Anatomy and Injuries of the Knee Adapted from

Anatomy and Injuries of the Knee Adapted from Connie Rauser Sabino Sports Medicine

Bones ◦ Femur Medial/lateral femoral condyles articulate w/ tibia ◦ Tibial plateau is flat-articulates w/ femoral condyles ◦ Fibula Articulates w/ tibia ◦ Patella Sesamoid bone protects anterior joint Enclosed in quadriceps/patellar tendon Anatomy-Bones

Joints ◦ Tibiofemoral Hinge joint with synovial lining ◦ diarthrodial ◦ Patellofemoral ◦ Superior Tibiofibular Anatomy-Joints

Meniscus ◦ Medial and lateral ◦ Fibrocartilaginous disks Thicker on outside than inside (poor blood supply) ◦ Lie on top of tibial plateau ◦ Increase stability ◦ Make condyles fit better ◦ Shock absorbers Anatomy-Meniscus

ACL-anterior cruciate ligament ◦ Runs from anterior tibia to posterior femur ◦ Prevents anterior displacement of tibia on fixed femur ◦ Prevents femur from moving posterior during weight bearing ◦ Stabilizes tibia against excessive internal rotation Anatomy-Ligaments

PCL-posterior cruciate ligament ◦ Runs from posterior tibia to anterior femur ◦ Prevents posterior translation of tibia on fixed femur ◦ Prevents femur from moving anterior during weight bearing Both ACL and PCL “cross” or wrap around each other—taut when in extension and looser when in flexion Ligaments

MCL-medial collateral ligament ◦ Attaches on the medial femoral epicondyle & anteromedial tibia ◦ Thickened portion of joint capsule ◦ Two parts-superficial and deep Deep portion attaches to medial meniscus ◦ Stabilizes against valgus stress applied to lateral aspect of joint capsule Ligaments

LCL-lateral collateral ligament ◦ Attaches to lateral femoral epicondyle and head of fibula ◦ Stabilizes against varus stress when force is applied to medial aspect of joint Both the MCL and LCL are tightest during full extension of knee and relaxed during flexion Ligaments

Ligaments

Quadriceps ◦ Rectus femoris, vastus lateralis, vastus medialis, vastus intermedius Knee extension, hip flexion Hamstrings ◦ Biceps femoris, semimembranosus, semitendinosus Knee flexion, hip extension Muscles

Gracilis ◦ Knee flexion, hip adduction Sartorius ◦ Knee flexion, hip external rotation Popliteus ◦ Knee flexion Gastrocnemius ◦ Knee flexion Muscles

Plantaris ◦ Knee flexion Pes anserine ◦ Goose’s foot ◦ Knee flexion, some internal rotation Gracilis, sartorius, semitendinosus Iliotibial Band ◦ Thick band on lateral aspect of thigh Attaches at Gerdy’s tubercle on the lateral aspect of tibia Muscles

Conditioning ◦ Strength, flexibility, cardiovascular and muscular endurance Hamstring strength 60% of quad strength Rehabilitation ◦ Strengthen all muscles around knee joint Shoes ◦ proper type for surface ◦ Length of cleats ◦ Turf vs grass Preventing knee injuries

Preventing knee injuries Knee braces ◦ Functional vs. prophylactic Functional—used to provide support to an unstable knee Usually custom fitted to some degree Uses hinges and supports to control excessive rotational stress and tibial translation Prophylactic-worn on lateral aspect knee to protect MCL. Usefulness questioned—does it cause more injuries?

MOI: ◦ fixed foot and external rotation of femur ◦ knee in valgus position ◦ hyperextension S/S: ◦ “pop”, ◦ knee gives out ◦ instability of knee joint ◦ swelling within knee joint—hemarthrosis ◦ intense pain initially but still able to walk ◦ “+” Lachman’s test ◦ “+” anterior drawer test ACL rupture

MOI

Hyperextension MOI

ACL rupture

The ACL intact The ACL torn Inside the knee joint

Tx: RICE, knee immobilizer, crutches, Physician referral Requires surgical reconstruction ◦ Timing of surgery decided by athlete, parents, doctor ◦ Grafts used are patellar tendon, hamstring tendon, cadaver graft, allograft ◦ 3 -5 weeks in brace, 6 -9 months return to activity ACL Rupture

