Computer-assisted surgery and patient-specific instrumentation improve the accuracy of tibial baseplate rotation in total knee arthroplasty compared to conventional instrumentation: a systematic review and meta-analysis.

PURPOSE: To determine whether patient-specific instrumentation (PSI), computer-assisted surgery (CAS) or robot-assisted surgery (RAS) enable more accurate rotational alignment of the tibial baseplate in primary total knee arthroplasty (TKA) compared to conventional instrumentation, in terms of deviation from the planned target and the proportion of outliers from the target zone. METHODS: The authors independently conducted three structured electronic literature searches using the PubMed, Embase®, and Cochrane Central Register of Controlled Trials databases from 2007 to 2020. Studies were included if they compared rotational alignment of the tibial baseplate during TKA using conventional instrumentation versus PSI, CAS, and/or RAS, and reported deviation from preoperatively planned rotational alignment of the tibial baseplate in terms of absolute angles and/or number of outliers. Methodological quality of eligible studies was assessed by two researchers according to the Downs and Black Quality Checklist for Health Care Intervention Studies. RESULTS: Fifteen studies, that reported on 2925 knees, were eligible for this systematic review, of which 6 studies used PSI, and 9 used CAS. No studies were found for RAS. Of the studies that reported on angular deviation from preoperatively planned rotational alignment, most found smaller deviations using PSI (0.5° to 1.4°) compared to conventional instrumentation (1.0° to 1.6°). All studies that reported on proportions of outliers from a target zone (± 3°), found lower rates of outliers using PSI (0 to 22%) compared to conventional instrumentation (5 to 96%). Most studies reported smaller angular deviation from preoperatively planned rotational alignment using CAS (0.1° to 6.9°) compared to conventional instrumentation (1.1° to 7.8°). Of the studies that reported on proportions of outliers from a target zone (± 3°), most found fewer outliers using CAS (10 to 61%) compared to conventional instrumentation (17 to 78%). CONCLUSION: This systematic review and meta-analysis revealed that both CAS and PSI can improve the accuracy of rotational alignment of the tibial baseplate by decreasing angular deviation from the preoperatively planned target and reducing the proportion of outliers from the target zone. The clinical relevance is that PSI and CAS can improve alignment, though the thresholds necessary to grant better outcomes and survival remain unclear. LEVEL OF EVIDENCE: IV.

Patient-specific instruments do not show advantage over conventional instruments in unicompartmental knee arthroplasty at 2 year follow-up: a prospective, two-centre, randomised, double-blind, controlled trial.

PURPOSE: The aim of this two-centre RCT was to compare pre- and post-operative radiological, clinical and functional outcomes between patient-specific instrumentation (PSI) and conventional instrumented (CI) unicompartmental knee arthroplasty (UKA). It was hypothesised that both alignment methods would have comparable post-operative radiological, clinical and functional outcomes. METHODS: One hundred and twenty patients were included, and randomly allocated to the PSI or the CI group. Outcome measures were peri-operative outcomes (operation time, length of hospital stay and intra-operative changes of implant size) and post-operative radiological outcomes including the alignment of the tibial and femoral component in the sagittal and frontal plane and the hip-knee-ankle-axis (HKA-axis), rate of adverse events (AEs) and patient-reported outcome measures (PROMs) pre-operatively and at 3, 12 and 24 months post-operatively. RESULTS: There was a statistically significant difference (p < 0.05) in alignment of the femoral component in the frontal plane in favour of the CI method. No statistically significant differences were found for the peri-operative data or in the functional outcome at 2-year follow-up. In the PSI group, the approved implant size of the femoral component was correct in 98.2% of the cases and the tibial component was correct in 60.7% of the cases. There was a comparable rate of AEs: 5.1% in the CI and 5.4% in the PSI group. CONCLUSION: The PSI method did not show an advantage over CI in regard of positioning of the components, nor did it show an improvement in clinical or functional outcome. We conclude that the possible advantages of PSI do not outweigh the costs of the MRI scan and the manufacturing of the PSI. LEVEL OF EVIDENCE: Randomised controlled trial, level I.

High intra- and inter-observer reliability of planning implant size in MRI-based patient-specific instrumentation for total knee arthroplasty.

PURPOSE: Patient-specific instrumentation (PSI) in total knee arthroplasty (TKA) uses individually designed disposable guides to determine intraoperative bone cuts. The manufacturer provides the surgeon with proposed planning which can be modified and should be approved by the surgeon before the guides are produced. This study aims to assess the intra- and inter-observer reliability among preoperative planning by orthopaedic surgeons using PSI. The authors hypothesize a high intra- and inter-observer reliability in planning TKA using PSI. METHODS: Four orthopaedic surgeons modified and approved 40 preoperative MRI-based PSI plannings three times. The surgeons were blinded to their own and each other's results. Intra- and inter-observer reliability was obtained for planned implant size, resection, and position of the implant. RESULTS: Intra-observer reliability Intraclass Correlation Coefficients (ICC) were excellent for femoral and tibial implant size with a range of 0.948-0.995 and 0.919-0.988, respectively. Inter-observer reliability for femoral and tibial implant size showed an ICC range of 0.953-0.982 and 0.839-0.951, respectively. Next to implant size, intra- and inter-observer reliability demonstrated good to an excellent agreement (ICC > 0.75) for 7 out of 12 remaining parameters and 6 out of 12 remaining parameters, respectively. CONCLUSION: Preoperative planning of TKA implant size using MRI-based PSI showed excellent intra- and inter-observer reliability. Further research on the comparison of predicted implant size preoperatively to intraoperative results is needed.

Preparation for the next COVID-19 wave: The European Hip Society and European Knee Associates recommendations.

PURPOSE: To plan for the continuance of elective hip and knee arthroplasty during a resurgence or new wave of COVID-19 infections. METHOD: A systematic review was conducted using the terms "COVID-19" or "SARS-Cov-2" and "second wave". No relevant citations were found to inform on recommendations the plan. Therefore, an expert panel of the European Hip Society and the European Knee Associates was formed to provide the recommendations. RESULTS: Overall, the recommendations consider three phases; review of the first wave, preparation for the next wave, and during the next wave. International and national policies will drive most of the management. The recommendations focus on the preparation phase and, in particular, the actions that the individual surgeon needs to undertake to continue with, and practice, elective arthroplasty during the next wave, as well as planning their personal and their family's lives. The recommendations expect rigorous data collection during the next wave, so that a cycle of continuous improvement is created to take account of any future waves. CONCLUSIONS: The recommendations for planning to continue elective hip and knee arthroplasty during a new phase of the SARS-Cov-2 pandemic provide a framework to reduce the risk of a complete shutdown of elective surgery. This involves engaging with hospital managers and other specialities in the planning process. Individuals have responsibilities to themselves, their colleagues, and their families, beyond the actual delivery of elective arthroplasty.

Reduced opiate use after total knee arthroplasty using computer-assisted cryotherapy.

PURPOSE: Despite multimodal pain management and advances in anesthetic techniques, total knee arthroplasty (TKA) remains painful during the early postoperative phase. This trial investigated whether computer-assisted cryotherapy (CAC) is effective in reduction of pain and consumption of opioids in patients operated for TKA following an outpatient surgery pathway. METHODS: Sixty patients scheduled for primary TKA were included in this prospective, double-blind, randomized controlled trial receiving CAC at 10-12 °C (Cold-group, n = 30) or at 21 °C (Warm-group, n = 30) during the first 7 days after TKA according to a fixed schedule. All patients received the same pre-, peri- and postoperative care with a multimodal pain protocol. Pain was assessed before and after every session of cryotherapy using the numerical rating scale for pain (NRS-pain). The consumption of opioids was strictly noted during the first 4 postoperative days. Secondary outcomes were knee swelling, visual hematoma and patient reported outcome measures (PROMs). These parameters were measured pre-, 1, 2 and 6 weeks postoperatively. RESULTS: In both study groups, a reduction in NRS-pain after every CAC session were seen during the postoperative period of 7 days. A mean reduction of 0.9 and 0.7 on the NRS-pain was seen for respectively the Cold- (P = 0.008) and Warm-group (n.s.). A significant (P = 0.001) lower number of opioids were used by the Cold-group during the acute postoperative phase of 4 days, 47 and 83 tablets for respectively the Cold and Warm-group. No difference could be observed for secondary outcomes and adverse effects between both study groups. CONCLUSIONS: Postoperative CAC can be in added value in patients following an outpatient surgery pathway for TKA, resulting in reduced experienced pain and consumption of opioids during the first postoperative days.

