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

Is sagittal spinopelvic alignment a cause of low back pain in pediatric spine pathologies? A review

Purpose

Altered spinopelvic morphology is observed in many spine pathologies occurring during growth. The aim of the study is to better understand the sagittal compensatory mechanisms and their possible influence on the occurrence of pain in selected pediatric spine pathologies.

Methods

A bibliographic search in the PubMed database included articles published between September 1965 and July 2023. The keywords contained in the search were "spondylolysis," "spondylolisthesis," "scoliosis," "kypho," "sagittal," "pediatric," "child," "adolescent," "grow," "development," and "pain."

Results

The largest diversity in sagittal alignment patterns was reported in idiopathic scoliosis, with global flattening of the spine being the most common. Kyphotic deformations occurring during growth are characterized by structural thoracic or thoracolumbar kyphosis compensated by lumbar hyperlordosis and lower pelvic incidence. Whereas in spondylolisthesis, altered morphology of the spinopelvic junction with high values of pelvic incidence is observed. Pain does not seem to be related to sagittal alignment in idiopathic scoliosis. In Scheuermann disease, it is localized at the apex of the deformity and is associated with the curve pattern, whereas in spondylolisthesis, sagittal alignment correlates with pain scores only in high-grade slips.

Conclusion

Most of the patients with spine disorders that occurred during growth present a clinically balanced posture in the sagittal plane. It suggests that compensatory mechanisms before achieving skeletal maturity are really significant. A comprehension of sagittal alignment in spine deformities and its relationship to pain is essential for the proper assessment and treatment of these disorders.

Scheuermann Kyphosis: Current Concepts and Management

PURPOSE OF REVIEW

Scheuermann's kyphosis (SK) is a developmental deformity of the spine that affects up to 8% of children in the US. Although, the natural progression of SK is noted to be gradual over years, severe deformity can be associated with significant morbidity. Thorough clinical examination and interpretation of relevant imaging help differentiate and confirm this diagnosis. Treatment includes both operative and nonoperative approaches. The purpose of this article is to provide an updated overview of the current theories of its pathogenesis, as well as the principles of diagnosis and treatment of SK.

RECENT FINDINGS

Although a definitive, unified theory continues to be elusive, numerous reports in the past decade provide insight into the pathophysiology of SK. These include alterations in mechanical stress and/or hormonal disturbances. Candidate genes have also been identified to be linked to the inheritance of SK. Updates to nonoperative treatment include the effectiveness of dedicated exercise programs, as well as the types and duration of orthotic treatment. Advances in surgical technique can be observed with a trend toward a posterior-only approach, with supporting evidence for careful evaluation of both the sagittal and coronal planes to determine fusion levels in order to avoid postoperative junctional pathologies. SK is an important cause of structural or rigid kyphosis. It can lead to significant morbidity in severe cases. Treatment is based on curve magnitude and symptoms. Nonoperative treatment consists of physical therapy in symptomatic patients, and bracing can be added for skeletally mature patients. Operative management can be considered in patients with large, progressive, and symptomatic deformity. Future studies can benefit from a focused investigation into patient-reported outcomes after undergoing appropriate treatment.

Effect of the type of brace on head to pelvis sagittal alignment of adolescents with Scheuermann's kyphosis

The aim of this study was to determine the effects of the Milwaukee brace and thoracolumbosacral orthosis (TLSO) on head to pelvis sagittal alignment in adolescents with Scheuermann's kyphosis (SK). A total of 52 adolescents with SK who were under brace treatment were studied. They underwent biplanar radiography of the head to pelvis (EOS Imaging, Paris, France) before and 6 months after the beginning of bracing. We measured T1 slope, neck tilt (NT), cervical sagittal vertical axis (cSVA), thoracic inlet angle (TIA), C0-C2 lordosis, C2-C7 lordosis, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sagittal vertical axis (SVA) and T1 spinopelvic inclination (T1SPi). There were no significant differences in baseline values of TIA, PT, SS, PI, SVA, TK, cSVA, NT and T1 slope between the two groups (p > 0.05). There were significant differences between the baseline and final measurements of T1 slope, cSVA, TK, LL, T1SPi and TIA in both groups (p < 0.05). The results imply that brace treatment can significantly affect head to pelvis sagittal parameters of adolescents with SK. However, there are no significant differences in the values of head to pelvis sagittal parameters when comparing short-term effect of TLSO and the Milwaukee brace.

