Aims. The liner design is a key determinant of the constraint of a reverse total shoulder arthroplasty (rTSA). The aim of this study was to compare the degree of constraint of rTSA liners between different implant systems. Methods. An implant company’s independent 3D shoulder arthroplasty planning software (mediCAD 3D shoulder v. 7.0, module v. 2.1.84.173.43) was used to determine the jump height of standard and constrained liners of different sizes (radius of curvature) of all available companies. The obtained parameters were used to calculate the stability ratio (degree of constraint) and angle of coverage (degree of glenosphere coverage by liner) of the different systems. Measurements were independently performed by two raters, and intraclass correlation coefficients were calculated to perform a reliability analysis. Additionally, measurements were compared with parameters provided by the companies themselves, when available, to ensure validity of the software-derived measurements. Results. There were variations in jump height between rTSA systems at a given size, resulting in large differences in stability ratio between systems. Standard liners exhibited a stability ratio range from 126% to 214% (mean 158% (SD 23%)) and constrained liners a range from 151% to 479% (mean 245% (SD 76%)). The angle of coverage showed a range from 103° to 130° (mean 115° (SD 7°)) for standard and a range from 113° to 156° (mean 133° (SD 11°)) for constrained liners. Four arthroplasty systems kept the stability ratio of standard liners constant (within 5%) across different sizes, while one system showed slight inconsistencies (within 10%), and ten arthroplasty systems showed large inconsistencies (range 11% to 28%). The stability ratio of constrained liners was consistent across different sizes in two arthroplasty systems and inconsistent in seven systems (range 18% to 106%). Conclusion. Large differences in jump height and resulting degree of constraint of rTSA liners were observed between different implant systems, and in many cases even within the same implant systems. While the immediate clinical effect remains unclear, in theory the degree of constraint of the liner plays an important role for the dislocation and notching risk of a rTSA system. Cite this article: Bone Jt Open 2024;5(10):818–824

Aims. Mid-level constraint designs for total knee arthroplasty (TKA) are intended to reduce coronal plane laxity. Our aims were to compare kinematics and ligament forces of the Zimmer Biomet Persona posterior-stabilized (PS) and mid-level designs in the coronal, sagittal, and axial planes under loads simulating clinical exams of the knee in a cadaver model. Methods. We performed TKA on eight cadaveric knees and loaded them using a robotic manipulator. We tested both PS and mid-level designs under loads simulating clinical exams via applied varus and valgus moments, internal-external (IE) rotation moments, and anteroposterior forces at 0°, 30°, and 90° of flexion. We measured the resulting tibiofemoral angulations and translations. We also quantified the forces carried by the medial and lateral collateral ligaments (MCL/LCL) via serial sectioning of these structures and use of the principle of superposition. Results. Mid-level inserts reduced varus angulations compared to PS inserts by a median of 0.4°, 0.9°, and 1.5° at 0°, 30°, and 90° of flexion, respectively, and reduced valgus angulations by a median of 0.3°, 1.0°, and 1.2° (p ≤ 0.027 for all comparisons). Mid-level inserts reduced net IE rotations by a median of 5.6°, 14.7°, and 17.5° at 0°, 30°, and 90°, respectively (p = 0.012). Mid-level inserts reduced anterior tibial translation only at 90° of flexion by a median of 3.0 millimetres (p = 0.036). With an applied varus moment, the mid-level insert decreased LCL force compared to the PS insert at all three flexion angles that were tested (p ≤ 0.036). In contrast, with a valgus moment the mid-level insert did not reduce MCL force. With an applied internal rotation moment, the mid-level insert decreased LCL force at 30° and 90° by a median of 25.7 N and 31.7 N, respectively (p = 0.017 and p = 0.012). With an external rotation moment, the mid-level insert decreased MCL force at 30° and 90° by a median of 45.7 N and 20.0 N, respectively (p ≤ 0.017 for all comparisons). With an applied anterior load, MCL and LCL forces showed no differences between the two inserts at 30° and 90° of flexion. Conclusion. The mid-level insert used in this study decreased coronal and axial plane laxities compared to the PS insert, but its stabilizing benefit in the sagittal plane was limited. Both mid-level and PS inserts depended on the MCL to resist anterior loads during a simulated clinical exam of anterior laxity. Cite this article: Bone Jt Open 2023;4(6):432–441

