Chronic lateral epicondylitis of the elbow: A prospective study of low-energy shockwave therapy and low-energy shockwave therapy plus manual therapy of the cervical spine

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Chronic Lateral Epicondylitis of the Elbow: A Prospective Study of Low-Energy Shockwave Therapy and Low-Energy Shockwave Therapy Plus Manual Therapy of the Cervical Spine Jan D. Rompe, MD, Christiane Riedel, MD, Ulrich Betz, Christian Fink ABSTRACT. Rompe JD, Riedel C, Betz U, Fink C. Chronic lateral epicondylitis of the elbow: a prospective study of lowenergy shockwave therapy and low-energy shockwave therapy plus manual therapy of the cervical spine. Arch Phys Med Rehabil 2001;82:578-82.

Key Words: Lithotripsy; Rehabilitation; Tennis elbow. © 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation HE CAUSE OF TENNIS ELBOW remains unclear. Although most studies attribute pain at the lateral epicondyle T to overstrain of the insertion of the extensor carpi radialis 1

Objective: To compare the effects of extracorporeal shockwave therapy (ESWT) alone with a combination of ESWT and manual therapy of the cervical spine in treating chronic tennis elbow. Design: Prospective, matched single-blind control trial. Setting: University hospital clinic. Patients: Thirty patients with unilateral chronic tennis elbow, an unsuccessful conservative therapy during the 6 months before referral, and clinical signs of cervical dysfunction (eg, pressure pain at the C4 –5 and/or C5– 6 level, protraction of the head). Interventions: Three times at weekly intervals all patients received 1000 shockwave impulses of an energy flux density of .16mJ/mm2 at the lateral elbow. Additionally, they underwent manual therapy of the cervical spine and the cervicothoracic junction 10 times (group I). For each patient, a control matched by age (3-yr range) and gender at first conservative treatment was drawn at random from 127 patients who had undergone low-energy shockwave therapy in the same unit in the past 3 years (group II). Follow-up examinations took place at 12 weeks and at 12 months. Main Outcome Measures: The Roles and Maudsley outcome score at 12 months, defining an excellent or good result with no or only occasional discomfort without limitation of activity and range of motion. Results: Neither group differed statistically before the study, with a poor rating for all patients (p ⬎ .05). At 12 months, there was still no significant difference, with the outcome being excellent or good in 56% in group I, and in 60% in group II (p ⬎ .05). Each group showed significant improvement compared with the respective prestudy evaluation (p ⬍ .0001). Conclusion: ESWT may be an effective conservative treatment method for unilateral chronic tennis elbow. The efficacy of additional cervical manual therapy for lateral epicondylitis remains questionable.

From the Department of Orthopaedics, Johannes Gutenberg University School of Medicine, Mainz, Germany. Accepted in revised form July 31, 2000. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Jan D. Rompe, MD, Dept of Orthopaedics, Johannes Gutenberg University School of Medicine, Langenbeckstr. 1, D-55101 Mainz, Germany, e-mail: [email protected]. 0003-9993/01/8205-5995$35.00/0 doi:10.1053/apmr.2001.22337

