Objective To design a new custom-made artificial semi-knee joint based on rapid prototyping(RP) technique and to explore a method to solve necroses of allocartilage in hemi-joint allotransplantation. Methods Based on the extracted 3D contour image of the articular cartilage of femoral condyle, the custom-made artificial semi-knee joint was designed with Surfacer 9.0 image processingsoftware. The artificial semi-knee joint design used the femoral condylar 3D contour of the patient as the outer face and the subchondral bone 3D contour of allograft bone as inner face. One dado for medullary nailand two for special designing cages which were used to fix the cartilage into the allograft were added on the inner face. After being converted into RP data format, the computerassisted design was imported into the LPS600 rapid prototyping machine, and the prototype was achieved. Furthermore, the prototype could be modified by hand according to the design. Then the RP model was used as a positive mould to build up a silica gel negativemould, and the negative mould was sent to the factory to manufacture Ti-6Al-4V alloy articular cartilage through ordinary mould-melted founding process. Finally, the whole metal cartilage was completed after melting two special cages on it andpolishing it. Results A new custom-made artificial semi-knee joint was made ad used to treat a 14-year old patient. The custom-made artificial semi-knee joint and the subchondral bone were a perfect match. The operative result was satisfactory. The patient could walk 5 weeks after operation. The bone healing of the auto-bone and allo-bone was achieved 6 months later. A follow-up period lasting 1 yearshowed that the knee joint played a good function. Conclusion The artificial semi-knee joint is a good match for the allograft boneand a good idea to solve necroses of allocartilage in hemijoint allotransplantation.
Objective To systematically review the rehabilitation effect of isokinetic muscle training on knee muscle strength, functional walking ability and dynamic balance in post-stroke patients. Methods PubMed, Ovid Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang databases were searched online for randomized controlled trials on isokinetic muscle training of lower limbs in post-stroke patients. The retrieval time was from inception to October, 2022. Endnote X9 software was used to manage the literature. Cochrane Manual 5.1.0 was used for quality assessment, and RevMan 5.4 software was used for meta-analysis. Results A total of 20 randomized controlled trials were included in the study, with the intervention group using isokinetic muscle training of the lower extremities or combined with conventional rehabilitation training and the control group using conventional rehabilitation training and/or other intervention, with a total of 1448 study subjects. Meta-analysis results showed that the differences in knee flexion peak torque [mean difference (MD)=5.85 N·m, 95% confidence interval (CI) (4.84, 6.85) N·m, P<0.00001], knee extension peak torque [MD=9.09 N·m, 95%CI (4.83, 13.36) N·m, P<0.0001], Time Up Go test [MD=–4.70 s, 95%CI (–6.68, –2.72) s, P<0.00001], 10-meter walking test [MD=–4.71 s, 95%CI (–9.12, –0.31) s, P=0.04], Fugl-Meyer Lower Extremity Motor Function Assessment score [MD=6.61, 95%CI (3.52, 9.70), P<0.0001], and Berg Balance Scale score [MD=5.61, 95%CI (0.91, 10.31), P=0.02] were statistically significant. Conclusion Isokinetic training may improve knee strength and functional walking ability in post-stroke patients, but there is still no strong evidence of improvement in motor function and balance.
【Abstract】 Objective To explore the flexibil ity and rel iabil ity of cementless total knee arthroplasty (TKA) without patellareplacement through a retrospective study of the mid-term therapeutic effect of the treatment of the patients. Methods FromJune 1997 to March 2000, a consecutive series of 152 (152 knees) cementless TKA performed in Hessing-Stiftung was studied. Among them, there were 63 males and 89 females, with 70 left knees and 82 right knees. Their ages ranged from 51 years to 72 years, with an average of 59 years. There were 146 cases of osteoarthritis and 6 cases of traumatic arthritis. The course of the disease lasted for 1.0 years to 3.5 years. The EFK prostheses of German Plus company were used in all the cases. The HSS score before the operation was 41.5 ± 12.3, and the average range of motion was 55º (ranging from 30º to 90º). Results Five patients underwent anterior knee pain, and the pain was released after the appropriate treatment. No deep infection happened in all cases. A total of 145 patients (145 knees) were followed up for 5 years to 8 years. The HSS score was 87.5 ± 8.2 at the end of the follow-up, showing significant difference (P lt; 0.05). The average range of motion was 95º (ranging from 90º to 110º). Partial radiolucencies occurred at the tibia side in 18knees 3 to 6 months after the operation. Among them, the width was less than 2 mm in 15 knees without symptom, and more than 2 mm in 3 knees. There were 2 of the 3 knees which were revised at the tibia side because of the aseptic loosing, while 1 patient had only mild pain in the knee during the follow-up, with no sign of loosing. Conclusion The mid-term effect of cementless TKA is satisfactory. The ingrowth of femur and tibial bones is rel iable. The early stage migration of the component is the main reason of loosing. Satisfying outcomes can also be achieved without patella replacement during TKA.
