BAASTRUP SYNDROMEDr. Muhammad Bin ZulfiqarPGR IV FCPS Services Institute of Medical Sciences / Hospitalradiombz@gmail.com

BAASTRUP SYNDROME• Baastrup syndrome (also referred to as kissing spines) results

from adjacent spinous processes in the lumbar spine rubbing against each other and resulting in hypertrophy and sclerosis with focal midline pain and tenderness relieved by flexion and aggravated by extension.• Often occurs in elderly.• Focal midline pain and tenderness relieved by flexion and aggravated by extension.

PATHOLOGY

• This process can result in a degenerative hypertrophy, inflammatory change and even a pseudoarthrosis with bursa formation. This interspinous bursa may extend between the ligamentum flavae in the midline forming an epidural cyst and further contributing to the already existing canal stenosis.• This condition is usually seen patients with excessive

lordosis of the lumbar spine.

ASSOCIATIONS• Older age

• Anterolisthesis 

• Central canal stenosis

IMAGING LINEAGE• Plain radiograph

• CT scan

• MRI

• PET CT

PLAIN RADIOGRAPH• Often shows close approximation and contact of adjacent spinous processes (kissing spines) 

• There is resultant enlargement, flattening and reactive sclerosis of apposing interspinous surfaces

• Close approximation and contact of adjacent spinous processes (kissing spines) • There is resultant

enlargement, flattening and reactive sclerosis of apposing interspinous surfaces.• Anterior marginal kissing

osteophytosis.

CT SCAN• Often shows close approximation and contact of adjacent

spinous processes (kissing spines) 

• There is resultant enlargement, flattening and reactive sclerosis of apposing interspinous surfaces

• Spondylosis, osteochondrosis and degenerative intervertebral joint disease of the lumbar spine with massive disc space narrowing at L3/4/5 and their spinous processes L2-5 rubbing against each other. Osteophytes have formed at the contacting surfaces and there is a large geode at the base of the L3 spinous process indicating osteoarthritis in a nearthrosis.

MRI• May demonstrate interspinous bursal fluid and a postero-central epidural cyst(s). • MRI can be very helpful in determining whether there is resulting posterior compression of the thecal sac. 

• T1, T2, STIR and T1 Postcontrast • Baastrup syndrome with marked enhancement

• Baastrup syndrome, with high T2 signal between the rubbing spinous processes.

• Baastrup's disease T2 sagittal MR. Note spondylolisthesis at L4-L5 level with anterior and posterior disc herniations. Note also inter-spinous bursal fluid collection at same level.

• Baastrup's disease T2 WI. Arrow points to inter-spinous bursal fluid collection.

FDG-PET/CT

• May demonstrate FDG-avidity when associated with inflammatory response such as bursitis . Best diagnostic clue for avoiding misinterpretation may be scrutinizing sagittal multi planar reconstructions (MPR) and involvement being limited to spinous processes which is rare in malignancy . 

• Sagittal fused images reveal increased uptake in the spine, with involvement being limited to spinous processes, which is rare in malignancy.• Kissing spines confirmed by MPR of SOA CT.

MANAGEMENT• Local steroid injection into the interspinous processes will often ease the back pain.

• Surgical options include interspinous process decompression devices (e.g. Wallis system, X STOP), and steroid/local anesthetic injection into the bursa.

• X-Stop - post op• But 2 months later symptoms recurred because of displacement of X stop.

THANX