Orthopedics

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Tips & Techniques 

An Alternative Fixation Technique for Small Medial Malleolus Fractures

Derek F. Amanatullah, MD, PhD; Philip R. Wolinsky, MD

Abstract

Drs Amanatullah and Wolinsky are from the Department of Orthopedic Surgery, University of California at Davis, California.

Drs Amanatullah and Wolinsky have no relevant financial relationships to disclose.

Correspondence should be addressed to: Philip R. Wolinsky, MD, Department of Orthopedic Surgery, University of California at Davis, 4860 Y St, Ste 3800, Sacramento, CA 95817 (philip.wolinsky@ucdmc.ucdavis.edu).

Open reduction and internal fixation of the medial malleolus is indicated with nondisplaced fractures in individuals with high-functional demands at the ankle, as well as displaced fractures of the medial malleolus that may result in ankle instability and varus talar tilt.1,2

Multiple techniques have been described for fixation of the medial malleolus. Two parallel 4.0-mm cancellous screws oriented perpendicular to the fracture line providing compression is the gold standard for medial malleolus fixation. However, this technique is only applicable for use in fragments that are large enough to allow placement of 2 screws. Smaller fragments, because of the lack of surface area for fixation, present more of a challenge. They can be stabilized using a 4.0-mm cancellous screw oriented perpendicular to the fracture line to provide compression and a Kirschner wire to provide rotational stabilization. Still smaller fragments, such as those with a sagittal splint in the anterior and posterior colliculus of the medial malleolus, may require 2 K-wires and a tension band.2 Neutralization plating has also been proposed for vertical shear fractures of the medial malleolus.3,4

This article presents an alternative method for medial malleolus fixation. The use of a 2.0 mini-fragment plate has several functions: (1) the plate is small enough that it can be contoured to the medial malleolus fragments without being prominent over the subcutaneous tip of the medial malleolus; and (2) the 2.4-mm cortical screws inserted through the plate use the plate as a washer, which is helpful to avoid further splitting of comminuted fragments and prevent the screw head from penetrating osteopenic medial malleolus fragments.

The patient is placed supine or prone as the fracture pattern indicates on a radiolucent table. A large radiolucent support platform is constructed with blankets to elevate the operative extremity above the well leg, such that high-quality anterior to posterior and lateral fluoroscopic images can be obtained to verify the position of hardware as well as quality of reduction. The location of the fracture line is confirmed by palpation or fluoroscopic examination. An incision is made over the medial malleolus that extends approximately 2 cm proximal to the fracture line and ends just distal to the tip of the medial malleolus. The subcutaneous tissue and medial retinaculum are reflected with skin to reveal the fractured medial malleolus, and the fracture is cleaned of interposing periosteum and loose debris. The displaced fragment is manipulated into position, and K-wires may be used for provisional fixation of the medial malleolus.

Next, a 2.0-mm, 10-hole mini-fragment T-plate is contoured so that the T portion is bent around the distal tip of the medial malleolus and the shaft of the T-plate runs proximally along the medial border of the tibia (Figure 1). The T is also contoured into a cup shape so that it apposes the medial malleolus (Figure 1B). We do not take down the ligaments attached to the medial malleolus to place the plate. Two or three 2.4-mm cortical screws are placed through the distal T part of the plate to obtain distal fixation and 2 or 3 mini-fragment screws are used for proximal fixation (Figures 1E, F). The contoured mini-fragment T-plate functions as a washer, allowing adequate fixation and rotational control of even small fragments. In addition, this plate is helpful to avoid further splitting of…

Drs Amanatullah and Wolinsky are from the Department of Orthopedic Surgery, University of California at Davis, California.

Drs Amanatullah and Wolinsky have no relevant financial relationships to disclose.

Correspondence should be addressed to: Philip R. Wolinsky, MD, Department of Orthopedic Surgery, University of California at Davis, 4860 Y St, Ste 3800, Sacramento, CA 95817 (philip.wolinsky@ucdmc.ucdavis.edu).

