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Cranial cruciate ligament tears are the most common orthopaedic injury in people (ACL) and in dogs (CCL).  The cranial cruciate ligament sits inside the knee joint and stops the shin bone (tibia) sliding forward in relation to the thigh bone (femur).  


When the ligament tears there is a cranial drawer (forwards and backwards sliding) between these bones.  It is this movement which causes dogs pain and persistent limping.  The degree of movement is related to the amount of tearing of the ligament.  Surgery to stabilise the knee will have been performed and the structures inside the knee (cranial cruciate ligament, caudal cruciate ligament, lateral and medial meniscus, and the articular cartilage) will be examined and "cleaned-up" if found to be damaged at the time.

Approximately 30% of patients that present for tears of the cranial cruciate ligament will also have an injury to the shock-absorbers inside the knee (lateral and medial meniscus).  If the meniscus are found to be injured at the time of surgery then the damaged portion is removed, whilst in patients that do not have a tears the meniscus is left intact as it is important to joint function.  

There is however an approximately 10% risk of an injury to the meniscus at a later date.  This generally appears as a patient that has recovered well from the initial knee surgery, and then starts to limp on the leg generally 1-6 months later.  Should this occur then re-examination would be advised, and this may be treated by either arthroscopic or open surgical removal of the damaged meniscus, with quick recoveries and outcomes to pre-injury levels expected .

Osteoarthritis will progress but the rate following surgery shouuld be slowed, if cmpared to patients that do not have surgery.  Management of longer-term osteoarthritis should be focused on body weight control, joint supplementation (fish oils, glucosamine/chondroitin, pentosan polysulphate injection), anti-inflammatories as required, and moderation of exercise.

Complications rates fortunately are very low, with the most common complications being infection (2-4%), usually only requiring antibiotics additional to the ones dispensed at the time of surgery.