Knee Arthroplasty Quiz

Knee Arthroplasty Rehabilitation

• Knee arthroplasty is the surgical construction of a new, artificial, painless, movable, and stable knee joint.
• Indications for surgery include severe joint pain, with or without deformity.
• Common secondary causes of knee arthroplasty include rheumatoid arthritis and osteoarthritis.
• Traumatic arthritis can also be a reason for arthroplasty.
• Contraindications include bone infection, severe osteoporosis, recent joint sepsis, and malignant tumors.

Knee Arthroplasty Classifications

• Uni-compartmental: replacement of the opposing articular surfaces of the femur and tibia of either the medial or lateral compartment; poor results
• Bi-compartmental: replacement of the opposing articular surfaces of the femur and tibia of both the medial and lateral compartments.
• Tri-compartmental: similar to bi-compartmental but also resurfaces the patellofemoral joint.

Preoperative Rehabilitation

• The initial visit records baseline information.
• Measurements include pain, swelling, functional abilities, range of motion (ROM), and muscle strength.
• Patients practice exercises after surgery, like isometric quadriceps contractions.
• Training on crutches or walkers is included in the preparation process.
• CPM (continuous passive motion) machine use is also practiced before surgery.

Early Postoperative Stage

• Deep breathing and coughing helps with pressure sores.
• Ankle pumps every two hours encourage circulation and prevent deep vein thrombosis (DVT).
• Upper extremity exercises are also important.
• Patella movement exercises should be performed.
• Quadriceps sets (10 repetitions) are repeated hourly.
• Avoiding pain and encouraging range of motion helps achieve inner range strength.
• Using a sliding leg lifter to avoid high pressure points could be an option.
• Postoperative day two includes resuming the SLR (straight leg raise) after the first two post-op days.

No CPM Management

• For 4 days, the knee is kept in an extended position using a compression bandage and splint.
• This prevents joint movement and reduces pain.
• Active exercises are not allowed until the immobilization is stopped.
• Assisted weight bearing starts on day two.

Post-Immobilization (After 4 Days)

• Passive mobilization of the patella and surrounding scar tissue reduces pain.
• Active assisted knee flexion begins twice daily for at least 20 minutes.
• Patients are discharged after 5-6 days without any complications.
• Full 50-70° of active knee flexion is expected by day 7.

Knee Flexion Return

• Home-based exercises increase knee flexion by at least 10 degrees daily.
• If 50-70° isn't reached by day 7, CPM is used to maximize flexion for 6 hours daily.
• The knee should reach 80-90° within 14 days.
• Manipulation under anesthesia might be a treatment option if a CPM machine isn't available.
• Water therapy, if available, might also be helpful.

CPM Usage

• CPM machines should be used immediately after surgery (surgical recovery room) up to four days, for 6 hours a day.
• Knee flexion ranges are increased by 10 degrees each day until 80-90 degrees is achieved by day seven.
• Active knee flexion recovery is quicker than in the non-CPM group.
• Walking aids (sturdy splints) can be used two days after surgery for weight bearing.
• Unsupported weight bearing is often delayed by 1-2 days in the CPM group compared to controls, due to quadriceps lag.
• CPM usage is not advised for uncomplicated total knee replacements.

CPM Disadvantages

• Longer time in bed.
• Loss of independence.
• Discomfort.
• Possible incidence of common peroneal nerve palsy.
• Greater quadriceps lag (and possible splints) for patients using CPM machines.

Extensor Lag or Fixed Flexion Deformity

• A particular problem for the CPM group, occurs due to an imbalance between flexion and extension gains.
• Could cause difficulties with lifting the foot.
• Solutions include:
• Passive flexion to stop until extensor lag is reduced.
• Gentle manual mobilization techniques.
• Increasing the extension range.
• Avoiding forceful mobilization.
• Quadriceps exercises focusing on inner ranges.
• Correct stretching of the posterior hamstrings and knees.

Functional Rehabilitation

• Begins in the third week after surgery.
• Closed chain exercises (e.g., sitting to standing from varying heights and step-ups) are integrated.
• Small-arc cycling involves the use of a bicycle.
• Proprioception training: is important to restore the body's awareness of its knee position and movement.

Walking

• Crutches or walkers are used for 6 weeks or more after cemented replacements.
• Crutches or walkers are used for 12 weeks after cementless replacements.
• Walk rhythmically, smoothly, and avoid hurrying.
• Gradually increase the step length and speed.
• Gradually put more weight on the affected leg.
• Use a single crutch or cane on the opposite side.
• Avoid limping and leaning away from the operated knee.

Stairs

• A handrail helps with support.
• Use the 'good' leg to go up and the 'bad' leg to go down the stairs.
• As strength increases, climbing stairs foot-over-foot is possible.

Driving and Other Activities

• Knee joint proprioception, and quadriceps strength and range of motion are necessary for driving.
• Driving should not be attempted until at least 6 weeks after surgery.
• Avoid twisting, turning, jumping, and running for at least 3 months after total knee replacement; some surgeons extend this to 6 months.

Activity Guidelines for Cemented and Cemented-less Prosthesis

• Ranges for flexion and extension are detailed for both types of systems through various weeks after surgery.
• Types of exercises are broken down by type and time. Resisted exercise are introduced later.

Ambulation Guidelines for Cemented and Cemented-less Prosthesis

• Details on when partial, then full weight-bearing becomes acceptable, along with various walking aid requirements.

Problem-Solving Exercises (Example)

• A patient with a 3-day-old knee replacement is in pain, with increased swelling post exercise.
• Possible Causes: infection or DVT (deep vein thrombosis).
• Solution: measure the patient's temperature, check the calf for signs of DVT (swelling, pain, discomfort), and, if necessary, elevate the leg and apply ice.