Clinical outcomes and complications after biportal endoscopic spine surgery: a comprehensive systematic review and meta-analysis of 3673 cases.

PURPOSE: Current literature suggests that biportal spinal endoscopy is safe and effective in treating lumbar spine pathology such as lumbar disc herniation, lumbar stenosis, and degenerative spondylolisthesis. No prior study has investigated the postoperative outcomes or complication profile of the technique as a whole. This study serves as the first comprehensive systematic review and meta-analysis of biportal spinal endoscopy in the lumbar spine. METHODS: A PubMed literature search provided over 100 studies. 42 papers were reviewed and 3673 cases were identified with average follow-up time of 12.5 months. Preoperative diagnoses consisted of acute disc herniation (1098), lumbar stenosis (2432), and degenerative spondylolisthesis (229). Demographics, operative details, complications, and perioperative outcome and satisfaction scores were analyzed. RESULTS: Average age was 61.32 years, 48% male. 2402 decompressions, 1056 discectomies, and 261 transforaminal lumbar Interbody fusions (TLIFs) were performed. Surgery was performed on 4376 lumbar levels, with L4-5 being most common(61.3%). 290 total complications occurred, 2.23% durotomies, 1.29% inadequate decompressions, 3.79% epidural hematomas, and < 1% transient nerve root injuries, infections, and iatrogenic instability. Significant improvement in VAS-Back, VAS-Leg, ODI, and Macnab Scores were seen across the cohort. CONCLUSION: Biportal spinal endoscopy is a novel method to address pathology in the lumbar spine with direct visualization through an endoscopic approach. Complications are comparable to previously published rates. Clinical outcomes demonstrate effectiveness. Prospective studies are required to assess the efficacy of the technique as compared to traditional techniques. This study demonstrates that the technique can be successful in the lumbar spine.

Delayed Diagnosis Is the Primary Cause of Sarcoma Litigation: Analysis of Malpractice Claims in the United States.

BACKGROUND: Sarcoma care is highly litigated in medical malpractice claims. Understanding the reasons for litigation and legal outcomes in sarcoma care may help physicians deliver more effective and satisfying care to patients while limiting their legal exposure. However, few studies have described malpractice litigation in sarcoma care. QUESTIONS/PURPOSES: (1) What percentage of sarcoma malpractice cases result in a defendant verdict? (2) What is the median indemnity payment for cases that result in a plaintiff verdict or settlement? (3) What are the most common reasons for litigation, injuries sustained, and medical specialties of the defendant physicians? (4) What are the factors associated with plaintiff verdicts or settlements and higher indemnity payments? METHODS: The national medicolegal database Westlaw was queried for medical malpractice cases pertaining to sarcomas that reached verdicts or settlements. Cases from 1982 to 2018 in the United States were included in the study to evaluate for trends in sarcoma litigation. Demographic and clinical data, tumor characteristics, reasons for litigation, injuries, and legal outcomes were recorded for each case. A univariate analysis was performed to identify factors associated with plaintiff verdicts or settlements and higher indemnity payments, such as tumor characteristics, defendant's medical or surgical specialty, reason for litigation, and injuries sustained. A total of 92 cases related to sarcomas were included in the study, of which 40 were related to bone sarcomas and 52 were related to soft-tissue sarcomas. Eighty-five percent (78 of 92) of cases involved adult patients (mean age ± SD: 40 ± 15 years) while 15% (14 of 92) of cases involved pediatric patients (mean age ± SD: 12.5 ± 5 years). RESULTS: Thirty-eight percent (35 of 92) of the included cases resulted in a defendant verdict, 30% (28 of 92) resulted in a plaintiff verdict, and 32% (29 of 92) resulted in a settlement. The median (interquartile range [IQR]) indemnity payment for plaintiff verdicts and settlements was USD 1.9 million (USD 0.5 to USD 3.5 million). Median (IQR) indemnity payments were higher for cases resulting in a plaintiff verdict than for cases that resulted in a settlement (USD 3.3 million [1.1 to 5.7 million] versus USD 1.2 million [0.4 to 2.4 million]; difference of medians = USD 2.2 million; p = 0.008). The most common reason for litigation was delayed diagnosis of sarcoma (91%; 84 of 92) while the most common injuries cited were progression to metastatic disease (51%; 47 of 92) and wrongful death (41%; 38 of 92). Malpractice claims were most commonly filed against primary care physicians (26%; 28 of 109 defendants), nononcology-trained orthopaedic surgeons (23%; 25 of 109), and radiologists (15%; 16 of 109). Cases were more likely to result in a ruling in favor of the plaintiff or settlement if a delay in diagnosis occurred despite suspicious findings on imaging or pathologic findings (80% versus 51%; odds ratio 3.84 [95% CI 1.34 to 11.03]; p = 0.02). There were no differences in indemnity payments with the numbers available in terms of tumor type, tumor location, defendant specialty, reason for litigation, and resulting injuries. CONCLUSIONS: Many lawsuits were made against primary care physicians, nononcology-trained orthopaedic surgeons, or radiologists for a delayed diagnosis of sarcoma despite the presence of imaging or histologic findings suspicious for malignancy. Although previous studies of bone and soft-tissue sarcomas have not shown a consistent association between time to diagnosis and decreased survival, our study suggests that physicians are still likely to lose these lawsuits because of the perceived benefits of an early diagnosis. CLINICAL RELEVANCE: Physicians can mitigate their malpractice risk while reducing delays in diagnosis of sarcomas by carefully reviewing all existing diagnostic studies, establishing closed-loop communication protocols to communicate critical findings from diagnostic studies, and developing policies to facilitate second-opinion consultation, particularly for imaging studies, with an experienced sarcoma specialist. Musculoskeletal oncologists may be able to help further reduce the rates of malpractice litigation in sarcoma care by helping patients understand that delays in diagnosis do not necessarily constitute medical malpractice.

