Pathologic Fractures in Children

1. Pathologic Fracturesin Children Joshua Klatt, MD Original Author: Steven Frick, MD; March 2004 1st Revision: Steven Frick, MD; August 2006 2nd Revision: Joshua Klatt, MD; January 2010

2. Pathologic Fracture =Fracture through abnormal bone

3. Pathologic Fractures Abnormal bone lacks normal biomechanic and viscoelastic properties Intrinsic processes Localized - Bone cyst, neoplasm, etc. Systemic - OI, osteopenia, osteopetrosis, rickets, etc. Extrinsic processes Radiation, biopsy, defects after plate removal, etc.

6. The orthopaedic surgeon may be the first to have opportunity to make the diagnosis. (malignancy, metabolic disease, etc.) Often Need to Do More than Treat the Fracture

7. Differ from fractures in normal bone in that one must take into account� Etiology Natural history Treatment of underlying abnormality Must treat both fracture and underlying cause! Often Need to Do More than Treat the Fracture

8. Minor or no trauma? Less than anticipated for fracture pattern Any antecedent pain? Only with activity vs. night pain Recent illness? Weight loss? Fevers? History

9. History Ask about growth and development Dietary habits Kidney disease May suggest rickets or renal osteodystrophy, etc. Thyroid disease Family history Dysplasias, metabolic disorders, osteoporosis, neuromuscular disorders, etc.

10. Ask about prior malignancies, even in the child! Families will not always volunteer this information History

11. Look for soft tissue mass vs. fracture hematoma Other systems- skin, lymphatics, solid organs Height - weight percentiles Physical Exam

13. CBC with differential ESR Calcium (ionized), Phosphorus, Alkaline phosphatase Bun/Cr Lab Tests

14. Osteopenia Physeal width (rickets) Soft tissue calcifications Presence of mass Any periosteal reaction RadiographsBe suspicious!

15. Is pathology� Localized and isolated? Polyostotic? Generalized to entire skeletal system? A generalized condition with skeletal manifestations? Radiographs

16. Where is lesion located? What is lesion doing to bone? What is bone doing to lesion? Are there clues to type of lesion? Enneking�s 4 Questions

17. Size Margination Cortex Soft tissue mass Benign vs. MalignantMankin�s Criteria

18. Benign bone lesion Malignant bone lesion Infection Metabolic bone disease Categorize/Make Diagnosis Skeletal dysplasia Neuropathic Osteopenia-disuse Overuse

19. Treatment Union best achieved by correcting biomechanical and biological environment While chemo & radiation slow healing, they provide a beneficial response in presence of rapidly dividing malignant cells

20. Not true neoplasms, etiology unknown Often loculated and not truly �unicameral� Most frequently contain serous fluid Usually metaphyseal Proximal humeral & femoral lesions account for 94% of all lesions Most in patients 3-14 years old, average age 9 Males > females (2:1) Simple Bone Cyst(Unicameral Bone Cyst)

21. Fallen leaf sign (or fragment) is virtually pathognomonic Treatment Fracture heals; cyst persist in 50-90% Humerus - treat fracture, address lesion after fracture is healed, if felt to be necessary Displaced proximal femur #s - Open reduction, grafting and rigid fixation, unless very young Posterior facet #s of the calcaneus - Open reduction, if necessary with grafting and fixation SBC Pathologic Fracture

22. Controversial! Open Management Curettage/graft Bone graft substitutes Minimally invasive techniques (injections) Steroid injections Bone marrow injections All seem to work with similar frequency (~90%) But can be recurrence with any of them! Disrupt hydraulics- puncture, screw, wires, rods, etc. SBC Treatment

23. 18 ga spinal needle C-arm Serous fluid, straw colored 2nd needle- vent Depo-Medrol 160 mg Watch for immediate drainage from large outflow veins May need multiple injections SBC Injection

25. SBC - Risk Factors for Recurrence Only reliable predictor of treatment success is age of the patient > 10 yrs heal ~ 90% of time < 10 yrs heal ~ 60% of time Most cysts tend to heal after skeletal maturity

26. SBC

27. Expansile Often wider than physis Eccentric Aggressive at margins Aneurysmal Bone Cyst(ABC)

28. Symptoms usually present for < 6 months Lesion may attain considerable size before recognized Can exist as� primary bone lesion (70%) secondary lesion in other osseous conditions (30%) Pelvic lesions account for 50% of all flat bone lesions (~10% total) Treatment is difficult due to inaccessibility and integrity of acetabulum Aneurysmal Bone Cyst(ABC)

29. ABC

30. ABC

31. ABC

35. Curettage and bone graft +/- internal fixation ? Injection of fibrosing agent (Ethibloc, Ethicon, etc.) is controversial High recurrence ABC

