Sacralization of L5 in radiological studies of degenerative spondylolisthesis at L4-L5.
METHODS
Radiological analysis.


OBJECTIVE
To investigate sacralization of L5 on radiological studies of degenerative spondylolisthesis at L4-L5.


BACKGROUND
Degenerative spondylolisthesis commonly develops at L4-L5. Sacralization of L5 is thought to cause stress concentration at this level, which accentuates degenerative changes and promotes development of degenerative spondylolisthesis. However, there has been no study dedicated to determining whether the presence of sacralization at L5 influences the radiological findings in degenerative spondylolisthesis at L4-L5.


METHODS
Seventy-eight patients with degenerative spondylolisthesis at L4-L5 were classified into two groups according to the presence of L5 sacralization: with (n=54) and without (n=24). Four radiographic parameters were measured and compared between the two groups: anterior slippage of L4 on L5 (% slip), facet orientation of L4-L5 (degrees), facet osteoarthritis of L4-L5 by Fujiwara's criteria (1~4 grades), and disc degeneration of L4-L5 by Frymoyer's criteria (grades 1~5).


RESULTS
There was no significant difference in the degree of anterior slippage of L4 on L5 (17.02+/-6.21 versus 16.65+/-4.87, p=0.809), facet orientation (54.99+/-12.18 versus 56.23+/-4.35, p=0.642), facet osteoarthritis (3.43+/-0.59 versus 3.53+/-0.37, p=0.527), or disc degeneration (4.50+/-0.51 versus 4.35+/-0.61, p=0.340) between the two groups.


CONCLUSIONS
Our study shows that the influence of sacralization of L5 on radiological findings in degenerative spondylolisthesis at L4-L5 may be less significant than previously expected. Further studies in large patient groups are needed to clarify the role of L5 sacralization on the development of degenerative spondylolisthesis at L4-L5.
Kong
Chae-Gwan
CG
Department of Orthopedic Surgery, The Catholic University of Korea College of Medicine, Seoul, Korea.
Park
Jong-Soo
JS
Park
Jong-Beom
JB
J Bone Joint Surg Br. 2001 Nov;83(8):1137-40
11764427
Spine (Phila Pa 1976). 1998 Aug 15;23(16):1785-92
9728379
J Spinal Disord. 1999 Feb;12(1):68-73
10078953
J Bone Joint Surg Am. 1975 Jun;57(4):467-74
1141255
Int Orthop. 1997;21(5):337-42
9476166
Eur Spine J. 1999;8(5):396-401
10552323
Scand J Rehabil Med. 1978;10(3):135-45
151915
Rheumatol Rehabil. 1977 Aug;16(3):180-5
143714
Spine (Phila Pa 1976). 1989 Dec;14(12):1373-7
2533403
Spine (Phila Pa 1976). 1981 Mar-Apr;6(2):168-71
7280817
J Bone Joint Surg Br. 1976 May;58(2):184-92
932080
Spine (Phila Pa 1976). 1984 Sep;9(6):574-81
6495027
Spine (Phila Pa 1976). 1984 Jul-Aug;9(5):493-5
6495013