Aims. The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery. Methods. A total of 454 consecutive patients who underwent cementless TKA between August 2004 and December 2021 were reviewed. The mean follow-up was ten years.
Aims. The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups. Methods. This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma.
Objectives. An important measure for the diagnosis and monitoring of knee osteoarthritis is the minimum joint space width (mJSW). This requires accurate alignment of the x-ray beam with the tibial plateau, which may not be accomplished in practice. We investigate the feasibility of a new mJSW measurement method from stereo radiographs using 3D statistical shape models (SSM) and evaluate its sensitivity to changes in the mJSW and its robustness to variations in patient positioning and bone geometry. Materials and Methods. A validation study was performed using five cadaver specimens. The actual mJSW was varied and images were acquired with variation in the cadaver positioning. For comparison purposes, the mJSW was also assessed from
We studied whether the presence of lateral osteophytes
on
We studied the intra- and interobserver reliability of measurements of the position of the components after total knee replacement (TKR) using a combination of radiographs and axial two-dimensional (2D) and three-dimensional (3D) reconstructed CT images to identify which method is best for this purpose. A total of 30 knees after primary TKR were assessed by two independent observers (an orthopaedic surgeon and a radiologist) using radiographs and CT scans.
We used single-photon emission computed tomography (SPECT) to determine the long-term risk of degenerative change after reconstruction of the anterior cruciate ligament (ACL). Our study population was a prospective series of 31 patients with a mean age at injury of 27.8 years (18 to 47) and a mean follow-up of ten years (9 to 13) after bone-patellar tendon-bone reconstruction of the ACL. The contralateral normal knee was used as a control. All knees were clinically stable with high clinical scores (mean Lysholm score, 93; mean Tegner activity score, 6). Fifteen patients had undergone a partial meniscectomy and ACL reconstruction at or before reconstruction of their ACL. In the group with an intact meniscus, clinical symptoms of osteoarthritis (OA) were found in only one patient (7%), who was also the only patient with marked isotope uptake on the SPECT scan compatible with OA. In the group which underwent a partial meniscectomy, clinical symptoms of OA were found in two patients (13%), who were among five (31%) with isotope uptake compatible with OA. Only one patient (7%) in this group had evidence of advanced OA on
We prospectively examined the physical and imaging findings, including MRI, of 23 patients with spontaneous osteonecrosis of the knee after obtaining informed consent to acquire tissue specimens at surgery. There were four men and 19 women, with a mean age of 67.5 years (58 to 77).
We report a patient with a subperiosteal ganglion cyst of the tibia which was imaged by radiography, arthrography, CT and MRI. The images were correlated with the arthroscopic surgical and histological findings. Spiculated formation of periosteal new bone on
The Fulkerson osteotomy has proved to be a reliable treatment for subluxation of the patella due to malalignment. Aggressive rehabilitation in the early postoperative period is unwise since the proximal tibia is weakened by the oblique osteotomy. Early weight-bearing and unrestricted activity have caused fractures in a few patients. Even late in the postoperative period the osteotomy may adversely influence the biomechanical properties of the proximal tibia. We describe two athletes who sustained a fracture of the proximal tibia, during recreational activities, six months after a Fulkerson osteotomy. Both had been bearing full weight for about ten weeks without complaint. Bony healing of the osteotomy had been demonstrated on
This study aims to determine the rate of and risk factors for total knee arthroplasty (TKA) after operative management of tibial plateau fractures (TPFs) in older adults. This is a retrospective cohort study of 182 displaced TPFs in 180 patients aged ≥ 60 years, over a 12-year period with a minimum follow-up of one year. The mean age was 70.7 years (SD 7.7; 60 to 89), and 139/180 patients (77.2%) were female. Radiological assessment consisted of fracture classification; pre-existing knee osteoarthritis (OA); reduction quality; loss of reduction; and post-traumatic OA. Fracture depression was measured on CT, and the volume of defect estimated as half an oblate spheroid. Operative management, complications, reoperations, and mortality were recorded.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
