Factors associated with increased 30-day re-operation risk in anterior cruciate ligament reconstruction.

BACKGROUND: Revision surgery following isolated anterior cruciate ligament reconstruction (ACLR) has often focused on mid- to long-term revisions due to re-rupture, while short-term 30-day revision is a rare, but underappreciated entity. This study aims to characterize incidence and risk factors for reoperations following isolated ACLR. METHODS: This is a retrospective case-control analysis of the American College of Surgeons National Surgical Quality Improvement Program Database (NSQIP) database from 2005 to 2017. Current Procedural Terminology codes were used to identify elective isolated ACLR patients. Patients undergoing reoperations were analyzed using bivariate analysis against their respective perioperative variables. Multivariate stepwise logistic regression was used to identify independent risk factors for reoperations after ACLR. RESULTS: 12,790 patients were included in the study. 37.0% of patients were female. Mean age was 32.2+/-10.7 years and mean body mass index (BMI) was 27.8+/-6.5 kg/m2, with 28.9% of patients with BMI > 30. The most frequently reported reason for reoperation based on CPT and ICD-9/10 codes was postoperative infection (0.5%). Overall reoperation rate was approximately 0.5%. Multivariate analysis identified operative time >1.5 h (OR 2.6 [95% CI; 1.5-4.4]), dependent functional status (OR 14.0 [1.4-141.6]), and adjunctive anesthesia (OR 2.4 [95% CI; 1.1-5.0]) as independent risk factors for reoperation. Female sex was a protective factor against reoperations (OR 0.6 [0.3-0.98]). CONCLUSION: Primary, isolated ACLR is associated with extremely low rates of short-term reoperations. Operative time >1.5 h, dependent functional status, and adjunctive anesthesia were independent risk factors for reoperation and female sex was a protective factor against reoperation. LEVEL OF EVIDENCE: Level III. Retrospective cohort study.

Flexor Hallucis Longus Tenolysis and Tenosynovectomy in Dancers.

The purpose of this study was to report on a series of dancers who had undergone flexor hallucis longus (FHL) tenolysis/tenosynovectomy after having failed conservative management. Institutional human subjects committee approval was obtained prior to initiating this study. This study is a retrospective case series of 58 dancers and 63 ankles who underwent FHL tenolysis/tenosynovectomy via an open posteromedial approach by a single surgeon between 1993 and 2017. All patients were interviewed and charts reviewed. Collected variables included: preoperative and postoperative pain levels, time to return to dance, and subjective satisfaction with the procedure. Age, primary dance form, and level of dance were determined. Mean preoperative pain level decreased significantly postoperatively. Mean time to return to dance was 7.1 weeks. There was a 98% (62/63) return to dance at some level while 97% (61/63) of patients returned to dance symptom-free. There were no neurovascular or other major complications. Minor complications included stiffness at follow-up (6.3%, 4/63), superficial wound infection (3.1%, 2/63), and hypertrophic scar (4.8%, 3/63). Over 97% (61/63) of dancers considered the procedure a success and 98% (62/63) of dancers would repeat the procedure. This is one of the largest series reported of isolated FHL tenolysis/tenosynovectomy in dancers who have failed nonoperative management. Satisfactory pain relief and return to dance with a low complication rate may be expected from this surgical procedure. The results of this study can be used to help dancers and their providers make informed decisions about treatment in isolated FHL tendinitis.

Excision of Os Trigonum in Dancers via an Open Posteromedial Approach.

An os trigonum is a potential source of posterior ankle pain in dancers, often associated with flexor hallucis longus (FHL) pathology. Surgical excision is indicated on failure of nonoperative management. Options for surgical excision include open excision (via a posterolateral or posteromedial approach), subtalar arthroscopy, and posterior endoscopy. Os trigonum excision via an open posteromedial approach with concomitant FHL tenolysis/tenosynovectomy is a safe and effective method for the operative treatment of a symptomatic os trigonum that allows for identification and treatment of associated FHL pathology. The major steps in the procedure, which are demonstrated in this video article, are: (1) preoperative planning with appropriate imaging; (2) patient is positioned in a supine position with the operative extremity in figure-of-4 position; (3) a 3-cm, slightly curvilinear longitudinal incision is made midway between the posterior aspect of the medial malleolus and the anterior aspect of the Achilles tendon, over the palpated FHL tendon, and the flexor retinaculum is exposed and incised; the neurovascular bundle is retracted anteriorly, exposing the FHL tendon and sheath; (4) FHL tenolysis/tenosynovectomy is performed; (5) the FHL is retracted anteriorly and a capsulotomy is performed over the os trigonum and the os trigonum is excised; (6) the capsule is repaired and closure is performed; and (7) dressings and a CAM (controlled ankle motion) walking boot are applied. The patient begins physical therapy at 2 weeks postoperatively and may return to dance at 4 to 6 weeks postoperatively as tolerated. In our series of 40 cases, 95% of patients who desired to return to dance were able to return to their pre-injury level of dance. There were no major neurovascular complications.

Os Trigonum Excision in Dancers via an Open Posteromedial Approach.

BACKGROUND: An os trigonum is a potential source of posterior ankle pain in dancers, often associated with flexor hallucis longus (FHL) pathology. Options for operative excision include open excision, subtalar arthroscopy, and posterior endoscopy. The purpose of this paper was to present a series of dancers who underwent excision of a symptomatic os trigonum via an open posteromedial approach. METHODS: This study is a retrospective case series of 40 ankles in 38 dancers who underwent os trigonum excision via an open posteromedial approach with FHL tenolysis between 2000 and 2013. All patients were interviewed and charts retrospectively analyzed. Collected variables included pre- and postoperative pain level, time to return to dance, and subjective satisfaction. The average age was 19.2 years; ballet was the primary dance form in 36 (95%) of patient-cases. Eight (20%) of the patient-cases were professional dancers, and 30 (75%) were students or preprofessional dancers. RESULTS: Average preoperative pain level was 7.7/10, which decreased to 0.6/10 postoperatively. Seventeen (42.5%) experienced concurrent preoperation-associated FHL symptomatology, all of whom experienced relief postoperatively. The average time to return to dance was 7.9 weeks, and time to pain-free dance was 17.7 weeks. Of the 37 patient-cases desiring to return to dance, 35 (94.6%) returned to their preoperative level of dance. There were no neurovascular or other major complications. Four (10%) had minor wound complications that resolved, and 38 cases (95%) considered the procedure a success. CONCLUSION: Open posteromedial excision of an os trigonum in dancers provided satisfactory pain relief, return to dance, and complication rates compared to other approaches, and allowed for identifying and treating any associated FHL pathology. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Iliopsoas Syndrome in Dancers.

BACKGROUND: Coxa saltans refers to a constellation of diagnoses that cause snapping of the hip and is a major cause of anterior hip pain in dancers. When the internal type is accompanied by weakness or pain, it is referred to as iliopsoas syndrome. Iliopsoas syndrome is the result of repetitive active hip flexion in abduction and can be confused with other hip pathology, most commonly of labral etiology. PURPOSE: To report the incidence, clinical findings, treatment protocol, and results of treatment for iliopsoas syndrome in a population of dancers. STUDY DESIGN: Retrospective case series; Level of evidence, 4. METHODS: A retrospective database review of 653 consecutive patients evaluated for musculoskeletal complaints over a 3-year period was completed. The diagnosis of iliopsoas syndrome was made based on anterior hip or groin pain, weakness with resisted hip flexion in abduction, or symptomatic clicking or snapping with a positive iliopsoas test. Patients identified with iliopsoas syndrome were further stratified according to age at time of onset, insidious versus acute onset, duration of symptoms, side of injury, presence of rest pain, pain with activities of daily living, and associated lower back pain. All patients diagnosed with iliopsoas syndrome underwent physical therapy, including hip flexor stretching and strengthening, pelvic mobilization, and modification of dance technique or exposure as required. RESULTS: A total of 49 dancers were diagnosed and treated for iliopsoas syndrome. Within this injured population of 653 patients, the incidence in female dancers was 9.2%, significantly higher than that in male dancers (3.2%). The mean age at the time of injury was 24.6 years. The incidence of iliopsoas syndrome in dancers younger than 18 years was 12.8%, compared with 7% in dancers older than 18 years. Student dancers had the highest incidence (14%), followed by amateur dancers (7.5%), while professional dancers had the lowest incidence (4.6%). All patients responded to conservative treatment, and no patients required corticosteroid injections or surgical intervention. CONCLUSION: This is the largest series reported to date of iliopsoas syndrome in the dance population, treated noninvasively. This study supports that conservative treatment with nonsteroidal anti-inflammatory medication, activity modification, and a physical therapy regimen specific to the iliopsoas should be the primary treatment for patients with iliopsoas syndrome. CLINICAL RELEVANCE: This study supports current literature and conservative treatment of iliopsoas syndrome diagnosis. Furthermore, this study gives specific information regarding incidence of iliopsoas syndrome in dance populations and provides a test for diagnosis and an algorithm for treatment.

