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Treatment of Dislocations
Distal interphalangeal (DIP), proximal interphalangeal (PIP), and metacarpophalangeal (MCP) dislocations are often suspected on initial inspection. Dislocations are described using the position of the distal bone relative to the more proximal one. Dorsal DIP and PIP dislocation are most common. Radiographs are advised to exclude fracture and confirm dislocation.
Patients with closed DIP, PIP, and MCP dislocation often require digital nerve block prior to closed reduction. Most acute DIP and PIP dislocations are easily reduced on the first attempt. In select patients, after counseling and consent, a single rapid joint reduction attempt without digital nerve block may be considered. Reduction is achieved with distraction traction-counter traction. Inability to reduce the joint requires hand surgeon consultation. Following reduction, all patients require splinting in extension, neurovascular reassessment, confirmatory post-reduction radiographs, and referral to a hand surgeon.
Scapholunate Dissociation
Scapholunate dissociation results from injury of the scapholunate interosseous ligament. The most common mechanism is a high-impact FOOSH with wrist hyperextension and ulnar deviation.1
Physical examination reveals wrist swelling, point tenderness over the scapholunate joint, and decreased range of motion. Patients should be risk-stratified for scaphoid fracture, as the typical mechanism of injury is similar.
Patients with scapholunate diastasis >3 mm,2,3 or clinical suspicion of scapholunate dissociation with equivocal imaging are placed in a thumb spica splint and referred to a hand surgeon. Scapholunate dissociation may require non-emergent surgical intervention to decrease the risk of severe and debilitating wrist dysfunction.
Perilunate Dislocation and Lunate Dislocation
Perilunate dislocation and lunate dislocation are typically discussed together. They most commonly occur due to a high-impact FOOSH injury with wrist hyperextension. Physical examination may demonstrate swelling and deformity of the wrist, point tenderness over the dorsal aspect of scapholunate joint, and decreased range of motion.4
Posterior-anterior radiographs of the wrist are abnormal in perilunate and lunate dislocation; however, lateral views depict a greater degree of carpal bone displacement. Careful radiographic review (with particular attention to the lateral view) should be undertaken because missed injuries occur frequently. A 1993 study by Herzberg et al of 166 patients with perilunate dislocation reported a rate of missed injury of 25%.5
In perilunate dislocation, the lateral radiograph demonstrates displacement of the capitate (typically dorsal) with retention of the lunate articulation with the radius. The posterior-anterior view demonstrates loss of the continuity of the 3 carpal arcs and is referred to as “jumbled carpus.”
In lunate dislocation, the lateral radiograph shows displacement and rotation of the lunate (usually volar), known as the “spilled teacup” sign. The posterior-anterior view in lunate dislocation demonstrates a triangle-shaped lunate, known as the “pie in the sky” sign. Closed reduction of lunate dislocation and perilunate dislocation is often technically difficult. Emergent consultation with a hand surgeon is recommended to coordinate closed reduction versus open reduction and fixation in the operating room.5
Treatment of Fractures
Fractures of Phalanges 2, 3, 4, 5
Distal Phalanx
Distal phalanx fractures are classified into 3 categories: (1) tuft, (2) shaft, or (3) base factures. Focused physical examination should identify point tenderness and associated nail plate injury, tendon injury, or open fracture. Anterior-posterior and lateral radiographs are recommended.6
Displaced, closed distal phalanx fractures require reduction, followed by a volar digital splint immobilizing the DIP joint. All patients with these injuries should be referred to a hand surgeon.
Based on the evidence, prophylactic antibiotics confer no benefit to low-risk open tuft fractures. Stevenson et al performed a double-blind randomized controlled trial of 193 patients with low-risk open distal phalanx fractures, all of whom underwent meticulous wound care in the ED and were then randomized to flucloxacillin versus placebo. No significant difference in wound infection rates was found (3%, and 4%, respectively; P > .05).7 Low-risk open tuft fractures require meticulous wound care, followed by reduction, primary closure, and a volar digital splint. High-risk open tuft fractures may benefit from prophylactic antibiotics.
Middle and Proximal Phalanx
Middle and proximal phalanx fractures are relatively more susceptible to rotational forces. Physical examination should identify rotational deformity (eg, scissoring of the digits with flexion), tendon injury, and open fracture. Two-view radiographs are recommended.
Displaced fractures require digital nerve block, closed reduction, and splinting. Proximal phalanx fractures in digits 2 and 3 require a radial gutter splint, while digits 4 and 5 require an ulnar gutter splint. Following splint application, all patients require neurovascular reassessment and confirmatory post-reduction radiographs. All patients with these injuries should be referred to a hand surgeon.
