Patient-Specific Femoral Guide with 3-Dimensional Support Software in Anterolateral Supine Approach of Total Hip Arthroplasty: A Single-Arm Trial.

Currently, there is no surgical assistance system that can perform a three-dimensional (3D) planned total hip arthroplasty (THA) by methods other than surgical assistance navigation or robots. However, they are expensive, cumbersome, and subject to additional invasiveness, so there is a need for a simpler and less expensive 3D surgical support system. In this study, THA was performed using the anterolateral approach (Watson-Jones) in the supine position in 23 subjects to examine the efficacy and safety of a patient-specific femoral guide linked to 3D surgery support software. In 48% of the subjects, the difference in anterior torsion angle from the preoperative plan was within ±5 degrees, while in 83% of the subjects, the difference was within ±10 degrees. The 95% confidence interval (4.61-8.70) of the absolute difference did not fall below the pre-defined threshold of 7.2 degrees (p = 0.293). No adverse events were observed other than 2 cases (8.7%) of hemorrhage that required a blood transfusion. We confirmed the efficacy and safety of the patient-specific femoral guide in anterolateral supine approach THA.

A cross-sectional study evaluating patients' preferences for Salter innominate osteotomy.

BACKGROUND: Residual acetabular dysplasia in children after reduction of hip dislocation is often treated using Salter innominate osteotomy to prevent future osteoarthritis. Preventive surgery for asymptomatic patients, which could result in overtreatment, should be carefully applied with consideration of patients' opinions. In this study, we aimed to describe opinions on Salter innominate osteotomy as preventive surgery for children among adult patients who had undergone periacetabular osteotomy for hip pain due to hip dysplasia. METHODS: A mail-in questionnaire survey was conducted with 77 patients who underwent periacetabular osteotomy. Participants responded whether they would recommend Salter innominate osteotomy as preventive surgery for children and the reason for their opinion. We also performed a patient-based evaluation using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire and assessed clinical outcome measures with the Japanese Orthopedic Association score. Their recommendations and reasons were evaluated, and associations between their opinions and demographic and clinical characteristics were analyzed. RESULTS: Forty-three patients (56%) responded to the questionnaire. Of these, 10 (23%) patients recommended undergoing Salter innominate osteotomy, 28 (65%) patients did not, and 5 (12%) patients responded they were undecided. No significant association was observed between their opinions and demographic/clinical characteristics evaluated in the survey. The most frequent reason for why they do not recommend Salter innominate osteotomy was related to uncertainty about future hip pain. CONCLUSIONS: In total, 65% of the study participants did not recommend Salter innominate osteotomy for children with risk of dysplasia in the future. Participants' preferences regarding preventive surgery were not influenced by demographic and clinical characteristics.

CEFAZOLIN PROPHYLACTIC EFFICACY ON PROSTHETIC JOINT INFECTION AFTER PRIMARY HIP ARTHROPLASTY.

Objective: Perioperative deep prosthetic joint infection (PJI) is a serious postoperative complication of total hip arthroplasty (THA). We aimed to compare the efficacy of cefazolin administered within 24 and 48 h of primary THA for PJI prophylaxis. Methods: In this retrospective study, 720 patients were divided into two groups depending on whether cefazolin was administered as a single injection of 2 g twice daily within 24 (24-h group) or 48 h of surgery and the following day (48-h group). Sex, age at surgery, body mass index, co-existing diseases, blood test data, and PJI risk factors were evaluated. Results: The 24- and 48-h groups included 364 and 356 patients, respectively. Diabetes mellitus was the most common risk factor for PJI in both groups. The corresponding incidence of perioperative deep PJI following primary THA was 0.55% and 0.28% in the 24- and 48-h groups, respectively. There was no significant difference in patient background characteristics between the groups. Conclusions: Cefazolin administration within 24 h of primary THA may be appropriate for perioperative deep PJI. Level of Evidence II; Retrospective study .

Objetivo: A infecção de prótese articular (IPA) perioperatória profunda é uma grave complicação pós-operatória da artroplastia total de quadril (ATQ). Este estudo buscou comparar a eficácia da cefazolina administrada dentro de 24 e 48 horas após ATQ para profilaxia de IPA. Métodos: Neste estudo retrospectivo, 720 pacientes foram divididos em dois grupos, que receberam cefazolina em uma injeção de 2g duas vezes por dia nas primeiras 24 e 48 horas (grupos de 24 e 48 horas), respectivamente. Foram avaliados sexo, idade na data da cirurgia, índice de massa corporal, comorbidades, testes sanguíneos e fatores de risco para IPA. Resultados: Os grupos de 24 e 48 horas incluíram, respectivamente, 364 e 356 pacientes. O fator de risco para IPA mais comum nos dois grupos foi o diabetes mellitus. A incidência de IPA perioperatória profunda após ATQ foi, respectivamente, de 0,55% e 0,28% nos grupos de 24 e 48 horas. Não houve diferença significativa nas características gerais dos pacientes entre os dois grupos. Conclusão: A administração de cefazolina dentro de 24 horas após ATQ primária pode ser adequada para IPA perioperatória profunda. Nível de Evidência II; Estudo retrospectivo .

Three-dimensional foot trajectory in female patients with end-stage hip osteoarthritis during walking.

Osteoarthritis (OA) is a risk factor for falls. To decrease the fall risk, it is important to evaluate the detailed features of the gait of patients with OA. This study aimed to investigate the spatio-temporal parameters of gait in patients with end-stage hip OA, especially foot trajectory. We measured normal speed gait in patients with hip OA and in healthy controls (HCs) using inertial measurement units attached to shanks. The stride lengths in the affected and unaffected sides in the patients with hip OA were shorter than those in the HCs, but the position of maximum foot clearance was not significantly different between the two groups. The patients with hip OA compensated the position of maximum foot clearance to avoid fall risk. The horizontal plane foot trajectory in patients with hip OA suggests that the lateral bending of the trunk during walking, which is frequently seen in them, was a result of the lateral distance at swing down being located significantly more medially on the unaffected side than on the affected side. Herein, a new gait parameter of lateral distance at swing was discovered by a detailed evaluation of three-dimensional foot trajectory of female patients with end-stage hip OA.

Cefazolin prophylactic efficacy on prosthetic joint infection after primary hip arthroplasty / Eficácia profilática da cefazolina sobre a infecção protética articular após artroplastia primária de quadril

ABSTRACT Objective Perioperative deep prosthetic joint infection (PJI) is a serious postoperative complication of total hip arthroplasty (THA). We aimed to compare the efficacy of cefazolin administered within 24 and 48 h of primary THA for PJI prophylaxis. Methods In this retrospective study, 720 patients were divided into two groups depending on whether cefazolin was administered as a single injection of 2 g twice daily within 24 (24-h group) or 48 h of surgery and the following day (48-h group). Sex, age at surgery, body mass index, co-existing diseases, blood test data, and PJI risk factors were evaluated. Results The 24- and 48-h groups included 364 and 356 patients, respectively. Diabetes mellitus was the most common risk factor for PJI in both groups. The corresponding incidence of perioperative deep PJI following primary THA was 0.55% and 0.28% in the 24- and 48-h groups, respectively. There was no significant difference in patient background characteristics between the groups. Conclusions Cefazolin administration within 24 h of primary THA may be appropriate for perioperative deep PJI. Level of Evidence II; Retrospective study.

RESUMO Objetivo A infecção de prótese articular (IPA) perioperatória profunda é uma grave complicação pós-operatória da artroplastia total de quadril (ATQ). Este estudo buscou comparar a eficácia da cefazolina administrada dentro de 24 e 48 horas após ATQ para profilaxia de IPA. Métodos Neste estudo retrospectivo, 720 pacientes foram divididos em dois grupos, que receberam cefazolina em uma injeção de 2g duas vezes por dia nas primeiras 24 e 48 horas (grupos de 24 e 48 horas), respectivamente. Foram avaliados sexo, idade na data da cirurgia, índice de massa corporal, comorbidades, testes sanguíneos e fatores de risco para IPA. Resultados Os grupos de 24 e 48 horas incluíram, respectivamente, 364 e 356 pacientes. O fator de risco para IPA mais comum nos dois grupos foi o diabetes mellitus. A incidência de IPA perioperatória profunda após ATQ foi, respectivamente, de 0,55% e 0,28% nos grupos de 24 e 48 horas. Não houve diferença significativa nas características gerais dos pacientes entre os dois grupos. Conclusão A administração de cefazolina dentro de 24 horas após ATQ primária pode ser adequada para IPA perioperatória profunda. Nível de Evidência II; Estudo retrospectivo.

SugarDrawer: A Web-Based Database Search Tool with Editing Glycan Structures.

In life science fields, database integration is progressing and contributing to collaboration between different research fields, including the glycosciences. The integration of glycan databases has greatly progressed collaboration worldwide with the development of the international glycan structure repository, GlyTouCan. This trend has increased the need for a tool by which researchers in various fields can easily search glycan structures from integrated databases. We have developed a web-based glycan structure search tool, SugarDrawer, which supports the depiction of glycans including ambiguity, such as glycan fragments which contain underdetermined linkages, and a database search for glycans drawn on the canvas. This tool provides an easy editing feature for various glycan structures in just a few steps using template structures and pop-up windows which allow users to select specific information for each structure element. This tool has a unique feature for selecting possible attachment sites, which is defined in the Symbol Nomenclature for Glycans (SNFG). In addition, this tool can input and output glycans in WURCS and GlycoCT formats, which are the most commonly-used text formats for glycan structures.

Tension-band wiring of displaced stable olecranon fractures with Eyelet-pins in the elderly: A series of 17 cases.

BACKGROUND: Tension-band wiring (TBW) and plate fixation are commonly used to fix displaced olecranon fractures. However, the high incidence of complications in the elderly, such as wound breakdown, infection, and loss of reduction, remain a concern for orthopaedic surgeons. Furthermore, patients frequently suffer from removal of the hardware. Even so, the operation seems to be indicated for independent elderly patients to return to their former activities of daily living. HYPOTHESIS: TBW of displaced stable olecranon fractures with Eyelet-pins in the independent elderly reduce the incidence of complications and allow early elbow joint exercise to keep their former activities. PATIENTS AND METHODS: We operated on the displaced stable olecranon fractures of 17 independent patients aged ≥ 70 using TBW with two Eyelet-pins. Eyelet-pins have an eyelet at the trailing end to prevent pin migration by passing a soft wire through it. The patients were reviewed clinically and radiologically at 2, 6, 12, and 24 weeks, and clinically at 1 year after the surgery. RESULTS: All fractures were united within 12 weeks, and the anatomic reduction was maintained. Mean radiographic proximal migration of the Eyelet-pins was 0.4mm (0.1 ∼ 1.2mm). Mean active elbow flexion was 136° (115° ∼ 145°) and extension 6.2° (0° ∼ 30°). Two patients had mild local pain and pain on motion at the tip of the eyelet. No patient required removal of the hardware. Other complications, such as superficial or deep wound infections, and neurological symptoms or signs, were not seen. All patients were able to maintain their former activities of daily living. CONCLUSION: TBW with Eyelet-pins for displaced stable olecranon fractures is useful for independent elderly patients to reduce the incidence of complications and to maintain their former activities of daily living without removal of the hardware. LEVEL OF EVIDENCE: IV; single-centre retrospective study.

Efficacy and safety of tedizolid in a patient with linezolid-induced neutropenia: A case report.

Linezolid is used to treat prosthetic joint infection after total hip arthroplasty. Here, we present a case of linezolid-induced severe neutropenia, which improved after switching to tedizolid. Grade 3 neutropenia developed 5 days after linezolid injection (1,200 mg/day) and 33 days after oral administration of the same dose. However, during the 70 days of treatment with tedizolid, grade 3 neutropenia did not occur, and C-reactive protein levels remained in the normal range. No grade ≥ 1 thrombocytopenia or bleeding event occurred during the course of tedizolid treatment. Tedizolid may be an alternative drug for patients who develop linezolid-induced neutropenia.

Enhanced validation of small-molecule ligands and carbohydrates in the Protein Data Bank.

The Worldwide Protein Data Bank (wwPDB) has provided validation reports based on recommendations from community Validation Task Forces for structures in the PDB since 2013. To further enhance validation of small molecules as recommended from the 2016 Ligand Validation Workshop, wwPDB, Global Phasing Ltd., and the Noguchi Institute, recently formed a public/private partnership to incorporate some of their software tools into the wwPDB validation package. Augmented wwPDB validation report features include: two-dimensional (2D) diagrams of small-molecule ligands and carbohydrates, highlighting geometric validation outcomes; 2D topological diagrams of oligosaccharides present in branched entities generated using 2D Symbol Nomenclature for Glycan representation; and views of 3D electron density maps for ligands and carbohydrates, illustrating the goodness-of-fit between the atomic structure and experimental data (X-ray crystallographic structures only). These improvements will impact confidence in ligand conformation and ligand-macromolecular interactions that will aid in understanding biochemical function and contribute to small-molecule drug discovery.

Bone morphology of the proximal femoral canal: ethnicity related differences and the influence on cementless tapered wedge stem designs.

BACKGROUND: Differences in proximal femoral morphology between ethnicities may have implications on the design of cementless tapered wedge stems. This study analyses the differences in Asian and Caucasian bone morphology as well as the related fit of various cementless tapered wedge stem designs. METHODS: A computed tomography database and modelling software was used to retrospectively analyse a total of 1345 femora. Ethnicity related comparisons as well as the fit of the stem designs were analysed. RESULTS: Statistically significant differences between canal shape of Caucasian and Japanese as well as non-Japanese Asians were observed. The fit of the stems within the femoral canal was highly dependent on the respective stem shape. CONCLUSIONS: The shape differences in stem designs had a larger influence on the fit within the femoral canal than the differences in ethnicity related to bone morphology.

The international glycan repository GlyTouCan version 3.0.

Glycans serve important roles in signaling events and cell-cell communication, and they are recognized by lectins, viruses and bacteria, playing a variety of roles in many biological processes. However, there was no system to organize the plethora of glycan-related data in the literature. Thus GlyTouCan (https://glytoucan.org) was developed as the international glycan repository, allowing researchers to assign accession numbers to glycans. This also aided in the integration of glycan data across various databases. GlyTouCan assigns accession numbers to glycans which are defined as sets of monosaccharides, which may or may not be characterized with linkage information. GlyTouCan was developed to be able to recognize any level of ambiguity in glycans and uniquely assign accession numbers to each of them, regardless of the input text format. In this manuscript, we describe the latest update to GlyTouCan in version 3.0, its usage, and plans for future development.

Mass Spectrometric Method for the Unambiguous Profiling of Cellular Dynamic Glycosylation.

Various biological processes at the cellular level are regulated by glycosylation which is a highly microheterogeneous post-translational modification (PTM) on proteins and lipids. The dynamic nature of glycosylation can be studied through metabolic incorporation of non-natural sugars into glycan epitopes and their detection using bio-orthogonal probes. However, this approach possesses a significant drawback due to nonspecific background reactions and ambiguity of non-natural sugar metabolism. Here, we report a probe-free strategy for their direct detection by glycoproteomics and glycomics using mass spectrometry (MS). The method dramatically simplifies the detection of non-natural functional group bearing monosaccharides installed through promiscuous sialic acid, N-acetyl-d-galactosamine (GalNAc) and N-acetyl-d-glucosamine (GlcNAc) biosynthetic pathways. Multistage enrichment of glycoproteins by cellular fractionation, subsequent ZIC-HILIC (zwitterionic-hydrophilic interaction chromatography) based glycopeptide enrichment, and a spectral enrichment algorithm for the MS data processing enabled direct detection of non-natural monosaccharides that are incorporated at low abundance on the N/O-glycopeptides along with their natural counterparts. Our approach allowed the detection of both natural and non-natural sugar bearing glycopeptides, N- and O-glycopeptides, differentiation of non-natural monosaccharide types on the glycans and also their incorporation efficiency through quantitation. Through this, we could deduce interconversion of monosaccharides during their processing through glycan salvage pathway and subsequent incorporation into glycan chains. The study of glycosylation dynamics through this method can be conducted in high throughput, as few sample processing steps are involved, enabling understanding of glycosylation dynamics under various external stimuli and thereby could bolster the use of metabolic glycan engineering in glycosylation functional studies.

Long-term assessment of morphological, functional, and quantitative parameters of skeletal muscle in older patients after unilateral total hip arthroplasty.

Total hip arthroplasty (THA) is performed for pain relief in patients with osteoarthritis of the hip joint. After THA, patients may recover muscle mass and physical function. Muscle quality is the main parameter used to indicate intramuscular fat content, and it is related with muscle function in older individuals. However, how THA affects muscle quality, as determined by echo intensity (EI), is not well understood. The purpose of this study was to determine the long-term characteristics of EI, muscle quantity, muscle function, and physical functions in the patients with THA surgery. In order to achieve the purpose, we performed two comparison. First, we compared muscle EI, quantity and function in operated leg with unoperated legs in the same patients and with the legs of healthy adults (i.e., both unoperated legs). Second, we compared physical functional tests between THA patient and age and body composition matched controls. Twenty-two older individuals (age: 67.1 ± 5.3 years, height: 160.9 ± 7.1 cm, body mass: 62.6 ± 16.1 kg) who underwent unilateral THA several (5.2 ± 3.1) years ago (THA group) and 22 healthy controls with matching age and body composition (age: 68.3 ± 4.4 years, height: 160.3 ± 7.9 cm, body mass: 61.7 ± 7.8 kg) (CON group) participated in this case-control study. EI, an index of muscle quality, and muscle thickness (MT), an index of muscle quantity, were measured from B-mode transverse images of the rectus femoris obtained through ultrasound. The maximal isometric knee extension torque was measured in both the operated and unoperated legs in the THA group and in the right leg in the CON group (control leg); physical function tests, such as sit-to-stand, walking speed, hip adduction, and abduction torque assessments, were performed in both groups. MT and maximal isometric knee extension torque in operated leg were not different with unoperated, and control legs; the EI in the operated leg was significantly higher than that in the control leg (106.9 ± 16.9 vs. 92.4 ± 21.0 a.u., P < 0.05). The THA group demonstrated slower walking speed and lower hip abduction torque than the CON group (walking speed: 1.3 ± 0.2 vs. 1.5 ± 0.2 m/s; hip abduction torque 1.2 ± 0.3 vs. 1.5 ± 0.5 Nm/kg, P < 0.05). Several years after THA, the operated legs completely recovered the same level of muscle quantity as that in healthy participants but with lower muscle quality and hip joint function. These defects may be associated with locomotive dysfunction in older THA patients.

BioHackathon 2015: Semantics of data for life sciences and reproducible research.

We report on the activities of the 2015 edition of the BioHackathon, an annual event that brings together researchers and developers from around the world to develop tools and technologies that promote the reusability of biological data. We discuss issues surrounding the representation, publication, integration, mining and reuse of biological data and metadata across a wide range of biomedical data types of relevance for the life sciences, including chemistry, genotypes and phenotypes, orthology and phylogeny, proteomics, genomics, glycomics, and metabolomics. We describe our progress to address ongoing challenges to the reusability and reproducibility of research results, and identify outstanding issues that continue to impede the progress of bioinformatics research. We share our perspective on the state of the art, continued challenges, and goals for future research and development for the life sciences Semantic Web.

Detection of total hip prostheses at airport security checkpoints.

BACKGROUND: There have been several reports regarding airport security checks using arched metal detectors in patients with orthopedic implants and/or joint replacement surgery. Implants of different sizes and/or materials are used in total hip arthroplasty (THA), but there have been no reports regarding differences in detection rates between different types of THA implants and materials. We examined detection rates by airport metal detectors among THA patients with different implants. METHODS: We selected 1684 patients from regular outpatients at our hospital from June to December 2016. A questionnaire elicited responses regarding usage of airplanes, flight type (domestic/international), and detection by airport metal detectors. Data were investigated according to unilateral/bilateral THA, femoral stem type, acetabular shell component diameter, femoral head diameter, and femoral head material type. RESULTS: Among 671 patients selected from those who used airplanes, 346 patients reported detection by metal detectors. Detection rates for patients with unilateral THA/domestic flights, unilateral THA/international flights, bilateral THA/domestic flights, and bilateral THA/international flights were 23% (81 of 351 patients), 56% (114 of 186 patients), 75% (140 of 204 patients), and 86% (118 of 138 patients), respectively. Logistic regression analysis indicated that the most effective explanatory variables were cup size and material type of femoral head for domestic flights, and cup size for unilateral THA/international flights. CONCLUSION: Detection rate was lowest for patients with unilateral THA/domestic flights (23%), and highest for bilateral THA/international flights (86%). Statistical analyses of implant data indicated that cup size was the most significant explanatory variable.

