bluuebunny/crossref_metadata_2025 huggingface dataset:
An organ culture model for assaying wound repair of the fibrocartilaginous knee joint meniscus
Authors: Webber Richard J. , York J. Lyndal , Vanderschilden John L. , Hough Aubrey J.
Published: June 2007

We describe an in vitro organ culture system that can be used to test the effect of various substances and compounds on the wound healing process in the fibro cartilaginous substance of the knee joint meniscus. Using culture medium containing either 10% fetal bo vine serum (FBS) or our recently developed serum-free, defined culture medium (DM), we have demonstrated the ability of meniscal fibrochondrocytes from intact rabbit menisci to extricate themselves from their sur rounding matrix and migrate into an exogenous, purified fibrin clot in vitro. After 4 weeks of culture in FBS containing medium, the cells which had invaded the clot had initiated the early aspects of a typical reparative response; the same response did not occur in DM alone. Morphologically, the cells on the surface of the clot resembled the original superficial fibrochondro cytes, whereas those cells within the substance of the clot more closely resembled the original deep fibro chondrocytes. After 10 weeks, the reparative response had progressed only to a certain point and then failed to progress further under these culture conditions. However, use of this culture system should now make it possible to rapidly identify and quantitate those fac tors which would most likely be useful in continuing the reparative response and in affecting meniscal wound repair. Elucidation of the mechanisms and requirements for meniscal healing will eventually allow the practicing orthopaedic surgeon to effect in situ meniscal repair and obviate the need for meniscectomy and its morbid sequelae.
Thigh musculature in relation to chronic anterior cruciate ligament tear: Muscle size, morphology, and mechanical output before reconstruction
Authors: Lorentzon Ronny , Elmqvist Lars-Gunnar , Sjostrom Michael , Fagerlund Markku , Fugl-Meyer Axel R.
Published: June 2007

Eighteen male patients who had untreated chronic ACL rupture were studied in order to evaluate thigh muscle size, morphology, and isokinetic performance of the quadriceps muscle. Computed tomography disclosed a 5.1 % mean atrophy of the quadriceps (P < 0.05), 2.1% slight hypertrophy of the hamstrings (P > 0.05), and also nonsignificant changes of all other muscle areas of the injured thigh. Muscle morphology (m. vastus lateralis) was normal in 11 biopsy specimens, whereas minor abnormalities (irregular shape or hypotrophy) could be seen in the rest. Isokinetic mechanical output of the knee extensors was 71% to 87% of that of the noninjured limb (P < 0.01), and the mechanical output corrected for differences in quadriceps cross-sectional area was significantly lower in the injured than the uninjured limb. As there were no significant correlations between isokinetic performance and muscle size or qualitative morphology or morphometric data, the strength decrease cannot be explained by muscle atro phy or structural changes per se. We conclude that nonoptimal activation of the muscles during voluntary contractions is probably the most important causative mechanism of the strength decrease found in patients who have chronic symptomatic ACL tear.
Diagnostic and operative arthroscopy of the knee under local anesthesia with parenteral medication
Authors: Martin Robert C. , Brown David E. , Zell Brian K. , Lichtman David M.
Published: June 2007

Arthroscopy of the knee under local anesthesia was performed on 102 patients for operative and diagnostic purposes between January and December of 1985. The procedures were performed on a same day basis without a pneumatic tourniquet. The operative record of each patient was reviewed to determine postopera tive diagnosis and treatment. The data was matched to a patient questionnaire that measured individual reaction to local anesthesia. The effectiveness and level of patient acceptance of this anesthetic technique for operative arthroscopy was then evaluated.

Ninety-one patients responded to the questionnaire, 82 of whom had prior anesthetic experience. Ninety- five percent of the patients had minimal or no discomfort during the procedure. Eighty percent indicated a pref erence for local anesthesia in the event of subsequent arthroscopy. No complications relating to the anesthetic agent were noted.

Arthroscopy of the knee under local anesthesia for routine operative arthroscopy was found to be safe, reliable, practical, and to have a high patient acceptance rate.
Carbon fiber as a prosthetic anterior cruciate ligament
Authors: Mäkisalo S. , Paavolainen P. , Holmström T. , Skutnabb K.
Published: June 2007

Connective tissue ingrowth into a carbon fiber prosthe sis inserted as a substitute for the ACL was biochemi cally quantified in an experimental pig model with a followup of 16 weeks. During this time, the net collagen amount expressed as hydroxyproline increased to only half that of the normal control ligament. Histological studies revealed relatively few fibroblasts capable of producing collagen inside the alloplastic ligament.

