Cementless Stem Research Articles

The Effect of Surgical Approach and Femoral Prosthesis Type on Revision Rates Following Total Hip Arthroplasty: An Analysis of the Most Commonly Utilized Cementless Stems.

Compared with other total hip arthroplasty (THA) approaches, the anterior approach has an increased rate of revision for femoral-sided complications, and certain stems may increase this risk. The present study aimed to assess the outcome of THA by surgical approach, according to the femoral stem utilized in the procedure. Data from the Australian Orthopaedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for osteoarthritis via the anterior or posterior approach with use of 1 of 5 of the most common cementless femoral stems from January 2015 to December 2019. The primary outcome measures were the cumulative percent revision (CPR) for all causes and for femoral stem loosening and fracture. The CPR was compared between THAs performed via the anterior and posterior approaches for all stems and for each individual femoral stem, as well as between individual femoral stems for each approach. The study included 48,716 THAs performed with use of cementless stems, of which 22,840 utilized an anterior approach and 25,876 utilized a posterior approach. There was no difference in the all-cause CPR between the anterior and the posterior approach, but the anterior approach had a higher CPR for loosening (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.48 to 2.69; p < 0.001) and fracture (HR, 1.78; 95% CI, 1.34 to 2.35; p < 0.001). There was apparent variation in the CPR across the different cementless stems when an anterior approach was utilized. The Quadra-H (Medacta) had a higher all-cause CPR when compared with the Polarstem (Smith & Nephew; HR, 1.49; 95% CI, 1.16 to 1.91; p = 0.002) and Corail (DePuy Synthes; HR, 1.31; 95% CI, 1.00 to 1.70; p = 0.0478). Variation was less apparent with the posterior approach. THAs performed via the anterior approach had higher rates of revision for femoral stem loosening and fracture, with greater variation in outcomes between individual stems. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Total hip arthroplasty in patients with severe hip dysplasia and congenital pubic diastasis: report of two cases

BackgroundCongenital bladder exstrophy is a rare malformation which is often associated with pubic diastasis and hip dysplasia. We reported the case two patients who underwent total hip arthroplasty (THA) due to advanced osteoarthritis combined with large congenital pubic diastasis (> 10 cm).Case presentationThe first patient, a 39 years old woman with a pubic diastase and severe hip dysplasia on both sides was treated with a primary two-staged bilateral THA. Both hips were treated with a cementless osteoconductive cup (TM, Zimmer-Biomet) and a cementless stem (Alloclassic SL, Zimmer-Biomet). A 10° elevated rim liner of the cup was used in order to avoid dislocation. The main problem was represented by the fixation of the cup, given the retroverted acetabulum along with the elevated rotation centre due to the dysplastic hips. In the case two, a 52 years woman presented dysplastic osteoarthritis of the left hip. A conventional hemispherical cup (Alloclassic-Allofit, Zimmer-Biomet) was placed in the retroverted acetabulum combined with a cementless stem (Fitmore A, Zimmer-Biomet) attached at the metaphyseal proximal femur bone.ConclusionOur results suggest that THA may be a good strategy to manage advanced hip osteoarthritis in patients with dysplasia and congenital pubic diastasis.Level of evidenceIV, case series.

Total hip arthroplasty with ultra-short uncemented stem in patients with osteonecrosis of the femoral head: mid-term results.

Mid-term results (clinical and radiographic) of ultra-short anatomical cementless stem total hip arthroplasty (THA) in patients with osteonecrosis of the femoral head (ONFH) has not often been presented. The aim of this study is to evaluate THA using the Proxima stem in patients with ONFH in the mid-term. The study consists of 73 patients (97 THAs) with a Proxima stem implanted between 2006 and 2015. The mean age of patients was 47.4 years, with a mean follow-up 105.2 months. The clinical results include preoperative and postoperative Harris Hip Scores (HHSs). Radiological follow-up reports on stem migration, bony trabecular development and radiolucent lines. The complications and revisions were registered. Kaplan-Meier survival analysis was performed to determine the implant survival. The average HHS improved significantly from 40.3 preoperatively to 98.0 at the final evaluation (p ˂ 0.0001). Stem migration (subsidence and "varisation") was observed in 11 hips (in 9 of them up to 6th postoperative month without any further progression, in 2 with progressive migration and radiological loosening). Bony trabecular development was detected in modified Gruen zones (1,2,4,6,7 for Proxima stem): in zone 1 (0%), 2 (67.0%), 4 (64.9%), 6 (64.9%), 7 (0%). Radiolucent lines were observed in 1 cup and 6 stems (2 were loose, 4 with fibrous stable fixation). Complications were found in 5 hips (5.1%): squeezing hip once, repeated dislocation in 1, 1 early deep infection, and 2 loose stems. 2 hips (2.1%) were revised (dislocation, infection). The implant survival was 98.9% and 97.9% clinically and radiologically, respectively. Observations in the mid-term show that the clinical and radiological results of the Proxima stem in patients with ONFH are promising. The stem design preserves the proximal femoral bone stock. The bony trabecular appearance confirms physiological proximal femoral load transmission.

