Functional Outcomes Following Operative Treatment of Tibial Tubercle Fractures

Abstract

Background: Quantitative evaluation of the functional results of surgically managed tibial tubercle fractures in adolescents is unreported in the orthopaedic literature.

Methods: All patients treated surgically for unilateral tibial tubercle fractures at a single institution from 2007 to 2011 were invited to return for functional evaluation. Fractures were classified using the Ogden classification system. Clinical examination at follow-up included passive knee range of motion and thigh circumference. Side-to-side knee extension strength deficits were evaluated using a Biodex dynamometer. Patient-reported outcomes were assessed using the Pediatric-International Knee Documentation Committee Subjective Knee Form (Pedi-IKDC), Tegner-Lysholm Knee Scoring Scale, and Visual Analog Pain Scale. Chart review was performed to determine postoperative protocols including the use of physical therapy and protected weight bearing. Functional parameters were compared between the involved and uninvolved extremities using the Wilcoxon Signed Ranks Test and the Spearman correlations were performed to identify any relationships between perioperative factors, functional parameters, and subjective outcomes.

Results: In total, 19 of 42 patients completed clinical and functional testing and 18 of 19 completed all outcome surveys. Average age at injury was 13.9 years and average follow-up was 3.0 years. There was no statistical difference in knee range of motion between sides, however, thigh circumference was slightly smaller in the injured extremity (median difference, 1.7 cm at 15 cm above the patella and 4.0 cm at 50% of the length of the thigh). In total 5/19 subjects (26%) had a significant quadriceps extension strength deficit on the involved leg compared with the contralateral side. The median Visual Analog Pain Scale for affected limbs was 8/100 and for unaffected limbs was 6/100 (P=0.017). The Tegner-Lysholm Scale revealed 9 excellent results, 5 good, 4 fair, and 1 poor (median, 90/100). Results of the Pedi-IKDC were 11 excellent, 3 good, 2 fair, and 3 poor results (median, 91/100). Outcome scores did not correlate to diminished strength or thigh circumference. No difference in outcome based upon body mass index, postoperative weight-bearing status, Ogden classification, or postoperative physical therapy was noted using regression analysis.

Conclusions: Despite promising objective results, clinical outcomes measured by subjective validated surveys are not all excellent.

Level of evidence: Level III.