CLINICAL CONCEPTS

The postoperative program for meniscus repair and transplantation is shown in Table 30-1. The initial goal is to prevent excessive weight-bearing, because high compressive and shear forces can disrupt healing meniscus repair sites (especially radial repairs) and transplants. Variations are built into the protocol according to the type, location, and size of the meniscus repair and whether concomitant procedures (such as ligament reconstructions) are performed. The surgeon has the responsibility to inform the physical therapy team of details regarding the type of tear and the repair that was performed. Meniscus repairs with all-inside fixators have inferior holding strength, and commonly, only a few sutures are used. These repairs require more protection to allow for healing during the first 6 postoperative weeks. Inside-out meniscus repair techniques involve multiple vertical divergent sutures (see Chapter 28, Meniscus Tears: Diagnosis, Operative Techniques, and Clinical Outcomes) and have superior holding strength.

Clinicians should be aware that meniscus repairs located in the periphery (outer third region) heal rapidly, whereas complex repairs that extend into the central third region tend to heal more slowly and require greater caution. In addition, modifications to the postoperative exercise program may be required if noteworthy articular cartilage deterioration is found during the arthroscopic procedure. This rehabilitation program has been used at the authors’ institution in hundreds of meniscus transplant and repair recipients, and the results of clinical investigations3–5,⁷ demonstrate its safety and effectiveness in restoring normal knee motion, muscle, and gait characteristics.

Patients receive instructions before surgery regarding the postoperative protocol so they have a thorough understanding of what is expected after surgery. Patients are warned that an early return to strenuous activities including impact loading, jogging, deep knee flexion, or pivoting carries a definite risk of a repeat meniscus tear or tear to the transplant. This is particularly true in the first 4 to 6 months postoperatively.

The supervised rehabilitation program is supplemented with home exercises that are performed daily. The therapist routinely examines the patient in the clinic in order to implement and progress the appropriate protocol. Therapeutic procedures and modalities are used as required for successful rehabilitation. On average, patients require 11 to 16 physical therapy visits over 9 to 12 months to produce a desirable result.

Lateral and anteroposterior plain radiographs are obtained 1 week postoperatively to verify the position of the osseous component of meniscus transplants and at 6 to 8 weeks to verify healing and retention of the bony portion of the transplant within the slot or tunnels. Any onset of tibiofemoral joint line clicking or pain may indicate failure of the meniscus repair or transplant and should be noted immediately for consideration of refixation.

IMMEDIATE POSTOPERATIVE MANAGEMENT

Important early postoperative signs for the therapist to monitor include effusion, pain, gait, knee flexion and extension, patellar mobility, strength and control of the lower extremity, lower extremity flexibility, and tibiofemoral symptoms indicative of a meniscal tear (Table 30-2).

TABLE 30-2 Postoperative Signs and Symptoms Requiring Prompt Treatment

EMS, electrical muscle stimulation; ROM, range of knee motion.

From Heckmann, T.; Barber-Westin, S. D.; Noyes, F. R.: Meniscal repair and transplantation: Indications, techniques, rehabilitation, and clinical outcome. J Orthop Sports Phys Ther 36:795–814, 2006.

Patients present to physical therapy on the 1st day after surgery on bilateral axillary crutches in a postoperative dressing with a long-leg brace locked in full extension. The postoperative bandage and dressing are changed to allow the application of thigh-high compression stockings and a compression bandage. Early control of postoperative effusion is essential for pain management and early quadriceps reeducation. In addition to compression, cryotherapy is critical in this time period. Patients receive a commercial cooling unit, which is used six to eight times daily at home. In the clinic, the use of various cryotherapy machines provide compression simultaneously with the cold program (Fig. 30-1).

FIGURE 30-1 A clinical cryotherapy machine that provides compression with the cold program (Game Ready, Berkeley, CA) is used in the initial postoperative period.

Patients are instructed to maintain lower limb elevation as frequently as possible during the 1st week. A portable neuromuscular electric stimulator may be helpful for quadriceps reeducation and pain management (Fig. 30-2). These devices are used six times per day, 15 minutes per session, until the patient displays an excellent voluntary quadriceps contraction.

FIGURE 30-2 A portable neuromuscular electric stimulator (EMPI, St. Paul, MN) is effective for quadriceps reeducation and pain management in the early postoperative phase.

