Vincent J. Alentado

The Relationship of the Medial Patellofemoral Ligament Attachment to the Distal Femoral Physis

Background: No published study has ever described the relationship of the medial patellofemoral ligament (MPFL) attachment to the distal femoral physis in skeletally immature cadaveric specimens. As such, there continues to be much confusion about this relationship, which is important when considering MPFL reconstruction in the skeletally immature patient. Hypothesis: The MPFL footprint is distal to the medial border of the distal femoral physis. Study Design: Descriptive laboratory study. Methods: Sixteen skeletally immature cadaveric specimens were used for this study. The average age of the specimens was 12 years (range, 10-15 years). The MPFL femoral attachment, adductor tubercle, and medial epicondyle were identified in all specimens, and the topography of the distal femoral physis was carefully described. Measurements were then taken of the distance from the medial aspect of the distal femoral physis to the MPFL femoral attachment and the horizontal distance from the MPFL femoral attachment to the point where a femoral tunnel would intersect the undulating femoral physis. All measurements were made with digital calipers. Results: The MPFL attachment was distal to the medial aspect of the femoral physis in all specimens. The MPFL attachment was an average of 8.5 mm distal to the medial aspect of the distal femoral physis. In the coronal plane, the undulating physis was 10.5 mm medial to the MPFL attachment. In all specimens, the undulations of the medial physis were concave directly posterior and lateral to the MPFL attachment and convex anterior to the MPFL attachment. Both the adductor tubercle and the medial epicondyle were also distal to the femoral physis in all specimens. Conclusion: This study has confirmed the findings of others, who have shown that the MPFL femoral attachment lies distal to the medial aspect of the distal femoral physis. In addition, the study findings show that the MPFL femoral attachment is in very close proximity to the distal femoral physis. Clinical Relevance: To facilitate anatomic MPFL reconstruction, Schottle et al described a radiographic method to identify the MPFL femoral attachment on lateral radiographs in skeletally mature patients. Because of the complex physeal anatomy, much confusion exists concerning whether an MPFL femoral tunnel can be placed safely in the pediatric patient. The findings of this study suggest that anatomic MPFL reconstruction may be accomplished with a tunnel angled distally and anteriorly to avoid injury to the distal femoral physis.

Predisposing Characteristics of Adjacent Segment Disease After Lumbar Fusion.

Study Design. Retrospective Review. Objective. The aim of this study was to determine medical, radiographic, and surgical risk factors for the development of adjacent segment disease (ASD) after lumbar fusion. Summary of Background Data. ASD is a recognized outcome of spinal fusion that leads to increased costs and debilitating symptoms for patients. However, a comprehensive understanding of risk factors for the development of this surgical outcome does not exist. Methods. The medical records of patients who received their first lumbar fusion for any indication were retrospectively examined for preoperative medical comorbidities and medications, as well as surgical approach and perioperative complications. A blinded reviewer assessed radiographs for each patient to examine sagittal alignment after fusion. Multivariable logistic regression was used to model the risk of developing ASD on the basis of one or more predictors. Results. A total of 137 patients fit the inclusion criteria; 9% required a follow-up operation for degeneration at segments adjacent to the fusion. The ASD group had a mean follow-up of 21.1 months prior to revision surgery and an overall follow-up of 41.0 months. The average follow-up in the control group was 14.0 months. Statistically significant independent predictors of developing ASD included antidepressant use [odds ratio (OR)u200a=u200a5.4], diagnosis of degenerative scoliosis (ORu200a=u200a34.2), fusion of L4-S1 (ORu200a=u200a56.5), having no decompressions adjacent to the fusion, and low sacral slope (ORu200a=u200a0.9). No patient who developed ASD received a decompression adjacent to the fusion such that an OR could not be generated for this independent predictor. Conclusion. This study is the first to use a combination of medical, surgical, and postoperative sagittal balance as risk factors for the development of adjacent segment disease after lumbar fusion. The awareness of these risk factors may allow for better patient selection and surgical technique to decrease the probability of acquiring this adverse outcome. Level of Evidence: 4

Comparison of clinical outcomes in decompression and fusion versus decompression only in patients with ossification of the posterior longitudinal ligament: a meta-analysis

