Investigating the relationship between pain level and grip and wrist muscles strength in individuals with lateral epicondylitis: is pain a barrier to strength assessment?

PURPOSE: This study was carried out to examine the relationship between rest, activity, and nighttime pain and grip and isokinetic muscle strength of the wrist muscles in individuals with lateral epicondylitis. METHODS: Fifty-six sedentary individuals aged between 18 and 65 years diagnosed with unilateral lateral epicondylitis volunteered to participate in the study. The level of rest, activity, and nighttime pain was evaluated with visual analog scale (VAS). The grip strengths of both arms were evaluated by averaging a maximum of three grip strength measurements using a hand dynamometer. The strength of both wrist flexor and extensor muscles were evaluated with isokinetic dynamometer at angular velocities of 60 and 180°/s with five and 15 concentric repetitions respectively. RESULTS: There was no significant relationship found between the affected side's grip strength and isokinetic muscle strength with rest, activity and nighttime pain (all P > 0.05). However, there was a difference observed between the affected and unaffected side in grip strength and isokinetic strength measurements of all wrist muscles (all P < 0.05); the unaffected side values were found to be higher. CONCLUSION: The result of this study found no correlation between the stated level of pain and the true muscle strength in the affected hand. In line with these findings, we think that assessments involving strength can be made in other musculoskeletal problems where pain is present. However, the findings may not reflect the true muscle strength which will tend to be underrated.

Anterior radial head subluxation in primary elbow osteoarthritis.

PURPOSE: To investigate elbows with primary osteoarthritis (OA) for the presence of anterior radial head subluxation. METHODS: A total of 71 patients with elbow osteoarthritis and 45 with lateral epicondylitis were initially identified. The baseline characteristics and preoperative elbow X-rays of consecutive patients that had been clinically confirmed with elbow OA or lateral epicondylitis between March 2011 and January 2020 were then retrospectively reviewed. The radiocapitellar ratio (RCR; the ratio of the displacement of the radial head about the diameter of the capitulum) was calculated using lateral views. These RCR values were compared between the OA and lateral epicondylitis cases. RESULT: A significant increase was detected in RCR values between patients in elbow OA and the control group (13.2% (± 10.6) vs -1.2% (± 6.8), P<0.001). Based on receiver operating characteristic curves, RCR values had an excellent area under the curve (0.89) for the detection of elbow OA (Youden index, 0.69; sensitivity, 89%; specificity, 80%). Based on the ROC curve, the cutoff value of RCR was 0.04. Patients with RCR ≥ 0.04 had a significantly higher proportion of cases with elbow OA (risk ratio, 31.50 [95% CI, 11.17-88.82]) than those with RCR ˂ 0.04 (P ˂ 0.001). CONCLUSION: Radial head subluxation is a radiographic finding associated with elbow OA and RCR ≥ 0.04 could be used as an aetiological factor for elbow OA diagnosis.

Demonstrating the relationship of ultrasonographic parameters with disease activity and pain in lateral epicondylitis.

To evaluate the relationship of ultrasonographic evaluation parameters with pain, muscle strength and disease severity in lateral epicondylitis (LE). 64 people were included in present retrospective, cross-sectional study. Activity and rest pain was questioned with Visual Analog Scale (VAS). Also, Patient Rated Tennis Elbow Evaluation (PRTEE) and the maximum grip strength were evaluated. Hypoechoic region, neovascularity, cortical irregularity, enthesopathy and peritendinous fluid or bursitis were evaluated by ultrasonography. 48 of the patients were female and 16 were male. Mean age was 48.53 ±â€…6.12, body mass index was 27.70 ±â€…4.75. 55 (85.9%) hypoechoic region, 31 (48.4%) neovascularity, 21 (32.8%) cortical irregularity, 19 (29,7%) enthesopathy, and 18 (28.1%) peritendinous fluid or bursitis were detected by ultrasonography. When the ultrasonographic findings and clinical findings of the patients were compared, no significant difference was found between the hypoechoic region, cortical irregularity, enthesopathy and clinical findings (P > .05), while the extension grip strength was found to be significantly lower in patients with neovascularity (P = .045). In addition, patients with peritendinous fluid or bursitis, were found to be significantly lower in both flexion (P = .033) and extension (P = .023) grip strength, while PRTEE function (P = .021) subgroup and total (P = .038) scores were significantly higher. Hypoechoic region, cortical irregularities and enthesopathy were not evaluated to be associated with disease severity, pain and muscle strength. Neovascularity was found to be associated only with extension grip strength. Peritendinous fluid or bursitis was found to be associated with both flexion and extension grip strength and disease activity, but not associated with pain.

