Clinical Study On The Method Of Balancing Leg Length Discrepancy By Prosthesis Implantation Position In Total Hip Arthroplasty

BackgroundTotal hip arthroplasty（THA）as an effective method for the treatment of various factors causing terminal hip lesions,can restore hip function,relieve pain symptoms,maintain hip stability and adjust the affected limb deformity.Leg length discrepancy（LLD）is one of the most important complications after total hip replacement,which can cause lameness,persistent lower limb pain,and shortened prosthesis life.LLD is a major cause of patient dissatisfaction and litigation.At present,more and more clinicians pay attention to the leg length discrepancy after surgery.Although there are various methods to balance the leg length discrepancy at home and abroad,the efficacy of various methods is still controversial.ObjectiveThrough the combined control of acetabular prosthesis and femoral stalk prosthesis implantation position to balance the lower extremity length difference strategy,a simple,scientific and highly repeatable new method was obtained,providing a new idea for clinicians to avoid postoperative limb length discrepancy.MethodA total of 100 patients who underwent total hip arthroplasty in the First Affiliated Hospital of Xinxiang Medical College from October 2018 to October 2020 were selected according to inclusion and exclusion criteria.The study subjects were divided into two groups according to different surgical methods: Observation group: a total of 48 patients controlled limb length through joint control of acetabulum and femoral stem implant position;In the control group,a total of 52 patients were treated with kirschner wire marking assisted localization to control limb length.T The general clinical data of the two groups were compared.The preoperative and postoperative imaging LLD and clinical LLD of lower limbs were compared between the two groups,as well as the preoperative and postoperative differences,and the postoperative imaging LLD ≤5mm and > 5mm of the two groups were compared and analyzed.The hip functional recovery of the two groups was evaluated by comparing the hip Harris score before surgery,14 days after surgery,3 months and 6 months after surgery,and the preoperative and postoperative differences.The incidence of postoperative complications in the two groups was compared,including wound healing,deep vein thrombosis,pulmonary infection,claudication,persistent pain in the lower extremities,and subjective feelings of unequal length of the lower extremities.Result1.The preoperative imaging LLD and clinical LLD of the observation group were7.92±2.02 mm and 7.80±1.99 mm respectively.The postoperative imaging LLD was2.65±1.16 mm and the clinical LLD was 2.57±1.10 mm.The preoperative imaging LLD and clinical LLD of the control group were 8.19±2.08 mm and 8.12±2.06 mm respectively.The postoperative imaging LLD was 3.71±1.09 mm and the clinical LLD was3.58±1.06 mm.There was no statistically significant difference between the two groups（P >0.05）,and there was statistically significant difference between the two groups in postoperative imaging LLD and clinical LLD compared with their preoperative LLD（P <0.05）.The methods provided by both groups could effectively restore postoperative limb length.2.The two groups were divided into the distribution of LLD ≤ 5mm and > 5mm in postoperative imaging.The observation group had LLD ≤ 5mm,while the control group had LLD > 5mm in 6 patients.In the recovery of patients with postoperative imaging LLD≤5mm,the methods provided by the observation group were superior to those provided by the control group,with statistical significance（P < 0.05）.3.There was no significant difference in Harris hip score between the two groups before surgery,14 days after surgery,3 months after surgery and 6 months after surgery（P >0.05）.Harris hip score at each time point after surgery was significantly improved compared with that before surgery,with statistical significance（P < 0.05）,indicating that hip function in both groups was effectively improved.4.Delayed wound healing occurred in 1 patient in the observation group,and the incidence of postoperative complications was 2.08%.In the control group,there was 1patient with delayed wound healing,1 patient with deep venous thrombosis,2 patients with postoperative claudication,1 patient with persistent pain symptoms of lower limbs,and 3patients with subjective feeling of unequal length of lower limbs.The incidence of postoperative complications was 15.38%.The incidence of postoperative complications in the observation group was significantly better than that in the control group,with statistical significance（P < 0.05）.ConclusionThe methods provided by the observation group and the control group could effectively restore the lower limb length.As a scientific,effective and highly repeatable new method,the method provided by the observation group can accurately control the postoperative imaging LLD within 5mm and effectively reduce the occurrence of complications after total hip replacement.