Spontaneous resolution of a ‘ping-pong’ fracture at birth

Abstract

‘Ping-pong’ fractures are depressed skull fractures in newborn infants that occur as inward buckling of the calvarial bones, forming a cup shape. These fractures are often associated with maintenance of bone continuity. These fractures may occur spontaneously during the intrauterine period or secondary to birth trauma. Currently, there is no standard protocol for the management of depressed skull fractures. Neurosurgical or non-surgical approaches may be administered depends on the severity of the fracture. Most untreated ping-pong fractures resolve spontaneously within 6 months. Therefore, it is recommended to reserve surgical elevation or non-surgical techniques for infants not demonstrating spontaneous resolution during this period. In addition, neurosurgical interventions are usually considered for cases with intracranial pathology or neurological deficits or for infants who do not respond to conservative treatment. Herein, we report a case of a newborn infant with a spontaneous intrauterine ping-pong fracture, which spontaneously resolved, without surgical or non-surgical intervention.

Background

‘Ping-pong’ fractures are depressed skull fractures (DSFs) in newborn infants that occur as inward buckling of the calvarial bones forming a cup shape. These fractures are often associated with maintenance of bone continuity.¹ Ping-pong fractures in newborns are rare, with an estimated occurrence of 1–2.5 cases per 10 000 live births. They develop in two distinct forms: iatrogenic or spontaneous.² Treatment options are controversial and include either non-surgical elevation or direct operative techniques, or spontaneous elevation over time.¹ Herein, we report a case of a newborn infant with a spontaneous intrauterine ping-pong fracture, which spontaneously resolved, without surgical or non-surgical intervention. This case is clinically interesting due to the rarity of this condition and the spontaneous resolution of the fracture.

Case presentation

A 3250 g singleton, male infant was delivered by a 32-year-old woman, through planned, repeat caesarean section at 39 weeks of gestation. There were no complications or trauma history reported during pregnancy. Postbirth examination revealed a depression in the right parietal skull, measuring approximately 3×3 cm with 4 mm depth (figure 1). Apgar scores at 1 and 5 min were 8 and 9, respectively. The head circumference was 35 cm (50th–75th percentile for age) and there was no evidence of neurological or physical abnormalities. Cranial CT revealed a ping-pong fracture of the right parietal skull without oedema or haemorrhage in the brain (figure 2). Three-dimensional reconstruction imaging revealed a 3×3 cm depression on the parietal area (figure 3).

Figure 1.

Photography of the newborn after birth showed the right parietal depression of the skull (arrow).

Figure 2.

Axial CT scan showed depression of the right parietal area of the skull (arrow) without intraparenchymal injury.

Figure 3.

Three-dimensional CT reconstruction revealed the invagination of the parietal bone with no evidence of break line (arrow).

Outcome and follow-up

Considering the absence of intracranial involvement and because the depth of the fracture was not posing serious complications, we decided to allow the fracture to improve spontaneously and follow the patient non-operatively. The infant was observed for 10 days, discharged and followed up for neurological and neonatal outcomes. By 6 months of age, the depression had completely resolved. The infant exhibited neurological normalcy, meeting all developmental milestones.

Discussion

Congenital DSF may occur spontaneously or secondary to birth trauma. Although rare, they are occasionally observed in newborns following an uneventful pregnancy and non-traumatic delivery and are therefore described as ‘spontaneous’. The main causes of DSF following non-traumatic labour may be compression of the skull against the maternal ischial bone, sacral promontory, symphysis pubis, uterine fibroid, the fifth lumbar vertebrae and fetal hands or part of a twin or asymmetrical pelvis. Such fractures are commonly defined as spontaneous intrauterine fractures. Ping-pong fractures most commonly involve the frontal, parietal and occipital bones. Due to immature ossification, prolonged focal pressure on a neonatal skull may lead to ping-pong fractures, with indentation of the bone surface and undisrupted bone continuity.³ Trauma-related ping-pong fractures are often the result of instrument-assisted deliveries, involving the use of forceps, exposure of the head to pressure from the pelvis during delivery or exposure to extensive pressure while pushing up the head during caesarean section.⁴ Severe clinical complications, including epidural or subdural haematoma, cerebral contusions, parenchymal lesions, immediate neurological consequences and long-term deficits (epilepsy or brain tumours), may be observed in these patients, especially in compound DSF.^{1 5–7} In the present case, the parietal area was involved without any intracranial pathology or neurological deficits, and there was no history of trauma or instrument-assisted delivery.

