bluuebunny/crossref_metadata_2025 huggingface dataset:
Renal Disease in Squirrel Monkeys (Saimiri sciureus)
Authors: Stills H. F. , Bullock B. C.
Published: July 2017

Renal lithiasis, pyelonephritis, and glomerulonephritis were common in our colony of Brazilian phenotype squirrel monkeys (Saimiri sciureus), with glomerulonephritis being a major cause of mortality in adult animals. Squirrel monkey glomerulonephritis was divided into four major classifications, based on light and electron microscopy, similar to those of man: focal sclerosing glomerulonephritis, membranoproliferative glomerulonephritis, membranous glomerulonephritis, and a combination of membranoproliferative and membranous glomerulonephritis.
Renal Disease in the Pigtailed Macaque (Macaca nemestrina)
Authors: Giddens W. E. , Boyce J. T. , Blakley G. A. , Morton W. R.
Published: July 2017

Spontaneous renal disease in the pigtailed macaque was evaluated in a prospective study of 20 apparently healthy monkeys that were killed and a retrospective study of 674 monkeys that died of spontaneous disease. Many apparently normal pigtailed macaques have a mesangioproliferative glomerulonephritis of slight to moderate severity. Deposition of immunoglobulins, particularly IgM, was common in renal glomeruli and did not seem to correlate with renal disease.

Glomerulonephritis was found in 14% of the adult monkeys that died of spontaneous disease; in 4.2% it was severe enough to have caused renal failure. Tubular nephrosis was the most common renal lesion (22.6% of adults) and was usually a nephrotoxicity resulting from treatment of diarrhea with nephrotoxic antibiotics. Other lesions found were incidental or were secondary to disease processes in other organs. Pigtailed macaques that have been in our colony at least six months have a higher incidence of renal disease than is reported elsewhere in Old World monkeys.
Open Revision Stabilization Surgery for Recurrent Anterior Glenohumeral Instability
Authors: Levine William N. , Arroyo Julian S. , Pollock Roger G. , Flatow Evan L. , Bigliani Louis U.
Published: July 2017

Fifty patients (average age, 27 years) who underwent revision anterior stabilization surgery for failed anterior glenohumeral instability procedures were retrospectively reviewed. Failure of the original procedure occurred subsequent to significant trauma in only 17 of 50 shoulders. At revision, 49 shoulders underwent an anteroinferior capsular shift procedure and 23 underwent concurrent repair of a Bankart lesion. One shoulder was treated with a coracoid transfer to reconstruct the anteroinferior glenoid. At an average follow-up of 4.7 years (range, 2 to 10), there were 36 excellent and 3 good results (78%). Eleven shoulders were considered unsatisfactory (22%); 7 of these 11 patients had a diagnosis of voluntary dislocation. All 17 patients who had failed results after significant trauma had excellent results after revision surgery. However, only 22 of the 33 patients (67%) with atraumatic recurrent instability achieved excellent or good results after revision surgery. This difference was statistically significant. No patients had radiographic evidence of osteoarthritis at the most recent follow-up. Range of motion, return to function, and glenohumeral stability can be reliably restored in a high percentage of patients after revision anterior stabilization surgery for glenohumeral instability. However, the results are not as predictable as for primary surgery. Factors associated with poor results of revision repair included an atraumatic cause of failure, voluntary dislocations, and multiple prior stabilization attempts.
Open and Arthroscopic Patellar Tenotomy for Chronic Patellar Tendinopathy
Authors:   Victorian Institute of Sport Tendon Study Group, Coleman Brett D. , Khan Karim M. , Kiss Zoltan S. , Bartlett John , Young David A. , Wark John D.
Published: July 2017

Chronic patellar tendinopathy often requires surgical treatment. We compared the outcomes in 25 subjects (29 tendons) who had had open patellar tenotomy and 23 subjects (25 tendons) who had had arthroscopic patellar tenotomy at a mean follow-up of 3.8 and 4.3 years, respectively. At follow-up, outcomes in the open and arthroscopic groups were as follows: 1) symptomatic benefit was seen in 81% of open and 96% of arthroscopic tenotomy patients, 2) sporting success was seen in 54% of open and 46% of arthroscopic tenotomy patients, 3) median time to return to preinjury level of activity was 10 months for open and 6 months for arthroscopic tenotomy patients, and 4) median Victorian Institute of Sport Assessment score at follow-up was 88 for open and 77 for arthroscopic tenotomy patients. There were no significant differences between groups for all outcomes. The appearance of the tendon on sonography remained abnormal in over 70% of subjects at follow-up, and sonographic appearance did not correlate with clinical outcome. Thus, arthroscopic patellar tenotomy was as successful as the traditional open procedure. Both procedures provided virtually all subjects with symptomatic benefit, but only about half the subjects who underwent either open or arthroscopic patellar tenotomy were competing at their former sporting level at follow-up.
Using Bone's Adaptation Ability to Lower the Incidence of Stress Fractures
Authors: Milgrom Charles , Simkin Ariel , Eldad Arieh , Nyska Meir , Finestone Aharon
Published: July 2017

In three prospective epidemiologic studies of the effect of pre-military-induction sport activities on the incidence of lower extremity stress fractures during infantry basic training, recruits who played ball sports (principally basketball) regularly for at least 2 years before basic training had a significantly lower incidence of stress fractures (13.2%, 16.7%, and 3.6% in the three studies, respectively) than recruits who did not play ball sports (28.9%, 27%, and 18.8%, respectively). Preinduction running was not related to the incidence of stress fracture. To assess the tibial strain environment during these sport activities, we made in vivo strain measurements on three male volunteers from the research team. Peak tibial compression and tension strain and strain rates during basketball reached levels 2 to 5.5 times higher than during walking and about 10% to 50% higher than during running. The high bone strain and strain rates that occurred in recruits while playing basketball in the years before military induction may have increased their bone stiffness, according to Wolff's Law. The stiffer bone could tolerate higher stresses better, resulting in lower strains for a given activity and a lower incidence of stress fractures during basic training.
The Influence of Functional Knee Bracing on the Anterior Cruciate Ligament Strain Biomechanics in Weightbearing and Nonweightbearing Knees
Authors: Fleming Braden C. , Renstrom Per A. , Beynnon Bruce D. , Engstrom Bjorn , Peura Glenn
Published: July 2017

Functional knee braces are commonly prescribed after anterior cruciate ligament injury or reconstruction; however, their ability to protect the ligament, or graft, remains unclear. Our objective was to evaluate the anterior cruciate ligament strain response in braced and unbraced knees during weightbearing and nonweightbearing in combination with three externally applied loads: 1) anterior-posterior shear forces, 2) internal-external torques, and 3) varus-valgus moments. The Legend brace was tested. All external loads were applied to the tibia with the knee flexed to 20°. Reproducible data were obtained from 11 subjects. For anterior shear loads up to 130 N, the brace significantly reduced strain values compared with the unbraced knee during nonweightbearing and weightbearing conditions. For internal torques of the tibia (up to 9 N m), strain in the braced knee was significantly less than in the unbraced knee when the knee was nonweightbearing only. The brace did not reduce strain values when the knee was subjected to external torques (9 N m) or varus-valgus moments (10 N m) in weightbearing and nonweightbearing knees. These data indicate that a functional knee brace can protect the anterior cruciate ligament during anterior-posterior shear loading in the nonweightbearing and weightbearing knee and during internal torques in the nonweightbearing knee.
Comparison of Score Evaluations and Instrumented Measurement after Anterior Cruciate Ligament Reconstruction
Authors: Hrubesch Ralph , Rangger Christoph , Reichkendler Markus , Sailer Romed Franz , Gloetzer Wulf , Eibl Günther
Published: July 2017

Forty-four patients who had undergone unilateral anterior cruciate ligament reconstructions were evaluated retrospectively with seven different scoring systems (International Knee Documentation Committee, Orthopädische Arbeitsgruppe Knie, Lysholm, Feagin and Blake, Zarins and Rowe, Cincinnati, and Marshall scores). The results varied between systems and therefore lacked reliability. Of the 44 patients, 32 were rated as excellent according to the Cincinnati score while only 3 patients were rated as normal according to the International Knee Documentation Committee form. Good and excellent results were found twice as frequently with the Cincinnati and Lysholm scores compared with the scores of Zarins and Rowe or the International Knee Documentation Committee form. Statistical analysis confirmed this observation and revealed significant differences between the scoring systems. Side-to-side differences using the manual maximum displacement test with the KT-1000 arthrometer revealed good correlation with the International Knee Documentation Committee and the Orthopädische Arbeitsgruppe Knie questionnaires. None of the other scoring systems, which do not measure anterior laxity, produced reasonable correlation with instrumented measurements. We found that certain population-specific factors as well as the distribution of single findings can distort the results of scoring systems. To avoid these interference factors, the patient sample should be homogeneous and selected prospectively and there should be agreement about the value of single findings.
Fixed Tibial Subluxation after Successful Anterior Cruciate Ligament Reconstruction
Authors: Almekinders Louis C. , de Castro Donny
Published: July 2017

Anterior cruciate ligament reconstruction results in improved function and stability in many patients. However, it is not known whether the improved stability is associated with an improved tibiofemoral relationship. We used stress radiographs to determine not only stability but also the tibiofemoral relationship in 15 patients who had a clinically successful anterior cruciate ligament reconstruction. Their results were compared with those of 14 volunteers with normal knees. The average Lysholm score for the patients was 94. None of the patients had more than 3 mm of side-to-side difference on KT-1000 arthrometer testing. Maximal anteroposterior tibial translation as measured by stress radiography was slightly increased in the reconstructed knees but was not statistically significantly different (6.6±3.2 mm versus 5.0±3.3 mm). However, with a posteriorly directed stress the tibia in the reconstructed knees did not translate posteriorly to the same extent as did the control knees, resulting in a significant difference in tibial position (1.2±3.0 mm versus –4.0±3.3 mm). Surgical anterior cruciate ligament reconstruction may result in reduced anteroposterior tibial translation, accomplished, in part, through restraining posterior translation, leaving the tibia with persistent subluxation. Fibrosis and contracture of the posterior structures may explain this phenomenon.
The Effect of Exercise on Anterior-Posterior Translation of the Normal Knee and Knees with Deficient or Reconstructed Anterior Cruciate Ligaments
Authors: Kirkley Alexandra , Mohtadi Nicholas , Ogilvie Richard
Published: July 2017