Total knee arthroplasty (TKA) is a major orthopaedic intervention. The length of a patient's stay has been progressively reduced with the introduction of enhanced recovery protocols: day-case surgery has become the ultimate challenge. This narrative review shows the potential limitations of day-case TKA. These constraints may be social, linked to patient’s comorbidities, or due to surgery-related adverse events (e.g. pain, post-operative nausea and vomiting, etc.). . Using patient stratification, tailored surgical techniques and multimodal opioid-sparing analgesia, day-case TKA might be achievable in a limited group of patients. The younger, male patient without comorbidities and with an excellent social network around him might be a candidate. Demographic changes, effective recovery programmes and less invasive surgical techniques such as unicondylar knee arthroplasty, may increase the size of the group of potential day-case patients. . The cost reduction achieved by day-case TKA needs to be balanced against any increase in morbidity and mortality and the cost of advanced follow-up at a distance with new technology. These factors need to be evaluated before adopting this ultimate ‘fast-track’ approach. . Cite this article: Bone Joint J 2015;97-B(10 Suppl A):40–4

Aims

Anterior cruciate ligament (ACL) and multiligament knee (MLK) injuries increase the risk of development of knee osteoarthritis and eventual need for total knee arthroplasty (TKA). There are limited data regarding implant use and outcomes in these patients. The aim of this study was to compare the use of constrained implants and outcomes among patients undergoing TKA with a history of prior knee ligament reconstruction (PKLR) versus a matched cohort of patients undergoing TKA with no history of PKLR.

Debate has raged over whether a cruciate retaining (CR) or a posterior stabilised (PS) total knee replacement (TKR) provides a better range of movement (ROM) for patients. Various sub-sets of CR design are frequently lumped together when comparing outcomes. Additionally, multiple factors have been proven to influence the rate of manipulation under anaesthetic (MUA) following TKR. The purpose of this study was to determine whether different CR bearing insert designs provide better ROM or different MUA rates. All primary TKRs performed by two surgeons between March 2006 and March 2009 were reviewed and 2449 CR-TKRs were identified. The same CR femoral component, instrumentation, and tibial base plate were consistently used. In 1334 TKRs a CR tibial insert with 3° posterior slope and no posterior lip was used (CR-S). In 803 there was an insert with no slope and a small posterior lip (CR-L) and in 312 knees the posterior cruciate ligament (PCL) was either resected or lax and a deep-dish, anterior stabilised insert was used (CR-AS). More CR-AS inserts were used in patients with less pre-operative ROM and greater pre-operative tibiofemoral deformity and flexion contracture (p < 0.05). The mean improvement in ROM was highest for the CR-AS inserts (5.9° (-40° to 55°) vs CR-S 3.1° (-45° to 70°) vs CR-L 3.0° (-45° to 65°); p = 0.004). There was a significantly higher MUA rate with the CR-S and CR-L inserts than CR-AS (Pearson rank 6.51; p = 0.04). Despite sacrificing or not substituting for the PCL, ROM improvement was highest, and the MUA rate was lowest in TKRs with a deep-dish, anterior-stabilised insert. Substitution for the posterior cruciate ligament (PCL) in the form of a PS design may not be necessary even when the PCL is deficient.

Cite this article: Bone Joint J 2013;95-B, Supple A:129–32.

Aims

Varus-valgus constrained (VVC) implants are often used during revision total knee arthroplasty (TKA) to gain coronal plane stability. However, the increased mechanical torque applied to the bone-cement interface theoretically increases the risk of aseptic loosening. We assessed mid-term survivorship, complications, and clinical outcomes of a fixed-bearing VVC device in revision TKAs.

Aims. 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))?. Methods. 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. Results. No statistically significant differences were found regarding coronal alignment (p = 0.087 to p = 0.832). The medial congruent insert demonstrated restricted femoral roll back (mean medial 37.57 mm; lateral 36.34 mm), while the CR insert demonstrated the greatest roll back (medial 42.21 mm; lateral 37.88 mm; p < 0.001, respectively). Femorotibial rotation was greatest with the CR insert with 2.45° (SD 4.75°), then the UC insert with 1.31° (SD 4.15°; p < 0.001), and lowest with the medial congruent insert with 0.8° (SD 4.24°; p < 0.001). The most pronounced patella shift, but lowest patellar rotation, was noted with the CR insert. Conclusion. The MC insert demonstrated the highest level of constraint of these inserts. Femoral roll back, femorotibial rotation, and single bony rotations were lowest with the MC insert. The patella showed less shifting with the MC insert, but there was significantly increased rotation. While the medial congruent insert was found to have highest constraint, it remains uncertain if this implant recreates native knee kinematics or if this will result in improved patient satisfaction. Cite this article: Bone Jt Open 2024;5(7):592–600

