Surgically Treated Degenerative Lumbar Spine Diseases in Twins.

BACKGROUND: There is growing evidence to suggest a potential genetic component underlying the development and progression of lumbar spine diseases. However, the heritability and the concordance rates for the phenotypes requiring surgery for the common spine diseases lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH) are unknown. The aim of this study was to determine the heritability and the concordance rates for LSS and LDH requiring surgery by studying monozygotic (MZ) and dizygotic (DZ) twin pairs. METHODS: Patients between 18 and 85 years of age who underwent surgery for LSS or LDH between 1996 and 2022 were identified in the national Swedish spine registry (LSS: 45,110 patients; LDH: 39,272 patients), and matched with the Swedish Twin Registry to identify MZ and DZ twins. Pairwise and probandwise concordance rates, heritability estimates, and MZ/DZ concordance ratios were calculated. RESULTS: We identified 414 twin pairs (92 MZ and 322 DZ pairs) of whom 1 or both twins underwent surgery for LSS. The corresponding number for LDH was 387 twin pairs (118 MZ and 269 DZ pairs). The probandwise concordance rate for LSS requiring surgery was 0.25 (26 of 105) (95% confidence interval [CI], 0.14 to 0.34) for MZ twins and 0.04 (12 of 328) (95% CI, 0.01 to 0.07) for DZ twins. The corresponding values for LDH requiring surgery were 0.03 (4 of 120) (95% CI, 0 to 0.08) and 0.01 (4 of 271) (95% CI, 0 to 0.04), respectively. The probandwise MZ/DZ concordance ratio was 6.8 (95% CI, 2.9 to 21.5) for LSS and 2.3 (95% CI, 0 to 8.9) for LDH. The heritability was significantly higher in LSS compared with LDH (0.64 [95% CI, 0.50 to 0.74] versus 0.19 [95% CI, 0.08 to 0.35]). CONCLUSIONS: Our findings suggest that genetic factors may play an important role in the risk of developing LSS requiring surgery, whereas heredity seems to be of less importance in LDH requiring surgery. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Patient-reported Outcome after Surgical Evacuation of Postoperative Spinal Epidural Hematomas at One-year Follow-up.

STUDY DESIGN: Retrospective analysis of prospectively collected data from the National Swedish Spine Register (Swespine). OBJECTIVE: To evaluate the effects of symptomatic spinal epidural hematoma (SSEH) requiring reoperation on one-year patient-reported outcome measures (PROMs) in a large cohort of patients treated surgically for lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: Studies exploring the outcomes of reoperations after SSEH are scarce and often lack validated outcome measures. As SSEH is considered a serious complication, understanding of the outcome following hematoma evacuation is important. MATERIALS AND METHODS: After retrieving data from 2007 to 2017 from Swespine, we included all patients with LSS without concomitant spondylolisthesis who were treated surgically with decompression without fusion. Patients with evacuated SSEH were identified in the registry. Back/leg pain numerical rating scales (NRS), the Oswestry Disability Index (ODI), and EQ VAS were used for outcome assessment. PROMs before and one-year after decompression surgery were compared between evacuated patients and all other patients. Multivariate linear regression was performed to determine if hematoma evacuation predicted inferior one-year PROM scores. RESULTS: A total of 113 patients with an evacuated SSEH were compared with 19527 patients with no evacuation. One-year after decompression surgery, both groups showed significant improvement in all PROMs. When comparing the two groups' one-year improvement there were no significant differences in any PROM. The proportion of patients achieving the minimum important change was not significantly different for any PROM. Multivariate linear regression found that hematoma evacuation significantly predicted inferior one-year ODI (ß=4.35, P=0.043), but it was not a significant predictor of inferior NRS Back (ß=0.50, P=0.105), NRS Leg (ß=0.41, P=0.221), or EQ VAS (ß=-1.97, P=0.470). CONCLUSIONS: A surgically evacuated SSEH does not affect outcome in terms of back/leg pain or health-related quality of life. Commonly used PROM surveys may not capture neurologic deficits associated with SSEH.

Radiological Definitions of Sagittal Plane Segmental Instability in the Degenerative Lumbar Spine - A Systematic Review.

