The American Journal of Sports Medicine

Background: Recognition and treatment of elbow conditions such as medial collateral ligament injury and posteromedial impingement are increasing in throwing athletes. Magnetic resonance imaging may provide pivotal information in the management of these athletes. Knowledge of the utility of magnetic resonance imaging has become widespread throughout the baseball community. However, data on the frequency and extent of asymptomatic magnetic resonance imaging findings in the elbows of this throwing population are lacking.

Hypothesis: Abnormalities in the throwing elbows of asymptomatic professional baseball players compared to the nonthrowing elbows are frequently seen in magnetic resonance images.

Study Design: Descriptive anatomical study.

Methods: Sixteen asymptomatic professional baseball players with no history of injury underwent bilateral elbow magnetic resonance imaging using a standardized sequencing protocol. The magnetic resonance images were reviewed, in a blinded fashion, by 2 musculoskeletal radiologists and 1 orthopaedic surgeon.

Results: Medial collateral ligament abnormalities (including thickening, signal heterogeneity, or discontinuity) were present in 87% of players’ dominant elbows. Findings consistent with posteromedial impingement were present in 13 of 16 subjects. There was a significant correlation between medial collateral ligament thickening and posteromedial subchondral sclerosis (P = .04). The throwing elbow was correctly identified in all 16 subjects. No significant correlation between magnetic resonance imaging findings and age could be detected.

Conclusions: This study demonstrates a high rate of abnormal magnetic resonance imaging findings in asymptomatic throwers’ elbows. These baseline findings must be considered when magnetic resonance imaging is being used as a factor in treatment decisions.

Background: The effect of elbow medial ulnar collateral ligament injury on posteromedial compartment contact is unknown.

Hypothesis: Medial ulnar collateral ligament injury causes altered contact area and pressure in the posteromedial compartment of the elbow.

Study Design: Controlled laboratory study.

Methods: Seven elbow cadaveric specimens were tested in an apparatus that positioned the elbow at 30° and 90° of flexion. Partial and full tears were simulated by releasing the medial ulnar collateral ligament. Pressure-sensitive film was placed in the posteromedial compartment for each condition. Valgus torques of 1.25 and 2.0 N.m were applied for each ligament condition, and kinematic data were obtained at each flexion angle using a 3-dimensional digitizer.

Results: Both ligament condition and valgus load had significant effects on contact area and pressure (P < .05). For a given load and flexion angle, the contact area decreased and the pressure increased with increasing medial ulnar collateral ligament insufficiency. Within these trends, statistical significance was found at 30° of elbow flexion for both area and pressure (P < .05); at 90° of elbow flexion, increasing medial ulnar collateral ligament insufficiency did not significantly affect contact area or pressure (P > .05).

Discussion: Medial ulnar collateral ligament insufficiency alters contact area and pressure between the posteromedial trochlea and olecranon and helps explain the development of posteromedial osteophytes.

Estrogen has been implicated as a causal factor for anterior cruciate ligament injuries in women. Studies have demonstrated a decrease in anterior cruciate ligament fibroblast proliferation and collagen synthesis at supraphysiologic levels of estrogen in a rabbit model.

Hypothesis: The authors hypothesized that physiologic levels of estrogen would have no significant effect on anterior cruciate ligament fibroblast proliferation and collagen synthesis in an ovine model.

Methods: Anterior cruciate ligament fibroblasts were isolated from sheep knees using routine cell culture methods. The cells were exposed to 17β-estradiol at physiologic concentrations of 2.2, 5, 15, 25, 250, and 2500 pg/ml. Cell proliferation was determined by cell counts on days 4 and 6. Collagen synthesis was determined by 3H-proline incorporation on day 4. Immunohistochemistry was performed to detect estrogen receptors.

Results: Immunohistochemistry demonstrated the presence of estrogen receptors in ovine anterior cruciate ligament fibroblasts. There was no significant difference in anterior cruciate ligament fibroblast proliferation or collagen synthesis regardless of 17β-estradiol concentration.

Conclusions: Based on results of this study, and given the low turnover of collagen in ligaments, it is unlikely that a 2- to 3-day per month increase in circulating estrogen would result in rapid, clinically significant alterations in material properties ofthe anterior cruciate ligament in vivo. The etiology of noncontact anterior cruciate ligament injuries is complex and multifactorial in nature, meriting further investigation.

Background: Bone morphogenetic proteins induce new bone both in patients with bone defects and at extraskeletal sites in animals. After anterior cruciate ligament rupture, tendon graft fixation into a bone tunnel is a widely used method for anterior cruciate ligament reconstruction.

Hypothesis: Bone morphogenetic protein–7 applied to the bone-tendon interface enables better integration of a free tendon graft into the surrounding bone.

Study Design: Controlled laboratory study.

Methods: The anterior cruciate ligament was reconstructed using a free tendon graft in the right rear knees of 30 one-year-old male sheep. Recombinant human bone morphogenetic protein–7 (25 μg) was applied randomly to the bone-tendon interface in 15 animals, and a vehicle was applied in 15 control animals. At 3 weeks, 10 animals from each group were sacrificed, and the remaining sheep were sacrificed at 6 weeks after surgery. Subsequently, histologic analysis and mechanical testing were performed. In another group of 20 sheep, the same procedure was used and mechanical testing was performed after 3 weeks.

Results: More new bone was formed at the bone-tendon interface in the knees treated with bone morphogenetic protein–7 as compared histologically with similar areas in control animals, creating areas of dense trabecular network with significantly greater invasion of the tendon fibrous tissue into the bone marrow space. Mechanical testing showed greater strain resistance to force (368 N) in the knees treated with bone morphogenetic protein–7 than in control specimens (214 N). There was no difference between mechanical testing of samples from 3 and 6 weeks after surgery.

Conclusion: Bone morphogenetic protein–7 promotes complete tendon graft integration into the newly formed surrounding trabecular bone in the reconstruction of the anterior cruciate ligament.

Clinical Relevance: Bone morphogenetic protein–7 in tendon graft integration might be successfully used in reconstructive surgery of ligaments.

Background: Numerous injuries have been attributed to playing on artificial turf. Recently, FieldTurf was developed to duplicate the playing characteristics of natural grass. No long-term study has been conducted comparing game-related, high school football injuries between the 2 playing surfaces.

Hypothesis: High school athletes would not experience any difference in the incidence, causes, and severity of game-related injuries between FieldTurf and natural grass.

Study Design: Prospective cohort study.

Methods: A total of 8 high schools were evaluated over 5 competitive seasons for injury incidence, injury category, time of injury, injury time loss, player position, injury mechanism, primary type of injury, grade and anatomical location of injury, type of tissue injured, head and knee trauma, and environmental factors.

Results: Findings per 10 team games indicated total injury incidence rates of 15.2 (95% confidence interval, 13.7-16.4) versus 13.9 (95% confidence interval, 11.9-15.6). Minor injury incidence rates of 12.1 (95% confidence interval, 10.5-13.6) versus 10.7 (95% confidence interval, 8.7-12.7), substantial injury incidence rates of 1.9 (95% confidence interval, 1.4-2.6) versus 1.3 (95% confidence interval, 0.8-2.1), and severe injury incidence rates of 1.1 (95% confidence interval, 0.7-1.7) versus 1.9 (95% confidence interval 1.2-2.8) were documented on FieldTurf versus natural grass, respectively. Multivariate analyses indicated significant playing surface effects by injury time loss, injury mechanism, anatomical location of injury, and type of tissue injured. Higher incidences of 0-day time loss injuries, noncontact injuries, surface/epidermal injuries, muscle-related trauma, and injuries during higher temperatures were reported on FieldTurf. Higher incidences of 1- to 2-day time loss injuries, 22+ days time loss injuries, head and neural trauma, and ligament injuries were reported on natural grass.

Conclusions: Although similarities existed between FieldTurf and natural grass over a 5-year period of competitive play, both surfaces also exhibited unique injury patterns that warrant further investigation.

Background: Evaluation of the knee after an anterior cruciate ligament reconstruction with the use of the semitendinosus and gracilis (hamstring) autografts has primarily focused on flexion and extension strength. The semitendinosus and gracilis muscles contribute to internal tibial rotation, and it has been suggested that harvest of these tendons for the purpose of an anterior cruciate ligament reconstruction contributes to internal tibial rotation weakness.

Hypothesis: Internal tibial rotation strength may be affected by the semitendinosus and gracilis harvest after anterior cruciate ligament reconstruction.

Study Design: Prospective evaluation of internal and external tibial rotation strength.

