Table 2.
Overview of registered complications
| During treatment | Within 1 year after treatment | Between 1 and 2 years after treatment | |
| n (%) | n (%) | n (%) | |
| Pin tract infection—action: | 43 (66) | 1 (2) | – |
| Oral antibiotics | 38 (59) | 1 (2) | – |
| Hospitalisation and/or intravenous antibiotics | 2 (3) | – | – |
| Wound cleaning at day care | 1 (2) | – | – |
| Day care without follow-up needed | 1 (2) | – | – |
| Undefined | 1 (2) | – | |
| Pain/discomfort treated knee—action: | 9 (14) | 2 (3) | |
| Pain medication | 2 (3) | – | |
| No action | 7 (11) | 2 (3) | |
| Flexion limitation | – | 2 (3) | – |
| Pain/discomfort elsewhere | 3 (5) | 1 (2) | 2 (3) |
| Contralateral knee | – | – | 2 (3) |
| Back and bladder | 1 (2) | – | – |
| Other | 1 (2) | 1 (2) | – |
| Cardiovascular | 2 (3) | – | – |
| Thrombosis with additional anticlotting | 1 (2) | - | – |
| Suspected vain complications+pain medication | 1 (2) | – | – |
| Defect tibia cortex | – | 1 (2) | – |
| Device related | 8 (12) | ||
| Distraction distance deviation | 4 (6) | ||
| Loose bone pin(s) | 1 (2) | ||
| Broken bone pin(s) | 1 (2) | ||
| Device repositioned | 1 (2) | ||
| Device failure | 1 (2) |
Complications are shown within the first 2 years of follow-up in seven categories during treatment, after treatment until 1-year follow-up, and between the first and second year of follow-up. The number and percentage of patients are given. Bolt numbers represent the total complications per category. Detailed explanation of device related complications: (1) Deviation of the initially set amount of distraction (5 mm) was reported for four cases; distraction was restored for the remaining treatment period. (2) Remarkable loosening of bone pins in the bones was reported for one patient. From oral communications with involved surgeons, it appeared that reduced bone pin fixation at removal after 6 weeks treatment was observed regularly, which was considered inevitable aspect of the surgical technique. (3) Broken bone pins were observed in one case halfway the distraction period (at 3 weeks); the distraction device was subsequently removed and KD treatment was not completed. The pin fragments did not protrude from the outer cortex and were kept in place. (4) Device failure consisted of a broken tube, discovered at frame removal and not affecting treatment.