High knee valgus in female subjects does not yield higher knee translations during drop landings: a biplane fluoroscopic study

The goal of this study was to determine the effects of peak knee valgus angle and peak knee abductor moment on the anterior, medial, and lateral tibial translations (ATT, MTT, LTT) in the "at risk" female knee during drop landing. Fifteen female subjects performed drop landings from 40 cm. Three-dimension knee motion was simultaneously recorded using a high speed, biplane fluoroscopy system, and a video-based motion analysis system. Valgus knee angles and knee abduction moments were stratified into low, intermediate, and high groups and peak ATT, MTT, and LTT were compared between these groups with ANOVA (α = 0.05). Significant differences were observed between stratified groups in peak knee valgus angle (p < 0.0001) and peak knee abduction moment (p < 0.0001). However, no corresponding differences in peak ATT, LTT, and MTT between groups exhibiting low to high-peak knee valgus angles (ATT: p = 0.80; LTT: p = 0.25; MTT: p = 0.72); or, in peak ATT (p = 0.61), LTT (p = 0.26) and MTT (p = 0.96) translations when stratified according to low to high knee abduction moments, were found. We conclude that the healthy female knee is tightly regulated with regard to translations even when motion analysis derived knee valgus angles and abduction moments are high.

The role of TNXB single-nucleotide polymorphisms in recurrent shoulder dislocation

Tenascin-X (TNX) is an extra-cellular matrix glycoprotein associated with collagen fibril deposition. Recent reports have linked truncated TNX mutations (TNXB) to generalized joint hypermobility and most importantly recurrent joint dislocation. In the present study, we investigated whether there is an association between joint dislocation recurrence rate and the frequency of TNXB single-nucleotide polymorphisms (SNPs). Seventy-eight patients treated for post-traumatic shoulder instability and 82 healthy controls were genotyped for selected TNXB SNP using TaqMan® Genotyping Assays. At a mean follow-up of 24 months recurrence rate and clinical outcomes were evaluated using the Constant and Murley, Rowe, and DASH scores. The association between genotypes and joint dislocation was tested using the dominant, recessive and additive models, and the model-free approach. Genotype distribution of the examined SNPs did not significantly deviate from the Hardy-Weinberg equilibrium (HWE) neither in patients nor in the controls. Moreover, there was no significant difference in genotype and allele distribution between patients and controls. Finally, no difference in genotype frequency was detected between patients who experienced a re-dislocation after the initial surgery and patients who did not sustain a re-dislocation. The SNPs investigated in this study have no clinically relevant influence on TNXB gene expression and/or TNX function. Therefore, these SNPs could not be used for predicting individual risk of recurrent shoulder dislocation.

Palpation tests versus impingement tests in Neer stage I and II subacromial impingement syndrome

PURPOSE

Using sonographic findings to test the diagnostic accuracy of impingement versus tendon palpation tests in Neer stage I and II subacromial impingement syndrome cases and examine their clinical potential.

METHODS

Neer and Hawkins impingement tests and rotator cuff tendon palpation tests followed by bilateral shoulder sonography were conducted on 69 patients with a clinical diagnosis of unilateral subacromial impingement.

RESULTS

The Neer and Hawkins tests had 74 and 62 % accuracy (sensitivity 80 and 67 %, and specificity 52 and 47 %, respectively) in comparison to 79 and 62 % accuracy rates for supraspinatus and biceps tendon palpation tests (sensitivity 92 and 41 %, and specificity 41 and 48 %, respectively). Overall, the palpation tests scored better than impingement tests in the diagnosis of Neer stage I and II subacromial impingement syndrome. No tendinosis or tear was noted in patients with negative findings in the supraspinatus palpation tests (sensitivity 100 %, specificity 21 %).

CONCLUSION

Palpation tests for supraspinatus and biceps tendons have a slightly higher accuracy than the impingement tests, and if tenderness does not exist then supraspinatus tendinopathy can be ruled out. These findings warrant the use of palpation tests in a routine physical examination for tendinopathy.

LEVEL OF EVIDENCE

I.

Fracture-dislocations of the proximal interphalangeal joint

Fracture-dislocations of the proximal interphalangeal joint encompass a spectrum of injury severity, ranging from injuries that require little intervention to those that require advanced reconstructive surgery for optimal outcome. Three fracture-dislocation patterns are recognized: dorsal, volar, and pilon. Acceptable outcome is dependent on achieving and maintaining a well-aligned and well-reduced joint, re-establishing normal joint kinematics, and restoring motion. Anatomic articular surface reduction is desirable but not absolutely necessary for a good outcome. Treatment depends on both the type of injury and patient-dependent factors. Optimal outcome for a specific injury is predicated on expedient diagnosis and recognition of injury severity, which enables initiation of appropriate management.

Relationship between the extent of labral lesions and the frequency of glenohumeral dislocation in shoulder instability

PURPOSE

This study aimed to evaluate the relationship between the extent of the labral lesion and the frequency of glenohumeral dislocation in patients with shoulder instability.

METHODS

Ninety-three patients, who underwent surgical treatment at our clinic for chronic anterior shoulder dislocation, were selected and divided into 3 groups (group I: only Bankart lesion; group II: Bankart and SLAP lesions; group III: circumferential-labral lesion). The pre-operative frequency of dislocation, intraoperative findings, operation time, post-operative clinical score, and range of motion 2 years after surgery were analysed and compared among the 3 groups.

RESULTS

The time interval from the initial dislocation to operation was significantly shorter in group III than in groups I and II (P = 0.034 and P = 0.046, respectively). The median number of preoperative dislocations was also significantly less in group III than in groups I and II (P = 0.025 and P = 0.044, respectively). In all groups, the clinical scores (Constant, Rowe, and visual analogue scale) improved significantly post-operatively, and there were no significant differences in the scores between the different groups. All patients returned to work, and most patients returned to their preoperative sports activity levels.

CONCLUSION

The extent of the labral lesion is not always related to the number of dislocations; therefore, treatment should not be based on this.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Second-look arthroscopic findings after open-wedge high tibia osteotomy focusing on the posterior root tears of the medial meniscus

PURPOSE

This study examined, at second-look arthroscopy, the results of open-wedge high tibial osteotomy (HTO) focusing on root tear of the medial meniscus posterior horn (RTMMP).

METHODS

Among 31 consecutive patients who underwent HTO without a meniscectomy or pullout repair for RTMMP, 20 patients were available for second-look arthroscopic evaluation. All patients had medial unicompartmental arthritis. The healing status of the RTMMP was classified as complete, incomplete, and no healing. The difference in the weight bearing line from presurgery to the last follow-up was evaluated. Osteoarthritis and chondral lesions were evaluated, as were clinical results. Correlations between healing status and other variables (weight bearing line, cartilage status, and clinical scores) were assessed. The healed (10 patients) and nonhealed (incomplete 6 patients + no healing 4 patients) groups were also evaluated with respect to other variables.

RESULTS

There were 10 (50%) cases with complete healing, 6 (30%) with incomplete healing, and 4 (20%) with no healing. Kellgren-Lawrence grade did not improve according to the standing plain radiograph (P = .09). Progression of chondral lesions was not observed at second-look arthroscopy; some improvement was even observed (P = .002). The median Lysholm score improved from 58 preoperatively to 88.5 at the last follow-up. The median Hospital for Special Surgery (HSS) score also increased significantly from 62.4 (range, 50 to 76) to 87.2 (range, 80 to 92; P = .003). The comparison between healed and nonhealed groups revealed no statistical differences in all variables.

