Objective To investigate the changes of low back pain (LBP) and spinal sagittal parameters in patients with unilateral Crowe type Ⅳ developmental dysplasia of the hip (DDH) after total hip arthroplasty (THA). Methods The clinical data of 30 patients who met the selection criteria between October 2018 and March 2020 were retrospectively analyzed. Patients were divided into LBP group (16 cases) and control group (14 cases) according to whether there was LBP before operation. There was no significant difference between the two groups of patients in gender, age, body mass index, affected sides, preoperative Harris score (P>0.05). Full-length lateral X-ray films of the spine were taken within 1 week before operation and at 1 year after operation, and the following imaging indicators were measured: sacral slope (SS), lumbar lordosis (LL ), spinal tilt (ST), spine-sacral angle (SSA), sagittal vertebral axis (SVA). The visual analogue scale (VAS) score, lumbar Oswestry disability index (ODI), the Harris score of the hip joint before operation and at 1 year after operation, and the occurrence of postoperative complications were collected and analysed. Results In the LBP group, LBP was relieved to varying degrees at 1 year after operation, of which 13 patients (81.3%) had complete LBP remission; VAS score decreased from 4.9±2.3 preoperatively to 0.3±0.8, ODI decreased from 33.5±22.6 preoperatively to 1.3±2.9, the differences were all significant (t=7.372, P=0.000; t=5.499, P=0.000). There was no new chronic LBP in the control group during follow-up. The Harris scores of the two groups significantly improved when compared with those before operation (P<0.05); there was no significant difference between the two groups at 1 year after operation (t=0.421, P=0.677). There was no significant difference in imaging indexes between the two groups before operation and the difference between pre- and post-operation (P>0.05). At 1 year after operation, ST and SVA in the LBP group, SSA in the control group, and SS in the two groups significantly improved when compared with those before operation (P<0.05); there was no significant difference in the other indexes between the two groups before and after operation (P>0.05). Conclusion Unilateral Crowe type Ⅳ DDH patients with LBP before operation were all relieved of LBP after THA. The relief of LBP may be related to the improvement of spinal balance, but not to lumbar lordosis and its changes.
Objective To evaluate the early effectiveness and summarize the initial application experiences of Mako robot-assisted total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) in adults. Methods Between August 2018 and January 2020, 55 cases of DDH (75 hips) were treated with Mako robot-assisted THA. There were 10 males and 45 females with an average age of 51 years (range, 30-73 years). There were 35 cases of unilateral hip and 20 cases of bilateral hips. The DDH was classified as Crowe type Ⅰin 29 hips, type Ⅱ in 20 hips, type Ⅲ in 6 hips, and type Ⅳ in 20 hips. The modified Harris score was 54.8±16.0, the hip joint range of motion was 90° (80°, 100°), and the leg length discrepancy (LLD) was 22.0 (10.5, 47.0) mm. The preoperative surgical plan was made in the robot system based on the CT data. The reaming and installation of the acetabular cup were completed with the assistance of the robot system. The distance between the rotation center of the hip joint and the teardrop (horizontal distance, vertical distance), inclination angle, and anteversion angle were measured on the pelvic X-ray film to evaluate the position of the acetabular prosthesis. The above indicators were compared with preoperative planning to evaluate the accuracy of robotic-assisted surgery. The modified Harris score, the range of motion, and the LLD were used to evaluate the early effectiveness. Results The 75 hips of THAs were completed with the assistance of Mako robots. There was no significant difference in the acetabular inclination angle, the horizontal distance and the vertical distance of the rotation center between the preoperative planning and the postoperative measurement values (P>0.05); the acetabular anteversion angle was significantly smaller than the postoperative measurement value (t=–2.482, P=0.015). Four hips located beyond the Lewinnek safety zone, and 71 hips located within the Lewinnek safety zone. All patients followed up 6-24 months (mean, 13 months). All incisions healed by first intention. At last follow-up, the modified Harris score was 85.5±11.2, the hip joint range of motion was 120° (110°, 120°), and the LLD was 3.8 (2.0, 8.1) mm; all improved significantly compared with preoperative ones (P<0.05). Except for one nerve injury case, there was no other complication. Conclusion Mako robot-assisted THA is a safe and effective method for adult DDH, which can optimize the acetabular cup positioning, hip function, and leg length, but the long-term effectiveness needs to be confirmed by further studies.
ObjectiveTo compare the effectiveness of three different fixation methods after subtrochanteric shortening osteotomy (SSO) in total hip arthroplasty (THA) for Crowe type Ⅳ developmental dysplasia of the hip (DDH). Methods A clinical data of 63 patients (78 hips) with Crowe type Ⅳ DDH, who underwent THA with SSO between November 2014 and May 2019, was retrospectively analyzed. Among them, 18 patients (20 hips) obtained stability by intramedullary pressure provided by the S-ROM modular prostheses (group A); 22 patients (30 hips) underwent prophylactic binding by stainless steel wire after osteotomy and before stem implantation (group B); 23 patients (28 hips) were fixed with autogenous cortical strut grafts and stainless steel wire or cables (group C). There was no significant difference in gender, age, body mass index, affected limb side, and preoperative Harris score between groups (P>0.05). The operation time, complications, imaging results, hip functional score of the three groups were recorded and compared. Results There was no significant difference in the operation time between groups (P>0.05). All incisions healed by first intention. All patients were followed up, and the follow-up time was 2.5-4.0 years (mean, 3.1 years) in group A, 1.5-5.5 years (mean, 3.2 years) in group B, and 1.0-5.0 years (mean, 1.6 years) in group C. There was no significant difference in Harris score or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between groups at 4 and 12 months after operation (P>0.05). X-ray films showed that there was no significant difference in osteotomy healing rate at 4, 8, and 12 months after operation and the osteotomy healing time between groups (P>0.05). There was no complications such as joint dislocation, prosthesis loosening, prosthetic joint infection, or heterotopic ossification during follow-up, except for the distal femoral fracture of 1 hip during operation in group B. Conclusion In THA for patients with Crowe type Ⅳ DDH, the stainless steel wire binding alone and autogenous cortical strut grafts combined with stainless steel wire or cable binding can not significantly promote the osteotomy healing compared with femoral prosthesis intramedullary compression fixation. For patients with nonmatched medullary cavity after SSO, it is recommended to apply autogenous cortical strut grafts with wire or cables for additional fixation.