Objective. To compare the radiological and clinical outcomes following three different techniques used in the correction of Scheuermann's kyphosis. Materials and Methods. Twenty three patients with comparable preoperative radiographic and physical variables (age, gender, height, weight, body mass index) underwent correction of thoracic kyphotic deformity using three different surgical methods. Group A (n=8) had combined anterior and posterior fusion with instrumentation using morselised rib graft. Group B (n=7) had combined anterior and posterior fusion with instrumentation using titanium interbody cages. Group C (n=8) had posterior segmental pedicle screw fixation only. All groups had posterior apical multi-level chevron osteotomy and posterior instrumentation extending from T2 to L2/3. Preoperative and postoperative curve morphometry studied on plain radiographs included Cobb angle, sagittal vertical axis (SVA), sacral inclination (SI) and lumbar lordosis (LL). Preoperative and postoperative questionnaires including ODI, VAS and SRS-22 were also analysed. Results. The average follow-up was 70 months for group A, 66 months for group B and 35 months for group C. For the whole cohort, the preoperative median cobb angle for thoracic Kyphosis was 88.4°, SVA +3.5 centimeters (cms), lumbar lordosis was 66 °, and the median sacral inclination angle was 40°. The average immediate postoperative cobb angle for thoracic kyphosis was 42°, SVA -1.5 cms, lumbar lordosis 45 ° and sacral inclination angle was 30°. At follow-up, the average cobb angle for thoracic kyphosis was 42.0°, SVA +1 cm, lumbar lordosis 42.0 ° and sacral inclination angle was 22.0 °. There was a significant difference between preoperative and postoperative measurements in all three groups, indicating that good correction and satisfaction was achieved. Three patients had distal junctional Kyphosis in early cases. There was no significant difference obtained in the final cobb angle between group A, group B and group C. All three groups retained the postoperative correction with respect to thoracic kyphosis, and changes in ODI and SRS-22 scores were similar in three groups. Conclusion. In all groups the SVA became negative following correction and at long-term follow-up it was observed to return towards normal physiological limits. The compensatory lumbar curve reduces and this was associated with a decrease in sacral inclination. This method of compensation, without causing junctional kyphosis, has not previously been reported. We were unable to demonstrate a significant difference between the three groups with regards to the clinical outcome, the degree of initial correction, loss of correction and complications. Therefore, in conclusion, we believe a single stage posterior correction and segmental instrumentation not only provides the same clinical and radiological outcomes, but also reduces blood loss, operative time and hospital stay. Ethics approval: None. Interest Statement: None

Introduction:. Scheuermann's kyphosis is a fixed round back deformity characterised by wedged vertebrae seen on radiograph. It is known patients presented with a negative sagittal balance before operation. Few studies investigated the outcome after operation, especially the change in the lumbar hyperlordosis. Aim:. To investigate the change in sagittal profile after correction surgery. Method:. This is a retrospective review of cases from 2001 to 2012. Our centre uses a posterior, four rod cantilever reduction technique for all Scheuermann's Kyphosis correction. 36 cases are identified. They include 24 males and 12 females with an average age of 20 and follow up of 27 months. First 8 cases used the stainless steel hybrid implants. The remaining 28 had titanium all pedicle screw system. All had intra-operative spinal cord monitoring. Results:. The target of thoracic kyphosis correction is around the accepted upper end of normal limit (40°). The average thoracic kyphosis Cobb angle was 78.5°. The immediate post-op angle was 43.2° and at final follow up, 43.6°. The average lumbar lordosis changed from 65.7° pre-op to 48.8° post-op, which is now bigger than the thoracic kyphosis. The result is the transfer of average sagittal balance (C7 plumb line) from −2.2 cm to −3.5 cm, which remains posterior to the posterior corner of S1 after the surgery. Discussion:. Surgery can improve the roundback deformity but not the overall sagittal profile. We have no explanation to this phenomenon. This could imply the pathology of Scheuermann's Kyphosis involves the whole spine, not just the wedging thoracic segment. Conflict Of Interest Statement: No conflict of interest

1. Kyphosis and kyphoscoliosis associated with myelomeningocele are discussed. 2. It is suggested that the condition be treated by osteotomy of the spine, with removal of one or more vertebral bodies. 3. Sixteen patients treated by this method of spinal osteotomy are presented. 4. Although almost a third of the patients died, a high operative and post-operative mortality in this condition is considered acceptable

