Overview
A biparietal bone fracture is a break that involves both parietal bones of the skull – the large, roughly triangular bones that form the majority of the cranial vault on the top and sides of the head. The term “biparietal” indicates that the injury spans across the mid‑line, often affecting the sagittal suture where the two parietal bones meet. Although fractures of the parietal bone are less common than those of the temporal or frontal bones, they can occur in high‑impact trauma such as motor‑vehicle collisions, falls from height, or assault.
Who it affects: The condition is most frequently seen in males (approximately 70 % of cases) and in individuals aged 15‑45 years, reflecting the age groups most likely to experience severe head trauma. However, older adults with osteoporosis or children with undeveloped cranial bones can also sustain biparietal fractures.
Prevalence: According to the National Center for Injury Prevention and Control, skull fractures account for about 5–10 % of all traumatic brain injuries (TBI) in the United States. Of these, biparietal fractures represent roughly 2–4 % of skull fractures, translating to an estimated 8,000–12,000 cases per year in the U.S. alone.1,2
Symptoms
Symptoms can range from subtle to life‑threatening, depending on the fracture’s size, displacement, and whether underlying brain tissue is injured.
- Localized pain – tenderness over the top of the head, especially at the midline.
- Visible deformity – a palpable ridge, step-off, or depression along the skull.
- Swelling or bruising – known as “racoon eyes” (periorbital ecchymosis) if the fracture extends to adjacent bones.
- Scalp lacerations – cuts that may accompany the fracture.
- Neurological signs – headache, dizziness, nausea, vomiting, confusion, loss of consciousness, or amnesia.
- Seizures – can occur immediately after injury or develop later.
- Visual disturbances – double vision or blurred vision if the fracture impacts the optic pathways.
- Hearing changes – tinnitus or hearing loss if the fracture extends toward the temporal region.
- CSF leak – clear fluid dripping from the ears or nose, indicating a dural tear.
- Motor deficits – weakness or numbness in the limbs if there is associated brain injury.
Causes and Risk Factors
Direct Causes
- Motor‑vehicle collisions – rapid deceleration forces can crush the skull against the headrest or windshield.
- Falls – especially from heights greater than 6 ft (1.8 m) or falls onto a hard surface.
- Assault or violent altercations – blunt objects or punches delivering concentrated force.
- Sports injuries – high‑impact contact sports (football, rugby, boxing) where helmets are not used or are compromised.
- Explosive blasts – military personnel exposed to blast over‑pressure.
Risk Factors
- Male gender (higher exposure to high‑risk activities).
- Age 15‑45 years (peak years for trauma).
- Alcohol or substance use – impairs judgment and balance.
- Occupations with high fall risk (construction, roofing).
- Pre‑existing skull abnormalities (e.g., craniosynostosis) or osteoporosis.
- Non‑use of protective headgear in sports or occupational settings.
Diagnosis
Accurate diagnosis requires a combination of clinical evaluation and imaging.
Initial Assessment
- Primary survey (ABCs – airway, breathing, circulation).
- Neurological examination using the Glasgow Coma Scale (GCS).
- Inspection for scalp lacerations, bruising, and palpable step‑offs.
Imaging Studies
- CT scan (non‑contrast head CT) – the gold standard; quickly detects bony displacement, comminution, and associated intracranial hemorrhage.
- 3‑D reconstruction CT – useful for surgical planning.
- Plain X‑ray – rarely sufficient alone; may miss subtle fractures.
- MRI – not for bony details but valuable for assessing brain contusion, edema, or diffuse axonal injury when CT is equivocal.
According to the American College of Radiology, a head CT should be performed in any patient with a GCS ≤ 14, signs of skull fracture, persistent vomiting, or focal neurological deficits.3
Treatment Options
Management depends on fracture severity, displacement, and presence of associated brain injury.
Conservative (Non‑Surgical) Care
- Observation – most nondisplaced biparietal fractures are managed with close neurological monitoring for 24‑48 hours.
- Pain control – acetaminophen or short‑course NSAIDs; avoid high‑dose aspirin if intracranial bleeding is a concern.
