Stand-alone ALIF versus TLIF in patients with low back pain - A propensity-matched cohort study with two-year follow-up.

Introduction: Instrumented lumbar fusion by either the anterior or transforaminal approach has different advantages and disadvantages. Few studies have compared PatientReported Outcomes Measures (PROMs) between stand-alone anterior lumbar interbody fusion (SA-ALIF) and transforaminal lumbar interbody fusion (TLIF). Research question: This is a register-based dual-center study on patients with severe disc degeneration (DD) and low back pain (LBP) undergoing single-level SA-ALIF or TLIF. Comparing PROMs, including disability, quality of life, back- and leg-pain and patient satisfaction two years after SA-ALIF or TLIF, respectively. Material and methods: Data were collected preoperatively and at one and two-year follow-up. The primary outcome was Oswestry Disability Index (ODI). The secondary outcomes were patient satisfaction, walking ability, visual analog scale (VAS) scores for back and leg pain, and quality of life (QoL) measured by the European Quality of Life-5 Dimensions (EQ-5D) index score. To reduce baseline differences between groups, propensity-score matching was employed in a 1:1 fashion. Results: 92 patients were matched, 46 S A-ALIF and 46 TLIF. They were comparable preoperatively, with no significant difference in demographic data or PROMs (P > 0.10). Both groups obtained statistically significant improvement in the ODI, QoL and VAS-score (P < 0.01), but no significant difference was observed (P = 0.14). No statistically significant differences in EQ-5D index scores (P = 0.25), VAS score for leg pain (P = 0.88) and back pain (P = 0.37) at two years follow-up. Conclusion: Significant improvements in ODI, VAS-scores for back and leg pain, and EQ-5D index score were registered after two-year follow-up with both SA-ALIF and TLIF. No significant differences in improvement.

Radiographic and Functional Outcome in Adolescent Idiopathic Scoliosis Operated With Hook/Hybrid Versus All-Pedicle Screw Instrumentation-A Retrospective Study in 149 Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare radiographic outcome and health-related quality of life in patients with adolescent idiopathic scoliosis (AIS) treated with hook/hybrid (H/H) or all-pedicle screw (PS) instrumentation. SUMMARY OF BACKGROUND DATA: PS instrumentation has largely replaced H/H in the surgical treatment of AIS but whether a normalized sagittal profile can be obtained with the PS construct is still debated. Additionally, comparative studies assessing HRQL and surgical complications are needed. METHODS: Two consecutive series of surgically treated AIS patients were included. Surgical treatment consisted of H/H or low-profile all-PS instrumentation. Radiographic and clinical follow-up, including SRS-22r questionnaires, was performed a minimum of two years postoperatively. RESULTS: There were 85 and 64 patients in the H/H and PS group, respectively. The groups did not differ on baseline parameters apart from a lower flexibility in the H/H group (34% ± 14% vs. 39% ± 14% in the PS group, p = .026). Mean curve correction at final follow-up was 31% ± 13% versus 49% ± 12% in the H/H and PS group, respectively (p < .001), and mean loss of correction was 7° versus 4° (p < .001). The Cincinnati correction index was significantly higher in the PS group at final follow-up (p < .001). Postoperative thoracic kyphosis was significantly higher in the H/H group (27° ± 11° vs. 22° ± 11° in the PS group) with a mean change in kyphosis of 3° ± 9° versus -3° ± 12° in the H/H and PS group, respectively. SRS-22 scores did not differ between the two groups (p > .090), and the reoperation rate at final follow-up was 9% in the H/H group and 6% in the PS group (p = .556). CONCLUSIONS: In a large consecutive cohort of AIS patients followed for a minimum of two years, we found a significantly better curve correction and less loss of correction with PS instrumentation compared to H/H. There was no significant difference in SRS-22r scores at final follow-up. LEVEL OF EVIDENCE: Level III.

Radiographic Predictors for Mechanical Failure After Adult Spinal Deformity Surgery: A Retrospective Cohort Study in 138 Patients.

