Percutaneous fixation with iliosacral screws has been shown to be a safe and reproducible method for the management of certain posterior pelvic injuries. However, the method is contraindicated in patients with sacral anatomical variations and dysmorphism. The incidence and the pattern of S1 anatomical variations were evaluated in 61 volunteers (35 women and 26 men) using MRI scans of the sacrum. S1 dimensions (12 parameters) in both the transverse and coronal planes were recorded and evaluated. Individuals were divided in four groups based on the S1 body size and the asymmetry of dimensions on the transverse and coronal planes. In 48 (78.6%) patients, dimensions in both planes were symmetrical despite the varying size of the S1 body. In 9 (14.8%) patients, coronal plane dimensions were disproportionally smaller compared to those of the transverse plane with a varying size of S1 body making effective iliosacral screw insertion a difficult task. In 2 (3.3%) patients there was a combination of large transverse plane and small coronal plane dimensions, with large S1 body size. A preoperative imaging study of S1 body size and coronal plane dimensions and an intraoperative fluoroscopic control of S1 dimensions on the coronal plane are suggested for safe iliosacral screw fixation

Background: Clinical tests used for the detection of knee meniscal tears do not present acceptable diagnostic sensitivity and specificity values. Diagnostic accuracy is improved by arthroscopic evaluation or performing magnetic resonance imaging (MRI) tests. The objective of this study was to evaluate the diagnostic accuracy of a new dynamic clinical examination test for the detection of meniscal tears.

Methods: Two hundred and thirteen symptomatic patients with recent knee injuries who all were clinically examined, had MRI tests and underwent arthroscopic surgery and 197 asymptomatic volunteers who all were clinically examined and had MRI tests of their normal knees were included in this study. For clinical examination the medial and lateral joint line tenderness test, McMurray test, Apley compression and distraction test, Thessaly test at 5° and Thessaly test at 20° of flexion were used. For al clinical tests sensitivity, specificity, negative predictive value and diagnostic accuracy rates were calculated against arthroscopic and magnetic resonance imaging data.

Results: Thessaly test at 20° of flexion showed a high diagnostic accuracy rate at the level of 94% and a low number of false negative recordings in detecting tears of both the medial and lateral meniscus. Other traditional clinical examination tests, with the exception of joint line tenderness which presented a diagnostic accuracy rate of 88% in detecting lateral meniscal tears, showed inferior rates.

Conclusions: Thessaly test at 20° of flexion can be safely used as a first line screening clinical test for the detection of meniscal tears reducing the need and the cost of modern magnetic resonance imaging methods.

Introduction: To assess the value of MR imaging (MRI) with regard to union, graft viability and proximal pole bone marrow status, after use of vascularized bone grafts (VBG) for treating scaphoid nonunions (SN).

Methods: VBG from the distal radius were used to treat 52 SN. Clinical and imaging evaluation was used for the pre- and postoperative assessment of all patients. Apart of radiographs obtained in all cases, 19 patients were also assessed postoperatively with MRI at 3 months (15 of 19 were assessed preoperatively with MRI) and 15 had serial MRI evaluations (6–12 months). The clinical follow-up time of this subgroup of 19 patients ranged from 6 to 27 months.

Results: All patients showed clinical signs of union within 12 weeks from the procedure. 3-months MRI showed viability of the bone graft in all cases. At 3 months union was established with plain radiographs in 14 patients; plain MRI showed union in 13 patients but contrast-enhanced MRI revealed union in all cases. Eight patients were considered to have osteonecrosis of the proximal pole intraoperatively: 4 showed proximal pole necrosis with postoperative plain radiographs and 5 of them with plain postoperative MRI. Contrast-enhanced MRI at 3 months showed postoperative reversal of necrotic changes in all 8 scaphoids. Serial MRI at 6 and 12 months, revealed resolution of the bone marrow oedema of the surrounding bones and full graft incorporation in all cases.

Conclusions: Contrast-enhanced MRI is able to assess the viability of the proximal pole and to demonstrate the early union after treatment of SN with VBG allowing thus earlier mobilisation.

Purpose: To assess þbular graft viability and the evolution of the subsequent bone healing into the hosting tunnel. Methods and Materials: Eight patients (10 grafts) with femoral head AVN were examined with 4 consecutive MRI examinations at 2w, 6w, 3m, and 6m postoperatively using a 1T scanner. A dynamic 3D-T1-w TFE sequence (9 sections every 8s) was applied for estimating the perfusion in the graft (SI curve). Multiplanar imaging in the axis of the graft was used for a delayed fat-suppressed T1-w Spin Echo sequence (acquisition matrix 512, slice thickness 3mm). The following parameters were evaluated: a) more or less than 50% increased SI in the graft, b) maximum SI close to the graft, c) maximum width of the medullary enhancement close to the graft, d) width of osteonecrotic area. The þnal MRI examination together with plain x-ray þlms and clinical examination were used to assess outcome. Results: The decrease of% enhancement area in the graft medulla, the gradual decrease of the enhancement in and around the graft, correlated well with the clinical þndings. The dynamic study and the parameter c, showed no correlation with the clinical status. In 2 cases, enhancement close to the upper end of the graft and in the necrotic zone, suggested expanding inversion of the process. Conclusion: High resolution enhanced MRI, may offer an additional means for assessment of the healing process of vascularized peroneal grafts in patients with femoral head necrosis.

