Abstract
Purpose
Clinicians routinely use the Eaton-Glickel radiographic classification to stage severity of thumb carpometacarpal osteoarthritis (CMC OA). Our purpose was to evaluate correlations between baseline radiographic stages and prospectively collected patient-reported outcome measures (PROMs) for CMC OA.
Methods
This is a retrospective review of prospectively collected data from a larger observational study of patients aged 35–85 years with newly symptomatic thumb CMC OA. Patients with bilateral presentation complete PROMs for each side. We identified patients with adequate radiographs available for review and who had completed baseline PROMs. PROMs were collected electronically and included the Brief Michigan Hand Questionnaire and visual analog/numerical rating scales regarding pain as well as Patient-Reported Outcomes Measurement Information System Pain Interference v1.1 and Global Health modules. We recorded participants’ demographics, medical and surgical history, prior treatments, and PROM scores at initial presentation. A medical student was first taught by a fellowship-trained hand surgeon on Eaton-Glickel radiographic staging. They each then independently staged the first 40 series of radiographs. After establishing adequate reliability, the student staged the remaining available radiographic series. We used Cohen’s Kappa analyses to determine intrarater reliability and interrater reliability. We used Spearman's rho to assess correlations between PROM scores and radiographic stages.
Results
Adequate radiographs and baseline PROMs were retrievable for 85 patients (64 unilateral, 21 bilateral) for a total of 106 series of radiographs. The student's intrarater reliability was moderate, whereas the surgeon’s was substantial. Their interrater reliabilities were moderate (all P < .05). We found no significant correlations between any PROMs and radiographic staging.
Conclusions
Our study adds to growing evidence that radiographic severity for thumb CMC OA does not correlate with validated PROMs. It is becoming clearer that objective measures of CMC OA severity do not fully capture the way patients experience this condition.
Type of study/level of evidence
Therapeutic IV.
Key words: Osteoarthritis, Patient-reported outcome measures, Radiographic classification, Thumb carpometacarpal, Thumb carpometacarpal osteoarthritis
Thumb carpometacarpal osteoarthritis (CMC OA) changes are radiographically ubiquitous with advancing age.1,2 Approximately one in five people present for CMC OA care during their lifetime, with females presenting 3–4 times more frequently.3, 4, 5 Clinicians diagnose symptomatic CMC OA predominantly by evaluating for a discrete location of pain and tenderness or through physical examination maneuvers such as the grind test.6 Providers commonly also use radiographs in the course of care.7 There is substantial variability in how CMC OA does or does not affect people. Some experience debilitating effects, whereas others remain asymptomatic or manage their symptoms well despite extensive radiographic signs of the disease.8,9 As such, radiographic severity traditionally does not correlate with patient pain or function, or even whether they will present for care.5,9,10
Two main variations of the most widely used CMC OA radiographic classification are the original Eaton-Littler system published in 1973 and the modified Eaton-Littler, or Eaton-Glickel, system reported in 1987.11 We refer to the latter as the Eaton-Glickel classification for the remainder of this manuscript. The differences between the two systems can be summarized as follows: (1) the inclusion and extent of carpometacarpal (CMC) subluxation, (2) the stage at which subchondral sclerosis is introduced, (3) the delineation of degrees of joint space narrowing, and (4) the characterization of stage IV (Table 1).
Table 1.
