Table 4 Ultrasound protocol administration and results of included studies

Patellar: supine position with approximately 30° knee flexion, with a pillow under the popliteal space.

Not described

Bilateral

Monitoring

5 mm distal to the inferior pole of the patella.

Of the 146 tendons, 91 had some degree of sonographic abnormality. Three main patterns were identified: I, II, III.

Patterns of sonographic abnormalities, including NV, demonstrated greater pain. A combination of 2 or more ultrasound abnormalities can determine variations in pain variations among basketball players.

[9]

Achilles: Prone with the feet hanging over the table edge and the ankles flexed to 90°; Patellar: supine with 120° knee flexation

Not described

Bilateral

Predicting

Short-axis images were saved at the tendon location at its greatest width while the longitudinal assessment was made in the midline tendon, centered over the area of maximum thickness.

24.1% of the Achilles tendon had structural abnormalities; and 23.1% of the patellar tendons before the race. The participants with tendon structural were 2–3 times more prone to develop pain within 1 year than those without

25% of the asymptomatic runners had structural changes, which lead to an increased risk of Achilles and patellar tendon pain within 12 months.

[11]

Patellar: patient in supine with 90°knee flexion.

From proximal to distal

Unilateral

Monitoring

1 cm distal to the disappearance of the patellar inferior pole.

During the study, 9% of participants developed tendon pathology, out of which only 2–5% reported tendon pain.

Abnormality in the proximal part of the patella can occur during adolescence

[12]

Patellar: supine, with approx. 100° of knee flexion

Proximal to distal

Unilateral

Monitoring

20 mm distal from the apex of the patella

No remarkable changes in tendon structure (echo types I-IV) over the sports event.

Either the tendon structure is stable enough, UTC is not significant, or decreased tournament/time for considerable change.

[7]

Patellar and quadriceps: supine, with slight knee flexion (20°)

Proximal to distal

Bilateral

Monitoring

The proximal, mid, and distal parts of the tendons

Out of 141 asymptomatic athletes, only 22 athletes (35 patellar tendons) advanced to the jumper’s knee.

The risk factors to develop jumper’s knee among adolescent volleyball athletes were hypoechoic areas and neovascularization at baseline. 7–11% increased quadriceps tendon thickness in healthy athletes, and no change in patellar tendon thickness.

[8]

Achilles: Prone, legs hanging over the edge of the table.

Not described

Bilateral

Predicting

The mid-portion of the free Achilles tendon (2–6 cm proximal to the calcaneal insertion)

A remarkable reduction in tendon stiffness was due to Marathon running (p = 0.049) and an increase in Doppler signals (p = 0.036). Achilles tendon pain was observed in four out of 21 (19%) runners post-race [VAS 4.0 (±1.9), VISA 74.2 (±10.1)]. Decreased stiffness of the tendon at baseline was correlated with post-marathon Achilles tendon pain (p = 0.016).

The prior soft Achilles’ tendon properties seen on; sonoelastography may be a risk factor for the occurrence of symptoms after running.

[13]

Patellar and quadricep; supine with 30° knee flexion; Achilles: the patient prone, the heels overhanging couch, and the ankles flexed to 90°

Proximal to distal

Bilateral

Predicting

10 mm proximal to the superior-posterior aspect of the calcaneus, the patellar tendon 5 mm distal to the patellar attachment, and the quadriceps tendon 10 mm proximal to its patellar insertion

At baseline readings, the abnormal patellar tendon was probably more prone to develop symptoms than those normal (P < 0.05, Fisher’s exact test), while US and PD abnormalities on Achilles and quadriceps tendons were not associated with the development of symptoms over a longer duration. A small percentage of tendons diagnosed as normal at baseline (1.45%) exhibited US abnormalities at follow-up of 3 years.

It is questionable that secondary investigations through PD give more information or alter prognosis in patients with a US diagnosis of tendinopathy.

[16]

Not described

Proximal to distal

Bilateral

Predicting

1 cm from both origin and insertion

There was a weak association of moderate or severe hypoechoic defects with future development of symptoms of tendinopathy (p = 0.0381); and no correlation between any of the other ultrasound abnormalities and the development of the symptoms.

Ballet dancers have common sonographic abnormalities, but only the presence of focal hypoechoic changes are predictive of future symptoms development in tendons.

[20]

Achilles: Prone position with a pillow under the distal tibia with feet hanging over the table in slight plantarflexion. Anterior knee tendons: supine position with 15° knee flexion with a pillow (relaxed position).

Not described

Bilateral

Predicting

2 cm in the longitudinal direction of the tendon

36% experienced pain in 51 tendons (15%), (P = .0002). The abnormal flow was observed in (83%) at the beginning of the season compared with (48%) at the follow-up. (P < .0001). (68%). had abnormal flow. (85%) with the abnormal flow at the start of the season were pain-free. At the end of the season, (35%) had abnormal flow. The majority of the tendons (73%) were pain-free and abnormal flow at the beginning of the season was normalized (no pain and normal flow) at the end of the season.

It was impossible to establish any association between intratendinous flow and pain at the beginning of the season or the follow-up (end of the season). Intratendinous flow at the beginning of the season could not predict the symptomatic outcome at the end of the season.

[17]

Achilles: Prone position with the legs of the subjects hanging over the edge of the table and ankles passively flexed at 90°.

Not described

Bilateral

Predicting

Point 3 cm proximal to the calcaneal insertion and at its thickest.

The highest odds ratio (OR) for the appearance of MPT within 1 yr was found for intratendinous blood flow (“neovascularization,” OR = 6.9, P < 0.001). The subjects having positive Achilles tendinopathy history were found to have high risk. (OR = 3.8, P < 0.001). Another significant parameter was a spindle-shaped thickening of the tendon observed on PDU (Wald χ2 = 3.42).

Healthy runners with the diagnosis of intratendinous microvessels in the Achilles’ tendon on PDU can predict the appearance of MPT symptoms.

[19]

Achilles: Prone with their ankles in a relaxed position (approximately plantar grade).

Not described

Bilateral

Predicting

insertion on the calcaneus (defined on the US as the clearest image of the pre-Achilles bursa); the musculotendinous junction [the area examined on the US where the last soleus fibers attach to the tendon and the midpoint of the two

mid-tendon thickness at baseline was greater (p = 0.041) in tendons that had symptoms [median (IQR): 0.53 (0.51–0.55) cm] in the upcoming year than tendons remaining asymptomatic [0.48 (0.45–0.52) cm]

There was no association between the presence of baseline ultrasound signs and future development of symptoms in the upcoming years (Chi-Square: 1.180, p = 0.277). A thicker tendon thickness of the mid-portion was considered as a risk factor for future development of Achilles tendinopathy in elite soccer players.

[35]

Not described

Not described

Bilateral

Predicting

Three categories on greyscale imaging; normal, diffuse thickening, hypoechoic

Painful tendons with hypoechoic regions (59%) and contain Doppler flow (42%) than tendons with diffuse thickening (pain in 43% and Doppler flow in 6%)

The transitions identified between normal, diffusely thickened tendons and those containing a hypoechoic region indicate that these greyscale US changes may show different phases of tendon pathology.

[36]

Not described

Not described

Bilateral

Predicting

6 mm from the insertion at the lower patellar pole. The normal Achilles tendons thickness was measured 20 mm from the distal attachment at the calcaneus, and Achilles tendons with increased thickness were measured at the thickest point.

The presence of ultrasonographic tendon abnormalities before the season greatly increased the risk of developing tendon symptoms during the season (relative risk = 1.9; 95% CI, 1.2–3.1; P = .009).

With the use of ultrasonography, tendon changes in soccer players can be diagnosed before symptomatic appearance.

[15]

Patellar: Supine, first with the extended knee and then with the slightly flexed knee (20°)

Not described

Bilateral

Predicting

Not described

Development of patellar tendinopathy in 2 of 25 (2 were excluded) tendons that were normal (clinical and US+PD) at inclusion and were also present in six tendons.

Normal clinical tests and ultrasound findings at the start indicated a low risk for these elite junior volleyball players to sustain jumper’s knee during three school years with intensive training and playing.

[37]

Patellar: patient supine with an extended knee.

Not described

Bilateral

Monitoring

Not described

The 20 clinically normal tendons with the normal US and PD sonography at inclusion lead to the structural tendon changes, whereas neovascularisation was developed in 12 tendons.

The clinical diagnosis of patellar tendinopathy is most often accompanied by neovascularisation in the area with structural tendon changes. The finding of neovessels might represent the worsening of the condition.

[38]

Achilles: Prone, and feet hanging over the table in a relaxed position

Not described

Bilateral

Predicting

A transverse scan was used to measure tendon thickness by maximum anteroposterior diameter at a neutral position of the talocrural joint. The tendon was considered a thickened tendon with a diameter greater than 6 mm.

65% of the symptomatic tendons had abnormal morphology on. The US and 68% of asymptomatic tendons had normal morphology. Baseline US findings did not anticipate the 1-year clinical outcome. No improvement in diagnostic qualities of US after the addition of color and power Doppler

In chronic Achilles tendinopathy, moderate correlation with clinical assessment on US and MRI. Association between Graded MRI appearance and clinical outcome, but no association with the US.

[18]

Patellar and Achilles: The ankle and knee flexed 90°.

Proximal to distal

Bilateral

Predicting

Tendons were considered abnormal, 2 to 5 cm proximal from the calcaneal insertion and of more than 1 mm to the normal distal part of the tendon.

During the preliminary examination, 11% of the Achilles tendon had abnormal findings in the US. it was observed that they had a 45% risk of developing symptoms of Achilles tendinosis. At the end of the season, only one of the players with normal tendons developed symptoms of tendinopathy.

For the first time, it is now credible to recognize risk factors for the development of serious tendon disorders in asymptomatic athletes.

[14]

Not described

Not described

Bilateral

Predicting

Not described

Development of hypoechoic area in seven normal patellar tendons at baseline with only two produced symptoms, there is no association between baseline ultrasound changes and symptoms at follow-up.

Management of patellar tendinopathy should not only rely upon ultrasonographic changes; assessment of the clinical features remains the foundation of significant management.

[39]

Not described

Not described

Bilateral

Predicting

Not described

During the study period, ultrasonographic changes were more likely to appear in males than females (P < 0.025), with more training hours per week (P < 0.01), while half (50%) of abnormal tendons in females became normal as observed on the US.

It was impossible to anticipate the future development or resolution of tendon symptoms by qualitative or quantitative analysis of baseline ultrasonographic images.

[40]

Patellar and quadriceps: supine, with slight knee flexion (20°)

Not described

Bilateral

Monitoring

The proximal, mid, and distal parts of the tendons

Ultrasound abnormalities were significantly associated with approximately a 3-fold increase [hazard ratio (HR) = 2.55, P = 0.004] in the hazard of developing pain in the Achilles tendon and patellar tendon (HR = 1.67, P = 0.042) over the year after the race.

The presence of ultrasonographic abnormalities is associated with increased development of pain in the Achilles and patellar tendons within 1 year of a marathon or half marathon.

[17]