Prospective study of 100 lumbosacral discectomies

Predictors of Recovery Following Lumbar Microdiscectomy for Sciatica: A Systematic Review and Meta-Analysis of Observational Studies

Chronic post-surgical pain is reported by up to 40% of patients after lumbar microdiscectomy for sciatica, a complaint associated with disability and loss of productivity. We conducted a systematic review of observational studies to explore factors associated with persistent leg pain and impairments after microdiscectomy for sciatica. We searched eligible studies in MEDLINE, Embase, and CINAHL that explored, in an adjusted model, predictors of persistent leg pain, physical impairment, or failure to return to work after microdiscectomy for sciatica. When possible, we pooled estimates of association using random-effects models using the Grading of Recommendations Assessment, Development, and Evaluation approach. Moderate-certainty evidence showed that the female sex probably has a small association with persistent post-surgical leg pain (odds ratio (OR) = 1.15, 95% confidence interval (CI) = 0.63 to 2.08; absolute risk increase (ARI) = 1.8%, 95% CI = -4.7% to 11.3%), large association with failure to return to work (OR = 2.79, 95% CI = 1.27 to 6.17; ARI = 10.6%, 95% CI = 1.8% to 25.2%), and older age is probably associated with greater postoperative disability (β = 1.47 points on the 100-point Oswestry Disability Index for every 10-year increase from age (>/=18 years), 95% CI = -4.14 to 7.28). Among factors that were not possible to pool, two factors showed promise for future study, namely, legal representation and preoperative opioid use, which showed large associations with worse outcomes after surgery. The moderate-certainty evidence showed female sex is probably associated with persistent leg pain and failure to return to work and that older age is probably associated with greater post-surgical impairment after a microdiscectomy. Future research should explore the association between legal representation and preoperative opioid use with persistent pain and impairment after microdiscectomy for sciatica.

The Effect of Health Insurance Coverage on Orthopaedic Patient-reported Outcome Measures

INTRODUCTION

Patient-reported outcome measures (PROMs) are used to assess performance and value. The type of health insurance coverage may influence outcomes scores. The goal of this study was to determine if the type of insurance coverage is associated with the trends in PROMs within an orthopaedic cohort.

METHODS

We reviewed the electronic medical records of 10,745 adult foot and ankle patients who completed PROMs questionnaires from 2015 to 2017. Patients completed the Foot and Ankle Ability Measure, PROMIS Global-Mental, PROMIS Global-Physical, and PROMIS Physical Function Short Form 10a. Descriptive analyses, analysis of variance, and Tukey HSD (honest significant difference) post hoc analyses were conducted.

RESULTS

Patients with commercial insurance consistently had the highest outcomes scores, whereas those with Workers Comp/Motor Vehicle and Medicaid had the lowest. PROMs of patients with commercial insurance were statistically significantly higher than the pooled scores of all other patients. Markedly poorer scores were also seen for Workers Comp/Motor Vehicle and Medicaid. In addition, these differences in PROMs for Workers Comp/Motor Vehicle and Medicaid exceeded the minimal clinically important differences. Patients with Medicare or Free Care had generally lower scores than the pooled averages, but these results were not statistically significant.

DISCUSSION

PROMs scores vary between the patients with different insurance types in an orthopaedic foot and ankle cohort. These data suggest that patient insurance type may affect patient-reported outcomes.

LEVEL OF EVIDENCE

Level III, Retrospective Cohort.

Physical prognostic factors predicting outcome following lumbar discectomy surgery: systematic review and narrative synthesis

BACKGROUND

Success rates for lumbar discectomy are estimated as 78-95% patients at 1-2 years post-surgery, supporting its effectiveness. However, ongoing pain and disability is an issue for some patients, and recurrence contributing to reoperation is reported. It is important to identify prognostic factors predicting outcome to inform decision-making for surgery and rehabilitation following surgery. The objective was to determine whether pre-operative physical factors are associated with post-operative outcomes in adult patients [≥16 years old] undergoing lumbar discectomy or microdiscectomy.

METHODS

A systematic review was conducted according to a registered protocol [PROSPERO CRD42015024168]. Key electronic databases were searched [PubMed, CINAHL, EMBASE, MEDLINE, PEDro and ZETOC] using pre-defined terms [e.g. radicular pain] to 31/3/2017; with additional searching of journals, reference lists and unpublished literature. Prospective cohort studies with ≥1-year follow-up, evaluating candidate physical prognostic factors [e.g. leg pain intensity and straight leg raise test], in adult patients undergoing lumbar discectomy/microdiscectomy were included. Two reviewers independently searched information sources, evaluated studies for inclusion, extracted data, and assessed risk of bias [QUIPS]. GRADE determined the overall quality of evidence.

