Aims. Acetabular fractures are associated with long-term morbidity. Our prospective cohort study sought to understand the recovery trajectory of this injury over five years. Methods. Eligible patients at a level I trauma centre were recruited into a longitudinal registry of surgical acetabular fractures between June 2004 and August 2019. Patient-reported outcome measures (PROMs), including the 36-Item Short Form Health Survey (SF-36) physical component summary (PCS), were recorded at baseline pre-injury recall and six months, one year, two years, and five years postoperatively. Comparative analyses were performed for elementary and associated fracture patterns. The proportion of patients achieving minimal clinically important difference (MCID) was determined. The rate of, and time to, conversion to total hip arthroplasty (THA) was also established. Results. We recruited 251 patients (253 fractures), with a 4:1 male to female ratio and mean age of 46.1 years (SD 16.4). Associated fracture patterns accounted for 56.5% of fractures (n = 143). Trajectory analysis showed all timepoints had significant disability versus baseline, including final follow-up (p < 0.001). Elementary fractures had higher SF-36 PCS at six months (p = 0.023) and one year (p = 0.007) compared to associated fractures, but not at two years (p = 0.135) or five years (p = 0.631). The MCID in SF-36 PCS was observed in 37.3% of patients (69/185) between six months and one year, 26.9% of patients (39/145) between one and two years, and 23.3% of patients (20/86) between two and five years, highlighting the long recovery potential of these injuries. A significant proportion of patients failed to attain the MCID after five years (38.1%; 40/105). Conversion to THA occurred in 13.1% of patients (11/110 elementary and 22/143 associated fractures). Approximately two-thirds of THAs (21/33 patients; 63.6%) were performed within two years of index surgery. Conclusion. Acetabular fractures significantly impact physical function. Recovery trajectory is often elongated beyond one year, with two-thirds of our patients displaying persistent clinically relevant long-term disability. Cite this article: Bone Joint J 2024;106-B(1):69–76

Aims. Total hip arthroplasty (THA) is a common procedure to address pain and enhance function in hip disorders such as osteoarthritis. Despite its success, postoperative patient recovery exhibits considerable heterogeneity. This study aimed to investigate whether patients follow distinct pain trajectories following THA and identify the patient characteristics linked to suboptimal trajectories. Methods. This retrospective cohort study analyzed THA patients at a large academic centre (NYU Langone Orthopedic Hospital, New York, USA) from January 2018 to January 2023, who completed the Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity questionnaires, collected preoperatively at one-, three-, six-, 12-, and 24-month follow-up times. Growth mixture modelling (GMM) was used to model the trajectories. Optimal model fit was determined by Bayesian information criterion (BIC), Vuong-Lo-Mendell-Rubin likelihood ratio test (VLMR-LRT), posterior probabilities, and entropy values. Association between trajectory groups and patient characteristics were measured by multinomial logistic regression using the three-step approach. Results. Among the 1,249 patients, a piecewise GMM model revealed three distinct pain trajectory groups: 56 patients (4.5%) in group 1; 1,144 patients (91.6%) in group 2; and 49 patients (3.9%) in group 3. Patients in group 2 experienced swift recovery post-THA and minimal preoperative pain. In contrast, groups 1 and 3 initiated with pronounced preoperative pain; however, only group 3 exhibited persistent long-term pain. Multinomial regression indicated African Americans were exceedingly likely to follow trajectory groups 1 (odds ratio (OR) 2.73) and 3 (OR 3.18). Additionally, odds of membership to group 3 increased by 12% for each BMI unit rise, by 19% for each added postoperative day, and by over four if discharged to rehabilitation services (OR 4.07). Conclusion. This study identified three distinct pain trajectories following THA, highlighting the role of individual patient factors in postoperative recovery. This emphasizes the importance of preoperatively addressing modifiable risk factors associated with suboptimal pain trajectories, particularly in at-risk patients. Cite this article: Bone Jt Open 2024;5(3):174–183