Evaluation of lateral epicondylopathy, posterior interosseous nerve compression, and plica syndrome as co-existing causes of chronic tennis elbow.

PURPOSE: A great number of patients that suffer from lateral epicondylitis, commonly called tennis elbow (TE), are not successfully treated, meaning, not getting adequate therapeutic effects and the main origin of the pain not being handled appropriately. The hypothesis of the present study is that the inefficiency of the treatment of the chronic TE may often be due to underdiagnosis of posterior interosseous nerve (PIN) entrapment or and plica syndrome, as the authors believe that those pathologies can often occur simultaneously. METHODS: A prospective cross sectional study was conducted. A total of 31 patients met the required criteria. RESULTS: Thirteen (40.7%) of the patients had more than one source of the lateral elbow pain. Five patients (15.6%) had all three examined pathologies. Six patients (18.8%) had TE and PIN syndrome. Two patients (6.3%) had TE and plica syndrome. CONCLUSION: The present study demonstrated concomitant potential sources of lateral elbow pain in patients diagnosed with chronic TE. Our analysis shows how important it is to systematically diagnose patients that present with lateral elbow pain. The clinical characteristics of the three most common causes of chronic lateral elbow pain, meaning, TE, PIN compression, and plicae syndrome were also analyzed. Having adequate knowledge about the clinical aspects of these pathologies can help with a more effective differentiation of the etiology of chronic lateral elbow pain, and with that, a more efficient and cost-effective treatment plan.

Lateral ulnar collateral ligament reconstruction using an autologous triceps tendon graft for subclinical posterolateral rotatory instability in recalcitrant lateral epicondylitis.

PURPOSE: To evaluate midterm outcome of lateral ulnar collateral ligament (LUCL) repair with triceps autograft in patients with PLRI under recalcitrant lateral epicondylitis. METHODS: In total, 25 elbows (23 patients) with recalcitrant epicondylitis longer than 12 months were included into this retrospective study. All patients underwent arthroscopic instability examination. In 18 elbows (16 patients, mean age 47.4 years, range 25-60), PLRI was verified, and an LUCL repair using an autologous triceps tendon graft was performed. Clinical outcome was evaluated before and at least 3 years after surgery using the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form-Elbow Score (ASES-E), Liverpool Elbow Score (LES), Mayo Elbow Performance Index (MEPI), Patient-Rated Elbow Evaluation score (PREE), Subjective Elbow Value (SEV), quick Disabilities of the Arm, Shoulder, and Hand score (qDASH), and the visual analog scale (VAS) for pain. Postoperative satisfaction with the procedure and complications were recorded. RESULTS: Seventeen patients were available at a mean follow-up of 66.4 months (range 48-81). Patient satisfaction postoperatively was reported in 15 elbows as excellent (90%-100%) and 2 as moderate, with 93.1% overall. All scores of the 3 female and 12 male patients significantly increased from pre- to the postoperative follow-up (ASES: 28.3 ± 10.7 to 54.6 ± 12.1, P < .001; MEPI: 49.2 ± 8.3 to 90.5 ± 15.4, P < .001; PREE: 66.1 ± 14.9 to 11.3 ± 23.5, P < .001; qDASH: 63.2 ± 21.1 to 11.5 ± 22.6, P < .001; VAS: 8.75 ± 1.0 to 1.5 ± 2.0, P < .001). All patients suffered from high extension pain preoperatively, which was reported to be relieved after surgery. No recurrent instability or major complication occurred. CONCLUSION: The repair and augmentation of the LUCL with a triceps tendon autograft reached significant improvements; hence, it seems to be a good treatment option for posterolateral elbow rotatory instability with promising midterm results under a low rate of recurrent instability.

No Difference in Complication or Reoperation Rates Between Arthroscopic and Open Debridement for Lateral Epicondylitis: A National Database Study.

