Altered wrist biomechanics consequent to a scapholunate dissociation or a scaphoid nonunion accelerates the degeneration of the surrounding articular surfaces and often induces arthritic progression referred to as a scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC). 1,2Watson and Ballet described four stages of the arthritic progression of the affected articulations. 2 Stage III progression is determined by radiological evidence of degenerative changes to both the radioscaphoid and the lunate-capitate joint surfaces, and is generally associated with progressive pain and reduced wrist Keywords ► scaphoid nonunion advanced collapse ► arthritis ► advanced collapse ► biomechanics ► wrist AbstractBackground Scapholunate advanced collapse and scaphoid nonunion advanced collapse result in high morbidity and pose significant challenges for active patients. Multiple treatment options have been proposed to yield satisfactory results; however, restoration of physiological wrist motion remains an issue. Questions/Purposes The objective of this study was to compare wrist mobility after four different treatment methods for grade III wrist collapse: (1) no treatment, (2) scaphoidectomy and lunate-capitate arthrodesis, (3) scaphoidectomy, lunate-capitate arthrodesis, and triquetrum-hamate arthrodesis, and (4) scaphoidectomy, lunatecapitate arthrodesis, and triquetrum excision. Methods Four paired (n ¼ 8) fresh-frozen human cadaveric upper limbs were used in this controlled laboratory study. Computed tomography scans were collected at all testing states and measurements were made to evaluate midcarpal joint mobility and alignment. Results A significant decrease in wrist extension was observed for all treatments. Middle column and two-column arthrodesis demonstrated no significant differences for carpal alignment and mobility. No significant differences were observed for triquetrumhamate mobility or wrist extension between the partial and two-column arthrodesis. Triquetrum excision significantly improved ulnar deviation. Conclusion The most important finding of this study was that the one-column arthrodesis has comparable carpal alignment and range of motion to that of bi-column arthrodesis. Clinical Relevance The results of this study suggest that a stage III advanced wrist collapse can be treated by isolated lunate-capitate arthrodesis with scaphoidectomy. Fusion between the remaining carpal bones may not be necessary because the carpal alignment and range of motion of the remaining joints were not significantly different in the present study.

RESUMENIntroducción: Las fracturas periprotésicas femorales luego de un reemplazo total de cadera son cada vez más prevalentes. Cuando estas asientan sobre un tallo flojo (B2) o con déficit de capital óseo (B3), según la clasificación de Vancouver, el tratamiento es la revisión del tallo femoral. Materiales y métodos: Se analizó retrospectivamente a 22 pacientes, 9 fracturas tipo B2 y 13 tipo B3 de la clasificación de Vancouver. El promedio del seguimiento fue de 48 meses. Se utilizaron tallos largos cementados junto con aloinjerto óseo impactado, tablas corticales, tallos largos no cementados de fijación distal y endoprótesis no convencionales, según el caso. Resultados: Se observó la curación y la remodelación de la fractura en todos los pacientes. Las complicaciones fueron 2 (9%) luxaciones, 1 (4,5%) infección, 1 (4,5%) fractura de calcar, 1 (4,5%) aflojamiento de cotilo y 2 (9%) decesos. Conclusiones: Las fracturas posoperatorias periprotésicas de fémur tipo B2 y B3 requieren recambio del tallo femoral, si bien existe una tendencia actual a utilizar tallos no cementados, en esta serie, dada la superposición de tratamientos, según cada subtipo de fractura, no obtuvimos diferencias entre el uso de tallos cementados junto con injerto y tallos no cementados. En casos de grave déficit de capital óseo, las endoprótesis no convencionales ofrecen una opción terapéutica para pacientes con baja demanda funcional. La clasificación de Vancouver es un instrumento útil para evaluar y decidir el tratamiento.PALABRAS CLAVE: Fractura periprotésica de cadera. Tallo largo cementado. Tallo largo no cementado. Revisión de cadera. TREATMENT OF VANCOUVER B2 AND B3 PERIPROSTHETIC FRACTURES OF THE FEMURABSTRACT Background: Periprosthetic fractures of the femur are becoming more prevalent. When this fracture occurs in a loose stem (B2) or with bone loss (B3), the treatment is femoral stem revision. Methods: We analyzed retrospectively 22 patients, 9 with type B2 fractures and 13 with type B3 fractures of the Vancouver classification. Follow-up averaged 48 months. We used cemented long stems, with impacted bone allograft, strut allograft, uncemented long stems (with distal fixation) and unconventional endoprosthesis according to the case. Results: All fractures healed and remodeled. The complications were 2 (9%) dislocations, 1 (4.5%) infection, 1 (4.5%) calcar fracture, 1 (4.5%) loosening of cemented acetabular component and 2 (9%) deaths. Conclusions: The periprosthetic femoral fractures B2 and B3 require replacement of the femoral stem, while there is a trend to use uncemented stems; in this series due to the overlap of treatments according to each subtype of fracture, there were no differences between the use of cemented stems with allograft or uncemented stem. In cases of severe bone loss the unconventional endoprosthesis offer a treatment option for patients with low functional demand. The Vancouver classification is a useful tool to guide the surgeon on the treatment.

