529074 research-article2014
JHS0010.1177/1753193414529074The Journal of Hand SurgeryRodrigues et al.
JHS(E)
Full length article
Dynamism in Dupuytren’s contractures J. N. Rodrigues1, W. Zhang2, B. E. Scammell1 and T. R. C. Davis1
The Journal of Hand Surgery (European Volume) 2015, Vol. 40E(2) 166–170 © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1753193414529074 jhs.sagepub.com
Abstract Dynamism of Dupuytren’s contractures may occur if a contracture crosses over both the metacarpophalangeal (MCPJ) and proximal interphalangeal (PIPJ) joints of one finger. In this situation the extension deficit at one joint can be influenced by the position of the other. This may affect clinical measurements and introduce errors and bias into research using angular deformity as an endpoint. This study reports the dynamism encountered when measuring passive joint extension deficits in pre-operative contractures. Eighty-five digits with a contracture affecting the PIPJ or MCPJ and PIPJ on 72 hands from 70 patients were studied. Seventy-six digits showed dynamism at either the MCPJ or PIPJ (89%). Seventy-four showed dynamism at the PIPJ (87%). The mean dynamism observed was 6° at the MCPJ and 14° at the PIPJ. Previous Dupuytren’s surgery to the finger did not influence the amount of dynamism seen. Dynamism is common and may be a source of error or bias in trials of Dupuytren’s disease treatment. Level of evidence: III Keywords Dynamism, Dupuytren’s contracture, Dupuytren’s disease, goniometry, finger, joint Date received: 28th December 2013; revised: 9th February 2014; accepted: 19th February 2014
Introduction Many studies of surgery for Dupuytren’s disease report ‘recurrence rates’ after treatment, but often without providing a definition of recurrence (Becker and Davis, 2010). Systematic reviews of Dupuytren’s disease have demonstrated no consistent definition of recurrence (Becker and Davis, 2010; Werker et al., 2012). When recurrence is defined, the most common definition is the recurrence of a specific angular deformity. Seventeen variations, such as an angular deformity of 30°, are reported (Ball et al., 2013). Improvement in angular deformity has been the primary endpoint of the two most recent and high-profile randomized controlled trials of Dupuytren’s disease treatment (Hurst et al., 2009; van Rijssen et al., 2006). Return of angular deformity was used to assess recurrence as the primary outcome in the 5-year follow-up of the latter trial (van Rijssen et al., 2012). If a Dupuytren’s contracture spans both the MCPJ and PIPJ, the severity of the passive flexion deformity of one of these joints may be influenced by the position of the other when the measurement is taken through what is referred to as dynamism (Hurst, 2010). Thus, if the metacarpophalangeal joint (MCPJ)
is held in maximal passive flexion, then the flexion deformity at the proximal interphalangeal joint (PIPJ) may be partially or completely relieved. Conversely, if the MCPJ is held in maximal passive extension, then the PIPJ flexion deformity may be exaggerated (Figure 1). To minimize the effect of such dynamism, observers may hold the other joints of the finger in maximum passive flexion when measuring a flexion deformity of a joint. This measures a ‘minimized’ passive extension deficit, rather than the active deficit encountered by the patient, which might be largely due to dynamism.
1Division
of Orthopaedic & Accident Surgery, University of Nottingham & Nottingham University Hospitals NHS Trust, Nottingham, UK 2Division of Academic Rheumatology, University of Nottingham, Nottingham, UK Corresponding author: JN Rodrigues, Division of Orthopaedic & Accident Surgery, University of Nottingham & Nottingham University Hospitals NHS Trust, C-Floor, West Block, Queen’s Medical Centre, Derby Road, Nottingham, NG7 2UH, UK. Email: [email protected]
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Figure 1. Schematic illustration of dynamism. The Dupuytren’s cord (shown in blue) is not elastic and has fixed attachments to the palmar aponeurosis in the palm and flexor sheath in the middle pulp space. (a) Extension of the MCPJ tightens the cord at the PIPJ, pulling it into flexion and generating the ‘worst’ PIPJ angle. Alternatively, passive flexion of the PIPJ relaxes the cord and allows increased extension at the MCPJ, giving the ‘best’ MCPJ angle. (b) Flexion of the MCPJ relaxes the same cord at the PIPJ and allows increased extension, generating the ‘best’ PIPJ angle. Alternatively, passive extension of the PIPJ tightens the cord and pulls the MCPJ into flexion, giving the ‘worst’ MCPJ angle.