Lumbar Degenerative Kyphosis (LDK) is a clinical entity showing kyphosis in the lumbar spine in elderly with multilevel disc narrowing and a varied degree of osteoporosis. LDK patient complains of stooped gait with persistent low back pain and weakness. Purpose of this paper is to study the lumbar muscle in LDK patients with histopathologic and biophysical evaluations to investigate the pathogenesis. Materials and Methods: 1. Intramuscular pressure (IMP) (a) of the lumbar extensor compartment and hemoglobin content (Hb)□@(b) of 25 young volunteers were also investigated comparing in standing upright and flexion positions using (a)□@pressure monitoring kits and an non-invasive oxygenation monitor. 2.Muscle biopsy specimens obtained from the lumbar extensors of 9 LDK patients were histopathologically examined with HE, cytochrome c oxidase and other methods. These data were compared with muscles taken from age-match controls. Mitochondria function was also examined on biochemistry. 1. IMP of the extensors markedly increased in the flexion position (130.0□}45.4 in males and 86.3 mmHg in fem.) comparing to straight upright□@(22.8□}14.4, 17.0□}6.0). Oxy-Hb concentration decreased from 100% to 92.9, 95.5 % respectively in flexion, which was a sign of ischemia. 2. Both multifidus and sacrospinalis m. showed moderate to marked interstitial fibrosis, decreased number of muscle fibers and decreased stain intensity of cytochrome c oxidase. These finding were similar to those seen in repeatedly compressed muscles of an animal model of the chronic compartment syndrome. In comparison the rectus abd. and psoas muscles in the patients showed almost normal except for some aging changes. Conclusion: There appeared to be definite atrophy of the lumbar extensor muscles with histochemical and biochemical methods in LDK patients, whereas the flexors showed no change. This extensor atrophy is limited in the lumbar region in LDK. These localized atrophy of the lumbar extensors would suggest a result of high IMP during working in deep bending position of the spine for many years and may play important role in etiology of this disease condition

Patients with Lumbar Degenerative Kyphosis and Kyphoscoliosis (LDK) complain of stooped gait, persistent low back pain and weakness. Because operative treatment of LDK imposes considerable operative intervention for aged patients, an indication should be strictly limited; those have severe low back pain with lumbar kyphosis which afflicts upright walking disturbing house keeping, patients aged less than 70 as a rule and have no critical general complication as well. Purpose of this paper is to compare factors that affect the results of operative treatment of LDK. 19 patients were reviewed retrospectively in these series (av. aged 62.7, all female except one), who were followed-up for 3.0 years in average (14 months-8 years.) after the last surgery. Number of fused vertebra comprised 3 in 4 cases, 4 in 5, 5 in 3, 6 in 2, 7 in 2, 8 in 1, 9 in 2 respectively. In these cases 8 (av. aged 60.4) had no interbody fusion at all, one segment in one, 2 segments in 4, and 3 and more in 6 either anterior or posteriorly. Results were evaluated as excellent, good, fair and poor based on a correction rates of C7 plumb line and T1 tilt angle, as well as correction of lumbar kyphosis angle. The result was evaluated as excellent in 2 cases, good in 6, fair in 6 poor in 5. No co-relation was found between the results and number of fused vertebra at the last stage. However, patients whose operation include interbody fusion (IBF) of 3 and more contiguous segments showed either excellent or good, but all cases with single segment or no IBF groop showed either poor or fair, where those with 2 segments had good in 2 cases and fair in 2 respectively. There were relatively many poor results due to instrument failures (6 cases), insufficient correction of the deformity, compression fracture and increase of kyphosis above and below IBF level, possibly caused by progression of osteoporosis and degeneration. Four patients were found nerve root symptom after surgery, but almost healed by revision in several weeks. In order to obtain good result correction should include interbody fusion of at least 3 contiguous lumbar segments for multilevel anterior support and rigid instrumentation in sufficient length. Accurate planning before operation and careful surgical procedure should be emphasized to avoid nerve entrapment and instrument failure

