Preliminary results for the use of knee mega-endoprosthesis in the treatment of musculoskeletal complications of haemophilia.

Complications of haemophilia in the knee region are rare and difficult to treat. Use of surgical treatments such as total knee arthroplasty cannot satisfactorily restore knee function in patients with these complications, which include massive haemophilic pseudotumour, fracture around the knee and haemarthrosis. To analyse the postoperative results of patients suffering from complications of haemophilia and treated with a knee mega-endoprosthesis, to discuss and compare this type of surgical management with other types of treatments used in similar cases. We retrospectively analyse the surgical results of patients who were treated with a knee mega-endoprosthesis for complications of haemophilia. Three severe haemophilic arthritic knees, of which two were combined with femoral condylar fractures, were treated in a one-stage surgery, and another two knees which presented with massive haemophilic pseudotumours and bony defects were treated in a two-stage operation. Mean age at time of surgery was 28.5 years old and mean follow-up time was 22.8 months; the mega-endoprosthesis surgery was successfully performed in four cases and the mean range of motion increased from 29.5° preoperatively to 96.75° postoperatively. The Knee society score function score value increased from 25 to 82.5. One knee was amputated because of uncontrollable recurrent haemorrhage. Roentgenograms did not show any signs of loosening of the prostheses. Use of Mega-endoprosthesis in the treatment of complications of haemophilia can offer patients suffering from massive pseudotumours with bone defect, severe contracture knee haemophilic arthritis and fractures around a haemophilic knee a viable treatment option.

Disc degeneration: a human cadaveric study correlating magnetic resonance imaging and quantitative discomanometry.

STUDY DESIGN: This human cadaveric study evaluated disc degeneration of the lumbar spine using magnetic resonance imaging and quantitative discomanometry. OBJECTIVE: To determine if a correlation exists between magnetic resonance imaging and quantitative discomanometry in determining disc degeneration of the lumbar spine. SUMMARY OF BACKGROUND DATA: Several studies analyzing disc degeneration of the lumbar spine have compared magnetic resonance imaging with discography and discomanometry. The reported results are conflicting. No studies exist that compare magnetic resonance imaging and quantitative discomanometry in assessing the disc degeneration of the lumbar spine. METHODS: Three fresh human cadaveric thoracolumbar spine specimens (two T11-S1 and one L1-S1) that included a total of 19 discs were used. Spines were scanned with magnetic resonance imaging, and the scans were read by a neuroradiologist. Using the quantitative discomanometry technique, discs were injected with normal saline, and pressure-volume curves were collected and quantified with six parameters: intrinsic pressure, leakage pressure, initial slope, slope from 0.0 to 0.1 mL, maximum pressure, and volume at maximum pressure. Data analysis was performed using Spearman's Rank Correlation (Rho) statistic. RESULTS: Based on the results from 19 discs, an overall good correlation between magnetic resonance imaging scores and the six quantitative discomanometry parameters was demonstrated. With exception of the volume at maximum pressure, correlation coefficients ranged between 0.61 to 0.78 with a P < 0.05. CONCLUSIONS: Magnetic resonance imaging scores and quantitative discomanometry parameters correlated well in the assessment of disc degeneration of the lumbar spine. Quantitative discomanometry may be an important technique for evaluating early disc degeneration, especially tears of the anular fibers, which may be missed on magnetic resonance imaging.

Quantitative discomanometry: technique and reproducibility in vitro.

Quantitative discomanometry is a study of intradiscal pressure and volume measurements during the injection of fluid into an endplate-disc-endplate complex. The purpose of this article was to describe the technique of quantitative discomanometry, determine the reproducibility of the injection technique in a cadaveric thoracolumbar spine, and standardize the technique for future clinical investigations. Nineteen fresh human cadaveric thoracolumbar discs were injected using quantitative discomanometry to determine: (a) the time necessary for a disc to return to a baseline pressure-volume curve, (b) the reproducibility of the technique in vitro, (c) effects of the injection approach and position of the needle in the disc, and (d) effects of the type and length of tubing as well as gauge of spinal needle. A pressure-volume curve was obtained for each disc injection. Reproducibility was measured by nine parameters obtained from each pressure-volume curve: intrinsic pressure, leakage pressure, initial slope, slope between 0-0.1 ml, slope between 1-4 ml, pressure at 2 ml, pressure at 4 ml, maximum pressure, and volume at maximum pressure. The results demonstrated that (a) the injector apparatus was reproducible, (b) the time necessary for a disc to return to a baseline pressure-volume curve was 24 h, (c) the technique using fresh human cadaveric thoracolumbar discs was reproducible, (d) the anterior and posterolateral approaches had similar results if the needle was placed into the center of the nucleus pulposus using radiographic control, and (e) the type and length of tubing, and gauge of needle did not affect the results.

Unwashed wound drainage blood. What are we giving our patients?

Wound drainage blood was collected after total joint arthroplasty was completed in 13 consecutive patients. Peripheral blood samples were collected in the recovery room and at 6 hours postoperatively for all 13 patients. A standard enzyme-linked immunosorbency assay was done to quantify tumor necrosis factor-alpha, interleukin-1 alpha, interleukin-6, and interleukin-8 levels in the samples. At 6 hours postoperatively, the levels of cytokines were elevated significantly in the peripheral and drainage blood serum. In particular, the drainage blood serum had the most dramatic increase for all cytokines, which was significant. Reinfusion of unwashed filtered postoperative wound drainage blood has been shown not to be entirely benign; pyrogenic transfusion reaction is the most commonly reported adverse effect, but hemodynamic instability with hypotension and even myocardial infarction have been reported. The cause of these adverse events has not been defined clearly, but may be secondary to the infusion of cytokines. The present study showed the presence and significant elevation of the cytokine levels in the wound drainage blood. A comprehensive review of the literature revealed that unwashed drainage blood is a relatively dilute blood product lacking normal clotting factors and having numerous other undesirable components that may mitigate against its routine use in lieu of predeposited autologous or homologous blood. This is of interest because there is evidence indicating that wound drainage blood reinfusion may be unnecessary in total joint arthroplasty when autologous blood is available. Use of drains in this surgery also may be unnecessary and has been shown to increase the amount of blood loss and the need for transfusion.

Quantitative discomanometry and acute disk injuries: an experimental model.

Quantitative discomanometry is a study of intradiscal pressure changes during quantitative injection. The purpose of this study was to determine if correlations exist between discomanometric parameters and disk injuries. Sixteen three-vertebrae porcine spine segments, with two intervening disks, were subjected to standardized high-speed trauma. The injuries were documented by a radiographic injury score (RIS), using pre- and posttrauma lateral radiographs. An anatomic injury score (AIS) also was obtained, based on an anatomic dissection and mid-sagittal plane cuts of the frozen specimen. Before the cutting, each of the disks was subjected to quantitative discomanometry, providing pressure/volume curves. Significant negative correlations were found between the RIS and the maximum pressure sustained (R = -0.60, p < 0.001), and pressure/volume slope (R = -0.60, p < 0.001). Similar relationships were found between the AIS and the maximum pressure (R = -0.71, p < 0.001), and pressure/volume slope (R = -0.63, p < 0.001). This study suggests that quantitative discomanometry can be used to quantify disk injuries. Because the intradiscal pressurization mimics the physiology with weight bearing, its use as a measure of integrity of the end-plate-annulus-end-plate enclosure might be justified.

Posterior element strength six months postinjury in the canine cervical spine.

In vivo and in vitro biomechanical studies from this research group revealed that acute differences in the range of motion of C4-C5 canine cervical spine injuries decreased over a 24-week healing period to approach control values. It could be inferred that the repair tissue replacing the injured posterior elements functionally returned the spine to normal. This study investigated the biomechanical properties of the healed tissue and the isolated adjacent posterior elements at each intervertebral level of these same specimens. Twenty-two animals underwent one of four procedures at the C4-C5 level: (a) sham procedure, (b) transection of the supra- and interspinous ligament, (c) laminectomy, or (d) laminectomy plus bilateral facetectomy of the inferior articular facets. Twenty animals survived the entire testing protocol. Twenty-four weeks after injury, destructive testing was performed on the isolated posterior elements in tension loading. The maximum load, elongation at maximum load, stiffness, and energy absorbed to the maximum load were measured. The posterior elements injured by all of the procedures behaved similarly across all experimental groups after 24 weeks of healing. A trend for decreased stiffness in the more extensive surgery groups was seen, but no statistically significant differences were found. This paralleled the results of prior in vivo and in vitro range-of-motion testing.

An anatomic basis for spinal instability: a porcine trauma model.

To determine the anatomic basis for spinal instabilities, 16 porcine cervical spine specimens were subjected to a well-defined sagittal plane trauma. The multidirectional instability of each specimen was measured before and after trauma. Detailed anatomic dissections were performed on each traumatized specimen to quantitate the extent of injury to several distinct anatomic structures and columns. Multiple regression models were constructed to determine which anatomic structures and columns correlated best with each multidirectional instability. Flexion instability correlated best with injury to the interspinous/supraspinous ligaments and the ligamentum flavum. Extension instability correlated best with anterior longitudinal ligament and pedicle injury. Axial rotation instability correlated best with anterior disc-end-plate and capsular ligament injuries, while lateral bending instability correlated best with posterior disc-end-plate injuries. Anterior column injuries correlated best with extension, axial rotation, and lateral bending instabilities, while posterior column injuries correlated best with flexion instability. Finally, individual anatomic structural injuries had higher correlations with multidirectional instabilities than did the injuries defined by the anatomic columns.

Cervical spine injury patterns in three modes of high-speed trauma: a biomechanical porcine model.

Cervical spine fractures and dislocations account for a large number of deaths and disabilities in the United States each year. More knowledge of the anatomic injuries produced by known trauma may yield practical information regarding injury mechanisms and treatment alternatives. In this experiment, 16 porcine cervical spine three-vertebrae segments were subjected to flexion-compression, extension-compression, and compression-alone trauma modes. The resultant injuries were scored by anatomic dissection. The results were analyzed for variance with trauma mode using nonparametric analysis. The three modes of trauma were found to have statistically significant differences in the degree of injury to the spine and its structural components. Extension-compression trauma produced the greatest injury scores to the whole spine and to the anterior structures. Flexion-compression trauma produced the highest posterior element injury scores. Compression trauma alone produced the lowest injury scores and no definitive pattern of anatomic injuries. The severity of anatomic injuries in this model relates most to the addition of bending moments to high-speed axial compression of the spine segment.