Tibial Tuberosity Rotation in Patients With Patellar Instability Versus Age- and Sex-Matched Controls.

Background: Several methods have been described to measure external rotation of the tibial tuberosity; all use femoral landmarks. Purpose: To develop reproducible tibial-based methods to measure external rotation of the tibial tuberosity in patients with patellar instability. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Included were magnetic resonance images of 61 patients with patellar instability and 61 age- and sex-matched healthy controls. Three novel methods using tibial landmarks to measure the rotation of the tibial tuberosity (plateau axis-tuberosity axis [PA-TA] angle, tibial geometric center-tuberosity axis [GC-TA] angle, and plateau axis-midtuberosity point [PA-MT] angle) as well as a femoral-based rotational measurement (surgical transepicondylar axis-tuberosity axis [sTEA-TA] angle) and the tibial tuberosity-trochlear groove (TT-TG) distance were measured and compared in instability patients and controls using unpaired t tests, and the cutoff values for predicting instability were calculated using receiver operating characteristic curves. The correlations between the angle measurements and the TT-TG distance were analyzed. Results: Instability patients had significantly higher external rotation of the tibial tuberosity compared with controls with regard to the PA-TA angle (18.2° ± 9.6° versus 13.1° ± 6.8°; P = .001), GC-TA angle (8.4° ± 4.5° versus 11.5° ± 3.9°; P = .0001) and sTEA-TA angle (122° ± 8.5° versus 113.6° ± 6.3°; P = .0001). The mean TT-TG distance was also significantly higher in the instability group (18.2 ± 5.4 versus 11.5 ± 2.7 mm; P = .001). The cutoff values were 17.5° (area under the receiver operating characteristic curve [AUC] = 0.66) for PA-TA angle, 8.5° (AUC = 0.705) for GC-TA angle, 118.8° (AUC = 0.79) for sTEA-TA angle, and 15.2 mm for TT-TG distance (AUC = 0.863). PA-TA angle was significantly correlated with all other measurements (r = 0.35-0.71; P ≤ .006 for all), whereas sTEA-TA angle had the strongest correlation with TT-TG distance (r = 0.78; P = .001). Conclusion: The tibial tuberosity was externally rotated in patellar instability patients compared with age- and sex-matched controls, and this intrinsic malalignment of the proximal tibia was demonstrated in the tibial-based measurements.

Topical co-delivery of platelet rich fibrin and tranexamic acid does not decrease blood loss in primary total knee arthroplasty compared to the standard of care: a prospective, randomized, controlled trial.

PURPOSE: The purpose of this study was to evaluate the efficacy of intra-operative co-administration of tranexamic acid (TA) and platelet rich fibrin (PRF) using a proprietary co-delivery system on the amount of blood loss, early functional outcomes and wound complications after primary total knee arthroplasty (TKA). The intervention was compared to the standard of care (combined intravenous & topical TA) in a prospective, randomized, blinded setting. METHODS: 80 patients undergoing primary cemented TKA without tourniquet were prospectively randomized into control (combined intravenous and topical TA) and PRF (intra-venous TA and co-delivery of topical PRF and TA) groups after informed consent. Total blood loss, drainage blood loss, knee range of motion, VAS pain scores, length of stay and wound complications were analysed. Data collection was performed in a double blind manner on days 1, 3 and 21. RESULTS: There was no statistically significant difference in drainage blood loss (550 ml vs. 525 ml, p = 0.643), calculated total blood loss on day 1 (401 ml vs. 407 ml, p = 0.722), day 3 (467 ml vs 471 ml, p = 0.471) and day 21 (265 ml vs. 219 ml, p = 0.082) between the PRF and control groups respectively. The PRF group had a small but statistically significant increase in median knee extension in the early post-operative period, however this difference evened out at 3 weeks. No significant difference could be demonstrated between the PRF and control groups in length of stay, VAS pain scores, narcotic usage, wound complications and knee flexion at all time points. CONCLUSIONS: The topical co-delivery of PRF and TA does not significantly decrease blood loss in primary TKA compared to the standard of care. Slightly better active knee extension in the first 3 postoperative days can be achieved, however this benefit is not clinically relevant. LEVEL OF EVIDENCE: I, Therapeutic study.

