Limites da artroscopia na instabilidade anterior do ombro

ResumoMuito se discute sobre os limites do tratamento da instabilidade anterior do ombro por artroscopia. O avanço no entendimento das repercussões biomecânicas das lesões bipolares sobre a estabilidade do ombro, bem como na identificação de fatores relacionados ao maior risco de recidiva têm nos ajudado a definir, de forma mais apurada, os limites do reparo por via artroscópica.Ressaltamos a importância de diferenciação entre perda óssea por erosão da glenoide (POAG) e fraturas da borda da glenoide, pois o prognóstico do tratamento diverge entre essas formas de falha óssea da glenoide. Neste contexto, entendemos que há três tipos de falha óssea: a) Bankart ósseo (fratura); b) combinada; e c) POAG, e abordaremos as opções de tratamento sugerido em cada situação.Até há pouco tempo, a escolha do método cirúrgico era norteada basicamente pelo grau de acometimento ósseo. Com a evolução do conhecimento, da biomecânica das lesões bipolares e do conceito do glenoid track (trilho da glenoide), o ponto de corte da lesão crítica, vem sendo alterado com tendência de queda. Além das falhas ou perdas ósseas, outras variáveis foram adicionadas e tornaram a decisão mais complexa, porém um pouco mais objetiva.O presente artigo de atualização tem como objetivo fazer uma breve revisão da anatomia com as principais lesões encontradas na instabilidade; abordar detalhes importantes na técnica cirúrgica artroscópica, em especial nos casos complexos, e trazer as evidências atuais sobre os assuntos de maior divergência, buscando guiar o cirurgião na tomada de decisão.

ARTHROSCOPIC BANKART REPAIR FOR ADOLESCENT UNIDIRECTIONAL SHOULDER INSTABILITY: CLINICAL AND RADIOGRAPHIC PREDICTORS OF REVISION SURGERY AND INSTABILITY

INTRODUCTION: The treatment of adolescent shoulder instability can be a challenging problem, with multiple patient and radiographic risk factors for recurrent instability. Although glenoid bone loss has been well described, humeral bone loss has gained more recent attention. The purpose of this study is to evaluate the incidence and clinical outcomes of “off track” shoulder lesions and their association with clinical outcomes. METHODS: A retrospective IRB approved study was performed to identify patients less than 19 years of age treated with isolated arthroscopic anterior labral repair for unidirectional shoulder instability. Radiographic measurements of glenoid diameter, % glenoid bone loss, glenoid track, hill-sachs interval (HIS), HS/glenoid track ratio, and intact anterior articular angle (IAAA) were performed for all patients with magnetic resonance imaging (MRI). All patients were contacted at final follow-up to collect outcome scores (PASS and SANE scores, activity level). A multivariable logistic regression analysis was performed to identify predictors of revision surgery or subjective instability (RI). RESULTS: 86 patients were identified to meet inclusion criteria and 69 of these patients, 53 males and 16 females with a median age of 16 years [15, 17], had minimum 1-year clinical follow-up and were included in assessment of clinical outcomes and multivariable analysis. 12 patients (17%) had revision surgery and 10 patients had subjective instability without revision (14%) In univariate analysis (Table 1), patient height was the only patient factor which was significantly different between the revision/instability (RI) cohort and the non-revision/instability (NRI) cohort. All 86 patients were included in radiographic analysis. Intra- and inter-rater reliability (ICCs) for radiographic measurements are presented in table 2. Agreement was good and excellent for all measurements with the exception of inter-rater reliability of IAAA. Multivariable regression analysis demonstrated that HS/glenoid track ratio was not a predictor for RI. PASS and SANE scores at final follow-up were significantly lower in the RI cohort (79.5 and 70) respectively) as compared to the NRI cohort (94 and 90 respectively), p<0.001. 42 patients (69%) returned to the same or higher level of sports following surgery and this was no different between RI and NRI cohorts. CONCLUSIONS: 31% of adolescent patients in our cohort experienced RI following arthroscopic bankart repair and this was associated with inferior PASS and SANE scores. Off-track lesions were not predictive of failure with primary repair.

Imaging Modalities for the Glenoid Track in Recurrent Shoulder Instability: A Systematic Review

