Club foot!!

The radiograph below is from a weanling colt with a severe case of a "club foot". Figure 1 is the affected foot and figure 2 is the normal foot. X-ray vision was not necessary in this case to confirm the diagnosis due to the classic distortion of the hoof capsule. Club feet in foals develop from tendon contracture or secondary to accelerated skeleton growth. As the leg bones grow in length the soft tissue structures (tendons and ligaments) cannot keep up with the rate of growth resulting in contracture of the joint spaces. In the case of a "club foot" it is the coffin joint or DIP joint that is contracted and results in abnormal hoof growth.

Figure 1

Figure 2

The yellow line below corresponds to the alignment of the short pastern bone and the coffin bone. In Figure 3, the alignment is normal. However in Figure 4 the dorsal surface of the coffin bone is not aligned with the short pastern bone. The letter "A" in figure 4 corresponds to the angle of contracture. The contracture occurs in part due to the strong pull of the deep digital flexor tendon that attaches to the bottom of the coffin bone. As the leg bones lengthen and the flexor tendons do not keep up with the growth rate, the coffin bone is pulled resulting in contracture of the joint.

Figure 3

Figure 4

Treatment of this condition in young horses varies and includes early weaning, reduced caloric intake,  repeated injections of oxytetracycline to relax the tendons, corrective trimming/shoeing, and surgical transection of the distal check ligament. In my clinical experience, many foals with mild contracture respond well to the oxytetracycline and corrective trimming protocol. However, more advanced cases such as this colt require surgical intervention. The distal check ligament attaches to the deep digital flexor tendon and essentially keeps it in "check". By cutting the ligament, there is some release of the pull by the deep digital flexor tendon on the coffin bone. This surgical procedure can be performed in a stall-side setting, in a standing patient. Once it is determined that surgery is indicated, the sooner the better!  The colt in this case was treated with oxytetracycline and corrective trimming for 2 months with minimal improvement. When he was 6 months old, the distal check ligament of the affected limb was transected. Figure 5 is the "club foot" 45 days post surgery, note the corrected alignment of the pastern and coffin bones. The colt's lameness resolved.  This case highlights the importance of early documentation with radiographs and early intervention to correct the "club foot".

Figure 5