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Neonatal distal femoral physeal injury secondary to mechanical trauma of birth: A case report
Clinical Imaging 51 (2018) 65–67
Contents lists available at ScienceDirect
Clinical Imaging journal homepage: www.elsevier.com/locate/clinimag
Case Report
Neonatal distal femoral physeal injury secondary to mechanical trauma of birth: A case report
T
⁎
Arie Franco , Apeksha Chaturvedi Department of Medical Imaging, University of Rochester, 601 Elmwood Avenue, P.O. Box 648, Rochester, NY 14642, United States
A R T I C L E I N F O
A B S T R A C T
Keywords: Neonate Physis Femur Injury
Physeal injuries occurring secondary to neonatal birth-related trauma are rare entities. Most reported cases of physeal injury involve the distal humerus with only a few published case reports of proximal femoral involvement. So far, we have found only one reported case of neonatal distal femoral epiphysiolysis following Caesarean section. We hereby report a unique case of distal femoral physeal injury with at least partial epiphyseal separation following an uneventful, spontaneous vaginal delivery. Given the uneventful delivery and no known prenatal risk factors, the imaging findings were initially not recognized as being secondary to birth-related injury. Nonaccidental trauma and infection were considered among the possible etiologies for the clinical and imaging findings and a detailed workup for both these entities was performed. Distal femoral physeal injury was considered as a diagnosis of exclusion only after both initial differential considerations were excluded. The authors hope that a knowledge of this entity will facilitate a more accurate differential in cases of thigh swelling and hypomobility in the newborn.
1. Introduction Traumatic neonatal physeal fracture with epiphyseal separation is a rare entity which has most often been described at the distal humerus. Fewer cases of proximal femoral involvement have also been described. So far, we have found only one report of distal femoral epiphysiolysis following a Caesarean section, reported by Tier in 1992 [1]. Most reported cases of physeal injury occurred following traumatic vaginal or Caesarean birth. We present a unique case of distal femoral physeal injury with at least partial epiphyseal separation following an uneventful vaginal delivery. Although the etiology of this entity in our case is uncertain, we hypothesize that it was likely secondary to occult trauma sustained during delivery. 2. Case report A female, 35 weeks gestational age, weight of 2665 g, appropriate for gestational age, was born via an uneventful spontaneous vaginal delivery, vertex presentation. The pregnancy was complicated by chronic hypertension, pre-eclampsia and an elevated glucose tolerance test that normalized at 3 h. Upon delivery, the newborn appeared alert, active, and was appropriately responsive; overall an unremarkable examination. Over the first few hours of life, however, the neonate became
⁎
increasingly fussy. Upon physical examination, significant swelling and induration of the left thigh was observed. Subsequently, left femoral radiographs were performed which revealed metaphyseal irregularity within the anteromedial distal left femoral metaphysis (Fig. 1). The radiologist interpreted these findings as “metaphyseal corner fracture”, which raised suspicion for nonaccidental trauma and led to a complete skeletal survey. The skeletal survey was negative with the exception of the known abnormality within the distal left femur. After an extensive workup, non-accidental trauma was excluded. The neonate was then admitted to the neonatal intensive care unit for sepsis work-up and treatment. As part of this workup, a contrast MR of the left thigh was obtained, which was remarkable for stripping of the periosteum surrounding the distal femoral metaphysis. There was slight offset of the distal femoral epiphysis with respect to its adjacent metaphysis, suggesting at least partial distal femoral epiphyseal separation secondary to physeal injury (Figs. 2, 3). There was no evidence for osteomyelitis on either imaging or lab work. Upon exclusion of the initially considered differentials, occult birthrelated trauma leading to physeal injury was believed to represent the underlying etiology for the clinical and radiologic findings. Follow-up radiographs revealed expected interval healing of this physeal injury (Fig. 4). The child, now nearly 2, has since been thriving and regularly attends well-child visits at her pediatrician's office.
Corresponding author. E-mail addresses: [email protected] (A. Franco), [email protected] (A. Chaturvedi).
https://doi.org/10.1016/j.clinimag.2018.02.006 Received 5 November 2017; Received in revised form 19 January 2018; Accepted 6 February 2018 0899-7071/ © 2018 Elsevier Inc. All rights reserved.
