Surgical Technique

Transtibial pullout meniscal root repair uses tensionable anchor

Click here to watch video of the procedure.

The medial meniscus root attachment plays an integral role in resisting hoop stresses across the tibiofemoral joint, and disruption of the posterior root has been shown to be biomechanically equivalent to a complete meniscectomy. Disruption of the medial meniscus root results in meniscal extrusion, which can alter knee kinematics and lead to progressive, rapid articular cartilage degeneration. Tears of the posterior medial root attachment are typically either traumatic or degenerative. Traumatic tears frequently occur in young patients with concomitant knee ligamentous injuries and are more frequently true avulsions of the root attachment. This is contrasted with degenerative tears that occur during low-energy injuries and are more often full-thickness radial tears located within 1 cm of the root attachment.

Shawn G. Anthony

Historically, tears of the meniscus root were treated with partial meniscectomy. However, while partial meniscectomy provided symptomatic relief in most cases of posterior medial meniscal root tears, it did not slow or halt the accelerated progression of arthritis. A variety of repair techniques have since been developed to restore meniscal anatomy and function. While there is little debate that traumatic meniscal root tears should be repaired, there are also data to support repair of degenerative root tears, especially in the setting of an older patient with otherwise preserved articular cartilage.

Zoe B. Cheung

Two types of possible repairs

A number of medial meniscal root repair techniques have been described in the literature, which involve either suture anchors or transosseous/transtibial sutures. These techniques are all performed arthroscopically to avoid open dissection of the posterior knee. Although arthroscopic repair of posterior medial meniscal root tears has demonstrated efficacious results, there is no general consensus about the optimal surgical technique. The advantage of the suture anchor technique is the use of a knot pusher to place an arthroscopic knot directly on the meniscus root, which thereby potentially allows more precise tensioning of the repair. In contrast, the transtibial pullout suture technique avoids the potential complication of suture anchor loosening, but requires a separate tibial tunnel. We present a transtibial pullout technique with a tibial anchor that allows for precise reduction and tensioning of the meniscal root repair under direct arthroscopic visualization.

Figure 1. The medial meniscal root is shown being probed and was found unstable.
Figure 2. The drill guide seen is positioned for anatomic repair of the tear.
Figure 3. A 6-mm FlipCutter is used to ream the socket.
Figure 4. Two cinch sutures are shown being placed at the root attachment.
Figure 5. The meniscus root repair is tensioned under direct arthroscopic visualization.

Source: Shawn G. Anthony, MD, MBA

Operative technique

The patient is positioned supine on the OR table where general anesthesia is induced. A standard inferolateral arthroscopy portal is made. The inferomedial portal is made immediately adjacent to the patellar tendon to provide better access to the posterior root. A diagnostic arthroscopy is performed to assess the articular cartilage and the torn medial meniscal root is probed to confirm the clinical diagnosis (Figure 1). To improve visualization, a burr can be used to perform a reverse notchplasty or to shave down the medial tibial spine. A small incision is made on the anteromedial tibia, and a meniscal root adjustable drill guide is positioned oFver the back of the tibia. The guide can be set at a 5-mm, 7.5-mm or 10-mm offset to anatomically match the root attachment position (Figure 2). A 6-mm FlipCutter (Arthrex) is used to ream a blind-ended socket to a depth of 5 mm (Figure 3). A FiberSnare suture (Arthrex) is passed up the tibial tunnel and retrieved out the anterolateral portal. A cannula is placed in the inferomedial scope portal to prevent a soft tissue bridge. A Firstpass Mini suture passer (Smith & Nephew) is used to pass two FiberLink 0 sutures (Arthrex) in cinch configuration through the posterior root of the medial meniscus (Figure 4). The tibial shuttling suture is retrieved out the inferomedial portal and used to shuttle the two repair sutures out to the anteromedial surface of the tibia. The suture limbs are loaded into a 4.5-mm Footprint Ultra PK anchor (Smith & Nephew) that is placed on the anteromedial tibial surface just distal to the drill tunnel. The suture limbs are tensioned under direct visualization of the meniscus root repair (Figure 5). The patient’s knee is cycled to remove any creep and the sutures are retensioned. Postoperatively, the patient is placed in a hinged knee brace and is non-weight-bearing for 6 weeks. Immediate range of motion is allowed to 90° of knee flexion. Physical therapy starts on postoperative day 1.