The patient’s initial response to surgery and progression during the first 2 weeks sets the tone for the initial phases of the rehabilitation program. Common postoperative complications include excessive pain or swelling, quadriceps shutdown or loss of voluntary isometric contraction, range of motion (ROM) limitations, and saphenous nerve irritations for medial repairs. It is important to monitor patient complaints of posteromedial or infrapatellar burning, posteromedial tenderness along the distal pes anserine tendons, tenderness of Hunter’s canal along the medial thigh, hypersensitivity to light pressure, or hypersensitivity to temperature change. These abnormal symptoms or signs occur in early cases of complex regional pain syndrome (see Chapter 43, Diagnosis and Treatment of Complex Regional Pain Syndrome) and require immediate treatment.

BRACE AND CRUTCH SUPPORT

A long-leg postoperative brace is placed immediately after surgery following complex meniscus repairs or transplants. The brace is opened from 0° to 90°, but it is locked at 0° extension at night for the first 2 weeks. Thereafter, the brace is not routinely locked except in patients who cannot maintain 0° of extension. In these cases, the brace is locked at 0° extension as required during the day and night. The brace is used for 6 weeks. A brace is not routinely used after repair of a peripheral meniscus tear unless an all-inside fixator with only a few sutures is used for added protection.

Crutches with partial weight-bearing are recommended for the first 4 weeks in all cases. Weight-bearing is gradually progressed as shown in Table 30-1, and patients are encouraged to use a normal gait that avoids a locked knee and assumes normal flexion throughout the gait cycle. Patients who had a repair of a radial meniscus tear are kept non–weight-bearing for 4 weeks to protect the repair site.

RANGE OF KNEE MOTION AND FLEXIBILITY

Passive knee flexion and passive and active/active-assisted knee extension exercises are begun the 1st day postoperatively. Active knee flexion is limited to avoid hamstring strain to the posteromedial joint. ROM exercises are performed in the seated position initially from 0° to 90°. Flexion is gradually advanced to 120° by the 3rd to 4th week and 135° by the 5th to 6th week (Table 30-3). Patients who had extensive repairs may be required to limit ROM to 0° to 90° for the first 2 weeks. Knee motion exercises are performed three to four times daily until normal motion is achieved. Hyperextension is avoided in individuals who have had anterior horn meniscus repairs.

If 0° to 90° of knee motion is not easily achieved by the end of the 1st postoperative week, the patient may be at risk for a knee motion complication. Individuals who develop such a limitation are placed into a specific treatment program previously described in detail.^2,6 Overpressure exercises are usually successful in achieving the last few degrees of extension if initiated within the first few weeks after surgery. The patient props the foot and ankle on a towel to elevate the hamstrings and gastrocnemius, which allows the knee to drop into full extension. A 10-pound weight may be added to the distal thigh and knee to stretch the posterior capsule (Fig. 30-3). This program is done for 10 minutes at a time, six to eight times per day.

FIGURE 30-3 Extension overpressure hanging-weight exercise.

Flexion exercises are performed in the seated position, using the opposite lower extremity to provide overpressure (Fig. 30-4). Chair-rolling, wall-sliding, passive quadriceps stretching, and ROM devices such as the ERMI Knee Flexionator (ERMI, Atlanta, GA) are also helpful in regaining full knee flexion. It is important that no squatting exercises are performed for at least 4 months, because this places large tensile forces on posterior meniscus repairs and transplants.

FIGURE 30-4 Flexion exercise using the opposite knee to apply pressure.

ROM exercises are accompanied by patellar mobilization (in the superior, inferior, medial, and lateral directions), which is paramount to achieve full knee motion (Fig. 30-5). Flexibility exercises, beginning with hamstring and gastrocnemius-soleus, are begun the 1st day postoperatively and are done three times per day. Quadriceps and iliotibial band flexibility exercises are incorporated at 7 to 8 weeks postoperative. Sustained static stretching is performed, with the stretch held for 30 seconds and repeated five times.

FIGURE 30-5 A and B, Patellar mobilization exercises (in the superior, inferior, medial, and lateral directions), paramount in regaining a full range of motion, are initiated the 1st day postoperatively.

