|Abstract / Summary
Twenty years ago, the established treatment for bone lengthening was external fixation, which had the major disadvantages of high complication rates and patient discomfort. Since then, the externally controlled bone lengthening nail was introduced to reduce complications and improve patient comfort. More than 14,000 FITBONE and PRECICE bone lengthening nails have been implanted worldwide and have become many reconstructive surgeons’ first choice for lower limb lengthening. However, established evidence concerning the complications of bone lengthening nails remains lacking in the published literature, which mostly consists of small retrospective cohort studies without consistent complication reporting. Complications related to the use of externally controlled bone lengthening nails were, therefore, the primary aim of this Ph.D. investigation. The frequency of complications combined with their origin and severity was mapped. Patient- and surgery-related risk factors of the complications were also investigated.
First, the body of literature was explored through a systematic review, which assembled a group of 983 segments. Device, bone, and joint complications were the most frequent complication origins, and the overall frequency of complications was one complication for every three segments lengthened. Most complications occurred in the distraction and consolidation stage prior to implant removal.
A retrospective two-center cohort study of 314 segments provided the basis for the second study, showing a complication frequency of one complication for every two segments lengthened. While most complications occurred in the distraction and consolidation stage prior to implant removal, a surprisingly high number of complications was observed after nail removal. Similar to the review study (Study I), device, joint, and bone were the three most frequent origins of complication. The following risk factors with a significant increased relative risk of complication were discovered: age groups ≥20 years, FITBONE nail, tibia segment, acute deformity correction combined with lengthening, and increasing bone lengthening.
In the last study, the intra- and inter-rater reproducibility of the complication severity and origin classification system was evaluated. A good inter-rater and good to excellent intra-rater agreement for the severity and origin classification was found in the two examined case groups.
In short, the thesis presents evidence on the frequency, origin, and severity of complications in bone lengthening nails. The results of this thesis suggest that complications in the treatment of bone lengthening nails frequently occur and that risk factors of complications exist; both implications provide valuable knowledge in the assessment and the treatment of bone lengthening patients.