The Criteria for the Stages of the Original Eaton-Littler and the Modified Eaton-Littler (Eaton-Glickel) Classifications
| Stage | Original Eaton-Littler (1973) | Modified Eaton-Littler or Eaton-Glickel (1987) |
|---|---|---|
| I | Slight joint widening, <1/3 subluxation, and normal articular contours | Normal or slight joint widening |
| II | May be at least 1/3 subluxation and bone/calcific fragments <2 mm | Slight joint narrowing, minimal subchondral sclerosis, and osteophytes or loose bodies ≤2 mm |
| III | >1/3 subluxation, fragments >2 mm and slight joint narrowing | Markedly narrowed or obliterated joint space, cystic changes, sclerotic bone, varying degrees of dorsal subluxation, osteophytes or loose bodies >2 mm |
| IV | Advanced degenerative changes, major subluxation, very narrow joint space, subchondral cystic and sclerotic changes, trapezial osteophytes, and erosion of the dorsoradial facet | Stage III degeneration + scaphotrapezial joint degeneration (narrowing with sclerotic and cystic changes) |
In this study, we sought to determine whether there were any correlations between Eaton-Glickel radiographic stages and our prospectively collected, unique, validated, patient-reported outcome measures (PROMs) at the time of initial presentation for thumb CMC OA care. We hypothesized there would be no significant correlations between baseline radiographic stages and these PROMs. We also intended to further evaluate the intrarater reliability and interrater reliability of the Eaton-Glickel classification, with prior researchers typically reporting these to be in the moderate range.12
Materials and Methods
We secured institutional review board approval prior to data collection, and all participating patients provided written informed consent. We conducted a retrospective, cross-sectional review of consecutive patients enrolled in our ongoing prospective nonsurgical thumb CMC OA study. For the prospective study, all patients aged 35–85 presenting with symptomatic thumb CMC OA and initiating nonsurgical care were eligible for enrollment. Patients who had CMC OA surgery at any time or nonsurgical treatments within the past year were excluded. Those who had carpal tunnel syndrome were also excluded because of confounding factors with our chosen PROMs. Otherwise, patients were always reminded to focus on only their thumb CMC before completing PROMs. Participating patients completed baseline forms encompassing demographics; medical, surgical, and social history; and a CMC history form. PROMs included the Brief Michigan Hand Questionnaire and 11-point visual analog/numerical rating scales (VA/NRS) for current pain, pain with activities, and typical worst pain. Participants also completed Patient-Reported Outcomes Measurement Information System Pain Interference v1.1 as well as Global Health, from which we captured Global Mental Health, Global Physical Health, and calculated Estimated Utility Score. Patients with a bilateral presentation completed separate PROMs for each side.
For this retrospective review, we only included patients from our prospective study database who had adequate posteroanterior (PA) and lateral radiographs for the thumb CMC. Patients with poor-quality radiographs were excluded, as were those whose radiographs were taken more than 1 year before or after the enrollment date because structural deterioration has been found to take longer than 1 year to progress on radiographic imaging.13 All patients with radiographic scaphotrapezial degeneration also had CMC degeneration, ie, we did not include any patients with primary scaphotrapeziotrapezoidal degeneration without CMC degeneration.
An orthopedic hand surgeon with the Subspecialty Certificate in Surgery of the Hand from our center taught a medical student researcher how to read and grade thumb CMC OA radiographs. The medical student also studied relevant CMC radiographic literature. After several rounds of learning, reviewing, and establishing an adequate baseline understanding and agreement, the medical student and hand surgeon began independent radiographic staging using the Eaton-Glickel classification. We chose this system considering variability of CMC joint subluxation timing and degree relative to other changes, and its more recent widespread clinical use including for our providers’ practices.11,14
Intrarater reliability and interrater reliability were assessed to establish sufficient accuracy for the medical student’s radiographic interpretations using a sample size of 40.15 To determine interrater reliability, the hand surgeon and medical student independently staged the first 40 series of radiographs included in the study. To assess intrarater reliability, they repeated the radiographic staging for these same patients at least 1 week later. Once adequate reliability was confirmed, the student staged the remaining series of radiographs. After determining reliability, the student and surgeon were unblinded to each other’s stagings and any discrepancies for the first 40 series of radiographs were resolved through consensus before inclusion in the final set of stagings used for analyses with PROMs. In cases of uncertainty for the remaining radiographic series, the student consulted with the surgeon to reach a final consensus classification for inclusion in the final set of stagings used for analyses.
