Diagnostic accuracy of non-contrast MRI in frozen shoulder.

INTRODUCTION: Despite being the most used exam today, few studies have evaluated the accuracy of findings on non-contrast magnetic resonance imaging (MRI). The primary objective of the study was to evaluate the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of non-contrast MRI findings in frozen shoulder, isolated and in combination. The secondary objectives were to define the interobserver and intraobserver agreement of the assessments and the odds ratio for frozen shoulder because of the various findings of MRI. METHODS: A retrospective diagnostic accuracy study comparing non-contrast MRI findings between the frozen shoulder group and the control group. Sensitivity, specificity, positive and negative predictive value, accuracy, odds ratio, interobserver and intraobserver agreement were calculated for each finding and their possible associations. RESULTS: The hyperintensity on capsule in the axillary recess presented 84% sensitivity, 94% specificity, and 89% accuracy. The obliteration of the subcoracoid fat triangle in the rotator interval had sensitivity 34%, specificity 82% and accuracy 58%. For coracohumeral ligament thickness ≥ 2 mm had specificity 66%, 48% specificity and 57% accuracy. Capsule thickness in the axillary recess ≥ 4 mm resulted in 54% sensitivity, 82% specificity, and 68% accuracy. Regarding interobserver agreement, only the posteroinferior and posterosuperior quadrants showed moderate results, and all the others showed strong reliability. The odds ratio for hyperintensity in the axillary recess was 82.3 for frozen shoulder. The association of these findings increased specificity (95%). CONCLUSION: The accuracy of non-contrast magnetic resonance imaging is high for diagnosing frozen shoulder, especially when evaluating the hyperintensity of the axillary recess. The exam has high reliability and reproducibility. The presence of an association of signs increases the specificity of the test. LEVEL OF EVIDENCE: Level III, study of diagnostic test.

Matrix Metalloproteases 8 Polymorphism as Risk Factor for Rotator Cuff Tear.

Objectives: Rotator Cuff Tear (RCT) is a multifactorial disease, but an important one is the increased collagen degradation that would lead to a higher chance of tear. MMP-8 is a protein that degrades type I collagen, and it is known that MMP-8 has a polymorphism in which a T allele in the gene promoter region increases its transcription activity. This study aims to investigate the association between MMP-8 polymorphism g.-799 C>T (rs11225394) and RCT. Methods: To do that, we collected DNA samples from buccal epithelial cells of 128 patients (separated into RCT group and control group in a proportion 1:1) and genotyped the DNA using PCR. The statistical analyses were done using the ARLEQUIN Version 2.0, and the data normality was tested with the Shapiro-Wilk test. Results: The results showed a significantly higher frequency of T/T genotype in the test group (29% in the control group and 39% in the test group, p=0.0417), and that would represent a risk factor for increased collagen degradation. Conclusion: The MMP-8 g.-799 C>T (rs11225394) SNP was associated with RCT. With the description of a new risk factor, future research can be done to analyze how to prevent RCT or develop new treatment strategies since the disease's failure index is currently high.

Using Machine Learning to Predict Nonachievement of Clinically Significant Outcomes After Rotator Cuff Repair.

