Femoral Revision Research Articles

Durability of Primary Total Hip Arthroplasty With Cementless Stems Without a Collar in Elderly Patients Age 75 Years and Over

BackgroundCementless femoral fixation in total hip arthroplasty (THA) has increased in prevalence worldwide. However, cementless fixation in elderly patients is controversial due to the risks of periprosthetic fracture and aseptic loosening. This study evaluated outcomes in patients undergoing primary THA utilizing a cementless stem without a collar, comparing those less than 75 years to those older than 75 years. MethodsBetween 2011 and 2021, there were 2,605 cementless THAs performed by 4 surgeons utilizing a highly porous metal fixation surface without a collar and consistent clinical protocols. There were 469 patients who had an age ≥ 75 years. Revision rates, intraoperative fractures, and 90-day mortality were compared between cohorts. In the ≥ 75 year age group, there were more women, more American Society of Anesthesiologists physical status classification III or IV, a lower body mass index, and more kidney disease, osteoporosis, and thyroid disease (P ≤ .002). ResultsAll-cause revision rates trended lower for the ≥75 year age group compared to < 75 year (1.9 versus 3.5%, P = .082) at 20-months of follow-up. Moreover, there was no difference in all-cause femoral component revisions comparing ≥ 75 to < 75 year age groups (1.5 versus 2.2%, P = .375), with only 3 of 10 femoral revisions due to aseptic loosening being in the ≥ 75 year age group. Intraoperative fracture (0.2 versus 0.5%, P = .701) and 90-day mortality (0.2 versus 0.1%, P = .460) did not differ between ≥ 75 and < 75 year age groups. ConclusionsOlder patients had comparable revision rates compared to younger patients using cementless femoral fixation without a collar. Furthermore, there was no difference in 90-day mortality or intraoperative fracture rates. Study findings provide evidence for the safety and durability of cementless THA using collarless femoral stems in elderly patients ≥ 75 years of age. Level of EvidenceIII.

The Minimum 5-Year Follow up of a Highly Versatile Distally Anchored Femoral Revision System With Hydroxyapatite Coating

BackgroundTotal hip arthroplasty is one of the most successful operations medicine can offer. As more patients undergo total hip arthroplasty the revision burden increases proportionately. This is a cohort study of the Arcos Modular Femoral Revision System. MethodsThe primary outcome was rerevision of the femoral component. Secondary outcomes include complications and radiological and clinical outcomes over 5 years. ResultsA total of 74 patients were recruited, and the femoral survival rate was 100% at 5 years with 12 censorships. A total of 31 patients were given Proprosky 3/4 preoperatively. Eleven patients underwent further procedures; however, no femoral components were revised. Kaplan-Meier analysis was performed by a biostatistician. Patients demonstrated a consistent and sustained improvement in Harris hip score, Oxford hip score, and EQ-5D. Radiological review revealed minimal and stable lysis around the femoral components. ConculsionThe ARCOS Modular Femoral Revision System was designed to offer a range of options to allow femoral bone stock preservation and avoiding conversion to an endoprosthetic and seems to be effective in the medium term.

Time to Revision Total Hip Arthroplasty Impacts Short-Term Outcomes Following Surgery

AbstractPrevious reports have investigated the correlation between time to revision total hip arthroplasty (rTHA) and reason for revision, but little is known regarding the impact of timing on outcomes following rTHA. The purpose of this study is to evaluate the effect of time to rTHA on outcomes following rTHA. This retrospective observational study reviewed patients who underwent unilateral, aseptic rTHA at an academic orthopaedic hospital between June 2011 and April 2020 with at least 1-year of follow-up. Patients were categorized as early revisions if revised within 2 years of primary total hip arthroplasty (pTHA) or late revisions if revised after more than 2 years from pTHA. Patient demographics, surgical factors, and postoperative outcomes were compared. Multiple linear regression and binary logistic regression were used to determine significance of outcomes while controlling for confounding variables. Of the 467 cases, 150 underwent early revision and 317 underwent late revision. Early revisions experienced longer hospital length of stays (LOSs, days; 4.93 ± 3.93 vs. 3.28 ± 2.09; p &lt; 0.001), all-cause 90-day readmission rates (11.3 vs. 12.7%; p = 0.032). Across all revision types, multivariate analysis revealed that time to rTHA (p &lt; 0.001) and revision type (0.008) were found to be significant predictors of LOS while controlling for patient factors. Subanalyses within each revision type (femoral, acetabular, head/liner, and full) further reveal that time to rTHA is a significant independent predictor of LOS. Early revisions had a greater proportion of femoral revisions (44.0 vs. 15.5%), and late revisions had a greater proportion of head/liner (43.2 vs. 18.7%; p &lt; 0.001) revisions. There were no significant differences between the two cohorts with respect to discharge disposition, surgical time, all-cause 90-day emergency department (ED) visits, re-revisions, and number of re-revisions. Patients undergoing aseptic rTHA within 2 years of index pTHA had longer LOS and greater rates of readmission. Time to rTHA is a significant independent predictor of LOS across and within all revision types and reason for revision aside from liner exchange and trunnionosis. No differences were seen in operative time, discharge disposition, re-revision, mortality, reoperation, and ED admission between early and late rTHAs across all revision subtypes. Level of evidence is III, retrospective observational analysis.

