Aseptic loosening is the most common cause of failure following cemented total knee arthroplasty (TKA), and has been linked to poor cementation technique. We aimed to develop a consensus on the optimal technique for component cementation in TKA. A UK-based, three-round, online modified Delphi Expert Consensus Study was completed focusing on cementation technique in TKA. Experts were identified as having a minimum of five years’ consultant experience in the NHS and fulfilling any one of the following criteria: a ‘high volume’ knee arthroplasty practice (> 150 TKAs per annum) as identified from the National joint Registry of England, Wales, Northern Ireland and the Isle of Man; a senior author of at least five peer reviewed articles related to TKA in the previous five years; a surgeon who is named trainer for a post-certificate of comletion of training fellowship in TKA.Aims
Methods
The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. 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 unanimous.Aims
Methods
Aims. Inadvertent soft tissue damage caused by the oscillating saw during total knee arthroplasty (TKA) occurs when the sawblade passes beyond the bony boundaries into the soft tissue. The primary objective of this study is to assess the risk of inadvertent soft tissue damage during jig-based TKA by evaluating the excursion of the oscillating saw past the bony boundaries. The second objective is the investigation of the relation between this excursion and the surgeon’s experience level. Methods. A conventional jig-based TKA procedure with medial parapatellar approach was performed on 12 cadaveric knees by three experienced surgeons and three residents. During the proximal tibial resection, the motion of the oscillating saw with respect to the tibia was recorded. The distance of the outer point of this cutting portion to the edge of the bone was defined as the excursion of the oscillating saw. The excursion of the sawblade was evaluated in six zones containing the following structures: medial collateral ligament (MCL), posteromedial corner (PMC), iliotibial band (ITB), lateral collateral ligament (LCL), popliteus tendon (PopT), and neurovascular bundle (NVB). Results. The mean 75. th. percentile value of the excursion of all cases was mean 2.8 mm (SD 2.9) for the MCL zone, mean 4.8 mm (SD 5.9) for the PMC zone, mean 3.4 mm (SD 2.0) for the ITB zone, mean 6.3 mm (SD 4.8) for the LCL zone, mean 4.9 mm (SD 5.7) for the PopT zone, and mean 6.1 mm (SD 3.9) for the NVB zone. Experienced surgeons had a significantly lower excursion than residents. Conclusion. This study showed that the oscillating saw significantly passes the edge of the bone during the tibial resection in TKA, even in experienced
Patient dissatisfaction is not uncommon following primary total knee arthroplasty. One proposed method to alleviate this is by improving knee kinematics. Therefore, we aimed to answer the following research question: are there significant differences in knee kinematics based on the design of the tibial insert (cruciate-retaining (CR), ultra-congruent (UC), or medial congruent (MC))? Overall, 15 cadaveric knee joints were examined with a CR implant with three different tibial inserts (CR, UC, and MC) using an established knee joint simulator. The effects on coronal alignment, medial and lateral femoral roll back, femorotibial rotation, bony rotations (femur, tibia, and patella), and patellofemoral length ratios were determined.Aims
Methods
Conflicting clinical results are reported for the ATTUNE Total Knee Arthroplasty (TKA). This randomized controlled trial (RCT) evaluated five-year follow-up results comparing cemented ATTUNE and PFC-Sigma cruciate retaining TKAs, analyzing component migration as measured by radiostereometric analysis (RSA), clinical outcomes, patient-reported outcome measures (PROMs), and radiological outcomes. A total of 74 primary TKAs were included in this single-blind RCT. RSA examinations were performed, and PROMs and clinical outcomes were collected immediate postoperatively, and at three, six, 12, 24, and 60 months’ follow-up. Radiolucent lines (RLLs) were measured in standard anteroposterior radiographs at six weeks, and 12 and 60 months postoperatively.Aims
Methods
Classifying trochlear dysplasia (TD) is useful to determine the treatment options for patients suffering from patellofemoral instability (PFI). There is no consensus on which classification system is more reliable and reproducible for the purpose of guiding clinicians’ management of PFI. There are also concerns about the validity of the Dejour Classification (DJC), which is the most widely used classification for TD, having only a fair reliability score. The Oswestry-Bristol Classification (OBC) is a recently proposed system of classification of TD, and the authors report a fair-to-good interobserver agreement and good-to-excellent intraobserver agreement in the assessment of TD. The aim of this study was to compare the reliability and reproducibility of these two classifications. In all, six assessors (four consultants and two registrars) independently evaluated 100 axial MRIs of the patellofemoral joint (PFJ) for TD and classified them according to OBC and DJC. These assessments were again repeated by all raters after four weeks. The inter- and intraobserver reliability scores were calculated using Cohen’s kappa and Cronbach’s α.Aims
Methods
Unicompartmental knee arthroplasty (UKA) is the preferred treatment for anterior medial knee osteoarthritis (OA) owing to the rapid postoperative recovery. However, the risk factors for UKA failure remain controversial. The clinical data of Oxford mobile-bearing UKAs performed between 2011 and 2017 with a minimum follow-up of five years were retrospectively analyzed. Demographic, surgical, and follow-up data were collected. The Cox proportional hazards model was used to identify the risk factors that contribute to UKA failure. Kaplan-Meier survival was used to compare the effect of the prosthesis position on UKA survival.Aims
Methods
The antidiabetic agent metformin inhibits fibrosis in various organs. This study aims to elucidate the effects of hyperglycaemia and metformin on knee joint capsule fibrosis in mice. Eight-week-old wild-type (WT) and type 2 diabetic (db/db) mice were divided into four groups without or with metformin treatment (WT met(-/+), Db met(-/+)). Mice received daily intraperitoneal administration of metformin and were killed at 12 and 14 weeks of age. Fibrosis morphology and its related genes and proteins were evaluated. Fibroblasts were extracted from the capsules of 14-week-old mice, and the expression of fibrosis-related genes in response to glucose and metformin was evaluated in vitro.Aims
Methods
This study aimed to evaluate if total knee arthroplasty (TKA) femoral components aligned in either mechanical alignment (MA) or kinematic alignment (KA) are more biomimetic concerning trochlear sulcus orientation and restoration of trochlear height. Bone surfaces from 1,012 CT scans of non-arthritic femora were segmented using a modelling and analytics system. TKA femoral components (Triathlon; Stryker) were virtually implanted in both MA and KA. Trochlear sulcus orientation was assessed by measuring the distal trochlear sulcus angle (DTSA) in native femora and in KA and MA prosthetic femoral components. Trochlear anatomy restoration was evaluated by measuring the differences in medial, lateral, and sulcus trochlear height between native femora and KA and MA prosthetic femoral components.Aims
Methods
Knee osteoarthritis (OA) is characterized by a chronic inflammatory process involving multiple cytokine pathways, leading to articular cartilage degeneration. Intra-articular therapies using pharmaceutical or autologous anti-inflammatory factors offer potential non-surgical treatment options. Autologous protein solution (APS) is one such product that uses the patient’s blood to produce a concentrate of cells and anti-inflammatory cytokines. This study evaluated the effect of a specific APS intra-articular injection (nSTRIDE) on patient-reported outcome measures compared to saline in moderate knee OA. A parallel, double-blinded, placebo-controlled randomized controlled trial was conducted, where patients with unilateral moderate knee OA (Kellgren-Lawrence grade 2 or 3) received either nSTRIDE or saline (placebo) injection to their symptomatic knee. The primary outcome was the difference in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score at 12 months post-intervention. Secondary outcomes included WOMAC component scores, Knee injury and Osteoarthritis Outcome Score (KOOS), and visual analogue scale (VAS) scores at all follow-up timepoints (three, six, and 12 months).Aims
Methods
To map the Oxford Knee Score (OKS) and High Activity Arthroplasty Score (HAAS) items to a common scale, and to investigate the psychometric properties of this new scale for the measurement of knee health. Patient-reported outcome measure (PROM) data measuring knee health were obtained from the NHS PROMs dataset and Total or Partial Knee Arthroplasty Trial (TOPKAT). Assumptions for common scale modelling were tested. A graded response model (fitted to OKS item responses in the NHS PROMs dataset) was used as an anchor to calibrate paired HAAS items from the TOPKAT dataset. Information curves for the combined OKS-HAAS model were plotted. Bland-Altman analysis was used to compare common scale scores derived from OKS and HAAS items. A conversion table was developed to map between HAAS, OKS, and the common scale.Aims
Methods
