Inferior long-term outcomes after surgery for lumbar disc herniation in patients with prior lumbar spine surgery

BACKGROUND

Previous lumbar spine surgery is a frequent exclusion criterion for studies evaluating lumbar surgery outcomes. In real-life clinical settings, this patient population is important, as a notable proportion of patients evaluated for lumbar spine surgery have undergone prior lumbar surgery already previously. Knowledge about the long-term outcomes after microdiscectomy on patients with previous lumbar surgery and how they compare to those of first-time surgery is lacking.

METHODS

The original patient cohort for screening included 615 consecutive patients who underwent surgery for lumbar disc herniation, with a median follow-up time of 18.1 years. Of these patients, 89 (19%) had undergone lumbar spine surgery prior to the index surgery. Propensity score matching (based on age, sex, and follow-up time) was utilized to match two patients without prior surgery with each patient with a previous surgery. The primary outcome measure was the need for further lumbar spine surgery during the follow-up period, and the secondary outcome measures consisted of present-time patient-reported outcome measures (Oswestry Disability Index, EuroQol-5D) and present-time ability to carry out employment.

RESULTS

Patients who received previous lumbar surgeries had a higher need for further surgery (44% vs. 28%, p = 0.009) and had a shorter time to further surgery than the propensity score-matched cohort (mean Kaplan-Meier estimate, 15.7 years vs. 19.8 years, p = 0.008). Patients with prior surgery reported inferior Oswestry Disability Index scores (13.7 vs. 8.0, p = 0.036). and EQ-5D scores (0.77 vs. 0.86, p = 0.01). In addition, they had a higher frequency of receiving lumbar spine-related disability pensions than the other patients (12% vs. 1.9%, p = 0.01).

CONCLUSIONS

Patients with previous lumbar surgery had inferior long-term outcomes compared to patients without prior surgery. However, the vast majority of these patients improved quickly after the index surgery. Furthermore, the difference in the patients' reported outcomes was small at the long-term follow-up, and they reported high satisfaction with the results of the study surgery. Hence, surgery for these patients should be considered if surgical indications are met, but special care needs must be accounted for when deliberating upon their indications for surgery.

Comparable long-term outcomes in patients undergoing total disc replacement or anterior cervical discectomy and noninstrumented fusion

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) is the leading surgical treatment for cervical radiculopathy. However, ACDF surgery has been suggested for to accelerate the degeneration of the adjacent cervical discs, which causes so-called adjacent segment disease (ASD). Over the past 2 decades, total disc replacement (TDR)/cervical disc arthroplasty (CDA) has become an increasingly common method for treating degenerative cervical diseases. The rationale is that a synthetic disc prosthesis may preserve motion at the operated level, which is expected to lead to reduced stress on the other cervical levels and thus decrease the risk of developing ASD. However, since the method was first introduced in the early 2000s, the long-term outcome after it is still not completely understood.

PURPOSE

Our goal was to compare the long-term outcomes of TDR and ACDF procedures.

STUDY DESIGN

Retrospective case-control study.

PATIENT SAMPLE

All patients who underwent TDR due to degenerative cervical disease at Helsinki University Hospital between 2006 and 2012 (38 patients) and matched control patients who underwent ACDF during this period (76 patients) for degenerative disc disease.

OUTCOME MEASURES

The primary outcome measure was the rate of reoperations and further cervical surgeries. Secondary outcome measures included neck symptoms (Neck Disability Index, or NDI), health-related quality of life (EQ-5D-3L), satisfaction with the surgery, radiological outcomes, and employment status.

METHODS

The medical records of all patients who underwent TDR due to degenerative cervical disease at Helsinki University Hospital between 2006 and 2012 and those of the matched control patients were analyzed retrospectively. Questionnaires were sent to all available patients at the end of the follow-up (median 14 years) to evaluate their employment status, levels of satisfaction with the surgery, current neck symptoms, and health-related quality of life. Radiological outcomes were evaluated from the cervical plain radiographs, which were taken either at the end of the follow-up as a part of the present study or earlier on for other clinical reasons, but at least 2 years after index surgery.

RESULTS

The total rate of reoperations and further cervical surgeries during the follow-up of a median of 14 years was 7/38 (18%) in the TDR group and 6/76 (8%) in the ACDF group (p=.096, ns.). Total disc replacement patients were reoperated earlier, and the 5-year reoperation rate was significantly higher in the TDR group (11% vs 1.3%, p=.026). None of the TDR patients underwent further cervical surgery more than 6 years after index surgery, whereas 5/6 (83%) of the reoperated ACDF patients were reoperated after that time. There were no significant differences in the NDIs between the patient groups. The employment rate and health-related quality of life were slightly higher in the TDR group, but the differences were statistically nonsignificant. TDR was significantly better at maintaining the angular range of motion at the operated level, and the fusion rate was significantly lower among this group.

CONCLUSIONS

There were no significant differences in the long-term outcomes of ACDF and TDR when measured by reoperation rates, employment status, NDI, EuroQoL, and satisfaction with surgery. Reoperation rate and, on the other hand, employment rate and health-related quality of life, were higher in the TDR group, but the differences were statistically nonsignificant. However, TDR patients were reoperated earlier, and the 5-year reoperation rate was significantly higher in the TDR group. Randomized long-term studies in which these methods are compared are needed to further clarify the differences between them.

Long-Term Follow-Up After Cervical Laminectomy without Fusion for Cervical Spondylotic Myelopathy

OBJECTIVE

The objectives were to study the effect of cervical laminectomy without fusion on the incidence of further cervical surgeries, the risk for cervical misalignment, and current functional status.

METHODS

We retrospectively analyzed the clinical data of 340 patients who had undergone simple laminectomy for cervical spondylotic myelopathy (CSM) at Helsinki University Hospital between 2000 and 2011.

RESULTS

Forty-one patients (12.1%) had later undergone another cervical surgery during the follow-up of a mean of 8.5 years (maximum, 17.5 years). The most common indication for further surgery was residual stenosis at adjacent or other cervical levels (34%). Five patients (1%) required further surgery for correction of a sagittal balance problem. The mean Neck Disability Index was 28% at a median of 9.0 years after laminectomy. The mean EQ-5D (EuroQol 5 Dimension 3 Level) index score was 58.8 for patients and 77.2 for age-matched and gender-matched general population controls (P = 0.000), indicating patients' reduced health-related quality of life. Worse preoperative condition in the Nurick score was related to a lower (i.e., worse) EQ-5D score. In an additional arm of the study with radiographic imaging (40 patients), the mean change in sagittal alignment was 4.0° toward lordotic, and a newly developed kyphosis was found in 7.5% of patients.

CONCLUSIONS

Because CSM is a serious degenerative progressive condition resulting in decreased health-related quality of life even after surgical treatment, the low rate of corrective surgery needed for alignment issues per se indicates that simple laminectomy can be a viable treatment option in treating multilevel CSM.

Anterior cervical discectomy and fusion in young adults leads to favorable outcome in long-term follow-up

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) procedures is thought to lead to accelerated degeneration of the adjacent cervical discs and in some cases can be symptomatic (adjacent segment disease, or ASD). The occurrence of ASD is of particular interest when treating young individuals, as the cumulative disease burden may become increasingly significant during their expectedly long lifetime. However, the overall impact of a surgical intervention on the lifetime prognosis of ASD remains unclear.

PURPOSE

Our goal was to study the long-term outcomes of ACDF surgery among those members of the young adult population who have been operated on between the ages of 18 and 40.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

All patients between 18 and 40 years of age at the time of surgery who underwent ACDF due to degenerative cervical disorders at Helsinki University Hospital between the years of 1990 and 2005 (476 patients).

OUTCOME MEASURES

Cervical reoperation rate, satisfaction with the surgery, employment status, Neck Disability Index (NDI).

METHODS

We retrospectively analyzed the medical records of all patients between 18 and 40 years of age at the time of surgery who underwent ACDF due to degenerative cervical disorders at Helsinki University Hospital between the years of 1990 and 2005. We sent questionnaires to all available patients at the end of the follow-up (median 17.5 years) to assess their current neck symptoms, general situations, and levels of satisfaction with the surgery. Furthermore, we compared the results for different types of ACDF surgeries (ie, discectomy only vs. synthetic cage or bone autograft implantation for fusion) in propensity-score-matched groups.

RESULTS

Of the 476 patients who were included in the study, surgery was performed in 72% of the cases due to intervertebral disc herniation and in 28% due to spondylotic changes. The total reoperation rate during the entire follow-up (median 17.5 years) was 24%, and 19.5% if early reoperations (<28 days from index surgery) were excluded. At 10 years postsurgery, the total reoperation rate was 16.8% and 12.8% with early reoperations excluded. The probability of surgery for adjacent level disease was 10.3% at 10 years and 16.8% for the duration of the entire follow-up, with the annual incidence rate of 1.1% for those with ASD requiring surgery. Statistically significant risk factors leading to the need for further cervical surgery included central spinal cord compression and smoking at the time of the index operation. After propensity score matching, there was no significant difference found between the outcomes of different types of surgery. A total of 443 patients were still able to be contacted 12-28 years after the surgery. Of the 281 patients responding to the questionnaires, 92% were still satisfied with the results. With respect to employment, 67% of patients were working, 7% were unemployed, and 7% were on disability due to cervical problems. The median NDI score was 12%, with 56% of patients having an NDI score lower than 15%; it has been suggested that this latter NDI score serves as a cut-off value for significant neck morbidity. The NDI scores were significantly higher among female patients, patients with spondylosis, and patients having undergone further cervical surgeries during the follow-up.

CONCLUSIONS

Long-term satisfaction with the surgery was very high, and the employment rate among patients resembled that of the general population in Finland. Thus, the long-term prognosis after having ACDF surgery at a younger age seems to be good, even though nearly half of the patients experienced some persistent neck symptoms later in life.