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Biomedical subjects

Ching-Jen Wang

Publications and source records attributed to Ching-Jen Wang.

At least 19 recordsLinked to original sources

The effects of extracorporeal shockwave on acute high-energy long bone fractures of the lower extremity.

INTRODUCTION: High-energy long bone fractures of the lower extremity are at risk of poor fracture healing and high rate of non-union. Extracorporeal shockwave was shown effective to heal non-union of long bone fracture. However, the effect of shockwave on acute fractures is unknown. The purpose of this study was to investigate the effects of shockwave on acute high-energy fractures of the lower extremity. MATERIALS AND METHODS: Between January and October 2004, 56 patients with 59 acute high-energy fractures were enrolled in this study. Patients were randomly divided into two groups with 28 patients with 28 fractures in the study group and 28 patients with 31 fractures in the control group. Both groups showed similar age, gender, type of fracture and follow-up time. Patients in the study group received open reduction and internal fixation and shockwave treatment immediately after surgery on odd-numbered days of the week, whereas, patients in the control group received open reduction and internal fixation without shockwave treatment on even-numbered days of the week. Postoperative managements were similarly performed in both groups including crutch walking with non-weight bearing on the affected limb until fracture healing shown on radiographs. The evaluation parameters included clinical assessments of pain score and weight bearing status of the affected leg and serial radiographs at 3, 6 and 12 months. The primary end-point is the rate of non-union at 12 months, and the secondary end point is the rate of fracture healing at 3, 6 and 12 months. RESULTS: At 12 months, the rate of non-union was 11% for the study group versus 20% for the control group (P < 0.001). Significantly, better rate of fracture healing was noted in the study group than the control group at 3, 6 and 12 months (P < 0.001). CONCLUSION: Extracorporeal shockwave is effective on promoting fracture healing and decreasing the rate of non-union in acute high-energy fractures of the lower extremity.

Accidental Falls↗

Femoral interference screw placement through the tibial tunnel: a novel method without graft damage.

A frequently encountered problem in endoscopic 1-incision anterior cruciate ligament (ACL) reconstruction is the difficulty involved in accurately inserting the femoral interference screw without significant and undesirable divergence between the screw and the graft when a femoral interference screw is fixed through the anteromedial portal. To minimize divergence, the authors demonstrated a modified, easy, and reproducible procedure that can be performed without causing graft injury or requiring special instrumentation. A ligament reconstruction route is created with the use of an ACL guide system. Lead graft sutures are pulled through the anteromedial portal by way of the femoral tunnel and out the anterolateral thigh first. The tendon graft is then inserted through the anteromedial portal and up into the femoral tunnel. A guidewire is introduced through the tibial tunnel into the femoral tunnel. An appropriately sized BioScrew (Linvatec, Largo, FL) is inserted, with the use of a guidewire inside the screw, through the tibial tunnel into the femoral tunnel. The graft is then retrieved through the anteromedial portal and is inserted through the tibial tunnel. Finally, the tendon graft in the tibial tunnel is similarly fixed with a BioScrew of the same size. Moreover, this novel approach is feasible for all tendon grafts (bone-patellar tendon-bone grafts, quadriceps tendon-patellar bone grafts, and hamstring tendon grafts).

Anterior Cruciate Ligament↗

Extracorporeal shockwave treatment of osteonecrosis of the femoral head in systemic lupus erythematosis.

This article reported a case of systemic lupus erythematosis (SLE) with osteonecrosis of the femoral heads (ONFH-3) successfully treated with a novel extracorporeal shockwave treatment (ESWT). The follow-up at 3 years showed that both hips had no pain on activities for daily living. Magnetic resonance image (MRI) showed substantial reduction in bone marrow edema and no further collapse of the lesions. Radiographs and MRIs showed no change in the staging of the disease. ESWT provided beneficial effects for hips affected by ONFH in patients with SLE. This novel treatment modality resulted in significant pain relief and functional improvement of the hip and reduction in bone marrow edema in our patient. It appeared that ESWT might have the potential to curtail the progression of the disease and to delay the need for total hip arthroplasty in the very young patients contracted with SLE.

Adult↗

Arthroscopic evaluation of soft tissue injuries in tibial plateau fractures: retrospective analysis of 98 cases.

