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BACKGROUND Osteoporosis with vertebral compression fractures is increasingly common in the elderly population. Cement augmentation is one of the effective surgical treatments for these patients. Currently, there are several different types of cement augmentation treatments. No studies have compared the safety and efficacy of different cement augmentation types for the treatment of such fractures; thus, we retrospectively compared vertebroplasty, balloon kyphoplasty, and kyphoplasty with SpineJack or an intravertebral expandable pillar. AIM To compare the postoperative safety and efficacy of each surgical intervention in treating vertebral compression fractures. METHODS We retrospectively analyzed 354 patients with acute vertebral compression fractures, defined as signal changes in the T1 weighted magnetic resonance imaging, and randomly divided the patients into five groups. Their visual analog scale scores for pain, kyphotic angle, average body height, rate of cement leakage, and occurrence of adjacent vertebral compression fractures were followed for 1 year. One-way analysis of variance, the post hoc Bonferroni test, and Fisher exact probability test were used for statistical analyses. RESULTS All pain scores significantly improved 12 mo postoperatively; however, there was no significant difference between the groups (P = 0.325). Kyphoplasty with SpineJack significantly reduced the kyphotic angle (P = 0.028) and restored the height of the vertebral body (P = 0.02). The rate of adjacent compression fractures was the highest in the vertebroplasty group, with a statistically significant difference according to the Fisher exact probability test (P = 0.02). The treatment with the lowest cement leakage rate cannot be identified because of the small sample size; however, kyphoplasty with SpineJack, an IVEP, and vesselplasty resulted in lower rates of cement leakage than balloon kyphoplasty and vertebroplasty. CONCLUSION Kyphoplasty with SpineJack has good outcomes in kyphotic angle reduction and body height restoration. Vertebroplasty has the highest cement leakage rate and adjacent compression fracture occurrence.

Bone metastases commonly occur in patients with lung cancer. However, metastasis from primary lung carcinoma to the bone below the knee and elbow is rarely encountered. We herein describe a man who developed an isolated distal ulnar bone metastasis originating from lung squamous cell carcinoma. A 68-year-old man presented to our orthopedic outpatient clinic for evaluation of a rapidly progressing tumor over his right wrist area. Tenderness with increased local temperature was noted, and the tumor was firm in consistency, oval-shaped, and 7 × 5 cm in size. Magnetic resonance imaging and radiographic imaging revealed an osteolytic tumor in his distal ulnar shaft. A 99m Tc-phosphate bone scan showed that this tumor was isolated and newly observed compared with the previous bone scan findings during initial diagnosis. Bone tumor biopsy confirmed metastatic squamous cell carcinoma. Segmental tumor resection with cementation was subsequently performed. This rare case report of an isolated ulnar metastasis includes detailed descriptions of the clinical, radiographic, and pathological features of the tumor.

BackgroundOsteoporosis with vertebral compression fractures is increasingly common in the elderly. As no studies have compared the safety and efficacy of surgical techniques for the treatment of such fractures, we retrospectively compared vertebroplasty, balloon kyphoplasty, and kyphoplasty with SpineJack or an intravertebral expandable pillar (IVEP). In this study, we retrospectively compared the safety and efficacy, including visual analog scale scores for pain, kyphotic angle, average body height, rate of cement leakage, and occurrence of adjacent vertebral compression fractures of each surgical intervention mentioned above at Shin-Kong Wu Ho-Su Memorial Hospital. All patients underwent surgical treatment under Dr. Wu. MethodsWe retrospectively analyzed 10 years of data of 354 patients with vertebral compression fractures, randomly dividing them into five groups. All these patients were diagnosed with fresh compression fracture, defined as signal changes on T1 phase by magnetic resonance imaging examination. Their visual analog scale scores for pain, kyphotic angle, average body height, rate of cement leakage, and occurrence of adjacent vertebral compression fractures were followed up for 1 year. ANOVA, the post hoc Bonferroni test, and Fisher’s exact probability test were used for statistical analyses.ResultsAll pain scores significantly improved 12 months postoperatively; however, there was no significant difference between the groups. Kyphoplasty with SpineJack significantly reduced the kyphotic angle, restoring the vertebral body height; adjacent compression fracture rate was highest in the vertebroplasty group (p=0.020). The method with the lowest cement leakage rate remains unidentified due to the small sample size; however, kyphoplasty with SpineJack, intravertebral expandable pillar, and vesselplasty resulted in lower rates than balloon kyphoplasty or vertebroplasty.ConclusionsVertebroplasty and kyphoplasty were excellent treatments for vertebral compression fractures, with no differences in pain relief. Kyphoplasty with SpineJack entailed a lower risk of cement extravasation, resulting in greater vertebral body height restoration and kyphotic reduction than other groups. While the safest method remains unclear, Kyphoplasty with SpineJack, intravertebral expandable pillar, and vesselplasty resulted in low rates of cement leakage. Kyphoplasty with intravertebral expandable pillar resulted in the lowest adjacent compression fracture rate.

