Setup
Following induction of either spinal or general anesthesia, the patient is positioned supine on the operating table and appropriate prophylactic antibiotics are administered. A sandbag is taped to the table, and a lateral post is placed at the level of the mid-thigh to support the extremity with the knee at 90° of flexion (Fig. 2). The entire procedure is done with the knee in this position; we do not use a leg holder or a tourniquet.
An evaluation with the patient under anesthesia is performed to assess knee range of motion and stability. Before preparation and draping, surface landmarks and the planned incisions are drawn. The portals include standard anterolateral and anteromedial parapatellar arthroscopic portals, a superolateral outflow portal, and a posteromedial portal. A 3-cm incision is drawn on the flare of the anterolateral aspect of the proximal part of the tibia, distal to the Gerdy tubercle and proximal to the origin of the tibialis anterior muscle. The incision runs from proximal and lateral to distal and medial along the skin lines (Fig. 3). The knee is then prepared with Betadine (povidone-iodine), and the joint and incision areas are injected with 1% lidocaine with epinephrine (1:100,000). The involved extremity is then prepared and draped in the usual sterile fashion.
Diagnostic Arthroscopy
The arthroscope is placed in the anterolateral portal, and a thorough diagnostic arthroscopy is performed with a probe placed through the anteromedial portal. Care is taken to evaluate all three compartments throughout the full range of motion in search of any injury not appreciated on magnetic resonance imaging. Any loose bodies or unstable articular cartilage lesions are addressed at this time.
A thorough investigation of the menisci is crucial, as a medial meniscal root tear may be difficult to appreciate arthroscopically and the meniscus may appear normal on initial inspection. To visualize the posteromedial joint space, the 30° or 70° arthroscope is gently positioned under the posteromedial bundle of the posterior cruciate ligament, along the lateral aspect of the medial femoral condyle (the Gillquist view). This position allows for excellent visualization of the posterior horn of the medial meniscus and the root insertion (Fig. 4). Once the diagnosis of the root tear is confirmed and the tissue is found to be amenable to repair (good quality remaining tissue with minimal retraction), a posteromedial portal is also created under direct visualization. With the knee flexed to 90°, the cutaneous entry point is located approximately 10 mm proximal to the tibiofemoral joint space and 5 mm behind the posterior edge of the femoral condyle. A spinal needle is inserted percutaneously at this entry point under arthroscopic visualization from the posteromedial joint space. Once the appropriate position is confirmed, a vertical incision is made with a number-11 blade through the skin, subcutaneous tissues, and capsule. A switching stick is placed into the posteromedial joint space through this portal.
Exposure of the Root Tear and Insertion
The first step in the repair of the root tear is the establishment of adequate exposure of the meniscus and its insertion on the posterior tibial plateau. We perform a reverse notchplasty of the posterior medial femoral condyle with a 4.5-mm full radius resector. The shaver, which is placed in the anteromedial portal while being viewed from the anterolateral portal, is used to débride synovium, a minimal amount of the undersurface of the posteromedial bundle of the posterior cruciate ligament, and 3 to 5 mm of articular cartilage from the medial femoral condyle (Figs. 5-A, 5-B, and 5-C). This reverse notchplasty is essential for visualization, repair-bed preparation, tunnel positioning, and eventual root fixation.
Following the reverse notchplasty, the quality of the meniscal tissue is reevaluated and the insertion of the root is identified. With the arthroscope in the posteromedial portal and the curved shaver or the meniscal rasp in the anterolateral portal, the insertion site on the tibia is roughened (Fig. 6). It is important to prepare a broad tibial insertion site to bleeding bone. Often, small fat globules may emanate from the osseous surface as it is prepared with the rasp.