Aims. Although total knee arthroplasty (TKA) is a highly successful procedure, about 20% of patients remain dissatisfied postoperatively. This proportion is derived from dichotomous models of the assessment of surgical success or failure, which may not reflect the spectrum of outcomes. The aim of this study was to explore differing responses to surgery, and assess whether there are distinct groups of patients with differing patterns of outcome. Methods. This was a secondary analysis of a UK multicentre TKA longitudinal cohort study. We used a group-based trajectory modelling analysis of Oxford Knee Score (OKS) in the first year following surgery with longitudinal data involving five different timepoints and multiple predictor variables. Associations between the derived trajectory groups and categorical baseline variables were assessed, and predictors of trajectory group membership were identified using Poisson regression and multinomial logistic regression, as appropriate. The final model was adjusted for sociodemographic factors (age, sex) and baseline OKS. Results. Data from 731 patients were available for analysis. Three distinct trajectories of outcome were identified: “poor” 14.0%, “modest” 39.1%, and “good” 46.9%. The predicted probability of membership for patients assigned to each trajectory group was high (0.89 to 0.93). Preoperative mental, physical health, and psychosocial factors determined which trajectory is likely to be followed. Poor responders were characterized by a comparatively small number of factors, preoperative expectations of pain and limitations, coping strategies, and a lower baseline physical health status, while the good responders were characterized by a combination of clinical, psychosocial, mental health, and quality of life factors. Conclusion. We identified three distinct response trajectories in patients undergoing TKA. Controlling for baseline score, age, and sex, psychosocial factors such as expectations of pain and limited function and poor coping strategies differentiated the trajectory groups, suggesting a role for preoperative psychosocial support in optimizing the clinical outcome. Cite this article: Bone Joint J 2021;103-B(6):1096–1102

Introduction. Knee arthroplasty (KA) is a highly effective surgical procedure. However, research suggests that a considerable number of patients continue to experience substantial pain and functional loss following surgical recovery. We aimed to estimate pain and function outcome trajectories for persons undergoing KA depicting the outcome, the relationship between the pain and function trajectory types, and pre-surgery predictors of trajectory type (i.e., good versus poor). Methods. Participants included 384 patients who took part in the Knee Arthroplasty Skills Training (KASTPain) clinical trial. Pain and function was assessed at 2-week pre- and 2-, 6-, and 12-month post-surgery using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain and Function Scales. Piecewise latent class growth models were used to estimate pain and function trajectories. Dumenci's latent kappa was used to estimate the chance-corrected agreement between pain and function trajectory types. Pre-surgery variables were used to predict trajectory types. Results. There was strong evidence for two trajectory types, labeled as good and poor, for both WOMAC pain and function scores. Model estimated rates of the poor trajectory type were 18% for both pain and function. Dumenci's latent kappa between pain and function trajectory types was 0.71 (95% CI: 0.61 – 0.80). Most pre-surgery variables were not significant predictors of the trajectory types. Conclusions. Among adults with moderate to severe pain catastrophizing undergoing KA, approximately one-fifth of patients continue to have persistent pain, poor function, or both, which is similar to the rate of poor reported outcomes in the TKA population overall. Although the poor pain and function trajectory types tend to go together within persons, a significant number of patients experience either poor pain or function but not both, suggesting heterogeneity among persons who do not fully benefit from KA. For figures, tables, or references, please contact authors directly

Previous studies describing drill trajectory for single incision distal biceps tendon repair suggest aiming ulnar and distal (Lo et al). This suggests that the starting point of the drill would be anterior and radial to the anatomic insertion of the distal biceps tendon. Restoration of the anatomic footprint may be important for restoration of normal strength, especially as full supination is approached. To determine the safest drill trajectory for preventing injury to the posterior interosseous nerve (PIN) when repairing the distal biceps tendon to the ANATOMIC footprint through a single-incision anterior approach utilising cortical button fixation. Through an anterior approach in ten cadaveric specimens, three drill holes were made in the radial tuberosity from the centre of the anatomic footprint with the forearm fully supinated. Holes were made in a 30º distal, transverse and 30º proximal direction. Each hole was made by angling the trajectory from an anterior to posterior and ulnar to radial direction leaving adequate bone on the ulnar side to accommodate an eight-millimetre tunnel. Proximity of each drill trajectory to the PIN was determined by making a second incision on the dorsum of the proximal forearm. A K-wire was passed through each hole and the distance between the PIN and K-wire measured for each trajectory. The PIN was closest to the trajectory K-wires drilled 30° distally (mean distance 5.4 mm), contacting the K-wire in three cases. The transverse drill trajectory resulted in contact with the PIN in one case (mean distance 7.6 mm). The proximal drill trajectory appeared safest with no PIN contact (mean distance 13.3 mm). This was statistically significant with a Friedman statistic of 15.05 (p value of 0.00054). When drilling from the anatomic footprint of the distal biceps tendon the PIN is furthest from a drill trajectory aimed proximally. The drill is aimed radially to minimise blowing out the ulnar cortex of the radius. For any reader inquiries, please contact . vansurgdoc@gmail.com

