The December 2024 Knee Roundup. 360. looks at: Unicompartmental knee arthroplasty and total knee arthroplasty in the same patient?; Lateral unicompartmental knee arthroplasty: is it a good option?; The fate of the unresurfaced
The surgical target for optimal implant positioning in robotic-assisted total knee arthroplasty remains the subject of ongoing discussion. One of the proposed targets is to recreate the knee’s functional behaviour as per its pre-diseased state. The aim of this study was to optimize implant positioning, starting from mechanical alignment (MA), toward restoring the pre-diseased status, including ligament strain and kinematic patterns, in a patient population. We used an active appearance model-based approach to segment the preoperative CT of 21 osteoarthritic patients, which identified the osteophyte-free surfaces and estimated cartilage from the segmented bones; these geometries were used to construct patient-specific musculoskeletal models of the pre-diseased knee. Subsequently, implantations were simulated using the MA method, and a previously developed optimization technique was employed to find the optimal implant position that minimized the root mean square deviation between pre-diseased and postoperative ligament strains and kinematics.Aims
Methods
During total knee replacement (TKR), surgeons can choose whether or not to resurface the patella, with advantages and disadvantages of each approach. Recently, the National Institute for Health and Care Excellence (NICE) recommended always resurfacing the patella, rather than never doing so. NICE found insufficient evidence on selective resurfacing (surgeon’s decision based on intraoperative findings and symptoms) to make recommendations. If effective, selective resurfacing could result in optimal individualized patient care. This protocol describes a randomized controlled trial to evaluate the clinical and cost-effectiveness of primary TKR with always patellar resurfacing compared to selective patellar resurfacing. The PAtellar Resurfacing Trial (PART) is a patient- and assessor-blinded multicentre, pragmatic parallel two-arm randomized superiority trial of adults undergoing elective primary TKR for primary osteoarthritis at NHS hospitals in England, with an embedded internal pilot phase (ISRCTN 33276681). Participants will be randomly allocated intraoperatively on a 1:1 basis (stratified by centre and implant type (cruciate-retaining vs cruciate-sacrificing)) to always resurface or selectively resurface the patella, once the surgeon has confirmed sufficient patellar thickness for resurfacing and that constrained implants are not required. The primary analysis will compare the Oxford Knee Score (OKS) one year after surgery. Secondary outcomes include patient-reported outcome measures at three months, six months, and one year (Knee injury and Osteoarthritis Outcome Score, OKS, EuroQol five-dimension five-level questionnaire, patient satisfaction, postoperative complications, need for further surgery, resource use, and costs). Cost-effectiveness will be measured for the lifetime of the patient. Overall, 530 patients will be recruited to obtain 90% power to detect a four-point difference in OKS between the groups one year after surgery, assuming up to 40% resurfacing in the selective group.Aims
Methods
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 aim of this study is to evaluate whether acetabular retroversion (AR) represents a structural anatomical abnormality of the pelvis or is a functional phenomenon of pelvic positioning in the sagittal plane, and to what extent the changes that result from patient-specific functional position affect the extent of AR. A comparative radiological study of 19 patients (38 hips) with AR were compared with a control group of 30 asymptomatic patients (60 hips). CT scans were corrected for rotation in the axial and coronal planes, and the sagittal plane was then aligned to the anterior pelvic plane. External rotation of the hemipelvis was assessed using the superior iliac wing and inferior iliac wing angles as well as quadrilateral plate angles, and correlated with cranial and central acetabular version. Sagittal anatomical parameters were also measured and correlated to version measurements. In 12 AR patients (24 hips), the axial measurements were repeated after matching sagittal pelvic rotation with standing and supine anteroposterior radiographs.Aims
Methods
The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design. This was a retrospective review of 707 primary TKAs in 590 patients from a single institution, using a cementless, metal-backed patellar component with a mean follow-up of 6.9 years (2 to 12). A total of 409 TKAs were performed in 338 females and 298 TKAs in 252 males. The mean age of the patients was 63 years (34 to 87) and their mean BMI was 34.3 kg/m2 (18.8 to 64.5). The patients were chosen to undergo a cementless procedure based on age and preoperative radiological and intraoperative bone quality. Outcome was assessed using the Knee Society knee and function scores and range of motion (ROM), complications, and revisions.Aims
Methods
Nonagenarians (aged 90 to 99 years) have experienced the fastest percent decile population growth in the USA recently, with a consequent increase in the prevalence of nonagenarians living with joint arthroplasties. As such, the number of revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) in nonagenarians is expected to increase. We aimed to determine the mortality rate, implant survivorship, and complications of nonagenarians undergoing aseptic revision THAs and revision TKAs. Our institutional total joint registry was used to identify 96 nonagenarians who underwent 97 aseptic revisions (78 hips and 19 knees) between 1997 and 2018. The most common indications were aseptic loosening and periprosthetic fracture for both revision THAs and revision TKAs. Mean age at revision was 92 years (90 to 98), mean BMI was 27 kg/m2 (16 to 47), and 67% (n = 65) were female. Mean time between primary and revision was 18 years (SD 9). Kaplan-Meier survival was used for patient mortality, and compared to age- and sex-matched control populations. Reoperation risk was assessed using cumulative incidence with death as a competing risk. Mean follow-up was five years.Aims
