Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

The $p_{\rm T}$-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D$^0$, D$^+$, and D$^{*+}$ in the rapidity range $|y|<0.5$, and for transverse momentum $1< p_{\rm T} <12$ GeV/$c$, were measured in proton-proton collisions at $\sqrt{s} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D$^0 \rightarrow$K$\pi$, D$^+ \rightarrow$K$\pi\pi$, D$^{*+} \rightarrow$D$^0\pi$, and their charge conjugates, and was performed on a $L_{\rm int} = 1.1$ nb$^{-1}$ event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at $\sqrt{s} = 2.76$ TeV and at 7 TeV was evaluated by extrapolating to the full phase space the $p_{\rm T}$-differential production cross sections at $\sqrt{s} = 2.76$ TeV and our previous measurements at $\sqrt{s} = 7$ TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307

The Modified Resisted Internal Rotation Test for Detection of Gluteal Tendon Tears

Greater trochanteric pain syndrome (GTPS) has received increasing attention in recent years. Most patients with GTPS present with trochanteric bursitis and respond to nonoperative treatment. However, a subset of patients may have persistent lateral hip pain or recalcitrant GTPS resulting from an undiagnosed gluteal tendon tear. Recalcitrant GTPS may be a debilitating condition in this patient subset. There is a need for an accurate and evidence-based physical examination maneuver to aid in earlier diagnosis of gluteal tendon tears and timely intervention in these patients. Most studies evaluating gluteal tendinopathy fail to assess surgical indications and instead focus on identifying trochanteric bursitis, which may or may not require surgical treatment. The modified resisted internal rotation test has been used in our practice to detect gluteus medius tendon tears in the recalcitrant GTPS patient population. Fundamental anatomic, biomechanical, electromyographic, and clinical data have been reviewed to make this an evidence-based clinical test for early detection of this pathology

Concomitant Arthroscopy With Labral Reconstruction and Periacetabular Osteotomy for Hip Dysplasia

In the setting of true hip dysplasia, the high prevalence of intra-articular pathology may lead to recurrent symptoms and failure after periacetabular osteotomy (PAO). Femoral neck osteochondroplasty, microfracture, removal of loose bodies, and labral repair are examples of procedures that are performed with concomitant arthroscopy. When damage to the labrum is too severe to repair, reconstruction instead of extensive debridement before PAO can be more effective in restoring the labral seal to maintain joint lubrication and chondral protection. This Technical Note describes a method for concomitant hip arthroscopy with circumferential labral reconstruction with allograft and PAO

Forget the Greater Trochanter! Hip Joint Access With the 12 O’clock Portal in Hip Arthroscopy

Most surgeons rely on the greater trochanter as the reference point to establish the anterolateral portal. Nevertheless, we believe that the anterosuperior iliac spine is a more reliable landmark. Unlike the greater trochanter, it is unaffected by leg rotation and is more easily identified by palpation. Abiding by the central tenet of medicine to “do no harm,” the technique described herein presents in detail the concept of the 12 o’clock portal placement, a hip joint access method based on identifying specific anatomic points under fluoroscopy and by palpation. To accomplish this goal, this Technical Note presents a step-by-step approach, including tips and pearls for patient positioning and fluoroscopic guidance. We believe this method ensures a reproducible and safe way to start hip arthroscopy in the supine position

Osteochondral Allograft Implantation Using the Smith–Peterson (Anterior) Approach for Chondral Lesions of the Femoral Head

Management of chondral lesions of the femoral head can be challenging. Previously described approaches include arthroscopic surgery for small lesions and open surgical dislocation for larger lesions. In 2001, Ganz popularized the trochanteric flip osteotomy for surgical dislocation, and this remains the workhorse for treatment of large chondral lesions. However, by using a Smith–Peterson (direct anterior) approach and a femoral head allograft, large lesions may be treated while avoiding both trochanteric osteotomy and donor-site morbidity. We present our technique using a Smith–Peterson approach and osteochondral implantation of fresh femoral head allograft for surgical treatment of a femoral head chondral lesion

Fresh Femoral Head Osteochondral Allograft Transplantation for Treating Osteochondritis Dissecans of the Femoral Head

Treatment options for the management of osteochondritis dissecans (OCD) lesions of the femoral head are limited. Although arthroscopic surgery of the hip can treat a variety of intra- and extra-articular pathologies, an OCD lesion located at the superior and medial zone of the femoral head is often difficult to access and cannot be adequately treated arthroscopically. The use of fresh-stored osteochondral allograft allows surgeons to both avoid donor-site morbidity and treat lesions of a larger surface area. We present our technique for surgical treatment of a femoral head OCD lesion with open surgical dislocation of the hip through stepped trochanteric osteotomy and osteochondral transplantation of fresh-stored femoral head allograft

Capsular Management of the Hip During Arthroscopic Acetabular Chondral Resurfacing: Pearls, Pitfalls, and Optimal Surgical Technique

Treatment of hip joint chondral damage is a well-recognized aspect of the arthroscopic management of femoroacetabular impingement syndrome. Hip chondral resurfacing has evolved from microfracture to different forms of cartilage grafting, all with variable long-term outcomes. Recent literature has focused on techniques using different cartilage sources (native and synthetic products) that are available for clinicians to choose from during hip arthroscopy. None of the published reports on cartilage grafts have commented on hip joint capsular management as part of the procedure. This is likely because of the increased difficulty of capsular closure in the dry arthroscopic environment required for graft stabilization. However, potential iatrogenic hip instability induced by an unrepaired interportal capsulotomy can be detrimental to the existing joint architecture and possibly to the cartilage graft. This article presents a step-by-step approach, including tips and pearls, for capsular closure during arthroscopic acetabular chondral resurfacing with BioCartilage (Arthrex, Naples, FL). This method is a safe and reproducible way to close the joint capsule during chondral resurfacing in patients undergoing hip preservation that can potentially enhance the chances of a successful outcome

Arthroscopic Triple Reconstruction in the Hip Joint: Restoration of Soft-Tissue Stabilizers in Revision Surgery for Gross Instability

Gross hip instability in an active adult with previous normal hip anatomy is usually due to disruption of the static stabilizers of the hip joint. Although such a disruption can result from a high-grade injury, it can be iatrogenic after previous hip arthroscopy. The patient may present with a painful limp and recurrent subluxation sensation in the affected hip joint. Revision hip arthroscopy in this scenario is generally complicated, and it is not uncommon for all the soft-tissue stabilizers to be compromised. The labrum, ligamentum teres (LT), and capsule of the hip joint are often so damaged that reparation is not an option. Reconstruction of the torn LT is an established method to add secondary stability while addressing the labral pathology in the hip joint with microinstability. Concomitant reconstruction of all the static restraints has yet to be described addressing triple instability. This Technical Note presents a stepwise approach, including tips and pearls, for arthroscopic triple reconstruction of the labrum, LT, and capsule. We believe this method is a safe and reproducible way to effectively treat gross hip instability in young patients

Microfracture in Hip Arthroscopy. Keep It Simple!

Despite all the advances in hip arthroscopy, microfracture is still the workhorse for treating focal and full-thickness cartilage lesions. The success of this treatment is owed to its reliability and simplicity. Given the structure of the hip joint, however, there are challenges to this procedure using a conventional microfracture pick. This note presents our current and preferred microfracture technique using a curve drill guide and flexible drill. This method offers greater range of access to different regions of the joint with ease, thus ensuring a reproducible and quicker procedure with less risk

Hip Labral Augmentation With Tibialis Anterior Tendon Allograft Using the Knotless Pull-Through Technique

The importance of the labrum in the biomechanics of the hip joint is well documented. Labral tears are the most common pathology in patients undergoing hip arthroscopy and therefore appropriate labral management is vital. Labral preservation has been advocated as a superior alternative to labral excision in terms of clinical outcomes. While reconstruction of the labrum is recommended for irreparable tears, labral augmentation is a viable alternative for labral function restoration under certain indications. This Technical Note will describe a method for arthroscopic hip labral augmentation using an anterior tibialis tendon allograft and the pull-through technique