Introduction. From 2004 to 2015, elective lumbar fusions increased by 62% in the US. The largest increases were for among age 65 or older (139% in volume) and scoliosis (187%) [1]. Age is a well known factor of osteoporosis. The load-sharing may exceed the pedicular screws constructs in aging spine and lead to non-union and re-do. Surgical options may increase the screw purchase (e.g.: augmentation, extensions) at supplementary risks. Pedicular screw are known to cause vascular, nerve root or cord injuries. Facing these pitfalls, the surgeon's experience and rule of thumbs are the most deciding factors for the surgical planning. The aim of this study is to assess the accuracy of a patient specific tool, designed to plan a safe pedicular trajectory and to provide an intraoperative screw pullout strength estimate. Materials and Methods. Clinical QCT were taken for nine cadaveric spines (82 y. [61; 87], 6 females, 3 males). The experimental maximum axial pullout resistance (FMax) of twenty-seven pedicular screws inserted (nine T12, nine L4 and nine L5) was obtained as described in a previous study [2]. A custom 3D-WYSIWYG software simulated a medio-lateral surgical insertion technique in the QCTs coordinates reference, respecting the cortical walls. Repeatable density, morphometric and hardware parameters were recorded for each vertebrae. A statistical model was built to match predictive and experimental data. Preliminary results. Experimental FMax(N) were [104;953] (359 ±223). A further displacement of 1,81mm ±0,35 halved the experimental FMax. Predictive FMax(N) were [142;862] (359 ±220). A high positive correlation between experimental and predictive FMax was revealed (Pearson, ρ = 0.93, R2 = 0.87, p < .001, figure 1). Absolute differences ranged between 3N and 177N. Discussion. A high screw purchase in primary fixation is paramount to achieve spine surgical procedures (e.g.: kyphosis, scoliosis) and postoperative stability for vertebrae fusion. High losses of screw purchase by bone plastic deformation, begin with tiny pullouts. Theses unwanted intraoperative millimetric over-displacements are hard to avoid when monitoring at the same time tens of screws surrounded by bleedings. This advocates for including predictive FMax for each implantable pedicular screw in the surgical planning decision making process to prevent failures and assess risks. For the first time, this study presents an experimentally validated statistical model for FMax prediction with a safe trajectory definition tool, including patients’ vertebrae and hardware properties and referring to the patient's clinical 3D quantitative imagery. The model was able to differentiate between bone quality and vertebrae variations. More extensive model validation is currently ongoing to interface with robotics & navigation systems and to produce meshes for 3D printing of sterilizable insertion guides

Background:. Paley et al has developed the multiplier method for predicting leg length. It is a tool that is used clinically to predict leg length discrepancy. The method is also a way of comparing different populations, to identify differences in growth trajectory. This has been done by identifying the differing multipliers for girls and boys. However it has not been used to identify trends in populations separated by time. Tanner showed that in the first half of the twentieth century girls went from an average age of menarche of 15 in 1900, to 13 in 1970, how this has affected growth trajectory over the last 50 years has not been studied. Purpose:. The multiplier method is based on data collected in the 1950's by Anderson and Green, we aim to assess whether there has been a change in growth trajectory between this historical cohort and a contemporary European based cohort. Methods:. The Avon Longitudinal Study of Parents and Children of the 90s (ALSPAC) is a longitudinal cohort study of children recruited antenatally, and followed prospectively. Assessment of sub ischial leg length was made on clinical measurements. There were up to 8 measurements per patient, 2311 girls with a final age at assessment of greater than 15 years and 123 males with a final age of assessment of greater than 16 years were assessed. We used the multiplier method to assess the predicted final leg length and compared this with the actual leg length. Result:. There was no difference between the multiplier in girls, in the contemporary cohort and the historical cohort. The average age of menarche in the contemporary group was 12.7. In boys the data is limited, due to later growth and it is not possible to draw comparisons from this group. Conclusion:. This data provides good evidence that there has not been a significant change in growth trajectory in girls over the last 50 years. Significance:. Implications on the confidence with which we can use the multiplier method in this population