Sagittal Spinal Alignment in People with Chronic Spinal Cord Injury and Normal Individual: A Comparison Study Using 3D Ultrasound Imaging

The aim of this study was to compare the sagittal spinal alignment of people with chronic spinal cord injury (SCI) with normal individuals and to determine whether transcutaneous electrical spinal cord stimulation (TSCS) could cause a change in the thoracic kyphosis (TK) and lumbar lordosis (LL) to re-establish normal sagittal spinal alignment. A case series study was conducted, wherein twelve individuals with SCI and ten neurologically intact subjects were scanned using 3D ultrasonography. In addition, three people with SCI having complete tetraplegia participated further to receive a 12-week treatment (TSCS with task-specific rehabilitation) after evaluation of sagittal spinal profile. Pre- and post-assessments were conducted to evaluate the differences in sagittal spinal alignment. The results showed that the TK and LL values for a person with SCI in a dependent seated posture were greater than those of normal subjects for: standing (by TK: 6.8° ± 1.6°; LL: 21.2° ± 1.9°), sitting straight (by TK: 10.0° ± 4.0°; LL: 1.7° ± 2.6°), and relaxed sitting (by TK: 3.9° ± 0.3°; LL: 7.7° ± 1.4°), respectively, indicating an increased risk for spinal deformity. In addition, TK decreased by 10.3° ± 2.3° after the TSCS treatment, showing a reversible change. These results suggest that the TSCS treatment could be used to restore normal sagittal spinal alignment for individuals with chronic SCI.

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.

In the Relationship Between Change in Kyphosis and Change in Lordosis: Which Drives Which?

STUDY DESIGN

Retrospective single-center study.

OBJECTIVE

Investigate the effect of posterior instrumentation on the relationship between lordosis and kyphosis.

METHODS

Surgically treated patients with a minimum of 6 months of follow-up were analyzed. Asymptomatic volunteers served to show the normal anatomical relationship between thoracic and lumbar curves. Patients were stratified based on postoperative instrumentation: "Thoracic Fusion" = complete fusion of thoracic spine; "Lumbar Fusion" = complete fusion of lumbar spine; and "Complete Fusion" = fusion from sacrum to at least T5. Bivariate correlations and regression analysis were used to evaluate the relationship between change in thoracic kyphosis (ΔTK) and change in spinopelvic mismatch (ΔPI-LL; pelvic incidence-lumbar lordosis) before and after fusion. Analyses were repeated in "Lumbar Fusion" patients with flexible preoperative thoracic spines.

RESULTS

For asymptomatic volunteers, the natural anatomical relationship between TK and LL was found to be TK = 41% of LL (r = 0.425, P < .001). A total of 153 of 167 adult spinal deformity patients were included (62 years old, 26.7 kg/m², 78% female). Mean follow-up was 11.5 ± 6.8 months. "Thoracic Fusion" group showed no alteration in the natural relationship between TK and LL (ΔTK = 39% ΔPI-LL), whereas "Lumbar Fusion" group had a reduction in reciprocal change (ΔTK = 34% ΔPI-LL) although a subanalysis of patients in the "Lumbar Fusion" group with flexible thoracic spines showed a marked compensation in reciprocal change with (ΔTK = 58% ΔPI-LL).

CONCLUSION

The relationship between ΔTK and ΔPI-LL is dependent on level instrumented. "Thoracic Fusion" drives change in LL while this relationship is affected by TK's natural stiffness in "Lumbar Fusion" patients.

Intraoperative Prone Radiographs During Scheuermann Kyphosis Correction Closely Estimate Standing Thoracic and Lumbar Parameters at 2 Years

BACKGROUND

In patients with Scheuermann kyphosis (SK) undergoing posterior spinal fusion with instrumentation (PSFI), intraoperative lateral radiographs assess deformity correction in the prone position. The relationship between thoracic and (partially un-instrumented) lumbar parameters on prone intraoperative versus standing postoperative radiographs is unknown.

METHODS

Forty-five consecutive patients with SK who underwent PSFI between 2007 and 2014 were reviewed. Thoracic kyphosis (TK), lumbar lordosis (LL), instrumented level kyphosis [upper instrumented vertebrae (UIV)-lower instrumented vertebrae (LIV)], and traditional sagittal parameters were recorded from preoperative standing, intraoperative prone, first outpatient standing, and >2-year standing radiographs and time periods were compared. Exclusion criteria included reduction modification after intraoperative radiographs and postoperative construct revision prohibiting comparison to initial intraoperative radiographs.

