Anterior Column Realignment Through Open Pre-posterior Release-Anterior-Posterior Fusion Versus Hybrid Minimally Invasive-Anterior-Posterior Fusion for Dynamic Sagittal Imbalance of the Spine.

STUDY DESIGN: Retrospective comparative study. OBJECTIVES: To investigate the clinical and radiological outcomes after anterior column realignment (ACR) through pre-posterior release-anterior-posterior surgery (PAP) and minimally invasive surgery -lateral lumbar interbody fusion (MIS-LLIF) using hybrid anterior-posterior surgery (AP). METHODS: A total of 91 patients who underwent ACR with long fusions from T10 vertebra to the sacropelvis with a follow-up period of at least 2 years after corrective surgery for adult spinal deformity were included and divided into two groups by surgical method: AP and PAP. AP was performed in 26 and PAP in 65 patients. Clinical outcomes and radiological parameters were investigated and compared. A further comparison was conducted after propensity score matching between the groups. RESULTS: The more increase of LL and decrease of PI-LL mismatch were observed in the PAP group than in the AP group postoperatively. After propensity score matching, total operation time and intraoperative bleeding were greater, and intensive care unit care and rod fracture were more frequent in the PAP group than in the AP group with statistical significance. Reoperation rate was higher in PAP (29.2%) than in AP (16.7%) without statistical significance. CONCLUSIONS: PAP provides a more powerful correction for severe sagittal malalignment than AP procedures. AP results in less intraoperative bleeding, operation time, and postoperative complications. Therefore, this study does not suggest that one treatment is superior to the other. LEVEL OF EVIDENCE: III.

Reoperation depending on time period following pedicle subtraction osteotomy for thoracolumbar kyphosis in patients with ankylosing spondylitis.

OBJECTIVE: The aim of this study was to investigate time-dependent rates and indications of unplanned reoperation and to evaluate the most common indication depending on the time interval after pedicle subtraction osteotomy (PSO) for correction of thoracolumbar kyphosis in patients with ankylosing spondylitis (AS). METHODS: A total of 321 consecutive patients with AS (284 men; mean age 43.8 years) with thoracolumbar kyphosis who underwent PSO were included. Patients who underwent reoperation after the index surgery were divided according to the duration of the follow-up period. RESULTS: A total of 51 patients (15.9%) underwent unplanned reoperations. The reoperation groups had greater preoperative and postoperative C7 sagittal vertical axis (SVA), and less lordotic postoperative osteotomy angle (-4.3° ± 18.6° vs -15.0° ± 13.7°, p < 0.001). The perioperative change in SVA was not significantly different between groups (-10.0 ± 7.1 cm vs -10.0 ± 5.1 cm, p = 0.970), while that in the osteotomy angle was significantly different (-22.4° ± 21.3° vs -30.0° ± 11.5°, p = 0.014). Most reoperations (45.1%; 23/51) were performed within 2 weeks of the initial operation. Within 2 weeks, the most common cause of reoperation was neurological deficit in 10 patients, with a cumulative reoperation rate of 3.2%. After 3 years, the most common complications were mechanical complications in 8 patients, accounting for 15.7% (8/51) of patients. Overall, the most common indications for reoperation were mechanical complications (17 patients; 5.3%), followed by neurological deficits (12 patients; 3.7%). CONCLUSIONS: PSO may be the most effective surgical procedure for the correction of thoracolumbar kyphosis in patients with AS. However, 51 patients (15.9%) required an unplanned reoperation.

Surgical sequence in anterior column realignment with posterior osteotomy is important for degree of adult spinal deformity correction: advantages and indications for posterior to anterior sequence.