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brevis and consequent local angiofibroblastic tendinosis,2 some reports suggest a reflex chain between intervertebral joint dysfunction and peripherally localized soft-tissue pain syndromes.3-6 Wright et al7 found that neuronal changes within the spinal cord may be more important than peripheral nociceptor sensitation in the development of chronic musculoskeletal disorders such as tennis elbow. This agrees with a report of an association between lateral epicondylitis and dysfunction in the cervical spine and at the cervicothoracic junction in more than 80% of the patients.8 Cyriax,9 however, argued that patients between the ages of 40 and 60 years with chronic lateral epicondylitis were highly likely also to have x-ray evidence of cervical spondylosis. He denied that pain in the elbow provoked by wrist movements could originate in the neck. In 1992, Labelle et al10 reported that conservative procedures in the treatment of tennis elbow lacked any scientific basis. Since Labelle’s report, new treatment methods have been tested. The finding that physical stimuli activate endogenous nociceptive control systems led to the use of shockwaves to treat persistent tennis elbow.11 Extracorporeal shockwave therapy (ESWT) was said to fulfill major properties of hyperstimulation analgesia, but exactly how shockwave therapy reduces pain is still uncertain.12 Nevertheless, success rates of more than 50% were achieved in prospective controlled studies on recalcitrant tennis elbow and plantar fasciitis.13 We report a comparison of patients treated with shockwaves and manual therapy of the cervical spine with age-matched cases that received only shockwave therapy in a single unit. METHODS Included in this study were patients with chronic lateral epicondylitis of the elbow with pain over the lateral epicondyle for more than 6 months; unsuccessful conservative therapy in the 6 months before referral to our hospital; at least 3 local injections (steroid and/or local anesthetic); at least 10 physical therapy visits (electrotherapy, iontophoresis, kryotherapy, ultrasound); and a positive result on at least 2 of the following provocation tests: (1) palpation of the lateral epicondyle and resisted wrist extension (Thomsen test): with shoulder flexed to 60°, the elbow extended, the forearm pronated, and the wrist extended about 30°, pressure is applied to the dorsum of the second and third metacarpal bones in the direction of flexion and ulnar deviation to stress the extensor carpi radialis brevis and longus; (2) resisted finger extension: with the shoulder flexed to 60°, the elbow extended, the forearm pronated, and

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the fingers extended, the middle finger is extended against resistance; (3) chair test: with the shoulder flexed to 60° and the elbow extended, the patient attempts to lift a chair weighing 3.5kg; and (4) signs of cervical dysfunction, with persistent pain at the C4 –5 and/or C5– 6 level, with the head in a protracted position. Exclusion criteria were: under the age of 18 years; pregnancy; previous surgeries on the lateral epicondyle; previous manual therapy to the cervical spine; bilateral epicondylitis; osteoarthritis of the elbow joints; pathologic, neurologic, and/or vascular findings in the arms; pain in the lateral elbow when the cervical spine was examined; local infection of an arm; rheumatoid arthritis; coagulopathy; other treatments or drugs used in the 6 weeks before the trials began and in the first 3 months after ESWT. Group I included 16 women and 14 men (mean age, 47yr; range, 35– 65yr; mean duration of pain, 38mo; range, 12– 180mo) with lateral elbow and neck pain. All patients were referred to our shockwave unit for treatment of recalcitrant epicondylitis. They received shockwave therapy and manual therapy to the cervical spine. There were 27 right-hand dominant individuals, and the dominant side was affected in 25 cases. A mean of 5.4 ⫾ 1.5 conservative treatment procedures had been completed without success. The patients were not able to work for an average of 4.4 ⫾ 7.2 weeks before the first ESWT. For each elbow studied, a control group (group II) of 16 women and 14 men (mean age, 48yr; range, 37– 68yr; mean duration of pain, 40mo; range, 12–208mo) matched by age (3-yr range) and gender at first conservative treatment was drawn at random from a series of 146 patients who had undergone a monotherapy with low-energy shockwaves in the same unit in the past 3 years. There were 26 right-handed patients, and the dominant arm was affected in 27 patients. An average of 5.5 ⫾ 1.8 unsuccessful conservative therapy procedures had been completed. The mean period of inability to work was 4.5 ⫾ 8.9 weeks before the first ESWT. Treatment The ESWT was applied by an easily maneuverable therapy unit especially designed for orthopedic use,a with the shock-

wave head suspended by an articulating arm for flexible movement of the head in 3 planes. The shockwave head was equipped with an electromagnetic shockwave emitter. Shockwave focus guidance was established by inline integration of an ultrasound probe—a 7.5-MHz sector scanner—in the shock head. According to the consensus report, the features of the device, measured with a fiberoptic hydrophone, are listed in table 1.14 Both groups were treated under the same conditions and the patients were treated singly to avoid influencing one another. Three times, in weekly intervals, 1000 impulses of .16mJ/mm2 were administered at the anterior aspect of the lateral epicondyle at a frequency of 4Hz. No local anesthesia was applied to the treated area, though the treatment is moderately painful. After the last ESWT, patients from group I were referred to physiotherapists certified for manual therapy. They performed soft mobilization therapy of the cervical spine and of the cervicothoracic junction to relieve pain in the C4 –5 and C5– 6 motion segments, and to correct the protraction of the head caused by an increased kyphosis of the neck.15 Therefore, an extension mobilization of the cervicothoracic junction (eg, Maitland16 grade IV) and a flexion mobilization of the high cervical joints were recommended (eg, Maitland16 grade IV). For the intermediate cervical segments, traction and glide movements were suggested (eg, Maitland16 grade II or III⫺). No therapeutic procedures were to be administered to the lateral elbow. There were 10 treatment sessions after the last ESWT. Follow-ups by an independent observer were at 3 months and 12 months after the last application of the ESWT. Evaluation At follow-up, patients were asked about their pain assessment compared with pretreatment conditions. The total outcome was rated according to Roles and Maudsley17: ● Excellent: no pain, full movement, full activity. ● Good: occasional discomfort, full movement, full activity. ● Acceptable: some discomfort after prolonged activities. ● Poor: pain limiting activities. The Roles and Maudsley outcome score17 at 12-month follow-up was defined as the main outcome measure. The extent of pain was specified with a visual analog scale (VAS) ranging

