Ultrasound characteristics of the patellar and quadriceps tendons among young elite athletes

Tendons adapt in response to sports‐specific loading, but sometimes develop tendinopathy. If the presence of ultrasound changes like hypoechoic areas and neovascularization in asymptomatic tendons precede (and predict) future tendon problems is unknown. The aim of this prospective cohort study was to investigate the relationship between the development of ultrasound changes in the patellar and quadriceps tendons and symptoms of jumper's knee, as well to examine the medium‐term effects of intensive training on tendon thickness among adolescent athletes. Elite junior volleyball athletes were followed with semi‐annual ultrasound and clinical examinations (average follow‐up: 1.7 years). Of the 141 asymptomatic athletes included, 22 athletes (35 patellar tendons) developed jumper's knee. In a multivariate logistic regression analysis, a baseline finding of a hypoechoic tendon area (odds ratio 3.3, 95% confidence interval 1.1 to 9.2) increased the risk of developing symptoms of jumper's knee. Patellar tendon thickness among healthy athletes did not change (Wilk's lambda, P = 0.07) while quadriceps tendon thickness increased (P = 0.001). In conclusion, ultrasound changes at baseline were risk factors for developing symptoms of jumper's knee. Also, among healthy athletes, we observed a 7–11% increase in quadriceps tendon thickness, while there was no increase in patellar tendon thickness.     

Neovascularisation and pain in jumper's knee: a prospective clinical and sonographic study in elite junior volleyball players

Background: The nature of tendon neovascularisation associated with pain over time has not been studied.

Objective: To prospectively study the patellar tendons in elite junior volleyball players.

Methods: The patellar tendons in all students at the Swedish National Centre for high school volleyball were evaluated clinically and by ultrasonography (US) and Power Doppler (PD) sonography.

Results: Altogether 120 patellar tendons were followed for 7 months. At inclusion, jumper's knee was diagnosed clinically in 17 patellar tendons. There were structural changes on US in 14 tendons, in 13 of which PD sonography showed neovascularisation. There were 70 clinically normal tendons with normal US and PD sonography, 24 clinically normal tendons with abnormal US but normal PD sonography, and nine clinically normal tendons with abnormal US and neovascularisation on PD sonography. At 7 month follow up, jumper's knee was diagnosed clinically and by US in 19 patellar tendons, in 17 of which there was neovascularisation. Three of nine clinically normal tendons with structural changes and neovascularisation at inclusion developed jumper's knee. Two of 24 tendons clinically normal at inclusion, with abnormal US but normal PD sonography, developed jumper's knee with abnormal US and neovascularisation on PD sonography. A total of 20 clinically normal tendons with normal US and PD sonography at inclusion developed structural tendon changes and 12 of these also developed neovascularisation.

Conclusions: The clinical diagnosis of jumper's knee is most often associated with neovascularisation in the area with structural tendon changes. The finding of neovessels might indicate a deterioration of the condition.

     

High prevalence of jumper's knee and sonographic changes in Swedish elite junior volleyball players compared to matched controls

Background: Jumper's knee is a common and troublesome condition among senior volleyball players, but its prevalence among elite junior players compared to matched non-sports active controls is not known.

Objective: To clinically, and by sonography, examine the patellar tendons in elite junior volleyball players (15–19 years) at the Swedish National Centre for volleyball and in matched controls.

Methods: The patellar tendons in the 57 students at the Swedish National Centre for high school volleyball and in 55 age, height, and weight matched not regularly sports active controls were evaluated clinically and by grey scale ultrasonography (US) and power Doppler (PD) sonography.

Results: There were no significant differences in mean age, height, and weight between the volleyball players and the controls. In the volleyball group, jumper's knee was diagnosed clinically and by US in 12 patellar tendons (10 male and two female). In 12/12 tendons, PD sonography demonstrated a neovascularisation in the area with structural tendon changes. In another 10 pain free tendons, there were structural tendon changes and neovessels. In the control group, no individual had a clinical diagnosis of jumper's knee. US demonstrated structural tendon changes in 11 tendons, but there was no neovascularisation on PD sonography.

