Intramuscular migration of calcium deposits into the deltoid muscle: two cases of a rare complication of rotator cuff calcific tendinopathy.

Rotator cuff calcific tendinopathy is a common non-traumatic shoulder pain condition that occurs predominantly in the supraspinatus tendon. Ultrasound-guided percutaneous irrigation of calcific tendinopathy (US-PICT) is a valid treatment in the resorptive phase. A complication of calcific tendinopathy is migration of calcium deposits outside the tendon. The most common site of migration is the subacromialsubdeltoid bursa (SASD). Another, but not frequent, type of migration is the intramuscular migration which mostly affects the supraspinatus, the infraspinatus and the biceps brachii muscles. This paper reports two cases of migration of calcification from the supraspinatus tendon to the deltoid muscle. The aforementioned site of migration has so far never been described in literature. Both patients presented calcification in the resorptive phase and therefore were treated by US-PICT.

Plantar fascia evaluation with a dedicated magnetic resonance scanner in weight-bearing position: our experience in patients with plantar fasciitis and in healthy volunteers.

PURPOSE: This study assessed the usefulness of upright weight-bearing examination of the ankle/hind foot performed with a dedicated magnetic resonance (MR) imaging scanner in the evaluation of the plantar fascia in healthy volunteers and in patients with clinical evidence of plantar fasciitis. MATERIALS AND METHODS: Between January and March 2009, 20 patients with clinical evidence of plantar fasciitis (group A) and a similar number of healthy volunteers (group B) underwent MR imaging of the ankle/hind foot in the upright weight-bearing and conventional supine position. A 0.25-Tesla MR scanner (G-Scan, Esaote SpA, Genoa, Italy) was used with a dedicated receiving coil for the ankle/hind foot. Three radiologists, blinded to patients' history and clinical findings, assessed in consensus morphological and dimensional changes and signal intensity alterations on images acquired in both positions, in different sequences and in different planes. RESULTS: In group A, MR imaging confirmed the diagnosis in 15/20 cases; in 4/15 cases, a partial tear of the plantar fascia was identified in the upright weight-bearing position alone. In the remaining 5/20 cases in group A and in all cases in group B, the plantar fascia showed no abnormal signal intensity. Because of the increased stretching of the plantar fascia, in all cases in group A and B, thickness in the proximal third was significantly reduced (p<0.0001) under upright weight-bearing compared with the supine position. CONCLUSIONS: Imaging the ankle/hind foot in the upright weight-bearing position with a dedicated MR scanner and a dedicated coil might enable the identification of partial tears of the plantar fascia, which could be overlooked in the supine position.

Role of high-resolution ultrasonography without and with real-time spatial compound imaging in evaluating the injured posterior cruciate ligament: preliminary study.

PURPOSE: This study sought to compare high-resolution ultrasonography (HRUS) without and with compound imaging in evaluating the injured posterior cruciate ligament (PCL). MATERIALS AND METHODS: Thirteen patients with a magnetic resonance imaging (MRI) diagnosis of PCL lesions (ten acute and three chronic) and 20 healthy controls underwent conventional and compound HRUS performed by the same radiologist who was blinded to the subjects' case-control status. The PCL was scanned in a longitudinal direction in all cases. HRUS images were assessed for PCL thickness by two other radiologists blinded to the number and type of PCL injury. PCLs were classified as normal or injured, and the latter as having acute or chronic injuries. Inter-method reproducibility of measuring PCL thickness was assessed on conventional and compound HRUS images. RESULTS: Complete agreement in classifying normal or injured PCL and acute or chronic PCL injuries was achieved. PCL thickness in volunteers was 4.5+/-0.7 mm on conventional images and 4.6+/-0.7 mm on compound images. On conventional and compound HRUS images, the thickness of acutely injured PCL was 9.1+/-1.5 mm and 9.2+/-1.7 mm, respectively, and that of chronically injured PCL was 7+/-0.9 mm and 7+/-0.8 mm. Inter-method reproducibility of PCL thickness measurements on conventional vs. compound HRUS images was 98.6%. CONCLUSIONS: HRUS is a reliable technique for studying the PCL and detecting PCL injuries.