Background: Although some evidence suggests that machine learning algorithms may outperform classical statistical methods in prognosis prediction for several orthopaedic surgeries, to our knowledge, no study has yet used machine learning to predict patient-reported outcome measures after rotator cuff repair. Purpose: To determine whether machine learning algorithms using preoperative data can predict the nonachievement of the minimal clinically important difference (MCID) of disability at 2 years after rotator cuff surgical repair with a similar performance to that of other machine learning studies in the orthopaedic surgery literature. Study Design: Case-control study; Level of evidence, 3. Methods: We evaluated 474 patients (n = 500 shoulders) with rotator cuff tears who underwent arthroscopic rotator cuff repair between January 2013 and April 2019. The study outcome was the difference between the preoperative and 24-month postoperative American Shoulder and Elbow Surgeons (ASES) score. A cutoff score was calculated based on the established MCID of 15.2 points to separate success (higher than the cutoff) from failure (lower than the cutoff). Routinely collected imaging, clinical, and demographic data were used to train 8 machine learning algorithms (random forest classifier; light gradient boosting machine [LightGBM]; decision tree classifier; extra trees classifier; logistic regression; extreme gradient boosting [XGBoost]; k-nearest neighbors [KNN] classifier; and CatBoost classifier). We used a random sample of 70% of patients to train the algorithms, and 30% were left for performance assessment, simulating new data. The performance of the models was evaluated with the area under the receiver operating characteristic curve (AUC). Results: The AUCs for all algorithms ranged from 0.58 to 0.68. The random forest classifier and LightGBM presented the highest AUC values (0.68 [95% CI, 0.48-0.79] and 0.67 [95% CI, 0.43-0.75], respectively) of the 8 machine learning algorithms. Most of the machine learning algorithms outperformed logistic regression (AUC, 0.59 [95% CI, 0.48-0.81]); nonetheless, their performance was lower than that of other machine learning studies in the orthopaedic surgery literature. Conclusion: Machine learning algorithms demonstrated some ability to predict the nonachievement of the MCID on the ASES 2 years after rotator cuff repair surgery.

A numerical study of the contact geometry and pressure distribution along the glenoid track.

The glenoid track geometry and the contact forces acting on the glenohumeral joint at static positions of 30°, 60°, 90° and 120° of abduction with 90° of external rotation were evaluated using a finite element model of the shoulder that, differently from most usual approximations, accounts the humeral head translations and the deformable-to-deformable non-spherical joint contact. The model was based on data acquired from clinical exams of a single subject, including the proximal humerus, scapula, their respective cartilages concerning the glenohumeral joint, and the rotator cuff and deltoid muscles. The forces acting on the glenohumeral joint were estimated using a simulation framework consisting of an optimization procedure allied with finite element analysis that seeks the minimum muscle forces that stabilize the joint. The joint reaction force magnitude increases up to 680.25 N at 90° of abduction and decreases at further positions. From 60° onward the articular contact remains at the anterior region of the glenoid cartilage and follows an inferior to superior path at the posterior region of the humeral head cartilage. The maximum contact pressure of 3.104 MPa occurs at 90° abduction. Although translating inferiorly throughout the movement, the projection of the humeral head center at the glenoid plane remains at the central region of the glenoid surface. The model results qualitatively matched the trends observed in the literature and supports the consideration of the translational degrees of freedom to evaluate the joint contact mechanics.

Treatment of Irreparable Rotator Cuff Tears: Superior Capsular Reconstruction with Fascia Lata Allograft.

Objective The objective of the present study was to evaluate the efficacy and safety of superior capsular reconstruction (SCR) using fascia lata allograft. Methods A prospective case series of 15 patients with irreparable supraspinatus tear who underwent SCR using fascia lata allograft. The American Shoulder and Elbow Surgeons (ASES) scale at 12 months after surgery was the primary outcome. The University of California Los Angeles (UCLA), Constant-Murley, and Single Assessment Numeric Evaluation (SANE) scales, in addition to the range of motion, were secondary outcomes. Radiological parameters were also evaluated by simple radiographs and magnetic resonance imaging (MRI). Results Fifteen patients completed 12 months of postoperative follow-up. The ASES score increased from 34.0 to 73.0 ( p = 0.005). The UCLA, Constant-Murley, and SANE scales also showed statistically significant differences ( p = 0.001; p = 0.005; and p = 0.046). In the evaluation of range of motion, there was improvement in elevation and in external rotation (95 to 140°, p = 0.003; 30 to 60°, p = 0.007). Six patients (40%) had complete graft healing. The clinical outcomes were significantly higher in the patients who presented graft healing. Conclusions Superior capsular reconstruction using a fascia lata allograft is a safe and effective procedure in short follow-up. Level of Evidence IV; Therapeutic Study; Case Series.

THE POLYMORPHISM OF METALLOPROTEINASES 1 AND 13 AND POSTTRAUMATIC ELBOW STIFFNESS.

