Surgical management of adjacent level degeneration following lumbar spine fusion

The treatment of lumbar adjacent segment pathology after a previous lumbar surgery: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To perform a systematic review, evaluating the best available evidence regarding the treatment of lumbar adjacent segment pathology (ASP) to facilitate clinical recommendations for treatment.

SUMMARY OF BACKGROUND DATA

It is unclear how nonoperative treatment of lumbar clinical ASP (CASP) compares with operative treatment, and it is also unclear if 1 type of operative treatment is superior to another in the treatment of lumbar CASP. Given that ASP occurs with a known frequency after fusion, it is important to understand outcomes for treatment based on the best available evidence.

METHODS

We conducted a systematic search in PubMed and the Cochrane Library for literature published through February 2012 for lumbar ASP. Our first goal was to identify studies comparing operative with nonoperative management of lumbar ASP. Our second goal was to identify studies comparing operative with operative management of lumbar CASP. Our third goal was to identify case series evaluating outcomes after the treatment of lumbar CASP. The overall body of evidence with respect to each clinical question was determined on the basis of precepts outlined by the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) working group and recommendations made by the Agency for Healthcare Research and Quality.

RESULTS

No studies comparing operative with nonoperative management or comparing operative with operative management of CASP were identified in the literature. Eight case series were identified for the treatment of CASP with decompression alone, decompression and fusion, or decompression and disc arthroplasty.

CONCLUSION

The strength of evidence supporting these clinical questions was insufficient based on GRADE criteria; therefore, conclusions are based on the best available evidence and clinical experience. Operative management for lumbar CASP should be considered after failure of nonoperative management. When considering the type of operative treatment for lumbar CASP, clinical judgment, radiographical appearance, and patient preference should guide operative intervention. If a patient's disability secondary to lumbar CASP is high enough, consideration should be given to operative treatment. All these recommendations are weak based on GRADE.

CONSENSUS STATEMENT

1. Operative management for lumbar ASP should be considered after failure of nonoperative management of ASP. Strength of Statement: Weak. 2. When considering the type of operative treatment for the treatment of lumbar ASP, clinical judgment, radiographical appearance, and patient preference should guide operative intervention. Strength of Statement: Weak. 3. Although the level of evidence for the outcomes of the treatment of lumbar ASP is weak, there does seem to be some benefit from the surgical treatment of lumbar ASP. Thus, if the patient's disability secondary to lumbar ASP is high enough, consideration should be given to operative treatment. Strength of Statement: Weak.

Lumbar fusion outcomes stratified by specific diagnostic indication

BACKGROUND

One of the primary difficulties in evaluating the effectiveness of lumbar fusion is that, with the exception of spondylolisthesis, specific diagnostic indications for surgery are poorly defined. Diagnostic specificity beyond the symptom of low back pain or the presence of lumbar degeneration needs to be delineated such that outcomes data can be effectively translated into clinical decision making or evidence-based guidelines.

PURPOSE

The purpose of this study was to report on prospectively collected clinical outcome measures, stratified by diagnosis, among a series of patients with lumbar degenerative disease whose treatment included lumbar spine fusion.

STUDY DESIGN

Demographics, diagnostic categorization, and clinical outcome measures were prospectively collected by six spine surgeons at a single tertiary spine center, as part of the surgeons' standard clinical practice.

PATIENT SAMPLE

Four hundred and twenty-eight patients were enrolled in the study and complete 1- and 2-year Health-Related Quality of Life (HRQOL) data were available in 327 patients whose treatment included decompression and posterolateral lumbar fusion.

OUTCOME MEASURES

The Oswestry Disability Index (ODI), Short Form-36 (SF-36), numeric rating scales for back pain and leg pain.