Conclusions: A clinical diagnosis of jumper's knee, together with structural tendon changes and neovascularisation visualised with sonography, was seen among Swedish elite junior volleyball players but not in matched not regularly sports active controls. Structural tendon change alone was seen in 10% of the control tendons.

     

Asymptomatic hypoechoic regions on patellar tendon ultrasound: A 4-year clinical and ultrasound followup of 46 tendons

Patellar tendon ultrasound appearance is commonly used in clinical practice to diagnose patellar tendinopathy and guide management. Using a longitudinal study design we examined whether or not the presence of a hypoechoic ultrasonographic lesion in an asymptomatic patellar tendon conferred a risk for developing jumper's knee compared with a tendon that was ultrasonographically normal. Ultrasonographic, symptomatic and anthropometric assessment was completed at baseline and followup. Magnetic resonance imaging was performed on four tendons that resolved ultrasonographically in the study period. Forty-six patellar tendons were followed over 47+/-11.8 months. Eighteen tendons were hypoechoic at baseline and 28 were ultrasonographically normal. Five tendons resolved ultrasonographically in the study period. Magnetic resonance imaging in four of these tendons was normal. Seven normal patellar tendons at baseline developed a hypoechoic area but only two became symptomatic. Analysis of ultrasonography at baseline and clinical outcome with Fisher's exact test shows there is no association between baseline ultrasound changes and symptoms at followup. In this study there is no statistically significant relationship between ultrasonographic patellar tendon abnormalities and clinical outcome in elite male athletes. Management of jumper's knee should not be solely based on ultrasonographic appearance; clinical assessment remains the cornerstone of appropriate management.     

Significance of ultrasonographically detected asymptomatic tendinosis in the patellar and achilles tendons of elite soccer players: a longitudinal study

BACKGROUND: Chronic tendinosis of the Achilles or patellar tendons, or both, is one of the most frequent and severe conditions that affects athletes in sports such as soccer. It can often end an athlete's sports activity. HYPOTHESIS: Ultrasonography of asymptomatic tendons can be used to predict which athletes will develop tendon symptoms. STUDY DESIGN: Longitudinal study. METHODS: Using ultrasonography of the ankle and knee, we examined 54 elite soccer players in the top Danish soccer league before and after a single season (in January and December). RESULTS: At the start of the season, ultrasonography had revealed abnormalities in 29% of those examined. Eighteen percent (18 of 98 tendons) were observed to have abnormal sonographic findings in the patellar tendon at the initial examination in January. These athletes were found to have a 17% risk of developing symptomatic jumper's knee during the 12-month season. Eleven percent (11 of 96 tendons) were observed to have abnormal sonographic findings in the Achilles tendon at the initial examination; it was calculated that they had a 45% risk of developing symptoms of Achilles tendinosis. Only one of the players with normal tendons in January actually developed symptoms by the end of the season. CONCLUSIONS: For the first time it is now possible to identify risk factors for the development of serious tendon disorders in asymptomatic athletes. Future studies may be directed at developing preventive treatment to reduce the risk of chronic, therapy-resistant symptoms of tendinosis and ruptures.     

