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BRCA1/2 mutations in Latin America are scarcely documented and in serious need of knowledge about the spectrum of BRCA pathogenic variants, information which may alter clinical practice and subsequently improve patient outcome. In addition, the search for data on testing policies in different regions constitutes a fundamental strength for the present study, which analyzes BRCA1/2 gene sequences and large rearrangements in 940 probands with familial and/or personal history of breast/ovary cancer (BOC). In non-mutated DNA samples, Multiplex Ligation-dependent Probe Amplification assays (MLPA) were used for the analysis of large rearrangements. Our studies detected 179 deleterious mutations out of 940 (19.04%) probands, including 5 large rearrangements and 22 novel mutations. The recurrent mutations accounted for 15.08% of the total and only 2.87% of the probands analyzed, very different from a Hispanic panel previously described. In conclusion: a) this first comprehensive description of the spectrum in BRCA1/2 sheds light on the low frequency of recurrent mutations; b) this information is key in clinical practice to select adequate sequencing studies in our population, subsequently improve patient outcome and prevent damage associated to false normal reports resulting from the use of invalid population panels; c) panels of mutations from other populations should be cautiously validated before imported, even those of apparently similar origin, a concept to be considered beyond significance in Argentina. Fil: Solano, Angela Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina Fil: Cardoso, Florencia Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Romano, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Perazzo, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Bas, Carlos. Hospital Aleman; Argentina Fil: Recondo, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Santillan, Francisco Bernardo. Sanatorio Mater Dei; Argentina Fil: Gonzalez, Eduardo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina Fil: Abalo, Eduardo. Instituto Universitario CEMIC; Argentina Fil: Viniegra, Maria. Centro de Estudios de Estado y Sociedad; Argentina Fil: Davalos Michel, José. Universidad de Buenos Aires. Facultad de Medicina; Argentina Fil: Nuñez, Lina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Nobilia, Cristina Maria. Instituto de Oncología “Angel H. Roffo”. Universidad de Buenos Aires; Argentina Fil: Mc Lean, Ignacio. Hospital Universitario Austral; Argentina Fil: Diaz Canton, Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Chacon, Reinaldo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina Fil: Cortese, Gustavo. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina Fil: Beccar Varela, Eduardo. Hospital Universitario Austral; Argentina Fil: Greco, Martin Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET.; Argentina Fil: Barrientos, Maria Laura. Hospital Regional Victor M. Sanguinetti; Argentina Fil: Avila, Silvia Adela. Hospital Provincial de Neuquén; Argentina Fil: Vuotto, Hector Daniel. Sanatorio Mater Dei; Argentina Fil: Lorusso, Antonio. Liga Argentina de Lucha contra el Cancer; Argentina Fil: Podesta, Ernesto Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentina Fil: Mando, Oscar Gaspar. Centro de Educación Médica e Investigaciones Clínicas “Norberto Quirno”; Argentina

Introduction: Femoral graft fixation in the anterior cruciate ligament reconstruction is a key factor to the success of this procedure. The aim of this study is to compare two different femoral fixation methods in the anterior cruciate ligament reconstruction. Material and methods: 147 patients with an anterior cruciate ligament reconstruction with quadruple hamstring grafts were retrospectively analyzed. 16 were female and 131 male, average age was 26.3 years. The minimum follow-up was 12 months with an average of 62 months. Patients were divided into two groups according to the femoral graft fixation: in ninety eight patients a transverse fixation was used, and in forty nine a cortical fixation with femoral button. Tibial interference screws were used for both groups. Clinical evaluation with Lysholm Score and IKDC was performed. Results: Lysholm score results show no significant differences between the groups, being 94.24 points in the group with the transversal fixation system and 93.26 in the other group. According to the IKDC, 141 patients presented a normal or close to normal knee and 1 patient presented an abnormal knee. Five patients presented graft rupture (3.4%), 3 from the cortical fixation with button group (6.12%) and two with transverse fixation (2.04%). Conclusion: In this study, cortical button femoral fixation for autogenous hamstring ACL reconstruction had no significant difference in terms of clinical outcomes compared with suspensory transfemoral fixation.

