1. Introduction
The Scoliosis Research Society has defined the normal value of thoracic kyphosis to range from 20˚-40˚ in growing adolescents [1, 2]. The thoracic kyphotic curve ˃45˚ leads to hyperkyphosis deformity [3]. Furthermore, it is the most prevalent disorder in patients with a deformed spine after idiopathic scoliosis [4, 5]. Several conditions result from hyperkyphosis; Scheuermann`s disease is a common reason with an incidence of 4%-8% in this respect [6, 7]. In general, if no scientific reason can explain an existing hyperkyphosis, the term “idiopathic hyperkyphosis” is used [3].
Treating hyperkyphosis is crucial in growing children. Untreated kyphosis may lead to increased deformity, back pain, restricted motion, pulmonary disease, and neurological disorders [8-10]. The most common treatment approaches are surgical and non-surgical methods [10-13]. Surgical treatment is prescribed to patients with a curve of ˃75˚; however, it may cause postoperative neurological deficits, infections, vertebra fixator failure, pseudarthrosis, the loss of correction, kyphosis progression, a pulmonary disorder, and the risk of death [14]. Non-surgical treatment is often prescribed for patients with 45˚-75˚ thoracic kyphosis [15]. It comprises casting, physical therapy, and orthoses; orthotics treatment is the most effective non-surgical treatment for 55˚-75˚ hyperkyphosis deformity [16, 17]. Tribus and Lowe conducted independent studies implemented by an orthotic correction in hyperkyphosis. They concluded that bracing could achieve approximately 50% correction [1, 18]. Different orthoses were prescribed for hyperkyphosis treatment, such as Milwaukee brace [10, 12, 16, 19], Boston brace [13, 20], DuPont brace [21], and Kyphologic brace [22]. Milwaukee brace is widely used to treat hyperkyphosis in adolescents [10, 12, 16, 19]. It typically includes pelvic girdle (pelvic mold), bars (superstructures), and the combination of corrective sling and pads attached to the superstructures [16, 19]. Another brace is called Lyon, which was evaluated in this study for hyperkyphosis treatment. It contains two central bars and collateral shells. Central bars are located in the anterior and posterior parts of a brace from sternal notch to symphysis pubic. The collateral shells apply corrective forces and their function is identical to kyphotic pads in Milwaukee brace [23-25].
The effectiveness of orthotics treatment depends on the evaluation of in-brace correction; it is the best guideline for predicting treatment outcomes [26-28]. Spinal orthoses can provide 50% correction in the brace, and approximately two-thirds of cases may maintain partial correction in the long term [1, 18]. Other factors which significantly impact brace treatment outcomes are compliance and patient's Quality of Life (QoL) [26, 27]. The Society on Scoliosis Orthopedic and Rehabilitation Treatment (SOSORT) revealed that brace compliance should not be ignored because corrective bracing yields a favorable outcome when the patient is compliant [28, 29]. Weinstein also detected a significant association between the average hours of daily brace wear and the odds of a successful treatment outcome [30]. In-brace correction, compliant brace, and patient’s QoL are the main factors in curve correction outcomes. Typically, wearing spinal brace impairs QoL in patients with spinal deformity [31]. Moreover, various braces have different effects on the impairment extent [32]. They might create mental health disorders, such as increased stress, psychological disorders, disturbed body image, and a poor self- esteem [33].
Therefore, comparing the effective factors in the two brace groups can provide data on the appropriate brace selection. The current study assessed in-brace correction, compliance, and QoL between patients using Milwaukee brace and Lyon brace
2. Materials and Methods
The study population has been extracted from the entire database of a single orthotist and physician based on their records in a spinal clinic in Iran. Inclusion criteria were as follows: the diagnosis of thoracic hyperkyphosis, Cobb angle between 55˚ and 75˚, the age range of 10-17 years, Risser sign 0-2 at the beginning of treatment, full-time brace prescription, no previous treatment received, and the use of Milwaukee and Lyon braces. Exclusion criteria were diagnosed congenital spinal disease, identified scoliosis of ˃10˚, and any disorder in the shoulder, hip, and lower limbs. In total, 23 patients participated in the study [Milwaukee brace group (n=15), and Lyon brace group (n=8)].
