Second-Generation Onlay Patellofemoral Prostheses: 14-Year Outcomes Redefining Isolated Patellofemoral Osteoarthritis Management
Bibliographic record
Abstract
Background: Isolated patellofemoral osteoarthritis is a frequent source of anterior knee pain in middle-aged patients. Second-generation onlay patellofemoral prostheses were developed to address limitations of earlier designs and improve clinical outcomes. Methods: We conducted a retrospective study of 231 patients (mean age 52.2 years) who underwent patellofemoral arthroplasty with a second-generation onlay implant between 2009 and 2023. Clinical outcomes were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index and Kaplan-Meier survival analysis. Radiological evaluation included signs of loosening, progression of tibiofemoral osteoarthritis, and patellar alignment. Results: < .001). The implant survival rate was 96.6% at the final follow-up. Early clinical gains were significantly influenced by implant type, while long-term outcomes were associated with patient-specific factors such as body mass index and activity level. Radiological progression of tibiofemoral disease was observed in 6.1% of patients. Conclusions: Second-generation onlay patellofemoral prostheses yield sustained functional improvement and low complication rates when used in carefully selected patients. These findings support their use as a reliable solution for isolated patellofemoral osteoarthritis. Level of Evidence: III.
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) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".