Surgical correction of Scheuermann's kyphosis

How to determine the optimal proximal fusion level for Scheuermann kyphosis

OBJECTIVE

To determine optimal proximal fusion levels for instrumented spinal fusion for Scheuermann kyphosis.

METHODS

We reviewed 86 patients (33 women) who underwent corrective instrumented spinal fusion for Scheuermann kyphosis. All patients had long-cassette upright lateral radiographs taken preoperatively, postoperatively, and at 2 years and the last follow-up. Demographic, radiographic, and surgical parameters were compared between patients with and without PJK.

RESULTS

PJK occurred in 28 patients (32%). The mean maximum Cobb angle was 85.8° ± 11.7° preoperatively, 54.8° ± 14.2° postoperatively, and 59.7° ± 16.8° at the last follow-up. Age and sex did not differ between the PJK and non-PJK groups (P > 0.05). The preoperative curve characteristics, fusion levels, and corrective ratio were similar in both groups (P > 0.05). The maximal Cobb angle at 2 years and the last follow-up significantly differed between the 2 groups (P < 0.05). The proportion of patients with the uppermost instrumented vertebra (UIV) at or above the proximal end vertebra (PEV) was similar in both groups (P > 0.05). The proportion of patients with UIV at or above T2 was significantly greater in the non-PJK group (P < 0.05). PJK was significantly associated with a C7 plumb line (C7PL)-sacrum distance ≥ 50 mm (P < 0.05).

CONCLUSION

PJK is the main cause of postoperative correction loss. Proper fusion-level selection can reduce PJK occurrence. We recommend having the UIV at T2 or above, especially when the C7PL-sacrum distance ≥ 50 mm.

Compensation from mild and severe cases of early proximal junctional kyphosis may manifest as progressive cervical deformity at two year follow-up

BACKGROUND

Postoperative reciprocal changes (RC) in the cervical spine associated with varying factors of proximal junctional kyphosis (PJK) following fusions of the thoracopelvic spine are poorly understood.

PURPOSE

Explore reciprocal changes in the cervical spine associated with varying factors (severity, progression, patient age) of PJK in patients undergoing adult spinal deformity (ASD) correction.

PATIENTS AND METHODS

Retrospective review of a multicenter ASD database.

INCLUSION

ASD patients > 18 y/o, undergoing fusions from the thoracic spine (UIV: T6-T12) to the pelvis with two-year radiographic data. ASD was defined as: Coronal Cobb angle ≥ 20°, Sagittal Vertical Axis ≥ 5 cm, Pelvic Tilt ≥ 25°, and/or Thoracic Kyphosis ≥ 60°. PJK was defined as a ≥ 10° measure of the sagittal Cobb angle between the inferior endplate of the UIV and the superior endplate of the UIV + 2. Patients were grouped by mild (M; 10°-20°) and severe (S; > 20°) PJK at one year. Propensity Score Matching (PSM) controlled for CCI, age, PI and UIV. Unpaired and paired t test analyses determined difference between RC parameters and change between time points. Pearson bi-variate correlations analyzed associations between RC parameters (T4-T12, TS-CL, cSVA, C2-Slope, and T1-Slope) and PJK descriptors.

RESULTS

284 ASD patients (UIV: T6: 1.1%; T7: 0.7%; T8: 4.6%; T9: 9.9%; T10: 58.8%; T11: 19.4%; T12: 5.6%) were studied. PJK analysis consisted of 182 patients (Mild = 91 and Severe = 91). Significant difference between M and S groups were observed in T4-T12 Δ1Y(- 16.8 v - 22.8, P = 0.001), TS-CLΔ1Y(- 0.6 v 2.8, P = 0.037), cSVAΔ1Y(- 1.8 v 1.9, P = 0.032), and C2 slopeΔ1Y(- 1.6 v 2.3, P = 0.022). By two years post-op, all changes in cervical alignment parameters were similar between mild and severe groups. Correlation between age and cSVAΔ1Y(R = 0.153, P = 0.034) was found. Incidence of severe PJK was found to correlate with TS-CLΔ1Y(R = 0.142, P = 0.049), cSVAΔ1Y(R = 0.171, P = 0.018), C2SΔ1Y(R = 0.148, P = 0.040), and T1SΔ2Y(R = 0.256, P = 0.003).

CONCLUSIONS

Compensation within the cervical spine differed between individuals with mild and severe PJK at one year postoperatively. However, similar levels of pathologic change in cervical alignment parameters were seen by two years, highlighting the progression of cervical compensation due to mild PJK over time. These findings provide greater evidence for the development of cervical deformity in individuals presenting with proximal junctional kyphosis.

Long-term results of surgical correction of Scheuermann’s kyphosis

Objective. To analyze long-term results of surgical correction of kyphosis due to Scheuermann’s disease.

Material and Methods. Design: retrospective cohort study. The study group included 43 patients (m/f ratio, 34/9). The mean age was 19.1 (14–32) years; the mean postoperative follow-up was 6 ± 10 (5–20) years. Two-stage surgery including discectomy and interbody fusion followed by posterior correction and fusion was conducted in 35 cases (Group A). Eight patients (Group B) underwent only posterior correction and spinal fusion. The following parameters were determined for each patient: thoracic kyphosis (TK), lumbar lordosis (LL) (scoliotic deformity of the thoracic/thoracolumbar spine, if the curve magnitude was > 5°), sagittal vertical axis (SVA), sagittal stable vertebra (SSV), first lordotic vertebra (FLV), proximal junctional angle (PJA) and distal junctional angle (DJA). All measurements were performed immediately before surgery, one week after surgery, and at the end of the follow-up period. All patients answered the SRS-24 questionnaire after surgery and at end of the follow-up period.

