Michael Blauth

Late results of thoracolumbar fractures after posterior instrumentation and transpedicular bone grafting

Study Design. A retrospective clinical study was performed. Objective. To study clinical and radiologic late results after posterior stabilization of thoracolumbar fractures with internal fixator and interbody fusion via transpedicular bone grafting. Summary of Background Data. The posterior approach, using an internal fixator, is a standard procedure for stabilizing the injured thoracolumbar spine. Transpedicular bone grafting was invented by Daniaux in 1986 for achieving an interbody fusion. Pedicle screw fixation with additional transpedicular fusion has remained controversial because of inconsistent reports and a lack of late results. Methods. Between January 1989 and July 1992, 76 patients with thoracolumbar fractures were operatively treated, and after a mean of more than 3 years, 56 of 62 patients (90%) still alive who had their implants removed were examined. Results. According to the Magerl classification, 33 patients sustained Type A, 13 Type B, and 10 Type C fractures. Three patients with incomplete paraplegia returned to normal. In one case of complete paraplegia, no change occurred. The mean operative time was 3 hours. In this study, two complications (3.6%) were observed: one iatrogenic vertebral arch fracture without consequences and one deep infection. Compared with the preoperative status, follow-up examinations demonstrated permanent physical and social sequelae: The percentage of individuals able to do physical labor was reduced by half (22 to 11 patients), whereas the share of unemployed or retired patients doubled (4 to 8 patients). At the time of follow-up examination, only 21 of 42 patients continued in sports. The assessment of reported problems and functional outcome with the Hannover spine score reflected a significant difference between the status before injury (96.6/100 points) and at the time of follow-up evaluation (71.4/100 points) (P < 0.001). The radiographic assessment in the lateral plane (Cobb technique) demonstrated a significant (P < 0.001) mean restoration from an initial angle of −15.6° (kyphosis) to +0.4°(lordosis). Serial postoperative radiographicfollow-up assessment showed progressive loss of correction. At follow-up examination, a mean difference from the postoperative angle of 10.1° was found (P < 0.001). Compared with the preoperative deformity, a mean improvement of 6.1° (average, −9.7°) at follow-up examination was noted. The addition of transpedicular cancellous bone grafting did not decrease the loss of correction. Computed tomography scans after implant removal were performed in nine cases: Only three of nine patients showed evidence of intervertebral fusion. No correlation could be found between the Magerl classification and radiographic outcome. However, the preoperative wedge angle of the vertebral body correlated significantly with the postoperative loss of reduction. Conclusions. Because of the disappointing results from this study, the authors cannot recommend the additional transpedicular cancellous bone grafting as an interbody fusion technique after posterior stabilization in cases of complete or incomplete burst injury to the vertebral body.

Evaluation of the mobility of adjacent segments after posterior thoracolumbar fixation: a biomechanical study

Abstract. An investigation was conducted into the effects of double-level T12–L2 posterior fixation on the mobility of neighboring unfused segments. The segmental mobility of adjacent segments above and below the fixation in ten cadaveric human thoracolumbar spine specimens was measured before and after fixation by biomechanical testing in flexion, extension, right lateral bending, and right rotation, and the data were compared. In flexion and extension, mobility of the segment above the double-level T12–L2 posterior fixation was significantly increased (P<0.05). In the adjacent segment below the fixation, there was no significant increased mobility after fixation for each moment applied. There is evidence that the adjacent segment above a double-level T12–L2 posterior fixation becomes more mobile, and this may lead to an accelerated degeneration in the facet joints due to increased stress at this point. This could be responsible for symptoms like low back pain after spinal surgery.

Influence of osteoporosis on fracture fixation - a systematic literature review

SummaryThe goal of our systematic literature search was to prove whether the experimentally shown influence of osteoporosis on fracture fixation could be confirmed in clinical studies. Despite significant effects in several studies, this is not supported by pooled data due to lack of accurate osteoporosis assessment and complication definitions.IntroductionThe fact that osteoporosis causes fractures is well-known; the assumption that it aggravates their orthopaedic treatment has not been proven. The goal of our systematic literature search was to find out whether the experimentally proven influence of osteoporosis on fracture fixation could be confirmed in clinical studies.MethodsA systematic electronic database search was performed identifying articles that evaluated complications after fracture fixation among patients suspected of having osteoporosis as measured by BMD or surrogates including Singh index or risk factors. To determine complications risks (relative risk within 95% confidence interval) data were pooled across studies, weighted by sample size and stratified by treatment type.ResultsTen studies out of 77 randomized controlled trials (51 hip, 23 distal radius and three proximal humerus studies) and three systematic reviews finally met eligibility criteria. Despite significant differences of the relative complication risk between osteoporotic and non-osteoporotic patients in several studies, this could not be proven in the pooled data.ConclusionsIn contrast to biomechanical evidence that local osteoporosis affects anchorage of implants, this could not be reproduced in clinical studies, due to the lack of accurate osteoporosis assessment, missing complication definitions and heterogeneous inclusion criteria in these studies. Prospective studies are required that address specifically the correlation between local bone status and the risk of fixation failure.