RESULTS

Twenty-five patients averaging 16 (12 to 20) years old during surgery with 3.1 (2 to 7) years follow-up met inclusion criteria. Average surgical variables included: 13±1 fusion levels, UIV at T2, LIV at L3, 3.8±1.6 osteotomies per patient, and 43±9% correction of TK. Preoperative TK and LL measured 82 and 76 degrees, respectively. TK on intraoperative (47 degrees), 6-week (49 degrees), and >2-year (50 degrees) radiographs changed significantly only between intraoperative and >2-year radiographs (P=0.03) by just 3 degrees. LL increased 5 degrees from intraoperative prone to 6-week standing radiographs (51 to 56 degrees, P=0.01) without further significant change at >2 years (59 degrees, P=0.09). Instrumented levels (UIV-LIV) had increased kyphosis at 6 weeks (32 to 35 degrees, P=0.01) without further change at >2 years (36 degrees, P=0.06).

CONCLUSIONS

TK on intraoperative prone radiographs during PSFI for SK should match the standing TK ∼6 weeks later. Intraoperative prone LL only slightly increases on early standing radiographs. Assuming a routine postoperative course, intraoperative radiographs slightly underestimate TK (by 3 degrees) and LL (by 8 degrees) on >2-year standing radiographs. These parameters (TK, LL, UIV-LIV) are visualized during surgery and should be used in future studies to predict long-term outcomes.

LEVEL OF EVIDENCE

Level IV-retrospective study.

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.

Sagittal Spinal and Pelvic Parameters in Patients With Scheuermann's Disease: A Preliminary Study

Background

Sagittal spinopelvic parameters remain poorly defined in patients with Scheuermann disease (SD). For example, although pelvic incidence (PI) should approximate lumbar lordosis (LL) by 10°, this is not true in patients with SD. This retrospective radiographic study was conducted to propose a new mathematical relationship between sagittal spinopelvic parameters in skeletally mature patients with SD.

Methods

The following formula (Δ) was proposed [(thoracic kyphosis - 45°) + (thoracolumbar kyphosis - 0°) + (PI - LL) = ± 10°] and validated with standard spino pelvic parameters in patients with skeletally mature SD without prior spine surgery at 2 centers between 2006 and 2015. The T1 pelvic angle (TPA) was used as a measure of global balance with normal maximum of 15°. Subgroup analysis was performed to compare Δ between balanced (TPA ≤ 15°) and unbalanced (TPA > 15°) patients with SD.

Results

In patients with SD (n = 30), half were female (n = 15), the average age was 39 years, and the average Δ was 2.4°. A significant correlation was discovered between Δ and both TPA (R ² = 0.75) and PI (R ² = 0.69). At TPA of 15°, average Δ was 9.2°. There was also a significant difference between balanced and unbalanced patients (-8.7° ± 11.6° versus 28.2° ± 19.7°, P = .0003).

Conclusions

This study of a new formula (Δ) to evaluate global sagittal balance in patients with SD found that accounting for the kyphosis maintained Δ within ± 10°. Further study is planned to determine whether maintaining and/or restoring a normal Δ is associated with improved outcomes in patients with SD after surgery.

Scheuermann's Disease: Radiographic Pathomorphology and Association with Clinical Features

STUDY DESIGN

Cross-sectional analytical study.

PURPOSE

To evaluate the spinal radiological features in patients with Scheuermann's disease and the association between the thoracic kyphosis angle and clinical presentation. Overview of the Literature: Scheuermann's disease is the most common cause of hyperkyphosis of the thoracic and thoracolumbar spine in adolescents; however, literature is limited in this area.

METHODS

Data regarding 150 successive X-ray images of 95 males and 55 females diagnosed with Scheuermann's disease were retrieved from the digital archives of the Maccabi Healthcare Services in Tel Aviv. Data included thoracic kyphosis angle (T3-T12), cervical lordosis (C2-C7), lumbar lordosis (L1-S1), sacral slope (SS), number and location of the anterior wedged vertebrae (AWV, minimum 5°), and C7 plumb line. Other data included age, sex, height, family history, Risser sign, self-perceived body image (rated by the Numeric Rating Scale [NRS]), and back pain during the previous week (rated by the Numeric Pain Rating Scale [NPRS]).