Methods: Inclusion criteria for subjects (N = 30): unilateral anterior cruciate ligament reconstruction at least 2 years previously, a stable anterior cruciate ligament (<5-mm side-to-side difference) at time of testing confirmed by surgeon and KT-1000 arthrometer, no history of knee problems after initial knee reconstruction, a normal contralateral knee, and the ability to comply with the testing protocol. In an attempt to minimize unwanted subtalar joint motion, subjects were immobilized using an ankle brace and tested at angular velocities of 60°/s, 120°/s, and 180°/s at a knee flexion angle of 90°.

Results: The mean peak torque measurements for internal rotation strength of the operative limb (60°/s, 17.4 ± 4.5 ft-lb; 120°/s, 13.9 ± 3.3 ft-lb; 180°/s, 11.6 ± 3.0 ft-lb) were statistically different compared to the nonoperated limb (60°/s, 20.5 ± 4.7 ft-lb; 120°/s, 15.9 ± 3.8 ft-lb; 180°/s, 13.4 ± 3.8 ft-lb) at 60°/s (P = .012), 120°/s (P = .036), and 180°/s (P = .045). The nonoperative limb demonstrated greater strength at all speeds. The mean torque measurements for external rotation were statistically similar when compared to the nonoperated limb at all angular velocities.

Conclusions: We have shown through our study that patients who undergo surgical intervention to repair a torn anterior cruciate ligament with the use of autogenous hamstring tendons demonstrate with weaker internal tibial rotation postoperatively at 2 years when compared to the contralateral limb.

Background: It is generally thought that tissue regeneration and good functional recovery can be expected after anterior cruciate ligament reconstruction using the hamstring tendons. However, persistent strength deficit in deep knee flexion has also been reported.

Hypothesis: Morphologic regeneration of the harvested hamstring tendon is not necessarily associated with its functional recovery.

Study Design: Retrospective follow-up study.

Method: Twenty-eight patients who underwent anterior cruciate ligament reconstruction with hamstring graft were evaluated after a minimum period of 2 years. Status of tendon regrowth was assessed by magnetic resonance imaging. To specifically analyze the functional deficit after graft harvest, the isometric hamstring strength was examined in a sitting position at 90° of flexion and a prone position at 90° and 110° of flexion. Then, the strength data were correlated with the extent of tendon regeneration.

Results: In 22 of the 28 patients, a regrowth of the semitendinosus tendon was found, whereas regeneration of the gracilis tendon was observed in 13 patients. In the evaluation of hamstring strength, the isometric peak torque was reduced to 86.2%, 54.6%, and 49.1%, respectively, in the aforementioned 3 postures as compared with the contralateral side.

Conclusions: Significant functional deficit of hamstring strength remains regardless of morphologic regeneration.

Background: Autograft stabilization uses free semitendinosus tendon grafts to anatomically reconstruct the anterior talofibular ligament. Study aims were to evaluate the biomechanical properties of Mitek GII anchors compared with the Arthrex Bio-Tenodesis Screw for free tendon reconstruction of the anterior talofibular ligament.

Null Hypothesis: There are no differences in load to failure and percentage specimen elongation at failure between the 2 methods.

Study Design: Controlled laboratory study using porcine models.

Methods: Sixty porcine tendon constructs were failure tested. Re-creating the pull of the anterior talofibular ligament, loads were applied at 70° to the bones. Thirty-six tendons were fixed to porcine tali and tested using a single pull to failure; 10 were secured with anchors and No. 2 Ethibond, 10 with anchors and Fiber Wire, 10 with screws and Fiberwire, and 6 with partially gripped screws. Cyclic preloading was conducted on 6 tendons fixed by anchors and on 6 tendons fixed by screws before failure testing. Two groups of 6 components fixed to the fibula were also tested.

Results: The talus single-pull anchor group produced a mean load of 114 N and elongation of 37% at failure. The talus single-pull screw group produced a mean load of 227 N and elongation of 22% at failure (P < .05). Cyclic preloading at 65% failure load before failure testing produced increases in load and decreases in elongation at failure. Partially gripped screws produced a load of 133 N and elongation of 30% at failure. The fibula model produced significant increases in load to failure for both. The human anterior talofibular ligament has loads of 139 N at failure with instability occurring at 20% elongation.

Conclusions: Interference screw fixation produced significantly greater failure strength and less elongation at failure than bone anchors.

Clinical Relevance: The improved biomechanics of interference screws suggests that these may be more suited to in vivo reconstruction of the anterior talofibular ligament than are bone anchors.

Background: Extracorporeal shock wave therapy is a relatively new therapy used in the treatment of chronic tendon-related pain. Few randomized controlled trials have been performed on it, and no studies have examined the effectiveness of extracorporeal shock wave therapy as a frontline therapy for tendon-related pain.

Hypothesis: Subjects treated with active extracorporeal shock wave therapy will have higher rates of treatment success than subjects treated with sham extracorporeal shock wave therapy.

Design: Double-blind randomized controlled trial.

Methods: Sixty subjects who had previously untreated lateral epicondylitis for less than 1 year and more than 3 weeks were included in this study. Subjects were randomly allocated to receive 1 session per week for 3 weeks of either sham or active extra-corporeal shock wave therapy. Subjects in the active therapy group received 2000 pulses (energy flux density, 0.03-0.17 mJ/mm2). All subjects were provided with a forearm-stretching program. After 8 weeks of therapy, subjects were classified as either treatment successes or treatment failures according to fulfillment of all 3 criteria: (1) at least a 50% reduction in the over-all pain visual analog scale score, (2) a maximum allowable overall pain visual analog scale score of 4.0 cm, and (3) no use of pain medication for elbow pain for 2 weeks before the 8 week follow-up. Visual analog scale scores were also collected for pain at rest, during sleep, during activity, at its worst, and at its least, as well as for quality of life (using the EuroQoL questionnaire) and grip strength.

Results: Success rates in the sham and active therapy groups were 31% and 39%, respectively. No significant difference was detected between groups (χ21 = 0.3880, P = .533). Mean change in quality of life over 8 weeks was an increase of 1.3 and 3.3 for sham and active therapy groups, respectively, and mean change in grip strength over 8 weeks was an increase of 7.4 kg and 6.8 kg for sham and active therapy groups, respectively.

Conclusions: Despite improvement in pain scores and pain-free maximum grip strength within groups, there does not appear to be a meaningful difference between treating lateral epicondylitis with extracorporeal shock wave therapy combined with forearm-stretching program and treating with forearm-stretching program alone, with respect to resolving pain within an 8-week period of commencing treatment.

Background: Hip arthroscopy has defined elusive causes of hip pain.

Hypothesis/Purpose: It is postulated that the reliability of various investigative methods is inconsistent. The purpose of this study is to evaluate the diagnostic accuracy of these methods.

Study Design: Retrospective review of prospectively collected data.

Methods: Five parameters were assessed in 40 patients: clinical assessment, high-resolution magnetic resonance imaging, magnetic resonance imaging with gadolinium arthrography, intra-articular bupivacaine injection, and arthroscopy. Using arthroscopy as the definitive diagnosis, the other parameters were evaluated for reliability.

Results: Hip abnormality was clinically suspected in all cases with 98% accuracy (1 false positive). However, the nature of the abnormality was identified in only 13 cases with 92% accuracy. Magnetic resonance imaging variously demonstrated direct or indirect evidence of abnormality but overall demonstrated a 42% false-negative and a 10% false-positive interpretation. Magnetic resonance arthrography demonstrated an 8% false-negative and 20% false-positive interpretation. Response to the intra-articular injection of anesthetic was 90% accurate (3 false-negative and 1 false-positive responses) for detecting the presence of intra-articular abnormality.

Conclusions: In this series, clinical assessment accurately determined the existence of intra-articular abnormality but was poor at defining its nature. Magnetic resonance arthrography was much more sensitive than magnetic resonance imaging at detecting various lesions but had twice as many false-positive interpretations. Response to an intra-articular injection of anesthetic was a 90% reliable indicator of intra-articular abnormality.

Background: The relationship between posterior cruciate ligament insufficiency and meniscal injury is unclear.

Hypothesis: Posterior cruciate ligament insufficiency results in increased medial and lateral meniscal strain.

Study Design: Descriptive anatomic study.

Methods: Eight cadaveric specimens were evaluated with a 6-axis load cell and differential variable reluctance transducer strain gauges placed in both menisci. Data were recorded in the posterior cruciate ligament–intact state after posterior cruciate ligament transection and after posterior cruciate ligament reconstruction.

