Managing a Medial Meniscal Tear in an Active 52-Year-Old Male
A healthy, active, 52-year-old male patient presents with left knee pain after a skiing injury. MRI demonstrates a tear of the medial meniscus, possibly involving the medial meniscal root. What is the next step in treating this patient?
Brandon J. Erickson, MD
Meniscal tears are one of the most common knee injuries seen by orthopaedic surgeons. Often the result of a twisting mechanism, meniscal tears can cause pain, mechanical symptoms (locking, clicking, catching), swelling, and occasional feelings of instability. Although there are many variants of meniscal tears, including horizontal cleavage, radial split, parrot beak, and others, one of the variants that has become increasingly recognized are tears of the meniscal root, specifically the posterior root.
The menisci are C-shaped pieces of cartilage that have several functions, including joint lubrication, knee stability, and proprioception. However, one of the most important functions of the meniscus is to dissipate joint loads by converting the loads to hoop stresses. This essentially decreases the stress on the medial and lateral femoral condyles and tibial plateaus, thereby protecting the chondral surfaces from increased wear.
To properly function and dissipate these joint forces, the meniscus must have secure attachments from the posterior meniscal root to the tibia. Violation of the root attachments allows extrusion of the meniscus from the joint, which increases stress on the chondral surfaces and can ultimately lead to accelerated joint degeneration. [1-3]
In a cadaveric study, Marzo and Gurske-DePerio  evaluated the tibiofemoral contact pressures and contact area in 8 knees. They measured these variables 3 times: in the intact medial meniscus (control state), following avulsion of the posterior horn of the medial meniscus, and following meniscal repair through a transosseous tunnel.
They found a significant increase in tibiofemoral contact pressure and contact area when the posterior horn of the medial meniscus was avulsed compared with the intact meniscus. However, once the meniscus was repaired, the tibiofemoral contact pressures and contact area were equal to the control state, indicating that repair of the meniscal root returned function to the meniscus. 
The surgeon has several options for treatment of meniscal root tears, including non-operative and operative interventions. Non-operative intervention is often reserved for unhealthy patients, chronic and degenerative tears, patients with significant arthritis (Outerbridge Grade III or IV), or knees with varus malalignment. Operative intervention can include either a meniscal root repair or partial meniscectomy.
In a knee with relatively well-preserved joint space and cartilage surfaces, meniscal root repair is recommended to restore meniscal function and possibly prevent accelerated joint degeneration. Meniscal root repair can be performed via several techniques, including the transtibial pullout technique and suture anchor repair technique.  The transtibial pullout technique is the author’s preferred technique.
A 52-year-old male presented 1 week after injuring his left knee while skiing. He did not remember a specific incident in which he twisted the knee, but after a day of skiing, he had a significant increase in pain and swelling in the knee. Over the next few days, he noticed a click that was present in the knee that had not been there in the past.
Although he previously had occasional episodes of pain in the knee, he reported that this pain felt different and more significant. He denied any other knee injuries, and he had no history of prior surgeries or recent injections in either knee.
His main complaints at his visit were pain and clicking in the knee, as well as pain with rotational maneuvers such as changing directions on the knee. He is an avid skier in the winter months and also plays recreational sports. His goal is to be able to return to skiing and recreational sports.
- Height: 6 feet, 2 inches; weight: 215 pounds; BMI: 27.6kg/m2
- Mild swelling present on inspection
- Full range of motion (ROM)
- Knee stable on ligamentous exam
- Tenderness to palpation at the medial joint line
- No tenderness at the lateral joint line
- Some discomfort with a McMurray test, but no click
- Pain with a Thessaly test
- Neurovascularly intact distally
Figures 1a-d. Radiographs of the left knee show no acute osseous abnormalities. The joint space is well maintained.
Figure 2a-e. MRI of the left knee demonstrates well–maintained articular surfaces with a tear in the posterior aspect of the medial meniscus. There is evidence of slight extrusion of the medial meniscus on the coronal slices,  a truncation sign on the coronal images,  and a “ghost sign” of the medial meniscus on the sagittal images.
- Medial meniscal root tear
A long discussion with the patient ensued. The options presented to the patient included:
- Non-operative treatment: Rest, potentially a one-time steroid injection, and physical therapy
- Operative treatment: Surgical repair of the meniscal root versus possible meniscectomy
We discussed the nature of the surgery and the associated risks, including failure of the repair to heal, stiffness, neurovascular injury, and wound complications, as well as the postoperative recovery and rehabilitation protocol. The patient communicated his understanding of the risks and the decision was made to proceed with surgical repair. He also understood that a meniscectomy would be performed instead of a meniscal root repair if the meniscal tissue was degenerative and not repairable at the time of surgery.
Procedure: Transtibial Pullout Technique
- The patient received a nerve block as well as sedation.
- He was then positioned supine on the operating room table. A sequential compression device was placed on the contralateral leg to help with mechanical prophylaxis of deep vein thrombosis.
- An exam under anesthesia demonstrated full ROM of the left knee with a significant click.
- The patient was then prepped and draped in the usual sterile fashion
- An inferolateral arthroscopy portal was created and the arthroscope was atraumatically introduced into the knee.