We used Cohen's Kappa coefficient to measure interrater reliability and intrarater reliability for radiographic staging and determined the statistical significance of observed agreements. We employed Spearman's rank correlation coefficient/Spearman’s rho to assess the relationship between baseline PROMs and the final set of radiographic stagings. We categorized the strength of these associations based on rho values as: very weak (rho < 0.2), weak (rho = 0.20–0.39), moderate (rho = 0.40–0.59), strong (rho = 0.6–0.79), and very strong (rho = 0.80–1.0).16 We also compared group-level PROMs scores for patients across radiographic stages using one-way analysis of variance.
Results
We identified 130 study participants in the database who had completed our PROMs and had available radiographs. Among these, 30 patients had bilateral involvement at the time of presentation, resulting in a total of 160 series of radiographs for initial review. After applying criteria for image quality and collection date, we excluded 54 series of radiographs for a final sample of 106 series. Of these, 64 series (60%) were from patients with a unilateral presentation, and 42 (40%) were from patients with a bilateral presentation, for a total of 85 patients. For the 106 series of radiographs, 76% were from women patients (N = 80), and 24% were from men patients (N = 26). The patient median age was 61 years (range: 41–80).
Intrarater reliability was moderate for the medical student and substantial for the hand surgeon. We found moderate interrater reliabilities for the radiographic staging of the first 40 series of radiographs at both time points. All reliability assessments revealed statistically significant agreement (P < .05) (Table 2). Of the final set of 106 series of radiographs, 8% were classified as Eaton-Glickel stage I (N = 8), 41% as stage II (N = 43), 40% as stage III (N = 42), and 12% as stage IV (N = 13). All correlations between Eaton-Glickel staging and PROMs were weak or very weak and not statistically significant (P > .05) (Table 3). Additionally, group-level scores for all PROMs did not have statistically significant differences across Eaton-Glickel stages (P > .05) (Table 4).
Table 2.
Intrarater Reliability and Interrater Reliability for the Eaton-Glickel Classification for the Medical Student and Hand Surgeon
| Reliability Rating | Agreement | Kappa Coefficient | Standard Error | P Value | Interpretation |
|---|---|---|---|---|---|
| Medical student Intrarater |
63% | >0.40 | 0.11 | <.05∗ | Moderate agreement |
| Hand surgeon Intrarater |
83% | 0.71 | 0.12 | <.05∗ | Substantial agreement |
| Interrater First round |
73% | 0.56 | 0.11 | <.05∗ | Moderate agreement |
| Interrater Second round |
73% | 0.54 | 0.12 | <.05∗ | Moderate agreement |
The percentage of agreement complements the Kappa coefficient by providing an additional measure of consistency between assessments. Kappa value interpretations: 0.01–0.20 poor agreement; >0.20–0.40 fair agreement, >0.40–0.60 moderate agreement, >0.60–0.80 substantial agreement, and >0.80–1.00 almost perfect agreement.
Statistically significant agreement.
Table 3.
Correlations between Eaton-Glickel Classification Staging and Baseline PROMs by Spearman’s Rho
| Brief Michigan Hand Questionnaire | Current Pain Severity | Pain Severity with Activities | Typical Worst Pain Severity | Patient-Reported Outcomes Measurement Information System Pain Interference | Estimated Utility Score | Global Mental Health | Global Physical Health | |
|---|---|---|---|---|---|---|---|---|
| Correlation with Eaton-Glickel Staging (rho) | −0.24 | 0.11 | 0.21 | −0.02 | 0.20 | −0.17 | −0.08 | −0.15 |
| P Value | >.05 | >.05 | >.05 | >.05 | >.05 | >.05 | >.05 | >.05 |
Please note very weak (rho < 0.2), weak (rho = 0.20–0.39), moderate (rho = 0.40–0.59), strong (rho = 0.6–0.79), and very strong (rho = 0.80–1.0).
Table 4.
