Nearly 14-Fold Increased Risk of Manipulation Under Anesthesia After Total Knee Arthroplasty When Previous Contralateral Total Knee Arthroplasty Required Manipulation Under Anesthesia.

BACKGROUND: Stiffness remains a common complication after primary total knee arthroplasty (TKA). Manipulation under anesthesia (MUA) is the gold standard treatment for early postoperative stiffness; however, there remains a paucity of data on the risk of MUA after primary TKA if a prior contralateral TKA required MUA. METHODS: We performed a retrospective review of 3,102 patients who had staged primary TKAs between 2016 and 2021. The mean body mass index was 33 (range, 18 to 59) and the mean age was 67 years (range, 24 to 91). The mean preoperative range of motion for the first TKA was 2 to 104°, and for the contralateral TKA was 1 to 107°. The primary outcomes were MUA following first and second primary TKAs. Multivariable Poisson regressions were used to evaluate associations between risk factors and outcomes. RESULTS: The rate of MUA after the first TKA was 2.6% (n = 83 of 3,102) and 1.3% (n = 40 of 3,102) after the contralateral TKA. After adjustment, there was a nearly 14-fold higher rate of MUA after the second TKA if the patient had an MUA after the first TKA (relative risk, 13.80; 95% CI [confidence interval], 7.14 to 26.66). For the first TKA, increasing age (adjusted risk ratio [ARR], 0.65; 95% CI, 0.50 to 0.83) and increasing body mass index (ARR, 0.65; 95% CI, 0.47 to 0.90) were associated with lower risk for MUA. For the second TKA, increasing age was associated with a lower risk of MUA (ARR, 0.60; 95% CI, 0.45 to 0.80). CONCLUSIONS: For patients undergoing staged bilateral TKA, patients who undergo MUA following the first primary TKA are nearly 14-fold more likely to undergo an MUA following the contralateral primary TKA than those who did not have an MUA after their first TKA.

Systematic Review of Gender and Sex Terminology Use in Arthroplasty Research: There Is Room for Improvement.

BACKGROUND: There is increasing appreciation of the distinction between gender and sex as well as the importance of accurately reporting these constructs. Given recent attention regarding transgender and gender nonconforming (TGNC) and intersex identities, it is more necessary than ever to understand how to describe these identities in research. This study sought to investigate the use of gender- and sex-based terminology in arthroplasty research. METHODS: The 5 leading orthopaedic journals publishing arthroplasty research were reviewed to identify the first twenty primary clinical research articles on an arthroplasty topic published after January 1, 2022. Use of gender- or sex-based terminology, whether use was discriminate, and whether stratification or adjustment based on gender or sex was performed, were recorded. RESULTS: There were 98 of 100 articles that measured a construct of gender or sex. Of these, 15 articles used gender-based terminology, 45 used sex-based terminology, and 38 used a combination of gender- and sex-based terminology. Of the 38 articles using a combination of terminology, none did so discriminately. All articles presented gender and sex as binary variables, and 2 attempted to explicitly define how gender or sex were defined. Of the 98 articles, 31 used these variables for statistical adjustments, though only 6 reported stratified results. CONCLUSIONS: Arthroplasty articles infrequently describe how gender or sex was measured, and frequently use this terminology interchangeably. Additionally, these articles rarely offer more than 2 options for capturing variation in sex and gender. Future research should be more precise in the treatment of these variables to improve the quality of results and ensure findings are patient-centered and inclusive.

Predicting Postoperative Anemia and Blood Transfusion Following Total Knee Arthroplasty.

BACKGROUND: While transfusion and clinically relevant anemia after elective primary total knee arthroplasty (TKA) are uncommon, there remains a question of who needs postoperative hemoglobin monitoring, especially in the setting of increasing incidence of outpatient TKA. The purpose of this study was to create predictive models for postoperative anemia and blood transfusion to guide clinical decision-making. METHODS: The records of consecutive TKA patients were reviewed from February 2016 to December 2020 at a single institution. Two multivariable logistic regression models, for postoperative anemia (hemoglobin < 10 g/dL) and allogeneic blood transfusion included 8 variables: age, sex, body mass index, preoperative hemoglobin level, tranexamic acid total dose, American Society of Anesthesiologists level, operative time, and drain use. Model performance was assessed using accuracy, area under the curve (AUC), sensitivity, and specificity. RESULTS: The records of 14,901 patients were included in this study. Patients had a mean (± standard deviation) age of 67.9 ± 9.2 years and mean body mass index of 31.3 ± 6.5 kg/m2. The postoperative anemia model had an accuracy of 88% (95% confidence interval [CI], 87%-89%) and AUC of 0.88 (95% CI, 0.87-0.89). The blood transfusion model had an accuracy of 97% (95% CI, 96%-97%) and AUC of 0.90 (95% CI, 0.87-0.93). CONCLUSION: The postoperative anemia and blood transfusion model accurately predicted each outcome. Patients with less than a 5% probability of postoperative anemia may not benefit from a complete blood count at postoperative day 1. Application of these criteria may save the healthcare system hundreds of millions of dollars. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Providence Bracing: Predicting the Progression to Surgery in Patients With Braced Idiopathic Scoliosis.

BACKGROUND: Idiopathic scoliosis (IS) is a common spinal abnormality, in which orthotic management can reduce progression to surgery. However, predictors of bracing success are still not fully understood. We studied a large patient population treated with the nighttime Providence orthosis, utilizing multivariable logistic regression to assess results and predict future spine surgery. METHODS: We retrospectively reviewed patients with IS meeting Scoliosis Research Society inclusion and assessment criteria presenting from April 1994 to June 2020 at a single institution and treated with a Providence orthosis. A predictive logistic regression model was developed utilizing the following candidate features: age, sex, body mass index, Risser classification, Lenke classification, curve magnitude at brace initiation, percentage correction in a brace, and total months of brace use. Model performance was assessed using the area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity. The importance of individual features was assessed using the variable importance score. RESULTS: There were 329 consecutive patients with IS with a mean age of 12.8 ± 1.4 years that met inclusion and assessment criteria. Of these, 113 patients (34%) ultimately required surgery. The model's area under the curve (AUC) was 0.72 on the testing set, demonstrating good discrimination. The initial curve magnitude (Importance score: 100.0) and duration of bracing (Importance score: 82.4) were the 2 most predictive features for curve progression leading to surgery. With respect to skeletal maturity, Risser 1 (Importance score: 53.9) had the most predictive importance for future surgery. For the curve pattern, Lenke 6 (Importance score: 52.0) had the most predictive importance for future surgery. CONCLUSION: Out of 329 patients with IS treated with a Providence nighttime orthosis, 34% required surgery. This is similar to the findings of the BrAist study of the Boston orthosis, in which 28% of monitored braced patients required surgery. In addition, we found that predictive logistic regression can evaluate the likelihood of future spine surgery in patients treated with the Providence orthosis. The severity of the initial curve magnitude and total months of bracing were the 2 most important variables when assessing the probability of future surgery. Surgeons can use this model to counsel families on the potential benefits of bracing and risk factors for curve progression.

Reversible association with motor proteins (RAMP): A streptavidin-based method to manipulate organelle positioning.

We report the development and characterization of a method, named reversible association with motor proteins (RAMP), for manipulation of organelle positioning within the cytoplasm. RAMP consists of coexpressing in cultured cells (i) an organellar protein fused to the streptavidin-binding peptide (SBP) and (ii) motor, neck, and coiled-coil domains from a plus-end-directed or minus-end-directed kinesin fused to streptavidin. The SBP-streptavidin interaction drives accumulation of organelles at the plus or minus end of microtubules, respectively. Importantly, competition of the streptavidin-SBP interaction by the addition of biotin to the culture medium rapidly dissociates the motor construct from the organelle, allowing restoration of normal patterns of organelle transport and distribution. A distinctive feature of this method is that organelles initially accumulate at either end of the microtubule network in the initial state and are subsequently released from this accumulation, allowing analyses of the movement of a synchronized population of organelles by endogenous motors.

Substantial Inconsistency and Variability Exists Among Minimum Clinically Important Differences for Shoulder Arthroplasty Outcomes: A Systematic Review.

