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Purpose::
Revision hip arthroplasty is a very challenging procedure. Use of a modular distal fixation stem is one of the available options for revision arthroplasty in patients with proximal femoral bone deficiency. The purpose of this study was to evaluate mid- to long-term outcomes of cementless modular distal fixation femoral stem implantation...
Context in source publication
Context 1
... subsidence greater than 5 mm was not seen. Ten hips (21%) showed a radiolucent line on Gruen zones I or VII. 12 In 32 hips (75.0%), stress shielding was observed in the proximal part of the femur (Table 3). A partial pedestal reaction around the distal stem was observed in three hips. ...
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Trunnionosis is emerging as an early mode of failure in conventional metal-on-polyethylene total hip arthroplasty. It is defined as wear or corrosion at the trunnion, the taper at the femoral head-neck interface. Trunnion wear can result in a variety of negative sequelae and, in severe cases, necessitate revision arthroplasty. We describe a 64-year...
Citations
... Clinical scores, presence of thigh pain, and radiographic results were assessed in 66 hips without femoral re-revision. The mean duration of follow-up was 16 years (range, [10][11][12][13][14][15][16][17][18][19][20][21][22][23]. ...
... Favorable mid-term to long-term results for this stem have also been reported by other researchers. Perticarini et al [23] reported 92.3% stem survivorship at a mean follow-up of 6.8 years (range, [5][6][7][8][9][10][11][12][13][14][15][16], and Kang et al [21] reported 97.6% survivorship at 7.9 years (range, 6-10). Comparable results were obtained using different but similarly tapered and fluted modular stems. ...
Background
Tapered modular stems are increasingly used in revision total hip arthroplasty (THA) with deficient femoral bone stock. This study aimed to report the long-term outcomes of revision THA using a tapered and fluted modular stem.
Methods
Between December 1998 and February 2006, 113 revision THAs (110 patients) were performed with a tapered and fluted modular stem at a single institution. Hip radiographs were used to identify stem subsidence, stability, and femoral radiolucency. Final outcomes were assessed in 72 hips (70 patients), with a minimum follow-up of 10 years.
Results
The mean follow-up duration was 16 years (range, 10 to 23). At the final evaluation, the Harris hip score improved from a mean of 41 points (range, 10 to 72) preoperatively to 83 points (range, 56 to 100) (P<0.001). Six femoral re-revisions were performed for the following reasons: one aseptic loosening, two stem fractures, and three infections. One stem fracture occurred at the modular junction after 14 years, and the other at a more distal location after 15 years. Stem subsidence was greater than 5 mm in six hips (9.1%), but secondary stability was achieved in all stems. Osseointegration was observed in 63 (95.5 %) hips. Stem survivorship was 91.1% with an endpoint of any re-revision and 94.6% for aseptic re-revision.
Conclusion
A tapered and fluted modular stem demonstrated excellent implant survivorship with reliable bony fixation at a mean follow-up of 16 years. This type of stem can be a durable option for revision THA in patients who have femoral defects.
... after a mean follow-up of 8-15.8 years. [4][5][6][7][8][9][10] Nevertheless, clinical data indicated a worse outcome with increasing sizes of femoral bone defects. 1,7,10 Insufficient primary stability and excess interfacial movements between the implant and the bone are known to inhibit adequate osseous integration of the implant. ...
... Based on studies with animals and human osteoblasts, relative implant-bone micromotions below 100 mm seem to be a prerequisite for osseous implant integration. [11][12][13] Although primary stability is an essential point when using uncemented revision stems, the recommendations concerning the necessary minimum lengths of sufficient implant-bone anchorage differ widely, ranging from 2 cm, 14 3-4 cm, 15,16 4-6 cm, 4 and about 7 cm or 2 femoral diameters 5,17,18 up to 8-12 cm. 19 Previous experimental studies addressing this issue often focused on specific single aspect such as axial or rotational stability and smaller bone defects. ...
Purpose:
Cementless modular fluted hip stems are commonly used in revision arthroplasty. Nevertheless, there is a wide spectrum of recommendations concerning the minimum bone stock required to enable osseous ingrowth and implant-bone micromotions <100 µm. This experimental study investigated the primary stability of a tapered cementless fluted revision stem depending on different types of bone defects.
Methods:
Implant-bone interface movements with a bimodular stem were examined under cyclic axial and torsional loading using composite femora. In four degrees of freedom, the implant subsidence and micromotions were captured with linear variable differential transformers for the intact femora and seven different defects ranging from Paprosky type I to type IIIB.
Results:
With a 7-cm length of intact diaphysis proximal to the isthmus (Paprosky IIIA), mean implant-bone micromotions of 66 µm occurred. An implant-bone contact zone of only 5 cm (Paprosky IIIA) resulted in micromotions notably over 100 µm and significantly increased subsidence (p < 0.05). With a Paprosky IIIB defect (3 cm of intact diaphysis) rotational instability occurred in all specimens.
