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L Perlick

Publications and source records attributed to L Perlick.

At least 37 records · Page 2Linked to original sources
PubMed2004

Radiological results of image-based and non-image-based computer-assisted total knee arthroplasty.

Restoration of the mechanical limb axis and accurate component orientation are two major factors affecting the long-term results after total knee replacement (TKR). Different navigation systems are available to improve the outcome. Image-based systems require pre-operative CT scans, while non-image-based systems gain all necessary information intra-operatively during a registration process. We studied 130 patients who received a TKR either using the CT-based (Knee 1.1) or the CT-free module (CT-free Knee 1.0) of the BrainLAB Vector-Vision Navigation System. Post-operative leg alignment and component orientation was determined on long-leg coronal and lateral X-rays. Sixty of 65 patients in the CT-based group and 63/65 patients in the CT-free group had a post-operative leg axis between 3 degrees varus/valgus. No significant differences were found for varus/valgus orientation of the femoral and tibial components.

Aged↗
PubMed2004

[Navigated implantation of total knee endoprostheses in secondary knee osteoarthritis of rheumatoid arthritis patients as compared to conventional technique].

INTRODUCTION: The operative treatment of a secondary gonarthrosis due to RA claims high quality in soft tissue balancing and accurate alignment in total knee arthroplasty (TKA) which are essential for good long-term results. The efficiency of an imageless computer-assisted implantation in TKA was evaluated and compared with conventional technique. METHOD: The authors implanted each 40 TKA either using the imageless computer-assisted or classical surgeon-controlled technique. The quality of implantation was studied on postoperative long leg coronal and lateral x-rays. RESULTS: A postoperative leg axis between 3 degrees varus and 3 degrees valgus was obtained in 37 patients (92.5%) in the study group and 30 patients (75%) in the control group. Complications influencing the clinical outcome did not occur. CONCLUSION: The use of the imageless Vector-Vision navigation system provides the patient a good chance for longterm survival. Especially the ligament balancing tool appears to be useful. Cutting errors can be detected and intraoperatively corrected.

Arthritis, Rheumatoid↗
PubMed2004

[Reconstruction of insufficient anterior cruciate ligament].

AIM: Reconstruction of insufficient anterior cruciate ligament (ACL) has become a standard operative procedure. Still, graft choice and fixation technique are discussed controversially. The objective of this study was to ascertain the current treatment of ACL reconstruction in german orthopedic surgery and trauma centers. METHODS: A total of 250 trauma and 220 orthopedic surgery centers were asked for their treatment strategy and postoperative procedure of ACL reconstruction in an anonymous German-wide survey. RESULTS: 230 questionnaires (48.9 %) were returned for evaluation. 90.4 % of the surgeons reconstruct the anterior cruciate ligament. Patellar tendon is used by 73 % of orthopedists and 80.7 % of trauma surgeons. Reconstruction with semitendinosus tendon transplant is performed by 71.6 % of the orthopedists and 41.6 % of trauma surgeons. For tibial fixation the interference screw is as well of the semitendinosus tendon as of the patellar tendon the most common technique. In about 30 % each the femoral fixation results from interference screw and endo-button. CONCLUSION: There is still no generally accepted intra- and postoperative strategy for reconstruction of ACL. Reconstruction with semitendinosus tendon becomes more common.

Analgesics↗
PubMed2004

[Influence of sequence type on the extent of the susceptibility artifact in MRI--a shoulder specimen study after suture anchor repair].

PURPOSE: To compare the extent of susceptibility artifacts after metallic suture anchor implantation by analyzing 14 different MRI sequences. MATERIALS AND METHODS: A metallic suture anchor was implanted in the central area of three glenoid porcine specimens. The specimens were imaged with a 1.5 T scanner using a protocol of 14 standard sequences including gradient echo, spin echo and turbo spin echo sequences with and without fat-saturation. Artifact size was measured for each specimen and sequence. The resulting mean artifact areas were determined for each type of sequence and the mean values of the three specimens compared. RESULTS: Gradient echo-sequences produced significantly larger artifact areas than the spin echo and turbo spin echo sequences, whereby the artifacts of the 3D-gradient echo sequences were smaller than the artifacts of the 2D-gradient echo sequences. A turbo spin echo sequence with a high readout band width and a short effective echo time showed the best results. For the conventional spin echo sequence, a reduction in the echo time did not significantly decrease the artifact size. Spectral fat-saturation did not affect the area of the susceptibility artifact compared to the non-saturated sequence. CONCLUSION: Gradient echo sequences should not be used after metallic suture anchor repair. Turbo spin echo sequences showed a decrease in the artifact size compared to conventional spin echo sequences and should be performed with a short effective echo time and a high band width. Spectral fat- saturation did not increase the artifact size significantly.

Animals↗
PubMed2004

Alignment in total knee arthroplasty. A comparison of computer-assisted surgery with the conventional technique.

Restoration of neutral alignment of the leg is an important factor affecting the long-term results of total knee arthroplasty (TKA). Recent developments in computer-assisted surgery have focused on systems for improving TKA. In a prospective study two groups of 80 patients undergoing TKA had operations using either a computer-assisted navigation system or a conventional technique. Alignment of the leg and the orientation of components were determined on post-operative long-leg coronal and lateral films. The mechanical axis of the leg was significantly better in the computer-assisted group (96%, within +/- 3 degrees varus/valgus) compared with the conventional group (78%, within +/- 3 degrees varus/valgus). The coronal alignment of the femoral component was also more accurate in the computer-assisted group. Computer-assisted TKA gives a better correction of alignment of the leg and orientation of the components compared with the conventional technique. Potential benefits in the long-term outcome and functional improvement require further investigation.

Adult↗
PubMed2004

[Accuracy of an image-free cup navigation system--an anatomical study].

The position of the acetabular cup is of decisive importance for the function of a total hip replacement (THR). Using the conventional surgical technique, correct placement of the cup often fails due to a lack of information about pelvic tilt. With CT-based and fluoroscopically-assisted navigation procedures the accuracy of implantation has been significantly improved. However, additional radiation exposure, high cost and the increased time requirement have hampered the acceptance of these techniques. The present anatomical study evaluates the accuracy of an alternative procedure--image-free navigation. This method requires little extra effort, does not substantially delay surgery, and needs no additional imaging. Press-fit cups were implanted in 10 human cadaveric hips with the help of the image-free navigation system, and the position of the cups was checked intraoperatively with a CT-based navigation system and postoperatively by computed tomography. All cups were implanted within the targeted safe zone with an average inclination of 44 degrees (range 40 degrees-48 degrees, SABW 2.7 degrees) and an average anteversion of 18 degrees (range 12-24 degrees, SABW 4.1 degrees). Analysis of accuracy of the image-free navigation software revealed only a small, clinically tolerable deviation in cup anteversion and cup inclination in comparison with the CT-based navigation system and the post operative CT scans. The evaluated image-free navigation system appears to be a practicable and reliable alternative to the computer-assisted implantation of acetabular cups in total hip arthroplasty.

Acetabulum↗
PubMed2003

[CT-based and CT-free navigation in knee prosthesis implantation. Results of a prospective study].

INTRODUCTION: Accurate leg alignment is one important factor for long-term survival in total knee arthroplasty (TKA). The classical surgeon-controlled technique is associated with a deviation of the leg axis of more than 3 degrees in up to 30% of cases, regardless of the surgeon's experience. The aim of this study was to test the efficiency of a CT-based and CT-free navigation system in restoration of the leg axis. METHOD: 100 TKA (PFC-Sigma, DePuy) were implanted either using the CT-based or CT-free module of the Vector-Vision navigation System (BrainLAB). There were no significant differences between the groups in preoperative leg deformity. Accuracy of implantation was determined on postoperative long-leg coronal and lateral X-rays. RESULTS: A postoperative leg axis between 3 degrees varus and 3 degrees valgus was obtained in 46 patients (92%) in the CT-based group (A) and in 48 patients (96%) in the CT-free group (B). No significant differences were found for varus / valgus orientation (+/-3 degrees ) of the femoral (A=96%; B=94%) and tibial (A and B each 98%) components. CONCLUSION: The use of the CT-based and CT-free Vector-Vision system allows a significant improvement in the accuracy of implantation in TKA. The CT-based module has the advantage of precise preoperative planning. On the other hand there are additional costs and time-consuming logistics. The advantages of the CT-free module are the intraoperative visualisation of the leg axis, the ligament balancing and joint kinematics. Cutting errors can be detected and corrected with both modules.

