Assessment and management of fractures about the knee
by James Donaldson

Scenario: called to A&E to assess a 24 year old woman who fell off her horse and injured her knee.

History:
Age, occupation, sporting level and aspirations
Time/date of injury

Past medical/surgical history

Medication/drugs and allergies

Last ate/drank (for timing of emergency surgery if needed)

AP and lateral X-rays of the knee are required in all injuries

• Often an MRI scan will be requested if there is a suggestion of ligament or meniscal injury (see soft tissue knee section)
• Bony injuries usually need surgery

Patella fracture

Mechanism: Direct trauma or eccentric quads contraction

Signs & symptoms:

• Pain and bruising anteriorly
• May be able to walk
• Palpable patella defect
• Haemarthrosis
• Difficulty in performing a straight leg raise (SLR)
• Assess for knee wounds or open fracture

Management:

• If undisplaced and able to SLR – cylinder plaster, FWB and non-operative management. Can be discharged home if safe
• If displaced or extensor mechanism disrupted admit for fixation, often tension band wire. AK backslab for comfort

Lateral x-ray demonstrating displaced patella fracture

---

Distal femoral fracture

Mechanism: High energy (young) or low energy (elderly)

Signs & symptoms:

• Pain, swelling, deformity, unable to weight bear
• Potential for popliteal artery injury – assess thoroughly
• Call senior urgently if NV concerns

Management:

• Analgesia, skin traction, admit
• Hinged knee brace and NWB if undisplaced  Most will need ORIF
• Assess neurovascular status and call senior urgently if there is a deficit

AP & lateral x-rays of comminuted distal femur fracture

---

Tibial plateau fracture

Mechanism: Varus or valgus force with axial load

Signs & symptoms:

• Commonly associated with other intra-articular injuries
• Significant soft tissue injury
• Assess compartments and NV status
  

Management:

• Admit, above-knee backslab, analgesia
• Likely to need CT scan
• Schatzker classification 1-6
• If minimally displaced and low energy can be treated non-operatively
• Most will need ORIF
• If severe soft tissue swelling a temporary ex-fix can be applied whilst soft tissues improve
• Call senior if open or neurovascular injury
  

AP x-ray demonstrating displaced, comminuted, intra-articular tibial plateau fracture

---

Tibial spine fracture

Mechanism: Similar to ACL injury. Associated with other intra-articular knee pathology in 40% of case.

Signs & symptoms:

• Commonly in adolescents
• Fracture of the bony attachment of the ACL
• Pain, immediate knee effusion and limited ROM
• Positive anterior drawer test

Management:

• MRI needed to assess for other injuries
• If undisplaced immobilize in 0-20 and treat non-operatively. # clinic follow up 1 week
• Surgical fixation within 1-2 weeks if displaced
• Without other significant injury, this can be investigated and managed on an out-patient basis

AP and lateral x-rays showing displaced tibial spine fracture

---

Tibial tuberosity fracture

Mechanism: Active quads extension with knee flexed.

Signs & symptoms:

• Adolescent fracture
• Sudden pain
• Unable to straight leg raise or quadriceps lag
• Swelling and tenderness over tibial tuberosity
• Assess for compartment syndrome anteriorly

Management:

• Long leg cast in extension if minimal displacement (<2mm). Can be discharged if safe with follow up in 1 week
• If displaced needs closed or open reduction and fixation.
• Admit for surgery. Backslab for comfort, elevation and analgesia
• If skin is compromised call senior

Lateral x-ray displaying displaced tibial tuberosity fracture