Aims. The aim of this study was to describe the prevalence and patterns of neuropathic pain over one year in a cohort of patients with chronic post-surgical pain at three months following total knee arthroplasty (TKA). Methods. Between 2016 and 2019, 363 patients with troublesome pain, defined as a score of ≤ 14 on the Oxford Knee Score pain subscale, three months after TKA from eight UK NHS hospitals, were recruited into the Support and Treatment After Replacement (STAR) clinical trial. Self-reported neuropathic pain and postoperative pain was assessed at three, nine, and 15 months after surgery using the painDETECT and Douleur Neuropathique 4 (DN4) questionnaires collected by postal survey. Results. Symptoms of neuropathic pain were common among patients reporting chronic pain at three months post-TKA, with half reporting neuropathic pain on painDETECT (191/363; 53%) and 74% (267/359) on DN4. Of those with neuropathic pain at three months, half continued to have symptoms over the next 12 months (148/262; 56%), one-quarter had improved (67/262; 26%), and for one-tenth their neuropathic symptoms fluctuated over time (24/262; 9%). However, a subgroup of participants reported new, late onset neuropathic symptoms (23/262; 9%). Prevalence of neuropathic symptoms was similar between the screening tools when the lower cut-off painDETECT score (≥ 13) was applied. Overall, mean neuropathic pain scores improved between three and 15 months after TKA. Conclusion. Neuropathic pain is common in patients with chronic pain at three months after TKA. Although neuropathic symptoms improved over time, up to half continued to report painful neuropathic symptoms at 15 months after TKA. Postoperative care should include screening, assessment, and treatment of neuropathic pain in patients with early chronic postoperative pain after TKA. Cite this article: Bone Joint J 2024;106-B(6):582–588

Abstract. Background. Autologous chondrocyte implantation is a NICE approved intervention however it involves the morbidity of two operations, a prolonged rehabilitation and substantial healthcare costs. This study describes a novel, one-step, bone marrow (BM) derived mesenchymal stem cell (MSC) transplantation technique for treating knee osteochondral lesions and presents our prospective clinical study investigating the success of this technique in 206 lesions over a 5 year period. Methodology. The surgical technique involves harvesting BM from patients’ anterior superior iliac spines, centrifugation to isolate MSCs and seeding into a type 1 collagen scaffold (SyngenitTM Biomatrix). Autologous fibrin glue is used to secure the scaffold into the defect. Inclusion criteria included patients aged 15 – 55 years old with symptomatic osteochondral lesions >1cm2. Exclusion criteria included patients with ligament instability, uncorrected alignment, inflammatory arthropathy and a Body Mass Index >35 kg/m2. Outcome measures included the Modified Cincinnati Knee Rating System (MCKRS), complications and reoperations. Results. Mean MCKR scores showed statistically significant improvements compared to pre-operative scores at 6 months 58.79 ± 3.5 and 1 year postoperatively 63.82 ± 3.93 with further improvements at 2 years and 5 years which did not reach statistical significance. Survival rates were 97.9%, 94% and 93.2% at 1, 2 and 5 years. Multiple regression analysis identified previous cartilage surgery, microfracture and age as factors affecting MCKRS scores (p < 0.029, 0.001 and 0.030, respectively). Conclusions. One-step BM derived stem cell transplantation demonstrates satisfactory outcomes over a 5 year period

Aims. A pragmatic, single-centre, double-blind randomized clinical trial was conducted in a NHS teaching hospital to evaluate whether there is a difference in functional knee scores, quality-of-life outcome assessments, and complications at one-year after intervention between total knee arthroplasty (TKA) and patellofemoral arthroplasty (PFA) in patients with severe isolated patellofemoral arthritis. Methods. This parallel, two-arm, superiority trial was powered at 80%, and involved 64 patients with severe isolated patellofemoral arthritis. The primary outcome measure was the functional section of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 months. Secondary outcomes were the full 24-item WOMAC, Oxford Knee Score (OKS), American Knee Society Score (AKSS), EuroQol five dimension (EQ-5D) quality-of-life score, the University of California, Los Angeles (UCLA) Physical Activity Rating Scale, and complication rates collected at three, six, and 12 months. For longer-term follow-up, OKS, EQ-5D, and self-reported satisfaction score were collected at 24 and 60 months. Results. Among 64 patients who were randomized, five patients did not receive the allocated intervention, three withdrew, and one declined the intervention. There were no statistically significant differences in the patients’ WOMAC function score at 12 months (adjusted mean difference, -1.2 (95% confidence interval -9.19 to 6.80); p = 0.765). There were no clinically significant differences in the secondary outcomes. Complication rates were comparable (superficial surgical site infections, four in the PFA group versus five in the TKA group). There were no statistically significant differences in the patients’ OKS score at 24 and 60 months or self-reported satisfaction score or pain-free years. Conclusion. Among patients with severe isolated patellofemoral arthritis, this study found similar functional outcome at 12 months and mid-term in the use of PFA compared with TKA. Cite this article: Bone Joint J 2020;102-B(3):310–318

Aims. Modern total knee arthroplasty (TKA) prostheses are designed to restore near normal kinematics including high flexion. Kneeling is a high flexion, kinematically demanding activity after TKA. The debate about design choice has not yet been informed by six-degrees-of-freedom in vivo kinematics. This prospective randomized clinical trial compared kneeling kinematics in three TKA designs. Methods. In total, 68 patients were randomized to either a posterior stabilized (PS-FB), cruciate-retaining (CR-FB), or rotating platform (CR-RP) design. Of these patients, 64 completed a minimum one year follow-up. Patients completed full-flexion kneeling while being imaged using single-plane fluoroscopy. Kinematics were calculated by registering the 3D implant models onto 2D-dynamic fluoroscopic images and exported for analysis. Results. CR-FB designs had significantly lower maximal flexion (mean 116° (SD 2.1°)) compared to CR-RP (123° (SD 1.6°)) and PS-FB (125° (SD 2.1°)). The PS-FB design displayed a more posteriorly positioned femur throughout flexion. Furthermore, the CR-RP femur was more externally rotated throughout kneeling. Finally, individual patient kinematics showed high degrees of variability within all designs. Conclusion. The increased maximal flexion found in the PS-FB and CR-RP designs were likely achieved in different ways. The PS-FB design uses a cam-post to hold the femur more posteriorly preventing posterior impingement. The external rotation within the CR-RP design was surprising and hasn’t previously been reported. It is likely due to the polyethylene bearing being decoupled from flexion. The findings of this study provide insights into the function of different knee arthroplasty designs in the context during deep kneeling and provide clinicians with a more kinematically informed choice for implant selection and may allow improved management of patients' functional expectations. Cite this article: Bone Joint J 2021;103-B(1):105–112

Aims. Tranexamic acid (TXA) is proven to reduce blood loss following total knee arthroplasty (TKA), but there are limited data on the impact of similar dosing regimens in revision TKA. The purpose of this multicentre randomized clinical trial was to determine the optimal regimen to maximize the blood-sparing properties of TXA in revision TKA. Patients and Methods. From six-centres, 233 revision TKAs were randomized to one of four regimens: 1 g of intravenous (IV) TXA given prior to the skin incision, a double-dose regimen of 1 g IV TXA given both prior to skin incision and at time of wound closure, a combination of 1 g IV TXA given prior to skin incision and 1 g of intraoperative topical TXA, or three doses of 1950 mg oral TXA given two hours preoperatively, six hours postoperatively, and on the morning of postoperative day one. Randomization was performed based on the type of revision procedure to ensure equivalent distribution among groups. Power analysis determined that 40 patients per group were necessary to identify a 1 g/dl difference in the reduction of haemoglobin postoperatively between groups with an alpha of 0.05 and power of 0.80. Per-protocol analysis involved regression analysis and two one-sided t-tests for equivalence. Results. In total, one patient withdrew, five did not undergo surgery, 16 were screening failures, and 25 did not receive the assigned treatment, leaving 186 patients for analysis. There was no significant difference in haemoglobin reduction among treatments (2.8 g/dl for single-dose IV TXA, 2.6 g/dl for double-dose IV TXA, 2.6 g/dl for combined IV/topical TXA, 2.9 g/dl for oral TXA; p = 0.38). Similarly, calculated blood loss (p = 0.65) and transfusion rates (p = 0.95) were not significantly different between groups. Equivalence testing assuming a 1 g/dl difference in haemoglobin change as clinically relevant showed that all possible pairings were statistically equivalent. Conclusion. Despite the higher risk of blood loss in revision TKA, all TXA regimens tested had equivalent blood-sparing properties. Surgeons should consider using the lowest effective dose and least costly TXA regimen in revision TKA. Cite this article: Bone Joint J 2019;101-B(Supple 7):10–16

Background. The purpose of this multi-center, randomized clinical trial was to compare static and articulating spacers in the treatment of PJI complicating total knee arthroplasty TKA. Methods. 68 Patients treated with two-stage exchange arthroplasty were randomized to either a static (32 patients) or an articulating (36 patients) spacer. A power analysis determined that 28 patients per group were necessary to detect a 13º difference in range of motion between groups. Six patients were excluded after randomization, six died, and seven were lost to follow-up prior to two years. Results. Patients in the static group had a hospital length of stay that was one day greater than the articulating group (6.1 vs. 5.1 days; p=0.032); no other differences were noted perioperatively. At a mean 3.5 years (range, 2.0 to 6.4 years), 49 patients were available for evaluation. Mean motion arc in the articulating group was 113.0º compared to 100.2º in the static group (p=0.001). The mean Knee Society Score was significantly higher in the articulating cohort (79.4 vs. 69.8 points; p=0.043). Although not significantly different with the sample size studied, static spacers were associated with a greater need for an extensile exposure at the time of reimplantation (16.7% vs. 3.8%) and a higher rate of reoperation (33.3% vs. 12.0%). Conclusions. Articulating spacers provided significantly greater range of motion and better clinical outcomes scores. Static spacers also appeared to affect early postoperative rehabilitation, as evidenced by a longer hospital stay following removal of the infected implant and were associated with a trend towards a greater need for extensile exposures at the time of reimplantation. Further, while it has been commonly believed that static spacers would improve infection control, there was no difference in the failure rate secondary to reinfection and there was a trend towards higher risk of reoperation in patients who received a static spacer. When the soft tissue envelope allows and if there is adequate bony support, an articulating spacer is associated with improved outcomes. For figures, tables, or references, please contact authors directly

Introduction

Tranexamic acid (TXA) is proven to reduce blood loss following total knee arthroplasty (TKA), but there are limited data on the impact of similar dosing regimens in revision TKA that is associated with greater blood loss. The purpose of this multi-center randomized trial was to determine the optimal regimen to maximize the blood-sparing properties of TXA in revision TKA.

Introduction

The application of artificial intelligence (A.I) using patient reported outcomes (PROs) to predict benefits, risks, benefits and likelihood of improvement following surgery presents a new frontier in shared decision-making. The purpose of this study was to assess the impact of an A.I-enabled decision aid versus patient education alone on decision quality in patients with knee OA considering total knee replacement (TKR). Secondarily we assess impact on shared decision-making, patient satisfaction, functional outcomes, consultation time, TKR rates and treatment concordance.

Abstract. Introduction. Anterior cruciate ligament reconstruction (ACLR) can be performed with a number of different autografts including all soft tissue quadriceps autograft. (QT). QT has several advantages including decreased donor site morbidity, reduced anterior knee pain and comparable revision rates compared to other autografts. The primary aim of this review was to assess all complications of QT in adult population. Methodology. A systematic review of the literature was conducted on in accordance with the PRISMA guidelines using the online databases Medline and EMBASE. Clinical studies or reporting on soft tissue QT were included and appraised using the Methodological Index for Non-Randomized Studies (MINORS) tool. Results. Twelve studies were eligible, giving a total of 774 cases of QT ACLR. The mean age ranged from 18 to 45 years. The mean follow-up ranged from 12 to 55.6 months. Nine studies report on patients’ functional outcomes with mean IKDC score was 90.9 ±22.6 and Lysholm score of 88.6 ±6.5. Seven studies reported on complications which was overall 12.3% including 4.1% for graft site morbidity. Infection was reported in 0.4% of the patients. Seven studies reported on failure rate which was reported in 5.3%. Re-operation rate for any reason was 3.2 %. Conclusion. All soft tissue QT for ACLR has a low complication rate and revision rate. There is less graft site morbidity

