Personalisation and customisation in total knee arthroplasty: the paradox of custom knee implants

Saffarini, Mo; Hirschmann, Michael T.; Bonnin, Michel

doi:10.1007/s00167-023-07385-0

Cited by 12 publications

(10 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Over the last decades, the gold standard 'mechanical alignment', a 'one size fits all' alignment technique aiming for neutral femoral and tibial mechanical axes and off the shelf implants were used. With more personalised strategies, knee surgeons have moved away from one systematic standard to new standards in alignment [16,17]. However, individual normality has still not been defined.…”

Section: Introductionmentioning

confidence: 99%

Definition of normal, neutral, deviant and aberrant coronal knee alignment for total knee arthroplasty

Hirschmann,

Khan,

Sava

et al. 2024

Knee surg. sports traumatol. arthrosc.

Self Cite

View full text Add to dashboard Cite

PurposeOne of the most pertinent questions in total knee arthroplasty (TKA) is: what could be considered normal coronal alignment? This study aims to define normal, neutral, deviant and aberrant coronal alignment using large data from a computed tomography (CT)‐scan database and previously published phenotypes.MethodsCoronal alignment parameters from 11,191 knee osteoarthritis (OA) patients were measured based on three dimensional reconstructed CT data using a validated planning software. Based on these measurements, patients' coronal alignment was phenotyped according to the functional knee phenotype concept. These phenotypes represent an alignment variation of the overall hip knee ankle angle (HKA), femoral mechanical angle (FMA) and tibial mechanical angle (TMA). Each phenotype is defined by a specific mean and covers a range of ±1.5° from this mean. Coronal alignment is classified as normal, neutral, deviant and aberrant based on distribution frequency. Mean values and distribution among the phenotypes are presented and compared between two populations (OA patients in this study and non‐OA patients from a previously published study).ResultsThe arithmetic HKA (aHKA), combined normalised data of FMA and TMA, showed that 36.0% of knees were neutral within ±1 SD from the mean in both angles, 44.3% had either a TMA or a FMA within ±1–2 SD (normally aligned), 15.3% of the patients were deviant within ±2–3 SD and only 4.4% of them had an aberrant alignment (±3–4 SD in 3.4% and >4 SD in 1.0% of the patients respectively). However, combining the normalised data of HKA, FMA and TMA, 15.4% of patients were neutral in all three angles, 39.7% were at least normal, 27.7% had at least one deviant angle and 17.2% had at least one aberrant angle. For HKA, the males exhibited 1° varus and females were neutral. For FMA, the females exhibited 0.7° more valgus in mean than males and grew 1.8° per category (males grew 2.1° per category). For TMA, the males exhibited 1.3° more varus than females and both grew 2.3° and 2.4° (females) per category. Normal coronal alignment was 179.2° ± 2.8–5.6° (males) and 180.5 > ± 2.8–5.6° (females) for HKA, 93.1 > ± 2.1–4.2° (males) and 93.8 > ± 1.8–3.6° (females) for FMA and 86.7 > ± 2.3–4.6° (males) and 88 > ± 2.4–4.8° (females) for TMA. This means HKA 6.4 varus or 4.8° valgus (males) or 5.1° varus to 6.1° valgus was considered normal. For FMA HKA 1.1 varus or 7.3° valgus (males) or 0.2° valgus to 7.4° valgus was considered normal. For TMA HKA 7.9 varus or 1.3° valgus (males) or 6.8° varus to 2.8° valgus was considered normal. Aberrant coronal alignment started from 179.2° ± 8.4° (males) and 180.5 > ± 8.4° (females) for HKA, 93.1 > ± 6.3° (males) 93.8 > ± 5.4° (females) for FMA and 86.7 > ± 6.9° (males) and 88 > ± 7.2° (females) for TMA. This means HKA > 9.2° varus or 7.6° valgus (males) or 7.9° varus to 8.9° valgus was considered aberrant.ConclusionDefinitions of neutrality, normality, deviance as well as aberrance for coronal alignment in TKA were proposed in this study according to their distribution frequencies. This can be seen as an important first step towards a safe transition from the conventional one‐size‐fits‐all to a more personalised coronal alignment target. There should be further definitions combining bony alignment, joint surfaces' morphology, soft tissue laxities and joint kinematics.Level of EvidenceIII.

show abstract

Section: Introductionmentioning

confidence: 99%

Definition of normal, neutral, deviant and aberrant coronal knee alignment for total knee arthroplasty

Hirschmann,

Khan,

Sava

et al. 2024

Knee surg. sports traumatol. arthrosc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…the mismatch between existing femoral prostheses and measured data spotlight the necessity for design modifications. In day-to-day clinical practice, these insights can direct physicians toward selecting prostheses that align more harmoniously with individual anatomical needs, enhancing post-operative outcomes and patient contentment [20]. To summarize, present research not only augments the existing scientific discourse but also affords practical references that can be seamlessly integrated into daily clinical workflows, promoting better patient care.…”

