Ultrasonographic evaluation of ulnar nerve morphology in patients with ulnar nerve instability.

INTRODUCTION/AIMS: Ulnar nerve instability (UNI) in the retroepicondylar groove is described as nerve subluxation or dislocation. In this study, considering that instability may cause chronic ulnar nerve damage by increasing the friction risk, we aimed to examine the effects of UNI on nerve morphology ultrasonographically. METHODS: Asymptomatic patients with clinical suspicion of UNI were referred for further clinical and ultrasonographic examination. Based on ulnar nerve mobility on ultrasound, the patients were first divided into two groups: stable and unstable. The unstable group was further divided into two subgroups: subluxation and dislocation. The cross-sectional area (CSA) of the nerve was measured in three regions relative to the medial epicondyle (ME). RESULTS: In the ultrasonographic evaluation, UNI was identified in 59.1% (52) of the 88 elbows. UNI was bilateral in 50% (22) of the 44 patients. Mean CSA was not significantly different between groups. A statistically significant difference in ulnar nerve mobility was found between the group with CSA of <10 versus ≥10 mm2 (p = .027). Nerve instability was found in 85.7% of elbows with an ulnar nerve CSA value of ≥10 mm2 at the ME level. DISCUSSION: The probability of developing neuropathy in patients with UNI may be higher than in those with normal nerve mobility. Further prospective studies are required to elucidate whether asymptomatic individuals with UNI and increased CSA may be at risk for developing symptomatic ulnar neuropathy at the elbow.

An assessment of co-contraction in reinnervated muscle.

Aim: To investigate co-contraction in reinnervated elbow flexor muscles following a nerve transfer. Materials & methods: 12 brachial plexus injury patients who received a nerve transfer to reanimate elbow flexion were included in this study. Surface electromyography (EMG) recordings were used to quantify co-contraction during sustained and repeated isometric contractions of reinnervated and contralateral uninjured elbow flexor muscles. Reuslts: For the first time, this study reveals reinnervated muscles demonstrated a trend toward higher co-contraction ratios when compared with uninjured muscle and this is correlated with an earlier onset of muscle fatigability. Conclusion: Measurements of co-contraction should be considered within muscular function assessments to help drive improvements in motor recovery therapies.

Versatility of the double fascicular transfer in reconstruction of elbow flexion paralysis: Intermediate term follow-up and patient-related outcome measures.

OBJECTIVES: The use of fascicle transfers in the reconstruction of traumatic brachial plexus injury is well established, but limited evidence is available regarding their use in atraumatic elbow flexion paralysis. This retrospective case review aimed to verify whether median and ulnar fascicle transfers are similarly effective in atraumatic versus traumatic elbow flexion paralysis when measured using the British Medical Research Council (MRC) scale, Brachial plexus Assessment Tool (BrAT) and Stanmore Percentage of Normal Elbow Assessment (SPONEA) scores at long-term follow-up. METHODS: All median and ulnar fascicle transfer cases performed at the Queen Elizabeth Hospital Birmingham between August 2007 and November 2018 were reviewed to compare the outcomes of transfers performed for traumatic and atraumatic indications. Data on patient demographics, mechanism and nature of injury, date of injury or symptom onset, date of operation, and other nerve transfers performed were collected. Outcome measures collected included the British MRC scale and two patient-reported outcome measures (PROMs), BrAT and SPONEA. RESULTS: In total, 34 patients with 45 median and ulnar fascicle transfers were identified. This included 27 traumatic and seven atraumatic brachial plexus insults. Thirty patients had sufficient follow-up to be included in MRC analysis and 17 patients had sufficient follow-up to be included in PROM analysis. No significant differences were found between traumatic and atraumatic subgroups for median MRC, BrAT, or SPONEA scores. CONCLUSIONS: This study suggests that nerve transfers might be considered effective reconstructive options in atraumatic pathology and provides validation for further research on the subject.

Brain plasticity and age after restoring elbow flexion with distal nerve transfers in neonatal brachial plexus palsy and nonneonatal traumatic brachial plexus injury using the plasticity grading scale.

