A Minimally Invasive
Approach to Knee Arthritis
With assistance from James E. Dowd, MD (Virginia Beach, VA)
Sponsored by:
Arthritis affects 70 million Americans
• 2nd only to heart disease
in causing disability
• 1 million new patients
diagnosed each year
• Affects 50 percent of
people 65 years of age
and older
• Population of older
adults with arthritis will
nearly double by 2030
The Knee and Osteoarthritis
• Most common joint affected by
osteoarthritis
• Large weight-bearing joint
• Complex motion pattern
• Common site of injury
Osteoarthritis is the most common
form of arthritis
• Rheumatoid arthritis
• Post-traumatic
arthritis
• Inflammatory arthritis
• Septic arthritis
All result in loss of
joint cartilage
Presenting Symptoms of Arthritis
• Stiffness
• Swelling
• Long limb deformity
– (“knock-knee”/ “bow-leg”)
• Crepitus
• Activity limiting PAIN!
Initial Conservative Treatments
• Tylenol®
• Physical therapy
• NSAIDs
• Activity modification
• Nutritional
supplements
• Weight loss
Therapeutic Injections
• Corticosteroid
– Inter-articular antiinflammatory agent
• Viscoelastic Series
– Augment normal joint
lubrication
– Hyaluronic Acid (HA)
©MMG 2001
The Most Common Complications
• Cortisone Injections
– Allergic reaction, joint swelling and pain several hours after
injection and infection
• Hyaluronic Acid (HA) Injections
– Temporary pain, swelling, and/or fluid accumulation in the
injected knee
These procedures are not for everyone. Results vary in patients.
The Orthopaedic Specialist
• When conservative treatments
no longer resolve activity
limiting pain caused by
osteoarthritis then . . .
• Surgical and reconstructive
treatments may be appropriate
Surgical Options for Knee Arthritis
• Arthroscopy
– debridement,
meniscectomy,
chondroplasty
• Osteotomy
– bone re-alignment
• Arthroplasty
– joint replacement
Arthroscopic Debridement
“clean out” or “scrape bone”
• Somewhat unpredictable
results
• 50 to 66 percent get relief for
some period of time
• Best for patients with
mechanical symptoms
(catching, locking and giving
out)
Knee Osteotomy
Re-align weight-bearing axis through “good” cartilage
• Most popular before success of
contemporary knee replacement
• Useful for patients too young,
heavy or active for knee implants
• Early results acceptable,
questionable durability
The Most Common Complications
• Arthroscopy
– Bleeding, infection and blood clots
• Osteotomy
– Insufficient pain relief, nonunion/malunion, intra-articular
fracture, DVT, infection and neurovascular injury
These procedures are not for everyone. Results vary in patients.
End-Stage Osteoarthritis 
Knee Replacement
“Gold Standard of Care”
• Uni-compartmental Knee Replacement
– “Uni,” “partial replacement” or UKR
• Tri-compartmental Knee Replacement
– “total replacement” or TKR
The Knee: 3 Compartments
PatellaFemoral
Lateral
Medial
Osteoarthritis in 1 of 3 Compartments:
Treatment = UKR
Uni-compartmental Knee
Replacement (UKR)
• 20+ year clinical history
• Less commonly performed
– Growing interest utilizing
minimally invasive techniques
Osteoarthritis in 2 of 3 Compartments:
Treatment = TKR
Total Knee Replacement (TKR)
• 30+ year clinical history
• >95 percent of all knee
replacements performed
Uni-compartmental Knee Replacement
(Early Results)
• Aglietti & Insall – 30 percent revised at 5 to 7 year
follow-up
(Aglietti, Paulo, MD and John Insall, MD. “A Five to Seven Year Follow-up of Unicondylar Arthroplasty.” Journal of
Bone and Joint Surgery Dec. 1980: 1329-1337.)
• Marmor – 65 percent survivorship at 11 year
follow-up
(Marmor, Leonard, MD. “Unicompartmental Knee Arthroplasty Ten- to 13-Year Follow-up Study.” CORR Jan. 1988:
14-20.)
• Scott, et al. – 85 percent survivorship at 10 year
follow-up
(Scott, R.D., MD, et al. “Unicompartmental Knee Arthroplasty Eight- to 12- Year Follow-up Evaluation With
Survivorship Analysis.” CORR Oct. 1991: 96-100.)
