Evaluation of the Chilean National Orthopaedic Examination Over 11 Years: Progress and Outcomes of National and International Examinees.

INTRODUCTION: The National Orthopaedics Examination (EMNOT) was initially designed for Chilean orthopaedic program graduates and is now a crucial component of the revalidation process for international orthopaedic surgeons seeking practice in Chile. This study aims to describe participation and performance of EMNOT examinees based on their origin and to analyze the difficulty and discrimination indexes during its first 11 years of implementation. METHODS: A retrospective assessment was conducted on all EMNOT results from 2009 to 2019. The study evaluated the participation and performance of examinees according to their origin and examined the difficulty and discrimination indexes of the examination. RESULTS: A total of 975 examinees were evaluated, with 41.23% from national resident programs (National Medical Graduates) and 58.77% from international examinees (International Medical Graduates). The number of participating universities increased from 4 in 2009 to 17 in 2019. National Medical Graduates examinees achieved a mean score of 66.52 ± 8.67 (0 to 100 points) while International Medical Graduates examinees scored 55.13 ± 11.42 (P < 0.001). The difficulty and discrimination indexes remained adequate throughout this period. DISCUSSION: Over the course of 11 years, the number of EMNOT examinees exhibited notable growth. The examination effectively differentiates between candidates based on their origin and maintains appropriate levels of difficulty and discrimination.

Tibial tubercle to trochlear groove and the roman arch method for tibial tubercle lateralisation are reliable and distinguish between subjects with and without major patellar instability.

PURPOSE: Patellofemoral (PF) instability recurrence depends on several factors including the relative lateralisation of tibial tubercle (TT) regarding the trochlear groove (TG). TT relative lateralisation quantification has long been a topic of debate. Multiple measuring techniques have been described including TT-trochlear groove (TT-TG), TT-posterior cruciate ligament (TT-PCL) and TT-roman arch (TT-RA), with no clear consensus regarding the most reliable index or pathologic threshold. We set out to determine the normal value range of each index and their association with age, sex and PF instability status. Also, this study aims to determine a reliable pathologic distance threshold to effectively predict patellar dislocation. METHODS: Skeletally mature patients up to 45 years of age who presented a CT Scan and an MRI of the same knee between 2014 and 2018 were included and divided into subgroups based on history of PF instability. Three indexes (TT-TG, TT-PCL and TT-RA) were assessed by two independent observers blinded to instability history. ROC curves were performed for each index to obtain the cut point that better predicts instability. Univariate and multivariate models adjusted by age, sex, instability history and type of imaging technique were performed to test the influence of these variables. RESULTS: 208 patients were included. Mean age was 27.93 â€‹± â€‹8.48 years, 67.3% were female and 71 patients (34.1%) presented major instability history. Good or excellent inter and intraobserver reliability was found for all three indexes. All indexes presented significantly different distributions between subjects with and without major instability (p â€‹< â€‹0.001), except for TT-PCL. Different cut point values differing between imaging modalities were found: 11.4 â€‹mm for MRI TT-TG, 17 â€‹mm for CT TT-TG, 15.6 â€‹mm for MRI TT-RA and 18.2 â€‹mm for CT TT-RA. CONCLUSIONS: All indexes studied had good or excellent inter and intraobserver reliability. Measurements between imaging techniques (CT and MR) are not interchangeable. Both TT-TG and TT-RA correctly distinguish between subjects with and without major instability, while TT-PCL does not, recommending caution when evaluated on its own. Specific threshold values depending on imaging technique should be considered for surgical decision-making. LEVEL OF EVIDENCE: Level IV, Diagnostic Test.

The distance between the fibular collateral ligament tunnel and the common peroneal nerve allows a posterolateral corner reconstruction without neurolysis.

