Posterior-only correction of Scheuermann kyphosis using pedicle screws: economical optimization through screw density reduction

A Novel Surgical Indication for Scheuermann's Kyphosis

Scheuermann kyphosis can be treated surgically to restore proper sagittal alignment. Thoracic curves >70° are typically indicated for surgical intervention. However, patients who have reached their natural limit of compensatory lumbar hyperlordosis are at risk of accelerated degeneration. This can be determined by comparing lumbar lordosis on standing neutral radiographs and supine extension radiographs. Minimal additional lordosis in extension compared with neutral, abutment of the spinous processes, or greater lumbar lordosis standing than with attempted extension suggest the patient is maximally compensated. We present a case of an adolescent boy with Scheuermann kyphosis who had reached the limit of his hyperlordosis compensation reserve. He subsequently underwent a T4 to L2 posterior spinal fusion with T7 to T11 Ponte Smith-Petersen grade two osteotomies. He tolerated the procedure well with no intraoperative complications or neuromonitoring changes. The patient has continued to do well and progressed to normal activity at 5-month follow-up.

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.

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.

Surgical Procedures Used for Correction of Scheuermann's Kyphosis: A Meta-Analysis

Objectives

Scheuermann's kyphosis can cause severe back pain and cosmetic disorders to patients. Previous studies on surgical procedure selection for correction of Scheuermann's kyphosis have drawn controversial conclusions. Here, a meta-analysis was performed to figure out a better way between anterior-posterior (AP) combined procedures and posterior-only (PO) procedures.

Methods

We searched PubMed database and Ovid database, as well as Cochrane Library (between January 2009 and December 2020, around recent ten years), for studies reporting Scheuermann's kyphosis correction in an anterior way or a posterior way. Random effects meta-analysis regarding correction degrees and incidence of proximal junctional kyphosis (PJK) was performed.

Results

Finally, 13 unique studies including 586 patients (AP: 300; PO: 286) were identified and included for this meta-analysis. Overall, 6 AP cohorts and 10 PO cohorts were pooled regarding the correction degrees of kyphosis in the analysis, respectively. Pooled correction degrees in AP cohorts were 33.31 (95% CI: 27.48–39.15; I² = 86%, P < 0.001) and in PO cohorts were 31.16 (95% CI: 26.97–35.35; I² = 81.1%, P < 0.001). Comparison of correction between AP and PO cohorts did not indicate any significant difference. Likewise, postoperative PJK incidence showed no difference. Back pain can be caused by both AP and PO procedures, but which causes less pain remains to be conclusive. The PO approach showed less blood loss and shorter surgical duration as compared to the AP approach.

Conclusions

In summary, this meta-analysis shows similar treatment effects between AP and PO procedures in correcting Scheuermann's kyphosis, suggesting the advantage of PO procedures due to less blood loss and surgical duration. However, the postoperative complications PJK and distal junctional kyphosis (DJK) cannot be well concluded due to the limitation of existing data.

Maria Adelaide brace in the management of Scheuermann's Kyphosis

PURPOSE

This prospective observational study aims to assess the MA brace effectiveness in hyperkyphosis correction, focusing also on patients' compliance of bracing and its psychological impact.

METHODS

Patients referring to our spine outpatient department with Scheuermann's kyphosis (SK) from January 2011 to January 2017 were prospectively recruited. Patients were divided into two groups, according to their global thoracic kyphosis (TK): Group-A TK_T0 < 60°, Group-B TK_T0 ≥ 60°. The MA brace was prescribed according to SRS criteria. Full spine X-rays were analyzed at conventional times: at the beginning of treatment (T0), at 6-months follow-up (T1, in-brace X-rays), at the end of treatment (T2) and at 2-year minimum follow-up from bracing removal (T3). At T₀, T₂ and T₃ all the patients were assessed using the Italian Version of the SRS-22 Patient Questionnaire (I-SRS22). Variability between and within-groups was assessed; a p value < 0.05 was considered significant.

