A jammed finger is a popularly used term that refers to injuries around the proximal interphalangeal joint of the fingers. The term is not specific to a single injury but rather describes a group of injuries that are related to varying degrees of loading across the proximal interphalangeal joint due to jamming of the finger between two closeable opposing surfaces, most often in the doors.
A jammed finger is a very common injury in sportspersons especially in ball sports where the ball can hit the finger when the player attempts to catch it.
Relevant Anatomy
The proximal interphalangeal joint is a hinge joint between proximal and distal phalanges of the finger. Its range of motion is from 0-120 degrees.
Collateral ligaments provide lateral stability and restrict the lateral motion in the proximal interphalangeal joint.
The volar plate separates the joint space from the flexor tendons. The volar plate is a ligamentocartilaginous structure that has ligamentous origin on the proximal phalanx and cartilaginous insertion onto the middle phalanx.
On extensor side, the extensor tendon divides into one central slip and two lateral slips. The central slip passes directly over the joint and inserts on the base of the middle phalanx.
The presence of the volar plate limits the extension beyond zero degrees.
Dorsal stabilization is done by the central slip of the extensor tendon acts to stabilize the joint and to extend the middle phalanx. The lateral bands, also contribute to joint stability.
Injury to the PIP joint is common in sports especially ball-handling sports.
Injuries to the proximal interphalangeal joint can cause permanent disability if missed or mistreated.
The common mechanism of injury is simultaneous application of hyperextension forces with some degree of longitudinal compression.
What are the injuries that term Jammed Finger may Suggest?
[read more about phalanx injuries]
As we noted before jammed finger may mean a cluster of different kinds of injuries. These injuries commonly include
Volar Plate Injury
A volar plate injury can occur when rupture occurs at its distal insertion on the middle phalanx. Because the joint is intact, it is a stable injury.
Local pain and swelling occur but the x-rays are normal.
Sometimes, the fracture of middle phalanx may occur where the volar plate is attached. This is an articular fracture and treated accordingly.
Dislocation of proximal interphalangeal joint
Usually, the dislocation is dorsal and may rupture volar plate as well which can interpose between joint surfaces and resist the reduction. Collateral ligaments are injured as well in such cases.
However, dislocations may occur without volar plate rupture and these would be easily reducible.
Intraarticular fractures of the base of middle phalanx are often unstable injuries and may be associated with subluxation or dislocation.
Injury to Collateral Ligaments
Bending forces may cause injury to a collateral ligament, Depending on the force, the degree of sprain would vary.
The injury often heals by scar tissue formation and often result in these injuries often result in the fatty appearance of the knuckle, also termed as a fat knuckle.
Apart from this, recovery is good.
Boutonniere deformity
It is a flexion deformity of PIP joint where the head of proximal phalanx becomes more prominent dorsally.
There is a disruption of the central slip of the extensor tendon at its insertion on the middle phalanx. The lateral slips separate and the head of the proximal phalanx comes out to a dorsal position like a finger through a buttonhole.
The deformity may not be present when the injury occurs and may develop gradually over a period
There is flexion of PIP joint flexion and distal interphalangeal and there is a hyperextension of distal IP joint.
Causes
Jammed fingers are common in sports basketball, baseball, and volleyball where hand bears the impact of the ball. Other causes are
- Closing a drawer or door on the finger
- Finger stuck on the steering wheel during an automobile accident
- Other movements/forces Any action that puts extra strain on the PIP joint.
Symptoms
A jammed finger would have the following symptoms. The severity of the symptoms would depend on the severity of the symptoms.
- Redness and swelling
- Difficulty moving the finger
- Pain
Differential Diagnosis
• Gamekeeper’s Thumb
• Mallet Finger
• Phalangeal Fractures
• Skier’s Thumb
Diagnosis
Lab studies are not required for diagnosis. Anteroposterior, lateral, and oblique radiographs of the injured digit are used for reaching at the specific diagnosis.
Treatment of Jammed Finger
Initial treatment or Home remedies
A minor jammed finger can be cared for by protection and RICE therapy, also called PRICE therapy.
- P – Protection. Generally done by splinting. Splinting or buddy wrapping will help.
- R – Rest. Resting and avoiding activity
- I- Ice. Application of ice-pack reduces inflammation. Ice is applied intermittently for 10–15 minutes at a time
- C- Compression. Achieved by splinting
- E- Elevation. Can be achieved by placing the hand on a pillow.
All serious injuries or severley painful injuries should be taken for medical consultation within a reasonable time period after injury.
Open injuries and injuries where the finger is numb or pale should seek emergency medical assistance.
Following reasons are enough to seek doctor’s advice even if the injury appears minor.
- Deformed finger
- Fever after injury
- Increase in swelling in spite of PRICE
- Increase in pain
An untreated jammed finger can lead to complications like deformity or stiffness.
Definitive Treatment
Most of the jammed finger injuries could be treated with nonoperative treatment. Operative treatment is needed for joint injuries and injuries not amenable to closed treatment.
- For volar plate sprain, simple buddy taping or buddy wrapping for 1-2 weeks suffice.
- Simple dislocations without volar plate entrapment can be reduced closed and then splinted with the joint in slight flexion.
- Dorsal dislocations with volar plate entrapment, open reduction, and K-wire fixation is required.
- Volar plate injuries with fracture of base of middle phalanx are treated as dislocations and often require K-wire fixation due to instability.
- Collateral ligament injuries can be very well treated with buddy splinting with taping to the digit on the side of the injury. Special splints may be given when an adjacent digit is not available. Grossly unstable collateral ligament injuries may be considered for surgical repair.
- For Boutonniere deformity, the finger is splinted in full extension for six weeks, followed by a range of motion exercises.
- All fracture dislocations which are irreducible, unstable or involve large portions of the articular surface should be fixed
References
- Freiberg A, Pollard BA, Macdonald MR, Duncan MJ. Management of proximal interphalangeal joint injuries. Hand Clin. 2006 Aug. 22(3):235-42.
- Caggiano NM, Harper CM, Rozental TD. Management of Proximal Interphalangeal Joint Fracture Dislocations. Hand Clin. 2018 May. 34 (2):149-165.
- Kamnerdnakta S, Huetteman HE, Chung KC. Complications of Proximal Interphalangeal Joint Injuries: Prevention and Treatment. Hand Clin. 2018 May. 34 (2):267-288
- Prucz RB, Friedrich JB. Finger joint injuries. Clin Sports Med. 2015 Jan. 34 (1):99-116
