RESUMO Objetivo: Avaliar os resultados dos pacientes submetidos a tratamento cirúrgico artroscópico da epicondilite lateral (EL) refratária depois da falha no tratamento conservador. Métodos: Estudo retrospectivo que incluiu 104 pacientes submetidos a desbridamento artroscópico do tendão extensor radial curto do carpo (ERCC) para tratamento de EL. Os pacientes foram avaliados pelo escore de DASH, pela classificação visual analógica de dor (EVA) e pelo Short-Form 36 (SF36). A média da idade foi de 46,9 anos (variação de 30 a 69 anos). O tempo de sintomas foi de 2,1 anos (variação de 6 meses a 10 anos). O seguimento médio foi de 34,4 meses (variação de 6 – 68 meses). Resultados: A média dos escores pós-operatórios foi de: 20,67 pontos no DASH; 1,8 pontos no EVA de repouso, sendo 48 (46%) sem dor, 40 (38%) com dor leve, 13 casos (13%) com dor moderada e 4 (4%) com dor intensa; 4,7 pontos no EVA em atividade, sendo 21 (20%) sem dor, 21 (20%) com dores leves, 35 (34%) com dores moderadas e 27 (26%) com dores intensas; e SF-36 de 66,8. Dos 23 pacientes em prática constante de esporte ou com maior demanda física nos membros superiores, 17 (74%) conseguiram retornar ao mesmo nível. Não observamos complicações significativas exceto por 3 (2,8%) casos de infecção pós-operatória superficial. Conclusão: O tratamento artroscópico para EL recalcitrante do cotovelo é eficaz e seguro, apresentando resultados positivos. Nível de Evidencia IV, Série de Casos.

ABSTRACT Objective: To evaluate the outcomes of patients that underwent arthroscopic surgery for lateral epicondylitis (LE), after failed conservative treatment. Methods: One hundred four patients with LE treated with arthroscopic debridement of the extensor carpi radialis brevis (ECRB) tendon were enrolled in this retrospective study. They were evaluated using Disabilities of the Arm, Shoulder and Hand (DASH) score, Visual Analogue Scale (VAS) and Short Form Health Survey (SF-36) scale. Mean age at surgery was 46.9 years. Duration of symptoms was 2.1 years (range: 6 m to 10 yrs.). Mean follow-up was 34.4 months (range: 6 to 68 m). Results: Mean postoperative scores were: 20.67 points on the DASH; 1.8 points on the VAS at rest, with 48 cases (46%) without pain, 40 (38%) with mild pain, 13 (13%) with moderate pain and 4 (4%) with severe pain; 4.7 points on the VAS in activity, with 21 (20%) without pain, 21 (20%) with mild pain, 35 (34%) with moderate pain and 27 (26%) with severe pain; and SF-36 was 66.8 points. Of the 23 patients who practiced sports regularly or with higher physical demand from the upper limbs, 17 (74%) were able to return to the same activity at the same level. No significant complications were observed postoperatively, except for 3 (2.8%) cases of postoperative superficial infection. Conclusion: Surgical treatment with arthroscopy for recalcitrant LE is effective and safe, presenting positive outcomes in the studied patients. Level of evidence IV, Case Series.

RESUMO Objetivos: O leiomiossarcoma primário do osso (LPO) é um tumor ósseo maligno raro, considerado uma variante do sarcoma de células fusiformes (SCF). O objetivo deste estudo foi fazer uma análise clínico-patológica e dos fatores de prognóstico dos pacientes diagnosticados com LPO tratados em uma instituição única. Métodos: Foram analisados retrospectivamente os prontuários de 22 pacientes com diagnóstico confirmado de LPO. Os dados coletados foram: idade, sexo, tamanho e localização do tumor, grau histológico, estádio da doença e as características histopatológicas. A média de idade foi 45,5 anos (de 17 a 73 a). A localização foi: membro superior (27,3%), membro inferior (68,2%) e pelve (4,5%). Os pacientes apresentaram alto grau em 90,9% dos relatos. As margens foram livres em 77,3% dos casos. Os relatos histológicos descrevem células sarcomatosas finas e compridas, arranjadas em fascículos, com aumento da vascularização e sem produção de matriz osteoide ou condral. No estudo imuno-histoquímico, a actina do músculo liso e a desmina foram positivas em todos os casos. Resultados: O tempo médio de seguimento foi 73,5 meses (de 5,3 a 331,1 m). Dos pacientes, 22,7% apresentaram recorrência local (RL). Metástase à distância (MD) foi reportada em 9 (40,9%) pacientes. O único local de MD foi o pulmão. O tempo médio de sobrevida em 5 anos foi de 59,1%. Os fatores preditivos de sobrevida global foram: RL e MD. Conclusão: O LPO é um tumor ósseo maligno extremamente raro que tem uma taxa maior de MD, com uma sobrevida global similar aos outros sarcomas ósseos. Nível de Evidencia IV, Série de Casos.

ABSTRACT Objective: Primary leiomyosarcoma of bone (PLB) is a rare type of malignant bone tumor considered as a variant of the spindle cell sarcomas (SCS). The objective of this study was to analyze the clinicopathologic and the prognostic factors of patients with PLB treated at a single institution. Methods: We retrospectively reviewed the records of 22 patients with pathologically confirmed PLB. The data collected were: age, sex, tumor size and location, grade and stage of the disease and histopathologic features. Mean age was 45.5 years (range, 17 to 73 y). Location was: upper limb (27.3%), lower limb (68.2%) and pelvis (4.5%). Patients had high grade in 90.9% of the reports. Margins were negative in 77.3% of the cases. Histological reports describe spindly sarcomatous cells arranged in fascicles with increased vascular formation without osteoid or chondroid matrix production. On immunohistochemistry, smooth muscle actin and desmin where positive in all cases. Results: Mean follow-up time was 73.5 months (range, 5.3 to 331.1 m). We found 22.7% of local recurrence (LR). Distant metastasis (DM) was reported in 9 (40.9%) patients. Lung metastasis was the only DM affected site. Overall survival (OS) rate in 5 years was 59.1%. Predictors of OS were LR and DM. Conclusions: PLB is an extremely rare malignant bone tumor that has a higher rate of DM and similar OS prognosis compared with other bone sarcomas. Level of Evidence IV, Case Series.

RESUMO Objetivos: O mixofibrossarcoma (MFS) é um sarcoma de partes moles (SPM) frequente em idosos, que afeta os membros. O objetivo foi analisar os fatores prognósticos e os desfechos dos pacientes diagnosticados com MFS em uma única instituição. Métodos: Foram analisados retrospectivamente prontuários de 75 pacientes com MFS. Comparamos idade, sexo, tamanho e localização do tumor, grau histológico e o estádio da doença. A media da idade foi 49,7 anos (faixa de 1 a 88 anos). A localização foi: membro superior (25,4%), membro inferior (66,6%) e pelve (8%). Dos tumores, 46,7% foram de alto grau. As margens foram negativas em 76%. A análise de regressão de Cox bivariada foi usada para determinar as associações entre os fatores clínicos e de tratamento com a recorrência local (RL). Resultados: A media do acompanhamento foi 30,7 meses (faixa de 1,8 a 383,8 meses) e 26,7% dos pacientes tiveram RL. Metástases a distância (MD) foram relatadas em 27 (36%) pacientes. O local mais comum de MD foi o pulmão (92,6%). A sobrevida geral (SG) com metástase foi 21,2 meses (faixa de 4,8 a 114,8 meses). Os fatores preditivos de SG foram grau, RL (razão de probabilidades [HR] 5,13, intervalo de confiança de 95%, 2,15-12,24, P < 0,001) e MD (HR 540,97, intervalo de confiança de 95%, 5,04-58.112,03, P < 0.001). Conclusões: Grau histológico do tumor, margens comprometidas, RL e MD foram fatores preditivos de pior prognóstico da SG. Nível de Evidencia IV, Série de Casos.

ABSTRACT Objective: Myxofibrosarcoma (MFS) is a common soft tissue sarcoma (STS) that affects the extremities in elderly patients. The objective was to analyze the prognostic factors and outcomes of patients with MFS treated at a single institution. Methods: We retrospectively reviewed the records of 75 patients with MFS. We compared age, sex, tumor size and location, grade and stage of the disease. Median age was 49.7 years (range, 1 to 88 y). Location: upper extremity (25.4%), lower extremity (66.6%) and pelvis (8%). Patients had high-grade tumors in 46.7% of the reports. Margins were negative in 76% of the cases. Bivariate Cox regression analysis was used to determine associations between clinical and treatment factors with local recurrence (LR). Results: Median follow-up time was 30.7 months (range, 1.8 to 383.8 m). We found 26.7% of LR. Distant metastasis (DM) was reported in 27 (36%) patients. Lung was the most common site of DM, reported in 92.6% of patients. Overall survival (OS) with metastasis was 21.2 months (range, 4.8 to 114.8 m). Predictors of OS were grade, LR (hazard ratio [HR] 5.13, 95% confidence interval, 2.15-12.24, P <0.001), and DM (HR 540.97, 95% confidence interval, 5.04-58112.03, P< 0.001). Conclusions: Tumor grade, LR, positive margins and DM were significant predictors of poor OS prognosis. Level of Evidence IV, Case Series.

