Complementary Saphenous Nerve Block to Intra-Articular Analgesia Reduces Pain After Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

BACKGROUND: Numerous strategies exist for pain management after total knee arthroplasty (TKA), with a fast recovery and early ambulation required for full function. Currently, there is no universal standard of care to facilitate this management. We assessed pain management safety and efficacy after TKA, using intra-articular infiltration associated with peripheral saphenous nerve block (SNB) vs intra-articular infiltration alone. METHODS: We performed a controlled, double-blinded, and randomized trial to evaluate postoperative pain in TKA. One group was treated with intra-articular analgesia associated with SNB, whereas a second group received the same intra-articular cocktail, associated with placebo. Efficacy was evaluated according to average pain, pain-free time, and morphine rescue indices. Safety was assessed by intervention complications and surgery. RESULTS: About 70 patients were recruited. At time 0 (immediately postoperative), 51.43% of the intra-articular analgesia + placebo group presented pain <3, whereas in the intra-articular analgesia + SNB group, 8.82% (P = .001) presented with pain. This difference was maintained at 6, 12, and 24 hours, postoperatively. After 24 hours, the placebo group received an average 0.66 morphine rescues (standard deviation, 0.86), when compared with the SNB group that received 0.14 rescues (standard deviation, 0.43), (P = .002). We recorded a paresis of the external popliteal sciatic nerve, with spontaneous recovery without other complications. CONCLUSION: Complementary SNB to intra-articular analgesia was more effective in reducing average pain and the amount of pain-free time in the first 24 hours after TKA, with fewer requests for morphine rescue analgesia.

Unusual Listeria monocytogenes hematogenous infection in total knee replacement treated with one-stage revision surgery.

Septic arthritis due to Listeria monocytogenes (LM) is extremely rare and most infections due to this organism are seen in immunocompromised patients. We describe a patient without immunological compromise, with a late total knee arthroplasty infection caused by LM treated with one-stage revision surgery. She had an elevated erythrocyte sedimentation rate (79 mm/h) and C-reactive protein (13 mg/dL). Aspiration of the knee joint yielded purulent fluid; cultures showed LM. The patient was given 6 weeks of intravenous ampicillin, followed by trimethoprim/sulfamethoxazole, and finally amoxicillin orally for 7 months. Two years after revision surgery, radiographs showed no evidence of implant loosening. This is a single case and although one-stage approach seemed to have worked, it should not be recommended on the basis of a single report.

Cement augmentation of implants--no general cure in osteoporotic fracture treatment. A biomechanical study on non-displaced femoral neck fractures.

Femoral neck fractures in the elderly are a common problem in orthopedics. Augmentation of screw fixation with bone cement can provide better stability of implants and lower the risk of secondary displacement. This study aimed to investigate whether cement augmentation of three cannulated screws in non-displaced femoral neck fractures could increase implant fixation. A femoral neck fracture was simulated in six paired human cadaveric femora and stabilized with three 7.3 mm cannulated screws. Pairs were divided into two groups: conventional instrumentation versus additional cement augmentation of screw tips with 2 ml TraumacemV+ each. Biomechanical testing was performed by applying cyclic axial load until failure. Failure cycles, axial head displacement, screw angle changes, telescoping and screw cut-out were evaluated. Failure (15 mm actuator displacement) occurred in the augmented group at 12,500 cycles (± 2,480) compared to 15,625 cycles (± 4,215) in the non-augmented group (p = 0.041). When comparing 3 mm vertical displacement of the head no significant difference (p = 0.72) was detected between the survival curves of the two groups. At 8,500 load-cycles (early onset failure) the augmented group demonstrated a change in screw angle of 2.85° (± 0.84) compared to 1.15° (± 0.93) in the non-augmented group (p = 0.013). The results showed no biomechanical advantage with respect to secondary displacement following augmentation of three cannulated screws in a non-displaced femoral neck fracture. Consequently, the indication for cement augmentation to enhance implant anchorage in osteoporotic bone has to be considered carefully taking into account fracture type, implant selection and biomechanical surrounding.

Evaluación clínica y radiológica de la instrumentación y artrodesis corta por vía posterior en fracturas toracolumbares

Introducción: El tratamiento quirúrgico de las fracturas toracolumbares es controvertido. La vía de abordaje y la cantidad de niveles de instrumentación son motivo de debate. El objetivo de este estudio fue analizar los resultados radiológicos y clínicos de pacientes con fracturas toracolumbares por estallido y flexión/distracción. Materiales y Métodos: Estudio retrospectivo de una serie consecutiva de pacientes tratados quirúrgicamente entre 2004 y 2008, con seguimiento >12 meses. Se incluyeron pacientes con instrumentación y artrodesis corta de los niveles adyacentes a la lesión, abordados por vía posterior. Se tomaron en cuenta fracturas de tipo A3 y B de la clasificación AO. Se llevaron a cabo evaluaciones clínica, neurológica y radiológica. Resultados: Se registraron 25 pacientes, 3 se perdieron en el seguimiento y 22 fueron analizados. El promedio de edad fue de 37 años. La causa más frecuente fue caída de altura, seguida de accidente vehicular. El nivel más afectado fue L1. El promedio de cifosis preoperatoria fue de 14° y de 4º en el posoperatorio alejado. En la evaluación clínica, 10 pacientes tuvieron un excelente resultado; 10, bueno y 2, regular. No hubo compromiso neurológico en 21 pacientes. Conclusiones: La instrumentación corta proporciona muy buenos resultados en la mayoría de los pacientes tanto a nivel radiológico como funcional. La selección de los pacientes debe ser estricta, se debe excluir a aquellos con cifosis grave, conminución importante u otro factor que haga pensar en la necesidad de un abordaje anterior. En el seguimiento alejado, no se observa una pérdida significativa de la reducción en la cifosis.(AU)

Background: Surgical treatment of thoracolumbar fractures is controversial. The approach and number of levels of instrumentation are debated. The aim of this study is to assess the clinical and radiological outcomes of burst fractures. Methods: Retrospective study. Consecutive series of patients treated with short instrumentation and posterior fusion between 2004 and 2008, with a minimum follow-up of 12 months. Type A3 and B fractures of AO classification were included. Clinical, neurological and radiological outcomes were analyzed. Results: Twenty-five patients were included and 22 completed the follow-up. The average of age was 37 years. The most common cause was fall from high, followed by road accident and the most affected region was L1. The average of kyphosis was 14° before surgery and 4° in the remote follow-up. Clinical evaluation was excellent in 10 patients, good in 10 and regular in 2. Twenty-one patients had no neurological compromise. Conclusions: Short instrumentation and posterior arthrodesis offer very good clinical and functional result in most patients. Patient selection must be strict, excluding those with severe kyphosis, significant comminution or other factor that would suggest the need for an anterior approach. Long-term follow-up did not show significant loose of kyphosis.(AU)