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.

Assessment of Quality of Life for Scheuermann's Kyphosis Patients with Cobb's Angle 50°-65° Treated Conservatively or Surgically in North Jordan: A Prospective Comparative Study.

Background: Scheuermann's disease is the most common cause of hyperkyphosis of the thoracic spine during the adolescence period. It causes neck and lower back pain, restriction of lung expansion, traction of the spinal cord, increased vulnerability to vertebral fracture, and a hump. Patients with curves < 60° are treated conservatively, while surgery is used for patients with curves > 60°. The purpose of this prospective cohort study was to assess the quality of life and functional changes in conservatively or surgically treated Scheuermann's disease patients with a curve size of 50°-65° in north Jordan. Methods: Sixty-three adolescent patients with Scheuermann's kyphosis (aged between 10 and 18 years) were treated at our hospital between January 2014 and August 2018. All patients were investigated clinically, radiologically (Cobb's angle), and functionally (Oswestry Disability Index [ODI], Scoliosis Research Society 22 revision [SRS-22r] questionnaire, and pulmonary function test [PFT]) pre- and post-treatment (final follow-up). Patients were randomly selected for treatment method (conservative versus surgical). Results: There were 31 patients (mean age, 15.48 ± 2.50 years) and 32 patients (mean age, 16.19 ± 1.51 years) treated conservatively and surgically, respectively. Mean ± standard deviation of ODI, SRS-22r, and Cobb's angle of the surgical group improved from 16.8% ± 14.3%, 3.5 ± 0.5, and 58.75° ± 3.59°, respectively, pre-surgery to 13.4% ± 10.8%, 4.2 ± 0.5, and 41.53° ± 3.94°, respectively, post-surgery, while those of the conservative group became worse from 12.6% ± 13.4%, 3.9 ± 0.7, and 56.1° ± 3.3°, respectively, to 20.1% ± 13.6%, 3.5 ± 0.7, and 58.8° ± 5.8°, respectively. The surgical group showed better improvement in all scores than the conservative group (p < 0.05), as well as in PFT. Conclusions: Surgical treatment of Scheuermann's kyphosis with curves of 50°-65° resulted in better QOL, Cobb's angle, and PFT than conservative treatment. This was because of lower patient cooperation in the conservative management group, which made the curve less flexible for exercises and bracing.

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.

Major complications following surgical correction of spine deformity in 257 patients with cerebral palsy.

STUDY DESIGN: Observational. OBJECTIVES: To report on the rate of major complications following spinal fusion and instrumentation to treat spinal deformity in patients with cerebral palsy (CP). Understanding the risk of major complications following the surgical treatment of spine deformities in patients with CP is critical. METHODS: A prospectively collected, multicenter database of patients with CP who had surgical correction of their spinal deformity (scoliosis or kyphosis) was reviewed for all major complications. Patients with ≥ 2 year follow-up or who died ≤ 2 years of surgery were included. A complication was defined as major if it resulted in reoperation, re-admission to the hospital, prolongation of the hospital stay, was considered life-threatening, or resulted in residual disability. Overall complication and revision rates were calculated for the perioperative (Peri-op; occurring ≤ 90 days postoperative) and delayed postoperative (Delayed; > 90 days) time periods. RESULTS: Two hundred and fifty-seven patients met inclusion. Seventy-eight (30%) patients had a major complication, 18 (7%) had > 1. There were 92 (36%) major complications; 64 (24.9%) occurred Peri-op. The most common Peri-op complications were wound (n = 16, 6.2%) and pulmonary issues (n = 28, 10.9%), specifically deep infections (n = 12, 4.7%) and prolonged ventilator support (n = 21, 8.2%). Delayed complications (n = 28, 10.9%) were primarily deep infections (n = 8, 3.1%) and instrumentation-related (n = 6, 2.3%). There were 42 additional surgeries for an overall unplanned return to the operating room rate of 16% (Peri-op: 8.6%, Delayed: 7.8%). Thirty-six (14.0%) reoperations were spine related surgeries (wound or instrumentation-related). Eleven (4.3%) patients died between 3 months to 5.6 years postoperatively; 4 occurred ≤ 1 year of surgery. Two deaths were directly related to the spinal deformity surgery. CONCLUSION: Spinal deformity surgery in CP patients with greater than 2 years of follow-up have a postoperative major complication rate of 36% with a spine-related reoperation rate of 14.0%. LEVEL OF EVIDENCE: Therapeutic-IV.

Surgical strategy for correction of severe, rigid, post-tubercular cervical kyphosis: an experience of two cases.

