Modern Revision Femoral Stem Designs Have No Difference in Rates of Subsidence

BackgroundBoth modular and monoblock tapered fluted titanium (TFT) stems have gained popularity over fully porous-coated cylindrical (FPCC) femoral stem designs, but limited data exist comparing subsidence rates following revision total hip arthroplasty (THA). The purpose of this study is to determine differences in subsidence and clinical outcomes among 3 revision femoral stem designs.MethodsWe 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 and 2019. We evaluated radiographic subsidence rates, re-revision rates, and patient-reported outcomes between the 3 stems. A multivariate regression analysis was performed to determine the independent effect of stem type on the risk of subsidence >5 mm.ResultsAt 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 = .14), HOOS Jr scores (78 vs 74 vs 64 points, P = .15), or aseptic re-revision rates (4% vs 3% vs 0%, P = .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 >5 mm among the 3 stems (P > .05) in multivariate analysis.ConclusionModular 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 which they feel is the most clinically appropriate.     

Subsidence of monoblock and modular titanium fluted tapered stems in revision hip arthroplasty: A retrospective multicentre comparison study

BackgroundTapered, fluted, titanium (TFT) stems have shown good clinical outcomes in revision total hip arthroplasty (rTHA), however concerns exist regarding early subsidence. This study compares subsidence between a modern monoblock 3-degree and a modular 2-degree TFT stem in rTHA.MethodsA retrospective, international multicentre comparative study was conducted including 64 rTHA in 63 patients. A monoblock TFT stem was used in 37 cases and a modular TFT stem was used in 27 cases. Patient demographics, Paprosky femoral bone loss classification, bicortical contact and stem subsidence were recorded at minimum four week follow up.ResultsThere was no statistically significant difference in overall subsidence (p = 0.318) or the rate of subsidence >10 mm between stems. Mean subsidence was 2.13 mm in the monoblock group and 3.15 mm in the modular group. Two stems subsided >10 mm: one in each group. There was no difference in bicortical contact between groups (p = 0.98). No re-revisions were performed.ConclusionsWe found no difference in subsidence between the two stems. Surgeons may consider the use of monoblock stems in rTHA as they have comparably low rates of subsidence and eliminate the small but potentially catastrophic risk of implant fracture at modular junctions associated with modular stems.     

Long-Term Outcomes of Revision Total Hip Arthroplasty Using a Tapered and Fluted Modular Stem: A Mean Follow-Up of 16 Years

BackgroundTapered 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.MethodsBetween 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.ResultsThe mean follow-up duration was 16 years (range, 10-23). At the final evaluation, the Harris Hip Score improved from a mean of 41 points (range, 10-72) preoperatively to 83 points (range, 56-100) (P < .001). Six femoral re-revisions were performed for the following reasons: 1 aseptic loosening, 2 stem fractures, and 3 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 >5 mm in 6 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 end point of any re-revision and 94.6% for aseptic re-revision.ConclusionA 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.     

Nonmodular Tapered Fluted Titanium Stems Osseointegrate Reliably at Short Term in Revision THAs

Background

The ideal femoral component for revision THA is undecided. Cylindrical nonmodular stems have been associated with stress shielding, whereas junctional fractures have been reported with tapered fluted modular titanium stems. We have used a tapered fluted nonmodular titanium femoral component (Wagner Self-locking [SL] femoral stem) to mitigate this risk. This component has been used extensively in Europe by its designer surgeons, but to our knowledge, it has not been studied in North America. Added to this, the design of the component has changed since early reports.

Questions/purposes

We asked: (1) Does the Wagner SL stem have low rates of rerevision and other complications at a minimum 2 years after surgery? (2) Is the Wagner SL stem associated with high levels of patient function and pain relief at a minimum 2 years after surgery? (3) Does the Wagner SL stem have low rates of subsidence at a minimum 2 years after surgery? (4) Is the Wagner SL stem associated with proximal femoral bone remodeling at a minimum 2 years after surgery?