When these results are considered in conjunction with those of our earlier report of the disappointing mechanical strength of the carbon fiber substitutes, it seems evident that carbon fiber is not a suitable re placement for the ACL, mainly because of its failure to produce a "neoligament" before it disintegrates.
Three-dimensional dynamic motion analysis of the anterior cruciate ligament deficient knee joint
Authors: Reuben Jeffrey D. , Rovick Joshua S. , Schrager Robert J. , Walker Peter S. , Boland Arthur L.
Published: June 2007

Dynamic three-dimensional motion analyses of 15 fresh human knee joints subjected to combinations of flexion velocity and moment, internal and external femoral torque, and horizontal shear before and after sectioning the ACL were performed. ACL deficient specimens demonstrated marked anterior instability without rota tional instability. The pivot shift phenomenon occurred with an isolated ACL deficiency and was the result of anterior instability. The pivot shift was accentuated by external femoral torque, decreased by internal femoral torque, and was present in the absence of any applied torque. The pivot shift produced a sudden directional change in the motion of both femoral condyles and may be responsible for the meniscal degeneration that ac companies chronic ACL deficiency.
Passive tension of the ankle before and after stretching
Authors: Toft Egon , Espersen Geert T. , Kålund Søren , Sinkjær Thomas , Hornemann Birte C.
Published: June 2007

The passive tension resulting from dorsiflexion of the ankle was measured in relation to stretching in six handball players and six soccer players. Corresponding values of ankle angle and passive tension were meas ured by a strain gauge and a potentiometer connected to a pedal system.

The passive tension versus ankle angle was meas ured before and 90 minutes after a single contract- relax stretching program of the plantar flexors. Stretch ing lowered the passive tension by up to 18%. Contract- relax stretching performed twice a day for 3 weeks lowered the passive tension in the plantar flexors by up to 36%. Before the last measurements, no stretching was performed for 20 hours or more. Stretching thus had both a short-term effect, matching the length of a training session, and a long-term effect, shown in a reduction of passive tension after 3 weeks. The relative decrease in passive tension after stretching exercises was constant from a neutral position of the ankle to maximal dorsiflexion.

There was no correlation between 1) flexibility and the short-term effect of stretching, 2) flexibility and the long-term effect of stretching, or 3) the short-term and long-term effects of stretching. This indicates that pas sive tension was decreased in all subjects irrespective of their flexibility, and that subjects who had short-term effects after stretching did not necessarily demonstrate a long-term effect.
Arthroscopic shoulder capsulorraphy: Does it work?
Authors: Gross R. Michael
Published: June 2007

The purpose of this project was to answer the question, "Can shoulder instability be dealt with safely and effec tively arthroscopically?" This study, which began in December 1982 and concluded in February 1985, in volved 12 patients, 3 females and 9 males whose ages ranged from 14 to 40 years. Followup ranged from 31 to 63 months, the average being 44.8 months. The arthroscopic procedure was based on the use of a tool designed to capture the capsule, thus allowing place ment of either one or two low profile extraarticular staples in the capsule.

Two cases were failures. The remaining 10 patients were pleased with their operation. Based on the clas sification of Rowe et al., functional results were six excellent, two good, two fair, and two poor. The six patients with excellent results had shoulders of normal appearance. They were fully active and had neither pain nor limitation of motion. All six patients had negative apprehension signs. The two patients with good results had similar outcomes, but they had occasional morning stiffness and intermittent mild pain, as well as a 10° limitation of external rotation in both adduction and abduction. One patient who had a fair result had a positive apprehension sign and occasional pain with quick motion. The other patient with a fair result was hampered by more significant pain on an intermittent basis, yet the pain was not a constant issue. None of these patients had radiographic evidence of increased degenerative changes of the shoulder or staple migra tion. There were two complications and two failures.

The answer to the question, "Can shoulder instability be dealt with safely and effectively arthroscopically?", is a qualified yes. For patients who want to avoid the morbidity of an open operation, the results of study suggest that arthroscopic shoulder stabilization can be a safe and reasonably effective alternative to open surgery.
Noninvasive diagnosis of cruciate ligament damage with particular reference to computed tomography with arthrography
Authors: Büttner-Janz Karin , Schellnack Kurt , Rieder Thomas
Published: June 2007

Computed tomography (CT) with arthrography, a method not requiring anesthesia, has worked well in cruciate ligament damage diagnosis, particularly in the detection of PCL damage and in differentiation between ACL and PCL lesions. Evidence has been produced of its superior accuracy by comparison, in the study of 40 patients, among clinical findings, findings obtained from initial radiography, and diagnostic data produced by CT alone. Reference is also made to false interpretations in the context of clinical examination and CT.
A system for grading articular cartilage lesions at arthroscopy
Authors: Noyes Frank R. , Stabler Craig L.
Published: June 2007

Although there are several different classification sys tems for the description of articular cartilage damage, each has certain limitations and deficiencies which can lead to confusion. We are proposing a new system which describes articular cartilage abnormalities in sim ple terms. It is based on four separate and distinct variables: the description of the articular surface, the extent (depth) of involvement, the diameter of the le sion, and the location of the lesion. Although somewhat qualitative and subjective, the system enables the sur geon to record observed articular cartilage changes. We have used this grading as part of our overall knee rating system and have found it helpful in comparing treatment results between our different studies. For research purposes, a point scaling system facilitates computerization and statistical analysis of the data.
The forces in a knee brace as a function of hinge design and placement
Authors: Regalbuto M.A. , Rovick J.S. , Walker P.S.
Published: June 2007

Customized knee braces for three normal subjects were instrumented to monitor the forces and moments across the hinges as the subjects performed various activities. The forces and moments were taken to rep resent a mismatch between actual knee motion and the motion the brace sought to impose. The different hinge designs studied were fixed axis, gear-on-gear, rack- and-pinion, and natural 3-D; they showed only moder ate differences in forces. Much larger differences were seen if the hinges were offset 12 mm from the ideal placement. Posterior placement resulted in the least force and anterior placement the highest.