CONCLUSIONS

This study revealed a high rate of healing of RTMMP after HTO without attempted repair. Healing of the meniscus was not associated with an improved clinical outcome.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Allograft salvage procedure in multiple-revision anterior cruciate ligament reconstruction

BACKGROUND

Multiple-revision anterior cruciate ligament (ACL) reconstructions represent a surgical challenge due to the presence of previous tunnels, hardware, injuries to the secondary stabilizers, and difficulties in retrieving autologous tendons. An anatomic ACL reconstruction may therefore result in a demanding surgery, thus requiring 2 stages.

PURPOSE

To analyze the efficacy of an over-the-top ACL reconstruction technique plus extra-articular plasty using Achilles or tibialis posterior tendon allograft in restoring knee stability in patients with at least 2 failed previous ACL reconstructions, as well as to evaluate the factors able to affect the final outcome.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From 2002 to 2008, 24 male athletes with a mean age of 30.8 years underwent surgery. Twenty patients had undergone 2, whereas 4 patients had undergone 3 previous reconstructions. The International Knee Documentation Committee (IKDC) score and KT-2000 arthrometric evaluation were used to measure outcomes at a mean follow-up period of 3.3 years (range, 2-7).

RESULTS

The mean ± SD IKDC subjective score at follow-up was 81.3 ± 14.0. The IKDC objective score was an A or B in 20 patients (83%). Arthrometer side-to-side difference averaged 3.1 ± 1.1 mm. Range of motion was normal or nearly normal in 23 patients and abnormal in 1. Of the 20 good results, 17 patients resumed sports activity at the preinjury level.

CONCLUSION

A 2-stage revision is an accepted option in cases of excessive tunnel enlargement and bone loss, especially on the femoral side, to achieve anatomic reconstruction. Nonanatomic over-the-top ACL reconstruction and lateral extra-articular plasty technique allow one to overcome difficult anatomic situations on the femoral side, permitting a 1-step surgery. The overall results obtained in this series are comparable with those of other ACL revision series. The higher rate of mild instability observed in our series may not be attributable to the surgical technique but rather to the chronic instability suffered by these knees before last revision.

Diagnosis and prognosis of acute hamstring injuries in athletes

PURPOSE

Identification of the most relevant diagnostic and prognostic factors of physical examination and imaging of hamstring injuries in (elite) athletes.

METHODS

A literature search was conducted in MEDLINE and EMBASE for articles between 1950 and April 2011. A survey was distributed among the members of the European Society of Sports Traumatology, Knee Surgery and Arthroscopy, which focused on physical examination, prognosis, imaging and laboratory tests of hamstring injuries in (elite) athletes.

RESULTS

Medical history, inspection and palpation of the muscle bellies and imaging are most valuable at the initial assessment according to the literature. Experts considered medical history, posture and gait inspection, inspection and palpation of muscle bellies, range of motion tests, manual muscle testing, referred pain tests and imaging to be most important in the initial assessment of hamstring injuries. Magnetic resonance imaging (MRI) is preferred over ultrasonography and should take place within 3 days post-trauma. Important prognostic factors are injury grade, length of the muscle tear on MR images, MRI-negative injuries and trauma mechanism.

CONCLUSIONS

Posture and gait inspection, inspection and palpation of muscle bellies, range of motion tests, manual muscle testing and referred pain tests within 2 days post-trauma were identified as the most relevant diagnostic factors.

LEVEL OF EVIDENCE

Literature review and expert opinion, Level V.

Acute and late changes in intraarticular cytokine levels following anterior cruciate ligament injury

Surgical reconstruction of the anterior cruciate ligament (ACL) does not necessarily decrease the risk of developing osteoarthritis (OA). The inflammatory response and relative changes in pro- and anti-inflammatory cytokines could participate in triggering the development of OA. To test this hypothesis we measured the concentrations of IL-1β, IL-1ra, IL-6, IL-8, IL-10, and TNF-α at different times after ACL rupture. The sample population consisted of 48 patients with ACL tear which were assigned to different groups according to the time elapsed from the injury: 22 acute (A), 7 early sub-acute (ESA), 11 late sub-acute (LSA), and 8 chronic (C). In group A, there were high levels of IL-1β, IL-6, and IL-8, whereas levels of IL-1ra and TNF-α were significantly lower than usually reported. IL-1β and IL-8 concentrations returned with time to normal levels in the ESA group. Interestingly, IL-1ra levels remained always significantly lower than normally reported levels, and TNF-α levels did not increase after trauma. Our data show increased level of pro-inflammatory cytokines (IL-6 and IL-8) in the acute phase of inflammation which could be responsible for triggering cartilage catabolism and suggest that prompt neutralization of IL-6 and IL-8 accumulations in synovial fluid could help prevent development of OA in ACL-injured knees.

Feasibility of eight physical fitness tests in 1,050 older adults with intellectual disability: results of the healthy ageing with intellectual disabilities study

Although physical fitness is relevant for well-being and health, knowledge on the feasibility of instruments to measure physical fitness in older adults with intellectual disability (ID) is lacking. As part of the study Healthy Ageing with Intellectual Disabilities with 1,050 older clients with ID in three Dutch care services, the feasibility of 8 physical fitness tests was expressed in completion rates: box and block test, response time test, Berg balance scale, walking speed, grip strength, 30-s chair stand, 10-m incremental shuttle walking test, and the extended modified back saver sit and reach test. All tests had moderate to good feasibility in all subgroups, except for the participants with profound ID (all tests), severe ID (response time test and Berg balance scale), and wheelchair users (all tests that involve the legs). We conclude that the 8 tests are feasible to measure physical fitness in most older adults with ID.

MR imaging of anterior knee pain: a pictorial essay

Anterior knee pathology is a frequent cause of joint pain and limitation of function and mobility among patients presenting to an orthopaedic department. Proper recognition and treatment of pathologic conditions depend on the knowledge of normal anatomy and of the various abnormalities, which affect this area of the knee and may present with anterior knee pain. A broad array of benign and malignant processes may be manifested as anterior knee discomfort, and this common clinical entity is among the most frequent indications for MR imaging of the lower extremities. Clinical history and physical examination are also of paramount importance. The disorders can be categorized and differentiated primarily according to their location. Traumatic or non-traumatic disorders of the patella, patellar retinacula, quadriceps and patellar tendons and supra or infrapatellar fat pad can be the source of symptoms. This article includes a comprehensive pictorial essay of the characteristic MR features of common and uncommon disorders causing anterior knee pain. For accurate assessment of the aforementioned clinical problem, a radiologist should be able to identify typical MR imaging patterns that contribute in establishing the correct diagnosis and thus tailoring the appropriate therapy. Level of evidence IV.

Successful Fusion of the Proximal Tibiofibular Joint with Osteogenic Protein-1 (OP-1) Augmentation

Proximal tibiofibular joint (PTFJ) instability is rare, but when encountered can be difficult to manage. Previously reported forms of treatment, including cast immobilization, soft tissue repairs and reconstructions, and fibular head resection have met with limited success. Another option is PTFJ arthrodesis-however, fusion can be difficult and ankle pain after surgery is not uncommon. In this report, we present a novel surgical technique used to treat PTFJ instability. It is a form of PTFJ arthrodesis that utilizes the osteoinductive agent recombinant human osteogenic protein (rhOP-1) to help achieve fusion, in conjunction with a fibular osteotomy to unload the PTFJ and to preserve normal rotator mobility of the distal fibula during ankle motion. We have used this technique in two patients with successful results; one of whom required revision after two previous failed attempts at PTFJ fusion and the other who had a previous diagnosis of underlying collagen disorder. Their case studies are presented in detail in this report.

