Osteogenic extracellular matrix sheet for bone tissue regeneration.

The application of extracellular matrix (ECM) sheets without a scaffold is not extensively reported in bone regenerative medicine. The aim of the present study was to demonstrate that an osteogenic ECM sheet (OECMS) can retain ECM integrity and growth factors to enhance bone formation in a rat non-union model. OECMS was produced from osteogenic cell sheets (OCS). Collagen and growth factor [bone morphogenetic protein 2 (BMP-2), vascular endothelial growth factors (VFGFs), basic fibroblast growth factor (bFGF) and transforming growth factor ß1 (TGF-ß1)] concentrations in the OECMS were quantified by enzyme-linked immunosorbent assay (ELISA). Next, hydroxyapatite (HA) constructs combined with OECMSs were implanted subcutaneously into the rats' backs to evaluate their osteoinductive capacity by histological evaluation. In addition, OECMSs were implanted in a rat femoral non-union model. 18 male Fischer 344 inbred rats were divided into OECMS and control groups. Fracture healing was evaluated by radiological and histological analyses at 2, 5 and 8 weeks and biological analysis at 8 weeks. Collagen I and growth factors were retained in the OECMSs. Osteoid formation was identified in the HA combined with OECMS at 4 weeks. Enhanced bone regeneration at the non-union of the OECMS group was confirmed at 5 and 8 weeks. Biomechanical testing revealed a significantly higher maximum bending load in the OECMS group as compared to the control group at 8 weeks. The results demonstrated that OECMS retained BMP-2 and TGF-ß1 and high osteoinductive and osteoconductive capacity. As such, OECMS represents a potential new scaffold-free material for bone tissue engineering.

Risk factors for dislocation of the ulnar nerve after simple decompression for cubital tunnel syndrome.

Anterior dislocation of the ulnar nerve is occasionally encountered after simple decompression of the nerve for treatment of cubital tunnel syndrome. The purpose of this study was to determine whether the incidence of dislocation of the nerve following simple decompression of the nerve is correlated with the patient's preoperative characteristics and/or elbow morphology. We studied 51 patients with cubital tunnel syndrome who underwent surgery at our institution. Intraoperatively, we simulated dislocation of the nerve after simple decompression by flexing the elbow after releasing the nerve in each patient. Univariate and multiple logistic regression analysis showed that young age and a small ulnar nerve groove angle are positively correlated with dislocation of the nerve. Our results suggest that patients who are young and/or have a sharply angled ulnar nerve groove identified radiographically have a high probability of experiencing anterior dislocation of the ulnar nerve after simple decompression.

Palmar reconstruction of the triangular fibrocartilage complex for instability of the distal radioulnar joint: a biomechanical study.

We developed a new triangular fibrocartilage complex reconstruction technique for distal radioulnar joint instability in which the palmar portion of the triangular fibrocartilage complex was predominantly reconstructed, and evaluated whether such reconstruction can restore stability of the distal radioulnar joint in seven fresh cadaver upper extremities. Distal radioulnar joint instability was induced by cutting all soft-tissue stabilizers around the distal ulna. Using a palmar approach, a palmaris longus tendon graft was sutured to the remnant of the palmar radioulnar and ulnocarpal ligaments. The graft was then passed through a bone tunnel created at the fovea and was sutured. Loads were applied to the radius, and dorsopalmar displacements of the radius relative to the ulna were measured using an electromagnetic tracking device in neutral rotation, 60° supination and 60° pronation. We compared the dorsopalmar displacements before sectioning, before reconstruction and after reconstruction. Dorsopalmar instability produced by sectioning significantly improved in all forearm positions after reconstruction.

Long-term follow-up of periarterial sympathectomy for chronic digital ischaemia.

This study investigates long-term clinical results (> 10 years) of periarterial sympathectomy in chronic ischaemic digits compared with intermediate-term results (3 years). Periarterial sympathectomy via the palm and volar wrist was carried out on 11 hands of seven patients with digital ischaemia but no gangrene or severe ulceration. The aetiology of ischaemia was Buerger's disease in four hands, collagen disease in three hands, and repetitive digital trauma in four hands. Subjective symptoms were evaluated at a mean follow-up period of 12 years. The efficacy of surgery was assessed objectively using thermography and plethysmography. Although five of seven patients continued on oral vasodilators and antiplatelet agents until the final follow-up, improvement of symptoms was maintained in all patients between intermediate- and long-term evaluations. Our results suggest that periarterial sympathectomy via the palm and wrist could prevent long-term aggravation of symptoms of chronic digital ischaemia when combined with adequate postoperative drug therapy.

