The inferior check ligament (ICL) is located at the back of front and rear cannon in all horses and ponies. The ligament originates at the back of the knee and travels lower down the limb before attaching with the deep digital flexor tendon (DDFT) halfway down the cannon. It is situated between the suspensory ligament and the flexor tendons. The ICL is also known as the accessory ligament of the deep digital flexor tendon (ALDDFT).
Strains of the check ligament occur most frequently in the forelimb and in older animals (over 10 years old). Although the horse may have been performing in some form of athletic work such as Show Jumping or Eventing at the time of the injury many horses can injury the ligament in the field. It has been suggested that there is an age-related degeneration of the check ligament as alterations in collagen affect the overall tensile strength of the structure.
Injuries to the check ligament are often acute and present as a sudden onset lameness. There is usually heat, pain and swelling around the tendons in the upper cannon area.
Chronic cases can also occur and typically present as repeated strains to the ligament over a period of time. Some chronic cases can remain permanently lame and develop postural changes to the limb, usually as a result of adhesion formation. Veterinary attention should be sought in both cases and an ultrasound is recommended to determine the degree and extend of ligament damage.
Treatment in the acute stages aims to reduce inflammation and include cold water hydrotherapy and/or ice packs which should be applied to the area at least twice a day. Between treatments a supportive bandage should placed on the lower limb. Non-steroidal anti-inflammatory medication should be provided to alleviate pain and reduce swelling. The horse should be also placed on complete box rest for a minimum of a week and then a controlled exercise programme can be introduced. Injections of a variety of products into the damaged areas can be undertaken, usually between 2 to 4 weeks post injury.
Ligaments are slow to heal and a full recovery can take 6 months or longer. Repeated ultrasound scans throughout the recovery period can help gauge the healing process and provide prognosis for any return to work. Return to full athletic work is guarded in check ligament strains with a high percentage of cases suffering repeat injuries. This could be related to the finding there is an age related degeneration in the ligament.