Radiology Reports Do Not Accurately Portray the Severity of Cervical Neural Foraminal Stenosis

STUDY DESIGN

Retrospective study.

OBJECTIVE

(1) To compare cervical magnetic resonance imaging (MRI) radiology reports to a validated grading system for cervical foraminal stenosis (FS) and (2) to evaluate whether the severity of cervical neural FS on MRI correlates to motor weakness or patient-reported outcomes.

BACKGROUND

Radiology reports of cervical spine MRI are often reviewed to assess the degree of neural FS. However, research looking at the association between these reports and objective MRI findings, as well as clinical symptoms, is lacking.

PATIENTS AND METHODS

We retrospectively identified all adult patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion at a single academic center for an indication of cervical radiculopathy. Preoperative MRI was assessed for neural FS severity using the grading system described by Kim and colleagues for each level of fusion, as well as adjacent levels. Neural FS severity was recorded from diagnostic radiologist MRI reports. Motor weakness was defined as an examination grade <4/5 on the final preoperative encounter. Regression analysis was conducted to evaluate whether the degree of FS by either classification was related to patient-reported outcome measure severity.

RESULTS

A total of 283 patients were included in the study, and 998 total levels were assessed. There were significant differences between the MRI grading system and the assessment by radio-logists (P< 0.001). In levels with moderate stenosis, 28.9% were classified as having no stenosis by radiology. In levels with severe stenosis, 29.7% were classified as having mild-moderate stenosis or less. Motor weakness was found similarly often in levels of moderate or severe stenosis (6.9% and 9.2%, respectively). On regression analysis, no associations were found between baseline patient-reported outcome measures and stenosis severity assessed by radiologists or MRI grading systems.

CONCLUSION

Radiology reports on the severity of cervical neural FS are not consistent with a validated MRI grading system. These radiology reports underestimated the severity of neural foraminal compression and may be inappropriate when used for clinical decision-making.

LEVEL OF EVIDENCE

Level III.

Does operative level impact dysphagia severity following anterior cervical discectomy and fusion? a multicenter prospective analysis

STUDY DESIGN

Prospective multi-center cohort study.

OBJECTIVE

To explore the association between operative level and postoperative dysphagia after anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Dysphagia is common following ACDF and has several risk factors including soft tissue edema. The degree of prevertebral soft tissue edema varies based upon the operative cervical level. However, the operative level has not been evaluated as a source of postoperative dysphagia.

METHODS

Adult patients undergoing elective ACDF were prospectively enrolled at three academic centers. Dysphagia was assessed using the Bazaz questionnaire, Dysphagia Short Questionnaire (DSQ), and Eating Assessment Tool-10 (EAT-10) preoperatively and at 2, 6, 12, and 24-weeks postoperatively. Patients were grouped based on inclusion of specific surgical levels in the fusion construct. Multivariable regression analyses were performed evaluating the independent effects of number of surgical levels and inclusion of each particular level on dysphagia symptoms.

RESULTS

A total of 130 patients were included. Overall, 24 (18.5%) patients had persistent postoperative dysphagia at 24 weeks and were older, female, and less likely to be drink alcohol. There was no difference in operative duration or dexamethasone administration. Patients with persistent dysphagia were significantly more likely to have C4-C5 included in the fusion construct (62.5% vs. 34.9%, P=0.024) but there were no differences based on inclusion of other levels. On multivariable regression, inclusion of C3-C4 or C6-C7 were associated with more severe EAT-10 (β:9.56, P=0.016 and β:8.15, P=0.040) and DSQ (β:4.44, P=0.023 and (β:4.27, P=0.030) at 6 weeks. At 12-weeks, C3-C4 fusion was also independently associated with more severe dysphagia (EAT-10 β:4.74, P=0.024).

CONCLUSION

The location of prevertebral soft tissue swelling may impact the duration and severity of patient-reported dysphagia outcomes at up to 24 weeks postoperatively. In particular, inclusion of C3-C4 and C4-C5 into the fusion may be associated with dysphagia severity.

Values derived from patient reported outcomes in spine surgery: a systematic review of the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptom state

PURPOSE

While patient reported outcome measures (PROMs) define value in spine surgery, several values such as minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) help guide the interpretation of PROMs and identify thresholds of clinical significance. Significant variation exists in reported values and their calculation, so the primary objective of this study was to systematically review the spine surgery literature for metrics of clinical significance derived from PROMs.

METHODS

We conducted a query of PubMed/MEDLINE and Scopus databases from inception to January 1, 2023, for studies that derived quantitative metrics (e.g., SCB, MCID, PASS) from PROMs in the setting of spine surgery with minimum 1-year follow-up. Details regarding the specific PROMs were collected including which PROM was measured, whether anchor- or distribution-based methods were utilized, the specific calculations, and the recommended value for a given PROM based on all evaluated calculations.

RESULTS

Thirty-seven studies of 21,780 patients were included. The most commonly evaluated PROM-derived value was the MCID (n = 28), followed by PASS (n = 6) and SCB (n = 4). Twenty-one studies only utilized anchor-based calculations, 15 utilized both anchor-based and distribution-based methods, and one only utilized distribution-based calculations. The most commonly evaluated legacy PROMs were the Oswestry Disability Index (ODI) (N = 11, MCID range 4-20) and visual analog scale back pain (N = 5, MCID range 0.5-4.6). All 10 studies that derived SCB or PASS utilized the receiver operating characteristic methods. Among the six studies deriving a PASS value, four only evaluated ODI, identifying PASS ranging from 5 to 22.

CONCLUSION

While calculated measures of clinical significance such as MCID, PASS, and SCB exist, significant heterogeneity exists in the current literature. Current shortcomings include a wide variability of reported value thresholds across the literature, and limited applicability to more heterogenous patient populations than the targeted cohorts included in published investigations. Continued investigations that apply these methods to heterogenous, large-scale populations can help increase generalizability and validity of these measures.

LEVEL OF EVIDENCE

III.

The severity of preoperative anemia escalates risk of poor short-term outcomes after lumbar spine fusion

OBJECTIVE

To evaluate how preoperative anemia severity affects 90-day outcomes of spinal fusion surgery.

METHODS

A retrospective cohort study was conducted on adult lumbar fusion patients at a tertiary medical center. Patients were classified by World Health Organization anemia severity definitions for comparisons. Multivariate regression models were created to control for confounding variables, for all primary outcomes of transfusion requirements, non-home discharge, readmissions, complications, and length of stay.