Cell sheet injection as a technique of osteogenic supply.

We previously reported a new cell transplantation method utilizing injections of mesenchymal stem cell (MSC) sheets that have osteogenic potential. After subcutaneous transplantation without any scaffold, the sheet demonstrated in vivo bone formation. In the present study, we transplanted such sheets by injection into implanted ceramics and assessed whether the injectable MSC sheets could stimulate osteogenic integration of the ceramics. To fabricate MSC sheets, bone marrow cells cultured from femur shafts of 7-week-old rats were subcultured in regular 10-cm dishes containing dexamethasone and ascorbic acid phosphate until confluent. Each cell sheet was then lifted using a scraper. Porous ß-tricalcium phosphate (ß-TCP) disks (5 mm Φ×2 mm) were transplanted subcutaneously into the backs of the rats. Immediately following implantation, the sheets were injected around the disks via a 16G needle (immediate group). Cell sheets were also injected into the remaining implanted disks 1 week after disk implantation (1-wk group). Four weeks following sheet injection, radiography and histology revealed calcification and bone tissue around the harvested disks of the immediate group (eight disks exhibited bone formation/eight implanted disks), whereas calcification and bone tissue were observed in 50% of the samples in the 1-wk group (four disks exhibited bone formation/eight implanted disks). The present study indicates that injected cell sheets can supply osteogenic potential to implanted ceramics. Owing to the usage of a needle for cell sheet transplantation, such an injection method can be applied as a minimally invasive technique of osteogenic supply to implanted ceramics.

Comparison of responsiveness of the Japanese Society for Surgery of the Hand version of the carpal tunnel syndrome instrument to surgical treatment with DASH, SF-36, and physical findings.

BACKGROUND: The Japanese Society for Surgery of -the Hand version of the Carpal Tunnel Syndrome Instrument (CTSI-JSSH), which consists of two parts--one for symptom severity (CTSI-SS) and the other for functional status (CTSI-FS)--is a self-administered questionnaire specifically designed for carpal tunnel syndrome. The responsiveness of the CTSI-JSSH was compared with that of the JSSH version of the Disability of Arm, Shoulder, and Hand questionnaire (DASH), the official Japanese version of the 36-Item Short Form Health Survey (SF-36, version 1.2), and physical examinations to elucidate the role of the CTSI-JSSH for evaluating patients with carpal tunnel syndrome. METHODS: Preoperatively, a series of 60 patients with carpal tunnel syndrome completed the CTSI-JSSH, DASH, and SF-36. Results of physical examinations, including grip strength, pulp pinch, and static two-point discrimination of the thumb, index, and long fingers, were recorded. Three months after carpal tunnel release surgery the patients were asked to fill out the same questionnaires, and the physical examinations were repeated. The responsiveness of all the instruments was examined by calculating the standardized response mean (SRM) and effect size (ES). Correlation coefficients were calculated between questionnaire change scores and patient satisfaction scores as well as between the CTSI change scores and those of the DASH and SF-36. RESULTS: The largest responsiveness was observed in the CTSI-SS (SRM/ES: -1.00/-1.08) followed by the CTSI-FS (-0.76/-0.63), and bodily pain subscale of SF-36 (SF-36-BP, 0.45/0.55), and the DASH (-0.46/-0.47). Only the change scores of the CTSI-SS had significant correlation with patient satisfaction (r = 0.34, P < 0.01). An absolute value of Spearman's correlation coefficient of >0.5 was observed between the change scores of the CTSI-SS and the DASH, the CTSI-SS and the SF-36-BP, the CTSI-FS and the DASH, and the DASH and the SF-36-BP. CONCLUSION: The CTSI-JSSH was proven to be more sensitive to clinical changes after carpal tunnel release than the other outcome measures and should be used to evaluate patients with carpal tunnel syndrome who speak Japanese as their native language.

Anatomical consideration of vascularized bone graft transfer from the medial calcaneus to the talus.

