Objective assessment of docking site consolidation in bone transport: the role of pixel value ratio in predicting healing outcomes.

Abstract

Background: The management of docking site healing in bone transport remains a significant challenge in orthopedic surgery. Traditional assessment methods rely heavily on qualitative radiographic evaluations. This study investigates the utility of pixel value ratio (PVR), an objective quantitative measure, in assessing bone healing at the docking site during bone transport.

Methods: This retrospective study included 47 patients who underwent bone transport for lower limb reconstruction between January 2015 and January 2020. Patients were categorized into bone union (n = 35) and nonunion (n = 12) groups based on docking site outcomes. PVR was calculated using two methods (PVR1 and PVR2) at six time points over 24 months post-docking. Subgroup analyses were performed based on gender, age, and surgical site.

Results: Of 47 patients, 35 achieved bone union and 12 experienced nonunion. Both PVR1 and PVR2 were consistently lower in the union group compared to the nonunion group at all time points (p < 0.001). In the union group, PVR1 ranged from 1.064 ± 0.050 to 1.108 ± 0.062, while PVR2 ranged from 0.926 ± 0.079 to 0.946 ± 0.062. In the nonunion group, PVR1 ranged from 1.204 ± 0.057 to 1.273 ± 0.020, and PVR2 from 1.039 ± 0.060 to 1.148 ± 0.022. Subgroup analyses revealed that males had significantly lower PVR values compared to females, and tibial cases had lower PVR values compared to femoral cases in both union and nonunion groups (p < 0.05). All juvenile patients achieved union, compared to 71.4% of adults (p < 0.01).

Conclusion: PVR demonstrates significant potential as an objective tool for assessing docking site healing in bone transport procedures. The distinct patterns observed between union and nonunion cases provide a foundation for developing clinical guidelines to monitor and predict healing outcomes. Integration of PVR assessment into clinical practice could improve decision-making and optimize treatment protocols in bone transport procedures.