Straight antegrade humeral nailing and risk of iatrogenic injury of supraspinatus tendon footprint: An MRI study.

Background: Straight antegrade humeral nailing (SAHN) is associated with excellent clinical results in proximal humerus fractures. The optimal entry point is the top of the humeral head. However, the anatomy is variable, and the entry point can affect supraspinatus tendon footprint (SSP-F) or fracture reduction. The aim of this study was to analyze the relationship between the SSP-F and SAHN entry point by analyzing magnetic resonance imaging (MRI) studies of the humerus. Methods: In total 58 MRI studies of entire humerus were reviewed. The mean age was 51.6 ± 12.4 years, with 40 female patients. The distance between the SSP-F and the SAHN insertion point (critical distance: CD), the width of the footprint, and the neck-shaft angle (NSA) were measured. Univariate and multivariate analysis were performed. Results: The mean CD was 7.51 mm ± 2.81 (0-12.9 mm) with 51.7% of proximal humerus "critical type" (CD <8 mm). The CD was found to be lower in females, with no difference found with varying age (62.5% "critical type"). CD correlated with NSA (linear regression). "Critical type" correlated with female gender and NSA (logistic regression). Discussion: More than half of the humerus are "critical types" as to SAHN and may, therefore, be at risk for procedure-related complications.

Intraoperative immediate strength recovery following lacertus fibrosus release in patients with proximal median nerve compression at the elbow.

PURPOSE: In the literature, we find that patients with lacertus syndrome (LS), proximal median nerve compression at the elbow, present subjective improvement of thumb, and index flexion strength after lacertus fibrosus (LF) release. The aim of this study is to objectively evaluate the immediate change in intraoperative flexion strength after LF release. METHOD: We retrospectively reviewed prospectively collected data of a cohort of 24 patients with a double crush syndrome of the median nerve with no response to conservative treatment. All patients had surgery with LF and carpal tunnel release (CTR) under wide-awake local anaesthesia and no tourniquet (WALANT) and were evaluated intraoperatively with a dynamometer immediately before and after LF release. Flexor digitorum profundus of the second finger (FDP2) and Flexor pollicis longus (FPL) were tested in peak strength to failure. The primary outcome was the percentage of change in strength before and after the release in both assessed muscles. CTR was done after evaluating the change in flexor strength. RESULTS: A percentage of 79.2 women with an average age of 43.3 years. The average strength of FDP2 before LF release was 15.5 pounds (lbs.) (7.0 kg) (SD, 7.2 lbs (3.3 kg)) and 27.1 lbs. (12.2 kg) (SD, 7.1 lbs. (3.2 kg)) after LF release, which corresponds to a 96% (SD, 70%) change in strength (p=0.000). For FPL, the average pre-release strength was 17.7 lbs. (8.0kg) (SD, 4.8 lbs. (2.2 kg)) and 27.4 lbs. (12.4 kg) (SD, 5.2 lbs. (2.4 kg)) post-release, this corresponded to a 65% (SD, 38%) change in strength (p=0.000). CONCLUSIONS: Peak strength to failure in FDP2 and FPL has an immediate significant recovery after LF surgical release in patients with Lacertus syndrome. LEVEL OF EVIDENCE: IV, retrospective study.

The Reverse Shoulder Arthroplasty Angle in MRI: Impact of the Articular Cartilage in the Estimated Inclination of the Inferior Glenoid.

Purpose: To describe the reverse shoulder arthroplasty angle (RSA angle) in magnetic resonance imaging (MRI) and compare the angle formed using bony landmarks (Bony RSA angle or B-RSA angle) with another angle formed using the cartilage margin as reference (Cartilage RSA angle or C-RSA angle). Methods: Adult patients with a shoulder MRI obtained in our hospital between July 2020 and July 2021 were included. The C-RSA angle and B-RSA angle were measured. All images were independently assessed by 4 evaluators. Intraclass correlation coefficient (ICC) was determined for the B-RSA and C-RSA to evaluate interobserver agreement. Results: A total of 61 patients were included with a median age of 59 years (17-77). C-RSA angle was significantly higher than B-RSA (25.4° ± 0.7 vs 19.5° ± 0.7, respectively) with a P-value <.001. The overall agreement was considered "good" for C-RSA (ICC = 0.74 [95% CI 0.61-0.83]) and "excellent" for B-RSA angle (ICC = 0.76 [95% CI 0.65-0.85]). Conclusions: C-RSA angle is significantly higher than B-RSA angle. In cases without significant glenoid wear neglecting to account for the remaining articular cartilage at the inferior glenoid margin may result in superior inclination of standard surgical guides.

The Reliability of Acromioclavicular Joint Dislocation Classification Systems: A Comparison Between the Rockwood and Kraus Classifications.

