Magnetic resonance imaging (MRI) versus single photon emission computed tomography (SPECT/CT) in painful total hip arthroplasty: a comparative multi-institutional analysis.

OBJECTIVE: To investigate the value of MRI in comparison to single photon emission computed tomography (SPECT)/CT in patients with painful hip arthroplasties. METHODS: A prospective, multi-institutional study was performed. Therefore, 35 consecutive patients (21 female, 14 male, mean age 61.8 ± 13.3 years) with 37-painful hip arthroplasties were included. A hip surgeon noted the most likely diagnosis based on clinical examination and hip radiographs. Then, MRI and SPECT/CT of the painful hips were acquired. MRI and SPECT/CT were assessed for loosening, infection, fracture, tendon pathology and other abnormalities. Final diagnosis and therapy was established by the hip surgeon after integration of MRI and SPECT/CT results. The value of MRI and SPECT/CT for diagnosis was assessed with a 3-point scale (1 = unimportant, 2 = helpful, 3 = essential). RESULTS: Loosening was observed in 13/37 arthroplasties (6 shaft only, 6 cup only, 1 combined). Sensitivity, specificity, positive predictive value and negative predictive value for loosening of MRI were 86%/88%/60%/100% and of SPECT/CT 93%/97%/90%/100%, respectively. MRI and SPECT/CT diagnosed infection correctly in two of three patients and fractures in two patients, which were missed by X-ray. MRI detected soft tissue abnormalities in 21 patients (6 bursitis, 14 tendon lesions, 1 pseudotumor), of which only 1 tendon abnormality was accurately detected with SPECT/CT. All 5 arthroplasties with polyethylene wear were correctly diagnosed clinically and with both imaging modalities. MRI and SPECT/CT were judged as not helpful in 0/0%, as helpful in 16%/49% and essential in 84%/51%. CONCLUSION: In patients with painful hip arthroplasty SPECT/CT is slightly superior to MR in the assessment of loosening. MRI is far superior in the detection of soft tissue, especially tendon pathologies. ADVANCES IN KNOWLEDGE: To our knowledge this is the first prospective, multiinstitutional study which compares MRI with SPECT/CT in painful hip arthroplasties. We found that MRI is far superior in the detection of soft tissue pathologies, whereas SPECT/CT remains slightly superior regarding loosening.

Hypothenar hammer syndrome: caused by a muscle anomaly? A case report with review of the literature.

The hypothenar hammer syndrome (HHS) is a rare entity of secondary Raynaud's phenomenon. The blunt hypothenar trauma causes a lesion of the vessel wall with a consecutive thrombosis or aneurysm of the ulnar artery at the Guyon's canal. Different risk factors are discussed such as nicotine abuse, or a muscle anomaly in the Guyon's canal. To date, there are five case reports published about muscle anomalies and HHS. We present a case of a 51-year-old shipbuilder with a unilateral HHS on his right dominant hand with a bilateral muscle anomaly. We successfully treated the patient by resection of the aneurysm without a resection of the atypical muscle.

Clinical and radiographical results of labral reconstruction.

Treatment of femoroacetabular impingement (FAI) includes correction of underlying bony deformities. Labrum preservation is recommended whenever possible. In hips, where the labrum is missing or damaged beyond preservation, labral reconstruction is an option to restore labral seal. Between 2008 and 2011, 84 hips underwent treatment for FAI by means of a surgical hip dislocation. In 13 of these hips (11 patients), the severely damaged or missing labrum was reconstructed with ligamentum capitis femoris. Pre- and postoperative radiographic and clinical data were analysed with a mean follow-up of 38 months (range: 19-65 months). Clinical outcome was determined with Oxford hip score (OHS) and overall satisfaction, rest and load pain with a visual analogue scale (VAS; 0-100). Clinical outcome was compared with a control group where labral refixation was performed. Mean OHS improved significantly (P ≤ 0.001) from 29 (SD 8) to 44 (SD 4). Overall satisfaction with the hip increased significantly (P = 0.002) from 44 (SD 35) to 87 (SD 15). Mean VAS for rest pain decreased significantly (P = 0.0004) from 45 (SD 35) to 5 (SD 7) as well as for load pain (P = 0.0007) from 59 (SD 26) to 16 (SD 19). There were no significant differences between the two groups. Reconstruction of the acetabular labrum with ligamentum capitis femoris yields good clinical results. Technical superiority of open labral reconstruction may explain the unexpected, excellent outcome.

Feasibility and preliminary results of SPECT/CT arthrography of the wrist in comparison with MR arthrography in patients with suspected ulnocarpal impaction.

