Comparing Multipin Clamps With Outriggers With Standard Clamps for Lower Extremity Periarticular External Fixation: Similar Radiographic and Clinical Outcomes

Abstract

Introduction: Staged treatment of high-energy periarticular tibia fractures involves temporization with closed reduction and external fixation, aiming to provide early reduction and stabilization while mitigating soft-tissue complications. Various external fixator configurations exist, including those that use a "multipin" clamp capable of holding multiple pins but limiting pin placement to a single plane. The purpose of this study was to compare clinical and radiographic outcomes and associated costs of standard and multipin outrigger clamp constructs in tibial plateau and pilon fractures treated with temporary external fixation. We hypothesized that use of the multipin clamp may be associated with poorly aligned reductions and increased complication rates.

Methods: A retrospective review of 100 patients with periarticular tibial plateau (AO/OTA: 41B/C) or pilon (43B/C) fracture at a Level 1 trauma center from 2014 to 2023 was conducted. Patient, injury, and complication characteristics were collected. Patients were categorized based on the external fixator clamp used: multipin (MP) or standard (S). Clinical outcomes and complication rates were assessed. Radiographic alignment was evaluated by the change in anterior and lateral distal tibial angles, and sagittal plane translation for pilon fractures, and medial and posterior proximal tibial angles for plateau fractures.

Results: 70 patients underwent standard (25 pilon, 45 plateau) and 30 multipin (10 pilon, 20 plateau) external fixation. MP and S groups showed no notable differences in demographics or injury characteristics. Both groups demonstrated comparable complication rates and radiological alignment outcomes, with no notable differences observed. MP constructs were more costly than standard systems.

Conclusion: In this retrospective study of 100 patients, there was no difference in radiographic or clinical outcomes between the standard frame and multipin frame groups. Typical costs for the multipin frame constructs were $635 to $1249 more than the standard frame constructs.

Figure 1

Images demonstrating the multipin external fixator clamp (top) and standard external fixator clamp (bottom).

Figure 2

Images of the model demonstrating knee-spanning external fixation constructs: (A) multipin and (B) standard.

Figure 3

Images of the model demonstrating ankle-spanning external fixation constructs: (A) multipin and (B) standard.

Figure 4

Radiographs with tibial plateau fracture measurements: (A) medial proximal tibial angle (MPTA) and (B) posterior proximal tibial angle (PPTA).

Figure 5

Radiographs with pilon fracture measurements: (A) lateral distal tibial angle (LDTA); (B) anterior distal tibial angle (ADTA); and (C) sagittal plane translation, reported as a ratio of the length of the anterior talar head to the tibial axis (red line) to the length of the anterior talar head to the posterior talar body (yellow line).