ObjectiveTo evaluate the accuracy of using smartphone to measure the angle of acetabular component in total hip arthroplasty (THA). MethodsBetween June 2012 and September 2015, the acetabular abduction and anteversion angles were measured in 50 patients undergoing THA. There were 24 males and 26 females, aged 37 to 83 years (mean, 71 years). The left hip was involved in 22 cases and the right hip in 28 cases. Of 50 patients, 34 suffered from fracture of the femoral neck, and 16 suffered from avascular necrosis of the femoral head. Acetabular dysplasia was excluded in all cases. A smartphone was used to measure the acetabular abduction and anteversion angles during operation; standard Picture Archiving and Communication Systems (PACS) was used to measured the acetabular abduction and anteversion angles on the X-ray film at 1 week after operation. It was defined as positive that the component angle values by PACS measurement were greater than those by the smartphone measurement, whereas as negative. The two measurement methods were compared, and intra-observer variability was assessed by analyzing the intraclass correlation coefficient (ICC), the Mann-Whitney U-test was used to analyze difference. ResultsThe ICC was 0.84 in the acetabular component angles by smartphone and PACS measurement methods. The acetabular component abduction angle was (44.02±1.33)° and the anteversion angle was (17.62±2.20)° by smartphone measurement. The acetabular component abduction angle was (44.74±4.05)° and the anteversion angle was (17.22±5.57)° by PACS measurement. There was no significant difference between two measurement methods (Z=-1.977, P=0.482; Z=-0.368, P=0.713). The acetabular component angle was in the safe zone in 44 cases; and the acetabular component anteversion angle was beyond safe range of 1 to 5°, and the abduction angle was beyond safe range of 1 to 3° in 6 cases. Intra-measurement variability was -21 to +10° for the anteversion angle and -10 to + 9° for the abduction angle, indicating that the acetabular component anteversion angle by smartphone measurement was greater than that by the PACS measurement, and the abduction angle was less than that by PACS measurement. ConclusionSmartphone is a convenient tool to measure the acetabular component angle in THA.
Objective To analyze the impact of robot assistance on the restoration of limb length and offset distance in total hip arthroplasty (THA). Methods A retrospective analysis was conducted on the clinical data of 316 patients who underwent unilateral primary THA between September 2019 and August 2023. Among them, 117 patients underwent robot-assisted THA (group A), and 199 patients underwent conventional THA (group B). There was no significant difference between the two groups in the gender, age, or side of the hip replacement (P>0.05); but there was a significant difference in the preoperative diagnosis (P<0.05). The leg length discrepancy (LLD) and global offset (GO) dfference were measured on preoperative anteroposterior pelvic X-ray films, and absolute values were used for comparison between groups. Results The operations in both groups were successfully completed. Postoperative imaging measurements showed that the LLD and GO dfference in group A were significantly lower than those in group B (P<0.05). Among them, group A had 32 cases (27.4%), 5 cases (4.3%), and 0 case (0) of LLD>3 mm, >5 mm, and >10 mm, respectively, while group B had 115 cases (57.8%), 75 cases (37.7%), and 22 cases (11.1%), respectively; and the differences in above indicators between groups were significant (P<0.05). Group A had 40 cases (34.2%), 3 cases (2.6%), and 0 case (0) of GO dfference>5 mm, >10 mm, and >20 mm, respectively; group B had 103 cases (51.8%), 54 cases (27.1%), and 7 cases (3.5%), respectively. There was no significant difference in the proportion of patients with GO>20 mm between groups (P>0.05), while there were significant differences in other indicators between groups (P<0.05). Conclusion Compared with traditional THA, robot assisted THA has more advantages in restoration of limb length and offset distance.
