[Application of bone-retaining femoral stem prosthesis in young patients with Dorr C femoral medullary cavity].

OBJECTIVE: To assess the clinical efficacy of Tri-Lock bio-short prosthesis in artificial total hip arthroplasty(THA) in young patients with Dorr type C femoral medullary cavity. METHODS: From January 2010 to January 2014, 35 young patients(37 hips) with in the chimney-like femoral medullary cavity received Tri-Lock BPS prosthesis of THA, including 18 males(20 hips) and 17 females with an average age of (32.2±3.0) years old ranging from 21.2 to 38.5 years old. There were 16 cases of rheumatoid hip arthritis (17 hips), 8 cases of rheumatoid arthritis (9 hips), and 11 cases of aseptic necrosis of femoral head (11 hips). All cases were complicated with different degrees of osteoporosis. According to Singh index, 26 cases were classified as Grade III and 9 cases as Grade II. Biological prostheses were used for the acetabulum, with ceramic lining and full ceramic femoral head. The proximal femoral medullary cavity was Dorr type C on anteroposterior X-ray. After replacement, X-ray examination was performed to locate the prosthesis stem. Engh and Harris criteria were used to evaluate the stability of bone-prosthesis interface and hip function, respectively. Changes of hip movement pre-operation and at last follow-up were compared. RESULTS: All patients were followed up for 18 to 45 months(means 33.8 months). Harris hip scores in 35 cases (37 hips) increased significantly from preoperative 61.8±3.0 (51.2 to 73.5) to 93.3±6.5 (92.5 to 98.8) points at last follow-up (t=54.745, P<0.01). The hip mobility increased from (46.5±8.0)°(0° to 55°) before surgery to(101.2±10.5)°(85° to 130°) at the last follow-up, the difference was statistically significant(t=133.091, P<0.01). Immediately after surgery, the prostheses were tightly packed with the medullary cavity. At the final follow-up, 17 hips had significant femur cortical bone thickening;12 hips had varying degrees of stress occlusal bone resorption at proximal femoral, including 9 degree I(low femur density, round and blunt) and 3 degree II(involving small rotor) hips. Meanwhile, 15 hips had significant femur cortical bone thickening without thigh pain. CONCLUSIONS: The cone-shaped short Tri-lock biological short-stem can fill Dorr C chimney-like medullary cavity and effectively retain good proximal femoral bone mass. Titanium microporous coating on the surface can effectively increase the friction of the prosthesis. The short-stem end in the medullary cavity can effectively avoid the occurrence of coxa varus.

[Application of Tri-Lock bone preservation stem in acetabular protrusion combined with shorten defect of femoral head and neck].

OBJECTIVE: To evaluate the manipulation technique and clinical outcome of Tri-Lock bone preservation stem for acetabular protrusion combined with shorten defect of femoral head and neck. METHODS: From January 2013 to December 2015, 10 patients(12 hips) with acetabular protrusion combined with shorten defect of femoral head and neck were treated with total hip arthroplasty(THA) including 5 males and 5 female with an average age of(51.6±3.0) years old ranging from 42.5 to 67.5 years old. The acetabular prostheses were all biological prosthesis with the ceramic lining, the whole ceramic femoral head was used in all the cases. The posterior-lateral hip incision was adopted in the surgery. The follow-up was carried out in 12 months after the surgery, and later once a year. The Harris score system in growth of femoral side described was used to assess the joint function of the patients before and after the surgery. RESULTS: Ten patients were followed up for 8 to 48 months with an average of 33.0±3.5. All the incisions healed well and there were no complications such as femoral fracture, infection, dislocation and neurovascular injuries. The biological compression of the acetabulum and the stem of the femur was realized immediately after operation in 10 patients(12 hips). X-ray at 3 months after the operation showed bone growth were extended in a wide range, which could achieve bone fixation, no loosening and re-invagination. The range of hip movement increased from (45.8±7.5)° to (90.0±6.5)° at the final follow-up, with flexion increased to (89.0±6.0)°, abduction increased to (35.5±7.3)° and internal rotation increased to(31.8±6.6)°, the outer rotation increased to(32.6±5.2)°. The mean Harris scores had improved from 45.7±7.5 pre-operatively to 93.5±8.0 post-operatively, there was statistically significant difference between before and after surgery (t=144.832, P<0.05). CONCLUSIONS: Combined with acetabular treatment, Tri-Lock bone retention of the femoral stem in the treatment of femoral head and neck with shortening of the acetabular retraction and severe hip joint soft tissue contracture in patients, could be well pressed and retained more bone. The reconstruction of the acetabulum and the delamination of soft tissue are required during the operation. The results were safe and satisfactory in the middle and short term follow-up.

[Perioperative and drug management of patients with rheumatoid arthritis treated with joint replacement].

Rheumatoid arthritis (RA) is a most common inflammatory joint disease with direct invasion of joint synovial membrane, cartilage and bone. Currently, although the RA mitigation drugs are being improved continously, but these drugs only can delay the development of joint dysfunction. Total hip arthroplasty or total knee arthroplasty(THA or TKA) has become the only choices for patients with advanced RA, and the joint function and deformity of the patients after surgical treatment can be improved to some extent. However, the progression of RA has a direct effect on the long-term clinical effect of the surgery, and how to improve perioperative management, and combine the joint replacement surgery and drug therapy effectively, have become the focus of attention in clinical doctors. This article intends to summarize the current situation of domestic and foreign management of usage of pre-operative drugs, operation skills, prosthesis selection, postoperative treatment, rehabilitation and complications, so as to improve the long-term efficacy of joint replacement.