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Lateral view of knee with a periprosthetic fracture of a non-replaced patella following total knee arthroplasty that has required internal fixation
Source publication
Total knee arthroplasty is a common operation for treating patients with end-stage knee osteoarthritis and generally has a good outcome. There are several complications that may necessitate revision of the implants. Patella-related complications are difficult to treat, and their consequences impact the longevity of the implanted joint and functiona...
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Objective
Constraint is defined as the effect of elements knee implant designs that provide the stability needed in the presence of a deficient soft tissue envelope. The prosthesis with the minimal acceptable constraint generates maximal functional outcome is the general dictum. Varus valgus constrained (VVC) and rotating hinge knees(RHK) are impla...
Citations
... The incidence of patellofemoral complications following total knee arthroplasty (TKA) is reported between 2% and 20% [2], regardless of whether the patella is resurfaced or not [9], and these complications are deemed to be causes for revision in 7.7% of TKAs according to the Australian joint registry [37]. Moreover, some authors estimate that nearly 50% of poor outcomes following TKA could be attributed to patellofemoral complications [19]. ...
... Patellar maltracking and patellofemoral joint complications are named among the common complications of TKR [19]. These complications were proved to be the consequences of improper femoral component rotation [20]. ...
Background: Anterior knee pain (AKP) is one of the reasons for dissatisfaction after total knee replacement (TKR). It may result from patellofemoral joint dysfunction, caused by improper rotation of implant components. The aim of this study was to analyze patella positioning in patients after standard measured resection TKR and TKR with a use of a dynamic tensioner, and to assess the frequency of AKP, range of motion (ROM), and patient-reported outcome measures 6 weeks and 3 months postoperatively. Methods: The study consisted of 127 patients who underwent TKR. Eighty-nine of them treated with use of the dynamic tensioner FUZION formed the study group; the remainder formed the control group. All participants received cemented PERSONA MC without patella resurfacing. All patients had a standard anteroposterior, lateral weight-bearing, long-leg view X-ray and computed tomography examination in 30°of knee flexion following the procedure. Results: There were no significant differences between the study and the control groups regarding: posterior condylar axis (PCA)-patella angle, surgical transepicondylar axis (sTEA)-patella angle, PCA-sTEA angle, deviation from 90°in PCA-patella, sTEA-patella and PCA-sTEA angles. No significant difference was found in a ratio of obtaining PCA-patella angle deviation of more than 3°. Regarding clinical parameters, statistically and questionablly clinically significant difference in favor of the Study Group was found in Forgotten Joint Score 6 weeks and 3 months post-operativley and ROM 6 weeks post-operatively. However, such difference was not found by analyzing ROM 3 months post-operatively, AKP and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. Conclusion: Compared with the standard 3°of femoral component external rotation, use of a dynamic tensioner does not allow for more accurate restoration of the patellar facet position with reference to the PCA.
... Possible disadvantages that have been described include the induction of higher quadriceps requirements as well as more pronounced alterations in native tibiofemoral kinematics and load transfer [9,15,20,33]. The most alarming concern that has been raised is the heightened potential to induce patellofemoral maltracking, which remains one of the most frequent complications after TKA and an important contributor to patient dissatisfaction [2,5,27]. Despite the aforementioned dangers associated with femoral component malrotation, an article by Flury et al. shows no influence of excessive femoral torsion on patellofemoral pain and instability when the overall alignment remains neutral and denervation of the patella has occurred [8]. ...
Purpose
The purpose of this study was to investigate the influence of increasing the tibial boundaries in functional alignment on femoral component orientation in total knee arthroplasty (TKA).
Methods
A retrospective review of a database of robotic‐assisted TKAs using a digital joint tensioning device was performed (BalanceBot®; Corin). A total of 692 TKAs with correctable deformity were included. Functional alignment with a tibia‐first balancing technique was simulated by performing an anatomic tibial resection to recreate the native medial proximal tibial angle within certain boundaries (A, 87–90°; B, 86–90°; C, 84–92°), while accounting for wear. After balancing the knee, the resulting amount of femoral component outliers in the coronal and axial plane was calculated for each group and correlated to the coronal plane alignment of the knee (CPAK) classification.
