Freyr Gauti Sigmundsson

Study Design: A retrospective analysis of prospectively collected registry data. Objective: To examine the subsequent pattern of surgeries and outcome of sacroiliac joint fusions (SJF) in patients previously operated in the lumbar spine as well as those scheduled for primary SJF. Summary of Background Data: Patients with SI joint pain often have a history of previous back surgery, but it is unclear how often patients require back surgery after SI-joint fusion. Methods: We obtained data from the national Swedish spine registry on all patients who underwent a SJF between 1998 and 2019 and identified previous and additional operations of any type after a SJF between 1998 and 2022. The EuroQol EQ VAS and the Oswestry disability index (ODI) were registered preoperatively and 1 year after the last undergone surgery. Satisfaction with treatment was assessed 1 year after surgery. Results: Two hundred seventy-nine patients underwent SJF between 1998 and 2019. Ninety-five of 279 patients (34%) underwent primary SJF, and 184 of 279 patients (66%) underwent SJF after spine surgery. Forty-one of 95 patients (43%) underwent additional spine or SI-joint surgery after a primary SJF. The most common additional procedure was contralateral SJF (22 of 41; 54%). The mean EQ-VAS change after primary SJF was 19 points (95% CI 12–26), whereas the corresponding value for SJF after previous lumbar spine surgery was 9 points (95% CI 2–16). The corresponding values for the mean ODI change were −14 points (95% CI −19 to −10) and -9 points (95% CI −14 to −4) respectively. Seventy-three percent (37 of 51) and 54% (34 of 63) were satisfied after SJF after primary versus secondary SJF. Conclusion: After primary SJF most additional surgeries are for contralateral symptoms and 9% required lumbar surgery after their SJF. Two-thirds of the patients with SJF have had their surgery after lumbar surgery.

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.

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.

Aims: Lumbar disc prolapse is a frequent indication for surgery. The few available long-term follow-up studies focus mainly on repeated surgery for recurrent disease. The aim of this study was to analyze all reasons for additional surgery for patients operated on for a primary lumbar disc prolapse. Methods: We retrieved data from the Swedish spine register about 3,291 patients who underwent primary surgery for a lumbar disc prolapse between January 2007 and December 2008. These patients were followed until December 2020 to record all additional lumbar spine operations and the reason for them. Results: In total, 681 of the 3,291 patients (21%) needed one or more additional operations. More than three additional operations was uncommon (2%; 15/906). Overall, 906 additional operations were identified during the time period, with a mean time to the first of these of 3.7 years (SD 3.6). The most common reason for an additional operation was recurrent disc prolapse (47%; 426/906), followed by spinal stenosis or degenerative spondylolisthesis (19%; 176/906), and segmental pain (16%; 145/906). The most common surgical procedures were revision discectomy (43%; 385/906) and instrumented fusion (22%; 200/906). Degenerative spinal conditions other than disc prolapse became a more common reason for additional surgery with increasing length of follow-up. Most patients achieved the minimally important change (MIC) for the patient-reported outcomes after the index surgery. After the third additional spinal operation, only 20% (5/25) achieved the MIC in terms of leg pain, and 29% (7/24) in terms of the EuroQol five-dimension index questionnaire visual analogue scale. Conclusion: More than one in five patients operated on for a lumbar disc prolapse underwent further surgery during the 13-year follow-up period. Recurrent disc prolapse was the most common reason for additional surgery, followed by spinal stenosis and segmental pain. This study shows that additional operations after primary disc surgery are needed more frequently than previously reported, and that the outcome profoundly deteriorates after the second additional operation. The findings from this study can be used in the shared decision-making process. Cite this article: Bone Joint J 2022;104-B(5):627–632.

Purpose In spine surgery single item patient-reported outcome assessment has been used for many years. Items 1 and 2 of SF-36 are used for assessment of general health. We used these items to explore single item, self-rated, general health assessment after spine surgery. Methods Patients operated for lumbar disc herniation or lumbar spinal stenosis between 2007 and 2017, were recruited from the national Swedish spine register. A total of 16,910 procedures were eligible for analysis. The responsiveness of the SF-36 general health assessment items to surgical treatment was evaluated with the standardized response mean (SRM). Improvement in self-rated general health was used to dichotomize SF-36 profiles and EQ VAS distributions. Results For disc herniation, 5852 (83%) patients reported improvement in general health 1 year after surgery. For spinal stenosis, the corresponding numbers were 6,482 (66%). The additional improvement after year 1 was small. The responsiveness of the SF-36 item 2 (the health transition item) to surgical treatment of disc herniation or spinal stenosis was substantial. There was a clear association between improvement in SF-36 item 2 and improvements in all domains of SF-36. Conclusions Surgery for disc herniation or spinal stenosis improve patients’ perception of general health 1 year after surgery. The improvement in general health after year 1 is limited. The SF-36 item 2 is a responsive measure of self-rated general health that may be used for dichotomization of SF-36 and EQ VAS data when evaluating surgical outcome in spine surgery.

