Finger injuries: basics and bones

Injuries to the hand are frequent in the paediatric population and are a common reason for presentation to the PED. Despite the frequency of these presentations, their assessment and management can be challenging. But never fear! DFTB has come to the rescue with a comprehensive two-part series related to the assessment and management of paediatric hand and finger injuries, including some handy tips.

This post will cover the basic anatomy of the hand, some professional lingo, and a look at history taking and clinical examination.  

First, let’s look at the basic anatomy of the bones of the hand.

Professional lingo: Get to know your pinkie from your pointer!

Although it is helpful to know your pinkie from your pointer when talking to children, it is also important to understand the proper terms. This is important not only from a medico-legal point of view but also because having the ability to describe the exact location of clinical findings in professional terms makes communication and referral to specialist services much easier.

Clinical History/Documentation Essentials: Take a HAND history

H-          HOW the injury happened? Ask about the mechanism of injury, including the environment in which the injury was obtained.

              HOBBIES. Ask about the child’s hobbies, sports, activities, and career aspirations (in older children), as these may impact management.

A-          ALTERED sensations. Ask about altered sensations, such as paraesthesia which could indicate a nerve injury.

N-          NEEDLES/NEEDS TETANUS? Ask about vaccinations. Is the child’s Tetanus vaccination up to date, especially relevant if open wounds or animal/human bites are present?

NAI        Like all paediatric injuries, consider the possibility of NAI, especially in the younger child. A comprehensive history is essential to detect the possibility of intentional injury from physical abuse or an unintentional injury as a result of neglect. Consider injuries that are self-inflicted in the older child/adolescent age group.

D-          DOMINANCE. Ask and record the child’s hand dominance, which can impact injury management.

Physical exam – look, feel, move

Clinical assessment of hand injuries involves a systematic exam of both hands, including inspection, palpation, and range of motion (ROM).

Look

• Once the child has received appropriate analgesia and you have established a rapport with the child and their parent, begin by looking at the hand without touching it. Observe the child’s hand at rest and play. If available, involve a play specialist—they always bring the right amount of magic to get even the sorest of little hands and fingers moving!
• Look for bruising, swelling, abrasions or open wounds. Assess for nail bed injuries.
• Check for any clinical deformities, including a rotational deformity that may not become apparent until the child makes a fist. Minimally displaced fractures may be clinically significant if they result in a rotational deformity, so it is vital to routinely assess for them. Including the presence or absence of a rotational deformity in your documentation is good practice.

Feel

• Examine the child’s unaffected hand first and keep the child chatting throughout the exam. This will help reduce the child’s anxiety and allow the child to build trust in you.
• Remember to examine the whole hand. It is important to develop a systematic approach to hand examination, including palpation of the wrist, carpal bones (including the anatomical snuff box and scaphoid tubercle), metacarpals, metacarpophalangeal joints (MCPJs), phalanges, proximal interphalangeal joints (PIPJs), and distal interphalangeal joints (DIPJs). Systematic palpation of the entire hand can help localise underlying fractures and injuries.

• Evaluate and document neurovascular status.

Examination Pearl: The Wrinkle Test

Neurological assessment in young children or children/adolescents with difficulties communicating can be particularly challenging as they may be unable to report the presence or absence of sensation. The wrinkle test measures the autonomic function of peripheral nerves by placing the child’s hand in warm water for 10 minutes. Wrinkles on the fingers indicate intact neurological function.

Move

• Getting a child to move an injured hand can be challenging, but certain familiar gestures such as high fives, thumbs up or fist bumps can assess an active range of movement in a young or uncooperative child.
• A game of rock, paper, scissors is a fun and systematic way to test peripheral nerves in children with upper limb injuries. 
• Be vigilant for tendon injuries. Check out the DFTB finger tendon and ligament injuries post for further details and clinical pearls related to assessing specific tendon functions. These functional tests should be included in every clinical examination of an injured hand.