The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous.Aims
Methods
To evaluate whether low-intensity pulsed ultrasound (LIPUS) accelerates bone healing at osteotomy sites and promotes functional recovery after open-wedge high tibial osteotomy (OWHTO). Overall, 90 patients who underwent OWHTO without bone grafting were enrolled in this nonrandomized retrospective study, and 45 patients treated with LIPUS were compared with 45 patients without LIPUS treatment in terms of bone healing and functional recovery postoperatively. Clinical evaluations, including the pain visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score, were performed preoperatively as well as six weeks and three, six, and 12 months postoperatively. The progression rate of gap filling was evaluated using anteroposterior radiographs at six weeks and three, six, and 12 months postoperatively.Aims
Methods
Obtaining solid implant fixation is crucial in revision total knee arthroplasty (rTKA) to avoid aseptic loosening, a major reason for re-revision. This study aims to validate a novel grading system that quantifies implant fixation across three anatomical zones (epiphysis, metaphysis, diaphysis). Based on pre-, intra-, and postoperative assessments, the novel grading system allocates a quantitative score (0, 0.5, or 1 point) for the quality of fixation achieved in each anatomical zone. The criteria used by the algorithm to assign the score include the bone quality, the size of the bone defect, and the type of fixation used. A consecutive cohort of 245 patients undergoing rTKA from 2012 to 2018 were evaluated using the current novel scoring system and followed prospectively. In addition, 100 first-time revision cases were assessed radiologically from the original cohort and graded by three observers to evaluate the intra- and inter-rater reliability of the novel radiological grading system.Aims
Methods
The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources. Day-case TKAs, defined as patients discharged on the same calendar day as surgery, were retrospectively reviewed with a minimum follow-up of six months. Analysis of hospital and primary care records was performed to determine readmission and reattendance rates. Telephone interviews were conducted to determine patient satisfaction.Aims
Methods
The purpose of this study was to assess mid-term survivorship following primary total knee arthroplasty (TKA) with Optetrak Logic components and identify the most common revision indications at a single institution. We identified a retrospective cohort of 7,941 Optetrak primary TKAs performed from January 2010 to December 2018. We reviewed the intraoperative findings of 369 TKAs that required revision TKA from January 2010 to December 2021 and the details of the revision implants used. Kaplan-Meier analysis was used to determine survivorship. Cox regression analysis was used to examine the impact of patient variables and year of implantation on survival time.Aims
Methods
Accurate identification of the ankle joint centre is critical for estimating tibial coronal alignment in total knee arthroplasty (TKA). The purpose of the current study was to leverage artificial intelligence (AI) to determine the accuracy and effect of using different radiological anatomical landmarks to quantify mechanical alignment in relation to a traditionally defined radiological ankle centre. Patients with full-limb radiographs from the Osteoarthritis Initiative were included. A sub-cohort of 250 radiographs were annotated for landmarks relevant to knee alignment and used to train a deep learning (U-Net) workflow for angle calculation on the entire database. The radiological ankle centre was defined as the midpoint of the superior talus edge/tibial plafond. Knee alignment (hip-knee-ankle angle) was compared against 1) midpoint of the most prominent malleoli points, 2) midpoint of the soft-tissue overlying malleoli, and 3) midpoint of the soft-tissue sulcus above the malleoli.Aims
Methods
A fracture of the medial tibial plateau is a serious complication of Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). The risk of these fractures is reportedly lower when using components with a longer keel-cortex distance (KCDs). The aim of this study was to examine how slight varus placement of the tibial component might affect the KCDs, and the rate of tibial plateau fracture, in a clinical setting. This retrospective study included 255 patients who underwent 305 OUKAs with cementless tibial components. There were 52 males and 203 females. Their mean age was 73.1 years (47 to 91), and the mean follow-up was 1.9 years (1.0 to 2.0). In 217 knees in 187 patients in the conventional group, tibial cuts were made orthogonally to the tibial axis. The varus group included 88 knees in 68 patients, and tibial cuts were made slightly varus using a new osteotomy guide. Anterior and posterior KCDs and the origins of fracture lines were assessed using 3D CT scans one week postoperatively. The KCDs and rate of fracture were compared between the two groups.Aims
Methods
Loosening of components after total knee arthroplasty (TKA) can be associated with the development of radiolucent lines (RLLs). The aim of this study was to assess the rate of formation of RLLs in the cemented original design of the ATTUNE TKA and their relationship to loosening. A systematic search was undertaken using the Cochrane methodology in three online databases: MEDLINE, Embase, and CINAHL. Studies were screened against predetermined criteria, and data were extracted. Available National Joint Registries in the Network of Orthopaedic Registries of Europe were also screened. A random effects model meta-analysis was undertaken.Aims
Methods
This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS). Patients scheduled for primary TKA were included in a single-centre, prospective, three-armed, blinded randomized trial (n = 216; 72 per group). After intraoperative confirmation of posterior cruciate ligament (PCL) integrity, patients were randomly allocated to receive a CR, AS, or PS design from the same TKA system. Insertion of an AS or PS design required PCL resection. The primary outcome was the mean score of all five subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS) at two-year follow-up. Secondary outcomes included all KOOS subscales, Oxford Knee Score, EuroQol five-dimension health questionnaire, EuroQol visual analogue scale, range of motion (ROM), and willingness to undergo the operation again. Patient satisfaction was also assessed.Aims
Methods
Total knee arthroplasty (TKA) is a common and safe orthopaedic procedure. Zimmer Biomet's NexGen is the second most popular brand of implant used in the UK. The primary cause of revision after the first year is aseptic loosening. We present our experience of using this implant, with significant concerns around its performance with regards early aseptic loosening of the tibial component. A retrospective, single-surgeon review was carried out of all of the NexGen Legacy Posterior Stabilized (LPS) TKAs performed in this institute. The specific model used for the index procedures was the NexGen Complete Knee System (Legacy Knee-Posterior Stabilized LPS-Flex Articular Surface, LPS-Flex Femoral Component Option, and Stemmed Nonaugmentable Tibial Component Option).Aims
Methods
The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective. The OBC and the patellotrochlear index were used as part of the Oswestry Patellotrochlear Algorithm (OPTA) to guide the surgical treatment of patients with patellar instability. Patients were assigned to one of four treatment groups: medial patellofemoral ligament reconstruction (MPFLr); MPFLr + tibial tubercle distalization (TTD); trochleoplasty; or trochleoplasty + TTD. A prospective analysis of a longitudinal patellofemoral database was performed. Between 2012 and 2018, 202 patients (233 knees) with a mean age of 24.2 years (SD 8.1), with recurrent patellar instability were treated by two fellowship-trained consultant sports/knee surgeons at The Robert Jones and Agnes Hunt Orthopaedic Hospital. Clinical efficacy of each treatment group was assessed by Kujala, International Knee Documentation Committee (IKDC), and EuroQol five-dimension questionnaire (EQ-5D) scores at baseline, and up to 60 months postoperatively. Their safety was assessed by complication rate and requirement for further surgery. The pattern of clinical outcome over time was analyzed using mixed regression modelling.Aims
Methods
Our purpose was to describe an unusual series of 21 patients with fungal osteomyelitis after an anterior cruciate ligament reconstruction (ACL-R). We present a case-series of consecutive patients treated at our institution due to a severe fungal osteomyelitis after an arthroscopic ACL-R from November 2005 to March 2015. Patients were referred to our institution from different areas of our country. We evaluated the amount of bone resection required, type of final reconstructive procedure performed, and Musculoskeletal Tumor Society (MSTS) functional score.Aims
Methods
