Nerve Transfers for Restoring Elbow Flexion in Brachial Plexus Palsy

Nerve transfers (NT) consist in sectioning a donor nerve and connecting it to the distal stump of a recipient unrepairable nerve. For elbow flexion restoration in brachial plexus palsy (BPP) we used different NT: 1) GF motor Ulnar Nerve to Biceps nerve (Oberlin technique), 2) Double fascicular median/ulnar to biceps/brachialis nerve transfer (Mackinnon), 3) InterCostal Nerves (ICN) to MCN (+/− nerve graft), 4) Medial Pectoral Nerve (MPN) to MCN, 5) ThoracoDorsal Nerve (TDN) to MCN, 6) Spinal Accessory Nerve (SAN) to MCN transfer, 7) Phrenic Nerve (PhN) to MCN, 8) Cervical Plexus C3-C4 to MCN and 9) Contralateral C7 (CC7). I want to present my personal experience using the phrenic nerve (PhN), the intercostal nerves (ICN) and Oberlin’s technique. The aim of this retrospective study is to evaluate the results of this procedure in BPP. NT is an important goal in BPP. ICN transfer into the nerve of biceps for elbow flexion recovery is a reliable procedure in BPP. ICN transfer for triceps offers a positive alternative (Carroll transposition). Oberlin technique is simple and offers better results in a shorter amount of time and is an effective and safe option.

Frozen Elephant Trunk with Gore Thoracic Endovascular Graft and Quadrifurcate Graft

The frozen elephant trunk has simplified the surgical treatment of the entire thoracic aorta; moreover many different technical variants of how to do it have been described. Our procedure include implantation of a Gore CTAG graft into the aortic arch followed by a teflon reinforced suture line that should include the stent graft and the native aorta. The 4-branched graft is then sutured to the distal stump therefore creating a custom-made frozen elephant trunk hybrid prosthesis. Three patients with acute type A aortic dissection and primary entry tear in the arch were operated with this technique. There were no early or late deaths, moreover no neurologic events occurred. The purpose of this article is to introduce an innovative technique for total arch replacement with the combination of a Gore CTAG stent graft used as a frozen elephant trunk and a standard 4-branched graft for arch reconstruction.

Staged salvage of diabetic foot with Chopart amputation and intramedullary nailing

We present a stepwise surgical approach that can be used, in lieu of a transtibial amputation, to preserve the lower limb in the setting of severe diabetic foot infections. A 63-year-old male status post left midfoot (Lisfranc’s) amputation presented to our hospital with a 4-year history of a left foot diabetic ulcer with associated purulent drainage and intermittent chills. On initial exam, the patient’s left foot amputation stump was plantarflexed, grossly erythematous, and edematous. The associated diabetic foot ulcer was actively draining purulent fluid. Following workup with radiography and ultrasound, the patient was diagnosed with a post-operative infection of the midfoot at the level of the amputation stump secondary to diabetic neuropathy. Our approach to management was a staged and included (1) surgical irrigation and debridement of the distal stump wound, (2) provisional negative pressure therapy, (3) a second-look procedure, and (4) a tibiotalocalcaneal fusion was performed using a lateral transfibular and plantar approach, after wound closure and resolution of active infection was achieved. At 36-month follow-up, the patient was fully weight-bearing in stiff sole sneakers with no gross overt alteration of gait pattern. The patient scored 79 points when assessed by the hindfoot American Orthopaedic Foot and Ankle Society Ankle-Hindfoot outcome score. In the patient with diabetes and cardiological restrictions, a Chopart amputation is preferred due to the decreased level of energy expenditure required for ambulation as compared to over more proximal levels of amputation.

Repair of chronic Achilles tendon rupture using Bosworth’s technique

Background: A large number of ruptures of the Achilles tendon occurs in the watershed hypovascular region (zone II) of the tendon which is approximately 2–6 cm proximal to the insertion of tendon at calcaneum. Chronic Achilles tendon rupture in the watershed area makes end to end repair of tendon less feasible and the neglected distal stump is often inapt for repair. A number of surgical techniques have been described for repair of chronic Achilles tendon in zone II. Our study was conducted with the objective of determining the efficacy and functional outcome of Bosworth’s technique that involves gastrocnemius-soleus turndown of proximal Achilles tendon. Materials and Methods: The study was conducted in a total of five patients with chronic tear of Achilles tendon and the Bosworth technique was used for repair in all the patients. All the patients were followed up for a period of 1 year and the functional outcome was assessed by scoring system devised by Leppilahti et al. Results: four out of the five patients showed excellent functional at the end of 1 year follow up. A good functional outcome was seen in one of the patients. All the patients were able to resume work 6 months postoperatively. Conclusion: The Bosworth’s technique is an excellent surgical procedure for repair of chronic Achilles tendon rupture in the watershed zone of the tendon.

Effects of PACAP on Schwann Cells: Focus on Nerve Injury

Schwann cells, the most abundant glial cells of the peripheral nervous system, represent the key players able to supply extracellular microenvironment for axonal regrowth and restoration of myelin sheaths on regenerating axons. Following nerve injury, Schwann cells respond adaptively to damage by acquiring a new phenotype. In particular, some of them localize in the distal stump to form the Bungner band, a regeneration track in the distal site of the injured nerve, whereas others produce cytokines involved in recruitment of macrophages infiltrating into the nerve damaged area for axonal and myelin debris clearance. Several neurotrophic factors, including pituitary adenylyl cyclase-activating peptide (PACAP), promote survival and axonal elongation of injured neurons. The present review summarizes the evidence existing in the literature demonstrating the autocrine and/or paracrine action exerted by PACAP to promote remyelination and ameliorate the peripheral nerve inflammatory response following nerve injury.

Functional Outcomes and MRI Results Following Knotless Repair of Acute Achilles Tendon Ruptures

Category: Ankle; Sports Introduction/Purpose: The surgical techniques for primary repair of acute Achilles tendon ruptures have evolved from large open incisions to mini-open and percutaneous techniques. Studies have demonstrated that lesser invasive surgical techniques may reduce the risk of post-operative wound complications. Knotless surgical repair of acute Achilles tendon ruptures can be performed through a mini-incision, but still permits a robust re-approximation of the tendon stumps and decreases suture burden through distal anchor fixation in the calcaneus. However, stress shielding and subsequent tendinosis of the distal tendon stump is a theoretical concern with this surgical technique. We hypothesize that our surgical technique allows for a durable repair through a minimally invasive approach, permitting a safe and accelerated rehabilitation protocol, excellent functional outcomes, and absence of distal stump tendinosis. Methods: A multicenter retrospective chart review was performed to identify all patients that underwent primary Achilles tendon repair using a knotless surgical technique with a minimum of one-year follow-up from three orthopedic foot and ankle surgeons’ practices. Exclusion criteria included: age <18, chronic Achilles tendon ruptures (>4 weeks), insertional Achilles tendon ruptures, revision Achilles surgery, peripheral neuropathy, and systemic inflammatory disease. All patients were contacted by phone and asked to return to the office for an MRI, clinical examination, and completion of functional outcome questionnaires. The primary outcome measure was the validated Achilles Tendon Total Rupture Score (ATRS). Secondary outcomes included the Visual Analog Score (VAS), postoperative complications, ankle range of motion, calf circumference, and single-heel rise. MRI was used to assess tendon continuity and healing, tendinosis, muscle atrophy, and bone marrow edema/stress fracture associated with anchor fixation in the calcaneus. MRI interpretation was performed by a single, blinded musculoskeletal radiologist. Results: Forty-three patients were identified with acute Achilles tendon ruptures. There were 36 patients (36/43, 84%) who underwent knotless Achilles tendon repair and agreed to participate in the study. The average time to clinical follow-up was 23.5 months (SD±16.3). The mean postoperative ATRS was 84.6 (SD±19.7). There was no significant difference in calf circumference (p=0.22), dorsiflexion (p=0.07), and plantarflexion (p=0.11) between the unaffected and surgical extremity at latest follow-up. One patient (1/36, 2.8%) experienced a re-rupture. There were no wound complications or neuritis. MRI was obtained in 26 patients (26/36, 72.2%) at an average of 17.5 months (SD±10.1). There were no MRI findings of distal stump tendinosis or calcaneal stress fractures. Thirty-two patients (32/36, 88.8%) returned to the same athletic activities one-year after surgery. Conclusion: There is paucity in the literature on functional outcomes following knotless Achilles tendon repair. In this multicenter study, we found that validated functional outcome scores and return to activity were similar to historical controls, with a low rate of surgical complications. MRI obtained in twenty-six patients (72.2%) at 17.5 months demonstrated an intact tendon without distal tendon stump stress shielding or calcaneal stress fracture. The knotless Achilles tendon repair is a unique surgical technique, minimizing suture burden and postoperative complications, while offering excellent functional outcomes and return to activity at two-year follow-up. The excellent clinical outcomes are corroborated by MRI.

Ultrasound-Guided Needle Localization Wires in Peripheral Nerve Injuries With Long Segmental Defects: Technical Case Report

BACKGROUND AND IMPORTANCE In cases of severe nerve trauma with significant local soft tissue damage, identification and subsequent repair of nerve stumps can pose a technical challenge. Ultrasound (US) localization in peripheral nerve surgery has recently become popular. We present a case report illustrating the use of needle-wire localization systems to identify proximal and several distal branches of an injured femoral nerve with a large segmental defect in order to illustrate how such techniques can be used to make surgical repair more efficient, particularly with identifying the distal stump(s). CLINICAL PRESENTATION We illustrate a case of a 16-yr-old female involved in a traumatic accident that lead to a severe injury of the femoral nerve and artery. The patient presented with a 7.3-cm defect between the proximal and distal aspect of the femoral nerve and its branches, respectively. High-resolution US was used to identify the proximal, large femoral nerve, and 3 distal stumps. By enlisting our musculoskeletal radiology team, we were able to trace distal branches of the femoral nerve and see their target muscles. Three separate US flexible needles were used to locate small muscular branches of the femoral nerve and 1 to locate the proximal stump. Intraoperatively, the localization wires allowed for safe and efficient dissection of proximal and distal nerve stumps in a significantly scarred and edematous plane. CONCLUSION US-guided needle-wire localization has shown promise in identifying the distal stumps and minimizing tissue dissection. Preoperative US guidance significantly aided in nerve repair for this severe injury without increasing morbidity.

Machine intelligence for nerve conduit design and production

Nerve guidance conduits (NGCs) have emerged from recent advances within tissue engineering as a promising alternative to autografts for peripheral nerve repair. NGCs are tubular structures with engineered biomaterials, which guide axonal regeneration from the injured proximal nerve to the distal stump. NGC design can synergistically combine multiple properties to enhance proliferation of stem and neuronal cells, improve nerve migration, attenuate inflammation and reduce scar tissue formation. The aim of most laboratories fabricating NGCs is the development of an automated process that incorporates patient-specific features and complex tissue blueprints (e.g. neurovascular conduit) that serve as the basis for more complicated muscular and skin grafts. One of the major limitations for tissue engineering is lack of guidance for generating tissue blueprints and the absence of streamlined manufacturing processes. With the rapid expansion of machine intelligence, high dimensional image analysis, and computational scaffold design, optimized tissue templates for 3D bioprinting (3DBP) are feasible. In this review, we examine the translational challenges to peripheral nerve regeneration and where machine intelligence can innovate bottlenecks in neural tissue engineering.