bluuebunny/crossref_metadata_2025 huggingface dataset:
Intrinsic and Extrinsic Risk Factors for Muscle Strains in Australian Football
Authors: Orchard John W.
Published: July 2017

Muscle strains are common injuries in Australian football and other sports involving sprinting. Between 1992 and 1999, 83,503 player-matches in the Australian Football League were analyzed for risk of muscle strain injuries using logistic regression analysis. There were 672 hamstring, 163 quadriceps, and 140 calf muscle strain injuries. All three types of muscle strains were associated with significant risk factors. For all injuries, the strongest risk factor was a recent history of that same injury and the next strongest risk factor was a past history of the same injury. History of one type of muscle strain increased the risk for certain types of other muscle strains. Age was a risk factor for hamstring and calf muscle strains (even when adjusted for injury history) but was not a risk factor for quadriceps muscle strains. Quadriceps muscle injuries were more common in shorter players and were more likely when there had been less rainfall at the match venue in the previous week. Quadriceps muscle injuries were significantly more common in the dominant kicking leg, whereas hamstring and calf muscle injuries showed no difference in frequency between the dominant and nondominant legs.
Biomechanical Behavior of the Plantar Flexor Muscle-Tendon Unit after an Achilles Tendon Rupture
Authors: Bressel Eadric , McNair Peter J.
Published: July 2017

The purpose of this study was to examine the biomechanical behavior of the plantar flexor muscle-tendon unit in subjects who had ruptured their Achilles tendon. Twenty-six men and 14 women volunteered for the study. Eighteen subjects had been treated operatively and 22, nonoperatively. All subjects had ruptured their Achilles tendon more than 1 year before the study, and 28 of the 40 ruptures occurred 5 years or less before the day of testing. A KinCom dynamometer was used to measure ankle joint angle, passive torque, and maximal isometric plantar flexor torque. During a 2-minute passive calf stretch, stiffness and torque relaxation were calculated. Isometric torque and peak passive torque were 17% and 10% greater for the uninvolved versus the involved limb, whereas stiffness and torque relaxation were not different between limbs. The time since injury did not influence the results, nor did the mode of initial treatment, that is, whether the subjects were treated operatively or nonoperatively. These findings suggest that changes in strength and peak passive torque may be chronic adaptations associated with Achilles tendon rupture.
Snowboarder's Talus Fracture
Authors: Boon Andrea J. , Smith Jay , Zobitz Mark E. , Amrami Kimberly M.
Published: July 2017

Fracture of the lateral process of the talus is an injury unique to snowboarders and is of particular clinical relevance because it masquerades as an anterolateral ankle sprain and is difficult to detect on standard radiographic views. Misdiagnosis can lead to long-term morbidity in a young and active population, with ensuing severe degeneration of the subtalar joint. To date, the precise mechanism of injury has not been established, making it difficult to identify potential preventive strategies in equipment design or snowboarding technique. Fracture of the lateral process of the talus in snowboarders has been thought to result from pure dorsiflexion and inversion combined with axial loading. We hypothesized, however, that external rotation is a key component of the mechanism of injury. Ten cadaveric ankles were mounted on a materials testing machine in a position of fixed dorsiflexion and inversion. All ankles were loaded to failure axially, with or without combined external rotation. No fractures occurred after axial loading in dorsiflexion and inversion, but six of eight specimens sustained fractures of the lateral process of the talus when similarly loaded with external rotation added, supporting our hypothesis. Further study is needed to evaluate the relationship between various types of snowboarding equipment and fracture mechanism.
Abnormally Decreased Regional Bone Density in Athletes with Medial Tibial Stress Syndrome
Authors: Magnusson Håkan I. , Westlin Nils E. , Nyqvist Fredrik , Gärdsell Per , Seeman Ego , Karlsson Magnus K.
Published: July 2017

Medial tibial stress syndrome, a common condition of uncertain origin found in athletes, is characterized by pain in the distal posteromedial aspect of the tibia during exercise, with or without increased scintigraphic uptake in the affected region. To determine whether medial tibial stress syndrome with increased scintigraphic uptake is associated with a change in tibial bone mineral density confined to the site of the increased uptake, we measured bone mineral density (in grams per square centimeter) in 18 adult male athletes with long-standing medial tibial stress syndrome and compared the measurements with those of 16 age-and sex-matched control subjects and with those of 18 athletes without medial tibial stress syndrome who had a comparable training regimen. Tibial bone mineral density in the region corresponding to the pain was 15% ± 9% lower in the patients than in control subjects and 23% ± 8% lower than in the athletic control subjects (both significant differences). Bone mineral densities in most other regions of the body were higher than in the control subjects but lower than in the athletic controls at the corresponding sites. In summary, medial tibial stress syndrome is associated with low regional bone mineral density.
The Relationship of the Femoral Origin of the Anterior Cruciate Ligament and the Distal Femoral Physeal Plate in the Skeletally Immature Knee
Authors: Behr Christopher T. , Potter Hollis G. , Paletta George A.
Published: July 2017

We defined the anatomic relationship of the anterior cruciate ligament femoral origin to the distal femoral physis in the skeletally immature knee with use of 12 fresh-frozen human fetal specimens (ages, 20 to 36 weeks). Each specimen underwent magnetic resonance imaging, was dissected free of soft tissue, sectioned in the sagittal plane, and stained. The spatial relationship of 1) the epiphyseal side of the physeal proliferative zone to the nearest point of bony attachment of the anterior cruciate ligament and 2) the origin of the anterior cruciate ligament to the over-the-top position were measured. The same measurements were made in 13 skeletally immature knees (ages, 5 to 15 years). We found that the femoral origin of the fetal anterior cruciate ligament developed as a confluence of ligament fibers with periosteum at 20 weeks, vascular invasion into the epiphysis at 24 weeks, and establishment of a secure epiphyseal attachment by 36 weeks. In the fetus, the distance from the anterior cruciate ligament femoral origin to the epiphysis was 2.66 ± 0.18 mm (range, 2.34 to 2.94). There was no significant change in this distance in adolescent specimens (2.92 ± 0.68 mm; range, 2.24 to 3.62). The over-the-top position was at the level of the distal femoral physis.
The Effect of Injury to the Posterolateral Structures of the Knee on Force in a Posterior Cruciate Ligament Graft
Authors: LaPrade Robert F. , Muench Carter , Wentorf Fred , Lewis Jack L.
Published: July 2017

To determine whether untreated grade 3 posterolateral knee injuries contribute to a significant increase in force on a posterior cruciate ligament reconstruction graft, we measured the force on the graft during joint loading of a posterior cruciate ligament-reconstructed knee with otherwise intact structures and then selectively cut the popliteofibular ligament, popliteus tendon, and the fibular collateral ligament. A posterior cruciate ligament reconstruction was performed in eight fresh-frozen cadaveric knees. One end of the graft was fixed to a tensioning jig with a load cell used to measure force in the graft as loads were applied to the knee. The force on the graft was significantly higher with the posterolateral structures cut during varus loading at 30°, 60°, and 90° of flexion than it was in the same joint under the same loading conditions but with the posterolateral structures intact. Additionally, coupled loading of posterior drawer force and external tibial torque at 30°, 60°, and 90° significantly increased force on the graft with the posterolateral structures cut. There was no significant increase in force on the graft under any condition with a posterior force, valgus force, or internal and external tibial torque applied alone. A significant increase in force occurs in a posterior cruciate ligament graft in knees with deficient posterolateral knee structures. We recommend that in knees with grade 3 posterolateral injuries and evidence of varus or coupled posterior-external rotation instability the posterolateral structures be repaired or reconstructed at the time of posterior cruciate ligament reconstruction to decrease the chance of later graft failure.
Effect of Pitch Type, Pitch Count, and Pitching Mechanics on Risk of Elbow and Shoulder Pain in Youth Baseball Pitchers
Authors: Lyman Stephen , Fleisig Glenn S. , Andrews James R. , Osinski E. David
Published: July 2017

Background

Joint pain is thought to be an early sign of injury to a pitcher.

Objective

To evaluate the association between pitch counts, pitch types, and pitching mechanics and shoulder and elbow pain in young pitchers.

Study Design

Prospective cohort study.

Methods

Four hundred and seventy-six young (ages 9 to 14 years) baseball pitchers were followed for one season. Data were collected from pre- and postseason questionnaires, injury and performance interviews after each game, pitch count logs, and video analysis of pitching mechanics. Generalized estimating equations and logistic regression analysis were used.

Results

Half of the subjects experienced elbow or shoulder pain during the season. The curveball was associated with a 52% increased risk of shoulder pain and the slider was associated with an 86% increased risk of elbow pain. There was a significant association between the number of pitches thrown in a game and during the season and the rate of elbow pain and shoulder pain.

Conclusions

Pitchers in this age group should be cautioned about throwing breaking pitches (curveballs and sliders) because of the increased risk of elbow and shoulder pain. Limitations on pitches thrown in a game and in a season can also reduce the risk of pain. Further evaluation of pain and pitching mechanics is necessary.
Motor Control of the Vastus Medialis Oblique and Vastus Lateralis Muscles is Disrupted during Eccentric Contractions in Subjects with Patellofemoral Pain
Authors: Owings Tammy M. , Grabiner Mark D.
Published: July 2017

Background

Inappropriate control of the vastus medialis oblique and vastus lateralis muscles by the central nervous system can contribute to maltracking of the patella.

Hypothesis

The activation timing and amplitude of the vastus medialis oblique and vastus lateralis muscles will be different between normal subjects and patients with patellofemoral pain.

Study Design

Controlled laboratory study.

Methods

Subjects with patellofemoral pain and asymptomatic control subjects performed maximum voluntary knee extension contractions initiated from a flexed and an extended position. The activation timing and amplitude of the vastus lateralis and vastus medialis oblique muscles were quantified from the recorded electromyographic signals.

Results

There were no between-group differences in activation timing. The activation amplitude of the vastus medialis oblique and vastus lateralis muscles of the patellofemoral pain subjects was altered to the greatest extent during eccentric contractions and differed significantly from that of control subjects.

Conclusions

The activation amplitudes of the vastus medialis oblique and vastus lateralis muscles of subjects with patellofemoral pain are consistent with a laterally tracking patella during eccentric contractions.