Favourable alignment outcomes with MRI-based patient-specific instruments in total knee arthroplasty.

PURPOSE: Patient-specific instruments (PSIs) are already in relatively common use, and their post-operative radiographic results are equal to those for total knee arthroplasty (TKA) with conventional instrumentation. PSI use requires a preoperative MRI scan, CT scan, or a combination of MRI and a long-leg standing radiograph. However, there is no consensus as to which of these modalities, MRI or CT, is the preferred imaging modality when performing TKA with PSIs. METHODS: This systematic literature review and meta-analysis studied the differences in alignment outliers between CT- and MRI-based PSI for TKA. A search of the Cochrane Database of Systematic Reviews, MEDLINE/PubMed and Embase was conducted, without restriction on date of publication. Only level I evidence studies written in English that included TKA with the use of MRI- and CT-based PSI were selected. A meta-analysis was then performed of the rate of outliers in the biomechanical axis and individual femoral and tibial component alignment. Where considerable heterogeneity among studies was present or the data did not provide sufficient information for performing the meta-analysis, a qualitative synthesis was undertaken. RESULTS: Twelve randomized controlled trials, studying 841 knees, were eligible for data extraction and meta-analysis. MRI-based PSI resulted in a significantly lower proportion of coronal plane outliers with regard to the lateral femoral component (OR 0.52, 95% CI 0.30-0.89, P = 0.02), without significant heterogeneity (n.s.). There were no significant differences regarding the biomechanical axis or frontal femoral and individual tibial component alignment. CONCLUSION: This systematic review and meta-analysis demonstrate that alignment with MRI-based PSI is at least as good as, if not better than, that with CT-based PSI. To prevent for malalignment, MRI should be the imaging modality of choice when performing TKA surgery with PSI. LEVEL OF EVIDENCE: I.

Consistency in patient-reported outcome measures after total knee arthroplasty using patient-specific instrumentation: a 5-year follow-up of 200 consecutive cases.

PURPOSE: The purpose of this study was to evaluate the 5-year follow-up results of the first 200 total knee arthroplasties (TKA) performed by one high-volume surgeon, using patient-specific information (PSI). To date, there has been no other research into the mid-term follow-up of TKA performed using PSI. MATERIALS AND METHODS: A total of 184 consecutive patients (200 TKA) were evaluated. Outcome measures included implant survival rate, adverse events, and the following patient-reported outcome measures (PROMs); Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), Pain Visual Analogue Score (VAS) and EuroQol-5D Score (EQ-5D). RESULTS: Revision surgery was performed for late secondary prosthetic joint infection (n = 1, total revision), aseptic loosening (n = 1, tibial component revision), instability (n = 1, isolated polyethylene insert exchange), and polyethylene insert breakage (n = 1, isolated polyethylene insert exchange). Other adverse events were as follows: debridement, antibiotics and implant retention for early prosthetic joint infection (n = 1), surgical debridement for haemarthrosis (n = 1), superficial wound infection (n = 2), thromboembolic events (n = 2), compartment syndrome (n = 1), and nerve injury (n = 2). All median outcome scores for patient reported outcome measures at 5 years improved significantly compared with the preoperative values (p ≤ 0.05). Median outcome scores were not significantly different between 1- and 5-year moments of follow-up, except for a significant decrease of EQ-VAS (p ≤ 0.05) between these two follow-up moments. CONCLUSION: PROMs are consistent for 5-year follow-up of TKA using PSI. After 5 years of follow-up, revision surgery for any reason occurred in four patients (2%). LEVEL OF EVIDENCE: III.

Revision of partial knee to total knee arthroplasty with use of patient-specific instruments results in acceptable femoral rotation.

PURPOSE: Patient-specific instruments (PSI) were initially developed for the alignment of both total knee- (TKA) and partial knee arthroplasty (PKA). We hypothesize that CT-based PSI for PKA-to-TKA revision surgery can restore biomechanical limb alignment and prosthetic component positioning in vivo as calculated pre-operatively, resulting in a limited percentages of outliers. METHODS: An imaging analysis was performed using CT-based 3D measurement methods based on a pre- and post-revision CT scan. Imaging data were gathered on 10 patients who were operated for PKA-to-TKA revision with the use of PSI based on CT imaging. The planned femur and tibia component position in vivo were compared with the pre-revision planned component position. Outliers were defined as deviations >3.0° from pre-revision planned position for the individual implant components. Adjustments (e.g. resection level and implant size) during surgery were recorded. RESULTS: The HKA axis was restored accurately in all patients with a mean post-operative HKA axis of 178.1° (1.4°). Five femoral (2 varus, 2 internal rotation and 1 extension) and 14 tibial guides (2 varus, 6 anterior slope, 3 internal rotation and 3 external rotation) on a total of 60 outcome measures were identified as outliers. During surgery, an intraoperative tibial resection of 2 mm extra was performed in three patients. In 80 and 70% for, respectively, the femur and tibia, the surgeon-planned size was implanted during surgery. All patient-specific guides fitted well in all patients. No intraoperative or post-operative complications related to surgery were registered. CONCLUSIONS: This study introduced a unique new concept regarding PSI, PKA-to-TKA revision surgery. Based on the results, we were unable to fully confirm our hypothesis. PSI as a "new" tool for PKA-to-TKA revision surgery appears to be an accurate tool for the alignment of the TKA femur component. The tibial guide seems more susceptible to errors, resulting in a substantial percentage of outliers. LEVEL OF EVIDENCE: Prospective cohort study, Level II.

Outpatient surgery for unicompartmental knee arthroplasty is effective and safe.

PURPOSE: There has been increasing interest in accelerated programs for knee arthroplasty. We examined the efficacy and safety of an outpatient surgery (OS) pathway in patients undergoing unicompartmental knee arthroplasty (UKA). METHODS: This case-controlled study evaluates patients operated for UKA in an OS pathway (n = 20) compared to rapid recovery (RR), the current standard (n = 20). We investigated whether patients could be discharged on the day of surgery, resulting in comparable or better outcome by means of adverse events (AEs) in terms of pain (numerical rating scale, NRS), incidences of postoperative nausea and vomiting (PONV) and opiate use (<48 h postoperatively), complication and readmission rates (<3 months postoperatively). Patient-reported outcome measures (PROMS) were obtained preoperatively and 3 months postoperatively. RESULTS: Postoperative pain (NRS > 5) was the most common reason for prolonged hospital stay in the OS pathway. Eighty-five per cent of the patients were discharged on the day of surgery, whereas 95 % of the patients were discharged on postoperative day 3 in the RR pathway. Overall, median pain scores in both pathways did not exceed a NRS score of 5, without significant differences (RR vs. OS) in the number of patients with PONV (4 vs. 2) and opiate use (11 vs. 9) <48 h postoperatively. At 3 months postoperatively, no significant differences were found for AEs and PROMS between both pathways. CONCLUSION: The results of this study illustrates that an OS pathway for UKA is effective and safe with acceptable clinical outcome. Well-established and adequate standardized protocols, inclusion and exclusion criteria and a change in mindset for both the patient and the multidisciplinary team are the key factors for the implementation of an OS pathway. LEVEL OF EVIDENCE: Case-control study, Level III.

Patient-specific instruments for total knee arthroplasty can accurately predict the component size as used peroperative.

PURPOSE: Patients-specific instruments (PSI) for implantation of total knee arthroplasty (TKA) can be used to predict the implant size for both the femur and the tibia component. This study aims to determine the impact of approval of the PSI planning for TKA on the frequency of, and reason for intraoperative changes of implant sizes. METHODS: The clinical records of 293 patients operated with MRI- (90.4 %) and CT-based (9.6 %) PSI were reviewed for actual used implant size. Preoperative default planning from the technician and approved planning by the operating surgeon were compared with the intraoperative implanted component size for both the femur and tibia. Intraoperative reason for not following the default sizes was outdated. Furthermore, MRI- and CT-based PSI were compared for these outcomes. RESULTS: In 93.9 and 91.1 % for, respectively, the femur and tibia (n.s.), the surgeon planned size was implanted during surgery. The predicted size of the femur (p < 0.00) and the tibia (p < 0.00) component planned by a technician differed from the implanted component sizes in 62 (21.2 %) and 51 (17.4 %) patients, respectively. In 17 cases, the femoral component size was adapted intraoperative based on the expert opinion of the operating surgeon. In 26 cases, the tibia component was changed during the surgery because of a mediolateral overhang, sclerotic bone, medial or lateral release, limited extension and/or fixed varus deformity. The results between the MRI- and CT-based PSI did not differ (n.s.). CONCLUSIONS: PSI is a tool to help the surgeon to achieve the best possible results during TKA. The planning made by a technician should always be validated and approved by the operating surgeon who has the ultimate responsibility regarding the operation. With PSI, the operating surgeon is able to minimize intraoperative implant size errors in advance to improve operating room efficiency with possible lowering hospital costs per procedure. LEVELS OF EVIDENCE: III.

