36 Proximal Interphalangeal Joint Fracture-Dislocation
Proximal interphalangeal joint injuries represent one of the more difficult problems in hand surgery. Fracture dislocations of the joint generally are complex problems involving intraarticular bony pathology in addition to surrounding soft tissue damage. A multitude of operative techniques, ranging from fracture fixation to partial arthroplasty grafts are available depending on the context and surgeon preference.
Proximal interphalangeal joint (PIPJ) fracture-dislocation is one of the most difficult phalangeal injury patterns to manage. An array of options ranging in complexity are available. Simpler options include dorsal-block extension pinning and dynamic external fixation that can be performed closed. More invasive options include open reduction, internal fixation, volar plate arthroplasty, and hemi-hamate arthroplasty. Assessment of the involved joint surface and fracture pattern aid in treatment selection.
36.2 Key Principles
PIPJ fracture-dislocation involves damage to both the intraarticular aspect of the joint and the surrounding joint soft tissue structures (e.g., collateral ligaments, volar plate). The extent of injury varies and is generally best assessed by the amount of articular involvement and the pattern of fracture. The PIPJ is particularly predisposed to stiffness and, unfortunately, occurs in a functionally important area that accounts for the largest single-joint contribution to finger arc of motion. Injuries generally affect the grasping of objects. Management priorities include eliminating subluxation and early mobilization.
Outcomes vary by extent of injury, time to presentation, and technique. Active range of motion (ROM) of around 90 degrees is possible for most injuries with appropriate treatment. Patients may underestimate the functional implications present as well as the considerable hand therapy rehabilitation involved to maximize motion. Patients will generally need to dedicate considerable time toward range-of-motion exercises over a 3-month period.
Stability of fracture-dislocation depends on the amount of articular involvement and range of motion on examination. Stable injury patterns generally are less than 30% of the articular surface and unstable patterns are more than 50%. Between those values, examination and patient factors can help direct treatment. Fracture types can be simple or comminuted. Fractures that require greater than 30 degrees of flexion to reduce are considered unstable.
Stable injuries amenable to progressive extension block splinting
Lesser intra-articular involvement (less than 30%) and ability to maintain reduction with 30 degrees or less of flexion
Inability to engage hand therapy
Low functional demands
Concomitant severe injuries
Dorsal lip fractures with less than 2-mm displacement
36.6 Special Considerations
Physical examination should include an assessment of PIPJ arc of motion and varus/valgus stability. Stability of volar lip fractures is confirmed clinically by maintained reduction in full extension and absent subluxation on lateral radiograph. Plain radiographs can underestimate the fracture component, particularly in the volar lip, and CT scans can add diagnostic information.
36.7 Special Instructions, Positioning, and Anesthesia
Can be performed under general anesthesia, regional block, or a digital block
Supine with hand outstretched on a hand table
A tourniquet can be applied to the upper arm or digit
Mini C-arm fluoroscopy available for intraoperative use
Kirschner (K-wires) (0.028–0.045 size)
Dynamic external fixation
o Extended (9-inch) K-wires
o Dental rubber bands
Hand screw set (1.0, 1.3-mm screws and 0.7- to 2-mm drill), depth gauge, screw driver
Small osteotome, sagittal saw (0.4- to 1-cm blades), hand screw set
36.8 Tips, Pearls, and Lessons Learned
The goals of restoration of the articular surface and early motion are important. With multiple approaches, there is no single best solution. The simplest operation that restores the joint surface and will allow ROM up to 90 degrees should be pursued. Simpler injuries can be adequately addressed by extensionblock splinting alone and should be strongly considered, particularly for older patients (age 60 and older) with lesser complaints.
For open approaches, broad exposure is important. Be prepared to perform a wide shotgun approach and carefully handle the surrounding tissues to allow for volar plate repair.
36.9 Difficulties Encountered
Carefully planned and executed osteotomies are required. Jagged osteotomy cuts or creation of comminution during this step can complicate the plating and osteosynthesis.
36.10 Key Procedural Steps
36.10.1 Extension Block Pinning
Useful for less involved articular fractures (30-40%) that are able to maintain an acceptable arc of motion (up to 90 degrees) and be closed reduced. This technique exclusively addresses the dislocation component of the injury. A 0.045-inch K-wire is placed obliquely into the proximal phalangeal head to prevent full extension of the PIPJ. The pin is passed between the central tendon and lateral bands. Generally, 30 degrees of joint flexion is maintained to the joint. If greater than 30 degrees flexion is required to achieve reduction of the fracture, a different tech-nique should be selected. This technique prevents dorsal subluxation of the joint while allowing active flexion. The pin is removed at 2 to 3 weeks.