Open meniscal repair (Fig. 24-1) is the oldest technique for meniscal repair and has been popularized by Dr. Ken DeHaven.¹⁰ It has a good record of success, even at 1-year follow-up.¹¹ Open meniscal repairs are best suited for extremely peripheral tears. DeHaven still advocates routine arthroscopic evaluation before considering open repair. The arthroscope is removed from the joint and the knee is prepared. After exposing the capsule through a longitudinal incision, the surgeon prepares the meniscal rim and capsular attachment, and places vertically oriented sutures at 3- to 4-mm intervals. The incision is closed in a layered fashion. Long-term follow-up has shown success rates of 70% to 79%.^12–14

The inside-out meniscal repair technique was popularized by Henning15 in the early 1980s and is the most popular technique for meniscus repair. The surgeon uses long, thin cannulas to allow placement of vertical or horizontal sutures. After identifying the tear arthroscopically, he or she prepares the tear by using a meniscal rasp to create a better biologic environment for healing. A small posterior incision is carried down to the capsule, and sutures are placed arthroscopically using specially designed long Keith needles to pass the suture. The assistant protects the popliteal structures with a retractor while grasping the suture needles. After placing all sutures, the surgeon ties them over the capsule. Success rates have been noted to be 75% to 88%.^14,16

The outside-in meniscal repair technique allows suture placement using an 18-gauge spinal needle placed across the tear from outside the joint to inside. Absorbable polydioxanone suture17 is passed through the needle into the joint; it is secured with a mulberry knot tied to the end of the sutures. These sutures are tied to adjacent sutures at the end of the procedure over the joint capsule; separate small incisions are made for each pair of sutures. Morgan and colleagues¹⁸ noted an 84% success rate and found the primary reason for failure was an associated ACL deficiency.

All-inside meniscal repair allows the meniscus to be repaired without any additional incisions outside the knee. This is truly an all-arthroscopic technique. It is popular because it avoids additional incisions and therefore diminishes neurovascular risk and decreases operative time.14 Success rates have been noted as high as 90%.^14,19

All-inside meniscal repair can be accomplished with either suture or biodegradable “darts.²⁰” The suture technique is accomplished using a specially designed cannulated suture hook to pass suture through both sides of the tear. The sutures are then tied arthroscopically using a knot pusher.

The biodegradable darts are passed across the tear using specially designed cannulas. After preparing the torn meniscal surface, the surgeon reduces the tear and holds it in place with a cannula. A thin cutting instrument is used to make a pathway across the meniscal tear, and the biodegradable dart is passed through the same cannula, fixing the tear. The darts generally completely resorb by 8 to 12 weeks.

Ideally the patient should be seen at a preoperative visit, which includes a brief clinical evaluation to record baseline physical data and identify potential latent biomechanical deficits. The evaluation format encompasses a subjective history as outlined in Maitland,25 and objective data are gathered primarily to record baseline measurements. The lower extremity (LE) is evaluated as a functional unit. Strength and ROM are recorded for the hip, knee, ankle, and foot. Foot mechanics also are evaluated for any biomechanical faults that may lead to excessive tibial motions in the frontal or transverse planes. For example, pes planus has the potential to drive tibial internal rotation, creating a mechanism for excessive transverse friction at the knee joint. In addition, hip abduction and external rotation strength need to be examined to avoid excessive femoral adduction and internal rotation distally. Reassessment continues postoperatively with each progression of weight bearing. Girth measurements also are taken about the knee. The remainder of the preoperative visit should include instruction in proper use of crutches, education regarding ROM (heel slides with a 30-second hold for 10 repetitions), instruction in antiembolic exercises (ankle pumps with a 30-second hold for 10 repetitions), and prescription of LE strengthening exercises in the form of isometrics (quadriceps sets, hamstring sets, and cocontraction of quadriceps and hamstrings; all three exercises should be held for 10 seconds for 10 to 20 repetitions) and active range of motion (AROM) of the hip (working the adductors, abductors, and external rotators for 10 to 20 repetitions). Cryotherapy and elevation (for 15 to 30 minutes) and compression wrapping should be reviewed for postoperative pain and swelling management. Depending on individual clinic and physician preference, the patient may be instructed in the use of electrical stimulation (ES). The patient should be instructed in activities of daily living, such as bathing and dressing, as appropriate. Home exercises are to be performed three times a day until return for the initial postoperative physical therapy evaluation.

GOALS: Manage pain and swelling, increase ROM and strength, increase weight-bearing activities and prevent excessive loads/stresses through the joint surfaces (Table 24-1)

The patient is typically seen for physical therapy 4 to 7 days after surgery. He or she may complain of mild to moderate pain, swelling, impaired balance, and decreased weight-bearing tolerance. The patient may or may not be using pain medication.

Generally, patients undergoing partial or total meniscectomy may be weight bearing as tolerated immediately or soon after surgery whereas those undergoing repair are usually non–weight bearing (NWB) or partial weight bearing (PWB) with crutches for a period of 2 to 6 weeks. Noyes recommends 4 weeks of PWB for complex and avascular tears, with up to 6 weeks of toe touch weight bearing when the patient has a radial tear.²⁶ Tibiofemoral loads induce a circumferential stress (so-called “hoop stress”) in the meniscus, which would distract the radial tear margins.²⁷ Based on physician preference, the patient may have a postoperative hinged knee brace, which will either be statically locked at a particular setting for 7 to 10 days or set between certain parameters to allow for immediate postoperative ROM. Meniscal repairs in the “red-red zone” and larger peripheral repairs may be braced up to 90° for up to 14 days. “White zone” repairs may be braced at 20° to 70°. Extension is increased to 0°, and flexion is increased to 90° after 7 to 10 days as healing allows.