36. Nonossifying Fibroma(NOF) Benign, nonosteoid-producing lesion Usually found in metaphyses of long bones Prediliction for lower extremities Usually asymptomatic Often incidental radiographic finding It is speculated that up to a 1/3 of children may have at least a minor NOF/fibrous cortical defect Almost always regress by early 20�s

37. Nonossifying Fibroma(NOF) Most treated non-op! Let fracture heal, excellent healing potential Most NOF�s persist after #, but heal by skeletal maturity If fractures once with minimal trauma, potential risk to fracture again unless bone changes with healing If necessary, treat with curettage/bone graft

39. NOF - Prophylactic Bone Graft? Are size parameters predictable? Arata and Peterson, JBJS 1981 Review of 23 fractures over 50 years Suggest tx if greater than 50% diameter, >33 mm length Easley and Kneisl, JPO 1997 Review of 22 lesions, many without #s, over 25 years Only included large lesions (above criteria) Only 41% had fractures, no refractures Suggest prophylactic surgery not necessary in many Criteria for surgery still not well defined

40. Fibrous Dysplasia Developmental disorder of bone, etiology unclear May be mutation leading to activation of c-fos oncogene Can be associated with endocrine disorders (McCune-Albright syndrome) Can be mono- or polyostotic Usually affects adolescents and young adults Many solitary asymp lesions found incidentally Most do not require intervention If increased fracture risk, treat with curettage, bone grafting and sometimes internal fixation

41. Fibrous Dysplasia Surgical treatment for: Progressive lesions Large lesions with pain Pain & deformity suggest microfractures Failure of conservative treatment Less successful in: Younger patients Larger and proximal femoral lesions Polyostotic disease, esp McCune-Albright syndrome

42. Fibrous Dysplasia Lesions are never eradicated, even with grafting All grafts are eventually absorbed into dysplastic bone Cortical grafts at a much slower rate and therefore recommended for weight-bearing bones Enneking suggested cortical struts alone for femoral neck Fixation in WB bones seems to improve outcome in children

44. 3 Years Postop

45. Fibrous Dysplasia Consider other sites (polyostotic disease) Bone scan to help identify other lesions Although lesions usually revealed on scan, a �cold� bone scan does not rule out lesions For extensive involvement (McCune-Albright) consider intramedullary fixation/splinting

46. 11 yo male � fem neck path fx, nondisplaced. Fibular allograft (neck) and titanium elastic nails (subtroch and shaft)

47. 13 yrs old � 2 years postop. lesions in Rt. femur and tibia. No pain in hip, in karate.Fibular graft gone. Treat painful tibia? Nail? Pamidronate?

49. Prophylactic Treatment of Fibrous Lesions (NOF /FD) Any mechanical pain? Location and size - relative issues Supracondylar femur, proximal femur more worrisome Pharmacologic approach (bisphosphonates) for painful fibrous dysplasia � some reported successes

50. Abnormal type I collagen COL1A and COL2A defects Location and type of mutation in collagen molecule determine phenotype (Sillence) Severe types (II-IV)- multiple fractures prior to skeletal maturity Also find joint laxity, gray-blue sclera, dentogenesis imperfecta, premature deafness, kyphoscoliosis & basilar invagination Lower extremity > upper extremity Osteogenesis Imperfecta(OI)

51. Early onset (fxs prior to walking)- more fractures (2x) Direct relationship between increased bone turnover and severity of disease Closed tx- limit immobilization time to reduce further osteopenia IM fixation often needed Also used for realignment surgery and to decrease fracture risk OI

53. OI

54. OI � Olecranon Fx

55. OI- New Methods Minimize disuse osteoporosis Early IM fixation New design Expandable nails Bisphosphonates Increase bone density Osteoclast inhibitors Decrease fracture rate Oral and IV effective

56. Ollier�s Disease (Multiple Enchondromas) Linear masses of cartilage in metaphyseal and diaphyseal regions of long bones Asymmetric, often unilateral Usually sporadic occurrence Pathologic fx may occur

58. Infection should always be in differential of pathologic fractures However, pathologic fracture uncommon in osteomyelitis Often delayed diagnosis More common in weight-bearing bones (i.e. femur, tibia) Involucrum may be supportive of diagnosis Osteomyelitis

59. Post-Irradiation Steroids Chemotherapy (MTX) Iatrogenic Osteoporosis

61. Myelomeningocele, paraplegics, sensory neuropathies, etc. Exam frequently reveals warm, erythematous, swollen joint Often mistaken for infection, DVT, tumor Neuropathic Fractures

