Opponensplasty for Severe Carpal Tunnel Syndrome with the Transfer of the Palmaris Longus Tendon to the Rerouted Extensor Pollicis Brevis Tendon.

The authors describe a novel opponensplasty for severe carpal tunnel syndrome that uses the palmaris longus (PL) tendon transferred to the rerouted extensor pollicis brevis (EPB) tendon with pulley reconstruction using a portion of the PL tendon simultaneously with the carpal tunnel release. Like the Camitz opponensplasty, this technique utilises the PL as the motor source, does not require special postoperative treatment and enables fast functional recovery even in older patients. Compared with the Camitz procedure, this technique can easily acquire thumb rotation without tendon bowstringing. Furthermore, because the function of the EPB tendon is preserved, the tendency of flexion in the thumb metacarpophalangeal (MP) joint is not observed after surgery, and improvement can be expected in patients with preoperative MP joint extension lag. This technique is a useful alternative to the Camitz procedure, as it overcomes the disadvantages of the Camitz procedure while preserving the advantages. Level of Evidence: Level V (Therapeutic).

Vascularized Origami Medial Femoral Condyle Flap for Finger Joint Reconstruction.

SUMMARY: Total finger joint reconstruction is challenging. Vascularized toe joint transfer is currently used for reconstruction, but it is difficult to perform, fails to achieve maximal joint flexibility, and is associated with donor-site complications. As an alternative, the authors developed a vascularized medial femoral condyle flap technique, wherein the vascularized corticoperiosteum is shaped via origami, with the donor tissue folded to fit the recipient site. In this article, the authors describe the use of this method for reconstruction of interphalangeal and metacarpophalangeal joints with a reduced range of motion. The mean age of the patients (three men and four women) was 51 years (range, 36 to 68 years), and the mean follow-up period was 3 years 1 month (range, 4 months to 5 years). In the reconstructed joints, the mean range of motion; Disabilities of the Arm, Shoulder, and Hand score; and pinch strength of the unaffected side were 55 degrees (range, 24 to 90 degrees), 2.3 (range, 0 to 6), and 98% (range, 70% to 38%), respectively. No donor-site morbidities were observed. Radiography and computed tomography scans revealed joint-like grafted tissue remodeling. The study findings suggest that the origami medial femoral condyle flap is useful for functional finger joint reconstruction. The procedure requires fabrication before grafting, but tissue harvest is relatively easy.

A Comparison of the Outcomes of Fiber-Wire® versus Stainless Steel Wire in Transosseous Wiring for Intra-Articular Fractures of the Distal Interphalangeal Joint.

Background: Different surgical techniques have been described for the treatment of intra-articular fractures involving extensor tendon insertion of the distal interphalangeal joint (DIPJ), including acute and chronic bony mallet injuries. We have been using transosseous stainless-steel wire (SSW) in select patients. In 2015, we started using a non-absorbable polyester suture (2-0 Fiber-Wire®, Arthrex, Naples, FL, USA) instead of SSWs. The aim of this study is to compare the outcomes of SSW and Fiber-Wire® (FBW) in transosseous wiring for intra-articular fractures of the DIPJ. Methods: This is a retrospective review of patients who underwent fixation of intra-articular fractures, including extensor tendon insertion of the DIPJ using a transosseous wiring technique, in the period from 2013 to 2018. SSW was used in the period from 2013 to 2014, and FBW was used from 2015 to 2018. Outcomes with regard to age, gender, time to union, range of motion at the DIPJ and complications were recorded and compared between the SSW and FBW groups. Results: Nine patients (mean age: 38 years) underwent fixation with SSW and 10 patients (mean age: 31 years) with FBW. The operative time was significantly lower in the FBW group, and all the fractures united. There were no statistically significant differences between both groups with regard to time to union or range of motion at the DIPJ. Similar complication rates were observed in both groups. Conclusions: The use of FBW in transosseous wiring for intra-articular fractures of the DIPJ can reduce operative time and provide functional results similar to that of SSWs. It can be considered as an alternative fixation technique for difficult intra-articular comminuted fractures of the DIPJ, including acute and chronic bony mallet injuries with joint subluxation. Level of Evidence: Level III (Therapeutic).

Role of NADPH oxidase in tissue growth in a tissue engineering chamber in rats.

