Joost Peerbooms

96 Chapter 6 have peaked and can be expected to subsequently decline. However, at this time no true indication of what the result of second injection would be can be determined. Routinely injecting a second time would be unnecessary in 73% of the cases, as they were already successful after 1 injection. Regarding the patients who failed their initial treatment, those who crossed over to the PRP group significantly improved on both VAS pain scores and DASH disability symptom scores. The decision to proceed to further treatment was based on patient preference. However, patients who received surgery or a reinjection with corticosteroids did not benefit when their VAS and DASH scores at 2 years were compared with their baseline scores. When interpreting these results, strong conclusions regarding these findings are not possible, because the numbers of patients in these reintervention groups were relatively small. We know that the natural history of nonchronic lateral epicondylitis is benign, resulting in normalization of complaints in the vast majority of patients within 1 year with little gain in recovery between 6 and 12 months. 27 All patients included in this study had complaints for at least 6 months. Patients receiving a corticosteroid injection also have a natural history and because the population was randomized, we can expect that the natural history will have the same influence in both groups. In the current study, 70% of the patients were already injected with corticosteroids at least 6 months before inclusion into this study. The PRP group should have experienced this negative effect also. Whether the positive effect of PRP is in fact the natural course of lateral epicondylitis cannot be determined from the current work. Still, the inclusion of patients with a minimum complaint history of 6 months indicates a chronic patient population was enrolled in the study. The positive effect of PRP compared with a corticosteroid injection on the course of lateral epicondylitis thus seems not be caused by natural history or a negative effect of the corticosteroid injection (which is not present in this study [Figures 2 and 3]). A critique of the original study was that the corticosteroid treatment is not the same as a placebo and might be worse than a placebo. In the Netherlands, the Institutional Review Board would not allow a placebo, and therefore this is a limitation of this study as the corticosteroid injection (and those before inclusion in the study) may have adversely affected the long-term results compared with a true placebo injection or dry needling. In the Netherlands, a PRP treatment costs approximately twice as much as a corticosteroid treatment and surgery for lateral epicondylitis is twice the cost of a PRP treatment and thus 4 times as much as a corticosteroid injection. The PRP treatment therefore costs 2 units; a steroid injection costs 1 unit and surgery, 4 units. Thus, in the PRP group 51 patients were treated with PRP, costing 51 times 2 units of money, and in the corticosteroid group, 49 patients were treated, costing 49 times 1 unit. In this study we had 20 reinterventions: 3 surgeries (12 units) and 3 reinjections with corticosteroids (3 units), making a total of 6 reinterventions, costing 15 extra units in the PRP group; and 6 surgeries (24 units), 1 reinjection with corticosteroids (1 unit),