All-Optical Noise Spectroscopy of a Solid-State Spin.

Noise spectroscopy elucidates the fundamental noise sources in spin systems, thereby serving as an essential tool toward developing spin qubits with long coherence times for quantum information processing, communication, and sensing. But existing techniques for noise spectroscopy that rely on microwave fields become infeasible when the microwave power is too weak to generate Rabi rotations of the spin. Here, we demonstrate an alternative all-optical approach to performing noise spectroscopy. Our approach utilizes coherent Raman rotations of the spin state with controlled timing and phase to implement Carr-Purcell-Meiboom-Gill pulse sequences. Analyzing the spin dynamics under these sequences enables us to extract the noise spectrum of a dense ensemble of nuclear spins interacting with a single spin in a quantum dot, which has thus far been modeled only theoretically. By providing spectral bandwidths of over 100 MHz, our approach enables studies of spin dynamics and decoherence for a broad range of solid-state spin qubits.

Correlations between Cascaded Photons from Spatially Localized Biexcitons in ZnSe.

Radiative cascades emit correlated photon pairs, providing a pathway for the generation of entangled photons. The realization of a radiative cascade with impurity atoms in semiconductors, a leading platform for the generation of quantum light, would therefore provide a new avenue for the development of entangled photon pair sources. Here we demonstrate a radiative cascade from the decay of a biexciton at an impurity-atom complex in a ZnSe quantum well. The emitted photons show clear temporal correlations revealing the time-ordering of the cascade. Our result establishes impurity atoms in ZnSe as a potential platform for photonic quantum technologies using radiative cascades.

Primary reverse total shoulder arthroplasty performed for glenohumeral arthritis: does glenoid morphology matter?

BACKGROUND: Indications for reverse total shoulder arthroplasty (RTSA) have expanded to include primary glenohumeral osteoarthritis (GHOA) with an intact rotator cuff. Limited evidence exists on RTSA in patients with primary GHOA and no posterior glenoid wear (Walch A1, A2, and B1 morphologies). The purpose of this retrospective cohort study was to determine if glenoid morphology is associated with clinical outcomes in patients undergoing RTSA for primary GHOA. METHODS: A retrospective review of prospectively collected data was performed in patients undergoing primary RTSA for GHOA with a minimum of 2-year clinical follow-up. Preoperative computed tomography and magnetic resonance imaging were used to categorize glenoid morphology as described by the modified Walch classification. Pre- and postoperative American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Single Assessment Numeric Evaluation (SANE), visual analog scale (VAS) pain scores, and range of motion (ROM) measurements were compared across Walch glenoid subtypes. The percentage of patients that reached previously established clinically significant thresholds for minimal clinically important difference (MCID) and substantial clinical benefit (SCB) was also comparatively assessed. Multivariable analysis was used to evaluate the association between glenoid morphology and postoperative ASES score while controlling for potentially confounding variables. RESULTS: Of the 247 consecutive patients, 197 were available at a minimum 2-year follow-up (80%). Significant improvements were seen in ASES, VAS pain, SANE, and ROM from baseline to final postoperative follow-up in the combined patient cohort (all P < .001). Most (98.0%) patients reached MCID, and 90.9% of patients reached SCB for ASES threshold. No significant differences were found among Walch subtypes in terms of preoperative to postoperative improvement in ASES (P = .39), SANE (P = .4), VAS pain (P = .49), forward elevation (P = .77), external rotation (P = .45), or internal rotation (P= 0.1). The only significant difference in postoperative outcomes between Walch glenoid subtypes was higher postoperative ASES scores among type B3 glenoids compared with type A1 glenoids (P = .03) on univariate analysis. However, no individual Walch glenoid subtype was associated with lower postoperative ASES scores on multivariable analysis (P > .05). CONCLUSION: Primary RTSA provides excellent short-term outcomes in patients with glenohumeral arthritis with intact rotator cuff, regardless of the degree of preoperative glenoid deformity. Surgeons can use these data to support the use of RTSA for glenohumeral arthritis in a more standardized way.

Optomechanics with levitated particles.

Optomechanics is concerned with the use of light to control mechanical objects. As a field, it has been hugely successful in the production of precise and novel sensors, the development of low-dissipation nanomechanical devices, and the manipulation of quantum signals. Micro- and nano-particles levitated in optical fields act as nanoscale oscillators, making them excellent low-dissipation optomechanical objects, with minimal thermal contact to the environment when operating in vacuum. Levitated optomechanics is seen as the most promising route for studying high-mass quantum physics, with the promise of creating macroscopically separated superposition states at masses of 106 amu and above. Optical feedback, both using active monitoring or the passive interaction with an optical cavity, can be used to cool the centre-of-mass of levitated nanoparticles well below 1 mK, paving the way to operation in the quantum regime. In addition, trapped mesoscopic particles are the paradigmatic system for studying nanoscale stochastic processes, and have already demonstrated their utility in state-of-the-art force sensing.

Higher order correlations in a levitated nanoparticle phonon laser.

We present theoretical and experimental investigations of higher order correlations of mechanical motion in the recently demonstrated optical tweezer phonon laser, consisting of a silica nanosphere trapped in vacuum by a tightly focused optical beam [R. M. Pettit et al., Nature Photonics 13, 402 (2019)]. The nanoparticle phonon number probability distribution is modeled with the master equation formalism in order to study its evolution across the lasing threshold. Up to fourth-order equal-time correlation functions are then derived from the probability distribution. Subsequently, the master equation is transformed into a nonlinear quantum Langevin equation for the trapped particle's position. This equation yields the non-equal-time correlations, also up to fourth order. Finally, we present experimental measurements of the phononic correlation functions, which are in good agreement with our theoretical predictions. We also compare the experimental data to existing analytical Ginzburg-Landau theory where we find only a partial match.

Cartilage damage at the time of anterior cruciate ligament reconstruction is associated with weaker quadriceps function and lower risk of future ACL injury.

PURPOSE: To determine whether articular cartilage damage noted at the time of primary anterior cruciate ligament reconstruction (ACLR) affects the likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery or risk of recurrent ACL injury. METHODS: Five hundred and eight patients underwent primary ACLR and diagnostic arthroscopy. All identified cartilage lesions were graded using the Outerbridge system. All patients underwent isokinetic strength testing. The association between cartilage Outerbridge grade and a ≥ 90% Limb Symmetry Index (LSI) and recurrent ACL injury risk at mean 38.7 month follow-up (SD 31.8) was evaluated via multivariate regression analysis. RESULTS: Grade 2 or higher damage was present in 394 (77.5%) of patients, grade 3 or higher in 143 (28.1%) and grade 4 in 83 (16.4%) at time of ACLR. Ipsilateral ACLR graft rupture occurred in 31 (6.1%) of patients. Contralateral ACL injury occurred in 19 (3.7%). Patients with grade 2 or higher damage were significantly less likely to meet an LSI goal of ≥ 90% for fast (300°/s) isokinetic extension. There was no association with slow isokinetic extension. Cartilage lesion severity at or beyond grade 2 had a similar effect on isokinetic testing results regardless of compartment involvement or performance of microfracture. Patients with grade 2-4 cartilage damage were less likely to sustain a second ipsilateral ACL injury or a contralateral native ACL injury. CONCLUSIONS: Cartilage damage seen at time of ACL reconstruction is common and associated with lower likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery. However, lower recurrent ACL injury rates are seen in patients with concurrent cartilage damage. These data may inform future clinical decisions regarding operative managment of recurrent ACL injuries. LEVEL OF EVIDENCE: III.

Risk Factors for Mid-Flexion Instability After Total Knee Arthroplasty: A Systematic Review.

BACKGROUND: Mid-flexion instability after total knee arthroplasty (TKA) is a clinical entity that is not well studied and one that has been associated with patient dissatisfaction and inferior outcomes. We sought to provide a comprehensive review of risk factors associated with mid-flexion instability. METHODS: A comprehensive literature search of PUBMED, EMBASE, Google Scholar, and Cochrane Library was performed using keywords "mid flexion," "instability," and "knee arthroplasty" in all possible combinations. All studies published from 2010 to 2020 in English were considered for inclusion. Research design, question studied, and outcomes were recorded for each study. Quantitative and qualitative analysis was performed. RESULTS: Eighteen articles meeting inclusion criteria were identified and reviewed. There were 5 computational studies, 5 cadaveric studies, and 8 clinical studies. There were 14 different risk factors investigated in relation to mid-flexion instability after TKA: 6 implant-related, 6 technique-related, and 2 patient-related factors. Of these risk factors, 5 had contradictory results published to date, resulting in an inconclusive association with mid-flexion instability. The results of this review suggest that the effects of joint line elevation and radius-of-curvature of the femoral component on mid-flexion instability are inconclusive while articular surface conformity and preoperative joint laxity may play a bigger role than previously thought. CONCLUSION: Mid-flexion instability after TKA is a clinical entity distinct from other established forms of instability. There are patient-related, implant-related, and technique-related factors associated with mid-flexion instability. The majority of the evidence on this topic is derived from computational and cadaveric studies, underscoring the need for further clinical studies.

Rapid return to function and stability with dual mobility components cemented into an acetabular reconstructive cage for large osseous defects in the setting of periacetabular metastatic disease.

BACKGROUND AND OBJECTIVES: Large acetabular defects secondary to metastatic disease frequently require extensive acetabular reconstruction. Techniques of acetabular reconstruction have been described, but no consensus for the management of these defects has been reached so far. We present our technique and patient outcomes for acetabular reconstruction by cementing a dual mobility cup into an acetabular cage. METHODS: We reviewed 152 total hip arthroplasties and identified 19 patients with periacetabular metastatic disease and large defects who required acetabular reconstruction utilizing a dual mobility cup cemented into an acetabular reconstructive cage. The following outcomes were evaluated: pain relief, functional improvement, postoperative complications. RESULTS: Mean follow-up was 3 years, with 13 of the 19 patients eligible for 2-year follow-up. Patients reported a significant improvement in both pain and functional outcomes. There were no dislocations or signs of loosening. Two patients developed postoperative infections. One patient required hemipelvectomy 16 months postop due to recurrence of metastatic disease. CONCLUSIONS: Cementing a dual mobility cup into an acetabular cage provides a highly stable and durable option for patients with periacetabular metastatic disease and large defects. Patients are able to return to immediate full weight bearing with significant improvement in both function and pain at 2 years.

Total Joint Arthroplasty and Sleep: The State of the Evidence.

Background: As the number of total hip and knee arthroplasties (TJA) performed increases, there is heightened interest in perioperative optimization to improve outcomes. Sleep is perhaps one of the least understood perioperative factors that affects TJA outcomes. The purpose of this article is to review the current body of knowledge regarding sleep and TJA and the tools available to optimize sleep perioperatively. Methods: A manual search was performed using PubMed for articles with information about sleep in the perioperative period. Articles were selected that examined: sleep and pain in the perioperative period; the effect of surgery on sleep postoperatively; the relationship between sleep and TJA outcomes; risk factors for perioperative sleep disturbance; the effect of anesthesia on sleep; and the efficacy of interventions to optimize sleep perioperatively. Results: Sleep and pain are intimately associated; poor sleep is associated with increased pain sensitivity. Enhanced sleep is associated with improved surgical outcomes, although transient sleep disturbances are normal postoperatively. Risk factors for perioperative sleep disturbance include increasing age, pre-existing sleep disorders, medical comorbidities, and type of anesthesia used. Interventions to improve sleep include optimizing medical comorbidities preoperatively, increasing sleep time perioperatively, appropriating sleep hygiene, using cognitive behavioral therapy, utilizing meditation and mindfulness interventions, and using pharmacologic sleep aids. Conclusions: Sleep is one of many factors that affect TJA. As we better understand the interplay between sleep, risk factors for suboptimal sleep, and interventions that can be used to optimize sleep, we will be able to provide better care and improved outcomes for patients.

Clinical Outcomes After Reverse Total Shoulder Arthroplasty in Patients With Primary Glenohumeral Osteoarthritis Compared With Rotator Cuff Tear Arthropathy: Does Preoperative Diagnosis Make a Difference?

INTRODUCTION: The primary purpose of this study was to evaluate the clinical outcomes of patients who underwent reverse total shoulder arthroplasty performed for primary glenohumeral osteoarthritis (GHOA) with an intact rotator cuff compared with rotator cuff tear arthropathy (CTA). METHODS: This was a retrospective review of prospectively collected data including consecutive patients who underwent primary reverse total shoulder arthroplasty for GHOA or CTA with a minimum of 2-year follow-up. Baseline patient demographics and clinical outcomes including active range of motion, American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numerical Evaluation, and visual analog scale for pain were collected. Univariate and multivariate regression analyses were performed to evaluate the effect of preoperative diagnosis on clinical outcomes. RESULTS: Patients with a preoperative diagnosis of GHOA demonstrated significantly better postoperative active forward elevation (138.6° versus 127.3°; P < 0.01), external rotation (54.2° versus 43.8°; P < 0.01), and change in internal rotation (Δ 2.1 points versus Δ 1.2 points; P < 0.01). Patients with GHOA demonstrated significantly better postoperative ASES (86.8 versus 76.6; P < 0.01), Single Assessment Numerical Evaluation (89.7 versus 78.5; P < 0.01), and visual analog scale scores (0.63 versus 1.2; P < 0.01). Minimal clinically important difference for ASES score was achieved by 97.5% of patients with GHOA compared with 86.7% of patients with CTA (P < 0.01), whereas substantial clinical benefit was achieved by 90.4% of patients with GHOA and 71.7% of patients with CTA (P < 0.01). After a multivariate linear regression analysis, postoperative ASES scores were independently associated with previous ipsilateral shoulder surgery (P = 0.042), preoperative ASES score (P = 0.01), and primary diagnosis of GHOA (P < 0.01). CONCLUSION: RTSA performed in patients with GHOA and an intact rotator cuff is associated with improved functional and clinical outcomes compared with those patients treated for CTA. LEVEL OF EVIDENCE: Level III Therapeutic Study.

A Comparative Analysis of the Quadratus Lumborum Block Versus Femoral Nerve and Fascia Iliaca Blocks in Hip Arthroscopy.

PURPOSE: To evaluate the effect of the single-shot quadratus lumborum (QL) block versus femoral nerve and fascia iliacus (F/FI) blocks performed preoperatively on perioperative opioid requirements, subjective pain scores, and time to discharge. METHODS: Patients who underwent hip arthroscopy for femoroacetabular impingement and had a preoperative nerve block between January 2017 and August 2019 at our institution were identified. Patients were separated into 2 groups: those who either received a preoperative single-shot QL block or a preoperative single-shot F/FI block. All patients received general anesthesia. Intraoperative, postanesthesia care unit (PACU), and total morphine equivalents were analyzed using unpaired t test. Secondary outcome measures including total time in PACU and block-related complications were recorded and analyzed as well. RESULTS: One hundred one patients were retrospectively reviewed. Forty-three patients received preoperative QL blocks, and 58 patients received preoperative F/FI blocks. Demographics and operative characteristics were similar between the 2 groups. Patients receiving a QL block required significantly lower total morphine equivalents (63.1 vs 87.0, P < .001). Patients receiving a QL block also had shorter PACU stays (116 vs 148 minutes, P < .001) and lower subjective pain scores at the time of discharge (3.27 vs 4.98, P < .001) compared with the F/FI block group. There were also significant decreases in the number of intraoperative opioids (42.1 vs 58.4, P < .001) and PACU opioids (20.7 vs 28.7, P = .03) used when analyzed separately. Two patients in the femoral nerve block group had noted a fall postoperatively while the block was in effect. No patients in the QL block group had a block-related complication. CONCLUSIONS: Patients receiving a preoperative QL block for hip arthroscopy demonstrated lower total opioid requirements, shorter PACU stay, and lower pain scores at discharge than patients receiving preoperative F/FI blocks with no reported adverse events. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

Time Matters: Knee Cartilage Defect Expansion and High-Grade Lesion Formation while Awaiting Autologous Chondrocyte Implantation.

OBJECTIVE: The objective of this study was to assess potential risk factors, including time delay until implantation, for knee cartilage defect expansion or new high-grade defect formation between biopsy and Autologous Chondrocyte Implantation (ACI) or Matrix Autologous Chondrocyte Implantation (MACI). STUDY DESIGN: Consecutive knee ACI and MACI cases by a single surgeon (n = 111) were reviewed. The relationship between time between biopsy and staged implantation and (1) progression in primary cartilage defect size and (2) development of a new high-grade (Outerbridge grade ≥3) cartilage defect were determined with adjustment for demographics, body mass index, smoking status, coronal alignment, initial cartilage status, and prior surgery. RESULTS: Average size of the primary defect at time of biopsy was 4.50 cm2. Mean time to chondrocyte implantation was 155 days. Defect expansion increased 0.11 cm2 (standard error = 0.03) per month delay to implantation (P = 0.001). Independent predictors of defect expansion were male sex, smaller initial defect size, and delay to implantation (adjusted mean = 0.15 cm2 expansion per month). A total of 16.2% of patients (n = 18/111) developed a new high-grade defect. Independent predictors of a new secondary defect were Outerbridge grade 2 changes (vs. 0-1) on the surface opposing the index defect and delayed implantation (per month increase, adjusted odds ratio = 1.21, 95% confidence interval: 1.01-1.44; P = 0.036). CONCLUSIONS: Patients undergoing 2-stage cell-based cartilage restoration with either ACI or MACI demonstrated long delays between stages of surgery, placing them at risk for expanding defects and development of new high-grade cartilage defects. Patients who were male, had smaller initial defect size, and longer time between surgeries were at greater risk for defect expansion. LEVEL OF EVIDENCE: III, retrospective comparative study.

The Development of Trigger Thumb in the Contralateral Thumb in Pediatric Patients Presenting Initially With Unilateral Involvement.

Background: Pediatric trigger thumb is a common condition that can occur bilaterally. There have been reports of a metachronous relationship between trigger thumbs developing in both extremities. Surgeons might consider delaying operative treatment of unilateral trigger thumb due to the concern that contralateral symptoms may develop later in childhood, requiring a second procedure and anesthetic event. Methods: We retrospectively reviewed patients diagnosed with pediatric trigger thumb from 2008 to 2016 at a large pediatric hospital. Data collected included age at presentation and onset, laterality, age and timing of onset of contralateral symptoms, time of index procedure and subsequent procedure (if any), severity of symptoms, previous treatments, range of motion, and birth history. Results: There were 198 patients with pediatric trigger thumb, with 55 patients (28%) presenting with or developing bilateral involvement. Fifty patients (25%) had bilateral involvement upon initial presentation. Five patients (3%) were subsequently diagnosed with contralateral trigger thumb after initial presentation of unilateral trigger thumb. Average time to contralateral trigger thumb development was 12 months after presentation in unilateral patients. Most patients presented with locked flexion contracture with palpable Notta's nodule. Of the 5 patients who developed contralateral trigger thumbs, three required a second surgery after the index procedure. Conclusions: The vast majority of patients with bilateral trigger thumbs had bilateral involvement upon initial presentation to the pediatric hand clinic. Given the rarity of bilateral symptoms after initial unilateral presentation, we do not recommend delayed surgical intervention for patients with unilateral disease in children over 3 years of age.