Clinical Imaging 51 (2018) 65–67
A. Franco, A. Chaturvedi
Fig. 3. Sagittal contrast-enhanced, fat-suppressed T1-weighted magnetic resonance image of the left thigh demonstrates slight offset of the epiphysis of the distal femur with respect to its corresponding metaphysis (arrows placed at the junction of the epiphysis with the metaphysis). This suggests at least partial epiphyseal separation. There was no abnormal marrow enhancement to indicate osteomyelitis. Patchy enhancement of the epiphysis is in keeping with age-appropriate appearances of the highly vascularized epiphyseal cartilage and does not indicate pathology.
Fig. 1. Lateral radiograph of the left femur obtained on day 1 of life demonstrates metaphyseal irregularity simulating “corner fracture” involving the distal femur (arrow). The distal femoral epiphysis is largely unossified, with only a small ossified focus, making it difficult to infer the position of the epiphysis with respect to the metaphysis. There is soft tissue swelling involving the thigh (star). The bone density is normal.
Fig. 2. Coronal fluid-sensitive, fat suppressed magnetic resonance image of the distal left femur obtained at day 4 of life demonstrates periosteal stripping at the distal femoral metaphysis (thin arrows). The cartilaginous epiphysis has been highlighted with thick block arrows.
Fig. 4. Follow-up plain radiograph of the distal left femur obtained at seven days of life documents early healing response at the distal femur (arrows).
3. Discussion case is unknown. Our patient had an uneventful vaginal delivery, vertex presentation, factors that cannot entertain the mechanism of our patient injury as a difficult delivery. The initial radiological presentation of this case was distal femoral metaphyseal irregularity simulating corner fracture, which led to the hypothesis of a non-accidental trauma. This was however rapidly eliminated by social investigation and by fully cooperative parents. Infection was considered as an alternative etiology for these findings, but the subsequent lab and imaging work-up was negative. Contrastenhanced MRI performed as part of the sepsis work-up revealed a distal femoral physeal injury with at least partial epiphyseal separation and the neonate was referred for orthopedic management. During pregnancy, the growth plate evolves from a highly cellular structure with relatively poor columnar organization and matrix development to the well-known structure seen later in postnatal life. The
Neonatal epiphyseal separation secondary to birth-related trauma is a rare event. The first such reported case involved separation of the distal epiphysis of the humerus, described by Camera in 1926 [2]. Since then, there have been additional occasional reports of this rare injury [3–5]. Separation of the distal humeral epiphysis reportedly accounts for only 0.7% of pediatric cases of growth plate injury. Such injuries usually occur secondary to rotatory or shear force associated with birth trauma or child abuse [5]. So far, we have found only one report of physeal fracture with distal femoral epiphysiolysis following birth [1], although there are few reports of neonatal proximal femoral epiphysiolysis. Rotatory or shear forces on the knee, which can be caused by birth-related or inflicted trauma in neonates are probably responsible for such an injury. A hyperextension force on an outstretched thigh may cause this injury in children [2]. The exact mechanism of injury of the distal femur in our 66
Clinical Imaging 51 (2018) 65–67
A. Franco, A. Chaturvedi
incompletely ossified epiphysis at birth. MR provides detailed multiplanar visualization of the cartilage, bone and soft tissues, facilitating accurate diagnosis. We present a very rare case of a neonatal distal femoral physeal injury from occult, likely birth-related trauma. Previous reports have described this entity at the distal humerus [5] and within the proximal femur [1]. To the best of our knowledge, this is the first report of a neonatal distal femoral physeal injury following an uneventful vaginal birth. This article does not contain any studies with human participants or animals performed by any of the authors. For this type of study formal consent is not required.
