|Year : 2017 | Volume
| Issue : 1 | Page : 19-29
Quality of life of children with lower limb deformities: A systematic review of patient-reported outcomes and development of a preliminary conceptual framework
Harpreet Chhina1, Anne Klassen2, Jacek Kopec3, Sujin Park4, Cadi Fortes4, Anthony Cooper5
1 Department of Experimental Medicine, Faculty of Medicine, University of British Columbia; Department of Orthopaedics, BC Children's Hospital, Vancouver, BC, Canada
2 Department of Pediatrics and Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
3 Arthritis Research Centre of , Richmond, BC; School of Population and Public Health, University of British Columbia, Canada
4 Department of Orthopaedics, BC Children's Hospital, Vancouver, BC, Canada
5 Department of Experimental Medicine, Faculty of Medicine, University of British Columbia; Department of Orthopaedics, BC Children's Hospital, Vancouver, BC, ; Department of Orthopaedics, University of British Columbia, Columbia, Vancouver, BC, Canada
|Date of Web Publication||15-Mar-2017|
1D 64, 4480 Oak Street, Department of Orthopaedics, BC Children's Hospital, Vancouver BC
Source of Support: None, Conflict of Interest: None
Background: Lower limb deformities have a substantial impact on the quality of life (QOL) of children. This systematic review was conducted to identify as follows: (a) QOL concepts in existing literature specific to pediatric patients with lower limb deformities; (b) parent-reported outcome and patient-reported outcome (PRO) instruments used to measure QOL in pediatric patients with lower limb deformities; and (c) determinants of QOL in pediatric patients with lower limb deformities. Methods: MEDLINE, EMBASE, CINAHL, and PsycINFO were searched from the inception to January 2016. Studies were included if they (1) had patients with lower limb deformities; (2) included children 18 years of age or under; and (3) measured QOL using a PRO or parent-reported outcome of instruments. Results: Of the 938 publications identified in the search, 10 studies used a total of 24 PRO or parent-reported outcome instruments to measure 1 or more aspects of QOL of pediatric patients with lower limb deformities. Three overarching health concepts (physical, psychological, and social health) and 15 subconcepts were identified. Five studies looked at determinants of QOL including type of deformity, severity of deformity, complications postsurgery, stage of treatment, and type of treatment. Psychological health was measured in 10 studies, social health in 7 studies, and physical health in 6 studies. The most frequently measured subconcepts were physical function, psychological distress, and social function. Conclusion: Existing parent-reported outcome and PRO instruments measure 3 QOL concepts in children with lower limb deformities. There were no validated PRO instruments specifically designed to measure QOL of children with lower limb deformities.
Level of Evidence: This was a systematic review of level III studies.
Keywords: Conceptual framework, lower limb deformities, patient-reported outcomes, quality of life, systematic review
|How to cite this article:|
Chhina H, Klassen A, Kopec J, Park S, Fortes C, Cooper A. Quality of life of children with lower limb deformities: A systematic review of patient-reported outcomes and development of a preliminary conceptual framework. J Limb Lengthen Reconstr 2017;3:19-29
|How to cite this URL:|
Chhina H, Klassen A, Kopec J, Park S, Fortes C, Cooper A. Quality of life of children with lower limb deformities: A systematic review of patient-reported outcomes and development of a preliminary conceptual framework. J Limb Lengthen Reconstr [serial online] 2017 [cited 2018 Jun 21];3:19-29. Available from: http://www.jlimblengthrecon.org/text.asp?2017/3/1/19/202216
| Introduction|| |
Lower limb deformities describe a range of conditions that may be congenital or acquired. Congenital lower limb deformities include limb reduction defects, angular deformities, and rotational deformities. Acquired lower limb deformities may result from trauma or infection resulting in malunions, nonunions, or bone defects. Depending on the type of deformity, treatment options may include reconstructive or ablative surgery combined with the use of prosthetics and orthotics. Distraction osteogenesis principles for limb lengthening are increasingly being applied to treat lower limb deformities.,,,,,,,, Lower limb deformities often cause difficulties in physical functioning, leading to discomfort, pain, and gait disturbance., Dissatisfaction with appearance and/or function, along with the complex surgical procedures, can have impacts on quality of life (QOL).,,
It has been well-recognized that the focus of any treatment should not only be on physical health but also on mental health and social well-being; thus, clinical outcomes need to be complemented by patient-centered outcomes to evaluate interventions., Having a patient-reported outcome (PRO) instrument to measure QOL in children with lower limb deformities is crucial for understanding the extent to which their condition affects their QOL, as well as evaluating the success of treatment and tailoring treatment plans to address patient concerns, preferences, and needs.,,,,,,,
The aims for this systematic review were to identify the following: (a) QOL concepts studied in existing literature specific to children with lower limb deformities; (b) PRO instruments used to measure QOL in children with lower limb deformities; and (c) determinants of QOL in children with lower limb deformities as studied in the existing literature.
