Arthroscopic partial meniscectomy of a posteriorly flipped superior leaflet in a horizontal medial meniscus tear using a posterior transseptal portal

Intrasubstance degeneration of medial meniscus horizontal cleavage tear in young patients is associated with increased joint line obliquity in the coronal plane of the knee

PURPOSE

To evaluate the effect of joint line obliquity of the knee on intrasubstance degeneration of isolated medial meniscus horizontal cleavage tear (HCT) in young patients.

METHODS

Sixty knees of 50 patients aged < 40 years (mean age, 33.3 ± 5.5 years old), who underwent arthroscopic partial meniscectomy (APM) for HCT, were retrospectively reviewed. The radiologic parameters of alignment, including mechanical hip-knee-ankle (mHKA) angle, posterior tibial slope, and joint line obliquity, were measured on preoperative long-standing whole-leg radiographs. The patients were classified into two groups, simple horizontal type (type 1) and complicated type (type 2), according to the presence of diffuse intrasubstance degeneration of the meniscus on preoperative magnetic resonance imaging. The risk factors for intrasubstance degeneration of HCT were analyzed using multiple logistic regression analysis. Medial joint space width (JSW) on weight-bearing 45° flexion posteroanterior radiographs and the mHKA were measured to evaluate the radiographic outcomes. The clinical outcomes were evaluated using the modified Lysholm score. Among patients followed-up for > 5 years, the clinical and radiologic outcomes were compared between the two groups.

RESULTS

The joint line obliquity was significantly greater in the type 2 group than in the type 1 group (2.9 ± 1.3 vs. 0.9 ± 1.4, P < 0.001), and a significant risk factor for diffuse intrasubstance degeneration (P < 0.001; odds ratio, 2.88; 95% confidence interval, 1.27-6.54). The relative changes in the JSW in the type 2 group were greater than those in the type 1 group during the mean follow-up period of 7.9 ± 2.5 years (26% vs 10%, P = 0.045). The modified Lysholm score was not significantly different between the two groups (n.s).

CONCLUSION

The diffuse intrasubstance degeneration of medial meniscus HCTs in young patients is associated with increased joint line obliquity of the knee joints. The radiologic outcomes after APM were inferior in the patients with diffuse intrasubstance degeneration. However, the clinical outcomes were not different during the mid-term follow-up.

LEVEL OF EVIDENCE

Level III.

The repair of horizontal cleavage tears yields higher complication rates compared to meniscectomy: a systematic review

PURPOSE

Horizontal cleavage tears of the meniscus (HCTs) are primarily degenerative in nature, and, however, can be the result of trauma. Such tears account for 12-35% of all tear patterns and can be treated by partial meniscectomy or arthroscopic repair. The purpose of this review was to systematically assess the outcomes and complications for patients undergoing the surgical treatment of HCTs.

METHODS

This review has been conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analyses. The electronic databases PubMed, MEDLINE, and EMBASE were searched from data inception to December 30, 2018 for articles addressing the surgical treatment of HCTs. The Methodological Index for Non-randomized Studies was used to assess study quality. Data are presented descriptively.

RESULTS

Overall, 23 studies were identified, comprising of 702 patients (708 knees) with a mean age of 36.6 ± 9.9 years and a mean follow-up of 33.6 ± 19.6 months. The majority of patients were treated with a partial meniscectomy (59.0%), followed by repair (32.8%) and total meniscectomy (8.2%). Both meniscectomy and repair patients had improvements which surpassed minimal clinically important differences with regard to clinical (e.g. pain, function, daily living) and radiographic outcomes. The overall complication rate was 5.1%, primarily involving patients undergoing meniscal repair (12.9% of all knees undergoing a repair).

CONCLUSION

Although meniscal repair theoretically may provide improvement in biomechanical loading, patients undergoing repair had higher complication rates than those undergoing partial meniscectomy. Clinicians should consider the available implants in determining which tear patterns to repair and future studies with long-term follow-up are needed to investigate complications (e.g. secondary meniscal procedures) as well as the potential for delay in the development of osteoarthritis.

LEVEL OF EVIDENCE

Level IV.

Loose body as an obstacle for posterolateral arthroscopic portal formation in the knee joint

In this report, we present a case with difficult arthroscopic posterolateral portal formation due to loose body located in posterior compartment. These loose bodies are responsible for pain, decreased range of motion and cartilage damage in the knee joint. By making the posterior trans-septal portal prior, posterolateral portal could be made without difficulty completing the planned arthroscopic procedure.

