Sarcopenia is an independent risk factor for failure to achieve the 1-year MCID of the KOOS, JR and PROMIS PF-SF10a after TKA.

BACKGROUND: Sarcopenia, which is a progressive and multifactorial condition of decreased muscle strength, has been identified as an independent predictor for falls, revision, infection, and readmissions following total knee arthroplasty (TKA), but its association to patient reported outcomes (PROMs) is less studied. The aim of this study is to determine if sarcopenia and other measures of body composition are correlated with ability to achieve the 1-year minimal clinically important difference (MCID) of the KOOS JR and PROMIS-PF-SF10a following primary TKA. METHODS: A multicenter retrospective case-control study was performed. Inclusion criteria consisted of patients over the age of 18 undergoing primary TKA, body composition metrics determined by computed tomography (CT), and available pre- and post-operative PROM scores. Predictors of achievement of the 1-year MCID of the KOOS JR and PROMIS PF-SF-10a were determined through a multivariate linear regression. RESULTS: 140 primary TKAs met inclusion criteria. 74 (52.85%) patients achieved the 1-year KOOS, JR MCID and 108 (77.41%) patients achieved the 1-year MCID for the PROMIS PF-SF10a. Sarcopenia was independently associated with decreased odds of achieving the MCID of both the KOOS, JR (OR 0.31, 95%CI 0.10-0.97, p = 0.04) and the PROMIS-PF-SF10a (OR 0.32, 95%CI 0.12-0.85, p = 0.02) CONCLUSIONS: In our study, sarcopenia was independently associated with increased odds of failure to achieve the 1-year MCID of the KOOS, JR and PROMIS PF-SF10a after TKA. Early identification of sarcopenic patients may be beneficial for arthroplasty surgeons so that targeted nutritional counseling and exercises can be recommended prior to TKA.

Flexion Space Balancing Through Component Positioning and Its Relationship to Traditional Anatomic Rotational Landmarks in Robotic Total Knee Arthroplasty.

BACKGROUND: The use of the femoral component position to balance the flexion space and its relationship to the transepicondylar axis (TEA) and posterior condylar angle (PCA) has not been thoroughly evaluated. METHODS: A total of 233 patients undergoing robotic arm-assisted total knee arthroplasty were evaluated. Native TEA and PCA were established on preoperative computed tomography scans. Femoral component rotation was set in the axial plane to match the native trochlea and native medial femoral condyle to set the flexion gap. Knee flexion space gaps and component position were recorded. The relationship of the femoral component to the native TEA, PCA, and preoperative radiographic landmarks was evaluated. RESULTS: The intraoperative measured medial flexion space gap did not significantly correlate with the relationship of the femoral component to the PCA or TEA in varus or valgus knees. In varus knees, the preoperative mechanical axis alignment had a positive relationship to femoral component position when compared to the PCA (P = .04) and TEA (P = .002). In valgus knees, there was a positive correlation between the preoperative lateral distal femoral angle and component position when compared to the PCA (P = .04) only. CONCLUSION: Intraoperative measured flexion space balance through femoral component positioning did not correlate with its relationship to the native TEA or PCA. In varus knees, the preoperative mechanical axis alignment correlated with an increase in femoral component external rotation to the TEA and PCA. In valgus knees, the severity of preoperative lateral distal femoral angle correlated with the rotational relationship of the femoral component to the PCA only.

Variation in Diagnoses for Hip Arthroplasty Among New York State Hospitals: Implications for the Comprehensive Care for Joint Replacement Model.

BACKGROUND: The Comprehensive Care for Joint Replacement model is designed to minimize costs and improve quality for Medicare patients undergoing joint arthroplasty. The cost of hip arthroplasty (HA) episode varies depending on the preoperative diagnosis and is greater for fracture than for osteoarthritis. Hospitals that perform a higher percentage of HA for OA may therefore have an advantage in the Comprehensive Care for Joint Replacement model. The purposes of this study are to (1) determine the variability in underlying diagnosis for HA in New York State hospitals, and (2) determine hospital characteristics, such as volume, associated with this. METHODS: The New York Statewide Planning and Research Cooperative System database was used to identify 127,206 primary HA procedures from 2010 to 2014. The data included underlying diagnoses, age, length of stay, and total charges. Hospitals were categorized by volume and descriptive statistics were used. RESULTS: OA was the underlying diagnosis for HA for 74.2% of all patients; this was significantly higher for high-volume (89.30%) and medium-volume (74.9%) hospitals than for low-volume hospitals (58.4%, P < .05). HA for fracture was significantly more common at low-volume hospitals (32.4%) compared to medium-volume (18.0%) and high-volume (4.7%) hospitals (P < .05). Length of stay was significantly greater at low-volume hospitals for all diagnoses. CONCLUSION: High-volume hospitals perform a higher ratio of HA cases for OA compared to fracture, which may lead to advantages in patient outcomes and cost. The variation in underlying diagnosis between hospitals has financial implications and underscores the need for HAs to be risk stratified by preoperative diagnosis.

Utilization of Lumbar Spinal Fusion in New York State: Trends and Disparities.

STUDY DESIGN: Retrospective review of an administrative database. OBJECTIVE: To observe New York statewide trends in lumbar spine surgery and to compare utilization of fusion according to hospital size and patient population. SUMMARY OF BACKGROUND DATA: Over the last 30 years, studies have indicated increasing rates of spinal fusion procedures performed each year in the United States. There is no study investigating potential variability in this trend according to hospital volume. METHODS: New York Statewide Planning and Research Cooperative System (SPARCS) administrative data were used to identify 228,882 lumbar spine surgery patients. New York State hospitals were categorized as low-, medium-, or high-volume and descriptive statistics were used to determine trends in spinal fusion. RESULTS: The number of fusions per year increased 55% from 2005 to 2014. The ratio of fusion to nonfusion surgery increased from 0.88 to 2.67 at high-volume, from 0.84 to 2.30 at medium- volume, and from 0.66 to 1.52 at low-volume hospitals. In 2014, 22% of spine surgery patients at low-volume hospitals were either African Americans or Hispanics compared with 12% and 14% at high- and medium-volume hospitals, respectively. At high-volume hospitals, 33% of patients were privately insured and 3% had Medicare compared with 30% and 6% at low-volume hospitals. CONCLUSION: The annual number of lumbar spinal fusions continues to increase, especially at high- and medium-volume hospitals. The percentage of patients treated surgically for lumbar spinal stenosis that undergoes fusion ranges from 53.2 to 66.4% depending on hospital volume. Individual surgeon opinion, patient disease characteristics, and socioeconomic factors may affect surgical decision making. Caucasians and private insurance patients most often receive care at high-volume hospitals. Minorities and patients with Medicaid are over-represented at low-volume centers where fusions are less often performed. Accessibility to care at high-volume centers remains a major concern for these vulnerable populations. LEVEL OF EVIDENCE: 3.

A Review of Symptomatic Lumbosacral Transitional Vertebrae: Bertolotti's Syndrome.

BACKGROUND: Lumbosacral transitional vertebrae (LSTV) are increasingly recognized as a common anatomical variant associated with altered patterns of degenerative spine changes. This review will focus on the clinical significance of LSTV, disruptions in normal spine biomechanics, imaging techniques, diagnosis, and treatment. METHODS: A Pubmed search using the specific key words "LSTV," "lumbosacral transitional vertebrae," and "Bertolotti's Syndrome" was performed. The resulting group of manuscripts from our search was evaluated. RESULTS: LSTV are associated with alterations in biomechanics and anatomy of spinal and paraspinal structures, which have important implications on surgical approaches and techniques. LSTV are often inaccurately detected and classified on standard AP radiographs and MRI. The use of whole-spine images as well as geometric relationships between the sacrum and lumbar vertebra increase accuracy. Uncertainty regarding the cause, clinical significance, and treatment of LSTV persists. Some authors suggest an association between LSTV types II and IV and low back pain. Pseudoarticulation between the transverse process and the sacrum creates a "false joint" susceptible to arthritic changes and osteophyte formation potentially leading to nerve root entrapment. The diagnosis of symptomatic LSTV is considered with appropriate patient history, imaging studies, and diagnostic injections. A positive radionuclide study along with a positive effect from a local injection helps distinguish the transitional vertebra as a significant pain source. Surgical resection is reserved for a subgroup of LSTV patients who fail conservative treatment and whose pain is definitively attributed to the anomalous pseudoarticulation. CONCLUSIONS: Due to the common finding of low back pain and the wide prevalence of LSTV in the general population, it is essential to differentiate between symptoms originating from an anomalous psuedoarticulation from other potential sources of low back pain. Further studies with larger sample sizes and longer follow-up time would better demonstrate the effectiveness of surgical resection and help guide treatment.

Diagnostic tests for concussion: is vision part of the puzzle?

BACKGROUND: Concussion, particularly in relation to sports and combat activities, is increasingly recognized as a potential cause of both short- and long-term neurologic sequelae. This review will focus on the neuro-ophthalmologic findings associated with concussion, the current tests for concussion, and the potential for visual performance measures to improve our detection and assessment of concussions. EVIDENCE ACQUISITION: A PubMed search using the specific key words "concussion," "mild traumatic brain injury," "neuro-ophthalmological findings," and "diagnostic and management tests" was performed. An emphasis was placed on articles published during the past 5 years, but additional articles referenced within recent publications were obtained. RESULTS: Concussion is frequently associated with abnormalities of saccades, pursuit eye movements, convergence, accommodation, and the vestibular-ocular reflex. Current sideline testing for athletes includes the Sports Concussion Assessment Tool, Third Edition (SCAT3) incorporates cognitive and balance testing. The King-Devick (K-D) test is a rapid visual performance measures that can be used on sidelines by nonmedical personnel, including parents of youth athletes. The K-D test complements components of the SCAT3 and improves the detection of concussions. Other vision-based tools for diagnosing and for managing concussion include eye movement tracking devices, pupillary assessment, computerized testing, imaging modalities, and eletrophysiologic testing. Many of the imaging modalities and electrophysiological studies have been combined with vision-based tests. CONCLUSIONS: Concusssion is associated with many neuro-ophthalmologic signs and symptoms. Visual performance measures enhance the detection and management of concussion, and future studies are under way to further incorporate vision-based testing into sideline diagnosis and long-term clinical assessments.

The level of origin firing inversely affects the rate of replication fork progression.

DNA damage slows DNA synthesis at replication forks; however, the mechanisms remain unclear. Cdc7 kinase is required for replication origin activation, is a target of the intra-S checkpoint, and is implicated in the response to replication fork stress. Remarkably, we found that replication forks proceed more rapidly in cells lacking Cdc7 function than in wild-type cells. We traced this effect to reduced origin firing, which results in fewer replication forks and a consequent decrease in Rad53 checkpoint signaling. Depletion of Orc1, which acts in origin firing differently than Cdc7, had similar effects as Cdc7 depletion, consistent with decreased origin firing being the source of these defects. In contrast, mec1-100 cells, which initiate excess origins and also are deficient in checkpoint activation, showed slower fork progression, suggesting the number of active forks influences their rate, perhaps as a result of competition for limiting factors.