Robotic Arm-Assisted versus Manual Total Knee Arthroplasty: A Propensity Score-Matched Analysis

The purpose of this study was to compare (1) operative time, (2) in-hospital pain scores, (3) opioid medication use, (4) length of stay (LOS), (5) discharge disposition at 90-day postoperative, (6) range of motion (ROM), (7) number of physical therapy (PT) visits, (8) emergency department (ED) visits, (9) readmissions, (10) reoperations, (11) complications, and (12) 1-year patient-reported outcome measures (PROMs) in propensity matched patient cohorts who underwent robotic arm-assisted (RA) versus manual total knee arthroplasty (TKA). Using a prospectively collected institutional database, patients who underwent RA- and manual TKA were the nearest neighbor propensity score matched 3:1 (255 manual TKA:85 RA-TKA), accounting for various preoperative characteristics. Data were compared using analysis of variance (ANOVA), Kruskal-Wallis, Pearson's Chi-squared, and Fisher's exact tests, when appropriate. Postoperative pain scores, opioid use, ED visits, readmissions, and 1-year PROMs were similar between the cohorts. Manual TKA patients achieved higher maximum flexion ROM (120.3 ± 9.9 versus 117.8 ± 10.2, p = 0.043) with no statistical differences in other ROM parameters. Manual TKA had shorter operative time (105 vs.113 minutes, p < 0.001), and fewer PT visits (median [interquartile range] = 10.0 [8.0-13.0] vs. 11.5 [9.5-15.5] visits, p = 0.014). RA-TKA had shorter LOS (0.48 ± 0.59 vs.1.2 ± 0.59 days, p < 0.001) and higher proportion of home discharges (p < 0.001). RA-TKA and manual TKA had similar postoperative complications and 1-year PROMs. Although RA-TKA patients had longer operative times, they had shorter LOS and higher propensity for home discharge. In an era of value-based care models and the steady shift to outpatient TKA, these trends need to be explored further. Long-term and randomized controlled studies may help determine potential added value of RA-TKA versus manual TKA. This study reflects level of evidence III.

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.

Robotic-arm assisted versus manual total hip arthroplasty: Systematic review and meta-analysis of radiographic accuracy

BACKGROUND

We systematically reviewed the radiological outcomes of studies comparing robotic-assisted (RA-THA) and manual total hip arthroplasty (mTHA).

METHODS

The PubMed, Embase, and Cochrane databases were queried from 1994-2021 for articles comparing radiographic outcomes between RA-THA and mTHA cohorts. A meta-analysis was conducted whenever sufficient data was present for common outcomes.

RESULTS

Our analysis included 20 articles reporting on 4140 patients (RA-THA: n = 1228; mTHA: n = 2912). No differences were demonstrated for acetabular inclination or anteversion. However, RA-THA demonstrated higher rates of cup orientation within the Lewinnek and Callanan safe zones, improved femoral stem alignment, and lower global offset difference (GOD) and limb length discrepancy (all p-values <0.05). Superior femoral canal fill and combined offset were seen among RA-THA patients.

CONCLUSION

Our review found that the use of RA-THA yields superior radiographic outcomes compared to mTHA counterparts. This information can inform healthcare systems considering investing in and implementing these technologies.

The Olerud Extensile Anterior Approach for Complex Distal Femoral Fractures: A Systematic Review

The management of AO/OTA (AO Foundation/Orthopaedic Trauma Association) 33-C3 complex distal femoral fractures presents challenges for orthopaedic surgeons. The extensile anterior approach may be an appropriate alternative treatment technique. The purpose of this systematic review is to (1) evaluate the Olerud approach (extensile anterior approach) for the treatment of 33-C3 complex distal femoral fractures and (2) evaluate postoperative patient outcomes. A systematic literature search was performed to retrieve studies that evaluated the treatment of 33-C3 complex distal femoral fractures. The PubMed database query resulted in 429 studies. Two reviewers independently reviewed the studies, of which six were identified. Patient demographics, AO/OTA fracture, surgical intervention, follow-up duration, clinical outcomes, and postoperative complications were collected and analyzed. The systematic review included six studies reporting on 85 patients (43 males and 42 females); the mean patient age was 45 years (range: 16-101 years). The most common cause of injury was road/traffic accident (51 patients). The mean follow-up time was 26 months (range: 3-72 months). In five studies, the mean time for union was 5.8 months (range: 2-9 months). The three most commonly reported complications were infection (seven [8.2%] patients), failure/malunion (three [3.5%] patients), and delayed tibial tuberosity osteotomy healing (three [3.5%] patients). Seventy (82.4%) patients did not suffer any postoperative complications. Out of 72 patients, 7 (9.7%) had resultant varus/valgus deformity. Overall, 57.1% had excellent/good functional outcomes. Based on the systematic literature review, the extensile anterior approach may be a viable alternative surgical option for 33-C3 complex distal femoral fractures. Given the current literature, more comprehensive and extensive studies need to be performed to ensure the best possible outcome.

The Impact of Malnutrition on 30-Day Postoperative Complications following Surgical Fixation of Distal Radius Fractures

Introduction  Distal radius fractures (DRFs) are increasingly managed surgically among fragility fractures due to prolonged life expectancy and surgical advancements. Yet, malnutrition can impact postoperative outcomes and complications. We sought to determine the impact of malnutrition on open reduction and internal fixation (ORIF) of DRFs during the perioperative and 30-day postoperative periods. Materials and Methods  Using the National Surgical Quality Improvement Program database, all patients who underwent ORIF of a DRF between January 1, 2008, and December 31, 2016, were identified and stratified by preoperative serum albumin levels: normal (≥3.5 g/dL; n = 2,546) or hypoalbuminemia (<3.5 g/dL; n = 439). Demographical and perioperative data were compared. Operative complications were stratified into major and minor complications, and data were analyzed using descriptive statistics and multivariate regression models. Results  Compared with patients with normal levels, a higher proportion of hypoalbuminemia patients had ASA scores > 3 (9.1 vs. 2%) and a longer mean length of stay (3.16 vs. 0.83 days). Hypoalbuminemia patients also had 625% greater odds for developing major complications during the 30-day postoperative period (odds ratio = 7.25; 95% confidence interval: 1.91-27.49). Conclusion  Malnutrition significantly affected outcomes and complications of distal radius ORIF. This study highlights the importance of prevention and treatment of malnutrition in the setting of fragility fractures.

Malnutrition increases the 30-day complication and re-operation rates in hip fracture patients treated with total hip arthroplasty

INTRODUCTION

This study sought to determine the effect that malnutrition, defined as hypoalbuminemia, has on hip fracture patients treated with total hip arthroplasty (THA). Specifically, we evaluated: (1) demographics and perioperative data; (2) postoperative complications; and (3) re-operation rates.

METHODS

The National Surgical Quality Improvement Program database was utilised to identify hip fracture patients who underwent THA from 2008 to 2015. Propensity scores were calculated for the likelihood of having a preoperative albumin measurement. Hip fracture patients who underwent THA and had preoperative hypoalbuminemia (<3.5 g/dL) (n = 569) were compared to those who had normal albumin levels (⩾3.5 g/dL) (n = 1098) in terms of demographics and perioperative data. Regression models were adjusted for age, sex, modified Charlson/Deyo scores, and propensity scores to evaluate complication and re-operation rates.

RESULTS

Compared to controls, hypoalbuminemia patients were older (p = 0.006), more likely male (p = 0.024), had higher Charlson/Deyo scores (p = 0.0001), more likely smokers (p < 0.0001), more likely functionally dependent (p < 0.0001), had ASA scores ⩾3 (p < 0.0001) and had longer LOS (p < 0.0001). Compared to controls, hypoalbuminemia patients had 80% higher risk for any complication (OR = 1.80; 95% CI, 1.43-2.26), 113% higher risk for major complications (OR = 2.13; 95% CI, 1.31-3.48), and 79% higher risk for minor complications (OR = 1.79; 95% CI, 1.42-2.26), and 97% increased risk for re-operation (OR = 1.97; 95% CI, 1.20-3.23).

CONCLUSIONS

The findings in the present study indicate the need to develop better pre- and postoperative medical and nutritional care for malnourished hip fracture patients who undergo THA in order to potentially mitigate their increased risk.

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.

Patient-Reported Functional and Satisfaction Outcomes after Robotic-Arm-Assisted Total Knee Arthroplasty: Early Results of a Prospective Multicenter Investigation

The purpose of this study was to perform a 3-month interim comparative analysis on outcomes between robotic-arm-assisted total knee arthroplasty (RATKA) and manual TKA patients. Specifically, we evaluated (1) patient self-reported symptoms, (2) expectations and satisfaction, and (3) functional activities, based on the 2011 Knee Society Scoring System. Between June 1, 2016, and March 31, 2018, 252 patients (102 manual and 150 robotic) were enrolled into a prospective, nonrandomized, open-label, multicenter comparative cohort study. Functional activity scores, patient-reported symptoms, as well as satisfaction and expectation scores were obtained from the 2011 Knee Society Scoring System preoperatively, at 4 to 6 weeks, and at 3 months postoperatively. Student's t-tests, Wilcoxon rank-sum tests, and chi-square tests with α set at 0.05 were used to compare between-group mean improvements from baseline. At 4 to 6 weeks postoperatively, RATKA patients were found to have significantly larger improvements in walking and standing (1.4 vs. -1.2 points; p = 0.019). RATKA patients were also found to have larger improvements in advanced activities (1.3 vs. 2.3 points), pain with walking (3.3 vs. 3.2 points), satisfaction score (12.4 vs. 12 points), and expectations score (5.1 vs. 4.4 points) when compared with manual TKA patients. At 3 months, RATKA patients were also found to have larger improvements in walking and standing (6.0 vs. 4.8 points), standard activities (11.4 vs. 10.1 points), advanced activities (6.2 vs. 4.6 points), functional activities total score (22.8 vs. 21.2 points), pain with walking (4.3 vs. 4.1 points), total symptoms score (10.5 vs. 10.3 points), satisfaction score (17.0 vs. 15.5 points), expectations score (4.8 vs. 4.0 points) when compared with manual TKA patients. The data indicate RATKA patients to have equal or greater improvements in 9 out of 10 of the Knee Society Scoring System components assessed at 3 months postoperatively, though not all findings were statistically significant. Since this is an early results report, this study will be continued for a longer follow-up, but we are encouraged by these interim results.

Survivorship and Functional Outcomes of Cementless versus Cemented Total Knee Arthroplasty: A Meta-Analysis

