Fredrickson BE, Baker D, et al. "The Natural History of Spondylolysis and Spondylolisthesis." 1984 - J Bone Joint Surg Am.; 66(5):699-707.

Beutler WJ, Fredrickson BE, et al. “The Natural History of Spondylolysis and Spondylolisthesis: 45-Year Follow-up Evaluation.” 2003 Spine; 28(10): 1027-1035.

In 2003, Beutler and Fredrickson published the results of the ONLY prospective investigation into the natural history of spondylolisthesis / spondylolysis (“spondylo”) after monitoring 30 afflicted volunteers for more than 45 years! After the last of many follow-up evaluations, the researchers concluded that spondylo is not associated with future chronic pain, impairment or disability. More explicitly, at the 45 year mark, all categories of the volunteers’ completed SF-36 testing (the number one physical impairment and mental health assessment form) was nearly identical to that of the normal population for the same age group. These findings lead the authors concluded that “the current study demonstrated that a unilateral pars defect is not associated with further slip or disability,” and “subjects with a bilateral pars defect follow a clinical course similar to that of the general population.”

THE STUDY:

In the mid 1950’s, 500 first grade New York students were x-rayed in order to assess the prevalence (occurrence rate) of Spondylolisthesis and/or Spondylosis. Initially, 22 children were affected with spondylo. The 500 students were followed and by age 18, an additional 6 spondylos occurred. Two more were discovered in the now adults by the mid twenties. Noteworthy is the fact that only one 16 year old girl developed low back pain, which was cured with conservative care but relapsed when she was 28.

RESULTS:

The bottom line was this: “Bilateral pars defects will develop symptomatic progression in only a small percentage of subjects in a long-term follow-up study,” and “there was no significant difference in the pain or physical functioning scores between the subject group [spondylo people] as a whole or those with a slip and the SF-36 norms [the general population age matched].” “No subject [in this study] ever filed a disability claim related to low back pain.”

At the 1988 re-examination and assessment 100% were available.

At the 1999 re-examination and assessment, 87% were available. (3 died and 1 refused to participate.) After MRI, re-x-ray, and the completion of a pain/disability assessment tool (SF-36), the researchers offered the forthcoming results:

10% of the group demonstrated complete healing of the spondylo. (This phenomenon was only seen in unilateral pars defects.)

Unilateral defect : (8 affected)

2 of 8 had moderate pain on the SF-36.

2 of 8 had DDD

1 of 8 had undergone discectomy one level above the L5 spondylo.

Bilateral defect : (22 affected)

18 of the 22 (82%) eventually developed slippage (spondylolisthesis). Nobody healed. Average slip increased from 11% to 18% over 40+ years (not much). 39% slip was the largest in this group.

2 of 22 underwent adult lumbar spinal sugery.

13 of 22 developed “segmental laxity.” (which was not defined.)

MRI Findings :

In 1999, of the remaining 26 spondylo people, 21 agreed to undergo MRI testing: 19 of the 21 had at least “some disc degeneration at some level.” (only two unilateral defect people were DDD free.) “A slip exceeding 15% always was associated with moderate or severe degeneration of the lumbosacral [L5] disc. Only two disc herniations were noted.

Disc Surgery :

3 of the 30 underwent lumbar spine surgery (2 discectomies and a fusion).

Pain:

During childhood and adolescents, only 1 spondylo person (16 year old female) suffered back pain.

By 1988 (about 30 years later), 12/30 (40%) had no pain to report. 11 reported mild intermittent low back pain, and 1 reported moderate low back pain. 0/30 reported having severe lower back pain.

In 1999 (about 40 years later), 26 of the 30 completed a standard SF-36 questionnaire. “For each of the functional and pain indexes, there was no significant difference between the subject population and the SF-36 Health Manual Survey for subjects 45 to 55 years of age.” “There was no significant difference in the pain or physical functioning scores between the subject group as a whole or those with a slip and the SF-36 norms.” “No subject ever filed a disability claim related to low back pain.”

8 of 26 (31%) reported only one day of lost work over their life time secondary to low back pain.

3 of 26 (12%) reported the use of analgesic medication over their life time.

“By the fifth decade, the authors noted seven subjects [7/26 (27%)] with a score of lower than 50 (moderate pain) on the SF-36 pain assessment.”

“There was no significant difference in the SF-36 scores for unilateral or bilateral pars defects and the norms for the general population.” The onset of slip, whether in childhood or adolescence, did not occur with pain in those years, nor was it associated with pain in adulthood.”

Although there is a relationship between slip progression and disc degeneration.

The authors criticize other authors for only studying symptomatic spondylo patients.