Do displacement thresholds matter? Outcomes of non-operative treatment in metatarsal II-IV fractures

Fractures of the central metatarsals II-IV are classified as displaced or non-displaced according to radiographic criteria, namely angulation and translational displacement, which often guide decisions regarding operative versus non-operative management.

This retrospective cohort study included 57 patients with 90 fractures of metatarsals II-IV treated non-operatively at a trauma centre. Fractures were classified as displaced if angulation exceeded 10° and/or translational displacement or shortening exceeded 3 mm. Radiographic healing was assessed at 6 weeks, 3 months, and 6 months using the radiographic union score for tibial fractures (RUST), pragmatically adapted for central metatarsals. Clinical outcomes included pain and analgesic use. Patient-reported outcome measures (PROMs) were assessed.

Twenty-two patients (38.6%) were assigned to the displaced fracture group, while 35 patients (61.4%) formed the non-displaced group. Radiographic healing progressed consistently over time, with no significant differences between displaced and non-displaced fractures at any follow-up interval. Neither angulation >10° nor translational displacement or shortening >3 mm was associated with delayed union or inferior radiographic healing. Pain and analgesic use decreased over time and did not differ significantly between groups. PROMs demonstrated a high symptom burden in the acute phase; however, fracture displacement was not associated with worse functional limitation, pain, or health-related quality of life.

Non-operative treatment of metatarsal II-IV fractures, exceeding commonly cited radiographic displacement thresholds, results in radiographic healing and favourable clinical and patient-reported outcomes. These findings question the routine indications for operative fixation and support a more individualized, outcome-oriented treatment approach.