Complications in surgical treatment of thoracolumbar injuries.

Abstract. The range of surgical methods for operative treatment of thoracolumbar injuries, with their different ways of approach, grafts and techniques, remains wide. The authors present sources of error and specific complications based on their own experience and on the results of a multicenter study of the Spine Study Group of the German Trauma Association (DGU). A systematic overview of possible mistakes and complications is first presented in anatomical order. A detailed analysis is then presented of the complications reported in a multicenter study, carried out prospectively between 1994 and 1996, on 682 patients operated for acute traumatic injuries of the thoracolumbar spine. In 101 cases (15%) at least one complication occurred intra- or postoperatively. In 41 patients (6%) a revision was performed, and in 60 patients (9%) complications without operative revision were observed. These complications were analysed according to the chosen method of initial treatment.

Length determination in midshaft clavicle fractures: validation of measurement.

Objectives: To evaluate different methods of length determination in acute displaced midshaft clavicle fractures. Methods: To provide static conditions, 30 patients with healed midshaft clavicle fracture were investigated by comparing all measuring methods described in literature. The investigation included a standardized 15-degree tilted radiograph of the clavicle, a 15-degree up-tilted anteroposterior panorama radiograph of the shoulder girdle, and a posteroanterior thorax radiograph. The difference between both clavicles was also measured clinically with a tape. A computed tomography (CT) scan of the shoulder girdle was conducted with two-dimensional reconstructions of the CT scan serving as a reference method. Shortening was determined as proportional length difference. Clinical measuring was performed by 2 observers, and radiological analyses were performed by 4 independent investigators. Investigators were asked to perform repeated measurements to provide intraobserver data. Results: CT measurements, measurements on a posteroanterior thorax radiograph, and 15-degree up-tilted anteroposterior panorama radiograph of the shoulder girdle showed comparable repeatability. Repeatability for clinical measurements and measurements on 15-degree tilted radiographs of the clavicle were markedly lower. Agreement with CT measurements was highest for the measurements on posteroanterior thorax radiographs. Conclusion: While shortening in clavicle fractures is considered an important parameter in choosing a treatment modality, a standardized method of measurement is essential. Our results suggest determining proportional length differences by taking a posteroanterior thorax radiograph.

Standardised cement augmentation of the PFNA using a perforated blade: A new technique and preliminary clinical results. A prospective multicentre trial.

Pertrochanteric fractures are a rising major health-care problem in the elderly and their operative stabilisation techniques are still under discussion. Furthermore, complications like cut-out are reported to be high and implant failure often is associated with poor bone quality. The PFNA(®) with perforated blade offers a possibility for standardised cement augmentation using a polymethylmethacrylate (PMMA) cement which is injected through the perforated blade to enlarge the load-bearing surface and to diminish the stresses on the trabecular bone. The current prospective multicentre study was undertaken to evaluate the technical performance and the early clinical results of this new device. In nine European clinics, 59 patients (45 female, mean age 84.5 years) suffering from an osteoporotic pertrochanteric fracture (Arbeitsgemeinschaft für Osteosynthesefragen, AO-31) were treated with the augmented PFNA(®). Primary objectives were assessment of operative and postoperative complications, whereas activities of daily living, pain, mobility and radiologic parameters, such as cement distribution around the blade and the cortical thickness index, were secondary objectives. The mean follow-up time was 4 months where we observed callus healing in all cases. The surgical complication rate was 3.4% with no complication related to the cement augmentation. More than one-half of the patients reached their prefracture mobility level within the study period. A mean volume of 4.2ml of cement was injected. We did not find any cut-out, cut through, unexpected blade migration, implant loosening or implant breakage within the study period. Our findings lead us to conclude that the standardised cement augmentation using the perforated blade for pertrochanteric fracture fixation enhances the implant anchorage within the head-neck fragment and leads to good functional results.

The effect of in situ augmentation on implant anchorage in proximal humeral head fractures

INTRODUCTION Fracture fixation in patients suffering from osteoporosis is difficult as sufficient implant anchorage is not always possible. One method to enhance implant anchorage is implant/screw augmentation with PMMA-cement. The present study investigated the feasibility of implant augmentation with PMMA-cement to enhance implant anchorage in the proximal humerus. MATERIALS AND METHODS A simulated three part humeral head fracture was stabilised with an angular stable plating system in 12 pairs of humeri using six head screws. In the augmentation group the proximal four screws were treated with four cannulated screws, each augmented with 0.5ml of PMMA-cement, whereas the contra lateral side served as a non-augmented control. Specimens were loaded in varus-bending or axial-rotation using a cyclic loading protocol with increasing load magnitude until failure of the osteosynthesis occurred. RESULTS Augmented specimens showed a significant higher number of load cycles until failure than non-augment specimens (varus-bending: 8516 (SD 951.6) vs. 5583 (SD 2273.6), P=0.014; axial-rotation: 3316 (SD 348.8) vs. 2050 (SD 656.5), P=0.003). Non-augmented specimens showed a positive correlation of load cycles until failure and measured bone mineral density (varus-bending: r=0.893, P=0.016; axial-rotation: r=0.753, P=0.084), whereas no correlation was present in augmented specimens (varus-bending: r=0,258, P=0.621; axial-rotation r=0.127, P=0.810). CONCLUSION These findings suggest that augmentation of cannulated screws is a feasible method to enhance implant/screw anchorage in the humeral head. The improvement of screw purchase is increasing with decreasing bone mineral density.

Outcome in geriatric fracture patients and how it can be improved

Geriatric fractures are an increasing medical problem worldwide. This article wants to give an overview on the literature concerning the outcome to be expected in geriatric fracture patients and what can be done to improve it. In literature, excess mortality rates vary from 12% to 35% in the first year after a hip fracture, and also, other geriatric fractures seem to reduce the patient’s remaining lifetime. Geriatric fractures and, in particular, hip fractures constitute a major source of disability and diminished quality of life in the elderly. Age, gender, comorbid conditions, prefracture functional abilities, and fracture type have an impact on the outcome regarding ambulation, activities of daily living, and quality of life. Comprehensive orthogeriatric comanagement might improve the outcome of geriatric fracture patients. For the future, well designed, large prospective randomized controlled trials with clear outcome variables are needed to finally prove the effectiveness of existing concepts.

Biomechanical effect of bone cement augmentation on rotational stability and pull-out strength of the Proximal Femur Nail Antirotation™

INTRODUCTION After surgical treatment of osteoporotic hip fractures, complications such as implant cut-out are reported to be high and implant failure often is associated with poor bone quality. As augmentation is reported to enhance implant anchorage, the aim of our study was to investigate the effect of bone cement augmentation on the rotational stability and the pull-out resistance of the Proximal Femur Nail Antirotation™ (PFNa) blade. MATERIALS AND METHODS A total of 18 fresh-frozen femoral heads (mean age 68 years, standard deviation (SD) 8.2) were scanned with quantitative computed tomography (qCT) for bone mineral density (BMD) measurements and instrumented with a PFNa blade. Nine specimens were augmented with a mean volume of 4.4 ml Traumacem V+. After cement consolidation, the blade was rotated for 60° for the rotational test. Subsequently, the blade was extracted from the specimens. Force, torque, displacement and angle were recorded constantly. RESULTS In the rotational test, the mean maximum torque in the augmented group (17.2 Nm, SD 5.0) was significantly higher (p=0.017) than in the non-augmented group (11.7 Nm, SD 3.5). The pull-out test also yielded a significant difference (p=0.047) between the augmented (maximum pullout force: 2315.2N, SD 1060.6) and the non-augmented group (1180.4N, SD 1171.4). DISCUSSION Augmentation of femoral heads yielded a significantly superior rotational stability, as well as an enhanced pull-out resistance, compared to the non-augmented state. However, the higher the BMD of the specimens, the lower was the effect of augmentation on the rotational stability. Therefore, augmentation can be a good clinical tool to enhance implant anchorage in osteoporotic bone.

Management of hemorrhage in severe pelvic injuries.

BACKGROUND Major pelvic trauma results in high mortality. No standard technique to control pelvic hemorrhage has been identified. METHODS In this retrospective study, the clinical course of hemodynamically instable trauma patients with pelvic fractures treated according to an institutional algorithm focusing on basic radiologic diagnostics, external fixation, and early angiographic embolization was evaluated. Study variables included demographics, data on the type and extent of injury, achievement of time from admission to hemorrhage control, complications of angiography, red blood cell needs, and outcome. Standard statistical tests were used. RESULTS Of 1,476 pelvic fracture patients, 45 fulfilled the inclusion criteria. Two patients presented with severe intra-abdominal hemorrhage and underwent emergency laparotomy with pelvic packing. Forty-two patients underwent angiographic embolization before (n = 24) or after (n = 18) a computed tomography scan. Applying the clinical algorithm, pelvic hemorrhage was controlled in all but one patient who died before any intervention could be initiated (97.8%). The hourly need for red blood cell transfusions decreased during 24 hours after angiographic embolization when compared with before the procedure (3.7 +/- 3.5 vs. 0.1 +/- 0.1 U/h; p < 0.001). In patients undergoing angiographic embolization, the mean time to hemorrhage control was 163 minutes +/- 83 minutes. Hospital mortality was 26.2%. Two patients required reembolization because of hemorrhage from other than the primary bleeding site. One patient developed gluteal necrosis, and nine subsequently required renal replacement therapy. CONCLUSION Application of a clinical algorithm focusing on basic radiologic diagnostics, external fixation, and early angiographic embolization was effective and safe to rapidly control hemorrhage in hemodynamically instable trauma patients with pelvic fractures.