The current trend in kyphosis correction is for “every level” instrumentation to achieve intraoperative stability, correction, fusion and implant longevity. We evaluate the medium term follow up of a low implant density (LID) construct. All patients with adolescent kyphosis (idiopathic or Scheurmann's) on our deformity database were identified. Radiographs and records were analysed for neurological complications, correction and revision. The constructs included were all pedicle screw anchors with multiple apical chevron osteotomies and a proximal and distal “box” of 6 to 8 screws. A four rod cantilever reduction manoeuvre with side to side connectors completed the construct. Kyphosis for any other cause was excluded. Follow up less than 12 months was excluded. 23 patients were identified with an average follow up 27 months (72 to 12 months) and a mean implant density of 1.1 (53.5% of “available” pedicles instrumented). There was 1 false positive neurophysiological event without sequelae (4%). There were no proximal junctional failures (0%). There were no pseudarthroses or rod breakages (0%). There was 1 loss of distal rod capture (early set screw failure) (4%). This was revised uneventfully. There were 4 infections requiring debridement (early series). Average initial correction was 44% (77.7 degrees to 43.5 degrees) with a 1% loss of correction at final follow up (43.5 to 44.0 degrees). The fulcrum bending correction index was 107% (based on fulcrum extension radiographs). 85% of curves had a fulcrum flexibility of less than 50%. The average cost saving compared to “every level “instrumentation was £5700 per case. This paper shows that a LID construct for kyphosis has technical outcomes as good as high density constructs. The obvious limitation of the study is the small number of patients in the cohort. The infection rates have improved with changes to perioperative process in the later series of patients. We do not believe these are a consequence of the construct itself

Introduction: Cervical kyphosis is failure of posterior osteo-ligamento-muscular restraint secondary to a deficient anterior column. Prospective studies of stand-alone anterior construct in correction and maintainence of cervical column that would otherwise require combined ant & post surgeries is sparse. Objectives: To evaluate the role of stand-alone anterior surgery for cervical kyphosis, determine its efficacy and analyse complications. Methods: 42 consecutive patients aged 6 – 70 yrs (Av 31.4 yrs) who had a Kyphosis angle of more than 100 with its apex between lower end-plate of C2 and C7 on a lateral x-ray and underwent anterior only surgery for cervical kyphosis over 6 yrs (2000–06) formed the population for this prospective study. The average follow-up was 2.2 yrs (1 – 5 yrs). The mean pre-op kyphosis was 20.820 (100 – 780). Etiology was tuberculosis in 25, dysplasia in 7, trauma in 6 and tumors in 4 cases respectively. 39 of the 42 patients had myelopathic signs. Mean pre-op mJOA score was 7.4 (0–11). A left anterior cervical approach was used in all cases. Modified manubriotomy was required in 5 cases to instrument the caudal vertebra. Tricortical iliac crest strut graft was used in 40 and cylindrical mesh cage in 2 cases. Correction of kyphosis was achieved by intra-op adjustment of the head assembly & controlled distraction. Post-operatively all wore cervical orthosis for 3 mo. Results: 41 patients were available for analysis (1 lost for f/u). The average number of corpectomies required were 2.5 (1–4) and the mean anterior column defect reconstructed was 27.3mm (22–42mm). The average graft subsidence was 3mm (0–10mm). 2 patients required revision surgery within 6 weeks for implant failure/graft resorption. Fusion occurred in rest of 39 patients. No further graft subsidence was noticed at 4 years in 17 patients. Spontaneous fusion at 3 mo was seen in normal adjacent segment due to plate overlapping in 2 cases. The average correction achieved was 15.220 (−40–730). The mortality rate was 2.12% (1 case). Visceral complications occurred in 3 cases (esophageal perforation in 1 and recurrent laryngeal nerve palsy in 2). The mean post-operative mJOA score was 14 (9 – 17). There was 1 deep and 1 superficial infection. Conclusion: Ant decompression & reconstruction with instrumentation facilitates neurological recovery restoring alignment. Intra-op maneuvering allows the graft to be placed in an optimal position that allows fusion under compression

