Quadriceps Tendonitis

Other Names

• Quad Tendinopathy
• Quadriceps Tendinosis
• Quadriceps Tendinopathy
• Jumper's knee
• Quadriceps tendinitis
• Quadriceps tendon overuse injury
• Quadriceps tendon strain
• Quadriceps tendon inflammation
• Suprapatellar tendinopathy
• Extensor mechanism tendinopathy (quadriceps component)
• Anterior knee extensor tendinopathy

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Quadriceps Tendonitis Case

• This page refers to acute/chronic tendinopathies of the Quadriceps tendon
• Note: Quadriceps Rupture, Quadriceps Strain is discussed separately

History

• One of the earliest published case reports of acute quadriceps tendonitis with calcification is by Trujeque and colleagues (1977)

Epidemiology

• Overall prevalence estimated to be seen in about 14.2% of athletes
• Zwerver et al cross sectional survey
  • Overall prevalence 8.5%
  • Highest prevalence volleyball (14.4%), handball (13.3%), basketball (11.8%), track and field (6.9%), field hockey (5.1%), korfball (4.8%), and soccer (2.5%)
  • Males (10.2%) more common than females (6.4%)
• In professional beach volley ball players: prevalance is 21-34%

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Pathophysiology

Typical location of quad tendonitis pain

Basic illustration of the extensor mechanism of the knee

Typical pain location of quadriceps tendonitis

General

• Clinical diagnosis characterized by pain in the quadriceps tendon and impaired performance, sometimes with tendon swelling
• Pain is most commonly at the proximal pole of the patella, typically worse with activities that activate the quadriceps
• Imaging can show increased tendon thickness and altered signal intensity but is not routinely required
• Treatment is non-surgical and includes activity modification, physical therapy and medications
• See also: Tendinopathies (Main)

Acute Quadriceps Tendonitis

• Represents the acute, early response to tendon overload
  • Characterized by microruptures of tendon fibers and the expression of inflammatory mediators
• Initial phase, overuse is considered the primary causal factor
  • Mechanical loading exceeds the tendon's adaptive capacity
• Activation of inflammatory pathways
  • Includes proinflammatory cytokines, prostaglandins, growth factors, and neuropeptides
  • Neovascularization occurs early in the disease process
• Early tendinopathy (within the first 1-3 months) demonstrates tendon enlargement
  • Approximately 25% increase in cross-sectional area, accompanied by hypervascularization detected on Doppler ultrasound

Chronic Quadriceps Tendinopathy

• Characterized by degenerative changes with disorganized collagen
  • As well as increased extracellular matrix, and cellular alterations rather than classical inflammation
• Driven by a self-perpetuating inflammatory–degenerative loop, where mechanical strain activates tenocytes to release cytokines
• Macrophage-mediated fibrosis and aberrant cell differentiation fuel progression
• Neurovascular and immune activity persist even in chronic disease

Jumper's Knee

• May refer to:
  • Quadriceps Tendinopathy
  • Patellar Tendinopathy is the more classic attribution, which is reviewed seperately
  • Affects proximal Patellar Tendon (65%), Quadriceps Tendon (25%) and patelar insertion on tibial tuberosity (10%)
  • Note: There is a lot of overlap in the literature on these subjects, and although distinct entities, not always referred to separately

Etiology

• Most commonly seen in athletes due to chronic degenerative tendon changes from repetitive loading, stress, and extension of the knee
• Occur with chronic overuse and overloading due to jumping and running activities
• May be associated with increase or change in athletic activities or intensity

Associated Conditions

• Patellar Tendinopathy

Anatomy of the Quadriceps Tendon

• Quadriceps Femoris or Quad Tendon
  • Formed by the confluence of Rectus Femoris, Vastus Lateralis, Vastus Intermedius, Vastus medialis
  • Inserts into proximal pole of Patella
  • Primary Function: Extension of the knee
  • Additional functions: hip flexion (rectus femoris), internal and external rotation (VM and VL), hamstring antagonist
• Articularis Genus
  • Small, flat muscle deep to quadriceps
  • Helps tighten synovial membrane during knee extension

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Risk Factors

Demographic and Anthropometric

• Male > female (need citation)
• Age related changes
• Middle age, particularly women
• Obesity, higher body mass index
• Shorter stature or very tall stature

Sports

• Volleyball (most common)
• Basketball
• Handball
• Track and field, especially high jump and long jump
• Field hockey
• Korball
• Soccer

