Free functional gracilis transfer for reconstruction of isolated anterior deltoid atrophy following surgical proximal humerus fixation.

BACKGROUND: Palsy of the clavicular head of the deltoid is a complication after surgical fixation of proximal humerus fractures. Flexion of the shoulder joint may be impaired as a result. Additionally, patients may complain of joint instability, visible atrophy, and pain. Where nerve reconstruction is not possible, muscle transfers remain as secondary reconstructive procedures. METHODS: Three patients with anterior deltoid palsy after proximal humerus fixation received a free functional gracilis transfer to the shoulder. Postoperatively, patients underwent biofeedback-based rehabilitation. Before and after the intervention, subjective complaints, pain level, and active range of motion (ROM) were recorded. At the final follow-up, patients completed a Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. RESULTS: The surgery was successful in all patients, with first muscle signals registered through surface electromyography approximately four months postoperatively. At the last follow-up (>3 years), the patients showed improved shoulder stability and pain scores. In two patients with preoperative restrictions, active ROM improved. The DASH score showed minimal to no disability in two patients and moderate disability in the third. Two patients voiced satisfaction with the restoration of the ventral bulk of the shoulder. CONCLUSIONS: Free functional gracilis muscle transfer is a novel approach for secondary reconstruction in patients with anterior deltoid atrophy who do not qualify for nerve intervention. It addresses shoulder instability and pain and may improve active ROM. The addition of fresh muscle tissue to the ventral shoulder can improve its natural contour and prevent protrusion of the humeral head.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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 and 4. CONCLUSIONS: 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. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Surgical reconstructions for adult brachial plexus injuries. Part II: Treatments for total arm type.

Brachial plexus injuries (BPI) contribute not only to physical dysfunction but also to socioeconomic aspects and psychological disability. Patients with total arm-type BPI will lose not only the shoulder and elbow function but also the hand function, making reconstruction particularly challenging. Reconstructive procedures commonly include nerve repair, grafting, neurotization (nerve transfer), tendon transfer and free functional muscle transfer (FFMT). Although it is difficult to achieve prehensile hand function, most of patients with total arm-type BPI can be treated with satisfied outcomes. In addition to surgical techniques, comprehensive rehabilitation is another important factor for successful outcomes, and efficient communication can help to boost patient morale and eliminate uncertainty.

Restoring the spontaneous smile through free functional muscle transfer. A systematic review and meta-analysis of the last twenty years' experience.

BACKGROUND: The recovery of the spontaneous smile has become a primary focus in facial reanimation surgery and its major determinant is the selected neurotizer. We aimed to compare the spontaneity outcomes of the most preferred neurotization methods in free functional muscle transfer for long-standing facial paralysis. METHODS: The Embase, Ovid Medline, and PubMed databases were queried with 21 keywords. All clinical studies from the last 20 years reporting the postoperative spontaneity rate for specified neurotization strategies [cross-face nerve graft (CFNG), contralateral facial nerve (CLFN), motor nerve to the masseter (MNM), and dual innervation (DI)] were included. A meta-analysis of prevalence was performed using Freeman-Tukey double arcsine transformation, I2 statistic, and generic inverse variance with a random-effects model. Risk Of Bias In Non-randomized Studies of Interventions and Newcastle-Ottawa scale were used to assess bias and study quality. RESULTS: The literature search produced 2613 results and 473 unique citations for facial reanimation. Twenty-nine studies including 2046 patients were included in the systematic review. A meta-analysis of eligible data (1952 observations from 23 studies) showed statistically significant differences between the groups (CFNG: 0.94; 95% confidence interval [CI], 0.76-1.00, CLFN: 0.91; 95% CI, 0.49-1.00, MNM: 0.26; 95% CI, 0.05-0.54, DI: 0.98; 95% CI, 0.90-1.00, P < 0.001). In pairwise comparisons, statistically significant differences were found between MNM and other neurotization strategies (P < 0.001 in CFNG compared with MNM, P = 0.013 for CLFN compared with MNM, P < 0.001 for DI compared with MNM). CONCLUSIONS: DI- and CLFN-driven strategies achieved the most promising outcomes, whereas MNM showed the potential to elicit spontaneous smile at a lower extent. Our meta-analysis was limited primarily by incongruency between spontaneity assessment systems. Consensus on a standardized tool would enable more effective comparisons of the outcomes.

Free Functional Muscle Transfer and One Bone Forearm for Upper-Extremity Limb Salvage After High-Energy Ballistic Trauma.

Upper-extremity limb salvage following high-energy trauma poses unique challenges of massive soft tissue injury in the setting of large bone defects, traumatic segmental neurovascular injuries, and functional deficits. These complex injuries require multidisciplinary care to achieve requisite revascularization, bone stabilization, and preservation of remaining options for soft tissue coverage. This case presents a 45-year-old man who sustained a high-velocity gunshot resulting in a dysvascular limb. Through shared decision-making, upper-extremity limb salvage was pursued. Successful initial limb salvage included a reversed great saphenous vein graft from the brachial artery to the radial artery, followed by one bone forearm with nonvascularized graft from the ipsilateral distal ulna, latissimus dorsi free functioning muscle transfer with an end-to-side anastomosis to the brachial artery proximal to the vein graft, and coaptation of the anterior interosseous donor nerve from the proximal median nerve stump to the thoracodorsal recipient nerve.

Free functional muscle transfer for lower extremity reconstruction.

BACKGROUND: Free functional muscle transfer is a reconstructive strategy for the reconstruction of lost muscle units in the lower extremity after oncologic resection, trauma, compartment syndrome, or severe nerve injuries. Under appropriate circumstances, free functional muscle transfer may be the only suitable reconstructive option. This article reviews the underlying principles of free functional muscle transfer, its application to lower extremity reconstruction, appropriate patient selection, and surgical techniques. METHODS: The underlying principles of free functional muscle transfer, its application to lower extremity reconstruction, appropriate patient selection, and surgical techniques are presented. Commonly used donor muscles appropriate for each type of functional defect are discussed. A review of recent publications on free functional muscle transfer in the lower extremity was also performed. RESULTS: Good functional recovery with a Medical Research Council grade of up to 4/5 and full range of motion can be attained with free functional muscle transfer. Clinical outcomes and specific parameters for published case series in lower extremity free functional muscle transfer are presented and an illustrative case. CONCLUSION: Free functional muscle transfer is a suitable treatment for the appropriate patient to restore essential functions and potentially regain ambulation. However, additional published clinical outcomes are needed and represent a major area for further investigation.

Age-related outcomes of facial reanimation surgery using gracilis free functional muscle transfer innervated by the masseteric nerve: A retrospective cohort study.

BACKGROUND: The free functional muscle gracilis transfer is an established approach in facial reanimation surgery; however, the significance of its neurotization and the patient's age is still inconclusive. Several donor nerves are available for facial reanimation using the free functional gracilis muscle transfer. OBJECTIVE: This retrospective cohort study investigates whether the masseteric nerve is an equally reliable donor nerve in both older and younger patients. METHODS: We included 46 patients (13-71 years, male and female) who underwent nerve-to-masseter (NTM)-driven free functional muscle transfer (FFMT) between January 2008 and December 2019. Patients were distributed into three cohorts according to their age at surgery. We assessed the facial symmetry before and after surgery using the pupillo-modiolar angle. Commissure height and excursion deviation were measured with the Emotrics software. Patient-reported outcome measurements were taken using the Facial Clinimetric Examination (FaCE) scale. RESULTS: All patients had successful flap innervation, except for one patient in the middle-aged cohort (31-51 years). The postoperative facial symmetry at rest, smiling, and laughing was analyzed with the pupillo-modiolar angle and the Emotrics software and showed similar results between all cohorts. The FaCE scale showed similar scores for the middle-aged (31-51 years) cohort and the senior cohort (52-71 years). The social function score in the senior cohort was higher than in the middle-aged cohort, without statistical significance. One patient in the middle-aged (31-51 years) cohort and the senior cohort (52-71 years), respectively, underwent emergency revision due to impaired flap perfusion and could be salvaged. CONCLUSIONS: NTM-driven FFMT for facial reanimation is a safe and reliable procedure across all age groups of patients.

An assessment of the variation of the intramuscular innervation of the gracilis muscle, with the aim of determining its neuromuscular compartments.

Some muscles present neuromuscular compartments, one of which is the gracilis muscle. The aim of the present study is to determine the number of compartments present within the gracilis muscle based on its intramuscular innervation patterns; such knowledge could be of value in free functional muscle transfer. The study comprised 72 gracilis muscles (38 women, 34 men), fixed in 10% formalin solution. The muscles were removed and then stained using Sihler's method. When sufficient transparency was achieved, some measurements were made. Three different types of intramuscular innervation were distinguished. Type I (70.8%) was featured by at least one direct proximal nerve branch. Type II (23.6%) presented at least one indirect proximal nerve branch. Type III (5.6%) did not possess any proximal nerve branch. The median of descended nerve branches was five. Considerable anatomical variation is possible within the intramuscular innervation of the gracilis muscle. The muscle presents neuromuscular compartments, but the exact number depends on the type of its intramuscular innervation and the number of the main descendent nerve branches. All three types seem to be appropriate for free functional muscle transfer. Our findings may be of great value for surgeons carrying out complex reconstructions with the use of the gracilis muscle.

A comprehensive anatomical classification system of the extramuscular innervation of the gracilis muscle as guidance for free functional muscle transfer.

PURPOSE: The gracilis muscle is one of the most frequently used muscles in reconstructive surgeries. It can be utilized as both less complex flaps and a free functional muscle flap to restore function to other muscles. As little is known of the precise extramuscular innervation of the gracilis muscle, the present study performs an accurate assessment to provide as much important anatomical information for clinicians as possible. MATERIAL AND METHODS: A classical anatomical dissection was performed on eighty-five lower limbs (45 right, 40 left) fixed in 10% formalin solution. The variability in the extramuscular innervation of the gracilis muscle was assessed. Some morphometric measurements were collected. RESULTS: A four-fold classification of extramuscular innervation was created for the gracilis muscle. Type I (64.7%), the most frequent type, presented at least one proximal nerve branch. Type II (25.9%) lacked this branch. Type III (8.2%) possessed an additional neural supply from the muscular nerve branch innervating the adductor longus muscle. Type IV (1.2%) was similar to Type III, but the additional neural supply originated from the muscular nerve branch innervating the adductor magnus muscle. CONCLUSION: Clear anatomical variability was noted for extramuscular innervation of the gracilis muscle. All the presented Types seem to be suitable for splitting a muscle belly and use its part in free functional muscle transfer. However, it appears that Type III and IV may ease this procedure, because of the additional nerve branches. This classification system can deliver important information for clinicians performing complex reconstructive surgeries with the use of the gracilis muscle.

[Transfer of the pronator quadratus to restore opposition of the thumb: An anatomic study and a clinical report]. / Étude anatomique sur le lambeau de carré pronateur pédiculé réinnervé pour réanimer l'opposition du pouce et application clinique.

OBJECTIVE: The purpose of this study is to explore the feasibility of reconstructing the APB with a pedicled PQ flap, and to report results in a child presenting with bilateral radial deficiency. METHODS: Twenty-one injected cadaver upper extremities were dissected. The muscle was pedicled distally on the transverse carpal artery, and reinnervated with the flexor digiti minimi (FDM) motor branch. The transfer was evaluated on 3 parameters: surgical feasibility, length of the distal pedicle and distance from the coaptation site to the muscle entry of recipient nerve. A bilateral PQ pedicled transfer was accomplished in a 17-month old child with bilateral radial deficiency. RESULTS: In the cadaver study, transfer of PQ to the APB was feasible and the distal end of the PQ transfer was reaching the radial side of the first metacarpophalangeal joint in all cases. The length of the distal pedicle on the transverse carpal artery was 38.5±0.20mm. The distance from coaptation of the FDM to the PQ muscle entry was 43.0±3.77mm. At 7 months, there was a cosmetic improvement of the thenar eminence, a bilateral M3 abduction of the thumb and a functional improvement from bilateral PQ pedicled transfer. CONCLUSIONS: Reconstruction of the APB may be achieved with a PQ pedicled transfer reinnervated, improving the function and the cosmetic aspect of the thenar eminence without sacrificing any function of the hand.

Single incision thenar muscle reconstruction using the free functional pronator quadratus flap.

BACKGROUND: Injuries to the thenar muscle mass or the thenar branch of the median nerve and resulting loss of thumb opposition lead to a massive impairment of hand function. For decades, reconstructive approaches were based on tendon transfers. To broaden the reconstructive repertoire, we present the free functional pronator quadratus flap as a viable alternative for functional reconstruction and provide a specification for its indication. We demonstrate our surgical technique to a single incision reconstruction using the free functional pronator quadratus flap. Based on a series of three patients, which were analyzed for hand function using Kapandji's score and the angle of Bourrel, grip strength and nerve conduction velocity in a two year follow up, we present an indication algorithm. RESULTS: After successful reinnervation of all flaps, we found an improvement of Kapandji's score from 4.3 ± 0.94 preoperatively, to 8.7 ± 0.47 after two years. Accordingly, the angle of Bourrel decreased from 75.75 ± 3.45 degrees to 36.96 ± 3.68 degree. Grip strength also improved from 14 ± 2.2 kg to 26.2 ± 1.2 kg. No impairment of wrist pronation was observed. CONCLUSION: We found excellent functional recovery of thumb opposition and strength, showing similar or even superior results compared to results from tendon transfers. With the benefit of a single incision surgery and therefore minimal donor site morbidity, this free functional muscle transfer is a viable alternative to classic tendon transfers.

Management of Adult Brachial Plexus Injuries.

Adult brachial plexus injuries result in profound functional deficits, debilitating pain, substantial mental health implications, and extensive economic impacts. Their initial evaluation includes a detailed physical examination, electrodiagnostic studies, advanced imaging, and patient counseling. A team-based approach, led by a peripheral nerve surgeon and including hand therapists, electrodiagnosticians, mental health experts, and pain-management specialists, is used to provide optimal longitudinal care during the lengthy recovery process. The options for the surgical management of brachial plexus injuries include exploration, neurolysis, nerve grafting, nerve transfer, free functional muscle transfer, tendon transfer, arthrodesis, and amputation. When treated within 6 months, the outcomes are favorable for the restoration of essential shoulder and elbow function. Free functional muscle transfer is a powerful tool to address elbow flexion and rudimentary grasp in both primary and delayed settings. The restoration of hand function remains a challenge for patients with complete brachial plexus injury. The purpose of this review is to summarize foundational concepts in diagnosis and management, discuss current trends and controversial topics, and address areas for future investigation.

Long-term outcomes of dual innervation in functional muscle transfers for facial palsy.

BACKGROUND: This study describes a different approach with a 2-stage facial reanimation in patients with long-standing unilateral facial paralysis using free gracilis muscle transfer, innervated by both cross-facial nerve graft and masseteric nerve. The authors present their rationale, surgical technique, and long-term outcomes. METHODS: Between August 2012 and March 2016, 11 patients (6 female and 5 male patients) underwent a 2-staged dually innervated gracilis muscle transfer. Patients were evaluated with physical examination and needle electromyography. A standardized assessment of preoperative and postoperative photographs and videos was performed using Terzis' smile functional grading system at 48 months following surgery and the Emotrics software to assess improvement in symmetry over a 36-month postoperative period. RESULTS: Voluntary contraction of the gracilis muscle was observed in all patients at a mean of 4 months and 4 days following muscle transfer. A spontaneous smile produced without teeth clenching was developed in all patients by 18 months postoperatively. Six patients achieved excellent and 5 good results. The difference between the averaged pre- and postoperative scores was statistically significant. With Emotrics, there were significant improvements in the smile angle, upper lip elevation, commissural excursion, and commissural height, with continuous improvement over 36 months. The postoperative electromyography (EMG) confirmed dual innervation of the gracilis muscle by the facial and masseteric donor motor neural sources. We present our results at minimum 48 months postoperatively. CONCLUSIONS: Dual innervated two-stage gracilis transfer is an effective method for reanimation in long-standing unilateral facial paralysis, providing both rapid reinnervation of the transferred muscle, together with a powerful, synchronous smile.

Workhorse Free Functional Muscle Transfer Techniques for Smile Reanimation in Children with Congenital Facial Palsy: Case Report and Systematic Review of the Literature.

BACKGROUND: Pediatric facial palsy represents a rare multifactorial entity. Facial reanimation restores smiling, thus boosting self-confidence and social integration of the affected children. The purpose of this paper is to present a systematic review of microsurgical workhorse free functional muscle transfer procedures with emphasis on the long-term functional, aesthetic, and psychosocial outcomes. MATERIALS AND METHODS: We performed a literature search of the PubMed database from 1995 to 2019 using the following search strategy: "facial paralysis"[Title/Abstract] OR "facial palsy"[Title]. We used as limits: full text, English language, age younger than 18 years, and humans. Two independent reviewers performed the online screening process using Covidence. Forty articles met the inclusion criteria. The protocol was aligned with the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and was registered at the International Prospective Register of Systematic Reviews (PROSPERO, CRD42019150112) of the National Institute for Health Research. RESULTS: Free functional muscle transfer procedures include mainly segmental gracilis, latissimus dorsi, and pectoralis minor muscle transfer. Facial reanimation procedures with the use of the cross-face nerve graft (CFNG) or masseteric nerve result in almost symmetric smiles. The transplanted muscle grows harmoniously along with the craniofacial skeleton. Muscle function and aesthetic outcomes improve over time. All children presented improved self-esteem, oral commissure opening, facial animation, and speech. CONCLUSIONS: A two-stage CFNG plus an FFMT may restore a spontaneous emotive smile in pediatric facial palsy patients. Superior results of children FFMT compared to adults FFMT are probably attributed to greater brain plasticity.

Restoration of Elbow Flexion With a Free Functional Gracilis Muscle Transfer in an Arthrogrypotic Patient Using a Motor Nerve to Pectoralis Major.

Background: Patients with arthrogryposis may exhibit inability to flex the elbow. A free functional gracilis muscle transfer (FFGMT) can be used to restore elbow flexion. In our search of the available literature, we have not seen any descriptions of using a motor branch to the pectoralis major as a donor nerve to establish elbow flexion. Methods: We performed an FFGMT for restoration of elbow flexion in an arthrogrypotic patient with no active elbow flexion, who had a Medical Research Council (MRC) muscle grade of 0. Results: We report our 4.5-year outcomes. After undergoing an FFGMT for elbow flexion, our patient was able to gain an MRC grade 4 and achieve an arc of motion of 25° to 140°. Conclusion: An FFGMT for elbow flexion may be performed successfully using a motor branch to the pectoralis major.

Changes in Electrical Activity of the Masseter Muscle and Masticatory Force after the Use of the Masseter Nerve as Donor in Facial Reanimation Surgery.

Introduction The masseter nerve has been used as a donor nerve for facial reanimation procedures due to the multiple advantages it offers; it has been generally considered that sacrifice of the masseter nerve does not alter the masticatory apparatus; however, there are no objective studies to support this claim. Objective To evaluate the impact that the use of the masseter nerve in dynamic facial reconstruction has on the electrical activity of the masseter muscle and on bite force. Materials and Methods An observational and prospective longitudinal study was performed measuring bite force and electrical activity of the masseter muscles before and 3 months after dynamic facial reconstructive surgery using the masseter nerve. An occlusal analyzer and surface electromyography were employed for measurements. Results The study included 15 patients with unilateral facial paralysis, with a mean age of 24.06 ± 23.43. Seven patients were subjected to a masseter-buccal branch nerve transfer, whereas in eight patients, the masseter nerve was used as a donor nerve for gracilis free functional muscle transfer. Electrical activity of the masseter muscle was significantly reduced after surgery in both occlusal positions: from 140.86 ± 65.94 to 109.68 ± 68.04 ( p = 0.01) in maximum intercuspation and from 123.68 ± 75.64 to 82.64 ± 66.56 ( p = 0.01) in the rest position. However, bite force did not show any reduction, changing from 22.07 ± 15.66 to 15.56 ± 7.91 ( p = 0.1) after the procedure. Conclusion Masseter nerve transfer causes a reduction in electromyographic signals of the masseter muscle; however, bite force is preserved and comparable to preoperative status.

Use of the Facial Artery for Free Functioning Muscle Transfers: An Alternative Pedicle for Salvage in Brachial Plexus Lesions with Vascular Injuries.

Free functional muscle transfer (FFMT) is a salvage procedure recommended in cases of brachial plexus injury with late presentations or failures of primary nerve reconstruction. The workhorse for most authors is the gracilis, and the most common indication is the restoration of elbow flexion. For successful revascularization of the muscle, donor vessels must be in proximity of the site of the muscle fixation and allow direct coaptation to a donor nerve, ideally without the use of nerve grafts. A major problem occurs when patients have sustained concomitant vascular injuries to the subclavian and/or axillary arteries and had previous surgical dissections in the area where the most common vascular pedicles are located. The authors report the use of the rerouted facial vessels as donors in these complex cases. The surgical technique is presented, along with three cases where the procedure was used. The flaps survived in all the patients and grade > 3/5 muscle contraction was observed in the two patients who had adequate follow-up. Conclusion: the use of the facial vessels as donor vessels is an option to revascularize a FFMT in the setting of severe vascular injury to the subclavian and axillary arteries.

Microsurgical Reconstruction of the Lower Extremity.

Reconstruction of bony and soft tissue defects of the lower extremity has been revolutionized by the advent of microsurgical tissue transfer. There are numerous options for reconstruction. Possibilities include transfer of soft tissue, composite (bone and soft tissue) tissue, and functional muscle. Many lower extremity reconstructions require staged procedures. Planning is of paramount importance especially in regard to vascular access when multiple free flaps are required. Soft tissue reconstruction of the lower extremity may be accomplished with muscle flaps such as the rectus femoris and latissimus dorsi covered with a skin graft. Fasciocutaneous flaps such as the anterolateral thigh flap may be more appropriate in a staged reconstruction which requires later elevation of the flap. Loss of a significant portion of bone, such as the tibia, can be difficult to manage. Any gap greater than 6 cm is considered a reasonable indication for vascularized bone transfer. The contralateral free fibula is the donor site of choice. Functional reconstruction of the anterior compartment of the leg may be performed with a gracilis muscle transfer, effectively eliminating foot drop and providing soft tissue coverage. Muscle tensioning is critical for effective excursion and dorsiflexion of the foot. Long-term results of microsurgical reconstruction of the lower extremity show good results and reasonable rates of limb salvage.

Pre-operative masseter muscle EMG activation during smile predicts synchronicity of smile development in facial palsy patients undergoing reanimation with the masseter nerve: A prospective cohort study✰.

BACKGROUND: Synchronicity of the oral commissure movement of a bilateral smile is a significant goal for reconstruction in facial reanimation and may only be guaranteed with use of the facial nerve as a donor nerve. Yet over the years several studies report some degree of spontaneity in certain patients when using a non-facial donor nerve, which indicates that synchronous initiation of the smile might be achievable with other donor nerves. We designed a prospective cohort study to evaluate whether pre-operative involuntary activation of the masseteric nerve during smile predicts development of a synchronous smile development when using the masseteric nerve for reanimation. METHODS: In a prospective cohort study unilateral long-standing facial palsy patients scheduled for dynamic smile reanimation with a free functional muscle transplant using the masseteric nerve as a donor nerve were preoperatively evaluated via EMG for involuntary activation of the masseter muscle upon smiling, which we called coactivation. Postoperatively, six months after noting the first muscle contraction smile synchronicity was evaluated. We analyzed the synchronicity of the bilateral smile development by analyzing slow-motion video sequences of the patients that were taken while the patients were watching funny video sequences. Results were then correlated with the pre-operative EMG. RESULTS: 30 patients were recruited for this prospective study and underwent facial reanimation surgery with a free gracilis transfer innervated by the masseteric nerve. 19 patients demonstrated involuntary coactivation of the masseter muscle upon smiling and 11 did not. Postoperatively all patients could demonstrate a voluntary smile. 94% of patients who had preoperative coactivation showed a synchronous movement of the oral commissure when smiling. In those patients, that did not show activation of the masseter muscle upon smiling 0% showed synchronicity. The preoperative coactivation of the masseter muscle is able to predict the outcome regarding synchronicity of the smile with a sensitivity of 99.7%, a specificity of 88.5% and 92.5% positive predictive value and 99.6% negative predictive value (p < 0.001 for all). CONCLUSIONS: The lack of masseter co-activation with smile predicts a lack of spontaneous involuntary smile after dynamic smile reconstruction using the masseteric nerve.

The split hypoglossal nerve versus the cross-face nerve graft to supply the free functional muscle transfer for facial reanimation: A comparative study.

Long-standing cases of facial paralysis are currently treated with free functional muscle transfer. Several nerves are mentioned in the literature to supply the free muscle transfer. The aim of this study is to compare the split hypoglossal nerve and the cross-face nerve graft to supply the free functional muscle transfer in facial reanimation. Of 94 patients with long-standing, unilateral facial palsy, 49 were treated using the latissimus dorsi muscle supplied by the split hypoglossal nerve, and 45 patients were treated using the latissmus dorsi muscle supplied by healthy contralateral buccal branch of the facial nerve. The excursion gained by the free muscle transfer supplied by the split hypoglossal nerve (mean 19.20 ± 6.321) was significantly higher (P value 0.001) than that obtained by the contralateral buccal branch of the facial nerve (mean 14.59 ± 6.245). The split hypoglossal nerve appears to be a good possible option to supply the free vascularised muscle transfer in facial reanimation. It yields a stronger excursion in less time than the contralateral cross-face nerve graft.