The Knee continued

1
Chapter 6

• The Knee continued

2
Pathologies and Related Special Tests

• Trauma may result from
• Contact-related mechanism
• Rotational forces
• Overuse
• Degenerative changes

3
Uniplanar knee sprains

• Instability in only one plane
• Isolated to a single structure
• MCL/LCL valgus/varus instability in frontal
  plane
• ACL/PCL anterior/posterior shift in sagittal
  plane

4
Medial Collateral Ligament Sprains

• Damaged from
• valgus tensile forces blow to lateral aspect
• Noncontact valgus loading
• Rotational force
• Force dissipated through
• Full extension superficial and deep layers of
  MCL, anteromedial and posteromedial joint
  capsule, tendons of pes anserine
• Flexed beyond 20o superficial layer of MCL

5
MCL Sprains

• Involvement of other structures
• Medial joint capsule and medial meniscus
• ACL
• Distal femoral physis
• Patella
• Evaluative Findings
• Table 6-4, page 218

6
MCL Sprains

• Nonoperative Treatment
• Adequate blood supply
• Functional rehabilitation
• Protection, controlled ROM, strengthening,
  proprioception training
• Knee braces
• Operative Treatment
• High complication rate

7
Lateral Collateral Ligament Sprains

• Damaged from
• Blow to medial aspect of knee
• Internal rotation of tibia on femur
• springy end-feel
• Involvement of other structures
• Lateral capsule
• ACL
• Peroneal nerve

8
LCL Sprains

• Poor healing properties and its importance in
  providing rotational stability to the knee often
  necessitates surgical repair
• Evaluative Findings
• Table 6-5, page 219

9
Anterior Cruciate Ligament Sprains

• Damaged from
• Force causing anterior displacement of tibia on
  femur (or femur driven posteriorly)
• Noncontact-related rotational forces
• Hyperextension of knee
• Unlike other ligaments, most arise from
  noncontact torsional forces

10
ACL Sprains

• Isolated trauma unlikely
• Involvement of other structures
• Other ligaments
• Menisci
• Anteromedial or anterolateral joint capsule
• Per anserine, biceps femoris, IT band

11
ACL Sprains

• Predisposing factors
• Intrinsic vs. extrinsic
• Table 6-6, page 220
• Signs and symptoms
• Hearing and/or sensing a pop
• Loss of function/limited ROM
• Swelling (geniculate artery)
• Intracapsular/extravasate
• Lachmans test/anterior drawer test

12
ACL Sprains

• Evaluative Findings
• Table 6-7, page 221
• Test PCL top rule out false-positive
• partially torn ACL
• Partial trauma leads to dysfunction, instability,
  increased stress on remaining fibers
• Predisposed to future injury
• ACL-deficient knee
• Susceptible to degenerative arthritis

13
ACL Sprains

• Rehabilitation focuses on restoring ROM, lower
  extremity strength, proprioception
• Knee braces
• ACL reconstruction
• To perform activities involving cutting and
  pivoting
• Donor tissue options
• Autografts vs. allografts
• Accelerated rehabilitation programs

14
ACL Injuries in Females

• Experience a disproportionately high rate of
  noncontact ACL injuries relative to males
• Predisposing factors (Table 6-6)
• Narrower intercondyler notch widths
• Phases of the menstrual cycle
• Surging levels of estrogen and progesterone
  increased laxity
• Risk increased 1 week before and 1 week after
  start of cycle, when ACL is most lax

15
Posterior Cruciate Ligament Sprains

• Damaged from
• Tibia being driven posteriorly on femur
• Hyperflexion/hyperextension
• Landing on anterior tibia while knee is flexed
• Figure 6-23, page 222
• Signs/symptoms
• May be asymptomatic at first
• s/s similar to strain of medial head os gastroc
  or posterior capsule

16
PCL Sprains

• Signs and symptoms
• Pain in posterior knee
• Weakness of hamstrings and quadriceps
• Reduced ROM during flexion
• Posterior drawer and sag tests
• Increased instability when other posterior
  structures are also damaged
• Evaluative Findings
• Table 6-8, page 222

17
PCL Sprains

• Predisposing factors
• Joint loading
• Joint congruency
• Muscular activity
• Posterior laxity does not always result in knee
  dysfunction
• Nonoperative treatment
• May lead to chronic instability over time

18
Rotational Knee Instabilities

• Multiplanar involve abnormal internal or
  external rotation at tibiofemoral joint
• Named based on relative direction in which the
  tibia subluxates on the femur
• The axis of tibial rotation is shifted in the
  direction opposite that of the subluxation
• Figure 6-24, page 223
• Table 6-9, page 223

19
Rotational Knee Instabilities

• Result when multiple structures are traumatized
• Combined laxity of each structure is summed to
  mark degree of instability
• Any injury to cruciate or collateral ligaments,
  joint capsule, IT band or biceps femoris may
  potentially result in rotational instability

20
Rotational Knee Instabilities

• Signs and symptoms
• giving out
• Decreased muscle strength
• Diminished performance
• Lack of confidence in stability
• Tests will often only produce positive results
  under anesthesia

21
Anterolateral Rotatory Instability

• Involves trauma to ACL and anterolateral capsule
• LCL, IT band, biceps femoris, lateral meniscus,
  posterolateral capsule
• Anterior tibial displacement and internal tibial
  rotation
• Many special tests to determine ALRI
• Positive results should be referred to physician

