Predictive value of Singh index and bone mineral density measured by quantitative computed tomography in determining the local cancellous bone quality of the proximal femur.

OBJECTIVE: The purpose of this study was to assess the predictive value of the Singh index as well as quantitative computed tomography for the in vitro local mechanical competence of the cancellous bone of the proximal femur. DESIGN: An experimental study examining the relation between mechanical properties and bone mineral density of the femoral neck determined in vitro and the clinical estimated Singh index on X-rays. BACKGROUND: Evaluation of the predictive value of the Singh index, an inexpensive and simple technique for the mechanical properties of the cancellous bone of the proximal femur. METHODS: The bone quality of the proximal femur of 34 patients undergoing total hip replacement was estimated by roentgenography using the Singh index. Bone mineral density was quantified by quantitative computed tomography using cylindrical cancellous bone biopsies harvested during the total hip replacement procedure by a new biopsy method. The mechanical properties of the bone specimens (Young's modulus, strength and maximum energy absorption E(max)) were measured by mechanical testing of the bone biopsies. RESULTS: A strong correlation of the Singh index versus material properties of cancellous bone was noted (r=0.66 for Young's modulus, r=0.73 for strength and r=0.69 for E(max), P<0.0001). The correlations of bone mineral density measured by quantitative computed tomography versus Young's modulus, strength and energy absorption E(max) were significant. Strength was predicted best (r=0.82; P<0.0001), followed by E(max) (r=0.79; P<0.0001) and Young's Modulus (r=0.73; P<0.0001). CONCLUSIONS: We conclude, that assessment of bone mineral density by quantitative computed tomography is a reliable and precise method for the estimation of cancellous bone material properties. The Singh index provides a rough estimate for the mechanical competence of the proximal femur. It is inexpensive, simply to assess and can in some cases replace the measurement of bone mineral density, notably in cases of marked decrease in bone density.

[Fractures of the upper extremity in the elderly]. / Frakturen der oberen Extremität beim alten Menschen.

PROBLEM: The primary goal in treating fractures in elderly persons is safe and rapid restoration of their functional capabilities to secure independence in everyday activities. The intention of this paper is to present an overview of treatment principles useful in this age group. METHODS: We analysed a series of 404 patients above the age of 70 years who underwent surgery for fractures of the arm between 1981 and 1997. RESULTS: Diaphyseal fractures are less frequent in this age group and their treatment does not differ significantly from principles established for younger patients. The majority of fractures of the proximal humerus and the distal radius can be treated by conservative means. Unstable fractures are frequent in the distal humerus and the olecranon requiring operative reduction and osteosynthesis. CONCLUSIONS: Preferred operative techniques in aged persons inflict minimal surgical trauma and have a low rate of complications and secondary interventions. In contrast, anatomical reconstruction has the highest priority in younger individuals.

[Therapy of para-articular hip fractures in the elderly]. / Die Therapie hüftnaher Frakturen im Alter.

UNLABELLED: Fractures of the hip in old patients are life-threatening events. A steady increase of that fracture type is likely in the near future. Surgical therapies and strategies have to consider the special requirements and problems of geriatric patients to achieve better results. They have to be designed together with new concepts of geriatric rehabilitation programmes. MATERIAL AND METHODS: In 1992 148 patients with hip fractures were treated at the department of traumatology, University Ulm. Follow-up parameters were daily activities in life pre- and postoperatively as well as mortality, type of fracture and surgical treatment. RESULTS: There were 79 femur fractures of the collum and 69 fractures of the trochanteric region. Mean age was at 81.2 and 81.9 years respectively (68 f/11 m versus 52 f/13 m). At the time point of accident 84 patients lived at home whereas the remaining stayed at a nursing home. The highest mortality was found in patients living in a nursing home (93%). The overall mortality one year following the trauma was 26%. 50% of the patients had hip prosthetic replacement, the remaining received a gliding screw, 9 patients a proximal femoral nail or lag screws (n = 6). CONCLUSION: Our results demonstrate that hip fractures in geriatric patients have a high mortality, especially in those living in a nursing home. The surgical concepts should aim to reduce that number and to allow the same daily activity of life as preoperatively. The main part in these concepts is an early start of geriatric rehabilitation. There are at least two groups. On the one hand, the active old patient who acquires his fracture during an activity. In this cases the aim must be the full rehabilitation and afterwards returning to normal environment. On the other hand there are the patients living in a nursing home who have the highest risk of injury related death. In these patients the first aim must be prevention of the accident.

[Arthroscopic stabilization of anterior shoulder instability with bioresorbable tacks]. / Die arthroskopische Stabilisation der vorderen Schulterinstabilität mit bioresorbierbaren Dübeln.

We examined 38 patients with an arthroscopic bioabsorbable tack repair for anterior shoulder instability in a prospective evaluation. The mean follow-up was 22 months (range 12 to 33). The average age was 28.4 years (range 15 to 57), the operation was performed at average of 50 months (3 to 244 months) after injury. Assessment using the Rowe score revealed excellent results in 33 and good results in 3 patients. 1 patient had a fair result and 1 had a poor result. 26 should obtained full range of motion, 11 had minor (< 10 degrees) loss of external rotation, 1 experienced greater (< 20 degrees) loss of external rotation. 3 of the 38 patients (8%) had recurrent instability, 1 patient with 2 preceding operations and atraumatic and voluntary dislocation, respectively. The recurrence rate of arthroscopic Bankart repair with bioabsorbable tacks are comparable to open Bankart procedures. Success of the procedure depends on appropriate surgical technique and suitable selection of patients with unidirectional, posttraumatic, anterior instability who are found to have well-developed ligamentous tissue.

Drug prophylaxis of deep vein thrombosis in traumatology: is there a benefit of a score in outpatients?

INTRODUCTION: Guidelines are lacking for the administration of drug prophylaxis of deep vein thrombosis (DVT) in outpatients. This study attempted to develop such a guideline in the form of a score. PATIENTS AND METHODS: In a prospective study of 731 outpatients with injury or surgery of the leg or pelvis a score was assigned based on "simulated physiological conditions" of the venous flow, including breathing, mobilization (activity of daily live), weight bearing and range of motion of joints of the lower extremities, lesions of the venous endothelium, date of injury, and localization of injury. The decision as to whether to administer drug prophylaxis of DVT was made on the basis of the patient's score. The venous system was investigated by duplex color-coded ultrasound. RESULTS: There were two false-negative findings, meaning that patients without drug prophylaxis showed a thrombotic complication. In neither of these cases had the patient been compliant with medical instructions. In the group with drug prophylaxis there were 4% DVT (n=18). CONCLUSION: Compared to previous results of 10% DVT in outpatients, our score-assisted drug prophylaxis significantly reduced the incidence of DVT. The score also makes it possible to select patients not requiring drug prophylaxis.

[Resorbable bone cements]. / Resorbierbare Knochenzemente.

Bone cements are used to treat compression fractures, fill bone defects and improve implant fixation in osteoporotic patients through reinforcement of weak bone. When the fracture repair is complete the bone cement ideally should degrade. In general, calcium-phosphate bone cements are biodegradable and can fulfill this temporary function. Several research groups have developed calcium-phosphate bone cements in the last years which have a chemical structure similar to that of the apatite of bone. However the conditions for processing the cement intraoperatively, as well as the mechanical properties and degradation characteristic of the various products show great variations. Clinical long-term studies have not yet been reported so far. Whether these new types of bone cements fulfill all the requirements for clinical application is still not certain and remains to be determined in future studies.

[Acetabular fractures in elderly persons. Primary endoprosthetic treatment]. / Acetabulumfraktur beim alten Menschen. Primäre endoprothetische Versorgung.

In the Department of Traumatology at the University of Ulm, 26 elderly patients with displaced acetabular fractures were treated with primary implantation of a hip joint endoprosthesis between 1986 and 1996. The principles of operative therapy are stabilization of the acetabular ring, grafting of acetabular defects with autogenous corticocancellous bone and cranial buttressing with a reinforcing ring. This concept permits immediate mobilization of elderly patients and full weight-bearing and thus results in favorable early postoperative results. Secondary complications typically caused by immobilization can therefore be avoided.

[Unilateral stepwise lengthening osteotomy of the femur]. / Die einzeitige treppenförmige Verlängerungsosteotomie des Femurs.

Intraindividual length differences up to 1.2 cm in femora, up to 1.0 cm in tibiae and up to 1.4 cm in whole leg length can be regarded as physiological. Length differences in childhood are frequently compensated for by functional adaptation in the chain of adjacent limbs. In adults, however, that adaptability is diminished and correction osteotomy after post-traumatic shortening may therefore be indicated more generously dependent on local and general criteria of operability. A conscientious analysis of bone geometry by clinical means, radiology and computed tomography is mandatory for the indication and planning of any correction osteotomy. Intraindividual leg length differences of more than 4 cm are preferentially treated by continuous callus distraction techniques. Shortening by less than 4 cm, however, is suitable for a one-stage stepwise prolongation osteotomy in the metaphysis of the femur, i.e. in the subtrochanteric or supracondylar region. These osteotomies are than stabilized by long condylar plates; the bony defects are filled up by auto- or allogenous corticospongeous bone. Simple modifications of the stepwise prolongation osteotomy permit additional corrections of torsional deviations up to 20 degrees or of axial deviations in the frontal or sagittal plane up to 5 degrees. The results of 24 one-stage stepwise prolongation osteotomies of the subtrochanteric and supracondylar femur after congenital or post-traumatic shortening are presented as well as the reason and respective therapies for three important complications.

[Prosthetic humeral head replacement in dislocated humerus multi-fragment fracture in the elderly--an alternative to minimal osteosynthesis?]. / Der prothetische Humeruskopfersatz bei der dislozierten Humerusmehrfragmentfraktur des alten Menschen--Eine Alternative zur Minimalosteosynthese?

In a prospective randomised study, comprising 30 aged patients with fractures of the proximal humerus (4-fragment fractures according to Neer) minimal osteosynthesis was compared to primary endoprosthetic replacement. The Constant score was used for evaluation during follow-up. After one year the results were similar in both groups. There were two complications necessitating revision surgery among the patients with minimal osteosynthesis and in four cases the implants had to be removed. In the group with primary endoprosthetic repair neither complications nor revision surgery occurred. Primary endoprosthetic replacement for the treatment of proximal humeral fractures appears as a therapeutic option with a low complication rate and a satisfying functional outcome. In older patients we need a safe mode of therapy permitting early mobilization and quick discharge from the hospital back to the patient's home. Endoprosthetic replacement fulfils these demands since it resembles a "one time surgery" without the risk of revision surgery for implant loosening, pseudarthrosis or ischemic necrosis of the humeral head.

[Correcting torsion after intramedullary nailing osteosynthesis of the lower extremity]. / Torsionskorrekturen nach Marknagelosteosynthesen der unteren Extremität.

Intraoperative control of torsion is delicate in intramedullary nailing of femur and tibia fractures. Post-traumatic torsional deformities cause clinical problems if the rotational 0-position, according to the neutral-0-method, cannot be attained or exceeded. The necessary precondition for every indication and planning of corrective osteotomies is conscientious analysis of the geometry of the lower extremities by clinical means, radiography and computed tomography. Operative procedures and techniques of corrective osteotomies in case of torsional deformities after intramedullary nailing are presented. Preoperatively, the intraindividual torsional differences in 15 patients with maltorsions of the femur were 33 degrees (-37/+50) and in 7 patients with maltorsions of the tibia 23 degrees (-21/+29). Positive signs indicate external and negative signs of internal maltorsions. Postoperatively, the intraindividual torsional differences were 6 degrees (-3/+14) in the femora and 7 degrees (+3/+12) in the tibiae. Therefore, the physiological torsional tolerance of 15 degrees was respected in all 22 patients. Additionally, limb lengthening was realized in 4 patients with shortening after intramedullary nailing of the femur. In 3 patients a one-step procedures with interposition of allogeneic cancellous bone in the osteotomy gap was performed and in one patient continuous callus distraction by external fixation.

[Occupational disease 2108. Degeneration pattern in magnetic resonance tomography of the lumbar spine in patient with differential weight-bearing activity]. / Berufserkrankung 2108. Kernspintomographische Degenerationsmuster der LWS von Patienten mit unterschiedlicher wirbelsäulenbelastender Tätigkeit.

The addition of vertebral disc degeneration to the job-related disease register raises the question of vertebral disc degeneration patterns according to loading strain. The readings of the lumbar vertebra of construction workers and nurses were compared with those of a group without workload. In the groups examined, aged 35 to 50, monosegmental damage was found in only 17% of the patients with high workload, as opposed to 29% of those with no workload, mostly with monosegmental damage at level L5/S1. Damage to the upper segments of the lumbar spine with intact discs in between was found exclusively in patients with high workload. Multiple segment damage in the age range examined was found in subjects with activities that add to the load of the spinal column. The value of MRI in assessing and evaluating illness originating from the vertebral discs is currently being discussed.

[Acetabular fractures in the elderly - primary endoprosthesis]. / Acetabulumfraktur beim alten Menschen : Primäre endoprothetische Versorgung.

In the Department of Traumatology at the University of Ulm, 26 elderly patients with displaced acetabular fractures were treated with primary implantation of a hip joint endoprosthesis between 1986 and 1996. The principles of operative therapy are stabilization of the acetabular ring, grafting of acetabular defects with autogenous corticocancellous bone and cranial buttressing with a reinforcing ring. This concept permits immediate mobilization of elderly patients and full weight-bearing and thus results in favorable early postoperative results. Secondary complications typically caused by immobilization can therefore be avoided.

Biodegradable bone cements.

Bone cements are used to treat compression fractures, fill bone defects and improve implant fixation in osteoporotic patients through reinforcement of weak bone. When the fracture repair is complete the bone cement ideally should degrade. In general, calcium-phosphate bone cements are biodegradable and can fulfill this temporary function. Several research groups have developed calcium-phosphate bone cements in the last years which have a chemical structure similar to that of the apatite of bone. However the conditions for processing the cement intraoperatively, as well as the mechanical properties and degradation characteristic of the various products show great variations. Clinical long-term studies have not yet been reported so far. Whether these new types of bone cements fulfill all the requirements for clinical application is still not certain and remains to be determined in future studies.

[Functional outcome of Eden-Hybinette-Lange operation in post-traumatic recurrent shoulder dislocation]. / Funktionelle Ergebnisse nach Eden-Hybinette-Lange-Operation bei posttraumatisch rezidivierender Schulterluxation.

OBJECTIVE: Post-traumatic recurrent dislocation is a major problem in the operative treatment of shoulder dysfunction in young athletes. This prospectively designed study evaluates the long-term results of a modified Eden-Hybinette procedure in young male athletes. The criteria were: capacity in sports, functional limit, and persistent pain. Genuine disorders of the glenoid or muscular imbalance of the shoulder joint were criteria for exclusion. PATIENTS AND METHODS: From 1982 to 1990, 143 patients underwent surgery. Seventy percent were reevaluated within a minimum period of 18 months after the operation. The functional results were calculated using the ROWE score as well as a visual analog scale (VAS). X-rays were done after the patient had given informed consent. RESULTS: VAS and ROWE score showed excellent/good results in 61%, fair results in 18%, and poor results in 21% of the documented cases. The rate of arthrosis was 25%. Redislocation occurred in 7%, mainly without any relevant trauma. The X-rays showed complete resorption of the bone graft in 30% of the cases. Best functional results and no redislocation were found in the patients who underwent surgery with fewer than 3 dislocations compared to those with more than 4 dislocation episodes. CONCLUSIONS: In cases of post-traumatic recurrent dislocation of the shoulder in young athletes, the modified Eden-Hybinette procedure is a good method of reestablishing sufficient stability of the shoulder. The operation should be performed prior to the 3rd dislocation episode. Four or more dislocation episodes show an increased tendency to redislocate and poor functional results.

[Arthroscopic capsule-labrum refixation in anterior shoulder dislocation. Primary or secondary management?]. / Arthroskopische Kapsel-Labrum-Refixation bei der vorderen Schulterluxation. Primär- oder Sekundärversorgung?

We examined 30 patients with an arthroscopic suture repair for anterior shoulder instability in a retrospective evaluation. The follow-up period ranged from 12 to 58 months with an average of 22 months. Arthroscopic suture repairs were done on 14 patients (acute group, average age 26.1 years) with acute detached glenoid labrum, confirmed on arthro-CT, within 10 days after the injury and on 16 patients (secondary group, average age 25 years) with chronic should dislocation. The evaluation according to the Rowe scale resulted in a mean score of 97.1 for the acute group compared with 92.7 for the secondary group. In each group we found one recurrent dislocation, which in the acute group was due to an adequate trauma. Two of the 14 acute group patients showed a reduction in external rotation of up to 20 degrees, compared with 6 patients in the secondary group. The external rotation of one patient in the secondary group was reduced to 40 degrees. The isokinetic muscle strength was decreased in both groups, both for 60 degrees/s and for 120 degrees/s, to 85% compared with the healthy side. The primary surgical therapy of young patients (below 25 years) with an acute shoulder dislocation and a detached glenoid labrum is recommended owing to the lower redislocation rate, an overall shortened course of treatment and a trend to better postsurgical range of motion.

Human osteoblasts from younger normal and osteoporotic donors show differences in proliferation and TGF beta-release in response to cyclic strain.

Mechanical stimulation of bone tissue by physical activity stimulates bone formation in normal bone and may attenuate bone loss of osteoporotic patients. However, altered responsiveness of osteoblasts in osteoporotic bone to mechanical stimuli may contribute to osteoporotic bone involution. The purpose of the present study was to investigate whether osteoblasts from osteoporotic patients and normal donors show differences in proliferation and TGF beta production in responses to cyclic strain. Human osteoblasts isolated from collagenase-treated bone explants of 10 osteoporotic patients (average age 70 +/- 6 yr) and 8 normal donors (average age 54 +/- 10 yr) were plated into elastic rectangular silicone dishes. Subconfluent cultures were stimulated by cyclic strain (1%, 1 Hz) in electromechanical cell stretching apparatus at three consecutive days for each 30 min. The cultures were assayed for proliferation, alkaline phosphatase activity and TGF beta release in each three parallel cultures. In all experiments, osteoblasts grown in the same elastic dishes but without mechanical stimulation served as controls. Significant differences between stimulated cultures and unstimulated controls were determined by a paired two-tailed Wilcoxon test. In comparison to the unstimulated controls, osteoblasts from normal donors significantly increased proliferation (p = 0.025) and TGF beta secretion (p = 0.009) into the conditioned culture medium. In contrast, osteoblasts from osteoporotic donors failed to increase both proliferation (p > 0.05) and TGF beta release (p > 0.05) in response to cyclic strain. Alkaline phosphatase activity was not significantly affected (p > 0.05) in normal as well as osteoporotic bone derived osteoblasts. These findings suggest a different responsiveness to 1% cyclic strain of osteoblasts isolated from normal and osteoporotic bone that could be influenced by both the disease of osteoporosis and the higher average age of the osteoporotic patient group. While osteoblasts from osteoporotic donors failed to increase proliferation and TGF beta release under the chosen mechanical strain regimen that stimulated both parameters in normal osteoblasts, it is possible that some other strain regimen would provide more effective stimulation of osteoporotic cells.

[Isokinetic muscle training with high motion speeds in the rehabilitation following surgical treatment of fresh anterior cruciate rupture]. / Isokinetisches Muskeltraining mit hohen Bewegungsgeschwindigkeiten in der Rehabilitation nach operativer Versorgung frischer vorderer Kreuzbandrupturen.

In the course of a prospective investigation 17 patients with operatively treated acute anterior cruciate ligament ruptures received an isokinetic muscle training with high motion velocities in addition to the common physiotherapy from the 7th to the 19th week after operation. The comparative group consisted of 17 patients with operatively treated acute anterior cruciate ligament ruptures who were receiving the common physiotherapy only. The aim of the study was to improve both the postoperative dysbalance between agonists and antagonists and the active muscular stabilisation of the knee. The isokinetic muscle training was done with 150 degrees/s and a motion limit for flexion/extension of 0-20-90 degrees. The postoperative muscular dysbalance was improved significantly in the isokinetic group after 6 weeks of training compared to the control group. The flexion/extension ratio of the operated leg at 60 degrees/s came to 100% in the training group compared to 135% in the control group. This difference was even more apparent at 180 degrees/s with 100% in the isokinetic group compared to 160% in the control group and at 240 degrees/s with 110% compared to 200% respectively. The average maximum torque was 10 to 15% better with the training group as with the control group though there was no training of maximum force done explicitly. There was no effect on the postoperative anterior stability of the knee.

[Improvement in the primary stability of the dynamic hip screw osteosynthesis in unstable, pertrochanteric femoral fractures of osteoporotic bones by a new glass ionomer cement]. / Die Verbesserung der Primärstabilität von DHS-Osteosynthesen bei instabilen, pertrochantären Femurfrakturen osteoporotischer Knochen durch einen neuen Glas-Ionomer-Zement.

Internal fixation of unstable intertrochanteric fractures of osteoporotic femurs often leads to complications, which are primarily caused by the mechanically weak bone. The aim of this study was to test whether a new glass-ionomeric cement could reinforce the weak trabecular bone of the femoral head and thus improve the preliminary stability of dynamic hip screws (DHS) used for internal fixation. As a standardized model, a intertrochanteric osteotomy was performed on eight pairs of human, female, cadaver femora; a bony defect was also created medially to diminish support of the femoral neck. To stabilize the osteotomy a 135 degrees DHS was inserted. In one femur of each pair the glass-ionomer cement was applied to see whether this would enhance stability. The elastic and irreversible deformation of the internal fixation was measured at the osteotomy level under a cyclic load of 1400 N applied to the femoral head. In both the cemented and the uncemented cases, the femoral head shifted irreversibly in the caudal direction and tilted into a varus position. Movements of the femoral head in other directions were mainly reversible and small. The irreversible movement of the femoral head was significantly larger, approximately twice as great, following uncemented DHS fixation than after cemented fixation. Most movement occurred during the first ten load cycles; higher load cycles did not increase the irreversible deformation in the cemented group, but in the uncemented group a further increase in deformation was detected. These results indicate that internal fixation of unstable intertrochanteric femoral fractures can be significantly improved by the use of cement.(ABSTRACT TRUNCATED AT 250 WORDS)