Metacarpal and Phalangeal Fractures Management

Fractures of the metacarpals and phalanges are among the most common upper extremity injuries, accounting for a significant percentage of hand fractures. Understanding their proper management is crucial for restoring hand function and preventing long-term complications. This guide provides a comprehensive overview of metacarpal and phalangeal fractures, covering their types, diagnosis, and treatment options, perfect for students studying this vital topic.

Historically, these fractures were primarily managed non-operatively. However, advancements in materials, implant designs, imaging, and specialized surgical techniques have expanded operative options over the last 80 years. Despite these advancements, most fractures can still be successfully treated non-operatively.

Understanding Metacarpal and Phalangeal Fractures Management

Effective metacarpal and phalangeal fractures management requires a nuanced approach, considering various factors such as fracture location (intra-articular vs. extra-articular), geometry (transverse, spiral, oblique, comminuted), and severity of deformity (angular, rotational, shortening). Other vital considerations include whether the fracture is open or closed, associated soft tissue injuries, intrinsic stability, patient age, occupation, systemic illnesses, and surgeon's skill.

When is Fixation Necessary? Indications for Operative Treatment

While many hand fractures heal well with non-operative methods, certain situations necessitate operative fixation. According to the source materials, key indications for fixation of metacarpal and phalangeal fractures include:

• Irreducible fractures
• Malrotation (especially spiral and short oblique fractures)
• Intra-articular fractures
• Subcapital fractures (phalangeal)
• Open fractures
• Segmental bone loss
• Polytrauma with hand fractures
• Multiple hand or wrist fractures
• Fractures with soft tissue injury (vessel, tendon, nerve, skin)
• Reconstruction (e.g., osteotomy)

Risks and Benefits of Operative Fixation

Operative fixation has become increasingly popular due to improved implants, better biomechanical understanding, public expectations, advanced imaging (CT, mini-fluoroscopy), specialist availability, and better anesthesia and therapy support. However, prolonged immobilization should be avoided to prevent stiffness, and overly aggressive fixation can lead to soft tissue damage, tendon adhesions, and infection. The goal is an outcome as good as, or better than, non-operative management.

Metacarpal Fractures: Types and Treatments

Metacarpal fractures are broadly categorized by their location and characteristics.

Metacarpal Head Fractures: Intra-Articular Challenges

Fractures of the metacarpal head are rare and typically intra-articular. The index metacarpal is most frequently involved due to its border digit status and relatively immobile carpometacarpal (CMC) joint. These fractures are classified into several categories:

• Epiphyseal (nondisplaced Salter-Harris type III)
• Ligamentous avulsions
• Osteochondral slices
• Three-part fractures (sagittal, coronal, axial)
• Comminuted fractures (most common, often leading to loss of MP joint flexion)
• Boxer's fractures with joint extension
• Fractures with substance loss
• Occult compression fractures with avascular necrosis

Radiographic evaluation requires posteroanterior, lateral, and oblique views. The Brewerton view (MP joint flexed 65 degrees) can enhance visualization of the articular contour. Treatment is individualized.

Treatment Options for Metacarpal Head Fractures:

• Open Reduction and Internal Fixation (ORIF): Recommended for displaced ligament avulsion fractures, osteochondral fractures, and two-part coronal, sagittal, and oblique intra-articular fractures. Fixation often uses Kirschner pins or interfragmentary screws. For open fractures due to clenched-fist injuries, formal irrigation and debridement are necessary, often delaying internal fixation.
• Skeletal Traction or Silicone Arthroplasty: Alternatives for severely comminuted intra-articular fractures, especially if ORIF is difficult or impossible.
• Osteochondral Autografts: Used in cases of partial loss of a metacarpal head, with successful short-term results reported using metatarsal grafts.

Authors' Preferred Method for Metacarpal Head Fractures: Non-comminuted fractures exceeding 25% of the articular surface or with >1 mm articular step-off are treated operatively via a dorsal longitudinal incision splitting the extensor tendon. Headless screws are preferred for two-part fractures. Comminuted fractures are stabilized with multiple Kirschner pins or cerclage wires. If stabilization fails, immobilization for 2-3 weeks (MP joint flexed 70 degrees) followed by intensive range of motion is used. Prosthetic arthroplasty is an option for open comminuted head fractures with bone loss, except for the index finger due to high shear stresses.

