Patellar tendon: From tendinopathy to rupture

Association Between Patellar Tendon Abnormality and Land-Jump Biomechanics in Male Collegiate Basketball Players During the Preseason

Background

Patellar tendinopathy is a degenerative condition that predominantly affects jumping athletes. Symptoms may be subtle or nonexistent at preseason, but structural abnormalities may be present. Assessing patellar tendon abnormality (PTA) through magnetic resonance imaging (MRI) and ultrasound (US) and classifying symptoms using the Victorian Institute for Sport Assessment-Patellar tendon (VISA-P) may provide useful insights if combined with biomechanics measurements.

Purpose

To (1) assess whether land-jump biomechanical patterns are associated with clinically pertinent PTA as seen on imaging and through VISA-P scores and (2) model the contributing risk and accuracy of biomechanics to classify PTA and symptomatic observations.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 26 National Collegiate Athletic Association Division I and II male basketball players (n = 52 limbs) were recruited during the preseason. We collected VISA-P scores, bilateral PTA through US and MRI morphology measurements, and bilateral 3-dimensional lower extremity kinematics and kinetics measurements from a land-jump test from an 18-inch-high (45.7-cm-high) box. Statistically, each limb was treated independently. The association of biomechanics with PTA and symptoms (VISA-P score <80) was tested with multivariate models and post hoc tests. Logistic regression modeled relative risk and accuracy of biomechanical variables to classify PTA and symptomatic limbs.

Results

There were 19 to 24 limbs with PTA depending on US and MRI measurements. Differences in hip and knee kinematic strategies and ground-reaction loads were associated with PTA and symptomatic limbs. Peak landing vertical ground-reaction force was significantly decreased (169 ± 26 vs 195 ± 29 %body weight; P = .001), and maximum hip flexion velocity was significantly increased (416 ± 74 vs 343 ± 94 deg/s; P = .005) in limbs with versus without PTA on imaging. Knee flexion at the initial contact was decreased in symptomatic versus healthy limbs (17°± 5° vs 21°± 5°, respectively; P = .045). Regression models classified PTA limbs and symptomatic limbs with 71.2% to 86.5% accuracy. Hip and knee maximum flexion velocity and vertical ground-reaction force variables were most common across models observing clinically pertinent PTA.

Conclusion

Our findings suggested that functional kinematic and kinetic biomechanical strategies at the hip and knee were associated with PTA, identified on imaging, and symptomatic limbs.

Bibliometric Analysis of the Top 50 Most Influential Studies on Patellar Tendon Injury

Background

There is a wide range of literature on patellar tendon injury, making it increasingly difficult to stay informed on the most influential studies in this field. It is essential to be familiar with the foundational articles of patellar tendon injury research to understand the current state of the literature and deliver high quality care.

Purpose

To objectively identify the 50 most influential articles relating to patellar tendon injury and conduct a bibliometric analysis to identify key features of these articles.

Study Design

Cross-sectional study.

Methods

The Clarivate Analytics Web of Knowledge database was utilized to gather metrics on the 50 most cited articles on patellar tendon injury on June 27, 2022. The information extracted from each article included publication year, number of citations, author information, article type, level of evidence, country of origin, journal name, study focus, and industry influence.

Results

The top 50 studies were cited a total of 8543 times and published between 1977 and 2015. The majority of articles were published after 2003, and the majority of citations were accrued after 2011. The most prevalent article types were cohort studies (n = 23), and the majority of studies were of evidence level 2 (n = 14) or 4 (n = 13). Australia and the United States (US) each published the most studies (n = 11). Only 4 (8%) studies focused on patellar tendon rupture, and 12 (24%) of the top 50 studies were associated with industry.

Conclusion

The majority of the top 50 most influential articles in patellar tendon injury were published and accumulated citations in the past 10 to 20 years. Non-US countries, institutions, and journals published many of the top 50 studies, reflecting a global interest and commitment to research in this field. Patellar tendon rupture and surgical repair represents a minority of research in the top 50 studies and could be a point of growth in the future.

