John C. Elfar

Nerve Physiology: Mechanisms of Injury and Recovery

Peripheral nerve injuries are common conditions, with broad-ranging groups of symptoms depending on the severity and nerves involved. Although much knowledge exists on the mechanisms of injury and regeneration, reliable treatments that ensure full functional recovery are scarce. This review aims to summarize various ways these injuries are classified in light of decades of research on peripheral nerve injury and regeneration.

Erythropoietin accelerates functional recovery after peripheral nerve injury.

BACKGROUND Erythropoietin is a naturally occurring hormone with multiple effects on a number of different cell types. Recent data have suggested neuroprotective and perhaps even neurotrophic roles for erythropoietin. We hypothesized that these functional effects could be demonstrable in standard models of peripheral nerve injury. METHODS Experiments were undertaken to evaluate the effect of erythropoietin on the previously reported standard course of healing of sciatic injuries in mice. The injury groups included mice that were subjected to (1) sham surgery, (2) a calibrated sciatic crush injury, (3) transection of the sciatic nerve followed by epineural repair, or (4) a transection followed by burial of the proximal stump in the adjacent muscle tissue (neurectomy). Either erythropoietin or saline solution was administered to the mice in each of these experimental groups twenty-four hours preinjury, immediately after surgical creation of the injury, twenty-four hours postinjury, or one week postinjury. All mice were evaluated on the basis of the published model for recovery of sciatic nerve motor function by measuring footprint parameters at specific times after the injury. Immunohistochemistry was also performed to assess the erythropoietin-receptor expression profile at the site of injury. RESULTS In general, the mice treated with erythropoietin recovered sciatic nerve motor function significantly faster than did the untreated controls. This conclusion was based on a sciatic function index that was 60% better in the erythropoietin-treated mice at seven days postinjury (p < 0.05). Although the group that had been given the erythropoietin immediately postinjury showed the best enhancement of recovery, the timing of the administration of the drug was not critical. Histological analysis demonstrated enhanced erythropoietin-receptor positivity in the nerves that recovered fastest, suggesting that accelerated healing correlates with expression of the receptor in nerve tissue. CONCLUSIONS Erythropoietin treatment of an acute sciatic nerve crush injury leads to an effect consistent with functional neuroprotection. This protective effect may have clinical relevance, especially since it was detectable even when erythropoietin had been administered up to one week after injury.

Non-surgical treatment of lateral epicondylitis: a systematic review of randomized controlled trials.

BackgroundNon-surgical approaches to treatment of lateral epicondylitis are numerous. The aim of this systematic review is to examine randomized, controlled trials of these treatments.MethodsNumerous databases were systematically searched from earliest records to February 2013. Search terms included “lateral epicondylitis,” “lateral elbow pain,” “tennis elbow,” “lateral epicondylalgia,” and “elbow tendinopathy” combined with “randomized controlled trial.” Two reviewers examined the literature for eligibility via article abstract and full text.ResultsFifty-eight articles met eligibility criteria: (1) a target population of patients with symptoms of lateral epicondylitis; (2) evaluation of treatment of lateral epicondylitis with the following non-surgical techniques: corticosteroid injection, injection technique, iontophoresis, botulinum toxin A injection, prolotherapy, platelet-rich plasma or autologous blood injection, bracing, physical therapy, shockwave therapy, or laser therapy; and (3) a randomized controlled trial design. Lateral epicondylitis is a condition that is usually self-limited. There may be a short-term pain relief advantage found with the application of corticosteroids, but no demonstrable long-term pain relief. Injection of botulinum toxin A and prolotherapy are superior to placebo but not to corticosteroids, and botulinum toxin A is likely to produce concomitant extensor weakness. Platelet-rich plasma or autologous blood injections have been found to be both more and less effective than corticosteroid injections. Non-invasive treatment methods such as bracing, physical therapy, and extracorporeal shockwave therapy do not appear to provide definitive benefit regarding pain relief. Some studies of low-level laser therapy show superiority to placebo whereas others do not.ConclusionsThere are multiple randomized controlled trials for non-surgical management of lateral epicondylitis, but the existing literature does not provide conclusive evidence that there is one preferred method of non-surgical treatment for this condition. Lateral epicondylitis is a condition that is usually self-limited, resolving over a 12- to 18-month period without treatment.Level of EvidenceTherapeutic Level II. See Instructions to Authors for a complete description of level of evidence.