Uni-compartmental Knee Replacement
(Early Challenges)
• Techniques
• Implants
• Instruments
Trusted Innovation
P.F.C. Sigma Heritage
1982
Fixed-bearing
LCS Heritage
1983
Mobile-bearing
Uni-compartmental Knee Replacement
long-term results (fixed-bearing)
10 Year Survival Rates
120%
100%
80%
60%
85%
91%
96%
90%
98%
70%
40%
20%
0%
Marm or, MD
1988
(n=228)
Scott, MD
1991
(n=100)
Heck, MD
1993
(n=294)
Ansari, MD
1997
(n=461)
Squire, MD
1999
(n=140)
Berger, MD
1999
(n=62)
Uni-compartmental Knee Replacement
long-term results (mobile-bearing)
10 Year Survival Rates
100%
90%
98%
95%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Murray, MD (1998), 144 UKAs
Svaard, MD (1999), 124 UKAs
Potential Patient Benefits with a
UKR Procedure
• Higher patient satisfaction
• Less blood loss
• Quicker recovery
• Less chance of infection
• Better range of motion
• Cost savings
Uni-compartmental Knee Replacement
“Show Me the Data”
• UKR versus TKR – 23 patients with both
– Average ROM UKR=123 degrees, TKR=110 degrees
– 44 percent preferred UKR side, 12 percent preferred
TKR
(Laurencin, C.T., MD, et al. “Unicompartmental Versus Total Knee Arthroplasty in the Same Patient.” CORR Dec. 1991: 151-156.)
• 81 UKRs versus 120 TKRs
– Blood Tx 1 percent with UKRs versus 67 percent
with TKR
(Rougraff, MD, et al. “A Comparison of Tricompartmental and Unicompartmental Arthroplasty for the Treatment of Gonarthrosis.”
CORR Dec. 1991: 157-164.)
Uni-compartmental Knee Replacement
“Show Me the Data”
• 50 UKRs versus 52 TKRs
– UKR = shorter hospitalization
– UKR = better knee flexion, 69 percent >120
degrees versus 17 percent TKRs
(Newman, MD, et al. “Unicompartmental or Total Knee Replacement? Five-Year Results of a Prospective, Randomised Trial of 102
Osteoarthritic Knees With Unicompartmental Arthritis.” Journal of Bone and Joint Surgery Br. Sept. 1998: 862-865. )
• Swedish Knee Registry
– Risk of infection 0.8 percent for UKR versus 2
percent for TKR
(Knutson, MD, et al. “Revision of Unicompartmental Knee Arthroplasty: Outcome in 1,135 Cases From the Swedish Knee Arthroplasty
Study.” Acta Orthop Scand 1998: 469-474.)
The Most Common Complications
• Knee Arthroplasty
Loosening, deformation or wear of one or more of the
components, osteolysis, infection, DVT and fracture of the
components or bone.
This procedure is not for everyone. As with any surgery, there are risks.
Recovery takes time and hard work. The life of a joint replacement depends
on weight, activity level, age and other factors. Each patient responds
differently.
UKR Today
Minimally Invasive Technique!
• 6 to 8 in. incision reduced
to 3 to 4 in.
• Minimal muscle trauma
• Extensor mechanism left
intact
UKR Today
Minimally Invasive Technique!
• Conservative bone
resections
• Minimal blood loss
• Shorter hospital stays
UKR Today
Minimally Invasive Technique!
Postoperative Recovery
• 24 to 48 hour hospitalization
(outpatient?)
• Weight-bearing as tolerated
• Improved range of motion
• Quicker return to activity
3 weeks postoperative
A Modern Implant System Designed for
Minimally Invasive Surgery
Instruments
GVF-UHMWPE
Implants
Minimally Invasive UKR
Who is a (traditional*) candidate?
• Elderly patient
• Isolated (uni-compartmental)
osteoarthritis
• <250 lbs
• Good ROM, minimal deformity
• Relatively sedentary activity level
*Deshmukh, R.V., MD and R.D. Scott, MD, “Unicompartmental Knee Arthroplasty:
Long Term Results”, CORR - No. 392 (pgs 272-278), 2001.
Minimally Invasive UKR
Who is a (relative*) candidate?
• Younger patients (<65 yrs)
• >250 lbs
• Higher activity expectations
(relative)
• Patella-femoral compartment
arthritis
*Experience of surgeons currently conducting UKR.
Minimally Invasive UKR
Who is a (good*) candidate?
• Younger patients with end-stage uni-compartmental
arthritis as a good conservative option that
minimizes bone removal and preserves additional
options for future surgery (UKR  TKR)
• Elderly patients with end-stage uni-compartmental
arthritis that would benefit from less surgery, less
down time and less rigorous recovery
*Experience of surgeons currently conducting UKR.
Thank you
Questions?
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