Risk Factors For Patellar Tendinopathy Research Articles

A Review of Patellar Tendinopathy in Athletes Involved in Jumping Sports.

This review article discusses the anatomy and histopathology of the patellar tendon, as well as the risk factors and common interventions for patellar tendinopathy (PT) with a view to guide clinicians in treating athletes with patellar tendon pain. PT, or jumper's knee, refers to a chronic injury to the patellar tendon that affects athletes who engage in jumping and explosive movements. The condition is characterized by degeneration and disorganization of the collagen fibers in the tendon, an increase in mucoid ground substance, and fibroblast proliferation. Risk factors for patellar tendinopathy include participation in jumping sports, a greater counter-movement jump height, and training on hard surfaces. Nonoperative treatments for patellar tendinopathy include relative rest, stretching and strengthening exercises, and correction of biomechanical abnormalities. Surgery and other procedures, such as extracorporeal shockwave therapy(ESWT) and injection therapies, may be considered for patients who do not respond to conservative measures.

Longitudinal Evidence for High-Level Patellar Tendon Strain as a Risk Factor for Tendinopathy in Adolescent Athletes

BackgroundHigh tendon strain leads to sub-rupture fatigue damage and net-catabolic signaling upon repetitive loading. While high levels of tendon strain occur in adolescent athletes at risk for tendinopathy, a direct association has not yet been established. Therefore, in this prospective longitudinal study, we examined the hypothesis that adolescent athletes who develop patellar tendon pain have shown increased levels of strain in advance.MethodsIn 44 adolescent athletes (12–17 years old), patellar tendon mechanical properties were measured using ultrasonography and inverse dynamics at four time points during a season. Fourteen athletes developed clinically relevant tendon pain (SYM; i.e., reduction of the VISA-P score of at least 13 points), while 23 remained asymptomatic (ASYM; VISA-P score of > 87 points). Seven cases did not fall into one of these categories and were excluded. Tendon mechanical properties of SYM in the session before the development of symptoms were compared to a randomly selected session in ASYM.ResultsTendon strain was significantly higher in SYM compared to ASYM (p = 0.03). The risk ratio for developing symptoms was 2.3-fold higher in athletes with tendon strain ≥9% (p = 0.026). While there was no clear evidence for systematic differences of the force applied to the tendon or tendon stiffness between SYM and ASYM (p > 0.05), subgroup analysis indicated that tendon force increased prior to the development of symptoms only in SYM (p = 0.034).DiscussioThe study provides novel longitudinal evidence that high tendon strain could be an important risk factor for patellar tendinopathy in adolescent athletes. We suggest that inadequate adaptation of tendon stiffness to increases in muscle strength may occur if adolescent athletes are subject to mechanical loading which does not provide effective tendon stimulation.

Impact of Patellar Tendinopathy on Player Performance in the National Basketball Association.

Background:The extent to which patellar tendinopathy affects National Basketball Association (NBA) athletes has not been thoroughly elucidated.Purpose:To assess the impact patellar tendinopathy has on workload, player performance, and career longevity in NBA athletes.Study Design:Cohort study; Level of evidence, 3.Methods:NBA players diagnosed with patellar tendinopathy between the 2000-2001 and 2018-2019 seasons were identified through publicly available data. Characteristics, return to play (RTP), player statistics, and workload data were compiled. The season of diagnosis was set as the index year, and the statistical analysis compared post- versus preindex data acutely and in the long term, both within the injured cohort and with a matched healthy NBA control cohort.Results:A total of 46 NBA athletes were included in the tendinopathy group; all 46 players returned to the NBA after their diagnosis. Compared with controls, the tendinopathy cohort had longer careers (10.50 ± 4.32 vs 7.18 ± 5.28 seasons; P < .001) and played more seasons after return from injury (4.26 ± 2.46 vs 2.58 ± 3.07 seasons; P = .001). Risk factors for patellar tendinopathy included increased workload before injury (games started, 45.83 ± 28.67 vs 25.01 ± 29.77; P < .001) and time played during the season (1951.21 ± 702.09 vs 1153.54 ± 851.05 minutes; P < .001) and during games (28.71 ± 6.81 vs 19.88 ± 9.36 minutes per game; P < .001). Players with increased productivity as measured by player efficiency rating (PER) were more likely to develop patellar tendinopathy compared with healthy controls (15.65 ± 4.30 vs 12.76 ± 5.27; P = .003). When comparing metrics from 1 year preinjury, there was a decrease in games started at 1 year postinjury (−12.42 ± 32.38 starts; P = .028) and total time played (−461.53 ± 751.42 minutes; P = .001); however, PER at 1 and 3 years after injury was unaffected compared with corresponding preinjury statistics.Conclusion:NBA players with a higher PER and significantly more playing time were more likely to be diagnosed with patellar tendinopathy. Player performance was not affected by the diagnosis of patellar tendinopathy, and athletes were able to RTP without any impact on career longevity.

