Neighborhood Socioeconomic Disadvantages Associated With Prolonged Lengths of Stay, Nonhome Discharges, and 90-Day Readmissions After Total Knee Arthroplasty.

BACKGROUND: Low socioeconomic status and neighborhood context has been linked to poor health care outcomes after total knee arthroplasty (TKA). The area deprivation index (ADI) addresses this relationship by ranking neighborhoods by socioeconomic disadvantage. We examined the following relationships of the ADI among TKA recipients: (1) patient demographics, (2) lengths of stay (LOS), (3) nonhome discharges, and (4) 90-day readmissions, emergency department visits, and reoperations. METHODS: We reviewed a consecutive series of primary TKAs from 2018 through 2020 at a tertiary health care system. A total of 3928 patients who had complete ADI data were included. A plurality of patients (14.9%) were categorized within ADI 31-40, below the national median ADI of 47. Associations between the national ADI decile and 90-day postoperative health care utilization metrics were evaluated using multivariate regressions (adjusted for patient demographics and comorbidities). RESULTS: The 91-100 ADI cohort was disproportionately African American, female, younger, and smokers. Compared with ADI 31-40 (reference), the ADI 61-70 cohort was associated with higher odds of LOS ≥3 days (odds ratio [OR] = 1.6 [1.08-2.36], P = .019) and nonhome discharges (OR = 1.73 [1.08-2.75], P = .021). The ADI 91-100 cohort was associated with the highest odds of prolonged LOS (OR = 2.27; [1.47-3.49], P < .001), nonhome discharges (OR = 3.49 [2.11-5.78], P < .001), and all-cause readmissions (OR: 1.79, [1.02-3.14], P = .044). No significant associations were found between the ADI and 90-day emergency department visits or reoperations (P > .05). CONCLUSION: A higher ADI was associated with prolonged LOS, nonhome discharge status, and 90-day readmissions after TKA. This index highlights potential areas of intervention for assessing health care outcomes.

Treatment with posterior capsular release, botulinum toxin injection, hamstring tenotomy, and peroneal nerve decompression improves flexion contracture after total knee arthroplasty: minimum 2-year follow-up.

PURPOSE: No definite treatment option with reasonable outcome has been presented for old and refractory flexion contracture after total knee arthroplasty (TKA). We describe a surgical technique for 21 refractory cases of knee flexion contracture, including 12 patients with history of failed manipulation under anesthesia (MUA). METHODS: Retrospective review was conducted for procedures performed by a single surgeon between 2005 and 2016. Twenty-one knees (19 patients) with knee flexion contracture after primary TKA were treated with all the following procedures: posterior capsular release, hamstring tenotomy, prophylactic peroneal nerve decompression, and botulinum toxin type A injections. Twelve of the 21 knees had at least 1 prior unsuccessful MUA before this soft-tissue release procedure. Mean age at intervention was 60 years (range 46-78 years). Mean preoperative knee range of motion (ROM) was - 27° extension (range - 20° to - 40°) to 100° flexion (range 90°-115°). All radiographs were evaluated for proper component sizing and signs of loosening. RESULTS: Full extension was achieved immediately after surgery in all patients. Only one knee required repeat botulinum toxin type A injection. All patients had full extension at mean follow-up of 31 months (range 24-49 months). No significant change was observed in knee flexion after the procedure (n.s.). Significant improvement was noted in the postoperative Knee Society Score (KSS) (mean 80, range 70-90) when compared with preoperative KSS (mean 45, range 25-65) (p = 0.008). CONCLUSION: The proposed surgical technique is efficacious in treating patients with refractory knee flexion contracture following TKA to gain and maintain full extension at minimum 2-year follow-up. LEVEL OF EVIDENCE: IV, retrospective case series.

Parkinson's disease increases the risk of perioperative complications after total knee arthroplasty: a nationwide database study.