Background: The Rockwood system for the classification of acute acromioclavicular (AC) joint dislocations has been associated with a lack of reliability. A novel system has been proposed (Kraus classification) that is based on dynamic posterior translation of these injuries. Purpose: To assess the interobserver and intraobserver reliability of the Rockwood and Kraus classification systems and also to examine the impact of surgeon experience on the assessments. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Included were 45 patients with acute AC joint injuries who underwent a radiographic examination using standard bilateral AP and modified Alexander views. For interobserver reliability, 6 shoulder surgeons (expert group) and 6 orthopaedic residents (novice group) reviewed the radiographs to classify injuries according to the Rockwood and Kraus classifications; for each categorization, the participants chose between nonoperative management and surgical treatment. The evaluation was repeated 6 weeks later to determine intraobserver reliability. Kappa (κ) coefficients and their 95% CIs were used to compare interobserver and intraobserver reliability for each classification system according to assessor experience. Statistical differences were considered significant when the upper and lower boundaries of the 95% CI did not overlap. Results: The overall interobserver agreement for diagnosis (both novice and expert groups) was moderate (κ = 0.52 [95% CI, 0.51-0.54]) for the Rockwood classification and substantial (κ = 0.62 [95% CI, 0.53-0.65]) for the Kraus classification; however, no significant differences were observed between the κ values. The overall interobserver agreement for treatment selection was substantial when using both the Rockwood (κ = 0.78 [95% CI, 0.72-0.81]) and Kraus (κ = 0.77 [95% CI, 0.66-0.87]) classifications. The overall intraobserver agreement for diagnosis was substantial using both the Rockwood (κ = 0.65 [95% CI, 0.61-0.67]) and Kraus (κ = 0.73 [95% CI, 0.69-0.75]) classifications. There were no significant differences between the novice and expert groups on any of the evaluations. Conclusion: The Kraus system was slightly more reliable than the Rockwood system for classifying AC joint injuries both between assessor groups and overall. The level of surgeon experience had no impact on the evaluations.

Establishing safe zones to avoid nerve injury in the posterior minimally invasive plate osteosynthesis for humerus fractures: a magnetic resonance imaging study.

Background: Safety zones to avoid nerve injury at proximal incision of posterior minimally invasive plate osteosynthesis for humerus fracture have been scarcely studied. The purpose of this study was to describe the location of axillary and radial nerves (RN) in magnetic resonance imaging to establish safety zones. Methods: Fifty-two magnetic resonance imaging studies of the entire humerus were reviewed. The mean age was 50.6 ± 12.1 years, with 37 female patients. The distance of the axillary nerve (AN; distal portion, humeral midpoint) and RN (medial border, midpoint, and lateral border of the humerus) was measured in relation to the posterolateral acromion angle, acromioclavicular axis, and transepicondylar axis. Univariate analysis (Student's t test) and a multivariate analysis (linear regression) were performed. P values < .05 were considered significant. Results: The AN location at the humerus was 54.9 ± 6.4 mm (20.1% humeral length [HL]) in relation to posterolateral acromion angle and 63.2 ± 6.1 mm (23.2% HL) in relation to acromioclavicular axis. The RN location was 100.2 ± 17.1 mm (36.6% HL) at the humerus medial border, 118.0 ± 21.5 mm (43.1% HL) at the humerus midpoint, and 146.0 ± 24.4 mm (53.6% HL) at the humerus lateral border. In relation to transepicondylar axis, it was 175.4 ± 15.6 mm (64.3% HL), 156.0 ± 19.0 mm (57.2% HL), and 127.4 ± 21.2 mm (46.7% HL), respectively. Nerves location was related to HL, independent of gender. Conclusion: The main finding of our study is that the location of the AN and RN in relation to the humerus is related to the HL and can be used to predictably define the safe zones to avoid nerve injury in the proximal incision of posterior minimally invasive plate osteosynthesis for humerus fractures.

Critical shoulder angle and failure of conservative treatment in patients with atraumatic full thickness rotator cuff tears.

BACKGROUND: Atraumatic full thickness rotator cuff tears (AFTRCT) are common lesions whose incidence increases with age. Physical therapy is an effective conservative treatment in these patients with a reported success rate near 85% within 12 weeks of treatment. The critical shoulder angle (CSA) is a radiographic metric that relates the glenoid inclination with the lateral extension of the acromion in the coronal plane. A larger CSA has been associated with higher incidence of AFTRCT and a higher re-tear rate after surgical treatment. However, no study has yet described an association between a larger CSA and failure of conservatory treatment in ARCT. The main objective of this study is to determine whether there is an association between CSA and failure of physical therapy in patients with AFTRCT. METHODS: We reviewed the imaging and clinical records of 48 patients (53 shoulders), 60% female, with a mean age of 63.2 years (95% CI ± 10.4 years); treated for AFTRCT who also underwent a true anteroposterior radiograph of the shoulder within a year of diagnosis of the tear. We recorded demographic (age, sex, type of work), clinical (comorbidities), and imaging data (CSA, size and location of the tear). We divided the patients into two groups according to success or failure of conservative treatment (indication for surgery), so 21 shoulders (39.6%) required surgery and were classified as failure of conservative treatment. Univariate and multivariate analysis was performed to detect predictors of failure of conservative treatment. RESULTS: The median CSA was 35.5º with no differences between those with failure (median 35.5º, range 29º to 48.2º) and success of conservative treatment (median 35.45º, range 30.2º to 40.3º), p = 0.978. The multivariate analysis showed a younger age in patients with failure of conservative treatment (56.14 ± 9.2 vs 67.8 ± 8.4, p < 0.001) and that male gender was also associated with failure of conservative treatment (57% of men required surgery vs 28% of women, p = 0.035). CONCLUSIONS: It is still unclear if CSA does predict failure of conservative treatment. A lower age and male gender both could predicted failure of conservative treatment in AFTRCT. Further research is needed to better address this subject.

