A Novel External Fixation Technique for Injuries of the Proximal Interphalangeal Joint.

Digital external fixation is often used for the management of complex injuries involving the proximal interphalangeal joint, including pilon fractures of the middle phalanx base and unstable fracture-dislocations. Several dynamic "homemade" constructs have been described which utilize only K-wires and rubber bands and allow early range of motion within the construct. Although these constructs are inexpensive and their application is fairly straightforward, their designs pose a few potential problems when the construct is stressed during rehabilitation efforts. These designs utilize a blocking K-wire which relies on pin-to-pin contact to maintain reduction and creates unnecessary friction that can impede motion and result in pin loosening in bone. Furthermore, rubber band rupture can occur and destabilizes the construct. Here we present a novel technique which utilizes only K-wires and K-wire caps, provides adequate joint distraction and stabilization throughout the arc of motion, and avoids the aforementioned pitfalls of existing designs.

Biomechanical Comparison of Volar Fixed-Angle Locking Plates for AO C3 Distal Radius Fractures: Titanium Versus Stainless Steel With Compression.

PURPOSE: To determine biomechanical differences between a fixed-angle locking volar titanium plate (VariAx; Stryker, Kalamazoo, MI) and a fixed-angle compression locking volar stainless steel plate (CoverLoc Volar Plate; Tornier, Amsterdam, Netherlands) in the fixation of simulated AO C3 distal radius fractures. METHODS: Eighteen cadaveric upper extremities (9 matched pairs) with an average age of 54 years were tested. A 4-part AO C3 fracture pattern was created in each specimen. The fractures were reduced under direct vision and fixed with either the fixed-angle locking volar titanium plate or the fixed-angle compression locking volar stainless steel plate. Motion tracking analysis was then performed while the specimens underwent cyclic loading. Changes in displacement, rotation, load to failure, and mode of failure were recorded. RESULTS: The fragments, when secured with the fixed-angle compression locking stainless steel construct, demonstrated less displacement and rotation than the fragments secured with the fixed-angle locking titanium plate under physiological loading conditions. In the fixed-angle compression locking stainless steel group, aggregate displacement and rotation of fracture fragments were 5 mm and 3° less, respectively, than those for the fixed-angle locking titanium group. The differences between axial loads at mechanical failure and stiffness were not statistically significant. The compression locking stainless steel group showed no trend in mode of failure, and the locking titanium plate group failed most often by articular fixation failure (5 of 9 specimens). CONCLUSIONS: The fixed-angle compression locking stainless steel volar plate may result in less displacement and rotation of fracture fragments in the fixation of AO C3 distal radius fractures than fixation by the fixed-angle locking volar titanium plate. However, there were no differences between the plates in mechanical load to failure and stiffness. CLINICAL RELEVANCE: Fixation of distal radius AO C3 fracture patterns with the fixed-angle compression locking stainless steel plate may provide improved stability of fracture fragments.

Flexor tendon repair with a knotless, bidirectional barbed suture: an in vivo biomechanical analysis.

PURPOSE: To compare and analyze biomechanical properties and histological characteristics of flexor tendons either repaired by a 4-strand modified Kessler technique or using barbed suture with a knotless repair technique in an in vivo model. METHODS: A total of 25 chickens underwent surgical transection of the flexor digitorum profundus tendon followed by either a 4-strand Kessler repair or a knotless repair with barbed suture. Chickens were randomly assigned to 1 of 3 groups with various postoperative times to death. Harvested tendons were subjected to biomechanical testing or histologic analysis. RESULTS: Harvested tendons revealed failures in 25% of knotless repairs (8 of 32) and 8% of 4-strand Kessler repairs (2 of 24). Biomechanical testing revealed no significant difference in tensile strength between 4-strand Kessler and barbed repairs; however, this lack of difference may be attributed to lower statistical power. We noted a trend toward a gradual decrease in strength over time for barbed repairs, whereas we noticed the opposite for the 4-strand Kessler repairs. Mode of failure during testing differed between repair types. The barbed repairs tended toward suture breakage as opposed to 4-strand Kessler repairs, which demonstrated suture pullout. Histological analysis identified no difference in the degree of inflammation or fibrosis; however, there was a vigorous foreign body reaction around the 4-strand Kessler repair and no such response around the barbed repairs. CONCLUSIONS: In this model, knotless barbed repairs trended toward higher in vivo failure rates and biomechanical inferiority under physiologic conditions, with each repair technique differing in mode of failure and respective histologic reaction. We are unable to recommend the use of knotless barbed repair over the 4-strand modified Kessler technique. CLINICAL RELEVANCE: For the repair techniques tested, surgeons should prefer standard Kessler repairs over the described knotless technique with barbed suture.

Graphene oxide based magnetic nanocomposites for efficient treatment of breast cancer.

The present work reports a simple one step synthesis of nanoscale graphene oxide magnetic composites (GO-IO) using ferrofluid (GO-IOF). The obtained GO-IO were compared with GO-IO obtained from in situ (GO-IOI) methods. Anastrozole (ANS) was loaded on the GO-IOI and GO-IOF via simple stirring method to form GO-IOA and GO-IOFA respectively. These GO-IO prepared by two techniques were characterized using spectroscopic techniques and vibrating sample magnetometer (VSM) analysis. Particle size and potential were measured using Malvern Zetasizer. Scanning electron microscopy (SEM) was used for studying the surface morphology of GO-IO, and in addition to this elemental analysis was also performed for confirming the presence of iron. The cell viability assay was carried out using the MCF-7 cell line. It revealed that GO-IOFA had reasonably high cytotoxicity (49.7%) compared to GO (13.1%), ANS (16.6), GO-IOI (13%), GO-IOF (13.6) and GO-IOIA (18.34%). Both, GO-IOIA and GO-IOFA showed improved cytotoxicity when compared with pure ANS. GO-IOF were found to exhibit superior magnetic activity due to higher iron content along with smaller particle size and higher loading efficiency compared to GO-IOI. The overall effect suggests that GO-IO can be utilized as efficient carriers for the loading of chemotherapeutic agents.

Pedicle and free flaps for painful nerve.

Treatment of the chronic painful nerve by pedicled or free tissue transfer is a complex surgical procedure, requiring specialized microsurgical training and technique. This procedure is indicated only in patients who have had repeated failure of simpler, conventional procedures. Patients with chronic painful peripheral nerves may be potentially salvaged by external neurolysis and circumferential wrapping of the involved segments of nerve with well-vascularized pedicled or free flaps of fascia, subcutaneous fatty tissue, omentum or muscle, or by the replacement of superficial hypersensitive cutaneous areas and nerves with the same tissues.