Associations between timing in the baseball pitch and shoulder kinetics, elbow kinetics, and ball speed

BACKGROUND

A baseball pitcher's ability to maximize ball speed while avoiding shoulder and elbow injuries is an important determinant of a successful career. Pitching injuries are attributed to microtrauma brought about by the repetitive stress of high-magnitude shoulder and elbow kinetics.

HYPOTHESIS

Over a number of pitches, variations in timing peak angular velocities of trunk segment rotations will be significantly associated with ball speed and upper extremity kinetic parameters.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Kinematic and kinetic data were derived from 9 to 15 fastball pitches performed by 16 active, healthy collegiate (n = 8) and professional (n = 8) pitchers via 3-dimensional motion capture (240 Hz). Each pitch was decomposed into 4 phases corresponding to the time between peak angular velocities of sequential body segment rotations. Four mixed models were used to evaluate which phases varied significantly in relation to ball speed, peak shoulder proximal force, peak shoulder internal rotation torque, and peak elbow varus torque. Mixed-model parameter coefficient estimates were used to quantify the influence of these variations in timing on ball speed and upper extremity kinetics.

RESULTS

All 4 mixed models were significant (P < .05). The time from stride-foot contact to peak pelvis angular velocity varied significantly in relation to all upper extremity kinetic parameters and ball speed. Increased time in this phase correlated with decreases in all parameters. Decreased ball speed also correlated with increased time between peak upper torso and elbow extension angular velocities. Decreased shoulder proximal force also correlated with increased time between peak pelvis and upper torso angular velocities.

CONCLUSION

There are specific phases that vary in relation to ball speed and upper extremity kinetic parameters, reinforcing the importance of effectively and consistently timing segmental interactions. For the specific interactions that varied significantly, increased phase times were associated with decreased kinetics and ball speed.

CLINICAL RELEVANCE

Although increased time within specific phases correlates with decreases in the magnitude of upper extremity kinetics linked to overuse injuries, it also correlates with decreased ball speed. Based on these findings, it may appear that minimizing the risk of injury (ie, decreased kinetics) and maximizing performance quality (ie, increased ball speed) are incompatible with one another. However, there may be an optimal balance in timing that is effective for satisfying both outcomes.

Joint Torques and Joint Reaction Forces During Squatting With a Forward or Backward Inclined Smith Machine

We developed a biomechanical model to determine the joint torques and loadings during squatting with a backward/forward-inclined Smith machine. The Smith squat allows a large variety of body positioning (trunk tilt, foot placement, combinations of joint angles) and easy control of weight distribution between forefoot and heel. These distinctive aspects of the exercise can be managed concurrently with the equipment inclination selected to unload specific joint structures while activating specific muscle groups. A backward (forward) equipment inclination decreases (increases) knee torque, and compressive tibiofemoral and patellofemoral forces, while enhances (depresses) hip and lumbosacral torques. For small knee flexion angles, the strain-force on the posterior cruciate ligament increases (decreases) with a backward (forward) equipment inclination, whereas for large knee flexion angles, this behavior is reversed. In the 0 to 60 degree range of knee flexion angles, loads on both cruciate ligaments may be simultaneously suppressed by a 30 degree backward equipment inclination and selecting, for each value of the knee angle, specific pairs of ankle and hip angles. The anterior cruciate ligament is safely maintained unloaded by squatting with backward equipment inclination and uniform/forward foot weight distribution. The conditions for the development of anterior cruciate ligament strain forces are clearly explained.

Acute and old ruptures of the extensor apparatus of the knee in adults (excluding knee replacement)

Rupture of the extensor apparatus of the knee in adults is infrequent and dominated by patellar fracture, which in our experience is six times as frequent as quadriceps or patellar tendon tear. Patellar fracture poses few diagnostic problems and treatment is now well codified. Tension-band osteosynthesis is generally used, involving two longitudinal K-wires and wire in a figure-of-eight pattern looped over the anterior patella; sometimes, for more complex fractures, cerclage wiring is added to the tension band. Non-union is rare and generally well tolerated. Quadriceps tendon tear mainly affects patients over 40 years of age, in a context of systemic disease. Diagnosis is easily suggested by inability to actively extend the knee, but is unfortunately still often overlooked in emergency. In most cases, early surgical management is needed to reinsert the tendon at the proximal pole of the patella by bone suture. For chronic lesions, it is often necessary to lengthen the quadriceps tendon by V-Y plasty or the Codivilla technique. Patellar tendon tear, on the other hand, typically occurs in patients under 40 years of age, often involved in sports. Diagnosis is again clinically straightforward, but again may be missed in emergency, especially in case of incomplete tear. Surgery is mandatory in all cases. The procedure depends on the type of lesion: either end-to-end suture or transosseous reinsertion. In most cases repair is protected by tendon augmentation. Old lesions often require tendon graft or a tendon-bone-tendon-bone graft taken from the opposite side.

Inter-segmental postural coordination measures differentiate athletes with ACL reconstruction from uninjured athletes

Athletes who sustain non-contact anterior cruciate ligament (ACL) injuries and undergo surgical reconstruction exhibit deficits in sensorimotor control, which often impairs lower-limb movement coordination. The purpose of this experiment was to measure the influence of sensorimotor deficits on the ankle-hip coordination of a postural coordination task in athletes following ACL reconstruction. Twenty-two female athletes who were cleared to return to sports participation following ACL reconstruction and 22 uninjured female athletes performed a unilateral dynamic postural rhythmic coordination task at two movement frequencies (0.2 and 0.7 Hz). Athletes with ACL-reconstruction exhibited greater ankle-hip relative phase variability and reduced regularity of coupling than uninjured athletes, especially during the 0.2 Hz condition. The results of this study show altered lower extremity coordination patterns in athletes following ACL reconstruction and return to sports participation. The results also indicate that dynamical coordination measures may provide objective measures of sensorimotor deficits following ACL reconstruction and can potentially guide rehabilitation interventions following reconstruction.

Accuracy of magnetic resonance imaging in grading knee chondral defects

PURPOSE

To determine the accuracy of routine magnetic resonance imaging (MRI) in the grading of knee cartilage lesions through a meta-analysis.

METHODS

A search of English-language literature published before February 2012 was carried out in PubMed. Articles using arthroscopy as a gold standard, a 6-knee region dividing method, and a 5-level grading system were included in our meta-analysis. After data extraction, a bivariate mixed-effects model and hierarchical weighted symmetric summary receiver operating curve were used to pool the results of diagnostic tests. A sensitivity analysis was conducted to explore the potential sources of heterogeneity.

RESULTS

Overall, 8 studies were included in the meta-analysis. The overall sensitivity, specificity, diagnostic odds ratio, positive likelihood ratio, and negative likelihood ratio were 75% (95% confidence interval [CI], 62% to 84%), 94% (95% CI, 89% to 97%), 47 (95% CI, 18 to 122), 12.5 (95% CI, 6.5 to 24.2), and 0.27 (95% CI, 0.17 to 0.42), respectively. There was substantial heterogeneity among the results. Sensitivity analysis showed the inconsistency of 2 studies. However, eliminating the 2 studies had no significant impact on the overall results.

CONCLUSIONS

Our results showed that MRI was effective in discriminating normal morphologic cartilage from disease but was less sensitive in detecting knee chondral lesions (higher than grade 1). The negative results of MRI should not prevent a diagnostic arthroscopy.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II studies.

