1. Michael O. Williams, M.D., F.A.A.O.S.
Oxford® Partial Knee
Michael O. Williams, M.D., F.A.A.O.S.

2. Oxford Partial Knee Replacement
The Oxford partial knee replacement is indicated for treatment of anteromedial osteoarthritis of the knee. This arthritis involves primarily the medial compartment of the knee with joint space narrowing seen on X-rays. The lateral compartment and patella are usually not arthritic in this condition. The Oxford differs from other partial knees in that it has a mobile UHMWPE bearing which duplicates normal knee kinematics.

3. Arthritis Defined as inflammation of the joint
Number one cause of disability in
the United States1
More than 100 different types
Two primary types
Rheumatoid
Osteoarthritis

4. Rheumatoid Arthritis Inflammatory
Diagnosed at younger ages than osteoarthritis
Can affect multiple joints at one time
Excess synovial fluid
Cartilage destruction

5. Osteoarthritis Degenerative joint disease
Most common form of arthritis
Wear and tear condition
Develops over time
Overuse, injury or repetitive movement
Developmental disorders
Results in pain, stiffness

6. Symptoms of Osteoarthritis2
Pain
Stiffness
Grating or “catching” sensation during joint
movement
Bony growths at the margins of affected joints

7. X-Rays Helps determine severity of joint damage
Cannot see cartilage on an X-ray
Space on normal X-ray is healthy cartilage

8. Healthy X-ray
Space shows healthy cartilage

9. Osteoarthritis X-ray Joint space narrowing Abnormal bone formation
“spurs”
Joint deformity
Bowleg
Knock-knee
A manageable, treatable condition

10. When to Consider Joint Replacement
Conservative non-operative treatments fail to provide adequate pain relief
Diminished quality of life
Diminished joint function

11. Joint Replacement Also called “arthroplasty”
Implants to resurface damaged bone and cartilage
Metal alloy and durable plastic
Traditional vs. min. invasive with Oxford® Partial Knee

12. Traditional Total Knee Replacement
Resurfaces damaged cartilage on:
End of femur
Top of tibia
Back of patella
Incision between six and eight inches long

13. Primary Knee Components
Femoral Component
Polyethylene Bearing
Tibial Tray

14. Minimally Invasive Knee Replacement
Potential advantages to traditional knee replacement
Healthy muscles and tissues preserved
May be through a shorter incision
Less blood loss
Less tissue damage
Not all patients are candidates

15. Minimally Invasive vs. Traditional Incisions
Minimally Invasive Incision
Traditional Incision

16. Minimally Invasive Partial Knee Replacement
Replaces one compartment of the knee
Knee cartilage resurfaced
Metal alloy and polyethylene (plastic) components
Instrumentation for minimally invasive technique to help preserve healthy tissue

17. Oxford Partial Knee Components
Femoral Component
Polyethylene
Bearing
Tibial Tray

18. Oxford® Partial Knee Animation

19. Oxford® Partial Knee Implant
Only mobile-bearing partial knee in U.S.
Mobile plastic bearing moves with knee motions
Mobile bearing helps limit forces to help avoid loosening4,5
One clinical study yielded a 94%
success rate at 10 years and an
89% success rate at 20 years6
There is no specific expected survivorship for joint replacement

20. Examples of Potential Complications of Total Joint Replacement, Any of Which Can Lead to Revision Surgery
Infection
Blood clots
Implant breakage
Malalignment
Wear
Loosening
Dislocation
No implant will last forever

21. Complications Affecting Outcome & Longevity
Malalignment of implants
- Very dependent on surgical technique and surgeon’s skill level
- Can be prevented with Signature cutting blocks and guides

22. Signature ™ Personalized Patient Care

23. Signature ™ System
Patient-specific femoral and tibial positioning guides (not implanted) used for instrument placement to remove damaged bone and cartilage
Developed from MRI Scan
Allows for personalized instrumentation for implant positioning

24. Before Surgery Traditional Signature™ System
X-rays to plan implant size
Signature™ System
MRI Scan to plan surgery
Digital, interactive planning software
Plans implant size and placement before surgery

25. Pre-op MRI/CT Scan About 20 minutes for MRI scan Scan of hip,
knee and ankle
Head stays outside
of machine
MRI

26. The Surgical Procedure
Signature
Patient-specific Guides
Unique to every patient
Placed directly on bone/cartilage
Position pins for cut blocks
Cut blocks guide removal of damaged bone and cartilage

27. Surgical Instrumentation
Traditional
Signature™ System

28. Signature™ System Benefits
Does not invade the bone canal
Fewer surgical instruments than traditional partial knee replacement
Allows for personalized instrumentation for placement of the Oxford® Partial Knee implant
Reduces the incidence of malaligned components do to surgeon error
Implant alignment optimized for that patient

29. Value of Joint Replacement
Total joint replacement can save an individual as much as $68,000 (total knee replacement) to $180,000 (total hip replacement) in medical costs over the life of the average total joint recipient as compared to non‐surgical treatment.4,5

30. Success of Total Joint Replacement
Every year, over 1,000,000 people in the United States have joint replacement
Joint replacement treats debilitating pain and deformity from various forms of arthritis

31. Closing
A proper diagnosis from an orthopedic surgeon can help identify cause of joint pain
Many conservative treatments available
Arthritis can be treated
New surgical treatments also now available with joint replacement implants with improved function and longevity

32. References
Centers for Disease Control and Prevention
The Arthritis Foundation
Vanguard Complete Knee System Package Insert
Argenson, J. et al. Polyethylene Wear in Meniscal Knee Replacement. A One to Nine-year Retrieval Analysis of the Oxford Knee. Journal of Bone and Joint Surgery [Br]. 74 B:228–32, 1992.
Psychoyios, V. et al. Wear of Congruent Meniscal Bearings in Unicompartmental Knee Arthroplasty—A Retrieval Study of 16 Specimens. Journal of Bone and Joint Surgery [Br]. 80-B:976–82,1998.
Price, A. and Svard, U. A Second Decade Lifetable Survival Analysis of the Oxford Unicompartmental Knee Arthroplasty. Clinical Orthopaedics and Related Research. Published Online 13 August 2010
AAOS.
Chang RW, Pellissier, JM, Hazen GB, “A Cost‐effective Analysis of Total Hip Arthroplasty for Osteoarthritis of the Hip,” Journal of the American Medical Association (JAMA), Vol. 275, No.11, 1996, pp. 858‐865. (Figures apply to average 60 year old patient and adjusted for inflation.)

33. Questions

34. Thank You