Harry T. Mai

The NFL Orthopaedic Surgery Outcomes Database (NO-SOD) The Effect of Common Orthopaedic Procedures on Football Careers

Background: Injuries are inherent to the sport of American football and often require operative management. Outcomes have been reported for certain surgical procedures in professional athletes in the National Football League (NFL), but there is little information comparing the career effect of these procedures. Purpose: To catalog the postoperative outcomes of orthopaedic procedures in NFL athletes and to compare respective prognoses and effects on careers. Study Design: Case series; Level of evidence, 4. Methods: Athletes in the NFL undergoing procedures for anterior cruciate ligament (ACL) tears, Achilles tendon tears, patellar tendon tears, cervical disc herniation, lumbar disc herniation, sports hernia, knee articular cartilage repair (microfracture technique), forearm fractures, tibial shaft fractures, and ankle fractures were identified through team injury reports or other public records. Game and performance statistics during the regular season were collected before and after surgery. Statistical analysis was performed with significance accepted as P < .05. Results: A total of 559 NFL athletes were included. Overall, 79.4% of NFL athletes returned to play after an orthopaedic procedure. Forearm open reduction and internal fixation (ORIF), sports hernia repair, and tibia intramedullary nailing (IMN) led to significantly higher return-to-play (RTP) rates (90.2%-96.3%), while patellar tendon repair led to a significantly lower rate (50%) (P < .001). Athletes undergoing ACL reconstruction (ACLR), Achilles tendon repair, patellar tendon repair, and ankle fracture ORIF had significant declines in games played at 1 year and recovered to baseline at 2 to 3 years after surgery. Athletes undergoing ACLR, Achilles tendon repair, patellar tendon repair, and tibia IMN had decreased performance in postoperative season 1. Athletes in the Achilles tendon repair and tibia IMN cohorts recovered to baseline performance, while those in the ACLR and patellar tendon repair cohorts demonstrated sustained decreases in performance. Conclusion: ACLR, Achilles tendon repair, and patellar tendon repair have the greatest effect on NFL careers, with patellar tendon repair faring worst with respect to the RTP rate, career length after surgery, games played, and performance at 1 year and 2 to 3 years after surgery.

Differences in bone mineral density of fixation points between lumbar cortical and traditional pedicle screws

BACKGROUND CONTEXT The use of a novel lumbar pedicle cortical bone trajectory (CBT) screw has recently gained popularity, allowing for a minimally invasive approach and potentially improved screw purchase. However, to date, no studies have identified the ideal patient population to utilize this technology. PURPOSE This study reports the bone mineral density (BMD) using Hounsfield units (HUs) along a CBT screw pathway. Patients with a greater difference in density of bone in the lumbar vertebrae between the fixation points of the CBT and traditional pedicle screw may be optimal candidates to realize the advantages of this technique. STUDY DESIGN/SETTING A cross-sectional observational anatomic study was carried out. PATIENT SAMPLE The sample comprised 180 randomly selected patients with lumbar computed tomography imaging from L1 to L5 spinal levels. OUTCOME MEASURES This study used computed tomography image-derived HUs as a metric for BMD. METHODS A total of 180 patients without previous lumbar surgery with computed tomography imaging of the lumbar spine met the inclusion criteria. Patients were chosen randomly from an institutional database based on age (evenly distributed by decade of life) and gender. Hounsfield units were measured at the expected end fixation point for both a cortical (superior/posterior portion of the vertebral body) and traditional pedicle trajectory (mid-vertebral body). RESULTS Hounsfield unit values measured at the end fixation point for the CBT screw were significantly greater than that of the traditional pedicle screw in all age groups. The relative difference in HU values significantly increased with each decade of age (p<.001) and caudal lumbar level (p<.001). In the osteoporotic group, as determined by well-established HU values, there was a significantly greater difference in the BMD of the CBT fixation point compared with the traditional trajectory (p=.048-<.001). CONCLUSIONS Bone mineral density as measured by HU values for the fixation point of the CBT screw is significantly greater than that of the traditional pedicle screw. This difference is even more pronounced when comparing osteoporotic and elderly patients to the general population. The data in this study suggest that the potential advantages from the CBT screw such as screw purchase may increase linearly with age and in osteoporotic patients.

