Hip–spine relations and sagittal balance clinical consequences

Abstract

IntroductionThe role of the pelvic area in sagittal balance is evident for spinal surgeons, but the influence of the coxofemoral joint is underestimated and inadequately explained by conventional imagery. Comprehensive analysis of the pelvic and subpelvic sectors as part of the sagittal, frontal and cross-sectional balance of the trunk sheds new light on some spinal diseases and their relation to the pelvis.MethodsThis analysis, based on innovative radiologic methods as the EOS® technology but also on a new look at conventional imaging makes it possible to better analyze standing lateral images and seated images.ResultsDisturbances can come from atypical morphotypes or from unusual postures as in aging spine. The measurement of available extension and the concept of available flexion provide new information regarding individual’s adaptation to the imbalance induced by disorders of the spine or lower limbs.ConclusionA comprehensive assessment of each patient and in particular of the complex comprising the spine and the pelvis, is essential for understanding each individual’s adaptation to the imbalance induced by disorders of the spine or lower limbs.

Does Degenerative Lumbar Spine Disease Influence Femoroacetabular Flexion in Patients Undergoing Total Hip Arthroplasty?

“…2). ''Pelvic tilt'' can be measured on lateral views using various anatomic landmarks, including the anterior pelvic plane, the femoral head axis (for pelvic incidence), or the endplate of the sacrum [19,21]. For the purpose of this study, we used sacral slope angle (the angle between the endplate of the sacrum and the horizontal plane) as a surrogate for pelvic tilt in standing and sitting positions [19].…”

“…The etiology of hip instability is multifactorial and often has been associated with such surgical variables as operative approach, implant choice and position, and soft tissue repair [6,34]. However, more recently a topic of considerable discussion is dynamic sagittal pelvic tilt and its role in deciding the optimal position of the acetabular component to avoid instability [21,30]. Variability in pelvic tilt can change acetabular component orientation after THA, and hip replacement surgeons have investigated pelvic tilt in sitting posture [11,19,20], because posterior dislocations often occur when a patient is rising from a chair.…”

Editorial review: Equalisation of leg lengths in total hip arthroplasty for patients with Crowe type-IV developmental dysplasia of the hip

“…Furthermore, in Li's series spinal sagittal balance and its complex multifactorial relationship with the coronal plane has not been considered, nor the resultant effects that restoration of LLD may produce. The implication for acetabular component anteversion is well documented (9,11,12), and similar considerations with regard to the hip-spine relationship as addressed with the coronal plane, are merited in the sagittal plane. For complex reconstructive cases where significant correction of leg lengths will have an impact on the spine, we recommend a careful multidisciplinary approach with pre-operative planning performed by both hip and spinal specialists working in concert.…”

Sexual Dimorphism of Acetabular Anatomy Based on Three-dimensional Computed Tomography Images of Pelvises

“…Tylko obliczenia w oparciu o rzeczywiste modele trójwymiarowe pozwolą znacznie ograniczać błąd pomiaru. Normy dotyczące orientacji prze strzennej panewek nie są jednak wystarczająco określone i często opierają się o płaszczyzny, których dokładność wyznaczania jest niepewna [4][5][6][7][8]11,[20][21][22][23][24]. Równocześnie różnice w strukturze i ustawieniu panewek stawu biodrowego w zależności od płci, choć już opisywane, wymagają nadal uwierzytelnienia naukowego [5][6][7][8], co istotnie może wpłynąć na zrozumienie problemu klinicznego i pośrednio na jakość wykonywanych zabiegów ortopedycznych.…”

“…The measurement error may only be significantly reduced if calculations are based on actual three-dimensional models. However, the norms for spatial orientation of the acetabulum have not been determined sufficiently precisely and are based on planes the determination of which is of uncertain accuracy [4][5][6][7][8]11,[20][21][22][23][24]. At the same time, sex differences in the anatomy and orientation of the acetabulum, while already described, still require scientific evidence to be regarded as reliable [5][6][7][8], which may have a significant impact on the understanding of this clinical problem and, indirectly, on the quality of orthopaedic surgeries being performed.…”