RESULTS

1189 title and abstracts and 45 full texts were assessed, to include 6 studies; 1 low and 5 high risk of bias. Meta-analysis was not possible [risk of bias, clinical heterogeneity]. A narrative synthesis was performed. There is low level evidence that higher severity of pre-operative leg pain predicts better Core Outcome Measures Index at 12 months and better post-operative leg pain at 2 and 7 years. There is very low level evidence that a lower pre-operative EQ-5D predicts better EQ-5D at 2 years. Low level evidence supports duration of leg pain pre-operatively not being associated with outcome, and very low-quality evidence supports other factors [pre-operative ODI, duration back pain, severity back pain, ipsilateral SLR and forward bend] not being associated with outcome [range of outcome measures used].

CONCLUSION

An adequately powered low risk of bias prospective observational study is required to further investigate candidate physical prognostic factors owing to existing low/very-low level of evidence.

[Can epidemiological factors affect the 2-year outcomes after surgery for degenerative lumbar disease in terms of quality of life, disability and post-surgical pain?]

PURPOSE

To evaluate the influence of epidemiological factors on the outcomes of surgery for degenerative lumbar disease in terms of quality of life, disability and chronic pain.

MATERIAL AND METHOD

A total of 263 patients who received surgery for degenerative lumbar disease (2005-2008) were included in the study. The epidemiological data collected were age, gender, employment status, and co-morbidity. The SF-36, Oswestry Disability Index (ODI), Core Outcomes Measures Index (COMI), and VAS score for lumbar and sciatic pain were measure before and 2 years after surgery. The correlation between epidemiological data and questionnaire results, as well as any independent prognostic factors, were assessed in the data analysis.

RESULTS

The mean age of the patients was 54.0 years (22-86), and 131 were female (49.8%). There were 42 (16%) lost to follow-up. Statistically significant correlations (P<.05) were observed between age, gender, co-morbidity, permanent sick leave, and pre-operative pain with changes in the ODI, COMI, physical and SF-36 mental scales, and lumbar and sciatic VAS. Linear regression analysis showed permanent sick leave and age as predictive factors of disability (β=14.146; 95% CI: 9.09 - 29.58; P<.01 and β=0.334; 95% CI: 0.40 - 0.98, P<.05, respectively), and change in quality of life (β=-8.568; 95% CI: -14.88 - -2.26; p<.01 and β=-0.228, IC 95% CI: -0.40 - -0.06, P<.05, respectively).

CONCLUSION

Based on our findings, age and permanent sick leave have to be considered as negative epidemiologic predictive factors of the outcome of degenerative lumbar disease surgery.

The influence of secondary gain on surgical outcome: a comparison between cervical and lumbar discectomy

Although the expectation of monetary compensation has been associated with failures in lumbar discectomy, the issue has not been investigated in patients undergoing cervical disc surgery. The authors analyzed the relationship between economic forms of secondary gain and surgical outcome in a group of patients with a common pay scale, retirement plan, and disability program. All procedures were performed at the Portsmouth Naval Medical Center between 1993 and 1995; active-duty military servicepersons treated for cervical radiculopathy were prospectively included. Clinical, demographic, and financial factors were analyzed to determine which were predictive of outcome. Financial data were used to create a compensation incentive, which is proportional to the patient's rank, years of service, potential disability, retirement eligibility, and base pay and reflects the monetary incentive of disability. The results of cervical surgery were compared to a previously reported companion population of patients treated for lumbar disc disease. A good outcome was defined as a return to active duty, whereas a referral for disability was considered a poor surgical result. A 100% follow-up rate was obtained for 269 patients who underwent 307 cervical operations. Only 16% (43 of 269) of patients who underwent cervical operation received disability, whereas 24.7% (86 of 348) of patients who underwent lumbar discectomy obtained a poor result (p = 0.0082). Although economic forms of secondary gain were not associated with a poor outcome in cervical disease, both the rank (p = 0.002) and duration (p = 0.03) of an individual's military career were significant factors (p = 0.02). Of the medical variables tested, multilevel surgery (p = 0.03) and revision operations at the same level (p = 0.03) were associated with referral for medical discharge. Secondary gain in the form of economic compensation influences outcome in lumbar but not cervical disc surgery patients; the increased rate of disability referral in patients who underwent lumbar discectomy may reflect an expectation of economic compensation. Social factors that are independent of the anticipation of economic compensation seem to influence the outcome in cervical disc surgery patients.

Should smoking habit dictate the fusion technique?

