Circumferential Allograft Replacement of the Proximal Femur
Bibliographic record
Abstract
The use of proximal femoral structural allografts in revision hip arthroplasty remains controversial. The current study constitutes the mean 8.8 years followup (range, 3-12.5 years) of a consecutive series of 55 proximal femoral allografts in 51 patients. In 46 patients the implant was cemented into the allograft and the distal femur, and the host proximal femur was resected at the time of reconstruction in all but seven patients. Five patients underwent revision surgery for acetabular failure, and six additional patients underwent revision surgery for failure of the proximal femoral allograft. Three patients underwent successful revision surgery and had additional proximal femoral allografts. Failure was caused by graft fracture in one patient, by deep infection in two patients, and by junctional nonunion in three patients. Junctional nonunion was seen in five patients (9%), two of whom were treated successfully with bone grafting and bone grafting and plating, respectively. Instability was observed in six patients (11%). Trochanteric nonunion was seen in 22 patients (43%) and trochanteric escape was seen in 14 patients (27%). The mean Harris hip score improved from 39 to 79 points. Resorption involving the full thickness of the allograft in at least one zone was seen in seven patients. This progressed rapidly and silently within the first 3 years but has yet to lead to the failure of any of the reconstructions. Infection was ruled out in every case. Allograft resorption was seen in seven patients and may be related to a combination of factors. It is most likely that this is an immunologic problem of slow rejection, but it is possible that the distal cement fixation led to stress shielding and resorption attributable to mechanical disuse. The possible protective role of retaining the bivalved host bone as a vascularized onlay autograft remains to be clarified. Although these results justify the continued use of structural allografts for selected patients, continued followup is warranted.
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 | 0.003 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 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".