- Diagnostic arthroscopy demonstrated well-preserved cartilage surfaces, no loose bodies, and no lateral compartment or notch pathology.
- An anteromedial portal was established under direct spinal needle localization.
- The medial compartment demonstrated a tear at the posterior medial meniscal root with relatively good meniscal tissue (Figure 3a).
Figure 3a. Tear at the posterior medial meniscal root in the medial compartment.
- Given the limited chondral wear and good meniscal tissue, the decision was made to proceed with meniscal repair.
- Because the medial compartment was tight, an 18-gauge spinal needle was used to pie crust the medial collateral ligament (MCL). Studies have shown no increased valgus laxity following this technique, which often provides much-needed space to avoid chondral injury throughout the remainder of the procedure. [6,7]
- A soft, flexible silicone catheter with low-profile flanges (PassPort Cannula, Arthrex; Naples, Florida) was then placed through the inferomedial portal to facilitate suture passage and management.
- A meniscal root repair drill guide was placed through the inferomedial portal and a skin incision was made off the medial tibial crest where the bullet contacts the skin.
- Dissection was taken down to bone.
- The drill guide was positioned so that the drill would exit at the insertion of the meniscal root (Figure 3b). Care was taken to avoid breaking into the joint too anteriorly. In cases of some loss of meniscal tissue, the exit point of this drill hole is adjusted to avoid over-tensioning the meniscus.
Figure 3b. Drill guide positioned so that the drill would exit at the insertion of the meniscal root.
- A reamer was used to create the tibial tunnel, and a retrograde reamer was used to create a healing surface for the meniscus by reaming back approximately 5 mm (Figure 3c).
Figure 3c. A reamer was used to create the tibial tunnel and a retrograde reamer was used to create a healing surface for the meniscus.
- The drill sleeve was malleted slightly into the tibia to maintain position while the drill was removed and a passing suture (Fiberstick, Arthrex; Naples, Florida) was placed through the tibial tunnel and retrieved out of the inferomedial portal.
- The tails of the suture were maintained out of the tibial tunnel and the loop was retrieved out of the inferomedial portal. This suture was placed aside for later shuttling (Figure 3d).
Figure 3d. The tails of the passing suture were maintained out of the tibial tunnel and the loop was retrieved out of the inferomedial portal.
- A suture-passing device (Knee Scorpion Suture Passer; Arthrex; Naples, Florida) was used to pass high-tensile suture through the meniscal tissue (Figure 3e-f). The number of sutures passed depends on the tissue quality and tear configuration, although 2 or 3 sutures is generally adequate (Figure 3g).
Figure 3e–f. High-tensile suture was passed through the meniscal tissue using a suture-passing device.
Figure 3g. Two or 3 sutures are typically used to repair the medial meniscal root tear.
- The suture choice and configuration can vary based on surgeon preference. Studies have evaluated various suture configurations (2 simple sutures, 1 inverted mattress suture, 1 double-locking loop suture, and 2 double-locking loop sutures) and found that the double-locking loop suture repair had significantly higher failure loads compared with the other configurations. 
- Once all sutures had been passed, the sutures were shuttled out of the tibial tunnel. Tension was maintained on the sutures to reduce the meniscus to the tibial plateau (Figure 3h).
Figure 3h. The sutures were shuttled out of the tibial tunnel, with tension maintained to reduce the meniscus to the tibial plateau.
- A microfracture awl was then used to microfracture the notch to stimulate an intra-articular healing response.
- Once the slack had been removed from all sutures, the knee was placed into 30° of flexion and the sutures were secured to the tibia. This can be done with a suture anchor or button. We used a 4.75-mm SwiveLock anchor (Arthrex; Naples, Florida).
- The incision was copiously irrigated and then closed in a layered fashion.
- A hinged knee brace locked in extension was placed on the leg and the patient was taken to the recovery room.
Postoperative Follow Up
The goal of the first 6 weeks of recovery is to allow the meniscus to heal down to bone. Following is the postoperative protocol the author has found to be effective. Patients should understand that it will take 6 months or more of recovery before they are at their optimal level. Some patients may progress faster, while others may be slower, but this is a general guideline.
- Non-weight-bearing with the brace locked in extension
- Brace locked in extension while sleeping for 2 weeks
- Can begin active and passive ROM from 0° to 90°
- Quadriceps sets and straight leg raises permitted, as is patellar mobilization
- Begin to progress to weight-bearing; full weight-bearing by 6 weeks
- Progress to full ROM
- As quadriceps function returns, brace can be unlocked during weight-bearing
- No weight-bearing with the brace unlocked past 90° until week 6
- Discontinue brace when quadriceps strength is adequate
- Heat before and ice after physical therapy
- Weight-bearing as tolerated without brace
- Begin stationary bike
- Full ROM
- Begin closed chain exercises
- Lunges and leg press are allowed from 0° to 90°
- Continue strengthening exercises
- Single leg strengthening permitted
- Can begin jogging at 3 to 4 months and progress to running
- Begin sport-specific training (if applicable)
- Return to sport at 6 months, if adequate strength and proprioception
- Proper visualization and protection of the chondral surfaces are paramount in this case. Pie crusting the MCL can improve visualization and minimize cartilage injury without significant morbidity.