Results: The effect of posterior cruciate ligament state on meniscal strain was more pronounced at higher flexion angles. At 60° and 90° of flexion, there was a significant effect of posterior cruciate ligament sectioning and reconstruction on meniscal strain (P < .026). Average meniscal strain for both medial and lateral menisci increased between the intact and the posterior cruciate ligament–cut states. Posterior cruciate ligament reconstruction decreased strain values to that of the intact knee.

Conclusions: Meniscal strain increases with complete posterior cruciate ligament injury and is returned to posterior cruciate ligament–intact levels after posterior cruciate ligament reconstruction.

Clinical Relevance: Posterior cruciate ligament reconstruction may play an important role in reducing meniscal strain and sub-sequent degeneration within the posterior cruciate ligament–injured knee.

Background: In patients suffering from an anterior cruciate ligament injury, the incidence and location of bone bruises are well documented. This study reports data regarding bone bruises after acute posterior cruciate ligament injury.

Hypothesis: Bone bruises associated with posterior cruciate ligament injury are common, and their location differs from those seen with anterior cruciate ligament injury.

Study Design: Retrospective cohort study.

Methods: Thirty-five consecutive patients were identified as having a grade II or III posterior cruciate ligament tear, with an intact anterior cruciate ligament, in which a magnetic resonance imaging scan had been obtained within 20 days of injury. Magnetic resonance imaging scans were reviewed to document bone bruises, associated medial or lateral ligamentous injury, and meniscal and chondral abnormalities.

Results: Of the 35 patients, 29 (83%) had a bone bruise in at least one location. Bone bruises were found throughout the joint, more widely dispersed than is commonly seen with anterior cruciate ligament injury. Also, 29 patients had magnetic resonance imaging findings of associated ligamentous injury. Lateral bone bruises were associated with medial collateral ligament injury, whereas medial bone bruises correlated with posterolateral injury.

Conclusions: The incidence of bone bruises associated with posterior cruciate ligament injury is similar to that seen with anterior cruciate ligament injury. Their location is more widely dispersed. The location of a bone bruise should lead to careful magnetic resonance imaging inspection and physical examination for ligamentous injury to the opposite side of the joint. Truly isolated posterior cruciate ligament injuries are rare, as most occur with osseous and some degree of associated ligamentous injury.

Background: In the past few years, competition climbing has grown in popularity, and younger people are being drawn to the sport.

Hypothesis: Although the radiographic changes in long-term climbers are known, there are little data available on young climbers. The question arises as to whether climbing at high levels at a young age leads to radiographic changes and possibly an early onset of osteoarthrosis in the finger joints.

Study Design: Cross-sectional study.

Methods: Nineteen members of the German Junior National Team and 18 recreational climbers were examined clinically and through radiographs. For comparison, radiographs of 12 young nonclimbers (control group) were collected. Radiographs were evaluated using a standard protocol. For evaluation of the physiologic adaptation, the cortical thickness of the middle phalanx and the Barnett Nordin index were analyzed. The results were compared between the 3 groups and against radiographs of 140 long-term, experienced climbers.

Results: Six climbers (32%) of the German Junior National Team presented a decreased range of motion for the small finger joints; none of the recreational climbers showed this decrease. In 47% of the German Junior National Team and 28% of the recreational climbers, stress reactions could be found: cortical hypertrophy (26% German Junior National Team, 11% recreational climbers), subchondral sclerosis (47% German Junior National Team, 6% recreational climbers), broadened base of the proximal interphalangeal joint (42% German Junior National Team, 28% recreational climbers), and broadened base of the distal interphalangeal joint (16% German Junior National Team, 0 recreational climbers). Signs of an early stage of osteoarthrosis were seen in 1 climber in each group. The control group showed no radiologic abnormalities. The Barnett Nordin index was 0.49 ± 0.05 in German Junior National Team, 0.49 ± 0.07 in recreational climbers, and 0.48 ± 0.08 in the control group. There was no statistically significant difference on the Barnett Nordin index between the groups (German Junior National Team/recreational climbers: P = .89; German Junior National Team/control group: P = .58; recreational climbers/control group: P = .55).

Conclusions: Intensive training and climbing lead to adaptive reactions; nevertheless, osteoarthrotic changes are rare.

Background: Little information is known about the forces seen on the main individual structures of the posterolateral knee to applied loads. This information is needed to determine which structures should be reconstructed and also the relative strengths needed for reconstruction grafts.

Purpose: To determine in vitro forces in the fibular collateral ligament, popliteofibular ligament, and popliteus tendon for various posterolateral knee loading conditions.

