Total Hip Arthroplasty (THA) is an effective treatment to reconstruct a normal, pain-free hip joint for patients. However, factors such as scar tissue, obstruction of internal fixation and potential infection of 2 operations make the operation more difficult. 13 cases of traumatic arthritis of the hip joint were admitted to our hospital from March 2005 to May 2009, all of which were treated with THA and achieved satisfactory results, which are summarized as follows.
1.Clinical data
There were 13 cases in this group, 3 males and 10 females. Age 39-58 years old, average 49.8 years old. Traffic accident injury 8 cases, fall injury 2 cases, smash injury 3 cases. According to Judet-Letoumel1 fracture classification, there were 7 cases of posterior wall fracture, 3 cases of posterior wall plus posterior column fracture, 1 case of anterior column fracture, and 2 cases of posterior column fracture.
Four of them were combined with femoral head dislocation and three were combined with femoral head fracture. All 13 cases in this group underwent incisional reduction, and the clinical manifestations after surgery (1 year and 2 months to 5 years and 1 month, mean 4.2 years) were different degrees of joint pain, limitation of movement, and walking claudication.
The preoperative Harris score of THA was 24-68, with an average score of 48.6. X-ray examination revealed narrowing or loss of hip joint space, formation of periacetabular bone redundancy, irregular shape of acetabulum and femoral head, and increased density in some areas. Among them, 2 cases showed heterotopic ossification around the hip joint, 2 cases had defects in the acetabulum, 3 cases had collapsed femoral head necrosis and subluxation of the femoral head.
2.Treatment method
All 13 cases in this group took a posterior lateral incision of the hip joint, excised the posterior acetabular scar, heterotopic ossified tissue and joint capsule, fully exposed the acetabulum and femoral head, relaxed the surrounding soft tissues, and carefully protected the sciatic nerve from being stretched and compressed. The screws were not removed in 3 of the 13 cases, and the plates were partially removed in 2 cases, but the prostheses were not imaged (Figure 1-A). 2 patients with bone defects in the acetabulum had their femoral heads trimmed and implanted to maximize the reconstruction of the normal biomechanical structure of the acetabulum. In 13 cases, the acetabulum and proximal femur were in good bone condition, and biologic prostheses were selected for implantation. Postoperatively, the patients had continuous negative pressure drainage for 24-48 h, anti-infection treatment for 5-7 d, and routine use of blood-activating drugs for 5-7 d to prevent deep vein thrombosis. On the first day after surgery, the patient could sit up in bed and perform passive knee extension, hip flexion and abduction activities to exercise the function of quadriceps and abductor muscles, and on the third day after surgery, the patient could support the double crutches and walk without weight.
3. Treatment results
There was no infection, revision, or deep vein thrombosis of the lower limb in 1 case after surgery, and no dislocation of the artificial joint, and all wounds healed in one phase. At the follow-up of 9-41 months (mean 29 months), all patients obtained significant improvement in hip function, pain relief, and correction of lower limb shortening, with Harris score of 84-95, mean 88.7. No periprosthetic osteolysis or loosening was found on regular x-ray examination (Figure 1-B), and the patients’ quality of life was significantly improved compared with that before surgery, and they were able to take care of themselves and perform non-manual work.
Figure 1 X-ray of total hip arthroplasty for traumatic hip osteoarthritis
A. The internal fixation was partially removed, the prosthesis was properly placed, and the hip joint correspondence was good;
B, 1 year after the operation, the pulp and joint correspondence was good, and the prosthesis was not loose.
4. Discussion
4.l The indications for surgery and preoperative preparation for THA are: hip pain, restricted movement, femoral head necrosis and collapse, femoral head dislocation or subluxation, and misplacement of the internal fixation into the joint space; meanwhile, the patient is an elderly patient or a non-heavy laborer. Careful consideration should be given to young, obese and heavy laborers. The presence of active systemic or local infection, poor general condition of the body and the presence of serious comorbidities of the heart and lungs and other important organs should be considered as contraindications to surgery. latent infection present in 2 operations, as well as complications such as vascular and nerve injury and prosthesis dislocation, pose a higher risk to the operation. Preoperative examinations should be improved to understand the patient’s general condition and potential infection factors, and to ensure that all examination indexes are normal before surgery is performed. Preoperative pelvic radiographs should be taken, and if necessary, oblique and closed-hole oblique radiographs of the affected iliac bone should be taken to understand the anatomy and bone quality of the acetabulum in detail; frontal and lateral radiographs of the middle and upper femur should also be taken to understand the bone quality of the femur, and if necessary, CT examinations should be performed to understand the condition of the hip joint from a three-dimensional perspective and to further clarify the extent of acetabular defect and the blockage of internal fixation. Preoperatively, according to the image performance, make a preliminary choice of the type and model of the prosthesis; and make a preliminary judgment on the possible influence of internal fixation on the operation, and fully consider the possible unexpected situation during the operation.
