1 Preliminary considerations topenlarge
Usually, the soft-tissue injury is minimal and therefore, these fractures can often be fixed in one stage. Timing can be crucial. Optimal time is either in the first six hours after injury, or after 4-6 days depending on the soft-tissue swelling.
The fibula can be intact or not. Additional injury of the syndesmotic ligaments must be detected during the operation. It might be necessary to address these injuries as well by suture and/or syndesmotic fixation.
2 Fracture orientation and choice of approach topenlarge
Many pure split fractures of the distal tibia can be approached minimally invasive using stab incisions for the application of reduction forceps and screw fixation. Depending on the fracture pattern, a smaller open approach can be used for the insertion of an antiglide plate.
This latter approach has to be placed in relation to the position of the proximal end of the fracture and can be placed wherever the fracture ends proximally:
- Anteromedial approach
- Anterolateral approach
- Posteromedial approach
- Medial approach
- Posterolateral approach
Interfragmentary lag screws should be inserted from the small fragment to the large intact articular segment of the tibia, providing optimal compression force by the long threaded hole. In the illustrated cases with smaller fractured fragments, plate and screws are inserted from the same direction. With a large fragment, it might be necessary to insert the lag screws at the joint level from the opposite direction of the plate, as shown in the following example. See also the additional material on lag screw principles.
The split fracture can occur in the frontal or sagittal plane, or in between.
The following case demonstrates the surgical management of a partial articular split. The fracture is a large posteromedial fragment of the distal tibia, involving more than 80% of the articular surface. There is a moderate displacement with shortening, resulting in a small intraarticular step and a larger gap. The fracture plane is located between the frontal and sagittal.
It is combined with a proximal fibular fracture and with a rupture of the anterior syndesmotic ligament.
3 Patient preparation top
Depending on the approach, the patient may be placed in the following positions:
4 Approach topenlarge
Since the proximal end of the illustrated tibial fracture is posteromedial, this is where an incision is required. A small posteromedial approach is performed.
After dividing the subcutaneous fat preserving the greater saphenous vein and nerve, the posteromedial tibial crest is exposed by a small longitudinal incision of the fascia of the deep flexor compartment.
Distal anterolateral approach
A separate small, distal anterolateral approach is helpful to apply a reduction forceps close to the joint and to insert separate lag screws.
Care has to be taken to the superficial peroneal nerve which crosses this approach in a slightly oblique direction.
5 Reduction topenlarge
The fracture line is cleaned.
Reduction is achieved by fixation of a one-third tubular plate. The four-hole plate is placed at the level of the proximal end of the fracture, through the posteromedial approach. This plate aids reduction and acts in an antiglide mechanism.
A first screw is placed just proximal to the fracture and tightened, to reduce the fracture by pushing the fractured fragment distally.
The remaining distal gap is reduced with large pointed reduction forceps applied percutaneously. Temporary K-wires can be added if necessary.
The reduction of this large articular piece (red) must be completely anatomical.
Assessment of the reduction can be performed visually at the proximal end of the fracture and by using fluoroscopic control at the joint level. See also the content on assessment of reduction.
6 Insertion of lag screws topenlarge
When anatomic position of the fractured fragment is confirmed, lag screws are inserted above the articular surface and perpendicularly to the fracture plane.
In smaller fractured fragments, plate and screws may be inserted from the same side, through a slightly enlarged approach.
See also the additional material on lag screw principles.
Fracture stabilization is finished with a lag screw through the antiglide plate to prevent a secondary displacement of the proximal end of the large fragment.
7 Assessment of ankle mortise stability topenlarge
Stability of the ankle mortise (syndesmotic ligaments) has to be checked under fluoroscopic control using the pronation/external rotation test as shown in the illustration. Alternatively, depending on the location and size of the anterolateral approach, the hook test can be performed.
If a syndesmotic disruption is present, there will be rotational instability of the distal fibula with widening, under stress, of the syndesmosis in the anterior part.
Since this is present in the illustrated case, a suprasyndesmotic fibulotibial positioning screw will be added.
Note: Intraoperative x-rays or image intensification are advised to conﬁrm the position of the screw and the distal tibiofibular joint.
8 Fixation of the syndesmotic complex topenlarge
After reduction of the fibula at the syndesmosis using either manual compression or percutaneously applied large reduction forceps, introduce the positioning screw through a separate stab incision obliquely from posterior to anterior at an angle of 25–30° and parallel to the tibial plafond. The ankle should be neutral or dorsiflexed during the insertion of this screw.
Place a 3.5 mm cortex screw just proximal to the tibiofibular joint. As this screw is not intended to act as a compressive lag screw, the thread must be tapped in both ﬁbula and tibia.
In complete disruption of the syndesmosis with high instability, two screws are advisable.
Note: Intraoperative x-rays or image intensification are advised to conﬁrm the position of the screw and the distal tibiofibular joint. See also the content on assessment of reduction.