thickness of the growth plate decreases in prenatal life. This decrease results from losses of both matrix and cellular components, mostly of the latter. However, the relative fraction of area occupied by the matrix significantly increases, indicating a maturation process of the plate towards a more matrix-oriented structure with age. Plate thickness does not decrease further in the final 3 weeks of pregnancy and increases in early neonatal life [6]. The growth plate is at its thinnest at 35 weeks of pregnancy, time that our patient was born. This may have been a contributing factor to our patient's injury. The perichondrium surrounds the periphery of the growth plate and contains the ossification groove of Ranvier and the ring of LaCroix. The groove of Ranvier is wedge-shaped, surrounds the periphery of the growth plate, and is responsible for transverse growth of the growth plate. The ring of LaCroix is a dense fibrous band that provides mechanical support to the chondro-osseous junction and is continuous with the periosteum. The perichondral vessels supply the perichondrium and most peripheral aspects of the growth plate, making the central growth plate relatively vulnerable to insult [7]. Both direct and indirect injuries to the growth plate can occur; this is an example of a direct injury [8]. As the delivery of our patient was uneventful and there were no findings to support a postnatal non-accidental trauma or infection, we hypothesize that our patient underwent an occult trauma at the growth plate of the distal femur, possibly related to the process of birth. We emphasize that physeal separation with epiphyseal separation of the distal femur constitutes a rare and possibly under recognized manifestation of birth-related trauma. A lack of familiarity with this entity can engender unnecessary anxiety and lead to inefficient utilization of imaging. The entity presents a diagnostic challenge; radiographic findings can be difficult to interpret in the setting of an
References [1] Trier H. Epiphysiolysis in the distal femur as a birth injury in cesarean section. Ugeskr. Laeger 1992 May 25;154(22):1574–5. [2] Lin Rui-Lan, Liu Zhen-Jiang, Zhang Li-Jun. Neonatal distal humeral physeal separation during caesarean section: a case report and review of a literature. Int. J. Clin. Exp. Med. 2016;9(3):6882–9. [3] Raupp P, Haas D, Lovasz G. Epiphyseal separation of the distal humerus. J. Perinat. Med. 2002;30:528–30. [4] Downs DM, Wirth CR. Fracture of the distal humeral chondroepiphysis in the neonate. A case report. Clin. Orthop. Relat. Res. 1982:155–8. [5] Gigante C, Kini SG, Origo C, Volpin A. Transphyseal separation of the distal humerus in newborns. Chin. J. Traumatol. 2017;20(3):183–6. [6] Navallas M, Díaz-Ledo F, Ares J, SánchezBuenavida A, López-Vilchez MA, Solano A, et al. Distal humeral epiphysiolysis in the newborn: utility of sonography and differential diagnosis. Clin. Imaging 2013;37:180–4. [7] Rodriguez JI, Razquin S, Palacios J, Rubio V. Human growth plate development in the fetal and neonatal period. J. Orthop. Res. 1992 Jan;10(1):62–71. [8] Nguyen JC, Keegan Markhardt B, Merrow AC, Dwek JR. Imaging of pediatric growth plate disturbances. RadioGraphics 2017;37:1791–812.
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Contents lists available at ScienceDirect
Clinical Imaging journal homepage: www.elsevier.com/locate/clinimag
Case Report
Neonatal distal femoral physeal injury secondary to mechanical trauma of birth: A case report
T
⁎
Arie Franco , Apeksha Chaturvedi Department of Medical Imaging, University of Rochester, 601 Elmwood Avenue, P.O. Box 648, Rochester, NY 14642, United States
A R T I C L E I N F O
A B S T R A C T
Keywords: Neonate Physis Femur Injury
Physeal injuries occurring secondary to neonatal birth-related trauma are rare entities. Most reported cases of physeal injury involve the distal humerus with only a few published case reports of proximal femoral involvement. So far, we have found only one reported case of neonatal distal femoral epiphysiolysis following Caesarean section. We hereby report a unique case of distal femoral physeal injury with at least partial epiphyseal separation following an uneventful, spontaneous vaginal delivery. Given the uneventful delivery and no known prenatal risk factors, the imaging findings were initially not recognized as being secondary to birth-related injury. Nonaccidental trauma and infection were considered among the possible etiologies for the clinical and imaging findings and a detailed workup for both these entities was performed. Distal femoral physeal injury was considered as a diagnosis of exclusion only after both initial differential considerations were excluded. The authors hope that a knowledge of this entity will facilitate a more accurate differential in cases of thigh swelling and hypomobility in the newborn.
