Optimal hip capsular release for joint exposure in hip resurfacing via the direct anterior approach.

Aims: Surgical approaches that claim to be minimally invasive, such as the direct anterior approach (DAA), are reported to have a clinical advantage, but are technically challenging and may create more injury to the soft-tissues during joint exposure. Our aim was to quantify the effect of soft-tissue releases on the joint torque and femoral mobility during joint exposure for hip resurfacing performed via the DAA. Methods: Nine fresh-frozen hip joints from five pelvis to mid-tibia cadaveric specimens were approached using the DAA. A custom fixture consisting of a six-axis force/torque sensor and motion sensor was attached to tibial diaphysis to measure manually applied torques and joint angles by the surgeon. Following dislocation, the torques generated to visualize the acetabulum and proximal femur were assessed after sequential release of the joint capsule and short external rotators. Results: Following initial exposure, the ischiofemoral ligament (7 to 8 o'clock) was the largest restrictor of exposure of the acetabulum, contributing to a mean 25% of overall external rotational restraint. The ischiofemoral ligament (10 to 12 o'clock) was the largest restrictor of exposure of the proximal femur, contributing to 25% of overall extension restraint. Releasing the short external rotators had minimal contribution in torque generated during joint exposure (≤ 5%). Conclusion: Adequate exposure of both proximal femur and acetabulum may be achieved with minimal torque by performing a full proximal circumferential capsulotomy while preserving short external rotators. The joint torque generated and exposure achieved is dependent on patient factors; therefore, some cases may necessitate further releases.

Editorial Commentary: In Patients With Hip-Spine Syndrome, a Single Simple Solution May Not Apply: Occam's Razor Becomes Blunt.

The importance of hip-spine syndrome in a nonarthritic population, in which patients present with coexisting symptoms in both the hip and lumbar spine, is becoming more clear. Several studies have shown inferior outcomes in patients undergoing treatment for femoral acetabular impingement syndrome with coexisting spinal symptoms. The most important factor when treating HSS patients is understanding each patient's pathology. A history and physical examination with provocative tests for spinal and hip pathology often provide the answer. Routine standing and seated lateral radiographs are required to assess spinopelvic mobility. If the cause of pain is unclear, diagnostic intra-articular hip injections with local anesthetic and further imaging of the lumbar spine are recommended. In patients with degenerative spine disease with neural impingement, these symptoms may persist after hip arthroscopy, particularly if not improved by intra-articular injections. Patients should be appropriately counseled. If hip symptoms predominate, treatment of femoroacetabular impingement syndrome results in improved outcomes, even with coexisting neural impingement. If spine symptoms predominate, referral to an appropriate specialist may be required. In patients with HSS, Occam's razor becomes blunt; thus, a single simple solution may not apply, and we may need to consider treating each pathology separately.

Hip arthroscopy for femoroacetabular impingement.

The purpose of this article is to give a general overview of femoroacetabular impingement (FAI) and how it could be treated arthroscopically, with some details about indications, the procedure itself and some of the complications associated with the surgery.FAI is a dynamic condition of the hip that can be a source of pain and disability and could potentially lead to arthritis.When symptomatic, and if conservative treatment fails, FAI can be addressed surgically.The goal of surgical treatment for FAI is to recreate the spherical contour of the femoral head, improve femoral offset, normalize coverage of the acetabulum, repair/reconstruct chondral damage and repair/reconstruct the labrum to restore normal mechanics and joint sealing.Advances in equipment and technique have contributed to an increase in the number of hip arthroscopy procedures performed worldwide and have made it one of the more common treatment options for symptomatic FAI.Hip arthroscopy is a procedure with an extremely steep and long learning curve. Cite this article: EFORT Open Rev 2018;3:121-129. DOI: 10.1302/2058-5241.3.170041.

The hip-spine connection: understanding its importance in the treatment of hip pathology.

EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Discuss the kinematic relationship between the hip and lumbar spine. 2. Explain the innervation of the hip and lumbar spine and how they relate to one another. 3. Recognize the effect of hip disease on the lumbar spine in an athletic population, prior to the onset of degenerative changes. 4. Describe an algorithm for diagnosis and treatment of patients who present with concomitant hip and lumbar spine pain. The hip and lumbar spine are closely related and can create similar patterns of pain and dysfunction. Diagnosis and treatment of hip and spine-related conditions can be challenging due to symptom overlap. Successful evaluation and treatment of hip and lumbar spine conditions requires a thorough understanding the hip-spine connection. Historically the hip-spine connection has been considered in the context of arthrosis; however, the hip-spine connection also needs to be considered in a younger athletic population. The purpose of this review is to describe the hip-spine connection, discuss the clinical implications of this connection, and offer an approach to diagnosis and treatment.