Mid-term results of a cementless hip stem in femoral revision: how much diaphyseal press-fit do we need?

The aim of this retrospective study was to analyze the clinical and functional outcome of a modular tapered revision hip stem after mid-term follow-up with a special focus on the length of the distal bicortical fixation of the cementless hip stem. Follow-up examination was carried out for all patients with implantation of the Prevision hip stem between 2014 and 2019 to collect demographic, functional, and radiographic data. 44 patients with stem in situ were examined, and 61 patients could be included in the Kaplan-Meier survival analysis. Oxford's hip score was 37.3 at the mean follow-up of 4.0years. Two hip stem revisions were performed due to periprosthetic infection, which resulted in a hip stem survival rate of 96.7% (CI: 87.4-99.1%) at the final follow-up of 7.5years. No aseptic hip stem revision was required. The length of bicortical distal fixation was in the interquartile range of 6.8 to 9.0cm, which was associated with good bone healing and a low rate of subsidence (4.5%). Implant-associated complications were observed in 10 cases (21.7%). The modular revision hip stem provides promising results at medium-term follow-up, with satisfactory clinical and functional outcomes comparable to other modular revision hip stems. The presented length of bicortical distal fixation shows the practice of the study center and was associated with good implant survival, bone healing and radiological results. Clinicaltrials.gov registration: NCT04833634 registered on April 6, 2021.

Last generation fluted modular titanium stem in revision hip arthroplasty: a narrative review of mid- and long-term outcomes.

Tapered fluted titanium stems (TFTS), were introduced to overcome proximal femur bone defects. They obtain stable fixation even in catastrophic proximal bone loss. Modular ones have the advantage to adjust length, rotation, off-set independently from the distal module. Short-term publications have been showing favorable outcomes burdened by an unacceptably high rate of stem failure. Still, there is a paucity of mid- and long-term reports. This narrative review aims at analyzing recent literature on modular TFTS with at least 5 years of minimum follow-up to gain a better understanding of implant survival, performance, and complications. A search of the PubMed database was performed with selected key terms. Results were screened after the application of strict inclusion and exclusion criteria. Extracted data were subsequently evaluated to obtain an up-to-date overview of the results and complications of TFTS. Modular TFTS showed a consistent increase in patient reported outcomes that persists at 10 years and above. Femoral fractures were the most common intraoperative complication. Despite modularity, dislocation still occurs at a variable rate (1.2-12%). With revision for any cause as an endpoint, overall survival approaches 83% after 10 years of follow-up. If femoral revision only is evaluated, excellent survival rates (>95%) have been published. Stem subsidence over 5 mm was reported in less than 5% of patients, only 1 requiring femoral revision. The mean incidence of stem mechanical failure was 3.39%, although most breakages occurred in stems eventually retired from the market. Satisfactory survival rates were observed, with an acceptable rate of complications. Stem mechanical failure, excluding those stems eventually retired from the market, remains a marginal event. Therefore, the use of modular TFTS in revision surgery is safe and effective even in the long term.

