Although nonunions are among the most common complications after long-bone fracture fixation, the definition of fracture nonunion remains controversial and varies widely. The aim of this study was to identify the definitions and diagnostic criteria used in the scientific literature to describe nonunions after long-bone fractures. A comprehensive literature search was performed in PubMed, Cochrane Library, Web of Science, and Embase. Prospective clinical studies, in which adult long-bone fracture nonunions were investigated as main subject, were included in this analysis. Data on nonunion definitions described in each study were extracted and collected in a database. Although 148 studies met the inclusion criteria, only 50% (74/148) provided a definition for their main study subject. Nonunion was defined in these studies based on time-related criteria in 85% (63/74), on radiographic criteria in 62% (46/74), and on clinical criteria in 45% (33/74). A combination of clinical, radiographic and time-related criteria for definition was found in 38% (28/74). The time interval between fracture and the time point when authors defined an unhealed fracture as a nonunion showed considerable heterogeneity, ranging from three to twelve months. In the current orthopaedic literature, we found a lack of consensus with regard to the definition of long-bone nonunions. Without valid and reliable definition criteria for nonunion, standardization of diagnostic and treatment algorithms as well as the comparison of clinical studies remains problematic. The lack of a clear definition emphasizes the need for a consensus-based approach to the diagnosis of fracture nonunion centred on clinical, radiographical and time-related criteria.

Background and purpose: A new periprosthetic joint infection (PJI) definition has recently been proposed by the European Bone and Joint Infection Society (EBJIS). The goals of this paper are to evaluate its diagnostic accuracy and compare it with previous definitions and to assess its accuracy in preoperative diagnosis.Patients and methods: We retrospectively evaluated a multicenter cohort of consecutive revision total hip and knee arthroplasties. Cases with minimum required diagnostic workup were classified according to EBJIS, 2018 International Consensus Meeting (ICM 2018), Infectious Diseases Society of America (IDSA), and modified 2013 Musculoskeletal Infection Society (MSIS) definitions. 2 years’ minimum follow-up was required to assess clinical outcome.Results: Of the 472 cases included, PJI was diagnosed in 195 (41%) cases using EBJIS; 188 (40%) cases using IDSA; 172 (36%) using ICM 2018; and 145 (31%) cases using MSIS. EBJIS defined fewer cases as intermediate (5% vs. 9%; p = 0.01) compared with ICM 2018. Specificity was determined by comparing risk of subsequent PJI after revision surgery. Infected cases were associated with higher risk of subsequent PJI in every definition. Cases classified as likely/confirmed infections using EBJIS among those classified as not infected in other definitions showed a significantly higher risk of subsequent PJI compared with concordant non-infected cases using MSIS (RR = 3, 95% CI 1–6), but not using ICM 2018 (RR = 2, CI 1–6) or IDSA (RR = 2, CI 1–5). EBJIS showed the highest agreement between pre-operative and definitive classification (k = 0.9, CI 0.8–0.9) and was better at ruling out PJI with an infection unlikely result (sensitivity 89% [84–93], negative predictive value 90% [85–93]).Conclusion: The newly proposed EBJIS definition emerged as the most sensitive of all major definitions. Cases classified as PJI according to the EBJIS criteria and not by other definitions seem to have increased risk of subsequent PJI compared with concordant non-infected cases. EBJIS classification is accurate in ruling out infection preoperatively.

The direct anterior approach (DAA) is increasingly popular for hip replacement. However, the small incision and the location near to the groin might increase the risk of periprosthetic joint infection (PJI). We asked the questions (i) whether there is an increased risk of infection for this approach, and (ii) whether the spectrum of microorganisms differs between patients with DAA and those with lateral transgluteal approach (LAT). All patients operated between 08/2006 and 12/2013 were followed prospectively in an in house register. The DAA was introduced as routine in 02/2009 at our hospital. Patients with primary elective hip replacement without previous operations were included. Follow-up was scheduled after 6, 12 weeks and 1, 2 years. PJI was defined according to standardized criteria. One thousand one hundred four patients were studied, 700 were operated with DAA and 404 with LAT. No patient was lost to follow-up. PJI was diagnosed in 23/1104 (2.1 %) patients, 16 (2.3 %) in the group with DAA, and 7 (1.7 %) in the group with LAT. Patients with infection had a higher BMI (p < 0.001) and a higher ASA score (p < 0.001). Only patients with the DAA had exogenous PJI caused by gramnegative bacilli (35.7 % vs 0 %, p = 0.26). In the DAA-group, the fraction of patients with polymicrobial infection was somewhat higher than in the LAT-group (50 % vs 33 %, P = 0.64). There was no increased risk of infection for the DAA.

