Following exocytosis, the rate of recovery of neurotransmitter release is determined by vesicle retrieval from the plasma membrane and by recruitment of vesicles from reserve pools within the synapse, the latter of which is dependent on mitochondrial ATP. The Bcl-2 family protein Bcl-xL, in addition to its role in cell death, regulates neurotransmitter release and recovery in part by increasing ATP availability from mitochondria. We now find, however, that, Bcl-xL directly regulates endocytotic vesicle retrieval in hippocampal neurons through protein/protein interaction with components of the clathrin complex. Our evidence suggests that, during synaptic stimulation, Bcl-xL translocates to clathrin-coated pits in a calmodulin-dependent manner and forms a complex of proteins with the GTPase Drp1, Mff and clathrin. Depletion of Drp1 produces misformed endocytotic vesicles. Mutagenesis studies suggest that formation of the Bcl-xL-Drp1 complex is necessary for the enhanced rate of vesicle endocytosis produced by Bcl-xL, thus providing a mechanism for presynaptic plasticity.

The aims of this study are (i) to report on the rates of subsequent surgery following hip arthroscopy and (ii) to identify prognostic variables associated with revision surgery, survival rates and complication rates. The Statewide Planning and Research Cooperative System database, a census of hospital admissions and ambulatory surgery in New York State, was used to identify cases of primary hip arthroscopy. Demographic information and rates of subsequent revision hip arthroscopy or arthroplasty were collected. The risks were modeled with use of age, sex, procedure and surgeon volume as risk factors. Survival analyses were also performed, and 30-day complication was recorded. We identified 8267 procedures in 7836 patients from 1998 to 2012. Revision surgery occurred in 1087 cases (13.2%) at a mean of 1.7 ± 1.6 (mean ± SD) years. Revision arthroscopy accounted for 311 cases (3.8%), and arthroplasty for 796 (9.7%) cases. Survival analysis showed a 2-year survival rate of 88.1%, 5-year of 80.7% and 10-year of 74.9%. Regression analysis revealed that age >50 years [hazard ratio (HR) 2.09; confidence interval (CI) 1.82–2.39, P < 0.01] and a diagnosis of osteoarthritis (HR 2.72; CI 2.21–3.34, P < 0.01) were associated with increased risk of re-operation. Labral repair was associated with a lower risk of re-operation (HR 0.71; CI 0.54–0.93, P = 0.01). Finally, higher surgeon volume (>164 cases/year) resulted in a lower risk of re-operation versus lower volume (<102 cases/year) (HR 0.42; CI 0.32–0.54, P < 0.01). The 30-day complication rate was 0.2%. Older age and pre-existing osteoarthritis increased the likelihood of re-operation following hip arthroscopy, whereas performing a labral repair and having the procedure performed by a higher-volume surgeon lowered the risk of re-operation.

The learning curve for hip arthroscopy was unexpectedly demanding. Cases performed by surgeons with career volumes ≥519 had significantly lower risk of subsequent hip surgery than those performed by lower-volume surgeons.

Background The multiple-ligament-injured knee represents a special challenge, being an uncommon injury that is both severe and complicated to treat. Many studies have evaluated patients treated for this injury, but most are limited in their scope. The evaluation of this injury and its treatment using an administrative database might provide a different perspective.Questions/purposes Using a large administrative database, we determined (1) the number of multiligament knee reconstructions in New York State, (2) the rate of 90-day hospital readmission, and (3) the frequency of subsequent knee surgery. We examined the rates of these outcomes as a function of diagnosis, admission type, discharge status, comorbidity burden, and patient demographic factors. Methods We used the New York Department of Health Statewide Planning and Research Cooperative System (SPARCS), a database with information on patient characteristics, diagnoses, and treatments, to identify patients who underwent a multiligament procedure in a nonfederal facility from 1997 to 2005 using ICD-9-CM and Current Procedural Terminology codes. SPARCS collects data from all nonfederal acute care facilities, with an estimated reporting completeness of almost 99% for the years in this study. We evaluated data on patient age, sex, admission type, discharge status, and comorbidity burden (using Elixhauser comorbidities) and developed a multivariable logistic regression model to assess the influence of confounding variables. Results We identified 1032 patients in this database who underwent multiligament knee reconstruction in New York State from 1997 to 2005. The frequency of readmission within 90 days was 4.8% (n = 49). Readmission was more likely for patients who underwent inpatient multiligament reconstruction (odds ratio [OR] = 2.3; 95% CI: 1.2-4.4; p = 0.014), had a diagnosis of dislocation (OR = 2.2; 95% CI: 1.2-3.9; p = 0.011), or had various Elixhauser comorbidities, including chronic lung disease (OR = 6.4; 95% CI: 1.5-27.2; p = 0.013), fluid and electrolyte disorders (OR = 19.7; 95% CI: 2.5-155.7; p = 0.005), and anemia deficiency (OR = 5.6; 95% CI: 1.05-29.4; p = 0.044). Two hundred eighty-seven patients (28%) underwent subsequent knee surgery between their index

Hip arthroscopy is widely utilized to treat femoroacetabular impingement syndrome (FAIS). In order to evaluate the postoperative clinical and functional outcomes at 2-year follow up in patients with and without benign joint hypermobility syndrome following hip arthroscopy with capsular plication for FAIS, consecutive female patients with generalized ligamentous laxity undergoing primary hip arthroscopy with complete T-capsulotomy closure via plication for FAIS were prospectively identified. Patients were matched in a 4:1 ratio based on Beighton-Horan joint mobility index (BHJMI) then classified into no generalized joint laxity (NGJL, Score<4) or generalized joint laxity cohort (GJL, Score=4). Patient and surgical-related factors were analyzed using univariate and paired analysis with statistical significance set at a = 0.05. A total of 125 female patients were included in the study: 25 generalized joint laxity (GJL) patients and 100 matched to age, sex and BMI (NGJL cohort). The results demonstrated that there were no significant differences between demographics, preoperative range of motion, or radiographic analysis on univariate analysis. There was no statistical difference in postoperative range of motion between groups, though both groups demonstrated significant increases in postoperative flexion and postoperative internal rotation following hip arthroscopy. Paired analysis demonstrated no significant difference in HOS-SS, HOS-ADL, mHHS or VAS-pain, while GJL patients reported significantly greater patient satisfaction score at 2-years follow-up (p=0.007). In summary, hip arthroscopy with capsular plication is a highly effective treatment for FAIS in patients with and without generalized joint laxity. In our analysis, patients with and without generalized joint laxity demonstrated statistically similar and significant improvement in outcomes.

This study highlights the importance of attending surgeons being very clear and specific with regard to their physical therapy instructions to patients and therapists.

Periprosthetic osteolysis is a common occurrence after total ankle arthroplasty (TAA) and poses many challenges for the foot and ankle surgeon. Osteolysis may be asymptomatic and remain benign, or it may lead to component instability and require revision or arthrodesis. In this article, we present a current and comprehensive review of osteolysis in TAA with illustrative cases. We examine the basic science principles behind the etiology of osteolysis, discuss the workup of a patient with suspected osteolysis, and present a review of the evidence of various management strategies, including grafting of cysts, revision TAA, and arthrodesis. Level of Evidence: Level V, expert opinion.

Background Time between injury and ACL reconstruction (ACLR) may influence baseline knee-related and general-health related patient-reported outcome measures (PROMs). Despite the common use of PROMs as main outcomes in clinical studies, this has never been evaluated. Hypothesis/Purpose To determine whether time from injury to ACLR influences: (1) baseline PROMs; (2) pattern and prevalence of concurrent articular cartilage and meniscal injury. Study design Cross-sectional (level III). Methods 1,192 patients from the MOON consortium who underwent primary ACLR were eligible. ‘Acute’ ACLR was defined as <3 months (n=853; 72%), and ‘chronic’ as >6 months (n=339; 28%) from injury. Patient demographic, surgical characteristics (articular cartilage injury, medial [MM] and lateral [LM] meniscal tears), and baseline PROMs (Marx activity scale, IKDC, KOOS, SF-36) were collected. To determine whether time from injury to ACLR influences: (1) baseline PROMs; (2) pattern and prevalence of concurrent articular cartilage and meniscal injury. Analysis of covariance models were used to adjust for confounders on baseline outcome scores (age, sex, body mass index [BMI], smoking status, competition level, education). Results The median age was 23 years (IQR 17–35), n=530 (45%) were female, and median BMI was 25.0 kg/m2 (IQR 22.3–27.9); however, the chronic group was older, had higher BMI and fewer collegiate athletes. A significantly greater number of partial LM tears were seen acutely (14% vs. 6%; p<0.001), but more meniscal tears overall (74% vs 63%; p=0.001), complete MM tears (49% vs. 23%; p<0.001), and articular cartilage injury (54% vs. 33%; p<0.001) chronically. After controlling for confounders, chronic ACLR patients reported significantly lower baseline Marx (7.8 vs. 12.1, p<0.001), but higher baseline IKDC, physical function SF-36, and all KOOS subscales except quality of life (QoL). However, only the sports and recreation subscale exceeded the minimum clinically importance difference of 8 points (62.3 vs. 48.3; p<0.001). Conclusion After controlling for age, sex, competition level, smoking and BMI, chronic ACLR patients participated in less pivoting and cutting sports, but reported better pain/function. Whether decreased activity is deliberate after ACL injury, or these are simply less active patients who may be treated successfully without surgery warrants further investigation. Non-randomized studies that utilize PROMs should consider time from injury in design and data interpretation.