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.

Avulsion fracture of the calcaneal tuberosity treated with novel surgical technique using the combination of the side-locking loop suture technique and ring pins: a case report

A 78-year-old woman complained of right heel pain when tripping during walking. Radiographs revealed an avulsion fracture of the calcaneal tuberosity. Because the bone fragment was displaced, a novel osteosynthesis using the side-locking loop suture (SLLS) and ring pins was performed. At 3 months after the surgery, non-contrast computed tomography revealed complete bone union. At 2 years postoperatively, she had no symptoms and dysfunctions. Here, we describe a case of avulsion fracture of the calcaneal tuberosity in a 79-year-old female who treated with a novel surgical technique using combination the SLLS technique and ring pins. This surgical technique may be a useful option in the treatment for avulsion fractures of the calcaneal tuberosity.

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.

Achilles tendon complex: The anatomy of its insertional footprint on the calcaneus and clinical implications

The Achilles tendon is the largest, and most commonly torn tendon in the body. The Achilles is usually torn at a region of relative hypo-vascularity proximal to its insertion. However, partial thickness tears and other pathologies often occur at its insertion on the calcaneus. Anatomically, the insertion is a confluence of the gastrocnemius and soleus muscles that fuse to form a myotendinous unit on the posterosuperior aspect of the calcaneus. This review aims to reveal the insertional footprint as individual fascicular components attaching to facets of calcaneal tuberosity. Understanding this anatomy is essential for interpreting tear patterns and surgical implications.

Cadaveric Anatomical Study of Sural Nerve: Where is The Safe Area for Endoscopic Gastrocnemius Recession?

Purpose:

To ascertain in cadavers where the sural nerve crosses the gastro-soleus complex and where the gastrocnemius tendon merges with the Achilles tendon in relation to the calcaneal tuberosities.

Methods:

Twelve cadaveric lower limbs (6 right and 6 left) were dissected. The distances between the calcaneal tuberosities and the lateral border of the Achilles tendon where the sural nerve crosses from medial to lateral, as well as to the gastrocnemius tendon insertion into the Achilles tendon, were measured.

Results:

The mean and median longitudinal distances from the calcaneal tuberosity to where the sural nerve crosses the lateral border of the Achilles tendon are 9.9cm and 10cm respectively (range 7cm to 14cm). The mean and median longitudinal distances from the calcaneal tuberosity to where the gastrocnemius tendon inserts into the Achilles tendon are 19.9cm and 18.5cm (range 17cm to 25cm) respectively.

Conclusion:

It is generally safe to place the posterolateral incision more than 14cm above the calcaneal tuberosity to avoid the sural nerve if surgeons plan to use a posterolateral incision for endoscopic recession. The distance between the calcaneal tuberosity to the gastrocnemius tendon insertion into the Achilles tendon is too highly variable to be used as a landmark for locating the gastrocnemius insertion.

Avulsion fracture of the calcaneal tuberosity: classification and its characteristics

Background

Not much is known regarding avulsion fractures of the calcaneal tuberosity. We propose a modified classification scheme that presents the four types of calcaneal avulsion fracture as described by surgical and magnetic resonance imaging (MRI) findings, and evaluation of their specific features.

Methods

Out of 764 cases of calcaneal fractures, we examined 20 cases (2.6%) that involved the tuberosity of the calcaneus. Each case was classified depending on the avulsed fracture patterns as follows; type I is a 'simple extra-articular avulsion' fracture, type II is the 'beak' fracture, type III is an infrabursal avulsion fracture from the middle third of the posterior tuberosity, and finally in type IV there is the 'beak', but a small triangular fragment is separated from the upper border of the tuberosity. We examined the features of each avulsed type according to several criteria including patient age, gender, anatomical variances of the Achilles tendon, the fibers involved and the mechanism of injury.

Results

The type I fracture (8/20 cases) was the most common and likely to occur in elderly women. However, in other types, they were more common in relatively younger male patients. Type I were usually caused due to an accidental trip causing a fall by the patient. However, the dominant cause of type II (5/20 cases) fractures a direct blow or hit directly to the bone. Type III (4/20 cases) and IV (3/20 cases) fractures were likely to occur due to falling. All fibers within the Achilles tendon are involved in both type I and II fractures. However, only the superficial fibers are involved in type III fractures, whereas the deep fibers are involved in type IV fractures.

Conclusions

The avulsion patterns of the calcaneal tuberosity fractures are the result of several factors including the bony density level, the mechanism of injury and the fibers of the Achilles tendon that transmit the force. Accurate diagnosis of type III and IV is dependant on MRI technology to confirm the specific location of the injury and provide proper patient treatment therapeutics.