Arthroscopic Debridement Versus Platelet-Rich Plasma Injection: A Prospective, Randomized, Comparative Study of Chronic Lateral Epicondylitis With a Nearly 2-Year Follow-Up Giovanni Merolla, M.D., Fabio Dellabiancia, B.M.E., Annamaria Ricci, M.D., Maria Pia Mussoni, B.S.B., Simonetta Nucci, M.D., Gustavo Zanoli, M.D., Ph.D., Paolo Paladini, M.D., and Giuseppe Porcellini, M.D.
Purpose: The purpose of this prospective, randomized study was to compare the efficacy of autologous plateletrich plasma (PRP) injections and arthroscopic lateral release in treating chronic lateral epicondylitis (LE). Methods: Patients who had a clinical diagnosis of LE confirmed by ultrasound (US) were included in this study. A total of 101 patients received arthroscopic release (n ¼ 50) or US-guided PRP injections (n ¼ 51). Outcomes were assessed using a visual analog scale for pain, the Patient-Rated Tennis Elbow Evaluation (PRTEE), and a calibrated hand dynamometer for grip strength. Results: Both patient groups experienced significant improvement in all measures. Between-group comparisons showed a significantly higher value in the PRP group only for grip strength at week 8 (P ¼ .0073); all other significant differences were in favor of arthroscopy: overall pain (P ¼ .0021), night pain (P ¼ .0013), and PRTEE score (P ¼ .0013) at week 104 and grip strength at weeks 24, 52, and 104 (all P < .0001). Consumption of rescue pain medication was not significantly different between the groups. Conclusions: The present findings suggest that (1) PRP injections and arthroscopic extensor carpi radialis brevis release are both effective in the short and medium term; (2) PRP patients experienced a significant worsening of pain at 2 years; (3) arthroscopic release ensured better long-term outcomes in terms of pain relief and grip strength recovery; and (4) both procedures were safe and well accepted by patients. Level of Evidence: Level II, prospective comparative study.
ateral epicondylitis (LE), or “tennis elbow”, is a common debilitating condition1 affecting the extensor muscles of the forearm attachment to the
L
From the Shoulder and Elbow Unit (G.M., A.R.A., P.P., G.P.), and “Marco Simoncelli” Biomechanics Laboratory (G.M., F.D.), “D. Cervesi” Hospital, Cattolica-AUSL della Romagna; Haematology and Blood Transfusion Unit, “Infermi” Hospital, Rimini-AUSL della Romagna (M.P.M., S.N.), Ambito Territoriale di Rimini; and Casa di Cura S. M. Maddalena (G.Z.), Occhiobello, Italy. The authors report that they have no conflicts of interest in the authorship and publication of this article. The study was approved and registered by the Review Board of “D. Cervesi” Hospital (Cometico AVR/IRST protocol no. 2381/2014/I.5/19). Each author states that his/her institution has approved the human protocol for the study and that all investigations were conducted in line with ethical research principles. Received July 27, 2016; accepted February 10, 2017. Address correspondence to Giovanni Merolla, M.D., Shoulder and Elbow Unit, “D. Cervesi” Hospital, Via L. V. Beethoven 5, 47841 Cattolica, Italy. E-mail:
[email protected] Ó 2017 by the Arthroscopy Association of North America 0749-8063/16692/$36.00 http://dx.doi.org/10.1016/j.arthro.2017.02.009
lateral humeral epicondyle.2,3 The incidence of LE has been estimated to range from 0.3 to 1.1 per 100 patientyears, peaking in the 45 to 54 year age class in both genders.4 LE is associated with heavy physical work,5,6 whereas keyboard use, overhead work, and handtransmitted vibration are considered as risk factors.6 It is well established that stress exceeding the tendon tolerance can result in microtears and that repeated tearing can lead to tendinosis.3 The sites most commonly involved by focal degeneration are the deep fibers of the extensor carpi radialis brevis (ECRB) component of the common extensor tendon origin.7,8 LE is often self-limiting, and several cases are successfully managed by analgesia. A variety of conservative approaches have been devised to treat patients with persistent and severe symptoms, including analgesia, manual and exercise therapy,9,10 orthotic management,11,12 shock wave13,14 and laser therapy,15,16 injections of glucocorticoids or hyaluronic acid,10,17,18 prolotherapy,18,19 acupuncture,20 botulinum toxin,18,21 and, recently, platelet-rich plasma (PRP) and autologous blood (AB) injection.17,22 A 2014