On the first postoperative visit a comprehensive evaluation is performed, with the physical therapist collecting the new objective data and reviewing and updating the previous subjective data.²⁵ Subjective data that need to be reviewed postoperatively include medication usage, sleep pattern, pain levels at rest and during activity, and aggravating and easing factors. In addition, the therapist should review the postoperative report dictated by the operating surgeon that describes the extent and nature of the repair, as well as any unique patient-specific postoperative instructions. Goals and rehabilitation expectations are established and reviewed with the patient during the initial visit.

The new and updated objective and clinical data should include visual examination, gait assessment, ROM measurement, strength assessment, palpation, and girth measurement (as described in the section on the preoperative initial visit). Visual observation should focus on areas of atrophy, in particular the quadriceps and gastrocnemius; healing status of incision sites; and swelling about the knee joint and distal LE. Depending on the patient’s weight-bearing status or tolerance, gait assessment is either brief or detailed. Gait assessment should focus on proper mechanics and weight-bearing tolerance. If the patient is NWB or PWB, the assessment is brief and focuses primarily on safety, correct mechanics (with crutches), and includes a discussion regarding weight-bearing restrictions. If the patient does not have weight-bearing limitations and has good gait tolerance, then a more detailed assessment of gait can be made. The patient’s ability to ambulate with normal mechanics throughout each phase of gait is very important and should be assessed. Remedial corrective actions are required to decrease potentially harmful loading onto healing structures. Typically patients require cueing to avoid hip external rotation during the stance phase, because this puts abnormal stresses through the knee, ankle, and foot. Crutches should be used throughout the initial phase of treatment until adequate strength, ROM, and normal gait mechanics are achieved. Static and dynamic foot function (as related to normal gait mechanics) continues to be assessed during this phase of rehabilitation. Dysfunctions must be addressed to decrease abnormal tensile or compressive force affecting healing of the meniscus repair.

Flexibility of the hip musculature, hamstring, and gastrocnemius-soleus complex should be assessed. The patellofemoral joint should be assessed, especially if the patient reports previous or present patella symptoms. Patella tracking and glides are part of this assessment. Joint mobilization or patellofemoral taping may be helpful in mitigating these symptoms.²⁸ All major muscle groups in the LE should be assessed bilaterally for strength capacity. In addition, visible observation and palpation of the quadriceps during an isometric quad set or straight leg raise (SLR) can give the clinician insight into the patient’s ability to be safe and secure in an upright position. The remaining LE musculature should be assessed, with the therapist identifying any potential weakness that may alter normal closed kinetic biomechanics and therefore increase tensile or compressive forces across the meniscus repair site.

No standard method has been established for assessing girth about the knee joint. Consistency among the team members providing patient care is important when reassessing the patient’s condition. Atrophy as measured by girth measurements is not diagnostic of weakness or atrophy in a specific muscle group. Circumference measurement assesses girth of all muscle and joint structures underlying the measurement area. Typical measurement sites for a bilateral comparison include the midpatella, 5 and 10 cm above the knee joint and 5 and 10 cm below the knee joint.

Treatment is initiated after the clinical evaluation is completed (see Table 24-1). Initial phase treatment goals are to decrease pain and manage swelling, restore ROM, increase muscle strength and endurance, and normalize gait within healing and weight-bearing limitations.

Range of Knee Motion and Flexibility

Restoration of ROM is vital to a return to the patient’s prior level of function. Typically on initial evaluation, the patient exhibits a loss of extension of 5° to 10°; flexion ROM is typically 70° to 90°. The patient usually exhibits a guarded end feel with motion improving with repetition. The time parameter to achieve full ROM is longer with meniscal repair than it is in partial arthroscopic meniscectomies. Although early restoration of ROM is important to normalize joint function, the healing process of the meniscus repair dictates caution, especially with full circumferential peripheral repairs.

Any exercises used to increase ROM should not be forced because of the risk of stressing healing repair sites. Wall slides, sitting passive knee flexion, or passive heel slides (Fig. 24-2) may be used to increase knee flexion. ROM exercises are to be performed within pain tolerance, held at least 30 seconds, and repeated as tolerated (generally 5 to 10 times). As part of the home exercise program, ROM activity can be repeated three to five times per day.

Appropriate remedial flexibility exercises can be implemented as tolerated in this phase, with the patient avoiding forced knee flexion and rotation about the knee joint. Patients should perform slow static stretches, avoiding ballistic movements, to maintain control of the lower limb and minimize the chance of affecting the healing meniscus repair.^32,33 Hamstring and gastrocnemius-soleus flexibility exercises are typically indicated at this time. Stretches should be held at least 30 seconds and repeated 5 times, three times a day. Stretches should be sustained and passive in nature, allowing the patient or therapist to control knee joint motions, avoiding potential complications from ballistic type of stretching.³⁴ The hamstring group can be stretched passively using supine position. A towel can be used to assist with the raising of the leg (Fig. 24-3). The gastrocnemius-soleus can be stretched using a towel or strap in the early phases of rehabilitation. Progression to stretching of the hip musculature and quadriceps can be performed as the patient’s increase in knee ROM dictates. The knee needs to be kept in a relative neutral position to avoid any rotational or compressive forces on the repaired meniscus site. Standing gastrocnemius-soleus stretching can be initiated as weight-bearing tolerance increases.