Background: The glenoid track (GT) concept illustrates how the degree of glenoid bone loss and humeral bone loss in the glenohumeral joint can guide further treatment in a patient with anterior instability. The importance of determining which lesions are at risk for recurrent instability involves imaging of the glenohumeral joint, but no studies have determined which type of imaging is the most appropriate. Purpose/Hypothesis: The purpose of this study was to determine the validity and accuracy of different imaging modalities for measuring the GT in shoulders with recurrent anterior instability. We hypothesized that 3-dimensional computed tomography (3D-CT) would be the most accurate imaging technique. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using PubMed, Scopus, Medline, and Cochrane libraries between database inception and July 2019. We included all clinical trials or cadaveric studies that evaluated imaging modalities for assessing the GT. Results: A total of 13 studies were included in this review: 1 study using 2-dimensional CT, 6 studies using 3D-CT, 4 studies using magnetic resonance imaging (MRI), 1 study using magnetic resonance arthrography (MRA)/MRI, and 1 study combining CT and MRI. The mean sensitivity, specificity, and accuracy for 2D-CT was 92%, 100%, and 96%, respectively. For MRI, the means were 72.2%, 87.9%, and 84.2%, respectively. No papers included 3D-CT metrics. The mean intraclass correlation coefficients (ICCs) for intraobserver reliability were 0.9046 for 3D-CT and 0.867 for MRI. ICCs for interobserver reliability were 0.8164, 0.8845, and 0.43 for 3D-CT, MRI, and MRA/MRI, respectively. Conclusion: There is evidence to support the use of both CT and MRI imaging modalities in assessing the GT. In addition, few studies have compared radiographic measurements with a gold standard, and even fewer have looked at the GT concept as a predictor of outcomes. Thus, future studies are needed to further evaluate which imaging modality is the most accurate to assess the GT.

The role of Hill-Sachs localization on the failure of arthroscopic shoulder stabilization. The results of a prospective cohort study

Objectives: Recurrent glenohumeral instability is frequently associated with glenoid and humeral bone loss. It is predictive of capsulolabral repair failure. However, the best way to quantify these shortcomings remains controversial. The aim of our study is to determine the best predictor of recurrent instability after arthroscopic shoulder stabilization. Methods: Over the past 10 years, all the patients recruited for shoulder stabilization surgery in 4 academic centers have been included in the prospective cohort called "LUXE". The ISIS score is used to stratify patients for surgery (Bankart, Bankart + Remplissage, Latarjet). Only patients with a preoperative CT scan with 3D reconstruction and clinical follow-up ≥1 year were included. Of a total of 262 patients included in the “LUXE” cohort, 103 met the inclusion criteria. The majority of patients were male (79%) with an average age of 28 years. The median number of dislocations before stabilization surgery was six. Bone deficits were measured on the 3D reconstructions using the Glenoid Clock and Ratio, the Humeral Clock and Ratio and the Glenoid Track methods and the angle of engagement of the Hill-Sachs lesion in the axial plane. Results: Seventy patients had arthroscopic stabilization and 33 a Latarjet procedure. The ISIS scores for the two groups were 2.7 and 4.8 (p<0.001) respectively. The average glenoid bone loss was 9+/-10% (0-37%), humeral bone loss was 15+/-6% (0-36%) and the angle of engagement of the Hill-Sachs lesion was 71+/-30° in external rotation. Fifty-three patients (51%) had an off-track lesion. Eighteen patients had recurrent instability after arthroscopic stabilization (23%) versus only 2 patients (6%) for Latarjets (OR= 4.6, p=0.034). Preoperative bone loss was not related to failure after a Latarjet procedure. The risk factors identified after arthroscopic stabilization were a lower engaging Hill-Sachs angle in external rotation (65° vs. 72°; p=0.05), less humeral bone loss (humeral clock of 42° vs. 58°; p=0.034) and an extended follow-up time (p=0.006). Glenoid bone loss, or the combined measurement (glenoid track) was not predictive of failure. Conclusion: Despite a lower ISIS score, arthroscopic management with Bankart +/- Remplissage is correlated with a significantly higher recurrence rate compared to the Latarjet procedure. Failure was related to humeral bone loss and to the morphology/orientation of the Hill-Sachs lesion rather than the volume of bone loss.

Current concepts in anterior glenohumeral instability: diagnosis and treatment

The glenohumeral joint is the most dislocated articulation, accounting for more than 50% of all joint dislocations. The reason behind shoulder instability should be investigated in detail for successful management, and the treatment plan should be individualized for all patients. Several classification systems have been proposed for glenohumeral instability. A physical exam is mandatory no matter what classification system is used. When treating patients with anterior shoulder instability, surgeons need to be aware of the critical size of the bone loss, which is commonly seen. The glenoid track concept was clinically adopted, and the measurement of the glenoid track for surgical decision-making is recommended. Detailed assessment of existing soft tissue injury to the labrum, capsule, glenohumeral ligaments, and rotator cuff is also mandatory as their presence influences the surgical outcome. Rehabilitation, arthroscopic repair techniques, open Bankart procedure, capsular plication, remplissage, Latarjet technique, iliac crest, and other bone grafts offer the surgeon different treatment options according to the type of patient and the lesions to be treated. Three-dimensional (3D) technologies can help to evaluate glenoid and humeral defects. Patient-specific guides are low-cost surgical instruments and can be used in shoulder instability surgery. 3D printing will undoubtedly become an essential tool to achieve the best results in glenohumeral instability surgery.