Results of One-Way Analysis of Variance Tests Comparing Mean PROMs Scores Across Eaton-Glickel Stages
| Eaton-Glickel Stage | Brief Michigan Hand Questionnaire | Current Pain Severity | Pain Severity with Activities | Typical Worst Pain Severity | Patient-Reported Outcomes Measurement Information System Pain Interference | Estimated Utility Score | Global Mental Health | Global Physical Health |
|---|---|---|---|---|---|---|---|---|
| I (N = 8) | 66 | 3 | 4 | 7 | 57 | 0.73 | 49.7 | 49.0 |
| II (N = 43) | 69 | 4 | 5 | 7 | 55 | 0.73 | 51.8 | 48.2 |
| III (N = 42) | 61 | 4 | 6 | 7 | 58 | 0.71 | 51.4 | 46.6 |
| IV (N = 13) | 58 | 5 | 6 | 7 | 58 | 0.68 | 48.2 | 44.9 |
| P Value | >.05 | >.05 | >.05 | >.05 | >.05 | >.05 | >.05 | >0.05 |
Discussion
We used a set of prospectively collected baseline measures to add to the growing body of evidence indicating a lack of substantial association between thumb CMC OA radiographic severity and PROMs. Our study is unique in our relatively large sample size, and we prospectively collected PROMs with better CMC OA-specific validity. Additionally, patients were clearly instructed to report PROMs only as relating to their thumb CMC(s) with a goal of improving reporting accuracy.
Hoffler et al10 investigated the relationship between CMC OA radiographic stages and the Quick Disabilities of the Arm, Shoulder, and Hand (qDASH) and 12-Item Short Form Survey (SF-12) PROMs. With their cohort of 62 patients, they found no substantial correlations between radiographic staging and these PROMs.10 The qDASH is one of the most widely used PROMs.17 However, it is influenced by shoulder and elbow function, and thus may not be as specific for the functional status of patients with CMC OA. The Brief Michigan Hand Questionnaire, which we used, is specifically validated for CMC OA and has shown excellent test–retest reliability and internal consistency.17, 18, 19
Garcia-Lopez et al20 also observed no correlation between Eaton-Glickel staging and a selection of PROMs (Patient-Reported Outcomes Measurement Information System UE, Australian Canadian Osteoarthritis Hand Index [AUSCAN], and Patient-Rated Wrist/Hand Evaluation [PRWHE]) in a study involving 56 patients with varying degrees of CMC arthritis. Weinstock-Zlotnick et al21 conducted a pilot study exploring the link between radiographic severity of CMC arthritis and hand function using a different set of PROMs. Their study involved nine cases with radiographic evidence of the disease and controls without it. They found no significant correlation between Eaton-Glickel stage and their PROMs, except for the DASH, which showed a strong correlation (ρ = 0.68). However, these results should be interpreted with caution given the sample size. Additionally, Haugen et al22 found weak associations between the Kellgren-Lawrence radiographic classification of CMC OA and the AUSCAN PROM in a study of 190 patients.
Contrasting our findings and those of others, Dahaghin et al5 identified a modest association between pain and radiographic severity of CMC OA using the Kellgren-Lawrence classification in a large cross-sectional study (n = 3,906). Additionally, one study tracked a cohort of 91 patients experiencing symptomatic CMC OA with limited structural disease (Eaton-Glickel stage 0–1).23 They used the AUSCAN and PRWHE PROMs and discovered that those experiencing a one-grade advancement in radiographic severity based on the Eaton-Glickel classification had slightly elevated pain scores at 36 months compared to their baseline. However, there were no notable differences in any scores between individuals with radiographic progression and those without. Although these findings do not directly contradict those of our study and others, they contribute depth to the discourse concerning the use of radiographic evidence in the management of CMC OA over time. It further suggests that any potential correlations between symptom or dysfunction severity and radiographic disease progression are likely to have a relatively small effect size, if present.
