Proximal Interphalangeal Joint Replacement with Surface Replacement Arthroplasty (SR-PIP): Functional Results and Complications.

The purpose of the study was to investigate patients with proximal interphalangeal (PIP) joint replacements regarding postoperative function, pain, complications and incidence of reoperations. From 2000 to 2007, 23 patients (11 male, 12 female) with an average age of 47 years (19-72 years) who had symptomatic posttraumatic (15) or idiopathic arthritis (nine) in 24 PIP joints underwent unconstrained PIP joint replacements (formerly AVANTA, now Small Bone Innovations(TM)). All 23 patients were instructed in special hand exercises starting the first postoperative day. Thirteen of 23 patients had previous operations. The median history of pain was 12 months (2-120). Fourteen of 24 prostheses needed reoperations (58%): teno-arthrolysis (9×), PIP tenodesis (one in three with swan neck deformity) and explantation (four with infections/loosening). The four explantations resulted in a PIP joint arthrodesis in all cases. Twenty-two patients were available for follow-up at an average of 27 months (4-73 months) postoperatively. The median postoperative pinch grip was 7.6 lbs (4-28 lbs), and the disabilities of the arm, shoulder and hand score was 24 (1-58). The active range of motion of the PIP joint was 33° preoperatively (min 0°, max 75°) and 54° postoperatively (min 0°, max 90°). On the Visual Analogue Pain Scale (VAS, range 0-10), seven patients had mild (VAS 1-3) and four moderate pain (VAS 4-7) in the finger on exercise. Seventy percent were overall satisfied with operation and functional results. The results of surface replacement arthroplasty of the PIP joint are overall satisfying; however, postoperative complications and incidence of reoperations are noticeable and should be mentioned to the patients in the preoperative setting.