Introduction. Acetabular bone defects are still challenging to quantify. Numerous classification schemes have been proposed to categorize the diverse kinds of defects. However, these classification schemes are mainly descriptive and hence it remains difficult to apply them in pre-clinical testing, implant development and pre-operative planning. By reconstructing the native situation of a defect pelvis using a Statistical Shape Model (SSM), a more quantitative analysis of the bone defects could be performed. The aim of this study is to develop such a SSM and to validate its accuracy using relevant clinical scenarios and parameters. Methods. An SSM was built on the basis of segmented 66 CT dataset of the pelvis showing no orthopedic pathology. By adjusting the SSM's so called modes of shape variation it is possible to synthetize new 3D pelvis shapes. By fitting the SSM to intact normal parts of an anatomical structure, missing or pathological regions can be extrapolated plausibly. The validity of the SSM was tested by a Leave-one-out study, whereby one pelvis at a time was removed from the 66 pelvises and was reconstructed using a SSM of the remaining 65 pelvises. The reconstruction accuracy was assessed by comparing each original pelvis with its reconstruction based on the root-mean-square (RMS) surface error and five clinical parameters (center of rotation, acetabulum diameter, inclination, anteversion, and volume). The influence of six different numbers of shape variation modes (reflecting the degrees of freedom of the SSM) and four different mask sizes (reflecting different clinical scenarios) was analyzed. Results. The Leave-one-out study showed that the reconstruction errors decreased when the number of shape variation modes included in the SSM increased from 0 to 20, but remained almost constant for higher numbers of shape variation modes. For the SSM with 20 shape variation modes, the RMS of the reconstruction error increased with increasing mask size, whereas the other parameters only increased from Mask_0 to Mask_1, but remained almost constant for Mask_1, Mask_2 and Mask_3. Median reconstruction errors for Mask_1, Mask_2, and Mask_3 were approximately 3 mm in Center of Rotation (CoR) position, 2 mm in Diameter, 3° in inclination and anteversion, as well as 5 ml in volume. Discussion. This is the first study analyzing and showing the feasibility of a quantitative analysis of acetabular bone defects using a SSM-based reconstruction method in the clinical scenario of a defect or implant in both acetabuli and incomplete CT-scans. Validation results showed acceptable reconstruction accuracy, also for clinical scenarios in which less healthy bone remains. Further studies could apply this method on a larger number of defect pelvises to obtain quantitative measures of acetabular bone defects

The Department of Health and the Public Health Laboratory Service established the Nosocomial Infection National Surveillance Scheme in order to standardise the collection of information about infections acquired in hospital in the United Kingdom and provide national data with which hospitals could measure their own performance. The definition of superficial incisional infection (skin and subcutaneous tissue), set by the Center for Disease Control (CDC), should meet at least one of the defined criteria which would confirm the diagnosis and determine the need for specific treatment. We have assessed the interobserver reliability of the criteria for superficial incisional infection set by the CDC in our current practice. The incisional site of 50 patients who had an elective primary arthroplasty of the hip or knee was evaluated independently by two orthopaedic clinical research fellows and two orthopaedic ward sisters for the presence or absence of surgical-site infection. Interobserver reliability was assessed by comparison of the criteria for wound infection used by the four observers using kappa reliability coefficients. Our study demonstrated that some of the components of the current CDC criteria were unreliable and we recommend their revision

A commonly misunderstood principle in medical literature is statistical significance. Often, statistically non-significant or negative results are thought to be evidence for equivalence; mistakenly validating treatment modalities and putting patients at risk. This study examines the prevalence of misinterpretation of negative results of superiority trials in orthopaedic literature and outlines the need for a non-inferiority or equivalence research design. Four orthopaedic journals – Journal of Paediatric Orthopaedics A, Journal of Bone and Joint Surgery American Volume, Journal of Arthroplasty and Journal of Shoulder and Elbow Surgery – were hand searched to identify all randomised control trials (RCTs) published within the time periods 2002–2003, 2007–2008 and 2012–2013. The identified RCTs were read and classified by study methodology, results obtained, and interpretation of results. A total of 237 RCTs were identified. When analysing the primary outcomes, 117 (49.4%) studies yielded negative results and 120 (50.8%) yielded positive results. Out of the 237 articles, 231 (97.5%) used superiority methodology and 6 (2.5%) used non-inferiority or equivalence methodology. Of the 231 studies that used superiority methodology, 115 (49.8%) obtained negative results; and 45 (39.1%) of those misinterpreted the negative results for equivalence. While no statistical differences were seen, there was an upward trend in utilising non-inferiority and equivalence methodologies over time. Given the frequency of misinterpreted negative results, there is an evident need for a more appropriate research methodology that shows equivalence of treatment methods. A non-inferiority or equivalence study design can address orthopaedic clinical dilemmas more suitably when trying to show one treatment is no worse or is equal to another treatment. Regarding orthopaedic treatment modalities as equivalent when studies show negative statistical results can be detrimental to patients and their clinical outcomes. A non-inferiority methodology can be used to accurately depict no difference between treatment methods rather than attempting to show one treatment method as superior

Background. The National Institute for Health and Clinical Effectiveness recommends both low molecular weight heparin (LMWH) and Rivaroxaban for venous thromboembolic (VTE) prophylaxis following lower limb arthroplasty. Despite evidence in the literature that suggests Rivaroxaban reduces VTE events, there are emerging concerns from the orthopaedic community regarding an increase in wound complications following its use. Methods. Through the orthopaedic clinical directors forum, Trusts replacing LMWH with Rivaroxaban for lower limb arthroplasty thromboprophylaxis during 2009 were identified. Prospectively collected Hospital episode statistics (HES) data was then analysed for these units so as to determine rates of 90-day symptomatic deep venous thrombosis (DVT), pulmonary embolism (PE), major bleed (cerebrovascular accident or gastrointestinal haemorrhage), all-cause mortality, and 30-day wound infection and readmission rates before and after the change to Rivaroxaban. 2752 patients prescribed Rivaroxaban following TKR or THR were compared to 10358 patients prescribed LMWH. Data was analysed using odds ratios (OR). Results. There were significantly more wound infections in the Rivaroxaban group (3.85% vs. 2.81%, OR=0.72; 95% CI 0.58–0.90). There were no significant differences between the two groups for PE (OR=1.52; 0.77–2.97), major bleed (OR=0.73; 0.48–1.12), all-cause mortality (OR=0.93; 0.46–1.87) and re-admission rate (OR=1.21; 0.88–1.67). There were significantly fewer symptomatic DVTs in the Rivaroxaban group (0.91% vs. 0.36%, OR=2.51; 1.30–4.82). Discussion. This study is the first to describe the real impact of the use of Rivaroxaban in the NHS. When compared with LMWH in lower limb arthroplasty patients, there were fewer DVTs in the Rivaroxaban group. However, wound infection rates were significantly higher following Rivaroxaban use whilst providing no reduction in symptomatic PE or all-cause mortality

The study aimed to determine how well recorded pain levels and range of motion relate to patients' reported levels of functional ability/disability pre- and post- total hip arthroplasty. Range of motion (ROM), Oxford Hip Score (OHS) and Self-Report Harris Hip Score (HHS) were recorded pre-operatively and 3 months post-total hip arthroplasty. Pearson's correlation coefficients were calculated to determine the strength of the relationships both pre- and post-operatively between ROM (calculated using the HHS scoring system) and scores on OHS and HHS and response relating to pain from the questionnaires (question 1 HHS and questions 1, 6, 8, 10, 11 and 12 of OHS) and overall scores. Only weak relationships were found between ROM and HHS pre- (r = 0.061, n = 99, p = 0.548) and post-operatively (r = 0.373, n = 66, p = 0.002). Similar results were found for OHS, and when ROM was substituted for flexion range. In contrast, strong correlations were found between OHS pain component and HHS pre- (r = -0.753, n = 107, p<0.001) and post-operatively (r = -0.836, n = 87, p<0.001). Strong correlations were also found between the OHS pain component correlated with the HHS functional component only (HHS with score for questions relating to pain deducted) pre- (r = -0.665, n = 107, p<0.001) and post-operatively (r = -0.688, n = 87, p<0.001). Similar results were found when the HHS pain component was correlated with OHS. In orthopaedic clinical practice ROM is routinely used to assess the success or failure of arthroplasty surgery. These results suggest that this should not be done. Instead, asking the patient the level of pain that they are experiencing may be a good determinant of level of function. The results of this study may aid the development of arthroplasty scoring systems which better assess patients' functional ability

Background. Venous thromboembolism deterrent (TED) stockings are recommended for all orthopaedic patients. Clinical evidence supporting their use is limited and the risk of DVT increases four-fold if pressure gradients are reversed. This study aims to investigate the efficacy of TED stockings and their application using pressure gradients as the outcome measure. Methods. We audited TED stockings over two discrete periods. In the first, cases were assessed for sizing, cutting in and tolerance. In the second we added pressure measurements along the saphenous vein; before and 2 and 3 days after surgery. Between the 2 series, a more rigorous sizing and re-sizing protocol was implemented. Results. In the first period, 80% of TED stockings were incorrectly sized, 48% cut in and compliance was 60%. In the second period, 34% of stockings were incorrectly sized, 20% cut in and compliance was 93%. Reverse gradients were observed in 21% of patients. Conclusion. Previous studies had shown reverse gradients in 54% of cases however we found significantly fewer (P=0.000). We attribute this to better fitting rather than quality of the stockings. The effectiveness of graduated compression stockings is more practice than device dependent

