Porous tantalum rods improve the hip joint function of patients with avascular necrosis of the femoral head after femoral neck fracture surgery: study protocol of a randomized controlled trial

Abstract

Background: After femoral neck fracture, insufficient blood supply to the femoral head can cause avascular necrosis of this region. This can lead to increased treatment difficulty, and may greatly influence the recovery of hip joint function. Core decompression with bone grafting is a common treatment for avascular necrosis of the femoral head. An implanted porous tantalum rod, which is a bone trabecula-like metal implant that is used to support the weight-bearing area of necrotic bone, can prevent further collapse of the necrotic area. This strategy has led to favorable effects in the early treatment of avascular necrosis of the femoral head. However, few randomized controlled studies have reported on porous tantalum rod implantation for treatment of avascular necrosis of the femoral head after femoral neck fracture surgery. We hypothesized that, compared with core decompression alone, core decompression with porous tantalum rod implantation would have a more beneficial effect of the hip joint function of patients with avascular necrosis of the femoral head after femoral neck fracture surgery. Methods/Design: This is a prospective, single-center, randomized controlled, open-label trial, which will be performed in the Department of Orthopedic Trauma, Qinghai University Affiliated Hospital, China. A total of 100 patients with avascular necrosis of the femoral head after femoral neck fracture surgery will be randomly assigned to undergo core decompression and porous tantalum rod implantation (experimental group, n = 50) or core decompression only (control group, n = 50). All patients will be followed up for 1 year. The primary outcome measure is the percentage of patients (of the total number of patients in each group) whose hip joint function is graded as excellent as per Harris hip scores 12 months after surgery. This value will be used to evaluate the recovery of hip joint function. Secondary outcome measures include (1) the percentage of patients with excellent hip joint function, prior to and 1 and 6 months after surgery (of the total number of patients in each group); (2) hip joint pain score on a Visual Analogue Scale prior to and 1, 6, and 12 months after surgery, which will be used to evaluate the severity of pain; (3) the percentage of patients presenting with femoral head collapse, prosthesis loosening, and peri-prosthesis infection 6 and 12 months after surgery, which will be used to evaluate the biocompatibility of the biomaterial with the host site; (4) incidence of complications 6 and 12 months after surgery, which will be used to evaluate the safety of porous tantalum rod implantation. Discussion: This study is powered to validate the biocompatibility and therapeutic effects of porous tantalum rods in the treatment of avascular necrosis of the femoral head after femoral neck fracture, with the hopes that this novel surgical method represents a superior treatment for this disease. Trial registration: ClinicalTrial.gov identifier: NCT02877472; registered on 19 August 2016. Ethics: This study protocol has been approved by the Medical Ethics Committee of Qinghai University Affiliated Hospital of China (approval number: QHY1016B) and will be performed in accordance with the guidelines of the Declaration of Helsinki, formulated by the World Medical Association. Informed consent: Signed informed consent regarding trial procedure and treatment will be obtained from each patient.