Faculty Bibliography

OBJECTIVE:A major factor that impacts the long-term outcome and complication rates of total shoulder arthroplasty is the preoperative posterior glenoid bone loss quantified by glenoid retroversion. The purpose of this study was to assess if glenoid retroversion varies significantly at different glenoid heights in Walch B2 and B3 glenoids. MATERIALS AND METHODS/METHODS:Patients with B2 and B3 glenoid types were included following retrospective review of 386 consecutive CT shoulder studies performed for arthroplasty preoperative planning. True axial CT reconstructions were created using a validated technique. Two readers independently measured the glenoid retroversion angles according to the Friedman method using the "intermediate" glenoid at three glenoid heights: 75% (upper), 50% (equator), and 25% (lower). The variances between the three levels for a given patient were calculated. RESULTS:Twenty-nine B2 and 8 B3 glenoid types were included. There was no significant difference in variance of glenoid version among the three levels in B2 or B3 groups. The mean variance in retroversion degree between equator-lower, upper-equator, and upper-lower glenoid was - 0.4, 0.3, and - 0.2 for B2; and - 0.2, 1.9, and 1.9 for B3 glenoid, respectively. The level of inter-reader agreement was fair to good for variance at equator-lower, and good to excellent for upper-equator and upper-lower glenoid. CONCLUSIONS:Glenoid version can be accurately measured at any level between 25 and 75% of glenoid height for Walch B2 and B3. We recommend that the glenoid equator be used as the reference to assure consistent and reliable version measurements in this group of patients.

RATIONALE AND OBJECTIVES/OBJECTIVE:To explore downstream costs associated with incidental pulmonary nodules detected on CT. MATERIALS AND METHODS/METHODS:The cohort comprised 200 patients with an incidental pulmonary nodule on chest CT. Downstream events (chest CT, PET/CT, office visits, percutaneous biopsy, and wedge resection) were identified from the electronic medical record. The 2017 Fleischner Society Guidelines were used to classify radiologists' recommendations and ordering physician management for the nodules. Downstream costs for nodule management were estimated from national Medicare rates, and average costs were determined. RESULTS:Average downstream cost per nodule was $393. Costs were greater when ordering physicians over-managed relative to radiologist recommendations ($940) vs. when adherent ($637) or under-managing ($166) relative to radiologists recommendations. Costs were also greater when ordering physicians over-managed relative to Fleischner Society guidelines ($860) vs. when under-managing ($208) or adherent ($292) to guidelines. Costs did not vary significantly based on whether or not radiologists recommended follow-up imaging ($167-$397), nor whether radiologists were adherent or under- or over-recommended relative to Fleischner Society guidelines ($313-$444). Costs were also higher in older patients, patients with a smoking history, and larger nodules. Five nodules underwent wedge resection and diagnosed as malignancies. No patient demonstrated recurrence or metastasis. Average cost per diagnosed malignancy was $3090. CONCLUSION/CONCLUSIONS:Downstream costs for incidental pulmonary nodules are highly variable and particularly high when ordering physicians over-manage relative to radiologist recommendations and Fleischner Society guidelines. To reduce unnecessary utilization and cost from over-management, radiologists may need to assume a greater role in partnering with ordering physicians to ensure appropriate, guideline-adherent, and follow-up testing.

