The surgical management of Scheuermann's disease

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.

Operative choices matter: the role of UIV and sagittal balance in the development of proximal junctional kyphosis following posterior instrumentation for Scheuermann's kyphosis

PURPOSE

This study sought to investigate associations between upper instrumented vertebra (UIV) location and the risk of proximal junctional kyphosis (PJK) at 2 years following posterior spinal fusion (PSF) for Scheuermann's kyphosis (SK).

METHODS

In this retrospective cohort study, SK patients who underwent PSF and reached 2 years postop were identified in a multicenter international registry, excluding those with anterior release, prior spine surgery, neuromuscular comorbidity, post-traumatic kyphosis, or kyphosis apex below T11-T12. Location of UIV as well as the number of levels between UIV and preoperative kyphosis apex was determined. Additionally, the degree of kyphosis correction was evaluated. PJK was defined as a proximal junctional angle ≥ 10° that is ≥ 10° greater than the preoperative measurement.

RESULTS

90 patients (16.5 ± 1.9 yo, 65.6% male) were included. Preoperative and 2-year postoperative major kyphosis was 74.6 ± 11.6° and 45.9 ± 10.5°, respectively. Twenty-two (24.4%) patients developed PJK at 2 years. Patients with UIV below T2 had a 2.09 times increased risk of PJK when compared to those with UIV at or above T2, adjusting for distance between UIV and preoperative kyphosis apex [95% Confidence Interval (CI) 0.94; 4.63, p = 0.070]. Patients with UIV ≤ 4.5 vertebrae from the apex had a 1.57 times increased risk of PJK, adjusting for UIV relative to T2 [95% CI 0.64; 3.87, p = 0.326].

CONCLUSION

SK patients with UIV below T2 had an increased risk of developing PJK at 2 years following PSF. This association supports consideration of UIV location during preoperative planning.

LEVEL OF EVIDENCE

Prognostic Level II.

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.

Evaluation and management of paediatric and adolescent back pain: Epidemiology, presentation, investigation, and clinical management: A narrative review

This narrative review will summarise a clinical approach to the investigation of back pain in children and adolescent patients, including a discussion of the epidemiology, presentation, investigation and clinical management of back pain in children and adolescents. This will assist the prompt and accurate diagnosis of spinal disorders that require significant medical intervention. Existing evidence suggests a relatively high incidence of non-specific back pain among young people; 27-48% of presentations of back pain in children and adolescents are attributed to non-specific back pain. Low back pain among schoolchildren is often linked to psychosocial factors and only occasionally requires medical attention, as pain is benign and self-limiting. Nonetheless, those young patients who seek medical assistance exhibit a higher incidence of organic conditions underlying the major symptom of spinal pain. A cautious and comprehensive strategy - including a detailed history, examination, radiographic imaging and diagnostic laboratory studies - should be employed, which must be accurate, reliable, consistent and reproducible in identifying spinal pathologies. A specific diagnosis can be reached in 52-73% of the cases. For cases in which a specific diagnosis cannot be made, re-evaluation after a period of observation is recommended. At this later stage, minor symptoms unrelated to underlying pathology will resolve spontaneously, whereas serious pathologies will advance and become easily identified.

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.

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.

Poor Radiological and Good Functional Long-term Outcome of Surgically Treated Scheuermann Patients

STUDY DESIGN

Cohort study.

OBJECTIVE

To analyze long-term clinical and radiological outcomes of surgically treated Scheuermann patients.

SUMMARY OF BACKGROUND DATA

Long-term clinical and radiological outcomes of surgery for Scheuermann kyphosis are unknown. A single-center cohort of 33 consecutive, surgically treated (between 1991 and 1998) Scheuermann patients was studied.

METHODS

Clinical and radiological data of 29 surgically treated Scheuermann patients were collected (posterior approach n = 13; combined anterior-posterior procedure n = 16), after a mean follow-up of 18 years. Oswestry Disability Index (ODI) scores were measured preoperatively (PRE) and twice postoperatively: 2 to 8 years postoperative (FU 1) and 14 to 21 years postoperative (FU 2). Visual Analog Score pain, Short Form-36 (SF-36), and EQ-5d scores were recorded at FU 2 only. Radiographs were analyzed for correction, distal and proximal junctional kyphosis, and implant failures.

RESULTS

Mean preoperative kyphosis of the corrected levels was 76° (range 60°-105°) and decreased to a Cobb of 58°(range 30°-105°) at FU 2. Median Visual Analog Score was 2.5 points (range 0-8) and median ODI score was 12 (range 0-62) at FU 2. The ODI score at FU 1 was significantly better as compared to PRE (P < 0.001) and FU 2 (P < 0.001). Also, anterior-posterior treated group had a significantly better ODI score as compared to the posterior-only group (P = 0.023). EQ-5d scores on mobility, usual activities, and pain/discomfort were worse compared to an age-matched population control group; however, SF-36 outcome scores were comparable.Proximal junctional kyphosis was present in 53% of patients, distal junctional kyphosis did not occur, and implant failure/removal had occurred in 69% of patients. Radiological complications do not relate with the ODI, EQ-5d, and SF-36 and 72% of the patients were satisfied.

CONCLUSION

Radiological results of this cohort were disappointing but did not relate to clinical outcome scores. Even lumbar pain could not prevent a high patient satisfaction and quality of life. Patients treated with a combined anterior-posterior approach tended to perform better.

LEVEL OF EVIDENCE

3.

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.

Comparison of Scheuermann's kyphosis correction by combined anterior-posterior fusion versus posterior-only procedure

INTRODUCTION

Conventional treatment of rigid deformity in Scheuermann's kyphosis (SK) in young patients includes a preliminary anterior spinal release and fusion (ASF) followed by posterior spinal fusion and instrumentation (PSF). However, recently there are more trends to do posterior-only surgery for correction of this deformity. The aim of our study was to compare clinical and radiological outcomes of ASF/PSF and PSF-only procedures in treatment of SK.

MATERIALS AND METHODS

In a prospective clinical and radiological review, thirty operated SK patients in two groups were evaluated. Group A: ASF/PSF technique (n: 16) and group B: PSF-only procedure (n: 14) were followed for at least 2 years (average 57.6 months). Two groups were well matched for the following four criteria: average age, flexibility status, posterior fusion levels, and preoperative Cobb's kyphosis angle. Oswestry disability index (ODI) and scoliosis research society questionnaire-30 (SRS-30) and radiological (kyphosis correction, correction loss, sagittal balance) parameters were evaluated before and after surgery and at the final follow-up.

RESULTS

In group A, primary thoracic Cobb's kyphosis, immediate post-operative kyphosis, and final follow-up kyphosis angle were 83.6°, 41.4° and 43°, respectively (P < 0.05). Correction rate and correction loss were 50.5 % and 1.6° ± 2.4, respectively. In group B, the corresponding values were 81.9°, 40.1° and 43.2°, respectively (P < 0.05). Correction rate and correction loss were 51 % and 3.1° ± 2.5, respectively. SRS-30 and ODI scores in group A were averaged 68.5 and 21.3 preoperatively and 128.7 and 6.25 at the final follow-up, respectively. In group B, the corresponding values were 64 and 23.2 preoperatively and 133.5 and 5.8 at the final follow-up, respectively.

CONCLUSIONS

Clinical and radiological parameters were similar in both groups after surgical correction while, complication rates, operation time and blood loss were significantly higher in ASF/PSF procedure.

Proximal Junctional Kyphosis Following Spinal Deformity Surgery in the Pediatric Patient

Proper understanding and restoration of sagittal balance is critical in spinal deformity surgery, including conditions such as adolescent idiopathic scoliosis and Scheuermann kyphosis. One potential complication following spinal reconstruction is proximal junctional kyphosis. The prevalence of proximal junctional kyphosis varies in the literature, and several patient- and surgery-related risk factors have been identified. To date, the development of proximal junctional kyphosis has not been shown to lead to a negative clinical outcome following spinal fusion for adolescent idiopathic scoliosis or Scheuermann kyphosis. Treatment options range from simple observation in asymptomatic cases to revision surgery with extension of the fusion proximally. Several techniques and technologies are emerging that seek to address and prevent proximal junctional kyphosis.

National Trends in Spinal Fusion Surgery For Scheuermann Kyphosis

STUDY DESIGN

Analysis of a national database.

OBJECTIVE

To analyze national trends in spinal fusion surgery for Scheuermann kyphosis (SK) and to compare surgical approaches used in treatment.

SUMMARY OF BACKGROUND DATA

The preferred surgical approach for treating SK is not well established. Recent studies support the use of posterior spinal fusion (PSF) instead of anterior-posterior spinal fusion (APSF).

METHODS

Using the Nationwide Inpatient Sample database, we identified 2,796 patients (mean age, 24.9 years; 66% men) from 2000 to 2008 who had spinal fusion surgery for SK. We compared the two approaches with respect to patient demographics, institutional characteristics, in-hospital complications, and hospitalization lengths and costs. Significance was set at a value of p less than .05.

RESULTS

The number of spinal fusion surgeries performed in patients with SK increased significantly (p = .03). The proportion of patients undergoing surgery as adults also increased significantly (p < .05). The number of PSF surgeries performed in patients with SK increased 2.9-fold (34% to 78%) (p < .01); APSF use declined by 7% per year. There was no significant association among surgical approach and patient age, sex, hospital capacity, or teaching status. Compared with patients undergoing PSF, patients undergoing APSF had 2.1-fold more in-hospital complications (p < .01), 3.8-fold more pulmonary complications (p < .01), 2.7-fold more renal complications (p < .01), and significantly longer hospitalizations (mean, 8.5 days vs. 5.9 days, respectively; p < .01). There was no significant difference in mean total hospital charges: $117,921 for APSF and $119,322 for PSF.

CONCLUSION

There have been significant increases in the number of spinal fusion surgeries for SK, and in the proportion of patients with SK who are choosing surgery as adults. Surgical treatment has shifted predominantly toward an all-posterior approach. PSF is associated with lower complication rates (especially pulmonary complications) and shorter hospitalizations.

Change in Sagittal Plane Alignment Following Surgery for Scheuermann's Kyphosis

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

To evaluate changes in sagittal plane alignment in patients with Scheuermann's kyphosis after spinal fusion.

SUMMARY OF BACKGROUND DATA

Although surgery is commonly undertaken in patients with severe Scheuermann's kyphosis for deformity correction, there are limited data regarding the response of spinopelvic parameters and sagittal plane alignment of the spine to surgical treatment.

METHODS

Eighteen consecutive surgical Scheuermann's kyphosis patients were retrospectively reviewed (mean preoperative kyphosis, 76°). Full-length spine films were evaluated for maximal sagittal Cobb angle, thoracic kyphosis, cervical and lumbar lordosis, pelvic parameters, and sagittal plane alignment. Findings were compared with reported literature values in normal patients.

RESULTS

After surgery, thoracic kyphosis improved significantly, with mean maximum kyphosis improving from 76° to 56° (p = .001). Preoperative cervical lordosis was increased compared with reported normal adolescent values (-35° vs. -5°) and did not significantly change after surgery. Lumbar lordosis decreased significantly after surgery, from -77° to -57° (p = .023). No change was noted in pelvic tilt, sacral slope, or pelvic incidence. Furthermore, there was little improvement in sagittal plane alignment. Preoperatively, 12 of the 18 patients had deviation in sagittal plane alignment greater than 2 cm (5 positive and 7 negative); postoperatively, 11 patients had persistent sagittal imbalance (6 positive and 5 negative). Five patients were noted to have proximal junctional kyphosis and 3 underwent revision surgery for malpositioned screw (1) and loss of distal fixation (2).

CONCLUSIONS

Surgical management of Scheuermann's kyphosis resulted in normalization of thoracic kyphosis and lumbar lordosis. Compared with reported values in unaffected adolescents, cervical lordosis remained increased and most patients had residual sagittal plane imbalance greater than 2 cm on imaging.

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

INTRODUCTION

Posterior-only approach using pedicle screws' fixation has emerged as the preferred surgical technique for Scheuermann kyphosis (SK) correction. Insertion of multiple pedicle screws while increasing stability increases also the risk of complications related to screw malpositioning and surgical cost. The optimal screw density required in surgical correction of SK remains unclear. This study compares the safety and efficacy of low screw density (LSD) versus high screw density (HSD) technique used in posterior-only correction of SK.

METHODS

Twenty-one patients underwent surgical correction of SK between 2007 and 2011 and were reviewed after a mean of 29 months. HSD technique (i.e., 100 % of available pedicles, averaged 25.2 ± 4 screws) was used in 10 cases and LSD technique (i.e., 54-69 % of available pedicles in a pre-determined pattern, averaged 16.8 ± 1.3 screws; p < 0.001) was used in 11 cases. Kyphosis correction was assessed by comparing thoracic kyphosis, lumbar lordosis and sagittal balance on preoperative and postoperative radiographs. Cost saving analysis was performed for each group.

RESULTS

Preoperative thoracic kyphosis, lumbar lordosis and sagittal balance were similar for both groups. The average postoperative kyphosis correction was similar in both HSD and LSD groups (29° ± 9° vs. 34° ± 6°, respectively; p = 0.14). Complication occurred in four patients (19 %) in the HSD group and in two patients (9 %) in the LSD group (p = 0.56). Three patients required re-operation. Compared to HSD using LSD saves 4,200 pounds sterling per patient in hardware and 88,200 pounds sterling for the entire cohort.

CONCLUSION

LSD technique is as safe and effective as HSD technique in posterior-only correction of SK. Implant-related cost could be reduced by 32 %.

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.

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.

SCHEUERMANN'S KYPHOSIS: COMPARISON BETWEEN THE POSTERIOR APPROACH ASSOCIATED WITH SMITH-PETERSEN OSTEOTOMY AND COMBINED ANTERIOR-POSTERIOR FUSION

OBJECTIVE

Surgical treatment of Scheuermann's kyphosis (SK) remains a subject under discussion. In view of the controversy over the best form of surgical tr otomy.

METHODS

This was a descriptive case-control study with cross-sectional analysis. Twenty-eight patients, split into two groups conducted at different times, were evaluated.

RESULTS

The first group comprised patients treated using the double approach, with an average age of 19 years, preoperative kyphosis of 77.6°, postoperative kyphosis of 35.8° and average correction of 53.2%. The second group comprised patients treated using the posterior route associated with Smith-Petersen osteotomy, with a mean age of 27.3 years, preoperative kyphosis of 72.9°, postoperative kyphosis of 44.3° and average correction of 39.3%. Analysis between the two groups showed statistically significant differences in the following variables: age (p = 0.02), postoperative kyphosis (p = 0.04) and degree and percentage of kyphosis correction (p = 0.001). There was no difference concerning preoperative kyphosis (p = 0.33). In the assessment of postoperative pain (VAS), the first group presented an average of 0.6, versus 0.5 in the second group. There were only minor complications: seven in the first group and two in the second.

CONCLUSION

The two surgical techniques studied proved to be adequate for treating SK. In the present study, the deformity correction was greater in the first group, while the pain VAS results were better in the second group, with lower incidence of complications.

[Correction of adolescent kyphosis. What is the state of the art?]

Thoracic and thoracolumbar kyphosis is a common deformity in pediatric and adolescent populations. Kyphotic deformation of the spine is defined as a curve which shows an increase in the dorsal convex angulation. The most common causes of kyphosis in pediatric and adolescent populations are Scheuermann's disease, postural and congenital kyphosis. The fundamental principles of treatment are analysis of the kyphotic deformity and restoration or maintenance of sagittal balance. Clinically significant sagittal deformities can lead to severe pain, substantial cosmetic alterations, spinal cord dysfunction, problems with swallowing, gastrointestinal and cardiopulmonary complications. When the kyphotic deformity exceeds a certain point and conservative therapy options are no longer sufficient surgical intervention is indicated. The available operative options for treatment of the various types of pediatric and adolescent thoracolumbar kyphosis include dorsal instrumentation and fusion combined with ventral fusion and purely ventral instrumentation and fusion.

Complications of spinal fusion for scheuermann kyphosis: a report of the scoliosis research society morbidity and mortality committee

STUDY DESIGN

Retrospective review of a prospectively collected, multicentered database from the Scoliosis Research Society.

OBJECTIVES

To evaluate incidences of complications in a series of spinal fusions for Scheuermann kyphosis (SK) and to assess whether the incidence of complications is associated with patient age and surgical approach.

SUMMARY OF BACKGROUND DATA

Although there is some evidence that adolescents have lower complication rates for spinal deformity surgery, this has not been well-documented for SK. Moreover, there is a lack of consensus on surgical approach for the management of SK.

METHODS

The Scoliosis Research Society morbidity and mortality database was queried to identify cases of SK from 2001 to 2004. Complications rates were analyzed based on patient age and surgical approach. Pediatric and adult patients were defined as <or=19 and >19 year old, respectively.

RESULTS

A total of 683 procedures involving spinal fusion for SK were identified. Mean patient age was 21 years (range: 5-75 years), with the majority (73%) of patients <or=19 years old. Procedures included 338 (49%) posterior spinal fusions (PSF), 73 (11%) anterior spinal fusions (ASF), and 272 (40%) same-day ASF and PSF. Ninety-nine complications were reported (14%). The most common complication was wound infection (3.8%). The acute neurologic complication rate was 1.9%, including 4 spinal cord injuries (0.6%). The mortality rate was 0.6%. Complications were more common among adult (22%) compared with pediatric patients (12%) (P = 0.002). The overall incidence of complications did not differ significantly between the PSF (14.8%) and same-day ASF/PSF (16.9%) procedures (P = 0.5).

CONCLUSION

The incidence of complications associated with spinal fusion for SK in adults is significantly greater than in pediatric patients. There were no significant differences in complication rates between PSF and same-day ASF/PSF procedures. These data may be used to counsel patients regarding complications associated with spinal fusion for SK in the hands of experienced spinal deformity surgeons.

Spontaneous fusion across the apex of severe thoracolumbar Scheuermann's kyphosis: A surgical consideration

Considerable debate exists regarding the pathogenesis, natural history and treatment of Scheuermann's kyphosis. Surgical correction is indicated in the presence of severe kyphosis which carries the risk of neurological complications, persistent back pain and significant cosmetic deformity. This can be achieved through a posterior-only or an anteroposterior approach. Spontaneous fusion in association with Scheuermann's kyphosis has not been previously described. This is an important consideration if surgical correction of the kyphosis is planned. Two patients with severe thoracolumbar Scheuermann's kyphosis who developed spontaneous posterior and anteroposterior fusion across the apex of the deformity are presented. The surgical treatment and final outcome is discussed.

Incidence and risk factors for proximal and distal junctional kyphosis following surgical treatment for Scheuermann kyphosis: minimum five-year follow-up

STUDY DESIGN

Retrospective case review at a single center.

OBJECTIVE

To analyze the incidence and risk factors associated with proximal junctional kyphosis (PJK) and distal junctional kyphosis (DJK) in patients undergoing instrumented spinal fusion for Scheuermann kyphosis.

SUMMARY OF BACKGROUND DATA

Previously reported risk factors for junctional kyphosis include improper end vertebrae selection, curve correction greater than 50%, or excessive junctional soft tissue dissection.

METHODS

Clinical and radiographic data on 67 patients (mean age 37) from a single center treated with instrumented fusion for Scheuermann kyphosis were reviewed. All patients had complete radiographic data with a minimum 5-year follow-up (mean: 73 months). Abnormal PJK was defined by a proximal junctional angle greater than 10 degrees and at least 10 degrees greater than the corresponding preoperative measurement. DJK was similarly defined between the caudal endplate of the lower instrumented vertebra to the caudal endplate that was 1 vertebra below.

RESULTS

The incidence of PJK as defined above was seen in 20 patients (30%). The development of PJK was associated with failure to incorporate the proximal end vertebra (15 patients), disruption of junctional ligamentum flavum (3 patients), or combination of both (2 patients). The most common cause of inappropriate end vertebra selection was poor visualization of the upper thoracic vertebra.DJK occurred in 8 patients (12%) and 7 of them had fusion short of including the first lordotic disc.

CONCLUSION

The incidence of PJK can be minimized by the appropriate selection of the upper end vertebra to be fused and avoiding disruption of the junctional ligamentum flavum. The development of DJK can be minimized by incorporation of the first lordotic disc into the fusion construct.

Preventing distal pullout of posterior spine instrumentation in thoracic hyperkyphosis: a biomechanical analysis

STUDY DESIGN

An in vitro biomechanical study.

OBJECTIVE

Compare the mechanical behavior of 5 different constructs used to terminate dual-rod posterior spinal instrumentation in resisting forward flexion moment.

SUMMARY OF BACKGROUND DATA

Failure of the distal fixation construct can be a significant problem for patients undergoing surgical treatment for thoracic hyperkyphosis. We hypothesize that augmenting distal pedicle screws with infralaminar hooks or sublaminar cables significantly increases the strength and stiffness of these constructs.

METHODS

Thirty-seven thoracolumbar (T12 to L2) calf spines were implanted with 5 configurations of distal constructs: (1) infralaminar hooks, (2) sublaminar cables, (3) pedicle screws, (4) pedicle screws+infralaminar hooks, and (5) pedicle screws+sublaminar cables. Progressive bending moment was applied to each construct until failure. The mode of failure was noted and the construct's stiffness and failure load determined from the load-displacement curves.

RESULTS

Bone density and vertebral dimensions were equivalent among the groups (F=0.1 to 0.9, P>0.05). One-way analysis of covariance (adjusted for differences in density and vertebral dimension) demonstrated that all of the screw-constructs (screw, screw+hook, and screw+cable) exhibited significantly higher stiffness and ultimate failure loads compared with either sublaminar hook or cable alone (P<0.05). The screw+hook constructs (109+/-11 Nm/mm) were significantly stiffer than either screws alone (88+/-17 Nm/mm) or screw+cable (98+/-13 Nm/mm) constructs, P<0.05. Screw+cable construct exhibited significantly higher failure load (1336+/-328 N) compared with screw constructs (1102+/-256 N, P<0.05), whereas not statistically different from the screw+hook construct (1220+/-75 N). The cable and hook constructs failed by laminar fracture, screw construct failed in uniaxial shear (pullout), whereas the screws+(hooks or wires) failed by fracture of caudal vertebral body.

CONCLUSIONS

Posterior dual rod constructs fixed distally using pedicle screws were stiffer and stronger in resisting forward flexion compared with cables or hooks alone. Augmenting these screws with either infralaminar hooks or sublaminar cables provided additional resistance to failure.

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.

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.

The reliability and diagnostic value of radiographic criteria in sagittal spine deformities: comparison of the vertebral wedge ratio to the segmental cobb angle

STUDY DESIGN

A prospective, radiographic cohort study.

OBJECTIVES

This study assessed the radiographic reliability and diagnostic value of the vertebral wedge ratio (WR) to the more segmental Cobb angle (CA) regarding sagittal spine deformities.

SUMMARY OF BACKGROUND DATA

The use of the CA has been used to assist in the radiographic diagnosis of various sagittal spine deformities. However, the reliability and diagnostic aptitude of the CA remains speculative and may not be as receptive to individual variations of vertebral integrity in sagittal spine deformities.

METHODS

Sixty patients (age range, 8-21 years) who were diagnosed with Scheuermann's kyphosis (Group 1; n = 16), with postural roundback (Group 2; n = 23), or who were regarded normal (Group 3; n = 21) were radiographically evaluated to assess the reliability and diagnostic potential of the vertebral WR (apex of the curve and 2 adjacent vertebrae) and segmental CA. Radiographic assessment was conducted by 3 independent blinded observers on 3 separate occasions.

RESULTS

Very strong intraobserver (WR a = 0.85-0.99; CA a = 0.97-0.99) and interobserver (WR a = 0.79-0.89; CA a = 0.95) reliabilities were noted. A greater degree of WR reliability was noted in Group 1, whereas CA reliability remained consistent in all Groups. A statistically significant difference was found between all Groups in relation to vertebral WR and segmental CA (P < 0.05). Based on relative risk ratio analyses, an apex wedge ratio of < or = 0.80 and/or a segmental Cobb angle of > or = 20 degrees is highly and significantly associated with Scheuermann's kyphosis.

CONCLUSION

The segmental CA exhibited a higher degree of reliability than the vertebral WR. The apex vertebral WR exhibited the greatest amount of wedging in the Scheuermann's patients; whereas in the other groups it remained largely consistent with the adjacent vertebral WRs. An apex vertebral WR < or = 0.80 and/or a segmental CA of > or = 20 degrees are highly associated with the clinical diagnosis of Scheuermann's kyphosis. If the segmental CA cannot be ascertained, the apex vertebral WR is a relatively strong reliable alternative, primarily with regards to Scheuermann's kyphosis. In addition, the type of deformity may potentially dictate the ideal measuring method.

Comparison of Scheuermann kyphosis correction by posterior-only thoracic pedicle screw fixation versus combined anterior/posterior fusion

STUDY DESIGN

Retrospective comparison review.

