Biomedical subjects

Hiroshi Yajima

Publications and source records attributed to Hiroshi Yajima.

At least 19 recordsLinked to original sources

PubMed2006

Oberlin partial ulnar nerve transfer for restoration in obstetric brachial plexus palsy of a newborn: case report.

An 8 month old male infant with Erb's birth palsy was treated with two peripheral nerve transfers. Except for rapid motor reinnervations, elbow flexion was obtained by an Oberlin's partial ulnar nerve transfer, while shoulder abduction was restored by an accessory-to-suprascapular nerve transfer. The initial contraction of the biceps muscle occurred two months after surgery. Forty months after surgery, elbow flexion reached M5 without functional loss of the ulnar nerve. This case demonstrates an excellent result of an Oberlin's nerve transfer for restoration of flexion of the elbow joint in Erb's birth palsy. However, at this time partial ulnar nerve transfer for Erb's birth palsy is an optional procedure; a larger number of cases will need to be studied for it to be widely accepted as a standard procedure for Erb's palsy at birth.

Case Reports↗

PubMed2006

Experimental study of vascularized tissue-engineered bone grafts.

BACKGROUND: Vascularized bone grafting has become a useful method for treatment of large bone defects and infected nonunions that lack adequate blood supply. This method has disadvantages, however, such as donor-site complications. To overcome these disadvantages, the authors developed a new method for creating vascularized tissue-engineered bone grafts in an experimental model. METHODS: Fisher rat bone marrow mesenchymal stem cells were cultured for 2 weeks in fully opened, interconnected, porous hydroxyapatite ceramic. The composites of mesenchymal stem cells and hydroxyapatite were implanted in the medial calf region together with the saphenous vascular bundle in syngeneic rats. Two weeks after implantation, the vascular pedicle with the implants was exposed and covered with silicone rubber to prevent vascular invasion through surrounding tissues (vascularized mesenchymal stem cell/hydroxyapatite implants). In addition, nonvascularized mesenchymal stem cell/hydroxyapatite implants were created with a ligated vascular pedicle. Implants of vascularized hydroxyapatite alone were prepared as a control. All implants were retrieved 4 weeks after surgery. RESULTS: Histologically, de novo bone formations were observed in the vascularized implants. This was in contrast with only necrotic tissue observed in the nonvascularized implants. Bone formation was not observed entirely in the vascularized hydroxyapatite-alone implants. For biochemical analysis, alkaline phosphatase activity and osteocalcin content of the vascularized mesenchymal stem cell/hydroxyapatite implants were significantly higher than those of the nonvascularized mesenchymal stem cell/hydroxyapatite and vascularized hydroxyapatite-alone implants. CONCLUSION: The results of this study indicated that the vascularized tissue-engineered bone grafts could be transferred as free vascularized grafts to lesions that lack adequate blood supply.

Alkaline Phosphatase↗

PubMed2006

Treatment of Kienböck's disease with cultured stem cell-seeded hybrid tendon roll interposition arthroplasty: experimental study.

BACKGROUND: Several procedures that consist of excision arthroplasty, intercarpal arthrodesis with or without excision of the lunate, proximal row carpectomy, and joint leveling procedures are used to treat advanced Kienböck's disease. However, no reconstructive surgery for a collapsed lunate has been established. The aim of this study was to develop a method of tendon roll interposition arthroplasty using a tissue-engineering technique to improve the clinical results of the tendon roll interposition arthroplasty for treating advanced Kienböck's disease. METHODS: Twenty-four Japanese white rabbits were used for this study as three treatment models of Kienböck's disease. The lunate of the right paw was excised, and then one of three kinds of tendon roll was interposed into the excision space as follows: group A (controls), a conventional tendon roll made of autologous Achilles tendon; group B (cored tendon roll) a tendon roll with a core of the collagen-ceramic composite; and group C (hybrid tendon roll), a scaffold seeded with cultured cells was rolled in the Achilles tendon. In all groups the right wrist was immobilized with cast 6 weeks after surgery. Wrist radiography was evaluated 0, 4, 6, and 12 weeks after surgery; specimens were sectioned and evaluated histologically 12 weeks after surgery. RESULTS: In group C the small shadow of the hydroxyapatite granule gradually increased until 12 weeks after surgery, whereas in group B the shadow of the core gradually decreased. The deficit spaces of the lunate remained radiographically lucent for 12 weeks after surgery in group A. Histological findings revealed new bone formation at the center and stained cartilage matrix at the peripheral of the hybrid tendon roll group (group C) but not in group A or B. CONCLUSIONS: Radiological and histological examinations proved that it is possible to make new hybrid tendon rolls using this method, as osteogenesis in the center and cartilage matrix in the peripheral of the tendon roll were revealed.