The knee motion program is effective, because no patient in the authors’ clinical studies who had an isolated meniscus repair or transplant required further surgery for a knee motion complication. Only 2 of 193 patients who had meniscal repair, and 4 of 38 patients who had a transplant, required a gentle manipulation for a limitation of flexion. In these 6 patients, a major concomitant procedure, such as a cruciate ligament reconstruction, had been performed.

Close supervision and additional exercises may be required in patients who undergo combined procedures to successfully restore normal knee motion. No difference exists between medial and lateral meniscus repairs or transplants in regard to knee motion complications.

BALANCE AND PROPRIOCEPTIVE TRAINING

Balance and proprioception exercises are initiated when patients achieve partial weight-bearing, typically the 1st week after surgery. Crutches are used for support during these exercises until full weight-bearing is allowed. Initially, patients perform weight-shifting from side-to-side and front-to-back. Then, cup-walking is encouraged to develop symmetry between the surgical and the contralateral limbs, hip and knee flexion, quadriceps control during midstance, hip and pelvic control during midstance, and adequate gastrocnemius-soleus control during push-off (Fig. 30-6).

FIGURE 30-6 A and B, Cup-walking is used early postoperatively to develop symmetry between the surgical and the contralateral limbs, hip and knee flexion, quadriceps control during midstance, hip and pelvic control during midstance, and adequate gastrocnemius-soleus control during push-off. This exercise also facilitates quadriceps control to prevent knee hyperextension from occurring during gait.

Tandem balance is begun during the partial weight-bearing phase to assist with position sense and balance. Single-leg balance exercise is also done by pointing the foot straight ahead, flexing the knee to 20° to 30°, extending the arms outward to horizontal, and positioning the torso upright with the shoulders above the hips and the hips above the ankles. The patient stands in this position until balance is disturbed. A minitrampoline is used to make this exercise more challenging after it is mastered on a hard surface.

Many devices are available to assist with balance and gait retraining, including Styrofoam half rolls and whole rolls, and the Biomechanical Ankle Platform System (BAPS, Camp, Jackson, MI). Patients walk (unassisted) on Styrofoam half rolls to develop a center of balance, quadriceps control in midstance, and postural positioning. The BAPS board is used in double-leg and single-leg stance to promote proprioception. More sophisticated devices are also available (Fig. 30-7), including Biodex’s Balance System (Biodex Corporation, Shirley, NY) and Neurocom’s Balance System (Neurocom, Clackamas, OR). These devices provide visual feedback to assist with a variety of balance activities.

FIGURE 30-7 A sophisticated balance device (Biodex Corporation, Shirley, NY) provides visual feedback to assist with a variety of balance activities.

The proprioceptive training includes plyometric exercises, which are incorporated in the end-stage of rehabilitation to provide a functional basis for return to activity for patients who desire to return to strenuous sports activities. These exercises are promoted in younger athletic patients who have an associated anterior cruciate ligament reconstruction. These exercises are described in detail later in this chapter.

STRENGTHENING

The strengthening program is begun on the 1st day postoperative with quadriceps isometrics, straight leg raises (Fig. 30-8), and active-assisted knee extension from 90° to 30° (Table 30-4). Initially, straight leg raises are performed in the flexion plane only. The patient must achieve a sufficient quadriceps contraction to eliminate an extensor lag before adding straight leg raises in the other three planes (abduction, adduction, and extension). These exercises are performed as three to five sets of 10 repetitions, and this set/repetition rule allows for systematic progression of ankle weights as tolerated.

FIGURE 30-8 A–D, Straight leg raises shown in flexion, abduction, adduction, and extension planes.

At weeks 3 to 4, closed kinetic chain weight-bearing exercises are begun. Toe-raises for gastrocnemius-soleus strengthening, wall-sits, and mini-squats for quadriceps strengthening are added when patients are 50% weight-bearing. Wall-sits (Fig. 30-9) and mini-squats (Fig. 30-10) are begun at 5 to 6 weeks postoperative after meniscal transplantation. These activities should be limited from 0° to 60° of flexion to protect the posterior horn of the meniscus.

FIGURE 30-9 Wall-sit exercises are begun 3 to 4 weeks after meniscus repair and 5 to 6 weeks after meniscal transplantation. This exercises is limited from 0° to 60° of flexion to protect the posterior horn of the meniscus.

