Advantages of Cementless MiniIncision THA

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Advantages of CementlessMini-Incision THA

• Todd V. Swanson, M.D.
• Las Vegas, Nevada

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Cemented THA

• Considered the Gold Standard for years
• Good long-term results in elderly patients

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Cemented THA Results(Charnley Long-term Results)
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Mid-term Cemented THA Results(2nd 3rd
Generation Cement Technique)
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Cemented THA in Young Patients (1st generation
cement technique)
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Introduction of Porous Ingrowth Fixation in USA

• Early 1980s
• Many poor designs
• Many early failures
• Loosening
• Osteolysis
• Thigh pain

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Cementless THA Results(conventional designs)
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Cementless THA Results(Conventional Designs)
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Cementless THA Results

• Not all cementless hips are created equal
• Comparisons should not be between any cemented
  and cementless designs, but between optimal
  designs utilizing optimal technique

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Cementless THA Results(Norwegian Arthroplasty
Register)(Havelin, et al, J. Bone Joint Surg.
77-B11, 1995)

• 2907 cementless hips
• 8 designs with gt100 each
• Group 1 (all titanium)
• Zweymuller
• Corail
• LMT
• Profile
• Group 2
• Bio-Fit
• Harris Galante
• Femora
• PM-Prosthesis

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Cementless THA Results(Tapered Designs)
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Zweymuller Results
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A substantial incidence of thigh pain has been
noted by a variety of authors using femoral
designs with a large intramedullary rod. In
contrast, the use of a flat wedge-shaped femoral
implant has resulted in a considerably lower
incidence of thigh pain in the authors own
experience and that of others--Rothman, Clin
Orthop, 1990--
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Cemented vs Cementless Results
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Cemented vs Cementless Fixation

• Mid-term results are comparable when using
  optimal designs and implantation techniques

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The Quintessential Question

• Will the dynamic, biologic fixation of cementless
  THA outlast the static, mechanical fixation of
  cemented components?
• Answer Only time will tell

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Are there any Early Advantages to cementless
fixation?

• Peri-operative morbidity?
• Peri-operative mortality?
• Operative time?
• Blood loss?
• Length of Stay?
• Cost?

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Operative Time(Barrack, et al, J. Arthroplasty
11373, 1996)

• 50 stratified THAs
• 25 cemented 3rd generation cement technique
• 25 cementless
• Operative time 20 minutes longer for cemented
  implants
• (OR time 8 per minute) x 20 160
• Plus additional anesthesia charge of 100

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Operative Time(Laupacis, Bourne, Rorabeck, et
al,J. Arthroplasty 9481, 1994)

• Cost analysis of 60 THAs during 1st post-op year
• 30 Biomet cemented
• 30 Biomet cementless
• Operative time 25 minutes longer for cemented
  implants
• (OR time 6 per minute) x 25 150

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Operative Time

• Bourne, Rorabeck, J. Arthroplasty, 1994
• Operative time 25 minutes longer for cemented
  hips
• Equivalent to 150 per case

• Barrack, J. Arthroplasty, 1996
• Operative time 20 minutes longer for cemented
  hips
• Equivalent to 260 per case

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Cost(Barrack, et al, J. Arthroplasty 11373,
1996)

• 50 stratified THAs (25 cemented, 25 cementless)
• Cementless prosthesis cost 900 more than
  cemented
• Cementing accessories 700
• Extra OR time cost 260
• Overall costs equivalent

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Cost(Laupacis, Bourne, Rorabeck, et al,J.
Arthroplasty 9481, 1994)

• Cost analysis of 60 THAs during 1st post-op year
  (30 cemented, 30 cementless)
• No difference in overall cost during
  hospitalization or during 1st post-op year

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Cost

• Bourne, 1994
• No difference in overall cost during
  hospitalization or 1st post-op year

• Barrack, 1996
• Overall operative costs equivalent between
  cemented vs cementless hips

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Conclusions(cost OR time)

• Costs of cemented vs cementless THA equivalent
• OR time shorter with cementless THA (particularly
  with Zweymuller prosthesis and abbreviated
  posterior approach)

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Morbidity Pulmonary Embolism(Sharrock, Ranawat,
Sculco, Salvati, et al,Clin. Orthop. 31916,
1995)

• 13 elective bilateral THAs studied with
  intra-operative pulmonary artery catheters
• 8 cemented
• 5 cementless
• Increased pulmonary artery pressure in cemented
  group only, indicating intra-operative pulmonary
  embolism

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Morbidity Pulmonary Embolism(Christie, et
al,J. Bone Joint Surg. 76-B409, 1994)

