Stanbridge - T6 - Ortho2 - W2 - W2 - The Knee

Knee Joint Complex Objectives

• Accurately describe and palpate the bony landmarks and muscular anatomy relative to the knee joint.
• Describe the biomechanics of gross movement and the joint surface arthrokinematics with movement.
• Describe the relationship of muscle imbalance and functional performance of the knee.
• Summarize various causes of knee dysfunction.
• Describe and demonstrate intervention strategies and techniques based on clinical findings and established goals.
• Evaluate intervention effectiveness to determine progress and suggest modifications as needed.

Knee Joint Anatomy

• The hinge joint lacks a deep concave socket, giving it little stability.
• Joint capsule, ligaments, menisci and dynamic restraints provide stability.
• Femur meets the tibia at 170-175°, creating normal genu valgum.
• Genu valgum is less than <170° and is associated with coxa varum
• Genu varum > 180° and is associated with coxa valgum

Osteokinematics

• The knee is often called condyloid versus hinge due to its 2nd degree of freedom for rotation.
• The knee has 2 Degrees of freedom.
• During Flexion and Extension the ranges are +10°-135°.
• During Internal and External Rotation the knee is flexed 40-50° of rotation.
• Review Table 24.1 for Ligaments and Functions.
• Review Tables 24.2 and 24.3 for Menisci and Functions.

Screw Home Mechanism

• The Screw Home Mechanism is a passive motion, and the last 5° of extension,
• During Full Extension, the tibia slightly externally rotated on the femur.
• The popliteus must internally rotate the tibia or externally rotate the femur to "unlock" the knee; Active release.

Patellofemoral Joint

• The patella enhances the torque-producing capability of the quadriceps by 25%.
• The patella has 7 facets: superior, middle, inferior, medial, and lateral sides.
• The "odd" facet is the first part of patella to be affected by premature degeneration of articular cartilage.

Patellar Position

• Standard measure of the patellar tendon length/ greatest diagonal length of patella, to determine Normal, patella Alta and Baja position
• Normal patellar position: PL=PTL
• Patella alta ratio is >1.5
• Patella baja: Ratio is <.74

Quadriceps Muscles

• The quadriceps muscles include the Rectus Femoris, Vastus Intermedius, Vastus Lateralis
• The Vastus Medialis is the 1st quad muscle to atrophy and the last to rehabilitate

Hamstrings

• The hamstring muscles include the Semimembranosus, Semitendinosus, and Biceps Femoris

Gastrocnemius

• The gastrocnemius is a weak flexor of the knee, and plantar flexes of the ankle (talocrural)

Hip Adductors

• Hip adductors are primarily movers of the hip
• The Gracilis is a two-joint muscle that adducts the hip and assists in knee flexion and IR of the lower leg.

Iliotibial Tract

• The iliotibial Tract originates from gluteal muscles and TFL and inserts on Gerdy's tubercle of the tibia.
• With Static standing- primary function, it provides a solid base for glute max to pull on and is an additional lateral support of the knee.
• When Squatting 0-30°- ITB, it is a major lateral supporter of the knee joint.
• When the Knee is in flexion, >30° it is provides a weak knee flexor and external rotation force on the tibia.

Popliteus

• The popliteus performs open chain- Internal rotation of the tibia
• The popliteus performs closed chain- External rotation of the femur

Sartorius

• The sartorius flexes and, internally rotates the tibia providing stability to the medial knee
• Pes Anserinus (goose foot) = Semitendinosus + gracilis + sartorius insertion

Quadriceps (Q) Angle

• Q-angle defined: the degree of angulation present when measuring from the mid-patella to ipsilateral ASIS and to the ipsilateral tibial tubercle
• Line of force determines the pressure distributions on the patella
• Normal Q angle ranges for males is 8-14°, avg 13° (Giles, 2020)
• Normal Q agnle ranges for females is 15-17°, avg 18° (Giles, 2020)
• Females have a greater incidence of patellar dislocation and a higher frequency of PF pain.

Q-Angle

• The Q-Angle can increase due to structural changes or dynamically during movement.
• Increases from external tibial torsion, internal rotation of the femur, dynamic (functional) knee valgus, and a wide pelvis.
• Excessive Q-angle can lead to pathology and abnormal patellar pathology.

