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ABSTRACT: Autogenic bone graft is the first choice for managing bone defects. However, donor site-associated morbidity and limited bone volume are constraints in clinical applications. Allografts can provide sufficient amounts for bone defects but have a high risk of infection. Bone substitute composed of hydroxyapatite (HA) is an alternative material for avoiding the aforementioned risks. Sintered bovine bone is a naturally occurring HA that has been proved to have excellent bioactivity for inducing osteoblastic expression and new bone formation in animal studies. The objective of this study was to evaluate the interactions between the tissue and the bone substitute composed of HA (sintered from bovine bone) in the human body.
From 2003 to 2005, a total of 33 patients were enrolled to receive the sintered bovine HA as a bone substitute. Inclusion criteria were fractures with bony defects, benign bone tumors with a cavity, and spinal fusions. Bone healing was monitored by a series of radiographs, and bone microstructure was checked by scanning electron microscopy (SEM) and von Kossa staining.
In 81.8% (27/33) of cases, significant fusion mass formation was visible in the radiographs after 6-12 months. New bone formation on the surface of the sintered bovine HA was seen under microscopic observation. Tight bonding between the interface of the bone and the sintered bovine HA was shown with SEM/energy-dispersive spectroscopy and von Kossa staining.
Sintered bovine HA is a suitable material as a bone substitute to provide bone growth and promote bone healing.
Journal of Orthopaedic Science 03/2010; 15(2):223-32. · 0.84 Impact Factor
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ABSTRACT: Severe glenoid bone loss in recurrent anterior glenohumeral instability is rare and difficult to treat.
The authors present a surgical technique using allogeneic bone grafting for open anatomic glenoid reconstruction in addition to the capsular shift procedure.
Case series; Level of evidence, 4.
Nine consecutive patients with a history of recurrent anterior shoulder instability underwent reconstruction of large bony glenoid erosion with a femoral head allograft combined with an anteroinferior capsular shift procedure. Preoperative computed tomographic and arthroscopic evaluation was performed to confirm a > or =120 degrees osseous defect of the anteroinferior quadrant of the glenoid cavity, which had an "inverted-pear" appearance. Patients were followed for at least 4.5 years (range, 4.5-14). Serial postoperative radiographs were evaluated. Functional outcomes were assessed using Rowe scores.
All grafts showed bony union within 6 months after surgery. The mean Rowe score improved to 84 from a preoperative score of 24. The mean loss of external rotation was 7 degrees compared with the normal shoulder. One subluxation and 1 dislocation occurred after grand mal seizures during follow-up. These 2 patients regained shoulder stability after closed reduction. The remaining patients did not report recurrent instability. All patients resumed daily activities without restricted motion.
This technique for open reconstruction is viable for the treatment of recurrent anterior glenohumeral instability with large bony glenoid erosion.
The American journal of sports medicine 05/2009; 37(9):1792-7. · 3.61 Impact Factor
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ABSTRACT: This study was designed to derive the theoretical formulae to predict the pullout strength of pedicle screws with an inconstant outer and/or inner diameter distribution (conical screws). For the transpedicular fixation, one of the failure modes is the screw loosening from the vertebral bone. Hence, various kinds of pedicle screws have been evaluated to measure the pullout strength using synthetic and cadaveric bone as specimens. In the literature, the Chapman's formula has been widely proposed to predict the pullout strength of screws with constant outer and inner diameters (cylindrical screws).
This study formulated the pullout strength of the conical and cylindrical screws as the functions of material, screw, and surgery factors. The predicted pullout strength of each screw was compared to the experimentally measured data. Synthetic bones were used to standardize the material properties of the specimen and provide observation of the loosening mechanism of the bone/screw construct.
The predicted data from the new formulae were better correlated with the mean pullout strength of both the cylindrical and conical screws within an average error of 5.0% and R2 = 0.93. On the other hand, the average error and R2 value of the literature formula were as high as -32.3% and -0.26, respectively.
The pullout strength of the pedicle screws was the functions of bone strength, screw design, and pilot hole. The close correlation between the measured and predicted pullout strength validated the value of the new formulae, so as avoid repeating experimental tests.