BACKGROUND: We hypothesized that posterior osteotomy prior to ACR (Anterior column realignment) through P-A-P surgical sequence would permit a greater correction for deformity corrective surgery than the traditional A-P sequence without posterior osteotomy. This study aimed to determine the impact of the P-A-P sequence on the restoration of lumbar lordosis (LL) compared to the A-P sequence in deformity corrective surgery for adult spinal deformity (ASD) patients and to identify the characteristics of patients who require this sequence.  METHODS: Between 2017 and 2019, 260 ASD patients who had undergone combined corrective surgery were reviewed retrospectively. This study included 178 patients who underwent posterior osteotomy before the ACR (P-A group) and 82 patients who underwent the A-P sequence (A-P group). Sagittal spinopelvic parameters were determined from pre- and postoperative whole-spine radiographs and compared between the groups. To find better indications for the P-A-P sequence, we conducted additional analysis on postoperative outcomes of patients in the A-P group.  RESULTS: The P-A group showed a significantly higher change in LL (53.7° vs. 44.3°, p < 0.001), C7 sagittal vertical axis (C7 SVA: 197.4 mm vs. 146.1 mm, p = 0.021), segmental lordosis (SL) L2/3 (16.2° vs. 14.4°, p = 0.043), SL L3/4 (16.2° vs. 13.8°, p = 0.004), and SL L4/5 (15.1° vs. 11.3°, p = 0.001) compared to the A-P group. At the final follow-up, pelvic incidence (PI) minus LL mismatch (PI - LL mismatch) was significantly higher in the A-P group (13.4° vs. 2.9°, p < 0.001). Stepwise logistic regression analysis showed that age ≥ 75 years (odds ratio [OR] = 2.151; 95% confidence interval [CI], 1.414-3.272; p < 0.001), severe osteoporosis (OR = 2.824; 95% CI, 1.481-5.381; p = 0.002), rigid lumbar curve with dynamic changes in LL < 10° (OR = 5.150; 95% CI, 2.296-11.548; p < 0.001), and severe facet joint osteoarthritis (OR = 4.513; 95% CI, 1.958-10.402; p < 0.001) were independent risk factors for PI - LL mismatch ≥ 10° after A-P surgery. CONCLUSION: P-A-P sequence for deformity corrective surgery in ASD offers greater LL correction than the A-P sequence. Indications for the procedure include patients aged ≥ 75 years, severe osteoporosis, rigid lumbar curve with dynamic change in LL < 10°, or more than four facet joints of Pathria grade 3 in the lumbar region.

Relationship between Sagittal Alignment and Anterior Bony Resorption of Cervical Vertebral Body in Patients with Ankylosing Spondylitis.

STUDY DESIGN: This is a retrospective comparative cohort study. PURPOSE: To investigate the prevalence of anterior resorption of the cervical spine in ankylosing spondylitis (AS) and its relationship with sagittal alignment. OVERVIEW OF LITERATURE: This study believes that no published reports exist regarding the relationship between anterior resorption and spinopelvic alignment. METHODS: This retrospective study included 238 patients with AS who underwent surgical correction for thoracolumbar kyphosis. Of these, 80 patients with complete subaxial ankylosis were selected and divided into two groups: groups 1 (consisting of 28 patients with anterior bony resorption) and 2 (consisting of 52 patients without anterior resorption). Cervical sagittal parameters were analyzed and compared between the two groups. RESULTS: The average lateral diameter measured in patients with C5 anterior resorption was 84.2%±7.8% (62.4%-96.8%). Cervical lordosis was 8.7°±13.4° and 10.9°±11.5° in groups 1 and 2 (p=0.556), respectively. No significant differences were noted between the two groups on spinopelvic alignment in the T1 slope (52.2°±11.1° and 53.3°±9.9° in groups 1 and 2, respectively; p=0.742), C2-C7 sagittal vertical axis (SVA; 6.2±1.7 cm and 6.2±1.8 cm in groups 1 and 2, respectively; p=0.978), C7 SVA (14.3±4.9 cm and 14.6±6.2 cm in groups 1 and 2, respectively; p=0.823), or T1 pelvic angle (27.1°±8.9° and 31.6°±11.2° in groups 1 and 2, respectively; p=0.382). Correlation analyses were significant between the extent of anterior resorption and sagittal parameters, C2-C7 lordosis (R2=-0.428, p=0.021), and T1-T4 kyphosis (R2=-0.375, p=0.045). CONCLUSIONS: Anterior bony resorption could develop by stress concentration. However, the development was not related to the sagittal alignment. The particular segments involved in developing anterior resorption varied, possibly because of their dependence on the preceding pattern of ankylosis.

Improvements in lower-extremity patient-reported outcomes after lumbar interbody fusion.

