SCIENTIFIC/CLINICAL ARTICLE JHT READ FOR CREDIT ARTICLE #213.

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1 SCIENTIFIC/CLINICAL ARTICLE JHT READ FOR CREDIT ARTICLE #213. The Long-term Relationship between Duration of Treatment and Contracture Resolution Using Dynamic Orthotic Devices for the Stiff Proximal Interphalangeal Joint: A Prospective Cohort Study Celeste Glasgow, PhD Candidate, B OccThy (Hons) Hand and Upper Limb Rehabilitation Unit, EKCO Occupational Services, Brisbane, Queensland, Australia Jenny Fleming, PhD, B OccThy (Hons) The University of Queensland, School of Health and Rehabilitation Sciences, St Lucia, Queensland, Australia Leigh R. Tooth, PhD, B OccThy (Hons) Richard L. Hockey, BSc, DipAgrSc The University of Queensland, School of Population Health, Lifespan Health Research Unit, Herston, Queensland, Australia ABSTRACT: Study Design: Descriptive design with a prospective cohort. Introduction: Little is known about the long-term relationship between the duration of treatment using dynamic orthoses (splints), and contracture resolution in the stiff proximal interphalangeal (PIP) joint. Purpose of the Study: To examine the long-term relationship between weeks of treatment using dynamic orthoses and contracture resolution, in both flexion and extension deficits of the PIP joint. Methods: Forty-one participants were treated with a dynamic orthotic device (splint) for either a flexion or extension deficit of the PIP joint (n ¼ 48 joints). The relationship between contracture resolution and weeks of treatment was examined controlling for baseline range of motion (ROM), weekly total end range time, pretreatment joint stiffness, time since injury, and diagnosis. Outcome was measured via change in torque and active ROM. Results: Outcome with orthotic use was significantly associated with the weeks of treatment (p, 0.001). ROM increased in a linear fashion although faster progress was observed when treatment was aimed at improving flexion rather than extension. Flexion deficits appeared to maximize gains with orthotic treatment after 12 weeks. However, extension deficits continued to demonstrate slow and continuous improvement beyond the 17 weeks of recorded data. Less treatment duration (in weeks) was needed to restore flexion than extension. Conclusions: The duration of orthotic use (weeks of treatment) is significantly associated with the extent of contracture resolution. Slower recovery of ROM and a longer duration of orthotic use may be expected when the treatment goal is to improve extension rather than flexion. Level of Evidence: 2b. J HAND THER. 2012;25: Hand therapists commonly use dynamic orthoses (splints) to restore passive range of motion (PROM) to a stiff joint when a contracture is present. 1e6 This article was adapted from a presentation to the Australian Hand Therapy Association national conference in October Correspondence and reprint requests to Celeste Glasgow, OT, PhD Candidate, Hand and Upper Limb Rehabilitation Unit, EKCO Occupational Services, GPO Box 309, Brisbane, Queensland 4000, Australia; <celesteg@tpg.com.au> /$ - see front matter Ó 2012 Hanley & Belfus, an imprint of Elsevier Inc. All rights reserved. doi: /j.jht Dynamic orthoses provide a mechanism for holding the stiff joint at the end of available range of motion (ROM) under light tension for prolonged periods of time. This low load prolonged stretch, 7 provides the stimulus needed for collagen growth and reorganization, leading to increased PROM. 1,2,7 Previous research has indicated that the longer the period of orthotic use, the greater the extent of contracture resolution. 3,6,8 Flowers and LaStayo 8 developed the term total end range time (TERT) to describe the accumulative amount of time that the stiff joint is held at the end of available ROM 38 JOURNAL OF HAND THERAPY

2 under tension using an orthosis. In a landmark study, these authors examined the impact of TERT on contracture resolution over nine days of serial casting. 8 Fifteen participants with a total of 20 proximal interphalangeal (PIP) joint flexion contractures were randomly allocated to one of two groups. Participants in both groups were observed to make approximately twice the gains in ROM over their six-day casting period (average 5.3 degrees) compared with the three-day period (3.0 degrees), regardless of the treatment order. Hence, Flowers and LaStayo 8 concluded that increasing the duration of treatment with the cast (i.e., six vs. three days), resulted in a proportional improvement in PROM. Glasgow et al. 3 explored the importance of daily TERT in optimizing contracture resolution over four weeks of orthotic treatment (splint), using a sequential clinical trial. These authors included both flexion and extension deficits in their sample and found that participants who used their orthosis for six to 12 hours per day made faster progress with contracture resolution than those who used their orthosis for less than six hours per day. Less is known, however, about the long-term