STUDY DESIGN: Systematic Review. OBJECTIVE: To collect and group definitions of segmental instability, reported in surgical studies of patients with lumbar spinal stenosis (LSS) and/or lumbar degenerative spondylolisthesis (LDS). To report the frequencies of these definitions. To report on imaging measurement thresholds for instability in patients and compare these to those reported in biomechanical studies and studies of spine healthy individuals.To report on studies that include a reliability study. METHODS: This review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Studies eligible for inclusion were clinical and biomechanical studies on adult patients with LDS and/or LSS who underwent surgical treatment and had data on diagnostic imaging. A systematic literature search was conducted in relevant literature databases. Full text screening inclusion criteria was definition of segmental instability or any synonym. Two reviewers independently screened articles in a two-step process. Data synthesis presented by tabulate form and narrative synthesis. RESULTS: We included 118 studies for data extraction, 69% were surgical studies with decompression or fusion as interventions, 31% non-interventional studies. Grouping the definitions of segmental instability according similarities showed that 24% defined instability by dynamic sagittal translation, 26% dynamic translation and dynamic angulation, 8% used a narrative definition. Comparison showed that non-interventional studies with a healthy population more often had a narrative definition. CONCLUSION: Despite a reputation of non-consensus, segmental instability in the degenerative lumbar spine can radiologically be defined as > 3 mm dynamic sagittal translation.

Magnetic Resonance Imaging Proxies for Segmental Instability in Degenerative Lumbar Spondylolisthesis Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim was to investigate whether findings on magnetic resonance imaging (MRI) can be proxies (MRIPs) for segmental instability in patients with degenerative lumbar spinal stenosis (LSS) and/or degenerative spondylolisthesis (LDS) L4/L5. BACKGROUND: LDS has a heterogeneous nature. Some patients have a dynamic component of segmental instability associated with LDS. Studies have shown that MRI can show signs of instability. METHODS: Patients with LSS or LDS at L4/L5 undergoing decompressive surgery±fusion from 2010 to 2017, with preoperative standing lateral spine radiographs and supine lumbar MRI and enrolled in Danish national spine surgical database, DaneSpine. Instability defined as slip of >3 mm on radiographs. Patients divided into two groups based upon presence of instability. Outcome measures: radiograph: sagittal slip (mm). MRIPs for instability: sagittal slip >3 mm, facet joint angle (°), facet joint effusion (mm), disk height index (%), and presence of vacuum phenomena. Optimal thresholds for MRIPs was determined by receiver operating characteristic (ROC) curves and area under the curve (AUC). Logistic regression to investigate association between instability and MRIPs. RESULTS: Two hundred thirty-two patients: 47 stable group and 185 unstable group. The two groups were comparable with regard to baseline patient-reported outcome measures. Thresholds for MRIPs: bilateral facet joint angle ≥46°; bilateral facet effusion ≥1.5 mm and disk height index ≥13%. Logistic regression showed statistically significant association with MRIPs except vacuum phenomena, ROC curve AUC of 0.951. By absence of slip on MRI logistic regression showed statistically significant association between instability on radiograph and the remaining MRIPs, ROC curve AUC 0.757. CONCLUSION: Presence of MRIPs for instability showed statistically significant association with instability and excellent ability to predict instability on standing radiograph in LSS and LDS patients. Even in the absence of slip on MRI the MRIPs had a good ability to discriminate presence of instability.

Reoperations After Decompression With or Without Fusion for L3-4 Spinal Stenosis With Degenerative Spondylolisthesis: A Study of 372 Patients in Swespine, the National Swedish Spine Register.

STUDY DESIGN: Register study with prospectively collected data. OBJECTIVE: The aim was to investigate reoperation rates at the index level and the adjacent levels after surgery for lumbar L3-4 spinal stenosis with concomitant degenerative spondylolisthesis (DS). SUMMARY OF BACKGROUND DATA: There are different opinions on how to surgically address lumbar spinal stenosis with DS. The potential benefit of fusion surgery should be weighed against the risks of future reoperations because of adjacent segment degeneration. Data on the reoperation rate at adjacent segments after single level L3-4 fusion surgery are limited. MATERIALS AND METHODS: A total of 372 patients, who underwent surgery for lumbar L3-4 spinal stenosis with DS (slip >3 mm) between 2007 and 2012, were followed between 2007 and 2017 to identify reoperations at the index level and adjacent levels. The reoperation rate for decompression and fusion was compared with the reoperation rate for decompression only. Patient-reported outcome measures before and 1 year after surgery were evaluated. RESULTS: The reoperation rate at the index level (L3-4) was 3.5% for decompression and fusion and 5.6% for decompression only. At the cranial adjacent level (L2-3), the corresponding numbers were 6.6% and 4.2%, respectively, and the caudal adjacent level (L4-5), the corresponding numbers were 3.1% and 4.9%, respectively. The effect sizes of change were larger for decompression and fusion compared with decompression only. The effect sizes of change were similar for leg pain and back pain. CONCLUSIONS: We could not identify any differences in reoperation rates at the cranial or caudal adjacent segment after decompression and fusion compared with decompression only for L3-4 spinal stenosis with DS. The improvement in back pain is similar to the improvement in leg pain after surgery for L3-4 spinal stenosis with DS.