Objective To analyze the occurrence of osteolysis in total hip arthroplasty (THA) with highly cross-linked polyethylene prosthesis during a follow-up of more than 15 years. Methods The clinical data of 84 patients (105 hips) treated with THA in the Affiliated Hospital of Kanazawa Medical University in Japan between June 2000 and April 2004 and met the selection criteria was retrospectively analyzed. There were 7 males and 77 females, aged from 41 to 75 years, with an average of 56.4 years. There were 94 hips with secondary hip osteoarthritis, 4 hips after pelvic osteotomy, 2 hips with primary hip osteoarthritis, 2 hips with traumatic hip osteoarthritis, 2 hips with osteonecrosis of the femoral head, and 1 hip with rheumatoid arthritis. According to Crowe classification, there were 79 hips of type Ⅰ, 19 hips of type Ⅱ, 6 hips of type Ⅲ, and 1 hip of type Ⅳ. The highly cross-linked polyethylene acetabular liner combined with a 26 mm zirconia femoral head were used in all patients. X-ray films were taken after operation to analyze the radiation transmission and osteolysis around the acetabular prosthesis. The vertical distance (the distance between the teardrop line at the lower edge of the pelvis and the perpendicular line of the hip rotation center), the horizontal distance (the horizontal distance between the hip rotation center and the interteardrop line and the vertical line at the lower edge of the teardrop), and the acetabular cup anteversion angle were measured at last follow-up. The acetabular and femoral osteolysis was analyzed by CT scan and three-dimensional multiplanar reconstruction (3D-MPR). Combined with X-ray film and CT results, osteolysis was evaluated according to the Narkbunnam score. Results Deep vein thrombosis of lower limbs occurred in 2 cases. All patients were followed up 15-18 years, with an average of 15.9 years. One hip dislocation and 1 periprosthetic fracture occurred postoperatively, and no acetabular loosening or prosthetic lining ruptures occurred. Except for 1 patient who had a radiolucent line in the acetabulum after operation, the other 83 patients did not show any radiolucent line in the acetabulum or the femur. None of the patients underwent hip revision. X-ray films at last follow-up showed an acetabular cup anteversion angle of −10°-39°, with an average of 22°; a vertical distance of 3.5-47.1 mm, with an average of 24.6 mm; and a horizontal distance of 22.6-48.1 mm, with an average of 31.7 mm. There was no acetabular or femoral osteolysis in all patients on X-ray films and CT 3D-MPR images at last follow-up, and the Narkbunnam score was 0 in any region. Conclusion Highly cross-linked polyethylene prosthesis does not increase the risk of long-term complications such as osteolysis after THA.
ObjectiveTo investigate the effects of the femoral head size on the linear wear rate of highly crosslinked polyethylene (HXLPE) l iner in total hip arthroplasty (THA). MethodsA retrospective analysis was performed on the cl inical data of 41 patients (43 hi ps) who underwent primary THA with HXLPE liner and different sizes of femoral heads between January 2004 and December 2007 for hip diseases. There were 22 males (23 hi ps) and 19 females (20 hi ps) with a mean age of 60.2 years (range, 35-89 years), including femoral neck fracture (26 hi ps), avascular necrosis of femoral head (8 hi ps), osteoarthritis (5 hi ps), rheumatoid arthritis (2 hi ps), and congenital hip dysplasia (2 hi ps). According to the size of the femoral head, the patients were divided into 2 groups: standard head size (26 and 28 mm) was used in 25 cases (26 hi ps, group A) and big head size (32, 36, and 40 mm) in 16 cases (17 hi ps, group B). The cumulative penetration of the femoral head, linear wear rate, and effectiveness were evaluated and compared between 2 groups. ResultsAll the incisions healed by first intention, no complications of infection, deep vein thrombosis, or nerve injury occurred. The patients were followed up 5-9 years (mean, 5.7 years). No two-stage revision was needed. Harris score was significantly improved at 3 months, 6 months, and 1, 2, 3, 4, and 5 years after operation when compared with preoperative score in each group (P < 0.05), but no significant difference was found between different time points after operation in 2 groups (P > 0.05), and between 2 groups at each time point (P > 0.05). Acetabular abduction angle was (31.4±3.8)° in group A and (32.3±4.1)° in group B, showing no significant difference (t=0.482, P=0.621). At last follow-up, no radiographic or cl inical loosening was observed in each group. At 5 years after operation, X-ray results of acetabular components showed radiolucent line ( < 1 mm) in 1 case (1 hi p) and 1 case (1 hi p) of 2 groups respectively; but X-ray results of femoral components showed no radiolucent line. There was no significant difference in the cumulative penetration of the femoral head between 2 groups at 1, 2, 3, 4, and 5 years after operation (P > 0.05). The linear wear rate was (0.026±0.007) mm/year in group A and (0.025±0.007) mm/year in group B, showing no significant difference between 2 groups (t=0.708, P=0.483). ConclusionNo association is found between femoral head size and the linear wear rate of HXLPE liner. It is an ideal interface of THA because of its low linear wear rate.
