Diagnosing And Treating Calcaneal Tuberosity Fractures

Calcaneal fractures and their complications can lead to long-term problems for athletes, which can make it difficult to resume play. Tuberosity avulsion fractures of the calcaneus are rare, accounting for 1.3 to 2.7 percent of all calcaneal fractures.¹ These fractures involve the posterosuperior aspect of the calcaneus and are not within the subtalar joint.²

Fractures of the tuberosity most commonly result from a moment of forced dorsiflexion of the foot at the ankle coupled with contraction of the gastrocnemius-soleus complex, which can occur in athletes. Contraction of the gastrocnemius-soleus complex at the time of the injury increases the pull of the tendo-Achilles at its insertion, creating an avulsion-type fracture.² The avulsion fracture line of the posterosuperior calcaneal tuberosity runs through the transverse plane, thus separating the upper part of the tuberosity. The proximal pull of the Achilles tendon then creates the characteristic superiorly displaced fracture fragment.³

Several types of tuberosity avulsion fractures exist. Anatomical variations of the insertion of the tendo-Achilles into the posterior calcaneus can result in these different types of avulsion fractures. Beavis and colleagues proposed a classification system taking these variations into account.¹

A Type I fracture is a “sleeve” fracture. With this injury, a shell of cortical bone is avulsed from the posterior tuberosity.¹ A Type II fracture is the classic “beak” fracture. These injuries demonstrate an oblique fracture line running posteriorly from just behind Bohler’s angle. Both Type I and Type II fractures occur in patients having a more proximal insertion of the tendo-Achilles.¹ The final variant is a Type III fracture. Type III fractures are infrabursal avulsion fractures of the middle third of the posterior tuberosity. A Type III avulsion fracture results in individuals with a broader insertion of the tendo-Achilles into the calcaneus.¹

Avulsion fractures of the posterosuperior tuberosity of the calcaneus most often occur in the elderly patient population.³ These arise as insufficiency fractures and frequently occur with no history of trauma.4 Osteoporosis, osteomalacia, diabetes mellitus and peripheral neuropathy are risk factors for developing these fractures.²

When Patients Present With Calcaneal Avulsions

When an athlete presents with a calcaneal avulsion or beak fracture, it is pertinent to evaluate the skin of the posterior heel. Although one can treat minimally displaced fractures non-operatively, it is considered an orthopedic emergency if the fracture fragment impinges upon or compromises the skin of the heel.^1-3,5

In a study by Gardner and colleagues, 29 out of 139 tongue-type fractures developed some level of skin breakdown.⁶ If any skin tenting or blanching is present, one must reduce and fixate the fracture to prevent skin necrosis.² Furthermore, the presence of multiple comorbidities should alert the surgeon to an increased risk of wound complications with this injury. In their case series of 33 patients with calcaneal avulsion fractures, Gitajn and colleagues found that diabetes, peripheral vascular disease, hypothyroidism and the presence of more than one comorbidity were significantly associated with soft tissue complications.⁷

Surgeons can maintain reduction through a variety of implant options. Screw fixation, tension band wiring, suture anchors and even suturing the avulsed bone fragment back in place are all proposed methods of reduction. The choice of technique depends on the size of the avulsion and the quality of the bone stock. Beavis and colleagues proposed the consideration of tension band wiring or suture anchors for Type I fractures as these typically have limited bone stock for fixation. For Type II fractures, surgeons can utilize interfragmentary screw fixation as these fractures have increased osseous area in comparison to Types I and III. Finally, for Type III fractures, Beavis and colleagues suggest suturing the tendon to the calcaneus.

Glanzmann and colleagues described the successful treatment of athletes with avulsion fractures of the calcaneal tuberosity using an anchor system.⁸

Case Study: Treating A Type II Beak Fracture Of The Calcaneal Tuberosity

A 55-year-old female presented to the emergency department with a complaint of pain in her right heel and difficulty walking. She relates a history of trying to push her foot into her slipper at home when she felt the pain and was subsequently unable to push off on her foot.

Physical evaluation in the emergency department demonstrated pain to palpation of the posterior right heel and calf with mild edema to this area. There was an area of palpable bony protuberance at her posterior heel. Additionally, the patient was unable to plantarflex her foot against resistance.

Non-weightbearing AP, lateral and calcaneal axial radiographs demonstrated a classic Type II beak fracture of her calcaneal tuberosity. Further examination did not demonstrate any blanching, tenting or impingement of the skin.

Of note, the patient’s past medical history was significant for hypertension, hypercholesterolemia, diabetes mellitus, morbid obesity and schizophrenia. Additionally, she admitted to being a current pack-a-day smoker.

The patient went to the operating room the following morning and had percutaneous reduction using two crossing screws. She subsequently wore a below-knee fiberglass cast with her foot in a plantarflexed position.

Dr. Saleena Niehaus is in private practice at Advanced Regional Center for Ankle and Foot Care in State College, Pa.

Dr. Les Niehaus is in private practice at Niehaus Foot and Ankle Clinics in Alliance, Ohio.

References

1. Beavis RC, Rourke K, Court-Brown C. Avulsion fracture of the calcaneal tuberosity: a case report and literature review. Foot Ankle Int. 2008; 29(8):863-866.
2. Hess M, Booth B, Laughlin RT. Calcaneal avulsion fractures: complications from delayed treatment. Am J Emer Med. 2008; 26(2):254-e1.
3. Lui TH. Avulsion fracture of the posterosuperior tuberosity of the calcaneus managed with lag screw fixation. Foot Ankle Surg. 2016; epub Nov. 16.
4. Cho BK, Park JK, Choi SM. Reattachment using the suture bridge augmentation for Achilles tendon avulsion fracture with osteoporotic bony fragment. Foot. 2017; 31:35-39.
5. Rijal L, Sagar G, Adhikari D, Joshi KN. Calcaneal tuberosity fracture: an unusual variant. J Foot Ankle Surg. 2012; 51(5):666-668.
6. Gardner MJ, Nork SE, Barei DP, et al. Secondary soft tissue compromise in tongue-type calcaneus fractures. J Orthopaed Trauma. 2008; 22(7):439-445.
7. Gitajn IL, Abousayed M, Toussaint RJ, et al. Calcaneal avulsion fractures: a case series of 33 patients describing prognostic factors and outcomes. Foot Ankle Spec. 2015; 8(1):10–17.
8. Glanzmann M, Veréb L, Habegger R. [Avulsion fracture of the calcaneal tuberosity in athletes]. Unfallchirurg. 2005;108(4):325-6.
9. Miyamura S, Ota H, Okamoto M, et al. Surgical treatment of calcaneal avulsion fracture in elderly patients using cannulated cancellous screws and titanium wire. J Foot Ankle Surg. 2016; 55(1):157-160.
10. Lowery RBW, Calhoun JH. Fractures of the calcaneus Part I: Anatomy, injury mechanism, and classification. Foot Ankle Int. 1996; 17(4):230-235.