The Reverse Dorr: Preoperative radiographic evaluation of bone quality correlates to bone mineral density in total knee arthroplasty

Background

There has been an increase in cementless total knee arthroplasty (TKA) across the country. Although radiographic classification systems of the knee exist, these algorithms have not been correlated to bone mineral density (BMD). We aimed to correlate radiographic measurements of the knee with preoperative BMD and develop a model predictive of osteopenia.

Materials and methods

We prospectively enrolled 100 patients, scheduled to undergo elective TKA, to obtain a preoperative dual energy x-ray absorptiometry (DEXA) scan. Four independent surgeons measured cortical indices of the knee on preoperative radiographs and correlated these ratios with local BMD. Intraclass correlations (ICC) were used to assess interobserver reliability and Pearson correlation coefficients (PCC) to describe the strength of relationship between BMD and radiographic ratios. A "Reverse Dorr" model was created to evaluate the ratio of the distal femur cortical indices. Logistic regression was used to predict the odds of having osteopenia.

Results

We found several cortical ratios of the knee correlated with bone mineral density, but the lateral radiograph had the highest correlation. All measurements showed, at a minimum, fair interobserver reliability with most achieving an ICC >0.81. The proximal femur, distal femur ratio, "Reverse Dorr" model, was found to be a strong predictor of osteopenia with an ROC of 0.7335.

Conclusions

This radiographic assessment demonstrates that cortical thickness of the knee is correlated with bone mineral density-most notably on the lateral radiograph. Utilization of the "Reverse Dorr" model was strongly predictive of osteopenia and may help guide implant selection.

Risk factors for periprosthetic femoral fractures following hip arthroplasty: a systematic review and meta-analysis

INTRODUCTION

Periprosthetic femoral fracture (PPFF) is a serious complication following hip arthroplasty. The objective of this study was to determine the risk factors for PPFF following hip arthroplasty from existing studies.

METHODS

A comprehensive systematic search was performed in 4 databases: Pubmed, Embase, Web of Science, and Cochrane Library. The last search was carried out on 26th July 2024. We focused on identifying risk factors for PPFF following hip arthroplasty. Study eligibility required PPFF as an outcome and reporting of associated risk factors. Quality assessment was performed using the Newcastle-Ottawa Scale (NOS), with evidence certainty evaluated via Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Meta-analyses employed both fixed-effect and random-effects models to pool odds ratios for identified risk factors.

RESULTS

Out of 1553 articles, 36 studies published between 2006 and 2024 were included. Risk factors associated with increased incidence of PPFF ranges from very Low to High. High-quality evidence supported the use of uncemented stems (Odds Ratio [OR]: 3.36, 95% Confidence Interval [95% CI]: 3.02-3.74), major teaching hospital (OR: 2.04, 95% CI: 1.37-3.05). Moderate-quality evidence: female gender (OR: 1.60, 95% CI: 1.43-1.78), morbid obesity (OR: 1.44, 95% CI: 1.01-2.16), higher Deyo-Charlson index (OR: 1.44, 95% CI: 1.18-1.77), rheumatoid arthritis (OR: 1.89, 95% CI: 1.16-3.06), femoral Dorr type C (OR: 4.23, 95% CI: 2.82-6.33). Low evidence: age > 70 years (OR: 1.67, 95% CI: 1.19-2.34), revision hip arthroplasty (OR: 2.60, 95% CI: 1.59-4.27). BMI > 30 and history of hip surgery are not the risk (very low). Diagonized as osteoarthritis before surgery is a protective factor (OR:0.51, 95%CI: 0.40-0.65, quality = High).

CONCLUSION

This meta-analysis provided some low-to-high evidence about the risk of PPFF following hip arthroplasty. It's recommended that clinicians consider these risk factors when evaluating patients for hip arthroplasty and take steps to mitigate their impact, like optimizing patients health preoperatively, using cemented stems, and monitoring high-risk patients closely.

Use of augmented reality surgical navigation reduces intraoperative fluoroscopic imaging in anterior total hip arthroplasty with equivalent accuracy for component positioning

Background

Computer-assisted surgical navigation was designed to reduce the rates of acetabular component malpositioning, a common cause for revision following primary total hip arthroplasty (THA). We compared intraoperative measures such as radiation exposure, radiographic acetabular cup placement, and outcomes of patients who underwent a THA using computer-assisted surgical navigation with augmented reality (AR) compared to those who underwent traditional manual THA with fluoroscopic assistance (FA).

Methods

We retrospectively reviewed 115 hips who underwent primary direct anterior THAs using the intraoperative AR surgical navigation system between 3/30/2021 and 12/30/2022. These were compared to a matched cohort of 115 primary THAs performed with FA through a direct anterior approach during the same time period. Patients were matched based on age, gender, American Society of Anesthesiologists score (ASA), and BMI. Goal inclination and anteversion were set to 42° (°) and 22°, respectively.

Results

THA with AR patients had decreased intraoperative radiation exposure (mean 2.0 versus 3.2 mGy, p < 0.001) and radiation time (mean 0.2 versus 0.4 min, p < 0.001). Deviation from the preoperative plan was similar between AR and FA for both radiographic inclination and anteversion. There was no difference in the operative time, estimated blood loss, or reoperations, all of which were for infection (1.7 versus 0.0 %, p = 0.5).

Conclusion

AR surgical navigation in primary THA has similar radiographic, operative and clinical results as THA with intraoperative FA. However, AR surgical navigation is associated with decreased intraoperative fluoroscopic radiation and time. Further research is needed to evaluate accuracy of acetabular component positioning and complications.

Environmental impact of TKA: Waste audit of hospital operating room compared to ambulatory surgery center

Introduction

The implications of global warming are ever increasing in today's society. As the number of total knee arthroplasties (TKA) performed in the USA increases annually, the total waste produced from them will proportionally increase. This study hopes to quantify and compare the amount of waste created by a TKA in a hospital operating room (OR) and ambulatory surgery center (ASC) to evaluate for any differences in the amount and types of waste created.

Methods

Waste audits were performed on 10 TKAs both at hospital OR and ASC OR. Waste was organized into 6 categories: normal solid waste, recyclable plastics, biohazard waste, laundered linens, sharps, and polypropylene blue sterile wrap. Weight and volume for each waste stream were recorded using a digital scale and ruler.

Results

The total mass of waste produced was higher in hospital based TKAs than in the ASC cases (17.3 kg vs. 14.0 kg, p-value = 0.0028). There was significantly more mass of sterile, normal, and sharps waste at the hospital-based cases. Sterile waste was the largest contributor to the mass of waste in both settings. No difference existed in volume of waste between the hospital and ASC cases (305,866 cm3 vs 260,052 cm3, p-value = 0.2494).

Discussion

TKAs in both settings produce a large amount of waste. Performing TKAs at ASCs could be used to lower the amount of waste produced, resulting in long term benefits to both the environment and the healthcare system.

Direct anterior total hip arthroplasty after hip arthroscopy: A retrospective review

Introduction

Limited studies have investigated outcomes of total hip arthroplasty (THA) after ipsilateral hip arthroscopy, with mixed conclusions. There is need to provide clarity on potential risks/complications associated with this sequence of operations.

Methods

This is a retrospective single surgeon cohort study, evaluating patients from 01/01/2012-01/01/2020 undergoing direct anterior THA for osteoarthritis, with minimum 90-day follow-up. There were two groups: previous hip arthroscopy plus THA (THA+) and isolated THA (control) without previous hip arthroscopy. All THA + patients had undergone one previous hip arthroscopy prior to THA. Quantitative variables were evaluated using the Mann-Whitney-U test or a two-tailed unpaired t-test. Nominal variables were evaluated using the chi-square or Fisher's Exact test. Significance was assessed at p < 0.05.

Results

Seventy-one patients were included, 38 patients in the THA + group, and 33 patients in the control group. Surgery duration was longer in the THA + group (74 min THA + [SD = 9.5], 60 min control [SD = 11.3], p < 0.0001). The only secondary outcome with significance was average estimated blood loss (400 mL THA+, 275 mL control, p = 0.009). Only one THA + patient required postoperative transfusion (p = 1.0). There were no postoperative deep infections requiring debridement, intra-operative fractures requiring fixation, or postoperative dislocations in either group. The THA group had one post-operative fracture requiring surgery. The THA + group was younger (average) than the control group (52 THA + [SD = 9.9], 58.4 control [SD = 8.8], p = 0.0062).

Conclusion

This study highlights increased operative time and estimated blood loss after previous ipsilateral hip arthroscopy. Surgeons should recognize implications on time management, and assist surgeons when deciding to perform a THA at a surgery center vs hospital. These results contribute to a growing body of literature indicating no increase in major complication rate of THA after ipsilateral hip arthroscopy.

Causative factors for varus tibial baseplate subsidence in primary total knee arthroplasty: A retrospective analysis

Background

In this retrospective study, the focus was on identifying potential causative factors associated with varus subsidence of the tibial component in primary total knee arthroplasty (TKA). The research aimed to investigate the risk factors contributing to aseptic varus tibial baseplate subsidence (VTBS) leading to revision TKA procedures.

Patients and methods

A total of 120 patients with documented VTBS complications post-TKA were compared with a control group of 52 patients. Factors such as patient demographics, surgical data and comorbidities were included. The study also explored the Coronal Plane Alignment of the Knee (CPAK) classification pre- and post-operatively to understand its implications on varus subsidence.

Results

Significant differences noted in the VTBS group in variables including younger patient age (P=<0.001), increased BMI (P = 0.003), larger proportion of patients with tibial component oversize or undersizing (P=<0.001), less tibial stem extensions used (P < 0.001), higher CCI (P < 0.001) and a higher proportion of patients in CPAK group 2 (P = 0.044).

Conclusion

This investigation provides valuable insights into potential risk factors for VTBS, aiming to optimize patient outcomes and assist in preventing complications associated with TKA procedures.

Physical functioning before knee arthroplasty is not associated with (standardized) preoperative physiotherapy, but is tied to physical functioning 1-year post-surgery: A prospective cohort study

Background

and purpose This study investigates whether a (regionally) standardized physiotherapy approach, employing a stepped-care model, can more effectively enhance preoperative physical function in end-stage osteoarthritis (OA) patients undergoing total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) and improve postoperative outcomes, addressing the current gap in understanding the impact of such interventions.

Methods

This mono-center observational prospective cohort study followed 216 primary UKA or TKA patients for one-year post-surgery. Preoperative physiotherapy, recorded through self-reported questionnaires, included standardization and treatment frequency details. Physical functioning assessments encompassed quadriceps and hamstrings muscle strength, functional mobility (FM), and range of motion (ROM). Statistical analyses comprised multivariate and single linear regression for both UKA and TKA groups.

Results

Standardized preoperative physiotherapy correlated with superior preoperative extension ROM in TKA patients (B = -3.557, 95 % CI [-.915; -.241]), while less than 10 treatments were associated with superior preoperative extension ROM for both groups (β = -.202, p = .030 and β = -.228, p = .045). No associations were found between location or treatment frequency and preoperative muscle strength or FM. For both groups, preoperative FM, ROM, and muscle strength positively correlated with postoperative levels, except for extension ROM for UKA patients (p = .178).

Conclusion

While adherence to standardized preoperative physiotherapy at an affiliated practice did not significantly correlate with preoperative physical functioning levels, a strong relationship exists between preoperative and one-year postoperative physical functioning levels.

Periprosthetic osteolysis: Mechanisms and potential treatment strategies

Periprosthetic osteolysis is a common bone-related disorder that often occurs after total hip arthroplasty. The implants can cause damage to bone and bone-related cells due to mechanical stress and micromotions, resulting in the generation of a large number of wear particles. These wear particles trigger inflammation and oxidative stress in the surrounding tissues, disrupting the delicate balance maintained by osteoblasts and osteoclasts, ultimately leading to bone loss around the implant. Clinical investigations have demonstrated that Epimedium prenylflavonoids, miR-19a-3p, stem cell-derived exosomes, and certain non-PPO category pharmaceuticals have regulatory effects on bone homeostasis through distinct molecular pathways. Notably, this phenomenon reflects inherent biological rationality rather than stochastic occurrence. Extensive research has revealed that multiple natural compounds, non-coding RNAs, exosomes, and non-PPO therapeutics not only exert modulatory influences on critical pathophysiological processes including inflammatory cascades, oxidative stress responses, and tissue regeneration mechanisms, but also effectively regulate bone-related cellular functions to inhibit PPO progression. Therefore, this review comprehensively and systematically summarizes the main pathogenic mechanisms of periprosthetic osteolysis. Furthermore, it delves deeper into the research progress on the applications of currently reported natural products, ncRNAs, exosomes, and non-PPO medications in the treatment of periprosthetic osteolysis. Based on this, we hope that this paper can provide new perspectives and references for the future development of drugs targeting periprosthetic osteolysis.

Enhancing Calcium Phosphate Cements: A review of Bacterial Cellulose (BC) and other Biopolymer Reinforcements for Biomedical Applications

Calcium phosphate cements (CPCs) are renowned for their biocompatibility and osteoconductivity, making them ideal for bone tissue engineering. However, their brittleness and low tensile strength limit their use in load-bearing applications. Bacterial cellulose (BC) has emerged as a promising reinforcement material due to its high tensile strength, biocompatibility, and biodegradability. The incorporation of 2 wt% BC into CPCs increased compressive strength from 5 MPa to 12 MPa, representing a 2.4-fold enhancement, while also improving toughness and promoting cellular interactions through its nanofibrillar structure. Additionally, hybrid composites combining BC with collagen, chitosan, or polycaprolactone (PCL) exhibit synergistic effects, further enhancing mechanical properties and biodegradability. These advancements highlight the potential of BC-reinforced CPCs for clinical applications in bone repair and regeneration. Despite these improvements, limited research addresses tensile and flexural properties, which are critical for load-bearing applications, as well as the effects of BC on injectability and setting time for minimally invasive procedures. Emerging innovations, such as electroactive BC-reinforced CPCs for stimulating bone healing, hold significant potential but remain underexplored. Future research should focus on optimising mechanical properties, validating clinical performance, and developing hybrid formulations to expand their use in load-bearing bone repairs.

Comparing patient outcomes following outpatient total joint arthroplasty in a hospital setting versus an ambulatory surgery center

Background

Traditionally, total joint arthroplasty has been performed as an inpatient procedure, sometimes requiring a hospital stay of a few days. However, outpatient total joints have gained popularity in recent years. The purpose of this study is to compare patient outcomes following an outpatient total knee arthroplasty (TKA) or a total hip arthroplasty (THA) in a hospital setting versus an ambulatory surgical center.

Method

This study was a prospective study of patients receiving either a TKA or THA, with results up to one year. All cases were performed by one board certified orthopedic surgeon. Each of the patients routinely completed patient reported outcome measures at the preoperative and postoperative visits for up to one year postoperatively.

Results

At three-month follow-up, there were no observed differences in the PROMIS, KOOS Jr, HOOS Jr, Oxford Hip, Oxford Knee, or mHHS scores between the cohorts. At one-year follow-up, there were no statistical differences in any PROMs between the ASC and hospital cohorts. In addition, subgroup analysis was performed comparing PROMs between patient's based on specific subgroups: diabetics, BMI >30, BMI<30, gender, and age, which showed non-statitistical differences at one year.

Conclusion

We believe that this study confirms that same day discharge, outpatient total joint procedures can be performed safely and effectively from either the hospital or ASC setting. While there were some differences in perceived outcomes at 3-months for some subgroups, these were not statistically significant at the 1-year after follow-up.

Patient specific variables impact sensitivity to association between joint balance and 2 Year outcomes

Background

This study investigates the association between intra-operative balance and 2-year outcomes within subgroups defined by demographics and pre-operative joint balance. Our hypothesis is that patient demographics and the pre-operative state of the joint will impact patient sensitivity to post-operative balance and laxity and subsequent impact on outcome.

Methods

A retrospective analysis of prospectively captured data across 5 sites with 5 surgeons was performed. All cases completed pre-operative demographics surveys, 2-year post-operative Knee Injury and Osteoarthritis Outcome Score (KOOS) and had a robot assisted total knee arthroplasty with an integrated digital joint balancing tool. Differences in associations between intra-operative final joint balance and 2-year KOOS pain outcomes in demographic and pre-operative balance subgroups were characterized. Associations informed clinically relevant thresholds to optimize TKA treatment for subgroups.

Results

A total of 276 patients completed 2-year KOOS scores. Subgroups were defined from Sex, Age, BMI and pre-operative extension laxity. Men prefer a tight tolerance medially in extension and mid-flexion while females prefer a tight lateral flexion gap. Patients <70 years show a strong preference for equal rectangular gaps in extension, mid-flexion, and flexion, while older patients do not show a preference. Patients with BMI ≤30 demonstrate a preference for rectangular gaps, while patients with higher BMI do not. Finally, patients with looser pre-operative extension laxity (>3 mm) preferred a TKA with increased extension laxity compared to patients with minimal preoperative laxity.

Conclusion

Intraoperative differences in knee balance can influence patient outcome scores among different demographic groups at two years postoperatively. This suggests further research is warranted to determine how ligament balance and laxity may be optimized based on individual patient factors.

Imaging near titanium total hip arthroplasty at 0.55 T compared with 3 T

PURPOSE

To compare 0.55 T and 3 T MRI for imaging patients with titanium total hip arthroplasty (THA). Patients with orthopedic metallic implants often require diagnostic imaging to evaluate adjacent tissues. MRI performance measures, including artifact levels and SNR, vary with field strength.

METHODS

Six patients with titanium THA were scanned with similar protocols at 0.55 T and 3 T, including proton density (PD) weighted turbo spin echo (TSE), PD TSE with view-angle tilting (TSE + VAT), PD slice encoding for metal artifact correction (SEMAC), and short tau inversion recovery with SEMAC (STIR-SEMAC). Images from both field strengths were scored by two readers and qualitatively and quantitatively compared.

RESULTS

Diagnostic confidence was significantly higher at 0.55 T compared to 3 T. Perceived metal artifact was substantially reduced at 0.55 T compared to 3 T. At 0.55 T, diagnostic imaging was achieved both without and with multi spectral imaging (MSI) for PD weighted images.

CONCLUSION

Compared to 3 T, 0.55 T MRI offers substantially reduced metal artifacts and higher diagnostic confidence when imaging titanium THA. Advanced multi-spectral techniques may not be required when the metallic components are entirely titanium.

Total Hip Arthroplasty After Gunshot-Related Hip Injuries: Case Series and Review of Literature

High-velocity penetrating trauma to the hip can result in complex acetabular and femoral head fractures, often accompanied by vascular injuries and extensive soft tissue damage. Managing these injuries presents significant challenges due to contamination, bone loss, and the need for staged reconstruction. In 2 cases of severe ballistic and blast injuries, initial damage control measures included debridement, stabilization, and temporary antibiotic spacers to control infection risk. Delayed definitive total hip arthroplasty was performed after optimizing soft tissue and bony healing, leading to full functional recovery. This approach highlights the importance of staged reconstruction and multidisciplinary management in achieving successful outcomes in high-energy hip injuries.

Effects of Malnutrition on Perioperative Outcomes of Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

Background

Malnutrition can play a significant role in wound healing, immune response, and conditioning. The purpose of this review is to characterize definitions of malnutrition in total hip arthroplasty (THA) and analyze its effects on postoperative outcomes.