PURPOSE: To compare complication rates and 5-year reoperation rates between open debridement (OD) and arthroscopic debridement (AD) for lateral epicondylitis. METHODS: The PearlDiver MUExtr database (2010-2019) was reviewed for patients diagnosed with lateral epicondylitis (queried by International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision [ICD-10] codes) undergoing OD or AD of the common extensor tendon without repair (queried by Current Procedural Terminology codes). Patients were stratified into 2 cohorts: those who underwent AD and those who underwent OD. Nonoperative treatment modalities were reported for both groups within 1 year before index procedure. The rates of 90-day postoperative complications were compared, and multivariate logistic regression analysis was used to identify risk factors for complications. The 5-year reoperation rates, using laterality-specific ICD-10 codes, were also compared between the 2 groups. RESULTS: In total, 19,280 patients (OD = 17,139, AD = 2,141) were analyzed in this study. The most common nonoperative treatments for patients who underwent OD or AD were corticosteroid injections (49.5% vs 43.2%), physical therapy (24.8% vs 25.7%), bracing (2.8% vs 3.2%), and platelet-rich plasma injections (1.3% vs 1.0%). There were no significant differences in radial nerve injuries, hematomas, surgical site infections, wound dehiscence, and sepsis events between the 2 procedures (P = .50). The 5-year reoperation rate was not significantly different between the AD (5.0%) and OD (3.9%) cohorts (P = .10). CONCLUSIONS: For lateral epicondylitis, both AD and OD of the extensor carpi radialis brevis (without repair) were found to have low rates of 90-day adverse events, with no significant differences between the 2 approaches. Similarly, the 5-year reoperation rate was low and not statistically different for those treated with OD or AD. LEVEL OF EVIDENCE: Level III, cross-sectional study.

Assessment of psychiatric disorders and sleep quality in chronic lateral epicondylitis.

OBJECTIVES: Psychiatric disorders including somatization impact pain severity and chronicity. This study aimed to determine sleep quality and the presence of psychiatric disorders in patients with chronic lateral epicondylitis (LE) and to investigate the effect of these comorbidities on pain levels. METHODS: This study included 46 patients diagnosed with chronic LE and 46 healthy controls. Visual analog scale (VAS) was used for the assessment of pain intensity. The prevalence of depression and other psychological factors was examined using Beck Depression Inventory (BDI) and the Symptom Checklist-90-Revised test (SCL-90-R). Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. RESULTS: The mean BDI (p<0.001), all subdivisions of SCL-90-R including somatization (p<0.001), and the mean global PSQI scores (p=0.002) were found to be significantly higher in patients with chronic LE than those in the control group. The presence of depression according to BDI was 41.3% in the patient group. About 60.8% of the patients had somatization and 71.7% had poor sleep quality. VAS scores were significantly higher in the patients with depression, somatization, and low sleep quality indicating a low positive linear relationship (r=0.357, r=0.360, and r=0.463, respectively, and all p<0.05). CONCLUSION: Psychiatric disorders and poor sleep quality are frequently observed in patients with chronic LE. These comorbidities negatively affect pain levels and may be linked to pain chronicity. Therefore, the potential coexistence of psychiatric disorders should be kept in mind when determining the treatment protocols for patients with chronic LE and adjunctive treatment should be given if necessary.

Telephone-based joint protection education in lateral epicondylitis: A randomized controlled trial.

BACKGROUND: Lateral epicondylitis (LE) can occur for many different reasons such as compelling repetitive movements in daily readings, incorrect posture use and work-related factors. Although several treatments are available for LE, the optimal evidence-based treatment remains uncertain. Joint protection techniques have been developed as a self-management intervention to reduce pain and disability and improve functionality by applying ergonomic approaches. OBJECTIVES: This study aimed to investigate the effects of telephone-based follow up on top of a home-based joint protection education programme on pain and functionality in individuals with LE. METHODS: Individuals were randomly assigned into 2 groups; 1) telephone-based group, receiving telephone-based follow-up on top of a home-based joint protection education programme, and 2) home-based group, receiving home-based joint protection education alone. Both groups were given training that increased awareness in LE and home-based exercise programme. In addition, telephone-based group was followed up by telephone three days a week for four weeks. RESULTS: Improvements from baseline to 4th week in Turkish version of the Patient-Rated Tennis Elbow Evaluation-pain (p = 0.001; effect size = 1.11) and function (p < 0.001; effect size = 1.77), Upper Extremity Functional Index (p = 0.001; effect size = 0.85) and The Turkish version of the Joint Protection Behavior Assessment-Short Form (p < 0.001; effect size = 1.54) in the telephone-based group were significantly higher than the improvements in the home-based group. CONCLUSIONS: Telephone-based follow-up in individuals with LE contributed to the awareness of pain, functionality and joint protection methods. Telephone-based joint protection education programmes can offer a health service within the scope of preventive and protective intervention programmes for LE.