| Methods|| |
We conducted our review under the guidance of a medical librarian and followed the PRISMA statement. MEDLINE, EMBASE, CINAHL, and PsycINFO databases were searched from inception of each to January 2016 (full search strategy available from HC).
The following inclusion criteria were used: (1) study population included patients with lower limb deformities; (2) mean age for participants was 18 years or under; and (3) study used a PRO or parent-reported outcome instrument to measure one or more aspects of QOL, including any ad hoc PRO instruments. For the purpose of this study, lower limb deformities included lower limb reduction defects, lower limb length discrepancy, and associated angular and rotational deformities. Isolated knee, foot and ankle conditions without any limb length discrepancy or limb deformity were not classified as lower limb deformity for this study. Exclusion criteria were as follows: (1) studies where children with other health conditions were included in the sample, and the results for the lower limb deformities sample were not presented separately; (2) studies that included conditions that could likely affect the lower limb (such as osteogenesis imperfecta, skeletal dysplasia, bone tumors, and multiple exostoses), but results for lower limbs were not presented separately; (3) mean age for the sample was over 18 years; and (4) publication was a review paper, an abstract or a letter to editor.
Titles and abstracts were independently screened by two reviewers (HC, CF). A third reviewer (AC) was consulted to reach consensus when required. Two reviewers independently inspected the full text of the articles that had been deemed potentially applicable and extracted data from those that met the inclusion criteria. References of included publications were inspected for additional papers. No quality assessment was performed since our goal was to identify PRO instruments used and health concepts measured for children with lower limb deformities.
An original copy of each instrument was obtained. Each instrument was examined to generate a list of health concepts and subconcepts measured. This list was compared with the health concepts and subconcepts as measured by the publication included in our systematic review. Similar subconcepts were categorized into one overarching subconcept. For example, physical activities, walking, recreational activities, transfer and basic mobility, stiffness, and sports were grouped under subconcept physical function (PF). These subconcepts were further categorized into 3 major health concepts (physical, psychological, and social health). In the aforementioned example, PF was classified under the concept physical health along with pain and general health (GH).
We also collected the following data on determinants of QOL from the studies included in this systematic review: name of the determinant, direction of its relationship with the health subconcept, and whether this relationship was statistically significant (i.e., P < 0.05). However, we report only on the determinants that were reported to have a statistically significant relationship with QOL subconcepts in that study.
| Results|| |
Our search identified 938 publications [Figure 1]. Five publications met our inclusion criteria. A citation review added 5 additional publications, for a total of 10 publications [Table 1].,,,,,,,,, QOL was measured using 30 parent-reported outcome or PRO instruments [Appendix 1 [Additional file 1]]. Three instruments (CDI, PedsQL, and STAI) were used as more than one version (i.e., short/long, different age groups, general/specific diagnoses). For example, two versions (regular and short form) of CDI were used, two versions of PedsQL (core and neuromuscular module) were used, and the STAI was used in 2 papers as Form C and Form Y. Consolidating multiple versions left 27 instruments, of which 1 was an interview, and 2 were nonvalidated questionnaires., Thus, considering only distinct, validated questionnaires, QOL was measured using 24 different instruments [Table 2]. Out of the 24 instruments, 14 were patient-reported, 7 were parent-reported, and 3 were both patient- and parent-reported instruments. Two studies used only patient reports,, 6 studies used both patient- and parent proxy-reports ,,,,, while 2 studies used parent reports only.,
Of these 24 instruments, only 2, AAOS Lower Limb Outcomes Questionnaire. Lower Limb Questionnaire, were lower limb specific. However, the Lower Limb Questionnaire was not specific to the pediatric population, and the Lower Limb Questionnaire was only parent-reported. Four instruments (PedsQL, CHQ PF-28, PODCI, and Kidscreen) measured multiple aspects of health.
