Biomechanical Evaluation of a New Suture Button Technique for Reduction and Stabilization of the Distal Tibiofibular Syndesmosis.

BACKGROUND: Stabilization methods for distal tibiofibular syndesmotic injuries present risk of malreduction. We compared reduction accuracy and biomechanical properties of a new syndesmotic reduction and stabilization technique using 2 suture buttons placed through a sagittal tunnel in the fibula and across the tibia just proximal to the incisura with those of the conventional method. METHODS: Syndesmotic injury was created in 18 fresh-frozen cadaveric lower leg specimens. Nine ankles were repaired with the conventional method and 9 with the new technique. Reduction for the conventional method was performed using thumb pressure under direct visualization and for the new method by tightening both suture buttons passed through the fibular and tibial tunnels. Computed tomography was used to assess reduction accuracy. Torsional resistance, fibular rotation, and fibular translation were evaluated during biomechanical testing. RESULTS: The new technique showed less lateral translation of the fibula on CT measurements after reduction (0.06 ± 0.06 mm) than the conventional method (0.26 ± 0.31 mm), P = .02. The new technique produced less fibular rotation during internal rotation after 0 cycles (new -2.4 ± 1.4 degrees; conventional -5.0 ± 1.2 degrees, P = .001), 100 cycles (new -2.1 ± 1.9 degrees; conventional -4.6 ± 1.4 degrees, P = .01), and 500 cycles (new -2.2 ± 1.6 degrees; conventional -5.3 ± 2.5 degrees, P = .01) and during external rotation after 100 cycles (new 3.9 ± 3.3 degrees; conventional 5.9 ± 3.5 degrees, P = .02) and 500 cycles (new 3.3 ± 3.2 degrees; conventional 6.3 ± 2.6 degrees, P = .03). Fixation failed in 3 specimens. CONCLUSION: The new syndesmotic reduction and fixation technique resulted in more accurate reduction of the fibula in the tibial incisura in the coronal plane and better rotational stability compared with the conventional method. CLINICAL RELEVANCE: This new technique of syndesmosis reduction and stabilization may be a reliable alternative to current methods.

Extensive Synovial Chondromatosis Involving All Flexor Tendons in the Tarsal Tunnel: A Case Report.

Synovial chondromatosis is a rare condition characterized by benign chondrogenic meta- plasia of extra-articular synovial tissue. It usually affects a single tendon sheath of the hand or foot. This report describes a rare case with extensive synovial chondromatosis affecting all flexor tendons in the tarsal tunnel, its radiological features, surgical treatment, and clinical outcome. The authors present a unique case of extensive synovial chondromatosis in a 48-year-old male involving the tendon sheaths of the flexor hallucis longus, flexor digitorum longus, and posterior tibialis tendons, at the level of the tarsal tunnel, with extension into the plantar aspect of the foot. The patient initially presented with symptoms of tarsal tunnel compression and was found to have a 4-cm mass in the posteromedial aspect of the ankle. The presumptive diagnosis of synovial chondromatosis was made based on radiographic and magnetic resonance imaging evidence. The patient underwent surgical resection of the tumor, as well as tarsal tunnel release and gastrocnemius recession. The diagnosis was confirmed postoperatively by surgical histopathology. The postoperative course of the patient was uncomplicated and his tarsal tunnel symptoms resolved. This represents a case of extensive synovial chondromatosis involving all flexor tendons in the tarsal tunnel that was correctly diagnosed by clinical and imaging findings, which required early surgical resection to avoid long-term neurovascular complications.

Extensive Synovial Chondromatosis Involving All Flexor Tendons in the Tarsal Tunnel: A Case Report / Condromatose sinovial extensa envolvendo todos os tendões do túnel do tarso: relato de caso

