Implant breakage and revision factors for modular fluted tapered stems in revision total hip arthroplasty.

PURPOSE: Modular stems in revision total hip arthroplasties allow diaphyseal fixation and optimal restoration of the architecture of the proximal femur. Several studies report metaphyseal implant breakage having a negative impact on survivorship. The aim of the study was to evaluate the outcome of an uncemented modular fluted tapered stem (MFT) in revision surgery. METHODS: In a retrospective study, 316 patients who had revision surgery using the same design of MFT implant (Modular Revision Stem [MRS], Lima Corporate, Italy) between 2012 and 2017 were identified. Patients were male in 51% of cases and mean age was 74 years. Indications were 110 periprosthetic fractures, 98 periprosthetic joint infection, 97 aseptic loosening, 10 instability and 1 other cause. Survivorship, complications, clinical and radiographic outcomes, were assessed. Mean follow-up was 5 years. RESULTS: There was no implant breakage. At 5-year follow-up, the survivorship, free from revision for aseptic loosening and free of revision for any reason were 96% and 87%, respectively. At last follow-up (8 years), these figures were 92% and 71%, respectively. 31 implants were revised. The risk of revision for any cause was higher for extreme length metaphyseal implants, hazard ratio was 3.7 (95% CI, 1.82-7.52). A mean stem subsidence of 9 mm was noted in 37 cases; 4 were revised for aseptic loosening. The Harris Hip Score at final follow-up was 82. CONCLUSIONS: At 5-year follow-up, the MFT implant showed a good survivorship and outcomes with no specific complications. Unlike literature reports, no specific complications occurred with this design. Stem junction positioning and therefore metaphyseal length may be key to optimise long-term survivorship. However, a longer follow-up is needed as implant breakage is more often seen after long implantation times.

Dislocation fracture of the femoral head in adult.

The smaller the head fragment, the more likely it is located at the bottom and in front of the femoral head, which then determines the most suitable approach. A CT scan is essential after reduction and before resumption of weight-bearing to verify the size and congruence of the fragments and whether there are foreign bodies and/or a fracture of the posterior wall. Classifications should include the size of the fragment and whether or not there is an associated fracture of the acetabulum or femoral neck (historical 'Pipkin', modernised 'Chiron'). In an emergency, the dislocation should be rectified, without completing the fracture (sciatic nerve palsy should be diagnosed before reduction). A hip prosthesis may be indicated (age or associated cervical fracture). Delayed orthopaedic treatment is sufficient if congruence is good. A displaced fragment can be resected (foreign bodies and » head), reduced and osteosynthesised (⅓ and ½ head), and a posterior wall fracture reduced and osteosynthesised. Small fragments can be resected under arthroscopy. The approach is medial (Luddloff, Ferguson, Chiron) to remove or osteosynthesise ⅓ or » fragments; posterior for ½ head or a fractured posterior wall. The results remain quite good in case of resection or an adequately reduced fragment. Long-term osteoarthritis is common (32%) but well tolerated with a low rate of prosthetisation. Avascular necrosis remains a possible complication (8.2%). Sciatic nerve palsy (4% of fracture dislocations) is more common for dislocations associated with posterior wall fractures.

Comparative study of total hip arthroplasties with dual mobility cups versus hemiarthroplasties in management of femoral neck fractures: Survival and dislocation rate at 5 years of follow-up?

BACKGROUND: Instability after hip arthroplasty, whether it is a total (THA) or intermediate (HA), poses a major risk, however arthroplasty is the standard treatment for displaced intracapsular fractures of the femoral neck of the elderly. Three types of arthroplasties can be proposed: total prostheses with or without a dual mobility cup (DM THA) reducing the risk of dislocation, and hemiarthroplasties. In the absence of clear recommendations regarding the type of implant to be used and the scarcity of studies comparing HA and DM THA, we conducted a monocentric comparative retrospective study using the propensity score method to compare DM THA versus HA on recently displaced femoral neck fractures: (1) survival and risk of dislocation, (2) functional results, (3) mortality. HYPOTHESIS: The rate of dislocation of THA fitted with a DM cup is lower than that of HA. PATIENTS AND METHODS: We retrospectively identified 112 patients in the HA group and 153 patients in the DM THA group who underwent an emergency arthroplasty for a displaced cervical fracture between 2010 and 2013. The minimum follow-up was 5 years (range, 5-9 years). The mean age at surgery was 81 years (range, 55-101 years). Elective surgery patients (n=2), hardware fractures (n=10), pathological fractures of the femoral neck (n=6), associated fractures (n=3), and revision surgeries (n=5) were excluded. The primary outcome measure was instability. Clinical follow-up was performed by the WOMAC score and the risk of mortality was determined after adjusting for confounding factors using the propensity score method. RESULTS: After adjustment by the propensity score, the dislocation rate at 2-years was 2.2% (n=3/153) in the dual mobility THA group and 6.3% (n=7/112) in the HA group (OR=0.34 [95% CI: 0.06-1.96] (p=0.23)). After adjustment by the propensity score, the mean WOMAC score was 8.20 (±6.56) in the THA group, compared to 10.78±3.92 on average in the HA group (p=0.031). After adjustment by the propensity score, we did not find any significant difference in the reoperation rate without changing implants and revisions, and postoperative complications. After adjustment by the propensity score, mortality was significantly higher in the HA group 45.5% (n=69/152) versus 91.5% (n=102/112) in the HA group (OR=0.50 [95% CI: 0.25-0.98] (p=0.042)). DISCUSSION: Few studies have compared these two types of implant in the context of trauma. Although the results of our study are not significant regarding the risk of dislocation, the use of a dual mobility cup seems to be a very satisfactory solution in this trauma context. LEVEL OF EVIDENCE: III; comparative retrospective cohort.

Does augmented core decompression decrease the rate of collapse and improve survival of femoral head avascular necrosis? Case-control study comparing 184 augmented core decompressions to 79 standard core decompressions with a minimum 2 years' follow-up.

INTRODUCTION: Avascular necrosis of the femoral head often progresses to femoral head collapse if not treated. Conservative treatment yields highly variable results and is not standardised, mainly because it is typically evaluated in small patient populations. This led us to conduct a large retrospective comparative study with the goals of 1) analysing survival and functional outcomes, 2) looking for differences in survival between core decompression techniques (standard versus augmented), and 3) studying the risk factors for femoral head collapse and revision by arthroplasty. HYPOTHESIS: Core decompression limits the number of patients who suffer femoral head collapse requiring arthroplasty at 2 years' follow-up. METHODS: This multicentre, comparative, retrospective study analysed 330 patient records (1975-2016) where at least 2 years' follow-up was available. Sixty-two patients were excluded from the analysis: 5 had a stage III with collapse, 5 were lost to follow-up, 2 died within 24 months of the procedure and 50 had incomplete data. The study included 263 patients with a mean age of 42 years (15.7-70). In the Ficat classification, there were 51 cases of stage I necrosis, 186 cases of stage II and 22 cases of stage II with crescent sign (transition stage). The Kerboull angle on radiographs was between 5° and 20° in 40 patients, between 20° and 40° in 107 patients, between 40° and 60° in 52 patients and more than 60° in 29 patients. A standard core decompression was done in 79 patients and an augmented one in 184 patients. The more severe AVN cases (stage II) were more likely to be treated by augmented CD (160/184 patients, 87%) than by standard CD (48/79 patients, 61%) (p<0.001). RESULTS: In the 263 patients, the overall survival (no arthroplasty at 2 years) was 73% (196/263). At 2 years, the survival rate (without arthroplasty) was 71% (56/79) in the standard CD group versus 76% (140/184) in the augmented CD group. This difference was significant when adjusted for Ficat stage and Kerboull angle [HR=0.457, 95% CI (0.247-0.844) (p=0.012)]. When the survival data was adjusted to the Ficat stage, augmented CD was better than standard CD with 10-year survival of 58.1% vs. 57.9% (p=0.0082). More than 30% necrosis volume increased the risk of failure [HR=3.291 95%CI (1.494-7.248) (p=0.0031)]. Also, a Kerboull angle above 60° increased the risk of failure [HR=3.148 95%CI (1.346-7.5) (p=0.0083)]. CONCLUSION: After 2 years, CD for non-collapsed femoral head AVN prevents collapse and revision to arthroplasty in 73% of cases (196/268). Augmented CD improves the 2-year survival and the long-term survival after adjusting for preoperative characteristics (Kerboullangle and Ficat stage). The risk of collapse and need for arthroplasty is greater in patients with 30% necrosis volume on MRI and Kerboull angle above 60°. LEVEL OF EVIDENCE: III; retrospective case-control study.

Periprosthetic joint infection in aseptic total hip arthroplasty revision.

PURPOSE: There is no consensus regarding systematic screening for infection in aseptic revision total hip arthroplasty (THA). The rationale for systematic intra-operative samples is to increase the sensitivity of latent infections detection, which may require specific treatment. However, the incidence of occult infection in revision THAs is not precisely known. As such, the aim of the study was to evaluate the incidence of occult infection in presumed aseptic revision THAs and identify associated risk factors. METHOD: Bacteriological samples from 523 aseptic THA revisions performed for five years were analyzed. Revisions performed for periprosthetic joint infection (PJI) or clinical suspicion of PJI were excluded. Microbiological cultures were performed using tissue samples in 505 cases (97%), synovial fluid in blood culture vials in 158 (30%), and in dry tubes in 263 (50%). Implants were sent for sonication in 12 cases (2.6%). The mean number of microbiological samples per patient was 3.6 (range, 1-15). Histology samples were collected for 300 patients (57%). RESULTS: The incidence of occult infection was 7% (36 cases) and contamination 8% (42 cases). Among occult infections, the primary reasons for revision were dislocation (42%), aseptic loosening (25%), fracture (19%), and others (14%). The infection rate in the dislocation group was significantly higher than that of other reasons for revision (p < 0.001). Among the patients determined with PJI, the revision THA was performed less than a year after primary in 19 (53%). CONCLUSION: The incidence of occult PJI justifies systematic intraoperative sampling. A short time between primary arthroplasty and revision or an early postoperative dislocation is a factor to suspect infections.

The Delta of Correction: a novel, more reliable variable than limb-length discrepancy at predicting outcome after total hip arthroplasty.

BACKGROUND: Leg-length discrepancy (LLD) is a frequent and recurring issue after total hip arthroplasty (THA). It can lead to discomfort and litigation due to the patient's perception of this inequality. PURPOSE: The aim of this study was to evaluate the functional impact of postoperative LLD and length correction in patients after primary THA. We hypothesised that clinical outcomes are inversely correlated to length correction and residual discrepancy. METHODS: In a prospective cohort, we included 121 patients undergoing unilateral primary THA. Patients were categorised into 3 groups based on their residual LLD using routine EOS imaging; Shorter (<-5 mm); Equal (-5 mm to +5 mm); and Longer (>+5 mm). Delta of Correction (DC) was defined as the difference between pre- and postoperative discrepancy measured on EOS imaging. Functional scores (HHS, Postel Merle d'Aubigné, and WOMAC) were measured preoperatively and at last follow-up. The average follow-up was 24 months. We evaluated the clinical and radiographic outcomes regarding the residual LLD and DC. RESULTS: All patients had improvement in their functional scores at last follow-up. There was no difference in clinical outcomes, regardless of preoperative or residual LLD. The highest scores were found in the population with the smallest variations (DC -5 to +5 mm, HHS 96). Conversely, poorer results were found in shortened patients (DC <-5 mm), HHS 86, and lengthened patients, corrected by > 15 mm, with HHS of 83, p < 0.005. Patient perception of postoperative LLD correlated with the DC (p = 0.004). CONCLUSION: The DC measurement is a more effective assessment than arthroplasty.

Patient Participation During Anterior Cruciate Ligament Reconstruction Improves Comprehension, Satisfaction, and Functional Outcomes: A Simple Way to Improve Our Practices.

