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.

A Simple Brochure Improves Disposal of Unused Opioids: An Observational Cross-Sectional Study.

BACKGROUND: We evaluated the effectiveness of a simple, low-cost educational brochure in improving disposal rates of unused opioids after outpatient upper extremity surgery. METHODS: This cross-sectional study enrolled eligible adult patients from a peripheral nerve clinic between November 2017 and September 2018. Patients either received or did not receive the educational brochure, which outlined a simple method to dispose of unused opioids and completed a survey at 2 weeks after surgery. We compared the proportion of patients who disposed of unused opioids after surgery between the group that had received the brochure and the group that had not. Categorical data were analyzed with χ2 test, proportions data with binomial tests, and numerical data with Mann-Whitney U test, all with a significance level of P < .05. RESULTS: There were 339 survey respondents. Nineteen patients who did not meet inclusion criteria were excluded. Of the 320 remaining patients, 139 received the brochure and 181 did not. An additional 55 patients were excluded due to preoperative opioid use. Overall, 35.3% of recipients and 38.3% of those who did not receive the brochure used all of their prescribed opioid medication (P = .625; confidence interval = -14.6%-8.8%). Among patients with unused opioid medication, a significantly higher proportion of brochure recipients disposed of the medicine compared with those who did not receive the brochure (46.7% vs 19.6%, P < .001). CONCLUSIONS: Distribution of an educational brochure significantly improved disposal of unused opioids after surgery. This easily implemented intervention can improve disposal of unused opioids and ultimately decrease excess opioids available for diverted use in the community.

Nerve transfers for femoral nerve palsy: an updated approach and surgical technique.

OBJECTIVE: Femoral nerve palsy results in significant impairment of lower extremity function due to the loss of quadriceps muscle function. The authors have previously described their techniques utilizing the anterior obturator and sartorius nerves for transfer in cases of femoral nerve palsy presenting within 1 year of injury. In the current study, the authors discuss their updated techniques, results, and approach to partial and complete femoral nerve palsies using femoral nerve decompression and nerve transfers. METHODS: They conducted a retrospective review of patients with femoral nerve palsies treated with their technique at the Washington University School of Medicine in 2008-2019. Primary outcomes were active knee extension Medical Research Council (MRC) grades and visual analog scale (VAS) pain scores. RESULTS: Fourteen patients with femoral nerve palsy were treated with femoral nerve decompression and nerve transfer: 4 with end-to-end (ETE) nerve transfers, 6 with supercharged end-to-side (SETS) transfers, and 4 with ETE and SETS transfers, using the anterior branch of the obturator nerve, the sartorius branches, or a combination of both. The median preoperative knee extension MRC grade was 2 (range 0-3). The average preoperative VAS pain score was 5.2 (range 1-9). Postoperatively, all patients attained an MRC grade 4 or greater and subjectively noted improved strength and muscle bulk and more natural gait. The average postoperative pain score was 2.3 (range 0-6), a statistically significant improvement (p = 0.001). CONCLUSIONS: Until recently, few treatments were available for high femoral nerve palsy. A treatment strategy involving femoral nerve decompression and nerve transfers allows for meaningful functional recovery and pain relief in cases of partial and total femoral nerve palsy. An algorithm for the management of partial and complete femoral nerve palsies and a detailed description of surgical techniques are presented.

Adductor magnus muscle transfer to restore knee extension: Anatomical studies and clinical applications.

BACKGROUND: Loss of knee extension causes significant impairment. Though nerve-based reconstruction is preferable in cases of femoral nerve palsy or injury, these surgeries are not always appropriate if the pathology involves the quadriceps muscles or presentation too late for muscle reinnervation. Muscle transfers are another option that has been underutilized in the lower extremity. We describe the successful restoration of knee extension by adductor magnus muscle transfer without functional donor morbidity, along with anatomical considerations. METHODS: Ten fresh frozen cadaveric lower limbs were dissected at the groin and thigh. In addition, three patients presented with femoral nerve palsy for which nerve-based reconstruction was not appropriate because of late presentation. In these patients, adductor magnus muscle transfers were performed, along with sartorius, gracilis, and tensor fasciae latae transfers if available and healthy. RESULTS: In cadavers, the pedicle for the adductor magnus is at the level of the gracilis and adequate for muscle transfer, with sufficient weavable tendon length. The only major structure at risk is the femoral neurovascular bundle, which is in a reliable anatomic position. Two patients recovered 4/5 active knee extension and ambulation without assistive devices. A third required reoperation for a loosened tendon weave, after which the noted improved stability and strength with ambulation but did not regain strong active knee extension and continued to require a cane. CONCLUSIONS: We present a novel reconstructive approach for loss of quadriceps function in patients, which yields good clinical outcomes, with anatomic and technical details to demonstrate the utility of this technique. Ongoing evaluation of optimal technique and rehabilitation to maximize functional outcomes is still needed.

Femoral nerve decompression and sartorius-to-quadriceps nerve transfers for partial femoral nerve injury: a cadaveric study and early case series.

OBJECTIVE: Partial femoral nerve injuries cause significant disability with ambulation. Due to their more proximal and superficial location, sartorius branches are often spared in femoral nerve injuries. In this article, the authors report the benefits of femoral nerve decompression, demonstrate the feasibility of sartorius-to-quadriceps nerve transfers in a cadaveric study, describe the surgical technique, and report clinical results. METHODS: Four fresh-frozen cadaveric lower limbs were dissected for anatomical analysis of the sartorius nerve. In addition, a retrospective review of patients with partial femoral nerve injuries treated with femoral nerve decompression and sartorius-to-quadriceps nerve transfers was conducted. Pre- and postoperative knee extension Medical Research Council (MRC) grades and pain scores (visual analog scale) were collected. RESULTS: Up to 6 superficial femoral branches innervate the sartorius muscle just distal to the inguinal ligament. Each branch yielded an average of 672 nerve fibers (range 99-1850). Six patients underwent femoral nerve decompression and sartorius-to-quadriceps nerve transfers. Four patients also had concomitant obturator-to-quadriceps nerve transfers. At final follow-up (average 13.4 months), all patients achieved MRC grade 4-/5 or greater knee extension. The average preoperative pain score was 5.2, which decreased to 2.2 postoperatively (p = 0.03). CONCLUSIONS: Femoral nerve decompression and nerve transfer using sartorius branches are a viable tool for restoring function in partial femoral nerve injuries. Sartorius branches serve as ideal donors in quadriceps nerve transfers because they are expendable, are close to their recipients, and have an adequate supply of nerve fibers.

Stem cell-based approaches to enhance nerve regeneration and improve functional outcomes in vascularized composite allotransplantation.

PURPOSE OF REVIEW: The current review will discuss the current understanding of nerve regeneration in vascularized composite allotransplantation (VCA). The success of proximal arm and leg transplants has been hampered by the limitations of nerve regrowth across long distances resulting in poor regeneration and functional recovery. Relevant research in stem-cell therapies to overcome these issues will be reviewed. RECENT FINDINGS: The effect of rejection on nerve regeneration in the VCA may be unpredictable and may be quite different for the nerve allograft. The issues that limit functional outcome are likely common to both VCA and proximal nerve injuries or replantation. Stem-cell therapies have focused on augmenting Schwann cell function and appear promising. SUMMARY: A better understanding of the effects of transplant rejection on nerve regeneration and function, as well as the factors that affect regeneration over long distances may inform further therapeutic approaches for improvement.

Femoral nerve transfers for restoring tibial nerve function: an anatomical study and clinical correlation: a report of 2 cases.

Sciatic nerve injuries cause debilitating functional impairment, particularly when the injury mechanism and level preclude reconstruction with primary grafting. The purpose of this study was to demonstrate the anatomical feasibility of nerve transfers from the distal femoral nerve terminal branches to the tibial nerve and to detail the successful restoration of tibial function using the described nerve transfers. Six cadaveric legs were dissected for anatomical analysis and the development of tension-free nerve transfers from femoral nerve branches to the tibial nerve. In 2 patients with complete tibial and common peroneal nerve palsies following sciatic nerve injury, terminal branches of the femoral nerve supplying the vastus medialis and vastus lateralis muscles were transferred to the medial and lateral gastrocnemius branches of the tibial nerve. Distal sensory transfer of the saphenous nerve to the sural nerve was also performed. Patients were followed up for lower-extremity motor and sensory recovery up to 18 months postoperatively. Consistent branching patterns and anatomical landmarks were present in all dissection specimens, allowing for reliable identification, neurolysis, and coaptation of donor femoral and saphenous nerve branches to the recipients. Clinically, the patients obtained Medical Research Council Grade 3 and 3+ plantar flexion by 18 months postoperatively. Improved strength was accompanied by improved ambulation in both patients and by a return to competitive sports in 1 patient. Sensory recovery was demonstrated by an advancing Tinel sign in both patients. This study illustrates the clinical success and anatomical feasibility of femoral nerve to tibial nerve transfers after proximal sciatic nerve injury.

Rectus Abdominis Motor Nerves as Donor Option for Free Functional Muscle Transfer: A Cadaver Study and Case Series.

BACKGROUND: Current management of brachial plexus injuries includes nerve grafts and nerve transfers. However, in cases of late presentation or pan plexus injuries, free functional muscle transfers are an option to restore function. The purpose of our study was to describe and evaluate the rectus abdominis motor nerves histomorphologically and functionally as a donor nerve option for free functional muscle transfer for the reconstruction of brachial plexus injuries. METHODS: High intercostal, rectus abdominis, thoracodorsal, and medial pectoral nerves were harvested for histomorphometric analysis from 4 cadavers from levels T3-8. A retrospective chart review was performed of all free functional muscle transfers from 2001 to 2014 by a single surgeon. RESULTS: Rectus abdominis nerve branches provide a significant quantity of motor axons compared with high intercostal nerves and are comparable to the anterior branch of the thoracodorsal nerve and medial pectoral nerve branches. Clinically, the average recovery of elbow flexion was comparable to conventional donors for 2-stage muscle transfer. CONCLUSION: Rectus abdominis motor nerves have similar nerve counts to thoracodorsal, medial pectoral nerves, and significantly more than high intercostal nerves alone. The use of rectus abdominis motor nerve branches allows restoration of elbow flexion comparable to other standard donors. In cases where multiple high intercostal nerves are not available as donors (rib fractures, phrenic nerve injury), rectus abdominis nerves provide a potential option for motor reconstruction without adversely affecting respiration.

Lower Extremity Reconstruction with Free Gracilis Flaps.

Background There have been significant advancements in lower extremity reconstruction over the last several decades, and the plastic surgeon's armamentarium has grown to include free muscle and fasciocutaneous flaps along with local perforator and propeller flaps. While we have found a use for a variety of techniques for lower extremity reconstruction, the free gracilis has been our workhorse flap due to the ease of harvest, reliability, and low donor site morbidity. Methods This is a retrospective review of a single surgeon's series of free gracilis flaps utilized for lower extremity reconstruction. Demographic information, comorbidities, outcomes, and secondary procedures were analyzed. Results We identified 24 free gracilis flaps. The duration from injury to free flap coverage was ≤ 7 days in 6 patients, 8-30 days in 11 patients, 31-90 days in 4 patients, and > 90 days in 3 patients. There were 22 (92%) successful flaps and an overall limb salvage rate of 92%. There was one partial flap loss. Two flaps underwent incision and drainage in the operating room for infection. Two patients developed donor site hematomas. Four patients underwent secondary procedures for contouring. Our subset of pediatric patients had 100% flap survival and no secondary procedures at a mean 30-month follow-up. Conclusion This study demonstrates the utility of the free gracilis flap in reconstruction of small- to medium-sized defects of the lower extremity. This flap has a high success rate and a low donor site morbidity. Atrophy of the denervated muscle over time allows for good shoe fit, often obviating the need for secondary contouring procedures.

Donor nerve sources in free functional gracilis muscle transfer for elbow flexion in adult brachial plexus injury.

BACKGROUND: With complete plexus injuries or late presentation, free functional muscle transfer (FFMT) becomes the primary option of functional restoration. Our purpose is to review cases over a 10-year period of free functioning gracilis muscle transfer after brachial plexus injury to evaluate the effect of different donor nerves used to reinnervate the FFMT on functional outcome. METHODS: A retrospective study from April 2001 to January 2011 of a single surgeon's practice was undertaken. During this time period 22 patients underwent FFMT at Washington University in St Louis, Missouri for elbow flexion. RESULTS: Thirteen patients for whom FFMT was performed for elbow flexion met all of the requirements for inclusion in this study. Average time from injury to first operation was 12.8 months (range 4-60), and average time from injury to FFMT was 29 months (range 8-68). Average follow-up was 31.8 months (range 11-84). The nerve donors utilized included the distal accessory nerve, intercostal with or without rectus abdominis nerves, medial pectoral nerves, thoracodorsal nerve, and flexor carpi ulnaris fascicle of ulnar nerve. Functional recovery of elbow flexion was measured using the MRC grading system which showed 1 M5/5, 5 M4, 4 M3, and 3 M2 outcomes. CONCLUSION: Intraplexal donor motor nerves if available will provide better transferred muscle function because they are higher quality donors closer to the muscle and can be done in one stage without a nerve graft. Otherwise, intercostal, rectus abdominis, or the distal accessory nerve should be used in a staged fashion. © 2016 Wiley Periodicals, Inc. Microsurgery 37:377-382, 2017.

Internal mammary artery perforator propeller flap for contralateral mastectomy defect: A case report.

The internal mammary artery perforator (IMAP) flap can be used as either loco-regional or free flap, and provides thin flexible coverage for defects of the chest wall and cervical regions. In this report, we present a bilateral mastectomy case in which the left mastectomy defect was closed with an IMAP propeller flap harvested from the right breast. Our patient with a history of left breast conservation therapy was diagnosed invasive ductal carcinoma in her left breast 14 years later. On physical examination, the patient's left breast displayed the stigmata of radiotherapy including dark discoloration and firmness to palpation, compared to contralateral pendulous breast. After bilateral mastectomy, an IMAP flap with a size of 26 cm × 11 cm was harvested from right chest and was transposed 180 degrees clockwise in a propeller fashion to the left mastectomy defect without any tension. The flap survived without any complication and the patient was free of recurrence or metastases during the follow-up of 18 months. The patient was satisfied with the outcome. IMAP propeller flap could be harvested safely to the anterior axillary fold in the subcutaneous fat plane. It may provide a large skin paddle especially in large breasted women. © 2016 Wiley Periodicals, Inc. Microsurgery 36:507-510, 2016.

Free Functional Muscle Transfers to Restore Upper Extremity Function.

Free functional muscle transfer provides an option for functional restoration when nerve reconstruction and tendon transfers are not feasible. To ensure a successful outcome, many factors need to be optimized, including proper patient selection, timing of intervention, donor muscle and motor nerve selection, optimal microneurovascular technique and tension setting, proper postoperative management, and appropriate rehabilitation. Functional outcomes of various applications to the upper extremity and the authors' algorithm for the use of free functional muscle transfer are also included in this article.

Robust Axonal Regeneration in a Mouse Vascularized Composite Allotransplant Model Undergoing Delayed Tissue Rejection.

Background: Nerve regeneration in vascularized composite allotransplantation (VCA) is not well understood. Allogeneic transplant models experience complete loss of nerve tissue and axonal regeneration without immunosuppressive therapy. The purpose of this study was to determine the impact of incomplete immunosuppression on nerve regeneration. Methods: In this study, transgenic mice (4 groups in total) with endogenous fluorescent protein expression in axons (Thy1-YFP) and Schwann cells (S100-GFP) were used to evaluate axonal regeneration and Schwann cell (SC) migration in orthotopic-limb VCA models with incomplete immunosuppression using Tacrolimus (FK506). Survival and complication rates were assessed to determine the extent of tissue rejection. Nerve regeneration was assessed using serial imaging of axonal progression and SC migration and viability. Histomorphometry quantified the extent of axonal regeneration. Results: Incomplete immunosuppression with FK506 resulted in delayed rejection of skin, muscle, tendon, and bone in the transplanted limb. In contrast, the nerve demonstrated robust axonal regeneration and SC viability based on strong fluorescent protein expression by SCs and axons in transgenic donors and recipients. Total myelinated axon numbers measured at 8 weeks were comparable in all VCA groups and not statistically different from the syngeneic donor control group. Conclusions: Our data suggest that nerve and SCs are much weaker antigens compared with skin, muscle, tendon, and bone in VCA. To our knowledge, this study is the first to prove the weak antigenicity of nerve tissue in the orthotopic VCA mouse model.

Predictive Value of Nutritional Markers for Wound Healing Complications in Bariatric Patients Undergoing Panniculectomy.

BACKGROUND: Hypoproteinemia and nutritional deficiencies are common after bariatric surgery, and although massive weight loss (MWL) patients experience increased wound complication rates, the association has not been causatively determined. OBJECTIVES: This study investigated preoperative nutritional parameters and wound complications in MWL patients (postbariatric and diet-controlled) undergoing panniculectomy at 2 academic institutions. METHODS: One hundred sixty-one consecutive patients undergoing elective panniculectomy after bariatric surgery or diet-controlled weight loss were identified. Patient demographics and nutritional indices (serum protein, albumin, and micronutrient levels) were analyzed. Complications including wound separation, infection, and operative debridements were compared. Post hoc comparisons tested for correlation between complications and nutritional markers. RESULTS: Postbariatric patients lost an average of 151 lb and presented at an average of 32 months after gastric bypass. Diet-controlled weight loss patients lost an average of 124 lb. Despite MWL, albumin levels were higher in the bariatric group (3.8 vs 3.4 g/dL, P < 0.05). Conversely, bariatric patients experienced increased wound complications (27% vs 14%; P < 0.05). Factors which were found to correlate to increased risk of wound dehiscence and infection were elevated body mass index at time of panniculectomy and amount of tissue removed. Multivariate analysis did not show serum albumin or percent weight loss to independently predict complications. CONCLUSIONS: Bariatric patients presenting for elective operations are at risk for protein and micronutrient deficiency. Despite aggressive replacement and normalization of nutritional markers, bariatric patients experience increased wound complications when compared to nonbariatric patients and traditional measures of nutritional evaluation for surgery may be insufficient in bariatric patients.

Motor and sensory nerve transfers in the forearm and hand.

BACKGROUND: Peripheral nerve injury is a significant problem affecting more than 1 million people around the world each year and poses major challenges to the plastic and reconstructive surgeon. For high upper extremity nerve injuries, distal muscle reinnervation and functional outcomes are generally poor. Tendon transfer has been the traditional reconstructive option in these cases to restore hand function. More recently, nerve transfers have been described in the forearm and hand to recover hand and wrist function and critical sensation. METHODS: This article reviews the surgical principles, donor nerve options, indications, and outcomes of distal nerve transfers for high upper extremity nerve injuries. RESULTS: The functional results of nerve transfers to date have been comparable to tendon transfers. The primary advantage is the potential for individual finger motion from a donor nerve with singular function. The disadvantage is the longer recovery time required for muscle reinnervation. CONCLUSIONS: Nerve transfers are a viable option for peripheral nerve injuries distal to the brachial plexus. The choice of management will depend on the patient's individual goals and priorities in terms of the need or desire for individual finger movement and the length of the recovery period.

Nerve transfers.

This article provides an update of the current state of motor and sensory nerve transfers for the functional reconstruction of proximal and distal nerve lesions of the upper extremity. General principles, indications, surgical options, and functional outcomes are summarized for conventional transfers used in brachial plexus reconstruction, more recently described distal nerve transfers for isolated nerve injuries in the extremity, and sensory nerve transfers performed both proximally and distally.

Direct radial to ulnar nerve transfer to restore intrinsic muscle function in combined proximal median and ulnar nerve injury: case report and surgical technique.

A distal median to ulnar nerve transfer for timely restoration of critical intrinsic muscle function is possible in isolated ulnar nerve injuries but not for combined ulnar and median nerve injuries. We used a distal nerve transfer to restore ulnar intrinsic function in the case of a proximal combined median and ulnar nerve injury. Transfer of the nonessential radial nerve branches to the abductor pollicis longus, extensor pollicis brevis, and extensor indicis proprius to the motor branch of the ulnar nerve was performed in a direct end-to-end fashion via an interosseous tunnel. This method safely and effectively restored intrinsic function before terminal muscle degeneration.

Nerve gaps.

SUMMARY: Peripheral nerve injury is a significant problem affecting greater that 1 million people around the world each year and poses major challenges to the plastic and reconstructive surgeon. When primary nerve repair is not possible, several options for management of the nerve gap include a nerve autograft, nerve conduit, and acellular nerve allograft. For extensive and proximal nerve injuries, cellular nerve allografts and nerve transfers may be considered. This article reviews the indications and outcomes for each option, as in many cases more than one option may be acceptable.