Outcomes for an Alternative Technique of In Situ Screw Fixation for Garden I and II Femoral Neck Fractures.

OBJECTIVES

To assess whether a fully threaded (FT) inferior positioning screw in screw fixation of geriatric femoral neck fractures had lower varus collapse and failure than an all partially threaded (PT) screw construct.

DESIGN

Single institution retrospective cohort study.

SETTING

Level II trauma center, community hospital health system.

PATIENT SELECTION CRITERIA: Included were all patients of age 50 years and older treated with in situ inverted triangular screw fixation with an FT inferior screw for Garden I and II femoral neck fractures (Orthopedic Trauma Association/AO Foundation 31B1.1, 31B1.2, and 31B2.1) from 2015 to 2021, age and sex matched 2:1 with an all PT screw group identified from the same period.

INTERVENTION: In situ screw fixation with an FT inferior positioning screw.

OUTCOME MEASURES AND COMPARISONS: Reoperation rates and radiographic outcomes were compared between the FT and PT constructs.

RESULTS

Twenty-four patients were treated with an FT inferior screw [67% female, mean age 80.0 years (58-97)] and matched with 48 patients with an all PT construct [67% female, mean age 79.3 years (56-99)]. There were no differences in age ( P = 0.89) or sex ( P = 1.0). In the FT group, 1 patient (4.2%) required revision surgery versus 11 (22.9%) in the PT group ( P = 0.03). Multivariate analysis demonstrated a protective effect of the FT construct, when controlling for trained traumatologist, Garden classification, and time to operating room > 24 hours [operating room (95% confidence interval), P -value] [0.08 (0.006-0.91), P = 0.04]. Seven patients (58%) required revision because of femoral neck shortening and varus collapse. The lone FT reoperation was because of persistent nonunion without collapse (4.2%). There was no varus collapse in the FT group at final follow-up.

CONCLUSIONS

This study found a lower reoperation rate because of varus collapse in patients with femoral neck fracture treated with an inferior FT screw. With an inferior FT screw, no case of varus displacement or collapse was observed and the only revision was because of a fracture nonunion without collapse.

LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.