Association of COA1 with Patellar Tendonitis: A Genome-wide Association Analysis.

It is unknown why some athletes develop patellar tendinopathy and others do not, even when accounting for similar workloads between individuals. Genetic differences between these two populations may be a contributing factor. The purpose of this work was to screen the entire genome for genetic markers associated with patellar tendinopathy. Genome-wide association (GWA) analyses were performed utilizing data from the Kaiser Permanente Research Board (KPRB) and the UK Biobank. Patellar tendinopathy cases were identified based on electronic health records from KPRB and UK Biobank. GWA analyses from both cohorts were tested for patellar tendinopathy using a logistic regression model adjusting for sex, height, weight, age, and race/ethnicity using allele counts for single nucleotide polymorphisms. The data from the two GWA studies (KPRB and UK Biobank) were combined in a meta-analysis. There were a total of 1670 cases of patellar tendinopathy and 293,866 controls within the two cohorts. Two single nucleotide polymorphisms located in the intron of the cytochrome c oxidase assembly factor 1 (COA1) gene showed a genome-wide significant association in the meta-analysis. Genetic markers in COA1 seem to be associated with patellar tendinopathy and are potential risk factors for patellar tendinopathy that deserve further validation regarding molecular mechanisms.

Patellar mobility and lower limb kinematics during functional activities in individuals with and without patellar tendinopathy

Study designCase-control. ObjectiveTo examine whether patients with patellar tendinopathy (PT) display greater patellar mobility and different lower body kinematics than patients without PT. BackgroundPT is a common overuse condition of the patellar tendon that can cause pain and impair function. Subjects with overuse knee problems display different hip and knee functional mechanics, specifically valgus collapse. Patellar hypermobility has not been specifically studied as a possible risk factor for PT. Methods11 patients with PT and 11 controls without PT, age 18 to 40, were studied. Using a patellofemoral arthrometer (PFA), maximal lateral and medial patellar displacement was measured. 3-D motion analysis was performed to determine lower extremity joint motions during single-leg step down and drop vertical jump tests. ResultsPatients with PT had significantly increased lateral patellar mobility compared to controls (12.21 ± 3.33 mm vs. 9.19 ± 1.92 mm, P = .017). PT patients showed significantly greater peak hip adduction with both drop vertical jump (2.7° ± 6.3° vs. -5.6° ± 4.2°; P = .003) and step down (17.0° ± 3.8° vs. 12.5° ± 4.4°, P = .024). PT patients demonstrated increased peak ankle external rotation with drop vertical jump (−21.1° ± 5.9° vs. −14.8° ± 5.5°, P = .023) and step down (−15.6° ± 5.5° vs. −9.0° ± 6.0°, P = .017). ConclusionsPatients with PT exhibit increased lateral patellar mobility, hip adduction, and ankle external rotation. The effects of increased patellar mobility deserve further study in the development, management, and prevention of PT.

