The additional tibial stem extension is not mandatory for the stability of 5 mm metal block augmented tibial prosthesis construct in primary total knee arthroplasty: 5-year minimum follow-up results
Bibliographic record
Abstract
PURPOSE: To determine whether additional stem extension for stability is necessary, we performed mid-term follow-up of patients who had been managed with 5-mm metal block augmentation for a tibial defect, where tibial prosthesis was fixed using bone cement without stem extension. Also, we evaluated clinical and radiologic results including survival rate of patients without stem extension. METHODS: We retrospectively analyzed patients with tibial bone defect, had undergone primary total knee arthroplasty, and had been treated with 5-mm metal block augmentation without stem extension between March 2003 and September 2013. Among 74 patients (80 cases), 47 patients (52 cases) were followed up for at least 5 years. RESULTS: Mean flexion contracture improved from 8.8° (0-40°) preoperatively to 0.4° (-5° to 15°) at final follow-up (P < 0.01), but there was no significant change in the mean angle of great flexion: 124.6° (75-150°) preoperatively and 126.2° (90-145°) at final follow-up (P = 0.488). Mean range of motion improved from 115.8° (35-150°) preoperatively to 125.5° (90-145°) at final follow-up (P < 0.01). Mean knee score improved from 38.7 points (0-66 points) preoperatively to 93.2 points (79-100 points) at final follow-up (P < 0.01), and mean functional score also improved from 50.4 points (10-70 points) preoperatively to 81.8 points (15-100 points) at final follow-up (P < 0.01). The mean postoperative Western Ontario and McMaster University osteoarthritis score was 19.5 points (0-66.0 points). The mean femorotibial angle was corrected from 9.0° varus (23.0° varus-6.3° valgus) preoperatively to 5.5° valgus (2.2° varus-11.1° valgus) at final follow-up (P < 0.01). There was no change in the mean β-angle, which was 90.7° (87.2-94.9°) immediately postoperative and 90.8° (87.2-94.9°) at final follow-up (P = 0.748) and in the mean δ-angle, which was 86.2° (81.3-90.0°) immediately postoperative and 87.2° (83.1-96.5°) at final follow-up (P = 0.272). Radiolucent lines (RLL) were observed in ten cases (26.3%), and the mean RLL scores at final follow-up were 0.34 points (0-3 points) in the anteroposterior view and 0.42 points (0-6 points) in the lateral view. Scores for the RLL were ≤ 4 points in 36 cases, 5-9 points in two cases. Revision surgery due to aseptic loosening (three cases) is rarely required, and the Kaplan-Meier survival rate at 10 postoperative years was 96.4% CONCLUSION: When performing 5-mm metal block augmentation for a proximal tibial defect, no additional tibial stem extension can be a good surgical option for the stability of tibial prosthetic construct and mid-term clinical and radiologic results. LEVEL OF EVIDENCE: IV.
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 | 0.006 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".