Suture Passage
Once the insertion site has been prepared, suture passage is performed. The equipment for suture passage is shown in Figure 7. A suture shuttle with a monofilament suture loop is utilized. A clear 8-mm cannula is placed in the anterolateral portal to simplify suture control and suture passage. With the arthroscope in the anteromedial portal and the suture shuttle placed through the cannula in the anterolateral portal, the meniscal root is pierced from the undersurface to the superior surface with the suture shuttle tip (Figs. 8-A through 8-F). The monofilament loop is passed through the meniscal root. The suture shuttle is removed from the joint, while the loop is maintained in its position through the root. The loop is then grasped and pulled out of the joint through the cannula in the anterolateral portal. The free ends of the monofilament must be held outside the cannula to prevent their advancement into the joint. One end of a number-2 nonabsorbable braided suture is threaded through the monofilament loop, and the ends are made equal in length. The free ends of the monofilament are pulled to shuttle the braided suture loop through the meniscus and back out of the anterolateral portal of the knee. Again, care is taken to not allow the free ends of the suture to enter the knee. Once the suture loop is outside the anterolateral portal, the free suture ends are passed through the suture loop. The loop is then advanced down onto the root of the meniscus, resulting in a tight loop stitch around the meniscus. To facilitate loop passage, a pulley probe may be used as a fulcrum to prevent the suture from cutting through the tissue. The free suture ends are left resting through the anterolateral portal while the tunnel is prepared.
Tunnel Preparation
With the arthroscope in the posteromedial portal, a standard anterior cruciate ligament transtibial guide is placed through the anterolateral portal, over the anterior cruciate ligament, and onto the root insertion. The tip of the guide is positioned at the anatomic insertion of the meniscal root. The drilling sleeve is placed through the guide, and its position on the skin is marked. At this position, the previously described anterolateral incision is made and dissection is carried down to the anterior compartment fascia and periosteum (Figs. 9-A through 9-D). Care is taken not to violate the anterior compartment of the leg as substantial bleeding may be encountered. The superomedial edge of the anterior compartment fascia and periosteum are incised, and 4 cm of the anterior compartment is elevated off the anterolateral tibial surface, just distal to the lateral flare of the tibia. Exposure of the tibia is complete when there is ample osseous surface to allow for placement of a fixation screw and washer. With the arthroscope still in the posteromedial portal, the anterior cruciate ligament guide-tip is reintroduced through the anterolateral portal onto the previously identified position at the meniscal root insertion site. The anterior cruciate ligament drill-sleeve is placed through the incision onto the exposed flare of the lateral aspect of the tibia. Under arthroscopic visualization, the 3/32-in (2.4-mm) guide-pin is drilled. We recommend drilling only to the far cortex with use of power and completing the tunnel manually by tapping the guide-pin through the posterior cortex.
Tear Fixation
The guide-pin is removed and, in its place, a Hewson suture passer is passed through the tibial tunnel into the knee. With the arthroscope in the anteromedial portal, the Hewson suture-passer loop is brought into the anterior aspect of the knee. With use of arthroscopic ice tongs placed through the loop, the braided suture is grasped and passed through the Hewson suture-passer loop. Facilitated by an arthroscopic pulley probe, the Hewson suture passer is then pulled back through the tunnel, bringing the sutures with it (Figs. 10-A through 10-D). With firm tension on the sutures, reduction of the meniscus can be visualized arthroscopically. The final step in the repair is to tie down the suture ends onto the lateral aspect of the tibia over a button or a 6.5-mm cancellous screw with washer. This fixation is performed with the knee at 30° of flexion to help with reduction of the meniscus. Closure of the reflected anterior compartment fascia and periosteum is performed with number-0 absorbable, synthetic, braided sutures. The skin is closed in the usual fashion.
The steps in the repair are depicted in Figures 11-A through 11-G.
The principles of the postoperative protocol are based on the belief that soft tissue requires six weeks to heal to bone. Our postoperative protocol is to maintain the patient on partial weight-bearing for six weeks. Walking is then advanced to full weight-bearing by eight weeks. A continuous-passive-motion (0° to 90°) machine is utilized for four weeks, and bracing is optional. Physical therapy during the first month is self-administered and consists of straight-leg raises, quadriceps sets, heel slides, and calf pumps. During the second and third months, we utilize supervised physical therapy. Full activity is usually resumed by three to four months.