Previously we described a subcutaneous arteriovenous loop (AVL)-based tissue engineering chamber system, which contains an intrinsic circulation circuit created by joining the proximal ends of the femoral artery and vein with a venous graft. We showed that nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was involved in mediating neovascularization inside the chamber. However, the role of NADPH oxidase in tissue formation in the chamber is unknown. In this study, we examined the effects of gp91ds-tat, a peptidyl inhibitor of NADPH oxidase, on the growth of engineered tissue blocks, using a rat chamber model. Chambers containing the AVL were filled with Matrigel mixed with gp91ds-tat (100 microM) or the scrambled control peptide. At 14 days, in control chambers, most of the Matrigel was replaced by granulation tissues; gp91ds-tat treatment significantly reduced the level of reactive oxygen species and retarded the tissue formation process. Although the total number of blood vessels per unit cellularized area was not different between two groups, most vessels in gp91ds-tat-treated tissues had smaller lumens as compared to control. The total area occupied by vessel lumens was much less in gp91ds-tat-treated tissues (10.3 +/- 1.3% in control vs. 1.7 +/- 0.5% in gp91ds-tat group; p < 0.001). In vitro, gp91ds-tat treatment reduced proliferation and migration of cultured microvascular endothelial cells. Our data suggest that inhibition of NADPH oxidase function retards tissue formation in the tissue engineering chamber, which may be related to the malformed new blood vessels in the engineered tissue.

Arthroscopic autologous bone graft with arthroscopic Bankart repair for a large bony defect lesion caused by recurrent shoulder dislocation.

Many clinicians believe that a large bony defect of the glenoid must be treated with bone grafting when a Bankart procedure is performed. Various types of bone graft, such as open bone graft, Eden-Hybinnette, J-bone graft, coracoid transfer, and Latarjet, have been used. These require open procedures that are difficult to perform arthroscopically. We performed an arthroscopic autologous bone graft and an arthroscopic Bankart repair at the same time to treat a patient with recurrent dislocation of the shoulder joint and a large bony Bankart lesion. We harvested from the lateral site of the acromion 2 bones that were 2.7 mm in cylindrical diameter. We transplanted these bones to the large bony defect of the anteroinferior area of the glenoid and placed anchors between the 2 plugs. During the 30 months since the surgery was performed, the patient has not experienced dislocation or apprehension about the shoulder. A 3-dimensional computed tomography scan showed enlargement of the glenoid surface. Our surgical procedure offers promise for treatment of patients with recurrent dislocation of the shoulder joint and a large bony Bankart lesion because it allows the surgeon to alter the size and the grafted site of the cylindrical bone according to the size of the defect.

Flow cytometric discrimination of mesenchymal progenitor cells from bone marrow-adherent cell populations using CD34/44/45(-) and Sca-1(+) markers.

BACKGROUND: Cultured bone marrow adherent cells (BMACs) have been commonly used as stem cells in bone and cartilage regeneration therapy. However, BMACs are actually a heterogeneous cell population, and clinicians might have previously transplanted more fibroblasts or other cells than actual stem cells. The purposes of this study were to (1) isolate immature mesenchymal stem cells with CD34/44/45 and Sca-1 surface-antigen patterns from BMACs using flow-activated cell sorting and (2) investigate their differentiation potential. METHODS: Bone marrow cells were extracted from the mouse femur and cultured. Adherent cells could be identified approximately 3 days after seeding, and nonadherent cells were removed with the medium when it was changed. BMAC samples were cultured for 3, 7, 10, 14, 21, 28, 35, and 42 days after the first seeding. We directly isolated CD34/44/45(-)Sca-1(+) mesenchymal progenitor cells (MPC1) and CD34/45(-)/44(+) Sca-1(+) mesenchymal progenitor cells (MPC2) from BMACs based on their cell surface marker patterns using a fluorescence-activated cell sorter. These subgroups - MPC1, MPC2, and the residual cells in BMACs (non-MPC population: RCs) - were then induced to differentiate into bone, cartilage, and fat using a plate culture. The cultures were examined after histochemical staining on day 14. RESULTS: In a plate culture, the MPC1 population had higher potential to differentiate into osteoblasts, chondrocytes, and lipocytes; whereas MPC2 and RCs differentiated into only two lineages: osteoblasts and lipocytes. The incidence of these multipotential cells was less than 5% among the cultured BMACs. MPC1 proliferated up to 17-fold within 3-4 weeks after separation from floating cells and did not increase thereafter. CONCLUSIONS: BMACs are conventionally thought to differentiate into cartilage only in pellet culture, but we showed that MPC1 produced cartilage-like extracellular matrix in plate culture. MPC1, which are more immature cells than MPC2 and RCs, were multipotential progenitors that showed unique cartilage-differentiation potential. MPC1 had less ability to proliferate in BMAC culture, but they might have higher potential for chondrogenic differentiation.

