Efficacy of Patient-Specific Instruments in Total Knee Arthroplasty

Thienpont, Emmanuel; Schwab, Pierre‐Emmanuel; Fennema, Peter

doi:10.2106/jbjs.16.00496

Cited by 106 publications

(94 citation statements)

References 69 publications

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“…The results of our study were in line with these observations, similar results concerning the percentage of mTFA outliers had been reported for PSI before [41]. Interestingly, an improvement in the accuracy of the femoral component in PSI has been reported in a meta analysis [16]. Coincident, the risk for tibial malalignment was found to be increased, which is in accordance with the findings of our study, although we did not measure the femoral positioning [16,42].…”

Section: Discussionsupporting

confidence: 93%

“…Interestingly, an improvement in the accuracy of the femoral component in PSI has been reported in a meta analysis [16]. Coincident, the risk for tibial malalignment was found to be increased, which is in accordance with the findings of our study, although we did not measure the femoral positioning [16,42]. Yamamura et al reported that in PSI, CT-based 3D-measurements demonstrated vast differences between the preoperative planning of the implants and the actual position of the implants after the operation, particularly for the tibial component [43].…”

Section: Discussionmentioning

confidence: 89%

“…In the PSI group, the Visionare Patient Match Technology was used (Visionaire ® , Smith & Nephew, Memphis, TN). Individual cutting blocks made of nylon were produced based on three dimensional models from MRI and standing long-leg radiographs [16].…”

Section: Operative Techniquementioning

confidence: 99%

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Accuracy of tibial positioning in the frontal plane: a prospective study comparing conventional and innovative techniques in total knee arthroplasty

Zahn

Graef

Conrad

et al. 2020

Arch Orthop Trauma Surg

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Background Coronal alignment of the tibial component determines functional outcome and survival in total knee arthroplasty (TKA). Innovative techniques for tibial instrumentation have been developed to improve accuracy and reduce the rate of outliers. Methods In a prospective study, 300 patients were allocated to four different groups using a randomization process (two innovative and two conventional) techniques of tibial instrumentation (conventional: extramedullary, intramedullary; innovative: navigation and patient-specific instrumentation (PSI); n = 75 for each group). The aims were to reconstruct the medial proximal tibial angle (MPTA) to 90° and the mechanical tibio-femoral axis (mTFA) to 0°. Both angles were evaluated and compared between all groups three months after the surgery. Patients who presented with a postoperative mTFA > 3° were classified as outliers. Results The navigation and intramedullary technique both demonstrated that they were significantly more precise in reconstructing a neutral mTFA and MPTA compared to the other two techniques. The odd's ratio (OR) for producing outliers was highest for the PSI method (PSI OR = 5.5, p < 0.05; extramedullary positioning OR = 3.7, p > 0.05; intramedullary positioning OR = 1.7, p > 0.05; navigation OR = 0.04, p < 0.05). We could only observe significant differences between pre-and postoperative MPTA in the navigation and intramedullary group. The MPTA showed a significant negative correlation with the mTFA in all groups preoperatively and in the extramedullary, intramedullary and PSI postoperatively. Conclusion The navigation and intramedullary instrumentation provided the precise positioning of the tibial component. Outliers were most common within the PSI and extramedullary technique. Optimal alignment is dependent on the technique of tibial instrumentation and tibial component positioning determines the accuracy in TKA since mTFA correlated with MPTA pre-and postoperatively.

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Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 89%

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Accuracy of tibial positioning in the frontal plane: a prospective study comparing conventional and innovative techniques in total knee arthroplasty

Zahn

Graef

Conrad

et al. 2020

Arch Orthop Trauma Surg

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“…Two recent meta‐analyses enrolled only 9 studies that reported femoral rotation as an outcome, and reached conflicting results: Thienpont et al . concluded that no differences with regard to the rotational alignment are to be expected in the axial plane with the use of PSI, whereas Huijbregts et al . calculated the femoral rotation to be 0.45° more accurate with PSI.…”