Phalangeal Fractures

Approximately 20% of hand injuries in children are fractures. The phalanges are the most frequently injured bones of the hand, with distal phalangeal and proximal phalangeal base fractures being the most commonly diagnosed fractures.

Proximal phalangeal base fractures

It’s a sunny June afternoon, and Patrick, a 9-year-old boy, is brought to your ED by his Dad.

It is the last day of school term before the summer holidays, and he tells you he was so excited that when the final bell rang, he threw his book bag in the air, but as it landed, his left little finger got caught in the strap.

It sounds like the weight of the bag forcefully abducted his finger. He shows you his swollen, bruised, and painful pinkie.  

Mechanism

Typically, proximal phalangeal base fractures result from a finger being abducted beyond the acceptable limits of the MCP joints.

Presentation

A child with a proximal base phalangeal fracture typically presents with swelling, ecchymosis, and focal tenderness on palpation to the base of the proximal phalanx. A displaced fracture to the base of the proximal phalanx can cause malrotation of the finger. A significantly displaced fracture or a fracture that causes a rotational deformity requires closed reduction to correct the deformity.

Imaging

Obtain oblique, PA, and lateral X-rays of the injured fingers. A true lateral X-ray is the most effective way to examine joint congruity. Angulation of proximal phalanx fractures is best seen on the lateral projection.

Salter-Harris Classification

The Salter-Harris Classification system describes fractures involving the physis as types I-V.  Salter-Harris type II fractures of the proximal phalanx are a common type of finger fracture in children.

• Salter-Harris type I fractures involve only the physis and can be difficult to diagnose because X-rays typically appear normal unless there is displacement.
• Salter-Harris type II fractures involve extension through the physis and metaphysis.
• Salter-Harris type III fractures extend through the physis and epiphysis.
• Salter-Harris type IV fractures extend through the physis, metaphysis and epiphysis.
• Salter-Harris type V fractures involve crush injuries that shatter the physis. 

Treatment

Non-Operative: Un-displaced or minimally displaced Salter-Harris type I or II fractures of the proximal phalanx without clinical deformity are usually managed with buddy taping to an adjacent finger for support and encouragement of early range of motion, typically for 3-4 weeks.

We often perform a closed reduction in ED for displaced Salter-Harris type II fractures of the proximal phalanx. Depending on the child’s age and preference, a closed reduction can be performed using a ring block with or without procedural sedation. The proximity of the physis assures a high degree of remodelling. The ED practitioner’s thumb or a cylindrical object, such as a pen or pencil, can be used to achieve adequate reduction. Post-reduction stability is maintained by buddy tapping +/—splinting.

Operative: Severely displaced, unstable or open fractures require evaluation by a hand surgeon.

X-ray shows a displaced Salter-Harris type II fracture to the base of Patrick’s proximal phalanx. There is a rotational deformity on the clinical exam.

You reduce the fracture in ED using a ring block and nitrous oxide.

On reassessment post-reduction, the clinical deformity is corrected, and the check X-rays are satisfactory. You discharge Patrick home with his finger buddy taped and arrange a follow-up in an outpatient clinic.  

Phalangeal shaft, neck and condylar fractures

Phalangeal shaft fractures

Treatment for fractures along the shaft of the phalanges is dictated by the orientation of the fracture and the degree of angulation on initial presentation. A clinical exam is also extremely important, as even innocuous-appearing fractures along the phalangeal shaft can be clinically significant if they cause a rotational deformity of the injured digit. A rotational deformity must be corrected, as failure to do so can lead to long-term functional impairments for the child.

Non-operative: For length stable fractures with minimal displacement, buddy taping to an adjacent finger for support and to allow early range of motion can be an effective treatment for approximately 3-4 weeks.

Operative: Oblique or spiral fractures requiring closed reduction need more rigid immobilisation, such as an ulnar or radial gutter splint or cast. Alignment of these fractures can be difficult to maintain, and fixation is often required; surgical opinion is advised.

Surgery is also indicated in cases of open or severely displaced fractures or where there is instability post-reduction.

