Name of the Procedure:

Addition, endoskeletal knee/shin system, 4-bar linkage or multiaxial, pneumatic swing phase control (L5840)
Common name(s): Pneumatic knee system, 4-bar pneumatic knee

Summary

A knee prosthetic enhancement that combines a 4-bar linkage or multiaxial support with pneumatic swing phase control to aid individuals with above-knee amputations in achieving smoother and more natural gait mechanics.

Purpose

This procedure aims to improve mobility and the quality of life for individuals with above-knee amputations by providing a more stable and controlled knee joint. The expected outcomes include enhanced walking efficiency, better shock absorption, and minimized risk of falls.

Indications

• Above-knee amputation
• Difficulty in achieving a stable gait with a manual knee prosthesis
• Conditions requiring enhanced knee stability and control, such as weak hip musculature or balance issues

Preparation

• Pre-procedure evaluation by a prosthetist or orthopedic specialist
• Assessment of the patient’s overall health and mobility status
• Adjustment or discontinuation of medications may be recommended
• Measurements and molds taken of the residual limb to ensure proper prosthetic fitting

Procedure Description

1. Consultation and Preparation: The patient meets with their prosthetist to discuss the new knee system and undergo necessary pre-fitting assessments.
2. Prosthetic Fitting and Adjustment: The endoskeletal knee/shin system is customized based on the patient’s limb measurements and individual needs.
3. Installation: The prosthetist installs the pneumatic knee system onto the patient’s existing prosthetic limb or fits it into a newly crafted prosthesis.
4. Alignment and Tuning: The prosthetist aligns the prosthetic limb and adjusts the pneumatic swing phase control settings for optimal performance.
5. Testing and Training: The patient tests the new system under supervision, and adjustments are made as necessary. The patient receives training on how to walk and perform daily activities with the new prosthetic knee.

Tools, equipment, or technology used: Prosthetic fitting tools, molds, pneumatic knee systems

Anesthesia or sedation details: Not applicable

Duration

The fitting and adjustment process can take several hours, usually completed within one or two appointments.

Setting

Orthopedic or prosthetic clinic

Personnel

• Certified Prosthetist
• Orthopedic specialist (if needed)
• Rehabilitation specialist (for training)

Risks and Complications

• Discomfort or improper fit, requiring adjustments
• Rare cases of mechanical failure or malfunctions in the pneumatic system
• Skin irritation or pressure sores at the interface
• Adjustment period required for walking stability

Benefits

• Improved walking efficiency and smoother gait
• Enhanced shock absorption
• Increased stability and decreased risk of falls
• Greater comfort during daily activities

Recovery

• Initial adaptation period where the patient may need physical therapy
• Instructions for care and maintenance of the prosthetic limb
• Regular follow-up appointments to ensure optimum functioning and fit

Expected recovery time: Varies, but patients generally adapt within a few weeks

Alternatives

• Manual knee prostheses: Less technologically advanced, may offer less stability
• Hydraulic knee systems: Provide fluid motion but can be heavier and more costly

Pros and cons of alternatives:

• Manual knee prostheses are simpler and less costly but may not offer the same level of control.
• Hydraulic systems provide smooth motion but can be heavier and may require more maintenance.

Patient Experience

During the fitting procedure, the patient remains awake and participative, giving feedback on comfort and fit. Some initial discomfort and awkwardness may occur as the patient adjusts to the new system. Pain is generally minimal and can be managed with over-the-counter pain relief if necessary. The patient may feel a significant improvement in mobility and stability post-procedure.