No advantage of adrenaline in the local infiltration analgesia mixture during total knee arthroplasty.

PURPOSE: Local infiltration analgesia (LIA) is widely applied in patients undergoing total knee arthroplasty (TKA). In daily practice, adrenaline is added to the LIA mixture to achieve vasoconstriction. However, adrenaline has some possible negative side effects (e.g. tissue necrosis). This trial investigated whether ropivacaine alone is at least as effective for postoperative pain relief after LIA. METHODS: Fifty patients scheduled for primary TKA were included in this prospective randomized, double-blind, controlled pilot study receiving high-volume (150 mL) single-shot intra-capsular LIA with ropivacaine (2 %) with (Ropi+) or without (Ropi-) adrenaline (0.01 %). All patients received the same pre-, peri- and postoperative care with multimodal oral pain protocol. Postoperative pain was assessed before and after the first mobilization and during the first 48 h postoperative using the visual analogue scale (VAS). Secondary outcomes were rescue medication use, early mobilization, length of hospital stay, adverse events (AE's) and readmission rates. Patient reported outcomes measures (PROMS); Oxford Knee Score and WOMAC, were obtained preoperative and 3 months postoperative. RESULTS: VAS scores were not significantly different before (n.s.) and after the first mobilization (n.s.), neither over the first 48 h postoperative (n.s.). Patients who needed rescue medication (n.s.), who mobilized <6 h postoperative (n.s.), who were discharged before postoperative day 3 (n.s.), AE's and readmission rate (n.s.) were comparable between both groups. At 3-month follow-up, PROMS significantly improved within both groups. CONCLUSION: To prevent possible negative side effects (e.g. tissue necrosis), adrenaline should be omitted from the LIA mixture. Single-shot LIA with ropivacaine alone results in clinical acceptable adequate pain control and can be used in daily TKA practice. LEVEL OF EVIDENCE: Randomized, double-blind, prospective clinical trial, Level I.

Patient-specific positioning guides for total knee arthroplasty: no significant difference between final component alignment and pre-operative digital plan except for tibial rotation.

PURPOSE: To assess whether there is a significant difference between the alignment of the individual femoral and tibial components (in the frontal, sagittal and horizontal planes) as calculated pre-operatively (digital plan) and the actually achieved alignment in vivo obtained with the use of patient-specific positioning guides (PSPGs) for TKA. It was hypothesised that there would be no difference between post-op implant position and pre-op digital plan. METHODS: Twenty-six patients were included in this non-inferiority trial. Software permitted matching of the pre-operative MRI scan (and therefore calculated prosthesis position) to a pre-operative CT scan and then to a post-operative full-leg CT scan to determine deviations from pre-op planning in all three anatomical planes. RESULTS: For the femoral component, mean absolute deviations from planning were 1.8° (SD 1.3), 2.5° (SD 1.6) and 1.6° (SD 1.4) in the frontal, sagittal and transverse planes, respectively. For the tibial component, mean absolute deviations from planning were 1.7° (SD 1.2), 1.7° (SD 1.5) and 3.2° (SD 3.6) in the frontal, sagittal and transverse planes, respectively. Absolute mean deviation from planned mechanical axis was 1.9°. The a priori specified null hypothesis for equivalence testing: the difference from planning is >3 or <-3 was rejected for all comparisons except for the tibial transverse plane. CONCLUSION: PSPG was able to adequately reproduce the pre-op plan in all planes, except for the tibial rotation in the transverse plane. Possible explanations for outliers are discussed and highlight the importance for adequate training surgeons before they start using PSPG in their day-by-day practise. LEVEL OF EVIDENCE: Prospective cohort study, Level II.

Patient selection criteria for outpatient joint arthroplasty.

