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 study the clinical feasibility of the prosthetic composites of the intercalary allograft and the segmental allograft in reconstruction of the skeletal defect after the limb tumor resection. Methods Between August 1999 and December 2003, 28 patients with skeletal defects after the limb tumor resection were treated with the intercalary allograft or the segmental allograft megaprosthesis composite for reconstruction of skeletal defects. The bone involvements were observed in 16 patients with osteosarcoma, 4 patients with parosteal osteosarcoma, 5 patients with Ewing sarcoma, and 3 patients with soft tissuesarcoma. Preoperative biopsy was performed on all the patients, and the pathological result was confirmed after surgery. According to the Enneking system, 5 patients were grouped in ⅠB and 23 patients in ⅡB. The patients with osteosarcomaor Ewing sarcoma received the standard chemotherapy before and after operation.Eighteen and ten patients received the segmental allograft prosthetic compositereplacement and the intercalary allograft with the interlocking intramedullary nail fixation, respectively. The functional outcome was evaluated by the MSTS score. Results According to the follow-up for 5-48 months (average, 24 months), local recurrence was observed in 1 patient who underwent amputation eventually. Of the 28 patients, 3 developed nonunion of the allografthost junction accompanied by severe resorption and 2 developed deep infection. No allograft fracture was seen in the patients. Most of the patients achieved a good functional result with an average MSTS score of 23.4. ConclusionThe prosthetic composite replacement of the intercalary allograft and the segamental allograft can be used n the skeletal defect reconstruction after the limb tumor resection. The stablecontact in the allografthost junction and the b intramedullary internal fixation can help to reduce the complication rate of the allograft.
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.
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.
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.
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.
Abstract:Since 1978 the definition of prosthesis-patient mismatch（PPM） was first introduced by Rahimtoola, it has attracted the attention of foreign researchers. The PPM phenomenon is concerned to be an important factor which will affect patients＇ survival rate and quality of life. Till now, a lot of effort should still be put on this problem. But unfortunately, this problem is still being neglected in our country. This paper is a review of PPM from it＇s many aspects, such as definition, current research status, prevention, and it＇s research prospect. We hope this paper will intensify the clinicians＇ knowledge on PPM.
Objective To summarize the application of double valve ring enlargement combined with mitral Chimney technique (Chimney Commando) in the secondary valve replacement and to analyze the efficacy in the near and medium term. Methods Patients who underwent the secondary aortic valve and mitral valve (double valve) replacement by Chimney Commando in Wuhan Asia Heart Hospital from 2019 to 2022 were included, and their clinical data were retrospectively collected to analyze the safety and feasibility of this procedure in secondary valve replacement of small aortic root patients. Results A total of 49 patients (44 females and 5 males) were included. The body surface area was 1.64±0.17 m2. The time from the first operation was 13.10±5.90 years. Except for 4 patients whose first operation was valvuloplasty, the remaining 45 patients were all patients after valve replacement, 41 patients of double valves replacement, including 39 patients with mechanical valve and 2 patients with biological valve. The majority of the aortic valves were St.Jude regent 19 mm or St.Jude regent 21 mm, accounting for 30.61% and 34.69%, respectively. The mitral valves were predominantly St.Jude 25 mm mechanical valves, making up 65.31%. All patients underwent Chimney Commando double valve ring enlargement, and the mean time of aortic occlusion was 154.00±45.40 min. The mean size of the aortic valve was 23.90±1.40 mm and that of the mitral valve was 28.20±1.20 mm, and the transvalvular pressure difference across the aortic valve was 20.16±5.76 mm Hg at 6 months postoperatively. There was one death during hospitalization due to multi-organ failure. The follow-up time ranged from 1 to 24 months with a median time of 8 months. Two patients were implanted with permanent pacemakers during the follow-up period and 1 patient died due to massive stroke and malignant arrhythmia. Conclusion Chimney Commando is safe and effective in patients with secondary double valve replacement, and the postoperative prosthetic valves have good hemodynamics, and can achieve good clinical results in the near and medium term.
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.
【Abstract】 Objective To investigate the early effectiveness of the Discover cervical artificial disc replacement in treating cervical spondylosis. Methods Qualified for the selective standard, 24 patients with cervical spondylosis were treated between March 2010 and March 2011. Of 24 patients, 13 patients underwent anterior cervical decompression and fusion (ACDF) (ACDF group, between March 2010 and September 2010) and 11 patients underwent Discover cervical artificial disc replacement (CADR group, between September 2010 and March 2011). There was no significant difference in gender, age, disease duration, lesions typing, and affected segments between 2 groups (P gt; 0.05). The operative time, blood loss, and complications were recorded. Japanese Orthopaedic Association (JOA) scores, Neck Disability Index (NDI) scores, and Odom’s scores were used to evaluate the postoperative effectiveness. In CADR group, the cervical range of motion (ROM) in all directions, and prosthesis eccentricity were measured before and after operation. Results Symptoms disappeared and no complication occurred after operation in the patients of 2 groups. The patients were followed up 12 to 18 months (mean, 15.3 months) in ACDF group and 6 to 12 months (mean, 9.6 months) in CADR group. The NDI scores in CADR group were significantly higher than those in ACDF group at 1, 3, and 6 months (P lt; 0.05), but no significant difference was observed in JOA score improvement rate between 2 groups (P gt; 0.05). According to Odom’s score at last follow-up, the results were excellent in 6 cases, good in 4 cases, and fair in 3 cases with an excellent and good rate of 76.92% in ACDF group, and were excellent in 9 cases, good in 1 case, and poor in 1 case with an excellent and good rate of 90.91% in CADR group, showing no significant difference (χ2=3.000, P=0.223). The patients in CADR group had significant limit of cervical joint ROM in flexion and extension and right bending at 1 month (P lt; 0.05), but cervical joint ROM restored after 3 months. The ROMs of left bending at 3 months and 6 months were bigger than preoperative value (P lt; 0.05). Meanwhile, ROM in left bending were bigger than that in right bending in replaced segment and upper segment (P lt; 0.05), and the ROM difference between left bending and right bending in upper segment was 2 times higher than that in the replaced segment; a marked linear correlation (P lt; 0.05) existed between the ROM difference and prosthesis eccentricity, and prosthesis bias had bigger ROM in lateral bending. Conclusion Discover cervical artificial disc replacement for treatment of cervical spondylosis can provide a good effectiveness and cervical postoperative movement function. As a new prosthesis, it has some merits such as simple operative steps and less complications.