Purpose: Most patients with lumbar disc herniations requiring surgery have concomitant back pain. The purpose of the current study was to evaluate the outcome of surgery for lumbar disc herniations in patients with no preoperative back pain (NBP) compared to those reporting low back pain (LBP). Methods: 15,418 patients surgically treated due to LDH with primary discectomy from 1998 until 2020 were included in the study. Self-reported low back pain assessed with a numerical rating scale (NRS) was used to dichotomize the patients in two groups, patients without preoperative back pain (NBP, NRS = 0, n = 1333, 9%) and patients with preoperative low back pain (LBP, NRS > 0, n = 14,085, 91%). Patient reported outcome measures (PROMs) collected preoperatively and one-year postoperatively were used to evaluate differences in outcomes between the groups. Results: At the one-year follow-up, 89% of the patients in the NBP group were completely pain free or much better compared with 76% in the LBP group. Significant improvement regarding leg pain was seen in all measured PROMs in both groups oneyear after surgery. In the NBP group, 13% reported clinically significant back pain (NRS difference greater than Minimally Clinical Important Difference (MICD)) at the one-year follow-up. Conclusions: Patients without preoperative back pain are good candidates for LDH surgery. 13% of patients without preoperative back pain develop clinically significant back pain one-year after surgery.

Purpose The purpose of the current study was to apply a single large longitudinal EQ-5D-3L data set to several national EQ-5D-3L value sets and explore differences in EQ-5D-3L index density functions and effect sizes before and after treatment. Methods Patients, surgically treated for lumbar spinal stenosis or lumbar disk herniation between 2007 and 2017, were recruited from the national Swedish spine register. A total of 27,328 procedures were eligible for analysis. The EQ-5D health states were coded to EQ-5D-3L summary indices using value sets for 9 countries: Argentina, Australia, Canada, China, Germany, Italy, Sweden, the UK, and the US. The EQ-5D-3L summary index distributions were then estimated with kernel density estimation. The change in EQ-5D-3L index before and after treatment was evaluated with the standardized response mean (SRM). Results There was a high variability in the resulting EQ-5D-3L index density functions. There were also considerable differences in EQ-5D-3L index density functions before and after treatment using the same value set. Effect sizes of 2-year change (SRM), however, were similar when the 9 value sets were applied on pre- and post-treatment data. Conclusions We found a marked variability in EQ-5D-3L index density functions when a single large data set was applied to 9 national EQ-5D-3L value sets. Consequently, studies that aggregate international data, e.g. meta-analyses, may produce misleading results if the underlying differences in EQ-5D-3L index density functions are inadequately handled. On the basis of the results of our study, we recommend against pooling of different national EQ-5D-3L index data.

Study Design: Prospective register cohort study. Objectives: The indication for surgery in patients with lumbar spinal stenosis (LSS) is considered to be leg pain and neurogenic claudication (NC). Nevertheless, a significant part of patients operated for LSS have mild leg pain levels defined as leg pain ≤minimally important clinical difference (MICD). Information is lacking on how to inform these patients about the probable outcome of surgery. The objective was to report the outcome of surgery for LSS in patients with a mild preoperative level of leg pain. Methods: A total of 2559 patients operated upon for LSS with preoperative leg pain ≤3 NRS (Numerical Rating Scale) were evaluated for outcome at the 1-year follow-up. NRS for back pain, the Oswestry Disability Index (ODI), and the EuroQol (EQ-5D) were used. Results: In the period 2007 to 2017, we identified 3239 patients (14%) who had mild leg pain (≤3 on the NRS). In this cohort, leg pain increased 0.40 (0.56-0.37) and back pain decreased 1.0 (0.95-1.2) at the 1-year follow up. ODI decreased 11.1 (10.2-11.4) and the EQ-5D increased 0.15 (0.17-0.14). A total of 31% reached successful outcome in terms of back pain, 43% in terms of ODI and 48% in terms of EQ-5D. 63% of the patients were satisfied with the outcome. Conclusion: A minority of patients with mild leg pain levels operated upon for LSS attain MICD for back pain, ODI, and EQ-5D. The results from this study can aid the surgeon in the shared decision-making process before surgery.

This case report describes a 66-year old woman with Parkinson´s disease and a subacute onset lateral postural deformity. She experienced severe back pain and reduced walking ability. She was diagnosed with Pisa syndrome and sagittal and coronal imbalance was observed on radiographs. Posterior reconstructive surgery was performed from sacrum to Th10. Post operatively, sagittal and coronal imbalance was improved and maintained at the two year follow-up. The patient remained pain free and improvements in walking ability were sustained. The caveats of spine surgery in Parkinson´s patients are discussed and the importance of goal oriented surgery in terms of improvements in sagittal and coronal balance.