Increasing Burden of Total Hip Arthroplasty Revisions in Patients Between 45 and 64 Years of Age

Revision Arthroplasty Among Medicare Patients in the United States - Arthroplasty Surgeons are Doing More for Less

BACKGROUND

Previously documented trends of major joint arthroplasty demonstrate increasing volume and decreasing reimbursement for primary total knee and total hip arthroplasty procedures. As such, the purpose of this study was to evaluate trends in revision knee and hip arthroplasty volume and true Medicare reimbursements to physicians.

METHODS

The publicly accessible Centers for Medicare and Medicaid files were evaluated. Data were retrieved from the Part B National Summary Data File and queried for revision knee and hip arthroplasty billed to Medicare from 2000 to 2021. The total charge submitted to Medicare, Medicare reimbursement, number of revision arthroplasty surgeries performed, and average reimbursement per surgery were collected for each year. All monetary data were adjusted for inflation to 2021 dollars.

RESULTS

There were 492,360 revision total knee arthroplasty surgeries and 424,163 revision hip arthroplasty procedures billed to Medicare from 2000 to 2021. Medicare was billed a total of $919,603,674.86 for revision knee and $862,979,761.57 for revision hip arthroplasty during that time. Medicare reimbursed physicians an average of $1,499.89 per knee revision and $1,603.32 per hip revision surgery. The total volume of revision knee arthroplasty increased by 9,380 (62%) and revision hip decreased by 1,743 (9%) from the year 2000 to 2021. However, there was a decrease of average reimbursement per procedure of more than 37% ($1,987.14 to 1,254) and 39% ($2,149.87 to 1,311.17), respectively.

CONCLUSIONS

Despite a notable increase in the volume of revision total knee and stagnant revision hip arthroplasty, total billings to and reimbursements from Medicare for these procedures have not changed markedly per year. Importantly, this means that physicians are conducting more of these high-impact procedures yearly, while being reimbursed per procedure at a declining rate. This may indicate a need to re-assess billing and reimbursement rates for revision arthroplasty, in the context of the ever-increasing inflation rate.

Incidence and risk factors of postoperative pulmonary complications following total hip arthroplasty revision: a retrospective Nationwide Inpatient Sample database study

BACKGROUND

Postoperative pulmonary complications (PPCs) are among the most severe complications following total hip arthroplasty revision (THAR), imposing significant burdens on individuals and society. This study examined the prevalence and risk factors of PPCs following THAR using the NIS database, identifying specific pulmonary complications (SPCs) and their associated risks, including pneumonia, acute respiratory failure (ARF), and pulmonary embolism (PE).

METHODS

The National Inpatient Sample (NIS) database was used for this cross-sectional study. The analysis included patients undergoing THAR based on NIS from 2010 to 2019. Available data include demographic data, diagnostic and procedure codes, total charges, length of stay (LOS), hospital information, insurance information, and discharges.

RESULTS

From the NIS database, a total of 112,735 THAR patients in total were extracted. After THAR surgery, there was a 2.62% overall incidence of PPCs. Patients with PPCs after THAR demonstrated increased LOS, total charges, usage of Medicare, and in-hospital mortality. The following variables have been determined as potential risk factors for PPCs: advanced age, pulmonary circulation disorders, fluid and electrolyte disorders, weight loss, congestive heart failure, metastatic cancer, other neurological disorders (encephalopathy, cerebral edema, multiple sclerosis etc.), coagulopathy, paralysis, chronic pulmonary disease, renal failure, acute heart failure, deep vein thrombosis, acute myocardial infarction, peripheral vascular disease, stroke, continuous trauma ventilation, cardiac arrest, blood transfusion, dislocation of joint, and hemorrhage.

CONCLUSIONS

Our study revealed a 2.62% incidence of PPCs, with pneumonia, ARF, and PE accounting for 1.24%, 1.31%, and 0.41%, respectively. A multitude of risk factors for PPCs were identified, underscoring the importance of preoperative optimization to mitigate PPCs and enhance postoperative outcomes.

Biomechanics of a collum-fixated short stem in total hip arthroplasty

Background

Biomechanical reconstruction of the hip significantly impacts the clinical outcome and implant survival. Our knowledge is limited of the ability of neck-stabilised prostheses to restore hip biomechanics. We hypothesised that hip biomechanics, specifically leg length and global offset (GO), may be restored to an acceptable range using the Primoris™ stem.

Methods and material

In this retrospective study, we analysed 152 patients who underwent total hip replacement (THA) using the short collum-fixated stem Primoris™.The primary outcomes were hip parameters measured by x-ray following THA using the Primoris™ stem. After surgery, the biomechanical parameters used were measured at the arthroplasty and the native contralateral side of the same x-ray. The X-rays were taken one year after the patient's surgery.1. GO.2. Leg length discrepancy (LLD).3. Neck shaft angle (NSA).

Results

We recorded an average GO of -3.4 mm (standard deviation (SD) 7.2) and an average LLD of +3.8 mm (SD 6.4). Furthermore, we registered an average 14-degree NSA increase (SD 7.4).

Conclusion

The Primoris™ neck-stabilised stem enabled hip anatomy restoration to a favourable range with respect to GO and LLD as the average difference fell within ±5 mm. However, the stem tended to be implanted in valgus.

Cemented versus uncemented stems for revision total hip replacement: A systematic review and meta-analysis

BACKGROUND

The popularity of uncemented stems in revision total hip arthroplasty (THA) has increased in the last decade.

AIM

To assess the outcomes of both cemented and uncemented stems after mid-term follow up.

METHODS

This study was performed following both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for systematic reviews and meta-analysis guidelines. Articles were chosen irrespective of country of origin or language utilized for the article full texts. This paper included studies that reviewed revision THA for both cemented or uncemented long stems.

RESULTS

Three eligible studies were included in the meta-analysis. Analysis was conducted by using Review Manager version 5.3. We computed the risk ratio as a measure of the treatment effect, taking into account heterogeneity. We used random-effect models. There were no significant differences found for intraoperative periprosthetic fractures [risk ratio (RR) = 1.25; 95% confidence interval (CI): 0.29-5.32; P = 0.76], aseptic loosening (RR = 2.15, 95%CI: 0.81-5.70; P = 0.13), dislocation rate (RR = 0.50; 95%CI: 0.10-2.47; P = 0.39), or infection rate (RR = 0.99, 95%CI: 0.82-1.19; P = 0.89), between the uncemented and the cemented long stems for revision THA after mid-term follow-up.

CONCLUSION

This study has evaluated the mid-term outcomes of both cemented and uncemented stems at first-time revision THA. In summary, there were no significant differences in the dislocation rate, aseptic loosening, intraoperative periprosthetic fracture and infection rate between the two cohorts.

Updates on Biomaterials Used in Total Hip Arthroplasty (THA)

One of the most popular and effective orthopedic surgical interventions for treating a variety of hip diseases is total hip arthroplasty. Despite being a radical procedure that involves replacing bone and cartilaginous surfaces with biomaterials, it produces excellent outcomes that significantly increase the patient's quality of life. Patient factors and surgical technique, as well as biomaterials, play a role in prosthetic survival, with aseptic loosening (one of the most common causes of total hip arthroplasty failure) being linked to the quality of biomaterials utilized. Over the years, various biomaterials have been developed to limit the amount of wear particles generated over time by friction between the prosthetic head (metal alloys or ceramic) and the insert fixed in the acetabular component (polyethylene or ceramic). An ideal biomaterial must be biocompatible, have a low coefficient of friction, be corrosion resistant, and have great mechanical power. Comprehensive knowledge regarding what causes hip arthroplasty failure, as well as improvements in biomaterial quality and surgical technique, will influence the survivability of the prosthetic implant. The purpose of this article was to assess the benefits and drawbacks of various biomaterial and friction couples used in total hip arthroplasties by reviewing the scientific literature published over the last 10 years.

Serum CD64 as a Marker for Chronic Periprosthetic Joint Infection

Background

Serum cluster of differentiation 64 (CD64) has emerged as a diagnostic test for musculoskeletal infections. The purpose of this study was to evaluate the utility of serum CD64 in diagnosing periprosthetic joint infections (PJIs) compared to conventional markers like white blood count (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and interleukin-6 (IL-6).

Methods

A prospective case-control study on patients undergoing revision hip or knee arthroplasty surgery >6 weeks after their index surgery was performed at a single institution. Whole blood samples were drawn within 24 hours prior to revision surgery for white blood count, ESR, CRP, IL-6, and CD64. Intraoperative cultures were obtained during the revision, and PJI was defined using the major criteria from the 2018 Musculoskeletal Infection Society criteria. Two-sample Wilcoxon rank-sum test and Fisher's exact test were used to determine if there were significant differences in serum laboratory values between patients with and without infection. The sensitivity, specificity, positive predictive value (PPV), negative predictive value, and accuracy of each test were calculated.

Results

With an average age of 67 years, 39 patients with 15 revision THAs and 24 TKAs, were included. 19 patients (48.7%) were determined to have PJI. Patients with PJI had significantly higher CD64 (P = .036), CRP (P = .016), and ESR (P = .045). CD64 had the highest specificity (100%) and PPV (100%), moderate accuracy (69.2%), but low sensitivity (37.0%) and negative predictive value (62.5%).

Conclusions

Given the high specificity, PPV, and accuracy, CD64 may be an excellent confirmatory test to help diagnose PJI.

Modular Proximal Body Exchange for Re-revision Total Hip Arthroplasty: Rarely Utilized and Moderately Successful

BACKGROUND

Modular fluted tapered stems (MFTSs) are commonly used in revision total hip arthroplasty (THA) and provide the option of exchanging the proximal modular portion to address future surgical problems without complete femoral revision. We are unaware of any data documenting the frequencies, indications, and outcomes of modular proximal body exchange in re-revision THA.