RESULTS

Significant positive associations were observed between the Cobb angle of thoracic kyphosis and age (r =0.186, p =0.023), cervical lordosis (r =0.263, p <0.001), lumbar lordosis (r =0.576, p <0.001), SS (r =0.236, p <0.004), T10-T12 Cobb angle (r =0.319, p <0.001), and number of AWV (r =0.519, p <0.001). The highest frequency of vertebral wedging was noted in T7 (68%), followed by T8 (65%) and T9 (44%). The NPRS showed a significant association only with SS (r =0.219, p =0.014). Significant positive associations were observed between the NRS for self-perceived body image, the thoracic kyphosis (r =0.494, p <0.001), and the number of AWV (r =0.361, p <0.001).

CONCLUSIONS

Thoracic kyphosis was significantly associated with cervical and lumbar lordosis, SS, T10-T12 Cobb angle, and AWV number. Pain was not substantial; however, self-perceived body image, the most common complaint of patients with Scheuermann's disease, was high and significantly associated with thoracic kyphosis and the number of AWV.

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.

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.

Distal Fusion Level Selection in Scheuermann's Kyphosis: A Comparison of Lordotic Disc Segment Versus the Sagittal Stable Vertebrae

STUDY DESIGN

Retrospective study.

OBJECTIVE

To compare 2 methods of selecting the lowest instrumented vertebra (LIV) on the rates of revision surgery for distal junctional kyphosis (DJK) following treatment for Scheuermann's kyphosis (SK).

METHODS

A retrospective review of patients who have undergone surgical treatment for SK was performed. Forty-four patients were divided into 2 groups based on intervention: Group 1 (n = 26) included patients who had an LIV distal to or at the sagittal stable vertebrae (SSV), and Group 2 (n = 18) included patients who had an LIV proximal to the SSV. For each group, demographic, radiographic, and revision surgery data was analyzed.

RESULTS

The average follow-up was 3.1 years. There were no differences among demographic variables between the groups. Preoperative and postoperative thoracic kyphosis, lumbar lordosis, and sagittal balance were not different between groups. Postoperatively, Group 1 demonstrated a significantly greater average lordotic disc angle below the LIV compared with Group 2 (Group 1, -6.2 ± 4.3° vs Group 2, -2.9 ± 5.8°; P = .02). In a subgroup analysis, extending fusions to the sagittal stable vertebra rather than the first lordotic disc resulted in fewer distal LIV complications necessitating revision surgery compared with fusing short of the SSV (5% vs 36.3%, P = .04).

CONCLUSION

The SSV method may reduce complications secondary to distal junctional failure, but at the expense of incorporating additional motion segments in a typically young population.

Cervical sagittal deformity develops after PJK in adult thoracolumbar deformity correction: radiographic analysis utilizing a novel global sagittal angular parameter, the CTPA

PURPOSE

To describe reciprocal changes in cervical alignment after adult spinal deformity (ASD) correction and subsequent development of proximal junctional kyphosis (PJK). This study also investigated these changes using two novel global sagittal angular parameters, cervical-thoracic pelvic angle (CTPA) and the T1 pelvic angle (TPA).

METHODS

Multicenter, retrospective consecutive case series of ASD patients undergoing thoracolumbar three-column osteotomy (3CO) with fusion to the pelvis. Radiographs were analyzed at baseline and 1 year post-operatively. Patients were substratified into upper thoracic (UT; UIV T6 and above) and lower thoracic (LT; UIV below T6). PJK was defined by >10° angle between UIV and UIV + 2 and >10° change in the angle from baseline to post-op.

RESULTS

PJK developed in 29 % (78 of 267) of patients. CTPA was linearly correlated with cervical plumbline (CPL) as a measure of cervical sagittal alignment (R = 0.826, p < 0.001). PJK patients had significantly greater post-operative CTPA and SVA than patients without PJK (NPJK) (p = 0.042; p = 0.021). For UT (n = 141) but not LT (n = 136), PJK patients at 1 year had larger CTPA (4.9° vs. 3.7°, p = 0.015) and CPL (5.1 vs. 3.8 cm, p = 0.022) than NPJK patients, despite similar corrections in PT and PI-LL.

CONCLUSIONS

The prevalence of PJK was 29 % at 1 year follow-up. CTPA, which correlates with CPL as a global analog of cervical sagittal balance, and TPA describe relative proportions of cervical and thoracolumbar deformities. Patients who develop PJK in the upper thoracic spine after thoracolumbar 3CO also develop concomitant cervical sagittal deformity, with increases in CPL and CTPA.

Correlation between preoperative spinopelvic alignment and risk of proximal junctional kyphosis after posterior-only surgical correction of Scheuermann kyphosis

BACKGROUND CONTEXT

Surgical correction of Scheuermann kyphosis (SK) is challenging and plagued by relatively high rates of proximal junctional kyphosis and failure (PJK and PJF). Normal sagittal alignment of the spine is determined by pelvic geometric parameters. How these parameters correlate with the risk of developing PJK in SK is not known.

