Potential of an artificial nerve graft containing Schwann cells for the treatment of a 20-mm nerve defect in rats.

OBJECTIVE: In a previous study, the authors showed that the migration of Schwann cells (SCs) through end-to-side (ETS) neurorrhaphy promotes axonal regrowth within an acellular nerve graft. In the present study, the authors investigated whether a similar strategy using an artificial nerve (AN) would allow reconstruction of a long nerve gap (20 mm) in rats. METHODS: Forty-eight 8- to 12-week-old Sprague Dawley rats were divided into control (AN) and experimental (SC migration-induced AN [SCiAN]) groups. Prior to the experiment, the ANs used in the SCiAN group were populated in vivo with SCs over a 4-week period by ETS neurorrhaphy onto the sciatic nerve. In both groups, a 20-mm sciatic nerve defect was reconstructed in an end-to-end fashion using 20-mm ANs. Sections from the nerve graft and distal sciatic nerve in both groups underwent assessments at 4 weeks for SC migration by immunohistochemical analysis and quantitative reverse transcription-polymerase chain reaction. At 16 weeks, axonal elongation was assessed by immunohistochemical analysis, histomorphometry, and electron microscopy. The number of myelinated fibers was counted, the g-ratio was calculated, and myelin sheath thickness and axon diameter were measured. Furthermore, functional recovery was evaluated at 16 weeks using the Von Frey filament test for sensory recovery and by calculating the muscle fiber area for motor recovery. RESULTS: The area occupied by SCs at 4 weeks and by axons at 16 weeks was significantly larger in the SCiAN group than in the AN group. Histomorphometric evaluation of the distal sciatic nerve revealed a significantly greater number of axons. At 16 weeks, plantar perception in the SCiAN group was significantly better, demonstrating improvement in sensory function. However, no tibialis anterior muscle motor improvement was observed in either group. CONCLUSIONS: The induction of SC migration into an AN by ETS neurorrhaphy is a useful technique for repairing 20-mm nerve defects in rats, with better nerve regeneration and sensory recovery. No motor recovery was observed in either group; however, motor recovery might require a longer period of time than the lifespan of the AN used in this study. Future studies should investigate whether structural and material reinforcement of the AN, to lower its decomposition rate, can improve functional recovery.

Physeal Distal Radial Fracture with Entrapment of the Tendons of Extensor Pollicis Longus and Extensor Digitorum Communis to Index Finger.

We report the entrapment of the extensor tendons following a growth plate fracture of the distal radius in a teenager. It is difficult to detect tendon entrapment at the fracture site immediately after the injury and diagnosis is typically made after fracture union when patients present with an inability to extend the thumb/reduced digital movement. A careful examination of our patient demonstrated some loss of digital motion and the plain radiographs, and computed tomographic scan showed incomplete reduction suggesting tendon entrapment. Early detection of the entrapped tendons allowed prompt release averting the need for tendon reconstruction. This report highlights the need for clinicians to maintain a high index of suspicion for tendon entrapment in patients with distal radius fractures that present with limited digital motion associated with incomplete reduction. An early diagnosis followed by the timely release can result in excellent outcomes. Level of Evidence: Level V (Therapeutic).

Neutrophils delay repair process in Wallerian degeneration by releasing NETs outside the parenchyma.

Although inflammation is indispensable for the repair process in Wallerian degeneration (WD), the role of neutrophils in the WD repair process remains unclear. After peripheral nerve injury, neutrophils accumulate at the epineurium but not the parenchyma in the WD region because of the blood-nerve barrier. An increase or decrease in the number of neutrophils delayed or promoted macrophage infiltration from the epineurium into the parenchyma and the repair process in WD. Abundant neutrophil extracellular traps (NETs) were formed around neutrophils, and its inhibition dramatically increased macrophage infiltration into the parenchyma. Furthermore, inhibition of either MIF or its receptor, CXCR4, in neutrophils decreased NET formation, resulting in enhanced macrophage infiltration into the parenchyma. Moreover, inhibiting MIF for just 2 h after peripheral nerve injury promoted the repair process. These findings indicate that neutrophils delay the repair process in WD from outside the parenchyma by inhibiting macrophage infiltration via NET formation and that neutrophils, NETs, MIF, and CXCR4 are therapeutic targets for peripheral nerve regeneration.

