Anterior Femoral Head-neck Junction Research Articles

Fluoroscopy-guided triple hip block for patients with hip osteoarthritis: A new approach.

Hip osteoarthritis (OA) is found in approximately 10% of the population and often causes disability and social limitations in elderly patients. Intra-articular injections are among the most frequently applied interventional treatments for the hip joint. Femoral and obturator sensorial nerve blocks have also been reported to be effective for both diagnostic and therapeutic purposes. A single needle insertion was performed for the blockage of the hip joint and sensory branches. For the sensory branch of the femoral nerve, the needle is advanced at nearly a 45-degree angle toward below the anterior inferior iliac spine near the anterolateral edge of the hip joint. For the sensory branch of the obturator nerve, the needle is advanced at nearly an angle of 45 degrees toward the area below the junction of the pubis and ischium. Finally, for joint injection, the same needle was advanced toward the midline of the anterior femoral head-neck junction at a steeper angle, and blocks were applied. Three patients with hip osteoarthritis were injected with this method and well-being was achieved in a 3-month follow-up. We think that blockage of the hip joint and peripheral sensory branches with a single needle insertion is a fast and effective method. However, prospective controlled studies are needed to determine the efficacy and safety of the method.

Radiological morphology variances of transient osteoporosis of the hip.

Although several morphological abnormalities or variances of the hip joint have been proposed to be associated with hip joint degeneration, few studies have investigated any radiological features in patients with transient osteoporosis of the hip (TOH). The purpose of this study is to evaluate the morphological variances of the hip joint in TOH patients radiographically. The TOH group consisted of 31 hips in 31 patients. Age- and gender-matched asymptomatic hips in patients with unilateral osteonecrosis of the femoral head were served as controls. Radiographs and MRI were utilized to examine the following parameters: acetabular dysplasia, acetabular overcoverage, acetabular retroversion, and asphericity of the femoral head-neck junction. Also, localization of the main bone marrow edema (BME) lesion was investigated. TOH patients had a significantly higher incidence of acetabular retroversion (52% with a positive cross-over sign and 29% with posterior wall deficiency) than the controls (13%, P=0.0023; 6%, P=0.043, respectively), which was also confirmed by smaller acetabular anteversion angles on axial MRI. In addition, TOH patients tended to show asphericity of the anterior femoral head-neck junction compared to controls (39% vs. 13%, P=0.040). In 90% of the TOH patients, the main BME lesion was located in the subchondral area of the superior portion of the femoral head, and 77% of the lesion were recognized as a band-like pattern in MRI. Acetabular retroversion and asphericity of the femoral head-neck junction were more commonly observed in TOH patients compared to controls. The main BME lesion was most frequently located in the superior portion of the femoral head.

Diagnosis and management of femoroacetabular impingement

Femoroacetabular impingement (FAI) is a pathological hip condition characterised by abnormal contact between the acetabulum and femoral head–neck junction.1 This can occur within the normal physiological range of motion as a result of osseous abnormalities described as either cam or pincer deformities. Cam deformities describe an abnormal anterosuperior femoral head–neck junction, whereas pincer deformities describe abnormalities in the shape or orientation of the acetabulum (Figure 1). Some patients have both deformities, designated mixed pathology.2 Impingement can also occur in a morphologically normal hip as a result of extreme range of motion activities, such as in ballet dancers or gymnasts. Figure 1 Illustrative lateral view of a hip showing a) cam deformity with additional bone at the anterior femoral headneck junction (shown in red) b) normal hip c) pincer deformity with additional bone at the anterior acetabular rim (shown in red). The deformities in a) and c) cause the femoral neck to impact against the labrum and acetabular rim on flexion and internal rotation. Repeated abutment of the femoral neck against the acetabular rim can result in injury to the labrum and adjacent cartilage.3 Over time these focal lesions may progress to more extensive degenerative disease. There is increasing evidence implicating FAI in the development of osteoarthritis (OA).1,4 In a large population study, cam …

Assessment of Range of Motion and Contact Zones with Commonly Performed Physical Exam Manoeuvers for Femoroacetabular Impingement (FAI): What do These Tests Mean?

Recognition of the magnitude and location of mechanical conflicts is critical to reliably and reproducibly improve functional range of motion and outcomes after surgical treatment of femoroacetabular impingement (FAI). The purpose of this study was to assess the ROM and location of intra-articular and extra-articular mechanical conflict with seven commonly performed physical exam manoeuvers in a cohort of hips with symptomatic FAI. Internal rotation in flexion results in mechanical contact between the anterolateral and anterior femoral head-neck junction with the acetabulum, most commonly at a 1:15 o'clock position. Associated adduction, however, significantly reduces the available internal rotation secondary to contact in the same locations. Straight abduction results in mechanical conflict between the superior femoral head-neck junction and the 12:00 o'clock position of the acetabulum. With external rotation of the hip in various degrees of hip flexion, the potential mechanical impingement is extra-articular between the greater trochanter and ischium or pubic ramus. The zones of proximal femoral and acetabular contact are not intuitive, and may extend significantly more laterally and distally on the femoral head-neck junction than previously appreciated.