BACKGROUND: It is estimated that 28% of patients are dissatisfied after anterior cruciate ligament (ACL) reconstruction, in part because they do not understand the procedure well enough. PURPOSE: To assess the postoperative comprehension, satisfaction, and functional outcomes of 2 patient groups: 1 undergoing a standard surgical procedure (standard group) and 1 involved in their surgery (participation group). STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Over a 4-month period, 62 patients were included: 31 in the standard group and 31 in the participation group. The preoperative information, surgical technique, anesthesia, and postoperative course were identical in both groups. Patients in the participation group were allowed to watch the arthroscopic portion of their surgery live on a video screen, and standardized information was given to these patients during the arthroscopic phase. Self-administered questionnaires were given to assess comprehension (Matava score), satisfaction (visual analog scale [VAS] for satisfaction, Net Promoter Score [NPS], and Evaluation du Vécu de l'Anesthésie LocoRégionale [EVAN-LR]), and outcomes (International Knee Documentation Committee [IKDC] form and Anterior Cruciate Ligament-Return to Sport after Injury [ACL-RSI] scale) between groups. RESULTS: Postoperative comprehension was significantly improved in the participation group, as the Matava score increased by a mean of 7.1 ± 5.3 points versus 2.7 ± 5.6 points in the standard group (P = .0024). The mean VAS satisfaction score immediately after surgery was 9.8 ± 0.6 in the participation group versus 8.9 ± 1.9 in the standard group (P = .0033); this difference was still present at 1 year postoperatively (9.8 ± 0.6 vs 9.1 ± 1.7, respectively; P = .0145). The NPS was 96.8% in the participation group versus 64.5% in the standard group (P = .0057) in the immediate postoperative period and 100.0% in the participation group versus 71.0% in the standard group at 1 year postoperatively (P = .0046). The mean total EVAN-LR score was 89.1 ± 6.5 in the participation group and 84.6 ± 9.9 in the standard group (P = .0416). At 1 year postoperatively, the mean IKDC score was 86.0 ± 7.5 in the participation group versus 80.0 ± 7.4 in the standard group (P = .0023). The mean ACL-RSI score was 80.9 ± 7.7 in the participation group versus 74.3 ± 8.4 in the standard group (P = .0019). CONCLUSION: Involving patients in their ACL reconstruction surgery improves their understanding of the procedure and their satisfaction with their care, which results in better outcomes at 1 year postoperatively.

Determination of normal KOOS and WOMAC values in a healthy population.

PURPOSE: The KOOS questionnaire is used to assess the symptoms and function of patients with traumatic or degenerative knee pathology. The WOMAC score has been validated mainly in the context of knee osteoarthritis. The distribution of these scores in a non-diseased population is not known. The hypothesis was that KOOS and WOMAC scores were influenced by patients' age, sex, and BMI. The primary objective of this study was to describe, for the first time, the distribution of KOOS and WOMAC scores in a healthy population based on age, sex, and BMI. METHODS: This was a pilot (innovative), cross-sectional, international, multicenter, descriptive study. Persons accompanying patients to our clinic were invited to participate in this study by filling out the KOOS questionnaire. These data were also used to calculate the WOMAC score. The study was designed according to guidelines on pilot studies and planned to enroll a minimum of 30 subjects in each age, gender, and BMI group. Expected KOOS and WOMAC scores by age, gender, and BMI were determined using a linear regression model. RESULTS: Seven hundred and fourteen subjects were included: 305 men (42.7%) and 409 women (57.3%). For the KOOS score, as age increases, there was a decrease in the "ADL" (p = 0.0001) and "sport" (p = 0.0001) items and an increase in the "symptoms" (p = 0.0025) and "QOL" items (p = 0.0001). Women had lower scores (p < 0.05) than men on all the KOOS items, except "QOL". For the WOMAC, the "pain", "stiffness", and "function" items varied significantly based on age (p = 0.0203) and sex (p = 0.0121). The "stiffness" item varied significantly based on age (p = 0.0005) and sex (p = 0.0477). The "function" item varied significantly based on age (p = 0.0001) and sex (p = 0.0256). The expected value for the KOOS and WOMAC scores in a healthy population without any knee ailments were determined. CONCLUSIONS: The KOOS and WOMAC scores vary significantly based on age, sex, and BMI in a healthy population. This study also provides KOOS and WOMAC values in a population without any knee issue. These scores can be used, in a daily practice, as a reference to assess functional outcomes after a surgical procedure. LEVEL OF EVIDENCE: IV.

Distal femoral torsion: Differences between caucasians and asians. A multicentre computed tomography study of 515 distal femurs.

BACKGROUND: The posterior condylar angle (PCA) is formed by the posterior condylar line (PCL) and the clinical (or anatomic) transepicondylar line (TEL). The primary objective of this study was to compare the distribution of PCA values in Caucasians and Asians free of knee osteoarthritis. The secondary objectives were to assess PCA variability according to age, gender, and side. HYPOTHESIS: PCA values differ between Caucasians and Asians. METHODS: The study included the computed tomography scans of 515 healthy femurs, 259 from Asians in China and 256 from Caucasians in France. PCA values were determined based on four landmarks, namely, the two femoral epicondyles and the most prominent point of each condyle at the posterior aspect of the knee. The Mann-Whitney test was chosen to compare PCA values according to ethnic group, gender, and side and Spearman's correlation coefficient to assess correlations with age. Inter-observer and intra-observer variability of PCA measurements was assessed. RESULTS: Mean PCA was 6.0°±2.5° (range, 0°-14°) overall, 6.4° (range, 0.31°-14.1°) in the Asians, and 5.5° (range, 0°-13.1°) in the Caucasians (p<0.0001). Chinese femurs are significantly more internally rotated. No differences in PCA values were found according to age (p=0.4307), gender (p=0.7113), or side (p=0.4304). Inter-observer and intra-observer variability was limited for each of the landmarks, indicating that PCA measurement was reliable. CONCLUSION: PCA varies not only across individuals as reported previously, but also across ethnic groups. This finding further supports routine PCA measurement on imaging studies before total knee arthroplasty. LEVEL OF EVIDENCE: III, comparative retrospective study.

