Anterior Subluxation Research Articles

Lateral Meniscus Posterior Root Lesion Influences Anterior Tibial Subluxation of the Lateral Compartment in Extension After Anterior Cruciate Ligament Injury

Background: The lateral meniscus posterior root (LMPR) lesion further decreases dynamic knee stability after anterior cruciate ligament (ACL) injury owing to the loss of the “wedge effect” maintained by the posterior horn of the lateral meniscus. However, the effect of LMPR lesions on the static tibiofemoral relationship in extension after ACL injuries is not determined. Purpose: To (1) determine the effect of LMPR lesions on anterior tibial subluxation of the lateral compartment (ATSLC) in extension in patients with ACL injuries and to (2) identify the LMPR-related factors associated with excessive ATSLC in extension. Study Design: Cohort study; Level of evidence, 3. Methods: Between January 2015 and December 2017, 405 consecutive patients with diagnosed ACL injuries who underwent primary ACL reconstructions were retrospectively reviewed. Among them, 45 patients with combined ACL injuries and LMPR lesions (ACL+LMPR group) and 51 patients with isolated ACL injuries (ACL group) were identified. Values of ATSLC in extension were measured on preoperative supine magnetic resonance imaging and classified into high grade (≥6 mm) and low grade (<6 mm). The mean ATSLC in extension and the proportion of patients with high-grade ATSLC in extension were compared between the groups by univariate analysis. In the ACL+LMPR group, predictors of high-grade ATSLC in extension—including age, sex, body mass index, affected side, cause of injury, period from injury (<12 or ≥12 weeks), LMPR lesion pattern (radial tear or root avulsion), and meniscofemoral ligament integrity (intact or impaired)—were assessed by univariate analysis and multivariate logistic regression analysis. Results: The mean ATSLC in extension in the ACL+LMPR group was significantly greater than that in the ACL group (5.6 mm vs 3.1 mm; P = .001). The proportion of patients with high-grade ATSLC in extension in the ACL+LMPR group was also significantly larger than that in the ACL group (44.4% vs 15.7%; P = .002). In addition, the root avulsion (instead of radial tear) (odds ratio, 28.750; 95% CI, 2.344-352.549; P = .009) and the period from injury ≥12 weeks (odds ratio, 17.095; 95% CI, 1.207-242.101; P = .036) were determined to be the 2 independent predictors of high-grade ATSLC in extension. However, age, sex, body mass index, affected side, cause of injury, and meniscofemoral ligament integrity were not. Conclusion: After ACL injuries, concomitant LMPR lesion further increased ATSLC in extension. Chronic LMPR avulsion was associated with high-grade ATSLC in extension.

Excessive Preoperative Anterior Tibial Subluxation in Extension Is Associated With Inferior Knee Stability After Anatomic Anterior Cruciate Ligament Reconstruction

Background: Anterior tibial subluxation (ATS) in extension after anterior cruciate ligament (ACL) injury highlights an increased anterior position of the tibia relative to the femur. Recent studies demonstrated that subluxation is sometimes irreducible and the normal tibiofemoral relationship is not restored by ACL reconstruction (ACLR), which raises concerns regarding clinical outcomes after ACLR. Hypothesis: Excessive preoperative ATS in extension is associated with inferior knee stability after anatomic ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: From March 2016 to January 2017, a total of 487 consecutive patients with clinically diagnosed noncontact ACL injuries who underwent primary anatomic ACLR were retrospectively analyzed. Of these patients, 430 met the criteria for inclusion in this study. Anterior subluxation of the lateral and medial compartments (ASLC and ASMC) in extension relative to the femoral condyles was measured on preoperative magnetic resonance imaging. Twenty patients (study group) who demonstrated excessive (>10 mm) ASLC and ASMC in extension were matched 1:2 to 40 participants (control group) who showed minimal or no (<3 mm) ASLC and ASMC in extension. The amount of ASLC and ASMC in extension relative to the femoral condyles at 2 years postoperatively was the primary outcome. Moreover, the Lysholm score, IKDC grade (International Knee Documentation Committee), and stability assessments (pivot-shift test and KT-1000 arthrometer side-to-side difference) were evaluated preoperatively and at the last follow-up visit. Results: The preoperative mean ASLC and ASMC in extension of the study group were both significantly larger than those of the control group (study group vs control group: ASLC, 13.5 mm vs 1.2 mm; ASMC, 12.4 mm vs 1.0 mm; P < .05). Moreover, patients in the study group showed significantly larger posterior tibial slope than the patients in the control group (17.8°± 2.5° vs 9.5°± 1.5°; P < .05). At the final follow-up visit, the mean ASLC and ASMC of the study group were 8.1 mm and 7.3 mm, which were significantly larger than those of the control group (ASLC, 0.9 mm; ASMC, 0.7 mm; P < .05). In addition, the study group showed inferior knee stability when compared with the control group in terms of both the pivot-shift test (study group vs control group: 2 grade 2, 10 grade 1, and 8 grade 0 vs 1 grade 1 and 39 grade 0; P < .05) and the KT-1000 arthrometer side-to-side difference (study group vs control group: 4.4 ± 1.2 mm vs 1.5 ± 0.6 mm; P < .05). Furthermore, the study group showed significantly lower mean Lysholm score (study group vs control group: 80.3 ± 6.3 vs 93.3 ± 4.3, P < .05) and IKDC grading results (study group vs control group: 3 grade C, 16 grade B, and 1 grade A vs 3 grade B and 37 grade A; P < .05) as compared with the control group. Conclusion: In this short-term study, the excessive (>10 mm) preoperative ATS in extension after ACL injury was associated with inferior knee stability after anatomic ACLR.

Risk factors for passive anterior tibial subluxation on MRI in complete ACL tear

IntroductionIn anterior cruciate ligament (ACL) tear, passive spontaneous anterior tibial subluxation (ATS), with respect to the femur, is sometimes observed on MRI. In a case-control study, ATS>3.5mm showed 100% specificity (±3.6, 95% CI) for complete ACL tear. The aim of the present study was to assess the relation between ATS on MRI and associated lesions in complete ACL tear. The study hypothesis was that associated lesions are a risk factor for ATS. Material and methodsA retrospective study included patients operated on for complete ACL tear between 2010 and 2015. Exclusion criteria comprised associated posterior cruciate ligament tear, partial ACL tear, and history of knee surgery. Preoperative MRI was performed with the patient in supine position and the knee in 20° flexion in neutral rotation. ATS was measured by axial superimposition of the bicondylar slice on the slice through the tibial plateau. Associated lesions were assessed: medial and lateral menisci, collateral ligaments, posteromedial and posterolateral corners, tibiofemoral compartment cartilage and cancellous bone. Factors associated with ATS>3.5mm were analyzed. Ninety-one patients were included: mean age, 31.1±10.1 years; 34 female, 57 male. Mean time from injury to MRI was 7.8±11.7 months (range, 0.7–60 months). ResultsMean ATS was 4.7±2.3mm. Inter- and intra-observer reproducibility for ATS measurement were excellent. On preoperative MRI, 61.1% of patients showed bone edema, 48.4% medial meniscal tear, and 36.3% lateral meniscal tear. ATS was significantly greater in case of medial meniscal tear (5.4±2.3mm vs. 4±2.1mm; p=0.003). No significant differences were found according to other lesions. Fifty-four patients (59.3%) showed ATS>3.5mm; risk factors comprised medial meniscal tear (OR=2.6, 95%CI [1.1–6.2]; p=0.03) and injury-to-MRI time>9 months (OR=9.8, 95% CI [1.1–85.2]; p=0.04). ConclusionSpontaneous anterior tibial subluxation on MRI in complete ACL tear was significantly associated with medial meniscal tear and accident-to-MRI time. Level of evidenceIV, retrospective cohort study.

Biomechanical function of the anterolateral ligament of the knee: a systematic review

BackgroundIt has been suggested that the anterolateral ligament (ALL) is an important anterolateral stabilizer of the knee joint which functions to prevent anterolateral subluxation and anterior subluxation at certain flexion angles in the knee.PurposeTo analyze and systematically interpret the biomechanical function of the ALL.MethodsAn online search was conducted for human cadaveric biomechanical studies that tested function of the ALL in resisting anterolateral subluxation and anterior subluxation of the knee. Two reviewers independently searched Medline, Embase, and the Cochrane Database of Systematic Reviews for studies up to 25 September 2018. Biomechanical studies not reporting the magnitude of anterior tibial translation or tibial internal rotation in relation to the function of the ALL were excluded.ResultsTwelve biomechanical studies using human cadavers evaluating parameters including anterior tibial translation and/or internal tibial rotation in anterior cruciate ligament (ACL)-sectioned and ALL-sectioned knees were included in the review. Five studies reported a minor increase or no significant increase in anterior tibial translation and internal tibial rotation with further sectioning of the ALL in ACL-deficient knees. Five studies reported a significant increase in knee laxity in tibial internal rotation or pivot shift with addition of sectioning the ALL in ACL-deficient knees. Two studies reported a significant increase in both anterior tibial translation and internal tibial rotation during application of the anterior-drawer and pivot-shift tests after ALL sectioning.ConclusionThere was inconsistency in the biomechanical characteristics of the ALL of the knee in resisting anterolateral and anterior subluxation of the tibia.

Epidemiology of Shoulder Instability Injuries in Collision Collegiate Sports From 2009 to 2014

To describe the types, mechanisms, and severity of shoulder instability injuries in collegiate collision athletes during the 2009-2010 through 2013-2014 academic years using the National Collegiate Athletic Association Injury Surveillance Program; to compare the injury incidence between men's collision sports and their women's non-collision counterparts, when possible; and to compare injury outcomes between Divisions I, II, and III. Data regarding men's football, wrestling, ice hockey, and lacrosse, as well as women's ice hockey and lacrosse, were obtained. Injuries requiring attention from a health care provider were reported. Incidence rates per 100,000 athlete-exposures (AEs) were calculated with 95% confidence intervals (CIs). Analysis of variance was used to compare time loss (TL), and χ2 analysis was used to compare surgery rates between divisions. A total of 445 shoulder instability injuries occurred in 1,421,561 AEs from 2009-2010 to 2013-2014 (incidence rate, 31.30 injuries/100,000 AEs; 95% CI, 28.4-34.21 injuries/100,000 AEs). Subluxation accounted for 59.1% of injuries, with anterior subluxation (35.3%) being the most common injury. Dislocation resulted in the most TL per injury (17.58days). Mean TL for all injuries was 8.17days (standard deviation, 7.21days). When non-time-loss injuries were excluded from analysis, players experienced a mean TL of 18.34days (standard deviation, 8.44days). Divisions I (4.77days), II (20.52days), and III (11.23days) differed significantly in mean TL (P= .01). Of the injuries, 29.3% required surgery. The surgery rates for Divisions I (32.9%), II (38.1%), and III (19.4%) also differed significantly (P= .04). Men's ice hockey and lacrosse players sustained a 2.17-fold (95% CI, 1.04-4.50) higher incidence of shoulder instability than their female counterparts. Anterior subluxation and dislocation accounted for 52.1% of all shoulder instability injuries. Injured athletes missed 8days on average, and nearly 30% of injuries required surgery. Surgery rates and TL were significantly different between Divisions I, II, and III. Female athletes playing non-collision ice hockey and lacrosse experienced significantly lower shoulder instability rates than their male counterparts. Level III, retrospective cohort study.

Latissimus Dorsi Transfer for Irreparable Subscapularis Tear

The purpose of this study is to report the outcome of latissimus dorsi transfer to reconstruct an irreparable subscapularis tear. Irreparable subscapularis tears is associated with marked shoulder dysfunction and morbidity. Given the variable outcomes with pectoralis major transfer or graft augmented reconstruction, leaving many patients with a reverse shoulder arthroplasty as their only surgical option. Conversely to the pectoralis major, the latissimus dorsi (LD) line of pull is posterior to the body’s axis, in the same direction as the subscapularis. Although LD transfer has been described for posterosuperior rotator cuff tears, there is a paucity of information on LD transfer for subscapularis insufficiency. Seventy-two consecutive patients with irreparable subscapularis tears who underwent latissimus dorsi transfer. Sixteen of these patients had a prior failed latarjet and subsequently required additional bone grafting, and were excluded. Therefore, 56 patients were included in this study. The average age of 53 years (range, 37-79), with 39 (70%) males, and 30 (54%) performed in the dominant extremity. Every patient had a prior surgery, with a mean number 2 (range, 1-5). Concomitant pathologies included a supraspinatus tear in 37, upper infraspinatus tear in 11, and mild arthritis in 7 shoulders. On radiographic evaluation, 38 patients had evidence of proximal migration, while 27 had anterior subluxation. The surgical technique included open repair in 14 shoulders and arthroscopic repair in 42 shoulders. Outcome measures included visual pain analogue score (VAS), range of motion (ROM), subjective shoulder value (SSV), and Constant shoulder score. At a mean 13 months follow-up (7-51 months), patients had significant improvements in their pain, flexion, abduction, internal rotation, SSV, and Constant scores when compared to preoperatively (p<0.03). There was an improved subjective lift off test in all patients, but only 12 patients had a complete reversal of the lift off test. Belly press test improved in 43 patients, but similar to lift off, only 16 patients had a complete reversal of the belly press test. At final follow-up, 10 of 38 patients continued to have proximal migration, while 3 of 27 patients continued to have evidence of anterior subluxation. Of note, the patients with frank anterior escape had a higher likelihood of having proximal migration and anterior subluxation, but this was no statistically significant. There was no progression of arthritis stages at final follow-up. Revision surgeries included 2 patients revised to a reverse shoulder arthroplasty for rupture of the tendon transfer. Furthermore, 3 patients had LD transfer ruptures, but did not elect to undergo further surgery. Latissimus dorsi transfer for irreparable subscapularis tears has the potential to lead to clinical improvements in patients shoulder function. At final follow-up, most patients improve in many of the signs of subscapularis insufficiency, including anterior and/or proximal subluxation, clinical examination maneuvers and shoulder function. Overall, this transfer represents a reasonable option for this difficult pathology.

Matrix Metalloproteinase Inhibition With Doxycycline Affects the Progression of Posttraumatic Osteoarthritis After Anterior Cruciate Ligament Rupture: Evaluation in a New Nonsurgical Murine ACL Rupture Model

Background: Doxycycline has broad-spectrum activity as a matrix metalloproteinase (MMP) inhibitor and thus could reduce the progression of posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament (ACL) rupture. Hypothesis: Doxycycline would inhibit progression of PTOA in a murine ACL rupture model. Study Design: Controlled laboratory study. Methods: For the in vitro study, cadaveric C57BL/6 male mice knees (N = 108) were used for the development of a nonsurgical ACL rupture model. For the in vivo study, 24 C57BL/6 male mice then underwent ACL rupture with our manual procedure and were divided into 4 groups: untreated control; doxycycline, 10 mg/kg/d; doxycycline, 50 mg/kg/d; and doxycycline, 100 mg/kg/d. Doxycycline was administered in drinking water beginning immediately after ACL rupture. Radiographic imaging and paw prints were evaluated at 3, 7, 14, and 28 days. The foot length and toe spread were analyzed as measures of function. Histology and MMP-13 immunohistochemistry were done at 4 weeks. Results: Radiographs demonstrated anterior tibial subluxation and meniscal extrusion after ACL rupture, confirming knee joint instability without fractures. Statistically significant differences in gait were found between the intact and experimental groups. Histologic examination demonstrated cartilage damage, meniscal tears, and mild osteoarthritis after ACL rupture, similar to what occurs in human patients. Hypertrophy of the posterior horn of the medial and lateral meniscus was found, and tears of the posterior horn of the menisci were common. All doxycycline groups had a lower score than the untreated control group, indicating less cartilage damage. The posterior tibia of the untreated group had the most cartilage damage as compared with the 3 doxycycline groups, with a significant difference between the untreated and 50-mg/kg/d doxycycline groups, suggesting that the latter dose may protect against proteoglycan loss and decrease the progression of osteoarthritis. The nondoxycycline group had the highest synovial inflammation score among all groups, indicating that doxycycline has an inhibitory effect on synovitis. There was significantly lower MMP-13 expression on the tibia in the doxycycline-treated groups, with a positive correlation between doxycycline concentration and MMP-13 inhibition. Conclusion: Modulation of MMP-13 activity by doxycycline treatment may offer a novel biological pathway to decrease the progression of PTOA after ACL rupture. Clinical Relevance: Doxycycline is an approved, readily available drug with infrequent side effects of photosensitivity and gastrointestinal symptoms. Future clinical trials could evaluate doxycycline to reduce or prevent progressive cartilage damage after ACL rupture.

A New Coracoclavicular Guider for Minimally Invasive Anatomic Coracoclavicular Reconstruction with Two TightRope Systems in Acute Acromioclavicular Joint Dislocation

High-grade injuries of complete acromioclavicular (AC) joint disruption (types IV - VI) are typically treated surgically. Since the coracoclavicular (CC) ligament is most often used for stabilizing the AC joint, most reconstruction techniques to treat dislocation of this joint rely upon CC interval fixation. A TightRope system is usually used to augment the CC ligament to treat acute AC dislocations with arthroscopic assistance. The conventional arthroscopic technique employing one TightRope system is associated with some complications, including anterior subluxation of the clavicle and clavicular bony avulsion as a consequence of rotational movements. As an alternative, two TightRope systems can be used to anatomically reconstruct the CC ligament to avoid these complications. We present a new CC guider with which the surgeon can replicate the native CC ligament complex orientation using two TightRope systems via two minimally invasive incisions without arthroscopic assistance. This procedure relies upon the accommodation and stable placement of the clavicle and coracoid bone tunnels for the two TightRope systems in place of the trapezoid and conoid of the CC ligament. We retrospectively reviewed the outcomes for 16 patients with acute dislocation of the AC joint that had been treated by a single surgeon using a double-button fixation system. An independent reviewer conducted functional testing of these patients, including the use of Disability of Arm, Shoulder and Hand (DASH), Constant and visual analog scale (VAS) scores. Standard radiographs were used for assessing the CC distance for the impacted shoulder relative to that of the unaffected contralateral shoulderThe new CC guider leads to an excellent cosmetic result. Our clinical results show that this technique can be easily performed and is similarly invasive to other current arthroscopic techniques.

The relationship of the acromion to the distal clavicle in normal and symptomatic degenerated acromioclavicular joints.

Although degenerative osteoarthritis of the acromioclavicular joint is a common finding on technical investigations, not every patient experiences pain or function loss. The difference between symptomatic and asymptomatic patients is currently not elucidated. Therefore, we want to investigate the acromioclavicular relationship in normal, asymptomatic, and symptomatic degenerated ACJ. 84 normal ACJ, 39 asymptomatic degenerated ACJ, and 30 symptomatic degenerated ACJ were 3D reconstructed. The morphological dimensions and the relationship of the acromion and distal clavicle were measured using computational software. The reproducibility of this technique was evaluated using inter- and intra-observer reliability. The mean anteroposterior and superoinferior distance of both the clavicle and acromion was significantly larger in asymptomatic and symptomatic degenerative ACJ compared to the normal ACJ (p < 0.001). In symptomatic osteoarthritic ACJ, both the anterior and posterior borders of the acromion were significantly more anterior to the borders of the clavicle than in the normal group and asymptomatic group (p < 0.001). Subsequent ROC curve analysis resulted in a sensitivity of 86.7% and a specificity of 88.6% for anterior subluxation of the ACJ. This technique showed an excellent inter- and intra-observer reliability. In patients with degenerative ACJ, both the distal clavicle and acromion are enlarged. In asymptomatic patients, the AC relationship is the same as in normal patients, in contrast, in patients with symptomatic degenerative ACJ, the acromion is subluxated anteriorly compared to the clavicle.

Apparent diffusion coefficient as an indicator of spinal cord compression due to anterior atlanto-axial subluxation in rheumatoid arthritis patients

PurposeThe aim of this retrospective study was to evaluate the apparent diffusion coefficient (ADC) as a potential parameter of spinal cord damage in cervical spine instability at the atlanto-axial level in rheumatoid arthritis (RA) patients.MethodsOne hundred and six RA patients were included in the study. MRI examinations were performed with 1.5T scanner. The ADC was measured at six locations in the cervical spinal cord at the height of the first six cervical vertebrae (from C-1 to C-6). The ADC values were assessed in 2 groups: with and without anterior atlanto-axial subluxation (AAS) diagnosed on plain radiographs. Correlations between ADC values and radiographic measurements and RA activity indicators were evaluated.ResultsThe ADC values at C1 level (ADC1) was higher in the group with anterior AAS than in the group without AAS (p < 0.001). Statistically significant moderate positive correlation between ADC1 and anterior atlanto-axial diameter interval AADI (rho = 0.58; p < 0.008) was found as well as statistically significant weak negative correlation between ADC1 and posterior atlanto-axial diameter interval PADI (rho = − 0.34; p < 0.008).ConclusionsThe conducted study demonstrates the applicability of the ADC maps in the identification of spinal cord compression due to anterior AAS in RA patients. The results encourage the practical use of the ADC as an additional parameter in the qualification for surgical treatment.Graphic abstractThese slides can be retrieved under Electronic Supplementary Material.

Static Lateral Tibial Plateau Subluxation Predicts the Grade of Rotatory Knee Laxity in ACL-Deficient Knees

Objectives: In anterior cruciate ligament-deficient (ACL-D) knees, injury pattern and bony morphology have been shown to influence both static anterior tibial subluxation relative to the femur and dynamic rotatory knee laxity. Therefore, the relationship between static anterior tibial subluxation and dynamic rotatory knee laxity was investigated. The goal of this study was to determine if static tibial subluxation as measured on magnetic resonance imaging (MRI) was associated with the grade of rotatory knee laxity in ACL-D knees. Methods: Two-hundred and fifty-eight knees underwent preoperative, image-guided assessment of lateral knee compartment translation during quantitative pivot shift (QPS). Subluxations of the medial and lateral tibial plateaus were measured on preoperative MRI in a subset of primary ACL-D knees meeting criteria for high-grade (QPS &gt; 5.2 mm) and low-grade (QPS &lt; 2.4 mm) rotatory laxity. Tibial subluxations on MRI were compared between patients with high- and low-grade rotatory laxity using pairwise t-test, and analyzed using uni- and multivariate logistic regression. Significance was set at p&lt;0.05. Results: On MRI, greater anterior subluxation of the lateral tibial plateau was observed in patients with high-grade compared to low-grade rotatory knee laxity (4.5 mm vs. 2.3 mm; p&lt;0.05). No similar relationship was observed for the medial tibial plateau (-0.9 mm vs. -0.4 mm; p&gt;0.05). Univariate logistic regression demonstrated that static subluxation of the lateral tibial plateau was associated with high-grade rotatory knee laxity (Odds ratio [OR] 1.2; p&lt;0.05). An optimal cut-off of 2.95 mm of static lateral tibial subluxation was associated with high-grade rotatory knee laxity (sensitivity: 75%; specificity: 63%). Lateral meniscus injury was the first variable to enter a multivariate regression analysis and proved to be most associated with high-grade rotatory knee laxity ([OR] 6.8; p &lt; 0.05). When lateral meniscus injury was excluded from multivariate regression analysis, static anterior subluxation of the lateral tibial plateau alone was associated with high-grade rotatory knee laxity ([OR] 1.2; p&lt;0.05). Conclusion: Data from this MRI study of two distinct rotatory knee laxity groups showed that static anterior subluxation of the lateral tibial plateau of 2.95 mm or greater was associated with high-grade rotatory knee laxity, and each millimeter increase of lateral tibial plateau subluxation was associated with a 1.2-fold odds of high-grade rotatory knee laxity. Anterior subluxation of the lateral tibial plateau on MRI was not independently associated with high-grade rotatory knee laxity in the presence of concomitant lateral meniscus injury. Static measurements made pre-operatively may aid in predicting high-grade rotatory knee laxity and refining the indications for individualized knee surgery.

Impact of the occiput and external acoustic meatus to axis angle on dysphagia in patients suffering from anterior atlantoaxial subluxation after occipitocervical fusion

BACKGROUND CONTEXTDysphagia is a complication that sometimes occurs after occipitocervical fusion (OCF). An appropriate O-C2 angle (O-C2a) is recognized as a critical factor for preventing dysphagia. The occiput and external acoustic meatus to axis angle (O-EAa) has some advantages over the O-C2a and is now recognized to outperform O-C2a in predicting dysphagia. However, there are no data on this topic from patients with anterior atlantoaxial subluxation (AAS). PURPOSETo evaluate the relationship between the O-EAa and dysphagia in patients suffering from AAS after OCF surgery. STUDY DESIGNA retrospective clinical study. PATIENT SAMPLEData from 22 consecutive AAS patients who had undergone OCF were reviewed retrospectively. OUTCOME MEASURESThe outcome measures included the O-EAa, O-C2a, the narrowest oropharyngeal airway space (nPAS), and the morbidity of dysphagia after OCF. METHODSBetween September 2011 and September 2017, data from 22 consecutive AAS patients who had undergone OCF were reviewed retrospectively. The patients were divided into two groups according to whether they had suffered postoperative dysphagia by face-to-face questioning or telephone interview. Lateral radiographs were analyzed to determine the pre- and postoperative O-EAa, O-C2a, angle formed by the inferior endplate of C2 and the EA-line (C2Ta), and smallest anteroposterior diameter of the oropharynx between the levels of the uvula and the tip of the epiglottis (nPAS). RESULTSThe incidence of dysphagia after OCF was 18.18% (4/22). The pre- and postoperative mean nPAS values were significantly different between the groups (p<.05). The postoperative mean O-EAa of the group with dysphagia was significantly smaller than that of the group without dysphagia (p<.05). The mean change in nPAS was significantly larger in the group with dysphagia than that in the group without dysphagia (p<.05). The changes in the O-EAa, O-C2a, and nPAS were linearly correlated within patients. The marginal R2 values for the patients were 0.452 and 0.202 for the O-EAa and O-C2a, respectively. CONCLUSIONSThe O-EAa impacts dysphagia in patients with AAS after OCF. Measuring this angle intraoperatively may be a simple and effective procedure. The O-EAa may be used as a practical index to avoid postoperative dysphagia in patients with AAS after OCF.

Patients With Failed Anterior Cruciate Ligament Reconstruction Have an Increased Posterior Lateral Tibial Plateau Slope: A Case-Controlled Study

To compare knee anatomical parameters of patients with failed anterior cruciate ligament reconstruction (ACL-R) with those of a control group of sex-matched patients with successful ACL-R. Forty-three patients (34 male, 9female) who experienced graft failure after ACL-R were enrolled in the failed group. These patients were matched to a control group of 43 patients who underwent primary ACL-R with a minimum follow-up of 24months. On magnetic resonance imaging, the following parameters were evaluated: transepicondylar distance, lateral and medial femoral condyle widths, tibial plateau width, notch width index, and the ratio of width and height of the femoral notch, ratio between the height and depth of the lateral and medial femoral condyle, lateral and medial posterior tibial slopes, and anterior subluxation of the lateral and medial tibial plateau. Multivariate regression with backward elimination, including only the previously identified significant variables, defined the independent predictors for revision surgery. The anatomical variables that were significantly different between the 2 study groups were lateral and medial posterior tibial slopes, anterior subluxation of the lateral and medial tibial plateau, medial tibial plateau width, lateral tibial plateau width, medial femoral condyle width, and transepicondylar distance; however, the multivariate regression analysis identified the lateral posterior tibial slope (LTPs), the anterior subluxation of the medial tibial plateau, and the medial femoral condyle width as significant independent predictors (P < .05). The LPTs had the highest coefficient and the highest sensitivity (88%) and specificity (84%) to identify failures when considering the optimal cutoff value of 7.4°. Several anatomical parameters have been identified that differ significantly between patients with failed ACL-R and those without a documented failure. The most accurate predictor of ACL failure was an LTPs >7.4°, with a sensitivity of 88% and specificity of 84%. Surgeons should consider measuring LTPs during preoperative assessment of ACL-injured patients, and patients with values >7.4° should be considered at high risk of ACL-R failure. Level III retrospective prognostic trial.

Clinical outcome of closed reduction of cervical spine injuries in a cohort of Nigerians

A prospective observational study. To evaluate the effectiveness of closed reduction of cervical spine injuries (CSIs) using cervical traction and identify probable complications. Department of Neurological Surgery, University College Hospital, Ibadan, Nigeria. Consecutive CSIs managed by closed reduction using Gardener-Well's Tongs traction were prospectively analysed. The data included imaging and neurological examinations findings, Frankel grading, and extent of reduction. Reduction of 95% or more was deemed satisfactory. The primary outcome measures were extent/degree of reduction and neurologic status classified as improved, same, or worse. Other complications were taken as secondary outcome measures. Seventy-four patients, 49 males, mean age 35.2 years (SD 9.7) were included. In all, 78.4% presented within 72 hours of injury. In total, 85.1% had road traffic crashes. Anterior subluxation was seen in 86.5%. The degree of displacement was <25% in 36/74 (48.6%), 25-50% in 19/74 (25.7%), 50-75% in 8/74 (10.8%), and >75% in 11/74 (14.9%). Traction reduction was done after 7 days of injury in 52.7% and same day of injury in 1.4%. Reduction weight ranged from 2 kg to 60 kg. Reduction was satisfactory in 67.6% and failed in 32.4%. In all, 81.1% of patients remained neurologically the same, while 18.9% improved. Causes of failed reduction were facet lock (15), old injury (8), new-onset/worsening pain (3), and over-distraction (2). Complications of closed reduction were over-distraction (5), tong pull-out (2), new-onset/worsening pain (2), and skull perforation (1). Satisfactory closed reduction is feasible in patients with CSI and significant malalignment. The method is associated with few complications.

Three-dimensional characterization of the anteverted glenoid (type D) in primary glenohumeral osteoarthritis

The Walch classification describes glenoid morphology in primary arthritis. As knowledge grows, several modifications to the classification have been proposed. The type D, a recent modification, was defined as an anteverted glenoid with or without anterior subluxation. Literature on the anteverted glenoid in primary osteoarthritis is limited. The purpose of this study, therefore, was to analyze the anatomic characteristics of the type D glenoid on radiographs and computed tomography (CT). The shoulder arthroplasty databases from 3 institutions were examined to identify patients with primary glenohumeral osteoarthritis and glenoid anteversion (≥5°), with or without anterior subluxation. The type D study cohort consisted of 18 patients (3% of the osteoarthritis cohort) and was a mean of 70 years old, with 11 women and 7 men. All radiographs were reviewed, and computed tomography Digital Imaging and Communications in Medicine (National Electrical Manufacturers Association, Rosslyn, VA, USA) data were analyzed on validated 3-dimensional imaging software. Rotator cuff fatty infiltration, glenoid measurements (anteversion and inclination), and humeral head subluxation according to the scapular plane were determined. In the study cohort, the mean glenoid anteversion was 12° (range, 5°-24°), the mean inclination was 0°, and the mean anterior subluxation was 38% (range, 6%-56%). Eight patients (44%) had a biconcave glenoid with a posterosuperiorly positioned paleoglenoid and an anteroinferiorly positioned neoglenoid, and 10 patients had a monoconcave glenoid. Fatty infiltration of the rotator cuff muscles never exceeded Goutallier stage 2. The type D glenoid is an addition to the original Walch classification and is characterized by glenoid anteversion (≥5°), anteroinferior humeral head subluxation, and absence of severe subscapularis fatty infiltration.

Steep Posterior Tibial Slope, Anterior Tibial Subluxation, Deep Posterior Lateral Femoral Condyle, and Meniscal Deficiency Are Common Findings in Multiple Anterior Cruciate Ligament Failures: An MRI Case-Control Study

Background: Tibiofemoral anatomic parameters, such as tibial slope, femoral condyle shape, and anterior tibial subluxation, have been suggested to increase the risk of anterior cruciate ligament (ACL) reconstruction failure. However, such features have never been assessed among patients experiencing multiple failures of ACL reconstruction. Purpose: To compare the knee anatomic features of patients experiencing a single failure of ACL reconstruction with those experiencing multiple failures or with intact ACL reconstruction. Study: Case-control study; Level of evidence, 3. Methods: Twenty-six patients who experienced failure of revision ACL reconstruction were included in the multiple-failure group. These patients were matched to a group of 25 patients with failure of primary ACL reconstruction and to a control group of 40 patients who underwent primary ACL reconstruction with no failure at a minimum follow-up of 24 months. On magnetic resonance imaging (MRI), the following parameters were evaluated: ratio between the height and depth of the lateral and medial femoral condyles, the lateral and medial tibial plateau slopes, and anterior subluxation of the lateral and medial tibial plateaus with respect to the femoral condyle. The presence of a meniscal lesion during each procedure was evaluated as well. Anatomic, demographic, and surgical characteristics were compared among the 3 groups. Results: The patients in the multiple-failure group had significantly higher values of lateral tibial plateau slope (P < .001), medial tibial plateau slope (P < .001), lateral tibial plateau subluxation (P < .001), medial tibial plateau subluxation (P < .001), and lateral femoral condyle height/depth ratio (P = .038) as compared with the control group and the failed ACL reconstruction group. Moreover, a significant direct correlation was found between posterior tibial slope and anterior tibial subluxation for the lateral (r = 0.325, P = .017) and medial (r = 0.421, P < .001) compartments. An increased anterior tibial subluxation of 2 to 3 mm was present in patients with a meniscal defect at the time of the MRI as compared with patients who had an intact meniscus for both the lateral and the medial compartments. Conclusion: A steep posterior tibial slope and an increased depth of the lateral femoral condyle represent a common finding among patients who experience multiple ACL failures. Moreover, higher values of anterior subluxation were found among patients with repeated failure and those with a medial or lateral meniscal defect.

Analysis of anterior tibial subluxation to the femur at maximum extension in anterior cruciate ligament-deficient knees.

The factors affecting anterior tibial subluxation (ATS) have not yet been well examined. To assess the factors affecting ATS in anterior cruciate ligament (ACL)-deficient knees. One hundred twenty-four patients with unilateral ACL injuries were included. True lateral views of the ACL-deficient knee and contralateral normal knee were obtained during maximum extension using fluoroscopy under general anesthesia, and ATS was calculated as the side-to-side difference in the tibial position relative to the femur. Patients were divided into four groups according to the time from injury to surgery. To identify the factors affecting ATS, the following possible factors were assessed: (1) the time from injury to surgery, (2) presence of a medial meniscal injury, and (3) posterior tibial slope angle. There was a positive correlation between the ATS ratio and the time from injury to surgery ( r = 0.52). The ratio of the presence of a medial meniscus injury was significantly higher in patients who underwent anterior tibial subluxation reconstruction (ACL-R) more than 12 months after an injury than in other patients who underwent ACL-R within 12 months after an injury. The ATS ratio was significantly higher in patients with a medial meniscus injury than in those without a medial meniscus injury (5.6% vs. 4.1%). Our results suggested that ACL-R should be performed within 6 months after injury if surgeons prefer to avoid an increase in ATS in maximum knee extension and at the latest within 12 months to avoid medial meniscal injury at the time of ACL-R.

Ulnar osteotomy and the ilizarov mini-fixator for pediatric chronic monteggia fracture-dislocations.

Treatment of chronic Monteggia fracture-dislocations remains controversial in skeletally immature patients. The present study aimed to review the clinical outcomes of surgical treatment with an Ilizarov mini-fixator for chronic Monteggia fracture-dislocations in children. From April 2003 to March 2014, 5 pediatric patients (4 males, 1 female) with chronic Monteggia fracture-dislocation were treated with an Ilizarov mini-fixator at our institution. The median age at the time of surgery was 9 years (range 5–14 years), median duration from injury to surgery was 31 months (range 2–125 months), and median duration of follow-up was 12 months (range 11 months–10 years). All patients underwent opening wedge osteotomy of the proximal ulna followed by the application of an Ilizarov mini-fixator. Although closed reduction was attempted after ulnar osteotomy and application of the Ilizarov mini-fixator, open reduction of the radial head was required in all patients. In 4 patients, dense scar tissue in the radiocapitellar joint was excised to enable reduction of the radial head; the remaining patient had traumatic radioulnar synostosis, and underwent separation of the synostosis followed by anconeus interposition arthroplasty. No patient received bone grafting at the ulnar osteotomy site, repair or reconstruction of the annular ligament, or temporary fixation of the radial head with transarticular wire. The median period of external fixation was 10 weeks (range 8–13 weeks). Although there were no severe complications such as deep infection and neurovascular disturbance, asymptomatic radial head subluxation occurred in 2 patients. The patient with traumatic synostosis had residual posterior subluxation with limitation of forearm rotation, and another patient with radial head enlargement had residual anterior subluxation. The median postoperative ranges of motion in pronation, supination, extension, and flexion were 90°, 90°, 0°, and 140°, respectively. The median Kim's elbow performance score was 65 (range 50–75) preoperatively, which improved to 94 (range 80–100) at final follow-up. The outcome was rated as excellent in 4 cases, and good in 1. In pediatric chronic Monteggia fracture-dislocations, ulnar osteotomy followed by the application of an Ilizarov mini-fixator is a viable option that is less invasive than plate fixation.

Operative Setup to Improve Sagittal Syndesmotic Reduction: Technical Tip.

We analyzed the operative measures that may be used to reduce the likelihood of sagittal syndesmotic malreduction. Hence, we propose a simple technical tip to avoid sagittal plane malreduction of the fibula within the syndesmosis in ankle fractures. Supporting the leg under the heel should be avoided when performing syndesmotic reduction for unstable malleolar fractures, and support under the calf should be used instead. Our observations have been confirmed in 6 cadaver specimens. We observed that there was a significant anterior subluxation of the fibula when the leg was supported under the heel. No significant difference between the intact and unstable state was present when the leg was supported under the calf. In conclusion, during syndesmotic reduction and fixation in supine position, supporting the foot under the heel should be avoided.

Static Lateral Tibial Plateau Subluxation Predicts High-Grade Rotatory Knee Laxity in Anterior Cruciate Ligament–Deficient Knees

Background: In anterior cruciate ligament–deficient (ACL-D) knees, injury pattern and bony morphologic features have been shown to influence both static anterior tibial subluxation relative to the femur and dynamic rotatory knee laxity. Therefore, the relationship between static anterior tibial subluxation and dynamic rotatory knee laxity was investigated. Purpose: To determine whether static tibial subluxation as measured on magnetic resonance imaging (MRI) is associated with the grade of rotatory knee laxity in ACL-D knees. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Two-hundred fifty-eight knees underwent preoperative, image-guided assessment of lateral knee compartment translation during quantitative pivot shift (QPS). Subluxations of the medial and lateral tibial plateaus were measured on preoperative MRI in a subset of primary ACL-D knees meeting criteria for high-grade (QPS > 5.2 mm) and low-grade (QPS < 2.4 mm) rotatory laxity. Tibial subluxations on MRI were compared between patients with high- and low-grade rotatory laxity through use of pairwise t test and were analyzed via univariate and multivariate logistic regression. Significance was set at P < .05. Results: On MRI, greater anterior subluxation of the lateral tibial plateau was observed in patients with high-grade compared with low-grade rotatory knee laxity (4.5 mm vs 2.3 mm; P < .05). No similar relationship was observed for the medial tibial plateau (−0.9 mm vs −0.4 mm; P > .05). Univariate logistic regression demonstrated that static subluxation of the lateral tibial plateau was associated with high-grade rotatory knee laxity (odds ratio [OR], 1.2; P < .05). An optimal cutoff of 2.95 mm of static lateral tibial subluxation was associated with high-grade rotatory knee laxity (sensitivity, 75%; specificity, 63%). Lateral meniscal injury was the first variable entered into a multivariate regression analysis and proved to be most associated with high-grade rotatory knee laxity (OR, 6.8; P < .05). When lateral meniscal injury was excluded from multivariate regression analysis, static anterior subluxation of the lateral tibial plateau alone was associated with high-grade rotatory knee laxity (OR, 1.2; P < .05). Conclusion: Data from this MRI study of two distinct rotatory knee laxity groups showed that static anterior subluxation of the lateral tibial plateau of 2.95 mm or greater was associated with high-grade rotatory knee laxity, and each millimeter increase of lateral tibial plateau subluxation was associated with a 1.2-fold odds of high-grade rotatory knee laxity. Anterior subluxation of the lateral tibial plateau on MRI was not independently associated with high-grade rotatory knee laxity in the presence of concomitant lateral meniscal injury. Static measurements made preoperatively may aid in predicting high-grade rotatory knee laxity and refining the indications for individualized knee surgery.