Glenoid Radius of Curvature and Humeral Head Volume Are Associated With Postoperative Dislocation After Arthroscopic Bankart Repair.

PURPOSE: To measure bony morphologic parameters and identify their association with arthroscopic Bankart repair failure. METHODS: This was a retrospective comparative study. The inclusion criteria were primary arthroscopic Bankart repair, no prior shoulder surgery, traumatic cause, and had a Bankart (soft tissue and bony) lesion evident on magnetic resonance imaging (MRI). The exclusion criteria were posterior labral pathology, multidirectional instability, connective tissue disorder, rotator cuff pathology, and those who underwent concomitant shoulder procedures. Patients who had a postoperative redislocation (unstable group) were compared with matched patients who did not (stable group). Data were obtained by chart review and from preoperative MRI. Comparisons were made using the Student t test, Fisher exact test, or χ2 test. Statistical significance was defined as P < .05. Inter-rater reliability was measured between reviewers. RESULTS: A total of 45 patients experienced a postoperative dislocation and were matched to 90 patients without a postoperative dislocation. There were no differences in demographic and radiographic variables. The radius of curvature (ROC) of the glenoid was larger (shallower) in the unstable group (23.6 mm vs 22.6 mm, P = .05). The humeral head volume (HHV) trended higher in the unstable group (68.9 mL vs 62.9 mL, P = .06). The glenoid volume was not significantly different. A greater percentage of patients with a glenoid ROC of 24.5 mm or greater (62.1% vs 26.4%, P = .0003) and an HHV of 80 mm3 or greater (60.8% vs 28.9%, P = .003) experienced a redislocation compared with patients without these factors. Patients with a glenoid ROC of 24.5 mm or more and an HHV of 80 mm3 or more had greater than 4 times the odds of redislocation (odds ratio, 4.56; 95% confidence interval, 1.44-14.43; P = .0098). Strong inter-rater reliability was found for the HHV, glenoid volume, glenoid ROC, and humeral head ROC measurements (r = 0.94, r = 0.88, r = 0.89, and r = 0.95, respectively). CONCLUSIONS: This study shows that large ROC (shallow) glenoids in conjunction with large humeral heads may predispose patients to failure after arthroscopic Bankart repair. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

Labral Morphology and Number of Preoperative Dislocations Are Associated With Recurrent Instability After Arthroscopic Bankart Repair.

PURPOSE: To develop a method to measure capsule and labral volume on preoperative magnetic resonance imaging to predict surgical failure after primary Bankart repair. METHODS: A retrospective case-control study was conducted on patients undergoing primary anterior arthroscopic shoulder stabilization. Surgical failure was defined as a recurrent dislocation event. Cases were matched to controls based on age and sex in a 1:2 ratio. Preoperative magnetic resonance (MR) arthrograms were analyzed by 2 trained reviewers using Vitrea software to measure labral and capsular volume with a 3-dimensional model. Labral size was also qualitatively measured on axial images. A "diffusely small" labrum was defined as labral height less than the width of the glenoid tidemark cartilage. RESULTS: Of the 289 patients who had an arthroscopic Bankart repair from 2006 to 2015, 33 who had a postoperative dislocation met the inclusion criteria and were matched to 62 control patients who did not. There was no difference between groups with regard to age (P = .88), sex (P = .82), contact sport participation (P = .79), proportion of overhead athletes (P = .33), proportion of throwers (P = 1), surgical positioning in lateral decubitus (P = .18), or number of repair anchors used (P = .91). The average number of preoperative dislocations was significantly higher in the failure group (3.2 vs. 2.0, P < .0001). In patients with normal labrum morphology, the odds of having surgical failure increased by 26% for a 1-unit increase in the number of prior dislocations (odds ratio [OR] 1.26, 95% confidence interval [CI] 1.02 to 1.55). The case and control groups had similar labral and capsular volume as measured in Vitrea. The failure group had a significantly higher proportion of patients with a diffusely small labral morphology (47% vs. 17%, P = .03). Controlling for number of preoperative dislocations, the odds of having a diffusely small labral morphology was 3.2 times more likely in the case group than the control group (95% CI 1.259 to 8.188). Interrater reliability between 2 independent reviewers was excellent for measurement of capsule volume (r = 0.91) and good for measurement of labral volume (r = 0.74). CONCLUSIONS: This study presents a novel method of measuring labral and capsule volume with high interrater reliability. An increased number of recurrent dislocations prior to primary Bankart repair was associated with increased odds of recurrent instability after surgery. The OR for failure also increased with increasing number of preoperative dislocations. Diffusely small labral morphology was associated with having a postoperative redislocation. LEVEL OF EVIDENCE: III (case-control study).

Subchondral insufficiency fracture of the knee: A recognizable associated soft tissue edema pattern and a similar distribution among men and women.

