Single-incision percutaneous drilling technique to achieve hemiepiphysiodesis of the distal metacarpus in foals with metacarpophalangeal varus deformities.

OBJECTIVE

To describe a drilling technique for hemiepiphysiodesis of the distal lateral metacarpal physis and report the outcome of treated foals.

STUDY

DESIGN

Retrospective case series.

SAMPLE POPULATION: Eleven thoroughbred foals.

METHODS

While horses were under general anesthesia, the lateral aspect of the distal metacarpal physis was approached through a single small incision by using a power drill. The drill bit was placed at the level of the physis under radiographic guidance. A 4.5-mm drill bit was passed several times through the lateral growth plate to remove the cartilage in a fan-like pattern. Postoperative outcomes consisted of clinical assessment and farm manager/owner satisfaction. Cosmetics and radiographic appearance of the surgical site were assessed when the horses were yearlings.

RESULTS

The procedure was performed in 16 limbs of 11 thoroughbred foals with a median age of 113.5 days (range, 90-129). Median age at postoperative follow-up was 422 days (range, 366 to 452). The procedure stopped the progression of a metacarpophalangeal varus deformity in all the limbs treated, determined by visual clinical evaluation and farm manager's satisfaction with subjectively excellent radiographic images and cosmetic outcomes at yearling age.

CONCLUSION

Physis ablation was consistently achieved in these 11 foals with developing growth deformities of the distal metacarpus.

CLINICAL SIGNIFICANCE: This drilling technique may offer a minimally invasive, safe, and simple technique to manage distal limb conformation in foals without placement of implants. Additional quantitative data are required to assess its effectiveness relative to other options.