Quality of Life Improvement Following Surgery in Adolescent Spinal Deformity Patients: A Comparison Between Scheuermann Kyphosis and Adolescent Idiopathic Scoliosis*

Spine Deformity 6 (2018) 676e683 www.spine-deformity.org

Quality of Life Improvement Following Surgery in Adolescent Spinal Deformity Patients: A Comparison Between Scheuermann Kyphosis and Adolescent Idiopathic Scoliosis* Courtney Toombs, BAa, Baron Lonner, MDb,*, Suken Shah, MDc, Amer Samdani, MDd, Patrick Cahill, MDe, Harry Shufflebarger, MDf, Burt Yaszay, MDg, Paul Sponseller, MDh, Peter Newton, MDg a New York University School of Medicine, 550 1st Avenue, New York, NY 10016, USA Department of Orthopaedic Surgery, Mount SinaieBeth Israel Medical Center, 1st Avenue &, E 16th St, New York, NY 10003, USA c Department of Orthopaedic Surgery, Nemours Children’s Clinic, Wilmington, DE, USA d Department of Orthopaedic Surgery, Shriners Hospitals for Children, 3551 N Broad St, Philadelphia, PA 19140, USA e Department of Orthopaedic Surgery, Children’s Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA f Department of Orthopaedic Surgery, Miami Children’s Hospital, 3100 SW 62nd Ave, Miami, FL 33155, USA g Department of Orthopaedic Surgery, Rady Children’s Hospital San Diego, 3020 Children’s Way, MC 5069, San Diego, CA 92123-4282, USA h Department of Orthopaedic Surgery, Johns Hopkins Hospital, 1800 Orleans St, Baltimore, MD 21287, USA Received 30 January 2018; accepted 25 April 2018 b

Abstract Study Design: Preoperative and two-year follow-up health-related quality of life (HRQOL) data were prospectively collected in 82 Scheuermann kyphosis (SK) and 995 adolescent idiopathic scoliosis (AIS) patients using the Scoliosis Research Societye22 patient questionnaire (SRS-22) outcomes instrument in a multicenter study. Visual analog scale (VAS) scores were also collected for the SK population. Objectives: This study assessed changes in HRQOL prospectively and compared them to those occurring in AIS. Summary of Background Data: There has been limited evaluation of patient-reported HRQOL changes with operative management of SK. Methods: Median SRS values for the SK and AIS cohorts were compared using a repeated measure of analysis of variance with age as a covariate and using a Mann-Whitney U nonparametric comparison. Results: Kyphosis was corrected from 73.9 to 45.8 (p ! .001); the major curve in AIS was corrected from 55.5 to 20.2 (p ! .001). Preoperative and magnitude of radiographic correction, kyphosis apex and body mass index in SK were not correlated with baseline or change in HRQOL. SK SRS scores improved after surgery in all domains with the greatest change (2.8e4.4) in self-image (p ! .001). Changes in SRS Pain, Activity, and Self-Image domains met the minimal clinically important difference. Baseline SK and AIS scores differed significantly in the Self-Image, Mental Health and Total Score domains, with SK having worse scores (p ! .001). At two years postoperatively, the greatest improvements were made in Self-Image, along with Mental Health and Total Score, and the SK group achieved greater gains (p ! .001). At two years postoperatively, the SK scores improved to reach equivalent values to the AIS scores. VAS scores improved from 3.69 to 1.51, and these changes were correlated with change in the Pain, Mental Health, and Total Score SRS domains (p ! .001). Conclusions: Surgery for SK in the adolescent population results in significant improvements in HRQOL, which outpace those of the AIS population. Level of Evidence: Level II. Ó 2018 Scoliosis Research Society. All rights reserved. Keywords: Scheuermann’s kyphosis; Adolescent idipathic scoliosis; Health-related quality of life; Scoliosis Research Society Questionnaire; Self-Image; Pain