64. Usually through normal bone subjected to abnormal stresses May be mistaken for more serious pathology (esp. longitudinal stress fxs) History of recent increased activity Proximal tibia, distal fibula, metatarsals most common Treat with rest, which can be challenging to achieve Stress Fractures

66. Stress Fractures Can occur through pathologic bone Congenital abnormalities, metabolic disorders (osteoporosis, osteomalacia)

67. Congenital Tibial Dysplasia

68. Referral to musculoskeletal oncologist Requires complete staging Biopsy needed - follow proper �rules� for biopsy Notify pathologist of fracture Avoid fracture callus (histology may look malignant) Biopsy soft tissue mass Malignant Appearing Pathologic Fracture

70. Malignant Pathologic Fractures May need immediate amputation Osteosarcoma some fx may heal during neoadjuvant chemotherapy Ewing�s closed immobilization chemotherapy

73. Pediatric Pathologic Fxs Be suspicious - scrutinize every fracture film! Most frequently a benign process Make the diagnosis to guide treatment Appropriate referral / workup for suspected malignancy Prophylactic treatment for benign lesions on an individual basis

74. Bibliography Enneking, et al. The surgical staging of MSK sarcoma. JBJS 62-A:1027-1030, 1980. Enneking. A System of Staging MSK Neoplasms. CORR 204:9-24, 1986. Gebhardt, Ready & Mankin. Tumors about the knee in children. Clin Orthop 255:86-110, 1980. Baig & Eady. Unicameral (Simple) Bone Cysts. South Med J. 99(9):966-76, 2006. Spence et al. Solitary unicameral bone cyst: treatment with freeze-dried crushed cortical-bone allograft. JBJS-A 58:636-41, 1976 Cottalorda & Bourelle, Current treatments of primary ABCs. J Pediatr Orthop B 15:155-67, 2006. Cottalorda et al. Aneurysmal Bone Cysts of the Pelvis in Children. J Pediatr Orthop. 25:471-5, 2005. Bur, et al. Fluid-fluid levels in a unicameral bone cyst: CT and MR findings. J Comput Assist Tomogr 17:134-6, 1993. Papagelopoulos, et al. Treatment of aneurysmal bone cysts of the pelvis and sacrum. JBJS-A 83:1674-81, 2001. Adamsbaum et al. Intralesional Ethibloc injection in primary ABCs. Skeltal Radiol. 32:559-66, 2003. Varshney et al. Is Sclerotherapy Better than Intralesional Excision for treating ABCs. CORR epib 2009. Betsy et al. Metphyseal fibrous defects. J Am Acad Orthop Surg. 12:89-95, 2004. Arata et al. Pathological fxs through NOFs. JBJS-A. 63:980-8, 1981. Easley & Kneisl. Pathologic fxs through NOFs: is prophylactic treatement warranted? J Pediatr Orthop 17:808-13, 1997. Parekh et al. Fibrous Dysplasia. J Am Acad Orthop Surg. 12:303-13, 2004. Enneking & Gearen. Fibrous dysplasia of the femoral neck: Treatment by cortical bone-grafting. JBJS-A 68:1415-22, 1986 Stephenson et al. Fibrous dysplasia: An analysis of options for treatment. JBJS-A 69:400-9, 1987. DiCaprio & Enneking. Fibrous dysplasia. Pathophysiology, evaluation and treatment. JBJS-A87:1848-64, 2005. Sillence et al. Genetic heterogeneity in osteogenesis imperfecta. J Med Gen. 16:101-16, 1979.

75. Bibliography Van Dijk et atl. Classification of Osteogenesis Imperfecta revisited. Eur J Med Genet 53:1-5, 2010. D�Astous & Carroll: Connective Tissue Diseases, in Vaccaro (ed): OKU 8. Rosemont, IL, AAOS, 2005. Phillipi et al. Bisphosphonate therapy for OI. Cochrane Database Syst Rev 8(4), 2008 Panigrahi et al. Response to zolendronic acid in children with type 3 OI. J Bone Biner Metab, Feb 4, 2010. [Epub ahead of print] Lewis et al. Benign and malignant cartilage tumors. Instr Course Lect 36:87-114, 1987. Taylor et al. Childhood osteomyelitis presenting as a pathologic fracture. Clin Rad 63:348-51, 2008. Gelfand, et al. Path fx in acute osteo of long bones secondary to communit acquired MRSA? Am J Med Sci 332:357-60, 2006. Heyworth & Green. Lower extremity stress fractures in pediatric and adolescent athletes. Curr Opin Pediatr 20:58-61, 2008. Sakamoto et al. Congenital pseudarthrosis of the tibia: analysis of the histology and the NF1 gene. J Orthop Sci 12:361-5, 2007.

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