A calcaneus fracture is a fracture of the heel bone (os calcis) and represents the most common fracture of the tarsal bones. Calcaneal fractures account for approximately 1%–2% of all fractures and nearly 60% of all adult tarsal fractures. Most injuries occur after high-energy trauma such as falls from height or motor vehicle accidents.
Approximately 60%–75% of calcaneus fractures are displaced intra-articular fractures, involving the subtalar joint. These injuries are clinically significant because they may result in chronic pain, subtalar arthritis, loss of hindfoot motion, gait impairment, and long-term disability.
The annual incidence of calcaneal fractures is approximately 11.5 per 100,000 people, with a male predominance (male-to-female ratio approximately 2.4:1). The peak incidence occurs in men aged 20–29 years.
Anatomy of the Calcaneus
The calcaneus is the largest tarsal bone and forms the heel. It plays a critical role in weight transmission and gait mechanics.
Articular Facets
The superior surface contains three articular facets that articulate with the talus:
- Posterior facet – largest and primary weight-bearing surface
- Middle facet – located on the sustentaculum tali
- Anterior facet – often confluent with the middle facet
Between the middle and posterior facets lies the interosseous sulcus, which contributes to formation of the sinus tarsi.
Important Anatomical Structures
Sustentaculum Tali
- Medial bony projection supporting the talus
- Contains the middle facet
- Serves as attachment for the interosseous talocalcaneal ligament
- The flexor hallucis longus tendon passes beneath it
Lateral Structures
- Peroneal tendons course between the calcaneus and lateral malleolus
- Lateral wall blowout may cause tendon impingement
Posterior Structures
- Achilles tendon inserts onto the posterior tuberosity
- Important in avulsion-type fractures
See Also: Ankle Anatomy
Epidemiology
- Accounts for approximately 1%–2% of all fractures
- Most frequently fractured tarsal bone
- Represents approximately 60% of adult tarsal fractures
- Bilateral fractures occur in 5%–10% of cases
- Around 10% are open fractures
- Approximately 70% result from falls from height
- Intra-articular fractures constitute 60%–75% of cases
Mechanism of Injury
Axial Loading
Most intra-articular calcaneus fractures occur due to axial loading injuries, particularly falls from height.
The talus is driven downward into the calcaneus, producing:
- Primary fracture lines through the posterior facet
- Collapse of cancellous bone
- Heel widening and shortening
- Loss of calcaneal height
Motor vehicle collisions may also produce axial loading injuries when the foot strikes the brake pedal.
Twisting Injuries
Twisting forces may cause extra-articular fractures including:
- Anterior process fractures
- Medial process fractures
- Sustentacular fractures
Achilles Tendon Avulsion
In elderly diabetic patients or osteoporotic individuals, forceful Achilles contraction may produce:
- Posterior tuberosity avulsion fractures
Symptoms & Signs
Patients typically present with:
- Severe heel pain
- Inability to bear weight
- Swelling around the hindfoot
- Ecchymosis extending into the plantar arch
- Heel widening and shortening
- Tenderness over the calcaneus
Massive swelling may produce fracture blisters within the first 36 hours.
Important Clinical Findings
Compartment Syndrome
Up to 10% of calcaneal fractures are associated with compartment syndrome of the foot.
Signs include:
- Severe pain
- Tense swelling
- Pain with passive toe movement
- Clawing of the lesser toes
Associated Injuries
Up to 50% of patients have associated injuries, including:
- Contralateral calcaneus fractures
- Lumbar spine fractures (approximately 10%)
- Lower extremity fractures (approximately 25%)
Radiology
Radiographic evaluation of the patient with a suspected calcaneal fracture should include a lateral view of the hindfoot, a Harris axial view, Brodén view and an anteroposterior (AP) and oblique view of the foot:
- The lateral radiograph is used to assess height loss (loss of Böhler angle, Gissane angle) and rotation of the posterior facet.
- The Harris view is made to assess varus position of the tuberosity and width of the heel.
- AP and oblique views of the foot are made to assess the anterior process and calcaneocuboid involvement.
- A single Brodén view, obtained by internally rotating the leg 40° with the ankle in neutral, then angling the beam 10–15° cephalad, is made to evaluate congruency of the posterior facet.
A CT scan helps to further characterize the fracture and position of the peroneal and flexor hallucis tendons. This helps to plan further management.
See Also: Talar Fractures & Dislocation
Calcaneus Fracture Classification
Calcaneal fractures can be extra-articular (not involving the subtalar joint) or intra-articular (involving the sub talar joint).
Extra-articular fractures
Extra-articular calcaneus fractures constitute 25–30% of calcaneal fractures and include the following:
- Anterior process fractures that result from strong plantarflexion and inversion, which tighten the bifurcate and interosseous ligaments leading to avulsion fracture.
- Posterior tuberosity fractures may result from avulsion by the Achilles tendon.
- Medial process fractures are vertical shear fractures that occur due to loading of the heel in valgus.
- Sustentacular fractures that occur with heel loading accompanied by severe foot inversion.
- Body fractures not involving the subtalar articulation. These are caused by axial loading. Significant comminution, widening, and loss of height may occur along with a reduction in the Böhler angle without posterior facet involvement.