Effects of repeated sprint training on isocapnic buffering phase in volleyball players / Efeitos de treinos de sprint repetidos na faİxa de tamponamento İsocápnİco em jogadores de voleibol / Efectos del entrenamiento de sprint repetido en la fase de tamponamiento isocápnico en jugadores de voleibol

ABSTRACT Introduction: The region between the ventilatory threshold (VT) and respiratory compensation point (RCP) is defined as the isocapnic buffering (ICB) phase and represents a phase of compensation for exercise-induced metabolic acidosis. There is sparse literature examining the effects of physical training on ICB phase in athletes. Objectives: The purpose of this study was to examine the effects of a repeated sprint training program on the ICB phase of college volleyball players. Methods: Eighteen male volleyball players were randomly assigned to either an experimental group (n=9) or a control group (n=9) and followed a traditional volleyball training program three times per week for six weeks. The experimental group additionally performed a repeated sprint training protocol immediately before each volleyball training session. Before and after the 6-week training period, all participants performed an incremental treadmill test to determine VT, RCP, and maximal oxygen uptake (VO2max). The ICB phases were calculated as VO2 (ml/kg/min) and sprint speed (km/h). Results: The experimental group showed significant improvements in ICB phase, RCP, VO2max and maximal sprint speed after training (p<0.01). There were no significant changes in VT after training in the experimental group (p>0.05). None of these variables changed significantly in the control group (p>0.05). Conclusions: These findings indicate that repeated sprint training can enhance the ICB phase of volleyball players, which may be attributable to an improvement in buffering capacity leading to a shift in RCP towards higher intensities without any change in VT. The increase in the ICB phase may an important factor in terms of improvement in the high-intensity exercise tolerance of athletes. Level of Evidence II; Therapeutic studies - Investigating the results of treatment.

RESUMO Introdução: a região entre o limiar ventilatório (VT) e o ponto de compensação respiratório (RCP) é definido como faixa de temporamento isocápnico (ICB) e representa a fase de compensação para a acidose metabólica induzida por exercício. Há escassa literatura examinando os efeitos do treinamento físico na fase ICB em atletas. Objetivos: o objetivo desse estudo foi examinar os efeitos do programa de treinamento de Srint repetido na fase ICB em jogadores universitários de voleibol. Métodos: dezoito jogadores homens de voleibol foram aleatoriamente designados para um grupo experimental (n=9) ou um grupo controle (n=9) e completaram um programa tradicional de treinamento de voleibol três vezes por semana, durante seis semanas. O grupo experimental, adicionalmente, realizou um protocolo de treinamento de sprint repetido imediatamente antes de cada sessão de treinamento de voleibol. Antes e após o período de treinamento de 6 semanas, todos os participantes realizaram um teste de esteira experimental para determinar VT, RCP e consumo máximo de oxigênio (VO2max). As fases ICB foram calculadas como VO2 (ml/kg/min) e velocidade de corrida (km/h). Resultados: o grupo experimental mostrou melhorias significativas na fase ICB, RCP, VO2max e velocidade de corrida máxima depois do treino (p < 0.01). Não houve mudanças significativas no VT após o treino no grupo experimental (p > 0.05). Nenhuma das variáveis mudou significativamente no grupo controle (p > 0.05). Conclusões: a partir desses resultados, concluímos que o treinamento de Sprint repetido pode realçar a fase ICB em jogadores de voleibol, que podem ser atribuídos à melhora do efeito tampão, levando ao deslocamento da RCP para intensidades mais altas, sem nenhuma mudança no VT. O aumento na fase ICB pode ser um fator importante em relação à melhora na tolerância ao exercício de alta intensidade em atletas. Nível de evidência II, Estudos terapêuticos - Investigação dos resultados do tratamento.

RESUMEN Introducción: la región comprendida entre el umbral de ventilación (UV) y el punto de compensación respiratoria (PCR) se define como la fase de amortiguación isocapnica (ICB) y representa una fase de compensación de la acidosis metabólica inducida por el ejercicio. Hay poca literatura que examine los efectos del entrenamiento físico en la fase ICB de los atletas. Objetivos: El propósito de este estudio fue examinar los efectos del programa de entrenamiento de sprints repetidos en la fase ICB de los jugadores de voleibol de la universidad. Métodos: Dieciocho jugadores de voleibol masculino fueron asignados aleatoriamente a un grupo experimental (n=9) o un grupo de control (n=9) y completaron un programa tradicional de entrenamiento de voleibol, tres veces por semana durante 6 semanas. El grupo experimental también realizó un protocolo de entrenamiento de sprint repetido inmediatamente antes de cada sesión de entrenamiento de voleibol. Antes y después del período de entrenamiento de 6 semanas, todos los participantes realizaron una prueba incremental en cinta rodante para determinar UV, RCP y consumo máximo de oxígeno (VO2max). Las fases ICB se calcularon como VO2 (ml/kg/min) y velocidad (km/h). Resultados: El grupo experimental mostró mejoras significativas en la fase ICB, RCP, VO2max y velocidad de carrera máxima post entrenamiento (p < 0.01). No hubo cambios significativos en UV después del entrenamiento en el grupo experimental (p > 0.05). Ninguna de estas variables cambió significativamente en el grupo control (p > 0.05). Conclusiones: A partir de estos resultados, concluimos que el entrenamiento de sprints repetidos puede mejorar la fase ICB de los jugadores de voleibol, lo que puede atribuirse a la mejora de la capacidad de amortiguación que lleva al cambio de RCP a intensidades más altas sin ningún cambio en el UV. El aumento en la fase ICB puede ser un factor importante en relación con la mejora en la tolerancia al ejercicio de alta intensidad en atletas. Nivel de Evidencia II; Estudios terapéuticos - Investigando resultados del tratamiento.

