Patellar tendinitis (or jumper’s knee) is an overuse conditions that is frequently associated with eccentric overloading during deceleration activities (repeated jumping and landing, downhill running).

It’s most common in athletes who participate in sports such as basketball and volleyball.

The association of patellar tendinitis with jumping was first described by Maurizio, but the term jumper’s knee originated from Blazina et al. Some authors feel that the term patellar tendinitis is a misnomer because the patellar “tendon” which connects two bones, is in fact a ligament.

See Also: Patellar Instability
Patellar Tendinitis - jumper's knee
Patellar Tendinitis – Jumper’s knee

Patellar Tendinitis Classification

Blazina classification system for jumper’s knee:

  • Phase I: pain after activity only.
  • Phase II: pain during and after activity.
  • Phase III: persistent pain with or without activities, deterioration of performance.

Clinical Findings

The diagnosis of tendinitis is based on a detailed history and careful palpation of the tendon in both flexion and extension.

Pain on palpation near the patellar insertion that is worsen in extension more than in flexion (Basset’s sign).

A swelling may be noticed over the patellar tendon.

Basset’s sign: tenderness to palpation at distal pole of patella in full extension, with no tenderness to palpation at distal pole of patella in full flexion.

Radiographic Imaging

  • Recommended views include: AP and lateral view.
  • Findings may include inferior traction spur in chronic cases.

US findings may reveal a thickening of the patellar tendon.

MRI Findings may include: tendon thickening, increased signal intensity on both T1 and T2 images and loss of the posterior border of fat pad in chronic cases.

Patellar tendinitis Treatment

Non-operative treatment:

Non-operative treatment of Patellar tendinitis includes:

  1. Nonsteroidal anti inflammatory drugs (NSAIDs),
  2. Ice,
  3. Rest,
  4. physical therapy (strengthening including eccentric exercise and ultrasonography),
  5. orthoses (patella tendon strap or Chopat’s strap).
patella tendon strap
Patella Tendon Strap

Operative Treatment:

Surgical intervention is usually required only if significant tendonosis develops.

It’s involving excision of necrotic tendon fibers, and it is rarely indicated.

Patellar Tendinitis Physical Therapy

Several protocols have been advocated for the conservative intervention of patellar tendinitis.

Stanish et al. proposed the following strengthening program of eccentric exercise for chronic patellar tendinitis:

A 5-minute warm-up period consisting of a series of three to five static stretches held for 15–30 seconds each is performed. Next, the patient, from a standing position, flexes the knees, abruptly drops to a squatting position, and then recoils to the standing position. The velocity of the drop is increased until the patient is able to perform it as quickly as possible without pain. At this point, sandbags are added to the patient’s shoulders to increase the load on the tendon. Apart from some minor discomfort during the exercises and some post exercise muscle soreness, the procedures should be performed without pain.

Reid proposes a protocol based on the severity of the lesion:

  • Grade I lesions, which are characterized by no undue functional impairment and pain only after the activity, are addressed with adequate warm-up before training and ice massage after training.
  • With grade II to III strains, activity modification, localized heating of the area, a detailed flexibility assessment, and an evaluation of athletic techniques are recommended. In addition, a concentric–eccentric program for the anterior tibialis muscle group is prescribed, which progresses into a purely eccentric program as the pain decreases.

The patient is positioned in supine with the foot in full plantar flexion. The clinician applies overpressure on the posterior aspect of the foot, placing the foot into further plantar flexion and stretching the anterior tibialis. The patient is asked to perform a concentric contraction into full dorsiflexion, which is resisted by the clinician.

An eccentric contraction is then performed by the patient by returning the foot into its plantar flexed position as the clinician resists the motion from full dorsiflexion to full plantar flexion. This maneuver is repeated to the point of fatigue of the anterior tibialis.

As soon as possible, the eccentric loading program is added. It is not clear why a program initially directed at the anterior tibialis muscle group should be therapeutic for the infrapatellar tendon and ligament, but it is theorized that the program may stretch the infrapatellar ligament, change the quadriceps to-foreleg strength ratio or alter the biomechanics of take-off and landing.

References

  • Blazina ME, Kerlan RK, Jobe FW, Carter VS, Carlson GJ. Jumper’s knee. Orthop Clin North Am. 1973 Jul;4(3):665-78. PMID: 4783891.
  • Maurizio E: La tendinite rotulea del giocatore di pallavolo. Arch Soc Tosco Umbra Chir 24:443–445, 1963.
  • Anderson JE: Grant’s Atlas of Anatomy, 7th ed. Baltimore, MD:Williams & Wilkins, 1980.
  • Hollinshead WH, Rosse C: Textbook of Anatomy. Philadelphia, PA: Harper & Row, 1985.
  • FredbergU,BolvigL:Jumper’s knee.ScandJMed Sci Sports9:66–73, 1999.
  • Stanish WD, Rubinovich RM, Curwin S: Eccentric exercise in chronic tendinitis. Clin Orthop Relat Res 208:65–68, 1986.
  • Popp JE, Yu SS, Kaeding CC: Recalcitrant patellar tendinitis, magnetic resonance imaging, histologic evaluation, and surgical treatment. Am J Sports Med 25:218–222, 1997.
  • Dutton’s Orthopaedic Examination, Evaluation, And Intervention 3rd Edition.
  • Millers Review of Orthopaedics -7th Edition Book.