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PURPOSE: The aim of this study was to determine the change in the long leg axis according to the preoperative knee phenotype using the mechanically aligned extension-first technique in total knee arthroplasty. The hypothesis of this study was that the knee phenotype would have an impact on the postoperative leg axis. METHODS: This was a retrospective comparative study comprising 224 whole-leg radiographs of 112 patients. The leg axes of the pre- and postoperative radiographs were measured and categorized into three preoperative limb phenotypes (based on the hip-knee-ankle angle [HKA]) according to Hirschmann et al. (varus-HKA < 178.5°, neutral-HKA 178.5°-181.5°, and valgus-HKA > 181.5°). Additionally, femoral phenotypes (based on the femoral mechanical angle [FMA], i.e., the mechanical medial distal femoral angle [mMDFA], as well as the tibial phenotypes [based on the tibial mechanical angle, i.e., the medial proximal tibial angle (MPTA)] was calculated. The change in the long leg axis was analyzed and compared with the preoperative limb phenotype. RESULTS: Significantly more patients with preoperative varus alignment shifted to neutral alignment (46.3%, n = 31) than did patients with preoperative valgus alignment (38.9%; n = 14). Moreover, 43.3% of patients (n = 29) with the varus phenotype remained in a varus alignment, compared with the 58.3% of patients with preoperative valgus phenotype (n = 21) remaining in valgus alignment. These findings were similar for both females (p < 0.001) and males (p = 0.015). CONCLUSION: Using an extension-first mechanically aligned surgical technique, varus phenotypes predominantly result in neutral leg axes or remain varus, neutral phenotypes remain neutral, and valgus phenotypes remain valgus or change to neutral phenotypes. This study showed that preoperative knee phenotypes in valgus knees influence this technique more strongly than estimated in previous investigations, which is in line with modern alignment philosophies for TKA. LEVEL OF EVIDENCE: Level IV, retrospective comparative study.

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Objective To evaluate the biomechanical properties of the "figure-of-eight" and Kessler suture techniques for tendons. Methods Flexor tendons of porcine fingers were divided into two groups with triple central "figure of eight" sutures (six passages) and Kessler sutures (two passages) associated with simple and continuous peripheral sutures, and submitted to continuous longitudinal mechanical tests, to obtain the mechanical properties of maximum load and energy at maximum load. Results The mean maximum load and energy at maximum load in the "figure-of-8" suture were of 63.4 N and 217.3 N.mm respectively; in the Kessler suture, the values were of 34.19 N and 100.9 N.mm respectively. The statistical analysis indicated that the "figure-of-eight" suture is mechanically superior to the Kessler technique. Conclusion Under the conditions of this experiment and in the flexor tendon of porcine fingers, the triple "figure-of-eight" suture (six passages) is more resistant than the Kessler suture (two passages). The "figure-of-eight" suture with six passages enables active movement in the immediate rehabilitation of the flexor tendon repair of the finger, with little risk of rupture or suture spacing.

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Abstract Objective To evaluate the biomechanical properties of the "figure-of-eight" and Kessler suture techniques for tendons. Methods Flexor tendons of porcine fingers were divided into two groups with triple central "figure of eight" sutures (six passages) and Kessler sutures (two passages) associated with simple and continuous peripheral sutures, and submitted to continuous longitudinal mechanical tests, to obtain the mechanical properties of maximum load and energy at maximum load. Results The mean maximum load and energy at maximum load in the "figure-of-8" suture were of 63.4 N and 217.3 N.mm respectively; in the Kessler suture, the values were of 34.19 N and 100.9 N.mm respectively. The statistical analysis indicated that the "figure-of-eight" suture is mechanically superior to the Kessler technique. Conclusion Under the conditions of this experiment and in the flexor tendon of porcine fingers, the triple "figure-of-eight" suture (six passages) is more resistant than the Kessler suture (two passages). The "figure-of-eight" suture with six passages enables active movement in the immediate rehabilitation of the flexor tendon repair of the finger, with little risk of rupture or suture spacing.

