Study Design: Animal experimental model. Objective: To study the clinical behavior and histological changes in the spinal cord, nerve roots and perivertebral muscles of the spine after induced leakage of polymethylmethacrylate (PMMA) loaded with antiblastic drugs during vertebroplasty in an animal model of pigs. Methods: We performed vertebroplasty on 25 pigs. The animals were divided into 3 groups: vertebroplasty with PMMA alone (control group), vertebroplasty with PMMA loaded with methotrexate (MTX) and vertebroplasty with PMMA loaded with cisplatin (CYS). At 2 vertebral levels, epidural and prevertebral, massive cement leaks were induced. Animals were evaluated daily. Two weeks later, the pigs were sacrificed, and the tissues that came in contact with the cement were analyzed. Results: The clinical results for each of the groups were reported. The control group had no clinical alterations. In the MTX group, 2 pigs died before 1 week due to pneumonitis. In the CYS group, 4 animals had motor impairment, and 3 of the 4 had paraplegia. The histological results were as follows: the control and MTX groups showed synovial metaplasia, inflammatory reaction, crystal deposits, and giant cell reaction in the dura mater and muscle and all the animals in the CYS group had spinal cord and muscular necrosis. Conclusions: Massive cement leak after vertebroplasty with PMMA loaded with cisplatin is extremely toxic to the spinal cord and muscles around the spine. Therefore, its use cannot be recommended for the treatment of vertebral metastases. Using PMMA loaded with methotrexate seems to be a safe procedure, but further research is needed.

Purpose A question still remains as to whether constrictive toe-box shoes (TBS) cause disability only due to pain on pressure points or if they can cause permanent changes in the hallux anatomy. The aim of this study is to compare the hallux morphology in 3 groups classified according to their use of constrictive or open TBS. Methods 424 patients were classified into 3 groups: group A used open TBS daily; group B used constrictive TBS daily; group C used both open and constrictive TBS. Hallux's angles, presence of exostoses and shape of the distal phalanx (DP) were analyzed on dorsoplantar weight-bearing radiographs and compared amongst groups. Results The intermetatarsal (IMA), metatarsophalangeal (MTPA), DASA, PASA, interphalangeal (IPA), obliquity (AP1), asymmetry (AP2) and joint deviation (JDA) angles for group A were 10 degrees, 8 degrees, 5 degrees, 4 degrees, 9 degrees, 3 degrees, 5 degrees, 3 degrees; for group B were 9 degrees, 19 degrees, 5 degrees, 6 degrees, 12 degrees, 2 degrees, 8 degrees, 2 degrees; and for group C were 10 degrees, 10 degrees, 4 degrees, 4 degrees, 12 degrees, 3 degrees, 8 degrees, 1 degrees. Only the differences in the MTPA, IPA and AP2 were statistically significant (p < 0.05). The prevalence of exostoses on the tibial side of the DP was 22, 36, and 29% in groups A, B and C, respectively (p < 0.05). We found similar distributions of the different DP shapes in the three groups. Conclusions Our results suggest that the use of constrictive TBS, even if used only occasionally, could change hallux anatomy from a young age increasing MTPA, IPA and AP2. Moreover, we have found that DP exostoses are present as a "normal variation" in patients who wear an open TBS, but their prevalence is higher in those wearing constrictive toe-box shoes. This could be due to a reactive bone formation secondary to the friction caused by the inner border of the shoe. Level of clinical evidence 3.

Changes in vertebral body height depend on various factors which were analyzed in isolation and not as a whole. The aim of this study is to analyze what factors might influence the restoration of the vertebral body height after vertebral augmentation. We analyzed 48 patients (108 vertebrae) with osteoporotic vertebral fractures who underwent vertebral augmentation when a conservative treatment proved to be unsatisfactory. The analyses were carried out at the time of the fracture, during surgery (pre-cementation and post-cementation), at the first medical check-up (6 weeks post-surgery) and at the last medical check-up. The average vertebral height was measured, and the differences from the preoperative values were calculated at each timepoint. A Pearson correlation coefficient and a linear multivariable regression were carried out at different timepoints. The time since the vertebral fracture was 60.4 +/- 41.7 days. The patients' average age was 73.8 +/- 7 years. The total follow-up period was 1.43 +/- 1 year. After vertebral cementation, there was an increase in the vertebral body height of +0.3 cm (13.6%). During the post-operative follow-up, there was a progressive collapse of the vertebral body, and the pre-surgical height was reached. The factors that most influenced the vertebral height restoration were: a grade III collapse, an intervertebral-vacuum-cleft (IVVC) and the use of a flexible trocar before cement augmentation. The factor that negatively influenced the vertebral body height restoration was the location of the thoracolumbar spine.