This was a retrospective comparative study regarding the effectiveness of orthosis (in-brace correction), compliance, and the QoL between two brace treatment groups of hyperkyphosis patients. The applied braces were made by the standard procedures of casting, fabrication, and fitting. Kyphotic pads in Milwaukee brace and shells in Lyon brace were the main structures to apply corrective forces. The obtained data were collected using the Quality of Life Profile for Spinal Deformities (QLPSD) scale and the Persian Adaption of Personal Self-Care Assessment Questionnaire [34].
The in-brace correction refers to changing the curve angle, resulted from orthotic treatment, and focused on the effectiveness of treatment. It was assessed by the angle differences in two consecutive X-rays conducted before and two months after brace treatment [22].
All patients were prescribed with full-time bracing (max: 22 hours daily, min: 18 hours daily). In the present study, compliance was subjectively measured via in-person interviews. The study subjects were requested to report the hours spent wearing the brace per day. The compliance rates were determined by the following formula: (wearing time ×100) / prescribed time.
QoL refers to the psychosocial aspects of orthotic treatment. QoL measurement instruments, including the QLPSD questionnaire [34], were applied. It contains 21 items and 5 groups of variables describing 5 factors in terms of labeled psychosocial functioning, sleep disturbance, back pain, body image, and back flexibility. Administrating QLPSD averagely lasts 10 minutes. Each item is allocated a score of 5 (strongly agree), 4 (agree), 3 (undecided), 2 (disagree), to 1 (strongly disagree). Higher scores indicate highly impaired QoL. Additionally, the maximum obtained score was 105. Scoring time also took about 2 minutes [35].
The relevant data were summarized by descriptive statistics, including mean and standard deviation. An in-brace correction was defined as the difference between the mean scores of Cobb angles in the two X-ray phases. Data normality was assessed by the Kolmogorov-Smirnov (K-S) test. In addition, all collected data were evaluated using the Paired Samples t-test. The Independent Samples t-test was used to compare in-brace correction as well as compliance between the two groups. To determine the patients` QoL, the mean scores of QLPSD were measured, and an Independent Samples t-test was used.
3. Results
The present study investigated 23 patients; among whom, 15 (6 females and 9 males) wore Milwaukee brace, and 8 subjects (2 females and 6 males) were prescribed Lyon brace. The mean age and initial Cobb angle of the Milwaukee group were 14±0.65 years, and 67.9˚±6.3˚, respectively. These variables in patients treated with Lyon brace were 13.75±0.88 years, and 61.7˚±6.6˚, respectively. Then, the significant variables in brace therapy (baseline characters) were matched between the two groups. They included age, height, weight, Body Mass Index (BMI), and initial Cobb angle. The relevant data were compared by the Independent Samples t-test. Accordingly, there was no difference between the two groups in terms of the characteristics mentioned above (Table 1).
The in-brace follow-up visit was conducted approximately 2 months after the brace fitting session. The in-brace correction was measured by the Cobb angle differences before starting brace therapy and 2 months later by comparing the X-ray images in two phases. Cobb mean values were 67.9˚±6.3˚ and 61.7˚±6.6˚ at the study onset in Milwaukee and Lyon groups, respectively. However, there was no significant difference in this regard (P=0.291). Moreover, both groups were identical in terms of initial Cobb angles. Overall, X-ray images suggested correction in all patients 2 months after wearing the brace (P=0.001). Thus, both brace types created correction with a similar outcomes. However, Cobb mean values were 42.9˚±10.5˚ and 42.4˚±7.9˚ at follow-up phase in Milwaukee and Lyon groups, respectively. Therefore, there was no significant difference between the groups (0.282) (Table 2).
