Amir Khoshbin

Epidemiology of Primary Anterior Shoulder Dislocation Requiring Closed Reduction in Ontario, Canada

Background: There is a lack of high-quality population-based literature describing the epidemiology of primary anterior shoulder dislocation. Purpose: To (1) calculate the incidence density rate (IDR) of primary anterior shoulder dislocation requiring closed reduction (CR; “index event”) in the general population and demographic subgroups, and (2) determine the rate of and risk factors for repeat shoulder CR. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: All patients who underwent shoulder CR by a physician in Ontario between April 2002 and September 2010 were identified with administrative databases. Exclusion criteria included age <16 and >70 years, posterior dislocation, and prior shoulder dislocation or surgery. Index event IDR was calculated for all populations/subgroups, and IDR comparisons were made. Repeat shoulder CR was sought until September 2012. Risk factors for repeat shoulder CR were identified with a Prentice, Williams, and Peterson proportional hazards model. Results: There were 20,719 persons (median age, 35 years; 74.3% male) who underwent a shoulder CR after a primary anterior shoulder dislocation (23.1/100,000 person-years). The IDR was highest among young males (98.3/100,000 person-years). A total of 3940 (19%) patients underwent repeat shoulder CR after a median of 0.9 years, of which 41.7% were ≤20 years of age. Less than two-thirds of all first repeat shoulder CR events occurred within 2 years; in fact, 95% occurred within 5 years. The risk of repeat shoulder CR was lowest if the primary reduction had been performed by an orthopaedic surgeon (hazard ratio [HR], 0.76; 95% CI: 0.64, 0.90; P = .002) or was associated with a humeral tuberosity fracture (HR, 0.71; CI, 0.53, 0.95; P = .02). Older age (HR, 0.97; CI, 0.97, 0.98; P < .0001) and higher medical comorbidity score (HR, 0.92; CI, 0.87, 0.98; P = .009) were also protective. Risk was highest among males (HR, 1.26; CI, 1.16, 1.36; P < .0001) and patients from low-income neighborhoods (HR, 1.23; CI, 1.13, 1.34; P < .0001). Conclusion: Young male patients have the highest incidence of primary anterior shoulder dislocation requiring CR and the greatest risk of repeat shoulder CR. Patient, provider, and injury factors all influence repeat shoulder CR risk. A comprehensive understanding of the epidemiology of primary anterior shoulder dislocation will aid management decisions and injury prevention initiatives.

Risk Factors for Recurrent Anterior Cruciate Ligament Reconstruction

Background: Anterior cruciate ligament reconstruction (ACLR) is routinely performed for symptomatic instability. Although it is a common procedure, there remain differences in surgical technique. Hospital administrative records in a public health care system were used to investigate the effect of patient, provider, and surgical factors on the risk of revision ACLR. Purpose: To define the rate and risk factors for ACL reoperation in Ontario, Canada, including both ipsilateral revision and contralateral primary procedures. Study Design: Cohort study; Level of evidence, 3. Methods: All primary elective ACLR procedures performed in Ontario (July 2003 to March 2008) in patients aged 15 to 60 years were identified via physician billing and hospital databases. Revision and contralateral ACLR were sought until January 2012. Patient factors (age, sex, comorbidity, income quintile, length of index hospital admission), provider factors (surgeon volume, academic hospital status), and surgical factors (allograft vs autograft; fixation type [screw, button, staple]; concomitant operative procedures) were used as covariates in a Cox proportional hazards survivorship model to generate hazard ratios (HRs) with confidence intervals (CIs) (α = .05). Kaplan-Meier survivorship curves with ACL revision as the end point were generated. Results: A total of 12,967 ACLR procedures with a mean follow-up of 5.2 years were eligible for study using preset criteria. The revision rate was 2.6% (mean ± SD, 2.91 ± 1.71 years to revision). The rate of primary contralateral ACLR was 4.6% (mean, 2.95 ± 1.81 years). In the Cox model, younger age (15-19 years) (HR, 2.1; 95% CI, 1.5-2.9; P < .001), ACLR performed at an academic hospital (HR, 1.6; 95% CI, 1.2-2.1; P < .001), and the use of allograft (HR, 1.7; 95% CI, 1.1-2.6; P = .02) significantly increased the risk of revision ACLR. Only younger age (HR, 2.1; 95% CI, 1.6-2.7; P < .001) was associated with an increased risk of contralateral ACLR. Conclusion: Contralateral ACLR was more frequent than revision ACLR in this population, while both surgical procedures were most common in patients younger than 20 years. Academic hospital status, but not surgeon volume, as well as the use of allograft also increased the risk for revision ACLR.

