Jerk Test Research Articles

Posterior Compression Test: a Provocative Test for Detecting Posterior Labral Tears.

The purpose is to assess the diagnostic accuracy of a provocative test coined as the 'posterior compression test' (PCT) in those with the suspected posterior labral tear or lesion. A total of 515 'arthroscopic labral repairs' were identified between April 2013 and September 2020. Excluding those with concomitant shoulder pathologies, and only including those with pre-operative documentation of the PCT and/or the Jerk test, 191 patients were included. For the purposes of the analyses, the patients were divided into 'non-posterior' labral tear group which included the anterior labral tears and/or the superior labral anterior-to-posterior (SLAP) tears, versus 'any posterior' labral tear group which included the isolated posterior labral tears, the SLAP tears with posterior extension and the pan-labral tears. When the PCT was performed for the isolated posterior labral tears, the sensitivity was 92.6% with the specificity of 86.5%. The positive predictive value and negative predictive value were 71.4-97%, respectively. The Jerk test's sensitivity was 77.8% but when the two tests were combined, the sensitivity increased up to 96.3%. The combined sensitivity with the Jerk test was still up to 94.6% with the AUC (area under curve) /ROC (receiver operator characteristic) at 0.855. Low 'false-positive' rate with the PCT was observed when the test was performed for the 'non-posterior' labral group, with the sensitivity of 13.5%. The posterior compression test correlated well with the arthroscopic diagnoses in a subset of patients with suspected posterior labral pathology, possibly by means of direct stimulation. III; Diagnostic Study.

Study of low-temperature interconnection techniques for instant assembly of electronics on stretchable e-textile ribbons

This article addresses the research and development of a reliable interconnection technique for mounting surface mounted device components onto newly developed conductive stretchable textile ribbons. The alternative nonconductive adhesive bonding in which electrical contact is realized only by mechanical pressure and fixed by an adhesive and the conventional soldering technique were selected for examination. Assessment of the performance of these techniques and their usability for interconnecting components on conductive textile ribbons was also our research goal. Reliability tests of the electrical and mechanical properties of realized interconnections (dry heat, damp heat, washing, electrical current load, jerk, and stretch tests) were realized. The results show that the nonconductive adhesive technique results in good mechanical properties and acceptable median electrical resistance of less than 2 Ω even after 90 washing cycles. It is also very gentle and fully compatible with textile production due to the maximal processing temperature lower than 70°C, without the risk of short circuit occurrence. This technique is suitable for sensors, illumination or data transfer applications. While soldering results in excellent median electrical resistance of less than 20 mΩ, it is more complex and costly. Moreover, there is a risk of short circuits as well as of textile damage by the high thermal load over 150°C. Soldering is more suitable for power supply applications or heating. The above-mentioned results were also confirmed in a decision analysis with pairwise comparisons, involving company representatives considering introducing the above-mentioned interconnection techniques into their production. The nonconductive adhesive technique was evaluated as 15% better in overall decision analysis than the low-temperature soldering.

Superior Labrum Anterior Posterior Clinical Exam Techniques

Background: Superior labrum anterior posterior (SLAP) lesions are prevalent in athletes and the elderly. Therefore, acquiring accurate diagnoses is beneficial for improvement in return to play for athletes and quality of life. A well-done clinical examination can help detect these lesions leading to an early and accurate diagnosis. Indications: Being able to perform a clinical examination for diagnosing SLAP lesions is an important tool for a doctor to know. Currently, there is not a centralized location with published videos that show how to perform these examinations and describe their attributes. This video helps clinicians quickly ascertain how to perform these examinations and learn about the statistical measures associated with them. Technique Description: The 7 exams shown are as follows: modified dynamic labral shear (DLS) test, speed’s test, active compression test (O’Brien test), anterior slide test, crank test, Kim test, and the Jerk test. Results: These tests have a wide variety of statistical measures making different ones useful for specific results such as ruling in or ruling out labral lesions. The tests with the highest sensitivity are the modified dynamic labral shear test (72%) and Kim test (61%-92%). The tests with the highest specificity are the modified dynamic labral shear test (98%), anterior slide test (81%-89%), Kim test (88%-99%), and the Jerk test (94%-99%). All of these have a 95% confidence interval except DLS test. Discussion/Conclusions: Some of these tests are more reliable than others when diagnosing labral lesions. Since the dynamic labral shear test and Kim test have the highest sensitivity, they are the most useful tests at ruling out labral lesions. These tests along with the anterior slide test and the Jerk test are the most useful for ruling in labral lesions due to their high specificity. Even though these tests have been proven to be more reliable than others, it still matters which tests the doctors feel comfortable performing accurately for them to use in the clinical setting.