This technique provides a safe method for medial meniscal root repair that allows tensioning of the repair construct under direct arthroscopic visualization, which is useful due to the small margin of error in meniscal root repairs. A repair of the medial meniscus root that is nonanatomic by 3 mm has been shown to significantly impair the conversion of axial tibiofemoral loads into hoop stresses. Tibial pull-through techniques have traditionally been described with the use of a cortical button or suture anchor fixation on the tibia, but these do not allow retensioning, or loosening in the event of over-tensioning the meniscus after knot tying or anchor placement, respectively. The described technique provides the surgeon with maximum flexibility in obtaining the ideal position of the meniscus root at the repair site.

Increased use of transtibial repair

Transtibial pullout repair techniques have become popular for the repair of meniscal root tears. It has been proposed that tunnel drilling has the additional benefit of releasing growth factors and progenitor cells from bone marrow that enhance meniscal healing. Meniscal root repairs with a transtibial pullout technique have been shown to improve subjective patient outcomes. A systematic review by Matthias J. Feucht, MD, and colleagues demonstrated an improvement of the Lysholm score from 52 to 86 after repair. The researchers also found there was no progression of osteoarthritis on the Kellgren-Lawrence grading scale in 84% of patients after transtibial pullout meniscal root repair. Furthermore, a retrospective study by Kyu Sung Chung, MD, and colleagues comparing transtibial pullout meniscal root repair and partial meniscectomy after a minimum 5-year follow-up found a 34% conversion rate to total knee arthroplasty after partial meniscectomy compared to no conversions after meniscal root repair. Similarly, a recent retrospective study by Sang Bum Kim, MD, and colleagues comparing transtibial pullout meniscal root repair and partial meniscectomy found significantly better clinical and radiographic outcomes after meniscal root repair at a mean follow-up of 46 months. Surgical indications and management of meniscal root tears continue to evolve. The described transtibial pullout technique provides a safe and reproducible method of obtaining an anatomic repair.

Disclosures: Anthony and Cheung report no relevant financial disclosures.

Click here to watch video of the procedure.

The medial meniscus root attachment plays an integral role in resisting hoop stresses across the tibiofemoral joint, and disruption of the posterior root has been shown to be biomechanically equivalent to a complete meniscectomy. Disruption of the medial meniscus root results in meniscal extrusion, which can alter knee kinematics and lead to progressive, rapid articular cartilage degeneration. Tears of the posterior medial root attachment are typically either traumatic or degenerative. Traumatic tears frequently occur in young patients with concomitant knee ligamentous injuries and are more frequently true avulsions of the root attachment. This is contrasted with degenerative tears that occur during low-energy injuries and are more often full-thickness radial tears located within 1 cm of the root attachment.

Shawn G. Anthony

Historically, tears of the meniscus root were treated with partial meniscectomy. However, while partial meniscectomy provided symptomatic relief in most cases of posterior medial meniscal root tears, it did not slow or halt the accelerated progression of arthritis. A variety of repair techniques have since been developed to restore meniscal anatomy and function. While there is little debate that traumatic meniscal root tears should be repaired, there are also data to support repair of degenerative root tears, especially in the setting of an older patient with otherwise preserved articular cartilage.

Zoe B. Cheung

Two types of possible repairs

A number of medial meniscal root repair techniques have been described in the literature, which involve either suture anchors or transosseous/transtibial sutures. These techniques are all performed arthroscopically to avoid open dissection of the posterior knee. Although arthroscopic repair of posterior medial meniscal root tears has demonstrated efficacious results, there is no general consensus about the optimal surgical technique. The advantage of the suture anchor technique is the use of a knot pusher to place an arthroscopic knot directly on the meniscus root, which thereby potentially allows more precise tensioning of the repair. In contrast, the transtibial pullout suture technique avoids the potential complication of suture anchor loosening, but requires a separate tibial tunnel. We present a transtibial pullout technique with a tibial anchor that allows for precise reduction and tensioning of the meniscal root repair under direct arthroscopic visualization.

Figure 1. The medial meniscal root is shown being probed and was found unstable.
Figure 2. The drill guide seen is positioned for anatomic repair of the tear.
Figure 3. A 6-mm FlipCutter is used to ream the socket.
Figure 4. Two cinch sutures are shown being placed at the root attachment.
Figure 5. The meniscus root repair is tensioned under direct arthroscopic visualization.

Source: Shawn G. Anthony, MD, MBA

PAGE BREAK

Operative technique

The patient is positioned supine on the OR table where general anesthesia is induced. A standard inferolateral arthroscopy portal is made. The inferomedial portal is made immediately adjacent to the patellar tendon to provide better access to the posterior root. A diagnostic arthroscopy is performed to assess the articular cartilage and the torn medial meniscal root is probed to confirm the clinical diagnosis (Figure 1). To improve visualization, a burr can be used to perform a reverse notchplasty or to shave down the medial tibial spine. A small incision is made on the anteromedial tibia, and a meniscal root adjustable drill guide is positioned oFver the back of the tibia. The guide can be set at a 5-mm, 7.5-mm or 10-mm offset to anatomically match the root attachment position (Figure 2). A 6-mm FlipCutter (Arthrex) is used to ream a blind-ended socket to a depth of 5 mm (Figure 3). A FiberSnare suture (Arthrex) is passed up the tibial tunnel and retrieved out the anterolateral portal. A cannula is placed in the inferomedial scope portal to prevent a soft tissue bridge. A Firstpass Mini suture passer (Smith & Nephew) is used to pass two FiberLink 0 sutures (Arthrex) in cinch configuration through the posterior root of the medial meniscus (Figure 4). The tibial shuttling suture is retrieved out the inferomedial portal and used to shuttle the two repair sutures out to the anteromedial surface of the tibia. The suture limbs are loaded into a 4.5-mm Footprint Ultra PK anchor (Smith & Nephew) that is placed on the anteromedial tibial surface just distal to the drill tunnel. The suture limbs are tensioned under direct visualization of the meniscus root repair (Figure 5). The patient’s knee is cycled to remove any creep and the sutures are retensioned. Postoperatively, the patient is placed in a hinged knee brace and is non-weight-bearing for 6 weeks. Immediate range of motion is allowed to 90° of knee flexion. Physical therapy starts on postoperative day 1.

This technique provides a safe method for medial meniscal root repair that allows tensioning of the repair construct under direct arthroscopic visualization, which is useful due to the small margin of error in meniscal root repairs. A repair of the medial meniscus root that is nonanatomic by 3 mm has been shown to significantly impair the conversion of axial tibiofemoral loads into hoop stresses. Tibial pull-through techniques have traditionally been described with the use of a cortical button or suture anchor fixation on the tibia, but these do not allow retensioning, or loosening in the event of over-tensioning the meniscus after knot tying or anchor placement, respectively. The described technique provides the surgeon with maximum flexibility in obtaining the ideal position of the meniscus root at the repair site.

PAGE BREAK

Increased use of transtibial repair

Transtibial pullout repair techniques have become popular for the repair of meniscal root tears. It has been proposed that tunnel drilling has the additional benefit of releasing growth factors and progenitor cells from bone marrow that enhance meniscal healing. Meniscal root repairs with a transtibial pullout technique have been shown to improve subjective patient outcomes. A systematic review by Matthias J. Feucht, MD, and colleagues demonstrated an improvement of the Lysholm score from 52 to 86 after repair. The researchers also found there was no progression of osteoarthritis on the Kellgren-Lawrence grading scale in 84% of patients after transtibial pullout meniscal root repair. Furthermore, a retrospective study by Kyu Sung Chung, MD, and colleagues comparing transtibial pullout meniscal root repair and partial meniscectomy after a minimum 5-year follow-up found a 34% conversion rate to total knee arthroplasty after partial meniscectomy compared to no conversions after meniscal root repair. Similarly, a recent retrospective study by Sang Bum Kim, MD, and colleagues comparing transtibial pullout meniscal root repair and partial meniscectomy found significantly better clinical and radiographic outcomes after meniscal root repair at a mean follow-up of 46 months. Surgical indications and management of meniscal root tears continue to evolve. The described transtibial pullout technique provides a safe and reproducible method of obtaining an anatomic repair.

Disclosures: Anthony and Cheung report no relevant financial disclosures.