The mismatch of knee motion to brace motion would probably lead to abnormal ligament lengths and ten sions and other internal mechanical changes, as well as to pistoning and discomfort. The results of this study have implications on brace design, selection, and place ment.
Tarsal Coalition
Authors: O'Neill Daniel B. , Micheli Lyle J.
Published: June 2007

A retrospective review was undertaken of 16 adoles cent patients (20 feet) with tarsal coalitions. All patients were active in sports and were seen in the Sports Medicine Clinic. Ages ranged from 9 to 17 years (av erage, 13 years). Failing conservative therapy, 18 feet had resection of the tarsal bar; 1 patient (2 feet) had bilateral extraarticular subtalar arthrodeses. The pa tients were seen in followup an average of 5.1 years postoperatively (range, 2 to 10 years).

An objective ankle/foot score was developed and all patients improved their score postoperatively, with the average score being improved 25%. Nineteen of 20 feet (95%) had excellent or good postoperative results by the ankle/foot score, while 17 of 20 (85%) had an excellent or good subjective result.

Two bars in two feet (10%), both in the same patient, recurred. There were six patients with preoperative talar beaking, and all had an excellent or good follow up result. All males returned to their previous level of competition in sports, while three female patients (three feet) gave up sports.

Resection of tarsal coalitions, even in the presence of talar beaking without other degenerative changes, yields consistently good follow-up results.
Chronic anterolateral instability of the knee
Authors: Karrholm Johan , Elmqvist Lars-Gunnar , Selvik Göran , Hansson Lars Ingvar
Published: June 2007

The rotatory stability of the knee was investigated in 20 patients with a previous tear of the ACL. The three- dimensional movements of the tibia during the testing procedure were registered using roentgen stereopho togrammetric analysis. Changes of the tibial move ments between an intermediate, an anterior, or a pos terior tibial position were registered using tibial tractions in combination with a simultaneous external or internal rotatory torque.

At 20° of flexion the internal rotatory laxity was increased on the injured side. The external rotatory laxity did not significantly differ between the two sides. With anterior traction, the internal rotatory laxity in creased on both the injured and the normal sides and became almost equal. The external rotatory laxity man ifested a decrease which was most pronounced on the injured side. With posterior traction, the rotatory laxities decreased and did not significantly differ between the two sides. Analysis of the simultaneously occurring translations of the tibial plateau disclosed abnormal displacements of both the medial and the lateral tibial condyles on the injured side.
The results of conservative management of juvenile osteochondritis dissecans using joint scintigraphy
Authors: Cahill Bernard R. , Phillips Mark R. , Navarro Ronald
Published: June 2007

A prospective clinical study used joint scintigraphy to investigate conservative treatment of juvenile osteo chondritis dissecans (JOCD) of the femoral condyle. The predictive value of scintigraphic evaluation and various parameters (age at onset, sex, location and size of lesion) were analyzed. Over a 10 year period, the senior author followed 92 knees in 76 patients, 60 of whom were male and 16 female (11 and 5 bilaterals, respectively). All patients were participants in athletics or exercise programs.

All patients had orthopaedic assessment, roentgen ographic studies (AP, lateral, and tunnel views), 99m- Technetium phosphate compound joint scintigraphy, and instruction in a symptom-free existence (with all athletic activity proscribed). Patients were reevaluated and scanned every 8 weeks. No casts or braces were used, although crutches were sometimes necessary to maintain symptom-free levels.

Based on specific indications for failure of conserva tive treatment, 50% of these patients failed and under went surgery. Of the 92 knees, 52 were successfully treated conservatively, while 40 failed. Average fol lowup was 4.2 years. Average age at onset was 12.5 years; the success group averaged 12.1 years and the failure group 13.0 years. The average lesion size was 363.2 mm2, with 309.5 mm2 in the success group and 436.0 mm2 in the failure group. Parameters of location, sex, and scan classification were not statistically signif icant as predictive factors.
Evaluation of arthrography and arthroscopy for lesions of the posteromedial corner of the knee
Authors: Kimori K. , Suzu F. , Yamashita F. , Sakakida K. , Hirasawa Y.
Published: June 2007

Injuries of the posteromedial corner of the knee joint were evaluated using the results of clinical, arthro graphic, and arthroscopic examinations in 137 sur gically treated patients (137 knees) with injuries of the ACL (acute in 61, chronic in 76). The accuracy of each diagnosis was confirmed by determining the site of the injury during the arthrotomy.

A tear of the posteromedial corner of the medial meniscus was present in 40 patients, and an accurate diagnosis was made in 29 patients by clinical exami nation, in all 40 patients by arthrography, and in 38 patients by arthroscopy.