Methods
This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates. A systematic review of MEDLINE, PubMed, and Google Scholar was performed to identify randomized controlled trials (RCTs) according to search criteria. Search terms used included: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, and patellar retaining. RCTs that compared patellar resurfacing versus unresurfaced in primary TKA were included for further analysis. Studies were evaluated using the Scottish Intercollegiate Guidelines Network assessment tool for quality and minimization of bias. Data were synthesized and meta-analysis performed.Aims
Methods
Insufficient treatment response in rheumatoid arthritis (RA) patients requires novel treatment strategies to halt disease progression. The potential benefit of combination of cytokine-inhibitors in RA is still unclear and needs further investigation. To explore the impact of combined deficiency of two major cytokines, namely interleukin (IL)-1 and IL-6, in this study double deficient mice for IL-1αβ and IL-6 were investigated in different tumour necrosis factor (TNF)-driven inflammatory bone disorders, namely peripheral arthritis and sacroiliitis, as well as systemic bone loss. Disease course, histopathological features of arthritis, and micro-CT (µCT) bone analysis of local and systemic bone loss were assessed in 15-week-old Aims
Methods
The lateral centre-edge angle (LCEA) is a plain radiological measure of superolateral cover of the femoral head. This study aims to establish the correlation between 2D radiological and 3D CT measurements of acetabular morphology, and to describe the relationship between LCEA and femoral head cover (FHC). This retrospective study included 353 periacetabular osteotomies (PAOs) performed between January 2014 and December 2017. Overall, 97 hips in 75 patients had 3D analysis by Clinical Graphics, giving measurements for LCEA, acetabular index (AI), and FHC. Roentgenographical LCEA, AI, posterior wall index (PWI), and anterior wall index (AWI) were measured from supine AP pelvis radiographs. The correlation between CT and roentgenographical measurements was calculated. Sequential multiple linear regression was performed to determine the relationship between roentgenographical measurements and CT FHC.Aims
Methods
The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck. Long-leg standing radiographs of patients undergoing realignment surgery around the knee were used. The hip-knee-ankle angle (HKA) and the vertical orientation of the femoral neck in relation to the floor were measured, prior to surgery and after osteotomy-site-union. Linear regression was performed to determine the influence of knee alignment on the vertical orientation of the femoral neck.Aims
Methods
Perthes’ disease (PD) often results in femoral head deformity and leg length discrepancy (LLD). Our objective was to analyze femoral morphology in PD patients at skeletal maturity to assess where the LLD originates, and evaluate the effect of contralateral epiphysiodesis for length equalization on proximal and subtrochanteric femoral lengths. All patients treated for PD in our institution between January 2013 and June 2020 were reviewed retrospectively. Patients with unilateral PD, LLD of ≥ 5 mm, and long-leg standing radiographs at skeletal maturity were included. Total leg length, femoral and tibial length, articulotrochanteric distance (ATD), and subtrochanteric femoral length were compared between PD side and the unaffected side. Furthermore, we compared leg length measurements between patients who did and who did not have a contralateral epiphysiodesis.Aims
Methods
Anterior cruciate ligament (ACL) rupture commonly leads to post-traumatic osteoarthritis, regardless of surgical reconstruction. This study uses standing MRI to investigate changes in contact area, contact centroid location, and tibiofemoral alignment between ACL-injured knees and healthy controls, to examine the effect of ACL reconstruction on these parameters. An upright, open MRI was used to directly measure tibiofemoral contact area, centroid location, and alignment in 18 individuals with unilateral ACL rupture within the last five years. Eight participants had been treated nonoperatively and ten had ACL reconstruction performed within one year of injury. All participants were high-functioning and had returned to sport or recreational activities. Healthy contralateral knees served as controls. Participants were imaged in a standing posture with knees fully extended.Aims
Methods
Recent total knee arthroplasty (TKA) designs have featured more anatomical morphologies and shorter tibial keels. However, several reports have raised concerns about the impact of these modifications on implant longevity. The aim of this study was to report the early performance of a modern, cemented TKA design. All patients who received a primary, cemented TKA between 2012 and 2017 with a minimum two-year follow-up were included. The implant investigated features an asymmetrical tibial baseplate and shortened keel. Patient demographic details, Knee Society Scores (KSS), component alignment, and the presence of radiolucent lines at final follow-up were recorded. Kaplan-Meier analyses were performed to estimate survivorship.Aims
Methods
