Orthopedics

Give 'Em the Old One-Two: Boxer's Fracture

Case

A healthy 22-year-old right-handed man presents to the ED with right hand pain. He reluctantly endorses punching a concrete wall with an ungloved fist. On exam, the patient is holding his hand with fingers in partial flexion. There is mild swelling over the third through fifth MCPs with mild erythema and intact skin. Neurovascular exam is normal. Plain films were obtained.

Courtesy of Radiopedia.com

Courtesy of Radiopedia.com


What is the Diagnosis?

Fractured neck of fifth metatarsal. AKA, Boxer’s fracture

Overview

Boxer’s Fractures are a very common injury seen in the ED. Highest incidence are in men 10-19 years followed by men 20-29 years. The two most common mechanisms of injury are falls or direct blows with high axial loads (i.e. punching a fixed, inelastic object). Interestingly, despite the name, these fractures are not typically seen in experienced boxers, as boxing training aims to teach one to lead with the first and second knuckles, aligning the forces of impact into an axial load that transmits and distributes force through the larger bones and joints of the forearm and upper arm. Studies have suggested roughly 30% of hand fractures are metacarpal fractures and they account for nearly 19% of ER fracture visits. The metacarpal neck is the most commonly fractured site. The fifth metacarpal is the most commonly fractured metacarpal. Fractures to the first metacarpal are less common and are often managed operatively. First metacarpal fractures include Bennett’s fractures (fracture-dislocation of the base of the first metacarpal), and Rolandos fractures (comminuted version of Bennett’s fracture) and can also occur as a result of an axial load mechanism such as punching.

Evaluation 

Typical symptoms include tenderness or pain focally over the distal metacarpal. Physical examination should include careful inspection for possible “fight bites” given the common potential mechanism of injury. Comparing to the uninjured hand can help highlight distorted anatomy. Evaluate for possible rotational misalignment of the metacarpals by observing convergence of the finger tips with flexed MCPs and PIPs. Note that in this position, phalanxes should point to the scaphoid. Evaluate for extensor mechanism injuries. Due to the intrinsic pull of the interosseus muscles, metacarpal neck fractures typically result in dorsal angulation of the apex of the fracture, resulting in a clinical appearance of a depressed MCP joint. 

Radiology

Obtain AP, oblique, and lateral hand films

Special views: 

Brewerton View

Brewerton View

Roberts View

Roberts View

Indications for CT:

  • Inconclusive plain films with high clinical suspicion for injury

  • Complex fractures of metacarpal head

  • Multiple CMC dislocations

Associated injurieS:

Given the mechanism, skin break or lacerations over the knuckle may not only represent a potential open fracture, but should also lend themselves to a high degree of suspicion for a “fight bite,” with associated microbiological concern, and managed accordingly. Other fight-related injuries should also be considered and evaluated for as well.

Management:

Not all metacarpal fractures are managed the same. Important factors in management include degrees of shaft angulation and length of metacarpal shaft shortening, dependent on which metacarpal is injured, neurovascular status, and whether the injury is open or closed.

METACARPAL ACCEPTABLE DEGREE OF SHAFT
ANGULATION (degrees)
2nd 10
3rd 20
4th 30
5th 40

Operative indications:

  • Unacceptable degree of angulation (per table above)

  • Unacceptable shaft shortening >5 mm regardless of metacarpal

  • Rotational deformity of any digit >10 degrees

  • Multiple fractures

  • Intraarticular fracture or involvement of metacarpal head

  • Most first metacarpal fractures (Bennett’s and Rolando)

Non-Operative Treatment:

  • Analgesia

    • Consider an ulnar nerve block!

  • Reduction 

    • Using a c-arm for real-time X-ray feedback may be helpful. 

    • Jahss technique: 90 degrees flexion of MCP and the PIP (AKA 90-90 approach). Apply dorsal pressure to the proximal phalanx while stabilizing metacarpal shaft.

Jahss Technique

Jahss Technique

  • Splint 

    • Ulnar gutter for immobilization of the fourth and fifth metacarpals

    • Volar splint for immobilization of the second and third metacarpals.

  • Ice

  • Elevation

  • Tylenol/NSAIDs

  • Referral to hand surgeon for follow-up

Take home points:

  • Boxer’s Fractures are a common injury, most often seen in young men.