Re su menIn tro duc ción: El objetivo de este reporte fue caracterizar los factores predisponentes de la fractura periprotésica intraoperatoria de fémur durante una artroplastia primaria de cadera. Materiales y Métodos: Entre 1999 y 2010, se analizaron 1943 reemplazos de cadera, en 28 casos, se produjo una fractura de fémur durante una artroplastia total de cadera primaria, lo que arroja una incidencia del 1,4%. Se utilizó la clasificación de Vancouver y se estudiaron la presencia de factores predisponentes, el tratamiento realizado, la evolución clínica y radiográfica. Resultados: Del total de la muestra, 23 (82,1%) fracturas eran de tipo A y 5 (17,9%), de tipo B. El promedio obtenido del ángulo cervicodiafisario del fémur de 140° (rango 120°-160°). El 71,4% de la muestra eran mujeres. El 7,1% presentaba osteosíntesis previa. La incidencia de fracturas fue del 3,54% para los implantes no cementados (16/452) y del 0,8% para los tallos cementados (12/1491). Se realizó lazada de alambre en 18 pacientes (64,3%), malla metálica más lazada de alambre en un paciente (3,6%) y en 9 (32,1%) tratamiento conservador. En 27 (96,4%) casos, la evolución fue buena y el puntaje promedio posoperatorio del Harris Hip Score fue de 93 puntos (rango 89-95). Conclusiones: El sexo femenino, el aumento del ángu-lo cervicodiafisario, la presencia de caderas displásicas, implantes no cementados y zonas de debilidad luego de retirar una osteosíntesis son factores predisponentes para sufrir este tipo de complicación, por lo que es recomendable realizar una lazada de alambre profiláctica cuando se conjuguen varios de los factores de riesgo mencionados.Palabras clave: Fractura periprotésica. Lazada de alambre. Artroplastia de cadera. Factores predisponentes.Predisposing factors for intraoperative femur fracture in primary total hip arthroplasty Abstract Background: The objective of this study was to characterize the predisposing factors for intraoperative femur fracture during primary total hip arthroplasty. Methods: From 1999 to 2010, 28 fractures occurring during 1943 primary total hip arthroplasties were analyzed, an incidence of 1.4%. Vancouver classification was used. The presence of predisposing factors, their treatment and clinical and radiological outcomes were evaluated. Results: Twenty three (82.1%) fractures were type A and 5 (17.9%) were type B. The average of the cervical-shaft angle was 140° (120°-160°). 71.4% were women and 7.1% had previous osteosynthesis. The incidence was 3.54% (16/452) in cementless femoral stems and 0.8% in cemented femoral stems (12/1491). Intraoperative treatments were: cerclage wire in 18 cases (64.3%), metal mesh plus cerclage wire in one patient (3.6%) and conservative treatment in 9 patients. Twenty seven (96.4%) patients obtained good results and the average Harris Hip Score was 93 points (89-95). Conclusions: Female patients, high cervical-shaft angle, hip dysplasia, cementless femoral stems and femur weakness after removing the osteosynthesis, are predisposing factors for this type of complicatio...

Objectives:The prevalence of asymptomatic femoroacetabular impingement (FAI) is unknown in the general population. The purpose of this study is to determine the prevalence of cam-type deformities in asymptomatic persons.Methods:We evaluated 84 volunteers without symptoms of FAI, which underwent a lateral radiograph of both hips. To determine the presence of cam type deformities, α-angle measurement was used. An α-angle > 50 ° indicates the presence of cam type deformity.Results:The average age was 28.7 years, with 18 females and 66 males. Of the 84 volunteers, 16 (19%) had an α-angle> 50 °, while the remaining 68 patients had α-angle <50 °. We found the presence of a cam- type deformity in 22.7% of males and 5.5% of women.Conclusion:Our results are consistent with the literature reviewed, finding a prevalence of 13.9 to 24.7% in men and in women 4-5.5% according to different authors. The high frequency of cam-type deformities in asymptomatic patients suggests that a high α-angle itself not only ensures the presence of symptoms or progression to osteoarthritis. Therefore, we hold that this finding should be complemented by physical examination, clinical symptoms and other imaging signs when taking decisions regarding the therapeutic management.

266 ResumenObjetivo: Describir los resultados obtenidos con el enclavado endomedular acerrojado en pacientes con fractura del tercio distal de la tibia. Materiales y Métodos: Se incluyeron pacientes con fracturas desplazadas del tercio distal de la tibia, tratadas con clavo endomedular. La muestra incluyó 35 pacientes. El tiempo de seguimiento posoperatorio fue de 29.2 meses. Se evaluaron el tiempo de consolidación, la consolidación viciosa y las complicaciones. Los resultados funcionales se determinaron con el puntaje de la AOFAS. Resultados: De los 35 pacientes con fractura del tercio distal de la tibia (24 de tipo A y 11 de tipo B de la clasificación AO), en todos, se logró la consolidación de la fractura. El tiempo promedio de consolidación fue de 17.2 semanas (rango 11-26). No se halló diferencia estadística (p = 0,201) en el tiempo de consolidación entre las fracturas asociadas con fracturas del peroné tratadas (13 semanas) o no tratadas (17 semanas). El puntaje de la AOFAS fue 86. Conclusión: Se plantea el enclavado endomedular con múltiples cerrojos distales como una buena alternativa de tratamiento para las fracturas de la tibia distal AO de tipo A o B, con bajo porcentaje de complicaciones y un alto índice de consolidación. Palabras clave: Fractura de tibia distal; enclavado endomedular. Nivel de Evidencia: IV Intramedullary nailing in distal third tibia fractures AbstractObjective: To describe the results obtained with intramedullary nailing in patients with distal third tibia fracture. Methods: Patients with displaced fractures of the distal tibia treated with intramedullary nailing were included. The sample comprised 35 patients. The follow-up was 29.2 months. Time of consolidation, malunion and complications were evaluated. Functional results were described according to the AOFAS score. Results: All patients with a distal third tibia fracture (24 type A and 11 type B) presented fracture healing. The average time to union was 17.2 weeks (range 11-26). There was no difference (p = 0.201) in the time to union between fractures associated with treated or untreated fibula fractures (13 and 17 weeks, respectively). The AOFAS score was 86 points.Enclavado endomedular en fracturas del tercio distal de la tibia