Limb alignment in total knee arthroplasty (TKA) influences periarticular soft-tissue tension, biomechanics through knee flexion, and implant survival. Despite this, there is no uniform consensus on the optimal alignment technique for TKA. Neutral mechanical alignment facilitates knee flexion and symmetrical component wear but forces the limb into an unnatural position that alters native knee kinematics through the arc of knee flexion. Kinematic alignment aims to restore native limb alignment, but the safe ranges with this technique remain uncertain and the effects of this alignment technique on component survivorship remain unknown. Anatomical alignment aims to restore predisease limb alignment and knee geometry, but existing studies using this technique are based on cadaveric specimens or clinical trials with limited follow-up times. Functional alignment aims to restore the native plane and obliquity of the joint by manipulating implant positioning while limiting soft tissue releases, but the results of high-quality studies with long-term outcomes are still awaited. The drawbacks of existing studies on alignment include the use of surgical techniques with limited accuracy and reproducibility of achieving the planned alignment, poor correlation of intraoperative data to long-term functional outcomes and implant survivorship, and a paucity of studies on the safe ranges of limb alignment. Further studies on alignment in TKA should use surgical adjuncts (e.g. robotic technology) to help execute the planned alignment with improved accuracy, include intraoperative assessments of knee biomechanics and periarticular soft-tissue tension, and correlate alignment to long-term functional outcomes and survivorship.
Patients with a deformity of the hindfoot present a particular challenge when performing total knee arthroplasty (TKA). The literature contains little information about the relationship between TKA and hindfoot alignment. This systematic review aimed to determine from both clinical and radiological studies whether TKA would alter a preoperative hindfoot deformity and whether the outcome of TKA is affected by the presence of a postoperative hindfoot deformity. A systematic literature search was performed in the databases PubMed, EMBASE, Cochrane Library, and Web of Science. Search terms consisted of “total knee arthroplasty/replacement” combined with “hindfoot/ankle alignment”. Inclusion criteria were all English language studies analyzing the association between TKA and the alignment of the hindfoot, including the clinical or radiological outcomes. Exclusion criteria consisted of TKA performed with a concomitant extra-articular osteotomy and case reports or expert opinions. An assessment of quality was conducted using the modified Methodological Index for Non-Randomized Studies (MINORS). The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the PROSPERO database (CRD42019106980).Aims
Methods
Medial pivot (MP) total knee arthroplasties (TKAs) were designed to mimic native knee kinematics with their deep medial congruent fitting of the tibia to the femur almost like a ball-on-socket, and a flat lateral part. GMK Sphere is a novel MP implant. Our primary aim was to study the migration pattern of the tibial tray of this TKA. A total of 31 patients were recruited to this single-group radiostereometric analysis (RSA) study and received a medial pivot GMK Sphere TKA. The distributions of male patients versus female patients and right versus left knees were 21:10 and 17:14, respectively. Mean BMI was 29 kg/m2 (95% confidence interval (CI) 27 to 30) and mean age at surgery was 63 years (95% CI 61 to 66). Maximum total point motions (MTPMs), medial, proximal, and anterior translations and transversal, internal, and varus rotations were calculated at three, 12, and 24 months. Patient-reported outcome measure data were also retrieved.Aims
Methods
The aim of this study was to evaluate the ability of a machine-learning algorithm to diagnose prosthetic loosening from preoperative radiographs and to investigate the inputs that might improve its performance. A group of 697 patients underwent a first-time revision of a total hip (THA) or total knee arthroplasty (TKA) at our institution between 2012 and 2018. Preoperative anteroposterior (AP) and lateral radiographs, and historical and comorbidity information were collected from their electronic records. Each patient was defined as having loose or fixed components based on the operation notes. We trained a series of convolutional neural network (CNN) models to predict a diagnosis of loosening at the time of surgery from the preoperative radiographs. We then added historical data about the patients to the best performing model to create a final model and tested it on an independent dataset.Aims
Methods
The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery. An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and axial alignment of the knee preoperatively and at three months postoperatively to determine changes in anatomy that had occurred as a result of the surgery. The hip-knee-ankle angle (HKAA) was also measured to identify any differences between the two groups.Aims
