Robotic arm-assisted surgery offers accurate and reproducible guidance in component positioning and assessment of soft-tissue tensioning during knee arthroplasty, but the feasibility and early outcomes when using this technology for revision surgery remain unknown. The objective of this study was to compare the outcomes of robotic arm-assisted revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) versus primary robotic arm-assisted TKA at short-term follow-up. This prospective study included 16 patients undergoing robotic arm-assisted revision of UKA to TKA versus 35 matched patients receiving robotic arm-assisted primary TKA. In all study patients, the following data were recorded: operating time, polyethylene liner size, change in haemoglobin concentration (g/dl), length of inpatient stay, postoperative complications, and hip-knee-ankle (HKA) alignment. All procedures were performed using the principles of functional alignment. At most recent follow-up, range of motion (ROM), Forgotten Joint Score (FJS), and Oxford Knee Score (OKS) were collected. Mean follow-up time was 21 months (6 to 36).Aims
Methods
Total knee arthroplasty (TKA) using functional alignment aims to implant the components with minimal compromise of the soft-tissue envelope by restoring the plane and obliquity of the non-arthritic joint. The objective of this study was to determine the effect of TKA with functional alignment on mediolateral soft-tissue balance as assessed using intraoperative sensor-guided technology. This prospective study included 30 consecutive patients undergoing robotic-assisted TKA using the Stryker PS Triathlon implant with functional alignment. Intraoperative soft-tissue balance was assessed using sensor-guided technology after definitive component implantation; soft-tissue balance was defined as intercompartmental pressure difference (ICPD) of < 15 psi. Medial and lateral compartment pressures were recorded at 10°, 45°, and 90° of knee flexion. This study included 18 females (60%) and 12 males (40%) with a mean age of 65.2 years (SD 9.3). Mean preoperative hip-knee-ankle deformity was 6.3° varus (SD 2.7°).Aims
Methods
The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups. This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups.Aims
Methods
The objectives of this study were to assess the effect of anterior cruciate ligament (ACL) resection on flexion-extension gaps, mediolateral soft tissue laxity, maximum knee extension, and limb alignment during primary total knee arthroplasty (TKA). This prospective study included 140 patients with symptomatic knee osteoarthritis undergoing primary robotic-arm assisted TKA. All operative procedures were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess study outcomes pre- and post-ACL resection with knee extension and 90° knee flexion. This study included 76 males (54.3%) and 64 females (45.7%) with a mean age of 64.1 years (SD 6.8) at time of surgery. Mean preoperative hip-knee-ankle deformity was 6.1° varus (SD 4.6° varus).Aims
Methods
The aim of this study was to assess the effect of posterior cruciate ligament (PCL) resection on flexion-extension gaps, mediolateral soft-tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilized (PS) total knee arthroplasty (TKA). This prospective study included 110 patients with symptomatic osteoarthritis of the knee undergoing primary robot-assisted PS TKA. All operations were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess gaps before and after PCL resection in extension and 90° knee flexion. Measurements were made after excision of the anterior cruciate ligament and prior to bone resection. There were 54 men (49.1%) and 56 women (50.9%) with a mean age of 68 years (Aims
Patients and 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
The objectives of this study were to compare postoperative pain, analgesia requirements, inpatient functional rehabilitation, time to hospital discharge, and complications in patients undergoing conventional jig-based unicompartmental knee arthroplasty (UKA) This prospective cohort study included 146 patients with symptomatic medial compartment knee osteoarthritis undergoing primary UKA performed by a single surgeon. This included 73 consecutive patients undergoing conventional jig-based mobile bearing UKA, followed by 73 consecutive patients receiving robotic-arm assisted fixed bearing UKA. All surgical procedures were performed using the standard medial parapatellar approach for UKA, and all patients underwent the same postoperative rehabilitation programme. Postoperative pain scores on the numerical rating scale and opiate analgesia consumption were recorded until discharge. Time to attainment of predefined functional rehabilitation outcomes, hospital discharge, and postoperative complications were recorded by independent observers.Aims
Patients and Methods
The primary aim of this study was to determine the surgical team’s
learning curve for introducing robotic-arm assisted unicompartmental
knee arthroplasty (UKA) into routine surgical practice. The secondary
objective was to compare accuracy of implant positioning in conventional
jig-based UKA versus robotic-arm assisted UKA. This prospective single-surgeon cohort study included 60 consecutive
conventional jig-based UKAs compared with 60 consecutive robotic-arm
assisted UKAs for medial compartment knee osteoarthritis. Patients