Role of high-resolution ultrasound in guiding treatment of idiopathic plantar fasciitis with minimally invasive techniques.

PURPOSE: The aim of this study was to assess the reliability of peri-fascial oedema as a sonographic criterion for selecting the most appropriate treatment (ultrasound-guided corticosteroid injection or ultrasound-guided extracorporeal shock wave therapy) of idiopathic plantar fasciitis (IPF). MATERIALS AND METHODS: Sixty-four patients with a clinical diagnosis of unilateral refractory IPF, treated conservatively for at least 8 weeks, were studied with high-resolution ultrasound (HRUS). Pain intensity was evaluated with a visual analogue scale (VAS). HRUS was used to confirm IPF and identify the presence of peri-fascial oedema. Patients with an HRUS diagnosis of IPF were grouped according to the presence (A) or absence (B) of peri-fascial oedema and then randomly allocated to treatment with corticosteroid injection (1) or extracorporeal shock wave therapy (2). Clinical and HRUS follow-up was performed 6 weeks after treatment. RESULTS: HRUS confirmed IPF in 68,97% of patients and identified peri-fascial oedema in 53.33%. Clinical and sonographic improvements were observed in 87.5% and 37.5% of patients in subgroups A1 and A2, respectively, and in 35.71% and 92.85% of those in subgroups B1 and B2, respectively. CONCLUSIONS: The presence of peri-fascial oedema may represent an effective criterion for guiding treatment decisions towards HRUS-guided corticosteroid injection.

High-resolution ultrasonography (HRUS) of the meniscal cyst of the knee: our experience.

PURPOSE: This study was undertaken to assess the diagnostic accuracy of high-resolution ultrasonography (HRUS) in the detection of meniscal cysts. MATERIALS AND METHODS: Over a 2-year period, 1,857 patients underwent magnetic resonance imaging (MRI) of the knee for traumatic or degenerative disorders. All patients with MRI evidence of a meniscal cyst were studied by HRUS. HRUS was also performed on an equal number of patients without MRI evidence of meniscal cyst who were used as a control group. All HRUS examinations were conducted by a radiologist blinded to the MRI findings. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HRUS were assessed with reference to MRI. All patients underwent surgery, and the resected masses were studied by histological examination. RESULTS: MRI allowed identification of a meniscal cyst in 52 patients. HRUS enabled correct detection of the meniscal cyst in 49/52 cases. In the control group, HRUS excluded the presence of meniscal cysts in all cases. HRUS had a sensitivity, specificity, PPV and NPV of 94.23%, 100%, 100% and 94.54%, respectively, for the detection of meniscal cysts. CONCLUSIONS: HRUS is a fairly reliable technique in the detection, characterisation and differentiation of the different forms of meniscal cyst.

MR findings in lipoma arborescens of the knee: our experience.

PURPOSE: This paper describes the role of MR imaging in the identification of the different macroscopic patterns of lipoma arborescens. MATERIALS AND METHODS: Between June 1995 and January 2004, a total of 6387 MR examinations of the knee were retrospectively assessed for the presence of lipoma arborescens. The MR examinations were performed using a superconductive 0.5 T MR unit with a transmitting/ receiving coil dedicated for the extremities. The MR images were acquired with SE T1-weighted, GE T2-weighted and STIR sequences in sagittal, coronal and axial planes with 3-mm thickness and 1-mm gap. RESULTS: Lipoma arborescens was identified in 9 patients (mean age: 36 years). In 2/9 cases a localized lipoma arborescens was detected as a well-marginated single nodule on the suprapatellar bursa without irregularity or synovial hyperplasia. In the remaining 7 cases diffuse lipoma arborescens was identified on the wall of the suprapatellar bursa. In one case of diffuse lipoma arborescens there was involvement of both knees. In all cases the MR findings were verified at surgery and the final diagnosis was made by histological examination. CONCLUSIONS: MR imaging shows a high accuracy in the identification and characterization of lipoma arborescens, due to its multiplanar capabilities and high contrast resolution. MRI allows correct evaluation of size and grade, accurate treatment planning and effective follow-up, avoiding the need for synovial biopsy.

