Presenter : Dr. Sushil Paudel

Introduction

Common clinical problem

Refers to pain in anterior region of knee

It is a symptom not a diagnosis

Mid 1970’s - Sports medicine

Patellofemoral components are subjected to the highest loads within the knee

Definition

‘A syndrome characterized by dysfunction and pain expressed in the anterior region of the knee. Signs and symptoms are variable and multiple tissue sources and etiologies exist’.

It has been referred as

Patellofemoral pain syndrome / chondromalacia patellae / recalcitrant anterior knee pain / patellae femoral stress syndrome / femoropatellar pain syndrome / patellofemoral arthralgia or patellagia

Patellofemoral Anatomy

Femur

Trochlear groove between Med and Lat femoral condyles

Lat wall is more prominent

Abnormalities of groove - lateral tracking

Patella Acts as a lever arm -

increase function of quadriceps

Decrease functional load and abrasions on the anterior soft tissues

Thickest articular cartilage of any human joint

Central ridge ◦ Longer lateral facet -

Superior, interior and middle

◦ Shorter medial facet ‘Odd’ facet - medially

non-load bearing except in extreme flexion

Articulation0°-No contact

20°-Inferior facet - upper trochlear groove

45°-Middle facet - mid portion of trochlear

90°-Superior facet - lower trochlear articular cartilage

135°-Lateral medial and odd facet

Along with undersurface of quadriceps

Quadriceps and other soft tissues

Rectus femoris tendon - superior pole

Vastus medialis obliqus (VMO)◦ Superomedial border◦ Primary stabilizer of patella

medially against VL Vastus lateralis

◦ Superolateral border◦ Lateral retinaculum◦ Lateral patellofemoral lig

Medial PF lig is weaker than lat

Medial and lateral retinaculum

Iliotibial band

Biomechanics Often termed ‘Extensor mechanism’ Resultant force of both quadriceps

and patellar tendon vectors - ‘Patellofemoral joint reaction force’ (PFJR) force

Directly related to quadriceps force generation (M1\M2)

Increase as the angle of flexion increases

Load decrease - straight leg raising and swimming

Increase in - Flexion activities like - climbing up and down stains, squatting, jumping, running and tennis, soccer etc.

Quadriceps ‘Q’ angle

‘Angle between line of application of quadriceps force and direction of patellar tendon in coronal plane’

Normal ◦ Males 10 - 12°

◦ Females 15 - 18°

- Greater pelvic width

- Short femoral length

Normally has a valgus patellofemoral vector

Greatest at full extension - External rotation of tibia

Factors resisting the normal lateral vector

of patella

Deeper PF trochlea

Large lateral femoral condyle

VMO - inserted more distally and horizontally than VL

Factors predispose subluxation

Deficiency of intercondylar sulcus

Deficiency of VMO Increase in ‘Q’ angle

◦ Internal femoral torsion◦ External tibial torsion◦ Genu valgum

Patella alta Patella baja Excessive pronation of

foot Tight lateral

retinaculum

ClassificationInsall - based on amount and extent of articular

cartilage damage Presence of cartilage damage

◦ Chondromalacia patellae◦ Osteoarthritis◦ Direct trauma◦ Osteochondral fractures◦ Osteochondritis dissecans

Variable cartilage damage◦ Subluxation◦ Dislocation◦ Tilt◦ Plicae

Usually normal cartilage◦ Patellar tendinitis (Jumper’s Knee)

◦ Traction apophysitis Patella - Sinding - Larsen Johansson disease

Tibial tubercle - osgood - Schlatter disease

◦ Prepatellar bursitis (Housemaid’s knee)

◦ Hoffa’s (infrapatellar fat pad) syndrome

◦ Patellar anomalies

◦ Reflex sympathetic dystrophy

◦ Iliotibial band friction syndrome

Other causes Referred pain from hip

◦ Perthes disease

◦ Slipped capital femoral epiphysis

Tumor

Gaint cell tumour , others

Post operative causes

◦ Interlocking nailing of tibia

◦ Arthroscopic ACL reconstruction

◦ Total knee replacement

History

Pain

◦ Dull aching, retro patellar, often bilateral

◦ Aggravate - going up and down stairs, squatting, kneeling and sitting with knee flexed (Movie Sign or Theatre ache)

Giving way - subluxation and dislocation

Grating sound on movement of patella, flexion and extension of knee

Mechanisms of PF painOverloading of the subchondral bone

Synovial sourceRetinacular sourceCartilage is aneuric and cannot be source of pain