Aims. Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs. Methods. A retrospective review of our total joint registry identified 94 patients with post-polio syndrome undergoing 116 primary TKAs between January 2000 and December 2019. The mean age was 70 years (33 to 86) with 56% males (n = 65) and a mean BMI of 31 kg/m. 2. (18 to 49). Rotating hinge TKAs were used in 14 of 63 affected limbs (22%), but not in any of the 53 unaffected limbs. Kaplan-Meier survivorship analyses were completed. The mean follow-up was eight years (2 to 19). Results. The ten-year survivorship free from revision was 91% (95% confidence interval (CI) 81 to 100) in affected and 84% (95% CI 68 to 100) in unaffected limbs. There were six revisions in affected limbs: three for periprosthetic femoral fractures and one each for periprosthetic joint infection (PJI), patellar clunk syndrome, and instability. Unaffected limbs were revised in four cases: two for instability and one each for PJI and tibial component loosening. The ten-year survivorship free from any reoperation was 86% (95% CI 75 to 97) and 80% (95% CI 64 to 99) in affected and unaffected limbs, respectively. There were three additional reoperations among affected and two in unaffected limbs. There were 12 nonoperative complications, including four periprosthetic fractures. Arthrofibrosis occurred in five affected (8%) and two unaffected limbs (4%). Postoperative range of motion decreased with 31% achieving less than 90° knee flexion by five years. Conclusion. TKAs in post-polio patients are complex cases associated with instability, and one in four require constraint on the affected side. Periprosthetic fracture was the main mode of failure. Arthrofibrosis rates were high and twice as frequent in affected limbs. Cite this article: Bone Joint J 2023;105-B(6):635–640

Aims. We have previously reported the mid-term outcomes of revision total knee arthroplasty (TKA) for flexion instability. At a mean of four years, there were no re-revisions for instability. The aim of this study was to report the implant survivorship and clinical and radiological outcomes of the same cohort of of patients at a mean follow-up of ten years. Methods. The original publication included 60 revision TKAs in 60 patients which were undertaken between 2000 and 2010. The mean age of the patients at the time of revision TKA was 65 years, and 33 (55%) were female. Since that time, 21 patients died, leaving 39 patients (65%) available for analysis. The cumulative incidence of any re-revision with death as a competing risk was calculated. Knee Society Scores (KSSs) were also recorded, and updated radiographs were reviewed. Results. The cumulative incidence of any re-revision was 13% at a mean of ten years. At the most recent-follow-up, eight TKAs had been re-revised: three for recurrent flexion instability (two fully revised to varus-valgus constrained implants (VVCs), and one posterior-stabilized (PS) implant converted to VVC, one for global instability (PS to VVC), two for aseptic loosening of the femoral component, and two for periprosthetic joint infection). The ten-year cumulative incidence of any re-revision for instability was 7%. The median KSS improved significantly from 45 (interquartile range (IQR) 40 to 50) preoperatively to 70 (IQR 45 to 80) at a mean follow-up of ten years (p = 0.031). Radiologically, two patients, who had not undergone revision, had evidence of loosening (one tibial and one patellar). The remaining components were well fixed. Conclusion. We found fair functional outcomes and implant survivorship at a mean of ten years after revision TKA for flexion instability with a PS implant. Recurrent instability and aseptic loosening were the most common indications for re-revision. Components with increased constraint, such as a VVC or hinged, should be used in these patients in order to reduce the risk of recurrent instability. Cite this article: Bone Joint J 2022;104-B(10):1126–1131