Kinematic and kinetic differences between military patients with patellar tendinopathy and asymptomatic controls during single leg squats

BackgroundKnee valgus alignment has been associated with lower-limb musculoskeletal injury. This case-control study aims to: assess biomechanical differences between patients with patellar tendinopathy and healthy controls. Methods43 military participants (21 cases, 22 controls) were recorded using 3D-motion capture performing progressively demanding, small knee bend, single leg and single leg decline squats. Planned a priori analysis of peak: hip adduction, knee flexion, pelvic tilt, pelvic obliquity and trunk flexion was conducted using MANOVA. Kinematic and kinetic data were graphed with bootstrapped t-tests and 95% CI's normalised to the squat cycle. ANOVA and correlations in SPSS were used for exploratory analysis. FindingsOn their symptomatic side cases squatted to less depth (−6.62°, p < 0.05) than controls with exploratory curve analysis revealing a pattern of increased knee valgus collapse throughout the squatting movement (p < 0.05). Greater patella tendon force was generated by: the eccentric than concentric phase of squatting (+30–43%, ES 0.52–1.32, p < 0.01), declined (plantarflexed) compared to horizontal surface (+36–51%, ES 1.19–1.68, p < 0.01) and deeper knee flexion angles (F ≥ 658.3, p < 0.01) with no difference between groups (F ≤ 1.380, p > 0.05). Cases experienced more pain on testing on decline board (ES = 0.69, p < 0.01). For symptomatic limbs pain (rs = 0.458–0.641, p ≤ 0.05), but not VISA-P (Victoria Institute of Sport Assessment) (rs = 0.053–0.090, p > 0.05), correlated with extensor knee moment. InterpretationKnee valgus alignment is a plausible risk factor for patellar tendinopathy. Conclusions relating to causation are limited by the cross-sectional study design. Increasing squat depth, use of a declined surface and isolating the eccentric phase enable progression of loading prescription guided by pain.

Proposing a Patellar Tendinopathy Screening tool following a systematic review.

BackgroundPatellar tendinopathy (PT) is an overuse injury of the knee. The mechanism of injury is associated with repetitive stress on the patellar tendon of the knee as a result of explosive movement. Patellar tendinopathy is prevalent in all populations and is associated with intrinsic and extrinsic risk factors.ObjectivesPrimarily, the objective was to report on the intrinsic and extrinsic risk factors for PT, entailing a systematic review of the literature; the secondary objective was to use these risk factors to compile a proposed PT screening tool from the review and standard outcome measures.MethodA systematic review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Elimination criteria of the articles included duplicates, titles, abstracts and methodological quality. The evidence was collected, characterised with regard to the intrinsic and extrinsic risk factors and summarised descriptively.ResultsThe search yielded 157 feasible articles prior to commencement of article elimination. Six articles were included with a mean methodological quality score of 69%. Eight intrinsic and five extrinsic risk factors were identified. These identified risk factors are all relevant to the pathology and formed the basis for a proposed PT screening tool. The Victorian Institute of Sports Assessment for Patellar Tendinopathy Questionnaire, Visual Analog Scale and the Pain Provocation Test are also included in the proposed test.ConclusionIntrinsic and extrinsic risk factors for PT were identified, and consequently, the proposed PT screening tool was formulated for possible future testing in appropriate studies.Clinical implicationsPrevention of PT through intrinsic and extrinsic risk factor identification, and implementation in the clinical setup as a possible outcome measurement tool with which to verify functional improvement in PT rehabilitation.

Risk factors for patellar tendinopathy in volleyball and basketball players: A survey-based prospective cohort study.

Patellar tendinopathy (PT) is a common overuse injury of the patellar tendon in jumping athletes. In a recent large cross-sectional study from 2008 several factors were identified that may be associated with the etiology of PT. However, because of the study design no conclusions could be drawn about causal relations. The primary aim of the current study is to investigate whether the factors identified in the previous 2008 study can also be prospectively recognized as predictors of symptomatic PT in 2011. Nine hundred twenty-six Dutch elite and non-elite basketball and volleyball players from the previous study were invited again to complete an online survey about knee complaints and risk factors for PT in 2011. The logistic regression included 385 athletes of which 51 (13%) developed PT since 2008. Male gender [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.5] was found to be a risk factor for developing PT. No sports-related variables could be identified to increase the risk of developing PT, but some evidence was found for performing heavy physically demanding work, like being a nurse or a physical education teacher (OR 2.3, 95% CI 0.9-6.3). These findings indicate that, when considering preventive measures, it is important to take into account the total tendon load.

