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.