- Anticonvulsants – prophylactic levetiracetam may be given for 7 days in patients with a high seizure risk.
- Activity restriction – avoid contact sports, heavy lifting, or activities that raise intracranial pressure for 4‑6 weeks.
Surgical Intervention
Surgery is indicated for displaced fractures, depressed bone fragments, or when the fracture compromises the dura or causes a growing skull fracture in children.
- Craniotomy – elevation of depressed fragments, debridement of bone fragments, and repair of dural tears.
- Internal fixation – titanium plates or screws may be used to stabilize the parietal bones.
- Decompressive craniectomy – rare, performed if there is severe brain swelling.
Adjunctive Treatments
- Antibiotics – indicated if there is an open fracture or dural breach to prevent meningitis.
- Vaccinations – tetanus booster if the wound is contaminated.
- Rehabilitation – physical, occupational, or speech therapy for neurological deficits.
Living with a Biparietal Bone Fracture
Even after the fracture heals, patients often need to adapt daily activities to protect the healing skull.
- Head protection – wear a well‑fitted protective helmet when engaging in any activity with a risk of head impact.
- Pain management – continue acetaminophen as needed; avoid chronic NSAID use unless directed by a physician.
- Sleep hygiene – use a soft pillow; avoid sleeping on the injured side for the first few weeks.
- Gradual return to activity – follow a stepwise plan (light aerobic activity → moderate → full sports) after clearance from a physician.
- Monitor for late symptoms – new headaches, visual changes, or seizures weeks to months after injury warrant re‑evaluation.
- Psychological support – head trauma can cause anxiety or post‑traumatic stress; counseling may be beneficial.
Prevention
- Always wear a properly fitted helmet when bicycling, skateboarding, skiing, or participating in contact sports.
- Use safety restraints (seat belts, airbags) in vehicles; ensure child safety seats are correctly installed.
- Maintain a safe environment at home and work – install handrails, non‑slip flooring, and adequate lighting to prevent falls.
- Limit alcohol consumption, especially when driving or engaging in high‑risk activities.
- Engage in regular bone‑health activities (weight‑bearing exercise, adequate calcium and vitamin D intake) to reduce fracture risk in older adults.
Complications
If a biparietal fracture is left untreated or inadequately managed, several serious complications can arise:
- Intracranial hemorrhage – epidural, subdural, or intracerebral bleeding leading to increased intracranial pressure.
- Brain contusion or laceration – bruising or tearing of brain tissue underlying the fracture.
- Seizures – both early (within 24 hours) and late‑onset seizures.
- Infection – meningitis or osteomyelitis if the dura is breached or the fracture is open.
- Growing skull fracture – rare in children; the fracture enlarges over time due to CSF pulsation.
- Cosmetic deformity – palpable ridge or depression may be aesthetically concerning.
- Neurocognitive deficits – memory, attention, or executive function problems if the underlying brain is injured.
When to Seek Emergency Care
- Loss of consciousness lasting longer than a few seconds.
- Severe or worsening headache that does not improve with over‑the‑counter medication.
- Repeated vomiting or nausea.
- Clear fluid (cerebrospinal fluid) leaking from the nose or ears.
- Visible skull deformation, large swelling, or a deep scalp wound.
- Confusion, disorientation, slurred speech, or inability to recognize people.
- Weakness, numbness, or loss of movement in any part of the body.
- Seizures (any type) or a sudden change in behavior.
- Unequal pupil size or eyes that do not respond to light.
- Bleeding that does not stop after applying pressure for 10 minutes.
References:
- Mayo Clinic. “Skull Fractures.” Accessed March 2024. https://www.mayoclinic.org
- Centers for Disease Control and Prevention. “Traumatic Brain Injury in the United States: Fact Sheet.” 2023. https://www.cdc.gov/traumaticbraininjury
- American College of Radiology. “ACR Appropriateness Criteria® Head Trauma.” 2022. https://www.acr.org
- Cleveland Clinic. “Skull Fracture.” Updated 2023. https://my.clevelandclinic.org
- World Health Organization. “Road traffic injuries.” 2022. https://www.who.int