Injury of the posterior oblique ligament was noted in 37 patients, and an accurate diagnosis was made in 15 patients by clinical examination, in 35 patients by ar thrography, and in 8 patients by arthroscopy. Lesions of the posterior oblique ligament which were not de tected in the arthroscopic examination alone were either rupture at the attachment to the femur or longi tudinal tears in the meniscofemoral or meniscotibial portion.

The results revealed that arthrography is an important means of evaluation in the diagnosis of injuries of the posteromedial corner of the knee joint.
Surgical treatment of the iliotibial band friction syndrome
Authors: Martens M. , Libbrecht P. , Burssens A.
Published: June 2007

A selected group of 23 patients underwent surgery for iliotibial band friction syndrome. Among the patients presenting with this exertional pain syndrome were runners, football players, and cyclists. Diagnosis was clinical since radiographs were negative and an ultra sound examination was positive in only one case, show ing an aberrant picture around the lateral femoral epi condyle. Although conservative treatment is effective in most cases, an alternative is needed for patients with complaints that are resistant to conservative means. Surgery was done with the knee held in 60° of flexion and consisted of a limited resection of a small triangular piece at the posterior part of the iliotibial band covering the lateral femoral epicondyle. The uniform good re sults, low morbidity, and quick return to sports dem onstrate that this type of surgery offers a solution for selected cases of failed prolonged conservative treat ment.
Acute brachial neuropathy in athletes
Authors: Hershman Elliott B. , Wilbourn Asa J. , Bergfeld John A.
Published: June 2007

Acute brachial neuropathy is an uncommon etiology of shoulder pain and disability. It can, however, present in association with athletic activity and therefore must be included in the differential diagnosis of athletes with such symptomatology. Findings that should alert the examiner to the possible presence of acute brachial neuropathy include 1) onset with noncontact as well as contact sports, 2) rather acute onset of pain without specific inciting trauma, 3) persistent, often severe pain that continues despite rest, 4) patchy brachial plexus and/or peripheral nerve involvement, and, 5) dominant arm predominance of symptoms and signs.

Electromyography and nerve conduction studies often can confirm the diagnosis. Treatment begins with rest and continues through a rehabilitation phase. Fol lowup of athletes with acute brachial neuropathy dis closes that weakness may persist in the affected mus cles. Absolute strength parity may be difficult to achieve, so permission to participate in athletics must be given on a case by case basis.
Overuse injuries in triathletes
Authors: Collins Kathryn , Wagner Mark , Peterson Keith , Storey Mitchel
Published: June 2007

A questionnaire was mailed to 600 of 657 finishers in the Seafair Triathlon (July 20, 1986); 45% of those polled returned the questionnaire. Over the preceding year, 49% of the respondents suffered a training-re lated injury serious enough to cause them to stop training for at least 1 day, seek medical care, or take medicine. Seventy percent of the injuries were due solely or partly to running. The knee, shoulder, and ankle were most frequently affected. Female triathletes and those more than 40 years of age showed a similar injury incidence and distribution. Elite triathletes aver aged more miles per week in each sport than the athletes as a whole and showed a higher incidence of injury (60%), although this was not a significant differ ence. Higher weekly swimming, cycling, and running mileages did not lead to a higher incidence of injury. The likelihood of injury was independent of age, sex, body mass index, mileage per week, or other training factors evaluated in the study.
High school football injuries: A prospective study and pitfalls of data collection
Authors: Prager Bruce I. , Fitton Walter L. , Cahill Bernard R. , Olson George H.
Published: June 2007

A 4 year prospective study (1982 to 1985) of high school varsity football injuries from the four Peoria high school football teams was undertaken. Two hundred fifty-one injuries were recorded among a player popu lation of 598, resulting in an injury rate of 42.1 % per 100 players. All of the players followed a prescribed preseason summer conditioning program that was en dorsed by the Illinois High School Athletic Association.

The injuries were recorded on an athletic injury profile and entered into a computer for data analysis and retrieval. The injury distribution by player position showed that halfbacks, tackles, linebackers, and guards had a higher risk of injury than other positions. The knee was the body part injured most frequently (20.3%). A matrix of injuries to halfbacks was set up to examine the relationship of body part injured to type of play, time of injury, and activity during injury. An an thropometric study using the Quetelet index did not reveal any correlation between injury and body size when the injured players were compared with the non- injured players. Experience since 1969 has taught us many of the errors and pitfalls involved in injury sur veillance. Strict adherence to recording of data will ensure an accurate and useful injury surveillance pro gram.
Posteromedial pain in the lower leg
Authors: Melberg Per-Erik , Styf Jorma
Published: June 2007

Intramuscular pressure was recorded in 28 patients with exercise-induced posteromedial pain in the lower leg. Pressure was recorded simultaneously in the pos terior tibial muscle and in the flexor digitorum muscle during an exercise test and at rest after exercise. This study shows that intramuscular pressures during ex ercise and the time period for normalization of the pressure at rest after exercise were within normal limits. The result of pressure recording depends on which muscle in the deep posterior compartment is investi gated and on the type of work performed. This article describes some of the difficulties associated with pres sure recording in the deep posterior compartment. Chronic compartment syndrome in the deep posterior compartment as a reason for pain in the posteromedial part of the lower leg could not be demonstrated.
Snowboard injuries
Authors: Pino Edward C. , Colville Mark R.
Published: June 2007