RESULTS

192 adolescents (87 girls and 105 boys, mean age 13.1) were recruited. The mean global TK at recruitment was 61.9° ± 11.3°, the mean follow-up time was 57.4 months. A good patients' reported compliance was observed: 84.9% of patients used the brace as scheduled. A mean in-brace correction (in-brace TK_%) of 37.4% was observed and a mean final correction (TK_%T3) of 31.6%. At final follow-up (T3), curve reduction (ΔTK ≤  - 5°) was observed in 60.4% of patients and curve stabilization (- 5° < ΔTK < 5) in 29.7% of patients. At baseline, worse SRS22-mental health (p = 0.023) and self-image mean scores (p = 0.001) were observed in Group-B, compared with Group-A. At the end of treatment (T2), an improvement of all items was observed, wit significantly better improvement of self-image domain in Group-B.

CONCLUSION

The MA brace has shown to be effective in the management of SK; good patients' reported compliance and a positive effect on the patients' mental status were recorded.

Long-Term Surgical Results of Skip Pedicle Screw Fixation for Patients with Adolescent Idiopathic Scoliosis: A Minimum-Ten-Year Follow-Up Study

Skip pedicle screw fixation for adolescent idiopathic scoliosis (AIS) requires fewer screws and can reduce the risk of neurovascular injury as compared with segmental pedicle screw fixation. However, the long-term impact of screw number reduction on correction and clinical results is unclear. This study examined the 10-year post-operative outcomes of skip pedicle screw fixation for patients with AIS. We reviewed the outcomes of 30 patients who underwent skip pedicle screw fixation for AIS. Radiological and clinical findings were assessed before and immediately, 2 years, and 10 years after surgery in the remaining 25 patients. The mean Cobb angle of the main curve preoperatively and immediately, 2 years, and 10 years post-operatively was 59.4°, 23.4°, 25.8°, and 25.60°, respectively, and was significantly improved at all post-surgical time points (all p < 0.001). The mean correction rate immediately after surgery was 60.8%, and the correction loss rate at the observation end point was 4.8%. The Cobb angle of the lumbar curve was significantly improved immediately after surgery, and the correction persisted until 10 years post-operatively. Remarkable gains were observed for most Scoliosis Research Society-22 patient questionnaire sub-scores at the final follow-up versus preoperative assessments. In conclusion, good correction of the AIS deformity by skip pedicle screw fixation was well maintained over a long follow-up period of 10 years, with clinically meaningful gains in Society-22 patient questionnaire sub-scores.

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.

How does the cervical spine respond to hyperkyphosis correction in Scheuermann's disease?

OBJECTIVE

This study aimed to quantify the response of the cervical spine to the surgical correction of Scheuermann's kyphosis (SK) and to postoperative proximal junctional kyphosis (PJK).

METHODS

Fifty-nine patients (mean age 14.6 ± 2.3 years) were enrolled in the study: 35 patients in a thoracic SK (T-SK) group and 24 in a thoracolumbar SK (TL-SK) group. The mean follow-up period was 47.2 ± 17.6 months. Radiographic data, PJK-related complications, and patient-reported outcomes were compared between groups.

RESULTS

The global kyphosis significantly decreased postoperatively, and similar correction rates were observed between the two groups (mean 47.1% ± 8.6% [T-SK] vs 45.8% ± 9.4% [TL-SK], p = 0.585). The cervical lordosis (CL) in the T-SK group notably decreased from 21.4° ± 13.3° to 13.1° ± 12.4° after surgery and was maintained at 14.9° ± 10.7° at the latest follow-up, whereas in the TL-SK group, CL considerably increased from 7.2° ± 10.7° to 11.7° ± 11.1° after surgery and to 13.8° ± 8.9° at the latest follow-up. PJK was identified in 16 patients (27.1%). Its incidence in the TL-SK group was notably higher than it was in the T-SK group (41.6% [n = 10] vs 17.1% [n = 6], p = 0.037). Compared with non-PJK patients, PJK patients had greater CL and lower pain scores on the Scoliosis Research Society-22 questionnaire (p < 0.05).

CONCLUSIONS

Hyperkyphosis correction eventually resulted in reciprocal changes in the cervical spine, with CL notably decreased in the T-SK group but significantly increased in the TL-SK group. Patients developing PJK have increased CL, which seems to have a negative effect on patients' health-related quality of life.

Curve patterns deserve attention when determining the optimal distal fusion level in correction surgery for Scheuermann kyphosis

BACKGROUND CONTEXT

The surgical strategy to decide distal fusion level for Scheuermann kyphosis (SK) is controversial. Some spinal surgeons advocate that instrumentation should end at the first lordotic vertebra (FLV), whereas others recommend extending spinal fusion to the sagittal stable vertebra (SSV). Scheuermann kyphosis has two curve patterns: Scheuermann thoracic kyphosis (STK), with the curve apex above or at T10; and Scheuermann thoracolumbar kyphosis (STLK), with the curve apex below T10. To our knowledge, curve patterns have not been taken into consideration when determining the distal fusion level.

PURPOSE

This study aims to analyze the clinical and radiographic outcomes, including the distal junctional problems, in pediatric patients with STK and STLK who underwent fusion with different distal fusion levels.

STUDY DESIGN

This is a retrospective, single-center, institutional review board-approved study.

PATIENT SAMPLE

A total of 45 consecutive pediatric patients with STK or STLK.

OUTCOME MEASURES

The following parameters were evaluated: global kyphosis (GK), deformity angular ratio (DAR), correction rate of GK and DAR, thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sagittal vertical axis (SVA), T1 pelvic angle (TPA), the distance from the center of the lower instrumented vertebra (LIV) to the posterior sacral vertical line, pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and distal junctional kyphosis (DJK).

METHODS

This work was supported by the National Natural Science Foundation of China (Grant No. 81171672), Nanjing Clinical Medical Center, and Jiangsu Provincial Key Medical Center. Patients with STK were fused to SSV at the distal level (Group STK), whereas patients with STLK were fused to FLV (Group STLK). Whole spine x-rays obtained before surgery, immediately after operation, and at the latest follow-up were evaluated. The radiographic and clinical data were compared between Groups STK and STLK. All patients had a minimum of 2 years of follow-up.

RESULTS

Before surgery, Groups STK and STLK were comparable in terms of age, gender, body mass index, fusion levels, follow-up time, some radiographic parameters and the 22-item Scoliosis Research Society questionnaire (SRS-22) evaluation. DAR and TLK were significantly smaller, whereas PI was significantly greater, in Group STK than those in Group STLK. Despite different distal fusion strategies, STK and STLK were corrected to an equivalent extent, with similar GK, correction rate, LL, SVA, TPA, PT, and SS immediately after operation and at the final follow-up. The DAR and TLK retained were smaller, whereas the PI retained was greater, in Group STK than STLK after surgery. Distal junctional kyphosis complications were found in five patients with STK curve type. In Group STK, patients with DJK were found to have significantly larger preoperative GK (87.5±7.0 vs. 77.5±9.0, p=.024), correction rate of GK (62.9±10.2% vs. 51.3±8.5%, p=.021), and correction rate of DAR (55.9±4.5% vs. 36.6±13.7%, p=.011) than those without DJK. Pre- and postoperative SRS-22 assessments did not show any significant difference between Groups STK and STLK or between patients with and without DJK.

CONCLUSIONS

Curve patterns should be taken into attention when determining the optimal distal fusion level in correction surgery for SK. For patients with STLK, relatively shorter fusion stopping at FLV is enough to correct SK with the preservation of more lumbar motility and less development of DJK. For patients with STK, we suggest extending fusion to the SSV, which could restrict more distal junctional problems than fusion to the FLV. Large GK and correction degree might be the associated factors of developing DJK in STK patients.

What Are the Indications for Spinal Fusion Surgery in Scheuermann Kyphosis?

BACKGROUND

Surgical indications for Scheuermann kyphosis are variable. We sought to evaluate the characteristics of patients undergoing operative versus nonoperative treatment of Scheuermann kyphosis to better understand current practices and the factors which contribute to the decision for surgical management.