The purpose of this meta-analysis was to assess the evidence supporting the use of cementless versus cemented total knee arthroplasties (TKAs). Specifically, we evaluated (1) all-cause survivorship, (2) aseptic survivorship, and (3) functional outcomes (Knee Society Scores [KSS], Oxford Knee Scores, Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] scores, and ranges of motion [ROMs]). A literature search was performed for studies that evaluated cementless versus cemented TKAs published between 2000 and 2017. Selected studies included three randomized controlled trials, three retrospective observational studies, and one prospective observational study that met the following criteria: (1) primary TKAs, (2) compared cementless and cemented TKAs, (3) implant survivorship that described the causes of failure, and (4) at least one functional outcome. To compare the two cohorts, pooled odds ratios (OR) and 95% confidence intervals (95% CI) were used to calculate tibial and femoral implant survivorship, and pooled mean differences (MD) and 95% CI calculated the functional scores and ROMs. Based on pooled data from the few number of studies, cementless TKAs had a better all-cause survivorship (OR = 0.37; 95% CI, 0.15-0.92) and tended to have a better aseptic survivorship (OR = 0.44; 95% CI, 0.17-1.14). However, this is likely due to the 83.3% weight of the single cementless study potentially influencing the analysis. There were no differences in terms of KSS knee (MD = 1.03; 95% CI, -1.13-3.20) or function scores (MD = 5.36; 95% CI, -3.75-14.51), Oxford knee scores (MD = 0.36; 95% CI, -3.84-4.56), or WOMAC scores (MD = 0.62; 95% CI, -0.87-2.11). Moreover, there was no difference in ROMs (MD = 1.47; 95% CI, -0.11-3.05). Cementless TKA had a better all-cause survivorship when compared with cemented fixation, and similar functional outcomes were demonstrated. However, these findings are based on only a few number of studies (n = 7). Therefore, additional prospective, randomized control trials need to be performed to best compare cementless versus cemented outcomes.

The effect of body mass index on 30-day complications after total hip arthroplasty

BACKGROUND

Evaluating body mass index (BMI) as a continuous variable eliminates the potential pitfalls of only considering BMI as a binary or categorical variable, as most studies do when correlating BMI and total hip arthroplasty (THA) outcomes. Therefore, the objective of this study was to correlate the effect of continuous BMI on 30-day complications post-THA. Specifically, we correlated BMI to: (1) 30-day readmissions and reoperations; (2) medical complications; and (3) surgical complications in: (a) normal-weight; (b) over-weight; (c) obese; and (d) morbidly obese patients.

METHODS

Using the NSQIP database, 93,598 primary THAs were identified. 30-day rates of readmissions, reoperations, and medical/surgical complications as well as patient BMI data were extrapolated. A comparative analysis using univariate, multivariate, and spline regression models adjusting for demographics and comorbidities were created to study the continuous effect of BMI on different outcomes.

RESULTS

Readmission (p < 0.001), reoperation (p = 0.007), superficial infection (p = 0.003), prosthetic joint infection (p < 0.001), and sepsis (p = 0.026) had a J-shaped relationship with BMI, with the lowest rates seen in patients with BMI around 28 kg/m². The risks of mortality (p = 0.007) and transfusion (p < 0.001) had a reverse J-shaped relationship, with the risk steadily decreasing for BMIs in the normal weight and overweight range, and then flattening afterwards.

CONCLUSION

This data proposes a multifactorial effect of BMI on post-THA complications. Considering BMI as a continuous variable allows for a better assessment when considering the interplay between modifiable risk factors, such as smoking or alcohol use, as well as multiple comorbidities.

Results of a Phase II Study to Determine the Efficacy and Safety of Genetically Engineered Allogeneic Human Chondrocytes Expressing TGF-β1

Genetically engineered chondrocytes virally transduced with a transforming growth factor (TGF)-β1 (TG-C [TissueGene-C]) expression vector have been shown to have potential benefits in the nonoperative management of knee osteoarthritis. Previous literature has reported on safe dosages of TG-C. Therefore, the purpose of this study was to evaluate the Phase II results and a 24-month efficacy of this injectable mixture compared with placebo in patients with Kellgren-Lawrence (K-L) grade III knee osteoarthritis. Specifically, we assessed (1) functional outcomes, (2) pain scores, (3) adverse events (AEs), and (4) magnetic resonance imaging (MRIs) findings. We performed a multicenter, double-blinded, placebo-controlled, and randomized study of adults who had K-L grade III knee osteoarthritis. A total of 102 patients were 2:1 randomized to TG-C at a dose of 3.0 × 10⁷ cells, or placebo injections between May 1, 2011 and October 31, 2012. Outcomes analyzed were knee joint function, pain, quality of life, adverse events, and MRI findings using the whole-organ magnetic resonance imaging score (WORMS) system. There were significant improvements in the International Knee Documentation Committee (IKDC) and visual analogue scale (VAS) scores in the TG-C cohort, when compared with the placebo cohort at weeks 12, 52, 72, and 104 (p < 0.05). No severe AEs were observed. Common AEs were arthralgia, joint inflammation, and joint effusion which were similar between both cohorts. Whole-knee MRIs at 12 months showed less progression of cartilage damage, infrapatellar fat pad-synovitis, and effusion-synovitis in the TG-C cohort. Patients who received TG-C had significant improvements in IKDC and VAS scores. These patients also reported less severe and frequent pain. Additionally, fewer patients treated with TG-C showed progression of cartilage damage, as well as less progression of infrapatellar fat pad synovitis and effusion-synovitis. Furthermore, treatment with TG-C was generally well tolerated with minor AEs. Therefore, based on these results, TG-C appears to be a safe and effective modality for the management of K-L grade III osteoarthritis.

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.

Does the Robotic Arm and Preoperative CT Planning Help with 3D Intraoperative Total Knee Arthroplasty Planning?