Patellar Tracking

• The primary dynamic mechanism for patellar tracking is the quadriceps
• Primary static constraints- medial and lateral retinaculum and contact of the patella on the lateral edge of the patellar groove
• Lateral C-shaped curve with 30-120° of knee flexion
• C-curve creates a medial glide and tilt of the patella
• 0-30° creates a lateral glide and tilt
• Lateral pull occurs from a tight ITB and lateral retinaculum
• Weakness of the hip abductors and ERs creates a dynamic valgus
• VMO action is critical to help counteract the lateral pull as is a good hip abductor control

Patellofemoral Joint Reaction Forces

• Increase due to acuity of Q-angle, angle of knee flexion, location of patella contact, and surface area of contact
• Reduce joint reaction forces by considering exercises in open chain: 90° to 30° of knee flexion, and closed chain- 0-45° of knee flexion

General Intervention Strategies

• Must balance healing damaged structures, improving strength and control of muscles, and increasing efficiency of static restraints.

Acute Phase Goals

• Reduce Pain and Swelling with PRICEMEM
• Regain ROM and decrease loading of affected area with postural corrections and using an assistive device
• Maintain and improve the patient's general fitness. Consider a UBE
• Minimize muscle atrophy with Isometrics, straight leg raises (4 way), PNF, and NMES.
• CKC exercises, decrease shear forces, and emphasize co-contractions.

Subacute Phase Goals

• Attain Full Pain-Free ROM, and restore normal joint arthrokinematics- joint mobilizations (PFJ and tibiofemoral jt.)
• Improve muscle strength and neuromuscular control
• Perform Closed kinetic chain (CKC) exercises like leg press, step ups, deadlifts, squats, etc.
• Open kinetic chain (OKC) exercises such as leg lifts, short arc quads, standing and prone hamstring curls, etc.
• Strengthen proximally and distally- hips and calf

Chronic (Functional) Phase Goals

• Restore strength and neuromuscular control to functional levels and focus on functional training.
• Focus on Plyometrics, sports specific training, and ADL

Knee Joint Common Conditions: Anterior Cruciate Ligament (ACL) Tear

• Intrinsic Factors include narrow intercondylar notch, weak ACL, overall joint laxity, and Lower-extremity mal-alignment
• Extrinsic Factors include altered hamstring and quadriceps strength ratio, altered neuromuscular control of the LE, shoe-to-surface interface, playing surface (dry turf) and the athlete's playing style.
• ACL Injury rates are 2-8x higher in females than men
• Possible etiologies include differences in pelvic width, femoral notch, joint laxity, hormonal influence, ACL size, and muscular strength and activation patterns.
• It can be caused by a combination of sudden deceleration, an abrupt change of direction, a fixed foot, and extreme hyperflexion or extension (less common)
• Special Tests include the anterior drawer test, Lachman tests, and Pivot shift test
• The Unhappy or Terrible Triad involves damage due to valgus force on the ACL, MCL and Medial Meniscus
• ACL tear treatment options (conservative vs surgical) are based on the amount of knee instability, presence of associated injuries (meniscal tears or collateral ligament tears), skeletal maturity of the patient, and expected levels of patient's participation in future sports.
• Conservative management fails in 17.5% of cases

ACL Management

• Conservative vs surgical management can lead to persistent functional limitations, OA of the knee, and reduced quality of life
• At 10-year follow-up, both treatment options show comparable patient outcomes
• The outcomes did not differ between those who chose surgical reconstruction early or late versus those who chose conservative management
• After a 20-year follow-up, there was no difference in knee OA between surgical and conservative approach
• Studies show evidence of spontaneous healing of the ACL after acute injury
• Approx. 1/3 of ruptured ACLs may show evidence of healing when patients are managed conservatively after 3 months of injury.
• Research is needed to determine if a ruptured ACL showing evidence of healing has comparable function to a non-injured ACL
• For those patients who did show spontaneous healing, and who underwent conservative management, there were no significant differences in patient outcomes at 2-year follow up.

Relative Contraindications to ACL Reconstruction

• Relatively inactive individual with no exposure to work, sport, and recreational activities that place high demands on the knee
• Inability to make lifestyle modifications that eliminate high-risk activities
• Inability to cope with episodes of instability
• Advanced arthritis of the knee, and poor likelihood of complying with postoperative restrictions and adhering to a rehabilitation program

ACL Surgical Options

• Autologus grafts- allow for return to proprioceptive response
• Patellar- Uses bone tendon bone
• Hamstring-Uses semitendinosis and gracilis
• Allogenous grafts are biologic tissue taken from another human body, and it carries a risk of disease transmission and rejection (very low)
• Synthetic grafts- are no longer acceptable due to high complication and failure rates.