The prescribed braces were advised to be worn for 18-22 hours per day. Diary time was calculated by manually aggregating daily worn time from the patient diary. The compliance reported as the percentage variable of reported hours brace wear by patients versus the prescribed hours. The adherence determined from the hours reported in the Lyon group was 76.25±7.50. This value was higher than that of the Milwaukee group (65.60±18.40). Additionally, a difference was detected in the mean score of compliance between the two groups (P=0.044). The obtained results suggested that patients prefer to wear Lyon brace (Table 2).
In the present study, QoL was measured by the QLPSD questionnaire. The collected overall and subset scores are presented in Table 2. The overall obtained score was higher in the Milwaukee group (62.7±.97), compared with the Lyon group (51.13±6.8). Significant differences were observed in this regard (P=0.018). Furthermore, QoL was more impaired by the Milwaukee brace, in comparison with the Lyon brace. Using the same model, significant differences were found between the two groups regarding the QLPSD domains’ mean scores on psychosocial functioning (P=0.002), and back flexibility (P=0.015). Psychosocial functioning was related to the mental situation; however, back flexibility was related to the physical region. Therefore, comparing the mean score of two subsets revealed more biopsychological impairment of Milwaukee brace, compared with Lyon brace (Table 2).
4. Discussion
The current study explored the most significant factors in Milwaukee and Lyon brace to approach appropriate orthotic treatment. As a result, we assessed in-brace correction, compliance, and effects of braces on the study patients’ QoL. An in-brace correction could predict the success rate of brace treatment [36]. Landaurer et al. [27] suggested that an initial correction of ˃40% and in compliance had significant effects on treatment outcomes. In the present study, orthotic treatment with a Milwaukee brace had almost the same treatment outcome as Lyon brace. The obtained results also indicated that Lyon brace, as TLSO, surrounds the low surface of the trunk which was identical to Milwaukee brace (as CTLSO and high surroundings). Moreover, a positive impact on in-brace correction in TLSO, compared with the Milwaukee brace, was observed by Uden and associates [37]. However, Gutowski and Renshaw [16] reported reverse results in terms of comparing TLSO and Milwaukee braces. Besides, the age of their study population (juvenile 3-9-year-olds) also differed with the present study. Patients are interested in wearing a brace with the most possible comfort that encompasses the low surface of the trunk.
Surrounding all of the trunk and having cervical ring is an annoyed factor in Milwaukee brace that prevent wearing it as per the prescribed time; it also reevaled similar treatment outcomes as TLSO. The low compliance of spinal bracing with hyperkyphosis is an ongoing problem with the orthotic treatment. In the present study, such compliance was reported subjectively by the study participants. The achieved results indicated that highly compliant patients wore the Lyon brace as per the prescribed hours. The possible explanation for higher compliance in the Lyon group is related to its appearance and the lack of cervical rings that provide better compliance. Moreover, the appearance and construction of brace significantly affect the patient’s compliance. Patients’ cooperation in the brace design process helps reduce negative emotions. The co-design by patients concept can be introduced in the first patient-orthotist meeting; it could provide an opportunity for patients to select their favorite color and design.
Brace therapy affects emotional situations, social relations, and psychological reactions. These behaviors are related to QoL. The present study measured the QoL using the QLPSD instrument. This instrument measured psychosocial functioning, sleep disturbance, back pain, body image, and back flexibility. Such data were compared between the Milwaukee and Lyon brace user groups. The QLPSD is a useful instrument to test patients` mental (psychosocial function, body image), and physical (sleep disturbance, back pain, back flexibility) states.
Both brace groups reported the braces’ negative impacts on their overall QoL. We observed different QoL scores in the two groups, and the impairment was higher with the Milwaukee brace. Milwaukee group also indicated more impairment in psychosocial functioning, compared to the Lyon group. The brace’s appearance significantly impacts individuals’ mental state. Setting a counseling session in the treatment plane can provide education to patients and their parents regarding brace therapy concerning the psychological aspect and a safe environment. The present study indicated that the back flexibility of the physical aspect was different between the two brace groups.