OBJECTIVE: Recently, new patient-reported outcome measures (PROMs) of the spine were designed to overcome the limitations of previous spinal PROMs and to consider the whole spine as a single kinetic functional unit. Owing to the significance of spine-hip-knee and global body balance, the spine and lower extremities cannot be considered separately. However, no reports have evaluated lower-extremity functional outcome using PROMs after lumbar spine surgery. The authors aimed to elucidate changes in hip and knee PROMs after lumbar interbody fusion and to evaluate the sagittal spinopelvic radiographic parameters that were most strongly correlated with lower-extremity PROMs. METHODS: In 2018, the authors consecutively evaluated patients who underwent lumbar interbody fusion surgery with at most three levels. Preoperative and 1-year postoperative clinical and radiographic data were assessed. Spinal functional outcomes were measured with the Oswestry Disability Index (ODI), visual analog scale (VAS) for pain, and Scoliosis Research Society-22r (SRS-22r) questionnaire. Lower-extremity functional outcomes were evaluated with the Harris Hip Score (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Linear regression was used to evaluate the relationship between spinal and lower-extremity PROMs and spinopelvic radiographic parameters. RESULTS: The authors enrolled 67 patients, with a mean age of 66.4 years. The average number of surgical levels was 1.7. All assessed PROMs improved significantly after surgery (p < 0.001 for ODI, p < 0.001 for VAS, p = 0.017 for SRS-22r, p = 0.042 for HHS, and p = 0.033 for WOMAC). Spinopelvic parameters, including lumbar lordosis (LL), pelvic tilt (PT), C7 sagittal vertical axis, and sagittal radiographic parameters of hip and knee, significantly improved after surgery. On linear regression analysis, HHS and WOMAC correlated with LL and PT, respectively (ß = 0.554 and p = 0.043 for correlation of HHS with LL; ß = 1.573 and p = 0.021 for correlation of WOMAC with PT). CONCLUSIONS: The current study demonstrated that lumbar fusion surgery may induce postoperative improvements in lower-extremity functional and radiological outcomes. However, among radiographic parameters, changes in LL and PT were the most strongly associated with lower-extremity PROMs.

Pedicle Subtraction Osteotomy in Adult Spinal Deformity: Comparing Fixed Versus Flexible Sagittal Imbalance.

STUDY DESIGN/SETTING: Level III-retrospective radiologic and clinical comparative study. OBJECTIVE: This study compares the results of pedicle subtraction osteotomy (PSO) for fixed versus flexible sagittal imbalance in adult spinal deformity. SUMMARY OF BACKGROUND DATA: The result of PSO may be different according to the flexibility of the deformity. METHODS: Sixty-one patients who underwent PSO were enrolled with a minimum 2-year follow-up. Twenty-one patients had fixed imbalance resulting from ankylosing spondylitis and iatrogenic flatback deformity, and 40 patients had flexible imbalance resulting from degenerative spinal deformity and posttraumatic kyphosis. RESULTS: The mean age was 54.9±9.2 years in the fixed group and 65.9±10.5 years in the flexible group (P<0.01). PSO achieved about 35 degrees of correction of kyphotic angle in both groups, but the loss of correction (LOC) was higher in the flexible group. The correction of Lumbar Lordosis was similar in both groups, at 31.7±15.4 degrees in the fixed group and 32.3±20.8 degrees in the flexible group, although the LOC was also higher in the flexible group than in the fixed group, at 9.8±12.4 and 2.7±3.5 degrees, respectively (P<0.01). The sagittal vertical axis was much more restored in the fixed group than in the flexible group (P=0.002). Postoperative complications were identified in 4 patients in the fixed group, consisting of neurological deficit and screw loosening, and in 15 patients in the flexible group, consisting of proximal junctional kyphosis, screw pullout, rod fracture, and pseudarthrosis. CONCLUSIONS: PSO for flexible sagittal imbalance resulted in a higher LOC of the osteotomy angle, Lumbar Lordosis, and sagittal vertical axis relative to the fixed deformity. Furthermore, more complications such as implant failure developed in the flexible group.

Surgical correction for adult spinal deformity increases acetabular lateral coverage of femoral heads.

BACKGROUND: Studies explaining the relationship between hip and spine reported that spinal corrective surgery affected acetabular orientation and changes in pelvic tilt were capable of influencing radiographic measures of acetabular coverage. This study aimed to assess the change in coronal parameters for acetabular coverage as a result of adult spinal deformity (ASD) correction and to analyze the relationship between the postoperative changes in sagittal spinopelvic parameters and coronal acetabular coverage parameters. METHODS: Fifty-two consecutive patients who had undergone multilevel spinal surgical correction were enrolled and evaluated. Coronal acetabular coverage parameters included Tönnis angle (TA), lateral center edge angle (LCEA), and the angle of Sharp (SA). All radiographic parameters were evaluated at the preoperative and the postoperative 1 year. Paired t test was used to determine whether there were significant changes between the time points. Bivariate correlation and linear regression analysis were used to assess the relationship between the postoperative changes of spinal alignment and acetabular orientation. RESULTS: The surgical correction resulted in significant decrease of TA, increase of LCEA and SA, respectively (p < 0.001). The changes in pelvic tilt (PT) demonstrated weak correlation on TA (ß = 0.117, p < 0.001 for right; ß = 0.111, p < 0.001 for left). CONCLUSIONS: Although the surgical correction of ASD significantly changed PT resulting in increased acetabular lateral coverage parameters, the correlation between the changes of PT following sagittal correction of ASD and acetabular coverage parameters was low. TRIAL REGISTRATION: This study was retrospectively registered with approval by the institutional review board (IRB) of our institution (approval number: KHNMC-2020-10-010).