Table 1: Fiberoptic Data on the Shockwave Device Physical Value

Peak positive pressure ⫺6dB focal extend in x, y, z direction

5MPa focal extent, lateral Positive energy flux density Total energy flux density Positive energy of ⫺6dB focus Total energy of ⫺6dB focus Positive energy of 5MPa focus Total energy of 5MPa focus Positive energy of 5mm focal area Total energy of 5mm focal area Rise time Pulse width

P⫹ fx(⫺6dB) fy(⫺6dB) fz(⫺6dB) fx(5MPa) fy(5MPa) ED⫹ ED E⫹(⫺6dB) E(⫺6dB) E⫹(5MPa) E(5MPa) E⫹(5mm) E(5mm) tr tp⫹

Unit

Energy Level 1 (Minimum Value)

Energy Level 2 (Mean Value)

Energy Level 3 (Maximum Value)

MPa mm mm mm mm mm mJ/mm2 mJ/mm2 mJ mJ mJ mJ mJ mJ NS NS

5.5 6.0 6.0 58 2.2 2.2 .016 .04 .38 1.1 NA NA .24 .63 750 1380

14.2 5.2 5.2 55 7.8 7.8 .09 .24 1.6 4.0 NA NA 1.26 3.0 615 1160

25.6 4.8 4.8 49 19 19 .22 .56 3.5 9.0 NA NA 3.5 9.0 481 920

NOTE: Sonocur Plusa provides 8 user-selectable energy levels. The physical data listed are typical values for the minimum energy, medium energy, and a maximum energy. The shockwave parameters are described according to the consensus meeting in February 1997.14 All measurements were acquired with a fiberoptic hydrophone. Abbreviations: NA, not available; NS, not significant.

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ESWT VERSUS ESWT AND CERVICAL MANUAL THERAPY, Rompe Table 2: Total Outcome According to Roles and Maudsley17 at 3- and 12-Month Follow-Up 0 months

Excellent Good Acceptable Poor

3 months

12 months

Group I (n ⫽ 30)

Group II (n ⫽ 30)

Group I (n ⫽ 30)

Group II (n ⫽ 30)

Group I (n ⫽ 27)

Group II (n ⫽ 25)

— — — 100

— — — 100

13.3 26.7 43.3 16.7

23.3 26.7 33.3 16.7

22.3 33.3 33.3 11.1

24 36 20 20

NOTE. Data presented as percentage of patients.