PURPOSE

The study aimed to investigate the relationship between preoperative and postoperative spinopelvic alignment and occurrence of PJK and PJF.

STUDY DESIGN/SETTING

This is a retrospective observational cohort study.

PATIENT SAMPLE

The sample included 37 patients who underwent posterior correction of SK from January 2006 to December 2012.

OUTCOME MEASURES

The outcome measure was correlation analysis between preoperative and postoperative spinopelvic alignment parameters and the development of PJK over the course of the study period.

METHODS

Whole spine x-rays obtained before surgery, 3 months after surgery, and at the latest follow-up were analyzed. The following parameters were measured: thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). The development of PJK was considered the primary end point of the study. Patient population was split into a control and a PJK group; repeated-measures analysis of variance was used to assess group and time differences.

RESULTS

Seven patients developed PJK over the study period. Although the severity of the preoperative deformity (TK) did not differ significantly between the two groups, preoperative PI was significantly higher in the PJK group (51.9°C±8.6°C vs. 42.7°C±8.8°C, p=.018). Postoperative correction of TK was similar between the two groups (39.3% and 41.2%, p=.678) and final LL did not differ as well (53.6°C±9.2°C vs. 51.3°C±11.5°C). However, because PJK patients had larger preoperative PI values, a significant deficit of LL was observed at final follow-up in this group compared with the control group (ΔLL -10.5°C±9.8°C vs. 0.6°C±10.5°C, p=.013).

CONCLUSIONS

Scheuermann kyphosis patients who developed PJK appeared to have a significant postoperative deficit of LL (lumbopelvic mismatch). Lumbar lordosis decreases after surgery following correction of TK; therefore, TK correction should be planned according to preoperative PI values to avoid excessive reduction of LL in patients with higher PI values.

Sacral orientation and Scheuermann's kyphosis

To examine whether the association between spinal alignment and sacral anatomical orientation (SAO) can be detected in skeletal populations, by comparing SAO values in individuals with a typical SD to individuals with normal spinal alignment. 2025 skeletons were screened for Scheuermann's disease. Scheuermann's kyphosis was established by the presence of apophyseal abnormalities associated with more than 5° of anterior wedging in each of three adjacent vertebrae. SAO was measured as the angle created between the intersection of a line running parallel to the superior surface of the sacrum and a line running between the anterior superior iliac spine and the anterior-superior edge of the symphysis pubis (PUBIS). SAO was measured on 185 individuals with normal spines and 183 individuals with Scheuermann's kyphosis. Out of 2025 skeletons, 183 (9 %) were diagnosed with Scheuermann's kyphosis. The sacrum was significantly more horizontally oriented in individuals with Scheuermann's kyphosis compared with the control (SAO: 44.44 ± 9.7° vs. 50 ± 9.9°, p < 0.001). Alteration in spinal biomechanics due to a horizontally orientated sacrum may be an important contributing factor for the development of Scheuermann's kyphosis.

Flatback Revisited: Reciprocal Loss of Lumbar Lordosis Following Selective Thoracic Fusion in the Setting of Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective review of prospective multicenter adolescent idiopathic scoliosis (AIS) database.

OBJECTIVE

To investigate the relationship between iatrogenic loss of thoracic kyphosis (TK) after selective thoracic posterior spinal instrumentation and fusion (PSIF) for AIS with straightening of lumbar lordosis (LL).

SUMMARY OF BACKGROUND DATA

Segmental PSIF has become the standard of care for surgical treatment of severe AIS. Studies show that adults with flattening of TK and LL can develop pain and dysfunction associated with flatback syndrome. Analysis of post-fusion sagittal alignment is lacking in the AIS population.

METHODS

Query of prospective multicenter database for AIS patients with Lenke 1, 2, or 3 curves who underwent selective thoracic PSIF (lowest instrumented vertebra equal or cephalad to L1) identified 123 patients with a minimum of 2 years' follow-up. Thoracic kyphosis (T5-T12), LL (T12-S1), and global sagittal alignment were measured preoperatively and at 2 years postoperatively. Health-related quality of life measures were examined.