  • Consider wounds associated with these fractures as potential fight bites given the mechanism

  • The more radial the metacarpal involved, the less degree of angulation is acceptable without surgical intervention, while there is no degree of acceptable malrotation

Faculty Reviewer: Dr. Nicholas Asselin

References: 

  1. Nakashian et al. Incidence of metacarpal fractures in the US population. Hand. 2012. 7(4):426. 

  2. Ashkenaze and Ruby. Metacarpal fractures and dislocations. Orthopedic Clin North Am. 1992 23:19. 

  3. Haughton et al. Principles of hand fracture management. Open Orthop Journal. 2012. 6;43-55. 

Non-Accidental Trauma

Case

A hypothetical 7 month-old infant presents to the emergency department for mild respiratory distress. There is no recent illness or symptoms to explain the infant’s tachypnea and mild hypoxia. There is no visible bruising on exam. The parent states that the infant is starting to pull to stand but does not yet cruise. They have had several falls onto their tile kitchen floor. The CXR (below) is read by the radiologist left posterior rib fractures in ribs 4-8.

Case courtesy of Dr. George Harisis, Radiopaedia.org. From the case Non-Accidental Injury

Case courtesy of Dr. George Harisis, Radiopaedia.org. From the case Non-Accidental Injury

Highly Specific Fracture Patterns for Non-Accidental Trauma

A helpful adage: “Those that don’t cruise rarely bruise.” Approximately 80% of NAT occur in children less than 18 months old. A study evaluating bruising in normal infants demonstrated that only 0.01% (6 of 465) of pre-cruisers had ecchymoses. Soft tissue findings, like bruises, may tip you off to underlying or fractures either underlying or elsewhere. Pierce et al. (2010) highlighted the value of the TEN 4 FACES mnemonic to highlight concerning bruises that should prompt a workup for NAT: bruises to the Torso, Ears, and Neck in children < 4, any bruising on immobile children < 4 months, or bruising to the Frenulum, Angle of the mandible, Cheek, Eyelid, or Sclera. 

Fractures are the second most common finding in pediatric non-accidental trauma after bruising or other soft-tissue injuries. Although there are often similar fracture patterns seen in both accidental and non-accidental trauma, the fractures described below are the most highly specific for non-accidental trauma and should heighten your suspicion for intentional physical abuse:

Metaphyseal Fracture (aka “Corner” or “Bucket Handle” fractures)

A metaphyseal fracture is made up of microfractures perpendicular to the long axis of the bone, most commonly the distal ends of the tibia, femur, humerus. These microfractures are caused by the shearing forces of ligaments when a child who cannot control their limbs is shaken forcefully while held around their torso. It is highly specific fracture and is almost universally considered pathognomonic for non-accidental trauma.

Case courtesy of Dr. Basab Bhattacharya, Radiopaedia.org. From the case Non-Accidental Injuries

Case courtesy of Dr. Basab Bhattacharya, Radiopaedia.org. From the case Non-Accidental Injuries

Case courtesy of Dr. JR Dwek. From the The Radiographic Approach to Child Abuse.

Case courtesy of Dr. JR Dwek. From the The Radiographic Approach to Child Abuse.

Posterior Rib Fractures

Posterior rib fractures occur when enough anteroposterior chest compression is generated to cause movement of the posterior rib that acts as a lever over the transverse spinal process. This, like with metaphyseal fractures, can be caused by holding and shaking an infant with two hands around the ribcage. Other mechanisms include “marked forward decceleration into a solid object” in MVCs or in other non-accidental trauma. Biomechanically, the amount of force needed to cause leverage against the transverse process cannot be replicated when the patient is lying with their back against a flat surface, as is the case in CPR. A small post-mortem study of infants that had received even two-handed CPR supports this: they found anterolateral fractures but no occurrences of posterior rib fractures. In studies by Kleinman et al. (1997) and by Barsness et al. (2003) Posteromedial rib fractures have a very high positive predictive value (95%) for NAT and have the highest specificity for NAT.

Case courtesy of Dr. Paula Brill, Radiopaedia.org. From the case Non-Accidental Trauma.

Case courtesy of Dr. Paula Brill, Radiopaedia.org. From the case Non-Accidental Trauma.

