Transcutaneous CO2 Pressure Monitoring Increases Salvage Rates after Free Tissue Transplantation for Extremity Reconstruction.

Although free tissue transplantation (FTT) is an essential technique in extremity functional reconstruction, postoperative blood flow disturbance is one of the critical complications leading to transplanted tissue necrosis. Early detection of this complication may prevent tissue failure by prompt improvement of blood flow. The aim of this study was to determine whether transcutaneous carbon dioxide pressure (TcPCO2) monitoring increases the salvage rates after FTT. Methods: We retrospectively reviewed 75 consecutive patients who underwent FTT for extremity reconstruction with TcPCO2 monitoring postoperatively between December 2016 and September 2021. Results: Extremity reconstruction was performed in 53 cases due to trauma, 20 cases due to infection, and two cases due to tumor resection for tissue defects. The overall success rate of the FTT was 98.7%, with 13 complications. Of the 11 patients who underwent reoperation, nine had thrombosis and two had vascular strangulation. However, when reoperation was decided, none of the reoperation cases still exhibited any deterioration in the Doppler or clinical assessment. All reoperated cases were salvaged. Of the two patients who did not undergo reoperation, one had failed flaps and one had partial skin necrosis. With a TcPCO2 cutoff value of 70 mm Hg, the sensitivity and specificity for detecting complications due to impaired blood flow were 100% and 93.5%, respectively. Conclusions: TcPCO2 monitoring was performed after FTT for extremity reconstruction, and all cases of reoperation were salvaged. TcPCO2 monitoring can detect impaired postoperative blood flow critically earlier than clinical assessments and may increase salvage rates of transplanted tissue.

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.

Supplemented Chondroitin Sulfate and Hyaluronic Acid Suppress Mineralization of the Chondrogenic Cell Line, ATDC5, via Direct Inhibition of Alkaline Phosphatase.

Chondroitin sulfate (CS) is a sulfated polysaccharide produced by chondrocytes. Alkaline phosphatase (ALP) is an important enzyme involved in the mineralization of chondrocytes. In recent years, it has been reported that CS regulates the differentiation of various cells. In this study, we investigated the effect of supplemented CS on ALP activity and mineralization of the chondrogenic cell line, ATDC5. In addition, hyaluronic acid (HA), a non-sulfated and acidic polysaccharide, was used in comparison to CS. CS and HA significantly suppressed ALP activity without affecting ATDC5 cell proliferation. In addition, although the inhibition of ALP activity was observed at every time point, Alp mRNA expression level was not affected by CS. The suppressive effect of CS on ALP activity was abrogated by pre-treatment with chondroitinase ABC (CSase). CS and L-homoarginine (hArg), an inhibitor of ALP, significantly suppressed mineralization in ATDC5 cells. In conclusion, supplemented CS directly inhibits ALP to prevent the progression of chondrocytes from differentiation to mineralization.

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.

An unusual case of common digital nerve compression caused by a lipoma arising from the flexor tenosynovium.

Lipoma of the hand is a common lesion, but lipoma arising from the flexor tenosynovium is a very rare tumor that induces peripheral nerve disorders. Only four cases of synovial lesions that comprised mature fat at the wrist and imitated carpal tunnel syndrome have been described in the literature. We herein report an unusual case of a lipoma arising from the flexor tenosynovium at the level of the ring finger just proximal to the A1 pulley that was responsible for a sensory disturbance of the ring and middle fingers secondary to compression of the common digital nerve at the palm. The patient was completely relieved of the symptoms after lipoma excision.