OBJECTIVE: Primary: to describe the presence and pattern of soft tissue edema in subchondral insufficiency fractures of the knee (SIFK). Secondary: to investigate the gender distribution and identify factors associated with disease progression. METHODS: MR images of 74 SIFKs in 74 patients were retrospectively reviewed for soft tissue edema presence and location, meniscal tears and extrusion and synovitis. The clinical records were reviewed for age, gender, and BMI. Follow up examinations were reviewed to assess for progression. Data were analyzed for gender distribution and for association between each imaging finding as a predictor of SIFK location and progression. RESULTS: Soft tissue edema was present in 89% (66/74) of SIFK. It was located around the MCL in 78% (58/74), posterior to and abutting on the posterior distal femur in 68% (50/74), around to the tibia in only 18% (13/74), but when present it strongly predicted the presence of a medial tibial plateau SIFK (p=5.6×10^-12). Edema extended to the vastus medialis fascia in 51% (38/74) and vastus lateralis fascia in 24% (18/74). Gender distribution was 1:1 (males=38, females=36), most common in the 6th decade (29/74, 39%). Lesion progression showed a trend towards being more common in females (8/9, 89%) compared to males (9/16, 56%), and in patients with meniscal extrusion (≥3mm) (13/14, 93%) compared to those with no extrusion (2/7, 29%). CONCLUSION: A recognizable soft tissue edema pattern is seen in SIFK and may have an important role in early diagnosis. Also, SIFK may affect equally males and females in the 6th decade and may progress more in females. Meniscal extrusion may predispose to disease progression.

Correlation Between Cam-Type Femoroacetabular Impingement and Radiographic Osteitis Pubis.

A mechanistic link has been suggested between cam-type femoroacetabular impingement and increased stress on the symphysis pubis. This retrospective study was conducted to determine whether there is an increased prevalence of osteitis pubis, as evidenced by imaging, in patients with femoroacetabular impingement compared with age-matched control subjects. Search of a radiologic database of a large academic health institution for all patients with cam-type femoroacetabular impingement diagnosed by magnetic resonance imaging or magnetic resonance arthrogram between January 2000 and October 2013 identified 46 cases. Two radiologists reviewed these cases independently and confirmed the presence of femoroacetabular impingement based on alpha angle and other characteristics of cam morphology. The imaging studies were further evaluated for characteristics of osteitis pubis, with severity graded from minimal to severe on a 4-point Likert scale. A control group composed of age-matched subjects without diagnosed femoroacetabular impingement was also evaluated for osteitis pubis. A statistically significant increase in the prevalence of osteitis pubis was found in patients with femoroacetabular impingement compared with age-matched control subjects, with a prevalence of 43.48% in the femoroacetabular impingement group compared with 12.77% in the control group (P=.0012). On the 4-point Likert scale, the average severity of osteitis pubis in the group with femoroacetabular impingement was 1.5 (minimal to mild) compared with 0.53 (no osteitis pubis to minimal findings) in the control population. This significant increase in osteitis pubis in patients with femoroacetabular impingement supports the clinical link between these 2 processes. [Orthopedics. 2016; 39(3):e417-e422.].

Molecular imaging: an innovative force in musculoskeletal radiology.

OBJECTIVE: A review of the innovative role molecular imaging plays in musculoskeletal radiology is provided. Musculoskeletal molecular imaging is under development in four key areas: imaging the activity of osteoblasts and osteoclasts, imaging of molecular and cellular biomarkers of arthritic joint destruction, cellular imaging of osteomyelitis, and imaging generators of musculoskeletal pain. CONCLUSION: Together, these applications suggest that next-generation musculoskeletal radiology will facilitate quantitative visualization of molecular and cellular biomarkers, an advancement that appeared futuristic just a decade ago.

The adoption of low-osmolar contrast agents in the United States: historical analysis of health policy and clinical practice.

OBJECTIVE: In this historical analysis of low- and high-osmolar contrast agents, we outline the reasons for the price depreciation, speculate on motivation for universal adoption by many radiologists despite suboptimal reimbursement, and cast light on important shortcomings of economic analyses in the realm of health policy. CONCLUSION: Early economic analyses regarding low-osmolar contrast agents concluded that universal adoption was not cost-effective. Over time, the price differential between low- and high-osmolar agents narrowed, yet reimbursement patterns lagged behind the narrowing price differential.

Intraluminal migration of surgical drains after transhiatal esophagogastrectomy: radiographic findings and clinical relevance.

OBJECTIVE: The objectives of our study were to review our experience with a group of patients in whom contrast examinations after transhiatal esophagogastrectomy and gastric pull-through revealed intraluminal migration of a surgical drain and to describe the radiographic appearance and clinical relevance of this phenomenon. CONCLUSION: Our findings indicate that intraluminal migration of a surgical drain after transhiatal esophagogastrectomy is an infrequent but serious phenomenon that hinders or prevents healing of an anastomotic leak. Radiologists should be aware of this phenomenon and should be able to recognize the findings of an intraluminal drain on contrast examinations. When such drains are identified, we believe that they should be promptly withdrawn or removed to facilitate healing of anastomotic leaks.

Embolization of a Recurrent Type 2 Endoleak Using the Liquid Embolic n-Butyl Cyanoacrylate.

Endovascular aneurysm repair (EVAR) has become an accepted alternative to open aortic aneurysm repair. Endoleaks are one of the most common complications of EVAR and can result in aneurysm enlargement and rupture. When embolization of type 2 endoleaks is needed, a transarterial or translumbar approach may be used. Metal coils are often utilized, but liquid agents have also been used for embolization. This case report involves endoleak embolization using metallic coils along with the liquid embolic agent n-butyl cyanoacrylate (n-BCA).