Osteonecrosis of the femoral head is a destructive joint disease requiring early hip arthroplasty. The polyethylene-metal design using a 22-mm femoral head component, introduced by Charnley in 1950, has been widely used for over half a century. Since then, different materials with the capacity to minimize friction between bearing surfaces and various cement or cementless insert fixations have been developed. Although the outcome of second and third generation designs using better bearing materials and technologies has been favorable, less favorable results are seen with total hip arthroplasty in young patients with osteonecrosis. Selection of appropriate materials for hip arthroplasty is important for any potential revisions that might become inevitable due to the limited durability of a prosthetic hip joint. Alternative hip arthroplasties, which include hemiresurfacing arthroplasty and bipolar hemiarthroplasty, have not been found to have acceptable outcomes. Metal-on-metal resurfacing has recently been suggested as a feasible option for young patients with extra physical demands; however, concerns about complications such as hypersensitivity reaction or pseudotumor formation on metal bearings have emerged. To ensure successful long-term outcomes in hip arthroplasty, factors such as insert stabilization and surfaces with less friction are essential. Understanding these aspects in arthroplasty is important to selection of proper materials and to making appropriate decisions for patients with osteonecrosis of the femoral head.

Subchondral bony cyst, large solitary or multiple cysts in acetabular dome usually exacerbate progression to degenerative osteoarthritis in the hip joint. But it can be treated through arthroscopic intervention. We report two cases that treated by arthroscopic curettage and bone graft for subchondral bony cysts in early osteoarthritis of the hip joint, and it may delay progression to moderate osteoarthritis.

The causes of osteolytic lesions found in radiological examinations are not quite certain. Therefore, to determine the appropriate treatment method, various approaches and analyzes are required to find the real cause. Hyperparathyroidism is one of the diseases which forms osteolytic bone lesions so-called brown tumor. A 55-year-old woman who had painful osteolytic bone lesions in both hip joint areas was diagnosed as parathyroid carcinoma after serial work-up. She underwent parathyroidectomy and follow-up imaging showed a decrease in brown tumor size and bone consolidation in the subchondral bone destruction area. Proper evaluation of osteolytic bone lesions helps to avoid unnecessary operative treatments and the first choice for the treatment of osteolytic bone lesions caused by parathyroid carcinoma is parathyroidectomy.

Purpose: To identify potential differences in interportal capsulotomy size and cross-sectional area (CSA) using the anterolateral portal (ALP) and either the: (i) standard anterior portal (SAP) or (ii) modified anterior portal (MAP).
Materials and Methods: Ten cadaveric hemi pelvis specimens were included. A standard arthroscopic ALP was created. Hips were randomized to SAP (n=5) or MAP (n=5) groups. The spinal needle was placed at the center of the anterior triangle or directly adjacent to the ALP in the SAP and MAP groups, respectively. A capsulotomy was created by inserting the knife through the SAP or MAP. The length and width of each capsulotomy was measured using digital calipers under direct visualization. The CSA and length of the capsulotomy as a percentage of total iliofemoral ligament (IFL) side-to-side width were calculated.
Results: There were no differences in mean cadaveric age, weight or IFL dimensions between the groups. Capsulotomy CSA was significantly larger in the SAP group compared with the MAP group (SAP 2.16±0.64 cm² vs. MAP 0.65±0.17 cm², P=0.008). Capsulotomy length as a percentage of total IFL width was significantly longer in the SAP group compared with the MAP group (SAP 74.2±14.1% vs. MAP 32.4±3.7%, P=0.008).
Conclusion: The CSA of the capsulotomy and the percentage of the total IFL width disrupted are significantly smaller when the interportal capsulotomy is performed between the ALP and MAP portals, compared to the one created between the ALP and SAP. Surgeons should be aware of this fact when performing hip arthroscopy.