BACKGROUND: In the management of a resected distal femoral or proximal tibial condyle as the result of tumor or trauma, a unicondylar osteoarticular allograft is currently the only reconstructive option that avoids the sacrifice of the unaffected condyle. The purposes of this study were to perform a survival analysis of unicondylar osteoarticular allografts of the knee and to evaluate the complications. METHODS: We retrospectively reviewed the results of forty large unicondylar osteoarticular allograft procedures in thirty-eight patients who were followed for a mean of eleven years. Twenty-nine allografts were femoral transplants and included eleven medial and eighteen lateral femoral condyles. Eleven allografts were tibial transplants, including four medial and seven lateral tibial condyles. The procedure was performed after a tumor resection in thirty-six patients and to replace condylar loss after a severe open fracture in the remaining two patients. Complications were analyzed, and allograft survival from the date of implantation to the date of revision or the time of the latest follow-up was determined. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up. RESULTS: One patient died of tumor-related causes without allograft failure before the two-year follow-up evaluation. The global rate of allograft survival at both five and ten years was 85%, with a mean follow-up of 148 months. In six patients, the allografts were removed at an average of twenty-six months (range, six to forty-eight months) and these were considered failures. All six patients underwent a second allograft procedure including two new unicondylar and four bicondylar reconstructions. The mean radiographic score for the thirty-three surviving allografts evaluated was 89%, with an average functional score of 27 of a possible 30 points. CONCLUSIONS: Unicondylar osteoarticular allografts of the knee appear to be a reliable alternative for patients in whom reconstruction of massive osteoarticular bone loss is limited to one condyle of the femur or tibia. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence. ORIGINAL ABSTRACT CITATION: “Unicondylar Osteoarticular Allografts of the Knee” (2007;89:2137-42).

This article describes a technique for reconstruction after intralesional curettage of a distal femoral giant-cell tumor, combining a morselized bone allograft to fill the cavity and a structural cortical allograft to reconstruct the cortical window and buttress the affected bone segment.

BACKGROUND: In the management of a resected distal femoral or proximal tibial condyle as the result of tumor or trauma, a unicondylar osteoarticular allograft is currently the only reconstructive option that avoids the sacrifice of the unaffected condyle. The purposes of this study were to perform a survival analysis of unicondylar osteoarticular allografts of the knee and to evaluate the complications. METHODS: We retrospectively reviewed the results of forty large unicondylar osteoarticular allograft procedures in thirty-eight patients who were followed for a mean of eleven years. Twenty-nine allografts were femoral transplants and included eleven medial and eighteen lateral femoral condyles. Eleven allografts were tibial transplants, including four medial and seven lateral tibial condyles. The procedure was performed after a tumor resection in thirty-six patients and to replace condylar loss after a severe open fracture in the remaining two patients. Complications were analyzed, and allograft survival from the date of implantation to the date of revision or the time of the latest follow-up was determined. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up. RESULTS: One patient died of tumor-related causes without allograft failure before the two-year follow-up evaluation. The global rate of allograft survival at both five and ten years was 85%, with a mean follow-up of 148 months. In six patients, the allografts were removed at an average of twenty-six months (range, six to forty-eight months) and these were considered failures. All six patients underwent a second allograft procedure including two new unicondylar and four bicondylar reconstructions. The mean radiographic score for the thirty-three surviving allografts evaluated was 89%, with an average functional score of 27 of a possible 30 points. CONCLUSIONS: Unicondylar osteoarticular allografts of the knee appear to be a reliable alternative for patients in whom reconstruction of massive osteoarticular bone loss is limited to one condyle of the femur or tibia. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence. ORIGINAL ABSTRACT CITATION: “Unicondylar Osteoarticular Allografts of the Knee” (2007;89:2137-42).

