Fracturas de la base del quinto metatarsiano: ¿es útil mi tornillo de esponjosa con rosca parcial? Experiencia de 10 años / Fractures of the base of the fifth metatarsal bone: is my partially-threaded cancellous screw useful? 10-year experience

OBJETIVO Evaluar el resultado quirúrgico de fracturas de las zonas 2 y 3 de la base del quinto metatarsiano usando tornillos de esponjosa de diámetro de 4,0 mm con rosca parcial. MATERIALES Y MÉTODOS Evaluación retrospectiva de pacientes operados entre 2010 a 2019. Incluimos todos los casos sintetizados con este dispositivo con seguimiento mínimo de tresmeses, y excluimos casos operados con otros dispositivos y seguimiento menor a tres meses. Evaluamos la consolidació n y la presencia de complicaciones. Determinamos el largo del tornillo, el diámetro del canal endomedular, la distancia entre el borde proximal de la tuberosidad y la fractura, y la distancia de paso de la rosca sobre el rasgo de la fractura en radiografías anteroposterior (AP) y oblicua del pie. RESULTADOS Evaluamos 39 casos, y la muestra tenía una edad promedio de 27 años, y predominio del sexo masculino. El largo de tornillo más usado fue el de 45 mm, y los diámetros promedios del canal endomedular medidos en las radiografías AP y oblicua fueron de 4,6 mm y 3,96 mm, respectivamente. La distancia del borde de la tuberosidad hasta la fractura fue de 25,8 mm, y la distancia de paso de la rosca sobre el rasgo de la fractura fue en promedio de 24 mm. Hubo 100% de consolidación, en un promedio de 9,4 semanas, y 3 casos de retardo de consolidación, 2 de retroceso de tornillo, 1 de rosca intrafoco, y 1 de fractura cortical superior. No hubo retiros de tornillos a la fecha. DISCUSION No existe consenso respecto al tornillo ideal. La literatura internacional recomienda dispositivos intramedulares de diámetro de al menos 4,5 mm. Existen pocos reportes del uso de tornillos de diámetro de 4,0 mm. CONCLUSIONES El tornillo de esponjosa de diámetro de 4,0 mm con rosca parcial es una alternativa eficaz, segura y con baja tasa de complicaciones para el manejo de estas fracturas en nuestra población.

OBJETIVE To evaluate the surgical result of zone-2 and -3 fractures of the base of the fifth metatarsal bone using partially-threaded cancellous screws with a diameter of 4.0 mm. MATERIALS AND METHODS A retrospective evaluation of patients submitted to surgery between 2010 and 2019. We included all of the cases synthesized with this device with a minimum follow-up of three months, and excluded the cases operated on with other devices and follow-up shorter than three months. We evaluated the consolidation and the presence of complications, and determined, screw length, diameter of the endomedullary canal, the distance between the proximal edge of tuberosity and the fracture, and thread pitch over the fracture line on anteroposterior (AP) and oblique radiographs. RESULTS We evaluated 39 cases, and the sample had an average age of 27 years and male predominance. The most used screw length was 45 mm, and the average diameters of the medullary canal measured on the AP and oblique radiographs were of 4.6 mm and 3.96 mm respectively. The distance from the edge of the tuberosity to the fracture was of 25.8 mm, and the thread pitch over the fracture line was on average 24 mm. The rate of consolidation was of 100%, occurring in an average of 9.4 weeks, and there were 3 cases of consolidation delay, 2 of screw recoil, 1 of intrafocus thread, and 1 of superior cortex fracture. To date, there have been no cases of screw removal. DISCUSSION There is no consensus regarding the ideal screw. The international literature recommends intramedullary devices with a diameter of at least 4.5 mm. There are few reports of the use of screws with 4.0 mm in diameter. CONCLUSIONS The partially-threaded cancellous screw with a diameter of 4.0 mm is an effective and safe option, with a low complication rate for the management of these fractures.