2212-134X/$ - see front matter Ó 2018 Scoliosis Research Society. All rights reserved. https://doi.org/10.1016/j.jspd.2018.04.009

C. Toombs et al. / Spine Deformity 6 (2018) 676e683 Author disclosures: CT (none), BL (grants from Setting Scoliosis Straight Foundation, during the conduct of the study; grants from Setting Scoliosis Straight Foundation, personal fees from DePuy Synthes Spine, K2M, Paradigm Spine, Spine Search, and from Ethicon; nonfinancial support from Spine Deformity Journal; grants from AO Spine, John and Marcella Fox Fund Grant, grants from OREF, outside the submitted work), SS (grants from Harms Study Group via the Setting Scoliosis Straight Foundation, during the conduct of the study; personal fees from DePuy Synthes Spine, K2M, and NuVasive, outside the submitted work), AS (grants from DePuy Synthes Spine, during the conduct of the study; personal fees from DePuy Synthes Spine, Ethicon, Globus Medical, Misonix, Stryker, and Zimmer Biomet, outside the submitted work), PC (none), HS (grants, personal fees, and other from DePuy Synthes Spine; personal fees and other from K2M, during the conduct of the study; grants, personal fees, and other from DePuy Synthes Spine, personal fees and other from K2M, outside the submitted work), BY (grants from DePuy Synthes Spine, during the conduct of the study; grants and personal fees from DePuy Synthes, personal fees from NuVasive, grants and personal fees from K2M, personal fees from Globus, personal fees from Orthopediatrics, personal fees from Medtronic, personal fees from Stryker, outside the submitted work; in addition, BY has a patent K2M with royalties paid), PS (personal fees from DePuy Synthes Spine, from Globus, personal fees from Journal of Bone and Joint Srugery, outside the submitted work), PN (grants from Setting Scoliosis Straight Foundation, during the conduct of the study; grants

Introduction Spinal deformities in adolescent patients have an established effect on health-related quality of life (HRQOL), self-image, and psychosocial functioning [1-3]. Patients with operative Scheuermann kyphosis have been shown to have lower preoperative HRQOL scores than operative adolescent idiopathic scoliosis (AIS) patients and normal controls [3]. Higher pain scores in the SK population, compared with AIS patients and normal controls, have also been reported, with correlations between increased pain scores and lower overall HRQOL scores [3]. SK patients undergoing bracing treatment have reported anxiety related to their appearance, trouble interacting socially because of their back appearance, and increased pain compared to controls [2]. Treatment of SK primarily focuses on pain, deformity progression, and prevention of sequelae of severe kyphosis, but treatment effects on patient-reported HRQOL has not been widely studied [4]. Operative treatment for SK has been shown to improve kyphosis magnitude, pain, and pulmonary function [5-9]. We set out to prospectively study changes in HRQOL after operative treatment of SK, their relationship to kyphosis magnitude, and compare them to those occurring after surgical treatment for AIS. Materials and Methods Study measures Prospective, multicenter studies of consecutive patients with SK involving 10 institutions (97 total patients) and retrospective, multicenter studies of consecutive patients with AIS involving 15 institutions (1,106 total patients)

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and other from Setting Scoliosis Straight Foundation; other from Rady Children’s Specialists, grants and personal fees from DePuy Synthes Spine; personal fees from Law firm of Carroll, Kelly, Trotter, Franzen & McKenna; personal fees from Law firm of Smith, Haughey, Rice & Roegge, grants from NIH, grants from OREF, grants and other from SRS, grants from EOS imaging, personal fees from Thieme Publishing, other from NuVasive, personal fees from Ethicon Endosurgery, other from Electrocore, personal fees from Cubist, other from International Orthopedic Think Tank, other from Orthopediatrics Institutional Support, personal fees from K2M, outside the submitted work; in addition, PN has a patent ‘‘Anchoring systems and methods for correcting spinal deformities’’ (8540754) with royalties paid to DePuy Synthes Spine, a patent Low profile spinal tethering systems (8123749) issued to DePuy Spine, Inc., a patent Screw placement guide (7981117) issued to DePuy Spine, Inc., and a patent Compressor for use in minimally invasive surgery (7189244) issued to DePuy Spine, Inc). Funding: Grant from DePuy Spine to Setting Scoliosis Straight Foundation in support of the Harms Study Group’s research. IRB Approval: Institutional Review Board approval was obtained for this study from the NYU Langone Medical Center IRB. *Corresponding author. Scoliosis and Spine Associates, 820 Second Avenue, Suite 7A, New York, NY 10017, USA. Tel.: 212-986-0140; fax: 212-986-0160. E-mail address: [email protected] (B. Lonner).

were conducted from 2006 to 2011. The SK group was consented to be studied prospectively as a comparison to the AIS group. The AIS group was not consented to be studied compared to the SK group and therefore was retrospective data. Each database was queried for those patients with preoperative Scoliosis Research Societye22 patient questionnaire (SRS-22) scores and minimum twoyear follow-up SRS-22 scores and basic demographic, clinical, and radiographic data. The final patient cohort for this study consisted of 82 SK patients and 995 AIS patients. Excluded patients lacked one or more of the required information points to allow for equivalent comparison between groups without missing data points. The SRS-22 is a five-section survey that was originally created for the measurement of HRQOL in scoliosis patients [10,11]. The domains include Pain, Function (Activity), Mental Health, Self-Image (Appearance), and Satisfaction with management. Scores for each question range from 1 to 5, with 1 being the worst and 5 being the best. In the case of the Pain domain, a score of 5 indicates no pain and a score of 1 indicates a great deal of pain. Postoperative questions contained in the measure are completed only after a patient has undergone surgery. SRS-22 domain score improvements were also compared to published values for the minimal clinically important difference (MCID) for the domains of the SRS in AIS. The MCID represents ‘‘a threshold of improvement that is clinically relevant to the individual patient’’ or ‘‘the smallest difference in the score of the outcome instrument that patients perceive as important’’ [12,13]. For AIS patients, MCID values that have been published for the Pain, Function and Self-Image domains are 0.20, 0.08, and 0.98, respectively [12]. MCID values have not yet

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been determined for the Mental Health and Total Score domains of the SRS-22, and no MCID values have yet been determined for the SK population. The change in SRS domain scores for each patient in both groups was calculated. Each patient was classified into one of three categories for their change in Pain, Function, and Self-Image scores: worsened score, improved score, no change in score. Worsened score signified a difference between postand preoperative domain score that was a negative value greater than or equal to the MCID for that domain. Improved score signified a difference in postoperative to preoperative score that was a positive value greater than or equal to the MCID for that domain. Finally, the no change in score indicated a post- to preoperative change that did not meet the MCID in either direction. The difference in number of individuals in the AIS and SK groups who met the positive or negative MCID or who did not meet the MCID for each domain was compared using a chisquare test. Visual analog scale (VAS) pain scores were collected for the SK patients to supplement the SRS-22 on the measure of patient-reported pain. The database study group uses a segmented numeric version of the VAS score. The VAS instrument measures pain on a continuous spectrum of values (1 5 least pain, 10 5 most pain) that is easily understood by patients. Statistical analysis Preoperative and postoperative clinical data collected included age, gender and body mass index (BMI), radiographic measures, SRS-22 scores, and VAS scores (for SK). Radiographic data evaluated for all patients included T2e12, T5eT12, and greatest magnitude kyphosis, kyphosis apex location, major coronal curve magnitude, and thoracic and lumbar curve apex location. All domains of the SRS-22 were recorded and scores were calculated. Values were reported as the mean and median scores. Scores were compared at baseline and at two years postoperation between the two groups, as well as compared based on the change from preoperative visit to two years postoperative visit within each diagnosis group and between the two diagnosis groups. The SK and AIS cohorts were compared based on radiographic data, SRS and VAS scores. Mean and median scores at each time-point were compared using a multivariate analysis of variance with age as a covariate. Change in mean SRS scores were compared between the two groups using a repeated measures analysis of variance with age as a covariate and using a Mann-Whitney U test. SK patients were also subdivided by kyphosis apex location (midthoracic [T, defined as having an apex proximal to T10] or low thoracic or thoracolumbar [TL, defined as an apex at T10 or more caudal]). SRS scores were

compared for the SK group based on kyphosis apex at preoperation and at two years postoperation using a repeated measures analysis of variance with age as a covariate. The change in domain scores based on kyphosis apex was analyzed with a nonparametric Mann-Whitney U test. Change in SRS-22 scores after surgery was also compared to preoperative and change in kyphosis magnitude in the SK group, preoperative major Cobb angle in the AIS group, and preoperative BMI in the SK group by calculating a Pearson correlation coefficient to determine the relationship between each set of variables. A negative value for the correlation coefficient indicates a decrease in kyphosis. VAS scores in SK were compared before and after surgery using a Wilcoxon signed rank test. A relationship between change in VAS score and change in SRS-22 score was evaluated by calculating a Pearson correlation coefficient. A negative value for the correlation coefficient indicates a decrease in VAS score. Results Eighty-two operative SK patients (mean age 16.3  1.7, 30 female) were compared to 995 AIS patients (mean age 14.8  2.1, 793 female). Scheuermann kyphosis was corrected from 73.9 to 45.8 (p ! .001); the major curve in AIS was corrected from 55.5 to 20.2 (p ! .001) (Table 1). Baseline SK and AIS scores differed significantly in the Self-Image, Mental Health, and Total Score domains between the two groups; SK had worse scores than AIS in all three domains (p ! .001, p 5 .004, p ! .001, respectively) (Table 2). Preoperative AIS curve magnitude was significantly associated with lower Self-Image (r 5 0.02, p ! .0001), General Function (r 5 0.015, p ! .0001), and Total scores (r 5 0.014, p ! .0002). Increasing postoperative AIS curve magnitude was only associated with lower Self-Image scores (r 5 0.017, p ! .0001). Change in Table 1 Radiographic measures of kyphosis and scoliosisdchange (n 5 82).

SK kyphosis T2eT12 Preoperative Two-year SK kyphosis T5eT12 Preoperative Two-year SK greatest sagittal Cobb angle Preoperative Two-year AIS greatest coronal Cobb angle Preoperative Two-year

Mean

Range

Standard deviation

p

68.2 44.8

47e93 31e69

11.3 9.6

!.001

63.5 30.7

41e93 27e54

12 8.1

!.001

73.9 45.8

42e104 22e69

11.8 9.9

!.001

55.5 20.2

19e128 0e70

12.6 8.3

!.001

AIS, adolescent idiopathic scoliosis; SK, Scheuermann kyphosis.

C. Toombs et al. / Spine Deformity 6 (2018) 676e683 Table 2 SK change in SRS scores from preoperation to two years postoperation (N 5 82). SRS score Pain Preoperative Two-year Self-Image Preoperative Two-year General Function Preoperative Two-year Mental Health Preoperative Two-year Total Preoperative Two-year Satisfaction* Preoperative Two-year

Mean Standard Median p deviation

p (age as Wilcoxon covariate) signed rank

3.8 4.3

0.83 0.78

4 4.4

!.001 .89

!.001

2.8 4.4

0.78 0.71

2.8 4.4

!.001 .015

!.001

4.2 4.4

0.68 0.67

4.3 4.5

.033 .614

.011

3.6 4.1

0.85 0.73

3.6 4.2

!.001 .528

!.001

3.6 4.3

0.59 0.57

3.7 4.5

!.001 .089

!.001

3.7 4.64

1.0 0.61

!.001 .206

AIS, adolescent idiopathic scoliosis; SK, Scheuermann kyphosis; SRS, Scoliosis Research Society questionnaire. The minimal clinically important difference was validated in AIS patients only. The mean change for each domain was as follows: Pain 5 0.20; Self-Image 5 0.98; General Function 5 0.06. * N 5 67.

