Objective To evaluate the strength of polyethylene l inercement interface when cementing a new linerinto a fixed acetabular cup in revision. Methods Twenty-five pairs of metal acetabular cups with polyethylene l iners were randomly divided into 5 groups: 1 group with standard locking device as control group (group A), other l iners were cemented into acetabular cups as 4 experimental groups. According to different intersection angles of metal acetabular cups with polyethylene liners and the polyethylene l iners with or without metal ball, the 4 experimental groups were no ball 0° group (group B), 0° group (group C), 10° group (group D), and 20° group (group E), metal acetabular cups intersected with polyethylene liners without metal ball in group B, with metal ball in groups C, D, and E, respectively. The lever-out biomechanical test reproduced in vivo failure mechanism was then performed to evaluate the lever-out failure strength of l iner-cement-metalcup interface. Results The values of l iver-out failure force were (626.68 ± 206.12), (915.04 ± 197.49), (449.02 ± 119.78),(814.68 ± 53.89), and (1 033.05 ± 226.44) N in groups A, B, C, D, and E, respectively, showing significant differences forcomparison among groups (F=8.989，P=0.000). The values of l iver-out failure force in groups B and E were significantlyhigher than that in group A (P lt; 0.05), but no significant difference was found between groups C, D and group A (P gt; 0.05).Conclusion Cementation of polyethylene l iner into a malposition shell meeting within 20° can provide enough fixed strength.
Objective To evaluate the therapeutic outcome of artificial total hip arthroplasty (THA) with collum femoris preserving for hip joint desease in young and middle-aged patients. Methods From March 2002 to March 2005, 26 cases (31 hips) of hip joint disease were treated with artificial THA with collum femoris preserving, including 19 males (23 hips)and 7 females (8 hips) and aged 32-48 years with an average of 37 years. In 31 hips, 17 left hips and 14 right hips were involved. There were 9 cases of osteoarthritis of the hip joint caused by avascular necrosis of the femoral head (ANFH), 7 cases of ANFH, 3 cases of femoral head necrosis caused by dysplasia of acetabular, 1 case of osteoarthritis of the hip joint caused by ankylosing spondyl itis, and 2 cases of rheumatoid arthritis; the course of disease was 2-11 years (5.6 years on average). Two cases of femoral neck fracture (Garden IV), and 2 cases of non-union femoral neck fractures (1 for Garden III and 1 for Garden IV), the course of disease was 5 days, 24 months, and 26 months. The prime symptoms were pain, difficult walk and l imp. All patients were taken X-ray to exclude osteoporosis. Results The right distal femur prosthesis of a bilateral patient cracked owing to excessive amputation of collum femoris, and fracture healed after symptomatic treatment. All the incisions healed by first intention and no compl ications occurred. All patients were followed up for 4-7 years, with an average of 5.6 years. One case had poor hip function because he did not follow rehabil itation procedure, and the others achieved good outcome with normal gait. One case complained of persistent pain 6 months after operation, and was rel ieved by administration of some non-steroidal antiinflammatory drugs and anti-osteoporosis drugs 6 months later. The X-ray films after operation and at last follow up showed good location of prosthesis and no bone resorption. Harris score at last follow-up was 91.31 ± 0.77, and it was significantly higher than that before operation (50.88 ± 0.90), (P lt; 0.05). The excellent and good rate was 93.5% (excellent in 11 hips, good in 18 hips, and fair in 2 hips). Conclusion Artificial THA with collum femoris preserving can retain more bone, be easier for revision, and has an excellent outcome.