Multidirectional instability of the shoulder: rotator interval dimension and capsular laxity evaluation using MR arthrography

OBJECTIVES

To compare the rotator interval and capsular dimension as measured on MR arthrography between patients with clinically diagnosed multidirectional instability (MDI) and control subjects with no instability.

MATERIALS AND METHODS

We retrospectively reviewed a consecutive series of 658 shoulders that had undergone MR arthrography between 2006 and 2010. Of these, 97 shoulders were included in the present study. These shoulders were divided into two groups according to the clinically established diagnoses. The MDI group comprised 47 shoulders with atraumatic multidirectional shoulder instability, and the control group comprised 50 shoulders with no instability. Two independent observers measured the width and depth of the rotator interval, and the capsular dimensions at the anterior, anteroinferior, inferior, posteroinferior, and posterior regions in the two groups using MR arthrography.

RESULTS

The rotator interval width and depth were significantly greater in the MDI group (width, observer 1, 17.7 mm, observer 2, 17.9 mm; depth, observer 1, 8.9 mm, observer 2, 8.8 mm) than in the control group (width, observer 1, 14.3 mm, observer 2, 14.5 mm; depth, observer 1, 5.9 mm, observer 2, 6.2 mm) (p < .001). The capsular dimensions at the inferior and posteroinferior regions were significantly larger in the MDI group (inferior, observer 1, 27.9 mm, observer 2, 27.8 mm; posteroinferior, observer 1, 27.0 mm, observer 2, 27.1 mm) than in the control group (inferior, observer 1, 25.7 mm, observer 2, 25.3 mm; posteroinferior, observer 1, 23.3 mm, observer 2, 23.6 mm) (p < .05). A width greater than 15.2 mm or a depth greater than 6.4 mm of the rotator interval, suggesting MDI, had sensitivities of 81 and 92 % for observer 1, and 79 and 94 % for observer 2, and specificities of 66 and 72 % for observer 1, and 62 and 66 % for observer 2, respectively.

CONCLUSIONS

Measurements of the rotator interval and the size of the distended inferior and posteroinferior joint capsule on MR arthrography are greater in shoulders with clinical MDI than in stable shoulders.

Complications and re-operations after Bristow-Latarjet shoulder stabilization: a systematic review

BACKGROUND

Various methods of bony stabilization, including modifications of Bristow and Latarjet procedures, are considered gold-standard treatment for recurrent anterior shoulder instability but are associated with unique complications and risk of reoperation. The purpose of this study was to identify the prevalence of these complications. We hypothesized that the Bristow-Latarjet procedure would be a successful technique for treatment of shoulder instability but associated with a risk of recurrent postoperative instability, reoperation, and other complications.

METHODS

A systematic review of multiple medical databases included studies reporting outcomes with complication and reoperation rates following original or modified versions of the Bristow or Latarjet shoulder stabilization surgeries.

RESULTS

Forty-five studies were analyzed (1,904 shoulders) (all Level IV evidence). Most subjects were male (82%). The dominant shoulder was the operative shoulder in 64% of cases. Mean subject age was 25.8 years. Mean clinical follow-up was 6.8 years. Ninety percent of surgeries were done open; 9.3% were all-arthroscopic. Total complication rate was 30%. Recurrent anterior dislocation and subluxation rates were 2.9% and 5.8%, respectively. When reported, most dislocations occurred within the first year postoperatively (73%). Nearly 7% of patients required an unplanned reoperation following surgery.

CONCLUSION

Osseous stabilization shoulder surgery using original or modified Bristow and Latarjet procedures has a 30% complication rate. Rates of recurrent dislocation and reoperation were 2.9% and 7%, respectively. Mild loss of external rotation is common. Reoperation rates were lower following all-arthroscopic techniques. There was a greater loss of postoperative external rotation with all-arthroscopic surgery.

Return to sport following anterior cruciate ligament reconstruction

Rates of return to pre-injury sport following anterior cruciate ligament (ACL) reconstruction are less than might be expected from standard outcome measures and there appears to be a rapid decline in sporting participation after two to three years. There are many factors that influence whether an individual will return to sport following this type of surgery. They include not only surgical details and rehabilitation, but also social and psychological factors, as well as demographic characteristics. Age is of particular importance with older patients being less likely to resume their pre-injury sport. It is important that future research clearly identify the pre-injury characteristics of the study cohort when investigating return to sport, and also that there is consistent and precise terminology used to report rates of return to sporting activities. Little is known about how to determine when it is safe to return to sport following ACL reconstruction or how to predict whether an athlete will be able to successfully return to sport. Finally, it needs to be recognised that return to sport following ACL reconstruction is associated with a risk of further injury and the development of osteoarthritis.

Triceps brachii distal tendon reattachment with a double-row technique

Case reports and small series have reported variable results regarding the treatment of choice for patients with triceps brachii tendon ruptures. Early surgical repair has been recommended for acute complete ruptures of the triceps brachii distal tendon to prevent late functional disability. However, controversy exists regarding the optimum surgical technique of reattachment. In addition, various attachment techniques have been described, with none shown clinically to be superior. Therefore, the authors present a technique for triceps brachii distal tendon reattachment following acute complete ruptures and evaluate their results in a series of patients.

Bilateral disruption of soft tissue extensor mechanism of knee: functional outcome and comparison to unilateral injuries

BACKGROUND

Bilateral ruptures of the extensor mechanism are rare.

QUESTIONS/PURPOSE

The purpose of this study was to compare the clinical outcomes of operatively treated unilateral and bilateral knee soft tissue extensor mechanism injuries and to identify risk factors for bilateral disruption.

METHODS

All patients operatively treated for a knee extensor mechanism injury were entered into a database and prospectively followed. Postoperative protocol was standardized for all patients. Demographic data, baseline characteristics, range of motion, complications, pain, and functional status were assessed. The main patient-reported outcome measures used in this study were the SF-36 Health Survey and the Lysholm Scale.

RESULTS

Patients who sustained bilateral injuries were more likely to have one or more systemic medical conditions. There was no statistical difference between the groups with regard to mechanism of injury or body mass index. The average follow-up was 29 months (range 6-60 months). Patient-reported outcomes, in the form of the SF-36 Health Survey and Lysholm scores, were not significantly different between the two groups at final follow-up. Range of motion and quadriceps strength was also similar between the two cohorts. At latest follow-up, 88% of patients with unilateral injuries and 83% of patients with bilateral disruption were able to return to their pre-injury employment.

CONCLUSION

Operatively treated bilateral knee extensor mechanism disruptions fare similar to unilateral injuries with regard to ultimate functional outcome. The presence of one of more preexisting medical conditions was identified as a risk factor for bilateral tendinous disruption.

Acromioclavicular and coracoclavicular PDS augmentation for complete AC joint dislocation showed insufficient properties in a cadaver model

PURPOSE

Optimal surgical treatment of high-grade acromioclavicular joint dislocations is still controversially discussed. The purpose of the present controlled laboratory study was to evaluate whether a polydioxansulfate (PDS(®)) cord augmentation with separate reconstruction of the coracoclavicular (CC) ligaments and the acromioclavicular (AC) complex provides sufficient vertical stability in a biomechanical cadaver model.

METHODS

Twenty-four shoulders of fresh-frozen cadaveric specimen were tested. Cyclic loading and load to failure protocol was performed in vertical direction on 12 native AC joints and repeated after reconstruction. The reconstruction of the coracoclavicular ligament was performed using two CC PDS cerclages and an additional AC PDS cerclage.

