Case Presentation

December 19, 2007

•21 y.o. male

•CC: Right leg pain

•HPI: 1 year ago had surgery for a “tumor” on right leg. “Replaced my shin bone. But I don’t remember what they called it.”

•PMH/PSH: as above•NKDA•Meds: None•SHx: denies ETOH, TOB or illicit drug use, recently discharged from the Navy, swims for exercise, BA in nursing but currently on disability

•FHx: N/C

•Pertinent Positives:– Well-healed scars on right shin, including

skin graft site mid-shaft– Intact neurovascular exam

•Imaging:

Plain XR

Allograft Nonunion

• 8 – 17% reported • Lack of host-donor junction @ 1 year• Union = gap obliterated or bridging bone @ 3 or

greater cortices on AP and Lateral imaging• Worse outcomes if:

– Adjuvant chemotherapy– Adjuvant radiation– Infection – usually occurs in 1st year– Fracture – usually occurs in first 3 years– Original disease stage II or III (MTS)– Allograft is part of arthrodesis procedure

Allograft Nonunion

Retrospective review 945 allograft patients:– 163 nonunion (17.3%)

No chemo, no XRT 11.3% XRT only 18% Chemo 27%

– 162 revised: 47% required further procedures for nonunion 49 ultimate failures required metallic prosthesis,

replacement of allograft or amputation

Menken HJ et al, CORR 2001; 382: 87-98.

Allograft Nonunion

• 718 patients observed greater than 2 years:– 75% retained and successful for >20 years– 17% nonunion– 11% infection– 19% fracture– 6% unstable joint

• Of the failed allografts:– >85% of the failures due to infection, fracture,

recurrence of primary tumor– Susceptibility to infection primarily in 1st year– Susceptibility to fracture in first 3 years

Menken HJ et al.; CORR, 1996; 324:86-97.

Adamantinoma

•0.4 - 1% of all primary bone tumors

•2nd & 3rd decade; range 3-86 yrs

•Pain, swelling in adolescent or young adult

•85 – 90% tibial shaft– 10% of these ipsilateral fibula– Femur, humerus, ulna, radius, hands/feet

Adamantinoma

• Mets in 12-29%– Lung, bone, regional lymph nodes– Mortality 13-18%– Survival with metastatic disease ~ 13 yrs

• Risk factors:– Intra-lesional treatment– Male– Short duration of symptoms– Young age on presentation (<20 yrs)– Lack of squamous differentiation of tumor

Adamantinoma - XR

• Eccentric, cortical, diaphyseal, long bone• Sclerotic edge slowly growing lesion• Slight expansion of cortex with thinning• Cystic or multiloculated appearance• Lack of periosteal reaction, even in presence

of extensive cortical destruction• Two most characteristic features:

– Location in tibia– Intracortical involvement

Adamantinoma

•MRI:– T1 – isointense, enhances with

gadolinium– T2 – hyper-intense

Histology

-Basiloid cells, pseudoglandular pattern and peripheral palisading, characteristic of anadamantinoma

MTS SystemStage Grade* Site† Metastasis‡I A G1 T1 M0

B G1 T2 M0

II A G2 T1 M0

B G2 T2 M0

III G1 or G2 T1 or T2 M1

*G1 = low grade and G2 = high grade.

†T1 = intracompartmental and T2 = extracompartmental.

‡M0 = no regional or distant metastasis and M1 = regional or distant metastasis.

AJCC Staging System

Stage A/B Size Node Metastases Grade

I AB

</= 8 cm> 8 cm

None N0 None M0 G1-2 (Low)

II AB

</= 8 cm> 8 cm

None N0 None M0 G2-3/G3-4 (High)

III Any None N0 None M0 G2-3/G3-4 (High)

IV AB

Any None N0Present N1

M1aM0 or M1b

Any