Abstract / Summary
Background: Total hip arthroplasty (THA) and the diagnosis of periprosthetic joint infection (PJI) have each acquired a technology that measures with high precision: intraoperative navigation, which reports component position to within a few degrees, and molecular methods, which identify the infecting organism and the host response at genomic resolution. Objective: To establish whether the measured accuracy has been shown to reach the patient as a clinical outcome. Methods: This is a narrative review, reported according to SANRA. MEDLINE, Scopus, and Web of Science databases were searched from inception to 31 August 2026. English-language studies in humans were eligible if they reported positional or diagnostic accuracy, a patient-level clinical or economic outcome after THA or after treatment of PJI or osteomyelitis, or a factor modifying the relation between the two. Animal, in vitro, and cadaveric studies, conference abstracts, and reports without extractable data were excluded. Forty studies were included. No pooled estimate was calculated, and no new statistical analysis was performed. Results: Navigation reduced positional outliers consistently, but in two matched claims-based cohorts of patients with morbid obesity (4499 and 5835 patients), it was not associated with lower rates of PJI, dislocation, periprosthetic fracture, mechanical loosening, or revision within two years. Candidate immunogenetic variants in osteomyelitis have never been tested against a treatment decision. Metagenomic sequencing was no more accurate than culture (sensitivity 63.2% versus 68.4%; specificity 80.0% versus 95.0%) except after antibiotic exposure. Reported infection rates and test accuracy both change with the case definition applied. Conclusions: In both settings, the limiting factor is the design of the studies linking measurement to outcome rather than the precision of the measurement.