Section: Discussionmentioning

confidence: 98%

“…Patient-specific instrumentation has not yet been clearly demonstrated as effective in increasing the accuracy or precision of femoral component rotation: several studies have investigated the effect of PSI on rotational alignment and, with a few exceptions 8,27 , did not find statistical difference with respect to the outliers of femoral component rotation 14,15 and the accuracy in postoperative alignment of femoral rotation [12][13][14]20 . Two recent meta-analyses enrolled only 9 studies that reported femoral rotation as an outcome, and reached conflicting results: Thienpont et al concluded that no differences with regard to the rotational alignment are to be expected in the axial plane with the use of PSI, 28 whereas Huijbregts et al calculated the femoral rotation to be 0.45 more accurate with PSI 9 . Reduction in the number of outliers from target rotational femoral component alignment indicates increased precision: controversial results have been obtained regarding this outcome, with some study groups reporting significant differences in favor of PSI 5,10 and others not 6,7,29 .…”

Section: Discussionmentioning

confidence: 99%

Patient‐specific Instrumentation Affects Rotational Alignment of the Femoral Component in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

Cucchi

Menon

Aliprandi³

et al. 2019

Orthopaedic Surgery

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Objective To evaluate whether patient‐specific instrumentation (PSI) improve the accuracy of femoral component rotational alignment with respect to conventionally‐implanted total knee arthroplasty (TKA). Methods Twenty‐four patients were randomized to receive a TKA implanted with PSI or conventional instrumentation. Implant orientation was compared on Computed Tomography (CT). Surgical time, recuts, and component size variations from planning were recorded. Preoperative and postoperative Oxford knee score and visual analogue scale were compared to assess clinical outcomes. Results Femoral components implanted with patient‐specific instrumentation were aligned with greater external rotation than those implanted with conventional instrumentation ( P = 0.022). No significant differences were found in surgical times, number of recuts, and clinical outcomes. Surgeon modifications from the planned size were necessary in 58% of PSI cases. Conclusion Femoral components implanted with PSI had greater external rotation than with conventional instrumentation. Surgeons must carefully evaluate component sizes when using PSI, both in planning and during surgery.

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The coronal alignment differs between two‐dimensional weight‐bearing and three‐dimensional nonweight bearing planning in total knee arthroplasty

Pflüger,

Hodel,

Zimmermann

et al. 2024

J. exp. orthop.

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PurposeThe goal of this study is (1) to assess differences between two‐dimensional (2D) weight‐bearing (WB) and three‐dimensional (3D) nonweight‐bearing (NWB) planning in total knee arthroplasty (TKA) and (2) to identify factors that influence intermodal differences.MethodsRetrospective single‐centre analysis of patients planned for a TKA with patient‐specific instruments (PSI). Preoperative WB long‐leg radiographs and NWB computed tomography were analysed and following radiographic parameters included: hip–knee–ankle angle (HKA) (+varus/−valgus), joint line convergence angle (JLCA), femorotibial subluxation and bony defect classified according to Anderson. Preoperative range of motion was also considered as possible covariate. Demographic factors included age, sex, and body mass index.ResultsA total of 352 knees of 323 patients (66% females) with a mean age of 66 ± 9.7 years were analysed. The HKA differed significantly between 2D and 3D planning modalities; varus knees (n = 231): 9.9° ± 5.1° vs. 6.7° ± 4°, p < 0.001; valgus knees (n = 121): −8.2° ± 6° vs. −5.5° ± 4.4°, p < 0.001. In varus knees, HKA (β = 0.38; p < 0.0001) and JLCA (β = 0.14; p = 0.03) were associated with increasing difference between 2D/3D HKA. For valgus knees, HKA (β = −0.6; p < 0.0001), JLCA (β = −0.3; p = 0.0001) and lateral distal femoral angle (β = −0.28; p = 0.03) showed a significant influence on the mean absolute difference.ConclusionThe coronal alignment in preoperative 3D model for PSI‐TKA significantly differed from 2D WB state and the difference between modalities correlated with the extent of varus/valgus deformity. In the vast majority of cases, the 3D NWB approach significantly underestimated the preoperative deformity, which needs to be considered to achieve the planned correction when using PSI in TKA.Level of EvidenceLevel III.

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Efficacy of Patient-Specific Instruments in Total Knee Arthroplasty

Abstract: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Cited by 106 publications

References 69 publications

Accuracy of tibial positioning in the frontal plane: a prospective study comparing conventional and innovative techniques in total knee arthroplasty

Accuracy of tibial positioning in the frontal plane: a prospective study comparing conventional and innovative techniques in total knee arthroplasty

Patient‐specific Instrumentation Affects Rotational Alignment of the Femoral Component in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

The coronal alignment differs between two‐dimensional weight‐bearing and three‐dimensional nonweight bearing planning in total knee arthroplasty

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