PURPOSE: This investigation arthroscopically assesses the frequency of soft tissue injury in tibial plateau fracture according to the severity of fracture patterns. We hypothesized that use of arthroscopy to evaluate soft tissue injury in tibial plateau fractures would reveal a greater number of associated injuries than have previously been reported. METHODS: From March 1996 to December 2003, 98 patients with closed tibial plateau fractures were treated with arthroscopically assisted reduction and osteosynthesis, with precise diagnosis and management of associated soft tissue injuries. Arthroscopic findings for associated soft tissue injuries were recorded, and the relationship between fracture type and soft tissue injury was then analyzed. RESULTS: The frequency of associated soft tissue injury in this series was 71% (70 of 98). The menisci were injured in 57% of subjects (56 in 98), the anterior cruciate ligament (ACL) in 25% (24 of 98), the posterior cruciate ligament (PCL) in 5% (5 of 98), the lateral collateral ligament (LCL) in 3% (3 of 98), the medial collateral ligament (MCL) in 3% (3 of 98), and the peroneal nerve in 1% (1 of 98); none of the 98 patients exhibited injury to the arteries. No significant association was noted between fracture type and incidence of meniscus, PCL, LCL, MCL, artery, and nerve injury. However, significantly higher injury rates for the ACL were observed in type IV and VI fractures. CONCLUSIONS: Soft tissue injury was associated with all types of tibial plateau fracture. Menisci (peripheral tear) and ACL (bony avulsion) were the most commonly injured sites. A variety of soft tissue injuries are common with tibial plateau fracture; these can be diagnosed with the use of an arthroscope. LEVEL OF EVIDENCE: Level III, diagnostic study.

Adult↗

Arthroscopic reconstruction of the posterior cruciate ligament with use of a quadruple hamstring tendon graft with 3- to 5-year follow-up.

PURPOSE: This study prospectively evaluated 20 patients treated consecutively to determine patient outcomes, efficacy, and complication potential of arthroscopically assisted posterior cruciate ligament (PCL) reconstruction performed with hamstring tendon grafts. METHODS: Twenty patients (15 men and 5 women), each with an isolated PCL injury, underwent PCL reconstruction with hamstring tendon autograft and were enrolled in this prospective study. Average age at time of surgery was 29 years (range, 20 to 57 years). Average time from injury to surgery was 4 months (range, 3 to 12 months). Average follow-up period was 40 months (range, 36 to 50 months). Patients underwent regular follow-up after clinical and radiographic preoperative and postoperative evaluation. Follow-up examinations comprised the Lysholm Knee Score, the Tegner Activity Score, the International Knee Documentation Committee (IKDC) score, thigh muscle assessment, and radiographic evaluation. RESULTS: Mean preoperative Lysholm score for 20 knees was 63 +/- 10 (range, 48-73); mean postoperative Lysholm score was 93 +/- 9 (range, 77-100). Eighteen of 20 patients (90%) showed good or excellent results at final assessment. Mean preinjury and preoperative Tegner scores were 7 +/- 1.5 (range, 5-9) and 3 +/- 1.9 (range, 2-5), respectively; mean postoperative Tegner score for 20 knees was 6.3 +/- 2.4 (range, 4-9). In final IKDC ratings, 85% of patients (17 of 20) were assessed as normal or near normal (grade A or B). A statistically significant improvement was seen in thigh girth difference, extensor strength ratio, and flexor strength ratio before and after reconstruction at a minimum of 3 years of follow-up. CONCLUSIONS: After follow-up for longer than 36 months, analytical results showed satisfactory function after PCL reconstruction with the use of hamstring tendon autografts. We suggest that the hamstring tendon autograft is a safe, effective, and acceptable choice for PCL reconstruction, and that it affords good ligament reconstruction. LEVEL OF EVIDENCE: IV, therapeutic case series.

Adult↗

Imaging factors related to rotator cuff tear in patients with deltoid contracture.

