Calcaneal Avulsion Fractures: A Multicenter Analysis of Soft-Tissue Compromise and Early Fixation Failure

Osteosynthesis using a plate lacking the anterior component and canulated cancellous screws to treat an avulsion fracture of the calcaneal tuberosity: A case report

INTRODUCTION

Avulsion fractures of the calcaneal tuberosity with significant displacement can cause soft tissue complications in the heel. However, a treatment strategy for calcaneal tuberosity fractures with poor heel-skin condition is yet to be established. Here, we report a case involving avulsion fracture of the calcaneal tuberosity presenting with superficial skin necrosis that was treated with a plate lacking the anterior component and screws inserted percutaneously.

PRESENTATION OF CASE

A 74-year-old woman presented with progressive right heel pain following an injury to her heel sustained approximately six weeks previously. She had experienced difficulty walking due to heel pain and superficial necrosis was observed on the posterior surface of the heel. Radiography and computed tomography revealed an avulsion fracture of the calcaneal tuberosity with superior displacement. Open reduction was performed using a lateral L-shaped incision. After inserting two cancellous screws percutaneously into the calcaneal tuberosity, we fixed a plate lacking the anterior component to the lateral surface of the calcaneus. The superficial necrosis healed gradually post-operatively. Bone union was confirmed using radiography six months post-operatively.

DISCUSSION

We developed a novel surgical procedure to treat avulsion fractures of the calcaneal tuberosity with poor skin condition. The combination of a plate lacking the anterior component and the percutaneous insertion of canulated cancellous screws can reduce the risk of post-operative soft tissue complications while maintaining fixation of the fractured fragment.

CONCLUSION

Our findings provide a novel surgical method for the treatment of avulsion fractures of the calcaneal tuberosity with soft tissue complications.

Analysis of Calcaneal Avulsion Fractures Treated Surgically and Nonsurgically: A Retrospective Multicenter Study

Background

Calcaneal avulsion fractures (CAvFs) at the Achilles tendon insertion are among the more challenging fractures to treat. Although rare, they often require reoperation. The optimal treatment, including nonsurgical procedures and better implants for surgical procedures in the treatment of CAvFs, remains to be established. Therefore, our study aimed to (1) perform a descriptive evaluation of CAvFs, including cases managed nonsurgically, and (2) assess surgical procedures, including the incidence of complications and reoperation for surgically treated CAvFs.

Methods

In this multicenter retrospective study, we collected data of patients with CAvFs treated at 9 hospitals from 2012 to 2022. We performed a descriptive study of CAvFs and compared postoperative complications and reoperation rates for multiple surgical techniques and implants. The size of the bone fragments was quantified.

Results

The data of 70 patients with CAvFs were analyzed; 20 patients were treated nonsurgically, and 50 were treated surgically. The mean age of patients was 68.5 years; 67% of the patients were female. Nineteen percent of the patients had diabetes, and 19% had osteoporosis. The incidence of postoperative complications was 30%, with infection in 14%, necrosis in 26%, and loss of reduction in 18%. The reoperation rate was 22%. Surgical techniques with use of cannulated cancellous screws were performed in 80% of the surgical cases. Cannulated cancellous screw (CCS) fixation alone resulted in a reoperation rate of 35%, whereas additional augmentation, including washers with CCS fixation, resulted in a reoperation rate of 10%. CCS fixation was successfully performed, although suture anchors were used in some cases with smaller fragments.

Conclusions

CAvFs occurred more frequently in older women and had a high rate of postoperative complications. A combination of CCS with augmentation was more effective at reducing postoperative complications than CCS fixation alone, even when the bone fragment size was small.

Level of Evidence

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Calcaneal tuberosity avulsion fractures - A review

Calcaneal tuberosity avulsion fracture, an extra-articular injury, is a rare fracture caused internally by Achilles tendon driven following intense contraction of gastrocnemius-soleus complex, and externally by low-energy (possibly high-energy). Moreover, the risk of injuries of the skin and Achilles tendon around calcaneal tuberosity is closely related to Lee classification and Carnero-Martín de Soto Classification of calcaneal tuberosity avulsion fracture. Although the diagnosis confirmed by X-ray, digital imaging and computed tomography (CT), magnetic resonance imaging (MRI) should also be used to evaluate soft tissue. In recent years, the understanding of this fracture has witnessed the development of different internal fixation devices and surgical procedures. These advances have been further elaborated scientifically in terms of their ability to provide stable fracture reduction ad resistance to Achilles tendon forces. In order to obtain a comprehensive knowledge of the disease, this article reviewed the new understanding of the anatomy, typing, risk factors, and treatment modalities of calcaneal tuberosity avulsion fracture in recent years.

Thickness of simple calcaneal tuberosity avulsion fractures influences the optimal fixation method employed

Aims

This study aimed to establish the optimal fixation methods for calcaneal tuberosity avulsion fractures with different fragment thicknesses in a porcine model.