Knee post-ACL tear Test for Swelling Ballotable Patella Test ACL Rupture

Lachman’s test Stress tests

Modified Lachman’s Stress tests

Anterior Drawer test Stress tests

MOI: ◦ hyperflexion ◦ falling on bent knee with foot plantar flexed ◦ Hit on fixed anterior tibia S/S: ◦ “pop” at the back of knee ◦ Pt. Tender and swelling in popliteal fossa ◦ + posterior sag test, + posterior drawer test PCL Rupture

Tx: ◦ RICE ◦ Immobilization ◦ Crutches ◦ Physician referral ◦ 6 -8 weeks rest/rehab ◦ If surgery is elected, 6 weeks immobilization PCL rupture

PCL rupture

Posterior sag Stress tests

Sunrise or posterior sag Stress tests

MOI: ◦ Blow to the lateral side of knee (valgus stress) ◦ External rotation of tibia MCL Sprain

MOI

2 nd degree? ? MCL sprain

S/S: 1 st degree ◦ Pt. Tender over MCL, stable but pain with valgus stress, mild joint effusion, mild joint stiffness, full ROM 2 nd degree ◦ Partial tearing-superficial portion, Pt. Tender over MCL, some instability with valgus stress but solid endpoint, moderate joint effusion, joint stiffness, limited ROM, unable to fully extend knee joint MCL sprain

S/S: 3 rd degree ◦ Complete tear—superficial and deep portions ◦ Pt. Tender over MCL ◦ Moderate to severe effusion ◦ Severe pain ◦ Loss of motion due to pain, effusion, muscle guarding ◦ “+” valgus stress in 0 and 30 degrees, no endpoint MCL Sprain

Valgus @ 30 stress test @ 0 Valgus stress Stress tests for MCL

Tx: RICE Crutches Knee immobilizer/brace ◦ 1 st degree 1 -2 weeks ◦ 2 nd degree 2 -4 weeks ◦ 3 rd degree 4 -6 weeks Physician greater referral for 2 nd degree or MCL Sprain

The terrible triad or unhappy ◦ Torn ACL ◦ Torn Medial meniscus Complications triad

MOI: ◦ Varus force to medial aspect of knee ◦ internal rotation of tibia S/S: ◦ Pt. Tender over LCL, ◦ pain, ◦ swelling, ◦ loss of motion, ◦ “+” varus stress at 30 degrees—solid endpoint with 1 st degree, less stability but solid endpoint with 2 nd degree, no endpoint with 3 rd degree ◦ if “+” varus stress at 0 degrees flexion suspect ACL or PCL injury as well LCL sprain

Tx: ◦ RICE ◦ Crutches ◦ Knee immobilizer ◦ Physician referral with 2 nd or 3 rd degree LCL sprain

Medial: more often torn than later due to attachment to MCL Lateral: doesn’t attach to joint capsule making it more mobile, less prone to injury MOI: ◦ Weight bearing with rotational force while extending or flexing the knee Meniscus tear

S/S: ◦ Effusion w/in 48 -72 hours ◦ Pt. Tender over joint line ◦ Loss of motion ◦ “locking” ◦ Giving out ◦ Pain with deep knee flexion--squatting Meniscus tear

Types of meniscus tears Meniscus tear

Mc. Murray Test Positive Sign: Pain and/or clicking Meniscus Tears Special Test

Tx: RICE Crutches if necessary Physician referral If knee is “locked” by displaced meniscus, go to ER Arthroscopic surgery to fix Meniscus tears

Dislocation Subluxation Fracture Chondromalacia Patellar tendonitis Injuries to the Patella

MOI: ◦ Foot planted, deceleration, and cutting in opposite direction from the weight bearing foot ◦ Thigh rotates internally while leg rotates externally ◦ Strong forceful contraction of quads (vastus lateralis) Patella Dislocation

