Expression of macrophage elastase (MMP12) in rat tail intervertebral disc and growth plate after asymmetric loading

OBJECTIVES

The aim of this study was to examine whether asymmetric loading influences macrophage elastase (MMP12) expression in different parts of a rat tail intervertebral disc and growth plate and if MMP12 expression is correlated with the severity of the deformity.

METHODS

A wedge deformity between the ninth and tenth tail vertebrae was produced with an Ilizarov-type mini external fixator in 45 female Wistar rats, matched for their age and weight. Three groups were created according to the degree of deformity (10°, 30° and 50°). A total of 30 discs and vertebrae were evaluated immunohistochemically for immunolocalisation of MMP12 expression, and 15 discs were analysed by western blot and zymography in order to detect pro- and active MMP12.

RESULTS

No MMP12 expression was detected in the nucleus pulposus. Expression of MMP12 in the annulus progressively increased from group I to groups II and III, mainly at the concave side. Many growth plate chondrocytes expressed MMP12 in the control group, less in group I and rare in groups II and III. Changes in cell phenotype and reduction of cell number were observed, together with disorganisation of matrix microstructure similar to disc degeneration. ProMMP12 was detected at the area of 54 kDa and active MMP12 at 22 kDa.

CONCLUSIONS

Expression of MMP12 after application of asymmetric loading in a rat tail increased in the intervertebral disc but decreased in the growth plate and correlated with the degree of the deformity and the side of the wedged disc. Cite this article: Bone Joint Res 2014;3:273-9.

Percutaneous radiofrequency ablation of spinal osteoid osteoma under CT guidance

OBJECTIVE

Osteoid osteoma (OO) accounts for approximately 10-12% of all benign bone tumours and 3% of all bone tumours. Spinal involvement appears in 10-25% of all cases. The purpose of this study was to evaluate the safety and efficacy of CT-guided radiofrequency (RF) ablation in the treatment of spinal OOs and report our experience.

METHODS

13 patients suffering from spinal OO and treated at the authors' institution using CT-guided RF ablation were retrospectively evaluated. The RF probe was introduced through a 11-G Jamshidi(®) needle, and the lesion was heated at 90°C for 6 min.

RESULTS

All procedures were considered technically successful as the correct positioning of the probe was proven by CT. 11 of the 13 patients reported pain relief after RF ablation. In two cases, RF ablation was repeated 1 month after the first procedure. Pain relief was achieved in both cases after the second procedure. No recurrence was reported throughout the follow-up. No complications like skin burn, soft-tissue haematoma, infection, vessel damage or neurological deficit were reported.

CONCLUSION

This study demonstrates that CT-guided percutaneous RF ablation is a safe and effective method for the treatment of spinal OOs.

ADVANCES IN KNOWLEDGE

The data of this study support the efficacy and safety of the recently applied CT-guided percutaneous RF ablation technique for the treatment of spinal OOs.

Prediction of successful discectomy using MRI quantitation of dural sac and herniated disc dimensions

OBJECTIVE

To evaluate the ability of magnetic resonance imaging (MRI) quantitation of disc prolapse and dural sac to identify those who would benefit from discectomy.

METHODS

Thirty consecutive patients with disc herniation and leg pain who had MRI of lumbar spine and subsequently underwent discectomy were prospectively enrolled and compared with 30 controls. The anteroposterior (AP) diameter and the cross-sectional area of disc prolapse and of dural sac were measured. The ratios of AP diameters and cross-sectional areas were calculated. The measurements were correlated with the relief of symptoms based on a visual analogue scale assessment preoperatively and 1 week postoperatively.

RESULTS

All patients preoperatively had a pain score of seven or higher (mean +/- SD = 7.9 +/- 0.3) and postoperatively a score of < or = 2(mean +/- SD = 1.1 +/- 0.2). The AP diameter of disc prolapse and the ratio of AP diameters demonstrated the highest sensitivity and specificity: an AP diameter of 3.3 mm was 99% sensitive and specific and a ratio of the AP diameters of 0.37 was 100% sensitive and 99% specific.

