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Pilon Frx: ORIF of the Fibula

- Discussion: (see pilon frx discussion)
    - fibula is usually fractured above the joint line;
    - some authors will avoid ORIF of the fibula in these injuries if there is excessive fibular comminution (ie poor chance of good fixation) and
              if there is excessive varus of the articular surface (ORIF would accentuate the varus);
    - fibular incision often must be placed posteriorly indorder to accomodate an adequate skin bridge for tibial incision;
    - in some cases, the fibula can be anatomically reduced along with application of external fixator which allows fracture to be brought
             out to length and which allows the talus to be centered under the tibia;
    - then 7-21 days later, the medial column and articular surface can be restored once the soft tissues have healed;
    - pilon frx w/ intact fibula:
          - usually small fragment of Chaput tubercle stays in its normal relationship to fibula because of intact syndesmotic ligaments, while
                   remainder of joint surface is displaced upward w/ talus;
          - ligament injury in these cases is confined to lateral collateral ligament system;
          - references:
                  - Ipsilateral intact fibula as a predictor of tibial plafond fracture pattern and severity.
                  - Is the absence of an ipsilateral fibular fracture predictive of increased radiographic tibial pilon fracture severity?
    - pilon frx w/ fractured fibula:
          - proper fibular length is key to reduction of tibial articular surface;
          - shortening of the fibula will cause malreduction of the major tibial fracture and the ankle tends to drift into valgus;
                 - if normal valgus curve of the fibula is not restored, then the ankle may assume a varus position;
          - does the fibula frx require fixation? (from Williams TM, et al (1998))
                 - w/ comminuted frx, the benefits of restoring length may be outweighed by wound healing problems;
                 - when the the joint line lies in varus, restoration of the fibular length may worsen tibial joint line varus deformity;
                 - comparing fibular plate fixation vs no plate fixation:
                         - frx reduction: no sig difference, but trend for better reduction w/ plate fixation;
                         - time to healing: 20 weeks vs 24 weeks (no difference);
                         - lateral wound healing problems: occurred in 5/22 fractures in plate fixation group;
                  - External fixation of the tibial plafond fractures: Is routine plating of the fibula necessary?

- Incision:
    - standard surgical approaches to distal tibia and fibula are used;
    - posterolateral incision is made to fibula on lateral aspect of ankle to allow largest possible skin bridge between lateral fibular 
           incision and the anteromedial incision;
           - to be safe, width of this skin bridge should be maintained at 7 cm;
           - dissection usually proceeds over the lateral edge of the peroneals, but may also be brought behind the peroneals for proximal access
                    to the frx, or for access to the posterior malleolus;
    - proximally, one must be wary of the superficial peroneal nerve as it pierces the lateral intermuscular septum and proceeds anteriorly;
    - distally, sural nerve is avoided as it begins to follow anterior course;

- Frx Reduction:
    - when fibular frx is not comminuted, anatomic reduction should be performed to restore length;
          - if the fibular is left short, malrotated or axially deviated, there will be reduction consequences for the tibia;
    - Chaput fragment:
          - refers to the anterolateral tibial fragment, which is present in some pilon frx;
          - once the fibula is reduced, the Chaput fragment can be fixed;
    - comminuted frx:
          - if fibula is comminuted, length may be calculated using a template from the opposite side;
          - gaining fibular length restores tibial length by ligamentotaxis thru intact syndesmotic ligaments and the anterolateral tibial fragment;
          - avoidance of fibular fixation:
                 - w/ comminuted frx, the decision can be made to not fix the fibula in which case an external fixator can be used to span the ankle joint in order to effect the fibular reduction;
                        - see: tibial metaphyseal - diaphyseal fixation;

- Implants:
    - length will be restored by restoration of length to fibula & butressing it w/ 1/3 tubular plate or occassionally 3.5 DC plate when length
              and comminution are severe;
    - lag screw then is placed using 3.5 mm drill for gliding hole and 2.0 mm drill for the opposite cortex using 3.5 mm inner drill sleeve;
    - screw length is determined, hole is tapped for 3.5 mm screw, & proper screw length is placed;
    - 1/3 tubular plate is then contoured to lateral aspect of fibula & secured w/ 3.5 mm cortical screws;
    - if length cannot be obtained easily at surgery, then the plate may be contoured and fixed to the distal fibula;
    - w/ screw placed proximal to the plate, length is obtained using a laminar spreader between screw and the proximal end of the plate;
    - proximal end of 1/3 tubular plate is secured to bone w/ 3.5 mm cortical screws;
    - plate is used to maintain length of fibula as well as acting as butress plate;
    - once fibula is secured at appropriate length, anterior to medial incision is made 5 mm lateral to tibial crest and curved medially over
              anterior tibia to medial malleolus tip

Intramedullary fixation of fibular fractures associated with pilon fractures

Trans-syndesmotic fibular plating for fractures of the distal tibia and fibula with medial soft tissue injury: report of 6 cases and description of surgical technique.

Intramedullary nail fixation of fibular fractures associated with tibial shaft and pilon fractures