Complications: Stiffness is common, resulting from extensor tendon adhesions, collateral ligament/dorsal capsular contracture, or articular incongruity. Avascular necrosis can also occur, particularly in young adults involving the index and middle fingers.

Metacarpal Neck Fractures: The Boxer's Fracture

Metacarpal neck fractures, commonly known as "Boxer's fractures," typically involve the ring and small metacarpals. This term is often a misnomer, as they are more common in brawlers or those hitting solid objects. These fractures occur when a clenched MP joint strikes a solid object, causing apex dorsal angulation due to impact on the metacarpal head and intrinsic muscle pull.

Treatment Controversies: Optimal treatment varies, from non-operative to various internal fixation techniques. Nonunion is uncommon, but malunion can cause loss of metacarpal head prominence, diminished range of motion, a palpable metacarpal head in the palm, and rotational malalignment.

Factors Influencing Treatment:

1. Which metacarpal neck is fractured: Ring and small fingers tolerate more angulation (20-30 degrees mobility at CMC joint) than index and middle fingers (less mobility).
2. Degree of angulation: Difficult to measure consistently, but considerable angulation (e.g., up to 70 degrees in the small finger) may be acceptable without significant disability.
3. Presence of rotational deformity: Poorly tolerated and requires correction.

Closed Reduction of Metacarpal Neck Fractures: The Jahss maneuver (flexing MP joint to 90 degrees) is the best technique for closed reduction, relaxing intrinsic muscles and tightening collateral ligaments. However, prolonged immobilization in the "Jahss position" for the small finger should be avoided due to skin necrosis or permanent PIP stiffness risks.

Percutaneous Pinning: A popular method for maintaining closed reduction in metacarpal neck and shaft fractures. Techniques include longitudinal, crossed, or transverse Kirschner pins. "Bouquet" osteosynthesis, an antegrade intramedullary fixation using pre-bent Kirschner pins, has shown good results, avoiding the fracture site.

Open Reduction of Metacarpal Neck Fractures: Indicated when closed manipulation fails to restore acceptable alignment. Mini-condylar blade plates can be used for rigid stabilization, but higher complication rates are reported with open fractures or soft tissue injury.

Authors' Preferred Method for Metacarpal Neck Fractures: Most closed ring and small finger fractures are treated non-operatively, especially without pseudoclawing or rotational malalignment. A functional brace (forearm-based, dorsal-ulnar gutter splint) is used, with the wrist extended 30 degrees and MP joints flexed 70 degrees, encouraging active range of motion.

For pseudoclawing or rotational deformity, closed manipulation with the Jahss maneuver is performed. Acceptable angulation is up to 15 degrees for index/middle, 30-40 degrees for ring, and 50-60 degrees for small finger (though <40 degrees for extensive grippers). If reduction cannot be maintained, percutaneously inserted crossed Kirschner pins or antegrade intramedullary fixation is preferred.

Metacarpal Shaft Fractures: Transverse, Oblique, and Comminuted

Metacarpal shaft fractures are classified as transverse, oblique/spiral, or comminuted. Each type presents characteristic deformities. Oblique views may be helpful for diagnosis.

Deformities and Acceptable Angulation/Shortening:

• Transverse fractures: Usually apex dorsal angulation due to axial loading and interosseous muscle forces. Reduction is needed for angulation >30 degrees (small finger), >20 degrees (ring finger), and any angulation (middle/index).
• Oblique and Spiral fractures: Result from torsional forces, causing rotational malalignment (scissoring), which is poorly tolerated and often requires open reduction.
• Comminuted fractures: Caused by direct impact, often with soft tissue injury and shortening. Opinions vary, but 2-5 mm shortening is generally acceptable.

Undesirable effects of dorsal angulation: prominent metacarpal head in palm, pseudoclaw deformity, aesthetic concerns, intrinsic muscle weakening.