Section: Discussionmentioning

confidence: 87%

“…In China, most available femoral components are based on Caucasian knees, found to be unsuitable for Asian patients [8,24]. Accurate classification of the anterior-posterior length (AP) and medial-lateral (ML) width of the distal femur, as well as production of differently sized prostheses, could provide a solution to this issue [4,20].…”

Section: Introductionmentioning

confidence: 99%

Five or more gender‐ and size‐diverse customizations of distal femur prostheses are needed to improve fit for Chinese knees

Chen,

Zheng,

Guo

et al. 2023

Knee surg. sports traumatol. arthrosc.

View full text Add to dashboard Cite

Purpose Mismatch between partial imported prostheses and Chinese anatomy affects the clinical outcome of the procedure. The purpose of this study was to measure the anatomical dimensions of Chinese distal femurs to provide guidance for the design of more compatible distal femoral prostheses. Methods A total of 406 healthy distal femurs were reconstructed and measured. Consistency of these measurements and differences in sides, gender, and populations were examined. Parameter correlations were analyzed, and pairs with strong correlations underwent linear regression analysis. The design of distal femoral prostheses was referenced from the results of K-means and hierarchical clustering analysis. Results Ten parameters were measured, including the trans-epicondylar axis, width of the distal femur (ML), anteroposterior diameter of the distal femur (AP), etc. The intra-class correlation coefficient ranged from 0.795 to 0.999 for intra-observer consistency, and from 0.796 to 0.998 for inter-observer consistency. Males exhibited significantly larger parameters than females, except for the posterior condylar angle (all P values < 0.05). Compared to other populations, substantial differences were observed for most parameters, such as ML, AP, width of lateral femoral condyle, etc. (all P values < 0.05). Clustering analysis suggested that distal femoral prostheses should include at least five sizes to adequately accommodate the sampled population.

show abstract

“…Patient-specific implants represent a significant advancement in personalized medicine within TKR, aiming to enhance the accuracy of implant placement and alignment. These systems utilize preoperative imaging to create customized surgical guides and implants tailored to each patient's anatomy to restore the native knee anatomy and physiological soft-tissue laxity [48,49]. By replicating the unique knee geometry of individuals, which can vary by factors such as gender, ethnicity, and body type, personalized implants offer potential advantages.…”

Section: Personalized Medicine In Tkrmentioning

confidence: 99%

“…However, their widespread implementation may need to be improved by factors like cost and production time [50]. Nonetheless, personalized medicine is gaining traction in orthopedics, including TKR, where, despite various initiatives, many patients still need to be satisfied [49]. Thus, while offering promising benefits, personalized medicine in TKR should carefully consider the patient's specific condition and expectations and the available surgical techniques and technologies.…”

Section: Personalized Medicine In Tkrmentioning

confidence: 99%

Navigating the Divide: A Comprehensive Review of the Mechanical and Anatomical Axis Approaches in Total Knee Replacement

Suneja,

Deshpande,

Pisulkar

et al. 2024

Cureus

View full text Add to dashboard Cite

This comprehensive review explores the mechanical and anatomical axis approaches in total knee replacement (TKR) surgery, addressing the ongoing debate within the orthopedic community. Emphasizing the significance of TKR in alleviating knee-related disorders, this review underscores the pivotal role of accurate alignment in achieving optimal surgical outcomes. The purpose is to navigate the divide between the well-established mechanical axis approach, focusing on a straight-line alignment, and the anatomical axis approach, aligning with natural knee landmarks. The analysis delves into the advantages, disadvantages, and clinical implications of each approach, offering a nuanced perspective on their efficacy. The conclusion emphasizes a patient-centric approach, recommending the adoption of hybrid strategies and the incorporation of emerging technologies for enhanced precision. The future of TKR aligns with personalized medicine, leveraging advancements in computer-assisted navigation, robotics, and patientspecific implants. Ongoing professional development and interdisciplinary collaboration are crucial for surgeons, and as the field evolves, innovations in artificial intelligence, imaging, and 3D printing are expected to shape the trajectory of TKR alignment approaches.

show abstract

Personalisation and customisation in total knee arthroplasty: the paradox of custom knee implants

Cited by 12 publications

References 30 publications

Definition of normal, neutral, deviant and aberrant coronal knee alignment for total knee arthroplasty

Definition of normal, neutral, deviant and aberrant coronal knee alignment for total knee arthroplasty

Five or more gender‐ and size‐diverse customizations of distal femur prostheses are needed to improve fit for Chinese knees

Navigating the Divide: A Comprehensive Review of the Mechanical and Anatomical Axis Approaches in Total Knee Replacement

Contact Info

Product

Resources

About