PURPOSE: The most popular knee posterolateral corner (PLC) reconstruction techniques describe that a common peroneal nerve (CPN) neurolysis must be done to safely address the posterolateral aspect of the knee. The purpose of this study was to measure the distance between the CPN and the fibular insertion of the FCL in different degrees of knee flexion in cadaveric specimens, to identify if tunnel drilling could be done anatomically and safely without a CPN neurolysis. METHODS: Ex vivo experimental analytical study. Ten fresh frozen human knees were dissected leaving FCL and CPN in situ. Shortest distance from the centre of the FCL distal tunnel and CPN was measured (antero-posterior and proximal-distal wire-nerve distances) at 90°, 60°, 30°, and 0° of knee flexion. Measurements between different flexion angles were compared and correlation between knee flexion angle and distance was identified. RESULTS: The mean distance between the FCL tunnel and the CPN at 90° were 21.15 ± 6.74 mm posteriorly (95% CI: 16.33-25.97) and 13.01 ± 3.55 mm distally (95% CI: 10.47-15.55). The minimum values were 9.8 mm posteriorly and 8.9 mm, respectively. These distances were smaller at 0° (p ≤ 0.017). At 90° of knee flexion, the mean distance from the fibular tip to the CPN distally was 23.46 ± 4.13 mm (20.51-26.41). CONCLUSION: Anatomic localization and orientation of fibular tunnels can be done safely while avoiding nerve neurolysis. Further studies should aim to in vivo measurements and results.

Tibial Cut Accuracy in Mechanically Aligned Total Knee Arthroplasty Using Extensor Hallucis Longus Tendon to Determine Extramedullary Tibial Guide Position.

This study aimed to determine the tibial cut (TC) accuracy using extensor hallucis longus (EHL) tendon as an anatomical landmark to position the total knee arthroplasty (TKA) extramedullary tibial guide (EMTG), and its impact on the TKA mechanical alignment (MA). We retrospectively studied 96 TKA, performed by a single surgeon, using a femoral tailored intramedullary guide technique. Seventeen were prior to the use of the EHL and 79 used the EHL tendon to position the EMTG. We analyzed preoperative and postoperative standing total lower extremity radiographs to determine the tibial component angle (TCA) and the correction in MA, comparing pre-EHL use and post-EHL technique incorporation. Mean TCA was 88.89 degrees and postoperative MA was neutral in 81% of patients. Pre- and postoperative MAs were not correlated. As a conclusion of this study, using the EHL provides a safe and easy way to determine the position of EMTG.

An Isolated Transosseous Flexible Suture Frame in the Treatment of Patellar Tendon Rupture Provides Adequate Mechanical Resistance.

INTRODUCTION: Acute patellar tendon ruptures are frequently observed in patients with metabolic comorbidities, and the benchmark treatment is surgical repair. It is desirable not to harm an already fragile biologic environment with sutures and hardware. We aimed to compare the mechanical requirements of an isolated, flexible, high-strength nonabsorbable transosseous suture frame with that of the Krackow suture technique. METHODS: A total of 12 cadaveric pieces were randomized into two groups: the isolated flexible frame group (n = 6) and the standard Krackow fixation group (n = 6). A traumatic rupture of the patellar tendon was performed, and a transosseous displacement sensor was installed on a validated biomechanical system. Gap formation was measured during 50 cycles of flexion and extension with traction on the quadriceps (250 N). Subsequently, specimens underwent progressive loading in a fixed flexion position until failure occurred. The data were analyzed using nonparametric statistical tools with a significance level of 5%. RESULTS: The isolated frame group had a smaller gap formation (1.7 mm) than the Krackow group (3.4 mm; P = 0.01). No significant difference existed in the median failure end points of the two groups (676 and 530 N, respectively; P = 0.11). DISCUSSION: Patellar tendon repair using an isolated, transosseous, flexible, suture frame outperformed using the traditional Krakow repair technique in gap formation. Further studies are needed to determine if this will result in better functional outcomes or fewer clinical failures. LEVEL OF EVIDENCE: Level IV, experimental case series.

Anterior and distal tunnel orientation for anatomic reconstruction of the medial patellofemoral ligament is safer in patients with open growth plates.

