SCIENTIFIC ARTICLE
Symptom Severity and Conservative Treatment for Carpal Tunnel Syndrome in Association With Eventual Carpal Tunnel Release Nancy A. Baker, MPH, Heather M. Livengood, MS
Purpose To study the relationship between the severity of carpal tunnel syndrome (CTS) symptoms and surgery for CTS and the relationship between conservative treatments and surgery for CTS. Methods A secondary analysis of baseline to 6-month data from a randomized controlled trial, which examined the effectiveness of orthosis/stretch combinations on the symptoms of CTS, was conducted for a total of 96 participants with CTS. Participants completed the Carpal Tunnel Questionnaire and posttreatment surveys. Statistical analyses included exploration of correlates of progression to surgery for CTS and logistical regression to examine the association between conservative treatments and CTS symptoms and progression to surgery for CTS. Results Twenty-one participants received surgery for their CTS, and 31 participants received 1 or more conservative treatments. Severity of baseline CTS symptoms and additional treatments were indicators of progression to surgery. The randomized controlled trial intervention was inversely associated with progression to surgery. Conclusions CTS that does not respond to an initial course of conservative treatment may not improve with additional treatments. More than half of the participants who received additional conservative treatment still progressed to surgery. Current intervention guidelines for CTS provide limited guidance as to the best methods to efficiently treat CTS. Clinical relevance CTS is a costly and high-burden disorder, resulting in reduced quality of life. Research should examine when and for whom conservative care is an effective choice and the association between conservative care and the eventual need for CTS surgery. (J Hand Surg Am. 2014;-:-e-. Copyright Ó 2014 by the American Society for Surgery of the Hand. All rights reserved.) Key words Carpal tunnel syndrome, rehabilitation, treatment, carpal tunnel release surgery.
C
(CTS) is the most common upper extremity neuropathy1 and repeated trauma work injury, affecting 10 million Americans annually.2 CTS is a high-burden disorder that reduces quality of life and costs billions of health ARPAL TUNNEL SYNDROME
care dollars.3e5 People with CTS experience symptoms and functional losses that affect their abilities to perform ordinary activities. In 2011, workers with CTS had a median 28 days away from work, which exceeded those for fractures, multiple injuries, and amputations.6
From the Department of Occupational Therapy, University of Pittsburgh, School of Health and Rehabilitation Sciences, Pittsburgh, PA.
No benefits in any form have been received or will be received related directly or indirectly to the subject of this article.
Received for publication January 15, 2014; accepted in revised form April 15, 2014.
Corresponding author: Heather M. Livengood, MS, 5012 Forbes Tower, Department of Occupational Therapy, University of Pittsburgh, Pittsburgh, PA 15260; e-mail: [email protected].
The authors acknowledge the support of the Arthritis Foundation: Eastern Pennsylvania Chapter for the grant that funded the parent study.
0363-5023/14/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.04.034
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1
2
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
METHODS Parent study The parent study examined the comparative effectiveness of orthosis/stretch combinations on CTS symptoms and function. Refer to Baker et al18 for the full study protocol. Briefly, participants were screened for and recruited primarily by 2 hand and upper extremity surgeons based on best practice for diagnosing CTS. Participants were randomized to 1 of 4 intervention groups that compared the effect of 4 possible combinations of types of orthosis (lumbrical orthosis [0 wrist extension, 0 e10 metacarpophalangeal {MCP} flexion] vs neutral wrist orthosis [0 wrist extension]) and stretches (lumbrical stretches versus general stretches). After randomization, an occupational therapist explained CTS, either fabricated a lumbrical orthosis or fitted a neutral wrist orthosis, and trained the participant in either lumbrical or general stretches. The parent study intervention was a 4-week home program during which time participants were instructed to wear their orthosis at night and to perform their stretches 6 times daily. Participants completed a daily log to track adherence to the study protocol. During the 4-week intervention, participants received no other treatment for CTS. After the 4-weeek home program, participants were instructed to continue to wear the orthosis and complete the stretches as needed. They received additional conservative treatment at the discretion of their physician as part of usual CTS care. Follow-up assessments were conducted at 3 and 6 months to track carryover effects of the parent study intervention.
Workers with CTS experienced wage loss during and after treatment, a cumulative loss of earnings of between $45,000 and $89,000 6 years after treatment.4 Current guidelines for CTS intervention provide limited guidance on the most efficient and best type of treatment.7 These guidelines suggest 1 or more courses of conservative treatment to reduce symptoms. Evidence suggests effective treatments typically have a measureable effect on symptoms within 2 to 7 weeks.7 Surgery is an option if conservative care is not successful. Conservative care is recommended to alleviate CTS, yet there is little guidance as to the best type of conservative treatment. Over a dozen treatments for CTS have been investigated.7e14 Several, such as corticosteroid injections and immobilization, are supported by moderate evidence. However, few studies have examined the association between conservative care and surgery. Boyd et al15 tracked 47 hands (25 patients) after they received 12 weeks of immobilization. Patients with 27 affected hands progressed to surgery within 6 months of treatment. Those who progressed to surgery reported higher symptoms and more impaired function at baseline and minimal improvement during treatment. Pomerance et al16 examined the cost effectiveness of surgical versus conservative care. Of the 60 patients who chose to receive 2 weeks of conservative treatment, 32 elected to have surgery during the following 12 months. Hall et al17 reported that, after an 8-week program of immobilization and education, 37% of their sample planned to receive surgery, and those patients had greater symptoms severity, functional deficits, pain, and longer symptom duration. These studies indicate that many patients receive surgery after conservative care but do not identify if more than 1 course of conservative treatment prevents progression to surgery. Hall et al17 closely examined risk factors for progression to surgery. This report is a secondary analysis to examine the relationship between indicators associated with progression to surgery up to 6 months following conservative treatment. The data were collected as part of a randomized controlled trial that examined the effectiveness of an orthosis/stretch combination for individuals with CTS.18 The incidence of surgery in the parent study was 26%. Two primary indicators were examined: the relationship between severity of CTS symptoms and surgery for CTS and the relationship between additional conservative treatments and surgery for CTS. Additional conservative treatments were defined as physician-prescribed treatments that were additional to continued use of the parent study orthosis and/or stretches after the parent study intervention ended. J Hand Surg Am.
Participants Participants for the parent study were recruited at the University of Pittsburgh, School of Health and Rehabilitation Sciences, and Alleghany General Hospital, Human Motion Rehabilitation. The inclusion criteria for the parent study were individuals with ages 18 years and older with clinical symptoms of CTS (eg, nighttime numbness or tingling and numbness when holding a book), a positive Phalen maneuver or Tinel sign, no thenar atrophy, and 2-point discrimination 5 mm or less. Participants were excluded if they had already received a recommendation for CTS surgery, were pregnant, demonstrated compressive neuropathy in their ipsilateral arm or peripheral polyneuropathy, had diabetes, had a previous carpal tunnel release, were noneEnglish speaking, or would not likely be compliant with a home therapeutic regimen (eg, owing to memory loss or other factor). Because we were interested in indicators associated with progression to CTS surgery, the participants included in the present r
Vol. -, - 2014
3
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
analysis were a convenience sample from the parent study for whom the baseline, 3-month, and 6-month Carpal Tunnel Questionnaire (CTQ) scores were available and the posttreatment surveys from the 3-month and/or 6-month assessments were complete.