PURPOSE: Therefore, the purpose of this study was to evaluate the short-term perioperative outcomes of PD patients who underwent total knee arthroplasty (TKA). We specifically evaluated: (1) perioperative surgical and medical complications; (2) lengths of stay (LOS); and (3) total hospital charges. METHODS: The Nationwide Inpatient Sample was used to identify PD patients who underwent TKA between 2002 and 2013. To control for potential confounders, PD TKA and non-PD TKA patients were propensity score matched (1:3) based on age, sex, ethnicity, Charlson Comorbidity Index, and insurance type. A total of 31,979 PD and 95,596 non-PD TKA patients were included. RESULTS: PD patients had a 44% higher risk of suffering from any complication (OR 1.44; 95% CI 1.35-1.54), a 45% increased risk for any medical complication (OR 1.45; 95% CI 1.36-1.55), and a 9% higher risk for any surgical complication (OR 1.09; 95% CI 0.84-1.41). Compared to the matched cohort, PD patients had a mean LOS that was 6.5% longer (95% CI 5.46-7.54) and mean total hospital charges that were 3.05% higher (95% CI 1.99-4.11). CONCLUSIONS: PD patients are more likely to have postoperative complications, longer LOS, and higher costs after TKA than non-PD TKA patients. Since many of these complications can be prevented, a team-based multi-specialty patient optimization is needed. LEVEL OF EVIDENCE: Level III, therapeutic study.

Revision Analysis of Robotic Arm-Assisted and Manual Unicompartmental Knee Arthroplasty.

BACKGROUND: The purpose of this study was to evaluate hospital admissions for revision surgeries associated with robotic arm-assisted unicompartmental knee arthroplasty (rUKA) vs manually instrumented UKA (mUKA) procedures. METHODS: Patients ≥18 years of age who received either a mUKA or a rUKA procedure were candidates for inclusion and were identified by the presence of appropriate billing codes. Procedures performed between March 1, 2013 and July 31, 2015 were used to calculate the rate of surgical revisions occurring within 24-months of the index procedure. Following propensity matching, 246 rUKA and 492 mUKA patients were included. Revision rates and the associated costs were compared between the two cohorts. The Mann-Whitney U test was used to compare continuous variables, and Fisher's exact tests was used to analyze discrete categorical variables. RESULTS: At 24 months after the primary UKA procedure, patients who underwent rUKA had fewer revision procedures (0.81% [2/246] vs 5.28% [26/492]; P = .002), shorter mean length of stay (2.00 vs 2.33 days; P > .05), and incurred lower mean costs for the index stay plus revisions ($26,001 vs $27,915; P > .05) than mUKA patients. Length of stay at index and index costs were also lower for rUKA patients (1.77 vs 2.02 days; P = .0047) and ($25,786 vs $26,307; P > .05). CONCLUSIONS: The study results demonstrate that patients who underwent rUKA had fewer revision procedures, shorter length of stay, and incurred lower mean costs (although not statistically different) during the index admission and at 24 months postoperatively. These results could be important for payers as the prevalence of end-stage knee osteoarthritis increases alongside the demand for cost-efficient treatments.

The Effect of Body Mass Index on 30-day Complications After Revision Total Hip and Knee Arthroplasty.

BACKGROUND: We aimed to explore the effect of body mass index (BMI) on 30-day complications after aseptic revision total knee arthroplasty (rTKA) and aseptic revision total hip arthroplasty (rTHA), considering BMI as both a categorical and continuous variable. METHODS: A total of 18,866 patients (9093 rTHA and 9773 rTKA) patients were included for analysis using the American College of Surgeons National Surgical Quality Improvement Project database. Thirty-day rates of readmissions, reoperations, and major and minor complications were compared between different weight categories (overweight: BMI >25 and ≤30 kg/m2; obese: BMI >30 and ≤40 kg/m2; morbidly obese: BMI >40 kg/m2) and the normal weight category (BMI >18.5 and ≤25 kg/m2) using multivariate regression models. Spline regression models were created to study BMI as a continuous variable. RESULTS: Both readmission rates and reoperation rates increased for rTKA as BMI increased (P < .005). There was a linear relationship between BMI and readmission rates for rTKA. Morbid obesity was associated with an increased reoperation rate for rTHA on univariate analysis (P = .022); however, multivariate analysis showed no statistically significant increase in readmission or reoperation rates as BMI increased for rTHA. CONCLUSIONS: The relationship between BMI and complications after revision total joint arthroplasty is a J-shaped curve with the lowest rates of complications occurring around a BMI of 30 kg/m2. The relationship between BMI and perioperative complications is stronger for revision TKA as opposed to revision THA.

The Association Between Operative Time and Short-Term Complications in Total Hip Arthroplasty: An Analysis of 89,802 Surgeries.

BACKGROUND: It has been established by previous studies that longer operative times can lead to higher rates of complications and poorer outcomes after total hip arthroplasty (THA). However, these studies were heterogeneous, examined limited complications, and have not provided a clear time after which complications increase. The aims of this study were to (1) assess whether longer operative time increases risk of complications within 30 days of THA, (2) investigate the relationship between operative time and various complications after THA, and (3) identify possible operative times beyond which complication rates increase. METHODS: The National Surgical Quality Improvement Project database was queried to identify 89,802 procedures that were included in the final analysis. The effect of operative time on complications within 30 days was evaluated using multivariate logistic regression models. Spline regression models were created to investigate the relationship between operative time and complications. RESULTS: Longer operative times were associated with higher risk of readmissions (P < .001), reoperations (P < .001), surgical site infection (P < .001), wound dehiscence (P < .001), renal or systemic complications (P < .001), and blood transfusion (P < .001). A linear relationship was observed between operative time and readmission, reoperation, surgical site infection, and transfusions with increased rate of these complications when the operative time exceeded 75 to 80 minutes. Venous thromboembolic complications had a U-shaped relationship with operative time with the trough around 90 to 100 minutes. CONCLUSION: While our findings cannot establish a clear cause and effect relation, they do suggest strong correlation between increased operative time and perioperative complications. Additionally, this study suggests an optimal time of approximately 80 minutes, as a goal for surgeons, that may be associated with less risk of complications following THA.

Outcomes of Dual Mobility Acetabular Cups in Total Hip Arthroplasty Patients.

BACKGROUND: Instability can account for over 20% of all revision total hip arthroplasties (THAs). Although a number of surgical techniques have been developed to limit the number of dislocations, prevention still remains a challenge. More recently, dual mobility (DM) cups have been developed to potentially target this problem. Although this implant design has been shown to have a number of potential advantages in the revision setting, there is limited data in the literature on the use of modular dual mobility (MDM) implants for primary THAs. Therefore, the purpose of this study was to evaluate cup survivorships, patient satisfaction outcomes, and complications of this device used for primary THA. MATERIALS AND METHODS: A total of 143 consecutive hips (131 patients) who underwent primary THA using DM prostheses by a high-volume academic surgeon were longitudinally followed up for a minimum of five years (mean: 6 years, 11 months; range, 6 years 3 months to 7 years 5 months). There were 77 women (54%) and 66 men (44%) who had a mean age 65 years (range, 34 to 90 years; SD, 11 years), and the mean body mass index (BMI) was 32 kg/m2 (range, 22 to 52; SD, 8 kg/m2). Patient demographics, (gender, BMI), as well as clinical outcomes were analyzed. Kaplan-Meier analysis was performed to determine aseptic, septic, and all-cause cup survivorship. Additionally, clinical outcomes based on Harris Hip Scores (HHS) and other modalities, as well as complications, were tabulated. Institutional review board (IRB) approval was received prior to initiating this study. RESULTS: Septic survivorship was found to be 99.3% (95% CI: 0.98 to 1.0), while all-cause survivorship was 98.6% (95% CI: 0.97 to 1.0). There were a total of two revision surgeries; however, these were not related to the MDM cup. Specifically, one patient had femoral stem loosening, while another patient had a late deep infection treated with a two-stage procedure. At most recent follow up, both patients were progressing well and had HHS scores of 85 and 92 points. The mean total HHS score was 95 points (range, 64 to 100) at most recent follow up. Other complications affecting patient outcomes included two patients who presented with concerns for deep vein thrombi, which were both medically managed, as well as one patient who had a non-fatal pulmonary embolism, which was also medically managed. The final HHS scores for these three patients were 83, 100, and 96 points. CONCLUSION: DM cups were designed with the intent of reducing hip instability. Most studies on these cups have reported on revision THA, where the problem of instability may be more paramount; however, fewer studies have reported on the use of this cup for primary THA. The findings from this study indicate excellent survivorship and overall clinical and patient satisfaction results using this construct. These five-year results are very encouraging and hopefully will portend excellent further survivorship with longer follow up.

A Systematic Review of Suture Technologies in Total Knee Arthroplasty.

Over time, various materials and techniques have been developed for superficial and deep wound closure. However, potential complications, such as infections and dehiscences, can still occur, driving the development of new closure modalities. As wound closure technology continues to advance and change, the need to continuously evaluate the current techniques and materials persists. Therefore, the purpose of this systematic review was to evaluate the current literature on the various closure materials and techniques utilized for total knee arthroplasty. Specifically, we evaluated: 1) closure times; 2) infections and complication rates; as well as 3) costs related to superficial and deep wound closures. Based on the findings from the current literature, barbed suture was associated with significantly shorter closing times in all five studies when compared to interrupted sutures (p<0.05). Additionally, the use of barbed sutures may result in similar postoperative complication rates. Although the cost of an individual barbed suture is potentially higher than the cost of an individual conventional suture, a knotless technique can require a shorter suture length, which might also help decrease costs.

Robotic-Assisted Total Knee Arthroplasty in the Presence of Extra-Articular Deformity.

INTRODUCTION: Tibial or femoral extra-articular deformities complicate the goal achieving optimal mechanical axis alignment for successful total knee arthroplasty (TKA) outcomes. In the presence of these extra-articular deformities, standard operative techniques and instruments may not be reliable. Robotic-arm assisted technology was developed to help achieve a well-aligned and balanced knee in a variety of clinical scenarios. Although prior case series have reported on the use of robotic-arm assisted devices for cases with severe angular deformity, there is a lack of data concerning the use of the robotic device for patients with other potentially complex surgical factors. Therefore, the purpose of this series was to present cases in which the robotic-arm assisted TKA application was used in the setting of extra-articular deformities to educate the surgeon community on this potentially useful method to address these complex cases. MATERIALS AND METHODS: Three cases of patients who underwent robotic-arm assisted TKA in the setting of preoperative extra-articular deformities were identified. These included one with femoral and tibial fracture malunion, another with a proximal tibial fracture nonunion, and another with a healed tibial plateau fracture. Patient clinical histories, intraoperative surgical techniques, and postoperative outcomes were obtained. Specific focus was placed on the surgical management of the patient's pre-existing deformity. RESULTS: These three case reports are discussed in detail, with emphasis on preoperative planning and intraoperative techniques. The robotic software was able to appropriately consider the extra-articular deformity in the preoperative and real-time updated intraoperative plans. Doing so, the surgeon was able to achieve balanced and aligned TKA in each case. All three patients underwent robotic-assisted total knee arthroplasty with no intraoperative or postoperative complications. For all patients, their anteroposterior and lateral radiographs demonstrated well fixed and aligned femoral and tibial components with no signs of loosening or osteolysis. On physical exam, all patients had excellent range-of-motion with mean flexion of 122° (range: 120 to 125° of flexion) at final follow up. DISCUSSION: The decision on how to best approach TKA in patients with extra-articular deformity should be based on an extensive patient history, physical examination, and thorough evaluation of the magnitude and proximity of the deformity to the knee joint. Utilizing preoperative CT-scans with a 3D plan for robotic-arm assisted surgery allowed for appropriate assessment of the deformity preoperatively and execution of a plan for a balanced and aligned total knee arthroplasty. We have demonstrated excellent results utilizing robotic-arm assisted TKA in these complex cases.

Difficult Revision Total Hip Arthroplasty Cases Treated with an Offset Head Center Acetabular Shell.

Acetabular bone loss is common during revision total hip arthroplasty (THA). A new acetabular shell was developed with a goal of maintaining native hip center-of-rotation (COR) while achieving good fixation with standard instrumentation and technique. Previous radiographic studies have demonstrated the efficacy of this shell in lowering hip COR. In this case series, we demonstrate the use of this shell in patients undergoing difficult revision THAs. Based on these cases, we have presented how this offset COR acetabular shell may help bring down the hip COR in patients who undergo revision total hip arthroplasty with severe bone loss.

Survivorship and Radiographic Analysis of Highly Porous Acetabular Cups Designed for Improved Osseointegration Potential.

INTRODUCTION: A variety of highly porous materials have been used to obtain biological acetabular fixation after total hip arthroplasty (THA). Due to their improved surface-coated properties, new highly porous titanium metal implants have shown potential to promote prosthesis osseointegration. Therefore, the purpose of this multicenter study was to evaluate: 1) overall acetabular cup survivorship; 2) postoperative complications; and 3) radiographic signs of loosening and radiolucencies in patients who received a new highly porous titanium metal cup. MATERIALS AND METHODS: A total of 81 patients who underwent primary THA and received a new porous acetabular cup between May 16, 2013 and January 27, 2016 at three academic centers were included for analysis. There were 40 women (49%) and 41 men (51%) who had a mean age of 65 years (range, 38 to 95 years) and a mean body mass index (BMI) of 28 kg/m2 (range, 16 to 43 kg/m2). The minimum follow up time was two years and seven months (range, 2 to 4 years). The cup was engineered with fully interconnected porosity designed for potential long-term biologic fixation. Medical records were reviewed to assess for any revision surgeries and postoperative complications, and the most recent radiographs were reviewed for signs of loosening or radiolucencies. RESULTS: Overall, acetabular component survivorship, free of fixation failure or aseptic loosening, was 100%. Two patients underwent revision due to dislocations; however, revisions were performed because no constrained or dual mobility liners were available for the shell at the time. Both patients had successful outcomes and were doing well at final follow up with no further episodes of dislocation. There was one open reduction internal fixation for a periprosthetic femoral fracture, and three polyethylene revisions were performed for instability. In all of these cases, the acetabular cup was retained. On radiographic evaluation of antero-posterior pelvis radiographs, there was one patient who had radiolucencies of <1mm in Zone 1 and Zone 2 at 15 months after surgery, and another patient demonstrated radiolucencies of <1mm in Zone 2 and 3 at one-year follow up. At a minimum of two-year follow up, both patients had non-progressive and stable findings. CONCLUSION: The results of this study demonstrated excellent survivorship, and there were no radiographic failures of this acetabular cup in primary total hip arthroplasty patients. Although two patients were found to have minimal (<1mm) radiolucencies, these were not progressive. Longer follow-up studies are needed to further assess the survivorship and outcomes of this new acetabular cup; however, based on the results of this study, these are expected to be favorable.

Current Concepts in Osteoarthritis of the Ankle: Review.

Ankle osteoarthritis constitutes a large burden to society and is a leading cause of chronic disability in the United States. Most commonly, it is post-traumatic, occurs in younger individuals, and is associated with obesity. This entity presents similarly to osteoarthritis of the other joints, with the typical nonspecific symptoms of stiffness, swelling, and pain. Radiographic investigation includes four weight-bearing standard views: antero-posterior and lateral foot, mortise view of the ankle, and a specialized view of the hindfoot. In this review, we covered epidemiology, anatomy and biomechanics, etiology, pathology, differential diagnoses, symptoms, physical examination, appropriate radiological investigation, as well as current treatment options and algorithms. Non-operative treatment options include weight loss, physical therapy, bracing, orthoses, pharmacologic treatments, corticosteroid injections, viscosupplementation, and biologic modalities. Viscosupplementation with hyaluronic acid has the most evidence-based support and has been shown to be safe and efficacious. For patients who have moderate to severe disease, surgery may be indicated. However, current surgical options are either associated with high rates of complications or restrict ankle range of motion (ROM). Early stages of the ankle osteoarthritis should be treated with the above-mentioned non-surgical methods, and once the disease progresses, surgical options can be utilized.

Comparison of a Posterior versus Anterior Approach for Lumbar Interbody Fusion Surgery Based on Relative Value Units.

INTRODUCTION: The current value-driven healthcare system encourages physicians to continuously optimize the value of the services they provide. Relative value units (RVUs) serve as the basis of a reimbursement model linking the concept that as the effort and value of services provided to patient's increases, physician reimbursement should increase proportionately. Spine surgery is particularly affected by these factors as there are multiple ways to achieve similar outcomes, some of which require more time, effort, and risk. Specifically, as the trend of spinal interbody fusion has increased over the past decade, the optimal approach to use-posterior versus anterior lumbar interbody fusion (PLIF vs. ALIF)-has been a source of controversy. Due to potential discrepancies in effort, one factor to consider is the correlation between RVUs and the time needed to perform a procedure. Therefore, the purpose of this study was to compare: 1) mean RVUs; 2) mean operative time; and 3) mean RVUs per unit of time between PLIF and ALIF with the utilization of a national surgical database. We also performed an individual surgeon cost benefit analysis for performing PLIF versus ALIF. MATERIALS AND METHODS: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was utilized to identify 6,834 patients who underwent PLIF (CPT code: 22630) and 6,985 patients who underwent ALIF (CPT code: 22558) between 2008 and 2015. The mean operative times (in minutes), mean RVUs, and RVUs per minute were calculated and compared using the Student's t-tests. In addition, the reimbursement amount (in dollars) per minute, case, day, and year for an individual surgeon performing PLIF versus ALIF were also calculated and compared. A p-value of less than 0.05 was used as the threshold for statistical significance. RESULTS: Compared to ALIF cases, PLIF cases had longer mean operative times (203 vs. 212 minutes, p<0.001). However, PLIF cases were assigned lower mean RVUs than ALIF cases (22.08 vs. 23.52, p<0.001). Furthermore, PLIF had a lower mean RVU/minutes than ALIF cases (0.126 vs. 0.154, p<0.001). The reimbursement amounts calculated for PLIF versus ALIF were: $4.52 versus $5.53 per minute, $958.66 versus $1,121.95 per case, and $2,875.98 versus $3,365.86 per day. The annual cost difference was $78,380.92. CONCLUSION: The data from this study indicates a potentially greater annual compensation of nearly $80,000 for performing ALIF as opposed to PLIF due to a higher "hourly rate" for ALIF as is noted by the significantly greater RVU per minute (0.154 vs. 0.126 RVU/minutes). These results can be used by spine surgeons to design more appropriate compensation effective practices while still providing quality care.

Robotic-Arm Assisted Total Knee Arthroplasty More Accurately Restored the Posterior Condylar Offset Ratio and the Insall-Salvati Index Compared to the Manual Technique; A Cohort-Matched Study.

INTRODUCTION: Despite the demonstrated success of modern total knee arthroplasty (TKA), it remains a procedure that involves sophisticated preoperative planning and meticulous technique to reconstruct the mechanical axis, achieve ideal joint balance, and restore maximal range-of-motion (ROM). Recently, robotic-arm assisted TKAs have emerged as a promising new technology offering several technical advantages, and it is achieving excellent radiological results, including establishing the posterior condylar offset ratio (PCOR) and the Insall-Salvati Index (ISI). Studies have demonstrated that these parameters are surgically modifiable, and their accurate restoration (fewer mean differences) correlate with improved final joint range-of-motion. However, there is a paucity of studies that evaluate these parameters in light of performing robotic-arm assisted TKA. Therefore, in this study, we aimed to compare: 1) PCOR and 2) ISI restoration in a cohort of patients who underwent robotic-arm assisted versus manual TKA. MATERIALS AND METHODS: We evaluated a series of 43 consecutive robotic-arm assisted (mean age 67 years; range, 46 to 79 years) and 39 manual total knee arthroplasties (mean age 66 years; range, 48 to 78 years) performed by seven fellowship-trained joint reconstructive surgeons. All surgeries were performed using medial para-patellar approaches by high-volume surgeons. Using the Knee Society Radiographic Evaluation System, preoperative and four-to six-week postoperative radiographs were analyzed to determine the PCOR and patella height based on the ISI. RESULTS: The mean postoperative PCOR was larger in manual TKA when compared to the robotic-assisted cohort (0.53 vs. 0.49; p=0.024). The absolute mean difference between pre- and postoperative PCOR was larger in manual when compared to robotic-arm assisted TKA (0.03 vs. 0.004; p=0.01). In addition, the number of patients who had postoperative ISI outside of the normal range (0.8 to 0.12) was higher in the manual cohort (12 vs. 4). CONCLUSION: Patients who underwent TKA using robotic-arm assisted technology had smaller mean differences in PCOR which has been previously shown to correlate with better joint ROM at one year following surgery. In addition, these patients were less likely to have values outside of normal ISI, which means they are less likely to develop patella baja, a condition in which the patella would impinge onto the patellar component, leading to restricted flexion and overall decreased ROM.

The use of non-vascularized bone grafts to treat osteonecrosis of the femoral head: indications, techniques, and outcomes.