OBJECTIVE: Ulnar and/or median nerve fascicle to musculocutaneous nerve (MCN) transfers are used to restore elbow flexion following severe neonatal and nonneonatal brachial plexus injuries (BPIs). Restoring volitional control requires plastic changes in the brain. To date, whether the potential for plasticity is influenced by a patient's age remains unknown. METHODS: Patients who had presented with a traumatic upper (C5-6 or C5-7) BPI were divided into two groups: neonatal brachial plexus palsies (NBPPs) and nonneonatal traumatic BPIs (NNBPIs). Both groups underwent ulnar or median nerve transfers to the MCN for elbow flexion restoration between January 2002 and July 2020. Only those who attained a British Medical Research Council strength rating of 4 were reviewed. The primary comparison between the two groups was the plasticity grading scale (PGS) score to determine the level of independence of elbow flexion (target) from forearm motor muscle movement (donors). The authors also assessed patient compliance with rehabilitation using a 4-point Rehabilitation Quality Scale. Bivariable and multivariable analyses were used to identify intergroup differences. RESULTS: In total, 66 patients were analyzed: 22 with NBPP (mean age at surgery 10 months) and 44 with NNBPI (age range at surgery 3-67 years, mean 30.2 years; mean time to surgery 7 months, p < 0.001). All NBPP patients obtained a PGS grade of 4 at the final follow-up versus just 47.7% of NNBPI patients (mean 3.27, p < 0.001). On ordinal regression analysis, after nature of the injury was excluded because of excessive collinearity with age, age was the only significant predictor of plasticity (ß = -0.063, p = 0.003). Median rehabilitation compliance scores were not statistically different between the two groups. CONCLUSIONS: The extent of plastic changes that occur for patients to regain volitional control over elbow flexion after upper arm distal nerve transfers following BPI is influenced by patient age, with complete plastic rewiring more likely in younger patients and virtually ubiquitous in infants. Older patients should be informed that elbow flexion after an ulnar or median nerve fascicle transfer to the MCN might require simultaneous wrist flexion.

Correlation between Elbow Flexor Muscle Strength and Needle Electromyography Parameters after Musculocutaneous Nerve Injury.

OBJECTIVES: To explore the changes of elbow flexor muscle strength after musculocutaneous nerve injury and its correlation with needle electromyography (nEMG) parameters. METHODS: Thirty cases of elbow flexor weakness caused by unilateral brachial plexus injury (involving musculocutaneous nerve) were collected. The elbow flexor muscle strength was evaluated by manual muscle test (MMT) based on Lovett Scale. All subjects were divided into Group A (grade 1 and grade 2, 16 cases) and Group B (grade 3 and grade 4, 14 cases) according to their elbow flexor muscle strength of injured side. The biceps brachii of the injured side and the healthy side were examined by nEMG. The latency and amplitude of the compound muscle action potential (CMAP) were recorded. The type of recruitment response, the mean number of turns and the mean amplitude of recruitment potential were recorded when the subjects performed maximal voluntary contraction. The quantitative elbow flexor muscle strength was measured by portable microFET 2 Manual Muscle Tester. The percentage of residual elbow flexor muscle strength (the ratio of quantitative muscle strength of the injured side to the healthy side) was calculated. The differences of nEMG parameters, quantitative muscle strength and residual elbow flexor muscle strength between the two groups and between the injured side and the healthy side were compared. The correlation between elbow flexor manual muscle strength classification, quantitative muscle strength and nEMG parameters was analyzed. RESULTS: After musculocutaneous nerve injury, the percentage of residual elbow flexor muscle strength in Group B was 23.43% and that in Group A was 4.13%. Elbow flexor manual muscle strength classification was significantly correlated with the type of recruitment response, and the correlation coefficient was 0.886 (P<0.05). The quantitative elbow flexor muscle strength was correlated with the latency and amplitude of CMAP, the mean number of turns and the mean amplitude of recruitment potential, and the correlation coefficients were -0.528, 0.588, 0.465 and 0.426 (P<0.05), respectively. CONCLUSIONS: The percentage of residual elbow flexor muscle strength can be used as the basis of muscle strength classification, and the comprehensive application of nEMG parameters can be used to infer quantitative elbow flexor muscle strength.

Management of Adult Traumatic Brachial Plexus Injury.

Brachial plexus injury is not uncommon in our country like Bangladesh and it causes functional damage and physical disability of the upper limbs. Most of the cases were caused by motor vehicle accident. We have conducted a prospective study for the operative treatment of 105 adult traumatic brachial plexus injury cases in Hand unit in the department of Orthopaedics, Bangabandhu Sheikh Mujib Medial University (BSMMU) during January 2012 to July 2019. The main surgical options for brachial plexus injury include primary reconstructive surgery such as neurolysis, direct repair, nerve graft, nerve transfer (neurotization) and possibly free functioning (gracilis) muscle transfer and secondary reconstructive procedure such as tendon transfer, arthrodesis, FFMT and bony procedure. Each of these procedures is used either alone or in combination for particular clinical scenarios. Aims and objectives of this study was to restoration of shoulder abduction and external rotation, elbow flexion and hand function are goal of treatment of adult traumatic brachial plexus injury. Age range was from 14 years to 55 years (mean age 26 years). Male were 95 and female were 10 cases. Time from trauma to surgery was valid 3 months to 9 months. Motor cycle accident was most common mechanism of injury. Upper plexus (C5, C6) injury was 52 cases, extended upper plexus (C5, C6 & C7) injury was 19 cases and global brachial plexus injury was 34 cases. When there is high suspicion of root avulsions, early exploration and reconstruction is indicated. Operate these patients 2-3 months after their injury. In other patients without high suspicion of root avulsion, we routinely perform exploration between 3 to 6 months after injury when no adequate sign of recovery are present. Common reconstructive options are any injury with neuroma in continuity with conductive nerve action potential (NAP): only neurolysis or any injury with nerve rupture or postganglionic neuroma not conducting nerve Action potential (NAP) and good proximal nerve: Direct repair or repair with nerve graft or nerve transfer if possible. Follow up period from 6 months to 6 years. The best results were obtained in C5, C6 and C5, C6 & C7 brachial plexus injury cases. SAN to SSN, Oberlin II and long head triceps motor branch to anterior division of axillary nerve transfer for C5 & C6 injury or upper plexus injury and in addition intercostals nerve to anterior division of axillary nerve and AIN branch of median nerve to ECRB for C5, C6 & C7 (extended upper plexus injury). Extra-plexus and intra-plexus neurotization was done in global brachial plexus injury cases and 5 cases by contra-lateral C7 to median nerve by vascularised ulnar nerve graft and only 2 cases contra-lateral C7 to lower trunk through pre spinal or pre tracheal route were done and only one case by FFMT. Few cases gain shoulder abduction and elbow flexion but no improvement of hand function and most cases even by FFMT still in follow up. Results of surgical treatment of upper and extended upper brachial plexus injury cases were satisfactory on the other hand recovery of shoulder abduction and elbow flexion was acceptable and comparable to other study in global brachial plexus injury and recovery of hand function were poor.

Assessment of ulnar nerve stability at the elbow by ultrasonography in children.

BACKGROUND: Elbow fractures are common in children. While Kirschner wire (K-wire) is the most commonly used fixation material in children, medial entry pins may be needed for fracture stability. This study aimed to assess ulnar nerve instability by ultrasonography in children. METHODS: We enrolled 466 children aged 2 months to 14 years between January 2019 and January 2020. There were at least 30 patients in each age group. Ulnar nerves were observed under the ultrasound equipment with the elbow fully extended and flexed. If ulnar nerves were subluxated or dislocated, they were considered to have ulnar nerve instability. The children's clinical data, including sex, age, and elbow sides, were analyzed. RESULTS: Of 466 enrolled children, 59 had ulnar nerve instability. Ulnar nerve instability rate was 12.7% (59/466). Instability was prevalent in children aged 0-2 years (P = .001). Among 59 children with ulnar nerve instability, 52.5% (31/59) had bilateral ulnar nerve instability, 16.9% (10/59) had right ulnar nerve instability, and 30.5% (18/59) had left ulnar nerve instability. Logistic analysis of the risk factors of ulnar nerve instability showed no significant difference in terms of sex and left or right ulnar nerve instability. CONCLUSIONS: Ulnar nerve instability correlated with age in children. Children aged <3 years had a low risk of ulnar nerve instability.

Effect of shorter nerve graft and selective motor branch of recipient nerve on nerve transfer surgery for elbow flexion in patients with brachial plexus injury.

OBJECTIVE: The spinal accessory nerve (SAN) is commonly used as a donor nerve for reinnervation of elbow flexors in brachial plexus injury (BPI) reconstruction. However, no study has compared the postoperative outcomes between SAN-to-musculocutaneous nerve (MCN) transfer and SAN-to-nerve to biceps (NTB) transfer. Thus, this study aimed to compare the postoperative time to recovery of elbow flexors between the two groups. METHODS: A total of 748 patients who underwent surgical treatment for BPI between 1999 and 2017 were retrospectively reviewed. Among them, 233 patients were treated with nerve transfer for elbow flexion. Two techniques were used to harvest the recipient nerve: the standard dissection technique and the proximal dissection technique. The postoperative motor power of elbow flexion was assessed every month for 24 months using the Medical Research Council (MRC) grading system. Survival and Cox regression analyses were used to compare the time to recovery (MRC grade ≥ 3) between the two groups. RESULTS: Of the 233 patients who underwent nerve transfer surgery, there were 162 patients in the MCN group and 71 patients in the NTB group. At 24 months after surgery, the MCN group had a success rate of 74.1%, and the NTB group had a success rate of 81.7% (p = 0.208). When compared with the MCN group, the NTB group had a significantly shorter median time to recovery (19 months vs 21 months, p = 0.013). Only 11.1% of patients in the MCN group regained MRC grade 4 or 5 motor power 24 months after nerve transfer surgery compared with 39.4% patients in the NTB group (p < 0.001). Cox regression analysis showed that the SAN-to-NTB transfer in combination with the proximal dissection technique was the only significant factor affecting time to recovery (HR 2.33, 95% CI 1.46-3.72; p < 0.001). CONCLUSIONS: SAN-to-NTB transfer in combination with the proximal dissection technique is the preferred nerve transfer option for restoration of elbow flexion in traumatic pan-plexus palsy.

Radial nerve compression: anatomical perspective and clinical consequences.

The radial nerve is the biggest branch of the posterior cord of the brachial plexus and one of its five terminal branches. Entrapment of the radial nerve at the elbow is the third most common compressive neuropathy of the upper limb after carpal tunnel and cubital tunnel syndromes. Because the incidence is relatively low and many agents can compress it along its whole course, entrapment of the radial nerve or its branches can pose a considerable clinical challenge. Several of these agents are related to normal or variant anatomy. The most common of the compressive neuropathies related to the radial nerve is the posterior interosseus nerve syndrome. Appropriate treatment requires familiarity with the anatomical traits influencing the presenting symptoms and the related prognoses. The aim of this study is to describe the compressive neuropathies of the radial nerve, emphasizing the anatomical perspective and highlighting the traps awaiting physicians evaluating these entrapments.

Risk of nerve injury during elbow arthroscopy: ultrasonographic evaluation of preoperative patients.

BACKGROUND: To clarify the real risk of nerve injury during elbow arthroscopy, the distances of the radial and median nerves to the elbow joint were investigated using ultrasonography in patients who underwent surgery. METHODS: A total of 35 patients who underwent arthroscopic surgery of the elbow were investigated. The distances of the nerves to the capsule and bony landmarks were measured using ultrasonography. The radial nerve distances were measured at the capitellum, joint space, radial head, and radial neck levels. The median nerve distances were measured at the trochlear, joint space, and coronoid process levels. The patients were divided into 2 groups: nine patients in the hydrarthrosis (HA) group and 26 patients in the non-hydrarthrosis (non-HA) group. HA was defined as the intra-articular effusion on magnetic resonance imaging scans. RESULTS: The radial nerve ran closer to the capsule at the radial neck level in the HA group than in the non-HA group (2.0 mm vs. 5.9 mm, P < .01). In the non-HA group, the radial nerve ran closer to the radial head than in the HA group (6.3 mm vs. 8.5 mm, P = .01). The median nerve ran closer to the capsule at the trochlear level in the HA group than in the non-HA group (5.2 mm vs. 8.8 mm, P < .01). Nerves at a distance of ≤2 mm from the capsule were found in 7 patients at the radial neck of the radial nerve and in 2 patients at the trochlear region of the median nerve in the HA group. In the non-HA group, they were found in 3 patients at the radial head and in 1 patient at the joint space of the radial nerve. CONCLUSIONS: The dangerous locations for nerve injury during elbow arthroscopy vary according to hydrarthrosis, and this risk should be recognized during arthroscopic surgery.

Outcomes of gracilis free-flap muscle transfers and non-free-flap procedures for restoration of elbow flexion: A systematic review.

PURPOSE: Elbow flexion is one of the most important functions to restore following brachial plexus damage. The authors sought to systematically review available evidence to summarize outcomes of free gracilis and non-free muscle transfers in restoring elbow flexion. METHODS: MEDLINE, EMBASE, and Cochrane were searched to identify articles reporting on elbow flexion reanimation in terms of transfer failure rates, strengths, range of motion (ROM), and/or Disabilities of the Arm, Shoulder and Hand (DASH) scores. A systematic review was chosen to select studies and reported according to PRISMA guidelines. RESULTS: Forty-six studies met the inclusion criteria for this study. A total of 432 cases were gracilis free-flap muscle transfers (FFMT), and 982 cases were non-free muscle transfers. FFMT were shown to have higher Medical Research Council (MRC) strength scores than non-free muscle transfer groups. However, 42 studies, totaling 1,266 cases, were useful in evaluating graft failure, showing failure (MRC<3) in 77/419 (∼18.4%) of gracilis free-flap transfers and 215/847 (∼25.4%) of non-free muscle transfers. Sixteen articles, 285 cases, were useful to evaluate ROMs (total range: 0-140°), and eight articles, 215 cases, provided DASH scores (total range: 8-90.8). CONCLUSIONS: Of patients who underwent gracilis FFMT procedures, higher mean strength scores and lower failure rates were observed when compared with non-free muscle transfers. Articles reporting non-free muscle transfer procedures (pectoralis, pedicled, Steindler, vascularized ulnar nerve grafts, Oberlin, single/double nerve transfers) provided comprehensive insight into outcomes and indicated that they may result in pooerer poorer DASH scores and ROM.

Mass effect of the distal triceps brachii muscle on ulnar nerve movement during elbow flexion.

INTRODUCTION/AIMS: Hypertrophic triceps brachii contributes to ulnar nerve movement, but the location of the mass effect of the triceps brachii muscle is not known. In this study we aimed to determine the mass effect of the distal medial head of the triceps brachii (DMTB) muscle on ulnar nerve movement. METHODS: In 48 arms, movement of the ulnar nerve at the medial epicondyle and muscle thickness (medial and long head of the triceps brachii [MLTB], medial head of the triceps brachii [MTB], DMTB, and biceps brachii [BB]) were measured using ultrasonography. RESULTS: Ulnar nerve movement at the elbow was consistently correlated with the DMTB muscle thickness (horizontal ulnar nerve movement at the elbow [HM] / vertical ulnar nerve movement at the elbow [VM] with 90° elbow flexion: r = 0.668 / r = 0.313, HM/VM with full elbow flexion: r = 0.481 / r = 0.391). With multiple linear regression, the DMTB was the most important muscle with regard to contribution of thickness to ulnar nerve movement. Individuals with partial and complete dislocation showed a thicker DMTB than those without dislocation. DISCUSSION: Our data suggest that the mass effect of the triceps brachii muscle is exerted primarily by its distal portion. When ulnar nerve dislocation is observed, thickness and anatomical variation of DMTB in the retrocondylar area during elbow flexion should be assessed.

