Wednesday, November 11, 2009

Calcaneal Fractures

CALCANEUM fractures
Mechanism of Injury: fall from height or motor vehicle accident

Classification:
a. Extra Articular Fractures
• Anterior process fractures
• Tuberosity fractures
• Medial process fractures
• Sustentacular fractures
• Body fractures not involving the subtalar articulation

b. Intra Articular Fractures (Essex Lopresti Classification)
Intra- articular fractures involve the subtalar joint.

They have primary and secondary fracture lines. Intra articular fractures are more common (75%)

Primary Fracture Line Producing two main fragments:
 Sustentacular (anteromedial) and the tuberosity (posterolateral) fragments.
 The anteromedial sustentacular fragment is also called the ‘constant fragment‘ because of its resistance to significant displacements.
 The anteromedial fragment consists of part of the posterior facet, anterior process, middle and anterior facets, supported by the sustentaculum tali.
 The posterolateral fragment consists of the tuberosity and lateral wall along with a variable portion of the posterior facet.

Secondary Fracture Line
• Tongue fracture. Secondary fracture line appears beneath the facet and exits posteriorly. The relationship of the lateral posterior facet and the superior aspect of the tuberosity remain intact.

• Joint depression fracture: Secondary fracture line exits just behind the posterior facet. Joint depression fractures are those in which the secondary fracture line separates the lateral posterior facet from the body and tuberosity of the calcaneus.

Sanders Classification
Describes comminution and displacement of the posterior facet by computed tomography.
CT scan is essential if surgical treatment is being planned.

• Type I: All Nondisplaced 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 in which a centrally depressed fragment exists; subtypes IIIAB, IIIAC, IIIBC
• Type IV: Four-part articular fractures; highly comminuted

 Bohler’s tuber joint angle :( 25 to 40 degree normal). Decreased in intra-articular calcaneal fractures.

 Crucial angle of Gissane: Angle formed between the posterior facet and the anterior facet. Normal angle is 110 to 130°. Increased in intra-articular calcaneal fractures.



 Harris axial view is used to assess varus or Valgus position and width of the heel.

 Brodén view, obtained by internally rotating the leg 40 degrees with the ankle in neutral, then angling the beam 10 to 15 degrees cephalad, helps to evaluate congruency of the posterior facet

Treatment
• Extra-articular fractures of the calcaneum can be treated conservatively.
Displaced tuberosity avulsion fracture, which serves as the attachment of the tendo calcaneus should be internally fixed with a screw to restore the power of the tendo calcaneus and prevent a wide heel with the ensuing difficulties of shoe-fitting
• Intra-articular fractures:
‣ Should be treated with ORIF with plates and screws (Reconstruction plate) in order to reconstruct the articular surface.
‣ Axial fixation using the Gissane spike has been popularized by Essex Lopressti

‣ Patients with increasing physiological age, male gender, tobacco use, a pending worker’s compensation claim, heavy laborers, bilateral injuries and increasing comminution of posterior facet may not have significant improvement in function with surgery as compared to nonsurgical treatment(1,2)

‣ Anatomic surgical reduction of posterior facet results in improved outcomes compared with those achieved reduction with residual steps, gaps or comminution.

Surgical Pearls:
• Reconstruction of the calcaneus:
 Surgical reconstruction maybe delayed for 7 to 10 days for optimization of soft tissue status
 Performed through a lateral “L” incision, with the vertical limb just posterior to the midpoint between lateral border of Achilles tendon and posterior aspect of fibula, posterior to sural nerve.
 The lateral border of the calcaneus is exposed subperiosteally by elevating a full thickness flap. Peroneal tendons, sural nerve and calcaneofibular ligament are reflected en masse in the flap.
 Vascularity of flap is based on peroneal artery blood supply which remains protected within substance of flap
 Reduction typically proceeds from anteromedial to posterolateral, effectively decompressing central portion of calcaneus to allow accurate reduction of posterior facet fragments
 A pin is placed in the posterior fragment to improve exposure of the fracture and to facilitate reduction.
 A plate (reconstruction plates, precontoured periarticular multiple limbed plates or LCP) is placed laterally after the fracture has been reduced, and fixation is provided by placing screws into a stable fragment, commonly the sustentaculum tali.
 Principles of reconstruction include restoration of calcaneal height (Bohler’s angle), heel width (as in axial view), posterior facet alignment, and anatomic realignment of the three superior facets to each other.
 The sural nerve is preserved and the peroneal tendons reflected ‘en masse’ to expose the sub-talar joint.
 Large Bony defects may require bone grafting.
 The incision is closed primarily, using a two layered closure. There should be a deep interrupted absorbable periosteal suture followed by a separate nylon modified Allgower-Donati flap stitch to minimise tension along the skin incision.
 posterior splint is applied

Complications of Calcaneal Fractures:
• Wound Necrosis, Dehiscence, and Infection: Carefully retracting the soft tissues and maintaining a full-thickness flap during open reduction are crucial.
• Lateral fibular impingement: This is treated by lateral decompres¬sion.
• Post traumatic arthrosis of subtalar joint: Treated by subtalar arthrodesis.

Open calcaneal fractures:
• 5- 10% calcaneal fractures are open
• Most of the wounds occur in the medial aspect of foot
• They are prone for wound complications like osteomyelitis, poor functional outcome and amputation
• Gustilo I and II open fractures on medial side can be treated with ORIF with results similar to closed fracture.
• With more extensive soft tissue compromise or type II non medial wounds, external fixation and/or percutaneous screw fixation should be considered.
• Alternative treatment methods for open calcaneal fractures like percutaneous limited approaches, arthroscopy assisted techniques and ring fixators.


Further Reading:
1. Buckley RE, Tough S. Displaced intra-articular calcaneal fractures. J Am Acad Orthop Surg 2004;12:172–178
2. Buckley R, Tough S, McCormack R et al.. Operative compared with nonoperative management of displaced intraarticular fractures. A prospective RCT. JBJS 2003;84-A, 1733-1744

1 comment:

  1. The right time of surgery for fracture calcaneum is when the "wrinkle sign" appears i.e. when you dorsiflex the ankle, wrinkles should be present at the dorsum of ankle.
    Also see the video for ORIF calcaneum at http://www.youtube.com/watch?v=gngTOOFmgJM

    ReplyDelete