Aims

There is a lack of long-term data for minimally invasive acromioclavicular (AC) joint repair. Furthermore, it is not clear if good early clinical results can be maintained over time. The purpose of this study was to report long-term results of minimally invasive AC joint reconstruction (MINAR) and compare it to corresponding short-term data.

Aims

Extendible endoprostheses have been available for more than 30 years and have become more sophisticated with time. The latest generation is ‘non-invasive’ and can be lengthened with an external magnetic force. Early results have shown a worryingly high rate of complications such as infection. This study investigates the incidence of complications and the need for further surgery in a cohort of patients with a non-invasive growing endoprosthesis.

Introduction. Dislocation due to suboptimal cup positioning is a devastating complication in the early phase after total hip arthroplasty. Malpositioning can also result in other mechanical complications like subluxation, edge loading, increased debris, surface damage or squeaking in ceramic-on-ceramic hips. Preventing at least some of these complications in younger and more active patients is of paramount interest for the individual patient and for the society since optimized component orientation is an important determinant to reduce such risks and to further increase longevity of the implant. This study reports on two new surgical instruments that help the orthopedic surgeon to manually place both components within the optimized combined safe-zone (cSafe-Zone). Material and Methods. More than 900 minimal-invasive total hip arthroplasties (MIS-THA) have been performed between 2007 and 2015 in our institution using the minimal-invasive direct anterior approach (DAA) on an orthopedic table with foot holder. Cups were implanted applying the “stem-first” surgical technique i.e. the prosthetic stem dictates the orientation of the socket depending on the prosthesis design. A system-specific trial head which indicates the prosthesis-specific relative orientation of cup and stem and a modified cup impactor were used to finally seat the definitive acetabular socket manually during trial stem reduction while fully visually controlling the optimal orientation of the cup during impaction. This surgical technique drives both components into their optimal relative positions according to the combined version and the combined safe-zone concept in total hip arthroplasty. Results. Both new instruments, femoral trial head as well as the modified cup impactor, provide an easy way to manually control the optimal placement of the acetabular socket during impaction intraoperatively. The combined safe-zone is clearly indicated and the inverse interrelationship of stem and cup anteversion is ideally reflected by this simple mechanical system. In patients operated on with the “stem-first” technique the components were placed in the new cSafe-Zone in 94% of the cases and no squeaking or prosthetic impingement did occur in any of these patients. One early dislocation did occur and was treated by closed reduction. Conclusion. Stem-first technique using trial head-controlled impaction with a modified cup impactor is ideally suited for the minimal-invasive direct anterior approach in total hip arthroplasty to control the placement of both prosthetic components. It assists the surgeon in aligning the cup and the stem according to the cSafe-Zone in order to get the intended range of movement (iROM)

Total knee replacement is a standard procedure for the end-staged knee joints. The main concerns at the perioperative period are infection prophylaxis, pain control, and blood loss management. Several interventions are designed to decrease the blood loss during and after the operation of total knee arthroplasty. In the recent meta-analysis showed that early tourniquet release of the tourniquet for hemostasis increased the total measured blood loss with primary TKR about 228.7 ml. So, Intra-operative blood loss for hemostasis can be saved by not to release the tourniquet after implants fixation, irrigation, closure of the wound and the application of compression dressing. Our study showed that most of the post-operative blood loss was collected during the first few postoperative hours: 37% in the first 2 hours and 55% in the first 4 hours and 82.1% in the first 24 hours. So, clamping the drainage for the first 4 postoperative hours would reduce blood loss after TKA (518 v.s. 843 mL). The fall in hemoglobin and Hct are also of significant difference (1.64 vs. 2.09 for Hb; 5.18 vs.7.69 for Hct). Appropriate clamping for an optimal time may be the most economical and simple, and the benefits of clamping also appear to outweigh its potential risks. NO DRAIN at all is able to reduce the post-operative blood loss. Our study showed that the decrease of postoperative hemoglobin was significantly less than that in no-drain group (1.45±0.72 vs 1.8±0.91). Shorter hospital stay was achieved in the no-drain group (8.3 ± 2.6 vs 10.7±3.2 days). All patients achieved good range of motion (flexion: 0 to >90 degree)by the five days after operation and no prosthetic infection was noted during follow-up. Thus, the routine use of closed suction drains for elective minimal-invasive total knee arthroplasty is not recommended

