SLR - April 2022 - Kushkaran Kaur
Reference: Morimoto S, Iseki T, Morooka T, Yoshiya S, Tachibana T, Tanaka J. The Effectiveness of Intramedullary Screw Fixation Using the Herbert Screw for Fifth Metatarsal Stress Fractures in High-level Athletes. Am J Sports Med. 2021 Dec;49(14):4001-4007.Level of Evidence: IV
Scientific Literature Review
Reviewed By: Kushkaran Kaur, DPM
Residency Program: Temple University Hospital, Philadelphia, PA
Podiatric Relevance: Fifth metatarsal fractures are often treated operatively with intramedullary screw fixation in athletes. Conservative treatment can lead to complications such as delayed or non-union and refracture. Fixation can consist of different types of screws including solid screw, cannulated cancellous screw and headless compression screws. The Herbert screw is a headless screw that provides advantages of absence of irritation due to the lack of head and easier insertion due to the use of a K-wire guide. A disadvantage of screw fixation includes the plantar gap due to the curved metatarsal medullary canal. This study assesses surgical prognostic factors and intraoperative plantar gap widening for intramedullary Herbert screw fixation for fifth metatarsal stress fractures in high-level athletes.
Methods: Thirty-nine high-level athletes with intramedullary screw fixation using the Herbert screw for fifth metatarsal stress fractures from August 2005-August 2017. Exclusion criteria consisted of patients with post-operative follow-up period of <2 years. Outcome measures included time to obtain bone union, time to return to sport, and treatment failures/complications. For intraoperative plantar gap widening, two groups were formed: patients with plantar gap widening of less than 1 millimeter and those with greater than or equal to 1mm. Patients were non-weightbearing for two weeks, followed by full weightbearing at four weeks. They were back to running once partial union was confirmed on radiographs and full activity once completely unionized and without clinical tenderness.
Results: No delayed union, non-union, or refracture was seen in either of the two groups. Sixteen patients were in the no-gap group and 21 patients in the gap group. No statistically significant differences were noted in terms of demographics. The mean plantar gap widening intraoperatively was 0.69 +/- 0.19 millimeters and 2.37 +/- 0.57 millimeters for the non-gap vs gap groups, respectively. No statistically significant differences were seen in mean times to bone union and return to sport, between the two groups.
Conclusions: Intramedullary screw fixation is often used for fifth metatarsal fracture fixation due to preservation of much of the blood supply and less hardware irritation compared to other methods of fixation. Intraoperative plantar widening with the use of intramedullary screw fixation for fifth metatarsal fractures has been of concern for surgeons. The present study shows that although there may be widening in the plantar gap intraoperatively, there is no statistical significance or correlation in terms of fracture union time or time to return to activity. Furthermore all athletes in the study were able to return to the original sport without complications or treatment failures. Previous studies do not focus on the effect of plantar gap widening on the clinical results of intramedullary screw fixation, using the Herbert screw, a headless cannulated screw. The study provides valuable information on surgical fixation for fifth metatarsal fractures. However, it does have some limitations including lack of comparison of different fixation types and methods, small sample-size, and short follow-up time.