Animals↗

PubMed2006

Giant-cell tumors of the carpus.

Giant cell tumor (GCT) of bone is a rare, benign tumor with some aggressive characteristics such as a high recurrence rate. The tumor usually occurs in the distal radius although it has been reported in the carpus. We reviewed 63 manuscripts published from 1935 to 2005 and report on the treatment of GCT of carpal bone in 29 cases. Intralesional procedures, such as curettage, were associated with a high incidence of recurrence (24%), whereas cases treated with an excisional procedure did not recur.

Amputation, Surgical↗

PubMed2006

Post-traumatic big toe reconstruction using free flaps.

The big toe is of great importance for good stability and gait, but few reports have documented reconstruction of big toe defects. In this study, seven male patients, aged 17 to 59 years at surgery (average: 35 years), were treated for big toe defects. The metatarsophalangeal (MTP) joints of the big toe were intact in all patients. Five patients were treated with free peroneal flaps (including one perforator flap), and two with free scapular flaps; flap sizes ranged from 9 x 4 to 24 x 6 cm. Follow-up periods ranged from 10 to 29 months, (average: 16.6 months). The iliac was used as the grafted bone in four patients and the scapula in one. Six flaps survived completely, and bone unions were achieved within 3 months. One flap became partially necrotic due to arterial thrombosis. All patients returned to their original jobs, and the cosmetic appearances of all toes were acceptable.

Adolescent↗

PubMed2006

Free and island flap transfers for the treatment of motor vehicle injuries.

Thirteen patients (10 males and 3 females; age range at surgery: 2 to 41 years, average: 13.5 years) with motor vehicle injuries of the foot (n = 10) and leg (n = 3) were treated using free and island flaps. Donor flaps consisted of a scapular flap in six cases, a peroneal flap in four, a latissimus dorsi musculocutaneous flap in one, gracillis muscle flap in one, and gastrocnemius muscle flap in one case. Free grafts were transferred in 10 patients and pedicle grafts in three. All flaps survived completely. Moderate scarring was noted in two patients who underwent scapular flap transfer, and growth disturbances occurred in two patients with metatarsal fracture accompanying epiphyseal plate injury. Functionally, no patients experienced any disturbance, and all reconstructed sites were cosmetically satisfactory. Early flap coverage of soft-tissue defects due to motor vehicle injury was shown to be useful from the point of view of both cosmetic and functional results.

Accidents, Traffic↗

PubMed2006

Tissue-engineered approach for the treatment of steroid-induced osteonecrosis of the femoral head: transplantation of autologous mesenchymal stem cells cultured with beta-tricalcium phosphate ceramics and free vascularized fibula.

Autologous mesenchymal stem cells (MSCs) cultured with beta-tricalcium phosphate (beta-TCP) ceramics and with a free vascularized fibula were transplanted into three patients with steroid-induced osteonecrosis of the femoral head. The average follow-up period was 34 months and the average patient age at the time of surgery was 28 years old. Fifteen milliliters of bone marrow was obtained from the patients 4 weeks before surgery, and was used for in vitro proliferation of MSCs. beta-TCP granules were immersed in the MSC suspension and the cells were further cultured for 2 weeks. Cultured MSCs/beta-TCP composite granules were implanted into the cavity that remained after curettage of necrotic bone; and finally, a free vascularized fibula was grafted. All hips showed preoperative collapse and radiographic progression was observed in two hips postoperatively. Osteonecrosis did not progress any further and early bone regeneration was observed. This tissue-engineered approach has potentials for the treatment of osteonecrosis. However, our results suggested that the present procedure could not be used for cases with severe preoperative collapse.

Adult↗

PubMed2005

Anatomy of Y-shaped configurations in the subscapular arterial system and clinical application to harvesting flow-through flaps.

