Diagnostic accuracy of MRI in the measurement of glenoid bone loss.

OBJECTIVE: The purpose of this study is to assess the accuracy of MRI quantification of glenoid bone loss and to compare the diagnostic accuracy of MRI to CT in the measurement of glenoid bone loss. MATERIALS AND METHODS: MRI, CT, and 3D CT examinations of 18 cadaveric glenoids were obtained after the creation of defects along the anterior and anteroinferior glenoid. The defects were measured by three readers separately and blindly using the circle method. These measurements were compared with measurements made on digital photographic images of the cadaveric glenoids. Paired sample Student t tests were used to compare the imaging modalities. Concordance correlation coefficients were also calculated to measure interobserver agreement. RESULTS: Our data show that MRI could be used to accurately measure glenoid bone loss with a small margin of error (mean, 3.44%; range, 2.06-5.94%) in estimated percentage loss. MRI accuracy was similar to that of both CT and 3D CT for glenoid loss measurements in our study for the readers familiar with the circle method, with 1.3% as the maximum expected difference in accuracy of the percentage bone loss between the different modalities (95% confidence). CONCLUSION: Glenoid bone loss can be accurately measured on MRI using the circle method. The MRI quantification of glenoid bone loss compares favorably to measurements obtained using 3D CT and CT. The accuracy of the measurements correlates with the level of training, and a learning curve is expected before mastering this technique.

Comparison of ultrasound-guided versus blind glenohumeral injections: a cadaveric study.

BACKGROUND: Intra-articular glenohumeral (GH) injections are important for diagnostic and therapeutic purposes. It has been suggested that ultrasound guided injections are more accurate than blind or freehand injections. This study assessed the accuracy of ultrasound-guided GH injections compared with freehand injections in fresh cadavers. METHODS: The study used 80 shoulder specimens from fresh cadavers. Ultrasound guidance was used to inject radiopaque contrast in 40 shoulders, and freehand technique was used in the remaining 40. All injections were performed by 2 surgeons (A and B) through a posterior approach. After the injections, radiographs were obtained of the specimens to assess the accuracy of the injections. RESULTS: Sixty-six of 80 (82.5%) injections were accurately administered into the GH joint. Ultrasound-guided injections were accurate in 37 of 40 specimens (92.5%) compared with freehand injections, which were accurate in only 29 of 40 specimens (72.5%; P = .02). Both surgeons independently had higher accuracy using ultrasound-guidance compared with the freehand technique (surgeon A: 90% vs 65%, P = 0.058; surgeon B: 95% vs 80%, P = 0.15). The average time for injections was 52 seconds by the freehand technique and 166 seconds using ultrasound guidance (P < 0.001). CONCLUSIONS: The data from this cadaveric study suggest that ultrasound-guided injections are more accurate at reaching the GH joint than freehand injections. The ultrasound-guided injections took substantially longer to administer. Once familiar with the technique, surgeons can expect improved accuracy and efficacy of GH joint injections using ultrasound guidance in the clinical setting.

Early aseptic loosening of the Tritanium primary acetabular component with screw fixation.

Ultraporous acetabular components were developed to improve osseointegration and fit for increased longevity and better outcomes after total hip arthroplasty. There is a paucity of literature detailing this acetabular component's clinical performance, with even less detailing those with screw fixation. We identify 5 patients at our institution who underwent revision total hip arthroplasty for early aseptic acetabular cup loosening of an ultraporous acetabular component known as the Tritanium primary cup with secondary screw fixation. They all presented with groin and hip pain after index surgery and underwent follow-up radiographic examination consistent with component loosening requiring revision surgery. This case series reports on the risk of early acetabular cup loosening and its associated clinical presentation, workup, and surgical management in patients with the Tritanium primary cup augmented with screws.

Physician Training Ultrasound and Accuracy of Diagnosis in Rotator Cuff Tears.

INTRODUCTION: Ultrasonography offers a fast and inexpensive method to evaluate the rotator cuff in the office setting. However, the accuracy of ultrasound is highly user dependent. The purpose of this study is to investigate the learning curve of an orthopaedic surgeon in using ultrasound to diagnose rotator cuff tears. METHODS: A sports medicine fellowship trained orthopaedic surgeon was taught how to perform and interpret an ultrasound examination of the shoulder by a musculoskeletal radiologist. In this prospective study, subjects were patients who presented to the office with shoulder pain suspected to be consistent with rotator cuff pathology, either complete or partial tears. The surgeon was blinded to magnetic resonance imaging (MRI) results and performed the ultrasound after performing a physical exam. Based on ultrasound and exam, the surgeon assessed if the rotator cuff was intact (no tear) or torn (having a partial or full thickness tear). Results were compared to MRI findings and arthroscopic findings (when available), and accuracy was evaluated over time to determine overall accuracy and if significant learning and improvement in accuracy took place over the time period studied. RESULTS: Eighty patients were enrolled in the study; seventy-four had an MRI within 3 months of the ultrasound and were available for evaluation. Nineteen patients underwent ultrasound, MRI, and arthroscopy. Ultrasound was able to accurately diagnose the correct rotator cuff pathology (no tear, a partial thickness tear, or a full thickness tear) in 61% of patients. Ultrasound accurately diagnosed simply the presence or absence of a tear in 74% of patients. There was a general trend toward improved accuracy as the investigator gained experience, with accuracy rates of approximately 51% for the first 40 patients, and 69% for the last 40 patients evaluated, although this difference was not statistically significant (p = 0.154). DISCUSSION: Ultrasound imaging requires significant training and practice to provide a clinically useful level of diagnostic accuracy. The applicability of this procedure for diagnosing primary rotator cuff tears in an orthopaedic office setting may be limited by the time and volume required for the practitioner to approach the accuracy reported for diagnostic ultrasound and MRI in the literature.

