Pillars for health and fitness – Patellar Tendinopathy
Patellar tendinopathy is a common overuse disorder typically occurring in athletes who participate in sports that require jumping. Also known as patellar tendinitis or tendinosis, it typically results from overstress and progressive trauma to the patellar tendon.
The patella tendon is located just below the patella (knee cap). It has attachments on the patella and the tibial tuberosity on the tibia (shin bone). The role of the patella tendon is to transfer the force of the quadriceps muscles, much like a rope around a pulley, as your knee straightens. In an adult, the patellar tendon is 25-40 mm wide, 4-6 cm long, and 5-7 mm thick. The patellar tendon is made up of dense fibrous connective tissue, uncalcified fibrocartilage, calcified cartilage, and bone. The collagen fibers in the tendon are arranged in a parallel fashion and the tendon appears white. This will be important in understanding later explanation below!
Physiology – Understanding what’s going on!
There are several theories describing the mechanisms of patellar tendinopathy. Repetitive tendon overload is the most commonly proposed theory, where constant exposure to load and overload of the tendon leads to tendon weakness and eventual degeneration in the later stages.
Health tendon structure is made up of a parallel arrangement of strong collagen fibers. Stresses across the tendon can lead to individual fibril degeneration, altering the structure, strength and integrity of the tendon and ability to take on load. Chronic microtrauma leads to failure within the tendon and subsequently leads to alteration at the cellular level. Picture a new, strong rope and how the individual rope fibers are nicely woven. And then imagine a fraying rope; this is the structure of the rope, or in our case the tendon, changing and weakening in structure.
Athletes with patellar tendinopathy typically present with the following findings:
- Pain localised to the inferior pole of the patella. Typically a very defined local sharp sore pain right under the kneecap
- Load-related pain that increases with increased stress on the knee extensors, notably in activities that store and release energy in the patellar tendon
- Other prolonged activities include sitting and stairs and other gym related weight training movements such as squatting, lunges, leg press or knee extensions
Management – Medical
Non-steroidal anti-inflammatory drugs
The use of non-steroidal anti-inflammatory drugs (NSAID’s) in the treatment of tendinopathy remains controversial both in the acute stage and in the chronic stage. NSAIDs have been reported to impede soft tissue healing. Although pain may be reduced, the use of NSAIDs may have a negative effect on tendon repair. In a reactive tendinopathy, this may be a preferred effect, as this may inhibit proteins responsible for tendon swelling.
Corticosteroids are used to decrease pain but also decrease cell proliferation and protein production and therefore could be used in the reactive tendinopathies. Repeated peritendinous corticosteroid has been shown to reduce tendon diameter at 7 and 21 days after injection in tendons.
Surgery for chronic painful tendons has produced varied outcomes, with 50–80% of athletes able to return to sport at their previous level. Surgery in non-athletic people produced poorer results than in active populations. Surgery is considered a reasonable option in those who have failed all conservative interventions.
Management – Conservative
Typically the first pillar to tackle in tendon non-operative management is to firstly manage load, a common theme in this article. For most athletes, being able to effectively manage the intensity and volume of aggravating activities can help in the early stages. This DOES NOT mean complete rest as this may not always be effective. It is advisable to slowly increase the load tolerance of that tendon, gradually exposing the tendon to higher levels of load and allowing the tendon time to both adapt to the new loads and get stronger.
Icing is primarily used for an analgesic effect. Cold therapy helps manage the inflammatory portion of a tendinopathy. Many variables contribute to the effect of icing including the temperature, duration, depth and so on. There is no hard rule on how to ice, however it is recommended not to apply ice prior to sport participation as it may impair function or mask pain leading to re-injury.
A common management for tendon deload is to strap the affected joint to disperse the amount of force through the tendon, assist with joint alignment also for better force distribution and to provide the joint with proprioceptive feedback and increase stability.
Strappings can be applied either via taping or bracing.
Needless to say, a strong tendon can tolerate much more load and adapt to larger changes in force. A mainstay in conservative tendinopathy management is progressive resistance training, aimed at building tendon structure strength, improve blood flow feeding the tendon and improve extensibility of the tendon to take on more and transfer more load. Commonly, later stage strength training involves a lot of jumping and hopping type exercises, aimed at improving the stretch-shortening cycle (SSC) of muscular and tendon contraction.
Return to Sport
This remains a highly debated topic in the physiotherapy community and typically will be determined on the basis of return to joint and performance symmetry. As joint strength and kinematics return, the athlete is slowly exposed to trainings of increasing intensity and duration. As they make their way through to more game simulated situations and can get through without significant pain or dysfunctions, return to sport is then looking more ideal.
Key take home messages!
- Tendinopathies need to concentrate on load management. But this does not always mean complete rest
- There is a continuum on tendon pathology and, depending on the severity, will determine the level of rest and strengthening the tendon will require
- Return to sport can sometimes be a tricky process, with a lot of cooperation required from the team, coaches and athletes to understand the tendon and to gradually build up and adapt the healing tendon