Pigmented villonodular synovitis of the foot: MR findings.

PURPOSE: To evaluate the MRI findings in the various forms of pigmented villonodular synovitis (PVNS) of the foot. MATERIALS AND METHODS: Seven hundred and fifty-three MR studies of the foot performed at our institute between June 1994 and April 2000 were retrospectively reviewed for the presence of PVNS. Spin echo (SE) T1W, Gradient echo (GE) T2*W, and fat suppression (Short Time Inversion Recovery: STIR) images were acquired with a 0.5 T superconductive unit (Vectra, GE Medical System, Milwaukee, WI, USA) provided with a dedicated transmitter/receiver coil. The site and type of lesions, the signal intensity patterns, and the presence of associated changes were evaluated. RESULTS: On the basis of the MR images and the above parameters, six patients (3 men, 3 women, age range: 35-48 years) with PVNS were selected. Three out of six PVNS were nodular, whereas the remaining three were diffuse. Of the three nodular forms, one was found in the sub-talar joint and the remaining two antero-medially to the talus. Instead, all of the diffuse lesions were located on the metatarsus. Perilesional oedema was seen in all cases, although more obvious in the nodular forms, whereas bone involvement (osteochondral erosion) was observed only in the diffuse metatarsal PVNS. Intra-articular bloody effusion was never observed. The MRI findings were confirmed by surgery in all cases. DISCUSSION: The high contrast resolution and multiplanar capabilities of MRI allow the complete evaluation of the structures of the foot affected by PVNS, and of the extent of soft tissue (bursae, synovial or nervous structures), bone and articular involvement. Although not specific, the presence of haemosiderin results in characteristic MR findings, due to the shortening of both T1 and T2 relaxation times. GET2* images are particularly well suited to this PURPOSE: Furthermore, in our experience, FIR images added better depiction of associated swelling. CONCLUSIONS: According to our results, MRI is now the most reliable technique for identifying and classifying PVNS, and allows correct treatment planning and effective monitoring.

[Sportsman hindfoot pain: role of magnetic resonance imaging]. / Tallodinia dello sportivo: ruolo della risonanza magnetica.

PURPOSE: To assess the outcome of Magnetic Resonance Imaging (MRI) in the diagnosis of sportsman hindfoot pain. MATERIALS AND METHODS: Fortythree professional athletes (31 men, 12 women, age range: 17-37 years) affected by hindfoot pain underwent MRI. Spin echo (SE) T1W, Gradient echo (GE) T2*W, and fat suppression (Short Time Inversion Recovery: STIR) images were acquired with a 0.5 T superconductive unit (Vectra, GE Medical System, Milwaukee, WI, USA). A dedicated extremities transmitter/receiver coil was used. The lesion site, the presence of anatomic variants (os trigonum, Haglund's deformity), and signal intensity changes were evaluated. RESULTS: In all cases MRI allowed the identification of the cause of the hindfoot pain, in relation to soft tissue (bursae, synovial or nervous structures), bone and articular diseases. Particularly, as regards soft tissue diseases, tendinous abnormalities and inflammatory bursal involvement were frequently found (77% of cases). Bone diseases (22% of cases with posterior talalgia alone), mostly involved the heel (60%), whereas cartilagineous diseases were present in 9% of cases. In 60% of cases an intra-articular osseous or cartilagineous displaced fragment coexisted, determinating joint locking during foot flexo-extension movements. In 38% of cases contemporary involvement of different articular structures was observed. DISCUSSION: Both MRI high contrast resolution and multiplanar capabilities allow the complete evaluation of hindfoot region. In our experience sagittal and axial planes were particularly well suited for the diagnosis and the assessment of disease extension. Furthermore, T2W (GET2*) and fat suppression (STIR) images allow high sensitivity even in early disease detection, when hyperemia or fluid collection occur. CONCLUSIONS: According to our results, it seems possible to state that nowadays MRI is the most reliable technique for identifying the causes of hindfoot pain, in order to provide a correct and effective pre-therapeutic planning.

[Normal anatomy and pathological conditions of subscapular muscle: US findings compared with surgery]. / Anatomia normale e quadri patologici del muscolo sotoscapolare. Confronto tra ecografia e chirurgia.

PURPOSE: To compare US results with those of surgery in the assessment of the subscapularis tendon. MATERIAL AND METHODS: From January 1995 to December 1998 1500 patients underwent US of the shoulder. 12 of these patients had an injured subscapularis tendon. US results of these patients were evaluated retrospectively and compared with those of surgery. US examinations of the subscapularis tendon were performed with two US units (AU4 Idea and HDI 3000), using linear arrays 10-13 MHz transducers. The following features of the tendon were evaluated: morphology, thickness and echotexture. RESULTS: A) US findings. US showed: - chronic degenerative tendon changes with diffusely inhomogeneous echotexture (5 cases); - focal tears with small hypoechoic ill-defined areas or gross hypo-anechoic areas involving the full thickness of the tendon (4 cases); - complete tendon tear with disappearance on US of the subscapularis tendon or with severe thickening of the tendon (2 cases); - in 1 case of recent anterior dislocation of the shoulder a bulky hematoma was seen with coexisting thickening and subtotal tear of the tendon. B) Surgical findings. US findings were confirmerd at surgery in 10 of the 12 patients. In the patient with anterior dislocation of shoulder the diagnosis hematoma was confirmed, but the subscapularis tendon was undamaged. Moreover, in 1 out of the 5 patients with US diagnosis of chronic degenerative tendon changes, a small focal tear of the tendon was found at surgery. CONCLUSION: US is a first level investigation which is able to demonstrate early changes of the subscapularis tendon and nearby structures. Awareness of pitfalls might decrease the use of second level investigations such as CT arthrography and MR imaging, which on the other hand allow a better definition and assessment of the extent of the injury.

[Os trigonum tarsi syndrome. Role of magnetic resonance]. / Sindrome dell'os trigonum tarsi. Ruolo della Risonanza Magnetica.

INTRODUCTION: The os trigonum tarsi is an accessory bone of the foot localized posterolateral to the lateral tubercle of talus. It is usually an asymptomatic condition. However, particular activities such as ballet, soccer, or football may cause repeated stress and chronic microtraumas to the hindfoot, resulting in the os trigonum syndrome. Pain is typically localized anterior to the Achilles tendon; nevertheless, diagnosis may be very difficult because other conditions may show the same symptoms. Radiography can only demonstrate the os trigonum and its morphostructural changes, while MR imaging can also depict associated soft tissue damage. We report on 9 cases of os trigonum tarsi syndrome studied with MR imaging. MATERIAL AND METHODS: Nine patients with the os trigonum tarsi syndrome were submitted to MRI. All the examinations were performed with the patients in supine recumbency with the injured foot in neutral position and then in forced plantar flexion. Axial and sagittal T1 SE, T2* GE and FIR images were acquired. We evaluated os trigonum location and shape, signal intensity of bone, cartilages and adjacent soft tissues, and possible associated tendon injuries. RESULTS: No changes were found in the os trigonum location and shape. Signal intensity changes were seen in 2/9 cases. Particularly, a small area of very high signal intensity, due to necrosis, was depicted on the talar aspect in 1 case; a subchondral spot of slightly increased signal intensity, with a low-signal outline, was seen on the calcanear aspect in another case. Disruption of the cartilaginous synchondrosis between the accessory navicular bone and the posterior tibial aspect was observed in 7/9 patients. Tenosynovitis of the flexor hallucis longus was associated in 6/9 patients. Pseudoarthrosis with irregular bone margins and high-signal spots within the cartilage was found in 3 cases. Finally, fluid effusion surrounding the os trigonum and adjacent soft tissues was always detected. DISCUSSION AND CONCLUSIONS: The os trigonum syndrome may result from chronic microtraumas. Indeed, forced plantar flexion may cause os trigonum compression between the posterior aspect of the tibial malleolus and the calcaneus, with disruption of the synchondrosis with the lateral tubercle of talus. Joint inflammation may be associated with possible development of pseudoarthrosis. Other possible complications are related to vascular changes which may lead to bone necrosis. Furthermore, the particular anatomical site of the os trigonum may sometimes cause compression to the flexor hallucis longus tendon, resulting in severe tenosynovitis. MR imaging allows complete morphostructural assessment because it depicts the margins and the signal intensity of bone and ligaments on the 3 spatial planes. Particularly, sagittal T2 images best demonstrate the cartilage changes indicating synchondrosis disruption. This condition may cause abnormal mobility of the accessory bone with possible impingement with the posterior aspect of the tibia, or hypomobility due to pseudoarthrosis. Forced plantar flexion acquisitions are particularly useful in this condition because they can demonstrate the mechanism of injury.

Monitoring of fracture calluses with color Doppler sonography.

PURPOSE: Fracture callus formation is closely associated with vascular invasion, and the use of color Doppler sonography has been suggested as a means to monitor, earlier than gray-scale sonography, the first stages of the healing process. We report the findings in a series of patients with tibial fractures in whom both gray-scale sonography and color Doppler imaging were employed to monitor new bone formation at the fracture site. METHODS: Twenty patients with tibial fractures treated with external fixator frames were examined sonographically about 10 days after surgery and then about every 25 days until radiographic demonstration of consolidation. RESULTS: Eighteen of 20 patients had a well-developed callus, while the remaining 2 patients showed delayed fracture healing. In patients with normal callus development, color Doppler imaging demonstrated the progressive formation of new vessels until about 100 days from the surgery; at subsequent examinations, flow signals decreased, and bone remodeling was confirmed by conventional radiography and gray-scale sonography. The resistance indices in these patients tended to decrease in the early weeks after surgery and then slightly increased. In contrast, lack of development of flow signals and persistence of high resistance indices were observed in the 2 patients with delayed fracture healing. CONCLUSIONS: Color Doppler sonography seems to have the capability to predict whether the development of fracture calluses will be normal or delayed.

[Color Doppler-echo in rheumatoid arthritis with extra-articular location. Preliminary experience]. / L'eco color Doppler nell'artrite reumatoide con localizzazione extra-articolare. Esperienza preliminare.

INTRODUCTION: Chronic inflammation in rheumatoid arthritis usually involves articular synovia and extends to other joint components such as bursae, tendons and sheaths. Conventional US with high frequency transducers is an accurate tool for assessing abnormal changes in evolutive rheumatoid arthritis. We investigated the role of color and power Doppler imaging in staging extra-articular involvement, monitoring local inflammatory changes and drug treatment response. MATERIAL AND METHODS: We used a color Doppler unit with a 5-10 Mhz transducer and automatic power Doppler switch to examine 23 patients with tenosynovitis of the flexor (4/23) and extensor (8/23) tendons of the hand, Achilles (6/23) and posterior tibial (3/23) tendons, and long head of biceps (2/23) in acute rheumatoid arthritis. Only minimal pressure was exerted with the probe on the patients' skin to avoid compression and collapse of blood vessels. Ten normal volunteers were also examined as a control group. RESULTS: In all 23 acute rheumatoid arthritis patients, conventional US showed tendon involvement with intra-articular fluid, thickened tendons with partial tear and markedly hypoechoic thickened sheaths. Color signals were shown in all patients. Mid-caliber vessels were visualized coursing straight from the sheath deep into the tendon. Intra-articular signals were seen in 10/12 patients only. Spectral analysis showed arterial flow, with RI ranging .40-.70. Power Doppler added no important information, but improved vessel depiction relative to color Doppler thanks to its higher accuracy in detecting flow signals. There were no color signals in the tendons of the 10 healthy volunteers in the control group. No color signals were seen in both joints and tendons in 12 patients submitted to medical treatment. CONCLUSION: Color and power Doppler can be a necessary and useful integration to high resolution US for flow mapping in rheumatoid arthritis patients with tendon and extra-articular involvement. These modes depict local circulation changes related to disease stage and treatment response.

