Purpose: Professional soccer players performed a preseason isokinetic testing aimed at determining whether (1) strength variables could be predictors of subsequent hamstring strain and (2) normalization of strength imbalances could reduce the incidence of hamstring injury.

Study Design: Cohort study (prognosis); Level of evidence, 1.

Methods: A standardized concentric and eccentric isokinetic assessment was used to identify soccer players with strength imbalances. Subjects were classified among 4 subsets according to the imbalance management content. Recording subsequent hamstring injuries allowed us to define injury frequencies and relative risks between groups.

Results: Of 687 players isokinetically tested in preseason, a complete follow-up was obtained in 462 players, for whom 35 hamstring injuries were recorded. The rate of muscle injury was significantly increased in subjects with untreated strength imbalances in comparison with players showing no imbalance in preseason (relative risk = 4.66; 95% confidence interval: 2.01–10.8). The risk of injury remained significantly higher in players with strength imbalances who had subsequent compensating training but no final isokinetic control test than in players without imbalances (relative risk = 2.89; 95% confidence interval: 1.00–8.32). Conversely, normalizing the isokinetic parameters reduced the risk factor for injury to that observed in players without imbalances (relative risk = 1.43; 95% confidence interval: 0.44–4.71).

Conclusion: The outcomes showed that isokinetic intervention gives rise to the preseason detection of strength imbalances, a factor that increases the risk of hamstring injury. Restoring a normal strength profile decreases the muscle injury incidence.

Hypothesis: A simple on-field alternative warm-up program can reduce noncontact ACL injuries.

Study Design: Randomized controlled trial (clustered); Level of evidence, 1.

Methods: Participating National Collegiate Athletic Association Division I women’s soccer teams were assigned randomly to intervention or control groups. Intervention teams were asked to perform the program 3 times per week during the fall 2002 season. All teams reported athletes’ participation in games and practices and any knee injuries. Injury rates were calculated based on athlete exposures, expressed as rate per 1000 athlete exposures. A z statistic was used for rate ratio comparisons.

Results: Sixty-one teams with 1435 athletes completed the study (852 control athletes; 583 intervention). The overall anterior cruciate ligament injury rate among intervention athletes was 1.7 times less than in control athletes (0.199 vs 0.340; P = .198; 41% decrease). Noncontact anterior cruciate ligament injury rate among intervention athletes was 3.3 times less than in control athletes (0.057 vs 0.189; P = .066; 70% decrease). No anterior cruciate ligament injuries occurred among intervention athletes during practice versus 6 among control athletes (P = .014). Game-related noncontact anterior cruciate ligament injury rates in intervention athletes were reduced by more than half (0.233 vs 0.564; P = .218). Intervention athletes with a history of anterior cruciate ligament injury were significantly less likely to suffer another anterior cruciate ligament injury compared with control athletes with a similar history (P = .046 for noncontact injuries).

Conclusion: This program, which focuses on neuromuscular control, appears to reduce the risk of anterior cruciate ligament injuries in collegiate female soccer players, especially those with a history of anterior cruciate ligament injury.

Purpose: To evaluate the in vitro chondrotoxicity of anesthetic formulations commonly used in pain pumps.

Study Design: Controlled laboratory study.

Methods: Freshly isolated human articular chondrocytes were cultured for 24-, 48-, and 72-hour trials in a custom bioreactor that mimics the metabolism of synovial fluid. Chondrocytes were perfused in Dulbecco’s Modified Eagle’s Medium 10% fetal bovine serum and one of the following medications: 1% lidocaine, 1% lidocaine with epinephrine, 0.25% bupivacaine, 0.25% bupivacaine with epinephrine, 0.5% bupivacaine, or 0.5% bupivacaine with epinephrine. Static and perfusion cultures with growth media were used as controls. All experiments were run in duplicate. Live/dead staining was performed, and the ratio of dead:live cells was assessed by fluorescent microscopy and histomorphometry.

Results: Significantly more chondrocyte necrosis was found in all cultures with medications containing epinephrine (P < .05) at all time points. Similar necrosis rates were exhibited in 0.25% and 0.5% bupivacaine compared with controls at 24 and 48 hours. However, 0.5% bupivacaine produced significantly more cell death at 72 hours. Similar necrosis rates were exhibited with 1% lidocaine compared to controls at 24 hours.