Abstract Synovial chondromatosis is a rare condition characterized by benign chondrogenic metaplasia of extra-articular synovial tissue. It usually affects a single tendon sheath of the hand or foot. This report describes a rare case with extensive synovial chondromatosis affecting all flexor tendons in the tarsal tunnel, its radiological features, surgical treatment, and clinical outcome. The authors present a unique case of extensive synovial chondromatosis in a 48-year-old male involving the tendon sheaths of the flexor hallucis longus, flexor digitorum longus, and posterior tibialis tendons, at the level of the tarsal tunnel, with extension into the plantar aspect of the foot. The patient initially presentedwith symptoms of tarsal tunnel compression and was found to have a 4-cm mass in the posteromedial aspect of the ankle. The presumptive diagnosis of synovial chondromatosiswasmadebased on radiographic and magnetic resonance imaging evidence. The patient underwent surgical resection of the tumor, aswell as tarsal tunnel releaseandgastrocnemius recession. The diagnosiswas confirmed postoperatively by surgical histopathology. The postoperative course of the patient was uncomplicated and his tarsal tunnel symptoms resolved. This represents a case of extensive synovial chondromatosis involving all flexor tendons in the tarsal tunnel that was correctly diagnosed by clinical and imaging findings, which required early surgical resection to avoid long-term neurovascular complications.

Resumo A condromatose sinovial é uma condição rara caracterizada por metaplasia condrogênica benigna do tecido sinovial extra-articular, que geralmente afeta uma única bainha tendínea da mão ou do pé. O objetivo é relatar o caso raro de um paciente com diagnóstico de condromatose sinovial extensa afetando todos os tendões flexores na topografia do túnel do tarso, suas características radiológicas, tratamento cirúrgico e desfecho clínico. Os autores apresentam um caso único de condromatose sinovial extensa em um homem de 48 anos envolvendo as bainhas dos tendões flexor longo do hálux, flexor longo dos dedos e tibial posterior, na topografia do túnel do tarso, com extensão para a região plantar do retropé. O sintoma inicial foi de compressão neurovascular (síndrome do túnel do tarso). A suspeita diagnóstica foi condromatose sinovial com base em evidências radiográficas e de ressonância magnética. O paciente foi submetido a ressecção cirúrgica do tumor, bem como a liberação do túnel tarsal e alongamento do tendão dos gastrocnêmios. O diagnóstico foi confirmado por exame histopatológico do espécime colhido no período intraoperatório. A evolução pósoperatória do paciente ocorreu sem complicações e os sintomas da síndrome do túnel do tarso cessaram. Os autores relatam um caso de condromatose sinovial extensa envolvendo todos os tendões flexores do túnel do tarso, corretamente diagnosticado por achados clínicos e radiológicos e que necessitou de ressecção cirúrgica precoce para evitar complicações neurovasculares em longo prazo.

The topographic specificity of muscle reinnervation predicts function.

Functional testing has assumed a progressively dominant role in validating the success of experimental nerve repair. Results obtained in one model, however, cannot predict the results in others because they reflect the coordinated interaction of several muscles across multiple joints. As a result, many combinations of topographically correct and incorrect muscle reinnervation could produce the same result. We have developed a binary model in which elbow flexors and extensors are reinnervated, and elbow flexion and extension are the functions tested. The musculocutaneous and radial nerves of Lister-Hooded rats were subjected to axonotmetic injuries that produced increasing degrees of axonal misdirection at the site of injury ranging from simple crush to transection and rotational offset of proximal and distal stumps. Elbow function was tested with a device that requires coordinated elbow extension to reach sugar pellets and flexion to return them to the mouth. After 12 weeks of regeneration, motoneurons projecting to the distal musculocutaneous nerve were retrogradely labelled with WGA-Ruby and scored regarding their location within musculocutaneous or radial motoneuron pools. The severity of axonal misdirection resulting from the initial surgery was mirrored by progressive degrees of inappropriate reinnervation of the musculocutaneous nerve by radial nerve axons. The specificity of reinnervation predicted elbow function (r = 0.72), whereas the number of motoneurons regenerating did not. This model is thus well suited to study the interaction of regeneration specificity and function across a single joint, and to produce data that can be generalized more broadly than those obtained from more complex models.

Missing consent forms in the preoperative area: a single-center assessment of the scope of the problem and its downstream effects.

Missing consent forms at surgery can lead to delays in patient care, provider frustration, and patient anxiety. We sought to assess the scope and magnitude of this problem at our institution. We surveyed key informants to determine the frequency and effect of missing consent forms. We found that 66% of patients were missing signed consent forms at surgery and that this caused a delay for 14% of operative cases. In many instances, the missing consent forms interfered with team rounds and resident educational activities. In addition, residents spent less time obtaining consent and were often uncomfortable obtaining consent for major procedures. Finally, 40% of faculty felt dissatisfied with resident consent forms, and more than two-thirds felt patients were uncomfortable with being asked for consent by residents. At our center, missing consent forms led to delayed cases, burdensome and inadequate consent by residents, and extra work for nursing staff.