Methods

A systematic search was conducted using iterations of the key terms "total hip arthroplasty" and "malnutrition." Human studies describing malnutrition in patients undergoing primary THA for either traumatic or elective indications were included. Using the SPSS meta-analysis binary and continuous model function, the mean effect size estimate (MSE) or Cohen's d (Cd) statistic with 95% confidence interval was reported.

Results

This search yielded a total of 555 studies, of which 9 articles comprising 495,657 patients undergoing primary THA were included, characterizing 16,895 patients (3.4%) as malnourished. Studies characterized malnutrition as albumin <3.5 g/dL (n = 7) and total lymphocyte count <1500 (n = 1). Malnutrition was associated with an increased rate of nonhome discharge (MSE = 0.81, [0.55-1.07]) and likelihood of readmission (MSE = 0.86, [0.75-0.97]). Malnutrition at the time of surgery was also associated with increased rates of any complication (MSE = 1.01, [0.46-1.57]), wound complications (MSE = 1.04, [0.72-1.36]), pulmonary complications (MSE = 1.54, [1.29-1.78]), need for transfusion (MSE = 0.75, [0.54-0.96]), periprosthetic fracture (MSE = 0.65, [0.47-0.82]), reoperation (MSE = 0.72, [0.58-0.86]), and perioperative mortality (MSE = 2.05, [1.76-2.33]).

Conclusions

Malnutrition was found to have significant associations with complications and disposition following THA. The findings from this meta-analysis provide support for further investigation into perioperative nutritional supplementation strategies for surgeons to optimize at-risk patients prior to THA.

Level of Evidence

III.

Simulation-based learning in orthopaedics: q s r

Introduction

Simulation-based learning has emerged as a transformative tool in orthopaedic education, significantly improving surgical training and patient safety. This systematic review examines the role of simulation in enhancing technical skills, decision-making, and clinical competence among orthopaedic trainees.

Methods

A systematic review was conducted to assess the effectiveness of simulation-based training in orthopaedics. Various simulation modalities, including virtual reality (VR), augmented reality (AR), haptic feedback systems, and task-based trainers, were analyzed for their impact on skill acquisition and retention. The study was registered with PROSPERO (ID: CRD420250652679).

Results

Key findings suggest that simulation-based training leads to reduced surgical errors, faster learning curves, and better skill retention. However, challenges such as high costs, limited access to advanced simulation tools, and difficulties in integrating these technologies into traditional curricula persist.

Conclusion

Simulation is expected to play a crucial role in modernizing orthopaedic education by providing safe, repeatable practice opportunities. Future directions include AI-driven training modules and collaborative VR platforms to further enhance training efficacy and patient outcomes.

The Prediction of Venous Thromboembolism Using Artificial Intelligence and Machine Learning in Lower Extremity Arthroplasty: A Systematic Review

Background

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a common and serious complication following lower extremity arthroplasty, such as total hip and knee arthroplasty. Due to the increasing number of these surgeries, accurately predicting VTE risk is crucial. Traditional clinical prediction models often fall short due to their complexity and limited accuracy.

Methods

This Preferred Reporting Items for Systematic Review and Meta-Analyses-guided systematic review summarized the application of artificial intelligence (AI) and machine learning models in predicting VTE after total joint arthroplasty. Databases including PubMed, Scopus, Web of Science, and Embase were searched for relevant studies published up to January 2024. Eligible studies focused on the predictive accuracy of AI algorithms for VTE post arthroplasty and were assessed for quality using the Newcastle-Ottawa Scale.

Results

A total of 7 retrospective cohort studies, encompassing 579,454 patients, met the inclusion criteria. These studies primarily employed the extreme gradient boosting model, which generally demonstrated strong predictive performance with area under the curve values ranging from 0.71 to 0.982. Models like random forest and support vector machines also performed well. However, only 1 study included external validation, critical for assessing generalizability.

Conclusions

AI and machine learning models, particularly extreme gradient boosting, exhibit significant potential in predicting VTE after lower extremity arthroplasty, outperforming traditional clinical prediction tools. Yet, the need for external validation and high-quality, generalizable datasets remains critical before these models can be widely implemented in clinical practice. The study underscores the role of AI in preoperative planning to enhance patient outcomes in orthopaedic surgery.

State Healthcare Regulations and Total Knee Arthroplasty Prices Across the United States

Background

The cost of healthcare services in the United States is subject to various regulatory influences, yet the impact of state-level healthcare policies and political affiliations on total knee arthroplasty (TKA) prices remains underexplored.

Methods

Using data from the Turquoise Health Database and publicly available sources, TKA prices were analyzed across states to examine the influence of Medicaid expansion, Certificate of Need (CON) laws, and state partisan lean. Multivariable regression models controlled for Gross Domestic Product per capita, Area Deprivation Index, and urbanization.

Results

Among 64,402 TKAs from 2455 hospitals ($18,164 median, interquartile range: $10,806), states with Medicaid expansion and CON laws demonstrated lower TKA prices. Republican-leaning states had significantly reduced TKA prices compared to Democrat-leaning states, even after adjusting for economic factors (P < .0001).

Conclusions

Medicaid expansion and CON laws were associated with lower TKA prices across the United States. Additionally, states with Republican political leanings tended to have lower listed prices for TKA compared to Democrat-leaning states. These findings underscore the substantial influence of state healthcare policies and political factors on healthcare costs, highlighting the complexities of pricing dynamics in the US healthcare system.

Level of evidence

IV.

The effects of combining electrical stimulation of the calf and thigh muscles on WOMAC pain in knee osteoarthritis: A double-blind, randomised, sham-controlled trial

Objective

To explore the effectiveness of a NMES device in improving pain and function for individuals with KOA.

Method

This was a randomised, sham-controlled, superiority trial recruiting individuals with symptomatic KOA, with both participants and outcome assessors blinded to the treatment allocation. Participants were randomised to receive either self-administered NMES, consisting of quadriceps (5 times a week) and footplate stimulation (7 times a week), or a sham device for 8 weeks. The primary outcome was the change in Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain domain at week 8.

Results

179 participants were randomised; 50.8 ​% female, mean (SD) age 66.9 (8.7) years. 164 attended the follow up visit. No difference in the WOMAC pain domain was seen between groups (-0.7; 95 ​% CI: -1.5, 0.1; P ​= ​0.10), though within group improvements were reported in both groups (NMES: -1.5; 95 ​% CI: -2.0, 0.8; P ​< ​0.01, sham: -0.8; 95 ​% CI: -1.4, 0.2; P ​< ​0.01). There were no differences in strength, exercise and functional capacity, swelling, health related quality of life or anxiety and depression between groups. Sub-group analysis for NMES compliance or recruitment source did not change response in primary outcome.

Conclusion

Use of an NMES device on the quadriceps and plantar flexors did not enhance pain relief or improve function over the sham control in people with KOA.

Early Failure of a Novel Modular Dual Mobility Liner After Metal Release: Clinical Presentation and Detailed Retrieval Analysis

Cobalt chrome alloy (CoCrMo) corrosion and subsequent metal release has been described as a potential complication of total hip arthroplasty. Here, we present the case of a patient with a well-seated dual mobility (DM) implant revised after 10 months. Prior to revision, the patient experienced pain and stiffness. Following a negative infection workup, we measured elevated metal concentrations, hypothesized to originate from the CoCrMo DM liner. While corrosion has been extensively reported in other constructs, the CoCrMo liner described here includes a post and tabs, features added to reduce the risk of corrosion. Retrieval analysis demonstrated a severe chemically based corrosion attack on the liner. Continued caution and ongoing close monitoring of outcomes associated with the use of modular DM constructs is likely warranted.

Lateral Instability 13 Years After Kinematically Aligned Total Knee Arthroplasty

To reduce unsatisfied patients following total knee arthroplasty (TKA), kinematic alignment has been introduced as an alternative to mechanical alignment. Studies have shown no significant differences in functional outcomes and early revision rates between alignment strategies. This case report presents a 64-year-old patient who developed progressive varus alignment and lateral instability 13 years after a kinematically aligned TKA. The case highlights the impact of varus alignment on the risk of medial plastic wear and lateral soft tissue attenuation. Both can contribute to lateral instability, a lateral thrust, and progressive varus deformity in unrestricted kinematic alignment TKA. This article suggests that excessive varus alignment should be avoided and restricted alignment targets should be considered when using kinematic, or functional alignment in TKA for varus osteoarthritis.

Improved Efficiency and Intraoperative Planning With 1 Robot-Assisted Total Knee Arthroplasty System

Background

Robotic-assisted total knee arthroplasty (rTKA) has garnered significant interest for its potential to enhance surgical precision and accuracy. However, the adoption of such systems poses concerns, including longer operative times and learning curves, potentially reducing efficiency. This study aimed to evaluate the learning curve associated with the Robotic Surgical Assistant (ROSA) system for rTKA.

Methods

This retrospective review analyzed the first 75 ROSA rTKA procedures performed by each of 2 fellowship-trained arthroplasty surgeons (150 total procedures) at a high-volume institution. Time stamps within the robotic software were recorded for each case, along with tourniquet time. Statistical analyses included descriptive statistics, t-tests, and multilevel regression.

Results

Comparison of each surgeon's first 20 and last 20 cases revealed significant decreases in tourniquet time (61.4-56.7 minutes; P = .0417) and planning time (13.49-6.68 minutes; P = .0078). Landmark femur and tibia times remained stable (P = .6542 and P = .9440). Knee state evaluation time showed a trend of reduction from 9.22 to 7.33 minutes (P = .1335), and resection time from 13.66 to 12.92 minutes (P = .4372). Regression analysis indicated significant reductions in tourniquet time (β = -0.11; P = .0089) and planning time (β = -0.08; P = .0064).

Conclusions

This study demonstrates that execution of ROSA rTKA becomes more efficient over the first 75 cases. The greatest improvement with experience is the time spent on the planning panel, the cognitive portion of the procedure. These data provide surgeons with the confidence that the technical portions of the case are quick to learn and guide industry to focus on teaching effective adjustments on the planning panel.

Adductor canal block in total knee arthroplasty: a scoping review of the literature

Background

An adductor canal block is commonly used to reduce pain after total knee arthroplasty. Practice varies in terms of site of injection, local anaesthetic, and adjuncts used, with poor consensus in relation to the best approach. The aim of this scoping review was to assess the evidence for efficacy and safety of adductor canal block, determine variation in the technique used, type and dose of medication, and compare the efficacy of adductor canal block with other nerve block techniques.

Methods

Four databases were searched to identify relevant studies (Medline, Embase, Cochrane, and ClinicalTrials.gov). A total of 285 articles were found, and data was extracted from 130 randomised controlled trials.

Results

Adductor canal block is a safe and potentially effective peripheral nerve block for reducing postoperative pain after total knee arthroplasty while preserving motor function. Of all adjuncts to adductor canal block assessed, either dexamethasone or dexmedetomidine provide additional analgesic benefit. Adductor canal block combined with peri-articular local anaesthetic injection provides the best outcomes. Continuous infusion of local anaesthetic through a catheter placed in the adductor canal provides no additional benefit over a single injection. The site of injection used for adductor canal block does not seem to affect efficacy. There was no evidence to support the superiority of any single local anaesthetic agent.

Conclusion

This scoping review has identified variation in the use of medications, doses, techniques, and adjuncts for adductor canal block. As such, definitive conclusions regarding the most effective practice for adductor canal block cannot be made.

Utilization of Machine Learning Models to More Accurately Predict Case Duration in Primary Total Joint Arthroplasty

BACKGROUND

Accurate operative scheduling is essential for the appropriation of operating room esources. We sought to implement a machine learning model to predict primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) case time.

METHODS

A total of 10,590 THAs and 12,179 TKAs between July 2017 and December 2022 were retrospectively identified. Cases were chronologically divided into training, validation, and test sets. The test set cohort included 1,588 TKAs and 1,204 THAs. There were four ML algorithms developed: linear ridge regression (LR), random forest, XGBoost, and explainable boosting machine. Each model's case time estimate was compared to the scheduled estimate measured in 15-minute "wait" time blocks ("underbooking") and "excess" time blocks ("overbooking"). Surgical case time was recorded, and SHAP values were assigned to patient characteristics, surgical information, and the patient's medical condition to understand feature importance.

RESULTS

The most predictive model input was "median previous 30 procedure case times." The XGBoost model outperformed the other models in predicting both TKA and THA case times. The model reduced TKA 'excess time blocks' by 85 blocks (P < 0.001) and 'wait time blocks' by 96 blocks (P < 0.001). The model did not significantly reduce 'excess time blocks' in THA (P = 0.89) but did significantly reduce 'wait time blocks' by 134 blocks (P < 0.001). In total, the model improved TKA operative booking by 181 blocks (2,715 minutes) and THA operative booking by 138 blocks (2,070 minutes).

CONCLUSIONS

Machine learning outperformed a traditional method of scheduling total joint arthroplasty cases. The median time of the prior 30 surgical cases was the most influential on scheduling case time accuracy. As ML models improve, surgeons should consider ML utilization in case scheduling; however, prior 30 surgical cases may serve as an adequate alternative.

Increasing Utilization of Extended Oral Antibiotic Prophylaxis Following Total Knee Arthroplasty From 2010 to 2022

BACKGROUND

Extended oral antibiotic (EOA) prophylaxis has been shown to reduce rates of periprosthetic joint infection in high-risk patients following total knee arthroplasty (TKA). Although national societies' recommendations against their use and clinical efficacy remain controversial, the increase in the literature surrounding EOA prophylaxis suggests a potential change in practice patterns that may warrant the creation of national guidelines. The purpose of this study was to investigate the trends in the utilization of EOA prophylaxis following TKA from 2010 to 2022.

METHODS

Patients who underwent primary or aseptic revision TKA between 2010 and 2022 were identified in a national administrative claims database. Temporal trends in EOA usage following primary or revision TKA were calculated, and secondary analysis examined rates of utilization across demographics, including patients considered at high risk for infection. In total, 1,258,759 primary and 91,530 aseptic revision TKA patients were included in this study.

RESULTS

From 2010 to 2022, EOA prescriptions increased by 321 and 368% following primary and revision TKA, respectively. Rates of utilization among high-risk individuals were similar to those of the general population.

CONCLUSIONS

The use of EOA prophylaxis after TKA has increased significantly since 2010. Given their increasing usage and variation in prescription patterns among patients at high risk of infection, guidelines surrounding their use are necessary to promote antibiotic stewardship while preventing rates of infection.

A Proposed Patient Selection Algorithm for Total Joint Arthroplasty Same-Day Discharge From an Ambulatory Surgery Center

BACKGROUND

Identifying appropriate patients for same-day discharge (SDD) total joint arthroplasty (TJA) is critical for maintaining optimal patient safety and outcomes. This study investigated patient outcomes after SDD TJA at a single ambulatory surgery center (ASC) and proposes a TJA patient-selection algorithm based on findings and existing literature.

METHODS

A retrospective chart review of 660 patients was performed between July 2019 and October 2021 for all patients who underwent primary TJA in a single ASC. Successful SDD, length of surgery, estimated blood loss (EBL), complications, and readmission events were recorded for each patient. There were 20 total complications in 331 primary total knee arthroplasties (TKAs) (6.0%) and 15 total complications in 329 primary total hip arthroplasties (THAs) (4.6%).

RESULTS

There was one direct admission to the hospital in TKA patients and four direct admissions in THA patients, making the successful SDD rate 99.7% in TKAs, 98.8% in THAs, and 99.2% overall. In the TKA cohort, body mass index was associated with total complications (r = -0.15, P = 0.006); comorbidities with wound complications (P = 0.006); and EBL was with readmissions (r = 0.30, P < 0.001), revision surgery (r = 0.12, P = 0.04), and total complications (r = 0.16, P = 0.03). In the THA cohort, body mass index was weakly associated with wound complications (r = -0.12, P = 0.02), EBL was with emergency department visits (r = 0.18, P = 0.002) and total complications (r = 0.14, P = 0.01). However, there was no direct association between any of the analyzed characteristics and direct admission.

CONCLUSIONS

In our ASC cohort, patients had low rates of perioperative complications and hospital admissions, supporting the safety of SDD TJA using our proposed evidence-based algorithm to guide patient selection for SDD.

Low-Volume Surgeons Operating at High-Volume Hospitals Have Low Rates of Periprosthetic Joint Infection After Hip and Knee Arthroplasty

BACKGROUND

The relationship between surgeon and hospital case volumes and postoperative risk following total hip arthroplasty and total knee arthroplasty (THA and TKA) has been described independently. This study aimed to assess the risk of periprosthetic joint infection (PJI) following primary TKA and THA to determine if lower volume surgeons operating at higher volume centers would have lower rates of complications compared to lower volume surgeons operating at lower volume hospitals.

METHODS

A health care database was used to retrospectively identify all primary and elective total joint arthroplasties from October 2015 to December 2021. Using restricted cubic splines, high-volume hospitals were defined using Markov chain Monte Carlo simulation, which identified a volume beyond which PJI rates no longer decreased significantly with increasing hospital volume. A similar methodology was used to identify low-volume surgeons operating in high- and low-volume hospitals. There were 605,254 patients who underwent total joint arthroplasty (THA: 37.71%; TKA: 62.29%) by low-volume surgeons (< 57 THAs and < 68 TKAs) identified and divided into high- and low-volume hospital cohorts. High-volume hospitals were defined as > 508 THA and > 812 TKAs per year, and low-volume hospitals were defined as < 145 THAs and < 243 TKAs per year. Multivariable models accounting for potential confounding covariates were created to determine the odds of PJI between cohorts.

RESULTS

After taking confounding variables into account, low-volume surgeons at high-volume hospitals had lower rates of PJI relative to their counterparts at low-volume hospitals (THA 0.67 versus 0.80%, adjusted odds ratio = 0.69 [95% confidence interval = 0.54 to 0.88], P = 0.002; TKA 0.51 versus 0.69%, adjusted odds ratio = 0.73, [95% confidence interval = 0.61 to 0.87], P = 0.007).

CONCLUSIONS

Increasing institutional case volume may mitigate the increased risk of PJI associated with low annual surgeon case volume.

Variability in the classification, management, and outcome reporting for avascular necrosis of the femoral head: A systematic review

Introduction

There is no universally-utilized classification system for avascular necrosis of the femoral head (AVNFH), a debilitating condition that arises due to impaired blood supply resulting in cortical collapse. AVNFH may require early intervention to prevent irreversible damage leading to total hip arthroplasty. The purpose of this study is to assess the variability in classification, management, and outcomes reported in randomized controlled trials (RCTs) related to AVNFH.

Methods

PubMed, Embase, and Medline were queried for RCTs on the treatment of AVNFH (2010-2023). The number of patients, number of femoral heads, minimum follow-up, AVNFH classification system, treatment interventions, and outcome measures were extracted. Variability in classification, management approach, and reporting of outcomes was evaluated.

Results

A total of 30 RCTs met inclusion criteria, encompassing 1891 total patients. The mean number of patients in each study was 63 (SD = 41), with a mean minimum follow-up of 30 months (SD = 17). The Association Research Circulation Osseous classification system was utilized in 63 % (n = 19) of studies, Ficat and Arlet in 20 % (n = 6) of studies, Steinberg in 10 % (n = 3), Mitchell in 3 % (n = 1), and the China-Japan Friendship Hospital classifications in 3 % (n = 1). There were 61 treatment interventions, stratified into nine categories. Radiographic imaging was most commonly used to evaluate patients at follow-up.

Conclusion

There are a variety of classification systems, treatments, and outcome measures utilized in the literature to categorize and quantify AVNFH. The utilization of a universally-accepted classification system and standardized outcome reporting may help to ensure reproducibility and accuracy given a continued lack of consensus.

The Utility of Neighborhood Social Vulnerability Indices in Predicting Non-Home Discharge Disposition Following Revision Total Joint Arthroplasty: A Comparison Study

BACKGROUND

Identifying risk factors associated with non-home discharge (NHD) following revision hip and knee total joint arthroplasty (TJA) could reduce the rate of preventable discharge to rehabilitation or skilled nursing facilities. Neighborhood-level deprivation indices are becoming an increasingly important measure of socioeconomic disadvantage as these indices consider multiple social determinants of health. This study aimed to compare the utility of widely used neighborhood social vulnerability indices in predicting NHD following revision TJA patients.

METHODS

This study included 1,043 consecutive patients who underwent revision TJA at a single tertiary health system. There were three multivariate logistic regression analyses with the outcome of NHD performed using the area deprivation index (ADI), social deprivation index (SDI), and social vulnerability index while controlling for other demographic variables. Neighborhood-level indices were included in the analysis as continuous variables and categorical quartiles, with the lowest quartile representing the least deprived neighborhoods of the patient cohort. The strength of the association of significant indices was measured.

RESULTS

Patients in the highest ADI and SDI quartiles demonstrated higher odds of NHD compared to the cohort with the lowest quartile (ADI OR [odds ratio] = 1.93, 95% CI [confidence interval] = 1.23 to 3.03, P = 0.005; SDI OR = 1.86, 95% CI = 1.18 to 2.91, P = 0.007). Discharge disposition was more strongly associated with ADI than SDI (0.68 versus 0.26). Age, American Society of Anesthesiologist status, and alcohol use were independent determinants of discharge disposition. No significant association was seen between social vulnerability index and discharge disposition.

CONCLUSIONS

Area-level indices can be utilized to identify patients at higher risk of NHD following revision TJA. This study highlights the important differences between these indices' utility when evaluating their effects on clinical outcomes in this patient population. The findings shed light on the potential of integrating these tools into policy development, clinical preoperative programs, and research to better understand and address the health disparities in arthroplasty outcomes.

Does Body Mass Index Affect the Success of Two-Stage Management of Periprosthetic Joint Infection?

BACKGROUND

Obesity is associated with increased infection risk after primary total joint arthroplasty. In this retrospective cohort analysis, we sought to assess the association between body mass index (BMI) and infection recurrence after two-stage revision total joint arthroplasty for periprosthetic joint infection (PJI).

METHODS

Patients were grouped by BMI (< 30, 30 to 40, and ≥ 40) as non-obese, obese, and morbidly obese, and assessed for associations and timing of PJI reinfection as well as readmissions and complications.

RESULTS

Following the two-stage revision, PJI reinfections increased from 11.5% in nonobese to 19.0% in obese and 25.9% in morbidly obese patients (P = 0.011). As BMI increased across the three groups, 90-day readmission rates following two-stage PJI revision significantly increased (8.6, 19.7, and 16.7%, respectively (P = 0.042)). The average time to reinfection decreased with obesity tercile (restricted-mean times of 4.5, 4.2, and 3.8 years with non-obese, obese, and morbidly obese, respectively (P = 0.023)).

CONCLUSIONS

The success of PJI management with two-stage arthroplasty is significantly impacted by patient BMI, with morbidly obese subjects having the worst outcomes. Attempts to modify BMI before completion of two-stage PJI treatment should be considered in the morbidly obese given high rates of recurrence.

Matching into shoulder and elbow surgery fellowships: do United States Medical License Exam scores and Alpha Omega Alpha status still matter?

BACKGROUND

Despite the established importance of the United States Medical License Exam (USMLE) and Alpha Omega Alpha (AOA) status in orthopedic residency selection, their significance in the fellowship match remains unknown. This study evaluates the influence of USMLE scores and AOA status on interview invitation rates and match positions for shoulder and elbow surgery fellowship applicants.

METHODS

This is a retrospective analysis of data from the San Francisco Match database from 2018 to 2023. The study included matched applicants for shoulder and elbow surgery fellowship, excluding unmatched applicants, osteopathic, and international medical graduates. USMLE scores were categorized into 4 tiers, and interview invitation rates were examined based on USMLE tier and AOA status. Additionally, the association between USMLE scores and AOA status were analyzed by applicant and fellowship rank positions. Statistical analysis included descriptive statistics, linear regression, and analysis of variance.

RESULTS

Data from 218 matched applicants were included. On average, applicants submitted 23.3 ± 9.7 applications, with an average interview rate of 76%. The mean step 1 and 2 score was 247 ± 11 (n = 141) and 253 ± 12 (n = 171), respectively. USMLE scores showed a positive correlation with interview rates (step 1: P < .0001, B = 0.768; step 2: P < .0001, B = 0.727), indicating that higher scores were associated with increased interview opportunities. AOA members accounted for 38% of applicants (of 183 with available data), and they demonstrated a higher average percentage of interviews compared to non-AOA applicants (79% vs. 75%, P < .001). While no significant difference in the average step 1 (P = .17) or step 2 score (P = .79) was observed across applicant rank positions, AOA membership was more prevalent among applicants in higher rank tiers (P < .001). Additionally, AOA applicants (P < .001) and those with higher step 2 scores (P = .04) were more likely to be ranked higher by their matched fellowship program.

CONCLUSION

USMLE scores and AOA status correlate with interview invitation rates and applicant ranking for shoulder and elbow surgery fellowships. Future work should examine the influence of residency reputation and research productivity on shoulder and elbow surgery fellowship match outcomes.

Intra-wound vancomycin powder is cost-saving in primary total hip and knee arthroplasty

PURPOSE

This study seeks to explore whether intra-wound vancomycin powder (IVP) is a cost-effective adjunct to standard of care (SOC) in patients undergoing total joint arthroplasty (TJA) from a US payor perspective.

METHODS

A decision-analytic model in the form of a decision tree was developed to compare the cost and outcomes of IVP with those of SOC in preventing periprosthetic joint infections (PJI) in TJA patients. The base case analysis assumes a hypothetical practice with an equal volume (50/50) of THA and TKA procedures in both the IVP + SOC and the SOC arm. Cost and clinical effectiveness data were obtained from published literature. Sensitivity and threshold analyses were used to estimate how changing inputs would impact the cost-effectiveness of IVP.

RESULTS

Deterministic results found that in the base case model, IVP as an adjunct to SOC generates a cost saving of $260.38/patient. In scenario analysis, where THA and TKA procedures were separated, the estimated cost saving was $241.50/patient and $279.27/patient, respectively. Break-even analysis showed that the cost of IVP per patient would need to be $244.82-$282.59, or the PJI relative risk (RR) be approximately 0.99. Probabilistic analysis found IVP + SOC was cost-saving in 99.26% of the 10,000 iterations in the base case model.

CONCLUSION

Applying local vancomycin as an adjunct to SOC in primary TJA is not just cost effective, but cost-saving in reducing PJIs, saving an average of $260.38/patient. Depending on individual institution/practice infection rates and revision surgery costs, local vancomycin administration for primary TJA should be considered.

Streptococcus canis Rapidly Progressive and Fatal Neonatal Sepsis in a Term Infant

BACKGROUND

Streptococcus canis ( S. canis ), belonging to β-hemolytic group G streptococci, is increasingly reported to cause sepsis and severe infections in adults with comorbidities but is rarely reported in children.

METHODS

We describe a case of S. canis neonatal sepsis in a term infant with a rapidly fatal outcome. We reviewed the literature on neonatal infections due to all group G streptococci including S. canis .

RESULTS

We identified 10 articles describing 19 cases of neonatal sepsis due to group G streptococcus, of which only 3 cases were identified at the species level. Most patients presented in the first week of life with neonatal sepsis with bacteremia present in 90% of cases. Among the patients, gestational age ranged from 31 to 42 weeks. Prematurity was reported in 35% of the patients. All patients were treated with β-lactams with or without aminoglycosides. Mortality was 26%.

CONCLUSIONS

S. canis infection is rare in the setting of neonatal sepsis; however, it can lead to high morbidity and mortality. It is imperative to promptly administer empiric antibiotics for critically ill neonates until neonatal sepsis is ruled out. β-lactams provide adequate coverage against S. canis . Further epidemiological and clinical studies focusing on S. canis are needed to fully understand the transmission and disease burden of this pathogen in neonates.

Multidimensional Analysis of Preoperative Patient-Reported Outcomes Identifies Distinct Phenotypes in Total Knee Arthroplasty: Secondary Analysis of the SHARKS Registry in a Public Hospital Department

Traditional research on total knee arthroplasty (TKA) relies on preoperative patient-reported outcome measures (PROMs) to predict postoperative satisfaction. We aim to identify distinct patient phenotypes among TKA candidates, and investigate their correlations with patient characteristics. Between 2017 and 2021, patients with primary knee cases at a metropolitan public hospital were enrolled in a clinical quality registry. Demographics, clinical data, and the Veterans Rand 12 and Oxford Knee Score were collected. Imputed data were utilized for the primary analysis, employing k-means clustering to identify four phenotypes. Analysis of variance assessed differences in scores between clusters, and nominal logistic regression determined relationships between phenotypes and patient age, sex, body mass index (BMI), and laterality. The sample comprised 389 patients with 450 primary knees. Phenotype 4 (mild symptoms with good mental health) exhibited superior physical function and overall health. In contrast, patients in phenotype 2 (severe symptoms with poor mental health) experienced the most knee pain and health issues. Phenotype 1 (moderate symptoms with good mental health) reported high mental health scores despite knee pain and physical impairment. Patient characteristics significantly correlated with phenotypes; those in the severe symptoms with poor mental health phenotype were more likely to be younger, female, have a higher BMI, and bilateral osteoarthritis (p < 0.05). This multidimensional analysis identified TKA patient phenotypes based on common PROMs, revealing associations with patient demographics. This approach has the potential to inform prognostic models, enhancing clinical decision-making and patient outcomes in joint replacement.

The assessment of implant shape-dependent failure mechanisms in primary total hip arthroplasty using finite element analysis

The three mechanisms known to be responsible for the failure of uncemented femoral stems in primary total hip arthroplasty (THA) are the stress shielding, excessive bone-implant interface stress, and excessive initial micromotion. Since implant designers usually have to sacrifice two mechanisms to improve the other one, the aim of this study was to assess which of them plays a more important role in the failure of uncemented stems. Two hip implant stems which are widely used in the primary THA and their mid-term clinical outcomes are available, were selected. Then, the amount of the three failure mechanisms created by each stem during the normal walking gait cycle was determined for a 70 kg female patient using the finite element method. The results indicated that the stem with better clinical outcome induced an average of 36.6% less stress shielding in the proximal regions of femur bone compared with the other stem. However, the maximum bone-implant interface stress and maximum initial micromotion were, respectively, 30 and 155% higher for the stem with better clinical outcomes. It was therefore concluded that the stress shielding has a more significant impact on the mid-term life of uncemented stems. However, care must be taken to ensure that the other two failure mechanisms do not exceed a certain threshold. It was also observed that the thinner and shorter stem created a smaller amount of stress shielding in the femur bone. The outcomes of this study can be used to design new hip implant stems that can potentially last longer.

A Higher Area Deprivation Index Is Associated With Increased Medical Complications and Emergency Department Utilizations After Total Hip Arthroplasty

BACKGROUND

The Area Deprivation Index (ADI) is a weighted index comprised of 17 census-based markers of material deprivation and poverty. The purpose of this study was to determine whether patients undergoing total hip arthroplasty (THA) in areas of high ADI (greater disadvantage) were associated with differences in 90 days: 1) medical complications; 2) emergency department (ED) utilizations; and 3) readmissions.

METHODS

A nationwide database was queried for primary THA patients from 2010 to 2020. The ADI is reported on a scale of 0 to 100, with higher numbers indicating greater disadvantage. Patients undergoing primary THA in regions associated with high ADI (90%+) were compared to those of lower ADI (0 to 89%). A total of 138,670 patients were evenly matched between the two cohorts following 1:1 propensity score matching by age, sex, and Elixhauser Comorbidity Index. Primary endpoints were 90-day medical complications, ED utilizations, and readmissions. Multivariable logistic regression models calculated the odds ratios (ORs) and 95% confidence intervals (CIs). P values less than 0.01 were statistically significant.

RESULTS

Patients undergoing THA from high ADI had significantly higher rates and odds of developing any medical complications (13.0 versus 11.9%; OR: 1.09, P < 0.0001), including acute kidney injuries (1.8 versus 1.5%; OR: 1.20, P < 0.0001), myocardial infarctions (0.35 versus 0.24%; OR: 1.45, P = 0.0003), and surgical site infections (0.94 versus 0.76%; OR: 1.23, P = 0.0004). High-ADI patients had significantly higher rates and odds of ED visits within 90 days (3.94 versus 3.67%; OR: 1.08, P = 0.008). There was no significant difference in readmissions (5.44 versus 5.69%; OR: 0.95, P = 0.034).

CONCLUSIONS

Socioeconomically disadvantaged patients have increased odds of 90-days medical complications and ED utilizations, despite comparable 90-day readmission rates. Measures of neighborhood disadvantage may be valuable metrics to inform health care policy and improve postdischarge care.

Patient-Level Factors, Outcomes, and Costs Associated With Facility Transfer Following Total Knee Arthroplasty: A Retrospective Database Study

BACKGROUND

Patient disposition following total knee arthroplasty (TKA) has major implications for patient outcomes and costs. Current studies are limited in sample size and dates of data collection. We evaluated patient factors, outcomes, and costs associated with disposition to a facility following TKA.

METHODS

This was a retrospective cohort study including 1,906,670 patients undergoing TKA from a nationwide database, from the years 2016 to 2020. Of these, 25,485 (1.34%) patients were transferred to a facility for rehabilitation. Demographic data, hospital-related outcomes, and postoperative complications were collected. Multivariate regression was performed to assess outcomes associated with facility transfer for rehabilitation.

RESULTS

Patients were more likely to be transferred if they were women (odds ratio (OR) = 1.10; P < 0.001), greater than 80 years (OR = 2.25; P < 0.001), had an increased Elixhauser comorbidity index (OR = 1.38; P < 0.001), or were in the lowest income quartile (OR = 1.38; P < 0.001). Transferred patients were more likely to experience medical (OR = 1.92; P < 0.001) and surgical complications (OR = 2.74; P < 0.001), including vascular complications (OR = 2.07; P < 0.001), neurologic complications (OR = 5.72; P < 0.001), and dislocation (OR = 2.01; P < 0.001). They also had greater hospital lengths of stay (OR = 5.27; P < 0.001) and hospital charges (OR = 1.88; P < 0.001); however, they were less likely to undergo reoperation within 30 days (OR = 0.61; P = 0.002).

CONCLUSIONS

Elderly, lower income patients who had more comorbidities are more likely to be transferred to a facility following TKA. While there are associated increased costs, complications, and hospital lengths of stay, there are lower rates of reoperation for those who transferred to a facility after TKA.

Several factors predict the achievement of the patient acceptable symptom state and minimal clinically important difference for patient-reported outcome measures following anterior cruciate ligament reconstruction: A systematic review

PURPOSE

To summarize the predictors of the patient acceptable symptom state (PASS), minimal clinically important difference (MCID) and minimal important change (MIC) for patient-reported outcome measures (PROMs) following anterior cruciate ligament reconstruction (ACLR).

METHODS

MEDLINE, PubMed and Embase were searched from inception to 5 January 2024. The authors adhered to PRISMA/R-AMSTAR guidelines, and the Cochrane Handbook for Systematic Reviews of Interventions. Data on statistical associations between predictive factors and PROMs were extracted. Inverse odds ratios (ORs) and confidence intervals (reverse group comparison) were calculated when appropriate to ensure comparative consistency.

RESULTS

Thirteen studies comprising 21,235 patients (48.1% female) were included (mean age 29.3 years). Eight studies comprising 3857 patients identified predictors of PASS, including lateral extra-articular tenodesis (LET) (OR = 11.08, p = 0.01), hamstring tendon (HT) autografts (OR range: 2.02-2.63, p ≤ 0.011), age over 30 (OR range: 1.37-2.28, p ≤ 0.02), male sex (OR range: 1.03-1.32, p ≤ 0.01) and higher pre-operative PROMs (OR range: 1.04-1.21). Eight studies comprising 18,069 patients identified negative predictors of MCID or MIC, including female sex (OR = 0.93, p = 0.034), absence of HT autografts (OR = 0.70, p < 0.0001), higher pre-operative PROMs (OR = 0.76-0.84, p ≤ 0.01), meniscectomy (OR = 0.67, p = 0.014) and collision sports (OR = 0.02-0.60, p ≤ 0.05).

CONCLUSION

Higher pre-operative PROMs, age over 30, male sex, LETs and HT autografts predicted PASS achievement. Lower pre-operative PROMs, male sex, non-collision sports, and lack of meniscectomies predicted MCID/MIC achievement. This review provides a comprehensive understanding of the predictors of clinically significant post-ACLR outcomes, thus improving clinical decision-making and the management of patient expectations.

LEVEL OF EVIDENCE

Level IV.

Use of Dual-Mobility Cups Reduce Dislocation Risk After Internal Fixation for Acetabular Fracture Concomitant With Total Hip Arthroplasty in Patients Who Are over 60 Years Old

BACKGROUND

Treatment of complex acetabular fractures in patients over 60 remains challenging. Functional treatments for these fractures have yielded disappointing outcomes. Internal fixation may fail facing this porotic bone, and postoperative non-weight-bearing may expose the patient to decubitus complications. Our hypothesis was that use of a dual-mobility cup (DMC) reduces dislocation risk after concomitant internal fixation and total hip arthroplasty (THA) for acetabular fracture in patients who are over 60 years old.

METHODS

A retrospective, observational noncomparative and continuous study was conducted from January 2015 to September 2022. Patients aged over 60 years who had displaced acetabular fractures, treated surgically via concomitant internal fixation and THA, using a DMC exclusively through the Kocher-Langenbeck approach and a minimum follow-up was of one year, were included. There were 45 patients (45 hips) who had an average age of 71 years (range, 60 to 88) who were included (75.5% men). The main mechanisms of injury were the motor vehicle accidents (in 21 cases (46.7%)). Bicolumn fractures were prevalent (46.6%). The analysis of complications included intraoperative nerve palsy, postoperative dislocations, deep infections, periprosthetic fractures, and loosening. Clinical assessment included the Harris hip score and the level of return to previous activities. Radiological evaluation assessed fracture union, periprosthetic osteolysis, graft integration, the presence of leg length discrepancy and heterotopic ossification.

RESULTS

There was one case of dislocation (2.2%) requiring reoperation for replacement of the prosthetic neck, and one patient (2.2%) experienced early THA infection, successfully treated with surgical lavage and antibiotics. Functional outcomes showed a mean Harris hip score of 88 (range, 69 to 99) and 84% of patients resumed their previous activities. Radiological follow-up revealed no loosening.

CONCLUSIONS

This study has shown that the use of DMC in concomitant THA with open reduction and internal fixation for acetabular facture in patient over age 60 years achieved a low dislocation rate with favorable clinical and radiological outcomes and a low complication rate.

Ropivacaine-epinephrine-clonidine-ketorolac is an effective opioid-sparing local anesthetic for patients undergoing posterior spinal fusion

BACKGROUND CONTEXT

Ropivacaine-Epinephrine-Clonidine-Ketorolac (RECK) cocktail can improve pain control in patients undergoing lumbar decompression. Given the aging population, rising healthcare costs, the opioid epidemic, and associations of acute pain control with long-term opioid use, effective opioid-sparing analgesia following spinal fusion surgery may impart societal benefits.