Aims. Pelvic discontinuity is a rare but increasingly common complication of total hip arthroplasty (THA). This single-centre study evaluated the performance of custom-made triflange acetabular components in acetabular reconstruction with pelvic discontinuity by determining: 1) revision and overall implant survival rates; 2) discontinuity healing rate; and 3) Harris Hip Score (HHS). Methods. Retrospectively collected data of 38 patients (39 hips) with pelvic discontinuity treated with revision THA using a custom-made triflange acetabular component were analyzed. Minimum follow-up was two years (mean 5.1 years (2 to 11)). Results. There were eight subsequent surgical interventions. Two failures (5%) of the triflange acetabular components were both revised because of deep infection. There were seven (18%) patients with dislocation, and five (13%) of these were treated with a constraint liner. One patient had a debridement, antibiotics, and implant retention (DAIR) procedure. In 34 (92%) hips the custom-made triflange component was considered stable, with a healed pelvic discontinuity with no aseptic loosening at midterm follow-up. Mean HHS was 80.5 (48 to 96). Conclusion. The performance of the custom triflange implant in this study is encouraging, with high rates of discontinuity healing and osteointegration of the acetabular implant with no aseptic loosening at midterm follow-up. However, complications are not uncommon, particularly instability which we successfully addressed with constrained liners. Cite this article: Bone Jt Open 2022;3(11):867–876

Aims. This study compared patient-reported outcomes of three total knee arthroplasty (TKA) designs from one manufacturer: one cruciate-retaining (CR) design, and two cruciate-sacrificing designs, anterior-stabilized (AS) and posterior-stabilized (PS). Methods. Patients scheduled for primary TKA were included in a single-centre, prospective, three-armed, blinded randomized trial (n = 216; 72 per group). After intraoperative confirmation of posterior cruciate ligament (PCL) integrity, patients were randomly allocated to receive a CR, AS, or PS design from the same TKA system. Insertion of an AS or PS design required PCL resection. The primary outcome was the mean score of all five subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS) at two-year follow-up. Secondary outcomes included all KOOS subscales, Oxford Knee Score, EuroQol five-dimension health questionnaire, EuroQol visual analogue scale, range of motion (ROM), and willingness to undergo the operation again. Patient satisfaction was also assessed. Results. Patients reported similar levels of pain, function, satisfaction, and general health regardless of the prosthetic design they received. Mean maximal flexion (129° (95% confidence interval (CI) 127° to 131°) was greater in the PS group than in the CR (120° (95% CI 121° to 124°)) and AS groups (122° (95% CI 120° to 124°)). Conclusion. Despite differences in design and constraint, CR, AS, and PS designs from a single TKA system resulted in no differences in patient-reported outcomes at two-year follow-up. PS patients had statistically better ROM, but the clinical significance of this finding is unclear. Cite this article: Bone Joint J 2023;105-B(12):1271–1278

Aims. COVID-19 has compounded a growing waiting list problem, with over 4.5 million patients now waiting for planned elective care in the UK. Views of patients on waiting lists are rarely considered in prioritization. Our primary aim was to understand how to support patients on waiting lists by hearing their experiences, concerns, and expectations. The secondary aim was to capture objective change in disability and coping mechanisms. Methods. A minimum representative sample of 824 patients was required for quantitative analysis to provide a 3% margin of error. Sampling was stratified by body region (upper/lower limb, spine) and duration on the waiting list. Questionnaires were sent to a random sample of elective orthopaedic waiting list patients with their planned intervention paused due to COVID-19. Analyzed parameters included baseline health, change in physical/mental health status, challenges and coping strategies, preferences/concerns regarding treatment, and objective quality of life (EuroQol five-dimension questionnaire (EQ-5D), Generalized Anxiety Disorder 2-item scale (GAD-2)). Qualitative analysis was performed via the Normalization Process Theory. Results. A total of 888 patients responded. Better health, pain, and mood scores were reported by upper limb patients. The longest waiters reported better health but poorer mood and anxiety scores. Overall, 82% had tried self-help measures to ease symptoms; 94% wished to proceed with their intervention; and 21% were prepared to tolerate deferral. Qualitative analysis highlighted the overall patient mood to be represented by the terms ‘understandable’, ‘frustrated’, ‘pain’, ‘disappointed’, and ‘not happy/depressed’. COVID-19-mandated health and safety measures and technology solutions were felt to be implemented well. However, patients struggled with access to doctors and pain management, quality of life (physical and psychosocial) deterioration, and delay updates. Conclusion. This is the largest study to hear the views of this ‘hidden’ cohort. Our findings are widely relevant to ensure provision of better ongoing support and communication, mostly within the constraints of current resources. In response, we developed a reproducible local action plan to address highlighted issues. Cite this article: Bone Jt Open 2021;2(8):583–593

