ABSTRACT: This article aims to give an understanding of the canine cruciate ligament and its relationship with the tibial plateau, and to provide guidance on nursing care following the repair of cranial cruciate ligament rupture.

Cranial cruciate ligament anatomy

The most common ligament repair required in small animal practice is to the cranial cruciate ligament (CrCL). This is an intracapsular ligament in the stifle, formed by two bands, namely the craniomedial (CrMB) and the caudolateral (CaLB). The CaLB is much thicker and is only used during extension, whilst the CrMB is the smaller of the two and is used when the stifle both extends and flexes.

The difference in strength between the bands creates a weak point within the joint architecture. The cranial cruciate ligament is the only ligament in the stifle to be structured in this way.

When the stifle flexes and rotates internally, the pull from the medial femoral condyle puts strain and pressure on the CrCL causing it to tear when under extreme force. Additionally the medial meniscus can be trapped within the articular surfaces and severed, thereby causing pain to the patient. The patency of the meniscus is always checked during surgery, and it is removed if necessary, in order to prevent chronic pain.

The tibial plateau

The anatomy of the stifle is such that in animals, the tibial plateau slopes caudally. The degree of this slope is currently considered to contribute to instability within the stifle. This results in the femoral condyles sitting towards the back of the joint, putting strain on the intracapsular ligaments. The caudal position of the condyles, combined with the movement of the stifle when excessive force is applied, can result in a rupture if degenerative changes have occurred within the CrCL.

A significant number of humans will rupture a cruciate ligament as a result of excessive force upon the ligament during exercise. Whilst this may also occur in dogs, it is not the most common way in which canine patients will damage their cruciates.

Current thinking is that the cruciate ligaments undergo gradual degeneration during the animal’s lifetime and that natural forces acting upon the joint contribute to its degeneration and ultimate rupture. The shape of the tibial plateau is a large factor in the direction of the resultant forces acting upon the joint, but other factors, including breed, do have a larger part to play.

Surgical techniques

There are several methods of repairing the stability of the stifle following CrCL rupture, with different approaches preferred by different surgeons (Figure 1).

Figure 1: A – Lateral FabeLLotibiaL Suture; B -TibiaL Wedge Osteotomy (see the 'wedge' that would be taken out of the tibia to Level the plateau);C – TripLe TibiaL Osteotomy

Depending on body size, reducing the angle of the tibial plateau is the usual goal for surgery, as the ligament itself cannot usually be repaired or replaced (Figure 2). This alters the biomechanics of the joint, erasing the need for the CrCL and can be achieved using different surgical techniques, such as triple tibial osteotomy (Figure 3), tibial plateau levelling osteotomy, tibial tuberosity advancement and the tibial wedge osteotomy.

Figure 2: The tibial plateau after surgery

Figure 3: The surgeon placing the plate over the tibia before securing it in place

These are all periarticular techniques and aid in supporting the stifle so the joint capsule can thicken. There are other techniques that do not require the adjustment of the TP, these include the extracapsular technique the lateral fabellotibial suture and the intracapsular ‘over the top’ technique.

Patient care

Preoperatively it is normal practice to administer a premedicant, such as acepromazine, an opioid, and a dose of an NSAID. The patient is placed on intravenous isotonic crystalloid fluid in order to support and balance the circulatory system and prevent it from being compromised by blood loss during the operation. This is usually given at a surgical rate of 10ml/kg/hr.

It is advisable to include a dose of ketamine with the fluids as this is an effective somatic and visceral analgesic. The combination of the analgesics when given before the operation prevent pain wind up and stop the central nervous system from becoming over sensitive towards pain. The analgesics act on the N-methyl-D-aspartate (NMDA) receptor found in the spinal cord and if given before a painful procedure can have significant analgesic effect, thus making the patient more comfortable post-operatively.

Once anaesthetised, the patient is usually placed in ventro-dorsal recumbency with the affected limb suspended and scrubbed in preparation for the medial incision that will be made. The limb should be clipped from the hock around the circumference of the proximal limb up to the area of the lumbo-sacral spine. When the limb is clipped, place a secure open weave bandage, followed by a conforming bandage, around the hock and tarsus (Figure 4).

Figure 4: The patient immediately before being scrubbed for surgery.

Perioperatively, the surgeon will request cold fluid irrigation to minimise the chance of thermal necrosis from the oscillating saw and the drill. This requires a steady hand to apply a constant stream of sterile saline to the tibia. The entire procedure takes approximately 90 minutes to complete depending on the choice of method; therefore, the patient’s temperature will require monitoring and the application of a heat source, such as heat pads, should be used to maintain core body temperature.