PURPOSE: In patients with open growth plates, the direction of tunneling that avoids distal femoral physis (DFP) damage in anatomic reconstructions of the medial patellofemoral ligament (MPFL) has been a topic of discussion. The objective of this study was to determine the ideal orientation for anatomic reconstructions of MPFL tunneling that minimized DFP damage while avoiding breaching the intercondylar notch. METHODS: Eighty magnetic resonance images of patients aged 10 through 17 were obtained, randomly sampled from the institutional database. A de novo software was developed to obtain 3D models of the distal femur and DFP. In each model, the anatomical insertion point of the MPFL was determined as defined by Stephen. A 20-mm-depth drilling was simulated, starting from the insertion point at every possible angle within a 90° cone using 5-, 6- and 7-mm drills. Physeal damage for each pair of angles and each drill size was determined. Damage was expressed as a percentage of total physis volume. Statistical analysis was conducted using Student's t test and one-way ANOVA. RESULTS: Maximum physeal damage (5.35% [4.47-6.24]) was obtained with the 7-mm drill when drilling 3° cephalic and 15° posterior from insertion without differences between sexes (n.s.). Minimal physeal damage (0.22% [0.07-0.37]) was obtained using the 5-mm drill aimed 45° distal and 0° anteroposterior, not affected by sex (n.s.). Considering intra-articular drilling avoidance, the safest zone was obtained when aiming 30°-40° distal and 5°-35° anterior, regardless of sex. CONCLUSION: Ideal femoral tunnel orientation, avoiding physeal damage and breaching of the intercondylar notch, was obtained when aiming 30°-40° distal and 5°-35° anterior, regardless of sex. This area is a safe zone that allows anatomic MPFL reconstruction of patients with an open physis.

Umbilical Cord-Derived Mesenchymal Stromal Cells (MSCs) for Knee Osteoarthritis: Repeated MSC Dosing Is Superior to a Single MSC Dose and to Hyaluronic Acid in a Controlled Randomized Phase I/II Trial.

Knee osteoarthritis (OA) is a leading cause of pain and disability. Although conventional treatments show modest benefits, pilot and phase I/II trials with bone marrow (BM) and adipose-derived (AD) mesenchymal stromal cells (MSCs) point to the feasibility, safety, and occurrence of clinical and structural improvement in focal or diffuse disease. This study aimed to assess the safety and efficacy of the intra-articular injection of single or repeated umbilical cord-derived (UC) MSCs in knee OA. UC-MSCs were cultured in an International Organization for Standardization 9001:2015 certified Good Manufacturing Practice-type Laboratory. Patients with symptomatic knee OA were randomized to receive hyaluronic acid at baseline and 6 months (HA, n = 8), single-dose (20 × 106 ) UC-MSC at baseline (MSC-1, n = 9), or repeated UC-MSC doses at baseline and 6 months (20 × 106 × 2; MSC-2, n = 9). Clinical scores and magnetic resonance images (MRIs) were assessed throughout the 12 months follow-up. No severe adverse events were reported. Only MSC-treated patients experienced significant pain and function improvements from baseline (p = .001). At 12 months, Western Ontario and Mc Master Universities Arthritis Index (WOMAC-A; pain subscale) reached significantly lower levels of pain in the MSC-2-treated group (1.1 ± 1.3) as compared with the HA group (4.3 ± 3.5; p = .04). Pain Visual Analog scale was significantly lower in the MSC-2 group versus the HA group (2.4 ± 2.1 vs. 22.1 ± 9.8, p = .03) at 12 months. For total WOMAC, MSC-2 had lower scores than HA at 12 months (4.2 ± 3.9 vs. 15.2 ± 11, p = .05). No differences in MRI scores were detected. In a phase I/II trial (NCT02580695), repeated UC-MSC treatment is safe and superior to active comparator in knee OA at 1-year follow-up. Stem Cells Translational Medicine 2019;8:215&224.

An assessment of the Chilean National Examination of Orthopaedic Surgery.

BACKGROUND: The Chilean National Examination of Orthopaedic Surgery (EMNOT) has been administered since 2009. It was developed to determine whether individual residents are meeting minimal knowledge standards at the end of their training programs. METHODS: We performed a retrospective evaluation of the EMNOT for all years it has been administered (2009-2015). The test was analyzed for content, taxonomy of questions asked (1: direct recall; 2: diagnosis; 3: evaluation/decision-making), residents' performance, difficulty index and discrimination index. RESULTS: During the years of EMNOT administration, the most frequently tested areas have been pediatric orthopaedics (22.9 %), spine (13.8 %), general orthopaedics (13.8 %) and musculoskeletal trauma (9.9 %). A significant increase in questions with images was observed, as well as a significant decrease in the percentage of Type 1 and an increase in Type 3 questions. The Difficulty Index showed a medium level of difficulty for all years the examination has been administered. The Discrimination Index showed good discrimination in 2009, fair discrimination from 2010 through 2012, and excellent discrimination from 2013 through 2015. CONCLUSION: The EMNOT has evolved over several years to include better quality questions, better discrimination, and a more representative distribution of questions covering the different orthopaedic sub-specialties. This examination represents an effective instrument for quality assurance of orthopaedic residency programs in Chile.