A predictive model for final kyphosis was tested by evaluating the radiographs of forty-three patients with traumatic burst fractures. Since clinical outcomes are related to final kyphosis in the ambulatory patient rather than on the initial supine injury radiograph, the ability to predict final kyphosis is beneficial in determining treatment. This study demonstrated that in the appropriately selected patient for conservative care, the limit of final-kyphosis(Kf) can be predicted from the intial-kyphosis(KI) , such that Kf= < KI+.5KI . Outliers from this equation were patients who had unrecognized posterior column fractures, superior and inferior end-plate fractures, and/or multiple level of injury. The purpose of this study was to define a prediction model that afforded clinicians the ability to define final kyphosis from initial supine films in order to guide the management of stable burst fractures. This study has demonstrated that as a rule of thumb, the final absolute kyphosis for stable burst fractures can be expected to be up to Ki (initial absolute kyphosis) + 1.5Ki. Outliers were found to be fractures with unrecognized posterior element injury, both superior and inferior endplate fractures and multiple level injuries. The final kyphosis is clinically more relevant than the initial kyphosis in terms of functional outcome after conservative management. A prediction model for final kyphosis based on initial injury films can help guide the clinician for optimal management. Retrospective radiographic analysis was performed on forty-three patients with a minimum follow up six months. All patients suffered traumatic burst fractures, which were deemed stable as to be satisfactorily managed in a brace. Serial radiographs were used to determine initial (Ki) and final (Kf), Kyphosis angles. Predicted Kf was determined using the equation Kf =Ki + 1.5 Ki. The initial absolute kyphosis was the measured kyphosis using the Cobb technique and including the loss of the expected normal lordosis of that spinal segment. Inclusion criteria included burst fractures at between levels T10 – L3 in the neurologically intact patient. The equation accurately predicted the final outcome , Kf, in 70 % of the cases. In 20% of the cases, the Kf was less than expected. (Acceptable clinical result). In 10% of the cases, Kf was greater than predicted or achieved a clinically unacceptable kyphotic angulation requiring secondary surgery. In this group of outliers, post-hoc analysis identified unrecognized posterior element injury, both superior and inferior endplate fractures and multiple level injuries. In traumatic burst fractures, the goal of management is to protect the spine during healing while maintaining an acceptable alignment, which will not lead to late pain and deformity. A final absolute kyphosis angle, Kf, from twenty to thirty degrees has been variably regarded as a threshold to obtain a good clinical outcome. Criteria for stability have been previously documented, however variables are based on initial presentation. Aside from careful classification of the fracture type, the current “rule of thumb” prediction model for Kf may further help the clinician with management decisions

Introduction: Surgical treatment is indicated in Scheuermann’s disease with severe kyphotic deformity, and/or unremitting pain. Proximal or distal junctional kyphosis and loss of correction have been reported in the literature, due to short fusion level, overcorrection, or posterior only surgery with failure to release anterior tethering. We reviewed surgically treated Scheuermann’s kyphosis cases, to evaluate the factors affecting the sagittal balance. Methods and results: 35 cases (22 male, 13 female) of Scheuermann’s kyphosis were treated surgically in this centre during 1993–1999. Mean age at operation was 21.5 years (14–53 years). The kyphosis was high thoracic (Gennari Type I) in two cases, mid thoracic (Type II) in 11 cases, low thoracic or thoraco-lumbar (Type III) in eight cases, and whole thoracic (Type IV) in 14 cases. Mean pre-operative kyphosis (Cobb angle) was 81° (range 70° to 110°). Ten cases (mean kyphosis 77°) had one stage posterior operation only with segmental instrumentation. Twenty-five cases had combined anterior and posterior (A-P) surgery. Fifteen cases (mean kyphosis 81°) had one stage thoracoscopic release and posterior instrumentation, and 10 cases (mean kyphosis 89°) had open anterior release, followed by second stage posterior instrumentation. Minimum follow-up was 14 months (mean 45 months, range 14–140 months). The mean post-operative kyphosis was 47.2°. Kyphosis correction achieved ranged from 39% after posterior surgery only, to 42% after thoracoscopic A-P surgery, and 48% after open A-P surgery. Mean loss of correction was 12° after posterior only surgery, 9.5° after thoracoscopic A-P surgery, and 6° after open A-P surgery. Four cases of open A-P surgery had additional anterior cages to stabilise the kyphosis before posterior instrumentation; a mean 55% kyphosis correction was achieved in this group, and there was no loss of correction. Younger cases, under 25 years (n=16) had significantly better kyphosis correction (p< 0.05). Two cases (6%) developed distal junctional kyphosis due to fusion short of the first lordotic segment, requiring extension of fusion. Four cases (12%) developed proximal junctional kyphosis requiring extension of fusion; all of them had primary posterior surgery only. Location of the curve (Gennari Type) had no significant influence on the initial curve, degree of immediate correction, or loss of correction. Complications included infection (4 cases), pneumothorax (1 case), haemothorax (1 case), instrumentation failure (3 cases); 3 cases had persistent back pain. Conclusion: Combined anterior release and posterior surgery achieves and maintains better correction of Scheuermann’s kyphosis. Loss of correction, and proximal junctional kyphosis are more frequent after posterior surgery only, and short fusion. Use of cages anteriorly prevents loss of correction. Correction is better achieved in younger patients, but is not influenced by the location of the curve