Results. Groups were comparable in terms of age and gender of patients, body mass index and initial Cobb angle (p < 0.05). The curve decreased from 77.8° to 40.7° in Group A and from 81.7° to 41.6° in Group B. The loss of correction was 9.1° and 6.0° in groups A and B, respectively. The parameters of lumbar lordosis remained normal during the follow-up period. At implant density less than 1.2, deformity correction and correction loss were 44.5° (54.7 %) and 3.9°, respectively (p < 0.05). Proximal junctional kyphosis (PJK) was detected in 21 out of 43 patients (48.8 %). The frequency of PJK was 45.4 % among patients whose upper end vertebra was included in the fusion and 60 % among those whose upper end vertebra was not included. PJK developed in eight (47.8 %) out of 17 patients with kyphosis correction ≥ 50 % and in 13 (50.0 %) of those with correction < 50 %. The rate of DJK development was 39.5 %. The lower instrumented vertebra (LIV) was located proximal to the sagittal stable vertebra in 16 cases, with 12 (75 %) of them being diagnosed with DJK. In 27 patients, LIV was located either at the SSV level or distal to it, the number of DJK cases was 5 (18.5 %); p < 0.05. Only two patients with complications required unplanned interventions. According to the patient questionnaires, the surgical outcome score increases between the immediate and long-term postoperative periods for all domains and from 88.4 to 91.4 in total. The same applies to answer to the question about consent to surgical treatment on the same conditions: positive answers increased from 82 to 86 %.

Conclusions. Two-stage surgery, as a more difficult and prolonged one, has no advantages over one-stage operation in terms of correction magnitude and stability of the achieved effect. Surgical treatment improves the quality of life of patients with Scheuermann’s disease, and the improvement continues in the long-term postoperative period.

Scheuermann's kyphosis: update on pathophysiology and surgical treatment

Scheuermann's Kyphosis (SK) is a rigid spinal kyphosis. Several theories have been proposed concerning its pathogenesis, but it is, to this day, still unknown. It has a prevalence of 0.4-8.3% in the population with a higher incidence in females. Clinical examination with x-rays is needed to differentiate and confirm this diagnosis. Non-surgical management is reserved for smaller deformities and in skeletally immature patients, whereas surgery is recommended for higher deformities. Combined anterior and posterior approach was considered the gold standard for the surgical treatment of this disease, but there is an increasing trend toward posterior-only approaches especially with use of segmental fixation. This study reviews the pathophysiology of SK while proposing a treatment algorithm for its management.

Long-term outcome after surgical treatment of Scheuermann's Kyphosis (SK)

STUDY DESIGN

A retrospective observational cohort study with a minimum follow-up of 10 years of patients who underwent surgery for Scheurmann Kyphosis (SK).

OBJECTIVE

Evaluate the long-term clinical and radiological outcome of patients with SK who either underwent combined anterior-posterior surgery or posterior instrumented fusion alone. There is paucity of literature for long-term outcome studies on SK. The current trend is towards only posterior (PSF) surgical correction for SK. The combined strategy of anterior release, fusion and posterior spinal fusion (AF/PSF) for kyphosis correction has become historic relic. Long-term outcome studies comparing the two procedures are lacking in literature.

METHODS

51 patients (30 M: 21F) who underwent surgery for SK at a single centre were reviewed. Nineteen had posterior instrumentation alone (PSF) (Group 1) and 32 underwent combined anterior release, fusion with posterior instrumentation (AF/PSF) (Group 2). The clinical data included age at surgery, gender, flexibility of spine, instrumented spinal levels, use of cages and morcellised rib grafts (in cases where anterior release was done), posterior osteotomies and instrumentation, complications and indications for revision surgery. Preoperative flexibility was determined by hyperextension radiographs. The radiological indices were evaluated in the pre-operative, 2-year post-operative and final follow-up [Thoracic Kyphosis (TK), Lumbar lordosis (LL), Voustinas index (VI), Sacral inclination (SI) and Sagittal vertical axis (SVA)]. The loss of correction and incidence of JK (Junctional Kyphosis) and its relation to fusion levels were assessed. Complications and difference in outcome between the two groups were analyzed.

RESULTS

The mean age at surgery for 51 patients was 20.6 years who were followed up for a minimum of 10 years (mean: 14 years; range 10-16 years). The mean age was 18.5 ± 2.2 years and 21.9 ± 4.8 years in groups 1 and 2, respectively. The mean pre- and 2-year post-operative ODIs were 32.6 ± 12.8 and 8.4 ± 5.4, respectively, in group 1 (p < 0.0001) and 30.7 ± 11.7 and 6.4 ± 5.7, respectively, in group 2 (p < 0.0001). The final SRS-22 scores in group 1 and 2 were 4.1 ± 0.4 and 4.0 ± 0.35, respectively (p = 0.88). The preoperative flexibility index was 49.2 ± 4.2 and 43 ± 5.6 in groups 1 and 2, respectively (p < 0.0001). The mean TKs were 81.4° ± 3.8° and 86.1° ± 6.0° for groups 1 and 2, respectively, which corrected to 45.1° ± 2.6° and 47.3° ± 4.8°, respectively, at final follow-up (p < 0.0001). The mean pre-operative LL angle was 60.0° ± 5.0° and 62.4° ± 7.6° in groups 1 and 2, respectively, which at final follow-up was 45.1° ± 4.4° and 48.1° ± 4.8°, respectively (p < 0.0001). The mean pre-operative and final follow-up Voustinas index (VI) in group 1 were 22.9 ± 2.9 and 11.2 ± 1.2, respectively, and in group 2 was 25.9 ± 3.5 and 14.0 ± 2.3, respectively. The mean pre-operative and final follow-up SI angle were 43.6° ± 3.3° and 31.2° ± 2.5° in group 1, respectively, and 44.3° ± 3.5° and 32.1° ± 3.5° in group 2, respectively (p < 0.0001). The pre-operative and final follow-up SVA in group 1 were - 3.3 ± 1.0 cms and - 1.3 ± 0.5 cms, respectively, and in group 2 was - 4.0 ± 1.3cms and - 1.9 ± 1.1cms, respectively (p < 0.0001). Though the magnitude of curve correction in the groups 1 and 2 was significant 36° vs 39° (p = 0.05), there was no significant difference in correction between the two groups. Proximal JK was seen in seven and distal JK in five patients were observed in the whole cohort.

