Aims. This study reports on the medium- to long-term implant survivorship
and patient-reported outcomes for the Avon patellofemoral joint
(PFJ) arthroplasty. Patients and Methods. A total of 558 Avon PFJ arthroplasties in 431 patients, with
minimum two-year follow-up, were identified from a prospective database.
Patient-reported outcomes and implant survivorship were analyzed,
with follow-up of up to 18 years. Results. Outcomes were recorded for 483 implants (368 patients), representing
an 86% follow-up rate. The median postoperative Oxford Knee Score
(0 to 48 scale) was 35 (interquartile range (IQR) 25.5 to 43) and
the median Western Ontario and McMaster Universities Osteoarthritis
Index (WOMAC, 0 to 100 scale) was 35 (IQR 25 to 53) at two years.
There were 105 revisions, 61 (58%) for progression of osteoarthritis.
All documented revisions were to primary knee systems without augmentation.
The implant survival rate was 77.3% (95% confidence interval (CI)
72.4 to 81.7, number at risk 204) at ten years and 67.4% (95% CI
72.4 to 81.7 number at risk 45) at 15 years. Regression analysis
of explanatory data variable showed that cases performed in the
last nine years had improved survival compared with the first nine
years of the cohort, but the individual
The tibial component of total knee arthroplasty can either be an all-polyethylene (AP) implant or a metal-backed (MB) implant. This study aims to compare the five-year functional outcomes of AP tibial components to MB components in patients aged over 70 years. Secondary aims are to compare quality of life, implant survivorship, and cost-effectiveness. A group of 130 patients who had received an AP tibial component were matched for demographic factors of age, BMI, American Society of Anesthesiologists (ASA) grade, sex, and preoperative Knee Society Score (KSS) to create a comparison group of 130 patients who received a MB tibial component. Functional outcome was assessed prospectively by KSS, quality of life by 12-Item Short-Form Health Survey questionnaire (SF-12), and range of motion (ROM), and implant survivorships were compared. The SF six-dimension (6D) was used to calculate the incremental cost effectiveness ratio (ICER) for AP compared to MB tibial components using quality-adjusted life year methodology.Aims
Methods
To perform an incremental cost-utility analysis and assess the impact of differential costs and case volume on the cost-effectiveness of robotic arm-assisted unicompartmental knee arthroplasty (rUKA) compared to manual (mUKA). This was a five-year follow-up study of patients who were randomized to rUKA (n = 64) or mUKA (n = 65). Patients completed the EuroQol five-dimension questionnaire (EQ-5D) preoperatively, and at three months and one, two, and five years postoperatively, which was used to calculate quality-adjusted life years (QALYs) gained. Costs for the primary and additional surgery and healthcare costs were calculated.Aims
Methods
Spinal anaesthesia has seen increased use in contemporary primary total knee arthroplasties (TKAs). However, controversy exists about the benefits of spinal in comparison to general anaesthesia in primary TKAs. This study aimed to investigate the pain control, length of stay (LOS), and complications associated with spinal versus general anaesthesia in primary TKAs from a single, high-volume academic centre. We retrospectively identified 17,690 primary TKAs (13,297 patients) from 2001 to 2016 using our institutional total joint registry, where 52% had general anaesthesia and 48% had spinal anaesthesia. Baseline characteristics were similar between cohorts with a mean age of 68 years (SD 10), 58% female (n = 7,669), and mean BMI of 32 kg/m2 (SD 7). Pain was evaluated using oral morphine equivalents (OMEs) and numerical pain rating scale (NPRS) data. Complications including 30- and 90-day readmissions were studied. Data were analyzed using an inverse probability of treatment weighted model based on propensity score that included many patient and surgical factors. Mean follow-up was seven years (2 to 18).Aims
Methods
Meniscal allograft transplantation (MAT) for patients with symptomatic meniscal loss has demonstrated good clinical results and survivorship. Factors that affect both functional outcome and survivorship have been reported in the literature. These are typically single-centre case series with relatively small numbers and conflicting results. Our aim was to describe an international, two-centre case series, and identify factors that affect both functional outcome and survival. We report factors that affect outcome on 526 patients undergoing MAT across two sites (one in the UK and one in Italy). Outcomes of interest were the Knee injury and Osteoarthritis Outcome Score four (KOOS4) at two years and failure rates. We performed multiple regression analysis to examine for factors affecting KOOS, and Cox proportional hazards models for survivorship.Aims
Methods
Periprosthetic joint infection (PJI) occurs in approximately 1% to 2% of total knee arthroplasties (TKA) presenting multiple challenges, such as difficulty in diagnosis, technical complexity, and financial costs. Two-stage exchange is the gold standard for treating PJI but emerging evidence suggests 'two-in-one' single-stage revision as an alternative, delivering comparable outcomes, reduced morbidity, and cost-effectiveness. This study investigates five-year results of modified single-stage revision for treatment of PJI following TKA with bone loss. Patients were identified from prospective data on all TKA patients with PJI following the primary procedure. Inclusion criteria were: revision for PJI with bone loss requiring reconstruction, and a minimum five years’ follow-up. Patients were followed up for recurrent infection and assessment of function. Tools used to assess function were Oxford Knee Score (OKS) and American Knee Society Score (AKSS).Aims
Methods
Single-shot adductor canal block (ACB) after total knee arthroplasty (TKA) for postoperative analgesia is a common modality. Patients can experience breakthrough pain when the effect of ACB wears off. Local anaesthetic infusion through an intra-articular catheter (IAC) can help manage breakthrough pain after TKA. We hypothesized that combined ACB with ropivacaine infusion through IAC is associated with better pain relief compared to ACB used alone. This study was a prospective double-blinded placebo-controlled randomized controlled trial to compare the efficacy of combined ACB+ IAC-ropivacaine infusion (study group, n = 68) versus single-shot ACB+ intra-articular normal saline placebo (control group, n = 66) after primary TKA. The primary outcome was assessment of pain, using the visual analogue scale (VAS) recorded at 6, 12, 24, and 48 hours after surgery. Secondary outcomes included active knee ROM 48 hours after surgery and additional requirement of analgesia for breakthrough pain.Aims