To investigate the possibility of use of the calcaneal branches of the posterior tibial artery as the pedicle for the vascularized bone graft to the talus, a detailed anatomical study was carried out on 30 fresh cadaver feet. Although there are several branches from the posterior tibial artery to the calcaneus, the largest posterior branch was defined as the main calcaneal branch. We recognized frequently a large branch nourishing the superior part of the calcaneus and named it the superior calcaneal branch. Twenty feet had the superior calcaneal branches. Pedicled bone grafts using the superior calcaneal branch to the postero-medial portion of the talar body were possible in 18 of 20 feet. Pedicled bone grafts using the main calcaneal branches were possible in 9 of 12 feet in which the superior calcaneal branches were not available. Finally, vascularized bone grafts were judged to be feasible in 27 feet (90%).

The anatomical basis for reverse first to fifth dorsal metacarpal arterial flaps.

This study discusses the anatomical basis for reverse first to fifth dorsal metacarpal arterial flaps. The arterial pattern and size of the first to fifth dorsal metacarpal arteries were examined in 20 fresh cadaver hands. Their connections to the palmar arterial system at the metacarpal head were observed, and the location, number and diameter of skin perforators from each dorsal metacarpal artery were measured. The first to fourth dorsal metacarpal arteries were found in all specimens; the fifth dorsal metacarpal artery was found in 19 of our 20 specimens. The mean diameters of the first to fifth arteries at their bifurcation site were 0.6, 0.8, 0.5, 0.4 and 0.2 mm, respectively. Each artery gave off four to eight skin perforators (diameter: 0.1-0.3 mm) between the metacarpal head and base. The first to third dorsal metacarpal arteries consistently connected to the palmar arterial system, and connections between the fourth and fifth dorsal metacarpal arteries and the palmar system were found in 65% and 40% of specimens.

Anatomical consideration of reverse-flow island flap transfers from the midpalm for finger reconstruction.

Primary soft-tissue coverage for large palmar defects of the fingers is a difficult problem for cases in which homodigital or heterodigital flaps cannot be used. The aim of this study was to explore the vascular and neural anatomy of the midpalmar area to assess the possibility of reverse island flaps from this area. In 24 cadaver hands perfused with a silicone compound, the arterial pattern of the superficial palmar arch and common palmar digital artery was examined. The cutaneous perforating arteries and nerve branches supplying the midpalmar area were dissected, and the number, location, and arterial diameter of these branches were measured. In six other specimens, the common palmar digital artery was injected to determine the skin territory supplied by the artery. The superficial palmar arch contained the three common palmar digital arteries and its terminal branch coursed along the radial margin of the index metacarpus. This terminal branch had three to six cutaneous perforators (diameter range, 0.1 to 0.5 mm) and supplied the radial aspect of the midpalmar area located over the ulnar half of the adductor pollicis muscles. The midpalmar area was divided into two regions-the proximal and distal-according to the vascular distributions. The proximal region contained dense aponeurosis and thin subcutaneous tissue, and the cutaneous perforators were rather sparse (between three and nine) and had a small diameter (0.1 to 0.3 mm). The distal region, which had loose aponeurosis and abundant subcutaneous tissue, had a rich vascular supply from the common and proper digital artery. Perforating arteries of this region coursed frequently in an oblique fashion and the number of perforators (between eight and 15) and their arterial diameters (diameter range, 0.1 to 0.5 mm) were higher than those of the proximal region. The area of skin perfused by the common palmar digital artery was 5 x 3 cm at the distal midpalmar region. There were three to five cutaneous nerve branches from the palmar digital nerve supplying the midpalmar area. From this study, two different reverse flaps were proposed. First, a 5 x 2 cm flap from the distal midpalmar region was elevated on the basis of the common and proper palmar digital artery. Measurement of the rotation arc revealed that the pivot point of this flap was located at the proximal interphalangeal joint level and could cover the finger pulp of the digits. The second flap candidate was that from the radial aspect of the midpalm, which was supplied by the terminal branch of the superficial palmar arch. In studies with cadaver hands, connection of this artery with the deep arterial system enabled this flap to reach the thumb pulp. These flaps may be a useful reconstruction option for significant palmar soft-tissue loss of the fingers.