Clinical Relevance

The findings suggest the clinical importance of determining whether altered activation patterns are sensitive to rehabilitation, and, if so, if subjective reports of knee joint pain and function parallel changes in the activation patterns as a result of rehabilitation.
Rotator Cuff Tears in Middle-Aged Tennis Players: Results of Surgical Treatment
Authors: Sonnery-Cottet Bertrand , Edwards T. Bradley , Noel Eric , Walch Gilles
Published: July 2017

Background

Tennis players, like participants in other overhead sports, are vulnerable to rotator cuff tears. In players who continue to play into their middle-age years, the incidence of such injury increases.

Hypothesis

Surgical treatment of rotator cuff tears in middle-aged tennis players is largely successful in allowing return to tennis.

Study Design

Retrospective review.

Methods

We evaluated the results of surgical treatment of 51 middle-aged tennis players (average age, 51 years) with a rotator cuff tear in their dominant shoulder. Tennis participation among the group had averaged 3.5 hours per week for an average of 25 years. Forty-two patients underwent open repair of the tear with or without biceps tenodesis, whereas 9 patients underwent arthroscopic debridement of the tear with or without a biceps tenotomy. Patients were reviewed at an average of 57 months after surgery with an activities score, a subjective questionnaire, and a questionnaire regarding their postoperative participation in tennis.

Results

The activities score averaged 26.6 of 30 possible points. Forty-seven patients were satisfied with their result, and 40 patients were able to return to tennis at an average of 9.8 months after surgery. No difference was found in the ability to return to tennis between the open repair group and the arthroscopic debridement group.

Conclusions

The results of this study indicate that it is possible for nearly 80% of middle-aged tennis players to return to participation after operative treatment of rotator cuff tears.
Long-Term Outcome of Fasciotomy with Partial Fasciectomy for Chronic Exertional Compartment Syndrome of the Lower Leg
Authors: Slimmon Drew , Bennell Kim , Brukner Peter , Crossley Kay , Bell Simon N.
Published: July 2017

Background

Fasciotomy with partial fasciectomy for compartment syndrome has had good short-term results, but no long-term studies have been performed.

Hypothesis

Combining a partial fasciectomy with fasciotomy for compartment syndrome relieves pain and eliminates symptoms in the long term.

Study Design

Retrospective cohort study.

Methods

A self-administered questionnaire was given to 62 patients at a mean follow-up of 51 months after surgery.

Results

Of the 50 patients who underwent a single operation, 60% (30) reported an excellent or good outcome. Average pain and pain-on-running were significantly reduced, although some subjects still reported considerable levels of pain. Fifty-eight percent (36 of 62) were exercising at a lower level than before injury and, of these, 36% (13) cited the return of their compartment syndrome or the development of a different lower leg compartment syndrome as the reason for a reduction in exercise levels. Some subjects indicated early initial improvement followed by subsequent deterioration.

Conclusion

This surgical technique reduces pain and allows the majority of patients to return to sports; however, patients should be counseled that they may not be able to return to their preinjury level of exercise or remain pain-free.
Symptomatic, Partial Union of the Hook of the Hamate Fracture in Athletes
Authors: David Tal S. , Zemel Norman P. , Mathews Peter V.
Published: July 2017

Background

Many clinicians believe that after fracture of the hook of the hamate, nonunions are the rule rather than the exception.

Purpose

To describe a previously unreported condition in which the fractured hook of the hamate unites only along its ulnar column and causes pain similar to that in cases of nonunion.

Study Design

Retrospective review.

Methods

Eight patients who had sustained a hook of the hamate fracture were identified, on the basis of their persistent pain, as having achieved only partial union. This diagnosis was made despite evidence on computed tomography of healed bone across a significant portion of the fracture. All eight patients underwent subperiosteal excision of the hamulus because of persistent pain. At an average of 4 years after excision, each patient was evaluated by dynamometer grip strength testing and a subjective outcome assessment.

Results

All patients were able to return to their preinjury level of sports participation at an average 8 weeks after excision of the hook of the hamate. Grip strength was not adversely affected in any patient. Subjective evaluation of each patient revealed no residual pain.

Conclusions

Chronic or unresolved pain on the ulnar side of the wrist after hook of the hamate fracture can be due to partial union. This condition should be managed no differently from a symptomatic nonunion, with excision of the hook of the hamate and repair of the ligament attachments.
Dynamic Stabilizing Function of the Deltoid Muscle in Shoulders with Anterior Instability
Authors: Kido Tadato , Itoi Eiji , Lee Seok-Beom , Neale Patricia G. , An Kai-Nan
Published: July 2017

Background

The stabilizing role of the deltoid muscle has not been extensively studied.

Purpose

To study the contribution of the deltoid muscle to anterior stability of the shoulder.

Study Design

Controlled laboratory study.

Methods

We used nine fresh cadaveric shoulders with the arm at 90° of abduction and 90° of external rotation. The position of the humeral head was monitored by an electromagnetic tracking device with 0 and 1.5 kg of anterior translation force; with 0, 1, 3, and 5 kg of force applied to each of the anterior, middle, and posterior portions of the deltoid muscle; and with the capsule intact, vented, and with a simulated Bankart lesion.