Simple surgical technique for minimizing the risk of extensor pollicis longus rupture following volar plate fixation of distal radial fracture: A case report.

INTRODUCTION AND IMPORTANCE: Extensor pollicis longus (EPL) tendon injury is a major complication in distal radial fracture repair. The risk factors for EPL tendon injury are prominent dorsal screws, direct intraoperative damage through drilling, and/or dorsal roof fragments. Herein, we introduce a simple technique to minimize the risk of EPL tendon rupture after volar plate fixation of distal radial fracture. CASE PRESENTATION: The patient was a 67-year-old woman with an intra-articular unstable distal radial fracture treated by volar locking plate fixation. Intraoperatively, we opened the third compartment after screw fixation. Because the screw had penetrated the floor of the third compartment, we moved the EPL tendon out of its groove and closed the third compartment by suturing the retinaculum. We confirmed that the EPL tendon was intact 7 years postoperatively, even though the screw was prominent in the third compartment. CLINICAL DISCUSSION: After volar plate fixation of the distal radial fracture, we partially open the third compartment through an approximately 2-cm-long incision on the ulnar side of Lister's tubercle. If the screw is prominent in the third compartment, we completely open the third compartment, take the EPL tendon out of its groove, and close the compartment by suturing the retinaculum. Our method was proved useful because the EPL tendon has remained intact for 7 years with the screw protruding into the third compartment. CONCLUSION: Our surgical technique is useful to prevent secondary EPL tendon rupture after distal radial plate fixation.

New Linked-Wire-Type External Fixator (the Ichi-Fixator System) for Metacarpal Fractures: Case Series and Literature Review.

Background: External fixator is an effective treatment option in the comminuted or unstable metacarpal fractures. The new linked-wire type of external fixator (the Ichi-Fixator System) developed for hand and wrist fractures enables fine adjustment of the fixation under fluoroscopic inspection through small screws inside the fixator fitted externally. This technique is designed to reinforce the stability and rigidity of conventional percutaneous Kirchner wire fixation. The aim of this study is to assess the effectiveness of the fixator for comminuted or unstable metacarpal fractures through the evaluation of short-term results in ten cases. Methods: Patients were fixated with fixator pins and metal clamps using the Ichi-Fixator System. All patients were then examined for post-operative complications, functional recovery, visual analogue scale (VAS) score, and the Quick Disabilities of the Arm, Shoulder, and Hand (Q-DASH) score at the end of the final follow-up consultation. Results: Operative treatment using the Ichi-Fixator System facilitates anatomical reduction and allows immediate full mobilization, producing good outcomes. No infections were observed in all cases, including those at pin insertion sites. There were no implant failure and nonunion. Patients could perform all routine activities with normal grip strength and retained a full range of hand motion without pain. This treatment method with improved postoperative comfort would allow immediate return to work, which would clearly boost patient satisfaction. Conclusions: Ichi-Fixator System is considered to be useful for the treatment of metacarpal fractures, and this will provide a new surgical option for all hand fractures.

Feasibility of pre- and postoperative arthroscopic assessments with internal fixation for growth plate injury of the distal tibia: three case reports and a literature review.