Study Design: Cadaveric study.

Results: The fibular collateral ligament was loaded in varus, internal rotation, and external rotation. The highest amount of force seen on the fibular collateral ligament was at 0° of knee flexion with external rotation, with the mean load response to external rotation significantly less at 90°. Fibular collateral ligament varus load response at 0°, 30°, and 60° was fairly constant, with a significant decrease at 90° compared to 30° of knee flexion. The popliteus tendon and popliteofibular ligament were loaded with an external rotation moment and were noted to have similar loading patterns. The mean load response on both the popliteus tendon and the popliteofibular ligament peaked at 60° of knee flexion. The mean popliteus tendon and popliteofibular ligament load response at 0° was significantly less than the mean load response at 30°, 60°, and 90° of knee flexion.

Conclusions: High relative loads were seen on the fibular collateral ligament with varus and external rotation and on the popliteus tendon and popliteofibular ligament, with external rotation. A reciprocal relationship of load sharing in external rotation depending on knee flexion angle was revealed that has not been previously reported. The force on the fibular collateral ligament with external rotation loads was higher than the load on the popliteus complex at lower flexion angles, with the popliteus complex having higher load sharing at 60° and 90° of knee flexion. These results provide a measure of the potential for failure of these structures with joint loading and guidelines for both graft strength requirements for surgical reconstructions and postoperative rehabilitation protocols.

Background: Reduction of the tibia relative to the femur with the knee in maximum extension is required to correctly position the tibial tunnel in the sagittal plane when using a guide that targets the intercondylar roof. The authors found no studies that determined (1) whether gravity reduces the tibia and (2) whether roof impingement is prevented without a roofplasty and without positioning the tibial tunnel too posteriorly.

Methods: The position of the tibia relative to the femur was measured from a lateral radiograph of the treated knee in maximum extension with and without the tibial guide and of the contralateral normal knee in extension in single-leg stance (control).

Results: The position of the tibia with and without the tibial guide was not different (P = .33, not significant) and was only 0.7 mm more posterior than the control knee (P = .0075). A roofplasty was not required, and the clearance was 2 mm or less.

Conclusion: Gravity reduces the tibia on the femur when using a guide that targets the intercondylar roof. The use of a tibial guide that targets the intercondylar roof prevents roof impingement without a roofplasty and without positioning the tibial tunnel too posteriorly.

Background: Objective data quantifying differences in glenohumeral range of motion in baseball pitchers versus position players are established. There is limited information objectively comparing glenohumeral laxity in this same population.

Hypothesis: Baseball pitchers have greater difference in side-to-side anteroposterior translation of their throwing shoulders compared with position players.

Study Design: Prospective cross-sectional study.

Methods: Cutaneous electromagnetic sensors quantified anteroposterior shoulder translation of college and professional baseball players. Range of motion was measured.

Results: Nineteen position players and 37 pitchers were studied. Pitchers had a significant increase in external rotation of the dominant arm as compared with the nondominant arm (P = .02); the difference was not significant in position players (P = .34). The mean range of motion for pitchers’ dominant arm was 110° external rotation to 68° internal rotation, and it was 100° external rotation to 85° internal rotation for position players (P = .278). The mean anteroposterior translation in pitchers’ dominant arm was 33.30 mm and 29.84 mm in the nondominant side (P = .0001). This difference was not present in position players (P = .88). One of 19 position players had a side-to-side shoulder translation difference greater than 3 mm, compared with 22 of 37 pitchers (P = .0001).

Conclusions: Pitchers have a greater amount of glenohumeral translation in the dominant arm. This difference is not seen in position players. These differences make the side-to-side comparison less useful in pitchers and should be considered when making therapeutic decisions.

Background: Open rotator cuff repairs have led to excellent clinical results; however, several studies have linked postoperative structural integrity to patient outcomes. The purpose of this study is to prospectively assess postoperative cuff integrity after open rotator cuff repair and assess its relationship to clinical outcome.

Hypothesis: Preoperative rotator cuff tear size and postoperative rotator cuff integrity are important factors in overall clinical outcomes.

Study Design: Prospective nonrandomized clinical outcomes study.

Methods: Forty-seven consecutive patients undergoing repair of full-thickness rotator cuff tears by a single surgeon were enrolled in this prospective study. A standardized evaluation was performed preoperatively and postoperatively at annual intervals. All patients underwent postoperative magnetic resonance imaging at least 1 year after surgery. Statistical evaluation was performed using paired and unpaired 2-tailed t tests for comparison.

