PTA 130 - Fundamentals of Treatment
The Knee
Lesson Objectives
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Identify key anatomical muscles and structures of the knee
Identify common tissue injuries, conditions and surgical interventions
Analyze restorative interventions for common injuries, conditions, and surgical procedures
Identify soft tissue specific mobilizations
Identify flexibility, strengthening, functional, and stabilization exercises
Knee Structure
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Joints:
o Tibiofemoral
o Patellofemoral (PF)
Capsule
Ligaments:
o Medial collateral (MCL)
o Lateral collateral (LCL)
o Anterior cruciate (ACL)
o Posterior cruciate (PCL)
Muscles:
o Quadriceps
o Hamstring group
o Gastrocnemius
o Popliteus
Knee Structure
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Primary stability comes from the ligaments
Secondary stability from the joint capsule & surrounding muscles
The knee joint capsule encloses the tibiofemorial joint and the patellofemoral joint
A biaxial, modified hinge joint
Arthrokinematics
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Depends upon open-chain or closed-chain activities
Tibial Motion- Open-chain
o Flexion – Posterior slide
o Extension – Anterior slide
Femoral Motion – Closed-chain
o Flexion – Anterior slide
o Extension – Posterior slide
“Screw -Home” Mechanism
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The rotation that occurs between the femoral condyles and the tibia during the final degrees
of extension
The femur rotates internally during closed-chain activities (the tibia is fixed)
As the knee is unlocked, the femur externally rotates
Acts as a stabilizing function of the knee joint
Referred Pain and Nerve Injuries
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Sciatic nerve divides into the tibial and common peroneal nerves just proximal to the
popliteal fossa
L3 nerve root refers to the anterior aspect of the knee
S1 and S2 refer to the posterior aspect of the knee
The hip joint may refer symptoms to the anterior thigh and knee
Nerve Injuries Around the Knee
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Common Peroneal Nerve (L2-4)
o Becomes superficial where it winds around the fibula just below the fibular head, a
common site for injury
o Symptoms of sensory loss and muscle weakness are distal to that site
Saphenous Nerve (L2-4)
o Innervates the skin along the medial side of the knee and leg
o May be injured with trauma or surgery in that region
Joint Hypomobility & Common Impairments
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Degenerative Joint Disease
Rheumatoid Arthritis
Postimmobilization Hypomobility
Capsule, muscle and soft tissue restrictions
Adhesions may restrict gliding of the patella further limiting knee mobility
Motion loss usually flexion > extension
Pain during AROM and weight bearing, disturbed balance, sit to stand, stair climbing,
squatting
Joint Hypomobility Management
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Protection Phase
o Control pain
o ROM techniques
o Setting exercises
o Patient education- splinting, bracing, exercise to maintain mobility
o AD to relieve pain and stress on the joint
o Minimize stair climbing, elevated toilet seats, avoid deep chairs or sofas
Joint Hypomobility Management
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Controlled Motion & Return to Function Phase
o Continue patient education
o Gentle joint mobilization
o Patellar glides
o Stretching techniques
o Progressive strengthening
o Muscular endurance
o Functional training
o Improve cardiopulmonary endurance
Joint Surgery and Postoperative Management
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Repair of Articular Cartilage
Synovectomy
Total Knee Arthroplasty
Lateral Retinacular Release
Anterior Cruciate Ligament Reconstruction
Posterior Cruciate Ligament Reconstruction
Meniscus Repair
Partial Menisectomy
Repair of Articular Cartilage Defects
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Injuries of the ligaments or menisci of the knee and acute or chronic patellofemoral
dysfunction often are associated with damage to an articular surface of the knee
Surgical interventions are challenging because of the limited capacity of articular cartilage to
heal
Indication for surgery is a symptomatic knee, typically over weight-bearing portions of the
medial or lateral femoral condyles, the trochlear groove, and the articulating facets of the
patella
Repair of Articular Cartilage Defects
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Microfracture
Osteochondral Autograft Transplantation
Osteochondral Allograft Transplantation
Autologous Chondrocyte Implantation
Microfracture
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Indicated for repair of small defects
Performed arthroscopically
Surgeon uses an awl (spike) to penetrate the subchondral bone and expose the bone marrow
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Stimulates a marrow-based repair response leading to local ingrowth of cartilagenous repair
tissue to repair the lesion
Osteochondral Autograft Transplantation
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Indicated for focal lesions involving chondral or subchondral tissue of the weight-bearing
surfaces of the knee
Arthroscopic procedure involving the transplantation of small areas of intact articular
cartilage into the site of the chondral defect
Bone-to-bone graft
Osteochondral Allograft Transplantation
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Typically used for defects larger than 4 cm
Intact articular cartilage is taken from a cadaveric donor
Only fresh, intact grafts can be used for this procedure
Autologuous Chondrocyte Implantation
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Used for full-thickness chondral and osteochondral defects of the femoral condyles or patella and
