Aims. The aim of this study was to determine the risk of tibial eminence avulsion intraoperatively for
Aims.
Abstract. Objectives. There is renewed interest in
Aims. There has been a recent resurgence in interest in combined partial knee arthroplasty (PKA) as an alternative to total knee arthroplasty (TKA). The varied terminology used to describe these procedures leads to confusion and ambiguity in communication between surgeons, allied health professionals, and patients. A standardized classification system is required for patient safety, accurate clinical record-keeping, clear communication, correct coding for appropriate remuneration, and joint registry data collection. Materials and Methods. An advanced PubMed search was conducted, using medical subject headings (MeSH) to identify terms and abbreviations used to describe knee arthroplasty procedures. The search related to TKA, unicompartmental (UKA), patellofemoral (PFA), and combined PKA procedures. Surveys were conducted of orthopaedic surgeons, trainees, and biomechanical engineers, who were asked which of the descriptive terms and abbreviations identified from the literature search they found most intuitive and appropriate to describe each procedure. The results were used to determine a popular consensus. Results. Survey participants preferred “bi-unicondylar arthroplasty” (Bi-UKA) to describe ipsilateral medial and lateral unicompartmental arthroplasty; “medial bi-compartmental arthroplasty” (BCA-M) to describe ipsilateral medial unicompartmental arthroplasty with patellofemoral arthroplasty; “lateral bi-compartmental arthroplasty” (BCA-L) to describe ipsilateral lateral unicompartmental arthroplasty with patellofemoral arthroplasty; and tri-compartmental arthroplasty (TCA) to describe ipsilateral patellofemoral and medial and lateral unicompartmental arthroplasties. “Combined partial knee arthroplasty” (CPKA) was the favoured umbrella term. Conclusion. We recommend
Combined Partial Knee Arthroplasty (CPKA) is a promising alternative to Total Knee Arthroplasty (TKA) for the treatment of multi-compartment arthrosis. Through the simultaneous or staged implantation of multiple Partial Knee Arthroplasties (PKAs), CPKA aims to restore near-normal function of the knee, through retention of the anterior cruciate ligament and native disease-free compartment. Whilst PKA is well established, CPKA is comparatively novel and associated biomechanics are less well understood. Clinically, PKA and CPKA have been shown to better restore knee function compared to TKA, particularly during fast walking. The biomechanical explanation for this superiority remains unclear but may be due to better preservation of the extensor mechanism. This study sought to assess and compare extensor function after PKA, CPKA, and TKA. An instrumented knee extension rig facilitated the measurement extension moment of twenty-four cadaveric knees, which were measured in the native state and then following a sequence of arthroplasty procedures. Eight knees underwent medial Unicompartmental Knee Arthroplasty (UKA-M), followed by patellofemoral arthroplasty (PFA) thereby converting to medial Bicompartmental Knee Arthroplasty (BCA-M). In the final round of testing the PKA implants were removed a posterior-cruciate retaining TKA was implanted. The second eight received lateral equivalents (UKA-L then BCA-L) then TKA. The final eight underwent simultaneous
Numerous fluoroscopic studies of total knee arthroplasty (TKA) kinematics have shown that many contemporary TKA designs exhibit abnormal tibiofemoral translations during activities like gait and stair climbing. One reason for these abnormal motions is the absence of the anterior cruciate ligament (ACL) in the vast majority of knees with TKA. The purpose of this study was to analyze knee kinematics during gait and stair activities in patients with a new design of TKA, incorporating a lateral compartment which is fully congruent in extension, but lax in flexion approximating the function of the anterior cruciate ligament. Our goal was to determine if such ACL-substitution results in more normal weight-bearing kinematics during gait and stair activities. Thirteen ACL-substituting TKAs (AS knees) in 8 patients were observed using fluoroscopy during treadmill gait (1 m/s) and stair stepping. Model-image registration was used to determine the 3D knee kinematics. These kinematics were compared with those from 5 knees with posterior cruciate preserving TKA (PCL Group) and 7 knees with ACL-intact
The metabolic equivalent of task (MET) score examines patient performance in relation to energy expenditure before and after knee arthroplasty. This study assesses its use in a knee arthroplasty population in comparison with the widely used Oxford Knee Score (OKS) and EuroQol five-dimension index (EQ-5D), which are reported to be limited by ceiling effects. A total of 116 patients with OKS, EQ-5D, and MET scores before, and at least six months following, unilateral primary knee arthroplasty were identified from a database. Procedures were performed by a single surgeon between 2014 and 2019 consecutively. Scores were analyzed for normality, skewness, kurtosis, and the presence of ceiling/floor effects. Concurrent validity between the MET score, OKS, and EQ-5D was assessed using Spearman’s rank.Aims