PURPOSE: General consensus of patient selection criteria for outpatient joint arthroplasty is lacking, which is paramount to prevent prolonged hospital stay, adverse events and/or readmissions. This review highlights patient selection criteria for OJA based on the current literature and expert opinion. METHODS: A search of the English and International electronic healthcare databases including MEDLINE/PubMed, EMBASE, AMED and the Cochrane library was performed in November 2015 to include studies published during the last 10 years. Furthermore, a survey of physicians from different specialties was performed. RESULTS: Fourteen studies described results regarding outpatient joint arthroplasty. Studies on outpatient hip and/or knee arthroplasty resulted in similar outcome in preselected patients. Patients who are able and willing to participate, with a low ASA classification (II), bleeding disorders, poorly controlled and/or severe cardiac (e.g. heart failure, arrhythmia) or pulmonary (e.g. embolism, respiratory failure) comorbidities, uncontrolled DM (type I or II), a high BMI (>30 m2/kg), chronic opioid consumption, functional neurological impairments, dependent functional status, chronic/end-stage renal disease and/or reduced preoperative cognitive capacity should be excluded from outpatient joint arthroplasty. The expert opinion-based selection criteria were comparable to literature with a further extension of exclusion for patients with practical issue's, urologic medical history and/or severe mobility disorders. CONCLUSION: Based on the current literature, the presented patient selection criteria provide a basis for outpatient joint arthroplasty and can be useful when selecting patients. Together with a change in mindset, a multidisciplinary approach and literature-based protocols, outpatient joint arthroplasty can be applied in daily orthopaedic practice while ensuring patients' safety. LEVEL OF EVIDENCE: Clinical review, Level III.

Measurement of lower limb alignment: there are within-person differences between weight-bearing and non-weight-bearing measurement modalities.

PURPOSE: Previous studies have compared weight-bearing mechanical leg axis (MLA) measurements to non-weight-bearing measurement modalities. Most of these studies compared mean or median values and did not analyse within-person differences between measurements. This study evaluates the within-person agreement of MLA measurements between weight-bearing full-length radiographs (FLR) and non-weight-bearing measurement modalities (computer-assisted surgery (CAS) navigation or MRI). MATERIALS AND METHODS: Two independent observers measured the MLA on pre- and postoperative weight-bearing FLR in 168 patients. These measurements were compared to non-weight-bearing measurements obtained by CAS navigation or MRI. Absolute differences in individual subjects were calculated to determine the agreement between measurement modalities. Linear regression was used to evaluate the possibility that other independent variables impact the differences in measurements. RESULTS: A difference was found in preoperative measurements between FLR and CAS navigation (mean of 2.5° with limit of agreement (1.96 SD) of 6.4°), as well as between FLR and MRI measurements (mean of 2.4° with limit of agreement (1.96 SD) of 6.9°). Postoperatively, the mean difference between MLA measured on FLR compared to CAS navigation was 1.5° (limit of agreement (1.96 SD) of 4.6°). Linear regression analysis showed that weight-bearing MLA measurements vary significantly from non-weight-bearing MLA measurements. Differences were more severe in patients with mediolateral instability (p = 0.010), age (p = 0.049) and ≥3° varus or valgus alignment (p = 0.008). CONCLUSION: The clinical importance of this study lies in the finding that there are within-person differences between weight-bearing and non-weight-bearing measurement modalities. This has implications for preoperative planning, performing total knee arthroplasty (TKA), and clinical follow-up after TKA surgery using CAS navigation or patient-specific instrumentation. LEVEL OF EVIDENCE: III.

Results of Cemented Anatomically Adapted Total Hip Arthroplasty: A Follow-Up Longer Than 10 years.

This retrospective single-center study evaluated the >10-year follow-up (FU) and survival of 2 anatomically adapted cemented total hip arthroplasties (THAs) in a series of 308 patients (323 THAs) with a mean age of 76.2 years at operation. At a mean of 11 years of FU, patient-reported outcome measures, clinical examination, and plain radiography were analyzed. In 6 THAs, the femoral and/or acetabular component was revised. Reasons for revision were aseptic loosening and infection. At >10 years of FU, there was an overall survival for both THAs of 98.1%. Radiographic radiolucent lines were seen in 15 THAs affecting Gruen zone 4 and Delee and Charnley zone II. We conclude that both anatomically adapted cemented THAs have an excellent survival at 11 years of FU.