Cementless total knee arthroplasty (TKA) offers the potential for strong biological fixation compared with cemented TKA where fixation is achieved by the mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs, which have used additive manufacturing (3D printing). The aim of this study was to present mid-term clinical outcomes and implant survivorship of the cementless Stryker Triathlon Tritanium TKA. This was a single institution registry review of prospectively gathered data from 341 cementless Triathlon Tritanium TKAs at four to 6.8 years follow-up. Outcomes were determined by comparing pre- and postoperative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores, and pre- and postoperative 12-item Veterans RAND/Short Form Health Survey (VR/SF-12) scores. Aseptic loosening and revision for any reason were the endpoints which were used to determine survivorship at five years.Aims
Methods
Once knee arthritis and deformity have occurred, it is currently not known how to determine a patient’s constitutional (pre-arthritic) limb alignment. The purpose of this study was to describe and validate the arithmetic hip-knee-ankle (aHKA) algorithm as a straightforward method for preoperative planning and intraoperative restoration of the constitutional limb alignment in total knee arthroplasty (TKA). A comparative cross-sectional, radiological study was undertaken of 500 normal knees and 500 arthritic knees undergoing TKA. By definition, the aHKA algorithm subtracts the lateral distal femoral angle (LDFA) from the medial proximal tibial angle (MPTA). The mechanical HKA (mHKA) of the normal group was compared to the mHKA of the arthritic group to examine the difference, specifically related to deformity in the latter. The mHKA and aHKA were then compared in the normal group to assess for differences related to joint line convergence. Lastly, the aHKA of both the normal and arthritic groups were compared to test the hypothesis that the aHKA can estimate the constitutional alignment of the limb by sharing a similar centrality and distribution with the normal population.Aims
Methods
Eight-plates are used to correct varus-valgus deformity (VVD) or limb-length discrepancy (LLD) in children and adolescents. It was reported that these implants might create a bony deformity within the knee joint by change of the roof angle (RA) after epiphysiodesis of the proximal tibia following a radiological assessment limited to anteroposterior (AP) radiographs. The aim of this study was to analyze the RA, complemented with lateral knee radiographs, with focus on the tibial slope (TS) and the degree of deformity correction. A retrospective, single-centre study was conducted. The treatment group (n = 64 knees in 44 patients) was subclassified according to the implant location in two groups: 1) medial hemiepiphysiodesis; and 2) lateral hemiepiphysiodesis. A third control group consisted of 25 untreated knees. The limb axes and RA were measured on long standing AP leg radiographs. Lateral radiographs of 40 knees were available for TS analysis. The mean age of the patients was 10.6 years (4 to 15) in the treatment group and 8.4 years (4 to 14) in the control group. Implants were removed after a mean 1.2 years (0.5 to 3).Aims
Methods
Although bone cement is the primary mode of fixation in total knee arthroplasty (TKA), cementless fixation is gaining interest as it has the potential of achieving lasting biological fixation. By 3D printing an implant, highly porous structures can be manufactured, promoting osseointegration into the implant to prevent aseptic loosening. This study compares the migration of cementless, 3D-printed TKA to cemented TKA of a similar design up to two years of follow-up using radiostereometric analysis (RSA) known for its ability to predict aseptic loosening. A total of 72 patients were randomized to either cementless 3D-printed or a cemented cruciate retaining TKA. RSA and clinical scores were evaluated at baseline and postoperatively at three, 12, and 24 months. A mixed model was used to analyze the repeated measurements.Aims
Methods
Though the pathogenesis of Legg-Calve-Perthes disease (LCPD) is unknown, repetitive microtrauma resulting in deformity has been postulated. The purpose of this study is to trial a novel upright MRI scanner, to determine whether any deformation occurs in femoral heads affected by LCPD with weightbearing. Children affected by LCPD were recruited for analysis. Children received both standing weightbearing and supine scans in the MROpen upright MRI scanner, for coronal T1 GFE sequences, both hips in field of view. Parameters of femoral head height, width, and lateral extrusion of affected and unaffected hips were assessed by two independent raters, repeated at a one month interval. Inter- and intraclass correlation coefficients were determined. Standing and supine measurements were compared for each femoral head.Aims
Methods
An algorithm to determine the constitutional alignment of the lower limb once arthritic deformity has occurred would be of value when undertaking kinematically aligned total knee arthroplasty (TKA). The purpose of this study was to determine if the arithmetic hip-knee-ankle angle (aHKA) algorithm could estimate the constitutional alignment of the lower limb following development of significant arthritis. A matched-pairs radiological study was undertaken comparing the aHKA of an osteoarthritic knee (aHKA-OA) with the mechanical HKA of the contralateral normal knee (mHKA-N). Patients with Grade 3 or 4 Kellgren-Lawrence tibiofemoral osteoarthritis in an arthritic knee undergoing TKA and Grade 0 or 1 osteoarthritis in the contralateral normal knee were included. The aHKA algorithm subtracts the lateral distal femoral angle (LDFA) from the medial proximal tibial angle (MPTA) measured on standing long leg radiographs. The primary outcome was the mean of the paired differences in the aHKA-OA and mHKA-N. Secondary outcomes included comparison of sex-based differences and capacity of the aHKA to determine the constitutional alignment based on degree of deformity.Aims
