Failures in the management of congenital hip displacement in the newborn.
(65/715)
Congenital hip displacement in the newborn presents in two forms: (1) Those babies in whom the capsule of the hip-joint is mechanically stretched. Spontaneous reduction and recovery is high in this group, if the babies are nursed in the prone posture with double nappies (Fig 5). (2) One in a thousand babies is born with infolding of the posterior capsule and secondary contracture of the anterior capsule. This soft tissue deformation occurs in varying degrees, but it frequently prevents spontaneous reduction. Most of these cases are missed and present as infantile congenital hip displacements, when the child is 12-18 months old. In those who are unfortunate enough to be detected and treated conservatively, in the first year of life, there is a high risk of iatrogenic bony deformation. For, as in talipes equinovarus, the bony components of the neonatal hip-joint are more susceptible to mechanical compression than the soft tissue structures. (+info)
The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement.
(66/715)
Impingement by prominence at the femoral head-neck junction on the anterior acetabular rim may cause early osteoarthritis. Our aim was to develop a simple method to describe concavity at this junction, and then to test it by its ability to distinguish quantitatively a group of patients with clinical evidence of impingement from asymptomatic individuals who had normal hips on examination. MR scans of 39 patients with groin pain, decreased internal rotation and a positive impingement test were compared with those of 35 asymptomatic control subjects. The waist of the femoral head-neck junction was identified on tilted axial MR scans passing through the centre of the head. The anterior margin of the waist of the femoral neck was defined and measured by an angle (alpha). In addition, the width of the femoral head-neck junction was measured at two sites. Repeated measurements showed good reproducibility among four observers. The angle alpha averaged 74.0 degrees for the patients and 42.0 degrees for the control group (p < 0.001). Significant differences were also found between the patient and control groups for the scaled width of the femoral neck at both sites. Using standardised MRI, the symptomatic hips of patients who have impingement have significantly less concavity at the femoral head-neck junction than do normal hips. This test may be of value in patients with loss of internal rotation for which a cause is not found. (+info)
Quantitative assessment of joint space width with an electronic caliper.
(67/715)
The progression of joint space narrowing (JSN) is considered to be the best available marker of osteoarthritis (OA) progression. Several techniques have been proposed for the measurement of joint space at its narrowest point in OA of the hips and knees. OBJECTIVE: To evaluate the properties of the technique using an electronic caliper for the measurement of JSN in OA patients. DESIGN: We used an electronic caliper to measure joint space width (JSW) for hips on 100 plain radiographs. JSW was measured in the vertical position at the center of the femoral head. Femoral head diameter was also determined to correct for variations due to differences in magnification of digitized X-rays. All films were read twice by each of two rheumatologists (one junior, one senior) and two radiologists (one junior, one senior). Intraclass correlation coefficients and their 95% confidence intervals were calculated. RESULTS: Detailed results are given for right hips (38 with OA, 18 inflammatory, 44 normal); very similar results were obtained for left hips. For JSW, the intraclass correlation coefficient was between 0.96 and 0.99 for intraobserver reliability. The level of reliability was similar for analysis of the diameter of the femoral head (R:0.84 to 0.98) and for the ratio of these two measurements (0.96 to 0.99). The most reliable measurements were those made by the senior radiologist, followed by those made by the two rheumatologists. In assessments of interobserver reliability for the measurement of JSW, R varied from 0.91 to 0.96 for the first reading and from 0.88 to 0.96 for the second reading. For the measurement of femoral head diameter, R varied from 0.86 to 0.96 for the first reading and from 0.74 to 0.96 for the second reading. CONCLUSION: The electronic caliper technique is an accurate method for measuring JSW in the hip. This technique seems to be reproducible, is simple, and could be used for routine evaluation. Further validation is required, with the measurement of serial X-rays from the same patients. (+info)
A biomechanical study on fixation stability with twin hook or lag screw in artificial cancellous bone.
(68/715)
The twin hook has been developed as an alternative to the conventional lag screw to be combined with a barrelled side-plate in the treatment of trochanteric hip fractures. With two oppositely directed apical hooks introduced into the subchondral bone of the femoral head, the twin hook provides different stabilising properties to the lag screw. The femoral head purchase of the twin hook and the lag screw were compared in a biomechanical study using artificial cancellous bone, and responses to axial and torsional loading was determined. A distinct yield point in load and torque was noted for the lag screw, representing failure of the laminas supporting the threads. For the twin hook, gradual increase of load and torque occurred during impaction of the bone supporting the hooks. The peak loads and torques were higher for the lag screw, but were similar for both devices after 8 mm deformation. The stiffness was higher for the lag screw, but in counter-clockwise rotation the stiffness for the lag screw was negligible. The twin hook appeared to provide fixation stability comparable to that offered by the lag screw, but with conceivable advantages in terms of a deformation response involving bone impaction and gradually increasing stability. (+info)
Ultrasound in the management of the position of the femoral head during treatment in a spica cast after reduction of hip dislocation in developmental dysplasia of the hip.