No radiographic difference between patient-specific guiding and conventional Oxford UKA surgery.

PURPOSE: Implant position is an important factor in unicompartmental knee arthroplasty (UKA) surgery. Results on conventional UKA alignment are commonly described in literature. Patient-specific guiding (PSG) is a new technique for positioning the Oxford UKA. Our hypothesis is that PSG improves component position without affecting the HKA angle. METHODS: This prospective study compares the results of our first thirty cases of cementless Oxford UKA using PSG with thirty cases using conventional outlining. Baseline characteristics for both groups were identical. Details on handling of the guide, estimated blood loss and operation time were recorded. Postoperative screened radiographs and standing long-leg radiographs of both groups were compared. RESULTS: Median AP position of the femoral component was 3 degrees varus (-5 to 9) using PSG versus 2 degrees varus (-10 to 8) for the conventional group. For the femoral flexion, this was 9 degrees flexion (0-16) using PSG versus 12 degrees flexion (0-20). The tibial median AP position was 1 degree varus (-3 to 7) using PSG versus 2 degrees varus (-5 to 10). The median tibial posterior slope was 5 degrees (1-10) using PSG versus 5 degrees (0-12). All guides aligned well. No conversion to conventional outlining was performed, and no significant changes had to be made to the original approved plan. Operation time, estimated blood loss and postoperative haemoglobin drop were not significantly different between both groups. DISCUSSION: Implant position was not different between both groups, even in the early phase of the learning curve. Perioperative results were not different between both groups. LEVEL OF EVIDENCE: III.

Preliminary experience with the patient-specific templating total knee arthroplasty.

BACKGROUND AND PURPOSE: Patient-specific templating total knee arthroplasty (TKA) is a new method for alignment of a total knee arthroplasty that uses disposable guides. We present the results of the first 40 consecutive patients who were operated on using this technique. METHODS: In this case-control study, we compared blood loss, operation time, and alignment of 40 TKAs performed using a patient-specific templating alignment technique with values from a matched control group of patients who were operated on by conventional intramedullary alignment technique. Alignment of the mechanical axis of the leg and flexion/extension and varus/valgus of the individual prosthesis components were measured on standing, long-leg, and standard lateral digital radiographs. The fraction of outliers (> 3˚) was determined. RESULTS: Mean mechanical axis of templating TKAs was 181° with a fraction of outliers of 0.3, and mean mechanical axis of conventional TKAs was 179˚ (outlier fraction 0.5). Fraction of outliers in the frontal plane for femoral components was 0.05 in the templating TKAs and 0.4 in the conventional TKAs, and for tibial components the corresponding values were 0.2 and 0.2. In the templating TKAs and conventional TKAs, fraction of outliers in the sagittal plane was 0.4 and 0.9, respectively, for femoral components and 0.4 and 0.6 for tibial components. Mean operation time was 10 min shorter and blood loss was 60 mL less for templating TKA than for intramedullary-aligned TKAs. INTERPRETATION: Patient-specific templating TKA showed improved accuracy of alignment and a small reduction in blood loss and operating time compared to intramedullary-aligned TKA, but the fraction of outliers was relatively high. Larger RCTs are needed for further evaluation of the technique and to define the future role of patient-specific template alignment techniques for TKA.

Impact of enhanced recovery pathways on safety and efficacy of hip and knee arthroplasty: A systematic review and meta-analysis.

