Plus-Hex CLINICAL
Introduction
Rupture of the cranial cruciate ligament( CCL) is one of the most common conditions affecting dogs [ 1 – 3 ]. It often occurs as a result of progressive degeneration, which can be influenced by the dog ' s breed, sex and age, as well as the conformation of the stifle( knee) joint. Trauma can also cause the CCL to rupture; this will normally occur when the dog is exercising. Degeneration of or trauma to the CCL can cause a partial or complete rupture of the ligament. It is sometimes referred to as CCL disease rather than rupture [ 4 ].
A ruptured CCL can be managed both conservatively and surgically, taking various factors into consideration. The age and current health status of the patient, the severity of the stifle instability and the cost of treatment can all influence the type of treatment that is provided. A CCL rupture is a painful and potentially debilitating injury that can decrease a dog ' s quality of life, so it is important that the treatment is tailored appropriately to each patient.
The stifle joint is held together by multiple ligaments – tough bands of fibrous tissue – that play a vital role in maintaining the stability of the joint( Figure 1). The CCL is one of the main ligaments; it joins the femur and tibia together so the knee can work as a hinge [ 3 ]. A healthy CCL‘ limits hyperextension of the stifle joint as well as internal rotation and cranial displacement of the tibia relative to the femur’ [ 5 ]. Consequently, when the CCL is ruptured, even partially, the joint will become unstable and the animal will experience pain [ 6 ].
Patient signalment
Species Breed Age Sex
Weight
Dog
Presentation
Springer spaniel 6 years Male, neutered 17.3 kg
The patient was referred to the veterinary hospital following a 3-week period of right pelvic limb lameness. The owner reported that no trauma had occurred and the patient was otherwise systemically healthy. The referring veterinary surgeon( VS) had prescribed a 5-day course of oral meloxicam and advised a 10-day period of rest. The patient showed small improvements in response to this treatment.
Patient assessment
A general examination was performed, which produced unremarkable results, and a gait assessment revealed almost no lameness. On orthopaedic examination it was noted that the patient had a right medial buttress on the medial aspect of the stifle, with mild stifle effusion. A medial buttress is‘ palpable as an exaggerated bump extending across the medial aspect of the stifle joint’ [ 2 ]. In a healthy stifle joint, the patellar ligament should be palpable, so when this ligament cannot be palpated during the examination it indicates a build-up of fluid within the stifle joint, known as stifle effusion.
A cranial drawer test was performed by the VS to examine the stability of the stifle joint while the patient was in lateral recumbency. This test involves placing a thumb on the caudal aspect of the femoral condylar region with the index finger on the patella, and the other thumb on the head of the fibula with the index finger on the tibial crest. While gently moving the thumbs and index fingers the stability of the joint is monitored( Figure 2).
Figure 1. The stifle( knee) joint, with the CCL coloured purple [ 6 ]. Figure 2. The cranial drawer test [ 6 ].
Volume 40( 3) • June 2025
49