Perilunate dislocation and perilunate fracture-dislocation.

&NA; Perilunate dislocations and perilunate fracture‐dislocations usually result from high‐energy traumatic injuries to the wrist and are associated with a characteristic spectrum of bony and ligamentous damage. Radiographic evaluation of the wrist reveals loss of normal radiocarpal and intercarpal colinearity and bony insult, which may be overlooked at the initial presentation. Prompt recognition is important to optimize outcomes. Closed reduction is performed acutely, followed by open reduction and ligamentous and bony repair with internal fixation. Complications include posttraumatic arthrosis, median nerve dysfunction, complex regional pain syndrome, tendon problems, and carpal instability. Despite appropriate treatment, loss of wrist motion and grip strength, as well as persistent pain, is common. Medium‐ and longterm studies demonstrate radiographic evidence of midcarpal and radiocarpal arthrosis, although this does not correlate with functional outcomes.

Length of hospital stay after hip fracture and risk of early mortality after discharge in New York state: retrospective cohort study.

Study question Can the length of hospital stay for hip fracture affect a patient’s risk of death 30 days after discharge? Methods In a retrospective cohort study, population based registry data from the New York Statewide Planning and Research Cooperative System (SPARCS) were used to investigate 188 208 patients admitted to hospital for hip fracture in New York state from 2000 to 2011. Patients were aged 50 years and older, and received surgical or non-surgical treatment. The main outcome measure was the mortality rate at 30 days after hospital discharge. Study answer and limitations Hospital stays of 11-14 days for hip fracture were associated with a 32% increased odds of death 30 days after discharge, compared with stays lasting one to five days (odds ratio 1.32 (95% confidence interval 1.19 to 1.47)). These odds increased to 103% for stays longer than 14 days (2.03 (1.84 to 2.24)). Other risk factors associated with early mortality included discharge to a hospice facility, older age, metastatic disease, and non-surgical management. The 30 day mortality rate after discharge was 4.5% for surgically treated patients and 10.7% for non-surgically treated patients. These findings might not be generalizable to populations in other US states or in other countries. The administrative claims data used could have been incomplete or include inaccurate coding of diagnoses and comorbid conditions. The database also did not include patient socioeconomic status, which could affect access to care to a greater extent in New York state than in European countries. Specific cause of death was not available because few autopsies are performed in this population. What this study adds By contrast with recent findings in Sweden, decreased length of hospital stay for hip fracture was associated with reduced rates of early mortality in a US cohort in New York state. This could reflect critical system differences in the treatment of hip fractures between Europe and the USA. Funding, competing interests, data sharing University of Rochester grant from the Clinical Translational Science Institute for statistical analyses used in this work (National Institutes of Health (UL1 TR000042)) and the National Institutes of Health (K-08 AR060164-01A). No competing interests declared. Data may be obtained through SPARCS at https://www.health.ny.gov/statistics/sparcs/access/.

Measurement scales in clinical research of the upper extremity, part 2: outcome measures in studies of the hand/wrist and shoulder/elbow.

Part 1 of this article outlined the basic characteristics of useful clinical measurement instruments and described scales used to measure general health, pain, and patient satisfaction. Part 2 describes the features of some of the scales most commonly used in clinical research in the hand, wrist, elbow, and shoulder.

National trends in the management of central cord syndrome: an analysis of 16,134 patients

BACKGROUND CONTEXT Central cord syndrome (CCS) is a common cause of incomplete spinal cord injury. However, to date, national trends in the management and mortality after CCS are not fully understood. PURPOSE To analyze how patient, surgical, and institutional factors influence surgical management and mortality after CCS. STUDY DESIGN A retrospective cohort analysis. PATIENT SAMPLE The Nationwide Inpatient Sample (NIS) was queried for records of patients with a diagnosis of CCS from 2003 to 2010. OUTCOME MEASURES They included in hospital mortality and surgical management, including anterior cervical decompression and fusion (ACDF), posterior cervical decompression and fusion (PCDF), and posterior cervical decompression (PCD). METHODS Using International Classification of Diseases, Ninth Revision, Clinical Modification codes, patient records with a diagnosis of CCS from 2003 to 2010 were selected from the NIS database and sorted by inpatient mortality and surgical management. Demographic information (age, gender, and race) and hospital characteristics were evaluated with χ(2)-tests for categorical variables and t tests for continuous variables. Multivariate logistic regression models controlled for confounding. RESULTS In this sample of 16,134 patients, a total of 39.7% of patients (6,351) underwent surgery. ACDF was most common (19.4%), followed by PCDF (7.4%) and PCD (6.8%). From 2003 to 2010, surgical management increased by an average of 40% each year. The overall inpatient mortality rate was 2.6%. Increasing age and comorbidities were associated with higher rates of patient mortality and a decreasing surgical rate (p<.01). Hospitals greater than 249 beds (p<.01) and the south (p<.01) were associated with a higher surgical rate. Rural hospitals (p<.01) and people in the second income quartile (p<.01) were associated with higher inpatient mortality. CONCLUSIONS Elderly patients with medical comorbidities are associated with a lower surgical rate and a higher mortality rate. Surgical management was more prevalent in the south and large hospitals. Mortality was higher in rural hospitals. It is important for surgeons to understand how patient, surgical, and institutional factors influence surgical management and mortality.

Fracture-dislocations of the proximal interphalangeal joint.

&NA; Fracture‐dislocations of the proximal interphalangeal joint encompass a spectrum of injury severity, ranging from injuries that require little intervention to those that require advanced reconstructive surgery for optimal outcome. Three fracture‐dislocation patterns are recognized: dorsal, volar, and pilon. Acceptable outcome is dependent on achieving and maintaining a well‐aligned and well‐reduced joint, re‐establishing normal joint kinematics, and restoring motion. Anatomic articular surface reduction is desirable but not absolutely necessary for a good outcome. Treatment depends on both the type of injury and patient‐dependent factors. Optimal outcome for a specific injury is predicated on expedient diagnosis and recognition of injury severity, which enables initiation of appropriate management.

Individual finger sensibility in carpal tunnel syndrome.

PURPOSE Sensibility testing plays a role in the diagnosis of carpal tunnel syndrome (CTS). No single physical examination test has proven to be of critical value in the diagnosis, especially when compared with electrodiagnostic testing (EDX). The purpose of this study was to define which digits are most affected by CTS, both subjectively and with objective sensibility testing. METHODS A prospective series of 35 patients (40 hands) with EDX-positive, isolated CTS were evaluated preoperatively using 2 objective sensibility tests: static 2-point discrimination (2PD) and abbreviated Semmes-Weinstein monofilament (SWMF) testing. Detailed surveys of subjective symptoms were also collected. RESULTS Patients identified the middle finger as the most symptomatic over all others (51%). Objective 2PD results of each digit mirrored the subjective data, with higher values for the middle finger (mean 6.07 mm, (p < .0001). Values for the index finger failed to show a significant difference from the ulnar-innervated small finger. The most symptomatic finger matched 2PD results in over two thirds of patients. The SWMF testing showed similar, statistically significant results (middle > thumb > index > small). Correlations failed between EDX, symptoms, and SWMF results or 2PD in the index finger. Positive but weak correlation (p = .002, r = .42) was found between EDX and 2PD only in the middle fingers. CONCLUSIONS The middle finger is the most likely to show changes in 2PD in patients with positive EDX findings for CTS. Middle finger 2PD is best able to correlate with EDX when compared with 2PD of other digits. The SWMF testing also shows the middle digit testing as more sensitive, but this finding may be difficult to use clinically. TYPE OF STUDY/LEVEL OF EVIDENCE Diagnostic I.

Measurement scales in clinical research of the upper extremity, part 1: General principles, measures of general health, pain, and patient satisfaction

Measurement is a fundamental cornerstone in all aspects of scientific discovery, including clinical research. To be useful, measurement instruments must meet several key criteria, the most important of which are satisfactory reliability, validity, and responsiveness. Part 1 of this article reviews the general concepts of measurement instruments and describes the measurement of general health, pain, and patient satisfaction.