RESULTS

A total of 2582 patients were included: 2.7% with moderate-severe anemia, 11.0% with mild anemia, and 86.3% without anemia. Moderate-severe patients had the longest hospital stay (5.03 days vs 4.14 and 3.59 days, p < 0.001) and highest risk of transfusion (52.2% vs 13.0% vs 2.69%, p < 0.001), non-home discharge (39.1% vs 27.8% vs 15.4%, p < 0.001), readmission (7.25% vs 5.99% vs 3.36%, p = 0.023), and complications (13.0% vs 9.51% vs 6.20%, p = 0.012). On multivariable logistic regression, both patients with mild and moderate-severe anemia had an increased risk of transfusion (OR: 37.3, p < 0.001; OR: 5.25, p < 0.001, respectively) and non-home discharge (OR: 2.00, p = 0.021; OR: 1.71, p = 0.001, respectively) compared to patients without anemia. Anemia severity was not independently associated with complications or 90-day readmission. On multivariable linear regression, mild anemia (β: 0.37, p = 0.001) and moderate-severe anemia (β: 1.07, p < 0.001) were independently associated with length of hospital stay.

CONCLUSION

Patients with moderate-severe preoperative anemia are at increased risk for longer length of stay, transfusions, and non-home discharge. Improved optimization of preoperative anemia may significantly reduce healthcare utilization, and surgeons should consider these risks in preoperative planning.

LEVEL OF EVIDENCE

III.

Does decompression adjacent to arthrodesis in the lumbar spine predispose patients to adjacent segment degeneration and disease: A retrospective analysis

Background

The treatment for multi-level spinal stenosis in the setting of single-level instability is a common operative scenario for surgeons who treat degenerative lumbar spine pathology. However, there is conflicting evidence regarding the inclusion of adjacent "stable" levels in the arthrodesis construct because of the potential for iatrogenic instability placed on those segments with decompressive laminectomy alone. This study aims to determine whether decompression adjacent to arthrodesis in the lumbar spine is a risk factor for adjacent segment disease (AS Disease).

Methods

A retrospective analysis identified consecutive patients over a three-year period who underwent single-level posterolateral lumbar fusion (PLF) in the setting of single or multi-level spinal stenosis. Patients were required to have a minimum of two-year follow-up. AS Disease was defined as the development of new radicular symptoms referable to a motion segment adjacent to the lumbar arthrodesis construct. The incidence of AS Disease and reoperation rates were compared between cohorts.

Results

133 patients met the inclusion criteria with an average follow-up of 54 months. Fifty-four patients had a PLF with adjacent segment decompression, and 79 underwent a single-segment decompression and PLF. 24.1% (13/54) of patients who had a PLF with adjacent level decompression developed AS Disease resulting in a 5.5% (3/54) reoperation rate. 15.2% (12/79) of patients who did not receive an adjacent level decompression developed AS Disease resulting in a reoperation rate of 7.5% (6/79). There was neither a significantly higher rate of AS Disease (p = 0.26) nor reoperation (p = 0.74) between the cohorts.

Conclusions

Decompression adjacent to single-level PLF was not associated with an increased rate of AS Disease relative to single-level decompression and PLF.

Outcomes After Surgically Managed Oblique Extra-Articular Proximal Phalanx Fractures: A Comparison of Closed-Reduction Percutaneous Pinning and Open-Reduction Internal Fixation With Lag Screws

BACKGROUND

Long oblique extra-articular proximal phalanx fractures are common orthopedic injuries. When unstable and without substantial comminution, treatment options include closed-reduction percutaneous pinning (CRPP) and open-reduction internal fixation using lag screws (ORIF-screws). The aims of this study are primarily to compare the functional outcomes and complication rates between these techniques and secondarily to assess potential factors affecting outcomes after surgery.

METHODS

All patients with long oblique extra-articular proximal phalanx fractures treated surgically within a single orthopedic institution from 2010 to 2017 were identified. Outcome measures and complications were assessed at the final follow-up.

RESULTS

Sixty patients were included in the study with a mean time to the final follow-up of 41 weeks (range: 12-164 weeks). Thirty-four patients (57%) were treated with CRPP and 26 patients (43%) with ORIF-screws. The mean Disabilities of the Arm, Shoulder, and Hand score across both fixation types was 8 (range: 0-43) and did not differ significantly between the 2 groups. Mean proximal interphalangeal extension at the final follow-up was 9° short of full extension after CRPP and 13° short of full extension after ORIF-screws. The rates of flexion contracture and extensor lag were 15% and 41% in the CRPP group compared with 12% and 68% in the ORIF-screws group. Reoperation rates and complication rates did not differ significantly between fixation strategies.

CONCLUSIONS

Acceptable outcomes can be achieved after surgical fixation of long oblique extra-articular proximal phalanx fractures using both CRPP and ORIF-screws. Extensor lag may be more common after ORIF-screws.

Surgical Treatment of Shoulder Infection Following Rotator Cuff Repair

Background

Deep infection after rotator cuff repair (RCR) can cause significant morbidity and healthcare burden. Outcomes of surgical treatment of infection following RCR are limited. This study aimed to assess the clinical course and outcomes related to surgical management of deep infection following RCR.

Methods

Patients treated with debridement for infection after RCR at a single institution were included. Postoperative deep infection included the following criteria: persistent drainage more than five days from index surgery, development of a sinus tract to the joint, ≥ 2 positive cultures at the time of revision surgery with the same bacteria, or presence of purulence. Functional outcomes (ASES, SANE, SF-12) were assessed at a minimum of 1-year post-debridement.

Results

Twenty-three patients were included and analyzed at mean six years post-debridement. All were free of infection at the final follow-up. The average age was 55 years; fifteen (65.2%) had infection after primary RCR and eight (34.8%) after revision RCR. Twelve (52.2%) patients required a repeat debridement prior to eradicating infection for an average of 1.9 surgeries before clearance of infection. Statistically significant predictors of need for a repeat debridement included initial open RCR (P = .02), open debridement (P = .002) and infection requiring IV antibiotics (P = .014). Postoperative ASES, SANE, SF-12M, SF-12P, and satisfaction scores were 71.7±25.7, 67.0±28.1, 55.5±6.5, 38.4±14.3 and 3.7±1.3, respectively.