Novel in vivo mouse model of shoulder implant infection.

BACKGROUND: Animal models are used to guide management of periprosthetic implant infections. No adequate model exists for periprosthetic shoulder infections, and clinicians thus have no preclinical tools to assess potential therapeutics. We hypothesize that it is possible to establish a mouse model of shoulder implant infection (SII) that allows noninvasive, longitudinal tracking of biofilm and host response through in vivo optical imaging. The model may then be employed to validate a targeting probe (1D9-680) with clinical translation potential for diagnosing infection and image-guided débridement. METHODS: A surgical implant was press-fit into the proximal humerus of c57BL/6J mice and inoculated with 2 µL of 1 × 103 (e3), or 1 × 104 (e4), colony-forming units (CFUs) of bioluminescent Staphylococcus aureus Xen-36. The control group received 2 µL sterile saline. Bacterial activity was monitored in vivo over 42 days, directly (bioluminescence) and indirectly (targeting probe). Weekly radiographs assessed implant loosening. CFU harvests, confocal microscopy, and histology were performed. RESULTS: Both inoculated groups established chronic infections. CFUs on postoperative day (POD) 42 were increased in the infected groups compared with the sterile group (P < .001). By POD 14, osteolysis was visualized in both infected groups. The e4 group developed catastrophic bone destruction by POD 42. The e3 group maintained a congruent shoulder joint. Targeting probes helped to visualize low-grade infections via fluorescence. DISCUSSION: Given bone destruction in the e4 group, a longitudinal, noninvasive mouse model of SII and chronic osteolysis was produced using e3 of S aureus Xen-36, mimicking clinical presentations of chronic SII. CONCLUSION: The development of this model provides a foundation to study new therapeutics, interventions, and host modifications.

Does the use of tranexamic acid intraoperatively reduce postoperative blood loss and complications following biportal endoscopic lumbosacral decompression?

Background: Biportal endoscopic spine surgery is an effective minimally invasive technique for treating common lumbar pathologies. We aim to evaluate the impact of intraoperative tranexamic acid (TXA) use on postoperative blood loss in biportal endoscopic decompression surgery. Methods: Patients undergoing biportal endoscopic lumbar discectomies and decompressions either by same day surgery or overnight stay at a single institution beginning in October 2021 were prospectively enrolled. This study was non-randomized, non-blinded with the first cohort of consecutive patients receiving 1 g of intravenous TXA intra-operatively before closure and the second cohort of consecutive patients receiving no TXA. Exclusion criteria included any revision surgery, any surgery for the diagnosis of spinal instability, infection, tumor, or trauma, any contraindication for TXA. Results: Eighty-four patients were included in the study, with 45 (54%) receiving TXA and 39 (46%) not receiving TXA. Median follow-up was 168 days [interquartile range (IQR), 85-368 days]. There were no differences in patient or surgical characteristics between cohorts. Estimated blood loss (EBL) was similar (P=0.20), while post-operative drain output was significantly lower in the TXA cohort (P=0.0028). Single level discectomies had significantly less drain output as compared to 2 level unilateral laminotomy, bilateral decompression (ULBD) cases (P<0.005). Post-operative complications were similar, with low rates of wound complication (1.2%) and transient postoperative weakness (2.4%, P>0.99 for both). Oswestry disability index (ODI), visual analog scale (VAS) back and VAS leg scores decreased significantly; the absolute decrease in scores did not differ between groups (P=0.71, 0.22, 0.86, respectively). Conclusions: Systemic intraoperative TXA administration is associated with a significant decrease in post-operative blood loss in biportal spinal endoscopy, with no impact on the improvement in patient-reported outcomes (PROs) or rate of post-operative complications. Single level biportal discectomies had significantly less postoperative drainage with TXA and may not need drains postoperatively. Larger, randomized studies are necessary to evaluate the cost-effectiveness of TXA use in biportal spinal endoscopy.

