scholarly journals Acetabular morphology in slipped capital femoral epiphysis: comparison at treatment onset and skeletal maturity

2018 ◽  
Vol 12 (5) ◽  
pp. 444-453 ◽  
Author(s):  
D. A. Maranho ◽  
A. Davila-Parrilla ◽  
P. E. Miller ◽  
Y.-J. Kim ◽  
E. N. Novais ◽  
...  
Keyword(s):  
Acetabular Dysplasia ◽  
Skeletal Maturity ◽  
Slipped Capital Femoral Epiphysis ◽  
Alpha Angle ◽  
Width Ratio ◽  
Acetabular Coverage ◽  
Neck Shaft Angle ◽  
Factors Associated ◽  
Acetabular Morphology

Purpose To investigate changes in acetabular morphology during the follow-up of slipped capital femoral epiphysis (SCFE) and search for factors associated with acetabular dysplasia at skeletal maturity. Methods We evaluated 108 patients with unilateral SCFE (mean age at slip, 12.3 years sd 1.7) to skeletal maturity, with a minimum follow-up of two years (median 4.5 years; interquartile range 3.2 to 6.2). Acetabular parameters obtained from initial and most recent radiographs included the lateral centre-edge angle (LCEA), Tönnis angle (TA) and acetabular depth-width ratio (ADR). Acetabular dysplasia was considered for LCEA < 20° or TA > 10°. Femoral parameters consisted of the most recent head diameter, neck-shaft angle, neck length, articulotrochanteric distance and alpha angle. Results At SCFE onset, the affected hip showed a slightly lower LCEA (26.4° sd 6.1° versus 27.3° sd 5.7°; p = 0.01) and ADR (330 sd 30 versus 340 sd 30; p < 0.001) compared with the uninvolved hip. At final follow-up, the affected hip showed lower LCEA (24.5° sd 7.6° versus 28.8°sd 6.6°; p < 0.001) and ADR (330 sd 40 versus 350 sd 40; p < 0.001), and TA was larger (5.5° sd 5.4° versus 2.3° sd 4.2°; p < 0.001) compared with the uninvolved hip. Acetabular dysplasia was observed in 27 (25%) of 108 hips with SCFE. Femoral head overgrowth, age at slip and SCFE severity were independent factors associated with acetabular dysplasia (p < 0.05). Conclusion Acetabular coverage and depth are not increased in SCFE, and the acetabular coverage tends to decrease up to skeletal maturity. A potential disturbance in the acetabular growth and remodelling exists mainly for young children with severe SCFE, and a potential for acetabular insufficiency may be observed at the diagnosis and follow-up of SCFE. Level of Evidence Prognostic Level IV

scholarly journals BORDERLINE ACETABULAR DYSPLASIA: THREE-DIMENSIONAL DEFORMITY PREDICTORS OF THE DIAGNOSIS OF SYMPTOMATIC INSTABILITY TREATED WITH PERIACETABULAR OSTEOTOMY

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0016
Author(s):  
Elizabeth Graesser ◽  
Maria Schwabe ◽  
Cecilia Pascual Garrido ◽  
John C. Clohisy ◽  
Jeffrey J. Nepple
Keyword(s):  
Low Dose ◽  
Acetabular Dysplasia ◽  
Periacetabular Osteotomy ◽  
Alpha Angle ◽  
Three Dimensional ◽  
Acetabular Coverage ◽  
Low Dose Ct ◽  
Femoral Version ◽  
Center Edge ◽  
Hip Morphology

