No Difference in Pullout Strength Between a Bio-inductive Implant and a Semitendinosus Tendon Graft in a Biomechanical Study of Medial Patellofemoral Ligament Repair Augmentation.

Purpose: To compare the pullout strength of a bio-inductive implant (BI) used to augment a medial patellofemoral ligament (MPFL) repair with the pullout strength of semitendinosus graft in a biomechanical cadaveric model. Methods: Six matched pairs of cadavers (12 knees) were used in the biomechanical testing comparing semitendinosus tendon (Semi-T) versus a BI. The Semi-T was harvested from 1 of the matched pairs. A standard double-bundle technique using 2 sockets in the upper two-thirds of the patella 15 mm apart was performed. After docking of the graft into the patella, the patella was dissected free of soft tissues and potted into a fixture to allow mechanical pull parallel to the transverse axis of the patella. The construct was pulled to failure. Results: There was no statistically significant difference in pullout strength (P = .77) between the BI group (249.3 ± 36.3 N) and Semi-T group (235.0 ± 113.6 N) double-bundle constructs. In the Semi-T group, 50% of the specimens (3 of 6 knees) failed via anchor pullout and a fourth specimen failed at the suture-anchor interface (16.7%), whereas in the BI group, 16.7% of the specimens (1 of 6 knees) failed by anchor pullout. Although the Semi-T group (49.5 ± 14.1 N/mm) showed significantly greater stiffness than the BI group (13.8 ± 0.6 N/mm, P < .01), pullout strength in the Semi-T group was highly variable: 50% of the specimens (3 of 6 knees) with semitendinosus constructs failed at 5 mm of displacement or less via graft or anchor pullout. Maximum load, displacement at failure, stiffness, and load at 5 mm were compared between the augmented and non-augmented control specimens using a 2-tailed non-equal variance Student t test. For all comparisons, P < .05 was considered to indicate a statistically significant difference. Conclusions: In this biomechanical study, augmentation of an MPFL reconstruction using a common double-bundle technique with a BI had the same pullout strength as a semitendinosus graft using the same technique in cadaveric knees. Clinical Relevance: MPFL repair after a patellar dislocation may be inadequate to restore the strength of the native MPFL and prevent recurrent patellar instability. Recurrent instability of the patella can result in progressive injury to the soft tissue and articular cartilage of the patella and femur. It is important to study the techniques used for MPFL repair to continually improve patient outcomes. Further testing of these additional techniques and clinical studies are needed to evaluate the implants used to augment MPFL repairs.

Editorial Commentary: Tissue-Engineered Meniscal Scaffolds and Implants Show Promising Short-Term Outcomes While Long-Term Comparison With Meniscal Allograft Transplantation Is Pending.

Because of the prevalence of meniscal injuries and the difficulty treating irreparable tears and large defects, there has been increasing research and resultant engineering strategies over the past 20 years that have resulted in development of various meniscal scaffolds and meniscal implants. At this time, meniscal allograft transplant may be the "standard" consideration for the nonarthritis, meniscal deficient, stable, and properly aligned painful knee, but challenges include availability, preoperative planning and sizing, costs, and logistics. Newer tissue-engineered implants can minimize these concerns, and recent systematic review shows these may provide short-term improvement in knee pain and function. However, studies demonstrating long-term improvements remain pending, and it is unclear whether these implants will result in outcomes better than meniscal allograft transplant.

Editorial Commentary: Good Start But More Testing Needs to Be Done: Load to Failure and Knot Security Comparing Suture Tape Versus High-Strength Suture.

Two-millimeter high tensile strength tape (HTST) ultimate load to failure and knot security is greater than No. 2 high tensile strength suture. However, not many surgeons tie knots with 2-mm HTST. More testing needs to be done with 1.3- and 1.7-mm HTST.

Injuries in the Chinese Arena Football League: American Versus Chinese Players.

