Authors: Garrett Koehn, Lexi Jackson, Elizabeth Ablah, Hayrettin Okut, Andrew Porter
Categories: Brief Report, dry needling, prolotherapy, return to recreational activities, tendinosis, tenotomy
Source: Kansas Journal of Medicine
Overuse injuries such as tendinosis are a common complaint at sports medicine clinics. When conservative management for tendinosis has failed, ultrasound-guided tendon fenestration and injection procedures, such as dry needling, needling tenotomy, autologous whole blood injections, and prolotherapy, can be utilized for treatment. This study examined the effectiveness of these procedures for pain improvement and ability to return to activity for patients with tendinosis.
This study involved a chart review of patients 15 years or older who underwent at least one treatment for tendinosis at a sports medicine clinic between January 1, 2014 and April 17, 2019. Eligible patients had at least one of the following 1) percutaneous dry needling, 2) percutaneous needle tenotomy, 3) autologous whole blood injection, and/or 4) prolotherapy. A Current Procedural Terminology (CPT) code query was used to screen patient charts for study inclusion.
In total, 680 patients’ data were reviewed, and 343 patients met inclusion criteria. Patients underwent a total of 598 unique procedures. Dry needling represented most procedures (62.8%, n = 375). Most patients reported diminished pain at follow up (73.0%, n = 268). Prolotherapy had the highest percentage among the follow up patients reporting diminished pain (81.0%, n = 17). Most patients were able to return to activity at follow-up (47.4%, n = 172). A greater proportion of patients with autologous whole blood injection were able to return to activity (60.7%, n = 85).
Most patients with tendinosis who underwent tendon fenestration or injection procedures reported diminished pain at follow-up. Autologous whole blood injection may be more likely to diminish patient pain and allow return to activity than other procedure types. More research is needed across all anatomical sites to compare the generalized effectiveness of these procedures.
Keywords: dry needling, tenotomy, prolotherapy, tendinosis, return to recreational activities
It is recommended that American adults participate in at least 150 minutes per week of moderate-intensity aerobic physical activity for health benefits, such as decreased risk of chronic disease and mortality. 1 Despite these benefits, physical activity increases the risk of injury to muscles and tendons due to increased mechanical stress, especially during times of increasing intensity, frequency, and duration.2–4 Patients present to sports medicine clinics with overuse injuries at twice the frequency of acute injuries and make up nearly 50% of all sports injuries.5,6
Tendinosis is an overuse injury of tendon degeneration without clinical or histologic signs of an inflammatory response.2 Tendinosis causes chronic pain and dysfunction that can prevent afflicted individuals from participating in physical activity, occupation-related activities, and even activities of daily living.2
Treatment for tendinosis consists of conservative management, followed by ultrasound-guided needling and injection procedures, and lastly surgery for intractable cases.7 Conservative management consists of activity modifications, physical therapy, and/or home therapy with a focus on eccentric strengthening, and instrument assisted soft tissue massage.2 Conservative management does not always provide long-term relief, sometimes requiring further interventions.8
Second-line treatment of tendinosis can consist of a variety of ultrasound-guided, minimally invasive procedures. These procedures can focus on percutaneous tendon fenestration alone (e.g., dry needling, tenotomy) or be coupled with injections of corticosteroids, hyperosmolar dextrose (prolotherapy), autologous whole blood, or autologous platelet-rich plasma (PRP).2,8 Injection therapies utilizing prolotherapy, autologous whole blood, or PRP yield better long-term pain and functional improvement outcomes than corticosteroids.7,9 Autologous whole blood and PRP have comparable efficacy, and some practices use autologous whole blood instead of PRP due to the decreased pre-procedural processing of patient blood.10,11
Although prior projects have compared pain improvement at certain anatomical sites, more research is needed to compare the generalized effectiveness of these procedure subtypes across all anatomical sites.12–15 This project investigated the effectiveness of percutaneous dry needling, percutaneous needle tenotomy, autologous whole blood injection, and/or prolotherapy for tendinosis treatment at a primary care sports medicine clinic. Primary outcomes included pain improvement and ability to return to prior or desired activity following treatment.
Patients included in the study were 15 years or older and treated for tendinosis at a local sports medicine clinic, from January 1, 2014 through April 17, 2019. Eligible patients had at least one of the following 1) percutaneous dry needling, 2) percutaneous needle tenotomy, 3) autologous whole blood injection, and/or 4) prolotherapy. Patients unable to adhere to the post-procedural therapy regimen due to physical disabilities outside of the injury of interest were excluded from the study.
Multiple variables were abstracted from patient medical records to conduct this study. The primary outcomes 1) percent of pain reduction, 2) percent of functional improvement, and 3) the time required (i.e., weeks) to return to prior or desired activity following treatment. Other variables included tendinosis site, patient demographics (e.g., age, gender), competitive or recreational athlete status, adherence to post-procedural therapy regimen, comorbid conditions (e.g., diabetes mellitus, heart failure), and tobacco/nicotine usage. Procedure variables included utilization of prolotherapy, autologous whole blood, percutaneous needle tenotomy, or percutaneous dry needling, length and gauge of needle used, and total procedural fenestration count.
This study was approved by the Human Subjects Committee at the University of Kansas School of Medicine-Wichita and the Institutional Review Board at Ascension Via Christi. All patients meeting inclusion criteria were identified by clinical staff using CPT® codes for ultrasound guided needle placement (76942) and other relevant codes (20552, 20553, 27605, 27306, 27307, 27000, 24357, 28008, 27306). Patient name, medical record number, date of birth, and dates of relevant patient encounters were provided to identify patients whose data would be abstracted. Study data were managed using Research Electronic Data Capture (REDCap®) electronic data capture tools hosted by the University of Kansas Medical Center.12
Data were analyzed using SAS version 9.4 (SAS Institute, Cary, NC). Frequencies, proportions, means, and standard deviations were generated. For testing the associations between two nominal or categorical variables in contingency tables, either Pearson's chi-square results (when the expected frequency is five or more in cells) or likelihood ratio chi-square results (when the expected frequency is less than five in some cells) were reported. On the other hand, Fisher's exact test results were reported to test the associations between two nominal or categorical variables for 2*2 crosstabs. Prior to data analysis, Shapiro-Wilks was used to test the normality distribution of outcome variables. A multiple logistic regression model was conducted to test the association between ability to return to activity, needle length, needle gauge, fenestration count, age, procedure type, gender, and if the patient was an athlete or not. In addition, nonparametric ANOVA (to compare groups without adjusting for confounding variables) and ANCOVA (to compare groups while adjusting for confounding variables) tested differences between procedure types for functional change after controlling for needle length, needle gauge, fenestration count, age, gender, and if the patient was an athlete or not. The rank transform approach to nonparametric methods was used as a combination of PROC RANK and PROC GLM in SAS. Several longstanding nonparametric tests including Kruskal-Wallis are either exactly equivalent to rank transform tests or are nearly equivalent to them (https://www.lexjansen.com/wuss/2009/anl/ANL-Hobbs.pdf). Nonparametric ANCOVA was conducted to test group differences while controlling for confounding factors in cases with the assumption of no interaction between groups and confounding factors. The Wilcoxon test was used for the marginal models to test differences between procedure types for pain change and function change. All statistical tests at p ≤ 0.05 were considered significant.
A total of 680 patients met the requirements of the initial CPT code query; of these, 343 patients met inclusion criteria. Most patients were female (64.7%, n = 222), did not have diabetes (96.5%, n = 331), and had a mean age of 36 years (SD = 16.7).
The total number of unique procedures was 598. Dry needling represented 62.8% (n = 375) of all procedures, followed by autologous whole blood injections (30.3%, n = 181), prolotherapy (5.0%, n = 30), and needle tenotomy (1.8%, n = 11). The mean fenestration count per procedure was 44.7 (SD = 25.8). For those undergoing autologous whole blood injections or prolotherapy, the mean injectate amount was 14.83 mL (SD = 8.86). Most procedures were performed on nonsmokers (86.9%, n = 520) and non-competitive athletes (65.0%, n = 388).
Most procedures that had follow-up visits (61.3%, n = 367) resulted in the patient reporting their most recent treatment was associated with diminished pain (73.0%, n = 268); 16.6% (n = 61) reported no change, 1.3% (n = 5) reported increased pain, and 9.0% (n = 33) did not have a response recorded. Amongst those who had a follow-up after prolotherapy, 81.0% (n = 17) reported diminished pain and 19.0% (n = 4) did not have a response recorded. Amongst those who had a follow-up after autologous whole blood injections, 79.6% (n = 113) reported diminished pain, 0.7% (n = 1) reported increased pain, 15.5% (n = 22) reported no change, and 4.2% (n = 6) did not have a response recorded. Amongst those who had a follow-up after needle tenotomy, 42.9% (n = 3) reported diminished pain, 42.9% (n = 3) reported no change, and 14.3% (n = 1) did not have a response recorded. Amongst those who had a follow-up after dry needling, 68.5% (n = 135) reported diminished pain, 2.0% (n = 4) reported increased pain, 18.3% (n = 36) reported no change, and 11.2% (n = 22) did not have a response recorded.
Of those who reported diminished pain amongst all procedures, 51.9% (n = 139) reported a percentage of pain improvement and 3.7% (n = 10) reported improvement in functionality. The mean decrease in pain was 63.0% (SD = 27.11). The mean increase in functionality was 57.5% (SD = 32.43).
Most patients were able to return to activity by follow-up (47.4%, n = 172), with 9.1% (n = 33) having not yet returned to activity and 43.5% (n = 158) without a response documented. Of those who returned to activity, the time to return was documented for 26.9% (n = 46) with a mean return to activity of five weeks (SD = 2.43). Amongst procedure types, those that underwent autologous whole blood injection had the highest proportion able to return to activity (60.7%, n = 85), with 7.86% (n = 11) having not yet returned to activity and 31.4% (n = 44) without a status documented. Of those that underwent dry needling, 40.5% (n = 79) had returned to activity, 10.7% (n = 11) had not yet returned to activity, and 48.7% (n = 95) did not have a status documented. Of those that underwent prolotherapy, 38.1% (n = 8) had returned to activity, 4.8% (n = 1) had not yet returned to activity, and 57.1% (n = 12) did not have a status documented. Of those that underwent needle tenotomy, 100% (n = 7) did not have a status documented. Amongst those who commented on adherence to post-procedural therapy regimen at follow-up (63.2%, n = 232), 85.8% (n = 199) were compliant, 11.2% (n = 26) were semi-compliant, and 3.0% (n = 7) were noncompliant.
This study was unique in that it investigated the effectiveness of tendon fenestration and injection procedures for treatment of tendinosis treated at a sports medicine clinic. Prior studies investigated their use at specific anatomic locations.12–15 As 73% of patients reported their most recent treatment was associated with diminished pain, this study suggested that ultrasound-guided tendon fenestration and injection procedures can be effective at diminishing pain caused by tendinosis with a low likelihood of worsening patient pain. This was particularly common among patients with prolotherapy or autologous whole blood injections, 81.0% and 79.6% of whom reported diminished pain, respectively. This was consistent with previous studies of specific anatomic locations.12–15 Utilization of standardized pain measurement scales, such as the visual analog scale, during documentation would allow future studies to compare response to treatment amongst procedure types. While this study lacked long-term follow-up data, clinic physicians’ discussions with patients led them to believe there may be benefit up to a year after these procedures, especially if post-procedural therapy regimens are continued during this time.
This study suggested that ultrasound-guided tendon fenestration and injection procedures, particularly autologous whole blood injection, were effective at allowing patients to return to activity by follow-up; however, inconsistent documentation of return to activity status in this study warranted further investigation on this topic.
Once conservative management failed, no practice guidelines existed for determining when it is appropriate to use percutaneous dry needling, needle tenotomy, autologous whole blood injection, or prolotherapy. Providers at the clinic in which the study was conducted would recommend these procedures based on a patient’s history of failed conservative management, evidence of calcification demonstrated on ultrasound, and timeline for recovery (e.g., “in-season” for competitive athletes). Patient variables such as degree of pain, function loss, and religious beliefs against the use of blood products also were considered before a physician recommended a specific procedure. These factors led to small sample sizes for those undergoing prolotherapy and needle tenotomy and limited bivariate and multivariate analyses of patient and procedure variables.
Based on these findings, future research should investigate the cause of loss to follow up and response to treatment of those undergoing these procedures. Contributing to this problem, patients at the sports medicine clinic at which the study was conducted were instructed that they did not need a follow-up if their symptoms were resolved after some of the procedures. Other known reasons for loss to follow up included patients following up with the orthopedic specialist that referred them to the clinic, or being a member of a local sports team that was covered already by the clinic physicians and having their response to treatment observed but undocumented.
Regarding those referred by orthopedic specialists, a future study of interest would be to investigate the proportion of patients that avoided surgical intervention. Surgery commonly is reserved for cases of tendinosis that have failed minimally invasive interventional procedures.2,8 Surgery for tendinosis focuses on reestablishing tendon vascularity and excision of fibrotic adhesions and areas of failed healing.13 Surgical interventions for tendinosis require a period of 4 to 12 months before patients can return to activities, depending on the tendon repaired.14,16–17 Other areas of interest for future studies include investigating response to treatment by pre-procedural pain severity and time elapsed from symptoms onset to undergoing a procedure.
Most patients who underwent a tendon fenestration or injection procedure reported diminished pain and a return to activities at follow-up. Autologous whole blood injection may have a better likelihood of decreasing patient pain and allowing patients to return to activity by follow-up than dry needling, prolotherapy, or needle tenotomy.