Faculty Bibliography

Orthobiologics are organic and synthetic materials that are used in and outside of the operating room to augment both bone and soft tissue healing. The orthobiologics portfolio has vastly expanded over the years, and it has become imperative for orthopedic surgeons to understand the role and function of this new class of biologic adjuvants. This review will highlight key components and product groups that may be relevant for the practicing orthopedic surgeon in any subspecialty. This by no means is an extensive list of the available products but provides an important overview of the most highlighted products available in the market today. Those discussed include, bone void fillers, extracelluar matrix (ECM) products, platelet-rich plasma (PRP), bone morphogenetic protein-2 (BMP-2), bone marrow aspirate (BMA), bone marrow aspirate concentrate (BMAC), and mesenchymal stem cells (MSCs). These are further categorized into their uses in several subspecialties including, traumatology, sports medicine, sports surgery, and spine surgery.

INTRODUCTION/BACKGROUND:Spondylolysis is an increasingly common diagnoses for young individuals and presents with a wide range of pathological and clinical findings. Most patients are treated conservatively, and surgery is reserved for severe cases. This is a populations study defining the incidence of spondylolysis in the Kids' Inpatient Database (KID) and assess trends in diagnoses, causes, and treatments. METHODS:Retrospective analysis of the prospectively collected information in KID was performed for the years 2003 through 2012. Patients with a diagnosis of spondylolysis (ICD-9-CM 756.11) between the ages of 0 and 20 years in the KID were identified. Incidence of spondylolysis was established using KID-supplied hospital- and year-adjusted trend weights. Demographics including age, race, gender, and Charlson Comorbidity Index were assessed for all spondylolysis patients. Primary outcome measures were yearadjusted and hospital-adjusted incidence of spondylolysis. Secondary outcome measures were concurrent diagnoses and surgical details. RESULTS:Six hundred and sixteen patients with a diagnosis of spondylolysis (329 with primary diagnosis) were identified (female: 53.8%; age: 15.27 ± 3.32 years). The incidence of spondylolysis is 7 per 100,000 patients nationally. Spondylolysis incidence has increased over time (p < 0.001) though the operative rate for spondylolysis has remained the same in the last decade (70% average, p = 0.52). The average CCI is 0.234, the average length of stay is 3.76 days and 92.4% of patients were discharged home. The etiology of the spondylolysis was trauma in 8.6% of patients (3.2% car crash, 1.9% pedestrian, 1.3% fall, 1.3% assault, 1.1% other transport, 1.0% sports, 0.3% motorcycle, 0.2% firearm, 0.2% bicycle; 1.9% reported multiple trauma etiologies). The most common concurrent diagnoses for all spondylolysis patients were spondylolisthesis (28%), idiopathic scoliosis (4.4%), cerebral palsy (1.9%), and spina bifida (1.8%). Four hundred and thirty patients with spondylolysis underwent surgical treatment and 40% of the surgically treated patients had spondylolisthesis. The rate of fusions was 54.9% fusions and 21% decompression, though the rate of fusions or decompressions being performed for spondylolysis has remained the same in the last decade (average fusion rate: 55%; average decompression rate: 18%; both p > 0.05). Levels fused and complications did not differ depending on whether or not decompression was performed (p > 0.05). The posterior-only approach was used in 62.2% of surgeries and were mostly 2 to 3 level procedures (63.5%). Perioperative complications occurred in 8.1% of patients, with the most common complications being device-related (2.3%), respiratory (1.5%), and digestive (1.5%). CONCLUSIONS:The national incidence of spondylolysis has increased over time, and the surgical rate and treatment techniques have remained constant. The most common concurrent diagnoses were idiopathic scoliosis, cerebral palsy, and spina bifida. Further work is required to determine the significance of these trends and associations.

STUDY DESIGN/METHODS:Retrospective review of prospectively collected data. OBJECTIVE:To assess the clinical impact and economic burden of the three most common hospital-acquired conditions (HACs) that occur within 30-day postoperatively for all spine surgeries and to compare these rates with other common surgical procedures. SUMMARY OF BACKGROUND DATA/BACKGROUND:HACs are part of a non-payment policy by the Centers for Medicare and Medicaid Services and thus prompt hospitals to improve patient outcomes and safety. METHODS:Patients more than 18 years who underwent elective spine surgery were identified in American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2013. Primary outcomes were cost associated with the occurrence of three most common HACs. Cost associated with HAC occurrence derived from the PearlDiver database. RESULTS:Ninety thousand five hundred fifty one elective spine surgery patients were identified, where 3021 (3.3%) developed at least one HAC. Surgical site infection (SSI) was the most common HAC (1.4%), then urinary tract infection (UTI) (1.3%) and venous thromboembolism (VTE) (0.8%). Length of stay (LOS) was longer for patients who experienced a HAC (5.1 vs. 3.2 d, P < 0.001). When adjusted for age, sex, and Charlson Comorbidity Index, LOS was 1.48 ± 0.04 days longer (P < 0.001) and payments were $8893 ± $148 greater (P < 0.001) for patients with at least one HAC. With the exception of craniotomy, patients undergoing common procedures with HAC had increased LOS and higher payments (P < 0.001). Adjusted additional LOS was 0.44 ± 0.02 and 0.38 ± 0.03 days for total knee arthroplasty and total hip arthroplasty, and payments were $1974 and $1882 greater. HACs following hip fracture repair were associated with 1.30 ± 0.11 days LOS and $4842 in payments (P < 0.001). Compared with elective spine surgery, only bariatric and cardiothoracic surgery demonstrated greater adjusted additional payments for patients with at least one HAC ($9975 and $10,868, respectively). CONCLUSION/CONCLUSIONS:HACs in elective spine surgery are associated with a substantial cost burden to the health care system. When adjusted for demographic factors and comorbidities, average LOS is 1.48 days longer and episode payments are $8893 greater for patients who experience at least one HAC compared with those who do not. LEVEL OF EVIDENCE/METHODS:3.

STUDY DESIGN/METHODS:Retrospective analysis. OBJECTIVE:To define thoracic compensation and investigate its association with postoperative reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) SUMMARY OF BACKGROUND DATA.: Adult spinal deformity (ASD) patients recruit compensatory mechanisms like pelvic retroversion and knee flexion. However, thoracic hypokyphosis is a less recognized compensatory mechanism. METHODS:Patients enrolled in a multicenter ASD registry undergoing fusions to the pelvis with UIV between T9-L1 were included. Patients were divided into those with postoperative reciprocal thoracic kyphosis (RK: change in unfused TK ≥15°) with and without PJK and those who maintained thoracic alignment (MT). Thoracic compensation was defined as expected thoracic kyphosis (eTK) minus preoperative TK. RESULTS:For RK (n = 117), the mean change in unfused TK was 21.7° vs 6.1° for MT (n = 102) and the mean PJK angle change was 17.6° vs 5.7° for MT (all p < 0.001). RK and MT were similar in age, BMI, gender, and comorbidities. RK had larger preoperative PI-LL mismatch (30.7 vs. 23.6 p = 0.008) and less preoperative TK (22.3 vs. 30.6 p < 0.001), otherwise SVA, PT and TPA were similar. RK patients had more preoperative thoracic compensation (29.9 vs. 20.0, p < 0.001), more PI-LL correction (29.8 vs. 17.3, p < 0.001) and higher rates of PJK (66% vs. 19%, p < 0.001). There were no differences in preoperative HRQOL except RK had worse SRS appearance (2.2 vs. 2.5, p = 0.005). Using a logistic regression model, the only predictor for postoperative reciprocal thoracic kyphosis was more preoperative thoracic compensation. Postoperatively the RK and MT groups were well aligned. Both younger and older (>65y) RK patients had greater thoracic compensation than MT counterparts. The eTK was not significantly different from the postoperative TK for the RK group without PJK (p = 0.566). CONCLUSIONS:The presence of thoracic compensation in adult spinal deformity is the primary determinant of postoperative reciprocal thoracic kyphosis and these patients have higher rates of proximal junctional kyphosis. LEVEL OF EVIDENCE/METHODS:3.

STUDY DESIGN/METHODS:Retrospective analysis. OBJECTIVE:To improve understanding of the impact of comorbid mental health disorders (MHDs) on long-term outcomes following cervical spinal fusion in cervical radiculopathy (CR) or cervical myelopathy (CM) patients. SUMMARY OF BACKGROUND DATA/BACKGROUND:Subsets of patients with CR and CM have MHDs, and their impact on surgical complications is poorly understood. METHODS:Patients admitted from 2009 to 2013 with CR or CM diagnoses who underwent cervical surgery with minimum 2-year surveillance were retrospectively reviewed using New York State's Statewide Planning and Research Cooperative System. Patients with a comorbid MHD were compared against those without (no-MHD). Univariate analysis compared demographics, complications, readmissions, and revisions between MHD and no-MHD cohorts. Multivariate binary logistic regression models identified independent predictors of outcomes (covariates: age, sex, Charlson/Deyo score, and surgical approach). RESULTS:A total of 20,342 patients (MHD: n = 4819; no-MHD: n = 15,523) were included. MHDs identified: depressive (57.8%), anxiety (28.1%), sleep (25.2%), and stress (2.9%). CR patients had greater prevalence of comorbid MHD than CM patients (P = 0.015). Two years postoperatively, all patients with MHD had significantly higher rates of complications (specifically: device-related, infection), readmission for any indication, and revision surgery (all P < 0.05); regression modeling corroborated these findings and revealed combined surgical approach as the strongest predictor for any complication (CR, odds ratio [OR]: 3.945, P < 0.001; CM, OR: 2.828, P < 0.001) and MHD as the strongest predictor for future revision (CR, OR: 1.269, P = 0.001; CM, OR: 1.248, P = 0.008) in both CR and CM cohorts. CONCLUSION/CONCLUSIONS:Nearly 25% of patients admitted for CR and CM carried comorbid MHD and experienced greater rates of any complication, readmission, or revision, at minimum, 2 years after cervical spine surgery. Results must be confirmed with retrospective studies utilizing larger national databases and with prospective cohort studies. Patient counseling and psychological screening/support are recommended to complement surgical treatment. LEVEL OF EVIDENCE/METHODS:3.

