Dynamic Locking Plate versus Multiple Cancellous Screws for the Fixation of Intracapsular Femoral Neck Fractures: Long-Term Results and Quality-Of-Life Assessment Based on Patient-Reported Outcome Measures.

The purpose of this study was to compare the long-term clinical outcomes and quality-of-life measures for two fixation methods in the setting of displaced femoral neck fractures. The two groups included fixation with multiple cancellous screws (group 1) and telescopic femoral neck screws and a small locking plate device (Targon FN) (group 2). Patients underwent reduction and internal fixation with either multiple cancellous screws or the Targon FN device from March 2000 to January 2012. Failure endpoints included nonunion, osteonecrosis of the femoral head, and revision surgery. Patient-reported outcome measures included chronic pain, ability to ambulate, and the use of ambulation assistive devices. Statistical analysis demonstrated a statistically significant lower rate of non-union and overall complication in the Targon FN group (p value < 0.001 and p value = 0.005, respectively). Logistic regression analysis showed that operative fixation with the Targon FN device decreased the odds ratio for overall complication by a factor of 0.34 (p = 0.02). There were no statistically significant differences between groups 1 and 2 in patient-reported outcomes (chronic pain (p = 0.21), ability to ambulate (p = 0.07), and the use of an ambulation assistive device (p = 0.07)). When compared to traditional cancellous screw fixation of femoral neck fractures, the Targon FN device has significantly lower complication rates and equivalent patient-reported outcomes.

Is There an Association between BMI, Height, and Gender and Long-Bone Fractures during Childhood and Adolescence? A Large Cross-Sectional Population Study of 911,206 Subjects.

INTRODUCTION: Traumatic long-bone fractures (TLFs) among children and adolescents are relatively common, with morbidity and economic consequences. Obesity has become a significant global concern. Studies have found an association between TLFs and BMI in the past but not in a large cross-sectional population study. Our study objective was to measure the incidence of TLFs in the 17-year-old general population and evaluate its association with BMI, body height, and gender. METHODS: Data from a medical database containing all 17-year-old candidates' records before recruitment into mandatory military service were retrieved as BMI, height, gender, and history of TLFs. Logistic regression models assessed the association between BMI and height to TLFs. RESULTS: The records of 911,206 subjects (515,339 males) were reviewed. In total, 9.65% had a history of TLFs (12.25% and 6.25% for males/females, respectively). Higher BMI was associated with TLF, with a linear trend in the odds ratio (OR) for having TLFs. The strongest association was found between obese females and TLFs (OR = 1.364, p < 0.0001). Height was an independent factor positively associated with TLFs. The OR for a TLF in the highest height quintile was 1.238 (p < 0.001) for males and 1.411 (p < 0.001) for females compared to the lowest quintile. Although TLFs were more common in males, the OR for TLFs was more prominent in females. CONCLUSIONS: There is an association between BMI, body height, and TLFs in healthy adolescents. TLFs are more common in males, but the strongest association between overweight and obesity is evident in females.

CT and MRI as Diagnostic and Management Decision Tools for First Time Lateral Patellar Dislocations: A Cross-Sectional, Retrospective Study.

Background: Following first-time lateral patellar dislocation (FTLPD), most patients are treated conservatively, although 50% of patients will have recurrent dislocations. Typically, radiographs followed by CT and/or MRI are used to assist the clinician in determining treatment strategy and, combined with clinical findings, intraarticular free bodies (CT/MRI), significant medial patellofemoral ligament (MPFL) tear (MRI) and lateral displacement of the patella (CT) form relative indications for surgery. Methods: Radiographs, MRI and CT knee studies of 34 patients after lateral patellar dislocation (26 FTLPD) were evaluated for intraarticular free bodies, patellar/trochlear fracture, lateral femoral condyle compression, MPFL tear, tibial tuberosity-trochlear groove (TT-TG) distance, and surgery indications. Free bodies and fractures were also evaluated on knee radiographs. FTLPD was analyzed as a subgroup. Surgical indications were compared between imaging modalities. Results: Among FTLPD (26 patients); free bodies were identified in 13 and 19 patients using MRI and CT respectively, compared with 5 patients on radiographs; this was statistically significant. In 8 cases surgery was indicated based on MPFL tear (MRI) combined with lateral patellar displacement (CT). When MRI and CT results were combined, 21 of 26 patients had imaging indications for surgery compared to 13 and 19 patients based on the MRI or CT alone, respectively.CT was statistically better than MRI alone or MRI with radiographs in identifying patients requiring surgery. Conclusion: An MRI or CT study is warranted to determine the need for surgery. A second imaging study (different from the first) should be considered, if surgical indication was not established from the initial study or clinical presentation.

