Aims: The prevalence of combined abnormalities of femoral torsion (FT) and tibial torsion (TT) is unknown in patients with femoroacetabular impingement (FAI) and hip dysplasia. This study aimed to determine the prevalence of combined abnormalities of FT and TT, and which subgroups are associated with combined abnormalities of FT and TT. Methods: We retrospectively evaluated symptomatic patients with FAI or hip dysplasia with CT scans performed between September 2011 and September 2016. A total of 261 hips (174 patients) had a measurement of FT and TT. Their mean age was 31 years (SD 9), and 63% were female (165 hips). Patients were compared to an asymptomatic control group (48 hips, 27 patients) who had CT scans including femur and tibia available for analysis, which had been acquired for nonorthopaedic reasons. Comparisons were conducted using analysis of variance with Bonferroni correction. Results: In the overall study group, abnormal FT was present in 62% (163 hips). Abnormal TT was present in 42% (109 hips). Normal FT combined with normal TT was present in 21% (55 hips). The most frequent abnormal combination was increased FT combined with normal TT of 32% (84 hips). In the hip dysplasia group, 21% (11 hips) had increased FT combined with increased TT. The prevalence of abnormal FT varied significantly among the subgroups (p < 0.001). We found a significantly higher mean FT for hip dysplasia (31°; SD 15)° and valgus hips (42° (SD 12°)) compared with the control group (22° (SD 8°)). We found a significantly higher mean TT for hips with cam-type-FAI (34° (SD 6°)) and hip dysplasia (35° (SD 9°)) compared with the control group (28° (SD 8°)) (p < 0.001). Conclusion: Patients with FAI had a high prevalence of combined abnormalities of FT and TT. For hip dysplasia, we found a significantly higher mean FT and TT, while 21% of patients (11 hips) had combined increased TT and increased FT (combined torsional malalignment). This is important when planning hip preserving surgery such as periacetabular osteomy and femoral derotation osteotomy. Cite this article: Bone Joint J 2020;102-B(12):1636–1645.

Aims: The outcome of repeat septic revision after a failed one-stage exchange for periprosthetic joint infection (PJI) in total knee arthroplasty (TKA) remains unknown. The aim of this study was to report the infection-free and all-cause revision-free survival of repeat septic revision after a failed one-stage exchange, and to determine whether the Musculoskeletal Infection Society (MSIS) stage is associated with subsequent infection-related failure. Methods: We retrospectively reviewed all repeat septic revision TKAs which were undertaken after a failed one-stage exchange between 2004 and 2017. A total of 33 repeat septic revisions (29 one-stage and four two-stage) met the inclusion criteria. The mean follow-up from repeat septic revision was 68.2 months (8.0 months to 16.1 years). The proportion of patients who had a subsequent infection-related failure and all-cause revision was reported and Kaplan-Meier survival for these endpoints was determined. Patients were categorized according to the MSIS staging system, and the association with subsequent infection was analyzed. Results: At the most recent follow-up, 17 repeat septic revisions (52%) had a subsequent infection-related failure and the five-year infection-free survival was 59% (95% confidence interval (CI) 39 to 74). A total of 19 underwent a subsequent all-cause revision (58%) and the five-year all-cause revision-free survival was 47% (95% CI 28 to 64). The most common indication for the first subsequent aseptic revision was loosening. The MSIS stage of the host status (p = 0.663) and limb status (p = 1.000) were not significantly associated with subsequent infection-related failure. Conclusion: Repeat septic revision after a failed one-stage exchange TKA for PJI is associated with a high rate of subsequent infection-related failure and all-cause revision. Patients should be counselled appropriately to manage expectations. The host and limb status according to the MSIS staging system were not associated with subsequent infection-related failure. Cite this article: Bone Joint J 2022;104-B(3):386–393.