BACKGROUND: Bony deformity and muscular malfunction around the shoulder induced by deltoid contracture may influence rotator cuff function and lead to subsequent tearing. The purpose of this study was to investigate the imaging and clinical factors related to rotator cuff tear in patients with deltoid contracture. METHODS: We retrospectively reviewed 48 shoulders in 44 patients with magnetic resonance imaging diagnosis of deltoid contracture and surgically-proven rotator cuff tear. These shoulders were subdivided into partial-thickness and full-thickness tear groups. Another 17 shoulders in 17 patients with deltoid contracture but no evident rotator cuff tear were included as the control group. The characteristics, including age, gender and imaging features, of these three groups were compared. RESULTS: Two patients who underwent initial operations for cuff tears required secondary operations for distal release of deltoid contracture. The age of patients with full-thickness tear was significantly greater than that of patients with partial-thickness tear or without tear. The winging angle of the glenoid (WAG) in the full-thickness tear group was significantly greater than that in the partial-thickness tear group. Patients with partial-thickness tear also had greater WAG than those without tear. However, WAG was not significantly correlated with the fibrotic size or age of the patient. CONCLUSION: In patients with deltoid contracture, age and WAG are associated with the development of rotator cuff tear. To prevent the occurrence of rotator cuff tear, early surgical release of deltoid contracture is highly recommended, especially in patients with greater WAG.

Adult↗

Long-term results of extracorporeal shockwave treatment for plantar fasciitis.

BACKGROUND: Extracorporeal shockwave treatment has shown mixed short-term results for plantar fasciitis. However, the long-term results are not available. HYPOTHESIS: Long-term results of shockwave treatment are comparable with short-term results. STUDY DESIGN: Randomized controlled clinical trial; Level of evidence, 1. METHODS: This prospective study consisted of 149 patients (168 heels) with an established diagnosis of chronic plantar fasciitis, including 79 patients (85 heels) in the shockwave treatment group and 70 patients (83 heels) in the control group. In the shockwave group, patients received 1500 impulses of shockwaves at 16 kV to the affected heel in a single session. Patients in the control group received conservative treatment consisting of nonsteroidal anti-inflammatory drugs, orthotics, physical therapy, an exercise program, and/or a local cortisone injection. Patients were evaluated at 60 to 72 months (shockwave group) or 34 to 64 months (control group) with a 100-point scoring system including 70 points for pain and 30 points for function. The clinical outcomes were rated as excellent, good, fair, or poor. RESULTS: Before treatment, the groups showed no significant differences in the scores for pain and function. After treatment, the shockwave group showed significantly better pain and function scores as compared with the control group. The overall results were 69.1% excellent, 13.6% good, 6.2% fair, and 11.1% poor for the shockwave group; and 0% excellent, 55% good, 36% fair, and 9% poor for the control group (P < .001). The recurrence rate was 11% (9/81 heels) for the shockwave group versus 55% (43/78 heels) for the control group (P < .001). There were no systemic or local complications or device-related problems. CONCLUSION: Extracorporeal shockwave treatment is effective and safe for patients with plantar fasciitis, with good long-term results.

Adult↗

Three-year changes in bone mineral density around the knee after a six-month course of oral alendronate following total knee arthroplasty. A prospective, randomized study.

BACKGROUND: Bone mineral density decreases after total knee arthroplasty and is believed to affect prosthetic fixation. Treatment with alendronate has been shown to improve short-term bone mineral density after total knee arthroplasty; however, the long-term effects of this therapy are unknown. The purpose of this study was to evaluate the long-term effects of a six-month course of alendronate on bone mineral density after total knee arthroplasty. METHODS: Sixty patients were randomly assigned to receive either oral alendronate at a dosage of 10 mg/day for six months or no alendronate. The bone mineral density in the distal aspect of the femur and the proximal aspect of the tibia was measured preoperatively and at six, twelve, and thirty-six months after total knee arthroplasty. RESULTS: Fifty-four patients (twenty-nine in the alendronate group and twenty-five in the control group) completed the study. The alendronate group showed significant increases in bone mineral density in the distal aspect of the femur compared with the controls at six months (+4.8% and -14.2%, respectively; p < 0.01) and twelve months (+1.6% and -11.5%, respectively; p < 0.01). No significant difference in bone mineral density was detected between the groups at thirty-six months (-3.9% and -12.2%, respectively; p = 0.08). Similar trends in bone mineral density changes were also observed in the proximal aspect of the tibia. CONCLUSIONS: A six-month course of alendronate initially increased bone mineral density at six and twelve months after total knee arthroplasty, but no difference was noted after thirty-six months. The effect of alendronate on bone mineral density after total knee arthroplasty may be limited after discontinuation of therapy.

Administration, Oral↗

Secreted frizzled-related protein 1 modulates glucocorticoid attenuation of osteogenic activities and bone mass.

Prolonged glucocorticoid treatment is known to cause osteoporosis or aseptic necrosis. Secreted frizzled-related proteins 1 (SFRP1) and low-density lipoprotein-related protein 5 (LRP5), a Wnt protein antagonist and a coreceptor, have been found to regulate skeletogenesis. Whereas recent studies have reported that excess glucocorticoid promotes bone loss, the biological role of SFRP1 and LRP5 in regulating glucocorticoid attenuation of bone formation is not fully understood. We showed that a supraphysiological level of glucocorticoid enhanced SFRP1 but not LRP5 expression of primary mesenchymal cell cultures in vitro and osteoblasts at metaphyseal trabecular endosteum and chondrocytes at calcified cartilage in vivo. Glucocorticoid augmentation of SFRP1 expression was transcriptionally mediated. The inhibitory action of glucocorticoid on osteogenic differentiation appeared to be regulated by SFRP1 mediation of beta-catenin destabilization because knocking down SFRP1 by RNA interference abrogated the supraphysiological level of glucocorticoid attenuation of osteogenesis. Recombinant human SFRP1 reduced the promoting effect of physiological level of glucocorticoid on cytosolic beta-catenin accumulation, runt-related transcription factor-2 activation, and osteogenic activities. Glucocorticoid and recombinant human SFRP1 significantly increased osteochondral cell apoptosis associated with reduced mineral density, biomechanical properties, trabecular bone volume, and midshaft cortical bone areas in rat femurs. These findings suggest that SFRP1 modulates glucocorticoid-induced bone loss. Regulation of Wnt/SFRP signal transduction can be used in the future as an alternative strategy for the prevention of glucocorticoid-induced osteoporosis.

Animals↗

Posterior cruciate ligament reconstruction using hamstring tendon graft with remnant augmentation.

Despite good early functional results, the posterior laxity of the knee is not completely eliminated after posterior cruciate ligament (PCL) reconstruction. The PCL can retain the normal tension only when the injured ligament is maintained anatomically. This article describes a technique of PCL reconstruction using hamstring tendon graft with PCL remnant augmentation. The harvested hamstring tendons were quadrupled, sized, and pretensioned before use. The PCL remnants and the synovium were preserved. Minimal debridement was performed to gain access to the insertion sites. The tibia and femoral tunnels were created with graft size-matched reamers. The graft was transfixed at 70 degrees of knee flexion with a 15-lb anterior drawer force on the proximal tibia. This surgical technique has several advantages. The hamstring graft acts as an independent PCL reconstruction and maintains the PCL remnant tension. The PCL remnants and synovium may be beneficial to ligament healing and postoperative rehabilitation. The procedure is technically feasible and cosmetically acceptable. The selection of autograft precludes the risks of allograft and artificial ligament. The short-term results are encouraging, but long-term results are needed to confirm the value of this technique for PCL reconstruction.

Arthroscopy↗

The effect of shock wave treatment at the tendon-bone interface-an histomorphological and biomechanical study in rabbits.

PURPOSE: This study was performed to investigate the effect of shock wave treatment on the healing at tendon-bone interface in rabbits. MATERIALS AND METHODS: Thirty-six New Zealand White rabbits were used in this study. The anterior cruciate ligament was excised and replaced with the long digital extensor. The right knees (study group) were treated with 500 impulses of shock waves at 14 kV, while the left knees (control group) received no shock waves. Histomorphological studies were performed in 24 rabbits at 1, 2, 4, 8, 12 and 24 weeks. Biomechanical studies were performed in 12 rabbits at 12 and 24 weeks. RESULTS: There was significantly more trabecular bone around the tendons noted in the study group compared with the control group at different time intervals after 4 weeks (P<0.05). The contacting between bone and tendon was significantly better in the study group than the control group after 8 weeks (P<0.05). The tensile strength of the tendon-bone interface was significantly higher in the study group than the control group at 24 weeks (P=0.018), whereas similar modes of graft failure were noted between the two groups. CONCLUSION: Shock wave treatment significantly improves the healing rate of the tendon-bone interface in a bone tunnel in rabbits. The effect of shock waves appears to be time-dependent.

