Introduction:. Shoulder balance after surgery is one main attribute of the cosmetic outcome. It has been difficult to assess on 2D images. The balance results from the interaction of rib cage, shoulder joint and scapular positions, spinal alignment and rotation, muscle size and co-ordination and pain interaction. Attempts have been made to predict shoulder balance from radiograph measurements. There is no consensus on this. Attempt:. To assess whether T1 tilt has any relation to final shoulder balance after surgery. Method:. Retrospective review of radiographs of adolescent idiopathic scoliosis patients from 2009 to 2012. 61 identified with average age of 17 and follow up of 24 months. T1 tilt is measured pre-op, immediately post-op and at the latest follow up. Radiographic shoulder balance based on soft tissue shadow is assessed at the same interval. The balance is based on eyeballed perception, which is what patients do normally. Results:. The average T1 tilt is 3.6° pre-op (−11° to 12°), changing to −2.4° (−14° to 8.2°) immediately post op and to −3.5° (−9.3° to 0.7°) at the latest follow up. The proportion of balanced shoulder improved from 14% pre-op to 14% immediately post op and to 65% at final follow up. No relation of pre-op T1 tilt and the final shoulder balance can be found. Discussion:. Shoulder balance is a dynamic feature. Patients can regain shoulder balance given time. We cannot tell whether this is due to their adaptive process or rotational movement of the spinal construct over time here. Conflict Of Interest Statement: No conflict of interest

This prospective multicentre study was undertaken to determine segmental movement, disc height and sagittal alignment after total disc replacement (TDR) in the lumbosacral spine and to assess the correlation of biomechanical properties to clinical outcomes.

A total of 173 patients with degenerative disc disease and low back pain for more than one year were randomised to receive either TDR or multidisciplinary rehabilitation (MDR). Segmental movement in the sagittal plane and disc height were measured using distortion compensated roentgen analysis (DCRA) comparing radiographs in active flexion and extension. Correlation analysis between the range of movement or disc height and patient-reported outcomes was performed in both groups. After two years, no significant change in movement in the sagittal plane was found in segments with TDR or between the two treatment groups. It remained the same or increased slightly in untreated segments in the TDR group and in this group there was a significant increase in disc height in the operated segments. There was no correlation between segmental movement or disc height and patient-reported outcomes in either group.

In this study, insertion of an intervertebral disc prosthesis TDR did not increase movement in the sagittal plane and segmental movement did not correlate with patient-reported outcomes. This suggests that in the lumbar spine the movement preserving properties of TDR are not major determinants of clinical outcomes.

Cite this article: Bone Joint J 2013;95-B:81–9.

We examined the reliability of radiological findings in predicting segmental instability in 112 patients (56 men, 56 women) with a mean age of 66.5 years (27 to 84) who had degenerative disease of the lumbar spine. They underwent intra-operative biomechanical evaluation using a new measurement system. Biomechanical instability was defined as a segment with a neutral zone > 2 mm/N. Risk factor analysis to predict instability was performed on radiographs (range of segmental movement, disc height), MRI (Thompson grade, Modic type), and on the axial CT appearance of the facet (type, opening, vacuum and the presence of osteophytes, subchondral erosion, cysts and sclerosis) using multivariate logistic regression analysis with a forward stepwise procedure. The facet type was classified as sagittally orientated, coronally orientated, anisotropic or wrapped.

Stepwise multivariate regression analysis revealed that facet opening was the strongest predictor for instability (odds ratio 5.022, p = 0.009) followed by spondylolisthesis, MRI grade and subchondral sclerosis. Forward stepwise multivariate logistic regression indicated that spondylolisthesis, MRI grade, facet opening and subchondral sclerosis of the facet were risk factors. Symptoms evaluated by the Short-Form 36 and visual analogue scale showed that patients with an unstable segment were in significantly more pain than those without. Furthermore, the surgical procedures determined using the intra-operative measurement system were effective, suggesting that segmental instability influences the symptoms of lumbar degenerative disease.