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Cochrane review concluded that the available evidence was insufficient to establish whether PRP therapies importantly affect clinical conditions, since the results of elbow epicondylitis studies pooled in 3 trials were heterogeneous and 2 showed nonsignificant clinical differences in short-term function.23 Arthroscopic or open lateral release as well as other procedures (radiofrequency microtenotomy and percutaneous or endoscopic lateral release) can be considered when conservative treatment fails to provide pain relief and functional recovery.24-27 Arthroscopic release can provide good to excellent outcomes in line with those of other surgical approaches but has the advantage of enabling treatment of any intra-articular conditions.27 Two recent retrospective studies of the effects of PRP injections compared with open surgical release in recalcitrant lateral elbow tendinosis have found that PRP seems to provide better pain relief and function in the short and medium term28 and that it provides similar clinical outcomes and rates of return to work to open surgery.29 There is limited evidence regarding the results of PRP injections and exercise therapy in patients with acute disease, most of whom, however, recover within 52 weeks; physiotherapy and corticosteroid injections provide no clear benefit.30 Although LE has been also described in the acute stage,30 most cases are reported as chronic conditions, where the long-standing histological changes in tendon structure may limit the beneficial effects of conservative treatment.3 The purpose of this prospective, randomized study was to compare the efficacy of autologous PRP injections and arthroscopic lateral release in treating chronic LE. We hypothesized that the 2 treatments would have similar medium- to long-term effectiveness.
Methods Subjects and Inclusion Criteria The study involved patients with chronic LE seen in our hospital’s Shoulder and Elbow Unit outpatient office between June 2010 and December 2012 and was approved by the Institutional Review Board (protocol no. 2381/2014/I.5/19). The study was designed as a comparative prospective study, before patient enrollment. Since the decision for PRP injection or arthroscopic release was not based on specific criteria, but on the clinician’s decision, patients were randomly enrolled in 1 of the 2 treatment groups. Patients gave their informed consent to participate prior to enrollment in the study, which involved a follow-up of 2 years. Assignation to the treatment group was confirmed by the Medical Administration Office of our institution. The protocol was approved by the Institutional Review Board as an institutional health care decision when the study was already in progress, explaining the later date of the approval. A total
number of 110 patients, 55 per group, were eligible for enrollment. Patients received 2 periarticular injections of a PRP preparation (“PRP group”) or arthroscopic lateral elbow release (“arthroscopy group”). Patients were considered eligible if they were 18 or more years old, had had persistent lateral elbow pain for at least 4 months, had a clinical diagnosis of LE confirmed by ultrasound (US), had tried a protocol of elbow exercises, had not received local steroid injections in the preceding 4 months, and were available for the duration of the study. They were excluded if they had a history of elbow trauma, arthroscopic or open elbow surgery, elbow instability, infection or neoplasm, rheumatoid arthritis or other immune disease, severe medical conditions, or were pregnant. Patients were also excluded if they required concomitant procedures or presented with cognitive limitations that could prevent the expression of a valid consent, objective examination, or subjective evaluation. The LE diagnosis was based on the presence of tenderness over the origin of the ECRB, manual tests (provocative Cozen’s and Mill’s test),31 and impaired grip strength32 and was confirmed by US examination performed by a trained musculoskeletal radiologist with established sonographic criteria,8,33 that is, increased tendon size, hypoechoic changes in the tendon echotexture, partial fibril discontinuity, intratendinous calcifications, presence of enthesophytes at the tendon insertion site, and neovascularity. Changes in tendon size and echotexture and fibril discontinuity were detected in all patients. The LE diagnosis was based on the presence of all 3 criteria. After screening, patients were randomized to 2 groups by an orthopaedic surgeon (G.Z.), who was blinded to their characteristics. A standard procedure was employed to generate 2 sets of numbers (Research Randomizer, 2007). PRP Preparation and US-Guided Injection PRP was prepared according to 2011 International Cellular Medicine Society (ICMS) guidelines34 using AB collected at the hematology unit at the time of treatment. Aliquots of AB components were obtained using a commercial kit (PRPS, BiomedDevice, Modena, Italy). A 30-mL sample of venous blood yields 3 to 5 mL of PRP. First, blood was centrifuged at constant acceleration, to obtain 3 fractions: an upper layer containing mostly platelets and white blood cells, a thin, white blood cell-rich intermediate layer (buffy coat), and a bottom layer mostly consisting of red blood cells. The upper layer and the buffy coat were placed in an empty sterile tube. A further centrifugation led to formation of soft pellets of erythrocytes and platelets at the bottom of the tube and of a lighter fraction of platelet-poor plasma that was removed. Finally, pellets were homogenized to obtain PRP.34 A single operator (G.M.) performed all