CONCLUSION

The long-term clinical outcomes for both PSF and AF/PSF are comparable with reproducible results. No difference was noted in loss of correction and outcome scores between the two groups. The correction of thoracic kyphosis (TK) had a good correlation with ODI. AF/PSF had much higher complications than PSF group. The objective of correcting the sagittal profile and balancing the whole spinal segment on the pelvis can be achieved through single posterior approach with fewer complications.

Selection of the optimal distal fusion level for Scheuermann kyphosis with different curve patterns: when can we stop above the sagittal stable vertebra?

PURPOSE

To investigate the optimal lowest instrumented vertebra (LIV) in the treatment of Scheuermann kyphosis (SK) with different curve patterns.

METHODS

Fifty-two SK patients who underwent posterior surgery between January 2010 and December 2017 with a minimum follow-up of 2 years were retrospectively reviewed. Patients were divided into two groups based on the curve pattern: the Scheuermann thoracic kyphosis (STK group) or Scheuermann thoracolumbar kyphosis (STLK group). Based on the relationship between the sagittal stable vertebra (SSV) and LIV, both groups were further divided into the SSV group and SSV-1 group. Radiographic parameters, distal junctional kyphosis (DJK) incidence and SRS-22 questionnaire scores were evaluated.

RESULTS

In STK and STLK groups, there were no significant differences in most pre- and postoperative radiographic assessments between SSV and SSV-1 subgroups. DJK incidence showed no significant differences between groups during follow-up (P > 0.05). LIV-PSVL was significantly more negative in the SSV-1 group than that in the SSV group (P < 0.001). Within the SSV-1 group, patients with DJK showed a more negative LIV-PSVL (P = 0.039). Moderate correlation was observed between preoperative LIV-PSVL and DJK with a Spearman coefficient of - 0.474 (P = 0.035). Receiver operative characteristic curve analysis showed that the threshold value of preoperative LIV-PSVL to predict DJK was - 37.35 mm (area under the curve 0.882).

CONCLUSION

Shorter fusion stopping at SSV-1 achieved comparable clinical outcomes and did not increase the risk of DJK for both STK and STLK patients. For patients whose preoperative LIV-PSVL <  - 37.35 mm, extending fusion to SSV is an acceptable solution to prevent DJK.

Sagittal Plane Alignment and Functional Outcomes Following Surgery for Scheuermann Kyphosis

Objective  To evaluate and correlate the pelvic parameters, the sagittal balance (SB), and the functional outcome of the patients submitted to surgical treatment for Scheuermann hyperkyphosis (SK).

Methods  Patients submitted to surgery between January 2005 and December 2016 were included. The following radiographic measurements were obtained: thoracic kyphosis (TK); lumbar lordosis (LL); SB; pelvic incidence (PI); pelvic tilt (PT); and sacral slope (SS). Complications during the follow-up period were recorded.

Results  A total of 19 patients were included (16 males): the mean preoperative kyphosis was of 83°, and the postoperative kyphosis was of 57°. The mean preoperative lumbar lordosis was of 66°, with a postoperative spontaneous correction of 47°. Regarding the preoperative pelvic parameters, the average PI, PT and SS were of 48°,10° and 39° respectively. In the postoperative period, these values were of 50°, 16° and 35° respectively. The preoperative SB was neutral, and it was maintained after the surgical correction. Concerning complications during the follow-up period, three junctional kyphosis were observed–two requiring revision surgery, one nonunion, and one dehiscence of the surgical wound. Regarding the functional results, the average score on the Scoliosis Research Society-22 (SRS-22) patient questionnaire was of 4.04, and we verified that the SB obtained in the postoperative period had no influence on the functional outcome ( p  = 0.125) nor on the postoperative LL ( p  = 0.851).

Conclusion  We verified a spontaneous improvement in the lumbar hyperlordosis at levels not included in the fusion after correction of the TK. Although the postoperative functional results were globally high, we did not find any statistically significant relationship with TK nor LLs. high PI is associated with a greater rate of complications regarding the proximal junctional kyphosis (PJK), and these pelvic parameters should be considered at the time of the SK surgical treatment.

Posterior-only versus combined anterior-posterior fusion in Scheuermann disease: a systematic review and meta-analysis

OBJECTIVE

Combined anterior-posterior (AP) surgery is considered the gold standard for surgical treatment of Scheuermann kyphosis. There are trends toward posterior-only (PO) surgery for correcting this deformity because of the availability of multisegmental compression instruments and posterior shortening osteotomy. To date, surgical strategies for Scheuermann kyphosis remain controversial. The purpose of this study was to compare various surgical approaches for the treatment of Scheuermann kyphosis, including radiological correction and intraoperative outcomes, using a systematic review and meta-analysis.

METHODS

A comprehensive database search of PubMed, EMBASE, Web of Science, and Cochrane Library was performed to identify studies concerning Scheuermann kyphosis. The inclusion criteria were direct comparisons between AP and PO surgeries for Scheuermann kyphosis and assessment of the angle of thoracic kyphosis preoperatively and postoperatively. The authors used the principles of a cumulative meta-analysis by updating the pooled estimate of the treatment effect.

