Objective: To quantitate the iatrogenic injury associated with deep plantar metatarsal fasciotomy performed with Metzenbaum scissors compared with a Y-shaped fasciotome. Study design: Experimental ex vivo surgical study. Study population: Cadaveric hind limbs (n = 20) from 10 sound thoroughbred racehorses. Methods: A plantar metatarsal fasciotomy was performed, extending from the proximal extent of the deep metatarsal fascia, distally. Hind limbs were randomly assigned to 2 groups, undergoing fasciotomy with straight Metzenbaum scissors (n = 10) or a Y-shaped fasciotome (n = 10). Magnetic resonance imaging was performed before and after surgery to identify the maximal depth of any iatrogenic trauma. Gross examination of the surgical site included measuring the length of the incision in the deep metatarsal fascia and localizing iatrogenic trauma sustained by the plantar aspect of the proximal suspensory ligament (PSL) during the procedure. Results: Iatrogenic injury to the PSL was identified in 6 of 10 and 9 of 10 specimens prepared with the fasciotome and Metzenbaum scissors, respectively (P = .03), and was most commonly located in the distal third of the fascial incision. Differences between the length of incision (P = .02) and the maximal depth of signal (P = .03) for incisions created with Metzenbaum scissors or a fasciotome were identified. Conclusion: The use of a fasciotome resulted in longer fascial incisions and less severe iatrogenic trauma to the PSL compared with using Metzenbaum scissors. Clinical significance: A Y-shaped fasciotome may be the preferred surgical instrument for successful desmopathy of the PSL fasciotomy because a greater release of compartmental pressure is possible through a longer incision with minimal iatrogenic trauma to the underlying PSL.

A quarter crack is a defect of the hoof wall that is caused by a combination of factors that affect the quality of the hoof horn. To date, no peer-reviewed studies have described the incidence of quarter cracks in Thoroughbred racehorses during training. Further, there is limited information regarding the clinical presentation and racing performance following a quarter crack. Therefore, the objectives of the current study were to describe the incidence, clinical presentation and outcome of quarter cracks sustained by horses in racing and training at the Hong Kong Jockey Club. Horses with quarter cracks that required attention from a farrier and/or veterinarian were identified using farrier and veterinary clinical records. Data were described, including the affected foot, presence of lameness, treatment, reoccurrence and racing data for case and control horses. There was no significant difference between case and control horses for total career length, and the total number of starts, wins and places. Seventy-four horses experienced at least one quarter crack during the study period, for a total of 114 quarter cracks. Half of the horses experiencing a quarter crack were not lame on presentation. Most quarter cracks occurred in the right fore (n = 56/102; 54.9%) and in a medial position (n = 90/102; 88.2%). Horses returned to racing a median of 50 days after the first treatment, for a median of 18 starts. Six horses retired due to the occurrence of a quarter crack. Although the incidence of quarter cracks in racehorses is low and the majority of horses returned to a racing career comparable to unaffected horses, the reoccurrence rate is high, putting an emphasis on ongoing hoof management and farrier care to help prevent the reoccurrence.