The role of magnetic resonance imaging in a Division I university sports medicine program.

OBJECTIVE: To prospectively document musculoskeletal magnetic resonance imaging (MRI) use and how it affects diagnosis, playing status, and treatment of Division I university athletes. We hypothesized that MRI often has little or no effect on the diagnosis or treatment plan. DESIGN: Cross-sectional study. SETTING: Division I university sports medicine program. PATIENTS: Division I university varsity athletes. INTERVENTIONS: Data were collected of musculoskeletal MRI use in varsity student athletes for 2 full academic years from 2010 to 2012 at a National Collegiate Athletic Association Division I institution. MAIN OUTCOME MEASURES: Timing of the injury, first physician visit, and MRI and pre- and post-MRI diagnosis, playing status, and treatment (surgical vs nonsurgical). RESULTS: Eighty-six MRIs were obtained during the 2 years studied. Average age was 19.9 (18-23) years. Forty-five percent of injuries occurred during competition season, 34% occurred preseason, and 21% occurred postseason. There was a change in diagnosis in 13 athletes (15.1%, 1 led to surgery performed after completion of the season), and there was a change in participation status in 8 athletes (9.3%, 5 increased and 3 decreased). Treatment plan changed in 1 athlete (1.2%). No athlete required surgery immediately after an MRI that was not already being planned. Every athlete treated nonsurgically pre-MRI was able to finish their season. CONCLUSIONS: Magnetic resonance imaging was obtained in 14% of athletes and did not demonstrate a clear benefit over history, examination, and radiographs. Magnetic resonance imaging did change diagnosis in 15% of cases, though it did not appreciably change the playing status or treatment plan.

Evaluation of the Schöttle Technique in the Pediatric Knee.

BACKGROUND: The Schöttle point is commonly used for anatomic femoral tunnel placement during medial patellofemoral ligament (MPFL) reconstruction. This technique has not been previously validated in the skeletally immature patient, in whom femoral tunnel placement may put the distal femoral physis at risk of iatrogenic injury. HYPOTHESIS: Interobserver reliability for femoral tunnel placement will be higher in adult knees compared with pediatric knees. STUDY DESIGN: Cross-sectional study (diagnosis); Level of evidence, 3. METHODS: We selected 30 perfect lateral radiographs for this study: 20 from pediatric knees (mean patient age, 10 years; range, 8-11 years) and 10 from adult knees (mean patient age, 18.5 years; range, 18-23 years). Six observers with varying levels of clinical experience evaluated each radiograph and approximated the site of the MPFL femoral tunnel using the Schöttle technique. Intra- and interobserver reliabilities for femoral tunnel placement were evaluated. Statistical analysis was used to compare measurements. RESULTS: During initial interobserver measurements, the diameter of the composite perfect circles averaged 9.0 and 6.8 mm in adult and pediatric knees, respectively (P = .004). At repeat measurement, circles averaged 9.8 and 7.3 mm in adult and pediatric knees, respectively (P = .0001). Femoral tunnel placement intraobserver variance averaged 2.9 mm in adult knees (range, 1.9-4.0 mm) and 2.3 mm in pediatric knees (range, 1.9-2.9 mm). This difference was not significant (P = .14). CONCLUSION: This study demonstrated that interobserver variance is actually greater in adult knees compared with pediatric knees, although interobserver variance was significantly different for both populations. Additionally, intraobserver variance is small on repeat measures, demonstrating that the Schöttle technique is reproducible for individual observers. Sources of this increased variance between observers are differences in agreement on the bony landmarks required for the Schöttle technique. Due to this variability in tunnel placement, we recommend caution when the Schöttle technique is used in pediatric knees to avoid iatrogenic injury to the distal femoral physis during femoral tunnel placement.

A Simple Radiographic Sign of Vertical Anterior Cruciate Ligament Tunnel Placement.

The purpose of this study is to describe a novel radiographic sign indicative of vertical tunnel placement following anterior cruciate ligament (ACL) reconstruction. We reviewed 190 consecutive ACL reconstructions. Operative records, patient charts, arthroscopic images, and preoperative and postoperative orthogonal plain radiographic images were reviewed. We made special note of the operative technique. Note was made of tunnel position and whether the posterior (proximal) aspect of Blumensaat line was violated on standard lateral knee radiographic images. Of 190 patients, 17 patients did not have postoperative imaging and were excluded. Of the 173 remaining knees, 163 were primary ACL reconstructions and 10 were revision ACL reconstructions. We found that no anatomically placed ACL femoral tunnel violated Blumensaat line. In all revision cases exhibiting violation of Blumensaat line, a new femoral tunnel was able to be drilled while completely avoiding the previously placed, nonanatomic ACL femoral tunnel. The principal findings of our study demonstrate that violation of Blumensaat line following ACL reconstruction is an indicator of vertical, nonanatomic femoral tunnel placement. Furthermore, presence of this radiographic sign indicates that an anatomically placed femoral tunnel may be drilled while completely avoiding the existing femoral tunnel during cases of revision ACL reconstruction.

Quadriceps and hamstrings muscle control in athletic males and females.

The aim of this study was to investigate whether athletic males and females have differences in their quadriceps and hamstrings muscle control strategies. Twenty-four people (12 males, 12 females) active in level I activities volunteered to participate. The subjects' muscle control strategies were studied using electromyography and a target matching protocol that assesses one's ability to produce force with control. The degree of control exhibited in the subjects' quadriceps and hamstrings muscle activation strategies was evaluated by calculating specificity indices for each muscle using circular statistics. Females displayed significantly lower specificity than males in their vastus medialis (p < 0.001), rectus femoris (p = 0.044), and lateral hamstrings (p = 0.001) muscle activity patterns, but similar specificity in their vastus lateralis and medial hamstrings activity patterns. Females also used a significantly higher magnitude of vastus lateralis (p < 0.001) and vastus medialis (p < 0.001) muscle activity than males to achieve the same relative force level. These findings indicate athletic males and females have differences in their knee muscle control strategies.