Objective Using the mono-energy reconstruction images and X-ray films to investigate whether the ABG Ⅱ short-stem could improve the filling ratio, stability, and alignment in the Dorr type C femur, compared with the Corail long-stem. MethodsAmong patients who were with Dorr type C femurs and treated with total hip arthroplasty between January 2006 and March 2012, 20 patients with a Corail long-stem (Corail group) and 20 patients with an ABG Ⅱ short-stem (ABG Ⅱ group) were randomly selected. The differences in gender, age, body mass index, and preoperative diagnoses between the two groups were not significant (P>0.05). The ABG Ⅱ group was with a mean follow-up of 142 months (range, 102-156 months), and the Corail group was with a mean follow-up of 107 months (range, 91-127 months). There was no significant difference in the Harris score and subjective satisfaction score between the two groups at last follow-up (P>0.05). At last follow-up, dual-energy CT scans with mono-energy image reconstruction were used to calculate the prosthetic filling ratio and to measure the alignment of the prosthesis in the coronal and sagittal positions. Stability assessment was performed based on X-ray films, and the subsidence distance was measured using EBRA-FCA software. ResultsX-ray film observation showed that the prostheses in the two groups were stable and no signs of loosening was found. The incidence of pedestal sign was significantly lower in the ABGⅡ group than in the Corail group (P<0.05), and the incidence of heterotopic ossification was significantly higher in the ABGⅡ group than in the Corail group (P<0.05). The subsidence distance of femoral stem in ABG Ⅱ group was significantly greater than that in Corail group (P<0.05), and the subsidence speed of femoral stem in ABG Ⅱ group was also greater than that in Corail group, but the difference was not significant (P>0.05). The overall prosthesis filling ratio was significantly higher in the ABG Ⅱ group than in the Corail group (P<0.05), while the coronal filling ratio at the lesser trochanter, 2 cm below the lesser trochanter, and 7 cm below the lesser trochanter were not significant (P>0.05). The results of prosthesis alignment showed that there was no significant difference in the sagittal alignment error value and the incidence of coronal and sagittal alignment error >3° between the two groups (P>0.05), while the coronal alignment error value in the ABG Ⅱ group was significantly greater than that in the Corail group (P<0.05). Conclusion Although the ABG Ⅱ short-stem avoids the distal-proximal mismatch of the Corail long-stem in the Dorr type C femur and thus achieves a higher filling ratio, it does not appear to achieve better alignment or stability.
Abstract The fracture of the prosthetic stem after prosthetic replacement of femoral head is not rare. In this study, the photoeastic instrument was used to study the stress distribution on the prosthetic stem following its insertion and to analyse the factors influencing the fracture of the stem. Through the examination of 9 places in 8 cases, it was found that:(1) The removal of femoral calcar and the inframedullary filling of the bone cement directly influenced the stress distribution. (2) The valgus or varus condition of the prosthesis would lead to stress concentration on the stem. (3) Once lossening of the prosthesis occured it would change the preliminary installingstress distribution in the upper femur which would lead to fatigue fracture. Ths experimental data and clinical observation would provide scientific basis forthe prevention of fracture of prosthetic stem following prosthetic replacement of femoral head.
ObjectiveTo evaluate the clinical value of multi-slice CT in the diagnosis of complications due to breast augmentation. MethodsWe collected the imaging data of 32 female patients who accepted multi-slice CT examination in the second People's Hospital of Chengdu after breast augmentation between February 2010 and February 2015. The position, shape, edge, internal density, leakage, rupture and hard nodules of the prosthesis were observed and analyzed carefully. ResultsIn the 32 patients with breast augmentation, 12 were normal with bilateral symmetry and without abnormal shape or density. Among the other 20 patients, 11 had capsular contracture, 5 had prosthesis leakage, rupture and hard nodules, 4 had breast infection, 1 had fibroadenoma, 1 had cystoma, and 5 had little calcified nodules in the breast tissue. ConclusionThe multi-slice CT scan can clearly and accurately show the position, shape and size of the breast prosthesis as well as the existence of leakage, rupture and hard nodules in the prosthesis. It plays a very important role in the diagnosis of the complications due to breast augmentation and can be effective guidance for clinical operation.
