OBJECTIVE: The “cartilage black line sign” is a recently described T2 dark cartilage lesion that we have identified appearing as a cleft in the trochlear trough. The purpose of our study was to define the MR imaging characteristics of a trochlear cleft, determine its incidence, and correlate the MR findings with arthroscopy. MATERIALS AND METHODS: A total of 1,300 consecutive MR examinations of the knee were retrospectively reviewed by consensus of two fellowship-trained musculoskeletal radiologists. The MR imaging characteristics and location of a trochlear cleft were determined. Imaging results were compared to arthroscopy when available. Patient age and gender were compared to 25 randomly selected control patients without trochlear clefts. RESULTS: A total of 25 (1.9%) individuals (11 females and 14 males; age range 19–45 years; mean age 28 years) were diagnosed with a trochlear cleft. The control group consisted of 11 females and 14 males; age range 19–83 years; mean age 46 years. Mean cleft length was 7 mm (range 6–12 mm); cleft location was consistently in the lower trochlear trough. No full-thickness cartilage defects were identified in the eight individuals in whom arthroscopic correlation was available. A grade 2 cartilage lesion was identified in a single individual; another progressed from grade 0 to a full-thickness trochlear lesion over an 8-month interval. Eight individuals were athletes. No significant difference in gender was noted between the two groups, however, the study group was significantly younger p<0.0001. CONCLUSIONS: A trochlear cleft is a rare finding in young active individuals. It most likely indicates an incomplete cartilage fissure which may rarely progress to a full-thickness defect.
OBJECTIVE: The “cartilage black line sign” is a recently described T2 dark cartilage lesion that we have identified appearing as a cleft in the trochlear trough. The purpose of our study was to define the MR imaging characteristics of a trochlear cleft, determine its incidence, and correlate the MR findings with arthroscopy. MATERIALS AND METHODS: A total of 1,300 consecutive MR examinations of the knee were retrospectively reviewed by consensus of two fellowship-trained musculoskeletal radiologists. The MR imaging characteristics and location of a trochlear cleft were determined. Imaging results were compared to arthroscopy when available. Patient age and gender were compared to 25 randomly selected control patients without trochlear clefts. RESULTS: A total of 25 (1.9%) individuals (11 females and 14 males; age range 19–45 years; mean age 28 years) were diagnosed with a trochlear cleft. The control group consisted of 11 females and 14 males; age range 19–83 years; mean age 46 years. Mean cleft length was 7 mm (range 6–12 mm); cleft location was consistently in the lower trochlear trough. No full-thickness cartilage defects were identified in the eight individuals in whom arthroscopic correlation was available. A grade 2 cartilage lesion was identified in a single individual; another progressed from grade 0 to a full-thickness trochlear lesion over an 8-month interval. Eight individuals were athletes. No significant difference in gender was noted between the two groups, however, the study group was significantly younger p<0.0001. CONCLUSIONS: A trochlear cleft is a rare finding in young active individuals. It most likely indicates an incomplete cartilage fissure which may rarely progress to a full-thickness defect.
Authors: Richard Kijowski; Donna G Blankenbaker; Michael Woods; Alejandro Munoz Del Rio; Arthur A De Smet; Scott B Reeder Journal: AJR Am J Roentgenol Date: 2011-01 Impact factor: 3.959
Authors: M A Bredella; P F Tirman; C G Peterfy; M Zarlingo; J F Feller; F W Bost; J P Belzer; T K Wischer; H K Genant Journal: AJR Am J Roentgenol Date: 1999-04 Impact factor: 3.959
Authors: Benedikt J Schwaiger; Alexandra S Gersing; John Mbapte Wamba; Michael C Nevitt; Charles E McCulloch; Thomas M Link Journal: Radiology Date: 2016-05-02 Impact factor: 11.105