Dynamism may also reduce the correlation between passive angles measured by an observer and the patient’s experience of the contracture, as the patient cannot achieve the milder contracture obtained by measuring passive extension angles at the MCPJ and PIPJ separately. Alternatively, active extension can be measured to more accurately represent the patient’s experience of an extension deficit. We are not aware of any reports of the potential impact of dynamism on angular joint measurements. Goniometry in general has good inter- and intra-observer reproducibility when assessed in controlled situations. When performed by hand therapists to measure joint angles in normal digits held in fixed positions by thermoplastic splints, inter-observer reproducibility was reported at 7–9° and intra-observer reproducibility at 4–5° (Ellis and Bruton, 2002). However, if common and significant, dynamism may introduce an important source of bias and error, which could influence reported recurrence rates. This could influence the outcome of studies reporting individual joint angles, but would also be relevant to studies of total passive extension deficit, as in such cases the individual joint angles are measured separately and then added to each other. This study aimed to establish the extent of dynamism on Dupuytren’s contractures affecting PIPJs awaiting surgery (with or without MCPJ involvement).
Methods These data are derived from the baseline data collection from a service evaluation study of early functional recovery following Dupuytren’s disease surgery. Data collection took place between February 2012 and May 2013. The inclusion criteria were patients meeting of all of the following: a) awaiting fasciectomy or dermofasciectomy at a single UK hand surgery service; b) primary or recurrent Dupuytren’s disease of one or more fingers; c) an extension deficit affecting the PIPJ of one of the digits when actively extending this digit; d) a pre-operative assessment clinic appointment scheduled for a date when the primary author (JR) was available to perform the measurements. Exclusion criteria were a) an isolated MCPJ contracture; b) cognitive impairment preventing informed consent; c) refusal of invitation to participate. Contractures that appeared to affect the PIPJ only were still included, as in these cases there may have been MCPJ dynamism within the range of hyperextension, which was not assessed in the study. However, as PIPJs do not typically hyperextend passively, MCPJ only contractures were excluded. Eligible patients who attended a routine orthopaedic preadmission clinic were issued with a letter explaining the project and inviting them to participate on a voluntary basis. A single surgeon assessed all patients who consented to participate. Demographic details, including previous surgery to the finger
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Table 1. Differences between ‘worst’ and ‘best’ angles at PIPJ by digit. Digit
Little Ring Middle Index
Sample size (n = 85) n (%)
Difference of worst – best angles at PIPJ, ° mean (95% CI)
55 (65) 19 (22) 8 (9) 3 (4)
11 (9–14) 20 (12–29) 16 (5–27) 64 (30–99)
involved, were recorded. Goniometry was performed to measure the extension deficits of the MCPJ and PIPJ of all digits that were to undergo surgery. This was initially performed with the other joint of the digit held in maximum passive flexion (thus minimizing the extension deficit measured, giving the ‘best’ measure), and was then repeated with the other joint of the digit in maximum passive extension (thus maximizing the extension deficit measured, giving the ‘worst’ measure). When assessing an MCPJ in which hyperextension was present, this was recorded as 0°, in keeping with the methodology used in previous studies of goniometry in Dupuytren’s disease (JeroschHerold et al., 2011). All measurements were performed using a Baseline® (Fabrication Enterprises Inc, White Plains, New York, USA) stainless steel goniometer, with markings at 5° increments. The single surgeon who performed all measurements used a standardized technique throughout. Analysis was performed using Prism 6.0 for Mac OS X (GraphPad® software, La Jolla, California, USA).
Results Ninety-one patients were considered for participation in this study. Fourteen were excluded because they had MCPJ only contractures and six declined to participate. One was excluded because she had Alzheimer’s disease that prevented informed consent. This left 85 digits on 72 hands from 70 patients who consented to participate. Fifty-five were men (79%) and the mean age was 67 years. The digits studied were predominantly little fingers (Table 1). Thirty-five of 85 digits studied (41%) had PIPJ only contractures. In these 35, the ‘best’ and ‘worst’ MCPJ angles obtained were both within hyperextension. By finger, the proportions of PIPJ only contractures were a) index 0/3 (0%), b) middle 1/8 (13%), c) ring 5/19 (26%), d) little 29/55 (53%), which were significantly different (p = 0.023, Chi-squared test). Seventy-six digits showed dynamism at either the MCPJ or PIPJ (89%). Seventy-four showed dynamism
Table 2. Best and worst angles. Joint
Best angle, ° mean (95% CI)
Worst angle, ° mean (95% CI)
Dynamism, ° mean (95% CI)
MCPJ PIPJ