1. Introduction Traumatic neonatal physeal fracture with epiphyseal separation is a rare entity which has most often been described at the distal humerus. Fewer cases of proximal femoral involvement have also been described. So far, we have found only one report of distal femoral epiphysiolysis following a Caesarean section, reported by Tier in 1992 [1]. Most reported cases of physeal injury occurred following traumatic vaginal or Caesarean birth. We present a unique case of distal femoral physeal injury with at least partial epiphyseal separation following an uneventful vaginal delivery. Although the etiology of this entity in our case is uncertain, we hypothesize that it was likely secondary to occult trauma sustained during delivery. 2. Case report A female, 35 weeks gestational age, weight of 2665 g, appropriate for gestational age, was born via an uneventful spontaneous vaginal delivery, vertex presentation. The pregnancy was complicated by chronic hypertension, pre-eclampsia and an elevated glucose tolerance test that normalized at 3 h. Upon delivery, the newborn appeared alert, active, and was appropriately responsive; overall an unremarkable examination. Over the first few hours of life, however, the neonate became
⁎
increasingly fussy. Upon physical examination, significant swelling and induration of the left thigh was observed. Subsequently, left femoral radiographs were performed which revealed metaphyseal irregularity within the anteromedial distal left femoral metaphysis (Fig. 1). The radiologist interpreted these findings as “metaphyseal corner fracture”, which raised suspicion for nonaccidental trauma and led to a complete skeletal survey. The skeletal survey was negative with the exception of the known abnormality within the distal left femur. After an extensive workup, non-accidental trauma was excluded. The neonate was then admitted to the neonatal intensive care unit for sepsis work-up and treatment. As part of this workup, a contrast MR of the left thigh was obtained, which was remarkable for stripping of the periosteum surrounding the distal femoral metaphysis. There was slight offset of the distal femoral epiphysis with respect to its adjacent metaphysis, suggesting at least partial distal femoral epiphyseal separation secondary to physeal injury (Figs. 2, 3). There was no evidence for osteomyelitis on either imaging or lab work. Upon exclusion of the initially considered differentials, occult birthrelated trauma leading to physeal injury was believed to represent the underlying etiology for the clinical and radiologic findings. Follow-up radiographs revealed expected interval healing of this physeal injury (Fig. 4). The child, now nearly 2, has since been thriving and regularly attends well-child visits at her pediatrician's office.
Corresponding author. E-mail addresses: [email protected] (A. Franco), [email protected] (A. Chaturvedi).
https://doi.org/10.1016/j.clinimag.2018.02.006 Received 5 November 2017; Received in revised form 19 January 2018; Accepted 6 February 2018 0899-7071/ © 2018 Elsevier Inc. All rights reserved.
Clinical Imaging 51 (2018) 65–67
A. Franco, A. Chaturvedi
Fig. 3. Sagittal contrast-enhanced, fat-suppressed T1-weighted magnetic resonance image of the left thigh demonstrates slight offset of the epiphysis of the distal femur with respect to its corresponding metaphysis (arrows placed at the junction of the epiphysis with the metaphysis). This suggests at least partial epiphyseal separation. There was no abnormal marrow enhancement to indicate osteomyelitis. Patchy enhancement of the epiphysis is in keeping with age-appropriate appearances of the highly vascularized epiphyseal cartilage and does not indicate pathology.
Fig. 1. Lateral radiograph of the left femur obtained on day 1 of life demonstrates metaphyseal irregularity simulating “corner fracture” involving the distal femur (arrow). The distal femoral epiphysis is largely unossified, with only a small ossified focus, making it difficult to infer the position of the epiphysis with respect to the metaphysis. There is soft tissue swelling involving the thigh (star). The bone density is normal.
Fig. 2. Coronal fluid-sensitive, fat suppressed magnetic resonance image of the distal left femur obtained at day 4 of life demonstrates periosteal stripping at the distal femoral metaphysis (thin arrows). The cartilaginous epiphysis has been highlighted with thick block arrows.
Fig. 4. Follow-up plain radiograph of the distal left femur obtained at seven days of life documents early healing response at the distal femur (arrows).
