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Knee pain is a common complaint in older patients, and osteoarthritis is the leading cause. We prospectively evaluated the diagnostic patterns of nonorthopedic physicans in 100 consecutive patients older than 60 years who had knee pain. Our study shows that there is a lack of consensus about the use of radiographic studies for diagnosis of knee pain in older patients. Weight-bearing radiographs are ideal for evaluating knee pain. MRI frequently is overly sensitive in detecting pathology and often underestimates joint-space narrowing and arthrosis. MRI also represents a much larger cost and burden on the health care system. MRI is indicated when the cause of knee pain is not readily apparent after careful physical and radiographic evaluation. [ABSTRACT FROM AUTHOR]

Background and Objectives: Peripheral nerve blocks have been integrated into most multimodal analgesia protocols for total knee arthroplasty (TKA). The adductor canal block (ACB) has gained popularity because of its quadriceps muscle sparing. Similarly, local anesthetic injection between the popliteal artery and the posterior capsule of the knee, IPACK block, has been described to provide analgesia to the posterior capsule of the knee with motor-sparing qualities. This prospective randomized controlled trial aimed to assess the analgesic efficacy of adding the IPACK block to our current multimodal analgesic regimen, including the ACB, in patients undergoing primary TKA., Methods: 119 patients were randomized to receive either an IPACK or a sham block in addition to multimodal analgesia and an ACB. We were set to assess pain in the back of the knee 6 hours after surgery. Other end points included quality of recovery after surgery, pain scores, opioid requirements, and functional measures., Results: Patients who received the IPACK block had less pain in the back of the knee 6 hours after surgery when compared with the sham block: 21.7% vs 45.8%, p<0.01. There was marginal improvement in other pain measures in the first 24 hours after surgery. However, opioid requirements, quality of recovery and functional measures were similar between the two groups., Conclusion: The IPACK block reduced the incidence of posterior knee pain 6 hours postoperatively., Competing Interests: Competing interests: Dr Elkassabany is a consultant for Foundry therapeutics. Dr Nelson declares working as a consultant for Acutive Medical, Allentwon, Pennsylvania and for Zimmer Biomet., (© American Society of Regional Anesthesia & Pain Medicine 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Spinal anesthesia (SA) for Total Knee Arthroplasty (TKA) may be associated with better patients' outcomes. This study aims to assess the association between preoperative education about the advantage of SA over general anesthesia (GA) for TKA and the likelihood of patient choice of NA., Methods: Patients undergoing unilateral primary TKA were identified. Type of anesthesia (GA or SA), attendance of the (joints class), patient demographics, ASA status, anticoagulation status, and diagnosis of back problems were recoded. Regression analysis was used to assess the association between the type of anesthesia and attendance of the joints class., Results: 1010 patients were identified to have unilateral primary TKA. 31% of patients attended the joint class. Patients who attended the joints class were more likely to receive SA when compared to those who did not attend (OR=1.7, CI: 1.2-2.5, P=0.004) after adjusting for other variables., Conclusion: Preoperative education about advantages of SA may be associated with an increase in patients receiving SA for TKA., Practice Implications: Increase in patients receiving SA for TKA may improve outcomes., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Adductor canal block (ACB) has emerged as an appealing alternative to femoral nerve block (FNB) that produces a predominantly sensory nerve block by anesthetizing the saphenous nerve. Studies have shown greater quadriceps strength preservation with ACB compared with FNB, but no advantage has yet been shown in terms of fall risk. The Tinetti scale is used by physical therapists to assess gait and balance, and total score can estimate a patient's fall risk. We designed this study to test the primary hypothesis that FNB results in a greater proportion of "high fall risk" patients postoperatively using the Tinetti score compared with ACB., Methods: After institutional review board approval, informed written consent to participate in the study was obtained. Patients undergoing primary unilateral total knee arthroplasty were eligible for enrollment in this double-blind, randomized trial. Patients received either an ACB or FNB (20 mL of 0.5% ropivacaine) with catheter placement (8 mL/h of 0.2% ropivacaine) in the setting of multimodal analgesia. Continuous infusion was stopped in the morning of postoperative day (POD)1 before starting physical therapy (PT). On POD1, PT assessed the primary outcome using the Tinetti score for gait and balance. Patients were considered to be at high risk of falling if they scored <19. Secondary outcomes included manual muscle testing of the quadriceps muscle strength, Timed Up and Go (TUG) test, and ambulation distance on POD1 and POD2. The quality of postoperative analgesia and the quality of recovery were assessed with American Pain Society Patient Outcome Questionnaire Revised and Quality of Recovery-9 questionnaire, respectively., Results: Sixty-two patients were enrolled in the study (31 ACB and 31 FNB). No difference was found in the proportion of "high fall risk" patients on POD1 (21/31 in the ACB group versus 24/31 in the FNB group [P = 0.7]; relative risk, 1.14 [95% confidence interval, 0.84-1.56]) or POD2 (7/31 in the ACB versus 14/31 in the FNB group [P = 0.06]; relative risk, 2.0 [95% confidence interval, 0.94-4.27]). The average distance of ambulation during PT and time to up and go were similar on POD1 and POD2. Manual muscle testing grades were significantly higher on POD1 in the ACB group when compared with that in the FNB (P = 0.001) (Wilcoxon-Mann-Whitney odds, 2.25 [95% confidence interval, 1.35-4.26]). There were no other differences in postoperative outcomes., Conclusions: ACB results in greater preservation of quadriceps muscle strength. Although we did not detect a significant reduction in fall risk when compared with FNB, based on the upper limit of the relative risk, it may very well be present. Further study is needed with a larger sample size.

Unlabelled: Bone tissue adapts to its functional environment by optimizing its morphology for mechanical demand. Among the mechanosensitive cells that recognize and respond to forces in the skeleton are osteocytes, osteoblasts, and mesenchymal progenitor cells (MPCs). Therefore, the ability to use mechanical signals to improve bone health through exercise and devices that deliver mechanical signals is an attractive approach to age-related bone loss; however, the extracellular or circulating mediators of such signals are largely unknown. Using SDS-PAGE separation of proteins secreted by MPCs in response to low-magnitude mechanical signals and in-gel trypsin digestion followed by HPLC and mass spectroscopy, we identified secreted proteins up-regulated by vibratory stimulation. We exploited a cell senescence-associated secretory phenotype screen and reasoned that a subset of vibration-induced proteins with diminished secretion by senescent MPCs will have the capacity to promote bone formation in vivo. We identified one such vibration-induced bone-enhancing (vibe) gene as R-spondin 1, a Wnt pathway modulator, and demonstrated that it has the capacity to promote bone formation in three mouse models of age-related bone loss. By virtue of their secretory status, some vibe proteins may be candidates for pre-clinical development as anabolic agents for the treatment of osteoporosis., Key Message: Mesenchymal stem cells respond to low magnitude mechanical signals (vibration). R-Spondin 1 is upregulated by mechanical signals and secreted. R-Spondin 1 promotes bone formation in three mouse models of osteoporosis.

Unlabelled: Early treatment of osteonecrosis of the femoral head yields better results than late treatment. Because osteonecrosis frequently is bilateral, it often is advisable to treat both hips simultaneously. Core decompression is one of the more common methods of treatment; however the safety of doing simultaneous bilateral core decompression has been questioned. We sought to evaluate the safety and effectiveness of simultaneous bilateral core decompression compared with unilateral core decompression. One hundred ninety-three patients (276 hips) who had core decompression with bone grafting were followed up for 24 to 145 months. One hundred twenty-four procedures were unilateral and 152 were bilateral. Patients were evaluated by change in Harris hip score, radiographic progression, postoperative complications, and conversion to total hip arthroplasty. Total hip arthroplasty was required in 56 of 124 (45%) of hips in the unilateral, and 48 of 152 (32%) of hips in the bilateral group. Postoperative complications were similar. In the unilateral group there were two major and nine minor complications; in the bilateral group there were three major and 10 minor complications. When bilateral core decompression is indicated, it can be done simultaneously on both hips, allowing earlier treatment of the contralateral hip without risk of increased complications and possibly with a better outcome. It requires only one hospitalization and decreases recovery time compared with two separate procedures. Therefore, it provides advantages over procedures that cannot be done simultaneously on both hips., Level of Evidence: Therapeutic study, Level IV (case series-no common or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

This article describes a technique of ankle arthrodesis using a triangular external fixation frame and presents the results of biomechanical analysis and clinical experience with the frame. Clinical evaluation of 23 ankle arthrodeses performed using a triangular external fixation frame yielded a 91.3% fusion rate at an average of 11 weeks postfusion. The triangular frame was 79% stiffer than a compression-only external frame in torsion and 39% stiffer in anteroposterior bending. This high rate of fusion is attributed to the elimination of micromotion at the fusion site because of the increased rigidity of the triangular external compression frame.

The right atrium and the right ventricle of fifty-five patients were imaged with transesophageal echocardiography during fifty-nine total knee arthroplasties performed with cement and the use of general anesthesia. The patients ranged in age from thirty-two to eighty-three years (mean, 65.5 years). Cardiopulmonary parameters were measured with use of hemodynamic monitoring systems, such as pulse oximeters, pulmonary artery catheters, and radial artery catheters. In addition, a femoral vein catheter was inserted on the side of the operation in ten of the fifty-five patients. Showers of echogenic material traversing the right atrium, the right ventricle, and the pulmonary artery after the tourniquet was deflated were observed to various degrees in all patients and lasted three to fifteen minutes. The mean peak intensity occurred within thirty seconds (range, twenty-four to forty-five seconds) after the tourniquet was released. The mean mixed venous oxygen saturation (and standard error of the mean) decreased (from 83+/-0.9 to 72+/-1.5 per cent) and the mean pulmonary arterial pressure increased (from 20+/-1.0 to 27+/-1.0 millimeters of mercury [2.67+/-0.13 to 3.60+/-0.13 kilopascals]), compared with the values before the tourniquet was released, in all patients. The pulmonary vascular resistance index increased after release of the tourniquet (to a maximum of 328+/-29 dyne.s.cm(-5).m2; p = 0.00002) only in the patients who had echogenic material that was at least 0.5 centimeter in diameter. Clinical pulmonary embolism developed postoperatively in three patients; all three had had echogenic particles that were more than 0.5 centimeter in maximum diameter on imaging. Blood aspirated from one of the pulmonary artery catheters and from five of the ten femoral vein catheters demonstrated fresh venous thrombus. Histological evaluation of the aspirates failed to demonstrate fat, marrow, or particles of polymethylmethacrylate. Surgeons should consider acute pulmonary embolism as a diagnosis when evaluating a patient who has hemodynamic collapse during total knee arthroplasty performed with cement.

If the physician is aware of this diagnosis and maintains an appropriate level of suspicion and low threshold to commence duplex evaluation. The potential morbidity of a fracture-induced traumatic pseudoaneurysm can be minimized.

Although total knee arthroplasty (TKA) has been studied extensively, objective muscle testing has not been reported. Isokinetic testing of 68 patients with degenerative joint disease scheduled for unilateral TKA revealed that marked muscular deficits in flexion and extension were present preoperatively in the involved knee. Postoperatively, hamstring peak-torque values were able to attain strength levels of the uninvolved knee within the period of seven to 12 months after surgery, whereas the quadriceps mechanism still showed a residual deficit at two years follow-up evaluation. In addition, the ratio of flexion to extension peak torques in the operated knee returned to normal values as the quadriceps mechanism was rehabilitated. A comprehensive evaluation system consisting of Cybex II isokinetic testing, gait mat analysis, and the Hospital for Special Surgery knee rating scale is also presented. Isokinetic testing correlated well with gait analysis. Patients with a nearly balanced quadriceps-to-hamstring ratio walked with a more symmetrical gait pattern. The knee rating scale was less reliable in assessing functional outcome. Functional testing and evaluation at the authors' institution has provided an important source of objective information that allows better planning and evaluation of TKAs. These isokinetic studies enable more critical planning of the rehabilitation program. Hamstring or quadricep exercises may be emphasized as required. The authors conclude that a balanced hamstring to quadriceps mechanism is needed for resumption of normal gait.

Chemically synthesized dimers, trimers and tetramers of 15-dehydroprostaglandin B1 and 16,16'-dimethyl-15-dehydroprostaglandin B1 facilitate the release of Ca2+ from isolated rat liver mitochondria. The parent monomeric prostaglandins had no significant activity. The rate of release was stimulated by exogenous K+ or Na+, suggesting an antiport exchange of monovalent cations for intra-mitochondrial Ca2+. The activity depended upon the presence of ruthenium red, which prevented recycling of Ca2+; comparison of the activity with A23187 and carbonyl cyanide p-trifluoromethoxyphenylhydrazone indicated that the prostaglandin B1 oligomers were functioning as ionophores and the release of Ca2+ was not caused by an uncoupling of oxidative phosphorylation. The oligomers caused a major decrease in the membrane potential but only when the mitochondria were preloaded with exogenous Ca2+, and even then, the Ca2+ efflux was completed before the membrane potential decreased to less than 90 mV. The oligomeric molecules were able to form supramolecular aggregates in the presence of Ca2+ as detected by light scattering. They extracted Ca2+ into an organic phase, and translocated Ca2+ from one aqueous domain to another across an organic barrier; K+ and Na+ modulated these processes. The prostaglandin B1 derivatives also translocated Rb+ from one aqueous phase to another across an organic barrier when Ca2+ was translocated.

Using a gait mat, we characterized the functional results for thirty-five patients before and after a total knee replacement for the treatment of degenerative arthritis. Preoperatively, we studied three distinct populations of patients. Group I consisted of sixteen patients who were scheduled to have a unilateral total knee replacement and who had no signs or symptoms of arthritis in the contralateral knee. Group II consisted of twelve patients who were scheduled to have a unilateral total knee replacement but who had asymptomatic degenerative arthritis in the contralateral knee. Group III consisted of seven patients who had bilateral arthritis that was to be managed by total knee replacement. The gait mat allowed us to measure stance time, step length, double-support time, swing time, swing-to-stance ratio, and velocity. A knee-rating scale was used to measure pain. The data were compared with those obtained from an age-matched control group of ninety-one subjects. Postoperatively, the gait evaluation revealed marked improvement in all of the patients. However, the patients in Group II did not improve as much as those in Groups I and III did. We concluded that even asymptomatic arthritis can impair gait, that bilateral total knee replacement can yield excellent results, and that patients tend to use the lower limbs in as symmetrical a way as possible. Gait analysis can be an important source of objective information, and it is easily performed by using a gait mat.