Significance. In ideal shared decision making (SDM), evidence-based treatment options, their likelihood of success, and the probability of adverse events is discussed with the patient. However, current SDM is fundamentally flawed because evidence for patient-specific treatment effectiveness and patient-specific adverse event risks is lacking. Observational outcome registries are better than randomized clinical trials for determining patient prognostic factors for outcomes and adverse events. No orthopaedic SDM clinical tools exist to predict patient-specific outcomes. Hypothesis: A patient-specific shared decision making tool can predict clinically significant outcomes and adverse events for total knee replacement (TKR) surgery. Methods. A web–based prospective observational outcome registry collects patient reported outcomes (PROs) for TKR surgery. The data set for TKR surgery includes: (1) European quality of life (EQ-5D); (2) Oxford Knee Score (OKS); (3) Lower Extremity Activity Scale (LEAS); and (4) Pain Likert Scale (PLS). A TKR outcome calculator predicts patient-specific functional outcome with a regression model using patient-specific pre-operative Oxford Knee Scores, diagnosis, co-morbidities, and demographics. Patient-specific joint infection relative risk is calculated using diagnosis, co-morbidities, and demographics. Functional outcomes are presented as minimum clinically important differences (MCIDs). MCID=σ. Δ. /2. Results. The MCID for the EQ-5D Health State Score (HSS) is 0.094 (0.000–1.000). The MCID for the EQ-5D Visual Analog Scale (VAS) is 9.1 (0–100). The MCID for the OKS is 4.45 (0–48). The MCID for the LEAS is 1.6 (1–18). The MCID for the PLS is 1.4 (0–10). Examples. (1) A 55-year-old white male with post-traumatic arthritis (ICD-9 716.16, BMI = 28.7, non-diabetic, recently quit smoking) has a pre-operative Oxford Knee Score of 10. His predicted outcome is 6.3 MCIDs and his relative risk of infection is 6.1 (4.4%) (Figure 1). He is expected to have an excellent outcome. His risk of infection can be reduced by using antibiotic-laden cement. Depending on the patient's preferences, he is an excellent candidate for a total knee replacement. (2) A 60-year-old white male with osteoarthritis (ICD-9 715.16, BMI = 25.0, non-diabetic, non-smoker) has a pre-operative Oxford Knee Score of 45. He has full thickness cartilage loss on his medial femoral condyle by MRI only. His predicted outcome is 0.67 MCIDs and his relative risk of infection is 1.9 (1.4%) (Figure 2). He is expected to have a poor outcome even though his risk of infection is low. Although he has full thickness cartilage loss on MRI, his pre-operative Oxford Knee Score of 45 demonstrates that he is very functional and has minimal opportunity for improving his knee function with a total knee replacement. He is a poor candidate for TKR surgery. Conclusions. The patient-specific SDM tool for TKR surgery can distinguish between excellent and poor surgical candidates when both patients meet radiographic criteria for surgery. The pre-operative Oxford Knee Score assesses knee function and/or disability. Patients with relatively high OKSs are less likely to achieve clinically significant improvements after total knee replacement surgery

Aims

The purpose of our study was to determine which groups of orthopaedic providers favour virtual care, and analyze overall orthopaedic provider perceptions of virtual care. We hypothesize that providers with less clinical experience will favour virtual care, and that orthopaedic providers overall will show increased preference for virtual care during the COVID-19 pandemic and decreased preference during non-pandemic circumstances.

Aims

Patient-reported outcome measures have become an important part of routine care. The aim of this study was to determine if Patient-Reported Outcomes Measurement Information System (PROMIS) measures can be used to create patient subgroups for individuals seeking orthopaedic care.

Virtual encounters have experienced an exponential rise amid the current COVID-19 crisis. This abrupt change, seen in response to unprecedented medical and environmental challenges, has been forced upon the orthopaedic community. However, such changes to adopting virtual care and technology were already in the evolution forecast, albeit in an unpredictable timetable impeded by regulatory and financial barriers. This adoption is not meant to replace, but rather augment established, traditional models of care while ensuring patient/provider safety, especially during the pandemic. While our department, like those of other institutions, has performed virtual care for several years, it represented a small fraction of daily care. The pandemic required an accelerated and comprehensive approach to the new reality. Contemporary literature has already shown equivalent safety and patient satisfaction, as well as superior efficiency and reduced expenses with musculoskeletal virtual care (MSKVC) versus traditional models. Nevertheless, current literature detailing operational models of MSKVC is scarce. The current review describes our pre-pandemic MSKVC model and the shift to a MSKVC pandemic workflow that enumerates the conceptual workflow organization (patient triage, from timely care provision based on symptom acuity/severity to a continuum that includes future follow-up). Furthermore, specific setup requirements (both resource/personnel requirements such as hardware, software, and network connectivity requirements, and patient/provider characteristics respectively), and professional expectations are outlined. MSKVC has already become a pivotal element of musculoskeletal care, due to COVID-19, and these changes are confidently here to stay. Readiness to adapt and evolve will be required of individual musculoskeletal clinical teams as well as organizations, as established paradigms evolve.

Cite this article: Bone Joint Open 2020;1-6:272–280.