Sagittal lumbo-pelvic alignment in the sitting position of elderly persons.

INTRODUCTION: In elderly persons, the sitting position in daily life is very important due to the weakness in locomotion. In previous studies, sagittal spinal alignment was mainly analyzed in the standing position. However, in order to study the sagittal spinal alignment of elderly persons, the estimation of spinal alignment in the sitting posture is also important. We proposed that there is a characteristic spinal alignment in elderly persons in the sitting position. The purpose of this study was to evaluate the sagittal lumbo-pelvic alignment in the standing and sitting positions in elderly persons. SUBJECTS & METHODS: This study included 73 young adult subjects (48 men and 25 women; age 34.4 ± 8.1 years) and 107 elderly subjects (65 men and 42 women; age 67.6 ± 8.3 years). The following radiographic parameters were determined by computer-assisted measurement: L1L5 angle (L1L5), lumbosacral angle (LSA), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI). RESULTS: L1L5 decreased and the pelvis rotated posteriorly in the sitting position in both young adults and elderly persons. However, the extent of alignment difference between standing and sitting in elderly persons was nearly half that of young adults (in particular, the lumbo-pelvic junction, LSA, was smaller). Regarding the extent of correlation between aging and lumbo-pelvic alignment parameters, there were significant correlations. In elderly persons, the correlation between L1L5 and PT had a tendency to be poor in the sitting position. CONCLUSION: The elderly in the sitting position showed greater lumbar lordosis and higher sacral slope than in young adults, and the correlations among lumbo-pelvic parameters were poorer than those of young adults. Thus, when moving from sitting to standing, the lumbo-pelvic mobility in the sagittal plane is suspected to be poor in elderly persons.

Clasped position for measurement of sagittal spinal alignment.

Lateral whole-spine radiography is a useful tool in the management of spinal deformity, but the most appropriate arm position during radiography has yet to be determined. In this prospective study, we evaluated 26 adult volunteers and 22 patients with lumbar spinal canal stenosis. Lateral whole-spine radiographs were acquired in the most stable and relaxed position while the subjects were standing with their arms extended and their hand gently clasped in front of the trunk (clasped position). The following parameters were measured: sagittal vertical axis (SVA), lumbar lordotic angle (LLA), pelvic angle (PA), pelvic lordosis angle (PRS1), pelvic tilt (PT), and pelvic incidence (PI). The reliability of measurements was assessed by interclass correlation coefficients. The SVA was slightly positive in volunteers. LLA, PA, PRS1, PT, and PI were compatible with standard normal values. The results showed "almost perfect agreement" with regard to intra- and interobserver reliability. The clasped position can be used effectively and reliably for measurement of sagittal spinal alignment for the lumbar region in adults.

Irreducible dislocation of the radial head with undisplaced olecranon fracture in a child: a case report.

Irreducible isolated dislocation of the radial head is a rare injury. In this study, we describe a patient with irreducible dislocation of the radial head associated with an undisplaced fracture of the olecranon. A 6-year-old girl fell down while walking and suffered injury to the posterior aspect of the proximal ulnar shaft with the right elbow in a slightly flexed position. Plain radiographs of the elbow revealed an anterior-medial dislocation of the radial head and an undisplaced fracture of the olecranon. However, the attempted closed reduction was not successful. An open reduction was then performed through a lateral approach. The radial head was found to be protruding through a buttonhole tear of the anterior joint capsule, causing the joint to become interposed between the articular surfaces of the joint, precluding closed reduction. Once the interposed capsule was extricated from the joint, the radial head could be easily reduced. At this point, no tear of the annular ligament was observed. Six months after the surgery, the patient was able to use her elbow fully and without pain. The range of motion was 0-140° for both extension and flexion and 90° for pronation and supination. Plain radiographs revealed a united bone of the olecranon and good reduction of the radial head. The radial head pushed through the tear of the anterior joint capsule. This buttonhole effect on the radial head prevented closed reduction of the radial head.