METHODS

Multicenter prospective cohort study. We evaluated consecutive patients presenting with Scheuermann kyphosis. Patients underwent either surgical or nonoperative management according to surgeon and patient discretion. Preoperative patient-reported outcome measures (Scoliosis Research Society and Spinal Appearance Questionnaire scores), demographics, and radiographic characteristics were assessed.

RESULTS

Overall, 150 patients with Scheuermann kyphosis were enrolled, with 77 choosing nonoperative treatment and 73 treated operatively. Compared with the nonoperative cohort, patients treated operatively were older (16.3±2.0 vs. 15.1±2.2, P=0.0004), and had higher body mass index (26.3±7.2 vs. 22.7±6.5, P=0.003), had greater T2-T12 kyphosis (71±14 degrees vs. 61±12 degrees, P<0.001), increased pelvic incidence (46 vs. 41 degrees, P=0.03) and pelvic tilt (10 vs. 3 degrees, P=0.03). There was no detected difference in maximal sagittal Cobb angle in the operative versus nonoperative patients (73±11 vs. 70±12 degrees, P=0.11). Functionally, the operative patients had worse Scoliosis Research Society pain scores (3.7±0.9 vs. 4.1±0.7, P=0.0027) and appearance scores (2.9±0.7 vs. 3.4±0.8, P <0.0001).

CONCLUSIONS

Patients undergoing surgical management of Scheuermann disease were more likely to have large body mass index and worse pain scores. Other factors beyond radiographic measurement likely contribute to the decision for surgical management of Scheuermann kyphosis.

LEVEL OF EVIDENCE

Level II.

Severe rigid Scheuermann kyphosis in adult patients; correction with posterior-only approach

PURPOSE

Scheuermann kyphosis is the most common structural kyphosis among adolescence and young people. Surgical treatment may be performed through combined anterior and posterior or posterior-only approaches; to our knowledge, the efficacy of posterior-only approach as less invasive procedure is not well studied in case of severe rigid Scheuermann kyphosis.

MATERIALS AND METHODS

Eighteen patients with severe rigid Scheuermann kyphosis operated through only posterior approach from 2013 to 2016 were evaluated. All information regarding demographic data, curve size before and after the surgery, surgical time, amount of blood loss, correction loss during follow-up and also complications was collected.

RESULT

There were six females and 12 males. Mean age of the patients was 22.4 years (range 17-38). Mean kyphosis angle before surgery was 87.2° (range 85-105), and that reduced to 47.4° (range 45-55) after the surgery. Mean curve size in hyperextension view was 73.8°. Mean postoperative Cobb angle was 50-55 percent of preoperative curves. Mean hospital admission duration was 3.5 days after the index surgery (range 3-5 days). Mean blood loss during the surgery was 250 ml. Mean surgical duration time was 150 min. Mean follow-up period was 9 months (range 8-48 months). No complication was found among the patients.

CONCLUSION

Posterior-only approach using advanced osteotomy techniques and posterior release is a safe and reliable approach for treatment of patients suffering from severe rigid Scheuermann kyphosis and provides acceptable deformity correction.

Adding Satellite Rods to Standard Two-rod Construct With the Use of Duet Screws: An Effective Technique to Improve Surgical Outcomes and Preventing Proximal Junctional Kyphosis in Posterior-Only Correction of Scheuermann Kyphosis

STUDY DESIGN

A retrospective matched-cohort comparative study.

OBJECTIVE

The aim of this study was to compare the surgical results after the use of duet screw based satellite rods and bilateral satellite rods (S-RC) versus a standard two-rod construct (2-RC) across osteotomy sites in a matched cohort with Scheuermann kyphosis (SK).

SUMMARY OF BACKGROUND DATA

Multiple Ponte osteotomies are frequently employed to correct SK via a posterior-only approach, with a 2-RC across the osteotomy sites. Whereas, correction rate and junction problems remain as the major concerns.

