Aims. The Coronal Plane Alignment of the Knee (CPAK) classification is a simple and comprehensive system for predicting pre-arthritic knee alignment. However, when the
Aims. The Coronal Plane Alignment of the Knee (CPAK) classification has been developed to predict individual variations in inherent knee alignment. The impact of preoperative and postoperative
Restoration of native Coronal Plane Alignment of the Knee (CPAK) phenotype is a strategy suggested to achieve better satisfaction. The aim of this study was to investigate the influence of changes in
Abstract. Introduction. Coronal plane alignment of the knee (CPAK) classification utilises the native arithmetic hip-knee alignment to calculate the constitutional limb alignment and joint line obliquity which is important in pre-operative planning. The objective of this study was to compare the accuracy and reproducibility of measuring the lower limb constitutional alignment with the traditional long leg radiographs versus computed tomography (CT) used for pre-operative planning in robotic-arm assisted TKA. Methods. Digital long leg radiographs and pre-operative CT scan plans of 42 patients (46 knees) with osteoarthritis undergoing robotic-arm assisted total knee replacement were analysed. The constitutional alignment was established by measuring the medial proximal tibial angle (mPTA), lateral distal femoral angle (LDFA), weight bearing hip knee alignment (WBHKA), arithmetic hip knee alignment (aHKA) and joint line obliquity (JLO). Furthermore, the Coronal Plane Alignment of the Knee (CPAK) classification was utilised to classify the patients based on their coronal knee alignment phenotype. Results. Mean age of the patients was 66 years (SD 9) and mean BMI 31.2 (SD 3.9). There were 27 left and 19 right sided surgeries. The Pearson's corelation coefficient was 0.722 (p=0.008) for WBHKA; 0.729 (p<0.001) for MPTA; 0.618 (p=0.14) for aHKA; 0.502 (p= 0.04) for LDFA and 0.305 (p=0.234) for JLO.
Aims. A comprehensive classification for coronal lower limb alignment with predictive capabilities for knee balance would be beneficial in total knee arthroplasty (TKA). This paper describes the Coronal Plane Alignment of the Knee (CPAK) classification and examines its utility in preoperative soft tissue balance prediction, comparing kinematic alignment (KA) to mechanical alignment (MA). Methods. A radiological analysis of 500 healthy and 500 osteoarthritic (OA) knees was used to assess the applicability of the
The Coronal Plane Alignment of the Knee (CPAK) is a recent method for classifying knees using the hip-knee-ankle angle and joint line obliquity to assist surgeons in selection of an optimal alignment philosophy in total knee arthroplasty (TKA)1. It is unclear, however, how
While mechanical alignment (MA) is the traditional technique in total knee arthroplasty (TKA), its potential for altering constitutional alignment remains poorly understood. This study aimed to quantify unintentional changes to constitutional coronal alignment and joint line obliquity (JLO) resulting from MA. A retrospective cohort study was undertaken of 700 primary MA TKAs (643 patients) performed between 2014 and 2017. Lateral distal femoral and medial proximal tibial angles were measured pre- and postoperatively to calculate the arithmetic hip-knee-ankle angle (aHKA), JLO, and Coronal Plane Alignment of the Knee (CPAK) phenotypes. The primary outcome was the magnitude and direction of aHKA, JLO, and CPAK alterations.Aims
Methods
The aims of this study were: 1) to describe extended restricted kinematic alignment (E-rKA), a novel alignment strategy during robotic-assisted total knee arthroplasty (RA-TKA); 2) to compare residual medial compartment tightness following virtual surgical planning during RA-TKA using mechanical alignment (MA) and E-rKA, in the same set of osteoarthritic varus knees; 3) to assess the requirement of soft-tissue releases during RA-TKA using E-rKA; and 4) to compare the accuracy of surgical plan execution between knees managed with adjustments in component positioning alone, and those which require additional soft-tissue releases. Patients who underwent RA-TKA between January and December 2022 for primary varus osteoarthritis were included. Safe boundaries for E-rKA were defined. Residual medial compartment tightness was compared following virtual surgical planning using E-rKA and MA, in the same set of knees. Soft-tissue releases were documented. Errors in postoperative alignment in relation to planned alignment were compared between patients who did (group A) and did not (group B) require soft-tissue releases.Aims
Methods