Current topics on centrifugal plasmapheresis technologies.

In the field of plasmapheresis centrifugal technology has recently focused on the collection of peripheral blood stem cells (PBSCs) for both autologous and allogeneic transplantation in patients with malignancies or hematological diseases and on donor plasmapheresis. PBSC transplantation is rapidly replacing bone marrow transplantation in such patients. Various kinds of apheresis equipment were applied and described for PBSC collection. Comparison among machines is described. Allogeneic PBSCs were collected from healthy normal donors. Specific attention to the dose and administration duration of granulocyte colony-stimulating factor and a careful apheresis procedure should be made for donor safety. In platelet transfusion practice, a platelet concentrate product derived plateletpheresis from a single donor is preferable to minimize and to prevent adverse transfusion reactions. The status of platelet collection and its efficacy by various kinds of plateletpheresis equipment are discussed. The Amicus and CCS might be preferable plateletpheresis machines because of their collection efficiencies and wider indication for donors. With the limited number of donors, it is essential that plateletpheresis should be more effectively performed and managed by each regional blood center. The status of plasma and red cell collection by apheresis technologies is described also briefly.

Status of platelet collection and platelet transfusion.

Platelet product derived from single donor plateletpheresis is required to reduce the risks of adverse reactions by blood transfusion. The objectives of this study are to evaluate the status of platelet collection and its efficacy by various kinds of plateletpheresis equipment and to assess the achievement of platelet transfusion by platelet product derived from a single donor. Since the blood centers have introduced some kinds of efficient plateletpheresis equipment, large units of platelet products have been supplied mainly for the patients. Amicus and CCS might be preferable plateletpheresis machines because of their collection efficiencies and wider indication for donors. The average number of donors of platelet product per patient has recently reached nearly 1.0, and around 90% of patients have received platelet product derived from a single donor in the recent several years. However, platelet transfusion derived from a single donor has not yet been completely achieved. Each regional blood center should seriously consider the efficacy of each plateletpheresis equipment and arrange the equipment to collect platelets more effectively to achieve platelet transfusion from a single donor.

Innervated radial thenar flap combined with radial forearm flap transfer for thumb reconstruction.

A radial thenar flap combined with radial forearm flap was used for the reconstruction of the ipsilateral thumb in four patients. Vascular supply of the combined flap was based on the radial artery and extending the vascular pedicle to the superficial palmar branch of the radial artery. The flap was sensated by the palmar branch of the superficial radial nerve. The size of the flap averaged 15 x 5 cm and the innervated region of the thenar eminence was an area approximately 5 x 3 cm located over the proximal parts of the abductor pollicis brevis and opponens pollicis muscles. The flap was transferred as a free flap in three patients and as an advancement flap in one patient. The flaps survived completely without complications. Satisfactory restoration of sensation was achieved in the flap area, as shown by 6 mm of average moving two-point discrimination. This combined flap may be a feasible reconstructive option for large palmar defects of the fingers such as degloving injuries.

Development of a rapid blood transfusion system with the capability of blood purification.

Blood is usually irradiated by x-ray to prevent graft-versus-host-disease. However, plasma potassium levels of irradiated blood are rapidly increased during preservation in irradiated blood. The objectives of this study were to develop a rapid blood transfusion system for which irradiated blood can be used and to evaluate the capability of blood purification of the system. Packed red blood cells (RBC) were irradiated (15 Gy x-ray) at 21 days and preserved until 42 days after collection. A blood mixture of RBC and plasma was perfused through a dialyzer at 25, 50, 100, and 200 ml/min. Dialysate was perfused at 100, 100, 500, and 500 ml/min, respectively. Preperfusion levels of sodium, 121; potassium, 35; and chlorine, 76 mEq/L were changed to sodium, 144 to 146; potassium 2.5 to 3.0; and chlorine, 105 to 110 mEq/L, which were comparable with the levels in dialysate after perfusion for 25, 50, and 100 ml/min perfusion groups. For the 200 ml/min perfusion group, potassium was 5.3 mEq/L after perfusion which was slightly higher than other groups, but 84% of the potassium was removed by the system. Citrate levels were significantly decreased to 3.4, 28, 31, and 81 mg/dl for the 25, 50, 100, and 200 ml/min groups, respectively, after perfusions. The rapid transfusion system composed of the dialyzer and the blood pumps was effective in the removal of potassium and in the normalization of electrolytes. Irradiated blood with high levels of potassium can be safely and effectively used for this system in cases requiring massive rapid blood transfusion.

A reverse ulnar hypothenar flap for finger reconstruction.

A reverse-flow island flap from the hypothenar eminence of the hand was applied in 11 patients to treat palmar skin defects, amputation injuries, or flexion contractures of the little finger. There were three female and eight male patients, and their ages at the time of surgery averaged 46 years. A 3 x 1.5 to 5 X 2 cm fasciocutaneous flap from the ulnar aspect of the hypothenar eminence, which was located over the abductor digiti minimi muscle, was designed and transferred in a retrograde fashion to cover the skin and soft-tissue defects of the little finger. The flap was based on the ulnar palmar digital artery of the little finger and in three patients was sensated by the dorsal branch of the ulnar nerve or by branches of the ulnar palmar digital nerve of the little finger. Follow-up periods averaged 42 months. The postoperative course was uneventful for all patients, and all of the flaps survived without complications. The donor site was closed primarily in all cases, and no patient complained of significant donor-site problems. Satisfactory sensory reinnervation was achieved in patients who underwent sensory flap transfer, as indicated by 5 mm of moving two-point discrimination. A reverse island flap from the hypothenar eminence is easily elevated, contains durable fasciocutaneous structures, and has a good color and texture match to the finger pulp. This flap is a good alternative for reconstruction of palmar skin and soft-tissue defects of the little finger.

Trapeziometacarpal joint instability affects the moment arms of thumb motor tendons.

This study measured the changes in moment arm length of thumb motor tendons after simulated ligamentous instability and subsequent reconstruction of the trapeziometacarpal joint. Excursions of thumb motor tendons were measured simultaneously with the trapeziometacarpal joint angulation during flexion to extension and abduction to adduction motion. Tendon moment arms were calculated based on joint and tendon displacement techniques in the intact joint, after sequential sectionings of the capsuloligamentous restraints, and after the reconstruction procedure of Eaton and Littler. The results showed that moment arms of the abductor pollicis longus and extensor pollicis brevis tendons increased significantly as compared with those for normal joints during flexion to extension motion after sectioning the palmar capsuloligamentous components. After the ulnopalmar structures were cut, the moment arm of the extensor pollicis longus tendon had a statistically significant increase during abduction to adduction motion, and those of the extensor and flexor pollicis longus tendons decreased significantly during flexion to extension motion. Changed moment arms were restored to a normal level after the ligamentous reconstruction. These results indicate that ligamentous disruptions alter the mechanical balance of thumb motor tendons, which may contribute to joint deformities observed in trapeziometacarpal joint arthritis. Restoring joint stability is important to correct mechanical imbalance of the tendons.

Evaluation of efficacy in platelet collection by the Haemonetics Component Collection System.

Platelet concentrate product derived from plateletpheresis from a single donor is preferable in terms of reducing the risks of adverse reactions in platelet transfusion. This study evaluated the status of platelet transfusion and the efficacy and safety of plateletpheresis machines. The average number of donors of platelet product per patient has been decreasing and recently reached nearly 1.0; however, some patients still receive multiple random donor platelet products. Platelet collection efficacy was comparable between the Haemonetics Component Collection System (CCS) and the Multi Component System (Multi). However, the CCS has been shown to be effective in terms of processed blood volume and procedure time, especially in donors with lower hematocrits. These results suggest that the CCS may be preferable and safer for donors with lower hematocrits and lighter body weights. Blood centers should collect platelets more effectively to achieve platelet transfusion with the use of platelets derived from a single donor using effective equipment.

Biomechanical evaluation of wrist motor tendons after fractures of the distal radius.