Introduction: To evaluate the relationship between the genetic polymorphism of matrix metalloproteinases 1 and 13 and posttraumatic elbow stiffness, as well as the association of other risk factors with this condition. Materials and methods: We evaluated 20 patients with posttraumatic elbow stiffness and 12 controls with traumatic elbow disorders without contracture. Deoxyribonucleic acid (DNA) was obtained from buccal mucosa epithelial cells of the volunteers. The MMP-1 and MMP-13 genotypes were determined using PCR-restriction fragment length polymorphism assays. Results: We did not find any significant differences in the frequency of genotypes and alleles between the test and control groups for the polymorphism of metalloproteinases 1 and 13. We observed that genotypes 1G/2G and 2G/2G of MMP-1 were present in 65% (13/20) of patients with articular stiffness and 50% (6/12) of controls (p = 0.599). Genotypes A/A and A/G of MMP-13 were obtained in 95% (19/20) of patients and 91.6% (11/12) of controls (p = 0.491). Among the prognostic factors for elbow stiffness, only immobilization time correlated positively. The mean immobilization time for cases and controls were 16 ± 10 days and 7 ± 7 days, respectively (p = 0.017). Conclusion: The genetic polymorphism of MMP-1 at position -1607 and MMP-13 at position -77 was not associated with post-traumatic elbow stiffness. Level of Evidence III; Prognosis Study; Case-Control Study.

Introdução: Avaliar a relação entre o polimorfismo genético das metaloproteinases 1 e 13 da matriz e a rigidez pós-traumática do cotovelo, assim como a associação de outros fatores de risco com essa condição. Material e método: Foram avaliados 20 pacientes com rigidez pós-traumática do cotovelo e 12 controles com distúrbios traumáticos do cotovelo sem contratura. O ácido desoxirribonucleico (DNA) de voluntários foi obtido a partir de células epiteliais da mucosa bucal. Os genótipos MMP-1 e MMP-13 foram determinados usando ensaios de polimorfismo de comprimento de fragmento de restrição de PCR. Resultados: Não encontramos diferença significativa na frequência de genótipos e alelos entre os grupos teste e controle para o polimorfismo das metaloproteinases 1 e 13. Observamos que os genótipos 1G/2G e 2G/2G de MMP-1 estavam presentes em 65% (13/20) dos pacientes com rigidez articular e 50% (6/12) dos controles (p = 0,599). Os genótipos A/A e A/G da MMP-13 foram obtidos em 95% (19/20) dos pacientes e 91,6% (11/12) dos controles (p = 0,491). Dentre os fatores prognósticos para rigidez de cotovelo, apenas o tempo de imobilização se correlacionou positivamente. O tempo médio de imobilização para casos e controles foi de 16 ± 10 dias e 7 ± 7 dias, respectivamente (p = 0,017). Conclusões: O polimorfismo genético de MMP-1 na posição -1607 e MMP-13 na posição -77 não foi associado à rigidez pós-traumática do cotovelo. Nível de Evidência III; Estudos Prognósticos; Estudo de Caso-Controle.

The polymorphism of metalloproteinases 1 and 13 and posttraumatic elbow stiffness / O polimorfismo das metaloproteinases 1 e 13 e a rigidez articular pós-traumática do cotovelo

ABSTRACT Introduction To evaluate the relationship between the genetic polymorphism of matrix metalloproteinases 1 and 13 and posttraumatic elbow stiffness, as well as the association of other risk factors with this condition. Materials and methods We evaluated 20 patients with posttraumatic elbow stiffness and 12 controls with traumatic elbow disorders without contracture. Deoxyribonucleic acid (DNA) was obtained from buccal mucosa epithelial cells of the volunteers. The MMP-1 and MMP-13 genotypes were determined using PCR-restriction fragment length polymorphism assays. Results We did not find any significant differences in the frequency of genotypes and alleles between the test and control groups for the polymorphism of metalloproteinases 1 and 13. We observed that genotypes 1G/2G and 2G/2G of MMP-1 were present in 65% (13/20) of patients with articular stiffness and 50% (6/12) of controls (p = 0.599). Genotypes A/A and A/G of MMP-13 were obtained in 95% (19/20) of patients and 91.6% (11/12) of controls (p = 0.491). Among the prognostic factors for elbow stiffness, only immobilization time correlated positively. The mean immobilization time for cases and controls were 16 ± 10 days and 7 ± 7 days, respectively (p = 0.017). Conclusion The genetic polymorphism of MMP-1 at position -1607 and MMP-13 at position -77 was not associated with post-traumatic elbow stiffness. Level of Evidence III; Prognosis Study; Case-Control Study.

