ABSTRACT
BDDH (borderline developmental dysplasia of the hip) or BHD (borderline hip dysplasia) is a disease with more controversies in the following aspects, including definition, diagnosis and interventions. The proportion of radiographic BDDH is 3.5 times that of developmental dysplasia of the hip (DDH) in the asymptomatic general population, and can exceed 40% in specific cohorts including female collegiate athletes. Up till now, researchers have not reached a consensus on its definition. The diagnosis depends largely on personal history, physical examinations and radiographic examination. The interventions, including non-operative approaches, hip arthroscopy and periacetabular osteotomy, are used. Inappropriate treatment may exacerbate symptoms and accelerate hip joint degeneration. Recent studies on BDDH with regard to its definition, diagnosis and interventions were reviewed. Lateral centre-edge angle (LCEA) measured on AP pelvis was crucial but not enough in defining BDDH, for it only reflects lateral coverage of the hip while anterior and posterior coverage may vary dramatically. Given that hips with an LCEA less than 20 degrees associated with developing osteoarthritis, we recommended that LCEA between 20 to 25 degrees be used as the radiographic criterion in the primary screening. Further evaluation of symptoms and physical examinations should be follow to identify hip instability and/or impingement. Periacetabular osteotomy must be indicated for hips with predominant instability and it can be performed with or without hip arthroscopy which is aimed to address labral lesion or cam deformity on the femoral side. Hip arthroscopy is indicated for hip with predominant impingement symptoms. However, there is no consensus on the outcomes of the two procedures currently. Further studies are still required to confirm long-term results. Thus, it is imperative to choose the right indications for each procedure.
ABSTRACT
Total hip arthroplasty (THA) is a well developed technique to which the spatial orientation of acetabular component is crucial.Since the idea of "safe zone" being proposed,such idea has long been obeyed by hip surgeons but has also been challenged in recent years.This is because post-operative instability could happen even if acetabular components are placed within "safe zone".The latest researches have demonstrated that sagittal spinal balance and spino-pelvic mobility can affect the spatial orientation of acetabular components.Factors including spinal degenerative changes,long lumbosacral changes and spinal ankyloses can lead to sagittal spinal imbalance and/or influence spino-pelvic mobility,which subsequently affect pelvic retroversion.Proper pelvic retroversion is a way to compensate for sagittal spinal imbalance and is beneficial to post-operative stability.It is necessary for hip surgeons to rethink "safe zone" before performing THA and understand spinal balance as well as spinopelvic mobility.The goal is to reduce the rate of dislocation.This review started by introducing the related spinopelvic parameters frequently seen in papers published recently and the definitions of acetabular cup orientations.After the spinal sagittal balance and its compensatory mechanisms session,discussed its clinical relevance,as well as the significance of spinal mobility,in spinopelvic motion under three different postures.
ABSTRACT
Total hip arthroplasty (THA) is a well developed technique to which the spatial orientation of acetabular component is crucial. Since the idea of "safe zone" being proposed, such idea has long been obeyed by hip surgeons but has also been challenged in recent years. This is because post-operative instability could happen even if acetabular components are placed within "safe zone" . The latest researches have demonstrated that sagittal spinal balance and spino-pelvic mobility can affect the spatial orientation of acetabular components. Factors including spinal degenerative changes, long lumbosacral changes and spinal ankyloses can lead to sagittal spinal imbalance and/or influence spino-pelvic mobility, which subsequently affect pelvic retroversion. Proper pelvic retroversion is a way to compensate for sagittal spinal imbalance and is beneficial to post-operative stability. It is necessary for hip surgeons to rethink "safe zone" before performing THA and understand spinal balance as well as spinopelvic mobility. The goal is to reduce the rate of dislocation. This review started by introducing the related spinopelvic parameters frequently seen in papers published recently and the definitions of acetabular cup orientations. After the spinal sagittal balance and its compensatory mechanisms session, discussed its clinical relevance, as well as the significance of spinal mobility, in spinopelvic motion under three different postures.