Risk factors for intraoperative endplate injury during minimally-invasive lateral lumbar interbody fusion.

During lateral lumbar interbody fusion (LLIF), unintended intraoperative endplate injury (IEPI) can occur and thereafter lead cage subsidence. The aim of this study was to investigate the incidence of IEPI during LLIF, and its predisposing factors. A retrospective review was conducted on consecutive patients (n = 186; mean age, 70.0 ± 7.6 years) who underwent LLIF at 372 levels. Patient's demographic and surgical data were compared between patients with and without IEPI. Also, the radiographic data of each level were compared between intact and IEPI segments. IEPI was identified at 76 levels (20.4%) in 65 patients. The incidences of IEPI at every 100 consecutive segments were not different. When 372 segments were analyzed independently, sagittal disc angle (DA) in the extended position (4.3° ± 3.6° at IEPI segments vs. 6.4° ± 4.0° at intact segments), the difference between sagittal DA in the extended position and cage angle (- 2.2° ± 4.0° vs. 0.0° ± 3.9°), and the difference between preoperative disc height and cage height (- 5.4 mm ± 2.4 mm vs. - 4.7 mm ± 2.0 mm) were different significantly. Also, endplate sclerosis was more common at intact segments than IEPI segments (33.2% vs. 17.3%). Multivariate analysis showed that male sex (odds ratio [OR] 0.160; 95% confidence interval [CI] 0.036-0.704), endplate sclerosis (OR 3.307; 95% CI 1.450-8.480), and sagittal DA in the extended position (OR 0.674; 95% CI 0.541-0.840) were significant associated factors for IEPI. IEPI was correlated not with surgeon's experience, but with patient factors, such as sex, preoperative disc angle, and endplate sclerosis. Careful surgical procedures should be employed for patients with these predisposing factors.

Extent and characteristic of relationships in canal dimension and canal body ratio between cervical and lumbar spine.

A known prevalence of concurrent cervical and lumbar spinal stenosis was shown to be 5-25%, but there is a lack of evidence regarding direct relationships in canal dimension and canal-body ratio between cervical and lumbar spine. Total 247 patients (mean age: 61 years, male: 135) with cervical and lumbar computed tomography scans were retrospectively reviewed. Midsagittal vertebral body and canal diameters in reconstructed images were measured at all cervical and lumbar vertebrae, and canal-body ratios were calculated. The canal diameter and ratio were also compared according to the gender and age, and correlation analysis was performed for each value. There were significant correlations between cervical (C3-C7) and lumbar (L1-L5) canal dimension (p < 0.001). C5 canal diameter was most significantly correlated with L4 canal diameter (r = 0.435, p < 0.001). Cervical canal-body ratios (C3-C7) were also correlated with those of lumbar spine (L1-L5) (p < 0.001). The canal-body ratio of C3 was most highly correlated with L3 (r = 0.477, p < 0.001). Meanwhile, mean canal-body ratios of C3 and L3 were significantly smaller in male patients than female (p = 0.038 and p < 0.001) and patient's age was inversely correlated with C5 canal diameter (r = - 0.223, p < 0.001) and C3 canal-body ratio (r = - 0.224, p < 0.001). Spinal canal dimension and canal-body ratio have moderate degrees of correlations between cervical and lumbar spine and the elderly male patients show the tendency of small canal diameter and canal-body ratio. This relationship of cervical and lumbar spine can be an important evidence to explain to the patients.

Use of iliac screw associated with more correction of lumbar lordosis than S2-alar-iliac screw for adult spinal deformity.