19 (14–25) 49 (44–54)
25 (19–31) 63 (58–68)
6 (4–7) 14 (11–17)
at the PIPJ (87%), but only 35 (41%) MCPJs exhibited dynamism. Other MCPJs may have had dynamism within the range of hyperextension, which was not captured here. In nine digits there was more than 30° of dynamism at one joint (11%). The mean ‘best’ MCPJ angle was 19° and the mean ‘worst’ MCPJ angle was 25°. The mean range of dynamism for MCPJs was thus 6°, which represented a highly significantly difference between best and worst angles (p < 0.0001, paired t-test). The mean dynamism seen increased to a mean of 9° (95% CI 7–12) when those digits in which both ‘worst’ and ‘best’ MCPJ angles were 0° were excluded (as dynamism within the range of hyperextension might have been present in these digits, but was not assessed in this study). The mean ‘best’ PIPJ angle was 49° and the mean ‘worst’ PIPJ angle was 63°. Thus, the mean dynamism for PIPJs was 14°, which also represented a highly significant difference between best and worst angles (p < 0.0001, paired t-test). The results are shown in Table 2. Twenty-one fingers had undergone previous Dupuytren’s surgery (25%). Fingers that had already had surgery for Dupuytren’s disease had comparable ranges of dynamism to those that had not undergone previous surgery. For the MCPJ, the mean range of dynamism was 5o (95% CI 4–6) for digits that had previously undergone surgery and 6o (95% CI 2–9) for those that had not had previous surgery. For the PIPJ, the mean range of dynamism was 13o (95% CI 10–16) for fingers that had previously undergone surgery and 15o (95% CI 11–18) for those that had not had previous surgery. Results from different digits are presented in Table 1. The difference between ‘worst’ and ‘best’ MCPJ angles did not differ significantly between digits (p = 0.14, one-way analysis of variance [ANOVA]). However, the extent of PIPJ dynamism varied by digit (p < 0.0001, one-way ANOVA). When Tukey’s multiple comparisons test was applied, highly significant differences (p < 0.0001) were seen between the index and all other fingers. The only other significant difference was between the ring and little fingers (Table 3). There was a difference in the proportion of PIPJ-only contractures between the ring and little fingers (ring: 5/19 (26%) vs. little: 29/55 (53%); p = 0.046, Chi-squared test), which may have contributed to this.
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Rodrigues et al. Table 3. Differences in dynamism at the PIPJ between different digits (mean, 95% CI), significance levels from Tukey’s multiple comparisons test.
Index
Middle, °
Ring, °
Little, °
48 (70–26) p < 0.0001
44 (64–23) p < 0.0001 4 (−9 to 18) NS
53 (72–33) p < 0.0001 5 (17 to −8) NS 8 (18–0) p = 0.042
Middle Ring
Discussion Accurate intra- and inter-observer reproducibility of goniometry measurements taken by therapists have been previously reported (Ellis and Bruton, 2002). However, the study model did not reproduce the clinical situation, as measurements were taken from the fingers of a normal hand that was held in a fixed flexed posture by a thermoplastic splint. Thus, there was no possibility of measurement errors or differences due to dynamism or other patient and contracture factors, and the estimates of reproducibility are probably over optimistic. Dynamism may constitute a source of inadvertent measurement error or systematic bias in clinical trials of Dupuytren’s disease management. If observers are not blinded or are able to recognize the treatment that the patient has received from the scarring on the hand, conscious or subconscious bias may influence the angular measurement. In recent clinical trials of Dupuytren’s disease surgery, goniometric measurements were performed by unblinded surgeons (van Rijssen et al., 2006; 2012). Another recent high profile study defined treatment success as correction of angular deformity at single joint level to less than 5°, with recurrence defined as a subsequent increase in angular deformity of 20° or more (Hurst et al., 2009). The 14° mean range of dynamism at the PIPJ, or even just 6° at the MCPJ demonstrated in the present study, could have markedly altered the proportions of patients classified as successes or failures, or recurrences or no recurrences. In another paper describing late outcome of surgery, recurrence was defined as an increase in total passive extension deficit of 30° (van Rijssen et al., 2012), and dynamism could also have greatly influenced the results and conclusions. In the present study, index fingers showed the most dynamism. However, there were only three index fingers in the series, and so this difference should be interpreted with caution. The clinically important difference in range of motion for collagenase treatment of Dupuytren’s
