MRI findings in the lumbar spines of asymptomatic elite junior tennis players.

OBJECTIVE: To evaluate the MRI findings in the lumbar spines of asymptomatic elite junior tennis players. MATERIALS AND METHODS: The lumbar spine MRI studies of 98 asymptomatic junior elite tennis players (51 male, 47 female) with a mean age of 18 years (age range 11.2-26.3 years; standard deviation 3.1) was reviewed by two consultant musculoskeletal radiologists using consensus opinion. Images were assessed using accepted classification systems. RESULTS: Four players (4%) had no abnormality. Facet joint arthropathy occurred in 89.7% of the players, being mild in 84.5% of cases. There were 41 synovial cysts in 22.4% of the cohort all occurring in the presence of facet arthropathy. Disc degeneration was noted in 62.2 % of players, being mild in 76.2% of those affected. Disc herniation was noted in 30.6% of players, with 86.1% of these being broad based and 13.9% being focal. There was nerve root compression in 2%. There were 41 pars interarticularis abnormalities in 29.6% of patients, 63.4% of these being grades 1-3. There was grade 1 spondylolisthesis in 5.1% of players. The prevalence of facet joint arthropathy, disc degeneration, disc herniation and pars interarticularis fracture was lower in female players than in male and lower in the under 16-year-olds compared with the over 20-year-olds. CONCLUSION: There is a significant amount of underlying pathology that would normally go undetected in this group of asymptomatic elite athletes. Whilst these findings cannot be detected clinically, their relevance is in facilitating appropriate prehabilitation to prevent loss of playing time and potentially career-ending injuries.

Imaging of muscle injury in the elite athlete.

Injuries to muscle in the elite athlete are common and may be responsible for prolonged periods of loss of competitive activity. The implications for the athlete and his/her coach and team may be catastrophic if the injury occurs at a critical time in the athlete's diary. Imaging now plays a crucial role in diagnosis, prognostication and management of athletes with muscle injuries. This article discusses the methods available to clinicians and radiologists that are used to assess skeletal muscle injury. The spectrum of muscle injuries sustained in the elite athlete population is both discussed and illustrated.

Musculoskeletal sonography of the normal foot.

Traumatic, degenerative and rheumatological injuries of the foot are common and can be managed by an ever increasing number of treatments and surgical interventions. High-frequency sonography is inexpensive, portable and is unique in allowing true dynamic assessment of the ligamentous, muscular and tendinous structures. The ultrasound technique demonstrates a steep learning curve and requires detailed knowledge of the foot anatomy. Ultrasound assessment plays an important role in the diagnosis and management of injuries of these structures by guiding rehabilitation and surgical intervention without delay. However, intimate knowledge of the ultrasound appearances of the foot anatomy and normal variants is paramount to correctly identify pathological conditions. We describe the normal sonographic appearances of the foot musculoskeletal structures with MR correlation including joints and their ligaments, dorsal and plantar surfaces of the foot, and the arches of the foot and their supporting structures.

The use of ultrasound in the assessment and treatment of Achilles tendinosis.

The use of ultrasound in the diagnosis and management of disorders of the tendo Achillis is discussed. Some of the pathological processes which occur in Achilles tendinopathy can be identified by ultrasound, which may also be used to direct local treatment.

Medium-to-long term DEXA analysis of an uncemented (AML) femoral component.

We present medium-to-long-term bone mineral density studies assessing bone resorption and remodelling around the cementless femoral component of a total hip arthroplasty (Depuy AML prosthesis). Bone mineral densities were compared with the unoperated side at a time interval of eight years between scans using dual energy X-ray absorptiometry. Initial proximal stress shielding is known but we show that this response continues into the medium to long term in relative terms. We have also found an overall trend for bone mineral density to increase around the prosthesis with the greatest changes occurring distally. The greatest real increase in bone mineral density occurred in Gruen zones 2, 3 and 5 with smaller increases in zones 1, 4, 6 and 7. However, when compared with the contralateral unoperated femur (thus considering systemic changes in bone mineral density), we found these changes only reached statistical significance in Gruen zones 5, 6 and 7.

MRI of the popliteofibular ligament: isotropic 3D WE-DESS versus coronal oblique fat-suppressed T2W MRI.

OBJECTIVE: The objective was to compare isotropic 3D water excitation double-echo steady state (WE-DESS) MRI with coronal oblique fat-suppressed T2-weighted (FS T2W) images in the identification of the popliteofibular ligament (PFL). MATERIALS AND METHODS: A prospective analysis of 122 consecutive knee MRIs was performed in patients referred for knee pain from the orthopaedic clinic. In addition to the standard knee sequences, isotropic WE-DESS volume acquisition through the whole knee and coronal oblique FS T2W fast spin echo sequences through the posterolateral corner were obtained. The presence of the popliteus and biceps femoris tendons, lateral collateral and PFL was documented. Anterior cruciate ligament injury was present in 33 cases and these were excluded from the study because of the risk of associated PFL injury, leaving a total of 89 cases. Of the 42 patients in whom arthroscopic evaluation was subsequently obtained, none were found to have an injury to the PFL. RESULTS: The lateral collateral ligament, biceps femoris and popliteus tendon were identified in all cases on all sequences. The PFL was seen in 81 (91.0%; 95% CI 85.1-97.0%) patients using the WE-DESS sequence and 63 (70.8%; 95% CI 61.3-80.2%) patients using the coronal oblique FS T2W sequence, a statistically significant difference (p < 0.00005). CONCLUSION: Isotropic 3D WE-DESS MRI significantly enhances our ability to identify the popliteofibular ligament compared with coronal oblique fat-suppressed T2-weighted images.

MRI of overuse injury in elite athletes.

Overuse injuries are a common finding in elite athletes. Magnetic resonance imaging (MRI) is the optimal method for the diagnosis of overuse injury in athletes of all levels. We present a review of common and important overuse injuries occurring in elite athletes. A systematic approach based on the functional anatomic units - tendons, bones and joints - may assist in diagnosis of these injuries.

The value of MRI undertaken immediately after reduction of the hip as a predictor of long-term acetabular dysplasia.

Our aim was to determine whether abnormalities noted on MRI immediately after reduction for developmental dysplasia of the hip could predict the persistance of dysplasia and aid surgical planning. Scans of 13 hips in which acetabular dysplasia had resolved by the age of four years were compared with those of five which had required pelvic osteotomy for persisting dysplasia. The scans were analysed by two consultant musculoskeletal radiologists who were blinded to the outcome in each child. The postreduction scans highlighted a number of anatomical abnormalities secondary to developmental dysplasia of the hip, but statistical analysis showed that none were predictive of persisting acetabular dysplasia in the older child, suggesting that the factors which determine the long-term outcome were not visible on these images.

MRI features of posterior ankle impingement syndrome in ballet dancers: a review of 25 cases.

AIM: To describe the magnetic resonance imaging (MRI) features of posterior ankle impingement syndrome (PAIS) in classical ballet dancers. MATERIALS AND METHODS: A retrospective review was undertaken of 25 MRI examinations of the ankle performed on 23 ballet dancers over a 26-month period. Images were examined for the presence of osseous and soft-tissue anatomical variants at the posterior ankle and imaging signs of PAIS. All patients presented with symptoms and signs suggestive of PAIS including posterior ankle pain, swelling and stiffness during plantar flexion. RESULTS: Anatomical variants predisposing to PAIS including as os trigonum and tuberosity arising from the superior calcaneum were clearly depicted. The most common imaging feature of PAIS in our series was high T2 signal posterior to the talocalcaneal joint indicating synovitis (n = 25). Thickening of the posterior capsule (n = 13) and tenosynovitis of flexor hallucis longus (n = 17) were also common. An os trigonum was an infrequent finding (n = 7). Bone marrow oedema, commonly in the posterior talus (n = 10) or in a patchy distribution (n = 10) was often noted. CONCLUSION: MRI is a useful diagnostic tool in PAIS, and in the present series, clearly demonstrates the anatomical variants and range of osseous and soft-tissue abnormalities associated with this condition. Prospective studies are needed to understand the significance and importance of individual MRI findings in producing the symptoms of PAIS.

Basic principles for evaluation of less deformable erythrocyte subpopulations with the Microfiltrometer.

The Microfiltrometer consists of a filtration system for diluted erythrocyte suspensions, through a filter containing 30 cylindrical micropores, 5 microm in diameter, under the influence of a driving pressure. A feeding sinusoidal alternating current of 40 kHz, 300 microA is delivered to the filter. The change in impedance is collected for each temporary flow of erythrocytes through a given micropore. Two main parameters are measured for individually explored erythrocytes: the entry time tau in the micropore and the maximal variation of impedance deltaZ occurring for the transitory flow. The slope deltaZ/tau defines the velocity of pore blockage. A "Microfiltrometer Deformability Index" (MDI) is established by using this slope. When MDI > or = 1, the erythrocyte is considered to be deformable and, conversely, when MDI < 1, the erythrocyte is considered to be undeformable. Using this procedure, less than 2% undeformable erythrocytes in healthy blood samples are identified, with a specificity of 99% and a sensitivity of 97.5%.

Pictorial review: MRI features of foot and ankle injuries in ballet dancers.

Foot and ankle pain is common in ballet dancers. Although clinical examination often points to the underlying cause, imaging is often necessary to confirm the diagnosis and thus ensure appropriate future management. Factors predisposing to the increased incidence of injuries in this population include the classical position in which ballet dancers stand, which is on the tips of the toes in the en pointe position or on the balls of the feet in the demi-pointe position. Furthermore, the repetitious nature of ballet and the long hours spent rehearsing cause over-use injuries. The causes of foot and ankle pain can be thought of in four different groups: the impingement syndromes; tendon abnormalities; osseous pathology; and ligament abnormalities. These will be discussed and illustrated.

Magnetic resonance imaging of bone bruising in the acutely injured knee--short-term outcome.

AIM: To investigate the short-term outcome and associated injuries of bone bruising in the acutely injured knee. METHOD AND MATERIALS: Thirty patients (age range 17-39 years, mean 28 years) with bone bruising identified on magnetic resonance imaging (MRI) after an acute knee injury were rescanned 12-14 weeks post-injury. The volume of bone bruising was measured on coronal STIR (short TI inversion recovery) images and correlation made with the presence and type of ligamentous and osteochondral injuries. RESULTS: All bone bruises were present on repeat MRI. Twenty of the 30 patients (67%) had associated anterior cruciate ligament (ACL) injuries, seven of the 30 (23%) had collateral ligament injuries and three of the 30 (10%) had no associated ligamentous injuries. Greater than 50% reduction in bone bruise volume was demonstrated at repeat scanning in 24 of the 30 patients (80%) and less than 50% in five of the 30 patients (17%). One patient showed an increase in volume of bone bruising at follow-up. There was no correlation between initial size or size reduction of bone bruising and the presence/absence or type of associated injuries. In 21 patients the bone bruises resolved from the periphery, whilst eight patients showed bone bruises that resolved towards the joint margin, all of whom had associated osteochondral injuries. Of the 30 patients, 17 showed bone bruising that extended to the joint margin, 10 of whom had associated osteochondral injuries on MRI. On clinical review some degree of knee pain was still present in all but one of the patients reviewed. The single patient who reported complete resolution of symptoms was one of the three patients with isolated bone bruising. CONCLUSION: Bone bruises persist for at least 12-14 weeks, which is longer than previously quoted. Two discrete patterns of bone bruise resolution have been demonstrated. The size and persistence of bone bruising is not related to the presence or absence or type of associated ligamentous injuries.

The Microfiltrometer (MicroFM): a new filtration device for the assessment of less deformable erythrocyte subpopulations.