Different methods of lateral mass(LM) screw placement in the cervical spine have been described. In the axial plane, 30 degrees is the recommended angle to avoid neurovascular injury. The estimation of this angle remains arbitrary and operator dependant. To assess how accurately the lateral trajectory angle (LTA) for cervical LM screws is achieved by visual estimation amongst experienced spinal surgeons. A sawbone model of cervical spine with simulated lordosis was used. Five spinal consultants and five senior spinal fellows were asked to insert 1.6 mm K wires into lateral masses of C3 to C6 bilaterally to simulate screws. The LTA in transverse plane was measured using a customised protractor. Basic statistical analyses of all the data were obtained. Using all the angles derived, a virtual screw trajectory was drawn in the lateral plane, on a normal axial Computerised Tomography scan of cervical spine of an anonymous patient using PACS system. The overall mean LTA for the group was 25.15 degrees, that of the fellows 24.4 and consultants 26.2 degrees. Mean deviation from 30 degrees for fellows was 5.2 and 6.4 degrees for consultants. Overall standard deviation was 4.78, for fellows and consultants it was 3.3 and 5.8 respectively. Two episodes of vertebral artery injury occurred at 15 and 16 degrees with simulated angles on CT. A moderate variability in visual estimation of the trajectory angle exists even amongst experienced surgeons during insertion of cervical LM screws. An anatomical landmark would be useful to improve the reliability of the procedure

Aim: In sub-axial cervical vertebrae the lamina appears to project perpendicular to the ipsilateral pedicle axis, and forms a reliable trajectory for avoidance of vertebral artery injury in lateral mass (LM) screw placement: the aim is to confirm these observations. Material and Methods: 51 digital cervical spine CTs (255 vertebrae; 25 female 26 male; mean age 37.4 range:18–80). Exclusions: Severe degeneration, malformation, tumour, trauma. Measurement (axial view):. Angle of ipsilateral outer lamina cortex to pedicle axis. Virtual screw trajectory 2 mm from and parallel to the lamina was placed through the LM. Potential violation of the transverse foramen and LM width available for screw purchase was assessed. Results: Average lamina-pedicle angle (standard deviation):. Females: Right: C3–84.8°(2.6), C4–85.2°(3.1), C5–86.7°(3.3), C6–89.2°(2.5), C7–92.3°(2.4);. Left: C3–84.0°(3.1), C4–84.5°(3.9), C5–86.6°(3.7), C6–89.6°(2.6), C7–92.1°(2.3). No significant difference between males and females (P< 0.05). Violation of transverse foramen C3–C7: 0%. LM width (trajectory parallel to LM) in millimetres (standard deviation):. Males: Right: C3–5.5(0.7), C4–6.1(0.7), C5–6.8(0.8), C6–7.1(1.1), C7–6.1(1);. Left: C3–5.2(0.8), C4–5.9(0.8), C5–7(1.2), C6–7.3(1.1), C7–6.3(1.4). Females: Right: C3–5.3(0.8), C4–5.5(0.9), C5–6.6(1.2), C6–6.3(1.3), C7–5.4(1.4);. Left: C3–5.2(1), C4–5.7(1), C5–7.1(1.1), C6–6.5(1.3), C7–5.5(1.6). Conclusion: The angle formed by the lamina and ipsilateral pedicle ranges from 84° at C3 to 92° at C7. Although the angle is not exactly perpendicular at all levels as hypothesised, the lamina forms a useful reference plane for pedicle screw insertion in the sub-axial cervical spine. LM screws placed parallel to the lamina find sufficient LM width and are highly unlikely to injure the vertebral artery in bi-cortical placement. This technique appears favourable over conventional 30° LM placement. Ethics approval: None needed. Interest Statement: None

Aims

This study describes the variation in the annual volumes of revision hip arthroplasty (RHA) undertaken by consultant surgeons nationally, and the rate of accrual of RHA and corresponding primary hip arthroplasty (PHA) volume for new consultants entering practice.