disease has been estimated at 13.5° (Witthaut et al., 2011). The calculation reported in that study involved composite measurement of active extension and flexion, and thus would include both the MCPJ and PIPJ (Ellis and Bruton, 2002). In our study, the combined MCPJ and PIPJ dynamism was greater than this, at 19–23° (depending on whether or not those MCPJs in hyperextension were excluded). There are limitations to this comparison. ROM involves active flexion and extension, whereas the dynamism assessed here applies to passive measurements. Furthermore, the clinically important difference is context-specific. This value was calculated from a study of collagenase treatment, and it may vary for other treatment modalities. Nevertheless, it suggests that dynamism may give rise to inaccuracy in joint measurement that is clinically relevant. There are limitations to this study. One was that only pre-operative contractures were measured. In contrast, the results of trials consider pre- and postoperative angular deformities. However, 21 of the 85 fingers studied had undergone previous Dupuytren’s disease surgery, and these exhibited similar ranges of dynamism to the others. Thus, we believe our findings can be reasonably extrapolated to postoperative situation. The goniometer used only had 5° increments, which might be considered a source of inaccuracy. However, intra- and inter-observer reproducibility of goniometry has been reported at 4–5° and 7–9°, respectively, when studied in a highly controlled setting (Ellis and Bruton, 2002). Therefore, measuring angles to the nearest degree or two, rather than the nearest 5°, is probably not appropriate. The position of the carpometacarpal and distal interphalangeal joints (DIPJs) were not controlled during this study, and it is possible that their position may also influence dynamism. To be the case, there would need to be mobility of the palmar aponeurosis proximally and extension of the cord across the DIPJ distally. The latter is unusual, and most Dupuytren’s cords that cross the PIPJ are firmly attached to the flexor sheath over the middle phalanx, proximal to the DIPJ. Instead, Dupuytren’s disease may cause a Boutonnière deformity, with pathological hyperextension of the DIPJ. This might complicate the study of dynamism at the DIPJ. We believe that the standardization of measurements in this study, involving the same surgeon throughout, will have minimized this to allow study of dynamism at the MCPJ and PIPJ. Future study could investigate any influence of the position of these other joints, but it would be difficult for a single observer to passively manipulate the position of four joints within a ray at the same time. The results of the present study may represent the extreme range of dynamism, given that the ‘worst’
170 angles were obtained by passively manipulating the digit to exaggerate a contracture at a particular joint. This strategy was intentional, as the aim was to establish the maximum amount of dynamism achievable. However, it is unlikely that the full extent of dynamism would be encountered in a trial, unless bias was very marked, or some observers had been trained to measure angular deformities in a manner which, through dynamism, either maximized or minimized the angular deformity. Nonetheless, this work demonstrates just how large an impact dynamism might have on individual joint measurements. Even if only half the range of dynamism demonstrated in the present study actually occurred, altering nine out of 10 PIPJ measurements in a trial by a mean of 7° might shift the balance of success/failure of treatment or later recurrence/no recurrence significantly. The effect of dynamism on post-operative outcome assessment should be formally studied. In the meantime, reporting active (rather than passive) extension deficit might minimize its impact. Alternatively, a patient-reported outcome measure could be used as the primary outcome measure. This would avoid the impact of dynamism on trial outcome data, may provide a more meaningful description of hand function and the benefit of surgery, and align trial design with the growing use and study of patient-reported outcome data across in the UK National Health Service and other countries (Darzi, 2008; Mokkink et al., 2010). Acknowledgement JNR received educational support from a scholarship from the National Institute for Health and Care Excellence (NICE) during this project.
Conflict of interests None declared.
Ethical approval This study was a minor element of a larger service evaluation project studying treatment outcome in Dupuytren’s disease. In keeping with UK National Research Ethics Service guidance, it is exempt from ethical approval. Nottingham University Hospitals NHS Trust guidance for the conduct of service evaluation projects was followed.
Funding This work was supported by a British Society for Surgery of the Hand Research Fellowship, Nottingham Hospitals Charity and Nottingham Orthopaedic Walk.