Myositis ossificans within the intercondylar notch treated arthroscopically.

We present a case of intraarticular myositis ossificans in the right knee of a child. Myositis ossificans (MO), though relatively rare in childhood and even more uncommon within a joint, should be included in the differential diagnosis of an intra-articular mass when indicated by the typical clinical, radiographic, and histologic findings. An 11-year-old male presented with a history of trauma to his right knee. Four weeks after the initial injury, an MRI demonstrated evidence of an ACL rupture with a "cystic mass" within the intercondylar notch along the anterior surface of the torn ligament. At subsequent arthroscopy, the mass noted on MRI was removed. The histology was consistent with MO. The authors believe this to be the first case of MO in the intercondylar notch detected by MRI, treated by arthroscopy, and confirmed by histology.

MR imaging of complications of anterior cruciate ligament graft reconstruction.

During the past 3 decades, graft reconstruction of the anterior cruciate ligament (ACL) has become an accepted treatment for symptomatic ACL deficiency. The goal of surgery is to prevent joint instability, which may further damage articular cartilage and menisci. Graft failure is defined as pathologic laxity of the reconstructed ACL. The prevalence of recurrent instability after primary ACL reconstruction ranges from 1% to 8%. Early failures, those that occur within the first 6 months, often are secondary to poor surgical technique, failure of graft incorporation, or errors in rehabilitation. Late failures, those that occur more than 1 year after surgery, likely are related to new trauma and graft tearing. Other complications of ACL reconstruction include roof impingement, postoperative stiffness, tunnel widening due to cyst formation, iliotibial band friction syndrome, hardware failure, and infection. Magnetic resonance imaging is the preferred advanced imaging modality for the evaluation of symptomatic ACL graft reconstructions.

Surgical treatment of refractory tibial stress fractures in elite dancers: a case series.

BACKGROUND: Treatment of tibial stress fractures in elite dancers is centered on rest and activity modification. Surgical intervention in refractory cases has important implications affecting the dancers' careers. HYPOTHESIS: Refractory tibial stress fractures in dancers can be treated successfully with drilling and bone grafting or intramedullary nailing. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1992 and 2006, 1757 dancers were evaluated at a dance medicine clinic; 24 dancers (1.4%) had 31 tibial stress fractures. Of that subset, 7 (29.2%) elite dancers with 8 tibial stress fractures were treated operatively with either intramedullary nailing or drilling and bone grafting. Six of the patients were followed up closely until they were able to return to dance. One patient was available only for follow-up phone interview. Data concerning their preoperative treatment regimens, operative procedures, clinical union, radiographic union, and time until return to dance were recorded and analyzed. RESULTS: The mean age of the surgical patients at the time of stress fracture was 22.6 years. The mean duration of preoperative symptoms before surgical intervention was 25.8 months. Four of the dancers were male and 3 were female. All had failed nonoperative treatment regimens. Five patients (5 tibias) underwent drilling and bone grafting of the lesion, and 2 patients (3 tibias) with completed fractures or multiple refractory stress fractures underwent intramedullary nailing. Clinical union was achieved at a mean of 6 weeks and radiographic union at 5.1 months. Return to full dance activity was at an average of 6.5 months postoperatively. CONCLUSION: Surgical intervention for tibial stress fractures in dancers who have not responded to nonoperative management allowed for resolution of symptoms and return to dancing with minimal morbidity.

Metabolomics for early detection of drug-induced kidney injury: review of the current status.

