The effects of femoral graft placement on in vivo knee kinematics after anterior cruciate ligament reconstruction

Achieving anatomical graft placement remains a concern in Anterior Cruciate Ligament (ACL) reconstruction. The purpose of this study was to quantify the effect of femoral graft placement on the ability of ACL reconstruction to restore normal knee kinematics under in vivo loading conditions. Two different groups of patients were studied: one in which the femoral tunnel was placed near the anterior and proximal border of the ACL (anteroproximal group, n=12) and another where the femoral tunnel was placed near the center of the ACL (anatomic group, n=10) MR imaging and biplanar fluoroscopy were used to measure in vivo kinematics in these patients during a quasi-static lunge. Patients with anteroproximal graft placement had up to 3.4mm more anterior tibial translation, 1.1mm more medial tibial translation and 3.7° more internal tibial rotation compared to the contralateral side. Patients with anatomic graft placement had motion that more closely replicated that of the intact knee, with anterior tibial translation within 0.8mm, medial tibial translation within 0.5mm, and internal tibial rotation within 1°. Grafts placed anteroproximally on the femur likely provide insufficient restraint to these motions due to a more vertical orientation. Anatomical femoral placement of the graft is more likely to reproduce normal ACL orientation, resulting in a more stable knee. Therefore, achieving anatomical graft placement on the femur is crucial to restoring normal knee function and may decrease the rates of joint degeneration after ACL reconstruction.

Biomechanical evaluation of two reconstruction techniques for posterolateral instability of the knee

We evaluated two reconstruction techniques for a simulated posterolateral corner injury on ten pairs of cadaver knees. Specimens were mounted at 30° and 90° of knee flexion to record external rotation and varus movement. Instability was created by transversely sectioning the lateral collateral ligament at its midpoint and the popliteus tendon was released at the lateral femoral condyle. The left knee was randomly assigned for reconstruction using either a combined or fibula-based treatment with the right knee receiving the other. After sectioning, laxity increased in all the specimens. Each technique restored external rotatory and varus stability at both flexion angles to levels similar to the intact condition. For the fibula-based reconstruction method, varus laxity at 30° of knee flexion did not differ from the intact state, but was significantly less than after the combined method.

Both the fibula-based and combined posterolateral reconstruction techniques are equally effective in restoring stability following the simulated injury.

Femoral tunnel placement during anterior cruciate ligament reconstruction: an in vivo imaging analysis comparing transtibial and 2-incision tibial tunnel-independent techniques

BACKGROUND

Recent studies have questioned the ability of the transtibial technique to place the anterior cruciate ligament graft within the footprint of the anterior cruciate ligament on the femur. There are limited data directly comparing the abilities of transtibial and tibial tunnel-independent techniques to place the graft anatomically at the femoral attachment site of the anterior cruciate ligament in patients.

HYPOTHESIS

Because placement with the tibial tunnel-independent technique is unconstrained by the tibial tunnel, it would allow for more anatomic tunnel placement compared with the transtibial technique.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

High-resolution, multiplanar magnetic resonance imaging and advanced 3-dimensional modeling techniques were used to measure in vivo femoral tunnel placement in 8 patients with the transtibial technique and 8 patients with a tibial tunnel-independent technique. Femoral tunnel placement in 3 dimensions was measured relative to the center of the native anterior cruciate ligament attachment on the intact contralateral knee.

RESULTS

The tibial tunnel-independent technique placed the graft closer to the center of the native anterior cruciate ligament attachment compared with the transtibial technique. The transtibial technique placed the tunnel center an average of 9 mm from the center of the anterior cruciate ligament attachment, compared with 3 mm for the tibial tunnel-independent technique. The transtibial technique resulted in a more anterior and superior placement of the tunnel compared with the tibial tunnel- independent technique.

CONCLUSION

The tibial tunnel-independent technique allowed for more anatomic femoral tunnel placement compared with the transtibial technique.

Continental variations in preoperative and postoperative management of patients with anterior cruciate ligament repair

AIM

Surgeon decision making for non-operative anterior cruciate ligament (ACL) treatment and postoperative rehabilitation is influenced by a myriad of factors. The aim of this study was to investigate intercontinental differences in surgeon decision making for care of the ACL deficient patient. The authors hypothesized that significant variation in clinical decision of ACL deficient patients existed among surgeons in different continents.

METHODS

This study involved a survey design, which met the checklist for reporting results of internet e-surveys (CHERRIES) guidelines. The survey was administered to orthopedic surgeons in 15 countries and involved standardized follow up and design. Questions related to non-operative care management and postoperative/rehabilitative management were provided to each respondent. Statistical analyses included multivariate comparisons among continents and regression findings for likelihood of targeting longer term non-operative treatment.

RESULTS

Over six hundred (634) surgeons completed the survey, representing six continents. Continental variations were found in non-operative surgical decision making and postoperative/rehabilitative management. Significant differences were noted in nearly all clinical decision making categories.

CONCLUSION

Variations do exist across continents in the non-operative and postoperative/rehabilitative management of patients with an ACL tear. Continental variations and disparate emphases such as activity level, age during injury, and bracing influenced treatment decision making, which could lead to variations in outcomes, costs, and appropriate care.

Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests

OBJECTIVE

To compile and critique research on the diagnostic accuracy of individual orthopaedic physical examination tests in a manner that would allow clinicians to judge whether these tests are valuable to their practice.

METHODS

A computer-assisted literature search of MEDLINE, CINAHL, and SPORTDiscus databases (1966 to October 2006) using keywords related to diagnostic accuracy of physical examination tests of the shoulder. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used to critique the quality of each paper. Meta-analysis through meta-regression of the diagnostic odds ratio (DOR) was performed on the Neer test for impingement, the Hawkins-Kennedy test for impingement, and the Speed test for superior labral pathology.

RESULTS

Forty-five studies were critiqued with only half demonstrating acceptable high quality and only two having adequate sample size. For impingement, the meta-analysis revealed that the pooled sensitivity and specificity for the Neer test was 79% and 53%, respectively, and for the Hawkins-Kennedy test was 79% and 59%, respectively. For superior labral (SLAP) tears, the summary sensitivity and specificity of the Speed test was 32% and 61%, respectively. Regarding orthopaedic special tests (OSTs) where meta-analysis was not possible either due to lack of sufficient studies or heterogeneity between studies, the list that demonstrates both high sensitivity and high specificity is short: hornblowers's sign and the external rotation lag sign for tears of the rotator cuff, biceps load II for superior labral anterior to posterior (SLAP) lesions, and apprehension, relocation and anterior release for anterior instability. Even these tests have been under-studied or are from lower quality studies or both. No tests for impingement or acromioclavicular (AC) joint pathology demonstrated significant diagnostic accuracy.

CONCLUSION

Based on pooled data, the diagnostic accuracy of the Neer test for impingement, the Hawkins-Kennedy test for impingement and the Speed test for labral pathology is limited. There is a great need for large, prospective, well-designed studies that examine the diagnostic accuracy of the numerous physical examination tests of the shoulder. Currently, almost without exception, there is a lack of clarity with regard to whether common OSTs used in clinical examination are useful in differentially diagnosing pathologies of the shoulder.

A comparison of cleat types during two football-specific tasks on FieldTurf

OBJECTIVE

To examine the effect of different cleat plate configurations on plantar pressure during two tasks.

DESIGN

Thirty-six athletes ran an agility course 5 times while wearing 4 different types of Nike Vitoria cleats: (1) bladed, (2) elliptical firm ground, (3) hard ground and (4) turf. Plantar pressure data were recorded during a side cut and a cross cut using Pedar-X insoles.

SETTING

Controlled laboratory study

PARTICIPANTS

No history of lower extremity injury in the past 6 months, no previous foot or ankle surgery, not currently wearing foot orthotics and play a cleated sport at least twice a week.

MAIN OUTCOME MEASUREMENTS

Total foot contact time, contact area, maximum force, peak pressure and the force-time integral (FTI) in the medial, middle and lateral regions of the forefoot were collected. A 1x4 ANOVA (alpha = 0.05) was performed on each dependent variable. A Bonferroni adjustment was conducted (alpha = 0.008).

RESULTS

In the cross cut task, statistical differences between cleats were observed in three variables: total foot peak pressure, lateral forefoot FTI, and lateral forefoot normalised maximum force. In the side cut task, statistical differences between cleats were observed in 4 variables: total foot peak pressure, the medial and middle forefoot FTI, and the medial and middle forefoot normalised maximum force.

CONCLUSIONS

Significant differences in forefoot loading patterns existed between cleat types. Based on the results of this study, it might be beneficial to increase the forefoot cushioning in cleats in an attempt to decrease loading in these regions of the foot.

Duke Surgery Research Central: an open-source Web application for the improvement of compliance with research regulation

Background

Although regulatory compliance in academic research is enforced by law to ensure high quality and safety to participants, its implementation is frequently hindered by cost and logistical barriers. In order to decrease these barriers, we have developed a Web-based application, Duke Surgery Research Central (DSRC), to monitor and streamline the regulatory research process.

Results

The main objective of DSRC is to streamline regulatory research processes. The application was built using a combination of paper prototyping for system requirements and Java as the primary language for the application, in conjunction with the Model-View-Controller design model. The researcher interface was designed for simplicity so that it could be used by individuals with different computer literacy levels. Analogously, the administrator interface was designed with functionality as its primary goal. DSRC facilitates the exchange of regulatory documents between researchers and research administrators, allowing for tasks to be tracked and documents to be stored in a Web environment accessible from an Intranet. Usability was evaluated using formal usability tests and field observations. Formal usability results demonstrated that DSRC presented good speed, was easy to learn and use, had a functionality that was easily understandable, and a navigation that was intuitive. Additional features implemented upon request by initial users included: extensive variable categorization (in contrast with data capture using free text), searching capabilities to improve how research administrators could search an extensive number of researcher names, warning messages before critical tasks were performed (such as deleting a task), and confirmatory e-mails for critical tasks (such as completing a regulatory task).

Conclusion

The current version of DSRC was shown to have excellent overall usability properties in handling research regulatory issues. It is hoped that its release as an open-source application will promote improved and streamlined regulatory processes for individual academic centers as well as larger research networks.

The assessment of athletic hip injury

The differential diagnosis of athletic hip pain is extensive. The physical demands of sport place the athlete at increased risk to injure the hip. The basis of successful treatment of the athlete with hip pain lies in the ability of the physician to assess and diagnose the etiology accurately. A thorough understanding of the evaluation of the athlete with hip pain allows for an earlier diagnosis, earlier treatment, and ultimately an earlier return to sport.

Effects of technique variations on knee biomechanics during the squat and leg press

PURPOSE

The specific aim of this project was to quantify knee forces and muscle activity while performing squat and leg press exercises with technique variations.

METHODS

Ten experienced male lifters performed the squat, a high foot placement leg press (LPH), and a low foot placement leg press (LPL) employing a wide stance (WS), narrow stance (NS), and two foot angle positions (feet straight and feet turned out 30 degrees ).

RESULTS

No differences were found in muscle activity or knee forces between foot angle variations. The squat generated greater quadriceps and hamstrings activity than the LPH and LPL, the WS-LPH generated greater hamstrings activity than the NS-LPH, whereas the NS squat produced greater gastrocnemius activity than the WS squat. No ACL forces were produced for any exercise variation. Tibiofemoral (TF) compressive forces, PCL tensile forces, and patellofemoral (PF) compressive forces were generally greater in the squat than the LPH and LPL, and there were no differences in knee forces between the LPH and LPL. For all exercises, the WS generated greater PCL tensile forces than the NS, the NS produced greater TF and PF compressive forces than the WS during the LPH and LPL, whereas the WS generated greater TF and PF compressive forces than the NS during the squat. For all exercises, muscle activity and knee forces were generally greater in the knee extending phase than the knee flexing phase.

CONCLUSIONS

The greater muscle activity and knee forces in the squat compared with the LPL and LPH implies the squat may be more effective in muscle development but should be used cautiously in those with PCL and PF disorders, especially at greater knee flexion angles. Because all forces increased with knee flexion, training within the functional 0-50 degrees range may be efficacious for those whose goal is to minimize knee forces. The lack of ACL forces implies that all exercises may be effective during ACL rehabilitation.

Ligamentous restraints of the second tarsometatarsal joint: a biomechanical evaluation

Ligamentous injury of the tarsometatarsal joint complex is an uncommon, but disabling condition that frequently occurs in elite athletes. There are few options for managing these injuries, in part because the relative mechanical contribution of the ligaments of the tarsometatarsal joint is unknown, complicating decisions regarding which ligaments need reconstruction. In the current study, strength and stiffness of the dorsal, plantar, and Lisfranc ligaments of 20 paired cadaver feet were measured and compared. The plantar and Lisfranc ligaments were significantly stiffer and stronger than the dorsal ligament, and the Lisfranc ligament was significantly stronger and stiffer than the plantar ligament.

Spine injuries associated with falls from hunting tree stands

Spinal injuries resulting from falls out of tree stands are often associated with concomitant neurologic deficit, prolonged hospitalization, and long-term disability. The purpose of this study was to review the types of spinal injuries that resulted from falls from hunting tree stands. We retrospectively reviewed 27 patients who came to our institution for treatment of spine injuries related to tree-stand accidents between 1981 and 1997. Eleven percent of the falls were alcohol related. Mean height of the fall was 19.6 feet (range, 10 to 35 feet). There were 17 burst fractures, 8 wedge compression fractures, 4 fractures involving the posterior elements, and 1 coronal fracture of the sacral body. Significant neurologic injury occurred in 12 patients (44%). Sixteen patients (59%) had associated injuries. Nine patients (33%) had open reduction, internal fixation, and fusion of their spine fractures. One patient was treated with a halo jacket. The remaining patients were treated in rigid, molded, polypropylene thoracolumbar orthoses or lumbosacral corsets. Accidental falls from tree stands may result in significant spinal fractures often associated with concomitant neurologic injury, extended hospitalization, and permanent disability. Many of these injuries may be prevented through aggressive hunter safety education.

Intramuscular corticosteroid injection for hamstring injuries. A 13-year experience in the National Football League

The purpose of this study was to assess the safety of intramuscular corticosteroid injection in selected, severe hamstring injuries in professional football players. Clinicians have been reluctant to use corticosteroid injections in or around muscle-tendon units because of concern of incomplete healing or rupture. We retrospectively reviewed the computer database of one National Football League team for all hamstring injuries requiring treatment between January 1985 and January 1998. We found that 431 players had suffered such injury. We developed a clinical grading system to identify hamstring injury severity and to stratify players for treatment. Fifty-eight players (13%) sustained severe, discrete injuries with a palpable defect within the substance of the muscle and were treated with intramuscular injection of corticosteroid and anesthetic. There were no complications related to the injection of corticosteroid. Only nine players (16%) missed any games as a result of their injury. Final examination revealed no strength deficits, normal muscle bulk and tone, and the ability to generate normal power. We believe that the grading system we developed can assist in selection of injury type for injection. Although lack of a control group limits statements of efficacy of injection, our impression is that intramuscular corticosteroid injection hastens players' return to full play and lessens the game and practice time they miss.

The early effect of ibuprofen on the mechanical properties of healing medial collateral ligament

We tested the hypothesis that injured ligaments in rabbits treated with ibuprofen would have decreased values of mechanical properties compared with the values of those treated with a placebo. In 24 New Zealand White rabbits, the medial collateral ligament of one hindlimb was ruptured; the contralateral ligament served as an internal control. The rabbits were treated orally, twice daily, with a 14-day course of either 35 mg of ibuprofen per kilogram of body weight or a placebo. The rabbits were sacrificed at 14 or 28 days, and the ligaments were tested in tension to failure at 0.15 mm/sec. There was no statistically significant difference in the values of mechanical properties of ligaments from rabbits treated with ibuprofen versus those treated with placebo at either 14 or 28 days after injury. Our findings suggest that there is no early deleterious effect of a short course of ibuprofen on the mechanical behavior of medial collateral ligaments.

Familial calcification of the superior transverse scapular ligament causing neuropathy

Two patients, members of the same family, were found to have entrapment of the suprascapular nerve from a calcified superior transverse scapular ligament. The chief complaint in both cases was pain and weakness and atrophy of the supraspinatus and infraspinatus muscles. The nerve entrapment was confirmed by electromyographic studies and required surgical decompression to relieve the symptoms in both patients. Release of the entrapped nerve resulted in complete pain relief and full return of strength at 1-year followup.