BACKGROUND: To date, there is a paucity of reports clarifying the change of spinopelvic parameters in patients with adult spinal deformity (ASD) who underwent long segment spinal fusion using iliac screw (IS) and S2-alar-iliac screw (S2AI) fixation. METHODS: A retrospective review of consecutive patients who underwent deformity correction surgery for ASD between 2013 and 2017 was performed. Patients were divided into two groups based on whether IS or S2AI fixation was performed. All radiographic parameters were measured preoperatively, immediately postoperatively, and the last follow-up. Demographics, intraoperative and clinical data were analyzed between the two groups. Additionally, the cohort was subdivided according to the postoperative change in pelvic incidence (PI): subgroup (C) was defined as change in PI ≥5° and subgroup (NC) with change < 5°. In subgroup analyses, the 2 different types of postoperative change of PI were directly compared. RESULTS: A total of 142 patients met inclusion criteria: 111 who received IS and 31 received S2AI fixation. The IS group (65.6 ± 26°, 39.8 ± 13.8°) showed a significantly higher change in lumbar lordosis (LL) and upper lumbar lordosis (ULL) than the S2AI group (54.4 ± 17.9°, 30.3 ± 9.9°) (p < 0.05). In subgroup (C), PI significantly increased from 53° preoperatively to 59° postoperatively at least 50% of IS cohort, with a mean change of 5.8° (p < 0.05). The clinical outcomes at the last follow-up were significantly better in IS group than in S2AI group in terms of VAS scores for back and leg. The occurrence of sacroiliac joint pain and pelvic screw fracture were significantly greater in S2AI group than in IS group (25.8% vs 9%, p < 0.05) and (16.1% vs 3.6%, p < 0.05). CONCLUSIONS: Compared with the S2AI technique, the IS technique usable larger cantilever force demonstrated more correction of lumbar lordosis, and possible increase in pelvic incidence. Further study is warranted to clarify the clinical impaction of these results.

Junctional Failure After Thoracolumbar Kyphosis Correction in Patients with Ankylosing Spondylitis.

OBJECTIVE: We investigated the characteristics and revision rate of junctional failure after surgical correction for thoracolumbar kyphosis in patients with ankylosing spondylitis. METHODS: A total of 230 patients had undergone surgical correction for thoracolumbar kyphosis from 2010 to 2019. The state of ankylosis between the uppermost instrumented vertebra (UIV) and UIV+1 and between the lowermost instrumented vertebra (LIV) and LIV-1 was analyzed using a modified Stoke ankylosing spondylitis spine score. Proximal junctional failure (PJF) and distal junctional failure (DJF) were defined as any type of symptomatic junctional failure. RESULTS: Of the 230 patients, 23 (10.0%) had developed junctional failure. Of these 23 patients, 16 had had partial ankylosis and 7 had had complete ankylosis. PJF had developed in 10 patients and DJF in 13. The most common type of junctional failure was a junctional fracture, which developed in 12 patients. PJF had developed by UIV fracture in 4 patients, UIV+1 fracture in 1 patient, and UIV+2 in 1 patient. DJF had developed by LIV fracture in 6 patients, metallic failure in 5, and progression of DJF in 2 patients. The average time to the development of PJF and DJF was 13 months and 12.4 months, respectively. All 10 patients with PJF and 7 of 13 patients with DJF (53.8%) had required reoperation. Of the 12 patients with junctional fracture, 11 (91.7%) had undergone reoperation. CONCLUSIONS: Of the 23 patients with junctional failure, 16 had had immature ossification of the anterior longitudinal ligament. Therefore, to prevent junctional failure, the state of ankylosis seems to be important for selecting the fusion level after osteotomy. Once junctional failure has developed, however, reoperation should be considered owing to the stress concentration at the UIV or LIV.

Best versus worst surgical outcomes after single-level posterior lumbar interbody fusion for degenerative spondylolisthesis.

PURPOSE: Previous studies have shown conflicting results regarding the factors affecting the clinical outcome after fusion for degenerative spondylolisthesis. However, no study has compared the best and worst clinical outcome groups using patient-reported outcome measures. We aimed to compare the characteristics of patients with best and worst outcomes following single-level lumbar fusion for degenerative spondylolisthesis. METHODS: 200 patients underwent single-level interbody fusion with a minimum 2-years follow-up were included. We excluded patients with surgical complications already-known to be associated with poor postoperative outcomes, including pseudoarthrosis and postoperative infection. According to 2-year postoperative Oswestry disability index scores, patients were divided into two groups; Best and Worst. Demographic, clinical and radiographic variables were compared between the two groups. RESULTS: Compared with patients in the Best group, those in the Worst group were older (59.5 and 67.0 years, respectively; p = 0.012; odds ratio [OR], 1.143; 95% confidence interval [CI], 1.030-1.269) and had a longer duration of pain from onset (2.6 and 7.2 years, respectively; p = 0.041; OR, 1.021; 95% CI, 1.001-1.041). The cutoff value of pain duration from onset was measured as ≥3.5 years on Receiver operating characteristic analysis. Patients in the Worst group had a lower preoperative angular motion compared to those in the Best group (12.7° and 8.3°, respectively; p = 0.016; OR, 0.816; 95% CI, 0.691-0.963). CONCLUSIONS: Degenerative spondylolisthesis patients of good clinical outcome after single-level lumbar interbody fusion were relatively young, had a short symptom duration before surgery, and a high preoperative instability compared with the patient having poor postoperative clinical outcome. Therefore, these findings should be considered preoperatively when deciding the appropriate individual treatment plan.

