Technique Spotlight: ORIF vs. Extension Block Pinning vs. Dynamic External Fixation for Proximal Interphalangeal Joint Dislocations

Indications

Extension block pinning may be done when a PIP joint dorsal dislocation or fracture-dislocation can be reduced but is still unstable. It has the benefit of minimizing soft tissue trauma, which reduces the likelihood of stiffness. This technique may also be used to supplement ORIF, depending on the stability of fixation and the joint.

Preoperative Evaluation

A thorough history should be performed, including the date and mechanism of injury. Chronic injuries, defined as injuries >6 weeks old, have worse outcomes when treated surgically including diminished range of motion by 14 degrees, and increased risk of recurrent instability by 43%, when compared with comparable injuries treated within 2 weeks.

As with all hand injuries with suspicion for PIP joint pathology, physical examination should be performed to assess for deformity, skin integrity, swelling, pain, sensation, and range of motion. Occasionally the PIP joint will have gross deformity to it, such as with lateral dislocations, but frequently the joint is simply swollen and painful, with diminished range of motion.

Three plain radiographic views of the finger should be obtained, including a true lateral view, to assess for joint congruency. Subtle joint incongruity may demonstrate the dorsal “V” sign. Computed tomography (CT) scan may be obtained when there is extensive comminution but is not generally needed. Magnetic resonance imaging (MRI) scan is rarely of any utility in the acute setting.

Positioning and Equipment

The patient is often positioned in the supine position on the operative table with an arm board. The procedure can be done with straight local anesthesia, monitored anesthesia care, regional block, or general anesthesia. Local anesthesia is helpful as active motion can be assessed, and the patient can witness intraoperative motion.

Imaging intensification, with mini C-arm fluoroscopy, is used whenever possible as it has lower radiation dose for the patient and staff, can be operated by the surgeon, and often has improved resolution for the small bones of the hand through beam collimation, when compared with standard C-arm fluoroscopy. ^, K-wires of various sizes should be available.