Four-Corner Arthrodesis: Comparative Analysis of Open Technique Versus Percutaneous Technique with Arthroscopic Assistance.

Introduction Four-corner arthrodesis is a salvage technique for patients with carpal advanced osteoarthritis. Nowadays, percutaneous techniques with arthroscopic assistance have been described, achieving favorable results with minimally invasive techniques advantages over open surgery. Objective To compare functional and radiological results in patients with SLAC or SNAC wrists operated with open surgical technique versus percutaneous surgery with arthroscopic assistance. Materials and Methods Retrospective case-control study of clinical records and radiological images of patients with carpal advanced osteoarthritis operated with both surgical techniques. We studied demographic variables, pain with visual analog scale (VAS) score, function in ranges of mobility, time of consolidation, and correction of DISI deformity. Results A total of 22 male patients with an average age of 32.5 years were studied. Thirteen patients in the case group (percutaneous technique with arthroscopic assistance) and nine patients in the control group (open surgery). Pain score in VAS at discharge was 3 for cases and 5 in controls ( p = 0.008), and at 30 days postoperatively, it was 0 and 3 respectively ( p = 0.00). The extension and flexion ranges were 52.6°and 38.7° in the cases and 35.7° and 32.4° in the control group ( p = 0.119 and 0.0016, respectively). The capitolunate angle was 10°in the controls and 5°in the cases ( p = 0.0008). The time of consolidation was 8.8 weeks in cases and 12.5 weeks in controls ( p = 0.039). Conclusions The percutaneous technique with arthroscopic assistance for the 4-courner arthrodesis is a reproducible technique and is effective in achieving consolidation, pain reduction and preservation of wrist motion. In the present study, we demonstrate superiority of this technique over the open surgery. Level of Evidence This is a Level III, therapeutic study.

Increasing incidence of rotator cuff surgery: A nationwide registry study in Chile.

BACKGROUND: The rotator cuff surgery (RCS) incidence is rising rapidly in North America, Europe, Asia, and Australia. Despite this, multiple factors limit patients' access to surgery. In Latin America, barriers to orthopedic surgery have been largely ignored. The purpose of this study was to calculate the rate of RCS in Chile between 2008 and 2018, investigating possible associated factors to access such as age, sex, and the health insurance. METHODS: An ecological study was carried out with nationwide data obtained from the Database of Hospital Discharges of the Department of Statistics. All Chilean inhabitants aged 25 years or more were included. We used the ICD-10 codes M751, M754, and S460. The annual incidence rate of surgeries and the incidence rate for the period studied per 100,000 inhabitants were calculated. Data were analyzed stratified by age, sex, year of study, and the health insurance. Negative binomial regression was used to compare rates. Statistical analyzes were performed with Stata v.14 software. RESULTS: 39,366 RCSs were performed, with a total rate for the period of 32.36 per 100,000 inhabitants. The annual rate of surgeries from 2008 to 2018 increased from 24.55 to 49.11 per 100,000/year. When adjusting for year, an annual increase in surgery rates of 8.19% (95% CI 6.7-9.6) and 101% growth between 2008 and 2018 (95% CI 90-109%, p < 0.001) was observed. When comparing the global rates according to the health insurance, the public system corresponds to 21.3 per 100,000 and the private system to 72 per 100,000, the latter being 3.4-times higher (95% CI 2.7-4.4; p < 0.001). CONCLUSION: RCS rates are increasing in Chile concordantly with previous reports of other western countries. The most important factor associated with RCS rate found was the patients' health insurance, with higher rates observed for the private sector.