BACKGROUND: As the value of patient-reported outcomes becomes increasingly recognized, minimum clinically important difference (MCID) thresholds have seen greater use in shoulder arthroplasty. However, MCIDs are unique to certain populations, and variation in the modes of calculation in this field may be of concern. With the growing utilization of MCIDs within the field and value-based care models, a detailed appraisal of the appropriateness of MCID use in the literature is necessary and has not been systematically reviewed. QUESTIONS/PURPOSES: We performed a systematic review of MCID quantification in existing studies on shoulder arthroplasty to answer the following questions: (1) What is the range of values reported for the MCID in commonly used shoulder arthroplasty patient-reported outcome measures (PROMs)? (2) What percentage of studies use previously existing MCIDs versus calculating a new MCID? (3) What techniques for calculating the MCID were used in studies where a new MCID was calculated? METHODS: The Embase, PubMed, and Ovid/MEDLINE databases were queried from December 2008 through December 2020 for total shoulder arthroplasty and reverse total shoulder arthroplasty articles reporting an MCID value for various PROMs. Two reviewers (DAK, MAM) independently screened articles for eligibility, specifically identifying articles that reported MCID values for PROMs after shoulder arthroplasty, and extracted data for analysis. Each study was classified into two categories: those referencing a previously defined MCID and those using a newly calculated MCID. Methods for determining the MCID for each study and the variability of reported MCIDs for each PROM were recorded. The number of patients, age, gender, BMI, length of follow-up, surgical indications, and surgical type were extracted for each article. Forty-three articles (16,408 patients) with a mean (range) follow-up of 20 months (0.75 to 68) met the inclusion criteria. The median (range) BMI of patients was 29.3 kg/m2 (28.0 to 32.2 kg/m2), and the median (range) age was 68 years (53 to 84). There were 17 unique PROMs with MCID values. Of the 112 MCIDs reported, the most common PROMs with MCIDs were the American Shoulder and Elbow Surgeons (ASES) (23% [26 of 112]), the Simple Shoulder Test (SST) (17% [19 of 112]), and the Constant (15% [17 of 112]). RESULTS: The ranges of MCID values for each PROM varied widely (ASES: 6.3 to 29.5; SST: 1.4 to 4.0; Constant: -0.3 to 12.8). Fifty-six percent (24 of 43) of studies used previously established MCIDs, with 46% (11 of 24) citing one study. Forty-four percent (19 of 43) of studies established new MCIDs, and the most common technique was anchor-based (37% [7 of 19]), followed by distribution (21% [4 of 19]). CONCLUSION: There is substantial inconsistency and variability in the quantification and reporting of MCID values in shoulder arthroplasty studies. Many shoulder arthroplasty studies apply previously published MCID values with variable ranges of follow-up rather than calculating population-specific thresholds. The use of previously calculated MCIDs may be acceptable in specific situations; however, investigators should select an anchor-based MCID calculated from a patient population as similar as possible to their own. This practice is preferable to the use of distribution-approach MCID methods. Alternatively, authors may consider using substantial clinical benefit or patient-acceptable symptom state to assess outcomes after shoulder arthroplasty. CLINICAL RELEVANCE: Although MCIDs may provide a useful effect-size based alternative to the traditional p value, care must be taken to use an MCID that is appropriate for the particular patient population being studied.

Does Low Back Pain Improve Following Total Hip Arthroplasty?

BACKGROUND: Frequently, patients indicated for total hip arthroplasty (THA) present with low back pain (LBP) and hip pain. The purpose of this study was to compare patients whose back pain resolved after THA with those where back pain did not resolve and identify how to predict this using spinopelvic parameters. METHODS: We reviewed a series of 500 patients who underwent THA for unilateral hip osteoarthritis by 2 surgeons. Patients underwent biplanar standing and sitting EOS radiographs pre-operatively. Patients with previous spine surgery or femoral neck fracture were excluded. Demographic data was analyzed at baseline. The Oswestry Disability Index (ODI) scores were calculated pre-operatively and at 1 year postoperatively. Spinopelvic parameters included, pelvic incidence and sacral slope (SS) change from standing to sitting. RESULTS: Two hundred and four patients (41%) had documented LBP before THA. The Oswestry Disability Index (ODI) for patients improved from 38.9 ± 17.8 pre-operatively to 17.0 ± 10.6 at 1 year post-operatively (P < .001). At 1- and 2-year follow-up, resolution of back pain occurred in 168 (82.4%) and 187 (91.2%) patients, respectively. Pelvic incidence was not predictive of back pain resolution. All patients whose back pain resolved had a sacral slope change from standing to sitting of >10°, while those patients whose back pain did not resolve had a change of <10°. CONCLUSION: This study demonstrates that symptomatic low back pain (LBP) resolves in 82% of patients after THA. The results of this study may be used to counsel patients on back pain and its resolution following total hip replacement.

Projected Economic Burden of Periprosthetic Joint Infection of the Hip and Knee in the United States.

BACKGROUND: In addition to the significant morbidity and mortality associated with periprosthetic joint infection (PJI), the cost of treating PJI is substantial. Prior high-quality national estimates of the economic burden of PJI utilize data up to 2009 to project PJI growth in the United States through 2020. Now in the year 2020, it is appropriate to evaluate these past projections and incorporate the latest available data to better understand the current scale and burden of PJI in the United States. METHODS: The Nationwide Inpatient Sample (2002-2017) was used to identify rates and associated inpatient costs for primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) and PJI-related revision TKA and THA. Poisson regression was utilized to model past growth and project future rates and cost of PJI of the hip and knee. RESULTS: Using the most recent data, the combined annual hospital costs related to PJI of the hip and knee were estimated to be $1.85 billion by 2030. This includes $753.4 million for THA PJI and $1.1 billion for TKA PJI, in that year. Increases in PJI costs are mainly attributable to increases in volume. Although the growth in incidence of primary THA and TKA has slowed in recent years, the incidence of PJI and the cost per case of PJI remained relatively constant from 2002 to 2017. DISCUSSION: Understanding the current and potential future financial burden of PJI for surgeons, patients, and healthcare systems is essential. There is an urgent need for efficacious preventive strategies in reducing rates of PJI after THA and TKA.

Three Degrees External to the Posterior Condylar Axis Has Little Relevance in Femoral Component Rotation: A Computed Tomography-Based Total Knee Arthroplasty Simulation Study.

BACKGROUND: Femoral component rotation in total knee arthroplasty (TKA) has a significant impact on balance and patellofemoral kinematics. However, normal anatomic relationships between rotational axes are poorly understood. As such, we sought to characterize anatomic femoral rotational axes in patients undergoing primary TKA. METHODS: We identified 100 patients who underwent a primary TKA with a preoperative computed tomography scan. The angles between the surgical epicondylar axis (SEA) and the anterior-posterior (AP) axis to the posterior condylar axis (PCA) were measured independently by a musculoskeletal fellowship-trained radiologist and a fellowship-trained arthroplasty surgeon. We simulated an ideal TKA in which the femoral component was placed exactly 3° external to the PCA and measured resulting rotation. RESULTS: The SEA was on average 1.5° externally rotated to the PCA (range 3.1° internal to 7.0° external). The AP axis was on average 4.5° externally rotated to the PCA (range 2.3° internal to 10.3° external). The AP axis was a mean 2.7° externally rotated to the SEA (range 6.3° internal to 10.3° external). Routinely setting femoral rotation 3° external to the PCA would result in only 51 (51%) TKAs within ±2° of the SEA and 23 (23%) femoral components internally rotated relative to the SEA. CONCLUSION: Normal anatomic rotational axes of arthritic knees are highly variable, with a 10° range in the SEA and 16° range in the AP axis. Routinely setting femoral rotation 3° external to the PCA will yield significant error in aligning the femoral component with either the SEA or AP axis.

Origins of Small Proton Chemical Shift Differences in Monodeuterated Methyl Groups.

We have recently shown that the small proton chemical shift difference in 2-methyl-1-(methyl-d)piperidine supports a long-lived nuclear spin state. To identify additional candidate molecules with CH2D groups exhibiting accessible long-lived states, and to investigate the factors governing the magnitude of the shift differences, we report a computational and experimental investigation of methyl rotational equilibria and proton chemical shifts in a variety of 2-substituted 1-(methyl-d)piperidines. The polarity and size of the 2-substituent affect the 1,2-stereoisomeric relationship, and consequently, the strength of the rotational asymmetry within the CH2D group. Nonpolar and large 2-substituents prefer the equatorial position, and relatively large shift differences (i.e., > 13 ppb) are observed. Polar and small substituents, however, increasingly prefer the axial position, and medium to small shift differences (i.e., 0 to 9 ppb) are observed. In addition, the diastereotopic CH2D proton chemical shift difference for tricarbonyl(1-chloro-2-deuteriomethylbenzene) chromium(0) was computed, showing that reasonable predictions of these small shift differences can be extended to more complex, organometallic species.

