Intraoperative acetabular fracture and pelvic discontinuity in thr
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Transcript of Intraoperative acetabular fracture and pelvic discontinuity in thr
Intraoperative acetabular fracture and pelvic discontinuity in THR – Leave it or Treat it
• Periprosthetic acetabular fracture rare complication.
• Increasing incidence with uncemented cups
Periprosthetic Acetabular fracture
• Intraop. fracture with comp. Insertion
• Intraop. fracture with comp. Removal
• Traumatic Fracture
• Spontaneous Fracture
• Pelvic discontinuity
Intraop Periprosth. Acetabular fracture with Component insertion
• Exact prevalance unknown
• Depends on – a) Surgical tech. used for comp. stability b) Quality of host bone
Surgical technique used for component stability
• Line to line reaming - - size of comp. same as last reamer diameter - adjunctive screw used for fixation
Disdavantage of screw fixation Neurovascular inj fretting & corrosion wear & osteolysis
Surgical technique used for component stability
• Under Reaming of Acetabulum Reamer 1-2 size smaller than component Stability without adjunctive screws
Incidence of intraop. fracture
Intraop Periprosth. Acetabular fracture Cadaver studies
• Kim et al
• Increased incidence with comp oversized by 2-4 mm
• Smaller sized acetabulum – higher chance of intraop fracture
• Large size acetabulum – rim fracture• Small size acetabulum - coloumn fracture
Intraop Periprosth. Acetabular fracture Experimental studies
• Ries et al
Small sized acetabulum underream by 1 Large sized acetabulum undreream by 3
• Series of 13 periprosthetic acetabular fracture
• 11 occurred in women above 60 with Rh. Arth.
• Quality of host bone important factor
• 4 fracture diagnosed pot op – 2 reqd revision and I case component migrated substantially
Tips to avoid Intraop Periprosth. Acetabular fracture
• Careful reaming avoiding violation of ant., post. Or medial wall.
• Failure of component to advance with progressive blows – additional reaming.
• Avoid underreaming > 2mm• Osteopenic bone – minimal underreaming /line
to line contact• Avoid overreaming around dome of prosthesis –
leads to fracture
Pelvic Discontinuity
• Separation of sup. portion of acetabulum from inf. portion
• Usually seen in cases of revision THR
Pelvic Discontinuity
• Radiological indicator - Transverse fracture line - Medial translation of inf. portion of
hemipelvis - break in ilioischial line - Rotation of inf hemipelvis - asymmetric obturator rings
Classification system
Intraop Periprosth. Acetabular fracture
• Recognize fracture occurred
• Assess – displaced / undisplaced
• Stability of implant
• X_ ray – Obturator and Iliac views
Intraop. Management
• Type IA
• Fracture involves the wall in Type IA
• Fracture undisplaced and component stable - Leave the component in place - Use adjunctive screws
Intraop. Management• Type IB - Fracture involving Column - Implant Unstable
• Remove component & Reduce fracture – internal fixation with plate and screws
• Line to line reaming • Implant Multihole acetabular cup
• Post op IA & IB – Toe touch weight bearing 6 – 12 weeks
Intraop. Management
• Type IC• Fracture not recognised intraoperatively
• Component migration postoperatively• Failure
Intraop. Management
• Type IC
• Trial of extended toe touch weight bearing• Early acetabular revision after discussion with pt.
• Failure rate Component fixed without screws Involvement of column Fracture displaced
Intraop. Management
• Pelvic Discontinuity• < 50% bone loss - Hemispherical porous coated acetabular cup - Posterior plate and screws - Morcellized bone graft at site of discontinuity
• > 50% bone loss – Acetabular reconstruction cage
Periprosth. Acetabular fracture Treatment Algorithm
Periprosth. Acetabular fracture Treatment Algorithm
Summarize
• Intraop periprosthetic acetbular frature complex injuries
• Implant should be stable
• Rigid fixation of fracture & bone grafting
• Assess remaining host bone
• Loss > 50% bone – Acetabular cage from ilium to ischium