RESULTS

A total of 31% of patients had loss of TK and 42% lost LL. Patients with decreased TK had significantly higher rates of decreased LL (68%) than patients without decreased TK (31%). Multivariate regression confirmed that TK had significant predictive effect on LL (p < .001). Specifically, change in TK of 2° was associated with roughly 3° change in LL. There were no significant associations between changes in TK or LL and health-related quality of life.

CONCLUSIONS

Loss of TK occurs commonly in selective fusion for AIS. This loss of kyphosis is strongly associated with reciprocal loss of LL. Spinal fusion can have unintended effects on sagittal alignment; these effects may have consequences that remain to be fully elucidated.

Comparison of radiographic sagittal spinopelvic alignment between skeletally immature and skeletally mature individuals with Scheuermann's disease

PURPOSE

The aim of this study was to compare radiographic sagittal spinopelvic parameters between skeletally immature and skeletally mature patients with Scheuermann's disease (SD).

METHODS

Cross-sectional analysis of standing postero-anterior and lateral radiographs of the spine of patients with SD was performed. Sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured on the lateral radiographs. Risser's sign was assessed on the postero-anterior radiographs. All of the parameters measured were compared between skeletally immature (Risser's sign 0-3) versus mature patients (Risser's sign 5). PI, PT, and SS in both groups were compared to PI, PT, and SS reported for normal children, adolescents, and adults.

RESULTS

Sixty-six patients with SD (33 immature and 33 mature) were retrospectively reviewed and included in the study. There was no significant difference between the two groups of SD patients in: SVA (-16.6 vs. -22.9 mm, p = 0.74), TK (57.8° vs. 56°, p = 0.66), TLK (7.8° vs. 11.7º, p = 0.14), LL (63.2° vs. 62.2°, p = 0.74), PI (36.7° vs. 39.4°, p = 0.20), PT (3.8° vs. 7.3°, p = 0.10), and SS (32.8° vs. 32.1°, p = 0.75). Both, the immature and mature group of SD patients presented significantly lower PI and SS than normal children, adolescents, and adults, and significantly lower PT than normal adults.

CONCLUSIONS

There is no significant difference in sagittal spinopelvic parameters between skeletally immature and mature subjects with SD. Pelvic incidence in both groups of SD patients was significantly lower than PI in normal children, adolescents, and adults. This challenges the role of PI in predicting desired LL in patients with SD.

Radiographic spinopelvic parameters in skeletally mature patients with Scheuermann disease

STUDY DESIGN

Retrospective radiographical analysis of sagittal spinopelvic parameters in skeletally mature patients with Scheuermann disease (SD).

OBJECTIVE

To analyze anatomical and positional parameters of spinopelvic sagittal alignment in mature patients with SD.

SUMMARY OF BACKGROUND DATA

Sagittal spinopelvic alignment has already been characterized in normal subjects and deviations in sagittal parameters have been reported for various spinal pathologies. No study has investigated spinopelvic parameters in SD.

METHODS

Standing posteroanterior and lateral radiographs of the skeletally mature patients with SD were analyzed. Immature patients and those with other spinal pathologies were excluded from the study. Pelvic positional and anatomic parameters and spinal parameters were measured. Pelvic incidence (PI) was compared with the values reported for healthy individuals. Correlations between the measured parameters were analyzed.

RESULTS

Forty patients met the inclusion criteria. Sixteen females and 24 males (mean age, 25 yr) were analyzed. The mean PI in this group was 40° and was significantly lower than that reported for healthy adults and adolescents (P < 0.0001) and not significantly different than the values reported for healthy children (P = 0.44). Patients with atypical (thoracolumbar) SD had lower PI than those with typical (thoracic) form (41° vs. 38°; P = 0.09). There was no correlation between PI and LL, thoracic kyphosis, or thoracolumbar kyphosis.

CONCLUSION

This study demonstrated that skeletally mature patients with SD have significantly lower PI than healthy adults. There was no correlation between PI and LL in individuals with SD. This challenges the role of PI in predicting the proper values of LL in this group of patients. Further studies are needed to investigate whether impaired spinopelvic alignment is a cause or a result of SD.

LEVEL OF EVIDENCE

3.

Association between body mass index, body height, and the prevalence of spinal deformities

BACKGROUND CONTEXT

The most common spinal deformities among adolescents are adolescent idiopathic scoliosis (AIS; 2%-3% prevalence) and Scheuermann kyphosis (SK; 1%-8% prevalence). Both are believed to have a genetic influence in their etiology. The association between body mass index (BMI) and body stature and their possible association to spinal deformities is uncertain.

STUDY DESIGN

A cross-sectional prevalence study.

