Knee Disorders Dr Mohammad Hamdan Patellar Tendinitis Definition

Knee Disorders Dr. Mohammad Hamdan

Patellar Tendinitis • Definition • • • activity-related anterior knee pain associated with focal patellar-tendon tenderness also known as "jumper's knee" Epidemiology • incidence • up to 20% of jumping athletes • demographics / risk factors • males > females • volleyball most common • more common in adolescents/young adults • quadriceps tendinopathy is more common in older adults • poor quadriceps and hamstring flexibility • Pathophysiology • mechanism • repetitive, forceful, eccentric contraction of the extensor mechanism • histology • degenerative, rather than inflammatory • micro-tears of the tendinous tissue are commonly seen

Presentation • Symptoms • insidious onset of anterior knee pain at inferior border of patella • initial phase • pain following activity • late phase • pain during activity • pain with prolonged flexion ("movie theater sign") • Physical exam • inspection • may have swelling over tendon • palpation • tenderness at inferior border of patella • provocative tests • Basset's sign • tenderness to palpation at distal pole of patella in full extension • no tenderness to palpation at distal pole of patella in full flexion

Imaging • Radiographs • recommended views • AP, lateral, skyline views of knee • findings • usually normal • may show inferior traction spur (enthesophyte) in chronic cases • Ultrasound • findings • thickening of tendon • hypoechoic areas • MRI • indications • chronic cases • surgical planning • findings • tendon thickening • more diagnostic than presence of edema • increased signal intensity on both T 1 and T 2 images • loss of the posterior border of fat pad in chronic cases

Treatment • Nonoperative • ice, rest, activity modification, followed by physical therapy • indications • most cases • technique • physical therapy • stretching of quadriceps and hamstrings • eccentric exercise program • ultrasound treatment may be helpful • taping or Chopat's strap can be used to reduce tension across patellar tendon • cortisone injections • are contraindicated due to risk of patellar tendon rupture • Operative • surgical excision and suture repair as needed

Quadriceps Tendonitis • Inflammation of the suprapatellar tendon of the quadriceps muscle • Epidemiology • demographics • 8: 1 male-to-female ratio • more common in adult athletes • risk factors • jumping sports • basketball • volleyball • athletics (e. g. , long jump, high jump, etc

Presentation • History • • Symptoms • • overuse injury in a jumping athlete recent increase in athletic demands or activity often a recurring injury pain localized to the superior border of patella worse with activity associated swelling Physical examination • inspection • knee alignment • swelling • palpation • tenderness to deep palpation at quadriceps tendon insertion at the patella • palpable gap would suggest a quads tendon tear • patellar subluxation • motion • pain with resisted open chain knee extension • able to actively extend the knee against gravity

Imaging • Radiographs • • recommended views • AP and lateral of knee optional views • Sunrise or Merchant views for patella instability findings • usually normal • may see tendon calcinosis in chronic degeneration measurement • evaluate knee alignment for varus/valgus angle • evaluate for patellar height (patella alta vs baja) for suspected quadriceps tendon rupture • • • Ultrasound • • • Blumentsaat's line should extend to inferior pole of the patella at 30 degrees of knee flexion Insall-Salvati method • normal between 0. 8 and 1. 2 indications • suspected acute or chronic findings • effective at detecting and localizing disruption in tendon • operator and user-dependent MRI • • indications • most sensitive imaging modality findings • intrasubstance signal and thickening of tendon

Treatment • Nonoperative • activity modification, NSAIDS, and physical therapy • indications • mainstay of treatment • technique • rest until pain is improved • physical therapy starting with range of motion and progressing to eccentric exercises • cortisone injections contraindicated due to risk of quadriceps tendon rupture • Operative • quadriceps tendon debridement • indications • very rarely required

Patellar Instability • Can be classified into the followingacute traumatic • occurs equally by gender • may occur from a direct blow (ex. helmet to knee collision in football) • chronic patholaxity • recurrent subluxation episodes • occurs more in women • associated with malalignment • habitual • usually painless • occurs during each flexion movement • pathology is usually proximal (e. g. tight lateral structures - ITB and vastus lateralis)

Presentation • Symptoms • • • complaints of instability anterior knee pain Physical exam • acute dislocation usually associated with a large hemarthrosis • absence of swelling supports ligamentous laxity and habitual dislocation mechanism • • medial sided tenderness (over MPFL) increase in passive patellar translation • measured in quadrants of translation (midline of patella is considered "0"), and also should be compared to contralateral side • normal motion is <2 quadrants of patellar translation • • lateral translation of medial border of patella to lateral edge of trochlear groove is considered "2" quadrants and is considered abnormal amount of translation patellar apprehension • passive lateral translation results in guarding and a sense of apprehension • • increased Q angle J sign • excessive lateral translation in extension which "pops" into groove as the patella engages the trochlea early in flexion • associated with patella alta

Imaging • Radiographs: • rule out fracture or loose body • medial patellar facet (most common) • lateral femoral condyle • MRI help further rule out suspected loose bodies • • osteochondral lesion and/or bone bruising medial patellar facet (most common) lateral femoral condyle tear of MPFL • tear usually at medial femoral epicondyle

Treatment

Nonoperative • NSAIDS, activity modification, and physical therapy • indications • mainstay of treatment for first time patellar dislocator • without any loose bodies or intraarticular damage • habitual dislocator

Operative • Arthroscopic debridement (removal of loose body) vs Repair with or without stabilization • indications • displaced osteochondral fractures or loose bodies • may be an indication for operative treatment in a first-time dislocator • MPFL repair • indications • acute first time dislocation with bony fragment • MPFL reconstruction with autograft vs allograft • indications • recurrent instability • no significant underlying malalignment • Fulkerson-type osteotomy (anterior and medial tibial tubercle transfer) • tibial tubercle distalization • lateral release

Lateral Patellar Compression Syndrome • Improper tracking of patella in trochlear groove • Caused by tight lateral retinaculum • leads to excessive lateral tilt without excessive patellar mobility • Miserable Triad • is a term coined for anatomic characteristics that lead to an increased Q angle and an exacerbation of patellofemoral dysplasia. They include: • femoral anteversion • genu valgum • external tibial torsion / pronated feet

Presentation • pain with stair climbing • theatre sign (pain with sitting for long periods of time) • Physical exam • pain with compression of patella and moderate lateral facet tenderness • inability to evert the lateral edge of the patella

Imaging • Radiographs • patellar tilt in lateral direction

Treatment • Nonoperative • NSAIDS, activity modification, and therapy • indications • mainstay of treatment and should be done for extensive period of time • technique • therapy should emphasize vastus medialis strengthening and closed chain short arc quadriceps exercises • Operative

Idiopathic Chondromalacia Patellae • Condition characterized by idiopathic articular changes of the patella • term is now falling out of favor • more commonly grouped together with a number of pathological entities known as • "anterior knee pain" or • "patellofemoral syndrome"

Presentation • Symptoms • • • diffuse pain in the peripatellar or retropatellar area of the knee (major symptom) insidious onset and typically vague in nature aggravated by specific daily activities including • climbing or descending stairs • prolonged sitting with knee bent (known as theatre pain) • squatting or kneeling • • always consider the physical, mental and social elements of knee pain Physical exam • • quadricep muscle atrophy signs of patella maltracking • increased femoral anteversion or tibial external rotation • lateral subluxation of patella or loss of medial patellar mobility • positive patellar apprehension test • • palpable crepitus pain with compression of patella with knee range of motion or resisted knee extension

Imaging • Radiographs • recommended views • AP, lateral and notch radiographs of knee • findings • may see chondrosis on xray • shallow sulcus, patella alta/baja, or lateral patella tilt • CT scan • indications • patellofemoral alignment • fracture • findings • trochlear geometry • TT-TG distance • torsion of the limb • MRI • indications • best modality to assess articular cartilage • views • T 2 best sequence to assess cartilage • abnormal cartilage is usually of high signal compared to normal cartilage

Treatment • Nonoperative • rest, rehab, and NSAIDS • indications • mainstay of treatment and should be done for a minimum of one year • technique • NSAIDS are more effective than steroids • activity modification • rehabilitation with emphasis on • vastus medialis obiquus strengthening • core strengthening • closed chain short arc quadriceps exercises • strengthening of hip external rotators • Operative