Extreme oxatriquinanes: structural characterization of α-oxyoxonium species with extraordinarily long carbon-oxygen bonds.

The first stable α-oxyoxonium species have been synthesized and characterized. Strong donation of nonbonding electrons on oxygen into the adjacent σ*(C-O(+)) orbital was predicted by modeling to result in unheard of carbon-oxygen bond lengths. The kinetic stability of the triquinane ring system provides a platform upon which to study these otherwise elusive species, which are evocative of intermediates on the acetalization reaction pathway. Crystallographic analysis of the α-hydroxy and α-methoxy oxatriquinane triflates reveals 1.658 and 1.619 Å C-O(+) bond lengths, respectively, the former of which is a new record for the C-O bond.

Spinal Cord Signal Intensity Predicts Functional Outcomes in the Operative Management of Degenerative Cervical Myelopathy.

STUDY DESIGN: Prospective single institutional cohort study on degenerative cervical myelopathy (DCM) from 2009 to 2022. OBJECTIVE: This study aims to assess the relationship among preoperative spinal cord signal change, postoperative signal change evolution, and functional outcome in patients undergoing surgery for DCM. SUMMARY OF BACKGROUND DATA: There is conflicting evidence on whether spinal cord signal intensity influences functional outcomes in patients with DCM. PATIENTS AND METHODS: This prospective study investigated 104 patients with DCM that underwent both preoperative and routine postoperative cervical spine magnetic resonance imaging (MRI) as part of a research protocol. Signal intensity/grade, modified Japanese Orthopedic Association (mJOA) scores, signal resolution, and patient demographics were assessed. RESULTS: Sixty-eight of the subjects were found to have abnormal T2 spinal cord signal intensity changes on their preoperative MRI. The total mean preoperative mJOA score was 13.6, increasing postoperatively to 16 (P < 0.001). The presence or absence of preoperative spinal cord signal change was not associated with the change in mJOA score or neurological recovery rate after surgery. Of the 68 patients with preoperative T2 signal change, 36 were found to have an improvement in the T2-weighted signal grade after surgery and 32 had no change in postoperative signal grade. The mean improvement in mJOA score (3.7) and neurological recovery rate (70.3%) was significantly higher in the patients with preoperative signal change whose postoperative MRI signal change grade improved by at least one point compared with those that did not (2.0, 50.5%), (P < 0.001, P < 0.003). CONCLUSIONS: The presence of preoperative T2-weighted signal change was associated with lower preoperative mJOA scores, but no change in mJOA after surgery or postoperative neurological recovery rate. However, improvement in T2-weighted spinal cord signal grade on postoperative MRI was significantly associated with a degree of neurological improvement after surgery.

Spondylolisthesis and mismatch deformity affect outcomes after total knee arthroplasty.

BACKGROUND: Little published data currently exist regarding the potential relationships between spondylolisthesis, mismatch deformity, and clinical outcomes following total knee arthroplasty (TKA). We hypothesize that preexisting spondylolisthesis will result in decreased functional outcomes after TKA. METHODS: This retrospective cohort comparison of 933 TKAs was performed between January 2017 and 2020. TKAs were excluded if they were not performed for primary osteoarthritis (OA) or if preoperative lumbar radiographs were unavailable/inadequate to measure the degree of spondylolisthesis. Ninety-five TKAs were subsequently available for inclusion and divided into two groups: those with spondylolisthesis and those without. Within the spondylolisthesis cohort, pelvic incidence (PI) and lumbar lordosis (LL) were calculated on lateral radiographs to determine the difference (PI-LL). Radiographs with PI-LL > 10° were then categorized as having mismatch deformity (MD). The following clinical outcomes were compared between the groups: need for manipulation under anesthesia (MUA), total postoperative arc of motion (AOM) both pre-MUA or post-MUA/revision, incidence of flexion contracture, and a need for later revision. RESULTS: Forty-nine TKAs met the spondylolisthesis criteria, while 44 did not have spondylolisthesis. There were no significant differences in gender, body mass index, preoperative knee range of motion (ROM), preoperative AOM, or opiate use between the groups. TKAs with spondylolisthesis and concomitant MD were more likely to have MUA (p = 0.016), ROM < 0-120 (p < 0.014), and a decreased AOM (p < 0.02) without interventions. CONCLUSION: Preexisting spondylolisthesis by itself may not have adverse effect clinical results following TKA. However, spondylolisthesis increases the likelihood of developing MD. In those with both spondylolisthesis and concomitant mismatch deformities, patients had statistically and clinically significantly decreased in postoperative ROM/AOM and increased need for MUA. Surgeons should consider clinical/radiographic assessments of patients with chronic back pain who present for total joint arthroplasty. LEVEL OF EVIDENCE: Level 3.

Biportal Endoscopic Approach for Lumbar Degenerative Disease in the Ambulatory Outpatient vs Inpatient Setting: A Comparative Study.

BACKGROUND: Biportal spinal endoscopy is increasingly utilized for lumbar disc herniations and lumbar stenosis. The objective was to investigate the safety and effectiveness of the technique in the outpatient vs inpatient setting. METHODS: This is a comparative study of consecutive patients who underwent biportal spinal endoscopy by a single surgeon at a single institution. Demographics, surgical complications, and patient-reported outcomes were prospectively collected and retrospectively analyzed. Statistics were calculated among treatment groups using unpaired t test and χ 2 analysis where appropriate. Statistical significance was determined as P < 0.05. RESULTS: Eighty-four patients were included, 58 (69.0%) as outpatient, 26 (31.0%) as inpatient. Mean follow-up was 7.5 months. Statistically significant differences in age, American Society of Anesthesiologists classification, and Charleston Comorbidity Index scores were reported between cohorts, with younger and healthier patients undergoing outpatient surgery (P < 0.0001). Outpatients were more likely to have discectomies while inpatients were more likely to have decompressions for stenosis. No significant differences in postoperative complications were found between groups.Both cohorts demonstrated significant improvement in visual analog scale (VAS) back and leg pain scores and Oswestry Disability Index scores (P < 0.001). Outpatients had significantly lower postoperative VAS back pain (P = 0.001) and Oswestry Disability Index scores (P = 0.004) at 5-8 weeks compared with inpatients, but there was no significant difference for VAS leg pain scores at all time points between the cohorts. CONCLUSIONS: Early results demonstrate that biportal spinal endoscopy can safely and effectively be performed in both inpatient and outpatient settings. CLINICAL RELEVANCE: Outpatient biportal spinal endoscopy can be performed successfully in well selected patients, which may reduce the financial burden of spine surgery to the U.S. healthcare system.

Development and External Validation of a Risk Calculator for Prediction of Major Complications and Readmission After Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: A retrospective, case-control study. OBJECTIVE: We aim to build a risk calculator predicting major perioperative complications after anterior cervical fusion. In addition, we aim to externally validate this calculator with an institutional cohort of patients who underwent anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: The average age and proportion of patients with at least one comorbidity undergoing ACDF have increased in recent years. Given the increased morbidity and cost associated with perioperative complications and unplanned readmission, accurate risk stratification of patients undergoing ACDF is of great clinical utility. METHODS: This is a retrospective cohort study of adults who underwent anterior cervical fusion at any nonfederal California hospital between 2015 and 2017. The primary outcome was major perioperative complication or 30-day readmission. We built standard and ensemble machine learning models for risk prediction, assessing discrimination, and calibration. The best-performing model was validated on an external cohort comprised of consecutive adult patients who underwent ACDF at our institution between 2013 and 2020. RESULTS: A total of 23,184 patients were included in this study; there were 1886 cases of major complication or readmissions. The ensemble model was well calibrated and demonstrated an area under the receiver operating characteristic curve of 0.728. The variables most important for the ensemble model include male sex, medical comorbidities, history of complications, and teaching hospital status. The ensemble model was evaluated on the validation cohort (n=260) with an area under the receiver operating characteristic curve of 0.802. The ensemble algorithm was used to build a web-based risk calculator. CONCLUSION: We report derivation and external validation of an ensemble algorithm for prediction of major perioperative complications and 30-day readmission after anterior cervical fusion. This model has excellent discrimination and is well calibrated when tested on a contemporaneous external cohort of ACDF cases.

