Assessing the usefulness of diagnostic shoulder arthroscopy in evaluating painful shoulder replacement: a retrospective case series.

HYPOTHESIS: Persistent pain after total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (rTSA) is challenging to evaluate when conventional imaging, laboratory testing, and joint aspiration are inconclusive. The purpose of this study was to evaluate the diagnostic utility of shoulder arthroscopy in identifying infectious and mechanical causes of pain and to assess its impact on subsequent management decisions.

METHODS

This study was a retrospective case series performed at a single institution evaluating adults who underwent diagnostic shoulder arthroscopy for persistent pain following total or rTSA between 2021 and 2025. Study inclusion required an equivocal preoperative evaluation, defined as absence of mechanical failure or infection on radiographs, computed tomography, and or synovial fluid aspiration. Intra-articular lidocaine injections were used in select cases for intra-articular sources of pain prior to surgery. Arthroscopy was performed under general anesthesia in the beach chair position with standard anterior and posterior portals. Intra-articular structures, prosthetic components, and surrounding soft tissue were assessed for polyethylene wear, impingement, metallosis, bone resorption, component disengagement, and gross purulence. Tissue samples were obtained for aerobic and anaerobic cultures and held for a minimum of 14 days. Descriptive statistics were used to report findings.

RESULTS

Twenty-nine patients met inclusion criteria, including 25 rTSA and 4 TSA cases. Preoperative radiographs and computed tomography demonstrated stable implants in all cases. Arthroscopy identified intra-articular mechanical pathology in 15 patients (51.7%), including polyethylene wear, impingement, metallosis, bone resorption, or implant disengagement. Arthroscopic cultures were positive in 5 patients (17.2%), most commonly for Cutibacterium acnes. Four culture-positive patients also demonstrated concomitant mechanical pathology. No intra-articular abnormalities were identified in 12 patients (41.4%). Arthroscopy-guided revision surgery was performed in 13 patients (44.8%), while the remaining patients were managed nonoperatively.

DISCUSSION: Diagnostic shoulder arthroscopy provided clinically meaningful diagnostic information in patients with painful shoulder arthroplasty and nondiagnostic preoperative evaluations. Arthroscopy identified occult infection, mechanical pathology, or the absence of intra-articular disease, directly influencing subsequent management decisions. These findings support the use of arthroscopy as an adjunctive diagnostic tool in select patients with unresolved pain following shoulder arthroplasty.