CONCLUSION

Quantitative measurements of MRI can improve significantly the ability to identify the patients who would benefit from discectomy.

Efficacy and cost-effectiveness of cell saving blood autotransfusion in adult lumbar fusion

The objective of this study was to explore the use of cell saver blood autotransfusion in spinal surgery and to evaluate the efficacy and cost-effectiveness of cell saver blood autotransfusion during lumbar spine fusion in adults. Specific indications for the use of cell saver in adult lumbar fusion surgery have not yet been clearly determined. A total of 50 consecutive candidates for posterolateral fusion with internal fixation were prospectively randomized into either receiving perioperatively cell saving autotransfusion (Group A: 25 patients) or not (Group B: 25 patients). The use of cell saving technique did not exclude the use of allogenic blood transfusion. Surgical indications were spinal stenosis, spondylolisthesis, adolescent idiopathic scoliosis, degenerative scoliosis and fractures. Medical and financial data were recorded. A cost-analysis was performed. Patients in Group A received 880 +/- 216 mL from cell saver and 175 +/- 202 mL allogenic blood. The patients in Group B received 908 +/- 244 mL allogenic blood. Blood volumes data collected were expressed in mean +/- SD values. The cost of blood transfusion in Group A was 995 +/-euro447 per patient and 1220 +/- 269 in Group B (P < 0.05). In elective lumbar fusion blood requirements can be satisfied with the use of autotransfusion. The use of cell saver appears to be useful and cost-effective during most elective lumbar fusions.

Pancreatic cancer's initial presentation: back pain due to osteoblastic bone metastasis

Pancreatic cancer may cause osteolytic metastases, but the osteoblastic ones are extremely rare. In addition, it almost always presents with symptoms related to the invasion of the structures in the abdomen. Symptoms from bone metastases are rare and, if seen, are in the late phase of the course. We present a case of cancer of the body of the pancreas, which presented with severe back pain due to an osteoblastic lesion to L3 vertebra. Biopsy of the vertebra led to the diagnosis. Radiographs, computed tomography, magnetic resonance and scintigraphic images as well as pathology slices are shown. The present case raises the issue that pancreatic cancer, as a cause of an osteolytic bone lesion, should not be overlooked in an unknown primary investigation.

The role of radionuclides in primary musculoskeletal tumors beyond the 'bone scan'

Radionuclides represent a means of functional imaging, which is able to reflect the metabolic state of tissues. Recently developed radiotracers and older radiotracers with newer applications, imaged through single photon emission computed tomography (SPECT) and positron emission tomography (PET), can provide significant information in the diagnosis, grading, therapy response or recurrence of primary musculoskeletal tumors. The unique ability of these radiotracers to demonstrate non-invasively the efflux pump rate, which is a common reason of therapy failure, as well as the metabolic and proliferative rates of the tumors should be a powerful tool in the orthopaedic oncology in the evaluation of musculoskeletal tumors.

Sensitivity and specificity of dural sac and herniated disc dimensions in patients with low back-related leg pain

Narrow spinal canals or herniated discs can be associated with leg pain. However, it is not known whether quantitative measurements of the spinal canal or herniated disc are sensitive and specific for low back-related leg pain. The size and cross-sectional area of the dural sac and any herniated discs were measured from magnetic resonance imaging examinations of 22 asymptomatic individuals and 44 patients with sciatica. The sensitivity and specificity of these measurements were determined. In this small population of patients, a dural sac anteroposterior (AP) diameter of 10.2 mm at the L3-4, L4-5, or L5-S1 vertebral levels was 74% sensitive and 74% specific for leg pain. Based on measurements in symptomatic patients, a herniated disc with an AP diameter of approximately 3 mm was over 95% sensitive and 95% specific. However, if the AP diameters of herniated discs in symptomatic patients were compared with similar measurements in asymptomatic controls, the most sensitive and specific threshold value was 6.8 mm. These findings must be confirmed in a larger population before they are applied clinically. J. Magn. Reson. Imaging 2000;12:439-443.

Preoperative embolization of bone metastases from renal cell carcinoma

The purpose of this study was to correlate the effectiveness of preoperative embolization with the blood loss and transfusion requirement during surgery for bone metastases from renal cell carcinoma. Twenty-eight preoperative embolizations in 26 patients with renal cell carcinoma metastatic to bone were retrospectively evaluated and divided into two groups: Group A included the embolizations that resulted in complete devascularization of the lesion as defined by the post-embolization arteriograms, and group B included those with an incomplete result. The two groups were compared with regard to blood loss and transfusion requirement during surgery, by unpaired two-tailed Student's t-test. Where complete embolization was effected (group A, 10 cases), there was a mean blood loss of 535 +/- 390 ml. When a less than complete embolization was achieved (group B, 18 cases), the mean blood loss was 1.247 +/- 1.047 ml (p = 0.049). The red blood cell transfusion in group A was 1.3 +/- 1 units, whereas in group B it was 2.4 +/- 1.2 (p = 0.03). Preoperative embolization of bone metastases from renal cell carcinoma with subsequent complete devascularization leads to significant reduction of blood loss during surgery. Interventional radiologists should pursue and embolize every feeder to the metastasis, because any less than complete devascularization increases the amount of blood loss and the amount of red blood cell transfusion during surgery.

The effects of early mobilization in the healing of achilles tendon repair

Twenty-four male New Zealand rabbits underwent suture repair of a tenotomy of the left achilles tendon. The rabbits were randomized into two groups of 12 animals; in group (A), the ankle was immobilized by pinning for 35 days, while in the group (B), the ankle was immobilized for only 14 days followed by active mobilization. Following sacrifice at 35 days postoperatively, the retrieved tendons were evaluated by biomechanical testing and histologic examination. Approximately 50% of stretching occurred in the first four days; average overall elongation was 9.5+/-1.0 mm and 12.7+/-1.5 mm (p=0.102) and average stiffness recovery was 67.4+/- 2.0% and 82.9 +/- 1.9% (p=0.0004) for groups A and B respectively. Histologically both groups demonstrated traces of disorganized neo-collagen fibers at the repair site as early as the fourth day with subsequent appearance of more mature collagen. The results obtained from our study favor early mobilization of the repaired tendon, which seems to restore the functional properties of the tendons more rapidly than continuous immobilization of an identical surgical repair.

Open versus closed repair of the Achilles tendon: an experimental animal study

This experimental animal study compared the healing patterns between open and closed treatments of Achilles tendon tenotomies. Twenty-four male New Zealand rabbits underwent tenotomy of the left Achilles tendon and were randomized into two groups, treated with either open surgical repair or closed management. After the death of the animal, the retrieved tendons were submitted for biomechanical and histological testing. The total elongation of the open treatment group was 9.5+/-1.0 mm compared with 21.2+/-3.4 mm for the closed treatment group (P = 0.008), and the regain of stiffness was 67.4+/-2.0% and 48.9+/-5.3%, respectively (P = 0.132). Histological evaluation demonstrated similar healing patterns in both groups.

Biomechanical consequences of sequential plantar fascia release

Plantar fascia release has long been a mainstay in the surgical treatment of persistent heel pain, although its effects on the biomechanics of the foot are not well understood. With the use of cadaver specimens and digitized computer programs, the changes in the medial and lateral columns of the foot and in the transverse arch were evaluated after sequential sectioning of the plantar fascia. Complete release of the plantar fascia caused a severe drop in the medial and lateral columns of the foot, compared with release of only the medial third. Equinus rotation of the calcaneus and a drop in the cuboid indicate that strain of the plantar calcaneocuboid joint capsule and ligament is a likely cause of lateral midfoot pain after complete plantar fascia release.

Torsion, necrosis, and inflammation of an epiploic appendix of the large bowel: a diagnostic and therapeutic dilemma

We present the case of a young patient with abdominal pain of 3 weeks' duration and a preoperative presumptive diagnosis of acute appendicitis, diverticulitis, colon perforation, or possibly neoplasm. Even after resection of a large mass involving the right colon, the diagnosis was not confirmed until surgical pathology identified torsion, partial necrosis, and inflammation of an epiploic appendix of the right colon.