Osteonecrosis of the femoral head (ONFH) is a multi-factorial disease with relatively unknown aetiology and unclear pathogenetic mechanism. Left untreated, the natural history of the disease is progressive collapse of the femoral head and destruction of the joint with substantial pain and disability. The disease primarily affects younger individuals, in whom many surgeons will typically prefer to delay performing total hip arthroplasty (THA). Therefore, increasing attention has been given to a wide variety of femoral head-preserving procedures. The use of non-vascularized bone grafting (NVBG) to treat ONFH has mainly been advocated for pre-collapse and select, early post-collapse lesions. Currently, multiple studies reported on various non-vascularized bone grafting techniques of treating ONFH. Clinical outcomes have varied widely, with success rates reported between 55 and 87% in the short- to mid-term, with long-term results lacking. Due to the current paucity of studies, in this review we aimed to discuss (1) indications, (2) techniques, and (3) outcomes of non-vascularized bone grafting used to treat osteonecrosis of the femoral head.

Consolidation and maturation of the orthopaedic medical device market between 1999 and 2015.

Orthopaedic surgeons often require highly specialized medical devices, implants, and equipment, which are usually offered by several vendors/companies. This study assesses long-term market trends for orthopaedic medical device companies and examines various implications for healthcare cost. Using S&P Capital IQ, a Wall Street database, financial data were gathered on orthopaedic device companies, ranked by worldwide sales, from 1999 to 2015. Annual sales were aggregated to calculate market share and compounded annual growth rates (CAGRs). Overall, the global orthopaedic device market grew at 12.0% CAGR from 1999 to 2008, before slowing to 2.8% from 2009 to 2015. Between 1999 and 2015, the top 5 companies increased total market share from 52.8 to 62.2%. The orthopaedic device market is not only consolidating under a few dominant players, but also growing at a decreasing rate, both of which signal a maturing industry. These trends are likely to shape patient care and healthcare costs in orthopaedic surgery in years to come.

Novel Acetabular Cup for Revision THA Improves Hip Center of Rotation: A Radiographic Evaluation.

BACKGROUND: Bone loss in patients undergoing revision THA poses a considerable challenge for orthopaedic surgeons. Often, to achieve better fixation in remaining bone, larger diameter acetabular components and reaming superiorly may be necessary. However, this is likely to raise the hip center of rotation, which may lead to altered biomechanics, specifically, insufficiency of the abductor muscles, altered gait, and increased risk of dislocation from impingement. More recently, a newer acetabular shell has been designed to more closely replicate the native hip center of rotation in these circumstances while maintaining adequate fixation. QUESTIONS/PURPOSES: The purpose of this study was to compare the radiographic parameters of this newer design with conventional hemispheric cups in revision THA. Specifically, we assessed the differences in (1) vertical center of rotation (COR) displacement and (2) horizontal COR displacement. METHODS: Between January 2016 and April 2016, five reconstructive surgeons at five institutions utilized a newer highly porous acetabular shell designed with peripheral screw holes and vertically eccentric COR to allow for restoration of center of hip rotation in revision THA. We included all patients who received this device. During this time, the general indications at these sites for using the new device included Paprosky Stage IIA, IIB, IIC, or IIIA acetabular defects. This yielded 29 patients who were subsequently matched (one to two) by cup size and sex to a cohort who underwent revision THA with conventional hemispheric cups between January 2015 and May 2016. To determine hip COR, radiographic measurements were performed. A circle contiguous to the acetabulum was drawn and the center was determined as the hip COR. All measurements were made from the interteardrop line for both the revised and native hips. A line through the teardrops was used for all horizontal measurements. Center position adjustments were made based on the manufacturer-specified values. Comparisons were performed using chi-square tests for categorical and t-tests for continuous variables. There was no difference in the severity of bone loss before the revision in the groups, as evidenced by Paprosky staging of preoperative radiographs. RESULTS: The mean vertical COR displacement was smaller in patients who had the novel cup (3.5 mm; range, -12 to 15 mm; mean difference, -7.3 mm; 95% confidence interval [CI], -13.2 to -1.5) as compared with those who had the conventional cup (10.5 mm; range, -4 to 50 mm; mean difference, 7.3 mm; 95% CI, -12.5 to -2.2; p = 0.003). There was no difference in mean horizontal displacement between the two groups (-0.06 ± 6.1 versus 1.7 ± 7.1; mean difference, -1.8; p = 0.903). CONCLUSIONS: Although hip COR was improved based on radiographic measurements with the use of this novel acetabular design, and although this may improve hip biomechanics, more studies are required before its widespread adoption for revision cases of this nature can be recommended. Both implant costs and the risks associated with using a new design in practice will have to be justified by studies that evaluate fixation, clinical function and implant survival, and patient-reported outcome scores, all of which were beyond the scope of this preliminary report. LEVEL OF EVIDENCE: Level III, therapeutic study.

