Authors of section

Authors

Florian Gebhard, Phil Kregor, Chris Oliver

Executive Editor

Chris Colton

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ORIF - anterior screws for large fragments

1. Principles

Hoffa fractures involve important load-bearing areas of the knee joint surface, and the principles of anatomical reduction and absolute stability of fixation apply.

Fixation can be achieved indirectly with 3.5 mm or 4.5 mm screw systems. It is advantageous to use cannulated screw systems.

In small fragments direct fixation is required through a posterior approach.

At least two screws should be used, in order to prevent fragment rotation and to achieve satisfactory compression.

No implant is allowed to violate on the articular surface.

Similar principles apply if both condyles are fractured.

Completed osteosynthesis

2. Patient preparation

3. Approaches

For this procedure the following approaches may be used:

These difficult fractures can be approached for reduction and fixation from the anterior aspect. If the posterior condylar fragments are large, the fracture lines will usually be accessible by the parapatellar approach.

For shallower fragments the standard lateral/anterolateral approach is necessary to gain more posterior access: alternatively, a posterior approach should be considered.

For the medial side, a straight medial approach can be used, taking care to avoid injury to the infrapatellar branch of the saphenous nerve.

4. Reduction

Achieve reduction using periosteal elevators and a large pointed reduction forceps. The joystick technique, in which a small Schanz screw is inserted from the extraarticular surface, is also useful (as illustrated).

The joystick technique

5. Fixation

Guide-wire insertion

Insert the guide wires as perpendicularly as possible to the fracture plane.

Inserting guide wires

Check guide-wire placement

Check the correct guide-wire insertion under fluoroscopic image intensifier control. The condylar surface must not be perforated.

The condylar surface must not be perforated

Countersinking

Countersink manually, deeply enough to allow for fully buried screw heads.

Pitfall: countersinking too deeply
Be aware of countersinking too deeply into the cancellous bone, which often happens using a power tool.

Do not perform countersinking when planning the use of headless compression screws.

Countersinking manually

Screw length determination

Determine the appropriate screw lengths, inserting the dedicated measuring device into the countersunk hole.

Determining the appropriate screw lengths

Screw insertion

Insert the screws using the cannulated screw driver and check under image intensifier control in the lateral and oblique views that the screw length was chosen correctly.

Inserting the screws

X-ray

X-ray showing the completed osteosynthesis.

X-ray showing the completed osteosynthesis

6. Aftercare following screw (and plate) fixation of partial articular fractures

Introduction
Impediments to the restoration of full knee function after distal femoral fracture are fibrosis and adhesion of injured soft tissues around the metaphyseal fracture zone, joint capsular scarring, intra-articular adhesions and muscle weakness.

Continuous passive motion is a low load method of restoring movement and is a useful tool n the early post operative phase. It must be used in combination with muscle strengthening programs. With stable fracture fixation, the surgeon and the physical therapy staff will design an individual program of progressive rehabilitation for each patient.

The regimens suggested here are for guidance only and not to be regarded as proscriptive.

Functional treatment
Unless there are other injuries, or complications, joint mobilization may be started immediately postoperatively. Both active and passive motion of the knee and hip can be initiated immediately postoperatively. Emphasis should be placed on quadriceps strengthening and straight leg raises. Static cycling without load, as well as firm passive range of motion exercises of the knee, allow the patient to regain optimal range of motion.

mio dynamic condylar screw dcs

Weight bearing
Touch-down weight bearing (10-15 kg) may be started immediately with crutches, or a walker. This will be continued for 6-8 weeks postoperatively. After that, touch-down weight bearing progresses to full weight bearing gradually over a period of the next 2 to 3 weeks. In general, patients are full weight bearing without devices (e.g., cane) by 10-12 weeks.

Follow up
Wound healing should be assessed at 2 to 3 weeks postoperatively. Subsequently 6 week, 12 week, 6 month, and 12 month follow-ups are usually made. Serial x-rays allow the surgeon to assess the healing of the fracture.

Implant removal
Implant removal is not essential, unless there are implant-related symptoms after consolidation.

Thrombo-embolic prophylaxis
Consideration should be given to thrombo-embolic prophylaxis, according to local treatment guidelines.