RESUMO Objetivo: A causa da instabilidade anterior do ombro não é totalmente esclarecida e o tratamento cirúrgico é controverso. O objetivo deste estudo foi avaliar o resultado dos pacientes submetidos à técnica de Latarjet artroscópica com endobuttons. Métodos: Estudo retrospectivo de 26 pacientes submetidos à técnica de Latarjet artroscópica com endobuttons para tratamento de instabilidade anterior do ombro. Foram incluídos pacientes com instabilidade glenoumeral anterior, falha no procedimento de Bankart ou Instability Severity Index Score (ISIS) maior ou igual a 6. Foram avaliados mediante DASH, UCLA, Rowe, Escala Visual Analógica de dor (EVA) e pelo Short-Form 36 (SF36). Avaliamos também a posição correta e a consolidação do enxerto. Resultados: A média de idade foi de 31,5 anos (16 a 46). Os sintomas antes da cirurgia foram de 1,7 anos (1 mês a 10 anos). Seguimento médio de 14,3 (6 – 24) meses. A média dos escores pós-operatórios foi de 10 pontos no DASH; 1,6 pontos na EVA sendo 23 (88%) dores leves e 3 (12%) dores moderadas; Rowe de 89, UCLA de 32; SF-36 de 78. O posicionamento foi correto em 25 (96%) casos e consolidou em 23 (88%). Tivemos 2 casos de fratura (7%) e de migração pós-operatória do enxerto (7%). Conclusão: A cirurgia de Latarjet artroscópica com endobuttons é eficaz e segura, produzindo bons resultados funcionas. Nível de Evidencia IV, Série de Casos.

ABSTRACT Objective: The cause of anterior shoulder instability is not fully understood and surgical management remains controversial. The objective of this study was to evaluate the results of patients undergoing arthroscopic Latarjet procedure with endobuttons. Methods: A retrospective study of 26 patients undergoing arthroscopic Latarjet procedure with endobuttons to treat anterior shoulder instability. Patients with previous glenohumeral instability, failure of Bankart procedure or Instability Severity Index Score (ISIS) greater than or equal to 6, were included. Patients were assessed by: DASH, UCLA, Rowe, Visual Analog Scale (VAS) of pain and Short-Form 36 (SF36) scores. Correct position and consolidation of the graft were evaluated. Results: Mean age was 31.5 years (16 to 46). Preoperative duration of symptoms was 1.7 years (1 month to 10 years). Mean follow-up was 14.3 (6 to 24) months. Mean postoperative scores were: 10 points in DASH; 1.6 in VAS, where 23 (88%) patients experienced mild pain and 3 (12%) moderate pain; 89 in Rowe; 32 in UCLA and 78 in SF-36. Positioning of the graft was correct in 25 (96%) cases, and was consolidated in 23 (88%). We had two cases of graft fracture (7%) and postoperative migration (7%). Conclusion: Surgical treatment using arthroscopic Latarjet with endobuttons is safe and effective, producing good functional outcomes in patients. Level of Evidence IV, Case Series.

RESUMO Objetivo: O adamantinoma representa menos de 1% das neoplasias ósseas primárias. Afeta predominantemente a tíbia, em pacientes do sexo masculino entre a segunda e terceira décadas da vida. O objetivo deste trabalho é obter informação epidemiológica e clínica dos pacientes com adamantinoma da tíbia, tratados mediante cirurgia entre 1989 e 2016. Métodos: Série retrospectiva de sete pacientes com diagnóstico de adamantinoma da tíbia, tratados cirurgicamente no serviço de oncologia ortopédica do nosso hospital. A informação foi obtida dos relatos clínicos e patológicos do instituto. Resultados: Um total de 2870 prontuários com relatos anatomopatológicos foram revisados. Sete casos de pacientes com adamantinoma na tíbia foram encontrados. A média de idade foi de 28,5 anos (17-49). Encontramos predominância do sexo feminino (71,4%). O lado mais afetado foi o esquerdo, com quatro (57,1%) casos. A biópsia diagnosticou adamantinoma em 57,1% dos casos e o diagnóstico dos outros casos foi definido após exame da peça cirúrgica. Todos os pacientes receberam tratamento cirúrgico como terapia definitiva. Não foram reportadas margens comprometidas. Nenhum paciente apresentou recorrência local (RL). Dois pacientes apresentaram metástase à distância (MD). Conclusão: O prognóstico de sobrevida do adamantinoma da tíbia é alto. Apresenta taxas baixas de RL e MD. A cirurgia com ampla ressecção do tumor é o tratamento de escolha. Nível de Evidência IV, Série de Casos.

ABSTRACT Objective: Adamantinoma accounts for less than 1% of the primary bone neoplasms. The tibia is the most affected bone and it is predominant in male patients between the second and third decades of life. The objective of this study is to obtain epidemiological and clinical information on patients with adamantinoma of the tibia treated surgically between 1989 and 2016. Methods: Retrospective series of seven patients diagnosed with adamantinoma of the tibia that underwent surgery at the orthopedic oncology service of our hospital. The information was obtained from the medical records and histopathological reports of our institution. Results: A total of 2870 medical records with histological reports were evaluated. Seven cases of adamantinoma of the tibia were included. The mean age was 28.5 (17-49) years. We found a predominance of females (71.4%) and the most affected side was the left one, with four cases (57.1%). The biopsy revealed bone adamantinoma in four (57.1%) patients, while the diagnosis of the other patients was confirmed after the histological examination of the surgical specimen. All the patients underwent surgery as definitive treatment. No positive margins were reported. No local recurrence (LR) was reported and two patients had distant metastasis (DM). Conclusion: The prognosis of survival in cases of adamantinoma of the tibia is high. The rates of LR and DM were low. Surgical treatment with extensive tumor resection is the treatment of choice. Level of Evidence IV, Case Series.

RESUMO Objetivo: O tumor desmoide extra-abdominal (TDE) é raro, formado por proliferação de fibroblastos. Apesar de ser um tumor benigno, é localmente agressivo e tem comportamento clínico imprevisível. O objetivo desta pesquisa é apresentar os resultados clínicos obtidos nos pacientes com TDE, tratados cirurgicamente entre 1995 e 2016. Métodos: Trata-se de uma série retrospectiva de 23 pacientes com diagnóstico anatomopatológico de TDE, tratados cirurgicamente no serviço de oncologia ortopédica de nosso hospital. A informação foi obtida dos relatos clínicos e patológicos do instituto. Resultados: Um total de 223 prontuários com relato anatomopatológico foi revisado. Apenas 23 casos de TDE foram incluídos no presente estudo. A média de idade foi de 22,5 anos. Doze (52,2%) casos se localizaram nos membros inferiores, sete (30,4%) casos nos membros superiores e quatro (17,4%) casos se localizaram no dorso. Cinco (21,7%) casos tinham tamanho < 5 cm e 18 (78,3%) casos tinham tamanho > 5 cm. Todos os pacientes receberam tratamento cirúrgico como terapia definitiva no instituto. Doze (52,2%) casos apresentaram margens livres (ML) e onze (47,8%) casos tinham margens comprometidas (MC). A recorrência local (RL) ocorreu em onze (47,8%) pacientes. Conclusão: O comprometimento da margem cirúrgica foi o único fator de prognóstico encontrado para a RL do TDE. Nível de Evidência IV, Série de Casos.

ABSTRACT Objective: Extra-abdominal desmoid tumor (EDT) is a rare condition, caused by proliferation of fibroblasts. Despite being a benign tumor, it is locally aggressive and has unpredictable clinical behavior. The objective of this study is to present the clinical outcomes of patients with EDT treated surgically between 1995 and 2016. Methods: This is a retrospective series of 23 patients with histopathological diagnosis of EDT that underwent surgery at the orthopedic oncology service of our hospital. The information was obtained from the institute's clinical and pathology reports. Results: A total of 223 medical records with histopathological reports were evaluated. Only 23 cases of EDT were included in the present study. The mean age was 22.5 years. Twelve (52.2%) patients had the tumor on the lower limbs, seven (30.4%) on the upper limbs and four (17.4%) cases were reported on the back. Five (21.7%) patients had tumors measuring less than 5 cm, while eighteen (78.3%) patients had tumors measuring more than 5 cm. All patients underwent surgery as the definitive treatment in our institute. Twelve (52.2%) cases presented negative margins (NM) and eleven (47.8%) cases had positive margins (PM). Local recurrence (LR) occurred in eleven (47.8%) patients. Conclusion: Impairment of the surgical margin was the only prognostic factor found for LR of EDT. Level of Evidence IV, Case Series.

RESUMO Objetivos As vantagens da utilização do Cateter Central de Inserção Periférica (CCIP) no ambiente hospitalar faz com que esse cateter ocupe uma posição de destaque na terapia intravenosa. Este trabalho relata o uso do CCIP nos pacientes do Instituto de Ortopedia e Traumatologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo (IOT-HC-FMUSP) nos últimos 10 anos. Métodos Trata-se de um estudo retrospectivo, no qual foram analisados 1057 prontuários. Foram incluídos 1023 prontuários de pacientes submetidos à inserção do CCIP, em que foram analisados a veia puncionada, diagnóstico do paciente, tempo em que o paciente permaneceu com o cateter, complicações e posicionamento da ponta do CCIP. Resultados Setecentos e vinte CCIPs (70,4%) foram considerados adequadamente posicionados. O tempo médio de utilização do cateter foi de 34,3 dias. A veia basílica foi a mais utilizada em 528 (51,6%) pacientes. Cento e cinquenta e sete (15,4%) cateteres foram removidos devido a complicações. Nenhum caso de trombose ou infecção relacionada ao cateter foi observada. Oitocentos e sessenta e seis (84,6%) permaneceram com o CCIP até o final do tratamento. Conclusão O CCIP é um dispositivo intravenoso seguro e pode ser utilizado para terapia intravenosa de média e longa duração em pacientes ortopédicos hospitalizados ou desospitalizados. Nível de Evidencia IV; Série de casos.

ABSTRACT Objectives The advantages of using a peripherally inserted central catheter (PICC) in hospitalized patients make this device very important for intravenous therapy. This study describes the use of PICCs at the Institute of Orthopedics and Traumatology at the Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo over the last 10 years. Methods This retrospective study analyzed 1,057 medical records and included 1,023 medical files with complete information on the punctured vein, diagnosis, duration of catheterization, complications, and catheter tip positioning. Results Seven hundred and twenty PICCs (70.4%) were considered successfully positioned, and mean duration of catheterization was 34.3 days. The basilic vein was used in 528 (51.6%) patients, while 157 (15.4%) catheters were removed due to complications. No cases of catheter-related thrombosis or infection were found. Eight hundred and sixty-six (84.6%) patients completed their treatment with PICC in place. Conclusion PICC is a safe intravenous device that can be successfully utilized for medium- and long-course intravenous therapy in hospitalized and discharged orthopedic patients. Level of Evidence IV; Case series.

RESUMO Objetivo: É difícil definir parâmetros para o tratamento e os fatores associados ao prognóstico de linfoma ósseo primário (LOP). Apresentamos a experiência de uma única instituição, com 42 casos de LOP durante 16 anos (2000-2016). Métodos: Cinquenta e cinco pacientes avaliados retrospectivamente e quarenta e dois incluídos (76,3%). Resultados: A mediana da idade foi 51,5 anos e a mediana do seguimento foi 102,7 meses. Um paciente era portador do vírus da imunodeficiência humana. Dor no membro foi o sintoma mais prevalente. O tempo médio entre os sintomas e o diagnóstico foi de 5,4 meses. O sítio anatômico mais afetado foram as vértebras (n = 16, 33,3%). Em relação à International Prognostic Index Score (IPI), 64,3% dos pacientes tinham baixo grau e 25,7% tinham baixo-intermediário. O diagnóstico histológico mais comum foi linfoma difuso de grandes células B (LDGCB), com 85,7% dos casos. A imunofenotipagem foi positiva para CD20 em 95,3%. Onze pacientes tinham fratura patológica. Todos receberam quimioterapia, sendo que 30% dos regimes incluíam rituximabe. A radioterapia foi utilizada em 38% dos pacientes. A porcentagem total de sobrevida foi de 50% e o tempo médio de sobrevida foi de 80 meses. A idade e o regime de quimioterapia juntos influenciaram diretamente a sobrevida dos pacientes. Os pacientes jovens, assim como os que receberam RCHOP, tiveram prognóstico de sobrevida melhor. Conclusão: A escolha do regime de quimioterapia associada à idade do paciente influenciou a sobrevida dos pacientes com LOP. Nível de Evidência IV; Série de casos.

