A cross sectional study of 100 athletes with jumper's knee managed conservatively and surgically. The Victorian Institute of Sport Tendon Study Group

Modifiable risk factors for patellar tendinopathy in athletes: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis identifying (1) potential modifiable risk factors and (2) associated modifiable factors for patellar tendinopathy in athletes.

DESIGN

A systematic review and meta-analysis was conducted. Risk of bias was assessed using the Newcastle-Ottawa Scale and grouped based on study design. Meta-analytic statistics were performed for items reported by five or more studies. A strength of evidence rating is provided for items not appropriate for meta-analysis.

DATA SOURCES

PubMed, Web of Science, Scopus and Cinahl were searched on 14 November 2017.

ELIGIBILITY CRITERIA

Quantitative, original research reporting potential modifiable risk factors or associated factors, comparing athletes with patellar tendinopathy with a group without the injury.

RESULTS

862 records were screened and 31 articles were included (6 prospective, 25 cross-sectional). There was a lack of strong evidence for any potential modifiable risk factor or associated factors. There was limited or conflicting evidence that decreased ankle dorsiflexion range of motion, decreased posterior thigh and quadriceps flexibility, greater volume of jump training, more volleyball sets played per week, greater countermovement jump (CMJ) height and greater activity volume are potential modifiable risk factors. Meta-analysis supported greater activity volume (Cohen's d=0.22, 95% CI 0.06 to 0.39, p=0.008), higher body weight (0.36, 0.17 to 0.55, p<0.001) and greater CMJ height (0.31, 0.07 to 0.56, p=0.01) as associated modifiable factors.

CONCLUSIONS

There is a lack of strong evidence for any potential modifiable risk factors or associated factors. Factors with lower levels of support may be of interest in designing prevention programmes but require further research in high-quality, prospective studies.

Ultrasound examination and patellar tendinopathy scores in asymptomatic college jumpers

OBJECTIVE

To investigate the prevalence of hypoechoic areas by US and its' association with VISA-P scores among asymptomatic jumpers while highlighting sex comparisons.

DESIGN

Cross-sectional study.

SETTING

Pre-participation exam at a National Collegiate Athletic Association (NCAA) division I college.

PARTICIPANTS

Thirty-one college athletes who engage in jumping sports.

MAIN OUTCOME MEASURES

Hypoechoic images of patellar tendon captured by ultrasound examination were compared to a self-reported knee functional survey, the Victorian Institute of Sport Assessment for patellar tendinopathy (VISA-P) scale (0-100).

RESULTS

With a total of 31 athletes (13 males and 18 females), prevalence rate of the hypoechoic areas of patellar tendon was 19.4% (6/31) in the right knee and 29.0% (9/31) in the left knee. There was no proportional difference in a comparison of prevalence rate of hypoechoic area [(+) or (-)] by sex in either right or left knee. The VISA-P scores were significantly lower in US (+) than US (-) in the right knee (p = 0.003, Cohen's d = 1.675), but not the left knee (p = 0.250, Cohen's d = 0.512). The receiver operating characteristics curve analysis indicated the most sensitive and specific VISA-P values based on status [(+) or (-)] of hypoechoic area was 89.5 with 86.4% and 77.7% of sensitivity and specificity.

CONCLUSION

In short, hypoechoic areas were detected by US examination among self-reported asymptomatic jumpers. There was an association between hypoechoic areas and VISA-P scores in the right knee, but not in left knee. VISA-P scores may be used as a screening tool for the presence of hypoechoic areas.

Up to a quarter of patients with certain chronic recalcitrant tendinopathies may have central sensitisation: a prospective cohort of more than 300 patients

Introduction

To identify the possible prevalence of 'central sensitisation', in patients with chronic recalcitrant lower limb tendinopathy conditions, with the Central Sensitisation Inventory (CSI) questionnaire.

Methods

Patients with chronic lower limb tendinopathy conditions treated within a single hospital outpatient clinic specialising in tendinopathy were identified from clinical records. As part of routine care, self-reported numerical markers of pain, global function (using the EuroQol-5D (EQ-5D) questionnaire) and the CSI score to investigate the possibility of central sensitisation were completed.

Results

A total of 312 suitable patients with chronic lower limb tendinopathy and similar conditions were identified, who had completed a CSI questionnaire. Of these, 108 presented with greater trochanteric pain syndrome, 12 with patella tendinopathy, 33 with non-insertional Achilles tendinopathy, 48 with insertional Achilles tendinopathy and 110 with plantar fasciitis. A total of 66% of the patients were female, the median age was 54.9 years and the median duration of symptoms was 24 months. There was a median CSI score of 25%, with statistically significant differences noted between the different conditions studied. Overall, 20% of patients scored above a threshold of 40% on CSI questionnaire, indicating that central sensitisation was possible. Greater trochanteric pain syndrome and plantar fasciitis had the highest proportions in the conditions studied. Weak correlations were found between CSI and other pain scores studied.

Conclusion

The CSI questionnaire may identify up to a quarter of patients with some chronic lower limb tendinopathy and associated conditions as being more likely to have central sensitisation, and these proportions differed between conditions. The clinical significance of this is unclear, but worth further study to see if/how this may relate to treatment outcomes. These are results from a single hospital clinic dealing with patients with chronic tendinopathy, and comparison with a control group is currently lacking. However, on the information presented here, the concept of central sensitisation should be considered in patients being treated for chronic tendinopathy.

Effects of a strength protocol combined with electrical stimulation on patellar tendinopathy: 42 months retrospective follow-up on 6 high-level jumping athletes

STUDY DESIGN

A retrospective study.

INTRODUCTION

Patellar tendinopathy (PT) or jumper's knee (JK) in elite athletes is a challenging condition for sports medicine professionals. This study analyzes the development of a protocol using eccentric, isometric, concentric exercises, and electrostimulation to treat elite athletes suffering from JK. The semiannual strength protocol was completed during a total of 36 months by six high-level jumping athletes with chronic painful JK. Pain during patellar tendon loading activity was evaluated on a visual analogue pain scale (VAS). Upon protocol completion, promising clinical results were evidenced by significant pain reduction during tendon loading activity.

MATERIAL AND METHODS

Six high level jumping athletes with chronic painful JK completed a semiannual strength program using eccentric, isometric, concentric and electrical stimulation exercises. The protocol was done 12 weeks in the winter pre-season and 10 weeks in the summer pre-season, for altogether 36 months, with an interruption of the protocol at 24 months for 6 months. Pain during patellar tendon loading activity was evaluated on a visual analogue pain scale (VAS), before the first session and then every 6 months, coinciding with the competitive phase, the time of maximum pain.

RESULTS

There was a significant (p < 0.01) decrease in the VAS from start to the 18, 24 and 48 months follow-ups.

CONCLUSIONS

In a small group of high level jumping athletes with chronic painful JK, a strength protocol combined with electrical stimulation showed promising clinical results with significant pain reduction during tendon loading activity.