Although several studies highlight the advantages of robotic arm-assisted total knee arthroplasty (RA-TKA), few investigate its intraoperative outcome. Therefore, the purpose of this study was to analyze the RA-TKA's ability to assist with intraoperative correction of: (1) flexion and (2) extension gaps, as well as its ability to (3) accurately predict implant sizes. Additionally, in this RA-TKA cohort, length of stay, complications, and readmissions were assessed. A total of 335 patients who underwent RA-TKA were included. The robotic software virtually measured the intraoperative prebone cut extension and flexion gaps. Differences in medial versus lateral prebone cut extension and flexion gaps were calculated. A total of 155 patients (46%) had an extension gap difference of between -2 and 2 mm (mean, -0.3 mm), while 119 patients (36%) had a flexion gap difference of between -2 and 2 mm (mean, -0.6 mm). Postbone cut differences in medial versus lateral flexion and extension gaps were measured. Balanced knees were considered to have a medial and lateral flexion gap difference within 2 mm. The robot-predicted implant size was also compared with the final implant size. Additionally, lengths of stay, complications, and readmissions were assessed. All patients achieved a postbone cut extension gap difference between -1 and 1 mm (mean, -0.1 mm). A total of 332 patients (99%) achieved a postbone cut flexion gap difference of between -2 and 2 mm (mean, 0 mm). For 98% of prostheses, the robotic software predicted within 1 implant size the actual tibial or femoral implant size used.The mean length of stay was found to be 2 days. No patients suffered from superficial skin infection, pin site infections or fractures, soft tissue damage, and no robotic cases were converted to manual TKA due to intraoperative complications. A total of 8 patients (2.2%) were readmitted; however, none were directly related to robotic use. The robotic software and use of a preoperative computed tomography (CT) substantially helped with intraoperative planning and accurate prediction of implant sizes. Therefore, based on the results of this study, the RA-TKA device does, in fact, provide considerable intraoperative assistance.

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.

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.

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.

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.

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-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.

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.

Intravenous Acetaminophen May Be Associated with Reduced Odds of 30-Day Readmission after Total Knee Arthroplasty

The purpose of this study was (1) to evaluate 30-day readmission rates in total knee arthroplasty (TKA) patients who either received intravenous (IV) or oral (PO) acetaminophen (APAP) perioperatively and (2) to extrapolate the potential annual cost savings on the national level. This was a review of 190,691 TKA recipients between the years 2012 and 2015 who received either IV (n = 56,475) or PO APAP (n = 134,216). All-cause readmissions that occurred between patient discharge and 30 days postdischarge were recorded. Continuous and categorical variables were evaluated using t-test and chi-square test, respectively. A logistic regression analysis was conducted to assess the effect of IV APAP on 30-day readmission. We also performed a literature review on 30-day readmission rates and risk prediction tools for TKA and correlated these with our findings. In addition, we extrapolated potential cost savings on the national level. The readmission rate was 0.04% in the IV and 0.14% in the PO APAP cohort (69% decreased risk; odds ratio = 0.31; 95% confidence interval = 0.20-0.47; p < 0.001). The readmission rate in this patient population appears to be markedly lower, when compared with previous reports. This reduction in readmissions may potentially result in $160 million savings per year. The use of IV APAP in TKA patients resulted in lower readmission rates, which may be valuable in clinical decision making by surgeons and health care administrators looking to lower costs of care.

Short-term outcomes after anatomic total shoulder arthroplasty in patients with osteoarthritis versus osteonecrosis

Background

The outcomes of anatomic total shoulder arthroplasty (TSA) for glenohumeral osteoarthritis (OA) have been extensively reported in the literature. However, there is a paucity of short-term outcomes data on perioperative and post-operative outcomes in patients receiving TSA for either glenoid or humeral head osteonecrosis (ON). We compared the short-term outcomes of TSA performed on patients who had glenohumeral OA and those who had ON. Specifically, we compared: (I) demographics; (II) length-of-stay (LOS); and (III) 30-day postoperative complication rates.

Methods

Data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) was used to select 7,066 patients with a diagnosis of glenohumeral OA or ON who underwent TSA between January 1^st, 2008 and December 31^st, 2015. Propensity score matching was performed based on age, sex, race, and body mass index (BMI) with a 3:1 ratio of OA to ON patients. As a result, 387 patients who had a primary diagnosis of OA were compared with 129 patients who had ON. Analyses addressed perioperative complications and hospital disposition factors-including LOS and 30-day post-operative complications-using bivariate and logistic regression models.

Results

Overall complication rates were low in both groups, at 6.1% and 5.4% for the ON and OA cohorts respectively. The ON cohort had more comorbidities, including higher Charlson/Devo and American Society of Anesthesiologists (ASA) scores (P<0.05). Hospital disposition factors were not statistically different between the 2 groups. While not statistically significant, the ON cohort had a longer average (21.1% longer, P>0.05), an increased risk for developing any complication [odds ratio (OR) =2.07; 95% confidence interval (CI), 0.94 to 4.57; P=0.07], and a 134% higher risk for developing a minor complication compared to the OA (OR =2.34; 95% CI, 1.01 to 5.42; P=0.047).

Conclusions

Although the patient populations who develop ON or shoulder OA have differences, there are not statistically or clinically meaningful differences in the short-term outcomes after anatomic TSA. Future studies are required to examine if differences exist in the long-term follow-up between the two groups.

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.

Top 100 Most-Cited Clinical Studies of Hip and Knee Arthroplasty: The Foundation of Practice

Total number of citations has been considered a proxy for a published study's importance within a given field. However, there are multiple pitfalls to correlating the total number of citations alone with the quality of a study. In this review, the authors aimed to identify the top 100 most-cited studies of hip and knee arthroplasty and then assess study design and quality of reporting. More than half of these studies were level IV evidence, unblinded, not randomized, and not controlled. This underscores the need for higher-quality study design to support practice. [Orthopedics. 2019; 42(2):e151-e161.].

Accelerated Growth of Cellular Therapy Trials in Musculoskeletal Disorders: An Analysis of the NIH Clinical Trials Data Bank

The purpose of this study was to (1) determine the growth rate and the trends of musculoskeletal cellular therapy trials in the National Institutes of Health Clinical Trials Data Bank; (2) analyze the study design and characteristics; and (3) assess which cellular therapies and disease conditions are studied. A systematic review of musculoskeletal clinical trials from 2005 to 2016 using cell-based therapies as the primary intervention was performed through ClinicalTrials.gov. The number of musculoskeletal cell-based clinical trials is increasing, with most being early stage, phase I/II, and using autologous cells harvested mostly from bone marrow to target cartilage-related diseases. Among the 282 clinical trials identified, only 99 (35.1%) were completed; 62 of the 99 (62.6%) did not list any related publications. [Orthopedics. 2019; 42(2):e144-e150.].

Quadriceps tendinopathy: a review, part 2-classification, prognosis, and treatment

Overuse injuries of the extensor mechanism of the knee are common in both athletes and non-athletes and usually occur during activities associated with repetitive loading, stress, and knee extension. Numerous reports have been published describing extensor mechanism injuries in athletes, but there is a paucity of studies that focus on quadriceps tendinopathy in the non-athlete population. In addition, there is no universally accepted classification system for tendon pathology. Therefore, we performed a comprehensive literature review of these studies. This review consists of 2 parts. In the previous part we reviewed: (I) epidemiology and (II) diagnosis of quadriceps tendinopathy in the athlete as well as the general population. In this part we discuss: (I) classification; (II) prognosis; and (III) treatment results.

Not all primary total hip arthroplasties are equal-so is there a difference in reimbursement?

Background

Relative value units (RVUs) are a physician reimbursement model based on the effort required, or value, in providing a procedure or service for a patient. Procedures such as conversion total hip arthroplasties (THAs) can be compared to primary THAs, but many studies have revealed increased difficulties in conversion cases. Despite the increased time and effort for conversion THA, it is unknown if this is reflected in the RVU compensation model. Therefore, the purpose of this study was to compare the: (I) mean operative times; (II) mean RVUs; (III) RVU/minute for primary and conversion THAs; and (IV) perform an individualized idealized surgeon annual cost difference analysis.

Methods

A total of 103,702 primary THA patients were identified using CPT code 27130 and 2,986 conversion THA patients were identified using CPT code 27132 using the National Surgical Quality Improvement Program (NSQIP) database. The mean RVUs, operative times (minutes), and RVU/minute were calculated and compared. An annualize cost analysis of dollar amounts per case, day, and the year was also performed.

Results

The mean operative times for the primary and conversion THA cohorts were 94 vs. 146 minutes (P<0.001) and mean RVUs were 21.24 vs. 25.68 (P<0.001). Interestingly, the mean RVU per minute was higher for the primary THA compared to the conversion THA groups (0.26 vs. 0.21, P<0.001). Annualized cost analysis revealed a potential $173,529 difference from performing primary vs. conversion THAs.

Conclusions

Even though conversion THA can be considered to a more complex and demanding procedure, based on RVUs per minute of surgery, orthopaedic surgeons are reimbursed better for primary THA cases. This data could be used by orthopaedic surgeons to administer their practices better to yield the highest return on time.

What are the Short-Term Outcomes in Multiple Sclerosis Patients after Total Knee Arthroplasty?

Due to the paucity of evidence, this study was conducted to evaluate: (1) unique characteristics of multiple sclerosis (MS) patients and (2) short-term clinical outcomes, of primary total knee arthroplasty (TKA) in patients with MS (MS-TKA) compared with matched non-MS patients. MS patients who underwent TKA were identified using the Nationwide Inpatient Sample (NIS) database. The study sample consisted of 10,884 patients with MS and 56,45,227 control cohort. Various patient factors were compared. To control for potential confounders, with the use of propensity scores, MS-TKA patients were matched (1:3) to non-MS-TKA patients and regression analyses were performed to compare perioperative complications, length of stay (LOS), and discharge dispositions. Patients with MS were younger, more likely to be females, on corticosteroids, and more likely to have muscle spasms and gait abnormalities. Annual frequency of TKAs in MS patients increased from 1.16/1,000 TKAs in 2002 to 2.48/1,000 TKAs in 2013 (p < 0.001). Compared with the matched cohort, MS patients had significantly greater odds for any medical complication (odds ratio [OR] = 1.26; 95% confidence interval [CI], 1.11-1.44), longer mean LOS (mean difference: 0.15; 95% CI, 0.09-0.22), and had a greater chance of being discharged to a care facility (OR = 2.17; 95% CI, 1.96-2.40). In this study, we identified specific characteristics of patients with MS who had TKA and analyzed and compared their short-term TKA outcomes to non-MS patients. It was demonstrated that more patients with MS are undergoing TKA, and these patients were at a higher risk of perioperative complications, had longer LOS, and were more likely to be discharged to a sub-acute or inpatient facility. Orthopaedic surgeons should be cognizant of the increased risks and provide proper counseling to MS patients who are candidates for TKA.

Patient satisfaction and outcomes of static progressive stretch bracing: a 10-year prospective analysis

Background

Multiple surgical and non-surgical modalities are available for patients suffering from shoulder elbow, forearm, wrist, knee and ankle stiffness. For most patients, bracing can provide optimal therapy to restore functional range of motion (ROM). Three commonly used bracing mechanisms include static progressive stretch (SPS), turnbuckle, and dynamic bracing. However, although, in general, these three brace types have been shown to have successful outcomes, there are a number of different manufacturers, and company specific designs might affect outcomes. Therefore, the purpose of this study was to analyze 10 years of prospectively collected patient satisfaction and outcomes data from a single brace company. Specifically, we evaluated: (I) mobility, (II) pain, (III) stiffness, (IV) swelling, and (V) any adverse events of patients treated with an SPS brace.