Our findings and those of others lend support to only using the Eaton-Glickel classification as a relatively objective and reliable method to report the radiographic interpretation of thumb CMC OA. We favor avoiding routine use of radiographs for the diagnosis and nonsurgical management of CMC OA whenever the clinical presentation is clear.24,25,26,27
Our intrarater reliability and interrater reliability measures for the Eaton-Glickel classification were within the ranges of those reported by others.12,24,26,27 This confirmed adequate consistency of our radiographic interpretations for the main purpose of our study. There has been inconsistency in other authors’ reports regarding which version of the classification, or what further modifications, they used for their studies or reviews. It is possible that a more reliable or detailed radiographic system for CMC OA could yield better correlations with CMC clinical measures for pain and function. Yet, it is clear that clinical effects of CMC OA are influenced more by factors beyond radiographic extent. For example, patients’ illness perceptions, coping strategies, and other psychosocial elements consistently do statistically significantly correlate with CMC pain, self-reported disability, and the likelihood of advancing to surgical care.6,28,29 Thumb pain and disabilities associated with CMC OA have shown complex associations with both demographic and clinical factors, which should be taken into consideration by providers.9
One limitation of our study is its retrospective nature, including the lack of a priori standardization of techniques for performing the radiographs. This could have influenced our radiographic classifications. Additionally, there may be significant correlations between Eaton-Glickel radiographic stage and PROMs that we were unable to detect with our sample sizes. Furthermore, most of the radiographic interpretations were made by a medical student. However, our intrarater reliability and interrater reliability ratings for the Eaton-Glickel classification were similar to those reported by others. This alignment suggests that our findings are relevant to practical usage of this system and any correlations with our chosen PROMs. Parenthetically, we also found no significant correlations across the surgeon’s 40 radiographic stagings and any PROMs (P > .05).
In conclusion, this study contributes further valuable insights into the complexity of diagnosing and managing CMC OA. The general lack of substantial correlations between CMC radiographic severity and PROMs underscores the need for nuanced approaches for addressing this pervasive condition. We suggest that routine radiographs are not required to initiate or guide nonsurgical management of patients with symptomatic thumb CMC OA when the clinical diagnosis is clear.
Disclaimer
Given his role as Deputy Editor-in-Chief of The Journal of Hand Surgery Global Online, Dr. Giladi had no involvement in the peer-review of this article and has no access to information regarding its peer-review. Full responsibility for the editorial process for this article was delegated to John R. Fowler, MD.
Conflicts of Interest
No benefits in any form have been received or will be received related directly to this article.
Acknowledgments
This study was funded by the American Foundation for Surgery of the Hand clinical research grant #3716. We thank Ashley Bartee, BS, research associate, and Carly Kingston, BS, clinical research coordinator II, for their coordination and administration of this study. We also thank Kelsey Brannon, BA, medical editor, for her review and preparation of the submitted manuscript.
