Summary

There is poor co-relation between patient reported outcome measures and meniscus healing as assessed by indirect MR arthrography for meniscus repairs larger than 25 mm.

Abstract

Introduction

The precarious vascular supply however precludes a consistent predictable outcome especially in tears greater than 2.5 cm. in length. A second-look arthroscopy is the gold standard in assessing meniscal healing, though it is an invasive procedure. The objective of the study was to non-invasively evaluate the meniscus repaired using any of the described meniscus repair techniques, in tears greater than 2.5 cm., using direct as well as indirect (intravenous) magnetic resonance (MR) arthrography techniques. We also correlate the MR imaging findings with clinical scores to assess whether actual healing is related to the symptoms.

Materials And Methods

Forty patients (22 males, 18 females) with mean age 33.4 (13-68) years who underwent arthroscopic meniscal repair for 45 meniscal tears larger than 2.5cm were prospectively recruited after IRB approval and informed consent. Post-operative IKDC scores, KOOS and Tegner Lysholm activity scores were recorded at time of latest clinical follow-up. They underwent MR Imaging and indirect MR Arthrography to assess meniscal healing. Crues’ criteria were used to determine the meniscal integrity and the MRI findings were correlated clinically with the outcome scores. Multiple regression analysis was performed for correlation between MR imaging results and clinical scores.

Results

MRI study was carried out at a mean of 21 months post-surgical repair. 5 patients underwent both medial and lateral meniscal repairs. On indirect MRA, 33 of the 45 meniscal repairs, (74%) showed meniscal healing, 10 (22%) showed incomplete healing with some granulation tissue and 2 (4%) showed retear at the site of repair. Of the 20 symptomatic patients, 7(35%) demonstrated incompletely healed/unhealed repair and 10 (50%) showed healed meniscal repair. Of the 20 asymptomatic patients (50%), 4(20%) showed incomplete healing of meniscal repair on MRI. 33 (82.5%) of the 40 patients underwent concurrent ACL reconstruction at the time of meniscal repair. 30 of the 39 repaired menisci showed full healing with scar on Indirect MRA. If done within 12 months of surgery (3/39 repairs), MRA does not aid in determining healing. In 16 patients beyond 18 months post repair, Indirect MRA confirmed the findings seen on conventional sequences. Of the 17 patients between 12-18 month post repair incomplete partial healing was confirmed in 4. 3 menisci were confirmed as unhealed or had a retear at the repair site and were symptomatic. 9 of the symptomatic patients had other pathologies. The mean IKDC, KOOS and Tegner-Lysholm scores in all patients were 76.3 (range 40.2-98.9); 86.7 (range 54.2-98.8) and 89.9 (range 71-100) respectively. Neither status of meniscal healing nor extent of healed length showed any statistical correlation with clinical scores.

Conclusion

This study establishes the role of Indirect MR arthrography for evaluation of meniscal repair, avoiding the invasive second look arthroscopy, specially between 12 -18 months after surgery. This study showed poor correlation between MR imaging results and clinical scores. Indirect MRA showed meniscus healing in 74% of repairs and in 50% of the symptomatic patients, avoiding a second look arthroscopy.