Radiocapitellar incongruity of the radial head in magnetic resonance imaging correlates with pathologic changes of the lateral elbow stabilizers in lateral epicondylitis.

OBJECTIVE: Post-traumatic posterolateral rotatory instability (PLRI) can be shown as radiocapitellar incongruity or posterior translation (PT) of the radial head in magnetic resonance imaging (MRI). We aimed to evaluate whether PT correlated with pathologic changes of lateral elbow stabilizers in patients with lateral epicondylitis. MATERIALS AND METHODS: In MRIs of 160 patients with lateral epicondylitis, we measured PT of the radial head in the sagittal images. We qualitatively graded five lesions of the lateral elbow structures that included common extensor tendon (CET) lesion (grade 1-3), lateral collateral ligament complex (LCLC) insufficiency (grade 0-2), and absence or presence of bone marrow signal change, osteochondral lesion, and calcification. We analyzed whether the PT correlated with pathologic changes of the lateral elbow stabilizers and evaluated the diagnostic value of the PT for severe lesions. RESULTS: The average PT was 1.9 mm. The PT correlated with both the CET lesion (p < 0.001) and LCLC insufficiency (p < 0.001). The optimal cutoff values of the PT for grade 3 CET lesion and grade 2 LCLC lesion were 2.6 and 2.8 mm, respectively. When potential PLRI was defined as the PT of > 3.4mm as suggested for post-traumatic PLRI, 21 patients had potential PLRI. The positive predictive values of the PT > 3.4mm were 76% for grade 3 CET lesions and 67% for grade 2 LCLC insufficiency. CONCLUSION: This study demonstrates that PT of the radial head correlates with pathological changes of the lateral elbow stabilizers. As radiocapitellar incongruity is easy to measure quantitatively, it can be used for screening potential PLRI in patients with lateral epicondylitis.

Efficacy of Nonoperative Treatments for Lateral Epicondylitis: A Systematic Review and Meta-Analysis.

BACKGROUND: Lateral epicondylitis is a common overuse injury affecting approximately 1 to 3 percent of the population. Although symptoms may disappear spontaneously within 1 year, the clinical guidelines for conservative treatment are not clear. The authors' objective was to examine the outcomes of nonsurgical treatments for lateral epicondylitis through a meta-analysis and provide a treatment recommendation using the available evidence. METHODS: The authors searched the PubMed, EMBASE, Scopus, and Web of Science databases to identify primary research articles studying conservative treatments (electrophysiotherapy, physical therapy, and injections) for lateral epicondylitis. The authors included randomized controlled trials published in peer-reviewed journals. Data related to outcomes (pain, grip strength, Patient-Rated Tennis Elbow Evaluation score, and Disabilities of the Arm, Shoulder and Hand score) and complications were extracted. RESULTS: Fifty-eight randomized controlled trials were included in the meta-analysis. Electrophysiotherapy was effective in improving pain [mean difference, -10.0 (95 percent CI, -13.8 to -6.1)], Patient-Rated Tennis Elbow Evaluation score [mean difference, -10.7 (95 percent CI, -16.3 to -5.0)], and Disabilities of the Arm, Shoulder and Hand score [mean difference, -11.9 (95 percent CI, -15.8 to -7.9)]; and physical therapy improved pain [mean difference, -6.0 (95 percent CI, -9.7 to -2.3)] and Patient-Rated Tennis Elbow Evaluation scores [mean difference, -7.5 (95 percent CI, -11.8 to -3.2)] compared to placebo. Injections did not improve any outcome measures. Patients who received electrophysiotherapy and injections reported higher adverse effects than physical therapy patients. CONCLUSIONS: Patients who received electrophysiotherapy and physical therapy reported statistically and clinically improved scores in pain and function compared to placebo. Injections may put patients at higher risk for adverse effects compared to other conservative treatments. When managing lateral epicondylitis conservatively, electrophysiotherapy and physical therapy should be prioritized before other interventions. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

Effect of autologous adipose-derived mesenchymal stem cell therapy in combination with autologous platelet-rich plasma in the treatment of elbow tendinopathy.