Editorial Commentary: Knee Anterolateral Ligament Bashing-Why So Much Negativity?

Articles on the anterolateral ligament have generated lots of discussion, but a worldwide consensus has been recently reached: the anterolateral ligament exists. Cadaver studies on a small number of subjects should not be used to draw conclusions as they do not replicate real life. We place our faith in clinical studies with a large number of patients as they capture the variability encountered in our practices. This is the true test of a scientific concept.

Evaluation of reproducibility of robotic knee testing device (GNRB) on 60 healthy knees.

INTRODUCTION: There is a main concern about the usefulness and the accuracy of the different laximeters. The GnrB device is becoming more popular, but according to the literature it's not clear whether it is fully reliable. OBJECTIVE: GNRB laxity measurements are not reproducible for measurement of anterior translation of the tibia. MATERIAL AND METHODS: We analyzed the reproducibility of GNRB measurements in healthy subjects by the Test-Retest method in 2 sessions. RESULTS: 30 pairs of healthy knees were assessed. Test-Retest agreement was poor for both absolute values and for differentials at 134 and 200 N with an intra-class correlation ranging from 0.210 to 0.486. There was a significant differance in anterior tibial translation, in side-to-side difference, according to the patellar pressure. CONCLUSION: The reproducibility is found to be poor under optimum conditions of comparability. The patellar pressure influences strongly thelaxity value.

How to Test the Anterolateral Ligament With Ultrasound.

Ultrasonography (US) is a nonirradiating, low-cost, real-time imaging modality that has very good spatial resolution. US can be used to view the anterolateral ligament (ALL) and injuries to the ALL. Several authors have sought to analyze the anterolateral aspect of the knee using US with varying luck. All of them analyzed the ALL statically only. The goal of this Technical Note is to describe in detail the technique that we use to analyze the anterolateral aspect of the knee in patients with an anterior cruciate ligament tear. We use a simple technique that starts by locating the tibial end of the ALL. The lateral inferior genicular artery is a reliable landmark in this context. The analysis is dynamic in addition to being static. To determine if the ALL is injured, we look for a lack of tension on the ALL when the knee is internally rotated and for a Segond fracture. We believe that it is essential to start evaluating the ALL by its tibial end. US analysis of the ALL forms the basis for developing an appropriate "à la carte" treatment for the patient's injury.

Hamstring Graft Incorporation According to the Length of the Graft Inside Tunnels.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction with a quadrupled semitendinosus (ST4) graft is an evolution of the standard technique with 2 hamstring tendons (semitendinosus + gracilis [STG]). However, there is no published comparison of how well these 2 types of hamstring grafts are incorporated into the bone tunnels. Because the ST4 graft is shorter, there is less graft material inside the tunnels. PURPOSE: To use magnetic resonance imaging (MRI) to compare graft incorporation in the tibial bone tunnels 1 year after ACL reconstruction with either an STG graft or ST4 graft. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Sixty-two patients who underwent ACL reconstruction were enrolled prospectively: 31 with an ST4 graft and 31 with an STG graft. The same surgical technique, fixation method, and postoperative protocol were used in both groups. Graft incorporation and ligamentization were evaluated with MRI after 1 year of follow-up. The following parameters were evaluated: signal-to-noise quotient (SNQ), tibial tunnel enlargement, signal intensity at the bone-graft interface, and graft signal according to the Howell scale. The number of participants needed to show that the mean SNQ did not differ between the 2 techniques was 31 in each group (with a 1-sided alpha of 2.5% and a 1-sided beta of 10.0%). The Student t test was used to compare the distribution of continuous secondary endpoints. RESULTS: The mean SNQ was 5.2 ± 4.5 for the STG group and 5.9 ± 3.7 for the ST4 group ( P = .5100). The mean tibial tunnel widening was 93.7% ± 51.7% for the STG group versus 80.0% ± 42.9% for the ST4 group ( P = .2605). The groups did not differ in signal intensity at the bone-graft interface ( P = .7502) or in graft signal according to the Howell scale ( P = .4544). CONCLUSION: At the 1-year postoperative follow-up, incorporation and ligamentization of the STG and ST4 grafts were the same based on MRI analysis. The results were at least as good with the ST4 technique as with the standard STG technique in terms of incorporation and ligamentization.