The aim of this study was to compare a bicruciate-retaining (BCR) total knee arthroplasty (TKA) with a posterior cruciate-retaining (CR) TKA design in terms of kinematics, measured using fluoroscopy and stability as micromotion using radiostereometric analysis (RSA). A total of 40 patients with end-stage osteoarthritis were included in this randomized controlled trial. All patients performed a step-up and lunge task in front of a monoplane fluoroscope one year postoperatively. Femorotibial contact point (CP) locations were determined at every flexion angle and compared between the groups. RSA images were taken at baseline, six weeks, three, six, 12, and 24 months postoperatively. Clinical and functional outcomes were compared postoperatively for two years.Aims
Methods
To map literature on prognostic factors related to outcomes of revision total knee arthroplasty (rTKA), to identify extensively studied factors and to guide future research into what domains need further exploration. We performed a systematic literature search in MEDLINE, Embase, and Web of Science. The search string included multiple synonyms of the following keywords: "revision TKA", "outcome" and "prognostic factor". We searched for studies assessing the association between at least one prognostic factor and at least one outcome measure after rTKA surgery. Data on sample size, study design, prognostic factors, outcomes, and the direction of the association was extracted and included in an evidence map.Aims
Methods
Despite new technologies for total knee arthroplasty (TKA), approximately 20% of patients are dissatisfied. A major reason for dissatisfaction and revision surgery after TKA is persistent pain. The radiological grade of osteoarthritis (OA) preoperatively has been investigated as a predictor of the outcome after TKA, with conflicting results. The aim of this study was to determine if there is a difference in the intensity of pain 12 months after TKA in relation to the preoperative radiological grade of OA alone, and the combination of the intensity of preoperative pain and radiological grade of OA. The preoperative data of 300 patients who underwent primary TKA were collected, including clinical information (age, sex, preoperative pain), psychological variables (depression, anxiety, pain catastrophizing, anticipated pain), and quantitative sensory testing (temporal summation, pressure pain thresholds, conditioned pain modulation). The preoperative radiological severity of OA was graded according to the Kellgren-Lawrence (KL) classification. Persistent pain in the knee was recorded 12 months postoperatively. Generalized linear models explored differences in postoperative pain according to the KL grade, and combined preoperative pain and KL grade. Relative risk models explored which preoperative variables were associated with the high preoperative pain/low KL grade group.Aims
Methods
To identify the responsiveness, minimal clinically important difference (MCID), minimal clinical important change (MIC), and patient-acceptable symptom state (PASS) thresholds in the 36-item Short Form Health Survey questionnaire (SF-36) (v2) for each of the eight dimensions and the total score following total knee arthroplasty (TKA). There were 3,321 patients undergoing primary TKA with preoperative and one-year postoperative SF-36 scores. At one-year patients were asked how satisfied they were and “How much did the knee arthroplasty surgery improve the quality of your life?”, which was graded as: great, moderate, little (n = 277), none (n = 98), or worse.Aims
Methods
Both the femoral and tibial component are usually cemented at revision total knee arthroplasty (rTKA), while stems can be added with either cemented or press-fit (hybrid) fixation. The aim of this study was to compare the long-term stability of rTKA with cemented and press-fitted stems, using radiostereometric analysis (RSA). This is a follow-up of a randomized controlled trial, initially involving 32 patients, of whom 19 (nine cemented, ten hybrid) were available for follow-up ten years postoperatively, when further RSA measurements were made. Micromotion of the femoral and tibial components was assessed using model-based RSA software (RSAcore). The clinical outcome was evaluated using the Knee Society Score (KSS), the Knee injury and Osteoarthritis Outcome Score (KOOS), and visual analogue scale (pain and satisfaction).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
Intraoperative pressure sensors allow surgeons to quantify soft-tissue balance during total knee arthroplasty (TKA). The aim of this study was to determine whether using sensors to achieve soft-tissue balance was more effective than manual balancing in improving outcomes in TKA. A multicentre randomized trial compared the outcomes of sensor balancing (SB) with manual balancing (MB) in 250 patients (285 TKAs). The primary outcome measure was the mean difference in the four Knee injury and Osteoarthritis Outcome Score subscales (ΔKOOS4) in the two groups, comparing the preoperative and two-year scores. Secondary outcomes included intraoperative balance data, additional patient-reported outcome measures (PROMs), and functional measures.Aims
Methods
Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs. In total, 34 patients (13 female, 21 male; mean age 62 years (41 to 79); BMI 29.7 kg/m2 (23.6 to 42.1)) with 38 medial Oxford partial UKAs (20 left, 18 right; 19 cementless, 14 cemented, and five hybrid) were prospectively followed with sequential 99mTc-hydroxymethane diphosphonate single photon emission CT (SPECT)/CT preoperatively, and at one and two years postoperatively. Changes in mean osteoblastic activity were investigated using a tracer localization scheme with volumes of interest (VOIs), reported by normalized mean tracer values. A SPECT/CT registration platform additionally explored cortical tracer evolution in zones of interest identified by previous experimental research.Aims
Methods
This study aimed to investigate the relationship between changes in patellar height and clinical outcomes at a mean follow-up of 7.7 years (5 to 10) after fixed-bearing posterior-stabilized total knee arthroplasty (PS-TKA). We retrospectively evaluated knee radiographs of 165 knees, which underwent fixed-bearing PS-TKA with patella resurfacing. The incidence of patella baja and changes in patellar height over a minimum of five years of follow-up were determined using Insall-Salvati ratio (ISR) measurement. We examined whether patella baja (ISR < 0.8) at final follow-up affected clinical outcomes, knee joint range of motion (ROM), and Knee Society Score (KSS). We also assessed inter- and intrarater reliability of ISR measurements and focused on the relationship between patellar height reduction beyond measurement error and clinical outcomes.Aims
Methods
In the last decade, interest in partial knee arthroplasties and bicruciate retaining total knee arthroplasties has increased. In addition, patient-related outcomes and functional results such as range of movement and ambulation may be more promising with less invasive procedures such as bicompartmental arthroplasty (BCA). The purpose of this study is to evaluate clinical and radiological outcomes after a third-generation patellofemoral arthroplasty (PFA) combined with a medial or lateral unicompartmental knee arthroplasty (UKA) at mid- to long-term follow-up. A total of 57 procedures were performed. In 45 cases, a PFA was associated with a medial UKA and, in 12, with a lateral UKA. Patients were followed with validated patient-reported outcome measures (Oxford Knee Score (OKS), EuroQol five-dimension questionnaire (EQ-5D), EuroQoL Visual Analogue Scale (EQ-VAS)), the Knee Society Score (KSS), the Forgotten Joint Score (FJS), and radiological analysis.Aims
Methods
The objective of this study is to assess the use of ultrasound (US) as a radiation-free imaging modality to reconstruct 3D anatomy of the knee for use in preoperative templating in knee arthroplasty. Using an US system, which is fitted with an electromagnetic (EM) tracker that is integrated into the US probe, allows 3D tracking of the probe, femur, and tibia. The raw US radiofrequency (RF) signals are acquired and, using real-time signal processing, bone boundaries are extracted. Bone boundaries and the tracking information are fused in a 3D point cloud for the femur and tibia. Using a statistical shaping model, the patient-specific surface is reconstructed by optimizing bone geometry to match the point clouds. An accuracy analysis was conducted for 17 cadavers by comparing the 3D US models with those created using CT. US scans from 15 users were compared in order to examine the effect of operator variability on the output.Aims
Methods
MRI has been suggested as an objective method of assessing anterior crucate ligament (ACL) graft “ligamentization” after reconstruction. It has been proposed that the MRI appearances could be used as an indicator of graft maturity and used as part of a return-to-sport assessment. The aim of this study was to evaluate the correlation between MRI graft signal and postoperative functional scores, anterior knee laxity, and patient age at operation. A consecutive cohort of 149 patients who had undergone semitendinosus autograft ACL reconstruction, using femoral and tibial adjustable loop fixations, were evaluated retrospectively postoperatively at two years. All underwent MRI analysis of the ACL graft, performed using signal-to-noise quotient (SNQ) and the Howell score. Functional outcome scores (Lysholm, Tegner, International Knee Documentation Committee (IKDC) subjective, and IKDC objective) were obtained and all patients underwent instrumented side-to-side anterior laxity differential laxity testing.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
