Anconeus Research Articles

Residual Elbow Instability Treated with a Submuscular Internal Joint Stabilizer: Prospective and Consecutive Series with a Minimum Follow-Up of 12 Months

Background: The management of residual elbow instability is a challenging and compelling issue for treating physicians. To overcome inherent drawbacks of dynamic external fixators, the internal joint stabilizer (IJS) has been developed, achieving successful results, but it can sometimes cause local tenderness or anesthetic concerns in the subcutaneous layer. In addition, a bulky anconeus can pull the hardware away from the axis of rotation with an increase in the lever arm and potential issues. To address these issues, an alternative approach has been recently described in which the internal device is covered by the anconeus muscle, becoming submuscular, rather than subcutaneous. The aim of this study was to evaluate the effectiveness of this alternative approach to the IJS application in maintaining a concentric elbow during and after device removal in both acute and chronic scenarios. Methods: Prospective data collection was performed with consecutive patients who had residual elbow instability treated with an IJS (Skeletal Dynamics, Miami, FL) covered by the anconeus from January 2022 and with a minimum follow-up of 12 months. Results: At a medium follow-up of 16 months, the 16 patients selected had a mean arc of flexion–extension of 123° (range: 0–140°) and a mean pronation-supination arc of 150° (range: 80–80°). The mean MEPS and DASH scores were 90.3 ± 6.2 and 6.3 ± 5.3, respectively. At the last follow-up, elbow stability and concentric reduction were confirmed with radiographic and clinical examinations. Conclusions: With a minimum follow-up of 12 months, the present study supports the safety and efficacy of the internal device in a submuscular layer. The clinical outcomes and the rate of recurrent instability are comparable to those achieved with a classic subcutaneous position. Similarly, the complication rate is not affected, and removal surgery is no more aggressive than the classic approach.

Anconeus Exertional Compartment Syndrome and Posterolateral Rotatory Elbow Instability: A Clinical Association and Rare Cause of Elbow Pain

Background: Anconeus compartment syndrome is a rarely reported compartment syndrome in the anconeus muscle compartment of the forearm. It has anatomic and pathophysiological associations with posterolateral rotatory instability (PLRI) of the elbow. Purpose: To present the history, management, and outcomes of 4 patients with anconeus compartment syndrome. Secondary aims were to (1) establish normative anconeus pressures and (2) measure the volume of this compartment with and without PLRI in cadavers. Study Design: Case series; Level of evidence, 4. Methods: Four patients with clinical signs of anconeus compartment syndrome (2 gymnasts, 1 swimmer, and 1 footballer/weightlifter) were identified over a 3-year period (2015-2017 inclusive). Patient history, sporting activity, physical examination, anconeus compartment pressures, and treatment outcomes were recorded. Manometry of the anconeus compartment in 2 healthy male controls was performed to establish normative compartment pressures. Anconeus volumetric anatomy and the effect of creating PLRI on compartment volume was investigated in 4 cadaveric elbows. Results: All 4 patients had microtraumatic PLRI, and 2 patients had anconeus hypertrophy. Anconeus compartment pressures at rest and at 2-minutes postexercise were median 28.0 and 67.5 mm Hg, respectively, in the patients and mean 16.5 and 18 mm Hg, respectively, in the controls. Simultaneous fasciotomy and PLRI reconstructive procedures were performed in 2 patients, with outcomes showing full return to competition. Fasciotomy alone was performed in 2 patients to allow return to competition, with both requiring later reconstruction to address PLRI. Cadaver dissection revealed that the anconeus compartment was extremely small and that creation of PLRI reduced the direct volume of the compartment and increased the distance between the anconeus origin and insertion. Conclusion: Our case series demonstrated that anconeus compartment syndrome can occur in upper limb-dominant athletes in the presence of PLRI and anconeus hypertrophy. Pain is relieved by fasciotomy, but definitive treatment of the underlying instability prevents further symptomatology.

Technical modifications to elbow interposition arthroplasty

Interposition arthroplasty of the elbow involves the interposition of afascia lata or dermis autograft or allograft between the distal humerus and the ulna or radius, while preserving the original form of articulation. Interposition arthroplasty is indicated for young patients with high functional demands who suffer from end-stage elbow arthritis and associated pain or joint stiffness. Contraindications include acute or subacute infection, skeletal immaturity, bone loss, deformity, or gross instability. Once the ulnar nerve has been secured, joint access is established via aposterior approach. The radial collateral ligament (RCL) and the common extensor tendon origin (CEO) are detached, while preserving the anconeus muscle and the lateral ulnar collateral ligament (LUCL). Subsequently, a capsular release is required to maintain adequate joint exposure and address the accompanying stiffness. Three to four transosseous drill holes are placed at the level of the distal humerus to secure the graft. After the graft has been positioned successfully within the joint space using two guide sutures, it can be secured to the distal humerus using ahorizontal mattress stitch. Finally, the detached tendon and ligament structures are reconstructed. After initial immobilization, early functional exercise of the elbow is performed in the motion orthosis, avoiding valgus or varus stress. The efficacy of elbow interposition arthroplasty has been demonstrated, particularly for young and active patients with severe inflammatory or post-traumatic osteoarthritis. Despite the results in terms of postoperative function and pain reduction are satisfactory, the current literature reports high complication, subsequent treatment, and revision rates. In the event of interposition arthroplasty failure, revision with another interposition procedure or conversion to endoprosthesis may be considered.

A rare presentation of cubital tunnel syndrome by accessory anconeus muscle

Cubital tunnel syndrome (Cu TS) is the second most frequent upper extremity compressive neuropathy after carpal tunnel syndrome. Cu TS is idiopathic; however, it has been linked to ulnar nerve vulnerability and anconeus epitrochlearis (AE) muscle hypertrophy. Although there are few studies in the literature that reveal AE muscle as one of the causes of Cu TS, its prevalence is low. The goal of this case report is to raise awareness regarding the existence of AE muscle as a potential cause of Cu TS, as well as the imaging findings of Cu TS in magnetic resonance imaging (MRI). A 17-year-old male patient complained of intermittent pain in the medial aspect of the left elbow and paresthesia in the left hand. Examination revealed hyperextension of meta carpalphalangeal joints and flexion of proximal interphalangeal joints of the 4th and 5th digits, besides the sensory deficit along the ulnar border of the 5th digit. A nerve conduction study revealed non-stimulable sensory and motor components of the right ulnar nerve. MRI with T1-weighted fast spin echo, Fat sat proton density-weighted, and gradient echo T2*-weighted sequence showed AE - on the posteromedial aspect of the elbow. The ulnar nerve within the cubital tunnel appeared thickened and edematous with bright perineural fat signals with maintained fascicular architecture, secondary to compression by the anconeus muscle. This paper reviews imaging findings of ulnar neuropathy secondary to accessory anconeus muscle and explains the importance of MRI imaging for accurate diagnosis. Knowing MRI imaging is vital in the modern imaging era for accurate diagnosis.

Internal joint stabilizer covered by an anconeus flap for elbow instability: surgical technique and preliminary results

BackgroundThe management of residual elbow instability is a challenge in both acute and chronic injuries. Hinged external fixators have been used but they are clumsy and associated to high rate of pin track complications. To address these issues, an internal joint stabilizer (IJS) was developed, but a subcutaneous frame may provide local tenderness and patients ‘complains. To improve the local comfort, the present study describes an alternative surgical approach in which the internal device is covered by the anconeus muscle becoming submuscular rather than subcutaneous as originally described. MethodsA prospective collection was performed of consecutive patients managed with an IJS (Skeletal Dynamics, Miami, FL, USA) as a temporary and additional stabilization for a residual elbow instability and covered by an anconeus flap. ResultsTen consecutive patients underwent IJS covered by an anconeus flap from January 2022, of whom eight with an acute injury and two suffering chronic injuries. At the mean follow-up of 13.5 months, all the patients had a stable elbow with a maintained concentric reduction. Successful results were achieved in terms of pain, ROM and clinical outcomes. All patients underwent removal surgery at an average of 5.5 months without any local discomfort or complains. The device removal required a small anconeus elevation which appeared of good quality in each patient analyzed. ConclusionThe IJS represents an effective and reliable option as a temporary stabilization for residual elbow instability. When performing a lateral approach with an anconeus flap, the internal device can be completely covered by the muscle belly at the end of the procedure. The preliminary results suggest at least similar tolerance and patient ‘satisfaction without any relevant increase in complication rare.

A 3D Printed Anatomically Pre-Contoured Plate for the Treatment of Y-T Humeral Condylar Fractures: A Feline Cadaveric Study.

(1) Background: Anatomically pre-contoured plates usually require only minimal or even no intraoperative contouring. For complex cases, such plates also assist the surgeon as an anatomical template during fracture reduction. In this study, we present our experience of using a 3D printing technology for the treatment of bicondylar humeral fractures in feline cadavers. (2) Methods: Surgeries were performed on 15 pairs of front limbs amputated at the scapula. The limbs were obtained from 15 adult cats without obvious pathology of the skeleton. After flexion of the elbow and subperiosteal elevation of the anconeus muscle, the humeral Y-T fractures were created using a bone chisel and mallet. A custom-made anatomically pre-contoured interlocking plate was used to reduce and stabilise the medial aspect of the humeral condyle to the humeral diaphysis. After reduction of the humeral condyle, a positional locking screw was then inserted from the medial to the lateral side and a straight 2.4/2.7 interlocking bone plate was used to stabilise the lateral part of the condyle to the humeral diaphysis. (3) Results: The length of the humerus ranged from 98.2 to 107.0 mm and did not differ significantly between the left and right bone. The diameter of the isthmus of the humeral condyle ranged from 5.2 to 5.5 mm and did not differ significantly between the left and right bone. In all 30 limbs, bicondylar fracture was accompanied by epicondylar comminution. In 7/30 limbs (4 left, 3 right) the fracture of the humeral shaft was also present. In the left limbs, the postoperative articular surface defect of the humeral condyle was small (<1 mm) in 11/15 cases, moderate (1-2 mm) in 2/15 cases and large (>2 mm) in 2/15 cases in which the condylar screw was incorrectly inserted. In the right limbs, the postoperative articular surface defect of the humeral condyle was small (<1 mm) in 14/15 cases and moderate (1-2 mm) in 1 case. (4) Conclusions: 3D printing and the technology of metal powder sintering offers a wide range of possibilities for the development of new surgical implants. The anatomically pre-contoured bone plate appears to be a valuable tool in the reduction and stabilisation of Y-T humeral fractures in adult domestic cats weighing 3.0 to 4.5 kg.

The prevalence of the anconeus epitrochlearis muscle in a Central European population.

An anconeus epitrochlearis muscle (AE) is a common anatomical variant in the upper extremity, located at the medial aspect of the elbow. Its anatomical position contributes to the roof of the cubital tunnel. While it plays a role in protecting the ulnar nerve, it may also pose a risk for ulnar nerve compression. This study aimed to determine the true prevalence of AE in a Central European population. The presence of AE was evaluated in 115 cadaveric upper extremities from an undetermined number of subjects. The limbs for dissection were assumed to be healthy, and AE identification involved anatomical description and measurements. Data analysis aimed to determine the true prevalence, considering 95% confidence intervals. AE was present in 5 of the 115 cadaveric limbs (4.3%). Specimens lacking AE were observed, depicting normal cubital tunnel roof anatomy. When present, AE replaced the proximal part of the cubital tunnel roof, superficially coursing to the ulnar nerve. Morphological variations were noted. The true prevalence of AE was 4.3% (95% CI = 0.2%-8.4%), consistent with recent studies. Historical reports indicate varying true prevalence up to 26%, possibly linked to manual labor changes. Contrary to prior assumptions, our study did not find a significantly higher true prevalence in the European population. AE's association with cubital tunnel syndrome is complex, with both protective and potentially compressive roles.

Anconeus-sparing minimally invasive approach for lateral ulnar collateral ligament reconstruction using a triceps tendon autograft is an effective and safe treatment for chronic posterolateral instability of the elbow

Surgical treatment helps to restore stability of the elbow in patients with posterolateral rotatory instability (PLRI). The anconeus muscle is one of the most important active stabilizers against PLRI. A minimally invasive anconeus-sparing approach for lateral ulnar collateral ligament (LUCL) reconstruction using a triceps tendon autograft has been previously described. The purpose of this study was to evaluate the outcome of this intervention and identify risk factors that influenced the clinical and patient-reported outcomes. Sixty-one patients with chronic PLRI and no previous elbow surgery who underwent surgical reconstruction of the LUCL using a triceps tendon autograft in a minimally invasive anconeus-sparing approach during 2012 and 2018 were evaluated. Outcome measures included a clinical examination and the Oxford Elbow Score (OES) and the Mayo Elbow Performance Score (MEPS) questionnaires. Subjective patient outcomes were evaluated with the visual analog scale (VAS) for pain and the Subjective Elbow Value (SEV). Integrity of the common extensor tendons and centering of the radial head were assessed preoperatively on standardized magnetic resonance images (MRIs). Fifty-two patients were available at final follow-up. The mean age of patients was 51±12 years with a mean follow-up of 53±14 months (range 20-76). Clinical examination after surgery (n=41) showed no clinical signs of instability in 98% of the patients (P<.001) and a nonsignificant improvement in range of motion. OES, MEPS, and VAS scores averaged 40±10 of 48 points, 92±12 of 100 points, and 1±2 points, respectively, all corresponding with good or excellent outcomes. The SEV was 88%, indicating very high satisfaction with the surgery. Only 1 patient had revision surgery due to pain, and there were no reported postoperative complications in this cohort. A radial head subluxation in the MRI correlated significantly with worse postoperative outcomes. The anconeus-sparing minimally invasive technique for posterolateral stabilization of the elbow using a triceps tendon autograft is an effective and safe treatment for chronic posterolateral instability of the elbow with substantial improvements in elbow function and pain relief with a very low rate of persistent clinical instability.

Anconeus Muscle Transfer to Correct or Prevent Wrist Radial Deviation in Radial and Posterior Interosseous Nerve Injuries

Wrist radial deviation is a possible complication of tendon transfer for restoration of wrist extension in cases of radial nerve paralysis. In posterior interosseous nerve (PIN) injury, this is because of the imbalance caused by the intact extensor carpi radialis longus and paralysis of the extensor carpi ulnaris (ECU). This deformity may also occur following transfer of the pronator teres (PT) to the extensor carpi radialis brevis (ECRB) for radial nerve palsy. To address wrist radial deviation, we propose transferring the anconeus muscle, extended by the intermuscular septum between the ECU and the flexor carpi ulnaris (FCU), to the ECU tendon. Through an incision over the ulna, the intermuscular septum between the ECU and FCU is harvested at the level of the periosteum and left attached to the anconeus proximally. The anconeus muscle is then released from the ulna, and the intramuscular septum extension is sutured to the ECU tendon under maximal tension. Anconeus muscle transfer was performed on two patients to correct chronic wrist radial deviation following PT to ECRB tendon transfer for radial nerve injury, as well as on two patients with PIN paralysis. In four patients, transfer was performed in addition to standard tendon transfers for radial nerve paralysis to prevent radial wrist deviation deformity. Wrist radial deviation was corrected or prevented in all but one patient at an average follow-up of 10 months. Patients with PIN lesions and those who had anconeus transfer concomitantly with radial nerve tendon transfers were capable of active ulnar deviation. No patient experienced elbow extension weakness, pain, or instability. Anconeus muscle transfer extended by intermuscular septum presents a viable alternative for addressing radial deviation of the wrist in cases of PIN nerve lesions or following PT to ECRB tendon transfer in radial nerve paralysis. Therapeutic V.

The Boyd approach: a valuable alternative to treating simple to complex elbow fractures and dislocations.

The Boyd approach is a single-incision posterior approach to the proximal radius and ulna based on a lateral anconeus muscle reflection and release of the lateral collateral ligamentous complex. This approach remains a lesser-used technique following early reports of proximal radioulnar synostosis and postoperative elbow instability. Although limited by small case series, recent literature does not support these early reported complications. This study presents a single surgeon's outcomes using the Boyd approach for the treatment of simple to complex elbow injuries. Following institutional review board approval, a retrospective review of all patients with simple to complex elbow injuries treated consecutively using a Boyd approach by a shoulder and elbow surgeon was conducted from 2016 to 2020. All patients with at least 1 postoperative clinic visit were included. Data collected included patient demographics, injury description, postoperative complications, elbow range of motion, and radiographic findings including heterotopic ossification and proximal radioulnar synostosis. Categorical and continuous variables were reported using descriptive statistics. A total of 44 patients were included with an average age of 49 years (range 13-82 years). The most commonly treated injuries were Monteggia fracture-dislocations (32%) and terrible triad injuries (18%). Average follow-up was 8 months (range 1-24 months). Final average elbow active arc of motion was from 20° (range 0°-70°) of extension to 124° (range 75°-150°) of flexion. Final supination and pronation were 53° (range 0°-80°) and 66° (range 0°-90°), respectively. There were no cases of proximal radioulnar synostosis. Heterotopic ossification contributing to less than functional elbow range of motion occurred in 2 (5%) patients who elected conservative management. There was 1 (2%) case of early postoperative posterolateral instability due to repair failure of injured ligaments that required revision using a ligament augmentation procedure. Five (11%) patients experienced postoperative neuropathy, including 4 (9%) with ulnar neuropathy. Of these, 1 underwent ulnar nerve transposition, 2 were improving, and 1 had persistent symptoms at final follow-up. This is the largest case series available demonstrating the safe utilization of the Boyd approach for the treatment of simple to complex elbow injuries. Postoperative complications including synostosis and elbow instability may not be as common as previously understood.