OBJECTIVE Ossification of the posterior longitudinal ligament (OPLL) is a pathological calcification or ossification of the PLL, predominantly occurring in the cervical spine. Although surgery is often necessary for patients with symptomatic neurological deterioration, there remains controversy with regard to the optimal surgical treatment. In this systematic review and meta-analysis, the authors identified differences in complications and outcomes after anterior or posterior decompression and fusion versus after decompression alone for the treatment of cervical myelopathy due to OPLL. METHODS A MEDLINE, SCOPUS, and Web of Science search was performed for studies reporting complications and outcomes after decompression and fusion or after decompression alone for patients with OPLL. A meta-analysis was performed to calculate effect summary mean values, 95% CIs, Q statistics, and I(2) values. Forest plots were constructed for each analysis group. RESULTS Of the 2630 retrieved articles, 32 met the inclusion criteria. There was no statistically significant difference in the incidence of excellent and good outcomes and of fair and poor outcomes between the decompression and fusion and the decompression-only cohorts. However, the decompression and fusion cohort had a statistically significantly higher recovery rate (63.2% vs 53.9%; p < 0.0001), a higher final Japanese Orthopaedic Association score (14.0 vs 13.5; p < 0.0001), and a lower incidence of OPLL progression (< 1% vs 6.3%; p < 0.0001) compared with the decompression-only cohort. There was no statistically significant difference in the incidence of complications between the 2 cohorts. CONCLUSIONS This study represents the only comprehensive review of outcomes and complications after decompression and fusion or after decompression alone for OPLL across a heterogeneous group of surgeons and patients. Based on these results, decompression and fusion is a superior surgical technique compared with posterior decompression alone in patients with OPLL. These results indicate that surgical decompression and fusion lead to a faster recovery, improved postoperative neurological functioning, and a lower incidence of OPLL progression compared with posterior decompression only. Furthermore, decompression and fusion did not lead to a greater incidence of complications compared with posterior decompression only.

347 Clinical Outcomes Following Spinal Fusion Using an Intraoperative Computed Tomographic Three-Dimensional Imaging System.

demographic/clinical variables (age 1⁄4 65, sex, race, body mass index (BMI), ASA score, functional status, inpatient/outpatient status, smoking, hypertension, Charlson Comorbidity Index) using multivariable regression. Means, standard errors, odds ratio (OR), and 95% confidence intervals (CIs) are reported. Significance was assessed at P, .05. RESULTS: Of 18 067 subjects (ACDF 1⁄4 17 296, C-ADR 1⁄4 771), C-ADR subjects were on average younger (,65 years: 97.4% vs 84.2%; P , .001), less obese (nonobese: 6.10% vs 49.1%; P , .001), less physically burdened (ASA 1: 13.1% vs 4.3%; ASA 3-4: 17.9% vs 38.3%; P , .001), less functionally dependent (0.5% vs 2.2%; P , .001), and presented with fewer overall comorbidities (3.9% vs 6.4%; P , .001). Overall, 31 (0.17%) patients died. Univariate analyses showed that C-ADR had shorter operation time (111.27 6 1.89-minutes vs 125.59 6 0.53-minutes; P , .001), shorter hospital length of stay (HLOS) (1.06 6 0.03 days vs 1.64 6 0.04 days; P 1⁄4 .003), and higher likelihood of being discharged to home (99.5% vs 96.9%, P , .001). Multivariable analysis confirmed C-ADR association with shorter operation time (B 1⁄4 29.37; 95% CI, 214.34 to 24.01) and with greater likelihood of returning home (OR, 2.74 [1.01, 7.41]), while a nonsignificant statistical trend was demonstrated for HLOS (B 1⁄4 20.35; 95% CI, 20.73 to 0.03). Incidences of early complications did not differ between C-ADR and ACDF (1.4% vs 2.5%, P 1⁄4 .620).INTRODUCTIONnThe O-arm Multidimensional Surgical Imaging System provides superior accuracy of pedicle screw insertion compared with free-hand and fluoroscopic approaches. However, no studies have investigated the clinical relevance of increased accuracy. The objective of this study was to investigate the clinical outcomes following spinal fusion using O-arm navigation. We hypothesized that increased accuracy with O-arm navigation decreases the risk of reoperation compared with free-hand and fluoroscopic guidance.nnnMETHODSnA consecutive retrospective review of all patients undergoing noncervical spinal fusion at a single tertiary-care institution between December 2012 and December 2014 was conducted. Multivariable linear and Cox proportional hazards regression were used to investigate the association between O-arm navigation and outcomes.nnnRESULTSnAmong 1208 procedures, 614 were performed with O-arm navigation, 356 using free-hand techniques, and 238 using fluoroscopy. The most common indication for surgery was spondylolisthesis (56.2%), and most patients underwent posterolateral fusion (75.7%). The average fusion spanned 4.53 vertebral levels. O-arm patients experienced shorter hospital stays than patients undergoing free-hand and fluoroscopy approaches (4.72 vs 5.07 days, P < .01), and multivariable linear regression revealed O-arm as an independent predictor of shorter hospital stays compared with fluoroscopy (β = 0.50, P < .01). O-arm was significantly associated with decreased risk of reoperation for hardware failure (2.9% vs 5.9%, relative risk [RR] 0.50, P = .01), screw misplacement (1.6% vs 4.2%, RR 0.39, P < .01), and all-cause reoperation (5.2% vs 10.9%, RR 0.48, P < .01); these findings were corroborated with Kaplan-Meier survival analysis. Cox proportional hazards modeling revealed that O-arm navigation was an independent predictor of reoperation risk, because free-hand (hazard ratio [HR] 1.97, P < .01) and fluoroscopic (HR 2.32, P < .01) methods both predicted greater risk of reoperation.nnnCONCLUSIONnThis is the first study to investigate clinical outcomes associated with O-arm navigation following spinal fusion. O-arm navigation predicted decreased length of hospital stay and decreased the risk of reoperation to half the risk of free-hand and fluoroscopic approaches.

