The Study: Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis: A radiographic study
- The authors indicate that proper "sagittal spine-pelvis-lower extremity alignment is " needed for "ergonomic upright standing posture".
- The authors wished to see how severe knee osteoarthritis (KOA) could affect sagittal spine-pelvis-lower extremity alignment.
- "Chronic LBP is very common in patients with knee osteoarthritis (KOA), and this phenomenon has been termed 'knee-spine syndrome'."
- The reason for this associated low back pain has not been sufficiently investigated.
- Posteroanterior and lateral radiographs were taken in three sections.
- d. These were put together to make one posteroanterior and one lateral radiograph "including the whole spine, pelvis and femur.".
- There were two groups, one with a primary diagnosis of KOA and a group of "asymptomatic controls free from KOA".
- It is known that chronic low back pain is a risk factor for a poor outcome for patients who have total knee replacement.
- The authors concluded that the sagittal alignment of these subjects was in fact significantly affected by the presence of severe KOA.
- The authors cite prior research (Chaleat-Valayer et al) which indicated that "abnormal sagittal spinopelvic alignment has been found in patients suffering from chronic, LBP...".
- However the authors also note that in the present study the findings did not support the hypothesis that the sagittal alignment was associated with the low back pain for these patients suffering from KOA. But they also noted that the numbers in this study were small being only 59 subject with KOA and 58 in the control group.
In this study the knee osteoarthritis affected the sagittal alignment but the results of this study did not appear to support the idea that those changes in sagittal alignment were necessarily associated with the low back pain of those suffering from the KOA.
And this is why we do a lot of studies. One of the things that is interesting to me is that I sometimes hear on TV or in some other medium that a new study has shown X. The reporter then goes on to make some comment on how important this finding of X is to you the viewer or reader. The finding of X is in the new study, but perhaps other previous studies have shown something different. The new study could have gotten a different answer for many reasons. We try to report on many studies and this one indicated that KOA did affect sagittal alignment but did not appear to support the hypothesis that sagittal alignment was associated with the low back pain of severe KOA subjects.
Reviewer: Roger Coleman DC
Editor: Mark R. Payne DC
Reference: Wang WJ, Liu F, Zhu YW, Sun MH, Qiu Y, Wng WJ. Sagittal alignment of the spine-pelvis-lower extremity axis in patients with severe knee osteoarthritis: A radiographic study. Bone Joint Res. 2016;5:198-205.
Link to Abstract: https://www.ncbi.nlm.nih.gov/pubmed/27231331