Results: Thirty-two patients were available for evaluation. Overall, the patients experienced a significant (P < .05) improvement in their American Shoulder and Elbow Surgeons survey (40-85) and Constant (53-80) scores. The overall retear rate was 31%. Although patients with large tears preoperatively and retears postoperatively had lower overall outcomes scores, this was not significant.

Conclusion: These data support open rotator cuff repair as an effective technique that restores excellent shoulder function. The authors did not find postoperative cuff integrity to have a significant effect on outcomes when compared with those with an intact cuff. In fact, those with a retear still had a significant improvement in all clinical areas assessed, including strength.

Background: Press-fit fixation of patellar tendon–bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. For hamstring tendon grafts, no biomechanical data exist of a press-fit procedure.

Hypothesis: Press-fit femoral fixation of hamstring tendons is mechanically equivalent to press-fit patellar tendon–bone fixation.

Study Design: Controlled laboratory study.

Methods: Patellar and hamstring tendons of 30 human cadavers (age, 53.8 ± 18.0 years) were used. An outside-in press-fit fixation with a knot in the semitendinosus and gracilis tendons and an inside-out and outside-in fixation with the tendons wrapped around a bone block were compared with patellar tendon–bone press-fit fixation in 30 ovine femora. Constructs were cyclically strained and then loaded until failure. Maximum load to failure, stiffness, and elongation during failure testing and cyclical loading were investigated.

Results: The maximum load to failure was 561 ± 309 N for the patellar tendon, 599 ± 234 N for the semitendinosus/gracilis tendons knot construct, 678 ± 231 for the semitendinosus/gracilis tendons bone construct inserted outside in, and 339 ± 236 for the semitendinosus/gracilis tendons bone construct inserted inside out (inferior to the others; analysis of variance, Dunn test, P < .01). Stiffness of the constructs averaged 134 ± 32 N/mm for the patellar tendon, 124 ± 21 N/mm for the knot construct, 118 ± 27 N/mm for the outside-in fixation, and 117 ± 23 N/mm for inside-out fixation. Elongation during initial cyclical loading was 0.7 ± 0.6 mm for the patellar tendon, 1.6 ± 0.5 mm for the knot construct, 1.9 ± 1.2 mm for the outside-in fixation, and 1.9 ± 0.9 mm for the inside-out fixation (significantly larger for all semitendinosus/gracilis tendon techniques, P < .05).

Conclusions: Failure loads for the semitendinosus/gracilis tendons bone construct inserted outside in and the semitendinosus/gracilis tendons knot construct were within the confidence interval of the patellar tendon press-fit fixation. All semitendinosus/gracilis tendon graft techniques exhibited larger elongation during initial cyclical loading than the patellar tendon graft. There was no difference in stiffness between all techniques.

Clinical Relevance: Two of the 3 hamstring press-fit fixation techniques showed loads to failure similar to the patellar tendon fixation. Preconditioning of the constructs is critical. These results must be interpreted with care because of high standard deviations.

Background: The authors assessed a new instrument, the Rolimeter, for the measurement of anteroposterior translation in the knee; it was compared to the KT-1000 arthrometer.

Purpose: To determine if the Rolimeter offers a valid method for the measurement of anteroposterior translation that is as reproducible and reliable as the KT-1000 arthrometer.

Methods: Two of 3 observers examined 16 normal subjects (32 knees) and 36 patients (72 knees) with ligament ruptures twice, using both the Rolimeter and the KT-1000 arthrometers, 30 minutes apart. Total anteroposterior translation (manual maximal Lachman test) was recorded at 20° and 80° of knee flexion.

Results: On average, the Rolimeter measured approximately 1 mm less anteroposterior displacement than the KT-1000 arthrometer at manual maximum stress. Rolimeter measurements were more consistent than the KT-1000 measurements as measured by our observers. Specificity and sensitivity were equivalent between the Rolimeter and the KT-1000 arthrometer.

Conclusions: The Rolimeter is as reproducible and reliable as the KT-1000 arthrometer. It offers a valid method for the measurement of anteroposterior translation in the knee. Higher accuracy was obtained at 20° of flexion for the KT-1000 arthrometer and at 80° of flexion for the Rolimeter.

