- Readmission rates following total hip arthroplasty are a concern due to financial penalties for physicians and hospitals. General anesthesia, obesity, and medical complications increase readmission risk. - Spinal anesthesia reduces readmission rates compared to general anesthesia. Blood conservation strategies like tranexamic acid administration can decrease transfusion needs. - Larger femoral head sizes are associated with increased revision rates for metal-on-metal bearings due to higher metal ion levels. Modularity in hip implants can cause complications like corrosion, fractures, and dissociation. - Surgeons must understand risks and utilize techniques like appropriate implant selection and infection prophylaxis to improve outcomes following total hip replacement.

1. What’s New in Hip
Replacement
James T. Ninomiya, MD, MS, John C. Dean, MD, and
Stephen J. Incavo, MD
Specialty Update
J Bone Joint Surg Am. 2015

2. Introduction
• Many changes in hip replacement have occurred during the
past year, with new information reported on implants,
materials, and surgical approaches
• Surgeons will always be expected to produce excellent
clinical results, there are now additional pressures to
• minimize the costs of the procedure
• decrease complications
• reduce the readmission rate

3. Outcomes of Hip Replacement Surgery
Readmission Rates
• Both physicians and hospitals may incur financial penalties,
readmissions following total hip arthroplasty are a growing area
of concern
Major factors that influenced these readmissions:
• longer index length of stay
• use of blood transfusions
• general anaesthesia
• anemia
• anticoagulation status prior to index admission

4. Surgeons should take
• an active role in identifying patients at higher risk for
perioperative medical and surgical complications
• work closely with the patients and their families in counselling

5. Factors and Practices That May Alter Outcomes and
Complications Following Total Hip Replacement
Spinal Anaesthesia Compared with General Anaesthesia :
• Hip replacement with general anaesthesia had three times the
proportion of readmissions
Medical complications following general anaesthesia included
• an increased risk for cardiac arrest
• Stroke
• blood transfusions

6. Obesity
• Patients with a body mass index of ≥40 kg/m2 had a
significantly increased risk of complications
• Surgeons should counsel patients regarding the increased
risks associated with obesity

7. Obstructive Sleep Apnea
• Higher rates of acute renal failure, as well as low oxygen blood levels
and longer hospitalization after surgery
• Increased risk of postoperative myocardial infarction and other cardiac-
related events
• More likely to need ventilator support
• Preoperative screening using STOP-BANG
• Minimizing the use of narcotics

9. Transfusion and Blood Management
Blood conservation strategies such as preoperative autologous
donation, blood salvation devices, and erythropoietin administration
Tranexamic acid decreases the need for transfusion when used either
intravenously or topically
Intra-articular administration at the surgical site is as effective as
intravenous dosing, with less potential for systemic complications

10. Tranexamic Acid Total Hip or Knee Arthroplasty
Clinical Recommendations( DEC 2014)

11. Suction Drainage Following Total Hip
Replacement
• Use of a drain increased the mean cost
• Increased the length of stay
• Rate of blood transfusions
• Overall, the routine use of a drain, even when used for
reinfusion of shed blood, provides little to no benefit

12. Venous Thromboembolism Prophylaxis
• Patients with no known increased risk who underwent total knee
arthroplasty received 325 mg of enteric-coated aspirin PO BD X 6
weeks
• Patients with known increased risk who underwent total hip
arthroplasty received 40 mg of enoxaparin sodium daily for ten days
and then 325 mg of aspirin PO OD X4 weeks
• Aspirin was determined to be a cost-effective choice in venous
thromboembolism prophylaxis when compared with low-molecular-
weight heparin

13. Infection
• Publications have focused on prevention but because of the complex nature
and variable diagnosis further research required
• Potentially correctable risk factors, notably obesity and anemia
• Perioperative Infection Prophylaxis:
• Chlorhexidine skin preparation agents have been advocated as superior to
iodine-based agents
• chlorhexidine wash cloths and intranasal povidone-iodine solution decreased
surgical site infection

15. Antiseptic Wound Irrigation to Prevent Surgical
Site Infection
• Use of dilute povidone iodine (1.3 to 1.5 g/L) or chlorhexidine
gluconate (0.05%) for wound irrigation .
• Povidone iodine, although effective in decreasing bacterial
concentrations, was also found to be cytotoxic .
• Long-term and short-term efficacy of this practice in hip
arthroplasty remains to be clearly determined .

16. Pain Prevention, Management, and Overall Patient
Experience Following Total Hip Replacement
• Perioperative pain management and overall patient expectations
and satisfaction are becoming increasingly important .
• Preoperative teaching classes have been viewed as being of
positive benefit .
• In Cochrane review most of the parameters studied showed only
modest increase in results after having taken preoperative classes .