OBJECTIVE

Compare posterior-only treatment results with segmental thoracic pedicle screw constructs versus combined anterior/posterior fusion in patients with Scheuermann kyphosis.

SUMMARY OF BACKGROUND DATA

Traditionally, operative Scheuermann kyphosis has been treated with combined anterior/posterior spinal fusion, with the anterior portion being performed via an open thoracotomy or a video-assisted thoracoscopic approach.

METHODS

There were 18 patients with Scheuermann kyphosis who underwent a posterior-only thoracic pedicle screw (P/TPS) fusion and 21 who underwent an anterior/posterior fusion who were followed for a 2-year minimum. The 2 groups were well matched according to average age (anterior/posterior fusion 18.0 degrees and P/TPS 17.3 degrees; P = 0.60), maximum preoperative kyphosis (anterior/posterior fusion 89.1 degrees and P/TPS 84.4 degrees; P = 0.21), flexibility index (anterior/posterior fusion 0.408 degrees and P/TPS 0.407 degrees; P > 0.99), and posterior fusion levels (anterior/posterior fusion 12.1 degrees and P/TPS 12.2 degrees; P = 0.95). Of 21 patients with anterior/posterior fusions, zero versus 12 of 18 (67%) patients in the P/TPS group underwent apical Smith-Petersen osteotomies. Fixation in the anterior/posterior fusion group was achieved with hybrid hook/screw constructs. Posterior fixation in the P/TPS group was performed using segmental thoracic pedicle screw constructs. Both groups had posterior iliac bone autografting. Operating time and blood loss were noted, and radiographs were evaluated before surgery, after surgery, and at final follow-up. At final follow up, Scoliosis Research Society-30 questionnaire data and complications were recorded.

RESULTS

At surgery, operating time and blood loss were significantly less in the P/TPS group (P = 0.009 and P = 0.05, respectively). The mean residual kyphosis of the P/TPS group averaged 38.2 degrees after surgery and 40.4 degrees at final follow-up versus anterior/posterior fusion group (51.9 degrees and 58.0 degrees, P < 0.001 and P = 0.001, respectively). Even without an anterior release, kyphosis correction in the P/TPS group averaged 54.2% after surgery and 51.8% at final follow-up versus the anterior/posterior fusion group (41.2% and 38.5%, P = 0.001 and P < 0.001, respectively). Scoliosis Research Society-30 outcome scores at final follow-up were comparable between the 2 groups (P/TPS = 120 and anterior/posterior fusion = 128; P = 0.14). The anterior/posterior fusion group had 8/21 (38%) patients with complications, including paraplegia in 1, proximal junctional kyphosis in 1, proximal hook pullout in 1, and infection in 2. The P/TPS group had no complications (P = 0.003).

CONCLUSIONS

With less operating time and intraoperative blood loss, posterior-only Scheuermann kyphosis treatment with thoracic pedicle screws achieved and maintained better correction, and had significantly less complications than with circumferential fusion.

Do anterior interbody cages have a potential value in comparison to autogenous rib graft in the surgical management of Scheuermann's kyphosis?

BACKGROUND CONTEXT

Previous studies have analyzed the outcome following posterior correction and combined anterior-posterior correction for Scheuermann's kyphosis. Traditionally interbody fusion has been obtained using morselized rib graft. Recently the use of titanium anterior cages has been suggested for interbody use. There are no long-term studies comparing these two techniques.

PURPOSE

To investigate the potential value of titanium anterior interbody cages compared with morselized rib graft for anterior interbody fusion in combination with posterior instrumentation, correction, and fusion for Scheuermann's kyphosis.

STUDY DESIGN

Nonrandomized comparison of two surgical techniques in matched subjects.

PATIENT SAMPLE

Fifteen patients with identical preoperative radiographic and physical variables (age, gender, height, weight, body mass index) were managed with combined anterior release, interbody fusion, posterior instrumentation, correction, and fusion. Group A (n=8) had morselized rib graft inserted into each intervertebral disc space. Group B (n=7) had titanium interbody cages packed with bone graft inserted at each level. The posterior instrumentation extended from T2 to L2 in both groups.

OUTCOME MEASURES

Preoperative and postoperative curve morphometry was studied on plain radiographs by two independent observers. The indices studied included Cobb angle, Ferguson's angle, Voutsinas index, sagittal vertical axis (SVA), sacral inclination (SI), and lumbar lordosis (LL). Interbody fusion was assessed at final follow-up. Each patient was reviewed at 3, 6, 12, 24, 48, and 60 months after surgery with standing radiographs.

METHODS

Both surgical groups were compared in terms of radiological parameters and complications. Wilcoxon-matched pairs test and Mann-Whitney test were used.

RESULTS

The average follow-up for Group A was 70 months and for Group B 66 months. For the whole group, the preoperative median Cobb angle for thoracic kyphosis was 86 degrees , the median Ferguson angle was 50 degrees , Voutsinas index was 28.7, SVA -3.5 centimeters, lumbar lordosis was 66 degrees , and the median sacral inclination angle was 40 degrees . The median postoperative Cobb angle was 42 degrees , Ferguson angle 28.4 degrees , Voutsinas index 13, SVA -4.0 centimeters, and the median sacral inclination angle was 34 degrees . There were significant differences between preoperative and postoperative measurements for all variables (p<.01), indicating that good correction was achieved. At 4-year follow-up, fusion criteria were satisfied in 12 of 15 cases (80%). Three patients had distal junctional kyphosis. There was no significant difference obtained in the final Cobb angle, Ferguson angle, and Voutsinas index when Group A (rib graft) was compared with Group B (titanium cage) Both Group A and B patients retained the postoperative correction achieved with respect to all the radiographic parameters studied.

CONCLUSION

We were unable to demonstrate any significant advantage for the use of anterior titanium interbody cages over the use of morselized rib graft in the surgical management of Scheuermann's kyphosis. Given the not inconsiderable cost and the need for posterior chevron osteotomies when interbody cages are used, we have now reverted to our previous practice of using morselized rib graft at each intervertebral level.

Experience with combined video-assisted thoracoscopic surgery (VATS) anterior spinal release and posterior spinal fusion in Scheuermann's kyphosis

STUDY DESIGN

Retrospective.

OBJECTIVES

To determine whether anterior endoscopic release and posterior spinal fusion could achieve stable correction in Scheuermann's kyphosis.

SUMMARY OF BACKGROUND DATA

The initial treatment of choice of Scheuermann's kyphosis is thoracic hyperextension and postural exercises and/or Milwaukee brace. Milwaukee bracing is most efficacious in the early stages when the curvature is flexible and in the skeletally immature. However, it is known that larger curves, vertebral wedging greater than 10 degrees, and skeletally mature patients will not usually respond to this treatment. Surgery is indicated in the skeletally immature with severe deformity where brace treatment has failed to prevent progression. Posterior spinal instrumentation can achieve adequate correction in the less rigid curves. However, the more rigid curves have been shown to be resistant to posterior spinal fusion alone, therefore needing anterior spinal release.

METHODS

Between 1995 and 2001, 19 patients underwent video-assisted thoracoscopic surgery and posterior spinal fusion for the treatment of Scheuermann's kyphosis. The average age was 17.4 years with closed triradiate cartilage in all. Average follow-up was 2.7 years. An average of 8.3 discs were released anteriorly; an average of 13 levels were fused posteriorly.

RESULTS

Average preoperative kyphosis was 84.8 degrees. Average postoperative kyphosis was 43.7 degrees. Average kyphosis at follow-up was 45.3 degrees. Only 1.6 degrees of correction loss was noted. No junctional kyphosis was present. Two patients developed pleural effusion; one required thoracocentesis. Two patients developed pneumothorax. One patient underwent revision surgery for inferior hook pullout. One required mechanical ventilation.

CONCLUSIONS

Combined video-assisted thoracoscopic surgery release and posterior spinal fusion for the treatment of Scheuermann's kyphosis is a viable option for the treatment of the more severe and rigid curves.

Correction of adolescent hyperkyphosis with posterior-only threaded rod compression instrumentation: is anterior spinal fusion still necessary?

STUDY DESIGN

Retrospective clinical and radiographic review.

OBJECTIVE

To assess the need for anterior apical release and fusion before posterior threaded rod compression instrumentation and closing-wedge lamina resection for the treatment of adolescent hyperkyphosis.

SUMMARY OF BACKGROUND DATA

Traditional treatment of adolescent hyperkyphosis has included a preliminary anterior release and fusion of apical disc segments to achieve and maintain better correction.

METHODS

A total of 27 patients undergoing correction of adolescent hyperkyphosis with posterior threaded rod Texas Scottish Rite Hospital instrumentation was reviewed. Of the 27 patients, 19 had strict Sorensen criteria for Scheuermann kyphosis. There were 20 patients (group 1) who underwent posterior surgery only, while 7 (group 2) underwent same day preliminary open or endoscopic anterior release and fusion of 5-7 apical segments. A closing-wedge laminar resection was used to facilitate shortening of the posterior column. All but 2 patients were braced for up to 3 months after surgery. Preoperative, immediate postoperative, and final follow-up radiographs at 24-56 months postoperatively were analyzed for the amount and loss of correction of measured kyphosis, T2-T12 kyphosis, T10-L2 kyphosis, T12-S1 lordosis, C7 plumbline sagittal balance, and correction of Voutsinas index.

RESULTS

There was no difference in the amount of correction achieved at final follow-up between the 2 groups (group 1 = 53%, group 2 = 46%, P = 0.47). There was also no difference (P = 0.84) in the amount of correction immediately after surgery compared to final follow-up. No patient lost more than 8 degrees correction after surgery. One asymptomatic rod fracture occurred, with no loss of correction, implying no pseudarthroses. Similarly, there were no differences in any of the other sagittal plane measurements between the 2 groups, except for Voutsinas index (VI) in which group 1 patients had better normalization (VI = 0.11) compared to group 2 (VI = 0.15, P =0.05).

CONCLUSIONS

Traditional anterior/posterior fusion technique provides no additional improvement in radiographic outcome compared to posterior-only surgery for adolescent hyperkyphosis. Preliminary anterior release and fusion is no longer performed when correcting this deformity with a posterior column shortening procedure and threaded rod compression instrumentation.

Scheuermann’s kyphosis: surgical management

Indications for surgery in Scheuermann disease are not well codified and remain rare, as the natural history of the disease is in most cases benign. In the immature adolescent, conservative treatment, such as bracing or casting, can be tried for moderate curves. For larger curves, or in the adult, conservative treatment is usually not effective, and surgery can be considered. Such indications are mostly cosmetic for large curves above 75 degrees. Pain over the deformity or in the low back may represent another surgical indication, especially in the adult group. The question of anterior release or straight posterior fusion has become more of an actuality with the advent of powerful, third-generation stiff segmental instrumentation. However, the long-term results of a modern, posterior-only instrumentation fusion are not known. Concern about loss of correction, late pseudarthrosis or the need to remove instrumentation for infected hardware or due to late pain at the operative site must make us careful about choosing this method. Very rigid and large curves still require an anterior release, either done in a conventional or mini-open fashion, or through video-assisted thoracoscopic surgery. The extent of the posterior instrumentation has now been better defined. One must fuse the whole Cobb angle without hypercorrection and stop distally, above the first lordotic disc, to avoid sagittal decompensation. New approaches such as short anterior fusion with bone-on-bone techniques and pedicle substraction osteotomies have not yet been reported in the literature as having been used for treating Scheuermann's kyphosis. These should be considered experimental.

Scheuermann kyphosis: safe and effective surgical treatment using multisegmental instrumentation

STUDY DESIGN

A retrospective review was conducted on 23 consecutive patients who underwent surgical correction of Scheuermann kyphosis using modern multisegmental instrumentation.

OBJECTIVE

To evaluate Scheuermann kyphosis correction and complication rates.

SUMMARY OF BACKGROUND DATA

The surgical treatment of Scheuermann kyphosis remains a topic of debate. The literature of the 70s and 80s on the surgical management of this disorder using Harrington instrumentation demonstrated that operative correction is quite effective but associated with significant complications. This literature, however, may be less applicable to current clinical situations. The use of modern multisegmental instrumentation and increased awareness of potential complications may decrease the risks of current operative treatment.

METHODS

Hospital charts, office charts, and radiographs on 23 consecutive patients who underwent operative treatment using multisegmental instrumentation for Scheuermann kyphosis were reviewed to identify complications of surgery. Complications were classified as minor, major, or life threatening.

