Radiographic Appearance of Transforaminal Lumbar Interbody Fusion Performed With and Without Recombinant Human Morphogenetic Protein-2.

OBJECTIVE: The purpose of this study is to determine whether recombinant human morphogenetic protein-2 (rhBMP-2) alters the findings on routine radiographs performed after transforaminal lumbar interbody fusion (TLIF). MATERIALS AND METHODS: A retrospective review of 256 TLIF procedures in 200 patients was performed over a 4-year period. The rhBMP-2 group included 204 TLIFs in 160 patients, and the control group included 52 TLIFs in 40 patients. Two musculoskeletal radiologists reviewed the postoperative radiographs for endplate resorption, resorption resolution, new bone formation, bridging bone, and allograft migration. Statistical analysis was performed using logistic regression. RESULTS: The median age was 53 years in the rhBMP-2 group and 54 years in the control group (p = 0.182). The groups were similar with regard to sex (p = 0.517), single or multilevel TLIF (p = 0.921), specific TLIF levels (p = 0.53), and median radiographic follow-up (373 vs 366 days; p = 0.34). Findings that were more common in the rhBMP-2 group than in the control group included endplate resorption (38% [78/204] vs 12% [6/52]; odds ratio [OR], 4.67; 95% CI, 1.99-12.54; p < 0.001), resorption resolution (59% [46/78] vs 0% [0/6]; OR, 8.09; 95% CI, 1.41 to ∞; p = 0.022), new bone formation (84% [171/204] vs 67% [35/52]; OR, 2.51; 95% CI, 1.24-4.99; p = 0.011), bridging bone (55% [112/204] vs 31% [16/52]; OR, 2.73; 95% CI, 1.43-5.34; p = 0.002), and allograft migration (17% [35/204] vs 2% [1/52]; OR, 6.30; 95% CI, 0.91-151.41; p = 0.065). CONCLUSION: A statistically significant higher frequency of endplate resorption, new bone formation, and bone bridging is present in TLIF augmented by rhBMP-2 compared with TLIF performed without rhBMP-2. Endplate resorption resolves without treatment in most cases after rhBMP-2 use.

Prospective Evaluation of Agreement and Accuracy in the Diagnosis of Meniscal Tears: MR Arthrography a Short Time After Injection Versus CT Arthrography After a Moderate Delay.

OBJECTIVE: The purpose of this study was to compare the performance of direct CT arthrography performed after a moderate injection delay with that of MR arthrography performed soon after injection in the diagnosis of meniscal tears. SUBJECTS AND METHODS: Twenty-five patients underwent direct MR arthrography followed by same-day CT arthrography of the knee. Two blinded musculoskeletal radiologists independently reviewed the MR and CT arthrographic images for the presence of medial or lateral meniscal tears in the anterior horn, body, and posterior horn. Their readings were compared with a reference standard reading, which was based on post-MRI arthroscopic findings (n = 11) or the consensus opinion of two other musculoskeletal radiologists who simultaneously reviewed the paired CT and MR arthrographic examinations using all available clinical, surgical, and imaging information. The individual and combined radiologist agreements with the reference standard were calculated for each modality. RESULTS: Interreader agreement was 91% for MR arthrography and 85% for CT arthrography. The overall combined radiologist agreement with the reference standard was 91% for MR arthrography and 86% for CT arthrography (p = 0.03). For the two readers, the overall accuracy rates for diagnosing a meniscal tear were 82% and 88% with MR arthrography and 74% and 76% with CT arthrography. Only 50% (3/6) of surgically proven tears imbibed gadolinium. CONCLUSION: Although MR arthrography performed soon after the contrast injection had higher interreader agreement and greater accuracy, CT arthrography performed after a mean postinjection delay of 100 minutes was moderately accurate in the diagnosis of meniscal tears and can be used as an alternative procedure when MR arthrography cannot be completed.

An alternative injection technique for performing MR ankle arthrography: the lateral mortise approach.

OBJECTIVES: This study evaluates whether the recently described lateral mortise (LM) approach to therapeutic ankle injections can also be used to inject the ankle prior to magnetic resonance arthrography (MRA) without impairing the evaluation of the anterior talofibular ligament (ATFL). MATERIALS AND METHODS: An IRB-approved, retrospective review of ankle MRAs performed using the LM approach between April 2009 and April 2011 was conducted. The MRAs were independently evaluated by three musculoskeletal radiologists for: ATFL assessment (well assessed, limited or unable to assess), amount of fluid in the anterolateral soft tissues (none to large), and capsular distention (underdistended to overdistended). Patient age, gender, fluoroscopy time, injection location, degree of ankle arthritis, and ankle joint narrowing on radiographs were recorded. Statistical analysis was performed using exact binomial confidence limits. RESULTS: Fifteen MRAs were successfully performed on 13 patients (mean age: 27 years, 11 male, 2 female). Mean fluoroscopic time was 39 s (range 9­108) and mean volume injected was 7 mL (range 5­9 mL). The ATFL was well assessed on all MRAs. A moderate to large amount of fluid was noted in the anterolateral soft tissues on 5 out of 15 MRAs. No ankle joints were underdistended, but 3 out of 15 were overdistended. CONCLUSION: Since the ATFL is inferior to the location used for the LM injection, the interpretation of the ankle MRA, specifically ATFL evaluation, was not compromised in any patient. Therefore, the LM approach can be used as an alternative to the anteromedial approach for ankle MRA without sacrificing diagnostic quality.

MRI of transforaminal lumbar interbody fusion: imaging appearance with and without the use of human recombinant bone morphogenetic protein-2 (rhBMP-2).

PURPOSE: To describe the vertebral endplate and intervertebral disc space MRI appearance following TLIF, with and without the use of rhBMP-2, and to determine if the appearance is concerning for discitis/osteomyelitis. MATERIALS AND METHODS: After institutional review board approval, 116 TLIF assessments performed on 75 patients with rhBMP-2 were retrospectively and independently reviewed by five radiologists and compared to 73 TLIF assessments performed on 45 patients without rhBMP-2. MRIs were evaluated for endplate signal, disc space enhancement, disc space fluid, and abnormal paraspinal soft tissue. Endplate edema-like signal was reported when T1-weighted hypointensity, T2-weighted hyperintensity, and endplate enhancement were present. Subjective concern for discitis/osteomyelitis on MRI was graded on a five-point scale. Generalized estimating equation binomial regression model analysis was performed with findings correlated with rhBMP-2 use, TLIF level, graft type, and days between TLIF and MRI. RESULTS: The rhBMP-2 group demonstrated endplate edema-like signal (OR 5.66; 95% CI [1.58, 20.24], p = 0.008) and disc space enhancement (OR 2.40; 95% CI [1.20, 4.80], p = 0.013) more often after adjusting for the TLIF level, graft type, and the number of days following TLIF. Both groups had a similar temporal distribution for endplate edema-like signal but disc space enhancement peaked earlier in the rhBMP-2 group. Disc space fluid was only present in the rhBMP-2 group. Neither group demonstrated abnormal paraspinal soft tissue and discitis/osteomyelitis was not considered likely in any patient. CONCLUSIONS: Endplate edema-like signal and disc space enhancement were significantly more frequent and disc space enhancement developed more rapidly following TLIF when rhBMP-2 was utilized. The concern for discitis/osteomyelitis was similar and minimal in both groups.

Lateral mortise approach for therapeutic ankle injection: an alternative to the anteromedial approach.

OBJECTIVE: The purpose of this study was to evaluate the lateral mortise approach for performing therapeutic ankle injections. MATERIALS AND METHODS: Fluoroscopically guided ankle joint injections performed from November 2009 through June 2011 using the lateral ankle mortise approach were retrospectively reviewed. Data recorded included age, sex, fluoroscopic time, person performing the procedure, injection location, and preprocedure and postprocedure pain levels. Radiographs were reviewed for arthritis on a modified Kellgren-Lawrence scale, and the degree of anterior tibiotalar and lateral mortise narrowing was graded from none to severe. Univariate and multivariate statistical analyses were performed. RESULTS: Fifty-three injections were performed on 46 patients (mean age, 50.2 years; mean fluoroscopic time, 44.3 ± 47.3 seconds). Fifty injections in 44 patients were successful with the lateral mortise approach. The degrees of arthritis and anterior tibiotalar joint narrowing were moderate in 22.6% and 20.8% of cases and severe in 39.6% and 32.1% of cases. Lateral mortise narrowing was moderate in 9.4% and severe in 1.9% of cases. Average pre-procedure and postprocedure pain levels were 5.3/10 ± 2.4/10 and 1.7/10 ± 2.3/10. Multivariate analysis showed that increased fluoroscopic time was associated with moderate to severe lateral mortise narrowing (p = 0.011) but that arthritis score (p = 0.811) and degree of anterior tibiotalar joint narrowing (p = 0.416) were not. Pain reduction was associated with a higher preinjection pain score (p ≤ 0.001). CONCLUSION: The lateral mortise approach is an effective alternative to the anterior medial approach for performing therapeutic ankle injections. It is especially useful when moderate to severe ankle arthritis or anterior tibiotalar joint narrowing is present.

Shoulder MR arthrography: intraarticular anesthetic reduces periprocedural pain and major motion artifacts but does not decrease imaging time.

PURPOSE: To prospectively determine whether the addition of an intraarticular anesthetic to the magnetic resonance (MR) arthrography solution has an effect on periprocedural pain, motion artifacts, and imaging time. MATERIALS AND METHODS: This study was approved by the institutional review board, and written informed consent was obtained from all patients. From September 2009 to March 2010, 127 patients, most imaged for shoulder pain, were randomized into two groups. The first group (group A, 63 patients) received intraarticular injection of gadopentetate dimeglumine, ropivacaine 0.5%, and normal saline in a ratio of 1:100:100. The second group (group B, 64 patients) received intraarticular injection of gadopentetate dimeglumine and normal saline in a ratio of 1:200. Pain was assessed before and after injection and immediately after 1.5-T MR imaging and rated on a scale of 0 to 10. Motion artifact was assessed by two musculoskeletal radiologists and two fellows by using a scale of 0 to 3 (0=no artifact, 1=artifact present but not affecting diagnostic image quality, 2=artifact present and diminishing diagnostic image quality, and 3=artifact present and rendering image nondiagnostic). MR imaging time and examinations with repeated sequences were recorded. Wilcoxon rank sum, analysis of covariance, and permutation data analyses were performed. RESULTS: The mean pain levels before injection, after injection, and after MR imaging were 3.5, 2.3, and 2.5, respectively, for group A and 3.6, 3.1, and 3.2 for group B. After adjusting for age, sex, and preinjection pain level, the mean differences in pre- and postinjection pain and preinjection pain and post-MR imaging pain between the two groups were -0.9 (P=.017) and -0.8 (P=.056), respectively. No significant difference in mean total MR imaging time or number of patients with repeat sequences was noted. Radiologists 1 and 2 recorded grade 2 or 3 motion in six and five patients, respectively, in group A and 15 and 14 patients, respectively, in group B (P=.047 and .048, respectively). Radiologists 3 and 4 recorded grade 2 or 3 motion in 13 and 23 patients, respectively, in group A and 23 and 33 patients, respectively, in group B (P=.093 and .110, respectively). CONCLUSION: The use of an intraarticular anesthetic significantly reduces periprocedural pain and major motion artifacts associated with MR shoulder arthrography; however, total MR imaging time is not reduced.

Overhead throwing injuries of the shoulder and elbow.

Injuries to the shoulder and elbow are common in athletes involved in sporting activities that require overhead motion of the arm. An understanding of the forces involved in the throwing motion, the anatomic structures most at risk, and the magnetic resonance imaging appearances of the most common associated injuries can help to improve diagnostic accuracy when interpreting imaging studies in these patients.

Dexamethasone therapy in neonates treated with extracorporeal membrane oxygenation.

OBJECTIVE: To test the hypothesis that infants who received dexamethasone would have a shorter length of time on extracorporeal membrane oxygenation (ECMO). Study design Infants placed on ECMO for respiratory failure were randomly assigned to receive either dexamethasone for 3 days or placebo. Chest radiographs were scored through the use of a validated standard scoring system to assess lung injury. RESULTS: Thirty infants received dexamethasone and 29 received placebo. The median (25th%, 75th%) duration of time on ECMO was 143.5 (100, 313) hours in the dexamethasone group and 160 (111, 303) hours in the placebo group (not significant). Survival was 80% in the dexamethasone group and 83% in the placebo group. Radiographic lung injury scores (mean+/-SEM) were significantly improved in the dexamethasone group (10.5+/-0.6) versus placebo (12.3+/-0.5) on day 3 of ECMO (P=.013). Hypertension developed in 27 of the 30 infants receiving dexamethasone and 13 of the 29 infants in the placebo group during ECMO (P<.01). CONCLUSIONS: Dexamethasone given during the first 3 days of ECMO results in significant improvement in lung injury scores by day 3 of ECMO but does not significantly decrease the duration of ECMO or improve survival. The preponderance of evidence would not support the use of dexamethasone in this setting.