Medial Knee Osteoarthritis Precedes Medial Meniscal Posterior Root Tear with an Event of Painful Popping

Transcription

1 Medial Knee Osteoarthritis Precedes Medial Meniscal Posterior Root Tear with an Event of Painful Popping Dhong Won Lee, M.D, Ji Nam Kim, M.D., Jin Goo Kim, M.D., Ph.D. KonKuk University Medical Center

2 Dhong Won Lee, M.D, Ji Nam Kim, M.D., Jin Goo Kim, M.D., Ph.D. We have no financial conflicts to disclose.

3 Introduction Asian s lifestyle of squatting and sitting on the floor Impingement of the medial meniscal posterior horn Degenerative medial meniscal posterior root Prone to tear by minor trauma Degeneration change: Before Popping SI Bin et al. Arthroscopy 2004 Root elongation with MME > 3mm early OA (+)

4 Introduction Single event of painful popping during light activities Not only allows the physician to predict the presence of an MMPRT* but also predicts the degenerative status of the articular cartilage. * MMPRT: medial meniscal posterior root tear

5 Purpose & Hypothesis To assess magnetic resonance imaging (MRI) and radiologic findings of Medial Meniscal Posterior Root Tears (MMPRTs) with an event of painful popping within 3 weeks We hypothesized that most of MMPRTs with a single painful popping event would show pre-existed pathologic MME and articular cartilage degeneration, and larger contact area of medial femoral condyle to medial tibial plateau could affect the MME. In addition, MME would be correlated with knee osteoarthritis.

6 Patients and Methods Diagnostic cross-sectional study, Level IV. A total of 38 patients Inclusion criteria: 1) younger than 65 years old; 2) had a single event of painful popping; and 3) underwent MRI examinations within 3 weeks A painful popping was defined as a single episode of an explosive, sudden loud, painful sensation, and not a habitual clicking, and this event was occurred during walking, standing up or squatting, and going up or down stairs.

7 Patients and Methods Radiological assessments (x-ray) 1. Kellgren-Lawrence grade (Rosenberg view) Gr 1 - questionable osteophytes & no joint space narrowing Gr 2 - definitive osteophytes with possible joint space narrowing Gr 3 - definitive joint space narrowing with moderate multiple osteophytes Gr 4 - severe joint space narrowing with cysts, and sclerosis 2. Mechanical axis MRI Medial Meniscus extrusion (MME, mm) - Absolute MME and RPE (relative percentage of extrusion) Medial compartment cartilage loss evaluation : the modified Outerbridge scale (MOS) grade 1, cartilage surface fibrillation grade 2, <50% loss of cartilage thickness grade 3, >50% loss of cartilage thickness grade 4, exposed subchondral bone

8 Patients and Methods Articulation width of medial femoral condyle (MFC) at 0, 30, 60, and 90, medial tibial condyle (MTC) width, and MFC/MTC at 0, 30, 60, and 90 were measured. Larger medial femoral condyle (MFC) to medial tibial condyle (MTC) could affect the degree of MME

9 Results Patient Demographic and Overall Results N =38 Age (yrs) 58.5 ± 10.5 Sex (male/female) 0/26 BMI (kg/m 2 ) 25.5 ± 2.7 Time from popping event to MRI examination (days) 15.4 ± 4.1 MME (mm) 2.9 ± 1.2 RPE (%) 22.0 ± 10.3 modified Outerbridge scale, 1 / 2 / 3 / 4 (n) 5 / 25 / 6 / 2 Kellgren-Lawrence grade, 1 / 2 / 3 / 4 (n) 6 / 30 / 2 / 0 Alignment Inv. (degree) 3.4 ± 2.6 Alignment Un-inv. (degree) 3.0 ± 2.2

10 Results Comparison of Overall Results between MME 3 mm MME < 3mm P value MME 3 mm and MME < 3 mm (Group G, n = 20) (Group L, n= 18) BMI (kg/m 2 ) 26.1 ± ± MME (mm) 3.8 ± ± 0.6 < RPE (%) 29.1 ± ± 4.1 < The ratio between MME and MFC/MTC at ± ± 0.7 < modified Outerbridge scale, 1 / 2 / 3 / 4 (n) 1 / 12 / 5 / 2 4 / 13 / 1 / Kellgren-Lawrence grade, 1 / 2 / 3 / 4 (n) 1/ 16 / 3 / 0 5 / 13 / 0 / Alignment Inv. (degree) 3.6 ± ± Alignment Un-inv. (degree) 3.2 ± ± MFC/MTC at ± ± MFC/MTC at ± ± MFC/MTC at ± ± MFC/MTC at ± ±

11 Results MME 3 mm MME < 3 mm P value Comparison of OA degree between (Group G, n = 20) (Group L, n= 18) MME 3 mm and MME < 3 mm Modified Outerbridge scale < Gr 3, n (%) Gr 3, n (%) 13 (65 %) 7 (35 %) 17 (94.4 %) 1 (5.6 %) % MOS Gr 3 K-L Gr Gr 3 Kellgren-Lawrence grade < Gr 3, n (%) Gr 3, n (%) 17 (85 %) 3 (15 %) 18 (100 %) % MME 3 mm 5.6% 0 MME < 3 mm Correlation between Medial Meniscal Extrusion (MME) Parameters and modified Outerbridge Scale, and Kellgren-Lawrence Grade modified Outerbridge scale Kellgren-Lawrence grade MME 0.522** 0.579** RPE 0.485* 0.504** Ratio between MME and MFC/MTC at ** 0.576** * < 0.05, ** < MME, Medial meniscal extrusion; RPE, Relative percentage of extrusion; MFC, Medial femoral condyle; MTC, Medial tibial condyle.

12 Conclusion Potential strength of the present study include the identification of medial compartment degenerative condition at the time of a painful popping in MMPRTs and evaluation of correlation between MME parameters and MOS, K-L grade, and regional knee geometry. More than 80% of MMPRT patients with an event of painful popping within 3 weeks showed that medial compartment degeneration preceded the event of popping. Therefore, identification of MME and articular cartilage degeneration at the time of painful popping in MMPRTs could be helpful when the surgeon determines the most appropriate treatment.

13 References 1. Kim JG, Lee YS, Bae TS, et al. Tibiofemoral contact mechanics following posterior root of medial meniscus tear, repair, meniscectomy, and allograft transplantation. Knee Surg Sports Traumatol Arthrosc 2013; 21: Andrews SH, Rattner JB, Jamniczky HA, et al. The structural and compositional transition of the meniscal roots into the fibrocartilage of the menisci. J Anat 2015; 226: Lee DW, Ha JK and Kim JG. Medial meniscus posterior root tear: A comprehensive review. Knee Surg Relat Res 2014; 26: Bin SI, Kim JM and Shin SJ. Radial tears of the posterior horn of the medial meniscus. Arthroscopy 2004; 20: Bhatia S, LaPrade CM, Ellman MB, et al. Meniscal root tears: Significance, diagnosis, and treatment. Am J Sports Med 2014; 42: Bae JH, Paik NH, Park GW, et al. Predictive value of painful popping for a posterior root tear of the medial meniscus in middle-aged to older asian patients. Arthroscopy 2013; 29: Lerer DB, Umans HR, Hu MX, et al. The role of meniscal root pathology and radial meniscal tear in medial meniscal extrusion. Skeletal Radiol 2004; 33: Guermazi A, Hayashi D, Jarraya M, et al. Medial posterior meniscal root tears are associated with development or worsening of medial tibiofemoral cartilage damage: The multicenter osteoarthritis study. Radiology 2013; 268: