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C Stukenborg-Colsman

Publications and source records attributed to C Stukenborg-Colsman.

16 recordsLinked to original sources
PubMed2006

Experimental measurement of tibiofemoral contact area in a meniscectomized ovine model using a resistive pressure measuring sensor.

Animal models are necessary for the development and analysis of surgical techniques in meniscal surgery because they are the only means of preclinically determining the influence of biological factors such as healing processes and joint remodeling. Furthermore, little is known about the biomechanical effect of meniscectomy in sheep. The aim of the study was thus to investigate the efficacy of using a resistive pressure measuring sensor to quantify the effect of chronic meniscectomy in an ovine model. Twelve sheep were divided into two groups (n = 6): a sham operated control group (A), and a medially meniscectomized group (B). After six months, lower limb specimens were loaded with a joint-compressive force of 500 N during which the pressure measuring sensor was positioned underneath the meniscus to determine contact area, mean and peak contact pressure. A significant reduction in contact area of about 55% was observed in the meniscectomized knees compared to the controls. Peak contact pressure of the meniscectomized knees significantly increased an average of 260.4% compared to the control knees. Based on the results of this study, we conclude that the resistive pressure measuring sensors provide a means to experimentally measure tibiofemoral contact mechanics even in this relatively small (compared to human) animal model.

Animals↗
PubMed2005

[What effect does of obesity have on the outcome of total hip and knee arthroplasty. Review of the literature].

As the prevalence of obesity worldwide continues to rise, defining the relationship between obesity and arthroplasty outcomes becomes increasingly important. The effect of obesity on the outcome of total hip or knee arthroplasty has been reported to be variable. Some authors believe that a high body weight will lead to less than optimal arthroplasty outcomes, because increased body weight leads to increased stress across the components and an increased load on the surrounding bone. Although this should, in turn, lead to a higher incidence of aseptic loosening or prosthetic failure in obese patients, studies have suggested that the effect of increased body weight and arthroplasty outcome are not so straightforward. The lower activity level typically observed in obese patients may partially counter the negative effects of increased weight on the bone-prosthesis interface. Although results do not show significant differences in all studies, it appears that obesity has negative impact on the results of total hip and knee arthroplasty. Therefore, long-term studies using large sample sizes should be conducted. If significant differences are demonstrated, an altered course of treatment, such as having a patient lose weight before considering a total hip or knee arthroplasty, might be advocated.

Arthroplasty, Replacement, Hip↗
PubMed2005

[Navigator concept. Optimizing the procedure for navigated total knee arthroplasty].

BACKGROUND: This study addresses work sharing during navigation-assisted total knee arthroplasty. Specifically, the concept is introduced of a "navigator" assistant who operates the navigation system during surgery while the surgeon concentrates on the primary steps of surgery. METHODS: In a prospective study of 40 total knee arthroplasties, one group of patients was treated using the navigator concept, a second group was treated using a conventional navigation setup, and a third group was treated with conventional internal and external alignment jigs. Surgery time and outcome parameters were compared. RESULTS: Results show a significant difference in surgery time between the three groups. The conventional and navigator concept groups showed similar surgery times; however, the navigation group without navigation concept exhibited longer surgery time. CONCLUSIONS: The navigator concept represents a highly effective principle to minimize surgery time needed during navigated total knee arthroplasty.

Algorithms↗
PubMed2004

Effect of high tibial flexion osteotomy on cartilage pressure and joint kinematics: a biomechanical study in human cadaveric knees. Winner of the AGA-DonJoy Award 2004.

INTRODUCTION: Valgus high tibial osteotomy is an established treatment for unicompartmental varus osteoarthritis. However, only little is known about the effect of osteotomy in the sagittal plane on biomechanical parameters such as cartilage pressure and joint kinematics. This study investigated the effects of high tibial flexion osteotomy in a human cadaver model. MATERIALS AND METHODS: Seven fresh human cadaveric knees underwent an opening wedge osteotomy of the proximal tibia in the sagittal plane. The osteotomy was opened anteriorly, and the tibial slope of the specimen was increased gradually. An isokinetic flexion-extension motion was simulated in a kinematic knee simulator. The contact pressure and topographic pressure distribution in the medial joint space was recorded using an electronic pressure-sensitive film. Simultaneously the motion of the tibial plateau was analyzed three-dimensionally by an ultrasonic tracking system. The traction force to the quadriceps tendon which was applied by the simulator for extension of the joint was continuously measured. The experiments were carried out with intact ligaments and then after successively cutting the posterior and anterior cruciate ligaments. RESULTS: The results demonstrate that tibial flexion osteotomy leads to a significant alteration in pressure distribution on the tibial plateau. The tibiofemoral contact area and contact pressure was shifted anteriorly, which led to decompression of the posterior half of the plateau. Moreover, the increase in the slope resulted in a significant anterior and superior translation of the tibial plateau with respect to the femoral condyles. Posterior subluxation of the tibial head after cutting the posterior cruciate ligament was completely neutralized by the osteotomy. The increase in slope resulted in a significant higher quadriceps strength which was necessary for full knee extension. CONCLUSIONS: We conclude from these results that changes in tibial slope have a strong effect on cartilage pressure and kinematics of the knee. Therapeutically a flexion osteotomy may be used for decompression of the degenerated cartilage in the posterior part of the plateau, for example, after arthroscopic partial posterior meniscectomy. If a valgus osteotomy is combined with a flexion component of the proximal tibia, complex knee pathologies consisting of posteromedial cartilage damage and posterior and posterolateral instability can be addressed in one procedure, which facilitates a quicker rehabilitation of these patients.

Aged↗
PubMed2004

Quadriceps function after TKA--an in vitro study in a knee kinematic simulator.

OBJECTIVE: The purpose of this in vitro study was to investigate the amount of quadriceps force required to extend the knee during an isokinetic extension cycle before and after total knee arthroplasty. DESIGN: The magnitude of the extension torque used in simulating a constant moment extension exercise was derived from tests made using a dynamometer on patients who had received a total knee arthroplasty. Quadriceps force needed to extend the knee was measured. METHODS: Human knee specimens (n=8, mean age=65 SD 7 years, all male) were tested in a kinematic knee simulating machine untreated and after implantation of two different knee prosthesis. During simulation, a hydraulic cylinder applied sufficient force to the quadriceps tendon to produce an extension moment of 31 Nm about the knee. RESULTS: The quadriceps forces needed to extend the knee during the physiologic simulation reached levels as high as 1238.9 N (SD 46.6). After implantation the Interax-prosthesis, quadriceps force increased up to 13.9% (P=0.003), in conjunction with resurfacing of the patella 11.9% (P=0.01). With the LCS-prosthesis implanted, quadriceps force showed a somewhat smaller increase of up to 6.6% (P=0.007). RELEVANCE: The following study helps to clarify postoperative problems related to the extensor mechanisms of the knee after implantation of total knee arthroplasty.

Arthroplasty, Replacement, Knee↗
PubMed2003

[Dynamic in vitro measurement of pressure and movement with the LCS prosthetic system].

This study measured the femoral inlay pressure and the movement of mobile bearing inlays after implantation of the LCS knee prosthetic system (DePuy,Warsaw, USA). The prostheses were implanted in seven fresh frozen knee specimens. This system offered three different types of inlays [classic (CL), A/P glide (APG), and rotating platform (ROT)] with the same type of femoral component. A pressure-sensitive film (Tekscan,Boston, USA) was attached on the surface of the inlay.T he movement of the inlay was measured by an ultrasonic positioning system (Zebris, Isny,Germany). The specimens were fixed in a hydraulic knee apparatus simulating an isokinetic extension movement from 120 degrees flexion to full extension. The hydraulic cylinder that simulated the musculus quadriceps femoris extended up to 1200 N. The pressure measurement showed a peak pressure of 4.4+/-1.5 MPa (CL),3.6+/-1.0 MPa (APG),and 9.8+/-1.3 MPa (ROT). The mobile bearing inlays moved 1.4+/-2.7 mm (CL) and 2.9+/-5.8 mm (APG) from posterior to anterior during extension of the knee. During the extension the inlays rotated 0.8+/-2.6 degrees (CL), 0.9+/-5.2 degrees (APG), and 3.2+/-6.9 degrees (ROT) internally.

Biomechanical Phenomena↗
PubMed2003

[Dynamic in vitro measurement of retropatellar pressure after knee arthroplasty].

The purpose of this study was to examine the contact pressure between the patellofemoral interface of the physiologic, native, and prosthetic patella and the femoral component in total knee arthroplasty. An electronic sensor was used to measure contact pressure in five cadaver knees. The average peak contact pressure measured on the prosthetic patella was 9.8 MPa and was significantly higher than the physiologic and native patella. Average peak contact pressures increased with flexion. Although contact pressure reflects only a part of the dynamics of the patellofemoral articulation, these data support the selective retention of the native patella in total knee arthroplasty. Nevertheless, besides the indication for prosthetic replacement of the patella, design and operative techniques should also be part of the discussion.

Aged↗
PubMed2002

Relative motion of a mobile bearing inlay after total knee arthroplasty--dynamic in vitro study.

OBJECTIVE: The purpose of this study was to measure the in vitro range of motion of a mobile bearing inlay knee prosthesis under dynamic isokinetic loading conditions. Additionally, the effect on the range of motion of rotational malalignment of the tibia baseplate was determined. DESIGN: Specimens with implanted knee prostheses were mounted onto a custom built knee simulator. 3-D inlay movement was measured by an ultrasonic tracking system. BACKGROUND: More recent knee prostheses include mobile bearing inlays type designs. These systems are intended to allow higher conformity of the tibiofemoral joint and thereby decrease contact stress without decreasing the knee's range of motion. METHODS: Dynamic testing in the knee simulator mimicked both the speed and resulting moment of a knee isokinetic extension test. The tibia baseplate was first implanted with no rotational malalignment, followed by sequential internal and external rotation of upto 15 degrees. RESULTS: Correctly aligned, the inlay center moved 3.5 mm (SD, 1.5 mm) posterior during extension. With the tibia baseplate externally rotated more than 10 degrees the movement pattern changed. CONCLUSION: At up to 10 degrees of rotational malalignment the primary motion pattern of the mobile bearing is maintained. However, beyond 10 degrees unintended motion may occur. RELEVANCE: These test results correlate to radiographic measurements of in vivo movements of mobile bearing inlays showing "paradoxical" movement of the mobile inlay compared to physiologic meniscal movement.

Biomechanical Phenomena↗
PubMed2001

High tibial osteotomy versus unicompartmental joint replacement in unicompartmental knee joint osteoarthritis: 7-10-year follow-up prospective randomised study.

The clinical outcome of patients treated either by high tibial osteotomy or unicompartmental arthroplasty for medial unicompartmental osteoarthritis of the knee was compared in a prospective randomised study. In total, 32 patients received a high tibial osteotomy (HTO) and 28 patients a unicompartmental arthroplasty (UKA). More intra- and postoperative complications were observed after HTO. Patients were assessed at an average of 2.5 (1.6-5), 4.5 (3.6-7), and 7.5 years (6.6-10) after the operation. Using the Knee Society Score, 71% (15) of patients after osteotomy and 65% (13) after replacement had a knee score of excellent or good 7-10 years postoperatively. The Kaplan-Meier survival analysis 7-10 years postoperatively showed a survivorship of 77% for UKA and 60% for HTO. Although the unicompartmental prosthesis used in this series has not shown promising results, we conclude that with the advanced design of unicompartmental prosthesis today, UKA offers better long-term success.

Aged↗
PubMed2000

[Knee endoprosthesis: biomechanical requirements and consequences].

The experiments described herein permitted the dynamic in vitro measurement of the mechanical efficiency of the quadriceps muscle, both before and after total knee arthroplasty (TKA). The measurement of tibiofemoral pressure on fixed and mobile polyethylene inlays, as well as the movement of mobile inlays, is described. The Interax TKA system was implanted in 8 fresh frozen knee cadavers which were then mounted onto a knee-simulating machine. An isokinetic extension motion was simulated by extending the knee specimens under a constant extension torque of 31 Nm. The quadriceps muscle force required for this motion was not found to increase after implantation of the prostheses. Pressure on the mobile inlay was 60% lower than that measured on the fixed inlay. A 4-mm posterior migration of the mobile inlay on the tibial base plate was observed, with no motion of the inlay femoral component contact surface, which migrated posteriorly in the fixed bearing prosthesis. Thus, instead of moving posteriorly, the mobile inlay femoral component contact area remained at the center of the inlay during the entire extension motion.

Aged↗
PubMed2000

[Knee endoprosthesis: clinical aspects].

Despite improvements in component design, instruments, and operative technique, there remains a significant complication and failure rate in total knee arthroplasty (TKA). Revision TKA accounts for every tenth operation in TKA. From June 1991 to June 1994, 209 TKAs (182 patients) were performed. Of these, 73% were uncemented, 11.2% cemented, and 15.8% hybrid. The patella was resurfaced in 96% with a cemented polyethylene or an uncemented metal-backed patella component. Follow-up showed significant improvement in knee and function scores 1 and 5-7 years postoperatively. Of the patients, 77% showed no general and 80% no local postoperative complications. Overall, 42 revisions (41 patients) were performed during the 7-year follow-up. Revision surgery was necessary because of aseptic loosening (8.1%), polyethylene wear (4.8%), complications of the extensor mechanism (2.4%), traumatic periprosthetic fractures or knee luxation (1.4%), and septic loosening (3.3%). Further improvements of polyethylene will reduce polyethylene wear. Uncemented fixation of this prosthesis can only be recommended with hydroxyapatite coating.

Adult↗
PubMed1998

[Not Available].

Explore the source record for details and available documents.

Journal Article↗
PubMedDate not supplied

[Resection of the tendon of the peroneal brevis muscle in "clicking" peroneal tendons--a report of 3 cases].

INTRODUCTION: The following article deals with the problem of peroneal clicking. This means a clicking of the two peroneal tendons against each other. It has to be differentiated from peroneal tendon dislocation or subluxation. METHOD: In three patients, a peroneal click was found without symptoms of dislocation of the tendons over the fibula. In these cases the indication for resection of the peroneal brevis tendon was seen. RESULTS: Postoperatively no pain, swelling, and peroneal click were present. The partial loss of function of the peroneal brevis tendon seems to be negligible. CONCLUSION: In case of pain and swelling over the peroneal tendons, peroneal clicking should be included in a differential diagnosis. Resection of the peroneal brevis tendon is an effective treatment in these cases.

Adult↗
PubMedDate not supplied

[Valgus tibial head reconstruction, monocondylar sled prosthesis or bicondylar gliding surface replacement in therapy of medial gonarthrosis--a cost analysis].

AIM: Three to a certain extent competing methods for the treatment of unicompartmental osteoarthritis of the knee are compared regarding the costs they cause. These methods comprise the high tibial valgus osteotomy (HTO), the unicompartmental knee arthroplasty (UKA), and the total knee arthroplasty (TKA). METHODS: We compared the in-patient costs and out-patient costs of 20 patients (drawn by lot) in each group who received one of the above-named operative methods at our hospital between 1988 and 1993. The results were extrapolated according to the expected survival rate of the applied method. RESULTS: The average total costs of patients who received a HTO were 9.487,-; for the unicompartmental arthroplasty the average cost were 11.687,-; the implantation of a TKA resulted in average costs of 16.940,-. All operative procedures exceeded a particular global amount, the socalled "Fallpauschale". CONCLUSION: Regarding the total costs that arise for the operative treatment of the degenerative arthritis of the knee, the HTO (with or without hardware removal) proves to be the cheapest of the applied methods. Projecting the results on the survival rate of each treatment method, no statistically significant differences could be recognized between the three operative procedures.

Adult↗