Survivorship and Clinical Outcomes of Primary Total Knee Arthroplasty Performed in Patients 35 Years of Age and Younger.

BACKGROUND: Total knee arthroplasties (TKAs) for patients aged ≤35 years are rare but necessary for patients who have diseases such as juvenile idiopathic arthritis, osteonecrosis, osteoarthritis, and rheumatoid arthritis. Few studies have examined the 10-year and 20-year survivorship and clinical outcomes of TKAs for young patients. METHODS: A retrospective registry review identified 185 TKAs in 119 patients aged ≤ 35 years performed between 1985 and 2010 at a single institution. The primary outcome was implant survivorship free of revision. Patient-reported outcomes were assessed at 2 time points: 2011 to 2012 and 2018 to 2019. The average age was 26 years (range, 12 to 35). Mean follow-up was 17 years (range, 8 to 33). RESULTS: Survivorship decreased from 84% (95% confidence interval [CI]: 79 to 90) at 5 years to 70% (95% CI: 64 to 77) at 10 years and to 37% (95% CI: 29 to 45) at 20 years. The most common reasons for revision were aseptic loosening (6%) and infection (4%). Risk factors for revision included increasing age at time of surgery (Hazards Ratio [HR] 1.3, P = .01) and use of constrained (HR 1.7, P = .05) or hinged prostheses (HR 4.3, P = .02). There were 86% of patients reporting that their surgery resulted in "a great improvement" or better. CONCLUSION: Survivorship of TKAs in young patients is less favorable than expected. However, for the patients who responded to our surveys, TKA demonstrated substantial pain relief and improvement in function at 17-year follow-up. Revision risk increased with older age and higher levels of constraint.

Novel Arthrometer for Quantifying In Vivo Knee Laxity in Three Planes Following Total Knee Arthroplasty.

BACKGROUND: Knee instability is a leading cause of dissatisfaction following total knee arthroplasty (TKA). Instability can involve abnormal laxity in multiple directions including varus-valgus (VV) angulation, anterior-posterior (AP) translation, and internal-external rotation (IER). No existing arthrometer objectively quantifies knee laxity in all three of these directions. The study objectives were to verify the safety and assess reliability of a novel multiplanar arthrometer. METHODS: The arthrometer utilized a five degree-of-freedom instrumented linkage. Two examiners each conducted two tests on the leg that had received a TKA of 20 patients (mean age 65 years (range, 53-75); 9 men, 11 women), with nine and eleven distinct patients tested at 3-month and 1-year postoperative time points, respectively. AP forces from -10 to 30 Newtons, VV moments of ±3 Newton-meters, and IER moments of ±2.5 Newton-meters were applied to each subject's replaced knee. Severity and location of knee pain during testing were assessed using a visual analog scale. Intraexaminer and interexaminer reliabilities were characterized using intraclass correlation coefficients. RESULTS: All subjects successfully completed testing. Pain during testing averaged 0.7 (out of possible 10; range, 0-2.5). Intraexaminer reliability was >0.77 for all loading directions and examiners. Interexaminer reliability and 95% confidence intervals were 0.85 (0.66-0.94), 0.67 (0.35-0.85), and 0.54 (0.16-0.79) in the VV, IER, and AP directions, respectively. CONCLUSION: The novel arthrometer was safe for evaluating AP, VV, and IER laxities in subjects who had received TKA. This device could be used to examine relationships between laxity and patient perceptions of knee instability.

Is there a difference in mobility and inpatient physical therapy need after primary total hip and knee arthroplasty? A decade-by-decade analysis from 60 to 99 years.

INTRODUCTION: Extended inpatient rehabilitation (PT) after total hip (THA) and knee arthroplasty (TKA) has a significant impact on total care costs. As patients age, extended PT might be required following THA and TKA. This study examined the relationship between patient age, functional mobility, inpatient PT need, and discharge disposition in THA and TKA patients. MATERIALS AND METHODS: This retrospective study included patients aged 60 + undergoing primary THA or TKA between 2018 and 2020 at an orthopedic hospital. Comparing by age-decade, 7374 (3600 THA, 3774 TKA) sexagenarians, 5350 (2367 THA, 2983 TKA) septuagenarians, 1356 (652 THA, 704 TKA) octogenarians, and 78 (52 THA, 26 TKA) nonagenarians were analyzed. We compared the number of PT sessions needed for discharge clearance and the postoperative functional mobility using the Activity Measure for Post-Acute Care (AM-PAC) tool. Statistical analyses included ANOVA with post-hoc Tukey's HSD for continuous data and Chi-squared test for categorical variables. RESULTS: The number of PT sessions required for discharge clearance increased with age after THA (3.3 ± 1.9 sessions vs 3.8 ± 2.1 vs 5.0 ± 2.7 vs 6.2 ± 3.0; p < 0.01) and TKA (4.0 ± 2.1 vs 4.7 ± 3.1 vs 5.2 ± 2.8 vs 5.0 ± 1.6; p < 0.01). The functional mobility improvement as measured by AM-PAC was significantly lower for nonagenarians after THA (4.9 ± 2.8 vs 5.1 ± 2.8 vs 4.6 ± 3.3 vs 3.3 ± 3.9; p < 0.01) and TKA (5.0 ± 2.9 vs 4.7 ± 3.2 vs 3.9 ± 3.4 vs 3.2 ± 2.6; p < 0.01). CONCLUSION: Patients in their eighth and ninth decade had less improvement in functional mobility during in-hospital rehabilitation and utilized more PT services. However, clinical results in the elderly are still satisfying and the data may be helpful for resource utilization planning and risk-adjustment in value-based payment models.

Blood management in direct anterior versus posterior primary total hip arthroplasty using tranexamic acid: a matched cohort study.

INTRODUCTION: Proponents of the direct anterior approach (DAA) for THA claim patients recover faster compared to primary THA through the posterior approach (PA). Blood loss and transfusion have substantially declined with the use of tranexamic acid (TXA). However, it is still controversial if hemoglobin drops and transfusion rates are affected by the surgical approach when TXA is routinely used. MATERIALS AND METHODS: 2418 patients undergoing DAA THA were matched 1:1 with patients undergoing PA THA according to preoperative hemoglobin (± 1 g/dl), age (± 5 years), sex, BMI (± 5 kg/m2) and year of surgery (± 2 years). All patients received perioperative TXA. None of the patients donated autologous blood. Hemoglobin levels, drain placement and output, blood transfusion rates and volume as well as length of stay were recorded. RESULTS: A closed suction drain was used in 121 (5.0%) DAA and in 135 (5.6%) PA THAs (p = 0.369). Mean drain output was higher in the DAA compared to the PA group (134 ml (0-520 ml) versus 92.3 ml (0-600 ml), p = 0.004). There was no difference in hemoglobin drop [2.6 g/dl versus 2.6 g/dl (p = 0.143)] and transfusion rate [n = 31 (1.3%) versus n = 29 (1.2%), p = 0.793)] between DAA and PA THA. Mean transfusion amounts were 421.8 ml (250-1120.8 ml) in the DAA and 353.9 ml (250-560 ml) in the PA group (p = 0.801). The length of stay was shorter in the DAA group with a mean 1.6 days versus 2.1 days in the PA group (p ≤ 0.001). CONCLUSION: In this large matched cohort study, there was no difference in the perioperative hemoglobin drop, the transfusion rate and the transfusion amount between DAA and PA THA.

Blood Management Following Total Joint Arthroplasty in an Aging Population: Can We Do Better?

BACKGROUND: To evaluate the transfusion rates for octogenarians and nonagenarians following total knee and hip arthroplasty (TKA, THA), we compared transfusion rates and associated risk factors among sexagenarians, septuagenarians, octogenarians, and nonagenarians. METHODS: This retrospective cohort study included 13,603 sexagenarians, 9796 septuagenarians, 2706 octogenarians, and 158 nonagenarians that received a primary, unilateral THA or TKA between 2016 and 2020 at a high-volume institution. Using multivariable logistic regression analysis, the study analyzed risk factors for postoperative transfusions including use of tranexamic acid (TXA) and compared preoperative and postoperative hemoglobin (Hgb) levels and the drop in Hgb. RESULTS: Nonagenarians had significantly higher transfusion rates (THA 25.5%, TKA 26.7%) than octogenarians (THA 9.9%, TKA 9.2%), septuagenarians (THA 3.3%, TKA 4.5%), and sexagenarians (THA 1.9%, TKA 2.9%) (P < .01). Significant risk factors for transfusion requirement following THA were American Society of Anesthesiologists level III (odds ratio [OR] 5.3, P < .01) and American Society of Anesthesiologists level IV (OR 8.0, P = .01), nonuse of TXA (intravenous: OR 0.3, P < .01; topical: OR 0.5, P < .01), lower preoperative Hgb levels (OR 0.4, P < .01), longer duration of surgery (OR 1.0, P < .01), and hepatopathy (OR 3.1, P < .01). Significant risk factors following TKA were nonuse of TXA (intravenous: OR 0.3, P < .01; topical: OR 0.5, P < .01; combined: OR 0.2, P < .01), lower preoperative Hgb levels (OR 0.4, P < .01), and longer surgery time (OR 1.0, P < .01). CONCLUSION: The strongest independent risk factors for increased transfusion rates among octogenarians and nonagenarians were lack of TXA application and lower preoperative Hgb levels. Routine TXA application and preoperative patient optimization are recommended to reduce transfusion rates in patients aged 80+.

Predicting Post-Discharge Opioid Consumption After Total Hip and Knee Arthroplasty in the Opioid-Naïve Patient.

BACKGROUND: Pain catastrophizing, anxiety, and depression are associated with poor outcomes after total hip (THA) and total knee (TKA) arthroplasty. The goal of this study is to determine the relationship between post-operative pain scores and opioid consumption; and the association among pre-operative measures of anxiety, depression, and pain catastrophizing and post-operative opioid consumption in patients undergoing THA and TKA. METHODS: This is a single-institution prospective cohort study of 243 opioid-naïve patients undergoing elective, primary THA (n = 123) or TKA (n = 120) for osteoarthritis. Pre-operatively, patients completed the PROMIS-29 (Patient-Reported Outcomes Measures Information System; physical function/anxiety/depression/fatigue/sleep disturbance/social activities/pain interference/pain intensity) and Pain Catastrophizing Scale. Post-operatively, patients completed a weekly survey for 12 weeks determining morphine-milligram-equivalent (MME) opioid consumption, opioid cessation, and visual analog scale pain scores. Multivariable regression models determined the association between pre-operative scores and post-operative opioid consumption. RESULTS: Mean (±standard deviation) total opioid consumption and duration was 75.1 ± 112.0 MME and 1.7 ± 1.7 weeks in THA and 384.7 ± 473.3 MME and 4.3 ± 3.5 weeks in TKA. Visual analog scale pain scores (0-100) after opioid cessation were 28.0 ± 22.9 in THA and 30.7 ± 25.8 in TKA. Multivariable regression showed that each unit increase in PROMIS-29 fatigue T-score was associated with 8.4 hours longer opioid usage in THA (P = .008) and 15.1 hours longer in TKA (P = .036), as well as 12.7 MME additional opioids in TKA (P = .027). There were no significant associations with other PROMIS-29 domains or the Pain Catastrophizing Scale. CONCLUSION: Opioid use duration is different for THA and TKA and may correlate with pain scores. Only pre-operative fatigue was associated with post-operative opioid consumption. These findings should inform THA and TKA post-operative pain management pathways.

Intraoperative Complications and Early Return to the Operating Room in Total Hip Arthroplasty Performed Through the Direct Anterior and Posterior Approaches. An Institutional Experience of Surgeons After Their Learning Curve.

BACKGROUND: Proponents of the direct anterior approach (DAA) for total hip arthroplasty (THA) claim a faster recovery, whereas critics claim an increased risk of early femoral complications. This study analyzed intraoperative and postoperative complications requiring reoperation within one year after THA through the DAA and posterior approach (PA). METHODS: A total of 2348 elective, unilateral DAA THAs in patients with osteoarthritis performed between 2016 and 2019 were matched 1:1 for age (±5 years), gender, body mass index (±5), and femoral fixation with 2348 patients who underwent PA THA during the same period. Mixed-effects logistic regression was used. Odds ratios were reported for the occurrence of intraoperative femoral fracture, postoperative femoral fracture, infection, dislocation, and other etiologies requiring reoperation within one year. RESULTS: Intraoperative femoral fracture occurred in 12 DAA (0.5%) and 14 PA (0.6%) patients. Twenty-five patients (1.06%) in the DAA and 28 (1.19%) in the PA group underwent reoperation within the first year. Reoperations were due to periprosthetic fracture (40%), infection (28%), dislocation (23%), and other (9%). Regression analysis revealed no difference in intraoperative femoral fracture (odds ratio (OR): 0.86, 95% confidence interval (CI): 0.40-1.86, P = .69), postoperative femoral fracture (OR: 1.10, 95% CI: 0.47-2.60, P = .83), infection (OR: 1.50, 95% CI: 0.53-5.23, P = .44), or reoperation within one year for other reasons (OR: 1.50, 95% CI: 0.25-9.00, P = .65). DAA had fewer dislocations requiring reoperation (OR: 0.20, 95% CI: 0.04-0.91, P = .02). CONCLUSION: This comparative study did not find differences in intraoperative or postoperative fracture or infection between DAA and PA. DAA was associated with a lower likelihood of reoperation for dislocation within one year of surgery.

Early Recovery Outcomes in Patients Undergoing Total Hip Arthroplasty Through a Posterior Approach With Modified Postoperative Precautions.

BACKGROUND: Recent data suggest that a modified, more lenient set of precautions after total hip arthroplasty (THA) performed through the posterolateral approach may safely allow more patient movement and exercise in the immediate postoperative period. We hypothesize that 1) patients undergoing THA given modified precautions will demonstrate a fast-track return to functional activity and 2) wrist-based activity trackers will provide valuable information on postoperative activity levels. METHODS: We prospectively enrolled patients undergoing THA. Patients were given a wrist-based, commercially available activity tracker to wear 1 week preoperatively and 6 weeks postoperatively. Postoperative hip precautions included only the avoidance of the "leg-shaving" position of combined hip flexion, adduction, and internal rotation. Linear mixed models were used to analyze the change in steps and Hip Disability and Osteoarthritis Outcome Score-Junior (HOOS)-JR data. Pearson correlation coefficients were used to describe the relationship between average steps and HOOS-JR scores over time. RESULTS: Eighty-two patients were enrolled. Seventy-four percent returned to work by week 4. Seventy-six percent of left THA patients returned to driving by week 4. At 6 weeks, 23% of survey respondents were taking pain medication and 26% were using assistive devices. Average daily steps were 1098 at week 1, 2491 at week 2, 4130 at week 3, 4850 at week 4, 5712 at week 5, and 6069 at week 6. A significant correlation (R: -0.981) was found between increased weekly steps and improved HOOS-JR scores after THA (P < .001). CONCLUSION: Defining expected recovery timelines for patients undergoing THA helps surgeons counsel their patients preoperatively. Our study demonstrates an expected pathway for recovery after THA by using modified precautions that will be more clearly outlined with ongoing clinical data analysis.

Small soft tissue tension changes do not affect patient-reported outcomes one year after primary TKA.

