Relationship between shoulder rotation deficit and elbow instability in healthy baseball players.

BACKGROUND: Elbow valgus instability is a risk factor for elbow medial collateral ligament injury. This study aimed to investigate the relationship between shoulder range of motion and elbow valgus instability using an ultrasound imaging system. A questionnaire and ultrasound examination were used for the study. METHODS: Thirty-seven high school baseball players (15-18 years) with no history of shoulder or elbow disorders were included. Shoulder range of motion was measured at 90° of adduction, 10° of horizontal adduction, and 90° of elbow flexion in the supine resting position. To evaluate elbow valgus instability, an ultrasound imaging system was used to measure the shortest distance from the apex of the ulnar capitulum to the humeral glenoid with 2.5 kg of valgus stress applied to the ulnohumeral joint. The presence of elbow valgus instability was determined by the value obtained by subtracting the joint space distance on the non-throwing side from that on the throwing side. Student's t-test was applied for the range of shoulder rotation between the two groups, and Pearson's correlation coefficient was used for the relationship between the range of shoulder rotation and elbow instability. Statistical significance was set at 5%. RESULTS: The range of internal and total shoulder rotation was significantly lower in participants with elbow valgus instability than those without elbow valgus instability (P<0.001). In addition, a significant moderate correlation was found in the range of internal (r=0.608, P<0.001) and total shoulder (r=0.479, P<0.001) rotations. CONCLUSIONS: Decreased shoulder range of motion may affect elbow valgus instability.

Effect of introducing ultrasonography in medical examinations for elbow injuries among young baseball players.

PURPOSE: This study investigated the usefulness of ultrasonography in medical examinations for detecting elbow injuries, especially capitellar osteochondritis dissecans, among young baseball players. METHODS: Players with current or previous elbow joint pain were enrolled. Medical examinations (range of motion, tenderness, and stress tests) were performed with (2012-2016) or without (2007-2011) ultrasonography. Players with abnormal examination results were advised to undergo additional examinations at a local orthopedic clinic. Differences in the rates of capitellar osteochondritis dissecans detection, secondary examination, and elbow injury prevalence were compared between players who did and did not undergo ultrasonography. RESULTS: We identified 1045 baseball players, aged 9-12 years, who required medical examinations for elbow injuries. Medical examinations without ultrasonography were performed in 346 players (group A), and examinations with ultrasonography were performed in 556 players (group B). Capitellar osteochondritis dissecans was present in 0.3% (1/346) of group A players and 3.0% (17/556) of group B players (p = 0.003). The secondary examination consultation rates were 51.2% (62/121) and 66.0% (270/409) in groups A and B, respectively (p = 0.004). CONCLUSION: Ultrasonography performed as a part of a medical examination can help detect elbow injuries, especially capitellar osteochondritis dissecans, in baseball players. Using ultrasonography in conjunction with medical examinations may contribute to a better understanding of elbow injuries in baseball players and improve consultation rates. Thus, ultrasonography is essential for the evaluation of elbow injuries in young baseball players.

Injuries associated with Japanese high-school men's volleyball: a two-year survey and analysis.

[Purpose] There are many factors associated with sports injuries in volleyball that remain unclear; therefore, many of these injuries are still not being effectively prevented. This study aimed to help effectively prevent injuries among and provide conditioning guidance to participants of a high-school men's volleyball team. [Participants and Methods] The participants were 36 males of a high-school men's volleyball team, and the circumstances of injury occurrence, injury type, injury site, exposure time, and injury rate per 1,000 player-hours were evaluated among these participants. [Results] Over the 2 year period, 68 injuries occurred, and the injury rate was 1.51/1,000 player-hours. Specifically, the injuries comprised 40 cases of trauma (58.8%) and 28 cases of disorders (41.2%). Additionally, injuries occurring during training tended to be disorders, and injuries occurring during matches tended to be traumas. The most common site of injury was the ankle joint. [Conclusion] The results suggest that it is important for players to have appropriate knowledge about the injuries, acquire accurate form, and undergo various types of site-specific training in order to prevent injury. In the future, the causes and circumstances of occurrence of injury must be verified in a larger number of participants.