Arthroscopic approach to the posterior compartment of the knee using a posterior transseptal portal

Arthroscopic surgery of the posterior compartment of the knee is difficult when only two anterior portals are used for access because of the inaccessibility of the back of the knee. Since its introduction, the posterior transseptal portal has been widely employed to access lesions in the posterior compartment. However, special care should be taken to avoid neurovascular injuries around the posteromedial, posterolateral, and transseptal portals. Most importantly, popliteal vessel injury should be avoided when creating and using the transseptal portal during surgery. Purpose of the present study is to describe how to avoid the neurovascular injuries during establishing the posterior three portals and to introduce our safer technique to create the transseptal portal. To date, we have performed arthroscopic surgeries via the transseptal portal in the posterior compartments of 161 knees and have not encountered nerve or vascular injury. In our procedure, the posterior septum is perforated with a 1.5-3.0-mm Kirschner wire that is protected by a sheath inserted from the posterolateral portal and monitored from the posteromedial portal to avoid popliteal vessel injury.

Analysis of displacement and deformation of the medial meniscus with a horizontal tear using a three-dimensional computer model

PURPOSE

The displacement and deformation of the knee meniscus significantly affect its roles; however, little is known about the displacement and deformation patterns of a torn medial meniscus. The objective of this study was to evaluate quantitatively the patterns of displacement and deformation in horizontally torn medial menisci during knee flexion.

METHODS

Twenty patients with horizontally torn medial menisci underwent three-dimensional (3-D) magnetic resonance imaging at varying degrees of knee flexion, and 3-D computer models of the tibia, tibial articular cartilage, and meniscus were generated. Based on these, the size of the horizontal tear (% tear) was evaluated and defined as the circumferential ratio between the length of the horizontal tear and that of the entire meniscus. The 3-D meniscus models were automatically superimposed over images taken at 0, 20, 40, and 60° of knee flexion by the voxel-based registration method. Meniscal motion and deformation during knee flexion were visualized and quantitatively calculated on the mid-sagittal plane. Correlations between the size of horizontal tear, displacement/deformation of torn menisci, and clinical symptoms were evaluated after conservative treatment for 3 months.

RESULTS

The % tear was 35.7 ± 12.5 % (range 13.7-55.5 %). During knee flexion, all torn menisci moved posteriorly, with gradual widening of horizontal and vertical gaps (p < 0.05). A direct correlation was observed between % tear and change in the vertical tear gap during knee flexion (p < 0.05). There was an inverse correlation between Lysholm score and % tear (p < 0.05).

CONCLUSION

Medial meniscal horizontal tears widen and deform during knee flexion, and % tear correlates with the change in the vertical gap. Patients with a lower % tear are more capable of performing activities of daily living after conservative treatment. This method may help clarify the cause of pain in patients with medial meniscus tears as well as facilitate the selection of an appropriate treatment plan.

LEVEL OF EVIDENCE

Case series, Level IV.

Arthroscopic repair of horizontal meniscal cleavage tears with marrow-stimulating technique

PURPOSE

The purpose of this study was to evaluate patients after arthroscopic repair of meniscal horizontal tears with a marrow-stimulating technique through clinical signs and second-look arthroscopy.

METHODS

We retrospectively reviewed a consecutive series of 32 meniscal repairs with horizontal cleavage tears and evaluated them through clinical assessment and second-look arthroscopic examinations. Arthroscopic meniscal repair and a marrow-stimulating technique were performed. Functional outcomes were evaluated using the visual analog scale (VAS) pain score, Lysholm knee scoring scale, and Tegner activity scale. Assessment of meniscal healing was evaluated clinically by the presence of meniscal signs; second-look arthroscopy was performed in 11 patients. Correlation between chronicity of a meniscal lesion (time from initial symptom [TFIS]) and meniscal healing was evaluated.

RESULTS

The mean follow-up period was 45.6 ± 13.9 months. Improvements in mean VAS scores from 6.7 to 1.9 (P < .001) were observed. The Lysholm score increased from 48.0 ± 14.4 to 92.0 ± 6.3 (P < .001). The Tegner activity score increased from 3.3 ± 1.1 to 6.8 ± 0.8 (P < .001). At the last follow-up, 29 of 32 patients (91%) were evaluated as healing in the clinical assessment. Of the 11 patients who underwent second-look arthroscopy, 8 (73%) showed complete healing, 2 (18%) had incomplete healing, and 1 (9%) failed to heal. Correlation between TFIS and meniscal healing was clinically significant (P = .001) but arthroscopically insignificant (P = .085) on second-look arthroscopy.

CONCLUSIONS

The meniscal repair procedure for horizontal cleavage tears in the present study suggests an alternative treatment option to approach the treatment of meniscal tears extending into the avascular zone and degenerative tissue. The marrow-stimulating technique using a cannulated reamer can be considered as an alternative method for the augmentation of meniscal healing.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.