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.
Objective To discuss the recent advancement of total knee arthroplasty (TKA) in the aspects of prosthesis selection, and compare the cl inical effect of every kind of knee prostheses so as to provide more information for cl inical appl ication. Methods The l iterature concerning prosthesis selection was extensively reviewed, and the methods and data were analyzed and summarized. Results The major disputes consisted of posterior cruciate retained versus excised,fixed-bearing versus mobile-bearing, high-flex versus standard implants and patella resurfacing versus nonresurfacing for TKA. Every kind of knee prostheses displayed safety and effectiveness in early and medium term follow-up, no significant differences were found in cl inical results. Conclusion Prosthesis selection in TKA should be overall considerated, and the merits of every kind of prostheses should be judged with long-term follow-up results.
OBJECTIVE There are various methods used to treat the Kienbock’s disease with various outcomes. This study investigated the effect of combining acrylic lunate prosthesis replacement with resection of articular branches to wrist from anterior and dorsal interosseous nerve. METHODS From January 1992 to January 1997, six cases were included. All of the patients were in stage III according to Lichtman’s classification. Besides replacement of the acrylic lunate prosthesis, segment of the pure sensory branches from anterior and posterior interosseous nerves were resected. RESULTS Follow-up for 10 to 54 months (an average of 32 months) the pain was relieved in all patients except one. The range of movement of wrists were as followings: The extension of the wrist was 20 to 35 degrees (an average of 26 degrees) and flexion was 20 to 35 degrees (an average of 32 degrees). There was no improvement in radial and ulnar deviation. CONCLUSION Lunate prosthesis replacement combined with resection of articular branches to wrist resulted in a painless wrist and was a satisfactory method.
Objective To summarize and analyze the operation-correlated compl ications of total knee arthroplasty (TKA)with posterior stabil ized prosthesis (PS). Methods From October 2000 to October 2007, 707 cases (816 knees) underwent TKA. All the TKA knees were divided equally into former and latter groups according to the operation time (408 knees for each group). In the former group (October 2000 to January 2005, n=350), there were 63 males (84 knees) and 287 females (324 knees), aging (63.5 ± 7.8) years. A total of 198 left knees affected and 210 right knees affected; 292 single kneesaffected and 58 both knees affected. There were 304 knees of osteoarthritis, 84 knees of rheumatoid arthritis and 20 knees of other disease. The disease course was (9.3 ± 5.6) years. The knee range of motion (ROM) was (97.2 ± 8.7)°, the HSS score was 47.4 ± 12.2. In the latter group (January 2005 to October 2007, n=357), there were 77 males (92 knees) and 280 females (316 knees), aging (62.7 ± 6.3) years. A total of 221 left knees affected and 187 right knees affected; 306 single knees affected and 51 both knees affected. There were 278 knees of osteoarthritis, 109 knees of rheumatoid arthritis and 21 knees of other disease. The disease course was (8.6 ± 5.1) years. The knee ROM was (101.1 ± 10.3)°, the HSS score was 49.3 ± 11.2. We modified the method of lateral patellar retinaculum release and used a new femoral rotational al ignment technique in the latter group. The intraoperative and postoperative compl ications were divided into mild, moderate and severe. The HSS score, ROM and compl ications of the knee were compared and analyzed statistically during the follow-up. Results The former group was followed up 5.3 years (1 to7 years), compl ications occurred in 278 knees (68.1%), including mild in 136 knees (33.3%), moderate in 135 knees (33.1%) and severe in 7 knees (1.7%). The latter group was followed up 2.1 years (0.5 to 3.5 years), compl ications occurred in 159 knees (39.0%), including mild in 111 knees (27.2%), moderate in 47 knees (11.5%) and severe in 1 knee (0.2%), and there was significant difference between them (P lt; 0.001). There was significant difference in increased ROM between the former group (6.0 ± 3.7)° and the latter group (14.4 ± 4.2)° after operation (P lt; 0.05). There was significant difference in increased HSS score between the former group (36.9 ± 3.7)and the latter group (44.0 ± 4.2) after operation (P lt; 0.05). Conclusion The TKA is a complex operation with innumerable potential compl ications. To accumulate operative experience and improve surgical skills are the key points to reduce the operation-correlated compl ications.
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.