Introduction:. Dislocation is still one of the major complications in total hip arthroplasty. Among other factors, it is important to maximize the intended range of movement (iROM) in order to reduce the risk for prosthetic impingement and to prevent edge loading in order to avoid surface damage and squeaking. Therefore, both components should be positioned in accordance to the new combined safe-zone for correct combined version and inclination aiming for an optimal relative orientation of both components. This study shows how this optimal combined orientation of both components can be determined for a specific total hip prosthetic system and how the result can be transferred to surgery and accomplished intraoperatively using minimal-invasive stem-first technique. Material and Methods:. 829 minimal-invasive total hip arthroplasties have been performed from 2007 to 2013 in our institution. In all of these surgeries a minimal-invasive direct anterior approach (DAA) was applied. All patients were positioned supine on a proprietary orthopedic table. In 168 cases a system-specific mechanical aiming device was used intraoperatively in order to control the combined version and inclination according to the specific safe-zone by orienting the prosthetic socket in relation to the prosthetic stem. This is called “stem-first technique” meaning that the prosthetic stem dictates the orientation of the socket. It does not mean the sequence of implantation. It's specific advantage is that the stem redirects the socket if it's position is modified. It equally applies to standard, anatomic (Fig. 1) or short stems (Fig. 2). The socket orientation is not primarily referred to bony landmarks of the pelvis but to the neck of the stem. Nevertheless the surgeon has to look for sufficient fixation of the socket within the acetabular bone. Leg length was measured in the surgical field additionally and prosthetic offset was adjusted according to the preoperative planning. All other patients were operated on in our standard minimal-invasive DAA-procedure. The majority of the patients suffered from osteoarthritis, their mean age was 68 years. Results:. Optimal component orientation for each prosthesis system was derived from its 3D-model by simulating hip joint motion in the physiologic range of motion. Optimal component orientation means maximizing the area of the combined safe-zone. In the stem-first group cup orientation was in the new combined safe-zone in 94% of the cases and no squeaking or prosthetic impingement did occur in any of these patients. Leg length did not differ more than +/− 5 mm. 83% of all patients receiveda ceramic-on-ceramic articulation, one early dislocation did occur and treated by closed reduction. Conclusion:. Stem-first technique is ideally suited for the minimal-invasive direct anterior approach in total hip arthroplasty to control the combined orientation of the prosthetic components and to achieve excellent clinical results. It assists the surgeon in aligning the cup and the stem according to their correct combined orientation in order to get an optimal range of movement especially in young patients

INTRODUCTION. Isolated injuries of the sacral bone are rare. The pathomechanism of these injuries are usually high velocity accidents or falls from large heights. The computer-assisted implantation of iliosacral screws (SI-screw) becomes more important in the treatment of dorsal pelvic ring fractures. The advantage of the minimal-invasive screw placement is the reduction of the non-union and deep wound infection rate. Another advantage of computer-navigated SI-screw placement is the reduction of intraoperative radiation for the patient and the surgical staff. The purpose of this study was to analyse the position of navigated iliosacral screws. METHODS. In the study group 74 screws (49 patients) were included and radiologically analysed. All screws were implanted using 3D-navigation (BrainLAB Vector Vision, Brainlab, Germany). Navigation was always executed with the same 3D c-arm (ARCADIS Orbic 3D, Siemens, Germany) and navigation system. We determined the grade of perforation and angular deviation in the postoperative CT-scans in all screws. The classification was performed according to Smith et al in 4 grades. Grade 0 implies no perforation and grade 1 a perforation less than 2 mm. Grade 2 correlates a perforation of 2–4 mm and grade 3 a perforation of more than 4 mm. Furthermore the intra- and postoperative complications as well as the body-mass-index, the co-morbidities and the duration of radiation were documented. The statistical analysis was executed using Microsoft Excel 2003. RESULTS. The mean age of the 49 patients was 42.2 years ± 18 (16–79 years). 28 male and 21 female patients were included. 25 patients received a single iliosacral screw in S1. In 19 cases a screw in S1 and S2 was placed on the same side. Four patients got bilateral SI-screws in S1 and another patient received bilateral screw placement in S1 as well as an additional screw in S2. The mean operation time was 100 min ±103 (20–540 min). The isolated time for SI-placement was 50 min ± 20 (20–93 min). The mean radiation time was 3 min ± 1.7 (0.9–7.4 min) (n = 28). Altogether 84% of the screws showed an intraosseous position (grade 0). In the axial plane 7 screws perforated ventrally, 5 screws penetrated the adjacent neural foramen. In the frontal plane the screws showed greater variations, 61% deviated less than 5° (grade 0). In the study group 5 screws needed surgical revision because of either malplacement or postoperative pain. There were no infections or neurological complications. There was no statistical correlation between screw perforation and the body-mass-index. CONCLUSION. The computer-assisted implantation of iliosacral screws is a safe method in relation to screw perforation. It shows a high security and accuracy concerning the ventral and dorsal cortical perforation. There is a frequent angular deviation in the frontal view without appearance of screw perforation or mechanic, neurologic and angiologic complications. The minimal-invasive procedure shows a low postoperative revision rate