Currently, there is no standard protocol for the management of DSF. Neurosurgical or non-surgical interventions or waiting for spontaneous resolution of the fracture are the clinical approaches in the treatment of these fractures.^1–5 Several non-surgical interventions may be used to elevate the depression, such as application of digital pressure on the edges of the depressed area and vacuum techniques involving a breast pump and vacuum extractor. Raynor and Parsa⁸ reported a new method for the treatment of DSF in a 9-month-old infant. The fracture was improved through the application of thumb pressure to the margins of the depression. Schrager⁹ first described the application of negative pressure by a breast pump for the reduction of depressed fractures. Tan and Van Enk^{10 11} were the first to successfully use the vacuum extractor for the reduction of a depressed fracture. Hung et al¹² previously used obstetrical vacuum extractors for the treatment of 14 patients with simple DSF deeper than 5 mm and longer than 2 cm. The reported success rate in this study was 92.9% (13 of 14 patients). However, vacuum devices are characterised by limitations, including patient discomfort, incomplete correction of the depression, local oedema or redness. In addition, the use of vacuum extraction is limited to patients not exceeding the age of 2 years.¹² Zalatimo et al¹ successfully used a novel method of percutaneous screw elevation with self-tapping microscrews (4 or 5 mm) for the treatment of four patients with ping-pong fractures deeper than 2 cm without intracranial pathology. López-Elizalde et al¹³ used a new medical device comprising two elements (a paediatric cardiopulmonary resuscitation mask connected to a 50 mL syringe) for the elevation of DSF without underlying brain damage in nine patients. They concluded that this new device was a safe and effective option for the treatment of simple DSF in newborns and infants, if it is applied within 3 days after the fracture.

Dupuis et al⁵ compared 68 cases of spontaneous and instrumental obstetric DSF. They demonstrated that spontaneous fractures are invariably associated with a good prognosis. They also showed that instrumental-associated injuries were linked to the development of intracranial lesions, rarely resulting in severe long-term neurological disabilities (4%). Thus, they recommended performing CT for depressed fractures resulting from instrumental-associated injuries. Steinbok et al¹⁴ reported no difference in outcome between surgically treated and non-surgically treated children with simple DSF in terms of seizures, neurological dysfunction or cosmetic appearance. Therefore, they suggested that surgical intervention should not be performed for infants with simple DSF.

According to the literature, the use of surgery for the treatment of patients with DSF is recommended for those who have fragments in the brain parenchyma, epicerebral, subcerebral or intracerebral haematoma, neurological deficits, signs of increased intracranial pressure, leakage of the cerebrospinal fluid and definitive evidence of dural penetration and for those who do not respond to conservative treatment. For cases with simple DSF deeper than 5 mm and longer than 2 cm without intracranial pathology, the application of vacuum extraction may be considered instead of surgery.^{5 14–16}

Most untreated ping-pong fractures resolve spontaneously within 6 months.^{2 16} Basaldella et al² reported two cases of spontaneous intrauterine ping-pong fractures following caesarean section that resolved spontaneous within 8 months. Hanlon et al¹⁶ presented a neonatal case with right parietal skull depression due to vacuum extraction during labour that improved spontaneously within 4 months. In the present patient, the ping-pong fracture was <5 mm in depth, the intracranial area was not affected and the neonate had no neurological symptoms, such as seizures. Therefore, interventions were not considered, and spontaneous resolution of the fracture was allowed. Consistent with previous reports, the condition of the present infant improved spontaneously within a few months without neurological sequelae.^{2 16}

In conclusion, although the management of spontaneous neonatal skull depression remains controversial, spontaneous resolution without surgical or non-surgical interventions is recommended in the absence of intracranial involvement or neurological symptoms.

Learning points.

• Congenital depressed skull fractures can occur spontaneously during intrauterine period or secondary to birth trauma.

• There is no standard protocol for the management of depressed skull fractures and may involve either neurosurgical or non-surgical approaches or spontaneous fracture resolution.

• Spontaneous resolution without surgical or non-surgical interventions can be recommended in the absence of intracranial involvement or neurological symptoms.

• Spontaneously depressed skull fractures in newborns have good prognosis.