Rehabilitation for knee patients (Proceedings)

Physical rehabilitation is becoming a common place therapy in veterinary medicine.  Several benefits have been proven and continue to be elucidated.  Postsurgical patients can be aided with increased blood flow, reduced inflammation, reduce muscle atrophy, pain control, reduced periarticular contracture and promoting osteotomy healing. However, caution should be used to avoid the mantra “no pain, no gain” with regards to physical rehabilitation.  Patient discomfort counteracts the goals of rehabilitation.  Also, owner compliance will diminish if pain is perceived.  All rehabilitation should be performed in a controlled setting.  Patients should be on a short leash in an area with carpet or good flooring for traction.  The animals should also never be left unattended. 

Cryotherapy should be used for the first 24 to 72 hours after surgery.  It needs to be applied for 15 to 25 minutes several times a day.  It can also be used after exercises later in the rehabilitation protocol.  Cryotherapy penetrates deeper than heat and reduces inflammation, edema formation, muscle spasms and pain.  You should always place insulation between the cold pack and skin and inspect the skin every few minutes.  Commercial ice packs, frozen bags of vegetables or a homemade ice pack of 1 part alcohol and 3 parts water can be used.  Cold packs used in your hospital should be sanitized between patients to prevent nosocomial infections.  It is also recommended covering incisions with vitamin A and D ointment or a triple antibiotic ointment to prevent the damp layer from potentially infecting the fresh surgical site. 

Heat therapy is a modality used as part of individualized physical therapy programs to achieve effects opposite to those of cryotherapy, however, both modalities are used to provide analgesia and decrease muscle spasms.  Heat therapy should not be initiated until the acute inflammatory response has already occurred due to the exacerbation of the effects of inflammation that may occur with heat therapy.  As cold therapy should be performed for the first 72 hours, heat therapy should only be initiated after 72 hours and continued for a period based on the individual patient, typically 5-7 days.  Beginning heat therapy too early can lead to worsening edema, swelling and potential seroma formation. 

Heat therapy can help with inflammation, decreased range of motion, pain, muscle tension, and preparation for additional exercises including stretching and walking exercises.  Goals of treatment with superficial heat are to provide analgesia, decreasing muscle spasms, increasing impulse conduction, increasing fibrous tissue elasticity, vasodilatation, and decreasing blood pressure if the heat is applied for long periods of time.  Heat therapy can also be used when beginning a session of therapeutic exercises. 

It is recommended 10 to 15 minutes of warm packs before a session and ending the exercises with 10 to 15 minutes of cold packing. Superficial heating agents include things such as hot packs, heat wraps, application of warm water, and towels immersed in hot water.  Hot packs are commercially available at many stores at fairly low prices.  Most hot packs contain gel of some type that can be reheated and reused many times. Electric blankets should not be used for warm packing due to their unpredictable hot zones and potential for burns.  Heat wraps are typically human products used to provide analgesia to veterinary patients. 

Caution should be taken when leaving these applied to the animal as they may cause skin burns. The person conducting the therapy should heat the hot pack in a microwave or boiling water to a temperature that can be tolerated by the therapist's skin.  A hot pack that is too hot can cause pain and skin burns.  The hot pack should never be placed directly on the skin or incision site, but should be placed in a cloth or towel prior to application to prevent burns. Warm packs should also be checked intermittently throughout the session to assure the animal's skin is not too hot. 

The use of towels immersed in hot water is a modality that can be easily performed in the private practice setting.  Multiple towels should be immersed in hot water, contained in a plastic baggie, and then placed on the affected area.  Another method using towels is to dampen the towel and warm it in the microwave.   Attention should be paid to ensure the towels are not so hot that they cause burns, as well as covering fresh incisions to avoid contamination.

Passive range of motion (PROM) can also be started within the first 48 hours after surgery as long as the patient is comfortable.  PROM decreases pain, helps prevent contracture, improves synovial fluid production, enhances blood and lymphatic flow.  PROM should be performed 2-6 times daily and can be performed with other stretching techniques.  Proper technique includes have a relaxed and comfortable patient.  The motion should be gentle so as to not create pain or discomfort.  The ROM should be smooth, slow and steady, isolating the knee.  Once the patient begins actively using the leg PROM may be exchanged for another weight bearing therapy. 

Walking exercises are indicated early in rehabilitation for animals refusing to use their affected limb.  Walking exercises can be initiated 2-4 weeks postoperatively from knee surgery depending on the procedure used and animals' comfort.  Osteotomy procedures usually begin more conservatively with less walking and shorter therapy sessions until some boney healing has occurred.  But all walking therapy should be in a controlled manner on a short leash.  Goals of walking exercises include increased range of motion, normal gait and placement, muscle mass and strength, improved circulation of blood and lymphatic vessels, increased endurance, and prevention of joint degeneration.   

Also, cranial cruciate ligament rupture repaired by tibial plateau leveling osteotomy, will benefit from slow, short walking exercise post operatively.  After the incision has healed, walking exercises are absolutely essential to achieve proper remobilization. Leash walking exercises are very easy to perform once the patient's ambulatory status permits exercise. 

The therapist should place a leash on the patient and position the patient on a firm surface that provides good footing.  The patient should be walked slowly so that the patient has adequate time to place each limb on the ground and shift their weight to that limb.  This ensures even therapy throughout all the limbs, including the affected limb.  As the patient improves and consistently places and increases strength in the affected limb, the therapist may increase the speed of the walking and eventually allow running while still on a leash.