STUDY DESIGN: Case series. OBJECTIVES: To describe a novel surgical strategy for severe, rigid post-tubercular cervical kyphosis with treatment outcomes in two patients. BACKGROUND DATA: Spinal tuberculosis is a common cause of kyphotic deformity in the developing world with 3-5% of non-operatively managed patients ending up with kyphosis exceeding 60°. Ventral, dorsal and combined approaches have been described for cervical kyphosis, but there is no established surgical strategy for severe, rigid post-tubercular cervical kyphosis. METHODS: We operated on two girls with severe, rigid cervical kyphosis with preoperative kyphosis measuring 98° and 62°. Our surgical strategy included a three-step approach in the same sitting-(1) An anterior approach to osteotomize the fused vertebral body mass, decompress the spinal cord ventrally and place a temporary cage to stabilize the spine, (2) A posterior approach to osteotomize the fused facets and decompress the cord dorsally. With the completion of the osteotomy, a combination of pedicle screws and lateral mass screws was used to correct the deformity via an anterior opening, posterior closing type of osteotomy. This was followed by, (3) An anterior approach to replace the corpectomy cage with a larger one supplemented with an anterior cervical plate. RESULTS: Our 540° approach achieved a substantial improvement in each of the clinical and radiological parameters we measured, viz. C2-C7 lordosis angle, C2-C7 sagittal vertical axis, neck tilt and Neck Disability Index. CONCLUSION: For severe, rigid post-tubercular cervical spine kyphosis, a three-step, anterior-posterior-anterior procedure can be used for achieving acceptable correction, improving symptoms and avoiding further progression. LEVEL OF EVIDENCE: IV.

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.

Global Sagittal Alignment and Proximal Junctional Kyphosis in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Case-control study. OBJECTIVES: To analyse global sagittal alignment including the cranial center of mass (CCOM) and proximal junctional kyphosis (PJK) in adolescent idiopathic scoliosis (AIS) patients treated with posterior instrumentation. SUMMARY OF BACKGROUND DATA: PJK plays an important role in the global sagittal alignment in AIS patients. Maintaining the head above the pelvis allows for a minimization of energy expense in ambulation and upright posture. Numerous studies have been performed to understand the PJK phenomena in AIS patients. However, to our knowledge, no study performed on AIS patients included the head in the analysis of global sagittal alignment and PJK. METHODS: This study included 85 AIS patients and 51 asymptomatic adolescents. Low-dose bi-planar radiographs were acquired for each subject preoperatively and at the two-year follow-up. Two global sagittal alignment parameters were calculated, that is, the angle between the vertical and the line joining the center of the bi-coxofemoral axis (HA) and either the most superior point of the dentiform apophysis of C2 (OD) or the cranial center of mass (CCOM). RESULTS: Among normal adolescents, the average OD-HA and CCOM-HA angles were -2.3° ± 2° and -1.5° ± 1.8°, respectively. Among AIS patients, the average OD-HA and CCOM-HA angles were, respectively, -2.3° ± 1.9° and -1.3° ± 1.8° preoperatively and -2.8° ± 1.7° and -1.9° ± 1.7° at the last follow-up. Overall, 13% of the patients developed PJK postoperatively. Case-by-case analysis showed that adjusting the thoracic kyphosis and the compensations required to maintain this constant could provide explanatory elements. CONCLUSIONS: OD-HA and CCOM-HA angles remain almost constant among the normal group and patients, pre- and postoperatively, whether PJK or non-PJK. Five patients without PJK and only one patient with PJK produced abnormal values relative to the asymptomatic subjects. Therefore, it could be concluded that PJK is a compensation mechanism, which allows for CCOM-HA and, to a lesser extent, OD-HA to remain invariant. LEVEL OF EVIDENCE: Level III.

Scheuermann's Kyphosis: Diagnosis, Management, and Selecting Fusion Levels.

Scheuermann's kyphosis (SK) is a rigid structural deformity of the thoracic spine defined radiographically as three or more contiguous vertebrae with at least 5° of wedging anteriorly. Prevalence of the disease is thought to be between 0.4% and 10%. The true cause of SK remains unclear; however, various theories include growth irregularities, mechanical factors, genetic factors, and/or poor bone quality as the causes. Patients with mild disease (less than 70°) generally have a favorable prognosis with good clinical outcomes. Most patients with SK are successfully treated nonsurgically with observation, anti-inflammatory medications, and physical therapy. Surgical intervention is indicated in patients with greater than 70° to 75° thoracic curves, greater than 25° to 30° thoracolumbar curves, intractable pain, neurologic deficit, cardiopulmonary compromise, or poor cosmesis. Because of advances in posterior spinal instrumentation, surgery can typically be performed through a posterior-only approach. When surgical treatment is planned, appropriate selection of the upper- and lower-instrumented vertebrae is important to achieve a well-balanced spine, preserve motion segments, and reduce the risk of junctional kyphosis.