TABLE 1. Comparison of the Number of Additional Conservative Treatments Received in Addition to the Parent Study Intervention in Regard to Surgery for CTS*
Outcome assessments Carpal tunnel questionnaire: The CTQ is a self-report questionnaire comprising 2 subscales. The 11-item Symptom Severity Score (SSS) assesses symptoms such as pain, numbness, and tingling. Responses are recorded on a 5-point Likert scale, ranging from 1 (no symptoms) to 5 (most severe pain). The 8-item Functional Status Scale (FSS) measures daily activities that may be affected by hand and wrist symptoms (eg, writing, buttoning, opening a jar), and responses are also recorded on a 5-point Likert scale, ranging from 1 (no difficulty) to 5 (cannot do at all owing to hand or wrist symptoms). The scores for each scale are the averages of the scale items. Higher scores indicate greater symptom severity and disability. Each scale has excellent test-retest reliability and internal consistency. The validity of each scale ranged from weak to fair and demonstrated responsiveness to change.19 The CTQ was administered in the parent study at the baseline, 4-week (follow-up), 3-month, and 6-month assessments.
Did Not Have Surgery for CTS (n ¼ 75)
4
3
Splint
5
10
Medication
3
6
Exercise
5
8
Ultrasound
1
0
Type of additional treatment Injection
Activity modification
3
1
Ergonomics
1
0
Patient education
3
5
0
4
61
1
9
5
2
4
4
3
4
5
16
69
Cumulative number of additional treatments
Continued parent study intervention
Posttreatment survey: Two posttreatment surveys were developed for the parent study, one for each of the 3-month and 6-month assessments. Each survey had 9 questions that referred to the time after the 4-week parent study intervention ended: (1) frequency of CTS symptoms; (2) symptom level; (3) whether current symptoms were an improvement over those at the beginning of the study; (4) additional conservative treatments received to manage CTS symptoms (yes/no); (5) if applicable, to indicate each additional treatment received (Table 1); (6) whether surgery for CTS was received or planned; (7) if applicable, date of surgery or planned surgery; (8) continued use of the study orthosis (yes/no); and (9) continued use of the study stretches (yes/no).
*Data are given as frequency.
hand with CTS (right, left, bilateral), and symptom duration. In addition, information in regard to employment status and cause of CTS were collected. The specific posttreatment survey questions of interest for the present analysis were whether participants received additional conservative treatments, continued the parent study intervention, and had surgery for CTS. To verify whether or not patients received surgery, a representative from the doctors’ offices reviewed the medical records of those participants who returned the posttreatment surveys. Because of the relative sample size and no significant difference in progression to surgery between the 4 randomized intervention groups of the parent study, the participants for the present analysis were treated as a single group.
Procedure The parent study was approved by the University of Pittsburgh Institutional Review Board, and participant consent was obtained prior to assessment. We reviewed the dataset from the parent study and identified participants eligible for the present analysis. The following characteristics were collected from the demographic questionnaire completed by participants: age, sex, ethnicity (Hispanic or Latino, not Hispanic or Latino), race (white, African American, other), hand dominance, J Hand Surg Am.
Had Surgery for CTS (n ¼ 21)
Statistical analysis Descriptive statistics were computed for participant demographics with means and SDs for continuous variables and frequencies (ie, count) and percentages for categorical variables. A univariate analysis was performed to identify which variables were statistically significant and correlated to surgery for CTS using the r
Vol. -, - 2014
4
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
TABLE 2.
Participant Demographics and Baseline Clinical Characteristics Mean SD Frequency (%)
Demographics* Age, mean (SD), y
Total† (n ¼ 96)
Had Surgeryz (n ¼ 21)
Did Not Have Surgeryx (n ¼ 75)
54 (12)
51 (10)
53 (12)
71 (74)
18 (86)
53 (71)
1 (1)
1 (5)
0 (0)
88 (99)
19 (95)
69 (100)
Gender Female Ethnicity Hispanic or Latino Not Hispanic or Latino Race White
87 (93)
16 (80)
71 (96)
African American
5 (5)
4 (20)
1 (1)
Other
2 (2)
0 (0)
2 (3)
Right
87 (91)
20 (95)
67 (89)
Left
9 (9)
1 (5)
8 (11)
41 (43)
8 (38)
33 (44)
Hand dominance
Hand with CTS Right Left
16 (17)
2 (10)
14 (19)
Bilateral
39 (41)
11 (52)
28 (37)
3
13 (14)
1 (6)
12 (16)
> 3 to < 12
27 (30)
6 (33)
21 (29)
12
51 (56)
11 (61)
40 (55)
Full-time
44 (46)
10 (47.5)
Part-time
17 (18)
Not working
35 (36)
Symptom duration, mo
Employment status 1 (5)
34 (45) 16 (21)
10 (47.5)
25 (33)
Cause of CTS Occupation
13 (14)
3 (14)
10 (13)
Other
83 (86)
18 (86)
65 (87)
CTQ SSS, mean (SD)
2.6 (0.8)
3.7 (0.7)
2.5 (0.6)
CTQ FSS, mean (SD)
2.1 (0.9)
3.3 (0.8)
1.9 (0.7)
Clinical characteristics
*All data are given as frequency (%) except where noted. †Ethnicity, n ¼ 89; race, n ¼ 94; symptom duration, n ¼ 91. zEthnicity, n ¼ 20; race, n ¼ 20; symptom duration, n ¼ 18. xEthnicity, n ¼ 69; race, n ¼ 74; symptom duration, n ¼ 73.