The British Editorial Society of Bone & Joint Surgery

Correct quantification of femoral version (FV) is crucial for femoroacetabular impingement (FAI) patients for diagnosis and for surgical planning. However, different measurement methods for FV and different normal values are confusing. The study aimed to investigate differences in FV measurement methods and to review normal FV. This retrospective comparative study investigated a total of 84 hips for FV measurement: 48 hips (asymptomatic patients) and 36 hips (asymptomatic volunteers) without hip pain. The 48 patients underwent computed tomography (CT) for another reason (mean age 63 ± 11 years) and most (39 hips, 81%) were male patients. The 36 hips reported no hip pain at the time of magnetic resonance imaging (MRI) (mean age 27 ± 7 years, 20 female patients, 56%). FV was measured on CT or MRI included pelvis and knee) and with the Murphy method. Mean FV for 48 hips was 22° (range 5–34°), and for 36 hips, it was 24° (7–44°). No significant differences were found between the two groups. For 39 male patients with CT scans, the mean FV was 21° (6–34°) and was significantly (P = 0.041) decreased compared to female patients (FV of 26°). For the review, 18 studies were compared that evaluated normal FV (total of 2275 hips) in the literature. Increasing values for normal FV were found for measurement methods with a more distal definition of the femoral neck axis: Normal values were reported for the Lee method (most proximal definition; 8–11°), Reikeras method (9–20°), Oblique/Jarrett method (9–15°), Tomczak method (22–24°), and Murphy method (most distal: 18–23°). Reported normal range of FV differs between measurement methods. This is important for patients with FAI/hip dysplasia undergoing hip preservation surgery (hip arthroscopy/femoral derotation osteotomy).

Vial coring describes the occurrence of small rubber particles, which are formed by needles when perforating vial stoppers. These particles may be aspirated along with the drug. Unconscious injection of rubber particles may increase the risks associated with intra-articular injections. This study aimed to analyze the frequency of this phenomenon and possibilities to avoid its occurrence. 800 vials of 2 ​mL, filled with sodium chloride, were divided into 4 groups (n ​= ​200 each). Aspiration through the rubber stopper was performed with a 18-Gauge needle and the fluid was ejected onto a 10 ​μm filter paper through a 18-Gauge needle (group one) and a 23-Gauge needle (group two). In group three a 23-Gauge needle was used for aspiration and ejection. In group four, aspiration was performed using 18-Gauge needles with implemented 5 ​μm filters. Subsequently, a microscopic analysis of the filter papers was performed. In none of the 800 specimen, a rubber particle was detected by naked eye. Microscopically, 20 (10%) rubber particles were detected in group one, 21 (11%) in group two and 65 (33%) in group three. In group four, no particles were visualized. This study shows the occurrence of rubber particles in 10–33% of the cases, when standard needles are used for the aspiration of drugs. We therefore recommend using industrially prefilled syringes, filter needles or removing the rubber stopper before withdrawing drugs from vials for intra-articular injections.

Background: Slipped capital femoral epiphyses (SCFE) is associated with out-toeing of the foot and external rotation gait. But it is unknown if SCFE patients treated with the modified Dunn procedure have out-toeing at follow up. Therefore, we used instrumented gait analysis and questioned (1) do severe SCFE patients treated with a modified Dunn procedure have symmetrical foot progression angle (FPA) compared with contralateral side and compared with asymptomatic volunteers (2) what is the prevalence of out-toeing gait and what are the outcome socres at follow up. Methods: Gait analysis of 22 patients (22 hips) treated with an unilateral modified Dunn procedure for severe SCFE (slip angle >60 degrees, 2002 to 2011) was retrospectively evaluated. Of 38 patients with minimal 5-year follow up, 2 hips (4%) had avascular necrosis of the femoral head and were excluded for gait analysis. Twenty-two patients were available for gait analysis at follow up (mean follow up of 9±2 y). Mean age at follow up was 22±3 years. Mean preoperative slip angle was 64±8 degrees (33% unstable slips) and decreased postoperatively (slip angle of 8±4 degrees). Gait analysis was performed with computer-based instrumented walkway system (GAITRite) to measure FPA with embedded pressure sensors. Patients were compared with control group of 18 healthy asymptomatic volunteers (36 feet, mean age 29±6 y). Results: (1) Mean FPA of SCFE patients (3.6±6.4 degrees) at follow up was not significantly different compared with their contralateral side (5.6±5.5 degrees) and compared with FPA of controls (4.0±4.5 degrees). (2) Of the 22 SCFE patients, most of them (19 hips, 86%) had normal FPA (−5 to 15 degrees), 2 patients had in-toeing (FPA<−5 degrees) and 1 had out-toeing (FPA >15 degrees) and was not significantly different compared with control group. (3) Mean modified Harris hip score (mHHS) was 93±11 points, mean Hip Disability and Osteoarthritis Outcome Score (HOOS) score was 91±10 points. Three patients (14%) had mHHS 95 points. Conclusions: Patients with severe SCFE treated with modified Dunn procedure had mostly symmetrical FPA and good hip scores at long term follow up. This is in contrast to previous studies. Although 1 patient had out-toeing and 2 patients had in-toeing at follow up, they had good hip scores. Level of Evidence: Level III—retrospective comparative study.