Closed Reduction and Plaster Immobilization: Effective for most stable, nondisplaced fractures. A short arm cast with wrist 30-40 degrees extension and MP joints 80-90 degrees flexion (intrinsic-plus/clam-digger position) is advocated, allowing IP joint motion. Active motion is encouraged. The cast is maintained for about 4 weeks.

Closed Reduction and Percutaneous Pinning: Antegrade or retrograde pinning can stabilize fractures with minimal soft tissue injury. Various pin configurations exist. This allows for early motion. Pin types include longitudinal, transverse, and crossed. Transverse pins through adjacent metacarpals offer good stability.

Open Reduction Indications:

• Open fractures (with bone loss, contamination, soft tissue injury)
• Multiple fractures (loss of adjacent metacarpal stability)
• Unstable fractures (especially border metacarpals)
• Rotational malalignment unresponsive to closed methods

Techniques of Open Reduction for Metacarpal Shaft Fractures:

• Kirschner Pins: Versatile, easy to insert, minimal dissection. Not rigid, may loosen/migrate, risk of pin tract infection. Can be used alone or to supplement other fixation.
• Composite (Tension Band) Wiring: Combines Kirschner pins with stainless steel wire for added stability and compression. Rigid enough for early motion. Contraindicated with bone loss, comminution, or osteopenia.
• Cerclage and Interosseous Wiring: Circumferential wiring (cerclage) or dorsal-volar interosseous wires. Can provide sufficient fixation, sometimes without immobilization.
• Intramedullary Fixation: Applicable for transverse fractures, easy to perform, allows early active motion. Potential disadvantages include rotational instability and pin migration. Can be open or percutaneous.
• Interfragmentary Compression Screws: Provides stable fixation for long oblique and spiral fractures, allowing early motion. Technically demanding, requires special equipment. Must be placed precisely to lag and compress the fracture.
• Plate Fixation: Used for multiple fractures with soft tissue injury or bone loss, or markedly displaced border metacarpal shaft fractures. Provides rigid fixation and maintains length. However, it requires extensive exposure, may lead to complications (malunion, nonunion, stiffness, loosening/breakage), and may require removal.
• External Fixation: Indicated for severe fractures where anatomic reconstitution is not feasible (e.g., highly comminuted open fractures with bone loss, displaced intra-articular fractures, significant soft tissue injury). Preserves bone biology and allows wound access, but risks pin tract infection, osteomyelitis, and overdistraction.

Authors' Preferred Method for Metacarpal Shaft Fractures: Most stable fractures are managed non-operatively with a clam-digger cast/splint and buddy taping, initiating immediate finger flexion. For transverse fractures, closed reduction and well-molded casting are used, with MP joints at 60 degrees flexion and careful rotational alignment. Closed manipulation and percutaneous pinning are chosen if reduction is difficult to maintain or with concomitant soft tissue injury. For open reduction, Kirschner pins are preferred for isolated short oblique and transverse fractures, supplemented with composite wiring. Intramedullary pins are useful for multiple open transverse fractures. Spiral and long oblique fractures are suited for interfragmentary screw fixation. Plate and screw fixation is reserved for complex situations like open, multiple shaft fractures with bone loss or significant soft tissue injury.

Metacarpal Base Fractures and Carpometacarpal Fracture-Dislocations

These fractures often present unique challenges due to joint immobility or instability.

• Avulsion Fractures of Second and Third Metacarpal Bases: Rare due to limited joint motion. Successfully managed both operatively and non-operatively. Surgical reattachment aims to restore extensor carpi radialis integrity and articular surface.
• Ring Finger CMC Joint Dislocations: Uncommon, may be associated with metacarpal fracture, and often missed. CT may be helpful.
• Small Finger CMC Joint Fracture-Dislocations: Common, associated with proximal and dorsal subluxation of the metacarpal. Displacement is accentuated by extensor carpi ulnaris pull. Specific radiographic views (forearm pronated 30 degrees) are recommended.
• Multiple CMC Dislocations: High-energy injuries nearly always requiring ORIF. Closed reduction is often unsuccessful due to redislocation.