Does An Augmented Reality-based Portable Navigation System Improve the Accuracy of Acetabular Component Orientation During THA? A Randomized Controlled Trial.

BACKGROUND: We developed an augmented reality (AR)-based portable navigation system in which the surgeon can view the pelvic plane and placement angle of an acetabular cup on the display of a smartphone during THA. QUESTIONS/PURPOSES: (1) Is acetabular component placement more accurate using the AR-based portable navigation system compared with the conventional freehand technique? (2) Is intraoperative measurement of placement angle more accurate when using the AR-based portable navigation system compared with a goniometer? METHODS: Forty-six patients were randomly assigned to undergo acetabular cup placement during THA using the AR-based portable navigation system (AR navigation group) or placement of a mechanical alignment guide (conventional group). All surgeries were performed with the patient in the lateral decubitus position. We compared the absolute value of the difference between the targeted placement angle and postoperative measured placement angle between the groups using two types of imaging (radiography and CT). RESULTS: In terms of radiographic inclination, the mean differences between the targeted placement angle and postoperative measured angle were smaller in the AR navigation group than in the conventional group for both radiographs and CT images (2.3° ± 1.4° versus 3.9° ± 2.4°, respectively; p = 0.009 and 1.9° ± 1.3° versus 3.4° ± 2.6°, respectively; p = 0.02). There were no differences in radiographic anteversion between the two groups. No complications were associated with the use of the AR-based portable navigation system. CONCLUSIONS: This system yielded no differences in acetabular anteversion accuracy, and no clinically important differences in acetabular inclination. Therefore, at this time we cannot recommend this device as its costs and risks cannot be justified based on the absence of a clinically meaningful difference in cup placement accuracy. Although we detected no complications, this was a small series, and this approach adds both surgical time and pins in the ilium. LEVEL OF EVIDENCE: Level I, therapeutic study.

Midterm Outcomes and Frequency of Osteolysis of Total Hip Arthroplasty Using Cementless Modular Stem for Asian Patients.

BACKGROUND: Modular stems are useful for total hip arthroplasty (THA) in anatomically difficult dysplasia. Here, we present mean 6.8-year outcomes of cementless primary THA using S-ROM-A (modified modular stem for Asian patients) femoral prosthesis in anatomically difficult cases. METHODS: Charts of 373 patients (461 hips) undergoing THA (mean age, 58 years) were reviewed for clinical evaluation of modified Merle d'Aubigné-Postel score and Kaplan-Meier survivorship with revision for any reason as the end point. For radiographic analysis, 331 patients (412 hips) followed up for ≥5 years were included. Bearing couples were metal-on-metal (n = 145), metal-on-polyethylene (n = 120), and ceramic-on-polyethylene (n = 147). Radiography and multiplanar computed tomography were performed. RESULTS: No postoperative dislocation or deep infection occurred. Mean modified Merle d'Aubigné-Postel score improved significantly (10.9 points preoperatively, 16.7 points at last follow-up; P < .001). Cumulative 5- and 10-year stem survival rates were 100% and 84%, respectively (95% confidence interval, 75%-93%). All stems were classified as bone ingrown fixation. Osteolysis occurred in metal-on-metal (42.8%) and metal-on-polyethylene (15.8%) groups. Mean time to osteolysis was ~3 years, with no significant difference between 3 groups (P = .264). In logistic regression, lower cup inclination angle was significantly associated with osteolysis (odds ratio, 0.914; 95% confidence interval, 0.84-0.99; P = .029). CONCLUSION: S-ROM-A femoral prosthesis achieved excellent midterm fixation, and the modular system was useful in primary THA with severe deformity. Bearing couples are potentially associated with adverse reactions to metal debris. S-ROM-A with ceramic-on-polyethylene bearing couples may be an option for anatomically difficult THA.

No Clinically Important Difference in Pain Scores After THA Between Periarticular Analgesic Injection and Placebo: A Randomized Trial.