Neural axis anomalies in idiopathic scoliosis (AIS) are well documented, with prevalence of 7% in adolescents; 20% in early-onset and up to 40% in congenital, the case for pre-operative MRI of brainstem to sacrum is well made in these groups. SK is rarer than AIS and the prevalence of anomalies is not defined. The case for routine MRI scan is unclear. A recent report concluded that routine MRI was not indicated, although this was based on only 23 MRI scans in 85 patients. At our institution all patients are undergo whole spine MRI following a diagnosis of SK. We aimed to assess the incidence of significant neural anomalies in Scheuermann's Kyphosis. Using a keyword search for “Scheuermann”, we reviewed all SK patients' MRI reports over the past 6 years. 117 MRI scans were identified. 13 patients did not fulfil the radiological criteria for SK and thus 104 (73M: 31F) scans were reviewed. 14 (13%) of 104 scans showed unexpected Significant abnormal findings. There were 8 (8%) with neural axis anomalies: 4 syrinxes; 1 cord anomaly; 2 cerebellar descents and 1 cerebellar tumour. All these patients had normal neurological examination except one with examination consistent with a known diagnosis of Parkinson's. A further 6 patients had non-neural anomalies. The presence of neural axis anomalies may influence the management of a patient with SK. Neurological compromise during correction is higher in patients with neural axis anomalies and this risk can often be partially mitigated by a preceding neurosurgical procedure (such as foramen magnum decompression or shunt). Furthermore it is well described that these anomalies often occur in patients who demonstrate a normal neurological examination. This study confirms this. Given that MRI is widely available and considering the devastating life implications of neurological injury, we advise pre-operative MRI scan in all SK patents

Purpose: To investigate the potential value of titanium anterior interbody cages compared to morselized rib graft for anterior interbody fusion in combination with posterior instrumentation, correction and fusion for Scheuermann’s kyphosis. Methods and Materials: A Non-Randomised historic cohort study of two surgical techniques in matched subjects was carried out.15 patients with identical pre-operative radiographic and physical variables (age, gender, height, weight, BMI ) were managed with combined anterior release, interbody fusion, posterior instrumentation, correction and fusion . Group A (n=8) had morsilized 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. Pre- and post-operative curve morphometry was studied on plain radiographs by two independent observers. The indices studied included Cobb angle, Ferguson’s angle(FA) , Voutsinas index(VI), 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 following surgery with standing radiographs. Wilcoxon-matched pairs test and Mann-Whit-ney test were used for statistical analysis. Results: The average follow-up for groups A was 70 and Group B,66 months. For the whole group, the pre-operative : postoperative median Cobb angle, FA, VI, SVA and SI were 86: 42degrees, 50 : 28.4degrees, 28.7 :13, −3.5 : −4.0 centimetres and 40 : 34 degrees respectively. There were significant differences for all variables [p< 0.01] indicating good correction. At four-year follow-up, fusion criteria were satisfied in 12 / 15 cases (80%). Three patients had distal junctional kyphosis. There was no significant difference with respect to the variables between the two groups and both retained the post-operative correction achieved. Conclusion: There was no significant advantage in the use of anterior titanium interbody cages over the use of morselized rib graft in the surgical management of Scheuermann’s Kyphosis

Clinically significant proximal junctional kyphosis (PJK) occurs in 20% of children treated with posterior distraction-based growth friendly surgery. In an effort to identify modifiable risk factors, it has been theorized biomechanically that low radius of curvature (ROC) implants (i.e., more curved rods) may increase post-operative thoracic kyphosis, and thus may pose a higher risk of developing PJK. We sought to test the hypothesis that EOS patients treated with low ROC (more curved rods) distraction-based treatment will have a greater risk of developing PJK as compared to those treated with high ROC (straighter) implants.

This is a retrospective review of prospectively collected data obtained from a multi-centre EOS database on children treated with rib-based distraction with minimum 2-year follow-up. Variables of interest included: implant ROC at index (220 mm or 500 mm), patient age, pre-operative scoliosis, pre-operative kyphosis, and scoliosis etiology. In the literature, PJK has been defined as clinically significant if revision surgery with superior extension of the upper instrumented vertebrae was performed.