A retrospective survey of 267 snowboarders was un dertaken to determine the population at risk and types and mechanisms of injuries sustained in this sport. Snowboarders are young (average age, 21 years), male (>90%), view themselves in average or above average physical condition (96%), and have varied sports inter ests. One hundred ten injuries that resulted in a physi cian visit were reported. Ligament sprains, fractures, and contusions were the most frequent types of injury. Fifty percent of all injuries occurred in the lower extrem ities, with ankle injuries being the most common. Snow board riders using equipment with increased ankle sup port seem to be more protected from lower extremity injuries. The lower extremity injuries were concentrated in the forward limb of the snowboarder, where the rider's weight is disproportionately distributed. Differ ences in the mechanism and spectrum of injury be tween snowboarding and skiing injuries were noted, including: impact rather than torsion as the major mech anism of injury, a significant lack of thumb injuries, comparative increase in ankle injuries, a decrease in knee injuries, and a higher percentage of upper extrem ity injuries.
Open meniscus repair
Authors: DeHaven Kenneth E. , Black Kevin P. , Griffiths Henry J.
Published: June 2007

An average 4.6 year follow-up study has been done on 80 of 104 open meniscus repairs of unstable peripheral tears. Two of nine retears were treated in the acute stage and seven were treated in the chronic stage. Eight retears were medial, one was lateral (repair ratio, 1.5:1 medial to lateral), three occurred through the repair site, and six occurred in different areas. Retears occurred in 1 of 26 isolated repairs, 2 of 38 repairs done with an ACL stabilization procedure, and 6 of 16 repairs done in ACL deficient knees that were not stabilized. Standing radiographs revealed normal com partments in 40 of 41 repairs.
Epidemiology and traumatology of injuries in soccer
Authors: Nielsen Allan Buhl , Yde Johannes
Published: June 2007

A prospective investigation of soccer injuries among 123 players participating at various competition levels was undertaken in a Danish soccer club. The injury incidence during games was highest at division level (18.5/1000 hours) and lowest at series level (11.9/1000 hours), whereas the distribution of the incidences dur ing practice was reversed. The youth section (16 to 18 years) had incidences that could be compared to the highest senior level. The lower extremity was involved in 84% of the injuries, including 34% of overuse injuries. Ankle sprains were most common (36%) and equally found at all levels, whereas half of all overuse injuries were seen among division players. Contact injuries during tackling occurred most often in lower series and youths (45%). Players participating at high levels had only 30% of the injuries during tackling and 54% during running. More than half of 20 knee injuries were caused by tackling. Thirty-five percent of injured players were absent from soccer for more than 1 month; 28% had complaints 12 months after the end of the season with knee injuries the most serious.

The study shows that the injury incidence, the pattern of injury, and the traumatology varied between players participating at different levels of soccer competition.
Variability and reliability of joint measurements
Authors: Bovens Alphons M.P.M. , van Baak Marleen A. , Vrencken Joseph G.P.M. , Wijnen Joseph A.G. , Verstappen Frans T.J.
Published: June 2007

The purpose of this study was to determine the varia bility and reliability of joint measurements as carried out by three physician observers. The intratester variation and reliability of nine different joint measurements was determined in eight healthy subjects. The measure ments were taken in eight sessions by each tester. In this population also the intertester variation and relia bility was determined by the three observers. This was also done in a population of middle-aged athletes over a period of 2.5 years.

The results indicate that it is difficult to show either an improvement or worsening of a joint motion of less than 5° to 10° for most joints measured by the same tester. The intertester variation is not consistent over a longer period of time, so differences between observers during long-term studies cannot be corrected on the basis of a single study at a single point in time. The reliability of all nine joint measurements is not very high, but is probably sufficient if the results are used to compare groups within a single population and for large studies with experienced observers. Because the reli ability strongly depends on the interindividual variation, it is preferable to determine the reliability for each study population.
Ultrasound catheter placement for deep posterior compartment pressure measurements in chronic compartment syndrome
Authors: Wiley J. Preston , Short W. Bruce , Wiseman David A. , Miller Stephen D.
Published: June 2007

Medial shin pain, often referred to as shin splints, is a common but difficult to diagnose entity in many ath letes. Chronic deep posterior compartment syndrome as a cause of medial leg pain is still controversial. The problems of deep posterior compartment pressure measurement contribute to this controversy. These problems include safety of catheter insertion and the possibility that the patient has more than one deep posterior compartment. In this paper, we present a new technique for catheter placement in which continuous ultrasound guidance is used. This technique allows for the safe placement of the catheter into the deep pos terior compartment and for documentation of catheter tip location.
Suprascapular neuropathy in pitchers
Authors: Ringel Steven P. , Treihaft Marc , Carr Michael , Fisher Richard , Jacobs Paul
Published: June 2007

The clinical features and preoperative and postopera tive electrodiagnostic studies were reviewed in two professional pitchers with a suprascapular neuropathy. These studies demonstrate that denervation of the infraspinatus and/or supraspinatus muscle is not al ways due to entrapment of the nerve at the suprascap ular or spinoglenoid notches, as is often proposed. Similar studies in healthy pitchers during spring training and again at midseason demonstrate that slowing of suprascapular nerve conduction is detectable in some cases as the season progresses.