Objective To investigate the operative methods, cl inical outcomes and compl ications of total hi p arthroplasty (THA) in the treatment of patient with hi p joint flexion rigidity due to ankylosing spondyl itis (AS). Methods From May 1992 to July 2004, 56 patients (32 left hips and 39 right hips) with AS received THA through a modified anterolateral approach, including 52 males (67 hips) and 4 females (4 hips) aged 17-48 years with an average of 35.5 years. All the hips were ankylosed in (43.1 ± 7.2)° of flexion and 15 patients had bilaterally ankylosed hips. Preoperatively, Harris hip score was (42.6 ± 5.3) points and all the hips were classified as stage IV according to the standard of American College of Rheumatology (ACR). And the course of disease was 3-11 years. Results Intraoperatively, 1 patient suffering from proximal femur fracture due to severe osteoporosis was treated with titanium wire fixation, and the fracture was healed 6 weeks later. All the patients were followed up for 3-15 years (average 5.3 years). Postoperatively, 1 patient (1 hip) got subcutaneous soft tissue infection at 8 days, 1 patient (1 hip) got wound disunion at 11 days, 2 patients (2 hips) got infection at 11 months and 3 years, respectively. All the infections were healed after symptomatic treatment. The wounds of the rest 52 patients were healed by first intention without joint infections. The postoperative X-rays demonstrated that 4 hips (5.6%) had loose acetabulum prosthesis, 3 hips (4.2%) had loose femoral prosthesis and 5 hips had loose acetabulum and femoral prosthesis (7.0%), and the total loosening rate was 16.8%. Among which, 8 hips received revision resulting in satisfactory therapeutic effects, and the rest 4 hips had no further treatment. Fifteen hips (21.1%) had heterotopic ossification, which was rel ieved after taking nonsteroidal anti-inflamatory drugs. Harris hip score at final follow-up was (82.7 ± 4.1) points, indicating there was a significant difference between before and after operation (P lt; 0.05). Ten hips were evaluated as excellent, 43 hips good, 14 hips fare, and 4 hips bad, and the excellent and good rate was 74.7%. Conclusion THA through the anterolateral approach is effective for the treatment of patient with hip joint flexion rigidity caused by AS.
Objective To explore the cause of haematoma after the cemented total hip arthroplasty (THA) and find out the way to decrease the incidence of haematoma perioperatively. Methods From March 2000 to October 2006, 103 patientswere treated with the cemented THA. Among the patients, 44 were males and 59 were females with their ages ranging from 36 to 89 years, averaged 55.3 years.The femoral neck fracture (Garden 4) was found in 49 patients, avascular necrosis of the femoral head (Ficat 4) in 26, and osteoarthritis of the hip joint (Tonnis 3) in 28. Their illness course ranged from 1 day to 8 years. The average Harris score preoperatively was 36 (range, 1948). The patients were divided into Group A (n=43) and Group B (n=60). The patients in Group A underwent the conventional surgical operations from March 2000 to December 2003; the patients in Group Bunderwent the same surgical procedures combined with additional procedures (e.g., ligation of the external rotators before incision, use of plastic bandage after the drainage tube was pulled out, prolonged stay period in bed postoperatively) from January 2004 to October 2006. Results In Group A, postoperative haematoma occurred in 9 patients and the averaged 317.8±75.3 ml(range,110-410 ml) of the accumulated blood was drained with a syringe. An average amount for the firstdrainage of the accumulated blood was 86.7±30.7 ml(range, 50-125 ml)， and an average drainage time was 4.2(range, 2-7). In Group B, postoperative haematoma occurred in 2 patients, with an amount of 110 ml and 160 ml of the accumulated blood and an amount of 40 ml and 60 ml of the drained blood at thefirst drainage. There was statistical difference in the amount of heamotoma between two groups(P＜0.05). The followup of 91 patients (39 in Group A, 52 in Group B) for 1.2-5.5 years (average, 3.7 years) revealed that the Harris scores were 78 in Group A and 85 in Group B on average.The Harris score for pain was 44 (Grade A) in 16 patients, 40 (Grade B) in 24 patients, and 30 (Grade C) in 3 patients in Group A; Grade A in 48 patients,Grade B in 12 patients, and Grade C in none of the patients in Group B. There was no statistical difference in Harris score between the two groups (P＞0.05). Conclusion Additional surgical procedures for the cemented THA, such as ligation of the external rotators before incision, use of plastic bandage afterthe drainage tube is pulled out, and prolonged stay in bed postoperatively, can greatly help to reduce the incidence of postoperative haematoma and the amount of the accumulated blood.