Introduction: Borderline acetabular dysplasia is classically defined as a lateral center edge angle (LCEA) of 20-25 degrees. The optimal treatment strategy in this patient group remains controversial, with some patients having primarily hip instability-based symptoms, while others have primarily impingement-based symptoms (non-instability). The purpose of the current study was to define the 3D characteristics on low-dose CT that differentiate patients with instability symptoms from those without instability in the setting of borderline acetabular dysplasia. Methods: Seventy consecutive hips with borderline acetabular dysplasia undergoing surgical treatment were included in the current study. All patients underwent low-dose pelvic CT with femoral version assessment for preoperative planning. CT measurements included alpha angle and radial acetabular coverage (RAC) at standardized clockface positions (9:00-posterior to 3:00-anterior), central and cranial acetabular version. RAC was assessed in three sectors (anterior, superior, and posterior) and defined (relative to published normative data) as normal (-1 SD, +1 SD), undercoverage (<-1 SD), or overcoverage (>+1 SD). Statistical analysis was performed to compare the CT characteristics of the symptomatic instability and non-instability groups. Results: Of the 70 hips, 62.9% had the diagnosis of symptomatic instability, while 37.1% had no instability symptoms. Hips with instability (compared to non-instability) had significantly lower alpha angle (maximal difference at 1:00 - 47.0° vs. 59.4°), increased femoral version (22.3° vs. 15.3°), and decreased radial acetabular coverage (maximal difference at 1:00 – 59.9% vs. 62.2%) (all p<0.001). Multivariate analysis identified femoral version (OR 1.1, p=0.02), alpha angle at 1:00 (OR 0.91, p=0.02), and RAC at 1:00 (OR 0.46, p=0.003) as independent predictors of the presence of instability. The model combining these three factors had excellent predictive probability with a c-statistic 0.92. Conclusion: We found significant differences in the 3D hip morphology of the symptomatic instability and non-instability subgroups within the borderline dysplasia cohort. In the setting of borderline dysplasia, three-dimensional deformity characterization with low-dose CT allowed for differentiation of patients diagnosed with underlying instability vs. non-instability. Femoral version, alpha angle at 1:00, and radial acetabular coverage at 1:00 were identified as independent predictors of diagnosis in borderline acetabular dysplasia. Summary: This study attempts to define 3D CT characteristics to help distinguish between patients with impingement-based vs instability-based symptoms of borderline acetabular dysplasia.

scholarly journals The acetabulum in healed Legg–Calvé–Perthes disease is cranially retroverted and associated with global reduction of femoral head coverage: a matched-cohort study

2020 ◽  
Vol 7 (1) ◽  
pp. 49-56
Author(s):  
Daniel A Maranho ◽  
Mariana Ferrer ◽  
Leslie A Kalish ◽  
Whitney Hovater ◽  
Eduardo N Novais
Keyword(s):  
Femoral Head ◽  
Ct Scan ◽  
Skeletal Maturity ◽  
Perthes Disease ◽  
Width Ratio ◽  
Acetabular Version ◽  
Center Edge ◽  
Acetabular Morphology ◽  
Hip Disease ◽  
Ct Evaluation

Abstract To evaluate the acetabular morphology in healed Legg–Calvé–Perthes disease after skeletal maturity using computed tomography (CT) scan and to compare with matched controls. We identified 33 (37 hips) patients with healed Legg–Calvé–Perthes disease and closed triradiate cartilage who underwent pelvic CT scan. Each patient was matched based on sex, age and side to a subject with no history of hip disease who had undergone pelvic CT evaluation because of abdominal pain. Both cohorts had 23 (70%) males and mean age of 16.4–16.5 ± 3.6 years. Two independent readers assessed lateral center-edge angle (LCEA), acetabular inclination angle (IA), acetabular depth-width ratio (ADR), acetabular version 10 mm below the dome (cranial) and at the acetabular center and anterior (AASA) and posterior acetabular sector angles (PASA). All measurements had good to excellent interobserver agreement (intraclass coefficients ≥ 0.87). The hips in the Legg–Calvé–Perthes disease cohort had a smaller mean ± standard deviation (SD) superior, anterior and posterior acetabular coverage as assessed by LCEA (13.2° ± 10.7° versus 28.2° ± 3.4°; P &lt; 0.0001), IA (11.6° ± 6.7° versus 3.5° ± 2.8°; P &lt; 0.0001), AASA (52.4° ± 9.5° versus 59.3° ± 5.0°; P = 0.001) and PASA (79.3° ± 5.9° versus 92.3° ± 5.5°; P &lt; 0.0001) compared with controls. The acetabulum was shallower (ADR 287 ± 45 versus 323 ± 28; P = 0.0002) and the acetabular version was decreased cranially (0.4°±9.2° versus 8.2°±6.8°; P = 0.0002) and at the acetabular center (13.7°±5.1° versus 17.2° ±3.8°; P = 0.004) in Legg–Calvé–Perthes disease hips. After skeletal maturity, hips with healed Legg–Calvé–Perthes disease have shallower and more cranially retroverted acetabula, with globally reduced coverage of the femoral head compared with age-, sex- and side-matched control hips.

