Strong Correlation Between Standing Long-Leg Radiographs and CT Scans in Measuring Coronal Knee Alignment.

BACKGROUND: The objective of this study was to evaluate the correlation in measurements of the lower-limb coronal alignment between long-leg radiographs (LLRs) and computed tomography (CT) scanograms that were made during preoperative planning for robotic-arm-assisted knee arthroplasty. On the basis of published evidence demonstrating a good correlation between these imaging modalities in measuring the lower-limb mechanical axis, we hypothesized that there would be no significant differences between the 2 in the present study. METHODS: This multicenter cohort study across 3 tertiary centers included 300 patients undergoing primary robotic-arm-assisted total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) for whom LLRs and CT scanograms were available preoperatively. The study involved measuring the medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), hip-knee-ankle angle (HKA), joint line obliquity (JLO), joint-line convergence angle (JLCA), and arithmetic HKA (aHKA). The aHKA represents a method for estimating constitutional alignment using angles that are unaffected by joint-space narrowing. RESULTS: Strong correlations (p < 0.001) between the imaging modalities were found for the HKA (correlation coefficient, 0.912), aHKA (0.883), MPTA (0.820), LDFA (0.871), and JLO (0.778). A weaker correlation was observed for the JLCA in valgus knees as compared with varus knees (Spearman coefficients, 0.412 and 0.518, respectively). Regression models demonstrated that the degree of agreement was associated with the preoperative intra-articular deformity and the positioning of the lower limb during the CT scan (i.e., the lower-limb rotational angle). An initial JLCA within ±5° was associated with higher agreement. CONCLUSIONS: We observed a strong correlation between LLRs and CT scanograms that were made during the preoperative planning stage of robotic-arm-assisted knee arthroplasty, implying that CT scanograms can reliably be utilized to estimate the coronal alignment of the knee, potentially replacing the need for LLRs. Nevertheless, to attain a higher degree of agreement, it is crucial to ensure appropriate radiographic positioning of the lower limb. Additionally, surgeons must remain vigilant regarding potential discrepancies in cases involving substantial deformities. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Intra- and interobserver reliability of two classification systems for posterolateral tibial plateau fractures in the setting of an ACL rupture.

Background: Posterolateral tibial plateau impaction fractures occur frequently associated with anterior cruciate ligament (ACL) tears. Some authors advocate operative treatment of high-grade impaction fractures, which has led to the development of classification systems. Our study aims (1) to describe and compare the intra- and interobserver reliability of the two most used classifications and (2) to assess correlations between the grade of bony posterolateral tibial injury, patient characteristics and short-to mid-term revision rate after ACL reconstruction. Materials and methods: In a retrospective series of 163 patients who underwent ACL reconstruction, two reviewers independently evaluated the preoperative MRI scans. Conform the Menzdorf and Bernholt classification the presence and grade of an associated posterolateral impaction fracture were assessed. Statistical analyses were performed to test for both study hypotheses. Results: 171 primary ACL cases were evaluated. Mean follow-up time was 41 months (range 12-154, SD = 17.1). Mean age was 32 years (range 13-59, SD = 12). Posterolateral impaction fractures were present in 111 (64.9 %) and 120 (70.0 %) cases, according to the Menzdorf and Bernholt classification. A Segond fracture was present in 19 (11.1 %) cases. Kappa value was 0.47 for intra- and 0.52 for the interobserver reliability for the Menzdorf classification (moderate reliability). For the Bernholt classification kappa values were 0.66 and 0.61, respectively (good reliability). A Segond fracture correlated significantly with the presence of a posterolateral impaction fracture (p < 0.05). A significant association was present between patients necessitating ACL revision surgery and patients for whom operative intervention for the posterolateral impression was advised following the Menzdorf classification (p < 0.001). Conclusion: Inter- and intraobserver reliability testing for classifying posterolateral tibial fractures resulted in moderate to good reliability. High-grade posterolateral tibial fractures should be identified, selective treatment should be considered as they are associated with higher revision rates after ACL reconstruction if left untreated.