Spearman rho (r) correlation coefficient. The variables included in the univariate analysis were CTQ SSS at baseline, 3-month, and 6-month assessments; CTQ FSS scores at baseline, 3-month, and 6-month assessments; age at baseline; additional conservative treatments (yes/ no); continued use of the orthosis and/or completion of the stretches from the study intervention (yes/no); and surgery for CTS (yes/no). Additional conservative J Hand Surg Am.
treatments participants received were not segregated into individual variables for the analysis because the types and combinations of additional conservative treatments prescribed by physicians varied, the information in regard to dosage of additional conservative treatments was not available, and on average, any singular additional conservative treatment was received by fewer than 10 participants. r
Vol. -, - 2014
5
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
TABLE 3. Results of Univariate and Logistic Regression Analyses (Spearman rho) for the Association Between Conservative Treatment and Progression to Carpal Tunnel Release Surgery Univariate Analysis Surgery for CTS Surgery for CTS
CTQ SSS, Baseline
Additional Treatments
Logistical Regression
Continued Study Intervention
Age, Baseline
OR (95% CI) e
1.0
CTQ SSS, baseline
0.5*
1.0
Additional treatments
0.6*
0.3*
12.5 (3.1, 50.7) 1.0
24.3 (4.3, 138.2)
Continued study intervention
0.2*
0.0
0.2
1.0
Age, baseline
0.1
0.3*
0.3*
0.0
0.2 (0.0, 1.1) 1.0
1.1 (1.0, 1.2) Nagelkerke R2 ¼ .64
CI, confidence interval; OR, odds ratio. *P < .05.
There were 2 specific aims for this analysis: to examine the relationship between severity of CTS symptoms and surgery for CTS and to examine the relationship between additional conservative treatments (ie, treatment in addition to the parent study intervention) and surgery for CTS. A backward, stepwise logistic regression analysis was performed to explore the relationship between predictor variables and surgery for CTS. The predictor variables chosen for the regression model were based on the univariate analysis, excluding those variables with shared variance. All tests of statistical significance were 2-sided, and the alpha equal to .05. The assumptions of the data were tested to determine the stability of the logistic regression model once the predictor variables were determined. There were no outliers in the data, and variance inflation factors indicated no multicollinearity (predictor variables 1.18); all other assumptions were met. A post hoc power analysis indicated that we had 98% power to detect associations, with an alpha of .05 and sample size of 96.
6-month assessment. The CTQ SSS and FSS scores were, on average, higher for participants who had surgery than participants who did not have surgery. Thirty-one participants (32%) received additional conservative treatments (ie, treatment received after the 4-wk parent study intervention additional to continued use of the parent study orthosis and/or stretches). Sixteen (76%) of the 21 participants who had surgery continued the parent study intervention as needed after the 4 week period, and 69 (92%) of the 75 participants who did not have surgery continued the parent study intervention as needed. Seventeen participants received at least 1 additional conservative treatment, continued the study intervention after the 4 week period, and also had surgery (Table 1). Fourteen participants received additional conservative treatments and did not have surgery. Table 3 presents the results of the univariate analysis. Baseline CTQ SSS, additional conservative treatments, and whether participants continued the parent study intervention were included in the final logistical regression model. Although statistically significant and correlated to surgery for CTS, CTQ SSS at 3-month and CTQ FSS scores at baseline assessments were not included in the logistical regression model owing to their shared variance with baseline CTQ SSS (Spearman rho ¼ .45, P < .001; and Spearman rho ¼ .66, P < .001, respectively). Age had minimal correlation to surgery for CTS (Spearman rho ¼ .07) and was not statistically significant (P ¼ .48); however, given its confounding relationship to disability, it was included in the regression model. The overall goodness-of-fit of the model between observed and predicted cases was poor, Hosmer and Lemeshow test chi-square (8) ¼ 70.7, P < .001. The
RESULTS A total of 96 participants (77% of those enrolled in the parent study) were included in the present analysis. Participants were predominantly female and white, and the average age was 54 years (Table 2). The majority of participants were right handed (with either right or bilateral CTS. More than half the participants experienced CTS symptoms for more than 12 months at the start of the study. The average baseline CTQ SSS was 2.6 and the FSS score was 2.1. Twenty-one participants (22%) received surgery for CTS between the start of the parent study and the J Hand Surg Am.
r
Vol. -, - 2014
6
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
model predictors overall were statistically significant in distinguishing between whether or not individuals had surgery for CTS, chi-square (4) ¼ 52, P < .001, Nagelkerke R2 ¼ .64. The results of the logistic regression analysis indicated that both greater severity of baseline CTS symptoms and additional conservative treatments were statistically significant indicators of participants who received surgery for CTS. (Table 3). Although not statistically significant, participants who continued the study intervention were less likely to receive surgery. Age was not a strong indicator of surgery (Table 3).
whose study looked only at immobilization. A distinctive feature of the parent study intervention was the addition of stretching to loosen the muscles of the forearm and hand, which has been shown to decrease carpal tunnel pressure23 and increase blood supply to the nerve.24 The use of an orthosis in combination with lumbrical stretches was an effective intervention that positively affected function for up to 6 months, even after symptom severity plateaued. Future research should consider for whom and under what circumstances the parent study intervention is beneficial. We recognize different types of interventions for CTS have been studied and found to have varying levels of effectiveness. Guidelines are inconclusive to which treatments are most effective for patients based on clinical characteristics.7 Although our analyses suggest that a single course of conservative care can be effective and that multiple conservative treatments are not additive, unanswered questions remain. We need large, population-based studies to identify under what circumstances and who is best suited for conservative care versus who is best suited for surgery. Conservative care, such as corticosteroid injections, lumbrical stretches and immobilization, and ultrasound, need to be evaluated both singly and in combination to determine their overall short-term and long-term effectiveness in regard to progression to surgery for CTS. In addition, the optimal dosage and timing of interventions must be explored to optimize treatment to reduce both disability and costs. Current evidence-based guidelines do not characterize the association between conservative care and surgery for CTS.7 Clinicians lack evidence as to whether one type of treatment or whether combinations of treatment are more or less effective. Clinical guidelines do not provide parameters for what is an effective treatment dosage or length of treatment before adding more or changing the treatment. In addition, clinicians do not have evidence-based guidance as to whether there are differences in symptom severity or function based on the order in which types of treatment are received. The aim of conservative care to manage CTS is to eliminate symptoms and improve function, thereby preventing progression to surgery. Yet, individuals who progress to surgery often first receive conservative treatment. The results of the present analysis suggest that at least 1 course of conservative treatment should be tried to manage CTS symptoms for people who are not advised to have surgery. However, those who do not respond to 1 course of conservative treatment may not respond to additional treatments, and surgery may be the most appropriate care.