INDICATIONS:
Symptomatic, isolated medial meniscal root tear with minimal arthritis (no joint-space narrowing, subchondral cysts, or osteophytes).The patient has failed conservative management, and the injury is affecting the activities of daily living.
Symptomatic, isolated medial meniscal root tear with minimal arthritis (no joint-space narrowing, subchondral cysts, or osteophytes).
The patient has failed conservative management, and the injury is affecting the activities of daily living.
CONTRAINDICATIONS:
Medial joint-space narrowing and/or Fairbanks changes on flexion weight-bearing radiographs.Asymmetric varus alignment (>3°) and medial joint-space narrowing on long-cassette radiographs. (In these patients, we recommend an osteotomy or unicompartmental arthroplasty.)Diffuse grade-3 to 4 changes, according to the system of the International Cartilage Repair Society (), in the femoral condyle or tibial plateau articular cartilage identified arthroscopically at the time of surgery. (In these patients, we recommend an osteotomy or unicompartmental arthroplasty at a later setting.)
Medial joint-space narrowing and/or Fairbanks changes on flexion weight-bearing radiographs.
Asymmetric varus alignment (>3°) and medial joint-space narrowing on long-cassette radiographs. (In these patients, we recommend an osteotomy or unicompartmental arthroplasty.)
Diffuse grade-3 to 4 changes, according to the system of the International Cartilage Repair Society (), in the femoral condyle or tibial plateau articular cartilage identified arthroscopically at the time of surgery. (In these patients, we recommend an osteotomy or unicompartmental arthroplasty at a later setting.)
PITFALLS:
Patient selection.— Failure to acknowledge underlying degenerative changes or malalignment.— Failure to recognize patellofemoral or lateral compartment articular cartilage changes.Surgical technique— Inadequate arthroscopic visualization makes repair-bed preparation, suture passage, and fixation challenging. (Exposure is facilitated with a reverse notchplasty.)Inability to obtain arthroscopic suture fixation— Retracted root tears, especially those in the chronic setting, that are not easily reducible to the insertion site may not be amenable to repair.— An insufficient amount of the root tissue captured in the repair suture, which may be caused by abnormal anatomy or a degenerative meniscal tissue, may lead to limited insertion site coverage with reduction.
Patient selection.— Failure to acknowledge underlying degenerative changes or malalignment.— Failure to recognize patellofemoral or lateral compartment articular cartilage changes.
— Failure to acknowledge underlying degenerative changes or malalignment.
— Failure to recognize patellofemoral or lateral compartment articular cartilage changes.
Surgical technique— Inadequate arthroscopic visualization makes repair-bed preparation, suture passage, and fixation challenging. (Exposure is facilitated with a reverse notchplasty.)
— Inadequate arthroscopic visualization makes repair-bed preparation, suture passage, and fixation challenging. (Exposure is facilitated with a reverse notchplasty.)
Inability to obtain arthroscopic suture fixation— Retracted root tears, especially those in the chronic setting, that are not easily reducible to the insertion site may not be amenable to repair.— An insufficient amount of the root tissue captured in the repair suture, which may be caused by abnormal anatomy or a degenerative meniscal tissue, may lead to limited insertion site coverage with reduction.
— Retracted root tears, especially those in the chronic setting, that are not easily reducible to the insertion site may not be amenable to repair.
— An insufficient amount of the root tissue captured in the repair suture, which may be caused by abnormal anatomy or a degenerative meniscal tissue, may lead to limited insertion site coverage with reduction.
AUTHOR UPDATE:
The original technique was an open technique through a posteromedial approach with use of a Bunnell stitch. This open technique was similar to the method performed in our cadaver study3. A recent biomechanical study that evaluated open and arthroscopic meniscal root fixations demonstrated that the arthroscopic technique is as biomechanically effective as the open technique5. In addition, the arthroscopic development of a reverse notchplasty and the use of the posteromedial portal have substantially improved visualization and instrument access for repair. Therefore, we currently utilize the arthroscopic technique as outlined in this report. Our experience suggests that patients have been satisfied with the result of this technique. To date, none of our patients who underwent this procedure have needed a conversion to an osteotomy or arthroplasty.