Methods

From 2007 to 2017, data from a total of 167,751 patients treated with a JAS Brace (Joint Active Systems Inc., Effingham, IL, USA) were prospectively collected through a cross-sectional survey addressing various outcomes such as pain, stiffness, swelling and mobility. More specifically, patients were asked "Are you having pain?", "Do you have any stiffness?", "Do you have any swelling?", and "Do you feel your mobility has improved?" Patients who answered "yes" were then asked to categorize their response as either worse, same, or better (or improvement) for pain, stiffness, and swelling. For mobility, patients answered either "yes", "no", or "undecided". This data was then graphed and a yearly trends analysis was performed. We also assessed the number of complaints as well as any device related adverse events.

Results

In 2008, 59% of patients reported no pain, 45% no stiffness, and 79% no swelling after device use. Those numbers increased by 2013, to 70% of patients reporting no pain, 79% reporting no stiffness, and 84% reporting no swelling after brace use. A consistent positive trend was also seen for mobility, with at least 90% of patients reporting improved mobility after orthosis use. The number of complaints decreased from 38 in 2007 to 3 in 2017. No patients experienced any device related serious injuries.

Conclusions

Overall, to the best of the author's knowledge, this study is the first to demonstrate a brace designed to improve ROM also has significant effect on pain, stiffness, and swelling. These results are of particular importance, since no other study reports prospective data on thousands of patients showing that a bracing system substantially reduces pain and stiffness. These data indicate that not only or these SPS braces effective in improving functional ROM with high rate of success and no significant complications, but this bracing system has a significant effect on improving pain and stiffness. Based on the results from this study, patients suffering from shoulder, elbow, forearm, wrist, knee and/or ankle pathology can expect excellent clinical outcomes by using one of the above braces.

Mortality after hip resurfacing versus total hip arthroplasty in young patients: a single surgeon experience

Background

The aims of this study were to investigate the following questions: (I) what are the mortality rates in patients age 55 years and younger who underwent a hip resurfacing arthroplasty (HRA) versus a standard total hip arthroplasty (THA)? (II) is the type of operation independently associated with mortality?

Methods

The database of a single high-volume surgeon was reviewed for patient's age 55 years and younger who underwent a hip arthroplasty between 2002 and 2010. This yielded 505 HRA patients and 124 THA patients. Chi-square analysis was performed to identify a 5-year mortality rate difference between the two cohorts. Multivariable Cox-Regression analyses were used to determine whether the type of operation was independently associated with mortality.

Results

There were 8 mortalities (1.6%) in the HRA cohort and 11 (8.9%) in the THA cohort, a statistically significant difference (P<0.001) on univariate analysis. Low mortality rates produced underpowered multivariate models.

Conclusions

We have demonstrated that patients age 55 and younger who undergo HRA have a significantly lower mortality rate than those undergoing THA. This is consistent with multiple previously published large database studies.

Astym® therapy: a systematic review

Soft tissue dysfunction can result from the degeneration of tissues as in the case of degenerative tendinopathy or from the build-up of problematic scar tissue, which can be the result of several aggravating factors, including overuse injuries, acute or chronic trauma, or as a result of surgery. This dysfunction often results in impaired movement, pain, and swelling of the affected area, which can lead to patient dissatisfaction and a lower quality of life. These soft tissue dysfunctions also have a marked economic impact. Although a number of traditional treatments attempt to address these issues, no optimal treatment choice has emerged. Traditional treatments are not always successful, can be invasive, and can consume many medical resources. A relatively new treatment approach, Astym therapy, is a potentially useful, non-invasive, more cost-effective option. This therapy was developed to address soft-tissue dysfunctions by stimulating the regeneration of soft tissues and the resorption of inappropriate scar tissue/fibrosis. It has been reported to help with the resorption and remodeling of abnormal tissue, thereby leading to improved motion, function and pain relief. The purpose of this analysis was to review the published literature related to Astym therapy on various musculoskeletal disorders. Specifically, we evaluated the effectiveness of this therapeutic method on disorders related to the: (I) knee; (II) upper extremity; (III) hamstring muscles; and (IV) ankle and Achilles tendon injuries.

Quadriceps tendinopathy: a review-part 1: epidemiology and diagnosis

Overuse injuries of the extensor mechanism of the knee are common in both athletes and non-athletes and usually occur during activities associated with repetitive loading, stress, and knee extension. Historically, they have been labeled as Jumper's knee due to the high prevalence seen in the athletic community. In many published reports, the name "patellar tendinopathy" is used to describe this disorder of the quadriceps tendon at the patellar insertion, and the names are often used interchangeably. Numerous reports have been published describing extensor mechanism injuries in athletes, but there is a paucity of studies that focus on quadriceps tendinopathy. In addition, there is no universally accepted classification system for tendon pathology. Therefore, we performed a comprehensive literature review of these studies. This review consists of 2 parts. In the first part we review: (I) epidemiology and (II) diagnosis of quadriceps tendinopathy in the athlete as well as the general population. In the second part we discuss: (I) classification; (II) prognosis; and (III) treatment results.

Use of an offset head center acetabular shell in difficult primary total hip arthroplasties

Several conditions may predispose patients to development of antero-lateral acetabular bone deficiency, including developmental dysplasia of the hip, osteonecrosis, or septic arthritis, among others. This may compromise the ability to gain acetabular component stability and impair reliable fixation. Large acetabular shells have often been used to achieve adequate fixation in scenarios of severe bone loss, however, these techniques have been shown to elevate the center of rotation (COR) of the hip and alter hip biomechanics. Recently, a new acetabular shell was developed with a goal of maintaining the native hip 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 with difficult hip pathologies. We have demonstrated how this offset COR acetabular shell may help bring down the COR of the hip in these quite challenging cases utilizing conventional techniques.

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.