Spinal fixation and fusion has been adopted as a common procedure in spinal surgery. However, the degeneration as a result of parafixation may produce clinically significant problems. Previous studies have already shown increased loads, mobility, and intradiscal pressure at the parafixed segments. These may hasten the degeneration and instability of the neighboring segments. However, controversy remains regarding the correlation between surgical fixation and degeneration owing to parafixation. This study tried to elucidate their relationship by analyzing the in vivo roentgenograms of the post-fusion lumbar spine to measure the motion distribution of the fixed and adjacent unfused spinal segments. In addition, a mathematical model was developed to investigate the effects of implant fixation on the kinematics and mechanics at the parafixation segments.The current radiological studies demonstrated that spinal fixation resulted in the redistribution of intersegmental mobility. The loss of flexion mobility at the fixed segments was unequally compensated for by the increased mobility at all adjacent free segments. This mechanical model can predict the redistribution patterns of mobility and stress at the parafixation segments. This redistribution depends on the fixation levels, implant rigidity, and subject predisposition. Additionally, such compensation was more marked in the tri-segmental than in the two-segment fixation, especially among patients who underwent greater spinal load.This study concluded that the increased flexural rigidity at the fixed segment leads to the compensated kinematic and mechanical demands upon the unfixed adjacent segments. Accordingly, the cumulative effects of such increased mobility and loadings on the adjacent segments could be logically postulated to be the principal causes of accelerated degeneration of the adjacent lumbar segments, both upper and lower portions, subsequent to fusion surgery.

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.

Background Severe glenoid bone loss in recurrent anterior glenohumeral instability is rare and difficult to treat. Purpose The authors present a surgical technique using allogeneic bone grafting for open anatomic glenoid reconstruction in addition to the capsular shift procedure. Study Design Case series; Level of evidence, 4. Methods 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 ≥120° 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. Results 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° 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. Conclusion This technique for open reconstruction is viable for the treatment of recurrent anterior glenohumeral instability with large bony glenoid erosion.

This in vitro biomechanical study reports on a new implant, called an intravertebral expandable pillar (IVEP). The implant is aimed at restoring the height and strength of collapsed vertebra after fracture in an osteoporotic patient. The hypothesis is that the IVEP can effectively restore the body height of the compressed vertebra and provide proper stiffness for the collapsed vertebra. Although the reported complication rate of percutaneous vertebroplasty by injection of polymethylmethacrylate (PMMA) is low, the sequelae are severe; other potential adverse effects of PMMA injection into the vertebral body include thermal necrosis of the surrounding tissue caused by a high polymerization temperature, and lack of long-term biocompatibility. We test the mechanical properties before and after fracture of 14 human cadaver lumbar vertebrae by a material testing system. The fractured vertebra was implanted with the IVEP, and its mechanical properties tested. The vertebral body height at each stage was evaluated by a digital caliper and radiographic films. After IVEP implantation, the vertebral body height restoration rate was 97.8%. The vertebral body height lost 12.7% after the same loading to create fracture. The vertebra lost half of its strength after compressed fracture, while IVEP implantation restored 86.4% of intact vertebra strength. The stiffness of intact vertebrae was significantly greater than that of untreated vertebrae after fracture and fractured vertebrae with IVEP treatment, while the stiffness of fractured vertebrae after IVEP treatment was significantly greater than that of untreated vertebrae after fracture. The bipedicularly implanted IVEP restores the initial height and strength of the vertebral body following an induced compression fracture, and could be used by a minimally invasive procedure to treat lumbar vertebra compression factures and avoid the disadvantage of using bone cement in vertebroplasty or kyphoplasty.