relationship between orthotic use and progress with contracture resolution. Prosser 6 provides the only published study that we have been able to identify that considers the effect of long-term orthotic use in the hand. In a study of 22 PIP joint extension deficits, Prosser 6 studied progress with contracture resolution until treatment plateau was reached. Prosser 6 does not define how treatment plateau was measured but states that 4.3 months of treatment was required on average. McClure et al. 9 provide a useful algorithm to assist therapists with the implementation of dynamic orthotic devices in patient care. Specifically, this algorithm helps therapists identify suitable candidates for orthotic treatment and assists with the prescription of reasonable treatment dosage, considering parameters of intensity, frequency, and duration. These authors recommend that if progress appears to plateau, the duration of treatment should first be increased followed by the intensity. 9 Additionally, McClure et al. 9 suggest that it may take up to two months of treatment with orthotic use in long-standing contractures before any change in PROM may be observed. Glasgow et al. 10 have also noted that poorer progress with orthotic treatment is observed when the contracture has been present for a longer period of time. Understanding the nature of the long-term relationship between duration of orthotic use and contracture resolution has important implications for patient care. At present, it can be difficult to maintain patient interest and compliance with treatment if the rate of progress is slow with little improvement in ROM observed from week to week. Clinically, it can be difficult to assess when a joint has plateaued with treatment and when slow collagen growth and small gains in ROM are continuing to occur. For example, if the involved joint has only improved a few degrees over a month does this justify continuing orthotic use or does this apparent small gain reflect day-to-day variation, or alternatively, measurement error? As a result, the clinician may disband the orthotic program too early in favor of trialing other therapy techniques or, alternatively, continue treatment beyond the useful period of time. Conversely, holding a joint still with the goal of improving PROM may result in some of the negative changes associated with immobilization if continued indefinately. 11e13 Given an adequate daily TERT dosage, does improvement in ROM continue to occur after several months of treatment? Do flexion deficits respond differently to orthoses than extension deficits and if so should they be managed differently? For how many weeks or months should orthoses be continued before the decision to wean from treatment is made? Consequently the aims of this study were as follows: 1. Describe the long-term relationship between the weeks of treatment using dynamic orthoses, and progress with contracture resolution in the stiff PIP joint. 2. To describe the response to orthotic use in PIP flexion versus extension deficits over time. METHODS Participants A total of 41 participants (48 joints) with either a flexion or extension deficit at the PIP joint were recruited to the study from the Hand clinics at EKCO Occupational Services in Brisbane, Queensland, Australia from November 2004 to May This sample of 48 PIP joints was a subset from a larger group of patients (both metacapophalangeal and PIP joints) involved in a prospective cohort project conducted by the authors. 10 Participants were recruited to the study if they had a history of traumatic injury resulting in a contracture of the PIP joint with PROM 80% or less than that of the unaffected side (to justify the use of a dynamic orthosis). Patients who had previously used a dynamic orthosis for the presenting injury were excluded from the study, as were those with abnormal tone/paralysis associated with central nervous system dysfunction, acute complex regional pain syndrome, inflammatory arthritic conditions, infection, or artificial joints. Overall 13 potential participants were excluded resulting in the final sample of 41 patients (48 joints). Ethical approval for this project was obtained from the University of Queensland and the recruitment site. All participants provided informed voluntary consent. JanuaryeMarch

3 Study Variables Baseline information was collected on clinical characteristics including; age (years), time since injury (weeks), pretreatment joint stiffness (modified Weeks Test), 10,14,15 gender, digit (index, middle, ring, little), insurance status (workcover, non-workcover), and diagnosis (fracture, volar plate injury, soft tissue injury). The main predictor variable was the number of weeks of orthotic treatment (duration). The amount of TERT accrued each week (weekly TERT) was also used in analyses to control for individual variation in orthotic wear time, occurring from week to week. The outcome variable, extent of contracture resolution, was assessed using progress with AROM (flexion/extension) and TROM (flexion/extension), both measured in degrees. Materials A standard silver finger goniometer (Smith & Nephew Inc., Germantown, WI) was used to take all AROM and TROM measurements. In addition to the silver finger goniometer, a Haldex tension gauge (JID tools Jonard, Tuckahoe, NJ) was used to take TROM measurements. The Haldex gauge was also used to set the tension of the orthoses. Procedures All assessments and interventions were provided by the principal researcher and included the following: 1. A verbal history was taken and baseline cold AROM and TROM were recorded at the initial assessment. PROM was assessed using a Haldex gauge to apply a force of 500 gm/cm 2 in the movement of interest. 2. A dynamic orthotic device to suit the movement deficit was constructed. All patients with extension deficits used handmade capener orthoses constructed using the same design. All patients with flexion deficits used the same style of dynamic flexion orthosis, again constructed using the same design. A mobilizing force of 200e250 gm/cm 2 was set for each orthosis (Figures 1 and 2). 3. A modified version of the Weeks Test assessment of joint stiffness was conducted. 10,14,15 This method of evaluating joint stiffness has been previously found by the authors to predict outcome with dynamic orthotic treatment. 10 The dynamic orthosis was applied to the affected joint for 30 minutes and the change in AROM observed during this time was recorded as the estimate of joint compliance and subsequent stiffness. A hot pack was used in conjunction with the orthosis for the first 10 minutes. A large change in AROM over the 30-minute test indicated mild joint stiffness and a small change in AROM indicated greater joint stiffness. FIGURE 1. Setting tension for a handmade capener orthosis used to correct PIP extension deficit. The tip of the Haldex gauge is applied to the distal end of the orthosis over the middle phalanx and pushed down until the correct tension is reached. The Velcro strap is then used to secure the orthosis in the set position. 4. Following preconditioning using the modified Weeks Test, both AROM and TROM were reevaluated warm. ROM was measured to the nearest degree. 5. All participants were provided with a diary and instructed to accurately record the actual number of hours/day they used their orthosis. Participants were advised to use their orthosis for a minimum of six to 12 hours per day as suggested by previous research Participants attended therapy every one to two weeks so that their progress could be monitored. The biomechanics and tension of the dynamic orthosis were checked and if necessary adjusted at each therapy session. Specifically, FIGURE 2. The tip of the Haldex gauge is passed through the end of the elastic band on the traction of a dynamic flexion orthosis to set tension. The elastic band and Haldex applicator are pulled proximally until the desired tension is reached. The Velcro loop attached to the end of the elastic band is then secured to the proximal edge of the thermoplastic base. 40 JOURNAL OF HAND THERAPY

4 a. A force of 200e250 gm/cm 2 was set for each orthosis on initial construction and this tension was checked and corrected as needed at each subsequent therapy session to maintain the force at this level throughout the treatment program. This mobilizing force was chosen on the basis of recommendations by previous authors that if using a 4e5 cm 2 sling/strap, a pressure of 50 gm/cm 2 could be tolerated for long periods of time without causing tissue ischemia and skin breakdown. 1,16e18 b. AROM and TROM were re-evaluated (post preconditioning) to assess progress with treatment. c. Participants were encouraged to increase their daily TERT with orthotic use if ROM progress had appeared to slow All participants received a standard core treatment program including; the dynamic orthosis, active and assisted ROM, and edema management. Data Analysis Descriptive statistics (means, standard deviation [SD], medians, percentages) were initially computed. Four mixed-effect multiple regression analyses (using the Mixed procedure in SAS, version 9.2) using a forced entry method were then conducted. The outcome variables were estimates of AROM and TROM flexion (for flexion deficits), and estimates of AROM and TROM extension (for extension deficits), across the weeks of orthotic treatment. The main predictor variable was duration of orthotic treatment (number of weeks). All analyses were adjusted for clinical variables that have previously been shown to be associated with contracture resolution and treatment using a dynamic orthotic device, namely pretreatment joint stiffness, time since injury, and diagnosis. 3,8,10 Additionally, the variable weekly TERT was used in analyses to control for individual variation in orthotic use from week to week. All regression analyses were adjusted by the relevant baseline extension or flexion values (AROM and TROM). Alpha was set at p # The regression analyses yielded least square means (95% confidence intervals [CIs]) for weeks of treatment and beta coefficients (95% CIs) for weekly TERT. To map progress over weeks of treatment, the adjusted estimates of AROM and TROM flexion or extension (from the regression analyses) were plotted and trend lines fitted. To test whether there was a significant change in the trend lines shown on the plots, the Joinpoint Regression Program, version ,20 was used for each outcome. Joinpoint models are models where several different trend lines are connected together at the Joinpoints. The model takes trend data and fits the simplest Joinpoint model that the data allow given the minimum and maximum number of Joinpoints specified. The Joinpoint analyses yielded estimates of the change in degrees (beta coefficients, standard errors) for both AROM and TROM, according to the movement deficit (flexion or extension). Joinpoint tests whether or not an apparent change in trend is statistically significant at p # Although the data collection period extended to 26 weeks, due to drop out, useable data were only available to plot AROM flexion, TROM flexion, and AROM extension for 17 weeks, and TROM extension for 16 weeks. RESULTS Participants Characteristics Clinical characteristics of the 41 patients (n ¼ 48 joints) are presented in Table 1. Differences were observed between those with flexion versus extension deficits in degree of pretreatment joint stiffness (modified Weeks Test score), average age, time since injury, affected digit, and diagnosis. Over the course of the study, flexion deficits responded differently to orthotic treatment than extension deficits. Differences were observed in progress with AROM and TROM, and with the required daily TERT (Table 1). For the 41 patients (n ¼ 48 joints), usable data for the multiple regression and Joinpoint analyses were available for 16e17 weeks. After this time, there was a high amount of missing data. PIP Joint Flexion Deficits AROM Flexion Both the number of weeks of orthotic treatment and weekly TERT were associated with progress with AROM, after adjustment for baseline AROM, time since injury, diagnosis, and joint stiffness (Table 2). Figure 3 plots the weekly least square means estimates from the multiple regression analyses, illustrating the improvement in AROM flexion over 17 weeks of treatment. The Joinpoint regression analysis of trends showed that the trend line changed significantly after 12 weeks of orthotic use (p ¼ 0.004), indicating minimal progress with treatment after this point in time. Estimates from this analysis showed that patients had an average improvement of 1.77 (standard error [SE] 0.14) degrees each week (or 7.08 degrees over four weeks) for the first 12 weeks. After this, the average improvement was only 0.17 (SE 0.18) degrees each week (or 0.68 degrees over four weeks). TROM Flexion Both the number of weeks of orthotic treatment and weekly TERT were associated with progress with TROM, after adjustment for baseline TROM, time JanuaryeMarch

5 Characteristic TABLE 1. Clinical Characteristics of the 41 Patients (n ¼ 48 Joints) Full Sample (n ¼ 48 Joints) Flexion Deficit (n ¼ 26 Joints) Extension Deficit (n ¼ 22 Joints) Mean age in years (SD, range) 42.0 (12.4, 15e72) 45.3 (12.6, 15e63) 38.1 (11.4, 20e72) Mean time since injury in weeks (SD, range) 12.4 (7.8, 5e31) 14.1 (9.7, 5e31) 10.3 (4.1, 5e20) Mean modified Weeks Test score in degrees (SD, range) 12.6 (6.7, 2e40) 14.2 (7.7, 3e40) 10.8 (4.9, 2e24) Gender (%) Female Male Digit (%) Index Middle Ring Little Insurance status (%) Workcover Non-workcover Diagnosis (%) Fracture Volar plate injury Soft tissue injury Mean improvement in AROM (SD, range) 29.4 (15.6, 5e72) 35.1 (17.4, 5e72) 22.0 (8.8, 6e38) Mean improvement in TROM (SD, range) 23.8 (10.6, 6e50) 25.4 (12.7, 6e50) 21.7 (7.2, 7e34) Mean daily TERT in hours (SD, range) 7.7 (2.9, 4.0e14.5) 6.2 (1.3, 4.0e8.6) 10.8 (2.1, 7.7e14.5) AROM ¼ active range of motion; PROM ¼ passive range of motion; TERT ¼ total end range time; SD ¼ standard deviation. since injury, diagnosis, and joint stiffness (Table 2). Figure 4 plots the weekly least square means estimates from the multiple regression analyses, showing the improvement in TROM with the use of flexion orthoses over 17 weeks of treatment. The Joinpoint regression analysis of trends did not show any statistically significant change in the trend line over the duration of orthotic use. Estimates from this analysis showed that the patients had an average improvement of 1.03 degrees (SE 0.11) each week (or 4.12 degrees over four weeks). PIP Joint Extension Deficits AROM Extension Both the number of weeks of orthotic treatment and weekly TERT were associated with progress with AROM, after adjustment for baseline AROM, time since injury, diagnosis, and joint stiffness (Table 3). Figure 5 plots the weekly least square means estimates from the multiple regression analyses, showing the improvement in AROM extension over the course of the study. No statistically significant signs of plateau or change in the trend line were evident from the Joinpoint regression analysis of trends. Estimates showed that the patients had an average improvement of 0.72 degrees each week (SE 0.05) (or 2.88 degrees over four weeks). TROM Extension Duration of orthotic treatment (weeks) was associated with progress with TROM, after adjustment for baseline TROM, time since injury, diagnosis, and joint stiffness (Table 3). Figure 6 plots the weekly least square means estimates from the multiple regression analyses, showing the improvement in TROM extension over the duration of orthotic use (weeks). The Joinpoint regression analysis of trends showed that the trend line changed significantly after four weeks of orthotic treatment (p ¼ 0.020), indicating a slower improvement after that time. Estimates showed that the patients had an average improvement of 1.88 (SE 0.59) degrees each week (or 7.52 degrees over four weeks) for the first four weeks. After this, the average improvement was 0.52 (SE 0.11) degrees each week (or 2.08 degrees over four weeks). TABLE 2. Results of Mixed-effect Multiple Regression Analyses of AROM and TROM Flexion Predictor Variables AROM Flexion TROM Flexion Week of treatment a p # b p # Weekly TERT beta coefficient (95% CIs) 0.06 (0.011, 0.106) p ¼ (0.015, 0.099) p ¼ TERT ¼ total end range time; CI ¼ confidence interval. a ¼ Weekly least square means estimates (95% CIs) for AROM flexion appear in Figure 3. b¼ Weekly least square means estimates (95% CIs) for TROM flexion appear in Figure 4. Note: All analyses adjusted for relevant baseline AROM or TROM flexion values, pretreatment joint stiffness, time since injury, and diagnosis. 42 JOURNAL OF HAND THERAPY

6 FIGURE 3. Least square means estimates (95% confidence intervals) for active range of motion (AROM) flexion in degrees over 17 weeks of orthotic treatment. Adjusted for AROM flexion at baseline, joint stiffness, time since injury, diagnosis, and weekly total end range time. DISCUSSION The purpose of this study was to describe the longterm relationship between the number of weeks of treatment using a dynamic orthosis and progress with contracture resolution in the stiff PIP joint. Additionally, we aimed to describe the response to dynamic orthotic treatment of PIP flexion versus extension deficits over time. Although we acknowledge that considerable individual variation is to be expected in relation to response to orthotic treatment based on a range of clinical factors, our aim was simply to obtain a general idea of the average progress that might be expected. If both patient and therapist are aware from the beginning of treatment of the potential duration and subsequent commitment that will be required with orthotic treatment, it is likely that realistic expectations for recovery will result. Our sample appeared representative of the wider population of hand-injured patients undergoing orthotic treatment for joint contracture (i.e., mostly men, little finger most commonly affected, average time since injury 14 weeks, average daily TERT eight hours). 3,6,8,21 However, differences were observed between participants with flexion and extension deficits at baseline and in progress with orthotic use. Participants with extension deficits were younger than those with flexion deficits (38.1 vs years) and had a greater degree of pretreatment stiffness (lower modified Weeks Test score; 10.8 vs degrees). This was despite averaging a shorter time since injury (extension deficits 10.3 weeks, flexion deficits 14.1 weeks). Over the course of the study, participants with extension deficits demonstrated less improvement in both AROM and TROM than those with flexion deficits despite averaging a longer daily TERT (extension deficits 10.8 hours per day, flexion deficits 6.2 hours per day). These findings reflect the clinical experience that the PIP joint often feels stiffer into extension than flexion and that it is harder to regain extension at the PIP joint than flexion. Differences in anatomy between the volar and dorsal aspect of the PIP joint may contribute to this phenomenon. The palmar plate of the PIP is a particularly strong fibrocartilaginous structure important for stabilizing the volar aspect of the joint and preventing dorsal dislocation. 22,23 Injury involving, or in the vicinity of this structure is notoriously linked to the loss of PIP extension as scar tissue tightens the plate and increases the flexion angle. In contrast, dorsal PIP joint stability is provided via the dorsal extensor apparatus and the weaker dorsal fibrocartilaginous plate. 22,23 These structures theoretically provide less resistance to motion than their volar counterpart and may consequently respond more positively to the use of a dynamic orthosis. The Relationship between Weeks of Orthotic Treatment and Contracture Resolution FIGURE 4. Least square means estimates (95% confidence intervals) for torque range of motion (TROM) flexion in degrees over 17 weeks of orthotic treatment. Adjusted for TROM flexion at baseline, joint stiffness, time since injury, diagnosis, and weekly total end range time. The number of weeks of treatment with orthoses and the amount of TERT accrued each week were both strongly associated with contracture resolution. When orthotic use was aimed at improving flexion, AROM and TROM increased in a linear fashion with minimal improvement in AROM observed after 12 weeks of treatment. In contrast TROM flexion appeared to continue to slowly improve across 17 weeks of treatment. This may reflect that the stiffness within the joint was continuing to reduce. Additionally, the PIP joint tends to have a soft or springy end feel JanuaryeMarch

7 TABLE 3. Results of Mixed-effect Multiple Regression Analyses of AROM and TROM Extension Predictor Variables AROM Extension TROM Extension Week of treatment a p # b p # Weekly TERT beta coefficient (95% CIs) 0.06 ( 0.12, 0.006) p ¼ ( 0.12, 0.001) p ¼ TERT ¼ total end range time; CI ¼ confidence interval. a ¼ Weekly least square means estimates (95% CIs) for AROM extension appear in Figure 5. b¼ Weekly least square means estimates (95% CIs) for TROM extension appear in Figure 6. Note: All analyses adjusted for relevant baseline AROM or TROM extension values, pretreatment joint stiffness, time since injury, and diagnosis. into flexion with a certain amount of compliance observed even in uninjured joints placed under stress. The TROM measures used in this study did not represent full end PROM. In general measures of TROM (assessed at 500 gm/cm 2 ) were less than those observed for AROM. Likewise, when assessing joint stiffness using the torque angle curve technique, we have often found that ROM assessed with force as high as 800 gm/cm 2 is less than that achieved by the patient actively. The reason for choosing 500 gm/cm 2 in the present study is that along with recommendations from previous authors, 24 we have found that the use of force greater than 600 gm/cm 2 is not always well tolerated by all people in all digits. This is frequently the case when assessing the little finger, the most frequently injured digit in our sample. The primary complaint from patients with the use of force greater than 600 gm/cm 2 is that they experience discomfort across the dorsum of the PIP joint due to pressure applied while stabilizing the goniometer on the back of the joint. Despite these limitations, TROM is used in research trials as an alternative to PROM due to high-demonstrated reliability. 3,8,25,26 The TROM procedure chosen for use in the present study was identical to that used in previous research conducted by the authors indicating intrarater reliability (intraclass correlation coefficient [ICC] 3, 1), inter-rater reliability (ICC 2, 1), and testeretest reliability (ICC 2, 1) all greater than These reliability estimates are considerably higher than estimates obtained by previous authors for the reliability of finger PROM. 27 Consequently, by using a consistent force (500 gm/cm 2 ) we were able to accurately evaluate progress with contracture resolution over the duration of treatment and hence gain a sound understanding of the trend with which recovery of PROM occurred. Aside from a slowing of progress with TROM extension after four weeks of orthotic use, Joinpoint analysis of the extension deficit group indicated continuing slow improvement in both AROM and TROM, during the 16e17 weeks of treatment with no sign of plateau in progress. Again this finding reflects the clinical experience that it is more difficult to restore extension ROM at the PIP joint and indicates that orthotic treatment aimed at improving extension may need to be continued for a longer period of time than if the goal of treatment is to improve flexion (i.e.,.4 months on average). Additionally, greater daily TERT may be required (10.8 vs. 6.2 hours per day in our sample) to maximize potential recovery. FIGURE 5. Least square means estimates (95% confidence intervals) for AROM extension in degrees over 17 weeks of orthotic treatment. Adjusted for AROM extension at baseline, joint stiffness, time since injury, diagnosis, and weekly total end range time. FIGURE 6. Least square means estimates (95% confidence intervals) for TROM extension in degrees over 16 weeks of orthotic treatment a. Adjusted for TROM extension at baseline, joint stiffness, time since injury, diagnosis, and weekly total end range time. a Only 16 weeks of data were available for analysis. 44 JOURNAL OF HAND THERAPY