Obesity is a risk factor for patellar tendinopathy in middle-aged adults without clinical knee osteoarthritis

Obesity is a risk factor for patellar tendinopathy in middle-aged adults without clinical knee osteoarthritis

Low Range of Ankle Dorsiflexion Predisposes for Patellar Tendinopathy in Junior Elite Basketball Players

Background: Patellar tendinopathy (PT) is one of the most common reasons for sport-induced pain of the knee. Low ankle dorsiflexion range might predispose for PT because of load-bearing compensation in the patellar tendon. Purpose: The purpose of this 1-year prospective study was to analyze if a low ankle dorsiflexion range increases the risk of developing PT for basketball players. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: Ninety junior elite basketball players were examined for different characteristics and potential risk factors for PT, including ankle dorsiflexion range in the dominant and nondominant leg. Data were collected over a 1-year period and follow-up, including reexamination, was made at the end of the year. Results: Seventy-five players met the inclusion criteria. At the follow-up, 12 players (16.0%) had developed unilateral PT. These players were found to have had a significantly lower mean ankle dorsiflexion range at baseline than the healthy players, with a mean difference of −4.7° (P = .038) for the dominant limb and −5.1° (P = .024) for the nondominant limb. Complementary statistical analysis showed that players with dorsiflexion range less than 36.5° had a risk of 18.5% to 29.4% of developing PT within a year, as compared with 1.8% to 2.1% for players with dorsiflexion range greater than 36.5°. Limbs with a history of 2 or more ankle sprains had a slightly less mean ankle dorsiflexion range compared to those with 0 or 1 sprain (mean difference, −1.5° to −2.5°), although this was only statistically significant for nondominant legs. Conclusion: This study clearly shows that low ankle dorsiflexion range is a risk factor for developing PT in basketball players. In the studied material, an ankle dorsiflexion range of 36.5° was found to be the most appropriate cutoff point for prognostic screening. This might be useful information in identifying at-risk individuals in basketball teams and enabling preventive actions. A history of ankle sprains might contribute to reduced ankle dorsiflexion range.

Epidemiology of Patellar Tendinopathy in Elite Male Soccer Players

Background: Patellar tendinopathy is common among athletes in jumping sports and in sports with prolonged repetitive stress of the knee extensor apparatus. The epidemiology in soccer is not well described. Purpose: This study was undertaken to investigate and describe the epidemiology of patellar tendinopathy in elite male soccer players and evaluate potential risk factors. Study Design: Cohort study; Level of evidence, 2. Methods: Between 2001 and 2009, the authors followed 51 European elite soccer clubs (2229 players) from 3 different cohorts: the Swedish First League cohort (SWE) and Union of European Football Associations (UEFA) Champions League cohort (UCL), both playing on natural grass; and the Artifical Turf cohort (ART), playing on third-generation artificial turf. Individual player exposure in training and matches and time-loss injuries were recorded. Results: In total, 137 patellar tendinopathies were recorded, comprising 1.5% of all injuries and corresponding to an incidence of 0.12 injuries/1000 hours. Each season, 2.4% of players were affected, with most injuries (61%) resulting in absence up to 1 week or less. Twenty percent of tendinopathies were recurrent complaints. No significant difference in season prevalence (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.60-1.44; P = .74) or incidence (rate ratio [RR] 1.20; 95% CI, 0.82-1.75; P = .36) was observed between teams playing on artificial turf and natural grass, respectively. Multivariate logistic regression showed that a high total exposure hours (OR, 1.02 per 10-hour increase; 95% CI, 1.00-1.04; P = .033) was a significant risk factor for patellar tendinopathy, and increased body mass was borderline significant (OR, 1.15 per 5-kg increase; 95% CI, 1.00-1.33; P = .055). In addition, 2 acute partial tendon ruptures were recorded, but no total rupture. Conclusion: Although mainly mild in nature, patellar tendinopathy is a fairly common condition in elite soccer and the recurrence rate is high. Exposure to artificial turf did not increase the prevalence or incidence of injury. High total amount of exposure was identified as a risk factor for patellar tendinopathy.

