Introduction

Partial tarsal arthrodesis (ParTA) is a recognised salvage procedure for intertarsal subluxation, tarsometatarsal subluxation and talocalcaneal luxation, and is indicated where ligamentous damage is deemed irreparable or profound fracture disruption has occurred. Repair of collateral tarsal ligaments has been described; however, injuries disrupting the plantar ligament complex usually necessitate arthrodesis to restore stability. Cartilage debridement, bone graft application and rigid fixation are prerequisites for successful arthrodesis. Stabilisation of the calcaneoquartal-talocentral and tarsometatarsal joints using laterally applied bone plates has been described but circumstances such as extensive soft tissue loss and infection may preclude their use. This case series describes the use of a type 1 linear ESF with a 'tied in' intramedullary calcaneal pin in 9 dogs.

Materials and Methods

A retrospective review of all dogs that underwent ParTA with a type 1 ESF with 'tied-in' intramedullary calcaneal pin operated by a single surgeon, between 1995 and 2005, was performed. In all cases the frame was placed laterally and the calcaneal pin passed into the third or fourth metatarsal and respective fourth tarsal bone. The metatarsal chosen was that which facilitated limb alignment best. Inclusion criteria were availability of clinical records and radiographic plus clinical follow-up to at least 12 weeks post-operatively. Data recorded included signalment, indication for surgery, type of frame applied, post-operative care, staging of frame removal, follow-up results, and complications encountered (major versus minor). Radiographs were interrogated for arthrodesis progression and construct complications.

Results

Nine dogs met the inclusion criteria, 2 females and 7 males. Mean age was 91 ± 37 months, weight 17.1 ± 8.4 kg. Indications for surgery included various ligamentous injuries in conjunction with calcaneoquartal, proximal intertarsal, or tarsometatarsal luxation. 5 frames were de-staged prior to removal, 4 frames were removed in their entirety upon radiographic evidence of arthrodesis. Complications encountered included superficial pin tract infections which were all deemed minor as they resolved with antibiotic therapy and implant removal. One case fractured post frame removal due to lack of owner compliance with post-operative instruction. The complications were not significantly associated with age, weight, sex or injury sustained.

Conclusion

Partial tarsal arthrodesis can be successfully achieved using external skeletal fixation with the use of a 'tied in' intra-medullary calcaneal pin, and provides an alternative fixation strategy, especially when internal fixation may be suboptimal or precluded by injury type.