Lateral epicondylitis, also known as “tennis elbow,” is a degenerative condition involving injury to the extensor carpi radialis brevis (ECRB) and occasionally, the extensor digitorum communis muscle (EDC). “Many etiologies have been proposed, including overexertion or sudden forceful extension. Ultimately, it is the accumulation of micro tears between the tendon origin of ECRB and the periosteum of the lateral epicondyle that leads to the clinical signs and symptoms (Ford, Schmitt, Lineberry, & Luce, 2015, p. 285-286). ”
Histological analysis shows that epicondylitis is not so much an acute inflammatory process but chronic elbow tendinosis, as very few inflammatory cells have been found on surgical pathology specimens (Ford et al. , 2015). Because of this chronic etiology, lateral epicondylitis is often referred to as lateral elbow tendinosis. Once a diagnosis is made, “initial treatment usually consists of activity modification, counter force bracing, non-steroidal anti-inflammatory drugs (NSAIDSs) if tolerated, and physical therapy (Neeru, 2015, Initial Management section). For most patients this problem is usually self-limiting and tends to resolve with non-operative treatments. However, the problem persists and while they may not be considering surgical intervention, patients are looking for an alternative way with the least possible risk involved in treatment.
“While historically, corticosteroid injections were considered first line therapy for intractable epicondylitis, recent studies suggest corticosteroid injection may be effective only in the short term (6 weeks) according to Ford et al. 2015, p. 286))”, and “will not prevent recurrence and may actually lead to worse long-term outcomes (Neeru, 2015, Glucocorticoids Injections section). ” So, where do we go from here? In recent years, more and more research has been done using autologous platelet-rich plasma (APRP) injections showing significant pain reduction in chronic elbow tendinosis and significantly better long-term outcomes than steroid injections (Ford et al. , 2015). But is that enough to make APRP injections a possible alternative to surgical release?
Studies comparing APRP injections with surgical outcomes are showing more favorable results regarding pain and function in lateral epicondylitis. Discussion/Analysis Ford et al. (2015) explains that, Various injection modalities have been proposed as suitable alternatives to surgical intervention for lateral elbow tendinosis, but randomized trials have shown that the efficacy of steroids is greatest in the acute setting as success rates decrease from 92 to 68% at 6 and 52 weeks, respectively.
Furthermore, steroid injections have been shown to suppress tendon healing and collagen synthesis and are no longer the recommended treatment modality in cases of recalcitrant lateral elbow tendinosis. The reason steroid injections are no longer recommended in chronic elbow tendinosis it’s because of the non-inflammatory nature of the condition. Repeat use of steroid injections can have a negative effect on tendon cells by increasing the chance of necrosis and collagen disorganization at the site, further reducing the tendon’s mechanical properties (Dean et al. , 2013).
This process can result in prolonged tendon injuries and pain. Chou, Liou, Kuan, Huang, & Chen, 2015). So it would seem somewhat counterintuitive. APRP injections on the other hand, have been safely used in various surgical subspecialties like orthopedics, cardiothoracic and maxillofacial surgery. The process involves collecting venous blood from the patient, placing it in a centrifuge and spinning it for five minutes. The resulting concentrated plasma supernatant is collected and injected at the site of pain.
The success of APRP injections is attributed to the release of platelet activating factors that promote faster healing at the site of tendon degeneration. Studies suggest that this healing cascade is initiated by the release of thrombin during the injection process, which activates platelets to release their growth factors (Ford et al. , 2015, p. 290). ” Mishra and Pavelko (2006) evaluated 15 patients who received APRP injections for chronic elbow tendinosis. At eight weeks after treatment, patients noted 60% improvement in pain score, at 6 months 81% improvement and at final follow-up, 12-38 months, patients reported 93% reduction in pain (Mishra & Pavelko, 2006).
