New measure may be useful for assessing healing after tibia fracture
The Functional Index for Intramedullary Nailed Tibial Fractures may provide a standardized approach to the measurement of weight bearing and pain assessment in lower extremity fractures, according to Canadian researchers.
Orthopedics Today Editorial Board member Mohit Bhandari, MD, FRCSC, and colleagues at McMaster University in Hamilton, Ontario evaluated a measure they recently developed, called the Functional Index for Intramedullary Nailed Tibial Fractures (FIX-IT).
The objective with this study was to evaluate the inter-rater reliability and some early construct validity of this particular measure, Bhandari said. Basically, to evaluate content validity we aimed to evaluate whether a few simple criteria for pain and ambulation seemed reasonable with a group of orthopedic trauma surgeons.
The researchers used a nonrandom cross section of 50 adult, ambulatory patients with lower extremity fractures at different healing stages who were recruited from a single Canadian site.
A review panel comprised of orthopedic surgeons, residents and research coordinators independently measured patient function using FIX-IT. The reviewers assessed whether the items of FIX-IT were essential, useful or not needed.
Possible score: 12 points
With FIX-IT, the physician assesses how long patients can stand on one leg (patients fall into one of four categories), their ability to ambulate and their responses to pain and stress.
We stress the tibia for pain as well as directly palpate at the fracture site for pain, Bhandari said. Ultimately, the weightbearing and pain scores are totaled to a maximum possible score of 12 points. Higher scores suggested better overall function and less pain.
The researchers correlated the results between the FIX-IT and the SF-36.
Overall, 80% of the surgeon reviewers felt the FIX-IT measure had adequate face validity. So what we were trying to capture in principal, seemed to be reasonable measure of functional outcome, he said. All four criteria or items on the score were considered to be necessary.
The study population had lower SF-36 scores compared to a normal population, which was expected given injury severity. The overall FIX-IT score was 7.97 points, he said.
High inter-rater reliability
The overall inter-rater reliability across groups was 0.879.
Reliability scores across specific groups were relatively well conserved, Bhandari said. Across surgeons, residents and research coordinators, even in this relatively small sample, there was a conservation of what we would consider to be fairly substantial agreement, suggesting that its relatively straightforward test to administer.
The correlations between this new measure and the SF-36 were reasonably high, he said. They ranged from 0.68 to 0.77 for the physical component summary score, 0.681 to 0.758 for the physical function subscale and 0.677 to 0.786 for the role-physical subscale.
We believe that the FIX-IT score demonstrated adequate convergent validity with the SF-36, Bhandari said.
He noted that the study has strengths including the use of multiple raters from different clinical backgrounds to assess the patients. We achieved high inter-rater agreement, Bhandari said. He also noted that the assessment tool is simple.
Nothing particularly novel about the criteria were measuring; its simply the fact that were doing it in a way that [may] provide some standardization in the assessment of clinical healing.
Regarding limitations of the study, Bhandari noted that all of the patients were recruited from one clinic and the researchers do not have the ability to assess the reliability of this measure over time. by Colleen Owens
- Bhandari M. The evaluation of a new measure for assessing healing in lower extremity fractures. Paper # 387. Presented at the 2011 Annual Meeting of the American Academy of Orthopaedic Surgeons. Feb. 15-19. San Diego.
- Mohit Bhandari, MD, FRCSC, can be reached at Department of Surgery, McMaster University, 293 Wellington Street North, Suite 110, Hamilton, ON L8L 8E7, Canada: email: firstname.lastname@example.org.
- Disclosure: Bhandari is a paid consultant for Amgen Co., Eli Lilly, Pfizer, Stryker and Smith & Nephew.