scholarly journals The effects of residual hip deformity on coronal alignment of the lower extremity in patients with unilateral slipped capital femoral epiphysis

2018 ◽  
Vol 12 (6) ◽  
pp. 599-605
Author(s):  
H. Ucpunar ◽  
S. K. Tas ◽  
Y. Camurcu ◽  
H. Sofu ◽  
M. Mert ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Skeletal Maturity ◽  
Slipped Capital Femoral Epiphysis ◽  
Orientation Angle ◽  
Joint Line ◽  
Leg Length ◽  
Coronal Alignment ◽  
Level Of Evidence ◽  
Neck Shaft Angle ◽  
Retrospective Comparative Study

Purpose The aim of our explorative study was to compare the differences in the coronal alignments of the hip, knee and ankle on the slip side and non-slip sides in patients with slipped capital femoral epiphysis (SCFE). Methods The study group consisted of 28 patients. On the full-length standing radiographs, measurements of articulo-trochanteric distance (ATD), neck-shaft angle (NSA), femoral offset, hip-knee-ankle axis, femur-tibial angle, mechanical axis deviation ratio (MAD-r), anatomical medial proximal femoral angle (aMPFA), mechanical lateral proximal femoral angle (mLPFA), anatomical lateral distal femoral angle (aLDFA), mechanical lateral distal femoral angle (mLDFA), knee joint line congruency angle, mechanical medial proximal tibial angle (mMPTA), mechanical lateral distal tibial angle (mLDTA), ankle joint line orientation angle (AJOA), and leg length discrepancy (LLD) were performed. The data from the slip side were compared with those from the non-slip side. Results At skeletal maturity, there were significant differences between the slip side and non-slip side in ATD (p <0.001), NSA (p <0.001), MAD-r (p <0.001), aMPFA (p <0.001), aLDFA (p = 0.03), mLDFA (p = 0.04), mLDTA (p = 0.02), AJOA (p <0.001) and LLD (p<0.001). Conclusion Residual deformity in the proximal femur after epiphyseal slip and premature epiphysiodesis could cause changes in the coronal alignment of the lower extremity. We can add lower extremity alignment examination to follow-up protocol to rule out secondary problems in patients with SCFE. Level of Evidence Level III, retrospective comparative study

scholarly journals Defining the Borderline Hip: High Variability in Acetabular Coverage and Femoral Deformity

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0034
Author(s):  
Maria Schwabe ◽  
Cecilia Pascual-Garrido ◽  
John Clohisy ◽  
Elizabeth Graesser Jeffrey Nepple
Keyword(s):  
Low Dose ◽  
Acetabular Dysplasia ◽  
Alpha Angle ◽  
Acetabular Coverage ◽  
Femoral Version ◽  
Center Edge ◽  
Text Figure ◽  
Femoral Deformity ◽  
The Mean ◽  
Center Edge Angle

Objectives: Borderline acetabular dysplasia is radiographically defined as a lateral center edge angle (LCEA) of 20-25 degrees. It is well accepted that some borderline hips have instability while others have primarily impingement. The optimal management of borderline dysplasia is challenging and particularly complex due to the anatomic variability that exists among patients but has not been well characterized. The purpose of this current study was to investigate the variability in hip deformity present on low-dose CT in a cohort of patients with symptomatic borderline acetabular dysplasia. Methods: Seventy consecutive hips with borderline acetabular dysplasia undergoing surgical treatment were included in the current study. Radiographic evaluation included LCEA, acetabular inclination, anterior center edge angle (ACEA), and alpha angles on AP, Dunn, and frog views. All patients underwent low-dose pelvic CT for preoperative planning. Femoral deformity was assessed with femoral version, alpha angle (measured at 1:00 increments), and maximum alpha angle. Radial acetabular coverage was calculated according to standardized clockface positions [measured from 8:00 (posterior) to 4:00 (anterior)] and defined as normal, undercoverage, or overcoverage relative to 1 SD from the mean of normative values. Results: The mean LCEA was 22.1+1.4, while the mean acetabular inclination was 10.3+3.3. The mean ACEA in the group was 25.3+5.8 (range 10.1-43.9), with 16% having an ACEA < 20 and 50% having an ACEA < 25. The mean femoral version was 17.9° (range -4° to 59°). The mean maximal alpha angle was 57.2° (range 43° to 81°) with 61.4% greater than 55°. Lateral coverage (RAC at 12:00) was deficient in 74.1% of cases. Anterior coverage (RAC at 2:00) was highly variable with 17.1% undercoverage, 72.9% normal, and 10.0% overcoverage. Posterior coverage (RAC at 10:00) was also highly variable with 30.0% undercoverage, 62.9% normal, and 7.1% overcoverage. The three most common patterns of coverage were: isolated lateral undercoverage (31.4%), normal coverage (18.6%), and lateral and posterior undercoverage (17.1%). Conclusion: Patients with borderline acetabular dysplasia demonstrate highly variable three-dimensional deformities including anterior, lateral, and posterior acetabular coverage, femoral version, and alpha angle. Comprehensive deformity characterization in the population is important to guide diagnosis and treatment decisions. [Figure: see text][Figure: see text][Figure: see text]

scholarly journals Is Hip Arthroscopy an Adequate Therapy for the Borderline Dysplastic Hip? Correlation Between Radiologic Findings and Clinical Outcomes

2020 ◽  
Vol 8 (5) ◽  
pp. 232596712092085
Author(s):  
Alexander Zimmerer ◽  
Marco M. Schneider ◽  
Rainer Nietschke ◽  
Wolfgang Miehlke ◽  
Christian Sobau
Keyword(s):  
Clinical Outcomes ◽  
Hip Dysplasia ◽  
Arthroscopic Surgery ◽  
Alpha Angle ◽  
Neck Shaft Angle ◽  
Center Edge ◽  
Femoroacetabular Impingement Syndrome ◽  
Fear Index ◽  
Cluster 2