Purpose:In this study we investigated the MRI þndings of healing process after arthroscopic meniscal repair. Methods and Materials: 15 patients with buckethandle medial meniscal tears were operated arthroscopically within 3 weeks after injury. All had accurately diagnosed meniscal tear with preoperative MRI. Six patients had an additional anterior cruciate ligament tear, also primarily reconstructed with the meniscal repair. The MR examination was perfrormed with a 1 T scanner, applying the following pulse sequences: T1-w Spin Echo (SE), PD-w Turbo Spin Echo (TSE) with fat suppression, T2-w TSE and T1-w SE in coronal and axial plane after iv administration of paramagnetic contrast agent. The postoperative MRI examinations were performed in 3 weeks intervals starting at the 6th postop and till the 18th , and 6 weeks thereafter. All patients were asymptomatic postoperatively. Results:Grade III and IV signal alterations were present on all MRI scans. Contrast enhanced images showed in addition: a) signal alterations extending through the path of suture out of the meniscus, b) enhancement of the medial collateral ligament simulating injury and c) synovitis in all patients. In one patient examined sequentially, the contrast-enhanced images demonstrated that a and b decreased after 3 months and synovitis was no more evident. Conclusion:Contrast enhanced MRI is the method of choice for demonstrating the normal healing process of the arthroscopic meniscal repair in bucket-handle tears. A gradually disappearing of the abnormal enhancement is related to scar tissue rather than to meniscal retear.

Objective: The aim of this study was to present a review of intraarticular ganglia of the knee. Materials: Cases of intraarticular ganglia of the knee were isolated from a group of 1405 consecutive patients referred for MR imaging examinations of the knee. Diagnoses were conþrmed by means of a histological study after arthroscopic or surgical excision. Results: 14 pts (10 men and four women) had intraarticular ganglia of the knee. 3 ganglia were found in Hoffañs fat pad, 5 were associated with the anterior cruciate ligament, 5 were associated with the posterior cruciate ligament, and one was associated with the ligament of Humphrey. Pain was the most common complaint. Symptoms grew worse with activity in 9 pts. There was associated limited knee extension in 4 cases and limited knee ßexion in 3 cases. One of the three pts with ganglia in Hoffañs fat pad had a palpable mass on physical examination. The cysts were ßuidþlled, with low T1-w and high T2-w signal intensity. 10 cases demonstrated peripheral thin rim enhancement on fat-suppressed contrast-enhanced T1-w SE images. Grad echo sequences were useful in excluding areas of hemosiderin. Conclusion: Intraarticular ganglia of the knee have been found to occur commonly, with a prevalence of 1.% in the present series. The clinical presentation of intra-articular ganglion cyst is varied according to its intra-articular location. Radiologists should be aware of this entity and its defferential diagnoses. The contrast-enhanced sequences allow intraarticular ganglia to be distinguished from PVNS, synovial hemangioma and synovial sarcoma.

Purpose: To review the MRI findings in transient osteoporosis of the hip (TOH) and to investigate the pattern of perfusion in dynamic studies.

Material and Methods: Twenty-seven patients (29 hips), 23–66 years old, were referred for hip pain without history of trauma. In all patients the diagnosis of TOH based on x-rays (decrease bone density of the femoral head) and MRI (bone marrow edema-BME) was confirmed after complete resolution of symptoms and MRI findings after 6–18 months. MRI studies included T1-w SE, T2-w-SPIR-TSE and contrast enhanced T1-w TFE in dynamic mode and delayed SE. Imaging assessment included joint effusion, location and extent of BME (types A–D), sparing of the femoral head, subchondral linear lesions, and collapse.

Results: Joint effusion was observed in 28 of 29 hips. The extent of BME in the femoral head was type A in 5/29 hips, B in 2/29, C in 16/29, D in 6/29. Associated BME of the acetabulum was depicted in 6/29 hips. In 12/29 hips the bone marrow edema was sparing the subchondral area. Subchondral line was only found in 2/29 hips. On dynamic T1–w images all hips presented with a delayed pattern of perfusion up to 40 sec.

Conclusion: MRI findings are useful in diagnosing TOH and differentiating this entity from early AVN.