bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic posterior shift test
Authors: Shelbourne K. Donald , Benedict Fred , McCarroll John R. , Rettig Arthur C.
Published: June 2007

The dynamic posterior shift test, a clinical method for evaluating both straight posterior instability and pos terolateral rotatory instability, (PLRI), is a simple, dy namic, and reliable (reproducible) test that serves as an adjuvant to other clinical tests designed to evaluate an injury or insufficiency of posterior structures in the knee. The examiner maintains the hip at near 90° of flexion to control rotation of the femur while slowly extending the knee passively. The hamstrings should be stretched to maintain their tightness. The tightened hamstrings assist gravity in subluxating the tibia posteriorly; they also provide dynamic axial loading to the joint as the knee is extended. In knees with posterior instability, the posteriorly subluxated tibia suddenly reduces as the knee joint nears full extension, and a jerk or "clunk" is felt by both the patient and the examiner. Thus, the patient's feeling of instability is reproduced by the test. We have used the dynamic posterior shift test for 5 years (as an adjuvant in our physical examination) to evaluate signs of posterior instability of the knee. Not only is the test reliable, but it is more definitive than other tests in evaluating straight posterior instability and PLRI. It is easy to perform and the results are reproducible. Because this test is dynamic rather than passive, it enhances the accuracy of evaluating poste rior instability of the knee.
Wrist pain syndrome in the gymnast
Authors: Mandelbaum Bert R. , Bartolozzi Arthur R. , Davis Craig A. , Teurlings Luc , Bragonier Bruce
Published: June 2007

Gymnast wrist pain syndrome presents a difficult diag nostic and therapeutic challenge. It is common and debilitating among gymnasts, resulting in a reduction in training and performance, and may be the result of a response to repetitive trauma during the period of growth and development. This study was undertaken to define and characterize factors contributing to the causes and development of gymnast wrist pain and to establish an effective means of systematic and compre hensive evaluation and treatment.

Thirty-eight collegiate gymnasts (20 UCLA: 9 female, 11 male; 18 NCAA: all male) were evaluated by radio graph and questionnaire. Seventy-five percent (22) of the males and 33% (3) of the females had had wrist pain for at least 4 months. The UCLA males averaged 2.82 ± 1.94 mm positive ulnar variance; this was sig nificantly greater than that of the NCAA males, who averaged 1.28 ± 1.02 mm (P < 0.02). The UCLA females averaged 1.44 ± 1.88 mm positive ulnar vari ance. All of the gymnasts had significantly greater variance than had the controls, who averaged -0.52 mm (P < 0.0001). The pommel horse routine was consistently responsible for wrist pain among the males.

Anatomical and histological correlation of cryosec tions with magnetic resonance imaging (MRI) was per formed to establish the usefulness of MRI in the diag nosis of wrist pain. MRI was able to differentiate the complex transitions between cortical and trabecular bone, articular surfaces, the ligaments, and the trian gular fibrocartilage (TFC) complex of the wrist joint. A therapeutic algorithm was established to facilitate the evaluation and management of gymnast wrist pain.

Arthroscopic surgery was successful, and arthroscopic findings correlated well with those of MRI and arthrog raphy. Prospective studies are now underway in the pediatric and adolescent population to define further the causes and development of wrist pain problems in gymnasts.
Load sharing and graft forces in anterior cruciate ligament reconstructions with the Ligament Augmentation Device
Authors: Hanley Patrick , Lew William D. , Lewis Jack L. , Hunter Robert E. , Kirstukas Steven , Kowalczyk Curtis
Published: June 2007

Buckle transducers were used to directly measure load sharing and overall force in three segment (semitendi nosus, gracilis, Ligament Augmentation Device) and two segment (patellar tendon, LAD) composite ACL grafts during the application of anteriorly directed loads to a series of five fresh knee specimens with a pneu matic load apparatus. The total graft forces generated in the two segment and three segment composite reconstructions during this immediate postoperative state were highly variable when compared to the normal ACL in each specimen, and were irreproducible among the five specimens. Load sharing among the graft com ponents occurred and was also variable in both recon structions, with this variation being greater in the three segment graft. The LAD carried an average of 45% of the total graft force in the three segment graft and 28% in the two segment graft. Further work is required to clarify the source of the variability in the total graft force and load sharing observed in this study.
Four to ten year followup of unreconstructed anterior cruciate ligament tears
Authors: Pattee Gary A. , Fox James M. , Del Pizzo Wilson , Friedman Marc J.
Published: June 2007

Both operative and nonoperative methods have been advocated for the treatment of ACL tears. However, the optimum management of this injury remains contro versial. In the present study, patients treated nonoper atively were evaluated retrospectively 4 to 10 years after ACL tears were documented by arthroscopy and by mild to moderate pivot shifts under anesthesia.

Forty-nine patients who underwent arthroscopic eval uation of the knee between 1976 and 1982 were found to have complete tears of the ACL. A mild to moderate pivot shift was present under anesthesia. One or both menisci were torn in two-thirds of the knees, requiring partial meniscectomies. The average age of the patients was 27 years (range, 16 to 46 years). Because of persistent disabling instability, 9 patients (18%) under went late ACL reconstruction. The remaining 40 pa tients were evaluated at an average of 5.6 years after documentation of the tear (range, 4 to 10 years).