Aims. To fully verify the reliability and reproducibility of an experimental method in generating standardized micromotion for the rat femur fracture model. Methods. A modularized experimental device has been developed that allows rat models to be used instead of large animal models, with the aim of reducing systematic errors and time and money constraints on grouping. The bench test was used to determine the difference between the measured and set values of the micromotion produced by this device under different simulated loading weights. The displacement of the fixator under different loading conditions was measured by compression tests, which was used to simulate the unexpected micromotion caused by the rat’s ambulation. In vivo preliminary experiments with a small sample size were used to test the feasibility and effectiveness of the whole experimental scheme and surgical scheme. Results. The bench test showed that a weight loading < 500 g did not affect the operation of experimental device. The compression test demonstrated that the stiffness of the device was sufficient to keep the uncontrollable motion between fracture ends, resulting from the rat’s daily activities, within 1% strain. In vivo results on 15 rats prove that the device works reliably, without overburdening the experimental animals, and provides standardized micromotion reproductively at the fracture site according to the set parameters. Conclusion. Our device was able to investigate the effect of micromotion parameters on fracture healing by generating standardized micromotion to small animal models. Cite this article: Bone Joint Res 2021;10(11):714–722

Aims. The importance of accurate identification and reporting of surgical site infection (SSI) is well recognised but poorly defined. Public Health England (PHE) mandated collection of orthopaedic SSI data in 2004. Data submission is required in one of four categories (hip prosthesis, knee prosthesis, repair of neck of femur, reduction of long bone fracture) for one quarter per year. Trusts are encouraged to carry out post-discharge surveillance but this is not mandatory. Recent papers in the orthopaedic literature have highlighted the importance of SSI surveillance and the heterogeneity of surveillance methods. However, details of current orthopaedic SSI surveillance practice has not been described or quantified. Patients and Methods. All 147 NHS trusts in England were audited using a structured questionnaire. Data was collected in the following categories: data collection; data submission to PHE; definitions used; resource constraints; post-discharge surveillance and SSI rates in the four PHE categories. The response rate was 87.7%. Results. Variation in practice was clear in all categories in terms of methods and timings of data collection and data submission. There was little agreement on SSI definitions. At least six different definitions were used, some trusts using more than one definition. Post-discharge surveillance was carried out by 62% of respondents but there was again variation in both the methods and staff used. More than half of the respondents felt that SSI surveillance in their unit was limited by resource constraints. SSI rates ranged from 0% to 10%. Conclusion. This paper quantifies the heterogeneity of SSI surveillance in England. It highlights the importance of adequate resourcing and the unreliability of relying on voluntary data collection and submission. Conformity of definitions and methods are recommended to enable meaningful SSI data to be collated. Cite this article: Bone Joint J 2017;99-B:171–4

Aims. The aim of this study was to identify modifiable risk factors associated with mortality in patients requiring revision total hip arthroplasty (THA) for periprosthetic hip fracture. Methods. The electronic records of consecutive patients undergoing revision THA for periprosthetic hip fracture between December 2011 and October 2018 were reviewed. The data which were collected included age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, the preoperative serum level of haemoglobin, time to surgery, operating time, blood transfusion, length of hospital stay, and postoperative surgical and medical complications. Univariate and multivariate logistic regression analyses were used to determine independent modifiable factors associated with mortality at 90 days and one year postoperatively. Results. A total of 203 patients were identified. Their mean age was 78 years (44 to 100), and 108 (53%) were female. The median time to surgery was three days (interquartile range (IQR) 2 to 5). The mortality rate at one year was 13.8% (n = 28). The commonest surgical complication was dislocation (n = 22, 10.8%) and the commonest medical complication within 90 days of surgery was hospital-acquired pneumonia (n = 25, 12%). Multivariate analysis showed that the rate of mortality one year postoperatively was five-fold higher in patients who sustained a dislocation (odds ratio (OR) 5.03 (95% confidence interval (CI) 1.60 to 15.83); p = 0.006). The rate of mortality was also four-fold higher in patients who developed hospital-acquired pneumonia within 90 days postoperatively (OR 4.43 (95% CI 1.55 to 12.67); p = 0.005). There was no evidence that the time to surgery was a risk factor for death at one year. Conclusion. Dislocation and hospital-acquired pneumonia following revision THA for a periprosthetic fracture are potentially modifiable risk factors for mortality. This study suggests that surgeons should consider increasing constraint to reduce the risk of dislocation, and the early involvement of a multidisciplinary team to reduce the risk of hospital-acquired pneumonia. We found no evidence that the time to surgery affected mortality, which may allow time for medical optimization, surgical planning, and resource allocation. Cite this article: Bone Joint J 2020;102-B(5):580–585