BACKGROUND: A flow-through flap is useful in cases where the recipient artery must not be sacrificed. The aim of this study was to investigate Y-shaped configurations in the subscapular arterial system that can safely be used in harvesting a flow-through flap from the scapular region. METHODS: Sixteen dissections of the subscapular arterial system were carried out in eight embalmed cadavers. The origins and external diameters of branches in the subscapular arterial system were recorded. The distances between the origins of each branch were measured. RESULTS: The branches that showed a consistent presence and had a reliable diameter of more than 1.0 mm were the circumflex scapular artery, the bony branch of the circumflex scapular artery, the thoracodorsal artery, the angular branch, and branches to the serratus anterior and latissimus dorsi muscles. It was demonstrated that using the Y-shaped configuration between these branches enables the harvesting of a flow-through flap in various length versions of the Y-shaped vascular pedicles. A significant anatomical variation (i.e., both the thoracodorsal and circumflex scapular artery arose directly from the axillary artery) was found in three of 16 dissections. In this vascular variation, sacrificing the axillary artery must be avoided, so Y-shaped pedicles using the origin of the thoracodorsal or circumflex scapular artery cannot be created. On the basis of these results, flow-through flaps using this arterial system were applied in 10 patients for reconstruction of lower extremities, and satisfactory results were obtained. CONCLUSIONS: The results of our study are available for determining preoperatively and intraoperatively which Y-shaped configuration to use in harvesting a flow-through flap from the scapular region.

Adolescent↗

PubMed2005

Seventeen-year follow-up of a reattachment of a nonunited anterior tibial spine avulsion fracture.

Seventeen years ago we treated a nonunited avulsion fracture of the anterior tibial spine with open reduction and pull-out wires. When the patient was 9 years old, she fell and bruised her left knee. The knee was immobilized for a month in a long cast. When she was 24 years old, she felt severe knee pain and giving way after playing tennis 1 month before her first visit to our hospital. She complained of knee pain, giving way, locking, and 15 degrees loss of knee extension. Radiographs showed a large nonunited fragment at the intercondylar eminence of the tibia. She underwent a reattachment surgery. When she was re-evaluated 17 years after surgery, she had no pain, no giving way, no locking, and no loss of knee extension. On physical examination, there was no instability. Plain anteroposterior and lateral radiographs showed a well-united fragment of the anterior tibial spine. In conclusion, the open reduction for knee pain, giving way, locking, and loss of knee extension caused by nonunion of avulsion of the anterior tibial spine yielded satisfactory results. We believe that in cases of nonunited anterior tibial spine fractures it is necessary to attempt to secure the anterior cruciate ligament in an anatomic position.

Anterior Cruciate Ligament Injuries↗

PubMed2005

Coverage of big toe defects after wrap-around flap transfer with a free soleus perforator flap.

In thumb reconstruction, a wrap-around flap transfer from the big toe gives excellent results aesthetically and functionally; however, there may be some problems at the donor site, such as delayed wound healing and skin ulceration. In 10 patients, a free soleus perforator flap was used for immediate coverage of defects of the big toe with wrap-around flap procedures. Eight flaps survived completely, and the time required for wound healing was less than 1 month. Two flaps developed partial necrosis and required additional skin grafts. The average follow-up period was 46 months. There were no patients requiring defatting of the flaps. There were no patient complaints, such as postoperative skin erosion or ulceration. All patients were satisfied with the outcome. A free soleus perforator flap is an available method for covering defects of the big toe after wrap-around flap transfer.

Adolescent↗

PubMed2005

Plexiform schwannoma of the ulnar nerve.

Plexiform schwannoma is a rare benign neurogenic tumour; we report a case that arose in the ulnar nerve of a 59-year-old woman. Exploration showed a continuous multinodular tumour that involved the ulnar nerve from the hand to the upper arm; the length of the tumour was 35 cm.

Biopsy, Needle↗

PubMed2005

Treatment of Kienböck disease in an 11-year-old girl with temporary fixation of the scaphotrapeziotrapezoidal joint.

An 11-year-old girl with Kienböck disease (stage IIIA) was treated by temporary scaphotrapeziotrapezoidal fixation. It was fixed in a cast for four weeks and wires removed after eight weeks. Follow up examinations showed that movement of the wrist and grip strength were improved, and she had no pain while revascularisation of the lunate could be seen on magnetic resonance imaging.

Arthrodesis↗

PubMed2005

Pisiform and hamate coalition: case report and review of literature.

Pisiform and hamate coalition is a rare anomaly of the carpal bones; a symptomatic case is an especially rare condition. We report a case of symptomatic pisiform and hamate coalition in a 15-year-old Japanese male. The literature of pisiform and hamate coalition is reviewed.

Accidental Falls↗

PubMed2005

Extensor pollicis longus tendon rupture as a result of scapholunate dissociation: a case report.

A 39-year-old patient was presented with, to our knowledge, the first ever diagnosed case of extensor pollicis longus (EPL) tendon rupture as a result of scapholunate (S-L) dissociation. Arthroscopic findings showed that the dorsal aspect of the S-L ligament was ruptured and severe synovitis was revealed around the S-L joint. Direct observation revealed synovium at the rupture site of the EPL tendon. After careful resection of this synovium, an aperture in the S-L joint was observed. Thus, it was considered that the synovium in the S-L joint was connected to the rupture site of the EPL tendon, passing through the dorsal capsule of the S-L joint. The ruptured EPL tendon was reconstructed with extensor indicis proprius tendon transfer, and S-L dissociation was treated with a bone-retinaculum-bone autograft taken from the third dorsal compartment region.