The identification of biomarkers of drug-induced kidney injury is an area of intensive focus in drug development. Traditional markers of renal function, including blood urea nitrogen and serum creatinine, are not region-specific and only increase significantly after substantial kidney injury. Therefore, more sensitive markers of kidney injury are needed. The ideal biomarkers will identify nephrotoxicity early in the drug-discovery process, resulting in decreased development costs and safer drugs. Metabolomics, the study of the small biochemicals present in a biological sample, has become a promising player in the nephrotoxicity arena. In this review, we describe the current status of the identification of metabolic biomarkers for drug-induced kidney toxicity screening. Many of these markers have been confirmed across multiple studies and can detect nephrotoxicity earlier than the traditional clinical chemistry and histopathology methods. Upon further validation, such markers will offer clear benefits for the pharmaceutical industry and regulatory agencies.

Incidence of anterior cruciate ligament injuries among elite ballet and modern dancers: a 5-year prospective study.

BACKGROUND: Ballet and modern dance are jump-intensive activities, but little is known about the incidence of anterior cruciate ligament (ACL) injuries among dancers. HYPOTHESIS: Rigorous jump and balance training has been shown in some prospective studies to significantly reduce ACL injury rates among athletes. Dancers advance to the professional level only after having achieved virtuosic jump and balance technique. Therefore, dancers on the elite level may be at relatively low risk for ACL injury. STUDY DESIGN: Descriptive epidemiology study. METHODS: Dance exposure, injuries, and injury conditions were systematically recorded at 4 dance organizations over 5 years. Select neuromuscular and psychometric variables were compared between and within ACL-injured and noninjured dancers. RESULTS: Of 298 dancers, 12 experienced an ACL injury over the 5-year period. The incidence of ACL injury was 0.009 per 1000 exposures. Landing from a jump onto 1 leg was the mechanism of injury in 92% of cases. Incidence was not statistically different between gender or dance groups, although women modern dancers had a 3 to 5 times greater relative risk than women ballet dancers and men dancers. No difference between ACL-injured and noninjured dancers emerged with regard to race, oral contraceptive use, or select musculoskeletal measures. CONCLUSION: Dancers suffer considerably fewer ACL injuries than athletes participating in team ball sports. The training dancers undertake to perfect lower extremity alignment, jump, and balance skills may serve to protect them against ACL injury. Anterior cruciate ligament injuries happened most often late in the day and season, suggesting an effect of fatigue.

Efficient fully implicit time integration methods for modeling cardiac dynamics.

Implicit methods are well known to have greater stability than explicit methods for stiff systems, but they often are not used in practice due to perceived computational complexity. This paper applies the backward Euler (BE) method and a second-order one-step two-stage composite backward differentiation formula (C-BDF2) for the monodomain equations arising from mathematically modeling the electrical activity of the heart. The C-BDF2 scheme is an L-stable implicit time integration method and easily implementable. It uses the simplest forward Euler and BE methods as fundamental building blocks. The nonlinear system resulting from application of the BE method for the monodomain equations is solved for the first time by a nonlinear elimination method, which eliminates local and nonsymmetric components by using a Jacobian-free Newton solver, called Newton--Krylov solver. Unlike other fully implicit methods proposed for the monodomain equations in the literature, the Jacobian of the global system after the nonlinear elimination has much smaller size, is symmetric and possibly positive definite, which can be solved efficiently by standard optimal solvers. Numerical results are presented demonstrating that the C-BDF2 scheme can yield accurate results with less CPU times than explicit methods for both a single patch and spatially extended domains.

Arthroscopic treatment of anterior ankle impingement syndrome in dancers.

BACKGROUND: The purpose of this study was to evaluate the results of arthroscopic treatment of anterior bony and soft-tissue impingement of the ankle in elite dancers. METHODS: The study is a case series retrospectively reviewed. In the period between 1990 and 1999, 11 elite dancers (12 ankles) had ankle arthroscopy after a diagnosis of anterior ankle impingement that markedly interfered with their dancing. Initial nonoperative treatment failed in all subjects. Previous ankle trauma was noted in all subjects. There were seven women and four men (average age 28 years). Tibiotalar exostoses were radiographically noted in six ankles. Standard anteromedial and anterolateral arthroscopic portals and instrumentation were used for resection of bone spurs and debridement of impinging soft tissues. Patients were nonweightbearing for 5 days after surgery and had postoperative physiotherapy. RESULTS: Nine dancers returned to full dance activity at an average of 7 weeks after surgery. One patient did not return to dance performance because of concurrent unrelated orthopaedic problems, but he resumed work as a dance teacher; he developed a recurrent anterior tibial spur that was successfully resected at a second arthroscopy 9 years later. Another dancer developed postoperative scar-tissue impingement and stiffness; she had a repeat arthroscopy 4 months after the initial procedure and subsequently returned to dance performance. All patients eventually had marked postoperative improvement in pain relief and dance performance. CONCLUSIONS: Arthroscopic debridement is an effective method for the treatment of bony and soft-tissue anterior ankle impingement syndrome in dancers and has minimal morbidity.

