Botulinum Toxin A and B Improve Perfusion, Increase Flap Survival, Cause Vasodilation, and Prevent Thrombosis: A Systematic Review and Meta-analysis of Controlled Animal Studies.

BACKGROUND: A systematic review and meta-analysis of case-control animal model studies will help clarify the vascular effects of botulinum toxin (BTX). METHODS: Preferred Reporting Items of Systematic reviews and Meta-Analyses guidelines were used to identify all animal case-control studies published before September 13, 2020, evaluating the vascular effects of BTX. Primary parameters included the following: perfusion, flap survival, arterial and venous dilation, and arterial and venous thrombosis. RESULTS: Thirty-six studies with 1032 animals met the systematic review inclusion criteria. Twenty-nine studies had quantifiable data for statistical analysis. Statistically significant increases in perfusion with BTX over saline were detected within 1 day and sustained up to 8 weeks. The following represent weighted mean data from the meta-analysis. The administration of BTX has a 26% increase in both random pattern and pedicled flap survival area over controls. Botulinum toxin causes vasodilation. Botulinum toxin increases vessel diameter in arteries by 40% and in veins by 46% compared with saline controls. The administration of BTX reduces thrombosis by 85% in arteries and by 79% in veins compared with saline controls. Vascular effects were consistent across both BTX-A and BTX-B serotypes, multiple animal species, and various doses. No clear relationships between vascular effects and BTX pretreatment time were identified. CONCLUSIONS: Perivascular BTX administration intraoperatively or as a chemical delay pretreatment several days before surgery in multiple animal species and models shows multiple changes to the vascular system. Extrapolation of lessons learned from this systematic review and meta-analysis of animal models could expand research and clinical use of BTX in human vascular disease and surgery.

The Effects of Botulinum Toxin A on Pain in Ischemic Vasospasm.

PURPOSE: The purpose was to describe the impact of botulinum toxin A (BTX-A) administration in patients with ischemic vasospasm on the magnitude and timing of pain relief and subsequent effect on opioid use. The secondary purposes were to determine the role of photoplethysomgraph (PPG) testing on treatment decisions, effect on patient-reported outcomes, and additional procedures. METHODS: A retrospective analysis of patients who received BTX-A injections was performed. Botulinum toxin type A was injected subcutaneously in symptom-specific 2-level patterns. Pain, shortened version of the Disabilities of the Arm, Shoulder, and Hand (QuickDASH), and opioid use (quantified by median morphine equivalents) were recorded and the need for repeat injections or unplanned surgeries was assessed. RESULTS: All patients (n = 20 patients; 31 hands) had ischemic pain from vasospasm and failed multiple pharmacological options. Average follow-up was 10.5 months. All patients had abnormal PPG amplitude (mean, 6.43 mm) at room temperature and increased amplitude (mean, 19.55 mm) after immersion in warm water. All patients (n = 12) with a PPG amplitude increase of 4 mm or greater had clinical success. Eleven of 13 patients had a clinically relevant decrease in pain at 20 minutes after injection. Clinically significant pain relief was sustained for 3 months (visual analog scale decreased by a mean of 4). Median morphine equivalent usage view decreased from 82.5 to 0 after injection. Patient-reported disability (QuickDASH) improved from 49 before treatment to 29 and 26 at 6 weeks and 6 months after BTX-A injection, respectively. Three patients were retreated for recurrent symptoms. Four patients required unplanned secondary procedures. CONCLUSIONS: Botulinum toxin type A administration can result in rapid (within 20 minutes) and sustained pain relief for several months with a reduction in opioid prescriptions. Botulinum toxin type A administration also improved patient-reported disability for 6 months. Use of PPG testing to determine baseline perfusion deficit and capacity to improve after warm water immersion was helpful in consideration of BTX-A use. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Opioid Versus Nonopioid Analgesia After Carpal Tunnel Release: A Randomized, Prospective Study.

Background: The purpose of this investigation was to compare pain control and patient satisfaction for conventional postoperative opioid analgesia and nonopioid multimodal analgesia after elective open or endoscopic carpal tunnel release (CTR). Methods: As part of a randomized, prospective study, patients undergoing primary, elective CTR were randomized to receive either postoperative opioids or nonopioid medications as part of a multimodal pain control strategy. Patients currently taking opioids were excluded. Patients completed a postoperative pain journal and completed the shortened version of the Disabilities of the Arm, Shoulder, and Hand Questionnaire (QuickDASH), Boston Carpal Tunnel Questionnaire, Numeric Pain Rating Scale (NPRS), and satisfaction ratings at their 2-week visit. Results: A total of 68 patients were included. Preoperatively, there were no statistically significant differences between the 2 groups with respect to pain scores, coping skills, or carpal tunnel symptoms. At 2 weeks postoperatively, patients in the nonopioid group had lower average NPRS and QuickDASH scores. Patients who took opioids consumed an average of 5 pills. No patient randomized to the nonopioid group required any opioids. Patients in the nonopioid group demonstrated lower early postoperative NPRS scores. Patient satisfaction with their pain control regimen and outcome was not significantly different between the 2 groups at any time point. Conclusions: Nonopioid medications as part of a perioperative pain control strategy demonstrate improved pain scores compared with opioid medications with similar patient satisfaction and functional outcomes. Considering the risks associated with the use of opioid analgesics, we recommend against prescribing opioids after CTR, particularly in patients not currently taking narcotic medications.

Chemistry and containing: the analyst's use of unavoidable failures.

Certain patients overwhelm the analyst's capacity to contain both the patient and the analyst's own unbearable feelings. Though some such failures of containing may lead fairly quickly to self-correction and others to clinical impasse, our focus is on an in-between state in which the analyst's ability to tolerate his inevitable failures and gradually to (re)establish his containing capacities through difficult self-analytic work can lead to significant change that might not otherwise be possible. The authors argue that this internal psychological work on the analyst's part, which may require considerable time, effort, and suffering, is an important aspect of "good enough" containing. The unique chemistry generated between patient and analyst plays an important role in both establishing and maintaining this kind of productive analytic process.

A comparison of compressive force generation by plating and intramedullary nailing techniques in a transverse diaphyseal humerus fracture model.

BACKGROUND: The null hypothesis to be tested in this study is that the compression forces generated with a novel compressible intramedullary nail are not different from compression plating techniques. METHODS: A custom sensor was used to measure the compressive force at a transverse midshaft humeral sawbone osteotomy (OTA 12-A3.2) in four groups. The groups included: standard compression plating using a limited contact dynamic compression plate (LCDC) with eccentric screw placement (ED-LCDC), compression plating using an LCDC plate with an articulated tensioner and eccentric compression screw (AT-LCDC), locked humeral nail compressed using the manufacturer's long stainless steel screwdriver (T2-IMN), and locked humeral nail compressed using a short stainless steel AO screwdriver (SF-IMN). From continuous measurements recorded during osteotomy compression, the maximum force (CMax) and force at 60 seconds after the peak measurement (CMax +60) were analyzed. RESULTS: The mean CMax was 2043 N for SF-IMN, 1109 N for AT-LCDC, 799 N for T2-IMN, and 365 N for ED-LCDC. Mean CMax +60 was 1648 N for SF-IMN, 944 N for AT-LCDC, 650 N for T2-IMN, and 319 N for ED-LCDC. The difference in both CMax and CMax +60 was statistically significant between all groups (p < 0.002). CONCLUSION: A new humeral nail can generate higher compression than plating using eccentric drill holes or the articulated tensioner when used with a short stainless steel screwdriver shaft. Clinical studies are needed to analyze whether this compression could improve the union rate of humeral fractures and nonunions beyond those of standard nails.

Modes of wear after semiconstrained total elbow arthroplasty.

BACKGROUND: Osteolysis and aseptic loosening are increasingly recognized complications of total elbow arthroplasty. However, unlike the literature on total hip and knee arthroplasty, studies describing the mechanisms of these processes after total elbow arthroplasty are sparse. METHODS: Semiconstrained total elbow arthroplasty components were retrieved from sixteen elbows (fourteen patients) at either revision surgery (at a mean of five years after implantation) for mechanical failure (fifteen elbows) or postmortem examination (one elbow). In all cases, the retrieved implant was the primary implant. The patterns of damage on these components were investigated with stereomicroscopy in correlation with clinical findings, serial radiographs, and histopathological observations. RESULTS: All of the retrieved devices exhibited multiple modes of wear. Damage to the humeral and ulnar polyethylene bushings was nearly universal; twenty-seven of twenty-eight humeral bushings demonstrated asymmetrical thinning, while fifteen of sixteen ulnar bushings demonstrated elliptical plastic deformation. In addition, unintended metal-on-metal wear between bearing and nonbearing surfaces or between two nonbearing surfaces was commonly observed, typically in association with wear and deformation of the polyethylene bushings. Wear between the stem and the cement mantle was observed in most of the ulnar components. The histopathology of the periprosthetic tissues was similar in character to that observed in association with osteolysis and loosening of total hip and knee replacements, while analysis of the particulate debris revealed a preponderance of titanium alloy and polyethylene debris. Barium sulfate particles were also observed to a lesser extent. CONCLUSIONS: Multimodal wear in total elbow replacements can lead to osteolysis, aseptic loosening, and prosthetic and periprosthetic fracture necessitating revision surgery. Polyethylene wear and damage, as well as unintended metal-on-metal wear, contribute to the periprosthetic particulate burden, which is likely pathogenic in these processes.

Ultrasonic cement removal in revision arthroplasty.

Efficient and safe cement removal is critical in revision arthroplasty. Conventional manual cement removal by hand or power-driven instruments can be time-consuming, require osteotomy, and be associated with complications such as cortical perforation, fracture, or bone loss. Ultrasonic devices offer an alternative method of cement removal by converting mechanical vibrations into thermal energy, liquefying the cement. This facilitates selective cement removal, preserves bone, decreases cortical perforation risk, and eliminates the need for osteotomy. However, potential for thermal injury exists. Ultrasound basic science, mechanism of action, and clinical applications with specific emphasis on methods to limit excessive heat generation are reviewed.

Biomechanics and histology of intact and repaired digital nerves: an in vitro study.

PURPOSE: To investigate the biomechanical properties of intact and repaired cadaver digital nerves. METHODS: Ultimate tensile failure strength and stiffness were determined in 67 human cadaver digital nerves. Total nerve area, fascicular area, and nonfascicular (connective tissue) area were determined from the metacarpophalangeal to the distal interphalangeal joint in another 35 axial nerve sections to determine regional anatomic variation. Thirty-eight additional digital nerves were transected, and epineural repairs were performed using simple, interrupted sutures. Suture number (2 vs 4), gauge (8-0 vs 9-0), and purchase length (1 mm vs 2 mm) were used in various combinations, and then the repaired nerves were pulled to failure. The mechanism of repair-site failure was determined for each suture. In situ tension of the intact digital nerves was measured during passive metacarpophalangeal and proximal interphalangeal joint motion in another 19 intact digital nerves. RESULTS: There were no significant differences in failure load or stiffness with respect to the radial or ulnar nerves within a finger or between fingers. The primary tactile side of the finger tended to have a larger diameter digital nerve. Digital nerve failure was more common proximally than distally. Intact digital nerves failed at 6 N with a stiffness of 1 N/mm. Histologic analysis showed that fascicular area and total area decreased from proximal to distal, whereas the nonfascicular-to-fascicular area ratio increased. Four epineural sutures were statistically stronger than 2 sutures. Suture purchase length and gauge did not affect repair strength. The 8-0 nylon sutures failed primarily by cut-out, whereas the 9-0 sutures failed by cut-out or breakage. Repaired nerves failed at 1 to 2 N. Maximal metacarpophalangeal joint hyperextension resulted in 4 N of digital nerve tension. When the metacarpophalangeal joint was not hyperextended, proximal interphalangeal joint motion did not generate tension. CONCLUSIONS: Similar to flexor tendons, the number of suture strands crossing the repair site was the most important variable affecting digital nerve repair strength in this cadaveric model.

Osseous anatomy of the distal humerus and proximal ulna: implications for total elbow arthroplasty.

Cortical thickness and multiple intramedullary canal diameters were measured in sequential axial sections from 27 human cadavers. No age or side differences were identified. The intramedullary humeral canal shape changed along the length of the bone in both male specimens and female specimens. Anteroposterior and male minimal humeral canal diameters increased proximally from the elbow. Male and female medial-lateral humeral diameters decreased proximally from the elbow. All ulnar canal diameters decreased distally in a uniform fashion. The minimal ulnar and humeral canal diameters did not occur in either the sagittal or coronal plane. Humeral and ulnar cortical thickness did not vary within axial sections. Only ulnar cortical thickness changed between sections, decreasing distally. On the basis of these data, a cylindrical humeral stem and an ulnar stem tapering in all planes may be optimal for total elbow arthroplasty stems. The relatively thin cortices of both the humerus and the ulna predispose patients to perforation, periarticular fracture, and complications during revision arthroplasty surgery. Finally, routine frontal and lateral radiographs may overestimate minimal canal size for total elbow arthroplasty components. However, the lateral view appears to approximate the true minimal canal diameter more closely.

Thermal tissue damage caused by ultrasonic cement removal from the humerus.

BACKGROUND: Ultrasound devices can selectively remove cement during revision arthroplasty. These instruments initially were designed for the hip and knee but also have been applied to the upper extremity. We describe a patient in whom a radial nerve palsy and a pathologic humeral fracture developed after ultrasonic cement removal was performed because of an infection at the site of a total elbow arthroplasty. Biopsies of the humerus, the triceps muscle, and the radial nerve showed widespread necrosis consistent with thermal injury. METHODS: A study involving six human cadaveric specimens was conducted to measure temperature elevations in bone and adjacent soft tissue during cement removal with use of an ultrasound device with and without irrigation. RESULTS: While temperature increased only minimally during cement polymerization, ultrasonic melting and removal of cement with use of constant energy delivery led to markedly elevated temperatures in the humeral cortex, the triceps muscle, and the radial nerve. These temperatures were above the known thresholds for thermal injury and necrosis. Subsequently, strategies designed to allow for safe ultrasonic cement removal from the humerus were applied, including intermittent delivery of energy and the use of cold irrigation between probe passes. These strategies resulted in markedly lower maximum temperatures in all tissues tested. CONCLUSIONS: Temperatures in the humerus, triceps, and, most importantly, the radial nerve can reach potentially dangerous levels when ultrasound technology is used to remove cement from the humerus. We suggest intermittent cold irrigation of the humeral canal, no tourniquet use, education of surgeons with regard to proper techniques designed to limit heat generation, and consideration of exposure and protection of the radial nerve when ultrasound devices are used.

Adolescent ACL injury: treatment considerations.

Anterior cruciate ligament (ACL) injury in a skeletally immature patient presents unique treatment challenges. In many cases, conservative treatment with bracing and physical therapy fails, resulting in recurrent instability, pain, swelling, and meniscal and chondral injury. The goal of surgical reconstruction is to recreate ACL stability without causing growth plate arrest, leg-length discrepancy, or angular deformity. Patient characteristics such as skeletal age, Tanner stage, onset of menses, family member height, growth spurt, recent change in foot size, and growth charts can help the surgeon approximate the degree of skeletal maturity and aid in selecting the timing and safest type of reconstruction. Numerous surgical techniques, ranging from an extra-articular reconstruction to intra-articular graft passage without physeal violation to standard transtibial and transfemoral tunnel placement with physeal violation, have been popularized. The majority of existing studies are retrospective case series, describing a particular author's specific technique experience. This article reviews the basic science and clinical literature, presents a treatment algorithm, and provides several case studies.

Pharmacologic therapy for osteoarthritis.

Osteoarthritis is treated with a variety of pharmacologic therapies, including acetaminophen, traditional nonsteroidal anti-inflammatory drugs, cyclo-oxygenase-2 inhibitors, intra-articular steroids, viscosupplements, glucosamine, chondroitin sulfate, capsaicin, and vitamins. In this review, we describe the clinical efficacy and side effects of these pharmaceuticals. Except for vitamins, each of these therapies is effective over the short-term when compared with placebo in controlled clinical trials. Risk-benefit analysis should be considered when prescribing these medications, as side effects are relatively common, and long-term efficacy is variable. In this review, we also examine current and future research on new medications--particularly matrix metalloproteinases and inducible nitric oxide synthase inhibitors--that may modify osteoarthritis.