Zachary Ries

Natural history of spinopelvic alignment differs from symptomatic deformity of the spine.

Study Design. Cross-sectional study and systematic review of the literature. Objective. Describe the natural history of spinopelvic alignment parameters and their behavior in patients with degenerative spinal deformity. Summary of Background Data. Normal stance and gait requires congruence between the spine-sacrum and pelvis-lower extremities. This is determined by the pelvic incidence (PI), and 2 positional parameters, the pelvic tilt, and sacral slope (SS). The PI also affects lumbar lordosis (LL), a positional parameter. The final goal is to position the bodys axis of gravity to minimize muscle activity and energy consumption. Methods. Two study cohorts were recruited: 32 healthy teenagers (Risser IV-V) and 54 adult patients with symptomatic spinal deformity. Standing radiographs were used to measure spinopelvic alignment and positional parameters (SS, PI, sacral-femoral distance [SFD], C7-plumbline [C7P], LL, and thoracic kyphosis). Data from comparable groups of asymptomatic individuals were obtained from the literature. Results. PI increases linearly with age (r2 = 0.8646) and is paralleled by increasing SFD (r2 = 0.8531) but not by SS. Patients with symptomatic deformity have higher SFD (42 ± 13.6 mm vs. 63.6 ± 21.6 mm; P < 0.001) and lower SS (42° ± 9.6° vs. 30.7° ± 13.6°; P < 0.001) but unchanged PI. The C7P also presents a linear increase throughout life (r2 = 0.8931), and is significantly increased in patients with symptomatic deformity (40 ± 37 mm vs. 70.3 ± 59.5 mm; P < 0.001). Conclusion. First, Gradual increase in PI is described throughout the lifespan that is paralleled by an increase in SFD, and is not by an increase in the SS. This represents a morphologic change of the pelvis. Second, Patients with symptomatic deformity of the spine present an increased C7P, thoracic hypokyphosis, reduced LL, and signs of pelvic retroversion (decreased LL and SS; increased SFD).

Incidence, Risk Factors, and Causes for Thirty-Day Unplanned Readmissions Following Primary Lower-Extremity Amputation in Patients with Diabetes

BACKGROUND The Centers for Medicare & Medicaid Services targeted thirty-day readmissions as a quality-of-care measure. Hospitals can be penalized on unplanned readmissions. Given the frequency of amputation in diabetic patients and our changing health-care system, the purpose of this study was to determine the incidence, risk factors, and causes for unplanned thirty-day readmissions following primary lower-extremity amputation in diabetic patients. METHODS Patients with a diagnosis of diabetes undergoing primary lower-extremity amputation between 2002 and 2013 were retrospectively identified in a single-center patient database. Chart review determined patient factors including comorbidities, hemoglobin A1c level, amputation level, and demographic characteristics. Patients were divided into groups with and without unplanned readmission within thirty days postoperatively. Univariate and multivariate logistic regression analyses were used to compare cohorts and to identify variables associated with readmission. RESULTS Overall, forty-six (10.5%) of 439 diabetic patients undergoing primary lower-extremity amputation had an unplanned thirty-day readmission. The top reason for readmission was a major surgical event requiring reoperation (37.0%), followed by medical events (28.3%) and minor surgical events (28.3%). In the univariate analysis, discharge on antibiotics (p = 0.002), smoking (p = 0.003), chronic kidney disease (p = 0.002), peripheral vascular disease (p = 0.002), and higher Charlson Comorbidity Index (p = 0.001) were each associated with readmission. In the multivariate analysis, diagnosis of gangrene (odds ratio [OR], 2.95 [95% confidence interval (95% CI), 1.37 to 6.35]), discharge on antibiotics (OR, 4.48 [95% CI, 1.71 to 11.74]), smoking (OR, 3.22 [95% CI, 1.40 to 7.36]), chronic kidney disease (OR, 2.82 [95% CI, 1.30 to 6.15]), and peripheral vascular disease (OR, 2.47 [95% CI, 1.08 to 5.67]) were independently associated with readmission. CONCLUSIONS Thirty-day readmission rates following primary lower-extremity amputation in patients with diabetes were high at >10%. Both medical and surgical complications, many of which were unavoidable, contributed to readmission. Quality-reporting metrics should include these risk factors to avoid undeservedly penalizing surgeons and hospitals caring for this patient population. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Causes and Predictors of 30-Day Readmission After Shoulder and Knee Arthroscopy: An Analysis of 15,167 Cases

