Silicate/zinc-substituted strontium apatite coating improves the osteoinductive properties of ß-tricalcium phosphate bone graft substitute.

BACKGROUND: ß-Tricalcium phosphate (ß-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of ß-TCP could enhance osteoinductive properties. METHODS: The apatite-coated ß-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP). Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated ß-TCP disks. In vitro, the ß-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the ß-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically. RESULTS: Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group. CONCLUSIONS: Our findings indicate that apatite coating of ß-TCP improves osteoinductive properties without inducing significant cytotoxicity.

Biomechanical comparison of arthroscopic and open lunate excisions in the cadaveric wrist.

BACKGROUND: In advanced Kienböck disease, unreconstructible lunate should be excised as a salvage procedure. There is a lack of information about the biomechanical approaches evaluating the carpal kinematics after lunate excision. We hypothesized that arthroscopic lunate excision would not break the ring structure of the proximal carpal row, preventing carpal instability. We aimed to investigate changes in carpal kinematics following arthroscopic and open lunate excisions. METHODS: We used upper extremities from five fresh cadavers and simulated arthroscopic and open lunate excisions. Arthroscopic lunate excision was performed to preserve the attachment sites of intrinsic and extrinsic carpal ligaments to the lunate. Open lunate excision was conducted with sectioning of the intrinsic and extrinsic carpal ligaments. Using a three-dimensional space electromagnetic tracking device, rotation angles of the scaphoid and triquetrum and the change of scaphotriquetrum distance were measured under axial loading. We compared the rotation angles and the change of scaphotriquetrum distance among intact wrists, open, and arthroscopic lunate excisions. FINDINGS: No Significant differences in the rotation angle of the scaphoid and triquetrum or the change of scaphotriquetrum distance were found between intact wrist and arthroscopic lunate excision. The triquetrum significantly dorsiflexed and supinated in wrists with open lunate excisions compared with intact wrists. Significant differences in the change of scaphotriquetrum distance were found between intact and openly excised wrists and between arthroscopic and open excisions. INTERPRETATION: Arthroscopic lunate excision potentially prevented kinematic change of the proximal carpal row under axial loading by maintaining the integrity of attachment sites of carpal ligaments.

Biomechanical analysis of simultaneous distal and proximal radio-ulnar joint instability.

BACKGROUND: Simultaneous dislocation of the proximal and distal radio-ulnar joints without bony injuries has been reported, but the mechanism remains unclear. We investigated concurrent proximal and distal radio-ulnar joint instability after sequential sectioning of the annular ligament, triangular fibrocartilage complex, and quadrate ligament. METHODS: We performed this biomechanical study with six fresh-frozen cadaveric upper extremities. Proximal and distal radio-ulnar joint displacement was measured using an electromagnetic tracking device during passive mobility testing with anterior, lateral, and posterior loads on the radial head with pronation, supination, and neutral rotation. Measurements were statistically analyzed using the generalized linear mixed model. FINDINGS: Proximal radio-ulnar joint instability was significantly greater after sectioning of the annular (lateral: 1.4%, P < .05; posterior: 0.7%, P < .05) and quadrate (lateral: 43.7%, P < .05; posterior: 29.5%, P < .05) ligament. Distal radio-ulnar joint instability was significantly greater in every sequential stage (final stage: anterior: 24.1%, P < .05; lateral 21.0%, P < .05; posterior: 31.3%, P < .05). Finally, significant simultaneous instability of the joints was observed after sectioning of the annular ligament, triangular fibrocartilage complex, and quadrate ligament, and neutral rotation potentially induced gross instability. INTERPRETATION: Our ligament injury model induced simultaneous proximal and distal radio-ulnar joint instability without bony or interosseous membrane injury, probably induced by severe soft tissue injury. Proximal radio-ulnar joint instability may influence distal radio-ulnar joint instability from pivoting of the interosseous membrane. Our findings will help surgeons evaluate the magnitude of soft tissue injury and plan surgery for patients with simultaneous proximal and distal radio-ulnar joint instability.

Robust method to create a standardized and reproducible atrophic non-union model in a rat femur.

OBJECTIVE: No evidence exists about which biological approach is more reliable for creating non-union model. We investigated how to create a reproducible atrophic non-union model in a rat femur. METHODS: We compared three groups: simple osteotomy (group A), partial periosteum cauterization (group B), and extensive periosteum and bone marrow resection (group C). RESULTS: All samples in group C demonstrated atrophic non-union in radiological, histological, and biomechanical analyses, however half of the samples in group B showed fracture healing at week 16. CONCLUSION: Extensive resection of periosteum and bone marrow is important for a reproducible atrophic non-union model in a rat femur.

