Tumor mesenquimático fosfatúrico de pelvis: abordaje multidisciplinario / Phosphaturic mesenchymal tumor of the pelvis: A multidisciplinary approach

El tumor mesenquimático fosfatúrico es una entidad clinicopatológica sumamente infrecuente. Además de provocar dolor óseo insidioso y polimialgias, se acompaña de alteraciones del metabolismo fosfocálcico de difícil manejo clínico. El abordaje multidisciplinario resulta la clave del éxito en esta enfermedad. Presentamos una paciente de 52 años de edad con antecedente de tumor mesenquimático fosfatúrico en la hemipelvis derecha con extensión a la cadera homolateral de 10 años de evolución. Clínicamente presentaba osteomalacia oncogénica (hipofosfatemia e hiperfosfaturia) que no se corregía, pese a un agente de última generación, el burosumab, un inhibidor del factor de crecimiento fibroblástico 23, que aumenta la reabsorción tubular renal de fosfatos. En un comité multidisciplinario, se decidió la resección con márgenes oncológicos y se logró una mejoría clínica franca. Comunicamos este caso, debido a que es un cuadro infrecuente. Nivel de Evidencia: IV

Phosphaturic mesenchymal tumor (PMT) is an infrequent clinicopathological entity. It presents insidious bone pain and polymyalgia, accompanied by alterations in calcium and phosphorus metabolism that are difficult to resolve clinically. A multidisciplinary approach is a key to success in this pathology. We present the case of a 52-year-old female patient with a 10-year history of PMT in the right hemipelvis with ipsilateral hip extension. From the clinical point of view, she presented oncogenic osteomalacia (hypophosphatemia and hyperphosphaturia) that did not correct despite being administered the latest generation medication, burosumab, an FGF-23 inhibitor that increases renal tubular phosphate reabsorption. Resection with oncological margins was decided by a multidisciplinary committee resolving her clinical condition. Due to the rarity of this pathology, we decided to report the case. Level of Evidence: IV

Tumour in a tumour: a well-differentiated spindle cell sarcoma within a forearm lipoma.

Lipomas are common, benign, soft tissue masses in adults. Sarcomatous change within a giant lipoma is a very rare event. We present a case of a woman presenting with a forearm lipoma that subsequently developed a central, well-differentiated, spindle-cell sarcoma within the lipoma. This case underlines the importance of identifying red flags for referral of soft tissue tumours.

Luxación de una prótesis abisagrada de rodilla: Reporte de un caso / Posterior dislocation of a hinged knee prosthesis. Case report

Las prótesis abisagradas de rodilla tienen índices de complicaciones que pueden llegar al 44% en 15 años. La luxación protésica secundaria a una ruptura del mecanismo abisagrado resulta ser la complicación alejada más frecuente luego del aflojamiento mecánico. Presentamos un caso de luxación protésica posterior, en un implante abisagrado rotatorio de tercera generación (Rotax, FII SA®, Saint Just Malmont, Francia), implantado originalmente en una paciente de 69 años, con artritis reumatoide y en terapia prolongada con metilprednisona y metotrexato a altas dosis. El tratamiento se realizó en ambas rodillas, en dos tiempos para corregir una deformidad en ráfaga altamente invalidante. Nuestra hipótesis postula que la luxación se debió a la ruptura del buje de polietileno del implante, este es el eslabón más débil del mecanismo abisagrado. Existen escasos reportes bibliográficos sobre esta particular complicación. Sin embargo, encontramos homogeneidad en las conclusiones, que consideran el ensamble entre el componente tibial y femoral, como el punto más frágil del sistema. Recomendamos, en estos complejos escenarios, efectuar la revisión protésica solo ante la presencia de episodios clínicos evidenciables, como luxaciones o inestabilidad persistente. Nivel de Evidencia: IV

Hinged knee prosthesis has a complication rate up to 44% at 15 years. Prosthetic dislocation secondary to a breakage of the hinged mechanism turns to be the second most frequent late complication after mechanical loosening. We present a patient with a posterior dislocation of a third generation rotating hinged total knee replacement (Rotax, FII SA®, Saint Just Malmont, France), implanted originally in a 69-year-old woman with rheumatoid arthritis and history of treatment with metilprednisone and methotrexate at high doses. The bilateral arthroplasty was performed in two times to correct a highly disabling deformity. We hypothesize the dislocation is due to the breakage of the polyethylene yoke of the prosthesis, being the weakest link of the hinged mechanism. There are rare bibliographic reports about this complication. However, we found similar conclusions, considering the engage of the tibial and femoral components as the weakest link of the system. We recommend in these complex scenarios to perform revision surgery only in cases with high repercussion in daily life presenting persistent instability or multiple dislocations. Level of Evidence: IV

Stage III Advanced Wrist Collapse Treatment Options: A Cadaveric Study.

Background 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, lunate-capitate arthrodesis, and triquetrum excision. Methods Four paired (n = 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 triquetrum-hamate 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.