At followup, 25 (62%) of the 40 patients had satisfac tory subjective results. Eight of the patients (20%) had returned to their preinjury level of athletic activities without restrictions, and 10 (25%) functioned at the same level but with symptoms, some patients requiring bracing. Seventeen patients (43%) had diminished their level of sports activities, while 5 patients (12%) had given up all sports. Only 2 patients required late men iscectomies.

On physical examination, 27 patients (87%) had pivot shifts. Instrumented laxity testing revealed an injured to normal difference of 3.1 mm with a 20 pound force. Radiographic studies were interpreted as normal in 35% of the knees, whereas 65% demonstrated mild degenerative changes. Overall, objective results were satisfactory in only 7 (23%) of the 31 patients, although 19 (61 %) were satisfied with their functional results.

Numerous procedures are available for stabilizing the ACL insufficient knee. With improvement in our ability to diagnose an acute ACL tear, management must be based not only on the initial clinical findings, but on the patient's level of activity and functional expectations. Although only slightly more than 60% of the patients had satisfactory subjective results, many had adapted quite well to their ultimate functional disability through modification of activities. Few patients, however, re turned unrestricted to their preinjury level of function.
Injuries in elite pair skaters and ice dancers
Authors: Smith Angela D. , Ludington Ronald
Published: June 2007

Figure skating coaches have become concerned about the increasing number of injuries among competitive skaters, particularly pair skaters. This study prospec tively examines the incidence, severity, and cause of injuries sustained by a group of elite pair skaters and ice dancers. Thirty-three serious injuries, causing the skater to alter training significantly or to cease training completely for at least 7 consecutive days, were re corded over a 9 month period. Female senior pair skaters reported an average of 1.4 serious injuries, and other groups averaged greater than 0.5 serious injury per skater. The lower extremities were injured most frequently, and 7 of the 33 serious injuries were directly related to the skating boot. Eleven serious injuries were caused by lifts. Few of the serious injuries appeared preventable.

Changes in boot design and the training for lifting maneuvers should be initiated and studied prospec tively to attempt to reduce the unacceptably high injury rate among elite pair skaters and ice dancers.
A musculoskeletal approach to the preparticipation physical examination
Authors: Kibler W.B. , Chandler T. Jeff , Uhl Tim , Maddux Robin E.
Published: June 2007

Preparticipation physical examinations provide infor mation concerning an athlete's ability to participate safely in sports. By collecting information specific to the musculoskeletal system in addition to that from a general medical examination, information can be gained that may improve performance and help prevent certain injuries. Two thousand one hundred seven athletes from a variety of sports from the junior high to the college level were examined using specific tests for flexibility, strength, and endurance. Females were sig nificantly more flexible than were males on all flexibility measurements, and males were significantly stronger than were females on all strength measurements. Up per-body athletes were tighter in dominant side internal rotation and significantly looser in dominant side exter nal rotation. Lower-body athletes, especially females, were significantly tighter in the leg muscles. These results indicate that the adaptations of the musculo skeletal system are sport specific and depend on the body area that is placed under stress.
Corticosteroids and anterior cruciate ligament repair
Authors: Vargas Joseph H. , Ross Dennis G.
Published: June 2007

A two group (N = 62) historical comparative design was used to study patients undergoing ACL repair. This retrospective study examined the effect of corti costeroids on analgesic use during hospitalization, the length of hospitalization, and the 1 st day of ambulation. Thirty-one ACL repair patients receiving a standard protocol of intravenous intraoperative and oral post operative corticosteroids (experimental group) were compared to 31 similarly aged ACL repair patients who received similar surgical repair and medical therapy but no steroids (control group). Patients with chronic dis ease or current steroid use were not included in the study. Even though the experimental group had a higher incidence of coincidental injuries of the knee (meniscal and/or collateral ligament injuries), the group used 50% less analgesics while hospitalized (x = 14.19 doses) than the control group (x = 21.29). Similarly, the experimental group had a length of stay 59% less long (x = 3.61 days versus x = 5.74 days) and ambulated 38% more quickly (x = 1.93 days versus x = 2.67 days) than the control group. No differences were noted between groups in incidence of postoperative infection or problems with wound healing after a 1 year followup.
Metacarpal fractures in the athlete
Authors: Rettig Arthur C. , Ryan Ramon , Shelbourne K. Donald , McCarroll John R. , Johnson Frank , Ahlfeld Steven K.
Published: June 2007

Fifty-six fractures of the metacarpal occurring in 53 athletes were studied from September 1985 to Decem ber 1986, regarding mechanism of injury, type of frac ture, type of treatment, and time lost from sport. Age range of the patients was 8 to 28 years with greater than 77% being in the 14 to 18 year age range, the high school athlete. Twenty-nine of the fractures oc curred in football, 14 in basketball, and the remainder were divided between various other sports. The most common mechanism of injury involved falls or hitting an object such as a helmet or another player. Fractures were evenly divided regarding which digit was involved in football, whereas most basketball injuries occurred in the fourth and fifth metacarpal. Fractures were ana lyzed as to type of radiographic appearance and this was correlated with time lost from competition or par ticipation. No significant difference among fracture type regarding time lost was noted.

