Can Pyrocarbon be used as a functional spacer for the treatment of recalcitrant shoulder infections?

Abstract

The most common treatment approach in periprosthetic joint infection (PJI) and chronic shoulder joint infection (SJI) is a two-stage revision involving interval placement of an antibiotic cement spacer or a resection arthroplasty. Knowing that Pyrocarbon has a smooth surface that prevents pathogen adhesion, the question arises whether it could be used as a temporary or permanent functional spacer? The primary objective of the present study was to assess the rate of infection eradication after temporary or definitive implantation of Pyrocarbon Interposition Shoulder Arthroplasty (PISA) in patients with recalcitrant PJI or SJI. Our secondary objective was to assess mid-term clinical and radiographic outcomes. Fifteen patients (mean age: 52±19 years) with chronic shoulder infection underwent, after joint débridement, implantation of PISA (InSpyre; Tornier-Stryker, Kalamazoo, MI, USA) with tailored perioperative antibiotics. In 7 cases, PJI occurred after hemiarthroplasty (n=2), reverse shoulder arthroplasty (n=2), hemireverse (n=2), and resurfacing arthroplasty (n=1). In 8 cases, SJI occurred in the context of failed surgery after fracture sequelae (n=4), instability (n=2), and cuff arthropathy (n=2). Preoperatively, patients had a mean of 3 previous failed surgeries before PISA implantation. Patients were evaluated with clinical, laboratory, and radiographic assessment at a minimum of 2 years after surgery. At a mean follow-up of 55±18 months, no patient experienced reinfection after temporary (3cases) or definitive (12 cases) PISA implantation. The adjusted Constant score increased from 33%±20 preoperatively to 65%±28 at last follow-up and SSV from 22%±19 to 63%±23 (P<.001). Active forward elevation increased from 27°±19 to 113°±30, external rotation from 7°±21 to 25°±25, and internal rotation level 3±2 to level 5±2 points (P<. 001). On final radiographs of definitive PISA, complete humeral densification, or a neocortex, formed around the implant in 64% (7/11). Our data suggest that, after washout, débridement and tailored antibiotics, PISA can be used as a temporary or definitive functional spacer for the treatment of recalcitrant shoulder infections and presents the following advantages: (1) PISA does not seem to be a risk for recurrent infection thanks to the antibacterial property of Pyrocarbon; (2) PISA can be used as a temporary or a definitive spacer without causing bone erosion, thanks to the low modulus of elasticity of Pyrocarbon; (3) PISA can be used as a salvage procedure in case of complete glenoid or humeral destruction, thanks to the sphericity of the implant needing no implant anchorage.