Mini Fragment T-Plate Fixation for Medial Malleolar Fractures Achieves Comparable Outcomes to Small Fragment Screw Fixation Without Increased Complication Risk.

Abstract

Objectives: To compare clinical outcomes between mini fragment T-plate (MFTP) fixation and traditional small fragment screw (SFS) fixation for medial malleolar ankle fractures, with a focus on complication rates and fracture patterns.

Methods: Design: Retrospective comparative cohort study.

Setting: Single academic level I trauma center.

Patient selection criteria: Inclusion criteria: age ≥18 years, OTA/AO type 44 medial malleolar fractures treated with either MFTP (2.0 or 2.4 mm) or SFS (3.5 bicortical or 4.0mm partially threaded) from November 2016 to August 2023, and minimum 6-month radiographic and clinical follow-up. Exclusion criteria: prior ipsilateral ankle surgery, vertical fractures not amendable to screw fixation alone.

Intervention: Medial malleolar fracture fixation with one of the aforementioned constructs.Outcome Measures and Comparisons: Primary outcomes compared between MFTP and SFS groups included infection rates, nonunion rates, and reoperation rates. Secondary outcomes included fracture pattern analysis and time to weight bearing. Statistical analysis used chi-square or Fisher's exact test for categorical variables and Student's t-test for continuous variables.

Results: From 194 consecutive patients, 141 met inclusion criteria: 68 MFTP (age 47.1±15.9 years, 72% female) and 73 SFS (age 51.0±17.6 years, 64% female). No significant demographic differences were observed between groups with regards to age (p = 0.168), BMI (p = 0.107), sex (p = 0.393), smoking status (p = 0.556), nor presence of diabetes (p = 0.499). Fracture pattern analysis using the Herscovici classification revealed that low transverse fractures (Type B) were treated with MFTP in 94% of cases vs SFS in 6% (p<0.001), while high transverse fractures showed a more balanced treatment distribution (47% versus 53% SFS versus (p=0.865)). Comparing MFTP with SFS fixation, rates of infection (10.3% vs 8.3% respectively, p=0.777), unplanned reoperation rates (7.0% vs 10.0% respectively, p=0.780), and symptomatic hardware requiring reoperation (4.4% vs 2.7% respectively, p=0.672) were comparable. There was no failure of medial malleolar fixation in either group. One nonunion occurred in the MFTP group and one in the SFS group (p=1.000). Presence of an open fracture in the MFTP and SFS groups was significantly different at 4.4% and 19.4% respectively (p=0.009).

Conclusion: MFTP demonstrated comparable outcomes and complication rates to SFS fixation for medial malleolar ankle fractures. These findings support MFTP as a viable alternative for medial malleolar fixation where fragment morphology may preclude safe dual-screw placement.

Level of clinical evidence: 3, Therapeutic Cohort Study.