Exercise may result in increased laxity in the knee. Anterior translation in 40 normal knees, 33 consecutive anterior cruciate ligament-deficient knees, and 30 randomly chosen anterior cruciate ligament-reconstructed knees was measured using the KT-1000 arthrometer before and after the participants ran for 15 minutes on a neutral-incline treadmill. A single observer blinded to the status of each knee tested all participants. There was a significant increase in anterior translation in the normal (mean, 0.75 mm), anterior cruciate ligament-deficient (mean, 0.62 mm), and anterior cruciate ligament-reconstructed knees (mean, 0.25 mm) after exercise. In addition, the amount of anterior translation after exercise was significantly different when these groups were compared with each other. Post hoc analysis using Tukey's procedure indicated that anterior translation in the anterior cruciate ligament-reconstructed knee was significantly less than in the normal and anterior cruciate ligament-deficient knees. Therefore, repetitive loading exercise contributes to an increase in anterior translation in normal, anterior cruciate ligament-deficient, and anterior cruciate ligament-reconstructed knees, and the anterior cruciate ligament-reconstructed knee does not respond to repetitive loading in the same manner as a normal knee.
Medially Based Anterior Capsular Shift of the Glenohumeral Joint
Authors: Hurschler Christof , Wülker Nikolaus , Windhagen Henning , Plumhoff Piet , Hellmers Niels
Published: July 2017

The effect of a medially based anterior capsular shift on translational and rotational range of motion and posterior capsular strain was investigated in an in vitro model. Six cadaveric shoulders were tested in a robot-assisted shoulder simulator. Translational and rotational range of motion were reduced by the capsular shift, particularly with the shoulder at higher elevation angles. At 60° of elevation, anterior translation was decreased 1.9±2.9 mm, and posterior translation was decreased 2.3±6.2 mm. External rotation was decreased 11.5°±10.2°, and internal rotation was decreased 8.9°±5.7°. Posterior capsular strain change was dependent on elevation angle. At 30° of elevation, strain tended to increase 5.0%±7.3% in the inferior aspect and 2.9%±2.6% in the superior aspect, with no change detected in the medial aspect. At 60° of elevation, strain increased 6.6%±8.0%, 3.2%±2.6%, and 4.4%±3.5% in the inferior, middle, and superior aspects, respectively. Our results support the use of the medially based anterior shift for shoulders with anterior-inferior instability or multidirectional instability with posterior involvement.
The Kinematics and Kinetics of Slipknots for Arthroscopic Bankart Repair
Authors: Hughes Peter J. , Hagan Richard P. , Fisher Anthony C. , Holt E. Martin , Frostick Simon P.
Published: July 2017

An apparatus has been developed to enable the in vitro measurement of the kinematics and kinetics of a slipknot, both while the knot is being tightened and with the knot in place and the tension removed. During tightening, the apparatus provides a linearly increasing resistance, which may be considered analogous to the resistance experienced when the labrum is drawn toward and apposed to the edge of the glenoid cavity during a Bankart repair. The tension to close the knot is measured with a tensiometer, in tandem with the closure of the capsule model onto the bone anchor, which is measured with a datalogger. The tightening tension was limited to 25 N and intraoperator and interoperator comparisons were made for four knots tied by six participants. Failure of a knot was taken to be reverse slippage of 2 mm. A second criterion of ease of slide was used to assess each knot. We found wide interoperator variability with regard to slipknot tying. A methodology for quality control of slipknot tying is presented.
Biomechanical Properties and Vascularity of an Anterior Cruciate Ligament Graft can be Predicted by Contrast-Enhanced Magnetic Resonance Imaging
Authors: Weiler Andreas , Peters Gunnar , Mäurer Jürgen , Unterhauser Frank N. , Südkamp Norbert P.
Published: July 2017

Magnetic resonance imaging has been used to determine graft integrity and study the remodeling process of anterior cruciate ligament grafts morphologically in humans. The goal of the present study was to compare graft signal intensity and morphologic characteristics on magnetic resonance imaging with biomechanical and histologic parameters in a long-term animal model. Thirty sheep underwent anterior cruciate ligament reconstruction with an autologous Achilles tendon split graft and were sacrificed after 6, 12, 24, 52, or 104 weeks. Before sacrifice, all animals underwent plain and contrast-enhanced (gadolinium-diethylenetriamine pentacetic acid) magnetic resonance imaging (1.5 T, proton density weighted, 2-mm sections) of their operated knees. The signal/noise quotient was calculated and data were correlated to the maximum load to failure, tensile strength, and stiffness of the grafts. The vascularity of the grafts was determined immunohistochemically by staining for endothelial cells (factor VIII). We found that high signal intensity on magnetic resonance imaging reflects a decrease of mechanical properties of the graft during early remodeling. Correlation analyses revealed significant negative linear correlations between the signal/noise quotient and the load to failure, stiffness, and tensile strength. In general, correlations for contrast-enhanced measurements of signal intensity were stronger than those for plain magnetic resonance imaging. Immunohistochemistry confirmed that contrast medium enhancement reflects the vascular status of the graft tissue during remodeling. We conclude that quantitatively determined magnetic resonance imaging signal intensity may be a useful tool for following the graft remodeling process in a noninvasive manner.
Greater Tuberosity Notch: An Important Indicator of Articular-Side Partial Rotator Cuff Tears in the Shoulders of Throwing Athletes
Authors: Nakagawa Shigeto , Yoneda Minoru , Hayashida Kenji , Wakitani Shigeyuki , Okamura Kenji
Published: July 2017

We examined the location of rotator cuff tears, associated labral injuries, and notches on the greater tuberosity of the humeral head in shoulders of throwing athletes. Arthroscopic findings (rotator cuff tear, labral condition, and greater tuberosity notch) as well as other factors (duration of playing baseball, range of motion, and joint laxity) of 61 baseball players were retrospectively studied. The presence of a greater tuberosity notch was also evaluated for by plain radiographs. Forty patients had articular-side partial rotator cuff tears, most of which occurred in the interval between the supraspinatus and infraspinatus tendons. The existence of a rotator cuff tear was not related to the range of motion, joint laxity, the detachment of the superior glenoid labrum, or posterosuperior labral injury. Greater tuberosity notches were recognized in 38 shoulders by arthroscopy and most were detected on plain radiographs. The presence of a notch was significantly related to the existence of a rotator cuff tear, while the size of the notch was significantly related to the depth and width of the tear. The greater tuberosity notch seems to be one of the most important diagnostic indicators for a rotator cuff tear in throwing athletes.
Electromyographic Predictors of Residual Quadriceps Muscle Weakness after Anterior Cruciate Ligament Reconstruction
Authors: McHugh Malachy P. , Tyler Timothy F. , Browne Michael G. , Gleim Gilbert W. , Nicholas Stephen J.
Published: July 2017

Background

Despite the high prevalence of residual quadriceps muscle weakness after anterior cruciate ligament reconstruction, specific predictive factors have not been identified.

Hypothesis

Electromyographic analysis is a better predictor of residual muscle weakness than is preoperative strength.

Study Design

Prospective cohort study.

Methods

The quadriceps muscle strength of 37 patients (25 men, 12 women) was measured before reconstruction and 5 weeks and 6 months after surgery. Quadriceps surface electromyographic signals were recorded during all of the strength tests. Integrated electromyographic analysis and median frequency measurements were computed as deficits on the involved side. Patients also performed a single-legged hop test at the 6-month follow-up examination.

Results

The patients had significantly lower strength, integrated electromyographic analysis, and median frequency measurements on the involved side at all three time intervals. The best predictor of the quadriceps muscle strength deficit at 6 months was the combination of the preoperative median frequency deficit and the 5-week postoperative strength deficit. The best predictor of the hop test deficit at 6 months was the combination of preoperative deficits in integrated electromyographic analysis and median frequency.

Conclusion

Preoperative electromyographic indices of quadriceps muscle function and early postoperative strength were predictive of residual weakness and impaired function 6 months after reconstruction.
A Prospective, Randomized Evaluation of Arthroscopic Stabilization versus Nonoperative Treatment in Patients with Acute, Traumatic, First-Time Shoulder Dislocations
Authors: Bottoni Craig R. , Wilckens John H. , DeBerardino Thomas M. , D'Alleyrand Jean-Claude G. , Rooney Richard C. , Harpstrite J. Kimo , Arciero Robert A.
Published: July 2017

Background

Nonoperative treatment of traumatic shoulder dislocations leads to a high rate of recurrent dislocations.

Hypothesis

Early arthroscopic treatment for shoulder dislocation will result in a lower recurrence rate than nonoperative treatment.

Study Design

Prospective, randomized clinical trial.

Methods

Two groups of patients were studied to compare nonoperative treatment with arthroscopic Bankart repair for acute, traumatic shoulder dislocations in young athletes. Fourteen nonoperatively treated patients underwent 4 weeks of immobilization followed by a supervised rehabilitation program. Ten operatively treated patients underwent arthroscopic Bankart repair with a bioabsorbable tack followed by the same rehabilitation protocol as the nonoperatively treated patients. The average follow-up was 36 months.

Results

Three patients were lost to follow-up. Twelve nonoperatively treated patients remained for follow-up. Nine of these (75%) developed recurrent instability. Six of the nine have required subsequent open Bankart repair for recurrent instability. Of the nine operatively treated patients available for follow-up, only one (11.1%) developed recurrent instability.

Conclusions

Arthroscopic stabilization of traumatic, first-time anterior shoulder dislocations is an effective and safe treatment that significantly reduces the recurrence rate of shoulder dislocations in young athletes when compared with conventional, nonoperative treatment.
Open Repairs for the Treatment of Anterior Shoulder Instability
Authors: Gill Thomas J. , Zarins Bertram
Published: July 2017