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the injections under US guidance using a highfrequency 7.5- to 14-Hz linear transducer (MyLab Five, Esaote, Reggio Emilia, Italy) according to the technical guidelines of the European Society of Musculoskeletal Radiology.35 Injections were made on the lateral side of the elbow after disinfection with iodine solution. The PRP preparation was slowly injected into the area showing fibril discontinuity at the ECRB origin (Fig 1). The injection site was covered with a sticking plaster, and patients were asked to refrain from taking analgesics or anti-inflammatories (except rescue medication) for 3 weeks. Each patient received 2 injections administered 2 weeks apart. Arthroscopic Lateral Elbow Debridement All procedures were carried out by the same operator (G.P.) under regional block of the brachial plexus using a standard arthroscopic technique with 3 portals: proximal anteromedial, anterolateral, and midlateral.36 Patients were placed in lateral decubitus position with the shoulder in 90 of abduction and the elbow in 90 of flexion. The anterior aspect of the radiocapitellar joint and the joint capsule were visualized through the anteromedial portal. The first step was to assess the relationship among ECRB, extensor carpi radialis longus (ECRL), and capsule. The undersurface of the ECRB was examined, and the capsule rated according to the classification of Baker et al.37 The articular aspect of the capsule, above the midline of the radiocapitellar joint, was removed through the midlateral portal using a 3.5-mm full radius resector shaver to expose the ECRB origin on the lateral epicondyle. Debridement of the tendon insertion site was continued below the superior capitellum until the ECRL fibers came into view (Fig 2 A and B), avoiding going posterolaterally beyond half the diameter of the radial head and preserving the
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lateral collateral ligament to prevent postoperative instability. The superior aspect of the capitellum delineated the anterior margin of the tendon resection. The ECRB origin was slightly decorticated with a burr (Fig 2C). Finally, the posterior compartment was examined through a posterolateral and a direct posterior portal. At the end of the procedure, the elbow was immobilized in a hinged splint with the elbow in 90 of flexion for 15 days. Gentle elbow range of motion exercises were allowed in the third week until complete range of motion recovery. Strength exercises, forceful gripping, and wrist extension were allowed at 4 weeks. Rescue Pain Medication Rescue pain medication (1,000 mg oral paracetamol [acetaminophen]) was allowed at a maximum dosage of 4 g/day; the amount taken by each patient was recorded at each follow-up visit. The protocol mandated withdrawing pain medication 24 hours prior to each visit; patients were asked to confirm withdrawal during the examination. Outcome Measures and Measuring Instruments The primary outcome measure was pain, which was rated with a visual analog scale (VAS). Secondary outcome measures were the score on the Italian version of the Patient-Related Tennis Elbow Evaluation (PRTEE),38 pain with resisted wrist extension (yes/no), and grip strength. Tenderness to palpation over the lateral epicondyle and additional subjective symptoms (numbness and paresthesia) were further secondary outcomes. All examinations were performed by 2 experienced surgeons (P.P. and A.R.). The PRTEE questionnaire is a 15-item tool specifically designed for LE; 5 items investigate pain, and 10 items investigate the difficulty in performing various activities (6 specific
Fig 1. Ultrasound-guided injection technique. (A) The probe is placed over the lateral epicondyle, along the longitudinal axis of the common extensor tendon origin (left elbow); (B) The platelet-rich plasma (PRP) preparation is injected at the bone-tendon interface and into the extensor carpi radialis brevis (ECRB) tendon. (Arrow, needle at the tendon insertion; arrowheads, PRP preparation injected into and around the ECRB tendon; rh, radial head.)