Methods
A significant percentage of patients remain dissatisfied after total knee arthroplasty (TKA). The aim of this study was to determine whether the sequential addition of accelerometer-based navigation for femoral component preparation and sensor-guided ligament balancing improved complication rates, radiological alignment, or patient-reported outcomes (PROMs) compared with a historical control group using conventional instrumentation. This retrospective cohort study included 371 TKAs performed by a single surgeon sequentially. A historical control group, with the use of intramedullary guides for distal femoral resection and surgeon-guided ligament balancing, was compared with a group using accelerometer-based navigation for distal femoral resection and surgeon-guided balancing (group 1), and one using navigated femoral resection and sensor-guided balancing (group 2). Primary outcome measures were Patient-Reported Outcomes Measurement Information System (PROMIS) and Knee injury and Osteoarthritis Outcome (KOOS) scores measured preoperatively and at six weeks and 12 months postoperatively. The position of the components and the mechanical axis of the limb were measured postoperatively. The postoperative range of motion (ROM), haematocrit change, and complications were also recorded.Aims
Methods
It has been hypothesized that a unicompartmental knee arthroplasty (UKA) is more likely to be revised than a total knee arthroplasty (TKA) because conversion surgery to a primary TKA is a less complicated procedure. The purpose of this study was to determine if there is a lower threshold for revising a UKA compared with TKA based on Oxford Knee Scores (OKSs) and range of movement (ROM) at the time of revision. We retrospectively reviewed 619 aseptic revision cases performed between December 1998 and October 2018. This included 138 UKAs that underwent conversion to TKA and 481 initial TKA revisions. Age, body mass index (BMI), time in situ, OKS, and ROM were available for all patients.Aims
Methods
Enhanced perioperative protocols have significantly improved patient recovery following primary total knee arthroplasty (TKA). Little has been investigated the effectiveness of these protocols for revision TKA (RTKA). We report on a matched group of aseptic revision and primary TKA patients treated with an identical pain and rehabilitation programmes. Overall, 40 aseptic full-component RTKA patients were matched (surgical date, age, sex, and body mass index (BMI)) to a group of primary cemented TKA patients. All RTKAs had new uncemented stemmed femoral and tibial components with metaphyseal sleeves. Both groups were treated with an identical postoperative pain protocol. Patients were followed for at least two years. Knee Society Scores (KSS) at six weeks and at final follow-up were recorded for both groups.Aims
Methods
We report the natural course of Baker’s cysts following total knee arthroplasty (TKA) at short- and mid-term follow-up. In this prospective case series, 105 TKA patients were included. All patients who received surgery had a diagnosis of primary osteoarthritis and had preoperatively presented with a Baker’s cyst. Sonography and MRI were performed to evaluate the existence and the gross size of the cyst before TKA, and sonography was repeated at a mean follow-up time of 1.0 years (0.8 to 1.3; short-term) and 4.9 years (4.0 to 5.6; mid-term) after TKA. Symptoms potentially attributable to the Baker’s cyst were recorded at each assessment.Aims
Methods
The Precice intramedullary limb-lengthening system has demonstrated significant benefits over external fixation lengthening methods, leading to a paradigm shift in limb lengthening. This study compares outcomes following antegrade and retrograde femoral lengthening in both adolescent and adult patients. A retrospective review of prospectively collected data was undertaken of a consecutive series of 107 femoral lengthening operations in 92 patients. In total, 73 antegrade nails and 34 retrograde nails were inserted. Outcome was assessed by the regenerate healing index (HI), hip and knee range of movement (ROM), and the presence of any complications.Aims
Patients and Methods
Our intention was to investigate if the highly porous biological fixation surfaces of a new 3D-printed total knee arthroplasty (TKA) achieved adequate fixation of the tibial and patellar components to the underlying bone. A total of 29 patients undergoing primary TKA consented to participate in this prospective cohort study. All patients received a highly porous tibial baseplate and metal-backed patella. Patient-reported outcomes measures were recorded and implant migration was assessed using radiostereometric analysis.Aims
Patients and Methods
The use of vitamin E-infused highly crosslinked polyethylene (HXLPE) in total knee prostheses is controversial. In this paper we have compared the clinical and radiological results between conventional polyethylene and vitamin E-infused HXLPE inserts in total knee arthroplasty (TKA). The study included 200 knees (175 patients) that underwent TKA using the same total knee prostheses. In all, 100 knees (77 patients) had a vitamin E-infused HXLPE insert (study group) and 100 knees (98 patients) had a conventional polyethylene insert (control group). There were no significant differences in age, sex, diagnosis, preoperative knee range of movement (ROM), and preoperative Knee Society Score (KSS) between the two groups. Clinical and radiological results were evaluated at two years postoperatively.Aims
Patients and Methods