Methods
We retrospectively studied the major complications occurring after one- and two-stage bilateral unicompartmental knee replacements (UKR). Between 1999 and 2008, 911 patients underwent 1150 UKRs through a minimally invasive approach in our unit. Of these, 159 patients (318 UKRs) had one-stage and 80 patients (160 UKRs) had two-stage bilateral UKRs. The bilateral UKR groups were comparable in age and American Society of Anaesthesiology grade, but more women were in the two-stage group (p = 0.019). Mechanical thromboprophylaxis was used in all cases. Major complications were recorded as death, pulmonary embolus, proximal deep-vein thrombosis and adverse cardiac events within 30 days of surgery. No statistical differences between the groups were found regarding the
Unicompartmental knee arthroplasty (UKA) is a bone-preserving treatment option for osteoarthritis localized to a single compartment in the knee. The success of the procedure is sensitive to patient selection and alignment errors. Robotic arm-assisted UKA provides technological assistance to intraoperative bony resection accuracy, which is thought to improve ligament balancing. This paper presents the five-year outcomes of a comparison between manual and robotically assisted UKAs. The trial design was a prospective, randomized, parallel, single-centre study comparing surgical alignment in patients undergoing UKA for the treatment of medial compartment osteoarthritis (ISRCTN77119437). Participants underwent surgery using either robotic arm-assisted surgery or conventional manual instrumentation. The primary outcome measure (surgical accuracy) has previously been reported, and, along with secondary outcomes, were collected at one-, two-, and five-year timepoints. Analysis of five-year results and longitudinal analysis for all timepoints was performed to compare the two groups.Aims
Methods
The objective of this study was to compare the two-year migration pattern and clinical outcomes of a total knee arthroplasty (TKA) with an asymmetrical tibial design (Persona PS) and a well-proven TKA with a symmetrical tibial design (NexGen LPS). A randomized controlled radiostereometric analysis (RSA) trial was conducted including 75 cemented posterior-stabilized TKAs. Implant migration was measured with RSA. Maximum total point motion (MTPM), translations, rotations, clinical outcomes, and patient-reported outcome measures (PROMs) were assessed at one week postoperatively and at three, six, 12, and 24 months postoperatively.Aims
Methods
Debate continues regarding the optimum management of periprosthetic distal femoral fractures (PDFFs). This study aims to determine which operative treatment is associated with the lowest perioperative morbidity and mortality when treating low (Su type II and III) PDFFs comparing lateral locking plate fixation (LLP-ORIF) or distal femoral arthroplasty (DFA). This was a retrospective cohort study of 60 consecutive unilateral (PDFFs) of Su types II (40/60) and III (20/60) in patients aged ≥ 60 years: 33 underwent LLP-ORIF (mean age 81.3 years (SD 10.5), BMI 26.7 (SD 5.5); 29/33 female); and 27 underwent DFA (mean age 78.8 years (SD 8.3); BMI 26.7 (SD 6.6); 19/27 female). The primary outcome measure was reoperation. Secondary outcomes included perioperative complications, calculated blood loss, transfusion requirements, functional mobility status, length of acute hospital stay, discharge destination and mortality. Kaplan-Meier survival analysis was performed. Cox multivariate regression analysis was performed to identify risk factors for reoperation after LLP-ORIF.Aims
Methods
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). A radiological analysis of 500 healthy and 500 osteoarthritic (OA) knees was used to assess the applicability of the CPAK classification. CPAK comprises nine phenotypes based on the arithmetic HKA (aHKA) that estimates constitutional limb alignment and joint line obliquity (JLO). Intraoperative balance was compared within each phenotype in a cohort of 138 computer-assisted TKAs randomized to KA or MA. Primary outcomes included descriptive analyses of healthy and OA groups per CPAK type, and comparison of balance at 10° of flexion within each type. Secondary outcomes assessed balance at 45° and 90° and bone recuts required to achieve final knee balance within each CPAK type.Aims
Methods
This study aims to determine the proportion of patients with end-stage knee osteoarthritis (OA) possibly suitable for partial (PKA) or combined partial knee arthroplasty (CPKA) according to patterns of full-thickness cartilage loss and anterior cruciate ligament (ACL) status. A cross-sectional analysis of 300 consecutive patients (mean age 69 years (SD 9.5, 44 to 91), mean body mass index (BMI) 30.6 (SD 5.5, 20 to 53), 178 female (59.3%)) undergoing total knee arthroplasty (TKA) for Kellgren-Lawrence grade ≥ 3 knee OA was conducted. The point of maximal tibial bone loss on preoperative lateral radiographs was determined as a percentage of the tibial diameter. At surgery, Lachman’s test and ACL status were recorded. The presence of full-thickness cartilage loss within 16 articular surface regions (two patella, eight femoral, six tibial) was recorded.Aims
Methods
Total knee arthroplasty is an established treatment for knee osteoarthritis with excellent long-term results, but there remains controversy about the role of uncemented prostheses. We present the long-term results of a randomized trial comparing an uncemented tantalum metal tibial component with a conventional cemented component of the same implant design. Patients under the age of 70 years with symptomatic osteoarthritis of the knee were randomized to receive either an uncemented tantalum metal tibial monoblock component or a standard cemented modular component. The mean age at time of recruitment to the study was 63 years (50 to 70), 46 (51.1%) knees were in male patients, and the mean body mass index was 30.4 kg/m2 (21 to 36). The same cruciate retaining total knee system was used in both groups. All patients received an uncemented femoral component and no patients had their patella resurfaced. Patient outcomes were assessed preoperatively and postoperatively using the modified Oxford Knee Score, Knee Society Score, and 12-Item Short-Form Health Survey questionnaire (SF-12) score. Radiographs were analyzed using the American Knee Society Radiograph Evaluation score. Operative complications, reoperations, or revision surgery were recorded. A total of 90 knees were randomized and at last review 77 knees were assessed. In all, 11 patients had died and two were lost to follow-up.Aims
