Joost Peerbooms

97 2-year follow-up of PRP in lateral epicondylitis and 7 reinjections with PRP (14 units), making a total of 14 reinterventions, costing 39 extra units in the corticosteroid group. Regarding cost, PRP is not cost effective compared with corticosteroid on a short-term basis, but if the costs of those patients failing on the corticosteroid injection who proceed to surgery are taken into account, the differences in cost effectiveness will level out (102 + 15 = 117 units in the PRP group versus 49 + 39 = 88 units in the corticosteroid group), especially if the costs for those who failed on corticosteroids were turned into a success by a consecutive PRP injection. This cost analysis does not include all socioeconomic costs of a recurrence, time off work, and the extra efforts reinterventions required from the patient and doctor. Moreover, although it is difficult to draw conclusions from small numbers, those patients who were reinjected with corticosteroids or those who had surgery did not improve compared with baseline, with those who were reinjected with PRP (those who crossed over) showing significant improvement. The crossover patients actually were patients who were offered either an operation or to try the experimental PRP injection; without this offer, an additional 7 patients in the corticosteroid group would have been operated on. Actually, the number of operations in the PRP group might have been less if we had realized that an initial flare-up of inflammation signs (i.e., pain) is to be expected when using PRP. Two operations and 1 reinjection with corticosteroids were carried out within 3 months after the PRP injection, whereas in fact these patients still might have been in their inflammation and healing phase. Taking all these incidents into account, the PRP procedure might actually be a cheaper method in the long run, but a formal cost analysis should be performed. In conclusion, this report demonstrates that a single injection of concentrated autologous platelets improves pain and function more effectively than corticosteroid injection in chronic lateral epicondylitis. These improvements were sustained over a 2-year follow-up time with no reported complications. 6