It has limited power of repair or regenaration once fibrillation or ulceration has occurred

Physical Examination Contralateral “Normal” knee

should also be examined Patient standing - limb

alignment G-varum / G-valgum, femoral or tibial rotation◦ “Squinting” patellae - point

medially Foot-excess pronation Deficient VMO - 30° flexion

Patellar position in sitting◦ Patella alta

Grasshopper eye Camelback sign

Tracking of patella◦ Shape of Hockey Stick ‘J’ Sign

Tenderness Crepitus Q-angle - > 20° abnormal Tubercle sulcus angle > 10°

abnormal Patellar mobility

Tubercle sulcus angleApprehension test Patellar tilt test

Apprehension sign of Fairbanks

Patellar tilt test - retinacular contracture or laxity

Passive and Active lateral glide test

Generalised laxity of other joints

Examination of hip – tenderness, ROM

Examination spine - Straight leg raising

Ober’s test - Iliotibial band contracture, lateral knee pain

◦ Pt stands facing examiner with one leg on stool, other on floor

◦ Hold pt for balance only◦ Pt lifts toes off the floor and

shifts weight to that on stool gradually

◦ He lowers the opp leg to floor trying not to drop last inches

◦ Requires good control of PF extensor mechanism

◦ It applies lot of stress on ant compartment

◦ If pathology –elicits pain and\weakness

IMAGING Anterioposterior

view in full weight bearing on one leg

Posteroanterior view in 45° flexion weight bearing view of Rosenberg - for assessment of articular cartilage loss in posterior compartment

Lateral view◦ Best assessment of

patellar height - Patella alta or baja

◦ Black borne - peel ratio - 1:1 (± 20%)

◦ Insall - salvati ratio - 1:1 (± 20%)

Axial view◦ X-ray beam

perpendicular to film

◦ Knee flexed 30° to 45°

◦ Both knees together

Sulcus angle◦ Between condyles and

sulcus◦ Mean 138° ± 6°◦ Correlates with instability

Congruence angle◦ Zero reference line bisects sulcus

angle◦ Mean 6° ± 6°◦ Measures subluxation

Lateral patellofemoral angle◦ Between intercondylar line

and lateral facet◦ Should open laterally◦ Tilt with subluxation

Patellofemoral index◦ M - closest distance between articular

ridge and medial condyle◦ L - closest distance between lateral facet

and condyleIndicates - Tilt with subluxation

Patellar tilt◦ Angle between transverse plane of patella and a

horizontal line parallel with x-ray table◦ Normal 5° or less◦ Tilt can occur without subluxation◦ Indicates tight lateral retinaculum

Longstanding lateral patellar compression syndrome◦ Pain increases on

flexion of knee◦ Sclerosis of lateral

patellar facet◦ Trabeculae

perpendicular to lateral facet

◦ Lateral traction spur

CT Scan ◦ To evaluate patellar

position and lateral tilt in too obese patient

◦ CT Scan classification of malalignment Type 1 – lateral

subluxation

Type 2 – lateral subluxation with tilt

Type 3 – lateral tilt without subluxation

Type 4 – radiographically normal alignment

MRI

◦Suspected tumour

◦Medial patellofemoral ligament tear

◦No diagnosis can be established Bone scan

◦Reflex sympathetic dystrophy

◦To document progress during treatment

Non-operative treatment of patellofemoral pain

Will be successful in about 90% of cases Rehabilitation program includes

◦ Patient education

◦ Pain modalities RICE

NSAIDS

Ultrasound

TENS Transcutaneous electrical nerve stimulation (Gate

theory)

TREATMENT

◦ Stretching Stretching of tight muscles -

ITB, hamstrings, gastrocnemius and quadriceps

Increasing patellar mobility

Slow sustained, five times on each side for 10 secs.

◦ Strengthening Isometric quadriceps exercises

- VMO strengthening, cycling

Hip adductors and abductors

Never use knee extensors against resistance

Mc Connell - closed chain kinetic exercises and taping of knee

Short arch extensions

Isometric quadriceps

Straight leg raising

Stationary cycling

◦ Extrinsic support - Bracing

Patellar strap - patellar tendinitis

Patellar brace with full ring support with lateral buttress pad - resist lateral vectors

Longitudinal arch supports - medial correction for pronated foot

They effect changes in patellar tracking

Patellar straps

Patellar braces

Surgical Techniques - Needed in 10%

casesArthroscopic patellar

debridement (shaving)

