Are they same or different? How do we differentiate?
Patellar tendinopathy is a prevalent tendon pathology in lower limb. This condition only refers to load-related pain in the patella tendon [6]. Patella tendinopathy is also known as the Jumper’s knee as this is commonly seen in young basketball or volleyball players. Presentation of patella tendinopathy is usually pain localised in patella tendon and tenderness on palpation.
Patella femoral pain (Syndrome) is the condition that several factors contribute to. Pain is near the patella or around the patella and it is common in active people [2].
Since these two conditions are quite similar presentation, but affected structures are different, a correct diagnosis will lead to the best treatment.
*There is not only one correct answer for any condition. Each patient should be assessed thoroughly and be given a tailored treatment (patient centred care).
*Subjective history and objective history both needs to be considered to have your diagnosis.
Patella tendinopathy
Aetiology [1, 6]
· Sudden increase in loading or intensity
· Repetitive jumping or hopping
· Young sport athletes
Signs and symptoms [1, 6]
· Pain at the sub-patella during or after the activity
· Tenderness at the inferior pole of the patella with palpation
Assessment [1, 6, 7]
·Declined single leg squat
·Royal London hospital (RLH) test (Palpation on patella tendon with knee flexion and extension) (sen: 88%, Spe, 98%, PPV:98%, NPV:89%) [12]
·Palpation on the patella tendon (sen: 98%, Spe, 94%, PPV:94%, NPV:98%) [12]
·Pain more than 2 on VAS (Visual Analog scale) during or after the activity
· Victorian institute of Sport Assessment less than 80 out of 100
· Pain lasting for at least 3 months after the training
· Thickening of proximal patella tendon on ultrasound
Treatment
Exercise intervention (load management and graded loading depending on the phase of tendon pathology)
·3sets of 15 reps of slow eccentric 25° declined squat reduced tendon stiffness over 12 weeks. This is considered that exercise can promote tendon remodelling and hydration within the tendon [1]. However, this is also used as a pain-provoking assessment.
·Progressive load exercise (isometric-isotonic-explosive exercises) showed better outcome than eccentric exercise at 24 week follow up [6].
· Intensity of the exercise (90% of 1RM vs 55% of 1RM) showed no difference on patients with patella tendinopathy at 12 and 52 week follow-up [5].
Patellofemoral pain (PFP) [2]
· Pain around and near patella without mechanical change on ultrasound
·Lack of hight quality assessment to diagnose (no gold standard)
Aetiology and risk factors [3]
· Sudden increase in load or intensity of the exercise (Load related)
· Quadriceps and gluts weakness, atrophy or inhibition (muscle weakness, inhibition or atrophy)
*Some studies showed the correlation between PFP and hip abductor and weakness in external rotators but others did not. Thus, there is no clear evidence that hip muscle weakness is a cause of PFPS.
·The degree of dynamic valgus during single leg squat and landing may be a cause. Landing technique or single leg may need to be looked at it (coordination) [4].
· Hypomobility of quadriceps, hamstrings, gastrocnemius, soleus, lateral retinaculum and ITB (mobility related).
·Pain catastrophization and fear avoidance can associate with pain and function.
Common in adolescent, athlete, young adult, females, and military. However, this condition can reoccur or be seen in the other knee. Chronic patient might not respond well to the interventions. [3]. This may be related to the stage of chondromalacia patella (advanced stage: stage 3-4) [11].
Signs and symptoms [3]
Pain with loading the joint such as squat, step up, jumping, running and hopping
Pain around the patella
Assessment [3]
·Pain around the patella with loading patellofemoral joint by squatting, step up or climb up and down stairs
*Need to exclude other pathologies that could cause anterior knee pain (tibiofemoral pain)
·PFP cluster [8]
Two clusters to rule in (Sen: 64%, Spe: 93%, PPV:0,76, +LR:8.70)
1, Age<40 years old AND isolated anterior knee pain OR medial patella facet tenderness
2, Age 40-58 years old AND anterior knee pain, mild to moderate difficulty descending stairs, medial facet tenderness and full passive knee extension
Three clusters to Exclude (Sen: 92%, Spe:65%, NPV:0.96, -LR:0.12)
1, Age<58years old AND medial, lateral or posterior knee pain AND no medial or lateral patella facet tenderness
2, Age<58 years old AND lateral knee pain AND medial or lateral patella facet tenderness AND restricted passive knee extension
3, Age 58≧years old
·Positive talar tilt test (Sen: 43%, Spe: 92%, +LR: 5.2, -LR: 0.6) [9, 10]
Outcome measures [3]
·Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS)
·AKPS (originally known as the Kujala scale)
·International Knee Documentation Committee 2000 Subjective Knee Evaluation Form (IKDC),
·Lysholm scale
·Patella femoral pain syndrome scale
Psychological
·Pain catastrophizing scale
·Fear avoidance beliefs questionnaire
Treatment [1, 3]
· Exercise intervention is recommended
· Knee taping and foot orthoses can be used only short term (up to 6 weeks).
· Dry needling should not be used based on research
· Manual therapy should be used in conjunction with other interventions.
Exercise intervention
Combined hip and knee exercise is superior to knee exercise alone for short, mid and long term outcomes.
3sets of 15 reps 25° reduction slow eccentric squat reduced tendon stiffness over 12 weeks. This is considered that exercise can promote tendon remodelling and hydration within the tendon
PFP consensus [3] was published in 2019 to deliver the best possible approach, yet still needs more research. This is like LBP [ref], where quite a few research has been done, yet still trying to figure out so many things, which means that we need to choose interventions that suit each patient. Ex.) some patients may respond well to specific exercise or education while others may find specific exercise or manual therapy helpful.
| Condition | Aetiology | Signs and symptoms | Assessment | Treatment | DDs |
| Patella tendinopathy (PT) | ·Overload on the tendon ·Repetitive jumping | ·Pain with loading ·Localised pain in tendon | ·SL declined squat · RLH test · Palpation test | · Tailored exercise to address tolerance of the tendon to load ·Progressive exercise might be more effective | ·PFP ·Osgood-Schlatter disease · Sinding-Larsen-Johansson disease |
| Patellofemoral pain (PFP) | 1, overload 2, muscle weakness 3,Coordination 4,Hypomobility | ·Pain around the patella ·Multiple factors can contribute to this condition. | · Loading PF joint by squatting, stepping up and down · Patella tilt · PFP cluster | Depending on the cause. Should address and work on hip and ankle as well as knee. | ·Chondromalacia patella (can be a cause of PFP) [11]. · PT · Synovial plica syndrome |
*Pain location and different tests in red might be helpful to differentiate.
References
[1] Lee, W.-C., Ng, G. Y.-F., Zhang, Z.-J., Malliaras, P., Masci, L., & Fu, S.-N. (2017). Changes on Tendon Stiffness and Clinical Outcomes in Athletes Are Associated With Patellar Tendinopathy After Eccentric Exercise. Clinical Journal of Sport Medicine, 1. https://doi.org/10.1097/jsm.0000000000000562
[2] Smith, B. E., Selfe, J., Thacker, D., Hendrick, P., Bateman, M., Moffatt, F., Rathleff, M. S., Smith, T. O., & Logan, P. (2018). Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis. PLOS ONE, 13(1), e0190892. https://doi.org/10.1371/journal.pone.0190892
[3] Willy, R. W., Hoglund, L. T., Barton, C. J., Bolgla, L. A., Scalzitti, D. A., Logerstedt, D. S., Lynch, A. D., Snyder-Mackler, L., & McDonough, C. M. (2019). Patellofemoral Pain. Journal of Orthopaedic & Sports Physical Therapy, 49(9), CPG1–CPG95. https://doi.org/10.2519/jospt.2019.0302
[4] Wyndow, N., de Jong, A., Rial, K., Tucker, K., Collins, N., Vicenzino, B., Russell, T., & Crossley, K. (2015). Foot and ankle mobility and the frontal plane projection angle in asymptomatic controls. Journal of Foot and Ankle Research, 8(S2). https://doi.org/10.1186/1757-1146-8-s2-o43
[5] Agergaard, A. S., Svensson, R. B., Malmgaard-Clausen, N. M., Couppé, C., Hjortshoej, M. H., Doessing, S., Kjaer, M., & Magnusson, S. P. (2021). 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, 49(4), 982–993. https://doi.org/10.1177/0363546520988741
[6] Breda, S. J., Oei, E. H. G., Zwerver, J., Visser, E., Waarsing, E., Krestin, G. P., & de Vos, R. J. (2020). Effectiveness of progressive tendon-loading exercise therapy in patients with patellar tendinopathy: a randomised clinical trial. British Journal of Sports Medicine, 55(9), 501–509. https://doi.org/10.1136/bjsports-2020-103403
[7] Aicale, R., Oliviero, A., & Maffulli, N. (2020). Management of Achilles and patellar tendinopathy: what we know, what we can do. Journal of Foot and Ankle Research, 13(1). https://doi.org/10.1186/s13047-020-00418-8
[8] Décary, S., Frémont, P., Pelletier, B., Fallaha, M., Belzile, S., Martel-Pelletier, J., Pelletier, J. P., Feldman, D., Sylvestre, M. P., Vendittoli, P. A., & Desmeules, F. (2018). Validity of Combining History Elements and Physical Examination Tests to Diagnose Patellofemoral Pain. Archives of Physical Medicine and Rehabilitation, 99(4), 607–614.e1. https://doi.org/10.1016/j.apmr.2017.10.014
[9] Nunes, G. S., Stapait, E. L., Kirsten, M. H., de Noronha, M., & Santos, G. M. (2013). Clinical test for diagnosis of patellofemoral pain syndrome: Systematic review with meta-analysis. Physical Therapy in Sport, 14(1), 54–59. https://doi.org/10.1016/j.ptsp.2012.11.003
[10] Haim, A., Yaniv, M., Dekel, S., & Amir, H. (2006). Patellofemoral Pain Syndrome. Clinical Orthopaedics and Related Research, 451, 223–228. https://doi.org/10.1097/01.blo.0000229284.45485.6c
[11] Aysin, I. K., Askin, A., Dirim Mete, B., Guvendi, E., Aysin, M., & Kocyigit, H. (2018). Investigation of the Relationship between Anterior Knee Pain and Chondromalacia Patellae and Patellofemoral Malalignment. The Eurasian Journal of Medicine, 50(1), 28–33. https://doi.org/10.5152/eurasianjmed.2018.17277
[12] Maffulli, N. (2017). The Royal London Hospital Test for the clinical diagnosis of patellar tendinopathy. Muscles, Ligaments and Tendons Journal, 7(2), 315. https://doi.org/10.11138/mltj/2017.7.2.315
