High Yield Topics

Periprosthetic Fractures

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Ovid: Handbook of Fractures

Authors: Koval, Kenneth J.; Zuckerman, Joseph D.
Title: Handbook of Fractures, 3rd Edition
> Table of Contents > I – General Considerations > 6 – Periprosthetic Fractures

6
Periprosthetic Fractures
TOTAL HIP ARTHROPLASTY
Femoral Shaft Fractures
Epidemiology
  • Intraoperative: There is a 0.8% to 2.3% incidence overall, including cemented and uncemented components.
  • Postoperative: There is a 0.1% incidence.
  • They occur more frequently with
    noncemented components, with an incidence of 2.6% to 4% to as high as
    17.6% for noncemented revisions.
Risk Factors
  • Osteopenia: Osteoporosis or bone loss secondary to osteolysis.
  • Stress risers secondary to cortical defects.
  • Revision surgery.
  • Inadequate implant site preparation: Large implant with inadequate reaming or broaching may be responsible.
  • Pericapsular pathology: A scarred capsule with inadequate release may result in intraoperative fracture.
  • Loose components: Loose femoral components are responsible for up to 33% of periprosthetic femur fractures.
Surgical Considerations (to Avoid Periprosthetic Fracture during Revision Surgery)
  • Use longer-stem prosthesis, spanning twice the bone diameter beyond the defect.
  • Consider bone grafting the defect.
  • Place cortical windows in an anterolateral location on the femur in line with the neutral bending axis.
  • Leave cortical windows <30% of the bone diameter.
  • Choose the correct starting point for reaming and broaching.
Classification
JOHANSSON (FIG. 6.1)

Type I: Fracture proximal to the prosthetic tip with the stem remaining in the medullary canal
Type II: Fracture extending beyond the distal stem with dislodgement of the stem from the distal canal
Type III: Fracture entirely distal to the tip of the prosthesis
COOKE AND NEWMAN (MODIFICATION OF BETHEA)

Type I: Explosion type with comminution around the stem; prosthesis always loose and fracture inherently unstable
Type II: Oblique fracture around the stem; fracture pattern stable, but prosthetic loosening usually present
Type III: Transverse fracture at the distal tip of the stem; fracture unstable, but prosthetic fixation usually unaffected
Type IV: Fracture entirely distal to the prosthesis; fracture unstable, but prosthetic fixation usually unaffected
Figure 6.1. Classification scheme proposed by Johansson.

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AMERICAN ACADEMY OF ORTHOPAEDIC SURGEONS CLASSIFICATION
This divides the femur into three separate regions:

Level I: Proximal femur distally to the lower extent of the lesser trochanter
Level II: 10 cm of the femur distal to level I
Level III: Covers remainder of femur distal to level II

Type I: Fracture proximal to the intertrochanteric line that usually occurs during dislocation of the hip
Type II: Vertical or spiral split that does not extend past the lower extent of the lesser trochanter
Type III: Vertical or spiral split that
extends past the lower extent of the lesser trochanter but not beyond
level II, usually at the junction of the middle and distal thirds of
the femoral stem
Type IV: Fractures that traverse or lie
within the area of the femoral stem in level III, with type IVA being a
spiral fracture around the tip and type IVB being a simple transverse
or short oblique fracture
Type V: Severely comminuted fractures around the stem in level III
Type VI: Fractures distal to the stem tip, also in level III
Figure 6.2. American Academy of Orthopaedic Surgeons classification of fractures associated with hip arthroplasty.

(Modified from Petty W, ed. Total Joint Replacement. Philadelphia: WB Saunders, 1991:291–314.)

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VANCOUVER CLASSIFICATION

Type A: Fracture in the trochanteric region
AG: Greater trochanter region
AL: Lesser trochanteric region
Type B: Around or just distal to the stem
B1: Stable prosthesis
B2: Unstable prosthesis
B3: Unstable prosthesis plus inadequate bone stock
Type C: Well below the stem
Figure 6.3. Vancouver classification scheme for periprosthetic fractures about total hip arthroplasties.

(Modified from Duncan CP, Masri BA. Fractures of the femur after hip replacement. In: Jackson D, ed. Instructional Course Lectures 44. Rosemont, IL: American Academy of Orthopaedic Surgeons, 1995:293–304.)
Treatment Principles
  • Treatment depends on
    • Location of the fracture.
    • Stability of the prosthesis.
      • A loose stem should be revised.
    • Bone stock.
    • Age and medical condition of the patient.
    • Accurate reduction and secure fixation.
  • Options include:
    • Nonoperative treatment: limited weight bearing, brace, cast, or traction.
    • Open reduction and internal fixation (ORIF) (with plate and screws or cable and/or strut allograft).
    • Revision plus ORIF.