Anterior Cervical Decompression and Fusion

Anterior cervical decompression and fusion (ACDF) is a commonly utilized surgical treatment option for patients with cervical radiculopathy or myelopathy secondary to cervical spondylosis that is refractory to nonsurgical management. The primary aim of ACDF is physical decompression of neurologic structures, restoration of cervical alignment, and achievement of bony fusion. ACDF offers excellent results for the vast majority of patients. However, careful patient selection and surgical technique are vital to the success of ACDF surgery. The information presented within this chapter can better inform spinal surgeons on strategies for patient selection, surgical technique, and complication avoidance in patients deemed suitable candidates for ACDF surgery.

103 Insurance Status Predicts Patient Safety and Care Quality in the Lumbar Spine Fusion Population.

INTRODUCTIONnLumbar fusion is a common and costly procedure in the United States. Reimbursement for surgical procedures is increasingly tied to care quality and patient safety as part of value-based reimbursement programs. The incidence of adverse quality events among lumbar fusion patients is unknown using the definition of care quality (named patient safety indicators [PSI]) utilized by the Centers for Medicare and Medicaid Services (CMS). Disparities in PSI incidence have been observed across insurance groups in other surgical spine populations. The association between insurance status and the incidence of adverse care quality as measured by PSI is unknown in lumbar fusion patients.nnnMETHODSnNationwide inpatient sample (NIS) data were queried for all cases of inpatient lumbar fusion from 1998 to 2011. Patients were excluded if other or missing was listed for primary insurance status and if age was less than 18 years. Incidence of adverse patient safety events (PSI) was determined using publicly available lists of International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. Logistic regression models were used to determine the association between primary payer status (Medicaid/self-pay relative to private insurance) and the incidence of PSI.nnnRESULTSnFrom 1998 to 2011, 564u2009930 lumbar fusion procedures were recorded in the NIS. After applying inclusion criteria, 461u2009417 remained for analysis. The national incidence of PSI was calculated to be 2445 per 100u2009000 patient-years of observation, or approximately 2.5% After adjusting for patient demographics and hospital characteristics, Medicaid/self-pay patients had significantly greater odds of experiencing one or more PSI during the inpatient episode relative to privately insured patients (odds ratio, 1.16; 95% confidence interval, 1.07-1.27).nnnCONCLUSIONnAmong patients undergoing inpatient lumbar fusion, insurance status predicts adverse health care quality events used to determine hospital reimbursement by CMS. The source of this disparity must be studied to improve the quality of care delivered to vulnerable patient populations.CONCLUSION: The primary factor contributing to patient injury was evenly divided between the perioperative period and outside the perioperative period. Within the perioperative period, a known risk of the procedure was the primary factor approximately 2.5 times more often than technical performance. Technical performance of surgery caused patient injury in a minority of cases. Improving patient safety in neurosurgical practice requires careful attention to differential diagnosis, consideration of all relevant clinical data, active pursuit of good physician-patient relationships, careful attention to the perioperative period, and adequate monitoring of patients receiving nonsurgical treatment. The consent process should be improved to better help patients understand the possible outcomes of surgery.