[Bone defects in revision knee arthroplasty: filling with bone allograft plus platelet-derived growth factors]. / Defectos óseos en artroplastia de revisión de rodilla tratados con aloinjerto óseo y plasma rico en plaquetas.

BACKGROUND: One of the most challenging aspects of a revision knee arthroplasty is the management of bone loss. The OBJECTIVE of the study is to show the capability to augment bone mineral density in areas with bone loss with platelet-derived growth factors. METHODS: Randomized, prospective, blinded study in patients who underwent a total knee replacement revision with tibial-damaged metaphyseal bone were randomly allocated to have a revision total knee arthroplasty and to fill the bone defects with lyophilized bone allograft mixed with platelet growth factors (experimental group, n= 9) or with lyophilized bone allograft alone (control group, n= 7). To evaluate bone mineral density between groups, dual-energy X-ray absorptiometry (DEXA) was performed preoperatively, at 1 month, 6 months and 1 year after surgery. RESULTS: The study was comprised of a total of 16 patients. We found no significant differences observed during the follow-up between groups in mineral bone density. CONCLUSIONS: Use of platelet-derived growth factors does not improve bone mineral density in patients with revision knee arthroplasty.

ANTECEDENTES: uno de los aspectos más desafiantes de la artroplastia de revisión de rodilla es el manejo de la pérdida ósea. OBJETIVO: demostrar la capacidad de incrementar la densidad mineral ósea en áreas con pérdida ósea, mediante el uso de plasma rico en plaquetas. MATERIAL Y MÉTODOS: estudio prospectivo, aleatorizado, cegado; efectuado con pacientes a quienes se realizó artroplastia de revisión de rodilla con pérdida ósea metafisiaria de tibia. Los pacientes se asignaron al azar a dos grupos para rellenar los defectos con aloinjerto óseo liofilizado con plasma rico en plaquetas (grupo experimental, n= 9), y otro grupo que sólo recibió el injerto óseo liofilizado (grupo control, n= 7). En ambos grupos la evaluación de la densidad mineral ósea se hizo con absorciometría de rayos X de energía dual (DXA) antes de la operación, al mes, seis meses, y un año después de la cirugía. RESULTADOS: se estudiaron 16 pacientes sin diferencias significativas entre ambos grupos en la densidad mineral ósea durante el periodo de seguimiento. CONCLUSIONES: el plasma rico en plaquetas no demostró incrementar la densidad mineral ósea en pacientes con defectos óseos por artroplastia de revisión de rodilla.

Metabolic bone disease and bone mineral density in very preterm infants.

OBJECTIVES: To evaluate bone mineral density (BMD) in preterm neonates at discharge and identify the optimum cutoff values for serum alkaline phosphatase (ALP) and phosphorus (P) concentrations to diagnose the severity of metabolic bone disease of prematurity. STUDY DESIGN: A total of 336 preterm neonates (≤ 31 weeks' gestation and birth weight ≤ 1500 g) were prospectively evaluated for BMD before discharge using dual-energy X-ray absorptiometry. RESULTS: BMD reference values (at ALP ≤ 500 IU/L) were measured in 279 patients. BMD was classified as poor (<10th percentile) at <0.068 g/cm(2), fair (10th-25th percentile) at 0.068-0.081 g/cm(2), good (25th-75th percentile) at 0.081-0.112 g/cm(2), and very good (>75th percentile) at >0.112 g/cm(2). Increased BMD was associated with a higher birth weight, short duration of parenteral nutrition, and the absence of small for gestational age status, patent ductus arteriosus, intraventricular hemorrhage, and other clinical variables. Metabolic bone disease of prematurity was absent (ALP ≤ 500 IU/L) in 279 cases (83.0%), mild (ALP >500 IU/L and P ≥ 4.5 mg/dL) in 46 cases (13.7%), and severe (ALP >500 IU/L and P <4.5 mg/dL) in 11 cases (3.3%). CONCLUSIONS: A BMD >0.068 g/cm(2) at discharge indicated a 90.3% probability of not developing metabolic bone disease of prematurity. The factors independently associated with increased BMD included higher birth weight, short duration of parenteral nutrition, absence of intraventricular hemorrhage, exclusive feeding of fortified breast milk, and older age at discharge.

Multicenter validation of two nomograms to predict non-sentinel node involvement in breast cancer.

INTRODUCTION: Nomograms are used to predict the involvement of non-sentinel nodes (nSN) in breast cancer. This study attempts to externally validate two of the more commonly used nomograms (MSKCC and Stanford University). MATERIALS AND METHODS: Five hundred and one cases of positive SNB with posterior axillary lymphadenectomy from 11 Spanish hospitals with widespread experience of the technique were studied. In all cases, an estimate of the probability of nSN involvement was made using the MSKCC and the Stanford University nomograms. Discrimination was assessed by calculating the area under the receiver operating characteristic curve. To assess the calibration of the nomogram, observed probability was plotted against the nomogram-calculated predicted probability. RESULTS: The overall predictive accuracy of the MSKCC nomogram was 0.684 (95 % confidence interval, 0.635-0.732), while in the case of that from Stanford the predictive accuracy was 0.658 (95 % confidence interval 0.607-0.709). The mean predicted probability of nSN metastases in each group of patients was correlated with the observed probability with an acceptable concordance (r = 0.820; p < 0.004 in MSKCC nomogram and r = 0.888; p < 0.001 in Stanford nomogram). CONCLUSION: These nomograms can be useful tools in the evaluation of patients with breast cancer and positive sentinel nodes but other factors, including a comprehensive clinical assessment, must be used to decide the most appropriate surgical approach for an individual patient, especially with regard to avoiding unnecessary lymphadenectomy.

Loco-regional control after postoperative radiotherapy for patients with regional nodal metastases from melanoma.

INTRODUCTION: The role of adjuvant radiation therapy (RT) following nodal surgery in malignant melanoma remains controversial. There are no published randomised trials comparing surgery alone to surgery with postoperative RT. AIM AND METHODS: The purpose of the present retrospective study was to review the results of loco-regional control after postoperative RT in patients with nodal metastases of melanoma. Seventy-seven patients with high-risk disease (lymph nodes > or =3 cm, more than three lymph nodes involved, extracapsular extension and recurrent disease) were treated with adjuvant RT. Hypofractionation was used in 65 patients and conventional fractionation in 12 patients. RESULTS: Seventy-seven patients with nodal metastases from melanoma were managed with lymphadenectomy and radiation, with or without systemic therapy. The median age was 56 years old (range: 21-83). There were 47 males (61%) and 30 females (39%). Loco-regional control was observed in 95% of patients (73/77). The actuarial 5-year in-field loco-regional control rate was 90% (mean: 105 months; CI95%: 96-115 months). Median metastasis disease- free survival (MDFS) was 16 months (CI95%: 13-18 months). Median survival time (MST) for the entire group was 26 months (CI95%: 18-34 months). MST according to the localisation of node metastases (groin, axilla and cervical) was also analysed, without statistically significant differences (p=0.08). Concerning the number of risk factors score, analysis of survival did not show statistically significant differences (p=0.055). CONCLUSIONS: Despite the high incidence of distant metastases, loco-regional control remains an important goal in the management of melanoma. Surgery and adjuvant RT provides excellent loco-regional control, although distant metastases remain the major cause of mortality.