Anconeus epitrochlearis muscle (epitrochlearisanconeus muscle; Musculus epitrochleoanconeus) with cubital tunnel syndrome – a rare but relevant clinical entity

BackgroundCompression of the ulnar nerve at the elbow within the cubital tunnel is related to the anatomical structures and is generally believed to be caused by Osborne's ligament (also known as the cubital retinaculum). However, in rare cases an anatomical variation of the developmental peculiarity of a remaining anconeus epitrochlearis muscle may be responsible for the disease. MethodsWe present a series of five cases in which an anconeus epitrochlearis muscle was found as the cause of illness. ResultsAll patients presented with typical symptoms of numbness and tingling in the hand and ulnar fingers, and recurring pain as well as weakness of the ulnar innervated muscles. With neurophysiologically confirmed diminished nerve conduction velocity and unsuccessful conservative treatment, surgical decompression revealed an anconeus epitrochlearis muscle as the reason of compression. Full symptom relief was achieved immediately after the procedure in all cases. ConclusionsThis article strives to call attention to this entity when diagnosing ulnar nerve compression. Myectomy and medial epicondylectomy is the preferred treatment option in such cases.

Motor unit firing rates in young and very old adult males during an isokinetic fatiguing task and short-term recovery in the anconeus muscle.

Understanding motor unit (MU) properties with muscle fatigue in adult aging is limited to isometric tasks. The purpose was to investigate the effect of an isokinetic fatiguing task on MU firing rates between two adult age groups of males. Single MUs were recorded by intramuscular electrodes in the anconeus muscle of eight young (19-33 yr) and 11 very old adults (78-93 yr). Fatigue was induced by repeated isokinetic maximal voluntary contractions at 25% of maximum velocity (Vmax), until elbow extension power decreased by 35%. At baseline, the very old had lower maximal power (135 vs. 214 W, P = 0.002) and slower maximal velocity (177 vs. 196°/s, P < 0.001) compared with young. Despite a similar number of contractions (average 39 young and 44 very old) to task failure (P = 0.33), the older males were less fatigable as time under tension was ∼25% longer (P = 0.04). Maximum firing rates from ∼20 single MUs per age group were tracked continuously throughout the task and during 10 min of recovery. Similar rates were recorded (24.7 and 23.6 Hz, P = 0.18) at baseline 25% Vmax, and during the task (23.3 and 28.7% decrease, P = 0.21) between young and very old, respectively. Power and MU rates were recovered similarly by 2 min of rest in both groups (all P > 0.15). Despite differences in baseline capability, very old males in this relatively slow isokinetic task were more fatigue resistant, but the fatigue-related reduction and recovery in MU rates were similar between groups. Therefore, fatigue in this task between age groups is not differentially affected by alterations in firing rates.NEW & NOTEWORTHY Maximal motor unit firing rates were recorded during an isokinetic fatiguing protocol and short-term recovery in young and very old adult males. Prior studies were limited to isometric fatiguing tasks. Despite the old being ∼37% weaker and less fatigable, anconeus rates during elbow extension declined with fatigue and recovered similarly to young males. Therefore, it is unlikely that greater fatigue resistance of very old males during isokinetic contractions is related to differences in motor unit rates.

Can elbow arthroscopic posterior portals damage the anconeus nerve? A cadaveric study.

Neurological injuries are among the most reported complications of elbow arthroscopy. Several cadaveric studies have assessed the relationship between nerves and arthroscopic portals. To our knowledge, no studies evaluated the anconeus nerve. This anatomic study aimed to identify the course of the anconeus nerve and to investigate its anatomic relation with posterior elbow portals, providing useful information to preserve it during surgery. Twelve fresh frozen elbows were dissected to isolate the radial nerve and its branch to the anconeus muscle. Distances between the anconeus nerve, olecranon tip, and lateral epicondyle were measured. Posterior, posterolateral and soft spot portals were created and their proximity to the nerve was measured. The anconeus nerve showed an average distance from the lateral epicondyle of 19.67 mm (SD 1.44 mm) and from the olecranon of 22.33 mm (SD 1.72 mm). The posterolateral portal was 1 mm medial to the nerve. The soft spot portal was located where the nerve enters the muscle. An important finding of this study was the closeness between the anconeus nerve and the posterolateral and soft spot portals, resulting in a high risk of nerve damage. More medial placement of the posterolateral portal may avoid anconeus nerve injury and consequent muscle denervation.

