Ged G Wieschhoff1, Jacob C Mandell2, Gregory J Czuczman2, Violeta Nikac2, Nehal Shah2, Stacy E Smith2. 1. Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA. gwieschhoff@bwh.harvard.edu. 2. Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
Abstract
OBJECTIVE: Hamstring muscle deficiency is increasingly recognized as a risk factor for anterior cruciate ligament (ACL) tears. The purpose of this study is to evaluate the vastus medialis to semimembranosus cross-sectional area (VM:SM CSA) ratio on magnetic resonance imaging (MRI) in patients with ACL tears compared to controls. MATERIALS AND METHODS: One hundred knee MRIs of acute ACL tear patients and 100 age-, sex-, and side-matched controls were included. Mechanism of injury, contact versus non-contact, was determined for each ACL tear subject. The VM:SM CSA was measured on individual axial slices with a novel method using image-processing software. One reader measured all 200 knees and the second reader measured 50 knees at random to assess inter-reader variability. The intraclass correlation coefficient (ICC) was calculated to evaluate for correlation between readers. T-tests were performed to evaluate for differences in VM:SM CSA ratios between the ACL tear group and control group. RESULTS: The ICC for agreement between the two readers was 0.991 (95% confidence interval 0.984-0.995). Acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.44 vs. 1.28; p = 0.005). Non-contact acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.48 vs. 1.20; p = 0.003), whereas contact acute ACL tear patients do not (1.23 vs. 1.26; p = 0.762). CONCLUSION: Acute non-contact ACL tears are associated with increased VM:SM CSA ratios, which may imply a relative deficiency in hamstring strength. This study also demonstrates a novel method of measuring the relative CSA of muscles on MRI.
OBJECTIVE: Hamstring muscle deficiency is increasingly recognized as a risk factor for anterior cruciate ligament (ACL) tears. The purpose of this study is to evaluate the vastus medialis to semimembranosus cross-sectional area (VM:SM CSA) ratio on magnetic resonance imaging (MRI) in patients with ACL tears compared to controls. MATERIALS AND METHODS: One hundred knee MRIs of acute ACL tear patients and 100 age-, sex-, and side-matched controls were included. Mechanism of injury, contact versus non-contact, was determined for each ACL tear subject. The VM:SM CSA was measured on individual axial slices with a novel method using image-processing software. One reader measured all 200 knees and the second reader measured 50 knees at random to assess inter-reader variability. The intraclass correlation coefficient (ICC) was calculated to evaluate for correlation between readers. T-tests were performed to evaluate for differences in VM:SM CSA ratios between the ACL tear group and control group. RESULTS: The ICC for agreement between the two readers was 0.991 (95% confidence interval 0.984-0.995). Acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.44 vs. 1.28; p = 0.005). Non-contact acute ACL tear patients have an increased VM:SM CSA ratio compared to controls (1.48 vs. 1.20; p = 0.003), whereas contact acute ACL tear patients do not (1.23 vs. 1.26; p = 0.762). CONCLUSION: Acute non-contact ACL tears are associated with increased VM:SM CSA ratios, which may imply a relative deficiency in hamstring strength. This study also demonstrates a novel method of measuring the relative CSA of muscles on MRI.
Authors: Letha Y Griffin; Marjorie J Albohm; Elizabeth A Arendt; Roald Bahr; Bruce D Beynnon; Marlene Demaio; Randall W Dick; Lars Engebretsen; William E Garrett; Jo A Hannafin; Tim E Hewett; Laura J Huston; Mary Lloyd Ireland; Robert J Johnson; Scott Lephart; Bert R Mandelbaum; Barton J Mann; Paul H Marks; Stephen W Marshall; Grethe Myklebust; Frank R Noyes; Christopher Powers; Clarence Shields; Sandra J Shultz; Holly Silvers; James Slauterbeck; Dean C Taylor; Carol C Teitz; Edward M Wojtys; Bing Yu Journal: Am J Sports Med Date: 2006-09 Impact factor: 6.202
Authors: Nathan A Mall; Peter N Chalmers; Mario Moric; Miho J Tanaka; Brian J Cole; Bernard R Bach; George A Paletta Journal: Am J Sports Med Date: 2014-08-01 Impact factor: 6.202