Background: Recent studies have shown that assessment of the lateral center-edge angle (LCEA) between 18° and 25° is not sufficient to adequately classify mildly dysplastic hips and that further radiological features should be considered. However, no correlation between different morphologic features and clinical outcomes has been investigated so far. Purpose: To analyze the clinical outcomes of patients with different subtypes of borderline dysplastic hips who underwent arthroscopic surgery. Study Design: Cohort study; Level of evidence, 3. Methods: We examined patients with an LCEA between 18° and 25° who underwent arthroscopic treatment for femoroacetabular impingement syndrome between January 2015 and December 2016. A hierarchical cluster analysis was performed to identify hip morphologic subtypes according to radiographic parameters, including the LCEA, femoro-epiphyseal acetabular roof (FEAR) index, anterior and posterior wall indices (AWI and PWI), Tönnis angle, alpha angle, and femoral neck-shaft angle. In addition, the International Hip Outcome Tool 12 (iHOT-12) and a visual analog scale (VAS) for pain were applied preoperatively and at follow-up, and the results were compared among the different clusters. Previously reported minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) values were used to determine clinically significant improvements. Results: A total of 40 patients were identified. Of these, 36 patients were available for evaluation at a mean follow-up of 43.8 months. In total, 4 sex-independent clusters with different morphologic patterns of the hip were identified: cluster 1, unstable anterolateral deficiency (FEAR index >2°, AWI <0.35); cluster 2, stable anterolateral deficiency (FEAR index <2°, AWI <0.35); cluster 3, stable lateral deficiency (FEAR index >2°, normal AWI and PWI); and cluster 4, stable posterolateral deficiency (FEAR index <2°, PWI <0.85). At follow-up, clusters 1, 2, and 3 showed significantly improved iHOT-12 ( P < .0001) and VAS pain ( P < .0001) scores, and cluster 4 showed no significant improvements. The MCID of 15.2 points was achieved by all patients in clusters 2 and 3, by 63% of patients in cluster 1, and by 23% of patients in cluster 4. Clusters 2 and 3 differed significantly from clusters 1 and 4 ( P = .02). A postoperative PASS score of 60 was achieved by all patients in cluster 3, by 86% of patients in cluster 2, by 63% of patients in cluster 1, and by 20% of patients in cluster 4. The differences between the groups were statistically significant ( P = .01). Conclusion: Arthroscopic surgery yielded good results in the treatment of stable borderline hip dysplasia with anterolateral and lateral deficiency. In contrast, borderline hip dysplasia with acetabular retroversion showed no improvements after arthroscopic therapy. This study underlines the need for an accurate analysis of all possible radiological signs to adequately classify borderline dysplastic hips.

scholarly journals Long-term evolution of slipped capital femoral epiphysis treated by in situ fixation: a 26 years follow-up of 11 hips

2014 ◽  
Vol 6 (2) ◽  
Author(s):  
Jérôme Murgier ◽  
Jérôme Sales de Gauzy ◽  
Fouad C. Jabbour ◽  
Xavier Bayle Iniguez ◽  
Etienne Cavaignac ◽  
...  
Keyword(s):  
Treatment Options ◽  
Slipped Capital Femoral Epiphysis ◽  
Alpha Angle ◽  
Hip Osteoarthritis ◽  
Slip Angle ◽  
Radiographic Outcomes ◽  
Oxford Hip Score

Slipped capital femoral epiphysis (SFCE) may lead to femoro acetabular impingement and long-term function impairment, depending on initial displacement and treatment. There are several therapeutic options which include <em>in situ f</em>ixation (ISF). The objective of this study was to evaluate long-term functional and radiographic outcomes of patients with SFCE treated with ISF. We conducted a single-center, retrospective study evaluating the clinical and radiographic outcomes of SCFE<em> in situ</em> fixation with a mean follow-up of 26 years (10- 47). Analysis of preoperative and last follow up radiographs was performed. The functional status of the hip was evaluated according to the Oxford hip score-12 and the radiographic osteoarthritis stage was rated according to Tönnis classification. Signs of femoro acetabular impingement were sought. Ten patients (11 hips) were included. The average initial slip was 33.5° (10-62). At final follow up, the average Oxford hip score was 19.3 (12-37), it was good for groups who had a small initial slip (16.7) or moderate (17) and fair for the severe group (27). Average Tönnis grade was 1.3 (0- 3). The average alpha angle was 65.3° (50- 80°). Femoro acetabular impingement was likely in 100% of patients with severe slip, in 50% of patients with moderate slip and in 33% of patients with a slight slip. <em>In situ</em> fixation generated poor functional results, substantial hip osteoarthritis and potential femoro acetabular impingement in moderate to severe SCFE’s. However, in cases with minor displacement, functional and radiographic results are satisfactory. The cut off seems to be around 30° slip angle, above which other treatment options should be considered.

scholarly journals RADIOGRAPHIC FOLLOW-UP AFTER MILD SLIPPED CAPITAL FEMORAL EPIPHYSIS: WHAT IS THE INCIDENCE OF SUBSEQUENT SURGERY FOR FEMORACETABULAR IMPINGEMENT?