Modified pedicle subtraction osteotomies (mPSO) for thoracolumbar post-tubercular kyphosis in pediatric patients: retrospective clinical cases and review of the literature.

PURPOSE: The purpose of this study was to evaluate the clinical and radiographic outcomes of modified pedicle subtraction osteotomy (mPSO) for thoracolumbar post-tubercular kyphosis in pediatric patients. METHODS: From January 2008 to August 2012, 26 consecutive pediatric patients with thoracolumbar post-tubercular kyphosis underwent modified pedicle subtraction osteotomy (mPSO). The clinical and radiologic outcomes were analyzed preoperatively, postoperatively, and at the last follow-up. RESULTS: Twenty-six patients with thoracolumbar post-tubercular kyphosis underwent mPSO. The average operation time was 256 min (188~314 min). The mean follow-up was 41 months (18~56 months). The mean estimated blood loss was 870 ml (620 ~ 1020 ml). The thoracolumbar kyphotic angle ranged from 51° to 79° before operation, 60.6° in average. The mean thoracolumbar kyphotic Cobb angle was 19.7° after operation, with a mean correction of 40.9°. The C7 sagittal plumb line was 3.8 cm after operation, comparing to the 10.5 cm preoperative. The mean preoperative angle of thoracic kyphosis (TK) was 9.9° ± 1.2° and increased to 11.8° ± 1.4°, postoperatively. Lumbar lordosis (LL) improved from -22.8° ± 4.9° preoperative to -17.8° ± 2.1° postoperative. Visual analogue scale (VAS) was 8.7 ± 1.1 preoperative and 1.2 ± 0.4 postoperative, respectively. The mean Oswestry Disability Index (ODI) improved from 49.2 ± 5.3 before surgery to 10.8 ± 3.3 postoperative (P < 0.01). All patients received good bone healing, no significant loss of correction angle. Most patients (24/26) considered pain and exterior was significantly improved. CONCLUSION: Modified pedicle subtraction osteotomy (mPSO) is effective and reliable for thoracolumbar post-tubercular kyphosis in pediatric patients.

Hypothesis about an existent biomechanical cause-effect relationship between Schëuermann's kyphosis and scoliosis.

Schëuermanns kyphosis is usually observed with a mild idiopathic scoliosis, and there is parity between these two diseases. The aim of this work is to establish a hypothesis about the existence of a biomechanical causal relationship between Schëuermann's kyphosis and scoliosis. To achieve this, a literature review was conducted. A simple mechanical model of the passive thoracolumbar subsystem was created to support part of the discussion. This mechanical model describes the passive thoracolumbar subsystem under ideal conditions of equilibrium. After giving consideration to the system under these conditions, some of the geometrical changes that may be found in Schëuermanns kyphosis are considered. Next, this work discusses the evolution of the spine, taking into account its relationship with stable equilibrium, which the passive subsystem tends toward. We hypothesized about the postural response of the body to compensate for possible situations of imbalance. In conclusion, it can be found that a change in the alignment of the spine may occur due to the postural adaptation of the body to an inadequate mechanical situation that may lead to scoliotic deformity of the spine.

Scheuermann's disease: current diagnosis and treatment approach.

OBJECTIVES: To summarize the current knowledge relating to diagnosing and treating Scheuermann's disease. Scheuermann's disease is the most common cause of structural kyphosis in adolescence. METHODS: A literature-based narrative review of English language medical literature. RESULTS AND CONCLUSIONS: Recent studies have revealed a major genetic contribution (a dominant autosomal inheritance pattern with high penetrance and variable expressivity) to the etiology of Scheuermann kyphosis with a smaller environmental component (most probably mechanical factors). The natural history of Scheuermann kyphosis remains controversial, with conflicting reports as to the severity of pain and physical disability. Since we cannot predict which kyphotic curves will progress, we are unable to determine effectiveness of brace treatment. Physical therapy is scarcely mentioned in the literature as an effective treatment for Scheuermann kyphosis. Although there is little evidence that physical therapy alone can alter the natural history of Scheuermann's disease, it is often used as the first choice of treatment. Brace treatment appears to be more effective if an early diagnosis is made, prior to the curvature angle exceeding 50° in patients continuing to grow. Surgical treatment is rarely indicated for severe kyphosis (>75°) with curve progression, refractory pain, or a neurologic deficit. Rigorous methodology clinical trials are essential to evaluate the efficacy of conservative interventions, especially different exercises and manual therapies and their combinations with braces.