Early Postoperative Complications and Ambulation in Patients Treated for Hip Fractures, the Unexpected Positive Influence of the COVID-19 Pandemic: A Comparison Study.

BACKGROUND: The influence of the coronavirus disease 2019 (COVID-19) pandemic caused countries worldwide to implement lockdowns. Elective surgeries were temporarily suspended, with surgeries being performed only for emergent/urgent medical conditions such as hip fractures where early surgical intervention has shown decreased rates of morbidity/mortality. OBJECTIVES: To assess the indirect influence of the COVID-19 pandemic and associated lockdown on hip fracture patients, considering factors such as time to surgery, early postoperative complications, and ambulation status. METHODS: A comparative retrospective study was conducted on consecutive patients presenting to our emergency department (ED) with hip fractures that were treated surgically (N=29) during a 1-month period during the government lockdown due to the COVID-19 pandemic. The treatments were compared to consecutive patients who presented with hip fractures and were treated surgically (N=44) during the same timeframe in the previous year (control). Comparisons were made using t-test, ANOVA test, Fisher's exact test, and chi-square test. RESULTS: The COVID-19 group was operated on sooner (20.34 vs. 34.87 hours), had fewer early postoperative complications (10.3% vs. 31.8%), had better ambulatory status at discharge, and experienced a shorter hospital stay (5.93 vs. 8.13 days) with more patients being discharged home (72.4% vs. 22.7%). CONCLUSIONS: Patients presenting with hip fractures to our ED during the COVID-19 pandemic lockdown indirectly benefited from this situation by undergoing earlier surgical treatment, thus experiencing fewer early postoperative complications, faster ambulation, and sooner discharge.

Anterior cruciate ligament graft forces are sensitive to fixation angle and tunnel position within the native femoral footprint during passive flexion.

BACKGROUND: Anterior cruciate ligament (ACL) graft position within the anatomic femoral footprint of the native ACL and the flexion angle at which the graft is fixed (i.e., fixation angle) are important considerations in ACL reconstruction surgery. However, their combined effect on ACL graft force remains less well understood. HYPOTHESIS: During passive flexion, grafts placed high within the femoral footprint carry lower forces than grafts placed low within the femoral footprint (i.e., high and low grafts, respectively). Forces carried by high grafts are independent of fixation angle. All reconstructions impart higher forces on the graft than those carried by the native ACL. STUDY DESIGN: Controlled laboratory study. METHODS: Five fresh-frozen cadaveric knees were mounted to a robotic manipulator and flexed from full extension to 90° of flexion. The ACL was sectioned and ACL force was calculated via superposition. ACL reconstructions were then performed using a patellar tendon autograft. For each knee, four different reconstruction permutations were tested: high and low femoral graft positions fixed at 15° and at 30° of flexion. Graft forces were calculated from full extension to 90° of flexion for each combination of femoral graft position and fixation angle again via superposition. Native ACL and ACL graft forces were compared through early flexion (by averaging tissue force from 0 to 30° of flexion) and in 5° increments from full extension to 90° of flexion. RESULTS: When fixed at 30° of flexion, high grafts carried less force than low grafts through early flexion bearing a respective 64 ± 19 N and 88 ± 11 N (p = 0.02). Increasing fixation angle from 15° to 30° caused graft forces through early flexion to increase 40 ± 13 N in low grafts and 23 ± 6 N in high grafts (p < 0.001). Low grafts fixed at 30° of flexion differed most from the native ACL, carrying 67 ± 9 N more force through early flexion (p < 0.001). CONCLUSION: ACL grafts placed high within the femoral footprint and fixed at a lower flexion angle carried less force through passive flexion compared to grafts placed lower within the femoral footprint and fixed at a higher flexion angle. At the prescribed pretensions, all grafts carried higher forces than the native ACL through passive flexion. CLINICAL RELEVANCE: Both fixation angle and femoral graft location within the anatomic ACL footprint influence graft forces and, therefore, should be considered when performing ACL reconstruction.

ASSESSMENT OF HUMERAL TORSION BY PALPATION IN BASEBALL PITCHERS: A VALIDATION STUDY.

BACKGROUND/PURPOSE: Greater humeral retroversion has been associated with shoulder and elbow injuries. Methods for measuring torsion include radiography, computed tomography (CT) and sonography (US) which may be costly or unavailable. A palpation method might be a reliable alternative to imaging techniques. The purpose of the current study was to examine the construct validity of the palpation technique for humeral torsion by (1) determining if a side-to-side difference in humeral torsion (HT) could be detected in a cohort of baseball pitchers using the palpation technique and (2) compare the side-to-side difference in HT obtained through the palpation method to the US method. HYPOTHESIS: Clinical assessment of HT by palpation is reliable and is as accurate as sonographic HT measurements among overhead athletes. METHODS: Twenty collegiate and high school pitchers were assessed. Bilateral shoulder passive external rotation (ER) and internal rotation (IR) range of motion were measured. Humeral torsion was indirectly measured using sonographic and palpatory methods. Paired t-tests were used to determine HT side-to-side difference measured by US versus palpation. Pearson's correlation coefficient (r) was used to determine the relationship between HT side-to-side difference detected by palpation and US, and relationships among IR and ER of the shoulder and HT side to-side difference measurements. RESULTS: There was significantly greater HT in dominant versus nondominant arm assessed by both palpation (5°±5, p=0.0004) and ultrasound (9°±11, p=0.0007). There was a positive correlation between both methods of HT measurement (r = 0.522, p=0.018). Palpation significantly underestimated HT as compared to US measurements (difference 4°±9, p=0.048). Difference in IR between shoulders correlated with HT measured by palpation (r=-0.651, p=0.002) and US (r=0.569, p=0.009). Increased ER in the dominant versus nondominant arm correlated with the side-to-side difference in HT measured by both palpation (r = 0.509, p=0.02) and US (r = 0.602, p=0.005). CONCLUSION: Greater HT on the dominant versus nondominant shoulder via palpation indicated this method can be used to assess HT in pitchers. HT assessed by palpation correlated with HT assessed by US. However, the magnitude of side-to-side difference in HT was smaller with palpation compared to US, and the two techniques should not be used interchangeably. Nevertheless, assessment of HT via palpation is a reliable and practical method and its use should be encouraged. LEVEL OF EVIDENCE: Level 3, measurement study.

Engagement of the Secondary Ligamentous and Meniscal Restraints Relative to the Anterior Cruciate Ligament Predicts Anterior Knee Laxity.