RESULTS

In static load testing for vertical force, the native AC joint complex measured 590.1 N (±95.8 N), elongation 13.4 mm (±2.1 mm) and stiffness 48.7 N/mm (±12.0 N/mm). The mean maximum load to failure in the reconstructed joints was 569.9 N (±97.9 N), elongation 18.8 mm (±4.7 mm) and stiffness 37.9 N/mm (±8.0 N/mm). During dynamic testing of the reconstructed AC joints, all specimens reached the critical elongation of 12.0 mm, defined as clinical failure between 200 and 300 N. The mean amount of repetitions at clinical failure was 305. A plastic deformation of the reconstructed specimens throughout cyclic loading could not be detected.

CONCLUSION

The AC joint reconstruction with acromioclavicular and coracoclavicular PDS cord cerclages did not provide the aspired vertical stability in a cadaver model.

LEVEL OF EVIDENCE

Basic Science Study.

Reoperative characteristics after microfracture of knee cartilage lesions in 454 patients

PURPOSE

There is only limited information on those patients who fail following microfracture treatment at the knee joint. Evaluation was made of factors associated with treatment failure and clinical outcome assessment among this collective.

METHODS

The study included a total of 560 patients who had previously undergone microfracture for the treatment of symptomatic knee joint cartilage lesions. For the remainder of this study, inclusion criteria were patients that underwent reoperation at the initially operated knee joint (index knee) due to symptoms related to the primary site of microfracture intervention (failure patients) with a minimum postoperative follow-up of 2 years. The remaining cohort of patients served as internal control (non-failure patients). Chart reviews were performed to identify patient and defect characteristics. Patients were evaluated for postoperative Lysholm knee scores, Tegner activity scale, as well as preoperative and postoperative numeric analogue scales (NAS) for function and pain (10 = highest possible function, no pain).

RESULTS

A total of 454/560 (81.1 %) subjects were completely evaluated. Overall, 123/454 patients (26.9 %) (age at operation 43.9 ± 14.1 years, 56 female, BMI 25.8 ± 3.6, 30 smokers, 61.1 ± 68.3 month symptom duration, postoperative follow-up 5.0 ± 2.1) met the inclusion criteria. The postoperative Lysholm score was 63.0 ± 24.6 and the Tegner score was 4.0; NAS function improved from 2.8 ± 1.8 to 4.8 ± 2.2 (P < 0.001), and NAS pain improved from 3.2 ± 2.1 to 5.0 ± 2.4 (P < 0.001). Exclusively, the overall defect size/knee joint was smaller (P = 0.006), postoperative follow-up was longer (P = 0.002), and existense of previous surgery (77.2 vs. 51.6 %, P < 0.001) was more frequent in failure subjects when comparing to non-failure patients (n = 331). The overall clinical outcome among failure subjects was significantly worse when comparing to non-failure subjects. Regression analysis identified that lower preoperative NAS values, being a smoker, and patello-femoral lesions were associated with a higher probability of reoperation.

CONCLUSION

Within the collective presented here, microfracturing was associated with a high frequency of reoperation. Clinical outcome is worse when compared with that of patients without reoperation. Specific parameters can be identified that increase the eventuality of failure following microfracture treatment.

LEVEL OF EVIDENCE

IV.

Tensile forces on repaired medial meniscal root tears

PURPOSE

The goals of this study were to measure the tensile forces acting on repaired medial meniscal root lesions and to investigate how they depend on femorotibial rotation, flexion, and compressive load.

METHODS

In 6 human cadaveric knees, the posterior medial meniscal root was completely detached and then repaired with a pullout suture. A force transducer was installed such that it measured tensile forces acting on the suture. The resultant tension at the posterior medial meniscal root was measured for flexion angles up to 120° at 2 levels of femorotibial compressive load (100 and 500 N) in neutral, internal, and external rotation of the knee.

RESULTS

Rotation had a highly significant effect on root tension (P < .001). Internal rotation of the femur increased the resultant tension, whereas external rotation decreased it. The tension at the meniscal root was related to the femorotibial load (P < .001). Although no significance was reached, a trend toward higher flexion angles causing more tension was observed. The highest mean tension of 60.1 ± 20.2 N was generated with internal rotation, a 500-N load, and 90° flexion.

CONCLUSIONS

Our study shows in a human in vitro model that motion and weight loading of the knee can generate considerable tensile forces in the posterior medial meniscal root. Internal rotation of the femur increases the resultant tension substantially, whereas external rotation has the opposite effect.

CLINICAL RELEVANCE

The data can potentially aid the surgeon in finding appropriate rehabilitation exercises after a medial meniscal root repair.

Current concepts in the treatment of acromioclavicular joint dislocations

PURPOSE

To conduct a systematic review of the literature in relation to 3 considerations in determining treatment options for patients with acromioclavicular (AC) joint dislocations: (1) operative versus nonoperative management, (2) early versus delayed surgical intervention, and (3) anatomic versus nonanatomic techniques.

METHODS

The PubMed database was searched in October 2011 using the single term acromioclavicular and the following search limits: any date, humans, English, and all adult (19+). Studies were included if they compared operative with nonoperative treatment, early with delayed surgical intervention, or anatomic with nonanatomic surgical techniques. Exclusion criteria consisted of the following: Level V evidence, laboratory studies, radiographic studies, biomechanical studies, fractures or revisions, meta-analyses, and studies reporting preliminary results.

RESULTS

This query resulted in 821 citations. Of these, 617 were excluded based on the title of the study. The abstracts and articles were reviewed, which resulted in the final group of 20 studies that consisted of 14 comparing operative with nonoperative treatment, 4 comparing early with delayed surgical intervention, and 2 comparing anatomic with nonanatomic surgical techniques. The lack of higher level evidence prompted review of previously excluded studies in an effort to explore patterns of publication related to operative treatment of the AC joint. This review identified 120 studies describing 162 techniques for operative reconstruction of the AC joint.

CONCLUSIONS

There is a lack of evidence to support treatment options for patients with AC joint dislocations. Although there is a general consensus for nonoperative treatment of Rockwood type I and II lesions, initial nonsurgical treatment of type III lesions, and operative intervention for Rockwood type IV to VI lesions, further research is needed to determine if differences exist regarding early versus delayed surgical intervention and anatomic versus nonanatomic surgical techniques in the treatment of patients with AC joint dislocations.

LEVEL OF EVIDENCE

Level III, systematic review of Level II and Level III studies and one case series.

ACL tear

Anterior cruciate ligament (ACL) reconstruction has evolved considerably over the past 30 years. This has largely been due to a better understanding of ACL anatomy and in particular a precise description of the femoral and tibial insertions of its two bundles. In the 1980s, the gold standard was anteromedial bundle reconstruction using the middle third of the patellar ligament. Insufficient control of rotational laxity led to the development of double bundle ACL reconstruction. This concept, combined with a growing interest in preservation of the ACL remnant, led in turn to selective reconstruction in partial tears, and more recently to biological reconstruction with ACL remnant conservation. Current ACL reconstruction techniques are not uniform, depending on precise analysis of the type of lesion and the aspect of the ACL remnant in the intercondylar notch.

Increased hip and knee flexion during landing decreases tibiofemoral compressive forces in women who have undergone anterior cruciate ligament reconstruction

BACKGROUND

Those who have undergone anterior cruciate ligament reconstruction (ACLR) have been shown to exhibit increased muscle co-contraction, decreased knee flexion, and elevated tibiofemoral compressive forces. Elevated tibiofemoral compressive forces may be associated with the high risk of developing knee osteoarthritis in this population.