It has been hypothesized that patellofemoral pain, a common knee condition in adolescents and young adults, may be a precursor of degenerative joint changes and may ultimately lead to patellofemoral osteoarthritis. Since both conditions share several mechanical disease characteristics, such as altered contact area between the femur and patella and increased joint stress, we investigated whether these conditions share similar and different shape characteristics of the patella compared with normal controls. This cross-sectional study compared three different study populations: 32 patellofemoral pain subjects (mean age, 32 years (22 to 45); 72% female); 56 isolated radiological patellofemoral osteoarthritis subjects (mean age, 54 years (44 to 58); 89% female); and 80 healthy control subjects (mean age, 52 years (44 to 58); 74% female). Measurements included questionnaires, and lateral and skyline radiographs of the knee. Two separate 30-point 2D statistical shape models of the patella were created from the lateral and skyline radiographs. A general linear model was used to test for differences in standardized shape modes (a specific shape variant of the patella) between patellofemoral osteoarthritis, patellofemoral pain, and controls, using Bonferroni correction and adjustment for body mass index and gender.Objectives
Methods
Guided growth using eight-plates is commonly used for correction
of angular limb deformities in growing children. The principle is
of tethering at the physeal periphery while enabling growth in the
rest of the physis. The method is also applied for epiphysiodesis
to correct limb-length discrepancy (LLD). Concerns have been raised
regarding the potential of this method to create an epiphyseal deformity.
However, this has not been investigated. The purpose of this study
was to detect and quantify the occurrence of deformities in the
proximal tibial epiphysis following treatment with eight-plates. A retrospective study was performed including 42 children at
a mean age of 10.8 years (3.7 to 15.7) undergoing eight-plate insertion
in the proximal tibia for correction of coronal plane deformities
or LLD between 2007 and 2015. A total of 64 plates were inserted;
48 plates (34 patients) were inserted to correct angular deformities
and 16 plates (8 patients) for LLD. Medical records, Picture Archive
and Communication System images, and conventional radiographs were
reviewed. Measurements included interscrew angle, lateral and medial
plateau slope angles measured between the plateau surface and the
line between the ends of the physis, and tibial plateau roof angle defined
as 180° minus the sum of both plateau angles. Measurements were
compared between radiographs performed adjacent to surgery and those
at latest follow-up, and between operated and non-operated plateaus. Statistical
analysis was performed using BMDP Statistical Software.Aims
Patients and Methods
The aim of this study was to evaluate the effects of using a
portable, accelerometer-based surgical navigation system (KneeAlign2)
in total knee arthroplasty (TKA) on the alignment of the femoral
component, and blood loss. A total of 241 consecutive patients with primary osteoarthritis
of the knee were enrolled in this prospective, randomised controlled
study. There were 207 women and 34 men. The mean age of the patients
was 74.0 years (57 to 89). The KneeAlign2 system was used for distal
femoral resection in 121 patients (KA2 group) and a conventional intramedullary
femoral guide was used in 120 patients (IM group).Aims
Patients and Methods
Sustained intra-articular delivery of pharmacological agents is an attractive modality but requires use of a safe carrier that would not induce cartilage damage or fibrosis. Collagen scaffolds are widely available and could be used intra-articularly, but no investigation has looked at the safety of collagen scaffolds within synovial joints. The aim of this study was to determine the safety of collagen scaffold implantation in a validated A total of 96 rabbits were randomly and equally assigned to four different groups: arthrotomy alone; arthrotomy and collagen scaffold placement; contracture surgery; and contracture surgery and collagen scaffold placement. Animals were killed in equal numbers at 72 hours, two weeks, eight weeks, and 24 weeks. Joint contracture was measured, and cartilage and synovial samples underwent histological analysis.Objectives
Materials and Methods
Since redesign of the Oxford phase III mobile-bearing unicompartmental
knee arthroplasty (UKA) femoral component to a twin-peg design,
there has not been a direct comparison to total knee arthroplasty
(TKA). Thus, we explored differences between the two cohorts. A total of 168 patients (201 knees) underwent medial UKA with
the Oxford Partial Knee Twin-Peg. These patients were compared with
a randomly selected group of 177 patients (189 knees) with primary
Vanguard TKA. Patient demographics, Knee Society (KS) scores and
range of movement (ROM) were compared between the two cohorts. Additionally,
revision, re-operation and manipulation under anaesthesia rates
were analysed.Aims
Patients and Methods
We conducted a randomised controlled trial to assess the accuracy
of positioning and alignment of the components in total knee arthroplasty
(TKA), comparing those undertaken using standard intramedullary
cutting jigs and those with patient-specific instruments (PSI). There were 64 TKAs in the standard group and 69 in the PSI group. The post-operative hip-knee-ankle (HKA) angle and positioning
was investigated using CT scans. Deviation of >
3° from the planned
position was regarded as an outlier. The operating time, Oxford
Knee Scores (OKS) and Short Form-12 (SF-12) scores were recorded.Aims
Patients and Methods
As the number of younger and more active patients
treated with total knee arthroplasty (TKA) continues to increase,
consideration of better fixation as a means of improving implant
longevity is required. Cemented TKA remains the reference standard
with the largest body of evidence and the longest follow-up to support
its use. However, cementless TKA, may offer the opportunity of a
more bone-sparing procedure with long lasting biological fixation
to the bone. We undertook a review of the literature examining advances
of cementless TKA and the reported results. Cite this article:
In arthritis of the varus knee, a high tibial
osteotomy (HTO) redistributes load from the diseased medial compartment
to the unaffected lateral compartment. We report the outcome of 36 patients (33 men and three women)
with 42 varus, arthritic knees who underwent HTO and dynamic correction
using a Garches external fixator until they felt that normal alignment
had been restored. The mean age of the patients was 54.11 years
(34 to 68). Normal alignment was achieved at a mean 5.5 weeks (3
to 10) post-operatively. Radiographs, gait analysis and visual analogue
scores for pain were measured pre- and post-operatively, at one
year and at medium-term follow-up (mean six years; 2 to 10). Failure
was defined as conversion to knee arthroplasty. Pre-operative gait analysis divided the 42 knees into two equal
groups with high (17 patients) or low (19 patients) adductor moments.
After correction, a statistically significant (p <
0.001, At final follow-up, after a mean of 15.9 years (12 to 20), there
was a survivorship of 59% (95% CI 59.6 to 68.9) irrespective of
adductor moment group, with a mean time to conversion to knee arthroplasty
of 9.5 years (3 to 18; 95% confidence interval ± 2.5). HTO remains a useful option in the medium-term for the treatment
of medial compartment osteoarthritis of the knee but does not last
in the long-term. Cite this article:
Nail patella syndrome (NPS) is a skeletal dysplasia with patellofemoral
dysfunction as a key symptom. We present the first in-depth radiological
evaluation of the knee in a large series of NPS patients and describe
the typical malformations. Conventional radiological examination of 95 skeletally mature
patients with NPS was performed. Patellar morphology was classified
according to the Wiberg classification as modified by Baumgartl
and Ficat criteria, and trochlear shape was classified according
to the Dejour classification.Aim
Patients and Methods
Pelvic obliquity is a common finding in adolescents
with cerebral palsy, however, there is little agreement on its measurement
or relationship with hip development at different gross motor function
classification system (GMFCS) levels. The purpose of this investigation was to study these issues in
a large, population-based cohort of adolescents with cerebral palsy
at transition into adult services. The cohort were a subset of a three year birth cohort (n = 98,
65M: 33F, with a mean age of 18.8 years (14.8 to 23.63) at their
last radiological review) with the common features of a migration
percentage greater than 30% and a history of adductor release surgery. Different radiological methods of measuring pelvic obliquity
were investigated in 40 patients and the angle between the acetabular
tear drops (ITDL) and the horizontal reference frame of the radiograph
was found to be reliable, with good face validity. This was selected
for further study in all 98 patients. The median pelvic obliquity was 4° (interquartile range 2° to
8°). There was a strong correlation between hip morphology and the
presence of pelvic obliquity (effect of ITDL on Sharpe’s angle in
the higher hip; rho 7.20 (5% confidence interval 5.59 to 8.81, p
<
0.001). This was particularly true in non-ambulant adolescents
(GMFCS IV and V) with severe pelvic obliquity, but was also easily
detectable and clinically relevant in ambulant adolescents with mild
pelvic obliquity. The identification of pelvic obliquity and its management deserves
closer scrutiny in children and adolescents with cerebral palsy. Cite this article:
In 11 paediatric patients (seven girls and four
boys, from 12 to 15 years old) with unilateral obligatory patellar dislocation
and ligamentous laxity vastus medialis advancement, lateral release,
partial patellar ligament transposition and Galeazzi semitendinosus
tenodesis was undertaken to stabilise the patella. The diagnostic criterion
for ligamentous laxity was based on the Beighton scale. Outcomes
were evaluated radiologically and functionally by measurement of
the range of knee movement and isokinetic testing. The evaluation
also included the Lysholm knee scale. Follow-up studies took place
at a mean of 8.1 years (5 to 15) post-operatively. Normal patellar tracking without any recurrence of dislocation
was obtained in ten out of 11 patients. Pain related to vigorous
activity was reported by nine patients. Compared with the opposite
normal side, the isokinetic tests revealed a statistically significant
decrease in the maximal torque values for the affected quadriceps
muscle (p = 0.003 and p = 0.004), but no difference between the
knee flexors (for angular velocities of 60°/s and 180°/s) (p = 0.858
and p = 0.79). The applied surgical technique generally prevents the recurrence
of the disorder in children with habitual patellar dislocation and
ligamentous laxity. Quadriceps muscle weakness can be expected to
occur post-operatively, Cite this article:
A retrospective review was performed of patients
undergoing primary cementless total knee replacement (TKR) using
porous tantalum performed by a group of surgical trainees. Clinical
and radiological follow-up involved 79 females and 26 males encompassing
115 knees. The mean age was 66.9 years (36 to 85). Mean follow-up
was 7 years (2 to 11). Tibial and patellar components were porous
tantalum monoblock implants, and femoral components were posterior
stabilised (PS) in design with cobalt–chromium fibre mesh. Radiological
assessments were made for implant positioning, alignment, radiolucencies,
lysis, and loosening. There was 95.7% survival of implants. There
was no radiological evidence of loosening and no osteolysis found.