Methods
INTRODUCTION. There is strong current interest to provide reliable treatments for one- and two-compartment arthritis in the cruciate-ligament intact knee. An alternative to total knee arthroplasty is to resurface only the diseased compartments with discrete compartmental components. Placing multiple small implants into the knee presents a greater surgical challenge than total knee arthroplasty, and it is not certain natural knee mechanics can be maintained. The goal of this study was to compare functional kinematics in cruciate-intact knees with either medial unicondylar (mUKA), mUKA plus patellofemoral (mUKA+PF), or
Introduction. Traditional Total Knee Arthpolasty (TKA) replaces all 3 compartments of the knee for patients diagnosed with OA. There might be functional benefit to replacing only damaged compartments, and retaining the normal ligamentous structures. There is a long history of performing multi-compartment arthroplasty with discrete components. Laskin reported in 1976 that good pain relief and acceptable clinical results were achieved at two years in patients with
Total knee arthroplasty (TKA) has evolved over the past 40 years to a point where it now is a routine treatment with fairly predictable outcomes. However, TKA is an end-stage treatment which frequently is used when only one or two compartments in the knee are damaged. Ideally, treatments for earlier stage and isolated disease would be available to provide the same high level of outcome predictability, but provide for isolated treatment of the affected compartments, greater levels of postoperative physical activity and the shorter convalescence demanded by younger, more active, and often employed patients. One approach to a compartment-by-compartment treatment regime is the utilization of discrete condylar unicompartmental prostheses and a patellofemoral prosthesis in any combination. This approach has been practiced in some European clinics for decades with good reported outcomes. However, it remains a major surgical challenge to optimally place multiple discrete arthroplasty components using conventional tools and small incisions. This lecture will present a detailed overview of a unified approach to minimally invasive, modular knee arthroplasty using haptic robotic instrumentation and implants designed specifically for robotic installation in a customized modular treatment regime. Haptic robotics provide a ‘virtual cutting guide’ capability permitting precise sculpturing of bone surfaces using near-zero-visibility minimally invasive incisions. The use of a single-multifunctional tool eliminates many of the instrument trays commonly needed for these procedures. The surgeon has complete control in manipulating the bone cutting tool within the desired bone-removal area, but the haptic robotics prohibit the cutting tool from removing bone outside the planned bone removal volume. Precise bone sculpturing has the potential to minimize bone removal and optimize the alignment and fixation of the prosthetic components. Haptic robotic cutting tools obviously can be used with off-the-shelf prosthetic components, but this approach would fail to fully take advantage of the precision surfaces that can be achieved using robot assisted bone sculpting. Instead, a purpose built system of modular knee components can be defined that work in any combination (medial or lateral unicompartmental,
Joint registries classify all further arthroplasty procedures to a knee with an existing partial arthroplasty as revision surgery, regardless of the actual procedure performed. Relatively minor procedures, including bearing exchanges, are classified in the same way as major operations requiring augments and stems. A new classification system is proposed to acknowledge and describe the detail of these procedures, which has implications for risk, recovery, and health economics. Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system.Aims
Methods
Robotic-assisted unicompartmental knee arthroplasty (UKA) promises accurate implant placement with the potential of improved survival and functional outcomes. The aim of this study was to present the current evidence for robotic-assisted UKA and describe the outcome in terms of implant positioning, range of movement (ROM), function and survival, and the types of robot and implants that are currently used. A search of PubMed and Medline was performed in October 2018 in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included “robotic”, “knee”, and “surgery”. The criteria for inclusion was any study describing the use of robotic UKA and reporting implant positioning, ROM, function, and survival for clinical, cadaveric, or dry bone studies.Aims
Materials and Methods