Resumo Objetivo Avaliar as propriedades biomecânicas dos pontos de sutura tendinosa em "oito" e de Kessler. Métodos Tendões flexores dos dedos de membros superiores de porcos foram divididos em dois grupos com suturas triplas centrais em "oito" (seis passagens) e de Kessler (duas passagens) associadas a suturas periféricas contínuas simples, e submetidos a ensaios mecânicos longitudinais contínuos, obtendo-se as propriedades mecânicas de carga máxima e de energia na carga máxima. Resultados As médias da carga máxima e da energia na carga máxima na sutura em "8" foram de 63,4 N e 217,3 Nmm, respectivamente; na sutura de Kessler, os valores foram de 34,19 N e 100,9 Nmm, respectivamente. A análise estatística indicou que o ponto em "oito" é superior mecanicamente ao ponto de Kessler. Conclusões Nas condições deste experimento e no tendão flexor de dedo de membro superior de porcos, o triplo ponto em "oito" (seis passagens) é mais resistente do que o ponto de Kessler (duas passagens). O triplo ponto em "oito", com seis passagens, permite movimentação ativa na reabilitação imediata de reparo de tendão flexor de dedo de membro superior com pouco risco de ruptura ou espaçamento na sutura.

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Resumo O objetivo do estudo foi determinar o efeito de 14 semanas de treinamento de força com periodização linear (PL) e ondulatória diária (POn) no desempenho através da avaliação cinemática das variáveis frequência de braçada (FB), comprimento de braçada (CB), velocidade média (VM) e índice de braçada (IB) em nadadores jovens de ambos os sexos. Foram divididos 17 adolescentes (15,18 ± 2,31 anos) em dois grupos (G): GPL (quatro homens e quatro mulheres) e GPOn (cinco homens e quatro mulheres). Pelos resultados encontrados podemos concluir que a POn é mais eficaz em proporcionar melhorias nos aspectos cinemáticos de VM, IB e CB em distâncias mais curtas (até 50 metros). A PL foi mais eficiente na manutenção da resistência muscular em variáveis de VM e CB em distâncias maiores (acima de 50 metros).

Abstract The purpose of the study was to determine the effect of 14 weeks of strength training with linear periodization (LP) and daily undulatory periodization (DUP) in performance by kinematics of the variables stroke rate (SR), stroke length (SL), speed average (SA) and stroke index (SI) in young swimmers of both sexes. Seventeen children (15.18 ± 2.31 years) were divided into two groups (G): GLP (4 males and 4 females) and GDUP (5 males and 4 females). For the results we conclude that DUP is more effective to provide improvements in the kinematic aspects of SA, SI, and shorter distances (up to 50 meters). LP is more efficient in maintaining muscle strength SL and SA variables at greater distances (over 50 meters).

Resumen El objetivo de este estudio fue determinar el efecto de 14 semanas de entrenamiento de fuerza con periodización lineal (PL) y periodización ondulante diaria (POn) en el rendimiento de las variables cinemáticas de frecuencia de brazada (FB), longitud de brazada (LB), velocidad media (VM) e índice de brazadas (IB) en nadadores jóvenes de ambos sexos. Se dividió a 17 chicos (15,18 ± 2,31 años) en dos grupos (G): GPL (4 hombres y 4 mujeres) y GPOn (5 hombres y 4 mujeres). Respecto a los resultados, se concluye que POn proporciona mejoras de manera más eficaz en los aspectos cinemáticos de VM, LB e IB y en distancias más cortas (hasta 50 m). PL es más eficaz en el mantenimiento de la fuerza muscular y las variables VM y LB a distancias mayores (más de 50 m).

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BACKGROUND: Synthetic sutures such as Fiberwire used in flexor tendon repairs have high tensile strength. Proper application allows early mobilisation, decreasing morbidity from repair rupture and adhesions while preserving range of motion. Suture stiffness can cause poorer knot holding, contributing to gapping, peritendinous adhesions or rupture. Previous studies recommended more throws in knots tied on Fiberwire to prevent knot slippage. These larger knots are voluminous and prominent. In tendon repairs they can cause "catching", increase friction and work of flexion. Other studies advocated certain complicated knots as being more secure. We evaluated several knots and their biomechanical properties with the aim of finding a compact knot with less potential for slippage to maximise strength potential of flexor tendon repairs using Fiberwire. METHODS: A series of different knots tied on Fiberwire 4-0 sutures were pulled to failure on a mechanical tester. Mean tensile strengths, knot volumes and tensile strength to knot volume ratios were compared. RESULTS: Tensile strengths and knot volume increased with more throws and loops. Four variations of the square knot (the 4=4=1, 2=2=2=2, 1=1=1=1=1, 2=1=1=1=1 knots) had tensile strengths greater than 35N. The specialised anti-slip knot had highest tensile strength and suture volume but lower strength-to-volume ratio. CONCLUSIONS: The anti-slip knot had highest tensile strength but it also had the highest volume. The greater strength of repair may not translate into improved clinical outcome. The 1=1=1=1=1 knot has superior knot strength-to-volume ratio with good knot strength adequate for early active mobilisation in flexor tendon repairs.

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