The aim of this study was to evaluate the influence of smoking on the outcome of patients undergoing surgery for degenerative spinal diseases, and to examine whether smoking had a differential impact on outcome, depending on the fusion technique used. The cohort included 120 patients treated with two different fusion techniques (translaminar screw fixation and TLIF). They were categorised with regard to their smoking habits at the time of surgery and completed the Core Outcome Measures Index at baseline and follow-up (FU) (3, 12 and 24 months FU); at FU they also rated the global outcome of surgery. The distribution of smokers was comparable in the two groups. For the TS group, the greater the number of cigarettes smoked, the less the reduction in pain intensity from pre-op to 24 months FU; the relationship was not significant for the TLIF group. The percentage of good global outcomes declined with time in the TS smokers such that by 24 months FU, there was a significant difference between TS smokers and TS-non-smokers. No such difference between smokers and non-smokers was evident in the TLIF group at any FU time. In conclusion, the TS technique was more vulnerable to the effects of smoking than was TLIF: possibly the more extensive stabilisation of the 360° fusion renders the environment less susceptible to the detrimental effects on bony fusion of cigarette smoking.

An analysis of the prognostic factors affecing the clinical outcomes of conventional lumbar open discectomy : clinical and radiological prognostic factors

Study Design

This is a retrospective study.

Purpose

We wanted to examine the clinical and radiological prognostic factors affecting the postoperative clinical outcome of patients with lumbar disc herniation and who underwent open discectomy.

Overview of Literature

Conventional open discectomy has been widely used as a treatment regimen for the management of lumbar disc herniation. Still, much controversy exists regarding the factors that affect the postoperative clinical outcomes.

Methods

The current study was conducted on 40 patients who were diagnosed with lumbar disc herniation by the senior surgeon of our department from March 2004 to June 2007. These patients were refractory to conservative treatment and they could be followed up for more than one year following their surgical treatments. Preoperatively, after postoperative year 1 and at the final follow-up, a comparison was made for the Oswestry disability index (ODI) scores and the visual analogue scale (VAS) scores that indicated low back pain and radiating pain. For identifying prognostic factors, an analysis was also performed for such factors as age, gender, the operated level, the duration of preoperative low back pain and radiating pain, a smoking history, the body mass index and whether the surgery was revision or the primary operation. A radiological analysis, based on the preoperative plain flexion-extension radiography, was performed for the presence of mild segmental instability of < 3 mm, spondylolysis and disc space narrowing. Pfirrmann's degenerative grade of the disc, the degree of herniation and whether a herniation was central or massive on the magnetic resonance imaging scans.

Results

At the final follow-up, the ODI was significantly higher in the cases of revision as compared with the cases of primary operation. The female gender also had a tendency for a poor ODI as compared with that of the men, but this had only borderline statistical significance. There was significant correlation between the preoperative ODI and the preoperative VAS indicating radiating pain. At a final follow up, the low back pain VAS score was significantly lower in the extruded cases as compared with that of the protruded or sequestrated cases.

Conclusions

Following an analysis for detecting the prognostic factors of open discectomy, the final clinical outcome was found to be poor for the revision surgery cases. In regard to the type of herniation, the degree of low back pain was relatively lower at a final follow-up for the extruded cases as compared with that for the protruded or sequestrated cases. Open discectomy surgery should be performed after evaluating the patients' various prognostic factors that could affect the final clinical outcome.

Assessing patient utilities for varying degrees of low back pain

RATIONALE AND OBJECTIVES

We sought to quantify patient preferences for mild, moderate, and severe low back pain via time-tradeoff analysis and utility measurement.

MATERIALS AND METHODS

Forty-one patients being treated for low back pain in a tertiary care teaching hospital participated in the study. Patients were asked to decide which of three health states they were currently experiencing as well as which of the three health states was the worst experienced during their lifetime. A time-tradeoff analysis was performed, during which patients were asked the amount of time in each of the health states they would exchange for complete resolution of symptoms. We correlated (1) subjects' current health state with reported utility and (2) degree of previous low back pain with results of time-tradeoff measurements.

RESULTS

All patients were willing to trade a greater number of life-years for resolution of symptoms given a more severe perceived health state. Utility decreased as severity of back pain scenarios increased, with an average utility of 0.93 +/- 0.11 for mild, 0.65 +/- 0.21 for moderate, and 0.18 +/- 0.17 for severe pain. No significant difference in time-tradeoff among subjects was identified based upon current health state on the day of interview. A statistically significant difference was seen in patients' willingness to trade time among those who had actually experienced severe pain versus those who had not. Kendall's correlation revealed that subjects who had experienced severe back pain exhibited significantly lower utilities (P < 0.01) compared with subjects who had never experienced severe pain.

CONCLUSIONS

As expected, patients with severe low back pain were willing to sacrifice more potential years of life for resolution of symptoms, suggesting time-tradeoff can accurately reflect patient utility. 2. However, we found no correlation between a subject's current health state and reported utility.

The risk of "getting worse" after lumbar microdiscectomy

A frequent concern among patients operated for lumbar disc herniation is the risk of "getting worse". To give an evidence-based estimate of the risk for worsening has been difficult, since previous studies have been more focused on unfavourable outcome in general, rather than on deterioration in particular. In this prospective study of 180 patients, we report the frequency of and the risk factors for getting worse after first time lumbar microdiscectomy. Follow-up time was 12 months. Primary outcome measure was the Oswestry disability index, assessing functional status and health-related quality of life. Of the patients 4% got worse. Independent risk factors of deterioration were a long duration of sick leave and a better functional status and quality of life prior to operation. We conclude that the risk of deterioration is small, but larger if the patient has been unable to work despite relatively small health problems. This study also demonstrates that changes in instrument scores should be reported, so that an accurate failure rate can be assessed.

Wrong disc space level surgery: medicolegal implications

BACKGROUND

Operating the wrong disc level for herniated disc disease is a rarely reported complication. However, it is considered by many a breach in the standard of care. It is not unusual for litigation to result. Sixty-nine cases of wrong disc space level surgery were identified; 68 cases were the subject of lawsuits.

METHODS

Sixty-five lawsuit outcomes were published in a national monthly newsletter of malpractice cases, Medical Malpractice Verdicts, Settlements and Experts. Two cases came from medicolegal review, one case from a news article, and one case for which no claim was made.

RESULTS

Thirty-seven cases were settled. A plaintiff verdict was rendered in 18 cases and a defense verdict in 13 cases (42% of the cases that were decided by a jury).

CONCLUSIONS

The authors summarize steps to reduce the incidence of this misadventure. The authors recommend that the patient be advised of this potential and the patient be informed of the risk factors when special circumstances exist.

Prospective multiple outcomes study of outpatient lumbar microdiscectomy: should 75 to 80% success rates be the norm?

OBJECT

The authors assessed the efficacy and outcomes of lumbar microdiscectomy performed on an outpatient basis by administering six questionnaires before and at five time points after surgery. The results were compared with those reported in literature in which the success rates vary between 70% and 80% and in excess of 90%. The authors use the methodology and data derived from their study to evaluate critically the relevance of these two categories of success rates.

METHODS

This is a prospective study of 212 consecutive, eligible patients who underwent outpatient microscopic discectomy for the treatment of lumbar disc herniation: no previous lumbar lesion had been treated. Data were collected from questionnaires given to the patients before and at five time points after surgery, including at a variable final follow-up examination (mean 2 years postoperatively). Data were collated and analyzed independently by individuals other than the operating surgeons. In both bi- and multivariate analyses, only two preoperative parameters were prognostically significant. The first factor was Workers' Compensation status, which had a negative effect on outcome. The second factor was patient age, which also had a negative effect and was linear with increasing age between 25 years and 56 years--that is, the ages most commonly encountered in cases of herniated disc. Successful outcome rates were as follows: leg pain relief according to a visual analog scale (VAS), 80%; back pain relief (VAS), 77%; Oswestry Low Back Disability Index, 78%; satisfaction with the results of surgery, 76%; return to normal daily activities, 65%; and return to work, 61%.

CONCLUSIONS

The findings of this study support the evidence that lumbar microdiscectomy performed on an outpatient basis is a very safe and effective means of treating sciatic pain due to disc herniation. The authors believe that their outcome success rates of 75 to 80% are more realistic than those of 90% or more found in some reports.

Theories of musculoskeletal injury causation

Based on the scientific evidence in published literature about precipitation of musculoskeletal injuries in the workplace, four theories have been proposed to explain these afflictions. Central to all theories is the presupposition that all occupational musculoskeletal injuries are biomechanical in nature. Disruption of mechanical order of a biological system is dependent on the individual components and their mechanical properties. These common denominators will be causally affected by the individual's genetic endowment, morphological characteristics and psychosocial makeup, and by the occupational biomechanical hazards. This phenomenon is explained by the Multivariate Interaction Theory. Differential Fatigue Theory accounts for unbalanced and asymmetric occupational activities creating differential fatigue and thereby a kinetic and kinematic imbalance resulting in injury precipitation. Cumulative Load Theory suggests a threshold range of load and repetition product beyond which injury precipitates, as all material substances have a finite life. Finally, Overexertion Theory claims that exertion exceeding the tolerance limit precipitates occupational musculoskeletal injury. It is also suggested that while these theories may explain the immediate mechanism of precipitation of injuries, they all operate simultaneously and interact to modulate injuries to varying degrees in different cases.