OBJECTIVE:To evaluate change in patient-reported outcomes following image-guided intra-articular therapeutic steroid hip injections for pain and assess correlations of outcomes with patient- and injection-specific factors. MATERIALS AND METHODS/METHODS:We retrospectively reviewed consecutive patients treated for hip pain who completed outcomes assessments from October 2011 to September 2017 at an outpatient orthopedic surgery clinic. Only patients with radiographic hip osteoarthritis (Tönnis grade ≥ 1) who underwent steroid hip injections were included. Outcomes assessments included EuroQol-5 domain (EQ5D), EQ5D-visual analog scale (VAS), and hip disability and osteoarthritis outcome score (HOOS), obtained before and within 1-6 months post-injection. Among 113 patients who completed surveys, the mean age was 59 years (±13.7 years), including 77 women (68%) and 36 men (32%). Time to repeat injection or arthroplasty was recorded. Exact Wilcoxon signed rank test assessed score differences and Spearman correlation, Kruskal-Wallis, and Mann-Whitney tests assessed correlations. RESULTS:Of 113 patients, 34 had outcomes measured at <8 weeks and 79 at ≥8 weeks. There was no significant change among any of the patients, short- or long-term follow-up subgroups in EQ5D (p = 0.450, 0.770, 0.493 respectively), EQ5D-VAS (p = 0.581, 0.915, 0.455), average-HOOS (p = 0.478, 0.696, 0.443) or total-HOOS (p = 0.380, 0.517, 0.423) scores. Forty-nine patients underwent hip arthroplasty within 1 year. Positive correlation was found between days from injection to surgery and change in EQ5D (r = 0.29, p = 0.025), average-HOOS (r = 0.33, p = 0.019), and total-HOOS (r = 0.37, p = 0.008). CONCLUSION/CONCLUSIONS:We demonstrated no significant change in patient-reported outcomes measured at short- and long-term intervals up to 6 months after therapeutic steroid hip injections.

OBJECTIVE:The purpose of this study is to determine the most accurate imaging techniques to measure glenoid bone loss in anterior glenohumeral instability through a systematic review of existing literature. MATERIALS AND METHODS/METHODS:We performed a comprehensive literature search of five databases for original research measuring glenoid bone loss at radiography, CT, or MRI, using prospective or retrospective cohort, case-control, or cadaveric study designs up to January 2018. The Quality Assessment of Diagnostic Accuracy Studies-2 tool aided qualitative assessment of the methods. Data extraction included results, index test interobserver agreement, and accuracy analysis. RESULTS:Twenty-seven studies (evaluating 1425 shoulders) met inclusion criteria after full-text review by two independent readers. Glenoid bone loss was assessed, comparing several index tests to nonimaging (n = 18 studies) and imaging (n = 11) reference standards. Compared with arthroscopic or cadaveric measurements, 2D CT was accurate in six of seven studies (86%), 3D CT was accurate in eight of 10 studies (80%), 2D MRI was accurate in five of seven studies (71%), 3D MRI was accurate in four of four studies (100%), and radiographs were accurate in zero of four studies (0%). Best-fit circle methods (glenoid width or Pico surface area) were the most common and both were accurate (86-90% and 75-100%, respectively) using CT and MRI. Studies had good external validity (78%). Most risk for bias arose from patient selection and reference standards. Only two studies reported sensitivity and specificity, both comparing CT to arthroscopy using different bone loss thresholds (20% and 25%). CONCLUSION/CONCLUSIONS:CT and MRI (2D or 3D) accurately measure glenoid bone loss in anterior shoulder instability, but radiographs do not. Best-fit circle measurement techniques are reliable and accurate. Current literature about glenoid bone loss is heterogeneous, and future studies should focus on diagnosis of clinically relevant glenoid bone loss.

Purpose: To present an automatic humeral head and glenoid segmentation method based on two-dimensional deep convolutional neural networks (CNNs).
Material(s) and Method(s): The study received institutional review board approval. A retrospective dataset of volumetric structural MR images of the shoulder from 100 subjects, including 73 normal cases and 27 cases with a Hill-Sachs lesion and/or anterior glenoid bone loss in the setting of anterior shoulder instability, were manually segmented by experts. A 2D CNN architecture was trained with multiple initial feature maps and layers. Its segmentation performance was then tested against the gold standard of manual segmentation using four-fold cross-validation. The time needed to manually segment each shoulder MRI was documented for each case.
Result(s): Automatic segmentation of the humeral head achieved a mean average precision for object detection of 0.99, a dice similarity score of 0.95, a segmentation precision of 0.95, and recall of 0.95. The Hausdorff distance was 26.9mm, the mean square distance of 0.5mm, and the residual mean square distance of 1.5mm. For the glenoid, automatic segmentation achieved a mean average precision for object detection of 0.92, a dice similarity score of 0.86, a segmentation precision of 0.88, and recall of 0.86. The Hausdorff distance was 20.7mm, themean square distance of 0.8mm, and the residual mean square distance of 1.8mm. On average, the time for manual segmentation ranged between 90 to 120 minutes per imaging study.
Conclusion(s): Using CNNs, we were able to accurately segment the humeral head and glenoid on MRI. Our results serve as an important initial step towards the automatic diagnosis and quantification of Hill-Sachs lesions and glenoid bone loss and determination of on/off track status. This, in turn, has the potential to provide consistently accurate imaging information that can be used to guide the selection of the most appropriate initial treatment for the anterior shoulder instability patient population