The Role of Virtual Rehabilitation in Total and Unicompartmental Knee Arthroplasty

This study evaluated the use of telerehabilitation during the postoperative period for patients who underwent total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA). Specifically, this study evaluated the following: (1) patient compliance and adherence to the program, (2) time spent performing physical therapy exercises, (3) the usability of the virtual rehabilitation platform, and (4) clinical outcome scores in a selected primary knee arthroplasty cohort. A total of 157 consecutive patients underwent TKA (n = 18) or UKA (n = 139). These patients used a telerehabilitation system with an instructional avatar, three-dimensional motion measurement and analysis software, and real-time televisit capability designed for arthroplasty patients. Compliance was determined by how many times the patients followed prescribed repetitions of exercises. The total time spent performing exercises for each patient was collected. The usability of the virtual rehabilitation platform (on the patient's end) was evaluated using the system usability scale (SUS) questionnaire. The number of in-person and televisits was recorded for each patient. Patient-reported outcomes were collected through the patient and clinician interfaces and included the Knee Society Score (KSS) for pain and functions, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and Boston University Activity Measure for Post-Acute Care (AM-PAC) score. Patients spent an average of 29.5 days partaking in the therapy. TKA and UKA patients had a mean of 3.5 and 3.2 outpatient follow-up visits, each, for in-office therapy with a physical therapist, respectively. This figure exceeded the mean number of real-time virtual patient-clinician visits by 0.8 visits per patient in the TKA cohort and by 1 visit per patient in the UKA cohort. Patients spent on average 26.5 minutes per day conducting an average of 13.5 exercises. By the end of rehabilitation, patients had spent an average of 10.8 hours performing exercises, and of all the exercises performed, approximately 21 exercises were uniquely designed. Mean SUS score in the cohort was 93 points, which was interpreted as being above the 50th percentile point of the scale. Following therapy, KSS pain and function scores improved markedly and the improvements were measured at 368% for TKA and 350% for UKA (pain) and 27% for UKA and 33% for TKA (function). In addition, WOMAC scores improved by 57% and 66% for UKA and TKA patients while the improvement in AM-PAC scores was at 22% and 24%. This telerehabilitation platform encouraged clinician-patient interaction beyond the hospital setting and offers the advantage of cost savings, convenience, at-home monitoring, and coordination of care, all of which are geared to improve adherence and overall patient satisfaction. Additionally, the biometric data can be used to develop custom physical therapy regimens to assure proper rehabilitation, which is lacking in other telerehabilitation applications that use noninteractive videos that can be watched on mobile devices and tablets.

Impact of Intravenous Acetaminophen on Lengths of Stay and Discharge Status after Total Knee Arthroplasty

Postoperative pain remains difficult to control after total knee arthroplasty (TKA). While various modalities have been used, they have been associated with several side effects. For example, opioids have many side effects including: sedation, dizziness, nausea, vomiting, constipation, respiratory depression, and can lead to dependency. Recently, intravenous (IV) acetaminophen has been introduced as a method to manage postoperative pain. Therefore, the purpose of this study was to compare the postoperative outcomes of TKA patients who received oral acetaminophen versus IV acetaminophen. Specifically, this study evaluated: (1) the hospital lengths of stay (LOS) and (2) discharge dispositions. The Premier Database was used to review patients who underwent TKA from 2012 to 2015. A total of 134,216 TKA patients received oral acetaminophen, whereas 56,475 TKA patients received IV acetaminophen postoperatively. LOS were calculated as the number of days from the date of hospital admission to the date of discharge, and the discharge disposition was categorized as to home or to a skilled nursing facility (SNF). Compared with the oral group, the IV acetaminophen group had a 0.14 days shorter LOS (95% confidence interval [CI], -0.15 to -0.13; p < 0.001) and 22% higher chance of being discharged home (odds ratio [OR] = 1.22; 95% CI, 1.19-1.25; p < 0.001). Also, compared with the oral group, the IV group had a 13% lower chance of being discharged to a SNF (OR = 0.87; 95% CI, 0.85-0.90; p < 0.001). This study demonstrated that TKA patients who received IV acetaminophen were associated with a significantly shorter hospital LOS as well as being discharged home and fewer patients had to go to SNF. This may lead to a reduction in the total cost of health care, while, at the same time, decreasing the resource use in patients who undergo TKA.

A comparison of relative value units in revision hip versus revision knee arthroplasty

The purpose of this study was to compare the: 1) RVUs; 2) lengths-of-surgery; 3) RVU per minute between revision hip (THA) and knee (TKA) arthroplasties; and 4) perform an annualized surgeon cost analysis. Using the ACS-NSQIP from 2008 to 2015, 8081 revision TKAs, 7233 THAs were compared. Revision THA had greater mean RVUs (30.27 vs. 27.10 RVUs, p < 0.001), operative times (152 vs. 149 min, p < 0.001), and RVU/minute (0.3 vs. 0.2 RVUs per minute, p < 0.001). Cost analysis yielded and annual $89,922.73 difference. Revision THA, therefore, is reimbursed at a significantly higher "hourly rate," when compared to revision TKA.

Hip Osteoarthritis: A Primer

The objective of this article is to deliver a concise up-to-date review on hip osteoarthritis. We describe the epidemiology (disease distribution), etiologies (associated risk factors), symptoms, diagnosis and classification, and treatment options for hip osteoarthritis. A quiz serves to assist readers in their understanding of the presented material.

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.

Linear Wear Rates of a Highly Cross-Linked Polyethylene Hip Liner

INTRODUCTION

To help limit wear, newer polyethylene liners, such as the highly cross-linked polyethylene (HXLPE) liners, have been developed. These newer liners undergo an alternating irradiation process, resulting in a stronger, longer-lasting liner. The purpose of this study was to analyze the wear rates of patients who underwent THA and received a newer generation HXLPE acetabular insert. Specifically, we compared: 1) linear vector wear amount and 2) linear vector wear rates in patients as an overall cohort and by gender. We also assessed patient satisfaction outcomes comparing preoperative Harris Hip Scores (HHS) to seven-week, one-year, and three-year HHS scores.