BACKGROUND: Inappropriate treatment of growth plate injury may cause complications such as malunion or early arrest of the growth plate. Identification of intra-articular lesions is mandatory in patients with a growth plate injury of the distal tibia. Arthroscopic assessment is useful in identifying intra-articular injury. We report three cases of intra-articular growth plate injury of the distal tibia that were treated via internal fixation with arthroscopic assessment in our hospital. MATERIALS AND METHODS: All three cases were performed pre- and postoperative arthroscopic assessment and open reduction and internal fixation with a cannulated cancellous screw (CCS; Meira, Japan). All patients were then examined for postoperative complications, functional recovery, at the end of the final follow-up consultation. RESULTS: Intraoperatively, a small cartilage injury was found in the non-fracture area in two cases; the remaining case had a reversed cartilage fragment at the talus, which was arthroscopically removed. CONCLUSIONS: Arthroscopic assessment followed by internal fixation is a useful minimally invasive method for the identification of intra-articular lesions such as osteochondral injury or free bodies.

Open Reduction and Intrafragmentary Compression Fixation with External Fixator (the Ichi-Fixator) Treatment of Distal Phalangeal Nonunion.

The nonunion of distal phalangeal communized fracture is relatively rare in hand fractures. However, if it occurred, the surgical treatment is quite difficult because of small piece of fragmentations. We developed a new fixation method that involves the insertion of two wires and external wire compression fixation using a metal clamp. The aim of this technique was to increase the compression force between fragments and rigidity of conventional percutaneous Kirschner wire fixation. Here, we present a patient with the nonunion of distal phalangeal communized fracture who was satisfactorily treated with open reduction and percutaneous interfragmentary compression fixation with a linking external wire fixator (the Ichi-Fixator system). Such a treatment that enables compression fixation for communized distal phalangeal fracture of nonunion will clearly boost bone healing. Linked external wire-type compression fixator (the Ichi-Fixator system) enables enhanced security of fixation and facilitates the bone healing.

Treatment of an intraarticular comminuted fracture of the base of the proximal phalanx in a ring finger using the Ichi-Fixator external fixator system: A case report.

INTRODUCTION: Comminuted fractures involving the articular surface of the base of the proximal phalanx are relatively rare. We treated a patient with this type of fracture by open reduction and internal fixation with a locked-wire-type external fixator (Ichi-Fixator System). PRESENTATION OF CASE: A 45-year-old man was injured because his ring finger was kicked during a Futsal game. Radiographs and computed tomography revealed a comminuted intraarticular fracture of the proximal phalanx of this ring finger. We treated the fracture with open reduction and K-wires and external fixation. We removed the K-wire and external fixator 5 weeks postoperatively and initiated range of motion exercises. Five months postoperatively, his finger motion was fully recovered without restriction. DISCUSSION: Comminuted intraarticular fractures of the base of the proximal phalanx are usually treated with plating. Complications such as interference with excursion of the central slip and lateral bands, extensor tendon rupture, and plate prominence have been reported in these fractures. In our patient, the Ichi-Fixator System was useful as a distraction apparatus for metacarpophalangeal joint fixation. CONCLUSION: A comminuted intra-articular fracture of the base of the proximal phalanx was treated successfully using the Ichi-Fixator system.

Patellar Tendon Avulsion with Tibial Tuberosity Sleeve Fragment.

Rupture of the patellar tendon is relatively rare. We report a case of patellar tendon avulsion with a tibial tuberosity sleeve fragment in pediatric patient. In pediatric patient, diagnosis is sometimes difficult due to uncompleted ossification. In the present case, which involved the presence of a small fleck of bone from tibia, we were able to attain a diagnosis using the Koshino-Sugimoto index and MRI and easily determine the optimal treatment with the use of the suture anchor and tension band wiring method.

Biomechanical evaluation of a transcondylar screw from the dorsolateral plate support on the stabilization of orthogonal plate configuration in distal humeral fracture.

