Location of Intra- and Extra-articular Hip Impingement Is Different in Patients With Pincer-Type and Mixed-Type Femoroacetabular Impingement Due to Acetabular Retroversion or Protrusio Acetabuli on 3D CT–Based Impingement Simulation

Background: Diagnosis and surgical treatment of hips with different types of pincer femoroacetabular impingement (FAI), such as protrusio acetabuli and acetabular retroversion, remain controversial because actual 3-dimensional (3D) acetabular coverage and location of impingement cannot be studied via standard 2-dimensional imaging. It remains unclear whether pincer hips exhibit intra- or extra-articular FAI. Purpose: (1) To determine the 3D femoral head coverage in these subgroups of pincer FAI, (2) determine the impingement-free range of motion (ROM) through use of osseous models based on 3D-computed tomography (CT) scans, and (3) determine the osseous intra-and extra-articular 3D impingement zones by use of 3D impingement simulation. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This is a retrospective, comparative, controlled study involving 70 hips in 50 patients. There were 24 patients (44 hips) with symptomatic pincer-type or mixed-type FAI and 26 patients (26 hips) with normal hips. Surface models based on 3D-CT scans were reconstructed and compared for hips with acetabular retroversion (30 hips), hips with protrusio acetabuli (14 hips), and normal asymptomatic hips (26 hips). Impingement-free ROM and location of impingement were determined for all hips through use of validated 3D collision detection software based on CT-based 3D models. No abnormal morphologic features of the anterior iliac inferior spine were detected. Results: (1) Mean total femoral head coverage was significantly ( P < .001) increased in hips with protrusio acetabuli (92% ± 7%) and acetabular retroversion (71% ± 5%) compared with normal hips (66% ± 6%). (2) Mean flexion was significantly ( P < .001) decreased in hips with protrusio acetabuli (104°± 9°) and acetabular retroversion (116°± 6°) compared with normal hips (125°± 13°). Mean internal rotation in 90° of flexion was significantly ( P < .001) decreased in hips with protrusio acetabuli (16°± 12°) compared with normal hips (35°± 13°). (3) The prevalence of extra-articular subspine impingement was significantly ( P < .001) higher in hips with acetabular retroversion (87%) compared with hips with protrusio acetabuli (14%) and normal hips (0%) and was combined with intra-articular impingement. The location of anterior impingement differed significantly ( P < .001) between hips with protrusio acetabuli and normal hips. Conclusion: Using CT-based 3D hip models, we found that hips with pincer-type and mixed-type FAI have significantly larger femoral head coverage and different osseous ROM and location of impingement compared with normal hips. Additionally, intra- and extra-articular subspine impingement was detected predominantly in hips with acetabular retroversion. Acetabular rim trimming during hip arthroscopy or open surgical hip dislocation should be performed with caution for these hips. Patient-specific analysis of location of impingement using 3D-CT could theoretically improve diagnosis and planning of surgical treatment.

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The Prevalence of Radiographic Findings of Structural Hip Deformities for Femoroacetabular Impingement in Patients With Hip Pain

The American Journal of Sports Medicine ◽

10.1177/0363546519896355 ◽

2020 ◽

Vol 48 (3) ◽

pp. 647-653 ◽

Cited By ~ 1

Author(s):

Jun Zhou ◽

Heath P. Melugin ◽

Rena F. Hale ◽

Devin P. Leland ◽

Christopher D. Bernard ◽

...

Keyword(s):