Pertrochanteric femoral fractures are common and intramedullary nailing with a proximal femoral nail (PFNA®) is an accepted method for the surgical treatment. Accurate guide wire and subsequent hardware placement in the femoral neck is believed to be essential in order to avoid mechanical failure. Malpositioned implants may lead to rotational or angular malalignment or “cut out” in the femoral neck. Hip and knee arthritis might be a potential long-term consequence. The conventional technique might require multiple guidewire passes, and relies heavily on fluoroscopy. A computer-assisted surgical planning and navigation system based on 2D-fluoroscopy was developed in-house as an intraoperative guidance system for navigated guide wire placement in the femoral neck and head. To support the image acquisition process, the surgeon is supported by a so-called “zero-dose C-arm navigation” module. This tool enables a virtual radiation-free preview of the X-ray images of the femoral neck and head. The aim of this study was to compare PFNA® insertion using this system to conventional implantation technique. We hypothesised that guide wire and subsequent implant placement using our software decreases radiation exposure to the minimum of two images and reduces the number of drilling attempts. Furthermore, accuracy of implant placement in comparison to the conventional method might be improved and operation time shortened. We used 24 identical intact left femoral Sawbones® to simulate reduced pertrochanteric femoral fractures. First, we performed placement of the PFNA® into 12 Sawbones using the conventional fluoroscopic technique (group 1). Secondly, we performed placement of the PFNA® into 12 Sawbones guided by the computer-assisted surgical planning software (group 2). In each group, we first performed open and secondly minimal-invasive intramedullary nailing in six sawbones each. For minimal-invasive guide wire placement, a surgical drape imitated soft tissue coverage. Conventional and navigated technique used a C-arm fluoroscope (Siemens IsoC 3D®, Erlangen, Germany) in conventional 2D mode. Guidewire and subsequent blade placement in the femoral neck was evaluated. We documented: 1: the number of fluoroscopic images; 2: the total number of drilling attempts; 3: implant placement accuracy (3.1. Tip apex distance (TAD); 3.2. visible penetrations of the femoral neck and head; 3.3. blade-corticalis bone distance in the anteroposterior and lateral plane) and the 4: operation time. The number of fluoroscopic single shots taken to achieve an acceptable PFNA®-blade position was reduced significantly with computer-assistance by 71.5% (p<0.001) in the open and by 72,4% (p<0.001) in the minimally invasive technique. In each operation two X-rays for final documentation were taken. The average number of drilling attempts for the computer-guided system was significantly (p<0.05) less than that of the conventional technique in the minimally invasive procedure. The average number of drilling attempts showed no difference between the computer-assisted and conventional techniques in the open procedure. Accuracy of implant placement showed no difference between the computer-assisted and the conventional group. Computer assistance significantly increased the mean operation time for fixation of pertrochanteric femoral fractures with a PFNA® by 79.8% (p<0.001) in the open technique and by 54.4% (p<0.001) in the minimally invasive technique. Use of our computer-guided system for fixation of pertrochanteric femoral fractures by a PFNA® decreases the number of fluoroscopic single shots and of suboptimal guide wire passes while maintaining blade placement accuracy that is equivalent to the conventional technique. Computer-assisted surgery with our system increases the operation time and has just been tested in non-fractured sawbones. Although these results are promising, additional studies including fractured sawbones and cadaver models with extension of the navigation process to all steps of PFNA® introduction and with the goal of reducing the operation time are indispensable before integration of this navigation system into the clinical workflow

Introduction. Pedicle screw pullout or loosening is increased in the osteoporotic spine. Recent studies showed a significant increase of pullout forces especially for PMMA-augmentation. With application of conventional viscosity PMMA the risk of cement extravasation is associated. This risk can be reduced by using radiofrequency-responsive, ultrahigh viscosity bone cement. Method. 11 fresh-frozen lumbar vertebral bodies (VB) from 5 cadavers were collected and freed from soft-tissue and ligaments. By DEXA scan (Siemens QDR 2000) 8 VB were identified as severely osteoporotic (BMD 0.8 g/cm3), 3 VB were above this level. Two screws (6×45 mm, WSI-Expertise Inject, Peter Brehm, Weisendorf, Germany) were placed in the pedicles. Through the right screw 3ml of radiofrequency-responsive bone cement (StabiliT® ER2 Bone Cement, DFine, Germany) were injected via hydraulic cement delivery system (StabiliT® Vertebral Augmentation System, DFine, Germany). As control group, left pedicle screws remained uncemented. After potting the whole VB in technical PMMA (Technovit 4004, Heraeus Kulzer, Germany) axial pullout test was performed by a material testing device (Zwick-Roell, Zmart-Pro, Ulm, Germany). Results. The mean BMD of all specimen was 0.771 g/cm3 (min./max. 0.615/1.116, SD ± 0.170). Due to the definition of osteoporosis 8 specimens had a BMD lower than 0.8 g/cm3 (mean 0.677, min./max. 0.615/0,730, SD ±0.045). The non-osteoporotic group consisted of 3 specimens with a mean BMD of 1.020 g/cm3 (min/max 0.928/1.116, SD ±0.094). Overall we observed an increase in the mean axial pullout strength of 284% when using cement augmentated screws (non-cemented 385 N vs. cemented 1029 N, p 0,001). In the osteoporotic group the mean pullout force of the non-cemented screws was 407 N vs. 1022 N for the cemented screws (p 0.001). Similarly the pullout force rose in the non-osteoporotic group from 325 N for the non-cemented screws to 1048 N for the cemented screws p 0,001). All surgical procedures could be performed without technical problems. Conclusion. This cadaver study demonstrates the efficacy and effectiveness of pedicle-screw augmentation with ultra-high viscosity cement. Pullout forces are significantly increased, especially in osteoporotic bone. No complications like clogged in cannulated pedicle-screws or extravasation of bone cement were observed. In daily clinical routine radiation exposure to operator during cement delivery is reduced due to remote-controlled, automated delivery of radiofrequency-responsive bone cement. Furthermore availability of longer time to work with the cement (up to 30 min) is achieved; hectically injection or multiple-cement-mixing is not necessary anymore. The WSI-Expertise cannulated pedicle screws can be inserted and also augmented in a minimal-invasive technique. The PMMA then is injected through an extension adapter. PMMA augmentation of pedicle screws is already well established in spine surgery. With the combination of radiofrequency-responsive, ultra-high viscosity bone cement and cannulated pedicle screws this established procedure could become more controlled and safer for both patient and physician

Introduction

Isolated U-shaped sacral fractures are rare entities, mostly seen in polytraumatized patients, and hence, they are difficult to diagnose. While the pelvic ring remains intact across S2/S3, the U-shaped fracture around S1 leads to marked instability between the base of the spine and the pelvis. As severe neurological deficits can occur, timely treatment of these fractures is crucial. We present a novel technique of percutaneous reduction and trans-sacral screw fixation in U-shaped fractures.

Introduction: Osteochondral lesions of the talus (OCL III–IV°) need both extensive debridement for revitalisation and osteochondral reconstruction of the joint surface. This can be achieved by autologous cancellous bone-grafting and combination with a cell-free bioresorbable collagen-I/III scaffold. Our first results with this technique are presented. Methods: 25 patients (13 female, 12 male, mean age 30.9 years) with 26 osteochondral lesions of the talus (OCL III–IV°, 15 right, 11 left, 24 medial, 2 lateral, 1 bilateral case) were treated by minimal-invasive debridement, autologous cancellous bone-grafting and application of a porcine collagen-I/III scaffold (ChondroGide. ®. ) and evaluated prospectively by clinical scoring and MRI. The average follow-up was 23.2 (6–36) months. The mean defect size was 2.0 cm. 2. , the mean depth 0.7 cm. 14 defects have had at least one (1–3) operation on the defect before. By the use of a distractor a malleolar osteotomy could be avoided in all cases. Results: The AOFAS-score increased from 67.4 ± 12.2 to 89.5 ± 7.4 points (p< 0.01, t-test). On a visual 10-point scale pain decreased significantly from 6.2 to 1.7 while subjective ankle function improved from a mean of 4.4 ± 1.9 to 7.2 ±1.5. The results were rated excellent in 10/26 cases (38.4%), good in 14/26 (53.8) and fair in 2/26 (7.8%) cases. MRI follow-ups showed a complete or nearly complete defect filling. In two ankles a second-look arthroscopy unveiled the defects filled completely by a regenerative tissue with a smooth surface and good bonding. Full-core biopsies showed a mixed, mostly fibrocartilagenous tissue. Conclusion: By combination of cancellous bone-grafting with a cell-free collagen-I/III scaffold typical osteochondral lesions of the talus can be adressed effectively in a minimal-invasive one-step procedure. By utilizing mesenchymal stem cells (MSC) for an autogenous reparation process the use of expensive cultured chondrocytes is not necessary. The results concerning clinical functional improvement, pain reduction and patients’ satisfaction as well as defect filling in MRI are promising

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

Introduction: Posterior calcaneal exostosis treatment modalities showed many controversially opinions. After failure of the conservative treatment, surgical bursectomy and resection of the calcaneal exostosis are indicated by many authors. But clinical studies also show a high rate of unsatisfactory results with a relative high incidence of complications. The minimal surgical invasive technique by an endoscopic calcaneoplasty (ECP) could be an option to overcome some of these problems. Material and Methods: We operate on 121 patients with an age range between 17–58 years, 60 males and 61 females. The radiologic examination prior to surgery documented in all cases a posterior superior calcaneal exostosis that showed friction to the achilles tendon. All patients included in the study had no clinical varus of the hind foot, nor cavus deformities. 108 patients had undergone a trial of conservative treatment for at least 6 months and did not show a positive response. The average follow-up was 45.2 months (12–96). Results: According to the Ogilvie-Harris-Score 53 patients presented good and 55 patients excellent results, while 5 patients showed fair results, and 8 patients only poor results. All the post-operative radiographs showed sufficient resection of the calcaneal spur. Only minor postoperative complications were observed. Conclusion: ECP is an effective and of minimal-invasive procedure for the treatment of patients with calcaneal exostosis. After a short learning curve the endoscopic exposure is superior to the open technique has less morbidity, less operating time, and nearly no complications, moreover the pathology can better be differentiated

Introduction: The aim of this study was to evaluate the efficacy of the treatment of vertebral burst fractures with kyphoplasty. This minimal-invasive technique has been established for the treatment of osteoporotic compression fractures. The value for the treatment of burst fractures is still under research. Materials and Methods: Between 2003 and 2006, 31 patients presenting a traumatic vertebral burst fracture Magerl Type A3 of the thoraco-lumbar junction were treated with balloon kyphoplasty. All had a normal neurological examination. Assessment of the patients outcome included subjective evaluation of pain (VAS), evaluation of the clinical function (Oswestry-Score), SF-36 Medical Outcome Survey and radiologic evaluation. Results: The patients experienced an early pain relief and early mobilisation. Complications such as constriction of the spinal channel were not observed. The morphology of the vertebral body showed minor correction of the malposition. Conclusion: Kyphoplasty represents an efficient and minimal-invasive alternative for the treatment of burst fractures of the thoraco-lumbar junction. This technique allows an early return to daily activities with almost pain relief and with a low incidence of complications