The basic stress pathway above the acetabular dome is important for the maintenance of implant stability in acetabular reconstruction of total hip arthroplasty (THA). The purpose of this study was to describe the basic stress pathway to provide evidence for clinical acetabular reconstruction guidance of THA. A subject-specific finite element (FE) model was developed from CT data to generate 3 normal hip models and a convergence study was conducted to determine the number of pelvic trabecular bone material properties using 5 material assignment plans. In addition, in the range of 0 to 20 mm above the acetabular dome, the models were sectioned and the stress pathway was defined as two parts, i.e. 3D trabecular bone stress distribution and quantified cortical bone stress level. The results showed that using 100 materials to define the material property of pelvic trabecular bone could assure both the accuracy and efficiency of the FE model. Under the same body weight condition, the 3D trabecular bone stress distributions above the acetabular dome were consistent, and especially the quantified cortical bone stress levels were all above 20 MPa and showed no statistically significant difference (P>0.05). Therefore, defining the basic stress pathway above the acetabular dome under certain body weight condition contributes to design accurate preoperative plan for acetabular reconstruction, thus helping restore the normal hip biomechanics and preserve the stability of the implants.
Objective To summarize the mid- to long-term effectiveness of total hip arthroplasty (THA) in the treatment of the involved hips in patients with ankylosing spondylitis (AS), and to investigate its influencing factors. Methods Between March 1999 and May 2011, 32 patients (42 hips) with AS and involved hip underwent THA. There were 26 males and 6 females with a mean age of 39 years (range, 20-78 years). The disease duration ranged from 2 to 41 years, with a median of 10 years. Metal-on-polyethylene bearings were used in 19 hips, and ceramic-on-ceramic bearings in 23 hips. The diameter of prosthetic femoral head was 36 mm in 15 hips and was 28 mm in 27 hips; and all the prostheses were fixed biologically. The Harris score, visual analogue scale (VAS) score, and total range of motion (ROM) of the hip were compared between at pre- and post-operation to evaluate the effectiveness. The DeLee zone was used for describing acetabular prosthesis, the Gruen zone for describing femoral prosthesis, and the Brooker criterion for evaluating the heterotopic ossification. Results Healing of incision by first intention was achieved in all patients after operation. There was no complication of anesthetic accident, infection, or neurovascular injury. Twenty-nine cases (39 hips) were followed up 5-17 years (mean, 9 years). Anterior dislocation of hip joint occurred in 2 hips of 24 hips (28 mm diameter), but did not in 15 hips (36 mm diameter). At last follow-up, the Harris score, VAS score, and the total hip ROM were significantly improved (P<0.05). The shorter the disease duration was, the higher postoperative Harris score and the greater postoperative total hip ROM would be (P<0.05); the bigger diameter of prosthetic femoral head was, the greater postoperative total hip ROM would be (P<0.05). All the acetabular components and femoral stems were well fixed at last follow-up. The osteolysis rate around the acetabular cup in the metal-on-polyethylene bearing group (50%, 9/18) was higher than that in the ceramic-on-ceramic bearing group (0, 0/21). No prosthetic loosening was observed in 2 groups. Seven hips were found to have heterotopic ossification, including 5 hips of Brooker grade I and 2 hips of Brooker grade II. Conclusion THA is an effective method to treat involved hips in patients with AS; especially for patients having shorter duration of the disease, THA shows better effectiveness when the bigger diameter of prosthetic femoral head and ceramic-on-ceramic bearing are used.
Objective To compare the early effectiveness between SuperPATH approach and traditional Hardinge approach in total hip arthroplasty (THA). Methods Between May 2015 and March 2016, 154 patients (173 hips) undergoing initial THA were included. THA was performed by SuperPATH approach in 64 cases (70 hips) in group A and by traditional Hardinge approach in 90 cases (103 hips) in group B. There was no significant difference in gender, age, body mass index, type of disease, and Harris hip score (HHS) between 2 groups (P>0.05). The incision length, operation time, intraoperative blood loss, postoperative drainage volume, transfusion rate, ambulation time, length of stay, and complications were recorded. The HHS and visual analogue scale (VAS) were compared between 2 groups before operation and at 1 day, 3 days, 1 week, 3 weeks, 6 weeks, 12 weeks, and 24 weeks after operation. And the relative parameters were measured for