Emergent hand surgery consultation is recommended for non-tuft open phalangeal fractures. The inability to reduce the fracture fragment, >10° angulation, 2 mm shortening, any rotational deformity, and intra-articular fractures with involvement of >30% of the articular surface require either hand surgeon consultation or urgent referral.8
Fractures of Metacarpals 2, 3, 4, 5
Fractures of metacarpals 2, 3, 4, and 5 are classified into 4 categories: (1) base, (2) shaft, (3) neck, and (4) head fractures. Physical examination should identify rotational deformity, fight bite injury, neurovascular injury, compartment syndrome, and open fracture. Three-view radiographs of the hand are recommended.6
Metacarpal base fractures are uncommon and usually result from axial loading on the metacarpal due to a fall with the elbow extended.9 Displaced closed metacarpal base fractures require reduction, splinting, and referral.
Metacarpal shaft fractures may result from closed-fist injury or high-energy impact injury. Displaced closed metacarpal shaft fractures require adequate reduction, splinting, and referral.
A radial gutter splint is recommended for fractures of metacarpals 2 and 3, and an ulnar gutter splint is recommended for fractures of metacarpals 4 and 5. The hand should be immobilized in the intrinsic plus position. Analgesia during closed reduction may be achieved with a fracture hematoma block. All patients undergoing closed reduction require splinting, neurovascular assessment, and confirmatory post-reduction radiographs.
Metacarpal head fractures are rare. They are usually comminuted and associated with significant cartilage and/or joint disruption.
Boxer’s Fracture
The most common mechanism of metacarpal neck fracture is closed-fist injury. A boxer’s fracture is a fifth metacarpal neck fracture, and it accounts for 20% of hand fractures.10 Closed reduction of a metacarpal neck fracture is achieved via the Jahss maneuver11 or the 90-90 maneuver. Although a 2005 Cochrane review meta-analysis reported that there is insufficient evidence to demonstrate superiority between various splinting techniques for closed boxer’s fracture, ulnar gutter splints are commonly applied.12 As with rotationally deformed proximal and middle phalanx fractures, metacarpal neck fractures associated with rotational deformity also need urgent hand surgeon evaluation/referral.
Following splint application, all patients require neurovascular reassessment and confirmatory post-reduction radiographs. All patients should be referred to a hand surgeon. Patients with suspected occult fracture should be splinted and referred to a hand surgeon. Emergent consultation with a hand surgeon is recommended for open fracture, associated fight bite injury, inability to reduce the fracture, and any rotational deformity.13
Thumb Fractures
Thumb fractures are classified into 3 categories: (1) phalangeal, (2) metacarpal, (3) and intra-articular metacarpal base fractures. Physical examination should identify point tenderness, rotational deformity, and open fracture. Dedicated thumb radiographs are recommended. When diagnostic uncertainty persists despite normal radiographs, a Roberts view (i.e., true anterior-posterior thumb view) may be considered.
Phalangeal and Metacarpal Shaft Fractures
Closed transverse thumb phalanx and metacarpal shaft fractures require closed reduction, thumb spica splinting, and referral. Indications for emergent hand surgery consultation include open fracture, inability to reduce the fracture, >30° angulation, and any rotational deformity.14
Intra-Articular Fractures of the Thumb Metacarpal Base: Bennett and Rolando Fractures
The most common mechanism of intra-articular fractures of the base of the thumb is axial loading. A Bennett fracture is a 2-part intra-articular fracture dislocation or subluxation of the base of the thumb metacarpal. A Rolando fracture is a Y-shaped comminuted fracture dislocation of the base of the thumb metacarpal.14
Bennett and Rolando fractures are associated with a high risk of degenerative joint disease and functional limitation at the first carpometacarpal joint. Fracture reduction is achieved via axial traction, opposition of the thumb metacarpal joint, and radial pressure over the metacarpal base. Patients require a thumb spica splint. Following splint application, all patients require neurovascular reassessment and confirmatory post reduction radiographs. All patients should be referred to a hand surgeon.14-18 Patients with suspected occult fracture should be splinted and referred to a hand surgeon.