[Magnetic resonance imaging of seronegative sacroiliitis]. / Studio delle sacro-ileiti sieronegative con Risonanza Magnetica.

INTRODUCTION: The inflammatory involvement of the sacroiliac joint is frequent during seronegative spondylarthritis. The clinical diagnosis of sacroiliitis may be very difficult, especially in the early stage, because joint motion cannot be assessed directly and the clinical picture is very similar to that of lumbar pain. Conventional radiography is negative as long as the structural change in the joint is limited to the synovial membrane and the cartilage (early stage). Computed Tomography (CT) also has many drawbacks, and thus the changes can be shown only when chondritis and enthesitis have already damaged the bone. The disease onset is usually preceded by a long latency; early diagnosis is needed for a proper and timely treatment, which can be made only with a highly sensitive and specific technique. We investigated the diagnostic accuracy of MRI in the early detection of sacroiliitis during seronegative spondylarthritis. MATERIAL AND METHODS: Forty patients with suspected sacroiliitis and negative radiographic findings were submitted to MRI; thirty-seven of them were HLA B27 positive. MRI was performed with a .5 T superconducting unit; T1-weighted SE, T2-weighted FSE, T2* GE, and STIR images were acquired on the oblique coronal plane parallel to the anterior sacrum. Ten asymptomatic volunteers were also examined as a control group. RESULTS: An irregular sacral border and marrow changes at the insertion of the sacroiliac ligaments were seen in 3/10 asymptomatic volunteers. MRI was negative in 7/40 patients, while the synovial compartment was replaced by some tissue with low signal intensity of T1 and high signal on T2 in the other 33 patients; this finding was referred to synovial pannus. Persisting low-signal foci were seen in the synovial compartment in 16/33 patients, which were referred to spared cartilage. High-signal regions were depicted at the bone periphery in 9/33 patients, which areas were consistent with bone erosion; the subchondral bone was markedly hypointense in 5 of these patients, indicating sclerosis. Finally, diffuse high signal intensity was found in the bone marrow in 3/33 patients and referred to infectious sacroiliitis. CONCLUSIONS: MRI appears the method of choice for the early detection of seronegative sacroiliitis because it can show the early changes in cartilage and subchondral bone, filling the gap between the onset of symptoms and radiographic evidence. Moreover, MRI uses no ionizing radiations and makes therefore a precious tool for the diagnosis and follow-up of young patients, hopefully decreasing the use of CT which however provides better detailing of bone and bone degeneration.

Color Doppler ultrasonography of soft-tissue masses.

PURPOSE: To evaluate the capability of color Doppler ultrasonography to differentiate between benign and malignant soft-tissue tumors. MATERIAL AND METHODS: We reviewed the ultrasonographic (US) and color Doppler (CD) findings in 46 consecutive patients with a palpable periskeletal mass. The presence of 3 or more vascular hila and of tortuous and irregular internal vessels within the lesions was considered an indication of malignancy. The CD diagnosis was compared with that obtained at US alone. RESULTS: The sensitivity and specificity of CD were respectively 85% and 92%; these values were higher than those obtained at US alone, respectively 75% and 50%. Arteriovenous malformations presented as lesions with large internal vessels that had low vascular impedance and were easily diagnosed. The wave form patterns within solid tumors were not specific. CONCLUSION: At present, US is commonly employed to confirm the presence of a suspected soft-tissue mass, to locate it accurately, and to indicate its nature. CD finding enhance the role of the US technique in such lesions. The combined use of US and CD can allow the differentiation of benign from malignant lesions, and thus provide a better basis for treatment.