Diffusion Tensor Imaging of Ulnar Neuropathy Caused by an Accessory Anconeus Muscle.

HomeRadiologyRecently Published PreviousNext Reviews and CommentaryFree AccessImages in RadiologyDiffusion Tensor Imaging of Ulnar Neuropathy Caused by an Accessory Anconeus MuscleTeodoro Martín-Noguerol , Antonio LunaTeodoro Martín-Noguerol , Antonio LunaAuthor AffiliationsFrom the Department of Radiology, MRI Unit, HT Médica, Clínica Las Nieves, Calle Carmelo Torres 2, 23007 Jaén, Spain.Address correspondence to T.M.N. (email: [email protected]).Teodoro Martín-Noguerol Antonio LunaPublished Online:Mar 21 2023https://doi.org/10.1148/radiol.221854MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In A 29-year-old woman presented with complaints of progressive numbness in the left ulnar nerve territory. Physical examination demonstrated left ring and little finger weakness and hypoesthesia with positive flexion elbow test. MRI of the elbow with diffusion tensor imaging (DTI) neurography was performed and revealed extrinsic compression of the ulnar nerve by an accessory anconeus epitrochlearis muscle (Figure). DTI neurography scan showed deformity of the ulnar nerve with corresponding focal decrease in fractional anisotropy (FA) values at the compression site (0.3). FA values were also slightly decreased distally to the compression level (0.41), with normal appearance of the rest of the ulnar nerve (1).MRI scans show the left elbow in a 29-year-old woman with progressive numbness in the left ulnar nerve distribution. (A, B) Axial proton density–weighted images with spectral fat suppression show an accessory anconeus epitrochlearis muscle (arrow) with entrapment of the ulnar nerve (arrowhead). (C) Three-dimensional neurography reconstruction of diffusion tensor imaging with use of directional encoding color fused with proton density with spectral fat suppression shows deformity of the ulnar nerve at the site of extrinsic compression (arrowhead). A focal decrease in the fractional anisotropy values of the ulnar nerve (black arrow) is seen below the level of compression by the anconeus epitrochlearis muscle (white arrow).Download as PowerPointOpen in Image Viewer The anconeus epitrochlearis muscle is an accessory muscle located at the medial aspect of the elbow, originated at the inferior surface of medial epicondyle, and inserted at the medial cortex of the olecranon (2). The relationship between the accessory anconeus muscle and prevalence of ulnar neuropathy remains unknown (3). By providing quantitative information, DTI neurography allows detection of subtle changes in ulnar nerve morphologic conditions (4) and may prove helpful in diagnosis and treatment monitoring in ulnar neuropathy caused by accessory anconeus muscle. In the presented case, the patient was treated conservatively with a favorable clinical outcome.Disclosures of conflicts of interest: T.M.N. No relevant relationships. A.L. Royalties or licenses from Springer; fee to institution as lecturer from GE; Digital Oncology board member for Siemens Healthineers.

A modified trans-anconeus approach to facilitate fixation of a posterior radial head fracture: a cadaveric feasibility study.

Fixation of radial head fracture with minimally invasive posterior approach remains a significant challenge. The aim of this study was to determine the feasibility of trans-anconeus posterior elbow approach and to observe lateral ulnar collateral ligament (LUCL) in extended elbows. This cadaveric study was performed in twenty upper limbs of fresh fixed adult male cadavers. An oblique incision was made in the middle segment of anconeus until the lateral ligament complex and the joint capsule had been revealed. A deep dissection was explored to observe the anatomical relationship of the LUCL to the anconeus. Measurements of the LUCL were recorded while the elbow was fully extended. The mean distance between the edge of the radial head and the proximal insertion of the LUCL was 13.3 mm (11.5-16.2 mm); the mean distance between the edge of the radial head and the distal insertion of the LUCL was 20.9 mm (19.2-23.4 mm); the distance between the edge of the radial head and the distal edge of the annular ligament was 11.2 mm (8.22-11.7 mm). By estimate correlation of the previous measurements, the direct and accessible way to expose the posterolateral articular capsule of the elbow joint was through a window in medial 2/3 of the middle segment of anconeus muscle. These trans-anconeus approach is useful. It provides good visualization, facilitates applying the implants, and lessens the risk of radial nerve injury. Awareness of the anatomy is mandatory to avoid injury of LUCL.