METHODS

This study reviewed a consecutive series of patients with SK who had undergone posterior-only correction with multilevel Ponte osteotomy between 2009 and 2014 and had been followed over 24 months. Twenty-two patients receiving placement with an S-RC with the use of duet screws were identified and closely matched with 22 patients with a 2-RC in terms of age, apex, and magnitude of kyphosis. Comparisons were made with regards to deformity magnitude, correction results, complications, and clinical outcomes between the two groups.

RESULTS

No significant difference was found between groups in preoperative patient's factors (age, gender, apex, magnitude of kyphosis, and SRS-22 scores) and surgical factors (blood loss, operation time, osteotomy levels, and fused levels). Compared with the 2-RC group, the S-RC group had higher correction rate (55.4% ± 7.5% vs. 46.2% ± 5.1%, P < 0.001), less correction loss (1.0 ± 0.8° vs. 2.4 ± 1.4°, P < 0.001) during the follow-up, and higher improvement of back pain as well (P < 0.05). None were detected with pseudarthrosis or implant failure in either group, but proximal junctional kyphosis was less frequently seen in S-RC group (1 of 22) than 2-RC group (7 of 22) (P < 0.05).

CONCLUSION

As a safe method, use of S-RC is effective in providing increased kyphotic correction across multiple Ponte osteotomy levels, and improving patient-reported outcomes of management satisfaction and back pain. The biomechanical benefits of stress dispersion, coupled with increased stability and weight bearing ability, make it a powerful technique preventing correction loss and proximal junctional kyphosis.

LEVEL OF EVIDENCE

3.

Posterior-Only Approach with Pedicle Screws for the Correction of Scheuermann's Kyphosis

Study Design

Retrospective study (level of evidence: level 3).

Purpose

The purpose of this study was to evaluate the clinical and radiological results of the posterior-only approach with pedicle screws for the treatment of Scheuermann's kyphosis (SK).

Overview of Literature

The correction of SK with instrumentation can be performed using posterior-only or combined anterior-posterior procedures. With the use of all-pedicle screw constructs in spine surgery, the posterior-only approach has become a popular option for the definitive treatment of SK. In a nationwide study involving 2,796 patients, a trend toward posterior-only fusion with lower complication rates was reported.

Methods

We retrospectively reviewed the data of patients who underwent posterior-only correction for SK between January 2005 and May 2013. Patients with a definite diagnosis of SK who fulfilled the minimum follow-up criterion of 24 months were included. The thoracic kyphosis (T5–T12), lumbar lordosis (L1–S1), and thoracolumbar junction (T10–L2) angles were measured from preoperative, postoperative, and last control radiographs. Sagittal balance, thoracic length, thoracic diameter, Voutsinas index and the sacral slope, pelvic tilt, proximal junction kyphosis, and distal junction kyphosis angles were also measured.

Results

Forty-five patients underwent surgery for the treatment of SK between 2005 and 2013. After applying the exclusion criteria, 20 patients (18 males and 2 females) with a mean age of 19 years were included. The mean thoracic kyphosis angle was 79.8 degrees preoperatively, 44.6 degrees postoperatively, and 44.9 degrees at the last control. There were statistically significant differences between preoperative and postoperative values in the thoracic kyphosis and lumbar lordosis angles, thoracic length, thoracic diameter, and Voutsinas index (p<0.05).

Conclusions

The clinical and radiological results of the current study suggest that posterior-only fusion is an efficient technique for the treatment of SK.

Comparison of low density and high density pedicle screw instrumentation in Lenke 1 adolescent idiopathic scoliosis

BACKGROUND

The correlation between implant density and deformity correction has not yet led to a precise conclusion in adolescent idiopathic scoliosis (AIS). The aim of this study was to evaluate the effects of low density (LD) and high density (HD) pedicle screw instrumentation in terms of the clinical, radiological and Scoliosis Research Society (SRS)-22 outcomes in Lenke 1 AIS.

