Knee & Lower Leg Injuries

Bogdan Irimies PGY-3

June 8, 2006

Knee Anatomy:

Knee Examination

History: ask about current mechanism of injury, prior injuries or surgeries to knee.

Inspect: pt. should be examined while walking, note gait, muscular development, functional ROM. – Inspect the knee for swelling, ecchymosis,

effusion, masses, patella location, erythema, signs of local trauma, note leg lengths, active range of motion.

Knee Examination

Check for neurovascular status Palpate the knee, patella, medial and lateral

joint lines Place the knee in various stress testing

Knee X-Rays

Ottawa Knee rules: determines the need for x-rays, proven sensitive for fracture.– Age > 55– Tenderness head of fibula– Isolated patellar tenderness– Inability to flex knee 90 degrees– Inability to bear weight

Patella Fractures

Result from direct blow such as knee hitting dashboard in MVA, fall on flexed knee, forceful contraction of quad. Muscle.

Transverse fractures most common PE: focal patellar tenderness, swelling,

effusion. – Check for extensor mechanism by doing straight

leg raising against gravity.

Patella Fracture:

Patella Fracture:

Patella Fracture

Tx: non-displaced patella fracture w/intact extensor mechanism is treated w/knee immobilizer, rest, ice , elevation, NSAIDS/Opioids, then long leg cast for 6 weeks.– Fractures that are displaced > 3 mm or assoc.

w/disruption of extensor mechanism requires Ortho. Referral for open reduction & internal fixation

Femoral Condyle Fractures

These injuries secondary to direct trauma from fall w/axial loading or blow to distal femur.

Exam reveals pain, swelling, deformity, rotation, shortening and inability to ambulate

Potential for popliteal artery injury, check for ipsilateral hip dislocations or fractures

Femoral Condyle Fracture:

Femoral Condyle Fractures

Cast immobilization for stable, non- displaced fractures

Open reduction internal fixation for displaced fractures or any degree of joint incongruity

Complications: DVT, fat embolus, delay or malunion, development of OA

Tibial Spine & Tuberosity Fractures

Tibial spine Fx’s:– Anterior tibial spine more commonly fractured– Painful swollen knee, inability to extend fully and

+ Lachman’s sign– If fracture is incomplete or non- displaced, it

should be immobilized in full extension w/knee immobilizer & Ortho outpt. follow-up.

– Complete, displaced fractures require open reduction internal fixation (ORIF)

Tibial Spine Fracture:

Tibial Spine & Tuberosity

Tibial tuberosity: quadriceps mechanism inserts on tibial tubercle– Sudden force to flexed knee w/quadriceps

contraction may avulse tibial tubercle– If avulsion is small or non- displaced just

immobilize.– If displaced, needs ORIF

Tibial Tuberosity Avulsion Fx:

Tibial Plateau Fractures

Produced by varus or valgus forces combined w/axial loading which drives femoral condyles into tibial plateau– Examples: fall from a height or leg struck by car– Painful swelling of knee, limited ROM,

ligamentous instability

Lateral Tibial Platea Fx:

Tibial Plateau Fractures

If one plateau is fractured but non- displaced, Tx w/knee immobilizer, non-weight bearing, outpt. Ortho follow-up for long leg cast

Complications: popliteal artery injury, DVT, OA

Ligamentous & Meniscal Injuries

Functional instability of the knee is determined by stress testing which can demonstrate abnormal laxity.

Medial collateral ligament: valgus or abduction applied to knee to stress test

Lateral collateral ligament: varus or adduction applied to knee to stress test

If there is laxity >1cm w/out firm endpoint then there is complete rupture of MCL/LCL

If there is laxity < 1cm w/a firm endpoint then there is a partial tear

If there is no ligamentous instability but pain w/stress testing, then there is ligament strain

Knee Ligaments:

Anterior Cruciate Ligament

Mechanism is usually a deceleration, hyperextension or internal rotation of tibia on femur

May hear “pop”, swelling, assoc. w/medial meniscal tear

Dx: Lachman’s test, anterior drawer sign , pivot shift– Displacement of > 6 mm is considered positive for

tear.

Posterior Cruciate Ligament

Less common than ACL injury Mechanism is anterior or posterior force

applied to tibia or lower leg DX: Posterior drawer test

Knee Ligaments Dx:

X-rays may be normal or only reveal an effusion

MRI has approximately 90% accuracy in detecting ligamentous or meniscal injuries

Knee Ligaments Tx:

Stable injuries involving only one ligament w/minor strain can be treated w/knee immobilizer, ice packs, elevation, NSAIDS, ambulation that is comfortable for the pt.

If knee is immobilized, have pt. do daily ROM activities to avoid contractures and maintain mobility.

Professional athletes(Kellen Winslow Jr.) w/single ligament rupture or pts. w/more than one ligament ruptured, need Ortho evaluation for surgical repair.

Meniscal Injuries

Mechanism is usually cutting, squatting or twisting maneuvers.

Ask pt. if there is locking of the knee on flexion or extension that is painful or limits there activity.

Exam: joint line tenderness or Positive McMurray’s test(+50% only)

Tx: partial weight bearing, NSAIDS, referral to Ortho as outpt.

Knee Dislocation:

Result of ligamentous disruption, posterior dislocation is most common

With posterior dislocation, ACL & PCL injuries/disruption are common

Assoc injuries include popliteal artery injury, peroneal nerve injury, ligamentous and meniscal injuries

True Ortho Emergency!