The hardware of a new filtration device, the Microfiltrometer (MicroFM), is described. The different components of the device; impedance meter, power supply, measuring cell and its 5-micron Oligopore filter are described and it is shown how they are interrelated and interfaced to a computer for data acquisition. The properties of the filter and the general functioning principle of the device are also elucidated. For each run, the MicroFM generates elementary signals from individual passages of many hundreds of red blood cells (RBCs) through micropores of a given 5-micron Oligopore filter. Analysis of each elementary signal provides two complementary parameters, the transit time tau of the explored RBC and the change in electrical impedance deltaZ caused by the temporary flow of the considered RBC through a particular micropore of the filter. These two parameters can be utilized for reliable assessment of erythrocyte deformability on a cellular level.

Medium-term dexa analysis of an uncemented femoral component.

We investigated the bone remodelling around the AML uncemented femoral component using DEXA analysis and plain radiography in 19 patients at a mean of 89 months from operation. All patients had previously been analysed at a mean of 32 months after surgery. We found a decrease in bone mineral density around the AML implant between the two scans in Gruen zones 1,2 and 6 of up to 8%, but an increase in zones 4,5 and 7 of up to 36%. The increase in zones 4 and 5 were statistically significant (P>0.05). The relative difference between the operated and unoperated hips also showed a reduction in the bone density ratio with time, except in zones 4 and 5 where an increase was seen. We confirm the results of previous studies of proximal stress shielding and distal loading around the AML implant and demonstrate that bone remodelling continues in the medium term. (Hip International 2004; 14: 182-8).

Pelvic connective tissue resilience decreases with vaginal delivery, menopause and uterine prolapse.

BACKGROUND: The late onset of pelvic visceral prolapse and incontinence after childbirth injury could be explained by menopause-associated connective tissue weakening. Uterosacral ligament resilience (UsR) was assessed to determine whether it influenced uterine or pelvic floor mobility, or varied with age, vaginal delivery, menopause or histological variations in the ligament. METHODS: UsR was measured by tensiometry in ligaments from 85 hysterectomy specimens, and was correlated with the presence of symptomatic uterocervical prolapse, prehysterectomy uterine and anorectal mobility, patient age, history of vaginal delivery and menopause. Forty-five of these ligaments were examined for ligament thickness, muscle to collagen ratio, and oestrogen and progesterone receptor density. The results were correlated with UsR. RESULTS: UsR was significantly reduced (P = 0.02) in symptomatic uterovaginal prolapse, but there was no correlation with either uterocervical or anorectal descent in women without symptomatic prolapse. There was a significant decrease in UsR with vaginal delivery (P = 0.003), menopause (P = 0.009) and older age (P = 0.005). The uterosacral ligament was significantly thinner and contained fewer oestrogen and progesterone receptors after menopause, but this did not affect UsR. CONCLUSION: Where pelvic floor muscles are weakened, decreases in pelvic connective tissue resilience related to the menopause may facilitate progression to symptomatic pelvic visceral prolapse.

MnDPDP enhanced magnetic resonance imaging of focal liver lesions.

Mangafodipir trisodium (MnDPDP) is a contrast agent for use in magnetic resonance imaging (MRI) of the liver. The agent is taken up by normal hepatocytes resulting in increased signal on T1-weighted imaging, and is excreted in the biliary system. Hepatocyte-containing liver neoplasms such as hepatomas or focal nodular hyperplasia (FNH), take up MnDPDP and demonstrate varying degrees of enhancement. Metastatic liver deposits and primary liver tumours of non-hepatocyte origin do not typically enhance with MnDPDP thus increasing their conspicuity compared with pre-contrast T1-weighted images. Metastases may demonstrate rim enhancement particularly on delayed imaging at 24 h, which can increase their conspicuity, thus allowing better visualization of small lesions. Functional biliary obstruction due to liver metastases can also result in wedge shaped areas of parenchymal enhancement. The MRI features of various focal liver after continuance with lesions following MnDPDP are discussed and illustrated including primary lesions such as hepatoma and secondary metastases.