Methods

A total of 36 porcine calcanea were sawed to create simple avulsion fractures with three different fragment thicknesses (5, 10, and 15 mm). They were randomly fixed with either two suture anchors or one headless screw. Load-to-failure and cyclic loading tension tests were performed for the biomechanical analysis.

Results

This biomechanical study predicts that headless screw fixation is a better option if fragment thickness is over 15 mm in terms of the comparable peak failure load to suture anchor fixation (headless screw: 432.55 N (SD 62.25); suture anchor: 446.58 N (SD 84.97)), and less fracture fragment displacement after cyclic loading (headless screw: 3.94 N (SD 1.76); suture anchor: 8.68 N (SD 1.84)). Given that the fragment thickness is less than 10 mm, suture anchor fixation is a safer option.

Conclusion

Fracture fragment thickness helps in making the decision of either using headless screw or suture anchor fixation in treating calcaneal tuberosity avulsion fracture, based on the regression models of our study.

Hollow screw fixation of type II avulsion fractures of the calcaneal tuberosity using the finite element analysis

We aimed to establish a model of type II avulsion fractures of the calcaneal tuberosity treated with 2 hollow screws implanted in different directions and to analyze the biomechanical properties of the model using the finite element method. The Dicom data of the calcaneal bone obtained after computed tomography scan were inputted into Mimics 21.0 software and Geomagic Studio software to generate a 3D finite element digital model of the calcaneal bone. The model was then imported into SOLIDWORKS 2020 software. Based on the Beavis theory, the calcaneal bone was cut to build a type II avulsion fracture model of the calcaneal tuberosity; the calcaneal fracture was then simulated by internal fixation using hollow screws. Two screws were used to fix the calcaneal bone from the calcaneal tuberosity in different ways, resulting in 3 different calcaneal models (Model 1 involved 2 screws for fixing the fracture vertically; Model 2 had 2 screws for fixing the fracture cross-wise; and Model 3 had 2 screws for fixing the fracture parallelly). Three internal fixation models were loaded under the same conditions, and lines finite element analysis was then performed to calculate the stress distribution of the generated internal fixation models. Under the same loading conditions, compared with Models 2 and 3, Model 1 exhibited smaller maximum displacement values of the heel bone, maximum equivalent force values of the screws, and more dispersed stresses. Avulsion fractures of the calcaneal tuberosity can be treated using 2 screws to fix the fracture vertically (Model 1), which is more biomechanically relevant.

Biomechanical Comparison of a Novel 3-Screw Fixation vs Conventional 2-Screw Fixation of Calcaneal Tuberosity Avulsion Fractures

BACKGROUND

Calcaneal tuberosity avulsion fractures are challenging to treat because of the poor bone stock and high risk of fixation failure secondary to the strong Achilles tendon pull. The purpose of this study is to compare the tensile force to failure of 2 different types of screw fixation construct in a cadaveric model of calcaneal tuberosity avulsion fracture.

METHODS

An oblique osteotomy was created in the calcanei of 7 matched pairs of cadaveric specimens to simulate a tuberosity avulsion fracture and one specimen from each pair randomized into one of the 2 groups for comparison. Two cancellous screws were inserted perpendicular to the fracture line at the posteromedial and posterolateral corners of the avulsed fragment for the 2-screw construct. For the second group, an additional stab incision was made at the midline of the Achilles insertional region for a screw placed between the initial 2 screws with a trajectory toward the calcaneocuboid joint in the 3-screw construct. These specimens were then mounted and loaded to failure.

RESULTS

The mean force to a predefined failure at 3.0-mm gap for the 3-screw construct was 468.7 ± 267.9 N vs 278.9 ± 164.0 N for the 2-screw construct (P < .001). The addition of a central nonparallel screw in the 3-screw construct significantly increased the force required for fracture gap displacement at all cut-off points (1.0-8.0 mm) when compared to the 2-screw construct (P < .001). Notably, the mean peak tensile force for the 3-screw construct was 499.4 ± 255.4 N occurred at the gap displacement of 4.1 mm for the 3-screw construct whereas the mean peak tensile force for the 2-screw construct was 315.9 ± 162.4 N displacing the gap at 4.3 mm.

CONCLUSION

This study showed that an additional central nonparallel screw in the 3-screw construct provided significant mechanical superiority compared to a 2-screw construct.

CLINICAL RELEVANCE

The present study supported the use of augmented fixation with an additional central off-axis screw to reduce risk of fixation failure in calcaneal tuberosity avulsion fractures.