How does long thoracolumbar realignment surgery of adult spinal kyphotic deformity affect lower extremity compensation? Using full body radiograph.

PURPOSE: By using full body radiograph, the aim of the current study was to elucidate the expected degree of lower extremity compensatory change after long thoracolumbar realignment surgery with adult spinal deformity patient who had normal or only mild osteoarthritis on lower extremities. METHODS: Two novel parameters were used for assessment of regional compensation of the lower extremity. The Pearson correlation test was used to assess the correlation of postoperative changes of lower extremity compensation with the other spinopelvic parameters. RESULTS: Overall, 113 spinal deformity patients (mean age was 54.5 years) were recruited and the average number of fused vertebrae was 13.3 ± 3.5. Except pelvic tilt (PT), postoperative sacrum-femur angle (SF) changes showed only moderate correlation with all angular spinopelvic parameters (r = 0.323-0.374; p < .001 to p = .001). Also C7 sagittal vertical axis showed no significant correlation with SF (p = .584-.621). However, postoperative changes of sagittal femur-tibia angle (SFT) reported strong correlation with all parameters evaluated (r = 0.455-0.586; p < .001 to p = .046). CONCLUSION: For adult spinal deformity patients who had normal or only mild osteoarthritis on the lower extremities underwent long thoracolumbar realignment surgery, the surgeon could expect improvement of compensatory change of the knee with correction of spinopelvic parameters. However, the degree of hip compensation improvement was relatively difficult to predict than that of the knee, except PT.

Impact of growth hormone treatment on scoliosis development and progression: analysis of 1128 patients with idiopathic short stature.

OBJECTIVES: The purpose of this study was to evaluate the impact of recombinant human growth hormone (rhGH) on the development and progression of scoliosis in patients with idiopathic short stature (ISS). METHODS: Patients with ISS who underwent rhGH treatment from 1997 to 2017 and were followed up for scoliosis screening with serial radiographic examination were included. For assessing scoliosis development, patients who did not have scoliosis at the time of rhGH treatment were included and followed up to determine whether de novo scoliosis developed during the treatment. For evaluating scoliosis progression, patients who already had scoliosis were analyzed. Univariate and multivariate Cox regression analyses of demographic and radiographic variables were performed to determine the related factors in the development and progression of scoliosis. RESULTS: For assessing scoliosis development, 1093 patients were included. The average duration of rhGH treatment was about 2 years. De novo scoliosis developed in 32 patients (3.7%). The analysis revealed that sex (p=0.016) and chronological age (p=0.048) were statistically significant factors associated with scoliosis development. However, no relationship was observed between scoliosis development and rhGH treatment types or duration. Among 67 patients who already had scoliosis at the time of rhGH treatment, 11 (16.4%) showed scoliosis progression. However, the rhGH types and duration also did not affect scoliosis progression. CONCLUSIONS: De novo scoliosis developed in 3.7% and scoliosis progressed in 16.4% of the patients during rhGH treatment. However, scoliosis development or progression was not affected by the types or duration of rhGH treatment in patients with ISS.

Radiographic and clinical evidence: osteoarthritic knee can change surgical result for lumbar degenerative disease patient undergone surgery for 3-year follow-up: a retrospective comparative clinical study.