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0017
Author(s):  
Anne Skelton ◽  
Rachael Martino ◽  
Stephanie Mayer ◽  
Courtney Selberg
Keyword(s):  
Demographic Data ◽  
Slipped Capital Femoral Epiphysis ◽  
Alpha Angle ◽  
Binary Logistic Regression ◽  
Slip Angle ◽  
Logistic Regression Models ◽  
Joint Preserving Surgery ◽  
Radiographic Measurements ◽  
Additional Surgery

Background: Slipped capital femoral epiphysis (SCFE) is characterized by translation of the proximal femoral epiphysis posterior and medial relative to the metaphysis. The gold standard treatment of mild SCFE, defined as a slip angle <30°, remains in-situ pinning (ISP) to stabilize the epiphysis in its current position after slippage. Methods: 127 hips from 113 individuals met inclusion criteria: mild SCFE (Southwick angle <30°) that underwent ISP with available pre- and post-procedure radiographs. Medical records were reviewed to collect demographic data, preoperative symptoms, surgical details, radiographic measurements, and post-operative follow-up. Six hips were identified as having undergone additional joint preserving surgery of the hip (JPSH) while seven other hips were identified as having undergone screw removal and/or replacement within two years of initial ISP. Anterior-posterior (AP) and frog-leg lateral alpha angles, femoral epiphyseal-metaphyseal offset angle, and Southwick angle were all measured preoperatively, post-operatively, and at final radiographic follow-up. Chi-squared analyses, binary logistic regression models and Kruskal-Wallis tests were used to evaluate the association between clinical and radiographic parameters and the occurrence of additional surgery or screw failure. Results: Demographic variables, including age, body mass index, prodrome pain, sex, laterality, and chronicity were not found to significantly influence the likelihood of additional surgery. Preoperative AP alpha angle, frog-lateral alpha angle, epiphyseal-metaphyseal offset angle, and Southwick angle did not significantly impact the likelihood of additional surgery or screw failure. Radiographic measurements taken after ISP demonstrated that AP alpha angle significantly increased the likelihood of additional surgery. For every one degree increase, the likelihood of additional surgery increased 1.091 times (average 70.264° for no additional surgery and 82.333° for additional surgery, p=0.017). Conclusion: Mild SCFE can progress to residual pain and limited hip motion even after initial treatment with ISP. Of our cohort of 127 hips, six (4.72%) went on to have secondary JPSH while an additional seven (5.51%) presented with screw failure within two years of initial ISP. Increased AP alpha angle after ISP was correlated with an increased likelihood of secondary JPSH. This increased AP alpha angle may contribute to intra-articular pathology due to CAM-type morphology which may lead to the necessity of JPSH. These findings suggest that patients with increased AP alpha angle after ISP may need to be followed long-term for the development of further joint symptoms and may need to be counseled after ISP for mild SCFE for the risk of secondary JPSH. Tables/Figures: [Table: see text][Table: see text][Table: see text]

scholarly journals Acetabular Dysplasia: Three-Dimensional Deformity Predictors of the Diagnosis of Symptomatic Instability Treated with Periacetabular Osteotomy

2020 ◽  
Vol 8 (7_suppl6) ◽  
pp. 2325967120S0042
Author(s):  
Maria Schwabe ◽  
Cecilia Pascual-Garrido ◽  
John Clohisy ◽  
Elizabeth Graesser ◽  
Jeffrey Nepple
Keyword(s):  
Low Dose ◽  
Acetabular Dysplasia ◽  
Periacetabular Osteotomy ◽  
Alpha Angle ◽  
Three Dimensional ◽  
Acetabular Coverage ◽  
Low Dose Ct ◽  
Femoral Version ◽  
Center Edge ◽  
Hip Morphology

