Hip dislocation and femoral component disassembly after bipolar hemiarthroplasty

• DOI: 10.1097/cm9.0000000000000057
• Publication Date: 2019-01-25T07:24:52Z
• Authors: Yan-Yan Bian; Long-Chao Wang; Ke Xiao; Jin Jin; Bao-Zhong Zhang; Xi-Sheng Weng
• Keywords: Component (thermodynamics)

To the Editor: Bipolar hemiarthroplasty is one of treatment options for unstable femoral neck fracture in elderly. Hip dislocation after hip replacement a common complication but dissociation bipolar prosthesis rare and more serious complication, which always requires open reduction revision. Some authors have reported hip. The present study four cases disassembly primary due to different causes explained mechanism. It will beneficial surgeons who encounter same situation. Case 1: A 79-year-old woman underwent (Smith&Nephew, Switzerland) subcapital left femur. Two days later, while attempting change her position bed, she was struck by sudden pain unable move. On examination, lower limb shortened internally rotated, raising suspicion dislocation. X-ray showed displaced head [Figure 1A]. patient sent operation room (OR) close under general anesthesia. During routine maneuvres, polyethylene cup accidentally dislodged from small prosthesis. fell out acetabulum 1B]. As consequence, surgery performed re-assemble components correct [Table 1].Figure Typical manifestations schematic diagram new manoeuvres. (A) Roentgenograph showing case 1. (B) maneuvres reduction. Dissociation between ball head. separated lying above inside. (C) hemiarthroplasty. (D) outer shell locked behind acetabular rim, with clip as marker front. (E) successful push-turnover-pull manipulation (F) Diagrammatic sketch so-called “bottle-opener mechanism”. (G) affected toward proximal part. (H) Graph turn over on effect leverage. (I) Successful dislocation.Table Characteristics component hemiarthroplastyCase 2: 92-year-old spinal anesthesia right femur month ago. Nine off bed sustained posterior OR accidently occurred. into acetabulum. Open result. Intraoperatively, found intact locking mechanism functioned well. were put back place. After operation, given an orthopedic cast immobilization 4 weeks. 3: An 85-year-old presented our emergency department right-sided fall. identified transcervical Six suffered could not move changing bed. Plain film radiographs Close discharged week. Four weeks discharge, had again attempt sit up chair. When performed, prosthetic dissociated. taken where revision Intra-operatively we that external rotators torn, disassembled extruding through repaired capsule abductor. No evidence fractures observed, remained well fixed. substituted longer (from 0 mm–8 mm) order obtain stronger soft tissue tension. reduced its stability confirmed. 4: 76-year-old man his he leg falling down floor. 1C]. Patient Before reduction, rim 1D]. We therefore push proximally rotated adducted leg, then 1E]. Hemiarthroplasty option elderly fractures.[1] gains advantages total arthroplasty simpler procedures, less surgical trauma, quicker postoperative recovery. brings satisfactory early long-term outcomes recognized having comparative, if better, designs than unipolar ones.[2–4] Incidence low[5,6] significantly hemiarthroplasty.[7,8] But prosthesis, occurs head.[9,10] Disassembly can occur many reasons. In most cases, inner closed this happens, be along surgeon apply traction force reduce dislocated hip, would continued pulled. called mechanism” 1F]. all happened during anesthesia, approach such situations, translation adduction fluoroscopic supervision recommended 1G], leverage 1H]. That makes convex rather edge contact bone. Then follow 1I]. Excessive wear liner failure ring also contribute dissociation. Under circumstance, usually still lies iatrogenic warrants caution. Once fails, has performed. Locking must inspected short rotator muscle should repaired. Proper tension maintained, necessary, increasing length (offset) help maintain stability. Declaration consent certify they obtained appropriate forms. form, patients their images other clinical information journal. understand name initials published efforts made conceal identity, anonymity cannot guaranteed. Conflicts interest None. Author contributions Bian YY: Preparation report, literature review, writing paper; Xiao K: Collecting data; Weng XS: Providing ideas, giving recommendations, reviewing Jin J Wang LC: Zhang BZ: data paper.