Moreover, the back was more restricted in the Milwaukee group. The possible explanation for such difference is that the Milwaukee brace contains superior (cervical ring) and inferior ends (pelvic basket). It also surrounds patients trunk stiff by supra structural. Therefore, this brace decreases the flexibility and motions of the trunk. However, the lack of cervical ring and pelvic girdle in Lyon brace provides more space for patients' physical state, especially back flexibility according to the similarity of in-brace correction between the two brace groups.
5. Conclusion
This study provided data on the factors affecting brace therapy, such as in-brace correction, compliance, and QoL in thoracic hyperkyphosis participants. Lyon brace, compared to the Milwaukee brace, is more preferred among patients. The two groups demonstrated comparable results in brace correction. However, high compliance and low impaired QoL were observed in the Lyon group. Evaluating significant factors in the treatment plan can improve brace treatment outcomes. Further investigations are essential to design a plan for brace treatment, considering the structure and appearance of brace, patients' cooperation, and co-design in construction processes. Moreover, they should pay more attention to patients' mental aspects.
Ethical Considerations
Compliance with ethical guidelines
Research involving human participants. All ethical principles were considered in this article. The participants were informed about the purpose of the research and its implementation stages; they were also assured about the confidentiality of their information; moreover, they were allowed to leave the study whenever they wish, and if desired, the results of the research would be available to them.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Authors' contributions
Conceptualization and Supervision: Reza Vahab Kashani, Farhoud Saeid Ershadi; Methodology: Masoud Karimlo; Investigation: Sara Rahimi; Writing-original draft and Resources: Reza Vahab Kashani, Farhoud Saeid Ershadi, Masoud Karimlo, Sara Rahimi; Writing-Review & editing: Reza Vahab Kashani, Farhoud Saeid Ershadi, Masoud Karimlo.
Conflict of interest
The authors declared no conflict of interest.
References
Tribus CB. Scheuermann’s kyphosis in adolescents and adults: Diagnosis and management. Journal of the American Academy of Orthopaedic Surgeons. 1998; 6(1):36-43. [DOI:10.5435/00124635-199801000-00004] [PMID]
Lowe T. Scheuermann disease. Journal of Bone and Joint Surgery. 1990; 72(6):940-5. [DOI:10.2106/00004623-199072060-00026]
Mehdikhani M, Behtash H, Ganjavian MS, Abu Osman NA, Khalaj N. Treatment stability of Milwaukee brace in idiopathic hyperkyphosis. Prosthetics and Orthotics International. 2014; 38(4):316-20. [DOI:10.1177/0309364613499063] [PMID]
Holt R, Dopf C, Isaza J, Rahn K, Crawford M, Kostuik J. Adult kyphosis: The adult spine. Philadelphia, PA: Lipppincott-Raven. 1997.
Graat HC, van Rhijn LW, Schrander-Stumpel CT, van Ooij A. Classical Scheuermann disease in male monozygotic twins: Further support for the genetic etiology hypothesis. Spine. 2002; 27(22):E485-7. [DOI:10.1097/00007632-200211150-00020] [PMID]
Oei L, El Saddy S, Makurthou A, Castaño-Betancourt M, Estrada K, Hofman A, et al. Genetic epidemiology of Scheuermann’s disease. Osteoarthritis and Cartilage. 2013; 21:S171. [DOI:10.1016/j.joca.2013.02.367]
Damborg F, Engell V, Andersen M, Kyvik KO, Thomsen K. Prevalence, concordance, and heritability of Scheuermann kyphosis based on a study of twins. Journal of Bone and Joint Surgery. 2006; 88(10):2133-6. [DOI:10.2106/JBJS.E.01302]
De Mauroy J, Weiss H, Aulisa A, Aulisa L, Brox J, Durmala J, et al. 7th SOSORT consensus paper: conservative treatment of idiopathic & Scheuermann’s kyphosis. Scoliosis. 2010; 5(1):9. [DOI:10.1186/1748-7161-5-9] [PMID] [PMCID]
Bradford DS, Moe J, Winter R. Kyphosis and postural round back deformity in children and adolescents. Minnesota Medicine. 1973; 56(2):114-20.
