Creator: Dr. Mohammed hutaif
Published: 2026-04-12T14:34:50.373829+00:00

Introduction to Proximal Interphalangeal Joint Fracture-Dislocations

Fracture-dislocations of the proximal interphalangeal (PIP) joint represent some of the most challenging intra-articular injuries in hand surgery. The PIP joint is a highly constrained, bicondylar hinge joint critical for the functional sweep of the digit. Dorsal fracture-dislocations typically involve a shear or impaction injury to the volar base of the middle phalanx. When the articular defect exceeds 40% to 50% of the joint surface, the collateral ligament insertions are compromised, rendering the joint highly unstable and prone to dorsal subluxation.

The Eaton and Malerich Volar Plate Arthroplasty is a foundational reconstructive procedure designed to address this instability. By excising the comminuted volar articular fragments and advancing the robust volar plate into the defect, the surgeon effectively resurfaces the joint, restores the volar buttress, and re-establishes the critical tether against dorsal subluxation.

This comprehensive masterclass details the surgical execution of the Eaton-Malerich technique for both acute injuries and chronic malunions, providing orthopedic residents, hand fellows, and practicing consultants with an evidence-based framework for achieving optimal functional outcomes.

Surgical Anatomy and Biomechanics

A profound understanding of PIP joint anatomy is prerequisite to executing a successful volar plate arthroplasty.

The Volar Plate

The volar plate is a thick, fibrocartilaginous structure that forms the floor of the PIP joint. Proximally, it is attached to the proximal phalanx via two stout check-rein ligaments. Distally, it inserts firmly into the volar base of the middle phalanx. Its primary biomechanical function is to prevent hyperextension of the PIP joint. In the Eaton-Malerich procedure, the distal insertion is detached (or is already avulsed with the fracture fragment), and the plate is advanced distally into a surgically created trough.

The Collateral Ligament Complex

The collateral ligament complex consists of the proper collateral ligament (PCL) and the accessory collateral ligament (ACL).
* Proper Collateral Ligament: Originates from the condylar recess of the proximal phalanx and inserts into the volar-lateral base of the middle phalanx. It is taut in flexion.
* Accessory Collateral Ligament: Originates volar to the PCL and inserts directly into the lateral margins of the volar plate.

💡 Clinical Pearl: Ligamentous Management

During volar plate advancement, the accessory collateral ligaments must be meticulously detached from the volar plate to allow adequate distal excursion. Failure to release the ACLs will tether the volar plate, preventing it from reaching the middle phalanx trough and resulting in inadequate reduction or excessive tension.

Indications and Contraindications

Indications

Acute Dorsal Fracture-Dislocations: Involving >40% of the volar articular surface of the middle phalanx where closed reduction is unstable or impossible.
Comminuted Volar Lip Fractures: Where primary screw fixation or pinning of the fragments is technically unfeasible due to severe comminution.
Chronic/Malunited Fracture-Dislocations: Older injuries (typically >3-4 weeks) presenting with persistent dorsal subluxation, pain, and limited range of motion.

Contraindications

Volar Fracture-Dislocations: The Eaton-Malerich technique is specifically for dorsal dislocations.
Massive Articular Destruction: If the defect exceeds 60-70% of the articular surface, or if the dorsal cortex is compromised, alternative procedures such as hemi-hamate arthroplasty, dynamic external fixation, or primary arthrodesis should be considered.
Inadequate Proximal Phalanx Bone Stock: Severe osteopenia or concurrent fractures of the proximal phalanx that preclude secure suture passage.

Preoperative Planning and Setup

Imaging: True lateral, posteroanterior (PA), and oblique radiographs of the affected digit are mandatory. A true lateral is critical to assess the percentage of articular involvement and the degree of dorsal subluxation.
Anesthesia: Regional block (axillary or supraclavicular) or general anesthesia. Wide-awake local anesthesia no tourniquet (WALANT) can be utilized by experienced surgeons to assess active intraoperative stability.
Positioning: Supine with the arm extended on a radiolucent hand table.
Tourniquet: An upper arm pneumatic tourniquet is typically inflated to 250 mmHg following exsanguination, unless WALANT is employed.
Equipment: Mini-C-arm fluoroscopy, microsurgical instruments, 0.035-inch and 0.045-inch Kirschner wires (K-wires), 3-0 or 4-0 non-absorbable braided suture (or modern suture anchors), and a pull-out button.

Surgical Technique: Acute Injuries (Eaton and Malerich)

The following steps detail the classic open reduction and volar plate advancement for acute PIP joint fracture-dislocations.

