Ultrasonography in the detection of partial patellar ligament ruptures (jumper's knee)

Partial Patellar Tendon Tears in Athletes: A Systematic Review of Treatment Options, Outcomes, and Return to Sport

Introduction

Partial patellar tendon tears (PPTTs) are overuse injuries in sports with frequent jumping, such as basketball and volleyball. There are several treatment options, including both operative and non-operative modalities. Current literature is largely focused broadly on patellar tendinopathy; however, there are few studies which specifically evaluate treatment outcomes for PPTTs.

Objective

To systematically review the literature on treatment options, clinical outcomes, and return to sport (RTS) in athletes with a PPTT.

Methods

PubMed, Embase, and Cochrane were searched through May 1st, 2023 for studies reporting treatment outcomes in athletes with partial patellar tendon tears. Data was extracted on the following topics: treatment modalities, surgical failures/reoperations, surgical complications, RTS, and postoperative time to RTS.

Results

The review covers 11 studies with 454 athletes: 343 males (86.2%) and 55 females (13.8%). The average age was 25.8 years, ranging from 15 to 55 years. 169 patients (37.2%) received only non-operative treatments, while 295 (65.0%) underwent surgery. 267 patients (92.1%) returned to sports after 3.9 months of treatment. The average follow-up was 55.8 months.

Conclusion

Our review of current literature on PPTTs in athletes illustrates over 90% return to sport following either conservative or surgical treatment. There is currently little data that directly compares the treatment options to establish an evidence-based "gold-standard" treatment plan. The data we present suggests that current treatment options are satisfactory but would benefit from future study.

Proximal patellar tendon abnormalities on ultrasound can develop in male adolescent basketball players: A longitudinal study

INTRODUCTION

Adolescent patellar tendinopathy is reported but the pubertal-stage of onset of abnormal tendon structure has not been investigated with grayscale ultrasound.

AIMS

To investigate abnormal tendon structure using grayscale ultrasound and its association with pubertal-stage and pain.

METHODS

Forty-three male basketball players aged 13.7 years (SD 1.0) had patellar tendon ultrasound scans every 6 months for 2.5 years. Pubertal-stage (peak height velocity) was calculated using the Mirwauld equation. Tendon thickness, hypoechogenicity and pain during single leg decline squat (SLDS) were recorded. Tendons were classified: hypoechoic, normal or immature.

RESULTS

Two tendons were hypoechoic at baseline. Six developed hypoechogenicity over 2.5 years (eight tendons [9%], six participants [14%]), all in peri and post-PHV players. Twenty-six tendons (17 participants) were classified as immature during the study. Hypoechoic tendons were thicker (5.3 mm SD 1.2) than normal (3.9 mm SD 0.7) tendons (p < 0.001). There was no difference in the proportion of participants reporting pain during SLDS in the hypoechoic (N = 3) and normal (N = 11) groups (p = 0.33), or in hypoechoic tendon thickness between those reporting pain (6.5 mm, SD 1.7) or not (5.2 mm, SD 0.9, p = 0.17).

DISCUSSION

This study using grayscale ultrasound found that basketball players with hypoechogenicity were peri or post-PHV. Abnormal structure was not always associated with pain.

High-Intensity Resistance Training Does Not Produce Immediate Ultrasonographic Changes in Muscle Tendons

Background:

Chronic overload injuries to tendons can be visualized using ultrasonography, with characteristics such as tendon thickening and darkening.

Purpose:

To investigate whether these characteristics are evident in the patellar and Achilles tendons immediately after 1 session of high-intensity resistance training.

Study Design:

Controlled laboratory study.

Methods:

A total of 18 volunteers were randomized to an experimental group (n = 10) and a sham group (n = 8). The experimental group performed 5 circuits at maximum effort consisting of 5 weighted front squats, 10 box jumps (60/50 cm), and 15 double-under jump-rope jumps. The sham group performed a similar circuit consisting of 5 weighted shoulder presses, 10 push-ups, and 15 weighted biceps curls. Ultrasonograms were obtained before and after exercise, for a total of 30 minutes at intervals of 2.5 minutes for the first 10 minutes and 5 minutes for the remaining time. Tendon thickness and tendon matrix signals were measured. Statistics were performed using repeated-measures mixed analysis of variance (ANOVA).

Results:

Tendon thickness did not increase significantly over 30 minutes after both circuits. The mean grayscale value for the patellar and Achilles tendons increased for both the experimental and the sham groups. ANOVA showed that the experimental group was not a significant explanatory variable; however, the increased work of both groups was. A post hoc analysis found that the maximum increase in the tendon signal was a grayscale value of 10.8 for the patellar tendon (99.4% CI, 3.7-17.9; P = .002).

Conclusion:

This trial failed to reproduce an earlier study in which tendon thickness increased after high-intensity training. The tendons produced a hyperechoic signal after high-intensity resistance training, regardless of loading to the tendon. Chronic overload characteristics on ultrasonography were not evident immediately after acute loading of tendons.

Clinical Relevance:

There is a need for prognostic and diagnostic markers of tendinopathy especially because of the protracted course of subclinical development of an injury. This study assessed whether clinical findings for a chronic overload injury can be detected during acute overloading.

Alterations in mechanical properties of the patellar tendon is associated with pain in athletes with patellar tendinopathy

PURPOSE

To compare tendon strain and stiffness between athletes with patellar tendinopathy and healthy controls, and explore whether the intensity of pain and dysfunction were related to the mechanical properties of the tendon.

METHODS

Thirty-four male athletes with patellar tendinopathy and 13 healthy controls matched by age and activity levels were recruited. The in vivo mechanical properties of the patellar tendon were examined by ultrasonography and dynamometry. In subjects with patellar tendinopathy, the intensities of self-perceived pain (maximal pain in the past 7 days and pain during a single-legged declined-squat test) using the visual analogue scale and the assessment of functional disability using the Victorian Institute of Sport Assessment-patellar questionnaire, were collected.

RESULTS

In subjects with patellar tendinopathy, tendon strain was significantly reduced by 22% (8.9 ± 3.7 vs. 14.3 ± 4.7%, P = 0.005) when compared with healthy controls. There was no significant group difference in tendon stiffness (P = 0.27). Significant negative correlations between tendon strain and the maximal self-perceived pain over 7 days (r = -0.37, P = 0.03), and pain during a single-legged declined-squat test (r = -0.37, P = 0.03) were detected. A trend of significant positive correlation was found between tendon stiffness and pain during a single-legged declined-squat test (r = 0.30, P = 0.09).

CONCLUSION

Our findings show that tendon strain is reduced in athletes with patellar tendinopathy, and a lower tendon strain is associated with a greater magnitude of pain perceived.

Ultrasound in sports medicine: relevance of emerging techniques to clinical care of athletes

The applications of ultrasound in managing the clinical care of athletes have been expanding over the past decade. This review provides an analysis of the research that has been published regarding the use of ultrasound in athletes and focuses on how these emerging techniques can impact the clinical management of athletes by sports medicine physicians. Electronic database literature searches were performed using the subject terms 'ultrasound' and 'athletes' from the years 2003 to 2012. The following databases were searched: PubMed, Web of Science, Cochrane Library, CINAHL, and SPORTDiscus™. The search produced 617 articles in total, with a predominance of articles focused on cardiac and musculoskeletal ultrasound. 266 of the studies involved application of ultrasound in evaluating the cardiovascular properties of athletes, and 151 studies involved musculoskeletal ultrasound. Other applications of ultrasound included abdominal, vascular, bone density and volume status. New techniques in echocardiography have made significant contributions to the understanding of the physiological changes that occur in the athlete's heart in response to the haemodynamic stress associated with different types of activity. The likely application of these techniques will be in managing athletes with hypertrophic cardiomyopathy, and the techniques are near ready for application into clinical practice. These techniques are highly specialized, however, and will require referral to dedicated laboratories to influence the clinical management of athletes. Investigation of aortic root pathology and pulmonary vascular haemodynamics are also emerging, but will require additional studies with larger numbers and outcomes analysis to validate their clinical utility. Some of these techniques are relatively simple, and thus hold the potential to enter clinical management in a point-of-care fashion. Musculoskeletal ultrasound has demonstrated a number of diagnostic and therapeutic techniques applicable to pathology of the shoulder, elbow, wrist, hand, hip, knee and ankle. These techniques have been applied mainly to the management of impingement syndromes, tendinopathies and arthritis. Many of these techniques have been validated and have entered clinical practice, while more recently developed techniques (such as dynamic ultrasound and platelet-rich plasma injections) will require further research to verify efficacy. Research in musculoskeletal ultrasound has also been helpful in identifying risk factors for injury and, thus, serving as a focus for developing interventions. Research in abdominal ultrasound has investigated the potential role of ultrasound imaging in assessing splenomegaly in athletes with mononucleosis, in an attempt to inform decisions and policies regarding return to play. Future research will have to demonstrate a reduction in adverse events in order to justify the application of such a technique into policy. The role of ultrasound in assessing groin pain and abdominal pain in ultraendurance athletes has also been investigated, providing promising areas of focus for the development of treatment interventions and physical therapy. Finally, preliminary research has also identified the role of ultrasound in addressing vascular disease, bone density and volume status in athletes. The potential applications of ultrasound in athletes are broad, and continuing research, including larger outcome studies, will be required to establish the clinical utility of these techniques in the care of athletes.

Chronic tendinopathy tissue pathology, pain mechanisms, and etiology with a special focus on inflammation

Continuing progress in research in molecular biology and biomechanics has provided considerable new information and has given rise to new hypotheses in chronic tendinopathy. Overloading is still, however, crucial in the development of tendinopathy. Most of the histologic findings in tendinopathy represent chronic degeneration, regeneration, and microtears of the tendinous tissue. The prevailing opinion is that no histological evidence of acute inflammation has been documented, but in newer studies using immunohistochemistry and flow cytometry inflammatory cells have been detected. The existing data indicate that the initiators of the tendinopathic pathway include many proinflammatory agents (e.g. cytokines, prostaglandins, different growth factors, and neuropetides). Because of the complex interaction between the classic proinflammatory agents and the neuropeptides, it seems impossible and somewhat irrelevant to distinguish sharply between chemical and neurogenic inflammation. Furthermore, glucocorticoids are, at the moment, the most effective treatment in tendinopathy with regard to reduction of pain, tendon thickness, and neovascularization. This review indicates - despite a great deal of uncertainty regarding the concepts - that an inflammatory process may be related not only to the development of tendinopathy but also chronic tendinopathy. More attention should be directed towards the "tendinitis myth" in the future.

The patellar tendinopathy in athletes: a sonographic grading correlated to prognosis and therapy

The purpose of this study is to determine in the athletes a sonographic grading of the patellar tendinopathy correlated to prognosis and therapy. The 298 patellar overuse tendinopathies were divided in four grades according to the extension of the injured area of the tendon in the axial sonograms. Grades 1, 2, and 3 were managed with medical and physical therapy. A surgical treatment was performed in grade 4 and in grades 1, 2, and 3 tendinopathies not responding to our conservative therapy. There were 21.8% injuries in grade 1 (100% responding; prognosis 20 days), 61.2% injuries in grade 2 (94.5% responding; prognosis 40 days), 16.4% injuries in grade 3 (85.7% responding; prognosis 90 days), and 0.6% injuries in grade 4. The sonographic study is fundamental to characterize adequately the patellar tendinopathy. The conservative therapy is the first option for grades 1, 2, and 3 as it determines a complete healing in most of cases.

Quadriceps tendinosis and patellar tendinosis in professional beach volleyball players: sonographic findings in correlation with clinical symptoms

The purpose was to assess quadriceps and patellar tendinosis in professional beach volleyball players and to correlate ultrasound findings with clinical symptoms. During a grand-slam beach volleyball tournaments all 202 athletes (100 men and 102 women) were invited to participate at this study. Sixty-one athletes (38 male, mean age 29.6, 23 female, mean age 27.1) were included. The dominant leg was right in 51 (84%) and left in ten athletes (16%). Lysholm knee score and pain during the game was assessed using a visual analogue scale. Sonography of the quadriceps tendon and the patellar tendon was performed by a blinded sonographer. Sonographic findings were compared between both legs and correlated to clinical findings using a regression analysis. Quadriceps tendinosis was diagnosed in 13 (21%, dominant leg)/21 (34%, non-dominant leg), patellar tendinosis in 13(21%)/18(30%). Only sonographic findings at the quadriceps tendon were significantly associated with pain: thickness of the quadriceps tendon (mean diameter 6.9 mm/7.1 mm, significant for both legs P = 0.011/P = 0.030), abnormal echo texture (11/16; P = 0.001/P = 0.228), areas with positive power Doppler signals (mean number 0.3/0.4; P = 0.049/0.346), calcifications (mean number: 0.9/1.1; P = 0.021/0.864). A relationship between findings at patellar tendon was not found. Quadriceps tendinosis is as common as patellar tendinosis in professional beach volleyball players. Thickening and structure alteration of the quadriceps tendon is associated with anterior knee pain during beach volleyball.

Normal clinical and ultrasound findings indicate a low risk to sustain jumper's knee patellar tendinopathy: a longitudinal study on Swedish elite junior volleyball players

BACKGROUND

Jumper's knee patellar tendinopathy is well known to be a common and difficult injury in volleyball. Knowledge about its aetiology and pathogenesis is sparse.

OBJECTIVE

To prospectively follow clinical status, tendon structure and vascularity in elite junior volleyball players.

METHODS

22 volleyball players (44 patellar tendons) beginning their first grade at the Swedish National Centre for high school volleyball were continuously evaluated clinically and by ultrasonography (US) and power Doppler (PD) over the 3 school years.

RESULTS

At inclusion, there were 44 tendons being assessed. Jumper's knee was diagnosed clinically in eight patellar tendons (seven of eight had structural changes and vascularity on US+PD). There were 27 normal (clinical and US+PD) tendons. At 3 years, there were 36 tendons still being assessed. Four individuals (eight tendons) had been excluded. Jumper's knee had developed in 2 of 25 (2 were excluded) tendons that were normal (clinical and US+PD) at inclusion. Jumper's knee (clinical and US+PD) was also present in six tendons.

CONCLUSIONS

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.

Ultrasonography of the lower extremity

Ultrasonography is a useful imaging tool for various soft tissue and joint pathologies affecting the lower extremity. This article reviews the normal sonographic appearance of muscles, tendons, ligaments, nerves, bone, and cartilage. The ultrasound imaging appearance of various pathologic conditions affecting the hip, thigh, knee, lower leg, ankle,and foot are illustrated. The advantages of ultrasonography are highlighted.

Ultrasound appearance of tendon tears. Part 2: lower extremity and myotendinous tears

Traumatic tears of the musculotendinous complex at the lower limb are common in clinical practice but can be difficult to detect and to evaluate because of swelling and pain that can limit proper physical examination. They can affect sedentary subjects or active sports participants involved in amateur or professional activities. In the first group tendons are more commonly affected, while myotendinous tears are common in sports players. The aims of this review article are to review the aetiology and pathomechanism of the most common ruptures affecting the tendons and the main myotendinous junctions of the lower extremity and to describe their ultrasound findings as well as to correlate ultrasound appearance with that of the other imaging modalities.

Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations

Formerly known as 'jumper's knee', patellar tendinopathy gives rise to considerable functional deficit and disability in recreational as well as professional athletes. It can interfere with their performance, often perseveres throughout the sporting career and may be the primary cause to end it. The diagnosis of patellar tendinopathy is primarily a clinical one but new imaging techniques, such as Doppler ultrasonography, may provide additional diagnostic value. Current therapeutic protocols are characterised by wide variability ensuing from anecdotal experience rather than evidence. Moreover, numerous reports in recent years have shattered previous doctrines and dogmatic belief on tendon overuse. Histopathological and biochemical evidence has indicated that the underlying pathology of tendinopathy is not an inflammatory tendinitis but a degenerative tendinosis. Consequently, pain in chronic patellar tendinopathy is not inflammatory in nature, but its exact origin remains unexplained. In pursuit of pathology- and evidence-based management, conservative therapy should be shifted from anti-inflammatory strategies towards a complete rehabilitation with eccentric tendon strengthening as a key element. If conservative management fails, surgery is opted for. However, considering the heterogeneity of surgical procedures and the absence of randomised studies, no conclusive evidence can be drawn from the literature regarding the effectiveness of surgical treatment for patellar tendinopathy. Parallel with the improved knowledge on the pathophysiology and pain mechanisms in patellar tendinopathy, new treatment strategies are expected to emerge in the near future.

Performance characteristics of volleyball players with patellar tendinopathy

BACKGROUND

Patellar tendinopathy is assumed to result from chronic tendon overload. There may be a relationship between tendon pain and jumping ability.

HYPOTHESIS

There is no difference in performance characteristics between volleyball players with patellar tendinopathy and those without.

STUDY DESIGN

Prospective cohort study.

METHOD

We examined the performance of the leg extensor apparatus in high-level male volleyball players with patellar tendinopathy (N = 24) compared with a control group (N = 23) without knee symptoms. The testing program consisted of different jump tests with and without added load, and a composite jump score was calculated to reflect overall performance.

RESULTS

The groups were similar in age, height, and playing experience, but the patellar tendinopathy group did more specific strength training and had greater body weight. They scored significantly higher than the control group on the composite jump score (50.3 versus 39.2), and significant differences were also observed for work done in the drop-jump and average force and power in the standing jumps with half- and full-body weight loads.

CONCLUSIONS

Greater body weight, more weight training, and better jumping performance may increase susceptibility to patellar tendinopathy in volleyball players.

Review article: diagnostic ultrasonography: applications in orthopaedic surgery

Diagnostic ultrasonography of musculoskeletal diseases in the United States has been used most often for detection of rotator cuff tears or developmental dysplasia of the hip. Diagnostic ultrasonography also is useful in imaging the periarticular soft tissues about the knee, hip, ankle, occult pediatric fractures, muscle injury, bone healing, and foreign bodies. Recent technologic improvements have made this imaging modality increasingly more accurate while providing significant benefits over traditional modalities such as magnetic resonance imaging, particularly regarding cost, patient satisfaction, and ease of usage. Increasing use in the future of diagnostic ultrasonography for musculoskeletal conditions is likely as acceptance grows. This review focuses on recent, practical applications of diagnostic ultrasonography of the musculoskeletal system.

Ultrasound and Power Doppler findings in jumper's knee - preliminary observations

OBJECTIVE

to examine a group of high risk athletes, for signs of inflammation in jumper's knee (JK) by gray-scale ultrasonography (US) and color/Power Doppler findings in JK.

SUBJECTS AND METHODS

eighteen high-elite basketball players participated in the investigation after a match. Seven players were examined by ultrasound before the match as well. The players were clinically examined for signs of JK and filled in a questionnaire concerning previous and present knee symptoms.

RESULTS

clinical signs of JK were found in 13 knees. Of these knees, ten had hypoechoic areas and six had Power Doppler flow. Four players reported symptoms of JK and clinical examination suspected the same. Three of them had both hypoechoic areas and Power Doppler flow. Fourteen players were asymptomatic at the time of examination but both hypoechoic areas and Power Doppler flow was found in the patellar tendons of four players. No correlation was found between clinical findings, symptoms of JK and US findings - including Power Doppler. The risk of type II error in this material is considerable.

CONCLUSION

an association between gray-scale US and color/Power Doppler was found in JK which may suggest an inflammatory component to be a part of the pathogenesis of JK.

Current concepts in imaging of tendinopathy

With the rising popularity of recreational sports, radiologists are being asked to image tendons with increasing frequency. Recognition of the critical link tendons provide between muscle and bone has also led to a better understanding of the processes leading to tendon damage. While plain radiography and CT have only a limited role to play in the diagnosis of tendon abnormality, the improvements in ultrasound and MRI technology mean that tendons can now be demonstrated in exquisite detail and previously undetectable abnormalities are readily demonstrated. This article reviews the structure and pathological processes affecting tendons and discusses the role of imaging in their assessment with an emphasis on ultrasound and MRI.

Musculoskeletal ultrasonography

This article introduces ultrasound in the evaluation of the musculoskeletal system. An emphasis is placed on currently accepted applications, and examples are included to illustrate pathologic conditions. Topics of current investigations are also presented. The efficacy of ultrasound, combined with its inaccessibility and low cost, has earned it an important role in musculoskeletal imaging.

