David R. Cooper, M.D. www.thekneecenter.com Wilkes-Barre, Pa.
Knee Joint- Anatomy Is not a pure hinge Ligaments are balanced Mechanism of injury determines what structures get damaged
Medial meniscus tears 10x as often as lateral Gaps can exist normally behind the meniscus Can be read as torn when in fact normal
Consistent
Enables us to do soft tissue imaging Does not use radiation May not enable us to determine whether a finding is acute or chronic There are false positives and false negatives Watch out for degenerative tears
Meniscal Tears on the MRI Cannot age tear or absolutely tell whether it is mechanical or degenerative. Any prior meniscal surgery will always show up as an abnormality on a subsequent MRI Do not pick up a meniscal tear on an NCP solely based upon the MRI report Who read the MRI?
Single tear Flap displaces anteriorly No chondral injury ACL is normal Lateral meniscus is normal Can expect full recovery
Only the torn portion is removed Remainder of meniscus is normal Unlikely to retear
Inner segment displaced into joint blocking full extension Can be removed and/or repaired ACL intact Good prognosis
Segment is removed No blood supply; Thus will not heal Good maintenance of joint space after removal No chondromalacia (cartilage fragmentation)
Multiple small tears Subchondral bone is exposed Lateral side normal A poor result not unexpected
A trauma related meniscal tear occurs with a twist or squat under weight bearing Direct blow does not tear a meniscus Degenerative tears are not caused or aggravated by arthritis Arthroscopic surgery effects a full recovery in a motivated individual.
Direct blow to front of tibia does not tear ACL It actually loosens the ACL Posterior or Lateral stress can tear ACL ACL tear leads to a Knee full of blood
Blood vessels course along the ACL in the synovium. As the ligament tears, the blood vessels rupture. Large, tense effusion of blood. Does not occur from a frontal blow. Can be associated with other ligament injuries.
Linguini- like appearance Hemorrhage shows it is recent Non-repairable; It must be reconstructed using a graft that does not have the same properties or placement Do you really want a cadaver graft in your knee?
Twist or hyperextension Knee fills with blood- can be seen by ER doc and X-ray No prior history of knee injury Usually requires extensive surgery
Full recovery is unlikely Working at heights is not recommended Difficult to objectively define recovery Post traumatic arthritis can ensue in 25% even with a good surgical result Usual restrictions are light duty with no repetitive climbing, squatting, kneeling
Visible only on an MRI May be a precursor of traumatic arthritis High association with ACL tears Serial MRI s may show resolution if chronic pain ensues
Any condition that causes inflammation of a joint that may progress to destruction and loss of the articular cartilage.
It is a disease process of unknown etiology. Articular surface of joints are made of protein and water. For some reason(s) the articular surface breaks down exposing underlying bone. Articular cartilege has no nerve fibers. Bone has less protection----i.e. pain.
200mg/day for 30 months. 431 overweight women 45-64yrs. Women on doxycycline had 33% less cartilage deterioration than those on placebo. They also had less pain. Indiana University Study- Dr. Kenneth Brandt.
NO! That is a separate condition traumatic arthritis The surface of the knee is damaged, and the underlying bone is exposed
Articular surface dries up and flakes off Not related to trauma No nerve endings to cause pain.
Raw bone exposed Surrounding cartilage is normal No other damage seen May be seen on an MRI along with a bone bruise
Serial MRI s after trauma show no more deterioration Subsequent weightbearing x-rays show no more narrowing Joint space narrowing
Knee replacements never get done on someone who falls down at home I ve personally done over 600 TKR Gradually increasing pain with inability to walk level surfaces Only when litigation is involved do TKR s get involved with soft tissue trauma
I didn t hurt before, but now it is killing me. If pain is the sole indicator, then why can t other conditions aggravate arthritis. No scientific or statistical evidence to link trauma and progression of arthritis.
Frye, Daubert, Rule 702 Daubert- scientific studies Frye- preponderance of opinions Frye- may also include statistical studies or lack of them Worker s comp in Pa. does not need the above to render opinion.
Scientifically, Smoking increases rate of cartilage degradation 2007 Mayo Clinic study Male smokers had 2x loss of Art Cart compared to nonsmokers MRI used to measure loss of cartilage
Get past medical records and look for prior x-rays and statements indicating a knee replacement was considered prior to the work event Request follow-up MRI or WB x-ray to see if arthritis has worsened
No anatomic change in Knee = No Aggravation See if prior medical records indicate prior surgery from a different employer May actually be post traumatic arthritis from a prior surgery.
Viscosupplemntation- Synvisc, hyalgan, Supartz, Euflexxa, Orthovisc May increase thickness of articular cartilage
Can be work related if indicated for traumatic arthritis If indicated for osteoarthritis may not be work related. Can be used off label for synovitis following surgery Be wary of bills for this- you may be picking up non work related arthritis
Meniscal tears are usually benign, and occur with a minor twist ACL tears are obvious and have a definite clinical presentation Osteoarthritis is not related to trauma Get how your knee injury occurred. Can make or break your case.