1. Surgical Approach

Make a volar incision using an elongated V-shaped design, with the apex of the V at the mid-axial line and the flap based radially (or ulnarly, depending on surgeon preference and injury morphology). Alternatively, a standard Bruner zigzag incision centered over the PIP joint provides excellent exposure.
Elevate the skin flaps, taking meticulous care to identify and protect the neurovascular bundles bilaterally. Retract the bundles with the skin flaps.

2. Flexor Tendon Sheath Management

Identify the flexor tendon sheath.
Excise the cruciform pulleys and the A3 pulley over the PIP joint sufficiently to allow the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons to be retracted laterally.
Crucial Step: Preserve the A2 pulley proximally and the A4 pulley distally to prevent postoperative flexor tendon bowstringing.

3. Joint Exposure and Preparation

With the flexor tendons retracted, hyperextend the PIP joint. This "shotgun" maneuver opens the joint volarly, allowing direct visualization of the fracture fragments and the articular surface in fresh injuries.
The volar plate will typically be found still attached to the comminuted bone fragments of the middle phalanx.
Detach the accessory collateral ligaments from both lateral margins of the volar plate. This step is vital for freeing the volar plate and allowing it to be mobilized distally.

4. Fragment Excision and Trough Creation

Detach the comminuted bone fragments from the distal margin of the volar plate using sharp dissection.
Note on Acute Injuries: In acute settings, the proper collateral ligaments and the dorsal joint capsule generally do not need to be incised, as the joint can be hinged open through the fracture site.
Prepare the recipient site on the middle phalanx. Use a micro-curette or a high-speed burr to create a transverse trough at the volar base of the middle phalanx, precisely at the site of the bone deficit.
Drill two small holes (using a 0.035-inch K-wire) at the extreme lateral margins of this trough. The holes should be directed dorsally and slightly proximally to emerge on the dorsal cortex of the middle phalanx.

⚠️ Surgical Warning: Trough Placement

The trough must be created exactly at the margin of the remaining intact articular cartilage. If the trough is placed too volarly or distally, the advanced volar plate will not adequately resurface the joint, leading to a step-off, recurrent dorsal subluxation, and early post-traumatic osteoarthritis.

5. Volar Plate Advancement and Fixation

Place a pull-out wire (or a heavy non-absorbable suture, such as 3-0 Prolene or FiberWire) through the distal margin of the volar plate. A Bunnell or Krackow grasping stitch is recommended to ensure a secure hold on the fibrocartilaginous tissue.
Pass the two ends of the suture through the pre-drilled holes in the middle phalanx trough, emerging dorsally. Straight Keith needles are highly effective for passing these sutures.
Apply longitudinal traction to the sutures. This action will snug the volar plate directly into the articular defect, effectively resurfacing the volar aspect of the joint and restoring the volar buttress.
Tie the sutures over a padded dorsal button to secure the volar plate in the trough.

💡 Clinical Pearl: Modern Modifications

While the classic Eaton-Malerich technique utilizes a dorsal pull-out button, many contemporary hand surgeons prefer using micro-suture anchors (1.3mm or 1.5mm) placed directly into the middle phalanx trough. This eliminates the need for a dorsal button, reducing the risk of dorsal skin necrosis and simplifying postoperative care, while providing equivalent biomechanical pull-out strength.

6. Joint Reduction and Stabilization

Maintain the joint reduction by flexing the PIP joint. The joint should be flexed no more than 35 degrees. Excessive flexion indicates that the volar plate has been advanced too far or that the joint remains highly unstable, which will lead to a severe postoperative flexion contracture.
Assess the congruity of the reduction using mini-C-arm fluoroscopy. Ensure there is no dorsal subluxation and that the joint space is symmetric.
Once congruity is confirmed, insert a 0.045-inch Kirschner wire obliquely across the PIP joint to maintain the reduction and protect the volar plate repair.
Close the wound in layers and place the hand and finger in a well-padded volar splint.

Surgical Technique: Malunited and Chronic Fractures

Chronic fracture-dislocations present a significantly higher degree of surgical difficulty due to soft tissue contractures, scar formation, and bony remodeling. The Eaton-Malerich technique can be adapted for these old injuries, but requires extensive soft tissue release.

1. Extensive Soft Tissue Release

In old injuries where the fractures have malunited, the volar plate is often scarred and contracted. Divide the volar plate as far distally as possible to maximize its length for advancement.
It is frequently necessary to completely excise both collateral ligaments to mobilize the joint and allow for concentric reduction.

2. Trough Creation and Alignment

Create a transverse trough at the proximal edge of the middle phalanx.
Critical Step: Extend the trough completely across the width of the bone. Ensure the trough is perfectly perpendicular to the long axis of the middle phalanx to avoid inducing an iatrogenic angular deformity (coronal plane deviation) when attaching the volar plate.