Conclusion: In this in vitro model, 0.25% and 0.5% bupivacaine caused minimal chondrocyte necrosis when used in pain pumps for a maximum of 48 hours. All anesthetics containing epinephrine (pH ≤4) were chondrotoxic and cannot be advocated for pain pump use. The use of 0.5% bupivacaine for greater than 48 hours is not recommended.

Clinical Relevance: The results of this study may help improve the safety of intra-articular pain pump use by examining the effects of local anesthetics on chondrocyte viability.

Purpose: This study was conducted to assess outcomes and to document anatomic characteristics of the repaired meniscus with postoperative arthrography combined with computed tomography (arthro-CT), particularly the dimensions and healing of the repaired meniscus.

Study Design: Case series; Level of evidence, 4.

Methods: Fifty-three arthroscopic meniscal repairs were prospectively evaluated between 2002 and 2004 in 2 orthopaedic departments. There were 36 medial and 17 lateral torn menisci. All ACL tears (n = 31, 58.5%) underwent reconstruction. Patients were preoperatively evaluated by magnetic resonance imaging. Clinical evaluation included International Knee Documentation Committee (IKDC) scores before the operation and 6 and 12 months afterward. Healing criteria were evaluated at 6 months by arthro-CT scan. Three parameters were evaluated—healing in thickness (Henning criteria), overall healing rate, and reduction in the width of the remaining meniscus.

Results: According to the objective IKDC score, 26 patients were graded A, 20 B, and 4 C (92% good results). The mean subjective IKDC score was 78.9 (standard deviation [SD], 16.2). According to Henning’s criteria, 58% of the menisci healed completely, 24% partially, and 18% failed. The overall healing rate was 73.1% (SD, 38.5). Twenty tears located in the posterior part had a healing rate of 59.8% (SD, 46.0). Nineteen tears extending from the posterior to the middle part had a healing rate of 79.2% (SD, 28.2). Isolated tears located in the posterior part had a lower healing rate (P < .05). There was a 9% ± 1.2% reduction in the width of the remaining medial meniscus in the middle and posterior repaired portions (P < .02). There was a 15% ± 14% reduction in the width of the remaining lateral meniscus in the middle repaired portion (P < .01). Complete healing of the posterior segment was associated with reduction in the width of the meniscus (P < .04).

Conclusion: A modern technique using all-inside fixation or outside-in sutures provided good clinical and anatomic outcomes. No statistically significant effect on ACL reconstruction or laterality (medial vs lateral) on overall healing after meniscal repair was identified. Partial healing occurred often, with a stable tear on a narrowed and painless meniscus. The posterior segment healing rate remained low, suggesting a need for further technical improvements.

Hypothesis: Rotator cuff tears repaired using the transosseous-equivalent suture-bridge technique will show a higher intact rate on postoperative magnetic resonance imaging (MRI) evaluation.

Study Design: Case series; Level of evidence, 4.

Methods: The first 25 patients who underwent arthroscopic rotator cuff repair using the transosseous-equivalent suture-bridge technique underwent MRI evaluation of the postoperative shoulder. Minimum follow-up was 1 year. Demographic, clinical, and surgical factors, including tear size, were evaluated.

Results: Postoperative MRI demonstrated intact surgical repair sites in 22 of 25 patients (88%). Tears limited to the supraspinatus tendon were intact in 16 of 18 patients (89%). Tears of the supraspinatus involving part or all of the infraspinatus showed an 86% intact rate (6 of 7 patients). Of these tears, 3 were considered massive (complete 2-tendon or greater). These demonstrated an intact cuff on MRI.

Conclusions: The transosseous-equivalent suture-bridge technique demonstrates a high healing rate on imaging studies at 1 year. Of the first 25 patients repaired with the technique, 88% had an intact rotator cuff repair on MRI evaluation. This indicates excellent cuff healing, as judged by the intact repair sites, compared with most standard arthroscopic rotator cuff repair series. In this early report of the technique, a persistent tear could not be correlated with age or initial tear size; however, this may be due to the relatively small sample size.

Hypothesis: Single-row rotator cuff repairs with modified suture configurations have similar failure loads and gap formations as double-row reconstructions.

Study Design: Controlled laboratory study.

