Outcome of Segmental Tibial Defects Treated by Distraction Osteogenesis with the help of Naseer Awais (NA) External Fixator

Abstract

Introduction: Bone segment transport leads to new bone formation (distraction osteogenesis). It is a type of bone healing in which regeneration process fills the bone defects. These long bone defects are produced either by bone loss during high energy trauma, sequestrectomy in chronic osteomyelitis or after
excision of bone tumors. There are many external fixators which are designed to achieve the surgical objective of managing bone defects using the principles of distraction osteogenesis.
Objective: The objective of Segmental Tibial defects treated by distraction osteogenesis with the help of Naseer Awais (NA) external fixator.
Methodology: This quasi experimental study was done on forty four patients with tibial defects at department of Orthopedics surgery and Traumatology Mayo Hospital Lahore from May 2010 to June 2013. NA fixator was applied to in all cases and patients were followed up monthly basis and radiographs were assessed to see the bone healing process. Full weight bearing advised after 8-10 weeks according to the bone healing seen in x-rays. After complete healing and consolidation, fixator dynamization was performed for one month then the fixator was removed.
Results: A total of 44 subjects were included in this study with a mean age of 33 ± 4.3 year. Among them forty (90.9%) male and four (9.1%) females had segment transport with NA external fixator, and male and female ratio was 10:1. Out of forty four patients, seven were lost to follow-up. So out of this thirty seven patients, the healing time was 369 ± 56.2 days (median-333).Pin loosening was in nineteen (44.2 %), clamp loosening in ten (23.3%) and pin break in one (2.3%) cases.In four (10.5%) cases knees had to be arthrodesed due to defect in the joint, sixteen (42.1%) cases had flexion in the range of 121-130º, six (15.8%) had flexion <100.
Conclusion: NA external fixator is a useful device for segment transport and hence can be used in future for better outcome of segmental tibial defects treated by distraction osteogenesis.