Several studies have shown that double mobility (DM) cups reduce postoperative dislocations. Does the cemented dual mobility cup reduce dislocations in a specific cohort of elder patients with a high dislocation risk? Our hypothesis is that this implant is optimal for elder patients because it reduces early dislocation. We have retrospectively reviewed elder patients who underwent total hip arthroplasty (THA) with cemented double mobility cup between March 2009 and January 2018. The inclusion criteria were patients (>75 years) who were operated on for primary THA (osteoarthritis or necrosis) with a cemented dual mobility cup and a high-risk instability (at least two patient-dependent risk factors for instability). The exclusion criteria were revision surgeries or hip fracture. In all the cases, the same surgical approach was performed with a Watson Jones modified approach in supine position. We have collected demographic data, instability risk factors. Patients were classified using the Devane's score, Merle d'Aubigne score and the patient's likelihood of falling with the Morse Fall Scale. Surgical and follow-up complications were collected from their medical history. Sixty-eight arthroplasties (68 patients) were included in the study. The median age was 81.7 years (SD 6.4), and the American Society of Anesthesiologists (ASA) score showed a distribution: II 27.94%, III 63.24% and IV 8.82%. Devane's score was less than five in all of the cases. At least two patient-dependent risk factors for instability (87% had three or more) were present in each case. The median follow-up time was 49.04 months (SD 22.6). Complications observed were two cases of infection and one case of aseptic loosening at 15 months which required revision surgery. We did not observe any prosthetic dislocation. The cemented dual mobility cup is an excellent surgical option on primary total hip arthroplasties for elder patients with high-risk instability.

Background: The literature published about osteoid osteoma (OO) in the ankle-foot consists mainly on case reports. Methods: We performed a retrospective study in which we analyzed demographic parameters, pain characteristics, treatment options and functional outcomes measured using the AOFAS and the SEFAS scales. Results: We treated 17 patients with OO around the ankle-foot. Eighty-eight percent of patients had night pain that was relieved with NSAIDs. The bones most often affected were the talus and calcaneus. OO was diagnosed 21 months after the onset of symptoms. Mean follow-up was 17.3 years. The surgical techniques most used were curettage and curettage and bone grafting. There was a significant increase in AOFAS and SEFAS scores after surgery. Conclusions: Suspicion is the base of a prompt and a correct diagnosis of OO. The OO should be especially suspected in patients who present night pain that can be relieved with NSAIDs.

Introducción: Las técnicas para corregir las deformidades del hallux incluyen osteotomías metatarsianas y falángicas. Las osteotomías sobre la falange proximal corrigen el DASA y el ángulo interfalángico. Sin embargo, no se han publicado las indicaciones para la osteotomía de la falange distal. El objetivo de este artículo es comunicar la técnica y las indicaciones de la osteotomía percutánea de la falange distal del hallux, y evaluar los resultados de una serie de casos. Materiales y Métodos: Se analizaron 14 pies en los que se realizó una osteotomía de la falange distal del hallux para corregir una deformidad. Se midieron el DASA, la oblicuidad interfalángica y el ángulo falange distal-interfalángico en las radiografías. La técnica quirúrgica fue percutánea con control fluoroscópico. Los resultados se evaluaron mediante las escalas analógica visual de dolor y AOFAS. Seguimiento medio: 52 meses. Resultados: 13 pies de mujeres y un pie de hombre. Edad promedio: 58 años. Los resultados clínico y estético fueron excelentes, con alivio del dolor. Mejoría de la escala AOFAS: promedio 37 puntos. Análisis comparativo de ángulos preoperatorios y posoperatorios: DASA (p = 0,01), excepto cuando se aisló de la muestra a los pacientes con osteotomía tipo Akin (p = 0,33); ángulos F2-IF y F2-MTF (p <0,00001). Se registraron las complicaciones. Conclusiones: En la deformidad en valgo de la falange distal del hallux sintomática, se debe considerar una osteotomía correctora sola o asociada a osteotomía de la falange proximal. La osteotomía percutánea de la falange distal es un método eficaz, seguro y rápido. Nivel de Evidencia: IV

