bluuebunny/crossref_metadata_2025 huggingface dataset:
Arthroscopically Assisted Semitendinosus and Gracilis Tendon Graft in Reconstruction for Acute Anterior Cruciate Ligament Injuries in Athletes
Authors: Aglietti Paolo , Buzzi Roberto , Menchetti Pier Paolo M. , Giron Francesco
Published: June 2007

We evaluated 69 arthroscopically assisted anterior cru ciate ligament reconstructions for acute tears at an average followup of 60 months. We used a distally based single semitendinosus and gracilis tendon graft passed over the top and fixed to the femur. Combined medial collateral ligament lesions were seen in 30 knees, and they were repaired when found in the distal third (18 knees). The patients were instructed to re cover motion preoperatively, and an early range of motion program was used postoperatively. At followup, symptoms of giving way were seen in five knees (7%). Graft failure was seen in seven knees (10%); failure was defined as a positive pivot shift (clunk or gross) or a side-to-side difference in anterior tibial displacement greater than 5 mm, as measured with a KT-1000 ar thrometer. Permanent extension loss (3° to 5°) was found in two knees (3%). Patellofemoral crepitation was seen in eight knees (12%), but the condition was symptomatic in only one knee. Forty-six patients (67%) were active in pivoting sports before surgery and 37 (54%) remained active in these sports at followup. We concluded that this operation is simple, effective, and has a low complication rate. Further studies are nec essary to elucidate if a stronger graft (e.g., a patellar tendon) would decrease the rate of graft failure without increasing complications.
Ankle Flexibility and Injury Patterns in Dancers
Authors: Wiesler Ethan R. , Hunter D. Monte , Martin David F. , Curl Walton W. , Hoen Helena
Published: June 2007

Lower-extremity injuries are common among dancers and cause significant absences from rehearsals and performances. For this study of lower-extremity injuries in 101 ballet and 47 modern dance students, injuries requiring medical attention sustained over 1 academic year were associated with the following data obtained at the beginning of the school year: ankle flexibility, sex, dance discipline, previous injury, body mass in dex, and years of training. Eighty-three of the 148 students (age range, 12 to 28 years) reported prior lower-limb injuries, the most common being ankle sprains (28% of all dancers). Previous leg injuries cor related significantly with lower dorsiflexion meas urements and with more new injuries. Female students had greater ankle and first metatarsophalangeal flexi bility. Modern dancers had greater ankle inversion. Ninety-four students sustained 177 injuries during the study, including 75 sprains or strains and 71 cases of tendinitis. Thirty-nine percent ( N = 69) were ankle injuries; 18% ( N = 33) were knee injuries; 23% ( N = 40) were foot injuries; and 20% (N = 35) were either hip or thigh injuries. Sixty-seven percent (N = 78) of the injured students were ballet dancers. Age, years of training, body mass index, sex, and ankle range of motion measurement had no predictive value for injury; previous injury and dance discipline both correlated with increased risk of injury.
Plyometric Training in Female Athletes
Authors: Hewett Timothy E. , Stroupe Amanda L. , Nance Thomas A. , Noyes Frank R.
Published: June 2007

The purpose of this study was to test the effect of a jump-training program on landing mechanics and lower extremity strength in female athletes involved in jump ing sports. These parameters were compared before and after training with those of male athletes. The program was designed to decrease landing forces by teaching neuromuscular control of the lower limb dur ing landing and to increase vertical jump height. After training, peak landing forces from a volleyball block jump decreased 22%, and knee adduction and abduc tion moments (medially and laterally directed torques) decreased approximately 50%. Multiple regression analysis revealed that these moments were significant predictors of peak landing forces. Female athletes demonstrated lower landing forces than male athletes and lower adduction and abduction moments after training. External knee extension moments (hamstring muscle-dominant) of male athletes were threefold higher than those of female athletes. Hamstring-to- quadriceps muscle peak torque ratios increased 26% on the nondominant side and 13% on the dominant side, correcting side-to-side imbalances. Hamstring muscle power increased 44% with training on the dom inant side and 21 % on the nondominant. Peak torque ratios of male athletes were significantly greater than those of untrained female athletes, but similar to those of trained females. Mean vertical jump height in creased approximately 10%. This training may have a significant effect on knee stabilization and prevention of serious knee injury among female athletes.
Risk Factors for Stress Fractures in Track and Field Athletes
Authors: Bennell Kim L. , Malcolm Susan A. , Thomas Shane A. , Reid Sally J. , Brukner Peter D. , Ebeling Peter R. , Wark John D.
Published: June 2007