RESULTS

Data from 13 studies involving 1147 participants (542 patients in the AP group and 605 patients in the PO group) were included. The average age was 18.2 years for the AP and 17.9 years for the PO group. The overall mean difference of changes in thoracic kyphosis angles between the AP and PO surgeries was 0.23° (95% CI -2.24° to 2.71°). In studies in which posterior shortening osteotomies were not performed, PO surgery resulted in a significantly low degree of correction of thoracic kyphosis, with a mean difference of 5.59° (95% CI 0.34°-10.83°). Studies in which osteotomies were performed revealed that the angle of correction for PO surgery was comparable to that of AP surgery. Regardless of fixation methods, PO surgical approaches achieved comparable angles.

CONCLUSIONS

PO surgery using posterior osteotomies can achieve correction of Scheuermann kyphosis as successfully as AP surgery does. Reflecting the advancement of surgical technology, large prospective studies are necessary to identify the proper treatments for Scheuermann kyphosis.

Treatment approaches for Scheuermann kyphosis: a systematic review of historic and current management

OBJECTIVE

Scheuermann kyphosis (SK) is an idiopathic kyphosis characterized by anterior wedging of ≥ 5° at 3 contiguous vertebrae managed with either nonoperative or operative treatment. Nonoperative treatment typically employs bracing, while operative treatment is performed with either a combined anterior-posterior fusion or posterior-only approach. Current evidence for these approaches has largely been derived from retrospective case series or focused reviews. Consequently, no consensus exists regarding optimal management strategies for patients afflicted with this condition. In this study, the authors systematically review the literature on SK with respect to indications for treatment, complications of treatment, differences in correction and loss of correction, and changes in treatment over time.

METHODS

Using PubMed, Embase, CINAHL, Web of Science, and the Cochrane Library, all full-text publications on the operative and nonoperative treatment for SK in the peer-reviewed English-language literature between 1950 and 2017 were screened. Inclusion criteria involved fully published, peer-reviewed, retrospective or prospective studies of the primary medical literature. Studies were excluded if they did not provide clinical outcomes and statistics specific to SK, described fewer than 2 patients, or discussed results in nonhuman models. Variables extracted included treatment indications and methodology, maximum pretreatment kyphosis, immediate posttreatment kyphosis, kyphosis at last follow-up, year of treatment, and complications of treatment.

RESULTS

Of 659 unique studies, 45 met our inclusion criteria, covering 1829 unique patients. Indications for intervention were pain, deformity, failure of nonoperative treatment, and neural impairment. Among operatively treated patients, the most common complications were hardware failure and proximal or distal junctional kyphosis. Combined anterior-posterior procedures were additionally associated with neural, pulmonary, and cardiovascular complications. Posterior-only approaches offered superior correction compared to combined anterior-posterior fusion; both groups provided greater correction than bracing. Loss of correction was similar across operative approaches, and all were superior to bracing. Cross-sectional analysis suggested that surgeons have shifted from anterior-posterior to posterior-only approaches over the past two decades.

CONCLUSIONS

The data indicate that for patients with SK, surgery affords superior correction and maintenance of correction relative to bracing. Posterior-only fusion may provide greater correction and similar loss of correction compared to anterior-posterior approaches along with a smaller complication profile. This posterior-only approach has concomitantly gained popularity over the combined anterior-posterior approach in recent years.

Adolescent spine patients have an increased incidence of acetabular overcoverage

Changes in spino-pelvic alignment can lead to changes in acetabular coverage and predispose those with spinal pathologies to hip pathologies. The purpose of this study was to define the incidence of acetabular overcoverage in pediatric spine patients. Retrospective review of charts and EOS radiographs was conducted for patients ≤21 years old with adolescent idiopathic scoliosis (AIS) or Scheuermann’s Kyphosis (SK) who were treated with posterior spinal fusion (PSF) between 12/01/2015–7/26/2016. Radiographs were measured for lateral center edge angles (LCEA), anterior center edge angle (ACEA), and lumbar lordosis pre- and postoperatively. 32 patients met inclusion criteria. Preoperatively, mean LCEA was 44.1 degrees (range: 32–55, SD: 5.1) on the right and 42.8 degrees (range: 33–52, SD: 4.4) on the left. Mean preoperative ACEA was 56.0 degrees (range: 35–90, SD: 10.4). Mean preoperative lordosis was 56.0 degrees (range: −22–105, SD: 19.1) Preoperative LCEA was not associated with lordosis (right: r = 0.002, p = 0.78, left: r = 0.006, p = 0.66). Preoperative ACEA was no associated with lordosis (r = 0.02, p = 0.49). Overall, the mean percent change in LCEA was −3.4% (range: −19.6–21.9, SD: 10.3) on the right and −3.5% (range: −31.0–27.9, SD: 13.3) on the left. Mean percent change in ACEA was 9.1% (range: −20.6–35.7, SD: 15.1). Mean percent change in lordosis was −12.2% (range: −150–33.3, SD: 33.3. The incidence of acetabular overcoverage may be significantly higher in a pediatric spinal population than the general population. Careful monitoring of these patients for signs and symptoms of hip pathology may be warranted.

Selection Of The Optimal Level Of Distal Fixation For Correction Of Scheuermann's Hyperkyphosis

OBJECTIVE

To analyze the efficacy of the method for selecting the distal level of fusion in treatment of thoracic hyperkyphosis in patients with Scheuermann's disease.

BACKGROUND

The fusion area needs to include all the kyphotic deformity in Scheuermann patients; however, precise levels of the distal fixation have not been determined yet.