PURPOSE

We aimed to investigate whether RECK was an effective local anesthetic for patients undergoing posterior spinal fusion.

STUDY DESIGN/SETTING

Single-center retrospective cohort study.

PATIENT SAMPLE

Patients who underwent posterior spinal fusion surgery from June 2019 to June 2021.

OUTCOME MEASURES

Primary outcomes of interest were postoperative pain levels as determined by Visual Analog Scale, in-hospital opioid consumption, length-of-stay <4 days, and long-term opioid utilization at three months postoperatively. Secondary outcomes of interest were rates of discharge to home, complication rates, readmissions within 90 days.

METHODS

We analyzed whether opioid exposure, patient-specific or surgery-specific factors, and administration of RECK (versus another local anesthetic) were associated with postoperative pain levels, in-hospital opioid consumption, length-of-stay, home discharge, long-term opioid utilization, complications, and readmissions within 90 days using multivariable regression.

RESULTS

Of the 162 patients meeting study criteria, 49 (30.2%) received RECK. RECK was significantly associated with decreased pain levels at 2-, 4-, 6-, and 12-hours postoperatively (p≤.001-.01). RECK was associated with decreased total and daily inpatient opioid utilization (as measured by oral morphine equivalents) in multivariable linear regression (B=-159.6, 95% CI:-255.5- -63.6, p=.002 and B=-27.9, 95% CI:-48.9- -7.0, p=.01, respectively). Length-of-stay duration of <4 days was associated with RECK administration (OR 4.1, 95% CI:1.4-13.2, p=.01) and was negatively associated with levels fused (OR 0.4, 95% CI:0.2-0.7, p=.005) and durotomy (OR 0.02, 95% CI:0.0009-0.1, p<.001). Prolonged postoperative opioid utilization was associated with preoperative opioid prescription (OR 3.6, 95% CI:1.7-7.8, p=.001) and was negatively associated with RECK (OR 0.4, 95% CI:0.2-0.9, p=.04). RECK was not associated with readmissions, complications, or home discharge.

CONCLUSIONS

In patients undergoing posterior spinal fusion, RECK was superior to other local anesthetics as it improved pain control, decreased length-of-stay, and decreased opioid utilization. RECK was not associated with increased complications, readmissions, or rates of discharge to home.

Incidence of fall-from-height injuries and predictive factors for severity

CONTEXT

The injuries caused by falls-from-height (FFH) are a significant public health concern. FFH is one of the most common causes of polytrauma. The injuries persist to be significant adverse events and a challenge regarding injury severity assessment to identify patients at high risk upon admission. Understanding the incidence and the factors that predict injury severity can help in developing effective intervention strategies. Artificial intelligence (AI) predictive models are emerging to assist in clinical assessment with challenges.

OBJECTIVES

This retrospective study investigated the incidence of FFH injuries utilizing conventional statistics and a predictive AI model to understand the fall-related injury profile and predictive factors.

METHODS

A total of 124 patients who sustained injuries from FFHs were recruited for this retrospective study. These patients fell from a height of 15-30 feet and were admitted into a level II trauma center at the border of US-Mexica region. A chart review was performed to collect demographic information and other factors including Injury Severity Score (ISS), Glasgow Coma Scale (GCS), anatomic injury location, fall type (domestic falls vs. border wall falls), and comorbidities. Multiple variable statistical analyses were analyzed to determine the correlation between variables and injury severity. A machine learning (ML) method, the multilayer perceptron neuron network (MPNN), was utilized to determine the importance of predictive factors leading to in-hospital mortality. The chi-square test or Fisher's exact test and Spearman correlate analysis were utilized for statistical analysis for categorical variables. A p value smaller than 0.05 was considered to be statistically different.

RESULTS

Sixty-four (64/124, 51.6 %) patients sustained injuries from FFHs from a border wall or fence, whereas 60 (48.4 %) sustained injuries from FFHs at a domestic region including falls from roofs or scaffolds. Patients suffering from domestic falls had a higher ISS than border fence falls. The height of the falls was not significantly associated with injury severity, but rather the anatomic locations of injuries were associated with severity. Compared with border falls, domestic falls had more injuries to the head and chest and longer intensive care unit (ICU) stay. The MPNN showed that the factors leading to in-hospital mortality were chest injury followed by head injury and low GCS on admission.

CONCLUSIONS

Domestic vs. border FFHs yielded different injury patterns and injury severity. Patients of border falls sustained a lower ISS and more lower-extremity injuries, while domestic falls caused more head or chest injuries and low GCS on admission. MPNN analysis demonstrated that chest and head injuries with low GCS indicated a high risk of mortality from an FFH.

The use of an imageless robotic system in revision of unicompartmental knee arthroplasty

PURPOSE

The application of robotics in revision arthroplasty particularly from unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA), is underexplored. The purpose of this study is to describe the surgical technique of an imageless robotic system used in the revision of UKA to TKA and to evaluate short- to mid-term outcomes.

METHODS

This prospective study includes 35 patients treated from May 2020 to July 2023. Demographic data of the patients were gathered and the reasons for needing revision surgery were assessed. All patients were clinically evaluated preoperatively and at the final follow-up of 31.3 ± 12.1 months, using the Western Ontario and McMaster Universities Arthritis Index (WOMAC), Oxford Knee Score (OKS), Forgotten Joint Score (FJS-12), Numerical Rating Scale (NRS) and range of motion (ROM). Additionally, a radiographic evaluation was performed, and implant survival was assessed by analyzing complications at final follow-up.

RESULTS

In 88.6% of the patients, a primary Posterior Stabilized (PS) or Constrained Posterior Stabilized prosthetic implant was used, with 11.4% of patients requiring a varus-valgus constraint implant. In 71.4% of the cases, a thinnest size liner of 10 mm was used. The use of the robotic system was never aborted for any reason. At final follow-up, the implant survival rate was 97.14%. Average OKS increased from 31.4 ± 9.4 to 41.5 ± 4.3, FJS-12 from 47.3 ± 19.3 to 80.7 ± 8.9; WOMAC at final follow-up was 17.8 ± 8.7, from 53.5 ± 21.3 preoperatively. Analyzing ROM, NRS and patient-reported outcome measures, there were significant differences in each parameter between prerevision surgery and final follow-up.

CONCLUSIONS

This study highlights that in a cohort of patients undergoing robotic-assisted conversion from UKA to TKA, the use of an imageless procedure incorporating intraoperative bone morphing and alignment based on a functional philosophy has proven to be safe and has yielded excellent clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Hidden costs of first choice alternatives: A financial model of thromboprophylaxis and prosthetic joint infection prophylaxis in total knee arthroplasty

Background

Aspirin has been shown to be equally or more effective than factor Xa inhibitors for thromboprophylaxis following total knee arthroplasty (TKA). Cefazolin has been proven more effective than vancomycin in preventing prosthetic joint infection (PJI) after TKA. This study aimed to compare costs between different drug combinations for prevention of venous thromboembolism (VTE) and PJI following TKA, focusing on costs associated with PJI management.

Methods

We used published PJI rates for TKA patients treated with aspirin or factor Xa inhibitors for thromboprophylaxis, as well as for those who received prophylactic cefazolin or vancomycin. Unit prices for each drug and labor costs associated with vancomycin administration were obtained from our hospital's pharmacy service. The PJI cost model included the price of 2-stage septic TKA revision and national projections of future TKA volume.

Results

The least expensive average per-patient cost resulted from the combination of aspirin and cefazolin, equating to $521.19 given a 0.8 % PJI rate. The most expensive average per-patient cost was the combination of a factor Xa inhibitor and vancomycin, equaling $5,714.96 given a 1.8 % PJI rate. This extrapolates to an annual cost burden of $19.5 billion by 2040.

Conclusion

The average per-patient cost of using a combination of a factor Xa inhibitor and vancomycin is 711 % greater than the combination of aspirin and cefazolin. In this era of value-based care, aspirin and cefazolin should be considered gold standards for TKA thromboprophylaxis and PJI prophylaxis, as they reduce costs and improve patient outcomes.

Surgical Outcomes of Total Hip Arthroplasty With Paavilainen Osteotomy in Patients Who Have High Developmental Hip Dislocation: Mean 4.4-Year Follow-Up

BACKGROUND

Although subtrochanteric osteotomy is a common procedure, the use of Paavilainen osteotomy combined with total hip arthroplasty (THA) for high developmental hip dislocation is less documented. This study assessed the efficacy and complications of this approach, with a particular focus on the risk factors for nonunion postosteotomy.

METHODS

All patients who had high dislocated hip dysplasia who underwent combined THA and Paavilainen osteotomy were retrospectively reviewed with over 1 year of follow-up. A total of 44 patients (51 hips) were included, with an average follow-up period of 4.4 years (range, 1.97 to 6.94). Anatomical data of the hip joints were measured on preoperative and postoperative radiographs. Demographic data, Trendelenburg sign, complications related to this procedure, Harris Hip Score, and EuroQoL-5-Dimension 5-Level health questionnaire were collected from the medical chart. Binary logistic regression analysis was used to identify predictors for bone nonunion.

RESULTS

Out of the 51 hips, eight displayed a positive Trendelenburg sign. Patients' Harris Hip Score saw an improvement from 43.8 ± 11.8 preoperatively to 85.7 ± 11.1 at the latest follow-up (P < 0.001), accompanied by a substantial enhancement in the average EuroQoL-5-Dimension 5-Level score from 0.38 ± 0.15 to 0.87 ± 0.13 (P < 0.001). Non-union, as the most concerning complication, occurred in 12% (seven of 56) of osteotomy cases. The contact length between the osteotomy block and femoral cortex was a key risk factor for nonunion. The receiver operating characteristic analysis identified 2.15 cm as the critical bone contact length for healing.

