Introduction

Patellar tendinopathy is common in jumping sports such as basketball, volleyball etc. in recognition of its association with jumping, patellar tendinopathy was first described and is commonly referred as to as “Jumper’s Knee” This term is misleading, however, as the condition is found in a wide variety of sports people, including those who do not participate in sports involving jumping eg. Tennis and aerobics athletes are also at risk (1)

Patellar tendinopathy (jumper’s knee) is a clinical diagnosis of pain and dysfunction in the patellar tendon. It most commonly affects jumping athletes from adolescence through to the fourth decade of life. This condition affects health and quality of life by limiting sports and activity participation for recreational athletes and can be career-ending for professional athletes. Once symptoms are aggravated, activities of daily living are affected, including stairs, squats, stand to sit, and prolonged sitting. (2)

Clinical presentation (1)

• Patellar tendinopathy presents initially as well-localised anterior knee pain related to activity levels.
• Pain is usually insidious and gradual in onset, and may be precipitated by an increase in the frequency or intensity of repetitive ballistic movements of the knee.
• Initially pain may present as a dull ache at the beginning of or after strenuous activity. This initial symptom may be ignored as it warms up with further activity. With continued use; however, pain can progress to be present during activity and can ultimately interfere significantly with performance.
• In some cases there is a constant ache at rest and night pain that disturbs sleep.
• Other common complaints are pain when seated for long periods, and when ascending and descending stairs

Clinical Examination

Palpation (1)

• The most consistent finding is patellar tendon tenderness this is typically located at the inferior pole of the patella.
• It is influenced by knee position .With the knee flexed to 90 the tendon is placed under tension, and tenderness significantly decreases and may disappear altogether. Thus, the patellar tendon should be palpated in relaxed full-knee extension.

Observation

• Patients with chronic symptoms may exhibit wasting of the quadriceps, with the vastus medialis obliquus portion most commonly affected. Overall thigh circumference may be reduced and calf atrophy may also be present.

Functional Strength

• Functional strength testing of the quadriceps may be performed by asking the patient to perform 15 one-legged step-downs in which the non-weight–bearing foot is not allowed to touch the ground between cycles
• The work capacity of the calf can be assessed by performing single-legged heel raises. Both straight knees and bent knees, A jumping athlete should be able to perform a minimum of 40 raises (1)
• During both activities the onset of fatigue and the quality of movement should be monitored, and both activities should be performed bilaterally.

Key Functional Test

A key test is the single-leg decline squat. While standing on the affected leg on a 25 deg decline board, the patient is asked to maintain an upright trunk and squat up to 90 deg if possible.

The test is also done standing on the unaffected leg. For each leg, the maximum angle of knee flexion achieved is recorded, at which point pain is recorded on a visual analogue scale.

Diagnostically the pain should remain isolated to the tendon/ bone junction and not spread during this test.

Single Leg Decline Squat is an excellent self-assessment to isolate and monitor the tendon’s response to load on a daily basis. (2)

• Other Objective clinical test including single limb balance with eyes closed, depth of single limb squat, calf strength, repetitive single limb squats, modified gluteus maximus manual muscle test, gluteus medius manual muscle test, forward plank, side plank, knee to wall ankle dorsiflexion test, hamstrings flexibility test, Thomas test, hip internal rotation, and hip external rotation & Bio-mechanical assessment including Lower Extremity contact angle, knee joint angular stiffness etc. Are also essential to prevent and diagnose the conditions like Patellar Tendinopathy. (3)

Differential Diagnosis

The history and examination are crucial to distinguish patellar tendinopathy from other diagnoses including: patellofemoral pain; pathology of the plica or fat pad; patellar subluxation or a patellar tracking problem; and Osgood-Schlatter disease (2)

Imaging

It is commonly clinically diagnosed in conjunction with imaging (ultrasound or magnetic resonance, often to exclude differential diagnoses such as patellofemoral pain), where structural disruptions on the scans represent areas of tendon pathology. Importantly, there is a disconnection between pathology on imaging and pain;

It is common to have abnormal tendons on imaging in people with pain-free function. (2)

Risk and Associated Factors for Patellar Tendinopathy (2)

• Gender :- Men > Women
• Waist Circumference :- increased circumference higher the risk (It has been reported that men with a waist circumference greater than 83 cm are more likely to have abnormal changes on imaging
• Hamstring Length :- Less extensible hamstrings – increase risk of patellar tendinopathy
• Quadriceps length :- Stiffer quadriceps increase risk of patellar tendinopathy
• Dorsiflexion (ankle mobility) :- Reduced dorsiflexion associated with increased pathology
• Landing Strategies :- Less knee bend at landing (stiff knee landing), altered hip strategies associated with pathology
• Fat Pad Size :- Increased fat pad size associated with patellar tendinopathy
• Loading :- Excess loading associated with patellar tendinopathy

Treatment

Conservative v/s Surgical

No advantage has been demonstrated between surgical treatment and eccentric strength training. Therefore, eccentric training should be tried for 12 weeks before open tenotomy is considered for the Treatment of PT. (4)

I will write about Physiotherapy management & Treatment of Patellar Tendinopathy in my next blog

Kunal Bhatt
Physiotherapist

Featured in the Top 50 Physical Therapy Blog

Resources

1. Brukner, Peter and Warden, Stuart J. Clinics in sports medicine. www.peterbrukner.com. [Online] 2003. http://www.peterbrukner.com/wp-content/uploads/2012/07/63.-Warden-Brukner-Clin-in-Sports-Med-2003.pdf.
2. Physiotherapy management of patellar tendinopathy (jumper’s knee). Rudavsky, Aliza and Cook, Jill. 2014, Journal of Physiotherapy, pp. 122-129.
3. Physical therapists’ role in prevention and management of patellar tendinopathy injuries in youth, collegiate, and middle-aged indoor volleyball athletes. Kulig, Kornelia, et al., et al. 2015, Brazilian Journal of Physical Therapy, pp. 410-420.
4. The Treatment of Patellar Tendinopathy. Rodriguez-Merchan, E. C. 2013, Journal of Orthopaedics & Traumatology, pp. 77-81.