Authors' Preferred Method for CMC Joint Injuries: For unstable fifth CMC joint fracture-dislocations, closed reduction and percutaneous pinning are preferred, pinning the fifth metacarpal shaft into the fourth. For multiple CMC joint dislocations, closed reduction and percutaneous pinning or ORIF are indicated. For symptomatic arthritis, secondary arthrodesis (fusion) using an iliac crest bone graft can be performed, which does not significantly compromise hand function.

Complications of Metacarpal Fractures

Complications can significantly impact hand function and patient satisfaction.

Malunion: Angulatory, Rotational, or Shortening

Malunions can be angulatory (apex dorsal), rotational (scissoring of fingers), or lead to shortening. Rotational malunion is poorly tolerated and often requires corrective osteotomy.

• Corrective Osteotomy: For angulatory malunion, closing wedge osteotomy is simpler, or opening wedge osteotomy with bone graft for significant shortening. For rotational malunion, osteotomy through the base or shaft can correct deformity, fixed with pins or plates.
• Intra-articular Malunions: Rarely amenable to corrective osteotomy. If feasible, osteotomy with articular surface reconstitution is optimal.

Osteomyelitis: Infection After Fixation

Osteomyelitis is uncommon but serious. Delay in treatment or multiple procedures is associated with high amputation rates. Treatment involves thorough debridement, removal of hardware, bone cultures, intravenous antibiotics, and sometimes bone grafting or soft tissue coverage.

Nonunion: Failure to Heal

Metacarpal nonunions are rare but more common in open, comminuted, or infected fractures, or those with bone loss. Treatment often involves surgical debridement, bone grafting, and rigid internal fixation.

Phalangeal Fractures: Distal, Middle, and Proximal

Phalangeal fractures are also very common, with varied presentations and management strategies.

Distal Phalanx Fractures: Tuft, Shaft, and Epiphyseal

These are the most common phalangeal fractures.

• Tuft Fractures: Usually from crushing injuries, often with nail matrix/pulp lacerations. Symptomatic subungual hematomas need decompression. Immobilization for 10-14 days. Comminuted tuft fractures rarely need internal fixation; focus is on pulp and nail matrix repair. The nail plate is useful for maintaining reduction.
• Shaft Fractures: Transverse and longitudinal types. Nondisplaced transverse fractures are stable. Displaced transverse fractures may be open, with nail matrix laceration, requiring longitudinal Kirschner pin fixation and matrix repair.
• Epiphyseal Fractures: Common in children (toddlers) from hyperflexion, potentially leading to foreshortened digits. Often associated with transverse nail matrix laceration and dorsal nail plate avulsion (Seymour fracture). Treatment involves irrigation, debridement, fracture reduction, nail matrix repair, and nail plate replacement as a stent. Postoperative splinting in extension.

Complications: Symptomatic nonunion of distal phalanx waist. Late presentation of pediatric epiphyseal fractures can lead to a dorsal bump.

Fractures of the Middle and Proximal Phalanges

Improper treatment of unstable fractures here often leads to stiffness and deformity. Factors like patient age, articular injury, and comminution negatively affect mobility.

Nonarticular Fractures of the Phalanges:

• Neck Fractures (Subcapital/Subcondylar): Uncommon in adults, managed by reduction and splinting or percutaneous pinning. Common in toddlers, caused by finger entrapment; displacement of the head fragment dorsally and rotated 90 degrees is characteristic and requires open reduction. Pines left for 4-5 weeks. Complications include persistent angulation, limited extension/flexion, and nonunion.
• Shaft Fractures: Transverse, oblique/spiral, and comminuted. Spiral/oblique fractures are more common in the proximal phalanx, transverse in the middle phalanx. Proximal phalangeal fractures typically have apex volar angulation.