Meeting preoperative expectations is known to be of major influence on postoperative satisfaction after total knee arthroplasty (TKA). Improved management of expectation, resulting in more realistic expectations can potentially lead to higher postoperative satisfaction. The objective of this study was to assess the effect of an additional preoperative education module, addressing realistic expectations for long-term functional recovery, on postoperative satisfaction and expectation fulfilment. In total, 204 primary TKA patients with osteoarthritis were enrolled in this randomized controlled trial (RCT). Patients were allocated to either usual preoperative education (control group) or usual education plus an additional module on realistic expectations (intervention group). Primary outcome was being very satisfied (numerical rating scale for satisfaction ≥ 8) with the treatment result at 12 months' follow-up. Other outcomes were change in preoperative expectations and postoperative expectation fulfilment.Aims
Methods
Porous metaphyseal cones can be used for fixation in revision total knee arthroplasty (rTKA) and complex TKAs. This metaphyseal fixation has led to some surgeons using shorter cemented stems instead of diaphyseal engaging cementless stems with a potential benefit of ease of obtaining proper alignment without being beholden to the diaphysis. The purpose of this study was to evaluate short term clinical and radiographic outcomes of a series of TKA cases performed using 3D-printed metaphyseal cones. A retrospective review of 86 rTKAs and nine complex primary TKAs, with an average age of 63.2 years (SD 8.2) and BMI of 34.0 kg/m2 (SD 8.7), in which metaphyseal cones were used for both femoral and tibial fixation were compared for their knee alignment based on the type of stem used. Overall, 22 knees had cementless stems on both sides, 52 had cemented stems on both sides, and 15 had mixed stems. Postoperative long-standing radiographs were evaluated for coronal and sagittal plane alignment. Adjusted logistic regression models were run to assess malalignment hip-knee-ankle (HKA) alignment beyond ± 3° and sagittal alignment of the tibial and femoral components ± 3° by stem type.Aims
Methods
Alternative alignment concepts, including kinematic and restricted kinematic, have been introduced to help improve clinical outcomes following total knee arthroplasty (TKA). The purpose of this study was to evaluate the clinical results, along with patient satisfaction, following TKA using the concept of restricted kinematic alignment. A total of 121 consecutive TKAs performed between 11 February 2018 to 11 June 2019 with preoperative varus deformity were reviewed at minimum one-year follow-up. Three knees were excluded due to severe preoperative varus deformity greater than 15°, and a further three due to requiring revision surgery, leaving 109 patients and 115 knees to undergo primary TKA using the concept of restricted kinematic alignment with advanced technology. Patients were stratified into three groups based on the preoperative limb varus deformity: Group A with 1° to 5° varus (43 knees); Group B between 6° and 10° varus (56 knees); and Group C with varus greater than 10° (16 knees). This study group was compared with a matched cohort of 115 TKAs and 115 patients using a neutral mechanical alignment target with manual instruments performed from 24 October 2016 to 14 January 2019.Aims
Methods
The purpose is to determine the non-inferiority of a smartphone-based exercise educational care management system after primary knee arthroplasty compared with a traditional in-person physiotherapy rehabilitation model. A multicentre prospective randomized controlled trial was conducted evaluating the use of a smartphone-based care management system for primary total knee arthroplasty (TKA) and partial knee arthroplasty (PKA). Patients in the control group (n = 244) received the respective institution’s standard of care with formal physiotherapy. The treatment group (n = 208) were provided a smartwatch and smartphone application. Early outcomes assessed included 90-day knee range of movement, EuroQoL five-dimension five-level score, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) score, 30-day single leg stance (SLS) time, Time up and Go (TUG) time, and need for manipulation under anaesthesia (MUA).Aims
Methods
The purpose of this study was to compare the radiological outcomes of manual versus robotic-assisted medial unicompartmental knee arthroplasty (UKA). Postoperative radiological outcomes from 86 consecutive robotic-assisted UKAs (RAUKA group) from a single academic centre were retrospectively reviewed and compared to 253 manual UKAs (MUKA group) drawn from a prior study at our institution. Femoral coronal and sagittal angles (FCA, FSA), tibial coronal and sagittal angles (TCA, TSA), and implant overhang were radiologically measured to identify outliers.Aims
Methods
Mobile-bearing unicompartmental knee replacements
(UKRs) with a flat tibial plateau have not performed well in the
lateral compartment, owing to a high dislocation rate. This led
to the development of the Domed Lateral Oxford UKR (Domed OUKR)
with a biconcave bearing. The aim of this study was to assess the
survival and clinical outcomes of the Domed OUKR in a large patient
cohort in the medium term. We prospectively evaluated 265 consecutive knees with isolated
disease of the lateral compartment and a mean age at surgery of
64 years (32 to 90). At a mean follow-up of four years (. sd. 2.2,
(0.5 to 8.3)) the mean Oxford knee score was 40 out of 48 (. sd. 7.4).
A total of 12 knees (4.5%) had re-operations, of which four (1.5%)
were for dislocation. All dislocations occurred in the first two
years. Two (0.8%) were secondary to significant trauma that resulted
in ruptured ligaments, and two (0.8%) were spontaneous. In four
patients (1.5%) the UKR was converted to a primary TKR. Survival
at eight years, with failure defined as any revision, was 92.1%
(95% confidence interval 81.3 to 100). . The Domed Lateral OUKR gives good clinical outcomes, low re-operation
and revision rates and a low dislocation rate in patients with isolated
lateral compartmental disease, in the
This study aims to investigate the effects of posterior tibial slope (PTS) on knee kinematics involved in the post-cam mechanism in bi-cruciate stabilized (BCS) total knee arthroplasty (TKA) using computer simulation. In total, 11 different PTS (0° to 10°) values were simulated to evaluate the effect of PTS on anterior post-cam contact conditions and knee kinematics in BCS TKA during weight-bearing stair climbing (from 86° to 6° of knee flexion). Knee kinematics were expressed as the lowest points of the medial and lateral femoral condyles on the surface of the tibial insert, and the anteroposterior translation of the femoral component relative to the tibial insert.Aims
Methods
This study aimed to identify the tibial component and femoral component coronal angles (TCCAs and FCCAs), which concomitantly are associated with the best outcomes and survivorship in a cohort of fixed-bearing, cemented, medial unicompartmental knee arthroplasties (UKAs). We also investigated the potential two-way interactions between the TCCA and FCCA. Prospectively collected registry data involving 264 UKAs from a single institution were analyzed. The TCCAs and FCCAs were measured on postoperative radiographs and absolute angles were analyzed. Clinical assessment at six months, two years, and ten years was undertaken using the Knee Society Knee score (KSKS) and Knee Society Function score (KSFS), the Oxford Knee Score (OKS), the 36-Item Short-Form Health Survey questionnaire (SF-36), and range of motion (ROM). Fulfilment of expectations and satisfaction was also recorded. Implant survivorship was reviewed at a mean follow-up of 14 years (12 to 16). Multivariate regression models included covariates, TCCA, FCCA, and two-way interactions between them. Partial residual graphs were generated to identify angles associated with the best outcomes. Kaplan-Meier analysis was used to compare implant survivorship between groups.Aims
Methods
The James Lind Alliance aims to bring patients, carers, and clinicians together to identify uncertainties regarding care. A Priority Setting Partnership was established by the British Association for Surgery of the Knee in conjunction with the James Lind Alliance to identify research priorities related to the assessment, management, and rehabilitation of patients with persistent symptoms after knee arthroplasty. The project was conducted using the James Lind Alliance protocol. A steering group was convened including patients, surgeons, anaesthetists, nurses, physiotherapists, and researchers. Partner organizations were recruited. A survey was conducted on a national scale through which patients, carers, and healthcare professionals submitted key unanswered questions relating to problematic knee arthroplasties. These were analyzed, aggregated, and synthesized into summary questions and the relevant evidence was checked. After confirming that these were not answered in the current literature, 32 questions were taken forward to an interim prioritization survey. Data from this survey informed a shortlist taken to a final consensus meeting.Aims
Methods
The primary objective of this study was to compare migration of the cemented ATTUNE fixed bearing cruciate retaining tibial component with the cemented Press-Fit Condylar (PFC)-sigma fixed bearing cruciate retaining tibial component. The secondary objectives included comparing clinical and radiological outcomes and Patient Reported Outcome Measures (PROMs). A single blinded randomized, non-inferiority study was conducted including 74 patients. Radiostereometry examinations were made after weight bearing, but before hospital discharge, and at three, six, 12, and 24 months postoperatively. PROMS were collected preoperatively and at three, six, 12, and 24 months postoperatively. Radiographs for measuring radiolucencies were collected at two weeks and two years postoperatively.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
Total knee replacement (TKR) is an operation
that can be performed with or without the use of a tourniquet. Meta-analyses
of the available Level-1 studies have demonstrated that the use
of a tourniquet leads to a significant reduction in blood loss.