RESUMO Introdução Avaliar a relação entre o polimorfismo genético das metaloproteinases 1 e 13 da matriz e a rigidez pós-traumática do cotovelo, assim como a associação de outros fatores de risco com essa condição. Material e método Foram avaliados 20 pacientes com rigidez pós-traumática do cotovelo e 12 controles com distúrbios traumáticos do cotovelo sem contratura. O ácido desoxirribonucleico (DNA) de voluntários foi obtido a partir de células epiteliais da mucosa bucal. Os genótipos MMP-1 e MMP-13 foram determinados usando ensaios de polimorfismo de comprimento de fragmento de restrição de PCR. Resultados Não encontramos diferença significativa na frequência de genótipos e alelos entre os grupos teste e controle para o polimorfismo das metaloproteinases 1 e 13. Observamos que os genótipos 1G/2G e 2G/2G de MMP-1 estavam presentes em 65% (13/20) dos pacientes com rigidez articular e 50% (6/12) dos controles (p = 0,599). Os genótipos A/A e A/G da MMP-13 foram obtidos em 95% (19/20) dos pacientes e 91,6% (11/12) dos controles (p = 0,491). Dentre os fatores prognósticos para rigidez de cotovelo, apenas o tempo de imobilização se correlacionou positivamente. O tempo médio de imobilização para casos e controles foi de 16 ± 10 dias e 7 ± 7 dias, respectivamente (p = 0,017). Conclusões O polimorfismo genético de MMP-1 na posição -1607 e MMP-13 na posição -77 não foi associado à rigidez pós-traumática do cotovelo. Nível de Evidência III; Estudos Prognósticos; Estudo de Caso-Controle.

Humeral internal rotation osteotomy for the treatment of Erb-Duchenne-type obstetric palsy: clinical and radiographic results

OBJECTIVE: To evaluate the functional and radiographic results in patients undergoing shoulder anterior soft tissue stretching in association with open reduction and internal rotation osteotomy to centralize the humeral head as a treatment for Erb-Duchenne obstetric palsy sequelae. METHOD: A total of 35 patients underwent this surgical treatment, and the mean follow-up was 4.6 years. The Mallet scale was applied before and after the surgical procedure. A total of 20 patients underwent computed tomography to assess the glenoid version and humeral head subluxation. RESULTS: Functional improvement was achieved, as evidenced by an increase in the Mallet scale score from 12.14 to 16.46 (p<0.001). The correction of retroversion was achieved once the glenoid version ranged from -21.4 to -12 degrees (p<0.001). The humeral head subluxation improved from 6.5 to 35.2% (p<0.001). Patients older than 6 years of age did not achieve glenohumeral joint improvement with respect to dysplastic abnormalities. CONCLUSION: Internal rotation osteotomy in association with the stretching of anterior soft tissues of the shoulder in patients under the age of 7 years provided improvements in the function, retroversion, and subluxation of the glenohumeral joint. .

Outcomes evaluation of locking plate osteosynthesis in displaced fractures of the proximal humerus.

OBJECTIVE: To evaluate functional outcomes, radiographic findings and complications of proximal humeral fractures treated with locking plates and to determine prognostic factors for successful clinical outcomes. METHODS: Forty patients undergoing internal fixation of fractures of the proximal humerus with the Philos® plate were included in the study. The surgeries were performed between 2004 and 2011 and the patients underwent radiographic and clinical evaluation, by Constant-Murley and Dash score. Outcomes were analyzed by use of multivariate regression with several different variables. RESULTS: Patients were on average of 61.8 ± 16.28 years, and most were female (70%). The Constant-Murley score was 72.03 ± 14.01 and Dash score was 24.96 ± 19.99. The postoperative radiographs showed a head-shaft angle of 135.43° ± 11.82. Regression analysis showed that the patient's age and the Hertel classification influenced the Constant-Murley scale (p = 0.0049 and 0.012, respectively). Other prognostic criteria such as Neer and AO classification, head-shaft angle, the presence of metaphyseal comminution and extension of the humeral metaphyseal fragment showed no effect on prognosis. Complications occurred in four patients (10%). CONCLUSION: The fixation with the Philos® plate provided good clinical and radiographic results in fractures of the proximal humerus, with a low complication rate. Patient's age and Hertel classification were defined as prognostic factors that led to worse functional outcomes.

