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Patellar tendinopathy

79 citationsUpdated Sep 2026

Overview

Patellar tendinopathy, commonly known as jumper’s knee, is a condition affecting active individuals who engage in activities involving forceful, eccentric contraction of the knee extensor mechanism, particularly jumping sports [16]. It occurs most frequently in adolescents and young adults [16], though persistent cases are associated with worsening knee pain in community-based middle-aged women [1]. Risk factors include harder playing surfaces and increased practice frequency [16]. Pathoanatomically, the condition tends to occur at the deep fibers of the patellar attachment, which have a tenuous blood supply [16]. Affected tissue may demonstrate fibrinoid necrosis, angiofibroblastic change, mucoid degeneration, disorganized collagen structure, or metaplasia of adjacent fibrocartilage [16]. The medial portion of the tendon often demonstrates thickening [16], and patients may present with patella alta, suggesting a recalcitrant subgroup that may benefit from biomechanical surgical solutions [11].

Clinical presentation involves an insidious onset of pain and swelling, initially after activity, progressing to pain during and after activity, and eventually limiting athletic performance [16]. Patients may report knee buckling due to reflex quadriceps inhibition [16]. Physical examination reveals tenderness and soft-tissue swelling at the tendon-bone attachment, with discomfort during resisted knee extension [16]. Imaging typically shows tendon thickening on MRI, which is more diagnostic than signal changes, and may reveal degenerative spurring on plain radiographs [16]. The Blazina classification stages the condition from pain after activity (Stage 1) to pain during and after activity (Stage 2), and finally to pain limiting function during activity (Stage 3) [16].

Nonsurgical intervention is the mainstay of treatment, consisting of activity modification, progressive flexibility and eccentric strengthening exercises, taping or infrapatellar straps, and NSAIDs [16]. Corticosteroid injection is contraindicated due to the increased risk of tendon rupture [16]. While ultrasound can likely be excluded as a treatment [17], biologic and less-invasive ultrasound-based treatments show promise [9]. Platelet-rich plasma injections may offer clinical benefit for chronic cases, particularly when rehabilitative approaches have failed, though evidence quality is generally poor and results should be interpreted with caution [35, 36]. Surgical treatment is reserved for patients with persistent pain and swelling after nonsurgical attempts [16]. Surgery leads to substantial improvements in functional outcomes [2], notable improvement in patient-reported outcomes with high return-to-play rates [6], and significant improvements in symptoms and function that are maintained for at least three years [8]. Advanced patellar tendinopathy is associated with increased rates of bone-patellar tendon-bone autograft failure in anterior cruciate ligament reconstructions, necessitating consideration of the condition when determining optimal graft choice [34, 68].

Anatomy & Pathophysiology

Etiology and Risk Factors

Patellar tendinopathy arises from repetitive, forceful, and eccentric contraction of the extensor mechanism [37]. The condition affects up to 20% of jumping athletes [37] and is prevalent in sports demanding high speed and power from leg extensors [128]. It occurs most frequently in adolescents and young adults [16], with males more commonly affected than females [37]. Increased rates are associated with harder playing surfaces and higher practice frequency [16]. Risk factors include poor quadriceps and hamstring flexibility [37]. Extrinsic factors, particularly mechanical overload of the extensor apparatus, and intrinsic factors such as malalignment, patella alta, abnormal patellar laxity, muscular tightness, and imbalance have been proposed as causes [12]. Altered movement patterns may perpetuate symptoms [14]. While intratendinous alterations are associated with the disease, specific predictive factors have not been identified [19]. A greater incidence of patella alta, defined by sagittal patellar flexion angle, suggests a recalcitrant subgroup that may not improve with current surgical intervention [11]. The jumper’s knee group exhibits a longer lower patellar pole and an increased ratio between articular and non-articular patellar surface [118].

Histopathology and Tissue Changes

The key pathophysiologic phenomenon is tendinosis, a degenerative process characterized by progressive tissue degeneration, an inability to repair, and the absence of inflammatory cells [12]. Histologic evaluation confirms degeneration rather than inflammation [37]. Macroscopically, the affected region appears yellow, described as “mucoid degeneration” [12]. Histologically, the tissue displays a lack of neutrophils and macrophages, disorganized collagen, increased vascularity, and fatty, mucoid, or hyaline changes [45]. The area has a tenuous blood supply [16], and the medial portion often demonstrates thickening compared with the rest of the tendon [16]. Increased neovascularization accompanies the lack of reparative capacity and is directly related to pain [12]. Inflammatory mediators, particularly cyclooxygenase-2, are linked to pain in the absence of inflammatory cells [12]. Fibril morphology is abnormal, but tendon mechanical properties remain unchanged [129]. Approximately two-thirds of patients with jumper's knee exhibit structural tendon changes with neovascularization [82]. Partial-thickness tears are located posterior or posteromedially in the proximal patellar tendon [74]. Tendon thickness greater than 8.8 mm strongly correlates with the presence of a partial-thickness tear [74].

Imaging Findings

MRI usually shows thickening in the affected portion of the patellar tendon and may demonstrate intrasubstance signal abnormalities, though thickening is more diagnostic than signal changes [16]. MRI can show increased signal intensity on both T1 and T2 images and loss of the posterior border of the fat pad in chronic cases [37]. Signal intensity changes are mostly located in the posterior part of the proximal patellar tendon and corresponding parts of the Hoffa fat pad, closely related to the lower patellar pole [118]. Plain radiographs may demonstrate degenerative spurring where the tendon attaches to bone [16]. Ultrasonography shows tendon thickening and hypoechoic areas [37]. Tendon abnormality without pain affects 13.5% of volleyball players’ patellar tendons [118]. Normal tendons are more likely to develop tendon abnormality without pain (10–18%) than with pain (2–7%) [118]. Although approximately 70% of tendons with structural changes at baseline were normal at follow-up, no clear relationship between structure and function was found in young elite volleyball players [131]. Clinical symptoms may persist years after loading-based treatment, whereas some but not all tendon structures normalize in longer-term follow-up [3]. Persistent patellar tendinopathy is associated with worsening knee pain [1], and jumper's knee causes mild but long-lasting symptoms after an athletic career [81].

Biomechanics and Pathogenesis

The posterior region of the proximal patellar tendon is subjected to greater tendinous forces than the corresponding anterior region [79]. Patellar tendon strain increases at the site of the jumper's knee lesion during knee flexion and tendon loading [119]. Ultrasound examination of strained cadaveric complexes revealed obvious disruption of fascicular architecture immediately adjacent to the inferior pole of the patella in 3 of 5 specimens [119]. This disruption occurred at the precise location of highest principal strain predicted by the model for the 145° patella–patellar tendon angle [119]. Matrix-mediated changes, where repetitive heavy loading leads to microtrauma and failed healing, are thought to predominate in pathogenesis [45]. Cellular-triggered pathologic changes have also been proposed, with stress-activated protein kinases identified [45]. Increased apoptosis in patellar tendinosis supports cell-mediated pathologic changes [45]. The exact pathogenesis remains unknown [45]. Further study is needed on the biomechanical implications of the pivot point and how altering it affects stress within the patellar tendon, patellofemoral joint, and associated clinical outcomes [108]. Clinicians should clinically separate patellar tendinopathy and quadriceps tendinopathy to design specific rehabilitation programs, as the two entities have distinct anatomical, biomechanical, and epidemiological characteristics [25].

Vascular Supply and Mechanical Load

The patellar tendon receives its blood supply from the infrapatellar fat pad and from the retinaculum through the medial and lateral inferior geniculate arteries [71]. The tendon routinely sees forces of 3 times body weight when ascending stairs, and it takes over 17 times body weight to rupture a normal tendon [71]. Bilateral changes in tendon structure are present in patients diagnosed with unilateral patellar tendinopathy, highlighting that the asymptomatic side should not be used as a reference in clinical practice [83].

Classification

Blazina: The Blazina classification defines the severity of patellar tendinopathy across three to four stages, with variations in nomenclature and specific criteria among cited sources. One description outlines three stages: Stage 1 involves pain after activity, Stage 2 involves pain during and after activity, and Stage 3 involves pain that limits function during an activity [16]. An alternative three-phase model defines Phase I as pain after activity only, Phase II as pain during and after activity, and Phase III as persistent pain with and without activity along with deterioration of performance [37]. Blazina et al. described a four-phase classification: Phase I is pain only after activity; Phase II is pain or discomfort during activity that does not interfere with sports participation; Phase III is pain both during and after participation that interferes with competition; and Phase IV is complete tendon disruption [111].

Other Considerations: In a study of volleyball players, the severity of symptoms for current patellar tendinopathy was classified as grade I in 6 knees, grade II in 18 knees, and grade IIIa in 9 knees [40]. Diagnostic criteria for jumper’s knee in a surgical trial included a clinical diagnosis of grade-IIIB symptoms on the Blazina scale, defined as pain during and after activity and an inability to participate in sports at the same level as before the onset of pain [54]. Similarly, diagnostic criteria for patellar tendinopathy in a neuromediator study required a clinical diagnosis of jumper’s knee grade IIIB, defined as pain during and after activity and an inability to participate in sports at the same level as before pain [59].

Clinical Presentation

Epidemiology and Risk Factors

Patellar tendinopathy affects active individuals who perform activities requiring forceful, eccentric contraction of the knee extensor mechanism, particularly jumping sports [16]. Chronic overload is a major causative factor [18]. Poor quadriceps and hamstring flexibility serve as risk factors [37]. In elite volleyball players, the condition is prevalent, with 51.0% of 47 players diagnosed via clinical examination [40]. The mean age at symptom onset in this cohort was 18.8 ± 2.8 years, with a mean symptom duration of 3.5 ± 2.4 years [40]. In elite soccer, patellar tendinopathy is fairly common but mainly mild in nature, though the recurrence rate is high [42]. MRI-defined patellar tendinopathy is common in community-based adults and is associated with a current or past history of obesity assessed by BMI or body weight, but not fat mass [21].

Symptoms and History

Patients typically describe an insidious onset of pain and swelling of the affected tendon [16]. Presentation often involves anterior knee pain at the inferior border of the patella [37]. In chronic cases, pain may be present at rest with prolonged sitting [37]. Among elite volleyball players, symptom onset was gradual in 94% of knees and acute in 2 knees [40].

Physical Examination

Clinical examination features indicative of patellar tendinopathy include tenderness to palpation at the inferior pole of the patella with the knee fully extended and the quadriceps relaxed [85]. The condition is characterized by tenderness on palpation and load-dependent pain at the inferior pole of the patella [62]. Palpation is painful at the insertion of the patellar tendon to the inferior pole of the patella [37]. A Bassett sign is defined as tenderness to palpation at the distal pole of the patella in full extension, but no tenderness to palpation at the distal pole of the patella in full flexion [37].

Imaging

Plain radiographs are often normal but may show inferior traction spurs or enthesophyte in chronic cases [37]. On MRI, thickening is much more diagnostic than signal changes when identifying abnormal tendon [16]. MRI may be useful to identify partial tears and chronic tears and may be used for surgical planning [37]. In chronic cases, MRI can show increased signal intensity on both T1 and T2 images and loss of the posterior border of the fat pad [37]. Ultrasonography will show thickening of the tendon and hypoechoic areas [37]. Ultrasonography was more accurate than MRI in confirming clinically diagnosed patellar tendinopathy [63]. Preseason ultrasound screening can identify symptomatic patellar tendinopathy and associated sequelae during the season [66]. Preseason anteroposterior tendon thickness serves as a more stable and precise measure of severity compared to VISA-P scores [66].

Classification

The Blazina classification defines severity stages based on pain and functional limitation: Stage 1: Pain after activity [16]. Stage 2: Pain during and after activity [16]. Stage 3: Pain that limits function during an activity [16]. Phase III: Persistent pain with and without activity along with deterioration of performance [37].

Investigations

MRI: 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 [21]. Bilateral changes in tendon structure are present in patients diagnosed with unilateral insertional or midportion Achilles tendinopathy or patellar tendinopathy [83]. Consequently, the asymptomatic side should not be used as reference in clinical practice for tendon structure monitoring [83].

Partial-thickness tears are located posterior or posteromedially in the proximal patellar tendon [74]. Tendon thickness greater than 8.8 mm is strongly correlated with the presence of a partial-thickness tear [74]. The use of bone-patellar tendon-bone (BPTB) autograft is not recommended if patellar tendinopathy is obvious or there is suspicion of a partial tendon tear on MRI [49]. Conversely, patients with evidence of mild-to-moderate patellar tendinopathy on MRI before undergoing ACL reconstruction with BPTB autograft have no notable differences in ACL retear rates and rates of subsequent ipsilateral knee surgery [48].

Long-term follow-up indicates that clinical symptoms remained even years after loading-based treatment for patellar tendinopathy, whereas some but not all tendon structures normalized in this longer term follow-up [3]. In contrast, PRP treatment permitted a return to a normal architecture of the tendon as assessed by MRI [130].

Ultrasound: Preseason anteroposterior (AP) thickness serves as a more stable and precise measure of severity compared to VISA-P scores [66]. Increased preseason patellar tendon thickness is associated with an increased risk of symptomatic patellar tendinopathy and associated sequelae in male NCAA Division I basketball players [132].

Other Considerations: A greater patella alta incidence amongst patellar tendinopathy patients as defined by sagittal patellar flexion angle (SPFA) was found to be clinically relevant [11]. Patients with greater patella alta incidence may comprise the recalcitrant patient subgroup who do not improve with current surgical intervention and may benefit from a biomechanical surgical solution [11]. Altered movement patterns during a drop jump may be perpetuating symptoms associated with patellar tendinopathy [14].

Treatment

Non-Operative

Initial nonsurgical management centers on activity modification [16]. Adjunctive measures include taping to aid proprioception and patellar tracking, or the use of an infrapatellar strap, both of which can be helpful in nonsurgical management [16]. Male gender and having fewer symptoms are possible predictors of effectiveness in patients treated with a patellar strap [28]. NSAIDs can be beneficial in the nonsurgical treatment of patellar tendinopathy [16], although treatment with corticosteroid injections and oral NSAIDs showed positive short-term effects only [37]. Corticosteroid injection is contraindicated for patellar tendinopathy because of the increased risk of tendon rupture [16]. There is no evidence to support Kinesio taping, acupuncture, fascial therapy, or cryotherapy for patellar tendinopathy [37].

Extracorporeal shockwave therapy (ESWT) appears more effective and safer than traditional conservative treatments for chronic patellar tendinopathy [64] and is an effective intervention that should be considered, particularly when other nonoperative treatments have failed [114]. However, ESWT as a solitary treatment during the competitive season offers no benefit over placebo in actively competing jumping athletes with symptoms for less than 12 months [65]. Sclerosing injections with polidocanol result in significant improvement in knee function and reduced pain [109], and targeting neovessels in patellar tendinosis has the potential to cure tendon pain and allow return to full patellar-tendon loading activity [112].

Platelet-rich plasma (PRP) is a safe and promising therapy for recalcitrant patellar tendinopathy [106], and patellar tendons seem to benefit from PRP injections [116]. PRP injections offer a clinical benefit and may be considered a suitable option for chronic patellar tendinopathy, particularly for complex cases or when nonsurgical rehabilitative approaches have failed, although the evidence is not definitive due to the generally poor quality of current literature [35]. The results of systematic reviews and meta-analyses of PRP should be interpreted with caution due to concerns regarding literature search, quality control, and publication bias, concluding that further research is needed to determine if PRP is a suitable nonsurgical alternative [36]. Treatment with BM-MSC or Lp-PRP in combination with rehabilitation is effective in reducing pain and improving activity levels in active participants with chronic patellar tendinopathy [110]. No recommendation can be made currently regarding prolotherapy injections using a local irritant to elicit an inflammatory healing response [16], nor regarding platelet-rich plasma injection [16]. Although a small, immediate clinical response to IGF-1 injections was seen when combined with training, no additional long-term effect of intratendinous IGF-1 was observed on structural and clinical outcomes [30].

Regarding exercise therapy, there was no superior effect of exercising with a high load magnitude compared with a moderate load magnitude for the clinical outcome, tendon structure, or tendon function in the short term [32]. Physical test results including strength and flexibility in the lower limb, jump performance, and pain levels during pain-provoking tests were not identified as prognostic factors for patient-reported outcomes after exercise therapy [29]. In the group treated nonoperatively, results were better in patients who had stage 2 tendinopathy than in those with stage 3 [70].

Operative

Indications: Operative treatment is indicated for patellar tendinopathy refractory to nonoperative management [8, 26]. It seems to give good results in most cases of distal patellar tendinosis in athletes when conservative treatment has failed [22]. Treatment for patellar tendinopathy continues to evolve, with biologic and less-invasive ultrasound-based treatments showing promise, and surgical intervention providing reliable outcomes [9].

Surgical Approach / Technique: Débridement can be achieved by simple longitudinal excision of the diseased portion of tendon, followed by abrasion of the bone to provide a bleeding surface for tendon healing, and finishing with the application of side-to-side sutures or suture anchors as needed [16]. Variations of the débridement procedure include drilling of the bone to stimulate a healing response or multiple tendon perforations (“pie crusting”) to stimulate healing of the tendon tissue [16]. Arthroscopic surgery for patients with patellar tendinopathy refractory to nonoperative management appears to provide significant improvements in symptoms and function, with improvements maintained for at least 3 years [8]. Arthroscopic treatment can relieve the pain of refractory chronic patellar tendinopathy [26]. Patellar tendon reconstruction in addition to debridement in the setting of significant partial patellar tendon tearing provides the patients with improved functional outcomes and decreases the risk for potential complications [5]. There is no consensus in the literature on the best surgical procedure for patellar tendinosis when nonoperative treatment fails [122].

Other Considerations: 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 [122]. Closure of the paratenon was reported in seven studies with 84.8% success compared to 91.5% for the other studies [122]. Immobilization was used in four studies with 82.4% success compared to 94.9% success for four studies that did not immobilize postoperatively [122].

Postoperative Rehabilitation: The knee immobilizer is worn for 3 to 4 weeks after tenotomy and repair for chronic patellar tendinosis, and crutches are used for partial weight bearing [115]. Postoperative rehabilitation for patellar tendinopathy surgery includes immobilization in extension, followed by progressive range of motion and strengthening [37]. Stage 1 of rehabilitation after tenotomy and repair should emphasize range of motion and isometric strengthening [115]. Closed-chain kinetics are started in stage 2 of rehabilitation when swelling and tenderness have resolved [115]. Stage 3 of rehabilitation should consist of activity-specific exercises, avoiding eccentric overload [115]. Return to full activities can be allowed when 85% to 90% of strength and full range of motion are achieved [115]. Return to activities is achieved by 80% to 90% of athletes after patellar tendinopathy surgery [37]. There may be activity-related aching for 4 to 6 months after patellar tendinopathy surgery [37].

Complications

Patellar / Extensor-mechanism: Repair of chronic patellar tendon rupture is complicated by proximal retraction of the patella and insufficient tissue for repair [27]. Chronic quadriceps tendon ruptures present with proximal migration of the tendon stump, necessitating débridement and mobilization of the tendon [27]. Quadriceps tendon ruptures carry a more guarded prognosis due to the incomplete nature of the injury and persistent degenerative tissue, with outcomes adversely affected by chondromalacia or patella alta [76]. In the setting of significant partial patellar tendon tearing, patellar tendon reconstruction in addition to debridement decreases the risk for potential complications [5].

Surgical Outcomes and Revision: Open surgery involving excision of scarred tissue, separation of the patellar tendon from Hoffa body, multiple longitudinal tenotomies, and excision of abnormal areas from failed surgery for patellar tendinopathy results in clinically relevant improvement in symptoms, VISA-P scores, and levels of activities at 30-month follow-up [125]. In a cohort of athletes undergoing revision surgery for failed patellar tendinopathy treatment, 68.2% returned to competition within a year [125]. Male athletes returned to training slightly faster than female athletes following this revision surgery (9.0 vs 10.0 months) [125]. Surgical reconstruction of chronic patellar tendon ruptures using contralateral bone-tendon-bone graft is a safe and viable option that improves clinical and functional outcomes compared to presurgical function [38].

Graft-Related Complications: The use of bone-patellar tendon-bone autograft is not recommended if patellar tendinopathy is obvious or there are suspicions of partial tendon tear on MRI [49].

Non-Operative Complications and Risks: Corticosteroid injection is not recommended for patellar or quadriceps tendinopathy because it increases the risk of tendon rupture [41]. Anabolic steroid use and local corticosteroid injection into the tendon are associated with both patellar tendon and quadriceps tendon ruptures [27].

Other Considerations: Only about half the subjects who underwent open or arthroscopic patellar tenotomy were competing at their former sporting level at follow-up [47].

Recovery

Light activity (weeks): The provided evidence does not specify a typical week range for light activities such as desk work, driving, or light activities of daily living.

Full activity (months): The provided evidence does not specify a month range for the return to manual work, sport, or full range of motion and strength.

Complete recovery / outcome plateau (months): The provided evidence does not specify a month range for when pain, strength, and final functional outcomes stabilise.

Rehabilitation protocol: Isometric exercise immediately reduced patellar tendon pain, with the effect sustained for at least 45 min [80].

Functional milestones: Surgical treatment of refractory patellar tendinopathy leads to notable improvement in patient-reported outcomes [6]. Arthroscopic patellar release translates into sustained pain relief and functional improvement over a long-term follow-up in athletes [72].

Other Considerations: Surgical treatment of refractory patellar tendinopathy leads to high return-to-play rates [6]. Athletes with patellar tendinopathy were able to return to play without any impact on career longevity [43], and player performance was not affected by the diagnosis of patellar tendinopathy [43]. However, the recurrence rate for patellar tendinopathy is high in elite soccer players [42]. A greater patella alta incidence amongst patellar tendinopathy patients suggests these patients may comprise the recalcitrant patient subgroup who do not improve with current surgical intervention [11]; patients with patella alta may benefit from a biomechanical surgical solution [11]. Surgical reconstruction of chronic patellar tendon ruptures using contralateral bone-tendon-bone graft was a safe and viable option [38]. Quadriceps tendon ruptures have a more guarded prognosis due to incomplete nature and persistent degenerative tissue [76], and results for quadriceps tendon ruptures are adversely affected by chondromalacia or patella alta [76].

Key Evidence

  • [L2] Persistent patellar tendinopathy is associated with worsening of knee pain. [1] (10.1186/s12891-015-0645-8)
  • [L1] Surgical treatment for chronic patellar tendinopathy leads to substantial improvements in functional outcomes. [2] (10.1002/ksa.70284)
  • [L4] Clinical symptoms remained even years after loading-based treatment for patellar tendinopathy, whereas some but not all tendon structures normalized in this longer term follow-up. [3] (10.1177/23259671241280192)
  • [L3] Patients scheduled for surgery due to recalcitrant patellar tendinosis had longer patellar tendons compared to those without a history of patellar tendinosis. [4] (10.1177/2325967123s00268)
  • [L5] Patellar tendon reconstruction in addition to debridement in the setting of significant partial patellar tendon tearing provides the patients with improved functional outcomes and decreases the risk for potential complications. [5] (10.1016/j.eats.2024.102931)
  • [L4] Surgical treatment of refractory patellar tendinopathy leads to notable improvement in patient-reported outcomes and high return-to-play rates. [6] (10.5435/jaaosglobal-d-24-00146)
  • [L4] Arthroscopic surgery for patients with patellar tendinopathy refractory to nonoperative management appears to provide significant improvements in symptoms and function, with improvements maintained for at least 3 years. [8] (10.1177/0363546511410413)
  • [L5] Treatment for patellar tendinopathy continues to evolve, with biologic and less-invasive ultrasound-based treatments showing promise, and surgical intervention providing reliable outcomes. [9] (10.1016/j.arthro.2023.09.004)
  • [L2] Good-quality studies comparing loading programmes and evaluating clinical and mechanistic outcomes are needed in both Achilles and patellar tendinopathy rehabilitation. [10] (10.1007/s40279-013-0019-z)
  • [L3] A greater patella alta incidence amongst patellar tendinopathy patients as defined by SPFA was found to be clinically relevant, as it suggests these patients may comprise the recalcitrant patient subgroup who do not improve with current surgical intervention and may therefore benefit from a biomechanical surgical solution. [11] (10.1007/s00167-020-06372-z)
  • [L5] [12] (10.5435/jaaos-d-15-00703)
  • [L3] The altered movement patterns may be perpetuating symptoms associated with patellar tendinopathy. [14] (10.1177/2325967115576100)
  • [L1] The literature documents several nonsurgical approaches for the treatment of chronic patellar tendinopathy with important limitations in terms of study quality. [15] (10.1177/0363546518759674)
  • [L2] Ultrasound can likely be excluded as a treatment for patellar tendinopathy, while other methods require further investigation. [17] (10.1007/s00167-011-1825-1)
  • [L3] The relationship between the patella and the patellar tendon was identical in both groups; therefore, chronic overload seems to be a major cause of patellar tendinitis. [18] (10.1177/03635465020300031401)
  • [L2] Development of intratendinous alterations in patellar tendons is associated with tendinopathy, but predictive factors could not be identified. [19] (10.1055/a-0633-9098)
  • [L3] 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. [21] (10.1186/1471-2474-15-266)
  • [L4] Operative treatment seems to give good results in most cases of distal patellar tendinosis in athletes when conservative treatment has failed. [22] (10.1007/s00167-006-0135-5)
  • [L4] 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. [24] (10.1007/s00167-012-2100-9)
  • [L5] Clinicians should clinically separate patellar tendinopathy and quadriceps tendinopathy to design more specific rehabilitation programs, as the two entities have distinct anatomical, biomechanical, and epidemiological characteristics. [25] (10.2519/jospt.2019.0611)
  • [L4] Arthroscopic treatment can relieve the pain of refractory chronic patellar tendinopathy. [26] (10.1007/s11999-011-1886-y)
  • [L3] Male gender and having fewer symptoms were possible predictors of effectiveness in patellar tendinopathy patients. [28] (10.1016/j.jsams.2015.04.016)
  • [L3] In patients with patellar tendinopathy, physical test results including strength and flexibility in the lower limb, jump performance, and pain levels during pain-provoking tests were not identified as prognostic factors for patient-reported outcomes after exercise therapy. [29] (10.1177/03635465231200241)
  • [L1] Although a small, immediate clinical response to IGF-1 injections was seen when combined with training, no additional long-term effect of intratendinous IGF-1 was observed on structural and clinical outcomes in patients with patellar tendinopathy. [30] (10.1177/03635465211021056)
  • [L1] There was no superior effect of exercising with a high load magnitude (HSR) compared with a moderate load magnitude (MSR) for the clinical outcome, tendon structure, or tendon function in the treatment of patellar tendinopathy in the short term. [32] (10.1177/0363546520988741)
  • [L3] Consideration of patellar tendinopathy should be made when determining the optimal graft choice for patients undergoing primary ACL reconstruction with autograft tendons. [34] (10.1177/2325967118s00142)
  • [L1] PRP injections offer a clinical benefit and may be considered a suitable option to treat chronic patellar tendinopathy, particularly for complex cases or when nonsurgical rehabilitative approaches have failed, although the evidence is not definitive due to the generally poor quality of current literature. [35] (10.1177/0363546518788320)
  • [L5] The authors advocate for interpreting the results of the systematic review and meta-analysis with caution due to concerns regarding literature search, quality control, and publication bias, concluding that further research is needed to determine if platelet-rich plasma is a suitable nonsurgical alternative for patellar tendinopathy. [36] (10.1177/0363546518788315)
  • [L4] Surgical reconstruction of chronic patellar tendon ruptures using contralateral bone-tendon-bone graft was a safe and viable option that improves clinical and functional outcomes compared to presurgical function. [38] (10.1007/s00167-015-3951-7)
  • [L3] [40] (10.1177/03635465030310031401)
  • [L2] Although mainly mild in nature, patellar tendinopathy is a fairly common condition in elite soccer and the recurrence rate is high. [42] (10.1177/0363546511408877)
  • [L3] Player performance was not affected by the diagnosis of patellar tendinopathy, and athletes were able to RTP without any impact on career longevity. [43] (10.1177/23259671211025305)
  • [L1] [45] (10.1177/0363546510387095)
  • [L3] Both procedures provided virtually all subjects with symptomatic benefit, but only about half the subjects who underwent either open or arthroscopic patellar tenotomy were competing at their former sporting level at follow-up. [47] (10.1177/03635465000280020801)
  • [L3] This large study of over 900 knees demonstrates that patients with evidence of mild-moderate patellar tendinopathy on MRI before undergoing ACL reconstruction with BTB autograft have no notable differences in ACL retear rates and rates of subsequent ipsilateral knee surgery. [48] (10.5435/jaaos-d-24-01217)
  • [L3] The use of BPTB autograft is not recommended if patellar tendinopathy is obvious or there are suspicious of partial tendon tear on MRI. [49] (10.1007/s00167-018-5066-4)
  • [L1] [54] (10.2106/jbjs.e.01181)
  • [L3] [59] (10.1177/0363546506289169)
  • [L5] [62] (10.1002/ksa.12367)
  • [L2] Ultrasonography was more accurate than MRI in confirming clinically diagnosed patellar tendinopathy. [63] (10.1177/0363546506294858)
  • [L2] Extracorporeal shockwave therapy appeared to be more effective and safer than traditional conservative treatments in the management of patients with chronic patellar tendinopathy. [64] (10.1177/0363546506298109)
  • [L1] Extracorporeal shockwave therapy as a solitary treatment during the competitive season has no benefit over placebo treatment in the management of actively competing jumping athletes with patellar tendinopathy who have symptoms for less than 12 months. [65] (10.1177/0363546510395492)
  • [L2] Preseason ultrasound screening can identify symptomatic patellar tendinopathy and associated sequelae during the season, with preseason AP thickness serving as a more stable and precise measure of severity compared to VISA-P scores. [66] (10.1177/2325967123s00252)
  • [L3] Patellar tendinopathy should be considered when determining the optimal graft choice for patients undergoing primary ACL reconstruction with autograft tendons. [68] (10.1177/2325967118807710)
  • [L3] In the group treated nonoperatively, results were better in the patients who had stage 2 tendinopathy than in those with stage 3. [70] (10.1177/03635465000280031901)
  • [L4] Arthroscopic patellar release translates into sustained pain relief and functional improvement over a long-term follow-up in athletes. [72] (10.1186/s12891-017-1851-3)
  • [L2] Partial-thickness tears are located posterior or posteromedially in the proximal patellar tendon, with tendon thickness >8.8 mm strongly correlated with the presence of a tear. [74] (10.1177/0363546519894333)
  • [L4] Quadriceps tendon ruptures have a more guarded prognosis due to incomplete nature and persistent degenerative tissue, with results adversely affected by chondromalacia or patella alta. [76] (10.1177/036354658401200508)
  • [Paper] The described surgical technique is an easy, effective, and inexpensive option with high reproducibility for treating chronic proximal patellar tendinopathy, allowing for a safe return to sports activities without the need for surgical implants. [78] (10.1016/j.eats.2019.07.013)
  • [L5] The posterior region of the proximal patellar tendon is subjected to greater tendinous forces than is the corresponding anterior region. [79] (10.1177/0363546508319311)
  • [L1] Isometric exercise immediately reduced patellar tendon pain with the effect sustained for at least 45 min. [80] (10.1136/bjsports-2014-094386)
  • [L3] Jumper's knee causes mild but long-lasting symptoms after an athletic career. [81] (10.1177/03635465020300051001)
  • [L3] About two thirds of patients with jumper's knee can be expected to have structural tendon changes with neovascularization. [82] (10.1177/0363546508319897)
  • [L3] These results stress the importance of monitoring both symptomatic and asymptomatic tendon structures and in addition highlight that the asymptomatic side should not be used as reference in clinical practice. [83] (10.1007/s00167-019-05495-2)
  • [L1] [85] (10.1177/0363546513518416)
  • [L2] Platelet-rich plasma is a safe and promising therapy in the treatment of recalcitrant patellar tendinopathy. [106] (10.1177/0363546514560726)
  • [L3] Further study is needed on the biomechanical implications of the pivot point and how altering it can affect stress within the patellar tendon, patellofemoral joint, and associated clinical outcomes. [108] (10.1177/2325967118816038)
  • [L1] Sclerosing injections with polidocanol resulted in a significant improvement in knee function and reduced pain in patients with patellar tendinopathy. [109] (10.1177/0363546506289168)
  • [L2] Treatment with BM-MSC or Lp-PRP in combination with rehabilitation in chronic patellar tendinopathy is effective in reducing pain and improving activity levels in active participants. [110] (10.1177/0363546521998725)
  • [Paper] [111] (10.1016/j.eats.2016.10.025)
  • [L4] Treatment with sclerosing injections targeting neovessels in patellar tendinosis has the potential to cure tendon pain and allow patients to return to full patellar-tendon loading activity. [112] (10.1007/s00167-004-0549-x)
  • [L2] Extracorporeal shock wave therapy is an effective intervention and should be considered for greater trochanteric pain syndrome, patellar tendinopathy, and Achilles tendinopathy particularly when other nonoperative treatments have failed. [114] (10.1177/0363546514531911)
  • [L4] Patellar tendons seem to benefit from PRP injections, whereas in the Achilles tendon, PRP application is not indicated neither as a conservative approach nor as a surgical augmentation. [116] (10.1007/s00167-016-4261-4)
  • [L5] Arthroscopic surgery is as effective as open surgery for patellar tendonitis, with a faster return to play when surgery is indicated. [117] (10.1016/j.arthro.2015.09.006)
  • [L2] [118] (10.1007/s00167-007-0455-0)
  • [L5] [119] (10.1177/0363546508322496)
  • [L4] [122] (10.1097/blo.0b013e318030841c)
  • [L4] [125] (10.1177/2325967121994550)
  • [L4] The prevalence of jumper's knee is high in sports characterized by high demands on speed and power for the leg extensors. [128] (10.1177/0363546504270454)
  • [L2] Fibril morphology is abnormal in tendinopathy, but tendon mechanical properties are not. [129] (10.1177/0363546509350915)
  • [L4] The PRP treatment permitted a return to a normal architecture of the tendon as assessed by MRI. [130] (10.1177/0363546513519964)
  • [L2] Although approximately 70% of tendons with structural changes at baseline were normal at follow-up, there was no clear relationship between structure and function. [131] (10.1177/03635465241284648)
  • [L2] Increased preseason patellar tendon thickness is associated with an increased risk of symptomatic patellar tendinopathy and associated sequelae in male NCAA Division I basketball players. [132] (10.2106/jbjs.24.00680)

See Also

References

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[2] Fat pad debridement prolongs return‐to‐sport: A meta‐analysis and meta‐regression of surgical interventions for chronic patellar tendinopathy. Knee Surgery, Sports Traumatology, Arthroscopy. 2026. DOI: 10.1002/ksa.70284

[3] Clinical Outcomes and Tendon Structure at 3- to 4-Year Follow-up After Exercise-Based Treatment of Patellar Tendinopathy: A Prospective Study. Orthopaedic Journal of Sports Medicine. 2024. DOI: 10.1177/23259671241280192

[4] Poster 293: Relationship between patellar tendon length and surgical treatment for patellar tendinosis. Orthopaedic Journal of Sports Medicine. 2023. DOI: 10.1177/2325967123s00268

[5] Patellar Tendon Open Debridement and Reconstruction With Hamstring Tendon Autograft for Severe Patellar Tendinopathy. Arthroscopy Techniques. 2024. DOI: 10.1016/j.eats.2024.102931

[6] A Systematic Review of Surgical Treatment for Refractory Patellar Tendinopathy. JAAOS: Global Research and Reviews. 2025. DOI: 10.5435/jaaosglobal-d-24-00146

[8] Arthroscopic Management of Chronic Patellar Tendinopathy. The American Journal of Sports Medicine. 2011. DOI: 10.1177/0363546511410413

[9] Management of Patellar Tendinopathy. Arthroscopy. 2024. DOI: 10.1016/j.arthro.2023.09.004

[10] Achilles and Patellar Tendinopathy Loading Programmes. Sports Medicine. 2013. DOI: 10.1007/s40279-013-0019-z

[11] Sagittal patellar flexion angle measurement determines greater incidence of patella alta in patellar tendinopathy patients. Knee Surgery, Sports Traumatology, Arthroscopy. 2020. DOI: 10.1007/s00167-020-06372-z

[12] Patellar Tendinopathy: Diagnosis and Treatment. Journal of the American Academy of Orthopaedic Surgeons. 2016. DOI: 10.5435/jaaos-d-15-00703

[14] Lower Extremity Kinematics During a Drop Jump in Individuals With Patellar Tendinopathy. Orthopaedic Journal of Sports Medicine. 2015. DOI: 10.1177/2325967115576100

[15] Nonsurgical Treatments of Patellar Tendinopathy: Multiple Injections of Platelet-Rich Plasma Are a Suitable Option: A Systematic Review and Meta-analysis. The American Journal of Sports Medicine. 2018. DOI: 10.1177/0363546518759674

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[24] Open versus arthroscopic surgical treatment of chronic proximal patellar tendinopathy. A systematic review. Knee Surgery, Sports Traumatology, Arthroscopy. 2012. DOI: 10.1007/s00167-012-2100-9

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[30] No Treatment Benefits of Local Administration of Insulin-like Growth Factor-1 in Addition to Heavy Slow Resistance Training in Tendinopathic Human Patellar Tendons: A Randomized, Double-Blind, Placebo-Controlled Trial With 1-Year Follow-up. The American Journal of Sports Medicine. 2021. DOI: 10.1177/03635465211021056

[32] Clinical Outcomes, Structure, and Function Improve With Both Heavy and Moderate Loads in the Treatment of Patellar Tendinopathy: A Randomized Clinical Trial. The American Journal of Sports Medicine. 2021. DOI: 10.1177/0363546520988741

[34] Advanced Patellar Tendinopathy Is Associated With Increased Rates of Bone-Patellar Tendon-Bone Autograft Failure in Anterior Cruciate Ligament Reconstructions. Orthopaedic Journal of Sports Medicine. 2018. DOI: 10.1177/2325967118s00142

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[36] Is Platelet-Rich Plasma Suitable for Patellar Tendinopathy? Letter to the Editor. The American Journal of Sports Medicine. 2018. DOI: 10.1177/0363546518788315

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[38] Reconstruction of chronic patellar tendon rupture with contralateral bone-tendon-bone autograft. Knee Surgery, Sports Traumatology, Arthroscopy. 2015. DOI: 10.1007/s00167-015-3951-7

[40] Performance Characteristics of Volleyball Players with Patellar Tendinopathy. The American Journal of Sports Medicine. 2003. DOI: 10.1177/03635465030310031401

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[42] Epidemiology of Patellar Tendinopathy in Elite Male Soccer Players. The American Journal of Sports Medicine. 2011. DOI: 10.1177/0363546511408877

[43] Impact of Patellar Tendinopathy on Player Performance in the National Basketball Association. Orthopaedic Journal of Sports Medicine. 2021. DOI: 10.1177/23259671211025305

[45] Skin-Derived Tenocyte-like Cells for the Treatment of Patellar Tendinopathy. The American Journal of Sports Medicine. 2010. DOI: 10.1177/0363546510387095

[47] Open and Arthroscopic Patellar Tenotomy for Chronic Patellar Tendinopathy. The American Journal of Sports Medicine. 2000. DOI: 10.1177/03635465000280020801

[48] The Effect of Mild-to-Moderate Preoperative Patellar Tendinopathy in Autografts Used for Anterior Cruciate Ligament Reconstruction on Postoperative Outcomes. Journal of the American Academy of Orthopaedic Surgeons. 2025. DOI: 10.5435/jaaos-d-24-01217

[49] The presence of patellar tendinopathy in the bone–patellar tendon–bone autograft may increase the risk of anterior cruciate ligament graft failure. Knee Surgery, Sports Traumatology, Arthroscopy. 2018. DOI: 10.1007/s00167-018-5066-4

[54] Surgical Treatment Compared with Eccentric Training for Patellar Tendinopathy (Jumperʼs Knee). The Journal of Bone & Joint Surgery. 2006. DOI: 10.2106/jbjs.e.01181

[59] Pronociceptive and Antinociceptive Neuromediators in Patellar Tendinopathy. The American Journal of Sports Medicine. 2006. DOI: 10.1177/0363546506289169

[62] Dutch multidisciplinary guideline on anterior knee pain: Patellofemoral pain and patellar tendinopathy. Knee Surgery, Sports Traumatology, Arthroscopy. 2024. DOI: 10.1002/ksa.12367

[63] Comparative Accuracy of Magnetic Resonance Imaging and Ultrasonography in Confirming Clinically Diagnosed Patellar Tendinopathy. The American Journal of Sports Medicine. 2007. DOI: 10.1177/0363546506294858

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[65] No Effect of Extracorporeal Shockwave Therapy on Patellar Tendinopathy in Jumping Athletes During the Competitive Season. The American Journal of Sports Medicine. 2011. DOI: 10.1177/0363546510395492

[66] Poster 274: Preseason patellar tendon thickness as a predictor of symptomatic patellar tendinopathy in NCAA Division I Basketball players. Orthopaedic Journal of Sports Medicine. 2023. DOI: 10.1177/2325967123s00252

[68] Advanced Patellar Tendinopathy Is Associated With Increased Rates of Bone–Patellar Tendon–Bone Autograft Failure at Early Follow-up After Anterior Cruciate Ligament Reconstruction. Orthopaedic Journal of Sports Medicine. 2018. DOI: 10.1177/2325967118807710

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[72] Arthroscopic patellar release for treatment of chronic symptomatic patellar tendinopathy: long-term outcome and influential factors in an athletic population. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-017-1851-3

[74] Rethinking Patellar Tendinopathy and Partial Patellar Tendon Tears: A Novel Classification System. The American Journal of Sports Medicine. 2020. DOI: 10.1177/0363546519894333

[76] Patellar and quadriceps tendon ru p tures— jumper's knee. The American Journal of Sports Medicine. 2005. DOI: 10.1177/036354658401200508

[78] Surgical Technique for Chronic Proximal Patellar Tendinopathy (Jumper's Knee). Arthroscopy Techniques. 2019. DOI: 10.1016/j.eats.2019.07.013

[79] Differential Forces within the Proximal Patellar Tendon as an Explanation for the Characteristic Lesion of Patellar Tendinopathy. The American Journal of Sports Medicine. 2008. DOI: 10.1177/0363546508319311

[80] Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. British Journal of Sports Medicine. 2015. DOI: 10.1136/bjsports-2014-094386

[81] Long-Term Prognosis for Jumper's Knee in Male Athletes: Prospective Follow-up Study. The American Journal of Sports Medicine. 2002. DOI: 10.1177/03635465020300051001

[82] Color Doppler Ultrasound Findings in Patellar Tendinopathy (Jumper's Knee). The American Journal of Sports Medicine. 2008. DOI: 10.1177/0363546508319897

[83] Bilateral changes in tendon structure of patients diagnosed with unilateral insertional or midportion achilles tendinopathy or patellar tendinopathy. Knee Surgery, Sports Traumatology, Arthroscopy. 2019. DOI: 10.1007/s00167-019-05495-2

[85] Platelet-Rich Plasma as a Treatment for Patellar Tendinopathy. The American Journal of Sports Medicine. 2014. DOI: 10.1177/0363546513518416

[106] Platelet-Rich Plasma in the Treatment of Patellar Tendinopathy. The American Journal of Sports Medicine. 2014. DOI: 10.1177/0363546514560726

[108] Evaluation of Intrinsic Biomechanical Risk Factors in Patellar Tendinopathy: A Retrospective Radiographic Case-Control Series. Orthopaedic Journal of Sports Medicine. 2018. DOI: 10.1177/2325967118816038

[109] Ultrasound-Guided Sclerosis of Neovessels in Painful Chronic Patellar Tendinopathy. The American Journal of Sports Medicine. 2006. DOI: 10.1177/0363546506289168

[110] Effect of Autologous Expanded Bone Marrow Mesenchymal Stem Cells or Leukocyte-Poor Platelet-Rich Plasma in Chronic Patellar Tendinopathy (With Gap >3 mm): Preliminary Outcomes After 6 Months of a Double-Blind, Randomized, Prospective Study. The American Journal of Sports Medicine. 2021. DOI: 10.1177/0363546521998725

[111] Open Patellar Tendon Tenotomy, Debridement, and Repair Technique Augmented With Platelet‐Rich Plasma for Recalcitrant Patellar Tendinopathy. Arthroscopy Techniques. 2017. DOI: 10.1016/j.eats.2016.10.025

[112] Neovascularisation in chronic painful patellar tendinosis—promising results after sclerosing neovessels outside the tendon challenge the need for surgery. Knee Surgery, Sports Traumatology, Arthroscopy. 2004. DOI: 10.1007/s00167-004-0549-x

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[117] Editorial Commentary: Arthroscopy Is Preferred Over Open Surgery for Patellar Tendonitis. Arthroscopy. 2015. DOI: 10.1016/j.arthro.2015.09.006

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[130] Are Multiple Platelet-Rich Plasma Injections Useful for Treatment of Chronic Patellar Tendinopathy in Athletes?. The American Journal of Sports Medicine. 2014. DOI: 10.1177/0363546513519964

[131] Long-term Prognosis of Patellar Tendinopathy (Jumper’s Knee) in Young, Elite Volleyball Players: Tendon Changes 11 Years After Baseline. The American Journal of Sports Medicine. 2024. DOI: 10.1177/03635465241284648

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b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.