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Fig 2. Intraoperative findings of arthroscopic lateral elbow release (left elbow). (A) The capitellum and capsule seen from the proximal anteromedial portal (type II degeneration according to Baker et al.37); (B) the capsule is removed with a motorized shaver and a radiofrequency probe, and the extensor carpi radialis brevis (ECRB) is exposed and released from the lateral epicondyle; (C) decortication of the ECRB humeral insertion.
and 4 usual activities) over the preceding week, rated from 0 (no difficulty) to 10 (unable to perform). The overall score ranges from 0 (best) to 100 (worst). Grip strength was recorded using a calibrated hand dynamometer (Jamar Hydraulic Dynamometer, Lafayette Instrument Company, Lafayette, IN, U.S.A.) equipped with dual scale displays for isometric grip force (0 to 90 kg) and a peak-hold needle. Maximum grip strength (expressed as kg) was measured separately by 2 examiners (F.D. and S.N.), who had not been involved in the surgical procedures. Each examiner recorded 3 tests, allowing a 10-minute rest between measurements as described elsewhere.39 The mean of the 6 values was reported as the grip strength value. Patients were asked to rate the pain experienced in the previous 48 hours (overall pain and pain at night) using a printed VAS ranging from 1 (no pain) to 10 (severe pain). The Patient’s Global Assessment was used for subjective assessment of general health status (excellent, good, fair or poor)40; any adverse events were also recorded. Follow-Up PRP group patients were assessed at weeks 2, 4, 8, 12, and 24, at 1 year (week 52 1), and at 2 years (week 104 1). The arthroscopy patients could not be assessed at weeks 2 and 4 due to immobilization and rehabilitation and were evaluated at weeks 8, 12, and 24, at 1 year (week 52 1), and then at 2 years (week 104 1). Statistical Analysis A power analysis was performed considering a 2-point difference in the VAS pain score between the groups, a standard deviation of the pain score of 2.5 points, and a minimal clinically important difference of 1.8 points. Using these parameters and a power of 0.9, a population of at least 41 subjects per group was required. The subjective pain data reported at each follow-up visit were entered in an electronic worksheet (Microsoft Excel for Mac Os 2011) to calculate mean and 95% confidence intervals, standard deviation (SD), and
median and interquartile range (IQR, 25th to 75th percentile). The PRTEE scores were calculated in a similar way; grip strength was reported as the mean of the 3 measurements. Statistical analysis was performed using the MannWhitney test for the equality of populations comparing delta scores (difference from baseline) between groups. Correlations between demographic data and clinical variables were assessed using the Mann-Whitney test and Spearman’s rho. Significance was set at 5%. Interand intraobserver agreement for grip strength was assessed using Spearman’s rho grading system,41 and correlations were graded as 0.00 to 0.19, “very weak”; 0.20 to 0.39, “weak”; 0.40 to 0.59, “moderate”; 0.60 to 0.79, “good”, and 0.80 to 1.0, “very good.”