The aim of this 12-month prospective study was to investigate risk factors for stress fractures in a cohort of 53 female and 58 male track and field athletes, aged 17 to 26 years. Total bone mineral content, regional bone density, and soft tissue composition were meas ured using dual-energy x-ray absorptiometry and an thropometric techniques. Menstrual characteristics, current dietary intake, and training were assessed us ing questionnaires. A clinical biomechanical assess ment was performed by a physical therapist. The inci dence of stress fractures during the study was 21.1%, with most injuries located in the tibia. Of the risk factors evaluated, none was able to predict the occurrence of stress fractures in men. However, in female athletes, significant risk factors included lower bone density, a history of menstrual disturbance, less lean mass in the lower limb, a discrepancy in leg length, and a lower fat diet. Multiple logistic regression revealed that age of menarche and calf girth were the best independent predictors of stress fractures in women. This bivariate model correctly assigned 80% of the female athletes into their respective stress fracture or nonstress frac ture groups. These results suggest that it may be pos sible to identify female athletes most at risk for this overuse bone injury.
Assessment of Posterior Cruciate Ligament Graft Performance Using Robotic Technology
Authors: Stone Jeffrey D. , Carlin Gregory J. , Ishibashi Yasuyuki , Harner Christopher D. , Woo Savio L.-Y.
Published: June 2007

We used the information on in situ forces provided by robotics to compare two methods of posterior cruciate ligament graft fixation. Twenty porcine knees were studied using robotic technology to determine and re peat intact, deficient, and reconstructed knee motion under 110 N of posterior tibial loading at 30°, 60°, and 90° of knee flexion. Reconstruction was performed using a bone-patellar tendon-bone graft with the distal end of the graft placed in the posterolateral aspect of the posterior cruciate ligament tibial insertion. Speci mens were separated into two groups based on the femoral fixation site: the proximal or anterior aspect of the femoral insertion. Repetition of knee motion al lowed measurement of the force in the intact posterior cruciate ligament and graft using the principle of su perposition. The forces in the graft and the intact liga ment provided additional information to evaluate graft performance. Force in the intact posterior cruciate lig ament was significantly greater at 90° than at 30° and 60° of knee flexion. The forces in both graft types were significantly lower than those of the posterior cruciate ligament, but the force in the anteriorly placed graft was significantly greater at 90° than at 30° and 60° of knee flexion, similar to the intact posterior cruciate ligament. Thus, the anteriorly placed graft had a more physiologic increase in tension with knee flexion, when the joint provided less restraint.
Preventing Anterior Knee Pain After Anterior Cruciate Ligament Reconstruction
Authors: Shelbourne K. Donald , Trumper Rocci V.
Published: June 2007

We studied a group of 602 patients who had anterior cruciate ligament reconstructions between 1987 and 1992. An autogenous patellar tendon graft was used, regardless of preexisting patellofemoral pain or chon dromalacia. The surgeon and rehabilitation protocol were the same for all patients, with emphasis on ob taining full knee hyperextension postoperatively. All patients were evaluated by a questionnaire designed to determine the incidence and severity of anterior knee pain as it relates to sporting or daily living activ ities, prolonged sitting, stair climbing, and kneeling. Range of motion for the study group was recorded during physical examination. We compared the find ings with those from a control group of 122 patients who had no previous knee injury. The study group reported a mean score of 89.5 ± 12.5, compared with 90.2 ± 12.3 in the control group. Both the operative and control groups reported little or no symptoms dur ing sporting activities (94% and 92%, respectively). No differences were noted with respect to the other activ ities surveyed. These results demonstrate that anterior knee pain after anterior cruciate ligament reconstruc tion is not an inherent complication associated with patellar tendon harvesting. We suggest that the in creased incidence of anterior knee pain with an autog enous patellar tendon graft can be prevented by ob taining full knee hyperextension postoperatively. This goal can be achieved through preoperative rehabilita tion and a postoperative protocol emphasizing early restoration of full knee hyperextension.
Direct Injury to the Axillary Nerve in Athletes Playing Contact Sports
Authors: Perlmutter Gary S. , Leffert Robert D. , Zarins Bertram
Published: June 2007

We performed long-term followup (31 to 276 months) of 11 contact athletes who had sustained isolated in juries to their axillary nerves during athletic competi tion. There were no known shoulder dislocations. Elec tromyographs were taken of 10 patients, and all patients had confirmation of clinically defined injuries that were confined to their axillary nerves. Nine injuries were sustained while tackling opposing players in foot ball ; two were sustained in hockey collisions. In seven athletes, the mechanism of injury was a direct blow to the anterior lateral deltoid muscle. In four athletes, there were simultaneous contralateral neck flexion and ipsilateral shoulder depression. At followup, all patients had residual deficits of axillary sensory and motor nerve function. There had been no deltoid muscle im provement in three patients, moderate improvement in two patients, and major improvement in six patients. However, shoulder function remained excellent, with all athletes maintaining full range of motion and good- to-excellent motor strength. Axillary nerve exploration and neurolysis in four patients did not significantly affect the outcomes. Although no patient had full re covery of axillary nerve function, 10 of 11 athletes returned to their preinjury levels of sports activities, including professional athletics.
End-to-End Operative Repair of Achilles Tendon Rupture
Authors: Soldatis Jeffery J. , Goodfellow Donald B. , Wilber John H.
Published: June 2007

