Browsing by Subject "Total knee arthroplasty"
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- PublicationRestrictedComparison of weight-bearing full-length radiographs and computed-tomography-scan-based three-dimensional models in the assessment of knee joint coronal alignment(Elsevier, 2020-03) López López, Mirian; Santonja Medina, Fernando; León Muñoz, Vicente Jesús; Martínez Martínez, Francisco; Cirugía, Pediatría y Obstetricia y GinecologíaBackground: The aim of the study was to determine any discrepancies among preoperative full-leg standing radiographs (LLR) and supine non-weight-bearing computed tomography (CT)-scan-based three-dimensional (3D) models in the assessment of the lower limb alignment prior to total knee arthroplasty (TKA) and answer the question of whether the LLR study can be obviated in preoperative planning when TKA is performed with patient-specific instrumentation (PSI). Methods: LLR and CT-scan-based 3D models of 227 knees (183 patients) were measured. LLR data was then compared to 3D alignment data used to design the PSI for TKA surgery. Results: Alignment on LLR ranged from 153 to 194° versus 161.5 to 190.5° with CT-scan-based 3D models. The mean (standard deviation, SD) difference among techniques was 1.9° (1.15°) with a statistically significant difference (P = 2e-16, namely P b .0001). Supine CT-scanbased 3D models underestimated the deformity in 167 cases (73.6%), exactly matched the value of LLR in 24 cases (10.6%) and overestimated the deformity in 36 cases (15.8%). Conclusion: CT-scan-based models underestimate the degree of deformity at the knee joint. Despite the accurate information provided by the CT-scan and the 3D models (which is the basis for the planning of bone cuts), weight-bearing LLR should not be overlooked in the planning of TKA surgery to assess the extent of the coronal mediolateral instability.
- PublicationRestrictedComputed tomography-based patient-specific instrumentation loses accuracy with significant varus preoperative misalignment(Thieme Gruppe, 2020-09-08) López López, Mirian; Lisón Almagro, Alonso José; Santonja Medina, Fernando; León Muñoz, Vicente Jesús; Martínez Martínez, Francisco; Cirugía, Pediatría y Obstetricia y GinecologíaPatient-specific instrumentation (PSI) has been introduced to simplify and make total knee arthroplasty (TKA) surgery more precise, effective, and efficient. We performed this study to determine whether the postoperative coronal alignment is related to preoperative deformity when computed tomography (CT)-based PSI is used for TKA surgery, and how the PSI approach compares with deformity correction obtained with conventional instrumentation. We analyzed pre-and post-operative full length standing hip-knee-ankle (HKA) X-rays of the lower limb in both groups using a convention > 180 degrees for valgus alignment and < 180 degrees for varus alignment. For the PSI group, the mean ( SD) pre-operative HKA angle was 172.09 degrees varus ( 6.69 degrees) with a maximum varus alignment of 21.5 degrees (HKA 158.5) and a maximum valgus alignment of 14.0 degrees. The mean post-operative HKA was 179.43 degrees varus ( 2.32 degrees) with a maximum varus alignment of seven degrees and a maximum valgus alignment of six degrees. There has been a weak correlation among the values of the pre- and postoperative HKA angle. The adjusted odds ratio (aOR) of postoperative alignment outside the range of 180 3 degrees was significantly higher with a preoperative varus misalignment of 15 degrees or more (aOR: 4.18; 95% confidence interval: 1.35–12.96; p ¼ 0.013). In the control group (conventional instrumentation), this loss of accuracy occurs with preoperative misalignment of 10 degrees. Preoperative misalignment below 15 degrees appears to present minimal influence on postoperative alignment when a CT-based PSI system is used. The CT-based PSI tends to lose accuracy with preoperative varus misalignment over 15 degrees.
- PublicationRestrictedImpact of surgical instrumentation on hospital length of stay and cost of total knee arthroplasty(Taylor and Francis, 2020-06-21) López López, Mirian; Santonja Medina, Fernando; León Muñoz, Vicente Jesús; Martínez Martínez, Francisco; Cirugía, Pediatría y Obstetricia y GinecologíaBackground: We aimed to analyze the impact of two different types of surgical instrumentation (conventional manual instrumentation (CI) and patient-specific instrumentation (PSI)) on length of stay (LOS) and objectify differences in cost. We hypothesized that there are no differences in the LOS and cost due to the instrumentation system used. Research design and methods: LOS was registered using inpatient admission data provided by the Institutional Management Control Department. We recorded the costs associated with each procedure that could be influenced by the use of one system or another during the in-hospital stay. We conducted a prospectively single-center cohort study of 305 TKAs. Surgery was performed with conventional CI in 122 cases and with PSI in 183 cases. Results: The mean LOS for the CI group was 4.29 days (SD 1.65) and 4.22 days (SD 1.26), for the PSI group. No significant difference among both instrumentation systems was obtained. When comparing global costs, the mean cost was slightly higher (without a significant difference) for the PSI cases (€3110.24 vs. €2852.7 for the CI cases). Conclusions: LOS and overall cost, in hospitals with a low annual TKA surgery volume, are unrelated to conventional or patient-specific instrumentation.