Arthroscopic treatment of symptomatic lateral synovial plica of the knee.

INTRODUCTION: Synovial plicae are often observed when performing arthroscopic surgery, but their pathological nature and the necessity for treatment are still controversial. There are few reports regarding lateral synovial plicae because it is considered extremely rare. The purpose of this study was to report the clinical outcomes of athletes with symptomatic lateral synovial plicae who underwent arthroscopic surgery. METHODS: Ten patients with lateral synovial plica underwent arthroscopic surgery. Of the 10 patients, 5 were male and 5 were female, and their average age was 19.1 years. The chief symptoms were anterolateral knee pain, limited range of motion due to pain, and catching. All patients failed nonoperative management. RESULTS: The average period between the onset of lateral synovial plica syndrome and the knee surgery was 5.6 months. The average follow-up period after surgery was 8.4 months. The arthroscopic findings revealed that a plica-like structure existed in the lateral patellofemoral joint. After surgery, pain and limited range of joint motion were improved in all cases and catching and locking disappeared. No complications were observed; however, the pain relapsed after surgery in one patient who had slow onset. In this patient, another resection of the synovial plica provided symptomatic improvement. CONCLUSIONS: Arthroscopic resection of symptomatic lateral synovial plicae was performed with good results. Lateral synovial plica syndrome is a rare condition. However, when treating athletes with anterolateral knee pain, lateral synovial plicae should be considered.

Psychological traits regarding competitiveness are related to the incidence of anterior cruciate ligament injury in high school female athletes.

BACKGROUND: The purpose of this study was to investigate the relationship between psychological competitive ability and the incidence of noncontact ACL injuries among high school female athletes. METHODS: A three-year prospective cohort study was conducted using 300 15-year-old high school female athletes with no previous injuries or symptoms in their lower limbs (106 handball players and 194 basketball players). At baseline, their psychological competitive abilities were assessed using a self-administered questionnaire-the Diagnostic Inventory of Psychological Competitive Ability (DIPCA.3). After the baseline examination was performed at high school entry, all players were prospectively followed for 36months to document any subsequent incidence of ACL injury, according to their coaches. An unpaired t-test with Welch's correction was performed to compare the differences in the psychological competitive abilities between the injured and uninjured players. RESULTS: Of the 300 players, 25 (8.3%) experienced a noncontact ACL injury during the three-year observation period. The injured players had significantly higher total DIPCA.3 scores for psychological competitive ability than the uninjured players (169.9±18.8 vs. 159.2±21.6, P=.036). Additionally, the injured players had significantly higher scores than the uninjured players in the following categories: aggressiveness, volition for self-realization, volition for winning, judgment, and cooperation. However, no significant differences were observed in patience, self-control, ability to relax, concentration, confidence, decision, and predictive ability. CONCLUSIONS: High psychological competitive ability was associated with the incidence of noncontact ACL injuries in high school female athletes. LEVEL OF EVIDENCE: Level II (prospective cohort study).

Adipose-Derived Regenerative Cells Promote Tendon-Bone Healing in a Rabbit Model.