PURPOSE: To evaluate the feasibility and performance of SPECT/CT arthrography of the wrist in comparison with MR arthrography in patients with suspected ulnocarpal impaction. METHODS: This prospective study included 28 wrists of 27 patients evaluated with SPECT/CT arthrography and MR arthrography. Iodine contrast medium and gadolinium were injected into the distal radioulnar and midcarpal joints. Late-phase SPECT/CT was performed 3.5 h after intravenous injection of approximately 650 MBq (99m)Tc-DPD. MR and SPECT/CT images were separately reviewed in relation to bone marrow oedema, radionuclide uptake, and tears in the scapholunate (SL) and lunotriquetral (LT) ligaments and triangular fibrocartilage complex (TFCC), and an overall diagnosis of ulnar impaction. MR, CT and SPECT/CT imaging findings were compared with each other, with the surgical findings in 12 patients and with clinical follow-up. RESULTS: The quality of MR arthrography and SPECT/CT arthrography images was fully diagnostic in 23 of 28 wrists (82%) and 25 of 28 wrists (89%), respectively. SPECT/CT arthrography was not diagnostic for ligament lesions due to insufficient intraarticular contrast in one wrist. MR and SPECT/CT images showed concordant findings regarding TFCC lesions in 22 of 27 wrists (81%), SL ligament in 22 of 27 wrists (81%) and LT ligament in 23 of 27 wrists (85%). Bone marrow oedema on MR images and scintigraphic uptake were concordant in 21 of 28 wrists (75%). MR images showed partial TFCC defects in four patients with normal SPECT/CT images. MR images showed bone marrow oedema in 4 of 28 wrists (14%) without scintigraphic uptake, and scintigraphic uptake was present without MR bone marrow oedema in three wrists (11%). Regarding diagnosis of ulnar impaction the concordance rate between CT and SPECT/CT was 100% and reached 96% (27 of 28) between MR and SPECT/CT arthrography. The sensitivity and specificity of MR, CT and SPECT/CT arthrography were 93%, 100% and 100%, and 93%, 93% and 93%, respectively. CONCLUSION: SPECT/CT arthrography of the wrist is feasible. Regarding diagnosis of ulnar impaction we found a high concordance with MR arthrography. SPECT/CT arthrography of the wrist is an alternative to MR arthrography in patients with contraindications to MR imaging.

Synovitis maps for the assessment of inflammatory diseases of the hand.

OBJECTIVES: To compare accuracy and review times of FLASH-MRI-derived synovitis maps (SM) with conventional MR images (cMRI) in the assessment of articular synovitis and tenosynovitis of the hand. METHODS: 80 hands in 40 patients (mean age, 48 years; range, 15-72 years) were assessed for synovitis on cMRI and SM by two readers independently. Reporting times and diagnostic confidence (scale: 1 = least, 5 = most confident) were measured. Results from an assessment of a panel of senior musculoskeletal radiologists served as the standard of reference. RESULTS: Sensitivity and specificity for the detection of articular synovitis were 0.91/1.00 (R1) and 1.00/0.67 (R2) on cMRI and 0.87/0.75 (R1) and 0.91/0.45 (R2) on SM and for the detection of tenosynovitis 0.95/0.63 (R1) and 0.67/0.79 (R2) on cMRI and 0.67/0.89 (R1) and 0.38/1.00 (R2) on SM. Mean review times (cMRI/SM, sec) were 142/37 (R1) and 167/25 (R2). Mean diagnostic confidence (cMRI/SM) was 3.7/3.4 (R1) and 3.2/3.5 (R2) for articular synovitis and 4.0/4.0 (R1), 3.3/3.7 (R2) for tenosynovitis. CONCLUSION: Synovitis maps provide a comparable diagnostic accuracy to conventional MR images in the assessment of articular synovitis and tenosynovitis of the hand. Because of short review times, synovitis maps provide a fast overview of locations with synovial enhancement.

Do patients with structural abnormalities of the shoulder experience pain after MR arthrography of the shoulder?

PURPOSE: To assess the pain course after intraarticular injection of a gadolinium-containing contrast material admixed with anesthetic for magnetic resonance (MR) arthrography of the shoulder in relation to internal derangements of the shoulder. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this study. The study sample consisted of 655 consecutive patients (249 female, 406 male; median age, 54 years) referred for MR arthrography of the shoulder. Pain level was measured at baseline, directly after intraarticular injection of the gadolinium-containing contrast material admixed with anesthetic, 4 hours after injection, 1 day (18-30 hours) after injection, and 1 week (6-8 days) after injection with a visual analog scale (range, 0-10). MR arthrography was used to assess the following internal derangements: lesions of the rotator cuff tendons and long biceps tendon, adhesive capsulitis (frozen shoulder), fluid in the subacromial bursa, labral tears, and osteoarthritis of the glenohumeral joint. History of shoulder surgery was recorded. Linear regression models were calculated for the dependent variable (difference between follow-up pain and baseline pain), with the independent variable grouping adjusted for age and sex. RESULTS: There was no significant association between pain level over time and internal derangements of the shoulder, nor was there significant association between pain level over time in patients with a history of shoulder surgery and patients without a history of shoulder surgery. CONCLUSION: Neither internal derangements nor prior surgery have an apparent effect on the pain course after MR arthrography of the shoulder.