Tendinopathy is a common condition of both the athletic and general population and can be associated with significant pain and disability. The ability of mesenchymal stem cells (MSCs) to differentiate along a mesodermal cell lineage, including tenocytes, and secrete various bioactive regenerative and anti-inflammatory molecules has seen them considered as a future reparative therapy for tendinopathy. Preclinical trials with MSCs have shown promising positive functional and structural outcomes in several connective tissue related conditions. A 52-year-old male professional masters golfer presents with a clinical history of common extensor origin tendinopathy of the elbow. Subsequent formal ultrasound showed evidence of a large intrasubstance tear. The patient underwent intratendinous autologous adipose-derived MSC therapy in combination with autologous platelet-rich plasma. Following treatment, the patient reported progressive improvement as measured by the validated Numeric Pain Rating Scale and Patient-Rated Tennis Elbow Evaluation score. Repeat imaging showed successful regeneration of tendon-like tissue.

The effect of manual therapy to the thoracic spine on pain-free grip and sympathetic activity in patients with lateral epicondylalgia humeri. A randomized, sample sized planned, placebo-controlled, patient-blinded monocentric trial.

BACKGROUND: The treatment of first choice for lateral epicondylalgia humeri is conservative therapy. Recent findings indicate that spinal manual therapy is effective in the treatment of lateral epicondylalgia. We hypothesized that thoracic spinal mobilization in patients with epicondylalgia would have a positive short-term effect on pain and sympathetic activity. METHODS: Thirty patients (all analyzed) with clinically diagnosed (physical examination) lateral epicondylalgia were enrolled in this randomized, sample size planned, placebo-controlled, patient-blinded, monocentric trial. Pain-free grip, skin conductance and peripheral skin temperature were measured before and after the intervention. The treatment group (15 patients) received a one-time 2-min T5 costovertebral mobilization (2 Hz), and the placebo group (15 patients) received a 2-min one-time sham ultrasound therapy. RESULTS: Mobilization at the thoracic spine resulted in significantly increased strength of pain-free grip + 4.6 kg ± 6.10 (p = 0.008) and skin conductance + 0.76 µS ± 0.73 (p = 0.000004) as well as a decrease in peripheral skin temperature by - 0.80 °C ± 0.35 (p < 0.0000001) within the treatment group. CONCLUSION: A thoracic costovertebral T5 mobilization at a frequency of 2 Hz shows an immediate positive effect on pain-free grip and sympathetic activity in patients with lateral epicondylalgia. CLINICAL TRIAL REGISTRATION: German clinical trial register DRKS00013964, retrospectively registered on 2.2.2018.

Comparison of radial extracorporeal shockwave therapy with ultrasound therapy in patients with lateral epicondylitis.

PURPOSE: Patients suffering from lateral epicondylitis exhibit diminished mobility due to pain. The aim of the study was to compare the efficacy of both shockwave and ultrasound therapies in patients with lateral epicondylitis. METHODS: The shockwave group consisted of 117 patients, 63 patients constituted the ultrasound group, and 18 patients made up the control group. The "University of Peloponnese Pain, Functionality and Quality of Life Questionnaire" was used for the evaluation of pain, functionality, and quality of life on a five-point Likert scale, pre-treatment, post-treatment, and at 4-week follow-up. RESULTS: The pain was reduced and the functionality and quality of life were improved in both the shockwave and ultrasound groups post-treatment (p < 0.001) and at 4-week follow-up (p < 0.001), but the results in the ultrasound group were not as pronounced as in the shockwave group (p < 0.001). CONCLUSION: Both radial shockwave and ultrasound therapies were significantly effective in patients with lateral epicondylitis. However, ultrasound therapy was less effective than shockwave therapy.

Comparison of corticosteroid injection and ozone injection for relief of pain in chronic lateral epicondylitis.

To evaluate and compare the therapeutic effects of corticosteroid and ozone injections in the alleviation of pain associated with chronic lateral epicondylitis . Data was collected from the medical records of 80 patients (56 women, 24 men ; average age : 45.8±7.5). Corticosteroid injection was performed once a week for three times, and ozone was injected 6-8 times at 3 day intervals. No additional analgesics were given. Pain assessment was made by means of Verhaar scores before and after the first injection, on 3rd, 6th and 9th months. The duration of pain was 24.4±12.5 months and the right side was more commonly affected (47, 58.8% vs. 33, 41.2%). Corticosteroid and ozone groups were similar with respect to age (p=0.45), gender distribution (p=0.43) and side of epicondylitis (p=0.88). Pain scores at rest, at compression and on activity were not different in two groups before and following injection. Notably, ozone group displayed better scores compared to corticosteroid in terms of pain on 3rd, 6th and 9th months after injection (p<0.001 for all). Our results demonstrated that ozone injection can be an effective therapeutic option for CLE patients who are refractory to conservative treatment.

