Published papers

A displaced surgical neck fracture can be a good indication for antegrade intramedullary nailing. However, nail insertion may result in malreduction and translational displacement of the humeral head fragment because of muscle traction and size discrepancies between the diameters of the medullary canal and the intramedullary nail. We used blocking screw augmentation in 20 fractures with residual medial displacement of the distal fragment after nail insertion to anatomically reduce displacement of the fracture and to maintain the reduced position before bone union. A blocking screw was placed percutaneously at the lateral side of the canal. Next, a straight intramedullary nail was reinserted medial to the blocking screw. Finally, the nail was locked both proximally and distally. All cases showed bone union without fixation failure at the time of the final follow-up. Blocking screw augmentation with intramedullary nailing is feasible for the treatment of humeral surgical neck fractures and is thought to be helpful for fracture reduction during surgery and stable fixation after surgery.

Case:A 60-year-old woman with avascular necrosis of the right humeral head underwent anatomical total shoulder arthroplasty (TSA); however, recurrent posterior dislocation occurred 13 months postoperatively. We performed bone block grafting of an autologous iliac crest to the posterior glenoid and posterior capsular plication, after which satisfactory postoperative shoulder function without residual joint instability was achieved.Conclusion:The presented case had recurrent posterior dislocation after TSA without any abnormal findings in the prosthetic components. Posterior bone block grafting with capsular plication should be considered a viable option for posterior instability after anatomical TSA.

This retrospective study evaluated procedural failures of closed reductions using an extension-block Kirschner wire (K-wire) for bony mallet finger. A total of 132 patients who underwent a closed reduction for bony mallet finger in a procedure using an extension-block K-wire were radiographically assessed. Radiographs were used to evaluate (1) postoperative displacement of the reduction before or after K-wire removal and (2) inaccurate reduction of the fragment immediately after surgery. The causes of procedural failure and bone union were evaluated using radiographs and medical records of the intraoperative findings. Out of 132 patients, 17 with procedural failure were enrolled. Displacement of the reduction before and after K-wire removal occurred in seven and six cases, respectively. Inaccurate reduction immediately after surgery occurred in four cases. The most common cause of procedural failure was inaccurate insertion of the K-wire to fix the distal interphalangeal joint (eight cases) followed by inaccurate insertion of the extension-block pin (five cases). All patients had bone union regardless of the displacement of the reduction or inaccurate reduction of the fragment. Caution should be exercised during the reduction and fixation when an extension-block K-wire is used in a closed reduction procedure.

Objective: Recent study suggests the distal radioulnar joint (DRUJ) plays a role in flexion and extension of the wrist. We examined the range of motion (ROM) of the wrist before and after DRUJ fixation and distal ulnar resection in a cadaveric model. Methods: Twenty fresh cadaveric human wrists were transected and treated with two sequential interventions: (a) DRUJ fixation, and (b) distal ulnar resection. The angle of maximum flexion and extension of the wrist was measured before and after the procedures. Maximum force to the wrist was determined before the procedures using a digital pressure monitor. Results: The mean maximum wrist flexion ROM was 84.2° before the procedures. The ROM decreased to 82.5° after DRUJ fixation, and significantly increased to 88.2° after subsequent resection of the distal ulna. The mean maximum wrist extension ROM before the procedures was 73.5°. The ROM decreased to 71.6° after DRUJ fixation, and significantly increased to 77.1° after subsequent resection of the distal ulna. Conclusions: Motion of the wrist is affected by DRUJ. This study suggests that the DRUJ might contribute to the ROM in flexion and extension of the wrist.

The aim of this retrospective study was to assess the effectiveness of autogenous bone grafting for arthrodesis of the thumb carpometacarpal joint by comparing the bone union rates with and without bone grafting. We included 36 patients who underwent arthrodesis of the thumb carpometacarpal joint for arthritis (20 patients with bone grafts and 16 without bone grafts). Implants used for internal fixation were K-wire, tension band wiring, headless compression screw and locking plate. The presence of bone union and the time from surgery to bone union were evaluated. The bone union rate was 20/20 (100%) in the bone grafting group and 12/16 (75%) in the non-bone grafting group (p = 0.03). There were no significant differences between the two groups in the time from surgery to bone union and patient characteristics. In conclusion, autogenous bone grafting may contribute to the bone union in the arthrodesis of thumb carpometacarpal arthritis. Level of evidence: III

OBJECTIVE: Environmental factors are involved in RA pathogenesis and epidemiological studies have suggested that smoking is an environmental risk factor for RA. The 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is one of the major toxic components in cigarettes. To clarify the biological effects of smoking in RA, we investigated the role of TCDD in RA pathogenesis. METHODS: Human synovial tissue was obtained from RA and OA patients and aryl hydrocarbon receptor (AhR) expression in these tissues was evaluated using immunohistochemistry and real-time PCR. Expression of various cytokines was measured by real-time PCR following stimulation of RA synoviocytes with different concentrations of TCDD. To study the role of AhR, we treated RA synoviocytes with alpha-naphthoflavone, a known AhR antagonist. To evaluate which signal transduction pathways were stimulated by the TCDD-AhR interaction, we used inhibitors of nuclear factor-kappaB (NF-kappaB) and extra-cellular stimulus-activated kinase (ERK). RESULTS: Higher AhR mRNA and protein levels were observed in RA synovial tissue than in OA tissue. TCDD up-regulated the expression of IL-1beta, IL-6 and IL-8 through binding to AhR, and this effect was transmitted via the NF-kappaB and ERK signalling cascades. AhR expression in synovial cells was up-regulated by TNF-alpha. CONCLUSION: TNF-alpha activates AhR expression in RA synovial tissue, and that cigarette smoking and exposure to TCDD enhances RA inflammatory processes. TCDD induces inflammatory cytokines via its association with AhR, resulting in stimulation of the NF-kappaB and ERK signalling cascades. Thus TCDD exposure, such as smoking exacerbates RA pathophysiology.

We studied the role of monocyte chemoattractant (MCP)-4/CCL13 in the pathogenesis of rheumatoid arthritis (RA). MCP-4 was highly expressed in cartilage from RA patients. Interferon-gamma significantly stimulated MCP-4/CCL13 production in human chondrocytes, and this effect was enhanced in combination with interleukin-1beta or tumor necrosis factor-alpha. MCP-4/CCL13 induces the phosphorylation of extracellular signal-regulated kinase in fibroblast-like synoviocytes and activates cell proliferation, and PD98059 completely inhibits these effects. These data suggest that interferon-gamma in combination with interleukin-1beta/tumor necrosis factor-alpha activates the production of MCP-4/CCL13 from chondrocytes in RA joints, and that secreted MCP-4/CCL13 enhances fibroblast-like synoviocyte proliferation by activating the extracellular signal-regulated kinase mitogen-activated protein kinase cascade.

A 59-year-old woman presented with dizziness and numbness of her left upper limb. Computed tomography (CT) angiography revealed an occlusion of the subclavian artery at its origin, leading to a diagnosis of subclavian steal syndrome. She was treated with percutaneous angioplasty and stenting; however, her symptoms did not improve. CT angiography of the arm in the elevated position revealed subclavian artery stenosis at the costoclavicular space, and the diagnosis was neurogenic thoracic outlet syndrome (TOS). First-rib resection was performed, and the symptoms disappeared immediately after surgery. TOS should be considered when symptoms persist despite subclavian steal syndrome treatment. Physical examination and CT imaging with the arm elevated aid in diagnosing TOS.

Intra-articular metacarpal head fracture is relatively rare. We report a case of coronal intra-articular and epiphyseal fractures of Salter-Harris type IV injury in the metacarpal head of the index finger. Surgery was performed by a dorsal approach. The volar fragment that was displaced proximally was gently reduced while bending the metacarpophalangeal (MP) joint, and it was fixed with cortical screws inserted proximal to the articular cartilage facilitating early rehabilitation. We consider the mechanism of injury to be a force applied from the distal phalanx that was transmitted unevenly to the volar side when the MP joint was slightly flexed. A three-dimensional computed tomography scan was useful in making the precise diagnosis, confirming the fracture pattern and planning fixation of the fracture.

We reported the case of a 65-year-old woman who presented with neuropathic arthropathy of the elbow and had undergone cervical spinal cord tumour resection at 32 years of age. Open synovectomy with free-body resection was performed; however, the instability of the elbow joint rapidly progressed. Therefore, we performed total elbow arthroplasty (TEA) using a linked-type prosthesis. However, the humeral stem became severely loosened 1 year after arthroplasty. Furthermore, a periprosthetic humeral fracture developed due to a minor trauma. A revision TEA using a long-stem prosthesis was performed 4 years after the primary TEA. Radiographs taken 2 years after the revision surgery showed no evidence of implant loosening. In this case, early postoperative loosening occurred despite the use of a linked-type prosthesis and an appropriate cementing technique, suggesting that normal implants may not provide sufficient fixation for neuropathic arthropathy of the elbow. Since surgery for neuropathic arthropathy generally has a poor prognosis, surgical interventions including TEA should be carefully considered.

