Can discoid lateral meniscus be returned to the correct anatomic position and size of the native lateral meniscus after surgery?

Transcription

1 Can discoid lateral meniscus be returned to the correct anatomic position and size of the native lateral meniscus after surgery? Seong Hwan Kim,*M.D. 1, Joong Won Lee M.D. 2, and Sang Hak Lee, M.D. 2 From the 1 Departments of Orthopedic Surgery, Chung-Ang University Hospital, Korea, and 2 Center for Joint Diseases and Rheumatism, Kyung Hee University Hospital at Gangdong, Seoul, Korea

2 Disclosures Sang Hak Lee, MD No financial disclosure Or Conflict of interest

3 How much preserve? Arthroscopic meniscectomy for discoid lateral meniscus (DLM) in children. (Hayashi et al., 1988, J Bone Joint Surg Am.) Peripheral rim preserved 6~8mm in width Arthroscopic treatment of the discoid lateral meniscus (DLM) : results of long-term follow-up. (RD Vandermeer et al., 1989, Arthroscopy.) Peripheral rim preserved 4~5mm in width

4 Hypothesis and Purpose To evaluate the postoperative size and position of the remaining DLM after surgery compared with normal LM using MRI. Remaining DLM after partial meniscectomy with or without repair would be comparable in size and position in the knee joint to the normal LM The risk factors that affect postoperative meniscal extrusion and lead to smaller remaining meniscus of less than 6 mm were also evaluated.

5 Patients Demographics Discoid group Normal group P-value Number of Cases Male/Female 24/28 32/ Mean age (years) 23.9 ± ± Number of cases according to Age < Time interval from symptom to surgery 21.9 ± Presence of preoperative meniscal shift Type of meniscal shift Type of S urgery Normal 0 50 (Ⅰ) Anterocentral 10 0 (Ⅱ) Posterocentral shift type 8 0 (Ⅲ) Central 5 0 (Ⅳ) No shift 29 0 No surgery 0 50 Partial menisectomy 13 0 Partial menisectomy + repair

6 Surgical Method Partial meniscectomy With or without meniscus repair MM MFC LFC LM LFC Measurement with probe or ruler LM

7 MRI Evaluation Preoperative vs postoperative vs control DLM (remained) and MM vs normal LM Height / Width / Extrusion of meniscus

8 MRI Evaluation Sagittal plane (Kim SH et al., 2018, KSSTA) (Lee DH et al., 2015, Arthroscopy) Width and height

9 MRI Results Discoid group Normal group Preoperative Postoperative P-value P-value Coronal Images LM width 25.8± ± ± LM height 4.5± ± ± Absolute LM Extrusion -2.6± ± ± RPE(%) -16.9± ± ± Sagittal images a 8.2± ± ± b ± ± c 30.8± ± ± d - 9.6± ± e 4.9± ± ± Sagittal length of meniscus 30.8± ± ± (b+c+d) Entire sagittal 43.9± ± ± length(a+b+c+d+e) Sagittal ratio 71.6± ± ± AH height 5.9± ± ± PH height 7.6± ± ± The MRI evaluations of coronal extrusion and size of lateral meniscus

10 Coronal images Group 6mm Number of cases >6mm P-value Absolute LM Extrusion 0.5± ± Sagittal images LM width 4.6± ± LM height 4.9± ± RPE(%) 15.1± ± a 5.6± ± b 9.1± ± c 16.6± ± d 7.5± ± e 3.6± ± Sagittal length of meniscus (b+c+d) 32.8± ± Entire sagittal length(a+b+c+d+e) 43.4± ± Sagittal ratio 78.9± ± AH height 5.5± ± PH height 7.0± ± Comparison of MRI evaluations according to the width less than 6mm of coronal plane MRI Results

11 MRI Results Factor Odds Ratio Β-Value±S.E Risk of extrusion of remained LM 95% Confidence i nterval P value LM height ± Presence of preoperat ive meniscal shift ± Gender ± No surgery reference Partial meniscectomy ± Partial meniscectomy + repair ± Constant term ± On logistic regression analysis the association for the extrusion of remained LM

12 Conclusion The width of the remained meniscus in discoid group was comparable with that of normal subjects. However, the subluxation of remained meniscus in discoid group was found to anteriorly and laterally Preoperative meniscal shift and combined meniscus repair were the major factors for smaller width and greater meniscus extrusion

13 References 1. Ahn JH, Kim KI, Wang JH, Jeon JW, Cho YC, Lee SH. Long-term results of arthroscopic reshaping for symptomatic discoid lateral meniscus in children. Arthroscopy. 2015;31(5): doi: /j.arthro Epub 2015 Feb Ahn JH, Lee SH, Kim KI, Nam J. Arthroscopic meniscus repair for recurrent subluxation of the lateral meniscus. Knee Surg Sports Traumatol Arthrosc. 2018;26(3): doi: /s Epub Mar Ahn JH, Lee SH, Yoo JC, Lee HJ, Lee JS. Bilateral discoid lateral meniscus in knees: evaluation of the contralateral knee in patients with symptomatic discoid lateral meniscus. Arthroscopy. 2010;26(10): Ahn JH, Lee SH, Yoo JC, Lee YS, Ha HC. Arthroscopic partial meniscectomy with repair of the peripheral tear for symptomatic discoid lateral meniscus in children: results of minimum 2 years of follow-up. Arthroscopy. 2008;24(8): Ahn JH, Lee YS, Ha HC, Shim JS, Lim KS. A novel magnetic resonance imaging classification of discoid lateral meniscus based on peripheral attachment. Am J Sports Med. 2009;37(8): Hayashi LK, Yamaga H, Ida K, Miura T. Arthroscopic meniscectomy for discoid lateral meniscus in children. J Bone Joint Surg Am. 1988;70(10): Klingele KE, Kocher MS, Hresko MT, Gerbino P, Micheli LJ. Discoid lateral meniscus: prevalence of peripheral rim instability. J Pediatr Orthop. 2004;24(1): Lee DH, Kim JM, Jeon JH, Cha EJ, Bin SI. Effect of sagittal allograft position on coronal extrusion in lateral meniscus allograft transplantation. Arthroscopy. 2015;31(2): Kim SH, Ahn J, Kim TW, Kim KI, Lee SH. Midbody of the medial meniscus as a reference of preservation in partial meniscectomy for complete discoid lateral meniscus. Knee Surg Sports Traumatol Arthrosc. 2018;7(10): Vandermeer RD, Cunningham FK. Arthroscopic treatment of the discoid lateral meniscus: results of long-term follow-up. Arthroscopy. 1989;5(2): Verdonk P, Depaepe Y, Desmyter S, et al. Normal and transplanted lateral knee menisci: evaluation of extrusion using magnetic resonance imaging and ultrasound. Knee Surg Sports Traumatol Arthrosc. 2004;12(5): Yamasaki S, Hashimoto Y, Takigami J, Terai S, Takahashi S, Nakamura H. Risk Factors Associated With Knee Joint Degeneration After Arthroscopic Reshaping for Juvenile Discoid Lateral Meniscus. Am J Sports Med. 2017;45(3):