AIS curve magnitude was only associated with change in the General Function domain (r 5 0.008, p 5 .00) of the SRS. Lenke curve type was not significantly related to mean SRS domain or total score, except for a difference between postoperative Function Scores for Lenke 1 (4.61) and 2 (4.72) groups (p ! .05). SK SRS scores demonstrated a statistically significant improvement (p ! .005) after surgery in all domains, except Satisfaction, with the greatest change (median 2.8 to 4.4) in self-image (Table 3). The Pain domain improved from 3.8 to 4.3 (p 5 .005), General Function from 4.2 to 4.4 (p 5 .003), Mental Health from 3.6 to 4.1 (p 5 .001), and Total Score from 3.6 to 4.3 (p 5 .001) (Table 3). Changes in mean SRS pain, activity, and self-image domains met the minimal clinically important difference for these domains (as determined for AIS patients): Pain 5 0.20, Self-Image 5 0.98, and General Function 5 0.08 [12]. Overall, the percentage of patients in each group who met the MCID for the Pain, Self-Image, and General Function domains were similar between the two groups (Table 4). For the Pain domain, 61% to 67% of patients in each group met the improved MCID, 56% to 78% for Self-Image, and 51% to 54% for General Function. Significantly more patients met the MCID and improved their score for Self-Image in the SK group than the AIS group (78% vs. 56%). There was no significant difference in the number of patients who met the MCID with either

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an improved score or a worsened score for the Pain and General Function domains between the two groups (Table 4). At two years postoperation, the greatest improvements were made in Self-Image, especially in the SK group (1.53 points) versus 1.06 points in the AIS group (p ! .001). Mental Health and Total scores also improved significantly, and the SK group achieved greater gains (0.49 and 0.72 points respectively) (p ! .001). Pain and Function score improvements in both groups met the MCID; however, the difference was not statistically significant between groups. Both groups met the MCID for Self-Image. The SK group improved more in their SRS domain and Total scores than the AIS group and thus at two years postoperation, the SK group scores improved to reach values that were not statistically different from the AIS scores in any domains (Figure). Preoperative Scheuermann kyphosis magnitude was not correlated with any HRQOL domains: p 5 .12 (r2 5 0.03) for Pain; p 5 .08 (r2 5 0.04) for Self-Image; p 5 .90 (r2 5 0.00) for General Function; p 5 .10 (r2 5 0.03) for Mental Health; p 5 .94 (r2 5 0.00) for Satisfaction; and p 5 .10 (r2 5 0.03) for Total score. SK radiographic correction was not significantly correlated with nearly all domains of the SRS, indicating no relationship between HRQOL and deformity magnitude. Change in the Function domain was weakly correlated with change in radiographic kyphosis (r 5 0.243, p 5 .03). No changes were observed in SRS domain scores based on kyphosis apex at either preor postoperation (Change in Scores for Pain: T 5 3.9 to 4.3, L 5 3.5 to 4.1; Self-Image: T 5 2.8 to 4.4, L 5 2.8 to 4.2; Function: T 5 4.3 to 4.5, L 5 4 to 4.3; Mental Health: T 5 3.7 to 4.1, L 5 3.5 to 4; Satisfaction: T 5 3.6 to 4.7, L 5 3.8 to 4.5; Total Score: T 5 3.6 to 4.4, L 5 3.5 to 4.2; p O .05). There was no significant difference between kyphosis groups in terms of change in domain scores (Change in Pain: T 5 0.4, L 5 0.5; Self-Image: T 5 1.6, L 5 1.4; Function: T 5 0.2, L 5 0.2; Mental Health: T 5 0.5, L 5 0.5; Satisfaction: T 5 1, L 5 0.8; Total Score: T 5 0.7, L 5 0.7; p O .05). The changes in SRS scores were not affected by the baseline kyphosis magnitude of the patients (p 5 .85 for Pain; p 5 .65 for Self-Image; p 5 .36 for General Function; p 5 .80 for Mental Health, p 5 .98 for Satisfaction; and p 5 .63 for Total Score). Preoperative greatest scoliosis Cobb angle and BMI were not correlated with SRS score change (BMI vs. SRS Domains Pain, Self-Image, Function, Mental Health, Satisfaction, and Total Score: r 5 0.06, 0.09, 0.08, 0.2, 0.01, 0.09, respectively; p O .05) (Cobb vs. SRS Domains Pain, Self-Image, Function, Mental Health, Satisfaction, and Total Score: r 5 0.03, 0.03, 0.09, 0.01, 0.0, and 0.05, respectively; p O .05). Baseline (Apex 1: 3.4 and Apex 2: 4.7), postoperative (1.6 and 1.6), and change ( 2 and 2.8) in VAS scores did not correlate with kyphosis apex classification

