A Feasibility Study of Percutaneous Peripheral Nerve Stimulation for the Treatment of Postoperative Pain Following Total Knee Arthroplasty.

INTRODUCTION: The objective of the present feasibility study was to investigate the use of a new treatment modality-percutaneous peripheral nerve stimulation (PNS)-in controlling the often severe and long-lasting pain following total knee arthroplasty (TKA). METHODS: For patients undergoing a primary, unilateral TKA, both femoral and sciatic open-coil percutaneous leads (SPR Therapeutics, Cleveland, OH) were placed up to seven days prior to surgery using ultrasound guidance. The leads were connected to external stimulators and used both at home and in the hospital for up to six weeks total. RESULTS: In six of seven subjects (86%), the average of daily pain scores across the first two weeks was <4 on the 0-10 Numeric Rating Scale for pain. A majority of subjects (four out of seven; 57%) had ceased opioid use within the first week (median time to opioid cessation for all subjects was six days). Gross sensory/motor function was maintained during stimulation, enabling stimulation during physical therapy and activities of daily living. At 12 weeks following surgery, six of seven subjects had improved by >10% on the Six-Minute Walk Test compared to preoperative levels, and WOMAC scores improved by an average of 85% compared to before surgery. No falls, motor block, or lead infections were reported. CONCLUSIONS: This feasibility study suggests that for TKA, ultrasound-guided percutaneous PNS is feasible in the immediate perioperative period and may provide analgesia without the undesirable systemic effects of opioids or quadriceps weakness induced by local anesthetics-based peripheral nerve blocks.

What Is the Optimal Minimum Penetration Depth for "All-Inside" Meniscal Repairs?

PURPOSE: To identify desired minimum depth setting for safe, effective placement of the all-inside meniscal suture anchors. METHODS: Using 16 cadaveric knees and standard arthroscopic techniques, 3-dimensional surfaces of the meniscocapsular junction and posterior capsule were digitized. Using standard anteromedial and anterolateral portals, the distance from the meniscocapsular junction to the posterior capsule outer wall was measured for 3 locations along the posterior half of medial and lateral menisci. Multiple all-inside meniscal repairs were performed on 7 knees to determine an alternate measure of capsular thickness (X2) and compared with the digitized results. RESULTS: In the digitized group, the distance (X1) from the capsular junction to the posterior capsular wall was averaged in both menisci for 3 regions using anteromedial and anterolateral portals. Mean distances of 6.4 to 8.8 mm were found for the lateral meniscus and 6.5 to 9.1 mm for the medial meniscus. The actual penetration depth was determined in the repair group and labeled X2. It showed a similar pattern to the variation seen in X1 by region, although it exceeded predicted distances an average 1.7 mm in the medial and 1.5 mm in the lateral meniscus owing to visible deformation of the capsule as it pierced. CONCLUSIONS: Capsular thickness during arthroscopic repair measures approximately 6 to 9 mm (X1), with 1.5 to 2 mm additional depth needed to ensure penetration rather than bulging of the posterior capsule (X2), resulting in 8 to 10 mm minimum penetration depth range. Surgeons can add desired distance away from the meniscocapsular junction (L) at device implantation, finding optimal minimal setting for penetration depth (X2 + L), which for most repairable tears may be as short as 8 mm and not likely to be greater than 16 mm. CLINICAL RELEVANCE: Minimum depth setting for optimal placement of all-inside meniscal suture anchors when performing all-inside repair of the medial or lateral meniscus reduces risk of harming adjacent structures secondary to overpenetration and underpenetration of the posterior capsule.

Comparative single-cell transcriptional and proteomic atlas of clinical-grade injectable mesenchymal source tissues.

Bone marrow aspirate concentrate (BMAC) and adipose-derived stromal vascular fraction (ADSVF) are the most marketed stem cell therapies to treat a variety of conditions in the general population and elite athletes. Both tissues have been used interchangeably clinically even though their detailed composition, heterogeneity, and mechanisms of action have neither been rigorously inventoried nor compared. This lack of information has prevented investigations into ideal dosages and has facilitated anecdata and misinformation. Here, we analyzed single-cell transcriptomes, proteomes, and flow cytometry profiles from paired clinical-grade BMAC and ADSVF. This comparative transcriptional atlas challenges the prevalent notion that there is one therapeutic cell type present in both tissues. We also provide data of surface markers that may enable isolation and investigation of cell (sub)populations. Furthermore, the proteome atlas highlights intertissue and interpatient heterogeneity of injected proteins with potentially regenerative or immunomodulatory capacities. An interactive webtool is available online.

A Retrospective Study of the Impact of COVID-19 Pandemic Related Administrative Restrictions on Spine Surgery Practice and Outcomes in an Urban Healthcare System.

The study objective is to characterize the impact of COVID-19 related hospital administrative restrictions on patient demographics, surgical care, logistics, and patient outcomes in spine surgery. This was a retrospective study of 331 spine surgery patients at UCSD conducted during 1 March 2019-31 May 2019 (pre-COVID-19) and 1 March 2020-31 May 2020 (first COVID-19 surge). All variables were collected through RedCap and compared between pre- and during-COVID groups. There were no significant differences in patient demographics, operating room duration, and skin-to-skin time. However, length of stay was 4.7 days shorter during COVID-19 (p = 0.03) and more cases were classified as 'urgent' (p = 0.04). Preoperative pain scores did not differ between groups (p = 0.51). However, pain levels at discharge were significantly higher during COVID (p = 0.04) and trended towards remaining higher in the short- (p = 0.05) but not long-term (p = 0.17) after surgery. There was no significant difference in the number of post-operative complications, but there was an increase in the use of the emergency room and telemedicine to address complications when they arose. Overall, the pandemic resulted in a greater proportion of 'urgent' spine surgery cases and shorter length of hospital stay. Pain levels upon discharge and at short-term timepoints were higher following surgery but did not persist in the long term.

Acetabular Bone Marrow Aspiration During Total Hip Arthroplasty.

Biologically augmented surgical treatments of orthopaedic conditions are increasingly popular. Bone marrow aspirate concentrate is a key orthobiologic tissue source, and the field is moving from the standard iliac crest marrow aspiration toward local aspirations of marrow depots that are accessible during the standard-of-care procedures in an attempt to reduce morbidity, surgery time, and cost. Here, we present the aspiration of the standard iliac marrow depot, but through a novel acetabular approach during total hip arthroplasty. This procedure markedly simplifies biologic augmentation with bone marrow aspirate concentrate in this large patient cohort.

Surgical site peptidylarginine deaminase 4 (PAD4), a biomarker of NETosis, correlates with insulin resistance in total joint arthroplasty patients: A preliminary report.

While obesity and insulin resistance are known risk factors for wound complications after total joint arthroplasty (TJA), the biologic causes remain to be elucidated. Recently, neutrophil extracellular trap formation (NETosis) was identified as a mediator of delayed wound healing in insulin resistant states. Herein, we explored the relationship between obesity, insulin resistance and biomarkers of NET formation in TJA subjects. We enrolled 14 obese (body mass index [BMI]≥30 kg/m2), and 15 lean (BMI<30 kg/m2) subjects undergoing primary knee or hip TJA. On the day of surgery, skeletal muscle proximal to the operated joint and plasma were collected. Protein abundance of NETosis biomarkers, peptidylarginine deaminase 4 (PAD4) and neutrophil elastase (NE) were assessed in skeletal muscle by immunoblotting and metabolic parameters (glucose, insulin, triglycerides, free fatty acids) and cell-free double-stranded DNA (cf-dsDNA) were assessed in plasma and were correlated with obesity and insulin resistance (as measured by the homeostatic model assessment for insulin resistance). When comparing lean and obese subjects, there were no significant differences in plasma cf-dsDNA or skeletal muscle NE or PAD4 abundance. In contrast, skeletal muscle PAD4 abundance, but not NE or plasma cf-dsDNA, was positively correlated with insulin resistance. Compared to insulin sensitive subjects, insulin resistant TJA subjects have higher expression of PAD4 at the surgical site and therefore may have higher rates of NET formation, which may lead to delayed surgical site wound healing.

Strategies to Identify Mesenchymal Stromal Cells in Minimally Manipulated Human Bone Marrow Aspirate Concentrate Lack Consensus.

BACKGROUND: There is a need to identify and quantify mesenchymal stromal cells (MSCs) in human bone marrow aspirate concentrate (BMAC) source tissues, but current methods to do so were established in cultured cell populations. Given that surface marker and gene expression change in cultured cells, it is doubtful that these strategies are valid to quantify MSCs in fresh BMAC. PURPOSE: To establish the presence, quantity, and heterogeneity of BMAC-derived MSCs in minimally manipulated BMAC using currently available strategies. STUDY DESIGN: Descriptive laboratory study. METHODS: Five published strategies to identify MSCs were compared for suitability and efficiency to quantify clinical-grade BMAC-MSCs and cultured MSCs at the single cell transcriptome level on BMAC samples being used clinically from 15 orthopaedic patients and on 1 cultured MSC sample. Strategies included (1) the guidelines by the International Society for Cellular Therapy (ISCT), (2) CD271 expression, (3) the Ghazanfari et al transcriptional profile, (4) the Jia et al transcriptional profile, and (5) the Silva et al transcriptional profile. RESULTS: ISCT guidelines did not identify any MSCs in BMAC at the transcriptional level and only 1 in 9 million cells at the protein level. Of 12,850 BMAC cells, 9 expressed the CD271 gene. Only 116 of 396 Ghazanfari genes were detected in BMAC, whereas no cells expressed all of them. No cells expressed all Jia genes, but 25 cells expressed at least 13 of 22. No cells expressed all Silva genes, but 19 cells expressed at least 8 of 23. Most importantly, the liberalized strategies tended to identify different cells and most of them clustered with immune cells. CONCLUSION: Currently available methods need to be liberalized to identify any MSCs in fresh human BMAC and lack consensus at the single cell transcriptome and protein expression levels. These different cells should be isolated and challenged to establish phenotypic differences. CLINICAL RELEVANCE: This study demonstrated that improved strategies to quantify MSC concentrations in BMAC for clinical applications are urgently needed. Until then, injected minimally manipulated MSC doses should be reported as rough estimates or as unknown.

A randomized cross-over study of the quality of cardiopulmonary resuscitation among females performing 30:2 and hands-only cardiopulmonary resuscitation.

BACKGROUND: Hands-Only cardiopulmonary resuscitation (CPR) is recommended for use on adult victims of witnessed out-of-hospital (OOH) sudden cardiac arrest or in instances where rescuers cannot perform ventilations while maintaining minimally interrupted quality compressions. Promotion of Hands-Only CPR should improve the incidence of bystander CPR and, subsequently, survival from OOH cardiac arrest; but, little is known about a rescuer's ability to deliver continuous chest compressions of adequate rate and depth for periods typical of emergency services response time. This study evaluated chest compression rate and depth as subjects performed Hands-Only CPR for 10 minutes. For comparison purposes, each also performed chest compressions with ventilations (30:2) CPR. It also evaluated fatigue and changes in body biomechanics associated with each type of CPR. METHODS: Twenty healthy female volunteers certified in basic life support performed Hands-Only CPR and 30:2 CPR on a manikin. A mixed model repeated measures cross-over design evaluated chest compression rate and depth, changes in fatigue (chest compression force, perceived exertion, and blood lactate level), and changes in electromyography and joint kinetics and kinematics. RESULTS: All subjects completed 10 minutes of 30:2 CPR; but, only 17 completed 10 minutes of Hands-Only CPR. Rate, average depth, percentage at least 38 millimeters deep, and force of compressions were significantly lower in Hands-Only CPR than in 30:2 CPR. Rates were maintained; but, compression depth and force declined significantly from beginning to end CPR with most decrement occurring in the first two minutes. Perceived effort and joint torque changes were significantly greater in Hands-Only CPR. Performance was not influenced by age. CONCLUSION: Hands-Only CPR required greater effort and was harder to sustain than 30:2 CPR. It is not known whether the observed greater decrement in chest compression depth associated with Hands-Only CPR would offset the potential physiological benefit of having fewer interruptions in compressions during an actual resuscitation. The dramatic decrease in compression depth in the first two minutes reinforces current recommendations that rescuers take turns performing compressions, switching every two minutes or less. Further study is recommended to determine the impact of real-time feedback and dispatcher coaching on rescuer performance.