imaging evaluation of prosthesis position. In addition, the stratification analysis was performed on 92 patients (100 hips) who received the SuperPATH technology. Results The incision length, ambulation time, and length of stay in group A were significantly less than those in group B (P<0.05); the operation time, transfusion rate, and intraoperative blood loss of group A were significantly higher than those of group B (P<0.05); and there was no significant difference in postoperative drainage volume between 2 groups (t=1.901,P=0.071). The follow-up period was 6 to 15 months (mean, 9 months). The VAS scores at 1 day, 3 days, and 1 week after operation in group A were significantly lower than those in group B (P<0.05), but the HHS scores at 1 day, 3 days, 1 week, and 3 weeks after operation in group A were significantly higher than those in group B (P<0.05). At 24 weeks after operation, the acetabular cup abduction and the proportion within the safe zone showed no significant difference between 2 groups (P>0.05); the anteversion angle and limb length difference in group A were significantly greater than those in group B (P<0.05), and the proportion of anteversion angle within the safe zone and eccentricity and recovery rate were significantly lower than those in group B (P<0.05). In the stratification analysis, the operation time, incision length, intraoperative blood loss, transfusion rate, and VAS score at 1 day after operation in the former 30 hips were significantly higher than those in the latter 70 hips (P<0.05). Great trochantern fracture and dislocation of the hip joint occurred in 1 and 2 of the former 30 hips, but no complications occurred in the latter 70 hips. No injury of nerve or blood vessel, deep vein thrombosis, infection, and prosthetic loosening were observed in the 2 groups. Conclusion Compared with the Hardinge approach, the SuperPATH approach shows the advantages in little trauma, fast recovery, satisfactory effectiveness, and slight early postoperative pain, but it shows the disadvantages of much intraoperative blood loss and long operation time. In addition, SuperPATH approach needs a more anteverted angle, a smaller eccentricity, and a learning curve, so the mid-term and long-term outcomes still need further follow-up study.
Objective To investigate the change of the femoral offset and hip center of rotation (COR) after using Jumbo cups in total hip arthroplasty (THA) revision. Methods The clinical data of 23 patients who underwent THA revision using Jumbo cups between January 2010 and May 2015 were retrospectively analyzed. Morselized bone graft was performed on 8 cases, morselized bone graft combined with structural bone graft on 10 cases. There were 10 males and 13 females, aged 65.4 years on average (range, 51-77 years). The disease duration was 1-24 years (mean, 8.57 years). The reasons for revision included aseptic loosening in 21 cases and periprosthetic infection in 2 cases. The Harris hip score and visual analogue scale (VAS) were 43.04±5.05 and 5.70±0.97 before operation respectively. According to the Paprosky acetabular defect classification, there were 5 cases of type I, 5 cases of type II A, 3 cases of type II B, 6 cases of type II C, and 4 cases of type III A. The X-ray films showed that the femoral offset was (40.65±4.09) mm for normal side and was (44.04±5.08) mm for affected side at preoperation, showing significant difference (t=4.098,P=0.000). Ten patients underwent femoral offset reconstruction (43.48%) but 13 patients did not (56.52%) before operation. The COR was reconstructed in 10 cases (43.48%); COR elevation was observed in 11 cases (47.83%), and COR decline in 2 cases (8.69%) before operation. Results Primary healing of incision was obtained in all patients, with no complication of infection, vascular injury, deep vein thrombosis, dislocation of the joint, or fracture around prosthesis. All the patients were followed up 12-76 months (mean, 22.48 months). The Harris hip score and VAS were 82.09±4.53 and 0.74±0.62 at 1 year after operation respectively, showing significant differences when compared with preoperative scores (t=37.831,P=0.000;t=22.318,P=0.000). The X-ray films showed that the femoral offset was (43.87±3.57) mm for affected side at 1 year after operation, showing no significant difference when compared with preoperative one (t=0.250,P=0.805), but significant difference was found between affected side and normal side (t=5.591,P=0.000). The femoral offset was restored in 16 patients (69.57%) and was not restored in 7 patients (30.43%) after operation. The COR was restored in 15 patients (65.22%) and was not restored in 8 patients (34.78%). Conclusion Using Jumbo cups or combined with morselized or structural bone graft is effective in restoring hip COR and femoral offset at the maximum limit in THA revision, with good short-term outcome and improved stability of acetabular prosthesis.