Methods
A pragmatic, single-centre, double-blind randomized clinical trial was conducted in a NHS teaching hospital to evaluate whether there is a difference in functional knee scores, quality-of-life outcome assessments, and complications at one-year after intervention between total knee arthroplasty (TKA) and patellofemoral arthroplasty (PFA) in patients with severe isolated patellofemoral arthritis. This parallel, two-arm, superiority trial was powered at 80%, and involved 64 patients with severe isolated patellofemoral arthritis. The primary outcome measure was the functional section of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 months. Secondary outcomes were the full 24-item WOMAC, Oxford Knee Score (OKS), American Knee Society Score (AKSS), EuroQol five dimension (EQ-5D) quality-of-life score, the University of California, Los Angeles (UCLA) Physical Activity Rating Scale, and complication rates collected at three, six, and 12 months. For longer-term follow-up, OKS, EQ-5D, and self-reported satisfaction score were collected at 24 and 60 months.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 examine whether tourniquet use can improve perioperative blood loss, early function recovery, and pain after primary total knee arthroplasty (TKA) in the setting of multiple-dose intravenous tranexamic acid. This was a prospective, randomized clinical trial including 180 patients undergoing TKA with multiple doses of intravenous tranexamic acid. One group was treated with a tourniquet during the entire procedure, the second group received a tourniquet during cementing, and the third group did not receive a tourniquet. All patients received the same protocol of intravenous tranexamic acid (20 mg/kg) before skin incision, and three and six hours later (10 mg/kg). The primary outcome measure was perioperative blood loss. Secondary outcome measures were creatine kinase (CK), CRP, interleukin-6 (IL-6), visual analogue scale (VAS) pain score, limb swelling ratio, quadriceps strength, straight leg raising, range of motion (ROM), American Knee Society Score (KSS), and adverse events.Aims
Methods
It is unknown whether kinematic alignment (KA) objectively improves knee balance in total knee arthroplasty (TKA), despite this being the biomechanical rationale for its use. This study aimed to determine whether restoring the constitutional alignment using a restrictive KA protocol resulted in better quantitative knee balance than mechanical alignment (MA). We conducted a randomized superiority trial comparing patients undergoing TKA assigned to KA within a restrictive safe zone or MA. Optimal knee balance was defined as an intercompartmental pressure difference (ICPD) of 15 psi or less using a pressure sensor. The primary endpoint was the mean intraoperative ICPD at 10° of flexion prior to knee balancing. Secondary outcomes included balance at 45° and 90°, requirements for balancing procedures, and presence of tibiofemoral lift-off.Aims
Methods
The use of the haptically bounded saw blades in robotic-assisted total knee arthroplasty (RTKA) can potentially help to limit surrounding soft-tissue injuries. However, there are limited data characterizing these injuries for cruciate-retaining (CR) TKA with the use of this technique. The objective of this cadaver study was to compare the extent of soft-tissue damage sustained through a robotic-assisted, haptically guided TKA (RATKA) A total of 12 fresh-frozen pelvis-to-toe cadaver specimens were included. Four surgeons each prepared three RATKA and three MTKA specimens for cruciate-retaining TKAs. A RATKA was performed on one knee and a MTKA on the other. Postoperatively, two additional surgeons assessed and graded damage to 14 key anatomical structures in a blinded manner. Kruskal–Wallis hypothesis tests were performed to assess statistical differences in soft-tissue damage between RATKA and MTKA cases.Objectives
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 aim of this study was to determine the general postoperative opioid consumption and rate of appropriate disposal of excess opioid prescriptions in patients undergoing primary unilateral total knee arthroplasty (TKA). In total, 112 patients undergoing surgery with one of eight arthroplasty surgeons at a single specialty hospital were prospectively enrolled. Three patients were excluded for undergoing secondary procedures within six weeks. Daily pain levels and opioid consumption, quantity, and disposal patterns for leftover medications were collected for six weeks following surgery using a text-messaging platform.Aims
Patients and Methods
This study compares the PFC total knee arthroplasty (TKA) system in a prospective randomized control trial (RCT) of the mobile-bearing rotating-platform (RP) TKA against the fixed-bearing (FB) TKA. This is the largest RCT with the longest follow-up where cruciate-retaining PFC total knee arthroplasties are compared in a non-bilateral TKA study. A total of 167 patients (190 knees with 23 bilateral cases), were recruited prospectively and randomly assigned, with 91 knees receiving the RP and 99 knees receiving FB. The mean age was 65.5 years (48 to 82), the mean body mass index (BMI) was 29.7 kg/m2 (20 to 52) and 73 patients were female. The Knee Society Score (KSS), Knee Society Functional Score (KSFS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and 12-Item Short-Form Health Survey Physical and Mental Component Scores (SF-12 PCS, SF-12 MCS) were gathered and recorded preoperatively, at five-years’ follow-up, and at ten years’ follow-up. Additionally, Knee Injury and Osteoarthritis Outcome Scores (KOOS) were collected at five- and ten-year follow-ups. The prevalence of radiolucent lines (RL) on radiographs and implant survival were recorded at five- and ten-year follow-ups.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
Unicompartmental knee arthroplasty (UKA) has been successfully
performed in the United States healthcare system on outpatients.
Despite differences in healthcare structure and financial environment,
we hypothesised that it would be feasible to replicate this success
and perform UKA with safe day of surgery discharge within the NHS,
in the United Kingdom. This has not been reported in any other United
Kingdom centres. We report our experience of implementing a pathway to allow safe
day of surgery discharge following UKA. Data were prospectively
collected on 72 patients who underwent UKA as a day case between
December 2011 and September 2015. Aims
Patients and Methods
The aim of this study was to compare the effectiveness of a femoral
nerve block and a periarticular infiltration in the management of
early post-operative pain after total knee arthroplasty (TKA). A pragmatic, single centre, two arm parallel group, patient blinded,
randomised controlled trial was undertaken. All patients due for
TKA were eligible. Exclusion criteria included contraindications
to the medications involved in the study and patients with a neurological
abnormality of the lower limb. Patients received either a femoral
nerve block with 75 mg of 0.25% levobupivacaine hydrochloride around
the nerve, or periarticular infiltration with 150 mg of 0.25% levobupivacaine
hydrochloride, 10 mg morphine sulphate, 30 mg ketorolac trometamol
and 0.25 mg of adrenaline all diluted with 0.9% saline to make a
volume of 150 ml.Aims
Patients and Methods
The Bereiter trochleoplasty has been used in our unit for 12
years to manage recurrent patellar instability in patients with
severe trochlea dysplasia. The aim of this study was to document
the outcome of a large consecutive cohort of patients who have undergone
this operation. Between June 2002 and August 2013, 214 consecutive trochleoplasties
were carried out in 185 patients. There were 133 women and 52 men
with a mean age of 21.3 years (14 to 38). All patients were offered
yearly clinical and radiological follow-up. They completed the following
patient reported outcome scores (PROMs): International Knee Documentation
Committee subjective scale, the Kujala score, the Western Ontario
and McMaster Universities Arthritis Index score and the short-form
(SF)-12. Aims
Patients and Methods
This prospective randomised controlled trial was designed to
evaluate the outcome of both the MRI- and CT-based patient-specific
matched guides (PSG) from the same manufacturer. A total of 137 knees in 137 patients (50 men, 87 women) were
included, 67 in the MRI- and 70 in the CT-based PSG group. Their
mean age was 68.4 years (47.0 to 88.9). Outcome was expressed as
the biomechanical limb alignment (centre hip-knee-ankle: HKA-axis)
achieved post-operatively, the position of the individual components
within 3° of the pre-operatively planned alignment, correct planned
implant size and operative data (e.g. operating time and blood loss).Aims
Patients and Methods
The aim of this study was to examine the results of revision
total knee arthroplasty (TKA) undertaken for stiffness in the absence
of sepsis or loosening. We present the results of revision surgery for stiff TKA in 48
cases (35 (72.9%) women and 13 (27.1%) men). The mean age at revision
surgery was 65.5 years (42 to 83). All surgeries were performed
by a single surgeon. Stiffness was defined as an arc of flexion
of <
70° or a flexion contracture of >
15°. The changes in the
range of movement (ROM) and the Western Ontario and McMasters Osteoarthritis
index scores (WOMAC) were recorded.Aims
Patients and Methods
Unicompartmental knee arthroplasty (UKA) has
advantages over total knee arthroplasty but national joint registries report
a significantly higher revision rate for UKA. As a result, most
surgeons are highly selective, offering UKA only to a small proportion
(up to 5%) of patients requiring arthroplasty of the knee, and consequently
performing few each year. However, surgeons with large UKA practices
have the lowest rates of revision. The overall size of the practice
is often beyond the surgeon’s control, therefore case volume may
only be increased by broadening the indications for surgery, and
offering UKA to a greater proportion of patients requiring arthroplasty
of the knee. The aim of this study was to determine the optimal UKA usage
(defined as the percentage of knee arthroplasty practice comprised
by UKA) to minimise the rate of revision in a sample of 41 986 records
from the for National Joint Registry for England and Wales (NJR). UKA usage has a complex, non-linear relationship with the rate
of revision. Acceptable results are achieved with the use of 20%
or more. Optimal results are achieved with usage between 40% and
60%. Surgeons with the lowest usage (up to 5%) have the highest
rates of revision. With optimal usage, using the most commonly used
implant, five-year survival is 96% (95% confidence interval (CI)
94.9 to 96.0), compared with 90% (95% CI 88.4 to 91.6) with low
usage (5%) previously considered ideal. The rate of revision of UKA is highest with low usage, implying
the use of narrow, and perhaps inappropriate, indications. The widespread
use of broad indications, using appropriate implants, would give
patients the advantages of UKA, without the high rate of revision. Cite this article:
In this study we randomised 140 patients who
were due to undergo primary total knee arthroplasty (TKA) to have the
procedure performed using either patient-specific cutting guides
(PSCG) or conventional instrumentation (CI). The primary outcome measure was the mechanical axis, as measured
at three months on a standing long-leg radiograph by the hip–knee–ankle
(HKA) angle. This was undertaken by an independent observer who
was blinded to the instrumentation. Secondary outcome measures were
component positioning, operating time, Knee Society and Oxford knee
scores, blood loss and length of hospital stay. A total of 126 patients (67 in the CI group and 59 in the PSCG
group) had complete clinical and radiological data. There were 88
females and 52 males with a mean age of 69.3 years (47 to 84) and
a mean BMI of 28.6 kg/m2 (20.2 to 40.8). The mean HKA
angle was 178.9° (172.5 to 183.4) in the CI group and 178.2° (172.4
to 183.4) in the PSCG group (p = 0.34). Outliers were identified
in 22 of 67 knees (32.8%) in the CI group and 19 of 59 knees (32.2%)
in the PSCG group (p = 0.99). There was no significant difference
in the clinical results (p = 0.95 and 0.59, respectively). Operating time,
blood loss and length of hospital stay were not significantly reduced
(p = 0.09, 0.58 and 0.50, respectively) when using PSCG. The use of PSCG in primary TKA did not reduce the proportion
of outliers as measured by post-operative coronal alignment. Cite this article:
Worldwide rates of primary and revision total
knee arthroplasty (TKA) are rising due to increased longevity of
the population and the burden of osteoarthritis. Revision TKA is a technically demanding procedure generating
outcomes which are reported to be inferior to those of primary knee
arthroplasty, and with a higher risk of complication. Overall, the
rate of revision after primary arthroplasty is low, but the number
of patients currently living with a TKA suggests a large potential
revision healthcare burden. Many patients are now outliving their prosthesis, and consideration
must be given to how we are to provide the necessary capacity to
meet the rising demand for revision surgery and how to maximise
patient outcomes. The purpose of this review was to examine the epidemiology of,
and risk factors for, revision knee arthroplasty, and to discuss
factors that may enhance patient outcomes. Cite this article:
The relationship between post-operative bone
density and subsequent failure of total knee replacement (TKR) is
not known. This retrospective study aimed to determine the relationship
between bone density and failure, both overall and according to
failure mechanism. All 54 aseptic failures occurring in 50 patients
from 7760 consecutive primary cemented TKRs between 1983 and 2004
were matched with non-failing TKRs, and 47 failures in 44 patients
involved tibial failures with the matching characteristics of age
(65.1 for failed and 69.8 for non-failed), gender (70.2% female), diagnosis
(93.6% OA), date of operation, bilaterality, pre-operative alignment
(0.4 and 0.3 respectively), and body mass index (30.2 and 30.0 respectively).