Restoration of the native tibial joint line obliquity in total knee arthroplasty with inverse kinematic alignment does not increase knee adduction moments.

PURPOSE: Patient-specific alignment in total knee arthroplasty (TKA) has shown promising patient-reported outcome measures; however, the clinical and biomechanical effects of restoring the native knee anatomy remain debated. The purpose of this study was to compare the gait pattern between a mechanically aligned TKA cohort (adjusted mechanical alignment-aMA) and a patient-specific alignment TKA cohort (inverse kinematic alignment-iKA). METHODS: At two years postoperatively, the aMA and iKA groups, each with 15 patients, were analyzed in a retrospective case-control study. All patients underwent TKA with robotic assistance (Mako, Stryker) through an identical perioperative protocol. The patients' demographics were identical. The control group comprised 15 healthy participants matched for age and gender. Gait analysis was performed with a 3D motion capture system (VICON). Data collection was conducted by a blinded investigator. The primary outcomes were knee flexion during walking, knee adduction moment during walking and spatiotemporal parameters (STPs). The secondary outcomes were the Oxford Knee Score (OKS) and Forgotten Joint Score (FJS). RESULTS: During walking, the maximum knee flexion did not differ between the iKA group (53.0°) and the control group (55.1°), whereas the aMA group showed lower amplitudes of sagittal motion (47.4°). In addition, the native limb alignment in the iKA group was better restored, and although more in varus, the knee adduction moments in the iKA group were not increased (225 N mm/kg) compared to aMA group (276 N mm/kg). No significant differences in STPs were observed between patients receiving iKA and healthy controls. Six of 7 STPs differed significantly between patients receiving aMA and healthy controls. The OKS was significantly better in patients receiving iKA than aMA: 45.4 vs. 40.9; p = 0.05. The FJS was significantly better in patients receiving iKA than aMA: 84.8 vs. 55.5; p = 0.002. CONCLUSION: At two years postoperatively, the gait pattern showed greater resemblance to that in healthy controls in patients receiving iKA rather than aMA. The restoration of the native coronal limb alignment does not lead to increased knee adduction moments due to the restoration of the native tibial joint line obliquity. LEVEL OF EVIDENCE: Level III.

Evolution of nonoperative treatment of atraumatic sternoclavicular dislocation.

BACKGROUND: Atraumatic sternoclavicular dislocation (ASCD) is an uncommon pathology that is mainly diagnosed in young adults. The aim of this study is to better describe the clinical picture of ASCD and to describe the results of a "wait-and-see" policy in these patients. METHODS: All patients with ASCD who visited our department between 2011 and 2016 were retrospectively analyzed. A standardized clinical examination was used to evaluate the clinical picture. All patients were treated nonoperatively, and at latest follow-up, several parameters and standardized questionnaires (Nottingham Clavicle Score, Oxford Shoulder Score, Constant-Murley Score) were used to evaluate the outcome. RESULTS: In total, 23 patients (12 male, 11 female) were evaluated. The average age at diagnosis was 18.6 years. There was a significant difference (P < .001) in angle of dislocation during forward flexion (mean = 141°) compared with abduction (mean = 101°). At latest follow-up (average 46 months, range 14-113 months; standard deviation [SD] = 27), subluxations still occurred but were less frequent and less prominent relative to presentation at initial diagnosis in 19 of 23 patients. The chance of subjective improvement increased by 27% for each year of follow-up. High outcome scores of Nottingham Clavicle Score (mean score = 80, SD = 11), Oxford Shoulder Score (mean score = 44, SD = 4), and Constant-Murley Score (mean score = 83, SD = 11) were reported. CONCLUSION: In patients with ASCD, the clavicle subluxates earlier in abduction than in forward flexion. After a midterm follow-up, a "wait-and-see" policy does not resolve the subluxations. However, most patients displayed reduced frequency and severity of subluxations over their recovery period and showed excellent scores on shoulder questionnaires.