Inclined walking up a gradual incline or walking up a short flight of stairs has essential therapeutic effects.  Increased mass and strengthening of the muscles in the hindlimbs, as well as increased flexion and extension and range of motion are the goals of this therapy.  The patient should initially be led up a gradual incline and progress to a steeper grade as they improve.  Also, the patient may initially be led up and down a flight of stairs with two or three steps, with increases in the number of steps as the patient improves.  If the practice does not have a set of stairs in it, a set can be made from wood relatively inexpensively. 

Additionally, weight shifting can be combined with walking exercises for stronger patients and to focus attention on the hindlimb muscle mass.  Walking patients in large circles will force weight on the interior legs.  However, care must be taken not to allow the patient to pivot on the inside legs and cheat.  Walking in a figure eight pattern will shift weight on all four legs but increase the amount of body weight forced on each leg with the turns.  Squats, or sit-to-stands, can be performed while walking a dog on a leash as well. These focus the dog on building their quadriceps and hamstrings.  You can intermittently have then sit down during the walks or perform sit-to-stands in a stationary manner. 

When performing squats it is vital to assure the dog sits down with both legs under their rump for maximal benefit.  This can be encouraged by placing the weaker leg against your leg or having them squat in the corner or against a wall.  For really advanced patients, dancing can be performed to further focus on one end of the dog.  Care must be taken to always have good footing and avoid causing stress or discomfort to the patient by pushing them too hard or too fast with their exercises.  Dancing should be performed once the surgical site has completely healed, but sit-to-stands can be initiated 2-4 weeks postoperatively during daily leash walks. 

Treadmill walking is a beneficial therapy modality that can be performed in the general practice.  Several companies manufacture treadmills made specifically for small animals, but many human treadmills may be modified to accommodate small animal patients.  Goals for treadmill walking are aimed at reducing pain, making the patient bear weight on the affected limb to strengthen muscles, and range of motion, and cardiovascular benefits.

Treadmills should be used carefully, with at least two handlers and a leash.  Training of the animal is important and usually successful in a short period of time.  Speeds should be started off slow, generally stay less than 1 mile per hour, until the animal has adapted to the therapy.  The continuously moving belt may cause the patient to concentrate on the treadmill and forget about the affected limb and enhance the use of that limb.  Treadmills achieve a greater range of motion for flexion and extension when compared to walking on the ground. 

This is particularly helpful for cruciate dogs since the lameness is associated with not only a loss of muscle mass but the loss in extension.  Some treadmills also have elevation settings that can be raised to produce incline walking which aids increased strength and range of motion.  Two people should always be present when therapy is being performed to ensure the prevention of injury to the patient. They may position themselves in front of the patient to encourage continuation of exercise, behind or above the patient to help support them and prevent falling, or beside the patient to help support the patient, and possibly aid the patient in gait and range of motion.  The treadmill should never be situated where the patient is facing the wall, as this may deter them from walking forward.

Treadmills are affordable and can be a valuable asset to a veterinary practice.  Canine treadmills can be purchased from numerous veterinary equipment providers.  Prices range from just under a thousand dollars to a few thousand dollars.  Human treadmills are less expensive, ranging from a few hundred to a few thousand dollars.  Modification of human treadmills for small animal patients can include the addition of side walls.  Land treadmill sessions can last from a few minutes to more than 30 minutes, especially in cases where endurance is being built.      

Hydrotherapy can easily be performed in the private practice setting using water as a rehabilitation tool.  Water is a great tool that may be employed to add to a rehabilitation protocol due to the forces of water.  Buoyancy is the upward force applied to an object or body in water and causes the effect of decreased weight. 

Hydrostatic pressure of water is exerted equally on all surfaces of a body that is immersed in water.  This may provide optimal environments for rehabilitation of limbs. Goals for rehabilitation with hydrotherapy include reduction in edema and fluid pooling due to hydrostatic forces, improved muscle mass and strength due to resistance of water, improved range of motion, and increased endurance, weight loss, and decreased pain. Most veterinary practices have a large bathtub. 

Hydrotherapy should only be initiated after the surgical incision has healed.  Fill the tub with water to the level of the greater trochanter for the early postoperative knee patient, and lower it as their recovery progresses to switch from buoyancy to resistance training.  Place the patient in the tub and allow them to walk around.  The therapist may stand at the head of the tub and entice the patient to move around by offering treats or playing with a ball or toy. 

The forces of water acting on the body will reduce the weight being supported by the patient's limbs, which may allow them to ambulate and perform specific exercises more easily than on dry land.  Based on one study, when the water level is filled to the level of the hip, the animal only bears 38 percent of their body weight on their limbs.  This will help the early postoperative knee patient who is reluctant to bear full weight on their knee.  However, lowering the water and walking in a bathtub will cause resistance and increase the amount of work on the legs to help build muscle and strength. 

Therefore, hydrotherapy can be used to make walking easier or more difficult depending on the water level and resistance.  The therapist should never leave the dog unattended and take caution to not allow the patient to become fully submerged, as this may cause the patient to aspirate.  Canine life vests are commercially available, but do not replace the need for constant supervision while in the tub.  If the patient has access to a pool or pond, these may also be used for walking or swimming once the patient becomes adapted to hydrotherapy. 

Rehabilitation is an essential aspect of the recovery plan for small animal patients and protocols should be tailored for the individual patient based on their surgical procedure and stage of recovery.  A wide variety of simple modalities are at the practioner's disposal to enhance rehabilitation and recovery time. 

All therapy sessions take patience and practice, some exercises or modalities may work better for different patients' temperament and specific conditions.  Also rehabilitation changes as the animal improves and recovers, so there are no concrete rules.  You must be educated about physical rehabilitation, creative and flexible with your protocols and adjust them for each situation.