Pneumatic femoral broaching decreases post-operative subsidence of a cementless taper-wedge stem.

Stem subsidence is a known cause of early failure in cementless total hip arthroplasty (THA). The aim of this study was to determine the usefulness of pneumatic femoral broaching in preventing post-operative subsidence of a proximally porous-coated, taper-wedge stem. We reviewed 169 cases of primary THA with a single taper-wedge stem. Eighty THAs performed using pneumatic broaching were compared with 89 THAs performed using manual broaching in terms of postoperative canal fill ratio (CFR) at three levels, stem subsidence at oneyear post-operation, and stem fixation at latest follow-up (median, 24months). The median CFRs were higher in the pneumatic group than in the manual group at all levels (p < 0.05). The median stem subsidence at oneyear after THA was lower in the pneumatic group than in the manual group (0.2mm vs. 0.6mm, p = 0.007). A multivariate analysis determined a decreased CFR at 60mm below the lesser trochanter and the manual broaching as independent factors affecting post-operative stem subsidence. At the latest follow-up, all stems showed stable fixation by bone ingrowth in both groups. Our results showed that the pneumatic broaching device was useful in maximizing the mediolateral canal filling and initial stability and minimizing the subsidence of taper-wedge stems.

How Does Implant Survivorship Vary with Different Corail Femoral Stem Variants? Results of 51,212 Cases with Up to 30 Years Of Follow-up from the Norwegian Arthroplasty Register.

How Does Implant Survivorship Vary with Different Corail Femoral Stem Variants? Results of 51,212 Cases with Up to 30 Years Of Follow-up from the Norwegian Arthroplasty Register.

Cementless Fixation Is Associated With Increased Risk of Early and All-Time Revision After Hemiarthroplasty But Not After THA for Femoral Neck Fracture: Results From the American Joint Replacement Registry.

Despite ample evidence supporting cemented femoral fixation for both hemiarthroplasty and THA for surgical treatment of displaced femoral neck fractures, cementless fixation is the preferred fixation method in the United States. To our knowledge, no nationally representative registry from the United States has compared revision rates by fixation for this surgical treatment. After controlling for relevant confounding variables, is femoral fixation method (cemented or cementless) in hemiarthroplasty or THA for femoral neck fracture associated with a greater risk of (1) all-cause revision or (2) revision for periprosthetic fracture? Patients with Medicare insurance who had femoral neck fractures treated with hemiarthroplasty or THA reported in the American Joint Replacement Registry database from 2012 to 2017 and Centers for Medicare and Medicaid Services claims data from 2012 to 2017 were analyzed in this retrospective, large-database study. Of the 37,201 hemiarthroplasties, 42% (15,748) used cemented fixation and 58% (21,453) used cementless fixation. Of the 7732 THAs, 20% (1511) used cemented stem fixation and 80% (6221) used cementless stem fixation. For both the hemiarthroplasty and THA cohorts, most patients were women and had cementless femoral fixation. Early revision was defined as a procedure that occurred less than 90 days from the index procedure. All patients submitted to the registry were included in the analysis. Patient follow-up was limited to the study period. No patients were lost to follow-up. Due to inherent limitations with the registry, we did not compare medical complications, including deaths attributed directly to cemented fixation. A logistic regression model including the index arthroplasty, age, gender, stem fixation method, hospital size, hospital teaching affiliation, and Charlson comorbidity index score was used to determine associations between the index procedure and revision rates. For the hemiarthroplasty cohort, risk factors for any revision were cementless stem fixation (odds ratio 1.42 [95% confidence interval 1.20 to 1.68]; p < 0.001), younger age (OR 0.96 [95% CI 0.95 to 0.97]; p < 0.001), and higher Charlson comorbidity index (OR 1.06 [95% CI 1.02 to 1.11]; p = 0.004). Risk factors for early revision were cementless stem fixation (OR 1.77 [95% CI 1.43 to 2.20]; p < 0.001), younger age (OR 0.98 [95% CI 0.97 to 0.99]; p < 0.001), and higher Charlson comorbidity index (OR 1.09 [95% CI 1.04 to 1.15]; p < 0.001). Risk factors for revision due to periprosthetic fracture were cementless fixation (OR 6.19 [95% CI 3.08 to 12.42]; p < 0.001) and higher Charlson comorbidity index (OR 1.16 [95% CI 1.06 to 1.28]; p = 0.002). Risk factors for early revision due to periprosthetic fracture were cementless fixation (OR 7.38 [95% CI 3.17 to 17.17]; p < 0.001), major teaching hospital (OR 2.10 [95% CI 1.08 to 4.10]; p = 0.03), and higher Charlson comorbidity index (OR 1.20 [95% CI 1.09 to 1.33]; p < 0.001). For the THA cohort, there were no associations. These data suggest that cemented fixation should be the preferred technique for most patients with displaced femoral neck fractures treated with hemiarthroplasty. The fact that stem fixation method did not affect revision rates for those patients with displaced femoral neck fractures treated with THA may be due to current practice patterns in the United States. Level III, therapeutic study.

Cementless total hip arthroplasty with anatomic-shaped implants. Does the minimal invasive anterolateral technique influence the stem position or subsidence in contrast to the standard lateral approach?

Using cementless stems in total hip arthroplasty (THA) has revealed variable results. The risk for early aseptic loosening has been associated to certain surgical approaches and implant designs. This study determines misalignment of collared/collarless stems and the rate of subsidence using the anterolateral approach (ALA) compared to implantations via the direct lateral approach (DLA). One hundred consecutive patients underwent primary unilateral THA using the minimal invasive ALA in the lateral decubitus position and were compared to another cohort of 100 patients, treated trough the DLA. Clinical results were noted preoperatively and after 1year using the WOMAC score. The radiographic evaluation included the stem alignment and subsidence. Overall, all patients improved in WOMAC from 48.9 points (± 11.4; 21.0-82.0) to 3.1 (± 3.2; 0.0-22.0) (p < 0.001). For DLA and ALA, the stem was placed on average 2.5° in varus to the femoral axis. The mean alignment was about 0.5° more valgus for collarless stems. The mean subsidence in the DLA group was about 0.3mm higher compared to the ALA group. With collarless implants, the subsidence was about 1.0mm higher compared to collared implants (p < 0.05), especially in patients with Dorr type B femurs. Changing from the DLA to the minimal invasive ALA did not significantly affect the implant position. Misalignment and a potential risk for early aseptic loosening could not be seen. The use of a collared cementless stem seems safe and is likely to prevent a relevant subsidence, even more so in Dorr type B femurs. III.

Handheld computer-navigated constrained total knee arthroplasty for complex extra-articular deformities.

The present study aimed to assess the postoperative alignment and clinical outcomes of patients with complex extra-articular deformities (EADs) undergoing computer-assisted surgery (CAS) for constrained total knee arthroplasty (TKA) with modular stem extensions. From May 2015 to July 2018, ten patients with EADs scheduled for constrained TKA were enrolled retrospectively. The preoperative average deviation from neutral (= 180°) mechanical axis was 15.3° (range of coronal alignment: 150.9° varus-202.9° valgus). Alignment was assessed using an accelerometer-based handheld CAS system. On long-leg films, the positions of the components and possible stems were analysed and templated preoperatively. The average follow-up was 3.3years (range: 2.0-4.6years). The postoperative mechanical axis was within ± 3.0° from neutral in nine patients. In all patients, the Knee Society score (KSS) and range of motion improved significantly. A constrained condylar and a rotating hinge prosthesis were used in five patients each. In eight patients, the 100-mm cementless stem that was preferred by the authors was found to be unusable for the femur or the tibia in the planning stage. For the femur, a cementless 100-mm stem was used in three, and a cemented 30-mm stem in five patients; a femoral stem was not usable in two patients. For the tibia, a cementless 100-mm stem was used in six, and a cemented 30-mm stem in two patients; a monoblock rotating hinge tibia was used in two patients. Complex EADs were excellently managed during constrained TKA implantation using the handheld CAS system. Templating allowed the possible stem lengths to be identified and prevented anatomical conflict with the CAS-configured mechanical alignment. Limb alignment and function improved significantly after surgery. No intra- or postoperative complications occurred. Level IV, retrospective study.

Digital templating for the implantation of a curved short hip stem with an anterolateral MIS approach shows gender differences in digital templating

PurposeDigital templating shows reliable accuracy for straight stem systems. In recent years, the implantation of short stems through minimally invasive approaches has gained more popularity. Minimally invasive approaches (MIS) show the risk of undersizing femoral components. Therefore, we questioned the planning adherence for a curved short stem and a bi-hemispherical acetabular cup implanted through an anterolateral MIS approach.MethodsA consecutive series of 964 hips (index surgery between 2014 and 2019) with Fitmore® curved short stem and Allofit/-S® acetabular cup (both ZimmerBiomet Inc, Warsaw, IN) were included. Preoperative digital templating was conducted anterior–posterior (AP) digital radiographs of the hip using mediCAD® version 5.1 (Hectec GmbH, Altdorf, Germany). The templates of acetabular and femoral components (offset option and stem size) were retrospectively evaluated for general adherence, and according to sex, BMI and planner’s experience.ResultsPlanning adherence for the exact offset option was 70.6 and 21.6% for exact offset option and stem size. Adherence for acetabular cup ± 1 size was 74.8%. A significant difference between male and female patients for the offset option could be found (p = 0.03, z = −2983). In 22.5% of male patients, an offset option one size higher and in 12.3% of female patients an offset option one size smaller than templated was used intraoperativelyConclusionDigital templating for the Fitmore® stem in cementless THA with a minimally invasive anterolateral approach shows comparable planning adherence to the existing literature for this cementless short stem. However, a lower planning adherence was detected compared to conventional straight stem systems. In male patients, the femoral offset is frequently undersized and in female patients frequently oversized compared to the preoperative plan. Surgeons should be aware of this difficulty in digital templating for Fitmore® hip stem.

Bone Strength and Viscoelasticity Affect Cementless Femoral Stem Fixation: Commentary on an article by Hannu T. Aro, MD, PhD, et al.: "Volumetric Bone Mineral Density in Cementless Total Hip Arthroplasty in Postmenopausal Women. Effects on Primary Femoral Stem Stability and Clinical Recovery".

Bone Strength and Viscoelasticity Affect Cementless Femoral Stem Fixation: Commentary on an article by Hannu T. Aro, MD, PhD, et al.: "Volumetric Bone Mineral Density in Cementless Total Hip Arthroplasty in Postmenopausal Women. Effects on Primary Femoral Stem Stability and Clinical Recovery".

Long-term outcomes of cementless femoral stem revision with the Wagner cone prosthesis

BackgroundThe procedure of femoral stem revision is challenging, and bone conservation with less stress shielding is a mandatory effort in these cases. Although there are several reports of stem revision with stems designed for primary total hip arthroplasty (THA), there is no report on stem revision with the Wagner cone prosthesis.MethodsBetween 1996 and 2008, 41 hips of 41 consecutive patients were subjected to femoral revision THA using the Wagner cone prosthesis. The mean age during revision surgery was 56.1 years, and the mean follow-up period was 14.8 years. The clinical results were evaluated, and the femoral component was assessed radiologically.ResultsThe results showed that the average period from the first operation to revision THA was 8.0 years. Additionally, the mean Harris hip score improved from 52 points preoperatively to 83 points at the final follow-up. All stems showed bone integration in the radiological evaluation. A subsidence of more than 5 mm was observed in 3 out of 28 (10.7%) femoral stems. Two patients needed an acetabular revision for acetabular cup loosening during the follow-up period. Furthermore, one patient had recurrent dislocation and had to undergo revision surgery for soft tissue augmentation.ConclusionsWe achieved favorable clinical and radiological long-term outcomes in femoral stem revision using the Wagner cone prosthesis. This cementless femoral stem could be an option for femoral stem revision in cases with relatively good bone stock.

Comparison of short-stem versus conventional stem for hip arthroplasty in patients younger than 60years: 7-14years follow-up.

Short-stem prostheses in hip arthroplasty have emerged as an alternative to conventional stems, especially in younger patients. The purpose of this study was to compare functional and radiological results of a short metaphyseal fitting cementless stem versus a conventional stem implant, in patients younger than 60years. All patients operated from January 2006 to April 2013 were included, obtaining a minimum follow-up of 7years. Harris Hip Score (HHS) and SF-36 (quality of life) questionnaires were applied and the presence of "thigh pain" was specifically assessed. We also compared complication rate, revision rate and average prosthesis survival. Femoral stress shielding (Gruen scale), stem subsidence, varus-valgus tilt and implant stability (Engh scale) were also compared. A total of 101 short-stem and 74 conventional arthroplasties were included, with an average follow-up of 9.82 (7-14) years. HHS functional score and SF-36 were excellent in both implants and no significant difference between them (p > 0.05) was found. However, "thigh pain" was present in 7 patients with conventional stems and none with short-stems (p < 0.001). The survival rate at 13years was 99%, for both implants, and no significant differences were found between them (χ2(2) = 0.178; p = 0.673). Conventional stems had stress shielding at the greater trochanter in 72% of the cases and 43% at the calcar, being statistically superior (p < 0.001) to the stress shielding observed in the short stems. According to our results, this short-stem seems to allow preservation of bone stock, with decreased stress shielding and also a lower incidence of thigh pain compared to conventional stems. Level III retrospective comparative study.

Survivorship of Ceramic-on-Ceramic Total Hip Arthroplasty With Metal-Backed Acetabular Liners at 10 Years

BackgroundCeramic-on-ceramic bearings are becoming increasingly popular in primary total hip arthroplasty (THA). To enhance ceramic-on-ceramic liner exchange in case of revision surgery, metal-backed liner systems have been proposed. Little is known about the clinical performance of these implants. The purpose of this study is to evaluate a metal-backed liner implant system for primary THA. MethodsA total of 422 patients (with 468 consecutive THAs) were followed over a mean period of 10 years. All arthroplasties were performed with a cementless stem, a press-fit cup, and a metal-backed liner system. Surgical and clinical data, complications, and revisions were analyzed. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) before surgery and at 1 and 10 years after surgery were compared. ResultsThe overall 10-year implant survival rate was 93.8%. The survival rate was 97.0% for heads and liners, 97.5% for stem, and 99.3% for acetabular cup. The most common reason for revision was ceramic breakage (2.4%) of the third-generation (BIOLOX forte) acetabular liner. Mean WOMAC score improved significantly from 50.1 before surgery to 13.2 at 1 year after surgery. There was no difference in WOMAC scores between surgical approach and type of bearing at 1 and 10 years after surgery. ConclusionTHA using cementless stem, press-fit cup, and metal-backed liner system provides satisfactory long-term outcomes, with revision rate comparable to that with other systems available in the market. The metal-backed liner system has low risk of mal-seating. Third-generation ceramic liners should be avoided as they seem to be more prone to breakage.

Differences in femoral component subsidence rate after THA using an uncemented collarless femoral stem: full weight-bearing with an enhanced recovery rehabilitation versus partial weight-bearing

BackgroundFemoral component subsidence is a known risk factor for early failure of total hip arthroplasty (THA) using cementless stems. The aim of the study was to compare an enhanced recovery concept with early full weight-bearing rehabilitation and partial weight-bearing on stem subsidence. In addition, the influence of patient-related and anatomical risk factors on subsidence shall be assessed.MethodsOne hundred and fourteen patients underwent primary cementless THA and were retrospectively analyzed. Sixty-three patients had an enhanced recovery rehabilitation with early full weight-bearing and 51 patients had rehabilitation with partial weight-bearing (20 kg) for 6 weeks. Postoperative subsidence was analyzed on standing pelvic anterior–posterior radiographs after 4 weeks and 1 year. Subsidence was measured in mm. Anatomical and prosthetic risk factors (stem size, canal flare index, canal fill ratio as well as BMI and demographic data) were correlated.ResultsFemoral stem subsidence rate was significantly higher for the group with an enhanced recovery concept compared to the group with partial weight-bearing at the first radiological follow up after 4 weeks [2.54 mm (SD ± 1.86) vs. 1.55 mm (SD ± 1.80)] and the second radiological follow up after 1 year [3.43 mm (SD ± 2.24) vs. 1.94 (SD ± 2.16)] (p < 0.001, respectively). Stem angulation > 3° had a significant influence on subsidence. Canal flare index and canal fill ratio showed no significant correlation with subsidence as well as BMI and age.ConclusionIn the present study, cementless stem subsidence was significantly higher in the group with enhanced recovery rehabilitation compared to partial weight-bearing. Small absolute values and differences were demonstrated and therefore possibly below clinical relevance. Anatomical radiological parameters and anthropometric data did not appear to be risk factors for stem subsidence.

Long-Term Survivorship of Modular Cementless Femoral Stem in Complex Primary Total Hip Arthroplasty: A Concise Minimum 15-Year Follow-Up Report

BackgroundS-ROM hip is a well-established and versatile prosthesis that offers extensive metaphyseal and diaphyseal geometries providing solutions for a variety of surgical scenarios. The aim of this study is to report on long-term survivorship and radiographic outcomes of complex primary total hip arthroplasty (THA) using a modular cementless stem (S-ROM). MethodsRetrospective consecutive study was conducted of 167 patients (167 hips): 97 males and 70 females with average age at the time of surgery of 55 years (range 22-76). All patients underwent complex THA by the senior author from 1987 to 1999. Patients were identified using a prospective database. Demographic, clinical, and surgical data were collected from health records. All patients received a cementless acetabular component with a standard polyethylene liner. The primary outcome measure was survivorship beyond 15 years using stem revision for any cause as an end point. Secondary outcome measure was rate of radiographic loosening using Engh classification. ResultsOnly 3 patients required stem revision for aseptic loosening and 1 for periprosthetic fracture. Isolated acetabular revision was undertaken in 23 of 167 patients (13.8%) due to polythene wear, osteolysis, and aseptic loosening. Proximal femoral stress shielding (zone 1, 7) was noted in 34 of 167 hips (20.4%). Stable bony ingrowth was noted in 144 hips (86.2%) and the remaining 23 hips had stable fibrous ingrowth (13.8%). Using stem “any-cause revision” as an endpoint, the mean stem survivorship was 31.5 years (95% confidence interval 31.007-31.985) with 30-year estimated survivorship of 97.6%. ConclusionIn a single designer surgeon series, S-ROM stem has stood the test of time with long-term, 30-year survivorship of 97.6% and continues to play an important role in modern hip surgery providing longevity and versatility. However, further comparative long-term studies from independent centers are needed for a definitive conclusion. Level of EvidenceIV.

Migration characteristics of the Corail hydroxyapatite-coated femoral stem\u2014a retrospective clinical evaluation and migration measurement with EBRA

PurposeUncemented stem migration analysis by EBRA-FCA (Einzel-Bild-Roentgen Analyse, Femoral Component Analysis) has been seen to be a good predictive indicator for early implant failure. In this study, we investigated the migration behavior of a cementless press-fit stem after two years follow-up. Stem type and postoperative gap between collar and femur were evaluated as a risk factor.MethodsApplying a retrospective study design, we reviewed all consecutive patients who between 2013 and 2017 received a cementless press-fit Corail stem (DePuy Orthopaedics Inc., Warsaw, IN, USA) at our Department. We reviewed medical histories and performed radiological measurements using EBRA-FCA software.ResultsA total of 109 stems in 105 patients (female: 60; male: 45) fulfilled our inclusion criteria. Mean age at surgery was 67.8 (range, 21.6–90.5) years. EBRA migration analysis showed a mean subsidence of 1.8 mm (range, 0.0–12.1) at final follow-up. At 18 months mean subsidence of collared stems was significantly lower than in the collarless group [1.3 mm (range, 0.0–7.6) vs. 3.2 mm (range, 0.5–10.7), p = 0.0104]. Collared stems resting on the femoral cut presented a tendency to less subsidence than did collared stems showing a postoperative gap between collar and femur (1.3 vs. 2.0 mm) without finding statistical significance (p > 0.05).ConclusionsLow subsidence and the migration pattern of the cementless press-fit stem may predict a good long-term result. Collared stems investigated in our study provide good stability and are able to prevent significant subsidence.Trial registration number and date of registration: Number: 20181024-1875; Date: 2018-10-24

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.

Assessment of Early Biological Fixation of Cementless Tapered-Wedge Stems Using Digital Tomosynthesis

BackgroundWe aimed to compare radiographic and digital tomosynthesis assessments of early biological fixation of a cementless stem in primary total hip arthroplasty and to investigate the factors associated with early biological fixation. MethodsSeventy-three patients underwent total hip arthroplasty using cementless short tapered-wedge stems. Both radiography and digital tomosynthesis were performed at 6 weeks and 3, 6, 12, and 24 months after surgery. The presence of spot welds (SW) was evaluated at each postoperative period to assess biological fixation between the stem and the femur. The area of contact between the femur and the stem was divided into seven zones based on Gruen’s zone classification. ResultsAll 73 patients had no SW 6 weeks after surgery on radiography and digital tomosynthesis. Three months postoperatively, there was no SW on radiography; however, digital tomosynthesis revealed SW in 31 (42%) patients. Six months postoperatively, radiography showed 22 SW in 18 (24.7%) patients and digital tomosynthesis showed 94 SW in 48 patients (65.8%). ConclusionDigital tomosynthesis detected biological fixation between the stem and femur earlier than radiography; biological fixation may appear within 3 months after surgery.

Comparison of radiographic changes in rectangular curved short stem with thin versus thick porous coating for cementless total hip arthroplasty: a retrospective study with a propensity score matching

BackgroundRadiographic changes that appear relatively quickly after fixation of cementless stem in total hip arthroplasty (THA) vary depending on the stem design and fixation style. The present study compared radiographic changes between two types of rectangular curved short stems of similar shape.MethodsThis retrospective study included 118 hips that underwent primary cementless THA with an anterolateral supine approach using a rectangular, curved, short stem performed by the same surgeon between June 2015 and June 2019. Among the examined hips, 39 had a thicker porous coating stem (thicker group) and 66 had a thinner porous coating and reduced tip stem (thinner group) and at least 12-month follow-up. Radiographs taken during the final course observation were assessed. Propensity score matching was performed based on demographic data and comparisons were made using pairs of 25 hips each. Statistical analysis was performed using chi-square test and p values ≤ 0.05 indicated statistical significance.ResultsThe pattern of the radiolucent lines showed a significant difference after matching (p = 0.0044). A “proximal and distal” pattern was most common in the thicker group and a “distal only” pattern was most common in the thinner group. There was notable and significant difference in cortical hypertrophy in the thicker group after matching (p = 0.024).ConclusionsAlthough the two short stems were similar shapes, the short-term radiographic changes were different. The thinner group showed fewer radiographic changes than the thicker group, making it a more “silent” stem.

Humeral osteolysis after reverse shoulder arthroplasty using cemented or cementless stems comparative retrospective study with a mean follow-up of 9 years

IntroductionThe cause of proximal humeral osteolysis after reverse shoulder arthroplasty (RSA) remains controversial. The primary objective of our study was to compare the radiographic outcomes of Grammont-type RSA when a cemented stem is used versus when a cementless stem is used. The secondary objective was to identify the cause of these radiographic changes, especially for the cementless stems. HypothesisMore proximal humerus bone loss occurs when a cementless humeral stem is used. MethodsWith a minimum follow-up of 5 years, two paired cohorts were compared retrospectively: 70 RSA with cemented stem and 70 RSA with cementless stem. Using the radiographs made at the final follow-up visit, we looked for tuberosity resorption, signs of stress shielding, the presence of periprosthetic radiolucent lines and scapular notching. ResultsAt a mean follow-up of 9 years (5.0–20.6), the RSA revision rate was 1.8% in the cemented group and 3.6% in the cementless group (p=1). Tuberosity resorption was twice as common in the cementless group: 59% versus 30% (p<0.001). Signs of stress shielding such as osteopenia were only present in the cementless group. In both groups, tuberosity resorption was often associated with scapular notching. In the shoulders with tuberosity resorption, stage≥3 scapular notching was more common in the cementless group (p=0.001). DiscussionFor the cementless stems, proximal humeral osteolysis can in part be attributed to stress shielding. The relationship between notching and tuberosity resorption in the two groups also suggests a secondary biological cause. Level of evidenceIII; Comparative retrospective study.