Conclusion

Deep infection after RCR can be treated with open or arthroscopic debridement. However, more than 50% of patients may require multiple debridements. Final functional results after infection control following RCR are satisfactory. However, chronic infection predicts worse functional outcomes.

Reliability of Routine Radiographs for Conservatively Treated Metacarpal Shaft and Neck Fractures

Background

To investigate the reliability of orthopedic hand surgeons to evaluate radiographic healing in initial and follow-up radiographs of the conservatively treated metacarpal shaft and neck fractures. The rationale for this study was to reduce the rate of unnecessary, routine radiographs when treating metacarpal fractures.

Methods

Forty sets of digital x-rays, twenty at the initial visit and twenty at the 4-week follow-up, were randomly selected and reviewed. Three hand surgeons evaluated the x-rays for (1) fracture location, (2) radiograph timing, (3) healing status, (4) percentage healed, (5) angulation, and (6) confidence in healing status. Observers reviewed studies in random order and evaluated the same set of radiographs one month after the initial review. Intra- and interobserver agreements were analyzed using Fleiss' kappa (κ) for all parameters and all possible observer pairings.

Results

Interobserver and intraobserver reliability was highest when evaluating fracture location and lowest when assessing the percentage healed. The interobserver reliability was fair for radiograph timing and healing status and fair-to-moderate for angulation. The intraobserver reliability was moderate for radiograph timing and healing status and moderate-to-substantial for angulation. Observers correctly differentiated initial vs. follow-up images 62% of the time and reported to feel somewhat certain in their evaluation of healing status.

Conclusion

When evaluating initial and 4-week follow-up radiographs, hand surgeons were somewhat confident in their assessment of healing but had less than substantial intra- and interobserver reliability following radiographic evaluation. Due to their poor reproducibility, routine radiographs may be unnecessary when evaluating conservatively treated metacarpal fractures. Further studies and guidelines that identify clear indications for the use of routine imaging in metacarpal fracture care are warranted.

Unplanned Office Visits Following Outpatient Hand Surgery

BACKGROUND

Returning to the office for an unplanned visit postoperatively can be burdensome to both the patient and provider. The purpose of this study was to quantify the rate of unplanned office visits after common soft tissue hand surgeries and assess the reasons for these unplanned visits.

METHODS

Patients who underwent common soft tissue hand surgeries over a 6-month time period were queried from an electronic medical record database. Manual chart review was performed to record patient demographics, unplanned visits within 3 months postoperatively, and specific reasons for unplanned visits. A total of 1648 postoperative follow-up visits in 1224 patients were included in analysis.

RESULTS

Within 3 months of surgery, 6.3% (103/1648) of postoperative visits were found to be unplanned. There was no difference in the rate of unplanned visits among the included surgeries (P = .46). The most common reasons for an unplanned office visit overall were wound problems (34%), pain (23.3%), and stiffness (17.5%). The trigger finger release group had significantly more patients return to the office for stiffness (P = .01), the De Quervain release group had significantly more patients return for pain (P = .02), and the carpal tunnel release group had significantly more patients return for persistent symptoms (P < .05).

CONCLUSIONS

Unplanned office visits represented about 1 of 16 postoperative visits. Orthopedic surgeons should be aware of the most common reasons for these visits and be prepared to address these problems promptly. Preoperative patient education on these potential problems may help decrease the frequency of unplanned follow-up visits.

Outcomes of Type I Open Distal Radius Fractures: A Comparison of Delayed and Urgent Open Reduction Internal Fixation

BACKGROUND

Type I open distal radius fractures treated with open reduction internal fixation (ORIF) have demonstrated minimal risk of infection. For this reason, they may not require urgent surgical treatment. The purpose of this study was to evaluate the outcomes of patients with type I open distal radius fractures treated with delayed ORIF compared with urgent ORIF.

METHODS

We identified all Gustilo-Anderson type I open distal radius fractures that had undergone ORIF using volar plating over a 5-year period. Patients were stratified into those treated urgently within 24 hours and those scheduled for delayed surgery. Outcomes including functional scores, complications, reoperations, and radiographic measures were compared.

RESULTS

Twenty-four patients (17 treated urgently and 7 treated delayed) had open type I distal radius fractures. All patients were started on empiric antibiotics at initial presentation-patients in the delayed treatment group were prescribed oral antibiotics, whereas those admitted for urgent treatment received intravenous antibiotics. There were no infections in either group and a single reoperation in each group. The mean postoperative Quick Disabilities of the Arm, Shoulder, and Hand score was 29 (range = 0-77) and did not differ significantly between delayed (mean = 19) and urgent (mean = 38) treatment. Rate of complications and radiographic measures did not differ significantly between the groups.

CONCLUSIONS

Type I open distal radius fractures appear amenable to delayed outpatient ORIF provided that the wound is clean at the time of initial presentation and that antibiotics are initiated appropriately. Further prospective studies comparing delayed and urgent treatment strategies are warranted.

Radiographic Outcomes of Casting Versus Splinting for Conservatively Treated Metacarpal Fractures

Introduction

While many have studied alternate forms of casting for conservative treatment of metacarpal fracture, few have compared casting and splinting. This study aims to compare radiographic alignment in metacarpal shaft and neck fractures immobilized with splints to those treated with casts.

Methods

A retrospective review was conducted to identify all metacarpal fractures treated by a single orthopedic hand surgeon from 2016-2020. Patients with metacarpal shaft or neck fractures treated nonoperatively, immobilized with either a cast or a splint, and with a minimum of one follow-up visit were included. Degrees of radial/ulnar angulation, dorsal/volar angulation, and changes in angulation were measured. Mean angulation measurements and changes in angulation were compared across groups using Mann-Whitney U tests.

Results

A total of 61 patients, 45 treated with casts and 16 with splints, met our inclusion criteria. The average immobilization time was 28 days for both groups (p=0.958). Change in radial/ulnar angulation was similar between the two groups (splint = -3⁰, cast = -3⁰, p=0.79). No significant differences were found when comparing changes in dorsal/volar angulation across groups (splint = -0.3⁰, cast = -0.1⁰, p=0.57). No complications were reported in either group.

Conclusions

Our results suggest that metacarpal shaft and neck fractures treated with splints can maintain fracture reduction and angulation comparable to casting. Splints offer additional benefits of reduced costs with improved patient hygiene and satisfaction. Further studies on the utility and cost-effectiveness of splints for treating metacarpal fractures are warranted.

A Rare Presentation of Extensor Pollicis Longus Tendon Rupture After Nondisplaced Scaphoid Fracture

Extensor pollicis longus tendon rupture is a reported complication after nondisplaced distal radius fractures. These are thought to occur secondary to mechanical irritation or compromised blood supply. We present a case of extensor pollicis longus rupture after a healed nondisplaced scaphoid fracture, which may have involved a similar attritional process. We are unaware of any prior reports of extensor pollicis longus rupture after this type of injury.

Does Surgery Improve Healing After Isolated Diaphyseal Ulna Fractures?

PURPOSE

Isolated diaphyseal ulna fractures can be treated nonsurgically or with open reduction and internal fixation (ORIF). It is unclear whether ORIF provides quicker and/or more predictable healing. The purpose of this study was to compare the healing characteristics of isolated diaphyseal ulna fractures after surgical and nonsurgical treatment.

METHODS

All patients treated for an isolated diaphyseal (distal- or middle-third) ulna fracture between 2010 and 2018, with a minimum of 3 months of follow-up, were identified. Electronic medical records were reviewed to record patient demographics, assess the treatments used, and compare outcomes. We determined healing and nonunion rates, complications, reoperations, and final radiographic fracture alignment.

RESULTS

Ninety-five patients were included with a median follow-up of 20 weeks. Of these, 56 patients were treated nonsurgically and 39 patients were treated with ORIF. At the time of the final follow-up, 51 of the 56 (91.1%) nonsurgically treated fractures had healed and 38 of the 39 (97.4%) surgically managed fractures had healed. There were 5 nonunions after nonsurgical treatment (8.9%) and 1 nonunion after ORIF (2.6%). Eleven patients (19.6%) treated nonsurgically required conversion to ORIF, whereas 4 patients (10.3%) treated with ORIF required reoperation. Middle-third fractures treated nonsurgically had a higher rate of nonunion (30.8%) compared with distal-third fractures treated nonsurgically (2.3%).

CONCLUSIONS

The healing characteristics of isolated ulnar shaft fractures do not appear to differ substantially between surgical and nonsurgical treatment. However, nearly 20% of the patients treated nonsurgically may require eventual ORIF. Distal-third fractures may be at a higher risk of conversion to ORIF, and middle-third fractures may be at a higher risk of nonunion.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Wound Dehiscence Following Cubital Tunnel Surgery

PURPOSE

Cubital tunnel syndrome is the second most common upper-extremity compressive neuropathy, and persistent symptoms can necessitate operative treatment. Surgical options include simple decompression and ulnar nerve transposition. The cause of wound dehiscence after surgery is not well known, and the factors leading to the development of these complications have not been previously described.

METHODS

Patients undergoing ulnar nerve surgery from January 1, 2016, to December 31, 2019, were retrospectively evaluated for the development of wound dehiscence within 3 months of surgery. There were 295 patients identified who underwent transposition and 1,106 patients who underwent simple decompression. Patient demographics and past medical history were collected to evaluate the risk factors for the development of wound dehiscence.

RESULTS

The overall rate of wound dehiscence following surgery was 2.5%. In the simple decompression group, the rate of wound dehiscence was 2.7% (30/1,106), which occurred a mean of 21 days (range, 2-57 days) following surgery. In the transposition group, the rate of wound dehiscence was 1.7% (5/295), which occurred a mean of 20 days (range, 12-32 days) following surgery. The difference in rates of dehiscence between the decompression and transposition groups was not significant. Five patients in the simple decompression group and 1 patient in the transposition group required a secondary surgery for closure of the wound. Age, body mass index, smoking status, and medical comorbidities were not found to contribute to the development of wound dehiscence.

CONCLUSIONS

Wound dehiscence can occur following both simple decompression and transposition, even after postoperative evaluation demonstrates a healed wound. Surgeons should be aware of this possibility and specifically counsel patients about remaining cautious with, and protective of, their wound for several weeks after surgery. Dehiscence may be related to suboptimal vascularity in the soft tissue envelope in the posteromedial elbow. When it occurs, dehiscence can generally be treated by allowing healing by secondary intention.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Do Postoperative Telehealth Visits Require a High Rate of Redundant In-Person Evaluation After Upper Extremity Surgery?

Background

Telehealth platforms may save resources for patients and providers, but the precise impact of their incorporation during the postoperative period is not well understood. The goal of this study is to determine whether telehealth incorporation in the postoperative period leads to an overall increase in healthcare utilization after upper extremity surgery.

Methodology

Patients seen for a postoperative telehealth visit after upper extremity surgery were randomly selected and retrospectively enrolled. Complications and the total number of postoperative visits before clinical discharge were recorded and compared to controls matched by surgery type and surgeon.

Results

A total of 56 patients were seen for 60 telehealth visits. The most common surgical procedures were distal radius open-reduction internal fixation (n = 8), open carpal tunnel release (n = 8), and endoscopic carpal tunnel release (n = 6). One telehealth visit (1.7%) required conversion to in-person evaluation due to suspected superficial infection necessitating in-person physical examination. The average number of postoperative visits prior to clinical discharge was 2.6 in the telehealth group compared to 2.7 in matched controls (p = 0.886). Complication rates were similar between groups.

Conclusions

The rate of necessary in-person evaluation after postoperative telehealth visits was less than 2%. The incorporation of telehealth visits did not appear to increase healthcare utilization after upper extremity surgery. Accordingly, the postoperative period is likely an ideal application for safe and effective telehealth implementation.

Functional Outcomes of Flexor Tendon Repair in the Fingers: A Comparison of Wide-Awake Local Anesthesia No Tourniquet Versus Traditional Anesthesia

BACKGROUND

Flexor tendon lacerations in the fingers are challenging injuries that can be repaired using the wide-awake local anesthesia no tourniquet (WALANT) technique or under traditional anesthesia (TA). The purpose of our study was to compare the functional outcomes and complication rates of patients undergoing flexor tendon repair under WALANT versus TA.

METHODS

All patients who underwent a primary flexor tendon repair in zone I and II without tendon graft for closed avulsions or open lacerations between 2015 and 2019 were identified. Electronic medical records were reviewed to record and compare patient demographics, range of motion, functional outcomes, complications, and reoperations.

RESULTS

Sixty-five zone I (N = 21) or II (N = 44) flexor tendon repairs were included in the final analysis: 23 WALANT and 42 TA. There were no statistical differences in mean age, length of follow-up, proportion of injured digits, or zone of injury between the groups. The final Quick Disabilities of the Arm, Shoulder, and Hand score in the WALANT group was 17.2 (SD: 14.4) versus 23.3 (SD: 18.5) in the TA group. There were no statistical differences between the groups with any final range of motion (ROM) parameters, grip strength, or Visual Analog Scale pain scores at the final follow-up. The WALANT group was found to have a slightly higher reoperation rate (26.1% vs 7.1%; P = .034) than the TA group.

CONCLUSIONS

This study represents one of the first clinical studies reporting outcomes of flexor tendon repairs performed under WALANT. Overall, we found no difference in rupture rates, ROM, and functional outcomes following zone I and II flexor tendon repairs when performed under WALANT versus TA.

Evaluating Patient Interest in Orthopedic Telehealth Services Beyond the COVID-19 Pandemic

Background

Patient interest and demand may have an impact on dictating the scope of orthopedic telehealth utilization beyond the coronavirus disease 2019 (COVID-19) pandemic. The purpose of this study was to assess whether current interest in orthopedic telehealth services is higher than pre-pandemic levels. Specific trends in interest, subspecialty differences, and regional differences were secondarily assessed.

Methodology

A Google Trends search was performed to assess orthopedic telehealth search interest over the last five years using the terms “Orthopedic surgeon/doctor/injury/pain + Telehealth” as well as subspecialty-specific terms. The results were formulated into combined search interest values (CSIVs), with a maximum possible value of 400, and compared between the pre-pandemic period, pre-vaccine period during the pandemic, and post-vaccine period.

Results

The pre-pandemic period mean CSIV was 40.3 (SD = 6.3), compared to 134.7 (SD = 72.1) during the pre-vaccine period, and 96.3 (SD = 4.4) during the post-vaccine period (p < 0.001). There was a positive correlation between CSIV and time (increasing weeks) during the pre-pandemic period (r_s = .77, p < 0.001) and no significant correlation between CSIV and time during the post-vaccine period (r_s = -.12, p = 0.610). Using the slope of the interest line during the post-vaccine period (y = 97.06 - 0.08x) it would take an additional 13.3 years beyond the study period to reach the mean pre-pandemic CSIV level of 40.3. Hand surgery was the subspecialty with the highest mean CSIV over the study period and general search interest was highest in Northeastern and Southeastern states during the post-vaccine period.

Conclusions

Orthopedic telehealth interest was growing before the COVID-19 pandemic and remains significantly elevated beyond pre-pandemic levels despite the reopening of clinical offices and vaccine availability across the country. It appears that a subset of patients will continue to seek telehealth services beyond the pandemic.

Deep Infection after Distal Radius Open-reduction Internal Fixation: A Case Series

Background

Given its low incidence, the management of deep infection following distal radius open-reduction internal fixation (ORIF) has not been well reported. In an effort to expand our current understanding, the purpose of this case series is to present the treatment strategies and functional outcomes associated with deep infection after distal radius ORIF.

Methods

All patients with deep infections after distal radius ORIF over a ten-year period were identified and their treatment courses asessed.

Results

The cohort consisted of three women and one man with an average age of 55.5 ± 17.6 years. Mean time from infection presentation to irrigation and debridement (I&D) with removal of hardware (ROH) was 16 days (Range: 3 - 44 days). The identified bacterial species in all cases was Staphylococcus aureus (MRSA = 2, MSSA = 2). Three patients were treated with intravenous antibiotics, while one patient was treated with oral antibiotics. Mean time from infection presentation to final clinical follow-up was 11 months (Range: 3 - 20 months). Two patients required repeat I&D. A clinical determination of successful infection eradication was made in all cases.

Conclusion

The reported rate of deep infection after distal radius ORIF is less than 1%. There is no well-defined treatment algorithm for patients with deep infection after distal radius ORIF. However, removal of hardware and post-operative oral or intravenous antibiotic therapy appears effective, and is consistent with the standard practices of treating infection after other orthopaedic surgeries.

The Surgical Treatment of Deep Infection in the Native Shoulder Joint

Background

The overall clinical picture surrounding native shoulder infections, and, in particular, the associated long-term functional outcomes of treatment are presently underreported. The purpose of this study is to examine the demographics, diagnostic and treatment strategies, and functional outcomes of isolated shoulder joint sepsis treated with surgical irrigation and debridement (I&D).

Methods

All patients treated with I&D for native shoulder sepsis between 2007 - 2017 were identified. Those without a minimum of one-year follow-up were excluded. Functional outcomes scores, reoperations, and predictors of poor outcome were evaluated.

Results

Twenty-three patients were included in the final study population. Mean age-adjusted CCI score was 4.1 (SD = 3.4, Range = 0 - 10). Twelve patients (52.2%) were treated with open I&D, while 11 patients (47.8%) were treated arthroscopically. Nine patients (39.1%) required multiple I&Ds (mean total number of I&Ds = 1.7, SD = 1.0, Range: 1 - 4). Five patients (21.7%) had at least one documented reinfection after their initial hospitalization, with the initial recurrence of infection occurring 2 - 15 months after the index procedure. Mean ASES score at final follow-up was 55.3 (SD = 26.7, Range: 5.8 - 98.3) and mean SANE score was 53.3 (SD = 30.6, Range: 0 - 100). Stepwise multiple linear regression modeling identified intravenous drug abuse as the most significant predictor for final ASES score [F(1,18) = 6.12, p = .024, adjusted R² = .254].

Conclusion

Following isolated shoulder joint sepsis, infection clearance and acceptable functional outcomes can be achieved using surgical I&D followed by a course of antibiotics, but outcomes are variable.

Erratum: Azimuthal Anisotropy of K_{S}^{0} and Λ+Λ[over ¯] Production at Midrapidity from Au+Au Collisions at sqrt[s]_{NN}=130 GeV [Phys. Rev. Lett. 89, 132301 (2002)]

This corrects the article DOI: 10.1103/PhysRevLett.89.132301.