Objectives: Borderline acetabular dysplasia is classically defined as a lateral center edge angle (LCEA) of 20-25 degrees. The optimal treatment strategy in this patient group remains controversial, with some patients having primarily hip instability-based symptoms, while others have primarily impingement-based symptoms (non-instability). The purpose of the current study was to define the 3D characteristics on low-dose CT that differentiate patients with instability symptoms from those without instability in the setting of borderline acetabular dysplasia. Methods: Seventy consecutive hips with borderline acetabular dysplasia undergoing surgical treatment were included in the current study. All patients underwent low-dose pelvic CT with femoral version assessment for preoperative planning. CT measurements included alpha angle and radial acetabular coverage (RAC) at standardized clockface positions (9:00-posterior to 3:00-anterior), central and cranial acetabular version. RAC was assessed in three sectors (anterior, superior, and posterior) and defined (relative to published normative data) as normal (-1 SD, +1 SD), undercoverage (<-1 SD), or overcoverage (>+1 SD). Statistical analysis was performed to compare the CT characteristics of the symptomatic instability and non-instability groups. Results: Of the 70 hips, 62.9% had the diagnosis of symptomatic instability, while 37.1% had no instability symptoms. Hips with instability (compared to non-instability) had significantly lower alpha angle (maximal difference at 1:00 - 47.0° vs. 59.4°), increased femoral version (22.3° vs. 15.3°), and decreased radial acetabular coverage (maximal difference at 1:00 – 59.9% vs. 62.2%) (all p<0.001). Multivariate analysis identified femoral version (OR 1.1, p=0.02), alpha angle at 1:00 (OR 0.91, p=0.02), and RAC at 1:00 (OR 0.46, p=0.003) as independent predictors of the presence of instability. The model combining these three factors had excellent predictive probability with a c-statistic 0.92. Conclusion: We found significant differences in the 3D hip morphology of the symptomatic instability and non-instability subgroups within the borderline dysplasia cohort. In the setting of borderline dysplasia, three-dimensional deformity characterization with low-dose CT allowed for differentiation of patients diagnosed with underlying instability vs. non-instability. Femoral version, alpha angle at 1:00, and radial acetabular coverage at 1:00 were identified as independent predictors of diagnosis in borderline acetabular dysplasia.

scholarly journals DEFINING THE BORDERLINE HIP: HIGH VARIABILITY IN ACETABULAR COVERAGE AND FEMORAL DEFORMITY

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0021
Author(s):  
Elizabeth Graesser ◽  
Maria Schwabe ◽  
Cecilia Pascual-Garrido ◽  
John C Clohisy ◽  
Jeffrey J Nepple
Keyword(s):  
Low Dose ◽  
Acetabular Dysplasia ◽  
Alpha Angle ◽  
Acetabular Coverage ◽  
Edge Angle ◽  
Femoral Version ◽  
Center Edge ◽  
Femoral Deformity ◽  
The Mean ◽  
Center Edge Angle