Without a leg holder Minimal portals Conservative -

remove only unstable cartilage

Arthroscopic lateral release Indication - Tight lateral

retinaculum, producing symptoms, not responding to conservative treatment

Proximal Superomedial portal Coagulate lateral superior

geniculate artery Avoid injury to lat meniscus Release until muscle fibers of

Vastus lateralis complication– haemarthrosis, Residual band, post op

scarring Medial subluxation

Patellofemoral malalignment with or without articular degenaration

Medial tibial tubercle transfer

Indicated in large ‘Q’ angle causing symptoms - not responding to non-operative treatment

Combined with arthroscopic lateral release

Cut osteotomy and move proximal end medially correcting ‘Q’ angle

Avoid overcorrection Three screw, bicortical,

lag fixation Avoid injury to anterior

recurrent tibial artery

Proximal quadriceps plasty Indication ‘Q’ angle is normal or has been corrected but patella remain subluxated laterally causing symptom or that recurrently dislocated

Used for moderate alignment Release lower third or half of vastus lateralis and perform derotation quadriceps plasty

Tubulization of extensor tendon

Medial patellofemoral ligament reconstruction

Chronic dislocation of patella Recurrent dislocation in which ligament is absent

or irrepairable Use central area of quadriceps tendon Sutured medial edge of patella Staple over medial epicondyle of femur

Anteromedial tibial tubercle plasty (fulkerson)

Increases the tibial linear arm of extensor mechanism

Reduces patellofemoral joint reaction time

Indicated in Gr III or IV chondromalacia

Anterior transfer is indicated only when the extensor mechanism is already well aligned e.g. in trauma

Articular degeneration in a normally aligned patellofemoral joint

Flat ledge on medial side of tibia

Rotate the tibial tubercle with bone block medially and anteriorly with distal end attached

15-18 mm anterior elevation can obtained

Three screw bicortical lag fixation

Anteriorization (Maquet)◦Bandi and Maquet◦ Increases the efficiency of

quadriceps by increasing the lever arm

◦Decreases the PF joint reaction force

◦Modified Maquet procedure Lateral release Anterior elevation of atLeast 2cm Medialization by appx 1 cm

◦Notched iliac crest graft◦No internal fixation◦Complications

Skin necrosis over tubercle Acute or stress #s DVT Arthrofibrosis Compartment syndrome

Patellectomy Salvage procedure Best done for comminuted

patellar fracture with a normal trochlea

Realign the extensor mechanism

Soto-Hall technique - lateral release and transposition and repair

Vastus medialis advancement

Can do with anteromedial transfer of tubercle

Total patellofemoral

arthroplasty Indications

◦ Isolated patellofemoral arthritis

◦ Trochear chondrosis is present

Extensor mechanism should be aligned

Chrome - Cobalt molybdenum trochlear implant

Modified Mckeever-type prosthesis

Geometry of trochlear implant should be identical with that of femoral component from TKR system by same manufacturer

Rehabilitation

Post-op - 2 main goals Regaining quadriceps strengths Restoring knee flexibility

◦ Extension knee splint (knee immobilizer) for 6 wks◦ Weight bearing with splint - immediately◦ Gradual flexion - Active and passive heel slides◦ Quadriceps exercise - immediately after surgery◦ Assisted straight leg raising - 3 weeks◦ Full straight leg raising - 6 weeks

Complications

Reflex sympathetic dystrophy

Infrapatellar contraction syndrome

Compartment syndromes

Iatrogenic medial subluxation of patella

Loss of correction

plica◦Remnants of Synovial

tissue◦MC – Infrapatellar

(ligamentus mucosum) no clinical significance

◦Next is Suprapatellar – act as tethering band

◦ Medial plica least common – produces most symptom

◦ Incidence 9.1%-50%◦Tenderness one finger

breadth prox to distal pole of patella medially

◦Treatment – NSAIDS, stretching, strengthing,

injection, surgical resection

Prepatellar bursitis◦ Common in wrestlers◦ Cause – acute –trauma

(rupture of vessels) chronic – irritation

(inflammation)◦ High recurrance rate◦ Swelling superficial to

patella◦ High incidence of septic

arthritis (staph aureus)◦ Surgery – thickened bursal

wall◦ Treatment – RICE, NSAIDS,

aspiration, cortisone injection

quadriceps, knee cap pad.