The imminent introduction of the new Trauma & Orthopaedic (T&O) curriculum, and the implementation of the Improving Surgical Training initiative, reflect yet another paradigm shift in the recent history of trauma and orthopaedic training. The move to outcome-based training without time constraints is a radical departure from the traditional time-based structure and represents an exciting new training frontier. This paper summarizes the history of T&O training reform, explains the rationale for change, and reflects on lessons learnt from the past. Cite this article: Bone Jt Open 2021;2-3:181–190

Aims. Knee osteonecrosis in advanced stages may lead to joint degeneration. Total knee arthroplasty (TKA) for osteonecrosis has traditionally been associated with suboptimal results. We analyzed outcomes of contemporary TKAs for osteonecrosis, with particular emphasis on: survivorship free from aseptic loosening, any revision, and any reoperation plus the clinical outcomes, complications, and radiological results. Patients and Methods. In total, 156 patients undergoing 167 primary TKAs performed for osteonecrosis between 2004 and 2014 at a single institution were reviewed. The mean age at index TKA was 61 years (14 to 93) and the mean body mass index (BMI) was 30 kg/m. 2. (18 to 51) The mean follow-up was six years (2 to 12). A total of 110 TKAs (66%) were performed for primary osteonecrosis and 57 TKAs (34%) for secondary osteonecrosis. Overall, 15 TKAs (9%) had tibial stems, while 12 TKAs (7%) had femoral stems. Posterior-stabilized designs were used in 147 TKAs (88%) of TKAs. Bivariate Cox regression analysis was conducted to identify risk factors for revision and reoperation. Results. Survivorship free from aseptic loosening, any revision, and any reoperation at ten years was 97% (95% confidence interval (CI) 93 to 100), 93% (95% CI 85 to 100), and 82% (95% CI 69 to 93), respectively. No factors, including age, sex, BMI, primary versus secondary osteonecrosis, stem utilization, and constraint, were identified as risk factors for reoperation. Four TKAs (2%) underwent revision, most commonly for tibial aseptic loosening (n = 2). Excluding revisions and reoperations, there was a total of 11 complications (7%), with the most common being a manipulation under anaesthesia (six TKAs, 4%). Mean Knee Society Scores (Knee component) significantly improved from 57 (32 to 87) preoperatively to 91 (49 to 100) postoperatively (p < 0.001). No unrevised TKAs had complete radiolucent lines or radiological evidence of loosening. Conclusion. Contemporary cemented TKAs with selective stem utilization for osteonecrosis resulted in durable survivorship, a low complication rate, and reliable improvement in clinical outcomes. Cite this article: Bone Joint J 2019;101-B:1356–1361

Aims. There is little literature about total knee arthroplasty (TKA) after distal femoral osteotomy (DFO). Consequently, the purpose of this study was to analyze the outcomes of TKA after DFO, with particular emphasis on: survivorship free from aseptic loosening, revision, or any re-operation; complications; radiological results; and clinical outcome. Patients and Methods. We retrospectively reviewed 29 patients (17 women, 12 men) from our total joint registry who had undergone 31 cemented TKAs after a DFO between 2000 and 2012. Their mean age at TKA was 51 years (22 to 76) and their mean body mass index 32 kg/m. 2. (20 to 45). The mean time between DFO and TKA was ten years (2 to 20). The mean follow-up from TKA was ten years (2 to 16). The prostheses were posterior-stabilized in 77%, varus-valgus constraint (VVC) in 13%, and cruciate-retaining in 10%. While no patient had metaphyseal fixation (e.g. cones or sleeves), 16% needed a femoral stem. Results. The ten-year survivorship was 95% with aseptic loosening as the endpoint, 88% with revision for any reason as the endpoint, and 81% with re-operation for any reason as the endpoint. Three TKAs were revised for instability (n = 2) and aseptic tibial loosening (n = 1). No femoral component was revised for aseptic loosening. Patients under the age of 50 years were at greater risk of revision for any reason (hazard ratio 7; p = 0.03). There were two additional re-operations (6%) and four complications (13%), including three manipulations under anaesthetic (MUA; 10%). The Knee Society scores improved from a mean of 50 preoperatively (32 to 68) to a mean of 93 postoperatively (76 to 100; p < 0.001). Conclusion. A cemented posterior-stabilized TKA has an 88% ten-year survivorship with revision for any reason as the endpoint. No femoral component was revised for aseptic loosening. Patients under the age of 50 years have a greater risk of revision. The clinical outcome was significantly improved but balancing the knee was challenging in 13% of TKAs requiring VVC. Overall, 10% of TKAs needed an MUA, and 6% of TKAs were revised for instability. Cite this article: Bone Joint J 2019;101-B:660–666