Optimal Donor Nerve to Restore Elbow Flexion After Traumatic Brachial Plexus Injury: A Systematic Review and Meta-Analysis.

BACKGROUND: Traumatic brachial plexus injuries (BPIs) often lead to devastating upper extremity deficits. Treatment frequently prioritizes restoring elbow flexion through transfer of various donor nerves; however, no consensus identifies optimal donor nerve sources. OBJECTIVE: To complete a meta-analysis to assess donor nerves for restoring elbow flexion after partial and total BPI (TBPI). METHODS: Original English language articles on nerve transfers to restore elbow flexion after BPI were included. Using a random-effects model, we calculated pooled, weighted effect size of the patients achieving a composite motor score of ≥M3, with subgroup analyses for patients achieving M4 strength and with TBPI. Meta-regression was performed to assess comparative efficacy of each donor nerve for these outcomes. RESULTS: Comparison of the overall effect size of the 61 included articles demonstrated that intercostal nerves and phrenic nerves were statistically superior to contralateral C7 (cC7; P = .025, <.001, respectively) in achieving ≥M3 strength. After stratification by TBPI, the phrenic nerve was still superior to cC7 in achieving ≥M3 strength (P = .009). There were no statistical differences among ulnar, double fascicle, or medial pectoral nerves in achieving ≥M3 strength. Regarding M4 strength, the phrenic nerve was superior to cC7 (P = .01) in patients with TBPI and the ulnar nerve was superior to the medial pectoral nerve (P = .036) for partial BPI. CONCLUSION: Neurotization of partial BPI or TBPI through the intercostal nerve or phrenic nerve may result in functional advantage over cC7. In patients with upper trunk injuries, neurotization using ulnar, median, or double fascicle nerve transfers has similarly excellent functional recovery.

Palsy of elbow extension.

Elbow extension palsy is generally well tolerated, because when standing up, it is alleviated by gravity. In the case of trunk paralysis or brachial plexus palsy, standing is possible, thus the restoration of active elbow extension improves the hand's positioning above the shoulder, and allows the elbow to be locked in extension, which is necessary during certain activities such as cycling. In these palsy cases, the triceps brachii will be reinnervated by nerve transfers if surgery is performed early enough before irreversible atrophy of the effector muscle sets in. In these situations, secondary tendon transfers are rarely indicated. Few available muscles can be harvested without deleterious consequences on the donor site. Finally, in patients with a very deficient upper limb but with a healthy contralateral limb, when nerve transfers are no longer possible, elbow extension will not be restored. In the tetraplegics using a wheelchair, elbow extension becomes essential for positioning the hand in space and for potentiating the transferable muscles to activate the hand. As nerve transfers have rare indications and are currently being validated in this population, palliative tendon transfers are the reference technique. They must be integrated into an overall upper limb reconstructive surgery program that takes into consideration the potentially usable muscles and the presence of elbow flexion contracture and supination deformity of the forearm. Elbow extension restoration techniques are based on the transfer of two muscles, the posterior deltoid and the biceps brachii. The first is very effective and has very specific requirements, notably good anterior stabilization of the shoulder by the pectoralis major, while the second has broader indications, notably in the case of elbow contracture and inability to stabilize the shoulder anteriorly.

Tendon transfers to restore elbow flexion.

Elbow flexion paralysis is one of most significant deficiencies in the upper limb. When secondary to brachial plexus palsy or nerve trunk lesions, restoration of elbow flexion by means of early nerve surgery or palliative transfers should be part of a comprehensive treatment plan. Tendon transfers are indicated in long-standing palsies, in those who are poor candidates for nerve surgery or when the results of nerve surgery are inadequate. A regional pedicled muscle transfer is performed if available. In this case, a "strong" donor is preferred (pectoralis major with pectoralis minor transfer, triceps brachii to biceps brachii transfer, or bipolar latissimus dorsi transfer). A "weak" transfer is indicated in patients who have incomplete recovery of elbow flexion (MRC 2 strength): isolated pectoralis minor transfer, medial epicondylar muscle transfer according to Steindler technique, or advancement of biceps brachii tendon on forearm. When no donor muscle is available, a free reinnervated muscle transfer may be indicated if age and nerve regeneration conditions are favorable.

Total Denervation of the Elbow: Cadaveric Feasibility Study.

PURPOSE: Total elbow arthroplasty for the treatment of patients with severe elbow osteoarthritis is associated with postoperative activity limitations and risk of midterm complications. Elbow denervation could be an attractive therapeutic option for young, active patients. The aim of our study was to assess the feasibility of selective total elbow denervation via 2 anteriorly based approaches. METHODS: Selective total elbow denervation was performed in 14 cadaver elbows by 2 fellowship-trained elbow surgeons. Lateral and medial approaches to the elbow were used. The length of skin incisions and the minimum distance between them were noted. The number of articular branches identified and their respective distances from the lateral or medial epicondyle of the humerus were recorded. RESULTS: The anterolateral and anteromedial approaches allowed for the identification of all mixed and sensory nerves in all 14 cases. The mean number of resultant articular branches per cadaver was 1 for the musculocutaneous nerve, 2 (range, 1-3) for the radial nerve, 1 (range, 1-3) for the posterior cutaneous nerve of the forearm, 2 (range, 1-3) for the ulnar nerve, and 2 (range, 1-3) for the medial antebrachial cutaneous nerve; the collateral ulnar nerve was connected directly to the capsule. The length of the medial and lateral incisions was 15 cm (range, 12-18 cm) and 12 cm (range, 10-16 cm), respectively. The mean minimum distance between the incisions was 7.5 cm (range, 6.7-8.5 cm). CONCLUSIONS: The findings suggest that selective elbow denervation via 2 approaches is feasible. CLINICAL RELEVANCE: Selective elbow denervation via 2 approaches is feasible. Surgeons should target the articular branches of the musculocutaneous, radial, ulnar, and collateral ulnar nerves, posterior cutaneous nerve of the forearm, as well as medial antebrachial cutaneous nerves when carrying out this procedure.

Just noticeable differences for elbow joint torque feedback.

Joint torque feedback is a new and promising means of kinesthetic feedback imposed by a wearable device. The torque feedback provides the wearer temporal and spatial information during a motion task. Nevertheless, little research has been conducted on quantifying the psychophysical parameters of how well humans can perceive external torques under various joint conditions. This study aims to investigate the just noticeable difference (JND) perceptual ability of the elbow joint to joint torques. The paper focuses on the ability of two primary joint proprioceptors, the Golgi-tendon organ (GTO) and muscle spindle (MS), to detect elbow torques, since touch and pressure sensors were masked. We studied 14 subjects while the arm was isometrically contracted (static condition) and was moving at a constant speed (dynamic condition). In total there were 10 joint conditions investigated, which varied the direction of the arm's movement and the preload direction as well as torque direction. The JND torques under static conditions ranged from 0.097 Nm with no preload to 0.197 Nm with a preload of 1.28 Nm. The maximum dynamic JND torques were 0.799 Nm and 0.428 Nm, when the arm was flexing and extending at 213 degrees per second, respectively.

Volumetric MRI is a promising outcome measure of muscle reinnervation.

