What is the treatment for a carpal boss at the third metacarpal?

Treatment of Carpal Boss at the Third Metacarpal

The treatment of carpal boss at the third metacarpal should begin with conservative management, including topical NSAIDs, oral NSAIDs at the lowest effective dose if needed, and activity modification, with surgical simple resection reserved for cases that fail conservative treatment. 1, 2

Initial Conservative Management

First-Line Treatment

• Topical NSAIDs: Apply diclofenac gel or similar topical NSAID directly to the affected area as first-line treatment 1
  • Provides localized pain relief with minimal systemic side effects
  • Particularly effective for superficial joints like those in the hand

Second-Line Treatment

• Oral NSAIDs: If topical treatment is insufficient, use oral NSAIDs at the lowest effective dose for the shortest duration 1
  • Monitor for gastrointestinal and cardiovascular side effects
  • Consider paracetamol (up to 4g/day) as an alternative if NSAIDs are contraindicated

Supportive Measures

• Activity modification: Avoid activities that aggravate symptoms 1, 3
• Orthoses/splinting: Consider night splinting for pain relief and daytime splinting during activities that worsen symptoms 1
• Hand exercises: Perform daily range-of-motion and strengthening exercises to maintain function and reduce stiffness 1

Advanced Conservative Management

Corticosteroid Injections

• Consider intra-articular corticosteroid injections for acute painful flares with clear signs of inflammation 1
• Use a small needle (25-27 gauge) with 5-10mg triamcinolone acetonide 1
• Limit frequency to avoid potential cartilage damage

Surgical Management

Indications for Surgery

• Persistent pain despite adequate trial of conservative management
• Functional limitations that severely affect daily activities
• Significant impact on quality of life 1, 2

Surgical Technique

• Simple exostosis resection is the preferred surgical approach for carpal boss 2
  • Shown to be effective with high patient satisfaction (60% very satisfied, 40% satisfied) in a study with 8-year follow-up
  • No cases of recurrence in the study of 25 patients
  • 96% of patients considered themselves cured (60%) or improved (36%)

Surgical Considerations

• Avoid excessive bone resection to prevent metacarpal instability 2
• Fusion should be reserved only for rare cases of secondary metacarpal instability 2
• Be aware that features of dysplasia and secondary osteoarthritis limited to the area of impingement are common findings 2

Post-Treatment Follow-up

• Assess treatment effectiveness with more frequent monitoring initially
• Decrease follow-up frequency once symptoms stabilize 1
• Monitor for potential complications:
  • With conservative management: persistent pain, functional limitations
  • With surgical management: potential for carpometacarpal instability (rare, 1 case out of 25 in the study) 2

Clinical Pearls and Pitfalls

• Carpal boss is often misdiagnosed as a ganglion cyst 4
• The majority of wrists (82.2%) demonstrate an isolated protuberance arising from the dorsal base of the third metacarpal 5
• Secondary arthritis at the pseudoarticulation may be present in some cases (6.2%) and can be a source of pain 5
• Conservative management allowed return to play in two weeks without restrictions in an elite hockey player with traumatic onset of symptomatic carpal boss 3

The evidence strongly supports starting with conservative management for carpal boss, with surgical intervention reserved for cases that fail to respond to non-operative treatment. Simple resection has shown excellent long-term results when surgery becomes necessary.