Joost Peerbooms

92 Chapter 6 ( P = .455). However, when DASH scores were compared at each assessment point separately, the PRP group scored significantly worse at baseline and at 4 weeks after the injection ( P < .005), while the opposite was found at 26 weeks ( P =.037), 52 weeks ( P < .0001), and 104 weeks ( P < .0001) after treatment. In general, the results of the intention-to-treat analysis and the as-treated analysis were comparable (Figure 3B). However, when the baseline scores of the corticosteroid group were compared with the 2-year results in the as-treated analysis, no significant difference was found ( P = .438), indicating that the corticosteroid group returned back to baseline levels. In addition, the deterioration in the corticosteroid group between baseline and 4 weeks disappeared. Successful Treatment (DASH Symptom Score) In total, 56 of 100 patients (56.0%) were successfully treated, which was defined as a reduction of 25% on the DASH score without a reintervention after 2 years. Patients in the PRP group were more often treated successfully (n = 37; P < .0001) compared with the corticosteroid group (n = 19). However, compared with baseline DASH scores, a number of patients (n = 30) had deteriorated at 2-year follow-up. The majority of patients in this group received a corticosteroid injection (n = 23), while 7 patients received a PRP injection ( P = .001). Eventually, 1 patient received a reinjection, 1 patient crossed over to the PRP group, and 4 patients received surgery. Failures (Reinterventions) Table 4 shows the characteristics of the 20 reinterventions. On average, reinterventions or operations were needed after an average of 6 months (range, 2-14 months). At baseline, 14 patients were allocated to corticosteroids and 6 patients received an injection with PRP ( P =. 036). The protocol-compliant group and the reintervention group differed significantly regarding sex ( P = .015) and side ( P = .027). There were 6 reinterventions in the PRP group: 3 patients who required an operation and 3 patients who required a reinjection with corticosteroids. Except for 1 reinjection, all reinterventions were performed in the first year after the initial treatment; 2 operations and 1 reinjection with corticosteroids occurred within 3 months after the PRP injection. There were 14 reinterventions in the corticosteroid group: 6 patients required an operation, 1 patient required a reinjection with corticosteroids every 3 months and declined surgery, and 7 patients crossed over to have a PRP injection. In the corticosteroid group, all reinterventions were performed in the first year of follow-up except for 1 crossover patient receiving a PRP injection. Regarding the patients who failed their initial treatment, those who crossed over to the PRP group significantly improved on both VAS pain scores ( P < .001) and DASH disability symptom scores ( P = .019). 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. No complications were seen concerning the use of PRP, except for the