Phalangeal neck fractures

Neck fractures of the proximal and middle phalanges are classic paediatric injuries, rarely seen in adults. They typically result from a crush injury to the finger, such as a child’s finger getting caught in a closing door.

Non-operative: Non-displaced fractures to the neck of the proximal or middle phalanges can usually be managed safely by immobilizing the digit for 3-4 weeks.

Operative: Surgical consultation is recommended for any displaced neck fractures as these are inherently unstable and require close follow-up.

Condylar fractures

The condyles are a pair of tuberosities that form the distal articular surfaces of the proximal and middle phalanges. Condylar fractures are intra-articular fractures and can be unstable. Therefore, surgical consultation is recommended, as these fractures require meticulous reduction to ensure proper joint congruity.

Volar plate avulsion injuries

Tori is a 14-year-old girl and a talented soccer goalie. She reports that while trying to save a penalty, her right middle finger was forcefully hyperextended and is now very painful. She shows you her right middle finger, which is swollen and bruised at the PIPJ.

What are volar plate injuries?

The volar plate lies between the flexor tendons and the palmar PIPJ capsule. It originates from the proximal phalanx and inserts into the middle phalanx. The volar plate contributes to the stability of the PIPJ by preventing hyperextension of the PIPJ.  Volar plate injuries encompass a spectrum of soft tissue injuries and can occur with an avulsion fracture at the volar base of the middle phalanx.  Subluxation or dislocation of the PIPJ may also occur.

Mechanism

Volar plate injuries are commonly caused by forced, sudden hyperextension injuries of the PIPJ, typically seen in older children and adolescents involved in hand/contact sports. Occasionally, a crush injury to the digit can cause volar plate injuries.

Presentation

The diagnosis of a volar plate injury is based on history and clinical examination. Typically, the PIPJ is swollen, and bruising to the volar surface is sometimes observed. Maximal tenderness on palpation is over the volar PIPJ, and the patients may report pain on passive hyperextension of the PIPJ. The collateral ligaments should be tested, as with collateral ligament injuries, to check the stability of the PIPJ.

X-rays may reveal an avulsion fracture at the base of the volar surface of the middle phalanx and can help identify PIPJ subluxation or dislocation.

Treatment

Non-operative: A stable joint without a large avulsion fracture (<40% of articular segment) and/or a reducible fracture with 30 degrees of flexion is usually managed conservatively with splinting. In less severe injuries, the injured finger can be buddy taped.

Operative: Surgical opinion should be sought if there is instability of the PIPJ or a large avulsion fracture.

When you examine Tori’s hand, you notice an isolated injury to Tori’s right middle finger, as evidenced by swelling, bruising, and tenderness to the PIPJ. Although active ROM is painful, Tori can fully extend and flex the finger.

X-ray demonstrates a small avulsion fracture to the volar base of the middle phalanx on her right middle finger, and you correctly diagnose her with a volar plate injury.

Tori’s injury is stable and suitable for buddy taping to allow for early range of motion and prevent stiffness.

Distal Phalangeal Fractures

Distal tuft fracture

Khalid is a 2-year-old boy. His mother brought him to the ED because he caught his right index finger in the hinge side of a closing door. You examine his hands and note swelling and erythema to the distal phalanx of his right index finger.

There is no nail bed injury or open wounds, and he is moving his finger freely as you observe him playing with a toy tractor that the PED play specialist kindly supplied.

His Mum appears more upset than he is, so you calmly reassure her that a serious finger injury is unlikely, but an X-ray is required to rule out a fracture.

Mechanism

Distal tuft fractures are common in the toddler or pre-school age groups and typically occur as a result of direct crush injuries such as getting little fingers caught in a closing door.

Presentation

A concomitant nail bed or pulp laceration may be present in children with a distal tuft fracture. In this case, the fracture is classed as an open fracture, and an opinion should be sought from the Plastic Surgery Team. Check out the DFTB post on fingertip injuries for more information related to the assessment and management of nail bed injuries. Be alert for injury to flexor/extensor tendons.

