Tumour Surgery

Aim

 

Tumour removal to gain local control & minimize recurrence while maintaining functional limb 

 

Margins

 

1.  Intralesional

 

Within lesion

- macroscopic tumour remains

 

2.  Marginal

 

Within reactive zone

- microscopic tumour remains

 

3.  Wide 

 

Intra-compartment and outside of reactive zone

- tumour & cuff of normal tissue

 

Beyond reactive zone

- > 7cm level on Te99 scan

- > 5cm level on MRI

- may leave skip lesions behind

- hence MRI

- remove biopsy site

- may mean amputation

 

4.  Radical

 

Extra-compartmental 

- removal of all compartments that contain tumour

 

Amputation is not necessarily Radical

- radical resection possible with limb salvage 

 

Exceptions

 

Skin & subcutaneous tissue

- wide margin is < 5 cm

- radical margin is > 5 cm

 

Extracompartmental lesions

- can't have radical exision of extracompartmental lesions

- no longidudinal barriers to extracompartmental spaces

 

Two compartments

- both compartments must be removed to achieve radical resection

- sometimes only practical way to achieve this is amputation

 

Contamination

- when lesion entered, wound contaminated

- if exposed tissues not removed, margin is intracapsular

 

Surgery & Recurrence rate

 

  IA IB IIA IIB
Intralesional 90% 90% 100% 100%
Marginal 70% 70% 90% 90%
Wide 10% 30% 50% 70%
Radical 0% 0% 10% 20%

 

Limb Salvage

 

About 80 - 85% patients with OS, Ewing's, CS amenable to limb salvage

 

Principles

- must have same survival rates

- must not delay adjuvant treatment

- reconstruction should be enduring with minimal complications

- function should approach that achieved by amputation

 

Contraindications

 

PIN LEG

- pathological fracture

- infection

- NV bundle involvement

- LLD > 8 cm

- extensive muscle loss

- Good v poor biopsy

 

Absolute

 

1.  Can't obtain wide margins

2.   Major NV involvement

- vessel grafts are possible

- nerve remains at risk

3.  Infection

 

Relative

 

1.  Pathological  fracture

- hematoma spreads tumour beyond accurately defined limits

- may necessitate amputate

 

2.  Inappropriate previous biopsy

- contamination of other compartment

 

3.  Significant skeletal immaturity

- predicted LLD > 8cm

- adjustable / growing joint replacements availiable

 

4.  Extensive muscle involvement

- leave leg non functional

 

5.  Medically unfit

 

Technique

 

Radical or wide resection

- extra-articular resection is preferred if a tumour is adjacent to or involves a joint

- prophylactic antibiotics

- no tourniquet if possible

- no eschmarc

- biopsy site excised

- tumour &/or pseudocapsule not visualised during procedure.

- distant flaps should not be developed until the tumour has been removed

- all dead space should be eliminated, & haematoma formation should be prevented

- surgical wound marked with clips for later radiatherapy

- motor reconstruction by regional muscle transfer

- adequate soft tissue cover by flap to avoid skin necrosis

 

Reconstruction Options

 

Arthrodesis

Autograft (remove and irradiate)

Allograft arthrodesis

Allograft arthroplasty

Modular Endoprosthesis

 

Modular Endoprosthesis 

 

Proximal Femoral Replacement

 

Advantage

- early weight bear and rehabilitation

- lower infection rates than allograft

- no risk of non union like allograft

 

Types

- rotating hinge

- expandable if final LLD > 2cm

- modular

 

Contraindications

- < 8 years old

 

Complications

 

Early complications

- wound infection

- skin necrosis

- DVT

- neuropraxia

- instability

 

Late complications

- prosthesis breakage

- LLD 

- lysis

- instability

- late infection

 

Expandable Prostheses

 

Lengthen 2cm every 18 months

- surgical procedure

- excise fibrous tissue to prevent joint stiffness and protect NV bundle

 

Average lengthening 9 cm

 

50% complication rate

 

Massive Allograft 

 

Massive Femoral Allograft0001Massive Femoral Allograft0002

 

Advantage

- biological reconstruction

 

Disadvantage

- incorporation is a slow and incomplete process

- 20% will fail within 5 years

 

Indications

- patient < 20 years old

 

Complications

- infection 11% (sometimes only salvageable by amputation)

- fracture 16% (up to 3 years later)

- joint instability

- non union (increased by chemo/DXRT)

- OA (15% at 10 years with osteochondral allograft)

 

Results

 

Intercalary > osteochondral

 

Intercalary

- 80% good results

- 30% non union at one osteosynthesis site requiring intervention

 

Osteochondral

- 73% good results

 

Allograft - prosthetic

- 77% good results

 

Rotationplasty

 

Concept

- creates a functional BKA

- superior to AKA

 

Advantage

- low complication rate

- very functional

 

Disadvantage

- high rate cosmetic dissatisfaction

- patients should meet others with same procedure

 

Indication

- young child in whom endoprosthesis has high rate failure

- wide resection about knee

- sciatic nerve preserved

 

Technique

- tibia rotated 180o

- fused to femur

 

Complications

- post operative vascular occlusion

- tibio-femoral pseudoarthrosis

 

Results

- patients can play sports

 

Limb lengthening

 

Usually very large osseous defects

- difficult

- associated with significant complications

- better suited as adjuvant to other procedures or for smaller defects

 

Vascularised fibula graft

 

Advantage over allografts

- more rapid incorporation

- stronger initial construct secondary to graft hypertrophy

 

Disadvantage

- increased surgical time

- surgical site morbidity

- size limitations

- stress fractures

 

Amputation v Limb Salvage

 

Limb Sparing

Amputation

Local Recurrence

5 - 10%

5%

Survival

70%

70%

Functional Outcome

Good

Good

Initial Cost

High

Low

Long term cost

 

 

 

Outcome

- limb salvage often functionally better

- complication rate and incidence multiple surgery higher