Quadriceps Tendon Rupture • • • Rupture of the quadriceps tendon leading to disruption in the extensor mechanism Epidemiology incidence • • demographics • • usually occurs in patients > 40 years of age males > females (up to 8: 1) occurs in nondominant limb more than twice as often location of rupture • • quadriceps tendon rupture is more common than patellar tendon rupture usually at insertion of tendon to the patella risk factors • • renal failure diabetes rheumatoid arthritis hyperparathyroidism connective tissue disorders steroid use intraarticular injections (in 20 -33%)

Presentation • History • often report a history of pain leading up to rupture consistent with an underlying tendonopathy • Symptoms • pain • Physical exam • tenderness at site of rupture • palpable defect usually within 2 cm of superior pole of patella • unable to extend the knee against resistance • unable to perform straight leg raise with complete rupture

Imaging • Radiographs • recommended views • AP and lateral of knee • findings • will show patella baja • MRI • indications • when there is uncertainty regarding diagnosis • helps differentiate between a partial and complete tear

Treatment • Nonoperative • knee immobilization in brace • indications • partial tear with intact knee extensor mechanism • patients who cannot tolerate surgery • Operative • primary repair with reattachment to patella • indications • complete rupture with loss of extensor mechanism

Patella Tendon Rupture • • Disruption of the tendon attaching the patella to the tibial tubercle (the patella is a sesamoid bone making this a tendon, not a ligament) Epidemiology • incidence • • demographic • • • most commonly in 3 rd and 4 th decade male > female location • • < 0. 5% of the US population per year quadriceps tendon rupture > patella tendon rupture risk factors • weakening of collagen structure • • • systemic • systemic lupus erythematous • rheumatoid arthritis • chronic renal disease • diabetes mellitus local • patellar degeneration (most common) • previous injury • patellar tendinopathy other • corticosteroid injection

Presentation • History • • Symptoms • • sudden quadriceps contraction with knee in a flexed position (e. g. , jumping sports, missing step on stairs) infrapatellar pain popping sensation difficulty weight-bearing Physical exam • inspection • • • elevation of patella height usually associated with a large hemarthrosis and ecchymosis localized tenderness palpable gap below the inferior pole of the patella motion • unable to perform active straight leg raise or maintain passively extended knee • reduced ROM of knee (and difficulty bearing weight) due to pain • if only tendon is ruptured and retinaculum is intact, active extension will be possible but will have extensor lag of a few degrees

Imaging • Radiographs • recommended views • • optional views • • patella alta seen in complete rupture knee in flexion (ideally 30 degrees), the Insall-Salvati ratio is > 1. 2 Ultrasound • indications • • suspected acute and chronic injuries findings • • • merchant or skyline findings • • • AP and lateral of the knee effective at detecting and localizing disruption operator and user-dependent MRI • indications • • • differentiate partial from complete tendon rupture most sensitive imaging modality findings • site of disruption, tendon degeneration, patellar position, and associated soft tissue injuries

Treatment • Nonoperative • immobilization in full extension with a progressive weight-bearing exercise program • indications • partial tears with intact extensor mechanism • modalities • • • application of a removable knee splint early knee range of motion Operative • primary repair • indications • • complete patellar tendon ruptures ability to approximate tendon at site of disruption • techniques • • end-to-end repair transosseous tendon repair suture anchor tendon repair tendon reconstruction • indications • severely disrupted or degenerative patella tendon • techniques • semitendinosus or gracilis tendon autograft

Articular Cartilage Defects of Knee • Spectrum of disease entities from single, focal defects to advanced degenerative disease of articular (hyaline) cartilage

Presentation • History • commonly present with history of precipitating trauma • some defects found incidentally on MRI or arthroscopy • Symptoms • asymptomatic vs. localized knee pain • may complain of effusion, motion deficits, mechanical symptoms (e. g. , catching, instability) • Physical exam • inspection • look for background factors that predispose to the formation of articular defects • joint laxity • malalignment • compartment overload • motion • assess range of motion, ligamentous stability, gait

Imaging • Radiographs • indications • used to rule out arthritis, bony defects, and check alignment • recommended views • standing AP, lateral, merchant views • CT scan • indications • better evaluation of bone loss • MRI • indication • most sensitive for evaluating focal defects

Treatment • Nonoperative • rest, NSAIDs, physiotherapy, weight loss • indications • first line of treatment when symptoms are mild • viscosupplementatoin, corticosteroid injections, unloader brace • indications • controversial • may provide symptomatic relief but healing of defect is unlikely • Operative • debridement/chondroplasty vs. reconstruction techniques