Femoroacetabular Impingement ◽

Mixed Type ◽

Imaging Modality ◽

Alpha Angle ◽

Young Patients ◽

Radiographic Finding ◽

Hip Pain ◽

Radiographic Findings ◽

Protrusio Acetabuli ◽

Center Edge

Background: Radiography is the initial imaging modality used to evaluate femoroacetabular impingement (FAI), and diagnostic radiographic findings are well-established. However, the prevalence of these radiographic findings in patients with hip pain is unknown. Purpose: The purpose was 3-fold: (1) to determine the overall prevalence of radiographic FAI deformities in young patients presenting with hip pain, (2) to identify the most common radiographic findings in patients with cam-type FAI, and (3) to identify the most common radiographic findings in patients with pincer-type FAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A geographic database was used to identify patients aged 14 to 50 years with hip pain between the years 2000 to 2016. The following were evaluated on radiographs: cam type: typical pistol grip deformity, alpha angle >55°; pincer type: crossover sign (COS), coxa profunda or protrusio acetabuli, lateral center edge angle (LCEA) ≥40°, Tönnis angle <0°; and mixed type: both cam- and pincer-type features. Posterior wall sign (PWS) and ischial spine sign (ISS) were also evaluated. The prevalence of each was determined. Descriptive statistics were performed on all radiographic variables. Results: There were 1893 patients evaluated, and 1145 patients (60.5%; 1371 hips; 374 male and 771 female; mean age, 28.8 ± 8.4 years) had radiographic findings consistent with FAI. Of these hips, 139 (10.1%) had cam type, 245 (17.9%) had pincer type, and 987 (72.0%) had mixed type. The prevalence of a pistol grip deformity and an alpha angle >55° was 577 (42.1%) and 1069 (78.0%), respectively. The mean alpha angle was 66.9°± 10.5°. The prevalence of pincer-type radiographic findings was the following: COS, 1062 (77.5%); coxa profunda, 844 (61.6%); ISS, 765 (55.8%); PWS, 764 (55.7%); Tönnis angle <0°, 312 (22.8%); LCEA ≥40°, 170 (12.4%); and protrusio acetabuli, 7 (0.5%). Conclusion: The overall prevalence of radiographic findings consistent with FAI in young patients with hip pain was 60.5%. Radiographic findings for mixed-type FAI were the most prevalent. The most common radiographic finding for cam-type FAI was an alpha angle >55°. The most common radiographic finding for pincer-type FAI was the COS.

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Acetabular retroversion in dysplastic hips is associated with decreased 3D femoral head coverage independently from lateral center-edge angle

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-019-03277-6 ◽

2019 ◽

Vol 140 (7) ◽

pp. 869-875 ◽

Cited By ~ 1

Author(s):

Yusuke Kohno ◽

Yasuharu Nakashima ◽

Masanori Fujii ◽

Kyohei Shiomoto ◽

Miho Iwamoto

Keyword(s):

Femoral Head ◽

Acetabular Retroversion ◽

Femoral Head Coverage ◽

Edge Angle ◽

Center Edge ◽

Lateral Center Edge Angle ◽

Center Edge Angle

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Hip arthroscopy for femoroacetabular impingement

EFORT Open Reviews ◽

10.1302/2058-5241.3.170041 ◽

2018 ◽

Vol 3 (4) ◽

pp. 121-129 ◽

Cited By ~ 4

Author(s):

Rima Nasser ◽

Benjamin Domb

Keyword(s):

Surgical Treatment ◽

Femoral Head ◽

Conservative Treatment ◽

Learning Curve ◽

Femoroacetabular Impingement ◽

Hip Arthroscopy ◽

Dynamic Condition ◽

Treatment Options ◽

Femoral Offset ◽

Chondral Damage

The purpose of this article is to give a general overview of femoroacetabular impingement (FAI) and how it could be treated arthroscopically, with some details about indications, the procedure itself and some of the complications associated with the surgery. FAI is a dynamic condition of the hip that can be a source of pain and disability and could potentially lead to arthritis. When symptomatic, and if conservative treatment fails, FAI can be addressed surgically. The goal of surgical treatment for FAI is to recreate the spherical contour of the femoral head, improve femoral offset, normalize coverage of the acetabulum, repair/reconstruct chondral damage and repair/reconstruct the labrum to restore normal mechanics and joint sealing. Advances in equipment and technique have contributed to an increase in the number of hip arthroscopy procedures performed worldwide and have made it one of the more common treatment options for symptomatic FAI. Hip arthroscopy is a procedure with an extremely steep and long learning curve. Cite this article: EFORT Open Rev 2018;3:121-129. DOI: 10.1302/2058-5241.3.170041

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Correlation between radiographic measures of acetabular morphology with 3D femoral head coverage in patients with acetabular retroversion

Acta Orthopaedica ◽

10.3109/17453674.2012.684138 ◽

2012 ◽

Vol 83 (3) ◽

pp. 233-239 ◽

Cited By ~ 27

Author(s):

Benjamin J Hansen ◽

Michael D Harris ◽

Lucas A Anderson ◽

Christopher L Peters ◽

Jeffrey A Weiss ◽

...