Methods
Although knee osteoarthritis (OA) is diagnosed and monitored radiologically, actual full-thickness cartilage loss (FTCL) has rarely been correlated with radiological classification. This study aims to analyze which classification system correlates best with FTCL and to assess their reliability. A prospective study of 300 consecutive patients undergoing unilateral total knee arthroplasty (TKA) for OA (mean age 69 years (44 to 91; standard deviation (SD) 9.5), 178 (59%) female). Two blinded examiners independently graded preoperative radiographs using five common systems: Kellgren-Lawrence (KL); International Knee Documentation Committee (IKDC); Fairbank; Brandt; and Ahlbäck. Interobserver agreement was assessed using the intraclass correlation coefficient (ICC). Intraoperatively, anterior cruciate ligament (ACL) status and the presence of FTCL in 16 regions of interest were recorded. Radiological classification and FTCL were correlated using the Spearman correlation coefficient.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
This study aimed to evaluate the association between the sagittal alignment of the femoral component in total knee arthroplasty (TKA) and new Knee Society Score (2011KSS), under the hypothesis that outliers such as the excessive extended or flexed femoral component were related to worse clinical outcomes. A group of 156 knees (134 F:22 M) in 133 patients with a mean age 75.8 years (SD 6.4) who underwent TKA with the cruciate-substituting Bi-Surface Knee prosthesis were retrospectively enrolled. On lateral radiographs, γ angle (the angle between the distal femoral axis and the line perpendicular to the distal rear surface of the femoral component) was measured, and the patients were divided into four groups according to the γ angle. The 2011KSSs among groups were compared using the Kruskal-Wallis test. A secondary regression analysis was used to investigate the association between the 2011KSS and γ angle.Aims
Methods
Trochlear dysplasia is a significant risk factor for patellofemoral instability. The Dejour classification is currently considered the standard for classifying trochlear dysplasia, but numerous studies have reported poor reliability on both plain radiography and MRI. The severity of trochlear dysplasia is important to establish in order to guide surgical management. We have developed an MRI-specific classification system to assess the severity of trochlear dysplasia, the Oswestry-Bristol Classification (OBC). This is a four-part classification system comprising normal, mild, moderate, and severe to represent a normal, shallow, flat, and convex trochlear, respectively. The purpose of this study was to assess the inter- and intraobserver reliability of the OBC and compare it with that of the Dejour classification. Four observers (two senior and two junior orthopaedic surgeons) independently assessed 32 CT and axial MRI scans for trochlear dysplasia and classified each according to the OBC and the Dejour classification systems. Assessments were repeated following a four-week interval. The inter- and intraobserver agreement was determined by using Fleiss’ generalization of Cohen’s kappa statistic and S-statistic nominal and linear weights.Aims
Methods
There is insufficient evidence to recommend the use of alternative polyethylene bearings in modular, fixed-bearing total knee arthroplasty (TKA). The purpose of this study was to compare standard polyethylene (SP) and highly crosslinked polyethylene (XLP) tibial liners in posterior-stabilized TKA, with osteolysis as the primary outcome and clinical results and the rate of re-operation as the secondary outcomes. This is a single-surgeon, prospective randomized study involving one design of modular posterior-stabilized TKA. An analysis of 122 TKAs with an SP compression moulded liner and 123 with an XLP liner was performed, with a mean follow-up of six years (2 to 11). Patients were evaluated clinically using the Knee Society score, Lower Extremity Activity Score (LEAS), and the presence of an effusion, and standard radiographs were assessed for radiolucent lines and osteolytic lesions.Aims
Patients and Methods
The aim of this study was to determine and compare the congruency of the articular surface contact area of the patellofemoral joint (PFJ) during both active and passive movement of the knee with the use of an MRI mapping technique in both the stable and unstable PFJ. A prospective case-control MRI imaging study of patients with a history of PFJ instability and a control group of volunteers without knee symptoms was performed. The PFJs were imaged with the use of an MRI scan during both passive and active movement from 0° through to 40° of flexion. The congruency through measurement of the contact surface area was mapped in 5-mm intervals on axial slices. In all, 40 patients were studied. The case group included 31 patients with symptomatic patellofemoral instability and the control group of nine asymptomatic volunteers. The ages were well matched between the case and control groups. The mean age was 25 years (16 to 42; Aims
Patients and Methods
Knee osteonecrosis in advanced stages may lead to joint degeneration. Total knee arthroplasty (TKA) for osteonecrosis has traditionally been associated with suboptimal results. We analyzed outcomes of contemporary TKAs for osteonecrosis, with particular emphasis on: survivorship free from aseptic loosening, any revision, and any reoperation plus the clinical outcomes, complications, and radiological results. In total, 156 patients undergoing 167 primary TKAs performed for osteonecrosis between 2004 and 2014 at a single institution were reviewed. The mean age at index TKA was 61 years (14 to 93) and the mean body mass index (BMI) was 30 kg/m2 (18 to 51) The mean follow-up was six years (2 to 12). A total of 110 TKAs (66%) were performed for primary osteonecrosis and 57 TKAs (34%) for secondary osteonecrosis. Overall, 15 TKAs (9%) had tibial stems, while 12 TKAs (7%) had femoral stems. Posterior-stabilized designs were used in 147 TKAs (88%) of TKAs. Bivariate Cox regression analysis was conducted to identify risk factors for revision and reoperation.Aims
Patients and Methods
Primary (or spontaneous) and secondary osteonecrosis of the knee
can lead to severe joint degeneration, for which either total or
unicompartmental arthroplasty may be considered. However, there
are limited studies analyzing outcomes of unicompartmental knee arthroplasties
(UKAs) for osteonecrosis involving an isolated compartment of the
knee. The aims of this study were to analyze outcomes of UKAs for
osteonecrosis with specific focus on 1) survivorship free of any
revision or reoperation, 2) risk factors for failure, 3) clinical outcomes,
and 4) complications. A total of 45 patients underwent 46 UKAs for knee osteonecrosis
between 2002 and 2014 at our institution (The Mayo Clinic, Rochester,
Minnesota). Twenty patients (44%) were female; the mean age of the
patients was 66 years, and mean body mass index (BMI) was 31 kg/m2. Of
the 46 UKAs, 44 (96%) were medial UKAs, and 35 (76%) were fixed-bearing
design. Mean mechanical axis postoperatively was 1.5° varus (0°
to 5° varus); 41 UKAs (89%) were performed for primary osteonecrosis.
Mean follow-up was five years (2 to 12)Aims
Patients and Methods
Researchers continue to seek easier ways to evaluate the quality of bone and screen for osteoporosis and osteopenia. Until recently, radiographic images of various parts of the body, except the distal femur, have been reappraised in the light of dual-energy X-ray absorptiometry (DXA) findings. The incidence of osteoporotic fractures around the knee joint in the elderly continues to increase. The aim of this study was to propose two new radiographic parameters of the distal femur for the assessment of bone quality. Anteroposterior radiographs of the knee and bone mineral density (BMD) and T-scores from DXA scans of 361 healthy patients were prospectively analyzed. The mean cortical bone thickness (CBTavg) and the distal femoral cortex index (DFCI) were the two parameters that were proposed and measured. Intra- and interobserver reliabilities were assessed. Correlations between the BMD and T-score and these parameters were investigated and their value in the diagnosis of osteoporosis and osteopenia was evaluated.Objectives
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
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
Patellar instability most frequently presents
during adolescence. Congenital and infantile dislocation of the
patella is a distinct entity from adolescent instability and measurable
abnormalities may be present at birth. In the normal patellofemoral
joint an increase in quadriceps angle and patellar height are matched
by an increase in trochlear depth as the joint matures. Adolescent
instability may herald a lifelong condition leading to chronic disability
and arthritis. Restoring normal anatomy by trochleoplasty, tibial tubercle transfer
or medial patellofemoral ligament (MPFL) reconstruction in the young
adult prevents further instability. Although these techniques are
proven in the young adult, they may cause growth arrest and deformity
where the physis is open. A vigorous non-operative strategy may
permit delay of surgery until growth is complete. Where non-operative
treatment has failed a modified MPFL reconstruction may be performed
to maintain stability until physeal closure permits anatomical reconstruction.