Determining On-/Off-track Lesions in Glenohumeral Dislocation Using Multiplanar Reconstruction Computed Tomography Is Easier and More Reproducible Than Using 3-dimensional Computed Tomography

Background: The glenoid track is a useful tool to predict engagement and therefore the risk of recurrence of dislocation in the presence of Hill-Sachs and/or bony Bankart lesions. To assess the glenoid track preoperatively, only methods using 3-dimensional reconstruction (3DR) have been described, but these lack a standardized, reliable, and easy description. Purpose/Hypothesis: The purpose was to evaluate a new method for determining the glenoid track using computed tomography (CT) scan with multiplanar reconstruction (MPR) in comparison with using 3DR images. Our hypothesis was that the MPR method would be easier to standardize and more reproducible. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 52 patients whose arthro-CT scan revealed a Hill-Sachs lesion, whether in combination with a bony Bankart lesion or not, were included. Digital Imaging and Communications in Medicine data from the 52 CT scans were all analyzed using open source image analysis software. Glenoid width, with or without associated bony defect, and the Hill-Sachs interval (HSI) were measured on MPR as well as on 3DR images. All measurements obtained using both methods were directly compared and evaluated for intra- and interobserver reliability. Results: In absolute values, only small differences were seen between the MPR and 3DR methods, amounting to a maximal difference of 0.07 cm for the HSI and 0.04 cm for the glenoid width. For glenoid measurements, both methods were similar. For humeral measurements, the MPR method demonstrated higher inter- and intraobserver reliability than did the 3DR method. Conclusion: The newly described MPR method for the assessment of the glenoid track and HSI is at least as accurate as the published 3DR method, with better intra- and interobserver reliability. Because MPRs are also easier to obtain, this method could be recommended in daily practice.

A avaliação do método tomográfico glenoid track na ressonância magnética/artro RM

Resumo Objetivo Comparar a avaliação do método glenoid-track (GT) em exames de tomografia computadorizada com reconstrução 3-D (TC-3D) com a avaliação realizada em exames de ressonância magnética (RM) e/ou artro-ressonância magnética (ARM). Métodos Quarenta e quatro ombros com diagnóstico clínico e radiográfico de instabilidade anterior traumática foram avaliados por meio de exames de TC-3D, RM e/ou ARM. As variáveis GT, intervalo de Hill-Sachs (IHS) e a perda óssea da glenoide (POG) foram realizadas por um médico radiologista, utilizando imagens de TC-3D, e classificadas em on-track/off-track. Três cirurgiões cegos à avaliação do radiologista realizaram o mesmo método utilizando RM/ARM. O estudo realizou análise descritiva, de variância, de associação da discordância de resultados, de concordância e curva característica de operação do receptor. Resultados Os resultados dos 4 examinadores foram totalmente concordantes em 61,4%. A RM/ARM diagnosticou lesões off-track com a sensibilidade variando de 35 a 65%, e lesões on-track com a especificidade variando de 91,67 a 95,83%. A acurácia variou de 68,1 a 79,5%. A maior divergência de dados ocorreu para o diagnóstico por RM/ARM de lesões off-track. A maior variabilidade dos dados ocorreu para o cálculo do IHS. Valores maiores de IHS e de POG foram associados a maior discordância entre os examinadores. A RM/ARM apresentou menor medida de valores de IHS quando comparado com a TC-3D. Ocorreu apenas moderada concordância no método GT entre a TC e a RM/ARM (Kappa 0,325–0,579). Conclusão A RM/ARM apresentou baixa acurácia e moderada concordância para o método GT, devendo ser utilizada com cautela por cirurgiões.

Combined subcritical thresholds of glenoid and humeral sided bone loss are predictive of failure after arthroscopic Bankart repair

Objectives: Glenoid and humeral sided bone loss are both independent risk factors for failure after arthroscopic Bankart repair. The purpose of this study was to determine the combined effect of subcritical levels of humeral and glenoid sided bone loss on failure after arthroscopic Bankart repair. Methods: 171 individuals with minimum 2 years follow up who underwent primary arthroscopic Bankart repair between 2007-2015 were included in this study. Glenoid and humeral sided bone loss were measured using the glenoid track model. Cases were defined as individuals who sustained a subluxation or dislocation event after the index procedure, while controls were defined as individuals who did not. Subjects were stratified by age (20+ versus < 20 years). Receiver operating curves (ROC) were generated to determine the threshold of glenoid and humeral sided bone loss that could best predict failure. Results: There were 53 cases and 118 controls. Increased glenoid (p < .001) and humeral-sided (p = .013) bone loss independently predicted failure. ROC analysis demonstrated that threshold values of 12% glenoid (AUC = 0.62) and 13 mm humeral (AUC = 0.60) bone loss were predictive of failure. Combined subcritical thresholds of 10% glenoid and 10 mm humeral sided bone loss successfully predicted outcomes of 49/56 (87.5%) individuals over age 20 and 79/117 (67.5%) individuals under age 20. Humeral and glenoid sided bone loss had an additive effect on risk of failure in older individuals while glenoid sided bone loss was primarily responsible for failure in younger individuals. Conclusion: Both glenoid and humeral sided bone loss are predictive of failure after arthroscopic Bankart repair. Combined subcritical thresholds of glenoid and humeral sided bone loss accurately predict failure, particularly in individuals over the age of 20. These results suggest that individuals with subcritical bipolar lesions may be at higher risk of failure after arthroscopic Bankart repair than previously thought. [Table: see text]