Aims. Spinal deformity surgery carries the risk of neurological injury. Neurophysiological monitoring allows early identification of intraoperative cord injury which enables early intervention resulting in a better prognosis. Although multimodal monitoring is the ideal, resource constraints make surgeon-directed intraoperative transcranial motor evoked potential (TcMEP) monitoring a useful compromise. Our experience using surgeon-directed TcMEP is presented in terms of viability, safety, and efficacy. Methods. We carried out a retrospective review of a single surgeon’s prospectively maintained database of cases in which TcMEP monitoring had been used between 2010 and 2017. The upper limbs were used as the control. A true alert was recorded when there was a 50% or more loss of amplitude from the lower limbs with maintained upper limb signals. Patients with true alerts were identified and their case history analyzed. Results. Of the 299 cases reviewed, 279 (93.3%) had acceptable traces throughout and awoke with normal clinical neurological function. No patient with normal traces had a postoperative clinical neurological deficit. True alerts occurred in 20 cases (6.7%). The diagnoses of the alert group included nine cases of adolescent idiopathic scoliosis (AIS) (45%) and six of congenital scoliosis (30%). The incidence of deterioration based on diagnosis was 9/153 (6%) for AIS, 6/30 (20%) for congenital scoliosis, and 2/16 (12.5%) for spinal tuberculosis. Deterioration was much more common in congenital scoliosis than in AIS (p = 0.020). Overall, 65% of alerts occurred during rod instrumentation: 15% occurred during decompression of the internal apex in vertebral column resection surgery. Four alert cases (20%) awoke with clinically detectable neurological compromise. Conclusion. Surgeon-directed TcMEP monitoring has a 100% negative predictive value and allows early identification of physiological cord distress, thereby enabling immediate intervention. In resource constrained environments, surgeon-directed TcMEP is a viable and effective method of intraoperative spinal cord monitoring. Level of evidence: III. Cite this article: Bone Joint J 2021;103-B(3):547–552

Aims. COVID-19 necessitated abrupt changes in trauma service delivery. We compare the demographics and outcomes of patients treated during lockdown to a matched period from 2019. Findings have important implications for service development. Methods. A split-site service was introduced, with a COVID-19 free site treating the majority of trauma patients. Polytrauma, spinal, and paediatric trauma patients, plus COVID-19 confirmed or suspicious cases, were managed at another site. Prospective data on all trauma patients undergoing surgery at either site between 16 March 2020 and 31 May 2020 was collated and compared with retrospective review of the same period in 2019. Patient demographics, injury, surgical details, length of stay (LOS), COVID-19 status, and outcome were compared. Results. There were 1,004 urgent orthopaedic trauma patients (604 in 2019; 400 in 2020). Significant reductions in time to theatre and LOS stay were observed. COVID-19 positive status was confirmed in 4.5% (n = 18). The COVID-19 mortality rate was 1.8% (n = 7). Day-case surgery comprised 47.8% (n = 191), none testing positive for COVID-19 or developing clinically significant COVID-19 symptoms requiring readmission, at a minimum of 17 days follow-up. Conclusion. The novel split-site service, segregating suspected or confirmed COVID-19 cases, minimized onward transmission and demonstrated improved outcomes regarding time to surgery and LOS, despite altered working patterns and additional constraints. Day-surgery pathways appear safe regarding COVID-19 transmission. Lessons learned require dissemination and should be sustained in preparation for a potential second wave or, the return of a “normal” non-COVID workload. Cite this article: Bone Joint Open 2020;1-9:568–575