The Triangle Model of Congenital Cervical Stenosis.

Study Design. Retrospective Cross-Sectional Study Objective. Identify the pathoanatomical features of the cervical spine associated with congenital stenosis Summary of Background Data. Congenital cervical stenosis (CCS) describes a patient with a decreased spinal canal diameter at multiple levels of the cervical spine in the absence of degenerative changes. Despite recognition of CCS throughout the literature, the anatomical features that lead to this condition have not been established. Knowledge of the pathoanatomy behind CCS may lead to alterations in surgical technique for this patient population that may improve outcomes. Methods. From 1000 cervical MRIs between January 2000 and December 2014, CCS was identified in 68 patients using a strict definition of age less than 50 years with mid-sagittal canal diameters (mid-SCD) (<10 mm) at multiple sub-axial cervical levels (C3–C7). A total of 68 patients met the inclusion criteria for this group. Fourteen controls with normal SCDs (>14 mm) at all cervical levels were used for comparison. Anatomic measurements obtained at each level (C3–C7) included: coronal vertebral body, AP vertebral body, pedicle width, pedicle length, laminar length, AP lateral mass, posterior canal distance, lamina-pedicle angle, and lamina-disc angle (LDA). Statistical significance was defined as P < 0.01. Results. CCS patients demonstrated significantly different anatomical measurements when compared with controls. Significantly smaller lateral masses, lamina lengths, lamina-pedicle angles, and larger LDAs were identified at levels C3 to C7 in the CCS group (P < 0.01). These anatomic components form a right triangle that illustrates the cumulative narrowing effect on space for the spinal cord. Conclusion. The pathoanatomy of CCS is associated with a decrease in the lamina-pedicle angle and an increase in the LDA ultimately leading to a smaller SCD. The global changes in CCS are best illustrated by this triangle model and are driven by the posterior elements of the cervical spine. Level of Evidence: 4

Epidemiology and Outcomes of Vertebral Artery Injury in 16 582 Cervical Spine Surgery Patients: An AOSpine North America Multicenter Study.

Study Design: A multicenter retrospective case series was compiled involving 21 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005 and 2011 and who sustained a vertebral artery injury (VAI). Objective: To report the frequency, risk factors, outcomes, and management goals of VAI in patients who have undergone cervical spine surgery. Methods: Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36). Results: VAIs were identified in a total of 14 of 16 582 patients screened (8.4 per 10 000). The mean age of patients with VAI was 59 years (±10) with a female predominance (78.6%). Patient diagnoses included myelopathy, radiculopathy, cervical instability, and metastatic disease. VAI was associated with substantial blood loss (770 mL), although only 3 cases required transfusion. Of the 14 cases, 7 occurred with an anterior-only approach, 3 cases with posterior-only approach, and 4 during circumferential approach. Fifty percent of cases of VAI with available preoperative imaging revealed anomalous vessel anatomy during postoperative review. Average length of hospital stay was 10 days (±8). Notably, 13 of the 14 (92.86%) cases resolved without residual deficits. Compared to preoperative baseline NDI, Nurick, mJOA, and SF-36 scores for these patients, there were no observed changes after surgery (P = .20-.94). Conclusions: Vertebral artery injuries are potentially catastrophic complications that can be sustained from anterior or posterior cervical spine approaches. The data from this study suggest that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits.

