summary Phalanx Fractures are common hand injuries that involve the proximal, middle or distal phalanx. Diagnosis can be confirmed with orthogonal radiographs of the involve digit. Treatment involves immobilization or surgical fixation depending on location, severity and alignment of injury. Epidemiology Incidence most common injuries to the skeletal system accounts for 10% of all fractures Demographics more common in males 2:1 Location distal phalanx > middle phalanx > proximal phalanx small finger is most commonly affected (accounts for 38% of all hand fractures) Etiology Pathophysiology mechanism of injury depends on age 10-29 years old - sports is most common 40-69 years old - machinery is most common >70 years old - falls are most common Associated conditions nail bed injuries associated with distal phalanx fractures Anatomy Osteology distal phalanx 4 components tuft shaft base middle and proximal phalanx 4 components head neck shaft base displacement of middle phalanx fracture apex dorsal fracture proximal to FDS insertion apex volar fracture distal to FDS insertion displacement of proximal phalanx fracture apex volar proximal fragment flexed due to interossei distal fragment extends due to central slip Arthrology interphalangeal joint hinge joint dynamic stability from compressive forces during pinch and grip passive stabiltiy from collateral ligament Ligaments collateral ligaments proper accessory Tendons terminal extensor tendon inserts on dorsal base of distal phalanx FDP inserts on volar base of distal phalanx central slip terminal slip of EDC inserts on dorsal aspect of middle phalanx FDS inserts on volar shaft of middle phalanx Blood Supply proper digital arteries dominant artery found on median side of phalanges (closer to midline) Nervous System proper digital nerves volar to proper digital arteries Biomechancis Classification Descriptive proximal phalanx location head fractures type I - stable with no displacement type II - unstable unicondylar type III - unstable bicondylar or comminuted neck/shaft fractures short oblique long oblique spiral transverse base fractures extra-articular intra-articular lateral base middle phalanx location head fractures type I - stable with no displacement type II - unstable unicondylar type III - unstable bicondylar or comminuted neck fractures apex volar angulation shaft fractures transverse short oblique long oblique spiral deformity apex volar angulation distal to FDS insertion apex dorsal angulation proximal to FDS insertion without angulation due to inherent stability provided by an intact and prolonged FDS insertion base fractures deformity is usually apex dorsal angulation proximal fragment in extension (due to central slip) distal fragment in flexion (due to FDS) can be further classified into partial articular fractures volar base results from hyperextension injury or axial loading represents avulsion of volar plate unstable if > 40% articular surface involved dorsal base results from hyperflexion injury represents avulsion of central tendon lateral base represents avulsion of collateral ligaments complete articular fractures know as pilon fractures unstable in all directions distal phalanx Classification tuft fractures mechanism is usually crush injury usually stable due to nail plate dorsally and pulp volarly often associated with laceration of nail matrix or pulp shaft fractures can be transverse longitudinal base fractures usually unstable mechanism can be shearing due to axial load, leading to fracture involving > 20% of articular surface avulsion due tensile force of terminal tendon or FDP, leading to small avulsion fracture can be further classified into volar base dorsal base Seymour fractures epiphyseal injury of distal phalanx resuls from hyperflexion presents as mallet deformity (i.e. apex dorsal) due to terminal tendon attaches to proximal epiphyseal fragment FDP attaches to distal fragment intra-articular vs extra-articular fracture morphology amount of displacement open vs closed Presentation History hand dominance baseline function occupation and hobbies mechanism of injury Physical Exam inspection swelling ecchymosis deformity (angular, rotation, shortening) open wounds motion assess for scissoring of digits indicates rotational component assess via tenodesis neurovascular digital nerve two-point discrimination test vascular assessment cap refill <2 sec Imaging Radiographs recommended views PA lateral oblique findings proximal phalanx apex volar angulation due to proximal fragment pulled into flexion by interossei distal fragment pulled into extension by central slip middle phalanx apex volar angulation if distal to FDS insertion apex dorsal angulation if proximal to FDS insertion CT scan indications assess articular involvement findings amount of articular displacement degree of comminution Differential Differential Diagnosis Stress fracture Jammed finger fracture-dislocation gout finger infection neoplasm Diagnosis Radiographs diagnosis confirmed by history, physical, and orthogonal radiographs Proximal Phalanx Fractures Nonoperative buddy taping vs. splinting indications extraarticular fractures with < 10° angulation or < 2mm shortening and no rotational deformity non-displaced intraarticular fractures technique 3 weeks of immobilization followed by aggressive motion Operative CRPP vs. ORIF indications extraarticular fractures with > 10° angulation or > 2mm shortening or rotational deformity displaced intraarticular fractures unstable or irreducible fracture pattern Unstable patterns include spiral, oblique, fracture with severe comminution techniques crossed K wires Eaton-Belsky pinning through metacarpal head minifragment fixation with plate and/or lag screws lag screws alone indicated in presence of long oblique fracture Middle Phalanx Fractures Nonoperative buddy taping vs. splinting indications extraarticular fractures with < 10° angulation or < 2mm shortening and no rotational deformity non-displaced intraarticular fractures technique 3 weeks of immobilization followed by aggressive motion Operative CRPP vs. ORIF indications extraarticular fractures with > 10° angulation or > 2mm shortening or rotational deformity displaced intraarticular fractures irreducible or unstable fracture pattern techniques crossed K wires extension block pinning collateral recess pinning minifragment fixation with plate and/or lag screws volar plate arthroplasty hemi-hamate arthroplasty has shown to be a successful treatment option in those with >50% articular involvement Distal Phalanx Fractures Nonoperative closed reduction +/- splinting indications most cases nail matrix may be incarcerated in fracture and block reduction Operative remove nail, repair nailbed, and replace nail to maintain epi fold indications distal phalanx fractures with nailbed injury see nail bed injuries CRPP vs. ORIF indications displaced or irreducible shaft fractures dorsal base fractures with > 25% articular involvement displaced volar base fractures with large fragment and involvement of FDP non-unions techniques longitudinal or crossed K wires extension block pinning minifragment fixation with lag screws Complications Loss of motion most common complication risk factors prolonged immobilization intra-articular fracture extensive surgical dissection treatment aggressive hand therapy first-line treatment surgical release failed nonoperative treatment Malunion types malrotation angulation Apex volar angulation effectively shortens extensor tendon and limits extension of PIPJ shortening treatment nonoperative asymptomatic, no functional impairment surgery indicated when associated with functional impairment options corrective osteotomy at malunion site (preferred) metacarpal osteotomy (limited degree of correction) Nonunion uncommon (<2%) most atrophic and associated with bone loss or neurovascular compromise surgical options resection, bone grafting, plating ray amputation or fusion