A preliminary study to investigate the prevalence of pain in international event riders during competition, in the United Kingdom

The aim of the study was to investigate the prevalence of riders at the international levels in eventing, competing with pain, the location of their pain, factors affecting their pain and whether they perceived this pain to have an effect on their performance. 331 questionnaires were completed by international event riders (FEI CCI*, CCI**, CIC***) at the Hartpury International Horse Trials, UK, to establish the prevalence of riders competing with pain. 96% of international event riders competed while experiencing pain, 76% of riders stated that this pain was in the neck, upper back or shoulders. All female riders reported pain, giving a significant correlation between gender and pain (X=-0.479, P=0.006). 55% of riders felt their pain affected their riding performance, giving an odds ratio of 1.14, compared to those riders who felt their pain did not effect their performance. Pain was perceived to influence performance by affecting fatigue, their concentration, and anxiety levels. 96% of riders reporting pain used medication to alleviate their symptoms. This high incidence of international event riders who compete with pain, particularly back pain, could be problematic given the longevity of a rider’s career, which can span over four decades and could potentially increase the risk of a serious or fatal fall in the cross-country phase. This research reports rider’s perceptions and self-reported pain and management options, which may affect the data. Further research is needed to establish the causes of back pain and appropriate management strategies.

Tendon neuroplastic training for lateral elbow tendinopathy: 2 case reports

OBJECTIVE

To report 2 cases of lateral elbow tendinopathy treated with a novel adaptation of tendon neuroplastic training (TNT).

CLINICAL FEATURES

Patient 1: A 61-year-old male machine operator presented with one year of bilateral lateral elbow pain related to his occupation of using torque wrenches.Patient 2: A 37-year-old male electrician presented with two months of recurrent left lateral elbow pain related to repetitive motions of gripping and pulling at work.

INTERVENTION AND OUTCOME

Both patients underwent 8 weeks of a novel rehabilitation program, including TNT, which involved pacing their resistance exercises to a metronome. Both patients experienced clinically meaningful improvements in pain and functional outcome scores that were sustained at the 3-month follow-up.

SUMMARY

Recent evidence suggests that the central nervous system may play a role in chronic tendinopathies. It is possible that TNT may address the central nervous system component of chronic/recurrent tendinopathy that is not addressed by traditional passive therapies. However, further research is needed.

Patellar tendinopathy with intratendinous alteration on MRI may be related to patellofemoral dysplasia

Patellar tendinopathy (PT) is a frequent overuse injury of the extensor knee apparatus, whereas as up to 30% of the athletes might suffer from persisting symptoms during their entire career. In the present case-control study, 47 patients (30.8 ± 11.4 years) with PT with intratendinous alteration (PTita) of a minimum of ≥25% of the axial surface on MRI and minimum Blazina score of II (pain during without limiting sports activity) were included; MR images were analyzed for trochlear geometry, patellar height/tilt, and tibial tubercle-trochlear groove distance (TT-TG). The control group (CG) comprised 87 age- and gender-matched patients without history of anterior knee pain or lateral patellar instability. It was hypothesized that patients with PT might be related to patellofemoral dysplasia. It was found that the patella was significantly higher in patients with PT compared to the CG (patellotrochlear index [PT-I]: 0.33 vs 0.37, P = .014; Insall-Salvati index [InSa]: 1.18 vs 1.07, P = .004). PT-I was above the cut-off value in 10.6% of PT knees (CG 5.7%, P = .27), and InSa in 42.6% (CG 21.8%, P = .012). TT-TG was significantly higher in patients with PT compared to CG (12.0 mm vs 9.9 mm, P = .002); however, TT-TG was only pathologic (>20 mm) in one patient. The trochlear facet ratio was above the cut-off value in 55.3% of PT patients and 23% of CG (P < .001), and was significantly greater in patients with PT (0.39 ± 0.09) than CG (0.48 ± 0.1, P < .001). Knees with PT have significantly more morphological characteristics of patellofemoral instability, which needs to be considered especially in recurrent or treatment-refractive cases.

Development of overuse tendinopathy: A new descriptive model for the initiation of tendon damage during cyclic loading

Tendinopathic tissue has long been characterized by changes to collagen microstructure. However, initial tendon damage from excessive mechanical loading-a hallmark of tendinopathy development-could occur at the nanoscale level of collagen fibrils. Indeed, it is on this scale that tenocytes interact directly with tendon matrix, and excessive collagen fibril damage not visible at the microscale could trigger a degenerative cascade. In this study, we explored whether initiation of tendon damage during cyclic loading occurs via a longitudinal compression-induced buckling mechanism of collagen fibrils leading to nanoscale kinkband development. Two groups of tendons were cyclically loaded to equivalent peak stresses. In each loading cycle, tendons in one group were unloaded to the zero displacement mark, while those in the other group were unloaded to a nominal level of tension, minimizing the potential for fibril buckling. Tendons that were unloaded to the zero displacement mark ruptured significantly sooner during cyclic loading (1,446 ± 737 vs. 4,069 ± 1,129 cycles), indicating that significant fatigue damage is accrued in the low stress, toe region of the load-deformation response. Ultrastructural analysis using scanning electron microscopy of tendons stopped after 1,000 cycles showed that maintaining a nominal tension slowed the accumulation of kinkbands, supporting a longitudinal compression-induced buckling mechanism as the basis for kinkband development. Based on our results, we present a new descriptive model for the initiation of tendon damage during cyclic loading. The so-called Compression of Unrecovered Elongation or CUE Model may provide useful insight into the development of tendinopathy. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:467-476, 2018.

Spanish Consensus Statement: Clinical Management and Treatment of Tendinopathies in Sport

On October 15, 2016, experts met at Clínica CEMTRO in Madrid, Spain, under the patronage of the Spanish Society for Sports Traumatology (SETRADE), the Spanish Society of Sports Medicine (SEMED), the Spanish Association of Medical Services for Football Clubs (AEMEF), the Spanish Association of Medical Services for Basketball Clubs (AEMB), F.C. Barcelona, and Clínica CEMTRO. The purpose was to consider the most appropriate clinical management and treatment of tendinopathies in sports, based on proven scientific data described in the medical literature as well as on each expert’s experience. Prior to the meeting, each expert received a questionnaire regarding clinical management and treatment of tendinopathies in sports. The present consensus document summarizes the answers to the questionnaire and the resulting discussion and consensus regarding current concepts on tendinopathies in sports.

Effects of Time to Start Training After Acute Patellar Tendon Enthesis Injuries on Healing of the Injury in a Rabbit Model

BACKGROUND

A patellar tendon injury is a common injury in sports. The optimal time to start training after an acute, proximal patellar enthesis injury is still unclear.

HYPOTHESIS

The time to start training after an acute, proximal patellar enthesis injury significantly affects healing of the patellar tendon 4 weeks after the injury.

STUDY DESIGN

Controlled laboratory study.

METHODS

The left hindlimbs of 35 mature female rabbits were randomly assigned to 5 injury groups including a 4-week natural healing group (NH4W) and 4 training groups that started low-intensity training at 24 hours (POST24), 48 hours (POST48), 72 hours (POST72), and 96 hours (POST96) after an acute patellar tendon injury, with 7 limbs in each group. The right hindlimbs of the NH4W group were used as a control group (CON). An acute, proximal patellar enthesis injury was created in all injury groups. The training groups underwent low-intensity quadriceps training for 2 hours per day and 3 days per week for 4 weeks. Histological and radiographic data were collected and analyzed.