We present the long-term results of operative repair in 23 consecutive patients with Achilles tendon ruptures, treated between 1984 and 1991, to evaluate our treat ment method and determine the clinical causes of rupture. Fifty-four percent of ruptures occurred in peo ple in their 30s; 90% occurred during participation in acceleration-deceleration sports. All but three patients were treated within 1 week of injury with open, opera tive, end-to-end repair of the Achilles tendon. The re maining three patients were treated more than 3 weeks after injury. All patients followed a standard postoper ative regimen. Followup averaged 3.6 years (range, 1 to 7.5). Seventeen patients were available for Cybex analysis, and the remaining patients were interviewed personally or by telephone. Subjectively, patients were very satisfied with the results of treatment. Objectively. physical examination and Cybex testing to measure strength and endurance revealed results somewhat better than those previously reported with operative repair. No patient experienced a rerupture, although one attenuated repair was noted 9 months postopera tively. Only two minor wound problems were recorded. Long-term results revealed near-normal function when comparing the injured side with the uninjured side. Ninety-two percent of patients returned fully to their preinjury levels of activity.
The Role of the Knee Brace in the Prevention of Anterior Knee Pain Syndrome
Authors: BenGal Shlomo , Lowe Joseph , Mann Gideon , Finsterbush Alexander , Matan Yoav
Published: June 2007

Our prospective study evaluates the use of a knee brace with a silicon patellar support ring as a method of preventing anterior knee pain from developing in young persons undergoing strenuous physical exercise. We studied 60 young athletes, who qualified for a strenu ous physical training course and who had not suffered from anterior knee pain previously. Twenty-seven sub jects were in the brace group and 33 were in the nonbrace control group. The incidence of anterior knee pain syndrome increased with the intensity of exertion as the study progressed; i.e., subjects ran 6 km in the 1 st week, gradually increasing each week up to 42 km/week at the 8th week. Yet, there was a significant reduction in the incidence of the syndrome at the end of the study in male athletes who had applied the braces before exercise sessions and in the brace group as a whole, compared with the control group. Prophylactic use of the brace, as described, did not reduce the ability of the athletes who wore braces to improve their physical fitness parameters in response to exercise. These data indicate that the use of a brace may be an effective way to prevent the development of anterior knee pain syndromes in persons participating in strenuous and intensive physical exercise.
Evaluation of Pain After Arthroscopically Assisted Anterior Cruciate Ligament Reconstruction
Authors: Brown Douglas W. , Curry Craig M. , Ruterbories Linda M. , Avery F. Lincoln , Anson Philip S.
Published: June 2007

Pain after arthroscopically assisted anterior cruciate reconstruction was examined during the first 5 postop erative days to evaluate its intensity and duration. One hundred consecutive patients who underwent arthro scopically assisted anterior cruciate ligament recon struction using a bone-patellar tendon-bone autograft were examined. During surgery, ketorolac (60 mg) was given intravenously and 0.25% bupivicaine (1 ml/kg total) was injected into the joint space and the graft donor site. After surgery, all patients received sched uled doses of oral acetaminophen (650 mg) and ke torolac (10 mg) four times a day, and they were al lowed to take oral oxycodone (5 to 10 mg) every 2 hours as needed. Pain scores at rest and with activity reached a maximum on the 2nd postoperative morn ing. Oxycodone consumption also peaked on the 2nd postoperative day. Eighty-nine (89%) patients reported overall pain as mild or moderate, and 95 patients (95%) reported either excellent or good overall relief of pain. The 5-day cumulative mean of visual analog scale pain scores for attempting straight leg raises was significantly higher for patients unable to successfully perform that activity than for patients who were able to perform it. The association between elevated pain scores and diminished ability to perform straight leg raises suggests that pain may inhibit function and therefore early rehabilitation.
Evidence of Reinnervation of Free Patellar Tendon Autograft Used for Anterior Cruciate Ligament Reconstruction
Authors: Barrack Robert L. , Lund Peter J. , Munn Barry G. , Wink Carole , Happel Leo
Published: June 2007

We studied six adult male dogs to determine whether free patellar tendon grafts show evidence of reinner vation when used for anterior cruciate ligament recon struction. Histologic return of neural elements and re turn of a somatosensory-evoked potential defined evidence of reinnervation. Before removal, the native anterior cruciate ligament was electrically stimulated with a bipolar electrode and a somatosensory-evoked potential was recorded from a scalp electrode. The ligament was excised and reconstructed using an au togenous patellar tendon graft. Somatosensory- evoked potential was attempted immediately after reconstruction. Histology for nerve endings was per formed on the native ligaments. Each animal under went repeat arthrotomy 6 months later. The grafts were isolated and somatosensory-evoked potentials were attempted. An evoked potential was seen in all six dogs before reconstruction. No graft demonstrated a somatosensory-evoked potential acutely; however, 6 months postoperatively, the somatosensory-evoked potential returned in two cases. Histology of native ligaments showed that 25% of the 100 sections eval uated contained neural elements. Of the receptors present, 89% were mechanoreceptors and 11 % were free nerve endings. Histologic examination of the graft tissue 6 months postoperatively revealed that all six grafts also contained neural elements. Mechanorecep tors and free nerve endings were present in approxi mately equal numbers in the grafts. The results of histology and somatosensory-evoked potential demon strate that in at least some cases, free patellar tendon grafts show evidence of reinnervation when used for anterior cruciate ligament reconstruction.
Patellar Dislocation
Authors: Mäenpää Heikki , Lehto Matti U. K.
Published: June 2007

One hundred patients were treated nonoperatively for primary acute patellar dislocations, either by plaster cast (N = 60), by posterior splint (N = 17), or by patellar bandage or brace (N = 23). Follow-up exam inations were performed at an average of 13 years later (range, 6 to 26 years). Overall, there were 0.17 redislocations per follow-up year; the redislocation fre quencies per follow-up year for each patient group were 0.29, patellar bandages or braces; 0.12, plaster cast; and 0.08, posterior splint. In addition, there were fewer recurrences and subsequent problems (patel lofemoral pain or subluxations) in the group treated with posterior splints compared with the two other treatment groups. The most marked restrictions of knee joint movements were seen in the patients treated with plaster casts. Subjective assessment of treatment, however, did not differ significantly between the groups. Patients were also evaluated in relation to the treatment of redislocations and management of subsequent problems (i.e., patellofemoral pain or sub luxations). Patients who were treated operatively for their redislocations exhibited better outcomes than pa tients treated nonoperatively. In the patients who had subsequent problems, the operation did not relieve the symptoms.
Cervical Spine Alignment in the Immobilized Football Player
Authors: Swenson Todd M. , Lauerman William C. , Blanc Robert O. , Donaldson William F. , Fu Freddie H.
Published: June 2007

We investigated the effect of football helmet removal on the sagittal alignment of the cervical spine. A quan titative radiographic assessment of relative cervical spine position in subjects immobilized to a standard backboard wearing shoulder pads either with or with out a helmet was performed. Comparison was made to a control situation with subjects on a backboard wear ing no equipment. Ten subjects were studied using lateral computed tomographic scout films; each subject served as his own control. Radiographs were meas ured for overall sagittal cervical alignment and the amount of lordosis or kyphosis present within specific segments of the cervical spine. Mean values for each of the three defined situations (no equipment, shoulder pads and helmet, shoulder pads alone after helmet removal) were calculated and subjected to statistical analysis. No statistically significant difference in cervi cal sagittal alignment was noted when either no equip ment or both shoulder pads and helmet were worn. In contrast, a statistically significant increase in cervical lordosis (extension) was found when comparing the control situation to that when only shoulder pads were worn after the helmet had been removed. The majority of this increase occurred in the subaxial spine. There fore, the authors recommend that football players with a potential cervical spine injury be immobilized for transport with both their helmet and shoulder pads left in place, thereby maintaining the neck in a position most closely approximating "normal."
Intensive Dance Practice
Authors: Pigeon Patricia , Oliver I. , Charlet J.P. , Rochiccioli P.
Published: June 2007

To determine the effect of intensive sports training on growth and puberty, we studied a group of 97 young female dancers longitudinally for 5 years. We studied the changes in their heights, weights, and pubertal developments and compared these findings with those of a control group. We found that 15 (16%) dancers who started dance training had noticeably decreased growth velocity during the prepuberty stage after the beginning of ballet practice compared with the control group. This group had the same average training time compared with the other dancers, but these dancers were the slimmest and had the most inadequate nutri tional intake. Puberty in dancers was delayed com pared with the controls. We found that moderately intensive dance practice can lead to eating disorders and weight control early in childhood, with conse quences that are poorly known. Weight and height statistics of children who practice individual sports in volving body aesthetics must be monitored to detect early anomalies.
Impact Loading of the Lumbar Spine During Football Blocking
Authors: Gatt Charles J. , Hosea Timothy M. , Palumbo Robert C. , Zawadsky Joseph P.
Published: June 2007

The purpose of our study was to determine the impact force to the lumbar spine when football players hit a blocking sled. We quantified the loads at the L4-5 motion segment throughout the blocking sequence. Five Division I-A college football linemen were subjects for our study. Kinematic data were obtained while the subjects hit a blocking sled instrumented with a force plate. Three plane forces were then calculated from these data. The average impact force measured at the blocking sled was 3013 ± 598 N. The average peak compression force at the L4-5 motion segment was 8679 ± 1965 N. The average peak anteroposterior shear force was 3304 ± 1116 N, and the average peak lateral shear force was 1709 ± 411 N. The magnitude of the loads on the L4-5 motion segment during foot ball blocking exceed those determined during fatigue studies to cause pathologic changes in both the lumbar disk and the pars interarticularis. These data suggest that the mechanics of repetitive blocking may be re sponsible for the increased incidence of lumbar spine injury incurred by football linemen.
Biomechanics of Ankle Ligament Reconstruction
Authors: Bahr Roald , Pena Fernando , Shine Joe , Lew William D. , Tyrdal Stein , Engebretsen Lars
Published: June 2007