The Journal of Hand Surgery (Eur) 40(2) References Ball C, Pratt AL, Nanchahal J. Optimal functional outcome measures for assessing treatment for Dupuytren’s disease: a systematic review and recommendations for future practice. BMC Musculoskelet Disord. 2013, 14: 131. Becker GW, Davis TR. The outcome of surgical treatments for primary Dupuytren’s disease—a systematic review. J Hand Surg Eur Vol. 2010, 35: 623–6. Darzi A. High quality care for all: NHS Next Stage Review final report. London: TSO, 2008. http://webarchive. nationalarchives.gov.uk/20130107105354/http://www. dh.gov.uk/en/Publicationsandstatistics/Publications/ PublicationsPolicyAndGuidance/DH_085825 (12 March 2014). Ellis B, Bruton A. A study to compare the reliability of composite finger flexion with goniometry for measurement of range of motion in the hand. Clin Rehabil. 2002, 16: 562–70. Hurst LC. Dupuytren’s contracture. In:Wolfe SW, Hotchkiss RN, Pederson WC, Kozin SH (Eds.) Green’s Operative Hand Surgery, 6th ed. Philadelphia, Elsevier ChurchillLivingstone, 2010. Hurst LC, Badalamente MA, Hentz VR et al. Injectable collagenase clostridium histolyticum for Dupuytren’s contracture. N Engl J Med. 2009, 361: 968–79. Jerosch-Herold C, Shepstone L, Chojnowski A, Larson D. Severity of contracture and self-reported disability in patients with Dupuytren’s contracture referred for surgery. J Hand Ther. 2011, 24: 6–10. Mokkink LB, Terwee CB, Knol DL et al. The COSMIN checklist for evaluating the methodological quality of studies on measurement properties: a clarification of its content. BMC Med Res Methodol. 2010, 10: 22. van Rijssen AL, Gerbrandy FS, Ter Linden H, Klip H, Werker PM. A comparison of the direct outcomes of percutaneous needle fasciotomy and limited fasciectomy for Dupuytren’s disease: a 6-week follow-up study. J Hand Surg Am. 2006, 31: 717–25. van Rijssen AL, ter Linden H, Werker PMN. Five-year results of a randomized clinical trial on treatment in Dupuytren’s disease: percutaneous needle fasciotomy versus limited fasciectomy. Plast Reconstr Surg. 2012, 129: 469–77. Werker PMN, Pess GM, van Rijssen AL, Denkler K. Correction of contracture and recurrence rates of Dupuytren contracture following invasive treatment: the importance of clear definitions. J Hand Surg Am. 2012, 37: 2095–105.e7. Witthaut J, Bushmakin AG, Gerber RA, Cappelleri JC, Le Graverand-Gastineau MP. Determining clinically important changes in range of motion in patients with Dupuytren’s contracture: secondary analysis of the randomized, double-blind, placebo-controlled CORD I study. Clin Drug Investig. 2011, 31: 791–8.
JHS0010.1177/1753193414529074The Journal of Hand SurgeryRodrigues et al.
JHS(E)
Full length article
Dynamism in Dupuytren’s contractures J. N. Rodrigues1, W. Zhang2, B. E. Scammell1 and T. R. C. Davis1
The Journal of Hand Surgery (European Volume) 2015, Vol. 40E(2) 166–170 © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1753193414529074 jhs.sagepub.com
Abstract Dynamism of Dupuytren’s contractures may occur if a contracture crosses over both the metacarpophalangeal (MCPJ) and proximal interphalangeal (PIPJ) joints of one finger. In this situation the extension deficit at one joint can be influenced by the position of the other. This may affect clinical measurements and introduce errors and bias into research using angular deformity as an endpoint. This study reports the dynamism encountered when measuring passive joint extension deficits in pre-operative contractures. Eighty-five digits with a contracture affecting the PIPJ or MCPJ and PIPJ on 72 hands from 70 patients were studied. Seventy-six digits showed dynamism at either the MCPJ or PIPJ (89%). Seventy-four showed dynamism at the PIPJ (87%). The mean dynamism observed was 6° at the MCPJ and 14° at the PIPJ. Previous Dupuytren’s surgery to the finger did not influence the amount of dynamism seen. Dynamism is common and may be a source of error or bias in trials of Dupuytren’s disease treatment. Level of evidence: III Keywords Dynamism, Dupuytren’s contracture, Dupuytren’s disease, goniometry, finger, joint Date received: 28th December 2013; revised: 9th February 2014; accepted: 19th February 2014
Introduction Many studies of surgery for Dupuytren’s disease report ‘recurrence rates’ after treatment, but often without providing a definition of recurrence (Becker and Davis, 2010). Systematic reviews of Dupuytren’s disease have demonstrated no consistent definition of recurrence (Becker and Davis, 2010; Werker et al., 2012). When recurrence is defined, the most common definition is the recurrence of a specific angular deformity. Seventeen variations, such as an angular deformity of 30°, are reported (Ball et al., 2013). Improvement in angular deformity has been the primary endpoint of the two most recent and high-profile randomized controlled trials of Dupuytren’s disease treatment (Hurst et al., 2009; van Rijssen et al., 2006). Return of angular deformity was used to assess recurrence as the primary outcome in the 5-year follow-up of the latter trial (van Rijssen et al., 2012). If a Dupuytren’s contracture spans both the MCPJ and PIPJ, the severity of the passive flexion deformity of one of these joints may be influenced by the position of the other when the measurement is taken through what is referred to as dynamism (Hurst, 2010). Thus, if the metacarpophalangeal joint (MCPJ)
is held in maximal passive flexion, then the flexion deformity at the proximal interphalangeal joint (PIPJ) may be partially or completely relieved. Conversely, if the MCPJ is held in maximal passive extension, then the PIPJ flexion deformity may be exaggerated (Figure 1). To minimize the effect of such dynamism, observers may hold the other joints of the finger in maximum passive flexion when measuring a flexion deformity of a joint. This measures a ‘minimized’ passive extension deficit, rather than the active deficit encountered by the patient, which might be largely due to dynamism.