The opponents for use of a tourniquet cite development of complications
such as skin bruising, neurovascular injury, and metabolic disturbance
as drawbacks. Although there may certainly be reason for concern
in arteriopathic patients, there is little evidence that routine
use of a tourniquet during TKR results in any of the above complications.
The use of a tourniquet, on the other
Recent studies have suggested that corticosteroid injections into the knee may harm the joint resulting in cartilage loss and possibly accelerating the progression of osteoarthritis (OA). The aim of this study was to assess whether patients with, or at risk of developing, symptomatic osteoarthritis of the knee who receive intra-articular corticosteroid injections have an increased risk of requiring arthroplasty. We used data from the Osteoarthritis Initiative (OAI), a multicentre observational cohort study that followed 4,796 patients with, or at risk of developing, osteoarthritis of the knee on an annual basis with follow-up available up to nine years. Increased risk for symptomatic OA was defined as frequent knee symptoms (pain, aching, or stiffness) without radiological evidence of OA and two or more risk factors, while OA was defined by the presence of both femoral osteophytes and frequent symptoms in one or both knees. Missing data were imputed with multiple imputations using chained equations. Time-dependent propensity score matching was performed to match patients at the time of receving their first injection with controls. The effect of corticosteroid injections on the rate of subsequent (total and partial) knee arthroplasty was estimated using Cox proportional-hazards survival analyses.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 analyze the true costs associated with preoperative CT scans performed for robotic-assisted total knee arthroplasty (RATKA) planning and to determine the value of a formal radiologist’s report of these studies. We reviewed 194 CT reports of 176 sequential patients who underwent primary RATKA by a single surgeon at a suburban teaching hospital. CT radiology reports were reviewed for the presence of incidental findings that might change the management of the patient. Payments for the scans, including the technical and professional components, for 330 patients at two hospitals were also recorded and compared.Aims
Methods
The mobile bearing Oxford unicompartmental knee arthroplasty (OUKA) is recommended to be performed with the leg in the hanging leg (HL) position, and the thigh placed in a stirrup. This comparative cadaveric study assesses implant positioning and intraoperative kinematics of OUKA implanted either in the HL position or in the supine leg (SL) position. A total of 16 fresh-frozen knees in eight human cadavers, without macroscopic anatomical defects, were selected. The knees from each cadaver were randomized to have the OUKA implanted in the HL or SL position.Aims
Methods
The aim of this study was to determine if the local delivery of vancomycin and tobramycin in primary total knee arthroplasty (TKA) can achieve intra-articular concentrations exceeding the minimum inhibitory concentration thresholds for bacteria causing acute prosthetic joint infection (PJI). Using a retrospective single-institution database of all primary TKAs performed between January 1 2014 and May 7 2019, we identified patients with acute PJI that were managed surgically within 90 days of the initial procedure. The organisms from positive cultures obtained at the time of revision were tested for susceptibility to gentamicin, tobramycin, and vancomycin. A prospective study was then performed to determine the intra-articular antibiotic concentration on postoperative day one after primary TKA using one of five local antibiotic delivery strategies with tobramycin and/or vancomycin mixed into the polymethylmethacrylate (PMMA) or vancomycin powder.Aims
Methods
The aim of this study was to assess the effect of posterior cruciate ligament (PCL) resection on flexion-extension gaps, mediolateral soft-tissue laxity, fixed flexion deformity (FFD), and limb alignment during posterior-stabilized (PS) total knee arthroplasty (TKA). This prospective study included 110 patients with symptomatic osteoarthritis of the knee undergoing primary robot-assisted PS TKA. All operations were performed by a single surgeon using a standard medial parapatellar approach. Optical motion capture technology with fixed femoral and tibial registration pins was used to assess gaps before and after PCL resection in extension and 90° knee flexion. Measurements were made after excision of the anterior cruciate ligament and prior to bone resection. There were 54 men (49.1%) and 56 women (50.9%) with a mean age of 68 years (Aims
Patients and Methods
Limited evidence is available on mid-term outcomes of robotic-arm assisted (RA) partial knee arthroplasty (PKA). Therefore, the purpose of this study was to evaluate mid-term survivorship, modes of failure, and patient-reported outcomes of RA PKA. A retrospective review of patients who underwent RA PKA between June 2007 and August 2016 was performed. Patients received a fixed-bearing medial or lateral unicompartmental knee arthroplasty (UKA), patellofemoral arthroplasty (PFA), or bicompartmental knee arthroplasty (BiKA; PFA plus medial UKA). All patients completed a questionnaire regarding revision surgery, reoperations, and level of satisfaction. Knee Injury and Osteoarthritis Outcome Scores (KOOS) were assessed using the KOOS for Joint Replacement Junior survey.Aims
Methods
The aims of this study were to compare the mean duration of antibiotic release and the mean zone of inhibition between vancomycin-loaded porous tantalum cylinders and antibiotic-loaded bone cement at intervals, and to evaluate potential intrinsic antimicrobial properties of tantalum in an Ten porous tantalum cylinders and ten cylinders of cement were used. The tantalum cylinders were impregnated with vancomycin, which was also added during preparation of the cylinders of cement. The cylinders were then placed on agar plates inoculated with MSSA. The diameter of the inhibition zone was measured each day, and the cylinders were transferred to a new inoculated plate. Inhibition zones were measured with a Vernier caliper and using an automated computed evaluation, and the intra- and interobserver reproducibility were measured. The mean inhibition zones between the two groups were compared with Wilcoxon’s test.Aims
Materials and Methods
Robotic-assisted unicompartmental knee arthroplasty (UKA) promises accurate implant placement with the potential of improved survival and functional outcomes. The aim of this study was to present the current evidence for robotic-assisted UKA and describe the outcome in terms of implant positioning, range of movement (ROM), function and survival, and the types of robot and implants that are currently used. A search of PubMed and Medline was performed in October 2018 in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included “robotic”, “knee”, and “surgery”. The criteria for inclusion was any study describing the use of robotic UKA and reporting implant positioning, ROM, function, and survival for clinical, cadaveric, or dry bone studies.Aims
Materials and Methods
Revision total knee arthroplasty (rTKA) accounts for approximately 5% to 10% of all TKAs. Although the complexity of these procedures is well recognized, few investigators have evaluated the cost and value-added with the implementation of a dedicated revision arthroplasty service. The aim of the present study is to compare and contrast surgeon productivity in several differing models of activity. All patients that underwent primary or revision TKA from January 2016 to June 2018 were included as the primary source of data. All rTKA patients were categorized by the number of components revised (e.g. liner exchange, two or more components). Three models were used to assess the potential surgical productivity of a dedicated rTKA service : 1) work relative value unit (RVU) Aims
Materials 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
The purpose of this multicentre observational study was to investigate the association between intraoperative component positioning and soft-tissue balancing on short-term clinical outcomes in patients undergoing robotic-arm assisted unicompartmental knee arthroplasty (UKA). Between 2013 and 2016, 363 patients (395 knees) underwent robotic-arm assisted UKAs at two centres. Pre- and postoperatively, patients were administered Knee Injury and Osteoarthritis Score (KOOS) and Forgotten Joint Score-12 (FJS-12). Results were stratified as “good” and “bad” if KOOS/FJS-12 were more than or equal to 80. Intraoperative, post-implantation robotic data relative to CT-based components placement were collected and classified. Postoperative complications were recorded.Aims
Patients and Methods
Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes. A retrospective review was undertaken of the first 100 consecutive patients with five-year follow-up following SAIPH TKA performed by the senior authors. The data that were collected included the demographics of the patients, clinical findings, the rate of intraoperative ligamentous release, patient-reported outcome measures (PROMS), radiological assessment, complications, and all-cause revision. Revision data were cross-checked with a national registry.Aims
Patients and Methods
In Asia and the Middle-East, people often flex their knees deeply
in order to perform activities of daily living. The purpose of this
study was to investigate the 3D kinematics of normal knees during
high-flexion activities. Our hypothesis was that the femorotibial
rotation, varus-valgus angle, translations, and kinematic pathway
of normal knees during high-flexion activities, varied according
to activity. We investigated the Aims
Materials and Methods
To compare the effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament (ACL) reconstruction animal model. Anterior cruciate ligament reconstruction using the plantaris tendon as graft material was performed on both knees of 24 rabbits (48 knees) to mimic ACL reconstruction by two different suspensory fixation devices for graft fixation. For the adjustable fixation device model (Socket group; group S), a 5 mm deep socket was created in the lateral femoral condyle (LFC) of the right knee. For the fixed-loop model (Tunnel group; group T), a femoral tunnel penetrating the LFC was created in the left knee. Animals were sacrificed at four and eight weeks after surgery for histological evaluation and biomechanical testing.Objectives
Methods
The aims of this study were to determine the proportion of patients
with outlier varus or valgus alignment in kinematically aligned
total knee arthroplasty (TKA), whether those with outlier varus
or valgus alignment have higher forces in the medial or lateral
compartments of the knee than those with in-range alignment and
whether measurements of the alignment of the limb, knee and components
predict compartment forces. The intra-operative forces in the medial and lateral compartments
were measured with an instrumented tibial insert in 67 patients
who underwent a kinematically aligned TKA during passive movement.
The mean of the forces at full extension, 45° and 90° of flexion
determined the force in the medial and lateral compartments. Measurements
of the alignment of the limb and the components included the hip-knee-ankle
(HKA) angle, proximal medial tibial angle (PMTA), and distal lateral
femoral angle (DLFA). Measurements of the alignment of the knee
and the components included the tibiofemoral angle (TFA), tibial
component angle (TCA) and femoral component angle (FCA). Alignment was
measured on post-operative, non-weight-bearing anteroposterior (AP)
scanograms and categorised as varus or valgus outlier or in-range
in relation to mechanically aligned criteria.Aims
Patients and Methods
The aims of this study were to compare the efficacy and safety
of intra-articular and intravenous (IV) tranexamic acid (TXA) in
controlling perioperative blood loss in total knee arthroplasty
(TKA) using a randomized, double-blinded equivalence trial. A total of 182 patients aged between 45 and 75 years undergoing
unilateral TKA at a tertiary centre were randomized to receive TXA,
either 1.5 g intra-articularly after closure of the wound (n = 91)
or two doses of 10 mg/kg IV (n = 91). The primary outcome measure
was the reduction in the level of haemoglobin (Hb) in the blood
on the fifth postoperative day. Secondary outcome measures were
the total, visible, and hidden blood losses (TBL, VBL, HBL). We
assumed equivalence of the primary outcome in both routes with a
margin of ± 0.35gm/dl. Block randomization using computer-generated
random numbers was used. The patients and the assessor of outcome were
blinded.Aims
Patients and Methods
Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA. We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions.Objectives
Methods
Advances in polyethylene (PE) in total hip arthroplasty
have led to interest and increased use of highly crosslinked PE
(HXLPE) in total knee arthroplasty (TKA). Biomechanical data suggest
improved wear characteristics for HXLPE inserts over conventional
PE in TKA. Short-term results from registry data and few clinical
trials are promising. Our aim is to present a review of the history
of HXLPEs, the use of HXLPE inserts in TKA, concerns regarding potential mechanical
complications, and a thorough review of the available biomechanical
and clinical data. Cite this article:
To assess the effect of high tibial and distal femoral osteotomies
(HTO and DFO) on the pressure characteristics of the ankle joint. Varus and valgus malalignment of the knee was simulated in human
cadaver full-length legs. Testing included four measurements: baseline
malalignment, 5° and 10° re-aligning osteotomy, and control baseline
malalignment. For HTO, testing was rerun with the subtalar joint
fixed. In order to represent half body weight, a 300 N force was applied
onto the femoral head. Intra-articular sensors captured ankle pressure.Aims
Materials and Methods
Fractures around total knee arthroplasties pose
a significant surgical challenge. Most can be managed with osteosynthesis
and salvage of the replacement. The techniques of fixation of these
fractures and revision surgery have evolved and so has the assessment
of outcome. This specialty update summarises the current evidence
for the classification, methods of fixation, revision surgery and
outcomes of the management of periprosthetic fractures associated
with total knee arthroplasty. Cite this article:
Malrotation of the femoral component can result in post-operative complications in total knee arthroplasty (TKA), including patellar maltracking. Therefore, we used computational simulation to investigate the influence of femoral malrotation on contact stresses on the polyethylene (PE) insert and on the patellar button as well as on the forces on the collateral ligaments. Validated finite element (FE) models, for internal and external malrotations from 0° to 10° with regard to the neutral position, were developed to evaluate the effect of malrotation on the femoral component in TKA. Femoral malrotation in TKA on the knee joint was simulated in walking stance-phase gait and squat loading conditions.Objectives
Materials and Methods
To compare the gait of unicompartmental knee arthroplasty (UKA)
and total knee arthroplasty (TKA) patients with healthy controls,
using a machine-learning approach. 145 participants (121 healthy controls, 12 patients with cruciate-retaining
TKA, and 12 with mobile-bearing medial UKA) were recruited. The
TKA and UKA patients were a minimum of 12 months post-operative,
and matched for pattern and severity of arthrosis, age, and body
mass index. Participants walked on an instrumented treadmill until their
maximum walking speed was reached. Temporospatial gait parameters,
and vertical ground reaction force data, were captured at each speed.
Oxford knee scores (OKS) were also collected. An ensemble of trees
algorithm was used to analyse the data: 27 gait variables were used
to train classification trees for each speed, with a binary output
prediction of whether these variables were derived from a UKA or
TKA patient. Healthy control gait data was then tested by the decision
trees at each speed and a final classification (UKA or TKA) reached
for each subject in a majority voting manner over all gait cycles
and speeds. Top walking speed was also recorded.Aims
Patients and Methods
The interest in unicompartmental knee arthroplasty (UKA) for
medial osteoarthritis has increased rapidly but the long-term follow-up
of the Oxford UKAs has yet to be analysed in non-designer centres.
We have examined our ten- to 15-year clinical and radiological follow-up
data for the Oxford Phase III UKAs. Between January 1999 and January 2005 a total of 138 consecutive
Oxford Phase III arthroplasties were performed by a single surgeon
in 129 patients for medial compartment osteoarthritis (71 right
and 67 left knees, mean age 72.0 years (47 to 91), mean body mass
index 28.2 (20.7 to 52.2)). Both clinical data and radiographs were
prospectively recorded and obtained at intervals. Of the 129 patients,
32 patients (32 knees) died, ten patients (12 knees) were not able
to take part in the final clinical and radiological assessment due
to physical and mental conditions, but via telephone interview it
was confirmed that none of these ten patients (12 knees) had a revision
of the knee arthroplasty. One patient (two knees) was lost to follow-up.Aims
Patients and Methods
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. 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 plain radiographs. To study the influence of SSM model accuracy, the 3D mJSW measurement was repeated with models from the actual bones, obtained from CT scans.Objectives
Materials and Methods
The purpose of this study was to clarify the appearance of the reparative tissue on the articular surface and to analyse the properties of the reparative tissue after hemicallotasis osteotomy (HCO) using MRI T1ρ and T2 mapping. Coronal T1ρ and T2 mapping and three-dimensional gradient-echo images were obtained from 20 subjects with medial knee osteoarthritis. We set the regions of interest (ROIs) on the full-thickness cartilage of the medial femoral condyle (MFC) and medial tibial plateau (MTP) of the knee and measured the cartilage thickness (mm) and T1ρ and T2 relaxation times (ms). Statistical analysis of time-dependent changes in the cartilage thickness and the T1ρ and T2 relaxation times was performed using one-way analysis of variance, and Scheffe’s test was employed for Objectives
Methods
We explored the literature surrounding whether
allergy and hypersensitivity has a clinical basis for implant selection
in total knee arthroplasty (TKA). In error, the terms hypersensitivity
and allergy are often used synonymously. Although a relationship
is present, we could not find any evidence of implant failure due
to allergy. There is however increasing basic science that suggests
a link between loosening and metal ion production. This is not an
allergic response but is a potential problem. With a lack of evidence
logically there can be no justification to use ‘hypoallergenic’
implants in patients who have pre-existing skin sensitivity to the
metals used in TKA. Cite this article:
Because there have been no standard methods to determine pre-operatively
the thickness of resection of the proximal tibia in unicompartmental
knee arthroplasty (UKA), information about the relationship between
the change of limb alignment and the joint line elevation would
be useful for pre-operative planning. The purpose of this study
was to clarify the correlation between the change of limb alignment
and the change of joint line height at the medial compartment after
UKA. A consecutive series of 42 medial UKAs was reviewed retrospectively.
These patients were assessed radiographically both pre- and post-operatively
with standing anteroposterior radiographs. The thickness of bone
resection at the proximal tibia and the distal femur was measured
radiographically. The relationship between the change of femorotibial
angle (δFTA) and the change of joint line height, was analysed.Objectives
Methods
Although the vast majority of patients that undergo
total knee replacement have satisfactory outcomes with a generally
low complication rate, occasionally a patient will be encountered
that has had multiple failed surgeries, and now reaches a crossroad
as to whether limb salvage will be acceptable or not. Cite this article:
We report the long-term outcome of 33 patients
(37 knees) who underwent proximal tibial open-wedge osteotomy with
hemicallotasis (HCO) for medial osteoarthritis of the knee between
1995 and 2000. Among these, 29 patients with unilateral HCO were
enrolled and 19 were available for review at a mean of 14.2 years
(10 to 15.7) post-operatively. For these 19 patients, the mean Hospital
for Special Surgery knee score was 60 (57 to 62) pre-operatively
and 85 (82 to 87) at final follow-up (p <
0.001; paired Cite this article:
A total of 187 patients with primary osteoarthritis
(OA) of the knee undergoing total knee replacement (TKR) were randomly
divided into two groups, one of which underwent synovectomy. The
patients and assessors were blinded to the randomisation both before
and after surgery. The duration of surgery, hospitalisation period,
concealed bleeding, drainage volume, blood transfusion rate and
range of movement of the knee at three days after the operation
were analysed. Patients were followed up at four weeks and 12 months
after their operation, and a visual analogue score (VAS) for pain,
Knee Society score (KSS) and a patellar ballottement test were compared
between the groups. The mean amount of concealed bleeding was higher in the synovectomy
group compared with the control group (1.24 l (0.08 to 3.28) Cite this article:
Dunkin Hartley guinea pigs, a commonly used animal model of osteoarthritis,
were used to determine if high frequency ultrasound can ensure intra-articular
injections are accurately positioned in the knee joint. A high-resolution small animal ultrasound system with a 40 MHz
transducer was used for image-guided injections. A total of 36 guinea
pigs were anaesthetised with isoflurane and placed on a heated stage.
Sterile needles were inserted directly into the knee joint medially,
while the transducer was placed on the lateral surface, allowing
the femur, tibia and fat pad to be visualised in the images. B-mode
cine loops were acquired during 100 µl. We assessed our ability
to visualise 1) important anatomical landmarks, 2) the needle and
3) anatomical changes due to the injection. Objective
Methods
The use of hinged implants in primary total knee
replacement (TKR) should be restricted to selected indications and mainly
for elderly patients. Potential indications for a rotating hinge
or pure hinge implant in primary TKR include: collateral ligament
insufficiency, severe varus or valgus deformity (>
20°) with necessary
relevant soft-tissue release, relevant bone loss including insertions
of collateral ligaments, gross flexion-extension gap imbalance,
ankylosis, or hyperlaxity. Although data reported in the literature
are inconsistent, clinical results depend on implant design, proper
technical use, and adequate indications. We present our experience
with a specific implant type that we have used for over 30 years
and which has given our elderly patients good mid-term results.
Because revision of implants with long cemented stems can be very
challenging, an effort should be made in the future to use shorter stems
in modular versions of hinged implants. Cite this article:
Accurate, reproducible outcome measures are essential
for the evaluation of any orthopaedic procedure, in both clinical
practice and research. Commonly used patient-reported outcome measures (PROMs) have
drawbacks such as ‘floor’ and ‘ceiling’ effects, limitations of
worldwide adaptability and an inability to distinguish pain from
function. They are also unable to measure the true outcome of an
intervention rather than a patient’s perception of that outcome. Performance-based functional outcome tools may address these
problems. It is important that both clinicians and researchers are
aware of these measures when dealing with high-demand patients,
using a new intervention or implant, or testing a new rehabilitation
protocol. This article provides an overview of some of the clinically-validated
performance-based functional outcome tools used in the assessment
of patients undergoing hip and knee surgery. Cite this article:
Total knee replacement (TKR) smart tibial trials
have load-bearing sensors which will show quantitative compartment
pressure values and femoral-tibial tracking patterns. Without smart
trials, surgeons rely on feel and visual estimation of imbalance
to determine if the knee is optimally balanced. Corrective soft-tissue
releases are performed with minimal feedback as to what and how
much should be released. The smart tibial trials demonstrate graphically
where and how much imbalance is present, so that incremental releases
can be performed. The smart tibial trials now also incorporate accelerometers
which demonstrate the axial alignment. This now allows the surgeon
the option to perform a slight recut of the tibia or femur to provide
soft-tissue balance without performing soft-tissue releases. Using
a smart tibial trial to assist with soft-tissue releases or bone
re-cuts, improved patient outcomes have been demonstrated at one
year in a multicentre study of 135 patients (135 knees). Cite this article:
At least four ways have been described to determine
femoral component rotation, and three ways to determine tibial component
rotation in total knee replacement (TKR). Each method has its advocates
and each has an influence on knee kinematics and the ultimate short
and long term success of TKR. Of the four femoral component methods,
the author prefers rotating the femoral component in flexion to
that amount that establishes a stable symmetrical flexion gap. This
judgement is made after the soft tissues of the knee have been balanced
in extension. Of the three tibial component methods, the author prefers rotating
the tibial component into congruency with the established femoral
component rotation with the knee is in extension. This yields a
rotationally congruent articulation during weight-bearing and should
minimise the torsional forces being transferred through a conforming tibial
insert, which could lead to wear to the underside of the tibial
polyethylene. Rotating platform components will compensate for any
mal-rotation, but can still lead to pain if excessive tibial insert
rotation causes soft-tissue impingement. Cite this article:
Bone loss in the proximal tibia and distal femur
is frequently encountered in revision knee replacement surgery.
The various options for dealing with this depend on the extent of
any bone loss. We present our results with the use of cementless
metaphyseal metal sleeves in 103 patients (104 knees) with a mean
follow-up of 43 months (30 to 65). At final follow-up, sleeves in
102 knees had good osseointegration. Two tibial sleeves were revised
for loosening, possibly due to infection. The average pre-operative Oxford Knee Score was 23 (11 to 36)
and this improved to 32 (15 to 46) post-operatively. These early
results encourage us to continue with the technique and monitor
the outcomes in the long term. Cite this article:
Patient-specific cutting guides (PSCGs) are designed
to improve the accuracy of alignment of total knee replacement (TKR).
We compared the accuracy of limb alignment and component positioning
after TKR performed using PSCGs or conventional instrumentation.
A total of 80 patients were randomised to undergo TKR with either of
the different forms of instrumentation, and radiological outcomes
and peri-operative factors such as operating time were assessed.
No significant difference was observed between the groups in terms
of tibiofemoral angle or femoral component alignment. Although the
tibial component in the PSCGs group was measurably closer to neutral
alignment than in the conventional group, the size of the difference
was very small (89.8° ( Cite this article:
Substantial healthcare resources have been devoted
to computer navigation and patient-specific instrumentation systems
that improve the reproducibility with which neutral mechanical alignment
can be achieved following total knee replacement (TKR). This choice of
alignment is based on the long-held tenet that the alignment of
the limb post-operatively should be within 3° of a neutral mechanical
axis. Several recent studies have demonstrated no significant difference
in survivorship when comparing well aligned Review of the literature suggests that a neutral mechanical axis
remains the optimal guide to alignment. Cite this article:
We are entering a new era with governmental bodies
taking an increasingly guiding role, gaining control of registries,
demanding direct access with release of open public information
for quality comparisons between hospitals. This review is written
by physicians and scientists who have worked with the Swedish Knee
Arthroplasty Register (SKAR) periodically since it began. It reviews
the history of the register and describes the methods used and lessons
learned. Cite this article:
The optimum cementing technique for the tibial
component in cemented primary total knee replacement (TKR) remains
controversial. The technique of cementing, the volume of cement
and the penetration are largely dependent on the operator, and hence
large variations can occur. Clinical, experimental and computational
studies have been performed, with conflicting results. Early implant
migration is an indication of loosening. Aseptic loosening is the
most common cause of failure in primary TKR and is the product of
several factors. Sufficient penetration of cement has been shown
to increase implant stability. This review discusses the relevant literature regarding all aspects
of the cementing of the tibial component at primary TKR. 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
Smart trials are total knee tibial trial liners
with load bearing and alignment sensors that will graphically show quantitative
compartment load-bearing forces and component track patterns. These
values will demonstrate asymmetrical ligament balancing and misalignments
with the medial retinaculum temporarily closed. Currently surgeons
use feel and visual estimation of imbalance to assess soft-tissue
balancing and tracking with the medial retinaculum open, which results
in lower medial compartment loads and a wider anteroposterior tibial
tracking pattern. The sensor trial will aid the total knee replacement
surgeon in performing soft-tissue balancing by providing quantitative
visual feedback of changes in forces while performing the releases
incrementally. Initial experience using a smart tibial trial is
presented.