We found that most studies included in our systematic review used the same concepts and subconcepts as the original instrument with slight modifications in language. The concepts and subconcepts from the instruments identified were used to develop a preliminary conceptual framework [Figure 2]. Three health concepts identified were physical, psychological, and social health, with 15 subconcepts.
Five studies examined the determinants of QOL for children with lower limb deformities [Table 3].,,,, Five determinants that were reported to significantly affect the QOL were type of deformity, severity of deformity, complications postsurgery, stage of treatment, and type of treatment.
Physical health was measured by 10 instruments in 6/10 studies using 3 subconcepts , 27, ,,, including PF, GH, and pain. The most frequently measured subconcept was PF, measured in 6/6 studies, using 9 instruments. GH was measured in 3/6 studies, using 4 instruments.,, Three studies measured pain using 5 instruments.,, PF in children with lower limb deformities was found to be lower than the normative population in 4 out of 6 studies.,,,
Determinants of physical health reported in 3 studies ,, were type of deformity, type of treatment, and stage of treatment. Lee et al. looked at the parental perspectives of their child's limb length discrepancy and found that children with idiopathic leg length discrepancy (LLD) experienced less pain and better global functioning as compared to children with posttraumatic LLD. The authors defined idiopathic limb length discrepancy as limb length discrepancy without identifiable causes (i.e., not infection, tumor, vascular diseases, congenital anomaly, Legg–Calve–Perthes disease, and neurofibromatosis). PF was found to be more affected in the surgery group in comparison with the nonsurgery group for children undergoing limb lengthening surgery for achondroplasia. In a study of 52 patients who underwent external fixator treatment for their lower limb deformities, Montpetit et al. found that PF was better preoperatively compared to mid-distraction, whereas at 3 months after frame removal, PF was better than at mid-distraction.
All 10 studies included in this systematic review measured psychological health using 21 instruments measuring 8 subconcepts, making it the most frequently studied concept. These subconcepts were emotions, psychological distress, cognition, satisfaction with appearance, self-esteem, treatment expectations, coping, and behavior. Psychological distress was the most frequently studied subconcept, measured in 8/10 studies using 11 instruments.,,,,,,, Emotions were measured in 4 studies using 4 instruments.,,, Cognition was measured in 4 studies using 5 instruments.,,, Satisfaction with appearance was measured in 2 studies using 2 instruments., Behavior was measured in 4 studies using 5 instruments.,,, Self-esteem was measured in 6 studies using 6 instruments.,,,,, Coping and treatment expectations were measured in 1 study each using Kidcope  and PODCI, respectively.
Three studies reported that psychological distress levels were normal in children and adolescents with lower limb deformities both pre-, and post-operatively., Another study found psychological distress preoperatively to be higher in children undergoing leg lengthening surgery when compared to children undergoing cosmetic ear surgery as well as a control group of school children. More aggressive behavior and thought-related problems were reported in children undergoing limb lengthening for LLD compared to children in the control group using the Child Behavior Checklist. Patients with LLD were also found to have lower self-esteem and more psychological distress preoperatively compared to a control group of school children and more emotional and cognition issues  compared to the normative population. Conversely, 2 studies found behavior to be normal in children with lower limb deformities., A study involving 45 children with lower limb deformities found that the behavior of these children, as measured by the parent-reported Post Hospitalization Behavior Questionnaire, was within the normal range. Bond et al. found that children with lower limb deformities awaiting limb reconstruction surgery had normal behavior as measured by the parent-reported Personal Adjustment and Role Skills Scale as compared to healthy children.
Determinants of psychological health investigated in 3 studies ,, were complications postsurgery, type of treatment, and stage of treatment. Significantly higher self-esteem was found in patients with achondroplasia who underwent limb lengthening versus nonsurgical patients. Fewer complications postlimb lengthening surgery was associated with higher self-esteem compared to children who experienced more complications postsurgery. Emotional functioning scores were higher 3 months following frame removal versus preoperatively, suggesting improved QOL in children undergoing external fixator treatment for their lower limb deformities. There was no difference found in the levels of psychological distress pre- versus post-operatively in children and adolescents after Ilizarov leg lengthening.