8 This finding is similar to that of Prosser 6 who found that an average of 4.3 months was required to maximize recovery of extension at the PIP joint using dynamic orthoses with average daily TERT of ten hours. Study Limitations Limitations relating to the use of the TROM technique as a measure of PROM have already been discussed. Small sample size is another limitation of this study. It is not possible to exclude that, due to the small number of participants, the regression analyses lacked sufficient power to detect significant relationships. Additionally, the length of follow-up was also a limitation. We found that few participants were willing to continue with therapy beyond 17 weeks. This was because the majority of them were happy with their gains in functional ROM by this time, and felt that they could perform their daily tasks adequately within their movement restrictions. Some planned to continue their orthotic program at home on their own. However, few people were committed to attending therapy any longer than this, given that most patients were privately insured and hence financially responsible for their own treatment (77.1%). A further limitation of this project relates to the use of a cohort study design. This design was chosen as we aimed to describe progress with orthotic use prospectively over time, rather than to test the relationship between variables or different interventions. Due to the lack of previous research in this area, the nature of this study was exploratory and descriptive. However, without the use of a control group, it is difficult to eliminate the effect of potential confounding variables on outcome. For example, it is possible that the exercise program contributed to the progress with contracture resolution and that this impacted on the response to treatment observed. Additionally, it is also possible that to a certain extent ROM simply improved over time (known as a maturation effect). 28 To overcome this limitation, all multiple regression procedures used in the data analysis were adjusted for clinical variables that have previously been shown to be associated with contracture resolution and orthotic treatment. Additionally, the variable weekly TERT was used in analyses to control for individual variation in orthotic use from week to week. However, causation cannot be conferred from the analyses findings. The weeks of orthotic treatment does explain the variance noted in the AROM and TROM outcome, but cannot be declared as having been the sole cause of the change in ROM observed. Clinical Implications and Recommendations Findings from this study confirm the importance of the duration of treatment (in weeks), in promoting contracture resolution with dynamic orthotic use. ROM continued to improve over several months of orthotic use with flexion deficits recovering faster and reaching a plateau in treatment, before extension deficits. Extension deficits were stiffer on average than flexion deficits and appeared to recover more slowly, despite averaging greater daily TERT. These findings warrant consideration in the development of orthotic wearing regimens. Specifically, Faster recovery of ROM may be expected when the goal of orthotic use is to improve flexion at the PIP joint. In our sample, the majority of flexion gains were made within 12 weeks of treatment. Slower progress may be observed with the use of extension orthoses and further research is needed over a longer timeframe (.4 months). Longer daily TERT may be needed when using dynamic orthotic devices to improve extension compared with flexion, with participants in this study averaging 10.8 hours per day with extension orthoses, and 6.2 hours per day with flexion orthoses. Further research is needed to explore this concept further. CONCLUSIONS The duration of treatment with dynamic orthoses is a key factor influencing contracture resolution in the stiff PIP joint, with ROM continuing to improve over several months of treatment. We observed greater gains in ROM in a shorter period of time if treatment was aimed at improving flexion rather than extension. Participants using flexion orthoses made most of their gains in AROM in the first 12 weeks of treatment. In contrast, slow improvement in extension range was observed to continue beyond four months of treatment. Further research is needed to evaluate response to extension orthoses over a longer timeframe. Longer average daily TERT may be required when orthotic treatment is aimed at improving extension rather than flexion. Further research is needed to replicate and build on our findings. Acknowledgments The authors would like to thank the Australian Hand Therapy Association for a scholarship grant that helped to make this research possible. REFERENCES 1. Brand PW, Hollister AM, Giurintano D, Thompson DE. External stress: forces that affect joint action. In: Brand PW, Hollister AM (eds). Clinical Mechanics of the Hand. St Louis: Mosby, pp Fess EE, McCollum M. The influence of splinting on healing tissues. J Hand Ther. 1998;11(2): JanuaryeMarch

