Histopathologic Retrieval Analysis of Clinically Failed Porous Tantalum Osteonecrosis Implants
Bibliographic record
Abstract
BACKGROUND: An Osteonecrosis Intervention Implant made of porous tantalum was recently developed to provide structural support and a compatible surface for tissue ingrowth in osteonecrotic femoral heads. From an investigational device exemption study that comprised 113 implants, we carried out a retrieval analysis of clinically failed implants. METHODS: Seventeen porous tantalum implants that had been used for the treatment of Steinberg stage-II osteonecrosis of the hip were retrieved at the time of conversion to a total hip arthroplasty. Fifteen implants that had been transected near the base of the femoral neck with the proximal portion left in situ within the femoral head underwent histopathologic analysis at an average of 13.4 months (range, three to thirty-six months) after implantation. RESULTS: Residual osteonecrosis was present in fourteen of the fifteen specimens. Fracture of the subchondral bone of the femoral head was present in all instances, and collapse of the femoral head was present in nine instances (60%). Backscattered scanning electron microscopy confirmed the presence of bone ingrowth in thirteen (87%) of the fifteen specimens. The mean extent of bone ingrowth was 1.9% (range, 0% to 4.4%). CONCLUSIONS: The retrieved implants were associated with little bone ingrowth and insufficient mechanical support of subchondral bone. The implant design, the surgical technique, its application, and the clinical characteristics of candidates for this procedure should continue to be monitored closely.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".