INTRODUCTION: Intra-articular distal humeral fractures involving both columns require double-plate fixation. In orthogonal plate fixation, screws from the medial plate reach the radial column, while screws from the dorsolateral plate run posterior-anterior, not creating interdigitation. The Synthes LCP-DHP system has an orthogonal plate configuration that enables dorsolateral plating with support, as the radial and ulnar columns are linked via interdigitation of the distal screws. We hypothesized that the transcondylar screw from the posterolateral plate, which interdigitates with screws from the medial plate, enables more rigid stabilization of orthogonal plating in distal humeral AO type C fractures. METHODS: A previous study reported the biomechanical properties of orthogonal plate fixation using an AO type 13-C2.3 intra-articular fracture model with a 1-cm supracondylar gap using artificial bones (Kudo et al., Injury, 2016). We performed a biomechanical study of the dorsolateral plate with support, and inserted one 2.7-mm locking screw through the support in the lateral-to-medial direction, creating interdigitation of the distal screws. A 0-200 N axial load was applied separately to the radial and ulnar columns. We calculated the stiffness of both columns, and the anterior displacement of the condylar fragment. We compared the biomechanical properties of orthogonal plating with versus without interdigitation. RESULTS: There were no significant differences between the two groups in radial or ulnar axial compression. The ulnar column was stiffer than the radial column in both groups. There were no significant differences between groups in the angular displacements of the capitellum or trochlea. The capitellum moved more anteriorly than the trochlea during axial compression in both groups. DISCUSSION: The radial and ulnar columns were linked via interdigitation of the distal screws by adding one transcondylar screw from the dorsolateral plate, which did not affect radial column stiffness or capitellar anterior movement under axial compression. In the orthogonal configuration, axial compression induced more anterior displacement of the capitellum than the trochlea, which may induce secondary fragment or screw dislocation on the dorsolateral plate or nonunion at the supracondylar level. CONCLUSIONS: The transcondylar screw from the dorsolateral plate did not affect axial compression of the radial column or capitellar anterior displacement.

The Utility of the Knotless Suture Fixation for Bilateral Second Toe Transplantation in Traumatic Multiple-Digit Amputation.

Toe-to-hand transfer is a useful reconstruction method after finger amputation. We report a case of multiple-digit amputation, reconstructed with bilateral second-toe transfer. In this study, we used a knotless suture fixation system (ZipTight™; Arthrex Inc., FL, USA) which effectively closed the wound and reduce the amount of dead space. Both second-toe transplantations survived. The feet were asymptomatic with good cosmetic outcomes. Although the reconstructed digits had limited range of motion, the patient was able to return to work. Knotless suture fixation system may be one of the effective methods for closing the donor site wound in second-toe transplantations.

Masquelet technique for the treatment of acute osteomyelitis of the PIP joint caused by clenched-fist human bite injury: A case report.

INTRODUCTION: The Masquelet technique is a well-known and efficient procedure for lower limb soft tissue reconstruction after severe osteomyelitis requiring bone excision. However, this technique is rarely used in the hand. PRESENTATION OF CASE: The patient was 38-year-old man. We used this technique to reconstruct a proximal interphalangeal (PIP) joint osteochondral defect after osteomyelitis caused by clenched-fist human bite injury. The pathogen was Prevotella intermedia, which is an anaerobic pathogenic bacterium involved in periodontal infections and is a black-pigmented periodontal pathogen. Following completion of the Masquelet method, the bone remodeled at an angle at the PIP joint. DISCUSSION: Prevotella intermedia is known as Bacteroides melaninogenicus subsp. intermedius. When the infection site is black-pigmented, this pathogen is highly suspected. The Masquelet technique is rarely used in the hand, and when used, it has been in a straight fashion in the hand. We were able to reconstruct a more anatomical, bent PIP joint, and the fixed angle of the PIP joint at 40° of flexion using Masquelet technique. CONCLUSION: The angled joint resulting from this technique created a relatively normal permanently bent PIP joint.

New Locked-Wire-Type External Fixator (the Ichi-Fixator) for Fourth and Fifth Carpometacarpal Joint Dislocation.

We developed a new fixation method that involves the insertion of two wires and external wire fixation using a metal clamp. The aim of this technique was to increase the stability and rigidity of conventional percutaneous Kirchner wire fixation. Here, we present a patient with dislocation of the fourth and fifth carpometacarpal joints who was satisfactorily treated with closed reduction and percutaneous fixation with a linking external wire fixator (Ichi-Fixator). Operative treatment using the Ichi-Fixator system facilitates anatomical reduction and immediate full mobilization, resulting in good outcomes. The patient could perform all routine activities with normal grip strength and a full range of hand motion without pain. Such a treatment that improves comfort after the operation and may allow an immediate return to work will clearly boost patient satisfaction. Linked external wire-type fixation enables enhanced security of fixation, facilitates postoperative mobilization, and may allow an immediate return to work.

Biomechanical properties of orthogonal plate configuration versus parallel plate configuration using the same locking plate system for intra-articular distal humeral fractures under radial or ulnar column axial load.

INTRODUCTION: Previous reports have questioned whether an orthogonal or parallel configuration is superior for distal humeral articular fractures. In previous clinical and biomechanical studies, implant failure of the posterolateral plate has been reported with orthogonal configurations; however, the reason for screw loosening in the posterolateral plate is unclear. The purpose of this study was to evaluate biomechanical properties and to clarify the causes of posterolateral plate loosening using a humeral fracture model under axial compression on the radial or ulnar column separately. And we changed only the plate set up: parallel or orthogonal. MATERIALS AND METHODS: We used artificial bone to create an Association for the Study of Internal Fixation type 13-C2.3 intra-articular fracture model with a 1-cm supracondylar gap. We used an anatomically-preshaped distal humerus locking compression plate system (Synthes GmbH, Solothurn, Switzerland). Although this is originally an orthogonal plate system, we designed a mediolateral parallel configuration to use the contralateral medial plate instead of the posterolateral plate in the system. We calculated the stiffness of the radial and ulnar columns and anterior movement of the condylar fragment in the lateral view. RESULTS: The parallel configuration was superior to the orthogonal configuration regarding the stiffness of the radial column axial compression. There were significant differences between the two configurations regarding anterior movement of the capitellum during axial loading of the radial column. DISCUSSION: The posterolateral plate tended to bend anteriorly under axial compression compared with the medial or lateral plate. We believe that in the orthogonal configuration axial compression induced more anterior displacement of the capitellum than the trochlea, which eventually induced secondary fragment or screw dislocation on the posterolateral plate, or nonunion at the supracondylar level. In the parallel configuration, anterior movement of the capitellum or trochlea was restricted because of the angular stability of the plate and locking screws in the condyle. CONCLUSIONS: The posterolateral plate tended to bend anteriorly under axial compression of the radial column in the orthogonal configuration, which led to secondary displacement of the posterolateral plate and eventual screw loosening.

Erratum: Distal Radius Isoelastic Resurfacing Prosthesis: A Preliminary Report.

[This corrects the article DOI: 10.1055/s-0035-1556855.].

Robotically assisted harvest of the latissimus dorsi muscle: A cadaver feasibility study and clinical test case.

The applications of robotic surgery have quickly spread into a variety of surgical fields. Interest in robotic endoscopic surgery is high because of the small size of the incisions, cosmetic advantages, less invasive surgical techniques, decreased scar tissue, shorter duration of hospitalization and increased cost-effectiveness. We will describe an anatomical feasibility study and a clinical test case of robotically assisted pedicled transposition of the latissimus dorsi muscle.

Robot-assisted C7 nerve root transfer from the contralateral healthy side: A preliminary cadaver study.

