Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients With Hip-Spine Syndrome.

STUDY DESIGN: Prospective cohort. OBJECTIVE: Determine if total hip arthroplasty (THA) changes lumbar spine kinematics during gait in a manner that explains the improvements in back pain seen in patients with hip-spine syndrome. SUMMARY OF BACKGROUND DATA: For patients with hip-spine syndrome, improvements in both hip and back pain have been demonstrated after THA; however, the exact mechanism of improvement in back pain remains unknown, as no corresponding changes in lumbar spine static radiographic parameters have been identified. METHODS: Thirteen patients with severe, unilateral hip osteoarthritis scheduled to undergo THA with concomitant back pain and disability were tested at baseline and 6 months after THA. Harris Hip Score (HHS) and Oswestry Disability Index questionnaires were completed; the static orientation of the spine and pelvis were measured on standing radiographs, and lumbar spine kinematics were measured during treadmill walking using a validated measurement system that matched subject-specific bone models created from CT scans to dynamic biplane radiographs. RESULTS: After THA, both the Oswestry Disability Index (36.3-11.3, P <0.001) and Harris Hip Score (55.7-77.9, P <0.001) improved; however, there were no changes in static intervertebral or pelvis orientation. During gait after THA, the overall lumbar spine (L1 to L5) was less lordotic from heel strike to contralateral toe off ( P <0.001), the L4 and L5 vertebra were less anteriorly tilted by 3.9° ( P =0.038) from midstance to contralateral heel strike and by 3.9° ( P =0.001) during stance, respectively. CONCLUSION: The decreased anterior tilt of the 2 lowest lumbar vertebrae and the corresponding loss of lumbar lordosis may reduce facet loading during the stance phase of gait after THA. This change in lumbar spine kinematics during gait is a potential mechanism to explain the observed improvements in back pain and disability after THA. LEVEL OF EVIDENCE: 4.

Minimum 10-Year Clinical Outcomes After Arthroscopic Capsulolabral Repair for Isolated Posterior Shoulder Instability.

BACKGROUND: Arthroscopic capsulolabral repair for posterior shoulder instability has been shown to improve patient-reported outcomes and return to sport at short-term and midterm follow-up, but long-term outcomes are unknown. PURPOSE: To determine the objective and subjective clinical outcomes of shoulder function after arthroscopic posterior shoulder stabilization at a minimum 10-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 53 patients (55 shoulders) with unidirectional recurrent posterior shoulder instability who underwent arthroscopic capsulolabral repair were evaluated at a mean follow-up of 15.4 years. Outcomes such as the American Shoulder and Elbow Surgeons (ASES) shoulder score, Kerlan-Jobe Orthopaedic Clinic shoulder and elbow score, and subjective strength, stability, range of motion, and pain were evaluated preoperatively and postoperatively at a minimum 10-year follow-up. Outcomes from the same patient cohort were previously collected at 3.0-year follow-up and were evaluated for longitudinal analysis. Subgroup analyses for sport type (contact vs noncontact), position (thrower vs nonthrower), and revision versus nonrevision were performed. Risk factors for revision surgery based on magnetic resonance imaging findings, patient characteristics, and surgical findings were investigated. RESULTS: Arthroscopic capsulolabral repair for posterior shoulder instability led to a statistically significant improvement on all outcome measures, with similar values at short-term (3.0-year) and long-term (15.4-year) follow-up. Across the total population, patients with 19 of 55 shoulders (35%) returned to sport at the same preinjury level, and patients with 33 of 55 shoulders (60%) returned to sport at some level. At long-term follow-up, patients with only 22% of shoulders were involved in the primary sport in which the injury was sustained, with patients with 28% of shoulders discontinuing sporting participation because of ongoing shoulder issues. Throwers trended toward lower Kerlan-Jobe Orthopaedic Clinic scores than nonthrowers both preoperatively (36.5 ± 22.8 vs 48.7 ± 22.9, respectively; P = .10) and postoperatively (57.4 ± 27.0 vs 73.5 ± 26.8, respectively; P = .09) but had similar improvements. Contact and noncontact athletes had similar preoperative and postoperative values, with equal improvements after surgery. With failure defined as revision surgery, an ASES score <60, or a stability value >5, 19 of 55 shoulders (35%) met failure criteria at final follow-up. Overall, 7 of 55 shoulders (13%) underwent revision surgery. At long-term follow-up, patients who underwent revision surgery had worse outcomes than those who did not undergo revision (ASES score: 53.1 ± 25.9 vs 81.8 ± 19.4, respectively; P < .001). An acute injury in the postoperative period (P < .001) and a smaller glenoid bone width on magnetic resonance imaging (P = .02) were the only identified risk factors for revision surgery. CONCLUSION: Arthroscopic capsulolabral repair for posterior shoulder instability was a durable treatment option that improved long-term shoulder pain and function and facilitated return to sport in the majority of patients at a mean follow-up of 15.4 years, although a notable proportion of patients met various criteria for failure.