Is computed tomography an accurate and reliable method for measuring total knee arthroplasty component rotation?

PURPOSE: Computed tomography (CT) is widely used to assess component rotation in patients with poor results after total knee arthroplasty (TKA). The purpose of this study was to simultaneously determine the accuracy and reliability of CT in measuring TKA component rotation. METHODS: TKA components were implanted in dry-bone models and assigned to two groups. The first group (n = 7) had variable femoral component rotations, and the second group (n = 6) had variable tibial tray rotations. CT images were then used to assess component rotation. Accuracy of CT rotational assessment was determined by mean difference, in degrees, between implanted component rotation and CT-measured rotation. Intraclass correlation coefficient (ICC) was applied to determine intra-observer and inter-observer reliability. RESULTS: Femoral component accuracy showed a mean difference of 2.5° and the tibial tray a mean difference of 3.2°. There was good intra- and inter-observer reliability for both components, with a femoral ICC of 0.8 and 0.76, and tibial ICC of 0.68 and 0.65, respectively. CONCLUSIONS: CT rotational assessment accuracy can differ from true component rotation by approximately 3° for each component. It does, however, have good inter- and intra-observer reliability.

Effect of cyclic tension on the biomechanical properties of flexor tendon grafts. Results of an ex-vivo porcine study.

BACKGROUND: Autologous flexor tendons are widely used for anterior cruciate ligament (ACL) reconstruction. Pretension of the graft before fixation has been described as part of the surgical technique, nevertheless there is no consensus on the type and amount to tension needed to increase the stiffness without affecting its biomechanical properties.Our hypothesis is cyclic tension increases flexor tendon stiffness without affecting its ultimate failure at maximum loads (UFML). METHODS: Forty-five flexor digitorum profundus tendons harvested from domestic pigs (Sus scrofa domestica) were randomly divided into three groups: E1 (n=15), E2 (n=15) and C (n=15). Groups E1 and E2 were subjected to 50 cyclic loads at a 1 Hz frequency, at 70N and 100N respectively, group C was not intervened. The three groups were then tested for UFML. Cyclic loads and measurements were performed using a Stress-Strain machine (SST 1.0 Kinetecnic). Results were analyzed using GrapgPad statistical software. Groups were compared using Mann-Whitney test with a 95% confidence interval. RESULTS: Significant increased stiffness for group E1 (p=0.02) and group E2 ( p<0.01) when compared to group C. The stiffness of group E2 was also significantly higher than E1 (p=0.03). There was a significant reduction on the UFML between group E2 and C (p<0.01), which was not observed when comparing groups E1 and C. CONCLUSION: Cyclic loads at 70N result in an increased stiffness of flexor tendons without affecting its ultimate failure at maximum loads. Cyclic loads at higher tensions might cause a deleterious effect on the biomechanical properties of flexor tendon grafts.

Treatment of patellofemoral chondropathy with the Bandi tibial tubercle osteotomy More than 10years follow-up.

Isolated degenerative patellofemoral chondropathy is a prevalent disease. There is still controversy regarding its ideal type of management. A retrospective study was performed to assess the outcomes of 28 patients with a minimum of 10-year follow-up, in whom the Bandi tibial tubercle osteotomy was performed. The Bentley score was applied pre and postoperatively to evaluate the clinical results. Preoperatively, 21 (67%) patients were rated as fair and seven (33%) as poor according to the Bentley functional scale for patellofemoral osteoarthritis. At 5 years of follow-up, one case was rated as excellent, 23 (81%) cases as good, three as fair and one as poor. At 10 years of follow-up no cases were rated as excellent, 17 (61%) cases as good, four (14%) as fair and seven (25%) as poor. The difference in terms of poor results evaluated at five and 10 years after the surgery was statistically significant (p<0.05). We concluded that excellent and good short-term results can be expected with the use of the Bandi tibial tubercle osteotomy in patients with isolated degenerative patellofemoral chondropathy; however, such outcomes tend to deteriorate over the time, especially in patients with advanced chondromalacia, making its indication controversial.

