Orthopedics

Bishop, M. E., S. R. Black, J. Nguyen, D. Mintz and B. S. Stein (2019). “A Simple Method of Measuring the Distance From the Schottle Point to the Medial Distal Femoral Physis With MRI.” Orthop J Sports Med 7(4): eCollection.

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Background: Medial patellofemoral ligament (MPFL) reconstruction is the treatment of choice for recurrent patellar instability in the skeletally immature patient. Avoiding the open physes during anatomic MPFL reconstruction is a challenge in this population. Purpose: To describe a novel method using magnetic resonance imaging (MRI) to determine the distance from the Schottle point to the medial distal femoral physis among skeletally immature individuals with patellar instability. Study Design: Descriptive laboratory study. Methods: Preoperative MRI scans were analyzed from 34 patients with open distal femoral physes and lateral patellar instability. With the multiplanar reconstruction mode on a picture archiving and communication system (PACS), the location of the Schottle point was determined according to previously reported distances from the posterior femoral cortical line and the posterior origin of the medial femoral condyle. This location was then extrapolated to the most medial sagittal slice on MRI showing the medial distal femoral physis. The distance was measured from this point to the most distal aspect of the physis. Results: The mean age of the study cohort was 13.6 years (range, 10.6-15.7 years); there were 13 males and 21 females. The mean distance from the medial distal femoral physis to the Schottle point was 7.27 +/- 1.78 mm. The Schottle point was distal to the medial distal femoral physis in all cases. There was no significant correlation between age and mean distance in either the overall study population (r = 0.046, P = .798) or when stratified by sex (females, P = .629; males, P = .089). The distance between the Schottle point and the medial distal femoral physis was shorter for females than for males (6.51 vs 7.71 mm, P = .043). After adjustment for age, females on average were 1.31 mm closer to the Schottle point than were males (B = -1.31, P = .041). Conclusion: This technique can be used to determine the distance between the medial distal femoral physis and the Schottle point. The Schottle point was distal to the physis in all patients, and it was closer to the physis in skeletally immature females compared with age-matched males. Clinical Relevance: The long-term repercussions of improperly placed MPFL reconstruction include recurrent patellar instability, increased patellofemoral contact pressures and overtensioning of the ligament, and possibly patellofemoral arthritis. The current technique can be used preoperatively to determine the appropriate safe distance for drilling a socket distal to the physis.

Cordasco, F. A., S. R. Black, M. Price, C. Wixted, M. Heller, L. A. Asaro, J. Nguyen and D. W. Green (2019). “Return to Sport and Reoperation Rates in Patients Under the Age of 20 After Primary Anterior Cruciate Ligament Reconstruction: Risk Profile Comparing 3 Patient Groups Predicated Upon Skeletal Age.” Am J Sports Med 47(3): 628-639.

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BACKGROUND: With sports specialization and level of competition on the rise, anterior cruciate ligament reconstruction (ACLR) in athletes under the age of 20 has increased significantly in recent years. Reports have demonstrated that the revision ACLR rate is higher and return to sport (RTS) rate is lower in this population. PURPOSE: To evaluate the 2-year clinical outcomes of 3 cohorts of primary ACLR in pediatric and adolescent athletes under the age of 20 based on skeletal age with a focus on RTS and the incidence of second surgery. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This is a prospective evaluation of 324 athletes younger than 20 years of age who underwent ACLR with minimum 2-year follow-up. The surgical technique was selected predicated on skeletal age, which includes the all-epiphyseal technique with hamstring autograft in the youngest cohort in elementary and middle school (group 1), the partial transphyseal and complete transphyseal with hamstring autograft performed for athletes in the middle cohort (group 2), and bone-tendon-bone autograft in the skeletally mature high school athletes (group 3). RESULTS: The mean chronological age of the entire cohort was 15 years (range, 8-19 years) with 55% males. The 3 cohorts included 49 patients (15%) in group 1 (mean age, 12 years), 66 (20%) in group 2 (mean age, 14.3 years), and 209 (65%) in group 3 (mean age, 16.2 years). Group 2 athletes had a significantly higher revision ACLR rate (20%) compared with group 1 (6%; P = .039) and group 3 (6%; P = .001). Similarly, group 2 athletes had significantly lower RTS rates (85%) compared with group 1 (100%) and group 3 (94%). CONCLUSION: The rate of revision ACLR was significantly higher and the RTS rates significantly lower in group 2 compared with groups 1 and 3. This age-related risk profile may be used to counsel athletes and parents preoperatively regarding the expectations of surgery with respect to revision ACLR and RTS rates.

Mont, M. A., W. B. Beaver, S. H. Dysart, J. W. Barrington and D. J. Del Gaizo (2019). “Corrigendum to “Local Infiltration Analgesia With Liposomal Bupivacaine Improves Pain Scores and Reduces Opioid Use After Total Knee Arthroplasty: Results of a Randomized Controlled Trial” [Journal of Arthroplasty 33 (2018) 90-96].” J Arthroplasty 34(2): 399-400.