Spina bifida occulta in high grade spondylolisthesis.

A 14-year-old boy presented with symptomatic high-grade dysplastic type spondylolisthesis, with a presence of spina bifida occulta, not diagnosed by plain radiographs, but confirmed on preoperative CT and MR. Circumferential fusion with partial reduction of L5/S1 was performed. Awareness of the coexistence of spondylolisthesis and spina bifida by an accurate preoperative planning is paramount to avoid iatrogenic damage to neural elements during surgery.

Rapidly progressive Scheuermann's disease in an adolescent after pectus bar placement treated with posterior vertebral-column resection: case report and review of the literature.

STUDY DESIGN: Case report and review of the literature. OBJECTIVE: This case illustrates the importance of the costosternal complex in maintaining the stability and alignment of the thoracic spine. The patient was iatrogenically destabilized by placement of a pectus bar leading to rapid symptomatic progression of his Scheuermann's kyphosis, ultimately requiring surgical correction. SUMMARY OF BACKGROUND DATA: Scheuermann's kyphosis is a disease process defined by strict radiographical and clinical criteria. Surgical treatment is generally recommended for curves greater than 75°. This case demonstrates the critical role of the costosternal complex in maintaining the stability of the thoracic spine. The patient described in this report underwent placement of a pectus bar for correction of symptomatic pectus excavatum. He subsequently developed a progressive symptomatic Scheuermann's kyphosis as a result of the destabilization of his costosternal complex. This patient ultimately required removal of the pectus bar and posterior instrumented kyphosis correction. METHODS: Progressive symptomatic Scheuermann's kyphosis (105°) corrected by removal of the pectus bar, T11 posterior vertebral-column resection and T4-L3 instrumented posterior spinal fusion. RESULTS: The patient had an uneventful immediate postoperative course. He was discharged neurologically intact with dramatic kyphosis correction and significant symptomatic improvement. Radiographs obtained 3 years postoperatively reveal stable thoracolumbar correction. CONCLUSION: The costosternal complex plays a critically important role in the intrinsic stability of the thoracic spine. Iatrogenic disruption of the costosternal complex can result in rapid progression of thoracic/thoracolumbar kyphosis in the setting of Scheuermann's disease.

Scheuermann kyphosis in nonhuman primates.

STUDY DESIGN: A cadaveric survey of the thoracic spines of extant species of nonbipedal primates for the presence of Scheuermann kyphosis. OBJECTIVE: To determine the presence and prevalence of Scheuermann kyphosis in quadrupedal species of the closest living relatives to humans to demonstrate that bipedalism is not an absolute requirement for the development of Scheuermann kyphosis. SUMMARY OF BACKGROUND DATA: The etiology of Scheuermann kyphosis remains poorly understood. Biomechanical factors associated with upright posture are thought to play a role in the development of the disorder. To date, Scheuermann kyphosis has been described only in humans and extinct species of bipedal hominids. METHODS: Thoracic vertebrae from 92 specimens of Pan troglodytes (chimpanzee) and 105 specimens of Gorilla gorilla (gorilla) from the Hamann-Todd Osteological Collection at the Cleveland Museum of Natural History were examined for Scheuermann kyphosis on the basis of Sorenson criteria and the presence of anterior vertebral body extensions and for the presence of Schmorl nodes. RESULTS: Two specimens of P. troglodytes (2.2%) were found to have anatomic features consistent with Scheuermann kyphosis including vertebral body wedging greater than 5° at 3 or more adjacent levels and the presence of anterior vertebral body extensions. One of the affected specimens (50%) demonstrated the presence of Schmorl nodes whereas 2 of the unaffected specimens (2.2%) had Schmorl nodes. None of the specimens of G. gorilla (0%) were found to have anterior vertebral body extensions characteristic of Scheuermann kyphosis or Schmorl nodes. CONCLUSION: Thoracic kyphotic deformity consistent with Scheuermann kyphosis exists in quadrupedal nonhuman primates. Bipedalism is not a strict requirement for the development of Scheuermann kyphosis, and the evolutionary origins of the disease predate the vertebral adaptations of bipedal locomotion.

Adult Scheuermann kyphosis: evaluation, management, and new developments.