Conclusions:
Aside from critically increased interfacial micromotions (>100 µm), rotational instability emerged as a mechanism of fixation failure when the implant-bone contact zone was only 5 cm or less. Hence, future studies investigating the implant fixation in the case of femoral bone defects should consider both axial and torsional loading. With regard to the clinical application, our data suggest maintaining 7 cm of diaphyseal implant-bone contact for a safe anchorage of cementless fluted hip revision stems.
Résumé
Introduction
La reprise des descellements fémoraux de prothèse de hanche nécessite une analyse minutieuse des pertes de substance osseuse pour décider de la prise en charge la plus adaptée. Les tiges modulaires posent le problème du risque de rupture d’implant et de corrosion de la zone de jonction. Elles ont rarement été évaluées en fonction du stade de perte osseuse et notamment sur des pertes de substance peu évoluées. Nous avons mené une étude rétrospective afin d’étudier pour une tige modulaire fémorale en fonction de la perte osseuse initiale (stade IIIb versus les stades inférieurs) selon Paprosky : 1) le taux de survie, 2) l’ostéo-intégration, les enfoncements, les fractures et les ruptures d’implants.
Hypothèse
La modularité n’est pas exclusivement réservée aux pertes osseuses IIIb, mais elle est applicable pour tous types de pertes osseuses avec un taux de complication identique.
Patients et méthode
Nous avons inclus 163 patients entre le 1er janvier 1996 et le 31 décembre 2016 qui ont eu un pivot modulaire fémoral de reprise. Le suivi minimum était de 4 ans et moyen de 6,67ans ± 3,275 [4–21]. Un patient a été considéré comme perdu de vue, 88 étaient décédés au suivi, 74 patients étaient vivants mais 10 d’entre eux ont eu leur tige initiale retirée à moins de 4 ans de recul. Soixante-quatre patients ont bénéficié d’une évaluation clinique. Nous avions 44,17 % (72 cas) de Stade IIIb selon la classification de Paprosky et 55,83 % de stades cumulés I-II-IIIA (91 cas). L’ostéo-intégration de la tige a été évaluée selon le score d’Engh et Massin et toutes les complications ont été recherchées.
Résultats
La survie de la tige fémorale était de 93,75 % (95 %CI : 83,33–96,70) à 5 ans en considérant le retrait quelle que soit la cause. Il n’y avait aucune différence significative (p = 0,0877) en fonction de la perte osseuse initiale sur la survie de l’implant : 89,84 % (95 %IC : 78,73–95,31) pour le stade IIIB ; 95,23 % (95 %IC : 82,24–98,79) pour le stade IIIA ; 97,06 (95 %IC : 80,90–99,58) pour le stade II. Les 2 ruptures d’implants observées étaient dans des stades IIIB, soit 2/66 dans le stade IIIB et 0/86 dans les stades inférieurs (p = 0,188)
Conclusion
La modularité donne des résultats similaires quel que soit le stade de la perte osseuse initiale sans risquer de développer plus de complications.
Niveau de preuve
IV, Étude rétrospective.
Introduction:
Revision for loosening of femoral stems requires an extensive analysis of bone defects to determine the most appropriate course of action. The drawbacks of using modular stems are that they can break or corrode at their junction. They have rarely been evaluated based on the extent of bone loss and particularly in patients with less severe bone loss. This led us to carry out a retrospective study to analyze modular femoral stems as a function of the initial bone defect (stage IIIB versus less severe in the Paprosky classification): 1) implant survivorship, 2) osteointegration and subsidence of the stem, and 3) breakage of implant.
Hypothesis:
Modular femoral stems can be used for all types of bone defects (not only IIIB) as the complication rate is identical.
Patients and methods:
Between January 1, 1996, and December 31, 2016, 163 patients were included who had received a modular femoral revision stem. The minimum follow-up was 4 years; the mean was 6.7 years±3.3 [4-21]. One patient was lost to follow-up, 88 had died before the analysis date and 74 were still alive; however, 10 of them had the stem removed less than 4 years after implantation. Thus 64 patients were available for the clinical evaluation. There were 44% (72 patients) with Paprosky stage IIIB femoral bone loss and 56% (91 patients) with stage I, II or IIIA bone loss. The stem's bone integration was evaluated using the Engh and Massin score. All complications were documented.
Results:
The survivorship of the femoral stem was 93.75% (95% CI: 83.33-96.70) at 5 years with removal for any reason as the end point. There was no significant difference (p=0.0877) in survivorship relative to the severity of the initial bone loss: 89.84% (95% CI: 78.73-95.31) for stage IIIB; 95.23% (95% CI: 82.24-98.79) for stage IIIA; 97.06% (95% CI: 80.90-99.58) for stage II. Bone integration was considered as being achieved in 76% of stems based on available radiographs (119 of 156 patients) with the severity of bone loss having no effect. We found 18 instances of stem subsidence out of 156 stems with available data (11.5%). The mean subsidence was 14.7 mm ± 12.3 [5-40]. Among the 18 stems with postoperative subsidence, 13 had been implanted for stage IIIB defects, while 5 were for less severe defects (p=0.751). Two stem fractures occurred in patients with stage IIIB bone loss, thus 2/66 for stage IIIB and 0/86 in the less severe bone loss cases (p=0.188).
Conclusion:
Modularity provides similar results no matter the severity of initial bone loss, without the risk of additional complications.
Level of evidence:
IV, Retrospective study.
Introduction
Diaphyseal fixation remains the mainstay of revision THA. The stability of diaphyseal fixation can be quantified by the extent of contact between the stem and the endosteal cortex. This is highly affected by the morphology of the proximal femur. The purpose of this study was to examine factors affecting diaphyseal contact in the revision THA and to identify preoperative predictors of adequate fixation.
Methods
Three-dimensional femur models were created from CT scans of 33 Dorr B and C femora. The proximal 120mm of the femur was omitted to mimic proximal bone deficiency. A tapered fluted stem (3 degrees, 150 mm) model was virtually implanted after reaming of the medullary canal. The contact length between stem and endosteal cortex was measured, in addition to other variables. The relationship between variables was evaluated using Spearman’s correlation and logistic regression analysis was used to identify predictors of the contact length (p<0.05).
Results
The contact length varied widely between specimens (66.5±16.6mm, range: 21-98mm). Contact increased with the depth of the isthmus below the lesser trochanter (range: 55-155 mm; r²=0.473, p=0.005) and the distance between the isthmus and the distal edge of the damage zone (range: -9 - 96mm; r²=0.508, p=0.002). Stepwise regression identified the reaming length, distance between fracture and the isthmus, and isthmus diameter as independent predictors of contact length (r= 0.643).
Conclusions
Contact is limited in specimens where the isthmus is more proximally located. In these cases, supplementary fixation using plating and/or longer, curved prosthesis may be considered.
Background: Revision of a failed total hip arthroplasty (THA) poses technical challenges. The use of primary stems for revision can be advantageous for maintaining bone stock and reducing complications: small case series have reported promising results in the short-term to mid-term follow-up. The aim of this study was to evaluate the long-term clinical and functional results and survivorship of a consecutive series of THA femoral component revisions using a conical primary cementless stem (PCS).
Methods: Ninety-four stem revisions with a preoperative Paprosky I or II defect were analyzed at an average follow-up of 12.7 ± 5.4 years. Aseptic loosening was the reason for revision in 92.5% of cases. Twenty patients were lost to follow-up. Two subgroups were created: Group 1 (n 1⁄4 59) underwent isolated stem revision; Group 2 (n 1⁄4 15) underwent complete THA revision. All were evaluated preop- eratively and postoperatively based on the Harris Hip Score (HHS), the Western Ontario and McMaster Universities Index (WOMAC) score, and the visual analog scale for pain (VAS). Residual trochanteric pain and length discrepancies were recorded. Radiographic evaluation included signs of osteolysis, subsi- dence, loosening, and heterotopic ossification.
Results: PCS survivorship was 100% at 5 years and 95.9% at 10 years. Overall, significant postoperative improvements (P < .01) were observed on the HHS (44.3 vs 86.9), WOMAC (42.8 vs 82.8), and VAS (7.0 vs 3.0). Postoperative scores on all scales were higher for Group 1 (P < .01). Three patients (4.1%) underwent further stem revision. Demarcation lines (1 mm) were found in 12 (16.2%) patients and significant heterotopic ossifications in 22 (29.7%).
Conclusion: The use of PCS for stem revision in failed THA with a limited femoral bone defect is a reliable option for both isolated stem revision and concomitant cup revision in well-selected patients.
Introduction
Both modular and monoblock tapered fluted titanium (TFT) stems have gained popularity over fully porous coated cylindrical (FPCC) femoral stem designs, but limited data exists comparing subsidence rates following revision total hip arthroplasty (THA). The purpose of this study was to determine differences in subsidence and clinical outcomes among 3 revision femoral stem designs.
Methods
We reviewed a consecutive series of 335 patients who underwent femoral component revision to a cementless modular TFT (n=225), monoblock TFT (n=63), or FPCC (n=47) stem between 2012-2019. We evaluated radiographic subsidence rates, re-revision rates, and patient reported outcomes between the three stems. A multivariate regression analysis was performed to determine the independent effect of stem type on the risk of subsidence >5mm.
Results
At an average follow-up of 39 months (range, 12 to 96 months), there were no differences in mean subsidence rates (3.5 vs. 2.4 vs. 2.1 mm, p=0.14), HOOS Jr. scores (78 vs. 74 vs. 64 points, p=0.15), or aseptic re-revision rates (4% vs. 3% vs. 0%, p=0.29) between modular TFT, monoblock TFT, and FPCC stems. Although modular TFT stems were more often used in patients with extensive femoral bone loss (Paprosky III and IV), there were no differences in subsidence rates >5mm among the three stems (p>0.05) in multivariate analysis.
Conclusion
Modular TFT, monoblock TFT, and FPCC femoral stem designs all perform well in revision THA with no difference in clinical outcomes or subsidence rates. Surgeons should select the stem for which they feel is the most clinically appropriate.