Knee Dislocation

Early reduction using longitudinal traction is essential.

Neurovascular status is important to check pre&post-reduction

Ortho C/S & hospitalization required. If signs of popliteal artery injury: absent

pulses, bruits, distal ischemia, C/S Vascular surgeon for possible arteriography.

Knee Dislocation:

Patella Dislocation

Mechanism is a twisting motion on an extended knee.– Patella is usually laterally displaced over lateral

condyle– May have tearing of medial joint capsule– Reduction involves conscious sedation, flexing

the hip, hyperextending the knee, and slide patella back into place

Patella Dislocation:

Patella Dislocation:

Patella Dislocation

Check X-ray to r/o fracture Tx: knee immobilizer, partial weight bearing,

NSAIDS, isometric quad. strengthening exercises and outpt. F/U to Ortho.

Quadriceps/Patellar Tendon Rupture

Mechanism is forceful contraction of quadriceps muscle or falling on a flexed knee.

Significant pain, swelling and inability to extend a fully flexed knee against minimal resistance.

May see a high riding patella on lateral x-ray view of knee

Tx: surgical repair by Ortho

Patella Tendon Rupture:

Osteochondritis Dissecans

Disorder in which a segment of articular cartilage and subchondral bone become separated from underlying bone

Results from acute or chronic trauma Pts. c/o pain, swelling, cannot recall specific

injury Dx: x-rays Tx: protective weight bearing if epiphysis still

open.

Osteonecrosis

Bony infarction caused by disruption of blood flow

Can be primary or secondary– Primary: etiology unknown– Secondary: steroids, SLE, ETOHism, sickle cell,

renal transplant

Osteonecrosis

Pts. Are typically elderly women who present w/acute knee pain

X-rays are usually normal early on, MRI is diagnostic

Tx: protective weight bearing, NSAIDS.– Advanced disease options include: arthroscopic

debridement, curretage,drilling of lesion, bone grafting, tibial osteomy, osteochondral allografts, total knee arthroplasty

Patellar Tendonitis

AKA “Jumpers Knee” b/c seen in runners, basketball players, volleyball players and high jumpers

Pain is in patellar tendon, worse when going from sitting to standing position and running up hills

Tx: Heat, NSAIDS, quadriceps muscle strengthening

Chondromalacia Patellae

Overuse syndrome of patellar cartilage Caused by patello-femoral malalignment

which leads to tracking abnormality of patella putting excessive lateral pressure on articular cartilage

Seen in young active women, pain worse w/stair climbing and rising from a chair

Chondromalacia Patellae

Patellar compression test: push the patella distal in trochlear groove w/knee extended and quadriceps muscle contracted, this will elicit pain.

Tx: rest, NSAIDS, quadriceps strength exercises.

Penetrating Knee Injury/Joint Foreign Body

If knee joint has been penetrated, immediate Ortho C/S for joint irrigation in OR.

Radiopague F.B.(metal, glass) will be seen on X-ray

F.B. in knee joint need to be removed. Tx: IV antibiotics to cover Staph/Strep. For

penetrating wounds or foreign bodies Don’t forget Td prophylaxis!

Fibula Fractures

Most fibula fractures are result of tibia fractures.

Treatment is determined by injury to tibia Fibula only bears 15% of body weight so pts.

may ambulate. Isolated fibula fracture treated w/either knee

immobilization or elastic wrap.

Fibula Fracture:

Tibia Fractures

Mechanism usually involve torsional force, bending force or direct blow.

Closed, minimally displaced fractures can be treated w/reduction and immobilization

If fracture is displaced, ortho. C/S for further reduction

Watch for compartment syndrome Open fracture: immediate Ortho C/S, immobilize

fracture, sterile coverage of the wound, Td update, IV antibiotics(1st gen. Ceph.), to OR for irrigation & debridement.

Tibia Fracture:

Achilles Tendon Rupture

Mechanism is forceful plantar flexion. Pt. may hear popping sound, difficulty

ambulating Risk factors: quinolone use, RA, SLE, steroid

use Dx: palpable gap in tendon, + Thompson test,

inability to walk on toes Tx: splint in neutral position, refer to Ortho and

don’t forget the crutches.

Shin Splints

Refers to pain over medial or anterior tibia that occurs w/exertion & relieved w/rest

Caused by micro tears of muscular fibers at the point of bony attachment

Tenderness on exam over anterior tibia X-rays may reveal stress fracture, bone scan

is most sensitive Tx: stop offending activity, orthotics, strength

and flexibilty exercises

Osgood Schlatter Disease

Seen in athletic teenagers Lesion is partial separation of tibial tuberosity

at insertion of patellar tendon Palpation of tibial tuberosity reveals

tenderness & induration X-ray lateral may reveal elevation of tibial

tubercle off of tibia Tx: stop offending activities, cold compresses,

NSAIDS, Ortho referral

Do you need an xray?

Questions:

1. T or F: An ACL tear is commonly assoc. w/medial meniscal tear as well.

2. T or F: When you prescribe a knee immobilizer, you must instruct pt. to do daily ROM exercises.

3. T or F: Posterior knee dislocation is assoc. w/possible popliteal artery injury.

4. T or F: For open fractures, Tx includes, Td prophylaxis. Sterile dressing, IV ATBX, irrigation and debridement in OR.

5. T or F: RA, SLE, steroid injections, quinolone ATBX are all risk factors for achilles tendon rupture.

Answers : ALL T!