Hip Morphological Characteristics and Range of Internal Rotation in Femoroacetabular Impingement

Background: Radiographic features specifically related to the occurrence of femoroacetabular impingement (FAI) appear to be highly prevalent in the asymptomatic population. It remains unclear, however, how these incidental findings should be interpreted clinically and which other variables might differentiate between true incidental findings and preclinical patients. Purpose: To study the association between cam and overall hip morphological characteristics and range of motion in impingement patients, asymptomatic patients (healthy patients with radiographic features specific to FAI), and healthy controls. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Morphological parameters describing cam and overall hip anatomy were obtained from 30 patients (10 per subgroup) with use of 3-dimensional computational methods. In addition, the range of internal rotation in high flexion activities was evaluated, and its relation to hip morphological variables was analyzed in a multivariate regression model. Results: Size of the cam lesion and range of motion significantly differed between groups (P < .05). The range of internal rotation on impingement testing was found to average 27.9° in the healthy control group compared with 21.1° in the asymptomatic control group with radiographic features specific to FAI (P < .001) and 12.3° in the patient group (P < .001). Cam size, acetabular coverage, and femoral version appeared to be predictive variables for the range of internal rotation. Seventy-five percent of variance between patients could be attributed to the combined effect of these 3 variables (R = .86). The range of motion was decreased in cam patients and asymptomatic patients, and early femoroacetabular conflict was not restricted to the area of the cam lesion but involved the entire anterior femoral head-neck junction. Conclusion: Decreased range of motion, as found in FAI, is not solely dependent on the size or even the occurrence of a cam lesion but should be interpreted by taking into account the overall hip anatomy, specifically femoral version and acetabular coverage. Decreased femoral anteversion and increased acetabular coverage add to the risk of early femoroacetabular collision during sports and activities of daily living and therefore appear to be additional predictive variables, besides the finding of a cam lesion, for the risk of clinical hip impingement development. In addition, the findings suggest that surgical osteochondroplasty to restore a normal range of motion may necessitate more excessive bone resection than what simply appears to be a bump on imaging.

Assessment of the α-angle of femoral neck and morphological classification of the anterior femoral head-neck junction on CT-based images in normal Chinese adults

Objective To investigate the normal range of the femoral neck α-angle in normal Chinese adults and classify the morphology of the anterior femoral head-neck junction on CT-based images. Methods Six hundred and fifty-two adult patients (Bilateral: 459 patients, unilateral:193 patients) with the total of 1111 hips (552 left; 559 right, and 654 male; 457 female) without known diseases affecting the proximal femur or symptoms of femoroacetabular impingement (FAI) underwent 64-slice CT scanning for medical purpose with the hip included in the scan range. The volume CT data was used for further analysis in this study. Oblique sagittal plane images paralleling to the axis of the femoral neck were reconstructed with the volume CT data, the image through the middle of the femoral neck was chosen to measure α-angle with AutoCAD2006 software. The morphology of the anterior femoral head-neck junction was classified. Analysis of variance and t-test were performed with SPSS 15.0. Results The mean value of α-angle of all 1111 hips was 38. 2° ±5.3°. The normal range of α-angle in Chinese adults was 28°to 49°.The mean value of left and right α-angles were 38. 0° ±5. 3°and 38.4° ±5. 3° ,respectively, and there was no statistically significant difference between both sides (t = - 1. 231 ,P ＞ 0. 05 ). Males have greater α-angles than females 39. 2° ±5. 8 vs 36. 8° ±4. 1°, with t = -8. 180, P ＜0. 01. There was no statistically significant differences of the α-angles of the seven age groups (F = 1. 765, P ＞ 0. 05 ). In all 1111 proximal femora, 168 were classified as concave type, accounting for 15. 1%, with a mean α-angle of 31.2° ±2. 0°,726 were smooth type, accounting for 65.4%, with a mean α-angle of 37.4° ± 2. 4°, and 217 were flat type, accounting for 19.5%, with a mean α-angle of 46. 4° ±3. 8°. The differences of the α-angles of the three groups reached statistical significance ( F = 1636. 107, P ＜ 0. 01 ). Conclusions The morphology of anterior femoral head-neck junction can be classified into three types: concave type (type Ⅰ ), smooth type (type Ⅱ ) and flat type (type Ⅲ ). This classification could directly reflect α-angle, which helps to recognize the variation of the offset of anterior femoral head-neck junction. This study offers basic data for the diagnosis of FAI. Key words: Femur neck; Femur head; Tomography, X-ray computed; Anthropometry