Consensus statement for perioperative care in lumbar spinal fusion: Enhanced Recovery After Surgery (ERAS®) Society recommendations.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) evidence-based protocols for perioperative care have led to improvements in outcomes in numerous surgical areas, through multimodal optimization of patient pathway, reduction of complications, improved patient experience and reduction in the length of stay. ERAS represent a relatively new paradigm in spine surgery. PURPOSE: This multidisciplinary consensus review summarizes the literature and proposes recommendations for the perioperative care of patients undergoing lumbar fusion surgery with an ERAS program. STUDY DESIGN: This is a review article. METHODS: Under the impetus of the ERAS® society, a multidisciplinary guideline development group was constituted by bringing together international experts involved in the practice of ERAS and spine surgery. This group identified 22 ERAS items for lumbar fusion. A systematic search in the English language was performed in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Systematic reviews, randomized controlled trials, and cohort studies were included, and the evidence was graded according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. Consensus recommendation was reached by the group after a critical appraisal of the literature. RESULTS: Two hundred fifty-six articles were included to develop the consensus statements for 22 ERAS items; one ERAS item (prehabilitation) was excluded from the final summary due to very poor quality and conflicting evidence in lumbar spinal fusion. From these remaining 21 ERAS items, 28 recommendations were included. All recommendations on ERAS protocol items are based on the best available evidence. These included nine preoperative, eleven intraoperative, and six postoperative recommendations. They span topics from preoperative patient education and nutritional evaluation, intraoperative anesthetic and surgical techniques, and postoperative multimodal analgesic strategies. The level of evidence for the use of each recommendation is presented. CONCLUSION: Based on the best evidence available for each ERAS item within the multidisciplinary perioperative care pathways, the ERAS® Society presents this comprehensive consensus review for perioperative care in lumbar fusion.

Outcome of decompression with and without fusion in spinal stenosis with degenerative spondylolisthesis in relation to preoperative pain pattern: a register study of 1,624 patients.

BACKGROUND CONTEXT: Patients with spinal stenosis with concomitant degenerative spondylolisthesis (DS) and predominant back pain (PBP) have been shown to have inferior outcome after surgery. Studies comparing outcome according to preoperative pain predominance and treatment received are lacking. PURPOSE: The purpose was to study if adding spinal fusion to the decompression in DS affects outcome in patients with PBP (back pain [BP] Visual Analog Scale [VAS] more than or equal to leg pain [LP] VAS) compared with predominant leg pain (PLP) (BP VAS less than LP VAS). PATIENT SAMPLE: The Swedish Spine Register was used and included 1,624 patients operated for DS at the L4-L5 level. OUTCOME MEASURES: Self-reported measures were used, including a VAS for BP and LP, the EuroQol-5D (EQ-5D), and the physical and mental component summaries of the Short-Form 36 to estimate health-related quality of life and the Oswestry disability index (ODI) to estimate function. METHODS: Inclusion criterion was single-level DS operated on with either decompression only (D) or decompression and instrumented posterolateral fusion (DF). Based on preoperative LP and BP scores, the patients were assigned to one of the two groups: LP predominance or BP predominance. The patients completed the outcome protocol at 1- and 2-year follow-ups. Statistical analysis was performed using linear regression adjusting for multiple potential confounders. RESULTS: In the adjusted outcome at the 1-year follow-up, patients with PLP reported a 7.9-mm more improvement on the VAS for BP with fusion, compared with D (95% confidence interval [CI], 0.7-15.2), p=.03. Despite more change in the fused group, the reported BP levels remained similar in the D versus decompressed and fused at the 1-year follow-up (28 vs. 24, p=.77). The patients with PBP benefited from adding fusion in terms of BP 7.1 (95% CI, 0.3-13.9, p=.04), LP 8.8 (2-15.7, p=.01), the ODI 5.7 (1.6-9.9, p=.006), and the EQ-5D 0.09 (1.7-0.02, p=.02) at the 1-year follow-up as the DF group reported greater change in the outcome compared with the D group. At the 2-year follow-up, no significant differences were found between D and decompressed and fused in either the LP or the PBP groups. CONCLUSIONS: Patients with PBP operated with DF report better outcomes in terms of pain, function, and health-related quality of life than patients with D. Although these differences are significant on a group level, they may fail to reach minimal clinical significant difference. Patients with PLP report significantly more improvement in terms of BP with DF compared with D, but because of baseline differences in preoperative BP, these improvements may not be explained by the added fusion per se. At the 2-year follow-up, no significant differences were observed between the D and DF patients in either the PBP or PLP groups, but greater loss to follow-up in the DF groups could potentially bias these findings.