It has been shown that the outcome of a DAIR (debridement, antimicrobial therapy, and implant retention) procedure depends on multiple factors (e.g. infection type, host factors, clinical presentation, condition of surrounding soft tissue, causing pathogen, surgical technique, antimicrobial therapy); therefore, adequate patient selection is key for DAIR success. In this position paper, we discuss the most relevant factors influencing the outcome and define indications, contraindications, and risk factors for a DAIR procedure based on the most robust and most recently published data. Furthermore, we discuss the surgical technique in combination with systemic antimicrobial therapy in patients undergoing a DAIR procedure. This position paper may help reduce reinfection rates as well as the physical, psychological, and economic burden associated with periprosthetic joint infection (PJI). We believe that a reasonable outcome can be achieved with careful patient selection, a dedicated multidisciplinary team, and an appropriate surgical technique and antimicrobial therapy.

Inertial measurement units (IMUs) are commonly used for gait assessment, yet their potential for quantifying improvements in gait function and patterns after total hip arthroplasty (THA) has not been fully explored. The primary aim of this study was to compare spatiotemporal parameters and sagittal plane kinematic patterns of patients with hip osteoarthritis (OA) before and after THA, and to asymptomatic controls. The secondary aim was to assess the association between dynamic hip range of motion (ROM) during walking and the Hip Osteoarthritis Outcome Scores (HOOS). Twenty‐four patients with hip OA and 24 matched asymptomatic controls completed gait analyses using the RehaGait® sensor system. Patients were evaluated pre‐ and 1 year postoperatively, controls in a single visit. Differences in kinematic data were analyzed using statistical parametric mapping, and correlations between dynamic hip ROM and HOOS were calculated. Walking speed and stride length significantly increased (+0.08 m/s, p = 0.019; +0.06 m, p = 0.048) after THA but did not reach the level of asymptomatic controls (−0.11 m/s, p = 0.028; −0.14 m, p = 0.001). Preoperative hip and knee kinematics differed significantly from controls. After THA, they improved significantly and did not differ from controls. Dynamic hip flexion‐extension ROM correlated positively with all HOOS subscores (r > 0.417; p ≤ 0.001). The change in HOOS symptoms in patients was explained by the combination of baseline HOOS symptoms and change in dynamic hip ROM (r² = 0.748) suggesting that the additional information gained with IMU gait analysis helps to complement and objectify patient‐reported outcome measures pre‐ and postoperatively and monitor treatment‐related improvements.

Introduction In revision total hip arthroplasty (THA), the cancellous bone is normally completely removed out of the femoral canal during stem extraction. This situation is comparable to primary THA following the shape-closed concept, with some authors advocating to remove the metaphyseal cancellous bone to enhance press-fit stability (“French paradox”). The aim of this study was to investigate the long-term outcome, regarding survival and radiological results, of a cemented straight stem when used for revision THA and to compare these results to the results of the same stem in primary THA. Materials and methods 178 stem revisions performed between 01/1994 and 08/2008 using the Virtec straight stem were included. The cumulative incidence for re-revision was calculated using a competing risk model. Risk factors for re-revision of the stem were analyzed using an absolute risk regression model. Radiographs analyzed for osteolysis, debonding and subsidence had a minimum follow-up of 10 years. Results The cumulative incidence for re-revision due to aseptic loosening of the stem was 5.5% (95% CI, 2.9–10.2%) at 10 years. Aseptic loosening was associated with younger age, larger defect size and larger stem size. After a minimum 10-year follow-up, osteolysis was seen in 39 of 80 revision THA. Compared to the results in primary THA, the survival in revision THA with the same implant was inferior. Conclusions Cemented straight stems used for revision THA showed excellent long-term results regarding survivorship and radiological outcome. This stem therefore offers a valuable and cost-effective option in revision THA.