Risk factors and modes of failure in the modern dual mobility implant. A systematic review and meta-analysis.

BACKGROUND: The aims of this meta-analysis were to: (1) validate the outcome of modern dual mobility (DM) designs in patients who had undergone primary and revision total hip arthroplasty (THA) procedures and (2) to identify factors that affect the outcome. METHODS: We searched for studies that assessed the outcome of modern DM-THA in primary and revision procedures that were conducted between January, 2000 to August, 2020 on PubMed, MEDLINE, Cochrane Reviews and Embase. The pooled incidence of the most common failure modes and patient reported outcomes were evaluated in patients who have received: (1) primary THA, (2) revision THA for all causes or (3) for recurrent dislocation. A meta-regression analysis was performed for each parameter to determine the association with the outcome. The study design of each study was assessed for potential bias and flaws by using the quality assessment tool for case series studies. RESULTS: A total of 119 studies (N= 30016 DM-THAs) were included for analysis. The mean follow-up duration was 47.3 months. The overall implant failure rate was 4.2% (primary: 2.3%, revision for all causes: 5.5%, recurrent dislocation: 6.0%). The most common failure modes were aseptic loosening (primary: 0.9%, revision for all causes: 2.2%, recurrent dislocation: 2.4%), septic loosening (primary:0.8%, revision for all causes: 2.3%, recurrent dislocation: 2.5%), extra-articular dislocation (primary:0.6%, revision for all causes:1.3%, recurrent dislocation:2.5%), intra-prosthetic dislocation (primary:0.8%, revision for all causes:1.0%, recurrent dislocation:1.6%) and periprosthetic fracture (primary:0.9%, revision for all causes:0.9%, recurrent dislocation:1.3%). The multi-regression analysis identified younger age (ß=-0.04, 95% CI -0.07 - -0.02) and female patients (ß=3.34, 95% CI 0.91-5.78) were correlated with higher implant failure rate. Age, gender, posterolateral approach and body mass index (BMI) were not risk factors for extra-articular or intra-prosthetic dislocation in this cohort. The overall Harris hip score and Merle d'Aubigné score were 84.87 and 16.36, respectively. Level of evidence of this meta-analysis was IV. CONCLUSION: Modern dual-mobility designs provide satisfactory mid-term implant survival and clinical performance. Younger age and female patients might impact the outcome after DM-THA. Future research directions should focus on, (1) long-term outcome of modern dual-mobility design, including specific concerns such as intra-prosthetic dislocation and elevated metal ion, and (2) cost-effectiveness analysis of dual-mobility implant as an alternative to conventional THA for patients who are at high risk of dislocation.

Risk factors of synchronous multifocal necrotizing fasciitis: a case control study in comparison with monofocal necrotizing fasciitis in Taiwan.

BACKGROUND: Monofocal necrotizing fasciitis (MONF) involves a single site in a rapidly progressing infection and necrosis of the fascia and surrounding soft tissue. Synchronous multifocal necrotizing fasciitis (SMNF), the simultaneous development of NF in multiple noncontiguous sites, is rarely reported. This study aimed to compare the clinical characteristics and outcomes between patients with SMNF and MONF, and to determine the risk factors of SMNF. METHODS: Our retrospective case-control study compared the clinical characteristics and outcomes, between January 2006 and January 2013, of patients with SMNF and of patients with MONF of the extremities. RESULTS: We enrolled 144 patients with NF of the extremities: 19 with SMNF and 125 with MONF. The duration of symptoms before admission was significantly shorter for the former than for the latter (1.7 days vs. 3.3 days, p = 0.001); the prevalence of shock at the initial visit significantly higher (73.7% vs. 36%, p = 0.002); and the total-case postoperative mortality rate significantly higher (68.4% vs. 14.4%, p <  0.001). In further analysis of the total-case mortality, 9 in 13 SMNF deaths (69.2%) within 7 days after fasciotomy were in the majority while 13 with 28-day mortality (72.2%) was the majority of MONF deaths (p <  0.001). SMNF was significantly more likely to involve bacteremia (89.5% vs. 36%, p <  0.001). Independent risk factors for SMNF were liver cirrhosis (LC) (odds ratio [OR] 6.0, p = 0.001) and end-stage renal disease (ESRD) (OR 7.1, p = 0.035). Gram-negative bacteria were most common in SMNF, and Gram-positive bacteria in MONF (83.3% vs. 53.3%, p = 0.005). Vibrio species were the most common single microbial cause (35.4%) of all NF patients and were the overwhelming cause (73.7%) of SMNF. Staphylococcus aureus and group A ß-hemolytic streptococcus (45.6%) were the other predominant causes of MONF while both (10.5%) rarely caused multifocal NF. CONCLUSIONS: SMNF was more fulminant than was MONF. SMNF was attributable primarily to marine Gram-negative bacteria. Physicians should be aware of SMNF because of its extremely high mortality rate.

