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

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

Purpose. Factors contributing to chronic postoperative pain (CPOP) are poorly defined in young people and developmental considerations are poorly understood. With over 5 million children undergoing surgery yearly and 25% of adults referred to chronic pain clinics identifying surgery as the antecedent, there is a need to elucidate factors that contribute to CPOP in young people. The present study includes patients undergoing hip preservation surgery at a children's hospital. Methods. The HOOS and the SF-12 Health Survey were administered to 614 patients prior to surgery with 422 patients completing follow-up data (6-months, 1-year, and 2-years post-surgery). Examining baseline characteristics for those who completed follow-up versus those who did not, the only significant difference was that patients with more than one surgery were less likely to complete follow-up measures. Pain, quality of life, and functioning across time were examined using SAS PROC TRAJ procedure, a mixture model that estimates a regression model for each discrete group within the population. Longitudinal pain trajectories were empirically grouped. Baseline preoperative characteristics of age, gender, preoperative pain, quality of life, functioning, and mental health that could potentially distinguish trajectory groups were examined. Results. A three trajectory model (low pain, pain improvement, and high pain) emerged indicating three different treatment responders. Pain trajectory groups did not differ significantly on gender, presurgical age, BMI, prior hip surgery, surgical type, joint congruence, or Tönnis grade. The pain trajectory groups differed significantly from each other on presurgical pain, pain chronicity, quality of life, and functioning. Those in the high pain group and pain improvement group endorsed having presurgical depression at significantly higher rates and lower presurgical quality of life compared to those in the low pain group (p<.01). Similarly, those in the high pain group reported significantly worse functioning prior to surgery compared to the pain improvement group (p<.0001) and those in the low pain group (p<.0001). Conclusions. Chronic pain is a common problem and surgery can be a trigger. There may be a subset of hip preservation surgery patients who are predisposed to chronic pain independent of hip health. The results demonstrate the need for preoperative screening prior to hip preservation surgery. A prospective, interventional study to identify patients at risk for a poor pain trajectory is underway. Significance. This is the largest study to date to examine longitudinal pain, quality of life, and functioning trajectories for adolescent and young adults undergoing hip preservation surgery. Chronic pain is a serious public health concern, with the United States spending $19 billion annually on pain-related disability. Identifying predictors of poor long-term outcomes in adolescents and young adult samples with postoperative pain may prevent the development of chronic pain into adulthood as well as inform presurgical preparation and postsurgical care

Initial treatment of traumatic spinal cord injury remains as controversial in 2023 as it was in the early 19th century, when Sir Astley Cooper and Sir Charles Bell debated the merits or otherwise of surgery to relieve cord compression. There has been a lack of high-class evidence for early surgery, despite which expeditious intervention has become the surgical norm. This evidence deficit has been progressively addressed in the last decade and more modern statistical methods have been used to clarify some of the issues, which is demonstrated by the results of the SCI-POEM trial. However, there has never been a properly conducted trial of surgery versus active conservative care. As a result, it is still not known whether early surgery or active physiological management of the unstable injured spinal cord offers the better chance for recovery. Surgeons who care for patients with traumatic spinal cord injuries in the acute setting should be aware of the arguments on all sides of the debate, a summary of which this annotation presents.

Cite this article: Bone Joint J 2023;105-B(4):347–355.