Adult↗

PubMed2005

Clinical applications of free soleus and peroneal perforator flaps.

Clinical applications of two free lateral leg perforator flaps are described: a free soleus perforator flap that is based on the musculocutaneous perforator vessels from one of the three main arteries in the proximal lateral lower leg, and a free peroneal perforator flap that is based on the septocutaneous or direct skin perforator vessels from the peroneal artery in the distal and middle thirds of the lateral lower leg. The authors applied free soleus perforator flaps to 18 patients and free peroneal perforator flaps to five patients with soft-tissue defects. The recipient site was the great toe in 14 patients, the hand and fingers in five patients, the leg in two patients, and the upper arm and the jaw in one patient each. The largest soleus perforator flap was 15 x 9 cm, and the largest peroneal perforator flap was 9 x 4 cm. Vascular pedicle lengths ranged from 6.5 to 10 cm in soleus perforator flaps and from 4 to 6 cm in peroneal perforator flaps. All flaps, except for the flap in one patient in the peroneal perforator flap series, survived completely. Advantages of these flaps are that there is no need to sacrifice any main artery in the lower leg, and there is minimal morbidity at the donor site. For patients with a small to medium soft-tissue defect, these free perforator flaps are useful.

Accidents, Occupational↗

PubMed2004

Long-lived retrograde fluorescent labeling of corticospinal neurons in the living animal.

For pathophysiological studies, it is advantageous to label specific neuronal populations in living animals. This study aimed to establish a method for stable and long-lasting fluorescent labeling of corticospinal neurons in the living animal. The two fluorescent dyes Fluoro-Red and Fluoro-Green were injected in the cervical spinal cord of anesthetized newborn rats. After a recovery period, treated rats were returned to the mother. After 24 h and 14 days, fixed brain sections revealed wide-spread fluorescence in elongated or pyramidal-shaped cell profiles in a discrete internal cortical layer, consistent with layer V pyramidal cells. Labeled neurons displayed spontaneous synaptic activity using the slice patch clamp method. These results suggest that these dyes are effective tools for pathophysiological and slice patch clamp studies focused on specific neuron groups.

Action Potentials↗

PubMed2004

Vascularized fibular grafting in the treatment of methicillin-resistant Staphylococcus aureus osteomyelitis and infected nonunion.

Twenty patients with methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis and bone infection were treated with vascularized fibular grafts. There were 16 males and four females, and the patient ages at operation ranged from 17 to 73 years. Nine of the lesions affected the femur, eight the tibia, and there were three others. All of the patients were treated with extensive debridement of the lesions and local antibiotic therapy. Continuous local irrigation was applied in two patients, antibiotic-formulated bone cement in five, and both in 10 patients. Recurrence of local infection occurred in six patients, including one failed graft. Eventually, 18 of the 20 cases attained successful subsidence of the inflammation. The mean period required to obtain radiographic bone union was 7 months in the femoral reconstruction group, 6.1 months in the tibial reconstruction group, and 6 months in the remaining patients. The authors believe that vascularized fibular grafting is the most reliable procedure for the treatment of MRSA osteomyelitis and infected nonunion.

Adolescent↗

PubMed2004

Dysvascular lower extremity reconstruction using free flaps with a "Y" configuration of the arterial pedicle.

For patients with a dysvascular lower extremity, free flaps have been transferred by end-to-side anastomosis, in order to maintain peripheral circulation. For such patients, the authors have applied free flap transfers with a "Y" configuration of the arterial pedicle. Eight free flaps with a Y configuration of the arterial pedicle were used in seven patients: latissimus dorsi musculocutaneous flaps in six, and scapular flaps in two. For the former, flaps were harvested with the subscapular and circumflex scapular arteries forming a Y pedicle in three cases, and with the thoracodorsal artery and the branch of the serratus anterior muscle in three. For the scapular flap transfers, the flap was harvested with the subscapular and thoracodorsal arteries forming a Y pedicle in one case, and with the circumflex scapular artery and the descending branch in the other. This procedure was performed for single-artery extremities in two cases. One developed arterial thrombosis of the branch to the foot, but removal of the thrombus and reanastomosis resulted in peripheral blood circulation being maintained. Eventually, all flaps survived. This procedure is indicated in patients with lower-leg reconstruction, especially with vascular disease.

Adult↗