Common Pediatric Bone Diseases- Approach to Pathological Fractures

Transcription

1 Cmmn Pediatric Bne Diseases- Apprach t Pathlgical Fractures 1. General Presentatin Teresa Liang Backgrund: It is nt uncmmn fr children t present with fractures after experiencing trauma. Hwever, children may als present with pathlgical fractures, which are fractures that ccur in abnrmal bnes and typically ccur during rutine activity r after minr trauma. It is imprtant t be able t distinguish between traumatic fractures and pathlgical fractures as the prgnsis and treatment can vary quite cnsiderably. One als MUST cnsider nn-accidental injury in the child that presents with multiple unexplained fractures. Nn-accidental injuries are discussed in a separate article n this site. These fractures will generally present as lcalized pain and tenderness ver the invlved bne. Refusal t weight bear in the yunger, nn-verbal child is als very cmmn. Pathphysilgy: Althugh there are many ptential etilgies fr weakened bne manifesting as pathlgical fractures, it is simple t divide it int three categries with cmmn etilgies: 1) Metablic bne disease- eg. Rickets 2) Bne tumurs eg. Benign tumurs (nn-ssifying fibrma and stechndrma) and malignant tumurs (stesarcma and Ewing s sarcma) 3) Cnnective tissue bne disease- eg. Ostegenesis imperfecta Metablic Bne Disease: Nrmal bne grwth and mineralizatin requires adequate calcium and phsphate. There are numerus etilgies f rickets, including nutritinal deficiencies (calcium, phsphate and vitamin D), drug induced, renal pathlgy, and tumurs. The end result and clinical manifestatins f rickets are secndary t the failure f calcificatin f the grwth plate cartilage because f a deficiency f either calcium r phsphate. Rickets is defined as deficient mineralizatin at the bne s grwth plate whereas stemalacia refers t impaired mineralizatin f the bne matrix. Rickets is relatively cmmn in children, especially thse wh have pr dietary intake, pr absrptin, increased excretin f calcium, phsphate, r vitamin D, premature infants r breast-fed infants wh are nt supplemented with vitamin D. Regardless f whether it is calcium r phsphate deficient rickets, the typical clinical findings assciated with Rickets include: Skeletal Findings (see Figure 1): Delayed clsure f the fntanelle Parietal and frntal bssing Cranitabes (sft skull bnes) Rachitic rsary (enlargement f the cstchndral junctin such that there is beading acrss the anterlateral aspects f the chest) Widening f the wrists; bwing the distal radius and ulna Prgressive bwing f the femur and tibia

2 Extraskeletal Findings (vary depending n the primary mineral deficiency): Calcipenic rickets hypplasia f dental enamel, decreased muscle tne, delayed achievement f mtr milestnes, hypcalcemic seizures, increased sweating Phsphpenic rickets dental abscesses Bne Tumrs: Tumurs, regardless f whether they are benign r malignant, can cause pathlgical fractures by grwing and replacing the nrmal tissue f bne. This results in an abnrmal, weakened bne mre prne t fractures. In children, benign bne tumurs are fairly cmmn, but are ften asymptmatic and discvered incidentally during evaluatin fr trauma r anther cnditin, and thus, the true incidence is unknwn. If they are symptmatic, they may present with lcalized pain, swelling, defrmity r a pathlgical fracture. Mst benign tumurs generally present during the secnd decade. Tw examples f cmmn benign tumurs which can present as pathlgical fractures include nn-ssifying fibrma, and steid stemas. Malignant bne tumurs accunt fr 5% f all pediatric malignancies, with the peak ccurrence between the ages f The tw mst cmmn malignant bne tumurs in children are Ewing s sarcma and stesarcma which cllectively make up 90% f the pediatric bne tumurs. Ewing s sarcma is mre cmmn within the first 10 years, and then stesarcma becmes mre cmmn. The cancers ften arise in the pelvis, femur, tibia and humerus. These can cmmnly present with symptms f pain and swelling, which may be wrse with exercise r at night, and smetimes the first signs may be due t a pathlgical fracture. Cnnective Tissue Disease: Ostegenesis imperfecta (OI) is an inherited cnnective tissue disrder cmmnly knwn as brittle bne disease which can manifest in a wide spectrum, frm mild t lethal frms. It is usually due t a deficiency f nrmal Type I cllagen, which is an rganic cmpnent necessary fr prper bne frmatin. Althugh its incidence is estimated t apprximately 0.005%, it is imprtant t include this disease in the differential diagnsis because it can present early in children as numerus and recurrent pathlgical fractures. The cmmn clinical manifestatins f OI include: Multiple and/r atypical fractures Shrt stature Sclisis Basilar skull defrmities Wrmian bnes (irregular, small bnes alng the cranial sutures) Blue sclera Hearing lss Opalescent teeth that wear quickly Increased laxity f ligaments and skin Easy bruising Accelerated steprsis