In 148 scoliosis patients, there was a higher risk of clinically significant PJK with low ROC (more curved) rods (OR: 2.6 (95%CI 1.09-5.99), χ2 (1, n=148) = 4.8, p = 0.03). Patients had a mean pre-operative age of 5.3 years (4.6y 220 mm vs 6.2y 500 mm, p = 0.002). A logistic regression model was created with age as a confounding variable, but it was determined to be not significant (p = 0.6). Scoliosis etiologies included 52 neuromuscular, 52 congenital, 27 idiopathic, 17 syndromic with no significant differences in PJK risk between etiologies (p = 0.07). Overall, patients had pre-op scoliosis of 69° (67° 220mm vs 72° 500mm, p = 0.2), and kyphosis of 48° (45° 220mm vs 51° 500mm, p = 0.1). The change in thoracic kyphosis pre-operatively to final follow up (mean 4.0 ± 0.2 years) was higher in patients treated with 220 mm implants compared to 500 mm implants (220 mm: 7.5 ± 2.6° vs 500 mm: −4.0 ± 3.0°, p = 0.004).

Use of low ROC (more curved) posterior distraction implants is associated with a significantly greater increase in thoracic kyphosis which likely led to a higher risk of developing clinically-significant PJK in EOS patients.

Aims

To report the outcome of spinal deformity correction through anterior spinal fusion in wheelchair-bound patients with myelomeningocele.

Aims

To describe the clinical, radiological, and functional outcomes in patients with isolated congenital thoracolumbar kyphosis who were treated with three-column osteotomy by posterior-only approach.

1. A case of post-tetanic kyphosis is reported.

2. The clinical and radiographic features are described.

3. The theories of the mechanism of production of the deformity are discussed.

1. Three cases of congenital kyphosis at or near the thoraco-lumbar junction are reported.

2. The features of the deformity are discussed.

Purpose

To evaluate whether continuous training and education of posture can help children to improve kyphosis.

Aims

Whether a combined anteroposterior fusion or a posterior-only fusion is more effective in the management of patients with Scheuermann’s kyphosis remains controversial. The aim of this study was to compare the radiological and clinical outcomes of these surgical approaches, and to evaluate the postoperative complications with the hypothesis that proximal junctional kyphosis would be more common in one-stage posterior-only fusion.

Proximal junctional kyphosis (PJK) is defined as adjacent segment kyphosis >10° between the upper instrumented vertebrae and the vertebrae 2 levels above following scoliosis surgery. There are few studies investigating the predictors and clinical sequelae involved with this relatively common complication. Our purpose was to determine the radiographic predictors of post-op PJK and to examine the association between PJK and pain/HRQOL following surgery for AIS.

The Post-Operative Recovery after Scoliosis Correction: Home Experience (PORSCHE) study was a prospective multicenter cohort of AIS patients undergoing spinal fusion surgery. Pre-op and minimum 2 year f/u scoliosis and sagittal spinopelvic parameters (thoracic kyphosis–TK, lordosis–LL, pelvic tilt-PT, sacral slope-SS, pelvic incidence-PI) were measured and compared to numeric rating scale for pain (NRS) score, SRS-30 HRQOL and to the presence or absence of PJK (proximal junctional angle >100). Continuous and categorical variables were assessed using logistic regression and binomial variables were compared to binomial outcomes using chi-square.

163 (137 females) patients from 8 Canadian centers met inclusion criteria. At final f/u, PJK was present in 27 patients (17%). Pre-op means for PJK vs No PJK: Age 14.1 vs 14.7yr; females 85 vs 86%; scoliosis 57±22 vs 62±15deg; TK 28±18 vs 19±16deg ∗, LL 62±11 vs 60±12deg, PT 8±12 vs 10±10deg, SS 39±8 vs 41±9deg, PI 47±14 vs 52±13deg, SVA −9±30 vs −7±31mm. Final f/u for PJK vs No PJK: Scoliosis 20±11 vs 18±8deg, final TK 26±12 vs 19±10deg∗, LL 60±11 vs 57±12deg, PT 9±12 vs 12±13deg, SS 39±9 vs 41±9deg, PI 48±17 vs 52±14deg, SVA −23±26 vs −9±32mm∗. Significant findings: Pre-op kyphosis >40deg has an odds ratio (OR) of 4.41 (1.50–12.92) for developing PJK∗. The presence of PJK was not associated with any significant differences in NRS or SRS-30. ∗denotes p<0.05.

This prospective multicenter cohort of AIS patients demonstrated a 17% risk of developing PJK. Pre-op thoracic kyphosis >40deg was associated with the development of PJK; however, the presence of PJK was not associated with increased pain or decreased HRQOL.