METHODS

We retrospectively reviewed 62 consecutive Lenke 1 AIS patients who underwent posterior spinal arthrodesis using all-pedicle screw instrumentation with a minimum follow-up of 24 months. The implant density was defined as the number of screws per spinal level fused. Patients were then divided into two groups according to the average implant density for the entire study. The LD group (n = 28) had fewer than 1.61 screws per level, while the HD group (n = 34) had more than 1.61 screws per level. The radiographs were analysed preoperatively, postoperatively and at final follow-up. The perioperative and SRS-22 outcomes were also assessed. Independent sample t tests were used between the two groups.

RESULTS

Comparisons between the two groups showed no significant differences in the correction of the main thoracic curve and thoracic kyphosis, blood transfusion, hospital stay, and SRS-22 scores. Compared with the HD group, there was a decreased operating time (278.4 vs. 331.0 min, p = 0.004) and decreased blood loss (823.6 vs. 1010.9 ml, p = 0.048), pedicle screws needed (15.1 vs. 19.6, p < 0.001), and implant costs ($10,191.0 vs. $13,577.3, p = 0.003) in the LD group.

CONCLUSIONS

Both low density and high density pedicle screw instrumentation achieved satisfactory deformity correction in Lenke 1 AIS patients. However, the operating time and blood loss were reduced, and the implant costs were decreased with the use of low screw density constructs.

Staged Correction of Severe Thoracic Kyphosis in Patients with Multilevel Osteoporotic Vertebral Compression Fractures

Study Design Technical report. Objective Multilevel osteoporotic vertebral compression fractures may lead to considerable thoracic deformity and sagittal imbalance, which may necessitate surgical intervention. Correction of advanced thoracic kyphosis in patients with severe osteoporosis remains challenging, with a high rate of failure. This study describes a surgical technique of staged vertebral augmentation with osteotomies for the treatment of advanced thoracic kyphosis in patients with osteoporotic multilevel vertebral compression fractures. Methods Five patients (average age 62 ± 6 years) with multilevel osteoporotic vertebral compression fractures and severe symptomatic thoracic kyphosis underwent staged vertebral augmentation and surgical correction of their sagittal deformity. Clinical and radiographic outcomes were assessed retrospectively at a mean postoperative follow-up of 34 months. Results Patients' self-reported back pain decreased from 7.2 ± 0.8 to 3.0 ± 0.7 (0 to 10 numerical scale; p < 0.001). Patients' back-related disability decreased from 60 ± 10% to 29 ± 10% (0 to 100% Oswestry Disability Index; p < 0.001). Thoracic kyphosis was corrected from 89 ± 5 degrees to 40 ± 4 degrees (p < 0.001), and the sagittal vertical axis was corrected from 112 ± 83 mm to 38 ± 23 mm (p = 0.058). One patient had cement leakage without subsequent neurologic deficit. Decreased blood pressure was observed in another patient during the cement injection. No correction loss, hardware failure, or neurologic deficiency was seen in the other patients. Conclusion The surgical technique described here, despite its complexity, may offer a safe and effective method for the treatment of advanced thoracic kyphosis in patients with osteoporotic multilevel vertebral compression fractures.

Does surgery for Scheuermann kyphosis influence sagittal spinopelvic parameters?

PURPOSE

To analyze changes in sagittal spinopelvic parameters (SSPs) after surgical treatment of Scheuermann's Kyphosis (SK).

METHODS

We analyzed 20 patients affected by SK and subjected to posterior correction of the kyphosis by facetectomy, Ponte osteotomy, fusion and multilevel instrumentation with pedicle screw system. Four spinal and three pelvic parameters were measured: sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis, lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS) and pelvic tilt (PT). Analysis of changes in postprocedural SSPs compared to preoperative values was performed.

RESULTS

TK passed from 78.6° preoperatively to 45.8° (p = 0.003). LL passed from 74.5° preoperatively to 53.5° (p = 0.01). No significant changes occurred in SVA, SS, PT and PI compared to preoperative values.

CONCLUSION

We confirm the positive effect of surgery by Ponte osteotomy and posterior spinal fusion on TK and LL in patients with SK. In our experience, pelvic parameters did not change after surgery.