Background There are two cruciate ligaments in the knee (or ‘stifle’ as we call it in dogs). Cruciate disease (affecting the cranial -or anterior- cruciate ligament) is one of the most common orthopaedic conditions seen in dogs. In people cruciate ligament (or ‘ACL’) ruptures are typically seen as acute sporting injuries, in footballers and skiers for example. In dogs it is a little different. In most dogs the condition is a more chronic degenerative condition. The ligament degenerates and gets weaker with time and at some point will start to tear. The signs associated with the initial stages of the condition can be subtle and may be missed –signs such as stiffness on rising from rest and mild, occasional lameness. As the ligament continues to tear the signs may become more obvious but it is not uncommon for owners to first realise their dog has a problem when the already weakened ligament finally tears completely, often during relatively normal activity. At this stage the stifle will be unstable –the two bones of the stifle (the tibia and femur) will rock back and forth during walking. This instability will often lead to the menisci (cartilage ‘shock absorbers’ of the knee) being torn, which can cause significant lameness and discomfort unless treated appropriately.
Diagnosis The diagnosis is often made on palpation/manipulation of the stifle, although in some dogs this may require sedation. X-rays will show signs of osteoarthritis (OA or ‘arthritis’). Early cases may be less easy to diagnose, sometimes requiring exploratory surgery/arthroscopy to visually examine the cruciate ligament.
Treatment Some small dogs (less than 15kg) may do well with a period of rest and antiinflammatories alone, although surgery is generally considered to offer a quicker and more reliable recovery. Larger dogs are less likely to do well without surgery and if left develop severe degenerative joint disease and so surgery is always advised. Surgery involves examination of the menisci, so that any torn pieces can be removed, and stabilisation of the joint. Numerous stabilisation techniques have been described. A restraining suture can be placed around the outside of the joint to try to replicate the function of the torn ligament (known as extracapsular or lateral retinacular suture stabilisation) but these sutures frequently stretch or break, with recurrent instability. This technique is the cheapest and works best on small light weight dogs At Parklands Veterinary Group we recommend Tibial Tuberosity Advancement (TTA) -this technique changes the geometry of the tibia to counteract the forces that are responsible for the instability. This techniques is robust, reliable and provides a consistently early and good return to function... indeed many dogs are weight bearing on the leg the day following surgery but as this is an advanced surgery reconstructing the forces going through the knee using titanium implants, it is much more expensive than the lateral suture technique. At Parklands , we have performed hundreds of these procedures and the risk of complications is very low. Recent evidence confirms that TTA surgery returns dogs to better limb function than suture stabilisation in the short and medium term.
We are pleased to take 1st and second opinion cases on cruciate disease management and surgery
Extracapsular suture – Key Points:
- When performed by an experienced surgeon this can be a reliable technique for small/medium dogs, but there is a risk of suture stretching/failure which can result in recurrent instability
- Postoperative function is enhanced through the use of a minimally invasive arthrotomy, isometric suture placement & use of high stiffness materials
- Evidence shows that dogs do not return to as good limb function as with TTA
TTA– Key Points:
- These are very reliable and safe techniques, even in very active or large/giant breeds of dog, when performed by experienced surgeons
- Early return to limb use is expected (usually weight-bearing next day)
- Greater cost than suture stabilisation due to the complexity of the surgery and implant costs
- We offer TTA surgery and will advise the most appropriate surgery for your dog after assessment of his or her condition and x-rays
- These are complex surgeries and in inexperienced hands complications can be serious.