If significant growth remains an extraosseous reconstruction of
the MPFL may impart the lowest risk to the physis. If minor growth
remains image intensifier guided placement of femoral intraosseous
fixation may impart a small, but acceptable, risk to the physis. This paper presents and discusses the literature relating to
adolescent instability and provides a framework for management of
these patients. Cite this article:
Osteochondritis Dissecans (OCD) is a condition
for which the aetiology remains unknown. It affects subchondral bone
and secondarily its overlying cartilage and is mostly found in the
knee. It can occur in adults, but is generally identified when growth
remains, when it is referred to as juvenile OCD. As the condition
progresses, the affected subchondral bone separates from adjacent
healthy bone, and can lead to demarcation and separation of its associated
articular cartilage. Any symptoms which arise relate to the stage
of the disease. Early disease without separation of the lesion results
in pain. Separation of the lesion leads to mechanical symptoms and
swelling and, in advanced cases, the formation of loose bodies. Early identification of OCD is essential as untreated OCD can
lead to the premature degeneration of the joint, whereas appropriate
treatment can halt the disease process and lead to healing. Establishing
the stability of the lesion is a key part of providing the correct
treatment. Stable lesions, particularly in juvenile patients, have
greater propensity to heal with non-surgical treatment, whereas
unstable or displaced lesions usually require surgical management. This article discusses the aetiology, clinical presentation and
prognosis of OCD in the knee. It presents an algorithm for treatment,
which aims to promote healing of native hyaline cartilage and to
ensure joint congruity. Take home message: Although there is no clear consensus as to
the best treatment of OCD, every attempt should be made to retain
the osteochondral fragment when possible as, with a careful surgical
technique, there is potential for healing even in chronic lesions Cite this article:
Medial unicompartmental knee arthroplasty (UKA) is associated
with successful outcomes in carefully selected patient cohorts.
We hypothesised that severity and location of patellofemoral cartilage
lesions significantly influences functional outcome after Oxford
medial compartmental knee arthroplasty. We reviewed 100 consecutive UKAs at minimum eight-year follow-up
(96 to 132). A single surgeon performed all procedures. Patients
were selected based on clinical and plain radiographic assessment.
All patients had end-stage medial compartment osteoarthritis (OA)
with sparing of the lateral compartment and intact anterior cruciate ligaments.
None of the patients had end-stage patellofemoral OA, but patients
with anterior knee pain or partial thickness chondral loss were
not excluded. There were 57 male and 43 female patients. The mean
age at surgery was 69 years (41 to 82). At surgery the joint was
carefully inspected for patellofemoral chondral loss and this was documented
based on severity of cartilage loss (0 to 4 Outerbridge grading)
and topographic location (medial, lateral, central, and superior
or inferior). Functional scores collected included Oxford Knee Score
(OKS), patient satisfaction scale and University College Hospital
(UCH) knee score. Intraclass correlation was used to compare chondral
damage to outcomes.Aims
Patients and Methods
The aim of this consensus was to develop a definition of post-operative
fibrosis of the knee. An international panel of experts took part in a formal consensus
process composed of a discussion phase and three Delphi rounds.Aims
Patients and Methods
The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis was evaluated using the joint space width and Kellgren-Lawrence (KL) radiographic classification. The Objectives
Methods
We studied the bone mineral density (BMD) and
the bone mineral content (BMC) of the proximal tibia in patients with
a well-functioning uncemented Oxford medial compartment arthroplasty
using the Lunar iDXA bone densitometer. Our hypothesis was that
there would be decreased BMD and BMC adjacent to the tibial base
plate and increased BMD and BMC at the tip of the keel. There were 79 consecutive patients (33 men, 46 women) with a