BACKGROUND: Adequate soft tissue tension and balance is paramount to achieve favourable outcomes of total knee arthroplasty (TKA). Implant manufacturers offer 1-mm liner increments to fine-tune ligament tension and balance. In this study, we assessed if soft tissue tension changes introduced by minimal changes in liner thicknesses affect early patient reported outcomes. METHODS: Eighty-nine patients undergoing 99 primary, elective TKAs by a single surgeon were included. After achieving adequate ligament balance, the first 50 knees received an insert that would allow 2-3 mm of medial and lateral opening (control group), whereas the last 49 received an insert which was 1 mm thicker, resulting in a slight increase in ligament tension (study group). Sensor technology was used to record compartmental loads. Knee Society Score (KSS), KOOS Jr., and ROM were recorded pre-operatively, six weeks, four and 12 months post-operatively. The Forgotten Joint Score (FJS) was administered four and 12 months post-operatively. RESULTS: No differences were observed in demographic variables, pre-operative outcome scores, and ROM measures between groups. Six weeks post-operatively, there was no statistically significant difference in the outcome variables. Four months post-operatively, statistically significant differences were only observed in KOOS Jr. (79 and 73.6; p = 0.05), and FJS (59.9 and 45.5; p < 0.01); all of which favoured the control group. There was no difference in the outcome variables at 12 months. CONCLUSION: Minor changes in soft tissue tension induced by 1-mm changes in liner thickness resulted in clinically meaningful differences favouring the control group four months post-operatively, but in no clinically noticeable differences 12 months post-operatively. It is possible that lower soft tissue tension may lead to transient improvement in patient-reported early outcomes.

How Well Represented Are Women Orthopaedic Surgeons and Residents on Major Orthopaedic Editorial Boards and Publications?

BACKGROUND: Recent studies indicate that women are substantially underrepresented as orthopaedic surgeons and residents compared with other specialties in medicine and medical school. The reasons for this are multifactorial and not completely understood, but previous studies suggest that women may be attracted to fields in which they have female role models. Given that women interested in academia and research may use female editorship and authorship as a proxy for female representation in orthopaedic surgery, we wanted to examine the proportion of women represented in orthopaedic journals and determine if it reflects the distribution of women in orthopaedic surgery as a field. We further wanted to understand if this representation has changed over time in the setting of a slowly shifting gender landscape within orthopaedic surgery. QUESTIONS/PURPOSES: (1) How are women orthopaedic surgeons and residents represented in orthopaedic journals compared with men? (2) Have these proportions changed in the past two decades in light of relatively new efforts to recruit women to the field of orthopaedic surgery? METHODS: The gender composition of editorial boards and first and last authors were obtained from the 1997, 2007, and 2017 volumes of the following journals: The Journal of Bone & Joint Surgery (JBJS), the Journal of the American Academy of Orthopaedic Surgeons (JAAOS), and Clinical Orthopaedics and Related Research® (CORR®). Gender neutral names were searched to obtain a picture to ensure proper tallies. RESULTS: The total combined amount of women first and last authors increased from 88 of 1450 (6%) in 1997 to 152 of 1912 (8%) in 2007 to 723 of 5391 (13%) in 2017. Similarly, three of 113 (3%) editorial board members were women in 1997, three of 105 (3%) were women in 2007 and 10 of 107 (9%) editors were women in 2017. Of note, 0 out of 9 editors-in-chief were women. CONCLUSIONS: Based on the current percentage of women orthopaedic surgeons and residents, women are represented equally or in greater numbers as editors and authors in JAAOS, JBJS, and CORR. This may be in part due to women orthopaedic surgeons entering academic medicine at a greater rate than males. CLINICAL RELEVANCE: Orthopaedic surgeons serving as mentors to prospective female applicants can cite female representation on editorial boards and as authors as an example of gender parity in the field. Additionally, active orthopaedic surgeons who are women interested in these leadership positions should be encouraged that these opportunities exist, regardless of gender.

Assessment of a Satisfaction Measure for Use After Primary Total Joint Arthroplasty.

BACKGROUND: Patient satisfaction after total hip (THA) and total knee arthroplasty (TKA) is a core outcome selected by the Outcomes Measurement in Rheumatology. Up to 20% of THA/TKA patients are dissatisfied. Improving patient satisfaction is hindered by the lack of a validated measurement tool that can accurately measure change. METHODS: The psychometric properties of a proposed satisfaction instrument, consisting of 4 questions rated on a Likert scale, scored 1-100, were tested for validity, reliability, and sensitivity to change using data collected between 2007 and 2011 in an arthroplasty registry. RESULTS: We demonstrated construct validity by confirming our hypothesis; satisfaction correlated with similar constructs. Satisfaction correlated moderately with pain relief (TKA ρ = 0.61, THA ρ = 0.47) and function (TKA ρ = 0.65, THA ρ = 0.51) at 2 years; there was no correlation with baseline/preoperative pain/function values, as expected. Overall Cronbach's alpha >0.88 confirmed internal consistency. Test-retest reliability with weighted kappa ranged 0.60-0.75 for TKA and 0.36-0.56 for THA. Hip disability and Osteoarthritis Outcome Score/Knee injury and Osteoarthritis Outcome Scores quality of life improvement (>30 points) corresponds to a mean satisfaction score of 93.2 (standard deviation, 11.5) after THA and 90.4 (standard deviation, 13.8) after TKA, and increasing relief of pain and functional improvement increased the strength of their association with satisfaction. The satisfaction measure has no copyright and is available free of cost and represents minimal responder burden. CONCLUSION: Patient satisfaction with THA/TKA can be measured with a validated 4-item questionnaire. This satisfaction measure can be included in a total joint arthroplasty core measurement set for total joint arthroplasty trials.

Causes of Revision in Young Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: The purpose of this study was to identify reasons for revision of total hip arthroplasty (THA) in patients who underwent primary THA at or before the age of 35 years. We hypothesized that the reasons for revision in younger patients would be different from the general older population of patients undergoing THA because of the differences in diagnoses, complexity of deformities, and differences in activity level. METHODS: Data for 108 hips in 82 patients who underwent primary THA at our institution before the age of 35 years from 1982-2007 and subsequently underwent revision THA were reviewed. Operative reports and clinic notes were reviewed to determine baseline characteristics, reason for revision, timing of revision, and components revised. RESULTS: The mean age at index surgery was 25.4 years, and mean time from index to revision surgery was 10.1 years. The most common preoperative diagnoses included avascular necrosis, juvenile idiopathic arthritis, developmental dysplasia of the hip, and posttraumatic arthritis. The most common reasons for revision were acetabular loosening (30.1%), femoral loosening (23.7%), and polyethylene wear (24.7%). 8.3% of patients underwent primary THA with highly cross-linked polyethylene, while the remainder of the patients underwent THA when conventional polyethylene was used. There was no statistically significant association between which component(s) were revised and initial fixation (ie cemented or uncemented prosthesis) (P = .26). CONCLUSION: Causes of revision in this population appear to differ from the general THA population. In young patients, acetabular loosening, femur loosening, and polyethylene wear were the most common causes of revision. Instability and infection were less common compared with literature reports of causes of revision in older patients. Findings in this study may be useful in counseling young patients undergoing THA, though results were likely influenced by the use of conventional rather than highly cross-linked polyethylene in this cohort.

The Opioid Epidemic in the United States: Where Do Patients Requiring Elective Arthroplasty Stand?

INTRODUCTION: Over the past decade, awareness about opioid abuse in the general community and among prescribers has increased. This study evaluated how opioid prescribing patterns before and after total hip arthroplasty (THA) and total knee arthroplasty (TKA) may have changed during a recent 5-year period. METHODS: The Truven Health MarketScan database were queried for patients who underwent elective THA and TKA for primary osteoarthritis between 2013 and 2017. The trend analysis evaluated for changes in opioid prescriptions and multivariate regression identified predictors for chronic postoperative opioid use. RESULTS: Data were available for 27,908 THA patients and 47,220 TKA patients. The proportion of opioid naïve patients before THA or TKA increased significantly (P < 0.001). Median oral morphine equivalents prescribed during the first postoperative year after THA or TKA decreased significantly (P < 0.001). The proportion of patients with chronic postoperative opioid use also decreased for TKA patients (P < 0.001). DISCUSSION: A notable, downward trend was seen in the proportion of patients who received opioids before elective arthroplasty, in the amount of opioid prescribed after surgery, and in TKA patients, the frequency of chronic opioid use after surgery. These findings reflect the effectiveness of efforts to combat the opioid epidemic after elective arthroplasty surgery.

Nonagenarians and Octogenarians Undergoing THA and TKA: A 10-Year Age Difference Increases Rates of In-Hospital Complications But Does Not Affect 90-Day Outcomes.