A Systematic Review of the Effects of Second-Eye Cataract Surgery on Motor Function.

Cataract removal surgery is one of the most commonly performed surgical procedure in developed countries. The financial and staff resource cost that first-eye cataract surgery incurs, leads to restricted access to second-eye cataract surgery (SES) in some areas, including the United Kingdom. These restrictions have been imposed despite a lack of knowledge about the impact of not performing SES on visuo-motor function. To this end, a systematic literature review was carried out, with the aim of synthesising our present understanding of the effects of SES on motor function. Key terms were searched across four databases, PsycINFO, Medline, Web of Science, and CINAHL. Of the screened studies (K = 499) 13 met the eligibility criteria. The homogeneity between participants, study-design and outcome measures across these studies was not sufficient for meta-analyses and a narrative synthesis was carried out. The evidence from objective sources indicates a positive effect of SES on both mobility and fall rates, however, when considering self-report measures, the reduction in falls associated with SES becomes negligible. The evidence for any positive effect of SES on driving is also mixed, whereby SES was associated with improvements in simulated driving performance but was not associated with changes in driving behaviours measured through in vehicle monitoring. Self-report measures of driving performance also returned inconsistent results. Whilst SES appears to be associated with a general trend towards improved motor function, more evidence is needed to reach any firm conclusions and to best advise policy regarding access to SES in an ageing population. Systematic Review Registration: https://osf.io/7hne6/, identifier INPLASY2020100042.

Lumbar Spine Sagittal Mismatch Deformity Negatively Affects Total Knee Arthroplasty Outcomes.

There is currently a paucity of data regarding the potential relationships between preexisting spinal deformity and clinical outcomes following total knee arthroplasty (TKA). We sought to expand upon this deficit. We hypothesize that lumbar sagittal mismatch deformity (MD) will correlate with a decrease in functional outcomes after TKA. This retrospective cohort comparison of 933 TKAs was performed between January 2017 and 2020. TKAs were excluded if they were not performed for primary osteoarthritis (OA) or if preoperative lumbar radiographs were unavailable/inadequate to measure sagittal parameters of interest: pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, and deformity mismatch. Ninety-four TKAs were subsequently available for inclusion and divided into two groups: those with MD as defined by |PI-LL| > 10 degrees and those without MD. The following clinical outcomes were compared between the groups: total postoperative arc of motion (AOM), incidence of flexion contracture, and need for manipulation under anesthesia (MUA). In total, 53 TKAs met the MD criteria, while 41 did not have MD. There were no significant differences in demographics, body mass index, preoperative knee range of motion (ROM), preoperative AOM, or opiate use between the groups. TKAs with MD were more likely to have MUA (p = 0.026), ROM <0 to 120 (p < 0.001), a decreased AOM by 16 degrees (p < 0.001), and a flexion contracture postoperatively (p = 0.01). Preexisting MD may adversely affect clinical results following TKA. Statistically and clinically significant decreases in postoperative ROM/AOM, increased likelihood of flexion contracture, and increased need for MUA were all noted in those with MD. This is a Level 3 study.

National trends in the utilization of lumbar disc replacement for lumbar degenerative disc disease over a 10-year period, 2010 to 2019.

