Anterior Interosseous Syndrome Research Articles

Anterior Interosseous Nerve Syndrome Reconsidered: A Critical Analysis Review.

Anterior interosseous nerve syndrome (AINS) represents a form of neuralgic amyotrophy (Parsonage-Turner syndrome). AINS does not originate from external compression of the AIN in the forearm. Fascicular constrictions (FCs) of the median nerve are identified within the anterior interosseous fascicular group at or above the medial epicondyle. Spontaneous recovery is not ensured, leaving up to 30% of patients with permanent weakness or palsy. Fascicular microneurolysis of the median nerve, performed at or above the elbow, is a treatment option for patients who do not recover spontaneously.

Anterior Interosseous Nerve Syndrome due to Extravasation of Intravenous Infusion

Anterior interosseous nerve is a motor branch from median nerve. It innervates three muscles, the flexor pollicis longus, the flexor digitorum profundus, and the pronator quadratus muscles in the forearm. Anterior interosseous nerve syndrome refers to a neuropathy affecting this nerve, to develop weakness of innervated muscles. The etiology can be diverse and the pathophysiology is not clearly documented. We report a case of a 67-year-old male patient with diabetes, who presented symptoms of right thumb and index finger weakness, forearm pain, which was in conclusion diagnosed as anterior interosseous nerve syndrome through electrodiagnostic studies. His anterior interosseous nerve syndrome was revealed as due to fluid extravasation. Fluid extravasation can cause various side effects, and peripheral nerve injury is an uncommon side effect. This is a rare case of anterior interosseous nerve syndrome developed from fluid extravasation. Keywords: Neuropathy; Extravasation

Anterior Interosseous Nerve Syndrome: Is it a Compressive Neuropathy?

Anterior interosseous nerve (AIN) syndrome is a rare disease whose pathophysiology is controversial. Despite efforts to elucidate the pathophysiology of AIN syndrome, it has not yet been resolved. We reinterpret electrodiagnostic studies, magnetic resonance imaging (MRI), and surgical findings to clarify the pathophysiology of AIN syndrome. In this retrospective case series, we included surgically treated 20 cases of nontraumatic AIN syndrome. Surgery was performed after a minimum of 12weeks of conservative treatment. The clinical data and operation records were extracted from the medical records for analysis. All electrodiagnostic tests were reinterpreted by physicians with an American Board Certification in electrodiagnostic medicine. Moreover, every contrast-enhanced MRI performed during the assessment was reviewed by a musculoskeletal radiologist. Of the twenty re-analyzed cases, nine AIN syndromes (45%) showed abnormal electromyography in non-AIN innervated muscles. Sensory nerve conduction studies were normal in all cases. Five magnetic resonance images (46%) showed signal changes in non-AIN-innervated muscles. Only four cases (20%) revealed definitive compression of the AIN during surgery. Electrodiagnostic study and MRI indicated that many patients with AIN syndrome exhibited a diffuse pathologic involvement of the motor component of the median nerve. We conclude that the main pathophysiology of AIN syndrome would be diffuse motor fascicle neuritis of the median nerve in the upper arm.

Treatment of spontaneous anterior interosseous nerve palsy.

The purpose of this study was to clarify the clinical outcomes of spontaneous anterior interosseous nerve palsy (AINP) treated nonsurgically or surgically. The authors retrospectively evaluated the clinical course of 27 patients affected with AINP, treated nonsurgically or surgically. Thirteen patients underwent surgical treatment (interfascicular neurolysis), and 14 patients underwent conservative nonsurgical treatment. The mean patient age at the onset of symptoms was 49 years (range 17-77 years). The mean follow-up duration from onset to the latest follow-up examination was 23 months (range 12-38 months). In 12 of 14 patients receiving conservative treatment, signs of recovery from the palsy were obtained within 6 months. These patients showed a recovery of manual muscle test (MMT) grade ≥ 3. In contrast, 2 patients who took more than 12 months from symptom onset to initial recovery showed poor recovery (MMT grade ≤ 2). Surgical treatment was performed in 13 patients because of no sign of recovery from palsy. The mean period from symptom onset to the operation was 8.4 months (range 6-14 months). Ten of 13 patients who underwent surgical treatment within 8 months after symptom onset showed good recovery, with MMT grade ≥ 4. However, 3 patients who underwent surgical treatment more than 12 months after onset showed recovery with MMT grade ≤ 3. Conservative treatment for AINP may be continued when patients show signs of recovery within 6 months after symptom onset. In contrast, surgical treatment may be performed within 8 months from the onset of symptoms when the patients show no recovery signs for 6 months. AIN = anterior interosseous nerve; AINP = anterior interosseous nerve palsy; FDP1 = flexor digitorum profundus of the index finger; FPL = flexor pollicis longus; MMT = manual muscle test; NSG = nonsurgical treatment group; SG = surgical treatment group.