1Division
of Orthopaedic & Accident Surgery, University of Nottingham & Nottingham University Hospitals NHS Trust, Nottingham, UK 2Division of Academic Rheumatology, University of Nottingham, Nottingham, UK Corresponding author: JN Rodrigues, Division of Orthopaedic & Accident Surgery, University of Nottingham & Nottingham University Hospitals NHS Trust, C-Floor, West Block, Queen’s Medical Centre, Derby Road, Nottingham, NG7 2UH, UK. Email: [email protected]
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Figure 1. Schematic illustration of dynamism. The Dupuytren’s cord (shown in blue) is not elastic and has fixed attachments to the palmar aponeurosis in the palm and flexor sheath in the middle pulp space. (a) Extension of the MCPJ tightens the cord at the PIPJ, pulling it into flexion and generating the ‘worst’ PIPJ angle. Alternatively, passive flexion of the PIPJ relaxes the cord and allows increased extension at the MCPJ, giving the ‘best’ MCPJ angle. (b) Flexion of the MCPJ relaxes the same cord at the PIPJ and allows increased extension, generating the ‘best’ PIPJ angle. Alternatively, passive extension of the PIPJ tightens the cord and pulls the MCPJ into flexion, giving the ‘worst’ MCPJ angle.
Dynamism may also reduce the correlation between passive angles measured by an observer and the patient’s experience of the contracture, as the patient cannot achieve the milder contracture obtained by measuring passive extension angles at the MCPJ and PIPJ separately. Alternatively, active extension can be measured to more accurately represent the patient’s experience of an extension deficit. We are not aware of any reports of the potential impact of dynamism on angular joint measurements. Goniometry in general has good inter- and intra-observer reproducibility when assessed in controlled situations. When performed by hand therapists to measure joint angles in normal digits held in fixed positions by thermoplastic splints, inter-observer reproducibility was reported at 7–9° and intra-observer reproducibility at 4–5° (Ellis and Bruton, 2002). However, if common and significant, dynamism may introduce an important source of bias and error, which could influence reported recurrence rates. This could influence the outcome of studies reporting individual joint angles, but would also be relevant to studies of total passive extension deficit, as in such cases the individual joint angles are measured separately and then added to each other. This study aimed to establish the extent of dynamism on Dupuytren’s contractures affecting PIPJs awaiting surgery (with or without MCPJ involvement).
Methods These data are derived from the baseline data collection from a service evaluation study of early functional recovery following Dupuytren’s disease surgery. Data collection took place between February 2012 and May 2013. The inclusion criteria were patients meeting of all of the following: a) awaiting fasciectomy or dermofasciectomy at a single UK hand surgery service; b) primary or recurrent Dupuytren’s disease of one or more fingers; c) an extension deficit affecting the PIPJ of one of the digits when actively extending this digit; d) a pre-operative assessment clinic appointment scheduled for a date when the primary author (JR) was available to perform the measurements. Exclusion criteria were a) an isolated MCPJ contracture; b) cognitive impairment preventing informed consent; c) refusal of invitation to participate. Contractures that appeared to affect the PIPJ only were still included, as in these cases there may have been MCPJ dynamism within the range of hyperextension, which was not assessed in the study. However, as PIPJs do not typically hyperextend passively, MCPJ only contractures were excluded. Eligible patients who attended a routine orthopaedic preadmission clinic were issued with a letter explaining the project and inviting them to participate on a voluntary basis. A single surgeon assessed all patients who consented to participate. Demographic details, including previous surgery to the finger
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Table 1. Differences between ‘worst’ and ‘best’ angles at PIPJ by digit. Digit
Little Ring Middle Index
Sample size (n = 85) n (%)
Difference of worst – best angles at PIPJ, ° mean (95% CI)
55 (65) 19 (22) 8 (9) 3 (4)
11 (9–14) 20 (12–29) 16 (5–27) 64 (30–99)
involved, were recorded. Goniometry was performed to measure the extension deficits of the MCPJ and PIPJ of all digits that were to undergo surgery. This was initially performed with the other joint of the digit held in maximum passive flexion (thus minimizing the extension deficit measured, giving the ‘best’ measure), and was then repeated with the other joint of the digit in maximum passive extension (thus maximizing the extension deficit measured, giving the ‘worst’ measure). When assessing an MCPJ in which hyperextension was present, this was recorded as 0°, in keeping with the methodology used in previous studies of goniometry in Dupuytren’s disease (JeroschHerold et al., 2011). All measurements were performed using a Baseline® (Fabrication Enterprises Inc, White Plains, New York, USA) stainless steel goniometer, with markings at 5° increments. The single surgeon who performed all measurements used a standardized technique throughout. Analysis was performed using Prism 6.0 for Mac OS X (GraphPad® software, La Jolla, California, USA).