目的 观察强直性脊柱炎髋关节受累强直时行全髋关节置换术的临床疗效。 方法 对2003年1月-2008年1月45例(78髋)强直性脊柱炎患者行全髋关节置换术，其中38例(55髋)进行了平均4.5年（2~7年）的随访。 结果 38例患者术后髋关节功能均明显改善，Harris评分由术前（16.3±1.7）分提高到术后（83.4±4.6）分。髋关节屈曲畸形矫正，55个髋关节总活动度(屈伸、内收、外展、内旋、外旋等6个方向活动总和)由术前（38.7±7.6）°增加至术后（191.2±10.3）°。术后髋关节疼痛消失，膝关节痛、腰骶部疼痛明显改善，步态较术前改善，生活自理。 结论 短期随访全髋关节置换术治疗强直性脊柱炎髋关节受累强直安全、有效。
Objective To explore the effect of minimally invasive and mini-incision surgery (MIS) in total hip arthroplasty (THA) on late osteonecrosis of femoral head (ONFH). Methods From March 2003, Eighteen patients (22 hips) with ONFH underwent MIS in THA. Their ages ranged from 24to 57 years, including 13 males and 5 females. The mean body mass index ranged from 17.1 to 30.1(24.6 on average). The Harris hip score was 46 points before operation. Modified posterior-lateral approach was adopted, and the MIS THA was performed by cementless prosthesis. As a comparison, 18 patients (22 hips) were performed by conventional THA at the same period. The data, including bleeding volume during operation, incision length, operative time, and postoperative function recovery, were compared. Results Follow-ups were done for 6 to 20 months (11 months on average). Dislocation occurred in one patient that underwent conventional THA 2 days after operation. No complication occurred in MIS THA group. The incision lengths ranged from 8.7 to 10.5 cm (9.3 cm on average) in MIS THA group, being statistically different (Plt;0.01). There was no significant difference in Harris scoring of the function between the two groups both before the operation and after the operation (Pgt;0.05). The operative time was almost the same, but the bleeding volume in MIS THA group was less (Plt;0.05). The function recovery was faster in MIS THA group.Conclusion The MIS THA is an alternative to the treatment of late ONFH. The advantages of MIS THA are fewer trauma, less bleeding volume, and faster recovery. The MIS THA should be performed by surgeons with rich experiences in THA and hospitals with necessary instruments.
ObjectiveTo retrospectively compare the mid-term effectiveness between by direct anterior approach (DAA) and by posterolateral approach in total hip arthroplasty (THA).MethodsBetween January 2009 and December 2010, 110 patients (110 hips) treated with THA and followed up more than 5 years were chosen in the study. THA was performed on 55 patients by DAA (DAA group), and on 55 patients by posterolateral approach (PL group). There was no significant difference in gender, age, body mass index, types of hip joint disease, and preoperative Harris score between 2 groups (P>0.05). The operation time, amount of bleeding, length of hospital stay, postoperative complications, and the Harris scores were recorded and compared.ResultsThere was no significant difference in operation time and length of hospital stay between 2 groups (t=0.145, P=0.876; t=1.305, P=0.093). The amount of bleeding was significantly less in DAA group than in PL group (t=2.314, P=0.032). All patients were followed up 5-7 years (mean, 5.97 years). Complications happened in 5 cases (9.1%) of DAA group and in 3 cases (5.5%) of PL group, and there was no significant difference in the incidence of complications between 2 groups (χ2=0.539, P=0.463). There was significant difference in Harris scores at 6 months after operation between 2 groups (t=2.296, P=0.014), but no significant difference was found in Harris score at 1 year and 5 years between 2 groups (t=1.375, P=0.130; t=0.905, P=0.087). Further analysis, at 6 months after operation, the joint function score in DAA group was significantly higher than that in PL group (t=1.087, P=0.034), while there was no significant difference in the pain score and range of motion score between 2 groups (t=1.872, P=0.760; t=1.059, P=0.091).ConclusionTHA by DAA has the advantages of less bleeding and faster recovery. The short-term effectiveness is superior to the THA by traditional posterolateral approach, but there is no obvious advantage in the mid-term effectiveness.