DISCUSSION Overall, our data suggested that people with CTS who received surgery had higher baseline symptoms and were likely to have received combinations of multiple conservative treatments (eg, injection) to address those symptoms. This is similar to the results of Boyd et al,15 who reported that people with higher baseline CTS symptoms were more likely to have surgery. Because people frequently choose surgery with the expectation that it would alleviate symptoms,20 these results are logical. In this analysis, additional conservative treatments completed after the 4 week study period were also indicators of progression to surgery for CTS. Current CTS guidelines recommend at least 2 trials of conservative treatment prior to considering surgery.7 Our results suggest that, for individuals who do not respond to one course of conservative treatment, additional conservative treatments may not be the most efficient option to improve symptoms, leading to a decision to try surgery. We cannot infer, however, a causal relationship between the effectiveness of conservative treatments and surgery. The parent study was a comparative effectiveness design for an orthosis/stretch combination treatment. The present analysis is not intended to comment on the effectiveness of conservative care for CTS. There are a variety of reasons why patients or physicians may choose conservative treatment or surgery, including age, severity of symptoms, function loss, patient perception of the efficacy of the surgery, the presence of workers’ compensation insurance, patient education level, and the presence of comorbidities.20e22 Future research should identify characteristics of subgroups who do not respond to conservative treatment and for whom surgery may be the most effective option. Participants who continued the parent study intervention were less likely to receive surgery for up to 6 months. The incidence of surgery in the parent study was less than half the reported 57% by Boyd et al,15 J Hand Surg Am.
r
Vol. -, - 2014
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
Limitations Our conclusions are cautionary, given we report a secondary analysis of data. The parent study collected data up to 6 months to examine long-term effects of the orthosis/stretch combinations, a time frame supported by evidence that suggested effective treatments typically have a measurable effect within 2 to 7 weeks.7 It is possible that some participants received surgery after 6 months. The parent study did not include follow-up for postsurgical outcomes; therefore, we cannot comment on this aspect of the continuum of care for CTS. In addition, data were not available to examine the time from diagnosis of CTS to surgery. Although individuals who received a recommendation for surgery for CTS were excluded from the parent study, data were not available for whether participants received conservative treatment prior to the parent study. We did not obtain information about preferences or other factors that might affect progression to surgery. Our small sample and overall model fit to the data resulted in a relatively unstable model. Our sample may not have been representative of the overall population of individuals with CTS because participants were selected from a previous study in which the primary referral source was hand surgeons and because we included only those who returned complete assessment forms. Of final note, although the odds ratios for CTS symptoms and additional conservative treatments were impressive, they were anchored with wide confidence intervals that suggest a large degree of variance within the data.
7.
8.
9.
10.
11.
12. 13.
14.
15.
16.
17.
18.
REFERENCES 19.
1. Lewis C, Mauffrey C, Newman S, Lambert A, Hull P. Current concepts in carpal tunnel syndrome: a review of the literature. Eur J Orthop Surg Traumatol. 2010;20(6):445e452. 2. Lawrence RC, Helmick CG, Arnett FC, et al. Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States. Arthritis Rheum. 2008;41(5):778e799. 3. Nuckols T, Harber P, Sandin K, et al. Quality measures for the diagnosis and non-operative management of carpal tunnel syndrome in occupational settings. J Occup Rehabil. 2011;21(1):100e119. 4. Foley M, Silverstein B, Polissar N. The economic burden of carpal tunnel syndrome: long-term earnings of CTS claimants in Washington State. Am J Ind Med. 2007;50(3):155e172. 5. Palmer DH, Hanrahan LP. Social and economic costs of carpal tunnel surgery. Instr Course Lect. 1995;44:167e172. 6. Bureau of Labor Statistics. Table 5. Number, percent distribution, and median days away from work for nonfatal occupational injuries and illnesses involving days away from work by selected worker and case characteristics and selected nature of injury or illness, 2011.
J Hand Surg Am.
20.
21.
22.
23.
24.
r
7
http://www.bls.gov/news.release/pdf/osh2.pdf. 2012. Accessed September 16, 2013. American Academy of Orthopedic Surgeons. Clinical Practice Guidelines on the Treatment of Carpal Tunnel Syndrome. Rosemont, IL: American Academy of Orthopedic Surgeons; 2008. Marshall SC, Gaetan T, Ashworth NL. Local corticosteroid injection for carpal tunnel syndrome. Cochrane Database Syst Rev. 2006;2: CD001554. Page MJ, Massy-Westropp N, O’Connor D, Pitt V. Splinting for carpal tunnel syndrome. Cochrane Database Syst Rev. 2012;7: CD010003. Page MJ, O’Connor D, Pitt V, Massy-Westropp N. Therapeutic ultrasound for carpal tunnel syndrome. Cochrane Database Syst Rev. 2012;1:CD009601. Huisstede BM, Hoogvliet P, Randsdorp MS, Glerum S, van Middelkoop M, Koes BW. Carpal tunnel syndrome. Part I: effectiveness of nonsurgical treatments—A systematic review. Arch Phys Med Rehabil. 2010;91(7):981e1004. Ashworth NL. Carpal tunnel syndrome. Clin Evid Online. 2011: 2011. O’Connor D, Marshall S, Massy-Westropp N. Non-surgical treatment (other than steroid injection) for carpal tunnel syndrome. Cochrane Database Syst Rev. 2009;1:CD003219. Muller M, Tsui D, Schnurr R, Biddulph-Deisroth L, Hard J, MacDermid JC. Effectiveness of hand therapy interventions in the primary management of carpal tunnel syndrome: a systemctic review. J Hand Ther. 2004;17(2):210e228. Boyd KU, Gan BS, Ross DC, Richards RS, Roth JH, MacDermid JC. Outcomes in carpal tunnel syndrome: symptom severity, conservative management and progression to surgery. Clin Invest Med. 2005;28(5): 254e260. Pomerance J, Zurakowski D, Fine I. The cost-effectiveness of nonsurgical versus surgical treatment for carpal tunnel syndrome. J Hand Surg Am. 2009;34(7):1193e1200. Hall B, Lee HC, Fitzgerald H, Byrne B, Barton A, Lee AH. Investigating the effectiveness of full-time wrist splinting and education in the treatment of carpal tunnel syndrome: a randomized controlled trial. Am J Occup Ther. 2013;67(4):448e459. Baker NA, Moehling K, Rubinstein E, Wollstein R, Gustafson NP, Baratz M. The comparative effectiveness of combined lumbrical muscle splints and stretches on symptoms and function in carpal tunnel syndrome. Arch Phys Med Rehabil. 2012;93(1):1e10. Levine DW, Simmons BP, Koris MJ, et al. A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg Am. 1993;75(11):1585e1592. Bessette L, Keller RB, Liang MH, Simmons BP, Fossel AH, Katz JN. Patients’ preferences and their relationship with satisfaction following carpal tunnel release. J Hand Surg Am. 1997;22(4):613e620. Jerosch-Herold C, Mason R, Chojnowski AJ. A qualitative study of the experiences and expectations of surgery in patients with carpal tunnel syndrome. J Hand Ther. 2008;21(1):54e62. Shifflett GD, Dy CJ, Daluiski A. Carpal tunnel surgery: patient preferences and predictors for satisfaction. Patient Prefer Adherence. 2012;6:685e689. Seradge H, Jia YC, Owens W. In vivo measurement of carpal tunnel pressure in the functioning hand. J Hand Surg Am. 1995;20(5): 855e859. Butler D. Mobilization of the Nervous System. Melbourne: Churchill Livingstone; 1991.
