Split Compression Frx (Type II Frx)


- Discussion: Split Compression /  Type II Fractures:
    - split fragment from articular surface along w/ depressed area similar to that of local compression frx;
    - lateral wedge frx is combined w/ varying deg of depression of adjacent remaining wt bearing portion of lateral tibial plateau;
    - depression is usually located anteriorly or centrally;
    - wedge frx may vary from a small rim fracture to a frx involving upto 1/3 of the articular surface;
    - displacement of frx consists of widening of joint w/ spreading apart of wedge, in combination w/ central depression of lateral plateau;
    - mechanism: valgus stress and axial compression forces that 1st cause frx of split fragment & then cause  depression frx of part of remaining surface;
    - associated injuries:
          - look for fracture of fibular head and neck
          - most often S.C.F. involves lateral plateau;
          - ligament injuries are found in 19% of split compression frx;
                  - look for widening of medial cartilage space of knee &
                  - avulsion of bone from medial femoral condyle;


- Radiographs:
    - CT scan accurately defines anatomy;
    - 20% of SCF have a collat ligament injury;
           - look for widening of medial cartilage space;
           - avulsion of bone from medial femoral condyle;
           - gentle valgus stress may produce deformity of 20 to 25 deg;
    - grade depression by measuring vertical distance between lowest point on medial plateau
                 & lowest depressed frag of lateral plateau;
         - depression > 4 mm is sig. & if left untreated results in joint incongruity, valgus deformity,
                 and a sense of instability;
          
         

- Non Operative Rx:
    - indicated for frx w/ < 6 mm of articular depression assumming that split fragment is restored to its anatomic position w/ traction;
          - split fragments assoc. w/ articular depression of > 6 mm can almost always be reduced, however, articular incongruity will remain &
                    there will be insufficient support for femoral condyle;
    - Traction:
         - even if traction fails to yeild an accetable reduction, pt will note pain relief & will be able to begin early ROM;

- Indications for Operative Treatment:
    - joint surface is depressed  > 1 cm (4 mm in young patients)
    - valgus is > than 10 deg;
    - closed reduction of split fragment is not maintained;
    - associated posterior wedge requires fixation since this significes significant posterior instability;

- Percutaneous Fixation:
    - type II frx may often not be amenable to percutaneous fixation because an acceptable reduction of the depressed fragment can be difficult to obtain;
    - part of the difficult lies in the fact that the depressed fragment is buried  w/ in the plateau and is obsured by the frx lines of split fragment;
    - hence the patient should be forewarned about the need for open reduction;
    - reduction:
           - if the split fragment is depressed, it can be brought out to length with use of a femoral distraction;
           - once the fracture fragment has been elevated w/ ligamentotaxis, then the medial or lateral displacement can be corrected;
           - reduction is achieved w/ percutaneous applied reduction forceps w/ flourscopic assistance;
           - consider applying the reduction forceps eccentrically, and then torque reduction forceps to achieve reduction;
           - adequate reduction implies less than 1-2 mm step off;
           - depressed fragments: make a small window in the metaphyseal cortex and elevate depressed fragment with a bone tamp;
    - fixation:
          - percutaneous screws:
                 - wedge of type I frx of lateral plateau can usually be fixed w/ only cancellous percutaneous lag screws and washers;
                 - consider 6.5 mm cancellous screws (over washers) which are placed in a triangular position;
          - anti-glide screw:
                 - antiglide screws are typically placed after 1-2 percutaneous lag screws are placed thru the frx fragment;
                 - antigluide screws (over washers) are placed just distal to the frx edge to prevent distal displacement;
                         - 4.5 mm cortical screws over washers are typically used;
    - references:
          - [Comparison study on effectiveness between arthroscopy assisted percutaneous internal fixation and open reduction and internal fixation for Schatzker types II and III tibial plateau fractures].
          - Balloon Tibioplasty: A Useful Tool for Reduction of Tibial Plateau Depression Fractures
          - Percutaneous Screw Fixation of Tibial Plateau Fractures.
          - Closed reduction and percutaneous screw fixation for tibial plateau fractures
          - Indirect reduction and percutaneous screw fixation of displaced tibial plateau fractures.

- Open Surgical Treatment: (Synthes Products)
  - PreOp Planning
         - most important step in reconstruction of any intra articular frx, is to expose the fracture w/o devasclarizing the fragments;
  - Treatment Plan:
         - open reduction;
         - elevation of the depressed plateau;
         - bone grafting of metaphysis;
         - fixation of the fracture with cancellous screws
         - butress plating of the lateral cortex;
  - Position:
         - for optimal exposure, consider supine position, w/ a bolster under thigh, & table broken so that the knee is flexed 90 deg;
         - this position allows increased exposure submeniscally;
  - Surgical Approach:
         - consider a longitudinal lateral parapatellar approach;
         - elevate anterior compartment muscles off proximal tibia, exposing tibial flare and split frx;
         - trace frx is to joint line and enter joint thru transverse sub-meniscal interval;
              - if needed, transect attachment of anterior horn of meniscus;
              - elevate meniscus superiorly to expose intra-articular frx segment;
  - Exposure of Depressed Segment:
         - split frx is hinged open anteriorly to expose depressed joint surface;
              - this surface is elevated to appropriate level & defect is filled w/ or local cancellous bone or allografts;
         - apply small impactor from below to disimpact and elevate depressed segment;
         - apply bone graft from below;
         - elevated segment may be supported w/ K wires (consider biodegradable);
         - ref: Inside out rafting K-wire technique for tibial plateau fractures 
  - Reduction:
         - consider use of tenaculum or pelvic reduction clamp across both plateau to generate compression;
  - Implants: (Synthes Products)
         - at this point, the frx has essentially been turned into a type I frx;
         - w/ minimal comminuation and good bone stock, consider 6.5 mm cancellous screws w/ or w/o washers;
         - if cannulated screws are used, these are inserted over K wires;
         - if split fragment is not comminuted, 2 or 3 cancellous screws are  inserted parallel to & > 1 cm distal to articular surface;
               - an additional, cortical anti-glide scrw w/ washer is inserted distally;
         - in older patients, w/ osteoporotic bone, lag screws alone cannot prevent redisplacement of fragments; (need butress plate);
         - a comminuted frx, requires an L or T shaped buttress plate; another indication, for butress plating is assoc subcondylar frx;

               

- Post Operative Care and Compications:
    - Loss of Reduction of split frag is main complication of Rx in split compression frx;
           - this is found more commonly with closed treatment;
    - w/ percutaneous IF, a cast brace is used until frx healing is complete;
    - w/ use of a butress plate to assure rigid fixation, external support  is not required postoperatively



Indirect Reduction and Percutaneous Screw Fixation of Displaced Tibial Plateau Fractures.

Split depression tibial plateau fractures: a biomechanical study.

Combined Arthroscopic Treatment of Tibial Plateau and Intercondylar Eminence Avulsion Fractures

Outcomes of Schatzker II Tibial Plateau Fracture Open Reduction Internal Fixation Using Structural Bone Grafts




Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, May 27, 2013 5:12 pm