Iliotibial band friction syndrome◦ Common in runners, bikers◦ Symtoms can be at hip, knee or both◦ Pain at - hip – greater trocanter - knee – lat femoral condyle◦ Tight ITB (Obers test) and tight

hamstrings are diagnostic◦ Asses alignment and treat

underlying cause◦ Treatment – ICE, NSAIDS, activity

modification, treat malalignment, flexibility

◦ Surgery – chronic unresponsive cases ‘window’ in ITB in area of irritation

Fat pad syndrome◦ Rare problem , not painful in many

◦ Can be acute or chronic

◦ May be related to malalignment

◦ Squat sitting is painful

◦ Tenderness medial and\or lateral to patellar tendon on fat pad

◦ Treatment – NSAIDS, RICE, cortisone injection, correction of cause, surgical resection

Osgood schlatters disease◦ Tibial tuberosity apophysitis –

result of tensile force◦ Self limiting problem with pain and

enlargement of tibial tuberosity◦ Incidence with sports -20%,

uninvolved -4.5% overall – 12.9%

◦ male:female – 1.5:1 to 4:1◦ Bilateral in 51% average age of

onset 13 years◦ Dull ache increases with running

and jumping with local tenderness

Osgood schlatters disease◦ Etiology - avulsion of

portion of ossification centre

Inflammatory changes sec to micro avulsion fractures of tuberosity

◦ X-ray soft tissue swelling ant to tuberosity

◦ Treatment –ice, NSAIDS, stretching, strengthing, activity modification, rarely immobilize

◦ Complication – tibial tuberosity # (rare) requres surgical resection

Sinding-Larsen-Johansson disease◦ Similar to Osgood’s disease but

symtoms at inferior pole of

patella (with tenderness)◦ Age 10-13 years, no h\o trauma◦ Etiology avulsion of periosteum

at inf pole of patella with ossification or repetitive traction at patellar tendon attachment

◦ X –ray show irregular calcification

◦ Treatment same as Osgood’s disease

Patellar tendinitis and quadriceps tendinitis◦ Blazina referred these as “jumper’s knee”◦ Usually over 40 years◦ Difficult to treat, usually present very late◦ Point tenderness over distal pole of patella◦ Blazina’s phases

Phase 1 – pain after activity only, no functional impairment Phase 2 – pain during and after activity, still able to perform at

a satisfactory level Phase 3 – pain during and after and more prolonged

progressively increases not able to perform satisfactorily◦ Treatment – controlled activites, medications, excersies

Chondromalacia patellae (Runner’s knee)◦ Definition: “it is softening or wearing away and

cracking of the articular cartilage under the patella, resulting in pain and inflammation.”

◦ Acute – direct trauma◦ Chronic – inflammation , repetitive rubbing◦ Resultant force – retro patellar compression

force◦ Increase in ‘Q’ angle – malalignment of patella◦ symptoms-

Ant knee pain while walking, running, squatting, climbing stairs

Recurrent effusion Crepitation or grating on flexion and extension of

knee

Chondromalacia patellae◦ Clinical signs

Crepitation on passive movement of patella

Pain on compression of patella ‘Q’ angle usually>15° Tenderness – along borders and

underside of patella G . Valgum ,external tibial rotation Femoral anteversion combined with

external tibial torsion ( miserable malalignment syndrome )

◦ X ray Patella alta Shallow femoral groove Shallow patellar angle Tilting or gliding of patella

◦ Eisele (1991) grading of cartilage damage Grade 1 - articular cartilage only shows

softening or blistering Grade 2 - fissures appear in cartilage Grade 3 - fibrillation of cartilage occurs,

causing 'crabmeat' appearance Grade 4 - full cartilage defects are present

and subchondral bone is exposed◦Treatment◦ Conservative

modification of activities Patellar tapping Quadriceps strengthing – most important NSAIDS and rest Orthotics and braces

Chondromalacia patellaeChondromalacia patellae

Surgical treatment◦ Shaving◦ Drilling◦ Realignment procedure

Tightening of the medial capsule Lateral releaseMedial shift of tibial tubercle

◦ Chondrectomy◦ Partial\full patellectomy◦ Maquet procedure◦ Patellar prosthesis◦ Future directions – autologous chondrocyte transplantation

for femoral articular surfaces

Chondromalacia patellaeChondromalacia patellae

Conclusion◦ Common problem in this era of sports medicine◦ Can be diagnostic and therapeutic challenge◦ Evalution needs careful history, physical examination and

radiography◦ No single cause or successful solution has been identified◦ Conservative treatment is the cornerstone in

management (90%)◦ Surgery in minority cases (10%)◦ Currently arthroscopic procedures