Objective To investigate the effectiveness of the deep inferior epigastric perforator (DIEP) flap for extreme defects around the knee. Methods Between June 2017 and December 2018, 15 patients with the extreme defects around the knee were admitted. There were 9 males and 6 females with a median age of 36 years (range, 23-51 years). The etiology was the traffic accident in 7 cases, tumor in 5 cases, and burn in 3 cases. The injured location was left knee in 8 cases and right knee in 7 cases. The size of soft tissue defects ranged from 15 cm×10 cm to 30 cm×20 cm, and all defects complicated with exposure of blood vessels, nerves, tendons, and other tissues. Transverse DIEP flaps with 1-2 vascular pedicles were prepared according to the size of the defect, including 6 cases of single-pedicle flaps and 9 cases of double-pedicle conjoined flaps. According to the depth of the defect, 10 cases of skin flaps were thinned under microscope. The size of the DIEP flaps ranged from 16 cm×10 cm to 32 cm×20 cm; the average thickness was 1.5 cm (range, 0.8-1.8 cm); the average pedicle length was 7.5 cm (range, 5.0-9.0 cm). The donor site was directly sutured. Results One single-pedicle flap developed distal necrosis after operation, and healed after skin grafting; the other skin flaps survived, and the wounds at the donor and recipient sites healed by first intention. All patients were followed up 16-28 months (mean, 24 months). The shape and texture of the flap were satisfactory, and there was no abnormal hair growth or obvious pigmentation. There was only linear scar at the donor site and no complication such as abdominal hernia. The appearance and function of the knee were satisfactory. No recurred tumor was observed, and the scar contracture was released. At last follow-up, 13 cases were excellent and 2 cases were good, according to the Knee Society Score (KSS) criteria. Conclusion The DIEP flap is an ideal alternative for repairing the extreme defects around knee, with a concealed donor site, easy dissection, flexible design, as well as less complication.
Objective To review the advance in the researchand clinical application of the tibial rotational alignment technique in the total knee arthroplasty in China and abroad. Methods The recent literature concerned with the tibial rotational alignment technique in the totalknee arthroplasty was extensively reviewed and briefly summarized. Results According to the literature reviewed, the traditional tibial rotational references for the total knee arthroplasty were affected by many factors, so that the references were not accurate enough. There have been no unified references.ConclusionChoosing the range from the medial border of the tibial tubercle to the medial 1/3 of the tibial tubercle, decided by the degrees of the varus deformities and the valgus deformities, to determine the rotaional alignment of the tibial component will create an optimal tibiofemoral rotational alignment.
The clinical performance and failure issues are significantly influenced by prosthetic malposition in unicompartmental knee arthroplasty (UKA). Uncertainty exists about the impact of the prosthetic joint line height in UKA on tibial insert wear. In this study, we combined the UKA musculoskeletal multibody dynamics model, finite element model and wear model to investigate the effects of seven joint line height cases of fixed UKA implant on postoperative insert contact mechanics, cumulative sliding distance, linear wear depth and volumetric wear. As the elevation of the joint line height in UKA, the medial contact force and the joint anterior-posterior translation during swing phase were increased, and further the maximum von Mises stress, contact stress, linear wear depth, cumulative sliding distance, and the volumetric wear also were increased. Furthermore, the wear area of the insert gradually shifted from the middle region to the rear. Compared to 0 mm joint line height, the maximum linear wear depth and volumetric wear were decreased by 7.9% and 6.8% at –2 mm joint line height, and by 23.7% and 20.6% at –6 mm joint line height, the maximum linear wear depth and volumetric wear increased by 10.7% and 5.9% at +2 mm joint line height, and by 24.1% and 35.7% at +6 mm joint line height, respectively. UKA prosthetic joint line installation errors can significantly affect the wear life of the polyethylene inserted articular surfaces. Therefore, it is conservatively recommended that clinicians limit intraoperative UKA joint line height errors to –2−+2 mm.
