Overview of clinical and experimental use of hyaluronic acid in gonarthrosis]

AIM: The aim of this survey is to review the clinical and experimental background for the use of hyaluronan (HA) in the therapy of gonarthrosis. MATERIALS AND METHODS: Clinical and experimental studies were analysed following a medline literature-research. To determine the clinical efficiency of HA only randomised and controlled studies were taken into account. As a result of this analysis the current knowledge for the clinical and experimental use of HA is portrayed. RESULTS: Numerous controlled, randomised studies showed beneficial effects for pain relief and joint function after i.art.injection with HA. Placebo, NSAIDs and steroids were used as control medications. The effect of HA was significantly better compared to placebo, and similar or superior in comparison to other verums (NSAIDs, steroids). After completion of HA-therapy a long lasting effect compared to steroids was shown. Review of the literature reveals side-effect rates for HA-therapy similar to those for placebos. In various experimental studies a clear working mechanism could not be identified, especially reasons for the long lasting effects are still unknown. However, some studies showed an anti-inflammatory effect in inflamed joints and in stimulated culture-conditions. A stimulating effect of the HA-production by synoviocytes after administration of HA was shown. Further studies will have to demonstrate the cellular effects in vitro and in animal models in detail. CONCLUSION: HA is therefore classified as a "symptom slow acting drug for osteoarthritis" because a "structure-modifying (chondroprotective) effect" has not been proven yet.     

Sagittal alignment and segmental range of motion after total disc replacement of the lumbar spine

AIM: To evaluate changes in static and dynamic values, X-rays of patients who underwent total disc replacement for degenerative disc disease were analyzed. METHOD: An analysis of pre- and postoperative lateral X-rays in 22 patients with 24 total disc replacements (Prodics, Spine Solutions) was performed. The total lumbar lordosis, the segmental lordosis angle, the disc height and the range of motion in the operated level were measured. RESULTS: Postoperatively a significant increase was observed for the following parameters: the anterior (pre: 9.0 +/- 3.4 mm; post: 16.7 +/- 2.4 mm; p < 0.001) and posterior (pre: 4.4 +/- 1.3 mm; post: 8.8 +/- 1.3 mm; p < 0.001) disc height and the segmental lordosis angle (pre: 20 degrees +/- 7.2 degrees; post: 27.7 degrees +/- 7.4 degrees; p < 0.001). Statistically no significant changes could be observed postoperatively for the total lumbar lordosis (pre: 56.2 degrees +/- 10.7 degrees; post: 58.6 degrees +/- 9.3 degrees; p = 0.196) and the range of motion (pre: 5.0 degrees +/- 4.0 degrees; post: 5.9 degrees +/- 3.5 degrees; p = 0.293). CONCLUSION: Total disc replacement for degenerative disc disease of the lumbar spine with the current concept does not alter the range of motion but significantly increases the disc height. The significant increase in segmental lordosis without a change in the total lumbar lordosis accounts for a change in lordosis in adjacent segments.     

Computer navigation in dorsal instrumentation of the cervical spine--an in vitro study

Transarticular C1/2 screws are widely used in posterior cervical spine instrumentation. Pedicle screws in the cervical spine remain uncommon until now. In view of improved biomechanical stability compared to lateral mass screws, pedicle screws could be used, especially for patients with poor bone quality or defects in the anterior column. Nevertheless, there are potential risks of iatrogenic damage to the spinal cord, nerve roots, or the vertebral artery related to both techniques of posterior cervical spine instrumentation. Therefore, the aim of this study was to evaluate whether C1/2 transarticular screws as well as transpedicular screws in C3 and C4 can be applied safely and with high accuracy using a computer-assisted surgery (CAS) system. C1/2 transarticular screws as well as transpedicular screws in the cervical spine can be applied safely and with high accuracy using a CAS system in vitro. Therefore, this technique may be used in the clinical setup due to improved accuracy and reduced radiation dose for the patient and medical staff. Nevertheless, to prevent iatrogenic damage, users should be aware of known sources of possible errors that cause inaccuracies. Small pedicles with a diameter below 4.0 mm may not be suitable for pedicle screws.     

A method to assess biochemical activity of liver cells during clinical application of extracorporeal hybrid liver support

Biochemical activity of a hybrid liver support system based on porcine liver cells was investigated in patients suffering from acute liver failure, coma stage III-IV Patient plasma was drawn systemically and after circulation through the bioreactor at four hour intervals. A method is used that takes into account the rate of plasma flow and the differences in plasma concentration systemically and after circulation through the liver support system to determine the net release or uptake of metabolites such as ammonia, urea and glucose. Urea release (mean 2.28+/-0.37 micromol/h/g cells) and ammonia uptake (mean 0.17+/-0.11 micromol/h/g cells) was seen during treatment, an active role of the system in glucose metabolism was observed. All patients were bridged successfully to liver transplantation.     

Outcome predictors of intertrochanteric osteotomy in avascular necrosis of the hip]

PURPOSE OF THE STUDY: To find radiographic predictors for the clinical outcome in patients who underwent an intertrochanteric osteotomy (ITO) because of avascular necrosis of the femoral head (AVN). METHOD: Between 1985 and 1996 in 93 patients with an AVN (mean age 39,5 years +/- 8.8 y.) an ITO was performed. 83 patients (89 %) were available for follow up at an average post-op time of 84 months +/- 40.7 mon. We used the Ficat and ARCO classifications for staging of the disease. The combined necrotic angle of Kerboul was used to measure the size of the lesion. The clinical outcome was estimated using the Harrisp hip score (HHS) and the WOMAC. Survival time of the ITO was estimated using Kaplan-Meier survivorship analysis with the implantation of a hip prosthesis as endpoint. RESULTS: 27 patients (30.8 %) underwent an arthroplasty after an average time of 35.1 mon. +/- 30,4 mon. after the osteotomy. Survival rate of an ITO was 67 % after 5 y, and 46 % after 10 y. In case of a preoperative Kerboul angle > 200 degrees the survival rate of an ITO was significantly lower and the WOMAC index (3.1 +/- 2.4) significantly worse (p < 0.05) than in patients with a Kerboul angle < 200 degrees (1,8 +/- 1.8). In Ficat stage III/IV or ARCO stage IVVI the survival rate of an ITO was significantly lower when compared to stages I/II and IIII. There was no clinical difference in the HHS comparing different stages. CONCLUSION: The Kerboul angle was the best parameter to predict the clinical outcome and the survival rate of an ITO. The classifications of Ficat and ARCO were found to be a predictor for the survival rate of an ITO but not for the clinical outcome.     

Surgical treatment and prognosis factors in spinal metastases of breast cancer

AIM: The aim of this study was the evaluation of surgical therapy results and prognosis factors in patients with spinal metastases of breast cancer. METHODS: 55 patients with spinal metastases of breast cancer who were treated surgically were retrospectively evaluated. In 11 patients the cervical, in 27 patients the thoracic and in 17 patients the lumbar spine was affected. RESULTS: Postoperatively, 45 patients (81.8 %) described a reduction in pain and 5 patients (50 %) reported a neurological improvement. Perioperative complications appeared in 27 patients (49.1 %), 2 patients died. For the entire group, the mean postoperative survival was 27.2 +/- 28.6 months and the median survival 16.2 months. In patients with solitary metastasis the univariate analysis did not show a significantly longer postoperative survival than in patients with additional visceral metastases (p = 0.0659), but patients with solitary metastasis showed a significantly longer survival than those with multiple osseous and/or visceral metastases (p = 0.0325). In the univariate analysis, the classification of the primary tumour, the duration of symptoms, the localisation of the metastases, the patient's age and the kind of surgical procedure (posterior stabilising instrumentation versus combined posterior-anterior treatment with intralesional resection of the affected vertebra and vertebral body replacement) did not show a significant influence on the postoperative survival. The multivariate analysis did not show a significant prognostic influence for the potentially prognostic factors, however, solitary and multiple metastasis showed the highest statistical influence for the prognosis (p = 0.1187), followed by the classification of the primary tumour (p = 0.1243). CONCLUSION: Pain reduction and neurological improvement can be reached by a stabilisation of the diseased spinal region. Patients with spinal metastases due to breast cancer showed a relatively long postoperative median and mean survival. Therefore, the preoperative evaluation of extent of the disease and the therapy concept should be individually adapted. The surgical procedure (posterior stabilising instrumentation versus combined posterior-anterior approach with vertebrectomy and vertebral body replacement) does not significantly influence the survival.     

Prognosis, surgical therapy and progression in cervical and upper-thoracic tumor osteolysis

INTRODUCTION: This study analyzes the early and mid-term results of our modular rod-screw implant system for the posterior instrumentation of the occipito-cervical, cervical and cervico-thoracic spine (neon occipito-cervical system, Ulrich, Germany) in patients with tumor osteolysis. The prognosis of the patients was evaluated using the Tokuhashi score. METHODS: The cervical and upper thoracic spines of 14 patients (7 males, 7 females, mean age 61 years, range 40-77 years) with osteolysis due to plasmocytoma (n = 2), bronchial (n = 3), mamma (n = 4), thyroid (n = 2), esophageal (n = 1) and pancreatic (n = 1) carcinomas as well as melanoma (n = 1) were instrumentated between June 2001 and April 2004. RESULTS: A stable fixation without loosening or failure of the fixator system was achieved in all cases. No impairment of the neurological status was observed. In our cohort different prognosis scores failed to make a reliable estimate of the expected survival at the time of surgery. CONCLUSION: Posterior instrumentation of the cervical spine including the occipito-cervical and the cervico-thoracic regions with a modular angle-stable rod-screw implant system (neon) offers good stabilization and allows simultaneous decompression. Since tumor masses are predominantly located in the anterior portion of the spine, blood loss can be controlled well. In this patient collective appears difficult to estimate the time of survival by a scoring system.     

Diabetic muscle infarction-an orthopedic disease pattern?

Diabetic muscle infarction (DMI) is a largely unfamiliar disease. It affects mainly patients around 40 years of age with long-standing diabetes and concomitant end-organ complications. The symptoms represent a classic pattern of a musculoskeletal disease with muscle pain without trauma, swelling, and functional impairment. Although its short-term prognosis is good, with improvement of the symptoms over weeks or months under analgesia and rest, a high recurrence rate of up to 60% can be observed. Additionaly, the long-term survival of patients after DMI is reduced mostly due to major vascular complications.Since many diabetic patients are in orthopedic care for musculoskeletal disorders, the orthopedic surgeon should be aware of this disease to avoid unnecessary invasive diagnostic procedures and initiate suitable therapy. Furthermore, a better knowledge of the disease could lead to definite conclusions regarding its real incidence and aid in establishing new therapeutic measures for prophylaxis and better long-term survival.