Scheuermann kyphosis is a structural hyperkyphosis defined radiographically as anterior wedging of ≥5° of at least three consecutive vertebral bodies. Typically, the disease develops during adolescence but may not present until adulthood. The etiology remains unknown. Indications for management include progressive deformity, pain, cosmesis, neurologic deficit, and cardiopulmonary compromise. Surgical intervention is indicated in patients with persistent pain and unacceptable deformity caused by significant kyphosis. Surgery can be performed through posterior-only, anterior-only, or combined anterior-posterior approaches. Correction should include the entire length of the kyphosis and should not exceed 50% of the original deformity. The most common postoperative complications are wound infection and loss of correction.

[Postural kyphosis and morbus Scheuermann]. / Postural kyfose og morbus Scheuermann.

Scheuermann's kyphosis is the most frequent structural kyphosis in adolescents. There are gaps in the knowledge of epidemiology, aetiology and treatment. There are strong genetic and mechanical factors in the aetiology. Treatment options depend on the cobb's angle measured and the skeletal maturity. Training and brace treatment yield good results for milder curves, while surgical correction is the most effective for severe curves > 70°. Indications for surgery are subject of debate as complications are not uncommon.

[Current concepts on Scheuermann kyphosis: clinical presentation, diagnosis and controversies around treatment]. / Conceptos actuales sobre la enfermedad de Scheuermann: presentación clínica, diagnóstico y controversias sobre su tratamiento.

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.

Genetic epidemiology of Scheuermann's disease.

BACKGROUND AND PURPOSE: The genetic/environmental etiology of Scheuermann's disease is unclear. We estimated the heritability of the disease using an etiological model adjusted for sex and time of diagnosis, and examined whether the prevalence of Scheuermann's disease was constant over time. METHODS: 46,418 twins were sent a questionnaire about health and disease. Of these, 75% returned the questionnaire and 97% answered the question "Have you been diagnosed as having Scheuermann's disease by a doctor?" RESULTS: Responders included 11,436 complete pairs of twins. Data were analysed using classical twin modeling methods. Tetrachoric correlations were used to decide which etiological model to fit. The best-fitting model was the AE model. Heritability was 0.74 (95% CI: 0.65-0.81), while variance explained by environmental factors was 0.26 (95% CI: 0.19-0.35). A threshold of 2.1 (95% CI: 1.9-2.2) was calculated, corresponding to a prevalence of 1.9% (95% CI: 1.3-2.8) for women. Regression coefficients for age and sex were 0.000 (95% CI: -0.003 to 0.002) and -0.32 (95% CI: -0.42 to -0.23). INTERPRETATION: We found a heritability of 0.74 in Scheuermann's disease. The threshold in men was lower than in women, corresponding to a male prevalence that was almost twice that of females. We found no change in the prevalence of Scheuermann's disease throughout the 50-year age span that we examined.

Weakness of the neck extensors, possible causes and relation to adolescent idiopathic cervical kyphosis.

Cervical kyphosis may be congenital, or occur as a result of laminectomy, post-traumatic deformity, infection, neuromuscular disorders such as muscular dystrophies, motor neuron disorders such as amyotrophic lateral sclerosis, tumor, and inflammation such as ankylosing spondylitis. Furthermore, adolescent idiopathic cervical kyphosis was defined as cervical kyphotic deformity of adolescent patient without any cause such as those previously described. As no standard values for "cervical kyphosis" could be found in the literature, many reported studies only report a subjective classification, "kyphotic, straight or lordotic". But this method had proven to be unreliable. Grob et al. defined "straight" for the global curvature as +4° to -4°, and lordotic and kyphotic as <-4° and >+4°, respectively. The etiology and pathogenesis of adolescent idiopathic cervical kyphosis remain little understood. Weakness of the neck extensors can result in "dropped head syndrome", a rare disorder characterized by weakness of neck extensor muscles causing an inability to extend the neck and resulting in a chin-on-chest deformity. The purpose of this paper is to propose a possible mechanical cause leading to the kyphotic deformity. We hypothesize that weakness of the neck extensors could be the initiating factor for adolescent idiopathic cervical kyphosis.

Back pain in the young athlete.

Back pain in the young athlete is a common finding. There are many different problems that can cause back pain in active children. It is important for the treating physician to obtain a thorough history and physical examination to help in establishing the underlying cause for the discomfort. Appropriate imaging can be determined by these findings and further help to define the pathology. Depending upon the specific pathology, appropriate treatment may help the patient to safely return to the activities that they enjoy.