Secondary gain influences the outcome of lumbar but not cervical disc surgery

BACKGROUND

The expectation of monetary compensation has been associated with poor outcomes in lumbar discectomy, fueling a reluctance among surgeons to treat worker's compensation cases. This issue, however, has not been investigated in patients undergoing cervical disc surgery. This study analyzes the relationship between economic forms of secondary gain and surgical outcome in a group of patients with common pay scales, retirement plans, and disability programs.

METHODS

All procedures were performed at the Portsmouth Naval Medical Center between 1993 and 1995; active duty military servicepersons who were treated for cervical radiculopathy were prospectively included. Clinical, demographic, and financial factors were analyzed to determine which were predictive for outcome. Financial data were used to create a compensation incentive (CI) which is proportional to the rank, years of service, potential disability, retirement eligibility, and base pay and reflects the monetary incentive of disability. The results of cervical surgery were compared to a previously reported companion population of patients treated for lumbar disc disease. A good outcome is defined as a return to active duty, whereas a referral for disability is considered a poor surgical result.

RESULTS

One hundred percent follow-up was obtained for 269 patients who were treated with 307 cervical operations. Only 16% (43/269) of cervical patients received disability, whereas 24.7% (86/348) of lumbar patients obtained a poor result (p = 0.0082). Although economic forms of secondary gain were not associated with outcome in cervical disease, both the position (p = 0.002) and duration of an individual's military career were significant factors (p = 0.02). Of the medical variables tested, multilevel surgery (p = 0.03) and revision operations at the same level (p = 0.03) were associated with referral for medical discharge.

CONCLUSIONS

Secondary gain in the form of economic compensation influences outcome in lumbar but not cervical disc surgery; this observation may in part account for the success of cervical surgery relative to lumbar discectomy. Social factors that are independent of the anticipation of economic compensation seem to influence the outcome of cervical disc surgery.

Variability of outcome after lumbar disc surgery

STUDY DESIGN

A prospective, consecutive study of patients' outcome at three subsequent follow-up times after lumbar disc surgery.

OBJECTIVES

To evaluate how consistent outcome remained in a group of patients after lumbar disc surgery.

SUMMARY OF BACKGROUND DATA

Despite similar results concerning the overall outcome, results in most studies show different prognostic factors for lumbar disc surgery at different follow-up times. A reason for this observation could be that patients shift to a different outcome group during the observation period.

METHODS

Before surgery and at the three follow-ups (3, 12, and 28 months after surgery) the Low Back Outcome Score was calculated. Groups with favorable and unfavorable outcome were determined after each follow-up according to the scores.

RESULTS

Ninety-eight patients were studied. Forty percent showed an unstable outcome at different follow-up times. For each follow-up, three prognostic factors were determined. No prognostic factor showed significance at all follow-up examinations.

CONCLUSIONS

Patients whose outcome after lumbar disc surgery does not remain stable present a major problem in the calculation of prognostic factors.

Spondylodiscitis after lumbar discectomy. Incidence and a proposal for prophylaxis

STUDY DESIGN

An analysis of the incidence of spondylodiscitis after lumbar disc surgery in 1642 patients. In 508 patients no prophylactic antibiotics were given. In 1134 patients a collagenous sponge containing gentamicin was placed in the cleared disc space.

OBJECTIVES

To report the incidence of postoperative spondylodiscitis in cases in which no antibiotic prophylaxis was used, and to define the value of a collagenous sponge containing gentamicin in preventing disc space infections.

SUMMARY OF BACKGROUND DATA

Spondylodiscitis is considered to be a rare complication of lumbar disc surgery. The retrospective design of most studies and the rare use of magnetic resonance imaging for early radiologic diagnosis suggest that the reported incidence rates may be underestimates. Postoperative spondylodiscitis is the result of intraoperative contamination and, theoretically, could be prevented by treating these patients with prophylactic antibiotics.

METHODS

In 1642 patients, 1712 discectomies were performed. In 508 of these patients no prophylactic antibiotics were given; in 1134 of these patients a collagenous sponge containing gentamicin was placed in the cleared disc space. Clinical reexamination and, in cases of unsatisfactory results, laboratory and radiologic investigations were performed 4-8 weeks after surgery.

RESULTS

In nineteen of the 508 patients who were not treated with antibiotic prophylaxis (3.7%) a postoperative spondylodiscitis developed, whereas none of the 1134 patients who received antibiotic prophylaxis became symptomatic (P < 0.00001).

CONCLUSION

In the current study, a 3.7% incidence of postoperative spondylodiscitis was found in the absence of prophylactic antibiotics. Gentamicin-containing collagenous sponges placed in the cleared disc space were effective in preventing postoperative spondylodiscitis.