from 0 (no pain) to 10 (maximal pain). The examination was completed independent of the treating physician and comprised the same 4 diagnostic tests that governed entry into the study. Additionally, grip strength was measured bilaterally at the extended and pronated forearm with a vigorimeter,b the pressure being registered in kp/cm2. Reduction of pain, and grip strength, compared with the unaffected side, were regarded as secondary outcome parameters. Statistics For statistical analysis, Wilcoxon-Mann-Whitney’s test for 2 independent samples, the t test for the normally distributed variables of the vigorimeter measures, and Fisher’s exact test and its extension to r ⫻ c tables were used to compare the 2 groups. Comparisons between different examinations were performed with Wilcoxon’s t test for dependent samples and McNemar’s test. The alpha level of significance was set at 5%. RESULTS There was no difference between the groups in the affected side, in gender, age, period of pain, period of inability to work, or number of conservative treatment procedures. All patients could be examined at 3 months. Twelve (40%) patients in group I, versus 15 (50%) patients in group II, had an excellent or good result (table 2). Additionally, the patients were asked to estimate the improvement of pain in percentages, with 0% meaning no relief and 100% meaning complete relief of symptoms. Mean subjective improvement of the symptoms was rated at 62% ⫾ 27% in group I and at 60% ⫾ 34% in group II. Mean grip strength increased to 91% of the unaffected side in group I and to 94% in group II. After 12 months, 27 patients in group I and 25 patients in group II were evaluated. There were 15 (55.5%) excellent or good results in group I and 15 (60%) good or excellent results in group II. Mean subjective improvement was 75% ⫾ 23% in group I and 72% ⫾ 33% in group II. Mean grip strength compared with the contralateral side now amounted to 100% in group I and to 101% in group II. The data of the VAS ratings for 3 months and 12 months are summarized in table 3. There was no statistically significant difference between group I and group II in the Roles and Maudsley scores (extended Fisher

test) and the VAS ratings (Wilcoxon test for independent samples). Within the 2 groups, there was a highly significant improvement on the VAS and on the Roles and Maudsley outcome scores at both follow-ups (p ⬍ .0001). No patient reported additional treatment at the 12-week assessment. Between 3 and 12 months, 3 patients in group I and 2 patients in group II had undergone a release operation. In group I, 2 patients required occasional pain medication, and 3 needed regular medication. In group II, 4 patients took pain medication on a regular basis and 3 took it occasionally. There was no statistically significant difference between groups I and II with regard to additional treatment. DISCUSSION According to a literature review by Heller and Niethard,13 the first prospective controlled study on the effectiveness of extracorporeal shockwaves for the treatment of chronic tennis elbow was published in 1996. At 6-month follow-up, 48% good or excellent outcomes in the treatment group were reported, compared with 6% in the control group, according to the Roles and Maudsley scores; at 12 months, there were 52% versus 6% good or excellent cases.11,18 Krischek et al19 prospectively compared the analgesic effects of ESWT in patients with recalcitrant lateral or medial epicondylitis. They reported 62% good or excellent outcomes in patients with a tennis elbow after 1 year by using the scoring system of Verhaar et al,20 compared with 28% good or excellent outcomes in patients with a golfer’s elbow. Perlick et al21 prospectively compared the outcome after ESWT and after surgery in 60 patients with chronic tennis elbow. They described good or excellent results in the Roles and Maudsley scores in 43% of patients with ESWT and 73% of surgery patients at 12-month follow-up. Twenty-three percent of EWST patients and 10% of surgery patients reported no improvement. In addition to these comparative studies, there are numerous uncontrolled retrospective reports on the efficacious use of shockwaves in the treatment of tennis elbow.22-29 Because inclusion criteria, treatment procedures, and outcome measurements were not standardized, the success rates of these studies—58% to 85%—must be treated with caution. Except for

Table 3: Pain Rating on the VAS at 0, 3, and 12 Months 0 Months

Pressure pain Thomsen test Resisted finger extension Chair test

3 Months

12 Months

Group I

Group II

p

Group I

Group II

p

Group I

Group II

p

6.21 ⫾ 2.65 6.18 ⫾ 1.72 4.62 ⫾ 3.29 5.46 ⫾ 2.11

6.15 ⫾ 2.43 6.24 ⫾ 1.74 4.97 ⫾ 2.84 5.59 ⫾ 2.13

.28 .60 .18 .54

3.99 ⫾ 2.74 3.69 ⫾ 2.52 2.77 ⫾ 2.29 2.98 ⫾ 2.46

3.59 ⫾ 2.29 3.86 ⫾ 2.28 3.01 ⫾ 3.32 3.00 ⫾ 2.40

.65 .55 .58 .81

2.27 ⫾ 2.59 1.93 ⫾ 1.97 1.45 ⫾ 1.84 1.91 ⫾ 2.51

1.97 ⫾ 2.05 2.09 ⫾ 2.01 1.66 ⫾ 1.79 1.97 ⫾ 2.27

.82 .71 .57 .76

NOTE. Data presented as mean ⫾ standard deviation.