In each case, the density of bone beneath the tibial component was assessed
at each follow-up interval using standardised, calibrated radiographs.
Failing knees were compared with controls both overall and, as a
subgroup analysis, by failure mechanism. Knees were compared with
controls using univariable linear regression. Significant and continuous elevation in tibial density was found
in knees that eventually failed by medial collapse (p <
0.001)
and progressive radiolucency (p <
0.001) compared with controls,
particularly in the medial region of the tibia. Knees failing due
to ligamentous instability demonstrated an initial decline in density
(p = 0.0152) followed by a non-decreasing density over time (p =
0.034 for equivalence). Non-failing knees reported a decline in
density similar to that reported previously using dual-energy x-ray
absorptiometry (DEXA). Differences between failing and non-failing
knees were observable as early as two months following surgery.
This tool may be used to identify patients at risk of failure following
TKR, but more validation work is needed. Cite this article:
Mortality rates reported by the National Joint Registry for England
and Wales (NJR) were higher following cemented total knee replacement
(TKR) compared with uncemented procedures. The aim of this study
is to examine and compare the effects of cemented and uncemented
TKR on the activation of selected markers of inflammation, endothelium,
and coagulation, and on the activation of selected cytokines involved
in the various aspects of the systemic response following surgery. This was a single centre, prospective, case-control study. Following
enrolment, blood samples were taken pre-operatively, and further
samples were collected at day one and day seven post-operatively.
One patient in the cemented group developed a deep-vein thrombosis
confirmed on ultrasonography and was excluded, leaving 19 patients
in this cohort (mean age 67.4, (Objective
Methods
The strain on clinic and surgeon resources resulting
from a rise in demand for total knee replacement (TKR) requires reconsideration
of when and how often patients need to be seen for follow-up. Surgeons
will otherwise require increased paramedical staff or need to limit
the number of TKRs they undertake. We reviewed the outcome data
of 16 414 primary TKRs undertaken at our centre to determine the
time to re-operation for any reason and for specific failure mechanisms.
Peak risk years for failure were determined by comparing the conditional
probability of failure, the number of failures divided by the total
number of TKRs cases, for each year. The median times to failure
for the most common failure mechanisms were 4.9 years (interquartile
range (IQR) 1.7 to 10.7) for femoral and tibial loosening, 1.9 years
(IQR 0.8 to 3.9) for infection, 3.1 years (IQR 1.6 to 5.5) for tibial
collapse and 5.6 years (IQR 3.4 to 9.3) for instability. The median
time to failure for all revisions was 3.3 years (IQR 1.2 to 8.5),
with an overall revision rate of 1.7% (n = 282). Results from our
patient population suggest that patients be seen for follow-up at
six months, one year, three years, eight years, 12 years, and every
five years thereafter. Patients with higher pain in the early post-operative
period or high body mass index (≥ 41 kg/m2) should be
monitored more closely. Cite this article:
We report the results of revision total knee
replacement (TKR) in 26 patients with major metaphyseal osteolytic defects
using 29 trabecular metal cones in conjunction with a rotating hinged
total knee prosthesis. The osteolytic defects were types II and
III (A or B) according to the Anderson Orthopaedic Research Institute
(AORI) classification. The mean age of the patients was 72 years
(62 to 84) and there were 15 men and 11 women. In this series patients had
undergone a mean of 2.34 previous total knee arthroplasties. The
main objective was to restore anatomy along with stability and function
of the knee joint to allow immediate full weight-bearing and active
knee movement. Outcomes were measured using Knee Society scores,
Oxford knee scores, range of movement of the knee and serial radiographs.
Patients were followed for a mean of 36 months (24 to 49). The mean
Oxford knee clinical scores improved from 12.83 (10 to 15) to 35.20
(32 to 38) (p <
0.001) and mean American Knee Society scores
improved from 33.24 (13 to 36) to 81.12 (78 to 86) (p <
0.001).
No radiolucent lines suggestive of loosening were seen around the trabecular
metal cones, and by one year all the radiographs showed good osteo-integration.
There was no evidence of any collapse or implant migration. Our
early results confirm the findings of others that trabecular metal
cones offer a useful way of managing severe bone loss in revision
TKR. Cite this article:
Pain, swelling and inflammation are expected
during the recovery from total knee arthroplasty (TKA) surgery.
The severity of these factors and how a patient copes with them
may determine the ultimate outcome of a TKA. Cryotherapy and compression
are frequently used modalities to mitigate these commonly experienced
sequelae. However, their effect on range of motion, functional testing,
and narcotic consumption has not been well-studied. A prospective, multi-center, randomised trial was conducted to
evaluate the effect of a cryopneumatic device on post-operative
TKA recovery. Patients were randomised to treatment with a cryopneumatic
device or ice with static compression. A total of 280 patients were
enrolled at 11 international sites. Both treatments were initiated
within three hours post-operation and used at least four times per
day for two weeks. The cryopneumatic device was titrated for cooling
and pressure by the patient to their comfort level. Patients were evaluated by physical therapists blinded to the
treatment arm. Range of motion (ROM), knee girth, six minute walk
test (6MWT) and timed up and go test (TUG) were measured pre-operatively,
two- and six-weeks post-operatively. A visual analog pain score
and narcotic consumption was also measured post-operatively. At two weeks post-operatively, both the treatment and control
groups had diminished ROM and function compared to pre-operatively.