ACL Intervention

• Tibiofemoral Bracing Sometimes is prescribed after surgery but are controversial due to inadequate protection with custom fit, usually 2x
• After ACL reconstruction brace is used Initially when returning to sport specific training
• Once quad and calf achieve full girth to further stabilize the ACL reconstruction, then the brace is prescribed for support

Knee Joint Common Conditions: ACL Intervention Preoperative phase

• Reduce/ eliminate swelling with modalities and compression
• Restore pain-free ROM
• Restore gait and restore proprioception
• Minimize Atrophy while restoring voluntary muscle contraction
• Provide Patient education

Minimum, Moderate and Maximum Protection Phases After ACL Rupture and Reconstruction should Include

• Pain scale
• Effusion-girth measurements
• Ligament stability-joint arthrometer measurements
• Assess ROM and use of bracing
• Muscle strength and control
• Patellar mobility
• Functional Testing

Therapeutic Goals For ACL Reconstruction by Protection Phase

• Increase Strength Endurance and Power
• Protect healing tissues
• Prevent reflex inhibition of muscle
• Regain CardioPulmonary Endurance
• Transition to maintenance Program
• Achieve Highest Desired Functional level
• Reduce risk of re-injury

ACL Common Interventions by Week

• PRICE (protect, rest, ice, compress, elevate)
• Gait training
• PROM & A-AROM
• Patellar mobilizations
• Multiple angle isometrics
• Stationary Bike with high seat
• Balance and Step up drills
• Light LE Stretching Program
• Introduce closed Chain Exercises such as step ups, and PRe

Criteria to Return to Play after ACL Rupture/Reconstruction

• Symmetrical range of motion without pain
• Isokinetic test parameters
• Isokinetic bilateral comparison (80% or greater)
• Quadriceps bilateral comparison (80% or greater)
• Hamstrings-quadriceps ratio (>66% for males, >75% for females)
• Quadriceps torque-body weight ratio (65% or greater)
• Hamstrings-quadriceps ratio or (>66% for male, >75% females)
• 2000 test within 2.5mm of contralateral leg ,Functional hop test 85% or greater of contralateral side

Posterior Cruciate Ligament (PCL) tear

• Damage usually occurs with significant trauma, such as in a MVA when the knee hits dashboard, when landing with hyperflexed knee from a jump, and when knee is hyperextended with foot planted.

Posterior Cruciate Ligament (PCL) clinical findings

• Will be pain on posterior aspect of the knee joint that may be aggravated with kneeling
• Effusion may also be minimal, and test positive for the posterior sag sign
• Grade I and II heal with conservative treatment including:
• Short period of immobilization and ROM
• Should Strengthen quadriceps
• Avoid positions that increase posterior displacement of the tibia
• Hamstring strengthening is delayed 6-8 weeks

PCL Tear Exercise Type

• OKC exercises have the potential to increase forces on the PCL @ 60-90° range
• CKC exercises 0-45° should be performed to protect the patellofemoral joint and the PCL (squats and lunges)
• Balance and proprioceptive exercises along withPlyometrics have benefit
• Return to sport can occur anywhere between 6-16 weeks

Post Surgical PCL interventions and Rehabilitation include

• Knee immobilized
• WBAT with crutches
• Patellar mobilizations
• PROM and Isometrics of the joint

MCL Sprain Symptoms and injuries

• Caused by a valgus stress or excessive external rotation of the tibia
• Medial meniscus tear is often associated with a severe MCL sprain
• Non-traumatic injuries are usually are from deceleration, cutting, pivoting motions
• Symptoms can include:
• Pain over the ligament and swelling over joint or generalized, with bruising and instability
• Valgus Stress Test

MCL Interventions are based on the grade and level of injury

• Grade I- compression, Ice with elevation and WBAT while Grades two will add a Knee immobilizer or short hinge brace-blocking 20 ext w full flexion- WBAT while Grades III need NWB on affected side- hinged brace and gradual FWB over 4 weeks, or 8-12 depending

