Codman (1905) — The Diagnosis and Treatment of Fracture of the Carpal Scaphoid and Dislocation of the Semilunar Bone: With a Report of Thirty Cases. Part II. Dislocation of the Semilunar Bone with or without Fracture of the Carpal Scaphoid.

The Diagnosis and Treatment of Fracture of the Carpal Scaphoid and Dislocation of the Semilunar Bone: with a Report of Thirty Cases. Part II. Dislocation of the Semilunar Bone with or without Fracture of the Carpal Scaphoid.

Codman, Chase·Ann Surg·1905·15 citations·Trauma

Summary

Codman and Chase report twelve cases of anterior (volar) lunate dislocation, with or without scaphoid fracture. They describe the injury mechanism, clinical presentation, and reduction technique. The series compares outcomes across closed reduction, open reduction, and excision at varying times after injury.

Study Snapshot

Design

Retrospective case series

Blinding: Open-label

Setting: Massachusetts General Hospital, Boston

Outcome(s)

Wrist function and motion after various treatments

Subjects

12 cases of lunate dislocation

Closed (bloodless) reduction
Open reduction via palmar incision
Excision of lunate and/or scaphoid fragment

Inclusion

Anterior dislocation of the lunate
With or without scaphoid fracture

Follow-up

Variable, months to several years

Key Findings

Volar lunate dislocation is caused by forced hyperextension, which tears the posterior horn ligaments and squeezes the lunate forward. Because the mechanism is hyperextension, reduction must be by hyperflexion: hyperextend first to seat the lunate on the radius, then use thumb pressure while an assistant flexes the wrist.
The injury classically produces a palmar tumor beneath the flexor tendons that compresses the median nerve, causing pain and numbness in the median distribution. This palmar prominence, plus a dorsal os magnum bump, creates a silver-fork appearance easily mistaken for Colles fracture.
Nearly every case was initially misdiagnosed as Colles fracture or sprain. The authors insist the X-ray is the only reliable way to confirm the dislocation and to detect an associated displaced scaphoid fragment.
Closed reduction succeeded even over a month after injury and gave near-perfect results (Cases 9 and 10). This supports attempting bloodless reduction before any open procedure, even with significant delay.
When lunate dislocation combines with a displaced fractured scaphoid and closed reduction fails, excising both the lunate and the scaphoid fragment (Case 11) gave better motion than excising only the fragment and reducing the lunate (Case 8).
The volarly dislocated lunate must be reached through an anterior incision between the flexor tendons. The dorsal approach used for scaphoid excision cannot access it.
A scaphoid fragment excised at 7 weeks showed almost no healing, only a thin fibrous layer over the trabeculae, illustrating the poor union tendency of the proximal fragment.
All 12 patients were male, mostly aged 20 to 50, injured by high-energy falls and occupational trauma.

Board PearlVolar lunate dislocation results from hyperextension and is reduced by hyperflexion; it mimics Colles fracture and demands X-ray for diagnosis.

Clinical Relevance

When a working-age man presents after a high-energy fall with a stiff, painful wrist, a silver-fork deformity, and median nerve symptoms, do not stop at the diagnosis of Colles fracture. Get the X-ray and look specifically for a volarly displaced lunate and a scaphoid fragment.

The mechanism is the key teaching point. Hyperextension drives the lunate volar, so reduction reverses it: hyperextend to seat the lunate, then hyperflex under thumb pressure. This paper's algorithm still maps onto modern practice. Attempt closed reduction early, even weeks out, because delayed reduction here still produced excellent results.

Recognize that the proximal scaphoid heals poorly, shown by the near-absent repair at 7 weeks. This foreshadows the modern concern for scaphoid nonunion and proximal-pole avascular necrosis. Approach the volar lunate anteriorly. A dorsal incision will not reach it.

Supplemental

The Diagnosis and Treatment of Fracture of the Carpal Scaphoid and Dislocation of the Semilunar Bone: with a Report of Thirty Cases. Part II. Dislocation of the Semilunar Bone with or without Fracture of the Carpal Scaphoid.

The Diagnosis and Treatment of Fracture of the Carpal Scaphoid and Dislocation of the Semilunar Bone: with a Report of Thirty Cases. Part II. Dislocation of the Semilunar Bone with or without Fracture of the Carpal Scaphoid.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles

The Diagnosis and Treatment of Fracture of the Carpal Scaphoid and Dislocation of the Semilunar Bone: with a Report of Thirty Cases. Part II. Dislocation of the Semilunar Bone with or without Fracture of the Carpal Scaphoid.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles

The Diagnosis and Treatment of Fracture of the Carpal Scaphoid and Dislocation of the Semilunar Bone: with a Report of Thirty Cases. Part II. Dislocation of the Semilunar Bone with or without Fracture of the Carpal Scaphoid.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles

The Diagnosis and Treatment of Fracture of the Carpal Scaphoid and Dislocation of the Semilunar Bone: with a Report of Thirty Cases. Part II. Dislocation of the Semilunar Bone with or without Fracture of the Carpal Scaphoid.

Study Snapshot

Key Findings

Clinical Relevance

Related Articles