A Combined Revision Surgical Technique for Failed Operative Lateral Epicondylitis With Concomitant Radial Tunnel Syndrome.

Lateral epicondylitis afflicts a large percentage of the population with most recovering through conservative treatment. The 5% to 10% of patients who undergo operative intervention are met with mixed results. Those that fail to improve often demonstrate a complex presentation of inadequate debridement of the "angiofibroblastic tissue," missed concomitant radial tunnel syndrome, and iatrogenic residual devascularized tissue resulting from the index procedure. To address all 3 of these causes of failure, the authors have developed a revision procedure that includes repeat debridement of residual tendinosis, decompression of the posterior interosseous nerve, and a vascularized anconeus muscle flap to help cushion soft tissue defects and promote a healthier environment for healing. Performed initially in part in 20 patients, this combined procedure has developed into our recommended treatment for these challenging patients.

Ossification of the posterior capitellum: description of a new pathology and its radiological appearance

BackgroundBoxer elbow and handball goalkeeper elbow are causes of impingement characterized by osteophytes formation at the olecranon and coronoid tip as well as their corresponding fossae. Herein, we present another distinct pathology in these patients: the formation of an exostosis at the posterolateral aspect of the elbow.MethodsBetween April 2016 and May 2020, 12 athletes with boxer elbow and handball goalkeeper elbow (mean age of 22 years) suffering from elbow pain were enrolled in the present study. Plain radiography, magnetic resonance imaging (MRI), and computer tomography (CT) scans were used to evaluate the bone conformation of the posterolateral aspect of the elbow. Assessment and staging of the ossification was performed by two independent fellowship-trained elbow surgeons.ResultsBone marrow edema of the posterior aspect of the elbow at the origin of the anconeus muscle was initially detected in MRI scans. With the progression of the condition, imaging revealed an ossification posterior to the capitellum with bony bridges. In the advanced stage of the disease, the exostoses was unstable as the ossification had no adherence to the posterior capitellum during surgical excision. Plain radiographs are limited in their ability to detect the condition, whereas MRI and CT scans allow to identify a signal enhancement at the posterolateral aspect of the elbow.ConclusionIn patients without history of elbow trauma, bony irregularities of the posterior aspect of the capitellum may indicate ossification of the posterolateral aspect of the elbow, most likely caused by repetitive hyperextensions.

Characteristics of Repetitive Nerve Stimulation (Rns) and Correlation with Severity and Quality of Life of Myasthenia Gravis Patients

Background: Myasthenia gravis is a rare autoimmune disease due to neuromuscular junction (NMJ) disorders. The diagnosis of myasthenia gravis is based on cardinal clinical symptoms, including fluctuating weakness, worsening with activity, and improving with rest. In addition to clinical signs and antibody tests, other tests that are also crucial for diagnosis are electrodiagnostic examination (EDX) such as repetitive nerve stimulation (RNS) and single fibre electromyography (SFEMG). Recent studies have focused on assessing patients' severity and quality of life, essential for determining the prognosis and subsequent treatment plans. Objective: To evaluate the characteristic of RNS and its correlation with rigor and quality of life of myasthenia gravis patients. Methods: Inclusion criteria: patients diagnosed with myasthenia gravis, aged 18-65 years, willing to participate in the study. Exclusion criteria include a history of neuropathy, motor neuron disease, or myopathy and dropping out of the study. Patient demographic data were collected. The results of the RNS examination were divided into two categories, normal and abnormal. MG severity was assessed by the Myasthenia gravis foundation of America (MGFA) classification, and the patient's quality of life was assessed by Myasthenia Gravis Quality of Life 15 (MG-QOL 15). Results: Of the 24 samples, 69.1% of RNS were positive. The most sensitive muscle for assessing RNS is the anconeus muscle, followed by the trapezius and nasal. There was no significant relationship between RNS features and severity and the quality of life of myasthenic Gravis patients. Conclusion: Onconeus muscle is the best location for assessing RNS. Although the number of patients with normal RNS had lower severity and better quality of life, there was no statistically significant relationship. Further studies with larger samples and longer follow-ups are needed.