Introduction. Low serum Vitamin D (VitD) levels are often found in patients being investigated for Total Knee Arthroplasty (TKA). VitD deficiency is associated with poor pre/post-operative functional scores and higher rate of complications. Studies report VitD as an important modifiable risk factor to improve outcomes post TKA. Aim. Aim of our study was 1) To examine the trajectory of VitD in TKA patients over 2 weeks, which included VitD sufficient and deficient patients who were supplemented orally or intramuscularly (IM) for comparision. 2) To compare early (2weeks) functional recovery in VitD sufficient and deficient patients. Material & Methods. We prospectively enrolled patients undergoing primary TKA by a single surgeon. Based on preoperative VitD levels (25OH VitD ≥30 being sufficient or <30 ng/mL being deficient) and means of supplementation(none, IM or Oral Injection Arachitol, Cholecalciferol IP 6,00,000 IU), we formed three groups: Group A (VitD sufficient, no supplementation); Group B (VitD deficient, IM supplementation); and Group C (VitD deficient, Oral supplementation). Study was approved by ethics committee. All patients gave informed consent and underwent TKA by same surgeon with uniform intra/post-operative protocols. VitD deficiency was supplemented orally/IM on the morning of surgery based on their randomization sequence. VitD levels (ng/mL) and outcome parameters of Flexion (degrees) and Timed up-and-go (TUG) test in seconds were assessed preoperatively and postoperatively on Day 3 and 14. 60 patients (20 per group) were enrolled. Demographics of all three groups were comparable. Results. VitD:. Group A:. Mean preoperative level of 42.3, fell to mean 40.4 by Day 3 (p < 0.001), and further to mean 38.9 by Day 14 (p<0.001). 6 and 4 patients became VitD deficient by Day 3 and Day 14 respectively. Group B:. Mean preoperative level of 21.5 rose to 31.2 by Day 3 (p=0.06), and further to 36.9 by Day 14 (p=0.001). 7 and 11 patients became sufficient by Day 3 and Day 14 respectively. Group C:. Mean preoperative level of 20.2 rose to mean 69.9 by Day 3 (p<0.001) and to a mean of 67.2 by Day 14 (p < 0.001). 19 and 20 patients became sufficient by Day 3 and Day 14 respectively. Outcome. Flexion:. Preoperative Flexion in Groups A, B, C was 133, 129 & 125 respectively (p=0.5). Day 3 Flexion was 88, 84 & 83 (p=0.2); Day 14 Flexion was 99, 90 & 95 (p=0.013) respectively. Posthoc Schaffe test showed statistical significance (p<0.05) only between Group A (99) and Group B (90) at Day 14. This indicated better flexion achieved in VitD sufficient patients at 2 weeks than in deficient patients with IM supplementation. TUG Test. was 17.1, 14.1 & 14.7 preoperatively in Groups A, B, C (p=0.5); on Day 3, it was 52.5, 62.6 & 58.2 (p=0.07); on Day 14, it was 33, 38.8 & 37.8 (p=0.2) respectively. Day 3 TUG time was longest (62.6) in Group B and shortest (52.5) in Group A indicating that IM supplemented patients had poor function compared to sufficient group though without statistical significance (p=0.07) with numbers available. Conclusion. We found that VitD deficient patients can be rapidly supplemented on the morning of surgery. High dose oral VitD increased levels by Day 3, whereas IM VitD increased levels only by Day 14 which remained significantly lesser than oral group. Interestingly, about 25% of VitD sufficient patients who were not supplemented, became deficient postoperatively. Flexion achieved on Day 14 was significantly better with VitD sufficiency, compared to deficient patients treated with IM VitD. Significance. VitD deficiency can be rapidly corrected by high dose oral supplementation on the morning of surgery. Also, TKA can deplete VitD and can make VitD sufficient patients deficient as early as Day 3 post surgery. For figures, tables, or references, please contact authors directly