Management of Neglected Patellar Tendon Rupture via the Ilizarov Apparatus and Patellar Transport Following Multistage Reconstruction using Contralateral Patella Tendon Bone Autograft: A Case Study

Muscle elongation by Ilizarov apparatus is one of the most remarkable surgeries performed to date. Chronic patella tendon injury is an uncommon condition, and due to its rarity, it is difficult to operate and restore the quality of life and function of the patient. Here we demonstrated a 40-year-old Saudi person who underwent a three-stage operative procedure on him: in the first stage we entailed debridement and removal of the implant; in the second stage, we performed this innovative Ilizarov muscle elongation of the quadriceps, and in the third stage, we reconstructed the right patellar tendon using a contralateral patella tendon bone autograft fixed by 3.5 screws proximal to the patella and distal to the tibial tuberosity and augmented by cerclage wires. After 3 months of intensive physical therapy, the patient regained his knee's range of motion and muscle strength and was able to return to his security job.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00608-5.

The Burden and Risk Factors of Patellar and Achilles Tendinopathy in Youth Basketball: A Cohort Study

This study aimed at evaluating the burden and risk factors of patellar and Achilles tendinopathy among youth basketball players. Patellar and Achilles tendinopathy were prospectively monitored in 515 eligible male and female youth basketball players (11–18 years) through a competitive season. Overall, the season prevalence of patellar tendinopathy was 19.0% (95% CI: 15.7–22.7%), 23.2% (95% CI: 18.6–28.2%) in males and 12.5% (95% CI: 8.3–17.9%) in females. The season prevalence of Achilles tendinopathy was 4.3% (95% CI: 2.7–6.4%), 4.1% (95% CI: 2.2–7.0%) in males and 4.5% (95% CI: 2.1–8.4%) in females. Median proportion of symptoms duration was 83% of average total weeks of basketball exposure for patellar tendinopathy and 75% for Achilles tendinopathy. Median time to patellar tendinopathy onset was 8 weeks for male players and 6 weeks for female players. Higher odds of patellar tendinopathy risk were seen in males (OR: 2.23, 95% CI: 1.10–4.69) and players with previous anterior knee pain had significantly elevated odds (OR: 8.5, 95% CI: 4.58–16.89). The burden and risk of patellar tendinopathy is high among competitive youth basketball players. Risk factors include sex and previous anterior knee pain. These findings provide directions for practice and future research.

Impact of Patellar Tendinopathy on Isokinetic Knee Strength and Jumps in Professional Basketball Players

Patellar tendinopathy is characterized by tendon pain which may reduce the level of performance. This study's main aim was to compare isokinetic knee strength and jump performances at the start of the sport season between players with patellar tendinopathy and those without. Secondary aims were to assess the relationship between knee strength and jump function. Sixty-two professional basketball players were enrolled (mean age: 25.0 ± 4.0). All players performed knee isokinetic measurements, single leg countermovement jumps, and one leg hop tests. Correlations between knee strength and jump performances were examined. Twenty-four players declared a patellar tendinopathy and were compared to the 38 players without tendinopathy. The isokinetic quadriceps strength was lower in cases of patellar tendinopathy, and a camel's back curve was observed in 58% of the cases of patellar tendinopathy. However, jump performances were preserved. No link was found between quadriceps and hamstring limb symmetry indexes at 60 and 180°/s with jumps. This preseason screening enabled us to identify the absence of consequences of patellar tendinopathy in professional basketball players. Jump performances were not altered, possibly due to compensatory strategies.

Bilateral Atraumatic Patellar Ligament Rupture-Case Report

Bilateral atraumatic rupture of the patellar ligament is a rare lesion, usually associated with systemic diseases and drugs such as steroids and fluoroquinolones. This report presents a case of bilateral atraumatic rupture of the patellar ligament in a 43-year-old male with obesity, type 2 diabetes mellitus, and who was being treated with a systemic corticosteroid for autoimmune disease (Wegener granulomatosis). These factors caused chronic degenerative and inflammatory changes in the ligaments, confirmed by the histological examination. Due to tissue quality, a primary ligament repair associated to an augmentation with semitendinosus tendon was performed. After 1 year, the patient presented satisfactory evolution, regaining the full range of motion and returning to his usual activities without sequelae.