Patients with cerebral palsy and spastic hemiplegia may have extremely poor upper extremity function. Unfortunately, many current therapies and treatments for patients with spastic hemiplegia offer very limited improvements. One innovative technique for treating these patients is the use a contralateral C7 nerve root transfer to neurotize the C7 nerve root in the affected limb. This may result not only in less spasticity in the affected limb, but also improved control and motor function vis-a-vis the new connection to the normal cerebral hemisphere. However, contralateral C7 transfers can require large incisions and long nerve grafts. The aim of this study was to test the feasibility of a contralateral C7 nerve root transfer procedure with the use of a prevertebral minimally invasive robot-assisted technique. In a cadaver, both sides of the C7 root were dissected. The right recipient C7 root was resected as proximally as possible, while the left donor C7 root was resected as distally as possible. With the use of the da Vinci (®) SI surgical robot (Intuitive Surgical ™, Sunnyvale, CA, USA), we were able to eliminate the large incision and use a much shorter nerve graft when performing contralateral C7 nerve transfer.

Distal Radius Isoelastic Resurfacing Prosthesis: A Preliminary Report.

Background Here we present a preliminary case series of unicompartmental isoelastic resurfacing prosthesis of the distal radius to treat comminuted articular fractures of osteoporotic elderly patients. Materials and Methods Our study included 12 patients, mean age 76 years, who presented with comminuted osteoporotic distal radius fracture. Because of the severity of injury and poor bone quality; osteosynthesis was not deemed to be a good option. Description of Technique The surgery was performed through a dorsal approach. The subchondral bone of the entire distal radial articular was excised and a unicompartmental prosthesis was applied. Results At an average follow-up of 32 months, the pain was 2.8/10, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) 37.4/100, grip strength in neutral 49.9%, in supination 59.0%, and in pronation 56.2% of the contralateral normal side. The wrist ranges of motion in flexion and extension were 56.1% and 79.3%, in supination and pronation 87.7% and 91.0% of the contralateral normal side. Two patients experienced a complex regional pain syndrome (CRPS) type II; these resolved spontaneously. One patient experienced distal radioulnar joint (DRUJ) stiffness, which improved after an ulna head resection. Finally, one patient required revision surgery after a secondary traumatic fracture. Radiographically; the average volar tilt was 9.8°; the average of radial inclination was 11.6°. Conclusion The concept of a unicompartmental isoelastic resurfacing prosthesis offers a promising option for the treatment of comminuted, osteoporotic distal radius articular fractures of elderly patients. Level of Evidence IV.

Hyperparathyroidism-related extensor tenosynovitis at the wrist: a general review of the literature.

Extensor tenosynovitis often occurs accompanying with rheumatoid arthritis, gout, trauma, mycobacterium and dialysis-related amyloidosis. However, there is no recognition of extensor tenosynovitis accompanying with hyperparathyroidism. The purpose of this general review was to describe the clinical condition and to report the results of surgical intervention in the extensor tenosynovitis at the wrist related to hyperparathyroidism. Hyperparathyroidism is thought to be a rare disease in adult. Although renal symptoms are the commonest symptom, musculoskeletal complaints also occur in hyperparathyroidism. From our general review, hyperparathyroidism deserves consideration in the differential diagnosis of extensor tenosynovitis at the wrist.

A comparative study about ionizing radiation emitted during radiological "skyline" view of the wrist in pronation versus supination.

The dorsal tangential view to the distal radius or "skyline," used to control the length of the screws for the ORIF with volar plates, is carried out in supination (fluoroscope vertical) or in pronation (fluoroscope horizontal). The purpose of this study was to compare the dose of ionizing radiation emitted during a "skyline" view in supination versus pronation. A "skyline" was performed on 14 fresh cadaveric wrists. In group 1, the fluoroscope was positioned vertically and the wrist was held in supination. In group 2, the fluoroscope was positioned horizontally and the wrist held in pronation. The average dose of ionizing radiation was 0.9286 cGy/cm(2) (group 1) and 0.8751 cGy/cm(2) (group 2). The difference was not statistically significant. Overall, the emitted dose for the "skyline" is negligible compared to that of a standard wrist radiography with no difference between the vertical and horizontal positioning. Peroperatively, the vertical "skyline" seems easier to setup, less time consuming and less prone to asepsis faults.