Vol. -, - 2014
Symptom Severity and Conservative Treatment for Carpal Tunnel Syndrome in Association With Eventual Carpal Tunnel Release Nancy A. Baker, MPH, Heather M. Livengood, MS
Purpose To study the relationship between the severity of carpal tunnel syndrome (CTS) symptoms and surgery for CTS and the relationship between conservative treatments and surgery for CTS. Methods A secondary analysis of baseline to 6-month data from a randomized controlled trial, which examined the effectiveness of orthosis/stretch combinations on the symptoms of CTS, was conducted for a total of 96 participants with CTS. Participants completed the Carpal Tunnel Questionnaire and posttreatment surveys. Statistical analyses included exploration of correlates of progression to surgery for CTS and logistical regression to examine the association between conservative treatments and CTS symptoms and progression to surgery for CTS. Results Twenty-one participants received surgery for their CTS, and 31 participants received 1 or more conservative treatments. Severity of baseline CTS symptoms and additional treatments were indicators of progression to surgery. The randomized controlled trial intervention was inversely associated with progression to surgery. Conclusions CTS that does not respond to an initial course of conservative treatment may not improve with additional treatments. More than half of the participants who received additional conservative treatment still progressed to surgery. Current intervention guidelines for CTS provide limited guidance as to the best methods to efficiently treat CTS. Clinical relevance CTS is a costly and high-burden disorder, resulting in reduced quality of life. Research should examine when and for whom conservative care is an effective choice and the association between conservative care and the eventual need for CTS surgery. (J Hand Surg Am. 2014;-:-e-. Copyright Ó 2014 by the American Society for Surgery of the Hand. All rights reserved.) Key words Carpal tunnel syndrome, rehabilitation, treatment, carpal tunnel release surgery.
C
(CTS) is the most common upper extremity neuropathy1 and repeated trauma work injury, affecting 10 million Americans annually.2 CTS is a high-burden disorder that reduces quality of life and costs billions of health ARPAL TUNNEL SYNDROME
care dollars.3e5 People with CTS experience symptoms and functional losses that affect their abilities to perform ordinary activities. In 2011, workers with CTS had a median 28 days away from work, which exceeded those for fractures, multiple injuries, and amputations.6
From the Department of Occupational Therapy, University of Pittsburgh, School of Health and Rehabilitation Sciences, Pittsburgh, PA.
No benefits in any form have been received or will be received related directly or indirectly to the subject of this article.
Received for publication January 15, 2014; accepted in revised form April 15, 2014.
Corresponding author: Heather M. Livengood, MS, 5012 Forbes Tower, Department of Occupational Therapy, University of Pittsburgh, Pittsburgh, PA 15260; e-mail: [email protected].
The authors acknowledge the support of the Arthritis Foundation: Eastern Pennsylvania Chapter for the grant that funded the parent study.
0363-5023/14/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.04.034
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1
2
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
METHODS Parent study The parent study examined the comparative effectiveness of orthosis/stretch combinations on CTS symptoms and function. Refer to Baker et al18 for the full study protocol. Briefly, participants were screened for and recruited primarily by 2 hand and upper extremity surgeons based on best practice for diagnosing CTS. Participants were randomized to 1 of 4 intervention groups that compared the effect of 4 possible combinations of types of orthosis (lumbrical orthosis [0 wrist extension, 0 e10 metacarpophalangeal {MCP} flexion] vs neutral wrist orthosis [0 wrist extension]) and stretches (lumbrical stretches versus general stretches). After randomization, an occupational therapist explained CTS, either fabricated a lumbrical orthosis or fitted a neutral wrist orthosis, and trained the participant in either lumbrical or general stretches. The parent study intervention was a 4-week home program during which time participants were instructed to wear their orthosis at night and to perform their stretches 6 times daily. Participants completed a daily log to track adherence to the study protocol. During the 4-week intervention, participants received no other treatment for CTS. After the 4-weeek home program, participants were instructed to continue to wear the orthosis and complete the stretches as needed. They received additional conservative treatment at the discretion of their physician as part of usual CTS care. Follow-up assessments were conducted at 3 and 6 months to track carryover effects of the parent study intervention.
Workers with CTS experienced wage loss during and after treatment, a cumulative loss of earnings of between $45,000 and $89,000 6 years after treatment.4 Current guidelines for CTS intervention provide limited guidance on the most efficient and best type of treatment.7 These guidelines suggest 1 or more courses of conservative treatment to reduce symptoms. Evidence suggests effective treatments typically have a measureable effect on symptoms within 2 to 7 weeks.7 Surgery is an option if conservative care is not successful. Conservative care is recommended to alleviate CTS, yet there is little guidance as to the best type of conservative treatment. Over a dozen treatments for CTS have been investigated.7e14 Several, such as corticosteroid injections and immobilization, are supported by moderate evidence. However, few studies have examined the association between conservative care and surgery. Boyd et al15 tracked 47 hands (25 patients) after they received 12 weeks of immobilization. Patients with 27 affected hands progressed to surgery within 6 months of treatment. Those who progressed to surgery reported higher symptoms and more impaired function at baseline and minimal improvement during treatment. Pomerance et al16 examined the cost effectiveness of surgical versus conservative care. Of the 60 patients who chose to receive 2 weeks of conservative treatment, 32 elected to have surgery during the following 12 months. Hall et al17 reported that, after an 8-week program of immobilization and education, 37% of their sample planned to receive surgery, and those patients had greater symptoms severity, functional deficits, pain, and longer symptom duration. These studies indicate that many patients receive surgery after conservative care but do not identify if more than 1 course of conservative treatment prevents progression to surgery. Hall et al17 closely examined risk factors for progression to surgery. This report is a secondary analysis to examine the relationship between indicators associated with progression to surgery up to 6 months following conservative treatment. The data were collected as part of a randomized controlled trial that examined the effectiveness of an orthosis/stretch combination for individuals with CTS.18 The incidence of surgery in the parent study was 26%. Two primary indicators were examined: the relationship between severity of CTS symptoms and surgery for CTS and the relationship between additional conservative treatments and surgery for CTS. Additional conservative treatments were defined as physician-prescribed treatments that were additional to continued use of the parent study orthosis and/or stretches after the parent study intervention ended. J Hand Surg Am.
Participants Participants for the parent study were recruited at the University of Pittsburgh, School of Health and Rehabilitation Sciences, and Alleghany General Hospital, Human Motion Rehabilitation. The inclusion criteria for the parent study were individuals with ages 18 years and older with clinical symptoms of CTS (eg, nighttime numbness or tingling and numbness when holding a book), a positive Phalen maneuver or Tinel sign, no thenar atrophy, and 2-point discrimination 5 mm or less. Participants were excluded if they had already received a recommendation for CTS surgery, were pregnant, demonstrated compressive neuropathy in their ipsilateral arm or peripheral polyneuropathy, had diabetes, had a previous carpal tunnel release, were noneEnglish speaking, or would not likely be compliant with a home therapeutic regimen (eg, owing to memory loss or other factor). Because we were interested in indicators associated with progression to CTS surgery, the participants included in the present r
Vol. -, - 2014
3
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
analysis were a convenience sample from the parent study for whom the baseline, 3-month, and 6-month Carpal Tunnel Questionnaire (CTQ) scores were available and the posttreatment surveys from the 3-month and/or 6-month assessments were complete.