[Biomechanics and semiology of transient lateral patellar dislocation: reliability of magnetic resonance diagnosis]. / Biomeccanica e semeiotica delle dislocazioni transitorie laterali della rotula: affidabilità diagnostica della Risonanza Magnetica.

Transient patellar dislocation is a rare finding. It is usually due to direct trauma in mediolateral direction or to indirect trauma related to violent quadriceps muscle contraction. The clinical diagnosis of transient forms is usually rather difficult because the associated signs (hemarthros and pain at the joint and/or at the vastus medialis insertion) are not specific. Conventional radiography and CT are very accurate in bone studies, but exhibit major limitations in the detection of capsular injuries with intramedullary and/or cartilaginous bone involvement. We investigated MR diagnostic reliability in the study of the injuries caused by transient patellar dislocation. 526 MR examinations of the knee were reviewed retrospectively; fifteen of them were positive for transient patellar dislocation. We used a .5 T superconductive MR unit with a circumferential extremity coil. Axial, coronal and sagittal T1-weighted spin echo, T2*-weighted gradient echo and axial STIR images were acquired. The following criteria were considered specific for the diagnosis of former lateral patellar dislocation: retinacular changes; patella site; signal intensity changes in femoral and patellar intramedullary bone; joint effusion; cartilage and subchondral bone changes. All the patients with transient patellar dislocation had hemarthros with inner retinaculum involvement. The femoropatellar joint was incongruous in 115 cases; patellar subluxation was external in 8/11 patients and lateral in the remaining 3 patients. Medullary bruises were found in 8/15 cases and cartilage injuries in 13/15. Finally, other joint components, such as the posterior horn of the medial meniscus or the anterior cruciate ligament were involved in 6/13 cases. Arthroscopy was performed in 6 patients with associated injuries and confirmed all MR findings (100% agreement). To conclude, in our experience MRI was a very reliable tool to study the injuries due to transient patellar dislocation because it showed specific changes and possible associated traumas, which helps choose the most suitable treatment.

[Normal anatomy and pathologic features of the supraspinatus muscle: comparison between ultrasonography and surgery. Analysis of the potential sources of diagnostic errors]. / Anatomia normale e quadri patologici del muscolo sovraspinato: confronto tra ecografia e chirurgia. Analisi delle possibili fonti di errore diagnostico.

The supraspinatus muscle performs about 60% of the elevation-abduction motion of the arm; therefore, it has a prominent functional role among the extrarotational muscles of the shoulder and is the most injured in subacromial space conditions. Seventy-four patients, aged 21-64 years, were examined to compare ultrasonography (US) results with surgical findings in supraspinatus conditions and to analyze the possible pitfalls in US diagnosis. All the patients underwent conventional X-ray, US and then surgery or arthroscopy. The following criteria were considered: morphology, thickness, echotexture, the convexity of the superior border of supraspinatus tendon, the relationships with the subacromial bursa and the tendon of the biceps long head, the regularity of the bone cortex of the humeral head. US showed: chronic degenerative tendinopathy in 10 patients; perforating focal injuries in 21 patients; deep focal injuries in 10 patients; intramural focal injuries in 6 patients; superficial focal injuries in 8 patients; complete tendon tear with detachment in 19 cases. 62/74 US diagnoses were surgically confirmed, with a specificity of 83.7%. In our experience, US provided very useful information about the pattern, size and site of the injuries and was very helpful in the surgical planning.