Methods: We created 1 x 2-cm defects in 48 porcine infraspinatus tendons. Reconstructions were then performed with 4 single-row repairs and 2 double-row repairs. The single-row repairs included transosseous simple sutures; double-loaded corkscrew anchors in either a double mattress or modified Mason-Allen suture repair; and the Magnum Knotless Fixation Implant with an inclined mattress. Double-row repairs were either with Bio-Corkscrew FT using modified Mason-Allen stitches or a combination of Bio-Corkscrew FT and PushLock anchors using the SutureBridge Technique. During cyclic load (10 N to 60–200 N), gap formation was measured, and finally, ultimate load to failure and type of failure were recorded.

Results: Double-row double-corkscrew anchor fixation had the highest ultimate tensile strength (398 ± 98 N) compared to simple sutures (105 ± 21 N; P < .0001), single-row corkscrews using a modified Mason-Allen stitch (256 ± 73 N; P = .003) or double mattress repair (290 ± 56 N; P = .043), the Magnum Implant (163 ± 13 N; P < .0001), and double-row repair with PushLock and Bio-Corkscrew FT anchors (163 ± 59 N; P < .0001). Single-row double mattress repair was superior to transosseous sutures (P < .0001), the Magnum Implant (P = .009), and double-row repair with PushLock and Bio-Corkscrew FT anchors (P = .009). Lowest gap formation was found for double-row double-corkscrew repair (3.1 ± 0.1 mm) compared to simple sutures (8.7 ± 0.2 mm; P < .0001), the Magnum Implant (6.2 ± 2.2 mm; P = .002), double-row repair with PushLock and Bio-Corkscrew FT anchors (5.9 ± 0.9 mm; P = .008), and corkscrews with modified Mason-Allen sutures (6.4 ± 1.3 mm; P = .001).

Conclusion: Double-row double-corkscrew anchor rotator cuff repair offered the highest failure load and smallest gap formation and provided the most secure fixation of all tested configurations. Double-loaded suture anchors using modified suture configurations achieved superior results in failure load and gap formation compared to simple suture repair and showed similar loads and gap formation with double-row repair using PushLock and Bio-Corkscrew FT anchors.

Clinical Relevance: Single-row repair with modified suture configurations may lead to results comparable to several double-row fixations. If double-row repair is used, modified stitches might further minimize gap formation and increase failure load.

Purpose: To evaluate the outcome of massive rotator cuff tears repaired using the biceps interposition technique.

Study Design: Case series; Level of evidence, 4.

Methods: Between April 2000 and April 2004, 31 shoulders with irreparable massive rotator cuff tears and associated degenerative lesions of the biceps tendon were included for analysis. Open procedures were performed in 15 cases (open group), while 16 patients underwent arthroscopic procedures (arthroscopic group). The mean follow-up period was 32 months (range, 24–67 months).

Results: The overall University of California at Los Angeles score at the last follow-up was 31.1 points (range, 21–35). The clinical outcome was excellent in 15 (48.4%) and good in 13 (41.9%) cases. Three patients (9.7%) had poor outcome. There was 1 case of reoperation in the open group for a retear. The mean preoperative Constant score, which was 44.6 points (range, 8–70) in the open group and 51.8 points (range, 24–70) in the arthroscopic group, improved to 80.7 points (range, 37–88) in the former and 83.5 points (range, 57–96) in the latter. The University of California at Los Angeles score improved from preoperative means of 11.3 points (range, 6–16) and 13.6 points (range, 6–19) to 29.5 points (range, 9–33) and 32.6 points (range, 21–35), respectively. However, the differences between the scores in both the categories were not statistically significant (P = .412 and .198, respectively). According to the postoperative repair integrity analyzed with use of magnetic resonance imaging in 14 of 16 cases with arthroscopic augmentation, 9 (64.3%) presented complete healing.

Conclusion: The biceps tendon interposition technique for massive rotator cuff tears offers a possible improvement in the clinical outcomes and is comparable to that of conventional repair. As well, the augmentation technique using the tenotomized biceps as potential graft for rotator cuff tears is particularly useful in bridging the gap in immobile massive rotator cuff tears with posterior defects and retraction.

