start-ver=1.4 cd-journal=joma no-vol=28 cd-vols= no-issue=11 article-no= start-page=3405 end-page=3415 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190626 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Medial meniscus posterior root tear causes swelling of the medial meniscus and expansion of the extruded meniscus: a comparative analysis between 2D and 3D MRI en-subtitle= kn-subtitle= en-abstract= kn-abstract=Purpose
This study aimed to clarify the advantages of three-dimensional (3D) magnetic resonance imaging (MRI) over two-dimensional (2D) MRI in measuring the size of the medial meniscus (MM) and to analyse the volumes of MM and the extruded meniscus in patients with MM posterior root tear (MMPRT), at 10° and 90° knee flexion.
Methods
This study included 17 patients with MMPRTs and 15 volunteers with uninjured knees. The MMs were manually segmented for 3D reconstruction; thereafter, the extruded part separated from the tibial edge was determined. The length, width, height, and extrusion of MM were measured by the 2D and 3D methods, and compared. The MM volume, extruded meniscus volume, and their ratio were also calculated using 3D analysis software in the two groups.
Results
The estimated length and posterior height of MM were larger with 3D MRI than with 2D MRI measurements. The MM volume was significantly greater in MMPRT knees than in normal knees, with increasing MM height. In MMPRT knees, the mean volume of the extruded meniscus and its ratio significantly increased by 304 mm3 (p = 0.02) and 9.1% (p < 0.01), respectively, during knee flexion.
Conclusions
This study demonstrated that 3D MRI could estimate the precise MM size and that MMPRT caused swelling of the meniscus due to the increased thickness in the posteromedial part. The clinical significance of this study lies in its 3D evaluation of MM volume, which should help the surgeon understand the biomechanical failure of MM function and improve MMPRT repair technique. en-copyright= kn-copyright= en-aut-name=OkazakiYoshiki en-aut-sei=Okazaki en-aut-mei=Yoshiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=FurumatsuTakayuki en-aut-sei=Furumatsu en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=YamaguchiTakuya en-aut-sei=Yamaguchi en-aut-mei=Takuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KodamaYuya en-aut-sei=Kodama en-aut-mei=Yuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KamatsukiYusuke en-aut-sei=Kamatsuki en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=MasudaShin en-aut-sei=Masuda en-aut-mei=Shin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=OkazakiYuki en-aut-sei=Okazaki en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=HiranakaTakaaki en-aut-sei=Hiranaka en-aut-mei=Takaaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=ZhangXiming en-aut-sei=Zhang en-aut-mei=Ximing kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=OzakiToshifumi en-aut-sei=Ozaki en-aut-mei=Toshifumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= affil-num=1 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= affil-num=2 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= affil-num=3 en-affil=Division of Radiology, Medical Technology Department, Okayama University Hospital kn-affil= affil-num=4 en-affil=Department of Orthopaedic Surgery, Iwakuni Medical Center kn-affil= affil-num=5 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= affil-num=6 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= affil-num=7 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= affil-num=8 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= affil-num=9 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= affil-num=10 en-affil=Department of Orthopaedic Surgery, Okayama University Graduate School kn-affil= en-keyword=Medial meniscus kn-keyword=Medial meniscus en-keyword=Posterior root tear kn-keyword=Posterior root tear en-keyword=Osteoarthritis kn-keyword=Osteoarthritis en-keyword=Meniscal volume kn-keyword=Meniscal volume en-keyword=Medial extrusion kn-keyword=Medial extrusion en-keyword=Three-dimensional magnetic resonance imaging kn-keyword=Three-dimensional magnetic resonance imaging en-keyword=Flexed-knee position kn-keyword=Flexed-knee position END start-ver=1.4 cd-journal=joma no-vol=28 cd-vols= no-issue=11 article-no= start-page=3416 end-page=3425 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20191128 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Transtibial fixation for medial meniscus posterior root tear reduces posterior extrusion and physiological translation of the medial meniscus in middle-aged and elderly patients en-subtitle= kn-subtitle= en-abstract= kn-abstract=Purpose
To investigate changes in meniscal extrusion during knee flexion before and after pullout fixation for medial meniscus posterior root tear (MMPRT) and determine whether these changes correlate with articular cartilage degeneration and short-term clinical outcomes.
Methods
Twenty-two patients (mean age 58.4 ± 8.2 years) diagnosed with type II MMPRT underwent open magnetic resonance imaging preoperatively, 3 months after transtibial fixation and at 12 months after surgery, when second-look arthroscopy was also performed. The medial meniscus medial extrusion (MMME) and the medial meniscus posterior extrusion (MMPE) were measured at knee 10° and 90° flexion at which medial meniscus (MM) posterior translation was also calculated. Articular cartilage degeneration was assessed using International Cartilage Research Society grade at primary surgery and second-look arthroscopy. Clinical evaluations included Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee subjective knee evaluation form, Lysholm score, Tegner activity level scale, and pain visual analogue scale.
Results
MMPE at 10° knee flexion was higher 12 months postoperatively than preoperatively (4.8 ± 1.5 vs. 3.5 ± 1.2, p = 0.01). MMPE at 90° knee flexion and MM posterior translation were smaller 12 months postoperatively than preoperatively (3.5 ± 1.1 vs. 4.6 ± 1.3, 7.2 ± 1.7 vs. 8.9 ± 2.0, p < 0.01). Articular cartilage degeneration of medial femoral condyle correlated with MMME in knee extension (r = 0.5, p = 0.04). All clinical scores significantly improved 12 months postoperatively. However, correlations of all clinical scores against decreased MMPE and increased MMME were not detected.
Conclusions
MMPRT transtibial fixation suppressed the progression of MMPE and cartilage degeneration and progressed MMME minimally in knee flexion position at 1 year. However, in the knee extension position, MMME progressed and correlated with cartilage degeneration of medial femoral condyle. MMPRT transtibial fixation contributes to the dynamic stability of the MM in the knee flexion position. en-copyright= kn-copyright= en-aut-name=KodamaYuya en-aut-sei=Kodama en-aut-mei=Yuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=FurumatsuTakayuki en-aut-sei=Furumatsu en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MasudaShin en-aut-sei=Masuda en-aut-mei=Shin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=OkazakiYoshiki en-aut-sei=Okazaki en-aut-mei=Yoshiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KamatsukiYusuke en-aut-sei=Kamatsuki en-aut-mei=Yusuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=OkazakiYuki en-aut-sei=Okazaki en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=HiranakaTakaaki en-aut-sei=Hiranaka en-aut-mei=Takaaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=MiyazawaShinichi en-aut-sei=Miyazawa en-aut-mei=Shinichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=YasumitsuMasaharu en-aut-sei=Yasumitsu en-aut-mei=Masaharu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=OzakiToshifumi en-aut-sei=Ozaki en-aut-mei=Toshifumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= affil-num=1 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=2 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=3 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=4 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=5 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=6 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=7 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=8 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= affil-num=9 en-affil=Department of Orthopaedic Surgery, Iwakuni Clinical Center kn-affil= affil-num=10 en-affil=Department of Orthopaedic Surgery, Okayama University Hospital kn-affil= en-keyword=Medial meniscus kn-keyword=Medial meniscus en-keyword=Posterior root tear kn-keyword=Posterior root tear en-keyword=Transtibial fixation kn-keyword=Transtibial fixation en-keyword=Meniscus extrusion kn-keyword=Meniscus extrusion en-keyword=Open magnetic resonance imaging kn-keyword=Open magnetic resonance imaging END