Compression Neuropathies

Compression neuropathies result from entrapment at specific anatomic locations. They are a common clinical problem, particularly in the upper extremity, where a patient’s underlying medical conditions can affect the likelihood of symptoms. Early recognition from the clinical history and a detailed examination, including provocative maneuvers, combined with electrodiagnostic testing or imaging modalities is imperative to guide treatment and prevent permanent dysfunction. This review contains 7 figures, 2 tables, and 45 references. Keywords: carpal tunnel syndrome, cubital tunnel syndrome, radial tunnel syndrome, ulnar tunnel syndrome, pronator syndrome, anterior interosseous syndrome, entrapment neuropathy, electrodiagnostic studies

The Reverse Oblique Supracondylar Humerus Fracture: Description of a Novel Fracture Pattern.

Sagittal profile descriptions of supracondylar humerus fractures are limited. We describe a reverse oblique (RO) pattern in which the distal fragment has a prominent anterior spike that is displaced posterior to the proximal fragment. This pattern presents a challenge during closed manipulation utilizing traditional reduction maneuvers. The purpose of this study is to compare the clinical and radiographic characteristics of the RO and non-RO patterns of supracondylar humerus fractures. We hypothesized that the RO pattern would be associated with greater soft tissue trauma. Retrospective evaluation of operative supracondylar humerus fractures treated at a tertiary pediatric hospital from 2014 to 2016. Patients were categorized into RO and non-RO groups for analysis. Associated neurovascular injuries were compared between groups. Two hundred ninety-nine consecutive patients were reviewed. The RO fracture pattern was seen in 12 patients. All displaced RO fractures were able to be closed reduced with a modification to the traditional reduction sequence. Overall cohort rates of preoperative soft tissue injury included antecubital ecchymosis 16.8%, nerve palsies 15%, and vascular compromise 6.4%. Compared with non-RO fractures, the RO fracture group had significantly higher rates of anterior interosseous nerve (AIN) palsies (P=0.013), antecubital ecchymosis (P=0.018), and compartment syndrome (P=0.043). When comparing RO with non-RO type II fractures, there were no differences in soft tissue injury (P=0.439). Compared with non-RO type III fractures, RO type III fractures had higher rates of AIN injury (P=0.047), antecubital ecchymosis (P=0.007), and overall soft tissue injury (P=0.009). This study introduces a previously undescribed supracondylar humerus fracture subtype: the RO fracture. We found increased rates of soft tissue compromise including antecubital ecchymosis and AIN palsy in this fracture type. Further, traditional reduction methods proved to be ineffectual for this fracture pattern. We utilized a simple modification that allowed for closed reduction and percutaneous pinning of displaced RO fractures. Level III-prognostic.

Flexor Tendon Rupture After Distal Radius Malunion Associated With Electromyographic Abnormalities

A 63-year-old woman with a history of a malunited distal radius fracture presented with left hand pain and inability to flex her thumb, index, and middle fingers. Anterior interosseous neuropathy was suggested because of abnormal electromyography findings. However, magnetic resonance imaging later revealed flexor tendon ruptures. A distal radius corrective osteotomy with autograft and volar fixation was performed with tendon transfers and carpal tunnel release. Attritional flexor tendon rupture after a nonoperatively managed distal radius fracture is rare but remains an important differential diagnosis in patients with signs and symptoms of anterior interosseous nerve paralysis.

Fascicular constrictions above elbow typify anterior interosseous nerve syndrome.