Erratum: Azimuthal Anisotropy at the Relativistic Heavy Ion Collider: The First and Fourth Harmonics [Phys. Rev. Lett. 92, 062301 (2004)]

This corrects the article DOI: 10.1103/PhysRevLett.92.062301.

Complications Associated With Intravenous Antibiotic Treatment for Cutibacterium acnes Periprosthetic Shoulder Infection

Whether positive Cutibacterium acnes cultures during revision shoulder arthroplasty represent true periprosthetic joint infection (PJI), deep tissue inoculant, or laboratory contaminant is a point of substantial controversy. The purpose of this study was to review complications of intravenous antibiotics used for treatment of presumed C acnes shoulder PJI. A study population of 26 patients treated for C acnes PJI with a minimum follow-up of 2 years after operative treatment was established. Complication occurrence and severity were obtained through chart review and phone survey. Sixteen (61.5%) patients experienced a therapeutic complication. Twelve (46.2%) patients experienced a total of 47 antibiotic-associated adverse effects and 10 (38.5%) patients experienced 11 total peripherally inserted central catheter line-associated complications. Female sex carried an increased risk for severe complications (relative risk, 3.3; 95% CI, 1.2-9.5; P=.024). Treatment duration of greater than 6 weeks was a significant predictor for the total number of complications experienced [F(1,23)=5.361; P=.030; adjusted R²=0.189]. Age older than 65 years, treatment duration greater than 6 weeks, and female sex were significant predictors for the number of severe complications [F(3,21)=3.249; P=.042; adjusted R²=0.219]. Treating C acnes infection with intravenous antibiotics carries a substantial risk of adverse events, highlighting the importance of accurate diagnosis of shoulder PJI. Further investigations into the efficacy and safety profile of oral antibiotics for shoulder PJI are necessary. [Orthopedics. 2021;44(3):e422-e426.].

Early Retrieval of Spanning Plates Used for Fixation of Complex Fractures of the Distal Radius

Background  Spanning plates are being increasingly used for the treatment of complex fractures of the distal radius. The traditional recommendation is to leave the hardware in place for at least 12 weeks. Questions/Purpose  This study assesses the comparative outcomes of spanning plates removed at or before 10 weeks. We hypothesized that acceptable healing and functional outcomes can be achieved with earlier hardware removal to allow for earlier range of motion, rehabilitation, and return to function. Patients and Methods  All patients treated for a comminuted, intra-articular distal radius fracture with a temporary spanning plate were identified. Outcomes of bridge plates removed before 10 weeks were compared with plates removed after 12 weeks. Twenty patients in the short duration cohort were compared with 40 patients in the long duration cohort. Results  All fractures healed and there were 10 complications (4 short duration, 6 long duration) and 2 reoperations (1 short duration, 1 long duration) in the study population. There were no significant differences in final Quick-DASH scores (27.4 short duration, 20.9 long duration) or radiographic alignment. Mean values for wrist extension and ulnar deviation were significantly worse in the long duration cohort, although these differences are of unclear clinical significance. Conclusion  It may be safe to remove spanning bridge plates earlier than what is traditionally recommended. Plate removal at or before 10 weeks did not detract from healing or radiographic alignment. Prospective investigations assessing the optimal duration of fixation for this technique are needed. Level of Evidence  This is a Level IV study.

Workers' Compensation Status Confers a Greater Number of Postoperative Visits After Common Upper Extremity Surgeries

Background

The impact of Workers’ Compensation (WC) status on postoperative healthcare utilization in hand and wrist surgery clinical practice is presently unclear. The purpose of this study was to compare the number of postoperative visits in WC to non-WC patients after common upper extremity surgical procedures.

Methodology

All patients who underwent one of four common surgical procedures (carpal tunnel release, De Quervain’s release, cubital tunnel release, and trigger finger release) between 2016 and 2019 were identified. A total of 64 surgeries billed under WC were randomly selected and matched 1:1 to surgeries billed outside of WC based on the primary CPT code.

Results

The most common procedure was carpal tunnel release (42 patients), followed by trigger finger release (30 patients), cubital tunnel release (28 patients), and De Quervain’s release (16 patients). The average number of postoperative visits was 2.3 (median = 2, range: 1-9) and was significantly higher in the WC group (mean/median = 3.0/3 versus 1.5/1, p < 0.001). Within the 90-day global postoperative billing period, the mean number of visits was 2.2 (median = 2, range: 1-4) in the WC group and 1.4 (median = 1, range: 1-3) in the non-WC group (p < 0.001). The average time to clinical discharge in the WC group was 101 days (range: 10-446 days), and in the non-WC group was 40 days (range: 7-474 days) (p < 0.001). Five patients (7.8%) in the WC group and four patients (6.3%) in the non-WC group were seen for unplanned visits after clinical discharge.

Conclusions

WC status conferred more postoperative visits after common upper extremity surgical procedures, both within and beyond the global billing period. Further investigation and targeted strategies are required to address the observed increase in healthcare utilization.

Are Plain X-Rays Necessary in the Diagnosis of De Quervain's Tenosynovitis?

Background  The routine use of plain radiography represents a significant expenditure and has been proven unnecessary in several orthopedic conditions. The utility of plain radiographs in the diagnosis of De Quervain's tenosynovitis (DeQ) is not clear. Questions/Purpose  This study evaluates whether plain radiographic findings routinely predict the need for surgery or alter treatment courses in the initial diagnosis of DeQ. Patients and Methods  A total of 200 patients who received wrist X-rays and had a diagnosis of DeQ were retrospectively selected at random. Their images were evaluated for relevant findings, including radial styloid abnormalities, arthritis, and tendon calcification. A chart review was performed to determine whether these X-rays altered the treatment courses. Results  Of the 200 patients, 141 (69.1%) cases had at least one positive radiographic finding. Carpometacarpal joint (CMC) arthritis was the most common finding, seen in 63 (30.9%) cases. Of all patients, 141 (69.1%) were treated with corticosteroid injection only, 54 (26.5%) with corticosteroid injection and ultimately surgery, and 9 (4.4%) with surgery alone. There were no significant differences in the rates of surgery with positive X-ray findings. There were no cases in which radiographic findings resulted in a change in management, per the report of the treating physician. Conclusions  Despite the high proportion of positive findings on X-ray, no radiographic findings altered the course of treatment in patients with isolated DeQ. Obtaining plain radiographs for isolated DeQ represents a significant cost and should be reserved for cases in which the results are preemptively deemed likely to influence the treatment course. Level of Evidence  This is a level IV study.

Role of microRNA in the pathogenesis of systemic sclerosis tissue fibrosis and vasculopathy

Systemic Sclerosis (SSc) pathogenesis involves multiple immunological, vascular and fibroproliferative abnormalities that contribute to a severe and complex clinical picture. Vasculopathy and fibroproliferative alterations are two hallmark pathological processes in SSc that are responsible for the most severe clinical manifestations of the disease and determine its clinical outcome and mortality. However, the pathogenesis of SSc vasculopathy and of the uncontrolled SSc fibrotic process remain incompletely understood. Recent investigations into the molecular pathways involved in these processes have identified an important role for epigenetic processes that contribute to overall disease progression and have emphasized microRNAs (miRNAs) as crucial epigenetic regulators. MiRNAs hold unique potential for elucidating SSc pathogenesis, improving diagnosis and developing effective targeted therapies for the disease. This review examines the important role that miRNAs play in the development and regulation of vascular and fibroproliferative alterations associated with SSc pathogenesis and their possible participation in the establishment of pathogenetic connections between these two processes. This review also emphasizes that further understanding of the involvement of miRNA in SSc fibrosis and vasculopathy will very likely provide novel future research directions and allow for the identification of groundbreaking therapeutic interventions within these processes. MiR-21, miR- 31, and miR-155 are of particular interest owing to their important involvement in both SSc vasculopathy and fibroproliferative alterations.

Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States

One-neutron knockout reactions have been performed on a beam of radioactive ^{53}Co in a high-spin isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 11^{+} band-termination state, of the proton-rich nucleus ^{52}Co (Z=27, N=25). This has in turn enabled a study of mirror energy differences in the A=52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the experimental observations.

Mirror energy differences at large isospin studied through direct two-nucleon knockout

The first spectroscopy of excited states in 52Ni (T(z)=-2) and 51Co (T(z)=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement.

Forward neutral-pion transverse single-spin asymmetries in p + p collisions at sqrt[s] = 200 GeV

We report precision measurements of the Feynman x (xF) dependence, and first measurements of the transverse momentum (pT) dependence, of transverse single-spin asymmetries for the production of pi0 mesons from polarized proton collisions at sqrt[s] = 200 GeV. The xF dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the pT dependence at fixed xF are not consistent with these same perturbative QCD-based calculations.

Longitudinal double-spin asymmetry for inclusive jet production in p[over -->] + p[over -->] collisions at sqrt[s]=200 GeV

We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p + p collisions at a center-of-mass energy of sqrt[s]=200 GeV. The data, which cover jet transverse momenta 5<p(T)<30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.

Measurement of transverse single-spin asymmetries for Dijet production in proton-proton collisions at sqrt[s]=200 GeV

We report the first measurement of the opening angle distribution between pairs of jets produced in high-energy collisions of transversely polarized protons. The measurement probes (Sivers) correlations between the transverse spin orientation of a proton and the transverse momentum directions of its partons. With both beams polarized, the wide pseudorapidity (-1< or = eta < or = +2) coverage for jets permits separation of Sivers functions for the valence and sea regions. The resulting asymmetries are all consistent with zero and considerably smaller than Sivers effects observed in semi-inclusive deep inelastic scattering. We discuss theoretical attempts to reconcile the new results with the sizable transverse spin effects seen in semi-inclusive deep inelastic scattering and forward hadron production in pp collisions.

Partonic Flow and phi-Meson production in Au+Au collisions at sqrt radical sNN = 200 GeV

We present first measurements of the phi-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from radical sNN=200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Omega to those of the phi as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT approximately 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R CP) of phi follows the trend observed in the K S 0 mesons rather than in Lambda baryons, supporting baryon-meson scaling. These data are consistent with phi mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.

Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV

The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p(T)<10 GeV/c) in p+p, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.

Scaling properties of hyperon production in Au+Au collisions at square root [sNN]=200 GeV

We present the scaling properties of Lambda, Xi, and Omega in midrapidity Au+Au collisions at the Brookhaven National Laboratory Relativistic Heavy Ion Collider at sqrt[s_{NN}]=200 GeV. The yield of multistrange baryons per participant nucleon increases from peripheral to central collisions more rapidly than that of Lambda, indicating an increase of the strange-quark density of the matter produced. The strange phase-space occupancy factor gamma_{s} approaches unity for the most central collisions. Moreover, the nuclear modification factors of p, Lambda, and Xi are consistent with each other for 2<p_{T}<5 GeV/c in agreement with a scenario of hadron formation from constituent quark degrees of freedom.

Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at square root of s = 200 GeV

We report a measurement of the longitudinal double-spin asymmetry A(LL) and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at square root of s = 200 GeV. The cross section data cover transverse momenta 5 < pT < 50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A(LL) data cover 5 < pT < 17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.

Direct observation of dijets in central Au+Au collisions at sqrt[sNN]=200 GeV

The STAR Collaboration at the Relativistic Heavy Ion Collider reports measurements of azimuthal correlations of high transverse momentum (pT) charged hadrons in Au+Au collisions at higher pT than reported previously. As (pT) is increased, a narrow, back-to-back peak emerges above the decreasing background, providing a clear dijet signal for all collision centralities studied. Using these correlations, we perform a systematic study of dijet production and suppression in nuclear collisions, providing new constraints on the mechanisms underlying partonic energy loss in dense matter.

Identified baryon and meson distributions at large transverse momenta from Au + Au collisions at square root sNN=200 GeV

Transverse momentum spectra of pi+/-, p, and p up to 12 GeV/c at midrapidity in centrality selected Au + Au collisions at square root sNN=200 GeV are presented. In central Au + Au collisions, both pi +/- and p(p) show significant suppression with respect to binary scaling at pT approximately >4 GeV/c. Protons and antiprotons are less suppressed than pi+/-, in the range 1.5 approximately < pT approximately < 6 GeV/c. The pi-/pi+ and p/p ratios show at most a weak pT dependence and no significant centrality dependence. The p/pi ratios in central Au + Au collisions approach the values in p + p and d + Au collisions at pT approximately >5 GeV/c. The results at high pT indicate that the partonic sources of pi+/-, p, and p have similar energy loss when traversing the nuclear medium.