BACKGROUND: Arena football is an indoor version of American football played in indoor arenas on a smaller field with 8 players per team. Only 1 study has evaluated injury rates in arena football, and no study had compared 2 distinct cohorts of players. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate and compare injury rates in American versus Chinese athletes in the Chinese Arena Football League. Our hypothesis was that the rate of significant injuries (≥7 days of time lost from play) would be statistically significantly higher in Chinese athletes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Each of the 6 teams included in this study comprised 11 American and 11 Chinese athletes, for a total of 132 included athletes (66 Chinese, 66 American). All players stayed in the same hotel, trained and played in the same facilities, and were covered by the same medical staff. A total of 18 games were played consecutively in 6 cities from October 1 to November 6, 2016. At least 4 Chinese players had to be on the field for each team at all times during game play. RESULTS: American athletes were significantly older, taller, and heavier than Chinese athletes. The total exposure was 759 athlete-hours, and there were 80 reported injuries, with 74 (92.5%) occurring during games (overall injury rate, 105.4 injuries per 1000 athlete-hours). For American athletes, the exposure was 387 athlete-hours with 38 injuries observed, and the injury rate was 98.2 injuries per 1000 athlete-hours. For Chinese athletes, the exposure was 372 athlete-hours with 42 injuries observed, and the injury rate was 112.9 injuries per 1000 athlete-hours. There was no statistically significant difference in exposure or overall injury rate between American and Chinese athletes. The rate of significant injuries was 30.3 per 1000 athlete-hours; there were 17 such injuries in Chinese athletes compared with 6 such injuries for American athletes. The rate of significant injuries was 45.7 (Chinese) and 15.5 (American) injuries per 1000 athlete-hours, and the relative risk for Chinese versus American athletes for significant injuries was 3.0 (95% CI, 1.2-7.8; P = .019) . Binary logistic regression models were utilized to analyze whether the baseline variables (height, weight, body mass index, age, years of experience, and nationality) were potential predictors for an injury, and only years of experience (odds ratio, 1.147 [95% CI, 1.034-1.271]; P = .009) was found to be associated with severe injuries (>21 days of time loss). CONCLUSION: The overall risk of injuries was similar between Chinese and American athletes, but Chinese athletes showed statistically higher rates of significant injuries than their American counterparts. Years of experience was the only factor that was associated with severe injuries. As professional sports become more global, medical personnel must take into account the distinct differences and levels of experience between the national and international professional athletes. The results of this study will be used to make recommendations to develop preventive training measures, including techniques to improve tackling.

Editorial Commentary: Is the Cure Worse Than the Disease? Harvesting Autologous Osteochondral Transfer Plugs for Treatment of Lesions of the Elbow.

For autologous osteochondral transfer procedures for osteochondritis dessicans of the elbow, surgeons usually use the knee or ribs as donor sites. This procedure is not without donor site complications. Finding local donor sites is important to reducing the overall morbidity of this procedure.

Editorial Commentary: Don't Forgot the Hip in Swimmers and Multisport Athletes.

Swimming results in significant and repetitive stress on the hip as well as other joints, and hip pain in swimmers should not be ignored. Stretching and strengthening are the mainstays of injury prevention, and recent literature supports that when indicated, femoroacetabular impingement surgical treatment in swimmers results in excellent outcomes including return to sport and frequently at a level of performance superior to pre-injury status.

Related Research and Arthroscopy: Increasing the Breadth of Arthroscopy and Arthroscopy Techniques.

An editorial goal is to increase the breadth of Arthroscopy and Arthroscopy Techniques. Our readers are more than arthroscopic surgeons and scientists. Rather, the health care providers and scientists who read our journals are, first and foremost, physicians, allied health practitioners, and academic intellectuals whose interests include improving individual and public health and welfare across a wide spectrum of scholarly topics. By reaching a broader audience, we hope to expand our contribution to arthroscopic and related surgery and continue to develop the potential of our subspecialty.

Editorial Commentary: Is the Information Gathered From Patient-Reported Outcome Worth the Time and Effort? Electronic Patient-Reported Outcome Data Collection Systems Result in Poor Response Rate.

There is an increasing demand for quality metrics and patient-reported outcomes from government agencies and insurance carriers. However, electronic patient-reported outcomes fail to achieve a significant response rate because they are too long and complicated. It is suggested that outcome scores for quality metrics need to be simplified to increase the response rate.

Editorial Commentary: When a Tie Is Still a Win: Systematic Reviews Showing No Difference Between Treatments May Not Be Generalizable to Individual Patients.

When a systematic review finds no difference between treatment options for a particular disorder, this could mean more than you think. Individual patients requiring shoulder Bankart repair are unique with respect to their demands and expectations and pathology. Surgeons should combine published principles with understanding of their own skills and their specific patient to optimize a treatment outcome.

