Return to Athletic Activity of a Shetland Pony Mare with Coxofemoral Luxation Treated by Femoral Head Ostectomy

TL;DR

A Shetland pony mare with a hip joint dislocation and patellar issue successfully returned to athletic activities after a surgical procedure called femoral head ostectomy.

Contribution

Demonstrates successful athletic recovery in a small equid after femoral head ostectomy for chronic hip luxation, defying typical guarded prognosis.

Findings

The mare resumed riding and schooling activities 18 months post-surgery.

Five years post-surgery, the mare showed no lameness or discomfort.

The procedure suggests potential for soundness in small equids weighing up to 180 kg.

Abstract

Coxofemoral joint luxation is an uncommon condition in horses but occurs more frequently in ponies, miniature horses, and foals. The primary cause is generally trauma. Upward fixation of the patella frequently accompanies coxofemoral joint luxation in ponies and can present either as a primary condition or as a secondary consequence of the luxation. Clinical signs include varying degrees of lameness, limb shortening, and outward rotation of the stifle and toe. Two treatment options are available: closed reduction and open reduction. The first one is recommended only for cases with a duration of up to 36 h. In the case of reluxation or in chronic cases, open reduction combined with a joint stabilization technique provides a higher likelihood of success. Femoral head ostectomy is regarded as a salvage procedure and is performed when neither closed nor open reduction is feasible. Horses treated with a femoral head ostectomy are typically designated for pasture, for breeding, or as pets. In the present case, we treated a chronic coxofemoral joint luxation, with concomitant permanent upward fixation of the patella, with a femoral head ostectomy without performing a greater trochanter osteotomy. The successful outcome, with a return to athletic activities despite the guarded prognosis, is confirmed through a 5-year follow-up.

Background: Femoral head ostectomy is considered a salvage procedure in the treatment of chronic coxofemoral joint luxation in small equids. Permanent lameness of varying degrees, largely depending on the animal’s weight, and potential contralateral limb deformity may occur. The purpose of this study was to report the outcome of a small equid that, despite undergoing a femoral head ostectomy for a chronic coxofemoral joint luxation, was able to return to being ridden by children and to athletic activities. Methods: An 8-year-old Shetland pony mare (180 kg) was presented for a chronic right hind limb lameness (5/5 AAEP grading score) of 12-days duration caused by a craniodorsal coxofemoral joint luxation and permanent upward fixation of the right patella. A femoral head and neck ostectomy was performed concomitant with desmotomy of the medial patellar ligament. Results: Eighteen months after surgery, the mare began being ridden by children and was used for schooling purposes. Five years post-surgery, she continued her work activities with no apparent signs of lameness or discomfort. Conclusions: Femoral head ostectomy following chronic coxofemoral joint luxation can result in a favorable outcome, with equids weighing up to 180 kg potentially regaining soundness and resuming athletic activities.

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