Risk factors for Recurrent Anterior Cruciate Ligament Reconstruction: A Population Study in Ontario, Canada with 5-year Follow-up.

Objectives: Anterior cruciate ligament reconstruction (ACLR) is routinely performed to treat symptomatic instability. Despite being a common procedure, significant variation persists in technique and graft choice. How patient, provider and surgical factors influence the risk of revision or contralateral primary ACLR has not been investigated using administrative data. The goal of our study was to define the rate and risk factors for ACL re-operation in Ontario. Methods: All primary elective ACLR performed in Ontario, Canada from July 2003 to March 2008 in patients aged 15 to 60 years were identified via billing, diagnosis and procedural databases. The main outcomes were revision and contralateral ACLR, sought until January 2012. Patient factors (age, gender, co-morbidity, income quintile, and length of index hospital admission), provider factors (surgeon volume, academic hospital status) and surgical factors (allograft vs. autograft; fixation: screw, button, staple; concomitant operative procedures) were used as covariates in a Cox Proportional Hazards survivorship model to generate Hazard Ratios (HR) with confidence intervals (alpha 0.05). Kaplan-Meier survivorship curves to revision were generated. Results: A total of 12,967 ACLR with a mean follow-up of 5.2 years were identified. The revision rate was 2.6% [after a median 2.72 years (interquartile range 1.38, 4.11)]. The rate of primary contralateral ACLR was 4.6% [after a median 2.71 years (interquartile range 1.49, 4.22)]. In the Cox model, younger age [15-19 years; HR=2.1 (95% CI: 1.5-2.9), p<0.001], ACLR performed at an academic hospital [HR=1.6 (95% CI: 1.2-2.1), p<0.001] and the use of allograft [HR=1.7 (95% CI: 1.1-2.6), p=0.02] significantly increased the risk of revision ACLR. The K-M curves to revision ACLR for allograft and autograft demonstrated equivalent survivorship for approximately 3 years, after which allograft ACLR were more commonly revised (Figure 1). Only younger age [15-19 years; HR=2.1, (95% CI: 1.6-2.7), p<0.001] was associated with an increased risk of contralateral ACLR. Conclusion: Contralateral ACLR was more frequent than revision ACLR in this population, while both re-operations were significantly more common in patients <20 years old. Academic hospital status but not surgeon volume, and the use of allograft also increased the risk of revision ACLR. Late failure of allograft ACLR is a novel finding.

Long-Term Functional Outcomes of Resected Tarsal Coalitions:

Background: There are few long-term studies evaluating tarsal coalition resections. The purpose of this study was to compare patient outcomes following resection of calcaneonavicular (CN) and talocalcaneal (TC) bars and to determine the relationship between the extent of a coalition and the outcome of resection. Methods: Patients younger than 18 years receiving resection for symptomatic tarsal coalition (1991-2004 inclusive) were eligible to participate. Follow-up evaluation included clinical examination to assess range of motion and self-reported functional outcome questionnaires. Two validated functional scales were used: the American Academy of Orthopaedic Surgeons (AAOS) Foot and Ankle Module, and the Foot Function Index (FFI). Twenty-four patients with 32 tarsal coalition resections (19 CN and 13 TC feet) were included in this study. For CN and TC patients, the mean age at the time of surgery was 11.8 ± 1.1 and 11.9 ± 2.5 years, and the mean age at follow-up was 27.1 ± 1.1 and 25.0 ± 2.5 years, respectively. Results: Inversion and eversion were significantly less for TC feet when compared with CN (P = .03 and P = .01, respectively). No difference was noted between the CN and TC groups with respect to outcome scores. Furthermore, no association was noted between the size of TC coalition or hindfoot valgus angle with respect to outcome scores. Conclusion: Resected CN and TC bars behaved similarly in the long term in terms of function and patient satisfaction. Favorable results were attained when resections were performed on TC coalitions that were greater than 50% of the posterior facet and hindfoot valgus angles greater than 16 degrees. Level of Evidence: Level III, retrospective comparative study.

The epidemiology of primary anterior shoulder dislocations in patients aged 10 to 16 years.

Background: Clinical studies of shoulder dislocations typically include adult patients (>16 years of age). Only small case series of patients aged 10 to 16 years are available to guide management. Purpose: Using a cohort of patients aged 10 to 16 years, this study sought to determine (1) the incidence density rate (IDR) of primary anterior shoulder dislocations requiring closed reduction (CR) and (2) the rate of and risk factors for repeat shoulder CR. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: With use of administrative databases, patients aged 10 to 16 years who underwent CR of a primary anterior shoulder dislocation in Ontario, Canada, between April 2002 and September 2010 were gathered. IDRs for the entire cohort and demographic subgroups were calculated. The main outcome, repeat shoulder CR, was sought until September 2012. The cumulative incidence of repeat CR was calculated at multiple time points for the entire cohort and age subgroups. A competing risk model identified risk factors for repeat CR (reported as hazard ratios [HRs] with 95% CIs). Results: There were 1937 patients aged 10 to 16 years who underwent primary CR (median age, 15.0 years; 79.7% male). The incidence of primary CR was highest among male patients aged 16 years (164.4 per 100,000 person-years), but primary dislocations were rare in 10- to 12-year-old children (n = 115; 5.9% of all dislocations). Repeat CR was observed in 740 patients (38.2%) after a median of 0.8 years; however, the rate of repeat CR was age dependent: it was highest among 14- to 16-year-old patients (37.2%-42.3%) and considerably lower among 10- to 13-year-old patients (0%-25.0%). Male sex (HR, 1.2 [95% CI, 1.0-1.5]; P = .04) and older patient age (HR, 1.2 [95% CI, 1.1-1.3]; P < .001) significantly increased the odds of repeat CR. Conclusion: Among 14- to 16-year-old patients, the rate of primary and recurrent shoulder CR mirrors that of high-risk adults (17-20 years of age) from previously published data; however, the rate of shoulder CR (primary or recurrent) is considerably lower among 10- to 13-year-olds. In addition to older patient age, male sex increased the odds of repeat shoulder CR. Going forward, clinicians should counsel male patients and those aged 14 to 16 years regarding their increased risk of recurrence after the nonoperative management of a primary anterior shoulder dislocation.

Antibiotic Prophylaxis to Prevent Surgical Site Infections in Children: A Prospective Cohort Study