Mayor presión y área de contacto en reparación transósea cruzada de manguito rotador versus reparación simple / Increased pressure and contact area in rotator cuff crossed versus simple transosseous repair

OBJETIVO: Comparar la presión y el área de contacto en la interfase tendón-huella de una reparación realizada con suturas transóseas simples y cruzadas. MÉTODOS: Se utilizaron doce hombros de cordero para simular una rotura de manguito rotador. Se midió el área de contacto en la interfase tendón-huella con láminas sensibles a presión; luego, se midió la presión con un sensor digital. Se registró la presión basal durante la aplicación de carga cíclica y al final de la intervención. Se compararon 2 reparaciones: 2 túneles transóseos con nudos simples (TOS; n = 6) y 2 túneles transóseos con nudos cruzados (TOC; n = 6), utilizando FiberWire #2. Se realizaron 1.400 ciclos, con una frecuencia 2,5 Hz y una carga de 5 N. Se utilizó la prueba de Mann-Whitney, y ae consideraron significativos valores de p < 0,05. RESULTADOS: La reparación TOS presentó un 50,9 ± 12,7% distribución de presiones en comparación con 72,2 ± 5,3% en la reparación TOC (p < 0,009). La presión promedio en la reparación TOS fue 0,7 ± 0,1 MPa en comparación con 1,1 ± 0,2 MPa en la reparación TOC (p < 0,007). La reparación TOS registró una presión basal de 5,3 ± 5,3 N, presión final de 3,8 ± 4,6 N, y una variación de 51,7 ± 38%. La reparación TOC registró una presión basal de 10,7 ± 1,8 N, presión final de 12,9 ± 8,7 N, y una variación de 114,9 ± 65,9% (p < 0,044; p < 0,022; y p < 0,017, respectivamente). CONCLUSIÓN: La reparación TOC presenta mayor presión a nivel de la interfase tendón-hueso, menor pérdida de fuerza de contacto ante cargas cíclicas, y una mejor distribución de fuerza en la huella al comparar con la reparación TOS, lo que se podría traducir en mejor cicatrización tendínea.

OBJETIVE: To compare the pressure and contact area at the tendon-footprint interface of a repair performed with simple and crossed transosseous sutures. METHODS: Twelve lamb shoulders were used to simulate a rotator cuff tear. The contact area at the tendon-footprint interface was measured with pressure-sensitive films; then, the pressure was measured with a digital sensor. The baseline pressure was recorded during the application of a cyclic load and at the end of the intervention. A total of 2 repairs were compared: 2 transosseous sutures with single knots (STO; n = 6) and 2 transosseous sutures with crossed knots (TOC; n = 6) using FiberWire #2. In total, 1,400 cycles were performed, with a frequency of 2.5 Hz and a load of 5 N. The Mann-Whitney test was used. Values of p < 0.05 were considered significant.RESULTS: The TOS repair presented 50.9 ± 12.7% of pressure distribution compared to 72.2 ± 5.3% in the TOC repair (p < 0.009). The mean pressure in the TOS repair was of 0.7 ± 0.1 MPa compared to 1.1 ± 0.2 MPa in the TOC repair (p < 0.007). The TOS repair registered a basal pressure of 5.3 ± 5.3 N, a final pressure of 3.8 ± 4.6 N, and a variation of 51.7 ± 38%. The TOC repair registered a basal pressure of 10.7 ± 1.8 N, a final pressure of 12.9 ± 8.7 N, and a variation of 114.9 ± 65.9% (p < 0.044; p < 0.022; and p < 0.017 respectively).CONCLUSION: The TOC repair presents higher pressure at the tendon-bone interface, less loss of contact force under cyclic loads, and a better distribution of force on the footprint when compared with the TOS repair, which could translate into better tendon healing.

Abrasión intraósea por sutura según el ángulo del túnel transóseo en huella del manguito rotador / Intraosseous suture abrasion according to the angle of the transosseous tunnel in rotator cuff footprint

OBJETIVO: Comparar el desgaste óseo generado por la abrasión de una carga cíclica entre túneles clásicos oblicuos y perpendiculares. Nuestra hipótesis es la de que el túnel oblicuo presenta un menor desgaste óseo por abrasión cíclica comparado con el túnel perpendicular. MÉTODOS: Ocho hombros congelados de cordero fueron usados para el estudio biomecánico. En cada húmero proximal, dos túneles (oblicuo y perpendicular) fueron generados en la tuberosidad mayor. Se utilizó un sistema de tracción cíclica para traccionar hacia atrás y adelante una sutura trenzada en tensión a través del túnel, midiendo la distancia entre la entrada y la salida de la sutura en el túnel antes y después del proceso de ciclado como medida de perdida de tensión de la sutura. El resultado principal es el cambio de la distancia entre la entrada y la salida de la sutura en el túnel después del ciclado para estimar el desgaste óseo dentro del túnel. Para el análisis estadístico, se utilizó la prueba U de Mann-Whitney. Se consideraron significativos valores de p < 0,05. RESULTADOS: Los túneles perpendiculares tuvieron un 23,24 7,44% de pérdida de longitud, y los túneles oblicuos, 7,76 4,32%. La diferencia de pérdida de longitud fue significativa (p » 0,0003). CONCLUSIÓN: La abrasión ósea generada por el movimiento cíclico de la sutura en el túnel transóseo está influenciada por la geometría del túnel. El desgaste óseo es menor en un túnel oblicuo comparado con un túnel perpendicular. NIVEL DE EVIDENCIA: Estudio de ciencia básica

