Does plate position influence the outcome in midshaft clavicular fractures? A multicenter analysis

PURPOSE To date, it remains unclear whether superior or anterior plating is the best option for treating midshaft clavicular fractures. The aim of this study was to compare both techniques with regard to the incidence of implant removal due to implant irritation, risk of complications, time to union, and function. METHODS In this retrospective cohort study, all midshaft clavicular fractures treated operatively between 2017 and 2020 in two hospitals in Switzerland were analyzed. The participating hospitals differed with regard to their standard practice; one offered superior plating only, while the other predominantly employed an anterior plate. The primary outcome was the incidence of implant removal for irritation. Secondary outcomes were time to union, complications, re-interventions, and range of motion during the follow-up period of at least 6 months. RESULTS In total, 168 patients were included in the study of which 81 (48%) received anterior plating and 87 (52%) superior plating. The overall mean age was 45 years (SD 16). There was no significant difference between anterior and superior plating with regard to implant removal (58.5% versus 57.1%, p = 0.887), infection (5.7% versus 1.8%, p = 0.071), and time to union (median 48 weeks versus 52 weeks, p = 0.643). Data on range of motion were available in 71 patients. There was no significant difference in anteflexion (median 180 degrees anterior versus 180 degrees superior) and abduction (median 180 degrees anterior versus 180 degrees superior) between the two groups. CONCLUSION This retrospective cohort study did not find sufficient evidence to recommend one implant position over the other for midshaft clavicular fractures with regard to removal due to irritation. Time to union was similar and Infections were equally rare in both groups. Notably, a considerable number of patients in both groups had their implants removed due to irritation. Larger prospective studies are needed to determine how much plate position contributes to the occurrence of irritation and whether other patient or implant-related factors might play a role. Until this is clarified, implant position should be based on surgeons preference and experience

Total knee arthroplasty: posterior tibial slope influences the size but not the rotational alignment of the tibial component

The reasons leading to rotational tibial malalignment in total knee arthroplasties (TKAs) remain unclear. A previous cadaver study has shown an increase in internal rotation of the anatomical tibial axis (ATA) after the tibial cut. This study investigates the influence of tibial slope on the ATA and the size of the resected tibial surface.; CT scans of 20 cadaver knees were orientated in a standardized coordinate system and used to determine the position of the centres of rotation of the medial and lateral tibial articular surfaces and, hence, of the ATA, after a virtual resection of 6 mm with 0°, 3.5°, 7° and 10° slope, respectively. Furthermore, at each slope, the radii of the medial and lateral tibial articular surfaces after resection were calculated.; Compared to resection of 6 mm with 0° slope, a slope of 3.5° resulted in a mean external rotation of the ATA of 0.9° (SD, 1.5°; P = 0.025). A slope of 7° resulted in a mean external rotation of the ATA of 1.0° (SD 2.0°; P = 0.030) and a slope of 10° had no influence on the rotation of the ATA. The radii of the medial and lateral articular surfaces of the cut tibiae were larger than those of the uncut tibia (P < 0.001).; Differences in the posterior tibial slope should not contribute to a rotational malalignment when using the ATA to align the prosthetic tibial plateau. Although statistically significant, the change in ATA with increasing slope was negligible

Using the anatomical tibial axis for total knee arthroplasty alignment may lead to an internal rotation error

Introduction: Despite intensive research, current total knee arthroplasty (TKA) designs do not always provide the correct kinematics for the native joint and thus further optimisation is necessary. Several studies support the importance of malrotation of the tibial components in the failure of TKA. We hypothesise that using the anatomical tibial axis (ATA) to align tibial component rotation on the resected tibial surface may lead to an internal rotation error due to relative anterior shift of the lateral articular surface centre compared to the medial one. The aim of this study was to compare the anatomical tibial axis of the physiological tibial joint surface to the resected one. Method: Twenty formalin-fixed cadaveric knees were obtained for study. After computed tomography scanning the data of each specimen were entered into a standardised coordinate system and virtual bone cuts were performed with 6, 8 and 10mm resection depths. The positions of the articular surface centres were determined at each resection depth. Results: The lateral articular surface centre had moved anteriorly after the resection by a mean 1.475mm, while the medial one had not changed significantly. Resecting the tibia at a 6-mm cut and using the transverse tibial axis to align the prosthetic tibial plateau will result in a mean 4.0° (95% confidence interval, 2.5-5.5°) of internal rotation compared to the uncut tibia. Discussion: The ATA lies in 6 degrees of external rotation compared to the perpendicular to the posterior tibial condylar axis (PTCA). Graw et al. suggest aligning the tibial component in 10 degrees of external rotation to the latter. Thus, if we accept the above suggestion, the ATA is 4 degrees internally rotated compared to the same line on the resected proximal tibia. These prior studies appear to be in accordance with our findings. Conclusions: We conclude that using the ATA on the resected tibial surface may contribute to an internal rotation error

Using the anatomical tibial axis for total knee arthroplasty alignment may lead to an internal rotation error

INTRODUCTION: Despite intensive research, current total knee arthroplasty (TKA) designs do not always provide the correct kinematics for the native joint and thus further optimisation is necessary. Several studies support the importance of malrotation of the tibial components in the failure of TKA. We hypothesise that using the anatomical tibial axis (ATA) to align tibial component rotation on the resected tibial surface may lead to an internal rotation error due to relative anterior shift of the lateral articular surface centre compared to the medial one. The aim of this study was to compare the anatomical tibial axis of the physiological tibial joint surface to the resected one. METHOD: Twenty formalin-fixed cadaveric knees were obtained for study. After computed tomography scanning the data of each specimen were entered into a standardised coordinate system and virtual bone cuts were performed with 6, 8 and 10 mm resection depths. The positions of the articular surface centres were determined at each resection depth. RESULTS: The lateral articular surface centre had moved anteriorly after the resection by a mean 1.475 mm, while the medial one had not changed significantly. Resecting the tibia at a 6-mm cut and using the transverse tibial axis to align the prosthetic tibial plateau will result in a mean 4.0 degrees (95 % confidence interval, 2.5-5.5 degrees ) of internal rotation compared to the uncut tibia. DISCUSSION: The ATA lies in 6 degrees of external rotation compared to the perpendicular to the posterior tibial condylar axis (PTCA). Graw et al. suggest aligning the tibial component in 10 degrees of external rotation to the latter. Thus, if we accept the above suggestion, the ATA is 4 degrees internally rotated compared to the same line on the resected proximal tibia. These prior studies appear to be in accordance with our findings. CONCLUSIONS: We conclude that using the ATA on the resected tibial surface may contribute to an internal rotation error