Malformation correction of femoral medullary cavity in hip revision arthroplasty for implant loosening / 中华骨科杂志

ABSTRACT

Objective To investigate the results of malformation correction of femoral medullary cavity in hip revision for implant loosening.Methods From January 2010 to December 2016,24 patients (24 hips) were received hip revision arthroplasty using femoral medullary cavity correction technique.Nineteen patients (19 hips) were followed up.Ten patients were male and 9 female with mean age of 69.1 years (range 44-84).The followings are the reasons for revision15 patients for osteolysis with implant loosening,4 for periprosthetic infection,bone cement implant and stage two revision.Fourteen patients received bone cement implants and 5 received uncemented implants for primary arthroplasty.During revision,13 patients underwent femoral bone cortical windowing and 6 received extended trochanteric osteotomy technique to exposure medullary cavity,grinding sclerotic bone and filling bone defect,correcting cavity to normal morphology and implant anatomic revision stem.The hip function was evaluated with Harris score.Peri-operation complications were also collected.Implant position,fixation condition and implant loosening were evaluated from the supine anteroposterior radiograph of the pelvic and a lateral hip radiograph.Results The mean follow up duration was 58 months (range 17-82).The mean Harris score improved significantly from 41.52±10.94 (range 17-64) preoperatively to 91.63±6.70 (range 72-99) postoperatively.Mild limp occurred in 2 patients (11％,2/19) and intermittent hip pain occurred in 1 patient (5％,1/19).Peri-prosthetic fracture occurred in 1 patient and was treated with double stranded wire fixation.No deep venous thrombosis,dislocation and infection occurred.No revision was performed.For bone cortical windowing patients,the length of the cortical windows varied from 3.0 to 9.0 cm (mean 4.78±1.84),the width ranged from 1.0-3.0 cm (mean 1.82± 0.50).For extended trochanteric osteotomy patient,the length of the osteotomy varied form 12.0-20.0 cm (mean 16.00±3.37),the width ranged from 2.5 to 3.0 cm (mean 2.75±0.29).All the revision stems were in neutral position without varus or valgus.All the osteotomy sites were bone heal and fracture lines were disappeared.Conclusion In order to restore the normal bone cavity morphology and femoral alignment,correction bone cavity technique is required in patients receiving hip revision with femoral cavity malformation and anatomy alignment abnormal.This technique can ensure neutral position of revision stem without peri-prosthetic fracture.