No revisions were performed for aseptic loosening. Average tibial
component alignment was 1.4° of varus (4°of valgus to 9° varus),
and 6.2° (3° anterior to 15° posterior) of posterior slope. Mean
femoral component alignment was 6.6° (1° to 11°) of valgus. Mean tibiofemoral
alignment was 5.6° of valgus (7° varus to 16° valgus). Patellar
tilt was a mean of 2.4° lateral (5° medial to 28° lateral). Patient
satisfaction with improvement in pain was 91%. Cementless TKR incorporating
porous tantalum yielded good clinical and radiological outcomes
at a mean of follow-up of seven-years. Cite this article:
The cam-type deformity in femoroacetabular impingement
is a 3D deformity. Single measurements using radiographs, CT or
MRI may not provide a true estimate of the magnitude of the deformity.
We performed an analysis of the size and location of measurements
of the alpha angle (α°) using a CT technique which could be applied
to the 3D reconstructions of the hip. Analysis was undertaken in
42 patients (57 hips; 24 men and 18 women; mean age 38 years (16
to 58)) who had symptoms of femoroacetabular impingement related
to a cam-type abnormality. An α° of >
50° was considered a significant
indicator of cam-type impingement. Measurements of the α° were made
at different points around the femoral head/neck junction at intervals
of 30°: starting at the nine o’clock (posterior), ten, eleven and
twelve o’clock (superior), one, two and ending at three o’clock
(anterior) position. The mean maximum increased α° was 64.6° (50.8° to 86°). The two
o’clock position was the most common point to find an increased α°
(53 hips; 93%), followed by one o’clock (48 hips; 84%). The largest α°
for each hip was found most frequently at the two o’clock position
(46%), followed by the one o’clock position (39%). Generally, raised α angles
extend over three segments of the clock face. Single measurements of the α°, whether pre- or post-operative,
should be viewed with caution as they may not be representative
of the true size of the deformity and not define whether adequate
correction has been achieved following surgery. Cite this article:
Damage to the cartilage of the distal radioulnar
joint frequently leads to pain and limitation of movement, therefore repair
of this joint cartilage would be highly desirable. The purpose of
this study was to investigate the fixation of scaffold in cartilage
defects of this joint as part of matrix-assisted regenerative autologous
cartilage techniques. Two techniques of fixation of collagen scaffolds,
one involving fibrin glue alone and one with fibrin glue and sutures, were
compared in artificially created cartilage defects of the distal
radioulnar joint in a human cadaver. After being subjected to continuous
passive rotation, the methods of fixation were evaluated for cover
of the defect and pull out force. No statistically significant differences were found between the
two techniques for either cover of the defect or integrity of the
scaffold. However, a significantly increased mean pull out force
was found for the combined procedure, 0.665 N (0.150 to 1.160) This suggests that although successful fixation of a collagen
type I/III scaffold in a distal radioulnar joint cartilage defect
is feasible with both forms of fixation, fixation with glue and
sutures is preferable. Cite this article:
The management of failed autologous chondrocyte
implantation (ACI) and matrix-assisted autologous chondrocyte implantation
(MACI) for the treatment of symptomatic osteochondral defects in
the knee represents a major challenge. Patients are young, active
and usually unsuitable for prosthetic replacement. This study reports
the results in patients who underwent revision cartilage transplantation
of their original ACI/MACI graft for clinical or graft-related failure.