METHODS

Between 1997 and 2019, we performed 57 modular proximal body exchanges among 8,079 revision THAs at our institution. Indications and outcomes were documented at a mean follow-up of 3.4 years (range, 0 to 12.8).

RESULTS

Modular proximal body exchange was performed on 47 of 1375 (3%) of MFTSs implanted. The indications for all 57 modular proximal body exchanges performed during the study period were dislocation in 30 (53%), partial resection for periprosthetic joint infection (PJI) in 13 (23%), modular junction failure in 8 (14%), surgical exposure in 4 (7%), and concurrently with trochanteric osteotomy nonunion fixation in 2 (4%). At final follow-up, subsequent re-revisions occurred in 10 of 30 (33%) of modular proximal body exchanges indicated for dislocation and in 5 of 13 of those indicated for PJI. One modular junction subsequently fractured after modular proximal body exchange.

CONCLUSIONS

Modular proximal body exchange of a MFTS is an uncommon procedure most often performed for treatment of hip dislocation or PJI. It is moderately successful with approximately one-third of cases requiring subsequent re-revision. This procedure is often performed with modular component exchange alone, but can also be helpful to facilitate complex acetabular exposure. These data provide useful information to surgeons and patients undergoing this procedure.

Do patient-reported outcome measures improve after aseptic revision total hip arthroplasty?

BACKGROUND

The purpose of this study was to determine patient-reported outcome measures (PROMs) changes in: (1) pain, function and global health; and (2) predictors of PROMs in patients undergoing aseptic revision total hip arthroplasty (rTHA) using a multilevel model with patients nested within surgeon.

METHODS

A prospective cohort of 216 patients with baseline and 1-year PROMs who underwent aseptic rTHA between January 2016 and December 2017 were analysed. The most common indication for rTHA was aseptic loosening, instability, and implant failure. The PROMs included in this study were HOOS Pain and HOOS Physical Function Short-form (PS), Veterans RAND-12 Physical Component Score (VR-12 PCS), and VR-12 Mental Component Score (MCS). Multivariable linear regression models were constructed for predicting 1-year PROMs.

RESULTS

Mean 1-year PROMs improvement for aseptic revisions were 30.4 points for HOOS Pain and 22.1 points for HOOS PS. Predictors of better pain relief were patients with higher baseline pain scores. Predictors of better 1-year function were patients with higher baseline function and patients with a posterolateral hip surgical approach during revision. Although VR-12 PCS scores had an overall improvement, nearly 50% of patients saw no improvement or had worse physical component scores. Only 30.7% of patients reported improvements in VR-12 MCS.

CONCLUSIONS

Overall, patients undergoing aseptic rTHA improved in pain and function PROMs at 1 year. Although global health assessment improved overall, nearly half of aseptic rTHA patients reported no change in physical/mental health status. The associations highlighted in this study can help guide the shared decision-making process by setting expectations before aseptic revision THA.

Comparison of Walking Quality Variables between End-Stage Osteonecrosis of Femoral Head Patients and Healthy Subjects by a Footscan Plantar Pressure System

Background and Objectives: Osteonecrosis of the femoral head (ONFH) is a progressive disease with a complex etiology and unknown pathogenesis. Gait analysis can objectively assess the functional behavior of the foot, thus revealing essential aspects and influencing factors of gait abnormalities. The aim of this study was to evaluate the differences in spatiotemporal parameters, static and dynamic plantar pressure parameters, and symmetry indices between patients with ONFH and healthy subjects. Materials and Methods: The study population consisted of 31 ONFH patients and 31 healthy volunteers. Gait parameters were obtained from the plantar pressure analysis system for both the ONFH and healthy groups. The symmetry index was calculated according to a formula, including spatiotemporal parameters, static and dynamic plantar pressure distribution, percentage of regional impulse, and percentage of the restricted contact area. Results: Compared with healthy controls, patients with ONFH had slower walking speed, shorter step length and stride length, and increased stride time, stance time, and percentage of stance. patients with ONFH had lower plantar static pressure on the affected side and higher contralateral plantar static pressure during stance than controls. During walking, the peak pressures in all regions on the affected side and the peak pressure in the toe 1 and metatarsal 3 regions on the healthy side were lower in ONFH patients than in controls. The percentage of contact area and regional impulse in the heel of both limbs were higher in ONFH patients than in the control group. The symmetry indexes of stride time, stance time, step length, maximum force, impulse and contacted area were significantly increased in ONFH patients compared to controls, with decreased symmetry. Conclusions: Osteonecrosis of the femoral head leads to characteristic changes in plantar pressure distribution. These changes may be interpreted as an attempt by patients with ONFH to reduce the load on the affected limb. Plantar pressure analysis may assist in the diagnosis of ONFH and can provide an objective quantitative indicator for the assessment of subsequent treatment outcomes.

Comparison of minimally-invasive fibular supporting of T-type with traditional bloody iliac flap metastasis for osteonecrosis of the femoral head at ARCO stage II

Purpose

Our research mainly evaluates the clinical efficacy of two surgical methods in the treatment of osteonecrosis of the femoral head (ONFH) at ARCO stage II, aiming to provide optimal hip-preserving treatment of ONFH.

Method

From October 2018 to September 2020, 48 patients (59 hips) met the inclusion criteria and randomized. 24 cases (29 hips) in experimental group were treated with minimally-invasive fibular supporting of T-type; 24 cases (30 hips) in control group were treated with traditional bloody iliac flap metastasis. We will compare some intraoperative and postoperative conditions.

Result

The operation time in experimental group was 37 (6) minutes, in control group was 130 (21.75) minutes; the length of surgical incision in two groups was 3.7 (0.7) cm and 12.85 (2.68) cm. The intraoperative blood loss in two groups was 69 (21) ml and 363 (87) ml; the postoperative VAS score of the experimental group on day 1, day 3, day 7 after surgery was 5.5 (2), 3.5 (1), 0 (1); the control group was 6 (1.75), 4 (1), 3 (1). The data differences between above groups have statistically significant. The follow-up time of two groups was (33.86 ± 5.66) months and (35.67 ± 4.69) months. The bone graft healing time in two groups was (14.21 ± 1.93) months and (13.83 ± 2.34) months. The Harris hip scores of two groups at the last follow-up were 90 (7.5) and 86.5 (8.5). The survival rates of two groups were 79.31% (23/29) and 76.67% (23/30). The difference was no statistically significant in above groups (P > 0.05).

Conclusion

The two different bone graft implantation showed satisfactory early outcomes. Compared to the control group, the experimental group has the advantages of lesser pain, lesser blood loss, lesser trauma and shorter operation time. It may be a choice as bone graft for the treatment of ONFH at early stage.

Impact of Indication for Revision THA on Resource Utilization

BACKGROUND

Demographic variables play an important role in outcomes following revision total hip arthroplasty (rTHA). Surgical and in-patient variables as well as outcomes vary between indications for rTHA. The purpose of this study was to investigate the impact of the indication for the rTHA on costs and postoperative outcomes.

METHODS

This retrospective cohort analysis investigated all patients who underwent unilateral, aseptic rTHA at an academic orthopaedic specialty hospital who had at least 1-year postoperative follow-up. In total, 654 patients were evaluated and categorized based on their indication for aseptic rTHA. Demographics, direct and total procedure costs, surgical factors, postoperative outcomes, and re-revision rates were collected and compared between indications.

RESULTS

Younger patients had the greatest leg length discrepancy (LLD) and older patients had the highest incidence of periprosthetic fracture (PPF) (P = .001). The greatest proportion of full revisions were found for LLD (16.7%) and head/polyethylene liner-only revisions for metallosis/adverse tissue reaction (100%). Operative time was significantly longest for LLD revisions and shortest for metallosis/adverse tissue reaction revisions (P < .001). Length of stay was longest for periprosthetic fracture and shortest for LLD and stiffness/heterotopic ossification (P < .001). Re-revision rate was greatest for implant failure and lowest for LLD. Total cost was highest for PPF (148.9%) and lowest for polyethylene liner wear (87.7%).

CONCLUSIONS

Patients undergoing rTHA for indications such as PPF and aseptic loosening were associated with longer operative times, length of stay and higher total and direct costs. Therefore, they may need increased perioperative attention with respect to resource utilization, risk stratification, surgical planning, and cost-reducing measures.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Long-Term Outcomes of Revision Total Hip Arthroplasty Using a Tapered and Fluted Modular Stem: A Mean Follow-Up of 16 Years

BACKGROUND

Tapered modular stems are increasingly used in revision total hip arthroplasty (THA) with deficient femoral bone stock. This study aimed to report the long-term outcomes of revision THA using a tapered and fluted modular stem.

METHODS

Between December 1998 and February 2006, 113 revision THAs (110 patients) were performed with a tapered and fluted modular stem at a single institution. Hip radiographs were used to identify stem subsidence, stability, and femoral radiolucency. Final outcomes were assessed in 72 hips (70 patients), with a minimum follow-up of 10 years.

RESULTS

The mean follow-up duration was 16 years (range, 10-23). At the final evaluation, the Harris Hip Score improved from a mean of 41 points (range, 10-72) preoperatively to 83 points (range, 56-100) (P < .001). Six femoral re-revisions were performed for the following reasons: 1 aseptic loosening, 2 stem fractures, and 3 infections. One stem fracture occurred at the modular junction after 14 years, and the other at a more distal location after 15 years. Stem subsidence was >5 mm in 6 hips (9.1%), but secondary stability was achieved in all stems. Osseointegration was observed in 63 (95.5%) hips. Stem survivorship was 91.1% with an end point of any re-revision and 94.6% for aseptic re-revision.

CONCLUSION

A tapered and fluted modular stem demonstrated excellent implant survivorship with reliable bony fixation at a mean follow-up of 16 years. This type of stem can be a durable option for revision THA in patients who have femoral defects.

Artificial intelligence accurately identifies total hip arthroplasty implants: a tool for revision surgery

BACKGROUND

A critical part in preoperative planning for revision arthroplasty surgery involves the identification of the failed implant. Using a predictive artificial neural network (ANN) model, the objectives of this study were: (1) to develop a machine-learning algorithm using operative big data to identify an implant from a radiograph; and (2) to compare algorithms that optimise accuracy in a timely fashion.

METHODS

Using 2116 postoperative anteroposterior (AP) hip radiographs of total hip arthroplasties from 2002 to 2019, 10 artificial neural networks were modeled and trained to classify the radiograph according to the femoral stem implanted. Stem brand and model was confirmed with 1594 operative reports. Model performance was determined by classification accuracy toward a random 706 AP hip radiographs, and again on a consecutive series of 324 radiographs prospectively collected over 2019.

RESULTS

The Dense-Net 201 architecture outperformed all others with 100.00% accuracy in training data, 95.15% accuracy on validation data, and 91.16% accuracy in the unique prospective series of patients. This outperformed all other models on the validation (p < 0.0001) and novel series (p < 0.0001). The convolutional neural network also displayed the probability (confidence) of the femoral stem classification for any input radiograph. This neural network averaged a runtime of 0.96 (SD 0.02) seconds for an iPhone 6 to calculate from a given radiograph when converted to an application.

CONCLUSIONS

Neural networks offer a useful adjunct to the surgeon in preoperative identification of the prior implant.

Epidemiology of revision hip replacement in Italy: a 15-year study

Background

Over the past two decades, there has been an increase in the amount of primary total hip arthroscopies (THA) which in turn has increased the need for THA revision surgeries. The purpose of this study was to quantify the increase in THA revision in Italy, evaluate the causes and types of THA procedures performed.

Methods

The data regarding revision hip prosthetic replacements performed both in public and private structures between 2001 and 2015 was collected by the National Hospital Discharge reports (SDO) carried out by the Italian Ministry of Health.

Results

Overall, 109,746 Revision Hip Replacements (RHR) were performed in Italy from 2001 to 2015 in the adult population. The study shows a greater number of female patients underwent surgery between 2001 and 2015 and the 75- to 79-year age group had the highest incidence of THA revision. The main causes for THA revision were found to be “Mechanical complication of internal orthopedic device implant and graft” (31.5%), “Infection and inflammatory reaction due to internal joint prosthesis” (10.5%) and “Mechanical loosening of prosthetic joint” (8.3%).

Conclusions

Revision hip replacement is growing and heavily affecting the population between 65 and 89 years and the main causes of THA revision have been quantified. The average length of hospitalization (LOS) was found to have decreased over the 14-year study period. Understanding the causes and risk factors for revision is essential in identifying avoidable complications and improving preventative care for patients undergoing primary implantation to decrease the revision burden.

Long-Term Follow-Up of Conventional Polyethylene in Total Hip Arthroplasty in Young Patients: Heightened Wear-Related Complications Are Observed at the Beginning of the Third Decade

BACKGROUND

Conventional polyethylene (CPE) was used widely in the past as a bearing surface in total hip arthroplasty (THA). As CPE THAs age and the revision burden continues to grow, it is increasingly important to understand the durability and failure mechanisms of this bearing material. Currently, such long-term data remain limited, particularly in younger, more active patients in whom wear issues are of greater concern.

METHODS

We retrospectively reviewed 90 hips (77 patients) that underwent primary THA with CPE bearings on cobalt chrome femoral heads at age ≤50 years at 20-year minimum follow-up (mean 21.6 [20-23]). We analyzed polyethylene wear rates, clinical outcomes (modified Harris Hip Score, University of California, Los Angeles Activity Score), and implant survivorship.

RESULTS

Wear analysis revealed a median linear wear rate of 0.113 mm/y (95% CI 0.102-0.148) and a median volumetric wear rate of 41.20 mm³/y (95% CI 43.5-61.0). Modified Harris Hip Scores remained 37 points above preoperative baseline (P < .001) and University of California, Los Angeles scores 1.4 points above baseline (P = .018) at 21.6-year mean follow-up. Twenty-nine hips (32.2%) were revised, 20 of which (22.2%) were wear-related at a median of 15.4 years (interquartile range 11.4-19.5). Survivorship free from wear-related revision was 95.6% (95% CI 88.7-98.3), 87.9% (78.6-93.3), 78.1% (49.6-66.5), and 61.1% (41.3-67.0) at 10, 15, 20, and 25 years.

CONCLUSION

Wear-related issues developed at increasingly high rates after 15 years, suggesting the need for surveillance after this time. The long-term wear and survivorship data of this study may be used as a benchmark when evaluating the performance of contemporary bearings in young, active THA patients.

Extended Trochanteric Osteotomy Closure Performed Before or After Canal Preparation and Stem Impaction Does Not Affect Axial Stability

BACKGROUND

An extended trochanteric osteotomy (ETO) safely addresses femoral component removal during challenging revision total hip arthroplasty. However, no prior study has evaluated whether a difference in axial stability exists between ETO closure performed before (reconstitution) or after (scaffolding) canal preparation and stem impaction. We hypothesized that given the absence of clinical reports of outcome differences despite the wide use of both practices, no significant difference in the initial axial stability would exist between the 2 fixation techniques.

METHODS

ETOs were performed and repaired using the reconstitution technique for the 6 right-sided femora and the scaffolding technique for the six left-sided femora. The 195-mm long, 3.5°-tapered splined titanium monobloc stems were impacted into 6 matched pairs of human fresh cadaveric femora. Three beaded cables were placed in a standardized fashion on each specimen, 1 for prophylaxis against osteotomy propagation during reaming/impaction and 2 to close the ETO. Stepwise axial loading was performed to 2600 N or until failure, which was defined as subsidence >5 mm or femoral/cable fracture.

RESULTS

All specimens successfully resisted axial testing, with no stem in either ETO repair group subsiding >2 mm. The mean subsidence for the reconstitution group was 0.9 ± 0.4 mm, compared to 1.2 ± 0.5 mm for the scaffolding group (P = .2).

CONCLUSION

In this cadaveric model with satisfactory proximal bone stock, no difference existed between the reconstitution and scaffolding ETO repair techniques, and both provide sufficient immediate axial stability in a simulated revision total hip arthroplasty setting under physiologic loads.

Postoperative acetabular component position in revision hip arthroplasty: a comparison of the anterior and posterior approaches

BACKGROUND

While previously considered unsuitable for revision total hip arthroplasty (rTHA), the direct anterior approach (DAA) can be extended to allow for safe acetabular component revision. In primary hip arthroplasty, the DAA and its associated fluoroscopy, has been shown to produce more acceptable component positioning. However, there is little data comparing the DAA to the posterior approach (PA) for rTHA. We hypothesised that, the DAA with intraoperative fluoroscopy would allow for more precise acetabular component positioning when compared to those performed using a PA.

METHODS

50 consecutive patients (25 DAA and 25 PA) undergoing rTHA were included. Radiographic analysis of postoperative acetabular component position was then performed. Univariate and multivariate analyses was performed to assess the contribution of approach on cup positioning inside classically defined "safe zones".

RESULTS

Baseline patient characteristics were similar. The PA was associated with more cups placed outside the Lewinnek (48% vs. 12%, p = 0.005) and the Danoff (52% vs. 28%, p = 0.083) "safe zones" when compared to the DAA. Multivariate analysis revealed that operative approach was the only patient or surgical factor associated with component position outside of the "safe zones" (Lewinnek [OR = 13.6; 95% CI, 2.12-87.9, p = 0.006] and Danoff [OR = 7.7; 95% CI, 1.48-40.1, p = 0.015]).

CONCLUSION

Our results suggest that the DAA allows for more reproducible and precise cup placement in RTHA. The safe-zone paradigm remains a useful index of accurate cup positioning and the DAA, with use of intraoperative fluoroscopy, offers more consistent acetabular component positioning when compared to the PA.

The Impact of Surgeon Variability on Patient-Reported Outcomes in Total Hip Arthroplasty

BACKGROUND

Patient-related and surgery-related factors have been shown to be drivers of outcomes after total hip arthroplasty (THA); however, the impact of intersurgeon variability is poorly understood. The purpose of this study is to assess the following: (1) overall effect of surgeon on 1-year patient-reported outcome measures (PROMs), length of stay (LOS), discharge disposition, and 90-day readmission following THA; and (2) variability in 1-year PROMs among surgeons.

METHODS

A prospective cohort of 3,695 patients who underwent THA between 2016 and 2018 was included. Seventy-eight percent of patients completed 1-year follow-up. Thirty-one surgeons from a large healthcare system were included. Likelihood ratio tests analyzed the relationship among surgeon and 1-year Hip Disability and Osteoarthritis Outcome Score (HOOS)-Pain, HOOS-Physical Function Short-Form, HOOS-Joint Replacement, University of California, Los Angeles activity score, Patient Acceptable Symptom State, LOS, discharge disposition, and 90-day readmission. Mixed-effect proportional odds and logistic regression models were used to determine variable importance for each outcome.

RESULTS

In total, 90.5% of patients responded positively to 1-year Patient Acceptable Symptom State. There was a significant association among surgeon and 1-year PROMs, LOS, discharge disposition (P < .001), and readmission (P = .002). For HOOS-Pain, Physical Function Short-Form, and Joint Replacement, surgeon (Akaike information criterion increase: 34.6, 18.7, 17.1, respectively) was a greater contributor to outcome than patient-level factors, including age, gender, and comorbidity. Differences in the highest and lowest median probability of achieving any given score on 1-year PROMs ranged from 11% to 18.5%. Variability was not explained by approach (P = .431) or case volume (correlation coefficient, ρ = 0.19).

CONCLUSION

Surgeon-level variability appears to be a greater driver of 1-year PROMs than some patient-level characteristics. Incorporating surgeon as a variable is beneficial for model-fitting and important for increasing value in THA.

National Decline in Knee Fusions Performed for Salvage of Chronic Periprosthetic Total Knee Infections

The primary purpose of this study was to study and compare rates of two salvage operations for patients with chronically infected total knee arthroplasties: (1) knee arthrodesis and (2) above knee amputation (AKA). An analysis was performed comparing the inpatient hospital characteristics and complications between the two procedures. Secondarily, we presented rates of all surgically treated periprosthetic total knee infections over a 6-year period. Using the Nationwide Inpatient Sample, we identified all patients with a periprosthetic infection (International Classification of Diseases, Ninth Revision [ICD-9] 996.66) from 2009 to 2014. Subsequently, we identified surgically treated total knee infections through the following ICD-9 codes: 00.80 (all component revision), 00.84 (liner exchange), 80.06 (removal of prosthesis), 84.17 (AKA), and 81.22 (knee fusion). From 2009 to 2014, the annual incidence of surgically treated total knee periprosthetic infections increased by 34.9% nationally, while the annual incidence of primary total knees increased by only 13.9%. Salvage operations (AKA and knee fusion) represented 5.8% of all surgically treated infections. The rate of knee fusions decreased from 1.9% of surgically treated infections in 2009 to 1.4% in 2014 (p < 0.05), while the rate of AKA stayed steady at 4.5% of cases over the 6-year period. Length of stay was significantly shorter in the knee fusion group (7.9 vs. 10.8 days, p < 0.05), but total hospital costs were higher (33,016 vs. 24,933, p < 0.05). In the multivariable adjusted model, patients undergoing knee fusion had significantly decreased odds of being discharged to skilled nursing facility (odds ratio: 0.42, 95% confidence interval: 0.31-0.58). The annual incidence of surgically treated periprosthetic total knee infections is increasing. The rate of knee arthrodesis for chronic periprosthetic total knee infections is decreasing. Reasons for this downward trend in knee fusions should be evaluated carefully as knee fusions have shown to have the potential advantage of improved mobility and decreased patient morbidity for chronic PJI. The level of evidence is III.

Overstretching Expectations May Endanger the Success of the “Millennium Surgery”

Total hip arthroplasty (THA) is an extremely successful treatment strategy. Patient expectations, however, have increased; if not properly guided by surgeons, at present, patients expect next to pain-free restoration of the joint and a fast return to work and sports. While the revision rates after THA also increased in younger patients, knowledge on musculoskeletal loads still remains sparse, and the current recommendations on postoperative rehabilitation are based on expert opinions only. The aim of this study was to unravel biomechanical contact conditions in “working age” (&lt;60 years, 53.5 ± 3.0 years) and “retirement age” (&gt;60 years, 67.7 ± 8.6 years) patients during activities recommended post-THA. We hypothesized that working age patients would show substantially increased hip contact loads compared to older patients. The in vivo joint contact force (Fres) and torsion torque (Mtors), reflecting the main contact load situation, experienced during activities of daily living and sports activities were measured in a unique group of 16 patients with instrumented THA. We summarized patient activities and sports recommendations after THA mentioned within the literature using PubMed (without claim of completeness). The measurements showed that younger working age patients experienced significant (p = 0.050) increased Mtors (21.52 ± 9.11 Nm) than older retirement age patients (13.99 ± 7.89 Nm) by walking. Bowling, as a recommended low-impact sport, was associated with Fres of up to 5436 N and Mtors of up to 108 Nm in the working age group, which were higher than the Fres (5276 N) and Mtors (71 Nm) during high-impact soccer. Based on our results, age was proven to be a discriminator in joint loading, with working age patients presenting with increased loads compared to retirement age patients, already during daily activities. The current patient recommendations have led to further increased joint loadings. If THA cannot be delayed in a patient, we propose counselling patients on a carefully considered return to sports, focusing on low-impact activities, as indicated hereby. The findings from this work illustrate the need to provide critical feedback to patient expectations when returning to work and sports activities. Patients returning to more intensive sports activities should be carefully monitored and advised to avoid as much overloading as possible.

Racial and Ethnic Disparities in Hip Fracture Surgery Care in the United States From 2006 to 2015: A Nationwide Trends Study

BACKGROUND

Racial and ethnic disparities in the surgical treatment of hip fractures have been previously reported, demonstrating delayed time to surgery and worse perioperative outcomes for minority patients. However, data are lacking on how these disparities have trended over time and whether national efforts have succeeded in reducing them. The aim of this study was to investigate temporal trends in racial and ethnic disparities in perioperative metrics for patients undergoing hip fracture surgery in the United States from 2006 to 2015.

METHODS

The National Inpatient Sample was queried for White, Black, Hispanic, and Asian patients who underwent hip fracture surgery between 2006 and 2015. Perioperative metrics, including delayed time to surgery (≥2 calendar days from admission to surgical intervention), length of stay (LOS), total inpatient complications, and mortality, were trended over time. Changes in racial and ethnic disparities were assessed using linear and logistic regression models.

RESULTS

During the study period, there were persistent disparities in delayed time to surgery for White versus Black, Hispanic, and Asian patients (eg, White versus Black: 30.1% versus 39.7% in 2006 and 22% versus 28.8% in 2015, Ptrend> 0.05 for all). Although disparities in total LOS remained consistent for White versus Black patients (Ptrend= 0.97), these disparities improved for White versus Hispanic and Asian patients (eg, White versus Hispanic: 4.8 days versus 5.3 in 2006 and 4.1 days versus 4.4 in 2015, Ptrend < 0.05 for both).

DISCUSSION

Racial and ethnic disparities were persistent in time to surgery and discharge disposition for hip fracture surgery between White and minority patients from 2006 to 2015 in the United States. These disparities particularly affected Black patients. Although there were encouraging signs of improving disparities in the LOS, these findings highlight the need for renewed orthopaedic initiatives and healthcare reform policies aimed at reducing perioperative disparities in orthopaedic trauma care.

The Wear Rate and Survivorship in Total Hip Arthroplasty Using a Third-generation Ceramic Head on a Conventional Polyethylene Liner: A Minimum of 15-year Follow-up

Purpose

Materials and Methods

Results

Conclusion

Outcome of revision surgery in recurrent dislocation of primary total hip arthroplasty

BACKGROUND

The cause of recurrent dislocation following primary total hip arthroplasty (THA) is multifactorial. A re-dislocation rate of up-to 34% following revision is reported. The aim of this study was to determine the re-dislocation rates following revision for recurrent THR dislocation.

METHODOLOGY

Patients who underwent revision for recurrent dislocation between January 2008 and January 2015 were identified. We identified the date and type of primary implant, overall number and reasons for dislocation, revision implant details and complication data.

RESULTS

Over an 8-year period, 24 patients underwent revision. The median age was 77 (68-85) years, median time to first dislocation was 78 (23-160) months and median number of dislocations was 3 (2-4) with a mean follow-up of 18 months. Socket Mal-Orientation (10) and Abductor deficiency (5) were the main causes of recurrent dislocation. 21 patients (88%) underwent revision of both components, 1 patient underwent isolated cup revision and 2 patients had revision of acetabular component with insertion of a BioBall. There were no dislocations within 90 days of revision surgery. 4 patients had late dislocations (3 recurrent, 1 isolated). There was no significant increase risk of dislocation after revision surgery in the neck of femur group (p = 0.467).

CONCLUSIONS

We report favourable outcomes for revision of both components for recurrent dislocation with no dislocations within 90 days. The overall late dislocation rate was 16.7%, however, these patients have settled following closed reduction. Due to its multifactorial aetiology, both component revision can be considered in this patient population.

Surgical cup placement affects the heating up of total joint hip replacements

The long-term success of highly effective total hip arthroplasty (THA) is mainly restricted by aseptic loosening, which is widely associated with friction between the head and cup liner. However, knowledge of the in vivo joint friction and resulting temperature increase is limited. Employing a novel combination of in vivo and in silico technologies, we analyzed the hypothesis that the intraoperatively defined implant orientation defines the individual joint roofing, friction and its associated temperature increase. A total of 38,000 in vivo activity trials from a special group of 10 subjects with instrumented THA implants with an identical material combination were analyzed and showed a significant link between implant orientation, joint kinematics, joint roofing and friction-induced temperature increase but surprisingly not with acting joint contact force magnitude. This combined in vivo and in silico analysis revealed that cup placement in relation to the stem is key to the in vivo joint friction and heating-up of THA. Thus, intraoperative placement, and not only articulating materials, should be the focus of further improvements, especially for young and more active patients.

Reimbursements for Revision Total Hip Arthroplasty Have Increased for Hospitals but Not for Surgeons

BACKGROUND

With increases in total hip arthroplasty procedures the need for revision total hip arthroplasty (rTHA) has increased as well. This study aims to analyze the trends in hospital charges and payments relative to corresponding surgeon charges and payments in a Medicare population for rTHA for aseptic revisions, stage 1 and stage 2 revisions.

METHODS

The 5% Medicare sample database was used to capture hospital and surgeon charges and payments related to 4449 patients undergoing aseptic revision, 517 for stage 1 revision, and 300 for stage 2 revision in between the years 2004 and 2014. Two values were calculated: (1) the ratio of hospital to surgeon charges (CM) and (2) the ratio of hospital to surgeon payments (PM). Year-to-year variation and trends in patient demographics, Charlson Comorbidity Index (CCI), length of stay (LOS), CM, and PM were evaluated.

RESULTS

The mean CCI for aseptic revisions and stage 1 revisions did not significantly change (P < .088 and P < .063). The CCI slightly increased for stage 2 revisions (P < .04). The mean LOS decreased significantly over time in all 3 procedure types. The CM increased by 39% (P < .02) in aseptic revisions, 109% in stage 1 revisions (P < .001) but did not significantly change in stage 2 revisions (P < .877). PM for aseptic revisions increased around 103% (P < .001), 107% for stage 1 revisions (P < .001), and 9.7% for stage 2 revisions (P < .176).

CONCLUSION

Hospital charges and payments relative to surgeon charges and payments have increased substantially for THA aseptic revisions, stage 1 revisions, and stage 2 revisions despite stable patient complexity and decreasing LOS.

Utilization Patterns, Efficacy, and Complications of Venous Thromboembolism Prophylaxis Strategies in Revision Hip and Knee Arthroplasty as Reported by American Board of Orthopaedic Surgery Part II Candidates

BACKGROUND

The optimum venous thromboembolism (VTE) prophylaxis strategy to minimize risk of VTE and bleeding complications following revision total hip and knee arthroplasty (rTHA/rTKA) is controversial. The purpose of this study is to describe current VTE prophylaxis patterns following revision arthroplasty procedures to determine efficacy, complication rates, and prescribing patterns for different prophylactic strategies.

METHODS

The American Board of Orthopaedic Surgery Part II (oral) examination case list database was analyzed. Current Procedural Terminology codes for rTHA/rTKA were queried and geographic region, VTE prophylaxis strategy, and complications were obtained. Less aggressive prophylaxis patterns were defined if only aspirin and/or sequential compression devises were utilized. More aggressive VTE prophylaxis patterns were considered if any of low-molecular-weight heparin (enoxaparin), warfarin, rivaroxaban, fondaparinux, or other strategies were used.

RESULTS

In total, 6387 revision arthroplasties were included. The national rate of less aggressive VTE prophylaxis strategies was 35.3% and more aggressive in 64.7%. Use of less aggressive prophylaxis strategy was significantly associated with patients having no complications (89.8% vs 81.9%, P < .001). Use of more aggressive prophylaxis patterns was associated with higher likelihood of mild thrombotic (1.2% vs 0.3%, P < .001), mild bleeding (1.7% vs 0.6%, P < .001), moderate thrombotic (2.6% vs 0.4%, P < .001), moderate bleeding (6.2% vs 4.0%, P < .001), severe bleeding events (4.4% vs 2.4%, P < .001), infections (6.4% vs 3.8%, P < .001), and death within 90 days (3.1% vs 1.3%, P < .001). There were no significant differences in rates of fatal pulmonary embolism (0.1% vs 0.04%, P = .474). Subgroup analysis of rTHA and rTKA patients showed similar results.

CONCLUSION

The individual rationale for using a more aggressive VTE prophylaxis strategy was unknown; however, more aggressive strategies were associated with higher rates of bleeding and thrombotic complications. Less aggressive strategies were not associated with a higher rate of thrombosis.

LEVEL OF EVIDENCE

Therapeutic Level III.

Association of Sex With Risk of 2-Year Revision Among Patients Undergoing Total Hip Arthroplasty

IMPORTANCE

The worldwide population is aging and includes more female individuals than male individuals, with higher rates of total hip arthroplasty (THA) among female individuals. Although research on this topic has been limited to date, several studies are currently under way.

OBJECTIVES

To evaluate the association between sex and 2-year revision after THA.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from statewide databases in New York and California between October 1, 2015, and December 31, 2018. Patients 18 years or older with osteoarthritis who underwent THA and had sex recorded in the database were included in the analysis.

EXPOSURE

Total hip arthroplasty.

MAIN OUTCOMES AND MEASURES

The outcome of interest was the difference in early, all-cause revision surgery rates after primary THA between women and men. The association of sex with the revision rate was examined using Cox proportional hazards regression analysis.

RESULTS

Of 132 826 patients included in the study, 74 002 (55.7%) were women; the mean (SD) age was 65.9 (11.0) years, and the median follow-up time was 1.3 years (range, 0.0-3.0 years). The 2-year revision rate was 2.5% (95% CI, 2.4%-2.6%) among women and 2.1% (95% CI, 2.0%-2.2%) among men. After adjusting for demographic characteristics, comorbidities, and facility volume, a minimal clinically meaningful difference was observed in revision rates despite women having a higher risk of all-cause revision compared with men (hazard ratio, 1.16; 95% CI, 1.07-1.26; P < .001). The risk of revision was increased among women compared with men in the subgroup of patients who were younger than 55 years (hazard ratio, 1.47; 95% CI, 1.20-1.81; P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study, no clinically meaningful difference in all-cause revision rates after primary THA was found between men and women at 2-year follow-up. The modest difference in the risk of revision between men and women in a small subgroup of patients younger than 55 years suggests that the risk of revision in this population should be studied further.

Uncemented or cemented stems in first-time revision total hip replacement? An observational study of 867 patients including assessment of femoral bone defect size

Background and purpose - Uncemented stems are gradually replacing cemented stems in hip revision surgery. We compared the risk of re-revision between uncemented and cemented revision stems and assessed whether the different fixation methods are used in similar femoral bone defects.Patients and methods - 867 patients operated on with uncemented or cemented stems in first-time hip revision surgery due to aseptic loosening performed 2006-2016 were identified in the Swedish Hip Arthroplasty Register. Preoperative femoral bone defect size was assessed on radiographs of all patients. Cox regression models were fitted to estimate the adjusted risk of re-revision during different postoperative time periods. Re-revision of any component for any reason, and stem re-revision, as well as risk of cause-specific re-revision was estimated.Results - Most patients in both fixation groups had Paprosky class IIIA femoral bone defects prior to surgery, but there were more severe bone defects in the cemented group. The adjusted risk of re-revision of any component for any reason was higher in patients with uncemented compared with those with cemented revision stems during the first 3 years after index surgery (hazard ratio [HR] 4, 95% confidence interval [CI] 2-9). From the 4th year onward, the risk of re-revision of any component for any reason was similar (HR 0.5, CI 0.2-1.4). Uncemented revision stems conferred a higher risk of dislocation compared with cemented stems (HR 5, CI 1.2-23) during the first 3 years.Interpretation - Although not predominantly used in more complex femoral defects, uncemented revision stem fixation confers a slightly higher risk of re-revision during the first years, but this risk is attenuated after longer follow-up.

Surface Texturing of Prosthetic Hip Implant Bearing Surfaces: A Review

More than 300,000 total hip replacement surgeries are performed in the United States each year to treat degenerative joint diseases that cause pain and disability. The statistical survivorship of these implants declines significantly after 15-25 years of use because wear debris causes inflammation, osteolysis, and mechanical instability of the implant. This limited longevity has unacceptable consequences, such as revision surgery to replace a worn implant, or surgery postponement, which leaves the patient in pain. Innovations such as highly cross-linked polyethylene and new materials and coatings for the femoral head have reduced wear significantly, but longevity remains an imminent problem. Another method to reduce wear is to add a patterned microtexture composed of micro-sized texture features to the smooth bearing surfaces. We critically review the literature on textured orthopedic biomaterial surfaces in the context of prosthetic hip implants. We discuss the different functions of texture features by highlighting experimental and simulated results documented by research groups active in this area. We also discuss and compare different manufacturing techniques to create texture features on orthopedic biomaterial surfaces and emphasize the key difficulties that must be overcome to produce textured prosthetic hip implants.

Short-stem total hip arthroplasty is not associated with an earlier return to work compared to a straight-stem design

Return to work (RTW) has been specifically identified as a high priority in patients undergoing total hip arthroplasty (THA). This investigation sought to assess the effect of the stem design on patients' RTW. Secondly, the study aimed to identify risk factors that lead to a delayed RTW. Questionnaires inquiring about RTW, employment history, educational level, type of work, physical demands and joint awareness were administered by post. Further data were collected from patients' hospital records. 176 patients who underwent THA using a short-stem and 97 patients using a straight-stem design were compared. The median return to work time was 10 weeks [IQR 7-14 weeks], with no significant difference between the two groups (short stems vs. straight stems; 10 [IQR 7-14] vs. 11 [7.5-13.5] weeks; p = 0.693). In the multivariate linear regression analysis, self-employment vs. employee (p = 0.001), dimension of preoperative workload (p = 0.001), preoperative sick leave (p < 0.001), and hospital length of stay (LOS) (p < 0.001) independently affected the period until work was resumed. The Forgotten-Joint-Score-12 showed no significant difference between the two groups. The data show that the majority of THA patients can expect to resume work and stem design has no impact on RTW. Employees with preoperative sick leave, prolonged hospital LOS and low workload are at higher risk for a delayed RTW.

Long-term survival and clinical outcomes of non-vascularized autologous and allogeneic fibular grafts are comparable for treating osteonecrosis of the femoral head

Background

Osteonecrosis of the femoral head (ONFH) is a disabling disease, which often involves young patients. Recently, various hip-preserving surgeries were recommended to delay total hip arthroplasty (THA).

Questions/purposes

This study aimed to compare clinical outcomes and survival rate in the long-term follow-up between core decompression combined with a non-vascularized autologous fibular graft (group A) and an allogeneic fibular graft (group B) for the treatment of ONFH.

Patients and methods

We retrospectively evaluated 117 patients (153 hips) with ONFH (Association Research Circulation Osseous [ARCO] stages IIa to IIIc) who underwent the abovementioned hip-preserving surgeries between January 2003 and June 2012. The mean (range) follow-up times (years) were 12.9 (7–16) and 9.3 (6–16) in groups A and B, respectively. Clinical outcomes were assessed using the Harris Hip Score (HHS), visual analog scale (VAS) score, and forgotten joint score (FJS). A survival analysis was performed using the Kaplan-Meier method. The end point was THA.

Results

Groups A and B showed postoperative improvements, respectively, in HHS from 65 ± 7.2 to 80.3 ± 14.5 and from 66 ± 5.9 to 82.4 ± 13.6 (p < 0.05), and in VAS score from 6.3 ± 1.1 to 2.3 ± 1.6 and from 6.1 ± 1 to 2.2 ± 2.2 (p < 0.05). However, no significant differences in the HHS, VAS score, and hip FJS at the last follow-up (p > 0.05) and 15-year survival rate (84.1% and 86%, respectively, p > 0.05) were found between groups A and B.

Conclusions

Autologous and allogeneic fibular grafts can attain equally good clinical outcomes and high survival rates in long-term follow-up, and thus can greatly delay THA owing to good bone osseointegration and sufficient mechanical support. Notably, the ratio of failure will increase when patients were more than 37 years old.

Level of evidence

Level III, therapeutic study

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02246-3.

Vancomycin prophylaxis for revision hip arthroplasty in penicillin and cephalosporin sensitive patients: Is dose adjustment necessary in accordance with blood loss and fluid replacement?

OBJECTIVE

The aims of this study were (1) to investigate the changes in the serum concentration of prophylactically administrated vancomycin in the perioperative period of revision hip arthroplasty in penicillin/cephalosporin-allergic patients, (2) to assess whether the postoperative re-administration of vancomycin is needed, and (3) to determine the relationships of vancomycin serum concentration with blood loss, body weight, and fluid replacement in such patients.

METHODS

This study consisted of 29 patients (20 females, 9 males; mean age=63.3 years; age range=45-79 years) with a history of penicillin/cephalosporin allergy undergoing revision hip arthroplasty secondary to aseptic loosening or periprosthetic fractures. Serum vancomycin levels were measured (1) before administration of vancomycin, (2) at the time of skin incision, (3) every 1,5 hours thereafter until the end of the operation, (4) during the skin closure, and (5) after three and 12 hours from the initial dosage. Data regarding body weight, amounts of intraoperative blood loss, fluid and blood replacements and postoperative wound drainage were recorded.

RESULTS

The average blood loss, fluid replacement, and drain volume were 1280.3±575.8 (500-2700) mL, 2922.6±768.8 (1700-4600) mL, and 480.2±163.7 (200-850) mL, respectively. The mean levels of serum vancomycin were 46.3±21.8 (14.1-80.7) mg/L at the time of skin incision, 17.9±4.7 (9.4-30.9) and 9.8±2.2 (4.3-13.8) mg/L after 1.5 and 3 hours from the beginning of the surgery and 5.1±1.1 (2.9-6.8)mg/L after 12th hour postoperatively. The measured vancomycin levels were below the effective serum concentrations (< 5 mg/L) for 18 patients at 12 hours the administration of the first dose. A moderate level negative correlation between the blood loss/body weight ratio and vancomycin levels was found (p=0.004, r=-0.493). Predictive ROC curve analysis resulted in determining a blood loss volume higher than 1150 ml and a blood loss/body weight ratio higher than 18,5 is significant to estimate the vancomycin level below the minimum effective serum level at 12th hour postoperatively (AUC=0.793±0.16, p=0.009, AUC=0.753) 26±0.12, p=0.025, respectively).

CONCLUSION

Evidence from this study has indicated vancomycin concentration at 12th hour is below the effective level in most patients. Thus, earlier repetitive infusion of vancomycin seems to be necessary in penicillin/cephalosporin-allergic patients undergoing revision hip arthroplasty, especially in those with high blood loss.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Nationwide Analysis of Lower Extremity Periprosthetic Fractures

BACKGROUND

Although the annual incidence of primary total joint arthroplasty is increasing, trends in the annual incidence of periprosthetic fractures have not been established. This study aimed to define the annual incidence of periprosthetic fractures in the United States.

METHODS

Inpatient admission data for 60,887 surgically treated lower extremity periprosthetic fractures between 2006 and 2015 were obtained from the National Inpatient Sample database. The annual incidence of periprosthetic fractures was defined as the number of new cases per year and presented as a population-adjusted rate per 100,000 US individuals. Univariable methods were used for trend analysis and comparisons between groups.

RESULTS

The national annual incidence of periprosthetic fractures presented as a population-adjusted rate of new cases per year peaked in 2008 (2.72; 95% confidence interval [95% CI], 2.39-3.05), remained stable from 2010 (1.65; 95% CI, 1.45-1.86) through 2013 (1.67; 95% CI, 1.55-1.8) and increased in 2014 (1.99; 95% CI, 1.85-2.13) and 2015 (2.47; 95% CI, 2.31-2.62). The proportion of femoral periprosthetic fractures managed with total knee arthroplasty revision remained stable (P_trend = .97) with an increase in total hip arthroplasty (THA) revision (P_trend < .001) and concurrent decrease in open reduction and internal fixation (ORIF) (P_trend < .001). Revision THA was significantly more costly than revision total knee arthroplasty (P = .004), and both were significantly more costly than ORIF (P < .001 for both).

CONCLUSION

The annual incidence of periprosthetic fractures remained relatively stable throughout our study period. The proportion of periprosthetic fractures managed with revision THA increased, whereas ORIF decreased. Our findings are encouraging considering the significant burden an increase in periprosthetic fracture incidence would present to the health care system in terms of both expense and patient morbidity.

Adhesin Protein Interaction of Staphylococcus Aureus Bacteria with Various Biomaterial Surfaces

The primary stage of adhesion during implant infection is dominated by interactions of the surface proteins of the bacteria with the substrate atoms. In the current work, molecular dynamics (MD) simulations have been utilized to investigate the mechanics of the associated adhesion forces of bacteria on different surfaces. The unfolding of these adhesion proteins is investigated in order to map these events to earlier experiments on bacterial de-adhesion (using single cell force spectroscopy) with real-life substrates (i.e., ultrahigh molecular weight polyethylene, hydroxyapatite, Ti alloy, and stainless steel). The adhesion of Staphylococcus aureus adhesin (i.e., SpA) is observed by altering their orientation on the silica substrate through MD simulations, followed by capturing unfolding events of three adhesins (SpA, ClfA, and SraP) of variable lengths possessing different secondary structures. The output long-range and short-range interaction forces and consequent visualization of changes in the secondary structure of protein segments are presented during the de-adhesion process. Simulation results are correlated with extracted short-range forces (using Poisson regression) from real-life bacterial de-adhesion experiments. Insights into such protein-substrate interactions may allow for engineering of biomaterials and designing of nonbiofouling surfaces.

Evidence-Based Hospital Procedural Volumes as Predictors of Outcomes After Revision Hip Arthroplasty

BACKGROUND

The aim of this study is to define the evidence-based institutional volume-outcome relationship in revision hip arthroplasty. We hypothesized that high-volume centers would be associated with superior outcomes, and that stratum-specific likelihood ratio (SSLR) analysis would delineate concrete volume thresholds for optimizing outcomes.

METHODS

The Nationwide Readmission Database was queried from 2011 to 2016 for patients undergoing revision hip arthroplasty. SSLR analysis was used to determine hospital volume cutoffs specific for outcomes of interest. Volume categories were confirmed with multivariate regression.

RESULTS

SSLR analysis produced distinct hospital volume cutoffs for all outcomes. Each subsequent volume threshold diminished patients' risk for adverse outcomes. Tertiles were identified for 90-day infection (≤6, 7-51, ≥52 cases per year). Quartiles were found for 90-day readmission (≤5, 6-15, 16-79, ≥80), 90-day prosthesis-related complication (≤5, 6-16, 17-65, ≥66), 90-day dislocation (≤5, 6-19, 20-79, ≥80), and non-home discharge (≤5, 6-15, 16-40, and ≥41). Quintiles were generated for extended length of stay >2 days (≤2, 3-10, 11-20, 21-30, ≥31). Heptiles were produced for medical complications within 90 days (≤2, 3-8, 9-16, 17-51, 52-89, ≥90).

CONCLUSION

This is the first known study to define evidence-based thresholds for the impact of hospital volume on revision joint arthroplasty. This supports the notion that institutional volume functions as a surrogate for protocolized interdisciplinary coordination of care and surgical experience, and that high-volume centers offer enhanced outcomes for complex cases. Additional studies should investigate the potential role for incentivization of such institutions, as they offer optimal outcomes for revision hip arthroplasty.

The etiology of revision total hip arthroplasty: current trends in a retrospective survey of 3450 cases

INTRODUCTION

Over the last years, the design of implants, the surgical approaches, and diagnostic tools changed in primary and revision of total hip arthroplasty. A knowledge of the different causes for revision after total hip arthroplasty is essential to avoid complications and failures. The purpose of this study was to determine trends of the etiology of implant failures over the last years by analyzing indications of revision hip arthroplasty.

METHODS

All the patients who performed revision hip arthroplasties in our institution between 2001 and 2015 were reviewed retrospectively. Patient demographics, the indication for revision surgery as well as the procedure were assessed. Descriptive statistical analyses and association analyses were performed.

RESULTS

Within our collective of 3450 revision hip arthroplasties, a total of 20 different indications were identified and categorized. Overall, 80.8% of the revisions were categorized as aseptic, 19.2% as septic implant failures. Some recently debated diagnoses like low-grade infection showed a high increase in incidence, whereas classic failure mechanisms like polyethylene wear showed a decrease over the time. In addition, the data revealed that cup loosening caused more revision surgeries than stem loosening.

CONCLUSION

This study successfully updated the current knowledge of different failure mechanisms in revision hip arthroplasties. The data proved that cup loosening was the most common failure mechanism in older patients, while in young patients, septic complications showed a high incidence. Probably, due to improved diagnostic tools, the percentage of infection in revision hip arthroplasty increased over the years.

Preoperative opioid use is a risk factor for complication and increased healthcare utilization following revision total knee arthroplasty

INTRODUCTION

Prior literature suggests that opioid use prior to primary arthroplasty procedures results in increased risk for complication. Despite this, it is unknown whether preoperative opioid use increases risk following revision TKA. The purpose of this study was to examine this relationship.

METHODS

The Truven Marketscan® database was used to conduct this retrospective cohort study. Patients undergoing revision TKA for aseptic indication were identified. Opioid prescriptions were collected for one-year preoperatively. Patients were divided into cohorts based on the number of prescriptions received preoperatively. Patients who had an "opioid holiday" (six months opioid naïve period after prior use) were also analyzed. Univariate and multivariate analysis was performed to assess the relationship between preoperative opioids and postoperative complications.

RESULTS

In the year preceding surgery, 84% of patients received an opioid prescription. Compared to opioid naïve patients, continuous preoperative use was associated with higher odds of every examined complication (p ≤ .008). This included PJI (OR 1.77, 95% CI 1.34-2.35, p < .001), VTE (OR 1.56, 95% CI 1.26-1.93, p < .001), opioid overdose (OR 5.03, 95% CI 1.64-15.42, p = .005), and revision surgery (OR 1.80, 95%CI 1.50-2.16, p < .001). Similarly, health care utilization was higher in this group including the following: extended length of stay, non-home discharge, 90-day readmission, and emergency room visits (p ≤ .01). The opioid holiday appeared to confer risk reduction.

CONCLUSIONS

Preoperative opioid use preceding revision TKA is common and is associated with complications following surgery. An opioid holiday appears to provide risk reduction and suggests that opioid use may be a modifiable risk factor.

Sol-gel-assisted micro-arc oxidation synthesis and characterization of a hierarchically rough structured Ta-Sr coating for biomaterials

Tantalum (Ta) is an element with high chemical stability and ductility that is used in orthopedic biomaterials. When utilized, it can produce a bioactive surface and enhance cell-material interactions, but currently, there exist scarce effective methods to introduce the Ta element onto the surface of implants. This work reported a sol-gel-assisted approach combined with micro-arc oxidation (MAO) to introduce Ta onto the surface of the titanium (TC4) substrate. Specifically, this technique produced a substrate with a hierarchically rough structured topography and introduced strontium ions into the film. The films were uniform and continuous with numerous crater-like micropores. Compared with the TC4 sample (196 ± 35 nm), the roughness of Ta (734 ± 51 nm) and Ta-Sr (728 ± 85 nm) films was significantly higher, and both films (Ta and Ta-Sr) showed increased hydrophilicity when compared with TC4, promoting cell attachment. Additionally, the in vitro experiments indicated that Ta and Ta-Sr films have the potential to enhance the recruitment of cells in the initial culture stages, and improve cell proliferation. Overall, this work demonstrated that the application of Ta and Ta-Sr films to orthopedic implants has the potential to increase the lifetime of the implants. Furthermore, this study also describes an innovative strategy to incorporate Ta into implant films.

Epidemiology of Revision Total Hip Arthroplasty: An Indian Experience

BACKGROUND

With increasing numbers of primary total hip replacement (THR), there has been a substantial increase in revision total hip replacement (RTHR) surgeries. RTHR are complex joint reconstruction surgeries involving significant cost, expertise and infrastructure. With its significant socioeconomic impact, we need to keep a close watch on the epidemiological trends of these procedures.

METHODS

We prospectively studied the first-time RTHR performed at our institution for a 7-year period (2011-2017). We looked at patient demographics, the workload of RTHR and its etiology. We reviewed the microbiological profiles of septic revisions.

RESULTS

Of the 1244 THR procedures performed, 260 (21%) were first-time revisions. The predominant cause of revisions was a prosthetic infection (38%) followed by aseptic loosening (33%), instability (15%), peri-prosthetic fracture (11%) and implant breakage (3%). In the aseptic loosening group, 55% of cases had primary cemented implant, 44% had only stem loosening, 31% had cup loosening and 25% had both cup and stem loosening. In the early, midterm, and late-failure groups, prosthetic infection remained the main cause of failure. In 60% of the septic revisions, the offending organisms could not be identified and of those identified most (77%) were gram negative.

CONCLUSION

In our study, the RTHR burden was 21%, which is similar to historic revision data from the west (1998-2001) and twice as compared to recent trends from the west (9-11%). Unlike western data, which show aseptic loosening (30-60%) as the predominant cause of hip revisions, in our study infection was the number one cause (38%).

Persistent Racial Disparities in Utilization Rates and Perioperative Metrics in Total Joint Arthroplasty in the U.S.: A Comprehensive Analysis of Trends from 2006 to 2015

BACKGROUND

Trends in racial disparities in total joint arthroplasty (TJA) care have been documented from 1991 to 2008. However, it remains unknown whether numerous national and orthopaedic-specific efforts to reduce these disparities have been successful. The purpose of this study was to investigate trends in racial disparities in TJA utilization and perioperative metrics between black and white patients in the U.S. from 2006 to 2015.

METHODS

The National Inpatient Sample (NIS) was queried to identify black and white patients who underwent primary total knee arthroplasty (TKA) or primary total hip arthroplasty (THA) between 2006 to 2015. Utilization rates, length of stay in the hospital (LOS), discharge disposition, and inpatient complications and mortality were trended over time. Linear and logistic regression analyses were performed to assess changes in disparities over time.

RESULTS

From 2006 to 2015, there were persistent white-black disparities in standardized utilization rates and LOS for both TKA and THA (p < 0.001 for all; ptrend > 0.05 for all). Moreover, there were worsening disparities in the rates of discharge to a facility (rather than home) after both TKA (white compared with black: 40.3% compared with 47.2% in 2006 and 25.7% compared with 34.2% in 2015, ptrend < 0.001) and THA (white compared with black: 42.6% compared with 41.7% in 2006 and 23.4% compared with 29.2% in 2015, ptrend < 0.001) and worsening disparities in complication rates after TKA (white compared with black: 5.1% compared 6.1% in 2006 and 3.9% compared with 6.0% in 2015, ptrend < 0.001).

CONCLUSIONS

There were persistent, and in many cases worsening, racial disparities in TJA utilization and perioperative care between black and white patients from 2006 to 2015 in the U.S. These results were despite national efforts to reduce racial disparities and highlight the need for continued focus on this issue. Although recent work has shown that elimination of racial disparities in TJA care is possible, the present study demonstrates that renewed efforts are still needed on a national level.

Preoperative Depression Is Associated With Increased Risk Following Revision Total Joint Arthroplasty

BACKGROUND

The incidence of revision total hip (rTHA) and knee (rTKA) arthroplasty continues to increase. Preoperative depression is known to influence outcomes following primary arthroplasty. Despite this, it remains unknown whether the same relationship exists for patients undergoing revision procedures. The purpose of this study, therefore, is to investigate this relationship.

METHODS

This is a retrospective cohort study. Patients undergoing rTHA and rTKA were identified from the Truven MarketScan database. Patients with a diagnosis of prosthetic joint infection were excluded. Two cohorts were created: those with preoperative depression and those without. We included patients who were enrolled in the database for 1 year preoperatively and postoperatively. Demographic and complication data were collected, and statistical analysis was then performed comparing complications between cohorts.

RESULTS

A total of 10,017 patients undergoing rTHA and 13,973 patients undergoing rTKA were included in this study. Of these, 1305 (13.1%) and 2012 (14.4%) had depression, respectively. Multivariate analysis found that, after rTHA, preoperative depression was associated with extended length of stay, nonhome discharge, 90-day readmission, 90-day emergency department visit, prosthetic joint infection, revision surgery, and increased costs (P < .001). Similarly, following rTKA, depression was associated with extended length of stay, nonhome discharge, 90-day readmission, 90-day emergency department visit, revision surgery, and increased costs (P < .001).

CONCLUSION

Depression before revision total joint arthroplasty is common and is associated with increased risk of complication and increased healthcare resource utilization following both rTHA and rTKA. Further research will be needed to delineate to what degree this represents a modifiable risk factor.

Proteins, peptides and peptidomimetics as active agents in implant surface functionalization

The recent impact of implants on improving the human life quality has been enormous. During the past two decades we witnessed major advancements in both material and structural development of implants. They were driven mainly by the increasing patients' demand and the need to address the major issues that come along with the initially underestimated complexity of the bone-implant interface. While both, the materials and design of implants reached a certain, balanced state, recent years brought a shift in focus towards the bone-implant interface as the weakest link in the increasing implant long-term usability. As a result, several approaches were developed. They aimed at influencing and enhancing the implant osseointegration and its proper behavior when under load and stress. With this review, we would like to discuss the recent advancements in the field of implant surface modifications, emphasizing the importance of chemical methods, focusing on proteins, peptides and peptidomimetics as promising agents for titanium surface coatings.

An Ultra-Short Femoral Neck-Preserving Hip Prosthesis: A 2-Year Follow-up Study with Radiostereometric Analysis and Dual X-Ray Absorptiometry in a Stepwise Introduction

BACKGROUND

Total hip arthroplasty (THA) with a diaphyseal stem may risk bone loss. In order to save proximal bone stock in young patients with a high activity level and a long life expectancy, the interest in short stems has evolved. The purpose of this prospective observational cohort study was to evaluate the fixation of, and bone remodeling around, the Primoris femoral neck-preserving hip implant.

METHODS

Fifty younger patients with end-stage osteoarthritis were managed with the Primoris hip implant. We evaluated bone mineral density (BMD) using dual x-ray absorptiometry (DXA) and implant migration using radiostereometric analysis (RSA). A region-of-interest (ROI) protocol for 4 ROIs was applied to assess BMD. The association between BMD and migration was evaluated to determine the fixation of the Primoris implant and bone remodeling in the proximal part of the femur. Follow-up evaluation was performed at regular intervals from day 1 (baseline) until 24 months after surgery.