PURPOSE

To examine whether muscle co-contraction and tibiofemoral compressive forces in women after undergoing ACLR can be reduced through the use of a landing strategy that emphasizes greater hip and knee flexion.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten female recreational athletes who had previously undergone ACLR participated in this study. Participants performed a single-legged drop-land task before and after a training session that encouraged them to use greater hip and knee flexion during landing. Peak tibiofemoral compressive forces before and after training were estimated using an electromyography (EMG)-driven knee model that incorporated joint kinematics, EMG, and subject-specific muscle volumes and patellar tendon orientation estimated from magnetic resonance imaging. A co-contraction index (CCI) was calculated to quantify the level of co-contraction between knee flexor and extensor muscles.

RESULTS

After training, peak hip and knee flexion as well as hip and knee flexion excursions increased significantly. Additionally, participants demonstrated a significant decrease after training in the areas of muscle co-contraction (CCI [mean ± SD], 0.28 ± 0.10 vs 0.18 ± 0.05; P < .001) and peak tibiofemoral compressive force (97.3 ± 8.0 vs 91.3 ± 10.2 N·kg(-1); P = .044).

CONCLUSION

Increased muscle co-contraction as well as elevated tibiofemoral compressive loads observed in individuals following ACLR can be reduced by using a landing strategy that encourages greater hip and knee flexion.

CLINICAL RELEVANCE

The findings of the current study provide useful information for the growth of rehabilitation and/or intervention programs aimed to decrease knee joint loading to prevent or delay the development of knee osteoarthritis in those who have undergone ACLR.

The value of the sagittal-oblique MRI technique for injuries of the anterior cruciate ligament in the knee

BACKGROUND

Complete rupture of the anterior cruciate ligament (ACL) does not represent a diagnostic problem for the standard magnetic resonance (MR) protocol of the knee. Lower accuracy of the standard MR protocol for partial rupture of the ACL can be improved by using additional, dedicated MR techniques. The study goal was to draw a comparison between sagittal-oblique MR technique of ACL imaging versus flexion MR technique of ACL imaging and, versus ACL imaging obtained with standard MR protocol of the knee.

PATIENTS AND METHODS

In this prospective study we included 149 patients who were referred to magnetic resonance imaging (MRI) examination due to knee soft tissues trauma during 12 months period. MRI signs of ACL trauma, especially detection of partial tears, number of slices per technique showing the whole ACL, duration of applied additional protocols, and reproducibility of examination were analysed.

RESULTS

Accuracy of standard MRI protocol of the knee comparing to both additional techniques is identical in detection of a complete ACL rupture. Presentations of the partial ruptures of ACL using flexion technique and sagittal-oblique technique were more sensitive (p<0.001) than presentation using standard MR protocol. There was no statistically significant difference between MRI detection of the ruptured ACL between additional techniques (p> 0.65). Sagittal-oblique technique provides a higher number of MRI slices showing the whole course of the ACL and requires a shorter scan time compared to flexion technique (p<0.001).

CONCLUSIONS

Both additional techniques (flexion and sagittal-oblique) are just as precise as the standard MR protocol for the evaluation of a complete rupture of the ACL, so they should be used in cases of suspicion of partial rupture of the ACL. Our study showed sagittal-oblique technique was superior, because it did not depend on patient's ability to exactly repeat the same external rotation if standard MR protocol was used or to repeat exactly the same flexion in flexion MR technique in further MR examinations. Sagittal-oblique technique does not require the patient's knee to be repositioned, which makes this technique faster. We propose this technique in addition to the standard MR protocol for detection of partial ACL tears.

Does obesity negatively affect the functional results of arthroscopic partial meniscectomy? A retrospective cohort study

PURPOSE

The purpose of this study was to evaluate the impact of body mass index (BMI) on early functional results of patients who undergo isolated partial meniscectomy.

METHODS

The functional results for 1,090 patients who underwent partial meniscectomy, in 2 different orthopaedic clinics, were evaluated retrospectively. The study includes cases with arthroscopic partial meniscectomy for isolated meniscal tears; patients with concomitant knee pathology were excluded. Three hundred forty-one (31%) patients with isolated lateral meniscal tears, 628 (58%) patients with isolated medial meniscal tears, and 121 (11%) patients with both medial and lateral meniscal tears underwent arthroscopic partial meniscectomy. We divided these patients into 3 subgroups on the basis of their BMI; <26, between 26 and 30, ≥30. Preoperative functional results were compared with 1-year postoperative follow-up results using the International Knee Documentation Committee (IKDC),(26) Lysholm Knee Scale,(27) and Oxford Scoring System(28) scores.

RESULTS

According to all 3 knee scales, age, side of lesion, and tear type had no effect on functional outcome. When compared with the group with BMI <26, the patients with BMI between 26 and 30 and the patients with BMI ≥30 had significantly worse outcomes as measured by the IKDC, Oxford Scoring System, and Lysholm Knee Scale scores. Patients with BMI between 26 and 30 and ≥30 did not have significantly different functional outcomes.

CONCLUSIONS

Short-term outcomes after arthroscopic partial menisectomy reflect significant improvement in subjective outcome. However, patients with moderate or significant obesity (BMI >26) have inferior short-term outcomes compared with nonobese patients.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

MRI diagnosis of ACL bundle tears: value of oblique axial imaging

OBJECTIVE

To investigate the diagnostic accuracy of oblique axial intermediate weighting MR imaging in detecting partial thickness anterior cruciate ligament (ACL) bundle tears.

MATERIALS AND METHODS

The study protocol was approved by the institutional ethics committee. Sixty-one subjects (43 male, 18 female; mean age 27.4 years; range 9 to 57 years) with clinically suspected ACL tear or meniscal tear between September 2009 and January 2011 were studied with MRI and arthroscopy. Detection of partial tear for the ACL as a whole and for each ACL bundle by protocol A (standard orthogonal sequences) and protocol B (standard orthogonal sequences plus oblique axial intermediate weighted imaging) was compared in a blinded fashion. Performance characteristics for protocol A and protocol B were compared using sensitivity, specificity, accuracy and ROC curves. A two-tailed p value of <0.05 indicated statistical significance.

RESULTS

Fifteen (24.6%) normal, 15 (24.6%) partial and 31 complete tears were diagnosed by arthroscopy. Sensitivity, specificity and accuracy of protocol A for the diagnosis of partial tear of the ACL was 33%, 87% and 74%, while for protocol B the values were 87%, 87% and 87% respectively. The area under the curve (AUC) for the diagnosis of partial ACL tear and individual bundle tear was higher for protocol B, although this difference did not reach statistical significance (p > 0.05).

CONCLUSION

The addition of oblique axial imaging to standard MR imaging improves diagnostic accuracy for detecting partial tears of the ACL as well as individual bundle tears of the ACL.

Double-bundle anatomical versus single-bundle isometric medial patellofemoral ligament reconstruction for patellar dislocation

PURPOSE

The purpose of this study was to evaluate reconstruction of the medial patellofemoral ligament (MPFL) using the double-bundle anatomical or single-bundle isometric procedure with respect to the patients' clinical outcomes.