RESULTS

The cell densities of the training groups were significantly lower than those of the NH4W and CON groups ( P = .01). The fibrocartilage zone was significantly thicker in the POST24, POST48, and POST72 groups compared with the CON and NH4W groups and was the thickest in the POST24 group ( P = .01). The bone surface to bone volume ratio was significantly higher in all the injury groups compared with the CON group and in the POST24 group compared with the other groups ( P = .01). Trabecular thickness was significantly lower in all the injury groups compared with the CON group and in the POST24 group compared with the other groups ( P = .01).

CONCLUSION

Resting without training in the first 96 hours after an acute patellar tendon enthesis injury resulted in the best recovery of cell density in the tendon enthesis 4 weeks after the injury. Starting training 96 hours after the injury resulted in the best recovery of fibrocartilage zone thickness. Starting training 48 to 96 hours after the injury resulted in the best healing of the bone component of the attachment site 4 weeks after the injury. The optimal time to start training may be longer than 96 hours after an acute patellar tendon enthesis injury for the best overall healing of the tendon enthesis 4 weeks after the injury.

CLINICAL RELEVANCE

A rest of a minimal 72 hours may be needed for the best healing of a patellar tendon enthesis after an acute injury. Future studies are needed to determine the optimal time to start training after an acute patellar tendon injury.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part I: biology, biomechanics, anatomy and an exercise-based approach

Chronic tendinopathies represent a major problem in the clinical practice of sports orthopaedic surgeons, sports doctors and other health professionals involved in the treatment of athletes and patients that perform repetitive actions. The lack of consensus relative to the diagnostic tools and treatment modalities represents a management dilemma for these professionals. With this review, the purpose of the ESSKA Basic Science Committee is to establish guidelines for understanding, diagnosing and treating this complex pathology.

Open Patellar Tendon Tenotomy, Debridement, and Repair Technique Augmented With Platelet-Rich Plasma for Recalcitrant Patellar Tendinopathy

Patellar tendinopathy is a disabling condition that frequently affects the athletic population, especially athletes undergoing repetitive impact forces as a result of jumping and landing activities. Most cases are initially treated conservatively, but if symptoms persist, surgical treatment is warranted. Options for surgical treatment include both arthroscopic and open techniques. The purpose of this Technical Note is to detail our open patellar tendon tenotomy, debridement, and repair technique augmented with platelet-rich plasma.

Effectiveness of Shockwave Treatment Combined With Eccentric Training for Patellar Tendinopathy: A Double-Blinded Randomized Study

OBJECTIVE

To evaluate the effectiveness of a combined treatment of focused shockwave therapy (ESWT) and eccentric training compared with sham-shockwave therapy (placebo) and eccentric training in participants with patellar tendinopathy (PT) after 24 weeks.

DESIGN

Randomized controlled trial.

SETTING

Sports medicine departments of a university hospital and a general hospital in the Netherlands.

PARTICIPANTS

Fifty-two physically active male and female participants with a clinical diagnosis of PT (mean age: 28.6 years; range, 18-45) were randomly allocated to the ESWT (n = 22) or sham shockwave (n = 30).

INTERVENTIONS

Extracorporeal shockwave therapy and sham shockwave were applied in 3 sessions at 1-week intervals with a piezoelectric device. All participants were instructed to perform eccentric exercises (3 sets of 15 repetitions twice a day) for 3 months on a decline board at home.

MAIN OUTCOME MEASURES

The Victorian Institute of Sport Assessment-Patella (VISA-P) scores (primary), pain scores during functional knee loading tests, and Likert score (secondary) were registered at baseline and at 6, 12, and 24 weeks after the start with the ESWT or sham-shockwave treatment.

RESULTS

No significant differences for the primary and secondary outcome measures were found between the groups. In the ESWT/eccentric group, the VISA-P increased from 54.5 ± 15.4 to 70.9 ± 17.8, whereas the VISA-P in the sham-shockwave/eccentric group increased from 58.9 ± 14.6 to 78.2 ± 15.8 (between-group change in VISA-P at 24 weeks -4.8; 95% confidence interval, -12.7 to 3.0, P = 0.150).

CONCLUSIONS

This study showed no additional effect of 3 sessions ESWT in participants with PT treated with eccentric exercises. The results should be interpreted with caution because of small sample size and considerable loss to follow-up, particularly in the ESWT group.

Patellar tendon straps decrease pre-landing quadriceps activation in males with patellar tendinopathy

OBJECTIVE

To determine if patellar tendon straps altered quadriceps' muscle activity during a drop-jump landing in males with and without patellar tendinopathy.

DESIGN

Case-control.

SETTINGS

Biomechanics Research Laboratory.

PARTICIPANTS

Twenty recreationally-active males participated: ten (age = 21.3 ± 2.4 years, height = 182.8 ± 5.3 cm, mass = 81.7 ± 8.6 kg) with patellar tendinopathy; ten (age = 22.0 ± 1.6 years, height = 185.7 ± 4.5 cm, mass = 82.2 ± 9.8 kg) were healthy with no history of tendinopathy.

MAIN OUTCOME MEASURES

Electromyography (EMG) data for the vastus medialis (VM), rectus femoris (RF), and vastus lateralis (VL) muscles were collected. Five 2-legged 40 cm drop-jumps were performed wearing a patellar tendon strap and 5 with no-strap in a counterbalanced order. Root-mean square EMG (REMG) values of the VM, RF, and VL were averaged for a pre-landing and post-landing interval. Multiple mixed-model two-way ANOVAs were performed to determine the effect of tendinopathy and strapping condition on REMG values for each muscle.

RESULTS

For the pre-landing interval, all participants displayed lesser VL EMG activation (0.44 ± 0.19%, 0.53 ± 0.27%, respectively; p = 0.007, d = 0.39) in the no-strap compared with the strap condition.

CONCLUSIONS

When wearing a strap, all participants demonstrated lower VL activation prior to landing which may be helpful in reducing tensile stress at the tendon. These effects may be clinically important in modulating pain in those with patellar tendinopathy.

Refractory patella tendinopathy with failed conservative treatment-shock wave or arthroscopy?

AIM

To identify whether the location of refractory patella tendinopathy (PT) has an effect on treatment modality (radial extracorporeal shock wave therapy (rESWT) or arthroscopic debridement).

METHODS

Between 2012 and 2014, 40 patients with PT underwent a magnetic resonance imaging (MRI) scan. This confirmed the diagnosis as either involving the tendon itself (group A, 20) or with retropatella fat pad extension (group B, 20). All patients underwent rESWT. If there was no improvement patients proceeded with surgery in the form of arthroscopic debridement (by senior authors CW and AG). Outcomes were assessed before and after treatment using the Victorian Institute of Sports Assessment-Patella (VISA-P) score.

RESULTS

There were 18 males and 2 females in group A and 15 males and 5 females in group B. The mean age was 41.4 years in group A (23-59) and 34.7 in group B (19-52). Seventeen of 20 in group A reported good or excellent outcomes and did not require surgical intervention (remaining three improved after second course of ESWT). All patients in group B failed to improve with rESWT, resulting in arthroscopic debridement and reported good or excellent outcomes. After 6 months, group A mean VISA-P score increased from 50.2 to 65.0 ( p = 0.01) and group B from 39.6 to 78.4 ( p = <0.001).