Results Ninety-one patients were considered for participation in this study. Fourteen were excluded because they had MCPJ only contractures and six declined to participate. One was excluded because she had Alzheimer’s disease that prevented informed consent. This left 85 digits on 72 hands from 70 patients who consented to participate. Fifty-five were men (79%) and the mean age was 67 years. The digits studied were predominantly little fingers (Table 1). Thirty-five of 85 digits studied (41%) had PIPJ only contractures. In these 35, the ‘best’ and ‘worst’ MCPJ angles obtained were both within hyperextension. By finger, the proportions of PIPJ only contractures were a) index 0/3 (0%), b) middle 1/8 (13%), c) ring 5/19 (26%), d) little 29/55 (53%), which were significantly different (p = 0.023, Chi-squared test). Seventy-six digits showed dynamism at either the MCPJ or PIPJ (89%). Seventy-four showed dynamism
Table 2. Best and worst angles. Joint
Best angle, ° mean (95% CI)
Worst angle, ° mean (95% CI)
Dynamism, ° mean (95% CI)
MCPJ PIPJ
19 (14–25) 49 (44–54)
25 (19–31) 63 (58–68)
6 (4–7) 14 (11–17)
at the PIPJ (87%), but only 35 (41%) MCPJs exhibited dynamism. Other MCPJs may have had dynamism within the range of hyperextension, which was not captured here. In nine digits there was more than 30° of dynamism at one joint (11%). The mean ‘best’ MCPJ angle was 19° and the mean ‘worst’ MCPJ angle was 25°. The mean range of dynamism for MCPJs was thus 6°, which represented a highly significantly difference between best and worst angles (p < 0.0001, paired t-test). The mean dynamism seen increased to a mean of 9° (95% CI 7–12) when those digits in which both ‘worst’ and ‘best’ MCPJ angles were 0° were excluded (as dynamism within the range of hyperextension might have been present in these digits, but was not assessed in this study). The mean ‘best’ PIPJ angle was 49° and the mean ‘worst’ PIPJ angle was 63°. Thus, the mean dynamism for PIPJs was 14°, which also represented a highly significant difference between best and worst angles (p < 0.0001, paired t-test). The results are shown in Table 2. Twenty-one fingers had undergone previous Dupuytren’s surgery (25%). Fingers that had already had surgery for Dupuytren’s disease had comparable ranges of dynamism to those that had not undergone previous surgery. For the MCPJ, the mean range of dynamism was 5o (95% CI 4–6) for digits that had previously undergone surgery and 6o (95% CI 2–9) for those that had not had previous surgery. For the PIPJ, the mean range of dynamism was 13o (95% CI 10–16) for fingers that had previously undergone surgery and 15o (95% CI 11–18) for those that had not had previous surgery. Results from different digits are presented in Table 1. The difference between ‘worst’ and ‘best’ MCPJ angles did not differ significantly between digits (p = 0.14, one-way analysis of variance [ANOVA]). However, the extent of PIPJ dynamism varied by digit (p < 0.0001, one-way ANOVA). When Tukey’s multiple comparisons test was applied, highly significant differences (p < 0.0001) were seen between the index and all other fingers. The only other significant difference was between the ring and little fingers (Table 3). There was a difference in the proportion of PIPJ-only contractures between the ring and little fingers (ring: 5/19 (26%) vs. little: 29/55 (53%); p = 0.046, Chi-squared test), which may have contributed to this.
169
Rodrigues et al. Table 3. Differences in dynamism at the PIPJ between different digits (mean, 95% CI), significance levels from Tukey’s multiple comparisons test.