Forty-six of the fractures (82%) were minimally dis placed or undisplaced and were treated by means of simple casting and/or splinting whereas 10 were dis placed. Two of the 10 underwent closed reduction and casting; 3 underwent closed reduction and percuta neous pin fixation; and 5 (9%) underwent open reduc tion internal fixation using AO type plates and screws. All fractures healed primarily clinically and radiographi cally.

The average time lost from practice or competition in this group overall was 13.7 days, (range, 0 to 56 days). Average time lost from basketball was 19.8 days and from football 10.63 days overall. Average time lost from sport in stable fractures treated with casting or splinting was 12.3 days. Those undergoing open reduction in ternal fixation with plate and screws averaged 13.6 days.

We concluded that most metacarpal fractures in the athlete can be treated by closed means with a fairly rapid return to sport, depending on type of sport and position played. In certain displaced fractures, open reduction internal fixation can expedite early return to function and return to sport.
Human lymphocyte reaction to freeze-dried allograft and xenograft ligamentous tissue
Authors: Pinkowski John L. , Reiman Paul R. , Chen Suio-Ling
Published: June 2007

Decisions made before reconstruction of the ACL in clude patient selection, choice of operative procedure, and selection of proper reconstructive material. Re search in the use of allograft material for reconstructive grafts is of great interest for many reasons, including the advantage of not violating the patient's normal anatomy for donor tissue. A group of eight patients who received arthroscopically inserted freeze-dried bone-patellar tendon-bone allograft tissue for ACL re construction were selected for a prospective study. These patients were matched against a group of four autograft controls.

Immunologically, the lymphocyte blast transformation test was used to evaluate the host reaction to implanted donor graft. Lymphocytes drawn from each patient were tested for their reaction against a panel of human allograft tendon and goat xenograft tendon homoge nates. A stimulation index of greater than 3 was con sidered a positive reaction. It was hypothesized that a consistent lack of antigenicity would be observed with allograft extracts and that an antigenic reaction would be observed with the xenograft extracts.

Six patients (75%) showed an immunologic reaction to the goat xenograft, and four patients (50%) showed an immunologic reaction to at least one human allograft test cell after allograft insertion. One patient had such an intense clinical immunologic response that she re quired removal of the allograft. All four of the autograft controls had a nonimmunogenic response to testing, as had been expected. Although the numbers of this study are small, it is important to point out that an immunologic response to freeze-dried allograft tendon appears to be occurring, in contrast to previous re search in animals.
The in vivo force-velocity relationship of the knee flexors and extensors
Authors: Prietto Carlos A. , Caiozzo Vincent J.
Published: June 2007

Previous studies have compared the torque production of the knee flexors and extensors and developed a "hamstring-quadricep" ratio. Collectively, these studies indicate that the ratio of strength between the knee flexors and extensors is a function of test speed, with the ratio increasing at the faster test speeds. Unfortu nately, these studies have employed the peak torque isokinetic method for making measurements. This tech nique suffers from a number of problems that are biomechanical and physiological in nature. Conse quently, in this study, we employed comparisons of the in vivo force-velocity relationship using an angle-specific method and a gravitational correction factor to more accurately determine flexor-extensor ratios and to bet ter describe any variations occurring as a function of test speed. Nine male subjects volunteered to partici pate in this study. Each of the subjects participated in two test sessions. Subjects were tested at six angular velocities of 0, 48, 96, 144, 192, 240 deg/sec. At these respective test speeds, the mean flexor torques were 95.0, 94.8, 84.1, 66.2, 56.2, and 49.2 Nm, respectively. The corresponding values for the knee extensors were 252.2, 246.5, 220.7, 184.5, 161.9, and 146.4 Nm. Normalization of these torque-velocity relationships demonstrated that the in vivo force-velocity relation ships of the two muscle groups are similar at slow speeds, but become disparate at higher velocities. When examining flexor-extensor torque ratios at the various test speeds, it was found that there were significant differences (P < 0.01). The mean values for the flexors expressed as a percent of knee extensor torque were 37.5%, 38.2%, 38.2%, 35.9%, 34.5%, and 33.4% at speeds of 0, 48, 96, 144, 192, and 240 deg/ sec, respectively.
The Bankart repair illustrated in cross-section
Authors: Blasier Ralph B. , Bruckner James D. , Janda David H. , Alexander A. Herbert
Published: June 2007