BACKGROUND: Periarticular analgesic injection (PAI) is being used more commonly for pain relief after orthopaedic surgeries. However, there is conflicting evidence regarding the effectiveness of PAI for post-THA pain relief. QUESTIONS/PURPOSES: In a double-blind, randomized, controlled trial among patients undergoing same-day bilateral THA, with each patient serving as his or her own control, we asked: (1) Did the pain score as measured on a 100-mm VAS differ between the hips that received PAI versus placebo? (2) Were there differences in complications between the treatment and control hips in these patients? METHODS: Over a 1-year period at one center, 45 patients underwent same-day bilateral THA; three were excluded for prespecified reasons, and two declined participation in this randomized, controlled trial, leaving 40 patients (80 THAs) in the study. Patients randomly received PAI in one hip and placebo in the contralateral hip; patients, surgeons, and nurses were blinded in terms of which hip received the PAI and which hip received a placebo saline injection. The PAI solution included ropivacaine, morphine hydrochloride hydrate, methylprednisolone, ketoprofen, and epinephrine. The primary outcome was the VAS for pain at rest 24 hours after THA, measured using a 100-mm horizontal VAS. The VAS score was compared between two groups and assessed to reach the reported threshold values for the minimum clinically important difference (MCID) of 20 mm for the postoperative VAS score. No patients were lost to followup, and there were no missing data for the primary outcome. Complications that occurred during the trial were recorded prospectively with emphasis on infection, wound complications, nerve palsy and allergic reactions to the injections. RESULTS: There were no clinically important differences between hips treated with the PAI and those treated with the placebo injection at any point. The hips that received PAI had less pain than those receiving placebo 24 hours after THA (16 ± 17 mm versus 22 ± 20 mm; mean difference, 6 mm; 95% confidence interval [CI], 2-9 mm; p = 0.006), but this effect size was below the MCID of 20 mm and thus is unlikely to be clinically important. The hips that received PAI also had better VAS scores in the recovery room (38 ± 29 mm versus 52 ± 33 mm; mean difference 14 mm; 95% CI, 5-23 mm; p = 0.004) and 3 hours after THA than placebo controls (28 ± 22 mm versus 37 ± 24 mm; mean difference 9 mm; 95% CI, 2-16 mm; p = 0.010). Neither of these differences exceeded the MCID and likewise were unlikely to be clinically important. No complications, including surgical site infections, were observed in either group. CONCLUSIONS: Periarticular analgesic injection for pain control after THA did not result in a clinically important reduction in pain at any point examined. Given the expense associated with this PAI mixture and the lack of effectiveness outside this timeframe, we cannot recommend its use. Other mixtures or concentrations of drugs may be helpful in short-stay admissions for THA, but this will require further research. LEVEL OF EVIDENCE: Level I, therapeutic study.

A Pilot Study of Augmented Reality Technology Applied to the Acetabular Cup Placement During Total Hip Arthroplasty.

BACKGROUND: We developed an acetabular cup placement device, the AR-HIP system, using augmented reality (AR). The AR-HIP system allows the surgeon to view an acetabular cup image superimposed in the surgical field through a smartphone. The smartphone also shows the placement angle of the acetabular cup. This preliminary study was performed to assess the accuracy of the AR-HIP system for acetabular cup placement during total hip arthroplasty (THA). METHODS: We prospectively measured the placement angles using both a goniometer and AR-HIP system in 56 hips of 54 patients undergoing primary THA. We randomly determined the order of intraoperative measurement using the 2 devices. At 3 months after THA, the placement angle of the acetabular cup was measured on computed tomography images. The primary outcome was the absolute value of the difference between intraoperative and postoperative computed tomography measurements. RESULTS: The measurement angle using AR-HIP was significantly more accurate in terms of radiographic anteversion than that using a goniometer (2.7° vs 6.8°, respectively; mean difference 4.1°; 95% confidence interval, 3.0-5.2; P < .0001). There was no statistically significant difference in terms of radiographic inclination (2.1° vs 2.6°; mean difference 0.5°; 95% confidence interval, -1.1 to 0.1; P = .13). CONCLUSION: In this pilot study, the AR-HIP system provided more accurate information regarding acetabular cup placement angle than the conventional method. Further studies are required to confirm the utility of the AR-HIP system as a navigation tool.