Articular Fractures of the Phalanges:

• Condylar Fractures of Proximal Phalanx: Result from direct impact or axial load with torsion. Unicondylar fractures are nearly all unstable and typically require operative fixation (ORIF with Kirschner pins or lag screws). Weiss-Hastings classification includes oblique volar, long sagittal, dorsal coronal, and volar coronal types. Bicondylar fractures are often displaced and comminuted, usually requiring ORIF.
• Pilon Fractures of PIP Joint: Intra-articular comminuted fractures of the middle phalanx base. Often involve dorsal impaction and palmar subluxation. Treatment is challenging, ranging from skeletal traction and dynamic external fixation to ORIF. Maintaining reduction and allowing early motion are key. Complications include stiffness and post-traumatic arthritis.
• Dorsal, Volar, or Lateral Base Fractures: Avulsion fractures from dorsal base of middle phalanx (central tendon detachment) or volar plate avulsions from proximal phalanx base. Treated based on stability and size, ranging from closed reduction and splinting to ORIF with mini-screws or pull-out sutures.

Authors' Preferred Method for Phalangeal Fractures: Stable, nondisplaced fractures are managed with buddy taping or splint immobilization. Unicondylar fractures of the proximal phalanx are highly unstable and often need ORIF with two Kirschner pins or lag screws. Bicondylar fractures require ORIF. Pilon fractures are complex; stable reduction allowing early motion is the goal. For dorsal avulsion fractures of the middle phalanx, ORIF with Kirschner pins or tension band wiring is performed if >30% of joint surface is involved. Volar plate avulsions of the proximal phalanx require ORIF for significant displacement and instability.

Expected Outcomes and Rehabilitative Management

Most metacarpal shaft fractures are stable and can be treated conservatively with good outcomes. For phalangeal fractures, rigid constructs allowing immediate mobilization often yield better results than non-rigid ones. Early range of motion is crucial for all hand fractures to prevent stiffness.

After ORIF, periosteum approximation is preferred. A forearm-based plaster splint for 4-7 days is followed by active range of motion exercises, with the wrist slightly extended. Elastic garments control edema, and IP joints are splinted in extension during MP flexion exercises. Hardware removal depends on the implant type, with Kirschner wires typically removed at 3-6 weeks and plates/screws after about 6 months, though routine plate removal is not always necessary.

FAQ: Metacarpal and Phalangeal Fractures Management for Students

What are the main types of metacarpal fractures and their common causes?

Metacarpal fractures can involve the head, neck, shaft, or base. Head fractures are often intra-articular, while neck fractures (Boxer's fractures) commonly affect the ring and small fingers from striking solid objects. Shaft fractures can be transverse, oblique, or comminuted, caused by axial loading or torsional forces. Base fractures and carpometacarpal fracture-dislocations are often high-energy injuries, sometimes affecting the small finger CMC joint.

How is a "Boxer's fracture" typically managed, and what angulation is acceptable?

Boxer's fractures (metacarpal neck fractures) can be managed non-operatively with a functional brace for many patients, especially without pseudoclawing or rotational deformity. If reduction is needed, the Jahss maneuver is used. Acceptable angulation varies by digit: up to 15 degrees for index/middle, 30-40 degrees for the ring finger, and 50-60 degrees for the small finger, although some surgeons prefer less for active grippers.

What are the critical points for operative management of metacarpal head fractures?

Operative management is indicated for displaced condylar fractures, particularly if >25% of the articular surface is involved or there's >1mm step-off. Fixation usually involves two Kirschner pins or lag screws to provide stability. Care must be taken to preserve collateral ligaments and achieve anatomic reduction, with early active motion initiated post-operatively to prevent stiffness.

What complications can arise from metacarpal and phalangeal fractures?

Complications include malunion (angulatory, rotational, or shortening deformities), nonunion (failure of bone to heal), stiffness (due to extensor tendon adhesions, capsular contracture, or articular incongruity), avascular necrosis (especially in metacarpal head fractures), and osteomyelitis (infection after fixation).

Why is early mobilization important in hand fracture management?

Early mobilization is crucial to prevent permanent stiffness, a common and debilitating complication of hand fractures. It helps maintain joint range of motion, reduce edema, and minimize tendon adhesions. However, it must be balanced with sufficient fracture stability to ensure proper healing. Hand therapists play a vital role in guiding appropriate rehabilitation programs.