We evaluated the percentage of patients with acetabular labral tears who have a structural hip abnormality detectable by conventional radiography. Records from our institution from 1996 through 2002 were reviewed to identify all patients with labral tears. Patients were excluded who had classic hip dysplasia, advanced osteoarthritis, or a history of pelvic or femoral osteotomy. The hip radiographs were evaluated for abnormalities of Tonnis angle, center-edge angle of Wiberg, acetabular version, femoral neck-shaft angle, congruency between the femoral head and acetabulum, anterior femoral head-neck offset, and presence of femoral head osteophytes. Twenty-seven of the 31 patients (87%) had at least one abnormal finding and 35% had more than one abnormality. Ten patients had a retroverted acetabulum, 16 had coxa valga, 11 had an abnormal femoral head-neck offset, and 14 had osteophytes on the femoral head. Four of 31 patients (13%) had no identifiable structural abnormalities. To our knowledge, this is the first study to document that the majority of patients with labral tears have a structural hip abnormality detectable with conventional radiographs. Familiarity with these structural abnormalities is important for early detection and accurate diagnosis, and may impact optimal treatment planning and prognosis.

Acetabular labral tears rarely occur in the absence of bony abnormalities.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(98)01302-6.pdf

Natural history of scoliosis in spastic cerebral palsy

Purpose The purpose of this study was to describe the MR appearance of the acetabular labrum in asymptomatic hips on high resolution MRI. Method Fifty-two hips in 46 asymptomatic volunteers with an age range of 15-85 years were evaluated with coronal and axial T1-weighted and T2-weighted sequences. The shape, margin, size, and signal intensity of the acetabular labrum were analyzed. Results The labrum was absent in its anterosuperior aspect in five hips (10%). Intralabral regions of intermediate of high signal intensity were detected in 30 hips (58%) imaged with T1-weighted and proton density-weighted sequences. Intralabral linear hyperintense foci reaching the articular surface and consistent with a labral tear were detected in four labra on T2-weighted images. Intralabral microcysts were seen in three labra. Conclusion The MR appearance of the hip labrum is varied in asymptomatic volunteers. Intralabral increased signal intensity and absent anterosuperior labra are especially frequent and may represent asymptomatic lesions or normal variations.

Acetabular labrum: MRI in asymptomatic volunteers.

Purpose: To evaluate the sensitivity and accuracy of magnetic resonance arthrography (MRA) with true sagittal scout image mapped radial reformation in localizing hip labral tears. Type of Study: Case series. Methods: Thirty patients were examined with hip MRA because of suspected labral tears. Every patient underwent normal hip arthrography and MR examinations using a 1.5-T scanner with a 3D-FLASH pulse sequence. Multiplanar reformation using double oblique technique produced radial reformatted rotation images with 10° increment on the acetabular rim. Labral tears were annotated as anterior-superior (AS), anterior-inferior (AI), posterior-superior (PS), and posterior-inferior (PI) quadrant based on the cranial-caudal axis in true sagittal reformatted scout localizing image. Patients with positive MRA findings were counseled to have the arthroscopic hip procedure. Results: Five patients showed no MRA indication of labral tear. Of 25 patients who had MRA evidence of labral tear, 17 underwent arthroscopic hip surgery. One patient had only synovial process in the hip joint near the suspected MRA area. The remaining 16 operated patients had labral tears with a total of 21 quadrant lesions on arthroscopy (distributed as AS, 14; AI, 3; PS, 2; and PI, 2). Radial reformatted images revealed accurate mapping with arthroscopic findings in 21 of the 22 quadrant lesions. The sensitivity and accuracy of MRA for the diagnosis of hip labral tear were 100% and 94%, respectively, and the sensitivity and accuracy of radial reformatted MRA for mapping the tear location were 100% and 96%, respectively. Conclusions: MRA using radial reformatted images with a true sagittal localizer may achieve superior success rates in diagnosing hip labral lesions and in guiding the arthroscopist in portal selection, thus rendering location of hip labral tears simpler in surgery. It supplied detailed preoperative information to the surgeon, avoiding unnecessary surgery for patients if the diagnosis was unconfirmed. Level of Evidence: Level III.