Hypothesis: Granulocyte colony-stimulating factor has an effect on the maturation of bone-tendon integration of anterior cruciate ligament reconstruction.

Study Design: Controlled laboratory study.

Methods: Twenty-eight healthy adult beagle dogs underwent bilateral anterior cruciate ligament reconstruction using the ipsilateral flexor digitorum superficialis tendon and were divided into 2 groups. A granulocyte colony-stimulating factor–incorporated gelatin surrounded the graft in the granulocyte colony-stimulating factor group, and the same gelatin without granulocyte colony-stimulating factor was used as the control group. Assessment was done at 2 and 4 weeks.

Results: Histological analysis at week 2 demonstrated that, in addition to more Sharpey fibers, microvessels were significantly enhanced in the granulocyte colony-stimulating factor group’s grafts. Computed tomography at week 4 showed a significantly smaller tibial bone tunnel in the granulocyte colony-stimulating factor group. Real-time polymerase chain reaction revealed significantly elevated messenger ribonucleic acid expression levels of vascular endothelial growth factor and osteocalcin in the tibial bone tunnel and graft compared with controls. Furthermore, biomechanical testing of force during loading to ultimate failure at week 4 demonstrated a significant increase in strength in the granulocyte colony-stimulating factor group.

Conclusion: This study demonstrated that a local application of granulocyte colony-stimulating factor–incorporated gelatin significantly accelerates bone-tendon interface strength via enhanced angiogenesis and osteogenesis.

Clinical Relevance: Granulocyte colony-stimulating factor has therapeutic potential in promoting an environment conductive to angiogenesis and osteogenesis in bone tunnels.

Hypothesis: The grade of knee laxity can be used as an early predictor of the need for later reconstruction.

Study Design: Cohort study (prognosis); Level of evidence, 2.

Methods: One hundred consecutive patients with an acute arthroscopically verified total anterior cruciate ligament rupture were followed prospectively for 15 years. Lachman and pivot-shift tests were performed with the patient under general anesthesia before arthroscopy. After 3 months, the tests were repeated in an ordinary clinical setting. All patients underwent rehabilitation as the first choice of treatment. Anterior cruciate ligament reconstruction was performed only in cases of significant reinjuries (n = 16) or reparable meniscal lesions (n = 6) at a mean of 4 years after injury (range, 4 months–11 years). After 15 years, 94 patients were available for follow-up.

Results: Of the later reconstructed patients (n = 18), 82% had a high-grade Lachman test under anesthesia compared with 63% of the nonreconstructed patients (n = 45; P = .048). At 3 months, 44% of the nonreconstructed patients (n = 32) had a high-grade Lachman test compared with 82% of the reconstructed patients (n = 18; P = .007). Twenty-five patients displayed a normal pivot-shift test at 3 months, of whom 1 underwent later reconstruction (P = .009). A high-grade pivot-shift test at 3 months was associated with an 11.4 relative risk for reconstruction.

Conclusion: A positive pivot-shift test at 3 months after injury in an awake patient is the strongest predictor for the future need for reconstruction. Furthermore, a normal pivot-shift test at 3 months indicates a low risk for reconstruction and is characteristic for copers.

Hypothesis: ACL Grafts placed in anteromedial and posterolateral bundle positions will have distinct anisometric profiles and 3-dimensional obliquities. A graft placed centrally in anterior cruciate ligament insertion sites will have different obliquity and anisometry than a conventional (single-bundle) graft extending from the tibia’s posterolateral aspect to the femur’s anteromedial aspect.

Study Design: Controlled laboratory study.

Methods: Five cadaveric knees were tested. A surgical navigation system was used to create 4 virtual graft positions in the anterior cruciate ligament footprint: (1) anteromedial, (2) posterolateral, (3) central, and (4) posterolateral tibia to anteromedial femur (conventional). Obliquity at various flexion angles and anisometry of each virtual graft’s central fiber were determined.

Results: Anteromedial and posterolateral fibers are relatively parallel up to 30° of flexion. At higher degrees of flexion, the anteromedial position is more oblique in the sagittal plane, while the posterolateral position is more oblique in the axial plane. The conventional single-bundle position is significantly more vertical than the central position in multiple planes throughout the range of motion. The anteromedial fiber is most isometric, while the posterolateral fiber is the least isometric at all flexion angles. There is no significant difference in the anisometry between the central or conventional positions at any flexion angle. The posterolateral, central, and conventional fibers were longest at full extension and slackened with progressive flexion.

Conclusion: Anteromedial and posterolateral graft positions can be distinguished by sagittal and axial plane obliquity at flexion angles >30° and by anisometry measurements. Conventional positioning produces a relatively vertical graft placement compared with the central position but has similar anisometry characteristics. Our data suggest that posterolateral, central, and conventional grafts should be fixed at or near full extension to avoid excessive tightening during motion.

Clinical Relevance: This study provides anisometry and 3-dimensional obliquity data for various graft positions using surgical navigation. The failure of single-bundle anterior cruciate ligament reconstruction to restore intact knee kinematics may be partly due to the relative vertical placement of conventional grafts compared with the central anterior cruciate ligament footprint position.

Hypothesis: Some patients who experience functional instability of the ankle have substantial abnormalities of the anterior talofibular ligament despite having apparently normal lateral laxity in clinical examination.

Study Design: Case series; Level of evidence, 4.

Methods: Fourteen patients who had functional ankle instability after sprain, despite having no clinically demonstrable lateral instability, were included in this study. All subjects underwent standard stress radiography, magnetic resonance imaging, and ankle arthroscopy. These patients were treated with anatomical reconstruction of the anterior talofibular ligament.

Results: Arthroscopic assessment revealed 3 cases with no ligamentous structure with scar tissue, 9 cases with partial ligament tears and scar tissue on the disrupted anterior talofibular ligament fiber, and 2 cases of abnormal course of the ligament at the fibular or talar attachment. Magnetic resonance imaging revealed the following: 5 cases of discontinuity of the anterior talofibular ligament, 2 cases of narrowing of the anterior talofibular ligament, 4 cases of high-intensity lesion in the anterior talofibular ligament, and 3 normal cases. The mean American Orthopaedic Foot and Ankle Society Ankle Hindfoot scale score was 66.2 ± 3.2 points at preoperation and 92.3 ± 4.4 points 2 years after surgery.

Conclusion: All patients in this study with functional ankle instability, despite their having no demonstrable abnormal lateral laxity, had morphologic ligamentous abnormality on arthroscopic assessment.

Hypothesis: Systemic treatment of animals after injury of skeletal muscle with an angiotensin receptor blocker may decrease fibrosis and improve regeneration, mainly through transforming growth factor-β1 blockade, and can be used to improve skeletal muscle healing after injury.

Study Design: Controlled laboratory study.

Methods: Forty mice underwent bilateral partial gastrocnemius lacerations. Mice were assigned randomly to a control group (tap water), a low-dose angiotensin receptor blocker group (losartan, 0.05 mg/mL), or a high-dose angiotensin receptor blocker group (0.5 mg/mL). The medication was dissolved in tap water and administered enterally. Mice were sacrificed 3 or 5 weeks after injury, and the lacerated muscles were examined histologically for muscle regeneration and fibrosis.

Results: Compared with control mice at 3 and 5 weeks, angiotensin receptor blocker–treated mice exhibited a histologic dose-dependent improvement in muscle regeneration and a measurable reduction in fibrous tissue formation within the area of injury.

Conclusion: By modulating the response to local and systemic angiotensin II, angiotensin receptor blocker therapy significantly reduced fibrosis and led to an increase in the number of regenerating myofibers in acutely injured skeletal muscle. The clinical implications for this application of angiotensin receptor blockers are potentially far-reaching and include not only sports- and military-related injuries, but also diseases such as the muscular dystrophies and trauma- and surgery-related injury.

Clinical Relevance: Angiotensin receptor blockers may provide a safe, clinically available treatment for improving healing after skeletal muscle injury.

Hypothesis: The implantation of a scaffold-free, autologous de novo cartilage implant into standardized full-thickness cartilage defects of femoral condyles in sheep leads to a qualitatively better regenerative tissue than does periosteal flap alone or no treatment.

Study Design: Controlled laboratory study.

Methods: Chondral defects 4 mm in diameter (1 per sheep) were created in the center of 1 medial femoral condyle of 48 sheep. Twelve defects were allowed to heal spontaneously, 16 defects were covered with periosteal flaps alone, and 20 defects were filled with autologous de novo cartilage graft and overlaid with a periosteal flap. Differences were assessed macroscopically using the International Cartilage Repair Society score and microscopically using the International Cartilage Repair Society histological score and Mankin score at 26 and 52 weeks.

