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Biomedical subjects

Kazuteru Doi

Publications and source records attributed to Kazuteru Doi.

At least 19 recordsLinked to original sources
PubMed2007

The use of free vascularized corticoperiosteal grafts from the femur in the treatment of scaphoid non-union.

Most scaphoid non-unions can be treated successfully with conventional bone graft and screw fixation. Only a few cases with established avascular necrosis of the proximal fragment and previous failed conventional bone grafting should undergo vascularized bone graft. Cases in which the fragments are too small to accommodate a vascularized bone graft are better treated by alternative procedures. This article describes the role of vascularized bone grafting for scaphoid non-union, indications, donor bone selection, the authors' operative technique for vascularized bone graft from the supracondylar region of the femur, outcomes, and complications.

Bone Transplantation↗
PubMed2006

In vivo three-dimensional motion analysis of the forearm with radioulnar synostosis treated by the Kanaya procedure.

Attempts to separate congenital radioulnar synostosis and restore forearm rotation had been disappointing until a new mobilization technique was developed by Kanaya and colleagues using free vascularized fascio-fat graft interposition. This technique provides a functional rotation arc, but postoperative forearm motion is difficult to evaluate given the inaccuracies in determining the range of motion and rotational axis using conventional x-rays or computed tomography. This study represents an attempt to analyze in vivo three-dimensional motion of the forearm with radioulnar synostosis treated by Kanaya's operation using a markerless bone registration technique. Six patients with seven postoperative forearms (six with congenital and one with posttraumatic radioulnar synostosis) underwent 3D computed tomography with the forearm in neutral, fully pronated, and fully supinated positions. Range of motion according to this method was 30 +/- 18 degrees, significantly smaller than the 82 +/- 29 degrees from manual examination. Improvements in range of motion were significantly greater in cases without dislocation of the radial head (46 +/- 13 degrees) than in cases with dislocation (19 +/- 10 degrees). Dislocation of the radial head was also significantly correlated with an abnormal axis of rotation of the forearm.

Adipose Tissue↗
PubMed2006

Vascularized ulnar nerve graft.

The purpose of this article is to describe the indications, anatomy, and harvesting technique of vascularized ulnar nerve graft based on the superior ulnar collateral artery (SUCA) for reconstruction of upper extremity function. The ulnar nerve has an extrinsic blood supply consisting of multiple dominant systems: the SUCA, the inferior ulnar collateral artery, the posterior ulnar recurrent artery, and the ulnar artery. The entire length of the ulnar nerve can survive based on the SUCA and its venae comitantes. The vascularized ulnar nerve graft is used when there is a hopeless prognosis for ulnar nerve repair. This technique may be selected if there is a definite evidence of preganglionic injuries of the C8 and T1 roots in brachial plexus injuries. This technique can be recommended for reconstruction of a large defect of the median or radial nerves in selected cases, such as upper arm replantation.

Accidents, Traffic↗
PubMed2006

Technique of harvesting the gracilis for free functioning muscle transplantation.

In this article, we describe our technique and experience in harvesting the gracilis muscle for free functioning muscle transplantation (FFMT). The gracilis is the most commonly used muscle for FFMT. The main indication for gracilis FFMT is traumatic brachial plexus injury. Gracilis muscle has a class 2 vascular pedicle, with a dominant vascular pedicle originating from the profunda femoris vessels and a single motor nerve originating from the obturator nerve. During gracilis harvest, it is important to include the entire fascia around the muscle to ensure vascularity of the skin paddle and enhance muscle gliding in its new bed. Mobilization of the adductor longus allows tracing of the pedicle to its origin from the profunda femoris vessels, hence, achieving the maximum available length of the pedicle. Lengthening of gracilis tendon with a periosteal strip provides a free gracilis long enough to span the distance from the clavicle to the distal forearm. The main complications are related to the wound, and these include delayed healing, infection, and scar-related problems. The functional deficit after gracilis harvest is negligible.

Dissection↗
PubMed2005

Free vascularized fibula grafting for reconstruction of the wrist following wide tumor excision.

Free vascularized fibula transfer is an established method for reconstruction of the wrist following tumor resection. In cases of resection of the radial articular surface, three reconstructive options are possible: fibular head transfer along with the shaft to replace the radial joint surface, fixation of the fibula to the scaphoid and lunate, or a complete wrist fusion. Three patients with a tumor involving the distal end of the radius were treated with wide resection, and subsequent wrist reconstruction was performed, using the above-mentioned procedures. Although our experience included only a small number of patients, both radio-carpal hemiarthroplasty and fibulo-scapho-lunate fusion similarly provided successful wrist stability and functional range of motion in these cases. Even when the wrist was totally fused with the fibula, its function was still acceptable.

Adolescent↗
PubMed2005

An experimental model of peripheral nerve adhesion in rabbits.

We studied the effects of peripheral nerve adhesion in a rabbit sciatic nerve model. After nerve exposure, its adventitial layer was sutured with 8-0 nylon to the nerve bed, which had been cauterised to promote adhesion. Nerve kinematics, electrophysiology, blood flow and histology were assessed. Rabbits in which Fontana's bands were visible as normal through the epineurium, classified as a nonadhesion group (group I), lacked intraneural fibrosis. In this group, nerve conduction and nerve blood flow were well maintained. Rabbits in which Fontana's bands could not be seen were classified as the adhesion group (group II). This group was classified into two levels pathologically; thickening of epineurium and perineurium was observed but no endoneurial fibrosis (group IIa), and endoneurial fibrosis (Wallerian degeneration, myelin sheath thinning and fibrosis between nerve fibers) was noted (group IIb). Compound muscle action potentials (CMAP) were reduced in amplitude and blood flow was significantly decreased at adhesion sites in group IIb. In conclusion, adhesion of peripheral nerve to surrounding tissues results in fibrosis in the nerve that contributes to peripheral nerve dysfunction.

Action Potentials↗
PubMed2005

Restoration of prehension using double free muscle technique after complete avulsion of brachial plexus in children: a report of three cases.

PURPOSE: Brachial plexus injury in children, excluding birth palsy, is relatively rare and seldom reported. We report our technique, the results of this procedure, and problems we encountered in treating children with brachial plexus injury. METHODS: From 1999 through 2002, we treated 3 children with complete avulsion of the brachial plexus due to trauma by using double free muscle technique (DFMT) with a nerve transfer procedure using the contralateral seventh cervical nerve root transfer to reconstruct prehensile function. There were 2 boys aged 5 and 11 years and a girl aged 4 years. All patients were followed up for at least 3 years after the surgery. RESULTS: All the transferred muscles survived without any vascular complications and were reinnervated successfully. The average active range of elbow flexion was 125 degrees (range, 90 degrees - 145 degrees ). The average total active range of motion of the fingers was 69 degrees (range, 40 degrees -102 degrees ). All patients obtained voluntary prehensile function and could use the reconstructed hand for activities of daily living. They were able to lift and carry light objects with the reconstructed hand and heavy objects with both hands. CONCLUSIONS: The results of DFMT for reconstruction of BPI in children were encouraging. Appropriate postoperative rehabilitation under close supervision is important to obtain useful prehensile function.

Accessory Nerve↗
PubMed2005

Cell traffic between donor and recipient following rat limb allograft.

Although cell traffic from the graft into the recipient and from the recipient into the graft had been noticed in allogeneic organ transplantation, little is known following whole-limb allografting. This study was conducted to define cell migration between donor and recipient. Sixty-seven vascularized hind limb allotransplantations were performed in rat sex-mismatched pairs and the recipient animals were treated with FK506 immunosuppression. The ratio of donor and recipient cells was evaluated by semi-quantitative PCR using the specific primers of the Y-chromosome. Allografted limbs had no rejection episode until the final assessment. The male recipient cells were detected in female limb grafts not at 1 week but at 48 weeks after transplantation. The male donor cells were detected in the humerus and tibia in the female recipient but not in the gastrocnemius muscle and leg skin. Our results demonstrated that recipient-derived cells gradually migrated into the grafted bone, muscle and skin cells with the duration of time. Donor-derived cells migrated into the healthy bones but not into the healthy muscle and skin. Because active regeneration occurs in the grafted limb to compensate graft damage secondary to ischemia and operative intervention, recipient-derived cells may mediate a muscular and dermo-epidermal renewal.