RESULTS

The mean follow-up was 38 months (range 10-123 months). Preoperative kyphosis ranged from 63 degrees to 104 degrees with an average of 83 degrees. Twenty of the 23 patients (87%) underwent combined anterior release/arthrodesis with posterior arthrodesis/multisegmental instrumentation. The remaining 3 patients underwent posterior arthrodesis/multisegmental instrumentation. Postoperative total kyphosis ranged from 32 degrees to 67 degrees with an average of 46 degrees. At final follow-up, the total kyphosis ranged from 37 degrees to 75 degrees with an average of 51 degrees. Overall, we had 43% minor complications, 17% major complications, and 0% life-threatening complications.

CONCLUSIONS

Surgical correction of Scheuermann kyphosis can be performed safely and effectively using modern multisegmental instrumentation.

Combined anterior–posterior fusion with laterally placed threaded interbody cages and pedicle screws for Scheuermann kyphosis

The authors report their preferred method for correcting Scheuermann disease via a combined anterior–posterior approach; their procedure is associated with a lower morbidity rate than the standard approach. Twenty-month follow-up examination demonstrated excellent maintenance of correction. The results satisfied the requirements to function without restriction in a vigorous military environment.

Analysis of the sagittal plane after surgical management for Scheuermann's disease: a view on overcorrection and the use of an anterior release

STUDY DESIGN

A historic cohort study was conducted to investigate surgical correction and sagittal alignment in 33 patients with thoracic Scheuermann's disease.

OBJECTIVE

To evaluate kyphosis correction, correction loss, sagittal balance, and the effect of an anterior release.

SUMMARY OF BACKGROUND DATA

Currently, both posterior and anteroposterior techniques seem to produce impressive corrections for Scheuermann's disease. However, few reports have been made on sagittal malalignment after surgery.

METHODS

A cohort of 33 patients who had undergone surgery for their Scheuermann's kyphosis were reviewed: Group A: posterior technique (n = 16), Group B: anteroposterior technique (n = 17). Pre- and postoperative curve morphometry (Cobb, Ferguson, Voutsinas), balance (C7 plumb line), and Oswestry score were compared.

RESULTS

The mean follow-up period was 4.5 +/- 2 years (range, 2-8.2 years). The mean preoperative kyphosis (Cobb) was 78.7 degrees +/- 8.9 degrees, and the mean postoperative kyphosis was 51.7 degrees +/- 10.3 degrees. At follow-up evaluation, the correction loss was 1,4 degrees +/- 3.9 degrees. There was no difference in curve morphometry, correction, sagittal balance, average age, and follow-up period between Groups A and B. One junctional kyphosis, in Group B, was noted. After surgery, all the patients were satisfied, and the Oswestry score showed significant improvement. No neurologic complications were observed.

CONCLUSIONS

Good follow-up results included a 100% follow-up rate, adequate corrections, little correction loss, lower Oswestry scores, and a high satisfaction rate in both groups. The anteroposterior treatment did not influence the curve morphometry more than posterior fusion only. In reducing postoperative sagittal malalignment, the authors believe that surgical management should aim at a correction within the high normal kyphosis range of 40 degrees to 50 degrees, consequently providing good results and, particularly in flexible adolescents and young adults, minimizing the necessity for an anterior release.

Scheuermann kyphosis: long-term follow-up

BACKGROUND CONTEXT

There is considerable controversy as to the optimal treatment of Scheuermann kyphosis. Proposed modalities have included exercise, bracing and surgery.

PURPOSE

The purpose of this study was to document the functional capacity and radiographic findings in adults who have been previously treated for Scheuermann kyphosis.

STUDY DESIGN

A cohort study of all patients with Scheuermann kyphosis treated in a single institution using three different treatment modalities: exercise and observation, Milwaukee bracing and surgical fusion using the Harrington Compression System.

PATIENT SAMPLE

Sixty-three patients were evaluated at a mean of 14 years after treatment (10 to 28 years).

OUTCOME MEASURES

Two different functional evaluation instruments were used. Radiographic evaluation was carried out in 38 patients (60%).

METHODS

Patient interviews were conducted using a specially designed questionnaire. Patients were then asked to undergo standing radiographs. Patients were divided into groups depending on the location of their kyphosis and the manner in which they had been treated. Standard statistical analysis was then carried out.

RESULTS

At time of follow-up evaluation there were no differences in marital status, general health, education level, work status, degree of pain and functional capacity between the various curve types, treatment modality and degree of curve. Patients treated by bracing or surgery did have improved self-image, which they attributed to their treatment. Patients with kyphotic curves exceeding 70 degrees at follow-up had an inferior functional result. At time of final follow-up there were no statistical differences in degree of kyphosis and mode of treatment.

CONCLUSIONS

By carefully selecting the appropriate treatment for patients with Scheuermann kyphosis on the basis of the patient's age, spinal deformity and the severity of back pain, it is possible to achieve a similar functional result at long-term follow-up. Despite different treatment protocols, patients with Scheuermann kyphosis tend to achieve a similar functional result at long-term follow-up.

Surgical treatment of Scheuermann's disease with segmental compression instrumentation

Twenty-one patients with Scheuermann's kyphosis had surgery for progressive kyphotic deformity of 50 degrees or greater. There were six adolescents, with a mean age of 15.6 years (range, 13-17 years) and 15 young adults, with a mean age of 25.4 years (range, 18-40 years). All patients had posterior spine arthrodesis with segmental compression instrumentation. Seven patients with rigid kyphosis had combined anterior and posterior spine arthrodesis. One patient died of superior mesenteric artery syndrome. In the group of 13 patients with posterior arthrodesis only, followup was 4.5 years. The mean preoperative thoracic kyphotic curve of 68.5 degrees improved to 40 degrees at latest review, with an average loss of correction of 5.75 degrees. Junctional kyphosis occurred in two patients with a short arthrodesis: one at the cephalad end and one at the caudal end of the fused kyphotic curve. In the second group of seven patients with combined anterior and posterior arthrodesis, followup was 6 years. The mean preoperative thoracic kyphotic curve of 86.3 degrees improved to 46.4 degrees at latest review, with an average loss of correction of 4.4 degrees. Overall, there was no postoperative neurologic deficit and no pseudarthrosis. Thus, posterior arthrodesis and segmental compression instrumentation seems to be effective for correcting and stabilizing kyphotic deformity in Scheuermann's disease. Despite a long operating time, this technique provided significant correction, avoiding the development of any secondary deformity in most patients. Combined anterior and posterior spine arthrodesis is recommended for rigid, more severe kyphotic deformities.