Social health was studied in 7/10 studies using 10 instruments.,,,,,, The subconcepts measured were family, peer relations (PRs), school, and social function (SF). SF was the most frequently measured subconcept in 6/7 studies using 8 instruments., 26, ,,, Five studies measured the subconcept family using 5 instruments.,,,, Some aspects of family measured in these studies were family activities, family cohesion, family conflicts, parental satisfaction, and family finances. The subconcepts PR , and school , were measured in 2 studies each. PR included aspects such as bullying, social acceptance from peers, support from friends, and PRs.
SF was found to be significantly lower than the normal population in children with LLD  and congenital lower limb deficiencies. However, Bond et al. found SF to be normal in children with lower limb deformities as compared to the normal reference population. Lower limb deformities had no effect on family as measured by the Family Environment Scale. The Child Health Questionnaire (CHQ) showed significant effects on families of children with an LLD. In terms of PR, there was no significant difference between the study population and normative scores, as measured by the parent-reported Personal Adjustment and Role Skills Scale. Children with lower limb deformities were not found to have significantly different scores relative to a control group of school children in academic performance at school.
Determinants found to be significantly related to social health in 2 studies , included severity of deformity, type of deformity, and stage of treatment. SF was found to be better 3 months postframe removal as compared to preoperatively in children undergoing treatment with an external fixator for their lower limb deformities. Children with nonidiopathic lower limb deformities scored significantly lower than children with idiopathic lower limb deformities on the subconcept family, suggesting higher impact on parental emotions and family activities as measured by the CHQ-Parent form. This study also found that a limb length discrepancy of 2 centimeters or more had a negative impact on SF, parental emotions, and family activities.
| Discussion|| |
This systematic review was conducted to synthesize the available evidence on the assessment of QOL of children with lower limb deformities using PRO instruments. We found that there were no validated PRO instruments specifically designed to measure QOL of children with lower limb deformities.
The existing instruments that are widely used in pediatric orthopedics either measure the physical/functional aspects of the lower limb and are developed for an adult population  or are not lower limb specific. QOL of children with lower limb deformities has been measured using either a generic , or a parent-reported QOL instrument. More recently, Fabricant et al. have modified and validated the Scoliosis Research Society instrument for assessing QOL of adults with lower limb deformities. In spite of this, there is still a need for patient-reported QOL questionnaire for children and adolescents with lower limb deformities.
We identified one instrument for parents of children with LLD. The content for this 34-item questionnaire was generated from a literature review and interviews with 58 parents of children aged 6–20 years. This questionnaire measures parental satisfaction, effect of LLD, preferred treatment, parent's mood, and concerns and parental expectations regarding the treatment. There is currently limited psychometric information (content validity and internal consistency only) about the performance of this questionnaire. More research is needed that looks at other scale characteristics, for example, test-retest reliability, construct validity, or responsiveness.,
Giving voice to children to express their concerns about their life with lower limb deformities is important in developing an instrument to measure their QOL. The assumption that children are unreliable respondents about their QOL, due to lack of linguistic, reading, and cognitive skills, is increasingly being challenged. In general, good agreement has been found between child and parent reports for domains of physical activity, functioning and symptoms, but for emotional and social domains, poor agreement has been found. Discrepancies known as cross-informant variance  between parent's and patient's own perspective of QOL has been consistently documented in several studies of QOL in both children with chronic health conditions and healthy children., Hence, both children and parent proxy-reports should be incorporated to completely understand the complex and multidimensional construct of QOL.,
Our systematic review identified determinants reported to have a statistically significant relationship with some aspect of QOL of children with lower limb deformities. However, there could be a number of other factors not identified in these previous studies that influence the QOL of these children. Social support, family functioning, self-perceptions of appearance, school, behavior, athletics, and social competence are some of the determinants affecting the self-esteem of children with limb deficiencies in general. As such, there is a lack of information on determinants of QOL of children with lower limb deformities in the existing literature. Hence, future studies need to specifically aim at collecting information on determinants of QOL for this specific population.