CONCLUSIONS

Paavilainen osteotomy combined with THA and subtrochanteric osteotomy proved effective and less complex than other techniques for high-dislocation hip dysplasia. A bone contact length between the greater trochanteric fragment and the femoral cortex of less than 2.15 cm is a risk factor for nonunion.

"Intra-operative assessment of leg length discrepancy with anterior approach total hip replacement: a comparison between standard table, position table with and without intra-operative radiographs"

PURPOSE

Post-operative LLD is a major concern after THA. The anterior approach on a standard table allows surgeons for a direct control of the leg length. Intra-operative radiography (IR) helps in assessment of hip biomechanics and anatomic parameters. The aim of this study is to evaluate the LLD after THA through anterior approach with or without a position table and with or without the use of intra-operative radiographs. The hypothesis is that leg length may be better control when IR and a standard table are used.

METHODS

This is a single-centre retrospective comparative cohort study of three matched groups of 80 patients receiving anterior approach THA with three different techniques (Group A: positioning table with IR; Group B: standard table with IR; Group C: standard table without IR). Pre-operative and post-operative LLD was calculated. Age, sex, BMI, acetabular cup and femoral stem size, operative time, and blood loss were recorded.

RESULTS

In Group A, 15 patients (19%) had a LLD greater than 5 mm, and two patients (2,5%) had a LLD greater than 10 mm. In Group B, 20 patients (25%) had a LLD greater than 5 mm, and two patients (2,5%) had a LLD greater than 10 mm. In Group C, 16 patients (20%) had a LLD greater than 5 mm, and three patients (3,7%) had a LLD greater than 10 mm. No statistically significant differences were found for LLD > 5 mm, for LLD > 10 mm, nor for the mean LLD between the three groups (p  > 0.05). Mean operative time was statistically longer in Group B (p  < 0.05).

CONCLUSION

Neither the use of a standard/positioning table neither the use of IR seemed to be superior in restoring leg length after anterior approach THA. Together with the contradictory results in literature, findings of the current study indicate that no technique is clearly superior to one other and surgeons' experience may play the most relevant role.

Wound complication rates after anterior total hip arthroplasty: A case series comparison of interrupted vs. continuous sutures for skin closure

Background

The anterior approach for total hip arthroplasty (THA) carries a higher risk of wound complications, which can significantly affect patient outcomes and increase healthcare costs. There is limited research comparing infection rates based on closure techniques in patients who undergo THA. Therefore, this study aims to compare wound complications based on interrupted or continuous sutures for skin closure after anterior approach THA.

Methods

This single-surgeon retrospective study extracted data from 388 patients who had undergone a primary THA using the anterior approach. Patient demographics, comorbidities, perioperative factors, and infection-related complications were recorded. All variables associated with a given infection complication were controlled for in a binary logistic regression model.

Results

After controlling for confounding variables, wound closure type was not associated with any infectious complications. BMI was a strongly associated factor in PJI (p = 0.028; 95 % CI = 1.02-1.34), prolonged drainage (p < 0.001; 95 % CI = 1.08-1.28), readmission (p = 0.023; 95 % CI = 1.01-1.20), and I&D and revision surgery (p = 0.021; 95 % CI = 1.02-1.31).

Conclusion

Body mass index was the sole factor associated with a higher risk of wound complications postoperatively. These findings suggest a non-inferiority between continuous and interrupted suture closure techniques regarding wound-related infectious complications in anterior total hip arthroplasty.

Risk assessment model used to predict discharge care after total hip and total knee arthroplasty: A population-based study

Background

Transfer to a post-acute care facility or hospital readmission after total joint arthroplasty represent additional costs and increased surgical and health care resource utilization. Accurate prediction of post-acute care factors could help providers to plan the patient's discharge destination and have a positive impact on postoperative outcomes and readmission rates.

Objective

To develop a risk assessment model to predict discharge care after total hip arthroplasty (THA) and total knee arthroplasty (TKA).

Design

A retrospective longitudinal observational study.

Settings

and participants: This study included 209 patients who underwent primary unilateral THA or TKA at a major academic medical center in Switzerland from January 2018 to December 2019.

Methods

A collection of computerized- and paper-recorded data identified the discharge destination, socio-demographic factors, comorbidities, and other factors related to the patient. Univariate and multivariate analyses were performed to describe the predictors of post-surgical discharge destinations.

Results

The characteristics associated with post-acute care after primary unilateral THA or TKA were the absence of a caregiver, advanced age, female gender, presence of walking aids, high ASA score, and comorbidity severity. A prediction model demonstrated that these six characteristics were associated 52 % with discharge to a post-acute care destination.

Conclusions

This study allowed us to identify predictors of discharge to a post-surgical destination. Predictive models can be efficiently used to better predict which patients are predisposed to post-acute care after hospital discharge. Further studies are needed to determine the optimal criteria for different destinations.

Total knee arthroplasty reimbursement is declining overall and at a marginally faster rate amongst female orthopaedic surgeons: A Medicare analysis

Background

While the prevalence of total knee arthroplasty (TKA) is increasing, reimbursement is declining. The purpose of this study was to determine how surgeon gender influences procedure volume, reimbursement, practice style, and patient demographics for TKAs nationally and regionally between 2013 and 2021.

Methods

The Medicare Physician and Other Practitioners database was queried from 2013 to 2021 for procedure volume, TKA reimbursement, surgeon characteristics, and patient demographics for any surgeon who performed at least ten primary TKAs per year. Statistical tests were conducted to analyze differences based on surgeon gender, geography, and year.

Results

Of the 2,415,802 TKAs performed between 2013 and 2021, 1.5 % were billed by female surgeons. The number of TKAs performed annually increased by 29.1 % for female surgeons and decreased by 2.6 % for male surgeons. Between 2013 and 2021, reimbursement for TKAs decreased by 23.9 % for male surgeons and 26.2 % for female surgeons. In 2021, male surgeons were reimbursed $1017 per TKA while female surgeons were reimbursed $964 (p = 0.049). Male surgeons performed more TKAs annually in 2021 (Male: 39.3, Female: 30.9, p < 0.001), more total billable services (Male: 4148.0, Female: 2719.3, p < 0.001), and more unique billable services (Male: 70.7, Female: 55.3, p < 0.001) than female surgeons.

Conclusions

Female representation among surgeons who perform TKAs is increasing nationally. However, male surgeons treat more patients, perform more total billable services, and perform more unique billable services than female surgeons. TKA reimbursement is decreasing at a faster rate for female surgeons than male surgeons, although this is likely due to geographical differences.

Patients Have Acceptable Patient-Reported Outcome Measures After Medial Unicompartmental Knee Arthroplasty Regardless of Age

BACKGROUND

Contemporary evidence-based indications no longer consider age regarding eligibility for medial unicompartmental knee arthroplasty (mUKA). This has led to more surgical candidates; however, whether patients still have satisfactory outcomes lacks evidence. This study examined the association between age and change in patient-reported outcome measures after mUKA as well as the achievement of patient acceptable symptom state (PASS) and minimal important change (MIC).

METHODS

We included 782 mUKAs performed between February 1, 2016, and April 26, 2023. The mean change from preoperative Oxford knee score (OKS), forgotten joint score (FJS), and activity and participation questionnaire (APQ) was assessed at 3, 12, and 24 months after surgery, respectively. The achievement of 12-month PASS (OKS ≥ 30) and MIC (changes in OKS ≥ 8; FJS ≥ 14) was also assessed. Patients were divided into the following age groups: <55, 55 to < 65, 65 to < 75 years (reference group), and ≥ 75 years. There were 432 women (55%), and patients had a mean age of 67 years (range, 29 to 93) and a mean body mass index of 30 (range, 20 to 53).

RESULTS

Median OKS, youngest to eldest, were 34, 35, 36, and 35 (3 months); 40, 39, 41, and 43 (12 months); 42, 41, 43, and 42 (24 months), respectively. We found no differences in change in OKS between groups. Patients aged 55 to < 65 years had lower changes in FJS at 24 months and APQ at 12 and 24 months. Patients ≥ 75 years had lower 24-month changes in APQ. We found no association between age and the fraction achieving either PASS or MIC (youngest to eldest, 90, 90, 94, and 95%).

CONCLUSIONS

We found good patient-reported outcome measures improvements and satisfactory outcomes after mUKA in all age groups; however, patients aged 55 to < 65 years had worse changes in FJS and APQ. Results support contemporary indications for mUKA, and applying an age cutoff is unwarranted.

Electrodiagnostic Assessment of Peri-Procedural Iatrogenic Peripheral Nerve Injuries and Rehabilitation

Iatrogenic nerve injuries are a significant concern for medical professionals and the patients affected. Peri-procedural nerve injuries result in functional deficits associated with pain and disability. The exact pathophysiology and etiology of peri-procedural nerve injuries are complex and often elude providers. The rates of injury to specific nerves are unclear and relate to both procedural and patient specific risk factors. Initial classification of the nerve injury into neurapraxia, axonotmesis, mixed nerve injury, or possible complete transection (neurotmesis) guides rehabilitation and management. Electrodiagnostic medical consultation at least four weeks post-injury, supplemented with nerve imaging (ultrasound and magnetic resonance imaging), can allow for accurate nerve injury classification. Supplemented with nerve imaging and detailed clinical evaluation, treatment, recovery and rehabilitation can be maximized. Recognizing nerves at risk associated with medical and surgical procedures can facilitate injury avoidance and early diagnosis. If a nerve injury is incomplete, in an optimized physiologic milieu (good glucose control, smoking cessation, etc.), there is a good potential for spontaneous (total or partial) improvement over time. Surgical referral should be considered for severe nerve injuries within 6 months, especially if there is concern for neurotmesis, and/or deteriorating nerve function. This review gives guidance for approaching peri-procedural peripheral nerve injuries, including the timing and the role of electrodiagnostic medical consultation including serial electrodiagnostic studies in management and rehabilitation.