Preoperative Joint Distraction Imaging and Planning Protocol for Total Knee Arthroplasty

PurposeTo identify, synthesise and critically appraise findings of systematic reviews and meta‐analyses on pre‐ and post‐operative radiographic angles (lateral distal femoral angle [LDFA], medial proximal tibial angle [MPTA] and hip–knee–ankle [HKA] angle) of unrestricted kinematic alignment versus mechanical alignment in total knee arthroplasty (TKA).MethodsTwo authors searched MEDLINE, EMBASE and Epistemonikos for systematic reviews, with or without meta‐analyses, that reported on TKA outcomes using unrestricted kinematic alignment. The methodological quality of the included systematic reviews and meta‐analyses was independently assessed using A MeaSurement Tool to Assess systematic Reviews (AMSTAR‐2). The effect size with its 95% confidence interval (CI) for radiographic angles was extracted from the systematic reviews and meta‐analyses. The characteristics of clinical studies included in systematic reviews were listed and tabulated. Pre‐ and post‐operative MPTA, LDFA and HKA angles were summarised using meta‐analytic random‐effects models.ResultsNineteen records were eligible for data extraction. Systematic reviews and meta‐analyses included 44 clinical studies, of which 31 were on unrestricted kinematic alignment and 13 were on restricted versions of kinematic alignment. None of the included systematic reviews or meta‐analyses fulfiled all seven critical AMSTAR‐2 domains. Few comparative studies reported both pre‐ and post‐operative angles (LDFA, n = 3; MPTA, n = 4; and HKA angle, n = 10). Mean pre‐ and post‐operative LDFAs were 88.0° (range, 83–94°) and 88.0° (range, 80–96°) for the kinematic alignment group, and 88.2° (range, 83–95°) and 90.2° (range, 84–97°) for the mechanical alignment group. Mean pre‐ and post‐operative MPTAs were 86.0° (range, 78–93°) and 87.1° (range, 78–94°) for the kinematic alignment group and 86.4° (range, 77–94°) and 89.6° (range, 84–95°) for the mechanical alignment group. Mean pre‐ and post‐operative HKA angles were −3.3° (range, −24° to 24°) and −0.3° (range, −10° to 8°) for the kinematic alignment group and −6.9° (range, −25° to 7°) and −0.9° (range, −8° to 7°) for the mechanical alignment group.ConclusionMost systematic reviews and meta‐analyses that report outcomes of TKA using kinematic alignment do not distinguish between the different versions of kinematic alignment. The clinical studies included in systematic reviews are limited and inconsistent in their reporting of radiographic angles. Different alignment strategies are often grouped under the umbrella term of kinematic alignment, which contributes to conflicting reports, confusion and unresolved questions regarding the efficacy of true unrestricted kinematic alignment.Level of EvidenceLevel IV.

Sparse and inconsistent reporting of pre‐ and post‐operative radiographic angles of total knee arthroplasty using true unrestricted kinematic alignment: An umbrella review and secondary meta‐analysis

Saffarini,

Canetti,

Henry

et al. 2024

Patient‐reported outcome measures following individualised TKA are not affected by the degree of preoperative coronal varus or valgus laxity

Sappey‐Marinier,

Bouguerra,

Chapuis

et al. 2024

PurposeTo determine whether there is a correlation between preoperative coronal varus or valgus laxity and patient‐reported outcome measures (PROMs) 2 years after individualised total knee arthroplasty (TKA).MethodsRecords of 150 consecutive patients who received individualised TKA were retrospectively analysed, and 126 with complete pre‐ and postoperative data were included. Preoperative coronal varus and valgus stress radiographs (15 N load) were taken using a telos stress device with the knee in 5°–10° of flexion. Varus stress angles were positive if the joint opened on the lateral side, and valgus stress angles were positive if the joint opened on the medial side. The sum of varus and valgus stress angles indicated total joint laxity. During surgery, cases that required tibial recuts to balance the joint were recorded. Patients completed three PROMs and rated their satisfaction. Correlations between laxity and PROMs were evaluated using Pearson's correlation.ResultsStress radiographs revealed varus stress angles of 6.3° ± 3.5° (range, −4.5° to 14.1°), valgus stress angles of 0.1° ± 3.7° (range, −8.0° to 10.9°), and the sum of the varus and valgus stress angle of 6.4° ± 3.3° (range, 0.1° to 17.1°). There were no correlations between laxity and PROMs: r < 0.160 for varus stress angle, r < 0.180 for valgus stress angle and r < 0.160 for the sum of stress angles. There were no statistically significant or clinically relevant differences in PROMs between knees without and those with tibial recuts.ConclusionPreoperative coronal varus or valgus laxity was not correlated with PROMs following individualised TKA at a minimum 2‐year follow‐up. Individualised TKA with personalised alignment enables adequate accommodation of a broad spectrum of preoperative coronal varus–valgus laxities.Level of EvidenceIV

Inappropriate grouping of various kinematic alignment techniques and inconsistent reporting of adverse events invalidate comparison across studies: An umbrella review of meta‐analyses

Cognault,

Verdier,

Hirschmann

2024

PurposeThis umbrella review aimed to identify, synthesise and critically appraise the findings of meta‐analyses that compare adverse events—rates of complications, reoperations and revisions—following total knee arthroplasty (TKA) using unrestricted kinematic alignment versus mechanical alignment.MethodsUsing the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses criteria, two authors independently screened articles based on inclusion and exclusion criteria, and assessed the methodological quality based on the 16 domains of A MeaSurement Tool to Assess systematic Reviews (AMSTAR‐2). Effect sizes of difference in rates of complications were tabulated for each meta‐analysis. Studies included in the meta‐analyses were assessed to determine if they were on true unrestricted kinematic alignment. A secondary meta‐analysis was performed, excluding studies on restricted kinematic alignment techniques, to calculate pooled estimates of adverse events (odds ratio [OR] with its 95% confidence interval [CI]) in a common effects framework with inverse‐variance weighting.ResultsOf 78 potential records, 13 meta‐analyses were eligible for data extraction, which pooled data from 15 clinical studies (10 on unrestricted kinematic alignment, four on restricted kinematic alignment and one on inverse kinematic alignment). None of the meta‐analyses fulfilled all seven critical AMSTAR‐2 domains. Meta‐analyses categorised adverse events differently and used different measures for the effect sizes but revealed no differences between kinematic versus mechanical alignment. Exclusion of studies on restricted kinematic alignment techniques reduced total sample sizes for kinematic alignment from 658 to 318 and for mechanical alignment from 811 to 403. Secondary meta‐analyses exclusively on unrestricted kinematic alignment revealed no difference in complications without reoperation, reoperation without implant removal or reoperation with implant removal following kinematic versus mechanical alignment.ConclusionMeta‐analyses do not distinguish between various kinematic alignment techniques, and adverse events are compared using different metrics. Surgeons, researchers and editors should refrain from pooling data on various kinematic alignment techniques, and orthopaedic societies should promote standards for reporting adverse events and effect sizes to facilitate comparisons across future studies.Level of EvidenceLevel III.