TABLE 1. Comparison of the Number of Additional Conservative Treatments Received in Addition to the Parent Study Intervention in Regard to Surgery for CTS*
Outcome assessments Carpal tunnel questionnaire: The CTQ is a self-report questionnaire comprising 2 subscales. The 11-item Symptom Severity Score (SSS) assesses symptoms such as pain, numbness, and tingling. Responses are recorded on a 5-point Likert scale, ranging from 1 (no symptoms) to 5 (most severe pain). The 8-item Functional Status Scale (FSS) measures daily activities that may be affected by hand and wrist symptoms (eg, writing, buttoning, opening a jar), and responses are also recorded on a 5-point Likert scale, ranging from 1 (no difficulty) to 5 (cannot do at all owing to hand or wrist symptoms). The scores for each scale are the averages of the scale items. Higher scores indicate greater symptom severity and disability. Each scale has excellent test-retest reliability and internal consistency. The validity of each scale ranged from weak to fair and demonstrated responsiveness to change.19 The CTQ was administered in the parent study at the baseline, 4-week (follow-up), 3-month, and 6-month assessments.
Did Not Have Surgery for CTS (n ¼ 75)
4
3
Splint
5
10
Medication
3
6
Exercise
5
8
Ultrasound
1
0
Type of additional treatment Injection
Activity modification
3
1
Ergonomics
1
0
Patient education
3
5
0
4
61
1
9
5
2
4
4
3
4
5
16
69
Cumulative number of additional treatments
Continued parent study intervention
Posttreatment survey: Two posttreatment surveys were developed for the parent study, one for each of the 3-month and 6-month assessments. Each survey had 9 questions that referred to the time after the 4-week parent study intervention ended: (1) frequency of CTS symptoms; (2) symptom level; (3) whether current symptoms were an improvement over those at the beginning of the study; (4) additional conservative treatments received to manage CTS symptoms (yes/no); (5) if applicable, to indicate each additional treatment received (Table 1); (6) whether surgery for CTS was received or planned; (7) if applicable, date of surgery or planned surgery; (8) continued use of the study orthosis (yes/no); and (9) continued use of the study stretches (yes/no).
*Data are given as frequency.
hand with CTS (right, left, bilateral), and symptom duration. In addition, information in regard to employment status and cause of CTS were collected. The specific posttreatment survey questions of interest for the present analysis were whether participants received additional conservative treatments, continued the parent study intervention, and had surgery for CTS. To verify whether or not patients received surgery, a representative from the doctors’ offices reviewed the medical records of those participants who returned the posttreatment surveys. Because of the relative sample size and no significant difference in progression to surgery between the 4 randomized intervention groups of the parent study, the participants for the present analysis were treated as a single group.
Procedure The parent study was approved by the University of Pittsburgh Institutional Review Board, and participant consent was obtained prior to assessment. We reviewed the dataset from the parent study and identified participants eligible for the present analysis. The following characteristics were collected from the demographic questionnaire completed by participants: age, sex, ethnicity (Hispanic or Latino, not Hispanic or Latino), race (white, African American, other), hand dominance, J Hand Surg Am.
Had Surgery for CTS (n ¼ 21)
Statistical analysis Descriptive statistics were computed for participant demographics with means and SDs for continuous variables and frequencies (ie, count) and percentages for categorical variables. A univariate analysis was performed to identify which variables were statistically significant and correlated to surgery for CTS using the r
Vol. -, - 2014
4
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
TABLE 2.
Participant Demographics and Baseline Clinical Characteristics Mean SD Frequency (%)
Demographics* Age, mean (SD), y
Total† (n ¼ 96)
Had Surgeryz (n ¼ 21)
Did Not Have Surgeryx (n ¼ 75)
54 (12)
51 (10)
53 (12)
71 (74)
18 (86)
53 (71)
1 (1)
1 (5)
0 (0)
88 (99)
19 (95)
69 (100)
Gender Female Ethnicity Hispanic or Latino Not Hispanic or Latino Race White
87 (93)
16 (80)
71 (96)
African American
5 (5)
4 (20)
1 (1)
Other
2 (2)
0 (0)
2 (3)
Right
87 (91)
20 (95)
67 (89)
Left
9 (9)
1 (5)
8 (11)
41 (43)
8 (38)
33 (44)
Hand dominance
Hand with CTS Right Left
16 (17)
2 (10)
14 (19)
Bilateral
39 (41)
11 (52)
28 (37)
3
13 (14)
1 (6)
12 (16)
> 3 to < 12
27 (30)
6 (33)
21 (29)
12
51 (56)
11 (61)
40 (55)
Full-time
44 (46)
10 (47.5)
Part-time
17 (18)
Not working
35 (36)
Symptom duration, mo
Employment status 1 (5)
34 (45) 16 (21)
10 (47.5)
25 (33)
Cause of CTS Occupation
13 (14)
3 (14)
10 (13)
Other
83 (86)
18 (86)
65 (87)
CTQ SSS, mean (SD)
2.6 (0.8)
3.7 (0.7)
2.5 (0.6)
CTQ FSS, mean (SD)
2.1 (0.9)
3.3 (0.8)
1.9 (0.7)
Clinical characteristics
*All data are given as frequency (%) except where noted. †Ethnicity, n ¼ 89; race, n ¼ 94; symptom duration, n ¼ 91. zEthnicity, n ¼ 20; race, n ¼ 20; symptom duration, n ¼ 18. xEthnicity, n ¼ 69; race, n ¼ 74; symptom duration, n ¼ 73.
Spearman rho (r) correlation coefficient. The variables included in the univariate analysis were CTQ SSS at baseline, 3-month, and 6-month assessments; CTQ FSS scores at baseline, 3-month, and 6-month assessments; age at baseline; additional conservative treatments (yes/ no); continued use of the orthosis and/or completion of the stretches from the study intervention (yes/no); and surgery for CTS (yes/no). Additional conservative J Hand Surg Am.
treatments participants received were not segregated into individual variables for the analysis because the types and combinations of additional conservative treatments prescribed by physicians varied, the information in regard to dosage of additional conservative treatments was not available, and on average, any singular additional conservative treatment was received by fewer than 10 participants. r
Vol. -, - 2014
5
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
TABLE 3. Results of Univariate and Logistic Regression Analyses (Spearman rho) for the Association Between Conservative Treatment and Progression to Carpal Tunnel Release Surgery Univariate Analysis Surgery for CTS Surgery for CTS
CTQ SSS, Baseline
Additional Treatments
Logistical Regression
Continued Study Intervention
Age, Baseline
OR (95% CI) e
1.0
CTQ SSS, baseline
0.5*
1.0
Additional treatments
0.6*
0.3*
12.5 (3.1, 50.7) 1.0
24.3 (4.3, 138.2)
Continued study intervention
0.2*
0.0
0.2
1.0
Age, baseline
0.1
0.3*
0.3*
0.0
0.2 (0.0, 1.1) 1.0
1.1 (1.0, 1.2) Nagelkerke R2 ¼ .64
CI, confidence interval; OR, odds ratio. *P < .05.