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local hematoma, no ESWT-related complications have been reported.30 Our study confirms previous results, leading to good or excellent results in 56% and 60% of the patients at 1-year follow-up. This is comparable to results after local corticosteroid injection,31,32 but in our patients a mean of 2.1 (range, 1–5) steroid injections had not improved the symptoms before ESWT. The quality of the literature about manual therapy of the cervical spine in the treatment of lateral epicondylitis is poor in that there are only a few articles on this topic, and the scientific value of these articles is low. In a MEDLINE search, we found only 5 matches for cervical spine and tennis elbow between 1976 and 1998.5,6,33-35 This is surprising, because in our experience with more than 160 patients with chronic tennis elbow, there have been few who have not had signs of cervical dysfunction, such as localized pressure pain at the lower cervical spine, limitation of range of motion, and protraction of the head. Radiologically, there were signs of cervical spondylarthrosis, depending on the age of our patients. Patients with neurologic deficits or pathologic conditions of the spinal canal in computed tomography or in magnetic resonance imaging were excluded from this study. Gunn and Milbrandt34 discussed a reflex localization of pain from radiculopathy at the cervical spine in patients with a therapy-resistant tennis elbow who had hypomobility of the lower cervical motion segments. Maitland36 found that mobilization, traction, isometric exercises, heat, and/or ultrasound applied to the cervical spine ameliorated the signs and symptoms of lateral epicondylitis. Maigne37 reported complete healing of symptomatic tennis elbow after exclusive manual therapy for the cervical dysfunction in 51 of 92 patients, and significant improvement in another 29 patients. Only 2 patients required surgery. However, inclusion criteria, outcome assessment, and follow-up were not reported. Huguenin38 treated 49 patients with chronic tennis elbow and ipsilateral cervical segmental dysfunction. All 49 patients reported neck pain, an induration of the autochthonous musculature, and a limitation of joint movement. The type of manual treatment was not explained. There were no specific results given, nevertheless, Huguenin stated that his “good” results documented the connection between segmental dysfunction and peripheral muscular symptoms. In his opinion, a treatment success could not be expected until 4 to 8 weeks after manual therapy. De Branche39 analyzed 58 cases with local epicondylagia and a cervical spine pathology. All patients received 1 to 4 manipulations of the cervical spine at weekly intervals. A significant improvement was achieved in 28.4% of the patients for 2 to 4 days, and in 43.1% there was improvement for a longer, but nonspecified period. Only 15.5% of the patients remained pain free. De Branche did not establish selection criteria for manual treatment of the cervical spine. Vicenzino et al35 focused on the immediacy with which manipulative therapy may improve in pain symptoms and function. They used a randomized, doubleblind, placebo-controlled, repeated-measures design to study the initial effects of cervical spine treatment in 15 patients with lateral epicondylitis. All subjects received treatment, placebo, and control conditions. The treatment condition (contralateral glide treatment technique for the cervical spine) produced significant improvement in pressure pain threshold, pain-free grip strength, neurodynamics, and pain scores relative to placebo and control conditions. Vicenzino concluded that manipulative therapy of the cervical spine could elicit a rapid hypoalgesic effect. It was their opinion that impairment of lateral epicondylagia was projected from the hypomobile cervical spine motion segments and that the improvements noted after

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the contralateral gliding technique resulted from treating the source of the referred pain. Moreover, mobilization of the lower cervical spine was thought to produce sensory input sufficient to recruit and activate descending pain inhibitory systems that result in some or all of the pain-relieving effects.40,41 In our study, we focused on possible additive effects of cervical spine manual therapy on patients treated with ESWT for a chronic tennis elbow. With the number of patients available at the author’s institution, we failed to show a positive effect of standardized manual therapy to the cervical spine. Our treatment groups did not differ in their epidemiologic data, but the patients undergoing both procedures were not randomized, and, therefore, selection and information bias cannot be dismissed. CONCLUSIONS Our data underline the value of low-energy ESWT in patients with chronic lateral epicondylalgia; it also questions the usefulness of additional cervical spine manual treatment in these patients. Further studies are needed to establish the optimum treatment regime with ESWT for patients with a recalcitrant tennis elbow, and to clarify the role that manual therapy of the cervical spine plays in the treatment of this enthesiopathy.42 The mechanisms through which ESWT or cervical spine manual therapy produce improvements in pain and function are unknown and require further study. References 1. Pienima¨ki T, Kauranen K, Vanharanta H. Bilaterally decreased motor performance of arms in patients with chronic tennis elbow. Arch Phys Med Rehabil 1998;78:1092-5. 2. Kraushaar BS, Nirschl RP. Current concepts review. Tendinosis of the elbow (tennis elbow). J Bone Joint Surg Am 1999;81:25978. 3. Sutter M. Wesen, Klinik und Bedeutung spondylogener Reflexsyndrome. Schweiz Rundsch Med Prax 1995;42:1341-57. 4. Wyke BD. Neurology of the cervical spinal joints. Physiotherapy 1979;65:72-6. 5. Wanivenhaus A. [Differential diagnosis of epicondylitis humeri radialis] [German]. Z Orthop Ihre Grenzgeh 1986;124:775-9. 6. Waldis MF. [Homann’s operation on the elbow—surgical treatment of a symptom] [German]. Z Orthop Ihre Grenzgeh 1989; 127:606-10. 7. Wright A, Thurnwald P, O’Callaghan J, Smith J, Vicenzino B. Hyperalgesia in tennis elbow patients. J Musculoskeletal Pain 1994;2:83-96. 8. Ehmer B. Orthopa¨dische Erkrankungen des Ellenbogengelenkes. In: Ehmer B, editor. Orthopa¨die und Traumatologie fu¨r Physiotherapeuten. Stuttgart: Ferdinand Enke Verlag; 1998. p 251-5. 9. Cyriax J. Textbook of orthopaedic medicine. 11th ed. London: Ballie`re Tindall; 1982. 10. Labelle H, Guibert R, Joncas J, Newman N, Fallaha M, Rivard CH. Lack of scientific evidence for the treatment of lateral epicondylitis of the elbow: an attempted metaanalysis. J Bone Joint Surg Br 1992;74:646-51. 11. Rompe JD, Hopf C, Ku¨llmer K, Heine J, Bu¨rger R. Analgesic effect of extracorporeal shock-wave therapy on chronic tennis elbow. J Bone Joint Surg Br 1996;78:233-7. 12. Melzack R. Folk medicine and the sensory modulation of pain. In: Wall PD, Melzack R, editors. Textbook of pain. 3rd ed. Edinburgh: Churchill Livingstone; 1995. p 1209-17. 13. Heller KD, Niethard FU. [Using extracorporeal shockwave therapy in orthopedics—a meta-analysis] [German]. Z Orthop Ihre Grenzgeh 1998;136:390-401. 14. Wess O, Ueberle F, Du¨hrßen RN, Hilcken D, Krauß W, Reuner T, et al. Working group technical developments: consensus report. In: Chaussy C, Eisenberger F, Jocham D, Wilbert D, editors. High energy shock waves in medicine. Stuttgart: Thieme; 1997. p 5971. Arch Phys Med Rehabil Vol 82, May 2001

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15. Butler DS. Ein typischer Tennisellenbogen. In: Butler DS editor. Mobilisation des Nervensystems. Berlin: Springer; 1995. p 41520. 16. Maitland GD. Peripheral manipulation. 3rd ed. Oxford: Butterworth Heinemann; 1991. 17. Roles NC, Maudsley RH. Radial tunnel syndrome: resistant tennis elbow as a nerve entrapment. J Bone Joint Surg Br 1972;54:499508. 18. Rompe JD, Ku¨llmer K, Vogel J, Eckardt A, Wahlmann U, Eysel P, et al. [Extracorporeal shock-wave therapy. Experimental basis, clinical application] [German]. Orthopa¨de 1997;26:215-28. 19. Krischek O, Hopf C, Nafe B, Rompe JD. Shock-wave therapy for tennis and golfer’s elbow. Arch Orthop Trauma Surg 1999;119: 62-6. 20. Verhaar J, Walenkamp G, Kester A, Van Mameren H, Van Der Linden T. Lateral extensor release for tennis elbow: a prospective long-term follow-up study. J Bone Joint Surg Am 1993;75:103443. 21. Perlick L, Gassel F, Zander D, Schmitt O, Wallny T. [Comparison of the medium energy ESWT and Mittelmeier surgical therapy in therapy refractory epicondylitis humeri radialis] [German]. Z Orthop Ihre Grenzgeh 1999;137:316-21. 22. Auersperg V. Orthopaedic ESWT of soft tissues. Stoßwelle 1998; 2:16-21. 23. Boxberg W, Perlick L, Giebel G. [Shockwave treatment of therapy refractory soft tissue pain] [German]. Chirurg 1996;67:1174-8. 24. Brunner W, Thu¨ringer R, Ascher G, Neuking A, Flesch A, Solleder A, et al. The extracorporeal shock wave therapy in orthopaedic surgery: results of 443 cases after 3 months. Orthop Praxis 1997;33: 461-4. 25. Go¨bel F, Huber R, Hein W. Stellenwert der extrakorporalen Stoßwellenbehandlung bei therapieresistenter Epicondylitis humeri radialis. [abstract] Z Orthop 1997;135:A95. 26. Lohrer H, Scho¨ll J, Alt W, Hirschmann M. Die extrakorporale Stoßwellentherapie— erste Ergebnisse beim Einsatz in der Sportorthopa¨die. Leistungssport 1998;2:42-4. 27. Staupendahl D, Maier M, Refior HJ. Epicondylitis humeri radialis and ulnaris. User letter. Dornier Medical Systems; 1997. p 35-9. 28. Tsironis K, Burger C, Meurer A, Helbig K, Becker U, Rehm KE. Long-term results of extracorporeal shock wave therapy in insertion tendinitis of the shoulder, elbow and heel. Orthop Praxis 1997;33:669-72. 29. Wolf T, Breitenfelder J. First experiences with extracorporeal shock wave therapy in localized pain conditions of the locomotor apparatus. Orthop Praxis 1996;32:480-3.

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30. Sistermann R, Katthagen BD. [Complications, side-effects and contraindications in the use of middle and high-energy extracorporeal shock waves in orthopedics] [German]. Z Orthop Ihre Grenzgeh 1998;136:175-81. 31. Day BH, Govindasamy N, Patnaik R. Corticosteroid injections in the treatment of tennis elbow. Practitioner 1978;220:459-65. 32. Verhaar JAN, Walenkamp GHIM, van Mamaren H, Kester ADM, Van Der Linden AJ. Local corticosteroid injection versus cyriaxtype physiotherapy for tennis elbow. J Bone Joint Surg Br 1996; 78:128-32. 33. De Marco F, Ricci MG, Bonaiuti D. Clinical trials among worker populations: the value and significance of anamnestic findings and clinical and instrumental tests for diagnosing work-related musculoskeletal disorders of the upper limb. Ergonomics 1998;41: 1322-39. 34. Gunn C, Milbrandt W. Tennis elbow and the cervical spine. Can Med Assoc 1976;114:803-9. 35. Vicenzino B, Collins D, Wright A. The initial effects of a cervical spine manipulative physiotherapy treatment on the pain and dysfunction of lateral epicondylalgia. Pain 1996;68:69-74. 36. Maitland G. Vertebral manipulation. Sydney (Aust): Butterworth; 1986. 37. Maigne R. Manipulative treatment in patients with epicondylagia. Manuelle Med 1988;26:69-72. 38. Huguenin F. Epicondylalgia in manual medicine. Manuelle Med 1988;26:73-6. 39. de Branche B. Analysis of 58 cases of tendinitis in the elbow region treated by manipulation of the cervical spine. Manuelle Med 1988;26:77-80. 40. Bogduk N. Innervation and pain patterns of the cervical spine. In: Grant R, editor. Clinics in physical therapy: physical therapy of the cervical and thoracic spine. New York: Churchill Livingstone; 1994. p 65-76. 41. Grieve G. Referred pain and other clinical features. In: Boyling J, Palastanga N, editors. Grieve’s modern manual therapy: the vertebral column. Edinburgh: Churchill Livingstone; 1994. p. 271-92. 42. Boyer MI, Hastings H. Lateral tennis elbow: Is there any science out there? J Shoulder Elbow Surg 1999;8:481-91. Suppliers a. Sonocur Plus Analgesic Therapy System; Siemens AG, Henkestraße 127, D-91052, Erlangen, Germany. b. Preston Healthcare, Jackson, USA.