The Bankart repair for chronic anterior shoulder insta bility effectively addresses the pathologic components responsible for repeated dislocation or subluxation. However, contrary to popular belief, the Bankart repair does not precisely restore the premorbid anatomy. The capsule is reattached to the boney rim of the anteroin ferior glenoid deep to and lateral to the torn cartilagen ous labrum, thus excluding the labrum from the joint anteriorly. This was demonstrated by cross-sectional cadaver dissections performed to illustrate this complex surgical anatomy to orthopaedic residents in training. In addition, when correlated with double-contrast com puterized axial tomography, we noted five predominant patterns of anatomical lesions which by common use have been collectively termed the "Bankart lesion." These are: 1) the rare "classic" Bankart lesion in which the cartilagenous labrum and capsular origin are torn from the glenoid rim; 2) the capsule stripped from the scapular neck and the labrum detached from the gle noid rim remaining fixed to the overlying capsule; 3) the capsule stripped from the scapular neck and the labrum separated from the glenoid rim, but separately; 4) the labrum abraded away and no longer radiographically detectable; and 5) glenoid rim fracture.
Electromyography in voluntary posterior instability of the shoulder
Authors: Pande Patricia , Hawkins Richard , Peat Malcolm
Published: June 2007

Electromyographic (EMG) activity of selected shoulder girdle muscles was analyzed during voluntary posterior subluxation of the glenohumeral joint in four subjects. Although there was a great deal of variation in the muscle activation patterns during subluxation, subjects either pushed the humeral head backwards with the anterior muscles (deltoid, biceps) or pulled the humeral head backwards with the infraspinatus and/or posterior deltoid. In all cases, inhibition of the scapular rotators and winging of the scapula accompanied this maneu ver. The method used in this study is presented as an objective technique for quantifying EMG activity during subluxation and relocation phases of shoulder instabil ity.
A mechanical model of metatarsal stress fracture during distance running
Authors: Gross Ted S. , Bunch R.P.
Published: June 2007

A model of metatarsal mechanics has been proposed as a link between the high incidence of second and third metatarsal stress fractures and the large stresses measured beneath the second and third metatarsal heads during distance running. Eight discrete piezo electric vertical stress transducers were used to record the forefoot stresses of 21 male distance runners. Based upon load bearing area estimates derived from footprints, plantar forces were estimated. Highest force was estimated beneath the second and first metatarsal head (341.1 N and 279.1 N, respectively). Considering the toe as a hinged cantilever and the metatarsal as a proximally attached rigid cantilever allowed estimation of metatarsal midshaft bending strain, shear, and axial forces. Bending strain was estimated to be greatest in the second metatarsal (6662 με), a value 6.9 times greater than estimated first metatarsal strain. Predicted third, fourth, and fifth metatarsal strains ranged be tween 4832 and 5241 με. Shear force estimates were also greatest in the second metatarsal (203.0 N). Axial forces were highest in the first metatarsal (593.2 N) due to large hallux forces in relationship to the remain ing toes. Although a first order model, these data highlight the structural demands placed upon the sec ond metatarsal, a location of high metatarsal stress fracture incidence during distance running.
The effect of volleyball playing on the knee extensor mechanism
Authors: Kujala U.M. , Aalto T. , Österman K. , Dahlstrom S.
Published: June 2007

The knee extensor mechanism was examined in 32 male competitive volleyball players (Group V) and in a control group of 49 young adult males (Group C) to evaluate the effects of previous jumping activity on the knee extensor mechanism. Several variables were re corded by means of a structured questionnaire, and by clinical and radiographic examination.

The amount of physical activity from the age of 7 years onward was significantly greater in Group V than in Group C. The incidence of anterior knee pain during the year preceding the examination was higher in Group V (31%) than in Group C (6%;P < 0.01). The most common reason for anterior knee pain in Group V was so-called "jumper's knee." No significant difference be tween the groups was found in the incidence of clinical symptoms and signs of patellar chondromalacia. There were radiologically detectable soft tissue calcifications at the upper or lower pole of the patella or anterior to the patella in 38% of the subjects in Group V, but no such calcifications were seen in Group C ( P < 0.001). However, persistent symptoms did not correlate with the calcifications. Group V subjects had a slight but significant trend to patella alta when compared to Group C ( P < 0.05) according to the Blackburne and Peel index.
The importance of the meniscus in unstable knees
Authors: Sommerlath Karola
Published: June 2007

This study analyzes differences in knee function in ACL deficient knees with different meniscus status. Eighty patients, 12 women and 68 men, were matched in four groups according to sex, age, knee injuries, and follow up time. Group I had two intact menisci; Group II, one meniscus successfully repaired; Group III, one menis cus removed; and Group IV, both menisci removed.

The ACL was repaired acutely or reconstructed later in most cases and other significant ligament injuries were treated. All patients were reexamined clinically 6 to 8 years after injury. Knee function was recorded using the Lysholm knee function score. Activity level before injury and at followup was rated with the Tegner scale. Stability was tested and weightbearing roentgen ograms were taken.