Evaluating hip labral tears using magnetic resonance arthrography: a prospective study comparing hip arthroscopy and magnetic resonance arthrography diagnosis.

Osteogenesis Imperfecta (OI) is a human syndrome characterized by exquisitely fragile bones due to osteoporosis. The majority of autosomal dominant OI cases result from point or splice site mutations in the type I collagen genes, which are thought to lead to aberrant osteoid within developing bones. OI also occurs in humans with homozygous mutations in Prolyl-3-Hydroxylase-1 (LEPRE1). Although P3H1 is known to hydroxylate a single residue (pro-986) in type I collagen chains, it is unclear how this modification acts to facilitate collagen fibril formation. P3H1 exists in a complex with CRTAP and the peptidyl-prolyl isomerase cyclophilin B (CypB), encoded by the Ppib gene. Mutations in CRTAP cause OI in mice and humans, through an unknown mechanism, while the role of CypB in this complex has been a complete mystery. To study the role of mammalian CypB, we generated mice lacking this protein. Early in life, Ppib-/- mice developed kyphosis and severe osteoporosis. Collagen fibrils in Ppib-/- mice had abnormal morphology, further consistent with an OI phenotype. In vitro studies revealed that in CypB–deficient fibroblasts, procollagen did not localize properly to the golgi. We found that levels of P3H1 were substantially reduced in Ppib-/- cells, while CRTAP was unaffected by loss of CypB. Conversely, knockdown of either P3H1 or CRTAP did not affect cellular levels of CypB, but prevented its interaction with collagen in vitro. Furthermore, knockdown of CRTAP also caused depletion of cellular P3H1. Consistent with these changes, post translational prolyl-3-hydroxylation of type I collagen by P3H1 was essentially absent in CypB–deficient cells and tissues from CypB–knockout mice. These data provide significant new mechanistic insight into the pathophysiology of OI and reveal how the members of the P3H1/CRTAP/CypB complex interact to direct proper formation of collagen and bone.

/pdf/severe-osteogenesis-imperfecta-in-cyclophilin-b-deficient-1d3enggs54.pdf

Severe osteogenesis imperfecta in cyclophilin B-deficient mice.

Arthroscopy of the hip joint was performed in 19 children with Legg-Calve-Perthes' disease. Proliferation of the synovium was pronounced both in the acetabular fossa and over the inner wall of the capsule. Hypervascularity was seen on the acetabular labrum in every stage of the disease. Microscopically, hyperplasia of the synovial lining cells was observed, but inflammatory changes in the synovial tissue were inconspicuous in the early stage of the disease. Although hypertrophy of the endothelial cells of the vessels was seen in the late stage of the disease, it was not distinct in the initial or fragmentation stages. Joint pain improved after irrigation during arthroscopy.

Arthroscopy in 19 children with Perthes' disease Pathologic changes of the synovium and the joint surface

The authors analyzed lateral deviation, anteroposterior deformity, and rotation of the spinal column of 11 patients with scoliosis associated with cerebral palsy (CP) and 11 patients with progressive muscular dystrophy (PMD). There was a correlation between the magnitude of Cobb angle and that of the vertebral rotation in scoliosis associated with both CP and PMD, but the ratio of spinal rotation to Cobb angle in the former was lower than that in the latter, The magnitudes of thoracic kyphosis and of lumbar lordosis were not correlated with Cobb angle in either group, but the sagittal plane deformity in the CP patients was less severe than that in the PMD patients, and the latter demonstrated kyphosis of the lumbar spine and lordosis of the thoracic spine.

Yoshihito Nishino

Papers

Arthroscopy in 19 children with Perthes' disease Pathologic changes of the synovium and the joint surface

Three-dimensional spinal deformity in scoliosis associated with cerebral palsy and with progressive muscular dystrophy.