Results
The proportion of knees with high femoral component varus (>96°) or valgus (<87°) alignment increased from 24.5% ( n = 170) in group A to 26.5% ( n = 183) in group B and 34.2% ( n = 237) in group C ( p < 0.05). Similarly, more knees with high femoral component external rotation (>6°) or internal rotation (>3°) were identified in group C (33.4%, n = 231) than in group B (23.7%, n = 164) and A (18.4%, n = 127) ( p < 0.05). There was a statistically significant ( p < 0.01) overall increase in knees with both femoral component valgus <87° and internal rotation >3° from group A (4.0%, n = 28) to B (7.7%, n = 53) and C (15.8%, n = 109), with CPAK type I and II showing a 12.9‐ and 2.9‐fold increase, respectively.
Conclusion
Extending the tibial boundaries when using functional alignment with a tibia‐first balancing technique in TKA leads to a statistically significant higher percentage of knees with a valgus lateral distal femoral angle < 87° and >3° internal rotation of the femoral component, especially in CPAK type I and II.
Level of Evidence
Level IV.
... The authors of the study point out that creating a combination of excessive valgus and internal rotation on the femoral component increases the risk of patellofemoral maltracking [59]. This is a common reason for dissatisfaction after TKA [60,61]. In addition, increasing internal rotation to the femoral component can lead to changes in tibiofemoral kinematics and higher quadriceps requirements [62,63]. ...
Citation: Sterneder, C.M.; Faschingbauer, M.; Haralambiev, L.; Kasparek, M.F.; Boettner, F. Why Kinematic Alignment Makes Little Sense in Valgus Osteoarthritis of the Knee: A Narrative Review. J. Clin. Med. 2024, 13, 1302. https://doi. Abstract: There is a debate about the best alignment strategies in total knee arthroplasty (TKA). Mechanical alignment (MA) targets in combination with necessary soft tissue releases are the gold standard for TKA in end-stage valgus osteoarthritis. Some authors propagate kinematic alignment (KA) with the aim of restoring the patient's native alignment and minimizing the need for soft tissue releases. Our previous studies showed that MA with standardized soft tissue release produces reproducible results, and that the preoperative phenotype does not influence the results of patients with valgus osteoarthritis. These data suggest that there is no functional advantage to preserving valgus alignment in patients with valgus osteoarthritis. Many patients with valgus osteoarthritis present with a compromised medial collateral ligament and leaving the knee in valgus could increase the risk of secondary instability. The current literature supports MA TKA with soft tissue release as the gold standard. While using more sophisticated enabling technologies like robotic surgery might allow for aiming for very slight (1-2 •) valgus alignment on the femoral side, any valgus alignment outside this range should be avoided. This review paper summarizes our current knowledge on the surgical techniques of TKA in patients with valgus osteoarthritis.
... Post-operative knee pain was identified as a cause of Extended author information available on the last page of the article dissatisfaction in both resurfaced and non-resurfaced patella patients and was considered unrelated to the patella cartilage condition [6,7]. Common causes of anterior knee pain were identified as patellofemoral complications, including patellofemoral maltracking, aseptic loosening, fracture of the patella, and avascular necrosis [8][9][10][11]. These complications are the second most common reason for revision surgery after TKA [12][13][14]. ...
Introduction
The effect of post-operative patella tilt on functional outcomes after total knee arthroplasty remains unclear. Our study aimed to analyze the relationship of post-operative patellar tilt with functional outcome scores after total knee arthroplasty.