Keyword(s):

Femoral Head ◽

Acetabular Retroversion ◽

Femoral Head Coverage ◽

Acetabular Morphology

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Drilling and plombage (core decompression) of a femoral head avascular necrosis

Osteologie/Osteology ◽

10.1055/s-0037-1619921 ◽

2010 ◽

Vol 19 (01) ◽

pp. 36-39 ◽

Cited By ~ 1

Author(s):

P. Chládek ◽

V. Havlas ◽

T. Trc

Keyword(s):

Surgical Treatment ◽

Femoral Head ◽

Core Decompression ◽

Effective Treatment Option ◽

Simple Method ◽

X Ray ◽

Large Femoral Head ◽

Press Fit ◽

Round Shape ◽

Late Stages

SummaryThe treatment of femoral head necrosis of adults is still rather problematic. Conservative treatment has been reported relatively unsuccessful and surgical treatment does not show convincing results either. The most effective seems to be a surgical treatment in early stages of the disease, however, the diagnosis still remains relatively complicated. For the late stages (2B and above) the most effective treatment option is represented by core decompression and vascular grafting. However, drilling and plombage (especially when using press-fit technique) seems to be successful, although not excellent. The authors describe their own method of drilling and plombage of the necrotic zone of the femoral head in 41 patients with X-ray detected necrotic changes of the femoral head. The pain measured by VAS was seen to decrease after surgery in all patients significantly. The Jacobs score was also observed to have increased (from fair to good outcome). We have not observed any large femoral head collapse after surgery, moreover, in some cases an improvement of the round shape of the femoral head was seen. It is important to mention that in all cases femoral heads with existing necrotic changes (flattening or collapse) were treated. Although the clinical improvement after surgery was not significantly high, the method we describe is a safe and simple method of diminishing pain in attempt to prepare the femoral head for further treatment in a future, without significant restriction of the indication due to necrosis (osteochondroplasty, resurfacing, THR).

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Avascular necrosis of the femoral head: Evaluation of hyperbaric oxygen therapy and quality of life

Undersea and Hyperbaric Medicine ◽

10.22462/10.12.2020.5 ◽

2020 ◽

pp. 561-569

Author(s):

Angeliki Chandrinou ◽

◽

Anna Korompeli ◽

Eirini Grammatopoulou ◽

Konstantina Gaitanou ◽

...

Keyword(s):

Quality Of Life ◽

Femoral Head ◽

Avascular Necrosis ◽

Hyperbaric Oxygen ◽

Hyperbaric Oxygen Therapy ◽

Oxygen Therapy ◽

Harris Hip Score ◽

Controlled Study ◽

Second Phase

Introduction: The treatment of avascular necrosis of the femoral head (AVNFH) is based on invasive (e.g., core decompression) and non-invasive methods (e.g., hyperbaric oxygen therapy – HBO2). The purpose of the present study is to evaluate the effect of HBO2 on the quality of life (QoL) of patients with AVNFH. Methods: This was a prospective observational non-controlled study of patients with AVNFH treated by HBO2. It was conducted, with the use of Steinberg scale, on 73 patients with AVNFH Stage I or II who were treated with HBO2. Patients’ QoL was assessed with EuroQol-5D-5L (EQ), Harris Hip Score (mHHS), MAHORN (MHOT), and VAS, in three different phases: before HBO2; after the completion of the first phase (20 HBO2 sessions, up to two months); and after the completion of the second phase (20 HBO2 sessions, up to two months after the first phase). A reassessment was made on the completion of each phase. Ratings were also made after the completion of each phase, over the first five months of follow-up. Results: All 73 patients (67.1% males, 32.9% females, mean age: 40.34, SD ± 9.99) participated in the study. Steinberg scale, mean EQ (F (1, 57) = 25.18, η2 = .306 and F (1, 43) = 43.402, η2 = .502); mHHS (F (1, 61) = 67.13, η2 = .524) and F (1, 43) = 31.84, η2 = .425); MHOT (F (1, 61) = 11.68, η2 = .161) and F (1, 43) = 98.01, η2 = .695); and VAS (F (1, 53) = 24.11, η2 = .313) and F (1, 39) = 45.61, η2 = .539), improved between the first and second measurements and between the second and third measurement accordingly (p < .01). Conclusions: HBO2 treatment does not induce alteration of quality of life and is well tolerated and accepted by patients.

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The association between femoral neck shaft angle and degenerative disease of the hip in a cadaveric model

Hip International ◽

10.1177/11207000211013029 ◽

2021 ◽

pp. 112070002110130

Author(s):

Leigh-Anne Tu ◽

Douglas S Weinberg ◽

Raymond W Liu

Keyword(s):