We wanted to use biomechanical testing in a cadaveric model to compare the Broström repair, the Watson- Jones reconstruction, and a new anatomic reconstruc tion method. Eight specimens were held in a specially designed testing apparatus in which the ankle position (dorsiflexion-plantar flexion and supination-pronation) could be varied in a controlled manner. Testing was done with intact ligaments and was repeated after sectioning of the anterior talofibular ligament and the calcaneofibular ligament and after a Broström repair, a Watson-Jones reconstruction, and a new anatomic re construction were performed. An anterior drawer test was performed using an anterior translating force of 10 to 50 N, and a talar tilt test was performed using a supination torque of 1.1 to 3.4 N-m. The forces in the anterior talofibular ligament and calcaneofibular liga ment were measured with buckle transducers, and tibiotalar motion and total ankle joint motion were meas ured with an instrumented spatial linkage. The in crease in ankle joint laxity observed after sectioning of both the anterior talofibular and calcaneofibular liga ments was significantly reduced by the three recon structive techniques, although not always to the level of the intact ankle. Joint motion was restricted after the Watson-Jones procedure compared with that in the intact ankle. Unlike the Watson-Jones procedure, the ligament or graft force patterns observed during load ing after the Broström repair and the new anatomic technique resembled those observed in the intact ankle.
Anterior Cruciate Ligament Graft Fixation
Authors: Rowden Neville J. , Sher Doron , Rogers Greg J. , Schindhelm Klaus
Published: June 2007

The initial biomechanical properties of semitendinosus and patellar tendon autografts and their fixation strengths were investigated. Twenty fresh cadaveric knees from donors under 42 years of age were used in the study. After removing all soft tissues other than the anterior cruciate ligament, we determined the ultimate tensile strength (2195 ± 427 N) and stiffness (306 ± 80 N/mm) of the anterior cruciate ligament in nine knees. In six knees, anterior cruciate ligaments were reconstructed using an autologous patellar tendon graft with proximal and distal interference fit screws; this resulted in an ultimate tensile strength of 416 ± 66 N. Five knees were reconstructed with quadruple- stranded (double-looped) semitendinosus tendons fixed proximally by a titanium button and braided tape and distally by tibial post screw. This resulted in an ultimate tensile strength of 612 ± 73 N, which was significantly higher than the strength in the patellar tendon group. Graft stiffness did not differ between the groups and was 47 ± 19 N/mm (N = 11). This study demonstrates that the reconstructed knees had only 20% to 30% of the ultimate tensile strength of the normal anterior cruciate ligament. In summary, the semitendinosus reconstruction using a button for prox imal fixation is, at the time of surgery, approximately 50% stronger than patellar tendon reconstructions with similar stiffness.
Shoulder Motion and Laxity in the Professional Baseball Player
Authors: Bigliani Louis U. , Codd Timothy P. , Connor Patrick M. , Levine William N. , Littlefield Mark A. , Hershon Stuart J.
Published: June 2007

We studied 148 professional baseball players with no history of shoulder problems to assess range of motion and laxity of their dominant and nondominant shoul ders. There were 72 pitchers and 76 position players. Average external rotation with the arm in 90° of abduc tion was statistically greater and average internal rota tion was statistically less in the dominant shoulders than in the nondominant shoulders, both in pitchers and position players. There was no statistical differ ence in forward elevation or external rotation with the arm at the side of the body in either group. Both dom inant and nondominant shoulders of pitchers had greater average range of motion in forward elevation and external rotation (both at the side and at 90° of abduction) and less average internal rotation than those of position players. Regarding laxity testing, 61 % of dominant shoulders in pitchers had a sulcus sign, as compared with 47% in position players. Also, this de gree of inferior laxity was significantly greater in pitch ers than in position players. Differences in range of motion and laxity exist in the throwing shoulder of athletes involved in overhead throwing motions and should be considered in rehabilitation protocols and surgical repair.
Diagnosis of Complete and Partial Posterior Cruciate Ligament Ruptures
Authors: Hewett Timothy E. , Noyes Frank R. , Lee Michael D.
Published: June 2007

Stress radiography was performed on 21 patients with unilateral posterior cruciate ligament tears: 10 com plete and 11 partial. An 89-N posterior load was ap plied to the proximal tibia and a lateral radiograph was taken of each knee in 70° of flexion. The relative amount of sagittal translation (involved minus nonin volved) was determined at both the medial and lateral tibial plateaus from the radiographic films. Arthrometric (KT-1000 arthrometer) and posterior drawer tests were also performed. The mean relative posterior translation averaged 12.2 ± 3.7 mm for knees with complete tears. Arthrometer testing of the same knees showed 7.6 ± 2.5 mm of increased translation, and posterior drawer testing showed 9.2 ± 3.3 mm of increased dropback. Stress radiographic results were statistically similar to the electrogoniometric measurements in ca daveric knees. In knees with a partially torn posterior cruciate ligament, mean relative translation measured on stress radiographs was 5.6 ± 1.5 mm, which was significantly different from that for knees with complete ruptures. The arthrometer and posterior drawer test data were not significantly different for knees with com plete and partial tears. Stress radiography is superior to both the arthrometer and clinical posterior drawer testing for determining posterior cruciate ligament sta tus. Eight millimeters or more of increased posterior translation on stress radiographs is indicative of com plete rupture.
Results of Isolated Patellar Debridement for Patellofemoral Pain in Patients with Normal Patellar Alignment
Authors: Federico Dale J. , Reider Bruce
Published: June 2007

We reviewed the records of 36 patients who underwent arthroscopic patellar debridement for patellofemoral pain. All patients had isolated chondromalacia patellae noted during arthroscopic examination. No patient had a history of patellar instability or physical or radio graphic signs of patellar malalignment. The chondro malacia patellae was classified as traumatic or atrau matic in origin. All patients had failed results after a minimum of 4 months of physical therapy before sur gery, and all patients had grade 2 or worse chondro malacia patellae at the time of debridement. At the time of followup, patients were evaluated by questionnaire, Fulkerson-Shea Patellofemoral Joint Evaluation score, independent physical examination, and radiographs. Patients were also asked to subjectively score their knees preoperatively, at the time of maximal improve ment postoperatively, and at the time of followup for comparison. Preoperative examinations and radio graphs were compared with examinations at the time of followup. The most significant finding was the im provement in the overall joint evaluation score. The score for the entire group improved from a mean of 51.9 preoperatively to 78.8 at the time of maximal improvement and 75.3 at the time of followup. All but four patients subjectively thought that surgery had a beneficial effect. There were no observed changes in the preoperative and postoperative radiographs. Pa tients with traumatic chondromalacia patellae had 57.9% good or excellent results with surgery, and the patients with atraumatic cases had 41.1 % good or excellent results with surgery, indicating that many patients who were improved by the surgery still had functional limitations.
High School Sports Injuries
Authors: Beachy Glenn , Akau Cedric K. , Martinson Matthew , Olderr Timothy F.
Published: June 2007

We conducted an 8-year, prospective, longitudinal study of athletic injuries occurring to students in grades 7 to 12 at a private school in Honolulu. All injuries were evaluated by the same personnel. A total of 14,318 athletes participated in 32 sports; multisport athletes were counted once per sport. Every time an athlete sought medical help it was considered a reportable injury. The five injury classifications were 1) minor, no time lost; 2) mild, 1 to 7 days lost; 3) moderate, 8 to 21 days lost; 4) severe, 22 or more days lost; and 5) catastrophic, permanent disability or death. Athletes reported 11,184 injuries, with 3965 (35%) day-lost in juries (a minimum of 1 day lost from activity). Football resulted in the highest injury rate for male athletes. Soccer resulted in the highest injury rate for female athletes. With the football and wrestling data removed, there was no significant difference between the rate of injury for boys (0.58 injuries per athlete and 0.21 day- lost injuries per athlete) and girls (0.64 injuries per athlete and 0.21 day-lost injuries per athlete).
Symmetry of the Femoral Notch Width Index
Authors: Teitz Carol C. , Lind Bonnie K. , Sacks Benjamin M.
Published: June 2007

A small femoral notch width index has been reported as a predictive factor for anterior cruciate ligament injury and implicated in the higher incidence of anterior cruciate ligament injuries in female athletes. Notch plasty has been recommended for the unaffected knees of patients who have torn one anterior cruciate ligament and whose notch width index falls one stan dard deviation below "normal." However, the symmetry of the notch width index has not been specifically stud ied. We compared the notch width index in both knees of 40 male and 40 female patients. Half of the patients in each group had anterior cruciate ligament injuries, all from a noncontact mechanism. We found that the notch width indexes of the right and left knees of the same patient are essentially symmetrical, regardless of sex or anterior cruciate ligament status. Although the female patients tended to have smaller notch width indexes than the male patients, the difference was not statistically significant. Moreover, the ranges of notch width indexes in male and female patients overlapped considerably. Finally, there was no difference in notch width index between patients with and without anterior cruciate ligament tears. These findings suggest that the notch width index alone is not the critical etiologic factor in the patient with a unilateral anterior cruciate ligament tear. Furthermore, the increased incidence of anterior cruciate ligament tears in female patients com pared with male patients in the same sports cannot be attributed to notch width index alone.
The Effect of Strength and Flexibility Training on Skeletal Muscle Electromyographic Activity, Stiffness, and Viscoelastic Stress Relaxation Response
Authors: Klinge Klaus , Magnusson S. Peter , Simonsen Erik B. , Aagaard Per , Klausen Klaus , Kjaer Michael
Published: June 2007

The present study examined whether isometric strength training alone or isometric strength training combined with flexibility training of the hamstring mus cles altered the viscoelastic response during stretch. Twelve male subjects performed isometric training (strength) on one side and isometric and flexibility training (strength and flexibility) on the other side for 13 weeks; 10 other subjects served as controls. Passive torque offered by the hamstring muscle group was measure during passive knee extension using a dyna mometer. The knee was passively extended to a pre determined final position at 0.0875 rad/sec (dynamic phase), where it remained stationary for 90 seconds (static phase). The slope of the line (stiffness) and the area under the curve (energy) in the dynamic phase, and the decline in passive torque (viscoelastic stress relaxation) in the static phase were analyzed. Isometric strength was determined with a dynamometer. A strength test and a stretch maneuver were adminis tered before and after the training period. All variables were unchanged in the control group. Isometric strength increased similarly on both training sides by 43%. The stretch maneuver showed that energy, stiff ness, and passive torque increased on both training sides while low-level electromyographic recordings re mained constant. Furthermore, the viscoelastic stress relaxation response (31 % to 33%) was unaffected by the training. The addition of flexibility exercises had no significant effect on these strength training responses. These data suggest that an increase in isometric strength is accompanied by changes in the material properties of the muscle that are unaffected by flexibil ity exercises.
Distal Radial Growth Plate Injury and Positive Ulnar Variance in Nonelite Gymnasts
Authors: DiFiori John P. , Puffer James C. , Mandelbaum Bert R. , Dorey Frederick
Published: June 2007

To assess the prevalence of stress injury to the distal radial growth plate and of positive ulnar variance in a nonelite gymnast population, we administered a radio graphic survey and questionnaire to 44 skeletally im mature nonelite gymnasts (27 girls and 17 boys). The subjects trained an average of 11.9 hours per week. Radiographic findings consistent with stress injury of the distal radial physis were found in 25% (11 of 44) of participants. Ulnar variance was found to be more positive in the gymnasts when compared with age- predicted norms. An average side-to-side difference in ulnar variance of 0.9 mm was observed. Radiographic findings of stress injury to the growth plate and the amount of ulnar variance were not associated with age, sex, training intensity, wrist pain, height, or weight. There was also no significant relationship between ulnar variance and radiographic findings. The mean ulnar variance in nonelite gymnasts was between that measured for elite gymnasts and nongymnasts. These results indicate that stress injury of the distal radial growth plate occurs in a significant percentage of non elite gymnasts. It also appears that ulnar variance is more positive than would otherwise be predicted, sug gesting growth inhibition of the distal radius, a growth stimulation of the ulna, or a combination of both.
Anterior Cruciate Ligament Reconstruction with Autogenous Patellar Tendon Graft Followed by Accelerated Rehabilitation
Authors: Shelbourne K. Donald , Gray Tinker
Published: June 2007

We sought to determine the long-term results of 1057 consecutive patients who underwent an anterior cruci ate ligament reconstruction with an autogenous patel lar tendon graft from 1987 through 1993 and who followed an accelerated rehabilitation program. The patients were followed prospectively and objective physical examination data were obtained on 806 pa tients at a mean of 4.0 years postoperatively. Subjec tive follow-up data were obtained on 948 patients at a mean of 4.4 years postoperatively. The mean final range of motion was 5°/0°/140°. The mean manual maximum KT-1000 arthrometer score was 2.0 ± 1.5 mm. Isokinetic quadriceps muscle strength testing re vealed a mean of 94% strength after acute reconstruc tions and 91% strength after chronic reconstructions. International Knee Documentation Committee evalua tion after acute reconstruction rated 42% of knees as normal, 47% as near normal, 10% as abnormal, and 1% as severely abnormal. The same evaluation after chronic reconstruction rated 41% of knees as normal, 44% as near normal, 14% as abnormal, and 1% as severely abnormal. Radiographically, 94% of acute knees and 89% of chronic knees had no joint space narrowing. Subjective modified Noyes questionnaire results showed a mean score of 93.2 ± 7.9 points. The mean time for patients to return to sport-specific activ ities was 6.2 weeks and to athletic competition at full capacity was 6.2 months postoperatively. In the long- term, patients exhibited full range of motion, excellent stability, good strength, and a return of full function in most cases.
Assessment of Failed Arthroscopic Anterior Labral Repairs
Authors: Mologne Timothy S. , McBride Mark T. , Lapoint John M.
Published: June 2007

To assess capsulolabral lesions present in patients after unsuccessful arthroscopic procedures, we re viewed the records of 20 patients who had undergone open shoulder procedures after unsuccessful arthro scopic Bankart procedures for chronic shoulder insta bility. The Bankart lesion had initially been repaired arthroscopically by transglenoid sutures ( N = 10), bio absorbable tacks ( N = 7), suture anchors ( N = 2), or arthroscopic screws ( N = 1). Five of the 20 patients (25%) had reinjuries to the shoulder after the arthro scopic procedure. The average time from the arthro scopic to the open procedure was 17.9 months. Over all, 12 of the 20 patients (60%) had healed Bankart lesions at the time of open surgery. Eight of the 20 patients (40%) were found to have persistent Bankart lesions, and 15 of the 20 patients (75%) were found to have redundant anterior capsules. The presence of a persistent Bankart lesion significantly correlated with postarthroscopic dislocation, and the presence of cap sular laxity significantly correlated with postarthro scopic subluxation. We concluded that capsular laxity is difficult to quantify arthroscopically and is present in a significant percentage of patients with chronic trau matic shoulder instability. Failure to successfully treat either the Bankart lesion or capsular laxity at the time of an arthroscopic Bankart procedure may lead to post operative instability.
Popliteomeniscal Fasciculi and Lateral Meniscal Stability
Authors: Simonian Peter T. , Sussmann Patrick S. , van Trommel Michiel , Wickiewicz Thomas L. , Warren Russell F.
Published: June 2007

In an attempt to understand better the contribution of the anteroinferior and posterosuperior popliteomenis cal fasciculi to lateral meniscus stability, we objectively evaluated the stability of the lateral meniscus before and after sequentially sectioning these fasciculi. In the biomechanical model, we attempted to account for the inherent limitations of arthroscopic evaluation of lateral meniscal stability. When the fasciculi were intact, the average lateral meniscal motion with a 10-N load was 3.6 mm. When the anteroinferior fascicle was dis rupted, the average lateral meniscal motion with a 10-N load was 5.4 mm. The mean increase in motion from the intact state was 1.8 mm or 50%, which was significant. When both fasciculi were disrupted, the average lateral meniscal motion with 10-N load was 6.4 mm. The mean increase in motion from the intact state was 2.8 mm or 78% and from the single fascicle disruption state was 1.0 mm or 18%, both differences were significant. The meniscus did not become locked with any of these loading trials, and it spontaneously reduced to the original position when unloaded. Both fasciculi make significant contributions to meniscal sta bility. Even though the meniscus never became locked in the joint when loaded during this study, with the variable loads seen with normal activities mechanical symptoms might be expected when meniscal motion is almost double. An increase in lateral meniscal motion at the time of surgery may aid in the diagnosis of fasciculi disruption, despite normal meniscal structure on magnetic resonance images and at arthroscopic visualization.
The Clinical Importance of the Anaerobic Energy System and Its Assessment in Human Performance
Authors: Cahill Bernard R. , Misner James E. , Boileau Richard A.
Published: June 2007

The anaerobic energy system is involved in providing energy for all forms of physical activity. The relevance of this system to human performance and physical fitness throughout the age spectrum is underscored here and contrasted with the aerobic energy system. The anaerobic system responds to high-intensity train ing with biochemical, neural, and anatomic adapta tions. Unlike the aerobic system, this response tends to be primarily a local phenomenon with little systemic adaptation. An important factor distinguishing anaero bic training from aerobic training is the intensity of the exercise dose. For anaerobic training to occur, the dose must be of high intensity and performed to near- exhaustion. The anaerobic system can be indirectly assessed by performance tests, such as a vertical jump or stair climb, or more directly by supramaximal bicycle tests. The impact of recent research regarding the trainability of the anaerobic system, particularly in the elderly population, is encouraging. The elderly re spond to anaerobic training and, as a result, their in dependence, quality of life, and safety from falls can be improved. While little is known about anaerobic reha bilitation after injury, it is known that isokinetic and performance tests may be considered normal after rehabilitation, despite incomplete rehabilitation of the anaerobic system. Thus, appropriate application of the anaerobic system assessments and training principles is an important aspect of sports medicine practice.
Athletics and Osteoarthritis
Authors: Buckwalter Joseph A. , Lane Nancy E.
Published: June 2007

Athletes, and an increasing number of middle aged and older people who want to participate in athletics, may question whether regular vigorous physical activ ity increases their risk of developing osteoarthritis. To answer this, the clinical syndrome of osteoarthritis must be distinguished from periarticular soft tissue pain associated with activity and from the development of osteophytes. Sports that subject joints to repetitive high levels of impact and torsional loading increase the risk of articular cartilage degeneration and the resulting clinical syndrome of osteoarthritis. However, moderate habitual exercise does not increase the risk of osteo arthritis ; selected sports improve strength and mobility in older people and people with mild and moderate osteoarthritis. People with abnormal joint anatomy or alignment, previous significant joint injury or surgery, joint instability, above-average body weight, distur bances of joint or muscle innervation or inadequate muscle strength probably have increased risk of osteo arthritis. These people and those with early osteoar thritis can benefit from regular physical activity, but they should have a careful evaluation of their joint structure and function before participation. They should consider measures that decrease the intensity and frequency of impact and torsional loading of joints, including use of sports equipment that decreases joint impact loading, maintaining or improving muscle strength, tone, and general conditioning so that muscle contractions help protect joints from injury and high impact, and decreasing body weight.
Social Relations and the Keynesian Multiplier
Authors: De Angelis Massimo
Published: June 2007

This paper offers a reading of the simple Keynesian multiplier through Marx's lenses. The objective is to make explicit, for the Keynesian multiplier, what from a Marxian perspective should be made explicit in any discourse about the capitalist economy, namely the role of the social relations of production. Since within given historical periods social relations are expressed in institutional forms, my analysis also gives some general insights about the basic institutional requirements assumed within the general Keynesian framework, requirements without which the Keynesian multiplier could not be operational. Finally, the paper also briefly outlines some important policy implications by comparing the main tenets of a Keynesian, neoliberal, and radical agenda for employment creation.
An Empirical Analysis of the Relationship between Human Development and Quasi-Public Goods
Authors: Richards Donald G.
Published: June 2007

This paper empirically examines the proposition that levels of social welfare are related to a country's ability to provide itself with quasi-public goods. It also argues that less developed countries in recent years have been forced to reduce public spending on such goods as a result of the need to service external debt obligations. The result for these countries then is a reduction in broad-based social welfare.
The Living Wage in Baltimore: Impacts and Reflections
Authors: Schoenberger Erica
Published: June 2007

Living wage laws, it has been argued, will unavoidably generate significant fiscal impacts on the affected jurisdictions and negative outcomes in terms of economic development. In Baltimore, to date, the fiscal impacts have been trivial. The paper explores why this might be the case and whether this is a wholly desirable outcome. It also examines how the living wage may contribute to economic development in distressed urban areas.
Technical Change and the Evolution of Class Conscious Norms
Authors: Matthews Peter Hans
Published: June 2007

Using a variant of the Michl-Baldani (2000) model of technical change as a strategic choice, this paper describes alternative foundations for the achievement of "positive class consciousness." The first is based on the Folk Theorem(s) of repeated games, while the second views the robust establishment of certain norms as the prerequisite for such conciousness.