We identified that 24 instruments used to measure QOL in children with lower limb deformities measured a wide range of concepts (3 concepts and 15 subconcepts). This variation indicates the lack of consensus on subconcepts important for assessing QOL for these children. Even for the most frequently measured subconcept of psychological distress, there were 11 different instruments used. The heterogeneity in instruments used for QOL measurement also highlights the potential difficulty encountered while generalizing results across studies. Furthermore, there are other previously identified challenges while conducting PRO research with children and adolescents which makes outcome assessment and generalization of the results more challenging in general. Some of these challenges are due to developmental differences in various age groups, age-related vocabulary, and comprehension of health concepts  which makes outcomes assessment and generalizing the results more challenging in general. Outcomes assessment is further complicated in lower limb deformities due to the lack of a universally accepted classification system for assessing lower limb deformities. However, the classification system developed by the Limb Lengthening and Reconstruction Society (LLRS-AIM classification) has been introduced to address this deficiency.
Hence, we aim to develop a new patient-reported QOL instrument, which has been systematically developed by following international guidelines for PRO development,, psychometrically tested and is clinically meaningful. Development of a PRO instrument is an iterative process with the first step being the development of a preliminary conceptual framework of concepts and subconcepts important to the target population. We used the preliminary conceptual framework derived from our systematic review to inform our interview guide for qualitative interviews with children with lower limb deformities and their parents. We have established an international multidisciplinary collaboration involving five centers across Canada, Ethiopia, India, and the USA to develop our QOL questionnaire. Our qualitative phase is well under way with 37 interviews conducted to date. Our qualitative phase also consists of novel methodologies such as photo elicitation interviews to overcome linguistic barriers of our young patient population. Item generation and scale development will be followed by cognitive debriefing interviews with children from the five participating centers. Expert opinion will be obtained from our established multidisciplinary collaborative team which consists of orthopedic surgeons, nurses, occupational therapists, physiotherapists, psychologists and experts in the field of PRO development, and QOL studies. Expert opinion from members of relevant specialist societies will be sort. Field testing, psychometric analysis, and cross-cultural validation will be done across all five participating centers. Following the ISPOR PRO, good research practices guidelines and acknowledging the challenges associated with using one outcome assessment for both children and adolescents, we aim to develop age-appropriate questionnaires. We will develop separate QOL questionnaires for age groups 8–12 years and 13–18 years.
Once developed, this PRO instrument could be used to measure the success of various treatment options for children with lower limb deformities to aid clinical decision-making, including type and timing of surgery, and patients/parent counseling.
| Conclusion|| |
Existing parent-reported outcome and PRO instruments measure 3 QOL concepts in children with lower limb deformities. There were no validated PRO instruments specifically designed to measure QOL of children with lower limb deformities.
Financial support and sponsorship
Financial support and sponsorship
This study was supported by Orthopaedics Research Excellence Funds, Department of Orthopaedics, University of British Columbia. The senior author (Anthony Cooper) is supported by the Investigator Grant Award Program by the BC Children's Hospital, Vancouver, BC.
Conflicts of interest
There are no conflicts of interest.
| References|| |
Rozbruch SR, Herzenberg JE, Tetsworth K, Tuten HR, Paley D. Distraction osteogenesis for nonunion after high tibial osteotomy. Clin Orthop Relat Res 2002;394:227-35.
Ghoneem HF, Wright JG, Cole WG, Rang M. The Ilizarov method for correction of complex deformities. Psychological and functional outcomes. J Bone Joint Surg Am 1996;78:1480-5.
Hutchinson RJ, Betts RP, Donnan LT, Saleh M. Assessment of Ilizarov correction of club-foot deformity using pedobarography. A preliminary report. J Bone Joint Surg Br 2001;83:1041-5.
Ilizarov GA. The tension-stress effect on the genesis and growth of tissues. Part I. The influence of stability of fixation and soft-tissue preservation. Clin Orthop Relat Res 1989;238:249-81.
De Bastiani G, Aldegheri R, Renzi-Brivio L, Trivella G. Limb lengthening by callus distraction (callotasis). J Pediatr Orthop 1987;7:129-34.
Jordan CJ, Goldstein RY, McLaurin TM, Grant A. The evolution of the Ilizarov technique: Part 1: The history of limb lengthening. Bull Hosp Jt Dis 2013;71:89-95.