Femoral Head ◽

Femoral Neck ◽

Hip Osteoarthritis ◽

Volume Ratio ◽

Femoral Head Coverage ◽

Neck Shaft Angle ◽

Hip Arthritis ◽

Femoral Version ◽

Shaft Angle ◽

The Impact

Background: While the influences of acetabular dysplasia and overcoverage on hip arthritis have been studied, the impact of femoral neck-shaft angle on hip arthritis is much more poorly understood. The purpose of this study is to determine if a relationship exists between neck shaft angle and the development of osteoarthritis, a better understanding of which would be useful to surgeons planning osteotomies about the hip. Methods: 533 cadaveric femora and acetabulae (1066 total) from the Hamann-Todd Osteological Collection (Cleveland, OH) were acquired. We measured true neck shaft angle using an AP photograph with the femoral neck parallel to the table. Femoral head volume to acetabular volume ratio, representing femoral head coverage, as well as femoral version were utilised. Correlation between neck shaft angle, femoral version, femoral head coverage and osteoarthritis were evaluated with multiple regression analysis. Results: The mean age and standard deviation was 56 ± 10 years. There were 64 females (12%) and 469 males. There were 380 Caucasians (71%) and 153 African-Americans. Mean femoral version was 11° ± 12° and mean true neck shaft angle was 127.7° ± 5.9° There was a strong correlation between age and arthritis (standardised beta 0.488, p < 0.001). There was a significant correlation between increasing true neck shaft angle and decreasing hip arthritis (standardised beta -0.024, p = 0.038). In the femoral head overcoverage subset, increasing true neck shaft angle was still significantly associated with decreasing hip arthritis (standardised beta −0.088, p = 0.018), although this relationship was not significant with femoral head undercoverage subset. Conclusions: With sufficient acetabular coverage, a relative increase in femoral neck shaft angle within the physiologic range is associated with decreased hip osteoarthritis. Clinical relevance: An understanding of the relationship between femoral neck shaft angle and hip osteoarthritis could be useful for surgeons planning pelvic or proximal femur osteotomies in children.

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LOW DOSE CT SCAN FOLLOWING PERIACETABULAR OSTEOTOMY: ASSESSMENT OF REDUCTION AND CORRELATION WITH RADIOGRAPHIC MEASURES

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120s00213 ◽

2020 ◽

Vol 8 (4_suppl3) ◽

pp. 2325967120S0021

Author(s):

Clarabelle DeVries ◽

Jeffrey J Nepple ◽

Lucas Fowler ◽

Sean Akers ◽

Gail Pashos ◽

...

Keyword(s):

Femoral Head ◽

Normative Data ◽

Low Dose ◽

Periacetabular Osteotomy ◽

Femoral Head Coverage ◽

Edge Angle ◽

Center Edge ◽

Two Sectors ◽

Posterior Sector ◽

Center Edge Angle

Introduction: Periacetabular osteotomy (PAO) has become a favored treatment for symptomatic acetabular dysplasia worldwide. Nevertheless, the parameters for optimal correction to avoid residual instability or iatrogenic impingement have not been defined. Purpose: The purposes of this study were (1) to assess the ability of PAO to correct femoral head coverage to normal ranges as measured by 3D CT scan and (2) to determine if postoperative radiographic parameters of dysplasia are accurate markers of optimal acetabular correction. Methods: A total of 43 hips (in 38 patients, mean 27.7 years, 88.4% female) were enrolled in this prospective cohort study at minimum 1 year after PAO. Postoperative femoral head coverage was assessed via low-dose CT and compared to normative data of asymptomatic hips from the literature. Anterior (3:00-1:15), lateral (1:00-11:00), and posterior (11:25-9:00) sector coverage was defined by averaging the coverage at 15 minute increments in each zone. Postoperative radiographs were utilized to measure lateral center edge angle (LCEA), anterior wall index (AWI), posterior wall index (PWI), and anterior center edge angle (ACEA). Good correction for each sector was defined as coverage from 1 SD below mean to 2 SD above mean. Results: Postoperatively, the anterior sector was normalized in 84% of hips, lateral sector in 84% of hips, and posterior sector in 86% of hips. Sixty-seven percent of hips were corrected to normative range in all three sectors and 19% were corrected in two sectors (86% in at least two sectors). LCEA and PWI showed the highest correlation with lateral and posterior sector coverage with Pearson’s correlation coefficients of 0.67 and 0.71 (p < 0.001), respectively. Weaker correlations were found between anterior coverage and the AWI and ACEA coverage (-0.16 and 0.15, respectively). Good correction was best correlated with the following target values for acetabular correction: LCEA 28°, AI 1°, AWI 0.37, ACEA 32°, and PWI 1.0. Conclusion: PAO can effectively normalize femoral head coverage compared to normative data. Good correction of each sector coverage ranged from 84-86% of cases. The proposed set of radiographic parameter targets were found to be reliable markers of femoral head coverage.

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