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.

Tunnel widening following anterior cruciate ligament reconstruction using hamstring autograft: a comparison between double cross-pin and suspensory graft fixation.

Femoral and tibial tunnel widening following ACL reconstruction using hamstring autograft has been described. Greater tunnel widening has been reported with suspensory fixation systems. We hypothesized that greater tunnel widening will be observed in patients whose hamstring autograft was fixated using a cortical, suspensory system, compared to double cross-pin fixation on the femur. We performed clinical and radiographic evaluation on 46 patients at minimum 2 years after primary ACL reconstruction. We measured subjective and objective outcomes including KT-1000 and AP, lateral radiographs. A musculoskeletal radiologist, independent of the surgical team, measured tunnel width, while correcting for magnification, at the widest point and at 1 cm away from tibial and femoral tunnel apertures. Patients in the suspensory graft fixation group exhibited significantly greater absolute change and greater percent change in femoral tunnel diameter compared to patients with double cross-pin fixation (P

Intra-articular migration of a sutureless arthroscopic rotator cuff fixation device.

Rotator cuff tears are a common orthopaedic condition. Recent new advances in arthroscopic equipment and devices has allowed many rotator cuff tears to be repaired arthroscopically. Some of these newer devices allow sutureless repair of rotator cuff tears. We report a case of failure in intra-articular migration of such a fixation device. Displacement of the device was noted 4 months after surgery on magnetic resonance arthography. The device was removed arthroscopically with no long-term sequelae. Nevertheless, it is important to recognize that these devices have the potential for intra-articular migration. Due diligence is required in placing these devices. As with all arthroscopic procedures, there appears to be a learning curve associated with the use of sutureless rotator cuff repair fixation devices.

The knee: bone marrow abnormalities.

MRI is clearly the imaging modality of choice for detecting and exploring joint, osseous, and soft tissue injuries in the lower extremity and throughout the musculoskeletal system. Its ability to detect and differentiate the various forms of marrow pathology is unrivaled, and as such it should be obtained early in the work-up of a patient with a suspected marrow abnormality. Additionally, the radiologist must be familiar with the MRI appearances of normal marrow and the most common types of marrow pathology if its diagnostic power is to be fully realized.