Obturator dislocation of total hip arthroplasty with disassembly of the prosthesis components and periprosthetic fracture in morbid obese patient / Luxación obturatriz de una prótesis total de cadera con desensamblaje de los componentes y fractura periprotésica en un paciente obeso

Abstract: Introduction: Anterior dislocation is a rare complication of total hip arthroplasty (THA). There exist only three cases in the literature. None of them report disassembly of the prosthesis components. We present a morbidly obese woman who suffered an irreducible obturator dislocation of an infected total hip arthroplasty (THA), due to uncontrolled adduction during an early debridement surgery. Following unsuccessful closed reduction attempts, a Vancouver B2 periprosthetic fracture and disassembly of the prosthetic components were observed. Two-stage revision THA was necessary to resolve the infection and restore hip functionality. In obturator dislocation, the femoral head prosthetic can be trapped in the obturator foramen, and this may disassemble the prosthesis components during reduction maneuvers; there's also risk of periprosthetic fracture. This mandate an open reduction of the joint. Patient obesity could be a determining factor for this rare type of hip arthroplasty dislocation. Obturator dislocation is an extremely rare complication of the total hip arthroplasty, whose reductions should be handled with caution given the risks of periprosthetic fractures. In most cases, an open reduction of the joint is required. Clinical importance: Our work is likely to be of great interest because it offers tips for the management of this rare complication based on our experience.

Resumen: Introducción: La luxación anterior es una complicación poco frecuente de la artroplastia total de cadera (ATC). Sólo existen tres casos en la literatura. Ninguno de ellos informa del desmontaje de los componentes de la prótesis. Presentamos el caso una mujer obesa que sufrió una luxación irreducible de una artroplastia total de cadera (THA), la cual estaba infectada, debido a la aducción no controlada durante una cirugía de desbridamiento temprano. Después de los intentos fallidos de reducción cerrada, se presentó una fractura periprotésica clasificada como Vancouver B2 y el desmontaje de los componentes protésicos. Ameritó cirugía de revisión en dos etapas, lo cual se realizó para resolver la infección y restaurar la funcionalidad de la cadera. En la luxación obturatriz, la cabeza femoral puede quedar atrapada en el agujero obturador y, como consecuencia, favorecer la disociación de los componentes protésicos al intentar la reducción, asimismo puede favorecer un brazo de palanca que produzca una fractura periprotésica. La obesidad puede ser un factor determinante para la producción de esta rara complicación. Por todo lo anterior, se recomienda considerar de entrada la reducción abierta. La luxación obturatriz es una complicación rara en la artroplastia total de cadera; su tratamiento puede ser difícil y asociarse a fracturas. La relevancia de este caso es que permite mostrar algunas estrategias de manejo para prevenir complicaciones catastróficas.

Fracturas periprotésicas de fémur en artroplastia total de rodilla: experiencia con técnica mínimamente invasiva / Peri-prosthetic femoral fractures in total knee arthroplasty: experience using minimally invasive plate osteosynthesis

ANTECEDENTES: La fractura periprótesica de fémur en artroplastia total de rodilla supone uno de los mayores retos quirúrgicos. La tasa de complicaciones generales supera el 30% tanto con tratamiento conservador como con el quirúrgico. Parece que la técnica de osteosíntesis con placas bloqueadas de manera mínimamente invasiva ofrece buenos resultados para el tratamiento de las fracturas en las que no existe movilización del componente femoral. MÉTODOS: Se estudian retrospectivamente, desde enero de 2005 hasta diciembre del 2011, 32 pacientes, evaluando el tiempo de consolidación, el rango de movilidad, la deambulación y el alineamiento final mediante la realización de telemetrías en carga. El seguimiento medio fue de 56,5 meses (25-144). RESULTADOS: Se siguieron 32 pacientes (31 mujeres; un hombre) de los cuales el rango medio de edad fue de 77 años (70-89). Tres pacientes fallecieron (9%) y 4 pacientes (12%) se perdieron en la evolución final. La tasa media de consolidación fue de 16,5 semanas (8-24); no se produjeron infecciones, presentaron 3 seudoartrosis y solo se produjo un alineamiento en excesivo valgo (15°). El balance articular fue similar al previo a la fractura. La deambulación final fue igual a la previa en 24 de los 25 casos. CONCLUSIONES: Es una técnica adecuada para conseguir la consolidación en este tipo de fracturas y restablecer tanto la movilidad previa como un alineamiento correcto de la extremidad.