occurs over two stages
Stage One:
o Healthy articular cartilage is harvested from the patient, chondrocytes are extracted,
cultured for several weeks, and processed in a laboratory
Stage Two:
o Implantation phase
o Chondral defects are debrided, covered with a periosteal patch, chondrocytes are injected
under the patch
Common Cause of Articular Cartilage Defects
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Chondromalacia
o Softening of the articular cartilage of the patella
o Occurs most often in young adults
o Can be caused by injury, overuse, misalignment of the patella, or muscle weakness
o Instead of gliding smoothly across the lower end of the thigh bone, the kneecap rubs
against it, thereby roughening the cartilage underneath the kneecap
Common Cause of Articular Cartilage Defects
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Chondromalacia
o The damage may range from a slightly abnormal surface of the cartilage to a surface that
has been worn away to the bone
o Trauma -a blow to the kneecap tears off either a small piece of cartilage or a large
fragment containing a piece of bone (osteochondral fracture)
o Treatment: low-impact exercises that strengthen muscles without injuring joints,
swimming (aquatic therapy), taping techniques, bio-feedback
Synovectomy
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Synovectomy is an operation performed to remove partial or all the synovial membrane of a joint
May be an arthroscopic procedure or an open procedure
Indications for synovectomy of the knee:
o Chronic, proliferative synovitis, joint pain, restricted joint mobility
o Synovial hypertrophy and joint pain
Synovectomy
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Postoperative Management – Maximum Protection Phase
o Knee is immobilized for 24-48 hours
o Ambulation with crutches
o Pain and edema control
o Regaining full, active knee extension is essential
o Knee ROM activities (patient will typically regain full ROM within 10-14 days
Postoperative Management – Moderate, Minimum Protection and Return to Function
o Activities to regain functional control of the operated knee
o Full weight-bearing
o Cardiopulmonary fitness
o Balance activities
o CKC strengthening
o Gait training
o Proprioceptive training
Total Knee Replacement/Arthroplasty (TKA)
Typically performed for advanced arthritis of the knee
Knee Arthroplasty
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Initial goal is to gain ROM
o Hospital discharge criteria is usually 90 degrees of knee flexion
Initiate activation of the quadriceps early
QUADS, QUADS, QUADS! –
o Knee extension needs to be complete – goniometric measurement 0 degrees
TKA – Postoperative Management
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Immobilization and Early Motion
o Possible use of a CPM in the hospital
o Muscle setting exercises
o MD will determine weight bearing status for each patient depending upon the type of
implant used
o Ambulation with assistive device
o Pain and edema control
o Gentle patellar mobilization
TKA – Postoperative Management
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Maximum Protection Phase
o Progression to FWB
o Continued ROM and stretching activities
o Strengthening exercises – knee and hip
o Patellar mobilization
o Gait training
o Proprioceptive training
Minimum Protection and Return to Function Phases
o 8-12 weeks and beyond
o Emphasize task-specific strengthening exercises
o Proprioceptive training
o Cardiopulmonary conditioning
o Recommendations for Participation in Physical Activities Following TKA (pg. 709, Box
21.5)
Continuous Passive Motion (CPM)
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Early motion encouraged
Following surgery a continuous passive motion (CPM) machine may be administered for the
patient at home
Post-operative Exercise
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Quad Sets
Ankle Pumps
Heel Slides
Straight Leg Raise
Lateral Retinacular Release
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Designed to reduce an identified lateral tilt of the patella and/or alleviate excessive compressive
forces on the lateral facet of the patella
Indications for surgery –
o Chronic patellofemoral pain & functional limitations without improvement after 6
months of conservative treatment (taping, exercise, bracing, meds, modification of daily
activities)
Lateral Retinacular Release
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Maximum Protection Phase (1-2 wks) –
o Control swelling & pain, ROM, patellar mobility, muscle control, ambulation w/o AD,
HEP
Moderate Protection Phase (3-4 wks) –
o ROM, control edema, strengthening, ADLs, HEP
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Minimum Protection Phase (5-6 wks) –
o 70% strength, patient education & monitoring for slow return to activity
Return to Function Phase (>6 wks) –
o Develop maintenance program & monitor for patient compliance
Ligament Injuries
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Ligaments provide the key stabilizing forces for accessory motions (anterior/posterior
translation, medial/lateral pivots) of the knee
Acute traumatic disruption or chronic laxity of the ligaments results in excessive accessory
motions of the joint
The ACL is the most frequently injured and surgically repaired
Ligament Injuries
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Anterior Cruciate Ligament (ACL) is most often injured by a lateral blow to the knee or
twisting the knee on a planted foot
Posterior Cruciate Ligament (PCL) is most often injured by a direct impact, such as in a
dashboard injury (MVA) or falling on a flexed knee
“Terrible Triad”- ACL, MCL and medial meniscus injured at the same time
Medial Collateral Ligament (MCL) injuries occur from a valgus force across the medial joint
