Single- vs 2-Screw Lag Fixation of the Medial Malleolus in Unstable Ankle Fractures

Foot Ankle Int. 2019 Jul;40(7):790-796. doi: 10.1177/1071100719840995. Epub 2019 Apr 11.


Background: The purpose of this study was to determine the efficacy of medial malleolar fixation with 1 vs 2 screws.

Methods: Between April 2013 and February 2017, 196 patients who presented at 2 hospitals within one academic institution with an unstable rotational ankle fracture with a medial fracture and were treated operatively by a trained orthopedic surgeon were identified. These patients' charts were reviewed and their injury, radiographic, surgical, and follow-up data recorded. Medial malleolus fragment size was assessed on the anteroposterior (AP) and lateral views of the initial injury radiograph. Functional outcome was assessed using Maryland Foot Score (MFS). Patients were grouped based upon the number of screws utilized to fox the medial malleolar fragment. Data were assessed using Fisher exact tests and independent t tests with SPSS, version 23.

Results: Out of the 196 patients who met inclusion criteria, 47 patients (24%) were fixed with 1 medial malleolar screw and 149 patients (76%) were fixed with 2 screws. There were no differences among patients who received 1 vs 2 screws with regard to age, gender, body mass index, American Society of Anesthesiologists grade, or smoking status. The average malleolar fragment size was smaller in those treated with 1 screw on both the AP and lateral radiographic views than those with 2 screws (P = .009, P = .001, respectively). There was no difference between groups in ankle dorsiflexion or plantarflexion at 1 year postoperation (P = .451, P = .581). Patients who received 1 screw did not differ from those who received 2 screws with respect to Maryland Foot Scores (P = .924). There was no difference in rate of revision surgery or need for hardware removal between groups (P = .093). Furthermore, time to healing and postoperative complication rate did not differ between groups.

Conclusion: The use of a single screw for medial malleolar fixation provided stable fixation to allow ankle fracture healing, without an increase in complications. This information is especially important in situations when the fragment is too small to accommodate multiple fixation points.

Level of evidence: Level III, retrospective case-control study.

Keywords: ankle fracture; medial malleolus; screw fixation.

MeSH terms

  • Adult
  • Aged
  • Ankle Fractures / diagnostic imaging
  • Ankle Fractures / surgery*
  • Bone Screws*
  • Case-Control Studies
  • Female
  • Fracture Fixation, Internal / methods*
  • Fracture Healing
  • Humans
  • Male
  • Middle Aged
  • Radiography
  • Retrospective Studies
  • Surveys and Questionnaires