Performance-Based Outcomes after Anterior Cruciate Ligament Reconstruction in Professional Athletes Differ between Sports

Background: Excellent outcomes have been reported for anterior cruciate ligament (ACL) reconstruction (ACLR) in professional athletes in a number of different sports. However, no study has directly compared these outcomes between sports. Purpose: To determine if differences in performance-based outcomes exist after ACLR between professional athletes of each sport. Study Design: Cohort study; Level of evidence, 3. Methods: National Football League (NFL), National Basketball Association (NBA), National Hockey League (NHL), and Major League Baseball (MLB) athletes undergoing primary ACLR for an acute rupture were identified through an established protocol of injury reports and public archives. Sport-specific performance statistics were collected before and after surgery for each athlete. Return to play (RTP) was defined as a successful return to the active roster for at least 1 regular-season game after ACLR. Results: Of 344 professional athletes who met the inclusion criteria, a total of 298 (86.6%) returned to play. NHL players had a significantly higher rate of RTP (95.8% vs 83.4%, respectively; P = .04) and a shorter recovery time (258 ± 110 days vs 367 ± 268 days, respectively; P < .001) than athletes in all the other sports. NFL athletes experienced significantly shorter careers postoperatively than players in all the other sports (2.1 vs 3.2 years, respectively; P < .001). All athletes played fewer games (P ≤ .02) 1 season postoperatively, while those in the NFL had the lowest rate of active players 2 and 3 seasons postoperatively (60%; P = .002). NBA and NFL players showed decreased performance at season 1 after ACLR (P ≤ .001). NFL players continued to have lower performance at seasons 2 and 3 (P = .002), while NBA players recovered to baseline performance. Conclusion: The data indicate that NFL athletes fare the worst after ACLR with the lowest survival rate, shortest postoperative career length, and sustained decreases in performance. NHL athletes fare the best with the highest rates of RTP, highest survival rates, longest postoperative career lengths, and no significant changes in performance. The unique physical demand that each sport requires is likely one of the explanations for these differences in outcomes.

Does the level of cervical disc herniation surgery affect performance-based outcomes in national football league athletes?

Study Design. Retrospective cohort study. Objective. The aim of this study was to determine whether the level of a cervical disc herniation (CDH) procedure will uniquely impact performance-based outcomes in elite athletes of the National Football League (NFL). Summary of Background Data. Comparative assessments of postsurgical outcomes in NFL athletes with CDH at different levels are unknown. Further, the surgical decision-making for these types of injuries in professional football athletes remains controversial. Methods. NFL players with a CDH injury at a definitive cervical level were identified through a review of publicly available archives. Injuries were divided into upper- (C2-C4) and lower-level (C4-T1) CDH. The impact on player outcomes was determined by comparing return to play statistics and calculating a “Performance Score” for each player on the basis of pertinent statistical data, both before and after surgery. Results. A total of 40 NFL athletes met inclusion criteria. In the upper-level group, 10 of 15 (66.6%) players successfully returned to play an average of 44.6 games over 2.6 years. The lower-level cohort had 18 of 25 (72%) players return to play with an average of 44.1 games over 3.1 years. There was no significant difference in the rate of return to play (P = 0.71). Postsurgical performance scores of the upper and lower-level groups were 1.47 vs. 0.69 respectively, with no significant difference between these groups (P = 0.06). Adjacent segment disease requiring reoperation occurred in 10% of anterior cervical discectomy and fusion patients. In 50% of foraminotomy patients, a subsequent fusion was required. Conclusion. A uniquely high percentage of upper-level disc herniations develop in NFL athletes, and although CDH injuries present career threatening implications, an upper-level CDH does not preclude a player from successfully returning to play at a competitive level. In fact, these athletes showed comparable postsurgical performance to those athletes who underwent CDH procedures at lower cervical levels. Level of Evidence: 4

A cross-sport comparison of performance-based outcomes of professional athletes following primary microfracture of the knee