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

Aims. Total knee arthroplasty (TKA) using functional alignment aims to implant the components with minimal compromise of the soft-tissue envelope by restoring the plane and obliquity of the non-arthritic joint. The objective of this study was to determine the effect of TKA with functional alignment on mediolateral soft-tissue balance as assessed using intraoperative sensor-guided technology. Methods. This prospective study included 30 consecutive patients undergoing robotic-assisted TKA using the Stryker PS Triathlon implant with functional alignment. Intraoperative soft-tissue balance was assessed using sensor-guided technology after definitive component implantation; soft-tissue balance was defined as intercompartmental pressure difference (ICPD) of < 15 psi. Medial and lateral compartment pressures were recorded at 10°, 45°, and 90° of knee flexion. This study included 18 females (60%) and 12 males (40%) with a mean age of 65.2 years (SD 9.3). Mean preoperative hip-knee-ankle deformity was 6.3° varus (SD 2.7°). Results. TKA with functional alignment achieved balanced medial and lateral compartment pressures at 10° (25.0 psi (SD 6.1) vs 23.1 psi (SD 6.7), respectively; p = 0.140), 45° (21.4 psi (SD 5.9) vs 20.6 psi (SD 5.9), respectively; p = 0.510), and 90° (21.2 psi (SD 7.1) vs 21.6 psi (SD 9.0), respectively; p = 0.800) of knee flexion. Mean ICPD was 6.1 psi (SD 4.5; 0 to 14) at 10°, 5.4 psi (SD 3.9; 0 to 12) at 45°, and 4.9 psi (SD 4.45; 0 to 15) at 90° of knee flexion. Mean postoperative limb alignment was 2.2° varus (SD 1.0°). Conclusion. TKA using the functional alignment achieves balanced mediolateral soft-tissue tension through the arc of knee flexion as assessed using intraoperative pressure-sensor technology. Further clinical trials are required to determine if TKA with functional alignment translates to improvements in patient satisfaction and outcomes compared to conventional alignment techniques. Cite this article: Bone Joint J 2021;103-B(3):507–514

Aims. The aim is to assess the cost-effectiveness of patellofemoral arthroplasty (PFA) in comparison with total knee arthroplasty (TKA) for the treatment of isolated patellofemoral osteoarthritis (OA) based on prospectively collected data on health outcomes and resource use from a blinded, randomized, clinical trial. Methods. A total of 100 patients with isolated patellofemoral osteoarthritis were randomized to receive either PFA or TKA by experienced knee surgeons trained in using both implants. Patients completed patient-reported outcomes including EuroQol five-dimension questionnaire (EQ-5D) and 6-Item Short-Form Health Survey questionnaire (SF-6D) before the procedure. The scores were completed again after six weeks, three, six, and nine months, and again after one- and two-year post-surgery and yearly henceforth. Time-weighted outcome measures were constructed. Cost data were obtained from clinical registrations and patient-reported questionnaires. Incremental gain in health outcomes (quality-adjusted life-years (QALYs)) and incremental costs were compared for the two groups of patients. Net monetary benefit was calculated assuming a threshold value of €10,000, €35,000, and €50,000 per QALY and used to test the statistical uncertainty and central assumptions about outcomes and costs. Results. The PFA group had an incremental 12 month EQ-5D gain of 0.056 (95% confidence interval (CI) 0.01 to 0.10) and an incremental 12 month cost of minus €328 (95% CI 836 to 180). PFA therefore dominates TKA by providing better and cheaper outcomes than TKA. The net monetary benefit of PFA was €887 (95% CI 324 to 1450) with the €10,000 threshold, and it was consistently positive when different measures of outcomes and different cost assumptions were used. Conclusion. This study provides robust evidence that PFA from a one-year hospital management perspective is cheaper and provides better outcomes than TKA when applied to patients with isolated patellofemoral osteoarthritis and performed by experienced knee surgeons. Cite this article: Bone Joint J 2020;102-B(4):449–457