Geometric morphometric analysis reveals age-related differences in the distal femur of Europeans.

BACKGROUND: Few studies have looked into age-related variations in femur shape. We hypothesized that three-dimensional (3D) geometric morphometric analysis of the distal femur would reveal age-related differences. The purpose of this study was to show that differences in distal femur shape related to age could be identified, visualized, and quantified using three-dimensional (3D) geometric morphometric analysis. METHODS: Geometric morphometric analysis was carried out on CT scans of the distal femur of 256 subjects living in the south of France. Ten landmarks were defined on 3D reconstructions of the distal femur. Both traditional metric and geometric morphometric analyses were carried out on these bone reconstructions. These analyses were used to identify trends in bone shape in various age-based subgroups (<40, 40-60, >60). RESULTS: Only the average bone shape of the < 40-year subgroup was statistically different from that of the other two groups. When the population was divided into two subgroups using 40 years of age as a threshold, the subject's age was correctly assigned 80% of the time. DISCUSSION: Age-related differences are present in this bone segment. This reliable, accurate method could be used for virtual autopsy and to perform diachronic and interethnic comparisons. Moreover, this study provides updated morphometric data for a modern population in the south of France. CONCLUSION: Manufacturers of knee replacement implants will have to adapt their prosthesis models as the population evolves over time.

Three-dimensional geometric morphometric analysis reveals ethnic dimorphism in the shape of the femur.

BACKGROUND: Ethnic dimorphism in the distal femur has never been studied in a three-dimensional analysis focused on shape instead of size. Yet, this dimorphism has direct implications in orthopedic surgery and in anthropology. The goal of this study was to show that differences in distal femur shape related to ethnic dimorphism could be identified, visualized, and quantified using 3D geometric morphometric analysis. METHODS: CT scans of the distal femur were taken from 482 patients who were free of any bone-related pathology: 240 patients were European (E) and 242 were Asian (A). Ten osteometric landmarks based on standard bone landmarks used in anthropometry were placed on these scans. Geometric morphometric analysis, principal component analysis (PCA), canonical variates analysis (CVA), and other discriminant analyses (Goodall's F-test and Mahalanobis distance) were performed. A cross-validation analysis was carried out to determine the percentage of cases in which the ethnicity was correctly estimated. RESULTS: The shape of the E and A distal femur differed significantly (Goodall's F = 94.43, P < 0.001 and Mahalanobis D2 distance = 1.85, P < 0.001). PCA identified a difference in distal femur shape between A and E. The CVA revealed that correct ethnicity was assigned in 82% of cases and the cross-validation revealed a 75% rate of correct ethnic group estimation. CONCLUSION: The distal femur exhibits ethnic dimorphism. 3D geometric morphometric analysis made it possible to demonstrate these differences. The large number of subjects studied has helped modernize the references for certain bone measurements, with direct implication for orthopedic surgery and anthropology.

Ultrasonographic Evaluation of Anterolateral Ligament Injuries: Correlation With Magnetic Resonance Imaging and Pivot-Shift Testing.

