Role of advanced MRI techniques for sacroiliitis assessment and quantification.

The introduction of MRI was supposed to be a qualitative leap for the evaluation of Sacroiliac Joint (SIJ) in patients with Axial Spondyloarthropathies (AS). In fact, MRI findings such as bone marrow edema around the SIJ has been incorporated into the Assessment in SpondyloArthritis International Society (ASAS criteria). However, in the era of functional imaging, a qualitative approach to SIJ by means of conventional MRI seems insufficient. Advanced MRI sequences, which have successfully been applied in other anatomical areas, are demonstrating their potential utility for a more precise assessment of SIJ. Dixon sequences, T2-mapping, Diffusion Weighted Imaging or DCE-MRI can be properly acquired in the SIJ with promising and robust results. The main advantage of these sequences resides in their capability to provide quantifiable parameters that can be used for diagnosis of AS, surveillance or treatment follow-up. Further studies are needed to determine if these parameters can also be integrated into ASAS criteria for reaching a more precise classification of AS based not only on visual assessment of SIJ but also on measurable data.

Susceptibility Weighted Imaging for evaluation of musculoskeletal lesions.

The presence of blood or calcium in the musculoskeletal (MSK) system may be linked to specific pathological conditions. The ability of MRI for calcium detection is usually limited compared with other techniques such as CT. In a similar manner, the accuracy of MRI for detection and evaluation of hemorrhage in soft tissues is closely linked to the degree of degradation of blood products. Blood and calcium are substances that cause local inhomogeneity of the magnetic field resulting in susceptibility artifacts. To try to evaluate these substances, specific MRI sequences which are highly sensitive to these local magnetic field inhomogeneities such as Susceptibility Weighted Imaging (SWI) have been developed and successfully applied in the Central Nervous System, but scarcely used in MSK. SWI may increase the overall sensitivity of MRI to detect blood and calcium in several clinical scenarios such as degenerative joint disease or bone and soft tissue lesion assessment and discriminate between both compounds, something which is not always possible with conventional MRI approaches. In this paper, physical basis and technical adjustment for SWI acquisition at MSK are detailed reviewing the potential application of SWI in different MSK clinical scenarios.

Outside-in arthroscopic psoas release for anterior iliopsoas impingement after primary total hip arthroplasty.

PURPOSE: 1 of the causes of groin pain after total hip arthroplasty (THA) is impingement of the iliopsoas tendon. The purpose of this study was to present our results with outside-in arthroscopic tenotomy for iliopsoas impingement after THA. METHODS: We retrospectively reviewed 12 patients treated between 2009 and 2016 with a minimum follow-up of 2 years. Anterior acetabular component prominence was measured on a true lateral hip radiograph. A transcapsular tenotomy was performed near the edge of the acetabular component through an outside-in arthroscopic approach. The primary clinical outcomes evaluated were groin pain, assessed with a visual analogue scale (VAS), and the Harris Hip Score (HHS). Secondary outcomes included strength of hip flexion, measured with the Medical Research Council (MRC) scale. RESULTS: All patients had groin pain improvement, though one patient continued to have moderate pain. The mean VAS score was significantly lower postoperatively (1.08) than preoperatively (6.2) (p < 0.001). The mean HHS improved from 58.8 (range, 37-76) to 86.1 (range, 59-98) (p = 0.001). The average postoperative MRC Scale was 4.58. The mean anterior prominence was 7.25 mm (range 3-12 mm). In patients with <10 mm of component prominence, tenotomy provided groin pain resolution in all cases (n = 8). In patients with ⩾10 mm of prominence, symptoms resolved in 3 out of 4 cases. CONCLUSIONS: Outside-in arthroscopic iliopsoas release provided a high rate of success with no complications in this study, even in patients with moderate acetabular component prominence.

A 65-Year Follow-up of a Judet Prosthesis.

The Judet polymethylmethacrylate hip hemiarthroplasty can be considered a major step in the development of the current total hip replacement. It was designed by the Judet brothers and first implanted in 1946. Although initial results were encouraging, the procedure was abandoned years later because of breakages and wear of the acrylic material. The authors present the case of an 85-year-old man in whom a Judet prosthesis was implanted 65 years ago after a traumatic injury of the left hip. He continued to work for 35 years after the arthroplasty and remained free of pain for an additional 5 years. The pain gradually intensified along with shortening of the left leg. The stem was removed in 2010 because it was protruding from the lateral aspect of the thigh, but no revision of the arthroplasty was performed because of the complexity of the surgery and the patient's age. At 65 years after the arthroplasty, the patient walked with a severe limp aided by 2 crutches and had a Harris Hip score of 30 points. Despite the eventual poor clinical outcome and the marked synovitis and bone loss present in the left hip, the authors believe this case deserves to be highlighted because of its longevity. This is the longest follow-up of a Judet prosthesis in the literature. To the authors' knowledge, just one other case of hip arthroplasty with such long follow-up has been reported. [Orthopedics. 2019; 42(3):e336-e338.].

L5 radiculopathy secondary to migration of a revision stemmed acetabular cup.

INTRODUCTION: Stemmed acetabular components are used in patients undergoing revision total hip arthroplasty in cases with major acetabular defects or pelvic discontinuity. Conflicting results relating to the survival of the component, and complication rates are reported in the literature. We present a case of L5 radiculopathy secondary to proximal migration of this device. CASE DESCRIPTION: A 79-year-old man was admitted to our department in 2012 with increasing pain and paresthesias, initially diagnosed as left L5 radiculopathy. In 2002, he had undergone revision surgery due to aseptic loosening of the acetabular component with a stemmed acetabular cup. Radiological findings were severe osteolysis around the acetabular cup with proximal migration. MRI showed osteolysis involving the left L5/S1 facet joint and evidence of soft tissue in the left foramina encasing the L5 radicular nerve. Nerve conduction and electromyography studies revealed chronic L5 radiculopathy. DISCUSSIONS: This case report illustrates the importance of considering acetabular loosening in a patient presenting with radicular symptoms. If a stemmed acetabular cup is chosen for an acetabular reconstruction, careful surgical technique should be employed in order to achieve durable fixation. If the patient has pelvic discontinuity, other options of reconstruction have showed better outcomes in the literature.