Introduction. Active robotics for total knee Arthroplasty (TKA) uses a CAD-CAM approach to plan the correct size and placement of implants and to surgically achieve planned limb alignment. The TSolution One Total Knee Application (THINK Surgical Inc., Fremont, CA) is an open-implant platform, CT-based active robotic surgical system. A multi-center, prospective, non-randomized clinical trial was performed to evaluate the safety and effectiveness of robotic-assisted TKA using the TSolution One Total Knee Application. This report details the findings from the IDE. Methods. Inclusion criteria for patients receiving robotic TKA were: primary unilateral TKA; Kellgren-Lawrence OA grade 3 or 4; BMI < 40 kg/m2; coronal plane deformity < 20° varus; sagittal flexion contracture < 15°. In addition to monitoring all adverse events (AE), a pre-defined list of relevant major AEs were specifically identified to evaluate safety (Healy et al, 2013): medial collateral ligament injury; extensor mechanism disruption; neural deficit; periprosthetic fracture; patellofemoral dislocation; tibiofemoral dislocation; and vascular injury. Bleeding complications were also assessed. Malalignment rate, defined as the percentage of patients with more than a ± 3° difference in varus-valgus alignment from the preoperative plan, was used to determine accuracy of the active robotic system. Knee Society Scores (KSS) and Short Form 12 (SF-12) Health Surveys were assessed as clinical outcome measures. For each outcome, results were compared to published values associated with manual TKA. Results. A total of 115 patients were enrolled at 6 US centers and followed for a maximum of 12 months after surgery. Mean surgical time (incision to close) improved consistently as the technique evolved (first 10 cases = 131.5 min, first 20 cases = 122.4 min), with mean robot time = 45.8 min. The incidence of pre-defined AEs identified was 0%, serving as a measure of safety of the procedure. Outside of the pre-defined list, only one AE was definitely associated with the use of the device; a metal pin was left inside the knee joint but no reoperation was performed. No patients required a blood transfusion. Alignment outside of the ± 3° goal was 11.2% with a difference of 0.5° ± 1.9° (mean ± STD), which represents a 45% statistically significant (posterior probability > 0.95) reduction in malalignment compared to the literature (Mason et al, 2007). Mean KSS Functional scores improved from 40.5 at baseline to 65.3 at 3 months, mean KSS Objective scores improved from 36.8 to 81.0, mean KSS Patient Satisfaction scores improved from 14.4 to 30.6, and mean SF-12 Physical Component scores improved from 32.9 to 43.5. Discussion. The TSolution One Total Knee Application is descended from an active robotic system used in >8000 cases outside the United States since 2002. This trial represents the first US based study of this technology for primary TKA. The clinical study demonstrated positive safety outcomes as none of the seven pre-defined AEs were observed and there were no cases requiring transfusion. A positive effectiveness outcome was also demonstrated as the malalignment rate found in this study showed a substantial reduction from the 32% malalignment rate published in the literature for conventional instruments. KSS and SF-12 scores were comparable to other published TKA series. For figures, tables, or references, please contact authors directly

Aims. 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. Methods. 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. Results. The mean total blood loss was lowest in the no-tourniquet group at 867.32 ml (SD 201.11), increased in the limited-tourniquet group at 1024.35 ml (SD 176.35), and was highest in the tourniquet group at 1,213.00 ml (SD 211.48). The hidden blood loss was lowest in the no-tourniquet group (both p < 0.001). There was less mean intraoperative blood loss in the tourniquet group (77.48 ml (SD 24.82)) than in the limited-tourniquet group (137.04 ml (SD 26.96)) and the no-tourniquet group (212.99 ml (SD 56.35); both p < 0.001). Patients in the tourniquet group showed significantly higher levels of muscle damage and inflammation biomarkers such as CK, CRP, and IL-6 than the other two groups (p < 0.05). Outcomes for VAS pain scores, limb swelling ratio, quadriceps strength, straight leg raising, ROM, and KSS were significantly better in the no-tourniquet group at three weeks postoperatively (p < 0.05), but there were no significant differences at three months. No significant differences were observed among the three groups with respect to transfusion rate, thrombotic events, or the length of hospital stay. Conclusion. Patients who underwent TKA with multiple doses of intravenous tranexamic acid but without a tourniquet presented lower total blood loss and hidden blood loss, and they showed less postoperative inflammation reaction, less muscle damage, lower VAS pain score, and better early knee function. Our results argue for not using a tourniquet during TKA. Cite this article: Bone Joint Res 2020;9(6):322–332

Aims

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.

Aims

Micromotion of the polyethylene (PE) inlay may contribute to backside PE wear in addition to articulate wear of total knee arthroplasty (TKA). Using radiostereometric analysis (RSA) with tantalum beads in the PE inlay, we evaluated PE micromotion and its relationship to PE wear.

Aims

To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration.

Aims

The mid-term results of kinematic alignment (KA) for total knee arthroplasty (TKA) using image derived instrumentation (IDI) have not been reported in detail, and questions remain regarding ligamentous stability and revisions. This paper aims to address the following: 1) what is the distribution of alignment of KA TKAs using IDI; 2) is a TKA alignment category associated with increased risk of failure or poor patient outcomes; 3) does extending limb alignment lead to changes in soft-tissue laxity; and 4) what is the five-year survivorship and outcomes of KA TKA using IDI?

Aims

The aim of this study was to compare the preinjury functional scores with the postinjury preoperative score and postoperative outcome scores following anterior cruciate ligament (ACL) reconstruction surgery (ACLR).

Aims

Implantation of ultra-purified alginate (UPAL) gel is safe and effective in animal osteochondral defect models. This study aimed to examine the applicability of UPAL gel implantation to acellular therapy in humans with cartilage injury.