|
 |
|
Sign In to gain access to subscriptions and/or personal tools.
|
First published on September 16, 2005, doi:10.1177/0363546505278298
This version was published on January
1, 2006
The American Journal of Sports Medicine 34:29-31 (2006)
© 2006 American Orthopaedic Society for Sports Medicine
Locked Metacarpophalangeal Joint in a 20-Year-Old Football Player
A Case Report
Richard J. Thomas, MD*,
,
Michael E. Pannunzio, MD,
,
Mark D. Miller, MD and
A. Bobby Chhabra, MD,
From the Department of Orthopaedic Surgery and the University of Virginia Hand Center, University of Virginia Health Sciences Center, Charlottesville, Virginia
* Address correspondence to Richard J. Thomas, MD, 665 Lockesley Terrace, Charlottesville, VA 22903 (e-mail: rthomasmd27{at}hotmail.com).
Key Words: locked metacarpophalangeal joint • trigger finger • hand • stenosing flexor tenosynovitis
 |
INTRODUCTION
|
|---|
Locking or catching of the fingers in the flexed position is a common occurrence when caused by stenosing flexor tenosynovitis or "trigger finger" (Figure 1
). A far less common problem is the locked metacarpophalangeal (MP) joint. This diagnosis was first described by Langenskiold,13 who reported the cause as radial collateral ligament entrapment by the metacarpal head (Figure 2). Other causes for locking of the MP joint have been described, such as volar metacarpal head osteophytes impinging on the collateral ligaments or palmar plate,2,9 entrapment of a sesamoid bone in the MP joint,3,8 irregularities of the articular surfaces of the MP joint,6,7 tears of the collateral ligaments or palmar plate,1,16 intra-articular loose bodies,11 abnormal soft tissue bands around the joint,4 and entrapment of the first dorsal interosseous tendon on an exostosis of the metacarpal head.5 We describe a 20-year-old football player who was believed to have a trigger finger and was later found to have a locking MP joint of his index finger caused by a prominent radial ridge of the metacarpal head entrapping the accessory collateral ligament.
View larger version (26K):
[in this window]
[in a new window]
|
Figure 2. Locked metacarpophalangeal joint secondary to radial collateral ligament (RCL) caught under prominent radial condyle of metacarpal.
|
|
|
CASE REPORT
|
|---|
A 20-year-old right-hand-dominant male Division I college football player was seen with acute onset of pain in his left index finger in the region of his A1 pulley. The patient described a sudden "pop" in his index finger while weight lifting, with the acute inability to extend his MP joint past 40°. He had had similar intermittent "catching" of this finger during the previous 6 months, but at no previous time had he not been able to fully extend his finger until this episode.
The patient was examined by the senior author (A.B.C.) and on examination was found to have a mechanical block to extension of his index finger past 40° actively or passively. He was tender just proximal to the region of the A1 pulley and had minimal tenderness over the dorsum of his finger over his extensor hood and sagittal bands. Attempts at closed manipulation failed. Radiograph results were essentially negative, without any signs of fracture or dislocation.
A decision was made to take the patient to the operating room for A1 pulley release of his index finger for a presumed locked trigger finger. The A1 pulley was released under direct vision using a palmar incision over the pulley. No abnormalities were noted in the A1 pulley or along the flexor tendon. The tendon was free of nodules. After the release, the finger was manipulated, and the mechanical block resolved. The index finger had full range of motion after manipulation. The MP joint was not explored at this time.
The patient had no other complaints for 6 months after his A1 pulley release and no recurrence of his locking. However, while doing dumbbell biceps curls, he had a recurrence of the locking of his index MP joint. This episode was similar to his initial occurrence. The MP joint of his index finger had a block to extension at 40° with full flexion and full range of motion of the interphalangeal joints. He had tenderness at the radial aspect of his MP joint and mild tenderness over the A1 pulley release. Again, radiograph findings were normal. Attempts at closed reduction manipulation failed, so the decision was made to take the patient back to the operating room to explore the MP joint.