Shoulder ranges of motion and humeral torsions of injured baseball players have different characteristics depending on their pitching sides.

BackgroundRight- and left-side throwers in baseball may have different shoulder conditions and throwing biomechanics. This study aimed to compare the passive range of motion, humeral torsion, and clinical findings between right- and left-handed throwers who sustained throwing shoulder injuries and confirm the differences in the characteristics between throwing sides.MethodsA total of 52 pitchers diagnosed with throwing shoulder injuries were included in this study: 27 patients were right-side throwers (R group), and 25 were left-side throwers (L group). We measured the bilateral passive external and internal rotation angles in abduction position (ABIR) and total arc at their first visit. To assess posterior shoulder tightness, the internal rotation angles in forward flexion (FIR), and the abduction angle (AA) and horizontal flexion angle (HFA) without scapula motion were measured. The bilateral humeral torsion angles were also measured using ultrasonography. These values were compared between the participants' throwing and non-throwing sides and between the R and L groups' throwing sides. Furthermore, several physical findings in the shoulders were assessed, and the positive ratio was compared between the R and L groups.ResultsOn comparing the throwing and non-throwing sides, the R group had significantly greater external rotation angles in the abduction position and humeral torsion angle, and smaller ABIR, total arc, FIR, AA, and HFA in the throwing side, while the L group showed no significant differences, except for a smaller ABIR and larger HFA in the throwing side. On comparing the throwing side between the R and L groups, the R group had a smaller FIR, AA, and FHA than the L group. Regarding the physical findings, the posterior jerk test, Kim test, anterior and posterior drawer sign, sulcus sign, and scapular winging in the L group were significantly more positive than in the R group.ConclusionThe range of motion and humeral torsions differed between the left- and right-side throwers, as did the pathology between their throwing sides. Clinicians should consider the possibility that the pathological condition differs between left- and right-side throwers.

Clinical Characteristics and Surgical Outcomes for Collision Athletes with Traumatic Posterior Instability.

Diagnosis and treatment of traumatic posterior instability of the shoulder have not been described in detail. The author investigated surgical outcomes for traumatic posterior shoulder joint instability in collision athletes. The author surgically treated patients with a diagnosis of traumatic shoulder joint instability and investigated those that had been followed up for >2 years after surgery. Seven shoulders in six collision athletes with a history of traumatic injury were examined. All cases were negative for the general laxity sign and positive for the posterior jerk test; five shoulders showed positive anterior apprehension. Posterior glenoid osseous defects were found in three shoulders, and one shoulder injury involved anterior and posterior osseous lesions. As surgical treatment, one posterior capsulolabral lesion, two posterior osseous lesions, and three combined anterior and posterior capsulolabral lesions were repaired arthroscopically. In a patient with a combined anterior and posterior osseous lesion, the Bristow procedure was perfromed after arthroscopic osseous repair. Patients returned to competition at an average of 6.8 months after surgery. One patient developed anterior subluxation at 7 months, and another exhibited posterior re-dislocation at 8 months after returning to competition. Traumatic posterior instability in collision athletes often involves glenoid osseous lesions and is frequently accompanied by anterior apprehension and lesions. Although collision athletes can return to play after arthroscopic repair, such activity is associated with a risk of re-dislocation.

Posterior Open-wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-free, J-shaped Iliac Crest Bone Graft in Atraumatic Posterior Instability with Pathologic Glenoid Retroversion and Dysplasia: A Preliminary Report.

Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery. In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up? Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid. All seven patients had a follow-up examination at a minimum of 2 years. The median (range) age at surgery was 27 years (16 to 45) and the median follow-up was 2.3 years (2 to 3). Apprehension was assessed by a positive posterior apprehension and/or posterior jerk test. Patient-reported shoulder scores were obtained and included the subjective shoulder value, obtained by chart review (and scored with 100% representing a normal shoulder; minimum clinically important difference [MCID] 12%), and the Constant pain scale score (with 15 points representing no pain; MCID 1.5 points). Radiographic measurements included glenohumeral arthropathy and posterior humeral head subluxation, bone graft union, correction of glenoid retroversion and glenoid concavity depth, as well as augmentation of glenoid surface area. All endpoints were assessed by individuals not involved in patient care. In four of seven patients, posterior apprehension was positive, but none reported resubluxation. The preoperative subjective shoulder value (median [range] 40% [30% to 80%]) and Constant pain scale score (median 7 points [3 to 13]) were improved at latest follow-up (median subjective shoulder value 90% [70% to 100%]; p = 0.02; median Constant pain scale score 15 points [10 to 15]; p = 0.03). Posterior glenoid cartilage erosion was present in four patients (all four had Walch Type B1 glenoids) preoperatively and showed no progression until the final follow-up examination. The median (range) humeral head subluxation index decreased from 69% (54% to 85%) preoperatively to 55% (46% to 67%) postoperatively (p = 0.02), and in two of four patients with preoperative humeral head subluxation (> 65% subluxation), it was reversed to a centered humeral head. CT images showed union in all implant-free, J-shaped iliac crest bone grafts. The median preoperative retroversion was corrected from 16° (15° to 25°) to 0° postoperatively (-5° to 6°; p = 0.02), the median glenoid concavity depth was reconstructed from 0.3 mm (-0.7 to 1.6) preoperatively to 1.2 mm (1.1 to 3.1) postoperatively (p = 0.02), and the median preoperative glenoid surface area was increased by 20% (p = 0.02). No intraoperative or postoperative complications were recorded, and no reoperation was performed or is planned. In this small, retrospective series of patients treated by experienced shoulder surgeons, a posterior J-bone graft procedure was able to reconstruct posterior glenoid morphology, correct glenoid retroversion, and improve posterior shoulder instability associated with pathologic glenoid retroversion and dysplasia, although four of seven patients had persistent posterior apprehension. Although no patients in this small series experienced complications, the size and complexity of this procedure make it likely that as more patients have it, some will develop complications; future studies will need to characterize the frequency and severity of those complications, and we recommend that this procedure be done only by experienced shoulder surgeons. The early results in these seven patients justify further study of this procedure for the proposed indication, but longer term follow-up is necessary to continue to assess whether it is advantageous to combine the reconstruction of posterior glenoid concavity with correction of pathological glenoid retroversion and increasing glenoid surface compared with traditional surgical techniques such as the posterior opening wedge osteotomy or simple posterior bone block procedures. Level IV, therapeutic study.

Posterior Humeral Avulsion of the Glenohumeral Ligament: A Rare and Nonspecific Injury

Posterior Humeral Avulsion of the Glenohumeral Ligament: A Rare and Nonspecific Injury

Effect of Posterior Glenoid Bone Loss and Retroversion on Arthroscopic Posterior Glenohumeral Stabilization

Background: Posterior glenohumeral instability is an increasingly recognized cause of shoulder instability, but little is known about the incidence or effect of posterior glenoid bone loss. Purpose: To determine the incidence, characteristics, and failure rate of posterior glenoid deficiency in shoulders undergoing isolated arthroscopic posterior shoulder stabilization. Study Design: Cohort study; Level of evidence, 3. Methods: All patients undergoing isolated posterior labral repair and glenoid-based capsulorrhaphy with suture anchors between 2008 and 2016 at a single institution were identified. Posterior bone deficiency was calculated per the best-fit circle method along the inferior two-thirds of the glenoid by 2 independent observers. Patients were divided into 2 groups: minimal (0%-13.5%) and moderate (>13.5%) posterior bone loss. The primary outcome was reoperation for any reason. The secondary outcomes were military separation and placement on permanent restricted duty attributed to the operative shoulder. Results: A total of 66 shoulders met the inclusion criteria, with 10 going on to reoperation after a median follow-up of 16 months (range, 14-144 months). Of the total shoulders, 86% (57/66) had ≤13.5% bone loss and 14% (9/66) had >13.5%. Patients with moderate posterior glenoid bone loss had significantly greater retroversion (−11.5° vs −4.3°; P = .01). Clinical failure requiring reoperation was seen in 10.5% of patients in the minimal bone deficiency group and 44.4% in the moderate group (P = .024). There was no difference between groups in rate of military separation or restricted duty. Patients with moderate posterior glenoid bone deficiency were more likely to be experiencing instability instead of pain on initial presentation (P < .001), were more likely to have a positive Jerk test result (P = .05), and had increased glenoid retroversion (P = .01). Conclusion: In shoulders with moderate glenoid bone deficiency (>13.5%) and increased glenoid retroversion, posterior capsulolabral repair alone may result in higher reoperation rates than in shoulders without bone deficiency.

Posterior Glenohumeral Instability: Diagnosis and Management

Posterior glenohumeral instability can manifest as posterior shoulder pain and dysfunction, particularly among athletes. Repetitive, posteriorly-directed axial loads, as commonly encountered by contact athletes (American football linemen, rugby players), result in microtrauma that can induce posteroinferior labral tears. Alternatively, SLAP tears commonly seen in throwing athletes may propagate in a posteroinferior direction (i.e., a type VIII SLAP tear), owing to a complex pathologic cascade involving glenohumeral capsular contracture and imbalances among the dynamic stabilizing muscles of both the glenohumeral joint and shoulder girdle. The diagnosis of posterior glenohumeral instability is elucidated by a thorough history and physical examination. Posterior shoulder pain is oftentimes insidious in onset. The throwing athlete with posterior glenohumeral instability may complain of diminished control, accuracy, and generalized shoulder discomfort. A number of provocative physical examination maneuvers have been described (Kim test, Jerk test), which load the humeral head against the labral lesion and recreate patients’ symptoms. Magnetic resonance imaging and magnetic resonance arthrography can be of value in demonstrating avulsions of the labrum from the posteroinferior glenoid, and computed tomography is useful for quantifying the location and amount of attritional glenoid bone loss, although in contradistinction to anterior glenohumeral instability, clearly defined thresholds that would otherwise guide treatment have not been established. In the absence of substantial bone loss, arthroscopic posterior capsulolabral repair remains the gold standard for the surgical management of symptoms refractory to nonoperative treatment, and excellent clinical outcomes have generally been reported. However, high rates of return to play at the previous level of participation, particularly among throwing athletes, have been less consistently observed. Risk factors for the need for revision stabilization include surgery on the dominant extremity, female sex, and capsulolabral repairs involving either anchorless techniques or the use of less than 4 anchors.

Evidence-Based Review of Clinical Diagnostic Tests and Predictive Clinical Tests That Evaluate Response to Conservative Rehabilitation for Posterior Glenohumeral Instability: A Systematic Review

Context:Posterior glenohumeral instability is poorly understood and can be challenging to recognize and evaluate. Using evidence-based clinical and predictive tests can assist clinicians in appropriate assessment and management.Objective:To review evidence-based clinical diagnostic tests for posterior glenohumeral instability and predictive tests that identify responders to conservative management.Data Sources:A comprehensive electronic bibliographic search was conducted using Embase, Ovid MEDLINE, PEDro, and CINAHL databases from their date of inception to February 2017.Study Selection:Studies were included for further review if they (1) reported on clinical diagnostic tests for posterior or posteroinferior instability of the glenohumeral joint, (2) assessed predictive clinical tests for posterior instability of the glenohumeral joint, and (3) were in English.Study Design:Systematic review.Level of Evidence:Level 4.Data Extraction:Data were extracted from the studies by 2 independent reviewers and included patient demographics and characteristics, index/reference test details (name and description of test), findings, and data available to calculate psychometric properties.Results:Five diagnostic and 2 predictive studies were selected for review. There was weak evidence for the use of the jerk test, Kim test, posterior impingement sign, and O’Brien test as stand-alone clinical tests for identifying posterior instability. Additionally, there was weak evidence to support the use of the painless jerk test and the hand squeeze sign as predictive tests for responders to conservative management. These findings are attributed to study design limitations, including small and/or nonrepresentative samples.Conclusion:Clustering of thorough history and physical examination findings, including the aforementioned tests, may identify those with posterior glenohumeral instability and assist in developing management strategies.

Arthroscopic Surgery for Posterior Shoulder Instability in Throwing Athletes

As for treatment of posterior shoulder instability in throwing athletes, careful management is necessary because of high recurrence. As we know, Posterior shoulder instability is uncommon. Because of the difficulty in establishing a diagnosis and an instability classification system, accurate diagnosis and successful treatment remain challenging. Especially in thrower’s dominant arm, complete return to sports activity needs enough stabilization and range of motion.In this study, our objective is to evaluate the clinical results of arthroscopic surgery for posterior shoulder instability in thrower’s dominant arm. From 2007 to 2013, we treated 20 cases in throwing athletes. Among them, we investigate 18 cases which is follow-up period more than 2 years. 18 cases were consist of 16 male and 2 female. Average Age at operation was 23.2 years old. Their sports was Baseball player were 14 and Softball player was 4 case. Their position were 9 cases were Pitchers, 9 cases were field players. Their performance level was professional player were 3, college player were 7, high-school player were 4, recreation level were 4 cases. Preoperative Jerk test was positive in all case. As for our operative procedure, if there was no labrum tear, capsular plication with sutures only was selected. If Labrum tear was exists, capsule-labral sutures with anchors was selected and if remain patulous capsule, interval plication sutures was added.Postoperative 5 months shadow pitching and throwing was started. Return to the game was permitted Postoperative 8 months.Clinical outcome was evaluated according to the Japanese shoulder society shoulder instability score and Post-op. Recurrence, apprehension sign, ROM, Complication, Return to sports activity. The average postoperative JSS-Shoulder instability score improved from 61.3 to 87.5 points at postoperative 1year, but score was decrease 84.5 points at preoperative 2 years, 82.4 points at final follow up. Posterior jerk was 1 case (7%) at postoperative 1year, but increase to 32% at final follow up. Similarly, Posterior apprehension was 1 case (7%) at postoperative 1year, but increase to 38% at final follow up. Post-op. pain and complication was none but 3cases had limited of range of motion. As for return to sports participation, return rate was 78% at postoperative 1year, but 58% at final follow up. In our case, poor cases as for Return to sports were 7 cases (38%). The cause of poor results were pitchers and Post-op. Limited range of motion which not reach to preoperative level or not strongly swung in game. Another cause of poor results were considered trauma history, too looseness which was positive of bilateral. Post jerk test and Sulcus sign and capsular plication with sutures. In severe looseness shoulder, there was no indication of arthroscopic surgery. Clinical results of Arthroscopic surgery for posterior shoulder instability in throwing athletes was evaluated. Recurrent ratio at final follow up was 32%. Return to sports participation was 78% at postoperative 1 year, but 58% at final follow up. As for treatment of posterior shoulder instability in throwing athletes, careful management is necessary because of high recurrence.

Soft tissue-based surgical techniques for treatment of posterior shoulder instability.

Posterior shoulder instability is a rare clinical condition that encompasses different degrees of severity including various possible pathologies involving the labrum, capsule, bony lesions, and even locked posterior dislocation. When focusing on soft tissue involvement, the diagnosis of posterior instability may be difficult to make because frequently patients report vague symptoms not associated with a clear history of traumatic shoulder dislocation. Pathological soft tissue conditions associated with posterior instability in most cases are related to posterior labral tear and/or posterior capsular detensioning/tear. The diagnosis can be facilitated by physical examination using specific clinical tests (i. e., jerk test, Kim test, and reinterpreted O’Brien test) together with appropriate imaging studies (i. e., magnetic resonance arthrography). Arthroscopy may help in a complete evaluation of the joint and allows for the treatment of soft tissue lesions in posterior instability. Caution is warranted in the case of concomitant posterior glenoid chondral defect as a potential cause of poor outcome after soft tissue repair in posterior instability.

Arthroscopic transphyseal anterior cruciate ligament reconstruction in adolescent athletes.

To evaluate the 5-year outcome of arthroscopic transphyseal anterior cruciate ligament (ACL) reconstruction in 19 adolescent athletes. 14 male and 5 female adolescent athletes aged 12 to 16 (mean, 13.9) years with Tanner stage 2 or 3 open physes underwent arthroscopic transphyseal ACL reconstruction by a single surgeon and were followed up for 5 years. Patients were evaluated using the numerical rating score (NRS) for pain, knee osteoarthritis outcome score (KOOS), International Knee Documentation Committee (IKDC) score, Tegner Activity Scale, and Lysholm Score, as well as the leg length discrepancy, femorotibial alignment, varus or valgus deformities, active and passive knee range of motion. At 5-year follow-up, physes were closed in all patients. The mean NRS for pain improved from 7.2 to 1.6; the KOOS improved from 55.3 to 88; the mean IKDC score improved from 34.5 to 84; the mean Tegner Activity Scale improved from 2.7 to 8.2 and was comparable with that before injury (8.4); and the mean Lysholm score improved from 36.3 to 84.6. All except 2 patients returned to their pre-injury level of sports activity after a mean of 25 weeks. The 2 exceptions had a 2+ Jerk test and a 3+ Lachman test; one of them also had positive signs for a lateral meniscal lesion. Both had sustained a second trauma not long before the 5-year follow-up. Two patients had reduced sensitivity in the anteromedial aspect of the proximal third of the tibia. One patient had leg length discrepancy of +1.5 cm owing to overgrowth response of the physis. Transphyseal ACL reconstruction is a viable option for skeletally immature patients, with high reproducibility, a high rate of return to sport, and a low incidence of growth disturbance. Early surgery can prevent the onset of meniscal lesions and early osteoarthritis.

Relationship between Widening and Position of the Tunnels and Clinical Results of Anterior Cruciate Ligament Reconstruction to Knee Osteoarthritis: 30 Patients at a Minimum Follow-Up of 10 Years

To evaluate the relationship between tunnel position and widening and long-term clinical results in anterior cruciate ligament (ACL) reconstruction, a retrospective cohort of 30 patients undergoing ACL reconstruction with double semitendinous plus double gracilis (SAC technique) with longer than 10-year follow-up was selected. CT scans in the first 3 months and at final follow-up was evaluated. Position, angle, and widening of tunnels including Nebelung criteria were recorded in all CT scans. Physical, KT-1000, and clinical evaluation were performed at final follow-up. Outcomes and knee arthritis severity were evaluated at final follow-up. Mean follow-up was 11.2 ± 1.2. At final follow-up, 85 and 57% of tibial and femoral tunnels, respectively, developed some degree of enlargement. Frontal tibial angle (mean) was 72°, sagittal tibial angle 63°, frontal femoral angle 47°, sagittal femoral angle 20°, and tunnels divergence angle 36°. Preoperatively, KT-1000 30L and Lachman test scores were 5.52 and 5.79 respectively. In the last follow-up, 30L and manual Lachman test scores were 0.97 and 1.13, respectively (p < 0.001). In IKDC scale, pivot shift and Jerk tests showed 83 and 84% grade A results, respectively (p < 0.0001). In Fairbank scale, 23% worsened one grade and 27% worsened more than one grade (p < 0.005). Tibial tunnels widened more than femoral tunnels and further dilatation was found between intermediate and final follow-up. Higher incidence of tibial tunnel widening was observed in patients with tunnel verticalization. Tibial tunnel dilation was associated with long-term degenerative changes but not with final knee instability.

LCA opéré et retour sur le terrain

To authorize the return to sports after LCA surgery is a decision difficult to take. Repeated accidents vary from 5 to 32%, with more risk on the healthy knee. We made a review of the literature centred on the risk of re-rupture of the LCA to propose a series of tests to guide the physician in its decision to authorize or not the return to sport. We propose a sequence associating clinical tests (swelling, range of motion, comparative laximetry, jerk test), physiologic tests (single or multiple hop jump tests with and without rebound) and psychological (ACL-RSI Scale).

Diagnostic value of the clinical investigation in acute meniscal tears combined with anterior cruciate ligament injury using arthroscopic findings as golden standard.

The main purpose of our study was to evaluate the accuracy of clinical investigation for meniscal tears associated with ACL injuries. We hypothesized that combined ACL injury can decrease the accuracy of clinical examination in acute onset. One hundred and thirty-seven patients with a mean age of 28.5 years (from 12 to 55) were prospectively examined for acute combined ACL and meniscal injuries, between March and November 2012 at our department. For meniscal tears, clinical examination was performed using McMurray test, Apley test and medial and lateral joint line tenderness. The diagnoses of ACL tear were made using Lachman test, jerk test and pivot-shift test, anterior drawer test and KT-2000 side-to-side difference. Each patient was examined using X-ray and MRI. All the patients underwent arthroscopic surgery performed by the same surgeon within 6 weeks after the injury. Finally, using the arthroscopic findings as gold standard, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of clinical investigation and MRI were evaluated. The specificity of clinical investigation was 63.5 and 46.0 % and the sensitivity was 74.4 and 77.3 % for the medial meniscus and the lateral meniscus, respectively. Overall, the accuracy of the clinical investigation was 70.3 % for the MM and 65.5 % for the lateral meniscus. The accuracy of MRI investigation was 76.4 and 69.5 % for medial and lateral meniscus, respectively. In combined acute ACL injury and meniscal tears, we have found a decreased accuracy of the clinical investigation. The remnants of the torn ACL and the synovitis increased the rate of false positives, and it could simulate meniscal tears. However, clinical investigation can provide sufficient information for the treatment decision and MRI can be avoided as a routine diagnostic tool. Level II, prospective study.

Biomechanical Characteristics of 3 Pivot-Shift Maneuvers for the Anterior Cruciate Ligament–Deficient Knee

Background: A disadvantage of pivot-shift maneuvers is that the examiner has to subjectively evaluate the degree of pivot shift observed. It is unknown whether the various maneuvers are biomechanically identical. Purpose: To compare biomechanical features of 3 clinical maneuvers for the anterior cruciate ligament (ACL)–deficient knee: the pivot-shift test, the jerk test, and the N-test. Study Design: Controlled laboratory study. Methods: A total of 28 patients with an isolated ACL injury were examined by use of 3 pivot-shift maneuvers (pivot-shift test, jerk test, and N-test). An electromagnetic sensor system was used to evaluate the 3-dimensional knee kinematics of each patient’s injured and uninjured knees during each maneuver. Peak coupled anterior tibial translation (pCAT) and maximal acceleration of posterior translation (APT) were measured relative to results during a flexion-extension motion in each test. Results: The pCAT of the pivot-shift test was significantly greater than that of both the jerk test and the N-test (P = .0020 and P < .0001, respectively); there was no statistical difference in pCAT between the jerk test and the N-test. The APT of the N-test was significantly greater than that of both the pivot-shift test and the jerk test (P < .0001), while there was no statistical difference between the pivot-shift and the jerk tests. There was no correlation between pCAT and APT in each test. Conclusion: The pivot-shift test, jerk test, and N-test have different biomechanical characteristics to induce the pivot-shift phenomenon in the ACL-deficient knee. The pivot-shift test produced the largest side-to-side difference in pCAT, whereas the N-test provoked the largest side-to-side difference in APT. Clinical Relevance: The biomechanical differences in pivot-shift maneuvers are caused by technical differences, and clinicians should understand these biomechanical differences while practicing the maneuvers. The electromagnetic sensor system is clinically useful for quantifying the pivot-shift phenomenon.

Paper 25: Painful Jerk Test: A Predictor of Success in Nonoperative Treatment of Posteroinferior Instability of the Shoulder

Paper 25: Painful Jerk Test: A Predictor of Success in Nonoperative Treatment of Posteroinferior Instability of the Shoulder

Development of a wire rope model for cable guardrail simulation

Cable guardrail systems have received increased attention due to their low installation cost and excellent safety performance. This has led to an increase in the use of non-linear finite element modelling for the design and analysis of such systems. However, wire rope models previously used were not validated with physical testing. Thus, an improved non-linear finite element analysis model of 19-mm diameter 3 × 7 wire rope commonly used in roadside cable guardrail installations was developed. Component tests were conducted on wire rope, and consisted of quasi-static tension and cantilever bending tests, high-speed jerk tests of wire rope constrained at one end and perpendicular impacts of wire rope constrained at both ends. Simulation of these tests indicated favourable comparison of bogie vehicle motion and wire rope tension with test results, and was significantly more accurate than previously developed models. Application of the new wire rope model to a full-scale impact on a cable guardrail system indicated good comparison of the new wire rope model with the wire rope reactions in the full-scale test.

Investigation to predict patellar tendon reflex using motion analysis technique

The investigation of patellar tendon reflex involves development of a reflex hammer holder, kinematic data collection and analysis of patellar reflex responses using motion analysis techniques. The main aim of this research is to explore alternative means of assessing reflexes as a part of routine clinical diagnosis. The motion analysis system was applied to provide quantitative data which is a more objective measure of the patellar tendon reflex. Kinematic data was collected from 28 males and 22 females whilst subjected to a knee jerk test. Further analysis of kinematic data was performed to predict relationships which might affect the patellar tendon reflex. All subjects were seated on a high stool with their legs hanging freely within the capture volume of the motion analysis system. Knee jerk tests were applied to all subjects, on both sides of the leg, by eliciting hypo, hyper, and normal reflexes. An additional reinforcement technique called the Jendrassik manoeuvre was also performed under the same conditions to elicit a normal patellar tendon reflex. The comparison of reflex response between genders showed that female subjects generally had a greater response compared to males. However, the difference in reflex response between the left leg and the right leg was not significant. Tapping strength to elicit a hyper-reflex produced greater knee-jerk compared to the normal clinical tapping strength. All results were in agreement with clinical findings and results found by some early researchers.