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Purpose:
Soft tissue balancing is of central importance to outcome following total knee arthroplasty (TKA). However, there are lack of data analysing the effect of tibial bone cut thickness on valgus laxity. A cadaveric study was undertaken to assess the biomechanical consequences of tibial resection depth on through range knee joint valgus stabil...
Contexts in source publication
Context 1
... force was applied 83 through a traction hook fixed to the lateral border of the tibia (to avoid rotation bias), 25cm distal to the joint 84 line, using one 4.5mm bicortical screw. The distal part of the femur was maintained by the leg-holding device 85 ( figure 1, A). The accuracy of the system is <1 mm for length measurement and <1° for angle measurement. ...
Context 2
... force was applied 83 through a traction hook fixed to the lateral border of the tibia (to avoid rotation bias), 25cm distal to the joint 84 line, using one 4.5mm bicortical screw. The distal part of the femur was maintained by the leg-holding device 85 ( figure 1, A). The accuracy of the system is <1 mm for length measurement and <1° for angle measurement. ...
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PurposeRevision constrained-condylar total knee arthroplasty (CCK-TKA) is often used to provide additional mechanical constraint after failure of a primary TKA. However, it is unknown how much this translates to a reliance on soft-tissue support. The aim of this study was therefore to compare the laxity of a native knee to the CCK-TKA implanted sta...
Background:
The transtibial tunnel technique achieves equal length reconstruction of the anterior cruciate ligament (ACL). This study aimed to investigate whether transtibial tunnel technique can achieve anatomical reconstruction of ACL.
Methods:
For 25 corpses, the anterior soft tissue of the knee joint was detached so that the ligamentous surf...
Citations
... Van Opstal et al. demonstrated that on average 67% of the PCL insertion was removed in routine primary knee arthroplasty, especially with increasing posterior slope 23,24 . Patients are also at risk of valgus instability in flexion when the tibia is cut more distally, as demonstrated by Sappey-Marinier et al. 25 . ...
Open reduction and internal fixation of extended lateral column tibial plateau fractures through a tibial condyle osteotomy
and limited arthrotomy with the use of free subchondral locking screws is a straightforward and safe technique. However,
these free subchondral screws are enclosed in the subchondral bone and therefore virtually impossible to remove after
bone healing. The question arises whether these free subchondral screws might hinder a future total knee arthroplasty.
In order to refute this, we retrospectively reviewed all surgically managed tibial plateau fractures in our tertiary center
during one year and assessed the number, position and configuration of these in situ subchondral screws and K-wires.
In addition, we performed a cadaver study, wherein we prepared 7 tibial plateaus for a total knee arthroplasty tibial
component placement with free subchondral screws in situ. In this experiment, we demonstrated that free subchondral
screws do not interfere with total knee arthroplasty, but they can increase operative time in some cases. We also provide
recommendations to avoid difficulties and potential complications.
... balancing is often achieved by re-cutting the tibia, with increasingly thicker polyethylene inserts being required. We have previously demonstrated that this approach for balancing leads to increased valgus laxity through an arc of flexion [33]. For this reason, in FA, the maximum alteration to joint line-height is set within the limits of ±3 mm, and when large gaps are present (for example, 21 mm), we adjust the depth of the cuts through a combination of femoral and tibial alignment adjustment. ...
... balancing is often achieved by re-cutting the tibia, with increasingly thicker polyethylene inserts being required. We have previously demonstrated that this approach for balancing leads to increased valgus laxity through an arc of flexion [33]. For this reason, in FA, the maximum alteration to joint line-height is set within the limits of ±3 mm, and when large gaps are present (for example, 21 mm), we adjust the depth of the cuts through a combination of femoral and tibial alignment adjustment. ...
Introduction:
Alignment techniques in total knee arthroplasty (TKA) continue to evolve. Functional alignment (FA) is a novel technique that utilizes robotic tools to deliver TKA with the aim of respecting individual anatomical variations. The purpose of this paper is to describe the rationale and technique of FA in the varus morphotype with the use of a robotic platform.
Rationale:
FA reproduces constitutional knee anatomy within quantifiable target ranges. The principles are founded on a comprehensive assessment and understanding of individual anatomical variations with the aim of delivering personalized TKA. The principles are functional pre-operative planning, reconstitution of native coronal alignment, restoration of dynamic sagittal alignment within 5° of neutral, maintenance of joint-line-obliquity and height, implant sizing to match anatomy and a joint that is balanced in flexion and extension through manipulation of implant positioning rather than soft tissue releases.
Technique:
An individualized plan is created from pre-operative imaging. Next, a reproducible and quantifiable method of soft tissue laxity assessment is performed in extension and flexion that accounts for individual variation in soft tissue laxity. A dynamic virtual 3D model of the joint and implant position that can be manipulated in all three planes is modified to achieve target gap measurements while maintaining the joint line phenotype and a final limb position within a defined coronal and sagittal range.
Conclusion:
Functional alignment is a novel knee arthroplasty technique that aims to restore constitutional bony alignment and balance the laxity of the soft tissues by placing and sizing implants in a manner that it respects the variations in individual anatomy. This paper presents the approach for the varus morphotype.