Surgical Fixation of Calcaneal Beak Fractures—Biomechanical Analysis of Different Osteosynthesis Techniques

The calcaneal beak fracture is a rare avulsion fracture of the tuber calcanei characterized by a solid bony fragment at the Achilles tendon insertion. Treatment usually requires osteosynthesis. However, lack of biomechanical understanding of the ideal fixation technique persists. A beak fracture was simulated in synthetic bones and assigned to five different groups of fixation: A) 6.5-mm partial threaded cannulated screws, B) 4.0-mm partial threaded cannulated screws, C) 5.0-mm headless cannulated compression screws, D) 2.3-mm locking plate, and E) 2.8-mm locking plate. Different traction force levels were applied through an Achilles tendon surrogate in a material-testing machine on all stabilized synthetic bones. Outcome measures were peak-to-peak displacement, total displacement, plastic deformation, stiffness, visual-fracture-line displacement, and mode of implant failure. The 2.3- and 2.8-mm plating groups showed a high drop-out rate at 100 N tension force and failed under higher tension levels of 200 N. The fracture fixation using 4.0-mm partial threaded screws showed a significantly higher repair strength and was able to withhold cyclic loading up to 300 N. The lowest peak-to-peak displacement and the highest load-to-failure and stiffness were provided by fracture fixation using 6.5-mm partial threaded cannulated screws or 5.0-mm headless cannulated compression screws. As anticipated, large 6.5-mm screw diameters provide the best biomechanical fixation. Surprisingly, the 5.0-mm headless cannulated compression screws yield reliable stability despite the absent screw head and washer. When such large screws cannot be applied, 4.0-mm screws also allow reasonable fixation strength. Plate fixation should be implemented with precaution and in combination with a restrictive postoperative motion protocol. Finally, clinical cases about the surgical application and recovery are included.

Outcomes of operatively treated calcaneal tuberosity avulsion fractures

BACKGROUND

Calcaneal tuberosity avulsion fractures are uncommon but when present should be treated emergently due to the high risk of skin compromise. Multiple fixation techniques have been reported in the literature but there are little data regarding the ideal fixation construct and outcomes. We aimed to characterize the clinical presentation, focussing on soft tissue compromise and outcomes of operatively treated calcaneal tuberosity avulsion fractures with its associated complications.

METHODS

A retrospective review of all surgically treated calcaneus fracture in our institution from Jun 2008 to Jun 2017 was done. We reviewed patients' demographics, types of avulsion fracture, presence of preoperative skin compromise, age of fracture, time to operation, types of fixation construct, postoperative weight bearing regime, union rates, complications and revision surgeries if present.

RESULTS

We found 9 patients from our database who met the inclusion criteria. They had an average age of 55.6 (range: 43 - 90) years with 5 (55.6%) of them aged 60 years and older. Seven (77.8%) patients were female. Four out of 9 patients (44.4%) presented with soft tissue compromise (3 cases of skin tenting and 1 case of blistering). None of them required soft tissue reconstructive surgery for skin defects postoperatively. However, 2 patients (22.2%) had wound complications after surgery requiring prolonged wound care for up to 4 months. There were 2 patients with fixation failure whereby both were allowed weight bearing prematurely. All of them were able to ambulate independently at their last review.

CONCLUSION

Calcaneal tuberosity avulsion fractures have a high prevalence of soft tissue compromise and warrant early attention. This condition should be treated as both a bony and soft tissue injury rather than just a bony fracture alone. Management of this injury should take into account fracture reduction and stable fixation with neutralization of the Achilles tendon forces.

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.

Calcaneal Fractures-Which Approach for Which Fracture?

Treatment of calcaneal fractures has to be tailored to the individual pathoanatomy. If operative treatment is chosen, anatomic reconstruction of the calcaneal shape and joint surfaces is mandatory. For most of the displaced, intraarticular fractures, this can be achieved by less invasive reduction and fixation via a sinus tarsi approach, which may be extended along the "lateral utility" line for calcaneocuboid joint involvement or calcaneal fracture-dislocations. Purely percutaneous fixation is the treatment of choice for displaced extraarticular fractures and simple intraarticular fractures with adequate control of joint reduction. Specific approaches are used for rare calcaneal fracture variants.

Novel Technique for Osteosynthesis of Tongue-Type Calcaneus Fractures in Osteoporotic Bone: A Case Report

CASE

A 75-year-old woman with osteoporosis sustained a low-energy mechanism tongue-type calcaneus fracture. Index surgical fixation with conventionally described cannulated screws was complicated by early screw pull-out despite concomitant Achilles lengthening procedure. Using a novel technique, revision fixation was performed using a 5.0-mm condyle bolt from a retrograde femoral nail system and 2 cannulated screws. She recovered uneventfully and demonstrated union at 7 months postoperatively.

CONCLUSION

Osteosynthesis of tongue-type calcaneus fractures using a condyle bolt can be a practical and readily available solution for primary and revision scenarios in osteoporotic tongue-type calcaneus fractures.