Pre-Operative Bariatric Surgery Imparts An Increased Risk of Infection, Re-Admission and Operative Intervention Following Elective Instrumented Lumbar Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To evaluate the impact of bariatric surgery on patient outcomes following elective instrumented lumbar fusion. METHODS: A retrospective review of a prospectively collected database was performed. Patients who underwent a bariatric procedure prior to an elective instrumented lumbar fusion were evaluated. Lumbar procedures were performed at a large academic medical center from 1/1/2012 to 1/1/2018. The primary outcome was surgical site infection (SSI) requiring surgical debridement. Secondary outcomes were prolonged wound drainage requiring treatment, implant failure requiring revision, revision secondary to adjacent segment disease (ASD), and chronic pain states. A randomly selected, surgeon and comorbidity-matched group of 59 patients that underwent an elective lumbar fusion during that period was used as a control. Statistical analysis was performed using Student's two-way t-tests for continuous data, with significance defined as P < .05. RESULTS: Twenty-five patients were identified who underwent bariatric surgery prior to elective lumbar fusion. Mean follow-up was 2.4 ± 1.9 years in the bariatric group vs. 1.5 ± 1.3 years in the control group. Patients with a history of bariatric surgery had an increased incidence of SSI that required operative debridement, revision surgery due to ASD, and a higher incidence of chronic pain. Prolonged wound drainage and implant failure were equivalent between groups. CONCLUSION: In the present study, bariatric surgery prior to elective instrumented lumbar fusion was associated increased risk of surgical site infection, adjacent segment disease and chronic pain when compared to non-bariatric patients.

To Cross the Cervicothoracic Junction? Terminating Posterior Cervical Fusion Constructs Proximal to the Cervicothoracic Junction Does Not Impart Increased Risk of Reoperation in Patients With Cervical Spondylotic Myelopathy.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To evaluate the effect of caudal instrumentation level on revision rates following posterior cervical laminectomy and fusion. METHODS: A retrospective review of a prospectively collected database was performed. Minimum follow-up was one year. Patients were divided into two groups based on the caudal level of their index fusion construct (Group 1-cervical and Group 2- thoracic). Reoperation rates were compared between the two groups, and preoperative demographics and radiographic parameters were compared between patients who required revision and those who did not. Multivariate binomial regression analysis was performed to determine independent risk factors for revision surgery. RESULTS: One hundred thirty-seven (137/204) patients received fusion constructs that terminated at C7 (Group 1), while 67 (67/204) received fusion constructs that terminated at T1 or T2 (Group 2). The revision rate was 8.33% in the combined cohort, 7.3% in Group 1, and 10.4% in Group 2. There was no significant difference in revision rates between the 2 groups (P = .43). Multivariate regression analysis did not identify any independent risk factors for revision surgery. CONCLUSION: This study shows no evidence of increased risk of revision in patients with fusion constructs terminating in the cervical spine when compared to patients with constructs crossing the cervicothoracic junction. These findings support terminating the fusion construct proximal to the cervicothoracic junction when indicated. LEVEL OF EVIDENCE: III.

Preclinical Development of a vWF Aptamer to Limit Thrombosis and Engender Arterial Recanalization of Occluded Vessels.

Endothelial surface and circulating glycoprotein von Willebrand factor (vWF) regulates platelet adhesion and is associated with thrombotic diseases, including ischemic stroke, myocardial infarction, and peripheral vascular disease. Thrombosis, as manifested in these diseases, is the leading cause of disability and death in the western world. Current parenteral antithrombotic and thrombolytic agents used to treat these conditions are limited by a short therapeutic window, irreversibility, and major risk of hemorrhage. To overcome these limitations, we developed a novel anti-vWF aptamer, called DTRI-031, that selectively binds and inhibits vWF-mediated platelet adhesion and arterial thrombosis while enabling rapid reversal of this antiplatelet activity by an antidote oligonucleotide (AO). Aptamer DTRI-031 exerts dose-dependent inhibition of platelet aggregation and thrombosis in whole blood and mice, respectively. Moreover, DTRI-031 can achieve potent vascular recanalization of platelet-rich thrombotic occlusions in murine and canine carotid arteries. Finally, DTRI-031 activity is rapidly (<5 min) and completely reversed by AO administration in a murine saphenous vein hemorrhage model, and murine toxicology studies indicate the aptamer is well tolerated. These findings suggest that targeting vWF with an antidote-controllable aptamer potentially represents an effective and safer treatment for thrombosis patients having platelet-rich arterial occlusions in the brain, heart, or periphery.