Open surgical dislocation versus arthroscopy for femoroacetabular impingement: a comparison of clinical outcomes.

PURPOSE: Over the last decade, the surgical treatment of femoroacetabular impingement (FAI) has evolved as surgical techniques through arthroscopy, open surgical dislocation, and combined approaches have been developed. The purpose of this systematic review was to evaluate and compare the clinical results of available surgical approaches for FAI. METHODS: A review of the literature was performed through the PubMed database and related articles' reference lists. Inclusion criteria were (1) all patients treated for FAI, (2) Level I, II, III, or IV study design, and (3) written in the English language. Case reports and studies involving patients with acetabular dysplasia were excluded. RESULTS: Overall, 1,299 articles fit our keyword search criteria. Of these, 26 articles reported clinical outcomes, using 3 surgical modalities: open surgical dislocation, arthroscopic, and combined approaches. In compiling the data in these articles, we analyzed the outcomes of a total 1,462 hips in 1,409 patients. The most published surgical method was arthroscopy, which included 62% of the patients. Labral repair was performed more frequently in open surgical dislocation (45%) and combined approach (41%) procedures than in arthroscopies (23%). Mean improvement in the modified Harris hip score after surgery was 26.4 for arthroscopy, 20.5 for open surgical dislocation, and 12.3 for the combined approach. A higher rate of return to sport was reported for arthroscopy in professional athletes than for open surgical dislocation. Overall complication rates were 1.7% for the arthroscopic group, 9.2% for the open surgical dislocation group, and 16% in the combined approach group. CONCLUSIONS: All 3 surgical approaches led to consistent improvements in patient outcomes. Because a wide variety of subjective hip questionnaires were used, direct comparisons could not be made in many cases, and none of the approaches could be clearly shown to be superior to the others. However, it seems that, overall, the arthroscopic method had the lowest complication and fastest rehabilitation rate.

Partial-thickness tears of the gluteus medius: rationale and technique for trans-tendinous endoscopic repair.

Tears in the gluteus medius and minimus tendons, often misdiagnosed as trochanteric bursitis, have recently emerged as an important cause of recalcitrant greater trochanter pain syndrome. Advances in endoscopic surgery of the hip have created opportunities to better evaluate and treat pathology in the peritrochanteric compartment. We reviewed the literature on trochanteric pain syndrome and gluteus medius tendon injuries. Existing techniques for endoscopic and open gluteus tendon repair and potential challenges in restoration of abductor function were analyzed. Partial-thickness undersurface tears of the gluteus medius were identified as a common pathologic entity. Although these tears are otherwise analogous to partial-thickness tears of the rotator cuff, the lack of arthroscopic access to the deep side of the gluteus medius tendon represents a unique technical challenge. To address the difficulty in visualizing and thus repairing undersurface tears of the gluteus medius, a novel endoscopic trans-tendinous repair technique was developed. The purposes of this article are to review the anatomy, pathology, and existing repair techniques of gluteus medius tendon tears and to describe the rationale and surgical steps for endoscopic trans-tendinous repair.

Conformation of acetate derivatives of sugars and other cyclic alcohols. Crystal structures, NMR studies, and molecular mechanics calculations of acetates. When is the exocyclic C-O bond eclipsed?

[reaction: see text] A study of published crystal structures (of O-acetylated sugars for the most part) suggests that the exocyclic C-O bond in acetate esters of cyclic alcohols intrinsically prefers a staggered conformation, although the eclipsed conformation is only slightly less stable. When the acetate is flanked by two equatorial substituents the preferred conformation is close to eclipsed. Over 1500 C-OAc bonds have been analyzed. Diagnostic NMR criteria for torsion angles and MM3 calculations are reported and confirm these conclusions.

Structure, modelling and dynamic behaviour of aza- and azaoxamacrocyclic ligands derived from (R,R)-1,2-diaminocyclohexane.

Investigations into the conformational behaviour of macrocyclic ligands 5 and 6 derived from (R,R)-1,2-diaminocyclohexane have been undertaken using molecular modelling, single crystal X-ray diffraction and variable temperature 1H NMR spectroscopy. These have revealed that the lowest energy conformers in both cases do not possess the expected C2-element of symmetry, which can only be accessed at higher temperatures. Instead both molecules exist as C1-conformers at room temperature and in the solid state. In solution a range of dynamic exchange processes is observed which result, in part from the inherent strain in these fused bicyclic systems. An unexpected but characteristic feature of the C1-symmetric conformers is highlighted by the presence of a signal at unexpectedly low field in their 1H NMR spectra due to the interaction of two of the sulfonyl oxygen atoms with one of the bridgehead hydrogen atoms.