Spiegelberg B, Parratt T, Dheerendra SK, Khan WS, Jennings R, Marsh DR. Ilizarov principles of deformity correction. Ann R Coll Surg Engl 2010;92:101-5.
LaBianco GJ, Vito GR, Kalish SR. Use of the Ilizarov external fixator in the treatment of lower extremity deformities. J Am Podiatr Med Assoc 1996;86:523-31.
Ilizarov GA. The tension-stress effect on the genesis and growth of tissues: Part II. The influence of the rate and frequency of distraction. Clin Orthop Relat Res 1989;239:263-85.
Ramaker RR, Lagro SW, van Roermund PM, Sinnema G. The psychological and social functioning of 14 children and 12 adolescents after Ilizarov leg lengthening. Acta Orthop Scand 2000;71:55-9.
Kaufman KR, Miller LS, Sutherland DH. Gait asymmetry in patients with limb-length inequality. J Pediatr Orthop 1996;16:144-50.
Bond JM, Kent GG, Binney VA, Saleh M. Psychological adjustment of children awaiting limb reconstruction treatment. Child Care Health Dev 1999;25:313-21.
Hrutkay JM, Eilert RE. Operative lengthening of the lower extremity and associated psychological aspects: The Children's Hospital experience. J Pediatr Orthop 1990;10:373-7.
Varni JW, Burwinkle TM, Lane MM. Health-related quality of life measurement in pediatric clinical practice: An appraisal and precept for future research and application. Health Qual Life Outcomes 2005;3:34.
Slevin ML, Plant H, Lynch D, Drinkwater J, Gregory WM. Who should measure quality of life, the doctor or the patient? Br J Cancer 1988;57:109-12.
Nelson E, Conger B, Douglass R, Gephart D, Kirk J, Page R, et al.
Functional health status levels of primary care patients. JAMA 1983;249:3331-8.
Wasson JH, Stukel TA, Weiss JE, Hays RD, Jette AM, Nelson EC. A randomized trial of the use of patient self-assessment data to improve community practices. Eff Clin Pract 1999;2:1-10.
Nelson EC, Eftimovska E, Lind C, Hager A, Wasson JH, Lindblad S. Patient reported outcome measures in practice. BMJ 2015;350:g7818.
Barry MJ, Edgman-Levitan S. Shared decision making – Pinnacle of patient-centered care. N Engl J Med 2012;366:780-1.
Zhao D, Rao W, Zhao L, Liu J, Chen Y, Shen P, et al.
Is it worthwhile to screen the hip in infants born with clubfeet? Int Orthop 2013;37:2415-20.
Marshall S, Haywood K, Fitzpatrick R. Impact of patient-reported outcome measures on routine practice: A structured review. J Eval Clin Pract 2006;12:559-68.
Santana MJ, Feeny D. Framework to assess the effects of using patient-reported outcome measures in chronic care management. Qual Life Res 2014;23:1505-13.
Valderas JM, Kotzeva A, Espallargues M, Guyatt G, Ferrans CE, Halyard MY, et al.
The impact of measuring patient-reported outcomes in clinical practice: A systematic review of the literature. Qual Life Res 2008;17:179-93.
Moher D, Liberati A, Tetzlaff J, Altman DG; PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med 2009;6:e1000097.
Kim SJ, Balce GC, Agashe MV, Song SH, Song HR. Is bilateral lower limb lengthening appropriate for achondroplasia? Midterm analysis of the complications and quality of life. Clin Orthop Relat Res 2012;470:616-21.
Lee KM, Chung CY, Gwon DK, Sung KH, Cho JH, Kim TW, et al.
Parental perspectives on leg length discrepancy. J Pediatr Orthop B 2012;21:146-9.
Martin L, Farrell M, Lambrenos K, Nayagam D. Living with the Ilizarov frame: Adolescent perceptions. J Adv Nurs 2003;43:478-87.
Michielsen A, van Wijk I, Ketelaar M. Participation and health-related quality of life of Dutch children and adolescents with congenital lower limb deficiencies. J Rehabil Med 2011;43:584-9.
Montpetit K, Hamdy RC, Dahan-Oliel N, Zhang X, Narayanan UG. Measurement of health-related quality of life in children undergoing external fixator treatment for lower limb deformities. J Pediatr Orthop 2009;29:920-6.
