Aims.
There is evidence that various anatomical structures have altered morphology with ageing, and anecdotal evidence of changing lumbar spinous process (LSP) morphology with age. This study aims to clarify the influence of age on LSP morphology, and on lumbar spine alignment. 200 CT scans of the abdomen were reformatted with bone windows allowing precise measurement of LSP dimensions and lumbar lordosis. Observers were blinded to patient demographics. Inter-observer reliability was confirmed. The smallest LSP is at L5. The male LSP is on average 2-3mm higher and 1mm wider than the female LSP. LSP height increases significantly with age at every level in the lumbar spine (P<10. -5. at L2). The LSPs increase in height by 2-5mm between 20-85 years of age (P<10. -6. ), which was as much as 31% at L5 (P<10. -8. ). Width increases proportionally more, by 3-4mm or greater than 50% at each lumbar level (P<10. -11. ). Lumbar lordosis decreases in relation to increasing LSP height (P<10. -4. ) but is independent of increasing LSP width (P=0.2). The height and width of the spinous processes increases with age. Increases in spinous process height are related to a loss of lumbar lordosis and may contribute to
Background: The Lumbar Spinous Processes (LSP) have an important anatomical and biomechanical function. They also influence access to the spinal canal for neural decompressive surgical procedures. There is evidence that various anatomical structures have altered morphology with ageing, and there is anecdotal evidence of changing LSP morphology with age. This study aims to clarify the influence of age on LSP morphology, and on lumbar spine alignment. Method: 200 CT scans of the abdomen were reformatted with bone windows allowing precise measurement of LSP dimensions, and Lumbar Lordosis. Observers were blinded to patient demographics. Inter-observer reliability was confirmed. Results: The smallest LSP is at L5. The male LSP is on average 2–3mm higher and 1mm wider than the female LSP. LSP height increases significantly with age at every level in the lumbar spine (P<
10-5 at L2). The LSPs increase in height by 2–5mm between 20–85 years of age (P<
10-6), which was as much as 31% at L5 (P<
10-8). Width increases proportionally more, by 3–4mm or greater than 50% at each lumbar level (P<
10-11). Lumbar lordosis decreases in relation to increasing LSP height (P<
10-4) but is independent of increasing LSP width (P=0.2). Conclusions: The height and width of the spinous processes increases with age. Increases in spinous process height are related to a loss of lumbar lordosis and may contribute to
Purpose: To document clinical and radiographic outcome, and survivorship of long fusion constructs (>
T12) stopping at L5. Methods: Retrospective clinical and radiographic analysis of long fusions to L5 in an adult population, with follow-up greater than 5 years. Results: We reviewed a consecutive series of patients with long fusion constructs ending at L5 from 1991–2000. 33 patients were identified with fusions from the thoracic spine to L5. 14 patients were excluded, including 7 deaths, 3 patients lost to follow-up, and 4 patients with incomplete radiographic and clinical data sets. There were 17 females and 2 males, with average age of 50 (range 25–73). 7 patients have since undergone extension of fusion to the sacrum, and comprised Group II; the remaining 13 patients comprised Group I. There was no association between preoperative radiographic characteristics of the deformity and outcome (coronal/
Malorientation of the acetabular cup in Total Hip replacement (THR) may contribute to premature failure of the joint through instability (impingement, subluxation or dislocation), runaway wear in metal-metal bearings when the edge of the contact patch encroaches on the edge of the bearing surface, squeaking of ceramic-ceramic bearings and excess wear of polyethylene bearing surfaces leading to osteolysis. However as component malorientation often only occurs in functional positions it has been difficult to demonstrate and often is unremarkable on standard (usually supine) pelvic radiographs. The effects of spinal pathology as well as hip pathology can cause large rotations of the pelvis in the sagittal plane, again usually not recognized on standard pelvic views. While Posterior pelvic rotation with sitting increases the functional arc of the hip and is protective of a THR in regards to both edge loading and risk of dislocation, conversely Anterior rotation with sitting is potentially hazardous. We developed a protocol using three functional positions – standing, supine and flexed seated (posture at “seat-off” from a standard chair). Lateral radiographs were used to define the pelvic tilt in the standing and flexed seated positions. Pelvic tilt was defined as the angle between a vertical reference line and the anterior pelvic plane. Supine pelvic tilt was measured from computed tomography. Proprietary software (Optimized Ortho, Sydney) based on Rigid Body Dynamics then modelled the patients’ dynamics through their functional range producing a patient-specific simulation which also calculates the magnitude and direction of the dynamic force at the hip and traces the contact area between prosthetic head/liner onto a polar plot of the articulating surface. Given prosthesis specific information edge-loading can then be predicted based on the measured distance of the edge of the contact patch to the edge of the acetabular bearing. Results and conclusions. The position of the pelvis in the sagittal plane changes significantly between functional activities. The extent of change is specific to each patient. Spinal pathology can be an insidious “driver” of pelvic rotation, in some cases causing
The objectives of this study were to assess the effect of anterior cruciate ligament (ACL) resection on flexion-extension gaps, mediolateral soft tissue laxity, maximum knee extension, and limb alignment during primary total knee arthroplasty (TKA). This prospective study included 140 patients with symptomatic knee osteoarthritis undergoing primary robotic-arm assisted TKA. All operative procedures were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess study outcomes pre- and post-ACL resection with knee extension and 90° knee flexion. This study included 76 males (54.3%) and 64 females (45.7%) with a mean age of 64.1 years (SD 6.8) at time of surgery. Mean preoperative hip-knee-ankle deformity was 6.1° varus (SD 4.6° varus).Aims
Methods
The interaction between the lumbosacral spine
and the pelvis is dynamically related to positional change, and
may be complicated by co-existing pathology. This review summarises
the current literature examining the effect of sagittal spinal deformity
on pelvic and acetabular orientation during total hip arthroplasty
(THA) and provides recommendations to aid in placement of the acetabular
component for patients with co-existing spinal pathology or long
spinal fusions. Pre-operatively, patients can be divided into four
categories based on the flexibility and sagittal balance of the
spine. Using this information as a guide, placement of the acetabular
component can be optimal based on the type and significance of co-existing
spinal deformity. Cite this article: