Lacertus syndrome: a ten year analysis of two hundred and seventy five minimally invasive surgical decompressions of median nerve entrapment at the elbow.

PURPOSE: This study aims to assess the clinical presentation and surgical outcomes of lacertus syndrome (LS) and concomitant median nerve entrapments. METHODS: A retrospective study of prospectively collected data was conducted on patients undergoing lacertus release (LR) from June 2012 to June 2021. Available DASH (Disability of the Arm Shoulder Hand questionnaire) scores and post-operative Visual Analogue Scale (VAS) of pain, numbness, subjective satisfaction with surgical outcome, and intra-operative return of strength were analyzed. RESULTS: Two-hundred-seventy-five surgical cases were identified of which 205 cases (74.5%) underwent isolated LR, and 69 cases (25.1%) concomitant lacertus and carpal tunnel release. The three most common presenting symptoms in LS patients were loss of hand strength (95.6%), loss of hand endurance/fatigue (73.3%), and forearm pain (35.4%). Numbness in the median nerve territory of the hand was found in all patients with combined LS and carpal tunnel syndrome. Quick-DASH significantly improved (pre-operative 34.4 (range 2.3-84.1) to post-operative 12.4 (range 0-62.5), p < 0.0001) as did work and activity DASH (p < 0.0001). The postoperative VAS scores were pain VAS 1.9 and numbness VAS 1.8. Eighty-eight percent of patients reported good/excellent satisfaction with the surgical outcome. Intra-operative return of strength was verified in 99.2% of cases. CONCLUSION: LS is a common median nerve compression syndrome typically presenting with loss of hand strength and hand endurance/fatigue. Minimally invasive LR immediately restores hand strength, significantly improves DASH scores, and yields positive outcomes regarding VAS pain, numbness, and subjective satisfaction with surgery in patients with proximal median nerve entrapment at a minimum six month follow-up.

Nerve entrapment as a cause of shoulder pain in the spinal cord injured patient.

INTRODUCTION: Many people with chronic spinal cord injury (SCI) develop shoulder pain, which can adversely impact transfers and independence. Yet effective treatments remain elusive. CASE PRESENTATION: This report presents two patients with tetraplegia who had long-standing shoulder pain. Our exam showed muscle weakness and point tenderness, suggestive of nerve entrapments of the radial and axillary nerves in the posterior shoulder. These nerves were surgically decompressed and post-operatively the patients' pain resolved. DISCUSSION: Shoulder nerve entrapments are uncommon but SCI patients may be at more risk due to their unique upper extremity demands. SCI providers should consider proximal nerve entrapments as a possible cause of shoulder pain.

Upper extremity nerve entrapments: the axillary and radial nerves--clinical diagnosis and surgical treatment.

BACKGROUND: Nontraumatic pain in the shoulder, arm, and hand (brachialgia) is a common complaint in the field of musculoskeletal disorders, where nerve entrapment constitutes a possible cause. The effect of nerve compression is dose-dependent; thus, a low-level compression will only result in decreased endoneurial circulation, neural edema, and a Seddon grade IV weakness, but will not be revealed in nerve conduction or magnetic resonance imaging studies. Because of technical limitations, several clinical options to diagnose compression neuropathies in the upper extremity have been proposed. These include blinded controlled studies on manual muscle testing to delineate the level of nerve compression, and the scratch collapse test to verify the level of compression. In this article, the authors describe the clinical examination and surgical techniques for diagnosing and treating entrapments of the axillary and radial nerves. METHODS: A previously published clinical triad for diagnosis of nerve compressions has been used: (1) manual muscle testing to reveal weakness in specific muscles distal to the level of nerve compression; (2) pain on compression and/or positive Tinel sign; and (3) positive scratch collapse test at the level of nerve compression. RESULTS: Detailed videos illustrate the examination techniques for diagnosing axillary entrapment in the shoulder and radial nerve entrapments in the upper arm and forearm (four levels), and the surgical techniques for each nerve release. CONCLUSION: The clinical triad of muscle testing, scratch-collapse test, and pain at the level of nerve compression provides the clinician with a clinical foundation for analyzing patients with brachialgia in a structured fashion.

Understanding stability of the distal radioulnar joint through an understanding of its anatomy.

The authors describe the anatomy of the distal radioulnar joint (DRUJ) and delineate the importance of viewing this joint as part of the whole forearm. The osseous congruity and ligamentous integrity is of essence for the stability of the DRUJ, according to the principles of tensegrity. The neuromuscular control and possible proprioceptive function of the DRUJ are also outlined.

Diagnostic accuracy of the neurological upper limb examination II: relation to symptoms of patterns of findings.

BACKGROUND: In a sample of patients in clinical occupational medicine we have demonstrated that an upper limb neurological examination can reliably identify patterns of findings suggesting upper limb focal neuropathies. This further study aimed at approaching the diagnostic accuracy of the examination. METHODS: 82 limbs were semi-quantitatively assessed by two blinded examiners (strength in 14 individual muscles, sensibility in 7 homonymous territories, and mechanosensitivity at 10 locations along nerves). Based on the topography of nerves and their muscular and sensory innervation we defined 10 neurological patterns each suggesting a localized nerve affliction. Information on complaints (pain, weakness and/or numbness/tingling) collected by others served as a reference for comparison. The relation between the presence of pattern(s) and complaints was assessed by kappa-statistics. Sensitivity, specificity, and positive/negative predictive values were calculated, and pre-test odds were compared to post-test probability. RESULTS: The two examiners identified pattern(s) suggesting focal neuropathy in 34/36 out of 38 symptomatic limbs, respectively (kappa = 0.70/0.75), with agreement in 28 limbs. Out of 44 non-symptomatic limbs the examiners agreed on absence of any pattern in 38 limbs. With concordance between the examiners with regard to the presence or absence of any pattern, the sensitivity, specificity, positive and negative predictive values were 0.73, 0.86, 0.93 and 0.90, respectively. While the pre-test odds for a limb to be symptomatic amounted to 0.46 the post-test probability was 0.81. For each examiner the post-test probability was 0.87 and 0.88, respectively. CONCLUSION: The improved diagnostic confidence is an indication of one aspect of construct validity of the physical examination. For determination of clinical feasibility of the examination further studies are required, most importantly 1) studies of validity by means of comparison with additional references and 2) studies of the potential benefit that can be attained from its use.

Diagnostic accuracy of the neurological upper limb examination I: inter-rater reproducibility of selected findings and patterns.

BACKGROUND: We have previously assessed the reproducibility of manual testing of the strength in 14 individual upper limb muscles in patients with or without upper limb complaints. This investigation aimed at additionally studying sensory disturbances, the mechanosensitivity of nerve trunks, and the occurrence of physical findings in patterns which may potentially reflect a peripheral neuropathy. The reproducibility of this part of the neurological examination has never been reported. METHODS: Two blinded examiners performed a semi-quantitative assessment of 82 upper limbs (strength in 14 individual muscles, sensibility in 7 homonymous territories, and mechanosensitivity of nerves at 10 locations). Based on the topography of nerves and their muscular and cutaneous innervation we defined 10 neurological patterns each suggesting a focal neuropathy. The individual findings and patterns identified by the two examiners were compared. RESULTS: Strength, sensibility to touch, pain and vibration, and mechanosensitivity were predominantly assessed with moderate to very good reproducibility (median kappa-values 0.54, 0.69, 0.48, 0.58, and 0.53, respectively). The reproducibility of the defined patterns was fair to excellent (median correlation coefficient = 0.75) and the overall identification of limbs with/without pattern(s) was good (kappa = 0.75). CONCLUSION: This first part of a study on diagnostic accuracy of a selective neurological examination has demonstrated a promising inter-rater reproducibility of individual neurological items and patterns. Generalization and clinical feasibility require further documentation: 1) Reproducibility in cohorts of other composition, 2) validity with comparison to currently applied standards, and 3) potential benefits that can be attained by the examination.

Manual strength testing in 14 upper limb muscles: a study of inter-rater reliability.

BACKGROUND: Manual muscle testing has been termed a "lost art" and is often considered to be of minor value. The aim of this investigation was to study the inter-rater reliability of manual examination of the maximal voluntary strength in a sample of upper limb muscles. PATIENTS AND METHODS: The material consisted of a series of 41 consecutive patients (82 limbs) who had been referred to a clinic of occupational medicine for various reasons. Two examiners who were blinded as to patient-related information classified 14 muscles in terms of normal or reduced strength. In order to optimize the evaluation, the individual strength was assessed simultaneously on the right and left sides with the limbs in standardized positions that were specific for each muscle. Information on upper limb complaints (pain, weakness and/or numbness/tingling) collected by two other examiners resulted in 38 limbs being classified as symptomatic and 44 as asymptomatic. For each muscle the inter-rater reliability of the assessment of strength into normal or reduced was estimated by kappa-statistics. In addition, the odds ratio for the relation to symptoms of the definition in agreement of strength was calculated. RESULTS: The median kappa-value for strength in the muscles examined was 0.54 (0.25-0.72). With a median odds ratio of 4.0 (2.5-7.7), reduced strength was significantly associated with the presence of symptoms. INTERPRETATION: This study suggests that manual muscle testing in upper limb disorders has diagnostic potential.