RESULTS

The major stem migrations were subsidence (Y axis; mean, 0.38 mm) at 6 weeks and varus tilt (rotation) (Z axis; mean, 0.93°) at 6 to 12 months. In ROI4 (the calcar area), a significant gain in bone was found with a mean difference of 4.1% (95% confidence interval [CI], 0.8% to 7.4%; p < 0.02) at 24 months postoperatively. Significant bone loss was found in ROI1 and ROI2, with a mean difference of -4.9% (95% CI, -7.4% to -2.4%; p = 0.0003) and -8.9% (95% CI, -11.5% to -6.2%; p = 0.0001), respectively. Linear regression and multivariate regression analysis showed a significant negative association between maximal total point motion and BMD (p = 0.02, R = 15%; and p < 0.05, R = 26%, respectively).

CONCLUSIONS

The Primoris component showed satisfactory primary stability with promising results at the 24-month follow-up. DXA scans showed limited stress-shielding with the proximal loading pattern of the Primoris. Better bone quality was associated with less implant migration.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Outcome of revision hip arthroplasty in patients younger than 55 years: an analysis of 1,037 revisions in the Dutch Arthroplasty Register

Background and purpose - The increasing use of hip arthroplasties in young patients will inevitably lead to more revision procedures at younger ages, especially as the outcome of their primary procedures is inferior compared with older patients. However, data on the outcome of revision hip arthroplasty in young patients are limited. We determined the failure rates of revised hip prostheses performed in patients under 55 years using Dutch Arthroplasty Register (LROI) data.Patients and methods - All 1,037 revised hip arthroplasty procedures in patients under 55 years at the moment of revision registered in the LROI during the years 2007-2018 were included. Kaplan-Meier survival analyses were used to calculate failure rates of revised hip arthroplasties with endpoint re-revision for any reason. Competing risk analyses were used to determine the probability of re-revision for the endpoints infection, dislocation, acetabular and femoral loosening, while other reasons for revisions and death were considered as competing risks.Results - Mean follow-up of revision procedures was 3.9 years (0.1-12). 214 re-revisions were registered. The most common reason for the index revision was dislocation (20%); the most common reason for re-revision was infection (35%). The 5-year failure rate of revised hip prostheses was 22% (95% CI 19-25), and the 10-year failure rate was 28% (CI 24-33). The 10-year cumulative failure rates of index revisions with endpoint re-revision for infection was 7.8% (CI 6.1-9.7), acetabular loosening 7.0% (CI 4.1-11), dislocation 3.8% (CI 2.6-5.2), and femoral loosening 2.7% (CI 1.6-4.1). The 10-year implant failure rate of index revisions for infection was 45% (CI 37-55) with endpoint re-revision for any reason.Interpretation - Failure rate of revised hip prostheses in patients under 55 years is worrisome, especially regarding index revisions due to infection. This information facilitates realistic expectations for these young patients at the time of primary THA.

[Metallic Artifacts on MR Imaging and Methods for Their Reduction]

Metallic artifacts on MR imaging are typically induced by differences in magnetic susceptibility between the metallic implant and surrounding tissue. Conventional techniques for metal artifact reduction require MR machines with low field strength, shift in the frequency-encoding and phase-encoding directions according to the axis of metallic implant, increased receiver bandwidth and matrix, decreased slice thickness, and utilization of the short tau inversion recovery or Dixon method for fat-suppression. Slice-encoding for metal artifact correction and multi-acquisition variable-resonance image combination can dramatically reduce the number of metallic artifacts. However, these sequences have a considerably long acquisition time. Furthermore, the recently developed acceleration techniques including compressed sensing can solve this problem.

Is Spinal Anesthesia Safer than General Anesthesia for Patients Undergoing Revision THA? Analysis of the ACS-NSQIP Database

BACKGROUND

The incidence of revision THA continues to increase and there is a need to identify risk factors contributing to postoperative complications. Anesthesia type has been shown to be associated with complication rates in patients who undergo primary THA, but it is not clear whether the same is true among patients undergoing revision THA.

QUESTIONS/PURPOSES

(1) After controlling for confounding variables, in the setting of a large-database analysis, is spinal anesthesia associated with a lower risk of death, readmission, reoperation, postoperative transfusion, thromboembolic events, surgical site infection (SSI), and re-intubation among patients undergoing revision THA?

METHODS

The American College of Surgeons-National Surgical Quality Improvement (ACS-NSQIP) database was queried for patients undergoing aseptic, revision THA with either spinal or general anesthesia. Coarsened exact matching was used to match patients based on several baseline characteristics, including age, sex, body mass index, surgery type (Current Procedural Terminology code), and the modified Frailty Index score. Coarsened exact matching is a statistical method of exact matching that matches on chosen characteristics, in which continuous variables may be temporarily coarsened (such as, into discrete categorical variables) to facilitate matching. This method is an alternate to and requires less estimation than traditional propensity score matching. Then, using a model controlling for baseline patient characteristics and operative time, we performed multivariate logistic and linear regression analyses of matched cohorts to examine differences in mortality, readmission, reoperation, thromboembolic events, transfusion, SSI, and re-intubation.

RESULTS

After statistical matching and controlling for baseline demographic variables, surgery type (one- or two-component revision), surgical time and modified Frailty Index we found that patients receiving general anesthesia had higher odds of mortality (OR 3.72 [95% CI 1.31 to 10.50]; p = 0.013), readmission (OR 1.49 [95% CI 1.24 to 1.80]; p < 0.001), reoperation (OR 1.40 [95% CI 1.13 to 1.73]; p = 0.002), thromboembolic events (OR 2.57 [95% CI 1.37 to 4.84]; p = 0.003), SSI (OR 1.32 [95% CI 1.01 to 1.72]; p = 0.046), postoperative transfusion (OR 1.57 [95%CI 1.39 to 1.78]; p < 0.001) and unplanned intubation or failure to wean off intubation (OR 5.95 [95% CI 1.43 to 24.72]; p = 0.014).

CONCLUSIONS

In patients undergoing revision THA, spinal anesthesia is associated with a decreased risk of several complications. The current investigation suggests that, when practical (such as when long surgical times or changes to the surgical plan are not anticipated), spinal anesthesia should be considered for use during revision THA.

LEVEL OF EVIDENCE

Level III, therapeutic study.

General vs Spinal Anesthesia for Revision Total Knee Arthroplasty: Do Complication Rates Differ?

BACKGROUND

The incidence of both primary total knee arthroplasty (TKA) and revision TKA is increasing. Data from primary arthroplasty patients suggest a risk reduction with the use of spinal anesthesia when compared with general anesthesia. However, the same relationship has not been examined in the revision knee arthroplasty patient.

METHODS

This is a retrospective cohort study using the American College of Surgeons-National Surgical Quality Improvement database. Patients undergoing revision TKA with either spinal or general anesthesia were identified from the database. Baseline characteristics were compared, and ultimately patients were matched using coarsened exact matching. Multivariate analysis was then performed on matched cohorts controlling for baseline patient and operative characteristics. This model was used to look for any differences in rates of complications, operative time, length of stay, and readmission.

RESULTS

Patients undergoing revision TKA with general anesthesia had increased risk of several postoperative complications, even after controlling for baseline patient characteristics. Specifically, there were significantly increased rates of the following: unplanned readmission (OR = 1.43, 95% confidence interval [CI] = 1.18-1.72, P < .001), nonhome discharge (OR = 1.60, 95% CI = 1.46-1.76, P < .001), transfusion (OR = 1.63, 95% CI = 1.41-1.88, P < .001), deep surgical site infection (OR = 1.43, 95% CI = 1.01-2.03, P = .043), and extended length of stay (OR = 1.22, 95% CI = 1.11-1.34, P < .001). General anesthesia was additionally associated with increased operative time.

CONCLUSION

General anesthesia is associated with increased risk of numerous postoperative complications in patients undergoing revision TKA. This study is retrospective in nature, and while causality cannot be definitively determined, the results suggest that spinal anesthesia is preferential to general anesthesia in the revision TKA patient.

A comparative study of cortico-cancellous iliac bone graft with or without the combination of vascularized greater trochanter flap for the management of femoral head osteonecrosis: a minimum 6 years follow-up

BACKGROUND

To compare the mid-long-term clinical and radiological outcomes between a combination of cortico-cancellous iliac bone graft with vascularized greater trochanter flap (Group A) and isolate iliac bone graft (Group B) in the treatment of Osteonecrosis of the Femoral Head (ONFH).

METHODS

From January 2006 to December 2012, 123 patients (135 hips) who underwent abovementioned hip-preserving surgeries were included for analysis. Clinical outcomes were assessed based on Harris Hip Score (HHS) System and The Western Ontario and McMaster University Index (WOMAC) scores between the preoperative and the last follow-up. A series of postoperative X-rays were compared to preoperative images for radiological evaluation.

RESULTS

The HHS in Group A and B were enhanced from 50.57 ± 3.39 to 87.60 ± 4.15 and from 50.24 ± 3.30 to 85.18 ± 6.45, respectively, which both showed significance between preoperative and postoperative latest follow-up (p < 0.001). Group A revealed better improvement in terms of HHS (p = 0.017). The WOMAC total, postoperative stiffness, difficulty subscale scores in Group A showed better outcomes when compared to Group B (p < 0.01), while pain improvement between these two groups revealed no significance (p = 0.402). Besides, Group A suggested better necrotic region repair (p = 0.020), but no femoral head collapse difference in terms of Association Research Circulation Osseous classification change was found (p > 0.05).

CONCLUSIONS

A combination of cortico-cancellous iliac bone graft and concurrent vascularized greater trochanter flap with the lateral femoral circumflex transverse branch has been proved can obtain better functional and radiological results than isolate iliac bone grafting, which is attributed to blood reconstruction of the femoral head.