... Sappey-Marinier has demonstrated that an increased tibial resection depth is associated with significantly greater laxity in valgus between 30 and 90°of flexion, particularly with a tibial resection ! 14 mm [32]. Increasing the tibial resection could jeopardize the medial collateral ligament and could complicate TKA revision if required. ...
Traditionally in total knee arthroplasty (TKA), a post-operative neutral alignment was the gold standard. This principle has been contested as functional outcomes were found to be inconsistent. Analysis of limb alignment in the non-osteoarthritic population reveals variations from neutral alignment and consideration of a personalized or patient-specific alignment in TKA is challenging previous concepts. The aim of this review was to clarify the variations of current personalized alignments and to report their results. Current personalized approaches of alignment reported are: kinematic, inverse kinematic, restricted kinematic, and functional. The principle of “kinematic alignment” is knee resurfacing with restitution of pre-arthritic anatomy. The aim is to resurface the femur maintaining the native femoral joint line obliquity. The flexion and extension gaps are balanced with the tibial resection. The principle of the “inverse kinematic alignment” is to resurface the tibia with similar medial and lateral bone resections in order to keep the native tibial joint line obliquity. Gap balancing is performed by adjusting the femoral resections. To avoid reproducing extreme anatomical alignments there is “restricted kinematic alignment” which is a compromise between mechanical alignment and true kinematic alignment with a defined safe zone of alignment. Finally, there is the concept of “functional alignment” which is an evolution of kinematic alignment as enabling technology has progressed. This is obtained by manipulating alignment, bone resections, soft tissue releases, and/or implant positioning with a robotic-assisted system to optimize TKA function for a patient’s specific alignment, bone morphology, and soft tissue envelope. The aim of personalizing alignment is to restore native knee kinematics and improve functional outcomes after TKA. A long-term follow-up remains crucial to assess both outcomes and implant survivorship of these current concepts.
... posterior position increases the loads on the tibia [11]. Third, the limit to avoid prosthetic instability is probably 14-mm-deep tibial resection, from this point, it seems to increase valgus instability [12]. Fourth, a deep tibial resection may require a distalization of the joint line, resulting in a pseudopatella alta that increases the mechanical load on the patella, the risk of subluxation and alteration of the patellofemoral kinematics [3,13]. ...
Background:
Standard resections according to the TKR manufacturers can lead to unnecessary bone resections in some patients. The objective of this study was to determine in which patients is recommended to perform a minimal tibial resection (MTR) that could restore the joint line height (JLH).
Methods:
Navigation records of 108 consecutive posterior cruciate-substituting TKR performed by one surgeon were analyzed. Optimal tibial resection depth to restore the JLH (0 mm) was calculated by an algorithm. Postoperatively, the knees were distributed in two groups: those in which a MTR (depth ≤ 8 mm) would have been enough to restore the JLH and those in which a standard resection depth would have been necessary. ROC curves and Youden index were used to determine the cutoff point of the coronal and sagittal mechanical axis that predicted a MTR restoring the JLH. Multivariate analysis was used to identify independent factors associated with requiring an MTR.
Results:
A MTR could be required in 20 (18.5%) knees. In the ROC curve analyses, the cutoff points that best discriminated between minimal and standard tibial resection was ≤ 3° of varus and < 2° of flexion preoperative deformity. Multivariate analysis showed that female gender and preoperative flexion < 2° were significant predictors of requiring a MTR to restore JLH.
Conclusion:
A MTR with the JLH restoration could be possible in female patients with a preoperative sagittal deformity less than 2° of flexion. Preoperative coronal alignment had no influence to discriminate when a MTR is required.
Purpose:
The aim of this study was to report the long clinical outcomes after isolated MPFLr to treat recurrent patella instability.
Methods:
This was a single-centre study of patient's undergoing an isolated MPFLr between 2000 and 2011. All patients underwent reconstruction using hamstring autograft. Inclusion criteria were minimum 10-year follow-up, skeletally mature patients with more than 1 episode of patella dislocation who underwent MPFLr without an associated bony procedure.
Results:
A total of 54 knees were available for final analysis. Mean follow-up was 12.3 years (range 10-14). Mean age at surgery was 25 years. No patients had patellofemoral arthritis (PFA) prior to surgery. Preoperatively, mean Caton-Deschamps index (CDI) was 1.1 and mean tibial tubercle to trochlear groove (TT-TG) was 14.9 ± 2. (7;17). All patients had trochlear dysplasia according to the Dejour classification. At final follow-up mean Kujala score was 82.9 ± 15.3, mean IKDC score 78.3 ± 18.5 and mean Tegner score 4.0 ± 1.7. Unsatisfactory outcome as determined by a Kujala score <80 had higher CDI pre-operatively and comparatively more female patients, however neither factors reached significance. Thirty-three patients (66%) had no radiographic evidence of PFA, 15 had Iwano stage 1 (30%) and 2 (4%) had Iwano stage 2. At the final follow-up, four patients (7.4%) had recurrent instability requiring revision surgery.
Conclusion:
Isolated MPFLr with gracilis tendon autograft in appropriately selected patients is an effective long-term treatment for recurrent patellofemoral instability with low rates of recurrence. One-third of patients exhibit radiographic evidence of PFA more than 10 years after isolated MPFLr.
Level of evidence:
Case series; Level of evidence; 4.