Conservative care for the MCL may lead to

• PROM, AAROM, AROM once the knee brace is removed, and strengthening and progression to CKC
• Running is okaying if patient has pain-free, normal gait and can perform Sport-specific exercises with comfortable agility
• Grades I and I-1 2-3 weeks to Return, while Grade III is longer, about - 6+ weeks

Meniscus Tear Common facts

• The Periphery of the Meniscus is thick and tapers into a thin free edge. covers 2/3 of the corresponding articular surface
• Functions and stability such as Load transmission, shock absorption, joint lubrication & nutrition. Secondary mechanical stability with guiding of movement

Types of Meniscus Tears

• Longitudinal tears
• Radial tears
• Oblique flap tears
• Horizontal tears
• and Complex tears

Meniscal Special tests

• Thessaly test
• Apley grind test
• McMURRAY TEST

Meniscus Tear- Surgical Options location is key

• Red zone tears have optimal healing
• These require an repair in the vascular region and 1 cm in length with 50% or instability and arthrosprobing
• Conservative approach will focus on minimizing effusion and restoring pain free ROM

Post Meniscal scope/repair will focus on restoring

• ROM
• Strenght in particular with weight bearing
• CKC not initiated until Week 8

Meniscal box indications to rehab/surgery

• Gradully progres weight bearin and exrcises once client is toleratin. This is imperative in central zone meniscus repairs
• If any clicking is reported during exrcice or after immediatly consult MD
• Gradually increasen knee flesion especially after central zones
• High seat possible to limit the range of the knee when in repair.
• Weight Exercises, and low load weight as posterior translation forces and increased stress must be limited

Healing After surgery

• Dont expect squatting/twisting within 6 months. Same with running
• Do not force squatting in full flesion.

Menuscus Post surgically - rehabilitation

• focus on non impact related injuries
• Avoild Squawting for a longer period.

Surgical approach for the Menuscus will look to

• Proliferative Phase for about a month and a half
• protect restore and enhance quads.
• Focus on quads . Soft tissue flexibility

Articular Cartilage Repair

• Common causes of knee pain and disability with options for patients opt to repair or perform transplantation of
• Osteochodral autograft transfer and stem cell implantation are also possibilities

Tibiofemoral Osteoarthritis

• Tibiofermoral OA is marked at the joint line. and has greater risks in demanding occupation
• A combination of Sports for various reasons. Older age as the bone degrades.
• OA Clinical Presentation will present as follows,
• Pain with weight activities and pain at rest
• With a capsullar range. and greater likelyhood of weakness

Osteoarthritis management:

• ROM
• Strength especiall yquads
• Low impact endurace
• Balance and training activities.
• Thermal NSAIDS, woth shoewerts.

OsteOarthritis Approaches for Tibiofemoral

• Osteomy Axis which allows for the worn portion to move away
• and replaced within the tibia or femur.

Most common Osteoarthritis procedure

• Knee Arthroplasty, long term for elderaly
• three common type of knee joint unconstrainted. semiconatruained, linked with the bone.

Common associated joint Arthroplasty

• Thrombolytic disease, fat embolism
• poor wouund infection and perisethic fractures.

Three phases after Knee AThroplasty

• inflammation control for stimulation of the quads

Patellofemoral Pain (PFP) Syndrome

• Pain is a vicinity of the patella and that is worsen by in certain situations
• Positions that result result in increased or mis directed mechanicxal forces between the platella and femur.

patella and quad tendon pain is common

• Assess Level of injury if it comes in full force.
• check leg allighment
• weak quads.

In general rehab is about

• adwquate warm up
• Gradual return for assessmnets and rehab.

fat pad

• postulated to help gliding. help between chondlse and capsule
• will
• increase pain by swelling and SLK action..
• NSAIDs , heel lift, and other similar treatments

Patella Injuries and Treatment

• compressive action. from direct fall or collision
• Non Displacen rehab cast and removable brace, ROM and strengthening

Gait

• Wa, ( decreased forward momentum, potential injury)

• Knee HYPEREXTENSSION may

• help Knee allignment

• Wa increased stress to knee quadriceps .

• Decreased limb.

• Stance decreased heel first contact

• decreeaased limb, - stability - Varus allignment. Towel hyperextension

, Prone hanng and Isometrics for the Quads, with wall slides and heel slides. With all deep tissue massage involving ITB hamstringS

• All quads

• All should focus on Knee movement. or patella movement.

• tibia on femur / posterior glides and destraction techniques.