Aims: Aim of this prospective clinical study was to prove whether there are clinical differences between ms VTS with interposition of an autogenic tricortical bone graft alone and a consecutive dorso-ventral procedure for A 1.2 and A 3.1 fractures of the thoracic and lumbar spine.

Materials und Methods: From 01/2002 to 12/2003 298 pat. with traumatic fractures of the thoracic and lumbar spine were treated and had a prospective clinical and radiological follow-up according to the mc-study of the DGU. For 29 pat. (14 m, 15 f; mean age 33 y) ms VTS was performed either isolated (10) or consecutive after dorsal instrumentation (19). Over the post-OP course with a follow-up of 18 mo. the pat. underwent a questionnaire concerning the morbidity at the surgical approaches, the subjective back function and the Odom-score. The osseous integration of the graft and the resulting loss of correction were investigated within the follow-ups 3, 6, 12 and 18 mo. post-OP.

Results: Concerning the anterior column 83% of the pat. had type A 3.1.1 fractures. All pat. with type B and C injuries underwent consecutive dorso-ventral instrumentation in 2 sessions. In one case revision surgery with bisegmental replacement of the affected vertebral body by a distractible cage was performed due to osteolysis of the bone graft. The other 28 pat. had no intra- or post-OP complications associated with the autogenic bone graft. At the 12 mo. follow-up osseous integration of the bone graft was observed in 28/29 in the CT-scans. The dorsal instrumentation could be removed in 8 of the 19 pat. with a dorso-ventral procedure after a mean of 12,6 mo. The measurements of the CT-scans at 18 mo. showed an average loss of correction (bisegmental) of 1,5° in the isolated ventral group and of 2,7° in the dorso-ventral group (p < 0,05). After 18 mo. Odom-score and subjective back function increased by 49% respectively 57% compared to the post-OP values (p< 0,05). Concerning the morbidity at the surgical approaches the pat. stated a pain relief of up to 73%.

Conclusions: Ms VTS with interposition of an autogenic bone graft of the iliac crest is an appropriate and meanwhile standardized minimal-invasive procedure with a low morbidity at the surgical approach. In this study a high potential for graft integration with a low amount of loss of correction could be detected in both groups (p < 0,05). For the mentioned indications the isolated ventral technique can be seen equal to the dorso-ventral procedure in 2 sessions. However the indication for an isolated ventral procedure has to be reconsidered carefully concerning increasing age and level of osteoporosis.

The objective of the study was to verify a positive effect of an additional oblique cancellous screw on the primary rotational stability of complete and incomplete high tibial closed-wedge osteotomies (8°) in ovine tibiae. Of 51 specimen 48 were employed for final results. The osteotomy site was stabilized with L-shaped plates (Allopro, Sulzer Orthopedics GmbH, Freiburg, Germany). The specimen were subdivided in 4 groups: complete (1/2) and incomplete (4/5 of the mediolateral tibial diameter in height of the horizontal sawing-jig) (3/4) osteotomies each with (1/3)) and without (2/4) an additional oblique cancellous screw. Constant axial load of 200 Newton and rotational velocity of 0,496°/sec. was applied during testing. 8 ovine specimen were tested without osteotomy or rigid fixation as a control group (5). Statistical significance (p< 0,05) was determined via the nonparametric Mann-Whitney U-test. The results were charted with SPSS (version 11.0). Correlation between objective measurement parameters and primary rotational stability of the specimen was displayed according to Pearson. The primary rotational stabilty in group 1 (intact medial cortical bone, incomplete osteotomy with additional oblique cancellous screw) was significantly higher than in groups 2, 3 and 4. In this group the resulting torsional moments in the initial part of the charted graphs were even higher than in the control group. Group 2 (incomplete osteotomy without a oblique cancellous screw) showed a significantly higher primary rotational stability compared to the groups with complete osteotomy (group 3/4). Between the groups with complete osteotomy (3/4) no significant differences in rotational stability occured. No significant correlation could be found between the objective measurement parameters of the specimen (length, weight, maximal width of the tibial plateau) and the primary rotational stability of the rigidly fixated ovine tibiae. This biomechanical in-vitro assessment showed that an intact medial cortical bone bridge has a statistically significant impact on the primary rotational stability of lateral closed-wedge osteotomies in proximal tibiae. An oblique cancellous screw through the osteotomy gap has an additional effect concerning rotational stability. In case of complete osteotomy of the proximal tibiae or due to inadequate operative technique the stabilizing effect of the medial cortical bone bridge gets lost. This results in a deterioration of rotational stability at the osteotomy site and in a sufficicantly rigid fixation is no longer guaranteed. In this case an additionally inserted oblique cancellous bone screw leads to higher resistance against rotational forces. A rigid osteosynthetic stabilization of corrective osteotomies in proximal tibiae seems a condition precedent to obtain the desired correction angle.