Successful treatment of anterior instability of the shoulder requires a balance between restoring joint stability and minimizing loss of glenohumeral motion. The choice of treatment should be individualized on the basis of the patient's occupation and level of participation in sports, as well as on the degree of instability of the shoulder. Despite discussions to the contrary, there is no single “essential lesion,” as proposed by Bankart, that is responsible for recurrent anterior shoulder instability, although the Bankart lesion is by far the most important. The choice of operative treatment must be tailored to correct the abnormality that is identified at the time of surgery. A variety of promising arthroscopic techniques have been developed for the treatment of anterior shoulder instability; however, open stabilization remains the standard, especially for severe instabilities, revision procedures, and for athletes who participate in contact sports. This article will review the open surgical techniques used for treatment of anterior instability of the shoulder. Both current and historical operations will be discussed. Regardless of which procedure is chosen by a surgeon, the treatment should follow the guidelines taught by Rowe: anatomic dissection at the time of surgery, identification and repair of the lesions responsible for the instability, returning tissues to their anatomic locations, and early postoperative range of motion. By following these guidelines, the results of treatment of anterior instability of the shoulder can be optimized.
Patellar Tendon or Semitendinosus Tendon Autografts for Anterior Cruciate Ligament Reconstruction?
Authors: Ejerhed Lars , Kartus Jüri , Sernert Ninni , Köhler Kristina , Karlsson Jon
Published: July 2017

Background

There are well-known problems with the use of bone-patellar tendon-bone autografts for anterior cruciate ligament reconstruction, especially in terms of donor site morbidity. Hamstring tendon grafts have been increasingly used as an alternative, but there are very few controlled studies comparing the methods.

Hypothesis

Use of semitendinosus tendon grafts will cause less donor site morbidity and result in better knee-walking ability.

Study Design

Prospective randomized clinical trial.

Methods

Seventy-one patients who had a unilateral anterior cruciate ligament rupture underwent arthroscopic reconstruction with interference screw fixation and use of either bone-patellar tendon-bone or semitendinosus tendon graft. Outcome assessment was performed by physiotherapists not involved in the patients' care.

Results

At the 2-year follow-up, no differences were found in terms of the Lysholm score, Tegner activity level, KT-1000 arthrometer side-to-side laxity measurement, single-legged hop test, or International Knee Documentation Committee classification results. The knee-walking test was rated difficult or impossible to perform by 53% of the bone-patellar tendon-bone group and by only 23% of the semitendinosus graft patients, a significant difference.

Conclusions

The semitendinosus tendon graft is at least an equivalent option to the bone-patellar tendon-bone graft for anterior cruciate ligament reconstruction, and we recommend its use.
Three-Dimensional Tibiofemoral Kinematics of the Anterior Cruciate Ligament-Deficient and Reconstructed Knee during Walking
Authors: Georgoulis Anastasios D. , Papadonikolakis Anastasios , Papageorgiou Christos D. , Mitsou Argyris , Stergiou Nicholas
Published: July 2017

Background

It is possible that gait abnormalities may play a role in the pathogenesis of meniscal or chondral injury as well as osteoarthritis of the knee in patients with anterior cruciate ligament deficiency.

Hypothesis

The three-dimensional kinematics of anterior cruciate ligament-deficient knees are changed even during low-stress activities, such as walking, but can be restored by reconstruction.

Study Design

Case control study.

Methods

Using a three-dimensional optoelectronic gait analysis system, we examined 13 patients with anterior cruciate ligament-deficient knees, 21 patients with anterior cruciate ligament-reconstructed knees, and 10 control subjects with uninjured knees during walking.

Results

Normal patterns of knee flexion-extension, abduction-adduction, and internal-external rotation during the gait cycle were maintained by all subjects. A significant difference in tibial rotation angle during the initial swing phase was found in anterior cruciate ligament-deficient knees compared with reconstructed and control knees. The patients with anterior cruciate ligament-deficient knees rotated the tibia internally during the initial swing phase, whereas the others rotated externally.

Conclusions

Patients with anterior cruciate ligament-deficient knees experienced repeated episodes of rotational instability during walking, whereas patients with reconstruction experienced tibial rotation that is closer to normal.

Clinical Relevance

Repeated episodes of knee rotational instability may play a role in the development of pathologic knee conditions.
The Effect of Anterior Cruciate Ligament Deficiency and Functional Bracing on Translation of the Tibia Relative to the Femur during Nonweightbearing and Weightbearing
Authors: Beynnon Bruce D. , Fleming Braden C. , Churchill David L. , Brown Daniel
Published: July 2017

Background

Much of what is known about functional bracing is derived from studies of the knee during unweighted or weightbearing conditions, whereas little is known about the transition between these postures.

Hypothesis

Bracing the anterior cruciate ligament-deficient knee during nonweightbearing, throughout the transition to weightbearing, and during weightbearing reduces the abnormal translations of the tibia relative to the femur to within the limits of normal.

Study Design

Controlled laboratory study.

Methods

Subjects with chronic anterior cruciate ligament tears were studied with and without braces. Anteroposterior shear and compressive loads were applied to the knee, and translations of the tibia relative to the femur were measured while subjects were nonweightbearing, throughout the transition to weightbearing, and during weightbearing.

Results

Bracing the anterior cruciate ligament-deficient knee resulted in a significant reduction of anteroposterior laxity values, to a level within the limits of the normal knee during nonweightbearing and weightbearing postures. In contrast, when the anterior cruciate ligament-deficient knees transitioned from nonweightbearing to weightbearing, the anterior translation of the tibia relative to the femur was 3.5 times greater than in the normal knee, and bracing did not reduce this to within the limits of normal.

Conclusions

Bracing a knee with a chronic anterior cruciate ligament tear was effective in reducing abnormal anteroposterior laxity during nonweightbearing and weightbearing; however, braces were not effective in reducing the abnormal anterior translations produced by the change between these postures.