mean age of 65 years (44 to 84) with a minimum two-year follow-up
(mean 2.6 years (2.0 to 5.0)) after unilateral arthroplasty, who
were scanned using a validated standard protocol where seven regions
of interest (ROI) were examined and compared with the contralateral
normal knee. All had well-functioning knees with a mean Oxford knee
score of 43 (14 to 48) and mean Knee Society function score of 90
(20 to 100), showing a correlation with the increasing scores and
higher BMC and BMD values in ROI 2 in the non-implanted knee relative
to the implanted knee (p = 0.013 and p = 0.015, respectively). The absolute and percentage changes in BMD and BMC were decreased
in all ROIs in the implanted knee compared with the non-implanted
knee, but this did not reach statistical significance. Bone loss
was markedly less than reported losses with total knee replacement. There was no significant association with side, although there
was a tendency for the BMC to decrease with age in men. The BMC
was less in the implanted side relative to the non-implanted side
in men compared with women in ROI 2 (p = 0.027), ROI 3 (p = 0.049)
and ROI 4 (p = 0.029). The uncemented Oxford medial compartment arthroplasty appears
to allow relative preservation of the BMC and BMD of the proximal
tibia, suggesting that the implant acts more physiologically than
total knee replacement. Peri-prosthetic bone loss is an important
factor in assessing long-term implant stability and survival, and
the results of this study are encouraging for the long-term outcome
of this arthroplasty. Cite this article:
The cause of dissatisfaction following total
knee arthroplasty (TKA) remains elusive. Much attention has been
focused on static mechanical alignment as a basis for surgical success and
optimising outcomes. More recently, research on both normal and
osteoarthritic knees, as well as kinematically aligned TKAs, has
suggested that other specific and dynamic factors may be more important
than a generic target of 0 ± 3º of a neutral axis. Consideration
of these other variables is necessary to understand ideal targets
and move beyond generic results. Cite this article:
The purpose of this study was to evaluate the
long-term functional and radiological outcomes of arthroscopic removal
of unstable osteochondral lesions with subchondral drilling in the
lateral femoral condyle. We reviewed the outcome of 23 patients
(28 knees) with stage III or IV osteochondritis dissecans lesions
of the lateral femoral condyle at a mean follow-up of 14 years (10
to 19). The functional clinical outcomes were assessed using the Lysholm
score, which improved from a mean of 38.1 ( We found radiological evidence of degenerative changes in the
third or fourth decade of life at a mean of 14 years after arthroscopic
excision of the loose body and subchondral drilling for an unstable
osteochondral lesion of the lateral femoral condyle. Clinical and
functional results were more satisfactory.
The aim of this study was to evaluate the risk
factors for dislocation of the bearing after a mobile-bearing Oxford medial
unicompartmental knee replacement (UKR) and to test the hypothesis
that surgical factors, as measured from post-operative radiographs,
are associated with its dislocation From a total of 480 UKRs performed between 2001 and 2012, in
391 patients with a mean age of 66.5 years (45 to 82) (316 female,
75 male), we identified 17 UKRs where bearing dislocation occurred.
The post-operative radiological measurements of the 17 UKRs and
51 matched controls were analysed using conditional logistic regression analysis.
The post-operative radiological measurements included post-operative
change in limb alignment, the position of the femoral and tibial
components, the resection depth of the proximal tibia, and the femoral component-posterior
condyle classification. We concluded that a post-operative decrease in the posterior
tibial slope relative to the pre-operative value was the only significant
determinant of dislocation of the bearing after medial Oxford UKR
(odds ratio 1.881; 95% confidence interval 1.272 to 2.779). A post-operative
posterior tibial slope <
8.45° and a difference between the pre-operative
and post-operative posterior tibial slope of >
2.19° may increase
the risk of dislocation. Cite this article:
