Medial Meniscus Posterior Root Reconstruction and Open-Wedge High-Tibial Osteotomy for Medial Meniscus Posterior Root Tear With Varus Knee Alignment: A Retrospective Study on Short-Term Outcomes

Abstract

Purpose: We describe 13 cases of medial meniscus posterior root tear (MMPRT) with varus knee alignment treated with medial meniscus posterior root reconstruction (MMPR-R) and open-wedge high-tibial osteotomy (OWHTO) to identify an optimal MMPRT treatment.

Methods: We retrospectively reviewed 13 patients (mean age: 66.3 ± 8.0 years) who underwent MMPR-R and OWHTO. The Knee Injury and Osteoarthritis Outcome Score (KOOS), femorotibial angle (FTA), percentage mechanical axis (%MA) on radiography, and medial meniscus extrusion (MME) on magnetic resonance imaging (MRI) between the preoperative period and last follow-up were compared. Moreover, meniscus healing status and the International Cartilage Repair Society (ICRS) classification of the medial femoral condyle and medial tibial plateau on arthroscopy between the initial surgery and second-look arthroscopy were compared.

Results: The mean follow-up duration was 12.8 ± 2.2 months. At the last follow-up, the KOOS significantly improved (P < 0.01). Based on the FTA and %MA, the varus alignment was predominantly corrected at the last follow-up (P < 0.01). The MME was increased in nine (62.9%) patients, and the mean MME significantly increased at the last follow-up (P = 0.04). Second-look arthroscopy revealed improvements in the ICRS grade for the medial femoral condyle and medial tibial plateau in six (46.2%) patients. However, the results did not significantly differ. Regarding meniscus healing, four (30.8%) patients presented with complete healing, eight (57.1%) with partial healing, and one (7.7%) with failed healing.

Conclusions: The MMPRT with varus knee alignment significantly improved with MMPR-R and OWHTO. However, the MME and meniscus healing were unsatisfactory.

Keywords: knee; medial meniscus posterior root reconstruction; medial meniscus posterior root tear; meniscus tear; open-wedge high-tibial osteotomy; osteoarthritis.

Figure 1. Diagnosis of MMPRT

An arthroscopic image of the left knee; MMPRT was confirmed using a probe. MFC: medial femoral condyle; MM: medial meniscus; MMPRT: medial meniscus posterior root tear

Figure 2. Creation of a soft tissue tunnel

An arthroscopic image of the left knee; a soft tissue tunnel was created at the MM periphery approximately 5 mm from the medial meniscus posterior root tear edge (blue arrow) using a 3.5-mm 90°electrode (Mitek VAPR 3 System). MFC: medial femoral condyle; MM: medial meniscus

Figure 3. Insertion of the guide pin into the tibial tunnel

An arthroscopic image of the left knee; a guide pin was inserted into the tibial tunnel using an anterior cruciate ligament reconstruction guide (3M). MFC: medial femoral condyle; MM: medial meniscus; MTP: medial tibial plateau

Figure 4. Creation of a tibial tunnel

An arthroscopic image of the left knee; after creating a tibial tunnel with a 4.5-mm diameter drill via the guide pin, the articular surface was enlarged with a 6.0-mm retrograde drill (AI-drill). MFC: medial femoral condyle; MM: medial meniscus; MTP: medial tibial plateau

Figure 5. The passing of the graft through the soft tissue tunnel

An arthroscopic image of the left knee; the graft was passed through the soft tissue tunnel. MFC: medial femoral condyle; MM: medial meniscus; MTP: medial tibial plateau

Figure 6. The passage of the graft into the tibial tunnel

An arthroscopic image of the left knee; the graft was pulled out into the tibial tunnel and then fixed using an artificial ligament fixture (pull-out button, AI-Medic). MFC: medial femoral condyle; MM: medial meniscus; MTP: medial tibial plateau

Figure 7. Postoperative plain radiography

(a) frontal view; (b) lateral view