Animals↗
PubMed2005

Arthroscopically assisted reduction and immobilization of intraarticular fracture of the distal end of the radius: several options of reduction and immobilization.

On the basis of preoperative computerized tomography scanning and newly developed 3-dimensional reconstruction technique, Doi classified intraarticular distal radial fracture to 2-, 3-, and 4-part type, according to the number of main fracture fragments in distal radial aspect. This classification system simply, as well as perspicuously, describes the status of joint surface, thereby providing an intuitionist and practical guideline for arthroscopy procedure. Between 1992 and 2003, 91 patients ranged from 21 to 79 years of age with intraarticular distal radius fracture were treated with an arthroscopically assisted operation at our department. Among these patients, 42, 34, and 15 cases were 2-, 3-, and 4-part type, accounting for 46%, 37%, and 17% respectively. Wrist arthroscopy was applied individually according to the different type, with the purpose of achieving <1mm reduction. Role of arthroscopy was postreduction examination for 14 cases, as K-wire guider in 13 cases, assisting reduction, and immobilization in 61 cases. Four of the 61 cases changed to ORIF. Immobilization methods include external fixator combined with K-wire or plate combined with pullout wire or screw. K-wire without other implant was applied to 6 cases. In 1 case, a screw was the only implant.

Arthroscopy↗
PubMed2005

Proposal of new category for congenital unilateral upper limb muscular hypertrophy.

According to congenital anomalies of the hand and forearm classifications, the common characteristic of overgrowth problems is the skeletal overgrowth of part or all of the hand. Congenital unilateral muscular hypertrophy of the upper extremity has been classified under the overgrowth (gigantism) problems as whole-limb hemihypertrophy. The common characteristic of overgrowth problems is the skeletal overgrowth of part or all of the hand, which is not prominent in these patients. Only 15 cases with this anomaly have been reported since 1962. These patients have abnormal muscles with hypertrophic appearance and changed tendon to muscle length ratio. This type of muscular hypertrophy shows an increase in the number of fibers in transverse section, as also seen in multiply innervated muscles like the sartorius and gracilis in humans. Although this phenomenon has a mosaic type distribution, there is no progression of the muscular hypertrophy during growth period. Hand deformities are not due to a part of progression of the disease but result of imbalance of the extrinsic and intrinsic muscles. The evolutionary changes of skeletal muscles should be investigated to explain this congenital phenomenon and might be classified in a different entity from the present categories.

Child, Preschool↗
PubMed2005

Selection of grip function in double free gracilis transfer procedures after complete paralysis of the brachial plexus.

Double free gracilis transfer (DFGT) procedures introduced by Doi et al have resulted in significant improvement in maintaining functional prehensile hand after total brachial plexus injury (TBPI). However, not all patients with satisfactory recovery of finger motion could improve their prehensile function. The use of reconstructed hand in daily activities was examined retrospectively to plan individual grip function, depending on the patient's own demand. Thirty patients who had had reconstruction with DFGT procedures were evaluated retrospectively according to total active motion (TAM), power grip, hook grip, and pinch function. Power grip was evaluated by holding a bottle and hook grip by lifting a weight. Only 11 patients (36%) had very light pulp-to-pulp pinch, 11 (36%) had power grip, and 25 (83%) had hook grip. The mean weight that could be carried by hook grip was 1.3 kg. The mean TAM was 43 degrees. Pain sensation was the only encouraging sensation recovery, radiating to the chest. Fine movements of the hand like pinching require well-developed exquisite control of movements. TBPI patients have the contralateral normal limb, which they always prefer, only using their reconstructed hand when the activity requires both hands, such as when holding a bottle to open its cap or lifting bags when the contralateral normal hand is already engaged. For performance of these actions, hook grip and power grip are the useful prehensile hand functions that can be obtained after DFGT. Selection of grip functions should be done according to patient needs, and the late-stage reconstructive hand operations should be decided according to preferred grip function.

