| Purpose:To determine the prevalence of qualitative radiographic findings associated with femoroacetabular impingement (FAI) in asymptomatic adults using standardized anteroposterior pelvic radiographs. Materials and methods:1. We collected patients who underwent anteroposterior pelvic radiographs suspected pelvis trauma in Foshan Hospital of Traditional Chinese Medicine between January and June2009.After selected by inclusion criteria and exclusion criteria,1636hips of818adults without symptom of hip were studied. There were398male and420female. The ages of patients ranged from18to80years, average age was43.1years.2. Anteroposterior pelvic radiographs were finished by computed radiography or digital radiography, and radiographs were retrospective analyzed on PACS by2musculoskeletal radiologists. The presence of the following features suggestive of impingement were assessed by means of gross visual inspection:(1)cam-type findings—pistol-grip deformity, focal prominence of the femoral head-neck junction; and (2) pincer-type findings—crossover sign, coxa profunda,and posterior wall sign. The presence of herniation pits of femoral neck was also noted.3.5radiographic findings associated with FAI aforementioned were reread in100examinations randomly selected by the first observer after an interval of at least1months, and they were also read twice independently and with blinding by a second observer. Results:1. Intraobserver agreement was moderate to very good (κ=0.595～0.803in reader1and0.589-0.862in reader2) in rating5radiographic findings, and interobserver agreement was also moderate to very good (κ=0.655～0.810).2. Pistol-grip deformity was seen in8.8%(72/818) examinates or6.7%(110/1636) hip joints, focal prominence of the femoral head-neck junction in4.9%(40/818) examinates or3.2%(53/1636) hip joints, crossover sign in19.7%(161/818) examinates or14.9%(244/1636) hip joints, coxa profunda in25.3%(207/818) examinates or20.0%(328/1636) hip joints, and posterior wall sign in10.3%(84/818) examinates or7.5%(123/1636) hip joints.49.9%examinates had at least1of the5radiographic findings aforementioned, including11.9%examinates had at least1cam-type findings and44.0%had at least1pincer-type findings.3. Radiographic findings were seen in398male and420female examinates, respectively, as follows:pistol-grip deformity,14.8%and3.1%(χ2=35.0, P<0.001);focal prominence of the femoral head-neck junction,7.3%and2.6%(χ2=9.57, P<0.01) crossover sign,22.4%and17.1%(χ2=3.52,P>0.05);coxa profunda,11.3%and38.6%(χ2=80.4,P<0.001); posterior wall sign,4.5%and15.7%(χ2=27.8, P<0.001). The prevalence of crossover sign sign in different age group had significant difference (χ2=30.7, P<0.001),and18～30years group was higher than other age groups (χ2=8.55～16.9, P<0.005; by Bonferroni method, the significant level after adjusted was0.005). The prevalence of posterior wall in different age group also had significant difference (χ2=12.0, P<0.05), but there was no significant difference when we compared these age groups one to one (χ2=0.001～6.51, P>0.005; by Bonferroni method).The prevalence of other3radiographic findings in different age group had no significant difference (χ2=1.83～7.83, P>0.05)4. Herniation pits of femoral neck was seen in7.5%(61/81) examinates or4.2%(69/1636) hip joints. Radiographic findings were seen in examinates with or without herniation pits, respectively, as follows:pistol-grip deformity,23.2%and6.0%, P<0.001. The prevalence of other findings focal was:prominence of the femoral head-neck junction,7.2%and3.1%;crossover sign,14.5%and14.9%;coxa profunda,18.8%and20.1%; posterior wall sign,8.7%and7.5%(all P>0.05, according to sex distribution)Conclusion:1. Radiographic findings associated with FAI are quite common in asymptomatic adults.2. The prevalence of cam-type FAI deformity is higher in males, and the prevalence of coxa profunda and posterior wall sign is higher in females. The prevalence of crossover sign is more common in younger adults.3. The prevalence of pistol-grip deformity in hip joints with herniation pits is higher than hip joints without herniation pits.4. A long-term epidemiological study is needed to determine the relationship between FAI radiographic findings and clinical symptoms of FAI and radiologic hip-joint osteoarthritis.Purpose: 1. To evaluate the correlation between the presence of herniation pits and morphological indicators of cam and pincer FAI based on CT examinations.2.To determine the prevalence of herniation pits of femoral neck in asymptomatic adults using MSCT.3. To discuss the imaging manifestation in herniation pit of femoral neck. Materials and methods:1. We collected consecutive patients who underwent MSCT examination because of abdomen or pelvis symptom in Foshan Hospital of Traditional Chinese Medicine between January2008and January2010.After selected by inclusion criteria and exclusion criteria,700hips of350adults without hip joint symptom were studied. There were204male and146female. The ages of patients ranged from18to81years, average age was46.5years.2. MSCT examinations were finished by16-slice spiral CT, and radiographs were retrospective analyzed on PACS by one musculoskeletal radiologist. The presence and imaging manifestation of herniation pits were assessed.3. The presence of herniation pits and morphological abnormalities of the femoral head and acetabulum was retrospective analyzed by quantitate index as follows:as an indicator for cam FAI, we used the angle a, describing the anterior femoral head-neck junction; as an indicator for pincer FAI, we measured the acetabular version angle, describing the acetabular orientation. Results:1. Herniation pit of femoral neck was seen in18.0%(63/350) examinates or11.3%(79/700) hip joints., and was seen in23.0%(47/204) males and11.0%(16/146) female (χ2=8.41, P<0.05). The prevalence of herniation pit in age group of18-30years,31～40years,41～50years,51～60years, and≥61years was7.2%(5/69),8.5%(6/71),24.3%(18/74),28.3%(17/60) and22.4%(17/76); The prevalence of herniation pit in age group of18～40years and>40was years was7.9%and24.8%respectively (χ2=16.3,P<0.001) 2.108lesions were seen in the79hips, all of them located subcortical zone of femoral head-neck junction, predominantly found in the anterosuperior portion, some were located in the inferior or posterior portion. The lesions were round or oval which greatest diameter was1.8～13mm (average4.2±1.8mm). CT showed a well-defined lesion with a thin clear sclerotic rim, focal cortical perforation was seen in46.3%lesions. The density of lesions ranged from fat to soft tissue.3. The angle a and acetabular version angle in hips with or without herniation pit was49.5°±8.6°and40.7°±6.0°(t=22.6, P<0.001), and18.7°±6.2°and19.3°±5.6°(t=1.90, P>0.05)Conclusion:1. Herniation pits of femoral neck are quite common in asymptomatic adults, especially in elder males. Herniation pit of femoral neck have some specific imaging features, CT can make accurate diagnosis.2. Herniation pits are not only located in anterosuperior portion of femoral head-neck junction, but also in the inferior or posterior portion.3.There is an association between the presence of herniation pit and a high value of angle a. However, the relationships of herniation pit and Cam type FAI need further studies.4.There is not found relationship between herniation pit and Pincer type FAI. |
PDF Full Text Request