STUDY DESIGN

Retrospective cohort review.

MATERIALS AND METHODS

Thirty-six patients were operated in the Department of Children and Adolescent Spine Pathology between 2007 and 2010. These patients were divided into two groups: in group I (n = 29) a lower instrumented vertebra corresponded to the sagittal stable one and in group II (n = 7) - this vertebra located proximally.

RESULTS

The mean preoperative kyphosis was 79.3° ± 11.6°, the postoperative - 40.6° ± 11.9° (correction of 49.9%), loss of correction was 4.9° ± 7.0°. Sagittal balance changed from -0.3 ± 3.2 cm before surgery to -1.7 ± 2.1 cm after surgery. Distal junctional kyphosis developed in 1 case (4%) in Group I, and in 5 cases (71%) in Group II.

CONCLUSION

A distal level of instrumentation ending at the first lordotic vertebra is not justified and causes violation of sagittal balance and development of distal junctional kyphosis. The inclusion of a sagittal stable vertebra in fusion prevents the development of this undesirable situation.

Ponte osteotomies in thoracic deformities

Thoracic hyperkyphosis is a sagittal deformity that can cause back pain and neurological impairment, leading to difficulties in maintaining a straight gaze. Sagittal thoracic malalignment has different etiologies and different corrective strategies. An adequate preoperative planning is mandatory to address correctly the surgical treatment, using an appropriate sagittal deformities classification and the rules that relate pelvic parameters to spine curvatures to determine the correction needed to restore a good sagittal alignment. Ponte osteotomies are performed in long non-angular hyperkyphotic thoracic deformities, even if idiopathic scoliosis, rigid deformities or proximal junctional kyphosis after instrumented fusions can benefit from the application of this technique that requires a mobile anterior column for the correction of the deformity. Ponte's is, together with Smith-Petersen osteotomy, a posterior column osteotomy. The magnitude of correction can reach 10° per level if intervertebral discs are still mobile.

Surgical treatment of Scheuermann's kyphosis using a combined antero-posterior strategy and pedicle screw constructs: efficacy, radiographic and clinical outcomes in 111 cases

INTRODUCTION

There is sparse literature on how best to correct Scheuermann's kyphosis (SK). The efficacy of a combined strategy with anterior release and posterior fusion (AR/PSF) with regard to correction rate and outcome is yet to be determined.

MATERIALS AND METHODS

A review of a consecutive series of SK patients treated with AR/PSF using pedicle screw-rod systems was performed. Assessment of demographics, complications, surgical parameters and radiographs including flexibility and correction measures, proximal junctional kyphosis angle (JKA + 1) and spino-pelvic parameters was performed, focusing on the impact of curve flexibility on correction and clinical outcomes.

RESULTS

111 patients were eligible with a mean age of 23 years, follow-up of 24 months and an average of eight levels fused. Cobb angle at fusion level was 68° preoperatively and 37° postoperatively. Flexibility on traction films was 34 % and correction rate 47 %. Postoperative and follow-up Cobb angles were highly correlated with preoperative bending films (r = 0.7, p < 0.05). Screw density rate was 87 %, with increased correction with higher screw density (p < 0.001, r = 0.4). Patients with an increased junctional kyphosis angle (JKA + 1) were at higher risk of revision surgery (p = 0.049). 22 patients sustained complication, and 21 patients had revision surgery. 42 patients with ≥24 months follow-up were assessed for clinical outcomes (follow-up rate for clinical measures was 38 %). This subgroup showed no significant differences regarding baseline parameters as compared to the whole group. Median approach-related morbidity (ArM) was 8.0 %, SRS-sum score was 4.0, and ODI was 4 %. There was a significant negative correlation between the SRS-24 self-image scores and the number of segments fused (r = -0.5, p < 0.05). Patients with additional surgery had decreased clinical outcomes (SRS-24 scores, p = 0.004, ArM, p = 0.0008, and ODI, p = 0.0004).

CONCLUSION

The study highlighted that AR/PSF is an efficient strategy providing reliable results in a large single-center series. Results confirmed that flexibility was the decisive measure when comparing surgical outcomes with different treatment strategies. Findings indicated that changes at the proximal junctional level were impacted by individual spino-pelvic morphology and determined by the individually predetermined thoracolumbar curvature and sagittal balance. Results stressed that in SK correction, reconstruction of a physiologic alignment is decisive to achieving good clinical outcomes and avoiding complications.

[Current concepts on Scheuermann kyphosis: clinical presentation, diagnosis and controversies around treatment]

Scheuermann kyphosis is a structural deformity of the thoracic or thoracolumbar spine that develops prior to puberty and deteriorates during adolescence. There is limited information on its natural history but many patients are expected to have a benign course. Severe kyphosis can progress into adult life and cause significant deformity and debilitating back pain. Conservative treatment includes bracing and physical therapy, but although widely prescribed they have not been scientifically validated. Surgical treatment may be considered in the presence of a progressive kyphosis producing severe pain resistant to conservative measures, neurological compromise, or unacceptable deformity. This is associated with significant risks of major complications that should be discussed with the patients and their families. Modern techniques allow better correction of the deformity through posterior-only surgery with lower complication rates. Simultaneous shortening of the posterior vertebral column across the apical levels, along with spinal cord monitoring, reduces the risk of neurological deficits.