Bradford DS, Moe JH, Montalvo FJ, Winter RB. Scheuermann’s kyphosis and round back deformity: Results of Milwaukee brace treatment. Journal of Bone and Joint Surgery. 1974; 56(4):740-58. [DOI:10.2106/00004623-197456040-00009]
Arlet V, Schlenzka D. Scheuermann’s kyphosis: Surgical management. European Spine Journal. 2005; 14(9):817-27. [DOI:10.1007/s00586-004-0750-0] [PMID]
Lindeman M, Behm K. Cognitive strategies and self-esteem as predictors of brace-wear noncompliance in patients with idiopathic scoliosis and kyphosis. Journal of Pediatric Orthopaedics. 1999; 19(4):493-9. [DOI:10.1097/01241398-199907000-00013] [PMID]
Gutowski WT, Renshaw TS. Orthotic results in adolescent kyphosis. Spine. 1988; 13(5):485-9. [DOI:10.1097/00007632-198805000-00009] [PMID]
Wenger DR, Frick SL. Scheuermann kyphosis. Spine. 1999; 24(24):2630. [DOI:10.1097/00007632-199912150-00010] [PMID]
Poolman R, Been H, Ubags L. Clinical outcome and radiographic results after operative treatment of Scheuermann’s disease. European Spine Journal. 2002; 11(6):561-9. [DOI:10.1007/s00586-002-0418-6] [PMID]
Montgomery SP, Erwin WE. Scheuermann’s kyphosis-long-term results of Milwaukee braces treatment. Spine. 1981; 6(1):5-8. [DOI:10.1097/00007632-198101000-00002] [PMID]
Hart ES, Merlin G, Harisiades J, Grottkau BE. Scheuermann’s thoracic kyphosis in the adolescent patient. Orthopaedic Nursing. 2010; 29(6):365-71. [DOI:10.1097/NOR.0b013e3181f83761] [PMID]
Lowe TG, Line BG. Evidence based medicine: analysis of Scheuermann kyphosis. Spine. 2007; 32(19):S115-9. [DOI:10.1097/BRS.0b013e3181354501] [PMID]
Ristolainen L, Kettunen J, Heliövaara M, Kujala U, Heinonen A, Schlenzka D. Untreated Scheuermann’s disease: A 37-year follow-up study. European Spine Journal. 2012; 21(5):819-24. [DOI:10.1007/s00586-011-2075-0] [PMID] [PMCID]
Willner S. Effect of the Boston thoracic brace on the frontal and sagittal curves of the spine. Acta Orthopaedica Scandinavica. 1984; 55(4):457-60. [DOI:10.3109/17453678408992394] [PMID]
Riddle E, Bowen J, Shah S, Moran E, Lawall JH. The duPont kyphosis brace for the treatment of adolescent Scheuermann kyphosis. Journal of the Southern Orthopaedic Association. 2003; 12(3):135-40.
