Rate Of Loosening Research Articles

S1 vertebral bone quality score independently predicts pedicle screw loosening following surgery in patients with adult degenerative scoliosis

BACKGROUND CONTEXTMRI-based vertebral bone quality (VBQ) score is an effective predictor of pedicle screw loosening after lumbar fusion surgery and has been recognized as a valuable tool for assessing preoperative bone quality. Due to the lateral curvature of lumbar spine of degenerative scoliosis, accurate measurement of VBQ score by conventional measurement methods that capture MRI signal intensity at L1–4 may be limited under certain conditions. To this end, a new simplified S1 VBQ score method has been proposed, which is comparable to the previous L1–4 VBQ score or S1 Hounsfield unit (HU) value, and has high accuracy and reliability. PURPOSETo evaluate the predictive value of MRI-based S1 VBQ score for pedicle screw loosening following surgery for adult degenerative scoliosis (ADS). STUDY DESIGN/SETTINGRetrospective single-center cohort. PATIENT SAMPLEWe reviewed 92 patients who underwent posterior lumbar interbody fusion (PLIF) with pedicle screw fixation for ADS between January 2017 and January 2020. OUTCOME MEASURESAssociation between S1 VBQ score and pedicle screw loosening following surgery for ADS. METHODSWe retrospectively reviewed the records of all patients who performed PLIF between January 2017 and January 2020. The clear zone around pedicle screws≥1 mm can be identified as screw loosening. The S1 VBQ score is calculated from the S1 central-based noncontrast T1-weighted magnetic resonance imaging (MRI). The signal intensity (SI) of the cerebrospinal fluid (CSF) was then measured using ROI placed at the L3 level to normalize the results. Multivariate logistic regression analysis was performed to identify independent risk factors for screw loosening. Then, constructed a receiver operating characteristic (ROC) curve and determined the threshold (cut-off) of VBQ score with high sensitivity and specificity based on Youden Index. RESULTSA total of 92 patients were included, including 34 males and 58 females. The mean age of the patients was 61.23±1.23 years old. At 1-year follow-up, the screw loosening rate was 56.5% (52/92). The age and levels of fixation were higher in the loosening group than in the nonloosening group (p=.036, p=.025). Patients in the loosening group had a greater VBQ score compared to patients in the nonloosening group (3.31±0.41 vs 3.01±0.28, p=.001). Multivariate logistic regression analysis showed that advanced age (OR, 1.090; 95% CI 1.005–1.183; p=.039) and higher VBQ score (OR, 5.778; 95% CI 2.889–16.177; p=.001) were independent risk factors for screw loosening. In addition, the ROC curve were created to assess the role of VBQ score as predictors of screw loosening with a diagnostic accuracy of 74.6% (95% CI 64.2%–85.1%).The most suitable threshold for the VBQ score as determined by the Youden Index was 3.175 (sensitivity: 76.0%, specificity: 83.3%). CONCLUSIONSHigher S1 VBQ score was significantly associated with pedicle screw loosening following surgery for ADS. The S1 VBQ score can be used as an effective preoperative predictor, which has the potential clinical application.

The Effect of Osteoporosis on Complications and Reoperation Rates After Surgical Management of Adult Thoracolumbar Spinal Deformity: A Systematic Review and Meta Analysis.

Systematic Review. While substantial research has explored the impact of osteoporosis on patients undergoing adult spinal deformity (ASD) correction, the literature remains inconclusive. As such, the purpose of this study is to synthesize and analyze existing studies pertaining to osteoporosis as a predictor of postoperative outcomes in ASD surgery. We performed a systematic review and meta-analysis to determine the effect that a diagnosis of osteoporosis, based on ICD-10 coding, dual-energy X-ray absorptiometry (DEXA) or computed tomography, has on the incidence of adverse outcomes following surgical correction of ASD. Statistical analysis was performed using Comprehensive Meta-Analysis (Version 2) using a random effects model to account for heterogeneity between studies. After application of inclusion and exclusion criteria, 36 and 28 articles were included in the systematic review and meta-analysis, respectively. The meta-analysis identified greater rates of screw loosening amongst osteoporotic patients (70.5% vs 31.9%, P = .009), and decreased bone mineral density in patients who developed proximal junctional kyphosis (PJK) (.69 vs .79g/cm2, P = .001). The systematic review demonstrated significantly increased risk of any complication, reoperation, and proximal junctional failure (PJF) associated with reduced bone density. No statistical difference was observed between groups regarding fusion rates, readmission rates, and patient-reported and/or functional outcome scores. This study demonstrates a higher incidence of screw loosening, PJK, and revision surgery amongst osteoporotic ASD patients. Future investigations should explore outcomes at various follow-up intervals in order to better characterize how risk changes with time and to tailor preoperative planning based on patient-specific characteristics.

Total Knee Arthroplasty in People with Hemophilia: Higher Incidence of Periprosthetic Joint Infection and 1-Year Revision/Re-Operation than the General Population and Lower Prosthetic Survival When Early Postoperative Bleeding Complications Occurred: Current Literature Review.

The purpose of this narrative review of the recent literature is to analyze the outcomes, complications, and implant survival of total knee arthroplasty (TKA) carried out on people with hemophilia (PWH). It has been shown that TKA substantially alleviates preoperative pain and improves knee function and the patient's quality of life. However, the complication rates of TKA range between 8.5% and 28.7, with postoperative hemarthrosis being the most frequent (7.6%). Besides, when comparing if the TKA was implanted before or after the year 2000, a reduction was found in the rates of periprosthetic joint infection-PJI (6.2% to 3.9%) and aseptic loosening (3.8% to 2.1%). Comparing prosthesis survival between PWH who had suffered early postoperative bleeding complications (EPBC) and patients who did not suffer EBPC, the mean survival duration was 17 years for the EPBC group and 22.1 years for the non-EPBC group. Survival rates were 80% for the EPBC group and 96.4% for the non-EPBC group. Compared to patients without hemophilia, PWH had a substantially higher incidence of PJI (Odds Ratio-OR 1.6) and 1-year revision/re-operation (OR 1.4). In short, although TKA substantially improves the quality of life of PWH, it is an intervention that has a non-negligible percentage of complications. TKA in PWH should preferably be performed only in highly specialized centers for the orthopedic treatment of hemophilia.

The Effect of C2 Muscular Exposure Technique on Radiographic and Clinical Outcomes After C2-T2 Posterior Cervical Fusion.

Retrospective cohort analysis. To determine whether the C2 exposure technique was a predictor of change in cervical alignment and patient-reported outcomes measures (PROMs) after posterior cervical decompression and fusion (PCDF) for degenerative indications. In PCDF handling of the C2 posterior paraspinal musculature during the operative approach varies by surgeon technique. To date, no studies have investigated whether maintenance of the upper cervical semispinalis cervicis attachments as compared with complete reflection of upper cervical paraspinal musculature from the posterior bony elements is associated with superior radiographic and clinical outcomes after PCDF. All adult patients who underwent C2-T2 PCDF for myelopathy or myeloradiculopathy at multi-institutional academic centers between 2013 and 2020 were retrospectively identified. Patients were dichotomized by the C2 exposure technique into semispinalis preservation or midline muscular reflection groups. Preoperative and short and long-term postoperative radiographic outcomes (upper cervical alignment, global alignment, and fusion status) and PROMs (Visual Analog Scale-Neck, Neck Disability Index, and Short Form-12) were collected. Univariate analysis compared patient factors, radiographic measures, and PROMs across C2 exposure groups. A total of 129 patients met the inclusion/exclusion criteria (73 muscle preservation and 56 muscle reflection). Patients in the muscular preservation group were on average younger (P= 0.005) and more likely to have bone morphogenic protein (P< 0.001) and C2 pars screws (P= 0.006) used during surgery. Preoperative to postoperative changes in C2 slope, C2 tilt, C2-C3 segmental lordosis, C2-C3 listhesis, C0-C2 Cobb angle, proximal junctional kyphosis, ADI, C1 lamina-occiput distance, C2 sagittal vertical axis, C2-C7 lordosis, and PROMs at all follow-up intervals did not vary significantly by C2 exposure technique. Likewise, there were no significant differences in fusion status, C2-C3 pseudoarthrosis, C2 screw loosening, and complication and revision rates between C2 exposure groups. Preservation of C2 semispinalis attachments versus muscular reflection did not significantly impact cervical alignment, clinical outcomes, or proximal junction complications in long-segment PCDF. Level III.

Cementless total knee arthroplasty in young patients using tantalum trabecular implants results in significantly lower rates of aseptic loosening.

The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery. A total of 454 consecutive patients who underwent cementless TKA between August 2004 and December 2021 were reviewed. The mean follow-up was ten years. Plain radiographs were analyzed for radiolucent lines. Patients who underwent revision TKA were recorded, and the cause for revision was determined. Data from the National Joint Registry for England, Wales, Northern Island, the Isle of Man and the States of Guernsey (NJR) were compared with our series. No patients in our series had evidence of radiolucent lines on their latest radiological assessment. Only eight patients out of 454 required revision arthroplasty, and none of these revisions were indicated for aseptic loosening of the tibial baseplate. When compared to data from the NJR annual report, Kaplan-Meier estimates from our series (2.94 (95% confidence interval (CI) 1.24 to 5.87)) show a significant reduction in cumulative estimates of revision compared to all cemented (4.82 (95% CI 4.69 to 4.96)) or cementless TKA (5.65 (95% CI 5.23 to 6.10)). Our data (2.94 (95% CI 1.24 to 5.87)) also show lower cumulative revision rates compared to the most popular implant (PFC Sigma Cemented Knee implant fixation, 4.03 (95% CI 3.75 to 4.33)). The prosthesis time revision rate (PTIR) estimates for our series (2.07 (95% CI 0.95 to 3.83)) were lower than those of cemented cases (4.53 (95% CI 4.49 to 4.57)) from NJR. The NexGen trabecular (tantalum) cementless implant has lower revision rates in our series compared to all cemented implants and other types of cementless implants, and its use in younger patients should be encouraged.

The effect of C2 screw type on perioperative outcomes and long-term stability after C2-T2 posterior cervical decompression and fusion.

To determine if C2 pedicle versus pars screw type predicts change in fusion status, C2 screw loosening, cervical alignment, and patient-reported outcomes measures (PROMs) after C2-T2 posterior cervical decompression and fusion (PDCF). All adult patients who underwent C2-T2 PCDF for myelopathy or myeloradiculopathy between 2013-2020 were retrospectively identified. Patients were dichotomized by C2 screw type into bilateral C2 pedicle and bilateral C2 pars screw groups. Preoperative and short- and long-term postoperative radiographic outcomes and PROMs were collected. Univariate and multivariate analysis compared patient factors, fusion status, radiographic measures, and PROMs across groups. A total of 159 patients met the inclusion/exclusion criteria (76 bilateral pedicle screws, 83 bilateral pars screws). Patients in the C2 pars relative to C2 pedicle screw group were on average more likely to have bone morphogenic protein (p = 0.001) and four-millimeter diameter rods utilized intraoperatively (p = 0.033). There were no significant differences in total construct and C2-3 fusion rate, C2 screw loosening, or complication and revision rates between C2 screw groups in univariate and regression analysis. Changes in C2 tilt, C2-3 segmental lordosis, C0-2 Cobb angle, proximal junctional kyphosis, atlanto-dens interval, C1 lamina-occiput distance, C2 sagittal vertical axis, C2-7 lordosis, and PROMs at all follow-up intervals did not vary significantly by C2 screw type. There were no significant differences in fusion status, hardware complications, and radiographic and clinical outcomes based on C2 screw type following C2-T2 PCDF. Accordingly, intraoperative usage criteria can be flexible based on patient vertebral artery positioning and surgeon comfort level.

Reemplazo total de cadera en pacientes menores de 50 años: ¿tiene la fijación no cementada mejores resultados?

BackgroundCementless fixation for hip arthroplasties has increased in the last decades, particularly in younger patients. The purpose of this study was to compare the long-term results three different types of fixations in patients under 50years old. MethodsCemented, hybrid and cementless fixations were assessed in patients under 50years old with a minimum follow-up of 8years. Loosening, demarcation, complications, and prosthesis survival were assessed. Functional analysis was performed with the modified Harris Hip Score and Visual analogue scale was collected. ResultsFinal series consisted in 222 patients. Significant improvement was observed regarding mHHS and VAS score in each group. We observed statistically significant difference regarding demarcation between the groups (P<.001). The higher rate of acetabular and femoral stem loosening was observed in the cemented (20.0%) and hybrid (18.9%) group. The lowest prosthesis survival rate after 16 years was observed in hybrid group (P<.001). ConclusionTotal hip replacement has good long-term clinical and functional outcomes. The lowest rate of prosthesis survival was observed in hybrid group with 84.2% after 16years.