Blood loss during total knee replacement (TKR)
remains a significant concern. In this study, 114 patients underwent TKR,
and were divided into two groups based on whether they received
a new generation fibrin sealant intra-operatively, or a local infiltration
containing adrenaline. Groups were then compared for mean calculated
total blood volume (TBV) loss, transfusion rates, and knee range
of movement. Mean TBV loss was similar between groups: fibrin sealant
mean was 705 ml (281 to 1744), local adrenaline mean was 712 ml
(261 to 2308) (p = 0.929). Overall, significantly fewer units of
blood were transfused in the fibrin sealant group (seven units)
compared with the local adrenaline group (15 units) (p = 0.0479).
Per patient transfused, significantly fewer units of blood were transfused
in the fibrin sealant group (1.0 units) compared with the local
adrenaline group (1.67 units) (p = 0.027), suggesting that the fibrin
sealant may reduce the need for multiple unit transfusions. Knee
range of movement was similar between groups. From our results,
it appears that application of this newer fibrin sealant results
in blood loss and transfusion rates that are low and similar to
previously applied fibrin sealants. Cite this article:
A total of 445 consecutive primary total knee
replacements (TKRs) were followed up prospectively at six and 18 months
and three, six and nine years. Patients were divided into two groups:
non-obese (body mass index (BMI) <
30 kg/m2) and obese
(BMI ≥ 30 kg/m2). The obese group was subdivided into
mildly obese (BMI 30 to 35 kg/m2) and highly obese (BMI ≥ 35
kg/m2) in order to determine the effects of increasing
obesity on outcome. The clinical data analysed included the Knee
Society score, peri-operative complications and implant survival.
There was no difference in the overall complication rates or implant
survival between the two groups. Obesity appears to have a small but significant adverse effect
on clinical outcome, with highly obese patients showing lower function
scores than non-obese patients. However, significant improvements
in outcome are sustained in all groups nine years after TKR. Given
the substantial, sustainable relief of symptoms after TKR and the low
peri-operative complication and revision rates in these two groups,
we have found no reason to limit access to TKR in obese patients.
We aimed to obtain anthropometric data on Korean
knees and to compare these with data on commonly available total
knee arthroplasties (TKAs). The dimensions of the femora and tibiae
of 1168 knees were measured intra-operatively. The femoral components
were found to show a tendency toward mediolateral (ML) under-coverage
in small femurs and ML overhang in the large femurs. The ML under-coverage
was most prominent for the small prostheses. The ML/anteroposterior
(ML/AP) ratio of Korean tibiae was greater than that of tibial components. This study shows that, for different reasons, current TKAs do
not provide a reasonable fit for small or large Korean knees, and
that the ‘gender-specific’ and ‘stature-specific’ components help
for large Korean femurs but offer less satisfactory fits for small
femurs. Specific modifications of prostheses are needed for Asian
knees.
We prospectively followed 171 patients who underwent
bilateral unicompartmental knee replacement (UKR) over a period
of two years. Of these, 124 (72.5%) underwent a simultaneous bilateral
procedure and 47 (27.5%) underwent a staged procedure. The mean
cumulative operating time and length of hospital stay were both
shorter in the simultaneous group, by 22.5 minutes (p <
0.001)
and three days (p <
0.001), respectively. The mean reduction
in haemoglobin level post-operatively was greater by 0.15 g/dl in
the simultaneous group (p = 0.023), but this did not translate into
a significant increase in the number of patients requiring blood
transfusion (p = 1.000). The mean hospital cost was lower by $8892
in the simultaneous group (p <
0.001). There was no significant
difference in the rate of complications between the groups, and
at two-year follow-up there was no difference in the outcomes between
the two groups. We conclude that simultaneous bilateral UKR can be recommended
as an appropriate treatment for patients with bilateral medial compartment
osteoarthritis of the knee. Cite this article:
Medial patellofemoral ligament (MPFL) reconstruction
is used to treat patellar instability and recurrent patellar dislocation.
Anatomical studies have found the MPFL to be a double-bundle structure.
We carried out a meta-analysis of studies reporting outcomes of
patellofemoral reconstruction using hamstring tendon autograft in
a double-bundle configuration and patellar fixation via mediolateral
patellar tunnels. A literature search was undertaken with no language restriction
in various databases from their year of inception to July 2012.
The primary outcome examined was the post-operative Kujala score.
We identified 320 MPFL reconstructions in nine relevant articles.
The combined mean post-operative Kujala score was 92.02 (standard
error ( Cite this article:
There are several methods for evaluating stability
of the joint during total knee replacement (TKR). Activities of daily
living demand mechanical loading to the knee joint, not only in
full extension, but also in mid-flexion. The purpose of this study
was to compare the varus-valgus stability throughout flexion in
knees treated with either cruciate-retaining or posterior-stabilised
TKR, using an intra-operative navigation technique. A total of 34
knees underwent TKR with computer navigation, during which the investigator
applied a maximum varus-valgus stress to the knee while steadily
moving the leg from full extension to flexion both before and after
prosthetic implantation. The femorotibial angle was measured simultaneously
by the navigation system at every 10° throughout the range of movement.
It was found that posterior-stabilised knees had more varus-valgus
laxity than cruciate-retaining knees at all angles examined, and
the differences were statistically significant at 10° (p = 0.0093),
20° (p = 0.0098) and 30° of flexion (p = 0.0252). Cite this article:
We examined the association of graft type with
the risk of early revision of primary anterior cruciate ligament reconstruction
(ACLR) in a community-based sample. A retrospective analysis of
a cohort of 9817 ACLRs recorded in an ACLR Registry was performed.
Patients were included if they underwent primary ACLR with bone–patellar tendon–bone
autograft, hamstring tendon autograft or allograft tissue. Aseptic
failure was the main endpoint of the study. After adjusting for
age, gender, ethnicity, and body mass index, allografts had a
3.02 times (95% confidence interval (CI) 1.93 to 4.72) higher risk
of aseptic revision than bone–patellar tendon–bone autografts (p
<
0.001). Hamstring tendon autografts had a 1.82 times (95% CI
1.10 to 3.00) higher risk of revision compared with bone–patellar
tendon–bone autografts (p = 0.019). For each year increase in age,
the risk of revision decreased by 7% (95% CI 5 to 9). In gender-specific
analyses a 2.26 times (95% CI 1.15 to 4.44) increased risk of hamstring
tendon autograft revision in females was observed compared with
bone–patellar tendon–bone autograft. We conclude that allograft
tissue, hamstring tendon autografts, and younger age may all increase
the risk of early revision surgery after ACLR. Cite this article:
We investigated whether an asymmetric extension
gap seen on routine post-operative radiographs after primary total
knee replacement (TKR) is associated with pain at three, six, 12
and 24 months’ follow-up. On radiographs of 277 patients after primary
TKR we measured the distance between the tibial tray and the femoral
condyle on both the medial and lateral sides. A difference was defined
as an asymmetric extension gap. We considered three groups (no asymmetric
gap, medial-opening and lateral-opening gap) and calculated the
associations with the Western Ontario and McMaster Universities
osteoarthritis index pain scores over time. Those with an asymmetric extension gap of ≥ 1.5 mm had a significant
association with pain scores at three months’ follow-up; patients
with a medial-opening extension gap reported more pain and patients
with a lateral-opening extension gap reported less pain (p = 0.036).
This effect was still significant at six months (p = 0.044), but had
lost significance by 12 months (p = 0.924). When adjusting for multiple
cofounders the improvement in pain was more pronounced in patients
with a lateral-opening extension gap than in those with a medial-opening extension
gap at three (p = 0.037) and six months’ (p = 0.027) follow-up. Cite this article:
Ensuring correct rotation of the femoral component
is a challenging aspect of patellofemoral replacement surgery. Rotation
equal to the epicondylar axis or marginally more external rotation
is acceptable. Internal rotation is associated with poor outcomes.
This paper comprises two studies evaluating the use of the medial
malleolus as a landmark to guide rotation. We used 100 lower-leg anteroposterior radiographs to evaluate
the reliability of the medial malleolus as a landmark. Assessment
was made of the angle between the tibial shaft and a line from the
intramedullary rod entry site to the medial malleolus. The femoral
cut was made in ten cadaver knees using the inferior tip of the
medial malleolus as a landmark for rotation. Rotation of the cut
relative to the anatomical epicondylar axis was assessed using CT.
