SLR - May 2014 - David J. Vieweger
Reference: Zhang T, Su Y, Chen W, Zhang Q, Wu Z, Zhang Y. Displaced Intra-Articular Calcaneal Fractures Treated in a Minimally Invasive Fashion: Longitudinal Approach Versus Sinus Tarsi Approach. The Journal of Bone and Joint Surgery. 2014 Feb; 96(4): 302-9.
Scientific Literature Review
Reviewed By: David J. Vieweger, DPM
Residency Program: Medstar Washington Hospital Center
Podiatric Relevance: With wound complication rates as high as 30 percent, the common L-shaped extensile lateral approach for repair of intra-articular calcaneal fractures can be quite problematic. Innovative surgical techniques utilizing minimally invasive approaches have been developed to reduce operative time, decrease wound complications and lead to a quicker return to activity. However, controversy exists regarding the optimal surgical approach for accurate reduction of such fractures. The purpose of this study was to compare the clinical outcomes of the sinus tarsi approach with those of the minimally invasive longitudinal approach for repair of intra-articular calcaneal fractures.
Methods: This prospective study included patients admitted from September 2009 through April 2010 for displaced intra-articular calcaneal fractures. Patients were randomly assigned to two groups and had their fracture repaired through either the sinus tarsi approach (STA) or the minimally invasive longitudinal approach (MILA). Inclusion criteria included age of eighteen years or older with no polytrauma of the ipsilateral lower limb. Patients who had severe medical ailments were excluded. All patients received pre-operative radiographic imaging including a CT scan from which their fracture was classified by the Sanders classification. The MILA was performed through a 3.5 cm longitudinal incision over the posterior part of the lateral hindfoot along the lateral border of the Achilles tendon. The STA was performed through a horizontal incision along the sinus tarsi. Both techniques utilized compressive bolts and an anatomic plate to restore Böhler’s angle and the posterior articular facet.
Post-operative CT scans were taken and the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score was utilized to assess functional outcomes. Partial-weight bearing began at four weeks after the operation with full weight-bearing generally started at three months post-operatively. Hardware was routinely removed at twelve months. Statistical analysis was then performed comparing functional outcomes, radiographic correction of fractures, and complications.
Results: One hundred thirty patients (114 men) were followed for an average of twenty-seven months, with sixty-three patients treated with the MILA and sixty-seven patients treated by the STA. The mean age was 41.7 years and 39.8 years in the STA and MILA groups, respectively. There was no significant difference between the two groups in terms of sex, age during injury, fracture classification and time from initial injury to surgery. The average operative time was 45.9 minutes in the MILA group and 61.9 minutes in the STA group, a significant difference. The soft-tissue complication rate was 10.1 percent in the MILA group and 18.1 percent in the STA group, also a significant difference. The average pre-operative Böhler angle was -1.3 degrees in the MILA group and 1.9 degrees in the STA group, with an average immediate postoperative Böhler angle of 28.8 degrees and 26.7 degrees in the MILA and STA groups, respectively. For patients with Sanders type-II and III fractures, there was no significant difference in articular restoration between the two groups. However, patients with type-IV fractures in the STA group had better posterior facet restoration than those in the MILA group. The mean overall AOFAS score was 86.2 in the MILA group and 88.8 in the STA group with patients in the STA group having better outcomes in all four subjective categories. Patients with Sanders type-II or III fractures in both groups had similar function outcomes. However, patients with Sanders type-IV fractures had a good to excellent rate in the STA group that was significantly higher (56.3 percent versus 14.3 percent).
Conclusions: With an extensive lateral incision wrought with wound healing complications, both the minimally invasive longitudinal approach and the sinus tarsi approach may provide an excellent alternative method of repair of intra-articular calcaneal fractures. However, the MILA significantly reduces operative time and wound-healing complications compared to the STA group. For Sanders type-IV fractures, the STA yields a better reduction of the articular surface than the MILA. Both approaches allowed for relatively quick return to weight-bearing and sport activities with little evidence of subtalar arthritis. This study provides two minimally invasive procedures to achieve anatomical reduction of intra-articular calcaneal fractures with few complications and excellent functional outcomes.