Background: Lumbar fusion (LF) is commonly performed to manage lumbar degenerative disc disease (LDDD) that has failed conservative measures. However, lumbar disc replacement (LDR) procedures are increasingly prevalent and designed to preserve motion in carefully selected patients. Methods: A retrospective cohort study was performed using the National Inpatient Sample (NIS), queried from 2010 to 2019 to identify patients undergoing single and double-level LF or LDR with a diagnosis of LDDD using International Classification of Diseases (ICD) 9th (ICD-9) and 10th (ICD-10) revision diagnostic and procedure codes. Propensity score matching (PSM) with a ratio of 2:1 was performed. All cost estimates reflect reported hospital costs adjusted to December 2019 United States Dollars. Results: A total of 1,129,121 LF cases (99.3%) and 8,049 LDR cases (0.7%) were identified, with 364,637 (32.3%) and 712 (8.8%) comprising two-level surgeries, respectively. 1,712 LDRs were performed in 2010 (1.27% of all), decreasing to 565 in 2013 (0.52%), and increased slightly to 870 in 2019 (0.74%). LDR patients were significantly more likely to be younger (mean age 41.2 vs. 57.1, P<0.001) and healthier (mean ECI 0.88 vs. 1.80, P<0.001). On matched analysis, LDR hospital costs were $4,529 less (P<0.001) and length of stay was 0.65 days shorter (P<0.001) than LF patients. LDR patients had lower rates of any complication (7.0% vs. 13.2%, P<0.001), neurologic complication (3.0% vs. 4.2%, P=0.006), and blood transfusion (3.1% vs. 8.1%, P<0.001) compared to LF patients. Conclusions: The prevalence of LDR procedures decreased from 2010-2017 but began to increase again in 2018 and 2019. Single-level LDR was associated with reduced costs and length of stay (LOS), and lower rates of blood transfusion compared to LF in patients with LDDD.

Intermittent and Transient Hypotension-related Anterior Cord Syndrome following Elective Cervical Spine Surgery: A Case Report.

INTRODUCTION: Anterior cord syndrome (ACS) is a type of incomplete spinal cord injury caused by either direct compression of the anterior spinal cord, or by ischemia of the anterior spinal artery. This phenomenon has neither been described transiently nor intraoperatively. CASE REPORT: We describe the case of a 61-year-old male who developed intermittent and transient anterior spinal cord syndrome secondary to hypotension related hypoperfusion of the anterior spinal artery after elective cervical spine surgery. Through close blood pressure monitoring and intensive care unit support, the patient regained full neurological recovery. CONCLUSION: Anterior spinal cord syndrome is a rare condition affecting the anterior 2/3 of the spinal cord, resulting in incomplete paralysis. Blood flow can be disrupted through the anterior spinal artery, either through thrombosis or hypotension. We describe our rare case so that surgeons may recognize this potentially devastating condition.

Drivers use active gaze to monitor waypoints during automated driving.

Automated vehicles (AVs) will change the role of the driver, from actively controlling the vehicle to primarily monitoring it. Removing the driver from the control loop could fundamentally change the way that drivers sample visual information from the scene, and in particular, alter the gaze patterns generated when under AV control. To better understand how automation affects gaze patterns this experiment used tightly controlled experimental conditions with a series of transitions from 'Manual' control to 'Automated' vehicle control. Automated trials were produced using either a 'Replay' of the driver's own steering trajectories or standard 'Stock' trials that were identical for all participants. Gaze patterns produced during Manual and Automated conditions were recorded and compared. Overall the gaze patterns across conditions were very similar, but detailed analysis shows that drivers looked slightly further ahead (increased gaze time headway) during Automation with only small differences between Stock and Replay trials. A novel mixture modelling method decomposed gaze patterns into two distinct categories and revealed that the gaze time headway increased during Automation. Further analyses revealed that while there was a general shift to look further ahead (and fixate the bend entry earlier) when under automated vehicle control, similar waypoint-tracking gaze patterns were produced during Manual driving and Automation. The consistency of gaze patterns across driving modes suggests that active-gaze models (developed for manual driving) might be useful for monitoring driver engagement during Automated driving, with deviations in gaze behaviour from what would be expected during manual control potentially indicating that a driver is not closely monitoring the automated system.

Accurate Reporting of Concomitant Procedures Is Highly Variable in Studies Investigating Knee Cartilage Restoration.