Results: The results of the International Cartilage Repair Society Cartilage repair assessment showed that the transplant group was better than was the untreated control at both time periods but not significantly different than was the periosteal flap group. Implanted groups demonstrated a marked improvement in grade of defect filling, cartilage stability, cell distribution, and matrix assessments in each method of assessment. In the transplant group, 2 defects were filled with hyaline cartilage, 5 with mixed hyaline and fibrocartilage, and 2 with fibrocartilage alone.

Conclusion: Chondral defects treated with de novo cartilage transplantation show qualitatively better microscopic and macroscopic regeneration than do those treated with periosteal flaps alone.

Clinical Relevance: Results of the current study show that third-generation autologous chondrocyte transplantation is a promising development in the field of biologic cartilage regeneration. Future studies should compare this technique with the original Brittberg technique.

Hypothesis: Ulnar collateral ligament reconstructions utilizing a semitendinosus graft and interference knot fixation will be biomechanically superior to previously reported techniques.

Study Design: Controlled laboratory study.

Methods: Thirty cadaveric elbows were stripped of all medial soft tissue superficial to the UCL. The proximal humeri were mounted on a materials testing system with the elbows flexed 90°. The intact UCL was loaded to failure at 4.5 deg/s. The torsional failure moment, torsional stiffness, and mode of failure were recorded. Three groups of 10 specimens were created. Group 1 underwent reconstruction using a palmaris tendon graft secured with interference knot fixation. Group 2 reconstructions utilized a palmaris graft and the docking technique. Group 3 specimens were reconstructed using a semitendinosus graft and interference knot fixation. All specimens were loaded to failure and the same parameters recorded.

Results: The torsional failure moments for group 1 (13.28 N·m) and group 2 (12.81 N·m) reconstructions were significantly (P < .05) inferior to that of their respective native values (21.3 N·m and 23.5 N·m). Semitendinosus reconstructions (20.5 N·m) were not significantly different (P = .24) from their native UCLs (23.0 N·m). All reconstructions were torsionally less stiff (P < .001) than the native UCL. There were no statistically significant differences in stiffness between the groups (P = .4).

Conclusion: Ulnar collateral ligament reconstruction utilizing semitendinosus graft and interference knot fixation restores the torsional strength of the intact UCL.

Clinical Relevance: Reconstructions using semitendinosus grafts may allow for accelerated rehabilitation and earlier return to competition.

Purpose: This study was conducted to evaluate the intraobserver and interobserver reliability of measurements made using kneeling stress radiography to quantify posterior knee instability.

Study Design: Case series (diagnosis); Level of evidence, 4.

Methods: One hundred thirty-two stress radiographs in 44 patients with suspected posterior knee instability were prospectively taken using the kneeling technique. The amount of posterior displacement on the radiographs was then measured independently by 3 blinded testers (an orthopaedic sports medicine faculty member, an orthopaedic chief resident, and a medical student) on 2 separate occasions. Changes in mean and intraclass correlation coefficients (ICCs) were examined to assess the intraobserver and interobserver reliability of the measurements.

Results: Intraobserver changes in displacement means were small (–0.307 mm, –0.294 mm, and +0.035 mm) and only significant for observer 1. The combined intraobserver ICC was 0.973 for the 3 observers (0.976, 0.959, and 0.981). Interobserver comparisons revealed significant differences in trial 1 between observers 2 and 3 (0.675 mm), no differences in trial 2, and significant differences between observers 1 and 2 (0.333 mm) and observers 2 and 3 (0.510 mm) in the combined trial data. The combined interobserver ICC was 0.955 for the 3 observers (0.959 and 0.951 for the 2 trials).

Conclusions: The kneeling technique for posterior cruciate ligament stress radiography provides a reproducible method to quantify posterior knee instability.

Purpose: The purpose of this study was to assess the outcome and ability of patients returning to sports after shoulder replacement surgery.

Study Design: Case series; Level of evidence, 4.