PURPOSE

To examine the prevalence of all adolescent spinal deformities according to the extent of their severity as well as their possible association to BMI and body height.

OUTCOME MEASURES

Subjects diagnosed as having spinal deformities were classified into one of three severity groups; "Mild," "Intermediate," or "Severe," according to their curve scoliosis or kyphosis measurement with a standing X-ray.

METHODS

The data for this study were derived from a medical database containing records of 17-year-old male and female patients before their recruitment into mandatory military service. Information on the disability codes associated with spinal deformities according to the Regulations of Medical Fitness Determination was retrieved. Logistic regression models were used to assess the association between the BMI and body height to various degrees of spinal deformities by severity.

RESULTS

The study cohort included 829,791 consecutive subjects, of whom 103,249 were diagnosed with spinal deformities (76% were mild in degree). The prevalence of spinal deformities was significantly greater among the underweight male and female patients (p<.001). Increased BMI had a protective effect for developing spinal deformities. The odds ratios for severe spinal deformities were greater compared with mild spinal deformities in the underweight groups. The risk for developing spinal deformities increased significantly with height for both genders (p<.001).

CONCLUSIONS

An association between height and the risk for spinal deformities by severity was found for all height groups. Below normal BMI is associated with severity of spinal deformities, whereas above-normal BMI apparently has a protective effect. Body height is also positively associated with the severity of spinal deformities.

Improvement of clinical and radiographical presentation of Scheuermann disease after Schroth therapy treatment

BACKGROUND

Scheuermann's disease is the most common cause of hyperkyphosis of the thoracolumbar spine. Few case reports have demonstrated the effectiveness of Schroth therapy in improving the thoracic angle curve in Scheuermann's patients; however, additional verification is needed.

CASE DESCRIPTION

A 14-year-old female patient presented with Scheuermann's disease. On X-ray, thoracic kyphosis was 55° and lumbar lordosis 55°. The self-rated cosmetic disturbance was graded 10/10 on a verbal numeric scale. The patient received a course of seven weekly Schroth therapy sessions, in addition to daily home exercises tailored specifically for the patient's posture. Five months later, follow-up X-rays revealed thoracic kyphosis of 27° and lumbar lordosis 35°. The patient graded the degree of her cosmetic disturbance as 3/10.

CONCLUSIONS

Schroth therapy seems to be able to decrease the thoracic curve angle of Scheuermann's patients; however, efficacy and effectiveness of this method should be investigated in future prospective controlled clinical trials.

Sagittal spinopelvic alignment in adolescents associated with Scheuermann's kyphosis: a comparison with normal population

PURPOSE

Spinopelvic alignment is increasingly considered as a main factor in the energy-efficient posture of the individual in normal and pathological status. However, the spinopelvic characteristics in Scheuermann's kyphosis (SK) are poorly defined in the literature. The purpose of this study was to determine whether differences of the spinopelvic parameters exist between adolescents with SK and age-matched normal controls.

METHODS

In this study, 55 patients with SK and 60 healthy age-matched adolescents were recruited consecutively. Sagittal spinal and pelvic parameters were measured from the standing lateral radiograph, including global kyphosis, thoracic kyphosis (TK), cervical lordosis (CL), lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), pelvic tilt (PT) and sagittal vertical axis (SVA). According to the location of the kyphosis, patients were subdivided into Scheuermann's thoracic kyphosis (STK) group and Scheuermann's thoracolumbar kyphosis (STLK) group. The radiographic comparison and correlation analysis were further performed.

RESULTS

SK patients had significantly lower PI and PT than normal controls (32.0° vs. 45.0°, P < 0.001 for PI; 0.2° vs. 11.9°, P < 0.001 for PT). The rate of a negative PT was 41.8 % (22/55) in SK patients, which was remarkably higher than in normal controls (10.0 %, 6/60). The CL, TK and LL were significantly increased in STK group when compared with STLK and control groups. A significant correlation was noticed between TK and CL and also between TK and LL in STK group. Both TK and LL were decreased in STLK patients, and a significant correlation was found between them (r = -0.687, P < 0.001). A significantly strong correlation was also observed between LL and SS in STLK patients (r = -0.641; P < 0.001).

CONCLUSION

Adolescents with SK have a significantly lower PI when compared with age-matched normal controls. Patients with different curve patterns (STK vs. STLK) could have distinct compensatory mechanisms to maintain the sagittal balance.

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.

