Hock and Stifle OCD

Osteo-chondrosis diseccans (OCD) is a common abnormality of joints affecting young horses. The stifle and hock joints are most frequently affected, the signs including swelling of the joint (Figures 1 and 2), variable lameness, stiffness or gait abnormalities.

Figures 1 and 2 show fluid build up in the stifle and hock joints respectively, of two young horses with OCD. The case in Figure 1 was also quite markedly lame. After removing the large OCD fragment the horse went on to have a normal working life.

The dressage horse in Figure 2 developed a moderate joint filling in the hock and became increasingly reluctant to undertake to certain ridden exercise whilst training in the manege, although there was no evidence of lameness.

OCD involves the development of a fragment of cartilage with or without underlying bone which becomes partially or completely detached from the underlying bone, forming a loose flap or irregular surface in the joint (Figure 3). If left untreated, the inflammation caused by an OCD fragment can stimulate the development of arthritis within the joint.

Treatment involves surgical removal of the fragment using keyhole techniques (arthroscopy) which we undertake at our clinic in the equine operating theatre under general anaesthesia. Surgical treatment is very successful at resolving the problem in the vast majority of cases.