Adolescent↗
PubMed2005

Double-strand suturing fixation technique for treatment of acute volar plate avulsion fracture of the base of the middle phalanx.

A new suturing technique for treatment of acute volar plate avulsion fracture of the proximal interphalangeal joint is reported. Because this technique that consists of double-strand suture is rigid enough and never obstructs joint motion, early motion exercise can be allowed. This technique only demands simple skill like conventional K-wire fixation. Furthermore, removal of fixation material is not necessary.

Acute Disease↗
PubMed2004

Free vascularized joint transfer from the nonreplantable digit as a free flap for primary reconstruction of complex hand injury.

We report our experience in treating a a patient with an electrical saw injury to the right hand that resulted in incomplete amputation of the ring and small fingers at the metacarpophalangeal (MCP) joint with segmental tissue loss. Ray amputation of the small finger was performed because of extensive tissue loss. The proximal interphalangeal joint of the nonreplantable small finger was transferred as a fillet flap for primary reconstruction of the severely damaged MCP joint of the ring finger after revascularization. Two years after surgery active range of motion of the reconstructed MCP joint was 35 degrees extension to 85 degrees flexion with no instability or pain.

Accidents, Occupational↗
PubMed2004

Obturator nerve injury associated with femur fracture fixation detected during gracilis muscle harvesting for functioning free muscle transfer.

A rare case is reported in which injury of the motor nerve of the gracilis (obturator nerve) was detected during its harvesting for functioning free muscle transfer. The probable cause of this rare injury was considered to be accidental penetration while drilling for a proximal locking screw in intramedullary nailing during previous femur fracture surgery.

Adult↗
PubMed2004

Radioisotope technique to evaluate the motor functional status of donor nerve for upper extremity reconstruction.

A rapid and precise method of nerve fascicle identification based on measurement of choline acetyltransferase activity using radioisotope technique was used intraoperatively during upper extremity reconstruction. This technique can be used to evaluate the motor function of donor fascicles directly and quantitatively. This technique is useful to evaluate the motor functional status of donor fascicles during functioning free muscle transfer, to distinguish between preganglionic and postganglionic injuries in brachial plexus injury, and to differentiate between motor and sensory fascicles during nerve grafting procedures.

Journal Article↗
PubMed2004

Vascular malformation of hand: cavernous lymphangioma.

A case of congenital cavernous lymphangioma of the hand presenting in a newborn is presented. The mass on the dorsum of the hand was removed with the overlying skin and underlying paratenon at three years of age. Re-surfacing was performed with a free flap transfer. There were no post-operative complications during one year of follow-up.

Hand↗
PubMed2003

Ulnar variance and the role of joint levelling procedure for Kienböck's disease.

Forty patients with Kienböck's disease were reviewed to determine the relationship between ulnar variance and the development of Kienböck's disease in a Japanese cohort. The joint levelling procedures designed to correct ulnar variance were evaluated in 11 patients after a mean of 9.7 years following surgery. The mean ulnar variance was 0.50+/-1.67 in patients with Kienböck's disease and 0.56+/-1.76 in a control group. The onset of wrist symptoms in a younger age group was noticed after sports injuries, whereas older patients had no distinct history of trauma. Joint levelling procedures produced good clinical results, but carpal height ratio, Stahl's index and radioscaphoid angle were not improved, as evidenced radiographically. Our study suggests that in a Japanese cohort ulnar minus variance is not an important factor in the aetiology of Kienböck's disease. Although joint levelling procedures improved the clinical results, they did not reverse lunate collapse or carpal alignment.

Adolescent↗