Purpose: To explore variation in downstream costs associated with cartilage lesions incidentally detected on radiographs. Materials andMethods: The cohort was composed of 120 patients with incidental, not previously diagnosed, cartilage lesions seen on appendicular plain radiographs. The population was divided into three subgroups based on the interpreting radiologist's description: enchondroma, lowgrade cartilage lesion, and chondrosarcoma. Downstream events (follow-up imaging, office visits, biopsy, tumor resection) associated with the lesions were identified from the electronic medical record. American College of Radiology (ACR) Appropriateness Criteria were used to classify radiologists' recommendations. NationalMedicare rates were used to estimate costs of downstream events. Average cost per lesion was stratified, and cost ratios were computed among subgroups.
Result(s): Average downstream cost per lesion was $75.56. Costs were 4.6 times greater in patients under the age of 65 than over. Costs were 13.2 and 13.7 times higher when radiologists characterized lesions as chondrosarcoma versus low-grade cartilage lesion and enchondroma, respectively. There was no statistically significant difference in costs between the subgroups when accounting for size and location of lesions. Compared to when follow-up imaging was neither recommended nor obtained, costs rose from $0 to $26.03 per patient when follow-up imaging was recommended and obtained, and $62.21 per patient when followup imaging was obtained despite not being recommended. Costs rose from $0 to $14.83 per patient when radiologists' recommendations for follow-up were adherent to the ACR guidelines for management of incidental bone lesions. Costs were 2.3 times greater when ordering physicians overmanaged compared with radiologists' recommendations. No malignancy was pathologically proven in the cohort.
Conclusion(s): Costs for incidental cartilage lesions vary. Size and location of lesions do not have a significant effect on downstream costs; however, radiologists' characterization and recommendation have an impact. Therefore, it is imperative that radiologists accurately characterize such lesions and recommendations reflect the best value for patient care

Purpose: Preoperative cartilage loss is a predictor of poor outcomes after arthroscopic partial meniscectomy (APM). Previous studies have used time-intensive MRI grading systems, such as MOAKS (MRI OsteoArthritis Knee Score), which are not amenable for routine clinical use. This study's purpose was to test whether cartilage loss graded using MOAKS provides better prediction of outcomes than a simpler clinically used grading system.
Material(s) and Method(s): 80 cases were selected meeting the following criteria: 1. Preoperative knee MRI performed within 6 months of APM surgery 2. Outcomes measured at the time of surgery and 1 year after surgery. Surgical failure was defined as a less than 10 point improvement in the Knee Osteoarthritis Pain Score (KOOSpain). Cases were independently evaluated by 2 musculoskeletal (MSK) radiologists and 1 radiology fellow using MOAKS and a modified Outerbridge grading system used clinically. Accuracy of each system in discriminating success and failure was estimated using area under the ROC (AUC) with 95% confidence intervals (CI).
Result(s): 78 patients (38 females) with mean age of 56.6 years (range of 45-77) were studied. 32 patients (41%) were surgical failures. At least Grade 2 (< 50% cartilage thickness loss) ranged from 8% (lateral tibial plateau) to 26% (medial femoral condyle) of the observations. AUC values of the clinical grading system (range 0.585 - 0.625) were very similar to MOAKS (range 0.553 to 0.667) for all cartilage surfaces and non-inferior to MOAKS in the medial femoral condyle (p = 0.015) and trochlea (p =0.031). The lateral femoral condyle was the only surface where MOAKS (0.667) was significantly higher than the clinical grading system (0.614).
Conclusion(s): Cartilage loss graded usingMOAKS and a simpler clinically used system have similar ability in predicting outcomes after APM. This suggests that it is feasible to use routine clinical grading of cartilage to develop models to predict outcomes after APM