Results During the screening phase, 9 patients were excluded because they refused treatment (n ¼ 4) or failed to comply with the inclusion criteria (treatment with steroid injection [n ¼ 2], previous open surgery [n ¼ 1], elbow fracture [n ¼ 1], and severe disease [n ¼ 1]), leaving 101 patients, 50 in the PRP group and 51 in the arthroscopy group (Fig 3). Thirty-three patients, 16 (32%) from the PRP group and 19 (38%) from the arthroscopy group, were workers performing heavy physical tasks. No patient was lost to follow-up. Most patients did not live very far from our institution. However, to minimize loss to follow-up, the staff in charge of the appointments tried to meet all patients’ needs with regard to the day and time of visits. There were no significant differences between the groups in terms of baseline demographic characteristics (Table 1). Mean symptom duration before treatment was 23 weeks (range, 18 to 28 weeks) in the PRP group and 29 weeks (range, 22 to 31 weeks) in the arthroscopy group. The capsular tears detected during the arthroscopic procedure were as follows: type 1, intact capsule with fraying of the undersurface of the ECRB
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Fig 3. Flow diagram of the patients included in the study.
tendon, 11 patients (21%); type 2, linear capsular tear, 31 patients (61%); and type 3, complete rupture, 9 patients (18%). No synovial plicae, significant cartilage injuries, or other additional injuries were detected. No postoperative complications occurred in either group. Pain Scores The overall pain scores of the PRP group were slightly but significantly lower than the baseline scores at weeks
2 and 4 and showed further significant decreases at weeks 8, 12, 24, and 52; a reduction was also seen at week 104, but it did not achieve significance (Table 2). The night pain subscore showed a similar trend, with significantly lower values at weeks 2, 4, 8 (P < .0001), 12 (P < .0001), 24 (P < .0001), and 52 (P ¼ .039) and a slight but nonsignificant reduction at week 104. Pain during activity increased at weeks 24 (median, 7; IQR, 6 to 10), 52 (median, 8; IQR, 7 to 9), and 104 (median, 7;
Table 1. Demographic Data of the Study Population Data Variable Patients Mean age, years SD Gender, male/female (%) Mean height, cm SD Mean weight, kg SD Body mass index, kg/m2 SD Dominant side (%) Heavy manual workers (%) Follow-up week (days)
NA, not applicable; SD, standard deviation.
Platelet-Rich Plasma Group 50 47 6.08 29/21 (58/42) 171 8.62 71 13.25 24 3.39 28 (56) 16 (32) 2 (13-16) 4 (29-32) 8 (56-61) 12 (84-91) 24 (177-183) 52 (359-365) 104 (721-732)
Arthroscopy Group 51 46 8.56 27/24 (53/47) 170 8.28 72 13.69 24 3.79 27 (53) 19 (37) NA NA 8 (56-62) 12 (84-90) 24 (178-183) 52 (359-364) 104 (720-733)
P Value .9951 .9147 .8591 .9630 .8953 .6974 .9987 .579
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Table 2. Overall Pain Scores in the 2 Groups Platelet-Rich Plasma Group Variable Baseline Week 2 Week 4 Week 8 Week 12 Week 24 Week 52 Week 104
8 5 5 2 0 1 0 7
Median (IQR) (7-10) (3-6), yP ¼ .035 (3-6), yP ¼ .013 (0-4), yP < .0001 (0-2), yP < .0001 (0-2), yP < .0001 (0-1), yP ¼ .039 (6-9), yP ¼ .431
Mean 7.6 4.9 4.5 2.5 1.5 1.1 0.6 7.1
Arthroscopy Group 95% CI 7.0-9.1 4.1-5.8 3.7-5.3 1.8-3.2 0.8-2.1 0.7-1.5 0.4-0.8 6.8-8.9
9
3 2 0 0 2
Median (IQR) (8-10) NA NA (1-5), yP < .0001 (0-4), yP < .0001 (0-2), yP < .0001 (0-1), yP < .0001 (0-4), yP ¼ .0012
Mean 9 NA NA 3.2 2.2 1.4 1.3 2.1
95% CI 8.6-9.4 NA NA 2.4-3.9 1.5-3.0 0.7-2.2 0.5-2.1 1.6-2.9
P Value* .927 NA NA .198 .099 .503 .341 .0001
CI, confidence interval; IQR, interquartile range (25th to 75th percentile); NA, not applicable. *Comparison between the 2 groups at each follow-up point (Mann-Whitney test). y Comparison with baseline values.