Method

Between May 2011 and December 2012, we performed 198 femoral revisions, of which 104 (53%) were performed using the Wagner SL femoral stem; during that period, our institution gradually shifted toward increasing use of these stems for all but the most severe revisions, in which modular fluted stems and proximal femoral replacements still are used on an occasional basis. Median followup in this retrospective study was 32 months (range, 24–46 months), and one patient was lost to followup before the 2-year minimum. The femoral deformities in this series were Paprosky Type I (10 hips), Paprosky Type II (26), Paprosky Type IIIA (52), Paprosky Type IIIB (nine), and Paprosky Type IV (two). Functional assessment was performed using the Oxford Hip Score (OHS), WOMAC, SF-12, and the University of California Los Angeles (UCLA) activity score. All complications and cases of revision were documented. All patients had radiographs performed within 1 year of the latest followup. These were assessed by two surgeons for signs of proximal femoral bone remodeling and subsidence.

Results

Complete preoperative scores were available for 98 patients (98 of 104; 94%). The mean OHS preoperatively and at final followup were 39 (SD, 15) and 87 (SD, 19), respectively (p < 0.001; mean difference, 48; 95% CI, 43–53). Average WOMAC scores were 44 (SD, 15) and 87 (SD, 20), respectively (p < 0.001; mean difference, 43; 95% CI, 38–48). At final followup, signs of restoration of proximal femoral bone stock was noted in 45 of 103 hips (44%). Six (six of 104; 6%) patients had subsidence of 10 mm to 15 mm. In the remainder (98 of 104; 94%), the mean subsidence was 2 mm (range, 0–9 mm). One revision was performed for loosening associated with infection.

Conclusions

The Wagner SL stem is a viable option for patients with Paprosky Types II and III defects undergoing revision THA. This component provides high levels of patient function with low revision rates and low rates of subsidence during the early postoperative phase. They provide a viable alternative to modular components for treatment of Types II and III defects without the risk of junctional fractures. They can be used for very selected Type IV defects, however this extent of bone loss is most easily addressed with other techniques such as a proximal femoral replacement.

Level of Evidence

Level IV, therapeutic study

     

Radiographic and Clinical Outcomes of Modular Tapered Fluted Stems for Femoral Revision for Paprosky III and IV Femoral Defects or Vancouver B2 and B3 Femoral Fractures

BackgroundExtensive femoral bone loss poses a challenge in revision total hip arthroplasty (rTHA). Many techniques have been developed to address this problem including fully porous cylindrical stems, impaction bone grafting, and cementation of long stems, which have had varied success. Modular tapered fluted femoral stems (MTFS) show favorable results. We sought to determine the minimum 2-year radiographic and clinical performance of MTFS in rTHA in a population with extensive proximal femoral bone loss.MethodsOur clinical database was queried retrospectively for all patients who underwent rTHA with an MTFS. We included patients with Paprosky 3 and 4 femoral bone loss and patients with Vancouver B2 and B3 periprosthetic femur fractures. Patients without 2-year follow-up were invited to return to clinic for X-ray evaluation and to complete clinical questionnaires. We assessed distance of stem subsidence and presence of stem fixation on final X-ray. We recorded all-cause revision and survival of the stem at final follow-up.ResultsOne hundred twenty-nine patients were available for follow-up. Average follow-up time was 3.75 years. One hundred twenty-two stems (95%) remained in place at final follow-up. Median subsidence was 1.4 mm (range 0-21). All-cause revision rate was 16.3% (21 patients). Of the hips revised, 10 were for instability, 6 for infection, 1 for aseptic loosening, and 1 for periprosthetic femur fracture. Three were revised for other reasons. The stem was revised in 7 patients (5.4%), and the most common reason for stem revision was infection (5 patients). The other 2 stems were revised for aseptic loosening in a Paprosky 4 femur and periprosthetic femur fracture. Survival of tapered modular fluted stems with aseptic failure as an endpoint was 98.4%. The mean Hip disability and Osteoarthritis Outcome Score, Joint Replacement score at final follow-up was 73, and mean Veterans Rand 12 item health survey physical and mental scores were 32.8 and 52.2, respectively.ConclusionIn patients with Paprosky 3, 4 femoral defects or Vancouver type B2, B3 fractures, modular tapered fluted stems for femoral revision show excellent outcomes at minimum 2-year follow-up.     

A Role for Modern Primary Cementless Femoral Stems in Revision Hip Arthroplasty

BackgroundIn revision total hip arthroplasty (THA) cases with preserved femoral metaphyseal bone, tapered proximally porous-coated “primary” femoral stems may be an option. The objective of this study was to compare outcomes of patients with Paprosky I or II femoral bone loss undergoing revision THA with either a primary metaphyseal-engaging cementless stem or a revision diaphyseal-engaging stem.MethodsThis was a retrospective analysis of 70 patients with Paprosky I or II femoral bone loss who underwent femoral revision. 35 patients who were revised using a primary cementless femoral stem were compared with 35 patients who underwent femoral revision using a revision diaphyseal-engaging stem. The groups were similar regarding age, gender, body mass index, and American Society of Anesthesiologists. Clinical and radiographic outcomes and complications were compared over an average follow-up of 2.9 years (SD 1.4).ResultsRevision THA was most commonly performed for periprosthetic joint infection (N = 27, 38.6%). The groups were similar with regards to Paprosky femoral classification (P = .56), length of stay (P = .68), discharge disposition (P = .461), operative time (P = .20), and complications (P = .164). There were no significant differences between primary and revision femoral stem subsidence (0.12 vs. 0.75 mm, P = .18), leg length discrepancy (2.3 vs. 4.05 mm, P = .37), and Hip Disability and Osteoarthritis Outcome Score Jr (73.1 [SD 21.1] vs. 62.8 [SD 21.7], P = .088). No patient underwent additional revision surgery involving the femoral component.ConclusionUse of modern primary cementless femoral stems is a viable option for revision hip arthroplasty in the setting of preserved proximal femoral metaphyseal bone. Outcomes are not inferior to those of revision stems and offer potential benefits.     

Outcomes of Cerclage Cabling for Intraoperative Calcar Cracks in Cementless Total Hip Arthroplasty Using Broach-Only,Tapered Wedge Stems

BackgroundIntraoperative femoral fractures are well-known but often overlooked complications in total hip arthroplasty (THA). We examined outcomes of cerclage cabling for intraoperative calcar cracks in THA with cementless tapered wedge stems.MethodsIn total, 4928 primary THAs were performed using broach-only, tapered wedge stems between January 2007 and November 2017 in a single institution. Of these, we identified 71 intraoperative calcar cracks (69 patients) managed by 2-mm cerclage cables. Clinical outcomes, amount of stem subsidence, and implant survivorship of the calcar crack group (68 THAs) were compared with those of the matched control group (68 THAs) without intraoperative fractures. Multivariate analysis was performed to identify potential risk factors for stem subsidence >3 mm.ResultsThe mean stem subsidence was greater in the calcar crack group (2.0 vs 1.2 mm, P = .021), whereas revision-free survivorships of THA were similar between groups at 6 years (98.5% vs 98.4%; log-rank, P = .987). In the calcar crack group, a Dorr type C femur and the absence of cabling proximal to the lesser trochanter (LT) were identified as independent risk factors for stem subsidence >3 mm. For the subgroup with 42 calcar cracks managed by a single cable applied proximal to the LT, revision-free survivorship of THA was 100% at 6 years. There was no complete radiolucency to indicate aseptic stem loosening in either group.ConclusionThe application of a single cable proximal to the LT of the femur for intraoperative calcar cracks demonstrated 100% revision-free survivorship with lower stem subsidence in THA with tapered wedge stems.     

Subsidence of Hydroxyapatite-Coated Femoral Stem in Dorr Type C Proximal Femoral Morphology

BackgroundGood bone quality and proper proximal femoral morphology are thought to be necessary for tapered design, cementless femoral stems to resist subsidence. Using tapered, cementless stem for patients with stovepipe morphology or Dorr type C is controversial. The purpose of this study is to analyze (1) subsidence of the fully hydroxyapatite (HA)-coated, tapered, cementless stem in different morphology according to Dorr classification, (2) subsidence of the stem related to radiographic canal-fill ratio.MethodsThe digitized radiographs of 311 consecutive cementless primary total hip arthroplasty with fully HA-coated, tapered stem were retrospectively reviewed. Subsidence and the canal-fill ratio at 4 locations were evaluated postoperatively after a minimum of 2 years of follow-up. The threshold of subsidence >3 mm was considered as a clinically significant migration.ResultsA multivariate regression analysis of subsidence across Dorr type, controlling for age, gender, and intraoperative calcar fracture, demonstrated 0.40 mm (P = .28) and 0.18 mm (P = .51) greater subsidence in Dorr type C and B when compared to Dorr type A. Age, gender, and calcar fracture had no influence on subsidence, whereas greater canal-fill ratio at 2 cm below lesser trochanter resulted in significantly less subsidence (P = .02). Additionally, all variables did not affect the risk of having subsidence >3 mm.ConclusionThe proximal femoral morphology has no statistically significant effect on the subsidence of fully HA-coated stem. Therefore, this stem type might be a viable option for Dorr type C. Increasing the canal-fill ratio at metadiaphyseal junction may ensure the stability of the stem.     

What Is the Difference Between Modular and Nonmodular Tapered Fluted Titanium Stems in Revision Total Hip Arthroplasty

Background

Both modular and nonmodular tapered fluted titanium stems are used in revision total hip arthroplasty (THA), with follow-up showing good results for both stems. We aimed to determine whether there were any differences in clinical outcomes, survivorship, or frequency of complications.

Stay Short or Go Long in Revision Total Hip Arthroplasty With Paprosky Type II Femoral Defects: A Comparative Study With the Use of an Uncemented Distal Fixating Modular Stem and a Primary Monobloc Conical Stem With 5-Year Follow-Up

BackgroundIn the revisions for Paprosky type II femoral defects, diaphyseal fixating femoral stems are commonly used. To preserve bone stock, the use of a shorter primary conical stem could be an adequate alternative. The objective of this study is to compare the results of a primary conical stem to the more commonly used diaphyseal fixating modular revision stem in revision total hip arthroplasty surgery with Paprosky type II femoral defects.MethodsA total of 59 consecutive patients with Paprosky type II femoral defects from our prospective revision registry were included. Thirty patients who received a long distal fixating modular stem (Revision Stem, Lima Corporate) and 29 patients who received a primary conical short stem (Wagner Cone, Zimmer) were prospectively followed. Minimal follow-up time was 2 years for subsidence and patient-reported outcome measures and 5 years for complications, reoperation, and revision. We compared subsidence, perioperative complications, reoperations, femoral component survival, Oxford Hip Score, EuroQol 5 Dimension, visual analog scale (VAS) for pain at rest, and VAS for pain during activity between stems.ResultsBoth groups were comparable regarding demographic, clinical, and surgery-related characteristics. We found more perioperative complications and stem revisions with the modular revision stem than with the primary conical stem. There were no statistical differences in subsidence, EuroQol 5 Dimension, Oxford Hip Score, and VAS for pain at rest or during activity between both stems.ConclusionIn revision total hip arthroplasty with Paprosky type II femoral defects, uncemented primary monobloc conical femoral stems showed the same clinical result as distal fixating modular stems with fewer complications and fewer stem revisions.     

Modular Fluted Tapered Stems in Aseptic Oncologic Revision Total Hip Arthroplasty: A Game Changer?

BackgroundModular fluted tapered (MFT) stems are the most frequently used femoral component in revision total hip arthroplasties (THAs). Despite this, no data are available on how they perform in revision THA for oncologic salvage. This is a unique population, often with severe bone loss and prior radiation that extends the limits of uncemented femoral reconstruction. The aims of this study were to evaluate the implant survivorship, radiographic results, and clinical outcomes of MFT stems used for revision oncologic salvage.MethodsWe identified 17 patients treated initially with primary THA for an oncologic diagnosis (15 primary oncologic, 2 metastatic disease) who underwent subsequent femoral revision with an MFT stem. Mean age at revision was 66 years and 35% of patients were female. Mean follow-up was 4 years. Before revision, 5 of 17 had undergone local radiation.ResultsTen-year survivorship free from aseptic loosening was 100%. The survivorship free of any reoperation was 76%. There were no femoral component fractures. Three patients were revised for recurrent instability, and 1 patient underwent irrigation and debridement for an acute infection. At most recent follow-up, no patient had radiographic evidence of progressive femoral component subsidence or failure of osteointegration. The mean Harris Hip Score improved from 29 preoperatively to 76 postoperatively (P < .0001).ConclusionIn this series of patients with cancer, many of whom had severe bone loss and/or prior local radiation, being treated with revision THA, there were no revisions for femoral component loosening and no cases of implant fracture.Level of EvidenceIII.     

Outcomes and Risk Factors of Extended Trochanteric Osteotomy in Aseptic Revision Total Hip Arthroplasty: A Systematic Review

BackgroundAlthough extended trochanteric osteotomy (ETO) is an effective technique for femoral stem removal and for the concomitant management of proximal femoral deformities, complications including persistent pain, trochanteric nonunion, and painful hardware can occur.MethodsThe US National Library of Medicine (PubMed/MEDLINE) and the Cochrane Database of Systematic Reviews were queried for publications utilizing the following keywords: “extended” AND “trochanteric” AND “osteotomy.”ResultsNineteen articles were included in the present study with 1478 ETOs. The mean overall union rate of the ETO was 93.1% (1377 of 1478 cases), while the overall rate of radiographic femoral stem subsidence >5 mm was 7.1% (25 of 350 cases). ETO union rates and femoral stem subsidence rates were similar between patients with periprosthetic fractures treated with total hip arthroplasty (THA) revision and ETO and patients treated with THA revision and ETO for reasons other than fractures. There was limited evidence that prior femoral cementation and older age might negatively influence ETO union rates.ConclusionThere was moderate quality evidence to show that the use of ETO in aseptic patients undergoing single-stage revision THA is safe and effective, with a 7% rate of ETO nonunion and subsidence >5 mm in 7%. ETO can be safely used in cases with periprosthetic fractures in which stem fixation is jeopardized and a reimplantation is required. A well-conducted ETO should be preferred in selective THA revision cases to prevent intraoperative femoral fractures which are associated with deteriorated clinical outcomes. The use of trochanteric plate with cables should be considered as the first choice for ETO fixation.     

Zementfreier Femurschaftwechsel mit einem modularen Hüftendoprothesenrekonstruktionsschaft

Background

In most cases, loosening of a prosthesis stem is accompanied by periprosthetic osteolysis. This article presents the short-term clinical and radiological results after revision of total hip arthroplasty (THA) with bone substance deficiencies using a modular noncemented femoral stem system (LINK MP).

Patients and methods

Between March 2003 and November 2005, 91 LINK MP modular revision stems were implanted in 90 patients. Eighty-one patients (51 stem revisions, 24 revisions of stem and shell, and six reimplantations after a Girdlestone situation) were available for prospective clinical and radiological evaluation at an average follow-up time of 16.7±6.5 (6–36) months. The average patient age at revision was 67.2±10.5 (31–87) years.

Results

Bone defects in the proximal femur were evaluated according to the Paprosky classification and showed type 2 in five cases, type 3A in 73 cases, and type 3B in three cases. The Merle d’Aubigné score increased significantly from 10.4±2.3 (4–15) preoperatively to 14.7±2.2 (9–18) at the latest follow-up (p<0.001). Migration analysis in conventional radiographs revealed an average stem subsidence of 3.4 mm. Thirty-one intraoperative and postoperative complications were noted in 28 (34.5%) patients.

Conclusion

After a short-term follow-up, the modular noncemented femoral stem system LINK MP was shown to be a reliable tool for revision of THA with bony defects of the proximal femur. Our results are comparable to those for other modular noncemented revision stems. As expected, complication rates were higher than with primary THA.     

Revision Hip Arthroplasty Using a Modular,Cementless Femoral Stem: Intermediate-Term Follow-Up

Background

Modular femoral stem provides flexibility in femoral reconstruction, ensuring improved “fit and fill”. However, there are risks of junction failure and corrosion, as well as cost concerns in the use of modular femoral stems.

Cemented Polished Tapered Stems Have Lower Revision Rates Than Commonly Used Cementless Implant up to 17 Years of Follow-Up: An Analysis of 201,889 Total Hip Replacements From the Australian Orthopedic Association National Joint Replacement Registry

BackgroundData assessing femoral stems may be influenced by grouping together matt and polished stems, despite their differing reported survivorship. The aim of this study is to assess the difference in revision rates between commonly used cemented and cementless stems when polished tapered stems are assessed independently of matt stems.MethodsAustralian Orthopaedic Association National Joint Replacement Registry data from 1999 to 2019 were used to assess difference in revision rates between the 5 most commonly implanted femoral cemented and cementless stems for osteoarthritis. Cemented matt femoral stems, stems using line-to-line cementing techniques and procedures using non-cross-linked polyethylene, large head (>32 mm) metal-on-metal bearing surfaces or exchangeable necks were excluded. Cumulative percent revision was used to help compare survivorship between stems.ResultsThere were 201,889 total hip replacements meeting the inclusion criteria, of which 50.0% were cemented and 50.0% cementless. Cemented stems had a lower rate of revision at all time points compared to cementless stems. This was most significant during the first 2 weeks (hazard ratio 0.48, 95% confidence interval 0.40-0.58, P < .001) compared to 2 weeks postoperatively and onwards (hazard ratio 0.85, 95% confidence interval 0.81-0.90, P < .001). A subanalysis of head size, bearing type, and surgeon volume further supported the use of a cemented stem.ConclusionCommonly used cemented polished tapered stems have a lower revision rate when compared to commonly used cementless prostheses, and are recommended in all age groups for both low-volume and high-volume surgeons especially when head size 32 mm or smaller is used.     

Mid-term outcomes following transfemoral revision of total hip arthroplasty for Vancouver B2/B3 periprosthetic fractures

IntroductionPeriprosthetic femoral fractures (PFF) are often the reason for revising total hip arthroplasty (RTHA). Converting these fractures into modified extended trochanteric osteotomy (mETO) facilitates stem revision. Modular revision stems are a common choice with good results. We present mid-term outcomes in patients undergoing RTHA for Vancouver B2/B3 PFF using a tapered, fluted modular stem with an mETO approach.Materials and methodsA single-center analysis of patients with RTHA for Vancouver B2/B3 PFF using a single modular implant with mETO was performed (2007 – 2019). Clinical outcome (mobility, range of motion, function), radiological outcome (fracture healing, stem subsidence) and patient reported outcome measures (FJS-12, HHS, EQ-5D) were assessed.ResultsNinety-seven patients (mean age 78.1 years, BMI 25.8 kg/m², 85.6% B2-fractures) were included; 80 patients had complete clinical and radiological follow-ups. Normal unaided gait without limping was achieved in 38/80 patients. After one year fracture / mETO healing occurred in 74/80 patients; 5.3 years after surgery, the respective FJS-12, HHS and EQ-5D (available in 34 patients) averaged 81.3 ± 30.2, 71.4 ± 18.7 and 0.8 ± 0.2. We documented 7 in-hospital deaths, 18.8% postoperative complications and 13.8% revisions with stem revisions being most commonly for subsequent PFF or subsidence.ConclusionGood clinical and radiological outcomes and rather low complication and revision rates (18.8% and 13.8%) were achieved. FJS-12 showed excellent results in patients undergoing RTHA for Vancouver B2/B3 PFF using a cementless, dual modular titanium revision stem and an mETO approach. Joint awareness was thereby similar to previously reported primary THA results at 5.3 years follow-up.     

Conical Primary Cementless Stem in Revision Hip Arthroplasty: 94 Consecutive Implantations at a Mean Follow-Up of 12.7 years

BackgroundRevision 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).MethodsNinety-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 = 59) underwent isolated stem revision; Group 2 (n = 15) underwent complete THA revision. All were evaluated preoperatively 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, subsidence, loosening, and heterotopic ossification.ResultsPCS 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%).ConclusionThe 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.     

Revision Total Hip Arthroplasty With a Modular Cementless Femoral Stem

We retrospectively reviewed 123 patients who underwent cementless THA with modular femoral stem designs for revision THA or conversion of failed ORIF and found 75 patients available for analysis. The Harris Hip Score (HHS) improved from 52 ± 14 to 86 ± 11 (P < 0.001). The femoral stem was re-revised in eight patients (11%). The mean time to re-revision was 1.1 years (0.13–2.54). Reasons for re-revision included infection (n = 5, 7%), aseptic loosening (n = 2, 3%) and significant pain (n = 1, 1%). There were no failures of the modular junctions. PC stems had an increased rate of intraoperative fractures (PC 28% vs. STS 9%, P = 0.04). Modular cementless femoral stems provide acceptable mid-term results in revision THA.     

A Large-Scale Fifteen-Year Minimum Survivorship of a Cementless Triple Tapered Femoral Stem

BackgroundThis study reports the long-term outcomes of a metaphyseal fit-and-fill cementless femoral component in total hip arthroplasty (THA) with a follow-up of 15-19 years.MethodsWe conducted a retrospective review of 376 consecutive THAs (345 patients), using a triple tapered stem performed between 2000 and 2003 with a view to assessing survivorship and radiological and functional outcomes. Images were assessed for initial alignment, terminal osteolysis, or subsidence, while clinical outcomes were assessed using the St Michael’s Hip Score.ResultsForty-five (11.9%) hips were lost to follow-up, 20 (5.31%) had died before our 15-year cutoff follow-up, and 4 (1.06%) had declined follow-up early on, leaving 307 hips (81.64%, 276 patients) available for both clinical and radiological follow-up at a minimum of 15 years (range 15-19). The mean age at the time of operation was 49.6 years (range 19-71) and the cohort included 131 (42.67%) male and 145 (47.23%) female patients. Seven stems (2.28%) were revised: 4 due to periprosthetic fractures, 2 for periprosthetic joint infection, and 1 for adverse reaction to metal debris at the trunnion. The St Michael’s Hip Score improved from 14.2 (range 9-23) preoperatively to 22.3 (range 13 to 25) at the last documented follow-up (P = .000). Kaplan-Meier survivorship with stem revision for any reason as the end point was 97.70%. Worst-case scenario Kaplan-Meier survivorship, where all lost to follow-up are considered as failures, was 85.3%. No stem was revised for aseptic loosening.ConclusionThis triple tapered stem in THA shows excellent survivorship beyond a minimum of 15 years.