With the patient under general anesthesia, a closed reduction was possible, although with some difficulty. A dorsoradial approach over the area of tenderness was then made at the level of the index finger MP joint (Figure 3). The interval between the extensor tendon and sagittal band was opened to expose the joint, and a bloody effusion was noted within the joint, possibly because of capsular injury from a forceful reduction. The radial condylar ridge of the metacarpal head was noted to be rather prominent, and it happened to be entrapping the accessory radial collateral ligament. The ligament was lifted off of the ridge, and full extension of the MP joint was possible. With ulnar deviation and flexion of the MP joint, it was possible to lock the accessory collateral ligament underneath the radial condylar ridge, and full extension of the MP joint was again impossible. After unlocking the MP joint, the prominence was excised using a rongeur, taking care not to injure the articular surface. The accessory collateral ligament was also excised. It was no longer possible to lock the MP joint after these 2 structures were excised, and the finger had full range of motion. The rest of the MP joint was explored, and no osteophytes or articular surface abnormalities were noted.
View larger version (25K):
[in this window]
[in a new window]
|
Figure 3. Surgical approach to treating locked metacar-pophalangeal joint. A rongeur is used to perform a "radial condylectomy" of the metacarpal to prevent locking of the radial collateral ligament (RCL) under the prominent metacarpal condyle.
|
|
At 2-year follow-up, the patient has remained asymptomatic and is a quarterback and wide receiver on a Division I football team at the current time.
|
DISCUSSION
|
|---|
Locked MP joints most commonly occur in the index and long fingers, with an equal occurrence in men and women.14 Harvey10 developed a classification system for locked MP joints that consisted of (1) spontaneous and (2) degenerative. Degenerative locked MP joints typically affect patients older than 50 years and most commonly involve the long finger. Osteophytes or degenerative changes in the joint capsule are commonly the cause of the locking. Spontaneous locked MP joints typically occur in patients younger than 50 years and affect the index finger. A history of trauma occasionally exists, but usually the cause of spontaneously locked MP joints is either a prominent metacarpal head or absence of the deep transverse metacarpal ligament radially, which predisposes the catching of the palmar plate on that side.
Although the cause of a degenerative locked MP joint can be explained by the development of osteophytes or degenerative changes in the capsule, the cause of spontaneous locked MP joints is less well understood. The patient in the case reported here is an athlete who participates in activities such as weight lifting and contact sports, which could possibly lead to a chronically stretched radial collateral ligament. It is interesting to note that the patient was weight lifting both times his MP joint locked. Curling dumbbells places a significant stress on the radial collateral ligament at the MP joint, possibly leading to increased laxity in the ligament. Ultimately, this effectively lengthened ligament could subluxate volarly under a prominent radial condyle, causing a locking phenomenon.
Treatment of the locked MP joint usually requires surgery, but closed manipulation has been described with moderate success.12,14,15 For closed treatment, most authors recommend injecting local anesthetic into the joint for both pain relief and joint distension followed by gentle traction with rotation and then gentle extension.12,14,15 If the joint does not reduce easily, surgical intervention is required. Langenskiold13 reported an intra-articular fracture secondary to a forceful closed manipulation attempt. Open treatment usually consists of either a palmer or midlateral approach in which the cause of the locking dictates the rest of the procedure. Most open procedures require resection of a prominence on the metacarpal head that is contributing to the locking.5,12,14,15
The locked MP joint can present a diagnostic dilemma. Trigger fingers are more common clinical entities and typically are at the top of the list in the differential diagnosis for a history of catching or locking of the digits. However, it is imperative to differentiate between a trigger finger and a locked MP joint because of their different causes and treatments.
