Comparison of time to healing and major complications after surgical fixation of nondisplaced femoral neck stress fractures: A systematic review.

INTRODUCTION: There is no recent literature review comparing outcomes of fixation methods for nondisplaced stress fractures of the femoral neck.

METHODS: A systematic review of the literature on operative fixation of femoral neck stress fractures was performed. Inclusion criteria consisted of diagnosis of nondisplaced femoral neck stress fractures, implants used for fixation, articles in English language or available English translation, all ages, and Level 1-5 evidence, documented time to healing, and incidence of complications. Statistical analysis was performed to compare outcomes.

RESULTS: Eight studies with 13 subjects and 15 fractures undergoing operative fixation were included. Six fracture were compression sided, five were tension sided, and four were complete. Radiographic healing occurred on average at 32.7 ± 36.3 weeks (range 8-121 weeks). Four subjects were noted to have a metabolic disturbance. Six subjects did not participate in vigorous exercise. There were no complications. There was no significant difference in radiographic healing time between: cannulated screws or SHS ± osteotomy (p = 0.21); compression sided, tension sided, or complete fractures (p = 0.41); ages (p = 0.09); sex (p = 0.09) or individuals with or without metabolic disturbances (p = 0.92). There was no difference between use of cannulated screw fixation, SHS + osteotomy, and SHS alone based on the subject's age (p = 0.27) or cannulated screw vs SHS ± osteotomy given subject's age (p = 0.19) or sex (p = 1.0). Time to full weight bearing (FWB) did not significantly differ between implants (p = 0.22). However, >8 weeks restricted weight bearing had increased healing times (p = 0.002).

DISCUSSION: Time to healing was not dependent on subjects' sex or age, fracture location, implant choice, or presence of metabolic abnormality. No complications were reported. Time to full weight bearing was not dependent on implant choice. However, restricted weight bearing beyond 8 weeks can lead to prolonged healing times. Fixation should be safe, effective and promote early weight bearing and mobilization.