Correção da cifose de Scheuermann: estudo comparativo da fixação híbrida com ganchos e parafusos versus fixação apenas com parafusos

OBJETIVOS: avaliar o grau de correção da cifose de Scheuermann, em 6 pacientes que se submeteram à instrumentação híbrida composta por ganchos e parafusos (H) e 17 fixados apenas com parafusos (P). MÉTODOS: 23 pacientes, com cifose de Scheuermann, submetidos a tratamento cirúrgico por dupla via com início pela via anterior, seguido pela via posterior. Do conjunto de pacientes, 6 foram operados com fixação híbrida e 17 com uso exclusivo de parafusos pediculares. O tratamento cirúrgico foi indicado para cifose rígida, variando de 60º e 105º e portadores do sinal de Risser acima de 4. RESULTADOS: observou-se, no Grupo H, cifose pré-operatória média de 84,17º e no pós-operatório de 47,5º. No Grupo P, a média de cifose no pré-operatório era de 80,35º e, no pós-operatório, de 33,53º. CONCLUSÃO: concluiu-se que os dois tipos de fixação apresentaram resultados muito satisfatórios, contudo, sendo ainda superior quando fixados só com parafusos.

Selection of the optimal distal fusion level in posterior instrumentation and fusion for thoracic hyperkyphosis: the sagittal stable vertebra concept

STUDY DESIGN

Retrospective study.

OBJECTIVE

To determine the appropriate distal fusion level in posterior instrumentation and fusion for thoracic hyperkyphosis by investigating the relationship between the sagittal stable vertebra ([SSV]-the most proximal lumbar vertebral body touched by the vertical line from the posterior-superior corner of the sacrum), first lordotic vertebra (just caudal to the first lordotic disc), and selected lowest instrumented vertebra (LIV).

SUMMARY OF BACKGROUND DATA

It has been recommended that the distal end vertebra and the first lordotic disc beyond the transitional zone distally be included in distal fusion for thoracic hyperkyphosis; however, we have seen distal junctional breakdown even when these rules have been followed.

METHODS

Thirty-one patients (mean age: 18 years, range: 13-38) who underwent long posterior instrumentation and fusion for thoracic hyperkyphosis with a minimum 2-year follow-up were reviewed. Preoperative diagnoses included Scheuermann kyphosis (n = 29), post-traumatic kyphosis (n = 1), and postlaminectomy kyphosis (n = 1). According to the distal fusion level, patients were divided into 2 groups. Group I (n = 24): LIV included the SSV; group II (n = 7): the LIV was proximal to the SSV. Patients were evaluated using standing radiographs and chart review.

RESULTS

Preoperative mean thoracic kyphosis was 86.6 +/- 8.5 degrees and 53.0 +/- 10.4 degrees at final follow-up with a correction rate of 39%. Preoperative average sagittal balance was slightly negative (-0.24 +/- 3.8 cm), and became slightly more negative (-1.33 +/- 2.8 cm) by final follow-up. There were no statistical differences in thoracic kyphosis between the 2 groups. However, there was a statistically significant difference with group II having a more posterior translation of the center of the LIV from the posterior sacral vertical line before surgery and at final follow-up (P = 0.003). In group I, distal junctional problems developed in 2 of 24 (8%) patients and in group II, problems occurred in 5 of 7 (71%) patients (P < 0.05). Despite extending the fusion to the first lordotic vertebra, distal junctional problems developed in 3 of 8 (38%) patients.

CONCLUSION

The distal end of a fusion for thoracic hyperkyphosis should include the SSV. Levels that include the first lordotic vertebra but not the SSV are not always appropriate to prevent postoperative distal junctional kyphosis.

Influence of lumbar lordosis restoration on thoracic curve and sagittal position in lumbar degenerative kyphosis patients

STUDY DESIGN

A retrospective study.

OBJECTIVES

To determine postsurgical correlations between thoracic and lumbar sagittal curves in lumbar degenerative kyphosis (LDK) and to determine predictability of spontaneous correction of thoracic curve and sacral angle after surgical restoration of lumbar lordosis and fusion.

SUMMARY OF BACKGROUND DATA

To our knowledge, there are only a limited number of articles about the relationship between thoracic and lumbar curve in sagittal thoracic compensated LDK.

METHODS

Retrospective review of 53 consecutive patients treated with combined anterior and posterior spinal arthrodesis. We included patients with sagittal thoracic compensated LDK caused by sagittal imbalance in this study. Total lumbar lordosis, thoracic kyphosis, sacral slope, and C7 plumb line were measured on the pre- and postoperative whole spine lateral views. Postoperative changes in thoracic kyphosis, sacral slope, and C7 plumb line according to the surgical lumbar lordosis restoration were measured and evaluated.

RESULTS

The mean preoperative sagittal imbalance by plumb line was 78.3 mm (+/-76.5); this improved to 13.6 mm (+/-25) after surgery (P < 0.0001). Mean lumbar lordosis was 9.4 degrees (+/-19.2) before surgery and increased to 38.4 degrees (+/-13.1) at follow-up (P < 0.0001). Mean thoracic kyphosis was 1.1 degrees (+/-12.7) before surgery and increased to 17.6 degrees (+/-12.2) at follow-up (P < 0.0001). Significant preoperative correlations existed between kyphosis and lordosis (r = 0.772, P < 0.0001) and between lordosis and sacral slope (r = 0.785, P < 0.0001). Postoperative lumbar lordosis is correlated to thoracic kyphosis increase (r = 0.620, P < 0.0001). Postoperative lumbar lordosis is correlated to sacral slope increase (r = 0.722, P < 0.0001).

CONCLUSION

Reciprocal relationship exists between lumbar lordosis and thoracic kyphosis in sagittal thoracic compensated LDK. Surgical restoration of lumbar lordosis for LDK brings about high level of statistical correlation to thoracic kyphosis improvement. At the same time, the reciprocal relationship is maintained.