4.2 Selection of surgical approach The selection of surgical approach should be considered according to the patient’s condition. The access of the last surgery, whether the internal fixation needs to be removed, whether the nerve needs to be released, heterotopic ossification, and acetabular deficiency all affect the choice of surgical access. If the degree of deformity healing of the acetabular fracture is very mild, the surgical approach can be routinely selected according to the operator’s custom; if there are complications such as bone discontinuity, bone defect, severe deformity healing of the fracture, and heterotopic ossification, various modified incisions need to be adopted according to the situation. All 13 cases in our group used the posterior lateral incision. We believe that this approach is quick, time-saving, and can better expose the acetabulum, facilitate the removal of internal fixation, resection of bone fragments and reconstruction of the posterior wall of the defect with bone graft, and facilitate the osteotomy of the femoral neck. Soft tissue tension around the hip joint plays an important role in preventing dislocation after THA, therefore, unnecessary intraoperative soft tissue release is not recommended and complete severance of the gluteus medius muscle is strictly prohibited. No dislocation occurred in this group.
4.3 Treatment of internal fixation There are advantages and disadvantages of removing the internal fixation or not. The internal fixation can be worn, corroded, chemically reactive and cause complications such as sciatica if left in the body. If in contact with the prosthesis, it can cause instability and even loosening. If the internal fixation is completely removed, it is inevitable to expand the operation, prolong the operation time, increase the amount of bleeding, and even cause complications such as sciatic nerve injury.
We believe that the removal of the internal fixation depends on whether the internal fixation affects the implantation of the prosthesis, the exposure of the internal fixation during surgery, and whether the internal fixation is loose or not. In this group of 13 cases, 3 screws were not removed and 2 plates were partially removed due to the difficulty of exposure, but the implantation of the prosthesis was not affected. When taking the posterior column internal fixation, attention should be paid to protect the sciatic nerve. Placing the affected limb in the flexed knee and extended hip position can relax the sciatic nerve and reduce injury. If the tip of the screw is exposed in the acetabulum and difficult to remove, or may cause re-fracture after removal, the tip of the screw can be ground and shortened to cover the cancellous bone particles to avoid direct contact between the internal fixation and the acetabular prosthesis.
4.4 The treatment of acetabular defects is strongly evaluated according to the classification system for clinical application of acetabular bone defects developed by the hip committee of the American Academy of Orthopaedic Surgeons (AAOS), and acetabular defects in traumatic arthritis of the hip joint are mostly intracavitary defects (type II) and segmental defects (type I).
For intracavitary type defects, when the bone defect is 25 mm and structural value bone is required, we usually trim the amputated femoral head and embed it into the bone defect, with the residual gap for granular bone grafting. For segmental bone defects, if the bone defect involves only a very small portion of the acetabular rim, it hardly affects the stability of the prosthesis and can often be ignored. Small bone defects in the anterior acetabular wall rarely affect the stability of the prosthesis and can be left untreated. If the defect of the acetabular roof or the anterior or posterior wall of the medullary socket is large and affects the stability of the acetabulum, structural bone grafting must be carried out to rebuild the stability of the acetabulum, and the amputated femoral head can be trimmed and implanted and fixed by screws or plates.
4.5 Summary Traumatic arthritis of the hip joint is a common complication of late acetabular fracture, which seriously affects the quality of life of patients. THA can reconstruct a normal, painless hip joint for patients.
However, due to the scar tissue, heterotopic ossification, and obstruction of the internal fixation, it increases the difficulty of surgery. The selection of the surgical approach, the treatment of the internal fixation, and the reconstruction of the acetabular defect are issues that must be fully considered by the surgeon. Strict mastery of the surgical indications, adequate preoperative planning and fine intraoperative operation are the keys to the success of surgery. In our group of 13 cases, the postoperative follow-up showed that the Harris score improved significantly compared with the preoperative one and the quality of life improved significantly compared with the preoperative one. However, due to the small number of cases and short follow-up time, the long-term efficacy remains to be further observed.