OBJECTIVE To investigate the association between antibiotic prophylaxis (AP) and surgical-site infection in pediatric patients. BACKGROUND Surgical-site infections (SSIs) are a major cause of postoperative morbidity and mortality. Despite numerous studies in adults, benefit of AP in preventing SSIs in children is uncertain. METHODS Patients aged 0 to 21 years who underwent surgical procedures at a pediatric acute care hospital from April 1, 2009, to December 31, 2010, were assessed. Antibiotic prophylaxis indication and administration according to an evidence-based guideline were recorded. Complete compliance was defined as AP given, when indicated, within 60 minutes before incision. Surgical-site infections were identified using the Centers for Disease Control and Prevention criteria and documented in the medical records using the International Classification of Diseases, Tenth Revision. Multiple logistic regressions adjusting for age, sex, American Society of Anesthesiologists status, wound classification, admission status, surgical discipline, and surgical duration evaluated association of AP compliance and SSI. RESULTS Of 5309 patients for whom antibiotics were indicated, 3901 (73.5%) with complete compliance had an infection rate of 3.0%, whereas 1408 (26.5%) who were not compliant had an infection rate of 4.3% (adjusted relative risk: 0.7; 95% confidence interval: 0.5-0.9; P = 0.02). Of 4156 patients for whom antibiotics were not indicated, the 895 (21.5%) who received antibiotics had an infection rate of 1.7% compared with 0.7% in the 3261 (78.5%) who did not receive antibiotics (adjusted relative risk: 1.6; 95% confidence interval: 0.8-3.1; P = 0.18). CONCLUSIONS In pediatric surgery, complete compliance with AP was associated with 30% decreased risk of SSI.

The epidemiology of paediatric supracondylar fracture fixation: a population-based study.

INTRODUCTION The epidemiology of paediatric supracondylar fracture (SCF) fixation has not been evaluated at a population level. The purpose of this study was to: (1) determine the incidence density rate (IDR) of SCF fixation and (2) determine the rate of and risk factors for re-operation. METHODS Using administrative databases, all patients who underwent SCF fixation (closed reduction percutaneous pinning (CRPP) or open reduction (OR)) in Ontario between April 2002 and March 2010 were identified. Exclusion criteria included age (>12 years), a prior or concurrent non-SCF elbow fracture or previous humeral osteotomy. The overall IDR of SCF fixation and for subgroups of age, sex and season were calculated. A multivariate regression (immediate and short-term re-operation) and a Cox proportional hazards model (long-term re-operation) were used to identify patient, injury and provider factors that influenced re-operation risk and were reported as odds ratios or hazard ratios (HRs) with 95% confidence intervals (CIs), respectively. RESULTS A total of 3235 patients with a median age of 6.0 years (interquartile range (IQR): 3.0) underwent SCF fixation. The median follow-up was 6.0 years (IQR: 3.7). The majority underwent a CRPP (78.7%) which were performed after hours (75.6%). The overall IDR was 20.7/100,000 person-years (py), but it varied significantly by season and age. Re-operation was uncommon in the immediate (1.0%), short-term (1.4%) and long-term (0.3%) follow-up period. As compared to CRPP, patients who underwent OR were more likely to undergo early nerve exploration (odds ratio: 7.8 (CI: 3.0-20.6)) and re-operation in the long term (HR: 3.0 (CI: 1.0-8.7)). Increased surgeon volume of SCF fixation was protective against repeat fixation (odds ratio: 0.9 (CI: 0.9-1.0)) and re-operation in the long term (HR: 0.9 (CI: 0.8-1.0)). CONCLUSIONS While SCF fixation is common, the rate of re-operation is low. No differences existed between the sexes and a higher volume of fixations occurred during the summer months.

The sizing of hamstring grafts for anterior cruciate reconstruction: intra- and inter-observer reliability

AbstractPurpose The objective of this study was to establish the intra- and inter-observer reliability of hamstring graft measurement using cylindrical sizing tubes. Methods Hamstring tendons (gracilis and semitendinosus) were harvested from ten cadavers by a single surgeon and whip stitched together to create ten 4-strand hamstring grafts. Ten sports medicine surgeons and fellows sized each graft independently using either hollow cylindrical sizers or block sizers in 0.5-mm increments—the sizing technique used was applied consistently to each graft. Surgeons moved sequentially from graft to graft and measured each hamstring graft twice. Surgeons were asked to state the measured proximal (femoral) and distal (tibial) diameter of each graft, as well as the diameter of the tibial and femoral tunnels that they would drill if performing an anterior cruciate ligament (ACL) reconstruction using that graft. Reliability was established using intra-class correlation coefficients.ResultsOverall, both the inter-observer and intra-observer agreement were >0.9, demonstrating excellent reliability. The inter-observer reliability for drill sizes was also excellent (>0.9). Excellent correlation was seen between cylindrical sizing, and drill sizes (>0.9).ConclusionsSizing of hamstring grafts by multiple surgeons demonstrated excellent intra-observer and intra-observer reliability, potentially validating clinical studies exploring ACL reconstruction outcomes by hamstring graft diameter when standard techniques are used.Level of evidenceIII.