Objectives The prognosis of breast cancer patients depends on primary tumor resection and axillary lymph nodes examination. The purpose of this study was to analyze by molecular biology techniques the presence of mammaglobin A and B messenger RNA in breast sentinel lymph node (SLN) by reverse-transcription polymerase chain reaction (RT-PCR). Methods Sentinel lymph nodes from 50 patients with a diagnosis of breast cancer were prospectively studied between June 2004 and August 2006. Lymph nodes were all examined every 2 mm by intraoperative cytology. Hematoxylin-eosin (HE), immunohistochemistry (IHC) with cytokeratin (clone AE1-AE3, DAKO, dilution 1:100), and molecular biology techniques were used in all cases. Results Deferred study with routine techniques showed subcapsular metastasis in 3/50 cases. Out of 50 cases, 5 were detected with IHC, and 2 of them were negative for HE. Multiplex RT-PCR allowed the detection of 18/50 positive SLN, which included the 5 above-mentioned cases. The other SLN studied (32/50) showed no metastases with the methods herein implemented. Conclusions The epidemiologic impact of incomplete SLN study has been observed, as the HE technique fails to identify all SLN with micrometastases. In our opinion, SLN should be studied with IHC and molecular biology techniques. The multiplex RT-PCR technique for A and B mammaglobin proves to be specific and sensitive. This study will serve to formulate hypotheses. Further research, including a larger population and a longer-term follow-up period, will be required to confirm these hypotheses. Should our findings be confirmed in the future, molecular biology determinations could modify patients' staging and treatment.

The surgical risk and complication rates for an open excision of a benign osteochondroma have been reported as high as 13%. The advent of minimally invasive techniques allows a surgical resection with a smaller incision and a potential for less postoperative morbidity. We presumed endoscopic resection of symptomatic osteochondroma of the distal femur would decrease postoperative morbidity of open surgery and improve functional outcome. We performed endoscopic resection of a symptomatic osteochondroma in seven patients among 24 who had surgical excision. Preoperative studies include radiographs and computed tomography scans. At a mean followup of 33 months, patients were functionally evaluated according to the Lysholm score and the International Knee Documentation Committee scale. Four exostoses were located at the anterolateral femoral cortex, one at the trochlea, and two at the anteromedial cortex. Histologic diagnosis of an osteochondroma was confirmed in all cases. The average Lysholm score improved 22 points from a mean of 74 preoperatively to 96 postoperatively, and according to the International Knee Documentation Committee scale, all patients showed a normal knee. In 7 of 24 patients with a symptomatic osteochondroma of the distal femur close to the knee, we performed endoscopic resection with low morbidity and prompt functional recovery.

Reconstruction of extensor mechanism after proximal tibia tumor resection is a major concern, especially in young and physically active patients. We evaluated patellar tendon host- donor reattachments in 42 consecutive proximal tibia allo- graft reconstructions after bone tumor resection to determine if patellar tendon length and integrity was maintained, and if active knee extension and adequate function was achieved. Patellar tendon length was radiographically measured in all patients by the Insall-Salvati index while magnetic resonance was available in 19 patients to evaluate imaging integrity. Eight patients were not available for functional assessment, leaving 34 patients for clinical evaluation with the Musculoskeletal Tumor Society scoring system. According to the Insall-Salvati index evaluation, the reconstructed patellar tendon remained stable with no elongation between preoperative and postoperative measurements (1.15 versus 1.13). Postoperative magnetic resonance images showed a continuous patellar host-donor tendon in all. Active knee extension was restored in all functionally evaluated patients with an average functional score of 26.6 points. Twenty-four patients had no extensor lag, while ten had an average residual extensor lag of 6.5°. Our findings suggest patellar tendon reconstruction with allogeneic tissue from the proximal tibia allograft sutured to the recipient's remnant patellar tendon can restore and stabilize active knee extension. Level of Evidence: Therapeutic study, level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Intercalary femur and tibia segmental allografts were implanted in 59 consecutive patients after segmental resection-52 for malignant and seven for benign aggressive bone tumors. The patients were followed up for an average of 5 years. Allograft survival was determined with the Kaplan-Meier method. Infection, fracture, and nonunion rates were determined. The overall 5-year survivorship for the 59 intercalary allografts was 79%, and we found no significant differences between allograft survival in patients receiving or not receiving adjuvant chemotherapy. Infection and fracture rates were 5% and 7% respectively. From 118 host-donor junctions, 11 did not initially heal (9%). The nonunion rate (10 of 69 osteotomies) for diaphyseal junctions was higher than the rate (one of 49 osteotomies) for metaphyseal junctions. Although some patients required reoperations because of allograft complications, it seems that the use of intercalary allograft clearly has a place in the reconstruction of a segmental defect created by the resection of a tumor in the diaphyseal and /or metaphyseal portion of the femur or tibia.