ATRAUMATIC PAINFUL KNEE CONDITIONS Michael Stanton, MD Orthopaedic Surgeon Rochester Regional Health Orthopaedics at Red Creek

Patellofemoral Syndrome  Anterior knee pain  Patellofemoral pain syndrome  Patellar chondromalacia

Patellofemoral Syndrome  Adolescents and young adults  Women > Men  Pain vs. instability  Multiple factors involved Muscle weakness (hip, core, knee) Chondral lesions Patellar maltracking

Symptoms  Diffuse pain in peripatellar or retropatellar region  Gradual onset  Worse with activities Stairs Prolonged sitting with knee bent Squatting/kneeling

Exam  Range of motion  Patellar translation/instability  Quad atrophy  Hip/core weakness  Crepitus with ROM  Pain with compression of patella

Why does it hurt?  Dye et al. – “Conscious neurosensory mapping of the internal structures of the human knee without intraarticular anesthesia.” Fat pad and synovium very sensitive Articular surface, meniscus, ligaments much less sensitive Articular cartilage aneural but subchondral bone has potential to generate pain

Treatment  Non-operative management NSAIDs, ice, activity modification Isolated VMO strengthening??? Hip/core/knee strengthening Closed chain exercises  Operative management Lateral release Patellar realignment surgery for instability

Patellar/Quad Tendonitis  “Jumper’s knee, runner’s knee” Younger athletic population  Quadriceps tendonitis More common in older population  Risk factors Quad weakness Hamstring/Quad tightness

Physical Exam  Tenderness to palpation at inferior pole of patella  Assess flexibility  Patellar tracking

Treatment  Non-operative Rest, ice, activity modification, physical therapy Chopat’s strap Avoid corticosteroid injections  Operative Debridement and repair of tendon

Osteochondritis Dissecans  Lesion involving articular cartilage and subchondral bone  Two forms based on age Juvenile (open growth plates) Adult  Most common location posterolateral aspect of medial femoral condyle (70%)

Osteochondritis Dissecans  Unclear etiology in most cases Adult form thought to be due to vascular insult  Often found incidentally  Can lead to softening of cartilage, partial detachment, and separation with loose bodies  Prognosis strongly correlated with age (open physes)

Osteochondritis Dissecans  Vague activity related pain  Recurrent effusions  Mechanical symptoms indicate late disease  Wilson’s Test Pain with internally rotating tibia between 30°-90°, relieved with external rotation

Operative Treatment  Depends on stage of disease and size of lesion Subchondral drilling Fixation of unstable lesion Debridement and microfracture Loose body removal Osteochondral transplant

Loose Bodies  Pain and intermittent catching/locking  Sometimes palpable  Cartilage fragment  Arthroscopic removal for failed non-operative treatment

Septic Arthritis  Knee is most common joint ~50% of cases  3 etiologies of seeding of joint Bacteremia Direct inoculation (trauma/surgery) Contiguous spread (adjacent osteomyelitis)  Most common organism – staph aureus  Symptoms Red, hot, swollen joint Unable to tolerate motion/weight bearing Fevers (60%)

Septic Arthritis  Joint aspiration Gram stain – shows organism 1/3 of the time Cell count >50,000 considered diagnostic  Surgical emergency  Open or arthroscopic debridement effective  Antibiotic treatment

Thank You