OBJETIVO: Avaliar os resultados clínicos e radiográficos e as complicações das fraturas do terço proximal do úmero tratadas com a placa Philos® e correlacionar esses resultados com critérios prognósticos. MÉTODOS: Foram estudados 40 pacientes submetidos a osteossíntese de fraturas do terço proximal do úmero com a placa Philos®. As cirurgias foram feitas entre 2004 e 2011 e os pacientes foram submetidos a avaliação funcional (escalas de Constant­Murley e Dash [Disability of Arm-Shoulder-Hand]) e radiográfica. Os resultados funcionais foram correlacionados com variáveis clínicas e radiográficas por meio de regressão múltipla. RESULTADOS: Os pacientes apresentavam em média 61,8 ± 16,28 anos e a maioria era do sexo feminino (70%). Observamos pontuação de 72,03 ± 14,01 pela escala de Constant­Murley e 24,96 ± 19,99 pela de Dash. A radiografia pós-operatória evidenciou um ângulo cabeça-diáfise de 135,43° ± 11,82. A análise por regressão demonstrou que a idade do paciente e a classificação de Hertel exercem influência direta na escala de Constant­Murley (p = 0,0049 e 0,012, respectivamente). Outros critérios prognósticos, como a classificação de Neer e AO, o ângulo cabeça-diáfise, a presença de cominuição metafisária e a extensão do fragmento metafisário não demonstraram influência no prognóstico em nossa amostra. Complicações ocorreram em quatro pacientes (10%). CONCLUSÃO: A osteossíntese com a placa Philos® proporcionou, em nossa amostra, bons resultados clínicos e radiográficos, com baixo índice de complicações. A idade do paciente e a classificação de Hertel foram demonstradas como fatores preditores do resultado funcional.

PLATELET-RICH PLASMA IN ARTHROSCOPIC REPAIRS OF COMPLETE TEARS OF THE ROTATOR CUFF.

OBJECTIVE: To evaluate shoulder functional results and the retear rate of arthroscopic repair of the rotator cuff augmented with platelet-rich plasma (PRP). METHODS: Prospective case series with single-row arthroscopic repair of the rotator cuff augmented with PRP. Only cases of isolated supraspinatus tears with retraction of less than 3 cm were included in this series. The PRP used was obtained by apheresis. It was applied on liquid consistency in its activated form, with the addition of autologous thrombin. Patients were evaluated after 12 months of the surgical procedure. The Constant-Murley, UCLA and VAS scales were used, and the retear rate was assessed using magnetic resonance imaging (MRI). RESULTS: Fourteen patients were evaluated (14 shoulders). The mean Constant-Murley score was 45.64 ± 12.29 before the operation and evolved to 80.78 ± 13.22 after the operation (p < 0.001). The UCLA score increased from 13.78 ± 5.66 to 31.43 ± 3.9 (p < 0.001). The patients' pain level decreased from a median of 7.5 (p25% = 6, p75% = 8) to 0.5 (p25% = 0, p75% = 3) (p = 0.0013) according to the VAS score. None of the patients presented complete retear. Three patients (21.4%) showed partial retear, without transfixation. Only one patient developed complications (adhesive capsulitis). CONCLUSION: Patients submitted to arthroscopic rotator cuff repair augmented with PRP showed significant functional improvement and none of them had complete retearing.

RESULTS FROM BI-CONTACT(®) TOTAL ELBOW ARTHROPLASTY: MULTICENTER STUDY.