There were 2 specific aims for this analysis: to examine the relationship between severity of CTS symptoms and surgery for CTS and to examine the relationship between additional conservative treatments (ie, treatment in addition to the parent study intervention) and surgery for CTS. A backward, stepwise logistic regression analysis was performed to explore the relationship between predictor variables and surgery for CTS. The predictor variables chosen for the regression model were based on the univariate analysis, excluding those variables with shared variance. All tests of statistical significance were 2-sided, and the alpha equal to .05. The assumptions of the data were tested to determine the stability of the logistic regression model once the predictor variables were determined. There were no outliers in the data, and variance inflation factors indicated no multicollinearity (predictor variables 1.18); all other assumptions were met. A post hoc power analysis indicated that we had 98% power to detect associations, with an alpha of .05 and sample size of 96.
6-month assessment. The CTQ SSS and FSS scores were, on average, higher for participants who had surgery than participants who did not have surgery. Thirty-one participants (32%) received additional conservative treatments (ie, treatment received after the 4-wk parent study intervention additional to continued use of the parent study orthosis and/or stretches). Sixteen (76%) of the 21 participants who had surgery continued the parent study intervention as needed after the 4 week period, and 69 (92%) of the 75 participants who did not have surgery continued the parent study intervention as needed. Seventeen participants received at least 1 additional conservative treatment, continued the study intervention after the 4 week period, and also had surgery (Table 1). Fourteen participants received additional conservative treatments and did not have surgery. Table 3 presents the results of the univariate analysis. Baseline CTQ SSS, additional conservative treatments, and whether participants continued the parent study intervention were included in the final logistical regression model. Although statistically significant and correlated to surgery for CTS, CTQ SSS at 3-month and CTQ FSS scores at baseline assessments were not included in the logistical regression model owing to their shared variance with baseline CTQ SSS (Spearman rho ¼ .45, P < .001; and Spearman rho ¼ .66, P < .001, respectively). Age had minimal correlation to surgery for CTS (Spearman rho ¼ .07) and was not statistically significant (P ¼ .48); however, given its confounding relationship to disability, it was included in the regression model. The overall goodness-of-fit of the model between observed and predicted cases was poor, Hosmer and Lemeshow test chi-square (8) ¼ 70.7, P < .001. The
RESULTS A total of 96 participants (77% of those enrolled in the parent study) were included in the present analysis. Participants were predominantly female and white, and the average age was 54 years (Table 2). The majority of participants were right handed (with either right or bilateral CTS. More than half the participants experienced CTS symptoms for more than 12 months at the start of the study. The average baseline CTQ SSS was 2.6 and the FSS score was 2.1. Twenty-one participants (22%) received surgery for CTS between the start of the parent study and the J Hand Surg Am.
r
Vol. -, - 2014
6
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
model predictors overall were statistically significant in distinguishing between whether or not individuals had surgery for CTS, chi-square (4) ¼ 52, P < .001, Nagelkerke R2 ¼ .64. The results of the logistic regression analysis indicated that both greater severity of baseline CTS symptoms and additional conservative treatments were statistically significant indicators of participants who received surgery for CTS. (Table 3). Although not statistically significant, participants who continued the study intervention were less likely to receive surgery. Age was not a strong indicator of surgery (Table 3).
whose study looked only at immobilization. A distinctive feature of the parent study intervention was the addition of stretching to loosen the muscles of the forearm and hand, which has been shown to decrease carpal tunnel pressure23 and increase blood supply to the nerve.24 The use of an orthosis in combination with lumbrical stretches was an effective intervention that positively affected function for up to 6 months, even after symptom severity plateaued. Future research should consider for whom and under what circumstances the parent study intervention is beneficial. We recognize different types of interventions for CTS have been studied and found to have varying levels of effectiveness. Guidelines are inconclusive to which treatments are most effective for patients based on clinical characteristics.7 Although our analyses suggest that a single course of conservative care can be effective and that multiple conservative treatments are not additive, unanswered questions remain. We need large, population-based studies to identify under what circumstances and who is best suited for conservative care versus who is best suited for surgery. Conservative care, such as corticosteroid injections, lumbrical stretches and immobilization, and ultrasound, need to be evaluated both singly and in combination to determine their overall short-term and long-term effectiveness in regard to progression to surgery for CTS. In addition, the optimal dosage and timing of interventions must be explored to optimize treatment to reduce both disability and costs. Current evidence-based guidelines do not characterize the association between conservative care and surgery for CTS.7 Clinicians lack evidence as to whether one type of treatment or whether combinations of treatment are more or less effective. Clinical guidelines do not provide parameters for what is an effective treatment dosage or length of treatment before adding more or changing the treatment. In addition, clinicians do not have evidence-based guidance as to whether there are differences in symptom severity or function based on the order in which types of treatment are received. The aim of conservative care to manage CTS is to eliminate symptoms and improve function, thereby preventing progression to surgery. Yet, individuals who progress to surgery often first receive conservative treatment. The results of the present analysis suggest that at least 1 course of conservative treatment should be tried to manage CTS symptoms for people who are not advised to have surgery. However, those who do not respond to 1 course of conservative treatment may not respond to additional treatments, and surgery may be the most appropriate care.
