The aim of this study was to compare the peak pull-out force
(PPF) of pedicle-lengthening screws (PLS) and traditional pedicle
screws (TPS) using instant and cyclic fatigue testing. A total of 60 lumbar vertebrae were divided into six groups:
PLS submitted to instant pull-out and fatigue-resistance testing
(groups A1 and A2, respectively), TPS submitted to instant pull-out
and fatigue-resistance testing (groups B1 and B2, respectively)
and PLS augmented with 2 ml polymethylmethacrylate, submitted to
instant pull-out and fatigue-resistance testing (groups C1 and C2,
respectively). The PPF and normalized PPF (PPFn) for bone mineral density
(BMD) were compared within and between all groups.Aims
Materials and Methods
The aims of our study were to provide long-term information on
the behaviour of the thoracolumbar/lumbar (TL/L) curve after thoracic
anterior correction and fusion (ASF) and to determine the impact
of ASF on pulmonary function. A total of 41 patients (four males, 37 females) with main thoracic
(MT) adolescent idiopathic scoliosis (AIS) treated with ASF were
included. Mean age at surgery was 15.2 years (11 to 27). Mean follow-up
period was 13.5 years (10 to 18).Aims
Patients and Methods
This short contribution aims to explain how intervertebral disc ‘degeneration’ differs from normal ageing, and to suggest how mechanical loading and constitutional factors interact to cause disc degeneration and prolapse. We suggest that disagreement on these matters in medico-legal practice often arises from a misunderstanding of the nature of ‘soft-tissue injuries’.
