Taper Junction Subsidence Occurs in Modular Tumor Endoprostheses: How Concerned Should We Be?
Notice bibliographique
Résumé
BACKGROUND: Advancements in musculoskeletal oncologic treatment have allowed for longer survival of patients with malignant bone tumors and the associated longer use of tumor endoprostheses in those who have had such reconstructions. Several studies have reported on increased serum metal ions with the use of such implants. Modularity in these implants introduces the risk of taper junction corrosion and subsidence resulting in metal wear particle release that may cause an adverse local tissue reaction or systemic toxicity. Additionally, these implants contain a large surface area of cobalt and chromium. It is unclear whether the source of the increased serum ion levels was due to the taper junction corrosion or the implant itself. To our knowledge, no prior study has reported on taper junction subsidence. QUESTIONS/PURPOSES: In this study we sought (1) to determine survivorship free from radiographic taper junction subsidence in a femoral modular tumor endoprosthesis, and (2) to identify the implant characteristics in the endoprostheses associated with taper subsidence. METHODS: Between January 1996 and February 2020, the senior author performed 150 proximal or distal femur replacements following resections of soft tissue or bone tumors of the thigh and femur. Of those, 6% (9 of 150) of patients were lost to follow-up before 2 years, 25% (37 of 150) could not be analyzed due to absence of plain radiographs during follow-up, and 13% (20 of 150) died before 2 years follow-up, leaving 56% (84 of 150) for analysis in this retrospective study, with a median time for analysis of 14 years (range 2 to 31 years) after the index resection and endoprosthetic reconstruction for patients with distal femur replacements and 5 years (range 2 to 19 years) for patients with proximal femur replacement. Radiographs involving the entire implant were evaluated for the presence or absence of subsidence of the taper junction that was evident and clear to see if present. The association between the number of taper junctions, the length of resection, the number of collapsed junctions, and the time to collapse from the initial surgery were examined using regression analysis. RESULTS: Overall, 14% (12 of 84) patients with a distal femur replacement had radiographic collapse of at least one of the modular tapers. Survivorship free from taper subsidence was 91% (95% CI 86% to 96%) at 10 years and 84% (95% CI 78% to 90%) at 20 years. All patients were in the distal femur replacement group. The median follow-up of patients with subsidence was 15 years (range 5 to 26). Fifty-eight percent (7 of 12) of patients had two junctions involved, 25% (3 of 12) had three junctions, and 17% (2 of 12) had one junction involved. All but one patient had subsidence in a single junction. The median time to subsidence was 15 years (range 4.5 to 24.0 years). The subsidence was progressive in all patients who demonstrated it. The taper junction subsidence was complete in 75% (9 of 12) of patients and partial in 25% (3 of 12). Univariate and multivariable regression analyses did not show that the risk factors we studied were associated with subsidence. Two patients with junction subsidence were revised, one for taper fracture and one during busing exchange for distal junction subsidence. CONCLUSION: Taper damage with late and progressive subsidence of the intervening junction is not uncommon after distal femur replacement. The impact of such a complication is still unknown. Further studies should examine the long-term outcomes and correlate them with metal ion levels. LEVEL OF EVIDENCE: Level III, therapeutic study.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,005 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».