Morphometric analysis of the proximal thoracic pedicles in Lenke II and IV adolescent idiopathic scoliosis: an evaluation of the feasibility for pedicle screw insertion.

PURPOSE: Pedicles on the concave side of the proximal thoracic (PT) curve in adolescent idiopathic scoliosis (AIS) patients with Lenke II and IV deformities tend to be narrow and dysplastic, making pedicle screw (PS) insertion challenging. The aim of this study was to evaluate the feasibility for PS placement in these patients using pedicle chord length, diameter, and channel morphology. METHODS: In this retrospective study, 56 consecutive AIS patients with Lenke II or IV curves who underwent instrumented posterior spinal fusion (PSF) were studied. The mean age at surgery was 14.8 years and the mean PT curve measured 45°. Two independent investigators evaluated all visible pedicles from T1 to T6 vertebral levels using axial images from intraoperative computed tomography-guided navigation recording the pedicle: (1) maximum transverse diameter 'd' at the isthmus, (2) maximum chord length 'l', and (3) qualitative assessment of the channel morphology (types A-D). RESULTS: Two hundred and sixty-eight concave and 264 convex pedicles were measured. The mean 'd' of the concave pedicles at T3 and T4 was < 3.0 mm, compared to > 5.0 mm for the convex counterparts (p < 0.001). Of all concave pedicle channels, 48% had morphology characteristics that were riskier for PS cannulation (type C or D) compared to 2% of all convex pedicle channels (type A or B) (p < 0.001). CONCLUSION: Almost half of all concave pedicles have morphologic characteristics that make them too small to accommodate a PS. Though PSs could be inserted using an in-out-in technique in these patients, alternative fixation anchors may improve strength and safety.

Long-Term Outcomes for Arthroscopic Thermal Treatment for Scapholunate Ligament Injuries.

Background Arthroscopic electrothermal treatment of low-grade Geissler's scapholunate interosseous ligament (SLIL) tears has shown clinical benefit at short-term follow-up. Questions/Purpose This study aims to evaluate the long-term functional outcomes in patients undergoing this treatment. Patients and Methods A retrospective review of all patients treated between 2005 and 2013 was performed. Patients were excluded with less than 5 years of follow-up, the presence of static SLIL injuries, prior wrist surgery, and concomitant denervation. Symptom resolution, return to activity, postoperative complications, range of motion, grip strength, and subsequent treatment were recorded. Each patient completed Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), Modified Mayo Wrist (MMW), and Patient-Rated Wrist Evaluation (PRWE) questionnaires. Results Nine patients underwent treatment for Geissler's grade I, II, and III SLIL injuries with a mean 7 years (range: 5-11 years) of follow-up. Mean grip strength was 99% of the nonsurgical extremity. Wrist motion was near symmetric with a mean of 76 (±14), 74 (±8), 21 (±13), and 40 degrees (±13) for wrist flexion, extension, radial deviation, and ulnar deviation. QuickDASH improved significantly by a mean 39 points (50 (preoperative)-11 [postoperative], p = 0.009). Postoperative MMW and PRWE scores were 83 and 14, respectively. Visual analog scale (VAS) score was 1.4. A total of 90% was returned to their preinjury level of function or higher. Conclusions Arthroscopic electrothermal treatment of low-grade Geissler's SLIL tears demonstrates excellent objective and subjective outcomes at a minimum 5-year follow-up, providing evidence that this is an effective, safe, and, most importantly, durable-therapeutic modality. Level of Evidence This is a Level IV, case series study.

Long-Term Outcomes of All-Arthroscopic Pre-Tied Suture Device Triangular Fibrocartilage Complex Repair.

Background A pre-tied suture device has been utilized for all-arthroscopic peripheral triangular fibrocartilage complex (TFCC) repairs with promising early clinical results. Purpose The purpose of this study was to evaluate long-term functional outcomes of these repairs. Patients and Methods A retrospective review of patients undergoing arthroscopic TFCC repair was performed. Inclusion criteria were the Palmer type 1B TFCC tears diagnosed on arthroscopy and repaired using the all-arthroscopic pre-tied suture device. Patients with any evidence of concomitant wrist injury at the time of surgery, history of prior wrist surgery, or nonrepairable and nonperipheral TFCC tears were excluded. Postoperative complications, range of motion, grip strength, and outcome assessments were recorded for each patient. Results Eleven patients (mean age, 36 years; range, 20-64 years) satisfied our inclusion criteria and comprised the study cohort. The mean follow-up period was 7.0 years (range, 4.3-10.9 years). Mean range of motion of the wrist revealed flexion of 76 ± 11 degrees and extension of 73 ± 12 degrees. Mean grip strength was 98 ± 15% of the nonsurgical extremity. QuickDASH, modified Mayo, and patient-rated wrist evaluation (PRWE) average scores were 9 ± 8, 80 ± 6, and 12 ± 12, respectively. No surgical complications were observed and no patient required any further surgical intervention. Conclusions Our cohort of patients following all-arthroscopic pre-tied suture device repair of isolated Palmer type 1B TFCC tears demonstrated excellent clinical function at a mean follow-up of 7 years. These findings indicate that the pre-tied suture device is a reliable, safe, effective, and most importantly, durable treatment option for repair of peripheral TFCC tears. Level of Evidence This is a Level IV, therapeutic study.