Materials and Methods
Patient data were retrieved from our institution’s prospectively maintained total knee arthroplasty. Three hundred three patients who underwent unilateral TKA from Jan 2012 to March 2017 were included in the study. After excluding patients with incomplete and lost follow-up data, 213 patients were analyzed. Radiographs of pre-operative and post-operative skyline views were used for patella tilt and patella displacement measurement at pre-op, post-op 1 year, and post-op 2 years. Three functional outcome scoring systems, SF-36, KSS, and WOMAC, were applied for function evaluation at different post-operative time points. Patients were divided into three subgroups according to the patella tilt, which includes less than 5°, 5.1–10°, and more than 10°. Statistical analysis was done to identify the relationship between patella tilt and functional outcomes.
Results
Mean post-operative patella tilt was significantly lower than the mean pre-operative patella tilt (3.35 ± 3.91 vs. 5.65 ± 4.41, p < 0.001). There was no significant difference in patella displacement among pre- and post-operative status. KSS functional score was significantly poor at post-op 1 year and KSS objective score at post-op 2 years in patients with more than 10° patella tilt. SF-36 and WOMAC were not significantly different among the groups. There was no significant difference in post-operative function between non-resurfaced and resurfaced patella patients evaluated with three scoring systems.
Conclusion
We have found significantly less post-operative patella tilt after TKA than pre-operative patella tilt with or without patella resurfacing. Increased post-operative patella tilt of more than 10° can affect specific functional outcomes. Patella resurfacing does not affect the post-operative functional outcome compared to non-resurfacing of the patella post-op 2 years.
Level of Evidence
III.
... Patellar issues now represent approximately 2-20% of all TKA complications. Notably, they have been identified as major causes of severe anterior knee pain and are significant contributors to the necessity for revision surgeries [7][8][9]. Patellar periprosthetic fractures (PPFs), after femoral periprosthetic fractures, constitute the second most frequent type of TKA periprosthetic fracture. These fractures occur in both unresurfaced and resurfaced patellae [10]. ...
... Patellofemoral complications following TKA account for an incidence of up to 20% of TKAs, rendering them a primary indication for revision surgeries [8,9,21]. Periprosthetic patellar fractures constitute a relatively rare complication with a prevalence varying between 0.2% and 21%, making them the second most frequent TKA periprosthetic fracture after the femoral supracondylar periprosthetic fractures [13,22,23]. ...
... A mean time from TKA to fracture occurrence of 18 months has been reported by Chalidis et al. [13]. Only less than half of the patients report a recent traumatic activity [8]. Furthermore, revision surgeries have been accused of a sharp increase in the incidence of PPFs compared to PPFs following primary TKAs [12,25,26]. ...
The management and underlying causes of patellar periprosthetic fractures (PPF) after total knee arthroplasty (TKA) constitute an issue of growing importance given the rising frequency of these procedures. Patella periprosthetic fractures, though relatively rare, pose significant challenges and are a frequent indication for revision surgeries. Despite a decrease in overall incidence, PPFs remain the second most common type of periprosthetic fractures after TKA. Several factors have been identified and associated with patient-specific factors, surgical technique errors, and implant-related causes. Currently extensor apparatus integrity, bone stock, and component loosening are the major concerns and indications for the selective treatment approach. In this study, a thorough review of the existing literature was performed summarizing the epidemiology, clinical manifestation, treatment approach, and functional outcome of PPF. This review aims to underline the significance of such predisposing factors, point out the severity of PPF, and offer insights into the optimal intra- and post-operative management of the patella.
... Possible patellofemoral complications after total knee arthroplasty (TKA) are many and can be categorized into bone-related and soft tissue-related [1]. Bone-related complications include aseptic loosening, periprosthetic fracture, and bone loss, whereas soft tissuerelated complications include patellar instability, patellar clunk, and extensor mechanism failure. ...
... Under-stuffing decreases the moment arm of the quadriceps muscle force, thus increasing the quadriceps force needed to develop an extension moment and increasing the patellofemoral joint compression force. This increase in the joint compression force could cause anterior knee pain, a common complication with patellar resurfacing [1]. However, overstuffing the prosthetic patellofemoral joint should be avoided, since this can lead to other complications such as decreased flexion [17] and lateral patellar maltracking due to tightening of the lateral retinaculum with a concomitant increased risk of lateral patellar subluxation [23,24]. ...