The HU knot: a new sliding knot for arthroscopic surgery.

Sliding knots are commonly used in arthroscopic knot tying. The Surgical knot as a hand-tied knot is very secure. We found that the Surgical knot could be used as a sliding knot. We have modified the Surgical knot to include a self-locking loop. A new sliding knot for arthroscopic surgery, the HU knot, is described. By tensioning the loop strand, the self-locking loop creates a snug knot without sliding backward. The HU knot provides great security.

The cellular origin of cartilage-like tissue after periosteal transplantation of full-thickness articular cartilage defects: an experimental study using transgenic rats expressing green fluorescent protein.

BACKGROUND: Periosteal transplantation is commonly used for the treatment of articular cartilage defects. However, the cellular origin of the regenerated tissue after periosteal transplantation has not been well defined. The objective of this study was to investigate the cellular origin of the regenerated tissue after periosteal transplantation. METHOD: Free periosteum was harvested from the tibia of 10-week-old adolescent enhanced green fluorescent protein (GFP-) expressing transgenic Sprague Dawley (SD) rats and was transplanted to full-thickness articular cartilage defects of the patellar groove in normal 10-week-old adolescent SD rats. The periosteum was sutured to the defect with the cambium layer facing the joint cavity. 8 SD rats were killed at 4 weeks and 8 SD rats were killed at 8 weeks after surgery. The repaired tissue was assessed histologically and histochemically. GFP-positive cells derived from the donor periosteum could easily be detected in the repaired tissue by use of a fluorescent microscope. RESULTS: At both 4 and 8 weeks after transplantation, the entire area of the defects had been repaired, with the regenerated tissue being well stained histologically with safranin-O. Most cells in the whole area of the regenerated tissue were GFP-positive, indicating that very few of the cells were GFP-negative cells originating from the recipient rats. INTERPRETATION: This experiment demonstrates that most cells in regenerated tissue after periosteal transplantation using adolescent animals do not originate from recipient cells but from the periosteal cells of the donor.

Allogeneic bone marrow-derived mesenchymal stromal cells promote the regeneration of injured skeletal muscle without differentiation into myofibers.

Half-stratum laceration was performed on the tibialis anterior muscle of Sprague-Dawley (SD) rats as a skeletal muscle injury model. Bone marrow-derived mesenchymal stromal cells (BMMSCs), which were derived from enhanced green fluorescent protein (GFP) transgenic SD rats, were transplanted into the injured site. Tensile strength produced by nerve stimulation was measured for functional evaluation before sacrifice. Specimens of the tibialis anterior muscles were stained with hematoxylin and eosin, and immunohistochemically stained for histological evaluation. Our results showed that transplanted BMMSCs promoted maturation of myofibers histologically and made the injured muscle acquire almost normal muscle power functionally by 1 month after transplantation. However, the results of immunohistochemical staining could not prove that transplanted BMMSCs differentiated into or fused to skeletal myofibers, although it showed that transplanted BMMSCs seemed to differentiate into muscle precursor cells. Therefore, our results indicated that BMMSCs contributed to the regeneration of skeletal muscle by mechanisms other than fusion to myofibers after differentiation.

Acceleration of surgical angiogenesis in necrotic bone with a single injection of fibroblast growth factor-2 (FGF-2).

The aim of this study was to accelerate angiogenesis in necrotic bone by combining vascular bundle implantation and fibroblast growth factor-2 (FGF-2) administration. Twenty-four Japanese white rabbits were evaluated in this study. A portion of a rabbit iliac crest bone was removed as a free bone graft and frozen in liquid nitrogen to ensure complete cellular necrosis. A narrow hole was created in the bone and the graft was placed in the proximal thigh. In group 1, FGF-2 was injected into the hole at a single dose of 100 microg, and the saphenous artery and its venae comitantes were passed through the hole of the bone. In group 2, injection of saline into the hole and the vascular bundle implantation was used as a control. Neovascularization around the vessel was evaluated at weeks 1 and 2 after surgery. Neovascularization was observed along the implanted vascular bundle in both groups. At both 1 and 2 weeks after surgery, the vessel density of group 1 was significantly higher than that of group 2. The average length of newly formed vessels of group 1 was also significantly longer than that of group 2 at both 1 and 2 weeks after surgery. Both the vessel density and length were greater in week 2 animals than week 1. A local single injection of FGF-2 improved surgical angiogenesis in necrotic bone in this study. As FGF-2 is recognized as a potent mitogen for a variety of mesenchymal cells, the combination of vascular bundle implantation and FGF-2 administration may contribute to the treatment of ischemic osteonecrosis.