In unicompartmental replacement surgery, there are a wide variety of commercially available unicompartmental prostheses, and the consistency of the contact surface between the common liner and the femoral prosthesis could impact the stress distribution in the knee after replacement in different ways. Medial tibial plateau fracture and liner dislocation are two common forms of failure after unicompartmental replacement. One of the reasons is the mismatch in the mounting position of the unicompartmental prosthesis in the knee joint, which may lead to failure. Therefore, this paper focuses on the influence of the shape of the contact surface between the liner and the femoral prosthesis and the mounting position of the unicompartmental prosthesis on the stress distribution in the knee joint after replacement. Firstly, a finite element model of the normal human knee joint was established, and the validity of the model was verified by both stress and displacement. Secondly, two different shapes of padded knee prosthesis models (type A and type B) were developed to simulate and analyze the stress distribution in the knee joint under single-leg stance with five internal or external rotation mounting positions of the two pads. The results showed that under a 1 kN axial load, the peak contact pressure of the liner, the peak ACL equivalent force, and the peak contact pressure of the lateral meniscus were smaller for type A than for type B. The liner displacement, peak contact pressure of the liner, peak tibial equivalent force, and peak ACL equivalent force were the smallest for type A at 3° of internal rotation in all five internal or external rotation mounting positions. For unicompartmental replacement, it is recommended that the choice of type A or type B liner for prosthetic internal rotation up to 6° should be combined with other factors of the patient for comprehensive analysis. In conclusion, the results of this paper may reduce the risk of liner dislocation and medial tibial plateau fracture after unicompartmental replacement, providing a biomechanical reference for unicompartmental prosthesis design.
ObjectiveTo investigate the accuracy and value of digital planning with bone parameters in determining the appropriate prosthesis for total hip arthroplasty (THA). MethodsThe preoperative radiographs was taken in 13 cases scheduled for THA between September 2012 and June 2013; the bone parameters were measured by digital template, and the prosthesis was selected and preoperative plan was made. There were 4 males and 9 females with an average age of 54.08 years (range, 41-79 years), including 8 left hips and 5 right hips. The causes were osteonecrosis of the femoral head in 8 cases and femoral neck fracture in 5 cases (3 cases had osteonecrosis of the femoral head). ResultsThe operation time was 140-254 minutes (mean, 191.8 minutes). Two cases received blood transfusion, and 6 patients received plasma substitutes transfusion. There was no intraoperative fractures or postoperative thrombosis; atherosclerotic plaque occurred in 2 cases. Thirteen cases were followed up 12-24 months with an average of 17.3 months. The pain was relieved and limb function was improved in all patients. Harris score was significantly improved from preoperative 54.0±12.9 to 91.1±4.1 at 3 months after operation (t=7.259, P=0.000). Compared with the actual implants, the appropriate sizes of femoral stem was selected in 12 cases (92.31%) (excellent in 9 cases, good in 3 cases, and poor in 1 case), and the appropriate sizes of acetabular cup was selected in 11 cases (84.62%) (excellent in 7 cases, good in 4 cases, and poor in 2 cases). ConclusionDigital planning could increase the accuracy in choosing the size of prosthesis for THA.
OBJECTIVE To review the history and current status of total wrist arthroplasty. METHODS The original articles about wrist arthroplasty in recent years were reviewed. RESULTS The properties of wrist prosthesis of different generations were reviewed, with the emphasis on the prosthesis design and biomechanical behaviours. The surgical techniques, complications and salvage procedures were also discussed. CONCLUSION Although wrist arthrodesis is highly successful in treating the end-stage wrist arthritis, total wrist arthroplasty using well-designed prosthesis remains an alternative for the patients with special demands of hand functions.
Objective To evaluate the clinical effect of Easy Prosthesis D-10 on open preperitoneal groin tension-free hernioplasty. Methods The operative time, operation-correlated complications, hospital stay and recent follow-up findings of 63 patients underwent preperitoneal groin tension-free hernioplasty were analyzed from October 2006 to April 2008. Results No case died in perioperative period. The average operative time was (47.6±10.5) minutes. None of incision infection and scrotal hydrocele occurred. The average hospital stay was (7.7±2.1) days. During follow-up period of 6 to 24 months, no recurrence, chronic pain and foreign body sensation were found. Conclusion The open preperioneal groin tension-free hernioplasty by Easy Prosthesis D-10 is safe and reliable, especially for the inguinal hernia with large hernia ring or defect of transversalis fascia and recurrent hernia.
ObjectiveTo discuss the influence of early postoperative hemodynamic, postoperative mortality and the incidence of adverse cardiovascular events with the phenomenon of prosthesis-patient mismatch. MethodsWe retrospectively analyzed the clinical data of 89 patients who had simple aortic valve replacement in our hospital bewteen January 2012 and January 2014. The 89 patients were divided into two groups including a match group (16 females and 48 males with average age of 58.1±10.4 years) and a mismatch group (15 females and 10 males with average age of 65.3±12.8 years). We compared early results between the two groups. ResultsThere is a statistic difference (P < 0.05) in aortic flow velocity, mean pressure gradient, and the maximum pressure gradient between the two groups. The survival rate of the match group is significantly lower than that of the mismatch group (P < 0.05). And there is a statistical difference in adverse cardiovascular event-free incidence between the two groups (P < 0.001). ConclusionThe phenomenon of prosthesis-patient mismatch can affect postoperative hemodynamic and lead to heart failure after surgery. And early mortality and the incidence of cardiovascular adverse events in patients are increased due to prosthesis-patient mismatch.