Custom 3D-Printed Implants Reconstruct Pelvis and Femur Destroyed by Bone Cancer

Vanishing Bone Disease Hadassah Hospital surgeons have completed what appears to be Israel's first total pelvic and femoral reconstruction using two bespoke 3D-printed implants, restoring mobility to a 24-year-old woman whose bones had nearly dissolved from vanishing bone disease. The Problem: A Diagnosis That Took Years The patient, identified as Mira, first presented as a child with an unexplained femoral fracture, one her doctors noted carried no traumatic cause. What followed was a years-long odyssey through multiple hospitals, repeated failed examinations, attempted surgeries, and a hip replacement that only accelerated the collapse. The replaced femoral head sank into the pelvis as the underlying bone reabsorbed. Her leg shortened by roughly ten centimetres. The pain became constant. She ended up in a wheelchair. The diagnosis, confirmed only after extensive genetic testing, was vanishing bone disease, a condition where the body reabsorbs bone tissue for reasons medicine still cannot explain. Few physicians encounter a single case in their entire career. The Solution: Two Custom Implants, One Unusual Decision Dr. Omer Or, an orthopedic oncologist and metabolic bone disease specialist at Hadassah Hospital Ein Kerem, took the referral. His decision was not to stabilise what remained, but to rebuild what had disappeared. The reconstruction spanned a year and multiple surgical stages. For the first operation, Dr. Or collaborated with Dr. Gurion Rivkin, director of the Joint Replacement Unit at Hadassah Hospital Mount Scopus, and surgical nurse Esti Friedlander. They designed and 3D-printed two unique implants. The first reconstructed the missing pelvic bone and hip joint. The second was a custom lengthening implant to replace the absent femur, capable of gradual extension up to five centimetres. During a complex, multi-hour procedure, the team removed the old implant, which had migrated into the pelvis after its bony support dissolved, and rebuilt the joint and femur from scratch. The hip was restored to anatomical position. The leg gained three centimetres in that single operation. Post-operatively, Mira used a home device applying gentle electric current to the lengthening site three times daily. The implant extended incrementally, originally targeting one millimetre per day over roughly fifty days for a total five-centimetre gain. Her body responded better than anticipated. The leg ultimately lengthened an additional five centimetres post-operation, bringing the total gain to eight centimetres, followed by intensive rehabilitation. A year later, the temporary lengthening implant, which wears with extended use, was swapped for a solid permanent replacement. Her leg gained one further centimetre in that final surgery. The Results: Walking Without Crutches Today, Mira walks without crutches. > "This case is unusual not only because of the rarity of the disease but also because of the innovative solution found," said Dr. Or. "It combined reconstruction of the pelvis and hip without bone, the use of a lengthening implant, and coping with a disease in which the bone itself disappears." Why This Matters for Implant Engineering Cases at this extreme sit well outside what conventional manufacturing can address. Standard implants assume standard anatomy. Vanishing bone disease leaves surgeons with almost nothing to anchor to. The Hadassah team's approach, combining patient-specific 3D-printed geometry with an integrated lengthening mechanism and post-surgical incremental extension, demonstrates a pathway for reconstructing anatomy that has effectively ceased to exist. The engineering challenge here was not merely dimensional accuracy, but designing an implant system that could function in an environment where the host tissue was actively disappearing. The lengthening mechanism had to operate without relying on stable bone interfaces. The pelvic reconstruction had to restore load-bearing geometry from near-total absence. For manufacturers of custom implants, this case pushes the boundary of what patient-specific design can achieve when paired with electromechanical lengthening technology and staged surgical planning.

M4S TAKE

My take: AI claims need scrutiny. The useful implementations reduce cycle time or defect rates in measurable ways. Vague promises about 'optimization' without specific metrics are usually marketing.

Simon McLoughlin