Sagittal sections of a cadaver with the arm fixed in the acceleration phase of the pitching motion demon strate five possible sites of trauma to the suprascapular nerve. Mechanisms proposed to explain these progres sive, but potentially reversible, changes include consid eration of biomechanical factors as well as anatomical features. An alternative hypothesis to nerve trauma that explains this symptom complex is intimal damage to the axillary or suprascapular artery and subsequent production of microemboli which become trapped in the suprascapular nerve vasa nervorum.
Isokinetic evaluation of shoulder rotational strength between the plane of scapula and the frontal plane
Authors: Greenfield Bruce H. , Donatelli Robert , Wooden Michael J. , Wilkes Joseph
Published: June 2007

The purpose of this study was to determine whether shoulder rotational strength was greater in the plane of the scapula or the frontal plane.

Isokinetic shoulder rotational strength was evaluated in 20 subjects. Using the Merac (Universal Gym Equip ment, Inc., Cedar Rapids, IA), test data was gathered in the right shoulders, in 45° abduction, at a speed of 60 deg/sec, in the plane of the scapula and the frontal plane. Each subject returned within 1 week for retests to establish reliability. The average correlational coeffi cient across tests was 0.87. The Merac computer system was used to analyze data. Mean and standard deviations for peak torque to body weight were calcu lated. A paired t-test was used to examine the differ ence in the means for internal and external rotation between the two positions. The results indicated no significant difference between the two positions for shoulder internal rotational strength values. However, shoulder external rotational strength values in the plane of the scapula were statistically significantly higher than in the frontal plane ( P < 0.001). These preliminary results suggest isokinetic strength training and testing may be preferable in the plane of the scapula rather than the frontal plane.
The inside-out Bankart procedure
Authors: Berg Eugene E. , Ellison Arthur E.
Published: June 2007

Bankart capsulorraphy for recurrent shoulder instability produces predictable results. Time-consuming, techni cally demanding details of the procedure, however, discourage its use. A simplified technique and new instrumentation solving these limitations was used in 69 procedures, all performed by the same surgeon. Seventy-eight percent of these procedures were re viewed independently at a minimum of 2 years followup: 77% were asymptomatic, 12% had minimal symptoms, and 11 % had residual problems. Instability recurred in six patients and was associated with a significant trau matic event in five. Thus, the inside-out Bankart modi fications were effective.
Electromyographic analysis of the shoulder during the golf swing
Authors: Pink Marilyn , Jobe Frank W. , Perry Jacquelin
Published: June 2007

Golf is a popular sport throughout the world, yet there is little in the literature that discusses the mechanics of the swing. The purpose of this study is to analyze the EMG activity in eight shoulder muscles of both the right and left arms during the golf swing. The results reveal that the infraspinatus and supraspinatus act predomi nantly at the extremes of shoulder range of motion, the subscapularis and pectoralis major during acceleration, the latissimus dorsi during forward swing, and the anterior deltoid during forward swing and follow- through. The middle and posterior deltoids appear to be relatively noncontributory, without any specific tim ing patterns. This data is an expansion of an earlier pilot study and allows us to more accurately develop an exercise program for optimal performance as well as for prevention and rehabilitation.
The inappropriateness of helmet drop tests in assessing neck protection in head-first impacts
Authors: Bishop P.J. , Wells R.P.
Published: June 2007

Protecting the cervical spine in situations of axial com pressive loading is indeed complex. Results from a number of crash simulations suggest that the mecha nisms of head impact causing brain damage and those causing neck injury are different. The idea that neck injuries can be predicted from results of helmet drop tests or that the helmet is capable of providing protec tion to the cervical spine is unsupported.

In head-first collisions causing axial compressive loading, the cushioning properties of the helmet alone would dictate the maximum force on the neck if both the head and neck were rigid. Since the head and neck are not rigid and appear to be as stiff or less stiff than the helmet, the cushioning influence of the helmet is minimized, so the forces experienced by the neck are dictated largely by its own properties. The helmet does not have a large influence. To be effective, the helmet would have to be much less stiff than it is at present and would have to maintain this low stiffness under very large loads. These conditions would be difficult to achieve without making the helmet disproportionately larger than it is now.
Magnetic resonance imaging of the glenoid labrum
Authors: Gross Michael L. , Seeger Leanne L. , Smith Jeffrey B. , Mandelbaum Bert R. , Finerman Gerald A.M.
Published: June 2007

Shoulder complaints are common in the athletic popu lation. Successful treatment is dependent upon the ability to correctly identify the pathologic changes as sociated with a specific disorder and arrive at an ac curate diagnosis. Labral abnormalities are traditionally associated with glenohumeral instability. Isolated labral tears or degenerative changes may also cause shoulder dysfunction. A reliable clinical tool to assess the status of the labrum would be useful for diagnosis and man agement of shoulder disorders.