OBJETIVE: To compare the bone wear generated by the abrasion of a cyclic load between classic oblique and perpendicular tunnels. Our hypothesis is that the oblique tunnel is submitted to less cyclic abrasion bone wear compared with the perpendicular tunnel. METHODS: Eight fresh-frozen lamb shoulders were used for biomechanical testing. In each proximal humerus, two tunnels (one oblique and one perpendicular) were drilled at the greater tuberosity. We used a cyclic traction system to pull back and forth a braided suture under tension through the tunnel, measuring the distance between the entry and exit points of the suture within the tunnel before and after the cyclic process to release the tension in the suture. The main outcome was the percentage of change in the distance between the entry and exit points of the suture within the tunnel before and after cyclic abrasion to estimate the degree of bone wear inside the tunnel. For the statistical analysis, the Mann-Whitney U test was used. Values of p < 0.05 were considered significant. RESULTS: The perpendicular bone tunnels had 23.24 7.44% decrease in length, and the oblique bone tunnels, 7.76 4.32%. The difference in the decrease in length was significant (p » 0.0003). CONCLUSION: The bone abrasion caused by the cyclical movement of the suture in the bone tunnel was influenced by the shape of the tunnel. Bone wear was lower with an oblique tunnel compared with a perpendicular tunnel. LEVEL OF EVIDENCE: Basic Science Study

Presión y área de contacto en reparación de manguito rotador: una revisión sistemática / Pressure and contact area in rotator cuff repair: a systematic review

OBJETIVO Proporcionar una sinopsis exhaustiva y un análisis de los estudios biomecánicos sobre la magnitud y distribución de la presión en la interfase tendón-huella de las roturas del manguito rotador, informadas en la literatura en los últimos cinco años. MÉTODOS La investigación se realizó de acuerdo con los métodos descritos en el Manual Cochrane. Los resultados se informan de acuerdo con el consenso de Ítems Preferidos de Reporte en Revisiones Sistemáticas y Metaanálisis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA, en inglés). La búsqueda se realizó el 1er de junio de 2020. Se identificaron e incluyeron estudios ex vivo de ciencia básica y estudios biomecánicos publicados, que evaluaran la magnitud y distribución de la presión en la interfase tendón-huella de las roturas del manguito rotador reparadas entre enero de 2015 y junio de 2020. Se realizaron búsquedas sistemáticas en las bases de datos MEDLINE, Embase, Scopus y Google Scholar utilizando los términos y operadores booleanos: (Rotator Cuff OR Supraspinatus OR Infraspinatus OR Subscapularis OR Teres Minor) AND Pressure AND Footprint. En la base de datos Embase, respetando su sintaxis, se utilizó: Rotator Cuff AND Pressure AND Footprint. RESULTADOS Un total de 15 de los 87 artículos encontrados cumplieron con todos los criterios de elegibilidad y se incluyeron en el análisis. CONCLUSIÓN La presión y área de contacto sería optimizada biomecánicamente con una reparación transósea de doble fila equivalente, sin nudos en la hilera medial, y con el uso de cintas para su ejecución, conceptos de reparación específica para roturas delaminadas, y limitación de la abducción en el postoperatorio inmediato.

OBJETIVE To provide a comprehensive synopsis and analysis of biomechanical studies on the magnitude and distribution of pressure at the tendon-footprint interface of rotator cuff tears reported in the literature in the last five years. METHODS The research was performed according to the methods described in the Cochrane Manual. The results are reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) consensus. The search was performed on June 1st, 2020. We identified and included ex vivo basic science studies and published biomechanical studies that evaluated the magnitude and distribution of pressure at the tendon-footprint interface of rotator cuff tears repaired between January 2015 and June 2020. Systematic searches on the MEDLINE, Embase, Scopus and Google Scholar databases were performed using the terms and Boolean operators: (Rotator Cuff OR Supraspinatus OR Infraspinatus OR Subscapularis OR Teres Minor) AND Pressure AND Footprint. In the Embase database, respecting its syntax, the following was used: Rotator Cuff AND Pressure AND Footprint. RESULTS In total, 15 of the 87 articles found fulfilled all the eligibility criteria and were included in the analysis. CONCLUSION The pressure and contact area would be biomechanically optimized with an equivalent transosseous double-row repair, without knots in the medial row, and with the use of tapes for its execution, specific repair concepts for delaminated tears, and a limitation of abduction in the immediate postoperative period.

