Prospective study of change in patellar tendon abnormality on imaging and pain over a volleyball season

Objective

Patellar tendon injury, defined by tendon abnormality (TA) on imaging and by pain, is common among volleyball players, but little is known about change in this injury over a volleyball season. Increased activity in the season compared with the off season may result in the development of TA and/or pain. This study investigated the behaviour of TA and pain over a competitive volleyball season.

Methods

Tendon abnormality and pain were measured in 101 volleyball players at the beginning and end of a season. Pain was measured with the single leg decline squat test, which loads the patellar tendon, and TA was detected with ultrasound imaging. Hours of weekly activity were measured and compared during the season and the off season. The proportion of tendons that underwent development and resolution in TA and/or pain over the season was investigated.

Results

Hours of weekly activity was greater during the season than in the off season. Most of the tendons investigated (66.3%) did not undergo a change in TA or pain over the season. Tendon abnormality and/or pain developed in 16.6% of tendons and resolved in 11.2%.

Conclusions

The tendons of volleyball players respond variably to the increased load over the season. Change in TA and pain does not appear to be entirely dependent upon load.     

Neovascularization and pain in abnormal patellar tendons of active jumping athletes.

OBJECTIVE: The aim of this study was to investigate tendon pain in abnormal patellar tendons with and without neovascularization. STUDY DESIGN: Comparative design. SETTING: Multidisciplinary tendon study group at a competitive volleyball venue. PARTICIPANTS: One hundred eleven volleyball players volunteered to participate in the study. MAIN OUTCOME MEASURES: Subjects' patellar tendons were imaged with ultrasound, with and without Doppler. Tendons that were imaging abnormal were categorized according the presence of tendon neovascularization. Subjects completed 3 pain scales that examined function (Victorian Institute of Sport Assessment score, 100-point maximum), pain with tendon load (decline squat, visual analogue scale, 100-mm maximum), and maximum pain for the previous week (visual analogue scale, 100-mm maximum). A 1-tailed Mann-Whitney U test compared pain scores in abnormal tendons without neovascularization to abnormal tendons with neovascularization. RESULTS: Functional scores were lower (Victorian Institute of Sport score, median, 78; P = 0.045) and pain scores under tendon load were greater (decline squat pain, median, 19; P = 0.048) in subjects with abnormal tendons with neovascularization than subjects with abnormal tendons without neovascularization (Victorian Institute of Sport Assessment score, median, 87; decline squat pain, median, 0). CONCLUSIONS: This study indicates that the presence of neovascularization in abnormal patellar tendons is associated with greater tendon pain compared with abnormal tendons without neovascularization in active jumping athletes.     

Reduced ankle dorsiflexion range may increase the risk of patellar tendon injury among volleyball players.

Patellar tendon injury, a chronic overuse injury characterised by pain during tendon loading, is common in volleyball players and may profoundly restrict their ability to compete. This cross-sectional study investigated the association between performance factors and the presence of patellar tendon injury. These performance factors (sit and reach flexibility, ankle dorsiflexion range, jump height, ankle plantarflexor strength, years of volleyball competition and activity level) were measured in 113 male and female volleyball players. Patellar tendon health was determined by measures of pain and ultrasound imaging. The association between these performance factors and patellar tendon health (normal tendon, abnormal imaging without pain, abnormal imaging with pain) was investigated using analysis of variance. Only reduced ankle dorsiflexion range was associated with patellar tendinopathy (p<0.05). As coupling between ankle dorsiflexion and eccentric contraction of the calf muscle is important in absorbing lower limb force when landing from a jump, reduced ankle dorsiflexion range may increase the risk of patellar tendinopathy.     

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.

     

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.     

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.

     

MR imaging of patellar tendinitis.