Safe zone of pin insertion for nonbridging external fixators in distal radial fractures: MRI analysis.

BACKGROUND: Of the anatomical reduction and fixation methods used to treat distal radius fracture, non-bridging external fixation has the advantage of enabling early wrist motion. The surgical technique relies on successful placement of the pin in individual fracture fragments. The present study aimed to identify the safe zone of pin insertion for a non-bridging external fixator into the distal radius that avoids metal impingement of extensor tendons. METHODS: The width and length of the septal attachments of the extensor retinaculum were measured on axial MR images of 62 wrists. RESULTS: The 2-3 septum was the widest and longest, with a width of 2-7 mm and a location 0-36 mm proximal to the wrist joint. The width of the 1-2 septum was 2-6 mm, and was widest at 10 mm proximal to the joint. The 1-2 septum was triangular-shaped, while the 2-3 septum was oval-shaped. The 3-4 and 4-5 septa had narrow attachments and were adequate for pin insertion (with a pin 1-2 mm in width) at a position less than 8 mm proximal to the wrist. The width of the 1 R septum (radial to the 1st septum) was 2-6 mm at the radiovolar aspect of the wrist. CONCLUSIONS: There were two safe pin insertion sites; the first was safe at the distal aspect only (8-10 mm proximal to the wrist) and included the 1-2, 3-4, and 4-5 septa, while the second was safe from 0 mm to 32-38 mm proximal to the wrist and included the 1 R and the 2-3 septa. The 1 R septum had adequate size for use as a new pin insertion site that aligns in the internervous plane and has minimal risk of superficial radial nerve injury.

Effect of soft tissue injury and ulnar angulation on radial head instability in a Bado type I Monteggia fracture model.

The effects of soft tissue damage and ulnar angulation deformity on radial head instability in Monteggia fractures are unclear. We tested the hypothesis that radial head instability correlates with the magnitude of ulnar angular deformity and the degree of proximal forearm soft tissue injury in Bado type I Monteggia fractures.We performed a biomechanical study in 6 fresh-frozen cadaveric upper extremities. Monteggia fractures were simulated by anterior ulnar angulation osteotomy and sequential sectioning of ligamentous structures. We measured radial head displacement during passive mobility testing in pronation, supination, and neutral rotation using an electromagnetic tracking device. Measurements at various ligament sectioning stages and ulnar angulation substages were statistically compared with those in the intact elbow.Radial head displacement increased with sequential ligament sectioning and increased proportionally with the degree of anterior ulnar angulation. Annular ligament sectioning resulted in a significant increase in displacement only in pronation (P < .05). When the anterior ulnar deformity was reproduced, the radial head displaced least in supination. The addition of proximal interosseous membrane sectioning significantly increased the radial head displacement in supination (P < .05), regardless of the degree of anterior ulnar angulation.Our Monteggia fracture model showed that radial head instability is influenced by the degree of soft tissue damage and ulnar angulation. Annular ligament injury combined with a minimal (5°) ulnar deformity may cause elbow instability, especially in pronation. The proximal interosseous membrane contributes to radial head stability in supination, regardless of ulnar angulation, and proximal interosseous membrane injury led to significant radial head instability in supination.

Effects of 7 T static magnetic fields on the expression of biological markers and the formation of bone in rats.

In this study, we aimed to evaluate the effects of 7 T static magnetic fields (SMFs) on rat mesenchymal stem cells (MSCs) in order to determine whether strong SMFs affected the osteogenesis of MSCs. MSCs were prepared from bone marrow cells obtained from the femurs of 7-week-old male Fischer 344 rats. MSCs were then combined with ß-tricalcium phosphate (ß-TCP), yielding two types of TCP/MSC constructs (TCP/P-1 and P-2) on day 0. Exposure was performed for 3 h/day for 6 days, and the experiments were performed twice using different exposure apparatus (cryovials or 4-well chambers) for each experiment. The results from gene expression, protein expression, and histological analyses showed no reproducible effects on both TCP/P-1 and TCP/P-2 MSC constructs, although osteocalcin levels for TCP/P-1 MSC constructs increased significantly once after 7 T exposure in two experiments. These findings contribute to understanding the effects of strong SMFs on MSC and osteoblasts. Bioelectromagnetics. 40:16-26, 2019. © 2018 Wiley Periodicals, Inc.