17. Infiltration of Local Anesthetic
• Use of local infiltration injection for total hip replacement has
generated substantial interest and popularity
• Several studies compared Bupivacaine alone vs Local infiltration
mixture, including ketorolac, morphine, epinephrine, isomeric
bupivacaine and clonidine for intraarticular analgesia
• Consensus : local infiltration does improve pain control while
decreasing early opiate consumption

19. Surgical Advances in Total Hip Replacement
Posterior approach : increased association with dislocation
Anterior approach to the hip joint is currently gaining popularity:
• Superior intraoperative visualisation of the acetabulum
• Musculature stability
• Anterior approach has also been associated with an increased rate of
complications, including femoral perforations, trochanteric fractures,
and calcar fractures
• Insufficient evidence of clear superiority of either procedure.

20. Hip Replacement Components
• Acetabular component -
consists of two components
• Cup - usually made of titanium
• Liner - can be plastic, metal or
ceramic
• Femoral components
Head
Neck
stem

21. FEMORAL STEM DESIGN
• Femoral stems used with cements
• Cementless stem with porous surface
• Nonporous cementless stems
• Modular femoral stems

22. FEMORAL STEMS USED WITH CEMENTS

23. Effects of Fixation
Cemented Fixation :
• Randomized trial comparing four stem designs, Hutt et al. studied the
effect of a collar-and-surface finish on cemented femoral stems
• In presence of a collar, surface finish did not significantly affect
survivorship or function
• Between the collarless groups, a polished surface conferred an improved
survivorship
• Use of femoral stems that are tapered or wedge shaped may predispose
patients to a periprosthetic fracture

24. • High incidence of early
periprosthetic fracture in elderly
patients treated with a cemented,
collarless, polished, and tapered
stem
• Tapered stem acted as a wedge,
splitting the femur after a direct hip
contusion

25. CEMENTLESS STEMS WITH POROUS SURFACES

26. Cementless Fixation
• Several studies have evaluated the effect of age on cementless
fixation
• Cementless fixation was associated with an increased risk of
revision in elderly
• Stea et al. found that, in patients who were ≥75 , uncemented
fixation had a significantly higher risk of revision (p < 0.001) than
hybrid fixation

27. Acetabulum
• RCT comparing solid-backed components VS cluster
hole components used without screws
• Outcome measured : acetabular osteolysis
• Result : No differences between groups
• Conclusion:
cluster-hole cups instead of solid cups would give the surgeon the
option to use screws for stability as required

28. Demand Matching of Implants
• Matching implants with the physical needs of the patient is called
demand matching
• Cemented implants, presumably less expensive, were associated
with improved outcomes in patients older than sixty-five years
VS
• Increased risk of immediate perioperative complications with the
use of cemented implants, especially in the elderly population

29. Bearing surfaces
• Ideal bearing surface : friction coefficient as low as possible to
prevent generating wear particles
Three types:
• Metal
• Ceramic
• Polyethylene

31. Bearings
Ceramic on Polyethylene
• Sedrakyan et al. evaluated the influence of head size (>28 mm
compared with ≤28 mm
• use of ceramic implants with a smaller head size in cementless
hip arthroplasty was associated with a higher risk of revision

32. Metal on Polyethylene
• RCT RESULTS:
• No significant clinical differences were found between
Oxinium and cobalt chromium on standard and cross-linked
polyethylene
• Revision rate was 5.4% for the conventional polyethylene
bearing compared with 2.8% for the highly cross-linked
bearing

33. Metal on Metal
• ICOR meta-analysis study,
Implant survival of large-head-size (>36 mm), metal-on-metal,
cementless implants was compared with that of metal-on-highly
cross-linked polyethylene implants
Conclusion :
• large-head-size, metal-on-metal implants were associated with
increased risk of revision compared with metal-on-polyethylene
articulations

34. Prospective randomized study
• evaluated metal ion levels at a five-year follow-up using 28 and 36-
mm metal on-metal and 28-mm metal-on-polyethylene total hip
replacements
Results:
• Cobalt and chromium ion levels at five years were significantly
lower in the metal-on-polyethylene group
• Cobalt levels showed significant increases from two to five years in
the 36-mm metal on-metal group compared to 28mm

36. Modularity
• Modularity in hip arthroplasty has become common on both the femoral and
acetabular sides
• Introduction of dual-neck modularity : ability to adjust length, offset, and
version independent of stem size .
Disadvantage:
• fatigue fractures
• gross trunnion failure
• spontaneous modular head dissociation
• Modular neck stems did not improve hip scores and did not reduce the
likelihood of complications or dislocation

38. • serious complication of modularity is mechanically assisted crevice
corrosion.
• corrosion has been documented for every modular connection in hip
arthroplasty regardless of bearing type, including the acetabular liner
taper
A systematic review of head-neck taper corrosion identified risk factors
• larger head size
• small taper dimensions
• coating precipitation
• mixed alloy coupling
• head-neck modulus mismatch

39. CONCLUSION
• Total hip replacement (THR) is one of the most commonly performed
elective orthopaedic procedures
• Revision THR procedures are associated with increased perioperative
mortality and morbidity
• Mandatory for surgeons to maximize their understanding and education to
improve implant survivorship
• Optimise patient-related risk factors, utilizing effective surgical techniques,
and technologically advanced prosthesis

40. THANK YOU