Methods: Seventy-five patients (86 shoulder replacements) who participated in sports or recreational activities before surgery were followed for a minimum of 2 years. Their preoperative and postoperative sports participation and level of competition were assessed. The frequency of their activity, modifications in activity, and length of time it took to resume sports participation after the operation were all reviewed.

Results: The mean age at follow-up was 65.5 years (range, 24–88). The average follow-up was 3.7 years (range, 2–9.4). Sixty-four percent of the patients stated that one of the reasons they had the surgery performed was participation in sports. Thirty-four of 48 of these patients (71%) demonstrated an improvement in their ability to play their sport and 50% increased their frequency of participation postoperatively. Softball athletes demonstrated the least favorable return; only 2 of 10 patients returned. Swimming, tennis, and golf were the most popular sports; participants in these sports showed the most favorable improvement and actual return. The mean time to partial return to sports was 3.6 months, and 5.8 months to full participation.

Conclusion: Patients are able to successfully return to sports after shoulder arthroplasty. Many returned with improved performance and increased frequency in participation in a timely manner.

Purpose: To develop an evidence-based recommendation for transportation of suspected spine-injured youth football players.

Study Design: Descriptive laboratory study.

Methods: Three lateral radiographs were obtained in supine to include the occiput to the cervical thoracic junction from 31 youth football players (8–14 years). Each child was imaged while wearing helmet and shoulder pads, without equipment, and with shoulder pads only. Two independent observers measured cervical spine angulation as Cobb angle from C1 to C7 and subaxial angulation from C2 to C7. We calculated intraclass correlation coefficients for intraobserver reliability analysis and compared Cobb and C2 to C7 angles between equipment conditions with t tests.

Results: Interobserver analysis showed excellent reliability among measurements. Cobb and subaxial angle measurements indicated significantly greater cervical lordosis while children wore shoulder pads only, compared with the other 2 conditions (no equipment and helmet and shoulder pads) (P ≤ .001). There was no statistically significant difference in either Cobb or C2–C7 angles between fully equipped (helmet + shoulder pads) and no-equipment conditions (P >.05).

Conclusions: Equipment removal for the youth football athlete with suspected cervical spine injury should abide by the "all or none" policy that has been widely accepted for adult athletes. Helmet and shoulder pads should be left in place during emergency transport of the suspected spine-injured youth athlete.

Clinical Relevance: Despite differences in head to torso size ratios between youth and adult players, helmet removal alone is not recommended for either during emergency transportation.

Hypothesis: Differences in lower extremity mechanics during single-legged jumps between female athletes with and without patellofemoral pain will increase after exertion.

Study Design: Controlled laboratory study.

Methods: Twenty women with patellofemoral pain and 20 healthy female controls participated in a functional lower extremity exertion protocol of repetitive single-legged jumps. Pain, exertion, hip and trunk strength, and 3-dimensional lower extremity joint mechanics were recorded at the beginning and end of the protocol.

Results: The patellofemoral pain group reported increased pain at the conclusion of the protocol. However, all subjects terminated the protocol due to complaints of fatigue. Mean strength measurements for the patellofemoral pain group were 24% lower for lateral trunk flexion (P = .06), 13% lower for hip abduction (P = .09), and 14% lower for hip external rotation (P = .03) than for controls. Subjects with patellofemoral pain demonstrated greater contralateral pelvic drop at the end of the exertion protocol compared with the control group (P = .003). Group differences in lower extremity mechanics, including increased hip adduction angle, hip flexion angle, hip abduction angular impulse, and decreased hip internal rotation angles, were observed among women with patellofemoral pain throughout the exertion protocol. These group differences were consistent despite increased pain for the patellofemoral pain group after exertion. Both groups demonstrated decreased jump height, hip flexion and internal rotation, knee flexion, and hip extension impulse at the end of the protocol.

Conclusion: Women with patellofemoral pain demonstrated lower extremity mechanics that differed from the healthy control group during single-legged jumping, particularly at the hip. These differences do not appear to vary with exertion level or pain among patellofemoral pain subjects during single-legged jumps.

Clinical Relevance: Lower extremity jumping mechanics appear to be consistently different among women with patellofemoral pain. Conservative treatment programs that include kinematic retraining as well as hip and trunk strengthening may improve patient outcomes and prevent recurrence of this common orthopaedic condition.

