The patient was a 53-year-old female who presented with right hip pain. Imaging and biopsy confirmed Chondrosarcoma involving the right hemipelvis, with tumor extension to the SI joint, requiring a combined Type I + II pelvic resection. Preoperative planning focused on achieving wide oncologic margins and restoring pelvic stability.

Dr. Sadegh Saberi

• Orthopaedic Oncologist
• Associate Professor of Orthopaedic Surgery
• Tehran University of Medical Sciences (TUMS)

Pre-operative Planning

High-resolution 1-mm CT imaging was used for reconstruction and generation of the patient’s three-dimensional bony model. Preoperative planning utilized high-resolution MRI to delineate tumor margins and define the osteotomy planes. Patient-specific cutting guides were designed based on the patient’s bony anatomy to ensure precise resections. The implant geometry was derived by mirroring the contralateral healthy hemipelvis, maintaining correct acetabular version and inclination. Screw trajectories were planned for fixation to the sacroiliac joint, pubis, and ischium, and porous surfaces were incorporated to promote osseointegration. Additional holes were included for muscular reattachment. The implant was manufactured in medical-grade titanium via SLM and sterilized using gamma irradiation.

Surgical Treatment

The procedure was performed under general anesthesia. Bone cuts in the pubis and ischium were performed with the aid of a surgical navigation system, with cut locations verified according to the preoperative plan. The custom 3D-printed implant was then positioned and secured. Fixation was achieved using a combination of 6.5-mm cancellous screws into the sacrum and 4.5-mm screws in the pubic and ischial flanges, providing mechanical stability.
Soft-tissue reconstruction was performed by reattaching the abdominal musculature and gluteus muscle through dedicated holes on the implant, maintaining pelvic stability and preserving hip biomechanics.

Post-operative Follow-up

During the postoperative period, the patient received parenteral antibiotics for up to 5 days. An abduction brace was applied and maintained for 6 to 8 weeks. Mobilization was initiated with partial weightbearing, and hip range of motion exercises were started as tolerated, following the restrictions determined by the reconstruction and soft-tissue repair. Partial weightbearing was continued until early radiographic signs of osseous integration and stable implant fixation were confirmed. Weightbearing was then progressively advanced over the subsequent weeks, and strengthening of the surrounding musculature was introduced once soft-tissue healing was sufficient.
Throughout the 28-month follow-up, the patient demonstrated stable fixation and correct implant placement. The early postoperative course was complicated by a partial sciatic nerve injury, which was managed conservatively with gradual neurological improvement. No late complications were observed. PET imaging showed no evidence of disease recurrence. Rehabilitation focused on restoring hip mobility, progressive strengthening, and controlled advancement of weightbearing activities. Functional assessment using the MSTS scoring system yielded a score of 18 (60%), reflecting the patient’s early-stage recovery.

Physician’s Conclusion

The use of a custom 3D-printed pelvic implant enabled precise oncologic resection and effective reconstruction of a complex Type I + II pelvic defect involving the SI joint. The combination of preoperative planning, surgical navigation, porous bone–implant interfaces, and secure fixation using 6.5-mm cancellous screws ensured anatomical accuracy, mechanical stability, and long- term durability. In this case, the surgical navigation system helped overcome challenges associated with achieving precise tumor cuts and accurate implant placement, although it introduces additional intraoperative complexity that requires careful handling. For patients with pelvic Chondrosarcoma, where surgery remains the primary curative treatment, custom-made implants are particularly valuable. They allow restoration of pelvic anatomy and joint function while accommodating the wide resection margins necessary for oncologic control. This case also highlights the importance of multidisciplinary collaboration between orthopedic surgeons and biomedical engineers, enabling prostheses to be precisely tailored to individual anatomy while preserving key bony and soft-tissue structures. Such an approach supports both oncologic control and functional recovery in patients with extensive pelvic Chondrosarcoma.

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Right Hemipelvic Chondrosarcoma in a 53-Year-Old Patient | Dr. Sadegh Saberi