CONCLUSION

An MRI should be performed to determine the precise location of tendinosis in patients with refractory PT who fail standard conservative management. If the MRI scan shows intratendon changes only, ESWT should be performed and those with extension into the fat pad should proceed to arthroscopic debridement without rESWT.

At What Age Do Children and Adolescents Develop Lower Limb Tendon Pathology or Tendinopathy? A Systematic Review and Meta-analysis

BACKGROUND

Tendon pathology and tendinopathy have been reported in children and adolescents; however, the age at onset and prevalence of the conditions have not been examined systematically.

OBJECTIVE

To examine the prevalence of lower limb tendon pathology and tendinopathy in children and adolescents, and the factors associated with these conditions in this population.

METHODS

Six databases were searched (MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, Scopus, the Web of Science and the Allied and Complementary Medicine Database). Studies were included if the prevalence of lower limb tendon pathology and/or tendinopathy were reported in humans under the age of 18 years. Studies were divided according to the method of diagnosis (physical examination, ultrasound or a questionnaire) and further divided into studies that reported prevalence data by tendon [reported two data points (right and left) for each participant] and those that reported prevalence data for each participant [reporting one data point (right or left) per participant].

RESULTS

Seventeen studies met the inclusion criteria. Lower limb tendinopathy prevalence (presence of pain and dysfunction) ranged between 8.2 and 33.3%, and increased in prevalence as age increased up to 18 years. The odds ratio for studies reporting tendinopathy by tendon was 0.37 (95% confidence interval 0.20-0.69) in favour of boys presenting with tendinopathy. Study aims and reporting methods were heterogeneous.

CONCLUSIONS

The age at onset of lower limb tendinopathy in children and adolescents has not been widely studied. This systematic review found that tendinopathy is present in children and adolescents, and increases in prevalence with age up to 18 years. Male sex is significantly associated with tendinopathy in studies that report tendinopathy by tendon.

Neuropathic pain may be common in chronic lower limb tendinopathy: a prospective cohort study

BACKGROUND

To identify the prevalence of neuropathic pain, through the use of the painDETECT questionnaire, in a cohort of patients with chronic lower limb tendinopathy conditions.

METHODS

Patients with chronic lower limb tendinopathy conditions treated within a Sport and Exercise Medicine hospital clinic were identified from clinical records. At the time of the clinical consultation, pain and painDETECT scores were recorded.

RESULTS

In total, 282 suitable patients with chronic lower limb tendinopathy conditions were identified who had completed a painDETECT questionnaire. There was a median age of 51.9 years, 35% of patients were male and a median duration of symptoms of 24.0 months. There was a median score of 7.0/10 for self-reported 'average' pain and 8.0/10 for self-reported 'worst' pain. There was a median painDETECT score of 14.0, 28% of respondents scored 19 or higher with painDETECT (neuropathic component to pain may be likely), 29% scored 13-18 (equivocal result) and 43% of respondents scored 12 or less (neuropathic pain component was unlikely).

CONCLUSIONS

This study suggests that neuropathic pain as identified by the painDETECT questionnaire may be common in patients with chronic lower limb tendinopathy conditions. It is unclear if patients with tendinopathy who have neuropathic pain may have poorer outcomes from initial treatments, contributing to the high proportion seen in secondary care. These are results from a single hospital clinic, and comparison with a control group is currently lacking. However, on the results to date, neuropathic pain should be considered in management strategies in patients with chronic tendinopathy.

November 2016 Letter to the Editor-in-Chief

Letter to the Editor-in-Chief of JOSPT as follows: "Use of the VISA-P as a Clinical Measure in Research" with Authors' Response J Orthop Sports Phys Ther 2016;46(11):1012-1014. doi:10.2519/jospt.2016.0203.

Results of Surgical Treatment of Chronic Patellar Tendinosis (Jumper's Knee): A Systematic Review of the Literature

PURPOSE

To review the literature concerning surgical treatment options for chronic patellar tendinosis (jumper's knee), a common problem among athletes. When conservative treatment fails, surgical treatment is required.

METHODS

Systematic review of the literature concerning the results of current surgical treatment options for chronic patellar tendinosis. All articles of studies with an evidence level ≥IV from January 2000 until February 2015 presenting the surgical outcome after arthroscopic as well as open treatment of chronic patellar tendinosis were included. The literature research of the PubMed database was performed using the following key words: "patellar" and "tendinitis," "tendonitis," "tendinosis" or "tendinopathy"; "inferior patellar pole"; "jumper's knee"; "surgical treatment" and "open" or "arthroscopic patellar tenotomy."

RESULTS

A systematic review of the literature was performed especially to point out the effectiveness of arthroscopic treatment of chronic patellar tendinosis. The results revealed good clinical results for arthroscopic as well as open treatment of chronic patellar tendinosis that is refractory to conservative treatment in athletes. An average success rate of 87% was found for the open treatment group and of 91% for the arthroscopic treatment group. However, after open surgery, the mean time of return to the preinjury level of activity is 8 to 12 months, with a certain number of patients/athletes who cannot return to the preinjury level of activity.

CONCLUSIONS

Minimally invasive, arthroscopically assisted or all-arthroscopic procedures may lead to a significantly faster return to sporting activities and may, therefore, be the preferred method of surgical treatment.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Patellar Tendinopathy: Clinical Diagnosis, Load Management, and Advice for Challenging Case Presentations

Synopsis The hallmark features of patellar tendinopathy are (1) pain localized to the inferior pole of the patella and (2) load-related pain that increases with the demand on the knee extensors, notably in activities that store and release energy in the patellar tendon. While imaging may assist in differential diagnosis, the diagnosis of patellar tendinopathy remains clinical, as asymptomatic tendon pathology may exist in people who have pain from other anterior knee sources. A thorough examination is required to diagnose patellar tendinopathy and contributing factors. Management of patellar tendinopathy should focus on progressively developing load tolerance of the tendon, the musculoskeletal unit, and the kinetic chain, as well as addressing key biomechanical and other risk factors. Rehabilitation can be slow and sometimes frustrating. This review aims to assist clinicians with key concepts related to examination, diagnosis, and management of patellar tendinopathy. Difficult clinical presentations (eg, highly irritable tendon, systemic comorbidities) as well as common pitfalls, such as unrealistic rehabilitation time frames and overreliance on passive treatments, are also discussed. J Orthop Sports Phys Ther 2015;45(11):887-898. Epub 21 Sep 2015. doi:10.2519/jospt.2015.5987.

Factors associated with magnetic resonance imaging defined patellar tendinopathy in community-based middle-aged women: a prospective cohort study

Background

Patellar tendinopathy identified by imaging modalities has been reported in asymptomatic athletes and associated with tendon-related symptoms. However there is little data in community-based populations. The aim of this cohort study was to examine the prevalence of magnetic resonance imaging (MRI) defined patellar tendinopathy, the factors associated with this condition, and whether it was associated with knee pain in community-based middle-aged women.

Methods

One hundred seventy six women, aged 40–67 years, with no significant knee pain or injury underwent knee MRI. Patellar tendinopathy was defined on both T1- and T2-weighted fat-saturated MRIs. The cross-sectional area of vastus medialis was measured from MRI. Height and weight were measured to calculate body mass index (BMI). Physical activity was assessed using a questionnaire. Knee pain was assessed using the Western Ontario and McMaster University Osteoarthritis Index.