BACKGROUND: Over the past decades, clinical pathways (CPs) for hip and knee arthroplasty have been strongly and continuously evolved based on scientific evidence and innovation. AIM: The present systematic review, including meta-analysis, aimed to compare the safety and efficacy of enhanced recovery pathways (ERP) with regular pathways for patients with hip and/or knee arthroplasty. METHODS: A literature search in healthcare databases (Embase, PubMed, Cochrane Library, CINAHL, and Web of Science) was conducted from inception up to June 2018. Relevant randomized controlled trials as well as observational studies comparing ERP, based on novel evidence, with regular or standard pathways, prescribing care as usual for hip and/or knee arthroplasty, were included. The effect of both CPs was assessed for (serious) adverse events [(S)AEs], readmission rate, length of hospital stay (LoS), clinician-derived clinical outcomes, patient reported outcome measures (PROMs), and financial benefits. If possible, a meta-analysis was performed. In case of considerable heterogeneity among studies, a qualitative analysis was performed. RESULTS: Forty studies were eligible for data extraction, 34 in meta-analysis and 40 in qualitative analysis. The total sample size consisted of more than 2 million patients undergoing hip or knee arthroplasty, with a mean age of 66 years and with 60% of females. The methodological quality of the included studies ranged from average to good. The ERP had lower (S)AEs [relative risk (RR): 0.9, 95% confidence interval (CI): 0.8-1] and readmission rates (RR: 0.8, 95%CI: 0.7-1), and reduced LoS [median days 6.5 (0.3-9.5)], and showed similar or improved outcomes for functional recovery and PROMs compared to regular pathways. The analyses for readmission presented a statistically significant difference in the enhanced recovery pathway in favor of knee arthroplasties (P = 0.01). ERP were reported to be cost effective, and the cost reduction varied largely between studies (€109 and $20573). The overall outcomes of all studies reported using Grading of Recommendation, Assessment, Development and Evaluation, presented moderate or high quality of evidence. CONCLUSION: This study showed that implementation of ERP resulted in improved clinical and patient related outcomes compared to regular pathways in hip and knee arthroplasty, with a potential reduction of costs.

Long-Term Residual-Mobility and Adjacent Segment Disease After Total Lumbar Disc Replacement.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Total disc replacement (TDR) has been introduced in order to preserve segmental motion and thus reduce adjacent segment disease (ASD) as seen after spinal fusion. However, it is uncertain whether these presumed beneficial effects remain. The aim of this study was to evaluate the long-term incidence of ASD and residual-mobility in relation to clinical outcome. METHODS: A total of 210 patients treated with lumbar TDR for degenerative disc disease were invited for follow-up. ASD was reported in case of severe degeneration in an adjacent disc at latest follow-up, or if an increase in disc degeneration was observed in these adjacent segments as compared to direct postoperative radiographs. Residual-mobility of the TDR was defined as a minimal rotation of 4.6° on flexion-extension radiographs. Patient-reported outcome measures were obtained. RESULTS: Fifty-seven patients (27.1%) were lost to follow-up. In 32 patients (15.3%) a revision by spinal fusion had been performed. In 20 patients this revision had occurred ≥5 years after TDR and were included. Consequently, 141 patients were available for analysis (mean follow-up of 16.7 years). Residual-mobility was noted in 38.0%. No significant associations were observed between residual-mobility and the occurrence of ASD, or with clinical outcome. In addition, ASD and clinical outcome were not related either. CONCLUSIONS: It appears that long-term preservation of motion after TDR is met for only a third of patients. However, residual-mobility is not associated with the occurrence of ASD, and both residual-mobility and ASD do not appear to be related to long-term clinical outcome.

Home-based management of knee osteoarthritis during COVID-19 pandemic: literature review and evidence-based recommendations.

PURPOSE: To provide evidence-based recommendations for patients with severe knee osteoarthritis (OA), who had their knee surgery postponed due to the COVID-19 pandemic. METHODS: PubMed/Medline, Scopus and Cochrane Central databases were systematically reviewed for studies reporting outcomes of home-based treatments for knee OA. Due to between-study differences in treatment strategy and reporting methods the results were not pooled and findings of the current review were presented in a narrative manner. RESULTS: The comprehensive literature search yielded 33 eligible studies that were included in this review. Management is performed at home and consists of exercise, proper nutrition, physical therapy and use of corrective and assistive orthotics. Virtual education on self-management strategies should be part of coping with knee OA. Initiating an exercise programme involving gymnastics, stretching, home cycling and muscle strengthening is highly recommended. Obese patients are encouraged to set weight loss goals and adopt a healthy diet. Potential benefits but weak evidence has been shown for the use of knee braces, sleeves, foot orthotics or cushioned footwear. Walking aids may be prescribed, when considered necessary, along with the provision of instructions for their use. CONCLUSION: When bridging the time to rescheduled surgery, it is essential to use appropriate home-based tools for the management of knee OA if pain is to be reduced and need for analgesics or opioid use is to be diminished while maintaining or even improving the functioning and avoiding further limitation of range of motion and subsequent muscular atrophies. Finally, none of these treatments may completely substitute for the life-changing effect of a total knee arthroplasty in patients with severe knee OA. Hence, the subsequent goal is to gradually and safely reinstate elective surgery.