Outcome after microdiscectomy: results of a prospective single institutional study

BACKGROUND

Although lumbar microdiscectomy is one of the most frequently performed spinal procedures, little consensus exists in the literature regarding results. Whereas retrospective reports boast success rates as high as 98%, prospective studies are less sanguine with statistics in the 73-77% range.

METHODS

Prospective single-institution outcome study of all patients undergoing virgin unilateral single-level microdiscectomies by study surgeons November 1990 to March 1992. Outcome determined by patient-reported responses to mail questionnaire or phone interview by a disinterested party.

RESULTS

There were 374 patients operated on, average age 42.4 years with mean length of symptoms 9.4 months, and 31.5% were Workman's Compensation cases. Total complication rate was less than 4%, and follow-up was accomplished for 86% of the patients. Overall success rate was 74% using a strict combination of patient-reported pain relief, work status not affected, absence of narcotic use, and satisfaction with the procedure. Using a multivariate logistic regression analysis, only Workman's Compensation claim and length of symptoms (>6 months) were related to success, with a positive outcome in 86% of non-Compensation patients with brief symptoms contrasting with 29% in Compensation cases of greater than 6 months duration.

CONCLUSIONS

A prospective analysis of the frequency of success after microdiscectomy yields results lower than anticipated based on retrospective studies and finds success related to the non-anatomic factors of length of symptoms and Workman's Compensation claims.

Does the choice of outcome scale influence prognostic factors for lumbar disc surgery? A prospective, consecutive study of 121 patients

From January to June 1994, we operated conventionally on 121 consecutive hemiated lumbar disc patients as part of a prospective study. We analysed general data, case histories, neurological findings on admission and all data from imaging investigations and therapy. In addition, all patients received a questionnaire based on the Low Back Outcome Score. Most of the patients (93%) were followed-up for 1 year postoperatively in the same manner. On the Prolo Scale, we obtained a good result in 70%; 76% had a good Low Back Outcome Score. Predictive factors are different for different outcome scales. The preoperative duration of pain, the preoperative duration of paresis and smoking seem to be general predictive factors.

Clinical history in lumbar disc herniation. A prospective study in 160 patients

In a prospective study of 160 consecutive patients who underwent primary surgery for lumbar disc herniation, we investigated the value of clinical history for diagnosing the degree of herniation-the main prognostic factor for the postoperative outcome. At surgery, the patients were classified into two groups: intact anulus (negative exploration or protruding disc) and ruptured anulus (subligamentary perforation or complete perforation). The strongest variables predicting the degree of herniation were duration of leg pain, progressive leg pain, educational level and whether or not the patient had previously undergone non-spinal surgery. In patients with ruptured anulus, the median durations of low back pain and sciatica were 16 and 10 weeks, respectively. The corresponding figures for the group with intact anulus were 79 and 50 weeks. 18% of those with ruptured anulus and 39% of those with intact anulus were undergoing medical or psychiatric treatment for other diagnoses; 32% and 55% had previously undergone non-spinal surgery. Thus the two groups differed not only in disc pathology but also in medical, behavioral and social factors that must be taken into account in the preoperative assessment and that may explain discrepancies between impairment and disability.

Is the outcome of traditional lumbar disc surgery related to the size of the exposure?

The purpose of this study was to evaluate whether wide surgical exposures result in poorer outcome of lumbar disc surgery compared to smaller traditional exposures. The aim was also to assess if a dural tear has any impact on the postoperative clinical outcome. One hundred and twenty-two patients (56 women and 66 men, mean age 40.8 years) with herniated intervertebral lumbar disc and no previous back surgery, were included. Postoperatively they were grouped according to surgery as follows: surgery on one vs. two herniated discs (106 vs. 16 patients), partial vs. full laminectomy (93 vs. 29 patients), and the occurrence or not of a dural rent (8 vs. 114 patients). The outcome of surgery was evaluated one years postoperatively mainly by a composite clinical overall score (COS) and by its separate elements, which were: pain intensity in the lower-back or leg (VAS), neurological and clinical examination, functional capacity (Oswestry), and the need for analgesics. The results of the statistical regression analyses did not reveal significant differences in the postoperative outcome scores in the various groups of patients. The groups were comparable; no significant differences were seen in the pre-operative clinical overall scores.

Long-term results of microlumbar discectomy

A long-term prospective study was carried out of 100 consecutive patients undergoing microlumbar discectomy (MLD) and fulfilling stringent selection criteria. A 95% long-term follow-up result was obtained at a mean duration of 8.6 years. At the 7-11-year assessment, 88% of patients had an excellent result, 5% a good result and 7% had either a poor result or new symptoms. Ten patients (10.5%) underwent repeat MLD during the course of the study; nine of the ten reoperations were performed at the same level as the original surgery. The percentage with an excellent result remained relatively constant (88-89%) throughout the study. No reliable predictors of long-term outcome were identified. The results suggest that microlumbar discectomy compares favourably with other surgical techniques with regard to long-term outcome.