- PublicationOpen AccessPatient-specific instrumentation accuracy evaluated with 3D virtual models(MDPI, 2021-04-01) Parrinello, Andrea; Manca, Silvio; Galloni, Gianluca; López López, Mirian; Santonja Medina, Fernando; León Muñoz, Vicente Jesús; Martínez Martínez, Francisco; Cirugía, Pediatría y Obstetricia y GinecologíaThere have been remarkable advances in knee replacement surgery over the last few decades. One of the concerns continues to be the accuracy in achieving the desired alignment. Patient-specific instrumentation (PSI) was developed to increase component placement accuracy, but the available evidence is not conclusive. Our study aimed to determine a PSI system’s three-dimensional accuracy on 3D virtual models obtained by post-operative computed tomography. We compared the angular placement values of 35 total knee arthroplasties (TKAs) operated within a year obtained with the planned ones, and we analyzed the possible relationships between alignment and patient-reported outcomes. The mean (SD) discrepancies measured by two experienced engineers to the planned values observed were 1.64° (1.3°) for the hip–knee–ankle angle, 1.45° (1.06°) for the supplementary angle of the femoral lateral distal angle, 1.44° (0.97°) for the proximal medial tibial angle, 2.28° (1.78°) for tibial slope, 0.64° (1.09°) for femoral sagittal flexion, and 1.42° (1.06°) for femoral rotation. Neither variables related to post-operative alignment nor the proportion of change between pre-and post-operative alignment influenced the patient-reported outcomes. The evaluated PSI system’s three-dimensional alignment analysis showed a statistically significant difference between the angular values planned and those obtained. However, we did not find a relevant effect size, and this slight discrepancy did not impact the clinical outcome.
- PublicationRestrictedPatient-specific instrumentation makes sense in total knee arthroplasty(Taylor and Francis Group, 2022-08-03) López López, Mirian; Santonja Medina, Fernando; León Muñoz, Vicente Jesús; Cirugía, Pediatría y Obstetricia y GinecologíaIntroduction: Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) surgery was initially developed to increase accuracy. The potential PSI benefits have expanded in the last decade, and other advantages have been published. However, different authors are critical of PSI and argue that the advantages are not such and do not compensate for the extra cost. This article aims to describe the recently published advantages and disadvantages of PSI. Areas covered: Narrative description of the latest publications related to PSI in accuracy, clinical and functional outcomes, operative time, efficiency, and other benefits. Expert opinion: We have published high accuracy of the system, with a not clinically relevant loss of accuracy, significantly higher precision with PSI than with conventional instruments, and a high percentage of cases in the optimal range and similar to that obtained with computer-assisted navigation, greater imprecision for tibial slope, a significant blood loss reduction, and time consumption, an acceptable and non-significant increase in the cost per procedure, and no difference in complications during hospital admission and at 90 days. We think that PSI will not follow the Scott Parabola and that it will continue to be a valuable type of device in some instances of TKA surgery.
- PublicationRestrictedReliability of the posterior condylar offset(Wiley, 2022-08) Parrinello, Andrea; Galloni, Gianluca; Lisón Almagro, Alonso J; López López, Mirian; Santonja Medina, Fernando; León Muñoz, Vicente Jesús; Martínez Martínez, Francisco; Cirugía, Pediatría y Obstetricia y GinecologíaThe posterior condylar offset (PCO) has been proposed as a determinant of a postoperative range of motion after total knee arthroplasty, although there is no consensus. This study aimed to demonstrate the error introduced by forcing the femoral rotation to overlap both condyles for the “true” lateral X‐ray projection for the PCO measurement. We hypothesize that the angular discrepancy between the posterior femoral cortical reference plane and the posterior condylar axis plane due to rotation invalidates the acquisition of reliable measurements on X‐rays. We have measured the PCO in 50 “true” lateral X‐rays and compared it with the medial and lateral condyles PCO's assessed on a computed tomography‐scan‐based three‐ dimensional (3D) model of each knee. PCO based on the 3D imaging differed significantly between the medial (25.8 ± 3.67 mm) and lateral (16.59 ± 2.92 mm) condyle. Three‐dimensional PCO values differ significantly from those determined in the radiographic studies. Also, the mean values of the medial and lateral condyle PCO measurements differed significantly (p < 0.001) with all PCO measurements on radiographs. We have identified a difference between the posterior cortical plane and the posterior condylar axis projections, both on the axial plane with a mean value of 11.23° ± 3.64°. Our data show an interplane discrepancy angle between the posterior femoral diaphyseal cortical and the posterior condylar axis plane (due to the femur's necessary rotation to overlap both condyles) may invalidate the 2D X‐ray PCO assessment as a reliable measurement.
- PublicationOpen AccessRevision of total knee arthroplasty with the use of patient-specific instruments: an alternative surgical technique(Taylor and Francis Group, 2020-08-09) Parrinello, Andrea; López López, Mirian; Santonja Medina, Fernando; León Muñoz, Vicente Jesús; Martínez Martínez, Francisco; Cirugía, Pediatría y Obstetricia y GinecologíaIntroduction: Accuracy in the placement of components in revision total knee arthroplasty (R-TKA) surgery is sometimes challenging. The applicability of patient-specific instruments (PSI) in knee surgery has progressively expanded to types of surgery other than primary arthroplasty. Could this assistive technology be used to facilitate accurate R-TKA surgery? The aim of the current manuscript is to describe this new application of PSI for revision of TKA-to-TKA and to provide a step-by-step technical guideline for use. Areas covered: We will describe the application and a detailed description of PSI technology to TKA revision surgery, step-by-step, from CT images acquisition for preoperative planning and PSI blocks production to the surgery. Expert commentary: The system can facilitate the accomplishment of the bony cuts for optimal implant placement and that can be useful in minimally altering the femoral and the tibial joint line. It is obvious that technology alone will not replace surgical skill and that accuracy of the system will also depend on the quality of the CT images and the ability of the software to prevent metal artifacts. Despite that, our initial results are promising and prove that the concept of applying PSI technology to the R-TKA surgery is feasible.