CARTICEL REHAB PRINCIPLES

The principles that are used to protect against over stressing or overloading the graft early on have to do with weight bearing and range of motion restrictions. The middle and later phases of the protocol deal with the specific and biomechanically directed use of strength training and neuromuscular re-education.

Restricting weight bearing loads and limiting stressful motion serve to protect the graft site by avoiding forces that may compress or slough the newly implanted cells.

Developing muscular control, strength and endurance can protect the graft site by serving as a shock absorption system for forces that act through the joint and "across" the lesion.

The unique aspects of this protocol have to do with the use of biomechanical principles that take into account the location of the repair, the load tolerance of the repair, the alignment of the total extremity and the effective counter stress ability of the muscle groups surrounding the joint.

A proper progression in rehabilitation must follow the progressive healing of the repair site and its ability to tolerate compressive and shear loads. Those loads are represented as standing, walking, stair climbing, kneeling, squatting, jogging, running, cutting, i.e., the total of functional motions that the joint will be expected to go through.

I. Range of Motion Training

1. CPM- The use of CPM for the first 2 to 6 weeks postoperatively is to stimulate proper healing through cell orientation and integration. Unlike other orthopedic uses of CPM, the machine is used as long as is possible, up to 6 weeks post-op, to enhance proper modeling of the repair. (See Salter, RB, et al, JBJS, 62A:1232-1251, 1980 and Salter, RB, Clin Orthop 242: 12-25, 1989) Many patients feel that once they have attained the maximum range available on the CPM that they no longer need it. It is important for them to continue use it at least through the 4^th post-op week.

Femoral Condyles - Start comfortably at 0 to 40 degrees. Progress daily by 5 to 10 degrees or as tolerated to reach 90 to 110 degrees (or the maximum available on the CPM) in 2 weeks.

Trochlear Groove - Start comfortably at 0 to 40 degrees. Maintain this range for the first 2 weeks post-op. Increase the range by 5 degrees per day over the next 2 weeks to attain 90 to 110 degrees by the 4^th post-op week.

2. Manual range of motion - The patient can be instructed to work on self range by moving their own extremity with the assistance of their hands. Femoral condyle patients may perform both passive and active range of motion exercises.

II. Protection of the Graft - Weight Bearing

1. Ambulation - all patients will ambulate with crutches NWBing for the first 2 weeks post-op at a minimum. Most all patients will be braced, locked at 0 degrees, to protect the repair while being mobile. The repair site should not be directly loaded in full WBing for a total of 6 weeks post-op.

Femoral condyle patients may begin PWBing at 2 weeks post-op.

Weightbearing Progression: Instruct the patient to use crutches until 6 weeks post-op. A patient can gradually increase WBing through their leg from the 2^nd to 6^th week after surgery. They may progress to 1 crutch after the 4^th week if pain and swelling allow. The principle is to not fully WB the repair site until 6 weeks post-op. Patients are allowed to gradually add weight to their leg as their quad muscle begins to work as a load shock absorber.

Bracing: Patients braces are locked at 0 degrees with the onset of PWBing. As quad tone improves, which should be assessed by the physician or Physical Therapist, the brace can be opened 20 degrees at a time. In this way, the patient is only allowed to open the brace for a range through which he /she has adequate quad muscle control.

It may take up to 8 weeks for the patient to be able to ambulate painfree without the use of any assistive devices. If straight plane ambulation remains painful or causes effusion, an unloader brace may be used for all WBing activities to remove the single compartmental overloads involved with gait.

Trochlear groove patients may begin PWBing at 2 weeks post-op.

Weightbearing Progression: Instruct the patient to use crutches for a full 6 weeks post-op. In this way, the patient is prevented from being fully WBing until that time. A patient may progress to one crutch after the 4^th week post-op if pain and swelling allow. Trochlear patients WBing progression will be done primarily with the leg locked in full extension (see below).

Bracing: Trochlear patients must remain in their braces, locked at 0 degrees, until the 4th post-op week. This provides the patient with a stable leg to ambulate on and does not load the trochlear repair because the patella does not significantly engage in the groove when the knee is fully extended. These patients may begin to open their braces at the 4^th week post-op, initially by 20-30 degrees. Quad muscle function is even more important with trochlear lesion. Proper quad control and use helps to stabilize the patellar position in the trochlea thus avoiding increased patellofemoral loads. Therefore, expect a slower progression in opening their braces.