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.

Aim: The aim of the current study was to assess the efficacy, safety, and tolerability of lumiracoxib 200 mg once daily (o.d.) in relieving osteoarthritis (OA) knee pain in patients in China, Taiwan, and South Korea. Methods: Patients of either sex (aged ≥ 18 years) with symptomatic, primary OA of the knee for ≥ 3 months were eligible for inclusion if they had OA pain intensity of ≥ 40 mm (100 mm visual analogue scale [VAS]) in the target knee joint during the previous 24 h. Patients were required to undergo regular non-steroidal anti-inflammatory drug therapy for ≥ 6 weeks. After 3–7 days of screening, patients were randomized (1 : 1) to receive either lumiracoxib 200 mg o.d. or celecoxib 200 mg o.d. The primary efficacy comparison between the study groups was overall OA pain intensity (VAS) in the target knee after 6 weeks of treatment. Results: The mean overall OA pain intensity (VAS) in the target knee after 6 weeks decreased from 60.6 mm to 35.7 mm and 60.5 mm to 36.1 mm in the lumiracoxib and celecoxib groups, respectively. Both study groups showed similar results in terms of improvement in both patient's and physician's global assessment of disease activity and functional health status. The percentage of adverse events (AEs) in the lumiracoxib and celecoxib groups (40.3% and 37.9%, respectively) was similar, as was the proportion of treatment-related AEs (21.0% and 18.2%, respectively). Conclusions: Lumiracoxib 200 mg o.d. provided effective and well-tolerated pain relief similar to that achieved with celecoxib 200 mg o.d. in knee OA patients.

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.

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.

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.

Twenty-five patients who sustained displaced medial epicondyle fractures were treated by various surgical techniques. There were 18 males and 7 females. The mean age was 13.7 years. Surgical outcome was evaluated by use of the Elbow Assessment Score of the Japanese Orthopedic Association. Many variables that might influence the surgical outcome were considered. The results revealed no significant correlation between surgical outcome and injury mechanism, displacement, interval from injury to surgery, dislocation, fixation method, or duration of immobilization. The motion arc was moderately decreased in 1 patient treated by use of screw fixation. Moderate instability to valgus stress was noted in another patient treated by use of pin fixation (K-wires). The treatment results were all scored, and the patients with medial epicondylar fractures (displacement >5 mm) showed good to excellent results with operative treatment. Residual deformity did not compromise cosmetic appearance or clinical results. Therefore, operative treatment is a suitable choice for managing these fractures in children and adolescents.

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.

An in vitro biomechanical study compared the influence of connecting plates on construct stiffness and motion of adjacent segments. Twelve porcine lumbar spines were destabilized by laminectomy and instrumented at the L3 and L4 vertebrae by one of three transpedicular screw fixation systems: Cotrel‐Dubousset, Diapason, and a newly designed implant (FPI). The current study demonstrated that connecting plates significantly increased the construct compression and flexion stiffness and added resistance to axial rotation. The upper intact disc had greater rotational displacement than the unfixed intact spine, but the lower intact disc had more anterior translational displacement. When the construct was flexed with a 1‐second period, the upper intact disc (L2/L3) flexed much more than with a 5‐second period (P

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.

OBJECTIVE: This study was undertaken to evaluate the variation in bone density within the vertebral body and to determine the biomechanical stiffness of the screw-bone interface for different superior-inferior transpedicular screw orientations in the vertebral body. DESIGN: The stiffness of three directions of screw placement (upper, middle, and lower) were measured in two modes of loading (flexion and torsion). All screws were inserted to 80% of the distance along the path of the screw from the point of insertion to the anterior vertebral cortex. BACKGROUND: The placement of transpedicular screws within the vertebral body is a fundamental determinant the stiffness and strength of the bone-screw interface and consequently the stability of an implant construct. The bone stiffness within the pedicle and vertebra must be sufficient to resist spine forces and moments. METHODS: The stiffness of pedicle-screw fixation was tested for three different screw orientations based on the position of the screw tip in the vertebral body (upper, middle, and lower). Fixation rigidity was measured for two modes of loading (flexion and torsion). In all, eighteen individual vertebrae (L(2)-L(4)) from 6 cadaveric spine segments were examined. All the screws were inserted to 80% of the depth of the posterior to anterior vertebral cortex dimension. Quantitative bone density measurements were obtained from vertebral mid-sagittal cross sections of the additional vertebral bodies using an image analysis system to determine the distribution of bone density in the mid-sagittal plane. RESULTS: Based on area fraction measurements of cancellous bone in seventeen L1 mid-sagittal regions, highest densities were observed adjacent to the endplates (area fractions > 0.29). Regions of lowest density were found in the central portions of the vertebral bodies, above the mid-line of the body (area fractions < 0.20). In flexion, the stiffness of all three groups of screws were similar, ranging from 4.0-4.2 Nm deg(-1). In torsion the upper and middle directions were significantly more rigid than lower position (p < 0.04). CONCLUSION: Pedicle screw insertion aimed toward the superior-anterior aspect of the vertebral body, adjacent to the superior endplate provides the best overall rigidity considering both directions of loading. Screws placed in the mid-portion of the vertebral body may provide good lateral torsion rigidity, but would not be optimal for flexion stability if bone density is reduced in that region.

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.

Vitis thunbergii var. taiwaniana (VTT) is an indigenous Taiwanese wild grape and is used as a folk medicine in Taiwan. VTT is rich in polyphenols, especially quercetin and resveratrol derivatives, which were demonstrated to exhibit inhibitory activities against carcinogenesis and prevent some neurodegenerative diseases. (-)-Vitisin B is one of the resveratrol tetramers extracted from VTT. In this study, we investigated the mechanisms of (-)-vitisin B on the induction of apoptosis in human HL-60 promyelocytic leukemia cells. First, (-)-vitisin B significantly inhibited cell proliferation through inducing cell apoptosis. This effect appeared to occur in a time- and dose-dependent manner. Cell-cycle distribution was also examined, and we found that (-)-vitisin B significantly induced a sub-G1 population in a dose-dependent manner. In addition, (-)-vitisin B exhibited stronger inhibitory effects on cell proliferation than resveratrol. Second, (-)-vitisin B dose dependently induced apoptosis-related protein expressions, such as the cleavage form of caspase-3, caspase-8, caspase-9, poly(ADP ribose) polymerase, and the proapoptotic Bax protein. Third, (-)-vitisin B treatment also resulted in increases in c-Jun N-terminal kinase (JNK) phosphorylation and Fas ligand (FasL) expression. Moreover, the (-)-vitisin B-induced FasL expression and caspase-3 activation could be reversed by a JNK inhibitor. These results suggest that (-)-vitisin B-induced apoptosis of leukemia cells might be mediated through activation of JNK and Fas death-signal transduction.

Background 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). Methods 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. Results 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 R 2 = 0.93. On the other hand, the average error and R 2 value of the literature formula were as high as -32.3% and -0.26, respectively. Conclusion 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.

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.

We determined the relationship between atrophy of the supraspinatus muscle and functional outcomes in 27 patients with full-thickness rotator cuff tears who underwent arthroscopic acromioplasty and mini-open cuff repair. Before surgery, all underwent a physical examination and magnetic resonance imaging of the involved shoulder. Using image-processing software, we measured the cross-sectional area of the total supraspinatus muscle (including regions of fatty degeneration and atrophy) and of the atrophic supraspinatus muscle on sagittal oblique images obtained about 20 mm proximal to the glenoid surface. The atrophic-to-total ratio (A/T ratio) of these areas was then calculated. We assessed functional outcomes by the Constant and Murley functional score at long-term follow-up. The correlation between the A/T ratios and the functional ratings was statistically analyzed. The results demonstrated a significant positive correlation between A/T ratios of the supraspinatus muscle and functional outcomes.

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.

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.

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.

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.

STUDY DESIGN A newly designed spinal implant was tested to evaluate multicycle stiffness and fatigue resistance. OBJECTIVES To investigate the effect of different materials, connecting plate, and pedicle screw design on the mechanical performance of the spinal implant. SUMMARY OF THE BACKGROUND DATA 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.

Stress fracture of the femoral neck (SFFN) is one of the severe complications of military training. Displaced SFFN may result in avascular necrosis of the femoral head (AVNFH). The purpose of this study was to evaluate the results of surgical treatment of the displaced SFFN. Forty-two patients with displaced SFFN requiring internal fixation were treated with compression hip screw (17 cases) or multiple cancellous screws (25 cases). Forty-two patients were followed for an average of 5.6 years after operation. At the follow-up evaluation, routine radiographs were used to evaluate the fracture alignment and healing, and bone scan was used for fractures that were suspected of AVNFH. The functional assessments described by Arnold et al. were used to evaluate the functional results of surgical treatment. Seven (28%) of the 25 patients treated with multiple cancellous screws developed AVNFH during the period of follow-up. Of these seven patients, five were treated with prosthetic replacement and two treated with core decompression and bone graft. Three (17.6%) of the 17 patients treated with compression hip screw had AVNFH, and they were all treated with prosthetic replacement. The mean duration between fracture and surgery was significantly longer in patients with AVNFH (5.9 days) than in patients without AVNFH (1.9 days)(P

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.

Rigid post-traumatic kyphosis after fracture of the thoracolumbar and lumbar spine represents a failure of initial management of the injury. Kyphosis moves the center of gravity anterior. The kyphosis and instability may result in pain, deformity, and increased neurologic deficits. Management for symptomatic post-traumatic kyphosis always has presented a challenge to orthopedic surgeons.To evaluate the surgical results of one stage posterior correction for rigid symptomatic post-traumatic kyphosis of the thoracolumbar and lumbar spine.The management for post-traumatic kyphosis remains controversial. Anterior, posterior, or combined anterior and posterior procedures have been advocated by different authors and show various degrees of success.One vertebra immediately above and below the level of the deformity was instrumented posteriorly by a transpedicular system (internal fixator AO). Posterior decompression was performed by excision of the spinal process and bilateral laminectomy. With the deformed vertebra through the pedicle, the vertebral body carefully is removed around the pedicle level, approximating a wedge shape. The extent to which the deformed vertebral body should be removed is determined by the attempted correction. Correction of the deformity is achieved by manipulation of the operating table and compression of the adjacent Schanz screws above and below the lesion.Thirteen patients with post-traumatic kyphosis with symptoms of fatigue and pain caused by slow progression of kyphotic deformities received posterior decompression, correction, and stabilization as a definitive treatment. The precorrection kyphosis ranged from 30-60 degrees, with a mean of 40 degrees +/- 10.8 degrees. After correction, kyphosis was reduced to an average of 1.5 degrees +/- 3.8 degrees, with a range from -5 degrees to 5 degrees. The average angle of correction was 38.8 degrees +/- 10.4 degrees, with a range from 25 degrees to 60 degrees. Significant difference was found between pre- and post-operative kyphosis measures (P0.001). The follow-up period for all patients was 2 years, and the average kyphosis angle measured at the moment was 3.8 degrees +/- 3 degrees with a range from -3 degrees to 8 degrees. Substantial overall improvement was achieved in the 13 patients.This method provides single-stage posterior decompression, correction, and stabilization on as definitive management for post traumatic kyphosis of the thoracolumbar and lumbar spine.

From 1989 to 1996, 275 patients (245 male and 20 female) with back pain symptoms and spondylolysis of the lumbar spine were reviewed. All patients were evaluated by a protocol that included nonoperative treatment, bone scan, and pars injection. Only those whose symptoms failed nonoperative measures, showing negative bone scan and positive pars injection, were regarded as candidates for surgical management. Pars injection with Marcaine was done, and there were 93 cases with a positive response of reproducing symptoms and symptom relief. Patients then received autogenous bone grafting and internal fixation of the pars interarticularis defect. The internal fixation devices used included translaminar screws (AO 3.5 cancellous screw) for the most frequent level of L5, hook screws for levels above L4, and augmentation with wire for cases with concomitant spinal bifida occulta. The average age of the surgical group (85 male and 8 female) was 23 years (range: 19-35 years). After a follow-up averaging 30.4 months (range: 24-48 months), fusion results were 87%. Clinical results of 85 cases (91.3%) were excellent to good; 8 cases were fair; there were no poor cases. Direct repair of the pars defect by internal fixation and bone grafting was done to preserve involved motion segment and to prevent abnormal stresses at adjacent levels. These procedures seemed to be clinically effective.