Background: Low bone mass in patients with adolescent idiopathic-scoliosis has been well reported in cross-sectional studies. No large-scale longitudinal-study has been conducted to track bone-mineral-density (BMD) trajectory in peripubertal AIS with varying scoliosis-severity. Aim: We evaluated the BMD trajectory and factors determining BMD accretion in AIS during peripubertal period. Method: One hundred and ninety-six newly diagnosed AIS girls with Cobb-angle > 100 and 122 healthy girls, aged 12–15 years were followed-up for two years. Weight, height, leg length, menarche and Cobb-angle were determined. Areal lumbar-spinal BMD (LSBMD) and femoral-neck BMD (FNBMD), and volumetric distal-tibial BMD (TiBMD) were evaluated by dual-energy-x-ray-absorptiometry and peripheral QCT respectively. BMD growth-models were fitted by multilevel modelling (mixed longitudinal design). Results: At baseline, 93% participants were pre-menarchial or within three years of menarche. Average Cobb-angles at baseline and subsequent follow-ups were 260, 230 and 260 respectively. TiBMD of AIS (moderate- and severe-severity) was significantly lower than the controls from 13–16 years (ANOVA, P< 0.05). Posthoc-test showed that TiBMD of severe-AIS was lower than moderate-AIS at 15–16 years (P< 0.05). LSBMD accrual was significantly lower among AIS (moderate- and severe-severity) than the controls from age 13–17 years (ANOVA, P< 0.05). FNBMD of AIS (moderate- and severe-severity) was lower than the controls at 15 years (ANOVA, P< 0.05). BMD trajectories of individuals differed inter-personally and intra-personally over time and that BMD growth followed a curvilinear pattern. The rates of BMD accretion reduced with retarded growth across peripubertal-period. Weight and height were significant time-varying predictors on BMD growth. BMD of AIS was persistently lower than the healthy girls throughout the study (P< 0.05). Conclusions: This large-scale longitudinal study in AIS girls with moderate to severe-curve-severity showed for the first time that both the volumetric and areal BMD were persistently lower when compared to the age-matched healthy girls throughout 12–17 years. AIS with more severe curve-severity were found to have much lower BMD throughout the peripubertal period. Promotion of a higher bone-mass is important for AIS to modify scoliosis-progression and to achieve peak bone mass in order to reduce the risk of osteoporosis later in life

Purpose: Bone mineral density (BMD) is an important factor in the performance of orthopaedic instrumentation both in and ex-vivo, and until now, there has not existed a reliable technique for determining BMD at the precise location of such hardware. This paper describes such a technique using cadaveric human sacra as a model. Method: Nine fresh-frozen sacra had solid and hollow titanium screw placed into the S1 pedicles from a posterior approach. High-resolution micro-computed tomography (CT) was performed on each specimen before and after screw placement. All images were reconstructed with an isotropic spatial resolution of 0.308 mm, reoriented, and the pre-screw and post-screw scans were registered and transformed using a six-degree rigid-body transformation matrix. Once registered, two points, corresponding to the center of the screw at the cortex and at the screw tip, were determined in each scan. These points were used to generate cylindrical regions of interest (ROI) with the same trajectory and dimensions as the screw. BMD measurements were obtained within each of the ROI in the pre-screw scan. To examine the effect of artefact on BMD measurements around the titanium screws, annular ROI of 1 mm thickness were created expanding from the surface of the screws, and BMD was measured within each in both the pre-and post-screw scans. Results: The registration process was accurate, with an error of 0.2 mm. Four specimens were scanned five times with repositioning, and error in BMD measurements was ± 2%. BMD values in the cylindrical ROI corresponding to screw trajectories were not statistically different from side to side of each specimen (p = 0.23). Artefact-related differences in BMD values followed an exponential decay curve as distance from the screws increased, approaching a low value of approximately 20 mg HA/cc, but not disappearing completely. Conclusion: CT in the presence of metal creates artefact, making measured BMD values near implants unreliable. This technique is accurate for determination of BMD, non-destructive, and eliminates the problem of this metal artefact through the use of co-registration of a pre- and post-screw scan. This technique has applications both in-vitro and in-vivo

Introduction:

Paley et al has developed a multiplier method for calculating both leg length and total height. In the development of this algorithm, they evaluated the effect of factors including bone age and sex. They established that sex had a significant impact, but adjusting for bone age did not improve accuracy. Bone age and menarche have been shown to improve other height prediction models.