BMC Musculoskeletal Disorders 05/2009; 10:44. · 1.58 Impact Factor
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ABSTRACT: We aimed to establish an animal model to investigate primary osteoarthritis of the lumbar facet joints after collagenase injection in rats and its effects on chondrocyte apoptosis. We hypothesized that osteoarthritic-like changes would be induced by collagenase injection and that apoptosis of chondrocytes would increase. Collagenase (1, 10, or 50 U) or saline (control) was injected into the lumbar facet joints. The histology and histochemistry of cartilage, synovium, and subchondral bone were examined at 1, 3, and 6 weeks after surgery. Apoptotic cells induced by 1 U of collagenase were quantified using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay. Degeneration of the cartilage and changes to the synovium and subchondral bone were dependent on both the doses of collagenase and the time after surgery. There were significantly more apoptotic chondrocytes in collagenase-treated joints than in control (P < 0.001 at 1 and 3 weeks and P < 0.05 at 6 weeks). Thus, lumbar facet joints subjected to collagenase developed osteoarthritic-like changes that could be quantified and compared. This model provides a useful tool for further study on the effects of compounds that have the potential to inhibit enzyme-associated damage to cartilage.
European Spine Journal 05/2008; 17(5):734-42. · 1.97 Impact Factor
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The Journal of trauma 04/2008; 67(1):E5-7. · 2.48 Impact Factor
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ABSTRACT: Dislocation of a hip prosthesis is a common complication. In usual cases of hip prosthesis dislocation, the prosthetic femoral head comes out from either the natural acetabular cavity in a bipolar hemiarthroplasty or the prosthetic acetabulum in a total hip arthroplasty. Only a few cases of bipolar hip prosthesis dislocation due to dissociation between the polyethylene and inner head of the prosthesis have been reported. We describe a rare case of disassembly of the inner head from the bipolar outer prosthesis in an osteoarthritic acetabulum. A 72-year-old woman had undergone bipolar hemiarthroplasty due to fracture of the left femoral neck about 10 years previously. Recently, she sustained an injury after falling from a chair, and examinations revealed an unusual disassembly-dislocation of the bipolar hip prosthesis. We classified this failure in our patient as a type II failure, representing extreme varus position of the outer head in the acetabulum, dislocation of the inner head from the outer head, and a detached locking ring around the stem neck. This mechanism of failure as shown in our patient rarely occurs in the bipolar prosthesis of the self-centering system. Osteoarthritic change of the acetabulum would place the outer head in the varus position, increasing wear on the beveled rim by impinging the femoral stem neck and causing dislodgment of the inner locking ring and consequent disassembly-dislocation of the inner head.
Journal of the Formosan Medical Association 02/2008; 107(1):84-8. · 1.13 Impact Factor
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ABSTRACT: The purpose of this study was to review the correlation between the imaging studies and the histological findings in the diagnosis of this disease. We retrospectively reviewed 21 lesions in 20 patients (median age, 23.7 years old) who had been diagnosed with cavernous haemangiomas (n=11), capillary (n=6), and mixed (n=3) types. The imaging studies were obtained with plain film radiography (n=20), Tc-99 m bone scans (n=5), angiography (n=7) and magnetic resonance imaging (MRI; n=20). All the patients underwent marginal to wide excision. Based on the imaging studies, the rate of accurate prediction of intramuscular haemangioma using MRI in our study was 90%. Using the preoperative imaging studies and surgical excisions, only one (5%) local recurrence happened 2 years after marginal excision. The remaining patients were free of disease. For the avoidance of recurrence, wide excision is necessary with the help of the imaging studies, which can provide more specific information, making possible the preoperative identification of characteristic features of the tumuor.
International Orthopaedics 09/2007; 31(4):569-75. · 2.03 Impact Factor
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ABSTRACT: Posterior instrumentation through the pedicle is a common surgery. Understanding the morphometry of the pedicle and the anatomy of adjacent neural structures should help decrease the risk of postoperative complications. T1-L5 segments from 15 sets of human vertebrae were separated into individual vertebrae and the morphometric characteristics of the thoracic and lumbar spine and the safe zone of the pedicle were analyzed. T11-L5 segments from six human cadavers were dissected. Measurements were taken from the pedicle to the dura and nerve roots superiorly, inferiorly, medially, and laterally, and the transverse angles of the nerve roots were measured. Pedicles were widest in L5 and narrowest in T4 in the transverse plane, and widest in T11 or T12 and narrowest in T1 in the sagittal plane. In individual pedicle, the ranges of the safe zone width and height were 3.4-7.7 and 8.6-13.7 mm, respectively, in T1-T10; and 7.2-17.8 and 13.9-16.7 mm, respectively, in T11-L5. The transverse angle of the pedicle decreases progressively from T1 to T12, then increase from L1 to L5. In sagittal angle, the largest angle localized at T2 and the smallest at L5. The mean distances from pedicles to adjacent neural structures were greater superiorly and laterally than inferiorly and medially. The lateral distance between nerve root and the pedicle ranged from 2.4 to 9.6 mm in lumbar spine. This study provides potential safe zones for the application of through-pedicle procedures to help decrease the risk of postoperative complications.