Reoperations After Tarsal Coalition Resection: A Population-Based Study

Few studies have evaluated the incidence of subsequent operations after tarsal coalition resection. Using administrative databases, we followed up a cohort of patients who had undergone tarsal coalition resection to determine the rates and possible risk factors for subsequent resection or arthrodesis. Patients (aged 8 years or older) who had been treated from July 1994 to August 2009 in Canada were identified and included. Those with nonidiopathic coalitions were excluded. The time-to-event data for the earliest subsequent procedure were fit to a Cox proportional hazards model that evaluated the patient, operative, and provider factors. Controlling for covariates, the hazard ratios were computed; however, the laterality of any subsequent operation could not be confirmed. A total of 304 patients underwent tarsal coalition resection at an average age of 24.2 ± 17.5 years. Of these 304 patients, 26 (8.6%) underwent subsequent resection and 16 (5.3%) mid- or hindfoot arthrodesis. Of all the factors, the need for future fusion was more likely only if the primary resection had been performed at an academic hospital or if the patient had undergone concomitant arthrodesis at primary resection of the coalition (hazard ratio 3.0, 95% confidence interval 1.1 to 8.5; and hazard ratio 9.7, 95% confidence interval 1.7 to 56.1, respectively). The incidence of reoperation after primary tarsal coalition resection was low in our cohort. More than 85% of our patients never required additional operative intervention an average of 9 years after the initial resection. Our data also suggest that primary treatment of tarsal coalition with resection and concomitant arthrodesis increases the risk of requiring a second fusion in the future.

Outcomes of infection following pediatric spinal fusion.

BACKGROUND Removal of instrumentation is often recommended as part of treatment for spinal infections, but studies have reported eradication of infection even with instrumentation retention by using serial débridements and adjuvant antibiotic pharmacotherapy. We sought to determine the effect of instrumentation retention or removal on outcomes in children with spinal infections. METHODS We retrospectively reviewed the cases of patients who experienced early (< 3 mo) or late (≥ 3 mo) infected spinal fusions. Patients were evaluated at least 2 years after eradication of the infection using the following protocol outcomes: follow-up Cobb angle, curve progression and nonunion rates. RESULTS Our sample included 35 patients. The mean age at surgery was 15.1 ± 6.0 years, 65.7% were girls, and mean follow-up was 41.7 ± 26.9 months. The mean Cobb angle was 63.6° ± 14.5° preoperatively, 29.4° ± 16.5° immediately after surgery and 37.2° ± 19.6° at follow-up. Patients in the implant removal group (n = 21) were more likely than those in the implant retention group (n = 14) to have a lower ASA score (71.4% v. 28.6%, p = 0.03), fewer comorbidities (66.7% v. 21.4%, p = 0.03), late infections (81.0% v. 14.3%, p = 0.01) and deep infections (95.2% v. 64.3%, p = 0.03). Implants were retained in 12 of 16 (75.0%) patients with early infections and 2 of 19 (10.5%) with late infections. Patients with implant removal had a higher pseudarthrosis rate (38.1% v. 0%, p = 0.02) and a faster curve progression rate (5.8 ± 9.8° per year v. 0.2 ± 4.7° per year, p = 0.04). CONCLUSION Implant retention should be considered, irrespective of the timing or depth of the infection.