Hypothesis: Injury rates will vary with time, and injury patterns will differ between training camp practices and preseason games.

Study Design: Descriptive epidemiology study.

Methods: From 1998 to 2007, injury data were collected from 1 National Football League team during its training camp period. Injuries were recorded as a strain, sprain, concussion, contusion, fracture/dislocation, or other injury. The injury was further categorized by location on the body. Injury rates were determined based on the exposure of an athlete to a game or practice event. An athlete exposure was defined as 1 athlete participating in 1 practice or game. The injury rate was calculated as the ratio of injuries per 1000 athlete exposures.

Results: There were 72.8 (range, 58–109) injuries per year during training camp. Injuries were more common during weeks 1 and 2 than during weeks 3 to 5. The rate of injury was significantly higher during games (64.7/1000 athlete exposures) than practices (12.7/1000 athlete exposures, P < .01). The rate of season-ending injuries was also much higher in games (5.4/1000 athlete exposures) than practices (0.4/1000 athlete exposures). The most common injury during the training camp period was a knee sprain, followed by hamstring strains and contusions.

Conclusion: Muscle strains are the most common injury type in practices. Contact type injuries are most common during pre-season games, and the number of significant injuries that occur during preseason games is high.

Hypothesis: Shoulder instability in patients with type II superior labral anterior-posterior lesions may result from the associated shoulder capsular laxity rather than the superior labral anterior-posterior lesion alone.

Study Design: Controlled laboratory study.

Methods: Six cadaveric shoulders were externally rotated to 20% beyond the maximum humeral external rotation at 60° of glenohumeral abduction, which simulated 90° of shoulder abduction, to detach the superior labrum and elongate the anterior shoulder capsular ligaments. The detached labrum was then repaired to isolate the effect of the detached superior labrum and that of the capsular laxity. Rotational range of motion was measured at 60° of glenohumeral abduction. Anterior-posterior glenohumeral translation was measured at 30° and 60° of glenohumeral abduction. Superior-inferior glenohumeral translation was measured at 0° and 60° of glenohumeral abduction.

Results: The experimentally created type II superior labral anterior-posterior lesion and capsular laxity significantly increased anterior translation at 30° (mean difference, 1.0 ± 0.8 mm; P < .05) and 60° (mean difference, 2.2 ± 2.0 mm; P < .05) of glenohumeral abduction. Subsequent superior labral anterior-posterior repair restored the anterior translation but only at 30° of glenohumeral abduction (mean difference, 0.9 ± 0.6 mm; P < .05).

Conclusion: Because of the anterior capsular laxity associated with type II superior labral anterior-posterior lesions, superior labral anterior-posterior repair of the peeled-back superior labrum may not restore anterior glenohumeral translation at 90° of shoulder abduction.

Clinical Relevance: Anterior shoulder capsular laxity associated with type II superior labral anterior-posterior lesions may cause anterior shoulder instability at 90° of shoulder abduction in throwers even after superior labral anterior-posterior lesion repair.

Hypotheses: (1) There is no difference in biomechanical performance between currently used fixation methods, (2) there is no difference in incidence of complications between the 2-incision and single-incision approach, and (3) there is no difference in clinical outcomes between the 2-incision and single-incision approach.

Study Design: Systematic review; Level of evidence, 4.

Methods: The authors performed a systematic review of the literature studying treatment of the ruptured distal biceps tendon to determine optimal fixation method as well as surgical approach with lowest incidence of complications and highest proportion of satisfactory results.

Results: The review identified 8 articles that had relevant biomechanical data, 23 with relevant complication data, and 19 with relevant clinical results data. EndoButton fixation performed best in comparative biomechanical studies. There was no difference in overall incidence of complications between 2-incision approaches (16%) and single-incision approaches (18%), but there were significantly more instances of significant loss of forearm rotation with the 2-incision approach. There were significantly more unsatisfactory clinical results in the 2-incision repair group (31% vs 6%; odds ratio, 7.6; 95% confidence interval, 3.2–17.7), with the majority of unsatisfactory results in the 2-incision group due to loss of forearm rotation or rotational strength.

Conclusion: EndoButton fixation has the highest load and stiffness of currently available fixation methods. Two-incision repairs have a significantly greater proportion of unsatisfactory results than do single-incision repairs.