Introduction Borderline acetabular dysplasia is radiographically defined as a lateral center edge angle (LCEA) of 20-25 degrees. It is well accepted that some borderline hips have instability while others have primarily impingement. The optimal management of borderline dysplasia is challenging and particularly complex due to the anatomic variability that exists among patients but has not been well characterized. Purpose The purpose of this current study was to investigate the variability in hip deformity present on low-dose CT in a cohort of patients with symptomatic borderline acetabular dysplasia. Methods Seventy consecutive hips with borderline acetabular dysplasia undergoing surgical treatment were included in the current study. Radiographic evaluation included LCEA, acetabular inclination, anterior center edge angle (ACEA), and alpha angles on AP, Dunn, and frog views. All patients underwent low-dose pelvic CT for preoperative planning. Femoral deformity was assessed with femoral version, alpha angle (measured at 1:00 increments), and maximum alpha angle. Radial acetabular coverage was calculated according to standardized clock-face positions [measured from 8:00 (posterior) to 4:00 (anterior)] and defined as normal, under-coverage, or over-coverage relative to 1 SD from the mean of normative values. Results The mean LCEA was 22.1±1.4, while the mean acetabular inclination was 10.3±3.3. The mean ACEA in the group was 25.3±5.8 (range 10.1-43.9), with 16% having an ACEA ≤ 20 and 50% having an ACEA ≤ 25. The mean femoral version was 17.9° (range -4° to 59°). The mean maximal alpha angle was 57.2° (range 43° to 81°) with 61.4% greater than 55°. Lateral coverage (RAC at 12:00) was deficient in 74.1% of cases. Anterior coverage (RAC at 2:00) was highly variable with 17.1% under-coverage, 72.9% normal, and 10.0% over-coverage. Posterior coverage (RAC at 10:00) was also highly variable with 30.0% under-coverage, 62.9% normal, and 7.1% over-coverage. The three most common patterns of coverage were: isolated lateral under-coverage (31.4%), normal coverage (18.6%), and lateral and posterior under-coverage (17.1%). Discussion Patients with borderline acetabular dysplasia demonstrate highly variable three-dimensional deformities including anterior, lateral, and posterior acetabular coverage, femoral version, and alpha angle. Comprehensive deformity characterization in the population is important to guide diagnosis and treatment decisions.

Does acetabular coverage influence the clinical outcome of arthroscopically treated cam-type femoroacetabular impingement (FAI)?

2018 ◽  
Vol 100-B (7) ◽  
pp. 831-838 ◽  
Author(s):  
M. M. Ibrahim ◽  
S. Poitras ◽  
A. C. Bunting ◽  
E. Sandoval ◽  
P. E. Beaulé
Keyword(s):  
Functional Outcome ◽  
Femoroacetabular Impingement ◽  
Alpha Angle ◽  
3D Analysis ◽  
Acetabular Coverage ◽  
Crossover Sign ◽  
Significant Difference ◽  
Patient Reported ◽  
Outcome Scores

Aims What represents clinically significant acetabular undercoverage in patients with symptomatic cam-type femoroacetabular impingement (FAI) remains controversial. The aim of this study was to examine the influence of the degree of acetabular coverage on the functional outcome of patients treated arthroscopically for cam-type FAI. Patients and Methods Between October 2005 and June 2016, 88 patients (97 hips) underwent arthroscopic cam resection and concomitant labral debridement and/or refixation. There were 57 male and 31 female patients with a mean age of 31.0 years (17.0 to 48.5) and a mean body mass index (BMI) of 25.4 kg/m2 (18.9 to 34.9). We used the Hip2Norm, an object-oriented-platform program, to perform 3D analysis of hip joint morphology using 2D anteroposterior pelvic radiographs. The lateral centre-edge angle, anterior coverage, posterior coverage, total femoral coverage, and alpha angle were measured for each hip. The presence or absence of crossover sign, posterior wall sign, and the value of acetabular retroversion index were identified automatically by Hip2Norm. Patient-reported outcome scores were collected preoperatively and at final follow-up with the Hip Disability and Osteoarthritis Outcome Score (HOOS). Results At a mean follow-up of 2.7 years (1 to 8, sd 1.6), all functional outcome scores significantly improved overall. Radiographically, only preoperative anterior coverage had a negative correlation with the improvement of the HOOS symptom subscale (r = -0.28, p = 0.005). No significant difference in relative change in HOOS subscale scores was found according to the presence or absence of radiographic signs of retroversion. Discussion Our study demonstrated the anterior coverage as an important modifier influencing the functional outcome of arthroscopically treated cam-type FAI. Cite this article: Bone Joint J 2018;100-B:831–8.

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