STUDY DESIGN: Retrospective cohort study at a single institution. OBJECTIVE: We aimed at estimating the rate of revision procedures and identify radiographic predictors of mechanical failure after adult spinal deformity surgery. SUMMARY OF BACKGROUND DATA: Mechanical failure rates after adult spinal deformity surgery range 12% to 37% in literature. Although the importance of spinal and spino-pelvic alignment is well documented for surgical outcome and ideal alignment has been proposed as sagittal vertical axis (SVA) < 5 cm, pelvic tilt < 20° and lumbar lordosis (LL) = pelvic incidence ±â€Š9°, the role of radiographic sagittal spine parameters and alignment targets as predictors for mechanical failure remains uncertain. METHODS: A consecutive cohort of adult spinal deformity patients who underwent corrective surgery with at least 5 levels of instrumentation between January 2008 and December 2012 at a single tertiary spine unit were followed for at least 2 years. Time to death or failure was recorded and cause-specific Cox regressions were applied to evaluate predictors for mechanical failure or death. RESULTS: A total of 138 patients with median age of 61 years were included for analysis. Follow up ranged 2.1 to 6.8 years. In total 47% had revision and estimated failure rates were 16% at 1 year increasing to 56% at 5 years. A multivariate analysis adjusting for age at surgery showed increased hazard of failure from LL change > 30°, postoperative TK > 50°, and SS ≤30°. LL change was mostly because of 3-column osteotomy and ending the instrumentation at L5 or S1 increased the hazard of failure more than 6 fold compared with more cranial lumbar levels. CONCLUSION: Mechanical failure rate was 47% after adult spinal deformity corrective surgery. LL change > 30°, postoperative TK > 50°, and postoperative SS ≤30° were independent radiographic predictors associated with increased hazard of failure. LEVEL OF EVIDENCE: 4.

Curve Magnitude in Patients Referred for Evaluation of Adolescent Idiopathic Scoliosis: Five Years' Experience From a System Without School Screening.

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVES: To analyze the referral pattern of patients with adolescent idiopathic scoliosis (AIS) in a tertiary hospital in a nationalized health care system without school screening and to compare curve magnitude on referral with results reported in the literature. SUMMARY OF BACKGROUND DATA: In Denmark, school screening for AIS has not been in effect for more than two decades, and there is limited knowledge of curve magnitude and pattern of referral to specialized treatment in our country. Other studies, however, have assessed the effectiveness of school scoliosis screening. Our tertiary institution receives referrals for evaluation of AIS from general practitioners (GPs) and other hospitals or private specialists. METHOD: A review was conducted on all patients diagnosed with AIS between 2010 and 2015. Data collection included age, gender, menarchal status, recommended treatment, and major curve Cobb angle for all patients aged 10-19 years referred for evaluation of AIS. Major curve magnitude was categorized as 10-19, 20-39, or ≥40 degrees, and the distribution of categories was compared to a screened population reported in the litterature. RESULTS: A total of 166 of 460 newly referred AIS patients were referred from GP. Mean age was 15 years (standard deviation = 2) and median Cobb angle was 35 degrees. Overall, 33% were initially recommended treatment with a brace. This group had a median curve size of 41 degrees, and 28% presented more than 1 year past menarche. We found a significantly larger curve magnitude at the time of referral in our GP cohort compared to a screened population (p < .001), and 22% versus 8% had a Cobb angle >40 degrees (p < .001). CONCLUSION: The present study confirms that in a health care system without school screening, patients with AIS referred for evaluation by GPs have larger curve sizes compared to systems with school screening. LEVEL OF EVIDENCE: III.

Flexibility Predicts Curve Progression in Providence Nighttime Bracing of Patients With Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine treatment outcome with providence brace (PB) and to assess the ability of pretreatment supine lateral bending radiographs (SLBR) in predicting curve progression. SUMMARY OF BACKGROUND DATA: Results from treatment with the PB for adolescent idiopathic ccoliosis (AIS) have been inconsistent and further research is needed. The association between flexibility, as determined by pretreatment SLBR, and curve progression has not previously been examined. METHODS: All patients treated with the PB from 2006 to 2011 who met Scoliosis Research Society (SRS) bracing criteria were included. Flexibility of the curve was determined based on SLBR and radiographic variables were registered at beginning of treatment and at skeletal maturity (SM) or before surgery. An increase in standing Cobb angle by more than 5 degrees was considered progression. Follow-up SRS-22 scores were compared with a control group with minor AIS. Analysis included multiple linear and logistic regression. RESULTS: A total of 63 patients were included. Mean age was 13.3 years (SD: 1.5) and mean standing Cobb angle was 34° (SD: 5°). Radiographic progression was observed in 43% of patients at SM and surgical rate was 27% and 37% at SM and 2-year follow up, respectively. SRS-22 total scores were similar but the mental health score was significantly better in the control group (P = 0.042). Multiple linear regression analysis showed that decreased flexibility adjusted for age, Cobb angle, and menarchal status was significantly associated with curve progression (P < 0.001). Multiple logistic regression analysis showed that a one percent increase in flexibility was associated with a decrease in risk of curve progression ≥6° (odds ratio = 0.95; 95% confidence interval 0.90-0.98; P = 0.013). CONCLUSION: Progression was seen in 43% of AIS patients treated with the PB. Increase in flexibility was independently associated with a decreased risk of progression. LEVEL OF EVIDENCE: 3.