Forward neutral pion production in p + p and d + Au collisions at square root sNN=200 GeV

Measurements of the production of forward pi0 mesons from p + p and d + Au collisions at square root sNN=200 GeV are reported. The p + p yield generally agrees with next-to-leading order perturbative QCD calculations. The d + Au yield per binary collision is suppressed as eta increases, decreasing to approximately 30% of the p + p yield at eta =4.00, well below shadowing expectations. Exploratory measurements of azimuthal correlations of the forward pi0 with charged hadrons at eta approximately 0 show a recoil peak in p + p that is suppressed in d + Au at low pion energy. These observations are qualitatively consistent with a saturation picture of the low-x gluon structure of heavy nuclei.

Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions

We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Distributions of charged hadrons associated with high transverse momentum particles in pp and Au+Au collisions at sqrt[sNN]=200 GeV

Charged hadrons in [EQUATION: SEE TEXT] associated with particles of [EQUATION: SEE TEXT] are reconstructed in pp and Au+Au collisions at sqrt[sNN]=200 GeV. The associated multiplicity and p magnitude sum are found to increase from pp to central Au+Au collisions. The associated p distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed.

Multistrange Baryon elliptic flow in Au+Au collisions at square root of sNN=200 GeV

We report on the first measurement of elliptic flow v2(pT) of multistrange baryons Xi- +Xi+ and Omega- + Omega+ in heavy-ion collisions. In minimum-bias Au+Au collisions at square root of s(NN)=200 GeV, a significant amount of elliptic flow, comparable to other nonstrange baryons, is observed for multistrange baryons which are expected to be particularly sensitive to the dynamics of the partonic stage of heavy-ion collisions. The pT dependence of v2 of the multistrange baryons confirms the number of constituent quark scaling previously observed for lighter hadrons. These results support the idea that a substantial fraction of the observed collective motion is developed at the early partonic stage in ultrarelativistic nuclear collisions at the Relativistic Heavy Ion Collider.

Multiplicity and pseudorapidity distributions of photons in Au+Au collisions at square root of (S(NN)) = 62.4 GeV

We present the first measurement of pseudorapidity distribution of photons in the region 2.3 < or = eta < or = 3.7 for different centralities in Au+Au collisions at square root of (S(NN)) = 62.4 GeV. We find that the photon yield scales with the number of participating nucleons at all collision centralities studied. The pseudorapidity distribution of photons, dominated by pi0 decays, has been compared to those of charged pions, photons, and inclusive charged particles from heavy-ion and nucleon-nucleon collisions at various energies. The photon production has been shown to be consistent with the energy and centrality independent limiting fragmentation scenario.

Open charm yields in d+Au collisions at squareroot[sNN]=200 GeV

Midrapidity open charm spectra from direct reconstruction of D0(D0)-->K-/+pi+/- in d+Au collisions and indirect electron-positron measurements via charm semileptonic decays in p+p and d+Au collisions at squareroot[sNN]=200 GeV are reported. The D0(D0) spectrum covers a transverse momentum (pT) range of 0.1<pT<3 GeV/c, whereas the electron spectra cover a range of 1<pT<4 GeV/c. The electron spectra show approximate binary collision scaling between p+p and d+Au collisions. From these two independent analyses, the differential cross section per nucleon-nucleon binary interaction at midrapidity for open charm production from d+Au collisions at BNL RHIC is dsigma(NN)cc/dy=0.30+/-0.04(stat)+/-0.09(syst) mb. The results are compared to theoretical calculations. Implications for charmonium results in A+A collisions are discussed.

Azimuthal anisotropy and correlations at large transverse momenta in p + p and Au + Au collisions at square root sNN=200 GeV

Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au + Au collisions at square root s(NN)=200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au + Au collisions to those in p + p at the same energy. The elliptic anisotropy v(2) is found to reach its maximum at p(t) approximately 3 GeV/c, then decrease slowly and remain significant up to p(t) approximately 7-10 GeV/c. Stronger suppression is found in the back-to-back high-p(t) particle correlations for particles emitted out of plane compared to those emitted in plane. The centrality dependence of v(2) at intermediate p(t) is compared to simple models based on jet quenching.

Multistrange baryon production in Au-Au collisions at sqrt[s(NN)]=130 GeV

The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (-)Xi(+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.

Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at sqrt[s]=200 GeV

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider.

Identified particle distributions in pp and Au+Au collisions at square root of (sNN)=200 GeV

Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

Rho0 production and possible modification in Au+Au and p+p collisions at square root [sNN] = 200 GeV

We report results on rho(770)(0)-->pi(+)pi(-) production at midrapidity in p+p and peripheral Au+Au collisions at sqrt[s(NN)]=200 GeV. This is the first direct measurement of rho(770)(0)-->pi(+)pi(-) in heavy-ion collisions. The measured rho(0) peak in the invariant mass distribution is shifted by approximately 40 MeV/c(2) in minimum bias p+p interactions and approximately 70 MeV/c(2) in peripheral Au+Au collisions. The rho(0) mass shift is dependent on transverse momentum and multiplicity. The modification of the rho(0) meson mass, width, and shape due to phase space and dynamical effects are discussed.

Azimuthal anisotropy at the relativistic heavy ion collider: the first and fourth harmonics

We report the first observations of the first harmonic (directed flow, v(1)) and the fourth harmonic (v(4)), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v(2)) generated at RHIC. From the correlation of v(2) with v(1) it is determined that v(2) is positive, or in-plane. The integrated v(4) is about a factor of 10 smaller than v(2). For the sixth (v(6)) and eighth (v(8)) harmonics upper limits on the magnitudes are reported.

Particle-type dependence of azimuthal anisotropy and nuclear modification of particle production in Au+Au collisions at square root of sNN=200 GeV

We present STAR measurements of the azimuthal anisotropy parameter v(2) and the binary-collision scaled centrality ratio R(CP) for kaons and lambdas (Lambda+Lambda) at midrapidity in Au+Au collisions at square root of s(NN)=200 GeV. In combination, the v(2) and R(CP) particle-type dependencies contradict expectations from partonic energy loss followed by standard fragmentation in vacuum. We establish p(T) approximately 5 GeV/c as the value where the centrality dependent baryon enhancement ends. The K(0)(S) and Lambda+Lambda v(2) values are consistent with expectations of constituent-quark-number scaling from models of hadron formation by parton coalescence or recombination.