Results

The prevalence of MRI defined patellar tendinopathy was 30.1 %. Higher levels of physical activity (odds ratio 1.65, 95 % CI 1.09–2.51) and greater vastus medialis cross-sectional area (odds ratio 1.22, 95 % CI 1.04–1.43) were associated with increased prevalence of patellar tendinopathy, independent of age and BMI. The persistence of patellar tendinopathy was associated with the worsening of knee pain over 2 years (odds ratio 10.65, 95 % CI 1.14–99.77).

Conclusion

In community-based middle-aged women MRI-diagnosed patellar tendinopathy is common, with higher levels of physical activity and greater vastus medialis size being risk factors suggesting a biomechanical effect. Persistent patellar tendinopathy is associated with worsening of knee pain. These findings suggest that further work is needed to determine the contribution of patellar tendinopathy on knee pain and function in older people.

Lower Extremity Kinematics During a Drop Jump in Individuals With Patellar Tendinopathy

Background:

Patellar tendinopathy (PT) is a common degenerative condition in physically active populations. Knowledge regarding the biomechanics of landing in populations with symptomatic PT is limited, but altered mechanics may play a role in the development or perpetuation of PT.

Purpose:

To identify whether study participants with PT exhibited different landing kinematics compared with healthy controls.

Study Design:

Controlled laboratory study.

Methods:

Sixty recreationally active participants took part in this study; 30 had current signs and symptoms of PT, including self-reported pain within the patellar tendon during loading activities for at least 3 months and ≤80 on the Victorian Institute of Sport Assessment Scale–Patella (VISA-P). Thirty healthy participants with no history of PT or other knee joint pathology were matched by sex, age, height, and weight. Participants completed 5 trials of a 40-cm, 2-legged drop jump followed immediately by a 50% maximum vertical jump. Dependent variables of interest included hip, knee, and ankle joint angles at initial ground contact, peak angles, and maximum angular displacements during the landing phase in 3 planes. Independent-samples t tests (P ≤ .05) were utilized to compare the joint angles and angular displacements between PT and control participants.

Results:

Individuals with PT displayed significantly decreased peak hip (PT, 59.2° ± 14.6°; control, 67.2° ± 13.9°; P = .03) and knee flexion angles (PT, 74.8° ± 13.2°; control, 82.5° ± 9.0°; P = .01) compared with control subjects. The PT group displayed decreased maximum angular displacement in the sagittal plane at the hip (PT, 49.3° ± 10.8°; control, 55.2° ± 11.4°; P = .04) and knee (PT, 71.6° ± 8.4°; control, 79.7° ± 8.3°; P < .001) compared with the control group.

Conclusion:

Participants with PT displayed decreased maximum flexion and angular displacement in the sagittal plane, at both the knee and the hip. The altered movement patterns in those with PT may be perpetuating symptoms associated with PT and could be due to the contributions of the rectus femoris during dynamic movement.

Clinical Relevance:

Based on kinematic alterations in symptomatic participants, rehabilitation efforts may benefit from focusing on both the knee and the hip to treat symptoms associated with PT.

Patellar Tendinopathy

Context:

Patellar tendinopathy is a common condition. There are a wide variety of treatment options available, the majority of which are nonoperative. No consensus exists on the optimal method of treatment.

Evidence Acquisition:

PubMed spanning 1962-2014.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

The majority of cases resolve with nonoperative therapy: rest, physical therapy with eccentric exercises, cryotherapy, anti-inflammatories, corticosteroid injections, extracorporeal shockwave therapy, glyceryl trinitrate, platelet-rich plasma injections, and ultrasound-guided sclerosis. Refractory cases may require either open or arthroscopic debridement of the patellar tendon. Corticosteroid injections provide short-term pain relief but increase risk of tendon rupture. Anti-inflammatories and injectable agents have shown mixed results. Surgical treatment is effective in many refractory cases unresponsive to nonoperative modalities.

Conclusion:

Physical therapy with an eccentric exercise program is the mainstay of treatment for patellar tendinopathy. Platelet-rich plasma has demonstrated mixed results; evidence-based recommendations on its efficacy cannot be made. In the event that nonoperative treatment fails, surgical intervention has produced good to excellent outcomes in the majority of patients.

Accelerated rehabilitation following Achilles tendon repair after acute rupture - Development of an evidence-based treatment protocol

The acute rupture of the Achilles tendon is a protracted injury. Surgery is only the beginning of a long rehabilitation period. Therefore, the rehabilitation protocol is an integral aspect to restore the pre-injury activity level. Despite several trials available comparing different treatment regimes, there is still no consensus regarding the optimal protocol. Consequently, the aim of our study was to systematically search the evidence available and define a precise rehabilitation programme after operative repair of acute Achilles tendon rupture based on the trials with the highest level of evidence. We performed a systematic literature search in Medline, Embase and Cochrane library. We identified twelve randomized controlled trials comparing different treatment regimes after operative repair of the Achilles tendon. Five trials compared full to non weight bearing, all applying immobilization in equinus. Immediate full weight bearing led to significant higher patient satisfaction, earlier ambulation and return to pre-injury activity. Four trials compared early ankle mobilization to immobilization. All trials found mobilization to be superior as it shortens time to return to work and sports significantly. Three trials compared the combination of full weight bearing and early ankle mobilization to immobilization. This combination was most beneficial. Patients showed significantly higher satisfaction, less use of rehabilitation resources, earlier return to pre-injury activities and further demonstrated significantly increased calf muscle strength, reduced atrophy and tendon elongation. No study found an increased rerupture rate for the more progressive treatment. In conclusion, the rehabilitation protocol after Achilles tendon repair should allow immediate full weight bearing. After the second postoperative week controlled ankle mobilization by free plantar flexion and limited dorsiflexion at 0° should be applied.

Platelet-rich plasma: evidence for the treatment of patellar and Achilles tendinopathy--a systematic review

Platelet-rich plasma (PRP) has been introduced in the clinical practice to treat a growing number of different musculoskeletal pathologies. It is currently applied in the treatment of Achilles and patellar tendinopathies, which are common sport-related injuries very challenging to manage. Aim of the present paper was to review systematically the available clinical evidence concerning the application of PRP in the treatment of patellar and Achilles tendinopathy. A systematic review of the literature was performed according to the following inclusion criteria for relevant articles: (1) clinical reports of any level of evidence, (2) written in the English language, (3) with no time limitation and (4) on the use of PRP to treat conservatively Achilles and patellar tendinopathy. Twenty-two studies were included and analyzed. Two studies on patellar tendinopathy were randomized controlled trials (RCTs), whereas just one RCT was published on Achilles tendon. All the papers concerning patellar tendon reported positive outcome for PRP, which proved to be superior to other traditional approaches such as shock-wave therapy and dry needling. In the case of Achilles tendon, despite the encouraging findings reported by case series, the only RCT available showed no significant clinical difference between PRP and saline solution. The main finding of this study was the paucity of high-level literature regarding the application of PRP in the management of patellar and Achilles tendinopathy. However, the clinical data currently available, although not univocal, suggest considering PRP as a therapeutic option for recalcitrant patellar and Achilles tendinopathies.

