Browsing by Author "Calvo R., Rafael"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
Item Aloinjertos óseos y la función del banco de huesos(2011) Calvo R., Rafael; Figueroa, David; Díaz Ledezma, Claudio; Vaisman, Alex; Figueroa, FranciscoThe use of bone grafts is a common practice in musculoskeletal surgery to provide mechanical stability where there is a defect and it allows skeletal reconstruction. Classically auto and allografts have been used. The latter are the choice in large, complex defects. Allografts can be transplanted despite cell death, have osteoconduction and osteoinduction capacity, low antigenicity and biomechanical properties similar to the original bone. They can be obtained from living and death donors. They are stored by cryopreservation and lyophilization in entities called bone banks. This is a reviw about bone allografts and the organization and function of the bone banks.Item Biomechanical and geometric characterization of peroneus longus allografts with respect to age(2019) Wong, Andrew; Schaffler, Benjamin; Nixon, Ryan; Carrero, Leanza; Neufeld, Eric; Grande, Daniel; Calvo R., Rafael; Calvo M., RafaelBackground: Anterior cruciate ligament injuries are among the most common injuries in high impact sports, and reconstruction is the standard surgical procedure for these ruptures. Reconstructions are often performed using allografts rather than autografts on a case-by-case basis. Controversy exists as to whether or not age of donor tissue plays a factor in the mechanical properties of allografts. Methods: 38 peroneus longus (PL) tendons were prepared using the two-strand graft technique and then subjected to a cyclic loading test regimen of 1000 cycles to determine material properties. Specimens were grouped based on age to ascertain whether donor age affects the material properties of PL tendons. Findings: Secant modulus of the first cycle was determined to be 150.43 (SD 40.24) MPa. The average magnitude of the dynamic modulus was determined to be 82.81 (SD 24.65) MPa. Specimens were grouped into three distinct groups for analysis (x < 40 yo, 40 yo ≤ x < 60 yo, 60 yo < x). Interpretation: The need for using intrinsic material properties is highlighted. There is no significant difference in any intrinsic material property with respect to age or the fatigue of the tendon as the cycle count increases. Conversely, the measured stiffness of a tendon decreased as function of age with a large effect size. Based on analysis of graft geometries, it was determined that PL tendons become significantly more slender with increased age which result in the observed decrease in stiffness.Item Osteochondral autografts in full thickness patella cartilage lesions(2011) Figueroa, David; Melean, Patricio; Calvo R., Rafael; Gili, Federico; Zilleruelo, Nicolás; Vaisman, AlexThe purpose of this study was to evaluate clinical, functional and imaging results of full thickness patella cartilage lesions treated with osteochondral autografts (OCA). We studied a consecutive case series of 10 patients. At follow-up, Lysholm and International Knee Documentation Committee (IKDC) scores were obtained. Magnetic resonance imaging (MRI) evaluation was performed at an average of 8 months post-op. The average cartilage lesion area was 1.2 cm(2). An average of 1.9 grafts was used per patient. The average Lysholm scores were: pre-op 73.8 +/- 8.36; post-op 95 +/- 4.47 points (p < 0.05). The average IKDC post-op score was 95 +/- 1.74 points. No postoperative complications were registered. In the MRI analysis we found that in all cases. OCA presented flush characteristics when compared with adjacent cartilage. The majority of cases presented no fissures in the graft-receptor interface (60%). In 80% we observed mild bone marrow edema around the graft. According to the International Cartilage Research Society (ICRS) cartilage lesions classification, all grafts were considered 1A; in the periphery cartilage was classified as 1A in 60%. We conclude that patellar OCA is a good alternative for the treatment of full thickness patellar cartilage lesions, offering good clinical, functional and imaging results at midterm follow-up. (C) 2010 Elsevier B.V. All rights reserved.Item Platelet-Rich Plasma Use in Anterior Cruciate Ligament Surgery: Systematic Review of the