The Three S’s: Spinous Process, Scapular, and Sternal Fractures

Though seen less often, spinous process, scapula, and sternum fractures round out the top most specific fractures for non-accidental trauma. Sternum and scapular fractures occur in the setting of a direct blow of unusual amounts force and are unexplained in the normal handling of most infants. As with other fractures, it is important to determine if the provided history matches the mechanism.

Other Specific Fracture Findings

  • Clavicular fractures (after the period explained by birth trauma)

  • Epiphyseal separations

  • Vertebral body fractures/separations

  • Digital fractures

  • Complex skull fractures

Next Steps

  • Mandatory reporting to Child Protective Services

  • Per the American Academy of Pediatrics, all patients undergoing workup for non-accidental trauma should be admitted to the hospital.

  • Complete a skeletal survey, which involves approximately 21 x-rays focusing on each individual limb or body part.

  • Order a CT brain to evaluate both the skull and underlying brain. Reconstructions of specific CTs may allow rotation of images and better identification of fractures.  

What Are We Missing?

In the most recent data published by the National Child Abuse and Neglect Data System, there were 1,585 fatalities due to child abuse and neglect in 2015. Approximately 44% percent of those suffered death due to physical abuse and almost 75% were children <3 years old.

A small study comparing known instances of child abuse fatalities with local medical records found that 30% of children who subsequently died from non-accidental trauma had interactions with health care for reasons other than well-child checks. Nearly 20% of those visits occurred within one month of their death. Albeit brief, emergency department visits may be the only interaction these children have with the health care system represent a critical opportunity for intervention.

 

Faculty Reviewer: Dr. Adam Aluisio

References

  1. Baldwin K, Pandya NK, Wolfgruber BA, et al. Femur Fractures in Pediatric Population: Abuse or Accidental Trauma? Clin Orthop Relat Res. 2011 Mar; 469(3):798-804.

  2. Barsness KA, Cha ES, Bensard DD, Calkins CM, Partrick DA, et al. The positive predictive value of rib fractures as an indicator of nonaccidental trauma in children. J Trauma. 2003;54:1107–1110.

  3. Bechtel K. Physical Abuse of Children: Epidemiology of Child Abuse in the United States. Emergency Medicine Reports. 2003 Mar.

  4.  Child Welfare Information Gateway. (2017). Child abuse and neglect fatalities 2015: Statistics and interventions. Washington, DC: U.S. Department of Health and Human Services, Children’s Bureau.

  5. Christian CW. Committee on Child Abuse and Neglect. The Evaluation of Suspected Child Physical Abuse. Pediatrics. 2015; 135(5):1337-1354. 

  6. Dwek JR. The Radiographic Approach to Child Abuse. Clinical Orthopaedics and Related Research. 2011;469(3):776-789.

  7. King WK, Kiesel EL, Simon HK. Child Abuse Fatalities: Are We Missing Opportunities for Intervention? Pediatric Emerg Care. 2006;22(4):211-214.

  8. Kleinman PK, Perez-Rossello JM, Newton AW, et al. Prevalence of the classic metaphyseal lesion in infants at low versus high risk for abuse. AJR Am J Roentgenol. 2011 Oct;197(4):1005-8.

  9. Kleinman PK, Schlesinger AE. Mechanical factors associated with posterior rib fractures: laboratory and case studies. Pediatr Radiol. 1997(27): 87-91.

  10.  Leaman LA, Hennrikus WL, Bresnahan JJ. Identifying non-accidental fractures in children aged <2 years . Journal of Children’s Orthopaedics. 2016;10(4):335-341.

  11. Matshes EW, Lew EO. Two-Handed Cardiopulmonary Resuscitation Can Cause Rib Fractures In Infants. Amer Journal of Forensic Med and Pathology. 2010 Dec; 31(4): 303-307.

  12. Paddock M, Sprigg A, Offiah AC. Imaging and reporting considerations for suspected physical abuse (non-accidental injury) in infants and young children. Part 1: initial considerations and appendicular skeleton. Clinical Radiology. 2017 Mar;72(3):179-188

  13. Pierce MC, Kaczor K, Aldridge S, O'Flynn J, Lorenza DJ. Bruising Characteristics Discriminating Physical Child Abuse From Accidental Trauma. Pediatrics. 2019;125(1):67-74.

  14. Sugar NF, Taylor JA, Feldman KW, and the Puget Sound Pediatric Research Network. Bruises in Infants and Toddlers Those Who Don't Cruise Rarely Bruise. Arch Pediatr Adolesc Med. 1999;153(4):399–403.

Acromioclavicular Joint Injury

Case

A 19 year-old male presents to the emergency department with a complaint of right shoulder pain. He was tackled from behind in a rugby game three days prior to presentation and has been experiencing pain over the anterior aspect of his right shoulder since that time. Physical exam is notable for tenderness over the right acromioclavicular (AC) joint and pain with both active and passive range of motion of the right shoulder. X-rays (Figure 1) show “no obvious fracture or subluxation.” However, based on your exam and clinical suspicion, closer inspection reveals abnormal alignment between the clavicle and the acromion consistent with AC joint injury.

Figure 1

Figure 1

The Acromioclavicular Joint

The acromioclavicular joint is formed by the AC ligament and the coracoclavicular (CC) ligament (Figure 2). The AC ligament provides horizontal stability to the joint while the CC ligaments provide vertical stability. (1)

In normal configuration, the inferior cortices of the clavicle and acromion are in alignment (Figure 3). Additionally, the coracoclavicular distance is normally less than 13 mm or there is a less than 5 mm difference between the left and right coracoclavicular distances. (1; 3) Figure 4 depicts normal alignment of the inferior cortices of the acromion in red and highlights the coracoclavicular distance in white.

Figure 2

Figure 2

Figure 3

Figure 3

Figure 4

Figure 4

Mechanism of Injury, Physical Examination, and Diagnosis

Acromioclavicular joint subluxation and dislocation account for approximately 10% of all traumatic shoulder injuries. (1; 3) AC joint injury results from either direct or indirect injury to the shoulder. Direct injury to the joint occurs with a direct blow to the shoulder or, more commonly, when an individual falls with their arm in an adducted position. Indirect injury to the AC joint typically occurs as a result of a fall on an outstretched hand. (1; 4) On exam, patients will have pain over the acromioclavicular joint and pain with range of motion of the shoulder. (3) Patients may hold their arm in an adducted position and there may be a visible or palpable step-off deformity over the AC joint. Additionally, the ipsilateral clavicle may appear to be high-riding or the ipsilateral shoulder may appear displaced inferiorly (Figure 5). (1; 3) In less obvious cases, provocative maneuvers (such as the cross-body adduction test and AC shear test) may be used to localize discomfort to the AC joint. (2)

If acromioclavicular joint injury is suspected, three-view radiographs of the shoulder (anteroposterior view, scapular-Y view, axillary view) and a Zanca view (a specialized anteroposterior radiograph which removes the scapula from behind the joint) allow for identification of vertical displacement of the clavicle and for anteroposterior displacement of the clavicle. (2) AP comparison views of both AC joints can also be helpful in diagnosis of AC joint injury.

Figure 5

Figure 5

Acromioclavicular Joint Injury: Rockwood Classification

Acromioclavicular joint injuries are characterized by the degree of damage to the AC ligament and the CC ligaments. (3). These injuries are further classified using the Rockwood System (Figure 6).  

Figure 6

Type I

AC Ligament Sprain
CC Ligament Intact
Joint Capsule Intact

Inferior cortices of the
clavicle and acromion
are aligned.

Type II

AC Ligament Rupture
CC Ligament Sprain
Joint Capsule Rupture

The CC distance is
increased <25%
compared to the
contralateral AC joint.

Type III

AC Ligament Rupture
CC Ligament Rupture
Joint Capsule Rupture

The CC distance is
increased 25-100%
compared to the
contralateral AC joint.

Type IV

AC Ligament Rupture
CC Ligament Rupture
Joint Capsule Rupture

The clavicle is displaced
posteriorly towards the ipsilateral
trapezius. Identify on axillary
view radiograph.

Type V

AC Ligament Rupture
CC Ligament Rupture
Joint Capsule Rupture

The CC distance is
increased >100%
compared to the
contralateral AC joint.

Type VI

AC Ligament Rupture
CC Ligament Rupture
Joint Capsule Rupture

Clavicle is displaced
inferiorly and the distal
end is located
posterior to the
coracobrachialis and
biceps tendons.