Artrodesis de cuatro esquinas: análisis comparativo de técnica abierta versus técnica percutánea con asistencia artroscópica / Four-corner arthrodesis: comparative analysis of open surgery versus percutaneous technique with arthroscopic assistance

INTRODUCCIÓN: La artrodesis de cuatro esquinas es una técnica de salvataje para los pacientes con artrosis avanzada del carpo. Los objetivos quirúrgicos son disminuir el dolor y mantener cierto movimiento de la muñeca. En el último tiempo, se han descrito técnicas percutáneas con asistencia artroscópica que han logrado resultados favorables, a pesar de que la técnica abierta sigue siendo el gold estándar para realizar esa técnica quirúrgica. OBJETIVO: Comparar resultados funcionales y radiológicos en pacientes con muñecas con colapso avanzado escafolunar (scapholunate advanced collapse, SLAC) o colapso avanzado en la pseudoartrosis del escafoides (scaphoid nonunion advanced collapse, SNAC) operados con técnica quirúrgica abierta versus técnica percutánea con asistencia artroscópica. MATERIALES Y MÉTODOS: Estudio retrospectivo tipo caso-control, de fichas clínicas e imagenología de pacientes con artrosis avanzada del carpo operados con técnica percutánea y asistencia artroscópica y cirugía abierta. Se estudian variables demográficas, dolor mediante la Escala Visual Analógica (EVA), función en rangos de movilidad, tiempo de consolidación, y corrección del ángulo capitolunar. Se describe la técnica quirúrgica de la cirugía abierta y la cirugía percutánea con asistencia artroscópica. RESULTADOS: Se estudiaron 22 pacientes del sexo masculino con edad promedio de 32,5 años. Había 13 pacientes en el grupo de casos (técnica percutánea con asistencia artroscópica) y 9 pacientes en el grupo de controles (técnica abierta). El dolor en la EVA al momento del egreso hospitalario fue de 3 para los casos y de 5 para los controles (p » 0,008), y a los 30 días del postoperatorio, fue de 0 y 3 respectivamente (p » 0,00). Los rangos de extensión y flexión fueron de 52,6° y 38,7° para los casos y de 35,7° y 32,4° para los controles (p » 0,1119 y 0,0016, respectivamente). El ángulo capitolunar fue de 10° para los controles y de 5° para los casos (p » 0,0008). El tiempo de consolidación fue de 8,8 semanas para los casos y de 12,5 semanas para los controles (p » 0,039). DISCUSIÓN: Tanto la técnica percutánea con asistencia artroscópica cuanto la cirugía abierta para realizar una artrodesis de cuatro esquinas son técnicas reproducibles y efectivas en lograr consolidación, disminución del dolor, y mantenimiento de rangos de movimiento en la muñeca. CONCLUSIÓN: En el presente trabajo se demuestran mejores promedios de los parámetros evaluados con la técnica percutánea que con la cirugía abierta; sin embargo, es necesario realizar estudios prospectivos para realizar una recomendación con respecto a la técnica quirúrgica de elección.

INTRODUCTION: Four-corner arthrodesis is a salvage technique for patients with advanced carpal osteoarthritis. This procedure aims to reduce pain and preserve wrist motion. Even though percutaneous techniques with arthroscopic assistance reportedly have favorable outcomes and the advantages of minimal invasiveness, open surgery remains the gold standard for four-corner arthrodesis. OBJECTIVE: The present study aims to compare the functional and radiological outcomes of patients with scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC) submitted to open surgery versus percutaneous surgery with arthroscopic assistance. MATERIALS AND METHODS: Retrospective case-control study of clinical records and radiological images of patients with advanced carpal osteoarthritis submitted to percutaneous surgery with arthroscopic assistance versus open surgery. Demographic variables, pain score using the visual analog scale (VAS), function ranges of motion, time until consolidation, and correction of the capitolunate angle were analyzed. Both techniques are described. RESULTS: In total, 22 male patients with an average age of 32.5 years were studied, including 13 patients from the case group (percutaneous surgery with arthroscopic assistance) and 9 patients from the control group (open surgery). The VAS score for pain at discharge was of 3 for the cases and of 5 for the controls (p » 0.008); 30 days postoperatively, it was of 0 and 3 respectively (p » 0.00). The ranges of extension and flexion were of 52.6° and 38.7° for the case group, and of 35.7° and 32.4° for the control group (p » 0.119 and 0.0016 respectively). The capitolunate angle was of 10° for the controls and of 5° for the cases (p » 0.0008). The time until consolidation was of 8.8 weeks for the cases and of 12.5 weeks for the controls (p » 0.039). DISCUSSION: Both four-corner arthrodesis techniques are reproducible and effective in achieving consolidation, pain reduction and preservation of wrist motion. CONCLUSION: The present study demonstrates the superiority of the percutaneous technique with arthroscopic assistance over open surgery. Further prospective studies are required for an adequate recommendation.

Treatment of olecranon fractures using an intramedullary cancellous screw and suture tension band: minimum 2-year follow-up.