Results

With the capsule intact, anterior displacement was significantly reduced by application of load to the middle deltoid muscle. After the capsule was vented, load application to the anterior, middle, or posterior deltoid muscle significantly reduced anterior displacement. With a simulated Bankart lesion, effects of muscle loading were most apparent: anterior displacement was significantly reduced with loading of each muscle portion.

Conclusion

The deltoid muscle is an anterior stabilizer of the glenohumeral joint with the arm in abduction and external rotation.

Clinical Relevance

The stabilizing function of the deltoid muscle takes on more importance as the shoulder becomes unstable.
The Biomechanical Effect of Posterior Cruciate Ligament Reconstruction on Knee Joint Function
Authors: Gill Thomas J. , DeFrate Louis E. , Wang Conrad , Carey Christopher T. , Zayontz Shay , Zarins Bertram , Guoan Li
Published: July 2017

Background

The effectiveness of posterior cruciate ligament reconstruction in restoring normal kinematics under physiologic loading is unknown.

Hypothesis

Posterior cruciate ligament reconstruction does not restore normal knee kinematics under muscle loading.

Study Design

In vitro biomechanical study.

Methods

Kinematics of knees with an intact, resected, and reconstructed posterior cruciate ligament were measured by a robotic testing system under simulated muscle loads. Anteroposterior tibial translation and internal-external tibial rotation were measured at 0°, 30°, 60°, 90°, and 120° of flexion under posterior drawer loading, quadriceps muscle loading, and combined quadriceps and hamstring muscle loading.

Results

Reconstruction reduced the additional posterior tibial translation caused by ligament deficiency at all flexion angles tested under posterior drawer loading. Ligament deficiency increased external rotation and posterior translation at angles higher than 60° of flexion when simulated muscle loading was applied. Posterior cruciate ligament reconstruction reduced the posterior translation and external rotation observed in posterior cruciate ligament-deficient knees at higher flexion angles, but differences were not significant.

Conclusion

Under physiologic loading conditions, posterior cruciate ligament reconstruction does not restore six degree of freedom knee kinematics.

Clinical Relevance

Abnormal knee kinematics may lead to development of long-term knee arthrosis.
Intraarticular Injuries Associated with Anterior Cruciate Ligament Tear: Findings at Ligament Reconstruction in High School and Recreational Athletes
Authors: Piasecki Dana P. , Spindler Kurt P. , Warren Todd A. , Andrish Jack T. , Parker Richard D.
Published: July 2017

Background

Despite research on the increased risk of anterior cruciate ligament tears in female athletes, few studies have addressed sex differences in the incidence of associated intraarticular injuries.

Hypothesis

When patients are stratified by sport and competition level, no sex differences exist in either the mechanism of injury or pattern of intraarticular injuries observed at anterior cruciate ligament reconstruction.

Study Design

Prospective cohort study.

Methods

Two hundred twenty-one athletes undergoing anterior cruciate ligament reconstruction met our inclusion criteria of anterior cruciate ligament tear as a singular event without reinjury or history of prior injury or surgery in either knee. Data were collected on competition level (high school, amateur), sport (basketball, soccer, skiing), mechanism of injury, articular cartilage injuries, and meniscal tears. Data were statistically analyzed by sex with the chi-square test and Student's t-test.

Results

High school athletes had no significant sex differences in mechanism of injury. Female soccer athletes had fewer medial meniscal tears than did male athletes, and female basketball players had fewer medial femoral condyle injuries. At the amateur level, female basketball players had more contact injuries, an earlier onset of swelling, and fewer lateral meniscal tears than did male players.

Conclusion

At the high school level, male and female athletes shared a common mechanism of injury, and yet the female athletes had fewer intraarticular injuries in basketball and soccer. If such intraarticular injuries prove to be a significant risk factor for poor long-term outcome, women may enjoy a better prognosis after reconstruction.
Reconstruction of the Coracoclavicular Ligaments with Tendon Grafts
Authors: Lee Steven J. , Nicholas Stephen J. , Akizuki Kenneth H. , McHugh Malachy P. , Kremenic Ian J. , Ben-Avi Simon
Published: July 2017

Background

Numerous surgical techniques have been described to address injuries to the coracoclavicular ligaments.

Purpose

To compare the biomechanical properties of tendon graft reconstructions with those of the native coracoclavicular ligaments and various other repair methods.

Study Design

Controlled laboratory study.

Methods

Eleven fresh-frozen human cadaveric shoulders were tensile tested to failure to compare the biomechanical properties of the native coracoclavicular ligaments, coracoacromial ligament transfer, No. 5 Mersilene suture repair, 5-mm Mersilene tape repair, and tendon graft reconstructions with gracilis, semitendinosus, and long toe extensor tendons.

Results

Reconstructions with semitendinosus, gracilis, or long toe extensor tendon grafts were found to have superior initial biomechanical properties compared with coracoacromial ligament transfer; failure strengths were as strong as those of the native coracoclavicular ligaments. Failure of the tendon grafts occurred through the midsubstance of the tendon graft, not at the fixation site.

