Dual Mobility Cup in Fractures of the Femoral Neck in Neuromuscular Disorders and Cognitive Dysfunction Patients above 60 years-old

Dislocation rate of total hip arthroplasty (THA) can be as high as 20% for patients withfracture neck of femur, which is a disastrous complication in these vulnerable patients. Numeroustechniques, including bipolar arthroplasty and constrained liner, have been adopted to minimize therisk of dislocation. We aimed to evaluate the role of dual mobility Cups in treating patients with fracturesof the femoral neck with high risk of postoperative dislocation due to neuromuscular instabilitydisorders. A prospective cohort study was conducted (place is blinded as asked during submission), between 2016and 2019, with a post-operative follow up period of two years. We included skeletally mature patients with femoralneck fractures having neuromuscular disorders and cognitive dysfunction who are candidates for THA above 60years. Patients were then followed up clinically and radiographically at the clinic using Harris Hip Score (HHS) andx-rays at six weeks, six months, one year and two years postoperatively. Twenty patients (20 hips) with femoral neck fractures with high risk of postoperative dislocation due toneuromuscular instability disorders undergoing dual mobility cup were included. The mean age of patients was 70.5±6.42 years. There is highly significant difference between HHS preoperatively and postoperatively (six weeks, sixmonths and one, two years) p<0.001.Infection occurred in one case (5 %), sciatic nerve injury occurred in one case(5%), and none of the patients had postoperative dislocation. Dual mobility cup is effective in preventing early dislocation in patients suffered from fracture neck offemur with muscle weakness due to neurologic disorders. Level of evidence: IV