Background: Although different fixation techniques for the Akin osteotomy have been described in the literature, there are no many studies trying to analyze the differences between the types of fixation available. The aim of this study is to analyze if there are any differences between three types of staple fixation available in the market. Method: We present a retrospective study of 145 cases in which an Akin osteotomy was performed and fixed with three different kinds of implants staple A (28%), staple B (45%), and staple C (27%). Staple A is made out of stainless steel, and the surgeon mechanically controls the compression applied. Staple B increases the compression when heat is applied to it. Staple C has an intrinsic elastic memory that closes the osteotomy. In all cases, distal articular set angle, interphalangeal joint obliquity angle, and metatarsophalangeal angle were measured pre-operatively and 1.5 months post-operatively on dorsoplantar weight-bearing radiographs. Other details such as post-operative complications, implant migration, osteolysis, or fracture of the lateral cortex during surgery were also recorded. Results: Clinical and radiological results show no relevant differences between the three types of fixation. The mean angular corrections of DASA, interphalangeal joint obliquity angle, and metatarsophalangeal angle were 5, 12, and 21, respectively, for staple A; 4, 10, and 19, respectively, for staple B; and 7, 10, and 23, respectively, for staple C. The rates of intra-operative and post-operative complications were similar for all groups. There was one case of infection per group. We had five cases of delayed union two with staple A and three with staple C. In four cases, there was a loss of correction, two of them fixed with staple A and two with staple C. Seven cases developed a Südeck's syndrome, four of them fixed with staple A and three with staple C. Fifteen patients suffered an uncontrolled fracture of the lateral cortex of the phalanx when performing the osteotomy (3, 8, and 4 cases fixed with staples A, B, and C, respectively), and 87.5% of the patients that developed a plantar displacement of the osteotomy had an uncontrolled fracture of the lateral cortex (p < 0.05). All three staples achieved a rigid internal fixation and minimal periosteum damage and provided a good bone-bone contact. Conclusions: According to our results, the radiological differences are minimal, and although the thermal compression staple had less complication, clinical differences were also not statistically significant. This means the choice of implant could be left to the surgeon's preferences or made according to cost.

Background: To describe the feasibility of the posterior arch of C2 accepting two crossing screws in the Spanish population. Methods: One hundred and fifty patients who underwent a routine neck CT scan for non-cervical pathology were enrolled. Submillimeter slices (thickness 0.7 mm) every 0.4 mm were performed with a 64 multi-detector CT scan, which allows isometric measurements. We measured the length and height of the cortical and cancellous (endomedullar) region of the lamina and the spinous process, inclination, maximal screw length and spinolaminar angle. Results: The average (standard deviation) measurements of the lamina were: width of the left cortical 7.2 (1.5) mm, right cortical 6.9 (1.3) mm, width of the cancellous part of the left lamina 4.8 (1.5) mm, right side 4.6 (1.4) mm. The mean left cortical height was 13.0 (1.5) mm and 13.1 (1.6) mm for the right. The mean height of the cancellous part was 9.0 mm for both sides. The average measurements of the spinous process were: cortical length 15.7 (3.5) mm, endomedullar length 12.5 (3.9) mm; cortical height 11.9 (2.2) mm, endomedullar height 8.4 (2.1) mm; spinolaminar angle 49º (4); the maximum screw length 3.18 cm, and the inclination angle 143º. Conclusion: A CT scan with submillimeter slices is necessary in order to avoid malpositioning of the screws. The outer cortical measurements are 2 to 4 mm bigger than the endomedullar ones. Taking into account the dimensions of the spinous process, 24% of the population would not be candidates for this crossing screw technique.

Capítulo sobre fracturas vertebrales y sacro dentro del Master Online en CIrugía de la Columna. Consta de 23 páginas de Texto, bibliografía, 2 videos de casos clínicos, 2 videos de técnicas quirúrgicas y 7 preguntas de autoevaluación.