This prospective controlled clinical trial compares the outcomes of metacarpophalangeal (MCP) arthroplasty in rheumatoid arthritis patients using the Swanson (S) and NeuFlex (N) MCP implants.

Forty hands (thirty-seven patients) were randomised and evaluated preoperatively and at one year following MCP arthroplasty in digits two to five for range of motion (ROM; active and passive extension and flexion), ulnar drift and grip strength.

Both implants restored extension and corrected flexion deformities. There was no significant difference in extension of all digits (summed) between the NeuFlex and Swanson implants (N: −20.8°; S: −13.8°; p=0.29). The NeuFlex implant, which is pre-flexed at 30°, preserved more flexion at the MCP joint than the Swanson implant in all digits (summed) (N:74.5°; S:55.8°; p=0.005), with the greatest difference observed in the fifth digit (N:69.6°; S:48.7°; p=0.009). The total arc of motion improved in all digits, with no significant differences between the Neu-Flex and Swanson groups in the second through fourth digits (N:53.8°; S:43.8°; p=0.154); a significantly greater improvement was observed in the NeuFlex group for the fifth digit (N:53.3°; S:42.5°; p=0.028). Both implants corrected ulnar drift deformity, while neither led to loss of grip strength.

Hand function as measured by Sollerman score and Michigan Hand Questionnaire (MHQ) improved significantly in both groups (p=0.0119, p< 0.0001, respectively) with no significant difference between the Swanson and NeuFlex implants, except for MHQ function, aesthetics, and overall scores, which demonstrated superiority of the Swanson.

Overall, there was a significant improvement in the range of motion, deformity and grip strength following MCP arthroplasty for the full patient group. While both implants restored similar amounts of extension, the NeuFlex implant maintained greater flexion and total range of motion, with the greatest difference in the fifth digit. The Swanson implant had better MHQ function and aesthetics subscores.

Metacarpophalangeal (MP) arthroplasty restores function, corrects deformity and reduces pain in patients with rheumatoid arthritis (RA). In a randomised controlled trial of MP hand reconstruction, we investigated RA patient motivations and expectations and whether self-reported patient satisfaction with appearance, function and pain correlated with objective and subjective outcome measures.

From forty patients (one hundred and sixty joints), randomised for an MP arthroplasty trial, we collected preoperative and postoperative objective measures (range of motion (ROM), ulnar drift, JAMAR grip strength), subjective measures (Michigan Hand Questionnaire (MHQ), Sollerman Hand Function test), pre-operative patient-reported motivations and expectations of surgery (appearance, function, pain), and postoperative patient-reported improvement and satisfaction with surgery (appearance, function, pain, overall). Spearman correlations determined associations between patient satisfaction and specific outcome measures.

Mean age was 60.3 years, mean disease duration at time of surgery 22.9 years, mean follow-up time 386.4 days, and 87.5% of patients were female. Seven of forty patients (17.5%) rated improved function as the single biggest motivator for surgery, one (2.5%) rated pain, the remainder (80%) rated two or more motivators equally high. Function was rated as the most important or one of the most important motivators for surgery by 92.5% of patients, pain by 67.5% and appearance by 47.5%. Several MHQ subscores (function, work, ADL) were moderately correlated (|rho|=0.67, 0.52, 0.54, respectively), and the Sollerman Score was weakly correlated (|rho|=0.39) with self-reported satisfaction with function, but ROM and grip strength were not (|rho||< 0.25). Self-reported satisfaction scores for appearance, pain and overall were moderately correlated with analogous MHQ subscores (|rho|=0.78, 0.65, 0.71, respectively).

Patient expectations of MCP arthroplasty were uniformly high. The greatest motivation for surgery was functional improvement. Pain was highly ranked, but nearly half of the patients rated hand appearance as one of the highest co-ranked motivators. Patient satisfaction correlated poorly with traditional outcome measures (ROM, grip strength) and moderately with subjective outcome measures (MHQ). Aesthetic appearance is probably underrated as a motivator for surgery and determinant of satisfaction.