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Table 3 SRS domain scores, by group: SK (n 5 82) versus AIS (n 5 995). SRS domain scores Pain Preoperative AIS PSK Two-year AIS PSK Change AIS PSK Self-Image Preoperative AIS PSK Two-year AIS PSK Change AIS PSK General Function Preoperative AIS PSK Two-year AIS PSK Change AIS PSK Mental Health Preoperative AIS PSK Two-year AIS PSK Change AIS PSK Satisfaction Preoperative AIS PSK Two-year AIS PSK Change AIS PSK Total Preoperative AIS PSK Two-year AIS PSK Change AIS PSK

Mean

Standard deviation

Median

4.1 3.8

0.70 0.83

4.2 4

4.4 4.3

0.62 0.80

4.6 4.4

0.31 0.44

0.73 0.85

3.7 2.8

0.68 0.78

3.4 2.8

4.4 4.4

0.56 0.71

4.6 4.4

1.06 1.53

0.77 0.96

4.4 4.2

0.57 0.67

4.5 4.3

4.6 4.4

0.48 0.67

4.8 4.5

0.19 0.20

0.62 0.85

4.0 3.6

0.69 0.85

4 3.6

4.2 4.1

0.67 0.73

4.4 4.2

0.23 0.49

0.75 0.81

3.7 3.7

1.0 1.0

3.5 4

4.6 4.6

0.66 0.61

5 5

0.92 0.98

1.09 1.02

3.9 3.6

0.48 0.59

4 3.7

4.4 4.3

0.46 0.57

4.5 4.5

0.50 0.72

0.50 0.63

p

Mann-Whitney U

.17

.005

.291

.12

!.001

n/a

!.001

.711

!.001

.74

n/a

.003

.002

.86

.004

n/a

.001

.10

.003

.68

n/a

.95

.77

.68

n/a

.001

!.001

.14

!.001

n/a

AIS, adolescent idiopathic scoliosis; SK, Scheuermann kyphosis; SRS, Scoliosis Research Society questionnaire. The minimal clinically important difference was validated in AIS patients only. The mean change for each domain was as follows: Pain5 0.20, SelfImage 5 0.98, General Function 5 0.06.

C. Toombs et al. / Spine Deformity 6 (2018) 676e683 Table 4 Comparison of participants meeting the minimal clinically important difference for pre- to postoperative change in domain scores for AIS and SK.