Modern Dual-Mobility Cups in Revision Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: The purpose of this systematic review is to analyze the outcomes of dual-mobility (DM) cups in revision total hip arthroplasty (THA). Specifically, we evaluated the following: (1) all-cause and aseptic survivorship rates; (2) dislocation rates; (3) complications; and (4) clinical outcomes reported using validated health status measures. METHODS: A comprehensive literature search included studies that reported the following: (1) re-revision rates, (2) complications, and (3) clinical outcomes following DM use in revision THA. The following exclusion criteria were used: (1) studies that did not stratify their analysis between primary and revision THA, (2) studies that utilized off-label techniques, (3) review articles, (4) case studies, (5) basic science articles, (6) non-English language reports, and (6) reports on patients who underwent surgery before 2010, in order to reflect modern DM implants use and technology. A total of 9 studies were included in our final analysis. RESULTS: Aseptic and all-cause survivorship rates were 97.7% and 94.5%. Prevalence of dislocation was 2.2%, and 0.3% for intraprosthetic dislocation. Meta-analysis comparing DM to fixed-bearing prostheses demonstrated a significantly lower odds of dislocation in the DM cohort (odds ratio 0.24, P = .002). Complications occurred in 7.4% of revision THAs with DM cups, while infection rates totaled to 3.3% of cases. Studies comparing outcomes using Harris Hip Scores did not demonstrate a statistically significant difference in improved postoperative scores (P > .05). CONCLUSION: DM cups have demonstrated excellent survivorship, low dislocation, and overall complication rates. Therefore, it can be considered a safe and effective option, particularly in the high-risk patients who undergo revision THA.

Acute septic arthritis of the knee: A rare case report of infection with Parvimonas micra after an intra-articular corticosteroid injection for osteoarthritis.

Acute bacterial mono-articular septic arthritis affects most commonly the lower extremity joints in adult population and most commonly caused by Staphylococcus aureus. Various risk factors determine susceptibility to infection including host immunity, medical co-morbidity and joint structural abnormality and other organisms may be involved. Parvimonas micra (P. micra) is among the rare organisms that may be associated with atypical septic arthritis and primarily affects the native knee joint. Only 3 case reports in the literature have reported on pyogenic pyogenic joint infection caused by this organism. We hereby present our experience with a case of knee septic arthritis caused by P. micra in a patient with knee osteoarthritis following a recent intra-articular injection with corticosteroids. In susceptible patients, Intra-articular corticosteroid injection and crystal induced arthritis may propose a potential risk of contracting infection with P. micra.

Robotic Arm-Assisted Total Knee Arthroplasty.

BACKGROUND: Robotic arm-assisted total knee arthroplasty (RATKA) has a number of potential advantages. Therefore, in order to more comprehensively assess this technology, we reviewed the (1) accuracy and precision; (2) soft-tissue protection; (3) patient satisfaction; (4) learning curve; and (5) its other potential benefits. METHODS: A literature review was conducted using PubMed search database for studies reporting clinical outcomes, cadaver results, radiographic outcomes, surgeon experience, and robotic accuracy. Forty articles were included for the final analysis. RESULTS: Advantages of RATKA may include greater component accuracy and precision, soft-tissue protection, increased patient satisfaction, a short learning curve, optimal ergonomic design, and less surgeon and surgical team fatigue. The aforementioned advantages might help improve clinical, surgical, and patient-reported outcomes. CONCLUSION: Although there are a number of studies that highlight the potential advantages of RATKA, most of these studies report of short-term outcomes. It is hoped that longer term studies will continue to support the use of this technology in providing higher patient satisfaction and other clinical outcomes.