PURPOSE: To evaluate the therapeutic effect of adipose-derived regenerative cell (ADRC) administration on tendon-bone healing in a rabbit anterior cruciate ligament (ACL) reconstruction model. METHODS: ACL reconstruction with semitendinosus tendon autograft was performed in the right knees of adult white rabbits. Eighty rabbits were divided into 2 groups: the treatment group, in which the graft was coated with ADRCs mixed in a fibrin glue carrier during surgery, and the control group, in which the graft was coated with fibrin glue only. At 2, 4, 6, 8, and 12 weeks postoperatively, 8 rabbits were killed in each group. Three were used for histologic evaluation at the tendon-bone interface and 5 for biomechanical examination. RESULTS: On histologic analysis, chondroid cells appeared more orderly and more regular in size and shape and Sharpey-like fibers, which connected the tendon graft and bone tissue, appeared earlier in ADRC-treated tissues than in control tissues. On biomechanical analysis, the ultimate failure load in the ADRC-treated group was significantly greater than that in the control group at 2 weeks (29.5 ± 7.2 N v 20.9 ± 2.7 N, P = .016) and 4 weeks (32.3 ± 3.9 N v 22.8 ± 5.4 N, P = .016). Stiffness was significantly higher in the ADRC-treated group than in the control group at 6 weeks (21.7 ± 5.9 N/mm v 12.6 ± 4.9 N/mm, P = .037). Although the ultimate failure load and stiffness of the ADRC-treated limbs were higher than those of the limbs in the control group at 8 and 12 weeks, these differences were not significant. CONCLUSIONS: Local administration of ADRCs promoted the early healing process at the tendon-bone junction, both histologically and mechanically, in a rabbit ACL reconstruction model. CLINICAL RELEVANCE: ADRCs could be used to enhance graft healing in ACL reconstruction.

Technique of anatomical single bundle ACL reconstruction with rounded rectangle femoral dilator.

BACKGROUND: This study aimed to present a new technique for anatomical single bundle anterior cruciate ligament (ACL) reconstruction. We developed an original rounded rectangular dilator set to create rounded rectangular femoral tunnels. This technique can increase the femoral tunnel size without roof impingement, and has the potential to reduce the graft failure rate. We investigated the tunnel position and the incidence of intraoperative complications. METHOD: The presented technique is anatomical single bundle ACL reconstruction using a semitendinosus graft (with or without the gracilis tendon). The tunnel was drilled via an additional medial portal. Rounded rectangular tunnels were created using a special dilator. Tibial tunnels were created using conventional rounded tunnels. Fixation was achieved using a suspensory device on the femoral side and a plate and screw on the tibial side. PATIENTS: Fifty patients underwent this surgery, and intraoperative complications were investigated. The femoral tunnel positions were documented postoperatively from computed tomography scans using the quadrant method. The tibial tunnel positions (anterior-to-posterior, medial-to-lateral) were documented using intraoperative X-ray scans. RESULTS: Only one patient had a partial posterior tunnel wall blowout. The femoral tunnel length varied between 30 and 40mm (mean, 34.9±3.3mm). All femoral and tibial tunnels were located within the area of the anatomical ACL insertions. CONCLUSION: We did not experience any serious intraoperative complications during anatomical single bundle ACL reconstruction using a rounded rectangle dilator, and the resulting locations of the femoral and tibial tunnels were within the anatomical ACL footprint. LEVEL OF EVIDENCE: Level IV.

Grafted tendon healing in femoral and tibial tunnels after anterior cruciate ligament reconstruction.

PURPOSE: To evaluate tendon-to-bone healing after anterior cruciate ligament (ACL) reconstruction in the fibrous interzone (FIZ) of the femoral and tibial tunnels using magnetic resonance imaging (MRI). METHODS: Five men and 5 women (mean age, 29 years) underwent arthroscopic ACL reconstruction by a single surgeon, using the semitendinosus and gracilis tendon. The tendon-to-bone healing in the FIZ was evaluated using sagittal and coronal MRI at 1, 3, 6, 9, 12, and 24 weeks, with the knee flexed at 60º and the tendon graft straight in both images. The signal intensity of the FIZ was visually assessed by comparing it with anatomic landmarks in the same patient's knee, and classified into 4 grades. It was grade 3 when similar to that of the patellar tendon, grade 2 when similar to that of skeletal muscle, grade 1 when greater than that of muscle but less than that of joint fluid, and grade 0 when similar to that of joint fluid. At 24 weeks, subjective and objective functional outcomes were evaluated using the Lysholm score and the International Knee Documentation Committee score. RESULTS: At 24 weeks, no patient had knee laxity. All patients had an International Knee Documentation Committee score of A, and their mean Lysholm score was 98.5. In the femoral tunnel, the FIZ did not change during the first 9 weeks (in particular the anterior part), but healing occurred rapidly thereafter. In the tibial tunnel, the FIZ healed over time in all locations, and healing was complete in the lateral and posterior parts at 12 weeks, and in all locations at 24 weeks. The mean signal intensity grade was significantly higher in the tibial than femoral FIZ at 3 to 12 weeks (p<0.01). CONCLUSION: After ACL reconstruction, the tendon-to- bone healing in the FIZ of the tibial tunnel was faster than that of the femoral tunnel.