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The authors would like to inform the readership that during recent discussions with the US Food and Drug Administration (FDA) related to the registration trials for the label expansion of liposomal bupivacaine (LB; EXPAREL®, bupivacaine liposome injectable suspension; Pacira Pharmaceuticals, Inc., Parsippany, NJ), opioid conversion factors used in the statistical analyses were updated to reflect current knowledge of their relative potencies used in medical practice. The updates were approved by the FDA, as there is no current standard for opioid conversions. To maintain consistency with the FDA registration trials and the trials that will be registered with the European Medicines Agency (EMA; the European equivalent of the FDA), the conversion factors used in the PILLAR study were also updated. In place of intravenous morphine equivalent dose (MED), opioid consumption has been converted to oral MED using an updated set of conversion factors. These updates do not alter the original study conclusions. The changes affected both study arms equally and did not alter the findings or conclusions. (Excerpt from this correction, p. 399, to the study referenced in the title.)E

Cordasco, F. A., S. R. Black, M. Price, C. Wixted, M. Heller, L. A. Asaro, J. Nguyen and D. W. Green (2019). “Return to Sport and Reoperation Rates in Patients Under the Age of 20 After Primary Anterior Cruciate Ligament Reconstruction: Risk Profile Comparing 3 Patient Groups Predicated Upon Skeletal Age.” Am J Sports Med Jan 15. [Epub ahead of print].

Full text of this article.

BACKGROUND: With sports specialization and level of competition on the rise, anterior cruciate ligament reconstruction (ACLR) in athletes under the age of 20 has increased significantly in recent years. Reports have demonstrated that the revision ACLR rate is higher and return to sport (RTS) rate is lower in this population. PURPOSE:: To evaluate the 2-year clinical outcomes of 3 cohorts of primary ACLR in pediatric and adolescent athletes under the age of 20 based on skeletal age with a focus on RTS and the incidence of second surgery. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This is a prospective evaluation of 324 athletes younger than 20 years of age who underwent ACLR with minimum 2-year follow-up. The surgical technique was selected predicated on skeletal age, which includes the all-epiphyseal technique with hamstring autograft in the youngest cohort in elementary and middle school (group 1), the partial transphyseal and complete transphyseal with hamstring autograft performed for athletes in the middle cohort (group 2), and bone-tendon-bone autograft in the skeletally mature high school athletes (group 3). RESULTS: The mean chronological age of the entire cohort was 15 years (range, 8-19 years) with 55% males. The 3 cohorts included 49 patients (15%) in group 1 (mean age, 12 years), 66 (20%) in group 2 (mean age, 14.3 years), and 209 (65%) in group 3 (mean age, 16.2 years). Group 2 athletes had a significantly higher revision ACLR rate (20%) compared with group 1 (6%; P = .039) and group 3 (6%; P = .001). Similarly, group 2 athletes had significantly lower RTS rates (85%) compared with group 1 (100%) and group 3 (94%). CONCLUSION:: The rate of revision ACLR was significantly higher and the RTS rates significantly lower in group 2 compared with groups 1 and 3. This age-related risk profile may be used to counsel athletes and parents preoperatively regarding the expectations of surgery with respect to revision ACLR and RTS rates.

Kraeutler, M. J., K. V. Patel, A. Hosseini, G. Li, T. J. Gill and J. T. Bravman (2018). “Variability in the Clock Face View Description of Femoral Tunnel Placement in ACL Reconstruction Using MRI-Based Bony Models.” J Knee Surg 31(10): 965-969.

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Though controversial, the “clock face view” of the intercondylar notch remains a way some surgeons communicate regarding placement of the femoral tunnel in anterior cruciate ligament reconstruction. The purpose of this study was to quantify the differences in angle measurement between several previous descriptions of the clock face view by using a new reference standard. Three-Tesla magnetic resonance imaging (MRI) was used to scan 10 human knees to create three-dimensional MRI-based bony models which were used for measurements. A standardized clock face view was developed with the knee flexed to 90 degrees using the junction of the cartilage and cortex of the medial and lateral surfaces of medial and lateral femoral condyles as the 3 o’clock and 9 o’clock, respectively, with the 12 o’clock established as the midpoint of the roof of the intercondylar notch. With the knee viewed at 90 degrees of flexion, an “idealized” femoral tunnel position was plotted on the medial wall of the lateral femoral condyle at 30 degrees (corresponding to the 10 o’clock or 2 o’clock position). The clock faces as described by Edwards et al, Heming et al, and Mochizuki et al were each then overlaid on this same model and the difference in measurement calculated. The average angles measured when the previously described clock faces were projected onto the idealized clock face view comparing a mark made at 30 degrees were 47.7 degrees , 7.2 degrees , and 49.8 degrees for the methods described by Edwards et al, Heming et al, and Mochizuki et al, respectively (all p < 0.001). Significant variation exists between angle measurements in simulated femoral tunnel placement based on the varying descriptions of the intercondylar clock face.