In this study we tested the hypothesis that fascicular constrictions (FCs) of the median nerve proximal to the elbow joint characterize anterior interosseous nerve syndrome (AINS). Magnetic resonance neurography (MRN) and ultrasound (US) examinations were evaluated in 45 patients with clinically suspected AINS. All 22 patients at site 1 underwent MRN and 8 underwent US; all 23 patients at site 2 underwent US. Median nerve FCs were identified in all MRN cases; FCs and/or fascicular enlargements were identified in 88% of US cases. Most FCs were in the mediannerve posterior/posteromedial region and were proximal to the elbow joint line (mean distance: MRN, 5.4 cm; US, 7.5 cm), with the exception of a single FC (located 1 cm distal). No extrinsic compression of median or anterior interosseous nerves was identified in the arm or forearm. AINS is a noncompressive neuropathy characterized by median nerve FCs in the arm.

Triceps-sparing Posterior Approach for Supracondylar Humeral Fracture in Children.

The most common pediatric elbow fracture is supracondylar humeral fracture which accounts for 60% of elbow fractures in children. The aim of this study was to evaluate the results of open reduction and internal fixation of type III supracondylar humeral fractures using a Triceps sparing posterior approach. In total, 98 patients were evaluated from June 2007 to 2014. According to the results, the mean age of the patients was 6.4 years. The ratios of males to females and the right to left hand were 2.06 and 2.26, respectively. Totally, 82% of fractures happened in the dominant hand which was right. The patients underwent surgery within approximately 50.16 hours after injury. Anatomic reduction and internal fixation were performed under direct vision with no need for image intensifier. The mean time of follow-up was 14.3 months, and all fractures healed clinically and radiologically. Moreover, the maximum lack of an extension was 15° and the obtained mean was 3.5°. Additionally, the mean final Bauman angle difference with healthy elbow was determined at 2.4°. The rate of complications was 19.3%, including pin tract infections (7%), pin loosening (3%), heterotopic ossification (4%), and wound dehiscence (1%). Furthermore, there were 4 cases (4%) of anterior interosseous nerve palsy, two of which happened before surgery, and the other two following the surgery. All of these complications were resolved within 3 to 10 weeks spontaneously. This approach helped preserve the extensor mechanism and ulnar nerve intact to have an acceptable skin scar esthetically along with satisfactory postoperative function.

Síndrome do pronador redondo associada à síndrome do nervo interósseo anterior: relato de caso

A síndrome do pronador redondo é caracterizada por dor vaga na superfície volar do antebraço, com parestesias na área de inervação sensitiva do nervo mediano e achados motores mínimos. A síndrome do nervo interósseo anterior é uma paralisia motora pura dos músculos inervados por esse nervo: o flexor longo do polegar, o flexor profundo dos dedos indicador e médio e o pronador quadrado. Normalmente, os resultados de estudos eletrodiagnósticos são normais em pacientes com síndrome do pronador redondo e anormais em pessoas com síndrome do nervo interósseo anterior. A síndrome do pronador redondo é um diagnóstico controverso e ela é normalmente tratada cirurgicamente. A síndrome do nervo interósseo anterior é cada vez mais pensada como uma neurite, que muitas vezes resolve espontaneamente após observação prolongada. As indicações cirúrgicas para descompressão do nervo incluem sintomas persistentes por mais de 6 meses em pacientes com síndrome do pronador redondo ou por um período mínimo de 12 meses, sem sinais de melhora motora, em pacientes com síndrome do nervo interósseo anterior.

Anterior Interosseous Nerve Palsy After Shoulder Arthroscopy Treated With Surgical Decompression: A Case Series and Systematic Review of the Literature.

Background: Anterior interosseous nerve (AIN) palsy is a very uncommon cause of upper extremity pain and weakness that comprises less than 1% of all upper extremity nerve palsies. Rarely reported but also mentioned in the literature is AIN palsy after shoulder arthroscopy. Methods: A systematic review of the literature to date using PubMed was conducted to identify patients who suffered AIN palsy after shoulder arthroscopy procedures. Articles included met the following criteria: (1) published in English; (2) primary presentation of the data; (3) patients had undergone shoulder arthroscopy before developing symptoms of AIN palsy; and (4) diagnosis was confirmed with clinical symptoms of AIN palsy. Measured outcomes included patient demographics, specific shoulder procedure, anesthesia procedure, intra-operative patient positioning, intra-operative compressive dressing, intra-operative traction, surgical versus conservative treatment, abnormal findings during decompression procedure, proposed mechanism of injury, and follow-up. Results: The search yielded 6 articles, of which 4 (13 cases) met inclusion criteria. An additional 2 cases were included in this report totaling 15 cases. The average patient age was 49 years (range: 31-64) with 73% males. At average follow-up of 24 months, 67% of patients experienced complete resolution of symptoms-more than half of which underwent surgical decompression. Patients who failed to progress experienced weakness of the flexor digitorum profundus and flexor pollicis longus muscles. Conclusions: Proposed injury mechanisms for AIN palsy after shoulder arthroscopy range from mechanical trauma, compressive hematoma, and direct anesthetic neurotoxicity. Management should be directed by clinical symptoms, imaging, and patient factors with majority of patients expected to have excellent clinical outcomes.

Accessory head of the flexor pollicis longus muscle: anatomical study and clinical significance.

The accessory head of the flexor pollicis longus (AHFPL) has an oblique trajectory from medial to lateral aspect of the forearm below the flexor digitorum superficialis muscle and then joins the flexor pollicis longus muscle. When the anterior interosseous nerve (AIN) courses underneath the muscle belly of the AHFPL an entrapment neuropathy may occur, known as anterior interosseous nerve syndrome (AINS). This descriptive cross-sectional study evaluated 106 fresh upper extremities. When the AHFPL was present, its fascicle was traced up to evaluate the origin site. The morphometric variables were measured using a digital micrometre (Mitutoyo, Japan). The relationship between the AHFLP and the AIN was evaluated. The AHFPL was found in 34 (32.1%) of the 106 forearms. The AHFPL arose from the flexor digitorum superficialis muscle in 16 (47.1%) forearms, the medial epicondyle of the humerus in 10 (29.4%) forearms and the coronoid process of ulna in 8 (23.5%) forearms. The average total length of the AHFPL was 94.11 ± ± 10.33 mm. The AIN was located lateral to the AHFPL in 3 (8.8%) forearms, posterolateral in 7 (20.6%) forearms and posterior in 24 (70.6%) forearms. This study performed in a South American population sample revealed a prevalence of the AHFPL in a lower range compared to previous studies in North Americans and Asians. The AIN coursed more frequently underneath the muscle belly of AHFPL. This finding has clinical significance in the onset of the AINS and the subsequent surgical procedure for the AIN decompression.

A cadaveric study on the persistence of the median artery

The median artery is a transitory artery that supplies blood to the forearm and hand of an embryo. This artery regresses at the 8th week of gestation upon the development of the radial and the ulnar arteries. However, the median artery may persist in adults and such persistence can lead to many complications including median nerve compression and related syndromes such as carpal tunnel syndrome, anterior interosseous nerve syndrome and pronator teres syndrome. The persistent median artery has been shown to be highly variable in its origin, and has been shown to arise either from the brachial, radial, ulnar, common interosseous or anterior interosseous arteries. The prevalence of persistent median arteries has a wide range, reported as 1.1% – 27.1%. Studies reporting the prevalence, origin of the persistent median artery and its contribution to the complete or the incomplete palmar arch have been highly variable. Additionally, no study has documented the prevalence of this artery in the population of donated cadavers within the UT Health San Antonio Human Anatomy Program. Furthermore, publications demonstrating the presence of other arterial variations in the upper extremity in association with the presence of the persistent median artery in this donated cadaver population are very limited. Awareness of such anatomical variations is extremely critical for clinicians performing reconstructive surgeries involving the arteries of the upper extremity to optimize patient outcomes.Specific aims of this study are 1. To determine the prevalence and the origin of the persistent median artery in this donated population of cadavers 2. To investigate whether the persistence of a median artery is associated with other arterial variations in the arm & the forearm 3. To elucidate the contribution of the persistent median artery to the complete or incomplete superficial palmar arch. To address these specific aims, 54 upper limbs of donated cadavers were surveyed. Preliminary data suggest the incidence of persistent median artery to be 29.63% (16/54). Furthermore, 25% (4/16) of the upper limbs with a persistent median artery presented with a high division (proximal to the cubital fossa) of the brachial artery into the radial and the ulnar arteries. Additionally, 43.8% (7/16) of these persistent median arteries entered the hand through the carpal tunnel and supplied the digits. 31.3% (5/16) of these persistent median arteries contributed to an incomplete superficial palmar arch and 12.5% (2/16) contributed to a complete superficial palmar arch. We are currently surveying more cadavers. Knowledge provided from this project will allow not only a better understanding of the prevalence of this artery, but also an understanding of clinical correlates that arise due to the presence of the persistent median artery.Support or Funding InformationNoneThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Diffusion tensor imaging in anterior interosseous nerve syndrome - functional MR Neurography on a fascicular level.

PurposeBy applying diffusor tensor imaging (DTI) in patients with anterior interosseous nerve syndrome (AINS), this proof of principle study aims to quantify the extent of structural damage of a peripheral nerve at the anatomical level of individual fascicles.MethodsIn this institutional review board approved prospective study 13 patients with spontaneous AINS were examined at 3 Tesla including a transversal T2-weighted turbo-spin-echo and a spin-echo echo-planar-imaging pulse sequence of the upper arm level. Calculations of quantitative DTI parameters including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for median nerve lesion and non-lesion fascicles as well as ulnar and radial nerve were obtained. DTI values were compared to each other and to a previously published dataset of 58 healthy controls using one-way Analysis of Variance with Bonferroni correction and p-values <.05 were considered significant. Receiver operating characteristic (ROC) curves were performed to assess diagnostic accuracy.ResultsFA of median nerve lesion fascicles was decreased compared to median nerve non-lesion fascicles, ulnar nerve and radial nerve while MD, RD, and AD was increased (p < .001 for all parameters). Compared to median nerve values of healthy controls, lesion fascicles showed a significant decrease in FA while MD, RD, and AD was increased (p < .001 for all parameters). FA of median nerve non-lesion fascicles showed a weak significant decrease compared to healthy controls (p < .01) while there was no difference in MD, RD, and AD. ROC analyses revealed an excellent diagnostic accuracy of FA, MD and RD in the discrimination of median nerve lesion and non-lesion fascicles in AINS patients as well as in the discrimination of lesion fascicles and normative median nerve values of healthy controls.ConclusionBy applying this functional MR Neurography technique in patients with AINS, this proof of principle study demonstrates that diffusion tensor imaging is feasible to quantify structural nerve injury at the anatomical level of individual fascicles.

Morphometry of the anterior interosseous nerve: a cadaveric study

Objectives: ​Pathophysiology and etiology of anterior interosseous nerve (AIN) syndrome are still controversial. This anatomical​ ​dissection study aimed to understand the anatomy of AIN. Methods: From a random sample of upper extremities of whole-body human cadavers (n=10), 20 upper extremities were included​ ​in the study. Two of the cadavers were females and 8 were males (age range 34–62 years). Specimens were dissected with​ ​the elbow in extension, wrist in neutral position and forearm in pronation. After superficial dissection, the pronator teres muscle​ ​was released, and the branching pattern of the AIN and the separation of the nerve from the interepicondylar line were​ ​recorded. The branches to the pronator teres, flexor pollicis longus, flexor digitorum profundus and flexor digitorum superficialis​ ​were recorded according to their distance from the interepicondylar line. Results: The AIN branched from the main trunk 5.1 to 47.89 mm (mean 37.58±11.25 mm) distal to the interepicondylar line.​ ​AIN gave off 1–4 branches to the pronator teres. The first branch left the AIN 10.05–83.84 mm proximal and entered the muscle​ ​23.49–43.72 mm distal to the interepicondylar line. AIN gave 1–4 branches to the flexor pollicis longus, flexor digitorum profundus​ ​and flexor digitorum superficialis at varying distances. The origin of the branches of AIN, as well as the innervation by​ ​one or multiple branches for a muscle, was variable. Conclusion: This study provides a detailed map of the anterior interosseous nerve innervating flexor pollicis longus, flexor​ ​digitorum profundus and flexor digitorum superficialis muscles, to serve as a guide for location of AIN block in patients with​ ​upper extremity spasticity and AIN syndrome.

