Non-operative management of medial meniscus posterior horn root tears is associated with worsening arthritis and poor clinical outcome at 5-year follow-up

Survivorship Analysis and Clinical Outcomes of Transtibial Pullout Repair for Medial Meniscus Posterior Root Tears: A 5- to 10-Year Follow-up Study

PURPOSE

This study investigated the clinical outcomes and mid- to long-term survival rates in patients undergoing transtibial pullout repair of medial meniscus posterior root tears (MMPRTs) after a minimum follow-up of 5 years.

METHODS

Between 2005 and 2011, patients with MMPRTs who had been followed for at least 5 years after undergoing transtibial pullout repair were recruited. Participants were identified using medical records and information in a prospectively collected database. Clinical outcomes were assessed based on a comparison of patient preoperative Lysholm scores and their scores at the final follow-up. A Kaplan-Meier survival analysis was used to investigate the survival rates of repair procedures. Clinical failures were defined as cases requiring conversion to total knee arthroplasty (TKA) or having final Lysholm score <65 or less than their preoperative scores.

RESULTS

Overall, 91 patients (mean age, 58.7 ± 9.7 years) were included: the mean follow-up duration was 84.8 ± 13.8 months. Among these patients, the mean Lysholm score improved significantly from 51.8 ± 7.9 preoperatively to 83.0 ± 11.1 at the final follow-up (P < .001). Overall, 4 patients failed due to conversion to TKA (n = 1) or having final Lysholm scores <65 or less than the preoperative scores (n = 3). The overall Kaplan-Meier probabilities of survival after repair were 99% at 5 years, 98% at 6 years, 95% at 7 years, and 92% at 8 years.

CONCLUSIONS

Among patients with MMPRTs, transtibial pullout repair demonstrated a high clinical survival rate and the patients demonstrated clinical improvement, based on mid- and long-term follow-up examinations.

LEVEL OF EVIDENCE

Level IV, retrospective uncontrolled case series.

Meniscal Extrusion Progresses Shortly after the Medial Meniscus Posterior Root Tear

Purpose

Medial meniscus posterior root tears (MMPRT) induce medial meniscus extrusion (MME). However, the time-dependent extent of MME in patients suffering from the MMPRT remains unclear. This study evaluated the extent of MME after painful popping events that occurred at the onset of the MMPRT.

Materials and Methods

Thirty-five patients who had an episode of posteromedial painful popping were investigated. All the patients were diagnosed as having an MMPRT by magnetic resonance imaging (MRI) within 12 months after painful popping. Medial meniscus body width (MMBW), absolute MME, and relative MME (100×absolute MME/MMBW) were assessed among three groups divided according to the time after painful popping events: early period (<1 month), subacute period (1–3 months), and chronic period (4–12 months).

Results

In the early period, absolute and relative MMEs were 3.0 mm and 32.7%, respectively. Absolute MME increased up to 4.2 mm and 5.8 mm during the subacute and chronic periods, respectively. Relative MME also progressed to 49.2% and 60.3% in the subacute and chronic periods, respectively.

Conclusions

This study demonstrated that absolute and relative MMEs increased progressively within the short period after the onset of symptomatic MMPRT. Our results suggest that early diagnosis of an MMPRT may be important to prevent progression of MME following the MMPRT.

Posterior Lateral Meniscus Root Reattachment With Suture Anchors: An Arthroscopic Technique

The posterior lateral meniscus root (PLMR) provides the circumferential tension required to stabilize the lateral meniscus. Thus, preservation of the PLMR is important to prevent an increase in tibiofemoral contact pressure, which could result in osteoarthritis. We describe an all-arthroscopic approach to the fixation of PLMR using suture anchors through associated posterolateral arthroscopic portals that result in a more favorable inclination of the anchors. Initially, the anatomical insertion site of the root on the tibial plateau is debrided, 1 to 2 anchors are placed through the posterolateral portals into the root's footprint area, and the meniscus is finally sutured from the posterolateral portals. Compression of the meniscus is achieved with bone contact. This technique achieves lateral meniscus root fixation, reducing the risk of subluxation of the meniscus and subsequent osteoarthritis.

Technique for Transtibial Knotless Repair of Lateral Meniscus Root Avulsion

Tear of the meniscal root results in loss of circumferential hoop tension in the meniscus and increased tibiofemoral contact pressure, leading to cartilage wear. Repair of the meniscal root can restore function of the meniscus. Many techniques for root repair have recently been described. We present a technique for root repair using a transtibial socket and knotless suture technique that can be performed through standard arthroscopy portals.

Medial Meniscus Posterior Root Repair Using a Transtibial Technique

The meniscal roots are critical in maintaining the normal shock absorbing function of the meniscus. If a meniscal root tear is left untreated, meniscal extrusion can occur rendering the meniscus nonfunctional resulting in degenerative arthritis. Two main repair techniques are described: (1) suture anchors (direct fixation) and (2) sutures pulled through a tibial tunnel (indirect fixation). Meniscal root repair using a suture anchor technique is technically challenging requiring a posterior portal and a curved suture passing device that can be difficult to manipulate within the knee. We present a technique for posterior medial meniscus root repair using 3 sutures (1 leader, 2 cinch), standard arthroscopy portals, and transtibial fixation. Overall, this technique simplifies a challenging procedure and allows for familiarity and efficiency.