We conducted a biomechanical study of changes in parameters of wrist motor tendons in fractures of the distal radius in 7 cadaveric extremities. Extra-articular distal radius fractures were simulated by distal radius osteotomy and fracture angulation was maintained by external fixators. Eight positions of the distal radius fractures were studied: dorsal angulation of 10 degrees, 20 degrees, 30 degrees, and 40 degrees and radial angulation of 5 degrees, 10 degrees, 15 degrees, and 20 degrees. Dorsal and radial angulation of the fractures were measured with respect to the shaft of the radius. Excursions of 5 principal wrist motor tendons extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris were recorded simultaneously with wrist joint angulation using a computer-assisted recording system. Data were collected from intact wrists and from wrists with fractures at each of 8 positions of angulation during wrist flexion and extension and radical and ulnar deviation. Moment arm of the wrist motor tendons was derived from tendon excursion and joint angulation. The results demonstrated that excursions and moment arms of principal wrist motor tendons are significantly affected by dorsal and radial angulation of distal radius fractures. Amplitude of changes in moment arms increased as the deformities became more severe. Statistical analysis revealed that dorsal angulation of 10 degrees or more significantly affected moment arms of all the prime wrist motors. Dorsal angulation of 30 degrees or 40 degrees changed the moment arms greatly. Radial angulation of 5 degrees did not affect moment arms of the tendons and angulation over 10 degrees had a statistically significant effect on the tendons. We conclude that deformities of distal radius fractures have a significant influence on the biomechanics of the wrist motors.

Biomechanical changes of the wrist flexor and extensor tendons following loss of scaphoid integrity.

Loss of integrity of the scaphoid may change the motion center of the entire carpus, and deformities from scaphoid fractures may alter the location of motor tendons of the wrist, thus altering their biomechanics. The goal of this study was to clarify biomechanical changes in these tendons following loss of scaphoid integrity. Excursions and moment arms of the principal flexor and extensor tendons of the wrist were investigated in seven cadaveric upper extremities in intact wrists after simulation of scaphoid waist fracture and after removal of the proximal scaphoid. Excursions of the flexor carpi radialis and ulnaris, extensor carpi radialis longus and brevis, and extensor carpi ulnaris tendons were measured with rotary potentiometers during wrist flexion-extension and radioulnar deviation. Simultaneously, wrist joint angulation was recorded. Moment arms of the tendons were derived from tendon excursions and joint motion. After scaphoid fracture, the moment arms of the flexor carpi radialis and extensor carpi ulnaris tendons increased significantly during wrist flexion-extension, whereas the moment arms of the extensor carpi radialis longus and brevis tendons decreased significantly. After proximal scaphoid excision, the moment arms of the extensor carpi radialis longus and brevis tendons again decreased significantly during wrist flexion-extension. The moment arms of the flexor carpi radialis and extensor carpi radialis brevis tendons increased significantly during radioulnar deviation, whereas those of the wrist motors on the ulnar side decreased. These findings indicate the importance of the integrity of the scaphoid in maintaining normal biomechanics of motor tendons of the wrist. An increase in the moment arm of the radial wrist flexor along with a decrease in moment arms of the radial extensors constitutes as etiology for persistent angulation of the scaphoid and the humpback deformity. In addition, disturbing the biomechanics of the wrist motor tendons predisposes the carpal joints to abnormal loading, potentially contributing to the development of carpal joint degeneration.

Vascular and neural anatomy of the thenar area of the hand: its surgical applications.

Thirty fresh cadaver hands were injected with a silicone rubber compound (Microfil) and dissected to examine the vascular and neural supplies of the thenar area. In 10 specimens, a selective injection technique was used to determine the extent of skin territory nourished by the superficial palmar branch of the radial artery. The purpose of this study was to clarify the anatomic basis for clinical applications of vascularized free- or island-flap transfers from the thenar area. The superficial palmar branch of the radial artery was found in all hands; the average diameter of the branch measured at its bifurcation site was 1.4 mm (0.8 to 3.0 mm). The constant area nourished by the superficial palmar branch was an area approximately 4 x 3 cm located over the proximal parts of the abductor pollicis brevis and opponens pollicis muscles. These results indicate that a fasciocutaneous flap from the radial thenar region can be raised based on the superficial palmar branch and consistently transferred as a free flap. In 63 percent of the hands dissected, the superficial palmar branch was connected to other arteries in the palm, suggesting that the flap can be transferred as a reverse-pedicle island flap in such hands. Innervation of the flap was provided chiefly by a branch of the superficial radial nerve. The radial aspect of the thenar eminence can provide a new and useful donor source for an innervated and vascularized free- or island-flap transfer for reconstruction of various skin defects of the volar side of the fingers.