Niemelä BJ, Hedlund A, Andersson G, Wahlsten VS. Prominent ears: The effect of reconstructive surgery on self-esteem and social interaction in children with a minor defect compared to children with a major orthopedic defect. Plast Reconstr Surg 2008;122:1390-8.
Vitale MA, Choe JC, Sesko AM, Hyman JE, Lee FY, Roye DP Jr., et al.
The effect of limb length discrepancy on health-related quality of life: Is the '2 cm rule' appropriate? J Pediatr Orthop B 2006;15:1-5.
Johanson NA, Liang MH, Daltroy L, Rudicel S, Richmond J. American Academy of Orthopaedic Surgeons lower limb outcomes assessment instruments. Reliability, validity, and sensitivity to change. J Bone Joint Surg Am 2004;86-A: 902-9.
Daltroy LH, Liang MH, Fossel AH, Goldberg MJ. The POSNA pediatric musculoskeletal functional health questionnaire: Report on reliability, validity, and sensitivity to change. Pediatric Outcomes Instrument Development Group. Pediatric Orthopaedic Society of North America. J Pediatr Orthop 1998;18:561-71.
Fabricant P, Borst E, Green S, Marx R, Fragomen A, Rozbruch SR. Validation of a modified Scoliosis Research Society instrument for patients with limb deformity: The limb deformity-Scoliosis Research Society (LD-SRS) score. J Limb Lengthening Reconstr 2016;2:86. Available from: http://www.jlimblengthrecon.org/text.asp?2016/2/2/86/190710
. [Last accessed on 2017 Jan 31]
Scientific Advisory Committee of the Medical Outcomes Trust. Assessing health status and quality-of-life instruments: Attributes and review criteria. Qual Life Res 2002;11:193-205.
Theunissen NC, Vogels TG, Koopman HM, Verrips GH, Zwinderman KA, Verloove-Vanhorick SP, et al.
The proxy problem: Child report versus parent report in health-related quality of life research. Qual Life Res 1998;7:387-97.
Herjanic B, Herjanic M, Brown F, Wheatt T. Are children reliable reporters? J Abnorm Child Psychol 1975;3:41-8.
Varni JW, Katz ER, Colegrove R, Dolgin M. Adjustment of children with newly diagnosed cancer: Cross-informant variance. J Psychosoc Oncol 1995;13:23-38.
Varni JW, Katz ER, Seid M, Quiggins DJ, Friedman-Bender A, Castro CM. The Pediatric Cancer Quality of Life Inventory (PCQL). I. Instrument development, descriptive statistics, and cross-informant variance. J Behav Med 1998;21:179-204.
Chang PC, Yeh CH. Agreement between child self-report and parent proxy-report to evaluate quality of life in children with cancer. Psychooncology 2005;14:125-34.
Sherifali D, Pinelli J. Parent as proxy reporting: Implications and recommendations for quality of life research. J Fam Nurs 2007;13:83-98.
Eiser C, Morse R. A review of measures of quality of life for children with chronic illness. Arch Dis Child 2001;84:205-11.
Varni JW, Rubenfeld LA, Talbot D, Setoguchi Y. Determinants of self-esteem in children with congenital/acquired limb deficiencies. J Dev Behav Pediatr 1989;10:13-6.
Matza LS, Patrick DL, Riley AW, Alexander JJ, Rajmil L, Pleil AM, et al.
Pediatric patient-reported outcome instruments for research to support medical product labeling: Report of the ISPOR PRO good research practices for the assessment of children and adolescents task force. Value Health 2013;16:461-79.
McCarthy JJ, Iobst CA, Rozbruch SR, Sabharwal S, Eismann EA. Limb Lengthening and Reconstruction Society AIM index reliably assesses lower limb deformity. Clin Orthop Relat Res 2013;471:621-7.
U.S. Department of Health and Human Services FDA Center for Drug Evaluation and Research; U.S. Department of Health and Human Services FDA Center for Biologics Evaluation and Research; U.S. Department of Health and Human Services FDA Center for Devices and Radiological Health. Guidance for industry: Patient-reported outcome measures: Use in medical product development to support labeling claims: Draft guidance. Health Qual Life Outcomes 2006;4:79.
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]