OBJECTIVE:To determine if hip 3D-MR imaging can be used to accurately demonstrate femoral and acetabular morphology in the evaluation of patients with femoroacetabular impingement. MATERIALS AND METHODS/METHODS:We performed a retrospective review at our institution of 17 consecutive patients (19 hips) with suspected femoroacetabular impingement who had both 3D-CT and 3D-MRI performed of the same hip. Two fellowship-trained musculoskeletal radiologists reviewed the imaging for the presence and location of cam deformity, anterior-inferior iliac spine variant, lateral center-edge angle, and neck-shaft angle. Findings on 3D-CT were considered the reference standard. The amount of radiation that was spared following introduction of 3D-MRI was also assessed. RESULTS:All 17 patients suspected of FAI had evidence for cam deformity on 3D-CT. There was 100% agreement for diagnosis (19 out of 19) and location (19 out of 19) of cam deformity when comparing 3D-MRI with 3D-CT. There were 3 type I and 16 type II anterior-inferior iliac spine variants on 3D-CT imaging with 89.5% (17 out of 19) agreement for the anterior-inferior iliac spine characterization between 3D-MRI and 3D-CT. There was 64.7% agreement when comparing the neck-shaft angle (11 out of 17) and LCEA (11 out of 17) measurements. The use of 3D-MRI spared each patient an average radiation effective dose of 3.09 mSV for a total reduction of 479 mSV over a 4-year period. CONCLUSION/CONCLUSIONS:3D-MR imaging can be used to accurately diagnose and quantify the typical osseous pathological condition in femoroacetabular impingement and has the potential to eliminate the need for 3D-CT imaging and its associated radiation exposure, and the cost for this predominantly young group of patients.

Purpose: To better understand alterations in repaired supraspinatus tendons using a multimodality approach including MRI, assessment of tendon vascularity by power Doppler (PD), and tendon mechanical properties using shear wave elastography (SWE). To investigate whether SWE and PD can provide quantitative assessment of tendon healing following rotator cuff repair.
Material(s) and Method(s): This HIPAA compliant prospective study was approved by the institutional review board with informed consent. Between 9/2013 and 6/2016, twelve patients (7 males, 5 females; mean age 61 years) with unilateral full-thickness supraspinatus tendon tears underwent MRI and ultrasound pre-operatively, 3-months and 6-months post-surgery. The supraspinatus tendon MRI signal intensity, PD and SWE properties were measured. Repaired and asymptomatic shoulders were compared over time within and between modalities.
Result(s): No significant association was seen between mean SWE and MRI signal intensity (non-insertional portion -0.25, p=0.467, insertional portion -0.18, p=0.593), or between PD and MRI signal intensity (non-insertional portion -0.19, p=0.599, insertional portion 0.22, p=0.533) within the supraspinatus tendon. MRI signal intensity and PD within the supraspinatus tendon, both increased and then decreased postoperatively. Shear wave velocities increased throughout the postoperative period in the tendon footprint, while increasing and then decreasing in the distal tendon.
Conclusion(s): MRI and ultrasound parameters did not achieve statistically significant correlation; however, their respective trend behavior suggests that a temporal relationship exists between modali ties. We postul a te that a more detai l ed multiparametric imaging approach and/or comparison with a more selective MR measure, such as T2* values, may be required to evaluate rotator cuff repair