BACKGROUND:Despite the potential for profound impact of adult cervical deformity (ACD) on function and health-related quality of life (HRQOL), there are few high-quality studies that assess outcomes of surgical treatment for these patients. OBJECTIVE:To determine the impact of surgical treatment for ACD on HRQOL. METHODS:We conducted a prospective cohort study of surgically treated ACD patients eligible for 1-yr follow-up. Baseline deformity characteristics, surgical parameters, and 1-yr HRQOL outcomes were assessed. RESULTS:Of 77 ACD patients, 55 (71%) had 1-yr follow-up (64% women, mean age of 62 yr, mean Charlson Comorbidity Index of 0.6, previous cervical surgery in 47%). Diagnoses included cervical sagittal imbalance (56%), cervical kyphosis (55%), proximal junctional kyphosis (7%) and coronal deformity (9%). Posterior fusion was performed in 85% (mean levels = 10), and anterior fusion was performed in 53% (mean levels = 5). Three-column osteotomy was performed in 24% of patients. One year following surgery, ACD patients had significant improvement in Neck Disability Index (50.5 to 38.0, P < .001), neck pain numeric rating scale score (6.9 to 4.3, P < .001), EuroQol 5 dimension (EQ-5D) index (0.51 to 0.66, P < .001), and EQ-5D subscores: mobility (1.9 to 1.7, P = .019), usual activities (2.2 to 1.9, P = .007), pain/discomfort (2.4 to 2.1, P < .001), anxiety/depression (1.8 to 1.5, P = .014). CONCLUSION/CONCLUSIONS:Based on a prospective multicenter series of ACD patients, surgical treatment provided significant improvement in multiple measures of pain and function, including Neck Disability Index, neck pain numeric rating scale score, and EQ-5D. Further follow-up will be necessary to assess the long-term durability of these improved outcomes.

OBJECTIVEPseudarthrosis can occur following adult spinal deformity (ASD) surgery and can lead to instrumentation failure, recurrent pain, and ultimately revision surgery. In addition, it is one of the most expensive complications of ASD surgery. Risk factors contributing to pseudarthrosis in ASD have been described; however, a preoperative model predicting the development of pseudarthrosis does not exist. The goal of this study was to create a preoperative predictive model for pseudarthrosis based on demographic, radiographic, and surgical factors.METHODSA retrospective review of a prospectively maintained, multicenter ASD database was conducted. Study inclusion criteria consisted of adult patients (age ≥ 18 years) with spinal deformity and surgery for the ASD. From among 82 variables assessed, 21 were used for model building after applying collinearity testing, redundancy, and univariable predictor importance ≥ 0.90. Variables included demographic data along with comorbidities, modifiable surgical variables, baseline coronal and sagittal radiographic parameters, and baseline scores for health-related quality of life measures. Patients groups were determined according to their Lenke radiographic fusion type at the 2-year follow-up: bilateral or unilateral fusion (union) or pseudarthrosis (nonunion). A decision tree was constructed, and internal validation was accomplished via bootstrapped training and testing data sets. Accuracy and the area under the receiver operating characteristic curve (AUC) were calculated to evaluate the model.RESULTSA total of 336 patients were included in the study (nonunion: 105, union: 231). The model was 91.3% accurate with an AUC of 0.94. From 82 initial variables, the top 21 covered a wide range of areas including preoperative alignment, comorbidities, patient demographics, and surgical use of graft material.CONCLUSIONSA model for predicting the development of pseudarthrosis at the 2-year follow-up was successfully created. This model is the first of its kind for complex predictive analytics in the development of pseudarthrosis for patients with ASD undergoing surgical correction and can aid in clinical decision-making for potential preventative strategies.

BACKGROUND: Primary drivers (PDs) of adult cervical deformity (ACD) have not been described in relation to pre- and early postoperative alignment or degree of correction. OBJECTIVE: To define the PDs of ACD to understand the impact of driver region on global postoperative compensatory mechanisms. METHODS: Primary cervical deformity driver/vertebral apex level were determined: CS = cervical; CTJ = cervicothoracic junction; TH = thoracic; SP = spinopelvic. Patients were evaluated if surgery included PD apex, based on the lowest instrumented vertebra (LIV): CS: LIV