PURPOSE To evaluate the incidence, causes, and risk factors for unplanned 30-day readmission after shoulder and knee arthroscopy. METHODS A multicenter, prospective clinic registry, the American College of Surgeons National Surgical Quality Improvement Program, was queried for Current Procedural Terminology codes representing the most common shoulder and knee arthroscopic procedures. Unplanned readmissions within 30 days were evaluated dichotomously, and causes of readmission were identified. Univariate and multivariate logistic regression analyses were used to identify variables predictive of readmission. RESULTS In total, we identified 15,167 patients who underwent shoulder and knee arthroscopic procedures in 2012. Overall, 136 (0.90%) were readmitted within 30 days, and the rates were similar after shoulder (0.86%) and knee (0.92%) procedures. Readmissions were most common after arthroscopic debridement of the knee (1.56%) and lowest after rotator cuff and labral repairs (0.68%) and cruciate reconstructions (0.78%). The most common causes of readmission were surgical-site infections (37.1%), deep venous thrombosis and pulmonary embolism (17.1%), and postoperative pain (7.1%). Multivariate analysis identified age older than 80 years (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.5 to 8.1), chronic steroid use (OR, 3.3; 95% CI, 1.5 to 7.2), and elevated American Society of Anesthesiologists class (OR, 4.2; 95% CI, 1.4 to 12.0) as independent risk factors for readmission. CONCLUSIONS The rate of unplanned readmissions within 30 days of shoulder and knee arthroscopic procedures is low, at 0.92%, with wound-related complications being the most common cause. In patients with advanced age, with chronic steroid use, and with chronic systemic disease, the risk of readmission may be higher. These findings may aid in the informed-consent process, patient optimization, and the quality-reporting risk-adjustment process. LEVEL OF EVIDENCE Level III, prognostic study.

Far cortical locking technology for fixation of periprosthetic distal femur fractures: a surgical technique.

Far cortical locking screws have been shown to form greater amounts of callus in ovine studies when compared to traditional locking plates. These screws have recently become available for clinical use. This article describes the indications and surgical technique for far cortical locking screws, with a focus on distal femur periprosthetic fractures.

Selective Thoracic Fusion of Lenke I and II Curves Affects Sagittal Profiles But Not Sagittal or Spinopelvic Alignment: A Case-Control Study.

Study Design. Literature review and retrospective case-control study (level 3 evidence) examining 50 adolescent idiopathic scoliosis (AIS) (Lenke I or II curve) cases with 32 healthy controls of the same age. The sagittal profiles were measured preoperatively, 6 months, and 2 years after surgery and compared with those of age-matched controls at baseline. Objective. The purpose of this study is to compare baseline sagittal profiles of AIS Lenke I and II curves with age-matched healthy controls and at 6 months and 2 years after surgery, as well as with previously published reports. Summary of Background Data. Sagittal alignment and profiles have gained significant attention in spinal deformity outcomes. The sagittal profile of patients with AIS has been previously reported, as well as the effects of surgical correction, with inconsistent results and no clear references to nonscoliotic controls. Methods. Baseline sagittal profiles of 50 patients presenting with Lenke I or II AIS curves treated with selective thoracic fusion were compared with 32 age-matched controls without spinal pathology. These values were also measured at 6 months and 2 years postoperatively to examine effects of selective thoracic fusion over time. Sagittal parameters examined include pelvic incidence, pelvic tilt, C7 plumb line (sagittal vertical alignment), thoracic kyphosis, and lumbar lordosis. A literature review was performed comparing previously published data. Data are presented as mean (95% confidence interval). P value of less than 0.05 was considered significant. Results. Interobserver reliability (Cohen &kgr;= 0.49–0.95). All demographic and preoperative sagittal alignment parameters were comparable between controls and patients with AIS prior to surgery. After selective thoracic fusion, thoracic kyphosis decreased significantly from baseline (25.4º [21.6–29.2] vs. 15.3º [12.8–17.8]; P < 0.001) at 6 months and at 2 years (10.3º [7.5–13.1]; P < 0.001). The lumbar lordosis significantly decreased at 6 months from baseline (54.5º [28.6–80.5] vs. 61.8º (33.4–90.1); P < 0.001) and at 2 years (55.4º [29.0–81.9]; P < 0.001). Sagittal vertical alignment, pelvic tilt, and pelvic incidence were comparable between controls and patients with AIS at baseline and did not change with surgery. Conclusions. Adolescents with Lenke I or II curves have comparable sagittal profiles with those of healthy controls of the same age. This suggests that Lenke I and II curves may not be hypokyphotic as previously thought. After selective thoracic fusion, patients with AIS have a significantly decreased thoracic kyphosis, which is accompanied by reciprocal changes in the noninstrumented lumbar curve. Sagittal vertical alignment and pelvic tilt are not significantly affected. These results agree with previous reports, which suggest that constructs with pedicle screws have a higher impact on sagittal curves but do not affect sagittal or spinopelvic alignment. The long-term effects of abnormal sagittal profiles need further clarification. Level of Evidence: 3