Conclusions

Tendon graft reconstruction may be an alternative to coracoacromial ligament transfer and may provide a permanent biologic reconstruction with superior initial biomechanical properties, including that of tensile strength.

Clinical Relevance

Use of tendon graft reconstruction may limit the need for postoperative immobilization and lead to an accelerated rehabilitation program.
Effect of Hemorrhage on Medial Collateral Ligament Healing in a Mouse Model
Authors: Wright Rick W. , Parikh Manish , Allen Tracy , Brodt Michael D. , Silva Matthew J. , Botney Mitchell D.
Published: July 2017

Background

Medial collateral ligament injuries heal by a scar response.

Hypothesis

increased hemorrhage at the site of medial collateral ligament injury improves healing.

Study Design

Controlled laboratory study.

Methods

Ninety-six mice were divided into two groups. Group 1 mice underwent knee medial collateral ligament transection with the opposite knee as a sham-operated control and group 2 animals additionally had 0.25 ml of tail cut blood pipetted to the medial collateral ligament transection site and sham-operated opposite knee. Ligament specimens were harvested at 3, 7, 21, and 28 days.

Results

Immunohistochemical analysis demonstrated peak macrophage counts at day 7 in all transected specimens. Macrophage counts were higher in group 2 than in group 1 at all time points, with a statistically significant increase of macrophages noted at day 7. In situ hybridization demonstrated increased collagen gene expression, with peaks at 7 and 28 days after transection. Group 2 animals showed increased gene expression at all time points as compared with group 1, with a statistically significant increase noted at 7 and 28 days. Biomechanical testing demonstrated progressive healing at each time point. At 28 days, the load to failure was 67% that of the sham-operated knee.

Conclusions

This study suggests there is an increased healing response with bleeding at the ligament injury site.

Clinical Relevance

Identification of the factors involved with increased healing may allow manipulation of the healing response in the clinical setting.
Effects of Graft Rotation on Initial Biomechanical Failure Characteristics of Bone-Patellar Tendon-Bone Constructs
Authors: Verma Nikhil , Noerdlinger Mayo A. , Hallab Nadim , Bush-Joseph Charles A. , Bach Bernard R.
Published: July 2017

Background

Graft-tunnel mismatch is a potential problem during single-incision technique for anterior cruciate ligament reconstruction with the central third of the patellar tendon. Mismatch is present when the graft is too long to fit appropriately in the tunnels that have been created. Graft rotation is one method for addressing this problem.

Purpose

To determine the results of graft rotation up to 540° on initial graft biomechanical properties and graft length.

Study Design

Controlled laboratory study.

Methods

Forty porcine bone-patellar tendon-bone constructs were divided into four groups and constructs were rotated to 0°, 90°, 180°, and 540°, respectively, for each group. Biomechanical testing to failure was performed with the constructs under tension at an elongation rate of 5 cm/sec. Lengths were measured after a 1-kg load was applied to the grafts.

Results

No statistical difference in ultimate failure strength was encountered between any of the groups (P = 0.915). The grafts that were twisted to 540° shortened an average of 5.41 mm, which represented an average shortening of 10% of the initial tendon length.

Clinical Relevance

Graft rotation up to 540° does not result in loss of initial graft strength, and may be a solution for graft-tunnel mismatch.
Injuries to the Upper Extremity in Ice Hockey
Authors: Mölsä Jouko , Kujala Urho , Myllynen Pertti , Torstila Ilkka , Airaksinen Olavi
Published: July 2017

Background

Injuries to the upper extremity are common in ice hockey.

Purpose

To investigate the mechanisms, types, and severity of upper extremity ice hockey injuries in patients in different age categories.

Study Design

Retrospective cohort study.

Methods

We analyzed 760 consecutive upper extremity injuries in Finnish ice hockey players reported to an insurance company during 1996.

Results

The overall injury rate of upper extremity injuries was 14.8 per 1000 player-years; 70% occurred during games. Of the 861 injury types, 32% were contusions, 28% sprains or strains, and 27% fractures. Checking or other collisions with players caused 76% of the injuries to the shoulder (170 of 223), 55% of the injuries to the elbow (35 of 64), and 45% of the injuries to the distal extremity (213 of 473). Of the 561 injuries with known severity, 38% were major. The injury risk increased significantly with age, from players younger than 12 years to players 25 to 29 years of age. The injury profile among 15- to 19-year-old players was similar to that of adult players.

Conclusions

Injuries to the upper extremity are relatively serious because of the high number of shoulder injuries and fractures. The frequency of injuries increased with age. A considerable proportion of upper extremity injuries was caused by body checking.
Chronic Exertional Compartment Syndrome
Authors: Hislop Matthew , Tierney Paul , Murray Pairic , O'Brien Moira , Mahony Nick
Published: July 2017

Background

The existence of a “fifth” compartment in the leg capable of developing distinct chronic exertional compartment syndrome remains a subject of controversy.

Hypothesis

Specific pressure recordings and dissection will confirm or disprove the existence of a fifth compartment.

Study Design

Empirical anatomic study.

Methods

Radiopaque dye was injected directly into the tibialis posterior muscle of 25 embalmed cadaveric legs while intracompartmental pressure was monitored. Radiographs demonstrated dye distribution, and dissection-documented fascial and epimysial layers.

