Treatment of Probable Intra-Articular Fracture at Base of First Metacarpal
For a probable intra-articular fracture at the base of the first metacarpal, obtain CT imaging without IV contrast to confirm the diagnosis and characterize the fracture pattern, then proceed with open reduction and internal fixation (ORIF) if displacement exceeds 1 mm to achieve anatomic reduction and optimize functional outcomes.
Initial Diagnostic Approach
When radiographs are equivocal but clinical suspicion remains high for an intra-articular first metacarpal base fracture:
- CT without IV contrast should be obtained to confirm the fracture and evaluate intra-articular extension and displacement 1
- CT is particularly useful for carpometacarpal joint fracture dislocations that are difficult to recognize on plain radiographs 1
- Three-dimensional reconstructions can be helpful in preoperative planning for complex articular injuries 1
- Standard thumb radiographs include 2 views (PA and lateral), though adding an oblique projection slightly increases diagnostic yield 1
Avoid the pitfall of placing the patient in a cast for 10-14 days to repeat radiographs, as this delays diagnosis and may lead to functional impairment 1
Treatment Algorithm Based on Fracture Characteristics
Surgical Indications (ORIF Preferred)
The goal for intra-articular fractures is anatomic reduction with less than 1 mm of articular step-off to minimize long-term risk of posttraumatic arthritis 2
Proceed with ORIF when:
- Articular displacement >1 mm is present 3
- Articular step-off or gap >1 mm is documented 2
- Large Bennett fragment is identified 2
- Rolando fracture pattern is present 2
Surgical Technique Selection
- ORIF provides superior anatomic reduction and functional recovery compared to closed reduction with percutaneous pinning 4
- A volar approach offers excellent visualization of the first metacarpal articular surface and allows ulnar-to-radial screw placement during thumb supination 3
- For Bennett fractures with large fragments, ORIF allows anatomic reduction with rigid fixation and early range of motion 2
- Fixation can be achieved with micro-screws or K-wires placed from ulnar to radial 3
Conservative Management (Limited Role)
- Closed reduction with percutaneous K-wire fixation may be considered for Bennett fractures, though ORIF demonstrates better outcomes 2
- Extra-articular metaphyseal fractures can exceptionally be treated conservatively with immobilization 5
- Angulation up to 30 degrees can be tolerated in extra-articular fractures due to compensatory motion at the carpometacarpal joint 2
Post-Operative Management
- Early active motion exercises should be initiated as soon as stability allows to prevent stiffness 6
- Radiographic follow-up at approximately 3 weeks and at time of hardware removal to confirm adequate healing 7
- Immobilization type depends on surgical fixation method and can be removable or non-removable 5
Expected Outcomes and Evidence Quality
The evidence strongly supports ORIF for displaced intra-articular fractures:
- ORIF results in better restoration of joint configuration and superior thumb opposition compared to extrafocal pinning 4
- Anatomical reduction was achieved in 100% of cases using the volar approach in one series 3
- Good functional results are possible even with some residual deformity in Bennett fractures, though anatomic reduction remains the goal 2
- Radiological arthrosis may develop in 64% of cases at follow-up, but this does not necessarily correlate with functional impairment 8
Critical Pitfalls to Avoid
- Do not accept articular step-off >1 mm, as this increases risk of posttraumatic arthritis 2
- Avoid conservative management with simple splinting for displaced intra-articular fractures, as this leads to poor outcomes 6
- Do not rely solely on plain radiographs when they are equivocal—obtain CT to avoid missed diagnosis 1
- Avoid excessive immobilization, which increases stiffness risk 6
- Monitor closely for secondary displacement, particularly in the first 3 weeks 3