IQR, 6 to 10; all P > .05). Two patients with persistent pain after PRP treatment underwent arthroscopic release after a year and achieved good pain relief 12 months from the procedure. These patients were considered as PRP patients until 1 year from treatment. The overall pain scores of the arthroscopy patients were significantly lower than baseline values at weeks 8, 12, 24, 52, and 104 (Table 2). A similar trend was seen for night pain at weeks 8, 12, 24, 52 (all P < .0001), and 104 (P ¼ .0126). Pain during activity increased at weeks 52 (median, 5; IQR, 3 to 6) and 104 (median, 5; IQR, 3 to 6) but was still significantly different from baseline (P < .05). The pain scores and subscores were stratified to assess the differences between the 2 groups (Table 2). The overall pain scores did not differ significantly at baseline or at weeks 8, 12, 24, and 52 but were significantly lower in the arthroscopy group at week 104 (Table 2). The night pain scores were significantly lower in the arthroscopy group at week 104 (P ¼ .0013). The PRP subjects who performed forceful job-related tasks had a higher but not significantly different pain score during activity compared with the overall pain score at weeks 24, 52, and 104 (Table 3). Consumption of rescue medication was higher (albeit not significantly so) in the PRP group at weeks 24, 52, and 104. PRTEE Scores The PRTEE scores of PRP patients did not decrease significantly at week 2 and showed a slight but nonsignificant reduction at week 4. Significantly lower values were recorded at weeks 8, 12, 24, and 52, whereas the reduction found at week 104 was not significant (Table 4). The scores of the arthroscopy group were significantly lower than baseline at all time points (Table 4). The baseline PRTEE scores of the 2 groups were not significantly different. Values then fell in both groups at weeks 12, 24, and 52, with significantly lower values in the PRP group at week 12. The arthroscopy group showed a significantly lower score at week 104 (Table 4).
Grip Strength Maximum grip strength of PRP patients was not significantly increased at weeks 2 and 4 compared with baseline; significantly higher values were recorded at weeks 8 and 12, whereas the increase found at weeks 24, 52, and 104 was not significant (Table 5). Maximum grip strength of arthroscopic patients showed a slight but nonsignificant increase compared with baseline and was significantly greater at weeks 12, 24, 52, and 104 (Table 5). Baseline grip strength did not differ significantly between the groups. Post-treatment values were significantly higher in the PRP group at week 8 and merely higher at week 12, whereas they were significantly higher in the arthroscopy group at weeks 24, 52, and 104 (Table 5). Interobserver agreement yielded k values ranging from 0.79 to 0.83 for grip strength (good); intraobserver agreement was also good (k ¼ 0.85 to 0.90). Muscle Tenderness Five PRP patients had tenderness to palpation over the lateral epicondyle and pain with resisted wrist extension at weeks 24, 52, and 104. Table 3. Pain during Activity in Subjects Performing JobRelated Forceful Task in the 2 Groups Variable Baseline Week 2 Week 4 Week 8 Week 12 Week 24 Week 52 Week 104
Platelet-Rich Plasma Group 8 (7-10) 5 (3-6), yP ¼ .035 5 (3-6), yP ¼ .013 2 (0-4), yP < .0001 0 (0-2), yP < .0001 8 (6-9), yP ¼ .485 8 (7-9), yP ¼ .575 8 (6-9), yP ¼ .431
Arthroscopy Group 9 (8-10) NA NA 3 (1-5), yP < .0001 2 (0-4), yP < .0001 2 (0-4), yP < .0001 5 (3-6), P ¼ .021 5 (3-6), P ¼ .021
P Value* .896 NA NA .827 .851 .0021 .0165 .0131
NOTE. Values are median (and interquartile range). NA, not applicable. *Comparison between the 2 groups at each follow-up point (Mann-Whitney test). y Comparison with baseline values.
