Tibial Plateau Fractures

Epidemiology

• 1% of all fractures
• Lateral tibial plateau 70%
  • More common as knees in valgus & forces usually cause valgus
• Medial plateau is involved in isolation in around 15%
• Bicondylar fractures occur in 15%

Aetiology

• High violence injuries in young patients
  • Indirect forces
  • Axial loading
• Age & bone quality determine fracture pattern
  • Younger patients develop split, older get depression
  • Younger patients have higher rate of ligamentous injury (i.e., on opposite side)
  • Older patients compact subchondral cancellous bone

Associated injuries

• ligamentous injuries
• popliteal artery injury
• neurologic injury (esp peroneal nerve)
• compartment syndrome

Anatomy

• Medial tibial plateau
  • larger
  • concave from front to back & from side to side
  • medial plateau is stronger than lateral, so injury here is more rare & is accompanied by more soft tissue damage
• Lateral tibial plateau
  • convex from side to side & front to back
• Menisci
  • lateral meniscus covers larger area than medial

Classification

Schatzker classification

Type	Description	Features
I	Split of lateral plateau	~seen in young people with strong bone ~Often associated with tear of lateral meniscus, which is trapped in fracture
II	Split depression fracture	~Caused by valgus blow with axial loading ~Typically occurs in patients older than 40
III	Pure depression (die punch) of lateral tibial plateau	~Central depressions are usually more stable than lateral or posterior
IV	Fracture of medial tibial plateau	~Much less common, associated with large forces. ~Often associated with lateral collateral ligament injuries ~Many of these injuries represent knee dislocation that has reduced ~fracture pattern most associated with vascular injury
V	Bicondylar fracture	~Usually result of pure axial load applied to knee ~hallmark of this injury is that at least small part of metaphysis remains as part of joint
VI	Plateau fracture with complete dissociation of metaphysis from diaphysis

AO classification

• A Extra-articular
• B Unicondylar
• C Bicondylar

Hohl and Moore Fracture Dislocation Classification

Type	Description
I	Coronal split fracture
II	Entire condylar fracture
III	Rim Avulsion fracture
IV	Rim Compression fracture
V	Four part fracture

Assessment

• Need to carefully assess soft tissue injuries:
  • Fracture blisters, skin wounds, tenting of skin, vascular compromise
  • detailed neurologic exam
  • look for associated injuries
  • more common with grades IV-VI
    • compartment syndrome
    • neurovascular injuries
    • ligamentous injuries

Imaging

XR

• AP, lateral, oblique images
• Opposite knee can serve as useful template
• Look for subchondral bone below articular surface
• Can do 15° caudal plateau views, obliques
• Stress radiographs may be used if considering non-operative
• ** the medial plateau is concave, the lateral plateau is convex (in both planes)
  • lateral plateau is also higher than medial

CT scans

• mandatory

MRI

• can help identify meniscal pathology
• use particularly in type I fractures & or those in which percutaneous fixation is contemplated

Treatment

• Depends on soft tissues
  • Skin compromised = Ext fix
    • open fractures require I & D
    • grade 2 & 3 open fractures probably best treated with temporary ex fix & late reconstruction of articular surface or ring fixator & mini-open arthrotomy to reduce articular surface
  • may require plastic surgery – usu rotational muscle flap in this location (gastroc)
• Nonoperative
  • Hinged knee brace can be used for minimally displaced, or non-operative patients
  • Non/partial weight bearing for 8-12 weeks
• ORIF
  • Absolute
    • open fractures
    • compartment syndrome
    • acute vascular injury
  • Relative
    • Joint depression
      • Acceptable amount not agreed upon
      • < 3-5mm are normally quoted
        • up to 1cm quoted
      • Long term followup has not demonstrated correlation between degree of depression & development of arthritis
    • Instability
      • of greater than 10° of nearly extended knee (varus /valgus) c.f. other side
      • joint depression severe enough to lead to instability is predictive of poor result
  • Tips & Tricks
    • Either immediate before significant swelling or delayed to allow soft tissues to heal
    • minimal stripping of comminuted fragments & careful soft tissue handling
    • use periarticular large fragment plate laterally (types I/II/V/VI)
    • use either anterior approach or 2 incision technique for bicondylar fractures
    • bicondylar fractures need 2 plates (medial buttress plate)
    • type IV fractures need buttress plate/screw rather than just interfragmentary screws
    • almost always use ICBG
    • use large fragment distractor to aid in reduction thru ligamentotaxis
    • risk of infection (10-40%) & wound slough
    • Submeniscal arthrotomy provides access to joint surfaces
• Surgical treatment
  • Type I
    • percutaneous cannulated screws
  • Type II
    • ORIF with elevation, bone graft & lateral periarticular plate using hockey stick lateral incision
  • Type III
    • can attempt to elevate via cortical window, bone graft & stabilize with couple of screws
    • Use arthroscope to assess adequacy of reduction
  • Type IV
    • percutaneous or open techniques
    • Nonoperative management is associated with high rate of varus malunion
  • Types V & VI
    • Combined Anterolateral & posteromedial incision
      • Safest way to access bicondylar fractures
    • Extensile midline anterior incision
      • this can also be used in any subsequent knee replacement
    • Schatzker describes doing Z cut of patellar tendon( tubercle osteotomy may be almost impossible to fix) & division of medial & lateral capsule below menisci, flapping whole up; done via midline incision. At end of procedure tendon is protected by tension wire or heavy suture
• Tips
  • In very severe fractures less injured condyle is fixed first
  • Can consider using one or two femoral distractors to help with indirect reduction of fracture
  • If hybrid external fixation is used wires should be placed no closer than 15mm to joint
  • Once bony parts of injury have been treated ligaments should be assessed. Any posterolateral injury should be addressed concurrently
• external fixator
  • spanning ex fix from femur to tibia to hold soft tissues out to length & maintain reduction
  • half pins in femur & tibia
  • best to align the articular surface early, with limited fixation
  • once soft tissues have healed » ORIF
• ring fixator:
  • mini-open reduction of articular surfaces using K-wires & small fragment screws
  • fine wires at level of articular surface (at least 2) & half pins in tibia
  • reduced deep infection rate & soft tissue complications

Complications

• Nonunion
  • is very rare, except in Schatzker VI injuries
• Stiffness
  • is common
  • If it is excessive & not responsive to aggressive physiotherapy adhesiolysis & MUA is indicated
• Infection (6 to 12%)
  • Wound problems are the biggest problem in plateau fractures
  • Important to respect soft tissues, etc
  • Time surgery appropriately
  • Concern with large elevations of skin (bicondylar plates)
• Loss of reduction
  • Should use buttress plates, unless bone quality is very good
• Post traumatic arthrosis
  • Cartilage damage from initial injury
  • Also if residual joint incongruity
  • Important to preserve the meniscus
  • Avoid immobilization
• Union at the metaphyseal – diaphyseal junction can be a problem

Outcomes

• – 90% good/excellent results with ORIF (all types of fractures) – Lansinger et al., 1986 (seems too good to be true)
• Minimally displaced are expected to do well, even with non-operative
• Difficult to assess outcomes of displaced, as studies differ in classification, indications, etc
• Helpful that the lateral meniscus covers most of the plateau