Send letter to journal:
Re: Re: The injected agent with color Doppler– does it matter in tennis elbow? Tennis elbow –impingement

Dear Editor

Tennis elbow – impingement at the common extensor origin? Case report

We thank Dr Knobloch and colleagues for raising questions of the influence of elbow position on the area with high blood flow seen in the common extensor origin and outcome measurement in patients with painful tennis elbow. The first question raised is if the grip strength with 900 elbow flexion might change as well as the grip strength with extended elbow changes in response to the intratendinous injection treatment.[1] This question will be answered in an original article in the future. The other question raised is if the area with high blood flow inside the area of structural changes seen on ultrasound examination is influenced by elbow position. One of the findings on ultrasound examinations of the common extensor origin is “tendon thickening”.[2] We believe that this thickening in some cases is exposed to internal compressive forces. This belief is based on the findings we have made when we have performed ultrasound and colour Doppler examinations during elbow movement. When the elbow is flexed 70-80 degrees there is plenty of space between the head of the radial bone and the lateral epicondyle but during extension of the elbow, the radius makes a movement towards the lateral epicondyle and there will be impingement of the area with structural changes and high blood flow (Figure 1a and 1c). The raised pressure in the thickened tendon due to impingement at the extensor origin will diminish the high blood flow (not detectable), and like on palpation (applying external compressive force), the patient will experience pain. To perform an intratendinous injection targeting the area with high blood flow, the blood flow must be visible on colour Doppler examination which is the case when the elbow is flexed 70- 800, not when the elbow is extended (Figure 1b and 1d). This theory of impingement at the common extensor origin in tennis elbow might be the explanation behind good results in arthroscopic debridement of the area.[3] Other authors have also noted impingement during elbow arthroscopy, Mullet and colleagues classified their findings as degenerative capsular fold.[4] We hope this case rapport is an acceptable answer to the question at the time being. Further studies of the biomechanical prosperities of the elbow and the effect on the soft tissue are highly indicated. Are some individuals more prone to develop recalcitrance painful tennis elbow?

References

[1] Zeisig E, Fahlstrom M, Ohberg L, et al. Pain relief after intratendinous injections in patients with tennis elbow: results of a randomised study. British journal of sports medicine. 2008 Apr;42(4):267- 71.
[2] Levin D, Nazarian LN, Miller TT, et al. Lateral epicondylitis of the elbow: US findings. Radiology. 2005 Oct;237(1):230-4.
[3] Cummins CA. Lateral epicondylitis: in vivo assessment of arthroscopic debridement and correlation with patient outcomes. The American journal of sports medicine. 2006 Sep;34(9):1486-91.
[4] Mullett H, Sprague M, Brown G, et al. Arthroscopic treatment of lateral epicondylitis: clinical and cadaveric studies. Clinical orthopaedics and related research. 2005 Oct;439:123-8.

LEGENDS TO THE FIGURE Figure 1 a-d: Patient clinically diagnosed to have tennis elbow. The common extensor origin is shown in a longitudinal view a. Grey-scale ultrasonography (US) with the elbow flexed 70-800. b. Colour Doppler (CD) shows high blood-flow inside the area with structural changes in the extensor origin with the elbow flexed 70-800. c. US of the same patient with extended elbow. Note the narrowing space between the lateral epicondyle (*) and the head of the radial bone (**) compared to figure a. d. CD shows no blood-flow inside the area with structural changes in the extensor origin with the elbow extended.

Send letter to journal:
Re: The injected agent with color Doppler– does it matter in tennis elbow?

Dear Editor

The injected agent with color Doppler– does it matter in tennis elbow?

We read with great interest the recent randomised, double-blinded controlled cross-over trial by Dr. Zeisig and colleagues evaluating ultrasound and color Doppler guided injections in the proximal forearm in tennis elbow. We would like to comment on some issues.

Grip strength was considered as “the best objective outcome measure” for tennis elbow by the authors. The maximum voluntary grip strength was evaluated with the elbow straight and the wrist in a neutral position. Interestingly, elbow position does play a role for grip strength in tennis elbow [1]. An 8% difference in grip strength between flexion and extension was found to be 83% accurate in distinguishing the affected from the unaffected extremities. In other words, grip strength is used to distinguish tennis elbow from a pain-free extremity based on flexed and extended elbow position. ECRB’s unique anatomy with a sarcomere length maximal with the elbow at 90° of flexion, and minimal between 30° of flexion and 60° of flexion is considered to play a role in this regard. It would be interesting to see whether the grip strength with 90° elbow flexion might change as well in response to the injection therapy by either polidocanol or lidocaine/adrenaline or any other agent.

This idea leads us to another suggestion. Colour Doppler sonography was performed with the arm resting on a table in 70°-80° elbow flexion and pronated wrist. On the other hand, as mentioned before, grip strength was tested on the elbow extended. The area of neovascularisation inside the area of structural changes in the extensor origin might be influenced by elbow position as well. One is tempted to speculate that blood flow in the area of neovascularisation might be changed by elbow extension. In Achilles tendinopathy, the eccentric position of the ankle has been reported to reduce the area of neovascularisation [3]. Therefore, it might be worth considering elbow position for colour Doppler ultrasound as well, since even in the pilot paper on neovascularisation in tennis elbow [5] there is no mention why a 70° to 80° position was used and how neovascularisation might be influenced as a function of elbow flexion.

The authors speculated that regardless of the type of substance injected, the volume injected might have increased the intratendinous pressure which might be responsible for the pain relieving effects. Dr. Zeisig injected 0.5ml per injection with either polidocanol or lidocaine/adrenaline. A recently published, case-only, blinded intervention study among 62 patients with tennis elbow performed a colour Doppler guided injection (90° elbow flexion) of 1ml methylprednisone (40mg/ml) and 0.5ml lidocaine (1%) [4]. Within two weeks symptoms resolved which corresponded to a reduction of the vascular activity in the common extensor origin following the injection. In Achilles tendinopathy, color Doppler guided injection of 1ml lidocaine (2%) and 1ml of 50% dextrose yielded to to good clinical responses as far as pain at rest and during tendon-loading activities was concerned [2].

Studies with various volumes injected by guided color Doppler ultrasound with clinical outcome scores as well as functional data such as tendon metabolism or tendon microcirculation might help in the future to determine the appropiate amount and type of injected agent in tennis elbow. We would like to thank the authors for their inspiring and stimulating work.

References

[1] Dorf ER, Chhabra AB, Golish SR, McGinty JL, Pannunzio ME. Effect of elbow position on grip strength in the evaluation of lateral epicondylitis. J Hand Surg 2007;32:882-6.

[2] Maxwell NJ, Ryan MB, Taunton JE, Gillies JH, Wong AD. Sonographically guided intratendinous injection of hyperosmolar dextrose to treat chronic tendinosis of the Achilles tendon: a pilot study. AJR Am J Roentgenol 2007;189:W215-20.

[3] Ohberg L, Alfredson H. Effects on neovascularisation behind the good results with eccentric training in chronic mid-portion Achilles tendinosis? Knee Surg Sports Traumatol Arthrosc 2004;12:465-70.

[4] Torp-Pedersen TE, Torp-Pedersen ST, Ovistgaard E, Bliddal H. Effect of glucocorticosteroid injections in tennis elbow verified on colour doppler ultrasound: evidence of inflammation. Br J Sports Med 2008 Mar 4 [Epub ahead of print].

[5] Zeisig E, Ohberg L, Alfredson H. Extensor origin vascularity related to pain in patients with tennis elbow. Knee Surg Sports Traumatol Arthrosc 2006;14:659-63.