Aims Postoperative range of movement (ROM) is an important measure of successful and satisfying total knee arthroplasty (TKA). Reduced postoperative ROM may be evident in up to 20% of all TKAs and negatively affects satisfaction. To improve ROM, manipulation under anaesthesia (MUA) may be performed. Historically, a limited ROM preoperatively was used as the key harbinger of the postoperative ROM. However, comorbidities may also be useful in predicting postoperative stiffness. The goal was to assess preoperative comorbidities in patients undergoing TKA relative to incidence of postoperative MUA. The hope is to forecast those who may be at increased risk and determine if MUA is an effective form of treatment. Methods Prospectively collected data of TKAs performed at our institution’s two hospitals from August 2014 to August 2018 were evaluated for incidence of MUA. Comorbid conditions, risk factors, implant component design and fixation method (cemented vs cementless), and discharge disposition were analyzed. Overall, 3,556 TKAs met the inclusion criteria. Of those, 164 underwent MUA. Results Patients with increased age and body mass index (BMI) had decreased likelihood of MUA. For every one-year increase in age, the likelihood of MUA decreased by 4%. Similarly, for every one-unit increase in BMI the likelihood of MUA decreased by 6%. There were no differences in incidence of MUA between component type/design or fixation method. Current or former smokers were more likely to have no MUA. Surprisingly, patients discharged to home health service or skilled nursing facility were approximately 40% and 70% less likely than those discharged home with outpatient therapy to be in the MUA group. MUA was effective, with a mean increased ROM of 32.81° (SD 19.85°; -15° to 90°). Conclusion Younger, thinner patients had highest incidence of MUA. Effect of discharge disposition on rate of MUA was an important finding and may influence surgeons’ decisions. Interestingly, use of cement and component design (constraint) did not impact incidence of MUA. Level of Evidence II: Prospective cohort study. Cite this article: Bone Joint J 2020;102-B(6 Supple A):66–72.

Background: Various lateral humeral condyle fracture (LHCF) classification systems have been in use since the 1950s, but limited research exists on their reliability. The most widely utilized, yet un-validated system is that of Jakob and colleagues. The purpose of the current study was to analyze the reliability of a modified Jakob classification system and its value in guiding treatment either with or without arthrography. Methods: Interrater and intrarater reliability studies were performed using radiographs and arthrograms from 32 LHCFs. Radiographs were presented to 3 pediatric orthopaedic surgeons and 6 pediatric orthopaedic surgery residents who were asked to classify the fractures according to a modified Jakob classification system, enunciate their treatment plan, and whether they would utilize arthrography. Classification was repeated within 2 weeks to assess intrarater reliability. The treatment plan using radiographs only and radiographs with arthrography were compared at both rating points. Results: The modified Jakob system had excellent interrater reliability using only radiographs with a kappa value of 0.82 and an overall agreement of 86%. The average kappa for intrarater reliability using only radiographs was 0.88 with a range of 0.79 to 1.00 and an average overall agreement of 91% with a range of 84% to 100%. Interrater and intrarater reliability was poorer using both radiographs and arthrography. On average, arthrography changed the treatment plan in 8% of cases. Conclusions: The modified Jakob classification system proved to be a reliable classification system for LHCFs, independent of arthrography, given the excellent free-marginal multirater kappa values. Level of Evidence: Level III—diagnostic.