We assessed 22 patients (12 men and 10 women) with a mean age of
37.4 years (18 to 48) at a mean of 5.4 years (1.3 to 10.9). The
mean period between primary and revision grafting was 46.1 months
(7 to 89). The mean defect size was 446.6 mm. 2. (150 to
875) and they were located on 11 medial and two lateral femoral condyles,
eight
Structural allografts may be used to manage uncontained
bone defects in revision total knee replacement (TKR). However,
the availability of cadaver grafts is limited in some areas of Asia.
The aim of this study was to evaluate the mid-term outcome of the
use of femoral head allografts for the reconstruction of uncontained
defects in revision TKR, focusing on complications related to the
graft. We retrospectively reviewed 28 patients (30 TKRs) with Anderson
Orthopaedic Research Institute (AORI) type 3 bone defects, who underwent
revision using femoral head allografts and stemmed components. The
mean number of femoral heads used was 1.7 (1 to 3). The allograft–host
junctions were packed with cancellous autograft. At a mean follow-up of 76 months (38 to 136) the mean American
Knee Society knee score improved from 37.2 (17 to 60) pre-operatively
to 90 (83 to 100) (p <
0.001). The mean function score improved
from 26.5 (0 to 50) pre-operatively to 81 (60 to 100) (p <
0.001).
All the grafts healed to the host bone. The mean time to healing
of the graft was 6.6 months
(4 to 16). There have been no complications of collapse of the graft,
nonunion, infection or implant loosening. No revision surgery was
required. The use of femoral head allografts in conjunction with a stemmed
component and autogenous bone graft in revision TKR in patients
with uncontained bone defects resulted in a high rate of healing
of the graft with minimal complications and a satisfactory outcome.
Longer follow-up is needed to observe the evolution of the graft. Cite this article:
Matrix-assisted autologous chondrocyte transplantation (MACT)
has been developed and applied in the clinical practice in the last
decade to overcome most of the disadvantages of the first generation
procedures. The purpose of this systematic review is to document
and analyse the available literature on the results of MACT in the
treatment of chondral and osteochondral lesions of the knee. All studies published in English addressing MACT procedures were
identified, including those that fulfilled the following criteria:
1) level I-IV evidence, 2) measures of functional or clinical outcome,
3) outcome related to cartilage lesions of the knee cartilage.Objectives
Methods
Deformity after slipped upper femoral epiphysis
(SUFE) can cause cam-type femoroacetabular impingement (FAI) and
subsequent osteoarthritis (OA). However, there is little information
regarding the radiological assessment and clinical consequences
at long-term follow-up. We reviewed 36 patients (43 hips) previously
treated by We conclude that persistent deformity with radiological cam FAI
after SUFE is associated with poorer clinical and radiological long-term
outcome. Although the radiological measurements had quite wide limits
of agreement, they are useful for the diagnosis of post-slip deformities
in clinical practice.
Disruption of the extensor mechanism in total
knee arthroplasty may occur by tubercle avulsion, patellar or quadriceps
tendon rupture, or patella fracture, and whether occurring intra-operatively
or post-operatively can be difficult to manage and is associated
with a significant rate of failure and associated complications.
This surgery is frequently performed in compromised tissues, and
repairs must frequently be protected with cerclage wiring and/or
augmentation with local tendon (semi-tendinosis, gracilis) which
may also be used to treat soft-tissue loss in the face of chronic
disruption. Quadriceps rupture may be treated with conservative
therapy if the patient retains active extension. Component loosening
or loss of active extension of 20° or greater are clear indications
for surgical treatment of patellar fracture. Acute patellar tendon
disruption may be treated by primary repair. Chronic extensor failure
is often complicated by tissue loss and retraction can be treated
with medial gastrocnemius flaps, achilles tendon allografts, and
complete extensor mechanism allografts. Attention to fixing the
graft in full extension is mandatory to prevent severe extensor
lag as the graft stretches out over time.
Seven stiff total knee arthroplasties are presented
to illustrate the roles of: 1) manipulation under general anesthesia;
2) multiple concurrent diagnoses in addition to stiffness; 3) extra-articular
pathology; 4) pain as part of the stiffness triad (pain and limits
to flexion or extension); 5) component internal rotation; 6) multifactorial
etiology; and 7) surgical exposure in this challenging clinical
problem.
Numerous complications following total knee replacement (TKR)
relate to the patellofemoral (PF) joint, including pain and patellar
maltracking, yet the options for A total of three knees with end-stage osteoarthritis and three
knees that had undergone TKR at more than one year’s follow-up were
investigated. In each knee, sequential biplane radiological images
were acquired from the sagittal direction (i.e. horizontal X-ray
source and 10° below horizontal) for a sequence of eight flexion
angles. Three-dimensional implant or bone models were matched to
the biplane images to compute the six degrees of freedom of PF tracking
and TF kinematics, and other clinical measures.Objectives
Methods
