Knee Conditions and Treatments
Patellar (kneecap) dislocations occur with significant regularity,
especially in younger athletes. Most of the dislocations occur laterally
(outside). When these occur, they are associated with significant pain
and swelling. Following a patellar dislocation, the first step must be
to relocate the patella into the trochlear groove. This often happens
spontaneously as the individual extends the knee either while still on
the field of play or in an emergency room or training room as the knee
is extended for examination. Occasionally relocation of the patella
occurs spontaneously before examination and its occurrence must be
inferred by finding related problems.
Associated problems normally occur with patellar dislocations, the most
obvious of which is tearing of the ligaments that stabilize the kneecap
itself. As is the case with all other joints, ligamentous disruption or
tearing occurs to allow the joint to dislocate. In the case of patellar
dislocation, the ligaments on the inside of the knee are the most
commonly injured as the kneecap slides laterally. While tearing of these
ligaments is unfortunate, they do have the potential to heal. Of much
more concern, are the small fragments of cartilage and bone that often
are knocked off of the kneecap or the lateral femoral condyle during the
relocation of the kneecap. These fragments become loose bodies and
usually require removal during an arthroscopic procedure. Patellar
dislocations can cause significant quadriceps muscle injuries, which can
be made worse due to the effusion within the knee or to early onset of
exercises and premature return to play.
A condition referred to as patellar subluxation also exists. The
problem exists on a continuum between patellofemoral malalignment and
patellar dislocation. It can be sequelae of a traumatic dislocation or
in situations where patellar hyperlaxity exists. A subluxation is a
partial dislocation in which the patella attempts to dislocate but does
not do so completely. Situations such as these are very disconcerting
and often give the patients a sense of giving way or buckling. At a
minimum, these situations should be treated with aggressive therapeutic
intervention as the constant subluxation events not only will interfere
with competition, but will also potentially cause repeated wear and
discomfort within the patellofemoral joint.
Patellar dislocations can occur either in contact or non-contact
situations. An athlete can dislocate his/her patella when the foot is
planted and a rapid change of direction or twisting occurs. Usually a
pre-existence ligamentous laxity is required to allow a dislocation to
occur in this manner. Direct blows to a knee can cause dislocations as
well. The force of these is obviously much greater and usually causes
more severe damage especially to restraining ligaments.
- Rapid, acute swelling.
- Extreme pain initially until relocation occurs.
- Continued pain along medial (inside) ligaments.
- Discoloration medially at site of ligament injury.
- Sense of instability and apprehension that problem will recur.
Normal care of patellar dislocations, when a loose fragment has not been
created is the immobilization of the knee for a short period of time
(seven to 10 days). During this time, the swelling is reduced and the
acute discomfort of the dislocation decreases. Slow mobilization of the
knee and of the patellofemoral joint is then begun, and usually full
recovery can be expected within a three to six week period. This period
of time is significantly lengthened when the patellar dislocation is
Unfortunately, once a patellar dislocation occurs, especially when it
occurs in a situation where hyperlaxity of the ligaments exists, which
is commonly the case, recurrent dislocations can be expected. These are
significantly problematic for athletes as they often come in the midst
of the season. Conservative management of these problems in season with
appropriate rest, appropriate hip and thigh muscle strengthening, and
perhaps the use of a patellar buttress brace is appropriate.
Alternative Treatment Options
Some situations of patellar dislocation can and/or should be treated
surgically. One situation is when recurrent dislocations occur. In these
situations, to limit the amount of lost time in competition and to
reduce the chances for cartilage lesions on the undersurface of the
patella, which often are non-reparable, patellar stabilization
procedures are appropriate. These procedures can be either soft tissue
or bone procedures, or a combination thereof. First-time traumatic
patellar dislocations can also be treated with procedures such as this,
and in chosen situations doing so may be appropriate.
It has been found in retrospective studies that the incidence of
recurrent dislocation after the first dislocation occurs can be as high
as 40 percent. Surgically treating those dislocations by lessening
lateral tension and tightening medial restraint could reduce this
recurrence rate to below 10 percent.
Surgical procedures on the patella are usually done in the
out-patient setting. Procedures limited to altering soft-tissue tension
begin rehabilitation within a week and return to activity can be
expected as early as six weeks. Procedures that require bone work (osteotomies)
require a period of relative immobilization and need 10 to 12 weeks
before a return to athletic activity is permitted.
Our Specialists and Staff
Thomas M. DeBerardino, M.D.
Laurencin, M.D., Ph.D.
- Augustus D. Mazzocca, M.S., M.D.
- Kevin P.
- Cindy Baczewski, P.A.-C., M.H.S.
- Kim Stanowski, P.A.-C.
Frequently Asked Questions
For more information or to make an appointment, call 860-679-6600 or 800-535-6232.
8 a.m. to 4:30 p.m.
Monday through Friday
New England Musculoskeletal Institute
Medical Arts & Research Building
UConn Health Center
263 Farmington Avenue
Farmington, CT 06030-5352
Southington Medical Office
1115 West Street
Southington, CT 06489