Anterior cruciate ligament radiofrequency thermal shrinkage: a short-term follow-up.

PURPOSE: To review the results of 34 patients who underwent radiofrequency thermal shrinkage (RFTS) for treatment of anterior cruciate ligament (ACL) laxity in the attenuated and partially torn ACL. TYPE OF STUDY: Retrospective cross-sectional survey performed at least 6 months after treatment. METHODS: Patients with recurrent instability after attenuation of ACL autografts and partially torn ACLs were treated with RFTS. Follow-up included subjective questionnaires (International Knee Documentation Committee [IKDC], Tegner, and Lysholm) and objective clinical tests (IKDC, KT-1000, pivot-shift, Lachman, single-leg hop). RESULTS: Mean follow-up was 21.4 months. Based on IKDC and subjective evaluation, 18 of 20 (90%) partially torn ACLs and 10 of 14 reconstructed ACLs (71%) treated with RTFS were judged to have good or excellent knee function (overall 82%). ACL laxity based on KT-1000 was less successful, with 15 of 20 (75%) partially torn ACLs and 8 of 12 (66%) reconstructed ACLs considered successful. CONCLUSIONS: With no major complications in this study, we conclude that RFTS for treatment of ACL laxity is a well-tolerated procedure with success rates around 71% to 90% in selected patients. RFTS may be offered as a less-extensive alternative to patients being considered for ACL reconstruction who have either attenuated or partially torn ligaments, especially in the athletically low-demand population. LEVEL OF EVIDENCE: Level IV, case series.

Simultaneous ipsilateral ruptures of the anterior cruciate ligament and patellar tendon: a case report.

The simultaneous diagnosis of ipsilateral patellar tendon rupture and anterior cruciate ligament tear is rare. Surgical repair is complicated by different rehabilitation regimens as well as anterior cruciate ligament graft choices. We present a case where at the same operative setting, the patellar tendon was repaired, and the anterior cruciate ligament reconstructed with autologous hamstring graft.

A resistor interpretation of general anisotropic cardiac tissue.

This paper describes a spatial discretization scheme for partial differential equation systems that contain anisotropic diffusion. The discretization method uses unstructured finite volumes, or the boxes, that are formed as a secondary geometric structure from an underlying triangular mesh. We show how the discretization can be interpreted as a resistive circuit network, where each resistor is assigned at each edge of the triangular element. The resistor is computed as an anisotropy dependent geometric quantity of the local mesh structure. Finally, we show that under certain conditions, the discretization gives rise to negative resistors that can produce non-physical hyperpolarizations near depolarizing stimuli. We discuss how the proper choice of triangulation (anisotropic Delaunay triangulation) can ensure monotonicity (i.e. all resistors are positive).

Arthroscopic management of spinoglenoid cysts associated with SLAP lesions and suprascapular neuropathy.

Suprascapular neuropathy secondary to cyst compression in the spinoglenoid notch may occur in association with SLAP tears. Arthroscopic techniques may be employed for both cyst excision and repair of labral pathology. We describe 3 cases in which preoperative and postoperative electromyograms and magnetic resonance imaging documented cyst resolution and return of suprascapular nerve function after arthroscopic spinoglenoid cyst excision and labral repair.

Low-energy anterior hip dislocation in a dancer.

In this article, we report the case of a healthy young woman who sustained an anterior hip dislocation while participating in a noncontact activity (ballet dancing). The patient's atraumatic dislocation failed closed reduction secondary to interposition of anterior capsule and rectus femoris muscle. Open reduction using a Smith-Petersen approach was concentric and stable. Postinjury femoral nerve neuropraxia resolved within 6 weeks. At 2-year follow-up, the patient was without complications of the injury-including avascular necrosis and posttraumatic arthritis. She returned to dancing and is now asymptomatic.