The role of early postoperative CT scan following surgery for herniated lumbar disc

40 patients underwent lumbosacral microdiscectomy in a 12 months period covering the years 1988-1989 in our center. For the purpose of the present study, we considered the 30 cases who underwent CT control of the operated interspaces and of the adjacent vertebral endplates. This was routinely carried out on the 3rd post-operative day. The present study failed to show correlations between early post-operative CT data and subsequent clinical results in this unselected series of patients. In fact an image suggesting persistent disc herniation was as a rule observed in spite of satisfactory clinical results, and other CT findings that have been considered of clinical significance, such as intraspinal air and low attenuation of disc space, were commonly observed in patients with an uncomplicated post-operative course. The present study suggests that early post-operative CT appears to be of no value in the management of potential early complications of low-back surgery. The introduction of MRI appears to offer other possibilities in the evaluation and management of failed back surgery syndrome (FBSS).

Outcome analysis in 654 surgically treated lumbar disc herniations

This article reports the outcomes of 654 consecutive patients treated during a 4.5-year period. Patients had a microdiscectomy, a laminectomy plus microdiscectomy, or a decompressive laminectomy with a microdiscectomy. The causes of ruptured discs were lifting (31.4%), falls (10.2%), and sports (10.0%). Almost all patients had complained of leg pain (99%), and 79% had radicular pain in a dermatomal distribution. Thirty-three percent of the patients had been involved in industrial accidents, and 6% had legal claims pending during the surgical period. Almost 11% of the patients had complications, and there was one death caused by abdominal arterial bleeding. Patients were also rated according to the Prolo Functional-Economic Outcome Rating Scale to improve the ability to compare series in the future. Almost 80% of the patients had good outcomes as defined by scores on this scale of 8 (16.2%), 9 (33.2%), and 10 (26.9%). Several conclusions can be drawn from the results of this series: 1) most patients had good outcomes; 2) patients with nonindustrial injuries had better outcomes than did patients with industrial injuries; 3) professionals with legal concerns and laborers with industrial insurance had good outcomes; and 4) the Functional-Economic Outcome Rating Scale appears to be a useful tool for comparing different procedures more objectively and for comparing the outcomes across series.

Risk factors for low back pain and sciatica

So far, eight prospective studies and 50 cross-sectional or retrospective studies have focused on risk factors for low back syndromes. Half of these have been published during the 1980s. Hard physical work and, in particular, frequent lifting and postural stress are likely to result in disc degeneration, low back pain and sciatica. Physical strain may also have prophylactic effects, as physical leisure activity and muscular strength are negatively associated with the risk of low back pain. Much evidence points to driving motor vehicles being causally associated with low back pain and sciatica. A probably causal relationship exists between body height and risk of sciatica, but height is not necessarily predictive of other types of low back pain. Obesity, smoking, psychological distress and poor general health also carry increased risk of low back pain, but their causal role is questionable. Although none of the suspected risk factors can be described as having been conclusively investigated epidemiologically, the results of published studies show that there are modifiable factors contributing to low back pain. The overall potential of primary prevention is great if adequate tools for intervention can be developed.

Chemonucleolysis versus discectomy: a randomized multicenter trial

A randomized clinical trial was carried out to compare the results of open discectomy with those of chemonucleolysis in 151 patients suffering from a disc herniation at L4-5 or L5-S1. All patients fulfilled strict entry criteria; 78 patients underwent open discectomy and 73 were subjected to chemonucleolysis. An increase in radicular pain immediately after treatment was encountered in 16 patients (22%) in the chemonucleolysis group, as compared to none in the discectomy group. The efficacy of discectomy appeared to be definitely superior to that of chemonucleolysis. Within a follow-up period of 1 year, 18 patients (25%) required open discectomy following failed chemonucleolysis; two patients (3%) in the discectomy group needed a second operation. Open discectomy following previous chemonucleolysis was successful in only 44% of cases. Comparison of the final results of the two modes of treatment 12 months after the last intervention (including second treatment) did not reveal any significant differences. The duration of the preoperative symptoms, the level of disc herniation, and the leakage of contrast medium out of the disc appeared to be of no relevance to the final outcome. The complication rates in both treatment groups were low.

Risk factors of recurrent disc herniation

The causes of 100 disc herniation reoperations are analyzed and discussed in a review: we find a recurrence of disc herniation at the same level in 62% of the reoperated cases, a pseudorecurrence in 24% and a closely connected nerve route in 14%. We reoperated on 44% within the first two years and on 69% within the first five years. The interval between the operations is longer, when there is a short painfree interval following surgery and also a long history of pre-operative symptoms. The variables of risk of prolapse recurrence are recorded as a risk score. Retrospectively, 64% belonged to a risk group according to this score. The correlation between operation intervals and scores show, that patients with a short interval have high scores.