Postoperatively the patient should be placed in lateral recumbency, with the affected limb uppermost. In my opinion, the limb requires no bandaging or support as this can restrict the movement of the joint and may result in pressure sores. However, surgeons do vary in their decision to bandage patients following surgery.

Immediate application of an ice pack to the patient’s stifle will constrict the blood vessels around the site, resulting in less post-operative bruising and inflammation, which results in less pain. The ice pack should be wrapped in a towel and held in place for 15 to 30 minutes. This should be repeated four or five times over the first 24 hours.4 Ensure the ice pack is not applied directly over the plate, as the metal will absorb the cold rapidly resulting in the surrounding tissues not receiving the benefit. The pack should therefore be placed around the joint. However, be aware that the peroneal nerve is the smaller of the two ter
minal branches of the sciatic and is superficial; so the patient may encounter temporary nerve palsy from the excessive cooling.

Recovery from the anaesthetic may be rapid. A patient may be in sternal recumbency within two or three hours of the end of the procedure and by the afternoon should generally be able to get up. Although at this point, the affected limb is likely to be non-weight-bearing.

One day after surgery

Continue with the cold therapy – as performed immediately post operatively – because the limb may still begin to swell when the patient becomes mobile, owing to the increase in blood flow to the area.

Patients often tolerate well a passive range of motion exercise to the operated limb. The limb should be moved through the normal physiological movements available at the stifle, these being flexion and extension. But do not be tempted to massage the limb, as this will only increase the blood supply to the area, counteracting the effects of the cold therapy previously applied.

To perform passive extension and flexion exercises of the stifle, place a hand firmly around the femur and one on the tibia, move the stifle slowly through the available pain free range. The other joints of the hind limb: the hock, tarsus and hip will also need to be moved through the full range of motion in order to prevent stiffness. However it should be noted that these movements do not stop muscle atrophy and do not build muscle.

The limb as a whole should be moved, as it would be in its normal gait after each joint has been worked on separately. Each patient will have an individual pain tolerance level and an effective analgesic plan will help the patient recover quicker and allow mobility of the joint to begin as soon as possible.

The day following surgery, the passive range of motion (ROM) exercises indicated above can be applied to the patient approximately two or three times a day at 10 repeats per exercise.Most patients will usually go home on this day, and will therefore require a detailed plan of care to be produced for the owners.

On discharge

When the patient is discharged, short lead walks and active ROM exercises are encouraged. We advise the owners that the patient’s limb will need ice packing for a further five days to continue to avoid swellings.

Owners are given a pain assessment plan to help them to identify the degree of discomfort that the patient is in. This usually involves a chart showing how to recognise the different levels of pain. After the patient has returned home, a nurse should telephone the owner to discuss and assess patient recovery and levels of pain. It is important to be able to evaluate the efficacy of the analgesics being given to the patient and to undertake a review of medication if it is required. The phone call will also help provide valuable reassurance to concerned owners.

Once the patient is on the road to recovery, a nutritional support plan for the individual animal should be devised in order to prevent weight gain and to encourage the use of nutraceuticals to help joint mobility. Additional weight on the joint can compromise the recovery. The long-term weight management of the patient is also important because of the likelihood of secondary osteoarthritis.

And finally…

Ideally, the patient should be referred to a chartered veterinary physiotherapist who will make a full assessment and devise a structured recovery plan. This will give the patient and the owner stability and structure, allowing the stifle to return to normal function as soon as possible.


Laura Daniels


Laura has been in practice for four years, working in a busy Tier 3 Hospital based in Cheshire. Since qualifying in January 2009, she has developed a keen interest in orthopaedic nursing care and is working to build her knowledge in this field.


1.WILLIAMS,   N. (2009] Cranial Cruciate Ligament Rupture And Tibial Tuberosity Advancement Veterinary Times 39 (36]: 10-13.

2.   MARTIN, C., MASTERS, J. (2007] Textbook of Veterinary Surgical Nursing, Butterworth Heinemann

3.   HOTSTON MOORE, A., RUDD, S. (2008] BSAVA Manual of Advanced Veterinary Nursing British Small Animal Veterinary Association, Gloucester

4.   LEVINE, D., MILLS, D., TAYLOR, R. (2004] Canine Rehabilitation and Physical Therapy Saunders.

5.   MILLER, M. (1964] Anatomy of the Dog, W. B Saunders Company.

• VOL 25 • No4 • April 2010 • Veterinary Nursing Journal