Not to be confused with Runner's knee which often affects runners; or
Sinding-Larsen and Johansson syndrome and Osgood-Schlatter disease which
primarily affect young athletes. Patellar tendinitis, is a relatively
common cause of pain in the inferior patellar region in athletes. It is
common with frequent jumping and studies have shown it may be associated with
stiff ankle movement and ankle sprains. Presentation
Jumper's knee commonly occurs in athletes who are involved in jumping
sports such as basketball and volleyball. Patients report anterior
knee pain, often with an aching quality. The symptom onset is insidious. Rarely
is a discrete injury described. Usually, involvement is infrapatellar at or near
the infrapatellar pole, but it may also be suprapatellar.
Depending on the duration of symptoms, jumper's knee can be classified into 1
of 4 stages, as follows: Stage 1 – Pain only after activity,
without functional impairment Stage 2 – Pain during and after
activity, although the patient is still able to perform satisfactorily in his or
her sport Stage 3 – Prolonged pain during and
after activity, with increasing difficulty in performing at a
satisfactory level Stage 4 – Complete tendon tear requiring
surgical repair It begins as inflammation in the
patellar tendon where it attaches to the patella and may progress by tearing or
degenerating the tendon. Patients present with an ache over the patella
tendon. Most patients are between 10 and 16 years old. Magnetic resonance imaging
can reveal edema in the proximal aspect of the patellar tendon.
Causes It is an overuse injury from repetitive
overloading of the extensor mechanism of the knee. The microtears exceed the
body's healing mechanism unless the activity is stopped.
Among the risk factors for patellar tendonitis are low ankle dorsiflexion,
weak gluteal muscles, and muscle tightness, particularly in the calves,
quadriceps muscle, and hamstrings. The injury occurs to athletes in many
sports. Treatment
Early stages may be treated conservatively using the R.I.C.E
methods. Rest
Ice Compression
Elevation Exercises involving eccentric muscle
contractions of the quadriceps on a decline board are strongly supported by
extant literature. A physical therapist may also recommend specific exercises
and stretches to strengthen the muscles and tendons.
Should this fail, autologous blood injection, or platelet-rich plasma
injection may be performed and is typically successful though not as
successful as high volume saline injection. Uncommonly it may require
surgery to remove myxoid degeneration in the tendon. This is reserved for
patients with debilitating pain for 6–12 months despite conservative measures.
Novel treatment modalities targeting the abnormal blood vessel growth which
occurs in the condition are currently being investigated.
See also Patellar tendon rupture
Tendinitis Tendinosis
Repetitive strain injury References
Further reading Kaplan, Helms, Dussault, Anderson, and
Major Musculoskeletal MRI 2001 . Khan KM, Bonar F, Desmond PM, et al..
"Patellar tendinosis: findings at histopathologic examination, US, and MR
imaging. Victorian Institute of Sport Tendon Study Group". Radiology 200:
821–7. doi:10.1148/radiology.200.3.8756939.
PMID 8756939. Kettunen JA, Kvist M, Alanen E, Kujala
UM. "Long-term prognosis for jumper's knee in male athletes. A prospective
follow-up study". Am J Sports Med 30: 689–92. PMID 12239003.
Tom Crisp, Faisal Khan, Nat Padhiar; et al.. "High volume ultrasound guided
injections at the interface between the patellar tendon and Hoffa's body are
effective in chronic patellar tendinopathy: A pilot study". Disability
and rehabilitation. 30: 1625–34. doi:10.1080/09638280701830936. PMID
18608403. External links
Jumpers Knee & Acrobatics Patellar Tendinitis, Musculoskeletal
Consumer Review Ultrasound images demonstrating patella
tendinosis and an autologous blood injection