References
- 1.Becker S.J.E., Briet J.P., Hageman M.G.I.S., Ring D. Death, taxes, and trapeziometacarpal arthrosis. Clin Orthop Relat Res. 2013;471(12):3738–3744. doi: 10.1007/s11999-013-3243-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Sodha S., Ring D., Zurakowski D., Jupiter J.B. Prevalence of osteoarthrosis of the trapeziometacarpal joint. J Bone Joint Surg Am. 2005;87(12):2614–2618. doi: 10.2106/JBJS.E.00104. [DOI] [PubMed] [Google Scholar]
- 3.Jónsson H., Valtýsdóttir S.T., Kjartansson O., Brekkan A. Hypermobility associated with osteoarthritis of the thumb base: a clinical and radiological subset of hand osteoarthritis. Ann Rheum Dis. 1996;55(8):540–543. doi: 10.1136/ard.55.8.540. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Gavile C.M., Kazmers N.H., Novak K.A., et al. Familial clustering and genetic analysis of severe thumb carpometacarpal joint osteoarthritis in a large statewide cohort. J Hand Surg Am. 2022;47(10):923–933. doi: 10.1016/j.jhsa.2022.08.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Dahaghin S., Bierma-Zeinstra S.M., Ginai A.Z., Pols H.A., Hazes J.M., Koes B.W. Prevalence and pattern of radiographic hand osteoarthritis and association with pain and disability (the Rotterdam study) Ann Rheum Dis. 2005;64(5):682–687. doi: 10.1136/ard.2004.023564. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Choa R.M., Parvizi N., Giele H.P. A prospective case-control study to compare the sensitivity and specificity of the grind and traction-shift (subluxation-relocation) clinical tests in osteoarthritis of the thumb carpometacarpal joint. J Hand Surg Eur Vol. 2014;39(3):282–285. doi: 10.1177/1753193413508714. [DOI] [PubMed] [Google Scholar]
- 7.Van Heest A.E., Kallemeier P. Thumb carpal metacarpal arthritis. J Am Acad Orthop Surg. 2008;16(3):140–151. doi: 10.5435/00124635-200803000-00005. [DOI] [PubMed] [Google Scholar]
- 8.Haara M.M., Heliövaara M., Kröger H., et al. Osteoarthritis in the carpometacarpal joint of the thumb. Prevalence and associations with disability and mortality. J Bone Joint Surg Am. 2004;86(7):1452–1457. doi: 10.2106/00004623-200407000-00013. [DOI] [PubMed] [Google Scholar]
- 9.Wilkens S.C., Tarabochia M.A., Ring D., Chen N.C. Factors associated with radiographic trapeziometacarpal arthrosis in patients not seeking care for this condition. Hand (N Y) 2019;14(3):364–370. doi: 10.1177/1558944717732064. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Hoffler C.E.,I.I., Matzon J.L., Lutsky K.F., Kim N., Beredjiklian P.K. Radiographic stage does not correlate with symptom severity in thumb basilar joint osteoarthritis. J Am Acad Orthop Surg. 2015;23(12):778–782. doi: 10.5435/JAAOS-D-15-00329. [DOI] [PubMed] [Google Scholar]
- 11.Eaton R.G., Glickel S.Z. Trapeziometacarpal osteoarthritis. Staging as a rationale for treatment. Hand Clin. 1987;3(4):455–471. [PubMed] [Google Scholar]
- 12.Berger A.J., Momeni A., Ladd A.L. Intra- and interobserver reliability of the Eaton classification for trapeziometacarpal arthritis: a systematic review. Clin Orthop Relat Res. 2014;472(4):1155–1159. doi: 10.1007/s11999-013-3208-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Botha-Scheepers S., Riyazi N., Watt I., et al. Progression of hand osteoarthritis over 2 years: a clinical and radiological follow-up study. Ann Rheum Dis. 2009;68(8):1260–1264. doi: 10.1136/ard.2008.087981. [DOI] [PubMed] [Google Scholar]
- 14.Halilaj E., Rainbow M.J., Got C., et al. In vivo kinematics of the thumb carpometacarpal joint during three isometric functional tasks. Clin Orthop Relat Res. 2014;472(4):1114–1122. doi: 10.1007/s11999-013-3063-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Donner A., Eliasziw M. Sample size requirements for reliability studies. Statistics in Medicine. 1987;6(4):441–448. doi: 10.1002/sim.4780060404. [DOI] [PubMed] [Google Scholar]
