Patient-specific total knee arthroplasty: the importance of planning by the surgeon

Pietsch, M.; Djahani, O.; Hochegger, M.; Plattner, F.; Hofmann, S.

doi:10.1007/s00167-013-2624-7

Cited by 66 publications

(80 citation statements)

References 22 publications

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“…The accuracy of the preoperative plan accompanying the PSI was also called into question by our literature review. This represents a significant aspect in procedural efficiency, because four studies demonstrated inaccuracies in anticipated alignment or a need to change the preoperative plan with respect to the planned resections or component sizes [10,27,29,31]. This apparent need for secondary checks would seem to diminish the value of PSI considerably as it relates to operative efficiency.…”

Section: Discussionmentioning

confidence: 99%

“…One Level II study concluded that the bony cuts achieved using the patient-specific cutting blocks did not always match the preoperative plan generated [29]. An additional Level II study [31] and a Level III study [27] noted a high frequency of intraoperative changes to the preoperative plan and component sizing required to achieve an optimal surgical result. Finally, another Level II study demonstrated that cuts achieved with PSI did not correspond to the preoperative plan when checked intraoperatively with computer-assisted navigation tools [10].…”

Section: Domentioning

confidence: 99%

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Systematic Review of Patient-specific Instrumentation in Total Knee Arthroplasty: New but Not Improved

Sassoon

Nam

Nunley

et al. 2015

Clinical Orthopaedics &Amp; Related Research

183

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Background Patient-specific cutting blocks have been touted as a more efficient and reliable means of achieving neutral mechanical alignment during TKA with the proposed downstream effect of improved clinical outcomes. However, it is not clear to what degree published studies support these assumptions. Questions/purposes We asked: (1) Do patient-specific cutting blocks achieve neutral mechanical alignment more reliably during TKA when compared with conventional methods? (2) Does patient-specific instrumentation (PSI) provide financial benefit through improved surgical efficiency? (3) Does the use of patient-specific cutting blocks translate to improved clinical results after TKA when compared with conventional instrumentation? Methods We performed a systematic review in accordance with Cochrane guidelines of controlled studies (prospective and retrospective) in MEDLINE 1 and EM-BASE 1 with respect to patient-specific cutting blocks and their effect on alignment, cost, operative time, clinical outcome scores, complications, and survivorship. Sixteen studies (Level I-III on the levels of evidence rubric) were identified and used in addressing the first question, 13 (Level I-III) for the second question, and two (Level III) for the third question. Qualitative assessment of the selected Level I studies was performed using the modified Jadad score; Level II and III studies were rated based on the Newcastle-Ottawa scoring system. Results The majority of studies did not show an improvement in overall limb alignment when PSI was compared with standard instrumentation. Mixed results were seen across studies with regard to the prevalence of alignment outliers when PSI was compared with conventional cutting blocks with some studies demonstrating no difference, some showing an improvement with PSI, and a single study showing worse results with PSI. The studies demonstrated mixed results regarding the influence of PSI on operative times. Decreased operative times were not uniformly observed, and when noted, they were found to be of minimal clinical or financial significance. PSI did reliably reduce the number of instrument trays required for processing perioperatively. The accuracy of the preoperative plan, generated by the PSI manufacturers, was found lacking, often leading to multiple intraoperative changes, thereby disrupting the flow of the operation and negatively impacting efficiency. Limited data exist with regard to the effect of PSI on postoperative function, improvement in pain, and patient

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Section: Discussionmentioning

confidence: 99%

Section: Domentioning

confidence: 99%

Systematic Review of Patient-specific Instrumentation in Total Knee Arthroplasty: New but Not Improved

Sassoon

Nam

Nunley

et al. 2015

Clinical Orthopaedics &Amp; Related Research

183

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“…patients [29,37,40,41]. Recently, Woolson et al [40] reported the results of a randomized clinical trial of 22 TKAs performed using a CT-based CCG system ( TKAs performed using standard instrumentation to assess early patient-reported and gait analysis outcomes.…”

Section: Discussionmentioning

confidence: 99%

The Mark Coventry Award: Custom Cutting Guides Do Not Improve Total Knee Arthroplasty Clinical Outcomes at 2 Years Followup