There was a higher frequency of ACL reconstructions in Groups I and II, but instability was the same in all groups. No difference was found in Lysholm score (range, 86 to 92). The activity level was higher in Group IV at followup. A lower frequency of motion impairment was found in Group III, (20% versus 50%). Subjective evaluation was similar and positive in all groups. Group I had six meniscus ruptures during the follow-up period. In Group II three of the repaired menisci were removed, as were two of the contralateral menisci in Group III. Roentgenograms, available in 55 of 80 cases, showed osteoarthritis in 65%. There were no differences in the frequency of osteoarthritis among the first three groups, but Group IV had a higher incidence of osteoar thritic changes. Osteoarthritis did not result in lower knee function, poorer subjective evaluation, or in creased impairment of motion. Of the patients with osteoarthritis, more maintained their preinjury activities. In terms of function and osteoarthritis, instability and chosen activity level seemed to be of prognostic impor tance.
Electromyographic shoulder activity in men and women professional golfers
Authors: Jobe Frank W. , Perry Jacquelin , Pink Marilyn
Published: June 2007

Men and women both enjoy the game of golf. Special considerations are made for women, such as the courses on the professional tours. Thus, one can ask what differences might exist between men and women golfers. This study compares the electromyographic firing patterns of normal shoulder musculature in men and women professional golfers. Eight shoulder mus cles (pectoralis major, latissimus dorsi, supraspinatus, infraspinatus, subscapularis, anterior, middle and pos terior deltoids) were studied using indwelling electro myography.

A visual analysis revealed that women tended to have slightly more activity during the takeaway and forward swing phases, and the men tended to have more activ ity during acceleration and follow-through. However, an independent two-tailed t-test ( P = 0.05) showed these differences not to be statistically significant.

This finding is in keeping with injury incidence data from the LPGA Tour, PGA Tour, and Senior PGA Tour, which showed that all three tours have a similar inci dence of shoulder injuries. This study does not compare the relative strength of men and women, however.
Kinematics of active knee extension after tear of the anterior cruciate ligament
Authors: Jonsson Håkan , Kärrholm Johan , Elmqvist Lars-Gunnar
Published: June 2007

Three-dimensional movements of the knees in 13 pa tients with unilateral old tears of ACLs were studied during extension. Roentgen stereophotogrammetric methods were used to measure tibial movements in the injured and the intact knees. Reduced internal rotation and adduction were recorded at the end of extension on both sides. The injured knees displayed increased anterior and distal displacements of the tibial intercon dylar eminence. Abnormal tibial displacements in our patients indicate that the absence of the ACL is not completely compensated for during active extension past 30°; close to the extended position, the tibial movements tend to normalize.
Quantification of the perfusion of the anterior cruciate ligament and the effects of stress and injury to supporting structures
Authors: Dunlap Janet , McCarthy John A. , Joyce Michael E. , Ogata Kosuke , Shively Robert A.
Published: June 2007

The perfusion of the normal ACL was quantitated using the hydrogen washout technique in a canine model. This was compared to the perfusion of the synovium in the suprapatellar pouch. Changes in the ACL perfusion were quantitated after the application of anterior stress, division of the infrapatellar fat pad, and dissection of the synovium enveloping the ACL. The ACL is relatively hypovascular, with one-half the blood flow of the sy novium of the suprapatellar pouch. Application of an anterior stress diminishes the blood flow to the ACL to one-fifth of the baseline value, an effect which is re versible. Division of the infrapatellar fat pad causes a two-fold decrease in perfusion to the ACL, whereas dissection of the enveloping synovium results in a com plete cessation of blood flow.
An epidemiologic investigation of injuries affecting young competitive female gymnasts
Authors: Caine Dennis , Cochrane Barbara , Caine Caroline , Zemper Eric
Published: June 2007

A prospective study of injuries affecting 50 highly com petitive young female gymnasts was conducted over a period of 1 year. Many of the findings of this investi gation were consistent with previous studies and sug gest particular injury trends in women's gymnastics. These results included injury location, injury severity, nature of onset, event, and activity at the time of injury. Some of the descriptive results, however, provided information that was heretofore unreported or incon sistent with previous investigations. These findings in volved injury rate, reinjury rate, time loss, injury type, hours of practice, and incidence of physician-seen in juries. Some of these findings were disturbing and echo concerns registered in the professional literature. In particular, the reinjury rate is alarming and points to the need for complete rehabilitation before return to full participation. The results of the analytic component of the study alluded to the potential role of competitive level and maturation rate in the profile of the injury- prone gymnast. Specifically, rapid periods of growth and advanced levels of training and competition ap peared to be related to injury proneness. Pursuant to the descriptive and analytic results of the investigation, recommendations for injury prevention and continued research are made.
The sartorial nerve: Its relationship to the medial aspect of the knee
Authors: Arthornthurasook Art , Gaew-lm Kasem
Published: June 2007

When using the medial approach to the knee, as in repair of medial compartment structures, knowledge of the location of the sartorial nerve is important in order to avoid postoperative distress caused by division of this nerve.