Femoroacetabular Impingement Treatment Using Arthroscopy and Anterior Approach

Femoroacetabular impingement (FAI) has been identified as a common cause of hip pain in young adults. However, treatment is not well standardized. We retrospectively reviewed 97 patients (100 hips) who underwent osteochondroplasty of the femoral head-neck for FAI using a mini-open anterior Hueter approach with arthroscopic assistance. The mean age of the patients was 33.4 years. The labrum was refixed in 40 hips, partially excised in 39 cases, completely excised in 14 cases, and left intact in seven. Six patients were lost to followup, leaving 91 (94 hips) with a minimum followup of 28.6 months (mean, 58.3 months; range, 28.6-104.4 months). We assessed patients clinically using the nonarthritic hip score (NAHS). One patient had a femoral neck fracture 3 weeks postoperatively. At the last followup, the mean NAHS score increased by 29.1 points (54.8 +/- 12 preoperatively to 83.9 +/- 16 points at last followup). Eleven hips developed osteoarthritis and subsequently had total hip arthroplasty. The best results were obtained in patients younger than 40 years old with a 0 Tönnis grade. Refixation of the labrum did not correlate with a higher NAHS score (87 +/- 11 with refixation versus 82 +/- 19 points without) at the last followup. The technique for FAI treatment allowed direct visualization of the anterior femoral head-neck junction while avoiding surgical dislocation, had a low complication rate, and improved functional scores.

CT assessment of herniation pits: prevalence, characteristics, and potential association with morphological predictors of femoroacetabular impingement

The purpose of this study was to evaluate whether there is a correlation between the presence of herniation pits (HPs) and morphological indicators of cam and pincer femoroacetabular impingement (FAI) based on computed tomography (CT) examinations. CT studies of the pelvis obtained from 200 patients were retrospectively analysed for the presence of HPs and morphological abnormalities of the femoral head and acetabulum. As an indicator for cam FAI, we used the angle alpha, describing the anterior femoral head-neck junction. As an indicator for pincer FAI, we measured the acetabular coverage and the acetabular orientation. Student's t-test was used for statistical analysis. HPs were identified in 85 of the 200 patients. HPs were predominantly found in the superior portion of the proximal anterior femoral neck; some were located in the inferior portion. The angle alpha was significantly larger by 10% in the group with HPs. A correlation between the presence of HPs and morphological indicators of pincer FAI was not found. In conclusion HPs are not only located in the superior portion of the proximal anterior femoral neck, but also in the inferior portion. There is an association between the presence of HPs and a high value of angle alpha.

Vascular Preservation During Arthroscopic Osteoplasty of the Femoral Head-Neck Junction: A Cadaveric Investigation

The goal of this study was to evaluate the risk of vascular injury with arthroscopic osteoplasty of the femoral head-neck junction in a cadaveric model. Eight fresh-frozen cadaveric pelvi were used for arthroscopic osteoplasty of a predetermined 150 degrees arc of resection along the anterior femoral head-neck junction. Postoperatively, injection studies of the deep femoral arteries were performed on all specimens to identify local extravasation of neoprene latex before polymerization as a reproducible indicator of vascular injury. Control specimens included 1 specimen without an osteoplasty and 1 specimen after an "aggressive" open osteoplasty with intention to violate the superior retinacular vessels. The first control specimen showed complete filling of the superior retinacula branches, whereas the second control specimen had evidence of intracapsular latex extravasation. In 7 of 8 experimental specimens, there was near-to-complete filling of the superior and inferior retinacula branches with no signs of latex extravasation. In 1 specimen, no superior retinacular branches were identified; however, no extravasation of the latex material was noted. No injury to the main extracapsular branches of the medial or lateral femoral circumflex vessels was noted. We noted on average 3 superior retinacular vessels penetrating the posterior-superior head-neck junction. There was no evidence of vascular injury to the main blood supply of the femoral head in any of the 8 experimental specimens as noted by latex extravasation. These findings show that arthroscopic osteoplasty can be performed without disrupting the vascular supply to the femoral head. This article has important information on the relation of vascular structures and the resection limit with arthroscopic osteoplasty of the femoral head-neck junction.

Open‐configuration MRI study of femoro‐acetabular impingement

Femoro-acetabular impingement has been proposed as a causative factor of primary hip osteoarthritis. However, primary osteoarthritis of the hip is infrequent in Japan and other Asian countries, even though the hips of Asians frequently sustain impingement, since the Asian lifestyle commonly requires a larger range of hip motion than the Western lifestyle. Therefore, using open-configuration MRI, we investigated whether impingement actually occurs during some traditional Japanese hip positions. The hips of 5 healthy Japanese females were examined in 5 sitting postures: 1) sitting straight; 2) bowing while sitting straight; 3) sitting cross-legged; 4) W-sitting; and 5) squatting. The impingement point was detected by multiple plane reconstructed (MPR) views along with the acetabular rim depicted circumferentially. Impingement was considered to have occurred when, on MRI, the anterior femoral head-neck junction approached the acetabular rim and the femoral head was seen to float from the bottom of the acetabulum with the acetabular rim acting as a fulcrum. Impingement was observed in all volunteers in the W-sitting position, and in 2 of 5 volunteers during squatting. These findings show that impingement occurs frequently during daily Japanese activities. Thus, depending on race, femoro-acetabular impingement might not always cause primary osteoarthritis of the hip. (c) 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1582-1588, 2007.