The hip arthroscopy develops quickly in the past 20 years. Its use in the diagnosis and treatment of the hip injury get more notably. Many of pathologic conditions previously unrecognized through X-ray, CT or MRI have been diagnosed correctly under hip arthroscopy. The technology has become gradually a golden standard to confirm the hip discords. In the present, the examining path of the hip arthroscopy contains mainly the outside path, the anterior path, the outside-posterior path. The application range of the hip arthroscopy includes the management of labral tears, the femoroacetabular impingement, the ligamentum tear injuries, the chondral lesions, the synovical abnormalities, the intra-articular infection, the loose bodies in the joint etc. The hip arthroscopy is a comprehensive technology. Its superiority can be reflect well if the doctors are familiar with the indication, the contraindication and the operation procedure. And also the thorough physical examination and imaging examination should be made before operation, as well as reasonable and effective postoperative function training should be conducted.
Arthroscopy ; methods ; Hip Injuries ; surgery ; Hip Joint ; surgery ; Humans

BACKGROUNDThe acetabular teardrop is often used to guide acetabular component placement in total hip arthroplasty (THA). Placing the lower acetabular component aspect at the same level as the lower teardrop edge was assumed to restore the hip center of rotation. Here we radiographically analyzed the relationship between cup center and normal contralateral acetabulum center height on unilateral THA using this placement method.

METHODSA total of 106 unilateral THA cases with normal contralateral acetabula were reviewed and the vertical and horizontal distances in relation to the lower acetabular teardrop edge from both hip joint centers, cup inclination, and anteversion were measured radiographically. The paired t-test was used to compare left and right hip center heights. Scatter plots and Pearson's correlation coefficients were used to evaluate differences in hip center heights, cup anteversion, inclination angles, and medialized cup center distance compared to the contralateral hip joint.

RESULTSCup center height was significantly greater (P < 0.01) than contralateral hip joint center height (93.4% in the 0-5 mm range, 6.6% >5 mm). There was a weak correlation between hip center height difference and inclination (r = 0.376, P < 0.01) and between difference and anteversion (r = 0.310, P < 0.01) but no correlation between difference and outer cup diameter (r = 0.184, P = 0.058) or difference and medialized cup center distance (r = -0.098, P = 0.318).

CONCLUSIONSAlthough this method did not exactly replicate anatomic hip center height, the clinical significance of cup center height and anatomic hip center height differences is negligible. This acetabular component placement method has high simplicity, reliability, and stability.

Fracture Fixation, Internal ; Hip Dislocation ; surgery ; Hip Fractures ; surgery ; Hip Joint ; surgery ; Humans ; Male ; Young Adult

OBJECTIVE: To explore the tensile mechanics and anatomical characteristics of the posterior hip capsule, and provide biomechanical and anatomical evidence for capsule repair in total hip replacement. METHODS: Six bone-capsule-bone specimens were obtained from posterior hip joint of fresh frozen cadavers. The maximum strain, load, elastic modulus and load strain curves of the capsule ligament complex specimens were recorded by Instron Universal Material Testing Machine. Twelve cadaveric hip specimens were dissected to the capsule. The tensile strain of normal capsule and conventionally reconstructed capsule at 90 degrees of hip flexion were documented. The suture area of the posterior capsule was divided into nine sections, and the thicknessof different sections was measured and compared. Posterior capsule of the cadavers was repaired in conventionally way and anatomical way separately and simulated rehabilitation was conducted. The effect of rehabilitation on the repaired capsule was observed. RESULTS: The load-strain curve of capsule ligament complex conforms to rheological and viscoelastic characteristics. The maximum tensile strain of the complex was (39.21±5.23)%, the maximum load was (142.06± 34.15) N, the tensile strength was (1.65±0.38) MPa, and the elastic modulus is (14.23±5.62) MPa. At 90 ° hip flexion, the tensile strain of repaired capsule was higher than that of normal capsule, and the difference was statistically significant (< 0.05). Tensile strain of conventionally reconstructed capsule is:upper part (37.0±4.9)%, middle part ( 53.3±1.1)%, lower part (68.3±6.2)%, tensile strain of normal capsule is:upper part (17.0±2.6)%, middle part (24.1±1.4)%, lower part (26.0± 4.3)% . The thickness of the posterior joint capsulein different sections is statistically significant (<0.05), and capsule at 0.5cm proximal to the femoral insertion is suitable for suture. There the average thickness of capsule is:upper part (3.48 ± 0.11) mm, middle part (2.36 ± 0.09) mm, lower part (1. 59±0.24) mm. The posterior inferior joint capsule is thinnest at (1.42± 0.02) cm proximal to the femoral insertion, and sutures should be avoided here. After simulating rehabilitation, avulsion occurred in the lower part of the posterior capsule repaired conventionally (10/12), and the anatomically repaired capsule remained intact. CONCLUSION The lower part of conventionally repaired capsule is overstretched and tends to fail. Anatomically repaired capsule conforms to tensile mechanics and is helpful to reduce the failure rate of repair.
Arthroplasty, Replacement, Hip ; Biomechanical Phenomena ; Femur ; Hip Joint ; surgery ; Humans ; Joint Capsule ; surgery ; Tensile Strength

