Baastrup syndrome, also known as kissing spines, occurs when adjacent spinous processes in the lumbar spine rub together, causing hypertrophy and sclerosis that results in midline back pain relieved by flexion and aggravated by extension. Imaging such as plain radiographs, CT scans, and MRI can show contact between spinous processes, enlargement and reactive changes. Management options include local steroid injections or surgical decompression devices.

1. BAASTRUP SYNDROME
Dr. Muhammad Bin Zulfiqar
PGR IV FCPS Services Institute of Medical Sciences / Hospital
radiombz@gmail.com

2. 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.

3. 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.

4. ASSOCIATIONS
• Older age
• Anterolisthesis
• Central canal stenosis

5. IMAGING LINEAGE
• Plain radiograph
• CT scan
• MRI
• PET CT

6. 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

7. • 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.

8. 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

9. • 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.

10. 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.

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

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

13. • 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.

14. 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 .

15. • 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.

16. 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.

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

18. THANX