Association between obesity and magnetic resonance imaging defined patellar tendinopathy in community-based adults: a cross-sectional study

Background

Patellar tendinopathy is a common cause of activity-related anterior knee pain. Evidence is conflicting as to whether obesity is a risk factor for this condition. The aim of this study was to determine the relationship between obesity and prevalence of magnetic resonance imaging (MRI) defined patellar tendinopathy in community-based adults.

Methods

297 participants aged 50–79 years with no history of knee pain or injury were recruited from an existing community-based cohort. Measures of obesity included measured weight and body mass index (BMI), self-reported weight at age of 18–21 years and heaviest lifetime weight. Fat-free mass and fat mass were measured using bioelectrical impedance. Participants underwent MRI of the dominant knee. Patellar tendinopathy was defined on both T1- and T2-weighted images.

Results

The prevalence of MRI defined patellar tendinopathy was 28.3%. Current weight (OR per kg = 1.04, 95% CI 1.01-1.06, P = 0.002), BMI (OR per kg/m² = 1.10, 95% CI 1.04-1.17, P = 0.002), heaviest lifetime weight (OR per kg = 1.03, 95% CI 1.01-1.05, P = 0.007) and weight at age of 18–21 years (OR per kg = 1.03, 95% CI 1.00-1.07, P = 0.05) were all positively associated with the prevalence of patellar tendinopathy. Neither fat mass nor fat-free mass was associated with patellar tendinopathy.

Conclusion

MRI defined patellar tendinopathy is common in community-based adults and is associated with current and past history of obesity assessed by BMI or body weight, but not fat mass. The findings suggest a mechanical pathogenesis of patellar tendinopathy and patellar tendinopathy may be one mechanism for obesity related anterior knee pain.

Surgery for unilateral and bilateral patellar tendinopathy: a seven year comparative study

PURPOSE

Open surgery for patellar tendinopathy allows patients with unilateral and bilateral tendinopathy to return to high levels of physical activity.

MATERIALS

Two groups of 23 athletes each underwent open surgical exploration for management of patellar tendinopathy. One group suffered from unilateral patellar tendinopathy (unilateral group), and the other group had bilateral (bilateral group) patellar tendinopathy. Maximum voluntary isometric contraction and anthropometric measures were assessed pre-operatively and at an average follow-up of seven years. The Victorian Institute of Sport Assessment (VISA)-P scoring system was also administered; functional outcomes were classified from excellent to poor according to a modification of Kelly's criteria.

RESULTS

At the final follow-up, in both groups, VISA-P scores were significantly improved compared with preoperative values, with no intergroup differences. Clinical results were excellent or good in 21 patients in the unilateral and 19 in the bilateral group. Twenty of 23 patients in the unilateral group and 17 of 23 in the bilateral group were still active in sports (p = 0.2). In the unilateral group, at the last follow-up, thigh volume and strength were significantly improved compared with baseline, with significant difference between operated and nonoperated limbs. In the bilateral group, there were no significant differences in thigh volume and strength between the dominant and nondominant limbs both before and after the index procedure.

CONCLUSIONS

This procedure is not technically demanding and provides a high rate of good and excellent outcomes in the long term.

A multidisciplinary approach including the use of platelet-rich plasma to treat an elite athlete with patellar tendinopathy - a case report

OBJECTIVE

Patellar tendinopathy affects a substantial proportion of athletes involved in jumping or kicking activities. Platelet rich plasma (PRP) injections may be a promising treatment used in conjunction with common traditional therapies.

CLINICAL FEATURES

Patellar tendinopathy is often the result of repetitive or excessive overload on the patellar tendon. Activity modification, cryotherapy, eccentric exercises, shockwave therapy, and PRP have been indicated as treatment options during various stages of this condition.

INTERVENTION AND OUTCOME

A 23 year old female, elite track and field athlete was managed for patellar tendinopathy with a combination of traditional therapeutic interventions as well as a PRP injection. This athlete returned to pre-injury level of competition six months post-injection.

CONCLUSION

Emerging literature on PRP appears to be promising for patellar tendinopathy, however, it remains unclear which patients may benefit most and whether the stage of the disorder has an impact on the clinical outcome.

Platelet-rich plasma for the treatment of patellar tendinopathy: clinical and imaging findings at medium-term follow-up

PURPOSE

The purpose of this study was to evaluate the efficacy of multiple platelet-rich plasma (PRP) injections on the healing of chronic refractory patellar tendinopathy, and report the quality and duration of the clinical improvement up to a medium-term follow-up.

METHODS

Forty-three patients (mean age, 30.6 years; mean BMI, 24.7; 42 men, one woman) affected by chronic patellar proximal tendinopathy were enrolled in this trial. Eleven patients were affected by bilateral tendinopathy. They underwent three ultrasound guided intra-tendinous injections of five millilitres PRP, two weeks apart from each other. Patients were prospectively evaluated initially, then after two, six, and up to mean 48.6 ± 8.1 months of follow-up (minimum evaluation at 36 months). The following evaluation tools were used: Blanzina, VISA-P, EQ-VAS for general health, and Tegner scores. Patients' overall satisfaction and time to return to sport were also reported.

RESULTS

Good and stable results were documented over time, with the VISA-P score increasing from 44.1 ± 15.6 at baseline to 61.4 ± 22.2 at two months, 76.6 ± 25.4 at six months, and 84.3 ± 21.6 at four years' follow-up. The same trend was confirmed by the other scores used, and 80 % of the patients were satisfied and returned to previous sports activities. Significantly poorer results were obtained in patients with a longer history of symptoms, and poor results were also observed in bilateral lesions. No correlation between ultrasonographic and clinical findings could be found.

CONCLUSIONS

Multiple injections of PRP provided a good clinical outcome for the treatment of chronic recalcitrant patellar tendinopathy with stable results up to medium-term follow-up. Patients affected by bilateral pathology and presenting a long history of pain obtained significantly poorer results.

Cross-cultural adaptation and measurement properties of the Brazilian Portuguese Version of the Victorian Institute of Sport Assessment-Patella (VISA-P) scale

STUDY DESIGN

Clinical measurement.

OBJECTIVES

To translate, adapt, and test the measurement properties of the Brazilian Portuguese version of the Victorian Institute of Sport Assessment-Patella (VISA-P) questionnaire.

BACKGROUND

It is important to objectively measure symptoms and functional limitations related to patellar tendinopathy using outcome measures that have been validated in the language of the target population. Cross-cultural adaptations are also useful to enhance the understanding of the measurement properties of an assessment tool, regardless of the target language.

METHODS

The VISA-P questionnaire was translated into Brazilian Portuguese, culturally adapted, and titled VISA-P Brazil. It was then administered on 2 occasions with a 24- to 48-hour interval between them, and a third time after a month of physical therapy treatment. The following measurement properties were analyzed: internal consistency, test-retest reliability, agreement, construct validity, floor and ceiling effects, and responsiveness.

RESULTS

The VISA-P Brazil had high internal consistency (Cronbach α = .76; if item deleted, Cronbach α = .69-.78), excellent reliability and agreement (intraclass correlation coefficient = 0.91; 95% confidence interval: 0.85, 0.95; standard error of measurement, 5.2 points; minimal detectable change at the 90% confidence level, 12.2 points), and good construct validity (Pearson r = 0.60 compared to Lysholm). No ceiling and floor effects were detected for the VISA-P Brazil, and the responsiveness, based on 32 patients receiving physical therapy intervention for 1 month, demonstrated a large effect size of 0.97 (95% confidence interval: 0.68, 1.25).