BACKGROUND: Patients with high-grade preoperative side-to-side differences in anterior laxity as assessed via the Lachman test after unilateral anterior cruciate ligament (ACL) rupture are at heightened risk of early ACL graft failure. Biomechanical factors that predict preoperative side-to-side differences in anterior laxity are poorly understood. PURPOSE: To assess, in a cadaveric model, whether the increase in anterior laxity caused by sectioning the ACL (a surrogate for preoperative side-to-side differences in anterior laxity) during a simulated Lachman test is associated with two biomechanical factors: (1) the tibial translation at which the secondary anterior stabilizers, including the remaining ligaments and the menisci, begin to carry force, or engage, relative to that of the ACL or (2) the forces carried by the ACL and secondary stabilizers at the peak applied anterior load. STUDY DESIGN: Controlled laboratory study. METHODS: Seventeen fresh-frozen human cadaveric knees underwent Lachman tests simulated through a robotic manipulator with the ACL intact and sectioned. The net forces carried by the ACL and secondary soft tissue stabilizers (the medial meniscus and all remaining ligaments, measured as a whole) were characterized as a function of anterior tibial translation. The engagement points of the ACL (with the ACL intact) and each secondary stabilizer (with the ACL sectioned) were defined as the anterior translation at which they began to carry force, or engaged, during a simulated Lachman test. Then, the relative engagement point of each secondary stabilizer was defined as the difference between the engagement point of each secondary stabilizer and that of the ACL. Linear regressions were performed to test each association (P < .05). RESULTS: The increase in anterior laxity caused by ACL sectioning was associated with increased relative engagement points of both the secondary ligaments (ß = 0.87; P < .001; R2 = 0.75) and the medial meniscus (ß = 0.66; P < .001; R2 = 0.58). Smaller changes in anterior laxity were also associated with increased in situ medial meniscal force at the peak applied load when the ACL was intact (ß = -0.06; P < .001; R2 = 0.53). CONCLUSION: The secondary ligaments and the medial meniscus require greater anterior tibial translation to engage (ie, begin to carry force) relative to the ACL in knees with greater changes in anterior laxity after ACL sectioning. Moreover, with the ACL intact, the medial meniscus carries more force in knees with smaller changes in anterior laxity after ACL sectioning. CLINICAL RELEVANCE: Relative tissue engagement is a new biomechanical measure to characterize in situ function of the ligaments and menisci. This measure may aid in developing more personalized surgical approaches to reduce high rates of ACL graft revision in patients with high-grade laxity.

Return to sports after chronic anterior exertional compartment syndrome of the leg: Conservative treatment versus surgery.

AIM: To evaluate whether surgical treatment for anterior chronic exertional compartment syndrome (CECS) of the lower leg will lead to full athletic activity recovery compared to conservative treatment. METHODS: Patients diagnosed with anterior CECS of the leg were offered surgical treatment, as surgery considered today to be the mainstay of treatment. Patients unwilling to be treated surgically were treated conservatively. They were followed up, assessing both groups for pain, functional status, and the Tegner sports activity score with comparisons at diagnosis and following treatment. RESULTS: Forty-three patients were treated for CECS (31; 72.1% with surgery and 12; 27.9% conservatively) with a mean follow-up of 28.15 (4.16-54.09) months. Reported pain improved at follow-up by 1.59 (0-6) points and by 4.27 ± (0-10) points in the conservatively and the surgically treated patient groups, respectively ( p = 0.014) with a mean change in the Tegner score of 0.09 (-5 to 5) and 3.22 (-4 to 7), respectively ( p = 0.009). Three patients in the conservatively treated group (25% of 12) and 24 patients in the operated group (77.4% of 31) reported full resumption of their pre-diagnosis activity level ( p = 0.001). CONCLUSION: This study supports surgery as the treatment of choice for anterior CECS of the leg with differential benefit for fasciotomy in terms of pain and return to pre-diagnosis athletic activity.

Lower Extremity Fractures in Hospitalized Pediatric Patients Following Road Traffic Accidents.

