MK

Knee Injuries and Rehabilitation

The Knee Joint

  • Key components: femur, tibia, patella, ligaments (ACL, PCL, MCL, LCL), menisci, articular cartilage, quadriceps tendon, patellar tendon.

Key Knee Injuries/Conditions

  • ACL rupture
  • Unhappy triad (ACL, MCL, medial meniscus injury, and anterolateral complex)
  • Patellofemoral Pain Syndrome (PFPS)
  • Knee osteoarthritis (OA)

Knee Injuries/Conditions: Symptoms and Risk Factors

  • Symptoms include pain (variable location/severity), swelling, stiffness, redness, warmth, weakness, instability, popping/crunching noises, inability to fully straighten the knee.
  • Risk factors: excess weight, lack of muscle flexibility/strength, certain sports/occupations, previous injury, hormones.

Types of Knee Injuries

  • Ligament injuries (ACL, PCL, collateral)
  • Tendon tears
  • Fractures
  • Meniscus tears
  • Bursitis
  • Tendinitis
  • Mechanical conditions (loose body, iliotibial band syndrome, dislocated patella)
  • Arthritis (RA, OA, gout)
  • Osgood-Schlatter Disease
  • Sudden vs overuse vs chronic injuries

ACL Injuries

  • Rehab: acute phase (PEACE & LOVE), non-surgical rehab, prehab, post-surgery rehab.
  • Prevention: warm-up, appropriate footwear/surface, strength/flexibility, correct technique, avoid excess weight.
  • Epidemiology: More common in females?

ACL Reconstruction

  • Surgical reconstruction aims to restore functional stability and prevent early degeneration.
  • Grafts: autograft vs allograft (bone-patella tendon-bone, hamstring, quadriceps, tibialis anterior/posterior, Achilles, peroneal tendons).
  • Graft selection depends on graft properties and patient characteristics/expectations.

'Unhappy Triad'

  • Injury to ACL, MCL, and medial meniscus (actually a tetrad including the anterolateral complex).

Knee Injury and Osteoarthritis (OA)

  • Knee injury is a risk factor for OA
  • Injured athletes are more prone to OA than the general population.
  • Meniscal injury/meniscectomy is a significant risk factor for OA.

Patellofemoral Pain Syndrome (PFPS)

  • Pain in the front of the knee and around the patella, excluding other conditions.
  • Symptoms: dull pain, increased pain with activity, swelling, grinding feelings, pain after prolonged sitting.
  • Diagnosis: retropatellar or peripatellar pain reproduced with squatting, stair climbing, prolonged sitting, or functional activities.
  • Causes: muscle performance deficits (weak hips/quads), movement coordination impairments, tight ITB/quads/hamstrings, flat feet, training technique, footwear, hypermobility, overuse.

ACL Reconstruction – Surgery vs Non-Op Treatment

  • Average long-term outcomes are similar with rehab alone or ACLR and rehab.
  • Early ACLR may not be better.

ACL Reconstruction – Rehab Strategy

  • Management should aim to restore knee function, address psychological barriers, reduce the risk of further injury/OA, and optimize long-term QOL.
  • Rehab should be individualized and criterion-based, with gradual return to sport/activity.

Knee Injury Prevention Programs

  • Neuromuscular training programs may reduce knee injuries.
  • Include plyometrics, strengthening, flexibility, agility, proprioception/balance, verbal feedback, exercise variations.

ACL Rehab – Key Messages

  • Open chain exercises are safe (isometrics and knee extensions against gravity in 0-90 degrees in the first 4 weeks post-op).
  • Stop using knee bracing and continuous passive motion machines routinely early post-operatively.
  • Use exercise training principles (strength, power, cardiovascular training).

Assessments

  • Knee: ROM, strength (MMT/HHD), PROMs, function.
  • Athletic populations: balance, strength.
  • Older/clinical populations: balance (2-foot, single leg stance), strength (1RM to HHD), physical function/ADLs.

Functional Movement Screen (FMS)

  • Used in athletic populations.

Hop tests:

  • Higher hop for distance scores mean:
    • Up to 2 x higher odds of return to pre-injury sport
    • 50% reduced odds of developing knee osteoarthritis
  • Higher crossover or triple hop scores:
    • 4 x higher odds of better self-reported symptoms & function

Total Knee Replacement

  • Unsupervised/telehealth programs as effective as supervised/in-person.
  • Promising benefits from pedaling exercises, weight training, balance/sensorimotor training.

PFPS Guidelines

  • Interventions consist of Exercise therapy, foot orthoses, patellar taping, patient education, and combined interventions.
  • Don't recommend the use of electrotherapeutic modalities.
  • Exercise interventions: combine hip- and knee-targeted exercises.