Both groups had increased knee girth compared to pre- operatively.
There was no significant difference in ROM, 6MWT, TUG, or knee girth
between the 2 groups. We did find a significantly lower amount of
narcotic consumption (509 mg morphine equivalents) in the treatment
group compared with the control group (680 mg morphine equivalents)
at up to two weeks postop, when the cryopneumatic device was being
used (p <
0.05). Between two and six weeks, there was no difference
in the total amount of narcotics consumed between the two groups.
At six weeks, there was a trend toward a greater distance walked
in the 6MWT in the treatment group (29.4 meters A cryopneumatic device used after TKA appeared to decrease the
need for narcotic medication from hospital discharge to 2 weeks
post-operatively. There was also a trend toward a greater distance
walked in the 6MWT. Patient satisfaction with the cryopneumatic
cooling regimen was significantly higher than with the control treatment.
The incidence of anterior knee pain following
total knee replacement (TKR) is reported to be as high as 49%. The source
of the pain is poorly understood but the soft tissues around the
patella have been implicated. In theory circumferential electrocautery denervates the patella
thereby reducing efferent pain signals. However, there is mixed
evidence that this practice translates into improved outcomes. We aimed to investigate the clinical effect of intra-operative
circumpatellar electrocautery in patients undergoing TKR using the
LCS mobile bearing or Kinemax fixed bearing TKR. A total of 200
patients were randomised to receive either circumpatellar electrocautery
(diathermy) or not (control). Patients were assessed by visual analogue
scale (VAS) for anterior knee pain and Oxford knee score (OKS) pre-operatively
and three months, six months and one year post-operatively. Patients
and assessors were blinded. There were 91 patients in the diathermy group and 94 in the control.
The mean VAS improvement at one year was 3.9 in both groups (control;
-10 to 6, diathermy; We found no relevant effect of patellar electrocautery on either
VAS anterior knee pain or OKS for patients undergoing LCS and Kinemax
TKR.
As part of the national initiative to reduce
waiting times for joint replacement surgery in Wales, the Cardiff
and Vale NHS Trust referred 224 patients to the NHS Treatment Centre
in Weston-Super-Mare for total knee replacement (TKR). A total of
258 Kinemax TKRs were performed between November 2004 and August
2006. Of these, a total of 199 patients (232 TKRs, 90%) have been
followed up for five years. This cohort was compared with 258 consecutive
TKRs in 250 patients, performed at Cardiff and Vale Orthopaedic
Centre (CAVOC) over a similar time period. The five year cumulative
survival rate was 80.6% (95% confidence interval (CI) 74.0 to 86.0)
in the Weston-Super-Mare cohort and 95.0% (95% CI 90.2 to 98.2)
in the CAVOC cohort with revision for any reason as the endpoint.
The relative risk for revision at Weston-Super-Mare compared with
CAVOC was 3.88 (p <
0.001). For implants surviving five years,
the mean Oxford knee scores (OKS) and mean EuroQol (EQ-5D) scores
were similar (OKS: Weston-Super-Mare 29 (2 to 47) The results show a higher revision rate for patients operated
at Weston-Super-Mare Treatment Centre, with a reduction in functional
outcome and quality of life after revision. This further confirms
that patients moved from one area to another for joint replacement
surgery fare poorly.
We have shown in a previous study that patients with combined lesions of the anterior cruciate (ACL) and medial collateral ligaments (MCL) had similar anteroposterior (AP) but greater valgus laxity at 30° after reconstruction of the ACL when compared with patients who had undergone reconstruction of an isolated ACL injury. The present study investigated the same cohort of patients after a minimum of three years to evaluate whether the residual valgus laxity led to a poorer clinical outcome. Each patient had undergone an arthroscopic double-bundle ACL reconstruction using a semitendinosus-gracilis graft. In the combined ACL/MCL injury group, the grade II medial collateral ligament injury was not treated. At follow-up, AP laxity was measured using a KT-2000 arthrometer, while valgus laxity was evaluated with Telos valgus stress radiographs and compared with the uninjured knee. We evaluated clinical outcome scores, muscle girth and time to return to activities for the two groups. Valgus stress radiographs showed statistically significant greater mean medial joint opening in the reconstructed compared with the uninjured knees (1.7 mm (
Bicruciate-stabilised total knee replacement (TKR) aims to restore normal kinematics by replicating the function of both cruciate ligaments. We performed a prospective, randomised controlled trial in which bicruciate- and posterior-stabilised TKRs were implanted in 13 and 15 osteo-arthritic knees, respectively. The mean age of the bicruciate-stabilised group was 63.9 years ( At near full extension during step-up, the bicruciate-stabilised TKR produced a higher mean PTA than the posterior-stabilised TKR, indicating that the bicruciate design at least partially restored the kinematic role of the anterior cruciate ligament. The bicruciate-stabilised TKR largely restored the pre-operative kinematics, whereas the posterior-stabilised TKR resulted in a consistently lower PTA at all activities. The PTA in the pre-operative knees was higher than in the control group during the step-up and at near full knee extension. Overall, both groups generated a more normal PTA than that seen in previous studies in high knee flexion. This suggested that both designs of TKR were more effective at replicating the kinematic role of the posterior cruciate ligament than those used in previous studies.
