Cauda equina syndrome caused by the application of DuraSealTM in a microlaminectomy surgery: A case report.

BACKGROUND: The management of dural tears is important. While a massive dura can be repaired with absorbable suture lines, cerebrospinal fluid leakage can be attenuated by dural sealant when an unintended tiny durotomy occurs intraoperatively. DuraSeal is often used because it can expand to seal tears. This case emphasizes the need for caution when DuraSeal is used as high expansion can cause complications following microlaminectomy. CASE SUMMARY: A 77-year-old woman presented with L2/3 and L3/4 lateral recess stenosis. She underwent microlaminectomy, foraminal decompression, and disk height restoration using an IntraSPINE® device. A tiny incident durotomy occurred intraoperatively and was sealed using DuraSealTM. However, decreased muscle power, urinary incontinence, and absence of anal reflexes were observed postoperatively. Emergent magnetic resonance imaging revealed fluid collection causing thecal sac indentation and central canal compression. Surgical exploration revealed that the gel-like DuraSeal had entrapped the hematoma and, consequently, compressed the thecal sac and nerve roots. While we removed all DuraSealTM and exposed the nerve root, the patient's neurological function did not recover postoperatively. CONCLUSION: DuraSeal expansion must not be underestimated. Changes in neurological status require investigation for cauda equina syndrome due to expansion.

Outcomes of different minimally invasive surgical treatments for vertebral compression fractures: An observational study.

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.

Application of the IntraSPINE® interlaminar device in patients with osteoporosis and spinal stenosis: two case reports.

Osteoporosis is a rising concern in the aging population and should be considered before performing spinal surgery for older patients. Nonfusion surgery using interlaminar or interspinous devices is gradually gaining acceptance because adjacent segment disease seldom occurs postoperatively; however, other complications may occur. This report discusses the surgical outcomes of two women with osteoporosis treated by laminectomy and interlaminar device (IntraSPINE®) placement. Both patients had experienced low back pain for several years and had developed vertebral compression fractures. Several conservative treatments, including rehabilitation and local injections, were ineffective. Their bone mineral density levels were -3.0 and -2.8, indicating severe osteoporosis according to the definition established by the World Health Organization. They chose to undergo nonfusion surgery with IntraSPINE® interlaminar device placement. Their pain significantly decreased postoperatively, and their visual analog scale scores decreased from 8 to 2 and 3. Their extremity numbness and back pain resolved within 3 months. Both patients were satisfied with the surgical outcomes. No complications had occurred by 1 year postoperatively. These cases indicate that osteoporosis may not be an absolute contraindication for nonfusion spinal surgery. This report suggests a possible alternative surgical treatment for patients with osteoporosis that is refractory to conservative treatments.

Isolated distal ulnar bone metastasis from lung squamous cell carcinoma: an extremely rare case report.

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.

Rare Episode of Cement Leakage During Vesselplasty in a Case of Vertebral Compression Fracture.

BACKGROUND: Osteoporosis has become an important issue owing to the increasing elderly population. It is the most common cause of vertebral compression fracture. Conservative treatment is often ineffective, whereas surgical treatment has a vital role in compression fracture. Vesselplasty is a new surgical alternative to traditional vertebroplasty and kyphoplasty. It uses a polyethylene terephthalate balloon that functions as both a vertebral body expander and a bone cement container. We present a rare but catastrophic case of cement leakage during vesselplasty resulting in devastating neurologic compromise. This case highlights the need for awareness of vesselplasty safety and the importance of using a low-temperature bone cement. CASE DESCRIPTION: A 77-year-old woman presented with debilitating back pain owing to acute T6 compression fracture as detected by magnetic resonance imaging. Under biplanar fluoroscopy, vesselplasty using a polyethylene terephthalate balloon container was performed at the T6 vertebrae. During cement injection, balloon rupture and cement leakage occurred compromising the spinal canal. Emergent laminectomy and cement removal were performed. Paraplegia developed postoperatively. CONCLUSIONS: Though vesselplasty is claimed to be safe, cement leakage related to balloon rupture occurred in our case. Furthermore, thermal effects were difficult to observe during polymethyl methacrylate polymerization. Heat not only might cause irreversible complications but also might make the balloon rupture more easily.

Cytotoxicity of (-)-vitisin B in human leukemia cells.

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.

Clinical result of sintered bovine hydroxyapatite bone substitute: analysis of the interface reaction between tissue and bone substitute.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Sintered bovine HA is a suitable material as a bone substitute to provide bone growth and promote bone healing.

Open reconstruction of large bony glenoid erosion with allogeneic bone graft for recurrent anterior shoulder dislocation.

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 > 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. 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 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. CONCLUSION: This technique for open reconstruction is viable for the treatment of recurrent anterior glenohumeral instability with large bony glenoid erosion.

Comparison and prediction of pullout strength of conical and cylindrical pedicle screws within synthetic bone.

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 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. 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.

Disassembly and dislocation of a bipolar hip prosthesis.

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.

Intra-articular injection of collagenase induced experimental osteoarthritis of the lumbar facet joint in rats.

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.

Long-term functional outcomes after repair of rotator cuff tears correlated with atrophy of the supraspinatus muscles on magnetic resonance images.

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.

Intraosseous ganglion cyst of the capitate treated by intralesional curettage, autogenous bone marrow graft and autogenous fibrin clot graft.

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.

Imaging strategies in intramuscular haemangiomas: an analysis of 20 cases.

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.

Reconstruction of the coronoid process with iliac crest bone graft in complex fracture-dislocation of elbow.

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.

Analysis of anatomic morphometry of the pedicles and the safe zone for through-pedicle procedures in the thoracic and lumbar spine.

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.

Spontaneous rupture of the patellar and contralateral quadriceps tendons associated with secondary hyperparathyroidism in a patient receiving long-term dialysis.

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.