The patellar tendon: thickening,internal signal buckling,and other MR variants

We studied the range of appearance of asymptomatic patellar tendons and evaluated the effect of age, weight, joint effusions, and anterior cruciate ligament (ACL) tears on this tendon. One hundred and seventy-three patellar tendons in asymptomatic patients were studied at 1.5 tesla. Sagittal short and long TE images were evaluated in regard to tendon thickness, ratio of thickness of patellar to quadriceps tendons, frequency, location, and severity of intratendon signal, and frequency and severity of tendon buckling. Results were correlated with patient age, sex, weight, the presence of ACL tears, and relative volumes of joint fluid. The mean thickness of the patellar tendon was 0.52 cm. The patellar to quadriceps tendon ratio was 0.72. The patellar tendon frequently (74%) had focal areas of signal apparently within it. This signal was usually subtle, V-shaped (95%), and seen posteriorly in the proximal end of the tendon (82%). Intratendon signal was also seen commonly in the inferior aspect of the tendon (32%). This signal intensity did not increase with greater T2-weighting (99%). Buckling of the patellar tendon was a frequent asymptomatic variant (71%) but was also associated with joint effusions (p<0.01) and ACL tears (p=0.01). Buckling, intratendon signal, and tendon thickness increased with weight and age. Variation of the magnetic resonance appearance of the patellar tendon is frequent. Many of these changes appear to represent subclinical degeneration. Buckling of this tendon also may occur secondary to joint effusions or ACL tears.     

Patellar tendon morphology in volleyball athletes with and without patellar tendinopathy

Appropriate management of patellar tendinopathy requires distinguishing between inflammatory and degenerative conditions, often difficult because tendon thickening can be a normal or pathological adaptation, and micromorphology is not observable on clinical imaging. The purpose of this study was to quantitatively examine patellar tendon micro‐ and macromorphology in volleyball athletes and relate those findings to reported symptoms. Longitudinal ultrasound images of proximal and distal patellar tendons were acquired from 84 male elite volleyball athletes (44 symptomatic, 40 asymptomatic) and 10 asymptomatic nonathlete controls. Micromorphology was determined using two‐dimensional Fast Fourier Transform analysis providing a discriminating peak spatial frequency parameter (PSF). Macromorphology (patellar tendon thickness) was measured using Image J software. All athletes regardless of symptoms had thicker proximal tendons compared to nonathletes, suggesting a normal adaptation to training loads. However, symptomatic athletes demonstrated lower PSF than asymptomatic athletes and nonathletes at the proximal tendon, suggesting greater collagen disorganization, and tendon degeneration rather than inflammation. Only symptomatic athletes had thicker distal tendons than nonathletes, but there was no difference in PSF distally. Diagnostic ultrasound enhances the understanding of the micromorphology of patellar tendons, supporting the rationale for management that remodels the degenerated tendon instead of treating inflammation.     

Previously identified patellar tendinopathy risk factors differ between elite and sub‐elite volleyball players

Patellar tendinopathy is the most common knee injury incurred in volleyball, with its prevalence in elite athletes more than three times that of their sub‐elite counterparts. The purpose of this study was to determine whether patellar tendinopathy risk factors differed between elite and sub‐elite male volleyball players. Nine elite and nine sub‐elite male volleyball players performed a lateral stop–jump block movement. Maximum vertical jump, training history, muscle extensibility and strength, three‐dimensional landing kinematics (250 Hz), along with lower limb neuromuscular activation patterns (1500 Hz), and patellar tendon loading were collected during each trial. Multivariate analyses of variance (P < 0.05) assessed for between‐group differences in risk factors or patellar tendon loading. Significant interaction effects were further evaluated using post‐hoc univariate analysis of variance tests. Landing kinematics, neuromuscular activation patterns, patellar tendon loading, and most of the previously identified risk factors did not differ between the elite and sub‐elite players. However, elite players participated in a higher training volume and had less quadriceps extensibility than sub‐elite players. Therefore, high training volume is likely the primary contributor to the injury discrepancy between elite and sub‐elite volleyball players. Interventions designed to reduce landing frequency and improve quadriceps extensibility are recommended to reduce patellar tendinopathy prevalence in volleyball players.     

Achilles tendon structure improves on UTC imaging over a 5‐month pre‐season in elite Australian football players

Pre‐season injuries are common and may be due to a reintroduction of training loads. Tendons are sensitive to changes in load, making them vulnerable to injury in the pre‐season. This study investigated changes in Achilles tendon structure on ultrasound tissue characterization (UTC) over the course of a 5‐month pre‐season in elite male Australian football players. Eighteen elite male Australian football players with no history of Achilles tendinopathy and normal Achilles tendons were recruited. The left Achilles tendon was scanned with UTC to quantify the stability of the echopattern. Participants were scanned at the start and completion of a 5‐month pre‐season. Fifteen players remained asymptomatic over the course of the pre‐season. All four echo‐types were significantly different at the end of the pre‐season, with the overall echopattern suggesting an improvement in Achilles tendon structure. Three of the 18 participants developed Achilles tendon pain that coincided with a change in the UTC echopattern. This study demonstrates that the UTC echopattern of the Achilles tendon improves over a 5‐month pre‐season training period, representing increased fibrillar alignment. However, further investigation is needed to elucidate with this alteration in the UTC echopattern results in improved tendon resilience and load capacity.     

Similar histopathological picture in males with Achilles and patellar tendinopathy

PURPOSE: To ascertain whether there are differences in the histopathological appearance of tendinopathic Achilles and patellar tendons. METHODS: In males, we studied biopsies from tendinopathic Achilles (N = 28; average age 34.1 yr) and patellar tendons (N = 28; average age 32.1), Achilles tendons (N = 21; average age 61.8 yr) from deceased patients with no known tendon pathology, and patellar tendons (N = 15; average age 28.3) from patients undergoing anterior cruciate ligament reconstruction. Hematoxylineosin stained slides were interpreted using a semiquantitative grading scale (0: normal to 3: maximally abnormal) for fiber structure, fiber arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen stainability, and hyalinization. All slides were assessed blindly twice, the agreement between two readings ranging from 0.170 to 0.750 (kappa statistics). RESULTS: The highest mean score of tendinopathic Achilles tendons was not significantly different from that of tendinopathic patellar tendons (11.6 +/- 5 and 10.4 +/- 3, respectively). The ability to differentiate between an Achilles tendon and a patellar tendon was low. CONCLUSIONS: Tendinopathic Achilles and patellar tendons show a similar histological picture. It was not possible to identify whether a specimen had been harvested from an Achilles or a patellar tendon on the basis of histological examination. The general pattern of degeneration was common to both tendinopathic Achilles and patellar tendons. A common, as yet unidentified, etiopathological mechanism may have acted on both these tendon populations.     

Achilles tendon pain intensity and level of neovascularization in athletes as determined by color Doppler ultrasound

The cause of pain in Achilles tendinopathy is thought to be related to the presence of neovascularization in the tendon as seen on color Doppler ultrasound. Asymptomatic pathology has been observed in patellar tendons of elite athletes. The purpose of this study was to examine the prevalence of Achilles tendon pain and the characteristics of Achilles tendons in a young athletic population. Sixty-four varsity athletes underwent color Doppler ultrasound imaging to determine tendon thickness, presence of degeneration and neovascularization. The presence of swelling and tenderness was determined, and Achilles tendon pain was rated on three visual analogue scales (VAS) (pain during exercise, pain at rest, pain during daily activities) as well as on the VISA-A scale. Tendon symptoms were not related to the presence of neovascularization. There was a low prevalence of Achilles tendinopathy, tenderness, and neovascularization in this population. Neovascularization was seen in both a painful and a non-painful tendon.     

Achilles tendinopathy in club runners

Ultrasound (US) changes within the Achilles tendon are present in asymptomatic Achilles individuals. We assessed the association of US signs with symptoms of Achilles tendinopathy in a study group of club level running athletes and in a control group of athletes training at least 2 times per week. The Achilles tendon was assessed in its entirety on longitudinal US scans, at the musculotendinous junction (MTJ), the calcaneal insertion site, and at a midtendon point. 25 middle distance runners, 19 males and 6 females, aged from 18 to 58, were enrolled in each group. When compared to control athletes, club level runners presented significantly increased tendon thickness (p=0.046) at the musculo-tendinous junction, and increased tendon thickness, with no statistical significance, at the other landmarks points. Although club level runners were significantly more symptomatic and predisposed to develop signs of tendinopathy than control athletes (p=<0.001), ultrasound abnormalities were not significantly associated with local symptoms complained at the US investigation time. Prospective studies on asymptomatic athletes are needed to define the predictive value of US signs of Achilles tendinopathy in the development of symptoms in the long-term.     

