title: Risk factors for ligamentum teres tears.
abstract: OBJECTIVE
  The purpose of this study was to examine the relationship between nontraumatic ligamentum teres (LT) tears and acetabular radiographic architecture.
  
  
  METHODS
  The inclusion criteria for this study were all patients who had anteroposterior pelvis radiographic views and had undergone arthroscopic examination of the LT. The exclusion criteria were Tonnis arthritic grade 3 and traumatic high-energy mechanisms of injury. Radiographic data were measured preoperatively on an anteroposterior pelvis view, including acetabular inclination (AI), lateral center edge (CE) angle, magnitude of cross-over sign, and ischial spine prominence. A Lateral Coverage Index (LCI) was defined as the center edge angle minus acetabular inclination. Hips were divided into 3 groups according to the LCI: (1) high: 34° and above; (2) medium: 19° to 33°; and (3) low: below 19°.
  
  
  RESULTS
  Of the 463 hips (430 patients) included in the study, 226 (49%) had a partial- or full-thickness LT tear. Patients with tears were significantly older than patients without tears (P < .0001), with average ages of 38 and 33 years, respectively. Radiographically, patients with tears had less acetabular retroversion, as reflected by lower ischial spine prominence values and lesser cross-over signs (P = .01 and .0005, respectively). Using the LCI, 115 hips (25%) were classified as high, 236 (50%) as medium, and 114 (25%) as low. Hips with low LCI were 1.74 times more likely to have LT tears than high LCI hips.
  
  
  CONCLUSIONS
  This study found that the presence of LT tears was associated with acetabular bony morphology and age. LT tears were less frequent with high LCI and acetabular retroversion and less frequent in patients younger than 30 years. Further study is needed to establish whether there is a causal relationship between acetabular undercoverage and LT tears and whether LT tears may be a sign of microinstability of the hip.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: American Hip Institute, Chicago, Illinois, USA. DrDomb@americanhipinstitute.org
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Domb
authors.forename: Dorea E
authors.initials: DE
authors.lastname: Martin
authors.forename: Itamar B
authors.initials: IB
authors.lastname: Botser
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000886:Anthropometry; D001182:Arthroscopy; D003646:Debridement; D004198:Disease Susceptibility; D005260:Female; D025981:Hip Injuries / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007512:Ischium / Q000000981:diagnostic imaging; D008023:Ligaments, Articular / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography; D016059:Range of Motion, Articular; D012307:Risk Factors; D012422:Rupture, Spontaneous / Q000453:epidemiology; D012720:Severity of Illness Index; D055815:Young Adult