To identify magnetic resonance (MR) imaging characteristics of normal patellar tendons and those affected by tendinitis, the authors evaluated MR images obtained in 10 healthy volunteers, in 50 patients who underwent MR imaging for evaluation of knee structures other than the patellar tendon, in 11 patients with patellar tendinitis, and in two athletes with patellar tendon injuries. Normal tendons had uniformly low signal intensity on T1-, T2-, and proton-density-weighted images and displayed distinct margins, and the anteroposterior (AP) diameter slightly increased proximally to distally. It was concluded that the AP diameter of a normal tendon, in its proximal portion, should not exceed 7 mm. In patellar tendinitis, the tendon showed increased signal intensity on T1-, T2-, and proton-density-weighted images and increased AP diameter proximally. The margins of affected tendons were indistinct, especially posterior to the thickened segment. In all groups studied, women had thicker proximal tendons than did men.     

Asymptomatic Achilles,patellar, and quadriceps tendinopathy: A longitudinal clinical and ultrasonographic study in elite fencers

Lower limb tendon changes detected at imaging are common among asymptomatic athletes. We aimed to prospectively assess the clinical status, tendon structure, and vascularity of lower limb tendons of elite fencers, and predict the risk of developing symptoms over time. Clinical examination, changes at ultrasonography (US), and Power Doppler (PD) flow of both the Achilles, patellar, and quadriceps tendon were assessed in 37 elite fencers in January 2007 and 3 years after. Two hundred and twenty‐two tendons were examined. At the last appointment, patellar tendons diagnosed as abnormal at baseline were more likely to develop symptoms than those normal at baseline (P < 0.05, Fisher's exact test), while US and PD abnormalities on Achilles and quadriceps tendons were no predictive for development of symptoms over years. A very low percentage of tendons diagnosed as normal at baseline (1.45%) showed US abnormalities at 3‐year follow‐up. In asymptomatic elite fencers, structural changes are relatively common at US and PD assessment of Achilles, quadriceps, and patellar tendons. It seems unlikely that additional PD investigations provide further information or change prognosis in patients with US diagnosis of tendinopathy.     

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.     

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.     

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.     

Patellar tendon–lateral femoral condyle friction syndrome: MR imaging in 42 patients

OBJECTIVE: To demonstrate the MR imaging findings that occur between the posterior inferolateral patellar tendon and the lateral femoral condyle in patients with chronic anterior and or lateral knee pain. PATIENTS AND DESIGN: A retrospective review of the MR images in 42 patients who presented with chronic anterior or lateral knee pain was performed by two musculoskeletal radiologists. In 15 patients, post-contrast images were available. RESULTS: Sagittal and axial imaging planes best demonstrated the patellar tendon and its relationship with the lateral femoral condyle. In 40 patients, there was obliteration of the fat planes and abnormal signal intensity in the lateral soft tissues of the inferior patellofemoral joint. Enhancement after administration of gadolinium was noted in all cases in which contrast was administered. Eighteen patients showed cystic changes in the soft tissues adjacent to the lateral femoral condyle in addition to fat plane obliteration. In two patients, only cystic changes were noted in the lateral soft tissues. Abnormal patellar alignment was noted in 37 patients. Patellar tendon pathology was seen in nine patients. CONCLUSION: In evaluating anterior knee symptoms, MR imaging allows identification of changes that may be related to patellar tendon-lateral femoral condyle friction syndrome and that should be distinguished from other causes of anterior or lateral knee pain.     

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.     

Patellar tendon length after anterior cruciate ligament reconstruction: a comparative magnetic resonance imaging study between patellar and hamstring tendon autografts

Patellar tendon shortening after anterior cruciate ligament reconstruction may be associated with anterior knee pain or patellofemoral arthritis. The present study was designed to compare postoperative changes in patellar tendon length after anterior cruciate ligament reconstruction between patellar tendon and hamstring tendon autograft. Magnetic resonance images of both knees (operated and healthy) and functional outcome were documented at least 1 year postoperatively in 16 patellar tendon harvested patients and in 32 hamstrings harvested patients. Patellar tendon length, patella length and Insall–Salvati ratio were measured. The operated knee values were compared to the respective values of the non-operated control knees. A significant 4.2 mm or 9.7% patellar tendon shortening in patellar tendon group and a non-significant 1.14 mm or 2.6% shortening in hamstrings group was detected. No significant difference was detected in terms of major shortening—patella baja—(6% for the patellar tendon group vs. 0% for the hamsting group). There was no significant difference in anterior knee problems between the two groups as evidenced by the Shelbourne score (94 for the patellar tendon group vs. 98 for the hamsting group). Harvesting of the patellar tendon for anterior cruciate ligament reconstruction resulted in a significant shortening of the remaining tendon. In contrast harvesting of the hamstring tendons did not affect significantly the patellar tendon length. However, the incidence of patella baja and overall functional outcome was not significantly different between the two groups. Paper presented at the 12th ESSKA 2000 Congress, Innsbruck, Austria, 2006 and also presented at the 5th Biennial ISAKOS Congress, Hollywood, FL, USA, 2005.     

Eccentric decline squat protocol offers superior results at 12 months compared with traditional eccentric protocol for patellar tendinopathy in volleyball players

Background: Conservative treatment of patellar tendinopathy has been minimally investigated. Effective validated treatment protocols are required.

Methods: This was a prospective randomised controlled trial of 17 elite volleyball players with clinically diagnosed and imaging confirmed patellar tendinopathy. Participants were randomly assigned to one of two treatment groups: a decline group and a step group. The decline group were required to perform single leg squats on a 25° decline board, exercising into tendon pain and progressing their exercises with load. The step group performed single leg squats on a 10 cm step, exercising without tendon pain and progressing their exercises with speed then load. All participants completed a 12 week intervention programme during their preseason. Outcome measures used were the Victorian Institute of Sport Assessment (VISA) score for knee function and 100 mm visual analogue scale (VAS) for tendon pain with activity. Measures were taken throughout the intervention period and at 12 months.

Results: Both groups had improved significantly from baseline at 12 weeks and 12 months. Analysis of the likelihood of a 20 point improvement in VISA score at 12 months revealed a greater likelihood of clinical improvements in the decline group than the step group. VAS scores at 12 months did not differ between the groups.

Conclusions: Both exercise protocols improved pain and sporting function in volleyball players over 12 months. This study indicates that the decline squat protocol offers greater clinical gains during a rehabilitation programme for patellar tendinopathy in athletes who continue to train and play with pain.

     

Anthropometry, physical performance, and ultrasound patellar tendon abnormality in elite junior basketball players: a cross-sectional study

OBJECTIVE: Patellar tendinopathy has been reported to be associated with many intrinsic risk factors. Few have been fully investigated. This cross-sectional study examined the anthropometric and physical performance results of elite junior basketball players with normal or abnormal patellar tendons to see if any measures were associated with changes in tendon morphology. METHODS: Agility, leg strength, endurance, and flexibility were measured in 71 male and 64 female players. A blinded radiologist ultrasonographically examined their patellar tendons and athletes were grouped as having normal or abnormal tendons. One-way ANOVA was used to test for differences in anthropometric and physical performance data for athletes whose tendons were normal or abnormal (unilateral or bilateral tendinopathy) on ultrasound. RESULTS: Results show that females with abnormalities in their tendons had a significantly better vertical jump (50.9+/-6.8 cm) than those with normal tendons (46.1+/-5.4 cm) (p = 0.02). This was not found in males. In males, the mean sit and reach in those with normal tendons (13.2+/-6.7 cm) was greater (p<0.03) than in unilateral tendinopathy (10.3+/-6.2 cm) or in bilateral tendinopathy (7.8+/-8.3 cm). In females, those with normal tendons (13.3+/-4.8 cm) and bilateral tendinopathy (15.8+/-6.2 cm) were distinctly different from those with unilateral tendinopathy (7.9+/-6.6 cm). CONCLUSION: Flexibility and vertical jump ability are associated with patellar tendinopathy and the findings warrant consideration when managing young, jumping athletes.     

Peroneal tendon pathology: Pre- and post-operative high resolution US and MR imaging

Peroneal tendon pathology is an important cause of lateral ankle pain and instability. Typical peroneal tendon disorders include tendinitis, tenosynovitis, partial and full thickness tendon tears, peroneal retinacular injuries, and tendon subluxations and dislocations. Surgery is usually indicated when conservative treatment fails. Familiarity with the peroneal tendon surgeries and expected postoperative imaging findings is essential for accurate assessment and to avoid diagnostic pitfalls. Cross-sectional imaging, especially ultrasound and MRI provide accurate pre-operative and post-operative evaluation of the peroneal tendon pathology. In this review article, the normal anatomy, clinical presentation, imaging features, pitfalls and commonly performed surgical treatments for peroneal tendon abnormalities will be reviewed. The role of dynamic ultrasound and kinematic MRI for the evaluation of peroneal tendons will be discussed. Normal and abnormal postsurgical imaging appearances will be illustrated.     

Reproducibility and clinical utility of tendon palpation to detect patellar tendinopathy in young basketball players. Victorian Institute of Sport tendon study group

BACKGROUND: Palpation is an important clinical test for jumper's knee. OBJECTIVES: To (a) test the reproducibility of palpation tenderness, (b) evaluate the sensitivity and specificity of palpation in subjects with clinical symptoms of jumper's knee, and (c) determine whether tenderness to palpation may serve as a useful screening test for patellar tendinopathy. The yardstick for diagnosis of patellar tendinopathy was ultrasonographic abnormality. METHODS: In 326 junior symptomatic and asymptomatic athletes' tendons, palpation was performed by a single examiner before ultrasonographic examination by a certified ultrasound radiologist. In 58 tendons, palpation was performed twice to test reliability. Tenderness to palpation was scored on a scale from 0 to 3 where 0 represented no pain, and 1, 2, and 3 represented mild, moderate, and severe tenderness respectively. RESULTS: Patellar tendon palpation was a reliable examination for a single examiner (Pearson r = 0.82). In symptomatic tendons, the positive predictive value of palpation was 68%. As a screening examination in asymptomatic subjects, the positive predictive value of tendon palpation was 36-38%. Moderate and severe palpation tenderness were better predictors of ultrasonographic tendon pathology than absent or mild tenderness (p<0.001). Tender and symptomatic tendons were more likely to have ultrasound abnormality than tenderness alone (p<0.01). CONCLUSIONS: In this age group, palpation is a reliable test but it is not cost effective in detecting patellar tendinopathy in a preparticipation examination. In symptomatic tendons, palpation is a moderately sensitive but not specific test. Mild tenderness in the patellar tendons in asymptomatic jumping athletes should be considered normal.     

Feasibility and reliability of pain pressure threshold measurements in patellar tendinopathy

Patellar tendinopathy is a common and often difficult to treat overuse injury which is characterized by activity-related anterior knee and focal palpation tenderness of the patellar tendon. The clinical diagnosis is mainly based on clinical examination, in which the yardstick is a non-standardized manual palpation. To standardize this palpation procedure the use of an algometer seems applicable. The purpose of this study was to investigate the feasibility and reliability of the algometer in patellar tendinopathy. A cross sectional study was carried out.The algometer was applied to the patellar tendon in 20 asymptomatic volleyball players to measure the ‘normal’ pressure pain threshold. The inter-rater reliability was analyzed in 54 athletes with symptomatic patellar tendinopathy, the intra-rater reliability was analyzed in 48 athletes with symptomatic patellar tendinopathy. During the procedure difficulties were described, the SEM, intra class correlations and limits of agreement were determined using the Bland and Altman method. The feasibility of the algometer is adequate. The PPT of asymptomatic athletes differs significantly (p < .001) from athletes with a diagnosis of patellar tendinopathy. The inter-rater (ICC 0.93) and intra-rater (ICC 0.60) reliability of the pain pressure threshold are adequate to moderate. Although further research is warranted PPT algometry seems to be a feasible, reliable and useful tool in the diagnosis and treatment evaluation of athletes with patellar tendinopathy.