Prognostic factors in lumbar spinal stenosis surgery.

BACKGROUND AND PURPOSE: A considerable number of patients who undergo surgery for spinal stenosis have residual symptoms and inferior function and health-related quality of life after surgery. There have been few studies on factors that may predict outcome. We tried to find predictors of outcome in surgery for spinal stenosis using patient- and imaging-related factors. PATIENTS AND METHODS: 109 patients in the Swedish Spine Register with central spinal stenosis that were operated on by decompression without fusion were prospectively followed up 1 year after surgery. Clinical outcome scores included the EQ-5D, the Oswestry disability index, self-estimated walking distance, and leg and back pain levels (VAS). Central dural sac area, number of levels with stenosis, and spondylolisthesis were included in the MRI analysis. Multivariable analyses were performed to search for correlation between patient-related and imaging factors and clinical outcome at 1-year follow-up. RESULTS: Several factors predicted outcome statistically significantly. Duration of leg pain exceeding 2 years predicted inferior outcome in terms of leg and back pain, function, and HRLQoL. Regular and intermittent preoperative users of analgesics had higher levels of back pain at follow-up than those not using analgesics. Low preoperative function predicted low function and dissatisfaction at follow-up. Low preoperative EQ-5D scores predicted a high degree of leg and back pain. Narrow dural sac area predicted more gains in terms of back pain at follow-up and lower absolute leg pain. INTERPRETATION: Multiple factors predict outcome in spinal stenosis surgery, most importantly duration of symptoms and preoperative function. Some of these are modifiable and can be targeted. Our findings can be used in the preoperative patient information and aid the surgeon and the patient in a shared decision making process.

Correlation between disability and MRI findings in lumbar spinal stenosis: a prospective study of 109 patients operated on by decompression.

BACKGROUND AND PURPOSE: MRI is the modality of choice when diagnosing spinal stenosis but it also shows that stenosis is prevalent in asymptomatic subjects over 60. The relationship between preoperative health-related quality of life, functional status, leg and back pain, and the objectively measured dural sac area in single and multilevel stenosis is unknown. We assessed this relationship in a prospective study. PATIENTS AND METHODS: The cohort included 109 consecutive patients with central spinal stenosis operated on with decompressive laminectomy or laminotomy. Preoperatively, all patients completed the questionnaires for EQ-5D, SF-36, Oswestry disability index (ODI), estimated walking distance and leg and back pain (VAS). The cross-sectional area of the dural sac was measured at relevant disc levels in mm², and spondylolisthesis was measured in mm. For comparison, the area of the most narrow level, the number of levels with dural sac area < 70 mm², and spondylolisthesis were studied. RESULTS: Before surgery, patients with central spinal stenosis had low HRLQoL and functional status, and high pain levels. Patients with multilevel stenosis had better general health (p = 0.04) and less leg and back pain despite having smaller dural sac area than patients with single-level stenosis. There was a poor correlation between walking distance, ODI, the SF-36, EQ-5D, and leg and back pain levels on the one hand and dural sac area on the other. Women more often had multilevel spinal stenosis (p = 0.05) and spondylolisthesis (p < 0.001). Spondylolisthetic patients more often had small dural sac area (p = 0.04) and multilevel stenosis (p = 0.06). INTERPRETATION: Our findings indicate that HRQoL, function, and pain measured preoperatively correlate with morphological changes on MRI to a limited extent.

No difference in health-related quality of life in hip osteoarthritis compared to degenerative lumbar instability at pre- and 1-year postoperatively: a prospective study of 101 patients.

BACKGROUND: Total hip replacement (THR) is a very successful and refined surgical procedure when compared to crude bony fusion in degenerative lumbar segmental instability (LF). We compared the pre- and postoperative health-related quality of life status of THR and LF patients. PATIENTS AND METHODS: We prospectively studied 51 THR patients and 50 LF patients. The outcome parameters were SF-36 and Oswestry Disability Index (ODI), measured preoperatively and at 1 year postoperatively. The status of the patients was compared to that of an age-matched healthy control group. RESULTS: The preoperative SF-36 and ODI scores were similar between the groups, except for the subscale role emotional. One year postoperatively, only the differences in 3 subscales (physical functioning, role physical, and role emotional) and in the standardized physical component reached statistical significance; the THR-patients scored worse than the LF-patients. The improvements in SF-36 and ODI reached statistical significance in both groups. INTERPRETATION: The differences in quality of life between the THR and LF patients were similar pre- and postoperatively. The quality of life of both cohorts improved considerably and significantly after the treatment, but they remained at a level significantly below that of a general age-matched population.