Aims. To determine the trajectories of patient reported pain and functional disability over five years following total hip arthroplasty (THA) or total knee arthroplasty (TKA). Methods. A prospective, longitudinal cohort sub-study within the National Joint Registry (NJR) was undertaken. In all, 20,089 patients who underwent primary THA and 22,489 who underwent primary TKA between 2009 and 2010 were sent Oxford Hip Score (OHS) and Oxford Knee Score (OKS) questionnaires at six months, and one, three, and five years postoperatively. OHS and OKS were disaggregated into pain and function subscales. A k-means clustering procedure assigned each patient to a longitudinal trajectory group for pain and function. Ordinal regression was used to predict trajectory group membership using baseline OHS and OKS score, age, BMI, index of multiple deprivation, sex, ethnicity, geographical location, and American Society of Anesthesiologists grade. Results. Data described two discrete trajectories for pain and function: ‘level 1’ responders (around 70% of cases) in whom a high level of improvement is sustained over five years, and ‘level 2’ responders who had sustained improvement, but at a lower level. Baseline patient variables were only weak predictors of pain trajectory and modest predictors of function trajectory. Those with worse baseline pain and function tended to show a greater likelihood of following a ‘level 2’ trajectory. Six-month patient-reported outcome measures data reliably predicted the class of five-year outcome trajectory for both pain and function. Conclusion. The available preoperative patient variables were not reliable predictors of postoperative pain and function after THA and TKA. Reviewing patient outcomes at six months postoperatively is a reliable indicator of outcome at five years. Cite this article: Bone Joint J 2021;103-B(6):1111–1118

Aims. This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up. Methods. From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed. Results. At 15 years, 28 patients were lost to follow-up (6.1%) and 221 patients (51.9%) had died, with the mean age of the remaining cohort reducing by four years. PROMs response rates among surviving patients were: one-year 63%; five-year 72%; ten-year 94%; and 15-year 59%. OKS and SF-12 scores changed significantly over 15 years (p < 0.001). The mean improvement in OKS was 18.8 (95% confidence (CI) 16.7 to 19.0) at one year. OKS peaked at five years (median 43 years) declining thereafter (p < 0.001), though at 15 years it remained 17.5 better than preoperatively. Age and sex did not alter this trajectory. A quarter of patients experienced a clinically significant decline (≥ 7) in OKS from five to ten years and from ten to 15 years. The SF-12 physical component score displayed a similar trajectory, peaking at one year (p < 0.001). Patient satisfaction was 88% at one, five, and ten years, and 94% at 15 years. In all, 15-year Kaplan-Meier survival was 97.6% (95% CI 96.0% to 99.2%) for any revision, and 98.9% (95% CI 97.9% to 99.9%) for aseptic revision. Conclusion. Improvements in PROMs were significant and maintained following single radius TKA, with OKS peaking at five years, and generic physical health peaking at one year. Patient satisfaction remained high at 15 years, at which point 2.4% had been revised. Cite this article: Bone Jt Open 2023;4(10):808–816

Aims. Proper preoperative planning benefits fracture reduction, fixation, and stability in tibial plateau fracture surgery. We developed and clinically implemented a novel workflow for 3D surgical planning including patient-specific drilling guides in tibial plateau fracture surgery. Methods. A prospective feasibility study was performed in which consecutive tibial plateau fracture patients were treated with 3D surgical planning, including patient-specific drilling guides applied to standard off-the-shelf plates. A postoperative CT scan was obtained to assess whether the screw directions, screw lengths, and plate position were performed according the preoperative planning. Quality of the fracture reduction was assessed by measuring residual intra-articular incongruence (maximum gap and step-off) and compared to a historical matched control group. Results. A total of 15 patients were treated with 3D surgical planning in which 83 screws were placed by using drilling guides. The median deviation of the achieved screw trajectory from the planned trajectory was 3.4° (interquartile range (IQR) 2.5 to 5.4) and the difference in entry points (i.e. plate position) was 3.0 mm (IQR 2.0 to 5.5) compared to the 3D preoperative planning. The length of 72 screws (86.7%) were according to the planning. Compared to the historical cohort, 3D-guided surgery showed an improved surgical reduction in terms of median gap (3.1 vs 4.7 mm; p = 0.126) and step-off (2.9 vs 4.0 mm; p = 0.026). Conclusion. The use of 3D surgical planning including drilling guides was feasible, and facilitated accurate screw directions, screw lengths, and plate positioning. Moreover, the personalized approach improved fracture reduction as compared to a historical cohort. Cite this article: Bone Jt Open 2024;5(1):46–52