The problem with this study, while offering a great outcome in the APRP group, it can be misleading, since 3 of the 5 patients in the control group dropped out of the study at the eight week mark, to pursue alternative treatment for their symptoms. So the study only followed those patients that had received the APRP injections. Similarly, there have also been studies that have refuted the long-term efficacy of APRP injections. Ford et al. (2015) notes, A trial of 60 patients randomized to steroid, APRP, or saline placebo injections howed no significant difference in pain relief at 3-month follow-up between APRP and saline injections.
Although there was a significant reduction in pain with the steroid group at 1 month, no significant reduction was noted at 3 months for either APRP or steroid group compared to placebo. Corticosteroid injection while great in the acute process of lateral epicondylitis, it is slowly being phased out as first line therapy for chronic lateral epicondylitis because of the minimal long-term effect as supported by various studies.
While APRP is still considered experimental treatment it is definitely gaining ground in practice despite mixed trial results. Ford et al. (2015) designed a study to compare the effectiveness of APRP injections to surgical release of the extensor tendon origin outcomes in intractable elbow tendinosis. The study involved 78 patients, split in 28 (APRP group) and 50 (surgical group). The preoperative data analysis showed similar demographics, duration of symptoms, and exam findings between the two groups. All patients had attempted some type of conservative therapy without relief of symptoms.
Also of note, a significantly greater number of patients in the surgical group had received corticosteroid injections in comparison to the APRP group (Ford et al. , 2015). The difference is largely due in part to the fact that patients in the APRP group came in at a time when studies were starting to show the minimal long-term benefit of steroid injections (Ford et al. , 2015). The Ford et al. (2015, p. 291) study concluded that, “following intervention, both groups reported similar pain improvement (89. 3% APRP, 84% surgical) and percent pain reduction (61. % APRP, 55% surgical). ”
In addition, 82% of patients in both groups returned to full work status without restrictions. Of the 78 patients in the study, two patients failed APRP therapy and three patients failed surgical intervention. Statistically, it showed no significant difference in failure rate of either procedure at final follow-up (Ford et al. , 2015). Moreover, while results showed that APRP injections might not be significantly superior to surgical release, it might be a reasonable alternative to surgical intervention (Ford et al. 2015).
And with comparable evidence in pain dissolution, symptom relief, and return to full work status, it’s an option that warrants further thought, especially since APRP injections can reduce the risks involved with surgery, anesthesia, and recovery, just to name a few (Ford et al. , 2015). In addition, while the two treatment groups showed similar demographics and clinical presentation, the study is limited by the small sample size, which in turn limits the study’s predictive ability (Ford et al. , 2015). This study also lacks a control group.
To improve this study’s validity a larger patient sample should be sought and randomized to either APRP injections or surgical intervention, and a control group (Ford et al. , 2015). Follow-up should also be closely monitored at 3, 6, 12, 24, and 36 months as lateral epicondylitis follows a chronic course and patients may exhibit some degree of discomfort or limitation in the long-term. Conclusion In summary, as lateral epicondylitis continues to affect an increasingly large population annually, it’s important for physicians to stay up to date with available treatment options, especially if conservative measures fail to resolve symptoms.
With studies showing a minimal long-term benefit of corticosteroid injections in chronic lateral epicondylitis, and APRP injections showing comparable results to surgical intervention, patients can now have an alternative to surgery for relieving their symptoms. This rings especially true for patients that may be poor surgical candidates, need to return to work sooner, or are afraid to have surgery because of surgical complications.
As a first line therapy, PRP injections may be a suitable alternative to promote activation of tendon healing, remodeling, and ultimately, recovery (Ford et al. , 2015). ” Despite the study’s great results, further research and clinical trials should be conducted to further assess the validity of the APRP injections versus surgical release in chronic lateral epicondylitis. Also, a long-term investigation should be done on patients who’ve received APRP injections to evaluate for any side effects if any or complete resolution of symptoms caused by lateral epicondylitis.