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VANCOUVER TYPE A FRACTURES
  • These are usually stable and minimally displaced.
  • ORIF is used to maintain abductor function with wide displacement.
  • Revision of acetabular component is indicated with severe polyethylene wear.
VANCOUVER TYPE B1 FRACTURES
  • These are usually treated with internal fixation.
  • Options for fixation include:
    • Wires or cables.
    • Plate and screws and/or cables.
    • Cortical onlay allograft.
    • Combination.
  • Long-term results depend on:
    • Implant alignment.
    • Preservation of the periosteal blood supply.
    • Adequacy of stress riser augmentation.
  • Routine bone graft is used with ORIF.
VANCOUVER TYPE B2 FRACTURES
  • Revision arthroplasty and ORIF are used.
  • Choice of implant includes:
    • Uncemented prosthesis:
      • Extensive coated long-stem curved prosthesis.
      • Fluted long-stem prosthesis.
    • Cemented prosthesis.
VANCOUVER TYPE B3 FRACTURES
  • No sufficient bone stock supports the revision prosthesis.
  • Options include:
    • Proximal femoral reconstruction.
      • Composite allograft.
    • Proximal femoral replacement.
  • Treatment depends on:
    • The age of the patient.
    • The severity of the bone defect.
    • The functional class of the patient.
VANCOUVER TYPE C FRACTURES
  • Treat independently of the arthroplasty.
  • Use a plate and screws and/or cables with or without a strut allograft.
  • Do not make any new stress riser.
Acetabular Fractures
  • Nondisplaced fractures should be observed
    and treated with crutches and limited weight bearing. There is a high
    incidence of late loosening of the acetabular component, requiring
    revision.
  • Displaced fractures should be treated by ORIF, and the component should be revised.

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TOTAL KNEE ARTHROPLASTY
Supracondylar Femur Fractures
Epidemiology
  • The postoperative incidence is 0.6% to 2.5%.
  • They generally occur within 10 years after surgery, usually secondary to relatively minor trauma.
  • Fracture of the patella after total knee arthroplasty may occur, with a prevalence of 0.1% to 8.5%.
Risk Factors
Supracondylar fractures after total knee replacement are multifactorial in origin, and risk factors include:
  • Osteoporosis.
  • Preexisting neurologic disease.
  • Notching of the anterior cortex:
    • Biomechanical analysis: 3 mm of anterior notching reduces torsional strength by 29%.
    • There is a high correlation between
      notching and supracondylar fractures in patients with rheumatoid
      arthritis and significant osteopenia.
    • In the absence of significant osteopenia, there is no correlation between notching and supracondylar fractures.
Classification
NEER, WITH MODIFICATION BY MERKEL

Type I: Minimally displaced supracondylar fracture
Type II: Displaced supracondylar fracture
Type III: Comminuted supracondylar fracture
Type IV: Fracture at the tip of the prosthetic femoral stem of fracture of the diaphysis above the prosthesis
Type V: Any fracture of the tibia
PERIPROSTHETIC FEMUR FRACTURES ABOUT TOTAL KNEES (LEWIS AND RORABECK)
This classification takes into account both fracture displacement and prosthesis stability (Fig. 6.4).

Type I: The fracture is nondisplaced, and the bone-prosthesis interface remains intact.
Type II: The interface remains intact, but the fracture is displaced.
Type III: The patient has a loose or failing prosthesis in the presence of either a displaced or a nondisplaced fracture.
Treatment
PRINCIPLES
  • Anatomic and mechanical alignment are critical.
  • Nondisplaced fractures may be treated nonoperatively.
  • ORIF is indicated if the alignment is unacceptable by closed means and if bone stock is adequate for fixational devices.
  • If bone quality is poor, the fracture
    should be treated nonoperatively, despite poor alignment, with clinical
    and radiographic reevaluation after healing.
  • Immediate prosthetic revision is indicated in selected cases.

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NONOPERATIVE TREATMENT
Figure 6.4. Classification scheme for periprosthetic fracture of the knee.

(Modified from Lewis PL, Rorabeck CH. Periprosthetic fractures. In: Engh GA, Rorabeck CH, eds. Revision Total Knee Arthroplasty. Baltimore: Williams & Wilkins, 1997:275–295.)
  • Long leg casting or cast bracing for 4 to 8 weeks may be used to treat minimally displaced fractures.
OPERATIVE TREATMENT
  • Displaced periprosthetic fractures around
    a total knee replacement are almost always managed with ORIF because of
    the difficulties in maintaining acceptable alignment after displacement.
    • A blade plate, dynamic condylar screw,
      dynamic compression plate, condylar buttress plate, locked plate, or
      retrograde intramedullary nailing may be used for operative
      stabilization.
    • Primary revision with a stemmed component may be considered if there is involvement of the bone-implant interface.
    • Bone loss may be addressed with autologous grafting.
    • Cases of severe bone loss, especially in
      the metaphyseal region, may be addressed with distal femoral
      replacement with a specialized prosthesis designed for oncology
      management.
  • Fractures around the diaphysis or the tip
    of a femoral component may be treated with cortical strut grafts and
    cerclage wiring, dynamic compression plate, locked plate, or a
    combination of techniques.
  • Acceptable alignment guidelines
    • Angulation <5 to 10° in either plane
    • <5 mm translation
    • <10-degree rotation
    • <1 cm shortening
Tibial Fractures
Risk Factors
  • Significant trauma (shaft fractures)
    Figure 6.5. Classification of periprosthetic tibial fractures.

    (Modified from Felix NA, Stuart MJ, Hansen AD. Periprosthetic fractures of the tibia associated with total knee arthroplasty. Clin Orthop 1997;345:113–124.)

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  • Tibial component malalignment associated with increased medial plateau stress fractures
  • Revision surgery with press-fit stems
Classification
PERIPROSTHETIC TIBIAL FRACTURES (FELIX et al)
  • Classification is based on three factors:
    location of the fracture, stability of the implant, and whether the
    fracture occurred intraoperatively or postoperatively (Fig. 6.5).

      Type I: Occur in the tibial plateau
      Type II: Adjacent to the stem
      Type III: Distal to the prosthesis
      Type IV: Involve the tubercle
  • The stability of the implant is then used to classify the fractures further:
    • Subtype A is a well-fixed implant.
    • Subtype B is loose.
    • Subtype C fractures are intraoperative.
Treatment
NONOPERATIVE TREATMENT
  • Closed reduction and cast immobilization may be performed for most tibial shaft fractures after alignment is restored.
  • Early conversion to a cast brace to preserve knee range of motion is advised.
OPERATIVE TREATMENT
  • Periprosthetic tibial fractures not
    involving the plateau require ORIF if closed reduction and cast
    immobilization are unsuccessful.
  • Type I fractures involving the tibial
    plateau typically involve the bone-implant interface, necessitating
    revision of the tibial component.

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Patella Fractures
Epidemiology
  • The postoperative incidence is 0.3% to 5.4% (reported as high as 21%).
Risk Factors
  • Large, central peg component
  • Excessive resection of the patella during prosthetic implantation
  • Lateral release, with devascularization of the patella
  • Malalignment
  • Thermal necrosis (secondary to methylmethacrylate)
Classification
GOLDBERG

Type I: Fractures not involving cement/implant composite or quadriceps mechanism
Type II: Fractures involving cement/implant composite and/or quadriceps mechanism
Type IIIA: Inferior pole fractures with patellar ligament disruption
Type IIIB: Inferior pole fractures without patellar ligament disruption
Type IV: Fracture-dislocations
Treatment
NONOPERATIVE TREATMENT
  • Fractures without component loosening,
    extensor mechanism rupture, or malalignment of the implant (type I or
    IIIB) may be treated nonoperatively.
  • The patient may be placed in a knee immobilizer for 4 to 6 weeks, with partial weight bearing on crutches.
OPERATIVE TREATMENT
  • Indicated for patients with disruption of the extensor mechanism, patellar dislocation, or prosthetic loosening.
  • Treatment options include:
    • ORIF with revision of the prosthetic patella. This is indicated for type II, IIIA, and IV fractures.
    • Fragment excision: This may be undertaken for small fragments that do not compromise implant stability or patellar tracking.
    • Patellectomy: This may be necessary in cases of extensive comminution or devascularization with osteonecrosis.
    • Surgical considerations include adequate
      medial arthrotomy, adequate lateral release, preservation of the
      superior lateral geniculate artery, and preservation of the patellar
      fat pad.
TOTAL SHOULDER ARTHROPLASTY
Epidemiology
  • Periprosthetic fractures of the shoulder complicate approximately 2% of cases.

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Risk Factors
Figure
6.6. Classification of periprosthetic shoulder fractures. Type I:
fractures occurring proximal to the tip of the prosthesis. Type II:
fractures occurring in the proximal portion of the humerus with distal
extension beyond the tip of the prosthesis. Type III: fractures
occurring entirely distal to the tip of the prosthesis. Type IV:
fractures occurring adjacent to the glenoid prosthesis.

(From Bucholz RW, Heckman JD, eds. Rockwood and Green’s Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002:587.)
  • Excessive reaming of the proximal humerus
  • Overimpaction of the humeral component
  • Excessive torque placed on the humerus during implant insertion
Classification
University of Texas San Antonio Classification of Periprosthetic Shoulder Fractures (Fig. 6.6)

Type I: Fractures occurring proximal to the tip of the humeral prosthesis
Type II: Fractures occurring in the proximal portion of the humerus with distal extension beyond the tip of the humeral prosthesis
Type III: Fractures occurring entirely distal to the tip of the humeral prosthesis
Type IV: Fractures occurring adjacent to the glenoid prosthesis
Treatment
  • Controversial: Some advocate nonoperative
    treatment with surgical intervention indicated for compromise of
    prosthetic fixation and intraoperative fractures. Others advocate
    aggressive operative stabilization of all periprosthetic fractures of
    the shoulder.
Nonoperative Treatment
  • Closed treatment involves fracture brace,
    isometric exercises, and early range-of-motion exercises until
    radiographic evidence of healing.

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Operative Treatment
  • Primary goals include fracture union, prosthesis stability, and maintenance of motion.
  • ORIF may be performed with cerclage wiring and possible bone grafting.
  • Revision to a long-stem prosthesis may be required for cases with gross implant loosening.
  • Options for postoperative immobilization
    range from sling immobilization for comfort until range-of-motion
    exercises can be instituted, to shoulder spica casting for 6 weeks in
    cases of tenuous fixation.
TOTAL ELBOW ARTHROPLASTY
Epidemiology
  • The overall prevalence of periprosthetic fractures of the elbow is approximately 8%.
  • Most fractures are preceded by prosthetic
    loosening and thinning of the cortices. These occur more commonly in
    the humerus than in the ulna.
Risk Factors
  • Osteoporosis
  • Paucity of bone between the medial and lateral columns of the distal humerus
  • Abnormal humeral bowing in the sagittal plane
  • Size and angulation of the humeral and ulnar medullary canals
  • Excessive reaming to accommodate the prostheses
  • Revision elbow surgery
Classification (Fig. 6.7)

Type I: Fracture of the humerus proximal to the humeral component
Type II: Fracture of the humerus or ulna in any location along the length of the prosthesis
Type III: Fracture of the ulna distal to the ulnar component
Type IV: Fracture of the implant
Treatment
Nonoperative Treatment
  • Nondisplaced periprosthetic fractures
    that do not compromise implant stability may be initially addressed
    with splinting at 90 degrees and early isometric exercises.
  • The splint may then be changed to a fracture brace for 3 to 6 weeks.
Operative Treatment
  • Displaced type I or type II fractures may
    be managed with ORIF with cerclage wire fixation, or with plates and
    screws. Alternatively, revision to a long-stem humeral component may be
    performed, with the component extending at least two diameters proximal
    to the tip of the implant. Supplemental bone grafting may be used as
    necessary.

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  • Type III fractures are usually amenable to cerclage wiring.
    Figure
    6.7. Classification of periprosthetic elbow fractures. Type I:
    fractures of the humerus proximal to the humeral component. Type II:
    fractures of the humerus or ulna in any location along the length of
    the prosthesis (including those fractures that extend proximal and
    distal to the humeral and ulnar components, respectively). Type III:
    fracture of the ulna distal of the ulnar component. Type IV: fracture
    of the implant.

    (From Bucholz RW, Heckman JD, eds. Rockwood and Green’s Fractures in Adults, 5th ed. Baltimore: Lippincott Williams & Wilkins, 2002:601.)
  • If stable fixation of implant components cannot be obtained, consideration should be given to more constrained prostheses.
  • Type IV fractures require component revision.
  • Displaced olecranon fractures should be fixed with a tension band and cement.

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