Oblique coronal and oblique sagittal MRI for diagnosis of anterior cruciate ligament tears and evaluation of anterior cruciate ligament remnant tissue.

BACKGROUND: The purpose of this study was to investigate the efficacy of additional oblique magnetic resonance imaging (MRI) for the diagnosis of anterior cruciate ligament (ACL) tear and evaluation of ACL remnant tissue. METHODS: We retrospectively reviewed the records of 54 knees. Three independent readers evaluated the MR images by the use of three methods: orthogonal sagittal images only (method A); orthogonal sagittal and additional oblique sagittal images (method B); and orthogonal sagittal and oblique coronal images (method C). The sensitivity, specificity, and accuracy for the diagnosis of an ACL tear and the detection of the condition of the ACL remnant tissue by the use of each method were calculated in comparison with arthroscopic findings as the reference standard. RESULTS: The arthroscopic records revealed 27 knees with intact ACLs and 27 with torn ACLs. Among the 27 knees with torn ACLs, 9 did not have continuous remnant tissue and 18 had certain remnant tissue attached to the femur or the posterior cruciate ligament. The specificities and accuracies of methods B and C for diagnosing an ACL tear were higher than those for method A. The sensitivity, specificity, and accuracy of method C for the detection of ACL remnant tissue were higher than those for method A and B. CONCLUSIONS: Additional use of oblique MRI improved the accuracy of diagnosis of ACL tear and showed a reasonable level of efficacy in detecting ACL remnant tissue. LEVEL OF EVIDENCE: Level IV (case series).

Relationship between the skeletal maturation of the distal attachment of the patellar tendon and physical features in preadolescent male football players.

PURPOSE: The aim of this study was to compare ultrasonography stages of the tibial tuberosity development and physical features. METHODS: This study examined 200 knees in 100 male football players aged 10-15 years. Tibial tuberosity development on ultrasonography was divided into 3 stages: Sonolucent stage (stage S), Individual stage (stage I), and Connective stage (stage C). Age, height, quadriceps and hamstring muscle tightness, and muscle strength in knee extension and flexion were determined. These findings were compared with the respective stages of development. RESULTS: The tibial tuberosity was stage S in 27 knees, stage I in 69 knees, and stage C in 104 knees, with right and left sides at the same stage in 95 %. Average age and height significantly increased with advancing tibial tuberosity development. Quadriceps tightness increased with tibial tuberosity development. Hamstring tightness decreased with development. The strength of both knee extension and flexion increased with advancing development, with a greater change seen in knee extension, hamstring/quadriceps ratio: stage C, 0.74; stage A, 0.64; stage E, 0.53. CONCLUSIONS: Osgood-Schlatter pathogenesis reportedly involves increased quadriceps tightness with rapidly increasing femoral length during tibial tuberosity development. In this study, it was confirmed that quadriceps tightness increased, yet hamstring tightness decreased, suggesting that quadriceps tightness is not due to femoral length alone. Other factors, including muscle strength, may be involved. The study shows that thigh muscle tightness and thigh muscle performance change with the skeletal maturation of the distal attachment of the patellar tendon. These results add new information to the pathogenesis of Osgood-Schlatter disease.

Whole body muscle activity during the FIFA 11+ program evaluated by positron emission tomography.

PURPOSE: This study investigated the effect of the FIFA 11+ warm-up program on whole body muscle activity using positron emission tomography. METHODS: Ten healthy male volunteers were divided into a control group and a group that performed injury prevention exercises (The 11+). The subjects of the control group were placed in a sitting position for 20 min and 37 MBq of (18)F-fluorodeoxyglucose (FDG) was injected intravenously. The subjects then remained seated for 45 min. The subjects of the exercise group performed part 2 of the 11+for 20 min, after which FDG was injected. They then performed part 2 of the 11+for 20 min, and rested for 25 min in a sitting position. Positron emission tomography-computed tomography images were obtained 50 min after FDG injection in each group. Regions of interest were defined within 30 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume. RESULTS: FDG accumulation within the abdominal rectus, gluteus medius and minimus were significantly higher in the exercise group than in the control group (P<0.05). CONCLUSION: The hip abductor muscles and abdominal rectus were active during part 2 of the FIFA 11+ program.

Outcomes and failure factors in surgical treatment for osteochondritis dissecans of the capitellum.

BACKGROUND: Osteochondritis dissecans (OCD) of the capitellum is an intra-articular lesion and one of the leading causes of permanent elbow disability. The treatment of advanced capitellar OCD remains challenging because of the limited potential of the articular cartilage for self-repair. The purpose of this study was to investigate the outcome of surgical treatment for OCD of the capitellum. METHODS: From 2000 to 2010, 32 male patients who had advanced lesions of capitellar OCD were treated operatively. The mean age of the patients was 14.4 years at the time of surgery. Twenty-nine patients played baseball and 3 played other sports. The lesions were of the centralized type in 9 patients, the lateral type in 4 patients, and the widespread type in 19 patients. For the surgical procedure, osteochondral peg fixation was selected for 13 patients and osteochondral autograft transplantation for 19 patients. Clinical outcome was measured with the elbow rating system including range of motion, and the number of patients who returned to active sports participation within 1 year after surgery was determined. RESULTS: The mean total arc of elbow motion increased from 123±17 degrees preoperatively to 132±14 degrees postoperatively. The mean clinical score improved significantly from 133±24 to 177±27. Within the first year after surgery, 81.3% of the patients returned to active sports playing. However, 4 of 8 patients (50%) in which osteochondral peg fixation was performed for lesions of the lateral widespread type required reoperation. CONCLUSIONS: Our results indicate that osteochondral peg fixation and osteochondral autograft transplantation may improve elbow rating score, and may facilitate a return to active sports participation. However, osteochondral peg fixation may be insufficient for lesions of the widespread type because of their poor stability. The large lateral condyle lesions had a worse outcome, and future studies will need to develop improved treatment for these defects. LEVEL OF EVIDENCE: Level IV (case series).

Roles of ACL remnants in knee stability.

PURPOSE: This study evaluated knee laxity in anterior tibial translation and rotation following removal of anterior cruciate ligament (ACL) remnants using a computer navigation system. METHODS: This prospective study included 50 knees undergoing primary ACL reconstruction using a navigation system. ACL remnants were classified into four morphologic types: Type 1, bridging between the roof of the intercondylar notch and tibia; Type 2, bridging between the posterior cruciate ligament and tibia; Type 3, bridging between the anatomical insertions of the ACL on the lateral wall of the femoral condyle and the tibia; and Type 4, no bridging of ACL remnants. Anterior tibial translation and rotatory laxity were measured before and after remnant resection using a navigation system at 30°, 60°, and 90° of knee flexion. The amount of change in anterior tibial translation and rotatory laxity of each type was compared among the types. RESULTS: The different morphologic types of ACL remnants were as follows: Type 1, 15 knees; Type 2, 9 knees; Type 3, 6 knees; and Type 4, 20 knees. The amount of change in anterior tibial translation and rotatory laxity at 30° knee flexion in Type 3 was significantly larger than in the other types. There were no significant differences in either tibial translation or rotatory laxity at 60° and 90° knee flexion among the types. CONCLUSIONS: In Type 3, ACL remnants contributed to anteroposterior and rotatory knee laxity evaluated at 30° knee flexion. The bridging point of the remnants is important to knee laxity. The Type 3 remnant should be preserved as much as possible when ACL reconstruction surgery is performed. LEVEL OF EVIDENCE: Prognostic study, level II.