Effect of Handedness on Patient-Reported Outcomes After Operative Treatment of CMC Arthritis

Abstract

Background: The purpose of this study is to determine the relationship between hand dominance and patient-reported outcomes (PROs) after operative treatment for carpometacarpal (CMC) arthritis. We hypothesized that hand dominance is not correlated with PROs. Methods: All patients who underwent primary operative treatment for end-stage CMC arthritis at a single healthcare system between April 2018 and December 2022 were eligible for this study. Our exclusion criteria included concomitant procedures, revision operations, and patients without PROs at baseline or any postoperative timepoint. Retrospective review of each patient’s chart for demographics, surgical characteristics, and PROs was conducted. Results: A total of 174 patients were included in this study; of those, 123 (70.7%) were women and 88 (50.6%) had operations on their dominant hand. There was no difference in age, tourniquet time, surgical procedure, primary surgeon, type of anesthetic, or sex distribution between the 2 cohorts. There were no significant differences in baseline patient-rated wrist/hand evaluation (PRWHE) or single assessment numeric evaluation (SANE) between the 2 cohorts. The average 6-month change in PRWHE was -44.5 ± 22.6 for those with operations on their dominant hand versus -43.8 ± 23.4 for the cohort that received operations on their nondominant hand (P = .854). Average change in SANE score did not differ significantly between groups, with dominant-operative patients averaging an increase of 37.5 ± 30.6 versus 33.1 ± 32.9 in their nondominant-operative counterparts. Conclusions: This study reveals no significant difference in PROs at any time point between patients who received CMC arthroplasty on their dominant versus nondominant hand. Surgeons should counsel patients to expect similar outcomes regardless of hand dominance after operation.

Introduction

Osteoarthritis (OA) is an increasingly common condition that appears in the hands more often than any other joint.^1,2 Of the hand OA subtypes, thumb carpometacarpal (CMC) arthritis is among the most common given the thumb’s high usage. ³ Although sometimes asymptomatic, thumb CMC arthritis can present as progressive pain and weakness leading to decreased functionality. ⁴ Carpometacarpal arthritis presents more often in women than men but has the highest prevalence in elderly populations. ⁵ When end-stage CMC arthritis is refractory to nonoperative measures, arthroplasty surgery is favored to restore joint stability. ⁶

Patient-reported outcomes (PROs) measure function, pain, and patient satisfaction and are useful for informing what changes will be noticeable to the patient during their course of recovery. Current research has shown minimal effect of hand dominance on Disabilities of the Arm, Shoulder and Hand (DASH) scores in cases involving the CMC joint.^{7 -9} Still, there remains a paucity of research on how PROs are affected by hand dominance following thumb CMC arthroplasty. Other upper extremity arthroplasty operations, including total shoulder arthroplasty, have shown no significant difference of handedness on surgical outcomes,^{9 -11} but results may differ according to the joint involved.

The purpose of this study is to determine the relationship between postoperative PROs after operative treatment for CMC arthritis between patients who had operations on their dominant hand and those who had operations on the nondominant hand. Patient-reported outcomes were measured using both the patient-rated wrist/hand evaluation (PRWHE) and the single assessment numeric evaluation (SANE) at each of the 3 postoperative timepoints (6 weeks, 3 months, and 6 months). We hypothesized that there would be no difference in PROs based on hand dominance at any timepoint.

Materials and Methods

This retrospective case series was approved by the institutional review board in 2024. All patients who underwent primary operative management of thumb CMC arthritis between April 1, 2018, and December 31, 2022, at a large metropolitan orthopedic center with an affiliated orthopedic residency program were identified using the institutional PRO database and eligible for inclusion in this study. Exclusions comprised incomplete PROs at any study timepoint (ie, baseline, 6 weeks, 3 months, and 6 months), index revision operations, and concomitant ipsilateral procedures (Supplemental Figure 1).

Patient demographics and pertinent characteristics collected from the electronic medical record included age, sex, smoking status, and hand dominance. Surgical data, including operative time, operating surgeon, surgical technique, and mode of anesthetic, were procured from operative reports. Patient-reported outcomes were collected prospectively at baseline (preoperative), 6 weeks, 3 months, and 6 months and stored in a Health Insurance Portability and Accountability Act–compliant database until being used for the present study. Patient-reported outcomes of interest included the PRWHE and the SANE. The minimum clinically important difference (MCID) for PRWHE was calculated at each follow-up timepoint for interpretation of clinical significance. Anchor-based methodology was used, and the MCID was anchored to a 1-point increase in the Patient-Reported Outcomes Measurement Information System Global-10 physical health question, “In general, how would you rate your physical health?”

Statistical analysis was performed using Intellectus Statistics (Clearwater, Florida). Descriptive analyses included means and standard deviations for scale variables, and counts and frequencies for categorical variables. Statistical significance was set at an α value of P ≤ .05. Independent-sample t tests, Mann-Whitney U, χ², and Fisher exact tests were used to determine intercohort differences. Paired t tests were used to identify differences in PRO at different timepoints.