Implant Survival of an Uncemented Modular Femoral Implant in Patients With Severe Femoral Bone Loss and 2‐Stage Hip Revision

Background and Purpose: Revision total hip arthroplasty (rTHA) is a challenging procedure especially in the presence of severe bone loss where implant fixation is compromised. The aim of this study was to evaluate implant survival, clinical outcome, and midterm results in a group of complex patients after femoral revision using an uncemented modular implant design.Patients and Methods: We performed a retrospective study including 100 patients (101 hips) treated with revision THA using an uncemented modular implant design. We identified 51 hips as Paprosky types I‐II and 50 hips as Paprosky III‐IV bone defects. We reviewed operative reports and radiographs. Patients underwent a clinical examination to assess the Harris Hip Score (HHS) and completed patient‐reported outcome measures (PROM), including the Oxford Hip Score (OHS) and the EQ‐5D Visual Analog Scale (VAS). Minimum follow‐up was 2 years (average, 5.8 years; range, 2.0–9.4 years).Results: Among the cases, 46 hips were revised for infection in a 2‐stage procedure and 44 hips for aseptic loosening. 11 hips had periprosthetic fractures of Vancouver type B2 or B3. A total of 5 hips required revision with removal of the femoral implant and 11 patients experienced complications resulting in fracture (n = 1), dislocation (n = 10), and soft tissue revision (n = 1). The 5‐year implant survival estimated by Kaplan–Meier survival analysis was 95% (95%‐CI: 91%–99%). All hips had radiographic evidence of osseointegration and no one with subsidence greater than 5 mm. Additionally, 80% showed radiographic evidence of restoration of proximal femoral bone. Mean HHS was 78.Conclusion: In complex cases of revision THA, using a modular revision femoral system yielded promising results. The 5‐year implant survival estimated by Kaplan–Meier survival analysis was 95% (95%‐CI: 91%–99%), with all hips demonstrating radiographic evidence of osseointegration and no one with subsidence greater than 5 mm. Notably 80% showed radiographic evidence of restoration of proximal femoral bone.

Treatment of femoral bone loss in revision total hip arthroplasty: a clinical practice review.

Patient and implant selection is essential to optimize outcome. Femoral bone loss classifications such as the American Academy of Orthopaedic Surgeons, Gross, and Paprosky classifications permit surgeons to systematically manage bone stock deficiencies and guide implant selection. Here we provide a comprehensive report on the pitfalls and management of this reconstructive challenge. Preoperative planning remains vital to the treatment of femoral bone loss in revision hip arthroplasty and the authors believe it is essential and should include the entire femur. This commonly includes imaging for bone loss such as Judet views or computed tomography scan and must include the entire femur though additional radiographs such as Judet views apply more for acetabular bone loss as opposed to femoral bone loss. All patients should have pre-operative work up to exclude infection. If any of these results area elevated, an aspirate and sampling is required to guide microbiological management. Classically with regards femoral revision surgery, uncemented fixation has proven to give the best outcomes but surgeons must remain flexible and use cemented fixation when necessary. Adequate proximal bone stock permits the use of implants used in primary joint surgery. Implants with proximal modularity can be used in cases where bone stock allows for superb proximal bone support. The vast majority of femoral revisions have inadequate proximal bone stock, thus distally fixed stems should be used and have been shown to provide both axial and rotational stability provided there is an intact isthmus. Taper fluted stems can provide good outcomes even in cases of major bone loss. However, with severe bony loss, impaction grating or the use of a megaprotsthesis is sometimes necessary and is down to surgeon choice and preference. This article has been written as a guide for management and summarises the best evidence available.

Clinical and radiological outcomes and analysis of failures of modular revisions stems at long-term follow-up: a systematic review and meta-analysis.

Increasingly hip replacements at young age exposes the patient to an increased risk of failure of the implant over the years. In case of failure, revision specific stems were designed to overcome bone loss. Modularity of these devices is an important resource for the surgeon as they allow the new implant to be better adapted to the patient's anatomy. The purpose of this systematic review is to provide data about the outcome at long-term follow-up (>8 years) of hip modular revision femoral stems. This systematic review and meta-analysis were conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement guidelines. PubMed and Google Scholar databases were systematically and independently searched, according to the inclusion and exclusion criteria. Two reviewers performed the data extraction independently. In case of disagreement, the senior authors were sought to resolve the divergences. Quality of the involved studies was evaluated with National Institute for Health and Care Excellence (NICE) guidelines (eight-item list) and the Newcastle-Ottawa scale (NOS). Primary and secondary outcomes were evaluated. The statistical analysis of this meta-analysis was performed by using Excel Microsoft and the software STATA. The primary outcome was the re-revision rate of modular revision stems at long-term follow-up. It ranged from 1.4% to 45.6%: random effect pooled estimate was 5.5% [95% confidence interval (CI): 4% to 7%], with a I2 of 12.3% (P=0.332). Mean Harris Hip Score (HHS) was 83 [min: 79; max: 87.6; standard deviation (SD): 3.55]. Secondary evaluated outcomes were: subsidence >5 mm, rate of periprosthetic infection or fractures (intra- and post-operative) and dislocations. The mean value for the NICE tool was 5.5 (SD: 1.13) and 7.3 (SD: 0.79) for the NOS tool. The survival rate was >90% at long-term follow-up (min: 60%; max: 97%). The modular femoral revision stems have demonstrated good long-term reliability and efficacy. This meta-analysis demonstrates that the re-revision rate after 8 years of follow-up is low and 90% of the implants did not fail.

Cantilever Failure of Modular Uncemented Femoral Revision Stem in Patients with Poor Proximal Femoral Support; How to avoid it?

Revision hip arthroplasty is a major surgical challenge and is even more difficult in cases with a deficient proximal femur. Modular uncemented cone body revision femoral stems were introduced as a solution. They have the advantage of optimising joint kinematics by allowing the variable degrees of version, offset and leg length. However, we noticed cantilever failure of such stems, particularly in patients with deficient proximal femoral support. Fatigue fracture of the revision femoral stems should raise questions about its use in patients with insufficient proximal femoral bone support. We present a case series of five patients with the cantilever failure of Stryker restoration modular stem conical distal femur prosthesis. These cases were identified during a retrospective review of revision hip surgeries performed at our trust. The stem failed after an average of 22.6 months post-revision surgery. Primarily, poor proximal femur bone support with a well-fixed distal stem and secondarily high BMI led to this catastrophic failure in the absence of trauma. All five cases were re-revised to Stanmore proximal femoral replacement and achieved good functional outcomes after an average follow-up of seven years. Proximal femoral bone support should be restored to prevent early cantilever failure of distally fixed proximal modular revision femoral stems. Consider a proximal femoral replacement if we cannot ensure proximal bone support.

Shape-memory sawtooth-arm embracing clamp used in complex femoral revision hip arthroplasty for stem stability: average 9-year follow-up study

BackgroundNickel-Titanium shape-memory sawtooth-arm embracing clamps (SSECs) have been used in revision total hip arthroplasties (rTHAs) to protect stem stability. This study was to introduce this technique and report its mid to long-term clinical and radiographic outcomes.MethodsWe retrospectively reviewed all patients implanted with SSECs in our department from January 2008 to December 2015. 41 patients (41 hips) were finally included. Radiographs and Harris hip scores (HHS) were collected. Radiographs were blindly analyzed for evidence of loosening, subsidence and stress shielding. HHS were compared to previous records by student’s t tests. The average follow-up period was 9.3 years.ResultsAll stems were stably fixed with no signs of loosening. The mean stem subsidence was 0.9 mm (range, 0 to 3 mm). Only one patient (2.4%) demonstrated the fourth degree of stress shielding, with the others none or minor bone resorption. The mean HHS at the final follow-up was 84.2 (range, 81 to 91), which was improved from 17.4 (range, 0 to 37) before surgery. No implant failures or re-revisions occurred. Dislocation occurred in 1 case during the follow-up period.ConclusionsThe SSEC protected stem fixation and achieved favorable clinical and radiographic outcomes in this 9-year follow-up study. It offered an additional extramedullary fixation option for surgeons to choose from in treating complex femoral revision arthroplasties.

Revision of total hip arthroplasty by long locking stem with fully hydroxyapatite-coated modular metaphysis (Reef™): A continuous series of 78 cases at a minimum 2-year follow-up

IntroductionSince the Wagner and Vives stems were introduced in the 1980s, the range of uncemented implants for femoral revision has grown with increasing demand. Cementless modular implants with a wide range of lengths and diameters improved adaptation to the bone and secondary metaphyseal integration. Data are sparse for the Reef™ locking stem (Depuy-Synthes, Saint-Priest, France) and we therefore conducted a retrospective study at more than 2 years’ follow-up, in a continuous series of total hip arthroplasty (THR) revision procedures using this long fully-hydroxyapatite-coated modular locking stem, assessing (1) implant survival, (2) clinical and functional results, and (3) radiographic results. HypothesisThe study hypothesis was that all-cause≥2-year survival is>90%. Patients and methodsBetween 2007 and 2018, 413 femoral stem exchanges were performed in our center, a Reef™ model being needed in 93 cases. Etiologies comprised: Vancouver B2 or B3 periprosthetic fracture (57%, n=53), aseptic loosening (33%, n=30), septic loosening (10%, n=9) and 1 case of aseptic non-union under the stem (1%, n=1). Clinical and functional assessment used Harris Hip Score (HHS), Postel Merle d’Aubigné score (PMA) and Oxford-12 Hip Score (OHS). Radiographic assessment used immediate postoperative views and last follow-up radiographs, assessing osseointegration, filling index and stress shielding. Implant survival was estimated following Kaplan-Meier with 95% confidence intervals. ResultsMean follow-up was 6±3 years (range, 2–12). Last follow-up included 78 cases for analysis (12 deaths [13%] and 3 patients lost to follow-up before 2 years [3%]). Ten-year Reef™ implant survival was 98.7% (95% CI: 96.3–100) free of aseptic loosening (n=1) and 94% (95% CI: 87–100) for all causes (n=3). The failures related to aseptic loosening involved femoral stem fracture away from the modular part; the 2 cases of septic loosening did not undergo reimplantation for medical reasons. Preoperatively (scheduled surgeries, excluding periprosthetic fractures: n=40), mean HHS was 43±12 and 77±12 at last follow-up (81±13 in scheduled surgery [n=40] and 73±11 in emergency surgery for periprosthetic fracture [n=53]), mean PMA score was 13±2 and mean OHS was 26±9. The infection rate was 11% (n=9) including 7.6% new infection (n=6). The dislocation rate was 6% (n=5). The radiographic stress shielding rate was 11% (n=9) and significantly associated with low metaphyseal filling index (76±7% vs. 83±8% [p=0.009]). DiscussionLike other recent data, the present good survival results support the trend for uncemented stems in femoral revision, as encouraged by the 1999 symposium of the French Society of Orthopedic Surgery and Traumatology (SoFCOT). Primary diaphyseal fixation enables secondary metaphyseal integration on an implant with modularity ensuring good bone adaptation. Close contact between the bone and hydroxyapatite surfaces is a key-point in the surgical strategy. Level of evidenceIV, retrospective study.

Femoral revision in total hip arthroplasty using a cementless modular stem: clinical and radiological results with a 8-year follow-up.

Modular femoral components allow for patient-specific restoration of hip joint geometry and the reconstruction of extensive bone defects in revision total hip arthroplasty (THA); however, potential problems of modular implants such as taper corrosion and the risk of implant fracture continue to be of concern. The aim of the present study was to evaluate the clinical and radiological results of a cementless modular revision stem following revision surgery due to aseptic loosening and periprosthetic fracture and to assess patient-reported outcome measures (PROMs) in these patients at mid-term follow-up. In this study, a consecutive cohort of 75 patients who underwent primary revision THA at our institution using a modular cementless stem design (MRP-TITAN stem) was retrospectively evaluated at a mean follow-up of 7.7 years. Kaplan-Meier survivorship analyses were performed with revision of the femoral component for any reason as the end point. The Harris-Hip Score, the UCLA Activity Score, the Forgotten Joint Score and the SF-12 Score were used for clinical assessment. We used the Wilcoxon signed rank test to compare pre- and postoperative clinical scores. Overall stem survival with the endpoint stem re-revision for any reason was 85.4% at a mean follow-up of 7.7 years (range 2.4-14 years). Stem survival was 89.5% in the aseptic loosening group and 78.3% in the periprosthetic fracture group with no statistically significant difference between both groups (p = 0.107). One patient had to be revised due to taper fracture. PROMs improved significantly up to the latest follow-up, and radiographic evaluation showed full osseointegration of all stems in this cohort. Revision THA using a modular cementless titanium revision stem demonstrated adequate clinical and radiological results at mid- to long-term follow-up in this cohort. Cementless revision stems are a useful treatment option to restore the anatomy, especially in deformed hips and in complex revision hip arthroplasty. However, there are some significant disadvantages related to an increased risk of mechanical failure such as corrosion/fretting damage and implant fracture. Future high-quality prospective studies with longer follow-up are necessary to confirm the supposed advantages.

Long-term Outcomes of Revision Total Hip Arthroplasty Using a Modular Fluted Conical Femoral Stem

BackgroundThis study presents minimum 6-year follow-up data on the survival and satisfaction of an uncemented modular revision femoral system, following on from our previously published earlier results. MethodsWe retrospectively reviewed all revision hip arthroplasties performed at our institution between January 2005 and October 2012, using a single modular femoral revision system. Patient-reported outcomes were collected (satisfaction score and Oxford Hip Score). Preoperative and postoperative radiographs were reviewed for stem subsidence, and Kaplan–Meier analysis was performed for survival. A total of 115 femoral revisions were performed in 106 patients. ResultsAll-cause survival was 82% (95% confidence interval 74 to 91%) at 10.8 years, and 96% (95% confidence interval 90 to 100%) excluding septic failure. Of the 19 cases requiring reoperation, 16 were for infection, 2 for aseptic loosening, and 1 for mechanical failure. At final follow-up, 88.5% of patients were “satisfied” or “very satisfied”. ConclusionsThis study showed excellent clinical results of a commonly used revision hip stem with at least 10 years follow-up. Satisfaction rates were high, with few aseptic failures. Stem subsidence was more common in revisions for infection, but did not correlate with lower satisfaction scores.

Mean 23-Year Outcomes of Total Hip Arthroplasty Using a Modular Femoral Stem With Metaphyseal Fixation Sleeve

BackgroundAlthough the modular sleeve concept for femoral implants has several advantages, studies reporting on greater than 20-year outcomes are limited. This study aimed to report the mean 23-year results of total hip arthroplasty (THA) using a modular stem with metaphyseal fixation sleeve. MethodsThis study reviewed primary THAs performed using a modular stem between October 1994 and April 1998. Of the 272 hips (221 patients) identified, 220 hips (177 patients) satisfying the minimum 20-year follow-up were included. The Harris Hip Score was used for clinical evaluation. Final hip radiographs were analyzed to evaluate the implant stability and the extent of femoral osteolysis. The mean follow-up duration was 23 years (range, 20 to 28). ResultsThe mean Harris Hip Score improved from 38 points (range, 26 to 67) preoperatively to 90 points (range, 71 to 100) at the final follow-up (P < .001). Femoral osteolysis was observed in 146 hips (67.1%), but 145 were located proximal to the osseo-integrated sleeve. Overall, 4 femoral revisions were performed; 2 for chronic infection, one for aseptic loosening, and one for periprosthetic femoral fracture. Of the 19 (8.6%) periprosthetic femoral fractures, the most common type was Vancouver AG (13 hips). One (0.5%) asymptomatic distal stem fracture occurred, while no complications were identified at the stem-sleeve junction. Implant survivorship free of any femoral revision was 98.3% at 23 years. ConclusionsA THA using a modular stem with metaphyseal fixation sleeve demonstrated 98.3% stem survivorship with excellent clinical outcomes at a mean follow-up of 23 years in non-obese patients.

Hip &amp; Pelvis

The August 2023 Hip &amp; Pelvis Roundup360 looks at: Using machine learning to predict venous thromboembolism and major bleeding events following total joint arthroplasty; Antibiotic length in revision total hip arthroplasty; Preoperative colonization and worse outcomes; Short stem cemented total hip arthroplasty; What are the outcomes of one- versus two-stage revisions in the UK?; To cement or not to cement? The best approach in hemiarthroplasty; Similar re-revisions in cemented and cementless femoral revisions for periprosthetic femoral fractures in total hip arthroplasty; Are hip precautions still needed?

Single center evaluation of outcomes of modular dual mobility liners during revision total hip arthroplasty: A five-year follow-up

IntroductionRevision total hip arthroplasty (rTHA) is at increased risk for postoperative instability when compared to primary cases, which has been mitigated to some extent with the introduction of dual mobility (DM) reconstructions. These constructs were designed to lower dislocation rates and to improve impingement-free range of motion. As a follow-up to our prior institutional study, we expanded on a cohort of DM reconstructions compared to non-DM constructs. We examined a modular dual mobility system in rTHA to measure loosening of the acetabular component, as well as revision and dislocation rates in comparison to an historical cohort of single articulation prostheses.Materials/Methods: This retrospective cohort study from a single center included 254 patients who underwent rTHA with a dual mobility liner by three fellowship-trained surgeons between January 1, 2014 and December 1, 2019. This was a follow-up to an historical cohort of revisions performed with a single articulation prosthesis (n = 120) from the same surgeons performed between January 1, 2011 and December 23, 2013. The inclusion criteria included consecutively performed rTHAs that had a minimum follow-up of 2 years. We excluded patients who had femoral revisions and head/liner revisions only. The average follow-up in the dual mobility cohort and the single articulation cohort was 5 years (range, 2–10 years) and 2.5 years (range, 1.5–4.3 years), respectively. The primary outcomes were dislocation, aseptic loosening, and re-revision rates. Secondary outcomes were radiographic analyses of cup migration and osteolysis. ResultsThere were 4 out of 256 (1.6%) dislocations from the dual mobility cohort compared to 7 out of 120 (5.8%), P < 0.001 from the single articulation cohort. The rates of aseptic loosening were 3.2% (8 out of 254) and 4.2% (5 out of 120), P = 0.124, respectively, between the cohorts. The re-revision rate was 5.9% for the DM liners and 8.3% in the control cohort, P = 0.38. Radiographic analyses revealed no cup migration and osteolysis in any of the patients that had no dislocations. ConclusionThe dual mobility articulations in rTHA demonstrated improved results in terms of lower dislocations rates when compared to a single articulation prostheses. Our center uses these articulations for revisions and surgeons should consider the use of these bearings when performing rTHA.

THE ZWEYMULLER PRIMARY STEM IS A RELIABLE, EFFECTIVE, AND LESS INVASIVE IMPLANT IN REVISION ARTHROPLASTY

Stem loosening can be associated with a wide spectrum of bone loss and deformity that represent key factors for choosing the most appropriate revision implant. The aim of this study was to evaluate the clinical outcomes and the survivorship of a consecutive series of THA revisions using a taper rectangular cementless stem for primary implants (Alloclassic® Zweymuller®, Zimmer Warsaw US) at medium-term follow-up.We retrospectively evaluated 113 patients (115 revisions) who underwent femoral revision with Zweymuller stem with a preoperative Paprosky I (86) or II (29) defects from January 2011 to December 2020. The mean follow up was 6 years (2–10). The median age at time of surgery was 71(41–93) with 60 males and 53 females. Osteolysis/radiolucency were observed in the following Gruen zones: I (91), II (3), III (2), VII (15), V (3), VI (1). Clinical assessment was performed by means of Harris Hip Score (HHS) and Visual Analogic Scale (VAS), whereas for the radiological analysis we used conventional x-rays of the hips. The statistical analysis was performed using Graphpad Prism v5.0 and data distribution was assessed by Shapiro-Wilk test, and Wilcoxon matched paired test was used to test the differences between preoperative and postoperative score.9 patients were lost to fu (deceased or not available), 104 (106 hips) were evaluated. The mean HHS and VAS significantly improved at final follow-up, going from 33,84 and 5,78 preoperatively to 66,42 and 2,05 postoperatively, respectively. 28 patients (25%) showed unprogressive radiolucent lines in Gruen zones 1 and 7 with no other radiological nor clinical signs of loosening. One patient suffered from recurrence of the infection. The survivorship with stem revision as endpoint was 100%.Alloclassic Zweymüller primary stem showed good medium-term results and survival rate in revision THA for aseptic loosening and second stages of two stage revisions.

LONG-TERM FOLLOW UP OF THE CUP-CAGE RECONSTRUCTION FOR PELVIC DISCONTINUITY

Pelvic discontinuity is a separation through the acetabulum with the ilium displacing superiorly and the ischium/pubis displacing inferiorly. This is a biomechanically challenging environment with a high rate of failure for standard acetabular components. The cup-cage reconstruction involves the use of a highly porous metal cup to achieve biological bone ingrowth on both sides of the pelvic discontinuity and an ilioischial cage to provide secure fixation across the discontinuity and bring the articulating hip center to the correct level. The purpose of this study was to report long term follow up of the use of the cup-cage to treat pelvic discontinuity.All hip revision procedures between January 2003 and January 2022 where a cup-cage was used for a hip with a pelvic discontinuity were included in this retrospective review. All patients received a Trabecular Metal Revision Shell with either a ZCA cage or TMARS cage (Zimmer-Biomet Inc.). Pelvic discontinuity was diagnosed on pre-operative radiographs and/or intraoperatively. Kaplan-Meier survival analysis was performed with failure defined as revision of the cup-cage reconstruction.Fifty-seven cup-cages in 56 patients were included with an average follow-up of 6.25 years (0.10 to 19.98 years). The average age of patients was 72.09 years (43 to 92 years) and 70.2% of patients were female. The five year Kaplan-Meier survival was 92.0% (95% CI 84.55 to 99.45) and the ten year survival was 80.5% (95% CI 58.35 to 102.65). There were 5 major complications that required revision of the cup-cage reconstruction (3 infections and 2 mechanical failures). There were 9 complications that required re-operation without revision of the cup-cage reconstruction (5 dislocations, 3 washouts for infection and one femoral revision for aseptic loosening).In our hands the cup-cage reconstruction has provided a reliable tool to address pelvic discontinuity with an acceptable complication rate.

Hip Resurfacing in Teenagers

BackgroundThe goals of hip resurfacing are to relieve pain, restore function, and preserve future reconstructive options. Hip resurfacing is an attractive and sometimes the only option when the femoral canal is blocked, making total hip arthroplasty (THA) difficult. Hip resurfacing also can be an attractive option for a teenager on the rare occasion when a hip implant is needed. MethodsA cementless ceramic-coated femoral resurfacing implant matched with a highly cross-linked polyethylene acetabular bearing was used in 105 patients (117 hips) aged 12 to 19 years. The mean follow-up was 14 years (range, 5 to 25). No patients were lost to follow-up before 19 years. Osteonecrosis, residuals of trauma, developmental dysplasia, and childhood hip diseases were the common reasons requiring surgery. Patients were evaluated using patient-reported outcomes, patient acceptable symptom states (PASS), and implant survivorships. Radiographs and retrievals were also examined. ResultsThere were 2 revisions (polyethylene liner exchange at 12 years and femoral revision for osteonecrosis at 14 years). The mean postoperative Hip Disability Osteoarthritis Outcome Score (HOOS) was 94 points (range, 80 to 100) and the mean Harris Hip Score (HHS) score was 96 points (range, 80 to 100). All patients achieved Minimal Clinically Important Difference improvement in their HHS and HOOS scores. There were 99 (85%) hip resurfacing procedures achieving a satisfactory PASS and 72 (69%) patients were active in sports. ConclusionHip resurfacing is a highly technical procedure. Careful implant selection is required. The meticulous preoperative planning, careful extensile surgical exposure, and exacting implant placement in this study likely contributed to the favorable results achieved. Hip resurfacing allows THA as a future option in patients where the lifetime revision rate is a major consideration.

Rectangular Taper Stem Designs Are Associated With a Higher Risk for Periprosthstic Femoral Fractures After Cementless Total Hip Arthroplasty

BackgroundPeriprosthetic femoral fractures (PFFs) remain a major concern following cementless total hip arthroplasty (THA). This study aimed to evaluate the association between different types of cementless tapered stems and the risk of postoperative PFF. MethodsA retrospective review of primary THAs performed at a single center from January 2011 to December 2018 included 3,315 hips (2,326 patients). Cementless stems were classified according to their design. The incidence of PFF was compared between flat taper porous-coated stems (type A), rectangular taper grit-blasted stems (type B1), and quadrangular taper hydroxyapatite-coated stems (type B2). Multivariate regression analyses were performed to identify independent factors related to PFF. The mean follow-up duration was 61 months (range, 12 to 139). Overall, 45 (1.4%) postoperative PFFs occurred. ResultsThe incidence of PFF was significantly higher in type B1 stems than in type A and type B2 stems (1.8 versus 0.7 versus 0.7%; P = .022). Additionally, more surgical treatments (1.7 versus 0.5 versus 0.7%; P = .013) and femoral revisions (1.2 versus 0.2 versus 0%; P = .004) were required for PFF in type B1 stems. After controlling for confounding variables, older age, diagnosis of hip fracture, and use of type B1 stems were significant factors associated with PFF. ConclusionType B1 rectangular taper stems were found to have higher risks for postoperative PFF and PFF requiring surgical management than type A and type B2 stems in THA. Femoral stem geometry should be considered when planning for cementless THA in elderly patients who have compromised bone quality.