line
Lateral Collateral Ligament (LCL) injuries occur infrequently and usually from a traumatic
varus force
Common Impairments
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Delayed swelling unless blood vessels are torn
Complete tear - instability noted on special tests
With swelling, the knee assumes position of minimal stress, flexed to 25 degrees and
inhibition of the quadriceps occurs
Difficulty bearing weight for ambulation
Knee may collapse during weight bearing activities
Non-Operative Management
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Rest, Joint Protection, Exercise
Maximum Protection Phase
o PRICE
o Use of an assistive device
o Educate patient on safe transfers to avoid pivoting on affected leg
o Initiate Quad sets
Moderate Protection through Return to Activity
o Improve muscle performance, function, CV condition
Ligament Surgery
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Intra-articular vs. extra-articular
o Intra-articular is used primarily for ACL and PCL
Open, arthroscopic, or endoscopic
Indications:
o Disabling instability
o Frequent knee buckling
o Positive pivot-shift test
o High risk of re-injury
ACL Post Operative Management
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To brace or not to brace?
o Depends upon the surgeon, approach, and graft
Generally weight bearing is allowed soon after surgery
Maximum Protection Phase- ACL
o Delicate balance between adequate protection of the graft and prevention of adhesions,
contractures, etc.
ACL Post Operative Management
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Achieve 90 deg flexion and full passive extension by the end of the first week
Moderate Protection Phase
o Achieve full ROM
o Increase strength, endurance and balance
o Ambulate w/o AD
o Improve neuromuscular control, proprioception
Minimum protection to Return to activity phase
o Begins 10-12 weeks postoperatively
PCL Reconstruction
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Injury of the PCL is relatively infrequent
Usually accompanied by damage to other structures of the knee
Indications for surgery:
o Complete tear or avulsion of the PCL
o Chronic PCL insufficiency
o Isolated, symptomatic, grade III PCL tear with instability of the knee
PCL Post Operative Management
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Generally braced in full extension
Weight bearing progressed gradually
Avoid exercises that create posterior shear of the tibia on the femur
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Maximum Protection Phase
o Control acute symptoms
o Prevent DVT’s
o Re-establish control of the quads
o Maintain patellar mobility
o Regain 90 deg flexion by 2 to 4 weeks
o Begin to reestablish proprioception, neuromuscular control and balance
PCL Post Operative Management
Moderate to Minimum protection phase
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Achieve full ROM by 9-12 weeks post-op
Continue precautions to avoid excessive posterior shear forces
Advanced neuromuscular training with plyometrics, balance and agility drills
Progress aerobic conditioning
Activity specific training
Full return to sport may take up to 9 months
Meniscus
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Outer - lateral meniscus
o Circular shaped , smaller ,more mobile
o Attached to the ACL
o Attached to the femur via the ligament of Wrisberg
Inner - medial meniscus
o “C” shaped
o Wider posterior than lateral
o Attached to the MCL
o Attached to the joint capsule
Meniscal Injuries
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A partial or total tear may occur when a person quickly twists or rotates the upper leg while the
foot is planted
o The medial meniscus is injured more frequently than the lateral meniscus
o Mechanism of injury to the medical meniscus usually occurs with the foot fixed and
femur rotates internally
 Pivoting, getting out of a car, or a clipping injury
o Mechanism of injury to the lateral meniscus usually occurs with external rotation of the
femur on a fixed tibia
Meniscal Non-Operative Injuries
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Meniscal tears may cause acute locking of the knee or chronic intermittent locking
Tears of the outer border with a rich vascular supply heal well; central tears usually do not heal
and usually require surgery
The age and activity of the patient determine if surgery should be performed
Exercises:
o Open and closed chain to improve strength and endurance along with functional activities
Post-operative Meniscal Management
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Primary surgical options are partial menisectomy and meniscal repair
Variables that determine exercise and weight bearing progression
o Location and nature of the tear
o Single tear vs complex
o Knee alignment
Bracing and weight bearing determined by procedure
Post-operative Meniscal Management
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Maximum Protection Phase
o Begin post-op day 1
o Control pain, joint effusion and vascular complications
o Regain functional ROM
o Prevent patellar restrictions
o Re-establish control of knee musculature
o Improve strength and flexibility of the hip and ankle musculature
o Maintain cardiopulmonary fitness
Moderate Protection Phase
o AD to provide some degree of protection with ambulation
o Restore full knee ROM
o Improve LE flexibility, strength, muscular endurance
o Neuromuscular control and balance
Minimum Protection Phase
o Return to high level activity if adequate strength has been restored
o Full, non-painful ROM
Tendon Injuries
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Tendinitis
o Inflammation of a tendon
o Overuse of a tendon (such as with dancing, cycling or running) causes the tendon to
stretch and become inflamed.
