Traditionally recognized factors, such as age and biomechanics (abnormal physical loading), may play a role in the manifestation of intervertebral disk degeneration, according to researchers in the department of orthopaedics & traumatology at the University of Hong Kong. However, additional factors also may contribute.
Cheung and colleagues1 studied the prevalence of and risk factors associated with a unique pattern of disk degeneration of the lumbar spine, “skipped” level (nonconsecutive) disk degeneration (SLDD). To do so, they performed a cross-sectional analysis of participants in a large genetic-based study with disk degeneration of more than 2 levels, who were placed in SLDD and non-SLDD groups. Various radiographic parameters were evaluated on the basis of T2-weighted MRI; demographics also were assessed.
SLDD was present in 8.7% and 20.8% of the overall and multilevel disk degeneration populations, respectively; it was more prevalent in men. The condition was significantly associated with the presence of Schmorl nodes, also seen in levels with no disk degeneration. Disk bulge and extrusion and history of back injury were significantly associated with non-SLDD; a greater degree of overall disk degeneration severity also was associated with non-SLDD.
The authors noted that their study may be the first to describe the prevalence of SLDD and risk factors associated with it and that the additional factors warrant further investigation.