Literature(The Arthroscopy Association of North America, 2015) Figueroa, David; Figueroa, Francisco; Calvo R., Rafael; Vaisman, Alex; Ahumada, Ximena; Arellano, SergioPurpose To systematically review the current literature for evidence that would substantiate the use of platelet-rich plasma (PRP) in the treatment of anterior cruciate ligament (ACL) ruptures. Methods We performed a systematic search in PubMed and Embase of studies written in the English and Spanish languages that compared the use of PRP with a control group in patients with ACL injuries assessing graft-to-bone healing, graft maturation, and/or clinical outcomes and were randomized controlled trials or prospective cohort studies. Results Eleven studies fulfilled the inclusion criteria, comprising 516 patients (266 ACL reconstructions using PRP and 250 ACL reconstructions without PRP). Six studies reported a statistically significant difference (4 studies) or tendency toward faster graft maturation in the platelet group (2 studies). One study found no differences. Regarding tunnel healing/widening, 1 study showed faster healing in the PRP group and 5 studies showed no differences between the 2 groups. Considering clinical outcomes, 1 study showed better clinical outcomes with PRP use and 5 studies showed no benefits with the use of PRP. Conclusions Concerning ACL graft maturation, there is promising evidence that the addition of PRP could be a synergic factor in acquiring maturity more quickly than grafts with no PRP, with the clinical implication of this remaining unclear. Regarding tunnel healing, it appears that there is not an improvement with the addition of PRP. There is no proof that clinical outcomes of ACL surgery are enhanced by the use of PRP.Item Prediction of semitendinosus-gracilis graft diameter in children and adolescents using anthropometric measures.(Springer International Publishing AG, 2016) Calvo R., Rafael; Espinosa, Maximiliano; Figueroa, David; Calvo M., RafaelPURPOSE: The aim of this study was to evaluate whether the anthropometric and demographic measures of patients under 18 years can be used to predict the diameter of STG autograft in ACL reconstruction surgery. METHODS: Retrospective series of 169 patients under 18 years (112 men, 57 women, average age 15.8 years) underwent ACL reconstruction surgery with STG autograft. We recorded anthropometric measures (weight, height and BMI), demographics (age and gender) and autograft diameter used. Correlation coefficients, linear regression and unpaired t test were used to determine the relationship between anthropometric/demographic variables and the diameter of the graft. p values <0.05 were considered statistically significant. RESULTS: Correlation analysis showed a significant positive relation between height and graft diameter (r = 0.483, p < 0.0001) as well as between weight and graft diameter (r = 0.248, p = 0.001). However, age and BMI did not correlate with graft thickness (r = 0.098 and p = 0.203, r = 0.009 and p = 0.905, respectively). The mean graft diameter in men was 8.2 (range 6-10) and 7.5 in women (range 6-9), a difference that was statistically significant (p < 0.001). CONCLUSIONS: Prediction of the STG graft diameter according to the height of the patient is an easy and reliable method in children and adolescents. These data may provide relevant preoperative information about the need of an alternative graft source and can be useful when counselling patients.Item Uso del plasma rico en plaquetas en cirugía ligamentosa de rodilla(2013) Figueroa P., David; Figueroa, Francisco; Ahumada P., Ximena; Calvo R., Rafael; Vaisman B., AlexPlatelet Rich Plasma (PRP) is used in musculoskeletal lesion surgery, including muscle, bone, tendons and ligaments. PRP might accelerate the healing process and the integration of the graft, allowing an earlier return to sports activities of patients. PRP is obtained from autologous blood, which is centrifuged, obtaining platelet and supposedly growth factor concentrations three to five times higher than those of regular blood. The clinical results of studies performed in Chile and elsewhere on PRP use in knee anterior cruciate ligament (ACL) reconstruction have been variable. Therefore, there is not enough evidence to support or deny the usefulness of PRP in ACL reconstructions.