What type of splint is recommended for a spiral 5th metacarpal fracture?

Splint Type for Spiral 5th Metacarpal Fracture

A hand-based functional splint (also called functional metacarpal splint) is the recommended treatment for spiral 5th metacarpal fractures, as it provides adequate fracture stability while allowing metacarpophalangeal (MCP), interphalangeal (IP), and wrist motion, resulting in faster functional recovery and earlier return to activities compared to traditional ulnar gutter splinting. 1, 2

Splint Selection and Rationale

Hand-Based Functional Splint (Preferred)

• The functional metacarpal splint immobilizes only the fracture site while permitting MCP joint, IP joint, and radiocarpal joint motion throughout treatment 1
• This approach maintains functional motion during the healing period, preventing the stiffness that commonly complicates metacarpal fractures 3
• A 2023 study of 39 metacarpal fractures demonstrated excellent maintenance of fracture reduction with hand-based splinting, with 27 of 30 patients showing no change in alignment from start to end of treatment 1
• Patients treated with functional splints achieve expected grip strength by 2 months, significantly faster than those treated with ulnar gutter splints 2
• Twenty out of 24 employed patients were able to continue working without missing any days when treated with hand-based functional splinting 1

Comparison to Ulnar Gutter Splint

• While ulnar gutter splints have been traditionally used, they restrict more joints unnecessarily and delay functional recovery 2
• A 2019 prospective comparative study found that functional metacarpal splints yielded significant improvement in QuickDASH scores between 2nd and 6th month follow-up (p=0.003), while ulnar gutter splints did not show significant improvement (p=0.075) 2
• Functional taping (similar concept to functional splinting) demonstrated significantly earlier functional recovery compared to cast immobilization in a randomized trial of 5th metacarpal fractures 4
• By 6 months, both splint types show similar radiological and clinical outcomes, but the functional splint provides faster recovery and better patient compliance due to less joint restriction 2

Application Principles

Initial Management

• Perform standard 3-view radiographic examination to confirm alignment before splint application 5, 3
• The splint should immobilize the fracture site while specifically allowing finger motion to prevent stiffness 3
• For spiral fractures specifically, ensure rotational alignment is corrected, as rotation is a critical factor that may require surgical intervention if impaired 6

Duration and Follow-up

• Average splint duration is approximately 24 days (range 3-4 weeks) 1, 7
• Radiographic follow-up at approximately 3 weeks to confirm adequate healing 3, 7
• Additional imaging at cessation of immobilization 5, 7

Critical Decision Points

When Conservative Splinting is Appropriate

• Non-displaced or minimally displaced fractures 1
• Fractures with acceptable angulation (generally <45° for 5th metacarpal neck fractures) 6
• Stable fracture patterns without significant rotational deformity 2

Red Flags Requiring Surgical Consideration

• Displacement >3mm, dorsal tilt >10°, or significant intra-articular involvement warrant surgical evaluation rather than splinting alone 5, 8
• Rotational malalignment that cannot be adequately corrected with closed reduction 6
• Inherently unstable fracture patterns at the base of the 5th metacarpal 9

Rehabilitation Protocol

• Active finger motion exercises for non-immobilized joints should begin immediately following diagnosis to prevent stiffness 3, 7
• Finger motion does not adversely affect adequately stabilized metacarpal fractures 3
• Joint stiffness is one of the most functionally disabling complications and can be minimized with early appropriate motion 8

Common Pitfalls to Avoid

• Over-immobilization: Restricting joints unnecessarily (MCP, IP, wrist) leads to preventable stiffness and delayed return to function 1, 2
• Inadequate initial reduction: Loss of reduction occurs more commonly in the first month, so ensure adequate initial alignment 2
• Immobilization-related complications occur in approximately 14.7% of cases and include skin irritation and muscle atrophy 8, 7