Lower extremity fractures (LEFs) caused by road traffic accidents (RTAs) can result in significant morbidity and account for a substantial part of nonfatal injuries requiring hospitalization. This study investigated the epidemiology of RTA-associated LEFs in the pediatric population. Based on the National Trauma Registry, data of 28,924 RTA hospitalized pediatric patients were reviewed. Data were analyzed according to LEF mechanism of injury, age distribution, fracture types, associated injuries, surgical treatment, and their interrelations.A total of 4970 (17.18%) sustained LEFs, with the highest risk for motorcycle-associated RTA, followed by pedestrians. Approximately 1 of 4 patients had multiple fractures. Forty percent (2184 cases) sustained additional injuries, for which car-associated RTAs were at the greatest risk (61%, P < 0.0001), followed by pedestrians and motorcycles (46%-45%, P < 0.0001). Overall, head/neck/face injuries were the most commonly associated injuries. The tibia was the most fractured bone (42%), followed by the femur, fibula, foot, and ankle. This distribution varied according to RTA mechanism. Forty-one percent of cases required fracture treatment in an operating room. As patients were older, the greater the chance they required further treatment in the operating room (P < 0.0001).This large-scale study on the epidemiology of LEFs in the pediatric population following RTA provides unique information on epidemiological characteristics of LEF, pertinent both to medical care providers and to health policy makers allocating resources and formulating prevention strategies in the attempt to deal with the burden of road traffic accidents.Level of Evidence: Prognostic and epidemiologic study, level II.

Coronal Knee Malalignment in Young Adults and Its Link to Body Measures.

Our aim was to report the prevalence of knee varus-valgus malalignment (KVVM) and its association with body mass index (BMI) and body height in a healthy and fit young adult population. Information on the disability codes associated with KVVM according to the Regulations of Medical Fitness Determination was retrieved from a medical database containing records of 17-year-old males and females before their recruitment into mandatory military service. Logistic regression models assessed the association between the BMI and body height to KVVM. The study cohort included 821,381 subjects (460,674 males and 360,707 females). The prevalence of KVVM was 0.9% in males and 0.6% for females. Under/overweight subjects were associated with higher prevalence of KVVM. The odds ratios (ORs) had a "J" curve pattern, increasing for underweight males and females, and even more so for above-normal BMIs (for obese males and for both overweight and obese females). The strongest association was between obese females and KVVM: an obese female had an OR of 22.864 (confidence interval [CI] = 20.683-25.725, p < 0.001) to have KVVM and an obese male had an OR of 4.483 (CI = 4.158-4.833 p < 0.001). When the BMI was analyzed as a continuous variable, each increase in one BMI unit was associated with an increase in OR of 7.6% for males and 24.1% for females. There is a strong association between BMI and KVVM in both underweight and overweight young adults. KVVM is more common in males, but most strongly associated with overweight and obese females.This is a Level III, case-control study.

Foot Width Changes Following Hallux Valgus Surgery.

BACKGROUND: Hallux valgus (HV) adversely affects quality of life. Patients frequently express concerns regarding postoperative foot appearance, foot width and footwear anticipations. However, only scarce data are available regarding postoperative foot width. MATERIALS AND METHODS: Seventy-one cases with moderate to severe HV treated with scarf osteotomy were included. The average age was 55.7 years (range, 20-76), with average follow-up of 20.7 months (range, 6-96). Patients' medical records were reviewed for demographic, operative, and radiographic data. Foot width was assessed radiographically by measuring both bone (distance between the first and fifth metatarsal heads) and soft tissue width (maximal distance of the soft tissue outline). RESULTS: Preoperative HV deformity (mean hallux valgus angle [HVA] 35.8 degrees, intermetatarsal angle [IMA] 14.1 degrees, and distal metatarsal articular angle [DMAA] 15.2 degrees) was successfully corrected (postoperative mean HVA 13.7 degrees, IMA 6.9 degrees, and DMAA 7.7 degrees). Overall bony foot width was reduced by 5% and soft tissue foot width by 2%. Further analysis showed that 13 feet (18.3%) had increased (>5%) bone width, 26 feet (36.6%) with no change (±5%), and 32 feet (45.1%) for which the width decreased (>5%) postoperatively. Angular deformity (HVA, IMA, and DMAA) showed low correlation with postsurgery foot width. CONCLUSION: HV surgery effect on foot width was very limited, overall reducing foot width by 2%. Furthermore, in only about half of the patients, the postoperative foot width decreased, regardless of angular deformity magnitude. Patients with the widest feet had a decrease in foot width following surgery, whereas patients with the narrowest feet had an increase in foot width. LEVEL OF EVIDENCE: Level III, comparative series.