Use of vertebral levels to measure presumed internal rotation at the shoulder: a radiographic analysis

Internal rotation of the shoulder is frequently measured by noting the maximal vertebral level reached by the patient's thumb, but it is not at all certain that this maneuver is strictly measuring internal rotation. We analyzed this maneuver with computed tomographic scans of the shoulder in differing positions. We also analyzed extension of the glenohumeral joint and scapulothoracic articulation with scapular lateral radiographs. Finally, we used posteroanterior radiographs to analyze elbow flexion at the limits of internal rotation behind the back. We found that maximal internal rotation behind the back occurs in approximately a 2 : 1 ratio between the glenohumeral joint and the scapulothoracic articulation. However, the scapulothoracic articulation was more significant in placing the arm behind the back, whereas the glenohumeral joint performed most of the internal rotation in front of the body. The scapulothoracic articulation assists in this motion by both extension and internal rotation of the scapula on the thorax. The limits of internal rotation behind the back are reached with a significant contribution from elbow flexion. We conclude that measuring shoulder internal rotation by the maximal vertebral level reached by the patient's thumb greatly oversimplifies the concept of internal rotation and that limitations in this motion may not be strictly due to a loss of internal rotation at the glenohumeral joint.

An assessment of the reliability of the Scoliometer

Accurate noninvasive measurements of spinal curvature are crucial in planning treatment and assessing curve progression in adolescent idiopathic scoliosis. An inter-rater agreement trial and an intrarater agreement trial were undertaken to estimate the reliability of axial rotation measurement using the Scoliometer (Orthopedic Systems, Inc., Haywood, California). In the inter-rater trial, two orthopedic surgeons and two orthopedic surgery residents independently measured the thoracic and lumbar axial rotations of 22 patients with idiopathic scoliosis using the Scoliometer. In the intrarater, trial a single orthopedic surgeon measured the thoracic and lumbar axial rotations of 25 patients on four separate occasions with the Scoliometer. Inter-rater agreement using the Scoliometer to estimate the magnitude of the hump (in centimeters) in the thoracic and lumbar regions was poor (intraclass correlation coefficient, Rho = 0.57 and Rho = 0.76 for the thoracic and lumbar regions, respectively). Inter-rater agreement using the Scoliometer to estimate the degree of axial trunk rotation was better (Rho = 0.81 and Rho = 0.82 for the thoracic and lumbar regions, respectively). Intrarater agreement using this device to estimate the magnitude of the hump (in centimeters) in the thoracic and lumbar regions was good (Rho = 0.90 and Rho = 0.84 for the thoracic and lumbar regions, respectively). Intrarater agreement using the Scoliometer to estimate the degrees of curvature was outstanding (Rho = 0.995 and Rho = 0.998 for the thoracic and lumbar regions, respectively). These results indicate that the Scoliometer can be a reliable noninvasive method for repetitively assessing spinal axial rotation when used by a single trained observer.

Rupture of the posterior tibial tendon associated with closed ankle fracture

Rupture of the posterior tibial tendon has rarely been associated with closed ankle fractures. All previous cases have been in association with pronation-external rotation type fractures in which the medial malleolus has been fractured. This case represents the first such report of a severed posterior tibial tendon in the absence of a medial malleolar fracture and reemphasizes the importance of critically evaluating intraoperative radiographs following the open reduction and internal fixation of closed ankle fractures to assess the possibility of soft tissue interposition. In the event of an acute rupture of the posterior tibial tendon, the authors recommend primary tendon repair.

Partial tears of the anterior cruciate ligament. Progression to complete ligament deficiency

In a prospective seven-year study, we treated 32 patients with partial ruptures of the anterior cruciate ligament (ACL) verified by arthroscopy. Twelve knees (38%) progressed to complete ACL deficiency with positive pivot shift tests and increased anteroposterior translation on tests with the KT-1000 arthrometer. Patients with partial ACL tears frequently had limitation for strenuous sports, while those developing ACL deficiency had additional functional limitations involving recreational activities. Three factors were statistically significant in predicting which partial tears would develop complete ACL deficiency: the amount of ligament tearing--one-fourth tears infrequently progressed, one-half tears progressed in 50% and three-fourth tears in 86%; a subtle increase in initial anterior translation; and the occurrence of a subsequent re-injury with giving-way.