The magnetic resonance images of 48 shoulders that had subsequent surgical examination of their labra were reviewed with respect to labral appearance. Labra ap pearing as abnormal were further classified as torn, degenerative, or eroded. Surgical examination was used as the reference standard. Magnetic resonance imaging demonstrated high levels of sensitivity, speci ficity, positive and negative predictive values, and ac curacy for evaluation of the glenoid labrum. Magnetic resonance imaging is a reliable and accurate method for depicting the status of the glenoid labrum. Magnetic resonance imaging appearance of the labrum may as sist the clinician in distinguishing the varying forms of shoulder dysfunction and facilitate diagnosis and effec tive treatment.
Collagen biosynthesis in rabbit intraarticular patellar tendon transplants
Authors: Fulkerson John P. , Berke Adrienne , Parthasarathy Narayanan
Published: June 2007

Autogenous patellar tendon grafts were transplanted into the knees of 40 New Zealand White adult rabbits. Grafts were subsequently analyzed for rate of collagen synthesis, collagen content, collagen type, histologic change, and cyanogen bromide cleavage patterns of collagen to closely assess the nature of collagen in tendon grafts up to 2 years from the time of transplan tation. Tendon grafts were placed in rabbit knees as free fragments or were attached to synovium.

These studies show that tendon grafts, even without vascularization or stress, remain viable after intraartic ular transfer. Vascularization produces a trend toward increased collagen synthesis, but statistical analysis suggests that control levels of collagen synthesis con tinue after tendon transfers into rabbit knees. Cyanogen bromide cleavage peptides showed appropriate colla gen formed by unstressed autogenous tendon trans plants removed from rabbit knees up to 2 years from transplantation. All tendon grafts degenerated initially, but began to form histologically healthy looking con nective tissue by 18 to 24 weeks after transplantation. Overall, the results are encouraging with regard to the fate of intraarticular tendon grafts.
Selected kinematic characteristics of intercollegiate women triple jumpers
Authors: Al-Kilani Maher A. , Widule Carol J.
Published: June 2007

Eight women triple jump finalists at the 1986 Big Ten Track and Field Championships and 10 women triple jump finalists at the 1986 National Track and Field Competition were filmed during competition. Among selected kinematic characteristics, the following high correlations ( r > 0.70) were found: the distance of the hop phase correlated highly with the total jump dis tance ; the horizontal position of the center of gravity of the body in relation to the support foot at takeoff correlated highly with the distance of the hop and the jump phases; the horizontal velocity into the step phase correlated highly with the total distance of the jump; the vertical velocity into the hop and step phases cor related highly with the respective phase distance; and there was an inverse correlation between the maximum height of the center of gravity during the flight phase of the step and the total distance. A significant difference was found between men and women triple jumpers in relation to the contribution of the step phase to the total distance of the jump (men, X = 29.5, SD = 1.46; women, X = 26.7, SD = 2.94; P < 0.05). All remaining relationships among the kinematic variables studied were found to be not significant at P < 0.05 or were less than r = 0.70. The phase ratios of current women triple jumpers were similar to ratios that have been reported for the novice athlete.
Relationship of turnout to hip abduction in professional ballet dancers
Authors: Kushner S. , Saboe L. , Reid D. , Penrose T. , Grace M.
Published: June 2007

The ability to externally rotate or turn out the hip is fundamental to ballet. Every classical dancer aims to achieve perfect turnout. The purpose of this study was to determine how much turnout is necessary for maxi mal abduction. It was hypothesized that moderate turnout is sufficient for this purpose. Twenty-two professional dancers from the Alberta Ballet Company were studied. Measurements of passive hip abduction were taken at 0°, 45°, 60°, 70°, 80°, 90° and maximum hip lateral rotation using a goniometer and Leighton flexometer. Statistical analysis was done using Pearson correlation coefficients. A significant positive correlation was found between abduction and lateral rotation ( P < 0.05). The greater the position of external rotation, the more abduction achieved. In conclusion, the traditional emphasis on good turnout has some scientific merit and functional implications.
Viscoelastic properties of muscle-tendon units
Authors: Taylor Dean C. , Dalton James D. , Seaber Anthony V. , Garrett William E.
Published: June 2007

Most muscle stretching studies have focused on defin ing the biomechanical properties of isolated elements of the muscle-tendon unit or on comparing different stretching techniques. We developed an experimental model that was designed to evaluate clinically relevant biomechanical stretching properties in an entire muscle- tendon unit. Our objectives were to characterize the viscoelastic behavior of the muscle-tendon unit and to consider the clinical applications of these viscoelastic properties.

Rabbit extensor digitorum longus and tibialis anterior muscle-tendon units were evaluated using methods designed to simulate widely used stretching tech niques. Additionally, the effects of varying stretch rates and of reflex influences were evaluated. We found that muscle-tendon units respond viscoelastically to tensile loads. Reflex activity did not influence the biomechani cal characteristics of the muscle-tendon unit in this model.