3. Discussion case is unknown. Our patient had an uneventful vaginal delivery, vertex presentation, factors that cannot entertain the mechanism of our patient injury as a difficult delivery. The initial radiological presentation of this case was distal femoral metaphyseal irregularity simulating corner fracture, which led to the hypothesis of a non-accidental trauma. This was however rapidly eliminated by social investigation and by fully cooperative parents. Infection was considered as an alternative etiology for these findings, but the subsequent lab and imaging work-up was negative. Contrastenhanced MRI performed as part of the sepsis work-up revealed a distal femoral physeal injury with at least partial epiphyseal separation and the neonate was referred for orthopedic management. During pregnancy, the growth plate evolves from a highly cellular structure with relatively poor columnar organization and matrix development to the well-known structure seen later in postnatal life. The
Neonatal epiphyseal separation secondary to birth-related trauma is a rare event. The first such reported case involved separation of the distal epiphysis of the humerus, described by Camera in 1926 [2]. Since then, there have been additional occasional reports of this rare injury [3–5]. Separation of the distal humeral epiphysis reportedly accounts for only 0.7% of pediatric cases of growth plate injury. Such injuries usually occur secondary to rotatory or shear force associated with birth trauma or child abuse [5]. So far, we have found only one report of physeal fracture with distal femoral epiphysiolysis following birth [1], although there are few reports of neonatal proximal femoral epiphysiolysis. Rotatory or shear forces on the knee, which can be caused by birth-related or inflicted trauma in neonates are probably responsible for such an injury. A hyperextension force on an outstretched thigh may cause this injury in children [2]. The exact mechanism of injury of the distal femur in our 66
Clinical Imaging 51 (2018) 65–67
A. Franco, A. Chaturvedi
incompletely ossified epiphysis at birth. MR provides detailed multiplanar visualization of the cartilage, bone and soft tissues, facilitating accurate diagnosis. We present a very rare case of a neonatal distal femoral physeal injury from occult, likely birth-related trauma. Previous reports have described this entity at the distal humerus [5] and within the proximal femur [1]. To the best of our knowledge, this is the first report of a neonatal distal femoral physeal injury following an uneventful vaginal birth. This article does not contain any studies with human participants or animals performed by any of the authors. For this type of study formal consent is not required.
thickness of the growth plate decreases in prenatal life. This decrease results from losses of both matrix and cellular components, mostly of the latter. However, the relative fraction of area occupied by the matrix significantly increases, indicating a maturation process of the plate towards a more matrix-oriented structure with age. Plate thickness does not decrease further in the final 3 weeks of pregnancy and increases in early neonatal life [6]. The growth plate is at its thinnest at 35 weeks of pregnancy, time that our patient was born. This may have been a contributing factor to our patient's injury. The perichondrium surrounds the periphery of the growth plate and contains the ossification groove of Ranvier and the ring of LaCroix. The groove of Ranvier is wedge-shaped, surrounds the periphery of the growth plate, and is responsible for transverse growth of the growth plate. The ring of LaCroix is a dense fibrous band that provides mechanical support to the chondro-osseous junction and is continuous with the periosteum. The perichondral vessels supply the perichondrium and most peripheral aspects of the growth plate, making the central growth plate relatively vulnerable to insult [7]. Both direct and indirect injuries to the growth plate can occur; this is an example of a direct injury [8]. As the delivery of our patient was uneventful and there were no findings to support a postnatal non-accidental trauma or infection, we hypothesize that our patient underwent an occult trauma at the growth plate of the distal femur, possibly related to the process of birth. We emphasize that physeal separation with epiphyseal separation of the distal femur constitutes a rare and possibly under recognized manifestation of birth-related trauma. A lack of familiarity with this entity can engender unnecessary anxiety and lead to inefficient utilization of imaging. The entity presents a diagnostic challenge; radiographic findings can be difficult to interpret in the setting of an
References [1] Trier H. Epiphysiolysis in the distal femur as a birth injury in cesarean section. Ugeskr. Laeger 1992 May 25;154(22):1574–5. [2] Lin Rui-Lan, Liu Zhen-Jiang, Zhang Li-Jun. Neonatal distal humeral physeal separation during caesarean section: a case report and review of a literature. Int. J. Clin. Exp. Med. 2016;9(3):6882–9. [3] Raupp P, Haas D, Lovasz G. Epiphyseal separation of the distal humerus. J. Perinat. Med. 2002;30:528–30. [4] Downs DM, Wirth CR. Fracture of the distal humeral chondroepiphysis in the neonate. A case report. Clin. Orthop. Relat. Res. 1982:155–8. [5] Gigante C, Kini SG, Origo C, Volpin A. Transphyseal separation of the distal humerus in newborns. Chin. J. Traumatol. 2017;20(3):183–6. [6] Navallas M, Díaz-Ledo F, Ares J, SánchezBuenavida A, López-Vilchez MA, Solano A, et al. Distal humeral epiphysiolysis in the newborn: utility of sonography and differential diagnosis. Clin. Imaging 2013;37:180–4. [7] Rodriguez JI, Razquin S, Palacios J, Rubio V. Human growth plate development in the fetal and neonatal period. J. Orthop. Res. 1992 Jan;10(1):62–71. [8] Nguyen JC, Keegan Markhardt B, Merrow AC, Dwek JR. Imaging of pediatric growth plate disturbances. RadioGraphics 2017;37:1791–812.
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