Osteogenesis of osteogenic matrix cell sheets preserved in culture medium in a rat model.

Osteogenic matrix cell sheets (OMCSs) are ideal for bone regeneration. Transportation of OMCSs may be necessary, during which their osteogenic ability must be maintained. Here, we evaluated different media and temperatures for OMCS preservation. Bone marrow stromal/stem cells (BMSCs) were obtained from Fischer rats and analyzed for stem cell markers by flow cytometry. OMCSs were prepared from BMSCs by treatment with dexamethasone and ascorbic acid phosphate. After OMCS collection, they were stored in minimum essential medium (MEM) or Hank's balanced salt solution (HBSS) at 37, 22, or 4°C for 24 hours. Cell viability and cytotoxic effects in the preservation conditions were determined by adenosine triphosphate (ATP) contents and lactate dehydrogenase (LDH) release, respectively. Osteogenesis was assessed by subcutaneously implanting preserved OMCSs around ß-tricalcium phosphate ceramic disks into syngeneic rats. Implants were evaluated by alkaline phosphatase (ALP) activities, osteocalcin contents, and histology. Mesenchymal stem cells comprised 51% of primary cultured BMSCs. ATP contents were significantly different in OMCSs stored in MEM or HBSS at 22°C and 4°C. LDH release was significantly different in OMCSs stored in HBSS at 22°C and 4°C. The highest LDH release was observed in OMCSs stored in HBSS at 37°C. ALP activities and osteocalcin contents were the lowest in implanted OMCSs stored in HBSS at 37°C at four weeks after subcutaneous implantation. There was a significant difference in the osteocalcin levels of implanted OMCSs stored in MEM at 37°C and HBSS at 4°C. Abundant bone tissue around and inside disks was found in histological sections of OMCSs stored in all preservation conditions except for MEM and HBSS at 37°C. Maintaining the osteogenic ability of OMCSs during transport is important, and preservation of OMCSs in MEM or HBSS at 4°C or 22°C is a simple and inexpensive method.

Supplying osteogenesis to dead bone using an osteogenic matrix cell sheet.

PURPOSE: To evaluate whether osteogenic matrix cell sheets can supply osteogenesis to dead bone. METHODS: Femur bone fragments (5 mm in length) were obtained from Fisher 344 rats and irradiated by a single exposure of 60 Gy to produce bones that were no longer viable. Osteogenic matrix cell sheets were created from rat bone marrow-derived stromal cells (BMSCs). After wrapping the dead bone with an osteogenic matrix cell sheet, it was subcutaneously transplanted into the back of a rat and harvested after 4 weeks. Bone formation around the dead bone was evaluated by X-ray imaging and histology. Alkaline phosphatase (ALP) and osteocalcin (OC) mRNA expression levels were measured to confirm osteogenesis of the transplanted bone. The contribution of donor cells to bone formation was assessed using the Sry gene and PKH26. RESULTS: After the cell sheet was transplanted together with dead bone, X-ray images showed abundant calcification around the dead bone. In contrast, no newly formed bone was seen in samples that were transplanted without the cell sheet. Histological sections also showed newly formed bone around dead bone in samples transplanted with the cell sheet, whereas many empty lacunae and no newly formed bone were observed in samples transplanted without the cell sheet. ALP and OC mRNA expression levels were significantly higher in dead bones transplanted with cell sheets than in those without a cell sheet (P < 0.01). Sry gene expression and cells derived from cell sheets labeled with PKH26 were detected in samples transplanted with a cell sheet, indicating survival of donor cells after transplantation. CONCLUSION: Our study indicates that osteogenic matrix cell sheet transplantation can supply osteogenesis to dead bone.

Implantation of Bone Marrow Stromal Cell Sheets Derived from Old Donors Supports Bone Tissue Formation.