Gross anatomical description of the extrinsic and intrinsic scapular and brachial muscles of Sapajus apella (Linnaeus, 1758).

The robust brown capuchin monkey (Sapajus apella) is a South American primate with preferences for arboreal locomotion, which requires specific thoracic limb muscle adaptations. The present investigation studied the gross anatomy of the extrinsic and intrinsic scapular and brachial muscles. Gross dissections were performed in both thoracic limbs of four formaldehyde-fixed specimens. Three rhomboideus muscles were present (capitis, cervicis, and thoracis). The trapezius muscle was divided into two parts (cervicis and thoracis). The pectoralis abdominalis and omotransversarius muscles were present. The anconeus muscle was found as an individual muscle or fused to the caput mediale of the triceps brachii muscle. The brachialis muscle had among one and two heads. The anconeus epitrochlearis was absent. These muscles of Sapajus apella are adapted for arboreal locomotion and some terrestrial habits, since these have many similarities with other primates with a similar locomotor patterns.

"Safe dissection parameters of the anconeus rotational flap for soft tissue coverage at the elbow".

The anconeus is a small muscle located on the posterior elbow originating on the lateral epicondyle and inserting onto the proximal-lateral ulna that functions as an elbow extensor as well as dynamic stabilizer. The blood supply is tri-fold: medial/middle collateral artery (MCA), recurrent posterior interosseous artery (RPIA), and less commonly found, the posterior branch of the radial collateral artery. The anconeus has become a popular option for local soft tissue coverage about the elbow (distal triceps, olecranon, proximal forearm). The average defect size for consideration of local anconeus flap coverage is 5-7cm2. The aim of the study was to determine safe dissection parameters of the anconeus as well as map arterial pedicles to achieve successful local harvest of the muscle without devascularization. 8 fresh frozen cadaveric arms (all male, average age 63 years - 4 left arms, 4 right arms) from scapula to fingertip were obtained. First, the radial, ulnar and axillary arteries were dissected and isolated. The radial and ulnar arteries were transected. 100cc normal saline was injected through the axillary artery, sequentially clamping the radial followed by the ulnar artery so that adequate flow could be seen through all vessels. 100cc mixture of Biodür and hardener (10:1) was mixed and injected into the axillary artery. We first allowed free flow through both the ulnar and radial vessels followed by clamping of these vessels. This allowed the pressure to build up and fill the smaller vessels in the arms. After injection, the axillary artery was then clamped and the specimens were left to harden for 24-48 h. After hardening, dissection was performed by making a curvilinear incision centred over the lateral epicondyle. The anconeus was identified and the interval between the anconeus and ECU was then confirmed. Measurements of the anconeus muscle were taken. Blunt dissection was carried between anconeus and ECU until the RPIA was identified and protected. We isolated the MCA by dissecting proximally. This was found to run with the nerve to the anconeus. Once this vessel had been protected, the muscle reflected from distal to proximal staying along its ulnar border. The branches of the RPIA were ligated and the dissection was continued proximally. Measurements of the distances of the RPIA, MCA were taken. The average distance of olecranon to muscle tip was 95.0mm. The average distance of lateral epicondyle (LE) to muscle tip was 90.8mm. The average distance of LE to olecranon was 49.8mm. The average location of the RPIA was 63.mm when measuring LE to vessel, 68.3mm when measuring olecranon to vessel, 18.3mm when measuring RPIA to muscle tip. The average RPIA diameter was 1.1mm and length was 36.4mm from the initial branching of the posterior interosseous artery. The average MCA diameter was 0.7mm. The posterior branch of the radial collateral artery was only found in 3/8 specimens. The RPIA and MCA were constant in all specimens. Dissection was safely carried to the border of the LE and olecranon without disruption of the MCA. Our conclusions determined that if dissection of the anconeus is undertaken, the RPIA remains constant between the interval of the ECU as well as anconeus at an average distance of 18.3mm from the tip of the muscle measuring proximally; moreover, the MCA was constant in all specimens found directly between the LE and olecranon always running with the nerve to the anconeus. When dissecting and mobilizing to ensure preservation of the MCA, dissection should be taken from distal to proximal as well as dissecting along the ulnar border of the anconeus. Proximal dissection can be taken as proximal as the border of the LE and olecranon as that did not disrupt MCA blood supply.