BACKGROUND The purpose of this study was to compare performance-based outcomes among professional athletes in four major North American sports following microfracture to treat symptomatic chondral defects of the knee. METHODS Major League Baseball (MLB), National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL) athletes who underwent primary unilateral microfracture of the knee were identified through a previously reported protocol based on public sources. Successful return-to-play was defined as returning for at least one professional regular season game after surgery. Regular season player statistics and sport-specific performance scores were compiled for each player. Each player served as his own control, with the season prior to surgery defined as baseline. Comparisons across sports were enabled by adjusting for expected season and career length differences between sports and by calculating percent changes in performance. RESULTS One hundred thirty one professional athletes who underwent microfracture were included. One hundred three athletes (78.6%) successfully returned to play. The ratio of games started-to-games played before surgery was found to be a significant positive independent predictor of returning (p = 0.002). Compared with their preoperative season, basketball and baseball players demonstrated significantly decreased performance one season after surgery (-14.8%, p = 0.029 and -12.9%, p = 0.002, respectively) that was recoverable to baseline by postoperative seasons 2-3 for baseball players but not for basketball players (-9.7%, p = 0.024). CONCLUSION Knee microfracture surgery is associated with a high rate of return to the professional level. However, the impact of this procedure on postoperative performance varied significantly depending on sport.

Reply to Comments pertaining to “Differences in bone mineral density of fixation points between lumbar cortical and traditional pedicle screws.”

My comments pertain to the study by Mai et al., “Differences in Bone Mineral Density of Fixation Points Between Lumbar Cortical and Traditional Pedicle Screws.” The study design and results make sense and the regions of interest differences are believable. My concern, however, is with the nomenclature and terminology. The “fixation points” of the pedicle screws were not accurately described. For those of us who use pedicle screws routinely, I believe that the fixation is within the pedicle itself and not within the vertebral body, as suggested by the authors. I am somewhat surprised that the editors did not comment upon this. It is well known that pedicle screws come in different diameters specifically to maximize fixation within the pedicle. Most systems today have diameters of 4.5 mm up to 8.5 mm. Thus, I think the study itself is valid, but the terminology is misleading and should be pointed out to readers, especially young surgeons who are just beginning their practice who may not yet have the experience to fully understand how to optimize pedicle screw fixation.

Accessibility of the Cervicothoracic Junction Through an Anterior Approach: An MRI-based Algorithm.

Study Design. Cross-sectional observational study. Objective. To formulate a reliable method and modality for preoperative planning and to determine the effects of height, body mass index (BMI), and age on accessibility to the upper thoracic vertebrae through an anterior cervical approach. Summary of Background Data. Various modalities have been proposed to determine the lowest spinal-level accessible through a traditional anterolateral cervical approach and the consequent need for manubriotomy. Past methods have routinely involved a variety of imaging studies such as plain radiographs and computed tomography but the reliability of these methods has not been assessed. Methods. The Magnetic Resonance Imaging (MRI) images of 180 patients classified by age and gender were evaluated and the most caudal accessible intervertebral disc space was determined from an approach angle beginning at the suprasternal notch. Plain cervical radiographs were also reviewed when available. In patients with multiple imaging studies, the reliability of the measurements was compared. Rate of accessibility was compared across different heights, BMIs, and ages. Results. A novel algorithm that utilized both the scout and mid-sagittal T2 MRIs was able to determine the most caudal cervicothoracic level accessible for anterior access in 93.3% of patients with a reliability of 96.8%. Conversely, plain radiograph evaluation led to low reliability (66.7%) and low agreement with MRI (60%) with an average error of one spinal level. In this patient sample, the T1 to T2 disc space was accessible in 82.7% of patients. Age and BMI were independent variables associated with accessibility (p < 0.01) while height was determined not to be significant (p = 0.09). Conclusion. Data in this study suggest an MRI-based algorithm with a combination of scout and sagittal T2 images offers a reliable and consistent assessment of accessibility to upper thoracic levels through an anterior approach. Age and body mass index are major determinants of accessibility. Level of Evidence: 3