2017 ISAKOS Biennial Congress ePoster #1312

 

Prospective Short-Term MRI Controlled Investigation of the Healing Properties of Meniscus Repairs (Drks: 00009866)

Lukas Willinger, MD, Munich GERMANY
Andrea E. Achtnich, Assoc. Prof., Munich GERMANY
Felix Förschner, MD, Munich GERMANY
Klaus Wörtler, MD, Prof., Munich, Bavaria GERMANY
Andreas B. Imhoff, MD, Prof. Emeritus, Sauerlach / Munich, Bavaria GERMANY
Elmar Herbst, MD, PhD, Muenster GERMANY

Department of Orthopaedic Sports Medicine, Klinikum Rechts der Isar, Technical University Munich, Munich, GERMANY

FDA Status Not Applicable

Summary

Meniscus repair plays a key role regarding prevention of knee osteoarthritis. Therefore healing properties of the meniscus are still a matter of debate, thus the role of MRI to identify failures of repair remains unclear. The purpose of this study was to investigate signal alterations on MRI during the expected healing phase of 3 months postoperatively and compare them with the clinical state.

Abstract

Purpose/ Hypotheses:

The purpose of the study was to prospectively investigate signal alterations in short-term follow-up after acute meniscus repair on specific magnetic resonance imaging (MRI) scan sequences. It was hypothesized that 1) there are different meniscus healing properties depending on lesion configuration and size, and 2) the tear zone has an influence on the healing properties of the meniscus.

Material And Methods

We enrolled patients (age 18-45 years) with traumatic meniscus lesion, subsequent arthroscopic meniscus repair within 6 weeks and available preoperative MRI. Exclusion criteria were age < 18 or >45 years, arthrosis > ICRS III and multiligamentous knee injuries.
Radiological follow-up examinations were performed 2, 4, 6 and 12 weeks after operation using a 3T-MRI. Results evaluation was based on ISAKOS meniscus classification system. Meniscus healing were classified according to Henning’s criteria in A) healed, B) partially healed (> 50%) and C) not healed. Furthermore, clinical examination and outcome scores (IKDC, KOOS, Lysholm Score) were surveyed preoperatively and 12 weeks after surgery. Data were analyzed using SPSS statistics software version 21 (IBM, New York, USA). Statistical significance was set at a p value of < 0.05.

Results

At this time point, 20 patients (19m, 1w) with a total of 24 meniscus tears (13 medial, 11 lateral) met the inclusion criteria. The average tear length was 19.5mm (6 – 40mm). 15 tears were located in the rim zone 1 and 9 tears were more medially in zone 2. In 16 (80 %) patients an additional anterior cruciate ligament (ACL) reconstruction was performed. Clinical scores improved significantly 12 weeks after surgery: IKDC Score (preOP: 44.1, postOP: 66.3), KOOS (preOP: 45.6, postOP: 74.6) and Lysholm Score (preOP: 48.1, postOP: 77.3) (p < 0.05).
Regarding MRI examination at 6 weeks follow-up, 13 menisci (54%) were rated as deemed healed, 8 menisci (33%) as partially healed and 3 menisci as not healed (13%). At 12 weeks follow-up 15 menisci (62%) were considered healed, 6 menisci (25%) partially healed and 3 menisci (13%) showed intrameniscal joint fluid in more than 50% of meniscus thickness and were consequently rated as not healed. Two bucket handle tears of the medial meniscus and one radial tear of the lateral meniscus, all located in the red-red zone, were not healed after 12 weeks.

Conclusion

To our knowledge, this is the first study of short term MRI investigation after meniscal repair in acute meniscus tears. After 12 weeks all investigated menisci showed signal alteration on MRI, in most instances considered as scar tissue without intrameniscal joint fluid. According to Henning’s criteria 87% of the menisci were rated as healed or partially healed and clinical follow-up showed good short-term results after meniscus repair. Tear size and location was not correlated with non-healing results.