Background: Tension band wiring and plates are the most widely used treatments for transverse displaced fractures of olecranon despite high rates of hardware complications, subsequent implant removal, and associated costs. The purpose of this study was to report the outcomes of displaced transverse olecranon fractures treated with intramedullary screw and suture tension band. Methods: We performed an observational, retrospective, consecutive, monocentric, continuous multioperator study. We reviewed 31 Mayo type IIA displaced olecranon fractures treated in our institution with intramedullary 6.5 mm AO cancellous screw and high-strength suture tension band (No. 2 FiberWire®) from 2016 to 2018. Inclusion was limited to functionally independent patients with Mayo type IIA fractures and minimum 24-month follow-up for implant removal. We assessed clinical outcomes including range of motion; QuickDASH score; and Mayo Elbow Performance Score. Categorical data were analyzed with Fisher's exact test when appropriate. Continuous data were analyzed with the Student t-test or Mann-Whitney U test after assessment for normality. Statistical analysis was performed with STATA 16 software. Results: Twenty-seven patients with a mean follow-up period of 38.4 ± 6.2 months (range, 24.1-50 months) were included in the study. The average flexion was 134.5° ± 14.8° (range, 70°-140°) and the mean extension was -5.9° ± 7.0° (range, -20°-0°). Mean pronation and supination were 85.8° ± 11.9° (range, 45°-90°) and 86.9° ± 14.3° (range, 20°-90°), respectively. The mean Mayo Elbow Performance Score was 90.8 ± 9.6 (range, 70-100) with 92.3% good and excellent results. The mean QuickDASH score was 17.1 ± 16 (range, 0-54.5). There were 3 hardware-related removals (11.1%). The overall removal rate was 18.5%. Univariate analysis of the factors associated with implant removal were pain in relation to the implant (60% vs. 11%, P = 0.0482), proximal screw migration (3.7 mm vs. 1.7 mm, P = 0.05), articular angle (22.5° vs. 27.7°, P = 0.0353), and olecranon width (22.2 mm vs. 24.4 mm, P = 0.0166). In total, 26.1% of the cases presented some degree of proximal migration of the implant (2.7 ± 1.8 mm of migration; range, 1.5-6.2 mm). Univariate analysis of the factors associated with implant proximal migration were proximal ulnar dorsal angulation (1.7° vs. 6.4°, P = 0.0179), anteroposterior endomedullary canal (7.3 mm vs. 6.0 mm, P = 0.0369), and lateral endomedullary canal (7.2 mm vs. 5.0 mm, P = 0.0219). Conclusion: The functional outcomes of simple transverse olecranon fractures treated with an intramedullary cancellous screw and a suture tension band are excellent, associated with a low rate of complications and material removal.

Distal clavicle fractures with "superior intact cortical bone": minimally invasive surgery.

Introduction: Distal clavicle fractures represent 12%-26% of all clavicle fractures. For unstable cases, surgical fixation is the preferred method of treatment. To date, there is still controversy regarding the best fixation method with a high reoperation and complication rate reported. The purpose of this article is to describe a minimally invasive method for reduction and stabilization of displaced distal clavicle fractures, using cortical buttons. Surgical technique: After standard preoperative preparation, a 3-cm incision is made at the coracoclavicular area. Using both coracoid and clavicle tunnels, fracture reduction and fixation is obtained using a cortical fixation button. Standard postoperative care is given. Results: A total of 21 patients (19 men) with a mean age of 34.7 years were treated using this technique. The follow-up was between 6 and 41 months, with an average of 23.4 months. The mean simple shoulder test score was 79.4 (range 66-91.7), and the QuickDASH score was 11 (range 6.8-15.9). Consolidation of the fracture was confirmed at the 12-week follow-up radiography, with no cases of nonunion or malunion identified. No patients presented infection or complications at the surgical site. Implant removal was not needed in this series. All the patients returned to work. Conclusion: Minimally invasive button fixation of unstable distal clavicle fractures is a safe and reliable alternative treatment. The initial outcome report is promising with excellent clinical and radiological results and no complications or implant removals.

Criterios radiográficos para la reducción rotatoria en fracturas diafisarias de húmero / Radiological criteria for rotational reduction in humeral shaft fractures