Background: The population of nonagenarians undergoing total joint arthroplasty (TJA) of the hip or knee is expected to increase, but this population may be reluctant to consider elective surgery because of their advanced age. Purpose: We sought to compare TJA outcomes between nonagenarians and octogenarians with an exact 10-year age difference. Methods: We performed a retrospective chart review, including 129 nonagenarians who underwent primary unilateral TJA for osteoarthritis in a 4-year period at a single institution and who were matched with 381 octogenarians based on sex, body mass index, Charlson Comorbidity Index, replaced joint (hip or knee), and a 10-year age difference. Ninety-day outcomes included Centers for Medicare and Medicaid Services (CMS) defined complications, unscheduled outpatient clinic visits, emergency room (ER) visits, and readmissions. No patients were lost to follow-up. Results: Nonagenarians and octogenarians had comparable rates of CMS complications (10% vs 6.3%, respectively), but nonagenarians had higher rates of CMS mechanical complications (6.2% vs 1.6%). There was 1 death in each group. Nonagenarians had longer hospital stays than octogenarians (4.1 vs 3.0 days, respectively), and a greater risk of in-hospital events and complications (60.5% vs 37.3%, respectively). The groups showed similar rates of unscheduled outpatient visits (14.7% vs 13.9%, respectively), ER visits (12.4 vs 6.6%, respectively), and readmissions (6.2% vs 7.1%, respectively). Conclusions: This retrospective study found higher rates of in-hospital complications in nonagenarians than in matched octogenarians following elective TJA, although the 2 groups showed similar rates of postdischarge complications. Further research in a larger cohort is needed.

Differences in time to return to work among patients undergoing simultaneous versus staged bilateral total knee arthroplasty.

AIMS: Many patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis (OA) in both knees and may consider either simultaneous or staged bilateral TKA. The implications of simultaneous versus staged bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared with the sum of days missed from each operation for patients who underwent staged bilateral TKA. METHODS: The prospective arthroplasty registry at the Hospital for Special Surgery was used. Baseline characteristics and patient-reported outcome scores were evaluated. We used a linear regression model, adjusting for potential confounding variables including age, sex, preoperative BMI, and type of work (sedentary, moderate, high activity, or strenuous), to analyze time lost from work after simultaneous compared with staged bilateral TKA. RESULTS: We identified 152 employed patients who had undergone simultaneous bilateral TKA and 61 who had undergone staged bilateral TKA, and had completed the registry's return to work questionnaire. The simultaneous group missed a mean of 46.2 days (SD 29.1) compared with the staged group who missed a mean total of 68.0 days of work (SD 46.1) when combining both operations. This difference was statistically significant (p < 0.001). In multivariate mixed regression analysis adjusted for age, sex, BMI, American Society of Anesthesiologists status, and type of work, the simultaneous group missed a mean of 16.9 (SD 5.7) fewer days of work compared with the staged group (95% confidence interval 5.8 to 28.1; p = 0.003). CONCLUSION: Employed patients undergoing simultaneous bilateral TKA missed a mean of 17 fewer days of work as a result of their surgical treatment and rehabilitation compared with those undergoing staged bilateral TKA. This information may be useful to surgeons counselling employed patients with bilateral OA of the knee who are considering surgical treatment. Cite this article: Bone Joint J 2021;103-B(6 Supple A):108-112.

The Effect of Sex on Orthopaedic Surgeon Income.

BACKGROUND: Several studies have identified discrepancies in salary between male and female surgeons. Our aim was to investigate the impact of sex on an orthopaedic surgeon's yearly earnings by evaluating stratified income and specialty data from a large sample survey of orthopaedic surgeons. METHODS: Self-reported data were obtained from the 2014 and 2008 American Academy of Orthopaedic Surgeons (AAOS) biennial censuses. Responses were received from 6,805 (24.26%) of those who were surveyed. The census form is a 19-question survey that includes information regarding work status (full time versus part time), sex, years in practice, practice type (private versus academic), specialty, hours worked, case volume, and income. The main outcome evaluated was self-reported income, and a multivariate regression model was used to control for confounding variables. RESULTS: Male surgeons reported higher incomes than female colleagues working equivalent hours ($802,474 versus $560,618; p = 0.016); however, male surgeons reported a greater case volume for the same number of hours. Among surgeons who performed ≥26 procedures per month, male and female surgeons reported comparable incomes ($949,508 versus $872,903; p = 0.649). Incomes of those in practice for >20 years also were comparable. Regression analysis controlling for subspecialty choice, hours worked, work status, case volume, years in practice, and practice setting revealed that income was $62,032.51 less for women than men (p < 0.001). CONCLUSIONS: Income disparity between male and female orthopaedic surgeons remains significant, and the gap increased from 2008 to 2014. Although subspecialty choice, practice setting, years in practice, and amount and distribution of procedures performed can partially explain salary differences, our regression analysis suggests persistence of an income gap based on sex in orthopaedic surgery.