We identified a series of 128 patients who had unilateral open reconstruction of the anterior cruciate ligament (ACL) by a single surgeon between 1993 and 2000. In all, 79 patients were reviewed clinically and radiologically eight to 15 years after surgery. Assessment included measurement of the Lysholm and Tegner scores, the ACL quality-of-life score and the Short Form-12 score, as well as the International Knee Documentation Committee clinical assessment, measurement of laxity by the KT-1000 arthrometer, a single-leg hop test and standardised radiography of both knees using the uninjured knee as a control. Of the injured knees, 46 (57%) had definite radiological evidence of osteoarthritis (Kellgren-Lawrence grade 2 or 3), with a mean difference between the injured and non-injured knees of 1.2 grades. The median ACL quality-of-life score was 80 (interquartile range (IQR) 60 to 90), the Lysholm score 84 (IQR 74 to 95), the Short Form-12 physical component score 54 (IQR 49 to 56) and the mean Hop Index 0.94 (0.52 to 1.52). In total 58 patients were graded as normal, 20 as nearly normal and one as abnormal on the KT-1000 assessment and pivot-shift testing. Taking the worst-case scenario of assuming all non-attenders (n = 48), two septic failures and one identified unstable knee found at review to be failures, the failure rate was 40%. Only two of the patients reviewed stated that they would not have similar surgery again. Open reconstruction of the ACL gives good, durable functional results, but with a high rate of radiologically evident osteoarthritis.
This study used CT analysis to determine the rotational alignment of 39 painful and 26 painless fixed-bearing total knee replacements (TKRs) from a cohort of 740 NexGen Legacy posterior-stabilised and cruciate-retaining prostheses implanted between May 1996 and August 2003. The mean rotation of the tibial component was 4.3° of internal rotation (25.4° internal to 13.9° external rotation) in the painful group and 2.2° of external rotation (8.5° internal to 18.2° external rotation) in the painfree group (p = 0.024). In the painful group 17 tibial components were internally rotated more than 9° compared with none in the painfree group (p <
0.001). Additionally, six femoral components in the painful group were internally rotated more than 6° compared with none in the painfree group (p = 0.017). External rotational errors were not found to be associated with pain. Overall, 22 (56.4%) of the painful TKRs had internal rotational errors involving the femoral, the tibial or both components. It is estimated that at least 4.6% of all our TKRs have been implanted with significant internal rotational errors.
We present a prospective review of the two-year functional outcome of 37 Avon patellofemoral joint replacements carried out in 29 patients with a mean age of 66 years (30 to 82) between October 2002 and March 2007. No patients were lost to follow-up. This is the first independent assessment of this prosthesis using both subjective and objective analysis of outcome. At two years the median Oxford knee score was 39 (interquartile range 32 to 44), the median American Knee Society objective score was 95 (interquartile range 90 to 100), the median American Knee Society functional score was 85 (interquartile range 60 to 100), and the median Melbourne Knee score was 28 (interquartile range 21 to 30). Two patients underwent further surgery. Only one patient reported an unsatisfactory outcome. We conclude that the promising early results observed by the designing centre are reproducible and provide further support for the role of patellofemoral joint replacement.
Narrow, well-defined radiolucent lines commonly observed at the bone-implant interface of unicompartmental knee replacement tibial components have been referred to as physiological radiolucencies. These should be distinguished from pathological radiolucencies, which are poorly defined, wide and progressive, and associated with loosening and infection. We studied the incidence and clinical significance of tibial radiolucent lines in 161 Oxford unicondylar knee replacements five years after surgery. All the radiographs were aligned with fluoroscopic control to obtain views parallel to the tibial tray to reveal the tibial bone-implant interface. We found that 49 knees (30%) had complete, 52 (32%) had partial and 60 (37%) had no radiolucent lines. There was no relationship between the incidence of radiolucent lines and patient factors such as gender, body mass index and activity, or operative factors including the status of the anterior cruciate ligament and residual varus deformity. Nor was any statistical relationship established between the presence of radiolucent lines and clinical outcome, particularly pain, assessed by the Oxford Knee score and the American Knee Society score. We conclude that radiolucent lines are common after Oxford unicompartmental knee replacement but that their aetiology remains unclear. Radiolucent lines were not a source of adverse symptoms or pain. Therefore, when attempting to identify a source of postoperative pain after Oxford unicompartmental knee replacement the presence of a physiological radiolucency should be ignored.
The Unispacer knee system is a cobalt-chrome self-centring tibial hemiarthroplasty device for use in the treatment of isolated medial compartment osteoarthritis of the knee. The indications for use are similar to those for high tibial osteotomy, but insertion does not require bone cuts or component fixation, and does not compromise future knee replacement surgery. A prospective study of a consecutive series of 18 patients treated with the Unispacer between June 2003 and August 2004 was carried out to determine the early clinical results of this device. The mean age of the patients was 49 years (40 to 57). A total of eight patients (44%) required revision within two years. In two patients revision to a larger spacer was required, and in six conversion to either a unicompartmental or total knee replacement was needed. At the most recent review 12 patients (66.7%) had a Unispacer remaining This study demonstrates that use of the Unispacer in isolated medial compartment osteoarthritis is associated with a high rate of revision surgery and provides unpredictable relief of pain.
We carried out a prospective study to assess the clinical outcome, complications and survival of the NexGen Legacy posterior-stabilised-Flex total knee replacement (TKR) in a consecutive series of 278 knees between May 2003 and February 2005. Mean follow-up for 259 TKRs (98.2%) was 3.8 years (3.0 to 4.8). Annual follow-up showed improvement in the Knee Society scores (paired This relatively large study indicates that the legacy posterior stabilised-Flex design provides excellent short-term outcome but warrants ongoing evaluation to confirm the long-term durability and functioning of the implant.
Pain is the main indication for performing total knee replacement (TKR). In most patients after TKR there is an improvement, but a few continue to have pain. Generally, the cause of the pain can be addressed when it is identified. However, unexplained pain can be more difficult to manage because revision surgery is likely to be unrewarding in this group. In our study of 622 cemented TKRs in 512 patients with a mean age of 69 years (23 to 90) treated between January 1995 and August 1998, we identified 24 patients (knees) with unexplained pain at six months. This group was followed for five years (data was unavailable for 18 knees) and ten patients (55.5%) went on to show an improvement without intervention. In the case of unexplained pain, management decisions must be carefully considered, but reassurance can be offered to patients that the pain will improve in more than half with time.