Anatomical and Biomechanical

• Eccentric muscle use
• Muscle imbalance, weakness
• Poor hamstring flexibility
• Malalignment
• Abnormal patellar height (both patella alta and patella baja)
• Trochlear dysplasia
• Dominant kicking leg

Previous Injury

• Previous quadriceps muscle injury
• Recent hamstring strain injury

Systemic Medical Conditions

• Diabetes Mellitus
• Hypertension
• Chronic renal failure
• Hyperparathyroidism
• Gout
• Collagen vascular disease
• Inflammatory enthesopathies
• Endocrine disorders
• Rheumatologic disorders

Training and Activity

• Increased frequency of weight training
• Increased frequency of jump training
• Mechanical overload and repetitive loading
• Improper activity or exercise form
• Inappropriate use of equipment
• Lack of protective gear
• Greater weekly mileage
• Preseason period
• Competitive match play

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Differential Diagnosis

Differential Diagnosis Knee Pain

• Fractures
  • Distal Femur Fracture
  • Patellar Fracture
  • Tibial Plateau Fracture
  • Proximal Fibula Fracture
• Dislocations & Subluxations
  • Patellar Dislocation (and subluxation)
  • Knee Dislocation
  • Proximal Tibiofibular Joint Dislocation
• Muscle and Tendon Injuries
  • Quadriceps Contusion
  • Iliotibial Band Syndrome
  • Quadriceps Tendonitis
  • Quadriceps Muscle Strain
  • Patellar Tendonitis
  • Popliteus Tendinopathy
  • Extensor Mechanism Injury
    • Patellar Tendon Rupture
    • Quadriceps Tendon Rupture
    • Patellar Fracture
• Ligament Pathology
  • ACL Injury
  • PCL Injury
  • MCL Injury
  • LCL Injury
  • Meniscal Pathology
  • Posterolateral Corner Injury
  • Multiligament Injury
• Arthropathies
  • Knee Osteoarthritis
  • Septic Arthritis
  • Gout
  • Synovial Osteochondromatosis
• Bursopathies
  • Prepatellar Bursitis
  • Pes Anserine Bursitis
  • MCL Bursitis
  • Infrapatellar Bursitis
• Patellofemoral Pain Syndrome (PFPS)/ Anterior Knee Pain)
  • Chondromalacia Patellae
  • Patellofemoral Osteoarthritis
  • Osteochondral Defect Knee
  • Plica Syndrome
  • Infrapatellar Fat Pad Impingement
  • Patellar Instability
• Neuropathies
  • Saphenous Nerve Entrapment
• Other
  • Bakers Cyst (Popliteal Cyst)
  • Patellar Contusion
  • Pellegrini Stieda Syndrome
  • Parameniscal Cyst
• Pediatric Considerations
  • Patellar Apophysitis (Sinding-Larsen-Johnansson Disease)
  • Patellar Pole Avulsion Fracture
  • Tibial Tubercle Avulsion Fracture
  • Tibial Tuberosity Apophysitis (Osgood Schalatters Disease)
  • Proximal Tibial Metaphyseal Fracture
  • Proximal Tibial Physeal Injury

Differential Diagnosis Thigh Pain

• Fractures
  • Femoral Shaft Fracture
  • Femoral Shaft Stress Fracture
  • Distal Femur Fracture
• Muscle and Tendon
  • Quadriceps Tendonitis
  • Quadriceps Contusion
  • Quadriceps Tendon Rupture
  • Hamstring Strain
  • Hamstring Tendonitis
  • Adductor Strain
  • Adductor Tendinopathy
  • Rectus Femoris Muscle Injuries
• Neurological
  • Meralgia Paresthetica
  • Obturator Neuropathy
• Other
  • Myositis Ossificans
  • Acute Compartment Syndrome
  • Osteitis Pubis

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Clinical Features

Illustration of straight leg raise test with positive Braggard Sign

History

• Onset is often insidious and progressive, May be acute onset
• Patient will endorse anterior thigh or knee pain but should localize to the quadriceps tendon
• Pain is worse with: Load-related pain during activities such as running, jumping, stair climbing, or squatting
  • Stair climbing is classically painful, going up is worse than going down
• Tendon might feel stiff, especially at the start of motion
• Limitation in activities requiring knee extension

Physical Exam: Physical Exam Knee

• Tendon swelling or thickening may or may not be present
  • Compare to the contralateral side
  • Look for quadriceps muscle atrophy
• Tenderness on distal quadriceps muscle or proximal patellar pole
• Range of motion should be relatively normal
• Pain and sometimes weakness with resisted knee extension

Special Tests

• There are no widely validated, specific provocative tests for quadriceps tendinitis
• Straight Leg Raise: should be intact; inability to lift leg with knee in extension suggests extensor tendon lesion

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Evaluation

Long axis, in plane sonogram of quadriceps tendon. Side by side comparison of the asymptomatic tendon (normal thickness) and symptomatic tendon (thicker, more hypoechoic and shows power doppler flow signals).