The lesion of anterior interosseous nerve syndrome is not in the forearm

The etiology of anterior interosseous nerve syndrome (AINS) is controversial, and ranges from compressive neuropathy in the forearm to spontaneous neuritis. Since the early 1990's, several series that report hourglass constriction (HGC) of the nerves in the upper extremity, including the anterior interosseous nerve (AIN) have been reported. The link between HGC and AINS has not been definitively resolved. We hypothesize that AINS is not a compressive or inflammatory lesion of the forearm, but rather a proximal intraneural disease of the postero-medial fascicle of the median nerve. This is a retrospective radiologic review of a consecutive series of 42 limbs in 40 patients with AINS in 2 academic centers in the United States and Hungary. The diagnosis of AIN palsy was strictly defined by complete clinical and electromyographic palsy of one or more muscles of the AIN. Each patient was evaluated with MRI, ultrasound or both by an expert neurodiagnostic imaging specialist. Five patients with recalcitrant disease were treated with interfascicular epi- and peri-neurolysis for failure to recover clinically or electrically after 12.4 months (range, 10 to 16 months). Twenty-nine patients had a characteristic pain prodrome of neuralgia amyotrophy (NA) that immediately preceded the onset of motor palsy. In 15 cases, the AIN was associated with palsy of additional median-innervated muscles, including the flexor carpi radialis, pronator, and/or palmaris longus. In 26 cases an ultrasound was performed and in 20 cases a MRI was performed. At least one hourglass constriction was identified in 25 patients, with a total of 42 constrictions reported. A fascicular swelling assessed with ultrasound or hyperintensity of the posteromedial fascicular bundle of the median nerve on MRI imaging was reported in eleven patients. In 71% of cases, the constriction was proximal to the medial epicondyle (mean 1.6 cm, from 0 to 18 cm) and in 29% the constriction was distal to the medial epicondyle (mean 1.3cm, from 0 to 3.5 cm). No extrinsic compression was identified in the forearm. Surgical exploration in 5 patients precisely corroborated imaging findings. Preoperative evaluation of AINS requires electromyographic confirmation, but advanced imaging has been discouraged [1] . Recent international studies have confirmed the value of MRI and ultrasonography to identify abnormalities of nerves affected by NA [2] , [3] . These data of 42 cases of AINS confirms that the disease is an intra-neural affectation of the median nerve (neuralgia amyotrophy) and not a compressive or inflammatory lesion of the AIN in the forearm. Intraneural disease of the posteromedial fascicular group of the median nerve is the primary pathology of AINS. We recommend that patients with AINS should undergo advanced imaging of the median nerve above and below the elbow by a specialist trained in imaging of the peripheral nerve.

Anterior interosseous nerve: anatomical study and clinical implications

ObjectiveThe goal of this study was to describe anatomical variations and clinical implications of anterior interosseous nerve. In complete anterior interosseous nerve palsy, the patient is unable to flex the distal phalanx of the thumb and index finger; in incomplete anterior interosseous nerve palsy, there is less axonal damage, and either the thumb or the index finger are affected. MethodsThis study was based on the dissection of 50 limbs of 25 cadavers, 22 were male and three, female. Age ranged from 28 to 77 years, 14 were white and 11 were non-white; 18 were prepared by intra-arterial injection of a solution of 10% glycerol and formaldehyde, and seven were freshly dissected cadavers. ResultsThe anterior interosseous nerve arose from the median nerve, an average of 5.2cm distal to the intercondylar line. In 29 limbs, it originated from the nerve fascicles of the posterior region of the median nerve and in 21 limbs, of the posterolateral fascicles. In 41 limbs, the anterior interosseous nerve positioned between the humeral and ulnar head of the pronator teres muscle. In two limbs, anterior interosseous nerve duplication was observed. In all members, it was observed that the anterior interosseous nerve arose from the median nerve proximal to the arch of the flexor digitorum superficialis muscle. In 24 limbs, the branches of the anterior interosseous nerve occurred proximal to the arch and in 26, distal to it. ConclusionThe fibrous arches formed by the humeral and ulnar heads of the pronator teres muscle, the fibrous arch of the flexor digitorum superficialis muscle, and the Gantzer muscle (when hypertrophied and positioned anterior to the anterior interosseous nerve), can compress the nerve against deep structures, altering its normal course, by narrowing its space, causing alterations longus and flexor digitorum profundus muscles.

