Patellar/Quadriceps Tendinitis

By admin On Oct 2, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Stephen Huang

Thomas Kern

Basics

Description

Overuse syndrome of the patellar tendon/quadriceps complex
Anterior knee pain worsened by activity such as jumping or running
Also termed “jumper's knee”

Epidemiology

Prevalence

Commonly seen in athletes who participate in sports with excessive jumping or running (volleyball, basketball, soccer, track and field)
Prevalence is estimated to be 40–50% among high-level volleyball players, and 35–40% among elite basketball players (1,2)
Affects males and females equally

Risk Factors

Participation in a sport with excessive “jumping” (volleyball, basketball)
Risk increases with training volume and intensity (3).
Poor flexibility of quadriceps and hamstrings

Etiology

Histopathology shows (4):
- Collagen degeneration and disorganization
- Increase in mucoid ground substance
- Fibroblast proliferation
- Neovascularization
- Absence of inflammatory cells
More accurately termed tendinosis or tendinopathy

Diagnosis

History

Anterior knee pain exacerbated by activity or by prolonged knee flexion
Participation in a sport with excessive jumping
A progressive condition of anterior knee pain (Blazina classification) (5):
- Phase 1: Pain after activity
- Phase 2: Pain during and after activity not affecting performance
- Phase 3: Pain during and after activity impeding performance

Physical Exam

Localized tenderness at the inferior pole of the patella and patellar tendon
Pain reproduced with extension of the knee vs resistance, or with maximal stretching of the quadriceps
Poor flexibility of the quadriceps and hamstrings

Diagnostic Tests & Interpretation

Imaging

Patellar tendinopathy remains a clinical diagnosis, and routine imaging is neither required nor recommended.
Plain film radiographs may show occasional intratendinous calcification.
MRI may reveal increased signal within the patellar tendon at the junction with the patella (4).
US may reveal focal hypoechoic areas in the patellar tendon or neovascularization on color Doppler flow (4).
The study of choice and relevance of abnormalities remains controversial.

Differential Diagnosis

Patellofemoral pain syndrome
Hoffa's disease (fat pad impingement)
Osgood-Schlatter disease
Sinding-Larsen-Johansson syndrome
Chondromalacia
Patellar subluxation/dislocation
Patellar tendon rupture

P.445

Treatment

Medication

Conservative measures typically include relative rest (reduction in amount or intensity of training to achieve pain-free state), ice, and NSAIDs
NSAIDs are commonly used as analgesics and may be beneficial for acute symptoms. However, there is a lack of evidence showing benefits in cases of chronic patellar tendinopathy.
Consider physical therapy for chronic symptoms.
Surgery is reserved for refractory cases.

Additional Treatment

General Measures

Stretching exercises of the quadriceps and hamstrings to improve flexibility
Eccentric strengthening exercises of the quadriceps
Correction of biomechanical abnormalities or training errors
The early results are promising for several other types of treatments, which theoretically re-create the inflammatory response or restart the failed healing process:
- Deep friction massage
- Platelet-rich plasma injections
- Prolotherapy

Surgery/Other Procedures

Patellar tenotomy may be considered for patients who fail conservative measures for 6 mos.
No randomized trials have been able to show the efficacy of one surgical technique over others.

Ongoing Care

Steroid injections into a tendon should be avoided due to the risk of tendon rupture.

References

1. Bahr R, Fossan B, Løken S, et al. Surgical treatment compared with eccentric training for patellar tendinopathy (jumper's knee). A randomized, controlled trial. J Bone Joint Surg Am. 2006;88:1689–1698.

2. Lian OB, Engebretsen L, Bahr R. Prevalence of jumper's knee among elite athletes from different sports: a cross-sectional study. Am J Sports Med. 2005;33:561–567.

3. Peers KH, Lysens RJ. Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations. Sports Med. 2005;35:71–87.

4. Khan KM, Bonar F, Desmond PM, et al. Patellar tendinosis (jumper's knee): findings at histopathologic examination, US, and MR imaging. Victorian Institute of Sport Tendon Study Group. Radiology. 1996;200:821–827.

5. Blazina ME, Kerlan RK, Jobe FW, et al. Jumper's knee. Orthop Clin North Am. 1973;4:665–678.

Additional Reading

Rees J, Maffulli N, Cook J. Management of Tendinopathy. Am J Sports Med. 2009.

Codes

ICD9

726.64 Patellar tendinitis