Open reduction and internal fixation of the medial malleolus is indicated with nondisplaced fractures in individuals with high-functional demands at the ankle, as well as displaced fractures of the medial malleolus that may result in ankle instability and varus talar tilt.1,2

Multiple techniques have been described for fixation of the medial malleolus. Two parallel 4.0-mm cancellous screws oriented perpendicular to the fracture line providing compression is the gold standard for medial malleolus fixation. However, this technique is only applicable for use in fragments that are large enough to allow placement of 2 screws. Smaller fragments, because of the lack of surface area for fixation, present more of a challenge. They can be stabilized using a 4.0-mm cancellous screw oriented perpendicular to the fracture line to provide compression and a Kirschner wire to provide rotational stabilization. Still smaller fragments, such as those with a sagittal splint in the anterior and posterior colliculus of the medial malleolus, may require 2 K-wires and a tension band.2 Neutralization plating has also been proposed for vertical shear fractures of the medial malleolus.3,4

This article presents an alternative method for medial malleolus fixation. The use of a 2.0 mini-fragment plate has several functions: (1) the plate is small enough that it can be contoured to the medial malleolus fragments without being prominent over the subcutaneous tip of the medial malleolus; and (2) the 2.4-mm cortical screws inserted through the plate use the plate as a washer, which is helpful to avoid further splitting of comminuted fragments and prevent the screw head from penetrating osteopenic medial malleolus fragments.

Surgical Technique

The patient is placed supine or prone as the fracture pattern indicates on a radiolucent table. A large radiolucent support platform is constructed with blankets to elevate the operative extremity above the well leg, such that high-quality anterior to posterior and lateral fluoroscopic images can be obtained to verify the position of hardware as well as quality of reduction. The location of the fracture line is confirmed by palpation or fluoroscopic examination. An incision is made over the medial malleolus that extends approximately 2 cm proximal to the fracture line and ends just distal to the tip of the medial malleolus. The subcutaneous tissue and medial retinaculum are reflected with skin to reveal the fractured medial malleolus, and the fracture is cleaned of interposing periosteum and loose debris. The displaced fragment is manipulated into position, and K-wires may be used for provisional fixation of the medial malleolus.

Next, a 2.0-mm, 10-hole mini-fragment T-plate is contoured so that the T portion is bent around the distal tip of the medial malleolus and the shaft of the T-plate runs proximally along the medial border of the tibia (Figure 1). The T is also contoured into a cup shape so that it apposes the medial malleolus (Figure 1B). We do not take down the ligaments attached to the medial malleolus to place the plate. Two or three 2.4-mm cortical screws are placed through the distal T part of the plate to obtain distal fixation and 2 or 3 mini-fragment screws are used for proximal fixation (Figures 1E, F). The contoured mini-fragment T-plate functions as a washer, allowing adequate fixation and rotational control of even small fragments. In addition, this plate is helpful to avoid further splitting of distal comminuted fragments or prevents the screw head from penetrating osteopenic medial malleolus fragments.

The 2.0 Mini-Fragment T-Plate Is Given a Slight Concave Contour to Match the Convex Shape of the Medial Malleolus in the Sagittal Plane (A). The 2.0 Mini-Fragment T-Plate Is Then Contoured to “cup” (ie, Concave) the Convex Shape of the Medial Malleolus in the Coronal Plane (B). Finally, the 2.0 Mini-Fragment T-Plate Is Given a Gentle Convex Contour to Match the Concave Surface for the Medial Tibial Shaft in the Coronal Plane (C). Correctly Contoured 2.0 Mini-Fragment T-Plate (D). Placement of the Mini-Fragment T-Plate on the Medial Malleolus Depicting the “cupping” of the Medial Malleolus (E). Surgical Depiction of Proper Placement of the Contoured T-Plate on the Medial Malleolus (F). Anterior to Posterior (G) and Lateral (H) Radiographic Views of Union Achieved Using Mini-Fragment Fixation of the Medial Malleolus. In This Contoured T-Plate, 3 Distal Cortical Screws and 3 Well-Spaced Proximal Mini-Fragment Cortical Screws Were Used.

Figure 1: The 2.0 Mini-Fragment T-Plate Is Given a Slight Concave Contour to Match the Convex Shape of the Medial Malleolus in the Sagittal Plane (A). The 2.0 Mini-Fragment T-Plate Is Then Contoured to “cup” (ie, Concave) the Convex Shape of the Medial Malleolus in the Coronal Plane (B). Finally, the 2.0 Mini-Fragment T-Plate Is Given a Gentle Convex Contour to Match the Concave Surface for the Medial Tibial Shaft in the Coronal Plane (C). Correctly Contoured 2.0 Mini-Fragment T-Plate (D). Placement of the Mini-Fragment T-Plate on the Medial Malleolus Depicting the “cupping” of the Medial Malleolus (E). Surgical Depiction of Proper Placement of the Contoured T-Plate on the Medial Malleolus (F). Anterior to Posterior (G) and Lateral (H) Radiographic Views of Union Achieved Using Mini-Fragment Fixation of the Medial Malleolus. In This Contoured T-Plate, 3 Distal Cortical Screws and 3 Well-Spaced Proximal Mini-Fragment Cortical Screws Were Used.

Discussion

The contoured medial malleolus T-plate (ie, cup plate) allows fixation and rotational control of even small medial malleolus fragments. We have used this technique for 6 patients with small medial malleolus fracture fragments, and we have follow-up for 3 patients who are now >1 year after open reduction and internal fixation, each achieving clinical and radiographic union at approximately 2 months (Figures 1G, H).

Neutralization plating with a 3.5-mm one-third tubular plate has been examined for vertical shear fractures. It was found to be mechanically inferior with respect to load to failure to perpendicular lag screw fixation with cortical or cancellous screws.3 However, if applied with 2 screws distal to the fracture, a 4-hole, 3.5-mm one-third tubular plate applied in neutralization can be mechanically equivalent in offset axial and transverse stiffness.4 Despite the fact that these studies evaluate the fixation of large vertical shear fractures, they support plate fixation of the medial malleolus and suggest that it may be superior to other fixation types as purchase becomes more difficult with small fragment and perpendicular fixation is not achievable.

References

  1. Portis RB, Mendelsohn HA. Conservative management of fractures of the ankle involving the medial malleolus. J Am Med Assoc. 1953; 151(2):102–105.
  2. Johnson EE, Davlin LB. Open ankle fractures. The indications for immediate open reduction and internal fixation. Clin Orthop Relat Res. 1993; (292):118–127.
  3. Toolan BC, Koval KJ, Kummer FJ, Sanders R, Zuckerman JD. Vertical shear fractures of the medial malleolus: a biomechanical study of five internal fixation techniques. Foot Ankle Int. 1994; 15(9):483–489.
  4. Dumigan RM, Bronson DG, Early JS. Analysis of fixation methods for vertical shear fractures of the medial malleolus. J Orthop Trauma. 2006; 20(10):687–691.

A contoured medial malleolus T-plate provides a simple alternative to tension banding and allows for fixation of small fragments that may not be accessible by more routine screw configurations.

Authors

Drs Amanatullah and Wolinsky are from the Department of Orthopedic Surgery, University of California at Davis, California.

Drs Amanatullah and Wolinsky have no relevant financial relationships to disclose.

Correspondence should be addressed to: Philip R. Wolinsky, MD, Department of Orthopedic Surgery, University of California at Davis, 4860 Y St, Ste 3800, Sacramento, CA 95817 ().philip.wolinsky@ucdmc.ucdavis.edu

10.3928/01477447-20101021-17

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