Biomechanics of long segment fixation: hook patterns and rod strain

This is an in vitro study of the mechanical effects of varying hook attachment patterns in long segment kyphotic deformity. In such cases, the optimal implant bulk, fatigue life, and construct rigidity to reliably achieve fusion are still unquantified. Rod strains were measured for multiple laminar hook patterns in a synthetic thoracic spine test bed. Stresses were calculated from strain data. The model displayed similar flexion bending stiffness to the thoracic spine. None of the hook patterns significantly changed overall construct stiffness. Greatest rod strains were seen when utilizing away-facing apical hooks. This model was too stiff to detect differences in construct stiffness. Nonetheless, rod stress analysis showed that for multisegment thoracic constructs, particularly with fixed kyphosis, minimizing apical hooks will minimize rod strain. If periapical hooks are necessary, orienting the hooks toward the apex will minimize rod strain.

The effects of hook pattern and kyphotic angulation on mechanical strength and apical rod strain in a long-segment posterior construct using a synthetic model

STUDY DESIGN

Synthetic spine models were used to compare the effects of hook pattern and kyphotic angulation on stiffness and rod strain in long-segment posterior spinal constructs.

OBJECTIVES

To examine the biomechanical effects of hook patterns and kyphotic angulation on long-segment posterior spinal constructs.

SUMMARY OF BACKGROUND DATA

Kyphotic deformities managed by increasing rod diameter and hence construct stiffness have shown decreased postoperative loss of correction and hardware complications. The biomechanical effects of hook pattern and kyphosis are unknown.

METHODS

Spine models of 0 degrees, 27 degrees 54 degrees sagittal contour, composed of polypropylene vertebral blocks and isoprene elastomer intervertebral spacers, representing T3-T12, were used for biomechanical testing of long-segment posterior spinal constructs. Models were instrumented with 6.35-mm titanium rods and one of the following hook configurations: 20-hook compression, 16-hook compression, 16-hook claw apex-empty,16-hook claw apex-full, or 8-hook claw. Construct stiffness and rod strain during axial compression were determined.

RESULTS

The compression-hook patterns provided at least a 45% increase in construct stiffness (P = 0.013)and a 22% decrease in rod strain (P < 0.0001) compared with those obtained with the claw-hook pattern with the best biomechanical performance. When analyzing all five hook patterns, there was a 19% decrease in construct stiffness and 27% increase in rod strain when progressing from straight alignment to 27 degrees of sagittal contour (P < 0.0001). Progressing from straight alignment to 54 degrees decreased construct stiffness by 48% and increased rod strain by 55% (P < 0.0001). Construct stiffness was inversely correlated to rod strain in all five hook patterns (R2 = 0.82-0.98, P < 0.001).

CONCLUSIONS

Using compressive-hook patterns and decreasing the kyphotic deformity significantly increases construct stiffness and decreases rod strain.

The effect of kyphosis on the mechanical strength of a long-segment posterior construct using a synthetic model

STUDY DESIGN

This experimental study used synthetic spine models to compare the effect of the angle of kyphosis, rod diameter, and hook number on the biomechanical stiffness of a long-segment posterior spinal construct.

OBJECTIVE

To examine the biomechanical effects of incremental kyphosis on variously instrumented long-segment posterior spinal constructs.

SUMMARY OF BACKGROUND DATA

Euler's formula for loading of curved long columns would suggest that kyphosis has a profound impact on the biomechanical behavior of long-segment posterior spinal constructs. The effects of sagittal contour on the mechanical properties of long-segment posterior spinal constructs have not been well documented.

METHODS

Kyphotic and straight synthetic spine models were used to test long-segment posterior instrumentation constructs biomechanically while varying rod diameter and the number of hook sites. The synthetic spines, composed of polypropylene vertebral blocks and isoprene elastomer intervertebral spacers, were fabricated with either 0 degrees, 27 degrees, or 53 degrees of sagittal contour. The models were instrumented with 5.5- or 6.35-mm titanium rods, and with either 8 or 12 hooks. The models were loaded from 0 to 300 N in a cyclical ramp fashion using an MTS 858 Bionix testing device testing device. Construct stiffness (force and displacement) during axial compression was determined.

RESULTS

Straight model: Changing the hook number from 8 to 12 caused a 32% increase in construct stiffness with the 5.5-mm rod. Changing the rod diameter from 5.5 to 6.35 mm caused a 36% increase in construct stiffness with the 8-hook pattern. Changing both the rods and hooks caused the stiffness to increase 44%. 27 degrees

MODEL

Changing the hook number from 8 to 12 caused a 20% increase in construct stiffness with the 6.5-mm rod. Changing the rod diameter from 5.5 to 6.35 mm caused a 29% increase in construct stiffness with the 12-hook pattern. Changing both the rods and hooks caused the construct stiffness to increase 26%. 53 degrees

MODEL

Changing the hook number from 8 to 12 caused a 14% increase in construct stiffness with the 6.35-mm rod. Changing the rod diameter from 5.5 to 6.35 mm caused a 17% (P<0.0005) increase in construct stiffness with the 12-hookpattern. Changing both rods and hooks caused the stiffness to increase 21%. Summary data on angular kyphosis: Using the same rod diameter and the same number of hooks, and progressing from a straight alignment to 27 degrees of sagittal contour decreased construct stiffness 32%. Going from straight alignment to 53 degrees decreased the stiffness 59.6%. All reported values were statistically significant (P < 0.0005).

CONCLUSIONS

The biomechanical stiffness of the straight spine was sensitive to both an increase in hook fixation sites and an increase in rod diameter. The kyphotic spines, however, were more sensitive to variations in rod diameter. Although with increasing kyphosis, the optimum instrumentation strategy will maximize both rod diameter and the number of hook sites, instrumented kyphotic spines remain biomechanically "disadvantaged" as compared with nonkyphotic instrumented spines.

Scheuermann's disease

Scheuermann's disease is the most common cause of structural kyphosis in adolescence. The mode of inheritance is likely autosomal dominant and the etiology remains largely unknown. Indications for treatment remain controversial because the true natural history of the disease has not been clearly defined. Brace treatment appears to be very effective if the diagnosis is made early. Surgical treatment is rarely indicated for severe kyphosis (> 75 degrees ) with curve progression, refractory pain, or neurologic deficit.