22
ALRI

• Slocum drawer test
• ALRI (internal rotation) and AMRI (external
  rotation)
• Box 6-12, page 224
• Crossover Test
• Semifunctional not as exact as other tests
• Primarily for ALRI, but may be used for AMRI
• Box 6-13, page 225

23
ALRI

• Pivot shift test (lateral pivot shift)
• Duplicates anterior subluxation and reduction
  that occurs during functional activities in
  ACL-deficient knees
• Box 6-14, page 226
• Slocum ALRI test
• Body weight used to fixate femur
• Box 6-15, page 227
• Flexion-rotation drawer test (FRD)
• Stabilizes tibia, results in subluxation of femur
• Box 6-16, page 228

24
Anteromedial Rotatory Instability

• Injury involving ACL, MCL, and meniscus (more
  commonly lateral meniscus)
• Variations of Slocum drawer test and crossover
  test

25
Posterolateral Rotatory Instability

• Anterior displacement of lateral femoral condyle
  relative to tibia
• Tibia externally rotates relative to femur
• Amount of external rotation increase with flexion
• Evaluative Findings
• Table 6-10, page 229
• External rotation test for PLRI
• Box 6-17, page 230

26
Meniscal Tears

• Result from rotation and flexion of knee,
  impinging the menisci between the articular
  condyles of tibia and femur
• Lateral meniscus
• More mobility may develop tears secondary to
  repeated stress
• McMurrays test
• Box 6-18, page 231
• Apleys compression and distraction test
• Box 6-19, page 232

27
Meniscal Tears

• Evaluative Findings
• Table 6-11, page 233
• locking, clicking, pain along joint line,
  giving way
• Pain not be described if tear is in avascular
  zone

28
Osteochondral Defects

• OCDs are fractures of the articular cartilage and
  underlying bone that are typically caused by
  compressive and shear forces
• Medial femoral condyle most common also lateral
  femoral condyle, tibial articulating surface,
  patella
• Males affected more than females
• Figure 6-25, page 229

29
OCDs

• Signs and symptoms
• Masked by those of concurrent injury
• Diffuse pain within knee
• locking, giving way, clunking
• Pain increased with weight-bearing activities
• Increase in pain and decrease in strength in
  closed kinetic chain vs. open chain
• Wilsons test Box 6-20, page 234

30
OCDs

• Conservative treatment
• Modified activity
• Surgical repair
• Simple debridement or techniques to stimulate
  fibrocartilage formation
• Newer techniques place newly grown articular
  cartilage within defect, or transplant healthy
  cartilage form one area in knee to defect
• Early protection phase in rehabilitation

31
Iliotibial Band Friction Syndrome

• Friction between IT band and lateral femoral
  condyle
• Occurs in sports that require repeated knee
  flexion and extension
• Running, rowing, cycling
• Bursa between IT band and lateral femoral condyle
  may become inflamed

32
IT Band Syndrome

• Predisposing factors
• Genu varum projects lateral femoral condyle
  laterally, increasing friction
• Pronated feet
• Leg length differences
• Conditions resulting in internal rotation alter
  angle in which IT band attaches to Gerdys
  tubercle, increasing pressure at lateral femoral
  condyle

33
IT Band Syndrome

• Evaluative Findings
• Table 6-12, page 235
• Nobles compression test
• Box 6-21, page 236
• Obers test
• Box 6-22, page 237
• Treatment
• Correct biomechanics, NSAIDs, modalities,
  stretching, strengthening

34
Popliteus Tendinitis

• Evaluative Findings
• Table 6-13, page 238
• Popliteus prevents a posterior shift of tibia on
  femur, running downhill places excessive strain
  on tendon
• Figure-4 position Figure 6-26, page 238
• Treatment similar to other tendinitis conditions

35
On-Field Evaluation of Knee Injuries

• Equipment Considerations
• Football pants
• Knee brace removal
• Figure 6-27, page 239
• On-field History
• Location of pain
• Mechanism of injury
• History of injury
• Associated sounds and sensations
• Associated neurologic symptoms

36
On-Field Evaluation of Knee Injuries

• On-Field Inspection
• Patellar position
• Alignment of tibiofemoral joint
• On-field Palpation
• Extensor mechanism
• MCL and medial joint line
• LCL and lateral joint line
• Fibular head

37
On-Field Evaluation of Knee Injuries

• On-field Range of Motion Tests
• On-field Ligamentous Tests
• Valgus stress, varus stress, Lachmans
• Repeat after removing athlete from sideline

38
On-field Management of Knee Injuries

• Tibiofemoral Joint Dislocations
• Severe pain, muscle spasm, obvious deformity
• Most occur with tibia sliding anteriorly over
  femur, resulting in shortening of involved leg
• Figure 6-28, page 241
• Trauma to neurovascular structures medial
  emergency
• Management immobilization, verifying pulse,
  shock, and activating EMS

39
On-field Management of Knee Injuries

• Collateral and Cruciate Ligament Sprains
• Compare bilaterally if possible
• Remove from field in a non-weight-bearing manner,
  if necessary
• RICE, immobilization, referral, if necessary
• Meniscal Tears
• Evaluation based on athletes description of
  mechanism of injury