Restoration Of Elbow Flexion Research Articles

Factors Affecting Outcomes After Free Functional Gracilis Muscle Transfer for Elbow Flexion in Brachial Plexus Injury: A Systematic Review and Meta-Analysis

Free functional gracilis transfer (FFGT) is a useful option for reconstruction of elbow flexion following brachial plexus injury presenting late or with poor outcomes from previous nerve surgery. In this systematic review and meta-analysis, we aimed to investigate variables associated with superior outcomes. The efficacy of single versus double FFGT, where the first FFGT is performed to restore elbow flexion, and the choice of donor nerve for neurotization were evaluated. A meta-analysis was conducted, including studies that provided postoperative Medical Research Council (MRC) grade for elbow flexion, Disabilities of the Arm, Shoulder, and Hand and visual analog scale scores, quantitative elbow flexion strength, and range of motion. A random effects meta-regression analysis was performed to identify factors associated with improved outcomes. Thirty-seven studies, with 1,607 patients, were analyzed. Single FFGT was reported in 34 studies (n= 1,398), and double FFGT was reported in 10 studies (n= 209). The mean follow-up duration was 37.3 ± 21.1 months. Following single FFGT, 75.4% and 48.9% achieved MRC grades ≥3 and ≥4, respectively. Following double FFGT, 100% achieved an MRC grade ≥3 and 62.7% ≥4. The likelihood of achieving M3 and M4 was significantly greater for double FFGT. Overall, FFGT innervated by the spinal accessory nerve had significantly better recovery of MRC grade ≥3. When comparing only single and double FFGT innervated by spinal accessory nerve, there was no significant difference in recovery of elbow flexion. The meta-regression analysis showed a significant negative correlation between the patient's age and the probability of achieving an MRC grade of ≥3 and4. In the overall analysis encompassing all innervating nerves, double FFGT was superior to single FFGT. Subgroup analysis of single and double FFGT innervated by the spinal accessory nerve showed no significant difference. Increasing age was a significant risk factor for poorer outcomes. Therapeutic IV.

Triceps-to-Biceps Tendon Transfer Technique for Restoration of Elbow Flexion in Adult Brachial Plexus Injury.

Restoration of elbow flexion is a priority in treating adult traumatic brachial plexus injuries. A tendon transfer is an ideal option for patients not candidates for reconstructive nerve surgery or free-functioning muscle transfer. For patients with a partial brachial plexus injury or a pan plexus injury with adequate recovered triceps function and loss of elbow flexion, a triceps-to-biceps tendon transfer is a nonmicrosurgical option to restore elbow flexion. The technique of triceps-to-biceps transfer in which the complete triceps tendon is transferred laterally, secured lateral to the radial tuberosity, and reinforced with suture to the biceps tendon is described.

Preoperative Evaluation for Free Functional Muscle Transfer in Upper Extremity Amyoplasia: A Multicenter Report of 3 Cases.

A multicenter series of 3 patients with amyoplasia of the upper extremity were indicated for gracilis free functional muscle transfer (FFMT) to restore elbow flexion and found to have an absent gracilis. A final case is discussed detailing standardized evaluation with ultrasound to confirm gracilis before surgical intervention. In amyoplasia, the gracilis muscle may be absent or have fatty infiltration, making this donor muscle inadequate. Preoperative ultrasound to determine the presence of the gracilis is noninvasive and recommended in patients with amyoplasia of the upper extremity being considered for FFMT.

The Outcome of Spinal Accessory Nerve Transfer to the Musculocutaneous Nerve in Birth Brachial Plexus Palsy

Patients with brachial plexus birth injury with limited intraplexal donors require the use of extraplexal donors. Concern regarding the potential for respiratory problems resulting from the harvest of intercostal nerves or the phrenic nerve suggests the need for other options. Transfer of the spinal accessory nerve (SAN) is one option for restoring elbow flexion in adult patients; however, there are few reports of the results of this transfer in brachial plexus birth injury. This study aimed to report the result of SAN transfer to the musculocutaneous nerve (MCN) in brachial plexus birth injury. Patients who had undergone SAN to MCN nerve transfer were included in thisstudy. Patients were classified according to Narakas classification. The chart was reviewed for the time for recovery of elbow flexion according to the Active Movement Scale(AMS). Eleven patients underwent SAN to MCN transfers with interpositional sural nerve grafts. Mean birthweight was 4,070 grams (range: 3,300-4,670). Mean time to operation was 6.5 months (range: 4-10). Of the 11 patients, two were of Narakas type 3, whereas the others were of type 4. One patient did not recover elbow flexion and underwent later tendon transfer, whereas the other 10 patients reached AMS grade M6 recovery. The median time for AMS grade M1 elbow flexion recovery was eight months (interquartile range: 6.2-8.8) and for AMS grade M5 was 26 months (interquartile range: 14.2-36.5). Spinal accessory nerve to MCN transfer with an interposition nerve graft is a viable option for restoring elbow flexion. However, long-term outcomes of this procedure have yet to be fully demonstrated. Case series IV.

Bipolar Pedicled Latissimus Dorsi Flap for Soft-Tissue Coverage and Restoration of Elbow Function

Bipolar latissimus dorsi transfer has been considered a viable option for the restoration of elbow flexion in patients with large traumatic defects of the anterior arm compartment. Advantages of bipolar transfer of the latissimus include stabilization of the anterior shoulder joint in addition to recreating the biceps for a direct line of pull in restoring elbow flexion with minimal donor site morbidity. Previous literature in bipolar latissimus transfer has demonstrated good outcomes in elbow flexion against gravity, range of motion, and patient satisfaction. We present a step-by-step demonstration of a bipolar pedicled latissimus dorsi transfer for restoration of elbow function and soft-tissue coverage for large traumatic defects to the anterior compartment of the arm.

Optimizing donor fascicle selection in Oberlin's procedure: A retrospective review of anatomical variability using intraoperative neuromonitoring.

Transfer of the fascicle carrying the flexor carpi ulnaris (FCU) branch of the ulnar nerve (UN) to the biceps/brachialis muscle branch of the musculocutaneous nerve (Oberlin's procedure), is a mainstay technique for elbow flexion restoration in patients with upper brachial plexus injury. Despite its widespread use, there are few studies regarding the anatomic location of the donor fascicle for Oberlin's procedure. Our report aims to analyze the anatomical variability of this fascicle within the UN, while obtaining quantifiable, objective data with intraoperative neuromonitoring (IONM) for donor fascicle selection. We performed a retrospective review of patients at our institution who underwent an Oberlin's procedure from September 2019 to July 2023. We used IONM for donor fascicle selection (greatest FCU muscle and least intrinsic hand muscle activation). We prospectively obtained demographic and electrophysiological data, as well as anatomical location of donor fascicles and post-surgical morbidities. Surgeon's perception of FCU/intrinsic muscle contraction was compared to objective muscle amplitude during IONM. Eight patients were included, with a mean age of 30.5 years and an injury-to-surgery interval of 4 months. Donor fascicle was located anterior in two cases, posterior in two, radial in two and ulnar in two patients. Correlation between surgeon's perception and IONM findings were consistent in six (75%) cases. No long term motor or sensory deficits were registered. Fascicle anatomy within the UN at the proximal arm is highly variable. The use of IONM can aid in optimizing donor fascicle selection for Oberlin's procedure.

188 Timing of Nerve Reconstruction Surgery to Optimize Long-Term Recovery at the Elbow and Forearm in Neonatal Brachial Plexus Palsy

INTRODUCTION: Restoration of elbow flexion is highly prioritized in nerve reconstruction for neonatal brachial plexus palsy (NBPP). Elbow extension and forearm supination are also frequently impacted in NBPP. Timing of surgical reconstruction for optimal outcomes at the elbow and forearm remains unknown. METHODS: We interrogated a prospectively collected database of all children with NBPP who underwent nerve reconstruction at a single center between 2005-2020. AROM was collected for elbow flexion and extension and forearm supination at every clinic visit and normalized between 0 and 1. The cohort was divided into those with surgery =6 months old, 6-9 months old, and >9 months old. We compared elbow and forearm AROM in local age windows between the groups using a regression model expressing the expected AROM as a linear function. Significant differences between the groups were identified using a Wald test. RESULTS: Of 99 included children 28 had surgery =6 months old, 46 had surgery between 6-9 months, and 25 had surgery >9 months. At ∼13 years follow up, there was no difference in recovery of AROM for elbow flexion between the groups. For elbow extension, mean normalized AROM was significantly worse when comparing the >9 month and =6 month group (0.41 vs 0.84, p < 0.001). For forearm supination, the =6 month group had significantly better AROM than the 6-9 month (0.57 vs 0.77, p = 0.02) and >9 month (0.46 vs 0.77, p < 0.001) groups. Children who presented earlier had surgery at a younger age. CONCLUSIONS: Earlier surgery may result in better long-term recovery of elbow extension and surgery =6 months of age may yield the best outcomes for forearm supination. Early referral may help optimize timing of nerve surgery.

Rare median and musculocutaneous nerve fusion with intraoperative electrical confirmation: illustrative case

BACKGROUND Nerve transfer is a surgical technique in which a redundant or expendable fascicle is transferred or coapted to an injured nerve distal to the site of injury for the purpose of reinnervation. Successful nerve transfer is dependent on correct intraoperative identification of donor and recipient nerves. OBSERVATIONS An 8-year-old male was recommended for ulnar nerve fascicle to biceps branch of musculocutaneous nerve transfer to restore elbow flexion weakness after a demyelinating spinal cord injury. The biceps branch was identified approximately midway along the upper arm. Proximal musculocutaneous nerve stimulation induced hand movement and electromyography activity in the median nerve muscles. Neurolysis of the thickened proximal structure revealed fusion of the musculocutaneous and median nerves. Because of the proximity of the median and musculocutaneous nerves, median rather than ulnar nerve fascicles were used as donors for transfer. LESSONS The authors provide the first reported intraoperative finding of an anatomical variant in which the musculocutaneous nerve and median nerve were fused in the upper arm, confirmed through intraoperative electrical stimulation. Surgeons should be aware of this rare anatomical variant to ensure correct nerve identification when performing nerve transfers in the proximal upper extremity.

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.

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. 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. 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 (β = -0.063, p = 0.003). Median rehabilitation compliance scores were not statistically different between the two groups. 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.

Forearm and elbow secondary surgical procedures in neonatal brachial plexus palsy: a systematic scoping review

IntroductionNeonatal Brachial plexus palsy (NBPP) is an injury during delivery that can lead to loss of motor function and limited range of motion in patients due to damage of nerves in the brachial plexus. This scoping review aims to explore types of procedures performed and assess outcomes of forearm and elbow secondary surgery in pediatric patients. MethodsSearches of PubMed, Cochrane, CINAHL, Web of Sciences and Scopus were completed to obtain studies describing surgical treatment of elbow and forearm in pediatric patients with NBPP. 865 abstracts and titles were screened by two independent reviewers resulting in 295 full text papers; after applying of inclusion and exclusion criteria 18 articles were included. The level of evidence of this study is level IV. Results10 main procedures were performed to regain function of the forearm and elbow in neonatal brachial plexus birth palsy patients. Procedures had different aims, with supination contracture (6) and elbow flexion restoration (5) being the most prevalent. The variance between pre-and postoperative soft tissue and bony procedures outcomes decreased and showed improvement with respect to the aim of each procedure category. For soft tissue procedures, a statistically significant increase was found between pre- and postoperative values for active elbow flexion, passive supination, and active supination. For bony procedures, there was a statistically significant decrease between pre- and postoperative values of passive and active supination. ConclusionsOverall, all procedures completed in the assessed articles of this study were successful in their aim. Bony procedures, specifically osteotomies, were found to have a wider range of results, whereas soft tissue procedures were found to be more consistent and reproducible with respect to their outcomes. Bony and soft tissue procedures were found vary in their aims and outcomes. This study indicates the need for further research to augment knowledge about indications and long-term benefits to each procedure.

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.

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. 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. 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). 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.

Surgical management and outcomes of traumatic global brachial plexus injury: A concise review and our center approach.

Global brachial plexus injury (GBPI) mainly affects adults and causes severe life-changing consequences that lead to the deterioration of patients' quality of life. Several surgical approaches have been described and reported in the literature to improve patients' functional ability. A literature review is done on PubMed/MEDLINE and Embase using specific keywords to retrieve relevant articles assessing different surgical approaches for GBPI management. Inclusion and exclusion criteria were applied, and eligible articles were included in the review. The literature survey revealed that various surgical options had been used to manage GBPI patients. In this concise review, we discuss and compare the different surgical approaches related to GBPI and its outcome in terms of restoring elbow flexion and extension, shoulder abduction, and wrist and hand function. The primary surgical intervention relies mainly on transferring single or multiple nerves with/without nerve grafts to restore the function of the targeted muscle. Different techniques using a variety of nerve donors and recipients are compared to assess the functional outcomes of each option. Moreover, further options are addressed for delayed GBPI injuries or failed nerve transfer procedures, as in free functional muscle transfer techniques. In addition, information about brachial plexus injury cases faced in our center is presented along with our center's approach to diagnosing and managing partial and GBPI cases.

Triceps-to-Biceps Tendon Transfer for Restoration of Elbow Flexion in Brachial Plexus Injury

Restoring elbow flexion is a reconstructive priority in patients with brachial plexus injuries. This study aimed to evaluate the results and assess factors contributing to outcomes of triceps-to-biceps tendon transfer in patients presenting with delayed or chronic upper brachial plexus injury. Patients with traumatic brachial plexus injuries undergoing triceps-to-biceps tendon transfer at a single institution's multidisciplinary brachial plexus center between 2001 and 2021 were retrospectively reviewed. The entire triceps tendon was transferred around the lateral aspect of the arm, secured to the radius with a tenodesis button, and reinforced with a side-to-side tendon transfer to the biceps tendon. Primary outcomes include the modified British Medical Research Council (mBMRC) elbow flexion strength and active elbow range of motion. Twelve patients (eight men and four women; mean age, 45.2 years) were included. The mean follow-up was 10.4 (range, 5-34) months. Nine patients achieved mBMRC ≥3. Five patients achieved mBMRC 4. Average active elbow flexion was 119°, with average extension deficit of 11°. There were three patients with unsatisfactory results, achieving mBMRC 2 elbow flexion. Triceps-to-biceps tendon transfer is an excellent tendon transfer option for restoring elbow flexion in certain patients with an adequately functioning triceps muscle, who present with a delayed or chronic brachial plexus injury. Although most patients achieved mBMRC ≥3 elbow flexion, there was an expected permanent loss of elbow active extension with a residual elbow flexion contracture. Therapeutic IV.

Tendon transfer from a re-innervated triceps to the biceps for restoration of elbow flexion in total brachial plexus palsy

ObjectivesThis study aimed to evaluate the outcomes of the tendon transfer from a reinnervated triceps to biceps in the context of total brachial plexus palsy. MethodsWe conducted a retrospective study. Patients had reinnervation of the triceps either by spontaneous recovery or by nerve transfer. Functional results were assessed by strength and range of motion. The level of patient satisfaction was measured on a scale from 0 to 10. ResultsSix patients (6 transfers) were included. Two triceps had spontaneous reinnervation and the other four through neurotization of intercostal nerves. All patients recovered strength to M4 in flexion with an average secondary deficit of 10° (5°–15°). The mean level of satisfaction was measured at 7/10 (6–8). ConclusionsThis tendon transfer is a reliable and simple solution for supportive restoration of elbow flexion. Systematic reinnervation of active extension of the elbow should be proposed for the gain in function that it represents but also for the supportive therapeutic opportunity that it offers should nerve surgery for elbow flexion fail. Level of evidence4.

Optimal Distal Tendon Insertion Point for Elbow Flexion in Free-Functioning Gracilis Muscle Transfer for Panbrachial Plexus Injuries: A Cadaveric Study

Following pan-brachial plexus injuries, restoration of elbow flexion is widely accepted as the reconstructive priority. A gracilis free functioning muscle transfer (FFMT) can be used to restore elbow flexion alone with insertion into the biceps brachii (BIC) or brachioradialis (BRD) tendons or restore combined elbow and finger flexion with a more distal insertion into the flexor digitorum profundus (FDP) tendons. Using cadaveric experiments, we determined the peak instantaneous moment arm for each insertion option. Six simulated gracilis transfer surgeries were performed using both arms of three fresh-frozen full body cadaveric specimens (age: 79 + 10 years. 2 female). The gracilis muscles from both legs were harvested and transferred to the contralateral upper extremity. The elbow was manually moved through three flexion-extension cycles while the instantaneous moment arm was calculated from measurements of gracilis excursion and elbow joint angle for the three distal insertion sites. Peak instantaneous moment arm for all three insertions occurred at an elbow angle between 83° to 92° with a magnitude ranging from 33 mm to 54 mm. The more distal (FDP/BRD) insertions produced a significantly greater (∼1.5 times) peak elbow flexion instantaneous moment arm compared to the BIC insertion. Based on the instantaneous moment arm, the gracilis FFMT distal insertion locations could result in greater reconstructed elbow flexion strength. In addition, direct measurement of the shape and magnitude of the moment arm curve for differing insertion sites allows high resolution surgical planning and model testing. This study presents the first direct experimental quantification of the gracilis FFMT instantaneous moment arm. The experimental evidence supports the use of FDP/BRD insertion locations by providing a quantitative explanation for the increased elbow flexion torque observed clinically in patients with a gracilis FFMT and distal FDP insertion.

Direct measurement of human skeletal muscle specific tension and fiber length

Skeletal muscle’s isometric contractile properties are one of the classic structure-function relationships in all of physiology allowing for extrapolation of single fiber mechanical properties to whole muscle properties based on the muscle’s optimal fiber length and physiological cross-sectional area (PCSA). However, this relationship has only been validated in small animals and then extrapolated to human muscles which are much larger in terms of length and PCSA. We leveraged a unique surgical technique in which an intact, living, human gracilis muscle is transferred from the thigh to the arm, restoring elbow flexion after brachial plexus injury. During this surgery we directly measured subject specific gracilis muscle force-length relationship in situ and properties ex vivo. We hypothesized that the human gracilis would have a functional fiber length of about 23 cm, based on the anatomical literature, and a specific tension of 225 kPa, based on the physiological literature. Data are provided as mean±standard deviation of the mean. Twelve subjects (7 males, average age 54±12 years). In situ passive and active tension were directly measured using a buckle force transducer (BFT) placed on the distal gracilis tendon. Passive tension was measured in each of four joint configurations (JC) prior to muscle stimulation, and, to produce active tension, the anterior branch of the obturator nerve was stimulated. The muscle was progressively lengthened by extending the knee and abducting the hip. Since we could not measure optimal fiber length directly in our subjects during isometric testing we used a functional surrogate for optimal fiber length, the full-width at half-maximum (FWHM) defined from their force vs. length relationship. The FWHM is the width of the active force vs. muscle length curve at half the maximum force. A linear relationship between FWHM and optimal fiber length has been established across several mammalian species and muscles. Thus, to calculate FWHM, we fit each patient’s calculated fully active force vs. muscle length data to a quadratic curve and then calculated width at half the calculated maximum force from the equation. Optimal fiber length was then calculated from the previously established linear relationship between FWHM and optimal fiber length. Each subject’s PCSA was calculated from their muscle volume and optimal fiber length.From these experimental data we established a human muscle fiber-specific tension of 171±84 kPa (n=12). We also determined the average gracilis optimal fiber length was 12.9±3.3 cm (n=12). Surprisingly, these fiber lengths were about half of the previously reported optimal fascicle lengths of 23 cm. Thus, the long gracilis muscle appears to be composed of relatively short fibers acting in parallel that may not have been appreciated based on traditional anatomical methods. We thus suggest that the value of 171 kPa be considered the best current estimate of human muscle specific tension. This work was supported the Department of Veterans Affairs grant 1 I01 RX002462 and, in part, by Research Career Scientist Award Number IK6 RX003351 from the United States (U.S.) Department of Veterans Affairs Rehabilitation R&amp;D (Rehab RD) Service. Pilot projects leading to this protocol were supported by the Shirley Ryan AbilityLab Catalyst Grant Program, National Science Foundation Graduate Research Fellowship under Grant No. 1255833 and the Mayo Clinic Graduate School. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

VATS phrenic nerve harvesting for brachial plexus neurotization: literature review and our experience.

Brachial plexus traumatic lesions often lead to severe upper extremity deficits that dramatically compromise quality of life of mostly young patients. Optimal treatment aims to restore elbow flexion transferring various donor nerves. Phrenic nerve (PN) is a powerful source of transferable axons and, despite supraclavicular sectioning being the most used technique, it can be harvested through video-assisted thoracoscopic surgery (VATS). About PN harvesting, less than 20 articles were found in Literature. Most of them are clinical case-reports or case-series or expert opinions. Most of these studies are from China and East Asia and very rarely from Europe; none from Italy. Therefore, we present our experience in PN VATS harvesting in two patients, first cases reported in Italy. Few papers explore risks and benefits of PN as a donor site for brachial plexus reconstruction. There is no clear consensus in the literature whether a traditional approach or minimally invasive surgery is advisable to harvest PN for neurotization. Currently there's no clear indication nor a definitive contraindication about routine use of PN for surgical treatment of BPTLs, it's mostly a matter of choosing the best donor nerve for every single patient. This choice depends on the patient's characteristics, type of traumatic lesion, time from the traumatic event and on the center's experience. The only real concern about using PN as a donor is the potential loss of pulmonary function. In our center two patients with complete brachial plexus avulsion underwent PN transfer via VATS in 2021. Usually, recovery of muscle function depends on time between injury and surgical repair. A commonly accepted recommendation is to perform surgery within six months from the traumatic lesion12. In our experience, the time between trauma and surgery was five months for patient A and six months for patient B. Even if some authors13 consider previous thoracic trauma with rib fractures a major contraindication for homolateral PN harvesting, we believe that the presence of pleural adhesions should not exclude a patient from surgery. No intra or postoperative complications were observed. Both patients were discharged on IV postoperative day. An intense rehabilitation program within three months after surgery is mandatory and regular follow-up is needed to monitor any improvement. No respiratory symptoms or discomfort is recorded up to now. Nerve transfer is a safe and reliable surgical reconstructive procedure and phrenic nerve, due to its pure motor nature, is a very good donor for brachial plexus injuries14. VATS is a valid procedure to guarantee a much longer nerve, avoiding any graft use, and doesn't seem to determine significant pulmonary function loss. Previous thoracic trauma, rib fractures and pneumothorax are commonly considered contraindications for VATS harvesting. However, a major trauma leading to BPTL often implies homolateral thoracic trauma with or without rib fracture or pneumothorax. This could be a reasonable justification to reconsider those contraindications and extend the potential cohort of patients that could benefit from this technique.

Direct intraoperative measurement of isometric contractile properties in living human muscle.

Skeletal muscle's isometric contractile properties are one of the classic structure-function relationships in all of biology allowing for extrapolation of single fibre mechanical properties to whole muscle properties based on the muscle's optimal fibre length and physiological cross-sectional area (PCSA). However, this relationship has only been validated in small animals and then extrapolated to human muscles, which are much larger in terms of length and PCSA. The present study aimed to measure directly the in situ properties and function of the human gracilis muscle to validate this relationship. We leveraged a unique surgical technique in which a human gracilis muscle is transferred from the thigh to the arm, restoring elbow flexion after brachial plexus injury. During this surgery, we directly measured subject specific gracilis muscle force-length relationship in situ and properties ex vivo. Each subject's optimal fibre length was calculated from their muscle's length-tension properties. Each subject's PCSA was calculated from their muscle volume and optimal fibre length. From these experimental data, we established a human muscle fibre-specific tension of 171kPa. We also determined that average gracilis optimal fibre length is 12.9cm. Using this subject-specific fibre length, we observed an excellent fit between experimental and theorical active length-tension curves. However, these fibre lengths were about half of the previously reported optimal fascicle lengths of 23cm. Thus, the long gracilis muscle appears to be composed of relatively short fibres acting in parallel that may not have been appreciated based on traditional anatomical methods. KEY POINTS: Skeletal muscle's isometric contractile properties represent one of the classic structure-function relationships in all of biology and allow scaling single fibre mechanical properties to whole muscle properties based on the muscle's architecture. This physiological relationship has only been validated in small animals but is often extrapolated to human muscles, which are orders of magnitude larger. We leverage a unique surgical technique in which a human gracilis muscle is transplanted from the thigh to the arm to restore elbow flexion after brachial plexus injury, aiming to directly measure muscles properties in situ and test directly the architectural scaling predictions. Using these direct measurements, we establish human muscle fibre-specific tension of ∼170kPa. Furthermore, we show that the gracilis muscle actually functions as a muscle with relatively short fibres acting in parallel vs. long fibres as previously assumed based on traditional anatomical models.

Restoration of elbow active flexion in children with amyoplasia: What is the better age to do the operation?

BACKGROUND: The absence of active elbow flexion is the most common problem in children with amyoplasia, leading to daily living difficulties. Many variants of muscle transfer are used for the restoration of active elbow flexion. The pectoralis major and latissimus dorsi muscles are the most used muscles for this purpose; however, the optimal age for these operations is not reported in the literature.&#x0D; AIM: This study aimed to determine the optimal age of children with amyoplasia for the restoration of active elbow flexion.&#x0D; MATERIALS AND METHODS: The retrospective study involved 61 patients (90 upper limbs) with amyoplasia (30 [49%] girls and 31 [51%] boys) who were examined and treated between 2011 and 2020. In 46 (51.1%) cases, we used major muscles, and in 44 (48.9%) cases, the latissimus dorsi muscle was used as a donor muscle. All patients were divided into four groups: group 1 included children aged 13 years (n = 17, 27.9%); group 2, 37 years (n = 30, 49.2%); group 3, 711 years (n = 8, 13.1%), and group 4, 1218 years (n = 6, 9.8%). The clinical examination of the patients was conducted before and after the operation (6 months). Statistical data processing was performed using Statistica 10 and SAS JMP 11. To describe the numerical scales, the average value and standard deviation (M SD) were used.&#x0D; RESULTS: The age of the patients at the time of surgery was 5.16 3.72 years, and the postoperative follow-up period was 41.93 30.13 months. Elbow flexion contractures were observed mainly in groups 13 (p 0.05). The greatest changes in indicators such as the strength of forearm flexor muscles, active elbow flexion, and function of the elbow were noted in group 1 (p 0.05). The same postoperative indicators were worse in group 4 than in younger patients (p 0.05). Groups 3 and 4 had less strength of the donor muscles than groups 1 and 2 (p 0.05).&#x0D; CONCLUSIONS: The retrospective analysis of the results of the restoration of active elbow flexion in children with amyoplasia allowed us to recommend these operations in children aged 13 years. The prevention of elbow flexion contractures and the formation of a new stereotype of movement help improve the self-ability of these patients and the treatment results.

Restoring musculocutaneous nerve function in 146 brachial plexus operations – A retrospective analysis

IntroductionA brachial plexus lesion is a devastating injury often affecting young, male adults after traffic accidents. Therefore, surgical restoration of elbow flexion is critical for establishing antigravity movement of the upper extremity. We analyzed different methods for musculocutaneous reconstruction regarding outcome. MethodsWe conducted a retrospective analysis of 146 brachial plexus surgeries with musculocutaneous reconstruction performed at our department from 2013 to 2017. Demographic data, surgical method, donor and graft nerve characteristics, body mass index (BMI) as well as functional outcome of biceps muscle based on medical research council (MRC) strength grades before and after surgery were analyzed. Multivariate analysis was performed using SPSS. ResultsOberlin reconstruction was the procedure performed most often (34.2%, n = 50). Nerve transfer and autologous repair showed no significant differences regarding outcome (p = 0.599, OR 0.644 CI95% 0.126–3.307). In case of nerve transfers, we found no significant difference whether reconstruction was performed with or without a nerve graft (e.g. sural nerve) (p = 0.277, OR 0.619 CI95% 0.261–1.469). Multivariate analysis identifies patient age as a strong predictor for outcome, univariate analysis indicates that nerve graft length > 15 cm and BMI of > 25 could lead to inferior outcome. When patients with early recovery (n = 19) are included into final evaluation after 24 months, the general success rate of reconstructions is 62,7% (52/83). ConclusionReconstruction of musculocutaneous nerve after brachial plexus injury results in a high rate of clinical improvement. Nerve transfer and autologous reconstruction both show similar results. Young age was confirmed as an independent predictor for better clinical outcome. Prospective multicenter studies are needed to further clarify.