Dorsal radiocarpal dislocation in a patient with Goldenhar syndrome: case report.

BACKGROUND: Fracture-dislocations of the carpus are rare, generally occurring after high-energy trauma. Goldenhar syndrome is among a group of genetic abnormalities associated with radial limb defects. We present a case of a dorsal radiocarpal dislocation in a patient with Goldenhar syndrome after a low-energy fall. To our knowledge, there has been no previous report of radiocarpal dislocation in the setting of Goldenhar syndrome. METHODS: This patient with Goldenhar syndrome had a dorsal radiocarpal dislocation in the setting of an absent scaphoid and dysplastic distal radius. A computed tomography scan, recognized as a useful modality to evaluate the wrist and scaphoid, was used to rule out any other osseous trauma or avulsion fractures. RESULTS: Closed reduction and 6 weeks of immobilization resulted in a successful treatment. CONCLUSIONS: The incidence of radiocarpal dislocations in patients with Goldenhar syndrome and the appropriate long-term treatment for patients with Goldenhar syndrome with radiocarpal dislocations require further investigation.

An in vitro model of adult mammalian nerve repair.

The role of pathway-derived growth factors in the support of peripheral axon regeneration remains elusive. Few appropriate knock-out mice are available, and gene silencing techniques are rarely 100% effective. To overcome these difficulties, we have developed an in vitro organotypic co-culture system that accurately models peripheral nerve repair in the adult mammal. Spinal cord sections from P4 mice that express YFP in their neurons are used to innervate segments of P4 peripheral nerve. This reconstructed ventral root is then transected and joined to a nerve graft. Growth of axons across the nerve repair and into the graft can be imaged repeatedly with fluorescence microscopy to define regeneration speed, and parent neurons can be labeled in retrograde fashion to identify contributing neurons. Nerve graft harvested from adult mice remains viable in culture by both morphologic and functional criteria. Motoneurons are supported with GDNF for the first week in culture, after which they survive axotomy, and are thus functionally adult. This platform can be modified by using motoneurons from any genetically modified mouse that can be bred to express XFP, by harvesting nerve graft from any source, or by treating the culture systemically with antibodies, growth factors, or pathway inhibitors. The regeneration environment is controlled to a degree not possible in vivo, and the use of experimental animals is reduced substantially. The flexibility and control offered by this technique should thus make it a useful tool for the study of regeneration biology.

Nueva técnica artroscópica para la liberación del retináculo lateral de la rodilla / New arthroscopic technical for the liberation to the lateral relaese of the knee

La cirugía artroscópica de rodilla ha llegado a ser un procedimiento quirúrgico imprescindible para varias patologías que afecta a esta articulación y permite, dependiendo de la experticia del cirujano, la obtención de resultados óptimos en la mayoría de los casos. Con el trascurrir del tiempo esta técnica sa ha enriquecido con instrumentos y métodos que facilitan aún más el logro de resultados satisfactorios y por ende la reducción del número de complicaciones postoperatorias. Uno esos métodos es el sistema de vaporización por radiofrecuencia, que consiste en la aplicación de un generador bipolar de radiofrecuencia especialmente diseñado para uso artroscópico en la remoción de tejido blando. También permite realizar cortes precisos, minimiza el daño a tejidos colaterales y aumenta la eficiencia de los procedimientos, ya que su acción vaporiza el tejido y lo coagula en forma simúltanea. (La energía electromagnética es el flujo de electrones que viaja a la velocidad de la luz en un circuito alternante. Frecuencia es el número de veces que una onda de electrones oscila durante un segundo de tiempo. El movimiento de positivos a negativo genera un campo electromagnético y una radiación productora de calor). La finalidad de este trabajo es describir una variación de la técnica de liberación de retináculo literal, con el uso del sistema de vaporización y demostrar las ventajas respecto a otras técnicas con relación al procedimiento quirúrgico y a la evolución postoperatoria de los pacientes