Results

A total of 174 patients were identified for analysis (Table 1). Most patients were women (70.7%) and right-hand dominant (84.5%). Eighty-eight patients (50.6%) had operations on their dominant hand. The average patient age was 63.6 ± 7.3 years at the time of surgery. Ten patients (5.8%) reported current tobacco use. A total of 144 patients (82.8%) received suture suspensionplasty, 21 patients (12.1%) underwent InternalBraceplasty, and 9 patients (5.2%) had ligament reconstruction and tendon interposition for operative treatment of their CMC arthritis.

Table 1.

Overall Patient Demographics (N = 174).

Variable	Value
Age, y	63.6 ± 7.3
Sex
Male	51 (29.3%)
Female	123 (70.7%)
Smoking status
Never	101 (58.1%)
Former	63 (36.2%)
Current	10 (5.8%)
Operation on dominant hand
Yes	88 (50.6%)
No	86 (49.4%)
Mode of anesthetic
Supraclavicular nerve block	120 (69.0%)
Interscalene block	28 (16.1%)
MAC plus block	13 (7.5%)
General	9 (5.2%)
MAC & local	4 (2.3%)
Procedural technique
Suture suspensionplasty	144 (82.8%)
InternalBraceplasty	21 (12.1%)
LRTI	9 (5.2%)

Note. Continuous variables are presented as mean ± SD. Categorical variables are presented as N (%). MAC = monitored anesthesia care; LRTI = ligament reconstruction & tendon interposition.

At baseline, the overall average patient PRWHE score was 62.2 ± 18.4. At the 6-week and 3-month follow-ups, scores improved by 17.1 ± 24.1 and 30.5 ± 23.2, respectively (Figure 1 & Table 2). The final average PRWHE score was 18.0 ± 17.1 at the 6-month timepoint. The 6-week, 3-month, and 6-month MCID were calculated to be 13.8, 31.7, and 40.5, respectively. Ninety-four patients (54.0%) met the calculated MCID at the 6-week timepoint, which decreased to 77 patients (44.3%) who met the calculated MCID at the 3-month timepoint. At the final 6-month follow-up, 102 patients (58.6%) met the calculated MCID. The overall average patient SANE score was 43.8 ± 21.9 at baseline. In this scale, scores increased by 9.4 ± 29.8 at the 6-week timepoint and 24.5 ± 29.6 at the 3-month timepoint. The final average SANE score was 79.1 ± 24.7 at the 6-month follow-up timepoint.

Figure 1.

Line plot of SANE and PRWHE at baseline, 6 weeks, 3 months, and 6 months postoperatively split by operation on dominant or nondominant hand. SANE = single assessment numeric evaluation; PRWHE = patient-rated wrist/hand evaluation.

Table 2.

Patient Demographics for Operative Hand Dominance Cohorts (N = 174).

Variable	Dominant, n = 88	Nondominant, n = 86	P value
Age, y	64.1 ± 7.5	63.1 ± 7.2	.349
Sex			.550
Male	24 (27.3%)	27 (31.4%)
Female	64 (72.7%)	59 (68.6%)
Hand dominance			.567
Right	73 (83.0%)	74 (86.1%)
Left	13 (14.8%)	12 (14.0%)
Both	2 (2.3%)	0 (0.0%)
PRWHE
Baseline	62.5 ± 9.6	61.9 ± 17.1	.842
6 weeks	43.9 ± 19.1	46.3 ± 19.6	.422
3 months	31.8 ± 19.4	31.6 ± 17.8	.926
6 months	18.0 ± 15.6	18.1 ± 18.6	.974
SANE
Baseline	43.5 ± 22.8	44.0 ± 21.0	.875
6 weeks	50.8 ± 23.6	55.6 ± 19.7	.156
3 months	68.4 ± 22.9	68.1 ± 20.7	.935
6 months	81.0 ± 22.0	77.1 ± 27.2	.311

Note. Continuous variables are presented as mean ± SD. Categorical variables are presented as N (%). PRWHE = patient-reported wrist/hand evaluation; SANE = single assessment numeric evaluation.

Sex, age, injury to the dominant hand, smoking status, and procedural technique did not significantly differ between patients who received operation for CMC arthritis on their dominant hand and those who received surgery on their nondominant hand (P ≥ .349; Table 2). Hand dominance was not associated with PRWHE or SANE scores at any follow-up timepoint (P > .422 and P > .156, respectively). No significant difference was found between hand dominance and MCID attainment at 6 weeks (P = .889), 3 months (P = .127), or 6 months (P = .422).

