Lumbosacral interspinous ligament rupture associated with acute intrinsic spinal muscle degeneration.
OBJECTIVE
To demonstrate lumbosacral interspinous ligament rupture, with or without related paraspinal muscle degeneration.


METHODS
This study consisted of a prospective imaging analysis of 100 consecutive MRI studies in adult patients (mean age: 56 years) presenting with low back pain. Alterations from the normal in the inter- and perispinal structures of the spine and perispinal soft tissues (e.g. spinal ligaments, perispinal muscles) were sought based upon studies on young volunteers without low back pain (n = 10; mean age: 23 years).


RESULTS
Compared to the group without low back pain, many index cases (n = 71: 71%) demonstrated hyperintensity (i.e., sprain or frank ligamentous rupture) of the interspinous ligament(s) on T2-weighted, fat suppressed MRI studies at one (n = 20/71:28%) or multiple (n = 51/71:72%) levels. Associated paraspinal muscle (e.g., interspinalis, multifidus muscles) degeneration was observed in a minority of cases overall (n = 7: 7%), but was only seen in association with cases also demonstrating interspinous ligament degeneration/rupture (n = 7/71:10%).


CONCLUSIONS
Lumbosacral interspinous ligament sprain or frank rupture, as well as related acute-subacute autotraumatic paraspinal muscle rupture/degeneration, may be overlooked by many observers if fat suppressed, T2-weighted MRI is not acquired. These musculoligamentous alterations are on occasion the only abnormalities recognized on MRI of the lumbosacral spine and may theoretically be sources of low back morbidity that potentially may respond to specific therapy. Because this study was an observational one, based solely upon medical imaging, future research must focus upon the correlation of the relevance of these findings with an age-matched asymptomatic control group and longitudinal clinicoradiologic therapeutic trials.
Jinkins
J Randy
JR
Medical College of Pennsylvania-Hahnemann, Drexel University, Philadelphia, Pennsylvania, USA.
D016022:Case-Control Studies; D006801:Humans; D008022:Ligaments / Q000473:pathology*; D017116:Low Back Pain / Q000209:etiology; D008161:Lumbosacral Region; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D012422:Rupture, Spontaneous / Q000473:pathology; D013122:Spinal Diseases / Q000473:pathology*