CAN PATIENTS WITH SAGITTALLY WELL-COMPENSATED LUMBAR DEGENERATIVE KYPHOSIS BENEFIT FROM SURGICAL TREATMENT FOR INTRACTABLE BACK PAIN?

OBJECTIVE

To analyze pre- and postoperative x-rays of sagittal spines and to review the surgical results of 21 patients with lumbar degenerative kyphosis whose spines were sagittally well compensated by compensatory mechanisms but who continued to suffer from intractable back pain

METHODS

We performed a retrospective review of 21 patients treated with combined anterior and posterior spinal arthrodesis. Inclusion criteria were: lumbar degenerative kyphosis patients with intractable back pain and whose spines were sagittally well compensated by a compensatory mechanism, defined as a C7 plumb line to the posterior aspect of the L5–S1 disc of less than 5 cm. Outcome variables included: radiographic measures of preoperative, postoperative, and follow-up films; clinical assessment using the mean Numeric Rating Scale, Oswestry Disability Index, and Patient Satisfaction Index; and a review of postoperative complications.

RESULTS

All patients were female (mean age, 64.5 years; age range, 50–74 years). The mean preoperative sagittal imbalance was 19.5 (± 17.6) mm, which improved to −15.8 (± 22.2) mm after surgery. Mean lumbar lordosis was 13.2 degrees (± 15.3) before surgery and increased to 38.1 degrees (± 14.4) at follow-up (P &lt; 0.0001). Mean thoracic kyphosis was 5.5 degrees (± 10.2) before surgery and increased to 18.9 degrees (± 12.4) at follow-up (P &lt; 0.0001). Mean sacral slopes were 12.9 degrees (± 11.1) before surgery and increased to 26.3 degrees (± 9.6) at follow-up (P &lt; 0.0001). The mean Numeric Rating Scale score improved from 7.8 (back pain) and 8.1 (leg pain) before surgery to 3.0 (back pain) and 2.6 (leg pain) after surgery (P &lt; 0.0001). The mean Oswestry Disability Index scores improved from 56.2% before surgery to 36.7% after surgery (P &lt; 0.0001). In 18 (85.5%) of 21 patients, satisfactory outcomes were demonstrated by the time of the last follow-up assessment.

CONCLUSION

This study shows that even lumbar degenerative kyphosis patients with spines that are sagittally well compensated by compensatory mechanisms may suffer from intractable back pain and that these patients can be treated effectively by the restoration of lumbar lordosis.

MULTIPLE SEGMENTAL OSTEOTOMIES TO THE KYPHOSIS CORRECTION

OBJECTIVE

To evaluate the results of the surgical treatment of the spinal Kyphosis using the Ponte's technique (multiple posterior osteotomies).

METHODS

Ten patients (8 with Scheuermann's kyphosis and 2 with kyphosis after laminectomy) submitted to surgical correction of kyphotic deformity greater than 70° were retrospectively assessed. The age at the surgical time ranged from 12 to 20 years old (mean age16.8 years ± 2.89). The radiographic parameters evaluated were the kyphosis, the lordosis and the scoliosis - whenever present. The presence of proximal and distal junctional kyphosis, loss of correction, and complications as implants loosening and breakage were also assessed. The radiographic parameters were evaluated at the preoperative, early postoperative and late postoperative time.

RESULTS

The patients were followed through a period that ranged from 24 to 144 months (65.8 ±39.92). The mean value of the kyphosis was 78.8° ± 7.59° (Cobb) before surgery and 47.5° ± 12.54° at late follow up, with mean correction of 33.9° ± 9.53° and lost correction of 2.2°.

CONCLUSION

The surgical treatment of the thoracic kyphosis using multiples posterior osteotomies presented a good correction of the deformity and minimal lost of correction during follow up.

Lumbar degenerative kyphosis: radiologic analysis and classifications

STUDY DESIGN

Retrospective study of a consecutive patient series.

OBJECTIVES

To review the radiographic classification of patients with sagittal imbalance due to lumbar degenerative kyphosis (LDK) and to determine correlation between thoracic and lumbar curve.

SUMMARY OF BACKGROUND DATA

Lumbar degenerative kyphosis is one of the common spinal deformities in Asian countries, especially Korea and Japan. However, there have been few studies regarding the classification and treatment of this disease.

METHODS

Seventy-eight patients with LDK were analyzed and classified according to the standing lateral whole spine findings. Total lumbar lordosis (L1-S1), thoracic kyphosis (T5-T12), sacral slope, thoracolumbar angle (T11-L1), and sagittal vertical axis (SVA) were measured on the lateral view of the whole spine. Spinal curve deformities were classified into 2 groups according to the thoracolumbar (T-L) junction angle: flat or lordotic angle (Group 1; N = 53) and kyphotic angle (Group 2; N = 25).

RESULTS

In Group 1, significant correlations between the thoracic and lumbar curves (r = 0.772, P < 0.0001), and between the lumbar curve and sacral slope (r = 0.785, P < 0.0001) were observed. By this result, Group 1 was classified as sagittal thoracic compensated group. In contrast, In Group 2, no correlation was found between the thoracic and lumbar curves in the decompensated group (r = 0.179, P = 0.391), but we found a significant correlation between lordosis and sacral slope (r = 0.442, P = 0.027). By this result, Group 2 was classified as sagittal thoracic decompensated group. There was significant difference in SVA between 2 groups (P = 0.020).

CONCLUSION

The angle of the thoracolumbar junction is an important parameter in determining whether a sagittal thoracic compensatory mechanism exists in LDK. We assumed that existence of a compensatory mechanism in the proximal spine is central to the determination of the fusion levels in the treatment of LDK.