9 3. Glasgow C, Wilton J, Tooth L. Optimal daily end range time for contracture resolution in hand splinting. J Hand Ther. 2003; 16(3): Glasgow C, Fleming J, Tooth L. Which splint? Dynamic versus static progressive splinting to mobilize stiff joints in the hand. Br J Hand Ther. 2008;14(4): Wilton JD. Biomechanical principles of design, fabrication and application. In: Wilton JD (ed). Hand Splinting. London: WB Saunders Company Ltd, pp Prosser R. Splinting in the management of proximal interphalangeal joint flexion contracture. J Hand Ther. 1996;9(4): Light KE, Nuzik S, Personius W, Barstrom A. Low-load prolonged stretch vs. high-load brief stretch in treating knee contractures. Phys Ther. 1984;64: Flowers KR, LaStayo P. Effect of total end range time on improving passive range of motion. J Hand Ther. 1994;7(3): McClure PW, Blackburn LG, Dusold C. The use of splints in the treatment of joint stiffness: biologic rationale and an algorithm for making clinical decisions. Phys Ther. 1994;74(12): Glasgow C, Tooth L, Fleming J, Peters S. Dynamic splinting for the stiff hand following trauma: predictors of contracture resolution. J Hand Ther. 2011;24(3): Akeson WH, Woo SL-Y, Amiel D, Coutts RD, Daniel D. The connective tissue response to immobility: biomechanical changes in periarticular connective tissue of the immobilized rabbit knee. Clin Orthop. 1973;93: Akeson WH, Amiel D, Mechanic GL, Woo SL-Y, Harwood FL, Hamer ML. Collagen cross-linking alterations in joint contractures: changes in the reducible cross-links after nine weeks of immobilization. Connect Tissue Res. 1977;5: Akeson WH, Amiel D, Abel MF, Garfin SR, Woo SL-Y. Effects of immobilization on joints. Clin Orthop. 1987;219: Flowers KR. A proposed decision hierarchy for splinting the stiff joint, with an emphasis on force application parameters. J Hand Ther. 2002;15(2): Weeks PM, Wray RC. Operate, rehabilitate, or rate. In: Weeks PM, Wray JC (eds). Management of Acute Hand Injuries; a Biological Approach. St Louis: The CV Mosby Company, pp Fess EE. Force magnitude of commercial spring-coil and spring-wire splints designed to extend the proximal interphalangeal joint. J Hand Ther. 1988;1(1): Fess EE, Gettle KS, Philips CA, Janson JR. Mechanical principles. In: Fess EE, Gettle KS, Philips CA, Janson JR (eds). Hand and Upper Extremity Splinting Principles and Methods. 3rd ed. St Louis: Elsevier Mosby, pp Fess EE, Gettle KS, Philips CA, Janson JR. Principles of using outriggers and mobilization assists. In: Fess EE, Gettle KS, Philips CA, Janson JR (eds). Hand and Upper Extremity Splinting Principles and Methods. 3rd ed. St Louis: Elsevier Mosby, pp Kim HJ, Fay MP, Feuer EJ, Midthune DN. Permutation tests for joinpoint regression with applications to cancer rates. Stat Med. 2000;19:335 51, (correction: 2001;20:655). 20. National Cancer Institute. Statistical Research and Applications Branch Joinpoint Regression Program, Version 3.4 National Cancer Institute, September Weeks P, Wray R, Kuxhaus M. The results of non-operative management of stiff joints in the hand. Plast Reconstr Surg. 1978;61: Chinchalkar SJ, Gan BS. Management of proximal phalangeal fractures. J Hand Ther. 2003;16(2): Schmidt H-M, Lanz U. Distal palm and proximal fingers. In: Schmidt H-M, Lanz U (eds). Surgical Anatomy of the Hand. Stuttgart: Thieme, pp Breger-Lee D, Tomancik Voelker E, Giurintano D, Novick A, Browder L. Reliability of torque range of motion: a preliminary study. J Hand Ther. 1993;6: Birke JA, Cornwall MW, Jackson M. Relationship between hallux limitus and ulceration of the great toe. J Orthop Sports Phys Ther. 1988;10: Guidice ML. Effects of continuous passive motion and elevation on hand oedema. Am J Occup Ther. 1990;44: Lewis E, Fors L, Tharion WJ. Interrater and intrarater reliability of finger goniometric measurements. Am J Occup Ther. 2010; 64: Portney LG, Watkins MP. Experimental control. In: Portney LG, Watkins MP (eds). Foundations of Clinical Research Applications to Practice. Stamford: Appleton & Lange, pp JOURNAL OF HAND THERAPY

10 JHT Read for Credit Quiz: Article #213 Record your answers on the Return Answer Form found on the tear-out coupon at the back of this issue or to complete online and use a credit card, go to JHTReadforCredit.com. There is only one best answer for each question. #1. The purpose of the study was to examine the a. effect of dynamic vs. static progressive splinting in resolving PIP joint contractures b. effect of dynamic vs. static splinting in resolving PIP joint contractures c. short term relationship between weeks of treatment using dynamic orthoses and contracture resolution, in both flexion and extension deficits of the PIP joint d. long term relationship between weeks of treatment using dynamic orthoses and contracture resolution, in both flexion and extension deficits of the PIP joint #2. ROM a. decreased b. remained constant c. increased in a linear fashion d. increased in a geometric fashion #3. The results showed that a. flexion was more easily restored than extension b. extension was more easily restored than flexion c. flexion and extension were restored with equal ease d. flexion and extension were restored with equal difficulty #4. Extension contractures uniformly plateaued in a. greater than 17 weeks b. 12 weeks c. 8 weeks d. 6 weeks #5. The study demonstrated that there was a direct correlation between total wearing time (of the orthotic device) and contracture resolution a. false b. true When submitting to the HTCC for re-certification, please batch your JHT RFC certificates in groups of 3 or more to get full credit. JanuaryeMarch