Abstract. Aims. Whilst short and mid-term activity levels after a Total Knee Replacement (TKR) have been reported in the literature; there is an over simplification of the reporting and longer-term activity levels are unknown. The aim of this study was to map the long-term trajectories of patients’ physical activity levels postoperatively to identify meaningful subgroups and explore associations with preoperative variables. Methods. This was a secondary analysis of a single centre longitudinal cohortstudy using group-based trajectory modelling (GBTM) of the University of California, Los Angeles (UCLA) physical activity score over ten years. Multinomial logistic regression models (both adjusted and unadjusted) were used to test associations between preoperative variables and trajectory group membership. Results. 266 of the 904 eligible patients were recruited (29%). Data from 260 patients was available for analysis. Four trajectory groups were identified with good fit of the model (average posterior probability 0.79 to 0.93). Of the four groups, the two more active groups had a peak activity level between two-three years postoperatively; the less active groups had a peak activity level at between three months and one year. Preoperative UCLA, participation in sports in the three years prior to surgery and male gender showed trends towards association with a higher activity group. Conclusions. Four trajectory groups were identified giving a more detailed understanding of temporal trends in physical activity levels post TKR. There was weak evidence to show an association between patient expectation, preoperative UCLA score and participation in sports in the prior three years and group membership

The purpose of this study is to evaluate risk factors for distal construct failure (DCF) in posterior spinal instrumented fusion (PSIF) in adolescent idiopathic scoliosis (AIS). We observed an increased rate of DCF when the pedicle screw in the lowest instrumented vertebra (LIV) was not parallel to the superior endplate of the LIV, however this has not been well studied in the literature. We hypothesise a more inferiorly angled LIV screw predisposes to failure and aim to find the critical angle that predisposes to failure. A retrospective cohort study was performed on all patients who underwent PSIF for AIS at the Starship Hospital spine unit from 2010 to 2020. On a lateral radiograph, the angle between the superior endplate of the LIV was measured against its pedicle screw trajectory. Data on demographics, Cobb angle, Lenke classification, instrumentation density, rod protrusion from the most inferior screw, implants and reasons for revision were collected. Of 256 patients, 10.9% (28) required at least one revision. The rate of DCF was 4.6% of all cases (12 of 260) and 25.7% of revisions were due to DCF. The mean trajectory angle of DCF patients compared to all others was 13.3° (95%CI 9.2° to 17.4°) vs 7.6° (7° to 8.2°), p=0.0002. The critical angle established is 11°, p=0.0076. Lenke 5 and C curves, lower preoperative Cobb angle, titanium only rod constructs and one surgeon had higher failure rates than their counterparts. 9.6% of rods protruding less than 3mm from its distal screw disengaged. We conclude excessive inferior trajectory of the LIV screw increases the rate of DCF and a screw trajectory greater than 11° predisposes to failure. This is one factor that can be controlled by the surgeon intraoperatively and by avoiding malposition of the LIV screw, a quarter of revisions can potentially be eliminated

The February 2023 Hip & Pelvis Roundup. 360. looks at: Total hip arthroplasty or internal fixation for hip fracture?; Significant deterioration in quality of life and increased frailty in patients waiting more than six months for total hip or knee arthroplasty: a cross-sectional multicentre study; Long-term cognitive trajectory after total joint arthroplasty; Costal cartilage grafting for a large osteochondral lesion of the femoral head; Foley catheters not a problem in the short term; Revision hips still a mortality burden?; How to position implants with a robotic arm; Uncemented stems in hip fracture?