Pyrocarbon implants in shoulder arthroplasty: a systematic review and meta-analysis

Chrome-cobalt alloy, pyrocarbon (PyC), and ceramic have all been used for humeral head replacement in shoulder arthroplasty. It remains unclear whether outcomes differ by material. PyC implants are increasingly used, including PyC interposition shoulder arthroplasty (PISA) and PyC hemiarthroplasty (HA-PyC). The objective of the present study is to systematically evaluate implant survival, functional outcomes (Constant score, visual analog scale for pain, and Subjective Shoulder Value), revision rates (defined as any reoperation involving implant removal, replacement, or conversion), complications, and radiological changes associated with PyC in shoulder arthroplasty.

A systematic review and meta-analysis was performed. MEDLINE, Embase, Cochrane, Scopus, and Web of Science were searched on April 25, 2025, without language or date restrictions. Studies with ≥1-year follow-up were included. Data were pooled using random-effects models; quality was assessed using the Methodological Index for Non-Randomized Studies tool, and certainty was graded according to Grading of Recommendations Assessment, Development, and Evaluation guidelines. The protocol was registered in PROSPERO (CRD420251059452).

Twenty studies (2017-2025) were included. 1,117 patients had undergone either HA-PyC or PISA. Follow-up ranged from 1 to 11 years. Primary osteoarthritis was the most common indication (31%-86%). Pooled implant survival was 96% (95% confidence interval (CI), 94%-98%) at the most recent follow-up, with substantial heterogeneity (I² = 56.8%). Subgroup analysis revealed numerical differences across groups: survival was lower after PISA (87%) compared to stemmed HA-PyC (98%) and PyC resurfacing implants (96%). The overall revision rate was 5% (12% PISA; 3% HA-PyC; and 5% PyC resurfacing). The pooled mean age was approximately 50 years. Functional outcomes, Constant score, visual analog scale for pain, and Subjective Shoulder Value improved significantly, alongside improvements in range of motion. Glenoid wear rate varied widely, ranging from 6% to 100% in the HA-PyC group and from 3% to 90% in the PISA group. When longitudinal progression was evaluated, glenoid erosion increased by 6% to 39% in the HA-PyC group. In the PISA group, progression was reported in only one study, with a rate of 71%. Despite the radiographic incidence of glenoid wear, revision due to symptomatic (painful) erosion was uncommon, occurring in only 4 patients.

The reported survival rate of stemmed HA-PyC is high and encouraging. When PyC has been used for resurfacing HA or in the form of interposition (PISA), reported survivorship has been inferior. Careful patient selection and surgical technique are essential. Further high-quality comparative trials are required to clarify long-term benefits and material-specific risks.