Rod Strain After Pedicle Subtraction Osteotomy: A Biomechanical Study.

Pedicle subtraction osteotomy (PSO) can provide major sagittal correction for adult spinal deformity, sometimes achieving correction greater than 30°. Surgeons have reported failure rates up to 30% within 2 years, increasing to 46% after 4 to 5 years (SDC Figure 1, http://links.lww.com/BRS/B87). Revision following failure is difficult on the patient. PSO has achieved positive outcomes, but when used to correct posture in older patients with spinal deformity and fixed sagittal imbalance, rod breakage often leads to multiple surgical revisions. These complications must be avoided.

Supine Lateral Bending Radiographs Predict the Initial In-brace Correction of the Providence Brace in Patients With Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective, cross-sectional. OBJECTIVE: To determine the initial curve correction of the providence brace (PB) and to determine to what extend the in-brace Cobb angle corresponds to the curve seen on supine lateral bending radiographs (SLBR). SUMMARY OF BACKGROUND DATA: SLBR are used to assess curve flexibility in patients undergoing surgical treatment for adolescent idiopathic scoliosis (AIS). A low rate of in-brace correction (IBC) has been associated with a higher risk of curve progression, but to what extent SLBR can be used to predict IBC before initiating bracing treatment is unknown. METHODS: All patients with AIS treated with the PB from January 1, 2006 to December 31, 2013 with a major curve of 25 to 45 degrees° were included. Cobb angle on SLBR before treatment and on initial standing, in-brace radiograph (IBR) were measured twice for each patient by one observer 30 days apart. Using a repeated measure mixed effect model, mean difference and 95% limits of agreement (LOA) between Cobb angles on each type of radiograph were estimated. Correction index (CI) was calculated as: curve flexibility (%)/curve correction (%). RESULTS: A total of 127 patients were included. Mean long-standing Cobb angle was 35° (SD: 6°), which was reduced to mean 13° (SD: 8) on IBR (P < 0.05). No difference in curve correction between curve types was found when adjusting for flexibility using correction index (P = 0.77). Overall mean difference between SLBR and IBR was 0.2° (LOA ±â€Š10°). Mean difference for thoracic curves was 0.2° (LOA ±â€Š8°), for thoracolumbar/lumbar curves 0.9° (LOA ±â€Š10°) and for double major curves 0.4° (LOA ±â€Š16). CONCLUSION: SLBR provide a close estimation to the expected in-brace correction with a mean difference of less than one degree. SLRB could potentially serve as prognostic parameter for curve progression before initiating brace treatment. LEVEL OF EVIDENCE: 3.

A Uniquely Shaped Rod Improves Curve Correction in Surgical Treatment of Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The aim of this study is to determine the initial curve correction in patients surgically treated for adolescent idiopathic scoliosis (AIS) using either beam-like rods (BRs) or traditional circular rods (CRs). SUMMARY OF BACKGROUND DATA: Posterior fusion using all pedicle screw instrumentation has become the standard for the surgical treatment of AIS. Traditionally, the rod is circular in the cross-sectional plane. Recent biomechanical studies suggest that a beam-like structure of the rod may enhance the stiffness of the construct and thereby possibly improve curve correction. METHODS: Two consecutive series of patients surgically treated for AIS between May 2011 and May 2015 were included in the study. Patients were all treated with an ultralow profile all-pedicle screw implant system. In the first series, conventional 5.5 mm CoCr CR were used, and in the second series, 5.5 mm CoCr BR were used. Antero-posterior and lateral radiographs preoperatively and within seven days after surgery were used to measure the correction obtained. RESULTS: The first 60 patients were operated with CR and the subsequent 69 with BR. There was no statistical difference in age, gender, preoperative curve magnitude, Lenke type, or number of levels instrumented (P = 0.451). Major curve correction was significantly better in the BR group than in the CR group (66 vs. 57%) (P < 0.001). We found no difference in preoperative flexibility, secondary curve correction, sagittal balance, or coronal balance (P > 0.058). A postoperative decrease in thoracic kyphosis was seen with no significant difference between groups. Median T5-T12 change was -7° versus -3° for BR and CR, respectively (P = 0.051). CONCLUSION: A BR design results in a significantly better curve correction than conventional rods, but the difference is moderate and the clinical value is uncertain. LEVEL OF EVIDENCE: 3.