Introduction

Tarsal injuries commonly occur in cats and dogs, often as a result of motor vehicle accidents or falls from height. Studies report 66–78% of shearing injures affect the medial aspect of the pelvic limb. When primary repair is not possible, arthrodesis is indicated to alleviate joint pain and provide functional stability. There is however a paucity of literature on pantarsal arthrodesis of the feline hock with the existing literature reviewing canine pantarsal arthrodesis (PANTA). This case series describes the surgical technique according to the principles of 'minimally invasive plate osteosynthesis' (MIPO) with the application of a novel dorsal plate, without external coaptation, and reports clinical outcome.

Materials and Methods

A retrospective review of all cats treated with the novel dorsal PANTA plate by a single surgeon between 2008 and 2011 was performed. Inclusion criteria were availability of clinical and radiographic records plus clinical follow-up to at least 12 weeks postoperatively. Data recorded included signalment, indication for surgery, postoperative care, and complications encountered (major versus minor). Radiographs were interrogated for arthrodesis progression and implant complications.

The plate was applied utilising 3 portal incisions (tibial, tarsocrural and metatarsal). Cartilage debridement of the tarsocrural and proximal intertarsal joint surfaces was achieved. Tibio-calcaneal screw placement was performed in all cases. The metatarsal chosen for plate application (3 or 4) was that which best facilitated limb alignment. A soft, padded bandage was applied to control post-operative swelling. In no case was external coaptation employed.

Results

Eleven cats were treated for tarsal injuries following RTA (n = 7), fall from height (n = 1), fighting (n = 1), un-witnessed trauma (n = 1) and persistent lameness (n = 1). Breeds included DSH (n = 9), DLH (n = 1) and Maine Coon (n = 1). Mean age was 86 ± 45 months, weight 4.50 ± 0.92 kg. The only major complication encountered was wound breakdown (n = 1). Minor complications included extended post-operative swelling (n = 2), and screw loosening/bending (n = 2). Complications were not significantly associated with breed, age or weight of patient. All cases manifested radiographic signs of fusion within the expected 6–8 weeks.

Discussion

Dorsal plate application has been associated with an increased implant failure rate; we experienced no plate failures and our major complication rate was lower than comparable published canine data. The novel plate achieved arthrodesis, without the need for external coaptation, and plate design facilitated application by MIPO principles.