We studied the locations of the sartorial nerve in 23 cadavers, with particular reference to the relationship with the pes anserinus and the nerve's distance from the medial femoral epicondyle. The average distance between the sartorial nerve at its emergence and the central point of the medial femoral epicondyle was 34.02 mm, with a range of 20.7 to 49.8 mm on the right lower limb, and 33.27 mm, with a range of 20.0 to 49.2 mm, on the left lower limb.
Allograft ligament transplantation
Authors: Sabiston Paul , Frank CY , Lam Tack , Shrïve Nigel
Published: June 2007

Our purpose in this investigation was to describe and compare several morphological, histological, vascular, and biochemical healing processes of allograft and autograft bone-medial collateral ligament-bone com plexes in a rabbit model. Forty-nine animals had their right medial collateral ligament complex replaced with a frozen allograft while 30 separate control animals each received a fresh autograft. Animals were sacrificed at 3, 6, 12, 24, or 48 weeks after transplantation for comparison of grafted with unoperated contralateral control complexes. Results demonstrate some recov ery of both allografts and autografts over time. Allo grafts generally showed slower recovery than auto grafts with more persistent abnormalities in gross ap pearances, increased cellularity (corresponding to increased DNA content), and decreased collagen con tent. Allografts also showed aggressive remodeling of bone at insertions and they remained hypervascular throughout their substance as compared with contra lateral controls. Autografts went through similar but less chronic increases in cellularity and DNA concentra tion with no changes in collagen content. While both types of grafts showed some signs of "healing" and some recovery of control ligament biology, results are also consistent with allograft encasement, infiltration, and at least partial replacement by host tissue. This was particularly true of insertions. Collectively, these results also demonstrate some differences between allografts and autografts in this extraarticular model. The causes, mechanisms, and longer-term conse quences of these changes, including defining the qual ities of these graft and host tissues, clearly requires further investigation.
Body load in heel-strike running: The effect of a firm heel counter
Authors: Jørgensen Uffe
Published: June 2007

The effect of a firm heel counter in the shoe was studied in 11 athletes during submaximal heel-strike running on a treadmill under standardized conditions. The runners were tested in identical shoes with and without the distal 2 cm of the firm heel counter. Body load was expressed by absolute and relative VO2, surface EMG on the right leg, and g-force registration from an accel erometer below the right tibial tuberosity.

The heel counter caused a 2.4% significant decrease in VO2, a reduction in musculoskeletal transients, and a decrease in the activity of the triceps surae and quadriceps muscles at heel strike.

The changes found are expressions of kinematic adaptations in the body to increased or decreased load and provide functional evidence for the loading factor in the pathophysiology of overuse injuries.
Antegrade curettement, bone grafting and pinning of osteochondritis dissecans in the skeletally mature knee
Authors: Anderson Allen F. , Lipscomb A. Brant , Coulam Craig
Published: June 2007

In the period between 1981 and 1983, we treated 40 patients who had osteochondritis dissecans of the knee. Seventeen patients were skeletally mature and had large lesions (2 to 3 cm in diameter) of the medial femoral condyle that required surgery. Each of these patients, who underwent antegrade curettement, bone grafting, and pinning, had either failed a conservative program or had a loose or separated fragment. The average age at the time of surgery was 17. Followup ranged from 5 to 7 years.

Postoperative evaluation included the criteria of the Hughston et al. rating scale, subjective assessment, clinical examination, and AP, lateral, and tunnel radio graphs. According to the osteochondritis dissecans rating scale described by Hughston et al., there were two excellent, nine good, five fair, no poor results, and one failure. Additional evaluation, not included in the Hughston rating scale, consisted of Cybex II muscle strength testing, strict grading of preoperative and postoperative roentgenograms for degenerative changes, and magnetic resonance imaging.

Roentgenograms demonstrated that 16 of the 17 lesions healed. The average healing time was 8 months. Preoperative degenerative changes occurred fre quently ; postoperatively, there was some progression of these changes in the majority of cases. Magnetic resonance imaging demonstrated that the articular sur face was smooth in 57% of the knees and in 43% there was some degree of irregularity. Although the integrity of the articular cartilage could be documented, mag netic resonance imaging is of questionable value in the postoperative evaluation of this condition, because the status of the articular cartilage could not be correlated with the degree of degenerative changes or results.

The results appear to be worse in those who had more preoperative degenerative changes, a larger le sion, or a loose fragment. This suggests that interven tion before these changes occur may improve results.
Stress fractures in figure skaters
Authors: Pećina Marko , Bojanić Ivan , Dubravčić Sanda
Published: June 2007

In 1987, during two great skating contests—the Univ ersiade in the Tatra Mountains and the Gold Pirouette in Zagreb—a total of 42 world class skaters were asked through a questionnaire if they had ever in their career suffered from a stress fracture. Of the 42 skaters, 9 had stress fractures. Four stress fractures occurred during preseason training (two fibular, one second metatarsal, and two fourth metatarsal stress fractures). Increased mileage was reported by three skaters and the fourth had done too much speed training on hills. Five stress fractures occurred during the season (one tibial and two tarsal navicular stress fractures and two stress fractures of the base of the fifth metatarsal). In all cases, the fracture occurred in the take-off leg. All of the subjects were competitive figure skaters with a daily training period of 3 to 8 hours, six times a week. The time from the onset of symptoms to definite diag nosis ranged from 2 to 10 weeks. Of the nine injured skaters, eight were treated conservatively and one skater with Jones' fracture was treated surgically. All of the skaters were able to resume a preinjury level of activity 3 to 7 months after treatment began. In conclu sion, it may be emphasized that stress fractures in figure skaters are not rare and should, therefore, always be considered as a possibility.
Accelerated rehabilitation after anterior cruciate ligament reconstruction
Authors: Shelbourne K. Donald , Nitz Paul
Published: June 2007

To overcome many of the complications after ACL reconstruction (prolonged knee stiffness, limitation of complete extension, delay in strength recovery, anterior knee pain), yet still maintain knee stability, we devel oped a rehabilitation protocol that emphasizes full knee extension on the first postoperative day and immediate weightbearing according to the patient's tolerance. Of 800 patients who underwent intraarticular ACL patellar tendon-bone graft reconstruction, performed by the same surgeon, the last 450 patients have followed the accelerated rehabilitation schedule as outlined in the protocol. A longer than 2 year followup is recorded for 73 of the patients in the accelerated rehabilitation group. On the 1 st postoperative day, we encouraged these patients to walk with full weightbearing and full knee extension. By the 2nd postoperative week, the patients with a 100° range of motion participated in a guided exercise and strengthening program. By the 4th week, patients were permitted unlimited activities of daily living and were allowed to return to light sports activities as early as the 8th week if the Cybex strength scores of the involved extremity exceeded 70% of the scores of the noninvolved extremity and the patient had completed a sport-specific functional/agility pro gram. The patient database was compiled from fre quent clinical examinations, periodic knee question naires, and objective information, such as range of motion measurements, KT-1000 values, and Cybex strength scores. A series of graft biopsies obtained at various times have revealed no adverse histologic re action. The evidence indicates that in this population, the accelerated rehabilitation program has been more effective than our initial program in reducing limitations of motion (particularly knee extension) and loss of strength while maintaining stability and preventing an terior knee pain.
The efficacy of a prophylactic knee brace to reduce knee injuries in football
Authors: Sitler Michael , Ryan Col Jack , Hopkinson Ltc William , Wheeler Ltc James , Santomier James , Kolb Ltc Rickey , Polley Capt David
Published: June 2007

The purpose of this prospective, randomized study was to determine the efficacy of a prophylactic knee brace to reduce the frequency and severity of acute knee injuries in football in an athletic environment in which the athletic shoe, playing surface, athlete-exposure, knee injury history, and brace assignment were either statistically or experimentally controlled. The partici pants in the study were 1396 cadets at the United States Military Academy, West Point, New York, who experienced a total of 21,570 athlete-exposures in the 1986 and 1987 fall intramural tackle football seasons. The use of prophylactic knee braces significantly re duced the frequency of knee injuries, both in the total number of subjects injured and in the total number of medial collateral ligament injuries incurred. However, the reduction in the frequency of knee injuries (total and medial collateral ligament) was dependent on player position. Defensive players who wore prophylactic knee braces had statistically fewer knee injuries than players who served as controls. This was not true of offensive players who served as controls; they had statistically no difference in the number of knee injuries from players who wore prophylactic knee braces. The severity of medial collateral ligament and anterior cruciate ligament knee injuries was not significantly reduced with the use of prophylactic knee braces.
Pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser ablation of fibrocartilage and articular cartilage
Authors: Trauner Kenneth , Nishioka Norman , Patel Dinesh
Published: June 2007

A new, near-infrared, pulsed holmium laser (wave length, 2.1 μm; pulse duration, 400 μs) was used to ablate bovine articular cartilage and meniscal fibrocar tilage. Microscopic examination revealed zones of ther mal damage extending 550 μm from ablation sites. Ablation rates were measured with a mass loss tech nique. Above threshold, mass removal rates were pro portional to laser radiant exposure. Threshold radiant exposure for ablation was 50 J/cm2 for articular carti lage and 11 J/cm2 for meniscal fibrocartilage. Because the holmium laser can precisely and rapidly resect cartilaginous tissues with only moderate necrosis, func tion in a saline environment in direct contact with tissue, and be transmitted through conventional optical fibers, it has the potential to become a useful tool for the precise arthroscopic removal of intraarticular tissue.
Subject variability of shoulder abduction strength testing
Authors: Magnusson S. Peter , Gleim Gilbert W. , Nicholas James A.
Published: June 2007

To quantify normal biological variability of shoulder abduction strength testing with an isokinetic and a hand-held dynamometer, we tested nine healthy sub jects over a clinically relevant period. One side was tested with a Cybex at 60 deg/sec and the other with a hand-held dynamometer. Six maximal trials, following warmup, were conducted on each of 5 days, separated by 1 to 2 weeks. Intraday correlations of individual trials ranged from 0.82 to 0.995 for hand-held dynamometer, and 0.88 to 0.996 for Cybex. Interday correlations ranged from 0.94 to 0.98 for hand-held dynamometer, and 0.88 to 0.97 for Cybex. The best values to use for Cybex interday variability were the average of the first three repetitions, and yielded standard errors of 8.6% to 19.2% of the sample mean. The average of the last three repetitions were the best for hand-held dynamom eters, and yielded standard errors of 5.5% to 10.8%. There was a significant decline (P < 0.05) in strength of the mean of the last three versus the mean of the first three daily repetitions on Day 1 and 4 for hand- held dynamometers, and a trend toward this on the other days, that was not seen with Cybex. Regression of average Day 1 values for Cybex and hand-held dynamometer yielded r = 0.86 (P < 0.01) with a slope of 1.07 indicating good agreement between modalities. In conclusion, intraday/interday correlations were high for Cybex and hand-held dynamometer. Interday vari ability was minimized by using the mean score of the first three and last three repetitions for Cybex and hand- held dynamometer, respectively. Changes in Cybex and hand-held dynamometer strength of less than 19% and 11 %, respectively, are within the area of "measurement error" and should therefore not be considered clinically significant.
Lateral release of the patella: Indications and contraindications
Authors: Kolowich Patricia A. , Paulos Lonnie E. , Rosenberg Thomas D. , Farnsworth Steve
Published: June 2007

Charts were reviewed on patients at the Salt Lake Knee and Sports Medicine Clinic who had had a lateral release of the patella. Patients were divided into two groups. Group I contained patients who were entirely satisfied with the procedure, and Group II included patients who were complete failures (defined as a need for further surgical procedures). In Group I, 74 patients were included in the subjective followup. Forty of the 74 patients also had an objective followup, including roentgenograms and a physical examination. Group II contained 43 patients. Results indicated that the most predictable criterion for success was a negative passive patellar tilt. Secondary criteria included a medial and lateral patellar glide of two quadrants or less and a normal tubercle-sulcus angle at 90° of flexion. Patients had less predictable results after an isolated lateral release with a positive (greater than 5°) passive patellar tilt and a three quadrant or greater medial and lateral patellar glide or an abnormal tubercle-sulcus angle at 90° of flexion.
Living with artificial grass: A knowledge update
Authors: Levy I. Martin , Skovron Mary Louise , Agel Julie
Published: June 2007

Part I of this two part study reviews the development and characteristics of artificial grass, and the influence of this surface on the American football player.

Artificial grass was initially developed to provide city children with increased play space and thus enable them to maintain a fitness level equal to their peers in more rural locales. Today, artificial grass fields allow for increased use when field availability is limited, or for a grass substitute where grass will not grow. However, epidemiologic studies suggest that there is an in creased risk of lower extremity injury to the football athlete playing on an artificial grass field. By reviewing available studies, a knowledge base can be formed that can serve to direct future investigations concerning the influence of artificial grass surfaces and injury and, ultimately, how that influence can be affected.
Sports medical experiences from the International Flower Marathon for disabled wheelers
Authors: Hoeberigs J.H. , Debets-Eggen H.B.L. , Debets P.M.L.
Published: June 2007

Little is known about sports medical problems in long distance wheelchair athletes. Using a continuous mon itoring system, we studied participants of a yearly wheelchair event lasting 1 week (International Flower Marathon). The aims were 1) to evaluate the medical problems in 40 athletes who took part in the 1986 edition and 2) to explore whether problems in previous editions (1984 and 1985) played a role in the decision to take part in 1986.

The results showed that 19 athletes experienced 20 medical problems, many of which were caused by spills or were related to climatologic conditions. Problems were relatively more frequent in paraplegics and polio- disabled athletes (N = 22) than in the remaining com petitors (N = 18). Statistical analysis showed that this difference was significant (P < 0.01). Complaints in previous editions of the same event did not play a role in the athletes' decision to participate in the 1986 edition. This study suggests that the number and seri ousness of injuries and other medical problems in dis abled wheelers is related to environmental conditions as well as to the nature of disabilities involved. The study also shows, without doubt, that long distance events for wheelers need the support of adequate medical escorts.
Anteromedial tibial tubercle transfer without bone graft
Authors: Fulkerson John P. , Becker Gerald J. , Meaney John A. , Miranda Michael , Folcik Marilyn A.
Published: June 2007

We followed 30 patients for more than 2 years after anteromedial tibial tubercle transfer for persistent pa tellofemoral pain associated with patellar articular de generation. Twelve of these patients were followed more than 5 years. We report 93% good and excellent results subjectively and 89% good and excellent results objectively. The quality of improvement was sustained in all 12 of the patients who were evaluated again after more than 5 years from surgery. When examined sep arately, 75% of those patients with advanced patellar arthrosis achieved a good result; none of these patients achieved an excellent result. Postoperative continuous passive motion has markedly reduced the incidence of stiffness. Serious complications such as compartment syndrome, infection, and skin slough were avoided completely in 51 consecutive cases. Patellofemoral contact pressure studies in five cadaver knees have shown that anteromedial tibial tubercle transfer can provide substantial reduction of patellofemoral contact stress while helping to balance medial and lateral facet pressures. This surgical procedure is mechanically and clinically successful for alleviating intractable pain re lated to patellar malalignment and articular degenera tion. This procedure enables the majority of appropri ately selected patients with malalignment and patellar articular degeneration to resume increased levels of activity with substantially diminished pain.