OBJECTIVE: Successful clinical outcomes following cartilage restoration procedures are highly dependent on addressing concomitant pathology. The purpose of this study was to document methods for evaluating concomitant procedures of the knee when performed with articular cartilage restoration techniques, and to review their reported findings in high-impact clinical orthopedic studies. We hypothesized that there are substantial inconsistencies in reporting clinical outcomes associated with concomitant procedures relative to outcomes related to isolated cartilage repair. DESIGN: A total of 133 clinical studies on articular cartilage repair of the knee were identified from 6 high-impact orthopedic journals between 2011 and 2017. Studies were included if they were primary research articles reporting clinical outcomes data following surgical treatment of articular cartilage lesions with a minimum sample size of 5 patients. Studies were excluded if they were review articles, meta-analyses, and articles reporting only nonclinical outcomes (e.g., imaging, histology). A full-text review was then used to evaluate details regarding study methodology and reporting on the following variables: primary cartilage repair procedure, and the utilization of concomitant procedures to address additional patient comorbidities, including malalignment, meniscus pathology, and ligamentous instability. Each study was additionally reviewed to document variation in clinical outcomes reporting in patients that had these comorbidities addressed at the time of surgery. RESULTS: All studies reported on the type of primary cartilage repair procedure, with autologous chondrocyte implantation (ACI) noted in 43% of studies, microfracture (MF) reported in 16.5%, osteochondral allograft (OCA) in 15%, and osteochondral autograft transplant (OAT) in 8.2%. Regarding concomitant pathology, anterior cruciate ligament (ACL) reconstruction (24.8%) and meniscus repair (23.3%) were the most commonly addressed patient comorbidities. A total of 56 studies (42.1%) excluded patients with malalignment, meniscus injury, and ligamentous instability. For studies that addressed concomitant pathology, 72.7% reported clinical outcomes separately from the cohort treated with only cartilage repair. A total of 16.5% of studies neither excluded nor addressed concomitant pathologies. There was a significant amount of variation in the patient reported outcome scores used among the studies, with the majority of studies reporting International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcomes Score (KOOS) in 47.2% and 43.6% of articles, respectively. CONCLUSIONS: In this study on knee cartilage restoration, recognition and management of concomitant pathology is inadequately reported in approximately 28% of studies. Only 30% of articles reported adequate treatment of concomitant ailments while scoring their outcomes using one of a potential 18 different scoring systems. These findings highlight the need for more standardized methods to be applied in future research with regard to inclusion, exclusion, and scoring concomitant pathologies with regard to treatment of cartilage defects in the knee.

Exploring the effects of degraded vision on sensorimotor performance.

PURPOSE: Many people experience unilateral degraded vision, usually owing to a developmental or age-related disorder. There are unresolved questions regarding the extent to which such unilateral visual deficits impact on sensorimotor performance; an important issue as sensorimotor limitations can constrain quality of life by restricting 'activities of daily living'. Examination of the relationship between visual deficit and sensorimotor performance is essential for determining the functional implications of ophthalmic conditions. This study attempts to explore the effect of unilaterally degraded vision on sensorimotor performance. METHODS: In Experiment 1 we simulated visual deficits in 30 participants using unilateral and bilateral Bangerter filters to explore whether motor performance was affected in water pouring, peg placing, and aiming tasks. Experiment 2 (n = 74) tested the hypothesis that kinematic measures are associated with visuomotor deficits by measuring the impact of small visual sensitivity decrements created by monocular viewing on sensorimotor interactions with targets presented on a planar surface in aiming, tracking and steering tasks. RESULTS: In Experiment 1, the filters caused decreased task performance-confirming that unilateral (and bilateral) visual loss has functional implications. In Experiment 2, kinematic measures were affected by monocular viewing in two of three tasks requiring rapid online visual feedback (aiming and steering). CONCLUSIONS: Unilateral visual loss has a measurable impact on sensorimotor performance. The benefits of binocular vision may be particularly important for some groups (e.g. older adults) where an inability to complete sensorimotor tasks may necessitate assisted living. There is an urgent need to develop rigorous kinematic approaches to the quantification of the functional impact of unilaterally degraded vision and of the benefits associated with treatments for unilateral ophthalmic conditions to enable informed decisions around treatment.

Severity and location of lumbar spine stenosis affects the outcome of total knee arthroplasty.

BACKGROUND: Recent studies have noted that patients with pre-existing lumbar spinal stenosis (LSS) have lower functional outcomes after total knee arthroplasty (TKA). Given that LSS manifests heterogeneously in location and severity, its influence on knee replacement merits a radiographically targeted analysis. We hypothesize that patients with more severe LSS will have diminished knee mobility before and after TKA. METHODS: This retrospective case series assessed all TKAs performed at our institution for primary osteoarthritis from 2017-2020. Preoperative lumbar magnetic resonance image (MRI) with no prior lumbar spine surgery was necessary for inclusion. Stenosis severity was demonstrated by (1) anterior-posterior (AP) diameter of the thecal sac and (2) morphological grade. TKA outcomes in 103 cases (94 patients) were assessed by measuring preoperative and postoperative arc of motion (AOM), postoperative flexion contracture, and need for manipulation under anesthesia. RESULTS: Patients with mild stenosis did significantly better in terms of postoperative knee AOM. As AP diameter decreased at levels L1-2, L2-3, L3-4, and L4-5, there was a significant reduction in preoperative-AOM (p < 0.001 for each), with a 16 degree decrease when using patients' most stenotic level (p < 0.001). The same was noted with respect to increased morphological grade (p < 0.001), with a 5 degree decrease for patients' most stenotic level (p < 0.001). CONCLUSION: Severe LSS, which is readily demonstrated by a reduction in the AP diameter of the thecal sac or increased morphological grade on MRI, correlated with a significant reduction in preoperative AOM that was not improved after TKA. Persistent postoperative reductions in AOM may contribute to reduced patient satisfaction and recovery. LEVEL OF EVIDENCE: Level 4.