FIGURE 30-10 Mini-squats, begun 3 to 4 weeks after meniscus repair and 5 to 6 weeks after meniscal transplantation, are an effective quadriceps strengthening exercise.

Wall-sitting isometrics can be made more challenging by modifying the exercise technique. First, the patient can voluntarily set the quadriceps muscle once he or she reaches the maximum knee flexion angle, which is typically between 30 and 45°. This contraction and knee flexion position are held until muscle fatigue occurs, and the exercise is repeated three to five times. In a second modification, designed to promote a stronger vastus lateralis obliquus contraction, the patient performs a hip adduction contraction by squeezing a ball between the distal thighs. In a third variation, the patient holds dumbbell weights in the hands to increase body weight, which promotes an even stronger quadriceps contraction. Finally, the patient can shift the body weight over the involved side to simulate a single-leg contraction.

Mini-squats are initially done using the patient’s body weight as resistance. Gradually, TheraBand or surgical tubing is used as a resistance mechanism. The depth of the squat is controlled to protect the meniscus repair or transplant and the patellofemoral joint. Quick, smooth, rhythmic squats are performed to a high-set/high-repetition cadence to promote muscle fatigue. Hip position is important to monitor in order to emphasize the quadriceps.

Open kinetic chain non–weight-bearing exercises are begun 5 to 6 weeks postoperative (see Table 30-4). Knee extension progressive resistive exercises (PREs) are initiated from 90° to 30° to protect the patellofemoral joint.¹ By keeping the quadriceps exercises in this protected ROM, minimal forces will be placed along peripheral and midsubstance repair sites. Progression from ankle weights to machines occurs as the patient progresses the amount of weight in the exercise program. Quadriceps control is critical to the program progression.

Hamstring curls from 0° to 90° are initiated in patients who had peripheral meniscus repairs at the same time as the knee extension PREs. Care should be taken to avoid hyperextension, which places tension on the posterior capsule. This exercise is delayed until at least 7 to 8 weeks after a complex meniscus repair and until 9 to 12 weeks after meniscus transplantation. Isolated resisted hamstring curls are limited in complex repairs and transplants owing to the medial hamstring insertion along the posteromedial joint capsule. This limitation is designed to lessen potential traction forces being imposed onto the repair site. Initially, hamstring curls are done with Velcro ankle weights; then the exercise is progressed to weight machines.

A leg press machine is initiated in the range of 70° to 10° at 5 to 6 weeks after all meniscus repairs and at 9 to 12 weeks after transplantation. The limitation in flexion is incorporated owing to the increased load placed on the posterior horn of the meniscus after 60° to 70° of flexion.

Side-lying straight leg raises are initiated early in the rehabilitation program. Later, when patients have access to the cable column or multi-hip machines, hip flexion, extension, abduction, and adduction are also included in the exercise program. These activities are implemented at 5 to 6 weeks postoperative.

CONDITIONING

A cardiovascular program may be begun as early as 2 to 4 weeks postoperatively if the patient has access to an upper body ergometer (Table 30-5). Stationary bicycling is begun 7 to 8 weeks postoperative. The seat height is adjusted to its highest level based on patient body size, and a low-resistance level is used. A recumbent bicycle may be substituted in patients who have damage to the patellofemoral joint articular cartilage or anterior knee pain.

Water-walking may be implemented during this timeframe. Walking in waist-high water decreases the impact load to the knee by 50%. To protect the healing meniscus, swimming with straight leg kicking and dry land walking programs are initiated between the 9th and the 12th weeks. At this time, patients who had a meniscus repair may also begin using stair-climbing, elliptical cross-trainers, or cross-country ski machines. Protection against high stresses to the patellofemoral joint is required in patients with symptoms or articular cartilage damage. If a stair-climbing machine is tolerable, a short step is maintained with low resistance levels. The cardiovascular program should be done at least three times a week for 20 to 30 minutes, and the exercise should be performed to at least 60% to 85% of maximal heart rate.

RUNNING PROGRAM

A running program is begun at approximately 20 weeks postoperative in patients who had peripheral meniscus repairs and who have no more than a 30% deficit in average peak torque for the quadriceps and hamstrings on isometric testing performed on a Biodex dynamometer (Biodex Corp., Shirley, NY). This program is delayed until approximately 30 weeks postoperative in patients who had complex meniscus repairs and until at least 1 year postoperative in patients who had a meniscus transplant.

