Dual-Mobility Cups in Patients Undergoing Primary Total Hip Arthroplasty with Prior Lumbar Spine Fusion: A Systematic Review

Spine and hip abnormalities frequently occur together in most of the orthopedic population; therefore, both of these abnormalities impact the outcomes of the modalities that are being used. Few studies have reported reduced dislocation and revision rates with the use of dual-mobility cups (DMCs) in high-risk lumbar spine fusion (LSF) patients undergoing primary total hip arthroplasty (THA). This study aims to clarify the relationship between pre-existing lumbar spinal fusion and the outcomes of THA with dual-mobility constructs. We systematically reviewed the current literature through several online databases following PRISMA protocol and the Cochrane Handbook for Systematic Reviews of Interventions. We used the methodological index for non-randomized studies (MINORS) to evaluate the methodological quality of the included trials. Four studies examined the feasibility and effectiveness of dual-mobility cups in patients undergoing primary THA with prior LSF. Two studies were conducted in the United States, while the other two originated in Finland and France, respectively. The included studies enrolled 284 patients. Most of these patients had instrumented fusions. Seventy-eight percent of patients received one- or two-level fusions. The average age across the studies was 68.22 and the mean body mass index was 28. No cases of postoperative DMC implant dislocations were identified. The incidence of postoperative complications was 6% (10/173), including deep venous thrombosis, periprosthetic loosening, infection, and fracture, greater trochanteric fracture, and superficial wound infections. Most included studies had some methodological limitations, with an average MINORS score of 10.5 +/- 5.8. The use of dual-mobility cups in these high-risk patients undergoing total hip arthroplasty may lead to reduced dislocation rates and postoperative complications. Further long-term follow-up studies are warranted to support these findings.