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DEBRIDEMENT VERSUS PLATELET-RICH PLASMA INJECTION Table 4. Patient-Rated Tennis Elbow Evaluation Scores in the 2 Groups Platelet-Rich Plasma Group Variable Baseline Week 2 Week 4 Week 8 Week 12 Week 24 Week 52 Week 104
72 66 64 30 15 10 7 70
Median (IQR) (58-78) (55-75), yP ¼ .565 (55-70), yP ¼ .053 (10-45), yP < .0001 (5-25), yP < .0001 (0-20), yP < .0001 (0-15), yP < .0001 (60-74), yP ¼ .583
Mean 70.1 65.3 63 29.6 17.7 12.3 9 69.2
Arthroscopy Group 95% CI 69.6-83.1 52-66.8 52.3-66.2 22.9-36.3 12.5-22.9 8.6-16.1 6-11 67.4-78.2
76
33 25 14 8.5 18
Median (IQR) (63-81) NA NA (18-48), yP < .0001 (7-41), yP < .0001 (5-28), yP < .0001 (2-16), yP < .0001 (7-32), yP < .0001
Mean 72.5 NA NA 32 27.2 19 14.2 21.2
95% CI 68.2-76.7 NA NA 26-37.9 20.8-33.5 12.8-25 8.3-20 14.6-28.2
P Value* .092 NA NA .565 .035 .208 .431 .001
CI, confidence interval; IQR, interquartile range (25th to 75th percentile); NA, not applicable. *Comparison between the 2 groups at each follow-up point (Mann-Whitney test). y Comparison with baseline values.
Three arthroscopy patients had tenderness and pain to palpation over the lateral epicondyle and pain with resisted wrist extension at weeks 24, 52, and 104. Patient Global Assessment and Adverse Events All patients gave their health status high ratings. Compliance was high, and there were no adverse events.
Discussion The principal findings of this study demonstrate that PRP injection and arthroscopic lateral release are both effective in alleviating pain and restoring function in the short and medium term in patients with chronic LE. PRP patients reported significantly improved pain scores at weeks 2 to 52 and a slight but nonsignificant improvement at week 104; their PRTEE score was significantly higher at the first 2 time points, it decreased from week 8 to week 52 and then significantly rose again at week 104. In the arthroscopy group of patients, the pain and PRTEE scores improved at all time points. However, the consumption of rescue medication was not significantly different in the 2 groups. Patients with tenderness to palpation over the lateral epicondyle and pain with resisted wrist extension were more numerous in the PRP group, whereas Table 5. Grip Strength in the 2 Groups Variable Baseline Week 2 Week 4 Week 8 Week 12 Week 24 Week 52 Week 104
Platelet-Rich Plasma Group 22.0 (5.6) 22.3 (5.2), yP ¼ .512 22.1 (6.6), yP ¼ .542 42.3 (4.6), yP ¼ .0021 49.4 (5.9), yP ¼ .0041 23.4 (6.9), yP ¼ .421 23.6 (4.9), yP ¼ .392 22.8 (4.8), yP ¼ .386
Arthroscopy Group P Value* 26.6 (5.6) .873 NA NA NA NA 28.4 (4.9), yP ¼ .091 .0073 48.4 (4.1), yP ¼ .0012 .976 50.2 (4.2), yP ¼ .0011
