Introduction: Surgical treatment of most displaced proximal humerus fractures is challenging due to osteoporosis, which makes stable fixation difficult. Locking plates are intended to provide superior mechanical stability. The NCB^® -PH (Non-Contact-Bridging for the Proximal Humerus) plate is a locking plate of the latest generation that allows both open and minimally invasive (MI) application.

Methods: In a prospective multicenter study 131 patients were treated (n = 78 open, n = 53 MI). The open procedure was performed using a standard deltopectoral approach; the MI technique involved percutaneous reduction and an anterolateral deltoid split approach. Clinical and radiological follow-up was obtained 6 weeks, 3, 6 and 12 months after surgery. An iADL (instrumental activities of daily living) score was used for functional assessment, the subjective outcome was measured using VAS (Visual Analogue Scale) for pain and mobility.

Results: Improvement in function (ROM) was statistically significant in both groups (open and MI) postoperatively. Fracture type had the most significant impact on the complication rate. The most frequent complication was intraarticular screw perforation. The open treated group showed a higher complication rate. However, more C-type fractures (AO) were treated with this technique.

Conclusion: The NCB-PH is suitable as a routine method of treatment for proximal humerus fractures. Complication rate and functional outcome are comparable to the literature. The MI technique, which is limited by percutaneous fracture reduction, provides a less invasive option for patients requiring fast recovery. Complex fractures should preferably be treated with the open technique.

Objective: Modular tumour prostheses are often chosen for the reconstruction of osseous or joint defects following wide tumour resection in limb salvage procedures. In this retrospective trial we were looking for the clinical use in accordance to long-term-follow up especially on aseptic loosening of stem, wear of polyethylene, implant related complications and clinical and functional results.

Methods: From 1996 to 2008 we performed in our clinic in 69 cases a modular distal femur replacement (MUTARS) after wide bone or soft tissue tumour resection.

In our outpatient clinic we have assessed the clinical follow-up as clinical examination (Enneking-score) and standardized radiological follow-up for 5 years, then once per year. In the focus of interest were aseptic loosening of the stems, wear of polyethylene, and mechanical problems as implant failure

Results: In long-term-follow-up 6 polyethylene locks had to be changed into PEEK locks (8,6%9). PEEK-lock complications were not seen in this series. In 5 cases late infection of the prosthesis occured. In another 5 cases aseptic loosening of the prosthesis was diagnosed, fractures of the stems were not seen.

We conclude that in tumour patients with major osseous reconstruction after wide resection a certain loss ob function cannot be avoided, but the rate of complications in the long-term-follow-up after implantation of modular tumour prosthesis is acceptable.

Purpose: Early results of MI treatment of proximal humeral fractures in mainly osteoporotic bone stock using the NCB®-PH plate showed promising results reaching 62 points (86% of age related normal value) in Constant Score 6 months postoperatively (Roederer et al., submitted, 2006). The purpose of this study was to analyze the long-term results focusing on functional outcome and complications.

Methods: So far out of a total number of 90 cases we have gained the data of 35 patients (24 women, 11 men; age 68 in the mean) who sustained fractures of the proximal humerus treated MI with the NCB-PH® plate (Zimmer Company, Winterthur, Switzerland). In 16 cases (46%) osteoporosis has been diagnosed pre-operatively. Radiological follow-up in two planes and functional outcome is assessed clinically (ROM) and using visual analogue scale (VAS) for pain and function, Constant Score and a modified adl score (activities of daily living).

Results: Average ROM (in degree) for anteversion was 101, glenohumeral abduction 87, external rotation 31 and internal rotation 81. Average VAS for pain was 1, 9 points (10 = worst) and for function 6, 4 points (10 = best). Average Constant Score was 65 points, average adl score was 16 points (30 = best). Between 6 and 12 months postoperatively one case (2, 9%) of sintering of the humeral head and one case (2, 9%) of avascular necrosis was detected. In 3 cases (9%) of reversed impingement we performed total removal of hardware. Four younger patients (11%; age 60 in the average) underwent the same procedure demanding it though not suffering of limited ROM or pain.

Conclusion and Significance: In the early results NCB-PH® proved to be an effective MI method of treatment of fractures of the humeral head in the elderly patient with mainly osteoporotic bone stock. The 1 year follow up data show further functional improvement (approx. 5% of Constant Score). The complication rate remains low (5/35 = 14%).

Especially, no cases of lesions of the axillary nerve or frozen shoulder were seen. The latter we believe is due to the MI procedure and the early functional treatment due to high primary stability of the NCB-PH® plate. Despite good functional outcome, younger patients with higher levels of activity compared to the average patient sustaining proximal humeral fractures tend to feel subjective problems with the plate in situ demanding surgical removal of hardware. The long-term results also prove the NCB-PH® plate to be a safe and effective method of treatment reaching a functional outcome that enables the mostly old patients to regain an acceptable level of activity. Removal of hardware is easy to perform and offers especially in the younger patient a possibility to at least improve patients’ subjective outcome

Introduction: After whiplash injuries the majority of patients complain of pain, muscular dysfunctions and restricted movement of the cervical spine, however, the cause of these symptoms cannot be diagnosed.

Against this background, the hypothesis is formulated that functional disturbances in the form of pathological activities of the neck muscles occur as a result of a whiplash injury of the cervical spine. These pathological muscle activities can be demonstrated electromyographically and differ from the patterns of activity of healthy subjects.

Study Objective: Thus, the aim of this study was to establish an electromyographical method for the diagnosis of functional disturbances of the neck muscles after whiplash injuries of the cervical spine.

Material/Method: Primarily, an intramuscular recording of the electromyographical activity of the semispinalis capitis muscle was performed during flexion/extension and axial rotation in 46 patients with chronic symptoms after a whiplash injury of the cervical spine (QTF grade II) and 29 healthy subjects. The movement was controlled with techniques of virtual reality. The subject is immersed into a virtual outer space environment with a head-mounted display (HMD). In this virtual scene, the patient follows paths of motion of a signal (globe) with his/her gaze.

A subsequent study was conducted to validate the results that had been obtained. For this purpose, the electromyographical activity of the semispinalis capitis muscle was recorded in another subject group (n=20) and patients with acute symptoms as a result of a whiplash injury of the cervical spine (QTF grade II) (n=35).

Results: Compared to the physiological muscle activities that were established in the first subject group, changes could be observed in the chronic patient group.

Subjects in our study, for instance, show a decrease in electrical activity during flexion and the resulting stretching of the semispinalis capitis muscle, while the same movement causes an increase in activity in patients. On the basis of these differences, 93 % of subjects (specificity) and 83 % of patients (sensitivity) could be classified correctly with a discriminance analysis.

In the second study, the specificity was 88 % while a sensitivity of 86 % was determined in the acute patient population.

Conclusion: The results of these investigations enable a highly specific and sensitive diagnosis of muscular dysfunctions on the basis of the intramuscular recordings of the electromyographical patterns of activity of the semispinalis capitis muscle.

Background: In a car-to-car collision, an adequate force has to be exerted to produce an injury of the cervical spine. This force is often described with the parameter delta-V. Limits for delta-V were defined for rear-end, frontal and side collisions on the basis of dummy experiments and volunteer crash tests under laboratory conditions, and then transformed for the road accident situation. According to this definition, an injury in a rear-end or side collision is unlikely at delta-V< 10km/h and probable at delta-V> 15km/h. For frontal collisions, the values are 20 km/h and 30km/h. To this day, there is no data to confirm these limits in the actual road accident situation.

Objective: Our objective was to compare clinical data and data from accident analyses of individuals after actual car-to-car collisions in a prospective study. We intended to check the validity of the delta-V limits on the basis of this data.

Methods: 57 individuals (25 males/32 females) were included in the study. The delta-V was calculated by a technical expert on the basis of photographs of the two cars involved. The individuals who had been in an accident were evaluated with regard to their history. Those reporting symptoms underwent a radiological and clinical examination.

Results: Rear-end collisions (n=21): The median delta-V for rear-end collisions is 13 km/h (min=3 km/h; max=58 km/h). 7 individuals reported symptoms. Both patients had delta-V values< 9km/h. Delta–V 10km/h.

Frontal collisions (n=13): The median delta-V for frontal collisions is 24 km/h (min=8 km/h; max=50 km/h). 4 individuals reported symptoms. Under delta-V 20, one individual had a fractured cervical vertebra (QTF IV).

Conclusions: The existing limits for delta-V cannot be transferred without reservation from the laboratory test situation to the actual road accident situation. Injuries and even fractures of the cervical spine can occur at a delta-V < 10km/h, particularly with side collisions. At the same time, delta-V values > 15km/h do not necessarily result in an injury of the cervical spine.

Introduction: High tibial osteotomy is a recognised method of treatment for malalignment and osteoarthritis in young patients. Today computer aided surgery provides a chance to improve the existing techniques with a traceable planning and a higher degree of accuracy. Intraoperative use of fluoroscopy can be reduced and the results regarding leg axis can be improved.

Method: In our department since two years nearly all patients with malalignment of the lower legs had osteotomies guided with a navigation system. We used the Medivison-Praxim system in five, the Orthopilot prototype software in 12 and the Brain LAB System in 15 patients. The most common operation type was an open wedge osteotomy of the proximal tibia. A single cut osteotomy to correct the torsion and valgus deformity after a distal femur fracture is also possible with the Brain LAB system. Stabilisation was achieved using a plate with head locking screws (Tomofix, Synthes).

The degree of correction was controlled during the operation with the navigation system and compared with pre- and postoperative 2.5D ultrasound measurements to avoid projection errors of long standing x-rays.

Results: In all cases the intraoperative analysis was possible with the navigation systems. In one case, the computer crashed down due to interference of the fluoroscopy machine. No surgical problems were noted due to computer guidance noted. Fluoroscopy was used in all cases to verify the implant position as well as the resection plane after inserting the k-wires for saw blade guidance. The additional time for navigation was about 15 minutes.

The postoperative 2.5D ultrasound leg axis analysis showed a maximum of +/− 2° difference between the pre-, intra- and postoperative measurements.

Discussion: The chance to track the patient’s leg geometry through the complete procedure until bone fixation is the main benefit of computer assistance. The chance of failure during reduction and fixation can also be minimised and potential misalignment can be improved immediately. In addition, like in navigated joint replacement, the result of the surgical treatment can be simulated and judged before any action; values can be influenced showing the consequence right away. The final result regarding the leg axis is determined not only by the computer guidance, but by the primary stability of the implant as well. The chosen Tomofix plate is supposed to provide highest initial stability.

This first results show a promising increase of accuracy while radiation can be reduced. The actual values show that the main goal to increase the intraoperative accuracy in corrective osteotomies can be achieved with computer aided surgery.

In vitro experiments have shown, that stabilisation of the fibula in complete fractures of the lower leg give more stability compared to a single stabilisation of the tibia. However it is not known how this biomechanical conditions influence the bone healing process. To investigate the effect of fibula stability in tibia fracture healing tibial osteotomies in rats with and without fibula fractures were compared.

Male wistar rats (n=18) were operated by a transverse osteotomy of the proximal tibia of the left leg. Fracture was stabilised by intramedullary nailing. In 8 cases an additional closed fibula fracture was performed. The healing period was 21 days.

Each whole leg was examined by x-ray. After explantation of the tibia and removing of the nail and the fibula, the tibia was examined by CT-Scan, three-point-bending and histological evaluation.

Animals, who had a fibula fracture along with the tibia fracture presented with delayed healing. Density in CT-scan was 30% lower (p=0,0002) in animals with a fibula fracture (405mg/ccm, SD:64) compared to those without a fibula fracture (mean=577mg/ccm, SD:17). In three point bending the bending stiffness was 79% lower (p=0,0006) in animals with a fibula fracture (mean=252Nmm/mm, SD:118) compared to animals without a fibula fracture (mean=1219Nmm/mm, SD:478). The breaking force was 59% lower (p=0,0004) in animals with a fibula fracture (mean=17,5N, SD:6) compared to animals without a fibula fracture (mean=42,4N, SD:14).

Complete fractures of the lower leg healed considerably worse than solitary fractures of the tibia. We conclude that the missing of rotational stability of our k-wire fixation of the tibia with a unfixed fibula fracture is one of the reasons for the delay in fracture repair. The results support the in vitro findings of the biomechanical importance of the fibula for the stability of tibia fractures.

Non-steroidal anti-rheumatics (NSAR) are often used in patients with fractured bones for analgetic reasons. This animal experiment was performed to determine the influence of NSAR on the process of fracture healing. As an alternative central acting analgetic without peripheral effect Tramadol was included in this experiment.

Wistar rats were operated by a transverse osteotomy of the proximal tibia of the left leg, fracture was stabilized by intramedullary nailing (healing period 21 days). All therapeutics were applied orally, twice a day. The animals were divided in 4 groups, 10 rats each: Group 1 was treated with placebo, group2 with tramadol (20mg/kg bodyweight/day), group3 with Diclofenac-Colestyramin (5mg/kg/bw./day) over 7 days followed by 14 days placebo, group4 with Diclofenac-Colestyramin (5mg/kg/bw./day) over 21 days. On day 21 the rats were sacrificed and each leg was examined by x-ray, than the tibia was examined by CT-Scan, three-point-bending and histological evaluation.

There were no significant differences between group1 and 2 and between group3 and 4, respectively. Therefore the data of group1 and 2 as well as group3 and 4 are put together.

The results of CT and 3-point-bending showed, that rats treated by Diclofenac presented with delayed fracture healing compared to those treated by placebo or Tramadol. Bone density was 30% lower (p = 0,0001) in animals treated with Diclofenac (mean = 577mg/ccm, SD:53,1 in group1 and 2 vs. mean = 404,3mg/ccm, SD:27,3 in group3 and 4).

The breaking force was 45% (p = 0,0009) lower (mean = 42,4N, SD:14,2 vs. mean = 23,3N, SD:8,2) and the bending stiffness 56% (p = 0,0039) lower (mean = 1218,9Nmm/mm, SD:477,9 vs. mean = 532,6Nmm/mm, SD:389,9) in animals, treated with diclofenac. Diclofenacserumlevels on day 21 in rats with longtime diclofenac application (mean = 242ng/ml, SD:47,7) were comparable to those in humans.

Oral application of Diclofenac significantly delayed fracture healing in rats. This effect might be comparable to other NSAR and fracture healing in humans.

We studied the effect of full and partial weight-bearing on venous peak velocity in the legs of 73 subjects. We used colourflow Duplex ultrasound to determine the minimal amount of weight-bearing required to produce the same venous peak velocity as full weight-bearing.

We found that the venous peak velocity remains the same in the femoral vein during partial weight-bearing (196 N and above). This is important for postoperative physiotherapy and thrombo-prophylaxis. The median peak velocity was 30 cm/s. This corresponds to an amplification factor of four in relation to the individual resting level (peak velocity).

In addition, we found that partial weight-bearing at 196 N can reliably be reproduced. The median value of partial weight-bearing after a three-day training programme was 206 N.

The treatment of large bony defects by callus distraction is well accepted, but the duration of treatment is long and the rate of complications increases accordingly. We have examined the effect of the stiffness of the axial fixator on reducing the time for maturation of callus.

We created a mid-diaphyseal defect of 15 mm in the metatarsal bone in sheep and stabilised it with a ring fixator. After four days a bony segment was transported for 16 days at 1 mm per day. After 64 days the animals were divided into four groups, three with axial interfragmentary movement (IFM) of 0.5, 1.2 and 3.0 mm, respectively, and a control group.

The 3.0 mm IFM group had the smallest bone density (p = 0.001) and area of callus and the largest IFM after 12 weeks; it also had typical clinical signs of hypertrophic nonunion. The most rapid stiffening of the callus was in the 0.5 mm group which had the smallest IFM (p = 0.04) after 12 weeks and radiological signs of bridging of the defect. These results indicate that suitable dynamic axial stimulation can enhance maturation of distraction callus when the initial amplitude is small, but that a large IFM can lead to delayed union.

Corrective osteotomies are often planned and performed on the basis of normal anatomical proportions. We have evaluated the length and torsion of the segments of the lower limb in normal individuals, to analyse the differences between left and right sides, and to provide tolerance figures for both length and torsion.

We used CT on 355 adult patients and measured length and torsion by the Ulm method. We excluded all patients with evidence of trauma, infection, tumour or any congenital disorder.

The mean length of 511 femora was 46.3 ± 6.4 cm (±2sd) and of 513 tibiae 36.9 ± 5.6 cm; the mean total length of 378 lower limbs was 83.2 ± 11.4 cm with a tibiofemoral ratio of 1 to 1.26 ± 0.1. The 99th percentile level for length difference in 178 paired femora was 1.2 cm, in 171 paired tibiae 1.0 cm and in 60 paired lower limbs 1.4 cm.

In 505 femora the mean internal torsion was 24.1 ± 17.4°, and in 504 tibiae the mean external torsion was 34.9 ± 15.9°. For 352 lower limbs the mean external torsion was 9.8 ± 11.4°. The mean torsion angle of right and left femora in individuals did not differ significantly, but mean tibial torsion showed a significant difference between right (36.46° of external torsion) and left sides (33.07° of external torsion). For the whole legs torsion on the left was 7.5 ± 18.2° and 11.8 ± 18.8°, respectively (p < 0.001). There was a trend to greater internal torsion in femora in association with an increased external torsion in tibiae, but we found no correlation. The 99th percentile value for the difference in 172 paired femora was 13°; in 176 pairs of tibiae it was 14.3° and for 60 paired lower limbs 15.6°.

These results will help to plan corrective osteotomies in the lower limbs, and we have re-evaluated the mathematical limits of differences in length and torsion.