Effects of local vanadium delivery on diabetic fracture healing.

This study evaluated the effect of local vanadyl acetylacetonate (VAC), an insulin mimetic agent, upon the early and late parameters of fracture healing in rats using a standard femur fracture model. Mechanical testing, and radiographic scoring were performed, as well as histomorphometry, including percent bone, percent cartilage, and osteoclast numbers. Fractures treated with local 1.5 mg/kg VAC possessed significantly increased mechanical properties compared to controls at 6 weeks post-fracture, including increased torque to failure (15%; p = 0.046), shear modulus (89%; p = 0.043), and shear stress (81%; p = 0.009). The radiographic scoring analysis showed increased cortical bridging at 4 weeks and 6 weeks (119%; p = 0.036 and 209%; p = 0.002) in 1.5 mg/kg VAC treated groups. Histomorphometry of the fracture callus at days 10 and 14 showed increased percent cartilage (121%; p = 0.009 and 45%; p = 0.035) and percent mineralized tissue (66%; p = 0.035 and 58%; p = 0.006) with local VAC treated groups compared to control. Additionally, fewer osteoclasts were observed in the local VAC treated animals as compared to controls at day 14 (0.45% ± 0.29% vs. 0.83% ± 0.36% of callus area; p = 0.032). The results suggest local administration of VAC acts to modulate osteoclast activity and increase percentage of early callus cartilage, ultimately enhancing mechanical properties comparably to non-diabetic animals treated with local VAC. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2174-2180, 2017.

Local Zinc Chloride Release From a Calcium Sulfate Carrier Enhances Fracture Healing.

BACKGROUND: This study examined the efficacy of calcium sulfate (CaSO4) as a carrier for intramedullary delivery of zinc chloride (ZnCl2) to treat fracture healing in a BB Wistar rat model. A non-carrier-mediated injection of 3.0 mg/kg of ZnCl2 has previously been shown to enhance fracture healing. METHODS: A heterogeneous mixture of ZnCl2 and CaSO4 was administered into the intramedullary femoral canal and a mid-diaphyseal femur fracture was created unilaterally. Early and late parameters of fracture healing were assessed using biomechanical testing, radiographic scoring, quantitative histomorphometry (for percentage of new cartilage and bone within the fracture callus), and long-term histologic evaluation. RESULTS: Fractures treated with 1.0 mg/kg of ZnCl2/CaSO4 demonstrated a significantly higher maximum torque to failure compared with both CaSO4 (P = 0.048) and saline (P = 0.005) controls at 4 weeks postfracture (396.4 versus 251.3 versus 178.7 N mm, respectively). Statistically significant increases in torsional rigidity, effective shear modulus, and effective shear stress were also found, as well as a 3.5 times increase in radiographic score (based on bone union). Histologic examination of the fracture callus indicated enhanced chondrogenesis at day 14 postfracture, with increased percent cartilage for the ZnCl2/CaSO4 group compared with saline (P = 0.0004) and CaSO4 (P = 0.0453) controls. Long-term radiographic and histologic evaluation revealed no abnormal bone formation or infection up to 12 weeks postoperatively. CONCLUSIONS: The effective dose of ZnCl2 augmentation for the enhancement of fracture healing in rats was reduced 3-fold in this study compared with previous findings. Furthermore, CaSO4 acted synergistically with ZnCl2 to increase the mechanical strength and stability at the fracture site.