Risk factors for patellar tendinopathy in volleyball players: a cross-sectional study

BackgroundPatellar tendinopathy (PT) has a multifactorial etiology, and many possible risk factors have been described in the literature. Findings are conflicting though, and most research is conducted on elite athletes.ObjectiveAim...

Is Patellar Mobility A Risk Factor For Patellar Tendinopathy?

Is Patellar Mobility A Risk Factor For Patellar Tendinopathy?

Risk factors for patellar tendinopathy in competitive volleyball players

BackgroundPatellar tendinopathy (PT) is an important problem in a volleyball population. However, in order to optimize rehabilitation and prevention strategies, not all intrinsic risk factors are known. This study is...

Risk factors for patellar tendinopathy in basketball and volleyball players: a cross‐sectional study

Patellar tendinopathy (PT) has a multifactorial etiology, and many possible risk factors have been described in the literature. The findings are conflicting, though, and most research has been conducted on elite athletes. The aim of the current study is to determine the risk factors for PT in a large representative sample of basketball and volleyball players. Separate risk factors for men and women, basketball and volleyball players, and athletes with unilateral and bilateral PT were identified. All basketball and volleyball players between ages 18 and 35 from the Dutch Basketball Association and the Dutch Volleyball Association were invited to complete an online questionnaire on knee complaints and risk factors for PT. The logistic regression analyses included 2224 subjects. The risk factors for PT were age, playing at the national level, being male and playing volleyball (compared with playing basketball). The risk factors for men and women were comparable. Among volleyball players, outside hitters and middle blockers/hitters had an increased risk compared with setters. For basketball players, no risk factors could be identified. No differences in the risk factors were found between athletes with unilateral and bilateral PT. These findings should be taken into account for prevention and rehabilitation purposes.

Risk factors for patellar tendinopathy in basketball and volleyball players: a cross-sectional survey

BackgroundPatellar tendinopathy has a multifactorial aetiology, and many potential risk factors have been described in the literature. Findings are conflicting though, and most research is conducted on elite athletes.ObjectiveAim of...

Risk factors for patellar tendinopathy: a review of the literature

BackgroundPatellar tendinopathy (PT) is an injury which has a high prevalence in sports, especially in those involving jumping. Because successful treatment of PT remains challenging, prevention is of utmost importance....

The impact of physically demanding work of basketball and volleyball players on the risk for patellar tendinopathy and on work limitations

Patellar tendinopathy is a common injury in jumping athletes. Little is known about work-related etiological factors for patellar tendinopathy and related work limitations. The aim of this study was to identify work-related etiological factors for patellar tendinopathy and to determine the relation between patellar tendinopathy and work limitations. Basketball and volleyball players between 18 and 35 years were invited to complete an online-questionnaire concerning knee complaints, etiological risk factors for patellar tendinopathy and related work limitations. A total of 1505 subjects were included in the analysis. Risk factors for patellar tendinopathy were gender and heavy physically demanding work. The odds for having patellar tendinopathy were significantly higher for heavy physically demanding occupations compared to mentally demanding occupations. 30% of subjects with patellar tendinopathy with a physically demanding job reported to be impaired in their work and 17% reported to be less productive. Basketball and volleyball players with heavy physically demanding work seem to have an increased risk for developing patellar tendinopathy. This finding has important clinical relevance in the treatment of this injury. Working activities should be adjusted in order to reduce the total load on the patellar tendon and help prevention and recovery.