Changes in sagittal alignment after restoration of lower lumbar lordosis in patients with degenerative flat back syndrome

OBJECT

The authors investigate the correlation between thoracic and lumbar curves in patients with degenerative flat back syndrome, and demonstrate the predictability of spontaneous correction of the thoracic curve and sacral angle after surgical restoration of lower lumbar lordosis.

METHODS

The cases of 28 patients treated with combined anterior and posterior spinal arthrodesis were retrospectively reviewed. Inclusion criteria included loss of lower lumbar lordosis resulting in sagittal imbalance. Total lumbar lordosis, thoracic kyphosis, sacral slope, and C-7 plumb line length were measured on pre- and postoperative lateral views of the whole spine. Postoperative changes in thoracic kyphosis, sacral slope, and length of the C-7 plumb line were measured and evaluated according to extent of lumbar lordosis restoration.

RESULTS

The mean (+/- standard deviation) preoperative sagittal imbalance was 64.6 +/- 63.2 mm, which improved to 15.8 +/- 20.7 mm after surgery (p < 0.0001). The preoperative mean lumbar lordosis was 15.6 +/- 14.1 degrees, which increased to 40.3 +/- 14.5 degrees at follow-up (p < 0.0001). The preoperative mean thoracic kyphosis was 1.6 +/- 10.5 degrees and increased to 17.2 +/- 12.5 degrees at follow-up (p < 0.0001). Significant preoperative correlations existed between kyphosis and lordosis (r = 0.628, p = 0.0003), and between lordosis and sacral slope (r = 0.647, p = 0.0002). Postoperative correlations also existed between kyphosis and lordosis (r = 0.718, p < 0.0001 and r = 0.690, p < 0.0001, respectively).

CONCLUSIONS

Lower lumbar lordosis plays an important role in sagittal alignment and balance. Surgical restoration of lumbar lordosis results in predictable spontaneous correction of the thoracic curve and sacral slope in patients with degenerative flat back syndrome.

Predictable correction of the unfused lumbar lordosis after thoracic correction and fusion in Scheuermann kyphosis

STUDY DESIGN

A retrospective examination of preoperative and postoperative radiographs of the sagittal spine of 30 patients with Scheuermann kyphosis.

OBJECTIVES

To determine significant correlations between kyphosis and lordosis in Scheuermann kyphosis, determine predictability of spontaneous sagittal lordosis correction after thoracic correction and fusion, and understand better the biomechanics of the spine.

SUMMARY OF BACKGROUND DATA

Previous studies described relations between kyphosis and lordosis in healthy people. To our knowledge, no relationships, have been described between kyphosis and lordosis in Scheuermann kyphosis.

METHODS

On radiographs, maximum kyphosis, maximum lordosis, sacral slope and L5-S1 angle were measured in the preoperative and postoperative standing lateral radiographs of the spine, and correlations were calculated.

RESULTS

Preoperative significant correlations were present between kyphosis and lordosis (R = 0.421; P = 0.021), and between lordosis and sacral slope (R = 0.824; P < 0001). Postoperative correlations were stronger (R = 0.591; P = 0.001 and R = 0.844; P < 0.001). The percentage of correction of kyphosis was correlated with the percentage of spontaneous decrease of lordosis (R = 0.593; P < 0.001). A negative correlation between L5-S1 angle and upper lumbar segment of lordosis was found before and after surgery.

CONCLUSIONS

This study shows a significant correlation between kyphosis and lordosis before and after surgery. Surgical correction of thoracic hyperkyphosis gives a predictable spontaneous decrease of lumbar lordosis. Correction of lordosis occurs mainly in the upper segment of lumbar lordosis.

Hypotension-induced loss of intraoperative monitoring data during surgical correction of scheuermann kyphosis: a case report

STUDY DESIGN

Presentation of a case report of Scheuermann kyphosis surgical correction.

OBJECTIVE

To describe a scenario where both neurogenic mixed evoked potentials and somatosensory-evoked potentials were lost due solely to hypotension before any correction of a kyphotic spinal deformity was performed.

SUMMARY OF BACKGROUND DATA

Multimodality intraoperative neurophysiologic monitoring of the spinal cord has become widely utilized during surgical correction of scoliotic and kyphotic deformities. Most spinal surgeries also benefit from a state of hypotension to minimize blood loss, but unchecked and persistent hypotension may lead to inadequate perfusion to the spinal cord, resulting in spinal cord dysfunction noted by diminution of neuromonitoring data.

METHODS

An 18-year-old boy with a 95 degrees Scheuermann kyphosis underwent a posterior spinal fusion for correction of his deformity. Intraoperative neurophysiologic monitoring consisting of neurogenic mixed evoked potentials and somatosensory-evoked potentials were performed throughout surgery.

RESULTS

After placement of segmental pedicle screw fixation points and multiple osteotomies, before any instrumented correction of the deformity, all lower extremity neuromonitoring data were acutely lost. The surgeon was immediately warned of the data loss, with the mean arterial pressure noted to be 50 mm Hg. The mean arterial pressure was raised with the use of epinephrine bolus and dopamine infusion. Subsequently, all lower extremity neuromonitoring data returned. A Stagnara wake-up test was performed, which the patient passed, and the surgical correction was performed with his pressure maintained on a dopamine infusion. He awakened without neurologic deficits and had an uneventful recovery.

CONCLUSIONS

Although a state of mild hypotension may be beneficial to limit blood loss during spinal deformity corrective surgery, acute and/or prolonged hypotension may jeopardize spinal cord vascularity and should be avoided especially during surgical treatment of high-risk deformities such as kyphosis. Early warning by multimodality physiologic neuromonitoring appears to be a useful method to alert surgeons of the potentially devastating problem of hypotension-induced spinal cord dysfunction and allows immediate corrective actions.