ABSTRACT Objective: It is difficult to define parameters for management and factors associated with primary bone lymphoma (PBL). This article presents the experience in a single institution with 42 patients with PBL over a 16-year period (2000-2016). Methods: Fifty-five patients were retrospectively evaluated, and forty-two were included (76.3%). Results: Median age at diagnosis was 51.5 years, and median follow-up was 102.7 months. One patient had HIV. Pain in the affected site was the most prevalent symptom. The average time between symptom onset and diagnosis was 5.4 months. The vertebrae were most affected (n=16, 33.3%). According to the International Prognostic Index Score (IPI), 64.3% of the patients were classified as having low-grade lymphoma and 25.7% as low-intermediate. The most common histology was diffuse large B cell lymphoma (DLBCL) (85.7%). Immunophenotyping was CD20 positive in 93.5% of patients, and 11 patients had pathological fracture. All patients received chemotherapy and 30% of the regimens included rituximab. Thirty-eight percent of patients received radiation therapy. Overall survival was 50%, and survival median time was 80 months. Age and chemotherapy regimen influenced patient survival. Younger patients and patients who received RCHOP had better prognoses. Conclusions: The choice of chemotherapy regimen associated with age influenced survival for patients with PBL. Level of Evidence IV; Case series.

ABSTRACT Objective: To study the relationship between the serum levels of alkaline phosphatase (AP) and lactate dehydrogenase (LDH), and the percentage of tumor necrosis (TN) in patients with Ewing´s Sarcoma (ES) . Methods: This is a case series with retrospective evaluation of patients with diagnosis of ES divided into 2 groups: Group 1, patients whose serum levels of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) were obtained in the staging phase before preoperative chemotherapy (CT), and Group 2, patients whose values were measured after completion of the preoperative CT. The percentage of tumor necrosis (TN) of surgical specimens extracted in surgery was also evaluated . Results: Eighty four medical records from 1995 to 2015 were included. Both AP as LDH decreased in the patients studied, the pre CT value being higher than the post CT value. The average decrease of LHD was 272.95 U/L and AP was 10.17 U/L. The average tumor necrosis was 65.12 %. There was no statistical correlation between serums levels and the tumor necrosis percentage . Conclusion: The serum levels values of AP and LDH are not predictors for chemotherapy-induced necrosis in patients with ES. Level of Evidence IV, Case Series.

ABSTRACT Objective: To study the relationship between the pre and post chemotherapy (CT) serum levels of alkaline phosphatase (AP) and lactate dehydrogenase (LDH), and the percentage of tumor necrosis (TN) found in specimens after the pre surgical CT in patients with osteosarcoma. Methods: Series of cases with retrospective evaluation of patients diagnosed with osteosarcoma. Participants were divided into two groups according to serum values of both enzymes. The values of AP and LDH were obtained before and after preoperative CT. The percentage of tumor necrosis (TN) of surgical specimens of each patient was also included. Results: One hundred and thirty seven medical records were included from 1990 to 2013. Both the AP as LDH decreased in the patients studied, being the higher in pre CT than post CT. The average LHD decrease was 795.12U/L and AP decrease was 437.40 U/L. The average TN was 34.10 %. There was no statistically significant correlation between the serums values and the percentage of tumoral necrosis. Conclusion: The serum levels values of AP and LDH are not good predictors for the chemotherapy-induced necrosis in patients with osteosarcoma. Level of Evidence IV, Case Series.

ABSTRACT Objective: To obtain epidemiological data from the tumors of the patella diagnosed and treated at the Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Universidade de São Paulo (IOT-HC-FMUSP) between 1998 and 2015. Methods: Series of cases with retrospective evaluation of patients diagnosed with tumors located in the patella. The data was obtained from the records and patients' charts at the Department of Pathology of IOT-HC-FMUSP. Results: A total of 2220 medical records from patients with anatomopathological reports were included in the study. Only eight (0.3%) patients had patellar tumors. We found that six (75%) of these were benign, one (12.5%) was a pseudotumoral lesions and one (12.5%) was reported as malignant. Among benign tumors, the giant cell tumor (GCT) was the most frequently reported corresponding to 50% of the cases. Hemagioendothelioma was the only case of malignant tumor in this series. As for the pseudotumoral lesions, we found a brown tumor. Conclusion: From the data obtained retrospectively in a 17 year time frame, in a service that treats benign, malignant and pseudotumoral bone lesions, we conclude that our casuistry in patellar tumors is similar to that reported in scientific literature, where benign tumors are predominant in a 7:1 ratio over malignant tumors, being a rare location of appearance, with the GCT as the most common diagnosis . Level of Evidence IV, Case Series.