Shock wave treatment has been shown to induce new bone formation both under physiologic conditions and during fracture repair. Whereas various underlying molecular working mechanisms have been shown in recent studies, no study has assessed the influence of varying energy flux densities (EFD) on the amount of new bone formation in vivo. Therefore, the aim of this study was to investigate whether the effect of shock waves on bone is dependent on the applied EFD and if so, to identify the minimal dose necessary to induce new bone formation in vivo to avoid unwanted side effects of high-energy shock waves.

To this end, 30 New Zealand white rabbits were randomly divided in 5 groups and treated with extracorporeal shock waves at the distal femoral region (1,500 pulses at 1 Hz frequency each):

(a) control (sham treatment),

To investigate new bone formation, animals were injected with oxytetracycline at the days 5 to 9 after shock wave application and sacrificed on day 10. Histological sections of treated and untreated femora of all animals were examined using broad-band epifluorescent illumination and contact microradiography. The amount of new periosteal and endosteal bone was measured and signs of periosteal detachment, cortical fractures, and fragmented trabecular bone with callus were recorded.

Application of shock waves showed new bone formation beginning with 0.5 mJ/mm2 EFD and increasing with 0.9 mJ/mm2 and 1.2 mJ/mm2. The latter EFD resulted in new bone formation also on the opposite cortical bone and cortical fractures and periosteal detachment occurred. EFD of 0.35 mJ/mm2 did not lead to any new bone formation. Here for the first time a threshold level is presented for new bone formation after applying shock waves to intact bone in vivo.

We conclude that the results presented here have significant impact on further clinical applications of shock waves on bone tissue. In the present study, it is clearly demonstrated that the amount of new bone formation is directly dependent on the applied EFD. If the applied EFD is to low, no significant new bone formation will occur. If it is too high, unwanted side effects, like the formation of bone spurs in the shoulder or nerve entrapment syndromes in the elbow or feet by bony overgrowth may result.

Aims: The roentgenologic morphology of symptomatic calcified deposits of the rotator cuff can be classified according Gärtner (1993, Z Orthop Ihre Grenzgebiete 131: 461–469). This classification influences therapeutic procedures and prognosis of clinical outcome in these patients. In the present study intraoberserver-reproducibility and interobserver-reliability of Gärtner’s classification were tested. Methods: Plane radiographs of 100 patients with calcifications of the supraspinatus tendon were classified according the criteria of Gärtner by six independent observers twice within four months. Intrao-berserver-reproducibility and interobserver-reliability were calculated by means of Cohen’s-kappa-index. Results: Kappa-values of intraoberserver-reproducibility had a mean of 0.4208 (SD 0.1299), kappavalues of interobserver-reliability were 0.490 for the first and 0.474 for the second classification. Conclusions: Determination of intraoberserverreproducibility gave insufficient to satisfactory results, interobserver-reliability was sufficient. The clinical use of Gärtner’s classification to plan therapeutic procedures or to determine clinical prognosis in patients with calcifying tendinitis can be recommended only with limitations.

Aims: Little is known about effects of extracorporeal shock wave application (ESWA) on normal bone physiology. Therefore, we investigated ESWA effects on intact distal rabbit femura as an in vivo animal model. Methods: Animals received 1,500 SW pulses each of different energy ßux densities (EFD) on either left or right femur or remained untreated. ESWA effects were investigated by bone scintigraphy, MRI and histopathological examination. Results: Ten days after ESWA, local blood ßow and bone metabolism were decreased (0.5 mJ/mm2 and 0.9 mJ/mm2 EFD), but were increased 28 days after ESWA (0.9 mJ/mm2). ESWA with 0.9 mJ/mm2 EFD (but not with 0.5 mJ/mm2 ) resulted in MRI signs of soft-tissue-edema, epiperiosteal ßuid and bone marrow edema one day after ESWA, as well as in hemosiderin deposits found epiperiosteally and within the marrow cavity ten days after ESWA. Conclusions: ESWA with both 0.5 mJ/mm2 and 0.9 mJ/mm2 EFD had effects on normal bone physiology in the distal rabbit femur, with considerable damaging side effects of ESWA with 0.9 mJ/mm2 EFD on periosteal soft tissue and tissue within the bone marrow