Hyperglycemia inhibits osteoblastogenesis of rat bone marrow stromal cells via activation of the Notch2 signaling pathway.

Background: Bone fragility and related fractures are increasingly being recognized as an important diabetic complication. Mesenchymal progenitors often serve as an important source of bone formation and regeneration. In the present study, we have evaluated the effects of diabetes on osteoblastogenesis of mesenchymal progenitors. Methods: Primary bone marrow stromal cells (BMSCs) were isolated from control and streptozotocin-induced diabetic rats. These cells were evaluated for the effects of in vivo hyperglycemia on the survival and function of mesenchymal progenitors. We concomitantly investigated the effects of different concentrations of glucose, osmolality, and advanced glycation end product (AGE) on osteogenic differentiation and matrix mineralization of rat bone marrow mesenchymal stem cells (RMSC-bm). The relationship between the expression levels of Notch proteins and the corresponding ALP levels was also examined. Results: Our results revealed that in vivo hyperglycemia increased cell proliferation rate but decreased osteogenic differentiation and matrix mineralization of primary rat BMSCs. In vitro high glucose treatment, instead of high AGE treatment, induced a dose-dependent inhibition of osteoblastogenesis of RMSC-bm cells. Activation of the Notch2 signaling pathway, instead of the Notch1 or osmotic response pathways, was associated with these diabetic effects on osteoblastogenesis of mesenchymal progenitors. Conclusions: Hyperglycemia might inhibit osteoblastogenesis of mesenchymal progenitors via activation of the Notch2 signaling pathway.

Zoledronate induces cell cycle arrest and differentiation by upregulating p21 in mouse MC3T3-E1 preosteoblasts.

Background: Increasing research has recently been focused on the supplementary use of drugs such as bisphosphonates that are known to influence bone turnover to prevent and treat periprosthetic bone loss and subsequent implant loosening following total joint replacements. However, there are still concerns about the conflicting effects of bisphosphonate treatment on osteoblastic bone formation in the literature. Methods: In this study, we investigate the role of zoledronate (ZOL) in regulating cell cycle distribution and differentiation in mouse MC3T3-E1 preosteoblasts and also explore the mechanism underlying this effect of ZOL. We examined the expression levels of osteocalcin (OCN) by quantitative polymerase chain reaction (qPCR), the total amount of CDK6, p21 and p27 proteins by Western blot analysis, and the cell cycle distribution by flow cytometric analysis in mouse MC3T3-E1 preosteoblasts to evaluate the effect of ZOL. Small interfering RNAs (siRNAs) were used to assess the individual contributions of genes to specific osteoblast phenotypes. Results: In addition to increased OCN expression, we found that ZOL treatment induces the G0/G1 arrest and results in the increase of p21 and p27 expressions and decrease of CDK6 expression in mouse MC3T3-E1 preosteoblasts. Both p21 and p27 mediates ZOL-induced cell cycle exit; however, p21, but not p27, is responsible for the increase of ZOL-induced OCN expression in these cells. Conclusions: These results endorse that ZOL might have an anabolic effect on osteoblasts. The CDK inhibitor p21 plays a key role in regulating osteoblast differentiation by controlling proliferation-related events in mouse MC3T3-E1 preosteoblasts.

Treatment of displaced transverse fractures of the patella: modified tension band wiring technique with or without augmented circumferential cerclage wire fixation.

BACKGROUND: Displaced transverse fractures of the body of the patella are usually associated with disruption of extensor mechanism and should be fixed surgically. The most common method is a tension band wiring (TBW) technique. Some surgeons concurrently employ an augmented circumferential cerclage wiring (ACCW) technique to help fracture stabilization and aid in fracture healing; however, its role and effect on the treatment outcomes is unclear. METHODS: We performed a STROBE-compliant retrospective observational cohort study on all cases of acute closed patella fracture that were treated at our institution between 2006 and 2012. Of 185 episodes, 72 (38.9%) were eligible for this study according to our inclusion/exclusion criteria. We classified these subjects with AO/OTA type 34-C1.1 or 34-C2 lesions into two groups for analyses: fractures treated with modified TBW and ACCW (group 1, n = 27) and those treated with modified TBW alone (group 2, n = 45). Plain radiographs were used to evaluate radiographic outcomes and the effect of potential risk factors on fixation failure was analyzed by subgroup comparisons. RESULTS: Our results revealed that there were no significant differences in the rates of fixation failure (P = 0.620), nonunion (P = 0.620), and revision surgery (P = 0.620) between the groups. Although not statistically significant, there was a trend towards a positive risk association between fixation failure and age distribution > 60 years (10.0% vs. 0.0%, P = 0.124; OR = 8.0, P = 0.168) and > 70 years (9.4% vs. 2.5%, P = 0.321; OR = 4.0, P = 0.237) and the superficial level of the K-wires (12.0% vs. 1.5%, P = 0.117; OR = 6.3, P = 0.121). Regarding those modified TBW patients concurrently treated with an ACCW, the potential risk association between fixation failure and the superficial level of the K-wire was prone to increase further (28.6% vs. 0.0%, P = 0.060; OR = 18.6, P = 0.071). CONCLUSIONS: Concurrent application of an ACCW might be needless and not efficacious to help fracture stabilization and healing in patients having been treated with modified TBW for displaced transverse fractures of the body of the patella. Adherence to correct surgical technique such as putting the K-wires at the proper level and securing control of the both ends of the K-wires may be more important and help in improving outcomes.

The outcome of surgical management of proximal humeral fractures using locking plates: comparison between locking plates with different geometry.

BACKGROUND: Locking plate fixation appears to be a standard treatment for proximal humeral fracture. Different locking plate designs might result in different radiographic and functional outcomes. The original version of the Proximal Humeral Internal Locking System (PHILOS; DePuy Synthes, Warsaw, IN, USA) occupied the largest volume of the humeral head by screw distribution, whereas the Zimmer Periarticular Locking Plate (ZPLP) system (Zimmer Biomet, Warsaw, IN, USA) occupied the smallest. METHODS: We enrolled 50 patients undergoing ZPLP treatment and 50 undergoing PHILOS treatment. RESULTS: The postoperative amount of impaction was significantly higher using the ZPLP System than using the PHILOS. Subgroup analysis showed that medial calcar support was another critical factor that affected surgical outcomes, especially when using the ZPLP System. CONCLUSION: The amount of postoperative impaction was significantly higher when the ZPLP was used compared with the PHILOS locking plate. Medial calcar support is another critical factor that affects surgical outcomes. However, no significant differences in functional outcomes (Constant-Murley score) between the ZPLP System and the PHILOS were noted at the 12-month follow-up.

Bone turnover and periprosthetic bone loss after cementless total hip arthroplasty can be restored by zoledronic acid: a prospective, randomized, open-label, controlled trial.

BACKGROUND: Although the loss of bone mineral density (BMD) after total hip arthroplasty (THA) is a known problem, it remains unresolved. This study prospectively examined the effect of zoledronic acid (ZA) on bone turnover and BMD after cementless THA. METHODS: Between January 2010 and August 2011, 60 patients who underwent cementless THA were randomly assigned to receive either ZA infusion or placebo (0.9% normal saline only) postoperatively. ZA was administered at 2 day and 1 year postoperatively. Periprosthetic BMD in seven Gruen zones was assessed preoperatively and at given time points for 2 years. Serum markers of bone turnover, functional scales, and adverse events were recorded. RESULTS: Each group contained 27 patients for the final analysis. The loss of BMD across all Gruen zones (significantly in zones 1 and 7) up to 2 years postoperatively was noted in the placebo group. BMD was significantly higher in the ZA group than in the placebo group in Gruen zones 1, 2, 6, and 7 at 1 year and in Gruen zones 1, 6, and 7 at 2 years (p < 0.05). Compared with baseline measures of BMD, the ZA group had increased BMD in zones 1, 2, 4, 5, 6, and 7 at 1 year and in zones 1, 4, 6, and 7 at 2 years (p < 0.05). Serum bone-specific alkaline phosphatase and N-telopeptide of procollagen I levels were significantly increased at 6 weeks in the placebo group and decreased after 3 months in the ZA group. A transient decrease in osteocalcin level was found at 6 months in the ZA group. Functional scales and adverse events were not different between the two groups. CONCLUSIONS: The loss of periprosthetic BMD, especially in the proximal femur (zones 1 and 7), after cementless THA could be effectively reverted using ZA. In addition, bone turnover markers were suppressed until 2 years postoperatively following ZA administration. TRIAL REGISTRATION: Chang Gung Memorial Hospital Protocol Record 98-1150A3, Prevention of Periprosthetic Bone Loss After Total Hip Replacement by Annual Bisphosphonate Therapy, has been reviewed and will be made public on ClinicalTrials.gov. TRIAL REGISTRATION NUMBER: NCT02838121 . Registered on 19 July, 2016.

Synchronous multifocal necrotizing fasciitis prognostic factors: a retrospective case series study in a single center.

PURPOSE: No reports have been published on synchronous multifocal necrotizing fasciitis (SMNF), a multifocal presence of necrotizing fasciitis in different extremities. We evaluated the clinical characteristics and outcomes of SMNF. METHODS: Eighteen patients (14 men, 4 women; mean age: 59 years) diagnosed with SMNF of the extremities between January 2004 to December 2012 were enrolled and evaluated. RESULTS: Vibrio species were the most commonly (78%; n = 14) isolated; others were two cases (11%) of Aeromonas spp., one case (6%) of group A ß-hemolytic streptococcus, and one case of coagulase-negative staphylococcus. SMNF was in the bilateral lower limbs (72%; n = 13), bilateral upper limbs (17%; n = 3), and one patient with one upper and one lower limb (11%). Non-surviving patients had more bilateral lower limb involvement and thrombocytopenia. CONCLUSIONS: Most patients with SMNF were male and had bilateral lower limb and marine Gram-negative bacteria involvement. The mortality of SMNF remained extremely high in patients with involvement of bilateral lower limb and initial thrombocytopenia.

Non-steroidal anti-inflammatory drugs and the risk of a second hip fracture: a propensity-score matching study.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed for elderly patients, particularly after a hip fracture. However, we are not clear about the effect of NSAIDs on the risk of a second hip fracture because of confounding factors. METHODS: This was a Taiwan National Health Insurance Research Database-based study using propensity-score matching (PSM) to control for confounding. Enrollees were selected from patients with a hip fracture during 1996-2004 and followed longitudinally until December 2009. After PSM for comorbidities and bisphosphonate therapy, 94 patients with a second hip fracture were assigned to the Cases group and 461 without it to the Controls group. The target drugs are NSAIDs; paracetamol and dexamethasone are used for comparison. RESULTS: The correlation between the mean daily-dose (MDD) ratios of NSAIDs and the probability values of the current statistical tests were highly negative (Pearson's r = -0.920, P = 0.003), which indicated that the higher the MDD ratios, the greater the risks of a second hip fracture. A Kaplan-Meier survival analysis showed a time-dependent trend of increasing risk of a second hip fracture in patients taking NSAIDs (P < 0.001). Moreover, patients ≥ 60 years old had a higher risk of a second hip fracture than did those <60 and taking the NSAIDs diclofenac (P = 0.016) and celecoxib (P = 0.003) and the corticosteroid dexamethasone (P = 0.018), but not those taking analgesic paracetamol (P = 0.074). CONCLUSIONS: We conclude that taking NSAIDs after a fragility hip fracture dose- and time-dependently significantly increases the risk of a second hip fracture, especially in elderly patients. To lower the risk of a second hip fracture, any underlying causes for excessively using NSAIDs should be treated and thus fewer NSAIDs prescribed after a first hip fracture.

Effects of teriparatide on cementless bipolar hemiarthroplasty in patients with osteoporotic femoral neck fractures.

BACKGROUND: For osteoporotic femoral neck fractures, suitable bone-implant stability is critical for pain relief, early return to daily activities and reduction of complications. Teriparatide (parathyroid hormone [PTH1-34]) can improve bone-implant stability in some basic studies. However it's use in osteoporotic femoral neck fractures treated by cementless hemiarthroplasties for the beneficial effects on bone-implant stability is sparse in the literature. The aim of this study was to determine if post-operative teriparatide administration can reduce femoral stem migration and improve early functional recovery and health-related quality of life (HRQoL). METHODS: Between 2010 and 2014, patients with osteoporotic femoral neck fracture who underwent cementless bipolar hemiarthroplasty were included into this retrospective cohort study. Group A included patients treated with cementless bipolar hemiarthroplasty only; Group B patients had additional teriparatide. Demographic data, complications, radiographic and functional outcomes as well as health-related quality of life (HRQoL) were compared. RESULTS: There were 52 hips in group A (no teriparatide) and 40 hips in group B (patient who received teriparatide). The subsidence of the femoral stem tended to be significantly decreased in the teriparatide group at 6 and 12 weeks post-operatively (p = 0.003 and p = 0.008, respectively). The Harris Hip Score (HHS) increased significantly from pre-operation to 6 weeks post-operatively and thereafter up to one year in both groups. However, there were no significant differences in terms of subsequent fracture, mortality, HHS, and HRQoL between two groups during the entire study period. CONCLUSIONS: Teriparatide significantly reduces the subsidence of the cementless femoral stem in elderly patients in the early post-operative period, but this benefit does not reflect better functional outcomes and HRQoL. Further prospective randomized large-scale cohort study is warranted for evidence-based recommendations.

Outcomes and second-look arthroscopic evaluation after combined arthroscopic treatment of tibial plateau and tibial eminence avulsion fractures: a 5-year minimal follow-up.

BACKGROUND: Tibial eminence avulsion fracture often co-occurs with tibial plateau fracture, which leads to difficult concomitant management. The value of simultaneous arthroscopy-assisted treatment continues to be debated despite its theoretical advantages. We describe a simple arthroscopic suture fixation technique and hypothesize that simultaneous treatment is beneficial. METHODS: Patients with a tibial eminence avulsion fracture and a concurrent tibial plateau fracture who underwent simultaneous arthroscopically assisted treatment between 2005 and 2008 were enrolled in this retrospective study. Second-look arthroscopic evaluation and Rasmussen scores of clinical and radiographic parameters were used to assess simultaneous treatment. RESULTS: Forty-one patients (41 knees) met the inclusion criteria. All 41 fractures were successfully united. All patients had side-to-side differences of less than 3 mm and negative findings in Lachman and pivot-shift tests at their final follow-up. The mean postoperative Rasmussen clinical score was 27.3 (range: 19-30), and the mean radiologic score was 16.5 (range: 12-18). Clinical and radiographic outcomes in 98 % of the patients were good or excellent. There were no complications directly associated with arthroscopy in any patient. CONCLUSIONS: Simultaneous arthroscopic suture fixation of associated tibial eminence avulsion fracture did not interfere with the plates and screws used to stabilize the tibial plateau fracture. It gave the knee joint adequate stability, minimal surgical morbidity, and satisfactory radiographic and clinical outcomes in a minimum follow-up of 5 years and in the arthroscopic second-look assessments.

The Influence of Alignment on Midterm Outcome after Total Knee Arthroplasty in Patients With Marked Coronal Femoral Bowing.

Whether the mechanical axis should be restored to neutral remains controversial when the patient has marked coronal femoral bowing. Eighty-four total knee arthroplasties were retrospectively reviewed. In the neutral-aligned group A the immediate postoperative mechanical axis of 179 ± 1° held stable (P = 0.841). The postoperative mechanical axis decreased from 176 ± 1° to 173 ± 1° (P = 0.024) in the outlier group. Progressive varus in the outlier group at follow-up was probably due implant instability and ligament imbalance as well as excessive polyethylene wear. At a mean follow-up of 75.8 months, no statistically significant difference was detected between the two groups. Long-term follow up will be needed to determine if the maintenance in radiographic results translates to better clinical outcomes.

Comparison of computer-navigated and conventional total knee arthroplasty in patients with Ranawat type-II valgus deformity: medium-term clinical and radiological results.

BACKGROUND: Arthritic knees with Ranawat type-II valgus deformity present with soft tissue contracture and osseous anomalies that make total knee arthroplasty (TKA) difficult. We hypothesized that computer-navigated-TKA (CN-TKA) may be superior to conventional techniques and provide better mid-term radiographic and clinical outcomes in such cases. METHODS: Between January 2002 and January 2009, patients with Ranawat type-II valgus deformity who underwent primary TKA were entered into this retrospective study. Conventional TKA and CN-TKA were compared for the accuracy of component placement, joint line level, and postoperative limb alignment. International Knee Society scores and patellar scores were used for clinical assessment. RESULTS: A total of 62 patients (70 knees) with a minimum of 5 years of follow-up were studied. Conventional TKA was performed in 36 knees and CN-TKA in 34 knees. A significantly higher rate of lateral retinaculum release was recorded in the conventional TKA group compared to the CN-TKA group. Proper restoration of joint line was achieved using CN-TKA. The range of motion of the knees was similar in both groups preoperative and postoperatively. There were no significant differences in reconstructed mechanical axes, accuracy of component positioning, and difference in perioperative hemoglobin level between the two groups. At a mean follow-up of 6.2 years, both groups had significant postoperative improvements in clinical performance, however the difference did not reach statistical significance between both techniques. CONCLUSIONS: Our findings demonstrate that CN-TKA can properly restored the joint line level for arthritic knees with Ranawat type II valgus deformity. However, no differences in clinical function, limb and component alignment, or survival of the prostheses were noted between the CN-TKA and conventional TKA groups at a mean follow-up of 6.2 years.

Differences in component and limb alignment between computer-assisted and conventional surgery total knee arthroplasty.

PURPOSE: Marked coronal femoral bowing may bear a risk for mal-alignment of femoral component and reconstructed mechanical axis (MA) by using conventional instrumentations. The aim of this study was to investigate the usefulness of computer-assisted surgery-total knee arthroplasty (CAS-TKA) under this circumstance. METHODS: We retrospectively analyzed patients with osteoarthritic knee and marked coronal femoral bowing who underwent TKA at our institution. The CAS-TKA and the conventional techniques were compared by radiographic parameters in coronal and sagittal planes, and rotational alignment of femoral component was assessed by computed tomography (CT) scans. The Hospital for Special Surgery (HSS) and International Knee Society (IKS) scores were obtained for all patients preoperatively and at the last follow-up. RESULTS: A total of 65 knees were enrolled in this study. Twenty-eight TKAs implanted using a CT-free navigation system, and the remaining 37 TKAs implanted using the conventional technique. CAS-TKAs were more consistent than conventional TKAs in aiding proper postoperative MA and ideal alignments of femoral component in the coronal and sagittal planes. However, CAS-TKA group was not obtained at significantly higher rates of femoral component in axial plane. At a mean follow-up of 43 months, there was no significant difference in HSS and IKS scores between the groups. CONCLUSIONS: Although CAS-TKA did not have superior functional outcomes in the short-term follow-up, proper coronal and sagittal alignment of femoral component and postoperative MA were obtained in patients with marked coronal femoral bowing. The long-term follow-up will be needed to clarify the eventual benefits. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Computed tomography evaluation in total knee arthroplasty: computer-assisted navigation versus conventional instrumentation in patients with advanced valgus arthritic knees.

Arthritic knees with advanced valgus deformity present with soft tissue and osseous anomalies that make total knee arthroplasty (TKA) difficult. We conducted a retrospective chart review of 41 patients (51 knees) to determine whether computer-assisted surgery-TKA (CAS-TKA) is superior to TKA using conventional guiding systems. A significantly higher rate of lateral retinaculum release as well as outlier of sagittal mechanical axes and position of the femoral component (femoral flexion and femoral rotational angle) was recorded in the conventional TKA group versus the CAS-TKA group. Both groups had significant postoperative improvement in clinical performance, but results did not differ significantly between groups. Despite its radiographic benefit, CAS-TKA showed no significant benefit over TKA in short-term clinical functional outcomes when performed by an experienced surgeon.

Zoledronic Acid Ameliorates the Bone Turnover Activity and Periprosthetic Bone Preservation in Cementless Total Hip Arthroplasty.

The administration of zoledronic acid (ZA) to patients who received cementless total hip arthroplasty (THA) has been reported to reduce bone turnover markers (BTMs) and increase bone mineral density (BMD). The effects of two-dose ZA versus placebo on cementless THA patients were analyzed in this five-year extension study. Alkaline phosphatase (ALP), osteocalcin (OC), procollagen 1 intact N-terminal propeptide (P1NP), serum calcium, renal function, radiological findings, and functional outcomes were compared in 49 patients, and the periprosthetic BMD of seven Gruen zones were compared in 19 patients. All the patients had normal renal function and calcium levels at their final follow-up. The mean ALP level in the ZA group was significantly lower at the fifth year, mean OC levels were significantly lower at the second and fifth year, and mean P1NP levels were significantly lower from 6 weeks to 5 years as compared with the control group. Fifth-year BMD levels were not found to be different between the ZA and control groups. The BMD Change Ratios in the ZA group were significantly increased in Gruen zone 6 at 1, 2, and 5 years. Our study results suggest that short-term ZA treatment with a subsequent 4-year drug holiday may inhibit serum BTMs and provide periprosthetic bone preservation at five years without adverse events.

Incidence of different types of subsequent fractures and related mortality in Taiwan.

Hip fracture is the most common type of fracture to occur within 2 years after an initial fracture. Mortality risk increases when a subsequent fracture occurs. The occurrence of subsequent fracture is significantly higher in patients with hip fractures than others. Prevention of subsequent fracture is of paramount important. PURPOSE: Osteoporotic fracture significantly increases risk of subsequent fracture. In this retrospective cohort study, we used the Taiwan National Health Insurance Database (NHIRD) to analyze data on fractures in a group at high risk of osteoporosis. We aimed to distinguish differences in subsequent fracture types and their relationship with mortality. METHODS: We enrolled patients aged ≥ 50 years old who were diagnosed with an initial fracture classified as hip, vertebral, upper end of the humerus, or wrist. Data from 2 years of follow-up were analyzed. Risks of subsequent fracture events and mortality were calculated by Kaplan-Meier estimation and assessed with Cox proportional hazards models. RESULTS: We included 375,836 patients from the 2011-2015 NHIRD. Patients with initial hip fracture had the highest incidence of subsequent fracture at both 1- and 2-year follow-up (7.0% and 10.9%). Subsequent fractures occurred mainly at the hip. Conversely, other patients had a higher proportion of subsequent vertebral fracture. Patients with subsequent fracture classified as hip, vertebral, and upper end of the humerus had significantly higher cumulative mortality rates than that of patients who had no subsequent fracture, with adjusted hazard ratios of 1.64 (95% CI = 1.57-1.71, p < 0.01), 1.06 (95% CI = 1.00-1.12, p = 0.04), 1.31 (95% CI = 1.17-1.46, p < 0.01), respectively. CONCLUSION: Patients who experienced an initial hip fracture are at greatest risk of subsequent fracture, most commonly the hip. Occurrence of subsequent fractures was associated with an increased mortality risk. Thus, there is a need for early intervention following initial hip fractures.

Post-operative prophylactic antibiotics in aseptic revision hip and knee arthroplasty: a propensity score matching analysis.

The use of extended antibiotic (EA) prophylaxis (> 24 h) remains controversial in aseptic revision arthroplasty. We sought to determine whether EA prophylaxis reduces the risk of periprosthetic joint infection (PJI) in aseptic revision hip and knee arthroplasty. A total of 2800 patients undergoing aseptic revision hip and knee arthroplasty at five institutional databases from 2008 to 2017 were evaluated. One to two nearest-neighbor propensity score matching analysis was conducted between patients who did and did not receive extended antibiotic prophylaxis. The matching elements included age, sex, body mass index, Charlson comorbidity index, hospital distribution, year of surgery, joint (hip or knee), surgical time, CRP, preoperative hemoglobin, albumin, and length of stay. The primary outcome was the development of PJI, which was assessed at 30 days, 90 days, and 1 year following revision and analyzed separately. A total of 2467 (88%) patients received EA prophylaxis, and 333 (12%) patients received standard antibiotic (SA) prophylaxis (≤ 24 h). In the propensity-matched analysis, there was no difference between patients who received EA prophylaxis and those who did not in terms of 30-day PJI (0.3% vs. 0.3%, p = 1.00), 90-day PJI (1.7% vs. 2.1%, p = 0.62) and 1- year PJI (3.8% vs. 6.0%, p = 0.109). For revision hip, the incidence of PJI was 0.2% vs 0% at 30 days (p = 0.482), 1.6% vs 1.4% at 90 days (p = 0.837), and 3.4% vs 5.1% at 1 year (p = 0.305) in the EA and SA group. For revision knee, the incidence of PJI was 0.4% vs 0.9% at 30 days (p = 0.63), 1.8% vs 3.4% at 90 days (p = 0.331), and 4.4% vs 7.8% at 1 year (p = 0.203) in the EA and SA group. A post hoc power analysis revealed an adequate sample size with a beta value of 83%. In addition, the risks of Clostridium difficile and resistant organism infection were not increased. This multi-institutional study demonstrated no difference in the rate of PJIs between patients who received extended antibiotic prophylaxis and those who did not in aseptic revision arthroplasty. The risk of C. difficile and resistant organism infection was not increased with prolonged antibiotic use.

Prognostic factors and monomicrobial necrotizing fasciitis: gram-positive versus gram-negative pathogens.

BACKGROUND: Monomicrobial necrotizing fasciitis is rapidly progressive and life-threatening. This study was undertaken to ascertain whether the clinical presentation and outcome for patients with this disease differ for those infected with a gram-positive as compared to gram-negative pathogen. METHODS: Forty-six patients with monomicrobial necrotizing fasciitis were examined retrospectively from November 2002 to January 2008. All patients received adequate broad-spectrum antibiotic therapy, aggressive resuscitation, prompt radical debridement and adjuvant hyperbaric oxygen therapy. Eleven patients were infected with a gram-positive pathogen (Group 1) and 35 patients with a gram-negative pathogen (Group 2). RESULTS: Group 2 was characterized by a higher incidence of hemorrhagic bullae and septic shock, higher APACHE II scores at 24 h post-admission, a higher rate of thrombocytopenia, and a higher prevalence of chronic liver dysfunction. Gouty arthritis was more prevalent in Group 1. For non-survivors, the incidences of chronic liver dysfunction, chronic renal failure and thrombocytopenia were higher in comparison with those for survivors. Lower level of serum albumin was also demonstrated in the non-survivors as compared to those in survivors. CONCLUSIONS: Pre-existing chronic liver dysfunction, chronic renal failure, thrombocytopenia and hypoalbuminemia, and post-operative dependence on mechanical ventilation represent poor prognostic factors in monomicrobial necrotizing fasciitis. Patients with gram-negative monobacterial necrotizing fasciitis present with more fulminant sepsis.