The prevalence of Achilles and patellar tendon injuries in Australian football players beyond a time‐loss definition

Little is known about the prevalence and associated of morbidity of tendon problems. With only severe cases of tendon problems missing games, players that have their training and performance impacted are not captured by traditional injury surveillance. The aim of this study was to report the prevalence of Achilles and patellar tendon problems in elite male Australian football players using the Oslo Sports Trauma Research Centre (OSTRC ) overuse questionnaire, compared to a time‐loss definition. Male athletes from 12 professional Australian football teams were invited to complete a monthly questionnaire over a 9‐month period in the 2016 pre‐ and competitive season. The OSTRC overuse injury questionnaire was used to measure the prevalence and severity of Achilles and patellar tendon symptoms and was compared to traditional match‐loss statistics. A total of 441 participants were included. Of all participants, 21.5% (95% CI : 17.9‐25.6) and 25.2% (95% CI 21.3‐29.4) reported Achilles or patellar tendon problems during the season, respectively. Based on the traditional match‐loss definition, a combined 4.1% of participants missed games due to either Achilles or patellar tendon injury. A greater average monthly prevalence was observed during the pre‐season compared to the competitive season. Achilles and patellar tendon problems are prevalent in elite male Australian football players. These injuries are not adequately captured using a traditional match‐loss definition. Prevention of these injuries may be best targeted during the off‐ and pre‐season due to higher prevalence of symptoms during the pre‐season compared to during the competitive season.     

Soft-tissue radiography, computed tomography, and ultrasonography of partial Achilles tendon ruptures

Ultrasonography (US) was compared with soft-tissue radiography (STR) and computed tomography (CT) for demonstration of partial Achilles tendon ruptures. Thirty-nine patients suffering from chronic localized painful Achilles tendon swelling were examined. The patients had all undergone a previous clinical examination, resulting in a suspicion of a non-healed partial tear in 62 out of the 78 tendons. STR showed unspecific tendon pathology such as thickening and diffuse tendon margins. CT resulted in a better delineation of intra- as well as extratendinous abnormalities compared to STR. Various pathologic changes were seen on CT in 54 tendons and in 29 of these, localized intratendinous hypodensities indicated partial ruptures. At US, abnormal changes were observed in 69 tendons, of which 54 had discontinuity of tendon fibers, focal hypoechoic areas, and localized swelling indicating partial ruptures. In 9 cases with surgically proven partial ruptures, US was correct in all cases, while CT was false-negative in 3. STR only showed localized swelling. It was concluded that US was a better method than STR and CT for the detection of partial ruptures and the US findings correlated well with the surgical findings.     

Intratendinous Injection of Platelet-Rich Plasma under US Guidance to Treat Tendinopathy: A Long-Term Pilot Study

PurposeTo assess the potential therapeutic effect of intratendinous injection of platelet-rich plasma (PRP) under ultrasound (US) guidance to treat tendon tears and tendinosis in a pilot study with long-term follow-up.Materials and MethodsThe study included 408 consecutive patients referred for treatment by PRP injection of tendinopathy in the upper (medial and lateral epicondylar tendons) and the lower (patellar, Achilles, hamstring and adductor longus, and peroneal tendons) limb who received a single intratendinous injection of PRP under US guidance. Clinical and US data were retrospectively collected for each anatomic compartment for upper and lower limbs before treatment (baseline) and 6 weeks after treatment. Late clinical data without US were collected until 32 months after the procedure (mean, 20.2 months). The McNemar test and regression model were used to compare clinical and US data.ResultsQuickDASH score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and residual US size of lesions were significantly lower after intratendinous injection of PRP under US guidance at 6 weeks and during long-term follow-up compared with baseline (P < .001 in upper and lower limb) independent of age, gender, and type of tendinopathy (P > .29). No clinical complication was reported during follow-up.ConclusionsIntratendinous injection of PRP under US guidance appears to allow rapid tendon healing and is well tolerated.     

Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study

OBJECTIVES: To (a) compare ultrasound (US; including grey scale and colour and power Doppler) and magnetic resonance imaging (MRI; with high resolution and fat saturation sequences) with a clinical yardstick in the evaluation of chronic Achilles tendinopathy, and (b) examine whether either imaging method predicted 12 and 24 month clinical outcome. METHODS: Forty five patients with symptoms in 57 Achilles tendons were diagnosed with tendinopathy by an experienced sports medicine doctor. All patients underwent US examination (12 MHz probe) with colour and power Doppler, and 25 consecutive patients also underwent MRI with high resolution T1 weighted and STIR sequences. RESULTS: US identified abnormal morphology in 37 of the 57 symptomatic tendons (65%) and normal morphology in 19 of 28 asymptomatic tendons (68%). Baseline US findings did not predict 12 month clinical outcome. The addition of colour and power Doppler did not improve the diagnostic performance of US. MRI identified abnormal morphology in 19 of 34 symptomatic tendons (56%) and normal morphology in 15 of 16 asymptomatic tendons (94%). Lesser grades of MR signal abnormality at baseline were associated with better clinical status at 12 month follow up. CONCLUSIONS: US and MRI show only moderate correlation with clinical assessment of chronic Achilles tendinopathy. Graded MRI appearance was associated with clinical outcome but US was not.     

Prevalence of Achilles and patellar tendinopathy and their association to intratendinous changes in adolescent athletes

Achilles (AT) and patellar tendons (PT) are commonly affected by tendinopathy in adult athletes but prevalence of symptoms and morphological changes in adolescents is unclear. The study aimed to determine prevalence of tendinopathy and intratendinous changes in ATs and PTs of adolescent athletes. A total of 760 adolescent athletes (13.0 ± 1.9 years; 160 ± 13 cm; 50 ± 14 kg) were examined. History, local clinical examination, and longitudinal Doppler ultrasound analysis for both ATs and PTs were performed including identification of intratendinous echoic changes and vascularization. Diagnosis of tendinopathy was complied clinically in case of positive history of tendon pain and tendon pain on palpation. Achilles tendinopathy was diagnosed in 1.8% and patellar tendinopathy in 5.8%. Vascularizations were visible in 3.0% of ATs and 11.4% of PTs, hypoechogenicities in 0.7% and 3.2% as well as hyperechogenicities in 0% and 0.3%, respectively. Vascularizations and hypoechogenicities were statistically significantly more often in males than in females (P ≤ 0.02). Subjects with patellar tendinopathy had higher prevalence of structural intratendinous changes than those without PT symptoms (P ≤ 0.001). In adolescent athletes, patellar tendinopathy is three times more frequent compared with Achilles tendinopathy. Longitudinal studies are necessary to investigate physiological or pathological origin of vascularizations and its predictive value in development of tendinopathy.     

Evidence of accumulated stress in Achilles and anterior knee tendons in elite badminton players

Tendon-related injuries are a major problem, but the aetiology of tendinopathies is unknown. In tendinopathies as well as during unaccustomed loading, intra-tendinous flow can be detected indicating that extensive loading can provoke intra-tendinous flow. The aim of present study is to evaluate the vascular response as indicated by colour Doppler (CD) activity in both the Achilles and patella tendon after loading during high-level badminton matches. The Achilles tendon was subdivided into a mid-tendon, pre-insertional, and insertional region and the anterior knee tendons into a quadriceps-, patella- and tuberositas region. Intra-tendinous flow was measured using both a semi-quantitative grading system (CD grading) and a quantitative scoring system (CF) on colour Doppler. Intra-tendinous flow in the Achilles and anterior knee tendons was examined in fourteen single players before tournament and after 1st and 2nd match, respectively on both the dominant and non-dominant side. All players had abnormal intra-tendinous flow (Colour Doppler ≥ grade 2) in at least one tendon in at least one scan during the tournament. At baseline, only two of the 14 players had normal flow in all the tendons examined. After 1st match, tendencies to higher intra-tendinous flow were observed in both the dominant patella tendon and non-dominant quadriceps tendon (P-values n.s.). After 2nd match, intra-tendinous flow was significant increased in the dominant patella tendon (P = 0.009). In all other locations, there was a trend towards a stepwise increase in intra-tendinous flow. The preliminary results indicate that high amount of intra-tendinous flow was found in elite badminton players at baseline and was increased after repetitive loading, especially in the patella tendon (dominant leg). The colour Doppler measurement can be used to determine changes in intra-tendinous flow after repetitive loading.     

Pathological tendons maintain sufficient aligned fibrillar structure on ultrasound tissue characterization (UTC)

Structural disorganization in the tendon is associated with tendinopathy, with little research investigating whether disorganization overwhelms the overall structural integrity of the tendon. This study investigated the mean cross‐sectional area (CSA) of aligned fibrillar structure as detected by ultrasound tissue characterization (UTC) in the pathological and normal Achilles and patellar tendons. Ninety‐one participants had their Achilles and/or patellar tendons scanned using UTC to capture a three‐dimensional image of the tendon and allow a semi‐quantification of the echopattern. The mean CSA of aligned fibrillar structure (echo type I + II) and disorganized structure (echo type III + IV) was calculated based on UTC algorithms. Each tendon was classified as either pathological or normal based solely on gray‐scale ultrasound. The mean CSA of aligned fibrillar structure was significantly greater (P ≤ 0.001) in the pathological tendon compared with the normal tendon, despite the pathological tendon containing greater amounts of disorganized structure (P ≤ 0.001). A significant relationship was observed between the mean CSA of disorganized structure and anteroposterior diameter of the Achilles (R² = 0.587) and patellar (R² = 0.559) tendons. This study is the first to show that pathological tendons have sufficient levels of aligned fibrillar structure. Pathological tendons may compensate for areas of disorganization by increasing in tendon thickness.     

Achilles tendon (TA) size and power Doppler ultrasound (PD) changes compared to MRI: a preliminary observational study

AIM: To assess whether abnormal Achilles tendon (TA) magnetic resonance imaging (MRI) and spectral ultrasound (US) features have associated development of microvascular power Doppler (PD) flow. MATERIALS AND METHODS: In a prospective, controlled and blinded study six patients with TA symptoms were compared to five with other ankle abnormalities. Two radiologists independently measured the mean maximal anteroposterior diameter on MRI and conventional US (categorized as normal <6 mm, mild 6.1-10 mm, moderate 1.1-1.5 cm and severely enlarged > 1.6 cm), assessed morphology and studied the vessels using power Doppler. They formed a consensus over discrepancies. Sonography of the contralateral side within 24 h was used as a control. RESULTS: Twenty-one tendons in six women and five men, aged 45-77 years (mean 57.6 years), were examined, 12 tendons were of normal US morphology and size (< 6 mm), and did not exhibit PD's flow (interobserver agreement K > 0.74). Of the 12 tendons studied by MRI five were normal, seven tendons were enlarged, five of which had a proportionate increase in PD flow at the margin on the deep surface and four also had vessels in the centre of the tendon. All five of these tendons had high signal on T2-weighting (T2W). Of the two mildly enlarged tendons of intermediate signal on T1 and T2W, one showed PD flow and the other did not. CONCLUSIONS: In patients with TA disease power Doppler ultrasound shows proliferation of vessels in enlarged, abnormal tendons demonstrated on MRI and standard ultrasound, in the absence of definite tears.