Introduction: Revitalizing of the necrotic subchondral bone is the therapeutic paradigm in OCL/OD of the talus. Bone-marrow stimulation includes K-wire drilling or open debridement and cancellous bone grafting. Our results presented here are based on retrograde core-drilling and autologous cancellous bone-grafting of the talar dome guided by fluoroscopy and arthroscopy. Performed as a minimal-invasive technique, no additional harvesting site for bone-grafting is necessary. Methods: 38 patients (16 female, 25 male) with 41 symptomatic focal osteochondral lesions (ICRS I–III°) of the talus (3 bilateral) were treated by fluoroscopicguided retrograde coredrilling and autologous cancellous bone-grafting from the drilling cylinder. The results were evaluated retrospectively by use of the Ogilvie-Harris-Score (OHS), subjective clinical ratings on a visual analogue scale (VAS (0–10 max.)) and MRI. The patient’s mean age was 33.2 (±15.4) years. 27 patients (66%) reported a trauma history (sprain, compression). Most defects were located in the medial talus (36/41), 4 were lateral and 1 central. 34 cases were primary interventions. In 14 cases the growth plate of the distal tibial epiphysis was detectable. Results: The follow-up was 7–54 months with a mean of 29 (±13) months. The arthroscopic findings according to ICRS classified 12/41 as I°, 22/41 as II° and 7/41 as III° lesions. Preoperatively there were 11 poor, 25 fair, 4 good and 1 excellent ratings in the OHS-score turning into 1/9/13/18 postoperatively. There were 75.6% (31/41) overall good/excellent results. Good or excellent results were predominantly seen in grade I with 91.6% (11/12) and in grade II with 77.3% (17/22), whereas grade III showed success only in 42.8% (3/7). Open growth plates resulted good or excellent results in 85.7% (12/14 cases). First-line treatments showed a markedly better outcome of 82.3% (28/34) of good/ excellent results compared to 42.8% (3/7) of second-line treatments. Gender or trauma history did not influence the score results. Pain intensity on a VAS significantly reduced from 7.5 (±1.5) to 3.7 (±2.6). The subjective functional status on the VAS revealed a remarkable increase from 4.6 (±2.3) to 8.2 (±2.0), (p< 0.01). In MRI controls two patients showed a progression into demarcation (IV°) associated with a fair or poor score result. Conclusion: Our results indicate that fluoroscopic-guided retrograde core-drilling and autologous cancellous bone grafting is an appropriate operative option for talar OCL in minor grades I + II. Performed as a minimal-invasive technique, the subchondral necrosectomy and combined bone-grafting provide extended revitalization properties for OCL healing. Tending to success rates of only 42% in lesions III°, this technique can not generally be recommended here

Kyphoplasty is an efficient tool in the treatment of primary tumours (plasmocytoma) and osteolytic metastasis. Especially in plasmocytoma the current chemotherapy has increased life expectancy significantly. Therefore minimal-invasive stabilisation is not only a palliative treatment but really increases quality of life in those cases. Kyphoplasty offers several special tools and techniques to lower the leakage rate which is especially high with other cementoplasty techniques in the osteolytic spine. Materials and Methods: Prospective study of all vertebral tumours compared to osteoporotic fractures treated with kyphoplasty in 2004. 6 months follow up with VAS, SF36 and Oswestry score. Results: In 2004 we performed 67 Kyphoplasties. 12 kyphoplasties were performed in tumour cases (5 plasmocytoma and 7 metastasis). No complications occurred during surgery and during hospital stay. Follow-up included 11 tumours (1 death during F/U) and 46 osteoporotic fractures. 1 patient was treated with combined decompression/kyphoplasty. The pain level (VAS) was significantly reduced in all cases within 2 days (osteoporotic group 2,2 – tumour group 5,4) and reached nearly the same result after 6 weeks which persisted for 6 months (osteoporotic group 1,6, tumour group 2,1). The SF 36/Oswestry Score improved accordingly in both groups. At 6 weeks and 6 months F/U no statistical difference in the scores was seen. Conclusion: Kyphoplasty is a safe treatment method for osteolytic vertebral tumours with vertebral collapse. Clinically the results don’t differ from conventional cases. In cases with canal compromise, a combination with open techniques is possible. Special kyphoplasty techniques allow a reconstruction of the lytic wall and minimise leakage and cement dislocation. Significant improvement of life quality can be achieved offering the spine surgeon a valuable tool in the treatment of spinal metastasis

Increasing experiences in determining the indication for UKA and improvements in design and materials of the prosthesis led to better results. The AMC-Uniglide has an unconstrained mobile bearing with congruent area contact. This ensures complete freedom to rotate and slide upon one other with physiologic kinematic and low intrinsic stability. Minimal-invasive technique 30 patients with minimal-invasive AMC-Uniglide implantation technique were compared with 30 conventional implanted AMC’s and 30 total knee replacements in regard to rehabilitation and accuracy of implantation. 361 AMC-Uniglides 361 consecutive patients were investigated after AMC-Uniglide implantation. The mean duration of follow-up was 5.5 (2.3–12.5) years. Patients were reviewed using the American Knee Society Rating System. The roent-geno graphic analyses were performed with the American Knee Society Evaluation System. The clinical results of the investigated patients demonstrate that the AMC-Uniglide is a successful concept with a safe anchorage of the prosthesis and a good durability of the mobile bearings. An advantage of minimal invasive technique with regard to a reduced time of rehabilitation was found. The accuracy of implantation was comparable between the conventional and the minimal-invasive technique

Purpose: A complete collapse of osteoporotic vertebral fractures is difficult to treat. Restoration of vertebral height is very difficult, if ever possible. Kyphoplasty has been shown to restore vertebral compression fractures; however the best results are achieved in fractures without total collapse. Nevertheless some fractures develop osteonecrosis and pseudarthosis which can be easily seen on X-ray. For those cases we performed a retrospective study in order to evaluate the capacity of kyphoplasty in those difficult situations.

Methods: We analyzed the pre- and postoperative X-rays of vertebra plana treated between 2002 and 2005. Vertebral height (vh -anterior, middle and posterior) and kyphotic angle were measured with a digital imaging system. 2 independent examiners classified the preoperative X-rays into fractures with osteonecrosis/pseud-arthrosis (group 1) and without osteonecrosis (group 2). Statistical analysis with the non-parametric Mann-Whitney test was performed.

Results: Between 2002 and 2005 we performed 315 kyphoplasties. A total collapse of the vertebra (vertebra plana) was treated in 15 cases. Mean age 76 years, SD 5.2 years, average time of treatment after fracture 4 months. Osteonecrosis was persistent in 8 cases. The osteonecrosis group found a statistically significant higher degree of vertebral reconstruction (p < 0.013 - group 1: anterior vh 33%, middle vh 37,8%, posterior vh 19,1%; group 2: anterior vh 4,9%, middle vh 17,5%, posterior vh 1,8%). No significant difference was found in the analysis of the pre- and postop. kyphotic angle which could be due to the small sample size as the mean values are three-fold elevated in group 1 (p = 0.146, group 1: restoration mean 9,1° - maximum 18°; group 2: restoration mean 3,5° - maximum 13°).

Conclusions: Osteonecrosis is a positive predictive sign for the potential of vertebral reconstruction. Vertebral height can be significantly improved in those patients and the major changes of the kyphotic angle are possible. Even after 4 months, correction of the deformity is possible with kyphoplasty. However, without this sign, restoration of the vertebral height and correction of kyphosis is limited to rare cases.

Introduction: The accuracy of implantation is an accepted prognostic factor for the long term survival of a unicompartmental knee prosthesis (UKP). Minimal invasive technique is recommended for faster post-operative recovery. We developed an adaptation of a non image based system for either conventional or minimal invasive UKP implantation. We hypothesized that the used non image based navigation system will allow to place a UKP in the same position for both conventional and minimal-invasive approach. Methods: 20 patients were operated on with this experimental minimal invasive navigated technique (group A) and compared to a group of 20 cases operated with the conventional navigated technique (group B), matched to the study group according to age, gender andseverity of the coronal deformation. Coronal mechanical femorotibial angle and coronal and sagittal orientation of the components were measured on post-operative antero-posterior and lateral long leg X-rays. The rate of satisfactory implanted prostheses was compared in both groups with a Chi-square test with a 0.05 limit of significance. There was no significant difference in the pre-operative data between both groups. The post-operative coronal group A and 17 cases in group B. The prosthesis was optimally implanted in 17 cases in group A and 18 cases in group B. No difference was statistically significant. Discussion-Conclusion: The used navigation system allowed a very precise implantation of a UKP for both conventional and minimal invasive navigated technique

Introduction: Increasing experiences in determining the indication for UKA and improvements in design and materials of the prosthesis led to better results. The AMC-Uniglide has an unconstrained mobile bearing with congruent area contact. This ensures complete freedom to rotate and slide upon one other with physiologic kinematic and low intrinsic stability. Material and Methods:. Minimal-invasive technique 30 patients with minimal-invasive AMC-Uniglide implantation technique were compared with 30 conventional implanted AMC’s and 30 total knee replacements in regard to rehabilitation and accuracy of implantation. 361AMC-Uniglides 361 consecutive patients were investigated after AMC-Uniglide implantation. The mean duration of follow-up was 5.5 (2.3-12.5) years. Patients were reviewed using the American Knee Society Rating System. The roentgenographic analyses were performed with the American Knee Society Evaluation System. Results:. Minimal-invasive technique The comparison of 30 minimal-invasive UKA with 30 conventional UKA and 30 total knee replacements show an advantage of minimal invasive technique with regard to a reduced time of rehabilitation. The accuracy of implantation was comparable between the conventional and the minimal-invasive technique. 361 AMC-Uniglides Ninety-five percent of patients had no pain or slight pain at the latest follow-up, ninety-two percent had good or excellent clinical outcome. Three knees were revised for mobile bearing dislocation after medial UCA and three for lateral mobile bearing dislocation after lateral UCA. Five revisions because of component loosening were performed and there was one case of deep infection. Conclusion: The clinical results of the investigated patients demonstrate that the AMC-Uniglide is a successful concept with a safe anchorage of the prosthesis and a good durability of the mobile bearings. An advantage of minimal invasive technique with regard to a reduced time of rehabilitation was found. The accuracy of implantation was comparable between the conventional and the minimal-invasive technique

Introduction: Minimal-invasive techniques in total joint replacement are perceived to reduce soft tissue trauma. In TKR, reduced exposure during surgery bares the risk of component malpositioning. Therefore we have combined minimal invasive surgical techniques with non-CT based navigation in TKR. The purpose of this observational study is to describe first results of a controlled observational study comparing minimal invasive navigated total knee arthroplasty (MINI-NAV-TKR) to open navigated total knee arthroplasty (NAV-TKR) with respect to component positioning, surgery time and immediate postoperative complications. Materials and Methods: From June to September 2004, 26 MINI-NAV-TKR and 33 NAV-TKR have been performed by five surgeons in an unselected group of patients. In both groups, preoperative deformation of the mechanical leg axis was compared to postoperative mechanical leg axis using total one-leg standing radiographs. To control the safety and reproducibility of both procedures, time of surgery and postoperative complications were compared among both groups. Results: Given informed consent, 17 females and 9 males received 26 MINI-NAV-TKR, mean age was 71,06 years (ranging from 56,24 years to 84, 35 years), mean BMI was 28,8 kg/m2 and preoperative mechanical leg axis ranged from 18o varus to 16 o valgus. In NAV-TKR group, 12 males and 21 females at a mean age of 68,75 (range 51,97 to 86,73 years) received 33 TKR, mean BMI was 30,6 kg/m2 and preoperative mechanical axis ranged from 11 varus to 20 valgus. Postoperative radiographic leg alignment in the MINI-NAV-TKR group ranged from 1 degree valgus to 3 degree varus mechanical axis as compared to the NAV-TKR that ranged from 1 valgus to one outlayer of 4 degree varus. Time of surgery significantly differed among the groups (mean time Mini-NAV-TKR 115,23 min versus mean time NAV-TKR 98,15 minutes, p=0,002). In the MINI-NAV-TKR group 1 postoperative pin-infection and one conversion to an open procedure have been reported, in the NAV-TKR group 2 hematomas have been described. Conclusion: Despite increased mean time of surgery in the MINI-NAV-TKR group, component positioning and complications are comparable between both groups. These preliminary results indicate, that MINI-NAV-TKR combined with navigation is a safe and reproducible method