Results

Evidence was found that the fibular origin of the flexor digitorum longus muscle, when present, could create subcompartments within the deep posterior compartment. The nature of this attachment varied from being absent, to small (<8 cm), to extensive (>8 cm). The attachment partially covered the tibialis posterior muscle in the majority of the 14 legs that developed high pressures, and it was limited or absent in the 11 legs that did not. Radiographs demonstrated that the dye was confined to the tibialis posterior muscle in four legs.

Conclusions

No consistent fifth compartment exists in the leg; however, subcompartments within the deep posterior compartment created by the fibular origin of the flexor digitorum longus muscle may develop pressures congruent with chronic exertional compartment syndrome.

Clinical Relevance

Potential deep posterior subcompartments demand accurate pressure investigation. A modified technique to decompress the entire deep posterior compartment, including the tibialis posterior muscle, is necessary for successful treatment of chronic exertional compartment syndrome.
The Diagnosis and Treatment of Superior Labrum, Anterior and Posterior (SLAP) Lesions
Authors: Nam Ellis K. , Snyder Stephen J.
Published: July 2017

The advent of shoulder arthroscopy, as well as our improved understanding of shoulder anatomy and biomechanics, has led to the identification of previously undiagnosed lesions involving the superior labrum and biceps tendon anchor. Although the history and physical examination, as well as improved imaging modalities such as magnetic resonance arthrography, are extremely important in understanding the abnormalities, the definitive diagnosis of superior labrum, anterior and posterior lesions is best made through diagnostic arthroscopy. Treatment of these lesions is directed according to its type. In general, type I and III lesions are debrided, whereas type II and many type IV lesions are repaired. The purpose of this article is to review the anatomy, biomechanics, classification, diagnosis, and current treatment recommendations for these lesions, as well as to review the literature.
Injury Rates in Rugby League Football: Impact of Change in Playing Season
Authors: Gissane Conor , Jennings De , Kerr Kathleen , White John
Published: July 2017

Background

In 1996, the professional rugby league moved its playing season from the autumn and winter months to the spring and summer.

Purpose

To determine whether the change in playing season altered the risk of player injury.

Study Design

Prospectively collected data comparing two cohorts.

Methods

Injuries incurred by all players in one club during match play were recorded over 9 seasons: 4 winter (138 games) and 5 summer (144 games). Each injury was classified according to site, type, player position, activity at the time of injury, and number of games missed as a result of injury.

Results

The total exposure time during this study was 4876 player-hours (winter, 2386, summer, 2490). The relative risk of injury doubled after the move from winter to summer. Winter rugby accounted for 72 injuries, and summer rugby, for 150 injuries.

Conclusions

Risk of injury to players in a professional rugby league club greatly increased as a result of changing the playing calendar, possibly as a result of environmental factors. However, other factors, such as increased conditioning levels, which have been a direct consequence of players moving to full-time professionalism, may have increased injury potential.
Biodegradable Interference Screw Fixation Exhibits Pull-Out Force and Stiffness Similar to Titanium Screws
Authors: Weiler Andreas , Windhagen Henning J. , Raschke Michael J. , Laumeyer Andrea , Hoffmann Reinhard F. G.
Published: July 2017

Recently, increased interest in biodegradable interference screws for bone-tendon-bone graft fixation has led to numerous screws becoming available. The implants are made from different polymers and have different designs, which might influence their mechanical properties. Several studies have reported a wide range of mechanical results for these screws using different biomechanical models. The aim of the present study is to compare reliable biomechanical data for six different biodegradable interference screws, consisting of five different polymers, with a conventional titanium screw in a standardized model. Seventy proximal calf tibias were used to determine maximal pull-out force, stiffness of fixation, and insertion torque for interference screw fixation of bone-tendon-bone grafts. Additionally, maximal torque at failure was determined. Data were analyzed with respect to aspects of screw design, such as drive and thread shape. Five of the six biodegradable screws provided initial pull-out force and stiffness of fixation comparable with that of a conventional titanium screw. Torque at failure can be greatly increased by adapting the drive design to the mechanical properties of the polymeric raw material. A correlation between pull-out force and thread height indicates that fixation rigidity depends on screw design, even in a biodegradable implant.
Subacute Scaphoid Fractures
Authors: Mack Gregory R. , Wilckens John H. , McPherson Scott A.
Published: July 2017

Twenty-three subacute scaphoid fractures were retrospectively reviewed to determine the efficacy of non-operative treatment. All of the patients sought medical attention between 4 weeks and 6 months after injury, and their fractures were classified according to location and stability. Nineteen fractures were observed to radiographic union or until closed treatment was abandoned; four patients were lost to followup. Nine of 10 stable subacute middle-third scaphoid fractures healed with cast immobilization in an average of 19 weeks (range, 11 to 38), and these were compared with a randomly selected group of acute middle-third fractures that healed in an average of 10 weeks (range, 6 to 13). Five of six unstable subacute middle-third fractures healed in an average of 20 weeks. One of these had a symptomatic humpback deformity treated by cheilectomy. Of three subacute proximal-third fractures, only one healed after 29 weeks of closed treatment. This study demonstrates that stable subacute middle-third scaphoid fractures will heal with cast treatment but may take twice as long to do so as stable acute middle-third fractures. Unstable subacute middle-third scaphoid fractures and subacute proximal-third fractures appear less likely to heal with closed treatment.
Arthroscopic Distal Clavicle Resection For Isolated Atraumatic Osteolysis in Weight Lifters
Authors: Auge Wayne K. , Fischer Richard A.
Published: July 2017

Ten consecutive patients with isolated atraumatic osteolysis of the distal clavicle who had failed results with conservative treatment were treated with arthroscopic resection of the involved distal clavicle (average, 4.5 mm). All patients were men with an average age of 30.4 years, had unilateral involvement, and were considered aggressive amateur to elite weight lifters or bodybuilders. Postoperative symptoms consisted of pain at the incision and discomfort from extravasation of the irrigation fluid. At an average followup of 18.7 months, all patients had returned to their sport (average, 3.2 days) and to their preoperative weight training program (average, 9.1 days). They continued to be asymptomatic throughout the follow-up period and were able to increase both their training volume and strength from preoperative levels. Limited arthroscopic resection of the distal clavicle for isolated atraumatic osteolysis is a viable alternative for the weight lifter or bodybuilder. The ability to continue training without significant interruption as well as a more acceptable cosmetic appearance are benefits for these patients. Limited arthroscopic resection of the distal clavicle may be sufficient for this entity in this patient population, rather than the 1 to 2 cm previously reported. A sport-specific functional outcome questionnaire has been developed for this patient population.
Electromyographic Activity and Applied Load During Shoulder Rehabilitation Exercises Using Elastic Resistance
Authors: Hintermeister Robert A. , Lange Gregory W. , Schultheis Jeanne M. , Bey Michael J. , Hawkins Richard J.
Published: July 2017

Muscle activity (measured by electromyography) and applied load were measured during seven shoulder rehabilitation exercises done with an elastic resistance device. Nineteen men with no shoulder abnormalities performed seven exercises: external and internal rotation, forward punch, shoulder shrug, and seated rowing with a narrow, middle, and wide grip. Qualitative video (60 Hz) was synchronized with the electromyography data from eight muscles (2000 Hz). Fine-wire intramuscular electrodes were inserted into the supraspinatus and subscapularis muscles, and surface electrodes were placed over the anterior deltoid, infraspinatus, pectoralis major, latissimus dorsi, serratus anterior, and trapezius muscles. Ten trials per subject were analyzed for average and peak amplitude, and the results were expressed as a percentage of maximum voluntary contractions. The peak loads for all exercises ranged from 21 to 54 N. The muscle activity patterns suggest that these shoulder rehabilitation exercises incorporating elastic resistance, controlled movements, and low initial loading effectively target the rotator cuff and supporting musculature and are appropriate for postinjury and postoperative patients.
The Relationship Between Intercondylar Notch Width of the Femur and the Incidence of Anterior Cruciate Ligament Tears
Authors: Shelbourne K. Donald , Davis Thorp J. , Klootwyk Thomas E.
Published: July 2017

For 714 consecutive patients who underwent autogenous patellar tendon graft anterior cruciate ligament reconstructions we intraoperatively measured intercondylar notch width. We prospectively recorded height, weight, sex, and which patients subsequently tore their contralateral anterior cruciate ligament or the 10-mm autograft. The patients were divided into two groups based on notch width (group 1, 15 mm; group 2, 16 mm). The mean notch width was 13.9 2.2 mm for women and 15.9 2.5 mm for men. There was no statistically significant difference in notch width between height groups for women or men. Analysis showed that, with height and weight as covariates, women had statistically significantly narrower notches than men. Twenty-three of 388 patients in group 1 and 4 of 326 patients in group 2 tore their contralateral anterior cruciate ligaments. Within groups, no statistically significant differences in contralateral tear rates existed between men and women. Once the men and women had reconstructions with equally sized 10-mm autografts, there was no difference in graft tear rate between groups or between men and women. Our results show that patients with narrower notches have a higher incidence of tearing their contralateral anterior cruciate ligament. After reconstruction with a 10-mm autograft, the incidence of graft rupture is the same for men and women.
Concussion History in Elite Male and Female Soccer Players
Authors: Barnes Brett C. , Cooper Leslie , Kirkendall Donald T. , McDermott T. Paul , Jordan Barry D. , Garrett William E
Published: July 2017

A unique feature of soccer is the purposeful use of the head for controlling, passing, and shooting a soccer ball. Some concern has been expressed in the literature on the cumulative effects of heading on soccer players. Certain neurophysiologic and neuropsychologic changes have been reported in current or retired players, with heading being blamed. A major factor that could influence some of the findings is a player's history of concussive episodes, which are known to influence brain function. These episodes can occur during aspects of the game other than heading. We interviewed all male and female soccer players (N 137, average age 20.5 years) who competed at the U.S. Olympic Sports Festival in 1993. The mechanisms of injuries, frequency, and sequelae were determined. There were 74 concussions in 39 male players (grade I 50) and 28 concussions in 23 female players (grade I 19). For the men, 48 of the 74 episodes were from collisions with another player. For the women, 20 of 28 were from such collisions. Headaches, being “dazed,” and dizziness were the most common symptoms reported. Based on concussion history, the odds are 50% that a man, and 22% that a woman, will sustain a concussion within a 10-year period. The data indicate that concussions from player-to-player contact are a frequent hazard in soccer. Head injuries incurred this way may be more of an influence for published findings of physiologic and psychologic deficiencies than routine heading of the soccer ball.
Disruption of the Finger Flexor Pulley System in Elite Rock Climbers
Authors: Gabl Markus , Rangger Christoph , Lutz Martin , Fink Christian , Rudisch Ansgar , Pechlaner Sigurd
Published: July 2017

We treated 13 elite rock climbers for isolated disruptions of the pulleys of the long fingers. Diagnosis and treatment were based on the clinical finding of bowstringing, which was confirmed by magnetic resonance imaging. Eight patients had bowstringing indicating incomplete disruption of the major pulley A2 and were treated nonoperatively (group A). Five patients showed bowstringing indicating complete disruption of the pulley A2. After failed nonoperative treatment, the pulleys were reconstructed (group B). The mechanism of injury and clinical and subjective results were evaluated. At a 31-month follow-up (range, 18 to 43 months), loss of extension in the proximal interphalangeal joint measured 5.6° (range, 0° to 10°) in group A and 4° (range, 0° to 10°) in group B. Circumference of the finger section was increased 4.2 mm in group A (range, 0 to 10 mm) and 4.8 mm in group B (range, 0 to 10 mm). Grip strength decreased 20 N in group A (range, 10 to 50 N) and 12 N in group B (range, 10 to 30 N). Four patients in group A and one in group B had bowstringing at clinical evaluation. On follow-up magnetic resonance images, bowstringing remained unchanged in group A but was reduced in all patients in group B. Good subjective results were seen in both groups.
Bankart Procedure Augmented by Coracoid Transfer for Contact Athletes with Traumatic Anterior Shoulder Instability
Authors: Yoneda Minoru , Hayashida Kenji , Wakitani Shigeyuki , Nakagawa Shigeto , Fukushima Sunao
Published: July 2017

We investigated the clinical efficacy of the Bankart procedure augmented by coracoid transfer for traumatic anterior shoulder instability in athletes playing contact sports. Eighty-three athletes (85 joints) with traumatic anterior shoulder instability who underwent the combined procedure were studied. The mean patient age at surgery was 21 years, and the mean follow-up period was 5.8 years (range, 2 to 12). According to the Rowe scoring system, the clinical results were graded as excellent for 58 shoulders, good for 21, fair for 5, and poor for 1, with an average score of 91 points. The overall success rate was 93%. A complete return to contact sports was achieved by 73 of the 83 patients (88%). The average loss of external rotation was 15° with the arm at the side and 7° with the arm in 90° of abduction. The complications were nonunions in two cases, screw breakage in one case, and axillary nerve injury in one. This procedure can achieve a good clinical outcome for contact athletes with traumatic anterior shoulder instability.
Treatment of Simple Elbow Dislocation Using an Immediate Motion Protocol
Authors: Ross Glen , McDevitt Edward R. , Chronister Raymond , Ove P. Norman
Published: July 2017

The results of treatment after closed reduction of elbow dislocation vary. Twenty consecutive patients with closed posterior elbow dislocations were treated prospectively on a rapid motion, nonimmobilized functional regimen. This treatment protocol emphasizes immediate active range of motion under close supervision. No slings or splints were employed. Final range of motion averaged 4° to 139°. All patients attained final extension within 5° of the contralateral side. Each patient achieved his final range of motion within an average of 19 days after reduction of the dislocation. Arm circumference returned to normal at an average of 6.5 days. There was one redislocation. After treatment, all patients met qualification for graduation from the U.S. Naval Academy and were able to pursue unrestricted athletic and career options. Our findings suggest that an aggressive immediate motion rehabilitation allows nearly full final elbow motion and an excellent functional outcome.
Radiographic Abnormalities of the Lumbar Spine in College Football Players
Authors: Jones Darron M. , Tearse David S. , El-Khoury Georges Y. , Kathol Mary H. , Brandser Eric A.
Published: July 2017

The purpose of this study was to make a direct comparison between lumbar spine radiographs of incoming college football players and of an age-matched control group to determine whether there is a higher prevalence of lumbar spine abnormalities in football players before competing at the Division I level. We reviewed 187 lumbar spine radiographs. Of these, 104 were taken as a standard part of the preparticipation physical examination for incoming college football players. The remaining 83 radiographs were taken during routine preemployment physicals at a local factory. Each radiograph was read independently by three separate orthopaedic radiologists in a blinded fashion. Data were collected and statistically evaluated for 13 variables. The rate of spondylolysis was only 4.8% in our group of athletes and 6.0% in the control group (not significantly different). Only in the category of degenerative changes was a significant difference found. The control group had a 16.9% incidence of disk space narrowing and spurring and the football players had a 6.7% incidence. The remainder of the variables were not significantly different between the two groups. Our findings differ from previously published reports and indicate that football players entering college at the Division I level may have a similar prevalence of radiographic lumbar spine abnormalities, including spondylolysis and spondylolisthesis, as age-matched controls.