ObjectiveTo investigate the clinical and radiographic results of total hip arthroplasty (THA) for the treatment of hip arthrosis in patients with ankylosing spondylitis (AS). MethodsA retrospective analysis was made on the clinical data from 131 patients (195 hips) who underwent THA for AS between September 2001 and August 2011 with a follow-up period of more than 2 years. There were 100 males (152 hips) and 31 females (43 hips), aged 17-69 years (mean, 33.7 years). The average interval between AS onset and THA was 13.7 years (range, 1-50 years). The left hips were involved in 30 cases, the right hips in 37 cases, and bilateral hips in 64 cases. Preoperative Harris hip score was 18.0±13.7; the sum passive range of motion was (36.2±51.2)°; and the hip passive-flexion arc was (23.4±32.6)°. In 175 hips with passive flexion of less than 90°, 134 hips had flexion contracture. Based on preoperative X-ray films and CT scan, 195 hips were divided into the non-ankylosed subgroup (86 hips), fibrous ankylosed subgroup (43 hips), and bony ankylosed subgroup (66 hips); and the recovery of hip function was compared between subgroups after operation. ResultsIntraoperative complications included linear fractures of femoral calcar in 4 hips, fractures of acetabular posterior column in 1 hip, femoral shaft fractures in 2 hips, and iatrogenic sciatic nerve injury in 3 hips; postoperative complications included anterior dislocation in 2 hips. The average follow-up period was 51.3 months (range, 24-143 months). Bone healing was observed at 3-6 months after operation (mean, 3.9 months). At last follow-up, the average Harris hip score increased to 86.4±14.1, the sum passive range of motion increased to (202.0±28.0)°, and the hip passive-flexion arc increased to (93.2±15.3)°, all showing significant differences when compared with preoperative ones (P<0.05). Based on a four-class scale for subjective satisfaction, the patients were very satisfied, satisfied, and not satisfied with the results of THA in 100, 80, and 15 hips respectively. X-ray films showed radiolucent line (<2 mm) in 5 acetabular components (zones I and II); heterotopic ossification was observed in 49 hips after THA. There was no significant difference in the Harris hip score among 3 subgroups after THA at last follow-up (P>0.05). At last follow-up, the degree of passive flexion in the fibrous ankylosed subgroup and bony ankylosed subgroup was significantly lower than that in the non-ankylosed subgroup (P<0.05), and the sum passive range of motion in the fibrous ankylosed subgroup was significantly lower than that in the non-ankylosed subgroup (P<0.05), but no significant difference was found in the other variables among the 3 sub groups (P>0.05). ConclusionFor severe hip arthrosis in patients with AS, the overall outcomes after THA are ideal with a good midterm prosthetic survivorship, a low complication rate, and a high satisfaction of patients. However the hip function after THA is still less satisfactory.
Objective To compare heterotopic ossification between femoral head reconstruction and total hip arthroplasty(THA) in patients with ischemic necrosis of femoral head(INFH). Methods Between June 1994 and December 2004, the femoral heads were repaired in 1 005 patients with INFH,the total hip was replaced in 485 patients with INFH. The rate of heterotopic ossification was observed in 74 (Ficat Ⅲ to Ⅳ stages) of 1 005 patients and 80 of 485 patients given THA to compared the results of the two methods. Results These patients were followed up 2 to 10 years(6.5 years on average). The rates of heterotopic ossification were 5.4%(4/74) and 22.5%(18/80), respectively. There was statistically significant difference between two operative methods (Plt;0.01). Conclusion The rate of heterotopic ossification of femoral head reconstruction is lower than that of THA, so femoral head reconstruction is a better operative method for young patients and THA is suitable for old patients.