Bibliographic record
Abstract
Total knee replacement is one of the most successful procedures in orthopaedic surgery. Although originally limited to more elderly and less active individuals, the inclusion criteria for TKA have changed, with ever younger, more active and heavier patients receiving TKA. Currently, wear debris related osteolysis and associated prosthetic loosening are major modes of failure for TKA implants of all designs. Initially, tibial components were cemented all-polyethylene monoblock constructs. Subsequent long-term follow up studies of these implants have demonstrated excellent durability in survivorship studies out to twenty years. Aseptic loosening of the tibial component was one of the main causes of failure in these implants. Polyethylene wear with osteolysis around well fixed implants was rarely (if ever) observed. Cemented metal-backed nonmodular tibial components were subsequently introduced to allow for improved tibial load distribution and to protect osteoporotic bone. Long-term studies have established that many one-piece nonmodular tibial components have maintained excellent durability. Eventually, modularity between the polyethylene tibial component and the metal-backed tray was introduced in the mid-80s mainly to facilitate screw fixation for cementless implants. These designs also provided intra-operative versatility by allowing interchange of various polyethylene thicknesses, and to also aid the addition of stems and wedges. Other advantages included the reduction of inventory, and the potential for isolated tibial polyethylene exchanges as a simpler revision procedure. However, since the late 19809s, the phenomena of polyethylene wear and osteolysis have been observed much more frequently when compared with earlier eras. The reasons for this increased prevalence of synovitis, progressive osteolysis, and severe polyethylene wear remain unclear, but it is likely associated with the widespread use of both cementless and cemented modular tibial designs. Backside wear between the metal tray and polyethylene has been implicated. Recent RSA studies comparing fixation of all-polyethylene to modular components has shown that their RSA migration patterns are superior and fixation is in fact better with the all-polyethylene construct. Further, in a recent meta-analysis, all-polyethylene components were equivalent to metal-backed components regarding revision rates and clinical scores. The promise of modular tibial components affording a simple liner exchange to revise a knee has not borne out in the literature. Several studies have revealed that the effectiveness of isolated tibial insert exchange in revision TKR is of limited value. Isolated tibial insert exchange led to a surprisingly high rate of early failure. Tibial insert exchange as an isolated method of total knee revision should therefore be undertaken with caution even in circumstances for which the modular insert was designed and believed to be of greatest value. Because of the modularity, extra materials, and extra processing, modular tibial components are significantly more expensive than all-polyethylene components.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.000 | 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 teacher head, 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".