Intra-articular fractures
Intra-articular fractures are traditionally classified using the Essex-Lopresti classification or the Sanders classification, which is based on CT scan.
Essex–Lopresti Classification
The Essex-Lopresti system describes fracture patterns produced by axial loading.
Primary Fracture Line
The talus splits the calcaneus through the posterior facet, producing:
- Sustentacular fragment
- Tuberosity fragment
Secondary Fracture Patterns
Tongue-Type Fracture
- Secondary fracture exits posteriorly through the tuberosity.
Joint Depression Fracture
- Secondary fracture exits behind the posterior facet.
- Joint depression fractures are generally more common.
Sanders Classification
The Sanders classification is CT-based and evaluates posterior facet fracture lines:
- Type I: All non-displaced fractures regardless of the number of fracture lines
- Type II: Two-part fractures of the posterior facet; subtypes IIA, IIB, IIC, based on the location of the primary fracture line
- Type III: Three-part fractures with a centrally depressed fragment; subtypes IIIAB, IIIAC, IIIBC
- Type IV: Four-part articular fractures; highly comminuted.
Higher Sanders grades are associated with poorer outcomes and increased risk of subtalar arthritis.
Download Orthopedic Classification App for Android / iOS Devices
Calcaneus Fracture Treatment
Non-Operative Treatment
Indications:
Non-operative management is indicated for:
- Nondisplaced fractures
- Minimally displaced extra-articular fractures
- Patients with severe comorbidities
- Significant soft tissue compromise
- Poor surgical candidates
Treatment includes:
- Bulky Jones splint
- Fracture boot or cast
- Elevation and edema control
- Early ankle and subtalar ROM exercises
- Non-weight bearing for 10–12 weeks
Operative Treatment
Indications:
Surgery may be indicated for:
- Displaced intra-articular fractures
- Tuberosity avulsion fractures
- Open fractures
- Fracture-dislocations
- Significant heel deformity
Surgical Goals
The goals of surgery include:
- Restoration of subtalar congruity
- Restoration of calcaneal height and width
- Correction of varus deformity
- Restoration of Böhler angle
- Prevention of peroneal impingement
Surgical Approaches
Extensile Lateral Approach
Traditional L-shaped incision providing excellent exposure.
Sinus Tarsi Approach
Minimally invasive approach associated with:
- Lower wound complication rates
- Reduced soft tissue injury
- Equivalent functional outcomes in selected cases
Essex-Lopresti Percutaneous Technique
Tongue-type fractures may be treated with:
- Percutaneous reduction
- Axial pin fixation
- Cannulated screw fixation
This technique minimizes soft tissue complications.
Postoperative Rehabilitation
Postoperative management typically includes:
- Early subtalar ROM exercises
- Non-weight bearing for 8–12 weeks
- Progressive weight bearing by 3 months
Complications of Calcaneus Fractures
Complications are common and may occur after both operative and non-operative treatment.
Early Complications
- Wound dehiscence
- Skin necrosis
- Infection
- Compartment syndrome
Late Complications
- Subtalar arthritis
- Chronic heel pain
- Heel widening
- Peroneal tendon impingement
- Loss of subtalar motion
- Sural nerve injury
- Complex regional pain syndrome (CRPS)
Prognosis
Calcaneus fractures can be severely disabling injuries. Outcomes depend on:
- Degree of articular comminution
- Accuracy of reduction
- Soft tissue condition
- Patient comorbidities
- Smoking status
- Occupational demands
Patients with severe intra-articular fractures may ultimately require:
- Subtalar arthrodesis
- Triple arthrodesis
- Chronic pain management
Key Points
- Calcaneus fractures are the most common tarsal fractures.
- Most occur after falls from height.
- CT scan is essential for classification and surgical planning.
- Sanders classification is the most widely used CT-based system.
- Böhler angle reduction suggests posterior facet collapse.
- Treatment remains controversial for displaced intra-articular fractures.
- Complications such as subtalar arthritis and chronic pain are common.
References & More
- ESSEX-LOPRESTI P. The mechanism, reduction technique, and results in fractures of the os calcis. Br J Surg. 1952 Mar;39(157):395-419. doi: 10.1002/bjs.18003915704. PMID: 14925322. Pubmed
- Sanders R. Displaced intra-articular fractures of the calcaneus. J Bone Joint Surg Am. 2000 Feb;82(2):225-50. doi: 10.2106/00004623-200002000-00009. PMID: 10682732. Pubmed
- Buckley R, Tough S, McCormack R, Pate G, Leighton R, Petrie D, Galpin R. Operative compared with nonoperative treatment of displaced intra-articular calcaneal fractures: a prospective, randomized, controlled multicenter trial. J Bone Joint Surg Am. 2002 Oct;84(10):1733-44. doi: 10.2106/00004623-200210000-00001. PMID: 12377902. Pubmed
- Sanders R, Fortin P, Pasquale T, et al. Operative treatment in 120 displaced intra-articular calcaneal fractures: Results using a prognostic computed tomography scan classification. Clinical Orthopaedics and Related Research 1993;290:87–95
- Mercer’s Textbook of Orthopaedics and Trauma, Tenth edition.
