Recalcitrant patellar tendinitis. Magnetic resonance imaging, histologic evaluation, and surgical treatment

Surgical treatment of chronic proximal patellar tendon tears grades 3 and 4 using augmentation with quadriceps tendon-bone graft

BACKGROUND

Chronic proximal patellar tendinosis with partial tendon tears represents a multifactorial overuse injury. Several surgical techniques have been described with various outcomes and the return to sports may fail.

HYPOTHESIS

Reconstruction of the proximal patellar tendon with augmentation using a quadriceps tendon-bone (QTB) graft improves knee function in patients presenting with proximal patellar tendinosis and partial tendon tears.

METHODS

Forty-seven patients (32 males, 15 females) with chronic proximal patellar tendinosis and tendon tears grade 3 and 4 were treated between 1992 and 2018. Patients were evaluated retrospectively using the Popkin-Golman (PG) MRI grading system and the removed tendon parts. The Tegner Activity Scale (TAS) and the Numerical Rating Scale (NRS) for pain were used as outcome measures before surgery and at follow up. Complete data were available in 100% of cases at 6 months follow up, and fifteen of them at later follow up.

RESULTS

The average follow up was 1.5 years (range, 0.5-16). The TAS improved from a mean preoperative score of 3.7 to a mean postoperative score of 9.1. The median NRS status decreased from an average of 6.4 to 1.1. Two patients needed additional arthroscopic scar tissue removal.

CONCLUSION

Reconstruction of proximal patellar tendon tears grades 3 and 4 with augmentation using a QTB graft is a valuable surgical salvage procedure in chronic cases. It improves knee function and yields good to excellent results in most cases including high level athletes. The use of MRI with the PG classification of tendon tears is highly recommended.

LEVEL OF EVIDENCE

Therapeutic case series, Level IV.

Current Concepts in Patellar Tendinopathy: An Overview of Imaging, Pathogenesis, and Nonoperative and Operative Management

» Approximately 1 in 3 high-impact athletes develops patellar tendinopathy (PT), with the proximal insertion of the patellar tendon being the most commonly affected anatomical site.» Nonoperative treatment options are effective in reducing pain and restoring functionality in most patients with PT. However, operative intervention should be considered when conservative management fails.» A comprehensive review of the literature on surgical procedures, including both open and arthroscopic approaches, was conducted with a specific focus on clinical outcomes and return to sports.» Both open surgery and arthroscopic surgery for PT have demonstrated favorable success rates and return-to-sport outcomes, with arthroscopic treatment potentially expediting the recovery process.

Are the Pathologic Features of Enthesopathy, Tendinopathy, and Labral and Articular Disc Disease Related to Mucoid Degeneration? A Systematic Review

BACKGROUND

Tendinopathy, enthesopathy, labral degeneration, and pathologic conditions of the articular disc (knee meniscus and ulnocarpal) are sometimes described in terms of inflammation or damage, while the histopathologic findings are often consistent with mucoid degeneration. A systematic review of the histopathology of these structures at diverse locations might reconceptualize these diseases as expected aspects of human aging. The potential benefits of this evolution might include healthier patient and clinician mindsets as well as a reduced likelihood of overdiagnosis and overtreatment resulting from greater awareness of base rates of pathology.

QUESTION/PURPOSE

In this systematic review of studies of surgical specimens, we asked: Are there are any differences in the histopathologic findings of structural soft tissue conditions (mucoid degeneration, inflammation, and vascularity) by anatomic site (foot, elbow, or knee) or structure (tendon body, muscle or tendon origin or insertion [enthesis], labrum, or articular disc)?

METHODS

Studies between 1980 and 2021 investigating the histopathologic findings of specimens from surgery for trigger digit, de Quervain tendinopathy, plantar fasciitis, lateral and medial elbow enthesopathy, rotator cuff tendinopathy, posterior tibial tendinopathy, patellar tendinopathy, Achilles tendinopathy, or disease of the hip labrum, ulnocarpal articular disc, or knee meniscus were searched for in the PubMed, EMBASE, and CINAHL databases. Inclusion criteria were the prespecified anatomic location or structure being analyzed histologically and any findings described with respect to inflammation, vascularity, or mucoid degeneration. Studies were excluded if they were nonhuman studies or review articles. Search terms included "anatomy," "pathology," and "histopathology." These terms were coupled with anatomic structures or disorders and included "trigger finger," "de Quervain," "fasciitis, plantar," "tennis elbow," "rotator cuff tendinopathy," "elbow tendinopathy," "patellar tendonitis," "posterior tibial tendon," and "triangular fibrocartilage." This resulted in 3196 studies. After applying the inclusion criteria, 559 articles were then assessed for eligibility according to our exclusion criteria, with 52 eventually included. We recorded whether the study identified the following histopathologic findings: inflammatory cells or molecular markers, greater than expected vascularity (categorized as quantitative count, with or without controls; molecular markers; or qualitative judgments), and features of mucoid degeneration (disorganized collagen, increased extracellular matrix, or chondroid metaplasia). In the absence of methods for systematically evaluating the pathophysiology of structural (collagenous) soft tissue structures and rating histopathologic study quality, all studies that interpreted histopathology results were included. The original authors' judgment regarding the presence or absence of inflammation, greater than expected vascularity, and elements of mucoid degeneration was recorded along with the type of data used to reach that conclusion.

RESULTS

Regarding differences in the histopathology of surgical specimens of structural soft tissue conditions by anatomic site, there were no differences in inflammation or mucoid degeneration, and the knee meniscus was less often described as having greater than normal vascularity. There were no differences by anatomic structure. Overall, 20% (10 of 51) of the studies that investigated for inflammation reported it (nine inflammatory cells and one inflammatory marker). Eighty-three percent (43 of 52) interpreted increased vascularity: 40% (17 of 43) using quantitative methods (14 with controls and three without) and 60% (26 of 43) using imprecise criteria. Additionally, 100% (all 52 studies) identified at least one element of mucoid degeneration: 69% (36 of 52) reported an increased extracellular matrix, 71% (37 of 52) reported disorganized collagen, and 33% (17 of 52) reported chondroid metaplasia.

CONCLUSION

Our systematic review of the histopathology of diseases of soft tissue structures (enthesopathy, tendinopathy, and labral and articular disc) identified consistent mucoid degeneration, minimal inflammation, and imprecise assessment of relative vascularity; these findings were consistent across anatomic sites and structures, supporting a reconceptualization of these diseases as related to aging (senescence or degeneration) rather than injury or activity.

CLINICAL RELEVANCE

This reconceptualization supports accommodative mindsets known to be associated with greater comfort and capability. In addition, awareness of the notable base rates of structural soft tissue changes as people age might reduce overdiagnosis and overtreatment of incidental, benign, or inconsequential signal changes and pathophysiology.

Efficacy of ultrasound guided dry needling as an adjunct to conventional physical therapy for patients with jumper’s knee: A randomized controlled trial

Background

Jumper’s knee is a degenerative condition among athletes, and it has been treated with conventional physical therapy (CPT). Ultrasound guided dry needling (USG-DN) is a relatively new technique to explore clinical outcomes in patients with tendinopathy.