3 2. Questins t Ask Hw did the fracture ccur Hw, when, where? t determine if it was pathlgical r traumatic fracture Has the child had any previus fractures r any ther cncurrent fractures? If s, can yu describe them? t help determine pathlgical versus traumatic fracture What is the child s diet like? T determine if nutritinal deficiency Rickets may be the cause Did the child have any previus bne pain? If s, can yu describe what makes it better r wrse? Als, des it get wrse at night? T check fr ptential bne tumrs Des the child have a fever? T rule ut any ptential infectius causes r malignancies (cnstitutinal symptms - fevers, weight lss, drenching night sweats) Des the child have any ther medical histry? T rule ut a secndary cause f the bne disease D yu suspect that the child may have been abused? Wh is the primary caretaker f the child? Is the child taking any ther medicatins? 3. Differential Diagnsis fr pathlgical fracture Rickets frm Vitamin D deficiency Ostegenesis Imperfecta Renal Ostedystrphy Ostemyelitis Child abuse Preterm birth resulting in stepenia - nenates Fibrus dysplasia Ostemalacia Cpper deficiency infants: first 6 mnths Bne tumurs and cancers Chrnic Vitamin A txicity Metablic diseases leading t calcium wasting and demineralizatin Prlnged administratin f prstaglandins, gluccrticids, r methtrexate Cngenital syphilitic peristitis Hypphspatasia Juvenile Osteprsis 4. Investigatins and Management 1) Rickets: Labratry findings:

4 a. Elevated alkaline phsphatase indicatin f impaired bne mineralizeatin b. Serum phsphrus cncentratins usually lw in hypcalcemic and hypphsphatemic rickets c. Serum calcium cncentratin decreased nly in hypcalcemic rickets d. Parathyrid hrmne usually elevated in hypcalcemic rickets, but usually nrmal in hypphsphatemic rickets e. 25-OH Vitamin D lw in vitamin D deficiency f. GFR and Creatinine t determine kidney functin Radigraphic Findings: a. Ostepenia b. Metaphyseal cupping and fraying (See Figure 2) c. Physeal widening d. Enlargement f cstchndral junctin e. Bwing f lng bnes (See Figure 3) Management: a. Oral dses f 5,000-15,000 IU/day f Vitamin fr 4 weeks fr Vitamin deficient Rickets b. Optimize calcium intake fr hypcalcemic rickets c. Treat underlying primary cause f Rickets 2) Bne Tumrs (benign and malignant) Labratry Findings: a. If suspect malignancy: bld wrk including liver enzymes, CT chest, bne scan, bne bipsy, MRI f affected bne Radigraphic Findings: a. Benign: single lesin generally, sharp area f delineatin, verlying crtex intact, sclertic margins, n r simple peristeal reactin (See Figure 4) b. Malignant: multiple lesins ften, pr delineatin f lesin, lss f verlying crtex, extensive peristeal reactin, ptential sft tissue invlvement (See Figure 5)