New parameters describing how knee ligaments carry force in situ predict interspecimen variations in laxity during simulated clinical exams.

Knee laxity, defined as the net translation or rotation of the tibia relative to the femur in a given direction in response to an applied load, is highly variable from person to person. High levels of knee laxity as assessed during routine clinical exams are associated with first-time ligament injury and graft reinjury following reconstruction. During laxity exams, ligaments carry force to resist the applied load; however, relationships between intersubject variations in knee laxity and variations in how ligaments carry force as the knee moves through its passive envelope of motion, which we refer to as ligament engagement, are not well established. Thus, the objectives of this study were, first, to define parameters describing ligament engagement and, then, to link variations in ligament engagement and variations in laxity across a group of knees. We used a robotic manipulator in a cadaveric knee model (n=20) to quantify how important knee stabilizers, namely the anterior and posterior cruciate ligaments (ACL and PCL, respectively), as well as the medial collateral ligament (MCL) engage during respective tests of anterior, posterior, and valgus laxity. Ligament engagement was quantified using three parameters: (1) in situ slack, defined as the relative tibiofemoral motion from the neutral position of the joint to the position where the ligament began to carry force; (2) in situ stiffness, defined as the slope of the linear portion of the ligament force-tibial motion response; and (3) ligament force at the peak applied load. Knee laxity was related to parameters of ligament engagement using univariate and multivariate regression models. Variations in the in situ slack of the ACL and PCL predicted anterior and posterior laxity, while variations in both in situ slack and in situ stiffness of the MCL predicted valgus laxity. Parameters of ligament engagement may be useful to further characterize the in situ biomechanical function of ligaments and ligament grafts.

Orthopaedic injuries among electric bicycle users.

INTRODUCTION: The use of electric bicycles (E-bike) has dramatically increased. E-bikes offer convenient, environmental-friendly, and less expensive alternative to other forms of transport. However, E-bikes provide a new public health challenge in terms of safety and injury prevention. This study is the first to specifically investigate the E-bike related orthopaedic injuries, based on a national trauma registry. METHODS: Data from a National Trauma Registry were reviewed for patients hospitalized following E-bike related injuries. Between Jan 2014 to Dec 2015, a total of 549 patients were reviewed. Data were analyzed according to demography, type of orthopaedic injury, associated injuries and severity, injury mechanism and treatment in the operating room. RESULTS: A total of 360 (65%) patients sustained orthopaedic injuries, out of them 230 (63.8%) sustained limb/pelvis/spine fractures. Lower extremity fractures were more prevalent than upper extremity fractures (p<0.001). The tibia was the most fractured bone (19.2%). Patients over the age of 50 years were at the highest risk for spine (20. 5%, p=0.0001), pelvis (15.9%, p=0.0001) and femoral neck (15.9%, p=0.0172) fractures relative to other age groups. Approximately 42% of patients sustained associated injuries, with head/neck/face injuries being the most prevalent (30.3%). followed by chest (11.9%) and abdominal injury (13.3%). A collision between E-bike and a motorized vehicle was the mechanism of injury in 35% of cases. In this mechanism of injury, patients had 1.7 times the risk for associated injuries (p<0.0001) and the risk for major trauma (ISS score ≥16) was more than the double (p=0.03). One third of patients with orthopaedic injuries required treatment in the operating room. Treatment varied depending on the type of fracture. CONCLUSIONS: This study provides unique information on epidemiological characteristics of orthpaedic injuries caused be E-bikes, pertinent both to medical care providers, as well as to health policy-makers allocating resources and formulating prevention strategies.

High Interspecimen Variability in Engagement of the Anterolateral Ligament: An In Vitro Cadaveric Study.