OBJECTIVE: To describe the initial experience of four orthopedic clinics from using Bi-Contact(®) total elbow arthroplasty (TEA), reporting the results and complications of the procedure. METHODS: This was a retrospective study, through analysis on the medical records of patients who underwent primary TEA using a prosthesis model developed in conjunction with IOT-HCFMUSP. Forty-six elbows (45 patients) that were operated at four orthopedic clinics between 2000 and 2009 were evaluated. RESULTS: The majority of the patients were female (74%), and the median age was 62.5 years. The diagnoses encountered were trauma sequelae (47.83%), rheumatoid arthritis (32.61%), primary osteoarthrosis (8.7%), acute fractures (6.52%) and heterotopic ossification (2.17%). The median length of follow-up was 2.08 years (0.25-9). The procedure significantly alleviated pain and improved range of motion. It was observed that at least one complication was present in 69.57% of the cases, and the main ones were infection (28.26%), need for revision (28.26%), intraoperative fracture (15.22%) and aseptic loosening (15.22%). CONCLUSION: Bi-Contact(®) TEA provided significant alleviation of pain and improvement of range of motion in the present series. The complication rate was high, and the most frequently observed complications were infection, aseptic loosening and intraoperative fracture.

RESULTS FROM FILLING "REMPLISSAGE" ARTHROSCOPIC TECHNIQUE FOR RECURRENT ANTERIOR SHOULDER DISLOCATION.

OBJECTIVE: To evaluate the clinical result from the filling ("remplissage") technique in association with Bankart lesion repair for treating recurrent anterior shoulder dislocation. METHODS: Nine patients (10 shoulders), with a mean follow-up of 13.7 months, presented traumatic recurrent anterior shoulder dislocation. All of them had a Bankart lesion, associated with a Hill-Sachs lesion showing the "engaging" sign. The Hill-Sachs lesion defect was measured and showed an average bone loss of 17.3% (7.7% to 26.7%) in relation to the diameter of the humeral head. All the cases underwent arthroscopic repair of the Bankart lesion, together with filling of the Hill-Sachs lesion by means of tenodesis of the infraspinatus. RESULTS: The Rowe score ranged from 22.5 (10 to 45) before the operation to 80.5 (5 to 100) after the operation (p > 0.001). The UCLA score ranged from 18.0 (8 to 29) to 31.1 (21 to 31) (p > 0.001). The measurements of external and internal rotation at abduction of 90° after the operation were 63.5° (45° to 90°) and 73° (50° to 92°) respectively. Two patients presented recurrence (one with dislocation and the other with subluxation). None of the patients presented pain in the region of the infraspinatus tendon after the operation. CONCLUSION: Over the short term, the filling ("remplissage") arthroscopic technique produced improvements in functional scores and a low complication rate when used for treating glenohumeral instability associated with Hill-Sachs lesions.

ARTHROSCOPIC TREATMENT OF CALCIFYING TENDINITIS OF THE ROTATOR CUFF.

UNLABELLED: To evaluate the clinical and radiographic results from arthroscopic surgical treatment of the rotator cuff in patients with calcifying tendinitis. METHOD: A retrospective study was conducted on twenty patients who underwent arthroscopic treatment for calcifying tendinitis of the shoulder between March 1999 and November 2005. Six patients were excluded due to loss of follow-up. The average follow-up period was 41.4 months. Eight patients (57%) were female and six (43%) were male. The right side was affected in 10 cases (71%) and the left in four cases (29%). Nine cases (64%) had calcification in the supraspinatus tendon, two (14%) in the infraspinatus tendon, and three (21%) in both tendons. RESULTS: In all cases, resection of the calcium deposits was performed by means of a needle (Jelco® No. 14) in combination with curettage (mini-curette). Two shoulders (14%) underwent subacromial decompression, and one (7%) underwent excision of the distal clavicle. A tendon-tendon suture was performed in three shoulders (21%). None of the patients underwent tendon-bone reinsertion. The mean score obtained on the UCLA scale was 33 points (26-35), thus indicating that a majority of patients had good results. In the final radiographic evaluation, none of the patients showed signs of calcification. CONCLUSION: Arthroscopic treatment of calcifying tendinitis of the shoulder safely allows excision of the calcification, leading to good results in relation to shoulder pain and function.