A RARE CASE OF FRACTURE

OSTEOCHONDROMA

A 14 year old , boy presented to our out patient department with pain in his right thigh following a fall from bench when pulled by a fellow classmate 2 days prior to the time of presentation.

On physical examination there was slight edema over the distal & medial aspect of right thigh & tenderness with palpation over a bony hard swelling.

Knee range of movements were painful and restricted

Neurovascular examination revealed no abnormality

X RAY WAS TAKEN

Direct radiography revealed fracture through the stalk of a pedunculated osteochondroma situated posteromedially.

When a detailed history was taken the patient revealed that he has noticed a swelling in medial aspect of lower right thigh about 4 years back , which did not show any s/o increase in size since then.

Patient also revealed that he used to have pain in the region of swelling upon prolong excertion.

What next????????????????

Leave i t o r exc i se the f rac tured f ragment??????????

We decided to excise the fractured fragment.

For excision anteromedial approach was adopted.

Fractured exostosis fragment extracted out extraperiosteally in Toto with intact cartilaginous cap

Specimen was then sent for histopathological examination

Recuperating period was uneventful & patient resumed his pre traumatic state in 2 weeks

POST OPERATIVE RADIOGRAPH

HISTOPATHOLOGY

Can give rise to 2 malignant conditions

1.Osteosarcoma---- extremely rare

2.Chondrosarcoma--- 1-2% of cases osteochonroma is most common precursor lesion

for secondary chondrosarcoma

Increase in ca rt i l ag inous cap th i ckness- s/o ma l ignancy

But in skeletally immature individual look for additional features

1. Recent increase in size2. Irregular mineralization3. Soft tissue bands4. Grossly irregular surface5. Cystic changes6. Loss of architecture of cartilage7. Myxoid changes8. Necrosis9. Inc cellularity10.Mitotic activity11.Atypia

WHO CLASSIFICATION

“Defined as a cartilage capped bony projection arising on externalSurface of bone containing a marrow cavity that is continuous with That of underlying bone.”

Mc benign tumor3% general population30% of all benign tumor10-15% of all bone tumors15% of osteochondroma occur in HEREDITARY MULTIPLE OSTEOCHONDRAMATOSIS

LOCATION(common)

BONE PERCENTAGE

Femur 34

Humerus 18

Tibia 15

Pelvis 8

Scapula 5

Ribs 3

UNCOMMON SITES (17%)• Metacarpals• Condylar process of the mandible• Base of the skull• Talus• Calcaneus • Spine • Distal end of the clavicle

TYPES

TYPE SESSILE PEDUNCULATED

Incidence Uncommon Common

Location Proximal humerus and scapula

Knee , hip and ankle

Appearance Flat plateau like stalk producing a broad based protuberance

• Elongated bony stalk merging with the host bone

• The hyaline cap is lobulated giving its appearance

SESSILE VARIANT

Solitary Osteochondroma Lateral radiograph of a sessile osteochondroma of the distal femur.

EPIDEMIOLOGY

Usually in adolescent/children rarely in infants/newbornsNo sex predilection (exception HMO)

CLINICAL FEATURES

Usually asymptomatic and an incidental finding

Significant symptoms occur as a result of complications

COMPLICATIONS COMPLICATION PERCENTAGE

Fracture 7

Deformity 23

Vascular injury 7

Neurological compromise 10

Adventitious bursae formation 27

Mechanical irritation 10

Malignancy ( Solitary / HME ) <1 , > 10

Fracture of osteochondroma

Well established yet uncommon

Most often a/w traumaReported incidence – 4 in 727- dahlin et al 5 in 70- theodorous

At most risk- proximal tibial > distal femur

Natural course1.Fracture union2.Regression / Resorption3.Non union

RADIOLOGICAL FEATURES

Plain radiograph

Stalk of a flat protuberance emerging from the surface of the boneOn occasions , it ends up as a hook like formation

Benign vs ma l ignant ????

CT very accurate for defining osteochondroma

Osteochondroma vs osteosarcoma

Reliability of ct in diagnosis of osteosarcoma

USGExamination of choice – suspecting vascular lesions

Accurate method for examining cartilaginous cap of osteochondroma

Only way to pin point bursitis

MRIMost precise imaging method for symptomatic causes of bone masses

Differentiate osteochondroma from other surface bony lesions.

Cartilaginous caps- T2WI- high T1WI-low

Perichondrium

High signal in T1WI-------

High signal in T2WI-------

False positive results in ?

Benign vs ma l ignant

Challenge but accurately diagnose

Osteosarcoma>2cm in adult>3cm in children

ChondrosarcomaLow T1 signal after IV contrast infusion- rare in benign lesions

MRI IS GOLD STANDARD FOR DIAGNOSIS OF MALIGNANT TRANSFORMATION

NUCLEAR MEDICINE

Examine the metabolic activity of tumor

Thallium 201 – used for malignant transformation

ANGIOGRAPHY

Vascular lesions

Neovascularization of cartilaginous cap

s.no Author Group Conclusion

1 Shapiro et al 22 pt with HME 2.7 surgery for deformity correction

2 Wirganowicz 285 cases of benign exostosis

Elective excision – 12.5% cases a/w complications

3 Canelle et al 408 cases of exostosis

Malignant transformation riskMultiple exostosis-13%Solitary-cannot be determine

4 Saglik et al 382 cases of oc Essential to reconstruct the mass as well as reconstruct the deformities

5 Bottner et al 86 symptomatic oc Post operatively93.4%- preoperative symptoms resolved4.7%- complications7%- minor compplications5.8%- local recurrence

s.no Author Group Conclusion

6 Vasseur & fabre 97 cases with vascular complications

66%-solitaryProphylactic resection if the tumor is present in the vicinity of the vessels

7 Garrison et al 75 cases of osteosarcoma having arisen from oc

1.Excision- 78% recurrence2. Resection- 15% recurrence3. Amputation

8 Pierz et al 43 cases of HME 27of 43 required about 1-5 surgeries to control their lesions

9 Shin et al 29 pts of HMO In young pts simple excision o tumor improve range of movements o forearm but it cannot control the progress o the disease

CONCLUSION

The treatment of choice for osteochondroma is surgical .

The tumor should be excised when symptoms or complications have presented.

A prophylactic resection is suggested only if the lesion lies next to a vessel.

An osteochondroma must be completely excised, without leakage of myxomatous tissue or part of the cartilaginous cap, especially when a

sarcomatous change is suspected.

In addition to resection, reconstructive techniques have to be undertaken.

Chemotherapy and radiotherapy are suggested in dedifferentiated tumors.

Thank you & have a cheerful evening