Seasonal variations in body composition, maximal oxygen uptake, and gas exchange threshold in cross-country skiers.

INTRODUCTION: In order to ensure that athletes achieve their highest performance levels during competitive seasons, monitoring their long-term performance data is crucial for understanding the impact of ongoing training programs and evaluating training strategies. The present study was thus designed to investigate the variations in body composition, maximal oxygen uptake (VO2max), and gas exchange threshold values of cross-country skiers across training phases throughout a season. MATERIALS AND METHODS: In total, 15 athletes who participate in international cross-country ski competitions voluntarily took part in this study. The athletes underwent incremental treadmill running tests at 3 different time points over a period of 1 year. The first measurements were obtained in July, during the first preparation period; the second measurements were obtained in October, during the second preparation period; and the third measurements were obtained in February, during the competition period. Body weight, body mass index (BMI), body fat (%), as well as VO2max values and gas exchange threshold, measured using V-slope method during the incremental running tests, were assessed at all 3 time points. The collected data were analyzed using SPSS 20 package software. Significant differences between the measurements were assessed using Friedman's twoway variance analysis with a post hoc option. RESULTS: The athletes' body weights and BMI measurements at the third point were significantly lower compared with the results of the second measurement (p<0.001). Moreover, the incremental running test time was significantly higher at the third measurement, compared with both the first (p<0.05) and the second (p<0.01) measurements. Similarly, the running speed during the test was significantly higher at the third measurement time point compared with the first measurement time point (p<0.05). Body fat (%), time to reach the gas exchange threshold, running speed at the gas exchange threshold, VO2max, amount of oxygen consumed at gas exchange threshold level (VO2GET), maximal heart rate (HRmax), and heart rate at gas exchange threshold level (HRGET) values did not significantly differ between the measurement time points (p>0.05). CONCLUSION: VO2max and gas exchange threshold values recorded during the third measurements, the timing of which coincided with the competitive season of the cross-country skiers, did not significantly change, but their incremental running test time and running speed significantly increased while their body weight and BMI significantly decreased. These results indicate that the cross-country skiers developed a tolerance for high-intensity exercise and reached their highest level of athletic performance during the competitive season.

External Fixation Versus Hemiartroplasty In Unstable Intertrochanteric Hip Fractures Of The Elderly.

To compare two alternative methods : external fixation (EF) and hemiarthroplasty (HA) in elderly patients with unstable intertrochanteric hip fractures. Forty-two patients with Orthopaedic Trauma Association type 31A2-2 or 31A2-3 fractures treated between January 2007 and December 2010 were included. Twenty-two patients underwent hemiarthroplasty and twenty patients underwent external fixation. The mean length of stay in the operation room was 45 minutes and 108 minutes in the EF and HA groups, respectively (p<0.05). The mean postoperative length of hospital stay was 2.7 days in the EF group and 4.9 days in the HA group (p<0.05). The total length of hospital stay, functional scores and mortality rates were not different. Findings of the current study comparing EF and HA in a limited number of non-randomized elderly patients with unstable intertrochanteric fracture indicated that the EF method, when performed in a sufficiently stable manner, might be a valuable alternative to HA since it is less aggressive and cheaper.

An examination of respiratory and metabolic demands of alpine skiing.

BACKGROUND/OBJECTIVE: To measure the cardiorespiratory and metabolic variables during the giant slalom (GS) skiing activity under actual race conditions using a mobile gas analyzer. METHODS: This study included 20 voluntary male alpine ski racers (mean age, 22.00 ± 1.45 years) who participated in international races. First, incremental running test was conducted to obtain volunteers' maximal oxygen consumption (VO2max) values. Second, respiratory data were measured during their performance on the GS course. Before both GS performance and incremental running test and at 1 minute, 3 minutes, and 5 minutes after the tests, blood lactate concentration was measured. RESULTS: VO2max values of the volunteers were 51.36 ± 2.68 mL/kg/min and they used 74.96% of this during their performance on the GS course. Their blood lactate concentrations reached the maximum level of 13.69 ± 2.06 mmol/L at the 5th minute following the maximal exercise testing. After the GS performance, blood lactate values reached the maximum level of 10.13 ± 0.43 mmol/L at the 3rd minute. While the maximum heart rate was 196.5 ± 4.3 bpm during the maximal exercise testing, it reached 201.7 ± 20 bpm during the GS performance. CONCLUSION: It is observed that the GS race is a high-intensity activity and that high amount of anaerobic contribution is used by alpine ski racers during the GS race. By contrast, it is understood that the aerobic contribution is also at a considerable level during such an anaerobic activity as GS.