European Spine Journal 09/2007; 16(8):1215-22. · 1.97 Impact Factor
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ABSTRACT: We report a very rare case of intraosseous ganglion cyst of the capitate in a 54-year-old female who complained of a painful right wrist mass for 1 year. Computed tomography study showed an expansile osteolytic lesion with sclerotic margin and thinning of the cortex. Combined soft tissue ganglion cyst was also noted at operation and confirmed by pathologic study. The case was treated by a new method of autogenous bone marrow and fibrin clot graft after intralesional curettage. After a 2-year follow-up, the capitate revealed complete bony union and the symptoms were relieved with good functional results.
Journal of the Chinese Medical Association 06/2007; 70(5):222-6. · 0.79 Impact Factor
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ABSTRACT: A 36-year-old man sustained posterior dislocation of left elbow joint with olecranon fracture, comminuted coronoid fracture and subluxation of proximal radioulnar joint. We reconstructed the coronoid process with autogenous iliac crest bone graft and reduced the olecranon fracture with internal fixation. In addition, we also repaired the medial collateral ligament, annular ligament and anterior capsule during the operation. He received immobilization of the left elbow for 3 weeks after surgery and started range of motion exercises. The radiographic bone union was found 2 months after operation. The range of motion of the elbow was full at 12 months after operation. The latest 2-year follow-up, the functional result of the elbow was excellent.
Archives of Orthopaedic and Trauma Surgery 02/2007; 127(1):33-7. · 1.37 Impact Factor
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ABSTRACT: Although spontaneous rupture of the extensor tendon of the knee is more likely to occur in uremic patients with secondary hyperparathyroidism, simultaneous ruptures of bilateral knee extensor tendons is a rarely reported condition. We describe a 30-year-old man with uremia who underwent subtotal parathyroidectomy because of secondary hyperparathyroidism with very high serum parathyroid hormone (PTH) level (1940.4 pg/mL). Two weeks later, he complained of a sharp pain in both knees without trauma when he walked downstairs with his left knee forward and right knee behind. Spontaneous simultaneous ruptures of the right patellar tendon and the left quadriceps tendon were diagnosed and surgically repaired. The mechanism of spontaneous tendon rupture in uremic patients with secondary hyperparathyroidism seems to be related to high PTH level which results in osteolytic bone resorption at the tendon insertion site. Early surgical repair, control of secondary hyperparathyroidism, early use of vitamin D analogs, and total parathyroidectomy with or without autotransplantation of part of the parathyroid gland, can treat and prevent tendon rupture or re-rupture with satisfactory results.
Journal of the Formosan Medical Association 12/2006; 105(11):941-5. · 1.13 Impact Factor
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Clinical Journal of Sport Medicine 08/2006; 16(4):364-5. · 2.12 Impact Factor
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ABSTRACT: Spontaneous rupture of the extensor pollicis longus (EPL) tendon has been reported in the literature. Various mechanisms have been proposed to account for this problem, but gouty infiltration is a rare mechanism. Here we report a patient with a long-standing history of gout who presented with sudden loss of interphalangeal extension of the left thumb. Spontaneous rupture of the EPL tendon caused by gout was discovered.
The successful treatment done involved surgical exploration and extensor indicis proprius tendon transfer. Postoperative thumb spica immobilization for 6 weeks was applied.
Pathology disclosed urate crystals deposited within the ruptured EPL tendon. The functional recovery is satisfactory at the 1-year follow-up.
Spontaneous rupture of the EPL tendon caused by gout is rare. Successful treatment was done with surgical management. Life-long medical follow-up to prevent a repeated acute attack can lower the risk of a large amount of tophaceous gout infiltration in tendons and may possibly prevent acute spontaneous tendon rupture.
Archives of Orthopaedic and Trauma Surgery 06/2005; 125(4):281-4. · 1.37 Impact Factor
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ABSTRACT: The best way to apply the pretension force to the soft tissue graft during anterior cruciate ligament (ACL) reconstruction remains controversial. We compared manual, intra-, and extra-articular pretension techniques and determined the magnitude of displacement of the femur-graft-tibia complex in response to repetitive loading.
A biomechanical-controlled study.
Fresh porcine knees and profundus digital flexor tendons of hind limbs were used. Specimens were divided into 3 groups. Group A (manual pretension, n = 9) consisted of grafts that were pretensioned only by a maximal manual pull before final fixation on the tibial side. Group B (extra-articular pretension, n = 9) consisted of grafts that were pretensioned using a commercial tensiometer at 89 N for 15 minutes on the tendon preparation board, followed by pulling using maximal manual force before final fixation. Group C (intra-articular pretension, n = 9) consisted of grafts that were fastened on the femoral side first and then underwent application of a pretension force at 89 N for 5 minutes before final fixation on the tibial side. These femur-graft-tibia complexes from the 3 groups were loaded from 0 to 150 N at a frequency of 1 Hz for 1,000 cycles and then underwent a tensile load-to-failure test at a rate of 150 mm/min.
The displacement of the femur-graft-tibial complex in response to cyclic loading for group C (5.4 +/- 0.3 mm) was significantly lower than those for groups A (12.5 +/- 1.1 mm) and B (8.8 +/- 0.8 mm) (P < .001). The fixation stiffness of group C (47.9 +/- 17.6 N/mm) was significantly greater than that of group A (32.5 +/- 9.7 N/mm) (P < .05) but not significantly different from that of group B (53.1 +/- 9.1 N/mm). The ultimate failure load in each group was not significantly different.
Intra-articular pretension of the graft before final fixation can significantly minimize graft elongation at time 0 compared with manual and extra-articular pretension.
Intra-articular or in vivo pretension of the graft using instruments may minimize the graft elongation in the early period of rehabilitation after ACL reconstruction.
Arthroscopy The Journal of Arthroscopic and Related Surgery 06/2005; 21(5):540-6. · 3.02 Impact Factor
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ABSTRACT: Stress fractures are a common injury in military recruits in the lower extremities, but are rare in the upper limbs. The locations of reported stress fractures occurring in the upper extremities are mainly in the ulna and olecranon. We report on two cases of mid-ulnar stress fractures in a team of honor guards following rifle drill training from excessive weight lifting, repetitive pronation of the forearm, and a sudden increase in the training load. According to the report, some readjustment must be made in the training protocol for military recruits. Stress fractures are also being recognized as a prevalent problem in the upper body.
Military medicine 11/2004; 169(10):839-41. · 0.92 Impact Factor
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ABSTRACT: The fracture of the cuboid in children is rarely diagnosed and has probably been underreported for nondisplaced fractures. The diagnosis is often missed, and overlooked cuboid fracture can lead to severe alterations in foot mechanics and function. This case report involves a displaced compression fracture of the left cuboid in a 9-year-old girl after a fall from a height, which was treated by open reduction, bone graft, internal fixation with pins, and plaster splint immobilization. Follow-up examination 2 years after the injury revealed good bone union and a very good functional result.
The Foot and Ankle Online Journal 07/2004; 25(6):423-5. · 1.22 Impact Factor
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ABSTRACT: Eighteen symptomatic advanced-stage osteochondritis dissecans (OCD) of the talus (Berndt and Harty stages III 7 and IV 11) in 17 patients were treated with multiple autogenous osteochondral cylindrical grafts. The mean time of follow-up was 36 months (range, 25-49). The average age at surgery was 22.7 years (range, 19-34). The mean size of defect of OCD was 13.6 mm x 7.2 mm. Two or three osteochondral grafts (6 or 7 mm in diameter and 15-20 mm in length) were harvested from the superomedial margin of the ipsilateral knee. A partial osteotomy of the medial malleolus or osteotomy of the distal lateral tibia was performed for all cases. Being evaluated by the Freiburg ankle score, 16 of 18 ankles (88.8%) had excellent and two (11.8%) had good results. "Second-look" arthroscopy of 16 ankles revealed consistency of the osteochondral grafts and congruity between grafts and native cartilage in 14 (87.5%), and a softening or fissuring of the osteochondral graft in two. Our results showed that this procedure provided an effective treatment for a symptomatic advanced-stage OCD of the talus.