Objective To analyze the causes and the reoperation therapies after salvage limb surgery with prosthesis for bone tumors. Methods The retrospective analysis was performed on 85 patients undergoing the limb salvage operation with prosthetic replacement for tumors from January 1994 to December 2004. Ofthe patients, 21 (13 males and 8 females, aged 18-58 years) underwent reoperations for various reasons. All the diagnoses were pathologically confirmed(10 patients with osteosarcoma, 4 with chondrosarcoma, 5 with giant cell tumor of the bone, 2 with osteofibrosarcoma). The distal femur was involved in 9 patients, proximal tibia in 8, proximal femur in 2, proximal humerus in 1, and acetabulum in 1. According to the Enneking surgical grading system, there were 5 patients in ⅠB and 16 in ⅡB. The time between the first operation and the reoperation was 2 weeks to 20 years. The common reasons for the reoperation were tumor recurrence in 8 patients, prosthetic loosening in 5, no healing of the incision in4,joint dislocation in 3, and implant fracture in 1. The amputation and the prosthesis revision were respectively performed on 6 patients, extensive resection ofthe tumor on 3, the myo-skin flap translocation on 4, internal hemipelvectomy without reconstruction on 1, and open reduction on 1.Results The follow-up in18 patients for 1-5 years (average, 3 years and 4 months) revealed that 4 patients died of osteosarcoma with pulmonary metastasis. The other 14 patients had no tumor recurrence or loosening of the prosthesis, and the incisions healed well. The assessment on the joint function was performed on 13 of the 18 patients and the results were as follows: excellent in 2 patients, good in 5, fair in 4, and poor in 2, with a satisfaction rate of the reoperation with limb salvage of 84.6%and an excellent-good rate of 53.8%. Conclusion Tumor recurrence is the most common reason for the reoperation after the limb salvage with prosthesis for tumors, and loosening of the prosthesis is an important reason, too. By therules of the bone tumor limb savage, the limb salvage operations can also beperformed, which can achieve a satisfactory result of the limb function.
ObjectiveTo evaluate the effect of the surgeon’s handedness on the distribution of prosthesis during primary total knee arthroplasty (TKA).MethodsA retrospective analysis was performed on 86 patients (100 knees) with primary TKA completed by the same right-handed surgeon between December 2016 and December 2018, including 72 cases of single knee and 14 of bilateral knees. The patients were divided into dominant group (right side) and non-dominant group (left side) according to the operating position of the surgeon and each group had 50 knees. There was no significant difference in gender, age, body mass index, disease duration, clinical diagnosis, preoperative Hospital for Special Surgery (HSS) score, and other general data between the two groups (P>0.05). The operation time and complications were recorded in both groups. The function of knee was evaluated by HSS score. Hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle (mMPTA) were measured by using X-ray film of full-length lower extremity before TKA and at 2 weeks after TKA that were used to evaluate the coronal position of the prosthesis. Posterior distal femoral angle (PDFA) and posterior proximal tibial angle (PPTA) were measured by using lateral X-ray films at 3 months after operation that were used to evaluate the sagittal position of the prosthesis.ResultsThere was no significant difference in operation time between the two groups (t=−1.128, P=0.262). One case of posterior tibial artery thrombosis occurred in the dominant group, and 1 case of poor healing of the incision occurred in each of the dominant group and the non-dominant group. Patients in both groups were followed up 12-34 months with an average of 22.0 months. The HSS scores at last follow-up were 87.2±4.3 in the dominant group and 86.8±5.0 in the non-dominant group. There was no significant difference between the two groups (t=0.471, P=0.639). No complications such as periprosthetic infection, prosthetic loosening, or periprosthetic fracture occurred during follow-up. There was no significant difference in the HKA, mLDFA, and mMPTA between the two groups before and after operation (P>0.05). The differences in the incidence of sagittal femoral prosthesis malposition and PDFA between the two groups were significant (P<0.05); however, there was no significant difference in the PPTA, the rate of femoral prosthesis distributed in the neutral position, the incidence of over-flexed femoral prosthesis, and the incidence of anterior femoral notch (P>0.05).ConclusionThe surgeon’s handedness is one of the factors affecting the placement of the sagittal femoral prosthesis in primary TKA. The incidence of sagittal femoral prosthesis malposition could increase when the surgeon performs on the non-dominant side.
ObjectiveTo explore the feasibility of establishment of a artificial joint aseptic loosening mouse model by cobalt-chromium particles stimulation.MethodsTwenty-four 8-week-old male severe combined immunodeficient (SCID) mice were divided into experimental group (n=12) and control group (n=12). The titanium nail was inserted into the tibial medullary cavity of mouse in the two groups to simulate artificial joint prosthesis replacement. And the cobalt-chromium particles were injected into the tibial medullary cavity of mouse in experimental group. The survival of the mouse was observed after operation; the position of the titanium nail and the bone mineral density of proximal femur were observed by X-ray film, CT, and Micro-CT bone scanning; and the degree of dissolution of the bone tissue around the tibia was detected by biomechanical test and histological staining.ResultsTwo mice in experimental group died, and the rest of the mice survived until the experiment was completed. Postoperative imaging examination showed that there was no obvious displacement of titanium nails in control group, and there were new callus around the titanium nails. In experimental group, there was obvious osteolysis around the titanium nails. The bone mineral density of the proximal tibia was 91.25%±0.67%, and the maximum shear force at the tibial nail-bone interface was (5.93±0.85) N in experimental group, which were significantly lower than those in control group [102.07%±1.87% and (16.76±3.09) N] (t=5.462, P=0.041; t=3.760, P=0.046). Histological observation showed that a large number of inflammatory cells could be seen around the titanium nails in experimental group, while there was no inflammatory cells, and obvious bone tissue formation was observed in control group.ConclusionThe artificial joint aseptic loosening mouse model can be successfully established by cobalt-chromium particles stimulation.
