Using data obtained by questionnaire in a retrospective review of
patients with low-back and sciatic pain (eighty-five treated by injection
of chymopapain and seventy-one, by open discectomy), the results at one and
ten years after treatment were analyzed. For this analysis we used six
measures of pain relief, six measures of the patients' course during the
ten-year period since primary treatment, and four measures of the patients'
history of employment or work since initial treatment. Validity studies
demonstrated that the pain-outcome measures reflected the patients'
condition adequately and that all six measures were significantly related
to each other (Pearson's r, p less than 0.003). The chymopapain and
discectomy groups were not distinguishable on the basis of the pain-outcome
measures. However, body mass was directly related to the presence of pain
ten years after discectomy but not after injection of chymopapain. Analysis
of the progress measures (indicators of the course of the patients' pain
during the ten-year period) showed that the rates of reoperation in the two
treatment groups did not differ significantly, but the discectomy patients
tended to have had a higher rate of reoperation at both one and ten years
after initial treatment. These measures did not show unequivocal
superiority of one treatment compared with the other. Using the work
measures (assessments of the patients' history of employment since initial
treatment), it was found that in both treatment groups the patients who
returned to work six to twelve weeks after treatment despite persistent
symptoms had significantly more pain at ten years (p less than 0.04). Also,
the patients who returned to work less than six weeks after treatment,
while still symptomatic, showed a similar trend. On the other hand, among
the patients who were still symptomatic at twelve weeks, it made no
difference in the final results whether they returned to work at twelve
weeks or thereafter. These findings support the notion that after either
discectomy or chemonucleolysis, patients should return to work only after
complete symptomatic recovery or a minimum convalescence of twelve
weeks.