Discussion

This retrospective cohort study was designed to elucidate the relationship between hand dominance and PROs in end-stage CMC joints requiring surgical invention. The prevalence of CMC arthritis makes understanding postoperative outcomes paramount to setting recovery expectations. We hypothesized that PROs would not differ significantly based on whether the patient received an operation on their dominant or nondominant hand. This study comprised 2 patient cohorts who received surgical treatment for CMC arthritis on either their dominant or nondominant hand and completed the PRWHE at baseline, 6 weeks, 3 months, and 6 months postoperatively. The 2 cohorts did not significantly differ in age, tourniquet time, surgical procedure, primary surgeon, type of anesthetic, or sex distribution. Both cohorts had a mean age of above 60 years demonstrating the progressive nature of OA and the typical age presentation. Addressing our primary research aim, PRWHE and SANE scores did not significantly differ according to hand dominance at preoperative baseline or any postoperative timepoint over the 6-month recovery period.

Previous studies have used the PRWHE after CMC arthroplasty at long-term follow-up timepoints. Studies reporting follow-ups within 5 years demonstrated a PRWHE score of 10 that may imply continuing improvement of symptoms and patient satisfaction after 6 months when interpreted in conjunction with our results (dominant: 18.0 ± 15.6, nondominant: 18.1 ± 18.6).^12,13 One previous study found a much higher PRWHE score of 41.5 at a mean follow-up of 54 months but noted that their results may have been skewed by significant OA in other hand joints impacting attempts to determine scores for the CMC joint exclusively. ¹⁴ These studies do not provide baseline PRWHE scores to compare improvement between preoperative and postoperative states. Beyond the scope of our present study, research including follow-ups beyond 5 years lists PRWHE scores ranging from 12.6 to 19.5 and demonstrates disagreement as to whether improvement continues multiple years after surgery.^12,15 These results may imply that most improvement comes within the first 6 months after surgery, while minimal benefit may still occur beyond a 6-month timepoint. Handedness was recorded in some instances but was not assessed for correlation to PRWHE scores.

In a study verifying the use of SANE scores for various hand surgeries, Gire et al ¹⁶ found a median postoperative SANE score of 75 and a median increase of 20 from baseline with a mean follow-up of 6 (range = 3-13) months, which compares favorably with our mean scores at 6 months (dominant: 81.0 ± 22.0, nondominant: 77.1 ± 27.2). To the author’s knowledge, there have been no prior studies that have assessed the effect of hand dominance on PROs in the setting of CMC arthritis. However, other previous literature demonstrates distinct outcomes for other upper extremity operations based on hand dominance. In one study, surgical release for severe carpal tunnel syndrome demonstrated a shorter time to complete symptom resolution when performed in the nondominant hand. ¹⁷ Alternatively, procedures for distal radius fractures (DRFs) performed on the dominant side have shorter healing times, better 3-month grip strength, and improved sensorimotor testing.^{18 -20} Beaulé et al ²¹ reported significantly worse patient-reported disability after dominant-sided DRF surgery by investigating a wide variety of specific daily activities. While our results demonstrate no significant difference in using validated PROs according to hand dominance, additional investigation of certain everyday tasks requiring usage of the dominant thumb may be warranted.

This study has multiple strengths and weaknesses. Based on the authors’ literature search, this is one of very few, if any, studies to determine the effect of hand dominance on postoperative CMC arthritis recovery using PROs. This study used a prospectively collected PRO employed in the current CMC arthritis literature.^12,13,15 This measure was specifically validated in the setting of arthroplasty for OA of the CMC joint, and has not demonstrated superiority or inferiority when compared with other PROs for the assessment of CMC arthritis. ¹⁴ In addition, this study included a demographically diverse cohort from a metropolitan area, which increases generalizability, and used shorter follow-up timepoints relative to literature in this area. One pertinent weakness is the bias inherent to the retrospective nature of this research study. The 6-month follow-up period might not capture the entire postoperative recovery following CMC arthroplasty; however, previous literature demonstrates that most PRO improvement occurs within the first 6 months postoperatively. This study also does not carry requisite statistical power to identify effects of procedural technique on our results. This study also omitted comparison of PROs between the operated and nonoperated hands which would have increased the application of the findings. Patient-reported outcomes were limited to PRWHE and SANE and did not include other PROs pertinent to hand and wrist dysfunction. Future investigation should be directed at how hand dominance may differ according to other joints within the hand and further evaluate various MCID calculation methodologies that are not addressed within the present study. Finally, more research is needed to link the short-term PRWHE scores to available long-term studies.

Conclusions

This study found no significant difference in PROs after CMC arthritis surgery between those who received an operation on their dominant hand and those on whom their nondominant hand was operated. Only a select few studies address PROs in the setting of CMC arthroplasty. Furthermore, hand dominance is nearly absent from this subsection of literature. This study offers substantive evidence that hand dominance does not impact PROs in cases of CMC arthritis requiring operative treatment. This information can be used for patient education, expectation management, and during shared decision-making processes.