BACKGROUND: Anterolateral ligament (ALL) reconstruction as an adjunct to anterior cruciate ligament (ACL) reconstruction remains a subject of clinical debate. This uncertainty may be driven in part by a lack of knowledge regarding where, within the range of knee motion, the ALL begins to carry force (engages). QUESTIONS/PURPOSES: (1) Does the ALL engage in the ACL-intact knee; and (2) where within the range of anterior tibial translation occurring in the ACL-sectioned knee does the ALL engage? METHODS: A robotic manipulator was used to measure anterior tibial translation, ACL forces, and ALL forces in 10 fresh-frozen cadaveric knees (10 donors; mean age, 41 ± 16 years; range, 20-64 years; eight male) in response to applied multiplanar torques. The engagement point of the ALL was defined as the anterior tibial translation at which the ALL began to carry at least 15% of the force carried by the native ACL; a threshold of 15% minimized the sensitivity of the engagement point of the ALL. This engagement point was compared with the maximum anterior tibial translation permitted in the ACL-intact condition using a paired Wilcoxon signed-rank test (p < 0.05). Normality of each outcome measure was confirmed using Kolmogorov-Smirnov tests (p < 0.05). RESULTS: The ALL engaged in five and four of 10 ACL-intact knees in response to multiplanar torques at 15° and 30° of flexion, respectively. Among the nine of 10 knees in which the ALL engaged with the ACL sectioned, the ACL-intact motion limit, and ALL engagement point, respectively, averaged 1.5 ± 1.1 mm and 5.4 ± 4.1 mm at 15° of flexion and 2.0 ± 1.3 mm and 5.7 ± 2.7 mm at 30° of flexion. Thus, the ALL engaged 3.8 ± 3.1 mm (95% confidence interval [CI], 1.4-6.3 mm; p = 0.027) and 3.7 ± 2.4 mm (95% CI, 2.1-5.3 mm; p = 0.008) beyond the maximum anterior tibial translation of the ACL-intact knee at 15° and 30° of flexion, respectively. CONCLUSIONS: In this in vitro, cadaveric study, the ALL engaged in up to half of the ACL-intact knees. In the ACL-sectioned knees, the ALL engaged beyond the ACL-intact limit of anterior subluxation on average in response to multiplanar torques, albeit with variability that likely reflects interspecimen heterogeneity in ALL anatomy. CLINICAL RELEVANCE: The findings suggest that surgical variables such as the joint position and tension at which lateral extraarticular grafts and tenodeses are fixed might be able to be tuned to control where within the range of knee motion the graft tissue is engaged to restrain joint motion on a patient-specific basis.

The Prevalence of Cruciate Ligament and Meniscus Knee Injury in Young Adults and Associations with Gender, Body Mass Index, and Height a Large Cross-Sectional Study.

Anterior cruciate ligament and meniscal injuries are associated with secondary osteoarthrosis which may lead to functional impairment and economic burden. The prevalence of knee injury has not been studied in depth. Our purpose was to report the prevalence of knee ligament and meniscal injuries and their associations with gender, body mass index (BMI), and height in young adults and to characterize individuals with meniscal injuries who gained full recovery. A cross-sectional, population-based study was conducted. Information on the disability codes of knee ligament and meniscal injury according to the Regulations of Medical Fitness Determination was retrieved from a medical database containing records of young prerecruits into mandatory service. Logistic regression assessed the association between genders, BMI, and body height to knee injuries. A total of 825,187 subjects were included. Prevalence of knee injuries was 0.35%. Males had 2.2-fold more knee injuries than females. Increased BMI was associated with increased prevalence of knee injury in both genders, more significantly in females (overweight and obese females had an odds ratio of 1.406 and 1.519, respectively, to suffer from concomitant meniscal and ligamentous knee injury). Being underweight was associated with a lower prevalence of knee injury. An above normal BMI was more significantly associated with meniscal and/or ligament injuries that did not fully recover (females > males). Body height was associated with isolated meniscal injury in both genders. We found an association between BMI, body height, and knee injury in both males and females. Higher body height and higher BMI might be risk factors for knee injuries. Higher BMI was associated with greater probability of disability coding. Meniscal and ligament injuries are more common among males.