Pain AIS (n 5 995) SK (n 5 82) Self-Image AIS (n 5 995) SK (n 5 82) General Function AIS (n 5 995) SK (n 5 82)

Improved score, n (%)

Worsened score, n (%)

No change, n (%)

p value

610 (61) 55 (67)

236 (24) 17 (21)

149 (15) 10 (12)

.56

554 (56) 64 (78)

5 (1) 1 (1)

426 (43) 17 (21)

.00

512 (51) 44 (54)

240 (24) 25 (30)

243 (24) 13 (16)

.16

AIS, adolescent idiopathic scoliosis; SK, Scheuermann kyphosis.

(thoracic or thoracolumbar) (p O .05). VAS scores improved significantly from 3.69 (2.9) to 1.51 (2) in the SK group (p ! .001), and these changes were correlated with change in the Pain (r 5 0.61), Mental Health (r 5 0.27), and Total Score (r 5 0.33) SRS domains (p ! .005). As the SRS Pain scores increased, indicating reduced pain, the VAS score decreased, also indicating reduced pain (r 5 0.61, p 5 .00). As the VAS score decreased (pain decreased), Total and Mental Health scores increased, indicating gains in those domains (r 5 0.27, p 5 .05; r 5 0.33, p 5 .01). Self-Image (r 5 0.07), Function (r 5 0.03), and Satisfaction (r 5 0.02) were not correlated with change in VAS Score.

681

Discussion Improvements in HRQOL after surgery for adolescent spinal deformity have been broadly studied in the AIS population; however, little data exist regarding changes in HRQOL associated with surgical correction of SK. Previously reported preoperative comparisons of HRQOL in SK and AIS and found poorer scores in all domains of the SRS for SK compared to AIS [1,3]. In this study, SK and AIS patients improved significantly in their SRS-22 scores after corrective surgery, with the SK cohort achieving greater gains, especially in Self-Image. The SRS score improvements also met the MCID for all three domains for which this value is available, indicating that these changes are both statistically and clinically significant. No relationship was found between preoperative, postoperative, or change in kyphosis magnitude or kyphosis apex. Other studies have not found correlation between the degree of correction or radiographic curve measurements and HRQOL scores in the SK population; however, they did indicate that patients in the study were overwhelmingly satisfied with their decision to have surgery and improved significantly in their HRQOL scores [3,14]. In a large Danish twin registry study of 73,000 pairs, 943 were found to have Scheuermann kyphosis and were compared to the remaining healthy twin pairs [15]. The SF12, a questionnaire assessing physical and mental health, was administered to all participants and the study found

Fig. Differences in baseline and change in SRS scores after surgery for SK (gray) and AIS (black) groups. *Significant difference in baseline scores between SK and AIS (p ! .001 for ANOVA). ǂSignificant change in SRS score from preoperation to two years in both groups (SK and AIS) (p ! .001 for MannWhitney U test). Also, no significant difference was found in SRS scores between the two groups at the two-year time point. (AIS, adolescent idiopathic scoliosis; Pre, preoperative score; SK, Scheuermann kyphosis; 2yr, two-year postoperative score.)