Research Pearls: The Significance of Statistics and Perils of Pooling. Part 2: Predictive Modeling.

The focus of predictive modeling or predictive analytics is to use statistical techniques to predict outcomes and/or the results of an intervention or observation for patients that are conditional on a specific set of measurements taken on the patients prior to the outcomes occurring. Statistical methods to estimate these models include using such techniques as Bayesian methods; data mining methods, such as machine learning; and classical statistical models of regression such as logistic (for binary outcomes), linear (for continuous outcomes), and survival (Cox proportional hazards) for time-to-event outcomes. A Bayesian approach incorporates a prior estimate that the outcome of interest is true, which is made prior to data collection, and then this prior probability is updated to reflect the information provided by the data. In principle, data mining uses specific algorithms to identify patterns in data sets and allows a researcher to make predictions about outcomes. Regression models describe the relations between 2 or more variables where the primary difference among methods concerns the form of the outcome variable, whether it is measured as a binary variable (i.e., success/failure), continuous measure (i.e., pain score at 6 months postop), or time to event (i.e., time to surgical revision). The outcome variable is the variable of interest, and the predictor variable(s) are used to predict outcomes. The predictor variable is also referred to as the independent variable and is assumed to be something the researcher can modify in order to see its impact on the outcome (i.e., using one of several possible surgical approaches). Survival analysis investigates the time until an event occurs. This can be an event such as failure of a medical device or death. It allows the inclusion of censored data, meaning that not all patients need to have the event (i.e., die) prior to the study's completion.

Editorial Commentary: Belt and Suspenders-Linked Single-Row Rotator Cuff Repair.

Rotator cuff repairs fail at the suture-soft tissue interface. The linked single-row repair technique may provide increased soft tissue pullout strength, but further study is needed.

Editorial Commentary: No 2 Hips Are the Same-Femoroacetabular Impingement May Be More Proximal in Patients With Developmental Dysplasia.

Every hip is unique. The area of cam impingement is more proximal in patients with borderline developmental dysplasia of the hip. It is important to recognize this to ensure successful treatment.

Editorial Commentary: Google It!-Reliability of Medical Information Found on the Internet.

Patients use Google or other search engines to obtain information on various medical problems. This information is not always reliable, and physicians should direct patients to Web sites that are validated and reliable.

Editorial Commentary: Pitching Should Come With a Warning Label.

Pitching is not without risk of overuse injuries. Pitch counts have been instituted to reduce the risk, but Riff et al.'s article clearly demonstrates that as pitchers get older they do not adhere to these counts, which increases the risk of injury.

Editorial Commentary: Many Ways to Skin a Cat.

There are many ways to treat lateral epicondylitis. The authors of this study present 2 different methods, but one method has less operative cost and takes less time. As medicine evolves, we should take this into account when choosing one procedure over another.

Editorial Commentary: Risks Versus Benefits.

As orthopaedic surgeons, we are constantly weighing the risks versus benefits of the procedures we may perform in our patients. The study by Werner et al. can be used to better inform our patients of the risk of undergoing arthroscopy of the elbow, allowing the orthopaedic surgeon to better weigh the risks versus benefits of the procedure.

Editorial Commentary: Think Twice, Cut Once.

How much of the anterior acetabulum rim needs to be resected to reduce the impingement of the pincer lesion? Hellman et al. present 3 measurements that can be performed on routine radiographs so that the surgeon can preoperatively, intraoperatively, and postoperatively measure the amount resected from the anterior acetabulum rim.

Editorial Commentary: Reinventing the Anterior Cruciate Ligament.

Our goal as orthopaedic surgeons is to repair, reconstruct, and/or restore function and anatomy to our patients. A new study in this issue, commented upon here, represents another step toward helping surgeons recreate the anatomy of the native anterior cruciate ligament.

Editorial Commentary: Doc, Can You Inject Stem Cells in My Knee?

Stem cell therapy is one of the most promising treatments to restore and repair damaged articulate cartilage. Koh et al. present in this issue their study on the treatment of articulate cartilage defects with adipose derived stem cell. We believe that it is a matter of time to when stem cells will become cost effective and commercially available for the treatment of articulate cartilage injuries.