Scaphoid Fracture
Scaphoid fracture most commonly occurs following a FOOSH injury. Complications of scaphoid fracture include avascular necrosis and scapholunate advanced collapse. These sequelae can be functionally devastating. Physical examination should identify anatomical snuffbox tenderness and tenderness with axial loading of the thumb. A 2014 meta-analysis by Carpenter et al demonstrated that the absence of snuffbox tenderness signals the lowest negative likelihood ratio of any physical examination maneuver for scaphoid fracture (odds ratio, 0.15; 95% confidence interval, 0.05-0.43).19
Wrist radiographs, including a dedicated scaphoid view, are recommended. Plain radiographs are not adequately sensitive to exclude scaphoid fracture. Initial radiographs may be normal in up to 20% of cases.6
A randomized prospective trial by Clay et al of 392 patients with scaphoid wrist fractures compared thumb spica splinting and volar wrist splinting. The authors reported no significant difference in nonunion rates (10% for both groups), but 100 patients were lost to follow-up.20 Application of a thumb spica splint is recommended. In patients with suspected occult scaphoid fracture despite normal radiographs, splinting and referral to a hand surgeon is recommended. Radiographs are repeated in 10 to 14 days.6
Risk Management Pitfalls in Hand Injuries
1.“The patient seemed to be in a lot of pain following the crush injury. Later, she began to complain of worsening pain and then complained of numbness and tingling. It’s normal for a crush injury to hurt.” Pain out of proportion to the injury is an early clinical sign of possible compartment syndrome. Repeat focused hand examination should include palpation for tense, swollen hand compartments, eliciting severe tenderness on passive stretching of compartments, finding impaired sensory function (including 2-point discrimination), and looking for evidence of impaired perfusion. Emergent consultation with hand surgery is critical.
2.“I gave cefoxitin for an acute, clean, open distal tuft fracture and consulted a hand surgeon for operative wash-out, intravenous antibiotics, and admission.” Parenteral antibiotics are not indicated for low-risk open distal tuft fractures. Patients require analgesia, meticulous wound care, reduction, splinting, and referral to a hand surgeon.
3.“A patient with wrist pain after a FOOSH injury had point tenderness over the lunate and severely impaired wrist range of motion. No anatomical snuffbox tenderness was noted. Anterior-posterior, lateral, oblique, and navicular view radiographs showed 2 mm scapholunate diastasis. Since no fracture was present on radiographs, I diagnosed the patient with a wrist sprain. The patient was discharged home with rest, ice, compression wrap, NSAIDs and primary care follow-up.” Patients with suspected scapholunate instability require thumb spica splinting and outpatient referral to hand surgery.
4.“In a patient with mallet finger, I buddy-taped the affected digit to the adjacent digit to immobilize it.” Mallet finger requires limited splinting of the DIP alone, in extension, for six to eight weeks and referral to a hand surgeon.
5.“A patient with high-pressure injection injury of an unknown substance had no symptoms. Following routine wound care and tetanus vaccination, I discharged him home with a referral to primary care.” Early high-pressure injection injury often appears clinically innocuous. The injected material tracks along neurovascular bundles along the path of least resistance. These injuries are associated with a high rate of infection, necrosis, and considerable amputation risk. All patients should receive intravenous antibiotics and immediate hand surgery consultation for operating room wound exploration and admission.
6.“The patient presented with a grossly contaminated laceration overlying the hypothenar eminence. Wound exploration revealed no complicating soft-tissue injuries. Tissue debridement was required to remove organic plant debris. Radiography did not reveal retained foreign body or fracture. I closed the laceration with simple interrupted sutures and the patient was instructed to see his primary care doctor in 14 days for suture removal.” Wounds at moderate to high risk of infection should receive prophylactic antibiotics. Primary closure is not recommended for high-risk wounds, but they may be considered for delayed primary closure. For primarily repaired wounds at moderate risk of infection, a scheduled recheck at 2 to 3 days can also be a useful strategy.
7.“I could not stop the bleeding with direct pressure, so I placed a figure-of-eight suture.” Figure-of-eight suture, or blind clamping of bleeding vessels, should be avoided due to possible injury to adjacent structures. Hemorrhage control should be managed with focal direct pressure and limb elevation. Temporary tourniquet placement should be considered if significant bleeding persists.
8.“Despite multiple attempts, I was unable to reduce a fourth proximal phalanx oblique shaft fracture, and 15° of rotational deformity and 20° of angulation persists. I buddy-taped the affected digit and discharged the patient with instructions to follow up with a hand surgeon.” Inability to achieve reduction goals (in this case, 0° rotational deformity and <10° angulation) requires immediate hand surgery consultation for closed reduction or possible open reduction. This patient should also have been placed in an ulnar gutter splint and not buddy taped.
9. “The patient with a laceration overlying a joint was unable to move the joint through full range of motion due to pain during wound exploration, but I did not see any evidence of tendon injury.” Complete examination through full range of motion is required to assess for tendon injury because the injured tendon may be retracted in the neutral position. Regional nerve block or digital nerve block is often necessary to permit full range of motion during wound exploration. If diagnostic uncertainty persists, splint and refer.
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References
Excerpted from: Evidence-Based Management of Acute Hand Injuries in Urgent Care
Evidence-Based Urgent Care. 2023 February;2(2):1-26. Reprinted with permission of EB Medicine. Learn more about Evidence-Based Urgent Care and get a free sample issue at https://www.ebmedicine.net/urgent-care-info