... This is typical of most femoral components where the groove on the anterior flange starts well proximal to the groove on the native femur [7,13,14,18,25,26]. This extension of the anterior flange and groove would promote early engagement of the patella with the groove, and a more lateral location of the groove would avoid a tendency for lateral patellar subluxation, particularly in valgus knees with large Q-angles, which is a relatively common complication [1,27,28]. ...
Because kinematic alignment (KA) aligns femoral components in greater valgus and with less external rotation than mechanical alignment (MA), the trochlear groove of an MA design used in KA is medialized, which can lead to complications. Hence, a KA design has emerged. In this study, our primary objective was to quantify differences in trochlear morphology between the KA design and the MA design from which the KA design evolved. The KA and MA designs were aligned in KA on ten 3D femur-cartilage models. Dependent variables describing the morphology of the trochlea along the anterior flange, which extends proximal to the native trochlea, and along the arc length of the native trochlea, were determined, as was flange coverage. Along the anterior flange, the KA groove was significantly lateral proximally by 10 mm and was significantly wider proximally by 5 mm compared to the MA design (p < 0.0001). Along the arc length of the native trochlea, the KA groove was significantly lateral to the MA design by 4.3 mm proximally (p ≤ 0.0001) and was significantly wider proximally by 19 mm than the MA design. The KA design reduced lateral under-coverage of the flange from 4 mm to 2 mm (p < 0.0001). The KA design potentially mitigates risk of patellofemoral complications by lateralizing and widening the groove to avoid medializing the patella for wide variations in the lateral distal femoral angle, and by widening the flange laterally to reduce under-coverage. This information enables clinicians to make informed decisions regarding use of the KA design.
... Tibial rotation during everyday activities is an essential descriptor of knee kinematics. Moreover, restoring native internal tibial rotation during flexion provides the kinematic benefit of decreasing the Q-angle, which might reduce the risks of patellar tilt, lateral patellar displacement, and anterior knee pain [2,3]. ...
Purpose
In total knee arthroplasty (TKA) with posterior cruciate ligament (PCL) retention, the medial and lateral insert conformity that restores in vivo native (i.e., healthy) knee tibial rotation and high function without causing stiffness is unknown. The purpose was to determine whether a ball-in-socket (B-in-S) medially conforming (MC) and flat lateral insert implanted with unrestricted kinematic alignment (KA) TKA and PCL retention restores tibial rotation to native.
Methods
One group of 25 patients underwent unrestricted KA TKA with manual instruments. Another group of 25 patients had native knees. Single-plane fluoroscopy imaged each knee while patients performed step-up and chair rise activities. Following 3D model-to-2D image registration, anterior–posterior (A-P) positions of the femoral condyles were determined. Changes in A-P positions with flexion were used to determine tibial rotation.
Results
At maximum flexion, mean tibial rotations of KA TKA knees were comparable to native knees (Step up: 12.3° ± 4.4° vs. 13.1° ± 12.0°, p = 0.783; Chair Rise: 12.7° ± 6.2° vs. 12.6° ± 9.5º, p = 0.941). However, paths of rotation differed in that screw home motion was less evident in KA TKA knees. At 8 months follow-up, the median Forgotten Joint Score was 69 points (range 65 to 85), the median Oxford Knee Score was 43 points (range 40 to 46), and mean knee flexion was 127º ± 8°.
Conclusions
The ball-in-socket medial, flat lateral insert and PCL retention implanted with unrestricted KA TKA restored in vivo native knee tibial rotation at maximum flexion for each activity and high function without stiffness. Providing high A-P stability, this implant design might benefit patients desiring to return to demanding work and recreational activities.
Level of evidence
Therapeutic – Level II.