Objective To study the imaging features of the hip joint by measuring the imaging parameters of spine, pelvis, and hip joint before and after total hip arthroplasty (THA) in patients with ankylosing spondylitis (AS) undergoing THA so as to provide reference for selection of operation methods and prosthesis. Methods Between January and July 2015, 38 patients (56 hips) with AS underwent primary THA as AS group, and 36 patients (45 hips) with osteonecrosis of the femoral head underwent THA as control group. There was no significant difference in side (χ2=1.14,P=0.95). The acetabular abduction angle (ABA), acetabular anteversion angle (AVA), center collum diaphyseal (CCD), offset, height from rotation center to lesser trochanter (HRCLT), femoral intertrochanteric distance (FID) were measured by CT three-dimensional morphology. The canal flare index (CFI), cortical thickness index (CTI), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were measured by X-ray film before operation. The AVA, ABA, and the filling ratio were measured on the postoperative X-ray film. Results There was no significant difference in preoperative AVA and ABA and postoperative ABA between 2 groups (P>0.05), but significant difference was found in postoperative AVA (t=6.71,P=0.00). The mean PI, SS, and PT in AS group were 48.37° (range, 41-58°), 5.64°(range, 2-11°), and 12.85° (range, 5-26°), respectively. There was significant difference in CCD, CFI, and CTI between 2 groups (t=3.63,P=0.04;t=5.12,P=0.02;t=3.91,P=0.04), but offset, HRCLT, and FID all showed no significant difference (t=0.41,P=0.36;t=0.33,P=0.56;t=0.59,P=0.12). On the basis of the Noble classification, medullary cavity of the femur was rated as chimney type, ordinary type, and champagne flute type in 32, 18, and 6 hips of AS group, and in 4, 28, and 13 hips of control group respectively. Filling ratio of distal segment in AS group was significantly lower than that in control group (t=5.64,P=0.02), but there was no significant difference in the filling ratio of middle and proximal segments between 2 groups (t=0.29,P=0.61;t=0.55,P=0.13). Conclusion Compared with patients having osteonecrosis of the femeral head, there is no significant difference in preoperative AVA and ABA, but postoperative AVA significantly increase in patients with AS. Because AS patients have mainly chimney type medullary cavity of the femur, the filling ratio of middle and distal segment is lower when tapered stems are used, and the filling ratio of anatomic stems is higher.
Objective To compare the early effectiveness between by anterior approach via Bikini incision and by OCM approach in the primary total hip arthroplasty (THA). Methods Between June 2015 and March 2016, 60 patients with ischemic necrosis of the femoral head who accorded with the inclusion criteria were chosen in the study, who were divided into 2 groups according to different surgical approaches. THA was performed on 30 patients by anterior approach via Bikini incision (group A), and on 30 patients by OCM approach (group B). There was no significant difference in age, gender, body mass index, side of affected hip, Steinberg stage of ischemic necrosis of femoral head, preoperative hemoglobin, preoperative Harris score, and preoperative visual analogue scale (VAS) between 2 groups (P>0.05). The operation time, length of incision, intraoperative blood loss, transfusion rate, starting time of straight leg raising exercise, starting time of active abduction of hip, hospitalization time, the incidence of limb length discrepancy, postoperative Harris score and VAS score were recorded and compared between 2 groups. Anteroposterior pelvic X-ray films were taken to measure acetabular abduction and acetabular anteversion. Results Primary healing of incision was obtained in all patients of 2 groups, and there was no significant difference in complication between 2 groups (χ2=0.144,P=0.704). All the patients of 2 groups were followed up 3 to 12 months, averaged 6 months. There was no significant difference in operation time, length of incision, intraoperative blood loss, transfusion rate, hospitalization time, and starting time of straight leg raising exercise between 2 groups (P>0.05). Group A was significantly shorter than group B in starting time of active abduction of hip (t=–4.591,P=0.000), and was significantly lower than group B in the incidence of limb length discrepancy (χ2=5.455,P=0.020). After operation, neither Harris score at 2 weeks, 6 weeks, 3 months, and 6 months nor VSA score at 24 hours and 6 weeks showed significant difference between 2 groups (P>0.05). The anteroposterior pelvic X-ray films showed that all the prostheses were in good position, and there was no femoral prosthesis subsidence, acetabular cup displacement or dislocation. No significant difference was found in acetabular abduction and acetabular anteversion at 2 days after operation between 2 groups (t=0.887,P=0.379;t=0.652,P=0.517). Conclusion Both of two approaches in THA can avoid muscle damage and achieve favorable short-term effectiveness. But, anterior approach via Bikini incision is superior to OCM approach in starting time of active abduction of hip and the incidence of limb length discrepancy.