Objective To summarize the clinical outcome of the Ribbed anatomic cementless total hip arthroplasty (THA) in the treatment of hip-joint disease. Methods From January 2001 to June 2005, 34 patients(38 hips) with hip-joint disease were treated with Ribbed anatomic cementless THA. Their ages ranged from 29 to 55 years with an average age of 42.7 years.The disease course was from 3 to 18 years. Among these cases, there were 7 cases (7 hips) of femoral neck fracture, 5 cases(5 hips) of traumatic arthritis after fracture of acetabulum, 15 cases(16 hips) of necrosis of the femoral head and 7 cases(10 hips) of ankylosing spondylitis. Four patients were operated on both hip joints. The average Harris hip score was 38.6(25-57) before operation. Results Twenty-one patients(23 hips) were followed up 861 months with an average of 35 months. The Harris hip score was 76-98 after operation with an average of 92.3, showing significant difference when compared with that before operation(Plt;0.05). The excellent and good result was achieved in 93.5 % of patients. Radiographs showed no prosthetic osteolysis and no evidence of loosening. Pain in the thigh occurred in 4 patients,and it can be relieved by using nonsteroid antiinflammatory drug. Conclusion Ribbed anatomic cementless THA has good clinical and radiographic results in treating patients with hip-joint disease.
Objective To analyze the outcomes and complications after total knee replacement(TKR) with posterior stabilized prosthesis(PS) and to investigate the influencing factors relating to outcomes. Methods From January 1998 to August2004, 60 cases (74 knees) of osteoarthritis underwent TKR with PS. The outcomeswere evaluated according to the HSS(hospital for special surgery) scoring. The difference in outcomes between patients with post-operative complications and without complications were compared. Pearson correlation was used to analyze post-operative outcomes and the pre-operative factors relating to patients. Results All 74 knees werefollowed up 42.5months(24 to 94 months). The scores for HSS, pain, function, ROM muscle strength, flexion deformity and stability of knees after operation were 84.2±14.2, 25.7±6.9, 17.9±4.3,13.1±2.0，9.2±0.8，8.1±0.4 and 9.3±0.1 respectively. They were improved to some extents, especially pain alleviation was remarkable. The excellent and good rate for outcome assessment was 90.5%. Among 74 knees, 10 cases suffered from postoperative complications, including 1 case of common peroneal nerve paralysis, two cases of wound faulty union, one case of wound infection, one case of joint infection, one case of stiff knee, two cases of deep vein thrombosis and 2 cases of patellofemoral joint complications. The excellent and good rate of outcome in patients with complications(60%) was much lower than that in patients without complication(95.3％),and there was significant difference betweenthem (P＜0.05). Analysis for correlation showed that postoperative HSS score was positively correlative with the postoperative HSS score, pain and function score of knees. The correlation value was 0.523，0.431 and 0.418 respectively(Plt;0.01). Whereas, postoperative HSS score was not correlative with ROM, muscle strength, flexion deformity, stability of knee, age, weight andbody mass index(P＞0.05). Conclusion TKR with PS is an effective method for severe osteoarthritis. The outcomes after TKR have a positive correlation with the HSS score, pain and function score of knees before surgery. Complicationsassociating with surgery have a negative influence on outcomes.
Objective To improve the accuracy of the acetabular component placement using the nonimage based surgical navigation system. Methods Twenty-three patients (14 males, 9 females; age, 28-55 years;26 hips）with hip disease underwent the total hip arthroplasty (THA) using the nonimage based surgicalnavigation system from February 2004 to April 2006. Rheumatoid arthritis was found in 3 patients (3 hips), necrosis of the femoral head in 6 patients (6 hips), and osteoarthritis in 14 patients (16 hips). All the patients were randomly divided into the following 2 groups: the navigated group (11 patients, 13 hips), treated by THA using the nonimage based surgical navigation system; and the control group (12 patients, 13 hips), treated by the traditional THA. According to thedesign of the study, the acetabular component was placed in the best inclination angle (45°) and the anteversion angle (15°). The postoperative component position was examined. Results No fracture, dislocation, infection or injury to the sciatic nerve was found. In the navigated group, the inclination and the anteversion reached 15.4±1.4° and 45.5±1.3°, respectively. In the control group,the inclination and the anteversion were 13.9±7.6° and 43.7±6.4°, respectively. The inclination difference was considered statistically significant (Plt;0.01). All the patients were followed up for 10-40 months,averaged 26 months. In the navigated group, the postoperative average Harris hip score was 95 (range,85-110), with an excellent result in 11 hips and a good result in 2 hips. In the control group, the postoperative average Harris hip score was 92 (range,75-110), with an excellent result in 9 hips, a good result in 3 hips, and a fair result in 1 hip. The Harris hip score difference was considered statistically significant (Plt;0.05). There was a significantly better result obtained in the navigated group than in the control group. Conclusion The acetabular component can be implanted accurately by the nonimage based surgical navigation system, which can reduce the incidence of the loosening of the prostheses and has an important value in clinical practice.