• Intra-operative trans-esophageal echocardiography
  performed on 20 femoral neck fractures
• 10 uncemented Austin-Moores
• 10 cemented endoprostheses (finger packing of
  cement)
• Greater and more prolonged embolic cascades in
  cemented group

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Morbidity Pulmonary Embolism(Ereth, Lewallen,
et al,Mayo Clin. Proc. 671066, 1992)

• Trans-esophageal echocardiography and hemodynamic
  monitoring in 35 THAs
• 19 cemented
• 16 uncemented
• Cemented group
• Greater pulmonary embolization
• Increased pulmonary artery pressure and PVR
• Decreased cardiac output

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Morbidity Pulmonary Embolism(Ries, et al, J.
Bone Joint Surg. 75-A581, 1993)

• Arterial oxygenation followed intra-operatively
  in 34 THAs
• 11 cemented (3rd generation technique)
• 23 cementless
• 28 increase in intra-operative pulmonary shunt
  in cemented group no change in cementless group

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Morbidity Pulmonary Embolism(Nolan, Anaesthesia
49293, 1994)

• pO2 and blood pressure monitored during THAs
• 10 cemented THAs
• 16 reduction in pO2
• 20 reduction in mean B.P.
• 10 Cementless THAs no change in pO2 or B.P.

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Morbidity Pulmonary Embolism(Orsini, Waddell,
et al,J. Bone Joint Surg. 69-A822, 1987)

• 24 dogs studied
• non-cemented group
• cemented group
• non-cemented, with bone wax
• Cemented and bone wax groups
• Pulmonary microemboli
• Increased pulmonary artery pressure
• Increased intra-pulmonary artery shunt
• Decreased arterial pO2

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ConclusionsPulmonary Embolism

• Pressurization causes embolization of debris and
  fat to lungs
• Pulmonary embolization causes
• Increased pulmonary artery pressure
• Increased pulmonary vascular resistance
• Decreased cardiac output
• Increased pulmonary shunt
• Oxygenation difficulties

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Pulmonary Embolism(numerous studies)

• Cement pressurization can elevate intramedullary
  pressures up to 5,800 mm Hg and expel 2g of
  debris into the vasculature
• Debris, fat, and bioactive substances embolize to
  the lungs
• Pulmonary embolization causes
• Increased pulmonary vascular resistance
• Increased pulmonary artery pressure
• Decreased cardiac output
• Increased pulmonary shunt
• Oxygenation difficulties

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Fat Embolism after Cementless THA
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Fat Embolism after Cementless THA(Gelinas, J.
Arthroplasty, 2000)

• Tight, cylindrical fit can cause intramedullary
  pressurization and embolization of intramedullary
  debris

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Morbidity DVT(Sharrock, Ranawat, Sculco,
Salvati, et al,Clin. Orthop. 31916, 1995)

• 34 THAs monitored intra-operatively for
  circulating markers of thrombogenesis
• 21 cemented
• 13 cementless
• Circulating markers of thrombin generation and
  fibrinolysis increased more during cemented
  femoral component insertion than cementless
  insertion

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Morbidity DVT(Francis, Marder,
Evarts,Lancet, April 5, 1986, p. 769)

• 46 THAs followed prospectively
• 13 cemented (3rd generation technique)
• 23 cementless
• Venography 1 week post-op
• 31 DVTs in cemented group none in cementless
  group (plt0.025)

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ConclusionsDVT

• Cement pressurization causes release of
  thrombogenic agents
• Some studies document clinically increased risk
  of DVT with cemented arthroplasty

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Deep Venous Thrombosis(HSS, Clin Orthop,
1995Francis, Lancet, 1986)

• Cement pressurization causes release of
  thrombogenic agents
• Some studies document clinically increased risk
  of DVT with cemented arthroplasty

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Mortality(Lennox McLauchlan,Injury 24185,
1993)

• 207 consecutive femoral neck fractures
• Cemented vs cementless hemiarthroplasties
• Higher mortality in cemented group during initial
  48 hours (4 vs 0)
• 3 myocardial infarctions
• 2 fat embolism
• 1 pulmonary embolus

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Mortality(Johnson Lewallen,Orthop. Trans.
19224, 1995)

• Review of 976 elective endoprostheses
• 20 mortalities w/i first 30 days
• Higher mortality with cemented vs cementless
  endoprosthesis (3 vs 0.3)

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Mortality(Lewallen, unpublished data, 1992)

• Review of 21,895 THAs
• 15,211 cemented
• 6684 cementless
• 19 intra-operative deaths in cemented group
  (0.12) none in cementless group (plt0.05)