Background: Traditional nonsurgical treatment of Jones fractures has high rates of delayed union, nonunion, and refracture. Internal fixation has become the treatment of choice in athletes and active patients.

Purpose: The purpose of this study was (1) to review the short- and long-term clinical results of cannulated screw fixation of Jones fractures and (2) to perform a biomechanical evaluation of fatigue failure characteristics of several types of screws used in the fixation of Jones fractures.

Study Design: Retrospective case series and in vitro biomechanical study.

Methods: Ten male and 5 female patients with Jones fractures fixed with cannulated screws ranging from 4 mm to 6.5 mm in diameter were evaluated by chart review, review of radiographs, and telephone interview. Mean follow-up from surgery to phone survey was 34 months. Screws ranging in size from 2.7 mm to 7.3 mm, both cannulated and noncannulated, stainless steel and titanium, were tested in the laboratory by cyclic loading to 250 N up to a maximum of 200 000 cycles.

Results: Mean time to healing as shown on radiographs and by full activity after surgery were 7.3 and 7.9 weeks, respectively. All patients were able to return to their previous levels of activity. Screw fatigue data showed that the number of cycles to failure increased with increasing screw diameter. For 4-mm screws, mean number of cycles to failure was 4308 for cannulated titanium screws, 22 012 for cannulated stainless steel screws, and 44 523 for noncannulated stainless steel screws.

Conclusions: In our patients, cannulated screw fixation of Jones fractures was a procedure that was reliable, had low morbidity, and afforded athletes a quick return to activity.

Clinical Relevance: The laboratory study suggests that the largest screw possible should be used for surgical fixation of these fractures and that screws less than 4 mm in diameter should be used with caution.

Background: Cyclooxygenase-2 inhibitors inhibit bone repair.

Hypothesis: Cyclooxygenase inhibitors might also have a negative effect on early tendon repair, although a positive effect on late tendon repair previously has been shown.

Study Design: Controlled laboratory study.

Methods: Achilles tendon transection was performed on 80 rats. Sixty rats were given daily intramuscular injections of either parecoxib (6.4 mg/kg body weight) or saline for the first 5 days after surgery and sacrificed either at 8 or 14 days. The remaining 20 rats were given intramuscular parecoxib or saline injections from day 6 until sacrifice at 14 days.

Results: At 8 days, early parecoxib treatment caused a 27% decrease in force at failure (P = .007), a 25% decrease in maximum stress (P = .01), and a 31% decrease in energy uptake (P = .05). Stiffness and transverse area were not significantly affected. At 14 days, early parecoxib treatment caused a decrease in stiffness (P = .004). In contrast to early treatment, late parecoxib treatment caused a 16% decrease in cross-sectional area (P = .03) and a 29% increase in maximum stress (P = .04).

Conclusions: During early tendon repair, a cyclooxygenase-2 inhibitor had a detrimental effect. During remodelling, however, inflammation appears to have a negative influence, and cyclooxygenase-2 inhibitors might be of value.

Clinical Relevance: The results suggest that cyclooxygenase-2 inhibitors should be used with care in the early period after tendon injury.

Catastrophic cervical spine injuries can lead to devastating consequences for the collision athlete. Improved understanding of these injuries can lead to identification of risk factors, early diagnosis, and effective on-field management. This article is the second in a 2-part series. The first part, published in the June 2004 issue, reviewed the current concepts regarding the epidemiology, functional anatomy, and diagnostic considerations relevant to cervical spine trauma in collision sports. In this article, the principles of on-field emergency care of the spine-injured athlete are reviewed. The authors discuss the need for effective pre-event planning, on-field evaluation and management of cervical spine injuries, and the transition of care from the playing field to the emergency room. The protocol for equipment removal, when necessary, is also reviewed. An organized, rapid approach to the management of cervical spine–injured collision athletes can help to optimize the outcomes of these catastrophic injuries.

Current knowledge and treatment of posterior cruciate ligament injuries continue to lag behind that of anterior cruciate ligament injuries. This is the result of the relative infrequency of posterior cruciate ligament injuries and the lack of consensus with respect to its natural history, surgical indications, technique, and postoperative rehabilitation. Recent anatomical and biomechanical studies have improved our understanding of the posterior cruciate ligament in an attempt to reproduce its anatomy and function during reconstruction. The following is a comprehensive review on the evaluation and treatment of posterior cruciate ligament injuries with special focus on the current surgical techniques.