DISCUSSION Overall, our data suggested that people with CTS who received surgery had higher baseline symptoms and were likely to have received combinations of multiple conservative treatments (eg, injection) to address those symptoms. This is similar to the results of Boyd et al,15 who reported that people with higher baseline CTS symptoms were more likely to have surgery. Because people frequently choose surgery with the expectation that it would alleviate symptoms,20 these results are logical. In this analysis, additional conservative treatments completed after the 4 week study period were also indicators of progression to surgery for CTS. Current CTS guidelines recommend at least 2 trials of conservative treatment prior to considering surgery.7 Our results suggest that, for individuals who do not respond to one course of conservative treatment, additional conservative treatments may not be the most efficient option to improve symptoms, leading to a decision to try surgery. We cannot infer, however, a causal relationship between the effectiveness of conservative treatments and surgery. The parent study was a comparative effectiveness design for an orthosis/stretch combination treatment. The present analysis is not intended to comment on the effectiveness of conservative care for CTS. There are a variety of reasons why patients or physicians may choose conservative treatment or surgery, including age, severity of symptoms, function loss, patient perception of the efficacy of the surgery, the presence of workers’ compensation insurance, patient education level, and the presence of comorbidities.20e22 Future research should identify characteristics of subgroups who do not respond to conservative treatment and for whom surgery may be the most effective option. Participants who continued the parent study intervention were less likely to receive surgery for up to 6 months. The incidence of surgery in the parent study was less than half the reported 57% by Boyd et al,15 J Hand Surg Am.
r
Vol. -, - 2014
CTS SYMPTOMS AND TREATMENT IN ASSOCIATION WITH SURGERY
Limitations Our conclusions are cautionary, given we report a secondary analysis of data. The parent study collected data up to 6 months to examine long-term effects of the orthosis/stretch combinations, a time frame supported by evidence that suggested effective treatments typically have a measurable effect within 2 to 7 weeks.7 It is possible that some participants received surgery after 6 months. The parent study did not include follow-up for postsurgical outcomes; therefore, we cannot comment on this aspect of the continuum of care for CTS. In addition, data were not available to examine the time from diagnosis of CTS to surgery. Although individuals who received a recommendation for surgery for CTS were excluded from the parent study, data were not available for whether participants received conservative treatment prior to the parent study. We did not obtain information about preferences or other factors that might affect progression to surgery. Our small sample and overall model fit to the data resulted in a relatively unstable model. Our sample may not have been representative of the overall population of individuals with CTS because participants were selected from a previous study in which the primary referral source was hand surgeons and because we included only those who returned complete assessment forms. Of final note, although the odds ratios for CTS symptoms and additional conservative treatments were impressive, they were anchored with wide confidence intervals that suggest a large degree of variance within the data.
7.
8.
9.
10.
11.
12. 13.
14.
15.
16.
17.
18.
REFERENCES 19.
1. Lewis C, Mauffrey C, Newman S, Lambert A, Hull P. Current concepts in carpal tunnel syndrome: a review of the literature. Eur J Orthop Surg Traumatol. 2010;20(6):445e452. 2. Lawrence RC, Helmick CG, Arnett FC, et al. Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States. Arthritis Rheum. 2008;41(5):778e799. 3. Nuckols T, Harber P, Sandin K, et al. Quality measures for the diagnosis and non-operative management of carpal tunnel syndrome in occupational settings. J Occup Rehabil. 2011;21(1):100e119. 4. Foley M, Silverstein B, Polissar N. The economic burden of carpal tunnel syndrome: long-term earnings of CTS claimants in Washington State. Am J Ind Med. 2007;50(3):155e172. 5. Palmer DH, Hanrahan LP. Social and economic costs of carpal tunnel surgery. Instr Course Lect. 1995;44:167e172. 6. Bureau of Labor Statistics. Table 5. Number, percent distribution, and median days away from work for nonfatal occupational injuries and illnesses involving days away from work by selected worker and case characteristics and selected nature of injury or illness, 2011.
J Hand Surg Am.
20.
21.
22.
23.
24.
r
7
http://www.bls.gov/news.release/pdf/osh2.pdf. 2012. Accessed September 16, 2013. American Academy of Orthopedic Surgeons. Clinical Practice Guidelines on the Treatment of Carpal Tunnel Syndrome. Rosemont, IL: American Academy of Orthopedic Surgeons; 2008. Marshall SC, Gaetan T, Ashworth NL. Local corticosteroid injection for carpal tunnel syndrome. Cochrane Database Syst Rev. 2006;2: CD001554. Page MJ, Massy-Westropp N, O’Connor D, Pitt V. Splinting for carpal tunnel syndrome. Cochrane Database Syst Rev. 2012;7: CD010003. Page MJ, O’Connor D, Pitt V, Massy-Westropp N. Therapeutic ultrasound for carpal tunnel syndrome. Cochrane Database Syst Rev. 2012;1:CD009601. Huisstede BM, Hoogvliet P, Randsdorp MS, Glerum S, van Middelkoop M, Koes BW. Carpal tunnel syndrome. Part I: effectiveness of nonsurgical treatments—A systematic review. Arch Phys Med Rehabil. 2010;91(7):981e1004. Ashworth NL. Carpal tunnel syndrome. Clin Evid Online. 2011: 2011. O’Connor D, Marshall S, Massy-Westropp N. Non-surgical treatment (other than steroid injection) for carpal tunnel syndrome. Cochrane Database Syst Rev. 2009;1:CD003219. Muller M, Tsui D, Schnurr R, Biddulph-Deisroth L, Hard J, MacDermid JC. Effectiveness of hand therapy interventions in the primary management of carpal tunnel syndrome: a systemctic review. J Hand Ther. 2004;17(2):210e228. Boyd KU, Gan BS, Ross DC, Richards RS, Roth JH, MacDermid JC. Outcomes in carpal tunnel syndrome: symptom severity, conservative management and progression to surgery. Clin Invest Med. 2005;28(5): 254e260. Pomerance J, Zurakowski D, Fine I. The cost-effectiveness of nonsurgical versus surgical treatment for carpal tunnel syndrome. J Hand Surg Am. 2009;34(7):1193e1200. Hall B, Lee HC, Fitzgerald H, Byrne B, Barton A, Lee AH. Investigating the effectiveness of full-time wrist splinting and education in the treatment of carpal tunnel syndrome: a randomized controlled trial. Am J Occup Ther. 2013;67(4):448e459. Baker NA, Moehling K, Rubinstein E, Wollstein R, Gustafson NP, Baratz M. The comparative effectiveness of combined lumbrical muscle splints and stretches on symptoms and function in carpal tunnel syndrome. Arch Phys Med Rehabil. 2012;93(1):1e10. Levine DW, Simmons BP, Koris MJ, et al. A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg Am. 1993;75(11):1585e1592. Bessette L, Keller RB, Liang MH, Simmons BP, Fossel AH, Katz JN. Patients’ preferences and their relationship with satisfaction following carpal tunnel release. J Hand Surg Am. 1997;22(4):613e620. Jerosch-Herold C, Mason R, Chojnowski AJ. A qualitative study of the experiences and expectations of surgery in patients with carpal tunnel syndrome. J Hand Ther. 2008;21(1):54e62. Shifflett GD, Dy CJ, Daluiski A. Carpal tunnel surgery: patient preferences and predictors for satisfaction. Patient Prefer Adherence. 2012;6:685e689. Seradge H, Jia YC, Owens W. In vivo measurement of carpal tunnel pressure in the functioning hand. J Hand Surg Am. 1995;20(5): 855e859. Butler D. Mobilization of the Nervous System. Melbourne: Churchill Livingstone; 1991.
Vol. -, - 2014