Clinical Relevance

This study explains why subjects with anterior cruciate ligament tears gain partial control of pathologic anteroposterior laxity with the use of a brace but may continue to experience abnormal translations during activity.
Knee Function after Anterior Cruciate Ligament Injury in Elite Collegiate Athletes
Authors: McAllister David R. , Tsai Albert M. , Dragoo Jason L. , McWilliams Justin , Dorey Frederick J. , Hame Sharon L. , Finerman Gerald A. M.
Published: July 2017

Background

Anterior cruciate ligament injuries are common in athletes, but there are few studies of long-term outcomes.

Hypothesis

Long-term knee function of anterior cruciate ligament-injured athletes is inferior to that of their uninjured teammates.

Study Design

Retrospective cohort study.

Methods

Thirty-three Division I-A athletes who had sustained an anterior cruciate ligament injury during their college career completed a series of questionnaires that assessed knee function and quality of life 2 to 14 years after injury. Their responses were compared with those of a matched cohort of their uninjured teammates.

Results

There were no differences in the mean Tegner scores, modified Lysholm scores, or in the scores of the SF-36 between groups. Sixteen anterior cruciate ligament-injured athletes scored A or B in the subjective portion of the International Knee Documentation Committee score and 17 scored C or D, whereas 24 control subjects scored A or B and 9 scored C or D, a statistically significant difference between groups. Five injured and 14 control athletes had participated at a professional or national team level after college.

Conclusions

Quality of life of elite collegiate athletes who sustained an anterior cruciate ligament injury was not significantly different from that of their uninjured teammates, but knee function differed between groups.
Relaxin Receptors in the Human Female Anterior Cruciate Ligament
Authors: Dragoo Jason L. , Lee Richard S. , Benhaim Prosper , Finerman Gerald A. M. , Hame Sharon L.
Published: July 2017

Background

Noncontact anterior cruciate ligament injuries occur two to eight times more often in women than in men. Changes in ligament laxity and strength have been associated with female hormones such as relaxin.

Hypothesis

Relaxin receptors are present within the female anterior cruciate ligament.

Study Design

Controlled laboratory study.

Methods

Remnants of anterior cruciate ligament were harvested from five women and five men undergoing routine ligament reconstruction. Relaxin was biotinylated and analyzed for biologic activity with use of the mouse interpubic ligament bioassay. Immunohistochemical localization of relaxin receptors was performed with appropriate negative controls and competitive binding assays to determine receptor specificity and saturability.

Results

Anterior cruciate ligament sections from women but not from men showed uniform specific binding that was limited to synovial lining cells, stromal fibroblasts, and cells lining blood vessels. Specific binding was confirmed in the presence of a 2000-fold excess of human insulin, the structural homolog of relaxin, and competitive inhibition was demonstrated in the presence of a 2000-fold excess of unlabeled relaxin.

Conclusions

Relaxin exhibits specific saturable binding in the female anterior cruciate ligament, where specific relaxin receptors were present.

Clinical Relevance

The high incidence of anterior cruciate ligament rupture in female athletes may be partially explained by the effects of relaxin.
Back Pain in Former Intercollegiate Rowers
Authors: Teitz Carol C. , O'Kane John W. , Lind Bonnie K.
Published: July 2017

Background

Research has shown that 32% of intercollegiate rowers develop back pain during their college career.

Hypothesis

Rowers who develop back pain in college are more likely than the general population to have back pain later in life.

Study Design

Survey.

Methods

Surveys from 1561 former intercollegiate rowing athletes were analyzed. Subjects who completed the surveys had graduated from college at a mean and median of 13 years previously, with a range of 0 to 20 years between graduation and completion of the survey. The survey was designed to determine the presence of back pain and its severity before, during, and after intercollegiate rowing. Back pain was defined as pain that lasted at least 1 week.

Results

Age was a significant predictor of back pain after college. Nevertheless, the lifetime prevalence of back pain in former intercollegiate rowers was no different from that of the general population (51.4% versus 60% to 80%). However, rowers who developed back pain in college had more subsequent back pain than rowers who were asymptomatic in college (78.9% versus 37.9%). Rowers who were asymptomatic in college had significantly lower rates of back pain as they aged than did the general population. The mean severity of current back pain was 3.5 ± 1.9 on a scale of 1 to 10.

Conclusions

Intercollegiate rowers are no more likely than the general population to have back pain later in life.
Effects of Bone Block Position and Orientation within the Tibial Tunnel for Posterior Cruciate Ligament Graft Reconstructions
Authors: Markolf Keith , Davies Mark , Zoric Bojan , McAllister David
Published: July 2017

Background

Posterior laxity occurring after posterior cruciate ligament reconstruction with a tibial tunnel could be related to thinning and permanent elongation of the graft as it is cyclically loaded in vivo.

Hypothesis

The orientation and position of the bone block within the tibial tunnel will have a significant effect on thinning and elongation of the graft after cyclic loading.

Study Design

Controlled laboratory study.

Methods

In test series 1 (27 fresh-frozen graft pairs), all bone blocks were positioned flush with the posterior opening of the tibial tunnel; 1 graft was oriented with the bone block facing posteriorly, whereas its pair was tested with the bone block facing anteriorly. In test series 2 (20 graft pairs), all grafts were oriented with the bone block facing posteriorly; 1 graft had the bone block positioned flush with the posterior tunnel opening, whereas its pair was tested with the bone block recessed 1 cm from the posterior opening.

Results

In series 1, 3 of 27 grafts with posterior bone block orientations failed at the tunnel edge before 2000 cycles of testing could be completed; all specimens with anterior bone block placements survived the testing intact. In series 2, 3 of 20 grafts with recessed bone blocks failed at the tunnel edge, whereas all those with flush bone blocks survived.

Conclusions

The best position for the bone block of a bone-patellar tendon-bone graft was flush with the posterior tunnel opening with the bone block facing anteriorly in the tibial tunnel.
Early Weightbearing and Ankle Mobilization after Open Repair of Acute Midsubstance Tears of the Achilles Tendon
Authors: Maffulli Nicola , Tallon Cheryl , Wong Jason , Peng Lim Kim , Bleakney Robert
Published: July 2017

Purpose

To study the effects of early weightbearing and ankle mobilization after acute repair of ruptured Achilles tendon.

Study Design

Comparative longitudinal study.

Methods

Patients in group 1 were postoperatively immobilized with their ankle in gravity equinus, they were encouraged to bear weight on the operated limb as soon as possible to full weightbearing, and they received a single cast change at 2 weeks, with the ankle accommodated in an anterior splint in a plantigrade position, allowing the ankle to be plantar flexed fully but not dorsiflexed above neutral. Patients in group 2 were immobilized with their ankle in full equinus with a cast change at 2 weeks, when the ankle was immobilized in mid equinus, and at 4 weeks, when the ankle was immobilized in a plantigrade position, and they were advised to bear weight.

Results

Patients in group 1 attended fewer outpatient visits, completely discarded their crutches at an average of 2.5 weeks, and more were satisfied with the results of surgery. At ultrasonography, the average thickness of the repaired tendon was 12.1 mm, with no difference in the thickness of the ruptured tendon regardless of postoperative management. There was no significant difference in isometric strength between the two groups.

Conclusions

Early weightbearing with the ankle plantigrade is not detrimental to the outcome of repair after acute rupture of the Achilles tendon and shortens the time needed for rehabilitation. However, strength deficit and muscle atrophy are not prevented.
Magnetic Resonance Imaging of the Asymptomatic Shoulder of Overhead Athletes
Authors: Connor Patrick M. , Banks David M. , Tyson Alan B. , Coumas James S. , D'Alessandro Donald F.
Published: July 2017

Background

Although several studies have described magnetic resonance imaging findings in shoulders of asymptomatic volunteers, no such investigation has been performed on asymptomatic dominant and nondominant shoulders of elite overhead athletes.

Hypothesis

Asymptomatic dominant shoulders of elite overhead athletes may have a higher incidence of magnetic resonance imaging abnormalities than either their nondominant shoulder or shoulders of asymptomatic volunteers.

Study Design

Prospective cohort study.

Methods

Detailed magnetic resonance imaging scans of asymptomatic dominant and nondominant shoulders of elite overhead athletes were obtained. Three experienced musculoskeletal radiologists interpreted each scan for multiple variables, including rotator cuff appearance. Images from a surgical control group were intermixed to assess accuracy and control for observer bias. A 5-year follow-up interview was performed to determine whether magnetic resonance imaging abnormalities found in the initial stage of the study represented truly clinical false-positive findings or symptomatic shoulders in evolution.

Results

Eight of 20 (40%) dominant shoulders had findings consistent with partial- or full-thickness tears of the rotator cuff as compared with none (0%) of the nondominant shoulders. Five of 20 (25%) dominant shoulders had magnetic resonance imaging evidence of Bennett's lesions compared with none (0%) of the nondominant shoulders. None of the athletes interviewed 5 years later had any subjective symptoms or had required any evaluation or treatment for shoulder-related problems during the study period.

Conclusions

Magnetic resonance imaging alone should not be used as a basis for operative intervention in this patient population.
Effect of a Prophylactic Brace on Wrist and Ulnocarpal Joint Biomechanics in a Cadaveric Model
Authors: Grant-Ford Marsha , Sitler Michael R. , Kozin Scott H. , Barbe Mary F. , Barr Ann E.
Published: July 2017

Background

Wrist pain from repetitive dorsiflexion and compression during pommel horse exercises is common among male gymnasts.

Purpose

To determine the biomechanical effects of a prophylactic wrist brace on the wrist and ulnocarpal joints during mechanical loading in a cadaveric model.

Hypothesis

The lateral wedge of the palmar pad of the brace will compensate for positive ulnar variance, distributing contact forces more evenly across the radioulnar carpal joint.

Study Design

Controlled laboratory study.

Methods

Six male and six female fixed cadaveric forearm-wrist specimens were subjected to a 32.13-kg compressive load applied through the long axis of the pronated forearm with a dorsiflexed wrist in contact with a support surface. Wrist joint dorsiflexion angle and ulnocarpal joint intraarticular peak pressure were assessed under three brace conditions: Ezy ProBrace with and without palmar pad and a nonbraced control.

Results

Wrist joint dorsiflexion angle was significantly reduced by the Ezy ProBrace with and without the palmar pad. However, ulnocarpal joint intraarticular peak pressure was reduced only by the brace with pad.

Conclusion

Prevention of pathologic wrist changes requires intervention in pressure attenuation, which was achieved with the Ezy ProBrace with palmar pad.

Clinical Relevance

This brace may decrease the cumulative effects of repetitive stress of pommel horse exercise training.
Osteochondritis Dissecans: Wilson's Sign Revisited
Authors: Conrad Jeffrey M. , Stanitski Carl L.
Published: July 2017

Background

In 1967, Wilson described a clinical sign that he thought was diagnostic of medial femoral osteochondritis dissecans. He postulated that impingement of the tibial eminence on the osteochondritic lesion caused pain and a resultant compensatory lateral rotation during gait. He described reproducing the pain by internally rotating the patient's tibia during knee extension between 90° and 30° of flexion and then relieving that pain by externally rotating the tibia. He correlated healing of the lesion with conversion of the sign from positive to negative.

Purpose

To assess the validity of Wilson's assertions.

Study Design

Retrospective clinical and radiographic case analysis.

Methods

Case records from 17 juvenile patients (ages 9 to 12) and 15 adolescent patients (ages 13 to 17) with medial femoral osteochondritis dissecans were reviewed for the presence or absence of Wilson's sign at initial and subsequent visits. Results: Of the 32 patients, 24 (75%) with radiographically evident osteochondritis dissecans at the initial visit had negative signs. The remaining eight patients with positive signs had conversion of the sign to negative with lesion resolution.

Conclusions

In this series, Wilson's sign was of minimal clinical diagnostic value. When positive, the sign is useful as a clinical monitor during treatment.
The Anatomy of the Deep Infrapatellar Bursa of the Knee
Authors: LaPrade Robert F.
Published: July 2017

Disorders of the deep infrapatellar bursa are important to include in the differential diagnosis of anterior knee pain. Knowledge regarding its anatomic location can aid the clinician in establishing a proper diagnosis. Fifty cadaveric knees were dissected, and the deep infrapatellar bursa had a consistent anatomic location in all specimens. The deep infrapatellar bursa was located directly posterior to the distal 38% of the patellar tendon, just proximal to its insertion on the tibial tubercle. There was no communication to the knee joint. Its average width at the most proximal margin of the tibial tubercle was slightly wider than the average distal width of the patellar tendon. It was found to be partially compartmentalized, with a fat pad apron extending down from the retropatellar fat pad to partially divide it into anterior and posterior compartments. The recommended approach to this bursa, either for aspiration, injection, or surgery, is along the lateral edge of the patellar tendon just proximal to the tibial tubercle.
The Natural History of Bone Bruises
Authors: Miller Mark D. , Osborne John R. , Gordon Wade T. , Hinkin Daniel T. , Brinker Mark R.
Published: July 2017

We conducted a prospective study to evaluate bone bruises, or trabecular microfractures, associated with isolated medial collateral ligament injuries. Magnetic resonance imaging was performed on 65 patients with isolated medial collateral ligament injuries determined by physical examination and imaging studies. Of these 65 patients, 29 (45%) had associated trabecular microfractures. Follow-up images were completed at various intervals on 24 of these 29 patients (83%). Complete resolution of these lesions was observed in all cases. This process appears to occur as a result of gradual diffusion over a period of 2 to 4 months. Bone bruises associated with medial collateral ligament injuries are approximately one-half as common as bone bruises associated with anterior cruciate ligament injuries. However, medial collateral ligament-associated trabecular microfractures may be a better natural history model because these injuries are treated nonoperatively.
A Correlation Between Shoulder Laxity and Interfering Pain in Competitive Swimmers
Authors: McMaster William C. , Roberts Andrew , Stoddard Terry
Published: July 2017

Shoulder pain in the swimming athlete that interferes with effective training is serious and may result in decreased performance. Based on the hypothesis that shoulder laxity is an important factor in shoulder pain, this study of 40 senior national and elite swimmers was undertaken. A questionnaire identified those athletes currently suffering from such pain. Shoulder laxity was assessed using standard clinical tests, from which a laxity score was derived. A statistically significant correlation was identified between the shoulder laxity score and the presence of interfering shoulder pain, confirming the hypothesis of the study. These results have direct implications for training the symptomatic athlete.
Contact Pressures at Osteochondral Donor Sites in the Knee
Authors: Simonian Peter T. , Sussmann Patrick S. , Wickiewicz Thomas L. , Paletta George A. , Warren Russell F.
Published: July 2017

The purposes of this study were to determine whether any of the commonly recommended osteochondral donor sites are nonarticulating throughout a functional range of knee motion, and to determine the differential contact pressures for these sites. Ten commonly recommended sites for osteochondral harvest were evaluated with pressure-sensitive film through a functional range of motion with a model that simulated nonweightbearing resistive extension of the knee. All 10 donor sites demonstrated a significant contact pressure through 0° to 110° of knee motion. The different color density measurements between donor sites were also significant. Although donor sites 1, 2, 9, and 10 demonstrated significantly less contact pressure than the sites with the greatest contact pressure, the difference in mean pressures was small. No osteochondral donor site tested was free from contact pressure. It is currently unknown whether articular contact at these osteochondral donor sites will lead to degenerative changes or any other problems.