subtalar and ankle range of motion, and stability and alignment. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score was calculated. Alignment was analyzed on standard radiographs. In total, 131 patients were excluded. The remaining 109 patients were followed for a minimum of 24 months (34.4 ± 14.2 [range, 24-102] months).

RESULTS

The mean AOFAS score was 87 ± 13 (range, 32-100). "Excellent" and "good" results, as well as hindfoot motion with "normal/mild" and "moderate" restrictions, were seen in 80% of patients. Early reoperations were performed for insufficient reduction (2 patients), delayed wound healing (debridement, 3 patients), and hematoma (1 patient). Late revisions were arthrodesis (3 patients), medializing calcaneal osteotomy (1 patient), and implant removal (53 patients; 49%).

CONCLUSION

The presented approach has remained unmodified for 16 years and resulted in consistently good functional results. The main disadvantage was the high rate of heel screw removal.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Surgical treatment of displaced intraarticular calcaneal fractures by a minimally invasive technique using a locking nail: A preliminary study

BACKGROUND

The aim of this retrospective study was to evaluate the outcome of patients with intra-articular calcaneal fractures treated using a minimally invasive locking nail (Calcanail^®).

METHODS

Between January 2016 and April 2017, 15 patients (9 men and 6 women) with a calcaneal fracture were consecutively treated with Calcanail^®. The Böhler angle was recorded on standard X-rays pre- and post-operatively. The articular reduction of the posterior facet was evaluated with the Goldzak index in a CT scan 3 months post-operatively. The mean age of the patients was 53 years (range, 24-78). Mean final follow-up was 18 months (range, 12-24).

RESULTS

Six fractures were classified as Sanders II, 7 as Sanders III and 2 as Sanders IV. In 13 out of the 15 patients treated, the post-operative Böhler angle was of more than 20°. Goldzak index was deemed as excellent in 73.5% of the cases (11 patients), good in 20% of cases (3 patients), and poor in 6.5% (1 patient). Post-operative mean AOFAS score was 85 (range, 60-96).

CONCLUSIONS

The Calcanail^® provides good restoration of the subtalar joint and the calcaneal angles with the advantages of a minimally invasive approach. It was effectively used in Sanders types II and III, even in the presence of poor cutaneous conditions.

Intra-articular calcaneal fractures. Do locking plates keep the reduction better than conventional plates?

INTRODUCTION

Since the development of locking plates, calcaneal fractures have been considered ideal for this type of fixation, due to the need to maintain the height of the subastragaline joint after depression fractures in a location where bone quality tends to be poor. However, there are no comparative studies that support the theoretical superiority of these plates over conventional plates. The aim of this study was to compare the results of intraarticular calcaneal fractures treated using locking plates vs. conventional plates in terms of radiological reduction, complications and number of reinterventions.

MATERIAL AND METHODS

We designed a comparative study of calcaneal fractures operated in our centre using the "L" approach. Two groups were established: group B, comprising 15 patients operated between 2010 and 2015 with calcaneal locking plates, and group A, comprising a stratified random sample of 23 patients taken from a historical cohort of 90 patients operated in our centre between 1997 and 2007 using conventional calcaneal plates. Demographic data were recorded (age, sex, diabetes mellitus, smoking) and data relating to the fracture (type of fracture according to Sander's classification system, complications, presurgical delay). To evaluate loss of reduction, varus angulation of the calcaneus (measured from the axial view), Böhler's angle and Gissane's angle were assessed radiographically. These angles were measured preoperatively, immediately postoperatively, and at the end of follow-up. Finally, we recorded complications and the number of reinterventions.

RESULTS

There were no differences in terms of age, sex or fracture type between the 2 groups. There was greater loss of varus angulation in group A, 0.6 vs. 0.41°, and there was greater reduction in Böhler's angle in group A, 3.79 vs. 2.6°, while Gissane's angle decreased more in group B, 4.13 vs. 2.52°. There were no significant differences in the proportion of complications and reinterventions between the 2 groups.

CONCLUSION

In our study we observed no significant differences between the 2 groups in terms of radiological reduction, complications or number of reinterventions. However, we did observe a greater loss of reduction of Böhler's angle in the patients who were operated using conventional plates.

Primary or Secondary Subtalar Arthrodesis and Revision of Calcaneal Nonunion with Minimally Invasive Rigid Internal Nail Fixation for Treatment of Displaced Intra-Articular Calcaneal Fractures

Primary or secondary subtalar joint arthrodesis after displaced intra-articular calcaneal fractures makes use of talocalcaneal large-diameter screw fixation after an eventual correction of geometric hindfoot deformity. Despite this procedure usually having a successful functional outcome, potential complications occur, including nonunion and malalignment, with an unknown rate of loss of correction or implant migration during the healing period. Angular stable fixation of the subtalar joint arthrodesis with an interlocking nail applied in a minimally invasive technique affords maintenance of the hindfoot position until osseous healing occurs. The key steps of the surgical technique are described.