METHODS

Preoperative diagnosis was classified, in the primary surgical cases, as disc pathology, spondylolisthesis, instability, stenosis, or scoliosis. In revision cases, the diagnosis was classified as nonunion, adjacent level degeneration, or postdiscectomy revision. Patient-reported outcomes at 1 and 2 years post-op were assessed based on diagnostic stratification. Statistical evaluation of clinical outcome was performed for both mean net change in outcome scores and the percentage of patients reaching a minimum clinically important difference (MCID) threshold for each outcome measure.

RESULTS

Preoperative diagnosis was spondylolisthesis (n=80), scoliosis (n=17), disc pathology (n=33), instability (n=21), stenosis (n=46), postdiscectomy revision (n=67), adjacent level degeneration (n=40), or nonunion (n=23). Evaluation of 2-year post-op HRQOL measures by diagnostic subgroup revealed the most substantial improvement in ODI score for patients with spondylolisthesis (22.7 points) and scoliosis (21.2 points). Patients with the diagnosis of disc pathology (16.2 points), postdiscectomy revision (14.0 points), instability (12.7 points), stenosis (10.6 points), and adjacent level degeneration (9.5 points) demonstrated a progressively smaller magnitude of ODI improvement. The least ODI improvement at 2 years after surgery was seen in patients with nonunion of a prior fusion (5.5 points). The percentage of patients reaching MCID for ODI at 2 years post-op ranged from 71.0% in the spondylolisthesis subgroup to 34.8% in the nonunion subgroup. The greatest SF-36 physical component score improvement at 2-year follow-up was seen in patients with disc pathology (7.9 points) and spondylolisthesis (7.7 points), followed by scoliosis (6.6 points) and stenosis (6.5 points), instability (5.6 points), postdiscectomy revision (5.3 points) nonunion (3.1 points) and adjacent level degeneration (2.5 points). No significant changes from Year 1 to Year 2 were noted in any of the subgroups. For SF-36 physical component score, percentage of patients reaching MCID ranged from 63.6% in the disc pathology subgroup to 25% in the nonunion subgroup.

CONCLUSIONS

This study supports the concept that added diagnostic specificity is a critical component in building an improved evidence base for lumbar fusion surgery. The magnitude of HRQOL improvement was not equal among diagnostic subgroups. The percentage of patients reaching an MCID level of improvement was also significantly influenced by diagnostic stratification. Without diagnostic specificity for entities beyond spondylolisthesis, the absence of well-defined study populations will continue to limit our ability to move toward evidence-based decision making.

Clinical outcomes in older patients after posterolateral lumbar fusion

BACKGROUND CONTEXT

Older patients are often advised that their age is a contraindication to lumbar fusion surgery. There is, however, limited available data to support or contradict this assertion. Although prior studies of surgical treatment for lumbar degenerative disease suggest that older patients obtain symptomatic pain relief, an evaluation of fusion outcomes based on modern Health-Related Quality of Life (HRQOL) measures is lacking.

PURPOSE

The purpose of this study was to document clinical outcomes based on standardized HRQOL measures in patients over 65 years of age treated by lumbar decompression and fusion surgery.

DESIGN/SETTING

This study was a retrospective review of prospectively collected patient reported outcomes data.

PATIENT SAMPLE

Ninety-seven consecutive patients over 65 years of age treated by lumbar decompression and fusion between 2000 and 2004 were enrolled in a prospective health status outcomes protocol. Eighty-five patients (88%) had complete data at a minimum 2-year follow-up.

OUTCOME MEASURES

Medical Outcomes Study Short Form 36v.2 (SF-36), Oswestry Disability Index (ODI), numeric rating scales (NRS) back and leg pain scores.

METHODS

Patients over 65 years of age treated by lumbar fusion were evaluated based on HRQOL measures at a minimum of 2 years postoperatively. Variables including history of prior surgery and occurrence of a perioperative complication were evaluated. A comparison group of patients 50 to 64 years of age was also analyzed.