BACKGROUND: There is a paucity of reports clarifying the implication of knee osteoarthritis (OA) on spinal sagittal alignment of patients undergone surgery for lumbar spine. This study aimed to analyze how osteoarthritic knee affects radiographic and clinical results of degenerative lumbar disease patients undergone lumbar fusion. METHODS: We retrospectively reviewed the medical records and radiographs of 74 consecutive degenerative lumbar disease patients who underwent posterior instrumentation and fusion surgery between May 2016 and June 2017 and were followed up for minimum 3 years postoperatively. The patients were divided into 2 groups according to the severity of knee OA by Kellgren-Lawrence grading (KLG) scale (group I, KLG 1 or 2 [n = 39]; group II, KLG 3 or 4 [n = 35]). Patient demographic data, comorbidities, spinal sagittal parameters and clinical scores were extracted and compared at preoperative, postoperative 1 month and the ultimate follow-up between the groups. In radiographic assessment, sagittal alignment parameters and sagittal balance were used. In clinical assessment, the scores of Oswestry disability index (ODI) and Scoliosis Research Society questionnaire (SRS-22) were used. For the frequency analysis of categorical variables across the groups, chi-square test was used and student t tests was used to compare the differences of continuous variables. RESULTS: In radiographic assessment, TLK (thoracolumbar kyphosis), LL (lumbar lordosis), PT (pelvic tilt), C7 SVA (sagittal vertical axis) in both groups improved significantly after surgery (p <  0.05). However, LL, PT, C7SVA improved at postoperative 1 month in the group II were not maintained at the ultimate postoperative follow-up. In clinical assessment, preoperative Oswestry disability index (ODI, %) and all SRS-22 subscores of the group I and II were not different (p > 0.05). There were significant differences between the groups at the ultimate follow-up in ODI (- 25.6 vs - 12.1, p <  0.001), SRS total score (%) (28 vs 20, p = 0.037), function subscore (1.4 vs 0.7, p = 0.016), and satisfaction subscore (1.6 vs 0.6, p < 0.001). CONCLUSION: Osteoarthritic knee with KLG 3 or 4 have a negative influence on maintaining postoperative spinal sagittal alignment, balance, and the clinical outcomes achieved immediately by posterior instrumentation and fusion for lumbar degenerative disease. TRIAL REGISTRATION: This study was retrospectively registered with approval by the institutional review board (IRB) of our institution (approval number: 2018-11-007).

Radiographic findings for surgery-related complications after pedicle subtraction osteotomy for thoracolumbar kyphosis in 230 patients with ankylosing spondylitis.

OBJECTIVE: The purpose of this study was to investigate the rate of and the risk factors for surgery-related complications demonstrated on radiography after pedicle subtraction osteotomy (PSO) for thoracolumbar kyphosis in patients with ankylosing spondylitis (AS). METHODS: The authors retrospectively reviewed the medical records of 230 consecutive patients with thoracolumbar kyphosis due to AS who had undergone 1-level PSO at a single institution in the period from 2010 to 2017. The causes of surgery-related complications were divided into two types: surgical/technical failure and mechanical failure. RESULTS: The patients consisted of 20 women and 210 men, with an average age of 43.4 years. The average follow-up period was 39.0 months. The preoperative sagittal vertical axis was 18.5 ± 69.3 cm, which improved to 4.9 ± 4.6 cm after PSO. Of the 77 patients (33.5%) who experienced minor or major surgery-related complications, 56 had complications related to surgical/technical failure (overall incidence 24.3%) and 21 had complications related to mechanical failure (overall incidence 9.1%). Fourteen patients (6.1%) underwent reoperation. However, among the 77 patients with complications, the rate of revision surgery was 18.2%. The most common radiological complications were as follows: sagittal translation in 24 patients, coronal imbalance in 20, under-correction in 8, delayed union in 8, and distal junctional failure and kyphosis in 8. The most common causes of reoperation were coronal imbalance in 4 patients, symptomatic malposition of pedicle screws in 3, and distal junctional failure in 3. Delayed union was statistically correlated with posterior sagittal translation (p = 0.007). CONCLUSIONS: PSO can provide acceptable radiographic outcomes for the correction of thoracolumbar kyphosis in patients with AS. However, a high incidence of surgery-related complications related to mechanical failure and surgical technique can develop. Thorough radiographic investigation before and during surgery is needed to determine whether complete ossification occurs along the anterior and posterior longitudinal ligaments of the spine.

Instrumented surgical treatment for metastatic spinal tumors: is fusion necessary?

OBJECTIVE: The goal of this study was to evaluate the radiographic and clinical results of instrumentation surgery without fusion for metastases to the spine. METHODS: Between 2010 and 2017, patients with spinal tumors who underwent instrumentation without fusion surgery were consecutively evaluated. Preoperative and postoperative clinical data were evaluated. Data were inclusive for last follow-up and just prior to death if the patient died. Instrumentation-related complications included screw migration, screw or rod breakage, cage migration, and screw loosening. RESULTS: Excluding patients who died within 6 months, a total of 136 patients (140 operations) were recruited. The average follow-up duration was 16.5 months (median 12.4 months). The pain visual analog scale score decreased from 6.4 to 2.5 (p < 0.001) and the Eastern Cooperative Oncology Group scale score improved (p < 0.001). There were only 3 cases (2.1%) of symptomatic instrumentation-related complications that resulted in revisions. There were 6 cases of nonsymptomatic complications. The most common complication was screw migration or pull-out (5 cases). There were 3 cases of screw or rod breakage and 1 case of cage migration. Two-thirds of the cases of instrumentation-related complications occurred after 6 months, with a mean postoperative period of 1 year. CONCLUSIONS: The current study reported successful outcomes with very low complication rates after nonfusion surgery for patients with spinal metastases, even among those who survived for more than 6 months. More than half of the instrumentation-related complications were asymptomatic and did not require revision. The results suggest that nonfusion surgery might be sufficient for a majority of patients with spinal metastases.