Animals↗

Treatment for osteonecrosis of the femoral head: comparison of extracorporeal shock waves with core decompression and bone-grafting.

BACKGROUND: There is continuing controversy regarding the optimal treatment for patients with symptomatic early-stage osteonecrosis of the femoral head. We compared the results of noninvasive treatment with extracorporeal shock waves with those of core decompression and bone-grafting in similar groups of patients. METHODS: Patients with stage-I, II, or III osteonecrosis were randomly assigned to be treated either with shock waves or with core decompression and nonvascularized fibular grafting. The shock-wave group consisted of twenty-three patients (twenty-nine hips), and the surgical group consisted of twenty-five patients (twenty-eight hips). The patients in the two groups had similar demographic characteristics, duration and stage of disease, and duration of follow-up. The patients in the shock-wave group received a single treatment with 6000 impulses of shock waves at 28 kV to the affected hip. The evaluation parameters included clinical assessment of pain with a visual analog pain scale, Harris hip scores, and an assessment of activities of daily living and work capacity. Radiographic assessment was performed with serial plain radiographs and magnetic resonance imaging. RESULTS: Before treatment, the two groups had similar pain and Harris hip scores. At an average of twenty-five months after treatment, the pain and Harris hip scores in the shock-wave group were significantly improved compared with the pretreatment scores (p < 0.001). In this group, 79% of the hips were improved, 10% were unchanged, and 10% were worse. Of the hips treated with a nonvascularized fibular graft, 29% were improved, 36% were unchanged, and 36% were worse. In the shock-wave group, imaging studies showed regression of five of the thirteen lesions that had been designated as stage I or II before treatment and no regression of a stage-III lesion. Two stage-II and two stage-III lesions progressed. In the surgical group, four lesions regressed and fifteen (of the nineteen graded as stage I or II) progressed. The remaining nine lesions were unchanged. CONCLUSIONS: Extracorporeal shock-wave treatment appeared to be more effective than core decompression and nonvascularized fibular grafting in patients with early-stage osteonecrosis of the femoral head. Long-term results are needed to determine whether the effect of this novel method of treatment for osteonecrosis of the femoral head endures.

Adult↗

Factors affecting the outcome of distal realignment for patellofemoral disorders of the knee.

This study correlated the risk factors with the clinical outcome of distal realignment for patellofemoral disorders in 48 patients with 53 knees with 25 to 96 months follow-up. The indications for surgery included pain and disability due to patellofemoral disorders with failure of at least 6 months of conservative treatments. The evaluations included pain scores, Lysholm functional scores and radiographs of the knee. The overall results were satisfactory in 47 knees (88.7%) and unsatisfactory in six knees (11.3%). There was no correlation of the clinical results with age, sex, body weight and body height, preoperative pain scores and Lysholm scores. However, the clinical outcome correlated with the severity of articular damage and the correction of patellar malalignment. Error in patient selection and inadequate surgical technique were attributable to poor outcomes.

Adolescent↗

Nitric oxide donor increases osteoprotegerin production and osteoclastogenesis inhibitory activity in bone marrow stromal cells from ovariectomized rats.

Nitric oxide (NO) has emerged as a potent regulator useful in alleviating estrogen deficiency bone loss. Osteoprotegerin (OPG) and receptor activator of nuclear factor-kappaB ligand (RANKL) play important roles in regulating osteoclastogenesis. Although recent studies have reported NO donor attenuation of bone loss, the effect of NO donor on OPG and RANKL expression of osteogenic stromal cells and bone microenvironment in ovariectomized rats is not fully understood. Here, we showed that optimal NO donor treatment [2,2'-(hydroxynitrosohydrazino)bis-ethanamine; 15 microm] increased OPG, but not RANKL, levels in bone marrow stromal cells from ovariectomized rats. NO donor augmentation of OPG synthesis was transcriptionally mediated. The stimulatory action of NO donor on OPG expression appeared to be regulated by tyrosine kinase-dependent activation of Cbfa1/Runx2 binding to the OPG promoter, because cell cultures pretreated with tyrosine kinase inhibitor (herbimycin A), but not with protein kinase A inhibitor (calphostain C) or protein kinase C inhibitor [(Rp)-cAMP] significantly reduced NO-augmented Runx2 activation and OPG levels. Conditioned medium from NO donor-treated cells inhibited macrophage-colony-stimulating factor and RANKL-induced osteoclast formation of macrophage-colony-stimulating factor-dependent bone marrow macrophages. Neutralization with anti-OPG antibodies abolished the inhibitory effect of conditioned medium on osteoclastogenesis. Immunohistochemical observation also showed that 2,2'-(hydroxynitrosohydrazino)bis-ethanamine increased OPG expression of osteochondral cells located at metaphyseal endosteum and calcified cartilage of proximal femurs in ovariectomized rats. These findings suggest that NO donor can be an alternative pharmacological strategy for regulating bone resorption.

Animals↗

Shockwave stimulates oxygen radical-mediated osteogenesis of the mesenchymal cells from human umbilical cord blood.

UNLABELLED: Human umbilical cord blood (HUCB) mesenchymal progenitor cells expressed stro-1 or CD44 or CD29, and subsequently, differentiated toward osteogenic lineage. Physical shockwave treatment increased osteogenic activity of HUCB mesenchymal progenitor cells through superoxide-mediated TGF-beta1 induction. Transplantation of shockwave-treated HUCB mesenchymal progenitor cells enhanced healing of segmental femoral defect in severe combined immunodeficiency disease (SCID) mice. INTRODUCTION: Mesenchymal progenitor cells (MPCs) in the bone marrow are precursors to bone development. It remains uncertain whether MPCs are present in human umbilical cord blood (HUCB) and are capable of differentiating into osteogenic cell lineage. Extending from a model of shockwave (SW) promotion of bone marrow stromal cell differentiation toward osteoprogenitors in rats, we further investigated how physical SW mediated biological responses in regulating osteogenic differentiation of HUCB MPCs. MATERIALS AND METHODS: HUCB was subjected to SW treatment at different energy flux densities and impulses. Colony-forming units-stroma (CFU-Stroma), osteogenic activities (Cbfa1/Runx2 expression, bone alkaline phosphatase activity, and bone nodule formation), and bone formation by heterologous transplantation into SCID mice were assessed. RESULTS: Few CD34+ stem cells (1.3%) and stro-1+ cells (1.0%) were present in the freshly prepared mononuclear cells (MNCs) from HUCB. The number of stro-1+ cells, but not CD34+, increased to 72.4% in the adherent cell culture over 6 days. Stro-1+ cells co-expressed CD44 and CD29 markers and grew into CFU-Stroma that matured into bone nodules. We found that the SW treatment (0.16 mJ/mm2 energy flux density, 200 impulses) elicited superoxide production and promoted formation of CFU-Stroma, but not of hematopoietic CFU-Mix. SW also enhanced the production of transforming growth factor (TGF)-beta1, but not of interleukin (IL)-3 or granulocyte monocyte-colony stimulating factor (GM-CSF). Neutralization of TGF-beta1 significantly reduced SW-promoted CFU-Stroma formation. Superoxide scavenging by superoxide dismutase blocked SW enhancement of TGF-beta1 production and formation of CFU-Stroma. Administration of SW-treated HUCB MPCs to SCID mice with femoral segmental defects facilitated dense, bridging callus and gap closure. CONCLUSION: HUCB MPCs subjected to SW treatment is a potential source for stem cells useful in the treatment of orthopedic disorders. An optimal physical SW treatment enhanced osteogenesis through superoxide-mediated TGF-beta1 production. Physical stimulation is an alternative method for extending mesenchymal stem cells of HUCB.

Animals↗

Proximal femoral allografts for bone deficiencies in revision hip arthroplasty: a medium-term follow-up study.