... 4,5 Recurrent patellar instability occurs in approximately 1% of knees after total knee arthroplasty and accounts for up to 20% of postarthroplasty complications, commonly requiring surgical revision. [6][7][8][9] Risk factors for recurrent instability after arthroplasty include component malpositioning and/or damage to the medial soft-tissue structures owing to a medial parapatellar approach. [10][11][12] Current treatment options include medial reefing, which has been reported to be 82% effective in avoiding recurrent dislocation but is nonanatomic in young individuals. ...
Technique Video
Video 1
The patient is placed in the supine position. During diagnostic arthroscopy, the attenuated previously reconstructed medial patellofemoral ligament (MPFL) is visualized, in addition to significant scar tissue from instability and inflammation. The scar tissue is resected using a shaver (0-5 seconds). Diagnostic arthroscopy reveals lateral alignment of the patellofemoral arthroplasty before stabilization via MPFL reconstruction (6-8 seconds). The intended location for the femoral tunnel is measured and identified as the intersection between the Blumensaat line and the posterior cortex of the femur (9-19 seconds). Arthroscopic-assisted tunneling between layers 2 and 3 of the medial knee ensures extra-articular placement of the graft (19-23 seconds). Two all-suture anchors are placed in the patella. The first is placed at the superior portion of the superior one-third of the patella, and the second is placed 10 mm distally, still in the superior one-third of the patella (24-45 seconds). Anatomic reduction with perfect tensioning that allows 25% lateral translation is confirmed to avoid over-tightening (45-51 seconds). After appropriate tensioning is confirmed, the excess graft is resected with a shaver and arthroscopic cautery. Graft tension is confirmed by viewing the patellofemoral joint, which reveals restored anatomic alignment (52-58 seconds).
... Patella-related complications are quite common in TKA [5,6]. Despite improvements in the design of the implants, these complications are responsible for 10% of all TKA revisions [7,8]. ...
... Another critical complication is patellofemoral instability, which varies from 1 to 20% of all patellar complications [5,11,12]. Intraoperative detection of this condition results in the lateral release of the patellar retinaculum in up to 45% of cases [13,14]. Lateral release significantly increases the chance of the lateral genicular arteries injury and consequently may lead to iatrogenic devascularization of the patella [15,16]. ...
In this study, we evaluated the possibility of precise intraoperative localization of the lateral genicular arteries by an orthopaedic surgeon using the transillumination method.
Twelve patients underwent cemented TKA with patella-friendly Zimmer Biomet NexGen Legacy Posterior Stabilized prostheses (without patellar resurfacing), seven right knees and five left knees. The mean age of patients in the study group was 66.636 ± 7.003 years. The minimal follow-up period was 13 months (mean—16.363 ± 2.5 months). Functional outcomes were assessed using Knee Society and a specific patellar questionnaire—Kujala Score. Intraoperative detection of insufficient patellar stability and/or patellar maltracking was based on the no-thumb technique. In pre- and postoperative period X-ray investigation, standard standing X-ray and Merchant view were used to evaluate implant position and patellofemoral congruency.
In this study, ten out of twelve knee joints (83.3%) had at least one artery visible by the proposed method in the lateral parapatellar area. Five out of ten knee joints had more than one artery that could be visualized and identified as an arterial vessel. Postoperative Knee Society Score showed significant improvement from a mean 51.181 ± 3.868 to a mean 88.727 ± 3.663. Mean hospital length of stay is 8.545 ± 1.863 days. X-ray assessment using standard anteroposterior, lateral, and Merchant skyline views showed appropriate implant positioning and patellofemoral congruency. The mean Kujala Score in the postoperative period (3 and 6 months) was 67.3 ± 6.75 and 75.6 ± 6.42, respectively.
Using the proposed transillumination method can help preserve the lateral blood supply to the patella and to avoid devascularized patella-related complications.
Retrospectively registered on 5 of May 2023, Registration number – 3/3-1757.