Unicompartmental knee arthroplasty versus total knee arthroplasty: Which type of artificial joint do patients forget?

PURPOSE: During recent years, there has been an intensive growth of interest in the patient's perception of functional outcome. The Forgotten Joint Score (FJS) is a recently introduced score that measures joint awareness of patients who have undergone knee arthroplasty and is less limited by ceiling effects. The aim of this study was to compare the FJS between patients who undergo medial unicompartmental knee arthroplasty (UKA) and patients who undergo total knee arthroplasty (TKA) 1 and 2 years post-operatively. METHODS: This prospective study compares the FJS at a minimum of one (average 1.5 years, range 1.0-1.9) and a minimum of 2 years (average 2.5 years, range 2.0-3.6) post-operatively between patients who underwent medial UKA and TKA. RESULTS: One-hundred and thirty patients were included. Sixty-five patients underwent medial UKA and 65 patients underwent TKA. At both follow-up points, the FJS was significantly higher in the UKA group (FJS 1 year 73.9 ± 22.8, FJS 2 year 74.3 ± 24.8) in contrast to the TKA group (FJS 1 year 59.3 ± 29.5 (p = 0.002), FJS 2 year 59.8 ± 31.5, (p = 0.004)). No significant improvement in the FJS was observed between 1- and 2-year follow-up of the two cohorts. CONCLUSION: Patients who undergo UKA are more likely to forget their artificial joint in daily life and consequently may be more satisfied. LEVEL OF EVIDENCE: II.

Biomechanical Assessment of the Anterolateral Ligament of the Knee: A Secondary Restraint in Simulated Tests of the Pivot Shift and of Anterior Stability.

BACKGROUND: Injury to the lateral capsular tissues of the knee may accompany rupture of the anterior cruciate ligament (ACL). A distinct lateral structure, the anterolateral ligament, has been identified, and reconstruction strategies for this tissue in combination with ACL reconstruction have been proposed. However, the biomechanical function of the anterolateral ligament is not well understood. Thus, this study had two research questions: (1) What is the contribution of the anterolateral ligament to knee stability in the ACL-sectioned knee? (2) Does the anterolateral ligament bear increased load in the absence of the ACL? METHODS: Twelve cadaveric knees from donors who were a mean (and standard deviation) of 43 ± 15 years old at the time of death were loaded using a robotic manipulator to simulate clinical tests of the pivot shift and anterior stability. Motions were recorded with the ACL intact, with the ACL sectioned, and with both the ACL and anterolateral ligament sectioned. In situ loads borne by the ACL and anterolateral ligament in the ACL-intact knee and borne by the anterolateral ligament in the ACL-sectioned knee were determined. RESULTS: Sectioning the anterolateral ligament in the ACL-sectioned knee led to mean increases of 2 to 3 mm in anterior tibial translation in both anterior stability and simulated pivot-shift tests. In the ACL-intact knee, the load borne by the anterolateral ligament was a mean of ≤10.2 N in response to anterior loads and <17 N in response to the simulated pivot shift. In the ACL-sectioned knee, the load borne by the anterolateral ligament increased on average to <55% of the load normally borne by the ACL in the intact knee. However, in the ACL-sectioned knee, the anterolateral ligament engaged only after the tibia translated beyond the physiologic limits of motion of the ACL-intact knee. CONCLUSIONS: The anterolateral ligament is a secondary stabilizer compared with the ACL for the simulated Lachman, anterior drawer, and pivot shift examinations. CLINICAL RELEVANCE: Since the anterolateral ligament engages only during pathologic ranges of tibial translation, there is a limited need for anatomical reconstruction of the anterolateral ligament in a well-functioning ACL-reconstructed knee.