The return-to-sport rate from this study is similar to others seen in the literature in that 92.1% of baseball pitchers returned to the same or higher level of function. An interesting finding of this study was the breakdown in athletic level of patients who underwent UCLR. The majority of patients in this study were collegiate (51.6%) and high school (36.2%) athletes. Although this procedure has been common in collegiate athletes for some time, the number of high school athletes undergoing UCLR is somewhat concerning. There has been a trend in the literature toward younger patients undergoing UCLR, with a recent increase in the percentage of high school athletes compared with other levels. A recent study on national trends in UCLR between 2007 and 2011 using the Pearl Diver database showed that UCLR was most commonly performed in 15- to 19-year-old patients; 57% of all patients undergoing UCLR fell into this age group. Although injury prevention programs have been instituted over the past decade to protect adolescent athletes from injury, these programs have yet to yield a significant decline in injury rates. Interestingly, this study did not show a significant difference in the yearly timing of UCLR. One could postulate that pitchers are at greater risk for injuries during the beginning of the season, as they have not yet returned to game shape, but this does not appear to be accurate based on this study. The implications of this finding are that preventative programs aimed at reducing injuries at the beginning of the season may not be effective given the relatively even distribution of yearly UCLR timing seen in this study. Further research into injury prevention is crucial to slow the increase in UCLR, specifically in the high school athlete population.
There is a relative paucity of literature regarding the use of allograft in UCLR. Savoie et al reported the largest series of allograft UCLR in which 116 patients (a mixture of high school, college, and professional athletes involved in baseball, softball, and javelin) underwent UCLR with hamstring allograft and found that 94.8% of players had returned to play, 88% of whom returned to play at an equal or higher level. Allograft alleviates the issue of donor site morbidity but introduces foreign human tissue into the young athlete's elbow, and there may be substantial variability in the quality of the allograft tissue. Allografts are expensive, but the overall cost related to the procedure may be offset by avoiding autograft harvest and wound closure. The results of our study are consistent with the prior study and suggest that allograft UCLR is a reasonable option for surgeons after appropriate patient and family consent. 
While graft choice is an important aspect of UCLR, treatment of the ulnar nerve is also important and has become controversial. Some authors recommend routine anterior subcutaneous transposition while others do not transpose the nerve at all. All the authors in this study treated the ulnar nerve with the same philosophy of management. If the patient had preoperative ulnar nerve symptoms such as paresthesia in the small and ring fingers, wasting of the interossi muscles of the hand, a positive Tinel sign at the elbow, or subluxation of the nerve, an anterior subcutaneous ulnar nerve transposition was performed as part of the index procedure. However, if the patient did not have any of the above preoperative symptoms, the ulnar nerve was not formally transposed but rather simply identified for protection and decompressed in situ. Of the 188 elbows in this study, 7 (3.7%) underwent subsequent ulnar nerve transposition for persistent ulnar nerve symptoms during the routine follow-up period. Vitale and Ahmad reviewed the literature on UCLR and found postoperative ulnar neuropathy in 3% to 8% of patients depending on the technique used (excluding the Jobe technique, which had a 20% rate of postoperative ulnar neuropathy after submuscular transposition). Hence, to date, there is no literature to strongly support any 1 practice over another, and as such, recommendations on how best to treat the ulnar nerve cannot be made at this time. In our study, the ulnar nerve was transposed subcutaneously in 79 (41.8%) patients, with an additional 7 (3.7%) requiring subsequent ulnar nerve transposition. Theoretically, if all patients underwent systematic ulnar nerve transposition, more than 50% of our patients would have been unnecessarily exposed to the potential added complications and adverse events associated with the subcutaneous ulnar nerve transposition.
The 1 patient in this series who required a revision UCLR was initially treated as a high school pitcher via the standard docking technique with a hamstring autograft and subcutaneous ulnar nerve transposition. He retore his UCL 4 months after surgery while in college and underwent a subsequent revision UCLR via the standard docking technique utilizing a palmaris longus allograft. As this was the only patient in this series to require a revision UCLR, it is difficult to determine whether there are any risk factors for retearing a UCL after UCLR. Other studies have shown that risk factors for sustaining an initial UCL tear include growing up in warm weather climates and pitching while fatigued (including pitching for multiple teams at a time, pitching more than 100 innings per season, pitching more than 9 months of the year, etc). Interestingly, throwing breaking pitches at early ages has not been shown to correlate with UCL injuries, which is a common misconception among athletes, parents, and coaches. 
The patients in this study did not routinely undergo elbow arthroscopy at the time of UCLR unless there was documented or suspected intra-articular pathology. This is in contrast to some studies in which patients routinely undergo elbow arthroscopy at the time of UCLR to confirm instability at the medial elbow and address any intra-articular pathology. The authors believe that, while some patients necessitate an arthroscopic evaluation and treatment for various intra-articular pathologies including osteochondritis dissecans and/or posteromedial osteophytes, the vast majority of patients do not need an arthroscopic evaluation. Using the combination of history (overhead athletes with medial elbow pain), physical examination (positive moving valgus stress test or milking maneuver), and diagnostic imaging (MRI or MRA), the authors feel comfortable diagnosing and treating UCL tears and associated pathology through a direct open approach without arthroscopy in the vast majority of patients.
Although this study was the largest cohort of double-docking UCLR and second largest overall cohort of UCLR patients reported in the literature to date for the patient demographics, there are several limitations. First, the patients did not have preoperative clinical scores to compare with postoperative scores. The surgical data were extracted from the electronic medical record, which may have been incomplete. There were patients who were unable to be contacted, and this could have affected the results, specifically falsely lowering the rate of postoperative ulnar neuropathy or falsely elevating the rate of return to sport. Furthermore, the study is subject to recording and recall bias as patients may not have recalled their complications or their complications may not be recorded in the electronic medical record. Similarly, they may have reported better results to the lead author (B.J.E.) on the phone in comparison with them completing a questionnaire. Patient physical examinations were not performed, so range of motion, strength, and valgus stress of the elbow were unable to be assessed, and performance measures were not evaluated. The KJOC questionnaire was administered over the phone, and it is possible that this introduced some recording or recall bias as this was administered by one of the study personnel. Furthermore, this questionnaire has not been validated for over-the-phone use, and although the patients seemed comfortable when answering the questions, this could have affected the results. Finally, although the patients in the standard docking group all had the graft fixed in the same manner, there were 7 surgeons who performed these surgeries. While all the surgeons were fellowship-trained sports, shoulder/elbow, or hand surgeons, there may have been some subtle differences in their techniques. However, in comparing the patients of each surgeon with the others, we were unable to find any statistically significant differences in outcomes or complications.