5 Management: a. Benign: fllw up with radigraphs 4-6 mnths later b. Malignant: cmplete resectin, chemtherapy, radiatin 3) Ostegenesis Imperfecta Labratry Findings: a. Elevated levels f serum alkaline phsphatase b. Hypercalciuria magnitude reflects severity f disease c. C-terminal peptide (marker f bne frmatin) and C-telpeptide (marker f bne resrptin) can be higher Radigraphic Findings: a. Mild OI: Thin crtex and relatively few fractures with nrmal skull develpment b. Mre severe OI: hyperplastic callus frmatin (frm thickened peristeum), shrtened lng bnes with multiple fractures (See see Figure 6) Management: a. Bisphsphnates 5. Cnclusin: Children wh present with pathlgical fractures always require a thrugh evaluatin. It is imprtant t keep an pen mind as t the varius causes f pathlgic fractures and t always rule ut nn-accidental injury. 6. References: 1) Beary J, Chines A. Clinical features and diagnsis f stegenesis imperfecta. (Last Updated June 15, 2010) In: UpTDate, Tepas E (Ed), UpTDate, Wellesley, MA, ) Scheri S. Differential diagnsis f the rthpedic manifestatins f child abuse. (Last Updated Dec. 3, 2008) In: UpTDate, Wiley E (Ed), UpTDate, Wellesley, MA, ) Rauch F. Overview f Rickets in Children. (Last Updated August 11, 2010). In: UpTDate, Hppin A (Ed), UpTDate, Wellesley, MA, ) Tis J. Overview f benign bne tumrs in children and adlescents. (Last Updated September 28, 2010) In: UpTDate, Trchia, M (Ed), UpTDate, Wellesley, MA, ) Kliegman R, Behrman, Jensn H, Stantn B. Nelsn Textbk f Pediatrics, 18 th ed. Philadelphia: Saunders, 2007.

6 6) Bensn M, Fixsen J, Macnicl M. Children s Orthpaedics and Fractures, 3 rd ed. New Yrk: Springer, ) Kirpalani A, Babyn P. Imaging in Ostegenesis Imperfecta. emedicine (Last Updated August 5, 2008). Available frm [Accessed n March 5, 2011] 8) Rijn R, McHugh K. Rickets Imaging. emedicine (Last Updated March 18, 2009). Available frm [Accessed n March 5, 2011] 9) Dugani S, and Lam D. Trnt Ntes. Trnt Ntes Medical Publishing Inc ) Jenny C. Evaluating Infants and Yung Children with Multiple Fractures. Pediatrics. 2006; 118(3): ) Adam A, Dixn A. Adam: Grainger & Allisn s Diagnstic Radilgy, 5 th ed. Philadelphia: Churchill Livingstne, An Imprint f Elsevier, Acknwledgements: Written by: Teresa Liang

7 Edited by: Anne Marie Jekyll, MD (Pediatric Resident)Images Figure 1. Cmmn findings in Patients with Rickets. (Image frm Rijn R, McHugh K. Rickets Imaging. emedicine (Last Updated March 18, 2009). Available frm [Accessed n March 5, 2011])

8 Figure 2. AP and lateral radigraphs f a by with rickets. Nte the cupping and fraying f the metaphyseal regin. (Image frm Rijn R, McHugh K. Rickets Imaging. emedicine (Last Updated March 18, 2009). Available frm [Accessed n March 5, 2011])

9 Figure 3. Radigraph f a 4 year ld girl with rickets and bwing f the legs. (Image frm Rijn R, McHugh K. Rickets Imaging. emedicine (Last Updated March 18, 2009). Available frm [Accessed n March 5, 2011]) Figure 4. Benign Bne Tumrs. Left: Intracrtical steid stema f a femral shaft with a radilucent area and perifcal stesclersis. Right: Nnssifying fibrma in distal tibia displaying the characteristic scallped sclertic margin (Adapted frm Adam A, Dixn A. Adam: Grainger & Allisn s Diagnstic Radilgy, 5 th ed. Philadelphia: Churchill Livingstne, An Imprint f Elsevier, 2008)

10 Figure 5. Malignant Bne Tumrs. Left: Ostesarcma with a mixed sclertic and lytic lesin f the humerus, extending t the sft tissues but sparing the grwth plate, ntice the pr delineatin. Right: Ewing s sarcma mixed lytic and sclertic lesin f third metatarsal bne with peristeal reactin. (Adapted frm Adam A, Dixn A. Adam: Grainger & Allisn s Diagnstic Radilgy, 5 th ed. Philadelphia: Churchill Livingstne, An Imprint f Elsevier, 2008)

11 Figure 6. Frntal Radigraph f the frearm f a female adlescent with type I (mild) OI which shws steprsis, bwing defrmities, a healed ulnar fracture and grwth recvery lines in the distal radius. (Image frm Kirpalani A, Babyn P. Imaging in Ostegenesis Imperfecta. emedicine (Last Updated August 5, 2008). Available frm [Accessed n March 5, 2011])