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ConclusionsMortality

• Cemented endoprosthesis for femoral neck
  fractures may increase mortality rate in first 48
  hours
• Elective cemented endoprosthesis may increase
  mortality rate in first 30 days
• Cemented THA may increase mortality rate

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Mortality(Lennox, Injury, 1993 Johnson, Orthop
Trans, 1995 Lewallen, 1992)

• Cemented endoprosthesis for femoral neck
  fractures may increase mortality rate in first 48
  hours (4 vs 0 in 207 patients)
• Elective cemented endoprosthesis may increase
  mortality rate in first 30 days (3 vs 0.3 in
  976 patients)
• Cemented THA may increase mortality rate (0.12
  vs 0 in 21,895 THAs)

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SummaryEarly Advantages of Cementless Fixation

• Shortened operative time
• Decreased pulmonary morbidity
• Decreased thromboembolism
• Decreased mortality

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Hybrid vs Zweymuller THAEarly Post-op
Complications(a prospective study with
historical controls)

• 51 hybrid THAs
• Standard posterior approach
• 3rd generation cement technique
• Richards or DePuy cemented stem
• Richards cementless cup

• 268 cementless THAs
• Abbreviated posterior approach (mini-incision)
• Plus Zweymuller stem
• Richards or Plus cementless cup

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Abbreviated Posterior Approach
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Study Methods

• Study groups matched by excluding all patients
  lt60 y.o.
• 94 osteoarthritics
• General anesthesia
• PCA analgesia until 2nd POD
• Immediate weight bearing as tolerated
• Mechanical DVT prophylaxis ASA

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Hybrid vs ZweymullerMean Age

• 48 hybrid hips
• 172 Zweymuller hips
• No difference in mean age
• Hybrid 70.3 (60-83)
• Zweymuller 71.5 (60-94)

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Hybrid vs ZweymullerMean Operative Time

• Hybrid 79 minutes (46-111)
• Zweymuller 50 minutes (23-110)
• 29 minute difference (hybrids took 58 longer)

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Hybrid vs ZweymullerMean Blood Loss

• Hybrid 450 cc (200-1000)
• Zweymuller 301 cc (100-2000)
• 149 cc difference (50 more blood loss with
  standard approach)
• (No statistical difference in blood replacement)

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Hybrid vs ZweymullerDifficult Pain
Management(deviation from standard analgesic
regimen)

• Hybrid 8
• Zweymuller 0

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Hybrid vs ZweymullerPost-op O2 Requirements

• Hybrid 10 required O2 past POD-1
• Zweymuller 1.4 required O2 past POD-1

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Hybrid vs ZweymullerMental Status
Changes(Confusion, Agitation, Disorientation)

• Hybrid 6.2
• Zweymuller 2.3

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Hybrid vs ZweymullerAll Peri-operative
Complications

• Complications Included
• Bleeding
• Pneumonia
• Cardiac problem
• Ileus
• Dislocation
• Urinary retention/UTI
• DVT/PE
• Wound problem
• Mental status changes
• Difficult pain management
• Miscellaneous
• Hybrid 22 of patients
• Zweymuller 4.2 of patients

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Hybrid vs ZweymullerMean Length of Stay

• Acute Days
• Hybrid 5.0 days
• Zweymuller 4.0 days
• Total Days
• Hybrid 9.1 days
• Zweymuller 6.8 days
• Acute days plt0.005
• Total days plt0.025

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ConclusionsZweymuller Total Hip Stem with
Abbreviated Posterior Approach

• Less blood loss
• Shorter operative time
• Less pain
• Fewer post-op mental status changes
• Fewer total peri-operative complications
• Shorter length of stay

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Reasons to use Cementless Fixation with
Abbreviated Approach

• Less pulmonary morbidity
• Less thromboembolism
• Lower mortality
• Shorter OR time
• Less blood loss
• Fewer mental status changes
• Less post-op pain
• Fewer overall complications
• Shorter hospital length of stay

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Etiologies of Differences

• Shorter operative time
• Mini-incision
• Simplified prosthesis insertion
• Less blood loss
• Mini-incision
• Shortened OR time
• Less pain
• Mini-incision
• Mental Status Changes
• Cementless fixation
• Less anesthesia
• Fewer pain meds

• Fewer total peri-operative complications
• Mini-incision
• Shorter OR time
• Cementless fixation
• Fewer pain meds
• Less blood loss
• Shorter length of stay
• Mini-incision
• Immediate weight-bearing
• Fewer complications

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THANK-YOU
Todd V. Swanson, MD Las Vegas, Nevada, USA