Sagittal CT scan view of the ossification of the left quadriceps tendon (superior patella enthesopathy, arrowhead)

General

• Imaging is not required to make the diagnosis
• The diagnosis is primarily clinical
• However, imaging can help exclude other pathology or co-occuring injuries

Radiographs

• Standard Radiographs Knee
  • Routine screening tool to evaluate for other pathology
  • Typically normal
• May demonstrate
  • Enthesopathy or osteophyte formation at proximal patellar pole
  • Calcification of quadriceps tendon
• Patella Baja
  • Can occur in complete tear
  • Inferior migration of patella due to intact patella tendon

MRI

• General
  • Not required to make the diagnosis
  • Imaging modality of choice for a comprehensive MSK evaluation of the knee
  • Between 75-90% of asymptomatic basketball players had MRI findings of quadriceps tendinopathy
• MRI findings include:
  • Increased tendon thickness
  • Intratendinous signal intensity changes
  • Tendon discontinuity in partial or complete tears
  • Peritendinous edema

Ultrasound

• May demonstrate
  • Hypoechoic or hyperechoic changes
  • Neovascularization
  • Increased baseline tendon thickness
  • Loss of fiber visibility
  • Increased power doppler signals
  • Hematoma (sprains, partial tears)
• Findings can be seen in asymptomatic patients
  • Asymptomatic patients have a 3.3 OR of developing symptoms
• Diagnostic accuracy for patallar tendinopathy (diagnsotic accuracy/ sensitivity/ specificity)
  • Grey-scale US (60%/ 72.5%/ 43.3%)
  • Power Doppler (50%/ 12.5%/ 100%)
  • US elastography (62%/ 70%/ 53.3%)
  • Grey-scale + elastrography had a sensitivity of 82.5%, diagnostic accuracy of 61.4%
  • Grey-scale + doppler had a sensitivity of 72.5%, diagnostic accuracy of 60.0%
• Compared to MRI, US has a higher
  • Diagnostic Accuracy (83% vs. 70%; P=0.04)
  • Sensitivity (87% vs. 57% P=0.01)

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Classification

Modified Blazina Classification for Tendinopathy

• Stage 0: no pain
• Stage 1: pain only after intense sports activity with no functional impairment
• Stage 2: moderate pain during sports activity with no restriction on sports performance
• Stage 3: pain with slight restriction on performance
• Stage 4: pain with severe restriction of sports performance
• Stage 5: pain during daily activity and unable to participate in sport at any level

Muscle Strain Classification

• Grade I
  • Injury: minor tearing
  • Symptoms: mild-moderate pain, full strength, no defect
• Grade II
  • Injury: more severe tearing
  • Symptoms: significant pain, decreased strength, possible defect
• Grade III
  • Injury: complete tear (see: Quadriceps Tendon Rupture)
  • Symptoms: inability to extend knee, significant pain

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Management

Low level laser therapy for quad tendonitis

Visual depiction of progressive tendon-loading exercise and eccentric exercise protocol

Nonoperative

• Indications
  • Virtually all cases
• First line therapy
  • Activity modification
  • Relative rest
  • Pain control including NSAIDS, Acetaminophen, possibly Oral Corticosteroids
  • Early initiation of rehabilitative exercises
• Physical Therapy
  • Mainstay and most consistently effective treatment
  • Emphasis on eccentric exercises, quadriceps stretching
• Topical Nitroglycerin

Therapeutic modalities

• Iontophoresis
• Phonophoresis
• Therapeutic Ultrasound
• Ice Therapy
  • Despite lack of high-quality evidence, has a role in controlling pain.
• Low Level Laser Therapy
• Extra Corporeal Shockwave Therapy
  • Helpful when combined with a structured physical therapy program

Procedures

• General
  • No corticosteroids
  • Consider autologous whole blood, platelet rich plasma, stem cell therapy
  • Consider needle tenotomy
• Distal Quadriceps Injection and Tenotomy
  • Indication: refractory to conservative management
• Platelet Rich Plasma
  • Superior to dry needling at 12 weeks with no difference at 26 weeks
  • In Blazina grade III, PRP was superior to physical therapy for sport activity, pain at 6 months
• Sclerosing Polidoconol
  • Hoksrud et al Compared to lido/epi controls, patients with patellar tendinopathy had significant improvements in knee function, pain reduction after Polidocanol at 4 months
  • No difference was noted at 12 months
• Dextrose Prolotherapy

Operative

• Indications
  • Failure of conservative management for minimum of 6-12 months
  • Calcific tendinopathy more likely to require surgical intervention
• Technique
  • No consensus on best technique
  • Arthroscopic vs open shaving

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Rehab and Return to Play

Quad tendonitis rehab exercises

Early rehabilitation exercises for quad tendonitis

Rehabilitation

• Phase I (initial management)
  • Focuses on pain modulation, inflammation control, restoration of range of motion, activity modification, and gait training
  • Ice and other physical modalities are recommended in combination with the exercise program
• Phase II (progressive loading)
  • Emphasis: achieve full range of motion, normal gait pattern, initiating progressive strengthening
  • Particular focus on eccentric quadriceps exercises, the cornerstone of rehabilitation
  • Should also incorporate flexibility training, proprioception retraining, and appropriate cardiovascular conditioning
• Phase III (return to function)
  • Functional return to prior activity level through sport-specific functional progression
  • Advanced strengthening, retraining of sport-specific function, gradual reintroduction of activities that stress the quadriceps tendon
  • Rehabilitation may require a prolonged period—both athlete and clinician must be patient and persistent

Exercise Rehab Program PDFs

• Quadriceps Tendonitis Exercise Program PDF
• Home Exercises for Patellar Quadriceps Tendinitis PDF
• Quadriceps Rehab Exercises PDF
• Quadriceps Tendonitis Patient Guide PDF

Return to Play

• General
  • Return to sport follows a continuum-based approach with ongoing risk assessment
  • Requires restoration of strength, function, and sport-specific skills without pain
  • Return to play or full activity is typically reported at 4-6 weeks following interventions with signficant variability
• Return to play process
  • Ongoing assessment of anatomical, physiological, functional, and psychological readiness
  • Restoration of function of the injured tendon; overall musculoskeletal and cardiovascular function
  • Sport-specific assessment and training to serve as basis for sport-specific conditioning
  • Continued communication among the athlete, rehabilitation team, and coaches
  • Documentation of progress and decision-making

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Complications and Prognosis

Prognosis

• Nonoperative treatment is generally successful at providing symptomatic relief
• Kettunen et al followed 20 athletes with quadriceps tendinopathy for 15 years found
  • Higher mean visual analog scale scores for knee pain with squatting
  • Increased functional limitations measured by Kujala score
  • Increased early retirement of their sports careers because of their knee problems 9 (53%) vs. 1 (7%)
• Ferretti et al evaluated 172 athletes with patellar tendinopathy
  • All patients had good outcomes in early stages of the disease
  • In some cases, a prolonged period of rest, reduction of sporting activity was required
  • 16 Patients with Blazina stage 3 or 4 required surgical intervention of which 12 had good outcomes
• Willberg et al compared scleroising pilodocanol to arthroscopic shaving in patients with patellar tendinopathy
  • Compared to the polidocanol injection group, the arthroscopic treatment group had significant improvements in pain at rest, pain with activity, as well as increased patient satisfaction
• Ferretti et al followed 32 surgical cases of refractory patellar tendinopathy with a minimum of 5 years of follow up
  • Technique: longitudinal splitting of the tendon, excision of abnormal tissue, and resection and drilling of the inferior pole of the patella.
  • Final follow up: good or excellent results 28 (85%) knees, excellent in 23 (71%), good in 5 (16%), fair in 1 (3%), and poor in 4 (13%),
  • 80% of the unsatisfactory results were in volleyball players.
  • Eighteen patients (82%) were able to return to sports at a mean of approximately 6 months postop, of those, 11 (63%) were asymptomatic.

Complications

• Re-injury/ recurrence
  • Reinjury rates can be as high as 67% in severe proximal tears
• Quadriceps Rupture
  • Can be seen in patients with severe tendinopathy that goes untreated
• Chronic knee pain
• Inability to return to sport
• Functional impairment
• Prolonged rehabilitation

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See Also

Internal

• Knee Anatomy (Main)
• Knee Pain (Main)
• Physical Exam Knee

External

• https://mededcases.com/chronic-quadriceps-tendonitis/

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