Blockchain Applications in the Pharmaceutical Industry.

Methods: We utilized a 4D framework using ease of implementation, novelty, necessity, and fit of the overall industry to examine the adoption of blockchain technology in the pharmaceutical industry. Based on the 2D framework of difficulty and novelty as driving factors for the development of foundational technologies in the world of business by Iansiti and Lakhani, each application was ranked and scored for the best potential implementation. The potential applications proposed in this paper can be grouped into two main categories. The first category, management, includes best-use cases, such as health records, clinical trials, and inventory systems. The second category, monitoring, highlights cases, such as pharmaceutical products, preventing counterfeits, optimizing supply chains, and addressing prescription misuse and abuse. Results: Each application was ranked by the four metrics in the framework, giving the greatest weight to necessity and ease of implementation. Using the highlighted methodology earlier, the applications for best implementation include Prescription Drug Misuse and Abuse Prevention, Prevention of Counterfeits, Clinical Trial Outcomes, and Smart Contracts. Conclusion: Blockchain technology offers a new and promising solution to the pharmaceutical industry's needs. To promote the most appropriate use, each application of blockchain technology must fit within the framework of necessity, ease of implementation, familiarity amongst stakeholders, and fit of the overall industry. By using the extended framework proposed by Iansiti and Lakhani, we show how blockchain, in all these domains, shows promise to improve pharmaceutical industry performance.

Do Patients Want to Be Involved in Their Carpal Tunnel Surgery Decisions? A Multicenter Study.

PURPOSE: Carpal tunnel syndrome requires multiple decisions during its management, including regarding preoperative studies, surgical technique, and postoperative wound management. Whether patients have varying preferences for the degree to which they share in decisions during different phases of care has not been explored. The goal of our study was to evaluate the degree to which patients want to be involved along the care pathway in the management of carpal tunnel syndrome. METHODS: We performed a prospective, multicenter study of patients undergoing carpal tunnel surgery at 5 academic medical centers. Patients received a 27-item questionnaire to rate their preferred level of involvement for decisions made during 3 phases of care for carpal tunnel surgery: preoperative, intraoperative, and postoperative. Preferences for participation were quantified using the Control Preferences Scale. These questions were scored on a scale of 0 to 4, with patient-only decisions scoring 0, semiactive decisions scoring 1, equally collaborative decisions scoring 2, semipassive decisions scoring 3, and physician-only decisions scoring 4. Descriptive statistics were calculated. RESULTS: Seventy-one patients completed the survey between November 2018 and April 2019. Overall, patients preferred semipassive decisions in all phases of care (median score, 3). Patients preferred equally collaborative decisions for preoperative decisions (median score, 2). Patients preferred a semipassive decision-making role for intraoperative and postoperative decisions (median score, 3), suggesting these did not need to be equally shared. CONCLUSIONS: Patients with carpal tunnel syndrome prefer varying degrees of involvement in the decision-making process of their care and prefer a semipassive role in intraoperative and postoperative decisions. CLINICAL RELEVANCE: Strategies to engage patients to varying degrees for all decisions during the management of carpal tunnel syndrome, such as decision aids for preoperative surgical decisions and educational handouts for intraoperative decisions, may facilitate aligning decisions with patient preferences for shared decision-making.

Clinical and Patient-Reported Outcomes After Hybrid Russe Procedure for Scaphoid Nonunion.

Background: Hybrid Russe technique for the treatment of scaphoid nonunion with humpback deformity has been described with a reported 100% union rate. We sought to evaluate the reproducibility of this technique. Methods: We completed a retrospective chart review of patients with a scaphoid waist nonunion and humpback deformity treated with the hybrid Russe technique from 2015 to 2019 with a minimum of 3-month follow-up. Twenty patients with 21 nonunions were included (mean follow-up: 7.0 months). Scapholunate angle was the primary outcome measure. Secondary outcomes included: intrascaphoid angle, radiolunate angle, pain on the visual analog scale (VAS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score. Other variables included: time to computed tomography (CT) union, range of motion, and complications. Descriptive statistics were presented. Pre- and postoperative angles, VAS, and QuickDASH scores were evaluated with Wilcoxon signed rank tests. Results: The mean scapholunate angle improved -17.6° ± 6.4°. The mean intrascaphoid angle improved 28.2° ± 6.3°. The mean radiolunate angle improved 12.8° ± 8.8°. Of the 21 scaphoids, 20 (95%) demonstrated union on a CT scan. One patient was diagnosed with a nonunion. In total, 90% of patients noted symmetric range of motion compared with the contralateral side. The mean VAS pain score improved 6 ± 3 points. The mean QuickDASH score improved 10 ± 8 points. Complications (aside from nonunion) included 1 patient with persistent wrist pain that resolved with removal of hardware. Conclusions: The hybrid Russe technique for the treatment of scaphoid nonunions with humpback deformity demonstrates a 95% union rate. This technique is effective, reproducible, and may serve as an alternative to techniques that include structural grafts from distant sites.

Outcomes of Supplementary Spring Wire Fixation With Volar Plating for Volar Lunate Facet Fragments in Distal Radius Fractures.

BACKGROUND: Intra-articular distal radius fractures with small volar lunate facet fragments can be challenging to address with volar plate fixation alone. Volar locked plating with supplementary spring wire fixation has been previously described in a small series but has not been further described in the literature. We hypothesized that this technique can provide adequate fixation for volar lunate facet fragments smaller than 15 mm in length, which are at risk of displacement. METHODS: We completed a retrospective chart review (2015-2019) of patients who underwent volar locked plating with the addition of supplementary spring wire fixation for intra-articular distal radius fractures with a volar lunate facet fragment (<15 mm). Postoperative radiographs were assessed to evaluate union, evidence of hardware failure, escape of the volar lunate facet fragment, and postoperative volar tilt. Clinical outcome was assessed with wrist flexion/extension, arc of pronosupination, and Quick Disabilities of the Arm, Shoulder, and Hand Score (QuickDASH) scores. RESULTS: Fifteen patients were identified, of which all went on to fracture union. There were no hardware failures or escape of the volar lunate facet fragment at final follow-up. One patient underwent hardware removal for symptoms of flexor tendon irritation. The mean wrist flexion was 59°, wrist extension was 70°, pronation was 81°, and supination was 76°. The mean QuickDASH score was 18.5. The mean postoperative volar tilt was 3.6°. CONCLUSIONS: Supplementary spring wire fixation with standard volar plating provides stable fixation for lunate facet fragments less than 15 mm. This technique is a safe and reliable alternative to commercially available fragment-specific implants.

Outcome Metrics in the Treatment of Distal Radius Fractures in Patients Aged Above 50 Years: A Systematic Review.

BACKGROUND: The inclusion of patient-reported outcome measures (PROMs) serves to better quantify aspects of patient outcomes missed with objective measures, including radiographic indices and physical examination findings. We hypothesize that PROMs are inconsistently and heterogeneously captured in the treatment of distal radius fractures. METHODS: We performed a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines of all level I and II randomized controlled trials (RCTs) of distal radius fracture treatment of any modality for those older than 50 years of age from January 2008 to January 2018. A total of 23 studies were included in the final analysis. The metrics used by each study to assess outcomes were collected, compared, and described. RESULTS: Physical examination findings and radiographic measures were reported in 70% and 74% of studies, respectively. Patient-reported outcomes measures were used to assess outcomes in 74% of studies. Only the Disabilities of the Arm, Shoulder, and Hand was used in greater than half of the studies (57%). Pain scores were assessed in 39% of studies and complications in only 26%. CONCLUSIONS: There is substantial heterogeneity and lack of standardization in the collection of both objective outcome measures and PROMs in level I and II RCTs for the treatment of distal radius fractures. The ability to compare between studies or aggregate data among studies is therefore limited. Radiographic and physical examination findings remain frequently reported despite known limitations of these metrics. The routine collection of PROMs after the treatment of distal radius fractures can ensure care is directed toward improving what is most important to patients.

The Impact of Certificate of Need Status on the Utilization and Reimbursement of Open and Endoscopic Carpal Tunnel Release.

A certificate of need (CON) permits a healthcare organization to build new facilities only if significant medical needs exist. Many states have implemented CON programs to prevent procedure overutilization and price inflation. We hypothesized that there are no differences in reimbursement or utilization for open and endoscopic carpal tunnel release (CTR) when comparing states with and without CON programs. We queried a private-payer database to identify open and endoscopic CTRs performed between 2007 and 2015. In total, 82,689 CTRs were identified: 70,160 open, 12,529 endoscopic. Reimbursement increased for open procedures (compound annual growth rate [CAGR] 1.0% CON, 1.4% non-CON) but only marginally increased or decreased in the endoscopic group (CAGR -0.8% CON, 0.2% non-CON). Utilization increased across all settings, and was highest in the endoscopic CON group (CAGR 17.9%). Least growth was seen in the open non-CON group (CAGR 10.0%). Overall, CON programs may not actually decrease CTR spending or utilization. (Journal of Surgical Orthopaedic Advances 30(2):090-092, 2021).

A Qualitative Study of Patient Themes for the Quality of the Total Joint Arthroplasty Experience.

Patients have limited involvement in the development of quality measures that address the experience of undergoing total joint arthroplasty (TJA). Current quality measures may not fully assess the aspects of care that are important to patients. The goal of this study was to understand quality of care in TJA from the patient perspective by exploring patients' knowledge gaps, experiences, and goals. The authors completed a prospective qualitative analysis of patients who had undergone hip or knee TJA. Patients completed an open-ended, structured questionnaire about the surgical and recovery process as it relates to quality of care. The authors used a phenomenologic approach and purposeful sampling to enroll 74 patients 6 to 8 weeks after TJA. Responses underwent thematic analysis. Codes were used to identify themes that were important to patients in quality of care in TJA. The authors identified 3 themes: (1) returning to activity without pain or complication, which included psychological, functional, and complication-related goals; (2) negotiating the physical and psychological challenges of recovery, which encompassed the need for assistance from the caregiver as well as psychological and physical barriers to recovery; and (3) being prepared and informed for the process of surgery, including physical, logistical, and psychological preparation. Both patients and health systems may benefit from efforts to address these patient-centered themes of quality care through quality measures for TJA (eg, improving the psychological challenges of recovery). Future quality measures, such as assessment of patient experience, may be made more patient centered if they measure and improve aspects of care that matter to patients. [Orthopedics. 2021;44(2):117-122.].

Engaging Patients to Ask More Questions: What's the Best Way? A Pragmatic Randomized Controlled Trial.

PURPOSE: Hand conditions are common, and often require a discussion of the tradeoffs of different treatment options. Our goal was to evaluate whether providing patients with a Question Prompt List (QPL) for common hand conditions improves their perceived involvement in care compared with providing patients with 3 generic questions. METHODS: We performed a prospective, single-center, pragmatic randomized controlled trial. We created a QPL pamphlet for patients with common hand conditions. New patients with common hand conditions were enrolled between April 2019 and July 2019 and were randomized into either the QPL group (with 35 hand-specific questions) or the AskShareKnow group (3 generic questions: [1] What are my options? [2] What are the possible benefits and harms of those options? [3] How likely are each of these benefit and harms to happen to me?). Both groups received the questions prior to meeting with their surgeon. We used the Perceived Involvement in Care Scale (PICS), a validated instrument designed to evaluate patient participation in decision-making, as our primary outcome. The maximum PICS score is 13, and a higher score indicates higher perceived involvement. RESULTS: One hundred twenty-six patients participated in the study, with 63 patients in the QPL group and 63 patients in the AskShareKnow group. The demographic characteristics were similar in the 2 groups. The mean AskShareKnow group PICS score was 8.3 ± 2.2 and the mean QPL PICS score was 7.5 ± 2.8, which was not deemed clinically significant. CONCLUSIONS: The QPLs do not increase perceived involvement in care in patients with hand conditions compared with providing patients with 3 generic questions. CLINICAL RELEVANCE: Various approaches have been evaluated to help improve patient involvement in their care. In hand surgery, 3 generic questions were no different than a lengthy QPL with respect to patient involvement in their care.

The Patient Perspective on Patient-Reported Outcome Measures Following Elective Hand Surgery: A Convergent Mixed-Methods Analysis.

PURPOSE: Patient-reported outcome measures (PROMs) have traditionally been used for research purposes, but are now being used to evaluate outcomes from the patient's perspective and inform ongoing management and quality of care. We used quantitative and qualitative approaches to evaluate the short-version Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and the Patient-Specific Functional Scale (PSFS) with regard to patient preference and measurement of patient goals and their responsiveness after treatment. METHODS: Patients 18 years or older undergoing elective hand surgery received the QuickDASH and PSFS questionnaires before and at 6 weeks after surgery. Two additional questions intended to elicit patients' preferences regarding the QuickDASH and PSFS were included. Responsiveness was measured by change in pre- to postoperative score. We analyzed patients' responses to the 2 additional questions to identify themes in PROM preferences. Results from the quantitative and qualitative analyses were combined into a convergent mixed-methods (eg, quantitative and qualitative) analysis. RESULTS: Thirty-eight patients completed preoperative questionnaires; 25 (66%) completed postoperative questionnaires. Seventeen patients (77%) preferred the PSFS, 3 (14%) had no preference, 2 (9%) preferred the QuickDASH. The average change from pre- to postoperative QuickDASH was -10 (SD, 20), and that of the PSFS was -27 (SD, 26). Ten patients (40%) reported QuickDASH score changes above the minimal clinically importance difference (MCID), 17 patients (68%) reported PSFS score changes above the MCID. Content analysis revealed 4 themes in preference for a PROM: instrument simplicity (ease of instrument understanding and completion), personalized assessment (individualization and relevance), goal directed (having measurable aims or objectives), distinct items (concrete or specific instrument items or functions). CONCLUSIONS: Most patients felt the PSFS better measured their goals because it is a simple, personalized instrument with distinct domains. CLINICAL RELEVANCE: Whereas standardized PROMs may better compare across populations, physicians, or conditions, employing PROMs that address patient-specific goals may better assess aspects of care most important to patients. A combination of these 2 types of PROMs can be used to assess outcomes and inform quality of care.

Financial Distress Is Associated With Delay in Seeking Care for Hand Conditions.

Background: As medical costs continue to rise, financial distress due to these costs has led to poorer health outcomes and patient cost-coping behavior. Here, we test the null hypothesis that financial distress is not associated with delay of seeking care for hand conditions. Methods: Eighty-seven new patients presenting to the hand clinic for nontraumatic conditions completed our study. Patients completed validated instruments for measuring financial distress, pain catastrophizing, and pain. Questions regarding delay of care were included. The primary outcome was self-reported delay of the current hand clinic visit. Results: Patients who experience high financial distress differed significantly from those who experience low financial distress with respect to age, race, annual household income, and employment status. Those experiencing high financial distress were more likely to report having delayed their visit to the hand clinic (57% vs 30%), higher pain catastrophizing scores (17.7 vs 7.6), and higher average pain in the preceding week (4.5 vs 2.3). After adjusting for age, sex, and pain, high financial distress (adjusted odds ratio [OR] = 4.90) and pain catastrophizing score (adjusted OR = 0.96) were found to be independent predictors of delay. Financial distress was highly associated with annual household income in a multivariable linear regression model. Conclusions: Patients with nontraumatic hand conditions who experience higher financial distress are more likely to delay their visit to the hand clinic. Within health care systems, identification of patients with high financial distress and targeted interventions (eg, social or financial services) may help prevent unnecessary delays in care.

Development and Testing of a Question Prompt List for Common Hand Conditions: An Exploratory Sequential Mixed-Methods Study.

PURPOSE: A question prompt list (QPL) is a tool that lists possible questions a patient may want to ask their surgeon. Its purpose is to improve patient-physician communication and increase patient engagement. Although QPLs have been developed in other specialties, one does not exist for hand conditions. We sought to develop a QPL for use in the hand surgery clinic using a mixed-methods design. METHODS: We drafted a QPL based on prior work outside of hand surgery and then used an exploratory sequential mixed-methods design (both qualitative and quantitative methods) to finalize the QPL. Qualitative evaluation included both a written questionnaire completed by a patient advisory board, hand therapists, and hand surgeons, as well as cognitive interviews conducted with clinic patients using the tool. Revisions to the QPL were made after each phase of qualitative analysis. The final QPL was then evaluated quantitatively using the system usability score (SUS) questionnaire to assess its usability. RESULTS: A patient advisory board consisting of 6 patients, 5 hand therapists, and 6 hand surgeons completed the written questionnaire. Thirteen patients completed a cognitive interview of the QPL. We completed a content analysis of the qualitative data and incorporated the findings into the QPL. Twenty patients then reviewed the final QPL pamphlet and completed the SUS questionnaire. The resulting SUS score of 78.8 indicated above-average usability of the QPL tool. CONCLUSIONS: The QPL developed in this study, from the perspective of multiple stakeholders, provides a usable tool to engage and prompt patients in asking questions during their visit with their hand surgeon with the potential to improve communication and patient-centered care. CLINICAL RELEVANCE: This study provides clinicians with a QPL developed for use in the hand surgery clinic setting, aimed at facilitating more thorough patient-provider discussion.

Performance Metrics in Hand Surgery: Turning a Blind Eye Will Cost You.

The Medicare Access and Children's Health Insurance Program Reauthorization Act established the Quality Payment Program (QPP), which mandates that physicians who meet the threshold in volume of Medicare patients for whom they care participate in this program through either advanced Alternative Payment Models or the Merit-Based Incentive Payment System. Anticipating physicians' concerns regarding the burden of implementing the QPP, feedback from physicians became a critical component of the continued implementation process in 2018. The purpose of this review is to inform hand surgeons regarding the current QPP (early 2019) and for future observation periods.

Epidural Hematoma Following Cervical Spine Surgery.

STUDY DESIGN: A multicentered retrospective case series. OBJECTIVE: To determine the incidence and circumstances surrounding the development of a symptomatic postoperative epidural hematoma in the cervical spine. METHODS: Patients who underwent cervical spine surgery between January 1, 2005, and December 31, 2011, at 23 institutions were reviewed, and all patients who developed an epidural hematoma were identified. RESULTS: A total of 16 582 cervical spine surgeries were identified, and 15 patients developed a postoperative epidural hematoma, for a total incidence of 0.090%. Substantial variation between institutions was noted, with 11 sites reporting no epidural hematomas, and 1 site reporting an incidence of 0.76%. All patients initially presented with a neurologic deficit. Nine patients had complete resolution of the neurologic deficit after hematoma evacuation; however 2 of the 3 patients (66%) who had a delay in the diagnosis of the epidural hematoma had residual neurologic deficits compared to only 4 of the 12 patients (33%) who had no delay in the diagnosis or treatment (P = .53). Additionally, the patients who experienced a postoperative epidural hematoma did not experience any significant improvement in health-related quality-of-life metrics as a result of the index procedure at final follow-up evaluation. CONCLUSION: This is the largest series to date to analyze the incidence of an epidural hematoma following cervical spine surgery, and this study suggest that an epidural hematoma occurs in approximately 1 out of 1000 cervical spine surgeries. Prompt diagnosis and treatment may improve the chance of making a complete neurologic recovery, but patients who develop this complication do not show improvements in the health-related quality-of-life measurements.

Intraoperative Death During Cervical Spinal Surgery: A Retrospective Multicenter Study.

STUDY DESIGN: A retrospective multicenter study. OBJECTIVE: Routine cervical spine surgeries are typically associated with low complication rates, but serious complications can occur. Intraoperative death is a very rare complication and there is no literature on its incidence. The purpose of this study was to determine the intraoperative mortality rates and associated risk factors in patients undergoing cervical spine surgery. METHODS: Twenty-one surgical centers from the AOSpine North America Clinical Research Network participated in the study. Medical records of patients who received cervical spine surgery from January 1, 2005, to December 31, 2011, were reviewed to identify occurrence of intraoperative death. RESULTS: A total of 258 patients across 21 centers met the inclusion criteria. Most of the surgeries were done using the anterior approach (53.9%), followed by posterior (39.1%) and circumferential (7%). Average patient age was 57.1 ± 13.2 years, and there were more male patients (54.7% male and 45.3% female). There was no case of intraoperative death. CONCLUSIONS: Death during cervical spine surgery is a very rare complication. In our multicenter study, there was a 0% mortality rate. Using an adequate surgical approach for patient diagnosis and comorbidities may be the reason how the occurrence of this catastrophic adverse event was prevented in our patient population.

C5 Palsy After Cervical Spine Surgery: A Multicenter Retrospective Review of 59 Cases.

STUDY DESIGN: A multicenter, retrospective review of C5 palsy after cervical spine surgery. OBJECTIVE: Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery. METHODS: We conducted a multicenter, retrospective review of 13 946 patients across 21 centers who received cervical spine surgery (levels C2 to C7) between January 1, 2005, and December 31, 2011, inclusive. P values were calculated using 2-sample t test for continuous variables and χ2 tests or Fisher exact tests for categorical variables. RESULTS: Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%). CONCLUSION: C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date.

Complications Related to the Recombinant Human Bone Morphogenetic Protein 2 Use in Posterior Cervical Fusion.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: To compare the complications between posterior cervical fusions with and without recombinant human bone morphogenetic protein 2 (rhBMP2). SUMMARY OF BACKGROUND DATA: Use of rhBMP2 in anterior cervical spinal fusion procedures can lead to potential complications such as neck edema, resulting in airway complications or neurological compression. However, there are no data on the complications associated with the "off-label" use of rhBMP2 in upper and lower posterior cervical fusion approaches. MATERIALS AND METHODS: Patients from the PearlDiver database who had a posterior cervical fusion between 2005 and 2011 were identified. We evaluated complications within 90 days after fusion and data was divided in 2 groups: (1) posterior cervical fusion including upper cervical spine O-C2 (upper group) and (2) posterior cervical fusion including lower cervical spine C3-C7 (lower group). Complications were divided into: any complication, neck-related complications, wound-related complications, and other complications. RESULTS: Of the 352 patients in the upper group, 73 patients (20.7%) received rhBMP2, and 279 patients (79.3%) did not. Likewise, in the lower group of 2372 patients, 378 patients (15.9%) had surgery with rhBMP2 and 1994 patients (84.1%) without. In the upper group, complications were observed in 7 patients (9.6%) with and 34 patients (12%) without rhBMP2. In the lower group, complications were observed in 42 patients (11%) with and 276 patients (14%) without rhBMP2. Furthermore, in the lower group the wound-related complications were significantly higher in the rhBMP2 group (23 patients, 6.1%) compared with the non-rhBMP2 group (75 patients, 3.8%). CONCLUSIONS: Our data showed that the use of rhBMP2 does not increase the risk of complications in upper cervical spine fusion procedures. However, in the lower cervical spine, rhBMP2 may elevate the risk of wound-related complications. Overall, there were no major complications associated with the use of rhBMP2 for posterior cervical fusion approaches. LEVEL OF EVIDENCE: Level III.

Dynamic Evaluation of the Cervical Spine and the Spinal Cord of Symptomatic Patients Using a Kinetic Magnetic Resonance Imaging Technique.

PURPOSE: The purpose of this study was to examine the movement of the spinal cord and its relationship to the spinal canal in patients with mild spondylosis using kinetic magnetic resonance imaging (kMRI). METHODS: Weight-bearing, multiposition kMRI was performed on symptomatic patients through a full range of flexion-extension. A total of 52 study patients were selected based on the C2-C7 Cobb angle of sagittal alignment: lordotic (from 30 to 45 degrees). We evaluated dynamic changes in different parameters from flexion-extension: spinal canal diameter (CD), spinal cord diameter (SCD), space available for the cord, anterior space available for the cord (ASAC), posterior space available for the cord (PSAC), average distance between the anterior canal and the cord (d-value), and global angle for the spinal canal and cord. RESULTS: The CD tended to decrease from flexion to extension from C3/C4 to C6/C7, however, there were no significant differences at the proximal and distal levels, C2/C3 and C7/T1. There were no significant differences of SCD between different postures. The SCD tended to decrease from C2/C3 to C7/T1. The ASAC followed the same pattern as CD-values. The ASAC was narrowest at C4/C5 and C5/C6. The PSAC tended to increase from C2/C3 to C7/T1. The spinal cord shifted anteriorly with extension and posteriorly with flexion. In addition, the spinal cord maintained its curve with the movement. CONCLUSIONS: The kinematics of spinal cord motion may be associated with the pathogenesis of cervical spondylotic myelopathy. However, the spinal cord maintains its curve with position changes. Consequently, different motions of the cervical spine may affect spinal cord migration and cause changes in ASAC and PSAC.

The osteon: the micromechanical unit of compact bone.

The research techniques available for investigation of secondary osteons in human bone enable establishment of their biological composition and quantification of their mechanical properties. Further, the data generated through current research techniques facilitate studies on the significance of osteons in normal and pathological conditions, including via multi-scale modeling conducted with a view of building realistic models of virtual bone, suitable for applications from orthopaedic challenges to endocrine disorders. The understanding of the biomechanical function of the osteon requires clarification of the molecular-cellular processes that form, maintain and remodel the osteon and affect the mechanical function. In turn, the mechanical function affects the biology of the osteon. In retrospective, the investigation of osteons has focused on the unraveling of the complex combination of elementary components to discern the major factors that define the mechanical behavior. The micro-structural environment that leads to macroscopic fracture remains unclear. Arrangement, distribution and quality of the elementary components may participate in fracture risk. The latest results underline the fundamental role of the orientation of collagen type I and of carbonated hydroxyapatite crystallites.