treatment of patellar tendinopathy cover

treatment of patellar tendinopathy

case presentation

A healthy, 36-year-old triathlete presents with a 1-year history of persistent right anterior knee pain.  He seems to get significantly worse with running and jumping activities and localizes his tenderness over the inferior pole of the patella.  A limited diagnostic ultrasound shows increased patellar tendon thickness and vascularity.  Which of the following is the most appropriate first line treatment?

A. Corticosteroid injection into infrapatellar bursa
B. PRP over patellar tendon
C. Physical therapy including eccentric exercises
D. Surgical consult

introduction

Patellar tendinopathy (also known as patellar tendinosis, jumper’s knee, or inferior pole patellar tendinopathy) usually presents with anterior knee pain and tenderness at the inferior pole of the patella, causing significant morbidity among those participating in sports.  Most sports medicine providers will encounter patellar tendinopathy (PT) with a fair amount of frequency, particularly in basketball and volleyball [1].

A disturbed collagen distribution, changes in vascularity and cellularity, increased thickness of tendon, and incompletely healed tendon microruptures are common changes observed in patients with patellar tendinopathy (PT) [this pathology [1]. The major cause of this injury is overuse during activities that involve jumping, running, and rapid changes of direction, which are very common movements in sports such as basketball and volleyball.  In both elite sports, 40–50% of professional athletes are affected [2-3].

The management of PT can be active or passive. Active strategies involve tendon-loading regimes, and eccentric training is the most widely adopted approach. It has been shown that there is a 50–70% likelihood of improvement at 3–6-month follow-up with this method [4-6]  Passive treatments for PT include different minimally invasive techniques (MITs), such as corticosteroid and platelet-rich plasma (PRP) injections, extracorporeal shockwave therapy (ESWT), low-energy laser therapy, dry needling (DN), and percutaneous needle electrolysis (PNE).

Image 1: Ultrasound demonstrating patellar tendinosis in a middle aged athlete.  Adopted from [17].

Many authors have previously advocated for eccentric training as the gold standard in the treatment of tendinopathies [2-6].  There has been some debate recently with some more recent reviews and studies.  We reviewed a study by Breda comparing progressive tendon loading and eccentric exercises here.  It was concluded that progressive tendon loading had superior outcomes when compared to eccentric exercises at 24 weeks [8].  Another systematic review reported that the best exercise for improving knee function and reducing pain in the long term is based on EE and heavy slow resistance exercises (HSR) [7].

In the past 20 years of literature, most studies suggest that eccentric training may have a positive effect on the treatment of PT. There are various eccentric exercise programs such as drop squats, squatting on a decline board, squatting on level ground, exercising until tendon pain, training until just before the onset of pain, exercise that involves loading in the eccentric phase only or both phases, and progressing with speed then loading or simply loading.  Young et al. suggest that an eccentric decline squat protocol offers better results at 12 months when compared to a step eccentric protocol for volleyball players with PT; the first group showed a 94% chance of a positive result, in contrast to 41% in the step group [12].  This was one of the landmark papers for eccentric exercises for rehabilitation and many physical therapists follow the protocols.

According to van Ark et al., the current eccentric exercise protocols that are used in-season result in increases in pain [13]. In their study, which included a treatment program with isometric and isotonic exercises in 29 athletes with PT, both exercise programs were shown to reduce pain from PT for athletes in-season.  As mentioned, more recent studies have started to incorporate heavy slow resistance exercises and progressive tendon loading [13]. 

A broad body of literature has shown the correlation between quadriceps shortening and an increased risk of developing long-lasting PT, suggesting that the normalization of quadriceps length may lead to better recovery from this condition [9-10]. Similarly, Zhang ZJ et al. showed an increase in passive muscle tension in the vastus lateralis that is associated with proximal patellar tendon stiffness in athletes, suggesting that a muscle-specific approach is needed in the prevention and rehabilitation of PT [11].

Figure 2.  MRI of patellar tendinosis (T2 weighted image).  Adopted from [17].

According to fascial manipulation theory, patellar tendon pain is often due to an uncoordinated contraction of the quadriceps caused by abnormal fascial tension in the thigh. Therefore, the coordination deficit should be identified instead of directing attention solely to the patellar tendinopathy [10,12]. A broader approach addressing not only the patellar tendon but also other muscle structures, such as the quadriceps muscle and fascial tissue, may be useful for treating PT.

Literature reviews carried out based on the application of the PRP technique on other tendons have concluded that there are no significant differences between PRP or placebo at the 6-months follow-up, although it seems that there may be small differences depending on the injured tendon [14]. However, some reviews and meta-analysis have analyzed the effect of PRP in PT versus other techniques, regardless of whether they are conservative or invasive treatments, finding that PRP seems to be a more effective treatment in the long term than other treatments, such as extracorporeal shockwave therapy (ESWT) [14].

Figure 3.   Adopted from [17].

Some other preliminary studies also exist comparing tenocyte-like cells and dry needling in conjunction with physiotherapy.  There are positive results in regards to improved pain and function when using tenocyte-like cells for lateral epicondylosis [15] and rotator cuff tendonitis [16].

Surgery offers a variable success rate of between 45 and 100% [18].  Surgery should aim to remove the degenerative area of the tendon, usually located in its proximal and deep portion, though there have been descriptions of different isolated or combined procedures such as anterior longitudinal tenotomies (tendon shaving), perforation of the lower pole of the patella, and perforations or resection of the neovessels of the posterior aspect via arthroscopy.  It is felt to be reserved for patients that are still symptomatic despite at least three months of conservative management [18].

Summary

In conclusion, eccentric exercises and additional physiotherapy modalities seem to be the most common treatment provided with consistent evidence of relief of pain and increased function.  A recent study has shown that progressive tendon loading was superior to eccentric exercises, but additional studies are needed.  In regards to injectates, the data remains mixed.  There have not been any long term randomized trials that have shown PRP to have consistent benefit.  Other soft tissue modalities such as dry needling, tenocyte-like cells and percutaneous needle electrolysis may be options, but also need further investigation.

CASE CONCLUSION

Eccentric exercises and additional physiotherapy modalities remain the first line treatment option for patellar tendinopathy.  Physiotherapy (eccentric exercises, progressive tendon loading) has provided the most consistent evidence of relief of pain and increased function.   In regards to injectates, the data remains mixed.  There have not been any long term randomized trials that have shown PRP to have consistent benefit.   These would be second line options.  Surgical consult may be appropriate if the patient failed more than 3 months of conservative management.

More Knee Pain from Sports Medicine Review: https://www.sportsmedreview.com/by-joint/knee/

– More Patellar Tendinopathy from Wiki Sports Medicinehttps://wikism.org/Patellar_Tendonitis

References

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  2. J. Zwerver, S. W. Bredeweg, and I. van den Akker-Scheek, “Prevalence of jumper’s knee among nonelite athletes from different sports,” The American Journal of Sports Medicine, vol. 39, no. 9, pp. 1984–1988, 2011.
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  4. Gaida, J.E.; Cook, J. Treatment options for patellar tendinopathy: Critical review. Curr. Sports Med. Rep. 2011, 10, 255–270.
  5. Young, M.A.; Cook, J.L.; Purdam, C.R.; Kiss, Z.S.; Alfredson, H. Eccentric decline squat protocol offers superior results at 12 months compared with traditional eccentric protocol for patellar tendinopathy in volleyball players. Br. J. Sports Med. 2005, 39, 102–105.
  6. P. Pain, “Using the evidence to guide physical therapist practice,” Journal of Orthopaedic & Sports Physical Therapy, vol. 49, no. 9, pp. 631-632, 2019.
  7. H. Y. Lim and S. H. Wong, “Effects of isometric, eccentric, or heavy slow resistance exercises on pain and function in individuals with patellar tendinopathy: a systematic review,” Physiotherapy Research International, vol. 23, no. 4, Article ID e1721, 2018.
  8. Breda, Stephan J., et al. “Effectiveness of progressive tendon-loading exercise therapy in patients with patellar tendinopathy: a randomised clinical trial.” British journal of sports medicine 55.9 (2021): 501-509.
  9. Sprague, A.L.; Smith, A.H.; Knox, P.; Pohlig, R.T.; Grävare Silbernagel, K. Modifiable risk factors for patellar tendinopathy in athletes: A systematic review and meta-analysis. Br. J. Sports Med. 2018, 52, 1575–1585.
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  11. Zhang, Z.J.; Ng, G.Y.-F.; Lee, W.C.; Fu, S.N. Changes in morphological and elastic properties of patellar tendon in athletes with unilateral patellar tendinopathy and their relationships with pain and functional disability. PLoS ONE 2014, 9, e108337
  12. Young MA, Cook JL, Purdam CR, Kiss ZS, Alfredson H (2005) Eccentric decline squat protocol offers superior results at 12 months compared with traditional eccentric protocol for patellar tendinopathy in volleyball players. Br J Sports Med 39(2):102–105
  13. van Ark M, Cook JL, Docking SI, Zwerver J, Gaida JE, van den Akker-Scheek I et al (2016) Do isometric and isotonic exercise programs reduce pain in athletes with patellar tendinopathy in-season? A andomized clinical trial. J Sci Med Sport 19(9):702–706
  14. Barman, A., Sinha, M.K., Sahoo, J. et al. Platelet-rich plasma injection in the treatment of patellar tendinopathy: a systematic review and meta-analysis. Knee Surg & Relat Res 34, 22 (2022). https://doi.org/10.1186/s43019-022-00151-5
  15. Connell, D.; Datir, A.; Alyas, F.; Curtis, M. Treatment of lateral epicondylitis using skin-derived tenocyte-like cells. Br. J. Sports Med. 2009, 43, 293–298. 
  16. D.-w. Rha, G.-Y. Park, Y.-K. Kim, M. T. Kim, and S. C. Lee, “Comparison of the therapeutic effects of ultrasound-guided platelet-rich plasma injection and dry needling in rotator cuff disease: a randomized controlled trial,” Clinical Rehabilitation, vol. 27, no. 2, pp. 113–122, 2013.
  17. Theodorou, A., Komnos, G. & Hantes, M. Patellar tendinopathy: an overview of prevalence, risk factors, screening, diagnosis, treatment and prevention. Arch Orthop Trauma Surg 143, 6695–6705 (2023).
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