(69/715)
In this prospective study of 18 hips we compared the efficacy of ultrasound with CT in determining the position of the femoral head in a spica cast after closed or open reduction in children with developmental dysplasia of the hip. Ultrasound was performed through the perineal opening of the cast. With a transinguinal approach, the superior ramus of the pubis, the acetabulum, the femoral head and the femoral neck can be depicted in one plane. The CT and ultrasound images were blinded and reviewed by two of the authors. Ultrasound was inconclusive in the first two reductions since the perineal opening was too small to see all the landmarks in one plane. In the following 16 reductions the landmarks were well defined and interpretation of the CT and ultrasound was similar. The perineal opening in the spica cast should be made in such a way that the ultrasound probe can be positioned in the groin so that the landmarks can be shown in one plane. (+info)
Delayed ossification of the proximal capital femoral epiphysis in Legg-Calve-Perthes' disease.
(70/715)
We studied radiographs of 125 children (105 boys, 20 girls) with unilateral Legg-Calve-Perthes' disease to examine the epiphyseal development of the femoral head in the contralateral (unaffected) hip. The epiphyseal height (EH) and width (EW) of the unaffected hip were measured on the initial anteroposterior pelvic radiograph. In 109 of the patients (87.2%) the EH was below the mean for normal Japanese children and a significantly small EH (below -2 SDs) was observed in 23 patients (18.4%). By contrast, the EW of most patients (95.2%) lay within +/- 2 SDs of normal values except for six with a significantly small EW. A strong positive linear correlation (R = 0.87) was observed in the EH:EW ratio in the patients. A smaller EH than expected for EW in our series indicated epiphyseal flattening of the femoral head in Legg-Calve-Perthes' disease. Our findings support the hypothesis that a delay in endochondral ossification in the proximal capital femoral epiphysis may be associated with the onset of Perthes' disease. (+info)
Topographic and zonal distribution of tenascin in human articular cartilage from femoral heads: normal versus mild and severe osteoarthritis.
(71/715)
OBJECTIVE: The extracellular matrix glycoprotein tenascin (TN) is upregulated in articular cartilage with severe osteoarthritis (OA). This study gives a detailed description of TN expression in areas of articular cartilage from femoral heads with mild OA showing structural lesions and in structurally normal areas of the same femoral heads compared with normal cartilage and cartilage with severe OA. METHODS: Immunohistochemical evaluation was performed on cryosections stained with antibodies against TN. Sections were selected as follows: from each macroscopically normal femoral head (n=6) a normal central and peripheral biopsy; from each femoral head with macroscopically mild OA (n=8) a central biopsy that showed structural lesions and a peripheral normal biopsy; from each femoral head with severe OA (n=9) a central and a peripheral biopsy with structural lesions. Central biopsies represent load bearing areas, whereas peripheral biopsies are non-load bearing. RESULTS: Central cartilage with mild OA contains significantly higher levels of TN in the superficial zone than structurally normal, peripheral cartilage from the same femoral heads. Normal cartilage and cartilage with severe OA do not display this topographic variation. Central cartilage with mild OA shows significantly higher levels of TN than normal, central cartilage. Peripheral, normal cartilage with mild OA shows significantly less TN than peripheral cartilage with severe OA. CONCLUSIONS: In femoral heads with mild OA, TN is accumulated in areas displaying structural damage. This proposes mild OA to be a localized disorder. Extreme caution is necessary for sampling of articular cartilage, especially from joints with mild OA. (+info)
Asymptomatic avascular necrosis in patients with primary antiphospholipid syndrome in the absence of corticosteroid use: a prospective study by magnetic resonance imaging.
(72/715)
OBJECTIVE: To evaluate the prevalence of avascular necrosis (AVN), using magnetic resonance imaging (MRI), in patients with primary antiphospholipid syndrome (APS) and in patients with systemic lupus erythematosus (SLE), with or without anticardiolipin antibodies (aCL), who are asymptomatic for AVN and have not taken corticosteroids. METHODS: Seventy-nine subjects who were asymptomatic for AVN were evaluated by MRI of the femoral heads: 30 patients with primary APS who had never received corticosteroids, 19 SLE patients who had never received steroids (divided into 2 groups, aCL positive and aCL negative, in order to examine any association between AVN and aCL), and 30 healthy subjects who were age- and sex-matched with patients with primary APS. Established MRI criteria were used for a diagnosis of AVN. RESULTS: Asymptomatic AVN was evident in 6 (20%) of 30 patients with primary APS: 3 of them (1 man, 2 women) had intermediate bilateral AVN, and 3 (all women) had early AVN (bilateral in 1 patient). Results of hip and pelvis radiography and dynamic scintigraphy were negative. Followup MRI 6 months later revealed no changes. At the time of the initial MRI examination, the mean (+/-SD) age of patients in whom AVN was identified was 31.2 +/- 7.3 years, and that of patients without AVN was 42.4 +/- 11.9 years (P = 0.036). Livedo reticularis occurred significantly more commonly in the group with AVN (P = 0.041). None of the healthy subjects and none of the patients with SLE demonstrated AVN on MRI. CONCLUSION: AVN can be detected by MRI in 20% of patients with primary APS. Younger patients tend to develop AVN more frequently than do older patients, and the presence of livedo reticularis may identify individuals at risk for AVN. Clinicians should be aware of this possible clinical manifestation of primary APS, because early diagnosis can lead to early intervention. (+info)