Talocalcaneal coalitions can be difficult to detect on plain radiographs, despite obvious clinical findings. The purpose of this study is two-fold: (1) to delineate the benefits of thin-cut computed tomography (CT) and 3D reconstructions and (2) to develop a classification scheme for talocalcaneal coalitions that will provide valuable information for surgical planning. From 2005 to 2009, 54 feet (35 patients) with a talocalcaneal coalition were evaluated with thin-cut (1 mm) CT, using multi-planar 2D and 3D reconstructions. The talocalcaneal coalitions were classified into five types based on the cartilaginous or bony nature, location, and facet joint orientation. Bilateral coalitions were found in 22/35 patients. Types I and II were fibrocartilaginous coalitions, which was the most common type, comprising 40.7 and 16.7% of the coalitions, respectively. Of the patients, 14.8% had a shingled Type III coalition, while 11.1% of the feet examined had a complete bony coalition (Type IV). Small peripheral posterior bony coalitions (Type V), which are heretofore not described, were found in 16.7% of feet. CT scans can provide valuable information regarding the bony or cartilaginous nature of coalitions, as well as the facet orientation, which is helpful in diagnosis and treatment. In this study, the 2D and 3D reconstructions revealed previously unreported peripheral posterior bony coalitions (Type V), as well as coalitions that are in the same plane as the standard CT cuts or Harris view radiographs (Type I). The CT scan also improved the crucial pre-operative planning of the resection in the more complex vertical and combined horizontal and vertical fibrocartilaginous coalitions (Type I and II). Additionally, the complete bony coalitions (Type IV) can be sized accurately, which is helpful in decision-making on the resectability of the coalition.

Background

The ligamentum teres (LT) is believed to have a number of functions, including a role in hip stability, nociception, proprioception, vascular supply to the femoral head, and synovial fluid circulation. The LT is often excised in the process of performing a medial open reduction (MOR) of the hip. We sought to conduct a retrospective review of hips undergoing a MOR for dislocated infantile developmental dysplasia of the hip (DDH) to compare clinical and radiographic outcomes for patients with and without LT reconstruction.

Methods

We performed a retrospective review of 38 hips treated with MOR with or without LT reconstruction with minimum two-year follow-up. Radiographic outcomes were determined using the Severin score. Information regarding avascular necrosis (AVN), concomitant surgical procedures, repeat dislocation, subsequent surgery, limp, pain, and range of motion symmetry was recorded.

Results

Eighteen hips that underwent MOR with LT reconstruction were compared to 20 hips that underwent MOR without LT reconstruction. Mean follow up for this cohort was 70.1 months (median: 61.8; Range: 24.2 to 182.2 months). The group with LT reconstruction had an 11% rate of AVN, the group without LT reconstruction had a 15% rate of AVN (p=1.0) No hips in either group re-dislocated or had pain at final follow up. Two hips (5%) had a limp at most recent follow up, all were in the group that did not receive a LT reconstruction (p=0.488). Three hips (17%) in the LT reconstruction group and one hip (5%) in the other group had asymmetrical hip range of motion at final follow up (p=0.328).

Conclusion

This study offers preliminary data to suggest that ligamentum teres reconstruction is a safe procedure that can minimize the risk for subluxation or re-dislocation that can occur within the post reduction hip spica cast. Although in this study, the patients who did not have LT reconstruction had a similar re-dislocation rate, we believe that ligamentum teres preservation is a useful adjunct to medial open reduction, especially in centers that may only treat occasional cases or have less experience in applying an excellent hip spica cast.Level of Evidence: III.