Nam

Park

Stambough

et al. 2016

Clinical Orthopaedics &Amp; Related Research

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Background Custom cutting guides (CCGs; sometimes called patient-specific instrumentation [PSI]) in total knee arthroplasty (TKA) use preoperative three-dimensional imaging to fabricate cutting blocks specific to a patient's native anatomy. Questions/purposes The purposes of this study were to determine if CCGs (1) improve clinical outcomes as measured by UCLA activity, SF-12, and Oxford knee scores; and (2) coronal mechanical alignment versus standard alignment guides. Methods This was a retrospective cohort study of patients undergoing primary TKA using the same cruciate-retaining, cemented TKA system between January 2009 and April 2012. Patients were included if they were candidates for a unilateral, cruciate-retaining TKA and met other prespecified criteria; patients were allowed to self-select either an MRI-based CCG procedure or standard TKA. Ninety-seven of 120 (80.8%) patients in the standard and 104 of 124 (83.9%, p = 0.5) in the CCG cohort with a minimum of 1-year followup were available for analysis. The first 95 patients in the standard (mean followup, 3 years; range, 1-4 years) and CCG (mean followup, 2 years; range, 1-4 years) cohorts were compared. The alignment goal for all TKAs was a hip-knee-ankle (HKA) angle of 0°. UCLA, SF-12, and Oxford knee scores were collected preoperatively and at each patient's most recent followup visit. Postoperative, rotationally controlled coronal scout CT scans were used to measure HKA alignment. Independent-sample t-tests and chi-square tests were used

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“…For instance, how accurately can the engineer plan a case without relevant clinical information on underlying fixed flexion deformity? The paper of Pietsch et al published in the current issue showed that the surgeon has to revise the planing by the engineer quite regularly [12].There can be a significant mismatch between planning by the engineer and the final component placement. How accurately can the surgeon position guides on flat surfaces like a dysplastic trochlea in the valgus knee?…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Alignment in total knee arthroplasty, still more questions than answers…

Thienpont

Bellemans

Victor

et al. 2013

Knee Surg Sports Traumatol Arthrosc

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The focus of the current issue is on technologies such as computer-assisted surgery (CAS) and patient-specific instrumentation (PSI) in total knee arthroplasty (TKA). CAS helps the surgeon navigate each individual patient's case based on bony landmarks in order to identify the correct positioning of the femoral and tibial cutting guides. The presumption was that component sizing and placement should be more accurate using CAS than the more conventional technique, resulting in both better alignment and clinical outcome. Many surgeons were convinced in the past that this technique would become the standard for TKA. Clinical studies have demonstrated that CAS reduces the number of outliers in component positioning and leg alignment as reported in the study by Lützen et al. [9]. Similar results have also been reported in a meta-analysis of level-I studies [6]. Unfortunately, the total time spent in the operating room and the lack of clinical amelioration has tempered its uniform acceptance by the surgical community [3,14].Patient-specific instruments (PSI), recently introduced as a new technology, could demonstrate the same advantage of navigation in increasing accuracy, but without the practical inconveniences such as, the need to perform anatomical mapping or to position trackers during the procedure [10].The virtual planning of the TKA procedure is outsourced to engineers who identify the anatomical landmarks needed for alignment on CT/MRI based 3D models, after which the information is transferred to patient-specific instruments that can be used during surgery. These instruments, created by laser sintering, can be produced in the most complex forms and are thus patient specific [1,5].The idea of finding anatomical landmarks on CT or MRI and relaying this virtual planning to the real-time environment of the operating room is innovative. Issues surrounding this innovation are of great importance and many questions remain unanswered. Despite the new technologies, we continue to rely on the same anatomical landmarks as used in the conventional technique. For instance, how accurately can the engineer plan a case without relevant clinical information on underlying fixed flexion deformity? The paper of Pietsch et al. published in the current issue showed that the surgeon has to revise the planing by the engineer quite regularly [12].There can be a significant mismatch between planning by the engineer and the final component placement. How accurately can the surgeon position guides on flat surfaces like a dysplastic trochlea in the valgus knee?How accurate are the pinning capacities of a surgeon and how much accuracy is lost when positioning the conventional instruments over the pins?We are also cognisant of the cutting errors caused by the oscillating saw blade, which influences the accuracy of the surgery [18]. Accuracy in TKA is a multifactorial issue and extremely complex.

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Patient-specific total knee arthroplasty: the importance of planning by the surgeon

Abstract: Therapeutic study, Level III.

Cited by 66 publications

References 22 publications

Systematic Review of Patient-specific Instrumentation in Total Knee Arthroplasty: New but Not Improved

Systematic Review of Patient-specific Instrumentation in Total Knee Arthroplasty: New but Not Improved

The Mark Coventry Award: Custom Cutting Guides Do Not Improve Total Knee Arthroplasty Clinical Outcomes at 2 Years Followup

Alignment in total knee arthroplasty, still more questions than answers…

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