Fluid Extravasation in Shoulder Arthroscopic Surgery: A Systematic Review.

Background:Arthroscopic surgery of the shoulder joint has become increasingly more common given its advantages over open surgery; however, one rare but potentially life-threatening complication is fluid extravasation into the surrounding tissues, causing edema, respiratory compromise, abnormal results on laboratory blood tests, and possibly death. Currently, no systematic review exists that summarizes the existing clinical research on this topic.Purpose:To perform a systematic review on fluid extravasation as a complication of shoulder arthroscopic surgery, specifically assessing clinical presentation, risk factors, management, and outcomes.Study Design:Systematic review; Level of evidence, 4.Methods:Two reviewers independently searched 3 databases (PubMed, Ovid [MEDLINE], and Embase) from database inception until July 1, 2017. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist guided the reporting and data abstraction. The methodological quality of these studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS) checklist. The results are presented in a narrative summary fashion using descriptive statistics including ranges and agreement statistics.Results:A total of 26 studies (20 case reports, 4 case series, and 2 prospective comparative studies) encompassing 205 patients (mean age, 50.8 years [range, 15-83 years]) were included. The most common signs of fluid extravasation included chest wall swelling (n = 86) and neck swelling (n = 116). In 32 patients, observation alone was sufficient. Other patients required airway intubation (n = 16), diuretics (n = 7), steroids (n = 1), and percutaneous drainage of fluid (n = 1). Clinical edema resolved after 2 to 48 hours, and patients were discharged 1 to 20 days postoperatively. Serious complications included transfer to the intensive care unit (n = 14), anterior interosseous nerve palsy (n = 4), rhabdomyolysis (n = 1), and death (n = 1).Conclusion:Fluid extravasation has the potential to be a life-threatening complication of shoulder arthroscopic surgery; however, it is most commonly managed nonoperatively, and symptoms typically resolve with no evidence of long-term complications. Intraoperative surgical decisions, such as minimizing the surgical time and volume of irrigation fluid used, may limit fluid extravasation, while careful intraoperative monitoring may facilitate prompt diagnosis and management to optimize patient outcomes.

Ultrasound Evaluation of Anterior Interosseous Nerve Paralysis in Our Hospital

Ultrasound Evaluation of Anterior Interosseous Nerve Paralysis in Our Hospital

Nervo interósseo anterior: estudo anatômico e implicações clínicas

ObjectiveThe goal of this study was to describe anatomical variations and clinical implications of anterior interosseous nerve. In complete anterior interosseous nerve palsy, the patient is unable to flex the distal phalanx of the thumb and index finger; in incomplete anterior interosseous nerve palsy, there is less axonal damage, and either the thumb or the index finger are affected. MethodsThis study was based on the dissection of 50 limbs of 25 cadavers, 22 were male and three, female. Age ranged from 28 to 77 years, 14 were white and 11 were non‐white; 18 were prepared by intra‐arterial injection of a solution of 10% glycerol and formaldehyde, and seven were freshly dissected cadavers. ResultsThe anterior interosseous nerve arose from the median nerve, an average of 5.2cm distal to the intercondylar line. In 29 limbs, it originated from the nerve fascicles of the posterior region of the median nerve and in 21 limbs, of the posterolateral fascicles. In 41 limbs, the anterior interosseous nerve positioned between the humeral and ulnar head of the pronator teres muscle. In two limbs, anterior interosseous nerve duplication was observed. In all members, it was observed that the anterior interosseous nerve arose from the median nerve proximal to the arch of the flexor digitorum superficialis muscle. In 24 limbs, the branches of the anterior interosseous nerve occurred proximal to the arch and in 26, distal to it. ConclusionThe fibrous arches formed by the humeral and ulnar heads of the pronator teres muscle, the fibrous arch of the flexor digitorum superficialis muscle, and the Gantzer muscle (when hypertrophied and positioned anterior to the anterior interosseous nerve), can compress the nerve against deep structures, altering its normal course, by narrowing its space, causing alterations longus and flexor digitorum profundus muscles.