Spinal Cord Drift Following Laminoplasty Versus Laminectomy and Fusion for Cervical Spondylotic Myelopathy.

BACKGROUND: Cervical laminoplasty and laminectomy and fusion (LF) are posterior-based surgical techniques for the surgical treatment of cervical spondylotic myelopathy (CSM). Interestingly, the comparative amount of spinal cord drift obtained from these procedures has not been extensively described. The purpose of this study is to compare spinal cord drift between cervical laminoplasty and LF in patients with CSM. METHODS: The laminoplasty group consisted of 22 patients, and the LF group consisted of 44 patients. Preoperative and postoperative alignment was measured using the Cobb angle (C2-C7). Spinal cord position was measured on axial T2-magnetic resonance imaging of the cervical spine preoperatively and postoperatively. Spinal cord drift was quantified by subtracting preoperative values from postoperative values. Functional improvement was assessed using the modified Japanese Orthopaedic Association (mJOA) score. RESULTS: Mean spinal cord drift was higher following LF compared to laminoplasty (2.70 vs 1.71 mm, P < .01). Using logistic regression analysis, there was no correlation between sagittal alignment and spinal cord drift. Both groups showed an improvement in mJOA scores postoperatively compared to their preoperative values (laminoplasty, +2.0, P = .012; LF, +2.4, P < .01). However, there was no difference in mJOA score improvement postoperatively between both groups (P = .482). CONCLUSIONS: This study demonstrates that patients who had LF for CSM achieved more spinal cord drift postoperatively compared to those who had laminoplasty. However, the increased drift did not translate into superior functional outcome as measured by the mJOA score. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: Spinal cord drift following LF may differ from laminoplasty in patients undergoing surgery for CSM. This finding should be considered when assessing CSM patients for surgical intervention.

Updated external validation of the SORG machine learning algorithms for prediction of ninety-day and one-year mortality after surgery for spinal metastasis.

BACKGROUND CONTEXT: Surgical decompression and stabilization in the setting of spinal metastasis is performed to relieve pain and preserve functional status. These potential benefits must be weighed against the risks of perioperative morbidity and mortality. Accurate prediction of a patient's postoperative survival is a crucial component of patient counseling. PURPOSE: To externally validate the SORG machine learning algorithms for prediction of 90-day and 1-year mortality after surgery for spinal metastasis. STUDY DESIGN/SETTING: Retrospective, cohort study PATIENT SAMPLE: Patients 18 years or older at a tertiary care medical center treated surgically for spinal metastasis OUTCOME MEASURES: Mortality within 90 days of surgery, mortality within 1 year of surgery METHODS: This is a retrospective cohort study of 298 adult patients at a tertiary care medical center treated surgically for spinal metastasis between 2004 and 2020. Baseline characteristics of the validation cohort were compared to the derivation cohort for the SORG algorithms. The following metrics were used to assess the performance of the algorithms: discrimination, calibration, overall model performance, and decision curve analysis. RESULTS: Sixty-one patients died within 90 days of surgery and 133 died within 1 year of surgery. The validation cohort differed significantly from the derivation cohort. The SORG algorithms for 90-day mortality and 1-year mortality performed excellently with respect to discrimination; the algorithm for 1-year mortality was well-calibrated. At both postoperative time points, the SORG algorithms showed greater net benefit than the default strategies of changing management for no patients or for all patients. CONCLUSIONS: With an independent, contemporary, and geographically distinct population, we report successful external validation of SORG algorithms for preoperative risk prediction of 90-day and 1-year mortality after surgery for spinal metastasis. By providing accurate prediction of intermediate and long-term mortality risk, these externally validated algorithms may inform shared decision-making with patients in determining management of spinal metastatic disease.