Corrección del componente rotacional prequirúrgico y postquirúrgico del primer metatarsiano secundario a osteotomía de Chevron modificado / Correction of the pre- and post-surgical rotational component of the first metatarsal secondary to modified Chevron osteotomy

Resumen: Introducción: Hallux valgus (HV) es una patología compleja del antepié, recientemente se ha mostrado interés en el componente rotacional (CR) distal del primer metatarsiano por su relación con recidivas postquirúrgicas de la deformidad. La selección de la técnica quirúrgica es controversial con escasa literatura acerca de la corrección de rotación con osteotomías comunes. Nuestro objetivo es evaluar características radiológicas prequirúrgicas y postquirúrgicas respecto a CR del primer metatarsiano en la cirugía de corrección de HV moderado a severo usando osteotomía de Chevron largo. Material y métodos: Estudio observacional, prospectivo y comparativo en el que se evaluó el CR del primer metatarsiano en nueve pies pertenecientes a seis pacientes con una edad media de 45 años. El CR fue evaluado con base en la metáfisis proximal del primer metatarsiano en fluoroscopías axiales sin carga y AP de pie. Las mediciones se realizaron por un residente de ortopedia y traumatología y un subespecialista en cirugía de pie y Tobillo. Resultados: Se documentaron diferencias significativas (p = 0.05) en el ángulo de pronación prequirúrgico y postquirúrgico al utilizar osteotomía de Chevron largo. El resultado funcional de los pacientes evaluados fue excelente a 11 meses de seguimiento. Conclusiones: Radiológicamente, la corrección rotacional es variable y previamente no se ha reportado en la literatura con esta osteotomía. Se establecen bases morfológicas para la realización de estudios posteriores en la evaluación de rotación de cabeza del primer metatarsiano con diferentes osteotomías.

Abstract: Introduction. Hallux valgus (HV) is a complex forefoot pathology, in which interest has recently been shown in the distal rotational component (CR) of the first metatarsal due to its relationship with postsurgical relapses of the deformity. The selection of surgical technique is controversial with little current literature on the correction of rotation with common osteotomies. The aim of this study is to evaluate preoperative and postoperative radiological characteristics regarding CR of the first metatarsal using long Chevron osteotomy for moderate to severe HV. Material and methods: An observational, prospective and comparative study was carried out in which the CR of the first metatarsal was evaluated in nine feet belonging to six patients with a mean age of 45 years. The RC was evaluated based on the proximal metaphysis of the first metatarsal in axial fluoroscopies of unloaded metatarsals and standing AP. Measurements were performed by an Orthopedic and Traumatology resident and a Foot and Ankle Surgery subspecialist. Results: Significant differences (p = 0.05) were documented in the preoperative and postoperative pronation angle when using long Chevron osteotomy. The functional result of the evaluated patients was excellent at 11 months of follow-up. Conclusions: Radiologically, the rotational correction is variable and has not previously been reported in the literature with this osteotomy. We establishes the morphological bases for the performance of subsequent studies in the evaluation of head rotation of the 1st metatarsal with different osteotomies.

Intermittent vibrations accelerate fracture healing in sheep

Abstract Purpose: To investigate the effect of intermittent vibration at different intervals on bone fracture healing and optimize the vibration interval. Methods: Ninety sheep were randomized to receive no treatment (the control group), incision only (the sham control group), internal fixation with or without metatarsal fracture (the internal fixation group), and continuous vibration in addition to internal fixation of metatarsal fracture, or intermittent vibration at 1, 2, 3, 5, 7 and 17-day interval in addition to internal fixation of metatarsal fracture (the vibration group). Vibration was done at frequency F=35 Hz, acceleration a=0.25g, 15 min each time 2 weeks after bone fracture. Bone healing was evaluated by micro-CT scan, bone microstructure and mechanical compression of finite element simulation. Results: Intermittent vibration at 7-day interval significantly improved bone fracture healing grade. However, no significant changes on microstructure parameters and mechanical properties were observed among sheep receiving vibration at different intervals. Conclusions: Clinical healing effects should be the top concern. Quantitative analyses of bone microstructure and of finite element mechanics on the process of fracture healing need to be further investigated.