Purpose: The aim of this study was to evaluate the short-term outcome of physiotherapy in patients with acetabular labral tears and to assess the effectiveness of physiotherapy according to the severity of the labral tear.
Materials and Methods: Thirty-five patients who underwent physiotherapy for treatment of symptomatic acetabular labral tears were enrolled. We evaluated the severity of the acetabular labral tears, which were classified based on the Czerny classification system using 3-T MRI. Clinical findings of microinstability and extra-articular pathologies of the hip joint were also examined. The International Hip Outcome Tool 12 (iHOT12) was use for evaluation of outcome scores pre- and post-intervention.
Results: The mean iHOT12 score showed significant improvement from 44.0 to 73.6 in 4.7 months. Compared with pre-intervention scores, significantly higher post-intervention iHOT12 scores were observed for Czerny stages I and II tears (all P<0.01). However, no significant difference was observed between pre-intervention and post-intervention iHOT12 scores for stage III tears (P=0.061). In addition, seven patients (20.0%) had positive microinstability findings and 22 patients (62.9%) had findings of extra-articular pathologies. Of the 35 patients, eight patients (22.9%) underwent surgical treatment after failure of conservative management; four of these patients had Czerny stage III tears.
Conclusion: The iHOT12 score of patients with acetabular labral tears was significantly improved by physiotherapy in the short-term period. Improvement of the clinical score by physiotherapy may be poor in patients with severe acetabular labral tears. Determining the severity of acetabular labral tears can be useful in determining treatment strategies.

The purpose of this case report and review of the literature is to provide documentation on periprosthetic hip joint infection with Flavonifractor plautii (formerly known as Eubacterium plautii), a strictly anaerobic bacterium, and to report on a successful pathway for management including staged surgical revisions and extended antibiotic therapy. A systematic review of the literature was conducted, which identified this case as only the fifth documented case of human infection with this organism; as a result, conduct of further research is warranted, based on the paucity of reports in the literature addressing anaerobic periprosthetic joint infection.

Purpose: This study attempted to evaluate the pattern of change of the pain after total hip arthroplasty (THA) and to confirm the effect of periarticular multimodal drug injection (PMDI) on controlling the early postoperative pain.
Materials and Methods: Of the total patients who underwent primary THA at our hospital because of osteonecrosis of the femoral head from March to October 2008, 60 patients were enrolled in this study. The subjects were divided into three groups. Groups 1 & 2 received periarticular injection. Group 1 included the patients who were injected with a combination of opioid, long-acting local anesthetics, a non-steroidal anti-inflammatory drug and epinephrine. Group 2 received a combination of morphine and ropivacaine and group 3 was not injected with any analgesics. The visual analogue scale (VAS) at 4 hours, 8 hours, 12 hours, 24 hours, 2 days, 3 days, 5 days, 14 days and 1 month after surgery, the frequency that patients pushed the self-controlled pain medication machine for 2 days after surgery and the amount of clonac that was injected according to the needs of the patients were used as objective measures.
Results: The VAS score at postoperative 4 hours to 3 days among the groups showed a significant difference (P<0.05), but the VAS scores at postoperative 5 days to 1 month among the groups showed no significant difference (P>0.05). The frequency of pushing the self-controlled pain medication machine among the groups and the amount of clonac according to the needs of the patients among the groups showed that there were significant decreases at the operation day, the postoperative 1, 2 day and the 3 days (P<0.05).
Conclusion: PMDI has a significant effect on controlling the early postoperative pain after THA.

Ganglions commonly occur on the hand, wrist, knee, ankle and foot, with occasional development around the hip joint. Ganglion in the acetabular fossa is rare. We present a case of a ganglion in the acetabular fossa of the hip with treatment.

The ball and socket structure of the hip joint allows a wide range of motion that is exceeded in no other joint of the body except the shoulder. At the same time, a remarkable degree of stability is provided by the close fit of the femoral head into the acetabulum and its deepening lip, the glenoid labrum, and by the support of the strongest capsular ligaments and the thickest musculature of the body. Of all the joints, the hip is most deeply situated. This relative inaccessibility increases the difficulty of diagnosing hip lesions, rendering thorough operative exposure of the joint arduous. Precise knowledge about the anatomy of the hip joint and its surrounding structures help orthopaedic surgeons diagnose and treat various diseases and trauma around the hip joint.
An understanding of the biomechanics of the hip is vital to advancing the diagnosis and treatment of many pathologic conditions. Benefits from advances in hip biomechanics include the evaluation of joint function, the development of therapeutic programs for treatment of joint problems, procedures for planning reconstructive surgeries, and the design and development of total hip prostheses. Biomechanical principles also provide a valuable perspective to our understanding of the mechanism of injury to the hip, to femoroacetabular impingement, and to the etiology of degenerative hip disease.