Adult↗
PubMed2003

[Unrecognized and untreated rupture of the Achilles tendon-operative treatment in cases of unstable scar tissue].

Although the clinical picture of an acute rupture of the Achilles tendon is clear, it remains unrecognized or falsely evaluated in up to 10% of all cases. Wrong management without surgical intervention or adequate immobilization frequently leads to unstable scar tissue, requiring completely different therapy and rehabilitation than in the case of an acute injury. Between 6/2000 and 3/2002 11 patients (average age 53 years, M:F=9:2) with a neglected rupture of the Achilles tendon undergoing reconstruction of unstable scar tissue were evaluated in a prospective study. The preoperative cardinal symptoms were loss of strength and stress pain. The length of the unstable scar tissue measured 3.5 cm on average (2.0-6.0 cm). After resection of the scar lesion, a broad central gastrocnemius aponeurotic flap was performed in nine cases,whereas two cases underwent a central tendon shift. As a result of the surgical tendon reconstruction,we noted a 40% mean increase of strength in the final examination. This improvement was associated with less pain and a comparable range of motion. Protracted wound secretion and superficial wound necrosis were recorded on one and two occasions, respectively. Ultrasound and X-ray as preoperative imaging diagnostic tools in addition to the clinical picture appear to be sufficient for proper indication and planning of surgical intervention. The broad central aponeurotic flap has proven to be the most successful method in our patients. In cases of a short distal end, the "grip-box plasty" with a central tendon shift is indicated. Even lesions up to 6 cm can thus be repaired with autologous tissue.

Achilles Tendon↗
PubMed2003

[Innovations in total knee arthroplasty].

The development of total knee arthroplasty started in the fifth decade last century. Modern total knee joint systems represent a high grade of modularity for a usage within the whole range of joint destruction situations, such as for rheumatoid arthritis. Innovations for improved long term survival can be seen in methods reducing aseptic loosening, such as new implant materials or mobile platforms. Moreover improved surgical techniques for precise component orientation and reconstruction of a neutral leg axis have been introduced using computer assisted surgery. So far the results using this technique are very promising. Long term results are not yet available.

Arthroplasty, Replacement, Knee↗
PubMed2003

[Tissue toxicity of local anesthetics. An in vivo trial].

AIM: Local anesthetics are often administered intra-articularly after knee surgery. The aim of this study was to determine differences in irritancy of local anesthetics in an in vivo test performed on the chorioallantoic membrane of hen's eggs (HET-CAM test) to evaluate the specific irritation score. METHOD: After incubation for 9 days, the chorioallantoic membrane was prepared and then exposed to different local anesthetics (Naropin, Scandicain,Carbostesin,Xyloneural). RESULTS: We found no irritating values for the tested substances. No vascular injuries of the chorioallantoic membrane could be detected. Therefore, the irritation score was measured according to the standard protocol with an irritation score=0. CONCLUSION: Our results show that local anesthetics often used in clinics do not provoke severe vascular injuries as a sign of tissue toxicity. Therefore, the customary concentrations can be recommended for clinical use.

Allantois↗
PubMed2003

[Useability of an image based nagivation system in reconstruction of leg alignment in total knee arthroplasty - results of a propsective study].

Accurate leg alignment is one important factor for long term survival in total knee arthroplasty (TKA). The aim of this study was to determine the accuracy of a CT-based navigation system in restoration of the leg axis. 80 TKA (P.F.C.-Sigma--DePuy) were implanted either using a CT-based navigation-system or the conventional technique. There were no significant differences between the groups according to the preoperative leg deformity. Accuracy of implantation was determined on postoperative long-leg coronal and lateral x-rays. A postoperative leg axis between 3 degrees varus and 3 degrees valgus was obtained in 35/40 patients (88%) in the computer assisted and 28/40 patients (70%) in the conventional operated group. A higher precision in the sagittal plane was seen for the tibial (computer assisted: 3.9 +/- 2.2 vs. conventional TKA 1.3 +/- 5.8) and the femoral component (computer assisted: 3.5 +/- 2.3 vs. conventional TKA 6.9 +/- 3.6). The use of the CT-based VectorVision-System allows a significant improvement in the accuracy of implantation in TKA. The CT-based module has the advantage of a precise preoperative planning and a useful documentation and control tool for each important step. On the other hand there are additional costs and time consuming logistics.

Adult↗
PubMed2001

Impact of a nickel-reduced stainless steel implant on striated muscle microcirculation: a comparative in vivo study.

The impairment of skeletal muscle microcirculation by a biomaterial may have profound consequences. With moderately good physical and corrosion characteristics, implant-quality stainless steel is particularly popular in orthopedic surgery. However, due to the presence of a considerable amount of nickel in the alloy, concern has been voiced in respect to local tissue responses. More recently a stainless steel alloy with a significant reduction of nickel has become commercially available. We, therefore, studied in vivo nutritive perfusion and leukocytic response of striated muscle to this nickel-reduced alloy, and compared these results with those of the materials conventional stainless steel and titanium. Using the hamster dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate that reduction of the nickel quantity in a stainless steel implant has a positive effect on local microvascular parameters. Although the implantation of a conventional stainless steel sample led to a distinct and persistent activation of leukocytes combined with disruption of the microvascular endothelial integrity, marked leukocyte extravasation, and considerable venular dilation, animals with a nickel-reduced stainless steel implant showed only a moderate increase of these parameters, with a clear tendency of recuperation. Titanium implants merely caused a transient increase of leukocyte-endothelial cell interaction within the first 120 min, and no significant change in macromolecular leakage, leukocyte extravasation, or venular diameter. Pending biomechanical and corrosion testing, nickel-reduced stainless steel may be a viable alternative to conventional implant-quality stainless steel for biomedical applications. Concerning tolerance by the local vascular system, titanium currently remains unsurpassed.

Animals↗
PubMed2001

Radiographic spinal profile changes induced by cage design after posterior lumbar interbody fusion preliminary report of a study with wedged implants.

STUDY DESIGN: A prospective comparative radiographic study between two geometrically varying implants utilized in single-level posterior lumbar interbody fusion (PLIF) was performed. OBJECTIVE: The aim of this study was to determine the influence of 4 degrees wedged cages on postoperative lateral lumbar spinal profile. SUMMARY OF BACKGROUND DATA: The biomechanical and clinical importance of realigning the sagittal lumbar profile in surgical management of spinal instabilities is known. Wedged cages are therefore increasingly attaining popularity in PLIF. As yet the significance of wedged implants on postoperative sagittal spinal profile has not been assessed. METHODS: Forty patients were randomly assigned to two equal-sized groups. In one group rectangular cages and in the second group cages with a wedged design and an inclination of 4 degrees were implanted. Quantitative assessment of the lumbar spinal profile on standing neutral lateral radiographs was performed before surgery as well as 6 weeks and 12 months after surgery. Results were statistically compared. RESULTS: A significant improvement of lumbar sagittal profile after use of 4 degrees wedged compared with nonwedged cages was not found. The greatest effect on lumbar profile and segmental lordosis was observed in fusion of segment L4-L5 with 4 degrees wedged cages. CONCLUSIONS: These results show that normal sagittal alignment after single-level lumbar fusion can be achieved with rectangular and 4 degrees wedged cages. Although results after utilization of 4 degrees wedged cages do not significantly differ, these implants offer the surgeon one more sizing variation with which physiologic lumbar lordosis may be attained. The biomechanical implications of wedged implants on the rigidity of a fused segment remain to be analyzed.

Female↗
PubMed2001

Treatment of enterogenic endotoxinemia with lactoferrin in rats.

Enterogenic endotoxinemia was induced in 28 Wistar rats by means of intraperitoneal injection of 80 mg/kg carrageenan and intraduodenal administration of 5 x 10(10)/kg Escherichia coli bacteria and 10 mg/kg nebacetin. The control group A received 600 mg/kg albumin in addition via the duodenal probe, and the groups B, C and D received 20, 40 and 80 mg/kg lactoferrin, respectively. The therapeutic effect was investigated by determining the endotoxin activity in the plasma every hour. In addition, the bacterial contamination of peritoneal lavages and mesenteric lymph nodes was checked by incubation for 48 h at 37 degrees C. The period of observation was 5 h. There was a dose-dependent improvement of the endotoxin activity in plasma and the bacterial contamination of the peritoneum cavity and mesenteric lymph nodes after lactoferrin administration. The maximum plasma endotoxin activity could be reduced by 89% with 80 mg/kg lactoferrin.

Albumins↗
PubMed2001

[The posterior lumbar interbody fusion with cages (PLIF) and transpedicular stabilization].

The development of intervertebral cages has significantly innovated the original technique of posterior lumbar interbody fusion (PLIF). In this study we present the results of patients treated for degenerative or postoperative segmental spinal instabilities by PLIF with cages and pedicular stabilisation (360 degrees-instrumentation). Between 1992 and 1999 we implanted either CFRP-, PEEK- or Titanium-cages in 86 patients. 78 patients were adequately followed up over a period of at least 12 months (average 2,6 years). 5 patients were stabilised over 2 segments, so that ultimately 83 fused segments were evaluated.15% of all patients had an excellent, 51% a good, 28% a moderate and 5% an insufficient clinical result. Degenerative instabilities had a better outcome with 73% good or excellent clinical results, compared to postoperative instabilities (56%). Based on stringent radiographic fusion criteria we found true bony fusion in 52% of all segments after 12 months, 63% after 24 months, 72% after 36 months, and 78% after 48 months. In 21 segments cage packing was performed with autologous spongiosa, while in 62 segments a combination of cortical bone and spongiosa obtained from osseous structures at the operation-site were used as packing material. At the 24 month radiographic control we found a slightly higher fusion rate for those segments treated with autologous spongiosa obtained from the iliac crest. Neither for cages nor for pedicular screws was implant failure or material fatigue found. Serious entero-, pulmo-, cardio- or urological complications were not observed. Nonetheless the necessity for operative revision was 9%. A postoperative semiquantitative evaluation of segments neighbouring the fused vertebra revealed in 28% an increase in degenerative changes. Particularly after 360 degrees-instrumentation, interpretation of the fusion-status should be based on structural and not on functional criteria. The modification of PLIF with cages compared to the use of only autologous spongiosa has the advantage of a high primary stability. Long-term studies are necessary to determine the implications of a radiographically evident uncertain fusion-status.

Bone Substitutes↗
PubMed2001

Radiographic characteristics on conventional radiographs after posterior lumbar interbody fusion: comparative study between radiotranslucent and radiopaque cages.

The problem of determining solidity of a fused spinal segment still remains. Our purpose is to evaluate radiographic findings after posterior lumbar interbody fusion (PLIF) with cages and estimate their relative value in judging fusion status. Radiographic follow-up was performed in patients after PLIF with cages of either radiotranslucent or radiopaque material. Conventional radiographs were obtained 6 weeks, 3 and 6 months, and then yearly after surgery for spinal instability for 64 patients. We differentiated between uncertain (increased density within the cage, increase of sclerotic endplates, and posterolateral fusion) and definite (trabecular continuous bone bridging within the implant and periimplant new bone formation with bridging of the intervertebral space) fusion signs. A fusion rate of 51.5% after 12 months, 61.4% after 24 months, 66.7% after 36 months, and 77.8% after 48 months postoperatively was found. We found only a slight, nonsignificant correlation between radiographic fusion and patient-assessed clinical outcome. There is evidence that radiographic fusion criteria occur in a specific chronologic order. The interpretation of fusion status is notably impaired by the use of radiopaque cages. Criteria to standardize the interpretation and evaluation of radiographic findings after PLIF are discussed.

Bone Resorption↗
PubMed2000

[Atlanto-axial instability presenting a rare complication in fibrous dysplasia - a case report].

Fibrous dysplasia, in either monostotic or poliostotic form rarely involves the cervical spine. Most of these lesions remain asymptomatic and are incidental radiographic findings. A symptomatic case of polyostotic fibrous dysplasia involving the first, second and third cervical vertebra with potentially serious consequences is presented. A 53-year old woman who had shown cervical myelopathy for about 3 month was diagnosed as having cervical dysplasia on the basis of plain x-ray and CT scanning. In addition, atlanto-axial instability causing clinical symptoms was detected. A dorsal stabilisation was performed using the DCS System.

Atlanto-Axial Joint↗