The purpose of this study was to evaluate the osteogenesis ability of osteogenic matrix cell sheets (OMCS) derived from old donor cells. Bone marrow stromal cells (BMSC) were obtained from young (7-week-old) and old (1-year-old) Fischer344 rats donors and cultured with modified Eagle's medium (MEM group) alone or containing dexamethasone (Dex; 10 nM) and ascorbic acid phosphate (AscP; 0.28 mM) (Dex/AscP group). We prepared four in vitro experimental groups: (1) young MEM, (2) young Dex/AscP, (3) old MEM and (4) old Dex/AscP. Cell proliferation and osteogenic marker mRNA expression levels were evaluated in vitro. To assess bone formation in vivo, the cells of each group were combined with beta tricalcium phosphate (TCP) disks followed by implantation in recipient rats. The in vitro study showed significant differences in the mRNA expression of osteocalcin, ALP, and BMP2 between MEM and Dex/AscP groups. Bone formation following implantation was observed upon histological analyses of all groups. TCP combined with OMCS (OMCS/TCP group) resulted in enhanced bone formation compared to that following combination with BMSC (BMSC/TCP). The osteocalcin content of the OMCS/TCP group 4 weeks after implantation was significantly higher than that in the BMSC/TCP construct for both young and old donors. The present study clearly indicated that OMCS could be generated from BMSCs of old as well as young donors using a mechanical retrieval method. Thus, through its usage of OMCS, this method may represent a potentially effective therapeutic option for cell-based therapy in elderly patients.

Bone regeneration with osteogenic matrix cell sheet and tricalcium phosphate: An experimental study in sheep.

AIM: To determine the effects of a cell sheet created from sheep bone marrow and tricalcium phosphate (TCP) on osteogenesis. METHODS: Bone marrow cells were harvested from a sheep and cultured in a minimal essential medium (MEM) containing ascorbic acid phosphate (AscP) and dexamethasone (Dex). After 2 wk, the formed osteogenic matrix cell sheet was lifted from the culture dish using a scraper. Additionally, harvested bone marrow cells were cultured in MEM only as a negative control group, and in MEM with AscP, Dex, and ß-glycerophosphate as a positive control group. For in vitro evaluation, we measured the alkaline phosphatase (ALP) activity and osteocalcin (OC) content in the media of the cultured cells from each group. For in vivo analysis, a porous TCP ceramic was used as a scaffold. We prepared an experimental group comprising TCP scaffolds wrapped with the osteogenic matrix cell sheets and a control group consisting of the TCP scaffold only. The constructs were implanted subcutaneously into athymic rats and the cell donor sheep, and bone formation was confirmed by histology after 4 wk. RESULTS: In the in vitro part, the mean ALP activity was 0.39 ± 0.03 mg/well in the negative control group, 0.67 ± 0.04 mg/well in the sheet group, and 0.65 ± 0.07 mg/well in the positive control group. The mean OC levels were 1.46 ± 0.33 ng/well in the negative control group, 3.92 ± 0.16 ng/well in the sheet group, and 4.4 ± 0.47 ng/well in the positive control group, respectively. The ALP activity and OC levels were significantly higher in the cell sheet and positive control groups than in the negative control group (P < 0.05). There was no significant difference in ALP activity or OC levels between the cell sheet group and the positive control group (P > 0.05). TCP constructs wrapped with cell sheets prior to implantation showed bone formation, in contrast to TCP scaffolds alone, which exhibited poor bone formation when implanted, in the subcutaneous layer both in athymic rats and in the sheep. CONCLUSION: This technique for preparing highly osteoinductive TCP may promote regeneration in large bone defects.

Modifying oxygen tension affects bone marrow stromal cell osteogenesis for regenerative medicine.

AIM: To establish a hypoxic environment for promoting osteogenesis in rat marrow stromal cells (MSCs) using osteogenic matrix cell sheets (OMCSs). METHODS: Rat MSCs were cultured in osteogenic media under one of four varying oxygen conditions: Normoxia (21% O2) for 14 d (NN), normoxia for 7 d followed by hypoxia (5% O2) for 7 d (NH), hypoxia for 7 d followed by normoxia for 7 d (HN), or hypoxia for 14 d (HH). Osteogenesis was evaluated by observing changes in cell morphology and calcium deposition, and by measuring osteocalcin secretion (ELISA) and calcium content. In vivo syngeneic transplantation using OMCSs and ß-tricalcium phosphate discs, preconditioned under NN or HN conditions, was also evaluated by histology, calcium content measurements, and real-time quantitative PCR. RESULTS: In the NN and HN groups, differentiated, cuboidal-shaped cells were readily observed, along with calcium deposits. In the HN group, the levels of secreted osteocalcin increased rapidly from day 10 as compared with the other groups, and plateaued at day 12 (P < 0.05). At day 14, the HN group showed the highest amount of calcium deposition. In vivo, the HN group showed histologically prominent new bone formation, increased calcium deposition, and higher collagen type I messenger RNA expression as compared with the NN group. CONCLUSION: The results of this study indicate that modifying oxygen tension is an effective method to enhance the osteogenic ability of MSCs used for OMCSs.

Importance of anterior humeral line for successful anatomical reduction in the surgical treatment of pediatric supracondylar humeral fractures.

Anterior humeral line (AHL) and tilting angle (TA) are used for the assessment of pediatric elbow sagittal plane alignment in surgical treatment of pediatric supracondylar humeral fracture. However, few studies exist that compare the reliabilities between these parameters. The purpose of this study is to determine whether measurements of radiographic parameters are reliable and useful for achieving anatomical reduction. In the current study, we demonstrated that the identifying the AHL location involves a simple and reliable measurement compared with TA. The intraoperative AHL identification is a good indicator for achieving anatomical reduction.

A Biomechanical Perspective on Distal Radioulnar Joint Instability.

Background The purpose of this article was to review the anatomy, kinematics of the distal radioulnar joint (DRUJ), and to discuss definition, classification, and diagnosis of DRUJ instability. Methods A biomechanical perspective on physical examination of DRUJ ballottement test was documented. Physiological dynamic DRUJ translation and differences of the translation following sequential ligament sectioning and changes in different forearm and wrist positions were demonstrated. The clinical significance of each ligament's contribution to joint stability in specific wrist positions was addressed. Conclusion Each ligament stabilizing the DRUJ contributed to joint stability depending on the direction (palmer or dorsal) and different positions of the wrist and forearm. DRUJ ballottement test in each wrist and forearm position may detect tears of specific ligament stabilizing the DRUJ.

Biomechanical study of distal radioulnar joint ballottement test.

We investigated the reliability and accuracy of the distal radioulnar joint (DRUJ) ballottement test using five fresh-frozen cadaver specimens in triangular fibrocartilage complex (TFCC)-intact, and TFCC-sectioned wrists. The humerus and proximal ulna were fixed. The ulna was allowed to translate in dorsopalmar directions without rotation, and the radius was allowed to move freely. Four sensors of a magnetic tracking system were attached to the radius and ulna, and the nails of each examiner's thumbs. Five examiners conducted the DRUJ ballottement test before and after TFCC sectioning. We used two techniques: With holding and without holding the carpal bones to the radius (holding and non-holding tests, respectively). We compared the magnitudes of bone-to-bone (absolute DRUJ) movement with that of the examiner's nail-to-nail (relative DRUJ) movement. The intrarater intraclass correlation coefficients (ICCs) were 0.92 (holding) and 0.94 (non-holding). The interrater ICCs were 0.84 (holding) and 0.75 (non-holding). Magnitudes of absolute and relative movements averaged 11.5 and 11.8 mm, respectively (p < 0.05). Before TFCC sectioning, the DRUJ movement during the holding and non-holding techniques averaged 9.8 and 10.8 mm, respectively (p < 0.05). The increase in DRUJ movement after TFCC sectioning was greater with the holding technique (average 2.3 mm) than with the non-holding technique (average 1.6 mm). The DRUJ ballottement test with magnetic markers is relatively accurate and reliable for detecting unstable joints. We recommend the holding technique for assessing DRUJ instability in clinical practice. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1123-1127, 2017.

Calcium Concentration in Culture Medium as a Nondestructive and Rapid Marker of Osteogenesis.

Artificial bones made of ß-tricalcium phosphate (ß-TCP) combined with bone marrow-derived mesenchymal stromal cells (BM-MSCs) are used for effective reconstruction of bone defects caused by genetic defects, traumatic injury, or surgical resection of bone tumors. However, the selection of constructs with high osteogenic potential before implantation is challenging. The purpose of this study was to determine whether the calcium concentration in BM-MSC culture medium can be used as a nondestructive and simple osteogenic marker for selecting tissue-engineered grafts constructed using ß-TCP and BM-MSCs. We prepared three cell passages of BM-MSCs derived from three 7-week-old, male Fischer 344 rats; the cells were cultured in osteoinductive medium in the presence of ß-TCP for 15 days. The medium was replaced with fresh medium on day 1 in culture and subsequently changed every 48 h; it was collected for measurement of osteocalcin secretion and calcium concentration by enzyme-linked immunosorbent assay and X-ray fluorescence spectrometry, respectively. After cultivation, the constructs were implanted subcutaneously into the backs of recipient rats. Four weeks after implantation, the alkaline phosphatase (ALP) activity and osteocalcin content of the constructs were measured. A strong inverse correlation was observed between the calcium concentration in the medium and the ALP activity and osteocalcin content of the constructs, with Pearson's correlation coefficients of 0.92 and 0.90, respectively. These results indicate that tissue-engineered bone with high osteogenic ability can be selected before implantation based on low calcium content of the culture medium, resulting in successful bone formation after implantation. This nondestructive, simple method shows great promise for assessing the osteogenic ability of tissue-engineered bone.