Index
Middle, °
Ring, °
Little, °
48 (70–26) p < 0.0001
44 (64–23) p < 0.0001 4 (−9 to 18) NS
53 (72–33) p < 0.0001 5 (17 to −8) NS 8 (18–0) p = 0.042
Middle Ring
Discussion Accurate intra- and inter-observer reproducibility of goniometry measurements taken by therapists have been previously reported (Ellis and Bruton, 2002). However, the study model did not reproduce the clinical situation, as measurements were taken from the fingers of a normal hand that was held in a fixed flexed posture by a thermoplastic splint. Thus, there was no possibility of measurement errors or differences due to dynamism or other patient and contracture factors, and the estimates of reproducibility are probably over optimistic. Dynamism may constitute a source of inadvertent measurement error or systematic bias in clinical trials of Dupuytren’s disease management. If observers are not blinded or are able to recognize the treatment that the patient has received from the scarring on the hand, conscious or subconscious bias may influence the angular measurement. In recent clinical trials of Dupuytren’s disease surgery, goniometric measurements were performed by unblinded surgeons (van Rijssen et al., 2006; 2012). Another recent high profile study defined treatment success as correction of angular deformity at single joint level to less than 5°, with recurrence defined as a subsequent increase in angular deformity of 20° or more (Hurst et al., 2009). The 14° mean range of dynamism at the PIPJ, or even just 6° at the MCPJ demonstrated in the present study, could have markedly altered the proportions of patients classified as successes or failures, or recurrences or no recurrences. In another paper describing late outcome of surgery, recurrence was defined as an increase in total passive extension deficit of 30° (van Rijssen et al., 2012), and dynamism could also have greatly influenced the results and conclusions. In the present study, index fingers showed the most dynamism. However, there were only three index fingers in the series, and so this difference should be interpreted with caution. The clinically important difference in range of motion for collagenase treatment of Dupuytren’s
disease has been estimated at 13.5° (Witthaut et al., 2011). The calculation reported in that study involved composite measurement of active extension and flexion, and thus would include both the MCPJ and PIPJ (Ellis and Bruton, 2002). In our study, the combined MCPJ and PIPJ dynamism was greater than this, at 19–23° (depending on whether or not those MCPJs in hyperextension were excluded). There are limitations to this comparison. ROM involves active flexion and extension, whereas the dynamism assessed here applies to passive measurements. Furthermore, the clinically important difference is context-specific. This value was calculated from a study of collagenase treatment, and it may vary for other treatment modalities. Nevertheless, it suggests that dynamism may give rise to inaccuracy in joint measurement that is clinically relevant. There are limitations to this study. One was that only pre-operative contractures were measured. In contrast, the results of trials consider pre- and postoperative angular deformities. However, 21 of the 85 fingers studied had undergone previous Dupuytren’s disease surgery, and these exhibited similar ranges of dynamism to the others. Thus, we believe our findings can be reasonably extrapolated to postoperative situation. The goniometer used only had 5° increments, which might be considered a source of inaccuracy. However, intra- and inter-observer reproducibility of goniometry has been reported at 4–5° and 7–9°, respectively, when studied in a highly controlled setting (Ellis and Bruton, 2002). Therefore, measuring angles to the nearest degree or two, rather than the nearest 5°, is probably not appropriate. The position of the carpometacarpal and distal interphalangeal joints (DIPJs) were not controlled during this study, and it is possible that their position may also influence dynamism. To be the case, there would need to be mobility of the palmar aponeurosis proximally and extension of the cord across the DIPJ distally. The latter is unusual, and most Dupuytren’s cords that cross the PIPJ are firmly attached to the flexor sheath over the middle phalanx, proximal to the DIPJ. Instead, Dupuytren’s disease may cause a Boutonnière deformity, with pathological hyperextension of the DIPJ. This might complicate the study of dynamism at the DIPJ. We believe that the standardization of measurements in this study, involving the same surgeon throughout, will have minimized this to allow study of dynamism at the MCPJ and PIPJ. Future study could investigate any influence of the position of these other joints, but it would be difficult for a single observer to passively manipulate the position of four joints within a ray at the same time. The results of the present study may represent the extreme range of dynamism, given that the ‘worst’
170 angles were obtained by passively manipulating the digit to exaggerate a contracture at a particular joint. This strategy was intentional, as the aim was to establish the maximum amount of dynamism achievable. However, it is unlikely that the full extent of dynamism would be encountered in a trial, unless bias was very marked, or some observers had been trained to measure angular deformities in a manner which, through dynamism, either maximized or minimized the angular deformity. Nonetheless, this work demonstrates just how large an impact dynamism might have on individual joint measurements. Even if only half the range of dynamism demonstrated in the present study actually occurred, altering nine out of 10 PIPJ measurements in a trial by a mean of 7° might shift the balance of success/failure of treatment or later recurrence/no recurrence significantly. The effect of dynamism on post-operative outcome assessment should be formally studied. In the meantime, reporting active (rather than passive) extension deficit might minimize its impact. Alternatively, a patient-reported outcome measure could be used as the primary outcome measure. This would avoid the impact of dynamism on trial outcome data, may provide a more meaningful description of hand function and the benefit of surgery, and align trial design with the growing use and study of patient-reported outcome data across in the UK National Health Service and other countries (Darzi, 2008; Mokkink et al., 2010). Acknowledgement JNR received educational support from a scholarship from the National Institute for Health and Care Excellence (NICE) during this project.
Conflict of interests None declared.
Ethical approval This study was a minor element of a larger service evaluation project studying treatment outcome in Dupuytren’s disease. In keeping with UK National Research Ethics Service guidance, it is exempt from ethical approval. Nottingham University Hospitals NHS Trust guidance for the conduct of service evaluation projects was followed.
Funding This work was supported by a British Society for Surgery of the Hand Research Fellowship, Nottingham Hospitals Charity and Nottingham Orthopaedic Walk.
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