Effects of platelet concentrate and a bone plug on the healing of hamstring tendons in a bone tunnel.

PURPOSE: The purpose of this study was to determine if the use of platelet concentrate (PC) and bone plug (BP) does accelerate the healing process in anterior cruciate ligament (ACL) reconstruction. METHODS: One hundred and eight patients requiring ACL reconstruction were prospectively randomized into 4 groups: control (27 patients), PC (26 patients), BP (28 patients), and a combination of PC and BP (27 patients). Magnetic resonance imaging (MRI) studies were carried out at both 3 and 6 months postsurgery. Maturation of the graft was evaluated at the femoral tunnel using MRI maturation criteria defined by a low-intensity signal, absence of osteoligamentous interface, and no widening of the femoral tunnel. RESULTS: Three months after surgery, no differences were found among the groups regarding MRI maturation criteria. Six months postsurgery, 78% of the patients in the control group had a low-intensity signal, while in the PC group the low-intensity signal was present in 100% of the patients (P = .036). No statistical differences were observed regarding the osteoligamentous interface between the various groups. Finally, tunnel widening was seen in 11% of the patients of the BP group versus 41% of the patients in the control group (P = .047), but no statistical difference was seen with the other groups. CONCLUSIONS: The use of PC had an enhancing effect on the graft maturation process evaluated only by MRI signal intensity, without showing any significant effect in the osteoligamentous interface or tunnel widening evolution. The use of a BP effectively prevented tunnel widening. The BP and PC combination did not show a synergic effect as compared to PC or BP individually. LEVEL OF EVIDENCE: Level II, lesser quality randomized controlled trial.

Tratamiento neuroquirúrgico de la agresividad irreductible: hipotalamotomía posteromedial estereotáxica / Stereotaxic posteromedial hypothalamotomy in the treatment of aggressive behaviour: a clinical case

Introducción: se describe el caso de un paciente de 30 años, portador de trastorno orgánico de la personalidad, que presentaba frecuentes accesos de agresividad patológica subtipo predatorio hacia otras personas. Estos episodios de descontrol fueron esporádicos en la infancia; a partir de los 15 años el síndrome fue empeorando a pesar de los tratamientos instituidos, siendo las crisis de agresividad imprevisibles cada vez más frecuentes y violentas. Se emplearon sucesivamente y en forma combinada terapéuticas farmacológicas (neurolépticos, antipsicóticos, benzodiacepinas, estabilizadores y betabloqueantes) a dosis plenas y en rango variable, electroconvulsoterapia y múltiples terapias de rehabilitación. Ante el fracaso terapéutico convencional se planteó como último recurso la neurocirugía. Procedimiento: la cirugía que se llevó a cabo fue una hipotalamotomía posteromedial bilateral estereotáxica por radiofrecuencia, bajo anestesia general, realizando la localización de los blancos a tratar con tomografía computada. No se observaron complicaciones posoperatorias. Resultados: en las semanas siguientes al posoperatorio el paciente se mantuvo en situación de mansedumbre, lo que permitió modificar el programa farmacológico, con suspensión de la megadosis de psicofármacos (haloperidol, olanzapina, lorazepam) y betabloqueantes (propranolol), y mantención del timorregulador anticomicial (valproato). En la evolución inmediata se reintegra precozmente y sin incidentes a la terapia grupal de rehabilitación y a actividades sociales con su familia. En la evolución diferida recupera paulatinamente rasgos personales y capacidades previas al comienzo de la refractariedad. La condición de mejoría clínica, respecto al objetivo del control de la agresividad patológica subtipo predatorio y la mejoría de la calidad de vida del paciente y su familia se mantienen durante el seguimiento de nueve meses, por lo que se decide publicar el reporte.