Instability after reverse total shoulder arthroplasty.

BACKGROUND: This study evaluated patients with and without a prosthetic dislocation after reverse total shoulder arthroplasty (RTSA) to identify risk factors for instability. METHODS: Dislocation and nondislocation cohorts were established for analysis in 119 patients who had undergone RTSA at our institution between 2011 and 2014. Preoperative history and parameters pertaining to RTSA design were evaluated for correlation with instability. A logistic regression model was used to analyze independent predictors. RESULTS: Eleven patients (9.2%) demonstrated instability in the early postoperative period. Dislocations occurred at an average of 8 weeks postoperatively (range, 3 days-5 months). The mean follow-up of all patients was 28 months (range, 6-106 months). Postoperative instability was associated with male gender, history of prior open shoulder surgery, and preoperative diagnoses of fracture sequelae, particularly proximal humeral or tuberosity nonunion. Absence of subscapularis repair was an independent predictor of instability. In addition, 5 of the 11 patients (45%) in the instability cohort sustained a second dislocation requiring another operation. CONCLUSIONS: Redislocation after revision surgery for the initial dislocation was an unexpected and alarming finding. Treatment for the initial dislocation event by placement of a thicker polyethylene insert was inadequate in 45% of patients of our cohort and required another revision with a larger glenosphere and thicker humeral inserts. Initial instability after RTSA must be carefully managed, especially in the revision and post-traumatic setting. Exchange to a thicker polyethylene insert only carries a higher risk of recurrent instability.

Community-acquired Methicillin-resistant Staphylococcus aureus Musculoskeletal Infections: Emerging Trends Over the Past Decade.

BACKGROUND: The emergence of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has altered the management of pediatric musculoskeletal infections. Yet, institution-to-institution differences in MRSA virulence may exist, suggesting a need to carefully examine local epidemiological characteristics. The purpose of this study was to compare MRSA and methicillin-sensitive S. aureus (MSSA) musculoskeletal infections with respect to prevalence and complexity of clinical care over the past decade at a single children's hospital. METHODS: We retrospectively reviewed a series of patients presenting to The Children's Hospital of Philadelphia with a diagnosis of osteomyelitis, septic arthritis, or both over a 10-year period. Inclusion criteria were S. aureus (SA) infections proven by positive culture of blood, bone, or joint aspirate. Exclusion criteria were non-SA infectious etiologies. Hospital-acquired infections were also not included to exclusively evaluate acute, community-acquired cases. Data related to hospital course, laboratory values, and number of surgical interventions were collected and compared between MRSA and MSSA cohorts. RESULTS: In our series of pediatric patients, we identified 148 cases of acute, community-acquired musculoskeletal SA infections (MRSA, n=37 and MSSA, n=111). The prevalence of MRSA musculoskeletal infections increased from 11.8% in 2001 to 2002 to 34.8% in 2009 to 2010. Compared with MSSA, MRSA infections resulted in higher presenting C-reactive protein levels (10.4 vs. 7.8 mg/L, P=0.04), longer inpatient stays (10 vs. 5 d, P<0.01), multiple surgical procedures (n>1) (38% vs. 14%, P<0.01), increased sequelae (27% vs. 6%, P<0.01), and more frequent admissions to the intensive care unit (16% vs. 3%, P<0.01). CONCLUSIONS: At our institution over the past decade, we found an approximate 3-fold rise in community-acquired pediatric MRSA musculoskeletal infections accompanied by an elevated risk for complications during inpatient management. Awareness of the epidemiological trends of MRSA within the local community may guide parental counseling and facilitate timely and accurate clinical diagnosis and treatment. LEVEL OF EVIDENCE: Level II-prognostic retrospective study.

Complications of Elbow Trauma.

The elbow is a highly congruent trochoginglymoid joint allowing motion in both flexion-extension and pronosupination across 3 articulations. Therefore, treatment of fractures of the elbow can be technically challenging to manage, even after initial surgery. The posttraumatic elbow is prone to complications such as stiffness associated with heterotopic ossification, instability or subluxation (posterolateral rotatory instability and varus posteromedial instability patterns), and wound complications. This article discusses the pathoanatomy, prevention, and treatment of these complications.

Radiographic Follow-up of DDH in Infants: Are X-rays Necessary After a Normalized Ultrasound?

BACKGROUND: Concerns about radiation exposure have created a controversy over long-term radiographic follow-up of developmental dysplasia of the hip (DDH) in infants who achieve normal clinical and ultrasonographic examinations. The purpose of this study was to assess the importance of continued radiographic monitoring by contrasting the incidence of residual radiographic dysplasia to the risks of radiation exposure. METHODS: We reviewed a consecutive series of infants with idiopathic DDH presenting to our institution over 4 years. Infants with "normalized DDH" had achieved a stable clinical examination with an ultrasound revealing no signs of either hip instability or acetabular dysplasia. We excluded infants with persistently abnormal ultrasonographic indices, clinical examinations, or both by 6 months of age, including those requiring surgical reduction. Anteroposterior pelvic radiographs at approximately 6 and 12 months of age were then evaluated for evidence of residual radiographic acetabular dysplasia. Radiation effective dose was calculated using PCXMC software. RESULTS: We identified 115 infants with DDH who had achieved both normal ultrasonographic and clinical examinations at 3.1±1.1 months of age. At the age of 6.6±0.8 months, 17% of all infants demonstrated radiographic signs of acetabular dysplasia. Of infants left untreated (n=106), 33% had dysplasia on subsequent radiographs at 12.5±1.2 months of age. No significant differences were evident in either the 6- or 12-month rates of dysplasia between infants successfully treated with a Pavlik harness and infants normalizing without treatment but with a history of risk factors (P>0.05). The radiation effective dose was <0.01 mSv for the combined 6- and 12-month single-view anteroposterior radiographs of the pelvis. CONCLUSIONS: The notable incidences of radiographic dysplasia after previous DDH normalization in our study cohort appear to outweigh the risks of radiation exposure. Our findings may warrant radiographic follow-up in this population of infants through at least walking age to allow timely diagnosis and early intervention of residual acetabular dysplasia. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Is there a predilection for breech infants to demonstrate spontaneous stabilization of DDH instability?

BACKGROUND: Breech position subjects the fetal hip to abnormal mechanical forces. However, unlike genetic or tissue factors linked to developmental dysplasia of the hip (DDH), the causative effect of the breech position ends when the infant is born. The purpose of this study was to evaluate the rate of spontaneous stabilization in mildly unstable hips of breech-presenting infants compared with similarly lax hips in infants with a genetic or tissue-related cause of DDH. METHODS: We studied a consecutive series of infants presenting to our institution at 8 weeks of age or younger with DDH from January 2008 to January 2012. Infants with increased hip laxity on dynamic ultrasound examination but without frank instability on clinical provocation maneuvers and no history of prior treatment were evaluated. The endpoint was spontaneous stabilization of ultrasound-detected instability, or intervention due to persistent instability on follow-up dynamic ultrasound. A logistic regression model using backward likelihood ratio method was used to analyze predictors of spontaneous stabilization. RESULTS: We identified 122 hips in 79 infants with instability on dynamic ultrasound evaluation but with stable clinical examinations. Spontaneous stabilization of sonographic instability occurred in 90 hips (74%) at a mean age of 9 weeks (range, 4 to 18 wk). Breech hips more frequently spontaneously stabilized compared with nonbreech hips (80% vs. 66%). Regression analysis determined that breech presentation was a strong independent predictor for spontaneous hip stabilization (odds ratio, 3.72; 95% confidence interval, 1.45-9.60; P=0.006). Sex, family history, intrauterine positioning syndromes, side involved, bilateralism, and grade of sonographic hip instability were not independently predictive of spontaneous hip stabilization. CONCLUSIONS: DDH infants with a history of breech presentation are 3.72 times more likely to experience spontaneous resolution of mild hip instability compared with nonbreech infants. Awareness that breech presentation is a strong independent predictor of spontaneous laxity resolution can guide parental counseling and early care of DDH. LEVEL OF EVIDENCE: Level II, prognostic retrospective study.

Identical osteochondritis dissecans lesions of the knee in sets of monozygotic twins.

Osteochondritis dissecans (OCD) is a focal, idiopathic alteration of subchondral bone structure with the risk for secondary damage to adjacent articular cartilage and the development of premature osteoarthritis. The exact etiology of OCD is unknown, although repetitive microtrauma and vascular insufficiency have been previously described. A genetic predisposition has been suggested, but the existing evidence is sparse. There are multiple case reports of twins and siblings with OCD and a few large family series in the literature, promoting the theory that OCD may have a genetic component to its etiology. This article describes 2 sets of monozygotic twins presenting concurrently with OCD of their dominant knees, offering further support for a genetic component to the etiology of OCD. Interestingly, in both sets of twins, 1 was left-handed and 1 was right-handed. Both sets of twins had simultaneous presentations and clinical courses, lending support to a genetic element to OCD. The development of the OCD lesion in the dominant knee of each patient suggests an environmental influence, perhaps due to repetitive microtrauma and overuse. Recently, a genome-wide linkage study identified a prime candidate locus for OCD. However, despite the suggested association, genetic and developmental factors in the development of OCD remain relatively unstudied. The authors believe monozygotic twins provide an excellent clinical opportunity for future examination of the role of familial inheritance in the etiology of OCD.