Osteoid Osteoma

 

Osteoid OsteomaOO posterior tibiaRF ablation femur

 

Definition

 

Benign, bone-forming neoplasm

- small nidus of neoplastic tissue

- surrounded by a wide zone of mature, reactive bone

 

Epidemiology

 

10% of benign bone tumours

Young people aged 5 - 25

Male:Female  3:1

 

Clinical

 

Night pain

 

Pain secondary to prostaglandin production

 

Relieved by aspirin / NSAIDS

 

Site

 

Femur and tibia (50%)

 

Posterior elements spine (10%)

 

Hands and feet

 

Cortical / Medullary

Extra-articular / Intra-articular

 

Natural history

 

Gradual resolution with time

 

X-ray

 

OO xray

Sclerotic bone

 

Tibia OO 1Tibial OO 2

 

CT 

 

Best investigation

- lucent nidus surrounded by dense bone

 

Osteoid osteomaOO sagittal ct

Osteoid osteoma tibia

 

Tibial OO CTCT OO 1

 

OO femur 2OO femur 1

Osteoid osteoma femur

 

MRI

 

OO MRI 1MRI OO 2

 

Knee OO 1Knee OO 2Knee OO 3

 

Pathology

 

Gross

 

Nidus

- < 1 cm diameter

- red - pink

- surrounded by sclerotic bone

 

Histology

 

Osteoid Osteoma Histology Nephron GNU Free Documentation License Version 1.2 httpwww.gnu.org/copyleft/fdl.html

 

Nidus - highly vascularised osteoid

Rim - osteoblasts and thickened trabecular bone

 

Differential Diagnosis

 

Brodies abscess

Osteoblastoma - nidus > 1.5 cm

Stress fracture

 

Management

 

Options

 

Prolonged NSAIDS - can take years to resolve

Radiofrequency ablation

En-bloc excision / currettage

 

Radiofrequency Ablation

 

Osteoid Osteoma Radiofrequency Ablation0001Osteoid Osteoma Radiofrequency Ablation0003

 

OO posterior tibiaOO posterior tibia RFA

 

Concept

 

High frequency current

Thermal ablation

 

Technique

 

RF ablation PDF technique

 

GA

- introduce electrode under CT

- tissue for histology

- radiofrequency

- increase temperature to 90o for 4 - 6 minutes

 

Complications

 

Neurovascular injury

- > 10 mm from NV bundles

 

Skin burns with osteoid osteoma of subcutaneous bones

 

Cartilage damage with intra-articular lesions

- avoid articular approach

- > 10 mm from cartilage surface

 

Results

 

Rosenthal et al Radiology 2003

- 126 RF ablation procedures with 2 year follow up

- primary procedure - success rate 91%

- repeat procedures - success rate 60%

 

Rosenthal et al JBJS Am 1998

- 69 patients operative excision - recurrence rate 9%, length of stay 5 days

- 33 patients RF ablation - recurrence rate 12%, same day discharge

 

Surgery

 

Issue

 

Can be difficult to identify

Tend to excise excessive bone

Fracture risk

 

Technique

 

Must completely remove nidus

Do not have to completely remove sclerotic bone

 

Intraoperative CT guidance

- direct incision over lesion

- shave cortex off with high speed burr to reactive bone 

- scoop nidus out once hit hypervascular zone & sent for fresh frozen sections

- burr 2mm zone out

- can leave strong reactive bone behind

 

Intra-articular Osteoid osteoma

 

Issue

 

Risk cartilage damage from RF ablation

 

Options

 

Arthroscopic resection

 

Knee OO 4Knee OO 5Knee OO 6

 

Results

 

Ge et al Eur J Orthop Surg Traumatol 2020

- systematic review of arthroscopic treatment of upper limb osteoid osteomas

- 32 cases in 19 articles involving shoulder / elbow / wrist

- no recurrence

- success rate 94%

- 2/24 (8%) in the elbow had incomplete resection

 

Ge et al J Foot Ankle Surg 2019

- systematic review of arthroscopic management of ankle osteoid osteomas

- 17 articles, 27 cases, most on talar neck

- success rate 95%, 2 recurrences

 

Spine Osteoid Osteoma

 

Symptoms

 

Back pain

Scoliosis + back pain

 

Location

 

Posterior elements

 

Options

 

RF ablation

Surgical excision

 

RF Ablation

 

Sangiorgio et al Eur Spine J 2023

- systematic review of RF ablation versus surgical excision in spine

- surgery treatment success 86%, recurrence 6%, complications 9%

- RF ablation treatment success 89%, recurrence 7%,  complications 4%

 

Surgical excision

 

Quraishi et al Spine J 2017

- 84 patients mean age 21

- 12% enbloc resection

- 82% intra-lesional resection

- 7% recurrence, all with intra-lesional resection