Methods

This parallel group, single-blinded randomized controlled trial was carried out involving 94 athletes with clinically diagnosed jumper’s knee, divided into an intervention group (USG-DN + CPT, n = 47) and a control group (CPT, n = 47). Participants received a 4-week programme; the intervention group received ultrasound guided patellar tendon dry needling (DN) in conjunction with CPT. The control group received only CPT. The visual analog scale (VAS), Victorian institute of sports assessment-Patellar tendinopathy (VISA-P) questionnaire, Lysholm scale, Knee injury and osteoarthritis outcome score (KOOS) and ultrasonographic features of patellar tendinopathy were evaluated at baseline,1 week, 2 weeks, and 4 weeks. The data were analyzed through SPSS-26.

Results

The study found statistically significant differences (P < 0.05) regarding VAS, Lysholm, VISA-P, and KOOS scales at baseline, 1st, 2nd, and 4th week post-intervention. Within-group differences also showed statistically significant results after the intervention. There were significant results observed in ultrasonographic outcomes between both groups at 1 month post-intervention (all P < 0.05).

Conclusion

The results of the current study suggest, ultrasound guided DN of patellar tendon in combination with CPT reduced pain, improved function, and showed a tendency to decrease tendon thickness in patients with patellar tendinopathy.

Clinical Trial Registration Number

(IRCT20210409050913N1). Dated: 17.04.2021. https://www.irct.ir/user/trial/55607/view.

Bioinductive Collagen Implant Augmentation for the Repair of Chronic Lower Extremity Tendinopathies: A Report of Two Cases

In this report, we present two cases of refractory chronic lower extremity tendinopathies treated with collagen bioinductive implant augmentation: a 20-year-old male football player with chronic patellar tendinopathy and a 40-year-old active female with chronic proximal hamstring tendinopathy. We demonstrate that bioaugmentation may represent an effective strategy in the surgical treatment of chronic tendinopathies. Both patients were able to return to their pre-injury activity levels at an accelerated rate.

Percutaneous ultrasonic tenotomy effectively debrides tendons of the extensor mechanism of the knee: A technical note

BACKGROUND

Percutaneous ultrasonic tenotomy (PUT) is a minimally-invasive method of treating patellar tendinosis, but its immediate effect on tendon structure has never been studied. Given the crucial nature of the extensor mechanism of the knee, it is important to understand the procedure's effect on tendon structure prior to clinical implementation. The aim of this study was to analyze the tendon structure of the extensor mechanism of the knee after PUT in a cadaveric model.

METHODS

Four fresh-frozen cadaveric specimens (two patellar and two quadriceps tendons) underwent PUT. The tendons were then sectioned and stained with hematoxilin & eosin (H&E). The sections were analyzed for a clear area of debridement. The area of debridement was calculated as an average of three measurements.

RESULTS

All four tendons demonstrated a clear area of debridement limited to the treatment area without damaging any surrounding tissue. The area of debridement for the patellar and quadriceps tendons treated was 2.89 mm2, 1.5 mm2, 2.98 mm2 and 7.29 mm2, respectively.

CONCLUSIONS

Percutaneous ultrasonic tenotomy effectively debrided the treatment area in all tendons without damaging surrounding tissue. Further work is needed to report clinical outcomes, assess the risk of post-procedure tendon rupture and define return-to-sport progression.

A systematic review of inflammatory cells and markers in human tendinopathy

BACKGROUND

This article systematically reviews the current evidence regarding inflammation in Tendinopathy with the aim to increase understanding of a potential common pathophysiology.

METHODS

Following the PRISMA statements, the terms: (tendinopathy OR (tendons AND rupture)) AND (inflammation OR (inflammation AND cells) OR immune system OR inflammation mediators OR bacteria) were used. One thousand four hundred thirty-one articles were identified which was screened down to 53.

RESULTS

39/53 studies mentioned inflammatory cells but had contradicting conclusions. Macrophages were the most common cell type and inflammatory markers were detectable in all the articles which measure them.

CONCLUSIONS

The included studies show different conclusions, but this heterogeneity is not unexpected since the clinical criteria of 'tendinopathy' encompass a huge clinical spectrum. Different 'tendinopathy' conditions may have different pathophysiology, and even the same clinical condition may be at different disease stages during sampling, which can alter the histological and biochemical picture. Control specimen sampling was suboptimal since the healthy areas of the pathological-tendon may actually be sub-clinically diseased, as could the contralateral tendon in the same subject. Detection of inflammatory cells is most sensitive using immunohistochemistry targeting the cluster of differentiation markers, especially when compared to the conventional haematoxylin and eosin staining methods. The identified inflammatory cell types favour a chronic inflammatory process; which suggests a persistent stimulus. This means NSAID and glucocorticoids may be useful since they suppress inflammation, but it is noted that they may hinder tendon healing and cause long term problems. This systematic review demonstrates a diversity of data and conclusions in regard to inflammation as part of the pathogenesis of Tendinopathy, ranging from ongoing or chronic inflammation to non-inflammatory degeneration and chronic infection. Whilst various inflammatory markers are present in two thirds of the reviewed articles, the heterogenicity of data and lack of comparable studies means we cannot conclude a common pathophysiology from this systematic review.

Surgical Technique for Chronic Proximal Patellar Tendinopathy (Jumper's Knee)

Chronic proximal patellar tendinopathy is a challenging condition for its troublesome management in the active patient and difficulty in defining the failure of conservative treatment to indicate surgery. Usually, patients with chronic proximal patellar tendinopathy have already tried several physiotherapeutic modalities and are away from their preferred physical activities for variable periods. The current literature presents some open and even arthroscopic options for treating recalcitrant patellar tendinopathy using a variable magnitude of resources and costs. The purpose of this article was to depict a very simple and inexpensive surgical option for treating this condition, which can be applied worldwide.

Radiographic and ultrasonographic changes of the patellar ligament following tibial tuberosity advancement in 25 dogs

Introduction: Patellar ligament thickening is a recognized response following osteotomy of the proximal tibia as a treatment for cranial cruciate disease. In humans this is seen as a response to increased loading, but the reason for this thickening in dogs is unclear. A prospective study was undertaken to assess the degree and frequency of patellar ligament desmopathy in 25 consecutive cases undergoing tibial tuberosity advancement (TTA).

Objectives: To determine the incidence of patellar ligament thickening following TTA.

Methods: Consecutive cases undergoing TTA had ultrasonographic and radiographic measurements performed of the patellar ligament, at multiple positions on the ligament. This was performed at the time of surgery, and at six weeks and six months (ultrasound only) following surgery. The radiographic measurements were performed by two reviewers who were blinded to the timeframe of each image.

Results: There was great variation in both the incidence and degree of thickening of the ligament. Fifty percent of the cases showed no changes in the thickness of the patellar ligament. A clinical pain response was not associated with patellar ligament thickening. No statistically significant variables which predicted the development of patellar ligament thickening were identified .

Clinical significance: The presence of signs of patellar ligament thickening is of questionable clinical significance and is probably an incidental finding.

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.

Prognostic value of MRI in arthroscopic treatment of chronic patellar tendinopathy: a prospective cohort study

Background

To date, prognostic outcome factors for patients undergoing arthroscopic treatment due to chronic patellar tendinopathy (PT) are lacking. The purpose of this study was to investigate whether preoperatively assessed MRI parameters might be of prognostic value for prediction of functional outcome and return to sports in arthroscopic treatment of chronic PT.

Methods

A prospective cohort study was conducted including 30 cases (4 female and 24 male competitive athletes) undergoing arthroscopic patellar release (APR) due to chronic PT. The mean age was 28.2 years (range, 18–49 years) at the time of surgery, and the mean follow-up period was 4.2 years (range, 2.2–10.4 years). Preoperatively assessed MRI parameters included bone marrow edema (BME) of the inferior patellar pole, patellar tendon thickening, infrapatellar fat pad (IFP) edema, and infrapatellar bursitis. Prevalences of preoperative MRI findings were correlated to functional outcome scores in order to determine statistically significant predictors.

Results

All athletes regained their preinjury sports levels. Athletes featuring preoperative IFP edema showed significantly inferior modified Blazina score (0.6 ± 0.7 vs. 0.2 ± 0.5), single assessment numeric evaluation (SANE; 86.0 ± 8.8 vs. 94.3 ± 7.5), and Visual Analogue Scale (VAS; 1.0 ± 1.2 vs. 0.3 ± 0.8) compared to subjects without IFP edema (p < 0.05). Return to sports required a mean of 4 ± 3.2 months. On average, patients with IFP edema needed significantly more time to return to sports than subjects without IFP edema (6.5 vs 2.8 months; p < 0.05). The simultaneous presence of BME and IFP edema was associated with significantly inferior outcomes by means of the Victorian Institute of Sport Assessment questionnaire for patients with patellar tendinopathy (VISA-P; 88.1 ± 11.9 vs. 98.6 ± 4.2), SANE (84.3 ± 10.2 vs. 93.1 ± 8.3), and VAS (1.3 ± 1.4 vs. 0.3 ± 0.9) compared to an isolated BME or isolated IFP edema.

Conclusions

This is the first study identifying prognostic outcome factors in arthroscopic treatment of chronic PT. Preoperative IFP edema alone or simultaneous BME and IFP edema on preoperative MRI were associated with inferior functional outcome and delayed return to sports. Knowledge of these predictive factors might improve risk stratification, individualize treatment and postoperative rehabilitation, and contribute to improve clinical outcome. Moreover, current findings offer the potential for novel therapeutic approaches.

Open Patellar Tendon Tenotomy and Debridement Combined with Suture-bridging Double-row Technique for Severe Patellar Tendinopathy

OBJECTIVE

To create a new surgical procedure for chronic severe patellar tendinopathy and to evaluate its clinical efficacy.

METHODS

In this retrospective study, the data of 12 patients with severe patellar tendinopathy in 14 knees who had undergone surgical treatment at Beijing Chao-Yang Hospital between 1 March 2009 and 1 August 2013 were analyzed. Inclusion criteria included severe patellar tendinopathy (Phase III), conservative therapy for more than 6 months, American Society of Anesthesiology status Grade I-II, and body mass index <30. Patients with severe osteoporosis, complete tendon disruption (Phase IV) and those who were unable to cooperate were excluded. There were 8 men (10 knees) and 4 women (4 knees) cases. The patients' ages ranged from 38 to 54 years (mean, 45.3 years). All surgeries had been performed by the same physician. Surgical treatment comprised incising open patellar midline tenotomy, complete debridement and suture-bridging double-row fixation. Isotonic and kinetic chain exercises were implemented after the second post-operative week. A gradual increase to full weight-bearing was allowed after the third post-operative week and a gradual return to unrestricted use of the leg after the eighth post-operative week. Preoperative and postoperative visual analogue scale (VAS) scores and Lysholm knee scores were obtained from the medical records or at recent postoperative follow-up visits and the results compared using Student's two-tailed paired t-test.

RESULTS

VAS scores decreased by a mean of 6.7 points (range, 1.1-7.8 points) during follow-up (minimum duration 14 months; range, 14-44 months) and Lysholm scores increased from 55.7 ± 6.5 points to 90.4 ± 6.2 points. Three cases (4 knees) achieved excellent outcomes (≥95 points) and 9 cases (10 knees) good outcomes (range, 86-94 points). No intraoperative or postoperative complications occurred. There were significant differences between preoperative and postoperative VAS and Lysholm scores (P < 0.01).

CONCLUSIONS

All study patients achieved good or excellent outcomes. No patellar tendon rupture or suture fixation failure occurred during follow-up. Suture-bridging double-row fixation is a simple and reliable method that not only improves patients' clinical symptoms, but also restores knee joint function.

Evaluation of Knee Pain in Athletes: A Radiologist's Perspective

Lower limb injuries account for most of all injuries suffered by athletes and the knee joint accounts for over half of these. The etiology of knee pain is multifactorial; a good history focusing on the mechanism of injury and the chronicity of pain is extremely useful in correlating with radiologic findings and establishing a clinically meaningful diagnosis. This review article will discuss several important and common causes of acute and chronic knee pain in athletes, focusing on their mechanism of injury and site of pain as well as their salient imaging findings.

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.

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.

Clinical results after ultrasound-guided intratissue percutaneous electrolysis (EPI®) and eccentric exercise in the treatment of patellar tendinopathy

PURPOSE

To investigate the outcome of ultrasound (US)-guided intratissue percutaneous electrolysis (EPI(®)) and eccentric exercise in the treatment of patellar tendinopathy during a long-term follow-up.

METHODS

Forty patients with patellar tendinopathy were prospectively evaluated over a 10-year follow-up period. Pain and function were evaluated before treatment, at 3 months and at 2, 5 and 10 years using the Victorian Institute of Sport Assessment-Patella (VISA-P) score, the Tegner score and Blazina's classification. According to VISA-P score at baseline, patients were also dichotomized into Group 1 (<50 points) and Group 2 (≥50 points). There were 21 patients in Group 1 and 19 in Group 2. Patient satisfaction was measured according to the Roles and Maudsley score.

RESULTS

The VISA-P score improved globally by 41.2 points (p < 0.01) after a mean 4.1 procedures. In Group 1, VISA-P score improved from 33.1 ± 13 to 78.9 ± 14.4 at 3-month and to 88.8 ± 10.1 at 10-year follow-up (p < 0.001). In Group 2, VISA-P score improved from 69.3 ± 10.5 to 84.9 ± 9 at 3-month and to 96.0 ± 4.3 at 10-year follow-up (p < 0.001). After 10 years, 91.2 % of the patients had a VISA-P score >80 points. The same level (80 % of patients) or the Tegner score at no more than one level lower (20 % of patients) was restored, and 97.5 % of the patients were satisfied with the procedure.

CONCLUSION

Treatment with the US-guided EPI(®) technique and eccentric exercises in patellar tendinopathy resulted in a great improvement in knee function and a rapid return to the previous level of activity after few sessions. The procedure has proved to be safe with no recurrences on a long-term basis.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

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.

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.

Open versus arthroscopic surgical treatment of chronic proximal patellar tendinopathy. A systematic review

PURPOSE

A general agreement on the best surgical treatment option of chronic proximal patellar tendinopathy is still lacking. The purpose of this systematic review was to investigate if arthroscopically assisted procedures have been reported better results compared to open surgery and to assess the methodology of studies.

METHODS

Twenty-one studies were included in the review. Surgical outcomes were defined referring to the functional classification described by Kelly et al. (Am J Sports Med 12(5):375-380, [11]): return to sport was regarded as the ability of training at the original level before injury with mild or moderate pain and success as the improvement after surgery with symptom reduction. Methodological analysis was performed by two reviewers adopting the Coleman Methodology Score (CMS) (range 0-100, best score 100).

RESULTS

Only one randomized controlled trial (RCT) met inclusion criteria; all other included studies were case series. Median sample size 24, range 11-138, mean age at surgery 26.8 ± 3.2 years, mean follow-up 32.5 ± 18.4 (median 31, range 6-60) months. Return to sport rate: global 78.5 %, open group 76.6 % and arthroscopic group 84.2 %. Success rate: global 84.6 %, open group 87.2 % and arthroscopic group 92.4 %. Differences between groups were not statistically significant. CMSs were positively correlated with the year of publication (P < 0.05).

CONCLUSIONS

Minimally invasive arthroscopically assisted procedures have not reported better statistically significant results when compared to open surgery in the treatment of chronic proximal patellar tendinopathy. The methodology of studies in this field has improved over the past 15 years, but well-designed RCTs using validated patient-based outcome measures are still lacking.

LEVEL OF EVIDENCE

Systematic Review, Level IV.

The aging athlete: part 1, "boomeritis" of the lower extremity

OBJECTIVE

The purpose of this review is to describe the physiologic changes that occur in the musculoskeletal system during aging and the common injuries that occur in the lower extremity as a consequence of these changes. Several clinical presentations are addressed, and their differential diagnoses are discussed with an emphasis on the most likely injury for each presentation.

CONCLUSION

A unique quality of the newly aging group of people referred to as baby boomers is their expectation to continue exercising as they grow older, thus the incidence of exercise-induced injuries among older people is increasing. The concepts behind factors that predispose older athletes to certain pathologic conditions that affect the muscles, tendons, and bones of the lower extremity must be understood.

Tendinosis: pathophysiology and nonoperative treatment

Tendinosis is a troublesome clinical entity affecting many active people. Its treatment remains a challenge to sports medicine clinicians. The etiopathophysiology of tendinosis has not been well delineated. The known pathophysiology and the recent advances in the understanding of the etiologic process of tendinosis are discussed here, including new concepts in mechanotransduction and the biochemical alterations that occur during tendon overload. The optimal, nonoperative treatment of tendinosis is not clear. This article reviews recent evidence of the clinical efficacy of the following interventions: eccentric exercise, extracorporal shock wave treatment, corticosteroid and nonsteroidal anti-inflammatory medications, sclerosing injections, nitric oxide, platelet-rich plasma injections, and matrix metalloproteinase inhibitors. Eccentric exercise has strongest evidence of efficacy. Extracorporal shock wave treatment has mixed evidence and needs further study of energy and application protocols. Sclerosing agents show promising early results but require long-term studies. Corticosteroid and nonsteroidal anti-inflammatory medications have not been shown to be effective, and many basic science studies raise possible concerns with their use. Nitric oxide has been shown in several basic science studies to be promising, but clinical efficacy has not been well established. More clinical trials are needed to assess dosing, indications, and clinical efficacy of nitric oxide. Platelet-rich plasma injections have offered encouraging short-term results. Larger and longer-term clinical trials are needed to assess this promising modality. Matrix metalloproteinase inhibitors have had few clinical studies, and their role in the treatment of tendinosis is still in the early phase of investigation.

The aging athlete: part 2, "boomeritis" of the upper extremity

OBJECTIVE

The purpose of this review is to describe the upper extremity injuries that frequently accompany aging, the typical clinical presentations, and the differential diagnoses with an emphasis on the injury most likely encountered with each presentation.

CONCLUSION

Expectation of continued participation in exercise and sports activities by the baby boomer population has presented new challenges to the medical field. The concepts behind factors that predispose older athletes to certain pathologic conditions that affect the muscles, tendons, and bones of the upper extremity must be understood.

Can arthroscopically assisted treatment of chronic patellar tendinopathy reduce pain and restore function?

BACKGROUND

Patellar tendinopathy is a common source of pain in athletes, especially those involved in sports with a high incidence of jumping and cutting. Changes in training programs and exercises based on eccentric quadriceps contractions often relieve patients' symptoms. For athletes unresponsive to this treatment, some authors suggest open and arthroscopic procedures débriding either the tendon alone, or the tendon and bone.

QUESTIONS/PURPOSES

We asked whether an arthroscopically assisted approach to débride not only the tendon, bone, but also the peritenon could relieve pain and allow athletes to return to their former activities.

PATIENTS AND METHODS

We retrospectively reviewed 23 patients with a history of at least 6 months of painful patellar tendinopathy unresponsive to nonoperative treatment treated with an arthroscopic technique that débrided the tendon, inferior pole of the patella, and peritenon: 22 males and one female. Mean age was 29 years. Patients were evaluated using the anterior knee pain score of Kujala et al. The minimum followup was 12 months (mean, 58 months; range, 12-121 months).

RESULTS

Twelve patients scored 100, one 99, one 98, five 97, two 94, one 90, and one 64. The Kujala et al. mean score was 96 (range, 64-100). All but four patients returned to their former sports activities. We observed no complications.

CONCLUSIONS

Arthroscopic treatment can relieve the pain of refractory chronic patellar tendinopathy. Our observations were comparable with those previously reported for open techniques and a high percentage of patients returned to their previous activity level.

LEVEL OF EVIDENCE

Level IV, observational study. See Guidelines for Authors for a complete description of levels of evidence.

Foot posture and patellar tendon pain among adult volleyball players

OBJECTIVE

We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot.

DESIGN

Observational study.

SETTING

Field-based study among competing athletes.

PARTICIPANTS

Volleyball players competing in the Victorian State League, Australia.

ASSESSMENT OF RISK FACTORS

Patellar tendinopathy (PT) is common in sports involving running and jumping and can severely limit athletes' ability to compete. Several studies have investigated potential etiological factors for the development of PT, but little is known about the association between PT and foot posture.

MAIN OUTCOME MEASURES

Static foot posture index (FPI), patellar tendon pain during single-leg decline squatting, and gray scale ultrasound imaging were measured in 78 recreational to elite volleyball players (48 men and 30 women).

RESULTS

Men with patellar tendon pain were more likely to have a normal foot posture and men without pain were more likely to be pronated according to the FPI (P < 0.05). Women showed no association between FPI and pain or imaging (P > 0.05).

CONCLUSIONS

Men with a normal foot posture were more likely to have PT compared to men with a pronated foot type.

Surgical treatment of patellar tendinopathy in athletes. A retrospective multicentric study

The purpose of this study was to evaluate the results of surgery, in particular arthroscopic procedures in the treatment of patellar tendinopathies that are refractory to conservative treatment in athletes.

METHOD

A retrospective multicenter study was performed in four centers. Patients were athletes who did not respond to carefully followed conservative treatment and who underwent surgery. Sixty-four patients were included, 10 who underwent arthroscopy. Patients were questioned and followed-up for an average of 22 months (6-116 months).

RESULTS

At the final follow-up, 87% of the patients had an improved Blazina score and 63% were again practicing their sport at the same level. None of the preoperative factors influenced the final result and one surgical technique was not more effective than another (patellar tip resection versus arthroscopic approach).

DISCUSSION

The results of this study are comparable to those in the literature which show a success rate of more than 80% whatever the surgical technique. This study limits a certain number of biases because the patient group is homogenous (athletes, unsuccessful conservative treatment) with similar functional scores, and well-defined protocols for postoperative rehabilitation. However, the study of this entity is difficult because of the limited number of subjects and its different anatomopathological forms.

CONCLUSION

Surgical treatment is indicated in motivated athletes if carefully followed conservative treatment is unsuccessful after more than six months, making it impossible to practice a sport (Blazina grade 3). Arthroscopic techniques seem to be as effective as open surgery with an equivalent delay for beginning sports activities.

Platelet-rich plasma: from basic science to clinical applications

Platelet-rich plasma (PRP) has been utilized in surgery for 2 decades; there has been a recent interest in the use of PRP for the treatment of sports-related injuries. PRP contains growth factors and bioactive proteins that influence the healing of tendon, ligament, muscle, and bone. This article examines the basic science of PRP, and it describes the current clinical applications in sports medicine. This study reviews and evaluates the human studies that have been published in the orthopaedic surgery and sports medicine literature. The use of PRP in amateur and professional sports is reviewed, and the regulation of PRP by antidoping agencies is discussed.

Differential forces within the proximal patellar tendon as an explanation for the characteristic lesion of patellar tendinopathy: an in vivo descriptive experimental study

BACKGROUND

Patellar tendinopathy is a common condition affecting the posterior region of the proximal patellar tendon, but the reason for this typical location remains unclear.

HYPOTHESIS

The posterior region of the proximal patellar tendon is subjected to greater tendinous forces than is the corresponding anterior region.

STUDY DESIGN

Descriptive laboratory study.

METHOD

An optic fiber technique was used to detect forces in both the anterior and the posterior regions of the proximal patellar tendon in 7 healthy persons. The optic fiber force sensor works on the principle of the amplitude modulation of transmitted light when the optic fiber is geometrically altered owing to the forces acting on it. Longitudinal strain in the tendon or ligament produces a negative transverse strain, thus causing a force that effectively squeezes the optic fiber. Measurements were recorded during the following exercises: closed kinetic chain quadriceps contraction (eccentric and concentric), open kinetic chain quadriceps contraction (eccentric and concentric), a step exercise, and a jump exercise.

RESULTS

During all the exercises, the peak differential signal output in the posterior location of the proximal patellar tendon was greater than in the corresponding anterior location. The greatest differential signal output was found in the jump and squat exercises.

CONCLUSION

The posterior region of the proximal patellar tendon is subjected to greater tendinous forces than is the corresponding anterior region. This finding supports the tensile-overload theory of patellar tendinopathy.

CLINICAL RELEVANCE

Jump activities and deep squat exercises expose the patellar tendon to very large tendinous forces.

Arthroscopic resection of the lower patellar pole in patients with chronic patellar tendinosis

PURPOSE

The aim of this prospective study is to evaluate the clinical results of arthroscopic resection of the lower patellar pole in patients with patellar tendinosis.

METHODS

Twenty patients underwent an arthroscopic resection of the lower patellar pole between 2002 and 2004. All of them were evaluated at 6 weeks and 3, 6, 12, and 24 months after surgery using the Tegner activity level, the Lysholm score, the Kujala score, a modified jumper's knee classification according to Blazina, and visual analog scales for pain, function, and satisfaction. Clinical evaluation was performed 2 years after surgery. In addition, magnetic resonance imaging was performed preoperatively and at a 2-year follow-up.

RESULTS

By 6 weeks postoperatively and at every other follow-up visit, significant improvements were seen in the Lysholm score (P = .001), the Kujala score (P = .001) and the visual analog scales. The Tegner score improved significantly by 3 months postsurgery (P = .01). Two years after surgery, the Tegner score improved from 4.4 +/- 2.9 to 7.95 +/- 1.6 (P < .0001); the Lysholm score from 57.1 +/- 17.1 to 97.3 +/- 4.4 (P < .0001); and Kujala score from 53.7 +/- 14.7 to 95.4 +/- 7.8 (P < .0001). The jumper's knee classification showed excellent (stage 0) or good (stage I) results in 18 of 20 patients. At follow-up, all but one magnetic resonance image showed hypodens areals in the proximal aspect of the patellar tendon, and small osteophytes were seen in some cases at the resection area. These findings did not seem to have any influence on the results.

CONCLUSIONS

The arthroscopic resection of the lower patellar pole as a minimal invasive method to treat jumper's knee provides satisfactory clinical results in knee function and pain reduction with fast recovery and return to sport activities.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Extracorporeal shockwave for chronic patellar tendinopathy

BACKGROUND

Chronic patellar tendinopathy is an overuse syndrome with pathologic changes similar to tendinopathies of the shoulder, elbow, and heel. Extracorporeal shockwave was shown effective in many tendinopathies.

HYPOTHESIS

Extracorporeal shockwave therapy may be more effective than conservative treatment for chronic patellar tendinopathy.

STUDY DESIGN

Randomized controlled clinical trial; Level of evidence, 2.

METHODS

This study consisted of 27 patients (30 knees) in the study group and 23 patients (24 knees) in the control group. In the study group, patients were treated with 1500 impulses of extracorporeal shockwave at 14 KV (equivalent to 0.18 mJ/mm(2) energy flux density) to the affected knee at a single session. Patients in the control group were treated with conservative treatments including nonsteroidal anti-inflammatory drugs, physiotherapy, exercise program, and the use of a knee strap. The evaluation parameters included pain score, Victorian Institute of Sports Assessment score, and ultrasonographic examination at 1, 3, 6, and 12 months and then once a year.

RESULTS

At the 2- to 3-year follow-up, the overall results for the study group were 43% excellent, 47% good, 10% fair, and none poor. For the control group, the results were none excellent, 50% good, 25% fair, and 25% poor. The mean Victorian Institute of Sports Assessment scores were 42.57 +/- 10.22 and 39.25 +/- 10.85, respectively, before treatment (P = .129) and 92.0 +/- 10.17 and 41.04 +/- 10.96, respectively, after treatment (P < .001). Satisfactory results were observed in 90% of the study group versus 50% of the control group (P < .001). Recurrence of symptoms occurred in 13% of the study group and 50% of the control group (P = .014). Ultrasonographic examination showed a significant increase in the vascularity of the patellar tendon and a trend of reduction in the patellar tendon thickness after shockwave treatment compared with conservative treatments. However, no significant difference in the appearance, arrangement, and homogeneity of tendon fibers was noted between the 2 groups. There were no systemic or local complications or device-related problems.

CONCLUSION

Extracorporeal shockwave therapy appeared to be more effective and safer than traditional conservative treatments in the management of patients with chronic patellar tendinopathy.

Prediction of the success of nonoperative treatment of insertional Achilles tendinosis based on MRI

BACKGROUND

Insertional Achilles tendinosis is a common clinical diagnosis for posterior heel pain. Nonoperative treatments often are unsuccessful. The purpose of this paper was to review a series of patients with insertional tendinopathy to determine whether MRI stratification could predictably identify patients in whom nonoperative treatment would fail.

METHODS

Review of records identified 157 patients (176 tendons) who were treated for insertional posterior heel pain. All patients who required surgery had MRI and their tendinosis was classified based on tendon size and degree of involvement (type I, II, or III). Patients who required surgery had standard two-incision decompression and debridement.

RESULTS

Of the 157 patients (176 tendons) with insertional heel pain, 83 (53%) responded to nonoperative treatment (96 tendons). Most of these patients who had MRI evaluation had type I involvement. The remaining 74 patients (47%) required operative intervention after an average of 12 months of conservative treatment (80 tendons). Most of these tendons were types II and III. Overall, two of the 16 type I tendons (12.5%) required surgery, 59 of the 65 type II tendons (90.8%) needed surgery, and 19 (70.4%) of the 27 type III tendons required surgery.

CONCLUSIONS

Patients with tenderness of the Achilles tendon insertion without obvious signs of inflammation who demonstrate confluent areas of intrasubstance signal changes on MRI (types II and III) are not likely to respond to nonoperative treatment. Early identification of these patients and operative intervention may lead to earlier return to function.

Comparative accuracy of magnetic resonance imaging and ultrasonography in confirming clinically diagnosed patellar tendinopathy

BACKGROUND

Diagnosis of patellar tendinopathy is based primarily on clinical examination; however, it is commonplace to image the patellar tendon for diagnosis confirmation, with the imaging modalities of choice being magnetic resonance imaging (MRI) and ultrasonography (US). The comparative accuracy of these modalities has not been established.

HYPOTHESIS

Magnetic resonance imaging and US have good (>80%) accuracy and show substantial agreement in confirming clinically diagnosed patellar tendinopathy.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Magnetic resonance imaging and US (gray scale [GS-US] and color Doppler [CD-US]) features of 30 participants with clinically diagnosed patellar tendinopathy and 33 activity-matched, asymptomatic participants were prospectively compared. Accuracy, sensitivity, specificity, positive and negative predictive values, and the likelihood of positive and negative test results were determined for each technique.

RESULTS

The accuracy of MRI, GS-US, and CD-US was 70%, 83%, and 83%, respectively (P = .04; MRI vs GS-US). The likelihood of positive MRI, GS-US, and CD-US was 3.1, 4.8, and 11.6, respectively. The MRI and GS-US had equivalent specificity (82% vs 82%; P = 1.00); however, the sensitivity of GS-US was greater than MRI (87% vs 57%; P = .01). Sensitivity (70% vs 87%; P = .06) and specificity (94% vs 82%; P = .10) did not differ between CD-US and GS-US.

CONCLUSIONS

Ultrasonography was more accurate than MRI in confirming clinically diagnosed patellar tendinopathy. GS-US and CD-US may represent the best combination for confirming clinically diagnosed patellar tendinopathy because GS-US had the greatest sensitivity, while a positive CD-US test result indicated a strong likelihood an individual was symptomatic.

Surgical treatment of chronic patellar tendinosis: a systematic review

There is no consensus in the literature on the best surgical procedure for patellar tendinosis when nonoperative treatment fails. With a systematic review, we asked whether surgical treatment of the inferior pole of the patella, closing of the paratenon, or immobilization affected the percentage of patients reporting good to excellent results (percent success). We completed a systematic review of surgical treatment for patellar tendinosis. A literature search of Medline, CINAHL, and Sport Discus revealed 30 articles on treatment of patellar tendinosis. Ten met our initial inclusion criteria. Most studies were retrospective and used varying techniques. Outcome measures were individual to the specific article, making it difficult to compare the results of the studies. Studies that described surgical treatment of the inferior pole of the patella had 70.9% success compared to 91.7% for those that performed no patella bony work. Closure of the paratenon was reported in seven studies with 84.8% success compared to 91.5% for the other studies. Immobilization was used in four studies with 82.4% success compared to 94.9% success for four studies that did not immobilize postoperatively. Care must be taken when comparing these weighted averages since only two of the nine studies described exactly the same technique. Ideally, prospective controlled studies with validated assessment tools and activity scores are required to determine the best treatment for our patients.

The evolution of eccentric training as treatment for patellar tendinopathy (jumper's knee): a critical review of exercise programmes

BACKGROUND AND AIM

Eccentric training has become a popular treatment for patellar tendinopathy. Our purpose was to review the evolution of eccentric strength training programmes for patellar tendinopathy with a focus on the exercise prescriptions used, to help clinicians make appropriate choices and identify areas needing further research.

METHODS

A computerised search of the entire MEDLINE database was performed on 1 September 2006 to identify prospective and randomised clinical trials with a focus on clinical outcome of eccentric training for patellar tendinopathy.

RESULTS

7 articles with a total of 162 patients and in which eccentric training was one of the interventions, all published after 2000, were included. The results were positive, but study quality was variable, with small numbers or short follow-up periods. The content of the different training programmes varied, but most were home-based programmes with twice daily training for 12 weeks. A number of potentially significant differences were identified in the eccentric programmes used: drop squats or slow eccentric movement, squatting on a decline board or level ground, exercising into tendon pain or short of pain, loading the eccentric phase only or both phases, and progressing with speed then loading or simply loading.

CONCLUSION

Most studies suggest that eccentric training may have a positive effect, but our ability to recommend a specific protocol is limited. The studies available indicate that the treatment programme should include a decline board and should be performed with some level of discomfort, and that athletes should be removed from sports activity. However, these aspects need further study.

Animal models for the study of tendinopathy

Tendinopathy is a common and significant clinical problem characterised by activity-related pain, focal tendon tenderness and intratendinous imaging changes. Recent histopathological studies have indicated the underlying pathology to be one of tendinosis (degeneration) as opposed to tendinitis (inflammation). Relatively little is known about tendinosis and its pathogenesis. Contributing to this is an absence of validated animal models of the pathology. Animal models of tendinosis represent potential efficient and effective means of furthering our understanding of human tendinopathy and its underlying pathology. By selecting an appropriate species and introducing known risk factors for tendinopathy in humans, it is possible to develop tendon changes in animal models that are consistent with the human condition. This paper overviews the role of animal models in tendinopathy research by discussing the benefits and development of animal models of tendinosis, highlighting potential outcome measures that may be used in animal tendon research, and reviewing current animal models of tendinosis. It is hoped that with further development of animal models of tendinosis, new strategies for the prevention and treatment of tendinopathy in humans will be generated.

Anthropometric risk factors for patellar tendon injury among volleyball players

OBJECTIVE

Abnormal imaging in the patellar tendon reveals pathology that is often associated with knee pain. Anthropometric measures of body size and mass, such as height, weight and waist-to-hip ratio (WHR), have been individually associated with abnormal imaging. The aim of this study was to investigate the anthropometric factors that have the strongest relationship with abnormal imaging in volleyball players.

METHODS

Height, weight, body mass index (BMI), waist girth, hip girth and WHR were measured in a cohort of 113 competitive volleyball players (73 men, 40 women). The univariate (ANOVA) and multivariable (discriminant function analysis) association between abnormal imaging and these anthropometric factors were investigated.

RESULTS

No significant association was found in the female volleyball players. A significant univariate association was observed between abnormal imaging and heavier weight, greater BMI, larger waist and hip girth and larger WHR in the male volleyball players. Waist girth was the only factor that retained this association in a multivariable model (p<0.05).

CONCLUSIONS

Men with a waist girth greater than 83 cm seem to be at greater risk of developing patellar tendon pathology. There may be both mechanical and biochemical reasons for this increased risk.

Imaging the infrapatellar tendon in the elite athlete

Extensor mechanism injuries constitute a major cause of anterior knee pain in the elite athlete. Sonography and magnetic resonance imaging (MRI) are the imaging methods of choice when assessing the infrapatellar tendon. A comprehensive imaging review of infrapatellar tendon normal anatomy, tendinopathy, and partial/full-thickness tendon tears is provided. The value of imaging the infrapatellar tendon in clinical practice, including whether sonography can predict symptoms in asymptomatic athletes, is discussed. Acute avulsion fractures, including periosteal sleeve avulsion, and chronic avulsion injuries, including Sinding-Larsen-Johansson and Osgood-Schlatter syndromes, are shown. Mimics of infrapatellar tendon pathology, including infrapatellar plica injury, patellar tendon-lateral femoral condyle friction syndrome, and Hoffa's syndrome, are illustrated.

Recalcitrant patellar tendinosis in elite athletes: surgical treatment in conjunction with aggressive postoperative rehabilitation

BACKGROUND

Recalcitrant patellar tendinosis is difficult to treat, and results are varied.

HYPOTHESIS

Surgical removal of necrotic tissue, surgical stimulation of remaining tendon, and aggressive and specific rehabilitation after patellar tendonectomy will allow athletes to return to sports.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From December 1996 to July 2002, 16 high-level athletes (4 professional, 2 Olympic, 9 collegiate, 1 preparatory), aged 16 to 25 years (mean, 19.7 years), with 22 symptomatic patellar tendons had failed nonoperative care of their patellar tendinosis symptoms and were unable to compete effectively in their sports. Magnetic resonance imaging showed confirmation of disease, with typical findings being necrosis in the posterior half of an abnormally thick patellar tendon, often in conjunction with partial tearing of the posterior half with a compensatory enlargement of the anterior half. Each patient then underwent tendonectomy of the necrotic portion in conjunction with stimulation of the remaining tendon by making multiple longitudinal cuts in the tendon. Patients participated in a postoperative rehabilitation protocol that included immediate range of motion, full flexion, and immediate high-repetition, low-resistance quadriceps muscle exercise.

RESULTS

Subjective improvement was noted in all athletes. Return to the same sport at prior level of intensity was accomplished by 14 of 16 patients (87.5%) at a mean of 8.1 months (range, 3-12 months).

CONCLUSION

Overall, tendonectomy, surgical tendon stimulation, and aggressive postoperative rehabilitation were found to be a safe, effective way to return high-level athletes to their sports.

Anterior knee pain: diagnosis and treatment

Anterior knee pain is a frequent clinical problem. It provides a common challenge to diagnose and manage. Basic science studies have provided insight into the origin of anterior knee pain and refined understanding of the anatomy. Clinical evaluation has progressively focused on the contribution of the entire lower extremity to patellofemoral function. Nonsurgical management has been refined by the concept of the "envelope of function" and by increased understanding of the neuromuscular control of the knee. Indications for lateral release have been clarified and narrowed. Although anteromedial transfer of the tibial tuberosity is helpful in certain circumstances, reports of postoperative fracture have led to less aggressive rehabilitation protocols. Chondral resurfacing of the patellofemoral joint and patellofemoral arthroplasty are evolving. Emphasis should remain on nonsurgical management, which is sufficient in most patients.

Etiology of Patellar Tendinopathy in Athletes

Objective:

To review the etiology of patellar tendinopathy as it relates to clinical management of chronic patellar-tendon disease in athletes.

Data Sources:

Information was gathered from a MEDLINE search of literature in English using the key wordspatellar tendinitis, patellar tendonitis, patellar tendinosis, patellar tendinopathy,andjumper’s knee.

Study Selection:

All relevant peer-reviewed literature in English was reviewed.

Data Synthesis:

The etiology of patellar tendinopathy is multifactorial, incorporating both intrinsic and extrinsic factors. Age, muscle flexibility, training program, and knee-joint dynamics have all been associated with patellar tendinopathy. The roles of gender, body morphology, and patellar mobility in patellar tendinopathy are unclear.

Conclusions:

The pathoetiology of patellar tendinopathy is a complex process that results from both an inflammatory response and degenerative changes. There is a tremendous need for research to improve our understanding of the pathoetiology of patellar tendinopathy and its clinical management.

Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations

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

Patellar tendinosis as an adaptive process: a new hypothesis

BACKGROUND

Patellar tendinosis (PT), or "jumper's knee" is a common condition in athletes participating in jumping sports, and is characterised by proximal patellar tendon pain and focal tenderness to palpation. Hypoechoic lesions observed in the proximal patellar tendon associated with the tendinosis are typically described as being a result of degenerative change or "failed healing". We propose a new model for the development of the hypoechoic lesion observed in PT, in which the aetiology is an adaptive response to differential forces within the tendon.

METHODS

We assessed the clinical, histopathological, and biomechanical literature surrounding the patellar tendon and integrated this with research into the response of tendons to differential forces.

RESULTS AND CONCLUSIONS

We propose that the hypoechoic lesion commonly described in PT is the result of adaptation or partial adaptation of the proximal patellar tendon to a compressive load. We postulate that the biomechanics of the patellar-patellar tendon interface creates this compressive environment. Secondary failure of the surrounding tensile adapted tendon tissue may result in tissue overload and failure, with resultant stimulation of nociceptors. We believe that this "adaptive model" of patellar tendinosis is consistent with the clinical and histological findings.

Flexor carpi ulnaris tendinopathy

PURPOSE

This study describes the pathology of flexor carpi ulnaris (FCU) tendinopathy and its treatment.

METHODS

Five patients (1 bilateral) who failed nonsurgical management of FCU tendinopathy had FCU tendon debridement. The excised tendon was examined histologically and 4 patients (1 bilateral) were followed-up for at least 12 months.

RESULTS

The pathology was degenerative tendinosis (angiofibroblastic hyperplasia) in all specimens, identical to that observed in tennis elbow and the rotator cuff. Surgical excision of the pathologic degeneration gave excellent pain relief in all cases.

CONCLUSIONS

The pathology of FCU tendinopathy (ie, degenerative tendinosis) is similar to that of other extrasynovial tendons. Surgical debridement of the pathologic tendinosis tissue is effective treatment for patients who fail nonsurgical management.

Tratamento cirúrgico da tendinite distal da patela

A tendinite distal da patela é uma doença que acomete principalmente jovens esportistas e caracteriza-se por dor referida na extremidade distal da patela junto à inserção do ligamento patelar. O tratamento inicial preconizado é sempre conservador com fisioterapia. A grande maioria tem boa resposta a este tipo de conduta, mas em alguns raros casos os sintomas não regridem exigindo uma mudança de conduta. Para este grupo usamos o tratamento cirúrgico com técnica derivada de Trillat que se baseia na utilização de um enxerto de parte do tendão do músculo Grácil implantado dentro do ligamento patelar, inserido intra-ósseo na patela e fixado na tuberosidade anterior da tíbia. Foram operados seis pacientes, sendo que em dois casos a operação foi bilateral, totalizando oito joelhos. O seguimento mínimo foi de três anos, com avaliação final dentro do índice considerado como EXCELENTE, conforme a cotação ARPÉGE, para todos os joelhos.

Patellar tendonitis and patellar dislocations

Common sports injuries, such as patellar tendonitis and patellar dislocation, can be treated either surgically or with rehabilitation and physical therapy. Most patients with patellar tendonitis will respond well to conservative measures; however, some recalcitrant cases will require surgical intervention. To date, the literature is not able objectively to identify the patients best suited to surgery. Likewise, in the case of patellar dislocations, it is still unclear which patients respond best to conservative therapy and which respond best to surgical treatment, although evidence continues to accumulate. A practical approach to this problem can be deduced from the available evidence, but more well-designed clinical trials are needed for the establishment of definitive treatment protocols.

Thermal microdebridement does not affect the time zero biomechanical properties of human patellar tendons

BACKGROUND

Thermal microdebridement for the treatment of chronic tendinopathy has recently been introduced. The effect of thermal microdebridement on the biomechanical properties of human tendons, however, remains unknown.

HYPOTHESIS

Thermal microdebridement does not affect the biomechanical properties of human patellar tendons in a cadaveric model at the time of initial treatment.

STUDY DESIGN

Controlled laboratory study.

METHODS

The central 15 mm of 12 matched, human (mean age, 71 years; 8 male, 4 female), fresh-frozen patellar tendons was divided into 3 equal 5-mm specimens. The treatment group (n = 12) underwent thermal microdebridement with a radiofrequency probe. A sham treatment group (n = 12) underwent insertion of a deactivated probe. The control group (n = 12) underwent no treatment. After treatment, each specimen was tested to failure in a servo-hydraulic materials testing machine at an elongation rate of 3 mm/s. One-way repeated measures analysis of variance was used to determine differences between groups.

RESULTS

No significant difference in ultimate stress at failure, elastic modulus, strain energy density, or strain at maximum load was found between the groups. The ultimate stress at failure for the treatment, sham, and control groups was 61.0, 66.7, and 63.0 MPa, respectively (P = .653), and the strain at maximum load was 0.12, 0.11, and 0.09, respectively (P = .279).

CONCLUSIONS

Thermal microdebridement does not affect the biomechanical properties of cadaveric human patellar tendons at the time of initial treatment.

CLINICAL RELEVANCE

It may be safe to proceed with aggressive rehabilitation after thermal microdebridement of the patellar tendon. However, the results in this cadaveric model should be interpreted with caution. Additional studies using an in vivo model will be required to completely assess the effects of thermal microdebridement on the biomechanical properties of human patellar tendons.

Role of extracellular matrix in adaptation of tendon and skeletal muscle to mechanical loading

The extracellular matrix (ECM), and especially the connective tissue with its collagen, links tissues of the body together and plays an important role in the force transmission and tissue structure maintenance especially in tendons, ligaments, bone, and muscle. The ECM turnover is influenced by physical activity, and both collagen synthesis and degrading metalloprotease enzymes increase with mechanical loading. Both transcription and posttranslational modifications, as well as local and systemic release of growth factors, are enhanced following exercise. For tendons, metabolic activity, circulatory responses, and collagen turnover are demonstrated to be more pronounced in humans than hitherto thought. Conversely, inactivity markedly decreases collagen turnover in both tendon and muscle. Chronic loading in the form of physical training leads both to increased collagen turnover as well as, dependent on the type of collagen in question, some degree of net collagen synthesis. These changes will modify the mechanical properties and the viscoelastic characteristics of the tissue, decrease its stress, and likely make it more load resistant. Cross-linking in connective tissue involves an intimate, enzymatical interplay between collagen synthesis and ECM proteoglycan components during growth and maturation and influences the collagen-derived functional properties of the tissue. With aging, glycation contributes to additional cross-linking which modifies tissue stiffness. Physiological signaling pathways from mechanical loading to changes in ECM most likely involve feedback signaling that results in rapid alterations in the mechanical properties of the ECM. In developing skeletal muscle, an important interplay between muscle cells and the ECM is present, and some evidence from adult human muscle suggests common signaling pathways to stimulate contractile and ECM components. Unaccostumed overloading responses suggest an important role of ECM in the adaptation of myofibrillar structures in adult muscle. Development of overuse injury in tendons involve morphological and biochemical changes including altered collagen typing and fibril size, hypervascularization zones, accumulation of nociceptive substances, and impaired collagen degradation activity. Counteracting these phenomena requires adjusted loading rather than absence of loading in the form of immobilization. Full understanding of these physiological processes will provide the physiological basis for understanding of tissue overloading and injury seen in both tendons and muscle with repetitive work and leisure time physical activity.

Patellar tendinopathy

Patellar tendinopathy is a common and serious condition in athletes. Although there have been many advances in the understanding of the histopathology, imaging, and surgical outcomes in this condition in the past decade, successful management of athletes with patellar tendinopathy remains a major challenge for both the practitioner and patient. There is a definite need for further prospective studies into etiological factors and randomized controlled trials into treatment choices.