Isometric muscle testing is initially performed at an angle of 60° of knee flexion, which places the knee in a protected position for both the meniscus and the patella. Progression to isokinetic testing at high speeds is important, but the initial goal is to test the integrity of the quadriceps and hamstring musculatures. Other testing parameters worth evaluating include peak torque–to–body weight ratios, agonist-to-antagonist ratios, and time to peak torque values.

Patients begin with a walk/run combination program, using running distances of 18, 37, 55, and 91 meters. Initially, patients run at 25% to 50% of their normal speed. Once patients can run straight ahead at full speed, lateral and crossover maneuvers are added. Short distances (such as 18 m) are used to work on speed and agility. Side-to-side running over cups may be used to facilitate agility and proprioception. Figure-eight and carioca running drills are also useful.

PLYOMETRIC TRAINING

Progressive plyometric training is initiated upon successful completion of the running program. These activities are typically incorporated after 6 months postoperative in patients who have had a large peripheral tear or complex repair. In patients who had a radial meniscus repair, this program may be delayed until 9 months postoperative owing to the disruption that occurred in the hoop stresses of the meniscus.

Individual sessions are performed in a manner similar to that for interval training. Initially, a rest period is incorporated that lasts two to three times the length of the exercise period; this is gradually decreased to one to two times the length of the exercise period. In addition, plyometric hopping is performed two to three times each week and is incorporated into the strength and cardiovascular endurance program.

The program beings with level-surface box-hopping. A four-square grid of four equal-sized boxes is created on the floor with tape. The patient first hops from box 1 to box 3 (front-to-back), and then from box 1 to box 2 (side-to-side). This drill is initially performed using both legs, with the body weight kept on the ball of the foot.

The patient hops as fast as possible with the knees bent and lands in flexion to avoid knee hyperextension. It is important for the patient to focus on limb symmetry during this exercise.

The initial exercise time period lasts 15 seconds, with the patient completing as many hops between the squares as possible. Three sets are performed for both directions, and the number of hops is recorded. Progression of the program occurs as the number of hops, as well as patient confidence, improves. This exercise has four levels. The first level includes front-to-back and side-to-side hopping, as previously described. The second level incorporates both of the directions in level one into one sequence and also includes hopping in both right and left directions (i.e., box 1 to box 2 to box 4 to box 2 to box 1). Level three progresses to diagonal hops, and level four includes pivot hops in a 180° direction. Once the patient can perform level-four double-leg hops, similar exercises are initiated using single-leg hops. Vertical box hops are incorporated into the next phase of plyometric exercises.

Important parameters to consider when performing plyometric exercises include surface, footwear, and warm-up. This program should be performed on a surface that is firm, yet forgiving, such as a wooden gym floor. Very hard surfaces like concrete should be avoided. In addition, a cross-training or running shoe should be worn to provide adequate shock absorption as well as adequate stability to the foot. Checking wear patterns and outer sole wear will help avoid overuse injuries. Finally, an adequate warm-up should include exercises and a light cardiovascular workout.

RETURN TO SPORTS ACTIVITIES

Sports-specific drills and cutting patterns of 45° and 90° angles may be implemented, based on the patient’s athletic goals. Repeat isokinetic testing is typically performed monthly, progressing from isometric testing for the first 6 months to isokinetic testing at speeds of 180° and 300° per second. This testing not only provides the patient with feedback on performance but also serves to assist the clinician with program progression. Goals for testing should be at least 70% to begin running and 90% for full activity for the bilateral torque comparisons and approximately 60% for agonist-to-antagonist ratios. Torque-to–body weight ratios are based on age, sex, and body weight parameters.

Return to sports activities is based on successful completion of the running and functional-training program. Muscle and functional testing should be within normal limits, and a trial of function is encouraged, during which time the patient is monitored for overuse symptoms. The majority of patients who undergo meniscal transplantation have noteworthy articular cartilage deterioration and are not candidates for strenuous plyometric training or sports activities. Return to low-impact activities is therefore recommended.

Acknowledgment

The authors have no commercial relationship with any of the orthopaedic manufacturers mentioned in this chapter or shown in the figures. The manufacturers are provided for the benefit of the reader.