MATERIALS AND METHODS

A total of 23 patients who underwent total hip arthroplasty (THA) with direct superior approach by a fellowship-trained orthopaedic surgeon at a private practice institution were analyzed after receiving institutional review board approval. Patients had a minimum two-year follow up, with the mean follow up being four years (range, three to five years). All patients received a 36-mm ceramic femoral head with an HXLPE liner. 2D radiographic polyethylene wear analysis was performed using the Martell Hip Analysis Suite (HAS; University of Chicago, Illinois), which has been previously validated in the literature. Outcomes were assessed using Harris Hip Scores.

RESULTS

A five-year linear wear rate of 0.073 mm/year (range, 0 to 0.160 mm/year) and an overall mean linear wear rate of 0.096 mm/year (range, 0 to 0.277 mm/year) were found. No significant differences in wear were seen between genders. Additionally, patients reported significantly better results at seven-weeks (83 points [range, 59 to 100 points]) and one-year (94 points [range, 85 to 100 points]) than preoperative (52 points [range, 34 to 73 points]) HSS scores (p<0.05). No patients underwent revision THA.

CONCLUSION

The results from this study highlight the benefits of using an HXLPE polyethylene liner in THA patients and further validates previously reported wear rates of HXLPE liners. After an early "wear in" period during the first year, the wear rates steadily decreased over time. This liner showed excellent early outcomes as no patients underwent revision THA. Furthermore, even as early as seven postoperative weeks, patients reported significantly better HHS scores. Future studies should track the same patient cohort over time to help develop a wear-rate prediction model.

Accurately Predicting Total Knee Component Size without Preoperative Radiographs

BACKGROUND

Preoperative templating of total knee arthroplasty (TKA) components can help in choosing appropriate implant size prior to surgery. While long limb radiographs have been shown to be beneficial in assessing alignment, disease state, and previous pathology or trauma, their accuracy for size prediction has not been proven. In an attempt to improve templating precision, surgeons have looked to develop other predictive models for component size determination utilizing patient characteristics. The purpose of this study was to: 1) Identify which patient characteristics influence the tibial and femoral component sizes; 2) Construct models for size prediction; 3) Test the generated models at five different centers; and 4) Compare implant survivorship and patient characteristics between those who did or did not receive an implant within one size of the prediction.

MATERIALS AND METHODS

Demographic data was collected on 741 patients (845 knees) as part of a multicenter clinical trial. Correlation between component size and patient demographic data were examined using Pearson coefficients, and significant variables were included into a multivariate-linear-regression model to determine "predicted size." Operative surgeon notes and postoperative radiographs were used to determine "actual size." Predictive equations were constructed for both femoral and tibial components and were tested at five different centers. Implant survivorship and patient characteristics were compared between those who did and did not receive an implant within one size of the prediction.

RESULTS

The strongest predictors of component size were height, weight, and gender (p<0.01), followed by ethnicity (p=0.03) and age (p=0.03). Predictive equations were constructed for both tibial and femoral components. The model predicted the component fit within one size in 94% (r2=0.68) and 96% (r2=0.73) of femoral and tibial components. Cases beyond ±1 sizes did not have notable device-specific adverse events with Kaplan-Meier survivorship of 100% at five years.

CONCLUSION

Demographic models are an effective tool in component size prediction prior to TKA. This model has implications in reducing the need for preoperative radiographic templating, potentially resulting in increasing surgeon efficiency and possibly reducing hospital implant inventory. This may be particularly important for ambulatory or outpatient surgery centers.

Operative Time, Length of Stay, Short-Term Readmission, and Complications after Hinged Primary Total Knee Arthroplasty: A Propensity Score Matched Analysis

Despite the wide utilization of total knee arthroplasty (TKA), it can be technically challenging to perform in patients who have concomitant bone loss, ligamentous laxity, or high-grade deformity, whether in a revision situation or due to a primary pathology. Therefore, hinged knee prostheses have been developed to provide more stable fixation in these situations. The purpose of this study was to compare the short-term peri- and postoperative outcomes of patients undergoing primary TKA with and without hinged prosthesis. Specifically, we compared (1) mean operative times, (2) lengths of stay (LOS), (3) 30-day readmissions, and (4) complications. The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify hinged TKAs and 99 procedures were included. They were matched in a 1:3 ratio to primary TKAs without a hinged prosthesis using propensity score matching. Operative time, LOS, discharge disposition, 30-day readmissions, and complications were compared. Adjusted odds ratios (OR) were also calculated. The operative time was significantly higher in hinged cohort compared with the nonhinged cohort (mean difference [MD] = 22 minutes; range, 10-34 minutes, p < 0.001). There were no significant differences between hinged and nonhinged TKAs with respect to LOS (MD= 0.61 days, range, -0.07-1.30 days, p = 0.080), discharge disposition (OR = 1.09, 95% confidence interval [CI], 0.66-1.84), readmissions (OR = 2.67, 95% CI, 0.84-8.24), and any complications (OR = 1.13, 95% CI, 0.55-2.19). Not surprisingly, primary TKAs with hinged prostheses had increased operative times, but had similar LOS, discharge dispositions, and 30-day rates of readmission and complications when compared with TKAs without a hinged prosthesis. One potential contributing factor to the increased operating time is that patients who receive a hinged implant tend to present with more severe deformities. It is reassuring to know that early outcomes were similar between both cohorts (although we await longer follow-up studies), and that hinged implants can be considered in these difficult to treat patients.