Biomedical subjects

Koji Shigematsu

Publications and source records attributed to Koji Shigematsu.

16 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

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

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

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

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

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↗

PubMed2004

Radial forearm flaps for reconstruction in hand surgery.

Thirty-seven patients were treated using distally-based island radial forearm flaps. There were 31 men and six women. Reconstructed sites involved the dorsum of the hand (n = 17), the thumb (n = 11), the fingers (n = 5), the first web (n = 3), and the palm (n = 1). Sensory flaps were transferred in 15 cases, osteocutaneous flaps in six, and tendocutaneous flaps in eight. All the flaps survived. There were five donor-site complications, but no functional disturbances. Three patients had symptoms of cold intolerance. There were no radial fractures. In the six cases with osteocutaneous flaps, a mean of 2.6 months (range 2-3) was needed to obtain bony union. Among the eight cases with tendocutaneous flaps, postoperative tenolysis was required in two cases, and finally seven achieved a satisfactory outcome. The mean moving 2-point discrimination of the sensory flaps was 13 mm.

Adult↗

PubMed2004

Radiocarpal arthrodesis for osteoarthritis following fractures of the distal radius.

To compare the radioscapholunate (RSL) arthrodesis and radiolunate (RL) arthrodesis as a treatment for radiocarpal osteoarthritis following fractures of the distal radius, nine patients, 23 to 70 years old (average 41) at the time of surgery, were assessed two to 33 years after surgery. The periods between injury and surgery ranged from four months to 30 years. RSL arthrodesis was performed in three cases and RL arthrodesis in six. Post-operative wrist pain disappeared in six and was decreased in the other three. In the RSL group, the total arc of wrist flexion and extension was reduced from 50 degrees pre-operatively to 35 degrees post-operatively. In the RL group, it was increased from 72 degrees to 76 degrees after surgery. Grip strength improved in most patients, from 7 to 18 kg in the RSL group, and from 16 to 27 kg in the RL group. On roentogenogram, three patients showed arthritic changes in the adjacent joints, but there were no symptoms in two of the three patients. We concluded that partial radiocarpal arthrodesis (preferably RL arthrodesis) is a reliable procedure for radiocarpal osteoarthritis following fractures of the distal radius.

Adult↗

PubMed2002

Reverse-flow island flap from the thenar area of the hand.

A reverse-flow island flap from the thenar eminence of the hand was applied in six patients to treat palmar skin defects, and amputation injuries of the thumb. There was one female and five males, and the patients' ages at the time of surgery averaged 48 years. A 3 x 2 to 5 x 3.5-cm fasciocutaneous flap from the radial aspect of the thenar eminence, located over the abductor pollicis brevis muscle, was designed and transferred in a retrograde fashion, to cover skin and soft-tissue defects of the thumb. The flap was based on the superficial palmar branch of the radial artery and, in three patients, was made sensate by the palmar branch of the superficial radial nerve. Follow-up periods averaged 61 months. The postoperative course was uneventful, and all the flaps survived without significant complications. The donor site was primarily closed in five patients, and one patient required flap coverage. A reverse island flap from the thenar area is easily elevated, contains durable fasciocutaneous structures, and has good color and texture, matching to the finger pulp. This flap offers a good alternative for reconstruction of palmar skin and soft-tissue defects of the thumb in selected patients.

Adult↗