Duane syndrome in association with congenital disorder of glycosylation type Ig (ALG12-CDG).

Congenital disorders of glycosylation type I (CDG-I) are a group of autosomal recessive genetic multisystem disorders that arise from defective glycoprotein biosynthesis. Although ocular abnormalities have been described in patients with CDG-I, few ocular abnormalities have been associated with ALG12-CDG (CDG-Ig), a rare subtype of CDG-I. We report a case of Duane syndrome, a congenital strabismus syndrome, in a 17-year-old young woman with ALG12-CDG.

Less common than expected: late displacement after minimally displaced pediatric lateral condyle fractures of the elbow.

The incidence of late displacement among pediatric lateral condyle fractures has been described as 1.3-26%. However, prior studies are limited by small cohort sizes. The aim of this study was to determine the rate of late displacement and delayed union among lateral condyle fractures following immobilization in a large cohort and to establish additional radiographic criteria to help surgeons choose between immobilization and operative fixation for minimally displaced fractures. We performed a dual-center retrospective study of patients with lateral condyle fractures between 1999 and 2020. Patient demographics, injury mechanism, time to orthopedic presentation, duration of cast immobilization, and complications following casting were recorded. There were 290 patients with lateral condyle fractures included. The initial management in 61% of patients (178/290) was nonoperative, of which four had delayed displacement at follow-up and two developed delayed union requiring surgery (failure in 6/178, 3.4%). The mean displacement on the anteroposterior view was 1.3 ±â€…1.1 mm and the lateral view was 0.50 ±â€…1.0 mm in the nonoperative cohort. In the operative cohort, the mean displacement on AP was 6.6 ±â€…5.4 mm and the lateral view was 5.3 ±â€…4.1 mm. Our analysis found the rate of late displacement in patients treated with immobilization was lower than previously reported (2.5%; 4/178). The mean displacement on the lateral film in the cast immobilization cohort was 0.5 mm, suggesting that necessitating near anatomic alignment on the lateral film to consider nonoperative management may lead to a lower incidence of late displacement than previously reported. Level of evidence: Level III, retrospective comparative study.

No difference in stability among various knee flexion angles during fixation of anterolateral ligament reconstruction or lateral extra-articular tenodesis: A systematic review and meta-analysis of biomechanical studies.

Purpose: The purpose of this study was to investigate the effect of anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) fixation at low versus high flexion angles during anterior cruciate ligament reconstruction (ACLR) on rotation or translational knee stability. Methods: The inclusion criteria for this study were (1) cadaveric study, (2) cadaveric specimens underwent ACLR, (3) cadaveric specimen underwent ALLR or LET and (4) specimen preparation technique described the knee flexion angle at the time of ALLR or LET tensioning and fixation. A priori, 'low flexion' was defined as 0-30° and 'high flexion' was defined as 60-90° at graft fixation. Main outcomes of interest included internal rotation and anterior translation. Results: Data from 92 cadaveric knees (from 9 studies) were extracted and included in the meta-analysis. The mean pooled value for internal rotation was 10.1° (95% confidence interval [CI], 5.7-14.5°) for the low flexion group and 11.5° (95% CI, 7.4-15.7°) for the high flexion group (n.s.). The mean pooled value for anterior translation was 4.3 mm (95% CI, 0.5-8.1 mm) for the low flexion group and 3.0 mm (95% CI, 1.1-5.0 mm) for the high flexion group (n.s.). Conclusion: This meta-analysis of existing biomechanical research found that the rotational and translational stability of the knee were not significantly different between scenarios in which ALLR or LET fixation was performed at low knee flexion angles (0-30°) versus high knee flexion angles (60-90°). Level of Evidence: Level IV.

Magnetic Resonance Imaging Patterns of Common Injuries in Pediatric and Adolescent Athletes.

Injuries in pediatric and adolescent athletes continue to rise in the United States, with increases in year-round sports participation, earlier sport specialization, and inadequate access to neuromuscular training programs. In this setting, the use of magnetic resonance imaging (MRI) provides a critical diagnostic tool. This review article describes the utility of MRI in diagnosing common pediatric and adolescent sports injuries and presents imaging findings associated with these pathologies.

Prevalence of Concomitant Injuries by Sport in Pediatric Patients With ACL Rupture.

Background: Although the risk of concomitant injury with anterior cruciate ligament (ACL) tears as a function of specific sports participation has been studied in adults, the topic has not been examined in pediatric and adolescent patients. Purpose/Hypothesis: The purpose of the study was to determine if certain sports were associated with a higher risk of concomitant injuries in the setting of an ACL tear. It was hypothesized that the risk of concomitant injuries with ACL tears will differ by type of sport participation in the pediatric population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients ≤18 years old from 2 tertiary children's hospitals who had undergone primary ACL reconstruction between 2006 and 2018 were included. Sport at the time of injury, demographic factors, and injury pattern (medial meniscal [MM] tears, lateral meniscal [LM] tears, posterior cruciate ligament [PCL] tears, medial collateral ligament [MCL] tears, lateral collateral ligament [LCL] tears, and any concomitant injury) were identified. Results: A total of 855 patients with a mean age of 15.5 ± 1.7 years (range, 7-22 years) met the inclusion criteria. Of the included patients, 353 (41.3%) had an isolated ACL tear. A concomitant MM tear was identified in 27.6% of patients, LM tear in 42.9%, PCL injury in 0.4%, MCL injury in 3.0%, and LCL injury in 0.5%. There was no difference in the likelihood of concomitant MM injuries by sex (29.3% for male patients vs 26% for female patients; P = .31) or by sex within basketball (29.3% for male patients vs 25.6% for female patients; P = .96) or soccer (32.3% vs 26.3%; P = .06). Boys had higher proportions of LM injuries overall (51.7% for male patients vs 34.6% for female patients; P < .001) but not within the basketball subgroup (50.5% vs 40.0%; P = .86) or the soccer subgroup (59.7% vs 40.0%; P = .19). No statistically significant associations were found between patient age and specific ACL concomitant injury patterns. When stratifying by body mass index, it was found overweight and obese individuals constituted a greater proportion of LM (49.6% vs 39.1%; P = .01) but not MM (29.4% vs 25.5%; P = .28) injuries when compared to normal-weight patients. Using basketball as the comparison group, soccer and football injuries were 18% more likely to result in any concomitant injury, including concomitant MM, LM, PCL, MCL, and LCL injuries. Conclusion: In the pediatric population, soccer and football players were more likely to present with a concomitant injury in addition to ACL injury relative to basketball players. This study aids in understanding sport-associated ACL injury patterns and can help physicians with patient counseling and injury prevention.

Knee Flexion Angle of Fixation During Anterolateral Ligament Reconstruction or Lateral Extra-articular Tenodesis: A Systematic Review and Meta-analysis of Lateral Extra-articular Reinforcement Techniques Performed in Conjunction With ACL Reconstruction.