Epigenetic Status of The Human MMP11 Gene Promoter is Altered in Patellar Tendinopathy

Patellar tendinopathy (PT) is a debilitating condition that often affects those who are physically active. Gene variation is known to contribute to human tendinopathy but the role of DNA methylation, as an epigenetic factor, has only recently been discovered. Using a case-control approach, we sought to determine whether differences existed between the methylation status of the MMP11 gene promoter in patellar tendinopathy compared to healthy tendon. We used PCR and pyrosequencing to interrogate the methylation profiles of 4 CpG sites (areas of the genome rich in C/G nucleotides) upstream of the MMP11 gene in DNA from males with PT (n = 10) and those with healthy tendon (n = 10). We also conducted a correlation analysis to establish whether age influenced methylation in the PT patients and controls. We found a significant (p = 0.045) difference in the methylation status of a single CpG site 65 base pairs (bp) upstream of the MMP11 promoter between the PT group and controls. There were no other differences in the extent of MMP11 promoter methylation between the two groups. Interestingly, we also found that in controls the degree of methylation at a second CpG site, 55 bp upstream of the first exon, tentatively correlated (r = 0.77, p = 0.009) with age. However, the correlation did not reach significance when a potential outlier was removed. This is the first study to show an epigenetic alteration to a member of the MMP gene family in human patellar tendinopathy. The data add to our understanding of how epigenetics should be considered when developing appropriate risk models.

Jumper's knee mechanical consequences in professional basketball players: the "Camel's Back curve"

PURPOSE

Jumper's knee is characterized by an anterior knee pain during tendon palpation and can be classified in overuse pathologies, secondary to repetitive jumps. The prevalence is high in professional basketball players. It is responsible for an alteration of the motor control inducing a strength deficit of the quadriceps. We aimed to describe an isokinetic curve anomaly, a double-humped curve called "Camel's Back curve", consequence of a jumper's knee history.

METHODS

170 Professional basketball players were enrolled (24.8 ± 4.6 years; 91.8 ± 12.0 kg, 194 ± 9.0 cm). All players performed isokinetic tests of the knee extensors on a concentric mode at the angular speed of 60°/s and 180°/s.

RESULTS

43 players had a jumper's knee history and 35 (81%) had a "Camel's Back curve" at 60°/s. The sensitivity and the specificity of this curve were 81.3% and 100%, respectively. The minimum torque of strength was decreased from 12 to 18% compared to the 2 maximal peaks. Yet, the strength measured every 5° of ROM was significantly different between the players with "Camel's Back curve" and those with normal curve.

CONCLUSIONS

"Camel's Back curve" had never been described in that context. It may be secondary to a protective inhibitory mechanism which could alter jumping. The presence of a "Camel's Back curve" would enable clinicians to adapt physical preparation, knee rehabilitation, and trainings to improve players performances.

Proposing a Patellar Tendinopathy Screening tool following a systematic review

BACKGROUND

Patellar 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.

OBJECTIVES

Primarily, 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.

METHOD

A 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.

RESULTS

The 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.

CONCLUSION

Intrinsic 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 IMPLICATIONS

Prevention 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.

Comparative diagnostic imaging of a partial patellar ligament tear in a dog

Traumatic lesions of the patellar ligament (PL) are rare in dogs. The resulting injury can be a complete or partial laceration, depending on the quantity of torn collagen fibres. Information obtained from imaging evaluation is of great value to the clinical approach towards PL injuries, because subsequent treatment options are affected by the distinction between complete or partial tears. Imaging diagnosis of PL damage in veterinary practice commonly relies on radiographic examination through the recognition of indirect signs, such as “patella alta”, bone fragments at the level of the patellar or tibial insertion, and soft tissue opacity at the cranial aspect of the joint. Although ultrasound (US) and magnetic resonance imaging (MRI) have been described as useful diagnostic tools for the assessment of PL tears in human patients, specific comparative data regarding the evaluation of PL rupture in dogs using different imaging modalities is lacking in the veterinary literature. This paper describes the radiographic, ultrasonographic, CT and MRI imaging findings of a partial PL tear in a dog and discusses the utility of these techniques in diagnosing this condition. CT provided more detailed information than X-ray examination in the assessment of the osteoligamentous junction, the exclusion of microfracture and distal PL avulsion, but did not add information regarding PL integrity. MRI and US provided the most useful information regarding intra-ligamentous damage and as such their combined use may be considered for the assessment of PL injuries after clinical examination and survey radiographs.

Pharmacologic Therapies in Musculoskeletal Conditions

Musculoskeletal conditions are common, and there are many options for pharmacologic therapy. Unfortunately, there is not strong evidence for the use of many of these medications. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are generally first-line medications for most musculoskeletal pain, but there is more evidence these medications are not as safe as once thought. Other analgesic and antispasmodic medications can be effective for acute pain but generally are not as effective for chronic pain. Antidepressants and anticonvulsants can be more effective for chronic or neuropathic pain. Topical formulations of NSAIDs can be effective for pain with fewer side effects.