Periprosthetic Hip Fractures

Acetabular

Femoral

Intraoperative

• More common with cementless stems
• Primary THR 0.1-4%
  • Primary cemented: 0.1%
  • Primary uncemented: 3.9%
• Revision THR 2-14%
  • Revision cemented: 1.9
  • Revision uncemented: 14 [1]

Postoperative

• Overall incidence after primary THA: 0.6%
  • Primary cemented: 0.6%
  • Primary uncemented: 0.4%
• Overall incidence after revision THA: 2.4%
  • Revision cemented: 2.8%
  • Revision uncemented: 1.5% [1]
• Most often due to ground-level fall
• Increased risk with implant loosening and associated osteolysis

Classification

• Duncan & Masri Classification (Vancouver classification)
  • A : Trochantericfracture
    • AG : Greater trochanter
    • AL : Lesser trochanter
  • B : Fracture around stem or just distal to stem tip
    • B1 : Well-fixed stem
    • B2 : Loose stem + good bone stock
    • B3 : Loose stem + poor bone stock
  • C : Fracture well distal to stem tip
    

    Vancouver B2

Prevention

• Better than the most successful treatment option
• Avoid cortical defects
• Avoid malalignment of prosthesis
• Regular radiological follow-up to detect early loosening and osteolysis
• 65% unsatisfactory results so these fractures are better prevented than treated

Treatment

Depends on location of fracture and whether component is well fixed or not

Initial management may require Buck’s traction or skeletal traction. Traction pin should be placed in the tibia to avoid a nidus for infection in the femur.

• Treatment according to Vancouver Classificaion:
  • • Intraoperative
      • Nonsidplaced fractures of the greater trochanter can be treated with protected weight bearing and an abduction brace or surgically with a fixation device.
      • Calcar fractures should be stabilized with cerclage cable(s) prior to final insertion of the implant. If stable fixation cannot be achieved with a proximal fixation stem, a stem that provides distal fixation should be used.
      • Displaced fractures: ORIF with trochanteric claw, trochanteric cabe plate, or wires
    • Postoperative
      • Usually stable and needs conservative treatment and NWB
      • Markedly displaced fractures may require trochanteric claw or cerclage fixation
  • B1
    • Options:
      • Plate-cerclage fixation combination
        • may augment with cortical allograft onlay struts (e.g. plate with proximal cable fixation and anterior or medial strut)
      • Two or three cortical struts with three cerclage cables above and below fracture site
      • Lateral locked plating
    • Less viable options:
      • Cerclage fixation alone is inadequate
      • Dynamic compression plates with unicortical screws is inadequate
  • B2
    • Revision to long, uncemented stem (typically extensively porous coated or fluted tapered modular stems)
      • In addition to poor track record of cemented stems in revision THA, the cement may also enter the fracture site and slow healing.
    • Consider cerclage fixation ± strut graft for stabilization of fracture
  • B3
    • Long stem revision and impaction grafting as necessary
    • If severe osteolysis or comminution:
      • Allograft prosthetic composite
      • Tumor endoprosthesis
  • • Lateral plate
      • Overlap stem by at least two cortical diameters
    • Retrograde IM nail

Prognosis

• Reduced function 30%
• Non-union 30%
• Malunion 30%
• Plate failure 15%
• Infection 8%
• Dislocation 8%
• Aseptic loosening 8-30%

Trochanteric nonunion and migration

• Incidence 3 – 8% in primary THR
• More than 2 cm migration significantly impairs abductor function
• Less problems with trochanteric slide regarding abductor function
• Nowadays trochanteric osteotomy is seldom done except in :
  • Some patients with DDH
  • Protrusio acetabuli
  • Conversion arthroplasty from arthrodesis
• Variations
  • Stable fibrous union with good function and little pain, witout proximal migration
  • Pseudoarthrosis (known by painful resistance to abduction)
  • Migration >2 cm

Aetiology

• Small trochanteric fragment
• Poor-quality bone
• Inadequate initial fixation
• Reattachment under excessive tension
• Prior radiation therapy to the hip
• Patient noncompliance during the postoperative period

Clinical

• More prone to fatigue
• Trendelenburg gait
• Higher chance of dislocation
• May have bursitis ue to trochanteric broken wires
• Delayed sciatic palsy may result from migrated broken trochanteric wires
• Arthrosis also may occur, because of metal debris from braided cables

Treatment

• Not indicated in stable, non displaced, asymptomatic fibrous union
• Careful preparation and contouring of the GT is essential to obtain maximal stability
• The trochanter must not be reattached under excessive tension (not >15º abduction)
• Place the trochanter against bone rather than cement
• Options
  • Reattachment of the greater trochanter by wire fixation
  • Double cross-over wire with a compression spring
  • Abductors subperiosteal release from their origin on the iliac wing
• Weight-bearing and active abduction exercises are delayed until bony union
• A period of bracing in abduction or spica cast application recommanded

References:

1. Berry, D.J. Epidemiology: Hip and knee. In Duncan, C.P.; Callaghan, J.J. eds. Periprosthetic Fractures After Major Joint Replacement. Philadelphia, W.B Saunders, 1999, pp. 183-190.

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