Laminectomy v. Instability v. Outcomes

Padua R, et al. "Ten- to 15-year outcome of surgery for lumbar disc herniation:" Eur Spine J - 1999; 8:70-74.

One of the amazing things about this investigation was the fact that the authors were able to follow 80% of the cohort (group that got the disc surgery) for over 10 years! Another amazing finding was that only 50% of the patients found to have clinical instability--secondary to the surgery--were symptomatic.

In other words half of the patients with motion segment instability or pain free. This sheds doubt on the old adage that clinical lumbar instability always is associated with pain and needs to be surgically stabilized.

Another important feature put forth in this study protocol was that they not only employed the standard clinical objective outcome assessment tools, but they also included a patient satisfaction study result. This sort of "dual assessment" has been found to be extremely important when assessing clinical outcomes. [29]

This study investigated the clinical outcomes of 150 back and leg pain patients, all of whom underwent discectomy with either laminotomy or laminectomy.

The aims of the study were as follows: (1) assess the efficacy (how well the surgery worked) of "wide laminectomy" versus the less invasive discectomy with interlaminar fenestration and (2) to assess the post-operation rate of lumbar instability (the vertebra operated upon becomes "loose") following the disc surgery. Noteworthy was the fact the same surgeon performed all the operations and none of the patients were unstable before the surgery. (see results)

Patient Inclusion Criteria:  

•  Persistent sciatica for more than 6 weeks, with or without neurological findings, that had failed to respond to conservative treatment.

•  Clinically determined radiculopathy at the L4, L5, or S1 level.

•  Positive Imaging study for disc herniation, i.e., CT or Myelogram.

•  EMG for those cases that were unclear as to the level of the problem.

•  No prior lumbar surgery, tumor, fracture, infection, or deformity.

Pre-Operative Diagnoses:

The Clinical Outcome:

As noted above, 80% of the 150 patients were contacted between 10 and 15 years.   They all completed a modified version of the Roland-Morris disability questionnaire (four extra questions were added regarding continued lower extremity symptoms, satisfaction with the surgery, and whether or not a subsequent surgery (like fusion) was needed. Physical re-evaluation was performed on only 56% of these contacted patients. The other 43% refused the reevaluation because they were completely better and symptom free. New X-rays were performed on 41% of the physically re-evaluated patients to assess whether or not they had become instable secondary to the surgery. Perhaps surprisingly, 60% of the group had indeed become instable at at least one lumbar vertebral level. However, even more surprisingly, only 50% of the instable patients suffered back and/or leg pain! This was unexpected as it demonstrated that clinical instability does NOT always indicate a painful condition.

Results:

My question with these results is that how can 90% of the patients have NO lower limb pain, but only 77% were completely satisfied by their surgery?   I would guess that the dissatisfaction stems from limitations of function; i.e., can't lift heavy, can't play certain sports etc.   Another problem was noted: the satisfaction rates given in the discussion did not quite match the rates given in Table one, although they were similar. Of all the outcome studies, this has one of the highest patient satisfaction rates, although there are others that have similarly high patient satisfaction rates (31, 32). Even so, its still quite an impressive study.

I Wish They Would Have:

I wish they would have asked the patient who had a successful outcome (90%), how long it took for them to reach their peak improvement. For me, it took four year for me to become a "90% no pain on a typical day."

Reoperation's :  

Quite amazing was the fact that there were NO reoperation's after 12 years!   The author feels this is because the surgical technique used - standard laminectomy and occasional foraminotomy - allowed for the creation of a "wide space" around the affected nerve roots, and their path through the foramen.  

The authors defended his preferred treatment method (standard wide-laminectomy), which is notorious for creating post-surgical instability and premature degenerative change, by saying, "it is difficult to establish whether these phenomena [instability & degeneration] are due to the natural history of degenerative disease or a result of surgery." He also noted that radiographic instability is NOT always symptomatic (30).

Conclusion:

"We believe that the standard procedure (wide laminectomy & arthrectomy) for disc herniation is still a good treatment, given its safety and simplicity, unless there are elective indications for microinvasive techniques."   They also wisely note that the "indication for surgery" is "one of the most important steps for a good outcome" of disc herniation surgery.

References:

29) Johnson L, "Outcomes analysis in spinal research." Clin North Am - 1994; 25:205-213

30) Sato H, Kikuchi S, "The natural history of radiographic instability of the lumbar spine." Spine - 1993; 18:2075-2079

31) Jonsson B, (1993) Repeat decompression of lumbar nerve roots. J Bone Joint Surg (Br) 75: 894-897

32) Junge A, et al. (1995) Predictors of bad and good outcomes of lumbar disc surgery: Spine 20:460-468

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