One can differentiate between the 2 entities by certain clinical findings. A locked MP joint has little to no loss of motion in the interphalangeal joints. The MP joint has a mechanical block to extension to 30° to 45° but has no loss of flexion. Locked MP joints also tend to have a more sudden onset than does stenosing flexor tenosynovitis. Trigger finger has few symptoms in the MP joint. The loss of motion in a locked trigger finger is in the interphalangeal joints.14
In our case, the patient’s initial occurrence probably was not caused by stenosing flexor tenosynovitis but was in fact a locked MP joint caused by a prominent radial ridge of the index metacarpal entrapping the accessory collateral ligament. Although postoperative changes from the patient’s first surgery or a new injury could have caused the second episode of locking, the fact that his locking episodes were identical preoperatively and postoperatively seems to support the theory that the same abnormality was the culprit. For this reason, the A1 pulley release he underwent was not curative, and the patient had a recurrence of his locking. No pathologic changes, such as tendon nodularity or A1 pulley thickening, were found at the first surgery, hinting that stenosing flexor tenosynovitis was not the cause of the patient’s locking. Manipulation under anesthesia probably released the entrapped accessory collateral ligament, giving temporary resolution to the locked MP joint. This case report reinforces the fact that not all locking of the digits is caused by stenosing flexor tenosynovitis, and one must take into account the possibility of a less likely cause, such as a locked MP joint, particularly in a young person in whom trigger finger is a less common entity.
|
FOOTNOTES
|
|---|
No potential conflict of interest declared.
|
REFERENCES
|
|---|
- Alldred A. A locked index finger. J Bone Joint Surg Br. 1954;36:102–103.
- Aston JN. Locked middle finger. J Bone Joint Surg Br. 1960;42:75–79.
- Bloom MH, Bryan RS. Locked index finger caused by hyperflexion entrapment of sesamoid bone. J Bone Joint Surg Am. 1965;47:1383–1385.[Free Full Text]
- Bruner JM. Recurrent locking of the index finger due to internal derangement of the metacarpophalangeal joint. J Bone Joint Surg Am. 1961;43:450–452.[Free Full Text]
- Charendoff MD. Locking of the metacarpophalangeal joint: a case report. J Hand Surg. 1979;4:173–175.[Medline][Order article via Infotrieve]
- Dibbell DG, Field JH. Locking metacarpal phalangeal joint. Phys Roentgen Soc. 1967;40:562–564.
- Flatt AE. A locking little finger. J Bone Joint Surg. 1961;434:240–242.
- Flatt AE. Recurrent locking of an index finger. J Bone Joint Surg Am. 1958;40:1128–1130.[Free Full Text]
- Goodfellow JW, Weaver JPA. Locking of the metacarpophalangeal joints. J Bone Joint Surg Br. 1961;43:772–777.
- Harvey FJ. Locking of the metacarpophalangeal joints. J Bone Joint Surg Br. 1974;56:157–159.
- Honner R. Locking of the metacarpophalangeal joint from a loose body. J Bone Joint Surg Br. 1969;51:479–481.
- Inoue G, Miura T. Locked metacarpophalangeal joint of the finger. Orthop Rev. 1991;20:149–153.[Medline][Order article via Infotrieve]
- Langenskiold A. Habitual locking of a metacarpophalangeal joint caused by a collateral ligament, a rare cause of trigger finger. Acta Chir Scand. 1949;99:43.
- Posner MA, Langa V, Green, SM. The locked metacarpophalangeal joint: diagnosis and treatment. J Hand Surg Am. 1986;11:249–253.[Medline][Order article via Infotrieve]
- Rankin AR, Uwagie-Ero S. Locking of the metacarpophalangeal joint. J Hand Surg Am. 1986;11:868–871.[Medline][Order article via Infotrieve]
- Yancey HA, Howard LD. Locking of the metacarpophalangeal joint. J Bone Joint Surg Am. 1962;44:380–382.[Abstract/Free Full Text]
TOP
INTRODUCTION
CASE REPORT