S/S: loss of motion/function at the knee Pain Swelling Deformity Pt. Tender over medial aspect of knee joint Dislocation

dislocation

dislocation

Tx: immobilize in position you find it Ice ER visit After reduction, immobilize in extension about 4 weeks—use crutches Strengthen muscles of knee, thigh and hip Dislocation

MOI: same as for the dislocation S/S: ◦ same as for the dislocation except there will be no deformity ◦ Pt. Tender over the medial knee joint ◦ Pain with movement TX: ◦ RICE ◦ Knee Immobilizer and crutches ◦ Physician referral Patella Subluxation

MOI: ◦ direct impact or trauma to patella ◦ Indirect trauma in which a severe pull of the patellar tendon occurs against the femur when the knee if semi-flexed S/S: ◦ hemorrhage which results in significant swelling ◦ pain ◦ Pt. Tender over Patella ◦ extreme pain with weight bearing/movement Patella fracture

Patella Fracture

Another x-ray

Tx: RICE Immobilize Crutches ER Possible fracture surgery depending on type of Patella Fracture

Softening and deterioration of the articular cartilage on the posterior side of the patella Chondromalacia

MOI: ◦ related to abnormal movement of the patella within the femoral groove as the knee flexes and extends ◦ Lateral tracking patella as quads contract usually associated with weak quads (VMO) or in females a wider pelvis Chondro

S/S: ◦ Pain on the anterior aspect of the knee (behind the patella) while walking, running, ascending or descending stairs, sqatting or sitting with knees flexed for a long period of time ◦ Pain with compression of patella in femoral groove Chondro

Tx: ◦ remove from activities that cause the pain ◦ Strenghtening exercises for the quads, especially the VMO ◦ Knee sleeve with patellar support ◦ Ice, heat ◦ Surgery to smooth the posterior side of patella Chondro

Also called “jumper’s knee” MOI: ◦ excessive running, jumping or kicking causing extreme tension of the knee extensor muscle complex S/S: ◦ Pain at the patellar tendon ◦ Pt. Tender over the distal pole of patella ◦ Pain increases with activity ◦ Thickening of tendon ◦ crepitus Patellar tendonitis

TX: ◦ Rest ◦ Ice ◦ Heat ◦ Ultrasound ◦ Cross-friction massage ◦ NSAIDS ◦ Patellar tendon strap/taping ◦ Modify activity Patellar tendonitis

Condition common in adolescent knee MOI: ◦ Repeated pull of patellar tendon at tibial tuberosity apophysis due to excessive running, jumping, kicking, etc. S/S: ◦ pain and Pt. Tender at the patellar tendon attachment on tibial tuberosity ◦ Excessive bony formation over tubersity as tendon continues to pull at the apophysis Osgood-Schlatter’s Disease

S/S: ◦ usually resolves itself when the athlete reaches 18 -19 years of age ◦ Enlarged tibial tuberosity remains Tx: ◦ Modify activity ◦ Ice ◦ Tape/patellar tendon strap ◦ Padding ◦ Strengthening of quads and hamstrings Osgood Schlatter’s

MOI: ◦ Overuse injury that occurs in runners or cyclists attributed to the malalignment and structural asymmetries of the foot and lower leg ◦ Irritation develops over lateral femoral epicondyle or at the band’s insertion at Gerdy’s tubercle on the lateral side of the tibia Iliotibial Band Friction Syndrome

S/S: ◦ Pt. Tender over the lateral femoral epicondyle ◦ Swelling ◦ Increased pain with activity especially distance running and starts and stops and change of direction ITBS

Tx: Stretching the ITB Ice pack/massage Transverse friction massage ITB Modify activity Correct foot/lower leg malalignment ITBS

Can be acute, chronic, or recurrent Numerous bursae involved but most commonly injured are the prepatellar or the deep infrapatellar Bursitis

MOI: ◦ falling directly on knee ◦ Continuous kneeling ◦ Overuse of patellar tendon Bursitis

S/S: ◦ Localized swelling that is similar to a water balloon and is outside the knee joint ◦ Pain especially with pressure Bursitis

Bursitis

Bursitis

Tx: ◦ Rest ◦ Ice ◦ Compression ◦ NSAIDS ◦ Padding for protection when returning to activity Bursitis