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DORSAL APPROACH TO THE BASAL JOINT OF THE THUMB

USES

This approach is used to address dorsal or dorsoradial pathology of the basal joint of the thumb. It is most commonly used for procedures addressing basal joint arthritis, such as carpometacarpal arthroplasty or ligament reconstruction with interpositional arthroplasty.

ADVANTAGES

The approach provides direct access to the trapeziometacarpal joint. The skin incision can be fashioned to curve proximally and volarly to gain access to the flexor carpi radialis tendon.

DISADVANTAGES

Branches of the superficial radial nerve are retracted in this approach and are susceptible to neuropraxia and/or hypersensitivity.

STRUCTURES AT RISK

Structures at risk include branches of the superficial radial nerve, located in the subcutaneous plane of dissection, and the abductor pollicis longus and extensor pollicis brevis (EPB) tendons, located immediately below the subcutaneous tissue layer. Proximally lies the dorsal branch of the radial artery. Also, when performing a trapeziectomy or a hemitrapeziectomy, the flexor carpi radialis tendon can be injured, where it lies in a volar groove in the trapezium.

TECHNIQUE

Any of several skin incisions can be used. The most common are transverse, T-shaped, or bayonet incisions. Place the incision so that the transverse limb is centered over the trapeziometacarpal joint. Use the knife only to divide skin, then use longitudinal blunt dissection to spread down to the first compartment tendons. Branches of the superficial radial nerve lie in the subcutaneous fat layer and should be carefully protected. The interval between the abductor pollicis longus and extensor pollicis brevis is used to gain access to the dorsal capsule. Flex and extend the thumb and first metacarpal to help identify the carpometacarpal joint. Sharply divide the capsule and elevate the adherent soft tissue envelope from the trapezium and base of the first metacarpal, exposing the trapeziometacarpal joint.

TRICKS

Longitudinal traction along the axis of the thumb both helps to open up the joint space and provides stability to the thumb during the dissection.

HOW TO TELL IF YOU ARE LOST

Related posts:

Volar Approach to the Basal Joint of the Thumb (for Bennett’s Fracture) Paronychium Approach Anterior Approach Deltopectoral Approach Posterior Approach Anterior Approach to the Cervical Spine

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