Objective To explore the technique of the soft tissue balancing inthe total knee arthroplasty (TKA) for the patients with the knees of varus deformity and flexion contracture. Methods From January 2001 to December 2005, 86 patients (19 males, 67 females; age, 57-78 years;average, 66 years) with the knees of varus deformity and flexion contracture underwent primary TKA and the balancing of the soft tissues. All the patients had suffered from osteoarthritis. The unibilateral affection was found in 68 patients and the bilateral affection in 18. The varus deformity angle was averaged 12.3° (range, 6-34°). The soft tissue varus accounted for 56.7% and the bony varus accounted for 43.3%. The flexion contracture lt; 10° was found in 21 knees, 10-19° in 45 knees, 20-29° in 22 knees, and gt;30° in 16 knees, with an average angle of 18.9°. Results The flexion contractures were improved. Before operation the average angle ofthe flexion contracture was 18.9° but after operation only 4 patients had a residual flexion contracture of 5° and the remaining patients had a complete correction. The follow-up for 37 months (range, 6-72 months) in all the patients revealed that only 6 patients had a residual flexion contracture of 5-10° and the others had a full extension. Before operation the average varus angle was 12.3°(range, 6-34°) and the average tibiofemoral angle was 174.7° (range, 70.3-175.6°), but after operation the residual varus angle gt; 3° was only found in 2 patients. The complications occurring during operation and after operation were found in 6 patients, injuries to the attachment of the medial collateral ligaments in 2, patellar clunk syndromes in 2, cerebral embolism in 1, and lacunar infarction in 1, with no nerve disorders left after the medical treatment. No skin necrosis, the cut edge infection or deep infection occurred. Conclusion The balancing of the soft tissues is a major management for correction of the varus deformity and the flexion contracture. The proper balancing of the softtissues can achieve an obvious recovery of the function and correction of the varus deformity after TKA.
ObjectiveTo summarize the prevention and treatment of iatrogenic medial collateral ligament (MCL) injuries in total knee arthroplasty (TKA).MethodsThe relevant literature about iatrogenic MCL injuries in TKA was summarized, and the symptoms, causes, preventions, and treatments were analyzed.ResultsPreventions on the iatrogenic MCL injuries in TKA is significantly promoted. With the occurrence of MCL injuries, the femoral avulsion can be fixed with the screw and washer or the suture anchors; the tibial avulsion can be treated with the suture anchors fixation, bone staples fixation, or conservative treatment; the mid-substance laceration can be repaired directly; the autologous quadriceps tendon, semitendinosus tendon, or artificial ligament can be used for the patients with poor tissue conditions or obvious residual gap between the ligament ends; the use of implant with greater constraint can be the last alternative method.ConclusionNo consensus has been reached to the management of iatrogenic MCL injuries in TKA. Different solutions and strategies can be integrated and adopted flexibly by surgeons according to the specific situation.
Objective To investigate the effect of Navio robot-assisted unicompartmental knee arthroplasty (UKA) on the biomechanics of knee joint during sitting-up movement, and to determine whether UKA can maintain the biomechanical characteristics of knee joint. Methods The clinical data of 8 patients with medial compartment osteoarthritis treated with medial fixed platform of Navio robot-assisted UKA between January 2018 and January 2019 and had the complete follow-up data were retrospectively analyzed. There were 4 males and 4 females; the age ranged from 58 to 67 years, with an average of 62.3 years. The disease duration was 6-18 months, with an average of 13 months. The varus deformity ranged from 4° to 6°, with an average of 5°; the knee flexion range of motion was 0°-130°, with an average of 110°. All patients had no extension limitation. The imaging data of bilateral knees during sitting-up movement were collected by biplane C-arm X-ray machine at 3 weeks before operation and 7 months after operation. The three-dimensional models of femur and tibia were established by dual-energy CT scanning, and the three-dimensional models of femur and tibia were matched and synchronized with the femur and tibia in X-ray film by automatic matching tracer software. The biomechanical parameters of femur and tibia were measured, including internal rotation/external rotation, varus/valgus, forward/backward displacement of medial and lateral tibia contact center, and lateral compartment joint space. Results Eight patients were followed up 5-7 months, with an average of 6.4 months. In the comparison of the affected side before and after operation, except for the difference of varus/valgus which was significant (t=4.959, P=0.002), the differences in other indicators was not significant (P>0.05). There were significant differences in varus/valgus and internal rotation/external rotation between healthy and affected sides at 3 weeks before operation (P<0.05), and the differences in other indicators was not significant (P>0.05). At 7 months after operation, the difference in the forward and backward displacement of medial tibia contact center was significant (t=3.798, P=0.007), and the differences in other indicators was not significant (P>0.05). Conclusion UKA can effectively correct the varus and valgus of the knee joint, and restore the rotational biomechanical characteristics of the affected knee joint. It does not affect the establishment of the lateral compartment joint space, but the medial and lateral tibia contact center still changes.
Objective To conclude the research progress of unicompartmental knee arthroplasty (UKA) in the treatment of elderly patients with knee osteoarthritis (KOA). Methods The literature on UKA at home and abroad in recent years was reviewed to summarize the clinical characteristics of elderly patients with KOA, perioperative management (including evaluating indications preoperatively, intraoperative prosthesis selection, postoperative complication management, etc). Results Through reasonable preoperative evaluation, prosthesis selection, and advanced perioperative management, for elderly patients with KOA who meet the indications, UKA can be considered. Compared with total knee arthroplasty, the incidence of postoperative complications in elderly patients undergoing UKA is lower, joint awareness is reduced, functional improvement and satisfaction are higher. Meanwhile, choosing appropriate prostheses and fixation methods can lead to a good survival rate. ConclusionUKA can provide a safe and effective treatment option for elderly patients with KOA within a certain range of indications.