We studied the influence of soft-tissue releases and soft-tissue balance on the outcome of 526 total knee replacements one year after operation. The surgery had been performed by seven surgeons in five centres in the United Kingdom between October 1999 and December 2002. Balancing was carried out by five surgeons using spacers and trials and by two surgeons using a ‘balancer’ instrument. All the surgeons assessed the adequacy of their releases by taking measurements with the balancer after soft-tissue release before implanting the components. Independent observers collected the Oxford knee scores and applied the American Knee Society functional and knee scores as well as recording the range of movement of the replaced knee. These were compared with the pre-operative scores and the extent of the releases. We found differences in outcomes between minimal and extensive releases and between balanced and imbalanced knees. Knees requiring extensive soft-tissue releases showed greater change in the short-term clinical outcome without increased complications and achieved similar results at one year compared with those with less deformity pre-operatively which had required less soft-tissue release. Balancing an imbalanced knee improved the short-term knee outcome.
The shape of the flexion gap in 20 normal knees was evaluated by axial radiography of the distal femur, and the results compared with those obtained in a previous study by MRI. The observed asymmetry was reduced by 29% using radiography, with a mean value of 3.6° (1.5° to 6.3°) compared with that obtained by MRI of 5.1° (2.6° to 9.5°), a mean discrepancy of 1.49°. The results obtained by radiography and MRI showed a strong correlation (r = 0.78). Axial radiography is acceptable for the evaluation of the flexion gap and is less expensive and more comfortable to perform than MRI. Additionally, no metallic artefact occurs when the radiological method is used for assessment after arthroplasty.
Our aims were to map the tibial footprint of the posterior cruciate ligament (PCL) using MRI in patients undergoing PCL-preserving total knee replacement, and to document the disruption of this footprint as a result of the tibial cut. In 26 consecutive patients plain radiography and MRI of the knee were performed pre-operatively, and plain radiography post-operatively. The lower margin of the PCL footprint was located a mean of 1 mm (−10 to 8) above the upper aspect of the fibular head. The mean surface area was 83 mm2 (49 to 142). One-third of patients (8 of 22) had tibial cuts made below the lowest aspect of the PCL footprint (complete removal) and one-third (9 of 22) had cuts extending into the footprint (partial removal). The remaining patients (5 of 22) had footprints unaffected by the cuts, keeping them intact. Our study highlights the wide variation in the location of the tibial PCL footprint when referenced against the fibula. Proximal tibial cuts using conventional jigs resulted in the removal of a significant portion, if not all of the PCL footprint in most of the patients in our study. Our findings suggest that when performing PCL-retaining total knee replacement the tibial attachment of the PCL is often removed.
The role of modular tibial implants in total knee replacement is not fully defined. We performed a prospective randomised controlled clinical trial using radiostereophotogrammetric analysis to compare the performance of an all-polyethylene tibia with a metal-backed cruciate-retaining condylar design, PFC-∑ total knee replacement for up to 24 months. There were 51 patients who were randomised into two treatment groups. There were 10 subsequent withdrawals, leaving 21 all-polyethylene and 20 metal-backed tibial implants. No patient was lost to follow-up. There were no significant demographic differences between the groups. At two years one metal-backed implant showed migration >
1 mm, but no polyethylene implant reached this level. There was a significant increase in the SF-12 and Oxford knee scores after operation in both groups. In an uncomplicated primary total knee replacement the all-polyethylene PFC-∑ tibial prosthesis showed no statistical difference in migration from that of the metal-backed counterpart. There was no difference in the clinical results as assessed by the SF-12, the Oxford knee score, alignment or range of movement at 24 months, although these assessment measures were not statistically powered in this study.
This study describes 146 primary total knee replacements, either fully or partially coated with hydroxyapatite of which 74 knees in 68 patients were available for clinical and radiological assessment at a mean of 11.2 years (10 to 15). The global failure rate was 1.37% and survival rate with mechanical failure as the end-point was 98.14%. Radiological assessment indicated intimate contact between bone and the hydroxyapatite coating. Over time the hydroxyapatite coating appears to encourage filling of interface gaps remaining after surgery. Our results compare favourably with those of series describing cemented or porous-coated knee replacements, and suggest that fixation with hydroxyapatite is a reliable option in primary total knee replacement.
We carried out a prospective study of 118 hydroxyapatite-coated, cementless total knee replacements in patients who were ≤ 55 years of age and who had primary (92; 78%) or post-traumatic (26; 22%) osteoarthritis. The mean period of follow-up was 7.9 years (5 to 12.5). The Knee Society clinical scores improved from a pre-operative mean of 98 (0 to 137) to a mean of 185 (135 to 200) at five years, and 173 (137 to 200) at ten years. There were two revisions of the tibial component because of aseptic loosening, and one case of polyethylene wear requiring further surgery. There was no osteolysis or progressive radiological loosening of any other component. At 12 years, the overall rate of implant survival was 97.5% (excluding exchange of spacer) and 92.1% (including exchange of spacer). Cementless total knee replacement can achieve excellent long-term results in young, active patients with osteoarthritis. In contrast to total hip replacement, polyethylene wear, osteolysis and loosening of the prosthesis were not major problems for these patients, although it is possible that this observation could change with longer periods of follow-up.
Abnormal sagittal kinematics after total knee replacement (TKR) can adversely affect functional outcome. Two important determinants of knee kinematics are component geometry and the presence or absence of a posterior-stabilising mechanism (cam-post). We investigated the influence of these variables by comparing the kinematics of a TKR with a polyradial femur with a single radius design, both with and without a cam-post mechanism. We assessed 55 patients, subdivided into four groups, who had undergone a TKR one year earlier by using an established fluoroscopy protocol in order to examine their kinematics