Introducción: La fractura diafisaria de húmero es frecuente y, en la actualidad, se privilegia el tratamiento quirúrgico. La consolidación en mala rotación puede causar un deterioro de la función y artrosis a largo plazo. Con las técnicas mínimamente invasivas, es difícil manejar la rotación intraoperatoria al no tener una visión directa de la reducción fracturaria. Objetivo: Describir criterios radiográficos para la reducción rotatoria en las fracturas diafisarias de húmero. Materiales y métodos: Estudio retrospectivo de radiografías de húmero comparando criterios radiográficos del húmero distal entre radiografías con rotación interna (sin retroversión proximal) y rotación externa (con retroversión fisiológica). Criterios estudiados: sobreproyección del epicóndilo lateral por sobre el capitellum >50%, esclerosis del borde inferior de la fosa olecraneana, esclerosis del borde lateral de la fosa olecraneana y asimetría de la fosa olecraneana. Resultados: El 97% de las 200 radiografías estudiadas cumplió con los criterios de inclusión y exclusión. Sobreproyección del epicóndilo por sobre el capitellum: 83,3% de los casos; esclerosis del borde inferior de la fosa olecraneana: 30%, esclerosis del borde lateral de la fosa olecraneana: 86,6% y asimetría: 80% de ellas. Todos los criterios con significancia estadística (p <0,001). Al analizar los tres signos positivos en conjunto, la sensibilidad fue del 70% y la especificidad, del 98%; valor predictivo positivo 95,5% y valor predictivo negativo 84,5%. Conclusiones: La rotación humeral correcta es difícil de reproducir en las cirugías mínimamente invasivas, en pacientes con una fractura diafisaria. Describimos cuatro criterios radiográficos que permiten inferir una correcta rotación humeral. Nivel de Evidencia: III

Introduction: Humeral shaft fractures are frequent and surgical treatment is currently favored. Consolidation in malrotation is a complication that can lead to impaired function and long-term osteoarthritis. In minimally invasive techniques, it is difficult to manage intraoperative rotation as there is no direct view of the fracture reduction. Objective: To describe radiological criteria for rotational reduction in humeral shaft fractures. Materials and methods: Retrospective study of humerus radiographs comparing radiological criteria of the distal humerus between radiographs with internal rotation (without proximal retroversion) and radiographs with external rotation (with physiological retroversion). Criteria studied: Overprojection of the lateral epicondyle over the capitellum of more than 50%; sclerosis of the lower border of the olecranon fossa (OF); sclerosis of the lateral border of the OF and asymmetry of the OF. Results: 200 radiographs were studied; 97% met the inclusion and exclusion criteria. Overprojection of the epicondyle over the capitellum was found in 83.3% of the cases. Sclerosis of the inferior border of the OF in 30%, sclerosis of the lateral border of the OF in 86.6%, and asymmetry of OF in 80%. All criteria with statistically significant (p<0.001). When analyzing the 3 positive signs, we found a sensitivity of 70% and a specificity of 98%. The positive predictive value was 95.5% and the negative predictive value was 84.5%. Conclusions: Correct humeral rotation is difficult to reproduce when performing minimally invasive surgeries in patients with a diaphyseal fracture. We describe 4 radiological criteria that allow inferring a correct humeral rotation. Level of Evidence: III

Glenoid size and orientation in the Chilean population / Tamaño y orientación glenoidea en la población chilena

Glenoid morphology is a key factor in determining the success of shoulder surgery. The purpose of this experimental study was to precisely determine the anatomical size and orientation of the glenoid in the Chilean population. 122 CT scans from asymptomatic Chilean patients were obtained. The mean age was 43.8 years (SD 12.3; range, 17-53 years) with 63 female and 59 male patients. For each of the scapulae, were obtained the glenoid version and inclination, maximum glenoid width and height, superior glenoid width, glenoid surface area, glenoid vault depth, and maximum scapular width. The glenoid size showed an average width of 26 ± 2.7 mm, a height of 40.3 ± 3.5 mm and a vault depth of 26.5 ± 3.7 mm. There were significant differences between men and women. The glenoid orientation showed an average of -13.9 ± 4.8° of retroversion and a superior inclination of 11.1 ± 4.7°. Significant differences between men and women were seen only for version. We conclude, that in this Chilean sample the morphological parameters of the glenoid correspond to the published literature, however, some characteristics in this cohort must be further confirmed using other methods.

La morfología glenoidea es un factor clave para determinar el éxito de la cirugía de hombro. El propósito de este estudio experimental fue determinar con precisión el tamaño anatómico y la orientación de la glenoides en la población chilena. Se obtuvieron 122 tomografías computarizadas de pacientes chilenos asintomáticos. La edad media fue de 43,8 años (DE 12,3; rango, 17-53 años) con 63 pacientes femeninos y 59 masculinos. Para cada una de las escápulas, se obtuvieron la versión glenoidea y la inclinación, el ancho y la altura glenoidea máxima, el ancho glenoideo superior, el área de superficie glenoidea, la profundidad de la bóveda glenoidea y el ancho escapular máximo. El tamaño glenoideo mostró un ancho promedio de 26 ± 2,7 mm, una altura de 40,3 ± 3,5 mm y una profundidad de bóveda de 26,5 ± 3,7 mm. Hubo diferencias significativas entre hombres y mujeres. La orientación glenoidea mostró un promedio de -13,9 ± 4,8 ° de retroversión y una inclinación superior de 11,1 ± 4,7 °. Se observaron diferencias significativas entre hombres y mujeres solo para la versión. Concluimos que en esta muestra chilena los parámetros morfológicos de la glenoides corresponden a la literatura publicada, sin embargo, algunas características de esta cohorte deben confirmarse aún más utilizando otros métodos.