Early Versus Delayed Passive Range of Motion After Rotator Cuff Repair: A Systematic Review and Meta-analysis.

BACKGROUND: Postoperative rehabilitation has been shown to affect healing of the rotator cuff after surgical repair. However, it is unknown whether an early or delayed rehabilitation protocol is most beneficial for healing. PURPOSE: To determine whether early versus delayed passive range of motion (PROM) affects rotator cuff (RC) retear rates after surgery. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A systematic review of the literature published between January 2003 and February 2014 was conducted. Retear rates were compared for early (within 1 week after surgery) versus delayed (3-6 weeks after surgery) PROM using χ(2) or Fisher exact tests as well as relative risks (RR) and 95% CIs. In the first analysis, data from evidence level 1 studies that directly compared early versus delayed PROM were pooled; and in the second analysis, data from level 1 to 4 studies that did not directly compare early versus delayed PROM were pooled. The second analysis was stratified by tear size and repair method. RESULTS: Twenty-eight studies (1729 repairs) were included. The first analysis of level 1 studies did not reveal a significant difference in retear rates for early (13.7%) versus delayed (10.5%) PROM (P = .36; RR = 1.30 [95% CI, 0.74-2.30]). The second analysis revealed that for ≤3 cm tears, the risk of retear was lower for early versus delayed PROM for transosseous (TO) plus single-row anchor (SA) repairs (18.7% vs 28.2%, P = .02; RR = 0.66 [95% CI, 0.47-0.95]). For >5 cm tears, the risk of retear was greater for early versus delayed PROM for double-row anchor (DA) repairs (56.4% vs 20%, P = .002; RR = 2.82 [95% CI, 1.31-6.07]) and for all repair methods combined (52.2% vs 22.6%, P = .01; RR = 2.31 [95% CI, 1.16-4.61]). There were no statistically significant associations for tears measuring <1 cm, 1 to 3 cm, 3 to 5 cm, and >3 cm. CONCLUSION: Evidence is lacking with regard to the optimal timing of PROM after RC repair; however, this study suggests that tear size may be influential.

Complications using bioabsorbable cross-pin femoral fixation: a case report and review of the literature.

The use of bioabsorbable cross-pin transcondylar fixation has remained a viable option for femoral fixation in anterior cruciate ligament reconstruction. Although numerous biomechanical studies have demonstrated high fixation strength and minimal slippage with use of this method of fixation, there have been increasing reports of a variety of clinical complications associated with these implants. We reviewed the literature for all complications associated with the Bio-TransFix implant and present a case report of a patient status after ACL reconstruction using Bio-TransFix cross-pin femoral fixation with iliotibial band friction syndrome from a broken cross-pin four month post-operatively.

Rupture of the distal biceps tendon combined with a supinator muscle tear in a 51-year-old woman: a case report.

Distal biceps tendon rupture is a relatively uncommon occurrence in the general female population, and to our knowledge, has not been reported in association with a supinator muscle tear. We report a case of 51-year-old woman who experienced sharp pain in her forearm and elbow after lifting a heavy object. History and physical examination raised suspicion for a distal biceps tendon rupture. MRI imaging determined a combined distal biceps tendon tear with a supinator muscle tear with subsequent confirmation at surgery. Surgical repair was performed for the distal biceps tendon only through a single incision approach using the Endobutton technique.

Transcriptome analysis of Crp-dependent catabolite control of gene expression in Escherichia coli.

We report here the transcriptome analyses of highly expressed genes that are subject to catabolite repression or activation mediated by the cyclic AMP receptor protein (Crp). The results reveal that many operons encoding enzymes of central carbon metabolic pathways (e.g., Krebs cycle enzymes), as well as transporters and enzymes that initiate carbon metabolism, are subject to direct Crp-mediated catabolite repression. By contrast, few enzyme-encoding genes (direct regulation) but many ribosomal protein- and tRNA-encoding genes (indirect regulation) are subject to Crp-dependent glucose activation. Additionally, Crp mediates strong indirect catabolite repression of many cytoplasmic stress response proteins, including the major chaperone proteins, five ATP-dependent protease complexes, and several cold and heat shock proteins. These results were confirmed by (i) phenotypic analyses, (ii) real-time PCR studies, (iii) reporter gene fusion assays, and (iv) previously published reports about representative genes. The results serve to define and extend our appreciation of the Crp regulon.