Arthroplasty of the proximal interphalangeal joint with the Tactys ® modular prosthesis: Results in case of index finger and clinodactyly.

There are various surgical solutions for arthrosis of the proximal interphalangeal (PIP) joint: arthrodesis or denervation. Clinodactyly that is major and the index fingers are traditional contraindications for PIP arthroplasty prostheses. The recurrence of clinodactyly with ligament imbalance and mechanical complications are known complications. The purpose of our study was to evaluate the objective and subjective clinical results and radiological complications of Tactys® prostheses on the PIP joint of the index fingers or with clinodactyly of more than 5° in the other fingers. Two surgeons have implanted 35 total gliding modular Tactys® prostheses in 29 women and 3 men since 2010. The indications for surgery were arthrotic and painful PIP joints. Average pre-op clinodactyly was 7.03° (5-30°) with ulnar deviation (29 cases). Eleven index fingers presented with average clinodactyly of 14.2° (10-20°). The digits operated on were as follows: 13 index fingers, 14 middle fingers, 5 ring fingers and 3 little fingers. Arthrosis was primitive in 23 cases, post-traumatic in 6 cases and rheumatoid in 6 cases. The average age of patients undergoing surgery was 63.7 years (40-85). Objective (mobility, strength, index finger exclusion, scores, clinodactyly) and subjective (patient satisfaction, pain) functional results were collected by a neutral and independent observer, as were radiological complications. With an average follow-up of 2.6 years (1-6.3), the range of motion in all digits improved by 5.4° on average (55.5-60.8). The improvement in range of motion in the index fingers was 4.5° (57-61.5). Clinodactyly in all fingers was corrected by 1.36° (0-20). In the index fingers, average clinodactyly was 1.3° (0-10). The pinch strength in all PIP joints improved significantly from 2.3 kg (0.5-5) to 3.7 kg (1-8). On the PIP of the index fingers, the pinch strength had increased significantly from 2.5 kg (1-4) before surgery to 3.8 kg (1-7.5) post-op. Functional scores improved: PRWE (from 55.36 to 26.7/100), Quick DASH (from 54.6 to 30.5/100). Patient satisfaction was excellent in 15 cases, good in 8 cases, average in 10 cases, poor in 2 cases. The average VAS Pain Score improved from 5.6 to 1.45. We found 3 major complications requiring surgery: 2 stiffening and 1 mechanical loosening with secondary arthrodesis. Five patients presented with non-troublesome, reducible swan neck deformity and one algodystrophy. A gliding, fixed Tactys® prosthesis allowed us to restore ligament balance and to optimally rebalance the periarticular structures. The improvement in range of motion and the correction of clinodactyly was maintained over time. Total arthroplasty of the PIP with a Tactys® is no longer a formal contraindication for the index fingers and in cases of clinodactyly of more than 5°.