Experimental techniques simulating cyclic stretching and static stretching resulted in sustained muscle-ten don unit elongations, suggesting that greater flexibility can result if these techniques are used in the clinical setting. With repetitive stretching, we found that after four stretches there was little alteration of the muscle- tendon unit, implying that a minimum number of stretches will lead to most of the elongation in repetitive stretching. Also, greater peak tensions and greater energy absorptions occurred at faster stretch rates, suggesting that the risk of injury in a stretching regimen may be related to the stretch rate, and not to the actual technique. All of these clinically important considera tions can be related to the viscoelastic characteristics of the muscle-tendon unit.
Diagnostic arthroscopy and longitudinal open lateral release
Authors: Dzioba Robert B.
Published: June 2007

The purpose of this study was as follows: 1) to review our previous findings regarding surgical outcome fol lowing open retinacular release but now at a mean followup of 4 years, 2) to test the validity of the correc tion of patellar "overhang" by Merchant views at 4 years and correlate this with outcome, 3) to correlate arthros copic findings of lateral overhang, patellofemoral carti lage disease, preoperative Q-angle measurements, and duration of symptoms with outcome at 4 years postre lease. The surgical technique of diagnostic arthroscopy and open longitudinal release has been described pre viously by the author, emphasizing the specific anatom ical structures to be divided. The synovium was never incised and the retinacular structures were freed to allow reduction of the patella medially. Sixty patients comprising 76 knees were reviewed at a mean followup of 4 years postrelease. Followup included evaluation of Merchant views and Q angles, physical examination, and determination of patient satisfaction. Eighty-five percent of the patients followed retained the good to excellent ratings they had at the 2 year followup. "Re duction" of the released patella on Merchant views correlated well with surgical outcome and patient sat isfaction in 95% of cases. Residual Merchant view patellar tilt or excessive lateral position correlated well with poor results. Hematoma formation was the leading cause of failure. A severe preoperative Q angle corre lated somewhat with results at 4 years but this was not statistically significant. The degree of articular cartilage disease at prerelease arthroscopy did not correlate at all with results at 4 years, nor did the duration of preoperative symptoms. "Good outcome" preoperative findings included biomechanical peripatellar pain, a pos itive patellar restriction/apprehension test, and a posi tive Merchant view. Intraoperative "good outcome" pre operative findings included a positive arthroscopic ov erhang sign, evidence of patellar maltracking, and an abnormal toughened lateral retinaculum. "Reduction" of the released patella on quadriceps films taken 6 weeks after surgery and rehabilitation remained un changed at 4 years, correlating exceedingly well with excellent clinical results.
Primary surgical treatment of anterior cruciate ligament ruptures
Authors: Kaplan Norman , Wickiewicz Thomas L. , Warren Russell F.
Published: June 2007

We reviewed 52 patients who underwent primary sur gical repair of their acutely injured ACL using a multiple loop, varying depth suture technique. The average fol lowup was 6 years and 10 months. Nine patients (17%) were considered as having failed repairs, with failure based on the presence of clinical instability (giving way) with sports participation and a positive Lachman test and/or pivot shift maneuver. In addition, of 26 patients in whom KT-1000 (MEDmetric Corp., San Diego, CA) measurements were performed, 42% were found to have abnormal laxity. Although using multiple sutures in primary repair of the anterior cruciate may work in some patients, it is an unpredictable operative proce dure and resulted in a 17% failure rate in our study.
Repeatability of the KT-1000 arthrometer in a normal population
Authors: Wroble Randall R. , Van Ginkel Laura A. , Grood Edward S. , Noyes Frank R. , Shaffer Brian L.
Published: June 2007

Despite its popularity, the MEDmetric KT-1000 arthro meter's reliability remains inadequately documented. We conducted this study to determine the magnitude of trial-to-trial (within installation), installation-to-instal lation (within day), and day-to-day (between day) vari ability of anterior/posterior translation measurements in normal knees.

We selected six normal subjects, three males and three females, and tested each on 6 consecutive days with three separate installations per day. We recorded the total anterior/posterior translation at ±89 and ±134 N force at 25° of flexion during three consecutive trials in a single installation.

Analysis of variance showed that no significant differ ence existed between trials (within installation) or be tween installations (within day) for all parameters. How ever, we did find a significant difference between days for individual right and left knee translation measure ments at 89 and 134 N force. More importantly, no significant difference existed between days for right to left differences at both force levels.

The magnitude of the expected measurement varia bility was expressed by computing 90% confidence limits for total anterior/posterior translation at ±89 N force. These were ±1.5 mm for the right knees, ±1.4 mm for the left knees, and ±1.6 mm for the right-left differences. Fischer's protected least significant differ ence post hoc test revealed that for all parameters, the 1 st day measurements were significantly less than those on following days, suggesting that patient and examiner adjust to the testing procedure.

We conclude that the standard KT-1000 evaluation should report paired differences rather than individual knee measurements. Additionally, initial evaluation should be supplemented by follow-up examinations for verifying translation values.