BACKGROUND: Peri-prosthetic fracture of the distal femur above total knee arthroplasty presents a challenging surgical problem for orthopaedic surgeons, as complication rates for both surgical and non-surgical treatment have been reported to be as high as 30%. The minimally invasive plate osteosynthesis (MIPO) technique seems to have better results than other techniques in this type of fracture when there is no loosening of the femoral implant. METHODS: A total of 32 patients with this fracture were treated from January 2005 to December 2011. A retrospective review was conducted on the weeks of consolidation, range of motion, final alignment, and the ability to walk. The mean follow up was 56.5 months (25-144). RESULTS: A total of 32 (31 female, 1 male) patients, with a mean age 77 (70-89) years old were treated, of whom 3 (9%) died and 4 were lost to follow-up. The mean time of consolidation was 16.5 weeks (8-24). There were no infections, although there were 3 non-unions and 1 malalignment (15° of valgus). We were able to restore the range of motion in every patient as it was before the fracture, as well as the ability to walk outdoors in 24 patients. CONCLUSION: The MIPO technique is a great technique in order to achieve a good range of motion and alignment of these fractures.

Autosomal Dominant Type I Osteopetrosis Is Related with Iatrogenic Fractures in Arthroplasty

Autosomal dominant osteopetrosis (ADO) is a sclerotic bone disorder due to failure of osteoclasts. ADO poses difficulties during arthroplasty because of the increased chance for iatrogenic fractures due to sclerotic bone. ADO is divided into two types based on radiological findings, fracture risk, and osteoclast activity. These differences suggest less brittle bone in patients with ADO I compared to that of patients with ADO II, which suggests a smaller chance of preoperative fractures during cementless arthroplasty in ADO I compared with that in ADO II. A case of cementless total knee arthroplasty in a patient with ADO I is presented. Total hip arthroplasty was performed during follow-up, and known major problems related to ADO II were experienced. Therefore, the differences between ADO I and ADO II may not be clinically relevant for an iatrogenic fracture during arthroplasty in patients with ADO.

The Outcome and Complications of the Locked Plating Management for the Periprosthetic Distal Femur Fractures after a Total Knee Arthroplasty

BACKGROUND: The osteosynthesis of the periprosthetic fractures following a total knee arthroplasty (TKA) can be technically difficult with the relatively small satisfactory outcomes and the high complication rates. The purpose of the study is to analyze the mid-term radiological and functional outcomes following the locked plating of the distal femur periprosthetic fractures after a TKA. METHODS: Records of 20 patients with a periprosthetic distal femur fracture following TKA treated by the locked plate osteosynthesis were retrospectively evaluated. The union rate, complications and functional outcome measures were analyzed. RESULTS: Successful union was achieved in 18 of the 19 patients available for the follow-up. The mean follow-up was 39 +/- 10 months. Significant reductions (p < 0.05) in the range of motion and Western Ontario and McMaster Universities Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were evident in the follow-up. Secondary procedures were required in 5 patients to address the delay in union and the reduced knee range of motion. The osteosynthesis failed in 1 patient who underwent a revision TKA. CONCLUSIONS: The satisfactory union rates can be achieved with the locked plate osteosynthesis in the periprosthetic distal femur fractures after TKA. Prolonged rehabilitation coupled with the un-modifiable risk factors can decrease the activity and satisfaction levels, which can significantly alter the functional outcome.