Tratamiento artroscopico del pellizcamiento femoroacetabular: tecnica quirurgica y resultados preliminares / Arthroscopic treatment of femoroacetabular impingement: surgical technique and early results

La articulacion de la cadera puede ser origen de dolor y limitacion funcional. Entre otros diagnosticos se encuentra el pellizcamiento femoroacetabular. El diagnostico de pellizcamiento de cadera se ha visto asociado a rotura del labrum y artrosis precoz. El tratamiento de esta patologia puede incluir cirugia. El procedimiento a realizar depende del tipo de pellizcamiento y lesiones asociadas. Los distintos procedimiento quirurgicos han sido reportados por via abierta. Al igual que en otras articulaciones, la via artroscopica presenta ventajas relativas haciendola una opcion atractiva por su menor indice de complicaciones. Una de las limitantes de la artroscopia es la dificultad tecnica que esta plantea. Nuestro grupo ha realizado 60 artroscopias de cadera para el tratamiento del pellizcamiento femoroacetabular con la tecnica aqui descrita. Se han obtenido buenos a excelentes resultados en 91,6 por ciento de los casos (55/60), en un seguimiento a corto plazo. A pesar de las dificultades tecnicas y complicaciones inherentes al procedimiento, la via artroscopica se presenta como una buena alternativa de tratamiento de los pellizcamientos femoroacetabulares pudiendo hacerse desinsercion del labrum, acetabuloplastia, re-insercion y bumpectomia cuando es necesario.

Tratamiento artroscopico del pellizcamiento femoroacetabular: tecnica quirurgica y resultados preliminares / Arthroscopic treatment of femoroacetabular impingement: surgical technique and early results

La articulacion de la cadera puede ser origen de dolor y limitacion funcional. Entre otros diagnosticos se encuentra el pellizcamiento femoroacetabular. El diagnostico de pellizcamiento de cadera se ha visto asociado a rotura del labrum y artrosis precoz. El tratamiento de esta patologia puede incluir cirugia. El procedimiento a realizar depende del tipo de pellizcamiento y lesiones asociadas. Los distintos procedimiento quirurgicos han sido reportados por via abierta. Al igual que en otras articulaciones, la via artroscopica presenta ventajas relativas haciendola una opcion atractiva por su menor indice de complicaciones. Una de las limitantes de la artroscopia es la dificultad tecnica que esta plantea. Nuestro grupo ha realizado 60 artroscopias de cadera para el tratamiento del pellizcamiento femoroacetabular con la tecnica aqui descrita. Se han obtenido buenos a excelentes resultados en 91,6 por ciento de los casos (55/60), en un seguimiento a corto plazo. A pesar de las dificultades tecnicas y complicaciones inherentes al procedimiento, la via artroscopica se presenta como una buena alternativa de tratamiento de los pellizcamientos femoroacetabulares pudiendo hacerse desinsercion del labrum, acetabuloplastia, re-insercion y bumpectomia cuando es necesario

Tratamiento artroscopico del pellizcamiento femoroacetabular: tecnica quirurgica y resultados preliminares / Arthroscopic treatment of femoroacetabular impingement: surgical technique and early results

La articulacion de la cadera puede ser origen de dolor y limitacion funcional. Entre otros diagnosticos se encuentra el pellizcamiento femoroacetabular. El diagnostico de pellizcamiento de cadera se ha visto asociado a rotura del labrum y artrosis precoz. El tratamiento de esta patologia puede incluir cirugia. El procedimiento a realizar depende del tipo de pellizcamiento y lesiones asociadas. Los distintos procedimiento quirurgicos han sido reportados por via abierta. Al igual que en otras articulaciones, la via artroscopica presenta ventajas relativas haciendola una opcion atractiva por su menor indice de complicaciones. Una de las limitantes de la artroscopia es la dificultad tecnica que esta plantea. Nuestro grupo ha realizado 60 artroscopias de cadera para el tratamiento del pellizcamiento femoroacetabular con la tecnica aqui descrita. Se han obtenido buenos a excelentes resultados en 91,6 por ciento de los casos (55/60), en un seguimiento a corto plazo. A pesar de las dificultades tecnicas y complicaciones inherentes al procedimiento, la via artroscopica se presenta como una buena alternativa de tratamiento de los pellizcamientos femoroacetabulares pudiendo hacerse desinsercion del labrum, acetabuloplastia, re-insercion y bumpectomia cuando es necesario.(AU)