Knee Differential Diagnosis

Knee Differential Diagnosis

1. NON-SPECIFIC and OTHER

   • Infection
     • Osteomyelitis
     • Septic Arthritis

2. MYOGENIC

   • Muscles
     • Gastrocnemius Tendinopathy
       • 1 Local tenderness// 2 Pain on resisted knee flexion, calf raises, jumping, hopping etc// 3 Gastroc stretch reproduces pain occasionally
     • Biceps Femoris Tendinopathy
       • 1 Occurs with rapid acceleration/deceleration activities// 2 Pain produced on resisted flexion, especially with eccentric contractions
   • Tendons
     • Patellar Tendinopathy
       • 1 Anterior knee pain localised to the inferior pole of the patella// 2 Pain aggrevated by loading and increased demand on knee extensor muscles// 3 Patient may complain of pain with prolonged sitting, stairs, squatting// 4 Pain rarely experienced during rest, and occurs instantly with loading in a dose-dependant mannor
   • Other Soft Tissue
     • IT Band
       • 1 Tenderness on the lateral aspect of the knee// 2 Burning pain at the level of the lateral femoral epicondyle// 3 Sharp pain on the outer aspect of the knee that can radiate into the outer thigh or calf// 4 Exercise related tenderness// 5 Overuse of glut. max can put strain on the IT Band and present with lateral knee pain
     • Pes Anserinus Bursitis
       • 1 Presents on medial aspect of the knee// 2 Region will be swollen and tender to touch// 3 Decreased muscle strength and ROM
     • Fat Pad Syndrome
       • 1 Pain in the front of the knee, with swelling below and around the knee // Pain when fully extending the knee // 3 Pain with prolonged walking, squatting and kicking

3. NEUROGENIC

   • Lx Referred Pain
     • Pain from the Lx spine may be referred to the lateral knee. Slump test may be positive

4. ARTHROGENIC

   • OA
     • 1 Presents with activity-related joint pain, morning stiffness lasting <30 minutes, aged 45+// 2Pain is related to use, relieved with rest// 3 Modest swelling, crepitus during AROM
   • Ligaments
     • ACL
       • 1 MOI- Foot planted with a sudden change in direction/speed// 2 Audible pop/crack at the time // 3 Immediate swelling in area// 4 Episodes of giving way// 5 Restricted movement
     • PCL
       • 1 MOI- often a direct blow to the anterior aspect of the proximal tibia on a flexed knee, with the ankle in plantarflexion// 2 Pain, rapid swelling within hours, knee feels lose and unstable
     • MCL
       • 1 Tender to touching some swelling may be present// 2 Grade 3 tears result in knee instability// 3 Stress test
     • LCL
       • 1 Patient may have heard a 'pop'// 2 Palpation reveals warmth, tenderness, swelling// 3 Knee deformity and bruising may be evident// 4 Stress test
   • Meniscus
     • 1 Meniscal tears can present with knee locking, popping and clicking// 2 Symptoms worsen by flexing and loading the knee eg squatting and kneeling// 3 Joint line tenderness
   • Patella
     • Patello-Femoral Pain
       • 1 Commonly affects adolescents and individuals with high activity levels// 2 Gradual onset of pain around/behind the patellaaggrevated by PF joint loading activities eg squatting, stairs, running// 3 Tenderness on palpation of patellar facets alongside some swelling// Crepitus originating from the PF joint
     • Patella Dislocation
       • 1 MOI- Upon twisting/jumping, knee "gave way" along with severe pain// 2 "popping out"// 3 Immediate swelling// 4 Gross swelling, marked tenderness over medial border of patella, aggravated pain upon quadriceps contraction