Patellofemoral Instability in Active Adolescents.

Patellofemoral instability is a common problem in the adolescent population. Patellar stability depends on a dynamic interplay between bony and soft tissue restraints. Several pathoanatomical factors increase the likelihood of patellar instability: patella alta, trochlear dysplasia, malalignment, and deficient proximal medial restraints. Treatment for first-time patella dislocations is typically nonoperative and includes bracing, early range of motion, and physical therapy. The only absolute indication for early surgery is a large osteochondral fragment that can be fixed. Surgical stabilization is indicated for chronic patellar instability and includes both proximal and distal realignment options. Medial patellofemoral ligament reconstruction is the treatment of choice in most adolescent patients with patella instability. Distal bony realignment procedures are reserved for skeletally mature adolescents.

Curve Characteristics and Foraminal Dimensions in Patients with Adult Scoliosis and Radiculopathy.

Study Design: Retrospective cohort study. Objective: To demonstrate a correlation between radiculopathy symptoms, foraminal morphology, and curve types. Summary of Background Data: Patients with degenerative scoliosis frequently present with foraminal stenosis and radiculopathy, the origin of which is not well understood. Methods: A total of 48 patients (384 foraminas) were included: 14 with low back pain (B); 16 with femoral nerve pain (F); and 18 with sciatic nerve pain (S). The symptomatic foramen of groups F and S were compared with asymptomatic foramina. Alignment was measured from standardized radiographs; 3D-CT reconstructions were used to measure foraminal height and area. Data are presented as mean±SD. The &khgr;2, t test, and Pearson coefficients were calculated; as well as interobserver and intraobserver reproducibility (Cohen &kgr;). Results: Seventeen of the 18 patients with sciatic nerve pain (S) presented foraminal stenosis (<40 mm2) at the concavity of the fractional curve distal to the main lumbar structural curve. The symptomatic foramina were significantly smaller in height (7.8±2.5 vs. 12.1±3.1 mm, P<0.0001) and area (30.1±14.3 vs. 57.6±28.7 mm2, P<0.0001) compared with asymptomatic foramen; 7/7 patients with femoral nerve pain (F) and lumbar structural curves (apex L3 or lower) had foraminal stenosis at the concavity of the fractional curve. Eight of the 9 patients with femoral nerve pain (F) and thoracic, thoracolumbar, or lumbar (apex L2 or higher) curves, presented foraminal stenosis in the concavity of the caudal fractional curve. The symptomatic foraminal spaces were significantly smaller in height (9.2±3.2 vs. 12.1±3.1 mm, P<0.0001) and area (30.1±15.2 vs. 57.6±28.7 mm2, P<0.0001). Foraminal height correlated with foraminal area (r=0.68–0.85; P<0.0001). Interobserver agreement was between 0.6092 and 0.8679. Conclusions: A correlation between curve types and symptomatic foraminal stenosis exists. Adult scoliosis patients with sciatic nerve pain typically present with foraminal stenosis at the concavity of the caudal fractional curve. Similarly, patients with femoral nerve pain present with foraminal stenosis at the concavity of the caudal fractional curve when the main structural curve is thoracic, thoracolumbar, or lumbar (apex L2 or higher).