undergoing conventional UKA and robotic-arm assisted UKA were well-matched
for baseline characteristics including a mean age of 65.5 years
(Aims
Patients and Methods
The objective of this study was to compare early postoperative
functional outcomes and time to hospital discharge between conventional
jig-based total knee arthroplasty (TKA) and robotic-arm assisted
TKA. This prospective cohort study included 40 consecutive patients
undergoing conventional jig-based TKA followed by 40 consecutive
patients receiving robotic-arm assisted TKA. All surgical procedures
were performed by a single surgeon using the medial parapatellar
approach with identical implant designs and standardized postoperative inpatient
rehabilitation. Inpatient functional outcomes and time to hospital
discharge were collected in all study patients.Aims
Patients and Methods
The aim of this study was to report the outcome of the non-operative
treatment of high-grade posterior cruciate ligament (PCL) injuries,
particularly Hughston grade III injuries, which have not previously
been described. This was a prospective study involving 46 consecutive patients
who were athletes with MRI-confirmed isolated PCL injuries presenting
within four weeks of injury. All had Hughston grade II (25 athletes)
or III (21 athletes) injuries. Our non-operative treatment regimen
involved initial bracing, followed by an individualised rehabilitation
programme determined by the symptoms and physical signs. The patients
were reviewed until they had returned to sports-specific training,
and were reviewed again at a mean of 5.2 years (3 to 9).Aims
Patients and Methods
The aim of this consensus was to develop a definition of post-operative
fibrosis of the knee. An international panel of experts took part in a formal consensus
process composed of a discussion phase and three Delphi rounds.Aims
Patients and Methods
Medial unicompartmental knee arthroplasty (UKA) is associated
with successful outcomes in carefully selected patient cohorts.
We hypothesised that severity and location of patellofemoral cartilage
lesions significantly influences functional outcome after Oxford
medial compartmental knee arthroplasty. We reviewed 100 consecutive UKAs at minimum eight-year follow-up
(96 to 132). A single surgeon performed all procedures. Patients
were selected based on clinical and plain radiographic assessment.
All patients had end-stage medial compartment osteoarthritis (OA)
with sparing of the lateral compartment and intact anterior cruciate ligaments.
None of the patients had end-stage patellofemoral OA, but patients
with anterior knee pain or partial thickness chondral loss were
not excluded. There were 57 male and 43 female patients. The mean
age at surgery was 69 years (41 to 82). At surgery the joint was
carefully inspected for patellofemoral chondral loss and this was documented
based on severity of cartilage loss (0 to 4 Outerbridge grading)
and topographic location (medial, lateral, central, and superior
or inferior). Functional scores collected included Oxford Knee Score
(OKS), patient satisfaction scale and University College Hospital
(UCH) knee score. Intraclass correlation was used to compare chondral
damage to outcomes.Aims
Patients and Methods
Total knee arthroplasty (TKA) is a cost effective
and extremely successful operation. As longevity increases, the demand
for primary TKA will continue to rise. The success and survivorship
of TKAs are dependent on the demographics of the patient, surgical
technique and implant-related factors. Currently the risk of failure of a TKA requiring revision surgery
ten years post-operatively is 5%. The most common indications for revision include aseptic loosening
(29.8%), infection (14.8%), and pain (9.5%). Revision surgery poses
considerable clinical burdens on patients and financial burdens
on healthcare systems. We present a current concepts review on the epidemiology of failed
TKAs using data from worldwide National Joint Registries. Cite this article:
Revision total knee arthroplasty (TKA) is a complex
procedure which carries both a greater risk for patients and greater
cost for the treating hospital than does a primary TKA. As well
as the increased cost of peri-operative investigations, blood transfusions,
surgical instrumentation, implants and operating time, there is
a well-documented increased length of stay which accounts for most
of the actual costs associated with surgery. We compared revision surgery for infection with revision for
other causes (pain, instability, aseptic loosening and fracture).
Complete clinical, demographic and economic data were obtained for
168 consecutive revision TKAs performed at a tertiary referral centre
between 2005 and 2012. Revision surgery for infection was associated with a mean length
of stay more than double that of aseptic cases (21.5 Current NHS tariffs do not fully reimburse the increased costs
of providing a revision knee surgery service. Moreover, especially
as greater costs are incurred for infected cases. These losses may
adversely affect the provision of revision surgery in the NHS. Cite this article:
Revision knee arthroplasty presents a number
of challenges, not least of which is obtaining solid primary fixation
of implants into host bone. Three anatomical zones exist within
both femur and tibia which can be used to support revision implants.
These consist of the joint surface or epiphysis, the metaphysis
and the diaphysis. The methods by which fixation in each zone can
be obtained are discussed. The authors suggest that solid fixation
should be obtained in at least two of the three zones and emphasise
the importance of pre-operative planning and implant selection. Cite this article:
The routine use of patient reported outcome measures
(PROMs) in evaluating the outcome after arthroplasty by healthcare
organisations reflects a growing recognition of the importance of
patients’ perspectives in improving treatment. Although widely embraced
in the NHS, there are concerns that PROMs are being used beyond
their means due to a poor understanding of their limitations. This paper reviews some of the current challenges in using PROMs
to evaluate total knee arthroplasty. It highlights alternative methods
that have been used to improve the assessment of outcome. Cite this article:
Accurate, reproducible outcome measures are essential
for the evaluation of any orthopaedic procedure, in both clinical
practice and research. Commonly used patient-reported outcome measures (PROMs) have
drawbacks such as ‘floor’ and ‘ceiling’ effects, limitations of
worldwide adaptability and an inability to distinguish pain from
function. They are also unable to measure the true outcome of an
intervention rather than a patient’s perception of that outcome. Performance-based functional outcome tools may address these
problems. It is important that both clinicians and researchers are
aware of these measures when dealing with high-demand patients,
using a new intervention or implant, or testing a new rehabilitation
protocol. This article provides an overview of some of the clinically-validated
performance-based functional outcome tools used in the assessment
of patients undergoing hip and knee surgery. Cite this article:
Substantial healthcare resources have been devoted
to computer navigation and patient-specific instrumentation systems
that improve the reproducibility with which neutral mechanical alignment
can be achieved following total knee replacement (TKR). This choice of
alignment is based on the long-held tenet that the alignment of
the limb post-operatively should be within 3° of a neutral mechanical
axis. Several recent studies have demonstrated no significant difference
in survivorship when comparing well aligned Review of the literature suggests that a neutral mechanical axis
remains the optimal guide to alignment. Cite this article:
In this paper we make the case for the use of
single-stage revision for infected knee arthroplasty.
Radiological assessment of total and unicompartmental
knee replacement remains an essential part of routine care and follow-up.
Appreciation of the various measurements that can be identified
radiologically is important. It is likely that routine plain radiographs
will continue to be used, although there has been a trend towards
using newer technologies such as CT, especially in a failing knee,
where it provides more detailed information, albeit with a higher
radiation exposure. The purpose of this paper is to outline the radiological parameters
used to evaluate knee replacements, describe how these are measured
or classified, and review the current literature to determine their
efficacy where possible.
This review summarises the opinions and conclusions
reached from a symposium on infected total knee replacement (TKR)
held at the British Association of Surgery of the Knee (BASK) annual
meeting in 2011. The National Joint Registry for England and Wales
reported 5082 revision TKRs in 2010, of which 1157 (23%) were caused
by infection. The diagnosis of infection beyond the acute post-operative
stage relies on the identification of the causative organism by
aspiration and analysis of material obtained at arthroscopy. Ideal
treatment then involves a two-stage surgical procedure with extensive
debridement and washout, followed by antibiotics. An articulating
or non-articulating drug-eluting cement spacer is used prior to
implantation of the revision prosthesis, guided by the serum level
of inflammatory markers. The use of a single-stage revision is gaining popularity
and we would advocate its use in certain patients where the causative
organism is known, no sinuses are present, the patient is not immunocompromised,
and there is no radiological evidence of component loosening or
osteitis. It is our opinion that single-stage revision produces high-quality
reproducible results and will soon achieve the same widespread acceptance
as it does in infected hip arthroplasty.
The PROSTALAC functional spacer is made of antibiotic-loaded acrylic cement but has a small metal-on-polythene articular surface. We have used it as an interim spacer in two-stage exchange arthroplasty for infected total knee replacement. PROSTALAC allows continuous rehabilitation between stages as it maintains good alignment and stability of the knee and a reasonable range of movement. It also helps to maintain the soft-tissue planes, which facilitates the second-stage procedure. We reviewed 45 consecutive patients, treated over a period of nine years. The mean follow-up was for 48 months (20 to 112). At final review, there was no evidence of infection in 41 patients (91%); only one had a recurrent infection with the same organism. There was improvement in the Hospital for Special Surgery knee score between stages and at final review. The range of movement was maintained between stages. Complications were primarily related to the extensor mechanism and stability of the knee between stages. Both of these problems decreased with refinement of the design of the implant. The rate of cure of the infection in our patients was similar to that using other methods. Movement of the knee does not appear to hinder control of infection.
We present a patient with an arteriovenous fistula of the peroneal artery acquired after a left dome tibial osteotomy with midshaft fibular osteotomy. He had subsequently had a total knee replacement on that side. The arteriovenous malformation was only diagnosed when he represented with symptoms and signs of venous hypertension with sterile recurrent haemarthroses in the left knee. Percutaneous obliteration of the fistula, by a combination of coil embolisation and balloon occlusion, cured the symptoms.