RESULTS

In patients over 65 years old, mean improvement of 6.21 points in SF-36 Physical Composite Score and 5.75 points in SF-36 Mental Composite Score was observed. There was a mean 16.38-point improvement in ODI, 3.08-point improvement in back pain NRS, and 2.65-point improvement in leg pain NRS. SF-36 subscale scores showed improvement for all parameters except general health, where there was a small but statistically significant decline. There was no difference in outcomes at 2 years postoperatively based on the occurrence of a perioperative complication. Patients undergoing a primary lumbar surgical procedure had consistently better outcomes than patients undergoing a revision procedure.

CONCLUSIONS

The results of this study support the efficacy of lumbar decompression and fusion in selected patients over 65 years of age. Occurrence of a perioperative complication did not adversely affect clinical outcome. Patients undergoing a revision procedure should be counseled with regard to the more limited benefits seen with revision surgery.

Two times unlucky: treatment of repeated adjacent vertebral fractures following posterolateral interbody fusion

Posterolateral interbody fusion with cages and posterior fixation is a widespread, accepted method in the treatment of lumbar instability with and without spinal stenosis. Adjacent level instability was occasionally detected in the neighbouring discs. A fracture of the adjacent vertebral body including the upper disc was not reported in the literature. The authors describe a case of a female patient with two time fractures in the adjacent levels-nontraumatic and traumatic-after posterolateral fusion. Recommendations regarding the operative treatment were given.

Range of motion and adjacent level degeneration after lumbar total disc replacement

BACKGROUND CONTEXT

There are no published studies on the relationship between total disc replacement (TDR) motion and the development of adjacent level degeneration (ALD). Because prevention of ALD is the underlying justification for TDR, studies investigating the validity of this concept are essential.

PURPOSE

To examine the relationship between range of motion (ROM) and ALD 8.7 years after lumbar TDR.

STUDY DESIGN/SETTING

Retrospective radiographic and chart review.

PATIENT SAMPLE

Forty-two patients 8.7 years after lumbar TDR.

OUTCOME MEASURES

Radiographic flexion-extension and ALD. Modified Stauffer-Coventry score. Oswestry Disability Questionnaire. Subjective patient ratings of back pain, leg pain, and disability.

METHODS

We reviewed the flexion-extension radiographs of 42 patients 8.7 years after TDR. Cephalad adjacent levels were evaluated for degeneration: loss of disc space height, anterior osteophyte formation, or dynamic flexion-extension instability. Graphical analysis of motion and the prevalence of ALD was performed. A statistical relationship between ALD and clinical outcome was sought.

RESULTS

Ten of 42 patients evaluated (24%) had radiographic ALD. The mean motion was 3.8 degrees +/-2.0 degrees. The patients with ALD had mean motion of 1.6 degrees +/-1.3 degrees whereas the patients without ALD had motion of 4.7 degrees +/-4.5 degrees (p=.035). A clear relationship between motion and the presence of ALD at 8.7-year follow-up was observed. Patients with motion 5 degrees or greater (n=13) had a 0% prevalence of ALD. Patients with motion less than 5 degrees (n=29) had a 34% prevalence of ALD (p=.021, odds ratio 13.5). ALD had no statistically significant effect on clinical outcome although the sample size was small.

CONCLUSIONS

At 8.7-year follow-up, the prevalence of ALD after TDR is higher in patients with motion less than 5 degrees. The presence of ALD had no significant effect on clinical outcome, but the sample size was small. These data suggest that patients with significant ROM after lumbar TDR may have reduced risk for radiographic ALD.

Advantages and disadvantages of nonfusion technology in spine surgery

Nonfusion technology in spine surgery may improve outcomes by reducing surgical morbidity and the incidence of adjacent level degeneration; however, new technologies also introduce new short- and long-term complications. There is currently no evidence that nonfusion implants are superior to fusion in mid- to long-term follow-up. Understanding the potential risks and benefits of nonfusion technology is essential for spine surgeons and their patients. This article reviews the current evidence relating to the potential risks and benefits of nonfusion technology in spine surgery.