Relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index, and medial acetabular bone stock
ABSTRACT Knowledge of acetabular anatomy is crucial for cup positioning in total hip replacement. Medial wall thickness of the acetabulum is known to correlate with the degree of developmental dysplasia of the hip (DDH). No data exist about the relationship of routinely used radiographic parameters such as Wiberg's lateral center edge angle (LCE-angle) or Lequesne's acetabular index (AI) with thickness of the medial acetabular wall in the general population. The aim of our study was to clarify the relationship between LCE, AI, and thickness of the medial acetabular wall.
Measurements on plain radiographs (LCE and AI) and axial CT scans (quadrilateral plate acetabular distance QPAD) of 1,201 individuals (2,402 hips) were obtained using a PACS imaging program and statistical analyses were performed.
The mean thickness of the medial acetabulum bone stock (QPAD) was 1.08 mm (95% CI: 1.05-1.10) with a range of 0.1 to 8.8 mm. For pathological values of either the LCE (<20°) or the AI (>12°) the medial acetabular wall showed to be thicker than in radiological normal hips. The overall correlation between coxometric indices and medial acetabular was weak for LCE (r =-0.21. 95% CI [-0.25, -0.17]) and moderate for AI (r = 0.37, [0.33, 0.41]).
We did not find a linear relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index and medial acetabular bone stock in radiological normal hips but medial acetabular wall thickness increases with dysplastic indices.
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ABSTRACT: The rise in popularity of hip arthroscopy has led to a renewed interest in mild hip dysplasia. There is a lack of clarity in the literature regarding both the diagnosis and management of such patients. The aim of this study was to analyse the relative importance of and the inter-relationship between the classically described anatomical indices of dysplasia . One hundred and fifty hips with varying degrees of hip dysplasia were studied. The following were measured: centre-edge (CE), Sharp's and Tönnis angles, acetabular head index (AHI), and acetabular index of depth to width (AIDW). Spearman's correlation coefficient was calculated . Using the CE angle 82 hips were classified as normal and 68 dysplastic. Of the 82 patients with a normal CE angle, 20-39% were dysplastic on at least one other variable. The CE angle did not have a significant correlation to other variables. The remaining four variables showed inter-correlations between 0.26 and 0.54. Overall the Tönnis angle showed the strongest correlation with the other variables. In the patient group with CE angles 21<sup>o</sup> to 25<sup>o</sup> (minor dysplasia) 72% of hips had Tönnis angles greater than 10<sup>o</sup> and 28% had angles greater than or equal to 15<sup>o</sup> indicating the great variability in the level of dysplasia within this group . In patients with mild dysplasia we have shown that measurement of a single anatomical variable may lead to under-diagnosis. We recommend the measurement the CE angle combined with at least one other variable and suggest the use of the Tönnis angle .Hip international: the journal of clinical and experimental research on hip pathology and therapy 01/2014; 24(2). DOI:10.5301/hipint.5000119 · 0.76 Impact Factor
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ABSTRACT: Developmental dysplasia of the hip (DDH) or congenital hip dysplasia (CDH) is the most prevalent developmental childhood hip disorder. It includes a wide spectrum of hip abnormalities ranging from dysplasia to subluxation and complete dislocation of the hip joint. The natural history of neglected DDH in adults is highly variable. The mean age of onset of symptoms is 34.5 years for dysplastic DDH, 32.5 years for low dislocation, 31.2 years for high dislocation with a false acetabulum, and 46.4 years for high dislocation without a false acetabulum. Thorough understanding of the bony and soft tissue deformities induced by dysplasia is crucial for the success of total hip arthroplasty. It is important to evaluate the existing acetabular deformity three-dimensionally, and customize the correction in accordance with the quantity and location of ace tabular deficiencies. Acetabular reconstruction in patients with DDH is challenging. Interpretation of published data is difficult and should be done with caution because most series include patients with different types of hip disease. In general, the complication rate associated with THA is higher in patients with hip dysplasia than it is in patients with osteoarthritis. Overall, clinical and functional outcomes following THA in patients hip dysplasia (DDH) differ from those treated for primary hip osteoarthritis, possibly due to the lower age and level of activity. Although function scores decline with age, the scores for pain and range of motion presented with a statistically significant improvement in the long-term.
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ABSTRACT: The aim of this study was to evaluate the limitations of the Tönnis angle as one of the most commonly used parameters in the diagnosis of acetabular dysplasia, and to explore the feasibility of the modified Tönnis angle in the diagnosis of acetabular dysplasia. A total of 224 patients (120 females and 104 males) with 448 hips, aged between 15 and 83 years (median, 45.0 years), were selected for the measurement of the center-edge (CE) and Tönnis angles. To evaluate the relative position of the medial edge of the acetabular sourcil, a new parameter, known as the center-medial-edge (CME) angle, was designed. As an improvement of the Tönnis angle, a new angle preliminarily termed the modified Tönnis angle was created. In addition, the degree of clarity of the medial edge of the acetabular sourcil on radiograph was evaluated, and the hips were divided into the clear-edge and blurred-edge groups. The hips belonging to the blurred-edge group could not be used for Tönnis angle measurements. All measurements were performed digitally using the tool of the picture-archiving communication system. Among the 448 acetabular sourcils, 142 had a blurred medial edge (31.7%). The mean value of the CME angle was 37.94°, with a range of 21.76-63.99°. The 95% prediction interval of the modified Tönnis angle was estimated to be -6.39 to 11.73°. The correlation coefficients were -0.838 between the CE and Tönnis angles, 0.889 between the Tönnis and modified Tönnis angles and -0.905 between the CE and modified Tönnis angles. In conclusion, the modified Tönnis angle can substitute for the Tönnis angle without joint space narrowing and subluxation of the hip, particularly when the Tönnis angle cannot be measured due to a blurred medial edge of the acetabular sourcil on pelvic radiograph.Experimental and therapeutic medicine 12/2014; 8(6):1934-1938. DOI:10.3892/etm.2014.2009 · 0.94 Impact Factor