METHODS

In this retrospective study, we evaluated the clinical outcome of double-bundle anatomical versus single-bundle isometric reconstruction of the MPFL for patellar dislocation patients. Sixty-three patients were included in this study from August 2004 to January 2008. From August 2004 to September 2006, MPFL reconstruction using a single-bundle isometric technique was performed in 21 patients (26 knees). Since October 2006, the double-bundle anatomical reconstruction of the MPFL has been used as the routine surgical procedure. It was performed in 37 patients (44 knees). Fifty-eight patients (70 knees) could be followed up. According to the different techniques, we divided the patients into two groups: group D with double-bundle anatomical reconstruction (37 patients) and group S with single-bundle isometric reconstruction (21 patients). Clinical evaluation consisted of the number with a patellar re-dislocation, patellar apprehension sign, Kujala score, subjective questionnaire score, the patella lateral shift rate and patellar tilt angle measured by cross-sectional CT scan.

RESULTS

According to the Kujala score and the subjective questionnaire score, the outcome of the double-bundle group was better than the outcome of the single-bundle group especially in the long-term. Patellar re-dislocation occurred in three patients in the group S, while no re-dislocation occurred in the group D. In total, 26.9 % of group S was considered to have patellar instability, compared to 4.54 % of the group D. After operation, the patellar tilt angle (PTA) and the patella lateral shift rate (PLSR) were restored to the normal range, with statistical significance (P < 0.05) compared to the preoperative state.

CONCLUSION

Single- and double-bundle reconstruction of the MPFL can both effectively restore patella stability and improve knee function. However, outcomes in the follow-up period showed that the double-bundle surgery procedure was much better than in single-bundle surgery.

Pediatric upper extremity stress injuries

PURPOSE OF REVIEW

To provide primary care physicians with strategies to evaluate and manage pediatric upper extremity stress injuries related to overuse with a focus on anatomic location, patient history, physical examination, and imaging.

RECENT FINDINGS

Children are susceptible to stress injuries due to their open physes. The physeal cartilage of epiphyses and apophyses is the weakest structure in the developing skeleton. The differential diagnosis for pediatric stress injuries includes injury to the bone, physis, epiphysis, and apophysis. Most stress injuries in children improve with rest. Missed or misdiagnosed stress injuries can lead to growth abnormalities and potential malalignment.

SUMMARY

Awareness of stress injuries is important for timely diagnosis and prevention of sequelae. A thorough history, focused physical examination, and proper imaging studies are crucial steps to identify upper extremity stress injuries in the pediatric population.

Validation of the instability shoulder index score in a multicenter reliability study in 114 consecutive cases

BACKGROUND

Anterior shoulder stabilization surgery with the arthroscopic Bankart procedure can have a high recurrence rate in certain patients. Identifying these patients to modify outcomes has become a focal point of research.

PURPOSE

The Instability Shoulder Index Score (ISIS) was developed to predict the success of arthroscopic Bankart repair. Scores range from 0 to 10, with higher scores predicting a higher risk of recurrence after stabilization. The interobserver reliability of the score is not known.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

This is a prospective multicenter (North America and Europe) study of patients suffering from shoulder instability and waiting for stabilization surgery. Five pairs of independent evaluators were asked to score patient instability severity with the ISIS. Patients also completed functional scores (Western Ontario Shoulder Instability Index [WOSI], Disabilities of the Arm, Shoulder and Hand-short version [QuickDASH], and Walch-Duplay test). Data on age, sex, number of dislocations, and type of surgery were collected. The test-retest method and intraclass correlation coefficient (ICC: >0.75 = good, >0.85 = very good, and >0.9 = excellent) were used for analysis.

RESULTS

A total of 114 patients with anterior shoulder instability were included, of whom 89 (78%) were men. The mean age was 28 years. The ISIS was very reliable, with an ICC of 0.933. The mean number of dislocations per patient was higher in patients who had an ISIS of ≥6 (25 vs 14; P = .05). Patients who underwent more complex arthroscopic procedures such as Hill-Sachs remplissage or open Latarjet had higher preoperative ISIS outcomes, with a mean score of 4.8 versus 3.4, respectively (P = .002). There was no correlation between the ISIS and the quality-of-life questionnaires, with Pearson correlations all >0.05 (WOSI = 0.39; QuickDASH = 0.97; Walch-Duplay = 0.08).

CONCLUSION

Our results show that the ISIS is reliable when used in a multicenter study with anterior traumatic instability populations. There was no correlation between the ISIS and the quality-of-life questionnaires, but surgical decisions reflected its increased use.

Femoral cortical suspension devices for soft tissue anterior cruciate ligament reconstruction: a comparative biomechanical study

BACKGROUND

Optimization of anterior cruciate ligament (ACL) fixation is desired to improve graft healing. New soft tissue cortical suspension devices for femoral tunnel fixation should be biomechanically evaluated.

HYPOTHESIS

All femoral fixation devices would prevent a clinically significant amount of displacement and support loads significantly larger than in situ forces experienced by the ACL during early rehabilitation.

STUDY DESIGN

Controlled laboratory study.

METHODS

Four cortical soft tissue ACL graft suspension devices were tested under cyclic and pull-to-failure loading conditions in both an isolated device-only setup and as a complete bone-device-tendon construct in porcine femurs using a tensile testing machine.

RESULTS

There were significant differences in the ultimate failure loads among the devices. The highest ultimate failure loads when tested as a construct were observed for the XO Button (1748 N), followed by the Endobutton CL (1456 N), ToggleLoc with ZipLoop (1334 N), and TightRope RT (859 N). Cyclic displacement after 1000 cycles during isolated device testing was less than 1 mm for all devices. Cyclic displacements after 1000 cycles in the porcine construct were 1.88 mm, 2.74 mm, 3.34 mm, and 1.82 mm for the Endobutton, TightRope, ToggleLoc, and XO Button, respectively; all were significantly different from each other except when the Endobutton was compared with the XO Button. The ToggleLoc exceeded the 3.0-mm displacement threshold defined as a clinical failure. The most displacement occurred during the first cycle, especially for the adjustable-length loop devices. Stiffness reapproximated the native ACL stiffness for all constructs.

CONCLUSION

The Endobutton, TightRope, and XO Button have the necessary biomechanical properties with regard to ultimate failure strength, displacement, and stiffness for initial fixation of soft tissue grafts in the femoral tunnel for ACL reconstruction. The ToggleLoc had sufficient ultimate failure strength but crossed our 3.0-mm clinical failure threshold for cyclic displacement. Although this study was not designed to compare fixed and adjustable-length loop devices, it was noted that both fixed-loop devices allowed less cyclic displacement and initial displacement.

CLINICAL RELEVANCE

Adjustable-length loop devices may need to be retensioned after cycling the knee and fixing the tibial side to account for the increased initial displacement seen with these devices.

The prevalence of acetabular anomalies associated with pistol-grip-deformity in osteoarthritic hips

BACKGROUND

Acetabular retroversion, excessive acetabular coverage and abnormal head-neck-junction with a so-called "pistol-grip-deformity" were added to the classical description of hip dysplasia to describe pathological hip morphology. The aim of the current study was the detection of pathological acetabular geometry in patients with an abnormal head-neck-junction.

HYPOTHESIS

Femoroacetabular impingement and hip dysplasia features are frequent in patients with end-stage osteoarthritis before 60 years of age.

MATERIALS AND METHODS

We analysed our data bank retrospectively for all patients who received a Total Hip Arthroplasty (THA) due to end-stage osteoarthritis before the age of 60 years. The pelvic-views and the Dunn-view of these patients were screened for an abnormal head-neck-junction by measuring the head-ratio and the alpha-angle. An orthopaedic surgeon and a radiologist did this independently. These radiographies were measured for signs of acetabular dysplasia, excessive acetabular coverage and crossing sign.