The Foot and Ankle Online Journal 12/2003; 24(11):815-22. · 1.22 Impact Factor
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ABSTRACT: Two patients experiencing knee stiffness on extension subsequent to total knee arthroplasties (TKAs) are reported on in this paper. The use of an oversized femoral component is suggested as the main cause of the stiffness. Revision surgery using a smaller femoral component and resecting more bone from the posterior aspect of the distal femur than during initial TKA surgery was performed to expand the joint's flexion gap without affecting joint stability on extension. This procedure appeared to solve the pre-existing limitation in knee flexion experienced by both patients subsequent to the first TKA. This complication appears to be rarely referred to in the literature: we report on 2 such cases in this paper. The range of motion in the first case was from 5 degrees to 33 degrees before revision surgery. After revision, the range of motion improved to 0 degrees /90 degrees. The second case improved from 0 degrees /45 degrees to 0 degrees /110 degrees.
The Journal of Arthroplasty 10/2003; 18(6):804-8. · 2.38 Impact Factor
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ABSTRACT: A newly designed spinal implant was tested to evaluate multicycle stiffness and fatigue resistance.
To investigate the effect of different materials, connecting plate, and pedicle screw design on the mechanical performance of the spinal implant.
The addition of cross-linkages did not significantly increase implant compression/flexion stiffness, but accelerated fatigue failure at the rod junctions. Both Ti-6Al-4V spinal implants and the 316L stainless-steel counterparts have been used extensively for clinical cases; however, design factors establishing the proposed superiority of the Ti-6Al-4V implant for fatigue resistance have not, as yet, been extensively studied.
Twenty implants with connecting plates (two materials by two screw designs by five implants) and five implants without connecting plates were assembled to UHMWPE blocks and cyclically loaded from 60 N to 600 N at a frequency of 5 Hz.
Failure sites for the tested prototypes were at the cephalic screw hubs or rod-plate junctions. All Ti-6Al-4V implants demonstrated reduced stiffness compared to the structurally identical 316L analogs. The use of connecting plates raised the stiffness of the 316L prototypes without cross-links. However, elimination of the connecting plate avoided stress concentration at the rod/plate junctions and increased fatigue life. The Ti-6Al-4V new system with the minimal notch effect at the screw hubs achieved greater fatigue resistance than its 316L counterpart. By contrast, enlargement of the inner-hub diameter resulted in greater gains for fatigue resistance than for stiffness, especially for Ti-6Al-4V variants.
Although Ti-6Al-4V was superior to 316L for endurance-limit properties, structural design of the Ti-6Al-4V implant dramatically affects fatigue resistance. This may explain the differences between existing studies and the current report, comparing fatigue life for implants made from these two materials. Our results reveal that Ti-6Al-4V must be carefully treated because of sensitivity to notch, with special consideration given to screw-hub design.
Spine 06/2003; 28(9):881-6; discussion 887. · 2.08 Impact Factor
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ABSTRACT: We report a rare complication of posterior dislocation of a cruciate-retaining total knee arthroplasty following an acute bacterial infection. The mechanism of dislocation proved to be septic loosening of the femoral component and a tear of the posterior cruciate ligament near to the femoral insertion site. The tear arose during the treatment of acute septic arthritis following total knee arthroplasty when the patient attempted full weight-bearing with the affected limb in a semiflexion position and twisted the knee.
Successful treatment was provided with subsequent surgical debridement, removal of the loosened prosthesis, the application of systemic antibiotics, and a revision total knee arthroplasty utilizing a posteriorly stabilized prosthesis after adequate control of the infection.
Soft-tissue protection from full weight-bearing of the knee during the treatment of an acute infection following total knee arthroplasty and timely removal of the loosened total knee prosthesis are recommended in order to prevent such a complication.
Archives of Orthopaedic and Trauma Surgery 05/2003; 123(2-3):121-4. · 1.37 Impact Factor