Background: A novel biocompatible sealant composed of Alaska pollock- derived gelatin (ApGltn) has recently shown good burst strength and biocompatibility in a porcine aorta. The purpose of this study was to investigate the bonding strength and biocompatibility of the ApGltn sealant in transected digital nerves of fresh frozen cadavers and in the sciatic nerves of a rat model. Methods: Eighty human digital nerves of fresh frozen cadavers were transected for biomechanical traction testing. They were treated with four surgical interventions: (1) suture plus ApGltn sealant; (2) suture; (3) ApGltn sealant; and (4) fibrin sealant. Forty-three sciatic nerves of male Wistar rats were used for functional and histopathologic evaluation. They were treated with six surgical interventions: (1) suture plus ApGltn sealant; (2) suture; (3) ApGltn sealant; (4) fibrin sealant; (5) resection with a 5-mm gap (10 rats per group); and (6) sham operation (three rats). Macroscopic confirmation, muscle weight measurement, and histopathologic findings including G-ratio were examined 8 weeks after the procedure. Results: The maximum failure load of the ApGltn sealant was significantly higher than that of a fibrin sealant (0.22 ± 0.05 N versus 0.06 ± 0.04 N). The maximum failure load of the ApGltn sealant was significantly lower that of suture plus ApGltn sealant (1.37 N) and suture (1.27 N). Functional evaluation and histologic examination showed that sciatic nerves repaired with ApGltn sealant showed similar nerve recovery compared to repair with the suture and fibrin sealant. Conclusion: The ApGltn sealant showed higher bonding strength and equal effect of nerve regeneration when compared with the fibrin sealant.

Background: Accurate implant placement in the optimal position is important to obtain favourable clinical outcomes and prevent complications in total joint arthroplasty. We aimed to assess the accuracy of implant placement based on three-dimensional (3D) preoperative planning for unlinked total elbow arthroplasty (TEA) and to clarify the effect of implant placement on clinical outcomes. Methods: This study included 20 patients (22 elbows, 17 with rheumatoid arthritis and 5 with osteoarthritis, with a mean follow-up period of 47 months) who underwent TEA with an unlinked-Type implant after computed tomography (CT)-based 3D preoperative planning. Implant placement was planned preoperatively and several parameters were set to reflect it intraoperatively. TEA was performed based on the plan, and postoperative CT was conducted to evaluate differences in implant placement by comparing the preoperative plan and postoperative implant placement. Furthermore, we evaluated the relationship between implant placement differences and postoperative clinical outcomes, including range of motion, Visual Analogue Scale, Mayo Elbow Performance Score 1 year after surgery and complications at the last follow-up. Results: The mean absolute translation was within 2 mm, the mean absolute tilt was within 4°, the mean absolute rotation of the humeral component was within 4° and the mean absolute rotation of the ulnar component was 10.2° ± 6.8°. In the ulnar components, 15/22 (68%) cases were externally rotated, and the mean external rotation was 7.1° ± 10.2°. We defined the absolute ulnar component's rotational difference of more than 10° as a 'malrotation' group (n = 8) and 10° or less as a 'control' group (n = 14). We compared the clinical outcomes between both groups, however, no significant differences were observed in clinical outcomes and complications. Conclusions: We observed notable malrotation in the postoperative positioning of the ulnar component. Intraoperative support devices may be necessary to accurately reproduce the preoperative plan in the surgical field. Level of Evidence: Level IV (Therapeutic)

Study Design. Burst strength study in porcine dural models and functional and histological study in rat dural models. Objective. This study aimed to investigate the sealing strength and biocompatibility of Alaska pollock-derived gelatin (ApGltn) and fibrin sealants in disrupted dural injuries. Summary of Background Data. Disruption of the dura mater occurs during spine surgery, leading to cerebrospinal fluid leakage. Fibrin sealant is usually applied to ruptured sites; however, it lacks sealing strength. A novel biocompatible sealant composed of ApGltn was recently demonstrated to have good burst strength and biocompatibility in the porcine aorta. Methods. Ten porcine dura maters with central holes were covered with ApGltn and fibrin sealants (five samples per group). The maximum burst strength of each sealant was measured, and histological examination was performed after burst testing. Twenty-seven dura maters of male Wistar rats were used for functional and histopathological evaluations. The rats were treated with three surgical interventions: defect + ApGltn sealant; defect + fibrin sealant; defect alone (nine rats per group). Macroscopic confirmation of the sealant, hindlimb motor function analysis, and histopathological examination were performed at two, four, and eight weeks after the procedure. Results. The maximum burst strength of the ApGltn sealant was 4.4 times higher than that of the fibrin sealant (68.1±12.1 vs. 15.6±8.7 mmHg; P<0.001). Histological examination confirmed that the ApGltn sealant showed tight adhesion to the dural surface, whereas a gap was observed between the fibrin sealant and the dura mater. In the rat model, the ApGltn sealant resulted in spinal function and dural histological findings similar to those of the fibrin sealant. Conclusion. The ApGltn sealant had a higher sealing strength than, and comparable effect on dura regeneration with, the fibrin sealant.