RESULTS

A consecutive series of 135 total hip arthroplasties were performed in patients aged less or equal to 60 years because of end-stage osteoarthritis. From these, 81 patients were classified as having an abnormal head-neck-junction. The mean head-ratio in these 81 patients was 1.52±0.35, the mean alpha-angle was 62.5°±9.3°. The mean CE-angle of these 81 patients was 35.8°±10.4°, the mean CA-angle was 36.7°±5.7°, the mean depth-width ratio was 49.1±10, the mean extrusion index was 19.1±9.2 and the mean CCD-angle was 131.7°±7.3°. Of these 81hips, 14 had isolated pistol-grip-deformity, while 11 hips had associated dysplasia, 38 had excessive acetabular coverage, and 14 had crossing sign. In addition, a crossing sign was identified in four of the 11 dysplastic hips and 19 of the 38 of the hips having excessive acetabular coverage. There was no statistically significant difference in regard to the age between the four groups (P=0.087). In contrast, the hips that had excessive acetabular coverage had increased CE-angle (44.6°±7.2°) and decreased extrusion index (12.6±6.5) (P<0.001), while dysplastic hips had increased roof obliquity (17.5°±4.5°) and increased extrusion index (29.6±9.1), as well as decreased CE-angle (20.7°±3.0°) (P<0.001).

CONCLUSION

There is a high coincidence of radiographic findings associated with an abnormal head-neck-junction consisting in excessive acetabular coverage and retroversion as well as hip dysplasia. These results advocate for restoring of the normal anatomy at the early stage to prevent end-stage osteoarthritis.

LEVEL OF EVIDENCE

Level IV retrospective historical study.

Effect of Hopping Frequency on Bilateral Differences in Leg Stiffness

Understanding the degree of leg stiffness during human movement would provide important information that may be used for injury prevention. In the current study, we investigated bilateral differences in leg stiffness during one-legged hopping. Ten male participants performed one-legged hopping in place, matching metronome beats at 1.5, 2.2, and 3.0 Hz. Based on a spring-mass model, we calculated leg stiffness, which is defined as the ratio of maximal ground reaction force to maximum center of mass displacement at the middle of the stance phase, measured from vertical ground reaction force. In all hopping frequency settings, there was no significant difference in leg stiffness between legs. Although not statistically significant, asymmetry was the greatest at 1.5 Hz, followed by 2.2 and 3.0 Hz for all dependent variables. Furthermore, the number of subjects with an asymmetry greater than the 10% criterion was larger at 1.5 Hz than those at 2.2 and 3.0 Hz. These results will assist in the formulation of treatment-specific training regimes and rehabilitation programs for lower extremity injuries.

In vitro acute load to failure and eyelet abrasion testing of a novel veterinary screw-type mini-anchor design

OBJECTIVE

To determine acute load to failure (ALF) and suture abrasion (SA) at 0° and 90° for a novel screw-type mini-anchor design.

STUDY DESIGN

Biomechanical in vitro study.

SAMPLE POPULATION

Synthetic bone.

METHODS

Twenty mini-anchors were inserted into synthetic bone blocks assigned to 1 of 2 groups (0° ALF, 90° ALF). Pullout was performed at 5 mm/min. ALF, yield strength and stiffness were calculated. SA constructs were created with 4 groups of 5 anchors each with either 30 lb nylon leader line (NLL), 40 lb NLL, #2 Fiberwire or #5 Fiberwire. SA was performed at 0° and 90° with a sinusoidal wave form at 0.5 Hz and 10 N load for 1000 cycles or until failure. Data were summarized as mean ± SD. ALF data were analyzed using t-tests. SA data were analyzed using log rank, Tukey-adjusted pairwise comparisons and sign tests. Significance was set at P = .05.

RESULTS

Mean ± SD ALF at 0° and 90° was 431.8 ± 70.8 N and 683 ± 48.7 N, respectively. 90° ALF was significantly higher. Yield strength and stiffness were not significantly different at 0° and 90°. #5 and #2 Fiberwire survived significantly more cycles than 40 lb and 30 lb NLL at 90°. At 0°, 30 lb NLL survived significantly less cycles than either Fiberwire size. Suture orientation did not have a significant effect on SA for Fiberwire constructs.

CONCLUSION

The novel mini-anchor has ALF comparable to other mini-anchors. Fiberwire survived more cycles in the novel anchor eyelet than NLL and FW suture orientation in the eyelet did not affect SA.

Análise da aptidão física, da antropometria e da prevalência de sintomas osteomusculares na categoria infanto-juvenil do voleibol

INTRODUÇÃO: O controle da ocorrência de lesões durante todo o processo de treinamento possui expressiva importância para o atleta, bem como o monitoramento das adaptações físicas decorrentes do programa de exercícios. OBJETIVOS: Descrever o perfil antropométrico e a aptidão física dos times de voleibol infanto-juvenil e determinar a prevalência de sintomas osteomusculares. Métodos: Estudo longitudinal. Participaram 38 atletas da categoria infanto-juvenil do voleibol monitorados por quatro meses através de testes de aptidão física, mensurações antropométricas e do questionário de sintomas osteomusculares. Foram utilizadas análises descritivas e comparativas através de médias e desvio padrão e teste t de Student. RESULTADOS: Os principais indicadores estatisticamente significativos observaram-se nas variáveis: estatura (p = 0,001 para o sexo masculino e 0,003 para o feminino) envergadura para os meninos (p < 0,001), arremesso (p = 0,003 para os meninos e p < 0,001 para as meninas), abdominal para as meninas (p = 0,001). A maioria dos sintomas prevaleceu nas costas (56,5%), ombros (52,2%), quadris/coxas (52,2%) e joelhos (52,2%). CONCLUSÃO: O perfil dos atletas apresentou como principais características: o aumento da estatura, envergadura e força explosiva de membros superiores, resistência abdominal e agilidade. A grande frequência de respostas afirmativas de queixas nas costas, parte inferior e superior, ombros, quadril/coxas, joelhos e tornozelos reforça a necessidade de um acompanhamento a longo prazo da reação dos jovens desportistas ao treinamento, bem como fomenta estratégias de prevenção.

Influence of anthropometric features on graft diameter in ACL reconstruction

BACKGROUND

There is a paucity of literature regarding the influence of anthropometric features on the hamstring graft obtained in ACL reconstruction. This study was undertaken to assess the influence of anthropometric measurements on the graft diameter obtained at ACL reconstruction surgery within the European population. We hypothesise that anthropometric features do influence graft thickness in ACL reconstruction.

MATERIALS AND METHODS

Data from 121 consecutive patients who had undergone ACL reconstruction by the same surgeon using quadruple hamstring grafts were analysed. The body mass index (BMI), height and weight of these patients were correlated with the graft diameter obtained during surgery. Regression analysis was undertaken to assess the influence of individual anthropometric variables on the graft diameter.

RESULTS

There were 121 patients with mean age of 32 years (14-55). There was a statistically significant positive correlation individually between the height and graft diameter (r = 0.38, p < 0.01) as well as between the body weight and graft diameter (r = 0.29, p < 0.01). However, when the body mass index was calculated, the correlation was not statistically significant (r = 0.08, p > 0.1). Regression analysis confirmed that BMI was not statistically significant as a predictor of hamstring graft diameter whereas height was statistically the most important predictor (F = 20.1; p < 0.01).This yielded the predictive equation, graft diameter = 4.5 + 0.02 x Ht (in cm).

CONCLUSION

Although body mass index did not significantly correlate, body height may be a predictive variable in predicting the graft diameter in ACL reconstruction and provide useful pre operative information.