THE KNEE JOINT
CARE & PREVENTION OF ATHLETIC INJURIESMS. HERRERA
FACTS
A.K.A “TIBIOFEMORAL JOINT”
A hinge joint
ROM: flexion and extension
Unstable laterally and medially
AnatomyBones:
Femur, tibia, fibula, and patella
Muscles:
Biceps femoris, semitendonosis, and semimembranosus
Rectus femoris, vastus medialis, vastus lateralis, vastus intermedius
Sartorius (longest muscle in body) and gastrocnemius
Anatomy Cont’d
Mensicus (you have 2)
Medial mensicus (C-Shaped)
Lateral mensicus (O-shaped)
Made of????
Ligaments (purpose of each?)
Anterior cruciate ligament
Posterior cruciate ligament
Medial collateral ligament
Lateral collateral ligament
Anatomy Cont’d
• Bursae
• As many as 2 dozen in the knee
• Nerve Supply
• Sciatic
• tibial
• Femoral
Medial Collateral Ligament Sprain (MCL)
• MOI: direct blow from lateral side creating excessive valgus stress
• Excessive knee twist
MCL Sprain Cont’d• Categorized into 3
grades
• Signs & Symptoms (depends on grade)
• Ligament fibers torn/stretched
• Pain, swelling (mild-severe)
• TTP over MCL and attachment sites
• Loss of ROM, joint stiffness, weak
• + valgus stress test
• Management
• Conservative tx usually
• Ice, e-stim, ultrasound, rehabilitation
• Surgery is indicated if MCL is sprained along with the ACL or PCL
Lateral Collateral Ligament Sprain
• MOI: Blow to the medial side of the knee causing a varus force
• Signs & Symptoms:
• Pain, TTP over LCL, swelling
• Laxity with varus testing
• Management:
• Same as MCL
Anterior Cruciate Ligament Sprain (ACL)
• Prevents ant. movement of tibia
• MOI: valgus force with tibia in external rotation
• Noncontact tears more common in females
• Why? Several reasons
• Signs & Symptoms
• Loud pop
• Pain, laxity, immediate swelling, and hemoarthrosis (?)
ACL Cont’d• Management:
• Not repairing the ACL can lead to joint degeneration. (examples?)
• Should be repaired with surgery cause if not it leads to knee instability
• Before surgery rehab is usually given to strengthen quadriceps. Why?
• Surgery can be allo- or autoGRAFT
• difference?
Posterior Cruciate Ligament Sprain
• Purpose: To prevent posterior translation of the tibia.
• MOI: Falling directly on a bent knee
• Signs & Symptoms:
• Loud “pop” in back of knee
• pain, swelling, tenderness over posterior knee, laxity
PCL Cont’d
• Management:
• Conservative: Rehabilitation-some positive outcomes have been reported.
• Surgery to repair torn ligament.
Mensicus Tears
• Medial mensicus is MORE commonly injured than lateral mensicus.
• Why? Lat. mensicus is more mobile
• MOI: Twisting force while foot is planted, cutting motion when running, tears that occur overtime due to high stress (i.e. running)
Mensicus Tears Cont’d• Signs & Symptoms:
• Swelling
• Locking, clicking
• Pain when squatting
• Giving way
• Management:
• Conservative if person is not an athlete or tear is in a vascular zone
• Surgery: Indicated for high activity individuals
• Can be repaired or resected depending on case
Joint/Muscle Contusions
• A.K.A. “Charley Horse”
• MOI: Direct blow to the thigh
• Signs & Symptoms:
• swelling and severe pain
• Loss of ROM and strength
• Management:
• Rest, ice, light stretch
• Complete ROM exercises
• Apply pad for protection upon RTP
• Complications: Myositis ossificans
Patellar Dislocations/Subluxations
• MOI: planting leg, slowing down, and cutting suddenly (most common MOI)
• Signs & Symptoms:
• Obvious deformity, severe pain, swelling, complete loss of knee function
Patellar Dislocations/Subluxations Cont’d
• Management:
• Keep athlete still and activate EMS
• Splint and transfer to ER
• Reduce dislocation
• Crutches NWB for 4 weeks +
• Rehabilitation with focus on quad strengthening
Chondromalacia Patella
• Wearing away of articular cartilage on the posterior patella
• MOI: Most common abnormal patellar tracking
• Causes?
• Signs & Symptoms:
• Pain, swelling, crepitus
• Pain with running, walking, stairs, squatting
Osgood-Schlatter Disease
• Pain in patellar tendon where it attaches on the tibial tubercle.
• Occurs in adolescents
• Athlete may experience multiple avulsions and in severe cases COMPLETE avulsion.
• Signs & Symptoms:
• Severe pain when kneeling, running, jumping
• Inflammation
• Enlarged tibial tubercle
• Management: Rest, ice before and after activity, strengthening of quads and hamstrings
Patellar Tendinitis A.K.A. Jumper’s Knee
• Extreme tension/overuse of the quads.
• Places stress on patellar tendon
• Signs & Symptoms:
• Pain and TTP inferior to the patella
• 3 stages of severity
• Management:
• Nsaids
• Rest, Ice, Modalities
• Rehab
• Cross friction massage
• Prentice, William E. Arnheim’s principles of athletic training 12th ed. McGraw-Hill, New York Ny, 2006.