Microsurgical reoperation following lumbar disc surgery. Timing, surgical findings, and outcome in 92 patients

Ninety-two patients who underwent microsurgical reoperation for persistent or new complaints following initial lumbar intervertebral disc surgery were evaluated retrospectively. Sixty percent of all pain relapses occurred within 1 year following the first operation; thereafter, the probability of a relapse declined steadily and was as low as 0.1% per year between 5 and 20 years. The results of microsurgical reoperation in terms of pain relief and working capability were considered "excellent" in 22% of patients, "good" in 30%, and "satisfactory" in 29%. Thus, 81% of the patients could be considered as treated successfully and in 19% the result was not successful. The most common intraoperative findings were: a true recurrence at the same level in 43% of cases, a new herniation at another level in 15%, and a small recurrent fragment embedded in epidural fibrosis in 23%. Five percent of patients had severe epidural fibrosis as the only pathology. In 15%, reoperation was performed within 1 month to treat persisting pain, and either a missed disc fragment, an inadequately decompressed lateral recess, or an unrecognized second-level disc protrusion was found. The clinical outcome is affected predominantly by the intraoperative pathology and the time interval between the first and second operation. An excellent or good outcome was usually achieved in patients with a recurrence of pain after 1 year resulting from a true recurrent disc or a new herniation at another level. In contrast, very unfavorable results were noted with most reoperations performed during the 1st year when extensive epidural fibrosis (or fibrosis with a small recurrence) was present.

Long-term prospective study of lumbosacral discectomy

A long-term prospective study of 100 patients undergoing lumbosacral discectomy was carried out in an attempt to delineate the natural history of these patients and to assess the relative significance of preoperative factors as determinants of long-term outcome. Neurological findings were documented preoperatively and at 1 month, 1 year, and 5 to 10 years postoperatively. A questionnaire using subjective and objective data was given to patients at 1 year and 5 to 10 years postoperatively. An 83% long-term follow-up result was obtained. At a minimum of 5 years postoperatively, 62% of patients had complete relief of back pain and 62% had complete relief of leg pain; 96% were pleased that they had submitted to surgery and 93% were able to return to work. Nine percent reported that their back pain at 5 to 10 years was as severe as or worse than preoperatively and 11% reported that their leg pain was as severe as or worse than preoperatively. The reoperation rate was 18%. Preoperative factors found to be significantly associated with outcome at 1 year postoperatively were not significantly associated with outcome at 5 to 10 years postoperatively. The results of lumbosacral discectomy appear favorable as evaluated in this study. Preoperative factors useful as predictors of short-term outcome are much less reliable when considering the long-term results.

Results of microsurgical lumbar discectomy. Review on 485 patients

485 patients with a lumbar disc herniation were operated upon microsurgically. The results, the rate of complications and true recurrent herniations will be presented. The results of the microsurgical technique are compared to the results of the conventional technique. The final outcome after the microsurgical operation was excellent in 39%, good in 34% and satisfactory in 19%, 9% of the patients had a poor final outcome. The results obtained with microsurgery are attained with the standard techniques only by few groups, probably highly experienced surgeons. Following microsurgery a uniformly high percentage (88-98%) of results are reported as being satisfactory, whereas the analogous figures range between 40 and 98% following the standard technique.

Sciatica--management by chemonucleolysis versus surgical discectomy

Two therapeutic approaches designed specifically to relieve the symptoms of sciatica and resolve the signs of lumbar radiculopathy brought about by herniation of the nucleus pulposus have evolved. The surgical removal of the lumbar disc is an operation which has undergone miniaturization in recent years. Treatment of disc hernia by chemical hydrolysis of the nucleus pulposus (chemonucleolysis) has, over the past 20 years, become an alternative to open surgical treatment. These two forms of therapy are compared as to their efficacy and safety. Neurosurgeons now have the data to decide on the suitability of employing one or the other (or both) of these forms of treatment in the care of patients with intractable sciatica.

Predictability of the result of surgical intervention in patients with low back pain

Patients who were to undergo surgical intervention for low back pain were investigated preoperatively. The effect of surgical intervention was determined after 6 months. The judgement of the neurosurgeon and of the patients themselves were used to assign patients to three outcome categories: satisfactory, moderate and unsatisfactory. Differences in several psychological and biological factors were found between the three categories. On the basis of preoperatively assembled data on psychological and other variables it is possible to predict the outcome of surgical intervention in 80% of the patients.