The development of outcome measures that can track the recovery of reinnervated muscle would benefit the clinical investigation of new therapies which hope to enhance peripheral nerve repair. The primary objective of this study was to assess the validity of volumetric Magnetic Resonance Imaging (MRI) as an outcome measure of muscle reinnervation by testing its reproducibility, responsiveness and relationship with clinical indices of muscular function. Over a 3-year period 25 patients who underwent nerve transfer to reinnervate elbow flexor muscles were assessed using intramuscular electromyography (EMG) and MRI (median post-operative assessment time of 258 days, ranging from 86 days pre-operatively to 1698 days post- operatively). Muscle power (Medical Research Council (MRC) grade) and Stanmore Percentage of Normal Elbow Assessment (SPONEA) assessment was also recorded for all patients. Sub-analysis of peak volitional force (PVF), muscular fatigue and co-contraction was performed in those patients with MRC > 3. The responsiveness of each parameter was compared using Pearson or Spearman correlation. A Hierarchical Gaussian Process (HGP) was implemented to determine the ability of volumetric MRI measurements to predict the recovery of muscular function. Reinnervated muscle volume per unit Body Mass Index (BMI) demonstrated good responsiveness (R2 = 0.73, p < 0.001). Using the temporal and muscle volume per unit BMI data, a HGP model was able to predict MRC grade and SPONEA with a mean absolute error (MAE) of 0.73 and 1.7 respectively. Muscle volume per unit BMI demonstrated moderate to good positive correlations with patient reported impairments of reinnervated muscle; co- contraction (R2 = 0.63, p = 0.02) and muscle fatigue (R2 = 0.64, p = 0.04). In summary, volumetric MRI analysis of reinnervated muscle is highly reproducible, responsive to post-operative time and demonstrates correlation with clinical indices of muscle function. This encourages the view that volumetric MRI is a promising outcome measure for muscle reinnervation which will drive advancements in motor recovery therapy.

Bilateral brachial artery infiltration by tumoral calcinosis: A case report.

We, herein, presented a rare case of bilateral brachial artery infiltration by tumoral calcinosis located on both elbows. A 58-yearold man presented with a history of painless, palpable solid mass restricting the range of motion of both elbows. These masses were located on the anterior aspect of the elbows and gradually enlarged. After clinical, laboratory and radiological examinations, tumoral calcinosis was suspected, and excisional biopsy was planned for a definite diagnosis. Surgery was first performed on the left elbow. The median nerve was found to be compressed but not infiltrated by the mass. Interestingly, the brachial artery was totally infiltrated throughout the entire mass. Occlusion was observed in the brachial artery located within the mass. The tumor on the left elbow, 8.5 × 5.5 × 2.5 cm in size, was totally excised with approximately 12-cm brachial artery segment. The artery was resected until the healthy tissue was reached. The defect was reconstructed with saphenous vein graft obtained from the ipsilateral lower extremity. The same surgical procedure was performed on the right elbow after 3 months. The tumor size on the right elbow was 7 × 3.5 × 1.7 cm. Approximately 15-cm brachial artery segment was excised, and the defect was reconstructed with saphenous vein graft. Tumoral calcinosis is a rare benign condition that can be located in close relationship with neurovascular structures. In such cases, detailed neurologic and vascular examination, including imaging modalities, for arterial flow is essential to establish a more accurate surgical plan and avoid any unexpected situation during surgery.

The anconeus muscle revisited: double innervation pattern and its clinical implications.

PURPOSE: The aim of the present study is to describe in detail the morphology and innervation pattern of the anconeus muscle, bearing in mind clinical implications such as iatrogenic injuries during surgical elbow approaches. METHODS: A cadaveric study was performed; 56 elbows from 28 formalin-fixed cadavers belonging to the Anatomy Department of Universidad Complutense of Madrid were dissected. The triceps-anconeus nerve was located and dissected. A second innervation to the anconeus muscle from a branch of the posterior interosseous nerve (PIN) was occasionally detected. Taking the lateral epicondyle as a landmark, the entry points of both nerves in the muscle were referenced, the triceps-anconeus nerve was referenced at 0°, 30°, 45°, 70° and 90° of elbow flexion, and the PIN branch at 0°. RESULTS: Anconeus muscle was present in all specimens. The triceps-anconeus nerve was present in all of the dissected elbows. A branch from PIN to the anconeus muscle was present in 38 of the 54 elbows (70.4%). There were statistically significant differences in all measurements regarding the specimens' gender, being higher for men. CONCLUSIONS: There is evidence of a high frequency of a double innervation pattern for the anconeus muscle: the main branch of triceps-anconeus muscle depending on the radial nerve, which is liable to being damaged during posterior elbow approaches, and a secondary branch depending on the PIN. There are very few references to this finding in Anatomical literature and none with such a large sample size.