A comparison of cemented femoral fixation via anterior versus posterior approach total hip arthroplasty: an analysis of 60,739 total hip arthroplasties.

Anterior approach total hip arthroplasty (THA) decreases the rate of dislocation but increases femoral-sided complications in the way of periprosthetic fractures and component loosening. A cemented prosthesis may reduce femoral-sided complications and improve the risk:benefit profile of anterior approach THA. Data from the Australian National Joint Replacement Registry were analysed for patients undergoing primary THA via the anterior or posterior approach using a cemented polished femoral stem from January 2015 to December 2021. The primary outcome measure was the cumulative percent revision (CPR) for all causes and CPR for femoral component loosening and fracture. The CPR for the primary outcome measures were compared between the anterior and posterior approach and adjusted for age, sex, ASA score, BMI and femoral head size. The study included 60,739 THAs with cemented stems (10,742 anterior, 49,997 posterior). The rate of revision of the anterior versus the posterior approach did not significantly differ (HR 0.87 (95% CI, 0.74-1.03), p = 0.100). Anterior approach THA had a significantly higher rate of revision for femoral component loosening (HR 5.06 [95% CI, 3.08-8.30], p < 0.001); and a decreased rate of revision for infection (HR 0.59 [95% CI, 0.43-0.81], p = 0.001) and dislocation/instability (HR 0-3 months 0.48 [95% CI, 0.27-0.83], p = 0.008; HR >3 months 0.30 [95% CI, 0.15-0.61], p < 0.001). There was no difference in the rate of revision surgery for fracture between the 2 approaches (HR 1.01 [95% CI, 0.71-1.43]), p = 0.975). There is no significant difference in overall revision rates with cemented femoral fixation performed with an anterior or posterior approach. Cemented fixation performed with the anterior approach partly mitigates femoral complications with no difference in the revision rate for fracture but an increased rate of femoral component loosening.

Humeral stem loosening is not always prosthetic joint infection

BackgroundAseptic humeral stem loosening is an uncommon complication of shoulder arthroplasty, and its presence has been considered a highly specific predictor of prosthetic joint infection (PJI). Literature on aseptic humeral stem loosening is sparse. The primary purpose of this study was to determine the rate of aseptic humeral loosening in revision shoulder arthroplasty. Secondarily, we sought to identify predictors of septic and aseptic humeral loosening. MethodsOur institutional revision shoulder arthroplasty database was reviewed. Inclusion criteria were patients with humeral stem loosening as indicated in the operative report. Patient demographics, index surgery and indication, revision surgery and indication, and operative data were recorded. Charts were manually reviewed, and PJI scores were calculated using the International Consensus Meeting (ICM) scoring criteria. ICM classifications of PJI “unlikely” and “possible” were considered aseptic, and PJI “probable” and “definite” were considered septic. Statistical analysis was performed to determine associations between the abovementioned variables and aseptic humeral loosening. ResultsForty-six patients with forty-eight shoulders were included in our analysis. Ten cases (21%) were classified as definite PJI, thirteen cases (27%) were classified as probable PJI, four cases (8%) were classified as possible PJI, and twenty-one cases (44%) were classified as PJI unlikely. On analysis of stem design, there were no statistically significant associations with aseptic loosening; although, a lack of proximal porous ingrowth surface trended toward higher rates of aseptic loosening in all patients and in ATSA and RTSA subgroup analyses. In the index RTSA subgroup, aseptic loosening was associated with female sex (p=0.005). Seventeen of 39 shoulders (44%) that underwent either index ATSA or RTSA demonstrated concomitant glenoid loosening. The absence of glenoid loosening was associated with aseptic humeral loosening in index ATSA and RTSA (p<0.001). Conclusion52% of revision shoulder arthroplasty cases with humeral loosening performed at our institution were aseptic. There appear to be distinct demographic and radiographic factors that are more commonly associated with aseptic as opposed to septic humeral loosening. Our data demonstrate that demographic predictors of aseptic loosening of RTSA include female sex. The absence of glenoid component loosening is associated with aseptic humeral loosening and concomitant glenoid loosening is associated with septic humeral loosening. Understanding of these factors can guide the preoperative index of suspicion for PJI in the setting of humeral stem loosening.

Patients with chronic kidney disease can expect significant improvement in pain and function after shoulder arthroplasty

BackgroundChronic kidney disease (CKD) is associated with negative outcomes after hip and knee arthroplasty due to higher rates of infection, aseptic loosening, and transfusion. The purpose of this study was to compare clinical outcome scores and complication rate after shoulder arthroplasty (SA) for patients with and without CKD. MethodsWe conducted a retrospective cohort study of prospectively collected data and reviewed all patients who underwent primary SA from January 2015 to December 2019 by one surgeon at one institution. Revision arthroplasty patients were excluded. We evaluated results from patients with CKD (glomerular filtration rate [GFR] ≤ 59) and without CKD (GFR ≥ 60). Outcome measures including visual analog scale for pain, American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST), and Single Assessment Numeric Evaluation (SANE) scores were compared between cohorts. Minimum clinically important difference (MCID) and substantial clinical benefit also were determined for this cohort. Univariate and multivariable regression was performed to assess the influence of CKD on outcome measures and risk of complications. Results518 patients met inclusion criteria; 4 patients did not have recorded GFR, leaving 514 patients for analysis. 389 patients had normal GFR; 125 had CKD. Patients with CKD had lower overall preoperative and postoperative ASES, SST, and SANE scores but demonstrated similar levels of clinical improvement from preoperative to postoperative time points (Δ ASES 41.4 ± 21.8 vs. 42.9 ± 21.4, P = .55), (Δ SST 4.8 ± 3.4 vs. 4.9 ± 3.3, P = .08), (Δ SANE 40.7 ± 29.1 vs. 42.4 ± 26.5, P = .77). Both cohorts achieved MCID for ASES, SST, and SANE scores. Univariately, patients with CKD were at high risk to require transfusion (OR 16.2 (1.9, 139.7), P = .01) despite similar intraoperative estimated blood loss (156.9 ± 132.5mL vs. 153.8 ± 89.7mL, P = .77). CKD patients also were at higher risk for intraoperative fracture (OR 5.4 (1.3, 23.0), P = .02). CKD patients were not at higher risk for prosthetic joint infection (OR 3.2 (0.2, 50.8), P = .42), medical complications (OR 0.9 (0.2, 4.4), P = .89), or revision (OR 1.9 (0.7, 4.9), P = .19) in this cohort. Multivariable analysis of any complication after SA demonstrated that renal disease was not an independent risk factor for overall complication risk in this cohort (OR 1.1 (0.7, 1.8) P = .650). ConclusionSurgeons can be assured that patients who have CKD achieve similar gains in clinical outcomes as other patients. Despite experiencing a higher risk for transfusion and intraoperative fracture, renal disease was not an independent risk factor for complications after SA in this small cohort.

The Long-Term Efficacy of Computed Tomography-Navigated Total Hip Arthroplasty: An 18-Year Follow-Up Study.

We retrospectively reviewed 145 consecutive CT-navigated THAs for >15 years. We surveyed the angles placed in both the acetabular and femoral components, survivorship, the occurrence of dislocation, the revision rate, and the fixation grade of the acetabular component. The mean follow-up duration was 18.4 years. Overall, 73.8% of THAs were within the safe zone of Lewinnek. There were four dislocations (2.8%), with three occurring within 1 month after surgery and the other within 7 years after surgery. Revision THA was performed in one case (0.69%); consequently, the survival rate was 99.3%. The fixation grade was evaluated in 144 hips, and those were evaluated as having "no loosening". CT-navigated THA was speculated to contribute to long-term survivorship, with a low rate of loosening, even after 18 years of follow-up. It was speculated that the acetabular component was placed at an acceptable insertion angle and a suitable position for stable initial fixation.

Comparison of cement-augmented pedicle screw and conventional pedicle screw for the treatment of lumbar degenerative patients with osteoporosis.

A retrospective cohort study. To compare the safety and clinical efficacy between using cement-augmented pedicle screws (CAPS) and conventional pedicle screws (CPS) for the treatment of lumbar degenerative patients with osteoporosis. Management of lumbar degenerative patients with osteoporosis undergoing spine surgery is challenging. The clinical efficacy and potential complications of the mid-term performance of the CAPS technique in the treatment of lumbar degenerative patients with osteoporosis remain to be evaluated. The data of 131 lumbar degenerative patients with osteoporosis who were treated with screw fixation from May 2016 to December 2019 were retrospectively analyzed in this study. The patients were divided into the following two groups according to the type of screw used: (I) the CAPS group (n = 85); and (II) the CPS group (n = 46). Relevant data were compared between two groups, including the demographics data, clinical results and complications. The difference in the VAS, ODI and JOA scores at three and 6months after the operation between the two groups was statistically significant (P < 0.05). At 12months after surgery and the final follow-up, a significant difference in the fusion rate was found between the two groups (P < 0.05). Four cemented screws loosening were observed in the CAPS group (loosening rate 4/384, 1.04%) and 15 screws loosening were observed in the CPS group (loosening rate 15/214, 7.01%). In the CAPS group, a total of 384 augmented screws were used, and cement leakage was observed in 25 screws (25/384, 6.51%), but no obvious clinical symptoms or serious complications were observed. Adjacent vertebral fractures occurred in six patients in the CAPS group and one in the CPS group. CAPS technique is an effective strategy for the treatment of lumbar degenerative patients with osteoporosis, with a higher fusion rate and lower screw loosening rate than CPS.

Reverse shoulder arthroplasty megaprosthesis for surgical management of severe proximal humeral bone loss

IntroductionShoulder arthroplasty in the setting of severe proximal humerus bone loss can be challenging. The purpose of this study was to evaluate the outcomes of a modular segmental megaprosthesis when implanted in a reverse configuration for complex primary arthroplasty, reconstruction at the time of oncologic resection, and revision shoulder arthroplasty. Materials and MethodsA Joint Registry Database was queried to identify all shoulder arthroplasties performed at a single institution using the Comprehensive Segmental Revision System® reverse shoulder arthroplasty (SRS-RSA, Zimmer Biomet, Warsaw, IN, USA). A retrospective review of electronic medical records and radiographs was performed to record demographic data, indication, outcomes, complications, and revision surgery. ResultsBetween February 2012 and October 2022, 76 consecutive SRS-RSA were implanted. An analysis of patients with minimum 12-month follow-up yielded 53 patients with a mean follow-up of 4.1 ± 2.43 years. Surgical complication rate in this cohort was observed in 41.5% (22/53) of cases. Overall, revision rate at final follow-up was 26.4% (14/53), with a significant difference between the primary and revision cohorts. The number of prior surgeries was a significant risk factor for revision surgery, with a hazard ratio of 1.789 (p<.001 95%CI [1.314-2.436]). When analyzing aseptic humeral loosening rates across study cohorts, a significant difference was found between the primary arthroplasty (0%, n = 0) and the revision arthroplasty cohorts (22.2%, n = 6) (p = 0.04). DiscussionReverse shoulder arthroplasty using a modular segmental megaprosthesis remains a reasonable salvage option for shoulder reconstruction in the setting of proximal humeral bone loss. Due to the substantial bone loss and soft tissue deficiencies typically present in these cases, surgeons should educate patients on the relatively high complication rate, particularly when used in the setting of a previous failed arthroplasty.

Is preoperative 3D planning reliable for predicting postoperative clinical differences in range of motion between two stem designs in reverse shoulder arthroplasty

Primary gleno-humeral osteoarthritis is associated with both excessive posterior humeral subluxation (PHS) and excessive glenoid retroversion in 40% of cases. These morphometric abnormalities are a particular issue since they may be responsible for a deterioration in long term clinical and radiological outcomes. The aim of this study was to perform a CT-analysis of patients who underwent Total Shoulder Arthroplasty (TSA) for primary osteoarthritis (OA) with B2-, B3- or C-type glenoids in whom an attempt was made to correct for excessive glenoid retroversion and excessive posterior humeral subluxation intraoperatively. We performed a retrospective, single-center study including 62 TSA patients with a pre-operative PHS of the glenohumeral joint (31 men, 31 women, 70±9 years) between January 2000 and January 2014. Glenoids were classified as B2 (32 cases), B3 (13 cases) or C (17 cases). Glenoid retroversion was corrected by anterior asymmetric reaming. Patients were reviewed for clinical and CT-scan assessment with a mean follow-up of 8.3 years (minimum 5 years). At final follow-up the CT-images were reconstructed in a scapular plan. A PHS index of >65% defined persistence. The revision free rate was estimated at 93%. Correlation between PHS and retroversion was moderate preoperatively (ρ=0.58) and strong at final follow-up (ρ=0.73). Postoperative CT-scans on average showed a surgical correction of PHS compared to preoperatively (79% vs 65% respectively, p<0.05) and retroversion (20° vs 10° respectively, p<0.05). At final follow-up, 25/62 patients had a persistence in 2D model and 41/62 in 2D corrected model. Persistence of PHS had no influence on clinical outcomes but did demonstrate a significantly higher glenoid loosening rate (20% vs 59%, p<0.05). Correlation between PHS and retroversion was moderate preoperatively and strengthened at long-term follow up. Anterior asymmetric reaming allowed for a surgical improvement of both PHS and retroversion, but it was not sufficient to maintain a correction over time. Glenoid loosening was more frequent in case of PHS persistence but seemingly without clinical relevance.

Cemented vs. press-fit humeral stems: a matched cohort analysis at a mean follow-up of 10 years

IntroductionWhile cementation of humeral stems has long been considered the gold standard for anatomic shoulder arthroplasty (aTSA), cementless, or press-fit, fixation offers a relatively cheaper and less demanding alternative, particularly in the setting of a revision procedure. However, this approach has been accompanied by concerns of implant loosening and high rates of radiolucency. In the present study we performed a propensity matched comparison of clinical and patient-reported outcomes between cemented and cementless fixation techniques for aTSA. MethodsThis study was a retrospective comparison of 50 shoulders undergoing aTSA: 25 using cemented humeral fixation versus 25 using press-fit humeral fixation. Patients in the two groups were propensity matched according to age, sex, and preoperative ASES score. Primary outcome measures included range of motion (ROM) (forward elevation, external rotation, internal rotation), patient reported outcomes (American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test (SST), Visual Analog Scores (VAS)), and implant survival. ResultsAt baseline, the two fixation groups were similar in regard to age, sex, BMI, preoperative ASES score, and surgical indication. Mean follow-up was 11.7 ± 4.95 years in the cemented cohort and 9.13 ± 3.77 years in the press-fit cohort (p=0.045). Both groups demonstrated significant improvements postoperatively in all included ROM and patient-reported outcomes. However, press-fit patients reported significantly better VAS, ASES, and SST scores. Mean VAS pain score was 1.1 ± 1.8 in press-fit patients and 3.2 ± 3.0 in cemented patients (p=0.005). The mean ASES score was 87.7 ± 12.4 in press-fit patients and 69.5 ± 22.7 in cemented patients (p=0.002). Lastly, the mean SST score was 9.8 ± 3.1 in press-fit patients and 7.7 ± 3.7 in cemented patients (p=0.040). Both fixation techniques provided lasting implant survivorship with only a single revision operation in each of the cohorts. ConclusionHerein, we provide a propensity matched, long-term comparison of patients receiving anatomic shoulder arthroplasty stratified according to humeral stem fixation technique. The results of this analysis illustrate that both types of humeral fixation techniques yield durable and significant improvements in shoulder function with similar rates of survival at 10 years of follow-up.

Larger stem to bone diameter ratio predicts lower cemented endoprosthesis failure.

With continued advances in treatment options, patients with endoprosthetic reconstruction are living longer and consequently relying upon their devices for a longer duration. Major causes of endoprosthesis failure include aseptic loosening and mechanical failure. In the setting of tumor resection, loss of bone stock and use of radiation therapy increase the risk for these complications. As such, considerations of remaining native bone and stem length and diameter may be increasingly important. We asked the following questions: (1) What was the overall rate of endoprosthesis failure at a minimum of 5-year follow-up? (2) Does resection length increase implant failure rates? (3) Does implant size and its ratio to cortical width of bone alter implant failure rates? We retrospectively analyzed patient outcomes at a single institution between the years of 1999-2022 who underwent cemented endoprosthetic reconstruction at the hip or knee and identified 150 patients. Of these 150, 55had a follow-up of greater than 5 years and were used for analysis. Radiographs of these patients at time of surgery were assessed and measured for resection length, bone diameter, stem diameter, and remaining bone length. Resection percentage, and stem to bone diameter ratios were then calculated and their relationship to endoprosthesis failure were analyzed. Patients in this cohort had a mean age of 55.8, and mean follow-up of 59.96 months. There were 78 distal femoral replacements (52%), 16 proximal femoral replacements (10.7%), and 56 proximal tibial replacements (37.3%). There were five patients who experienced aseptic loosening and six patients who experienced mechanical failure. Patients with implant failure had a smaller mean stem to bone diameter (36% vs. 44%; p = 0.002). A stem to bone diameter of 40% appeared to be a breaking point between success and failure in this series, with 90% of patients with implant failure having a stem: bone ratio less than 40%. Stem to bone ratio less than 40% increased risk for failure versus stems that were at least 40% the diameter of bone (6/19 [31.6%] vs. 0/36 [0%]; odds ratio 0.68; p < 0.001). Resection length did not appear to have an impact on the rates of aseptic loosening and mechanical failure in this series. Data from this series suggests a benefit to using stems with a larger diameter when implanting cemented endoprostheses at the hip or knee. Stems which were less than 40% the diameter of bone were substantially more likely to undergo implant failure.

DUAL-MOBILITY ARTICULATION CONFERS LOWER DISLOCATION AND REVISION RATES: A STUDY USING REVIEW OF REVIEWS METHODOLOGY

Dislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty.Understand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence.Medline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision.564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6-8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p &lt; 0.00001), total lower rate of cup revision (p &lt; 0.00001, higher incidence of fracture (p&gt;0.05).DM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs.

Aseptic loosening of the option stemmed tibial tray in the Zimmer NexGen LPS total knee arthroplasty system

BackgroundWe investigated the relationship between the backside deformation of polyethylene (PE) tibial inserts and aseptic loosening of the Option stemmed tibial tray used with Zimmer NexGen posterior-stabilised (PS) devices. We hypothesized that explanted inserts used in PS designs would exhibit greater extents of PE backside deformation than those used in equivalent cruciate retaining (CR) designs and that PE inserts retrieved from total knee arthroplasties (TKAs) revised for aseptic tibial tray loosening would exhibit greater extents of backside deformation than TKAs revised for other reasons. MethodsA total of 73 explanted fixed-bearing TKAs (42 CR and 31 PS) were examined. PE components underwent geometric examination with a coordinate measuring machine using validated techniques. Multiple regression modelling was used to identify variables associated with revision secondary to aseptic loosing and to determine factors associated with increased PE backside deformation. ResultsPE inserts retrieved from TKAs with aseptic loosening had significantly greater backside deformation than those retrieved from TKAs revised for other reasons (p < 0.001). Greater PE backside deformation was significantly associated with larger tray/insert clearance heights (p < 0.001), thinner inserts (p < 0.001) and PS TKAs (p = 0.001). ConclusionPE backside deformation was significantly greater in the PS TKAs. This may provide one explanation for the increased rate of aseptic loosening reported with the Option tibial tray used with the Legacy Posterior Stabilised (LPS) system.

Effect of sand coating on durability and micro-structural deterioration of GFRP rebar under alkaline environment attack

The objective of this study is to investigate the consequences of the sand-coated layer on the durability of glass fiber reinforced polymer (GFRP) rebars under four alkali solution concentrations and three temperatures. A total of 464 GFRP rebars specimens were manufactured to undergo accelerated corrosion experiments and mechanical performance test. Among them, 438 specimens were used to test the residual tensile strength of GFRP rebars after 120 days of immersion; 26 specimens were applied for surface observation and microscopic testing to analyze the degradation and damage process of GFRP rebars. SEM and digital camera were used to examine the micro-structure of samples either with or without sand layer covering. The unidirectional tensile strength experiment was conducted to test the remaining tensile strength of GFRP rebars after corrosion. The experimental results indicate that sand coating provides better protection and restraint in GFRP rebar durability reduction, resulting in a lower rate of fiber loosening and resin cracking and flaking when exposed to a solution over a pH of 12.5. As the failure of GFRP rebars ranges from local damage to cracking of the peripheral sand protective layer, the pH value of 12.5 is considered a critical alkali solution concentration. Based on experimental results, an improved model was proposed to predict the short-term and long-term residual strength values of GFRP rebars. The calculation results indicate that the predict values are in good agreement with the experimental ones, and the proposed model can be used to predict the residual strength of GFRP rebars.

Cemented femoral stem design and postoperative periprosthetic fracture risk following total hip arthroplasty.

Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF.