Postoperative Complications of Total Hip and Total Knee Arthroplasty

1
Postoperative Complications of Total Hip and
Total Knee Arthroplasty

• Presented by Spencer F. Schuenman, D.O.

2
Postoperative Complications of Total Hip
Arthroplasty

• Wound Infection
• Dislocation
• Ectopic Bone
• Thromboembolic Disease
• Nerve Palsies, Limb Length Inequality, Osteolysis

3
Postoperative Deep Wound Infection

• Late infection is difficult to diagnose during
  the first hospitalization, particularly when
  prophylactic antibiotics have been administered.
  Late infection is the most serious complication
  which can follow total prosthetic replacement and
  is a catastrophe for both surgeon and patient...
  M. E. Mueller, 1970

4
Incidence

• Initial experience
• Sir John Charnley experienced initially deep
  sepsis with THA in 8.9 percent of cases.
• Wilson 11.0 percent
• Patterson 8.0 percent
• Mueller 4.0 percent
• Current experience
• Charnley 0.61 percent
• Lidwell 1.3 percent
• Fitzgerald 0.51 percent
• Schutzer 0.38 percent
• Salvati 1.4 percent
• Factors thought to influence wound infection
• presence or absence of unidirectional airflow
• perioperative antibiotic use
• use of major bone grafting
• development of post op hematomas
• previous hip operations
• prolonged OR times

5
Diagnosis

• Laboratory Assessment
• Diagnosis rests on the isolation of the
  microorganism(s) from several clinical tissue
  specimens from about the hip.
• A high suspicion should be present in patients
  with persistent pain.
• 54 had an elevated ESRgt 30mm/hr
• 44 had a fever
• 15 had leukocytosis
• All had pain in their infected hip
• Radiographic clues
• progressive radiolucency at the bone-cement
  interface or endosteal scalloping
• Periosteal new bone formation surrounding a
  prosthesis is pathognomonic
• Arthrography-true value is that aerobic and
  anaerobic cultures can be obtained by aspiration.
• Indium-labeled-leukocyte technique-if negative
  highly unlikely sepsis is present.

6
Clinical Features-Three Stages

• Stage I-symptoms appear within first three months
• Febrile course often observed
• Usually an infected hematoma beneath fascia
• Spontaneous drainage is common
• Some progress from an initial superficial
  infection
• Stage II-six to 24 months
• Absence of pain-free interval after surgery
• creeping, indolent progression
• febrile course unusual
• Stage III-beyond 24 months
• Long asymptomatic interval after arthroplasty
• acute onset of pain beyond 24 months
• febrile illness common at onset of delayed
  symptoms
• distant focus of infection often difficult to
  ascertain

7
Microbiology

• Predominantly Staphylococcus epidermidis and
  aureus
• Streptococcus viridans
• Group-D Streptococcus
• E. Coli
• Low virulence organisms 70
• Virulent organisms 25

8
Treatment

• Acute infection-debridement and 4 weeks of
  parental therapy can occasionally be effective
• Mainstay of therapy-resection arthroplasty with a
  one, two, or three stage reconstructive
  procedure.
• Low virulent organism-reconstruction can be
  performed as early as three months after
  resection and antibiotics
• High virulence-12 months or more

9
Postoperative Dislocation

• Second in frequency to loosening as causes of
  instability post op
• It may necessitate prolonged hospitalization,
  rehabilitation, and functional impairment

10
Incidence

• The literature reports a wide range of incidence
  figures for this problem.
• Review of 16 reports from 1973 through 1987 of
  over 35,000 procedures, there were just over 800
  dislocations for a rate of 2.23.

11
Mechanism

• There are two mechanisms that are well recognized
  by the clinician to place the hip at risk
• 1. Flexion, adduction, and internal
  rotation-results in posterior dislocation
• 2. Less common-extension, adduction, external
  rotation-results in anterior dislocation and is
  most frequently seen after an anterior approach
  and when excessive anteversion in imparted.

12
Risk Factors

• Preoperative Factors
• Age and Sex-mean age who dislocate was 64 yo.
• Height and Weight-only speculative conclusions at
  present
• Bilateral Procedures-no difference was found
• Underlying Diagnosis-no correlation with preop Dx
  and postop dislocation. Even congenital hips
  does not show a definite correlation to
  instability.
• Prior Surgery-this plays a significant role in
  subsequent hip instability.
• Perioperative Factors
• Surgical approach-the posterior approach is
  statistically at a greater risk for instability
  than the anterior approach.
• Aftercare-No effect in postop management was
  noted to increase instability.
• Component Head Size-no correlation can be found
  between head size and prosthetic instability.
• Range of Motion-hips with increased ROM have a
  greater tendency for instability due to the
  levering action of the femoral neck on the
  acetabulum.
• Limb Length Inequality-literature suggests a
  possible but relatively minor correlation between
  leg length and instability.
• Component Orientation-some consider acetabular
  orientation to be the most sensitive variable in
  predisposing to hip dislocation. Excessive
  femoral anteversion can also be a predisposing
  factor.
• Trochanter-trochanteric osteotomies can lead to
  nonunion which increases instability.

13
Treatment

• Nonoperative Treatment-successful in two-thirds
  of patients.
• Operative Treatment-only 1 in 100 patients who
  underwent THA will come to revision surgery
  directed at instability
• posterior dislocation is most common so an
  enhanced posterior wall of the acetabulum should
  increase stability.
• trochanteric advancement
• cross flap capsuloplasty

14
Ectopic Bone Formation

• Classification Systems
• Class I Islands of bon within the soft tissues
  about the hip.
• Class II Bone spurs from the pelvis or proximal
  end of the femur, leaving at least 1 cm between
  opposing bone surfaces.
• Class III Bone spurs from the pelvis or
  proximal end of the femur, reducing the space
  between opposing bone surfaces to less than 1 cm.
• Class IV Apparent ankylosis of the hip.

15
Incidence and Predisposing Factors

• Varies between 20 and 80, but only significant
  in 5 to 10 of hips.
• History of ankylosing spondylitis
• Men with hypertrophic osteoarthritis
• Previously developed ectopic bone secondary to
  previous surgeries

16
Prevention of Ectopic Bone

• Surgical prevention
• Good surgical technique
• remove all bone dust and debris
• minimize trauma to the abductor and adductor
  groups
• reduce incidence of hematoma formation by
  adequate drainage
• contain bone graft material so that it wont
  migrate into the soft tissues
• postoperative prevention
• Irradiation-low dose
• use of diphosphonates
• NSAIDS

17
Thromboembolic Disease

• The primary goal of DVT prophylaxis is the
  prevention of PE

18
Pathogenesis

• Described by Virchow over 100 years ago, known as
  Virchows triad
• 1. enhanced blood coagulation
• 2. vessel wall injury
• 3. altered blood flow

19
Diagnosis

• Reliance on clinical symptoms is well known to be
  inaccurate for the diagnosis of either DVT or PE.
• Venography-remains the gold standard for Dx of
  DVT
• It is invasive, expensive, and associated with
  complications
• Doppler-highly variable because of the subjective
  nature of its interpretation. Limited in
  diagnosing DVTs in the calf.
• safe, rapid, simple, and inexpensive
• 125I Fibrinogen-sensitive for calf DVT, but
  missed proximal DVTs due to labeled fibrinogen in
  the wound area.
• Compression Duplex Ultrasonography-very specific
  for proximal DVTs, but insensitive for smaller
  DVTs. Also interpreter dependent.
• Impedance Plethysmography-uses the
  electrolyte-rich blood to measure conduction.
  Highly sensitive and specific in clinically
  suspected DVT of the proximal thigh but less so
  with isolated calf DVTs.

20
Prophylaxis

• The primary goal is to prevent fatal pulmonary
  embolism.

21
Methods of Prophylaxis

• Nonpharmacologic
• Early Ambulation and Graduated Compression
  Stockings
• Intermittent Sequential Pneumatic Compression
• Type of Anesthesia-spinal is associated with
  significantly fewer postoperative DVT than with
  general or epidural.
• Pharmacologic
• Heparin (minidose)-no prolongation of APTT.
• Low-Molecular-Weight Heparin-inhibits factor X,
  does not inhibit platelet aggregation.
• Warfarin- inhibits factors II, VII, IX, X and
  proteins C and S
• Adjust to 1.25-1.50 times normal by the third
  postop day
• increased bleeding complications with PT gt1.5
  times
• Aspirin-inhibits platelet aggregation

22
Other Postop Complications

• Nerve Palsies-due to revision surgery, limb
  lengthening, anticoagulation postop, vascular
  insufficiency, women gt men.
• Prevention-avoid lengthening gt 4cm, careful
  monitoring of anticoagulation, good technique.
• Limb Length Inequality-more important to
  establish stability than to overcome a leg length
  discrepancy.
• Osteolysis-a process of softening, absorption,
  and destruction of bony tissue demonstrated on
  x-ray by a progressive radiolucent line or cavity
  at the bone-cement or bone-implant interface
• MUST RULE OUT INFECTION!