- The exit point for the drill into the tibial plateau is critical to allow proper tensioning of the meniscus. Ensure the drill guide is properly set so that it exits the tibial plateau at the site where the meniscal tissue should contact the tibial plateau.
- A cannula placed in the inferomedial portal will facilitate suture passage and avoid unnecessary tissue bridges when shutting sutures.
- Avoid over- or under-constraining the meniscus by securing the meniscus with the knee in 30° of flexion.
Meniscal root tears have become an increasingly recognized injury with significant consequences if not treated appropriately. In the case presented in this article, the patient was young and active, with a well-preserved medial compartment and an isolated tear of the posterior medial meniscal root that led to meniscal extrusion. The goal of repair was restoration of meniscal function (ie, ability to dissipate joint stress by restoring hoop tension) with, if possible, prevention of long-term meniscal extrusion and medial compartment degeneration.
Several biomechanical studies have evaluated the effect of meniscal root tears on joint contact pressures and have reported on the effect of meniscal root repair in restoring meniscal function. [1,4] Allaire et al  performed a biomechanical study to test 4 meniscal conditions in 9 cadaveric knees: (1) knees with an intact meniscus, (2) knees with a posterior root tear of the medial meniscus, (3) knees with a repaired posterior root tear, and (4) knees with a total medial meniscectomy. They recorded contact pressure and contact area for each testing condition.
The results showed that medial meniscal posterior root tear caused a 25% increase in peak contact pressure compared with the intact knee. Repair of the root tear restored the peak contact pressure to normal. Furthermore, there was no difference in peak contact pressure between knees after total medial meniscectomy and knees with a meniscal root tear. As such, this study demonstrated that a medial meniscal root tear caused the knee to function like a knee that had been meniscectomized, but when the tear was fixed, the meniscus functioned similar to its intact state. 
Outcomes following medial meniscal root repair have been encouraging, although the number of studies reporting mid- and long-term outcomes are limited. [9-12] Moon et al  reported imaging and clinical outcome scores for 63 patients who underwent isolated arthroscopic medial meniscal root repair with the transtibial repair. They divided patients into 2 groups according to the change in medial meniscal extrusion at 1 year postoperatively compared with preoperatively. They found significant improvement in clinical outcome scores in the overall patient cohort. When patients with and without an extruded meniscus were compared, the investigators saw a significant reduction in progression to osteoarthritis in the group in which the meniscus was not extruded. However, there was some progression of osteoarthritis in both groups. 
Similarly, Chung et al  compared the results of medial meniscal root repair versus meniscectomy in patients with posterior horn meniscal root tears and a minimum of 5 years of follow-up. They found significant improvement in clinical outcome scores and progression of medial joint space narrowing in both groups. However, the medial meniscal root repair group had significantly better clinical outcome scores and significantly less progression of arthritis compared with the meniscectomy group. 
Hiranaka et al  reported the results of 68 patients who underwent isolated meniscal root repair using 2 separate suture configurations (2 simple stitches versus modified Mason-Allen suture). At 1 year after surgery, they performed a second-look arthroscopy to evaluate for progressive cartilage changes and meniscal healing. They found significant improvement in all clinical outcome scores, with no significant difference in clinical outcome scores or meniscal healing status between the 2 groups. More importantly, there was no significant progression of cartilage damage in either group. 
LaPrade et al  reported clinical outcomes in 49 patients who underwent medial meniscal root repair and who had a minimum of 2 years of follow-up. They found significant improvement in all clinical outcome scores, with no difference between patients younger than age 50 and patients over age 50. There were 3 revisions in the cohort, all in patients under age 50. 
Although more work still needs to be done, the results following posterior medial meniscal root repair are encouraging. As such, patients should be considered for a meniscal root repair if they have relatively well-preserved joint space and reasonable meniscal tissue and can comply with the rehabilitation program.
Brandon J. Erickson, MD, is an orthopaedic sports medicine and shoulder surgeon at The Rothman Institute, New York, New York. He is also Sports Medicine Section Editor for Rothman Institute Grand Rounds.
Disclosures: Dr. Erickson has no disclosures relevant to this article.
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- Hiranaka T, Furumatsu T, Miyazawa S, et al. Comparison of the clinical outcomes of transtibial pull-out repair for medial meniscus posterior root tear: Two simple stitches versus modified Mason-Allen suture. Knee. 2020;27(3):701-708.
- LaPrade RF, Matheny LM, Moulton SG, James EW, Dean CS. Posterior meniscal root repairs: outcomes of an anatomic transtibial pull-out technique. Am J Sports Med. 2017;45(4):884-891.
- Moon HS, Choi CH, Jung M, Lee DY, Hong SP, Kim SH. Early surgical repair of medial meniscus posterior root tear minimizes the progression of meniscal extrusion: 2-year follow-up of clinical and radiographic parameters after arthroscopic transtibial pull-out repair. Am J Sports Med. 2020;48(11):2692-2702.