Radiographic Healing of Far Cortical Locking Constructs in Distal Femur Fractures: A Comparative Study With Standard Locking Plates.

OBJECTIVES

To investigate the radiographic healing of far cortical locking (FCL) construct fixation in distal femur fractures compared with traditional locking plate (LP) constructs.

DESIGN

A retrospective cohort of 143 consecutive patients with 146 distal femur fractures.

SETTING

Level I trauma center.

PATIENTS/PARTICIPANTS: After excluding patients with OTA/AO type B fractures, referred nonunion cases, patients younger than 16 years, and patients with less than 24 weeks of follow-up, 69 patients with 70 total fractures were included for analysis.

INTERVENTION

AP and lateral knee radiographs were blinded to type of screws and individually reviewed by 3 orthopaedic trauma surgeons.

OUTCOME MEASUREMENTS

The modified RUST (mRUST) score was our primary outcome measure. mRUST scores were assigned at 6, 12, and 24 weeks and final follow-up based on AP and lateral radiographs and compared between FCL and LP groups as a tool for evaluating fracture healing. Secondary outcomes compared between FCL and LP included union rate and postoperative complications.

RESULTS

Statistically significant differences in mRUST scores were noted between FCL and LP groups at 6 weeks (P = 0.040), 12 weeks (P = 0.034), 24 weeks (0.044), and final follow-up (P = 0.048). There was no significant difference in union or specific complication rates between the 2 groups. The union rate was 90.5% and 82.1% for the FCL and LP groups, respectively, at final follow-up.

CONCLUSIONS

To our knowledge, this is the first comparative study between FCL and LP constructs. The FCL group was noted to have significantly higher mRUST scores at all periods indicating increased callus formation, but the differences seen were small and there were no differences in healing rates or complications between the 2 groups, thus bringing the clinical benefit of FCL into question. Further prospective study designs are needed to compare FCL with LP constructs and to investigate the role of interfragmentary motion on callus formation in distal femur fractures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.