Correlation between ultrasound velocity and densitometry in fresh and demineralized cortical bone

OBJECTIVE: To compare ultrasound propagation velocity with densitometry in the diaphyseal compact cortical bone of whole sheep metatarsals. METHODS: The transverse ultrasound velocity and bone mineral density of 5-cm-long diaphyseal bone segments were first measured. The bone segments were then divided into four groups of 15 segments each and demineralized in an aqueous 0.5 N hydrochloric acid solution for 6, 12, 24 or 36 hours. All measurements were repeated after demineralization for each time duration and the values measured before and after demineralization were compared. RESULTS: Ultrasound velocity and bone mineral density decreased with demineralization time, and most differences in the pre- and post-demineralization values within each group and between groups were significant: A moderate correlation coefficient (r=0.75956) together with a moderate agreement was determined between both post-demineralization parameters, detected by the Bland-Altman method. CONCLUSION: We conclude that both ultrasound velocity and bone mineral density decrease as a result of demineralization, thus indicating that bone mineral content is of great importance for maintaining the acoustic parameters of cortical bone, as observed for cancellous bone. Ultrasound velocity can be used to evaluate both compact cortical bone quality and bone mineral density.

Point-Connecting Measurements of the Hallux Valgus Deformity: A New Measurement and Its Clinical Application

PURPOSE: The aim of this study was to investigate new point-connecting measurements for the hallux valgus angle (HVA) and the first intermetatarsal angle (IMA), which can reflect the degree of subluxation of the first metatarsophalangeal joint (MTPJ). Also, this study attempted to compare the validity of midline measurements and the new point-connecting measurements for the determination of HVA and IMA values. MATERIALS AND METHODS: Sixty feet of hallux valgus patients who underwent surgery between 2007 and 2011 were classified in terms of the severity of HVA, congruency of the first MTPJ, and type of chevron metatarsal osteotomy. On weight-bearing dorsal-plantar radiographs, HVA and IMA values were measured and compared preoperatively and postoperatively using both the conventional and new methods. RESULTS: Compared with midline measurements, point-connecting measurements showed higher inter- and intra-observer reliability for preoperative HVA/IMA and similar or higher inter- and intra-observer reliability for postoperative HVA/IMA. Patients who underwent distal chevron metatarsal osteotomy (DCMO) had higher intraclass correlation coefficient for inter- and intra-observer reliability for pre- and post-operative HVA and IMA measured by the point-connecting method compared with the midline method. All differences in the preoperative HVAs and IMAs determined by both the midline method and point-connecting methods were significant between the deviated group and subluxated groups (p=0.001). CONCLUSION: The point-connecting method for measuring HVA and IMA in the subluxated first MTPJ may better reflect the severity of a HV deformity with higher reliability than the midline method, and is more useful in patients with DCMO than in patients with proximal chevron metatarsal osteotomy.

First Metatarsal Proximal Opening Wedge Osteotomy for Correction of Hallux Valgus Deformity: Comparison of Straight versus Oblique Osteotomy

PURPOSE: The aim of this study was to compare clinical and radiographic outcomes of proximal opening wedge osteotomy using a straight versus oblique osteotomy. MATERIALS AND METHODS: We retrospectively reviewed 104 consecutive first metatarsal proximal opening wedge osteotomies performed in 95 patients with hallux valgus deformity. Twenty-six feet were treated using straight metatarsal osteotomy (group A), whereas 78 feet were treated using oblique metatarsal osteotomy (group B). The hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle, and distance from the first to the second metatarsal (distance) were measured for radiographic evaluation, whereas the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score was used for clinical evaluation. RESULTS: Significant corrections in the HVA, IMA, and distance from the first to the second metatarsal were obtained in both groups at the last follow-up (p<0.001). There was no difference in the mean IMA correction between the 2 groups (6.1+/-2.7degrees in group A and 6.0+/-2.1degrees in group B). However, a greater correction in the HVA and distance from the first to the second metatarsal were found in group B (HVA, 13.2+/-8.2degrees; distance, 25.1+/-0.2 mm) compared to group A (HVA, 20.9+/-7.7degrees; distance, 28.1+/-0.3 mm; p<0.001). AOFAS scores were improved in both groups. However, group B demonstrated a greater improvement relative to group A (p=0.005). CONCLUSION: Compared with a straight first metatarsal osteotomy, an oblique first metatarsal osteotomy yielded better clinical and radiological outcomes.