Outcomes of Non-Operative Management for Pseudarthrosis after Pedicle Subtraction Osteotomies at Minimum 5 Years Follow-Up.

OBJECTIVE: Minimal data exist regarding non-operative management of suspected pseudarthrosis after pedicle subtraction osteotomy (PSO). This study reports radiographic and clinical outcomes of non-operative management for post-PSO pseudarthrosis at a minimum 5 years post-detection. METHODS: Nineteen consecutive patients with implant breakage indicating probable pseudarthrosis after PSO surgery (13 women/ six men; mean age at surgery, 58 years) without severe pain and disability were treated with non-operative management (mean follow-up, 5.8 years; range, 5-10 years). Non-operative management included medication, intermittent brace wearing and avoidance of excessive back strain. Radiographic and clinical outcomes analysis was performed. RESULTS: Sagittal vertical axis (SVA), proximal junctional angle, thoracic kyphosis achieved by a PSO were maintained after detection of pseudarthrosis through ultimate follow-up. Lumbar lordosis and PSO angle decreased at final follow-up. There was no significant change in Oswestry Disability Index (ODI) scores and Scoliosis Research Society (SRS) total score, or subscales of pain, self-image, function, satisfaction and mental health between detection of pseudarthrosis and ultimate follow-up. SVA greater than 11 cm showed poorer ODI and SRS total score, as well as the pain, self-image, and function subscales (p<0.05). CONCLUSION: Non-operative management of implant failure of probable pseudarthrosis after PSO offers acceptable outcomes even at 5 years after detection of implant breakage, provided SVA is maintained. As SVA increased, outcome scores decreased in this patient population.

Novel radiographic parameters for the assessment of total body sagittal alignment in adult spinal deformity patients.

OBJECTIVE: In this study, the authors' goal was to develop and validate novel radiographic parameters that better describe total body sagittal alignment (TBSA). METHODS: One hundred sixty-six consecutive operative spinal deformity patients were evaluated using full-body stereoradiographic imaging. Seven TBSA parameters were measured and then correlated to 6 commonly used spinopelvic measurements. TBSA measures consisted of 4 distance measures relating the cranial center of mass (CCOM) to the sacrum, hips, knees, and ankles, and 3 angular measures relating the CCOM to the hips, knees, and ankles. Furthermore, each TBSA parameter was correlated to patient-reported outcome (PRO) scores using the Oswestry Disability Index (ODI) and Scoliosis Research Society-22 (SRS-22) instruments. Thirty patients were randomly selected for inter- and intraobserver reliability testing of the TBSA parameters using intraclass correlation coefficients (ICCs). RESULTS: All TBSA radiographic parameters demonstrated strong linear correlation with the currently accepted primary measure of sagittal balance, the C7 sagittal vertical axis (r = 0.55-0.96, p < 0.001). Moreover, 5 of 7 TBSA measures correlated strongly with ODI and SRS-22 total scores (r = 0.42-0.51, p < 0.001). Inter- and intraobserver reliability for all TBSA measures was good to excellent (interrater ICC = 0.70-0.98, intrarater ICC = 0.77-1.0). CONCLUSIONS: In spine deformity patients, novel TBSA radiographic parameters correlated well with PROs and with currently utilized spinal sagittal measurements. Inter- and intrarater reliability was high for these novel parameters. This is the first study to propose a reliable method for measuring head-to-toe global spinal alignment.

Relationship between facet joint tropism and degeneration of facet joints and intervertebral discs based on a histological study.

PURPOSE: Evaluate the correlation between lumbar facet joint tropism, lumbar facet joint degeneration, and intervertebral disc degeneration. METHODS: Forty-two of facet joints were evaluated histologically and radiologically. RESULTS: The correlation between facet joint tropism and histologic, CT, and MRI grading was -0.159 (P = 0.339), 0.025 (P = 0.226) and -0.270 (P = 0.102), respectively. The correlation between facet joint tropism and intervertebral disc MRI grading was 0.346 (P = 0.033), and that between facet joint and intervertebral disc MRI grading was 0.208 (P = 0.210). CONCLUSIONS: Facet joint tropism was correlated with intervertebral disc degeneration but not with facet joint degeneration.