Thoracic hyperkyphosis: assessment of the distal fusion level

Study Design This is a retrospective study. Objective The objective of this study was to assess the sagittal stable vertebra (SSV) versus the first lordotic vertebra (FLV) as the inferior fusion level in patients undergoing spinal surgery for thoracic hyperkyphosis. The main outcome of interest was the development of distal junctional kyphosis (DJK). Summary of Background Data Prior research has pointed to selection of the FLV for the distal instrumentation level in fusion for thoracic hyperkyphosis. In 2009, Cho et al introduced the concept of the SSV after recognizing the development of DJK despite fusion to the FLV. Methods Patients were reviewed who had undergone spinal fusion for thoracic hyperkyphosis. Preoperative radiographs were reviewed to assess thoracic kyphosis, lumbar lordosis, SSV, and FLV. Postoperative radiographs were reviewed to assess curve correction and whether patients developed DJK or implant failure. Results We reviewed 22 patients with a mean age at surgery of 18 (range 14 to 22). Mean preoperative kyphosis was 85 ± 14 degrees, and mean postoperative kyphosis at final follow-up was 59 ± 12 degrees for a mean correction of 26 ± 12 degrees. Eleven patients developed DJK and four patients experienced hardware failure. In 12 patients, the SSV was inferior to the FLV. Rates of DJK when the instrumentation included the SSV or FLV were 13 and 38%, respectively. Conclusions Fusion to the SSV is superior at preventing DJK when compared with fusion to the FLV.

Evidence based medicine: analysis of Scheuermann kyphosis

STUDY DESIGN

: A review of the current literature using evidence-based medicine (EBM) regarding etiology, natural history, and treatment of Scheuermann kyphosis.

OBJECTIVE

: To provide current concepts for the rational evaluation and treatment of Scheuermann kyphosis supported by EBM.

SUMMARY OF BACKGROUND DATA

: The literature concerning etiology, natural history, and treatment of Scheuermann disease has mixed views and recommendations, most of which are not strongly supported with levels of evidence.

METHODS

: A thorough database search was performed in order to obtain the best current information and levels of evidence on etiology, natural history, and treatment options for Scheuermann kyphosis based on EBM criteria.

RESULTS AND CONCLUSION

: Scheuermann kyphosis is the most common cause of hyperkyphosis in adolescence. Its true etiology remains unknown, but there appears to be a strong genetic as well as an environmental contribution. The kyphotic deformity is frequently attributed to "poor posture" resulting in delayed diagnosis, and treatment indications remain debated because the natural history has not been clearly defined. When recognized early in adolescence with progressive kyphosis, bracing treatment will usually result in modest correction of the deformity. Symptomatic adolescents with severe deformity have demonstrated significant deformity correction following surgical intervention; however, clinical outcomes data are not yet available, and the studies available do not have strong levels of evidence.

Predictability of the spontaneous lumbar curve correction after selective thoracic fusion in idiopathic scoliosis

In this study we tried to achieve a better understanding of the biodynamic mechanism of balance in the scoliotic spine. Therefore we focused on the pre- and postoperative spine of patients with idiopathic scoliosis with a primary thoracic curve and a secondary lumbar curve. Several studies showed that the lumbar curve spontaneously corrects and improves after selective thoracic fusion. We try to understand and describe this spontaneous compensatory lumbar curve correction after selective thoracic correction and fusion. We performed a retrospective examination of pre- and postoperative radiographs of the spine of 38 patients with idiopathic scoliosis King type II and III. Frontal Cobb angles of the thoracic and lumbar curves were assessed on pre- and postoperative antero-posterior and side bending radiographs. We determined the postoperative corrections of the thoracic and lumbar curves. Relative (%) corrections and correlations of the postoperative corrections were calculated. The group was divided in three subgroups, depending on lumbar curve modifier, according to Lenkes classification system. The calculations were done for the whole group as for each subgroup. As expected, significant correlations were present between the relative correction of the main thoracic and the lumbar curve (mean R = 0.590; P = 0.001). The relation between relative thoracic and lumbar correction decreased with the lumbar modifier type. This study shows a highly significant correlation between the relative corrections of the main thoracic curve and the lumbar curve after selective thoracic fusion in idiopathic scoliosis. This correlation depends on lumbar curve modifier type. This new classification system seems to be of great predictable value for the spontaneous correction of the lumbar curve. Depending on the curve-type, a different technique for predicting the outcome should be used. The lumbar curve correction does not occur throughout the whole lumbar curve. Most correction is achieved in the upper part of the curve. The distal lumbar curve seems to be more rigid and less important in the spontaneous curve correction.