OBJECTIVE: To investigate whether the anteversion angle of acetabular prosthesis can be evaluated on the anteroposterior X-ray film of common double hip joint. METHODS: Total 32 patients(41 hips) after total hip arthroplasty were selected, including 18 males and 14 females, aged(66.2±4.1) years. All patients completed the positive X-ray film of both hips and plain CT scan of pelvis after operation. Acetabular anteversion was measured by plain CT scan of pelvis, and measured by Saka and other measurement formulas on X-ray film. RESULTS: The acetabular anteversion measured by X-ray film was(16.2±5.0)° and that measured by CT was (31.8±9.7)°(P=0.00). In addition, there was a significant linear correlation between X-ray film and CT(Pearson correlation coefficient (r=0.84, P=0.00). CONCLUSION CT can accurately measure the acetabular anteversion, but it has obvious disadvantages, such as large radiation, high cost, phantom CT artifact and so on. Although Saka measurement formula can not directly obtain the accurate acetabular anteversion as CT measurement, it has a high correlation with the acetabular anteversion measured by CT. Therefore, the method proposed in this study can also preliminarily evaluate the acetabular anteversion.
Acetabulum/surgery* ; Arthroplasty, Replacement, Hip/methods* ; Female ; Hip Joint/surgery* ; Hip Prosthesis ; Humans ; Male ; Pelvis

OBJECTIVE: To investigate how to place the anteversion of acetabular prosthesis more reasonably in patients with lumbar degenerative kyphosis. METHODS: A total of 122 patients with degenerative kyphosis of lumbar spine who underwent total hip arthroplasty from December 2017 to October 2019 were included and divided into experimental group and control group, 61 cases in each group. In experimental group, there were 25 males and 36 females, with a median age of 67.0 years;the median course of disease was 46.0 months;the functional pelvic plane with acetabular anteversion was set according to different types of pelvic anterior plane bracket. In control group, there were 27 males and 34 females, with a median age of 67.0 years;the median course was 42.0 months;in control group, the anteversion was set by the traditional method. The patients were followed up for 3 months. The operation time and blood loss were recorded. The incidence of infection and dislocation within 3 months was counted. Harris score before and 3 months after operation was recorded. Functional anteversion angle of standing position was measured 3 months after operation. RESULTS: Compared with control group, there was no difference in operation time and blood loss between the two groups (P=0.918, 0.381);there was no infection between two groups within 3 months after operation;there was 1 case of hip joint dislocation in the control group and no dislocation in experimental group. There was no significant difference in Harris score before and after operation. Three months later, reexamination of pelvic standing radiographs showed that the number of patients with functional anteversion of acetabular prosthesis outside the safe area was less in experimental group thanin control group ( CONCLUSION According to the preoperative evaluation and classification of patients, better functional anteversion of acetabular prosthesis can be obtained with the help of pelvic anterior plane reference bracket in hip arthroplasty with lumbar degenerative kyphosis.
Acetabulum/surgery* ; Aged ; Arthroplasty, Replacement, Hip ; Female ; Hip Dislocation/surgery* ; Hip Joint ; Hip Prosthesis ; Humans ; Kyphosis ; Male ; Retrospective Studies

Arthroplasty, Replacement, Hip ; adverse effects ; Hemangiosarcoma ; diagnosis ; Hip Joint ; pathology ; surgery ; Hip Prosthesis ; Humans

Since the concept of "safe area" put forward by Lewinnek, it has been widely recognized. While in recent years, many scholars have found that even if the acetabular prosthesis was placed on the "safe area", there were still many unexplained dislocation after total hip arthroplasty. And scholars began to question whether the "safe area" is really suitable for all patients. Spinal degeneration, deformity, lumbar fusion, etc. will lead to spine sagittal imbalance and changes in pelvic activity, which could lead to changes in acetabular orientation, and ultimately lead to edge loading, wear, impact, and even dislocation after total hip replacement. From the perspective of wear, impact and dislocation, it is determined by the functional positioning of the acetabular cup, not the anatomical positioning. The anatomical positioning and functional positioning of the neutral pelvic acetabular cup in the standing position can be considered equivalent. For pelvic rotation more than 20°, functional placement needs to be considered. In recent years, as the understanding of the internal relationship between the spine-pelvis-hip joint has become more and more profound, some scholars further classify the hip-spine relationship according to whether the spine is stiff or deformed, and propose corresponding acetabulums according to different types of hip-spine relationships The function of placement, so as to achieve a stable artificial hip joint. Therefore, it is of great significance to fully assess whether the patient's sagittal plane is balanced before surgery to guide artificial hip replacement surgery.
Acetabulum/surgery* ; Arthroplasty, Replacement, Hip ; Hip Joint ; Hip Prosthesis ; Humans ; Spine

The assistant artificial hip joint (AAHJ) is a new impermanent hip support implanted in the body. It is used for treatment of ischemic necrosis of the femoral head at the early stage. It reserves the natural femoral head, increases its containment and decreases its load, thus makes the recovery of the necrosed femoral head. The AAHJ's moving axis center is the same as that of the femoral head. Therefore, the moving range of the hip joint is very close to the normal postoperatively. The patient can walk with loading in 3 weeks after the surgical operation, and can regain his (or her) daily work and life in 2 to 3 months of the operation. The AAHJ's structure is simple and the price is cheap.
Arthroplasty, Replacement, Hip ; instrumentation ; Femur Head Necrosis ; surgery ; Hip Joint ; surgery ; Hip Prosthesis ; Humans ; Prosthesis Design ; Recovery of Function ; Treatment Outcome

Arthroplasty, Replacement, Hip ; Female ; Hip Joint/surgery* ; Hip Prosthesis ; Humans ; Male ; Sex Characteristics ; Spondylitis, Ankylosing/surgery* ; Treatment Outcome