Dorsal approach to the PIP joint

The dorsal approach to the proximal interphalangeal (PIP) joint offers access to the extensor tendon, joint capsule, collateral ligaments, and the distal part of the proximal phalanx and the base of the middle phalanx.

This approach may be extended proximally and distally as needed.

Illustration of dorsal approaches to the PIP joint, offering access to extensor tendon, joint capsule, collateral ligaments, and phalanx. Approach can be extended proximally and distally.

This approach is indicated for:

Intraarticular fractures
Dorsal coronal plane fractures of the condyles of the proximal phalanx
Central slip avulsion fractures from the dorsal base of the middle phalanx

$Illustration of dorsal approaches to the PIP joint, indicated for intraarticular fractures, dorsal coronal plane fractures, and central slip avulsion fractures.$

AO teaching video

Finger, proximal interphalangeal joint, dorsolateral approach

AO teaching video

Finger, proximal interphalangeal joint, midline approach

AO teaching video

Finger, proximal interphalangeal joint, dorsal Chamay approach

The interphalangeal joints are hinge joints. The heads of the proximal and middle phalanges each have two articular condyles that resemble a grooved trochlea and assist in preventing adduction/abduction and rotation in conjunction with the collateral ligaments.

Dynamic stability results from compressive forces, which increase during pinch and grip. Passive stability derives from the bone morphology and tension in the collateral ligaments and the volar plate. This passive stability is maximal in full extension.

Illustration of dorsal approaches to the PIP joint, showing hinge joints with articular condyles, dynamic and passive stability mechanisms.

The two collateral ligaments and the volar plate are the primary structures stabilizing the interphalangeal joints and preventing displacement in the coronal plane (abduction/adduction).

The collateral ligaments also prevent side-to-side translational displacement.

The accessory collateral ligaments slacken in flexion, while the true collateral ligament is further tensioned in flexion due to the greater palmar width of the condyles.

Illustration of dorsal approaches to the PIP joint, showing collateral ligaments and volar plate stabilizing interphalangeal joints, preventing displacement.

Nerve identification

Identify and protect the dorsal sensory branches of the radial and ulnar nerves in the thin subcutaneous tissue.

Illustration of dorsal approaches to the PIP joint, showing identification and protection of dorsal sensory branches of radial and ulnar nerves in thin subcutaneous tissue.

Vein identification

The dorsal venous system of the fingers has longitudinal and transverse branches. Be careful to preserve the longitudinal branches. For better exposure, the transverse branches may be ligated or cauterized but preserve as many dorsal veins as possible to avoid congestion and swelling, with consequent fibrosis and stiffness.

Illustration of dorsal approaches to the PIP joint, showing preservation of longitudinal branches and careful handling of transverse branches to avoid congestion and swelling.

Preservation of soft-tissue structures

Preserve the insertion of the central band of the extensor mechanism to the dorsal aspect of the middle phalangeal base. If this is detached and not repaired, a boutonniere deformity may occur.

Illustration of dorsal approaches to the PIP joint, showing preservation of central band insertion to prevent boutonniere deformity.

Several skin incision options are available. Each comes with benefits and disadvantages.

Straight dorsal incision

Perform a straight midline dorsal incision over the PIP joint.

Advantages:

Perfusion and venous drainage are well preserved.
Early postoperative motion will prevent scarring between the skin, tendon, and bone.

Disadvantage:

Skin and tendon scarring are in the same line and tethering may occur.

Illustration of dorsal approaches to the PIP joint, showing a straight midline dorsal incision. Advantages: preserved perfusion and venous drainage, early motion. Disadvantage: potential skin and tendon scarring, leading to tethering.

Curved skin incision

Perform a curved skin incision over the PIP joint. The convexity of the incision is planned so that the scar does not involve the radial border of the index or the ulnar border of the little finger. The fracture morphology and implant placement must be given priority when planning the incision.

Advantage:

Skin and tendon scarring are not in line and tethering due to scarring may be avoided.

Disadvantage:

Relatively poor perfusion at the apex of the curve may risk skin necrosis and delayed healing.

Illustration of dorsal approaches to the PIP joint, showing a curved skin incision over the PIP joint. Advantage: avoids skin and tendon scarring in line. Disadvantage: poor perfusion at the curve's apex may risk skin necrosis and delayed healing.

Zigzag skin incision

A zigzag incision may be used. This approach allows for:

Full exposure of the joint and the shaft
Paratendon or through tendon approach

Depending on the fracture pattern, the incision may be designed with an ulnar or radial apex.

The cutaneous digital nerves on the ulnar side of the 5th finger and the radial side of the 2nd finger should be preserved to protect skin sensitivity.

Advantage:

Skin and tendon scarring are not in line and tethering due to scarring may be avoided.

Disadvantage:

Relatively poor perfusion at the apex of the zigzag, with a risk of skin necrosis and delayed healing.

Illustration of dorsal approaches to the PIP joint, showing a zigzag incision for full exposure of the joint and shaft. Advantage: avoids skin and tendon scarring in line. Disadvantage: poor perfusion at the apex may risk skin necrosis and delayed healing.

Retract and elevate the skin and the subcutaneous tissue as a single layer. The extensor apparatus is fully exposed and intact.

Illustration of dorsal approaches to the PIP joint, showing retraction and elevation of skin and subcutaneous tissue as a single layer, with fully exposed and intact extensor apparatus.

There are four possible approaches:

Option 1: between the central and lateral extensor slips
Option 2: Central midline extensor splitting
Option 3: lateral to the lateral band of the extensor apparatus
Option 4: Elevation of the central slip as a distally based, V-shaped flap (Chamay approach)

Illustration of dorsal approaches to the PIP joint, showing four options: between central and lateral extensor slips, central midline extensor splitting, lateral to lateral band, and elevation of central slip as a V-shaped flap.

Perform an incision in the tendon between the central slip and the lateral band.

Illustration of dorsal approaches to the PIP joint, showing an incision in the tendon between the central slip and the lateral band.

Retraction of the slips exposes the dorsal capsule of the PIP joint.

Illustration of dorsal approaches to the PIP joint, showing retraction of the slips exposing the dorsal capsule of the PIP joint.

Capsulotomy

Perform a vertical capsulotomy to expose the joint.

Pitfall: Detachment of the extensor central slip and the collateral ligaments may cause a boutonnière deformity and should therefore be avoided.

Illustration showing dorsal approaches to the PIP joint with a vertical capsulotomy, avoiding boutonnière deformity.

Flexion for better exposure

Flexing the PIP joint allows the lateral band to move in a palmar direction, giving better exposure to the joint.

Illustration showing dorsal approaches to the PIP joint, flexing it to move the lateral band palmarly.

Perform a straight incision and perform a longitudinal midline tenotomy.

Note: Do not disinsert the central slip.

The disadvantage of this approach is the possibility of developing a boutonnière deformity or lack of extension.

Illustration showing dorsal approaches to the PIP joint with a straight incision and longitudinal midline tenotomy.

Incise lateral to the lateral band.

Divide the transverse retinacular ligament (TRL), using a dental pick inserted between it and the collateral ligament, to avoid accidentally cutting the collateral ligament.

A longitudinal capsulotomy allows the joint to be inspected.

Illustration showing dorsal approaches to the PIP joint, incising lateral to the lateral band and dividing the TRL.

Pitfall – Approach with limited access: The dorsolateral approach does not allow access to the opposite condyle, which in some situations is necessary, notably in irreducible bicondylar fractures.

Illustration showing dorsal approaches to the PIP joint, noting limited access of dorsolateral approach for opposite condyle.

Raise the central extensor slip as a distally based, V-shaped flap, leaving it attached to the base of the middle phalanx.

Perform a transverse dorsal capsulotomy.

Flexing the joint causes the lateral band to slip in a palmar direction, exposing the whole joint.

Illustration showing dorsal approaches to the PIP joint, raising central extensor slip as V-shaped flap, performing transverse dorsal capsulotomy, and flexing joint to move lateral band palmarly.

Regardless of the chosen approach, all tendon incisions must be repaired with nonabsorbable monofilament sutures with an atraumatic needle prior to wound closure.

The following suture dimension should be used: