Methode zur In-vivo-Messung des intraossären Druckes an der Patella - In Vivo Measurement of the Intra-osseous Pressure of the Human Patella

Hauf, W.; Mittlmeier, Thomas; Hagena, F.-W.; Plitz, W.

doi:10.1515/bmte.1992.37.11.263

Cited by 4 publications

(5 citation statements)

References 16 publications

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“…Especially on the ridge there was a highly significant increase of the retropatellar pressure of about 109% in maximum flexion after TKA compared to natural knee. This increasing patellofemoral contact forces might lead to anterior knee pain in vivo [9,11-13]. Interesting is that with higher flexion grades the central retropatellar pressure increases in TKA whereas in natural knee central retropatellar pressure is constantly decreasing (Figure 7).…”

Section: Discussionmentioning

confidence: 99%

“…Regarding anterior knee pain several authors emphasize that the postoperative outcome is rather influenced by femoral component design than by retropatellar resurfacing [7,9,10]. It is assumed that excessive postoperative retropatellar pressure contributes to a great extent to postoperative patella problems [9,11-13]. In vitro studies with cadaver knees are a successful method to analyze this pressure distribution [12,14], and were also used to investigate retropatellar contact patterns in this study.…”

Section: Introductionmentioning

confidence: 99%

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Patellofemoral contact patterns before and after total knee arthroplasty: an in vitro measurement

et al. 2013

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BackgroundPatellofemoral complications are one of the main problems after Total Knee Arthroplasty (TKA). Retropatellar pressure distribution after TKA can contribute to these symptoms. Therefore we evaluated retropatellar pressure distribution subdivided on the ridge, medial and lateral surface on non-resurfaced patella before and after TKA. Additionally, we analyzed axial femorotibial rotation and quadriceps load before and after TKA.MethodsSeven fresh frozen cadaver knees were tested in a force controlled knee rig before and after TKA (Aesculap, Tuttlingen, Germany, Columbus CR) while isokinetic flexing the knee from 20° to 120° under weight bearing. Ridge, medial and lateral retropatellar surface were defined and pressure distribution was dynamically measured while quadriceps muscles and hamstring forces were applied. Aside axial femorotibial rotation and quadriceps load was recorded.ResultsThere was a significant change of patella pressure distribution before and after TKA (p = 0.004). In physiological knees pressure distribution on medial and lateral retropatellar surface was similar. After TKA the ridge of the patella was especially in higher flexion grades strongly loaded (6.09 +/−1.31 MPa) compared to the natural knee (2.92 +/−1.15 MPa, p < 0.0001). Axial femorotibial rotation showed typical internal rotation with increasing flexion both before and after TKA, but postoperatively it was significantly lower. The average amount of axial rotation was 3.5° before and after TKA 1.3° (p = 0.001). Mean quadriceps loading after implantation of knee prosthesis did not change significantly (575 N ±60 N in natural knee and after TKA 607 N ±96 N; p = 0.28).ConclusionsThe increased retropatellar pressure especially on the ridge may be one important reason for anterior knee pain after TKA. The trochlea of the femoral component might highly influence the pressure distribution of the non-resurfaced retropatellar surface. Additionally, lower axial femorotibial rotation after TKA might lead to patella maltracking. Changing the design of the prosthesis or a special way of patella shaping might increase the conformity of the patella to trochlea to maintain natural contact patterns.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Patellofemoral contact patterns before and after total knee arthroplasty: an in vitro measurement

et al. 2013

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“…Anterior knee pain remains a major problem in TKA, and the retropatellar pressure that seems to be responsible [19, 29, 36, 50, 51] for a part of the pain is influenced by the internal and external rotation of the femoral component [2, 5, 11–13, 38, 42, 46]. Surgeons often attempt to modify the kinematic environment by aligning the femoral component; unfortunately, it is not possible to restore patellofemoral and tibiofemoral conditions simply by rotating the femoral component, even if a link between these joints seems obvious [39].…”

Section: Discussionmentioning

confidence: 99%

“…In an uninjured knee, the trochlea is the guide rail for the patella, capturing the patella starting at 30° of flexion [1]. TKA changes the relevant kinematics and forces, especially for the retropatellar joint, resulting in complications as observed in various studies [9, 19, 29, 32, 36, 39, 50, 51].…”

Section: Introductionmentioning

confidence: 99%

TKA design-integrated trochlea groove rotation reduces patellofemoral pressure

Woiczinski

Kistler

Schröder

et al. 2018

Knee Surg Sports Traumatol Arthrosc

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PurposeTotal knee arthroplasty (TKA) leaves 11–25% of the patients unsatisfied, and patellofemoral joint pain is one cause. This study aimed to compare the differences between kinematics and load transfer in the same knee with axial internal/external rotation of the femoral component (CoRo) versus a separate axial internal/external trochlear groove rotation (TrRo) which is included in the TKA trochlea design. MethodsA validated weight‐bearing finite element model with modifications of the TKA axial femoral component rotation (CoRo) and a modified trochlear rotation (TrRo) was calculated and analysed. ResultsCompared to the neutrally implanted TKA at 105° of flexion, a 6° external rotation of the trochlear groove reduced the retropatellar stress by 7%, whereas a 3° internal trochlear groove rotation increased the retropatellar stress by 7%. With femoral component rotation, the tibia inlay stress of 6.7 MPa at 60° of flexion was two times higher both with a 3° internal component rotation and a 6° external rotation. ConclusionThese results demonstrate in the tested TKA design that a trochlear groove rotation can reduce retropatellar stress. Additionally, during the TKA operation, the surgeon should be aware of the significant influence of axial femoral component rotation on mechanical inlay stress during flexion and of the fact that even small changes in the patellofemoral joint may influence the tibiofemoral joint. These results support that an external rotation of the femoral component should be preferred in TKA to avoid anterior knee pain. Furthermore, new developed TKA designs should integrate an externally rotated trochlea groove.

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“…Nearly one-fifth of the patients are unsatisfied after primary total knee arthroplasty (TKA) [ 1 ]. An extensive part of patients complain about pain in the anterior knee joint, which should be associated, amongst other things, with an increased retropatellar pressure [ 2 – 4 ]. Instabilities, subrespectively, luxation, and fractures of the patella after implantation are further complications and reasons for revision [ 5 – 9 ].…”

Section: Introductionmentioning

confidence: 99%

Rapid Prototyping forIn VitroKnee Rig Investigations of Prosthetized Knee Biomechanics: Comparison with Cobalt-Chromium Alloy Implant Material

Schröder¹,

Steinbrück²,

Müller³

et al. 2015

BioMed Research International

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Retropatellar complications after total knee arthroplasty (TKA) such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material differences may further influence results. This pilot study aims at validating the use of prostheses made of photopolymerized rapid prototype material (RPM) by measuring the sliding friction with a ring-on-disc setup as well as knee kinematics and retropatellar pressure on a knee rig. Cobalt-chromium alloy (standard prosthesis material, SPM) prostheses served as validation standard. Friction coefficients between these materials and polytetrafluoroethylene (PTFE) were additionally tested as this latter material is commonly used to protect pressure sensors in experiments. No statistical differences were found between friction coefficients of both materials to PTFE. UHMWPE shows higher friction coefficient at low axial loads for RPM, a difference that disappears at higher load. No measurable statistical differences were found in knee kinematics and retropatellar pressure distribution. This suggests that using polymer prototypes may be a valid alternative to original components for in vitro TKA studies and future investigations on knee biomechanics.

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Methode zur In-vivo-Messung des intraossären Druckes an der Patella - In Vivo Measurement of the Intra-osseous Pressure of the Human Patella

Cited by 4 publications

References 16 publications

Patellofemoral contact patterns before and after total knee arthroplasty: an in vitro measurement

Patellofemoral contact patterns before and after total knee arthroplasty: an in vitro measurement

TKA design-integrated trochlea groove rotation reduces patellofemoral pressure

Rapid Prototyping forIn VitroKnee Rig Investigations of Prosthetized Knee Biomechanics: Comparison with Cobalt-Chromium Alloy Implant Material

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