GIF89aì>³™

INTRODUCTION

PELVIC BONE ANATOMY

CLASSIFICATION OF PELVIC RESECTIONS

SURGICAL OPTIONS FOR THE PERIACETABULAR RESECTION

Hemipelvectomy

Arthrodesis

Megaprosthesis

THE SADDLE PROSTHESIS

Historical Perspectives: The Mark I

Mark II Prosthesis

Periacetabular Reconstruction Prosthesis (PAR)

INDICATIONS

SURGICAL TECHNIQUES AND CONSIDERATIONS

The Notch Osteotomy

Soft Tissue Tension

NORMAL POSTOPERATIVE IMAGING

COMPLICATIONS AND IMAGING

Mark I

Mark II

PAR Page 1

PAR Page 2

RECOVERY AND FUNCTIONALITY

CONCLUSION

REFERENCES

The Mark II Prosthesis

A newer system, named the Mark II (Link America),¹⁴ was created and was used to treat acetabular tumors in the late 1980's. This design has been the most commonly placed saddle prosthesis for neoplastic lesions, although the total number is still probably not many more than 100 insertions (per the data reported).^{1,3,5,8,13,16}

ª Saddle rests on polyethylene sleeve which rotates on peg attached to a base component

ª Base components available in differing lengths(60 to 160mm) to accommodate bone loss or patient variability (base is attached to femoral stem)

ª Set screw is used to prevent base/saddle dislocation

ª Locking pin within conical portion of base for rotational stability¹⁵

Note the swivel points. This allows for greater functionality¹⁵

By attempting to restore the iliofemoral weight bearing axis, this new saddle prosthesis achieved three objectives¹³

1- Stable reconstruction without leg length discrepancy

2- Early weight-bearing without pain

3- Satisfactory results (to be discussed later)

Axial CT, normal findings. Ilium rests between both saddle prongs¹⁵

Previous      Next

Mark II Illustration¹⁵

Note how saddle cradles ilium¹⁵

Options¹²

F