Limb prosthetics

Surgical preparation: stump management

The formation of a quality stump begins with the correct handling of bone structures. Sawing is performed using a Gigli wire saw. During the procedure, continuous irrigation of the bone with normal saline is mandatory, which prevents local thermal burns and subsequent tissue necrosis.

The sharp edges of the resulting bone stump are thoroughly smoothed with a rasp. For lower leg interventions, there are anatomical nuances: the anterior border of the tibia is beveled (angled), and the fibula is sawed 2–3 centimeters higher (proximally) than the level of the tibia.

Management of vessels and nerve trunks

In flap amputations, the elements of the neurovascular bundle are isolated in advance.

Rules of hemostasis:

• Vessels must be ligated prior to their transection.
• It is strictly prohibited to suture large arterial trunks en bloc with surrounding muscles. This leads to a high risk of ligature cutout and the development of severe secondary hemorrhage.
• Following the ligation of the main arteries and veins, the surgeons remove the tourniquet and perform final meticulous hemostasis of small branches.

Nerve management: According to N.N. Burdenko, this stage is equivalent to neurosurgical intervention. Gross errors lead to the formation of painful neuromas, nerve retraction into scar tissue, and excruciating phantom pains that often require repeat surgery (reamputation). For correct transection, the soft tissues around the trunk are displaced as far proximally as possible (it is important not to stretch the nerve itself). A novocaine solution is injected into the perineurium, after which the trunk is severed with a single stroke of a sharp razor. As a result, the nerve spontaneously retracts and hides deep within the thickness of healthy soft tissues.

Wound closure and patient management

Surgical tactics for closing the wound defect are dictated by the indications for surgery:

1. Emergency ("guillotine") amputations: sutures are not applied. The wound and bone stump are left gaping to prevent anaerobic infection (gas gangrene). A stump is not formed at this stage; only rare guiding sutures are possible.
2. Elective surgeries: the myoplastic technique is used. The essence of the method lies in suturing the antagonist muscles directly over the bone stump. This significantly improves stump trophics and its functional capabilities. The skin scar is formed away from future weight-bearing zones (on the leg, displaced posteriorly; on the arm, to the dorsal surface). The wound must be drained.

In the postoperative period, to prevent contractures in a faulty position, the extremity is immobilized with a plaster splint. As early as days 5–7, the patient begins rehabilitation—performing isometric contractions of the preserved muscles.

Basics and stages of prosthetics

Prosthetics aims to compensate for lost functions and prevent secondary skeletal deformations. In addition to prostheses proper, which replace a limb segment, orthopedic supporting devices (bandages, corsets, orthoses) and specialized footwear are used.

The decision to initiate prosthetics is based on a comprehensive assessment:

• Local status: quality of the stump, range of motion in adjacent joints.
• Neurovascular status: absence of severe circulatory and innervation disorders.
• General condition: somatic health and the patient's psychological readiness for long-term rehabilitation.

Modern technologies make it possible to create a design for any level of amputation. The process always begins with the use of training prostheses, which are necessary for the initial adaptation of the stump and the readjustment of the body's overall biomechanics.

Classification of prostheses

Depending on the lost segment, the priority tasks of the device change. For the lower limb, weight-bearing capacity (the ability to support body weight when walking) is critically important, whereas for the upper limb, precision of movement, grip volume, and cosmetic appearance come to the forefront.

Types of prostheses by functionality:

• Cosmetic: mask the visual defect.
• Active cosmetic: combine a natural appearance with basic restoration of motility.
• Working (functional): created for the specific occupational or domestic needs of the patient.
• Biocontrolled: high-tech devices with external power sources. Capable of reproducing complex biomechanics, down to the fine motor skills of artificial fingers.

The design of the prosthesis depends on the level of the defect. For example, a hip prosthesis includes a socket, joint-replacing hinges, and a foot. Forearm prostheses may be supplemented with detachable functional hands.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Anatomical and physiological features of fascioplastic amputation
• Pathogenesis and surgical treatment of pathological neuromas
• Principles of operation of externally powered biocontrolled prostheses
• Prevention of muscular contractures in the postoperative period
• Specifics of orthopedic supporting devices and orthoses

Other topics in the section "General Questions of Traumatology and Orthopedics"

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