Management of lateral epicondylitis.

Lateral epicondylitis is the most common cause of lateral elbow pain. Although also known as tennis elbow, lateral epicondylitis often develops as a work-related condition and therefore constitutes a major public health issue. This article reviews the pathophysiological factors involved in lateral epicondylitis, as well as the tools available for establishing the diagnosis and ruling out other causes of lateral elbow pain. Finally, the non-operative and surgical treatment options are discussed in detail.

[Arthroscopic treatment of chronic lateral epicondylitis. Short-term results of 3 cases]. / Tratamiento artroscópico de la epicondilitis lateral crónica. Resultados a corto plazo de tres casos.

OBJECTIVE: To assess the outcome of arthroscopic release in three patients with chronical lateral epicondylitis. MATERIAL AND METHODS: Arthroscopic release in three patients with lateral epicondylitis is performed. Mayo Clinic scale for evaluation of results is used. A review and discussion of the literature is made. RESULTS: Three patients, two female and one male, the common activities was principal labors, not athletes. Patients had significant pain. It was the principal symptom that affect the score of the rating scale. These scores improved after surgery. It was achieved early return to normal daily activities. No neurological complications were reported. DISCUSSION: Arthroscopic treatment was an alternative safe and effective for treating chronical lateral epicondilitis in this three cases. It allows simultaneous joint exploration for diagnostic purposes and to treat associated pathologies. Broader Series and studies are necessary in order to establish definitive protocols in our cases.

OBJETIVO: Mostrar el resultado a corto plazo de la liberación artroscópica en pacientes que presentan epicondilitis crónica lateral. MATERIAL Y MÉTODOS: Se realiza liberación artroscópica de tres pacientes con epicondilitis lateral. Seguimiento de seis meses. Se utiliza la escala de Clínica Mayo para valoración de resultados. Se lleva a cabo revisión y discusión de la literatura. RESULTADOS: Dos pacientes del género femenino y uno del género masculino dedicados a las actividades cotidianas, no deportistas. El dolor fue el síntoma capital que afectó el puntaje de la escala de valoración. Estos puntajes mejoraron luego de la cirugía. Se logró retorno precoz a sus actividades cotidianas. No se reportaron complicaciones neurológicas. DISCUSIÓN: El tratamiento artroscópico resultó una alternativa segura y eficaz para el tratamiento de la epicondilitis lateral en estos tres pacientes, el cual permite realizar simultáneamente exploración articular con fines diagnósticos y tratar patologías asociadas. Se requieren series más amplias y estudios comparativos a fin de establecer protocolos definitivos en nuestra casuística.

Predictors for outcome in acute lateral epicondylitis.

BACKGROUND: Lateral epicondylitis or tennis elbow is a frequent condition with long-lasting symptoms. In order to identify predictors for treatment success and pain in lateral epicondylitis, we used data from a randomized controlled trial. This trial investigated the efficacy of physiotherapy alone or combined with corticosteroid injection for acute lateral epicondylitis in general practice. METHODS: The outcomes treatment success and pain score on VAS were assessed at 6, 12, 26 and 52 weeks. We ran a univariate binary logistic regression with generalized estimating equations (GEE) and subsequently an adjusted multilevel logistic regression to analyze the association between potential prognostic indicators and the outcome success/ no success. To assess the changes in pain score we used a two-level multilevel linear regression (MLR) followed by an adjusted MLR model with random effects. RESULTS: The most consistent predictor for reduced treatment success at all time points was a high Pain Free Function Index score signifying more pain on everyday activities. Being on paid sick-leave and having a recurring complaint increased short term treatment success but gave decreased long-term treatment success. The patients reporting symptoms after engaging in probable overuse in an unusual activity, tended towards increased treatment success at all time-points, but significant only at 12 weeks. The most consistent predictor of increased pain at all time points was a higher overall complaints score at baseline. CONCLUSIONS: Our results suggest that in treating acute lateral epicondylitis, a consideration of baseline pain, a registration of the patient's overall complaint on a VAS scale and an assessment of the patient's perceived performance in everyday activities with the Pain Free Function Index can be useful in identifying patients that will have a more protracted and serious condition. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00826462 . Date of registration January 22, 2009. The Trial was prospectively registrated.