Relationship between symptoms of jumper's knee and the ultrasound characteristics of the patellar tendon among high level male volleyball players

This study assessed the ultrasound characteristics of the patellar tendon in two groups of volleyball players, one group without knee symptoms and one group with symptoms of jumper's knee. Of 47 male elite players, 25 were diagnosed to have current and seven to have had previous symptoms of jumper's knee, as determined by clinical examination. Since some players had bilateral problems, there were 34 knees with current problems and nine with previous problems. Seven of the 30 knees with a clinical diagnosis of jumper's knee in the patellar tendon had normal ultrasound findings, and ultrasound changes believed to be associated with jumper's knee (tendon thickening, echo signal changes, irregular paratenon appearance) were observed in 12 of 51 knees without symptoms. Specific ultrasound findings such as paratenon changes, hypoechoic zones or pathological tendon thickness proximally did not correlate significantly with the degree or the duration of symptoms. This study suggests that the specificity and sensitivity of ultrasonography is low in the evaluation of patients with mild symptoms of jumper's knee.

Characteristics of the leg extensors in male volleyball players with jumper's knee

The aim of the present study was to characterize the performance ability of the leg extensor apparatus in a group of athletes with jumper's knee and to compare the results with those of a matched control group without knee symptoms. Patient and control groups (12 players in each) were selected from a population of 141 well-trained male Norwegian volleyball players, of which 55 (39%) satisfied the diagnostic criteria for jumper's knee. The testing program consisted of a standing jump, a countermovement jump, a 15-second rebound jump test, a standing jump with a 20-kg load, and a standing jump with a load corresponding to one-half of the subject's body weight. Jump height and power were measured using a contact mat connected to an electronic timer. The test results of the patient group were significantly higher than those of the control group for the countermovement jump (15% increase), power during rebound jump (41%), work done in standing jump (12%) and countermovement jump (22%), and the difference between countermovement jump and standing jump (effect of adding eccentric component). Athletes with jumper's knee demonstrated better performance in jump tests than uninjured athletes, particularly in ballistic jumps involving eccentric force generation.

[Ultrasound follow-up of experimental partial Achilles tendon rupture]

We performed surgically an experimental partial Achilles tendon dissection on 28 New Zealand white rabbits. The changes in the healing process were sonographically followed and documentated in short periods of time for 2 months. The sonographically detectable changes during the healing process underlie certain rules. The changes in sonography can be explained by the histopathology with respect to the theoretics of ultrasound physics. Hematomas and the fibrous scars can be followed closely with sonography. Sonography is a method of high value in the diagnosis of partial and complete tendon tears and with respect to certain limits in the follow-up of the healing process, too. Certain limits in the evaluation of tendon injuries and their follow-up by sonography remain.

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.

Ultrasonography of chronic tendon injuries in the groin

Ultrasonography was used in the diagnosis of 36 patients with chronic groin pain localized to the tendons of the rectus abdominis, rectus femoris, adductor muscles, hamstring muscles, and the gluteal muscles. Abnormal findings, such as focal sonolucent areas and discontinuity of tendon fibers, that are indicative of nonhealed partial ruptures were found in 28 patients. These findings differed clearly from the asymptomatic contralateral side, which was used for comparison. The abnormalities were located in three different sites: at the tendon insertion, within the tendon, and at the tendomuscular junction. Ten patients were treated surgically and the findings at surgery correlated well with the ultrasonographic findings of partial tendon tears: 9 were true-positive and 1 was a true-negative. Ultrasonography appears to be a valuable method in the diagnosis of chronic groin pain.

Partial rupture of the patellar ligament

Eighty-one patients with 91 partial ruptures of the patellar ligament verified by ultrasonography were treated conservatively with a standardized training program based on the principles of eccentric loading. The partial ruptures were quantified by measuring the length of the hypoechoic lesion using ultrasonography in longitudinal projection. The partial ruptures were then divided into three groups: Grade I (less than 10 mm), Grade II (10 to 20 mm), and Grade III (greater than 20 mm). The results after the training program were significantly better in Grade I ruptures than in Grades II and III. The overall need for surgery was 29.6%: highest in Grade III ruptures (38.5%) and lowest in Grade I ruptures (6.6%). The outcome of conservative management, as well as the need for surgery of partial ruptures of the patellar ligament, may to some extent be predicted by the use of ultrasonography.