o Patellar tendinitis often results in:
 Tenderness over the tendon
 Inflammation
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Ruptured tendon
o A complete rupture of the quadriceps or patellar tendon is not only painful, but also
makes it difficult for a person to perform functional activities
PATELLOFEMORAL DYSFUNCTION
PF Compressive Forces
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No compression in full knee extension
Patellofemoral compressive forces increase between 30°-90° of knee flexion
Closed kinetic chain (CKC): 0° to 30° produces minimal PF stress
Open kinetic chain (OKC): <20° (without weights) produces minimal PF stress
Patellar Malalignment
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Patella Alta:
o Patella is higher than its normal position in the patellofemoral groove
Patella Baja:
o Patella is lower than its normal position in the patellofemoral groove
Q- Angle
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The angle formed by the intersection of a line drawn from the center of the patella to the
ASIS and a line drawn from the center of the patella to the tibial tuberosity
Subtract the above angle from 180 degrees
Increased Q-angle may lead to increased pressure of the lateral facet against the lateral
femoral condyle when the knee flexes during weight bearing activities
Patellofemoral Dysfunction Treatment
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Patient education– identify and correct causative factors
o Minimize stair climbing
o Avoid prolonged sitting with knee flexed
Evaluate patellar alignment & tracking in WB and NWB
Exercise & HEP Instruction
o Increase flexibility of restricted tissue (ITB, Gastrocsoleus, Hamstrings)
o Correct muscle imbalances
 Latest research emphasizes lateral hip muscular strengthening to improve
alignment
Patellar mobilization
STM – cross friction massage
Taping - McConnell taping or K-taping
OTHER COMMON KNEE DISORDERS
Osgood-Schlatter Disease
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A condition caused by repetitive stress or tension on part of the growth area of the upper tibia
Inflammation of the patellar tendon and surrounding soft tissues at the point where the tendon
attaches to the tibia
Most commonly affects active boys, ages 10-15, who play games or sports that include frequent
running and jumping.
Presents as a bony bump that is particularly painful when pressed - may appear on the upper edge
of the tibia (below the kneecap)
Typically, motion of the knee is not affected
Treatment:
o ROM/Stretch, Stabilization/Isometric, modalities
Iliotibial Band Syndrome
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An inflammatory condition caused when the IT Band rubs over the outer bone (lateral condyle) of
the knee
Although iliotibial band syndrome may be caused by direct injury to the knee, it is most often
caused by the stress of long-term overuse, such as sometimes occurs in sports training and,
particularly, in running and cycling
Treatment :
o Stretching/ROM, modalities, STM
Osteochondritis Dissecans
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Results from a loss of the blood supply to an area of bone underneath a joint surface
o i.e. retro surface of the patella
The affected bone and its covering of cartilage gradually loosen and cause pain
Usually arises spontaneously in an active adolescent or young adult
o May eventually develop osteoarthritis
o Treatment:
 Stretching ROM and low-impact exercises that strengthen muscles without
injuring joints, swimming/aquatic therapy, modalities
Common Exercises for the knee
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Prolonged Extension Stretch in Long Sitting
Wall Slides
Anterior Thigh Stretch
Knee Strengthening Exercise
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SAQ’s
SLR’s
Wall Sits/Squats
Fitter
“Monster Walks”
Lunges
Repeated Step Ups/Step Downs
Balance activities