Weiss H-R, Turnbull D, Bohr S. Brace treatment for patients with Scheuermann’s disease: A review of the literature and first experiences with a new brace design. Scoliosis. 2009; 4(1):22. [DOI:10.1186/1748-7161-4-22] [PMID] [PMCID]
Murray PM, Weinstein SL, Spratt KF. The natural history and long-term follow-up of Scheuermann kyphosis. Journal of Bone and Joint Surgery. 1993; 75(2):236-48. [DOI:10.2106/00004623-199302000-00011] [PMID]
de Mauroy JC, Vallèse P, Fender P, Lecante C. Historical Lyonaise brace treatment for adolescent hyperkyphosis: Results of 272 cases reviewed 2 years minimum after removal of the brace. Scoliosis. 2010; 5(1):O69. [DOI:10.1186/1748-7161-5-S1-O69] [PMCID]
de Mauroy JC, Lecante C. Reference Manual for the Lyon Scoliosis Brace [Internet]. Availble from: https://www.yumpu.com/en/document/read/32754439/reference-manual-for-the-lyon-scoliosis-brace
Chan SL, Cheung KM, Luk KD, Wong KW, Wong MS. A correlation study between in-brace correction, compliance to spinal orthosis and health-related quality of life of patients with Adolescent Idiopathic Scoliosis. Scoliosis. 2014; 9(1):1. [DOI:10.1186/1748-7161-9-1] [PMID] [PMCID]
Landauer F, Wimmer C, Behensky H. Estimating the final outcome of brace treatment for idiopathic thoracic scoliosis at 6-month follow-up. Pediatric Rehabilitation. 2003; 6(3-4):201-7. [DOI:10.1080/13638490310001636817] [PMID]
Katz DE, Durrani A. Factors that influence outcome in bracing large curves in patients with adolescent idiopathic scoliosis. Spine. 2001; 26(21):2354-61. [DOI:10.1097/00007632-200111010-00012] [PMID]
Donzelli S, Zaina F, Negrini S. In defense of adolescents: They really do use braces for the hours prescribed, if good help is provided; Results from a prospective everyday clinic cohort using thermobrace. Scoliosis. 2012; 7(1):12. [DOI:10.1186/1748-7161-7-12] [PMID] [PMCID]
Weinstein SL, Dolan LA, Wright JG, Dobbs MB. Effects of bracing in adolescents with idiopathic scoliosis. New England Journal of Medicine. 2013; 369(16):1512-21. [DOI:10.1056/NEJMoa1307337] [PMID] [PMCID]
Negrini S, Grivas TB, Kotwicki T, Maruyama T, Rigo M, Weiss HR. Why do we treat adolescent idiopathic scoliosis? What we want to obtain and to avoid for our patients: SOSORT 2005 Consensus paper. Scoliosis. 2006; 1(1):4. [DOI:10.1186/1748-7161-1-4] [PMID] [PMCID]
Korovessis P, Zacharatos S, Koureas G, Megas P. Comparative multifactorial analysis of the effects of idiopathic adolescent scoliosis and Scheuermann kyphosis on the self-perceived health status of adolescents treated with brace. European Spine Journal. 2007; 16(4):537-46. [DOI:10.1007/s00586-006-0214-9] [PMID] [PMCID]
Apter A, Morein G, Munitz H, Tyano S, Maoz B, Wijsenbeek H. The psychosocial sequelae of the Milwaukee brace in adolescent girls. Clinical Orthopaedics and Related Research. 1978; 131:156-9. [DOI:10.1097/00003086-197803000-00021]
Motlagh FR, Kamali M, Babaee T. Persian adaptation of Quality of Life Profile for Spinal Deformities questionnaire. Journal of Back and Musculoskeletal Rehabilitation. 2017; 31(5):1-6. [DOI:10.3233/BMR-169775]
Climent JM, Reig A, Sánchez J, Roda C. Construction and validation of a specific quality of life instrument for adolescents with spine deformities. Spine. 1995; 20(18):2006-11. [DOI:10.1097/00007632-199509150-00011] [PMID]
Andrews G, MacEwen GD. Idiopathic scoliosis: An 11-year follow-up study of the role of the Milwaukee brace in curve control and trunco-pelvic alignment. Orthopedics. 1989; 12(6):809-16. [PMID]
Udén A, Willner S, Pettersson H. Initial correction with the Boston thoracic brace. Acta Orthopaedica Scandinavica. 1982; 53(6):907-11. [DOI:10.3109/17453678208992847] [PMID]