Variability in Parenteral Nutrition Use in US Children's Hospitals.

BACKGROUND: The variability of parenteral nutrition (PN) use for pediatric inpatients is currently unknown. In this study, we aim to determine the variability in PN use in US children's hospitals and the association of PN initiation with inpatient PN use. METHODS: We performed a retrospective cohort study of children who received PN during an inpatient encounter in US children's hospitals. Hospitals were divided into tertiles based on their rates of PN use: low (<36.9 of 1000 encounters), medium (36.9-51.8 of 1000 encounters), and high (>51.8 of 1000 encounters). Multivariable regression models were developed to assess the associations between hospital PN use and time to PN initiation, PN duration, and encounter length of stay after adjustment for salient patient characteristics. RESULTS: The cohort included 82,142 patients receiving PN, and rates of hospital PN use ranged from 5.9 to 76.7 patients receiving PN per 1000 inpatient encounters. After multivariable adjustment, patients treated at high-use hospitals had a significantly shorter time to initiation of PN compared with low-use hospitals (incident rate ratio [95% CI]: 0.78 [0.69-0.89]; P < .001). There was no significant association between low- and medium- or high-use hospitals regarding PN duration or hospital length of stay. CONCLUSION: Large variation in PN use exists among US children's hospitals. High-use hospitals are more likely to start PN earlier but do not have longer PN duration or encounter length of stay. This variability makes PN use an ideal target for hospital quality improvement efforts to improve adherence to PN evidence-based guidelines.

Surgical Technique for Superior Capsule Reconstruction With 6-mm Acellular Dermal Allograft and Knotless Glenoid Anchors.

Superior capsule reconstruction (SCR) creates a humeral head depressor in the setting of a massive, irreparable rotator cuff tear. Recently, a 6-mm-thick acellular dermal allograft (ACD) has been shown to be noninferior to the standard fascia lata autograft in recreating native shoulder biomechanics. This paper outlines a reproducible means by which to perform an arthroscopic SCR using a 6-mm ACD. A standard diagnostic arthroscopy first assesses the integrity of the subscapularis and infraspinatus tendons. The glenoid anchors are then placed. Accessory anterior and posterolateral portals are made as well as a lateral portal by which to shuttle the graft. Suture management is paramount. Ideally allograft preparation occurs on the back table simultaneously to maintain efficiency. Suture passage through premade holes in the graft, and when the sutures have passed through and been tensioned, the graft is shuttled into place and tied down with medial and lateral row anchors in SpeedBridge fashion. The thickness of ACD has been shown to influence the ability of the reconstructed superior capsule to perform its role as a humeral head depressor. This technique describes the use of a 6-mm-thick ACD to perform an arthroscopic SCR that minimizes both donor-site morbidity and operative time.

Early Postoperative Improvement in Sleep and Pain After Carpal Tunnel Release.

Background: Carpal tunnel syndrome (CTS) is the most common compressive neuropathy of the upper extremity. We sought to assess the subjective improvement in preoperative symptoms related to CTS, particularly those affecting sleep, and describe opioid consumption postoperatively. Methods: All patients undergoing primary carpal tunnel release (CTR) for electromyographically proven CTS were studied prospectively. All procedures were performed by hand surgery fellowship-trained adult orthopedic and plastic surgeons in the outpatient setting. Patients underwent either endoscopic or open CTR from June 2017 to December 2017. Outcomes assessed were pre- and postoperative Quick Disabilities of Arm, Shoulder and Hand (QuickDASH), visual analog scale (VAS), and Pittsburgh Sleep Quality Index (PSQI) scores as well as postoperative pain control. Results: Sixty-one patients were enrolled. At 2 weeks, all showed significant (P < .05) improvement in QuickDASH scores. At 6 weeks, 40 patients were available for follow-up. When compared with preoperative scores, QuickDASH (51 vs 24.5; P < .05), VAS (6.7 vs 2.9; P < .05), and PSQI (10.4 vs 6.4; P < .05) scores continued to improve when compared with preoperative scores. At 2-week follow-up, 39 patients responded to the question, "How soon after your carpal tunnel surgery did you notice an improvement in your sleep?" Seventeen patients (43.6%) reported they had improvement in sleep within 24 hours, 12 patients (30.8%) reported improvement between 2 and 3 days postoperatively, 8 patients (20.5%) reported improvement between 4 and 5 days postoperatively, and 2 patients (5.1%) reported improvement between 6 and 7 days postoperatively. Conclusions: The present study demonstrates rapid and sustained improvement in sleep quality and function following CTR.

Determination of Marital Status of Patients from Structured and Unstructured Electronic Healthcare Data.

Social Determinants of Health, including marital status, are becoming increasingly identified as key drivers of health care utilization. This paper describes a robust method to determine the marital status of patients using structured and unstructured electronic healthcare data from a single academic institution in the United States. We developed and validated a natural language processing pipeline (NLP) for the ascertainment of marital status from clinical notes and compared the performance against two baseline methods: a machine learning n-gram model, and structured data obtained from the electronic health record. Overall our NLP engine had excellent performance on both document-level (F1 0.97) and patient-level (F1 0.95) classification. The NLP Engine had superior performance compared with a baseline machine learning n-gram model. We also observed a good correlation between the marital status obtained from our NLP engine and the baseline structured electronic healthcare data (κ 0.6).

Management strategies for osteochondritis dissecans of the knee in the skeletally immature athlete.

SYNOPSIS: Osteochondritis dissecans (OCD) is a disorder resulting in focal breakdown of the subchondral bone, with potential disruption of the overlying articular cartilage. The femoral condyles of the knee are the most common locations for OCD, and the incidence of OCD appears to be increasing among active children. Juvenile OCD (JOCD) can be distinguished from adult OCD by the presence of open growth plates. Due to a lack of evidence on its early diagnosis, optimal treatment, and long-term course of healing, JOCD presents a unique challenge for the health care team. Approximately 50% to 67% of stable JOCD lesions heal successfully with nonoperative treatment. For unstable lesions and stable lesions that fail nonoperative treatment, a variety of surgical interventions can be utilized to stimulate bony healing and address articular cartilage lesions. It is recommended that rehabilitation of JOCD be tailored to the individual patient, based on the stage and radiographic status of the lesion and the mode of surgery employed when surgically addressed. Although there is a growing body of literature on this condition, the etiology and optimal methods for treatment, rehabilitation, and evaluating outcomes remain inconclusive due to a lack of quality evidence. LEVEL OF EVIDENCE: Therapy, level 5.

Differences in preferences of entrees by elderly congregate meal participants according to age, gender, ethnicity and education and a factor analysis approach to group entrée preferences.

Congregate meal participants (n = 381), ages 60-100, provided preference ratings of 43 entrees utilizing a modified Food Rating Scale (FACT). Differences in preferences of entrees associated with age, gender, ethnicity and educational level were analyzed using X2 analysis. Factor analysis was used to group entrees which were associated according to preferences. Both males and females agreed with the top five preferred entrees. For other entrees, females had a higher acceptance level. Both age groups preferred the same top five entrees; for other entrees, the younger group was more accepting of these. Few differences were noted among the various ethnic groups (91% white and 7% African-American). Education level of respondents had a varying association with entree preference, depending upon the specific entree.