Contraindications of femoral implants in primary total hip arthroplasty

Aims: Litigation related to total hip arthroplasty (THA) is a growing concern. Manufacturer-specified contraindications for femoral implants may influence legal outcomes, particularly when common patient characteristics such as obesity are listed. This study identified manufacturer-listed contraindications for femoral implants used in primary THA and evaluated their medicolegal implications within the frameworks of medical negligence and informed consent law in England and Wales. Methods: The 11 most commonly used femoral implants were identified from the National Joint Registry of England, Wales, and Northern Ireland. For each implant, manufacturer surgical technique guides were reviewed to extract contraindications, relative contraindications, and warnings. A structured medicolegal analysis was conducted within the frameworks of medical negligence and informed consent law, drawing on landmark case law and peer-reviewed medicolegal scholarship, supplemented by consultation with legal professionals who specialize in orthopaedic device litigation. Results: Two implants cited obesity or morbid obesity as a contraindication; four reported obesity as a warning. Nine implants listed inadequate bone quality as a contraindication, and two as a relative contraindication. Neuromuscular disease was contraindicated in nine implants, and a relative contraindication in two. Infection was contraindicated in all eleven implants. Vascular deficiency was a contraindication in six implants, and a relative contraindication in two. Deficient musculature was contraindicated in five implants and a relative contraindication in two. Conclusion: Many manufacturer-listed contraindications correspond to clinical characteristics commonly found in THA patients. These contraindications do not preclude implant use when supported by evidence and sound clinical judgement, but carry significant medicolegal implications under negligence and informed consent law. Once a manufacturer has communicated a contraindication, medicolegal scrutiny may shift to the surgeon's decision-making under two distinct frameworks, namely the standard of care and informed consent. Surgeons should know their implant-specific contraindications, ensure decisions are evidence-based and documented, and explicitly disclose elevated risks to patients.