Management

Non-Operative Management

  • Type I and Type II AC joint injuries are managed non-operatively. Patients should be immobilized in a sling for 7-14 days and should then proceed with progressive range of motion exercises. Return to full activity is indicated when patients are pain-free. (1; 3)

  • Type III AC joint injuries are often managed non-operatively with immobilization in a sling and range of motion/strengthening exercises. These individuals should be referred for outpatient orthopedic follow-up. (1)

Operative Management

  • Urgent orthopedic referral is indicated in patients with neurovascular compromise, skin tenting, and significant deformity. Additionally, Type IV-VI AC injuries are typically managed surgically and, as such, require urgent orthopedic consultation.

 

Case Outcome

The patient’s radiograph and clinical exam was most consistent with a Type III acromioclavicular joint injury. He was immobilized in a sling, provided with prescriptions for ibuprofen and acetaminophen, and instructed to follow up with orthopedics for further evaluation on an outpatient basis.

Faculty Reviewer: Dr. Jeffrey Feden


References

  1. Egol, K. A., Koval, K. J., & Zuckerman, J. D. (2010). Handbook of fractures. Lippincott Williams & Wilkins.

  2. Koehler, Scott M. (2018). Acromioclavicular joint disorders. UpToDate. < https://www.uptodate.com/contents/acromioclavicular-joint-disorders?search=acromioclavicular%20joint&sectionRank=2&usage_type=default&anchor=H9685354&source=machineLearning&selectedTitle=1~35&display_rank=1#H9685354>.

  3.  Marx, J., Walls, R., & Hockberger, R. (2013). Rosen's Emergency Medicine-Concepts and Clinical Practice E-Book. Elsevier Health Sciences.

  4.  Tintinalli, J. (2015). Tintinallis emergency medicine A comprehensive study guide. McGraw-Hill Education.


Images

Figure 1: Case courtesy of Dr Henry Knipe, <a href="https://radiopaedia.org/">Radiopaedia.org</a>. From the case <a href="https://radiopaedia.org/cases/30774">rID: 30774</a>

 Figure 2: Egol, K. A., Koval, K. J., & Zuckerman, J. D. (2010). Handbook of fractures. Lippincott Williams & Wilkins.

Figure 3: Richardson, Michael L. (1998). Radiographic anatomy of the skeleton: Shoulder—Internal rotation view. Obtained from <http://uwmsk.org/RadAnat/IntRotLabelled.html>.

Figure 4: Kang, K. S., Lee, H. J., Lee, J. S., Kim, J. Y., & Park, Y. B. (2009). Long term follow up results of the operative treatment of the acromioclavicular joint dislocation with a Wolter plate. Journal of the Korean Fracture Society, 22(4), 259-263.

Figure 5: Greene, Tim (ND). CoreEM: Acromioclavicular joint injury. Obtained from <https://coreem.net/core/ac-joint-injuries/>.

Figure 6:

Type I: Case courtesy of Dr Henry Knipe, <a href="https://radiopaedia.org/">Radiopaedia.org</a>. From the case <a href="https://radiopaedia.org/cases/28623">rID: 28623</a>

Type II: Case courtesy of Dr Henry Knipe, <a href="https://radiopaedia.org/">Radiopaedia.org</a>. From the case <a href="https://radiopaedia.org/cases/60140">rID: 60140</a>

Type III: Case courtesy of Dr Henry Knipe, <a href="https://radiopaedia.org/">Radiopaedia.org</a>. From the case <a href="https://radiopaedia.org/cases/30949">rID: 30949</a>

Type IV: Case courtesy of Dr Craig Hacking, <a href="https://radiopaedia.org/">Radiopaedia.org</a>. From the case <a href="https://radiopaedia.org/cases/64411">rID: 64411</a>

Type V: Case courtesy of Dr Bruno Di Muzio, <a href="https://radiopaedia.org/">Radiopaedia.org</a>. From the case <a href="https://radiopaedia.org/cases/44768">rID: 44768</a>

 Type VI: Case courtesy of Dr Jeffrey Hocking, <a href="https://radiopaedia.org/">Radiopaedia.org</a>. From the case <a href="https://radiopaedia.org/cases/48600">rID: 48600</a>