3. Assessing Passive Motion and Dorsal Release

Before securing the volar plate, assess the passive range of motion of the PIP joint.
The passive PIP joint flexion must reach 110 degrees. This degree of flexion is necessary to allow the fingertip to easily touch the distal palmar crease.
Because volar plate advancement inherently restricts extension, failing to achieve full flexion intraoperatively will result in a severely limited, non-functional arc of motion.
If passive motion does not reach 110 degrees, perform a sequential dorsal capsular release. Elevate the extensor apparatus and release the dorsal capsule until the requisite flexion is achieved.
Once 110 degrees of passive flexion is confirmed, attach the volar plate into the trough as described in the acute technique.

🛑 Pitfall: Inadequate Flexion in Chronic Cases

Do not accept less than 110 degrees of passive flexion before fixing the volar plate in a chronic case. The postoperative scarring will only further restrict motion. If 110 degrees cannot be achieved despite dorsal capsulotomy, the surgeon must consider alternative salvage procedures, such as joint arthrodesis.

Postoperative Care and Rehabilitation Protocol

The success of a volar plate arthroplasty relies as much on meticulous postoperative rehabilitation as it does on surgical execution. The goal is to protect the repair while preventing debilitating stiffness.

Weeks 0 to 2: Immobilization

The digit is maintained in the static postoperative splint with the PIP joint pinned in the reduced position (typically 20 to 30 degrees of flexion).
Pin site care is performed to prevent infection.
Active range of motion of the metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints is encouraged to prevent tendon adhesions.

Week 2: Pin Removal and Guarded Motion

At exactly 2 weeks postoperatively, the transarticular Kirschner wire is removed in the clinic.
A dorsal block splint is fabricated. The splint is set to block extension at the angle of stability (usually 20 to 30 degrees of flexion).
Active, guarded flexion is initiated within the constraints of the dorsal block splint. The patient is encouraged to actively flex the PIP joint to maintain flexor tendon glide and joint mobility.

Week 3: Suture Removal

If a classic pull-out wire and dorsal button were used, they are removed at 3 weeks postoperatively. (If internal suture anchors were used, this step is bypassed).
The dorsal block splint is adjusted weekly, increasing permitted extension by 10 degrees per week, provided there is no radiographic evidence of recurrent dorsal subluxation.

Week 5 and Beyond: Extension Recovery

By 5 weeks postoperatively, the dorsal block splint is discontinued, and the goal is to achieve full active extension.
If a flexion contracture persists (which is common due to the nature of the volar plate advancement), a dynamic extension splint or serial static extension casting should be implemented.
Strengthening exercises are typically initiated at 8 weeks postoperatively.
Patients should be counseled that maximal medical improvement and final range of motion may take up to 6 to 12 months to achieve.

Complications and Management

Flexion Contracture: The most common complication. Advancing the volar plate inherently shortens the volar structures. Meticulous adherence to the postoperative dynamic splinting protocol is essential. Mild contractures (10-15 degrees) are often well-tolerated and functionally insignificant.
Recurrent Dorsal Subluxation: Usually results from inadequate volar plate advancement, placing the trough too far volarly, or premature removal of the transarticular K-wire. Salvage may require revision arthroplasty, hemi-hamate grafting, or arthrodesis.
Hardware Complications: Dorsal skin necrosis under the pull-out button can occur if tied too tightly or if swelling is excessive. Using a well-padded button or transitioning to modern suture anchors mitigates this risk.
Joint Stiffness: A universal risk in PIP joint trauma. Emphasize early, controlled active flexion and ensure the flexor tendon sheath (A2 and A4 pulleys) was respected during the surgical approach.

Conclusion

The Eaton-Malerich volar plate arthroplasty remains a highly effective, time-tested surgical solution for unstable dorsal fracture-dislocations of the PIP joint. By meticulously respecting the surgical anatomy, achieving precise placement of the middle phalanx trough, and adhering to a strict, phased postoperative rehabilitation protocol, orthopedic surgeons can restore joint congruity and achieve excellent functional outcomes for both acute and chronic presentations.

Authoritative Medical Review

This academic synthesis is based on established protocols from Hutaifortho's Operative Orthopaedics and has been medically reviewed by Prof. Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon. It is designed to assist orthopedic residents, fellows, and practicing surgeons in surgical preparation and board reviews (AAOS, FRCS, Arab Board).

Clinical Disclaimer: The surgical techniques, indications, and medical guidance detailed herein are for advanced educational purposes only. They do not supersede institutional guidelines or independent surgical judgment.

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Key Takeaway