PURPOSE: (1) To compare the diagnostic ability of ultrasonography (US) and magnetic resonance imaging (MRI) to detect anterolateral ligament (ALL) injuries in anterior cruciate ligament (ACL)-deficient patients, and (2) to evaluate the correlation between ALL injury status (as determined by US and MRI) and the knee's rotational stability. METHODS: Thirty patients with an isolated ACL injury were included prospectively over a 3-month period. The condition of the ALL was evaluated by 2 experienced radiologists using both US and MRI. Rotational stability was evaluated by 2 surgeons with the pivot-shift test with patients under general anesthesia. It was classified as either negative (grades 0 and I) or positive (grades II and III). The radiologists were blinded to the knee's rotational stability, and the surgeons were blinded to the ALL's status based on the US images. The correlation between the ALL's injury status (US and MRI) and the pivot shift was determined with the Pearson χ2 test. To evaluate the reproducibility of the results, the agreement between observers was determined with the Cohen κ coefficient. RESULTS: On US, the ALL was identified and visible over its entire length in 100% of patients (30 of 30, κ = 1). The ALL was injured in 63% of patients (19 of 30, κ = 0.93). On MRI, the ALL was identified in 96% of patients (29 of 30, κ = 0.91). The ALL appeared injured in 53% of cases (16 of 30, κ = 0.93). An ALL that appeared injured on US was more often associated with a positive pivot shift than was an uninjured ALL (75% vs 39%, χ2 = 13.7, P < .05). The interobserver agreement was high for both US (κ = 0.91-1) and MRI (κ = 0.76-1). CONCLUSIONS: US is a reproducible examination for the diagnosis of ALL injury. An ALL injury is most often associated with a high pivot-shift grade. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Historical perspective on the "discovery" of the anterolateral ligament of the knee.

There is a lively debate about the existence, origins and discoverer of the anterolateral ligament of the knee. The complex anatomy of the lateral aspect of the knee has made it difficult to differentiate between various structures such as the iliotibial band, capsulo-osseous layer, Kaplan's fibres and the anterolateral capsule. The "discovery" of a new anterolateral structure in 2013 was the culmination of many historical studies. In 1879, Paul Ferdinand Segond described a tibial plateau fracture in which he noted a pearly band reinforcing the joint capsule. Other anatomists had their suspicions about this ligament; it was described by Vallois in 1914 in his thesis and extensively studied by Jost in 1921. References to it can be found in comparative anatomy studies. This historical review serves as a reminder that understanding and treating knee sprains is not something new. LEVEL OF EVIDENCE: V.

Cadaveric Study Comparing the Biomechanical Properties of Grafts Used for Knee Anterolateral Ligament Reconstruction.

PURPOSE: To measure the biomechanical properties (maximum load, stiffness, and elongation) of the anterolateral ligament (ALL), gracilis, and iliotibial band (ITB) within the same subject. METHODS: Thirteen unpaired knees were used (7 women, 6 men). The donors had a mean age at death of 54 years (range: 37 to 70 years). The mechanical properties of two types of ALL grafts were evaluated: ITB and two-strand gracilis. The mechanical properties of ALL were also measured. Validated methods were used to perform the tensile tests to failure and to record the results. Student's t-test was used to compare the various samples. RESULTS: The maximum load to failure was 141 N (±40.6) for the ALL, 200.7 N (±48.7) for the gracilis, and 161.1 N (±27.1) for the ITB. Only the gracilis had a significantly higher failure load than ITB and ALL (P = .001 and P = .03). The stiffness was 21 N mm-1 (±8.2) for the ALL, 131.7 N mm-1 (±43.7) for the gracilis, and 39.9 N mm-1 (±6) for the ITB. The elongation at failure was 6.2 mm (±3.2) for the ALL, 19.9 mm (±6.5) for the gracilis, and 20.8 mm (±14.7) for the ITB. CONCLUSIONS: The gracilis had the highest maximum load to failure. The ITB's mechanical properties most closely resemble those of the ALL. CLINICAL RELEVANCE: The biomechanical properties of each potential ALL graft can be factored in when deciding which type of graft to use.

Geometric morphometric analysis reveals sexual dimorphism in the distal femur.

An individual's sex can be determined by the shape of their distal femur. The goal of this study was to show that differences in distal femur shape related to sexual dimorphism could be identified, visualized, and quantified using 3D geometric morphometric analysis. Geometric morphometric analysis was carried out on CT scans of the distal femur of 256 subjects living in the south of France. Ten landmarks were defined on 3D reconstructions of the distal femur. Both traditional metric and geometric morphometric analyses were carried out on these bone reconstructions; these analyses identified trends in bone shape in sex-based subgroups. Sex-related differences in shape were statistically significant. The subject's sex was correctly assigned in 77.3% of cases using geometric morphometric analysis. This study has shown that geometric morphometric analysis of the distal femur is feasible and has revealed sexual dimorphism differences in this bone segment. This reliable, accurate method could be used for virtual autopsy and be used to perform diachronic and interethnic comparisons. Moreover, this study provides updated morphometric data for a modern population in the south of France.