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that physical health was significantly worse in SK patients than in healthy controls; however, mental health was similar for the two groups [15]. In one study of operative correction of Scheuermann kyphosis in 49 patients with mean preoperative kyphosis of 92 , SRS-22 scores improved from a mean preoperative score of 3.4 to 4.6 at two years, with high treatment satisfaction rates [16]. Another study of 23 postoperative SK patients, average age 22 years (range 18e28), found no change in ODI or SRS22 score at 35e70 months’ follow-up [17]. Total and domain-specific scores in our study improved significantly after surgery, with greater improvements in nearly all domains for the SK group compared to the AIS group. Self-Image scores for the SK group in our study were quite low at baseline (mean 2.8) and improved dramatically to 4.3 postoperatively. Prior studies have shown that preoperative SK patients report feeling more concerned about their appearance than age- and sex-matched controls, they have lower Self-Image domain scores than normal controls as well as AIS patients, and that the Self-Image domain of the SRS is most strongly correlated with kyphosis magnitude compared to other SRS domains [1-3]. These studies are consistent with the findings of our study, except that change in kyphosis was not correlated with change in SRS score, except for the General Function domain, in which greater correction was associated with improved scores. Radiographic correction of SK; preoperative kyphosis apex; and preoperative, postoperative, or change in kyphosis magnitude were not correlated with change in SRS scores, indicating that the size of the deformity and the magnitude of correction were not significant to the patient’s HRQOL changes. This is similar to what has been reported for SK and AIS in a number of studies in which the magnitude of curve correction is not differentiated by the SRS-22 instrument [3,14,18-20]. In a preoperative study of SRS scores in the SK population, the magnitude of kyphosis was not correlated with any SRS domain score [18]. However, that study found that patients with a TL apex had a significantly worse mean pain score than the T apex group [18]. In our study, no differences in baseline SRS score or change in SRS score were found based on kyphosis apex group. SK patients also achieved significant improvements in self-reported pain after surgery, as assessed by VAS scores and the Pain domain of the SRS. As pain scores improved, so did the patient’s SRS Pain, Mental Health, and Total scores. These results indicate that pain in SK patients is directly tied to mental health functioning and total HRQOL, and surgical correction improves these deficits by reducing deformityrelated pain. After Self-Image, Mental Health scores were the second worst scores preoperatively in SK patients, indicating a potential mental health component to the baseline SK experience. It was surprising that improved Pain scores did not correlate with increased SRS Function/Activity scores; however, the mean preoperative Function score in the SK group was quite good (4.3), leaving little room for further improvement and indicating little impact on function

in the adolescent population from this condition. Self-Image and Satisfaction with Treatment are domains related to the physical changes in the patient’s body shape explaining the marked improvement in those domains beyond other domains after deformity correction. In this study, SK and AIS patients differed significantly in baseline Self-Image, Mental Health, and Total SRS scores, as expected based on published reports including our own prior work of the increased psychological and physical effects of the SK deformity [3,4,21]. All SK patients in the study improved their total SRS score and domain scores after surgery, but only changes in SelfImage, Mental Health, and Total scores were statistically significant. Although the Pain and General Function did not statistically improve, 61% to 67% and 51% to 54% of patients in each domain, respectively, met the improved score MCID. However, the MCID has not yet been validated in the SK population, and this area of study requires further investigation as this study indicates the need for understanding clinically meaningful changes in quality of life in this population. Similar results were also found and expected in the AIS population, based on prior reports of improved HRQOL scores after AIS surgery [18]. The strengths of this study include the use of a large, prospectively collected cohort of operative SK patients analyzed with age as a covariate, a common confounding variable in this population. This operative population provides a smaller spectrum of curve magnitudes that might not be able to delineate differences in kyphosis magnitude over a wider range that would impact HRQOL. The improvements in SK HRQOL are substantial after surgery and match the postoperative scores of AIS patients, making the two groups indistinguishable by HRQOL scores. These results suggest that surgical correction of the SK deformity ameliorates much of the psychological and physical strain on the SK patient that preoperatively separated them from the less symptomatic AIS patients. Conclusions Surgery for Scheuermann kyphosis in the adolescent population results in significant improvements in health-related quality of life (HRQOL). SK patients with deformity in the operative range have worse HRQOL overall and in Self-Image and Mental Health domains, specifically, before surgery compared with AIS patients who have deformity of a magnitude warranting operative management. Improvement in HRQOL after surgical correction was greater in SK, resulting in HRQOL scores that match the scores of postoperative AIS patients. This information can be used to council patients and their families on the benefits of surgical correction in SK. References [1] Petcharaporn M, Pawelek J, Bastrom T, et al. The relationship between thoracic hyperkyphosis and the Scoliosis Research Society outcomes instrument. Spine (Phila Pa 1976) 2007;32:2226e31.

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