Background: Anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) is being used more frequently in conjunction with anterior cruciate ligament reconstruction (ACLR). However, the knee flexion angle at which fixation of ALLR or LET is performed during the procedure is quite variable based on existing technique descriptions. Purpose/Hypothesis: The purpose of this study was to identify whether flexion angle at the time of ALLR/LET fixation affected postoperative outcomes in a clinical population. It was hypothesized that ALLR/LET fixation at low versus high flexion angles would lead to no statistically significant differences in patient-reported outcome measures and graft failure rates. Study Design: Systematic review; Level of evidence, 4. Methods: The PubMed, Embase, and Cochrane Library databases were searched according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify published clinical studies of ACLR with ALLR/LET in which the knee flexion angle at the time of ALLR/LET was reported. A priori, low flexion was defined as 0° to 30°, and high flexion was defined as 60° to 90°. Studies were excluded if the flexion angle was between 31° and 59° because these angles constituted neither low nor high flexion angles and including them in an analysis of high versus low flexion angle at fixation would have biased the study results toward the null. The overall risk of bias was assessed using the Newcastle-Ottawa Scale. The pooled results of the studies were analyzed using the International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores, along with reported graft failure rates. Results: A total of 32 clinical studies (5230 patients) met inclusion criteria: 22 studies (1999 patients) in the low-flexion group and 10 studies (3231 patients) in the high-flexion group. The median Newcastle-Ottawa Scale score was 6. Comparisons of patients with a low flexion angle versus a high flexion angle demonstrated no differences in the IKDC (P = .84), Lysholm (P = .67), or Tegner (P = .44) scores or in graft failure (3.4% vs 4.1%, respectively; P = .69). Conclusion: The results of this review indicated that ACLR performed in conjunction with ALLR/LET provides good to excellent patient-reported outcomes and low graft failure rates when ALLR/LET fixation is performed in either low or high knee flexion.

Does a Uni "Feel Better" than a Total Knee? Not Necessarily, When Using Modern Implant Designs.

Background: When comparing functional outcomes of patients with unicompartmental knee arthroplasty (UKA) versus total knee arthroplasty (TKA), studies often report the UKA as the preferred procedure; however, recent improvements in the design of modern TKA implants have aimed at narrowing this gap. Purpose: We sought to compare the "feel" of modern TKA implants to that of UKA, using the Forgotten Joint Score (FJS), a validated patient-reported outcome measure. Methods: We performed a retrospective review of patients who underwent TKA and UKA at 2 institutions between 2014 and 2017. All UKA procedures were robotic arm-assisted with a single implant, "traditional TKAs" were performed using traditional posterior-stabilized implants, and "modern TKAs" were performed using posterior-stabilized implants with a modern design. Differences in FJS were assessed using 1-way analysis of variance and independent 2-sample t tests. Results: A total of 600 patients were included in our study, with 200 patients in each surgical subcategory. Mean age was 62.8 ± 10.2 years and mean body mass index was 29.9 ± 4.9. Modern TKA and UKA had similar FJS at 1 year. While modern TKA had a significantly higher FJS than traditional TKA, UKA did not have a significantly higher FJS than traditional TKA. Conclusion: Our retrospective analysis found no significant differences in the FJS of patients who underwent UKA and TKA with a modern design; however, both had superior scores than traditional TKA designs. This finding suggests that modern TKA designs may have the potential to achieve the natural feeling that is typically associated with joint-conserving surgeries such as UKA, although longer follow-up is necessary.

No difference in patient reported outcomes between cohorts undergoing lesion-specific surgery for osteochondritis dissecans of the knee.

Introduction: There is a paucity of data on patient reported outcome measures (PROMs) associated with surgical treatment of osteochondritis dissecans (OCD). As a result, preoperative patient and family counseling regarding expected outcomes is difficult. The purpose of this study was to compare pre-to post-operative changes in PROMs amongst cohorts of patients with OCD that underwent one of three lesion-specific surgical treatments: 1) transarticular drilling for stable lesions, 2) drilling and fixation for unstable lesions 3) grafting for unsalvageable lesions. Methods: The electronic medical records of pediatric and adolescent patients with knee OCD, at a single institution between January 2017 and August 2019, were reviewed. Patients were categorized into one of three surgical groups, with initial determination confirmed at the time of surgery during diagnostic knee arthroscopy. Differences between groups were assessed with one-way analysis of variance (ANOVA). Results: Of the 78 patients included in this study, 49 (62.8%) were male with a mean age of 13.5 ± 2.2 years. There was no significant difference between the surgical groups for baseline HSS Pedi-FABS (P = 0.58) or PROMIS Mobility (P = 0.47). There were no significant differences in PROMIS PI scores at baseline (P = 0.32), at latest follow-up (P = 0.72), or in interval change from baseline to follow-up (P = 0.42), between the three surgical groups. Conclusion: Lesion-specific surgical management of OCD led to similar improvements in PROMIS PI at a minimum of one-year follow-up. These results may better allow surgeons to reassure patients and families that outcomes are similar when lesions are treated through a lesion-specific algorithm. Level of evidence: Level IV: Retrospective cohort study.