Modalities

The postoperative rehabilitation protocol after tibial and femoral osteotomy is summarized in Table 33-2. In the immediate postoperative period, knee pain and effusion must be controlled to avoid quadriceps muscle inhibition or shutdown. Electrogalvanic stimulation or high-voltage electrical muscle stimulation (EMS) may be used to augment ice, compression, and elevation to control swelling. The treatment duration is approximately 30 minutes and the intensity is set to patient tolerance.

Once the joint effusion is controlled, functional EMS is begun for muscle reeducation and facilitation of an adequate quadriceps contraction. One electrode is placed over the vastus medialis obliquus and the second electrode is placed on the central to lateral aspect of the upper third of the quadriceps muscle belly. The patient is instructed to actively contract the quadriceps muscle simultaneously with the machine’s stimulation. The treatment duration is 20 minutes. A portable EMS machine for use at home may be required in individuals whose muscle rating is poor. EMS is continued until the muscle grade is rated as good.

Biofeedback therapy is an important adjunct to facilitate an adequate quadriceps muscle contraction early postoperatively. The surface electrode is placed over the selected muscle component to provide feedback to the patient and the clinician regarding the quality of active or voluntary quadriceps contraction. Biofeedback is also useful in enhancing hamstring relaxation if the patient experiences difficulty achieving full knee extension secondary to knee pain or muscle spasm. The electrode is placed over the belly of the hamstring muscle while the patient performs range of motion exercises.

Cryotherapy is begun immediately after surgery. The standard method is an ice bag or commercial cold pack. However, patients prefer motorized cooler units because they maintain a constant temperature and circulation of ice water, which provides excellent pain control. Gravity flow units are also effective; however, temperature maintenance is more difficult with these devices than with the motorized cooler units. Cryotherapy is used from three times a day to every waking hour for 20 minutes at a time depending upon the extent of pain and swelling. In some cases, the treatment time is extended owing to the thickness of the buffer that exists between the skin and the device. Cryotherapy is typically done after exercise or when required for pain and swelling control and is maintained throughout the entire postoperative rehabilitation protocol.

Postoperative Bracing and Weight-Bearing

A long-leg postoperative brace is worn for the first 8 to 12 weeks postoperatively. Patients then discontinue use of the brace, but if they continue to experience pain, Visco heel pads are used to unload the affected compartment. A lateral wedge is used for patients who underwent HTO, whereas a medial wedge is used for those who had a DFO. If pain remains, an unloading brace, used initially in a neutral position and then adjusted based on patient response, is recommended (Fig. 33-1).

FIGURE 33-1 An unloading brace may be used and adjusted based on patient pain response.

Initially, patients are allowed only toe-touch weight-bearing. They are encouraged during this time period to lightly touch the ground with the toes of the operated limb while standing, with the visual image of stepping on a sponge, as frequently as possible during the day. At 4 weeks postoperative, double-stance, full-length anteroposterior radiographs are taken to determine osteotomy healing. Patients are then allowed to bear 25% of their body weight if the radiographs demonstrate adequate healing and maintenance of the osteotomy position and fixation implant (Fig. 33-2). A normal gait pattern is advocated that encourages normal knee flexion throughout the gait cycle. This technique allows for normal patterning of heel-to-toe ambulation, quadriceps contraction during midstance, and hip and knee flexion during the gait cycle. Average healing of the fracture site occurs at approximately 8 to 10 weeks postoperatively. In patients in whom allograft bone is used to fill the osteotomy gap, an additional delay in full weight-bearing may be required for up to 12 weeks postoperatively to allow for bony consolidation.

FIGURE 33-2 Postoperative anteroposterior radiograph after opening wedge tibial osteotomy with an iliac crest autograft and locking plate–screw fixation shows beginning healing and maintenance of the fixation position, although full activities are possible only with complete filling-in of the osteotomy gap.

Range of Knee Motion

The postoperative goals for knee flexion and extension are shown in Table 33-3. Patients are encouraged to regain 0° to 90° within the first 2 weeks. Patients perform passive and active range of motion exercises in a seated position for 10 minutes a session, approximately three to four times per day.

Patients that have difficulty regaining at least 0° by the 2nd week are placed into an overpressure program using a propped foot/ankle position (Fig. 33-3). This position is maintained for 10 minutes and repeated four to six times per day. A 10-pound weight may be added to the distal thigh and knee to provide overpressure to stretch the posterior capsule. If this method is not successful in achieving full extension, or if the clinician notes a firm end feel, an extension board or additional weight of 15 to 20 pounds may be used up to six times a day.

FIGURE 33-3 Overpressure extension exercise.

Knee flexion is gradually increased to 110° by the 3rd to 4th postoperative week, 130° by the 5th to 6th week, and 135° by the 7th to 8th week. Methods to assist in achieving flexion greater than 90° include chair-rolling, wall-slides, knee flexion devices, and passive quadriceps stretching exercises (Fig. 33-4).

FIGURE 33-4 Flexion overpressure exercise options include rolling stool (A), wall-slides (B), and commercial devices (C).

Patellar Mobilization

The resumption of normal patellar mobility is critical to regain a normal range of knee motion. The loss of patellar mobility is often associated with arthrofibrosis and, in extreme cases, the development of patella infera. Patellar glides are performed in all four planes (superior, inferior, medial, and lateral) beginning the 1st postoperative day with sustained pressure applied to the appropriate patellar border for at least 10 seconds (Fig. 33-5). This exercise is done for 5 minutes before range of motion exercises. Caution is warranted if an extensor lag is detected because this may be associated with poor superior migration of the patella, indicating the need for additional emphasis on this exercise. Patellar mobilization is performed for approximately 8 weeks postoperatively.

FIGURE 33-5 Patellar mobilization.

Flexibility

Hamstring and gastrocnemius-soleus flexibility exercises are begun the 1st day after surgery. A sustained static stretch is held for 30 seconds and repeated five times. Common methods for stretching these muscle groups include the modified hurdler stretch and the towel pull. These exercises help control pain due to the reflex response created in the hamstrings when the knee is maintained in the flexed position. As well, the towel-pulling exercise can help lessen discomfort in the calf, Achilles tendon, and ankle. Quadriceps and iliotibial band flexibility exercises are begun at the 9th postoperative week.

Strengthening

The strengthening program is begun on the 1st postoperative day (Table 33-4). Isometric quadriceps contractions are done hourly using the repetition rules of 10-second holds, 10 repetitions, 10 times per day. The patient is taught to monitor the contractions by visual or manual means, comparing the quality with those achieved by the contralateral limb. The superior migration of the patella is observed and should be approximately 1 cm during contractions, with inferior migration also seen during the initial relaxation of the contraction. The knee is held in a slightly flexed position during isometric contractions. Biofeedback may be used to reinforce an adequate quadriceps contraction.

Open kinetic chain extension exercises are incorporated within the first few weeks to further develop quadriceps muscle strength. Caution is warranted owing to the potential problems these exercises may create for the patellofemoral joint. Resisted knee extension is begun with Velcro ankle weights from 90° to 30°. The terminal phase of extension is avoided owing to the high forces placed on the patellofemoral joint. The patellofemoral joint must be monitored for changes in pain, swelling, and crepitus to avoid a patellar conversion in which painful patellofemoral crepitus develops with articular cartilage damage.

Straight leg raises are begun the 1st postoperative day in the hip flexion plane (supine position) only. These exercises are advanced to include the hip extension plane during the 3rd week. Patients who underwent HTO begin straight leg raises in the abduction/adduction planes between 4 and 6 weeks postoperatively based on x-ray evidence of healing. These exercises are begun between 6 and 8 weeks postoperatively in patients who underwent DFO based on x-ray evidence of healing. As these exercises become easy to perform, ankle weights are added to progress muscle strengthening. Initially, 1 to 2 pounds of weight are used, and eventually, up to 10 pounds is added as long as this is not more than 10% of the patient’s body weight. Initially, weight is applied above the patella to control forces to the healing fracture. The use of rubber tubing to provide increased resistance may also be of benefit starting at the 7th to 8th postoperative week.

Another common exercise effective in helping with quadriceps reeducation is the straight leg plus raise (Fig. 33-6). The quadriceps is contracted, the leg is lifted approximately 6 inches off the table or chair, held in the lifted position for 15 seconds, and then lowered and relaxed for 45 seconds. This 1-minute cycle is maintained and progressed in ratios (1:3, 1:2, and eventually, 1:1), and then progressed from 5 to 10 repetitions, with additional ankle weight added to increase the difficulty of the exercise.

FIGURE 33-6 The straight leg raise plus exercise.

Toe-raises are begun during the 3rd to 4th week as tolerated. Closed kinetic chain exercises may be initiated during the 5th to 6th week. Mini-squats from 0° to 45° are begun when tolerated by the patient. Initially, the patient’s body weight is used as resistance, and gradually, TheraBand or surgical tubing is added for resistance (Fig. 33-7). Quick, smooth, rhythmic squats are performed to a high-set/high-repetition cadence to promote muscle fatigue. Wall-sitting exercises are also begun during this time period. The goal of wall-sitting is to improve quadriceps contraction by performing the exercise to muscle exhaustion. If anterior knee pain is experienced, either the knee flexion angle of the sit or the toe-out/toe-in angle is altered. The exercise may also be modified by the patient squeezing a ball between the distal thighs, holding dumbbell weights, or shifting the body weight over the involved side to stimulate a single-leg contraction. This exercise is promoted as an excellent one to perform at home four to six times a day to achieve quadriceps fatigue in a knee flexion angle that does not induce anterior knee pain. Leg press exercises in the range of 70° to 10° are begun during this time period as well.

FIGURE 33-7 Closed chain exercise examples of mini-squats (A) and wall-sits (B and C).

Lateral step-ups are initiated when the patient has achieved full weight-bearing, at approximately 7 to 8 weeks. The height of the step is gradually increased based on patient tolerance. Strengthening is also initiated during this time for hip abductors, adductors, flexors, and extensors by using either a multi-hip or cable system machine, or a hip abductor/adductor machine. Hamstring curls on a weight machine are begun at 9 to 12 weeks postoperative.

Balance, Proprioceptive, and Perturbation Training

Cup-walking is an exercise that promotes symmetry between the surgical and the uninvolved limbs. This exercise helps develop hip and knee flexion and quadriceps control during midstance of gait to prevent knee hyperextension (see Chapter 34, Correction of Hyperextension Gait Abnormalities: Preoperative and Postoperative Techniques). In addition, cup-walking controls hip and pelvic motion during midstance, gastrocnemius-soleus activity during push-off, and excessive hip hiking (Fig. 33-8). This exercise may be initiated during the partial weight-bearing phase.

FIGURE 33-8 Cup- (or cone-) walking.

Balance and proprioceptive training are initiated when the patient has resumed full weight-bearing. Initially, the patient stands and shifts the body weight from side-to-side and front-to-back. This activity encourages confidence in the leg’s ability to withstand the pressures of weight-bearing and initiates the stimulus to knee joint position sense.

Double- and single-leg balance exercises in the stance position are also beneficial. During the single-leg exercise, the foot is pointed straight ahead, the knee flexed 20° to 30°, the arms extended outward to horizontal, and the torso positioned upright with the shoulders above the hips and the hips above the ankles. The patient is encouraged to remain in this position until balance is disturbed. A minitrampoline or unstable platform may be used to make this exercise more difficult. Patients may assume the single-leg stance position and throw or catch a weighted ball against an inverted minitrampoline until fatigue occurs.

Perturbation-training techniques are also performed during balance exercises. The therapist stands behind the patient and disrupts her or his body posture and position periodically to enhance dynamic knee stability (Fig. 33-9). The techniques involve either direct contact with the patient or disruption of the platform the patient is standing on, and the patient is then instructed to correct the unbalanced position.

FIGURE 33-9 A and B, Perturbation-training techniques.

Half foam rolls are also used in this time period as part of the gait-retraining and balance program (Fig. 33-10A). This technique helps the patient develop balance and dynamic muscular control required to maintain an upright position and be able to walk from one end of the roll to the other. Use of a balance board or other unstable platform in double-leg and single-leg stance is another effective measure (see Fig. 33-10B). Developing a center of balance, limb symmetry, quadriceps control in midstance, and postural positioning are benefits obtained from this type of training.

FIGURE 33-10 Balance training techniques include walking on half foam roll (A) and single-leg stance on an unstable surface (B).

Conditioning and Return to Activities

Depending on accessibility, a cardiovascular program with an upper body cycle may be initiated as soon as tolerated by the patient (Table 33-5). The surgical limb should be elevated to minimize lower extremity swelling. Stationary bicycling is begun during the 5th to 6th postoperative weeks. Water-walking is also begun during this time period.

Cross-country ski, elliptical, and stair-climbing machines are permitted 9 to 12 weeks postoperatively. Protection against high stresses to the patellofemoral joint is required. The seat height of the bicycle is adjusted to its highest level based on patient body size, and a low resistance level is recommended. Stair-climbing machines are adjusted to produce a short step with low resistance. An aquatic program that includes lap work using freestyle or flutter kicking, water-walking, and water aerobics is encouraged if the patient has access to a pool. In order to improve cardiovascular endurance, the program should be done at least three times per week for 20 to 30 minutes, with the exercise performed to at least 60% to 85% of maximal heart rate.

The majority of patients who undergo HTO or DFO are advised to return to only light, low-impact activities to maintain an active and healthy lifestyle and weight control. Patients who express the desire to return to higher-impact sports activities are advised of the risk of further cartilage deterioration if damage was noted during the operation. Because the usual goal of osteotomy is to buy time before the necessity for a partial or total joint replacement, participation in high-loading activities is discouraged.