CONCLUSION

The VISA-P Brazil is a reproducible and responsive tool and can be used in clinical practice and research to assess the severity of pain and disability of patients with patellar tendinopathy.

A single application of low-energy radial extracorporeal shock wave therapy is effective for the management of chronic patellar tendinopathy

PURPOSE

Extracorporeal shock wave therapy (SWT) is effective for the management of chronic recalcitrant tendinopathy. The objective of the current study was to assess whether a standardized, single treatment SWT is effective for the management of chronic patellar tendinopathy

METHODS

Thirty-three patients with chronic patellar tendinopathy received low-energy SWT. Thirty-three patients with chronic patellar tendinopathy received other forms of non-operative therapy (control group). Evaluation was by change in Visual Analogue Scale (VAS), Victoria Institute of Sport Assessment score for patellar tendinopathy (VISA-P) score and by Roles and Maudsley Score.

RESULTS

Mean pre-treatment VAS scores for the control and SWT groups were 7.5 and 7.8, respectively. One month, 3 months, and 12 months after treatment, the mean VAS for the control and SWT groups were 6.7 and 4.3 (p < 0.001), 5.9 and 3.5 (p < 0.001), and 5.1 and 2.7 (p < 0.001), respectively. One month, 3 months, and 12 months after treatment, the mean VISA for the control and SWT groups were 50.7 and 65.5 (p < 0.001), 52.1 and 71 (p < 0.001), and 54.9 and 74.5 (p < 0.001), respectively. At final follow-up, the number of excellent, good, fair, and poor results for the SWT and control groups were 8 and 3 (p < 0.001), 17 and 10 (p < 0.001), 5 and 16 (p < 0.001), and 3 and 4 (p < 0.001), respectively. The percentage of patients with excellent ("1") or good ("2") Roles and Maudsley Scores (i.e. successful results) 12 months after treatment was statistically greater in the SWT group compared to the control group (p < 0.001).

CONCLUSION

A single application of radial SWT is an effective treatment for chronic patellar tendinopathy.

LEVEL OF EVIDENCE

III.

Ultrasound-guided sclerosis of neovessels in patellar tendinopathy: a prospective study of 101 patients

BACKGROUND

A randomized controlled study has shown promising clinical results after treatment with sclerosing injections in a group of patients with patellar tendinopathy, but no study has investigated medium- or long-term outcome in a large and unselected group of patients.

PURPOSE

To investigate if sclerosing treatment would affect the level of patellar tendon pain and knee function after 24 months in a large group of patients with patellar tendinopathy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This prospective study recruited patients with a clinical diagnosis of jumper's knee and visible neovascularization corresponding to the painful area on power Doppler ultrasound. They received up to a maximum of 5 ultrasound-guided sclerosing injections using polidocanol at 4- to 6-week intervals. Knee pain and function were recorded using the Victorian Institute of Sport Assessment-Patella (VISA-P) score before treatment and 6, 12, and 24 months after the first injection.

RESULTS

In total, 101 patients (15 women and 86 men) with 120 tendons were included and given from 1 to 5 sclerosing injections (mean [SD], 2.5 [0.9]). The patients reported a significantly improved VISA-P score from baseline (mean, 39; 95% confidence interval [CI], 36-42) to the 24-month follow-up (mean, 65; 95% CI, 60-70) (range, 21-100; P < .001, paired t test). However, a VISA-P score of >95 points was reported in only 22 cases (20%), whereas 37 cases (36%) reported a VISA-P score of <50 at 24 months.

CONCLUSION

Sclerosing treatment with polidocanol resulted in a moderate improvement in knee function and reduced pain in a heterogeneous group of patients with patellar tendinopathy. Nevertheless, few of the patients were cured, and the majority still had reduced function and substantial pain after 24 months of follow-up.

Training volume and body composition as risk factors for developing jumper's knee among young elite volleyball players

Training volume and body composition have been suggested as risk factors for jumper's knee among athletic youth, but research is lacking. The aim of this 4-year prospective cohort study was to examine the relationship between training and competition load, body composition, and risk for developing jumper's knee. Participants are elite volleyball players, aged 16-18 years. Training and competition load was recorded continuously and body composition semiannually. Jumper's knee was diagnosed on a standardized clinical examination. We recruited 141 healthy students (69 males and 72 females), and 28 developed jumper's knee (22 boys and six girls). In a multivariate analyses, boys had three to four times higher risk compared with girls. Volleyball training had an odds ratio (OR) 1.72 (1.18-2.53) for every extra hour trained, and match exposure was the strongest sports-related predictor for developing jumper's knee with an OR of 3.88 (1.80-8.40) for every extra set played per week. We did not detect any significant differences between the groups in body composition at the time of inclusion or in the change of body composition during the study period. Conclusion, male gender, a high volume of volleyball training and match exposure were risk factors for developing jumper's knee.

Low range of ankle dorsiflexion predisposes for patellar tendinopathy in junior elite basketball players: a 1-year prospective study

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.

Skin-derived tenocyte-like cells for the treatment of patellar tendinopathy

BACKGROUND

Recent research of lateral elbow tendinopathy has led to the use of laboratory-amplified tenocyte-like cells.

HYPOTHESIS

Ultrasound-guided injection of autologous skin-derived tendon-like cells are effective compared with other injectable therapies for the treatment of refractory patellar tendinosis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

From 60 patellar tendons in 46 patients with refractory patellar tendinopathy, a 4-mm skin biopsy was sampled to grow tenocyte-like collagen-producing cells. Patients were allocated into 2 groups: (1) injection with laboratory-prepared, amplified collagen-producing cells derived from dermal fibroblasts and suspended in autologous plasma from centrifuged autologous whole blood or (2) injection with autologous plasma alone. Injections were made into the sites of hypoechogenicity, intrasubstance tears, and fibrillar discontinuity within the patellar tendon. The Victorian Institute of Sport Assessment (VISA) score was used to assess pain, severity, and functional disability. Ultrasound was performed to assess structural and blood flow changes, evaluating 4 criteria: tendon thickness, hypoechogenicity, intrasubstance tears, and neovascularity.

RESULTS

In the cell group, mean VISA scores improved from 44 ± 15 before treatment to 75 ± 17 at 6 months; in the plasma group, from 50 ± 18 to 70 ± 14. Estimated average difference between groups was 8.1, a significantly higher score in the cell group. Patients treated with collagen-producing cells also had significantly faster improvement and a highly significant effect of treatment, with the difference between groups estimated as 2.5 per unit increase in 1/√time. One patient treated with cell therapy had a late rupture and progressed to surgery; histopathology showed normal tendon structure.

CONCLUSION

Ultrasound-guided injection of autologous skin-derived tendon-like cells can be safely used in the short term to treat patellar tendinopathy, with faster response of treatment and significantly greater improvement in pain and function than with plasma alone.

