title: Dorsal defect of the patella with fracture in a teenager.
abstract: We report the case of a young boy who presented a dorsal defect of the patella (DDP) with fracture after a small sport trauma. The patient's parents (professional of health care) had been warned on a possible tumoral disease in a previous consultation and claimed for an accurate diagnosis. Although fracture is rarely reported in DDP, the radiographic image strongly suggested this condition; nevertheless, the diagnosis accuracy requested by the parents lead to indicate a biopsy that showed irregular fragments of laminar bone and hyaline cartilage islands similar to articular cartilage compatible with a non-specific developmental ossification defect. The lytic defect was filled with morselized cancellous bone graft, the fracture having a normal consolidation. With a follow-up of 4 years, the patient is asymptomatic, and the radiological morphology of the patella is normal. Although DDP is accepted to be a radiologically well-defined condition, images may perhaps not get accuracy enough for diagnosis and biopsy may be indicated by clinical and radiological features different than the typical ones. Although fracture is rarely reported in case of DDP, it has not to be considered as indicative of tumor or malignancy.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, University Clinic of Navarre, School of Medicine, C/Pío XII 36, Pamplona, Spain. cvillas@unav.es
authors.forename: Carlos
authors.initials: C
authors.lastname: Villas
authors.forename: Juan
authors.initials: J
authors.lastname: Pons-Villanueva
mesh_terms: D000293:Adolescent; D018771:Arthralgia / Q000209:etiology; D001265:Athletic Injuries / Q000150:complications; D001706:Biopsy; D001859:Bone Neoplasms / Q000175:diagnosis; D016025:Bone Transplantation; D003937:Diagnosis, Differential; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D051457:Hyaline Cartilage / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D010012:Osteogenesis; D010014:Osteolysis / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D010329:Patella / Q000000981:diagnostic imaging / Q000293:injuries* / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed
references.citation: Arthroscopy. 1993;9(2):164-9
references.pmid: 8461074
references.citation: J Pediatr Orthop. 1994 Sep-Oct;14(5):603-7
references.pmid: 7962501
references.citation: Arch Orthop Trauma Surg. 2002 Nov;122(8):466-8
references.pmid: 12442186
references.citation: J Bone Joint Surg Br. 1974 Feb;56(1):139-41
references.pmid: 4818841
references.citation: J Bone Joint Surg Am. 1966 Oct;48(7):1359-66
references.pmid: 5223756
references.citation: Clin Orthop Relat Res. 2001 Aug;(389):35-46
references.pmid: 11501820
references.citation: Radiology. 1979 Feb;130(2):333-6
references.pmid: 760144
references.citation: J Bone Joint Surg Am. 1968 Sep;50(6):1230-2
references.pmid: 5675405
references.citation: Skeletal Radiol. 1996 Aug;25(6):588-91
references.pmid: 8865498
references.citation: JAMA. 1977 Sep 12;238(11):1179-80
references.pmid: 578165
references.citation: Skeletal Radiol. 1998 Jan;27(1):40-2
references.pmid: 9507610
references.citation: AJR Am J Roentgenol. 1982 Aug;139(2):339-40
references.pmid: 6979889
references.citation: J La State Med Soc. 2005 Jan-Feb;157(1):13-4
references.pmid: 15887661
references.citation: AJR Am J Roentgenol. 1989 Jul;153(1):103-6
references.pmid: 2735276
references.citation: Acta Orthop Scand. 1976 Oct;47(5):566-9
references.pmid: 998194
references.citation: J Bone Joint Surg Am. 1984 Jan;66(1):116-20
references.pmid: 6690432
references.citation: Rev Chir Orthop Reparatrice Appar Mot. 2003 Jun;89(4):361-6
references.pmid: 12844041
references.citation: Arthroscopy. 2002 Jan;18(1):32-7
references.pmid: 11774139
references.citation: J Chin Med Assoc. 2004 Jul;67(7):369-72
references.pmid: 15510936
references.citation: Clin Orthop Relat Res. 1997 Mar;(336):199-204
references.pmid: 9060506
references.citation: Eur Radiol. 2001;11(7):1136-9
references.pmid: 11471600
references.citation: Skeletal Radiol. 1987;16(4):304-11
references.pmid: 3112959
references.citation: Pediatr Radiol. 1976 Aug 20;4(4):238-42
references.pmid: 15822879