The study of radiographs found the position of the medial malleolus
relative to the tibial axis is consistent. Using the inferior tip
of the medial malleolus in the cadaver study produced a mean external
rotation of 1.6° (0.1° to 3.7°) from the anatomical epicondylar
axis. Using the inferior tip of the medial malleolus to guide the
femoral cutting jig avoids internal rotation and introduces an acceptable
amount of external rotation of the femoral component.
Hypermobility is an acknowledged risk factor
for patellar instability. In this case control study the influence
of hypermobility on clinical outcome following medial patellofemoral
ligament (MPFL) reconstruction for patellar instability was studied. A total of 25 patients with hypermobility as determined by the
Beighton criteria were assessed and compared with a control group
of 50 patients who were matched for age, gender, indication for
surgery and degree of trochlear dysplasia. The patients with hypermobility
had a Beighton Score of ≥ 6; the control patients had a score of <
4. All patients underwent MPFL reconstruction performed using semitendinosus
autograft and a standardised arthroscopically controlled technique.
The mean age of the patients was 25 years (17 to 49) and the mean
follow-up was 15 months (6 to 30). Patients with hypermobility had a significant improvement in
function following surgery, with reasonable rates of satisfaction,
perceived improvement, willingness to repeat and likelihood of recommendation.
Functional improvements were significantly less than in control
patients (p <
0.01). Joint hypermobility is not a contraindication to MPFL reconstruction
although caution is recommended in managing the expectations of
patients with hypermobility before consideration of surgery.
Our aim was to assess the use of intra-operative fluoroscopy
in the assessment of the position of the tibial tunnel during reconstruction
of the anterior cruciate ligament (ACL). Between January and June 2009 a total of 31 arthroscopic hamstring
ACL reconstructions were performed. Intra-operative fluoroscopy
was introduced (when available) to verify the position of the guidewire
before tunnel reaming. It was only available for use in 20 cases,
due to other demands on the radiology department. The tourniquet
times were compared between the two groups and all cases where radiological
images lead to re-positioning of the guide wire were recorded. The
secondary outcome involved assessing the tibial interference screw
position measured on post-operative radiographs and comparing with
the known tunnel position as shown on intra-operative fluoroscopic
images.Objectives
Methods
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.
In this paper, we consider wound healing after
total knee arthroplasty.
To assess the effectiveness of a modified tibial tubercle osteotomy
as a treatment for arthroscopically diagnosed chondromalacia patellae. A total of 47 consecutive patients (51 knees) with arthroscopically
proven chondromalacia, who had failed conservative management, underwent
a modified Fulkerson tibial tubercle osteotomy. The mean age was
34.4 years (19.6 to 52.2). Pre-operatively, none of the patients
exhibited signs of patellar maltracking or instability in association
with their anterior knee pain. The minimum follow-up for the study
was five years (mean 72.6 months (62 to 118)), with only one patient
lost to follow-up.Objectives
Methods
Peri-prosthetic patellar fracture following resurfacing
as part of total knee replacement (TKR) is an infrequent yet challenging
complication. This case-control study was performed to identify
clinical, radiological and surgical factors that increase the risk
of developing a spontaneous patellar fracture after TKR. Patellar
fractures were identified in 74 patients (88 knees) from a series
of 7866 consecutive TKRs conducted between 1998 and 2009. After excluding
those with a previous history of extensor mechanism realignment
or a clear traumatic event, a metal-backed patella, any uncemented
component or subsequent infection, the remaining 64 fractures were
compared with a matched group of TKRs with an excellent outcome
defined by the Knee Society score. The mean age of patients with
a fracture was 70 years (51 to 81) at the time of TKR. Patellar
fractures were detected at a mean of 13.4 months (2 to 84) after
surgery. The incidence of patellar fracture was found to be strongly
associated with the number of previous knee operations, greater
pre-operative mechanical malalignment, smaller post-operative patellar
tendon length, thinner post-resection patellar thickness, and a
lower post-operative Insall-Salvati ratio. An understanding of the risk factors associated with spontaneous
patellar fracture following TKR provides a valuable insight into
prevention of this challenging complication.
This prospective study compares the outcome of
157 hydroxyapatite (HA)-coated tibial components with 164 cemented
components in the ROCC Rotating Platform total knee replacement
in 291 patients. The mean follow-up was 7.6 years (5.2 to 11). There
were two revisions for loosening: one for an HA-coated and one for
a cemented tibial component. Radiological evaluation demonstrated
no radiolucent lines with the HA-coated femoral components. A total
of three HA-coated tibial components exhibited radiolucent lines
at three months post-operatively and these disappeared after three
further months of protected weight-bearing. With HA-coated components
the operating time was shorter (p <
0.006) and the radiological
assessment of the tibial interface was more stable (p <
0.01).
Using revision for aseptic loosening of the tibial component as
the end point, the survival rates at nine years was identical for
both groups at 99.1%. Our results suggest that HA-coated components perform at least
as well as the same design with cemented components and compare
favourably with those of series describing cemented or porous-coated
knee replacements, suggesting that fixation of both components with
hydroxyapatite is a reliable option in primary total knee replacement.
Seligman’s theory of causal attribution predicts that patients with a pessimistic explanatory style will have less favourable health outcomes. We identified 702 patients who had undergone 894 primary total knee replacements between 1993 and 2005, who responded to follow-up surveys at two (n = 783 knee replacements) and/or five years (n = 443 knee replacements) and had also completed the Minnesota Multiphasic Personality Inventory long before the joint replacement (median = 16.6 and 14.5 years for two- and five-year cohorts, respectively). Scores from the Minnesota Multiphasic Personality Inventory Optimism-Pessimism scale were used to categorise patients as pessimistic (t-score >
60) or non-pessimistic (t-score ≤ 60). Multivariate logistic regression models assessing the effect of pessimistic explanatory style on pain or improvement in knee function were adjusted for gender, age, distance from the place of treatment and depression score. Pessimists reported (a) significantly more moderate or severe pain at two years with odds ratio 2.21 (95% confidence interval (CI) 1.12 to 4.35; p = 0.02), but not at five years when the odds ratio was 1.21 (95% CI 0.51 to 2.83; p = 0.67); and (b) less improvement in knee function at two years when the odds ratio was 0.53 (95% CI 0.30 to 0.96; p = 0.04), but not at five years when the odds ratio was 1.26 (95% CI 0.57 to 2.77; p = 0.57). No significant associations with moderate or severe limitation of activity were seen at two or five years. We conclude that a pessimistic explanatory style is associated with worse pain and functional outcomes two years after total knee replacement.
It is unclear whether there is a limit to the amount of distal bone required to support fixation of supracondylar periprosthetic femoral fractures. This retrospective multicentre study evaluated lateral locked plating of periprosthetic supracondylar femoral fractures and compared the results according to extension of the fracture distal with the proximal border of the femoral prosthetic component. Between 1999 and 2008, 89 patients underwent lateral locked plating of a supracondylar periprosthetic femoral fracture, of whom 61 patients with a mean age of 72 years (42 to 96) comprising 53 women, were available after a minimum follow-up of six months or until fracture healing. Patients were grouped into those with fractures located proximally (28) and those with fractures that extended distal to the proximal border of the femoral component (33). Delayed healing and nonunion occurred respectively in five (18%) and three (11%) of more proximal fractures, and in two (6%) and five (15%) of the fractures with distal extension (p = 0.23 for delayed healing; p = 0.72 for nonunion, Fisher’s exact test). Four construct failures (14%) occurred in more proximal fractures, and three (9%) in fractures with distal extension (p = 0.51). Of the two deep infections that occurred in each group, one resolved after surgical debridement and antibiotics, and one progressed to a nonunion. Extreme distal periprosthetic supracondylar fractures of the femur are not a contra-indication to lateral locked plating. These fractures can be managed with internal fixation, with predictable results, similar to those seen in more proximal fractures.
We assessed hyperextension of the knee and joint laxity in 169 consecutive patients who underwent an anterior cruciate ligament reconstruction between 2000 and 2002 and correlated this with a selected number of age- and gender-matched controls. In addition, the mechanism of injury in the majority of patients was documented. Joint laxity was present in 42.6% (72 of 169) of the patients and hyperextension of the knee in 78.7% (133 of 169). All patients with joint laxity had hyperextension of their knee. In the control group only 21.5% (14 of 65) had joint laxity and 37% (24 of 65) had hyperextension of the knee. Statistical analysis showed a significant correlation for these associations. We conclude that anterior cruciate ligament injury is more common in those with joint laxity and particularly so for those with hyperextension of the knee.