Treatment

Non-Operative: Most children with closed distal tuft fractures are treated conservatively with splinting or buddy taping.

Operative: Surgical treatment is reserved for patients with distal tuft fractures who have nail bed injuries, subtotal/total amputations, or an unstable transverse fracture pattern.

X-ray demonstrates an un-displaced tuft fracture.

You buddy tape Khalid’s fingers and reassure Mum that the fracture is small and unlikely to cause Khalid any functional problems.

Seymour fractures

Jordan is a 12-year-old boy who was brought to the PED with an injury to his left thumb. During a rugby match, he was tackled to the ground, and an opposition player stood on his thumb.

He shows you a swollen, bruised, partially flexed thumb. There is blood at the proximal nail fold, and the nail plate is partially avulsed. The finger is visibly contaminated with dirt and soil from the rugby pitch, so you irrigate it with saline prior to X-ray and check that Jordan’s vaccination status is up to date.

Mechanism

A Seymour fracture is an injury unique to children. This fracture pattern is usually caused by a crush injury and results in an angulated Salter-Harris type I or Salter-Harris type II fracture with an associated nail bed injury. It is important to recognise this fracture pattern as early referral to a hand surgeon is important to avoid complications.

Presentation

The typical presentation is a swollen, bruised, and painful finger flexed at the DIPJ. There may be blood under the nail, or the nail plate can be completely avulsed proximally, causing it to sit superficial to the eponynchial fold (aka proximal nail fold). Soft tissue (often the germinal matrix of the nail) can become interposed in the fracture, which prevents fracture reduction and healing.

Imaging

PA X-ray views of the injured finger often appear normal. Lateral view X-ray are used to confirm the diagnosis.

Pro tip! Because of the flexed appearance at the DIPJ, a Seymour fracture can be misinterpreted as a bony mallet injury; however, a mallet finger fracture line enters DIPJ, while the Seymour fracture line traverses physis (does not enter DIPJ).

Treatment

Non-Operative: Closed injuries are managed with closed reduction and splinting. The child may be followed up with a weekly X-ray to ensure maintenance of fracture reduction.

Operative: Substantive injuries require open reduction and nail bed repair.

Bottom Line

It is important to seek a surgical opinion regarding the management of Seymour fractures as if left untreated possible complications include osteomyelitis, malunion, and pre-closure of the physis.

Jordan’s x-ray shows an angulated Salter-Harris type II fracture to the distal phalanx, and you correctly diagnosed a Seymour fracture. You refer Jordan to the plastic surgery team, who decide to take Jordan to theatre to ensure a thorough washout and repair of the nail bed injury.

Metacarpal Fractures

Katie is a 15-year-old girl who presents to your ED with her father. He says that she had an argument with her Mum and punched a wall at home. This is not the first time an incident like this has occurred.

Katie shows you her right hand, which is grossly swollen and bruised over the dorsal surface. There are no open wounds, and she reports focal tenderness on palpation to her 5th metacarpal. There is an obvious loss of knuckle height and rotational deformity to her little finger.

During the exam, she is visibly withdrawn and quiet, and you are suspicious that there is more than a hand injury bothering Katie.  

Mechanism

Metacarpal fractures are common in adolescent athletes. The most common type of metacarpal fracture is the so-called ‘‘boxer’s fracture’’, which involves the neck of the ring or small finger metacarpal. This injury usually occurs as a result of direct bony trauma when the child/adolescent strikes a fixed object, such as a wall, with a closed fist or is struck on a fisted hand with an object, such as a bat/hurl/hockey stick for example.

Presentation

The child/adolescent will usually present with bruising, swelling and diffuse pain over the dorsum of the hand. There may be loss of knuckle prominence. Be vigilant for rotational deformity; no degree of malrotation is acceptable.

Ensure to evaluate skin integrity over the injured area, check for and document the presence of open wounds, and consider the possibility that these could be so-called ‘’fight bites’’ and will require antibiotics. Substantial injuries or infected open wounds require a surgical opinion as these may require admission for IV antibiotic cover and washout in theatre. Check integrity of flexor/extensor tendons in the presence of open wounds. Remember to check Tetanus vaccination status.

A child/adolescent who presents to the PED with a hand injury because of a fight or an injury mechanism such as punching a wall requires special attention- screening for mental health and/or social problems is paramount. Involvement of medical social worker teams or mental health teams may be necessary. The HEEADSSS screening tool may be useful to guide this line of inquiry.  

Treatment

Treatment is generally based on the level of injury (e.g. head, neck, shaft and base) and clinical findings (rotational deformities, open wounds, fracture stability).  

Un-displaced stable fractures of the neck or shaft (2nd-5th metacarpals)

Non-operative: Can be treated in rest volar splint/back -slab and followed up in clinic

Angulated neck of metacarpal fractures

Most common is a fracture of the 5th metacarpal or  a ‘‘Boxer’s fracture’’

Treatment is guided by the degree of angulation. Seek surgical opinion

Non-operative: Closed reduction in PED using nerve block +/- procedural sedation and immobilisation in cast

Operative: Surgery may be required in the presence of open wounds, suspected tendon injuries, or if the angular deformity is substantial and/ or there is a rotational deformity on clinical exam.

Displaced intra articular, unstable, comminuted or unstable fractures

Operative: These fractures all require surgical referral

Thumb metacarpal fractures

Thumb metacarpal base fractures require surgical opinion. Disruption of carpometacarpal (CMC) joint congruity can result in significant functional impairments for a child/adolescent, particularly loss or limitation of pincer or power grip.

Specific names are given to fractures of the base of the 1st metacarpal

• Bennett fracture: defined as an intra-articular 2-part fracture of the base of 1st metacarpal *(see also Reverse Bennett fracture below)
• Rolando fracture: similar to Bennett fracture, but the prognosis is worse. Defined as a comminuted intra-articular fracture of the 1st metacarpal, producing at least three parts.

X-ray demonstrates a severely angulated fracture to the neck of Katie’s 5th metacarpal bone. Taking this into consideration and the presence of rotational deformity, you refer her to the hand surgery team for management. They decide to admit her for manipulation under anaesthetic (MUA).

While awaiting admission, you get the opportunity to establish a rapport and talk to Katie about her mental health.

You use the HEEADSSS screening tool to guide your inquiry. She reveals information about difficulties at home related to her mother’s substance abuse and reports that she has been missing a lot of school due to bullying. Katie agrees that she needs help dealing with these issues, and you refer her to the inpatient mental health team with her permission. Her dad is also informed.

*Reverse Bennett fracture dislocation

An intra-articular fracture dislocation of the base of the 5th metacarpal bone is called a reverse Bennett fracture. This fracture pattern is inherently unstable and referral to hand specialist is essential.

References

Andy Neill. AFEM 033 | Hand: Lingo and soft tissues. Retrieved from https://litfl.com/bscc/clinical-anatomy/hand-anatomy/

Abzug, J. M., Dua, K., Bauer, A. S., Cornwall, R., & Wyrick, T. O. (2016). Pediatric phalanx fractures. Journal of the American Academy of Orthopaedic Surgeons, 24(11), e174-e183.

Sullivan, M. A., Cogan, C. J., & Adkinson, J. M. (2016). Pediatric hand injuries. Plastic Surgical Nursing, 36(3), 114-120.

Wahba, G., & Cheung, K. (2018). Pediatric hand injuries: Practical approach for primary care physicians. Canadian Family Physician, 64(11), 803-810.

Weber, D. M., Seiler, M., Subotic, U., Kalisch, M., & Weil, R. (2019). Buddy taping versus splint immobilization for paediatric finger fractures: a randomized controlled trial. Journal of Hand Surgery (European Volume), 44(6), 640-647.