Fifteen patients who had undergone hip reconstruction using a proximal femoral allograft-prosthesis composite because of failed total hip arthroplasty were reviewed retrospectively. The average length of allograft was 11 cm. The average follow-up period was 7.6 years. Ten patients retained the allograft-prosthesis construct, yielding a success rate of 67% for the procedure. The average preoperative Harris Hip Score of all patients was 21.7 points. At the latest follow-up, the average hip score for 10 patients with retained allograft-prosthesis composite was 81 points. Complications included junction nonunion (13%), allograft fracture (6.7%), loosening of acetabular component (6.7%), trochanteric escape (26.7%), allograft infection (20%), and allograft resorption (20%). Although proximal femoral allograft-prosthesis composite achieved good clinical results in most of the patients at medium-term follow-up, the late development of infection and resorption of the allograft warranted continued observation of patients who had undergone such procedures.

Adult↗

Shock wave treatment shows dose-dependent enhancement of bone mass and bone strength after fracture of the femur.

Shock wave treatment is believed to improve bone healing after fracture. The purpose of this study was to evaluate the effect of shock wave treatment on bone mass and bone strength after fracture of the femur in a rabbit model. A standardized closed fracture of the right femur was created with a three-point bending method in 24 New Zealand white rabbits. Animals were randomly divided into three groups: (1) control (no shock wave treatment), (2) low-energy (shock wave treatment at 0.18 mJ/mm2 energy flux density with 2000 impulses), and (3) high-energy (shock wave treatment at 0.47 mJ/mm2 energy flux density with 4000 impulses). Bone mass (bone mineral density (BMD), callus formation, ash and calcium contents) and bone strength (peak load, peak stress and modulus of elasticity) were assessed at 12 and 24 weeks after shock wave treatment. While the BMD values of the high-energy group were significantly higher than the control group (P = 0.021), the BMD values between the low-energy and control groups were not statistically significant (P = 0.358). The high-energy group showed significantly more callus formation (P < 0.001), higher ash content (P < 0.001) and calcium content (P = 0.003) than the control and low-energy groups. With regard to bone strength, the high-energy group showed significantly higher peak load (P = 0.012), peak stress (P = 0.015) and modulus of elasticity (P = 0.011) than the low-energy and control groups. Overall, the effect of shock wave treatment on bone mass and bone strength appears to be dose dependent in acute fracture healing in rabbits.

Animals↗

Activation of extracellular signal-regulated kinase (ERK) and p38 kinase in shock wave-promoted bone formation of segmental defect in rats.

Extracorporeal shock waves (ESW) have recently been used in bone repair. Extracellular signal-regulated kinase (ERK) and p38 kinase are found to act as important mediators for osteogenic factor and mechanical-stimulated proliferation and differentiation of bone-forming cells. A previous study reported that ESW promoted healing of segmental defects in rats by inducing bone morphogenetic proteins (Bone 32 (2003) 387-396) and stimulating osteogenic differentiation of mesenchymal stem cells. In this study, we found that ERK and p38 activation was involved in ESW-augmented bone regeneration of segmental defects. ESW treatment (0.16 mJ/mm2, 1 Hz, 500 impulses) rapidly promoted [3H]-thymidine uptake in 1 day and progressively increased alkaline phosphatase activity, collagen I, II, and osteocalcin synthesis in callus organ culture within 14 days after treatment. Results of [gamma-32P]-phosphotransferase activity assay showed that ERK and p38 in calluses were rapidly activated 1 day and 7 days after ESW treatment, respectively. Histological observation showed that segmental defects subjected to ESW treatment underwent typical bone formation (mesenchymal cell aggregation, hypertrophic cartilage, and endochondral/intramembrane ossification). Intensive bone formation coincided with evident expression of phosphorylated ERK and p38. Moreover, expression of phosphorylated ERK persisted in mesenchymal, chondral, and osteoblastic cells at newly developed bone and cartilage, and the expression of activated p38 was evident on chondral cells located at hypertrophic cartilage. Our findings suggest that mitogen-activated protein kinases (MAPK) regulate the stimulation of biophysical ESW, triggering mitogenic and osteogenic responses in the defects. ERK phosphorylation is active throughout the period of ESW-induced bone regeneration. p38 activation most likely plays an important role in signaling cartilage formation in callus.

Animals↗