- 16.Evans J.D. Thomson Brooks/Cole Publishing Co; 1996. Straightforward statistics for the behavioral sciences. [Google Scholar]
- 17.Marks M., Audigé L., Herren D.B., Schindele S., Nelissen R.G.H.H., Vliet Vlieland T.P.M. Measurement properties of the German Michigan Hand Outcomes Questionnaire in patients with trapeziometacarpal osteoarthritis. Arthritis Care Res (Hoboken) 2014;66(2):245–252. doi: 10.1002/acr.22124. [DOI] [PubMed] [Google Scholar]
- 18.Chung K.C., Pillsbury M.S., Walters M.R., Hayward R.A. Reliability and validity testing of the Michigan Hand Outcomes Questionnaire. J Hand Surg Am. 1998;23(4):575–587. doi: 10.1016/S0363-5023(98)80042-7. [DOI] [PubMed] [Google Scholar]
- 19.Waljee J.F., Kim H.M., Burns P.B., Chung K.C. Development of a brief, 12-item version of the Michigan Hand Questionnaire. Plast Reconstr Surg. 2011;128(1):208–220. doi: 10.1097/PRS.0b013e318218fc51. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Garcia-Lopez E., Moore D.C., Kenney D.E., Ladd A.L., Weiss A.C., Crisco J.J. Evaluation of the PROMIS upper extremity against validated patient-reported outcomes in patients with early carpometacarpal osteoarthritis. J Hand Surg Am. 2022;47(7):621–628. doi: 10.1016/j.jhsa.2022.03.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Weinstock-Zlotnick G., Lin B., Nwawka O.K. Clinical assessments of hand function in first carpometacarpal osteoarthritis do not appear to correlate with radiographic findings. HSS J. 2019;15(3):269–275. doi: 10.1007/s11420-019-09705-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Haugen I.K., Slatkowsky-Christensen B., Bøyesen P., van der Heijde D., Kvien T.K. Cross-sectional and longitudinal associations between radiographic features and measures of pain and physical function in hand osteoarthritis. Osteoarthritis Cartilage. 2013;21(9):1191–1198. doi: 10.1016/j.joca.2013.04.004. [DOI] [PubMed] [Google Scholar]
- 23.Gil J.A., Kleiner J., McQuillan T.J., et al. The association of AUSCAN and PRWHE patient-reported outcome measures with radiographic progression of early thumb carpometacarpal arthritis at 36-month follow-up is limited to subtle changes in the pain subscale. Hand (N Y) 2022;17(2):354–360. doi: 10.1177/1558944720928489. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.McHugh M.L. Interrater reliability: the kappa statistic. Biochem Med (Zagreb) 2012;22(3):276–282. [PMC free article] [PubMed] [Google Scholar]
- 25.Becker S.J.E., Makarawung D.J.S., Spit S.A., King J.D., Ring D. Disability in patients with trapeziometacarpal joint arthrosis: incidental versus presenting diagnosis. J Hand Surg Am. 2014;39(10):2009–2015.e8. doi: 10.1016/j.jhsa.2014.07.009. [DOI] [PubMed] [Google Scholar]
- 26.Spaans A.J., van Laarhoven C.M., Schuurman A.H., van Minnen L.P. Interobserver agreement of the Eaton-Littler classification system and treatment strategy of thumb carpometacarpal joint osteoarthritis. J Hand Surg Am. 2011;36(9):1467–1470. doi: 10.1016/j.jhsa.2011.06.017. [DOI] [PubMed] [Google Scholar]
- 27.Kennedy C.D., Manske M.C., Huang J.I. Classifications in brief: the eaton-littler classification of thumb carpometacarpal joint arthrosis. Clin Orthop Relat Res. 2016;474(12):2729–2733. doi: 10.1007/s11999-016-4864-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Lozano-Calderon S.A., Souer J.S., Jupiter J.B., Ring D. Psychological differences between patients that elect operative or nonoperative treatment for trapeziometacarpal joint arthrosis. Hand (N Y) 2008;3(3):271–275. doi: 10.1007/s11552-008-9098-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Wouters R.M., Vranceanu A.M., Slijper H.P., et al. Patients with thumb-base osteoarthritis scheduled for surgery have more symptoms, worse psychological profile, and higher expectations than nonsurgical counterparts: a large cohort analysis. Clin Orthop Relat Res. 2019;477(12):2735–2746. doi: 10.1097/CORR.0000000000000897. [DOI] [PMC free article] [PubMed] [Google Scholar]