Scleraxis expression is coordinately regulated in a murine model of patellar tendon injury

This study investigated the expression of Scleraxis in a murine model of patellar tendon injury in which the central third of the patellar tendon was unilaterally injured. The presence of tendon pathology was assessed using dual photon microscopy, conventional histology and microCT. Tendon pathology was also quantified noninvasively over a 12-week period using high-frequency ultrasound and laser Doppler flowmetry. Gene expression (Scx, Tnmd, and Col1a1) was determined at defined end-points (1, 4, 8, and 12 weeks) using qPCR on RNA from individual patellar tendons on injured and uninjured sides. There was significant development of tendon pathology as gauged by ultrasound and laser Doppler over 12 weeks. Injured tendons demonstrated significant histological and microCT evidence of pathological change, and disorganized collagen with reduced density. The expression of Scx and Col1a1 was unchanged at 1 week, significantly upregulated at 4 and 8 weeks, and had returned to baseline by 12 weeks. Tnmd expression was unchanged at 1 week, and significantly increased at 4, 8, and 12 weeks. Patellar tendon injury was associated with marked increases in the expression of Scx, Tnmd, and Col1a1. Our data suggest new roles for Scleraxis in coordinating the response to injury in the pathogenesis of tendon disorders.

Efficacy of an inertial resistance training paradigm in the treatment of patellar tendinopathy in athletes: a case-series study

STUDY DESIGN

Case-series study with pre- vs. post-test measurements design.

BACKGROUND

Strength training programs emphasizing eccentric muscle actions have received much attention in the treatment of tendinopathies. The current study reports on the efficacy of a novel strength training paradigm using inertial eccentric-concentric resistance to treat chronic patellar tendinopathy.

CASE DESCRIPTION

Ten athletes with chronic patellar tendinopathy (15 tendons) volunteered for the study. Subjects completed a 6-week training program employing a leg press flywheel ergometer. Pre and post measurements assessed lower limb maximal strength and vertical counter-movement-jump (CMJ) height. Surface electromyography (SEMG) analysis of paraspinal, rectus femoris, biceps femoris and medial gastrocnemius muscles were collected. All measurements were performed one week before and after the training period. Clinical measures of pain and tendon function were assessed by means of a visual analogue scale (VAS) and a patellar tendinopathy questionnaire (VISA) at baseline, post-training and follow-up (12 wk). The Wilcoxon signed-rank test was employed for data comparisons.

RESULTS

Eccentric strength increased after training (90%, p < 0.05). Similarly, VAS and VISA scores improved after training as well (60% and 86%, respectively, p < 0.01). There were no changes in CMJ height.

CONCLUSION

Short-term training using inertial eccentric overload, resulted in improved muscle function and reduced subjective pain in long-lasting patellar tendinopathy.

Fibril morphology and tendon mechanical properties in patellar tendinopathy: effects of heavy slow resistance training

BACKGROUND

Patellar tendinopathy is characterized by pathologic abnormalities. Heavy slow resistance training (HSR) is effective in the management of patellar tendinopathy, but the underlying functional mechanisms remain elusive.

PURPOSE

To investigate fibril morphology and mechanical properties in patellar tendinopathy and the effect of HSR on these properties.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Eight male patients with patellar tendinopathy completed 12 weeks of HSR. Nine healthy subjects served as controls. Assessments were conducted at baseline and at 12 weeks. Patients assessed symptoms/function and maximal tendon pain during activity. Tendon biopsy samples were analyzed for fibril density, volume fraction, and mean fibril area. Tendon mechanical properties were assessed using force and ultrasonography samplings.

RESULTS

Patients improved in symptoms/function (P = .02) and maximal tendon pain during activity (P = .008). Stiffness and modulus of control and tendinopathy tendons were similar at baseline. Stiffness remained unaffected in control tendons (3487 +/- 392 to 3157 +/- 327 N/mm, P = .57) but declined in tendinopathic tendons at 12 weeks (3185 +/- 187 to 2701 +/- 201 N/mm, P = .04). At baseline, fibril volume fraction was equal, fibril density smaller (P = .03), and mean fibril area tended to be higher in tendinopathy versus controls (P = .07). Fibril morphology remained unchanged in controls but fibril density increased (70% +/- 18%, P = .02) and fibril mean area decreased (-26% +/- 21%, P = .04) in tendinopathic tendons after HSR.

CONCLUSION

Fibril morphology is abnormal in tendinopathy, but tendon mechanical properties are not. Clinical improvements after HSR were associated with changes in fibril morphology toward normal fibril density and mean fibril area. Heavy slow resistance training improved the clinical outcome of patellar tendinopathy, and these improvements were associated with normalization of fibril morphology, most likely due to a production of new fibrils.

Platelet-rich plasma: new clinical application: a pilot study for treatment of jumper's knee

This study describes a simple, low-cost, minimally invasive way to apply PRP growth factors to chronic patellar tendinosis; 20 male athletes with a mean history of 20.7 months of pain received treatment, and outcomes were prospectively evaluated at 6 months follow-up. No severe adverse events were observed, and statistically significant improvements in all scores were recorded. The results suggest that this method may be safely used for the treatment of jumper's knee, by aiding the regeneration of tissue which otherwise has low healing potential.

Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy

A randomized-controlled single-blind trial was conducted to investigate the clinical, structural and functional effects of peritendinous corticosteroid injections (CORT), eccentric decline squat training (ECC) and heavy slow resistance training (HSR) in patellar tendinopathy. Thirty-nine male patients were randomized to CORT, ECC or HSR for 12 weeks. We assessed function and symptoms (VISA-p questionnaire), tendon pain during activity (VAS), treatment satisfaction, tendon swelling, tendon vascularization, tendon mechanical properties and collagen crosslink properties. Assessments were made at 0 weeks, 12 weeks and at follow-up (half-year). All groups improved in VISA-p and VAS from 0 to 12 weeks (P<0.05). VISA-p and VAS improvements were maintained at follow-up in ECC and HSR but deteriorated in CORT (P<0.05). In CORT and HSR, tendon swelling decreased (-13+/-9% and -12+/-13%, P<0.05) and so did vascularization (-52+/-49% and -45+/-23%, P<0.01) at 12 weeks. Tendon mechanical properties were similar in healthy and injured tendons and were unaffected by treatment. HSR yielded an elevated collagen network turnover. At the half-year follow-up, treatment satisfaction differed between groups, with HSR being most satisfied. Conclusively, CORT has good short-term but poor long-term clinical effects, in patellar tendinopathy. HSR has good short- and long-term clinical effects accompanied by pathology improvement and increased collagen turnover.

Jumper's knee in volleyball athletes: advancements in diagnosis and treatment

Jumper's knee, or patellar tendinopathy, affects nearly one half of elite volleyball athletes and causes significant morbidity. The diagnosis and treatment of jumper's knee is evolving with heavier reliance on the use of diagnostic ultrasound with and without color or power Doppler. Research suggests that conservative treatment is very effective using an eccentric exercise regimen and decline squats. Interventional treatments are expanding as well, with positive results seen using extracorporeal shock wave therapy and polidocanol sclerosing injections. Arthroscopic surgical approaches are being developed, some using intra-operative ultrasound guidance. The findings of several recent basic science studies imply that the future may lie in developing a greater understanding of, and then possibly modulating the balance of, the local neuronal, vascular, or biochemical factors associated with symptomatic patellar tendinopathy.

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.