Septic arthritis of the wrist caused by Mycobacterium intracellulare: a case report.

Septic arthritis of the wrist is rare entity, especially; atypical mycobacterial infection of the wrist is extremely rare. We report a case of septic arthritis of the wrist caused by Mycobacterium intracellulare, which was successfully treated by radical debridement followed by wrist arthrodesis using vascularised fibular grafting.

Vascularized Bone Grafts from the Dorsal Wrist for the Treatment of Kienböck Disease.

Purpose The objective of this article is to evaluate functional and radiological outcomes of vascularized bone grafts for stage 2 and 3 Kienböck disease. The outcomes of three different donor sites via dorsal approach of the wrist were compared. Pearls and pitfalls in surgical technique were discussed. Methods There were 28 patients who underwent vascularized bone grafts, including the extensor fourth and fifth compartmental artery graft of distal radius in 8 patients, the first and second supraretinacular intercompartmental artery graft of distal radius in 12 patients, and the second dorsal metacarpal neck graft in 8 patients. Average age was 32 years, and radiological grading according to Lichtman classification was stage 2 in 8 patients, stage 3A in 10 patients, and stage 3B in 10 patients. Temporary pinning fixing the midcarpal joint was conducted for 10 weeks postoperatively. Results Follow-up periods averaged 70 months. Pain reduced in 27 patients, and visual analog scale for pain of pre- and postoperative level averaged 59 and 18. Range of wrist flexion and extension motion improved from 87 to 117 degrees, and average grip strength improved from 21 kg preoperatively to 33 kg postoperatively. Carpal height ratio had almost no change from 0.52 to 0.53. Fragmentation of necrotic bone healed in 7 of the 14 cases. Comparative analyses of functional and radiological outcomes between three donor sites found no significant difference. Conclusion Three different vascularized bone grafts from the dorsal wrist and hand area demonstrated favorable and comparable functional outcomes. It was technically important to elevate vascular bundle with surrounding retinaculum or fascia, to include sufficient periosteum, and to insert the vascularized bone as the cortex aligned longitudinally.

Effectiveness of Bone Marrow Stromal Cell Sheets in Maintaining Random-Pattern Skin Flaps in an Experimental Animal Model.

BACKGROUND: Bone marrow stromal cells can be applied therapeutically to enhance angiogenesis; however, the use of bone marrow stromal cell suspensions reduces efficiency because of low-level attachment. The authors hypothesized that bone marrow stromal cell sheets would facilitate cell fixation, thus enhancing angiogenesis. The authors investigated flap survival area and enhancement of angiogenic factors in a rat random-pattern skin flap model after application of bone marrow stromal cell sheets. METHODS: Bone marrow stromal cell sheets (prepared from 7-week-old rat femurs) were cultured under four different hypoxic conditions. Sheets with the highest angiogenic potential, determined by an in vitro pilot study, were injected into subcutaneous layers of the rat dorsum (bone marrow stromal cell sheet group). A control group (phosphate-buffered saline only) was included. On day 2 after injection, caudally based random-pattern skin flaps (12 × 3 cm) were elevated. On day 7 after elevation, surviving skin flap areas were measured. Skin samples were harvested from each flap and gene expression levels of vascular endothelial growth factor and basic fibroblast growth factor were measured by quantitative real-time polymerase chain reaction. RESULTS: Skin flap survival area (71.6 ± 2.3 percent versus 51.5 ± 3.3 percent) and levels of vascular endothelial growth factor and basic fibroblast growth factor were significantly higher in the bone marrow stromal cell sheet group than in the control group (p < 0.05). CONCLUSIONS: Implantation of bone marrow stromal cell sheets increased the survival area of random-pattern skin flaps. Expression of angiogenic factors may have contributed to the increased flap survival.