It may take up to 8 to 10 weeks to ambulate comfortably without devices. Unloader braces will not be effective with these patients secondary to the location of their repairs. A trochlear patient would be more likely to benefit from patellofemoral taping or a PF joint stabilizing soft brace if needed.

2. Graft size and location may vary this gait loading pattern. Directly loading the graft fully is held off for 6 weeks post-op in all cases.

III. Strengthening

1. Early Quad Control - Immediately post-op, it is important to gain quad control. This should happen with the assistance of a PT at approximately 1 week post-op.

Early quad control is gained by a heavy emphasis on isometric quad exercises with the knee locked in full extension. The exercises (primarily quad sets and straight leg raises) should be performed 1 to 2 times daily. The proper mastering of these exercises is critical and will determine the effectiveness of the progression through the next phases of strengthening. Proper quad control can not be emphasized enough. The lack of this control is frequently the reason a patient fails to progress effectively through the next levels of strengthening and function.

2. Progressive Strengthening - The next phases of strengthening will involve closed chain exercises in an isometric fashion. Closed kinetic chain exercises mean that the foot is in contact with a surface (a pedal, a platform, the ground, etc). These will first be performed in positions of non FWBing (supine leg press, leg sled or shuttle for example).

Patients start their exercises isometrically, as holds, to simplify the command to the muscle as well as isolate the forces through the joint in positions/ranges that are completely painfree. In this way, progressive strength training can commence without applying excessive loads on the healing repair site.

Isometric exercise to the quads can then progress to positions of standing (like a squat hold or a wall hold for example). This incorporates the next level of demand on the muscle group, assuming the strength is adequate, in such a way that the repair site is not compromised by excessive loading.

Patient should be worked in simple positions that are mechanically set up to unload the repair site yet place sufficient demand on the muscles to create a strengthening adaptation.

Patients should not be progressed to the higher levels of exercise, either in complexity of position or increasing loads, until they can thoroughly master the basic isometric closed chain positions.

Patients will spend a large portion of their rehabilitation time developing adequate closed chain strength. It is difficult to gain effective muscle strength and maintain it after a surgical intervention such as this. The tendency for a patient to lose neuromuscular control and thus begin to atrophy is great and should be guarded against by an acutely attentive PT.

3. Development of Strength - The emphasis on developing excellent neuromuscular control, strength and muscle hypertrophy is to capitalize on this system's ability to function as a shock absorber of forces that will act through the joint and across the repair site. By developing the muscles, additional protection at the graft site is achieved. For these reasons, rehabilitation becomes a very important factor in overall patient satisfaction and outcome. A technically excellent surgical repair requires the active co-operation of the patient and Physical Therapist to achieve maximum recovery. Function is built on a fully developed strength base.

IV. Functional Training

1. Proprioception - the body's ability to realize joint position in space. This concept is related to balance, response time and protective reflexes. This area of function should be focused on in every phase of the rehab progression. It is trained by cueing the patient on normal mechanics in every aspect of his/her motion. It is traditionally trained by exercises that stress balance with and without vision and at varying joint angles and ranges.
2. Assessment of physical demands - work, athletic, sport. As a patient reaches the later stages of rehabilitation, the PT should assess they varying physical demands of the patient's required and desired lifestyle. These various activities should be analyzed and broken down into components so that the patient can be tested and trained through the core motions. The patient should then be advanced to drill oriented exercise dosing, in this way, providing a gradual and methodical progression back to activity.
3. Return to impact, repetitive and lateral motions. In these activities, the repair sites will begin to be stressed to a greater level. It is often during this time that the patient may show some signs of difficulty with either increased swelling or pain, or both. The patient should be advised to back off activity and return to core strength work if this is the case. They may need a slower progression to these activities or may need the assist of some external devise such as an unloader brace, patellofemoral taping or brace stabilization or an orthotic. Each of these offer a different way to manipulate the forces as the act through the knee. The physician or PT will be intrumental in assessing this need. The patient should be re-assessed as well for any rehabilitation flaws. Be sure that they are maintaining excellent muscle function on a regular basis and have not resumed too much uncontrolled activity.
4. Final thoughts. At all times throughout the rehabilitation and healing process, remember that we are attempting to control and gradually reintroduce loads across a healing site. The cells have a rate of maturation with which they will regain characteristics of normal hyaline cartilage. Our goals in rehabilitation are to match and enhance the repair sites rate of change. When patients begin to do poorly, immediately reassess all factors that could be contributing to overload of the site: