Acute Periprosthetic Hip Fractures With Short, Uncemented Femoral Stems.

BACKGROUND: Uncemented femoral stems in hip arthroplasty have shown excellent long-term results, and several systematic studies indicate satisfactory performance of short stems. However, biomechanical and finite element analysis studies have suggested that shorter stems allow greater micromotion, producing greater strain at the implant-bone interface, which potentially increases the risk for periprosthetic fracture (PPF). We sought to assess this risk within our unit. METHODS: Our institution's arthroplasty database was searched for all primary total hip arthroplasties using short femoral stems performed between July 14, 2009 and August 29, 2022. The overall PPF rate and the PPF rate for individual femoral stems were established. Preoperative X-rays for each case were analyzed to characterize individual proximal femoral geometry. A data analysis was performed to identify risk factors for PPF. RESULTS: For the time period assessed, 3,192 short femoral stems were implanted. This included 1,561 of stem A and 1,631 of stem B. Women constituted 55.37% of the cohort. The average patient age was 66 years (range, 22 to 95). The PPF rate was 0.6%, with 19 PPFs identified at a follow-up of 3 months. There was a significantly higher fracture rate in stem A (0.96%) compared to stem B (0.25%) (P ≤ .01). Proximal femoral geometry, age, and sex were not determined to be risk factors for PPF in our cohort. Individual surgeons and surgical approaches appeared to confer no increased risk. There was no significant difference in average stem length, but multivariate analysis identified stem type and stem length as an independent risk factor for PPF. CONCLUSIONS: Our study identified individual stem and stem length as independent risk factors for PPF within our cohort. PPF is a multifactorial issue, and consensus on emerging risk factors such as implant design will hopefully inform decisions that can provide further risk reduction for individual patients.

Cobalt ions induce a cellular senescence secretory phenotype in human synovial fibroblast-like cells that may be an early event in the development of adverse local tissue reactions to hip implants.

Objectives: Total hip arthroplasty is a successful procedure for treating advanced osteoarthritis (OA). Metal bearing surfaces remain one of the most widely implanted prosthesis, however approximately 10% of patients develop adverse local tissue reactions (ALTRs), namely lymphocytic predominant soft tissue reaction with or without necrosis and osteolysis resulting in high revision rates. The mechanism(s) for these reactions remains unclear although T lymphocyte mediated type IV hypersensitivity to cobalt (Co) and chromium (Cr) ions have been described. The purpose of this study was to determine the prolonged effects of Co and Cr metal ions on synovial fibroblasts to better understand the impact of the synovial membrane in the development of ALTRs. Methods: Human synovial fibroblast-like cells were isolated from donors undergoing arthroplasty. DNA content and Alamar blue assay were used to determine cellular viability against exposure to Co and Cr. A beta-galactosidase assay was used to determine the development of cellular senescence. Western blotting and RT-qPCR were employed to determine changes in senescent associated secretory factors, signaling and anti-oxidant enzyme expression. A fluorescent assay was used to measure accumulation of hydrogen peroxide. Results: We demonstrate that prolonged cobalt exposure results in a downregulation of the enzyme catalase resulting in cytosolic accumulation of hydrogen peroxide, decreased Akt activity and cellular senescence. Senescent fibroblasts demonstrated upregulation of proinflammatory cytokines IL-1ß and TNFα in addition to the neurotrophic factor NGF. Conclusion: Our results provide evidence that metal ions induce a senescent associated secretory phenotype in synovial fibroblasts that could contribute to the development of adverse local tissue reactions.

Similar complication and readmission rates following simultaneous versus staged bilateral total hip arthroplasty.

PURPOSE: To compare short-term complications and readmission rates, in patients treated with simultaneous versus staged bilateral total hip arthroplasty (THA) within a year from the index procedure. METHODS: We reviewed the charts of patients that underwent simultaneous and staged-within a year-bilateral THA, between 2016 and 2020. Preoperative baseline characteristics were evaluated, while differences in terms of 30-day major and 30-day minor complications and readmission rates were compared between the groups. RESULTS: One-hundred-sixty patients (mean age, 64.3 years; SD, ± 11.7) were identified. Seventy-nine patients were treated with simultaneous (Group A) and eighty-one patients with staged (Group B) THA. There were no differences in baseline characteristic between the two groups (p > 0.050). Group A was more likely to receive general anesthesia (43% vs. 9.9%, p < 0.001) and had longer total operative time (182.8 vs. 128.0 min, p < 0.001). Group A had an overall shorter total length of hospital stay (5.8 vs. 8.6 days, p < 0.001). No differences in transfusion rates (p = 0.229) and no differences in major and minor complications (p > 0.05) were identified. Postoperative visits at the emergency department or readmissions were similar between the two groups (p > 0.050). CONCLUSION: This study shows that similar complication and readmission rates are expected after simultaneous and staged THA. Simultaneous bilateral THA is a safe and effective procedure, that should be considered for patients that present with radiologic and clinical bilateral hip disease.

Outcomes of Ceramic-On-Ceramic Bearing Total Hip Arthroplasty: A Minimum 10-Year Follow-Up Study.

BACKGROUND: Although the fourth generation of ceramics has demonstrated excellent clinical results 5 to 6 years postoperatively, concerns over ceramic fracture and squeaking persist and longer-term follow-up (minimum 10 years) studies are warranted. Our study aimed to evaluate the minimum 10-year clinical outcomes and bearing-specific complications of ceramic-on-ceramic (CoC) total hip arthroplasties. METHODS: We retrospectively evaluated all patients who underwent primary delta CoC total hip arthroplasty in our institution between January 2004 and February 2013. Demographics, surgical techniques, complications, patient-reported outcomes, and radiographic outcomes were collected and analyzed. For continuous variables, the comparison between groups was conducted using a one-way analysis of variance. Of all 235 patients included in the study, 70.5% were women (190 hips). The mean follow-up period was 12 years (range, 10 to 18). The femoral head sizes of 28- mm, 32 mm, and 36 mm were used in 50, 26, and 197 cases, respectively. Mean acetabular inclination and anteversion angles were 39.2 ± 7.1° and 14.9 ± 3.5°. RESULTS: There were 5 hips revised at a mean 4.6 years (range, 0.1 to 7.1). One revision was squeaking-related. Squeaking was also reported by 8 other patients, but did not require revision. Other reasons for revision were early infection in 2 cases, stem loosening in 1 case, and stem fracture in 2 cases. The survival analysis for any causes for revision as an endpoint was 96.7% (95% confidence interval 0.313%-2.57%). CONCLUSION: We report excellent mean 12-year follow-up results regarding the complications and survivorship of the fourth generation CoC bearings.

Long-Term Survivorship of Cemented and Uncemented Polyethylene Liner Exchange.

BACKGROUND: Revision surgery is usually required for complications associated with total hip arthroplasty (THA). Significant morbidity can be associated with revision THA and thus some may only revise the liner of the original metal back component if it is found to be well fixed. We compare the long-term survivorship of cemented and uncemented head-liner THA exchange surgeries and possible causes. METHODS: Between 2000 and 2018, we reviewed cases from our arthroplasty database who underwent THA revision for head-liner exchange. We stratified our cohort into 2 groups: cemented and uncemented liners. Patients were followed clinically and radiographically to determine survivorship of the exchanges for both cemented and uncemented liners. Implant survivorship was measured using a competing risk analysis considering death and patients lost to follow-up as competing risks. RESULTS: A total of 84 patients (85 hips) underwent head-liner exchange surgery during the study period (21 cemented and 64 uncemented liners). The mean follow-up time was 6.9 years, with 75.3% and 24.7% of patients having been revised due to non-dislocation and dislocation causes, respectively. Two cemented liners (9.5%) and 11 uncemented liners (17.2%) required revision. The survival analysis of all head-liner revision was 86.4% at 18 years. Survival estimates liner exchanges due to dislocation versus non-dislocation groups were 57.3% versus 82.7% respectively (P = .034). CONCLUSION: The present study shows improved survivorship of head-liner exchanges performed due to non-dislocation etiology compared to dislocation etiology, but no difference in survivorship between cemented and uncemented head-liner exchange. LEVEL OF EVIDENCE: Level III.

Elective Total Hip Arthroplasties in Nonagenarians-Age Does Matter: A National Surgical Quality Improvement Program Study.

BACKGROUND: The aim of this study is to assess the independent effect of age on the risk of postsurgical complications and death in patients undergoing total hip arthroplasty (THA). METHODS: The National Surgical Quality Improvement Program was used to identify all patients aged 65 years and older who underwent primary THA from 2011 to 2017. Study outcomes were minor complications, major life-threatening complications, and 30-day mortality. Predictors of outcomes were identified using bivariate analyses and age was added into the final logistic regression models with stepwise selection. RESULTS: A total of 74,361 patients were included in the analysis. Mean (standard deviation) age was 735 years (6.46), median 72.0 years; 1,119 (1.50%) patients were ≥90 years. Females comprised 60.6% of the patient sample. The incidence of major life-threatening complications, minor complications, and death was 939/74,361 (1.3%), 2,098 (2.8%) and 154 (0.2%) respectively. When added to the final models, age was significantly associated with an increased risk of postoperative complications and mortality. CONCLUSION: Elective THA in relatively healthy nonagenarians should only be considered among patients with disabling osteoarthritis demonstrating a restricted quality of life. Although THA can substantially improve patient wellbeing, our findings suggest that surgeons and patients must consider the impact of age on patient course and outcomes regardless of the presence of comorbidities. LEVEL OF EVIDENCE: Level II, prognostic study.

Total ankle arthroplasty results using fixed bearing CT-guided patient specific implants in posttraumatic versus nontraumatic arthritis.

BACKGROUND: Patients who undergo total ankle arthroplasty (TAA) for end-stage posttraumatic ankle osteoarthritis have previously reported more complications and lower satisfaction than those with non-traumatic etiologies. The purpose of this study was to evaluate clinical and radiographic outcomes in these two patient groups after TAA using a newer generation implant. METHODS: Patients underwent TAA with a third generation implant using CT-based patient-specific cutting guides. Patients were evaluated clinically using the Foot and Ankle Ability Measure (FAAM) and radiographically at a mean follow up of 32, and 24 months respectively. RESULTS: Forty-one patients were studied (26 posttraumatic, 15 nontraumatic). There were no significant differences between the two study groups in FAAM scores (p=0.3423) and radiographic measurements. CONCLUSION: We were able to show comparable results in terms of patient satisfaction, short term clinical and radiographic results between traumatic and nontraumatic patients using newer patient specific implant systems.

Long-Term Outcome of Small Head Metal-On-Metal Total Hip Arthroplasty: A 15-to-22 Year Follow-Up.

BACKGROUND: The Metasul articular interface was a second-generation metal-on-metal (MoM) total hip arthroplasty (THA) that was introduced as a promising interface with improved manufacturing technology, better clearances, and enhanced metal hardness. In December 2001, the manufacturer recalled these implants due to the failure of cup osseointegration. METHODS: Between 1997 and 2004, 168 consecutive primary Metasul THAs were performed in 144 patients. Most patients received a cementless femoral and porous-coated acetabular component with 28 mm head. A competing risk analysis was performed for determination separately for bearing surface-related, recalled bearing failure, and end point revision for any reason. For clinical patient evaluation, we used Harris hip score and University of California at Los Angeles scores. Cobalt and chromium ion level measurement and standard radiographic assessment was performed. RESULTS: Of the 168 THAs, 19 hips were revised at a mean period of 15 years as follows: 12 of them were due to recalled acetabular component, five hips had noninterface-related complication, and two true interface surface failure. The survival distribution function of all hips with revision for any reason was 88.4%, for bearing interface relation 98.8%, and 92.6% for recalled cups. The mean Harris hip score and University of California at Los Angeles scores were 85 and 6, respectively, and the median Co and Cr blood levels were 1.0 and 0.91 µg/L. CONCLUSION: Excluding the recalled components, Metasul articular interface has performed extremely well at a minimum follow-up of 15 years in this relatively young population. There were two interface-related revisions in the entire cohort.

Radiographic, Functional, and Oncologic Outcomes of Cemented Modular Proximal Femur Replacement Using the "French Paradox" Technique.

BACKGROUND: Endoprostheses are frequently used in the management of tumors involving the proximal femur. Aseptic loosening is a common complication that has been linked to the cementing technique. The "French paradox" is well-known cementing technique in the arthroplasty literature. No previous reports have assessed loosening in proximal femur replacements using this technique. We examined rates of femoral stem aseptic loosening in proximal femur replacements, functional outcomes, complications, and oncologic outcomes. METHODS: We conducted a retrospective review of 47 patients who underwent proximal femur replacement between 2000 and 2019. Two reviewers evaluated preoperative and postoperative radiographs using the International Society of Limb Salvage scoring system and Barrack criteria for stem loosening. The acetabulum was evaluated according to the criteria of Baker et al. Functional outcomes were assessed using Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score. The mean follow-up was 44 months. RESULTS: The mean International Society of Limb Salvage scores for the 2 reviewers were 86% ± 6% and 84% ± 6%. The first reviewer graded femoral stem loosening as "possibly loose" in 2 patients, one of whom was graded as possibly loose by the second reviewer. The 2 reviewers found no acetabular erosion in 16 (70%) and 15 (65.4%) patients, respectively. The mean Musculoskeletal Tumor Society score and Toronto Extremity Salvage Score at last follow-up were 61% and 72%, respectively. Twenty complications occurred in 13 patients, and 5 patients experienced local recurrence. CONCLUSION: Despite complications, we showed favorable femoral component survival rates. Cementing the proximal femur prosthesis with tight canal fit and thin cement mantle is a viable option for the short and medium term. LEVEL OF EVIDENCE: III.

Injectable Chitosan Hydrogels with Enhanced Mechanical Properties for Nucleus Pulposus Regeneration.

IMPACT STATEMENT: A thermosensitive chitosan-based hydrogel was developed, which mimics the mechanical properties of the human nucleus pulposus (NP) tissue and provides a suitable environment for seeded NP cells to live and produce glycosaminoglycans. This scaffold is injectable through 25G needle and rapidly gels in vivo at body temperature. It has the potential to restore mechanical properties and stimulate biological repair of the degenerated intervertebral disc (IVD). It could therefore be used for the minimally invasive treatment of degenerated IVD, which affects more than one person out of five in the world.

Short Link N promotes disc repair in a rabbit model of disc degeneration.

BACKGROUND: The degeneration of the intervertebral disc (IVD) is characterized by proteolytic degradation of the extracellular matrix, and its repair requires the production of an extracellular matrix with a high proteoglycan-to-collagen ratio characteristic of a nucleus pulposus (NP)-like phenotype in vivo. At the moment, there is no medical treatment to reverse or even retard disc degeneration. The purpose of the present study was to determine if a low dose of short link N (sLN), a recently discovered fragment of the link N peptide, could behave in a manner similar to that of link N in restoring the proteoglycan content and proteoglycan-to-collagen ratio of the disc in a rabbit model of IVD degeneration, as an indication of its potential therapeutic benefit in reversing disc degeneration. METHODS: Adolescent New Zealand white rabbits received an annular puncture with an 18-gauge needle into two noncontiguous discs to induce disc degeneration. Two weeks later, either saline (10 µL) or sLN (25 µg in 10 µL saline) was injected into the center of the NP. The sLN concentration was empirically chosen at a lower molar concentration equivalent to half that of link N (100 µg in 10 µL). The effect on radiographic, biochemical and histologic changes were evaluated. RESULTS: Following needle puncture, disc height decreased by about 25-30% within 2 weeks and maintained this loss for the duration of the 12-week study; a single 25-µg sLN injection at 2 weeks partially restored this loss in disc height. sLN injection led to an increase in glycosaminoglycans (GAG) content 12 weeks post-injection in both the NP and annulus fibrosus (AF). There was a trend towards maintaining control disc collagen-content with sLN supplementation and the GAG-to-collagen ratio in the NP was increased when compared to the saline group. CONCLUSIONS: When administered to the degenerative disc in vivo, sLN injection leads to an increase in proteoglycan content and a trend towards maintaining control disc collagen content in both the NP and AF. This is similar to link N when it is administered to the degenerative disc. Thus, pharmacologically, sLN supplementation could be a novel therapeutic approach for treating disc degeneration.

Link N as a therapeutic agent for discogenic pain.

Neurotrophins (NTs) are the major contributors of sensory axonal sprouting, neural survival, regulation of nociceptive sensory neurons, inflammatory hyperalgesia, and neuropathic pain. Intervertebral disc (IVD) cells constitutively express NTs. Their expression is upregulated by proinflammatory cytokines present in the IVD during degeneration, which can promote peripheral nerve ingrowth and hyperinnervation, leading to discogenic pain. Currently, there are no targeted therapies that decrease hyperinnervation in degenerative disc disease. Link N is a naturally occurring peptide with a high regenerative potential in the IVD. Therefore, the suitability of Link N as a therapeutic peptide for suppressing NTs, which are known modulators and mediators of pain, was investigated. The aim of the present study is to determine the effect of Link N on NTs expression, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and their cognate receptors TrkA and TrkB as they are directly correlated with symptomatic back pain. Furthermore, the neurotransmitter (substance P) was also evaluated in human annulus fibrosus (AF) cells stimulated with cytokines. Human AF cells isolated from normal IVDs were stimulated with interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) in the presence or absence of Link N. NGF release in the media was evaluated by Western blotting. Total RNA was isolated and gene expression was measured using real-time PCR. Gene expression of NGF, BDNF, TrkA, and TrkB significantly decreased in human disc cells stimulated with either IL-1ß or TNF-α supplemented with Link N when compared to the cells stimulated only with IL-1ß or TNF-α. NGF protein expression was also suppressed in AF cells coincubated with Link N and IL-1ß when compared to the cells stimulated only with IL-1ß. Link N can suppress the stimulation of NGF, BDNF, and their receptors TrkA and TrkB in AF cells in an inflammatory milieu. Thus, coupled with previous observations, this suggests that administration of Link N has the potential to not only repair the discs in early stages of the disease but also suppress pain.

Short Link N Stimulates Intervertebral Disc Repair in a Novel Long-Term Organ Culture Model that Includes the Bony Vertebrae.

Link N (DHLSDNYTLDHDRAIH) is a peptide that occurs naturally in the intervertebral discs (IVDs) and cartilage as a result of proteolytic cleavage of Link protein. Several studies have identified Link N as a growth factor capable of stimulating matrix synthesis in these tissues. We have recently discovered that annulus fibrosus cells can release an enzyme (possibly cathepsin K) that can further cleave Link N resulting in an eight amino acid peptide, we called short Link N (sLink N). Separately, we recently developed and validated an organ culture model that has the vertebrae attached (vIVDs; IVD with intact vertebrae). The aims of this study were (i) to examine if sLink N has the potential to repair early degenerate discs and (ii) to determine if this new model can be used to test potential drugs for disc repair. To determine if sLink N was able to stimulate repair of the degenerate disc, vIVDs with trypsin-induced degeneration (DG) were used. After 4 weeks of culture, the proteoglycan content measured as glycosaminoglycans was stimulated by sLink N in the degenerated discs, and the staining of proteoglycan was observed throughout the tissue irrespective of its proximity to the cells. The quantity of extractable type II collagen and aggrecan was also increased when the degenerate discs were treated with sLink N. Taken together, the results suggest that sLink N can increase key disc matrix molecules, namely type II collagen and aggrecan. Thus sLink N is an attractive peptide for tissue engineering and regeneration of the disc due to its anabolic effects. Finally, we show the feasibility of using the long-term whole organ culture system with adjacent intact vertebrae for studying the DG and regeneration of the IVD.

Hospital Discharge within 2 Days Following Total Hip or Knee Arthroplasty Does Not Increase Major-Complication and Readmission Rates.

BACKGROUND: The rising costs of total knee arthroplasty (TKA) and total hip arthroplasty (THA) have resulted in a substantial economic burden on the U.S. health-care system. Recent efforts to contain these costs have targeted hospital length of stay. However, shorter hospital admissions have raised concerns over possible increases in complications and readmission rates. The purpose of this study was to assess whether early discharge, from 0 to 2 days postoperatively, was associated with increased 30-day major complications and readmissions compared with standard discharge, 3 to 4 days following THA or TKA. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried to identify all patients who underwent an elective, primary unilateral THA or TKA between 2011 and 2012. For each procedure, 2 groups were created consisting of patients discharged from 0 to 2 days (early discharge) and those discharged from 3 to 4 days (standard discharge). Patient demographics and perioperative variables were compared between both discharge groups. Multivariable logistic-regression models were used to assess the independent effect of length of stay on 30-day major-complication and readmission rates. RESULTS: A total of 31,044 patients who underwent TKA and 19,909 patients who underwent THA were included. Overall, patients who were discharged early were younger and had fewer medical comorbidities and a lower American Society of Anesthesiologists (ASA) score. The multivariable logistic-regression model revealed that early discharge was not associated with increased odds of major complications following TKA (odds ratio [OR] = 0.95; 95% confidence interval [CI] = 0.75 to 1.20; p = 0.64). Furthermore, early discharge following THA was found to be an independent predictor against major complications (OR = 0.75; 95% CI = 0.58 to 0.95; p = 0.02). Lastly, early discharge was not an independent risk factor for hospital readmission following THA or TKA. CONCLUSIONS: Early discharge was not an independent risk factor for 30-day major complications or readmissions following THA or TKA. Rather, increased major complications and readmissions were attributed to patient comorbidities and perioperative variables. Early discharge within the first 2 days postoperatively for risk-stratified patients appears feasible without compromising patient care. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Navigated vs Conventional Total Knee Arthroplasty: Is There a Difference in the Rate of Respiratory Complications and Transfusions?

BACKGROUND: Proponents of navigation in total knee arthroplasty (TKA) report lower rates of systemic embolization and perioperative bleeding compared to conventional TKA given that breeching the intramedullary canal is not required. METHODS: We queried the National Surgical Quality Improvement Program to compare perioperative respiratory complications and transfusions between navigated and conventional TKA. We identified 2008 patients who underwent navigated TKA. These patients were matched 4:1 to a control group of 8026 patients. RESULTS: Conventional TKA resulted in similar odds of having a respiratory complication compared to navigated TKA (odds ratio = 1.35, P = .44). However, conventional TKA was found to be an independent predictor for requiring a transfusion perioperatively (odds ratio = 1.90, P < .001). CONCLUSION: Use of navigation in TKA results in less perioperative transfusions but has no influence on the rate of respiratory complications.

Development of a Large Animal Long-Term Intervertebral Disc Organ Culture Model That Includes the Bony Vertebrae for Ex Vivo Studies.

Intervertebral disc (IVD) degeneration is a common cause of low back pain. Testing potential therapeutics in the regeneration of the disc requires the use of model systems. Although several animal models have been developed to investigate IVD degeneration, they are technically challenging to prepare, expensive, present with limitations when performing biomechanical studies on the disc, and are impractical in large-scale screening of novel anabolic and scaffolding agents. An IVD organ culture system offers an inexpensive alternative. In the current paradigm, the bony endplates are removed to allow for nutrient diffusion and maintenance of disc cell viability. Although this is an excellent system for testing biologics, it results in concave cartilage endplates and, as such, requires special platens for loading purposes in a bioreactor as flat ones can overload the annular disc region leading to improper loading. Furthermore, the absence of bone makes it unsuitable for applying complex cyclic loading, a topic of interest in the study of chronic progressive degeneration, as multiaxial loading is more representative of daily forces encountered by the IVD. We have developed and validated a novel long-term IVD organ culture model that retains vertebral bone and is easy to prepare. Our model is ideal for testing potential drugs and alternate-based therapies, in addition to investigating the long-term effects of loading paradigms on disc degeneration and repair.

Major Complications and Transfusion Rates After Hemiarthroplasty and Total Hip Arthroplasty for Femoral Neck Fractures.

BACKGROUND: Postoperative complications and perioperative transfusions are common after hemiarthroplasty or total hip arthroplasty (THA) and can lead to increased morbidity and mortality. METHODS: The National Surgical Quality Improvement Program Database was queried to compare 30-day major complications and perioperative transfusions after femoral neck fractures. RESULTS: A total of 4058 patients were included in the study: 3192 were treated with hemiarthroplasty and 866 with THA. Multivariable logistic regression analysis revealed that having a THA was not an independent risk factor for major complications (odds ratio = 0.8, P = .18) but was an independent risk factor for requiring transfusions (odds ratio = 1.68, P < .001). CONCLUSION: The risk of major complications is influenced by patient factors rather than the choice of procedure. However, THA was a risk factor for transfusions after controlling for all other variables.

Comparison of US and Canadian Perioperative Outcomes and Hospital Efficiency After Total Hip and Knee Arthroplasty.

IMPORTANCE: The combination of an aging population, growing number of medical interventions, and surging economic burden of health care has renewed interest in reevaluating and exploring new health care models. OBJECTIVES: To compare the performance of the US and Canadian health care systems by assessing major complications following primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) and to measure the efficiency of both health care models by comparing the postoperative length of stay. DESIGN, SETTING, AND PARTICIPANTS: With patients grouped according to the country where they underwent surgery, we queried the National Surgical Quality Improvement Program database to identify 55,335 Canadian and US patients who underwent primary elective THA or TKA between January 1, 2011, and December 31, 2012. MAIN OUTCOMES AND MEASURES: Differences in patient demographics, as well as the rate of 30-day major complications and length of stay, were compared between patients hospitalized in the United States and Canada. RESULTS: Baseline characteristics were similar between the groups. Most US patients underwent general anesthesia (THA, 61.8%; TKA, 59.4%); Canadian patients received more regional anesthesia (THA, 78.7%; TKA, 81.0%). Patients in the United States received more transfusions postoperatively (THA, 9.0% more; TKA, 6.4% more; P < .001) and had shorter hospitalizations (THA, 1.4 days less; TKA, 1.3 days less; P < .001) with a greater proportion of patients discharged to rehabilitation facilities (THA, 21.6% more; TKA, 26.6% more; P < .001). With results reported as incidence rate ratios (95% CIs), after adjusting for all other variables, risk factors, and adverse outcomes, having surgery in Canada increased the postoperative length of stay by 57% (1.57 [1.53-1.61]) for THA and 49% (1.49 [1.46-1.52]) for TKA. With results reported as odds ratios (95% CIs), major complications were significantly more common in Canada following TKA (1.65 [1.31-2.07]) but not THA (1.09 [0.79-1.51]). CONCLUSIONS AND RELEVANCE: The rate of major complications was significantly higher in Canada following TKA, but there was no significant difference following THA. Patients undergoing the procedures in US hospitals also had substantially shorter lengths of hospital stay, perhaps reflecting more efficient postoperative care and discharge planning in those facilities.

Perioperative Complications and Length of Stay After Revision Total Hip and Knee Arthroplasties: An Analysis of the NSQIP Database.

Goals of this study were (1) to determine the 30-day complications after aseptic revision hip arthroplasty (RHA) and aseptic revision knee arthroplasty (RKA) and (2) to identify patient-related risk factors predicting major complications and prolonged hospital stay beyond 7 days. The National Surgical Quality Improvement Program (NSQIP) database was used to identify patients with RHA (n=2643) or RKA (n=2425) from 2011 to 2012. The 30-day mortality rates for RHA and RKA were 1.0% and 0.1% (P<0.001) and the overall complication rates were 7.4% and 4.7% (P<0.001) for RHA and RKA, respectively. Multivariable analysis showed that preoperative anemia is the most important modifiable independent predictor for both major complications and prolonged hospital stay after RHA and RKA.