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Objective To explore the proprioception characteristics of knee joints for knee osteoarthritis (KOA) patients before unicondylar knee arthroplasty (UKA) and total knee arthroplasty (TKA). Methods Twenty-nine single-compartment KOA patients were selected. Fifteen patients were treated with UKA (UKA group) and fourteen patients were treated with TKA (TKA group). The test was performed 1 to 3 days before the operation.The keen society scores (KSS) of KOA patients in UKA group and TKA group were compared, and their joint position sense and kinesthesia were compared with control group. Results Significant differences in KSS were found in TKA group and UKA group, and the knee joint position sense and kinesthesia showed no significant differences between TKA group and UKA group.There were no significant differences in the knee joint position sense and kinesthesia between the operated leg and unoperated leg in TKA group and UKA group, and between the left leg and right leg in control group. Compared with control group, there were significant differences between UKA group and TKA group in 60° position sense of the operated leg and unoperated leg.The kinesthesia of the operated leg and unoperated leg in UKA group and TKA group were also significantly different from that in control group. Conclusions Compared with control group, the proprioception of the knee joint in KOA patients was significantly reduced before the surgery, but the characteristics of proprioception in UKA group and TKA group were similar.
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Abstract Introduction The implantable devices are having enormous market. These products are basically made by traditional manufacturing process, but for the custom-made implants Incremental Sheet Forming is a paramount alternative. Single Point Incremental Forming (SPIF) is a manufacturing process to form intricate, asymmetrical components. It forms the component using stretching and bending by maintaining materials crystal structure. SPIF process can be performed using conventional Computer Numerical Control (CNC) milling machine. Review This review paper elaborates the various manufacturing processes carried on various biocompatible metallic and nonmetallic customised implantable devices. Conclusion Ti-6Al-4V alloy is broadly used for biomedical implants, but in this alloy, Vanadium is toxic so this alloy is not compatible for implants. The attention of researchers is towards the non toxic and suitable biocompatible materials. For this reason, a novel approach was developed in order to enhance the mechanical properties of this material. . The development of incremental forming technique can improve the formability of existing alloys and may meet the current strict requirements for performance of dies and punches.
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Varus deformation in knee joint is one of the common symptoms caused by unicompartment knee osteoarthritis. Currently, several operations can be used for correcting such deformation, including high tibial osteotomy, unicondylar knee arthroplasty (UKA) and fibulectomy. UKA has been developed for over 60 years, with the advantage of normal knee kinematics restored, less incision, more bony tissue preserved and larger range of motion than total knee arthroplasty (TKA). Therefore, UKA has become a reliable method for treating unicompartment knee osteoarthritis. Fibulectomy is a new kind of surgical technique for treating varus deformation in knee joint, with the advantage of simple operation, low cost and fast recovery. At present, fibulectomy has been widely applied, but its treatment mechanism is still not clear. In this review, two clinical operations UKA and fibulectomy were summarized, and the possible mechanism of fibulectomy for treating unicompartment knee osteoarthritis was proposed from the viewpoint of biomechanics. The author hypothesized that reduction in lateral muscle force after fibulectomy would cause rebalance of the resultant joint moment, therefore, the change of joint contact position and the decrease in joint contact force might be the cause of fibulectomy to release the pain for knee osteoarthritis patients.
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PURPOSE: To evaluate short-term clinical and radiographical results of fixed bearing unicondylar knee arthroplasty (UKA) comparing results between over-corrected group and under-corrected group. MATERIALS AND METHODS: Clinical and radiographical outcomes of 47 Miller-Galante(R) UKAs with a minimum of 4-year follow-up were evaluated. We also compared both clinical and radiographical results between over and under corrected groups, which were divided by 2degrees varus of mechanical axis postoperatively. RESULTS: HSS and WOMAC scores improved from 75.4 and 57.7 preoperatively to respectively, 95.2 and 12.1 at the last follow up. Radiographically, the mechanical axis changed from 7.2degrees varus preoperatively to 2.8degrees varus at the last follow-up. A partial radiolucent line on the medial side of the tibia was observed in 23% of the 47 cases. Degenerative changes in the lateral compartment and the patellofemoral joint were observed, respectively, in 23% and 26%. There were no significant differences between the two groups in clinical and radiographical results (p>0.05). In the undercorrected group, three cases converted to total knee arthroplasty because of medial tibial collapse. CONCLUSION: Miller-Galante(R) UKA showed good outcomes in short-term follow-up with the exception of three failures. There were no significant differences between more than 2degrees varus corrected and under 2degrees varus corrected groups in clinical and radiographical results. However, all 3 conversions to total knee arthroplasties occurred in the undercorrected group.
Subject(s)
Arthroplasty , Axis, Cervical Vertebra , Follow-Up Studies , Knee , Patellofemoral Joint , Tibia , UrsidaeABSTRACT
[Objective]To explore the short-term outcome and surgical technique of minimally invasive unicondylar knee arthroplasty(MIS-UKA) for medial compartmental osteoarthritis of the knee. [Methods]Forty-five patients(48 knees) with medial compartmental osteoarthritis of knee treated by MIS-UKA from May 2005 to December 2008 were reviewed and analyzed.The pain and range of motion(ROM) of the knees were evaluated by HSS score system before and after MIS-UKA.Pre-and postoperative alignment of the lower limbs was measured and compared.Surgery indications and surgical technique of MIS-UKA were also summarized.[Results]Forty-three knees in 40 patients were followed up for a mean time of 24 months(12-40 months).The pain over medial compartment of the knees was subsided or relieved in all cases.The post-operative ROM of the knees was 0?~135?(mean 120?),and alignment was 2? varus on the average(0?~6? varus).HSS score increased from 70(60~82) to 90(75~95).The good-to-excellent rate was 92%.[Conclusion]MIS-UKA is an effective method for medial compartmental osteoarthritis of the knee.Surgery indications and surgical technique are the key factors for the final results.
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Satisfactory results of unicondylar knee arthroplasty (UKA) have been reported since minimally invasive UKA had been introduced. However, several stress fractures of the tibial plateau, related to instrumentation design, have been reported. We report two cases of periprosthetic stress fractures of the tibial plateau after navigation-assisted unicondylar knee arthroplasties.
Subject(s)
Arthroplasty , Fractures, Stress , KneeABSTRACT
PURPOSE: To evaluate the results of unicondylar knee arthroplasties using minimally invasive surgical(MIS) technique. MATERIALS AND METHODS: During the years 2000 and 2001, 195 unicondylar knee arthroplasties were completed by senior author with the Miller-Galante prosthesis(Zimmer, Warsaw, IN, USA). We analyzed clinical results, flexion/extension gap laxity and the radiological findings. RESULTS: The average preoperative range of motion(ROM) was 122 degrees. At the first follow-up appointment after the surgery, the average ROM was 111 degrees and it was improved to 130.1 degrees at 1-year follow up. The preoperative hospital for special surgery score was 53.8 and it was improved 92.4 postoperatively. The average extension gap for all of the surgeries was 1.47 mm and the flexion gap was 1.82 mm. The average correction of overall alignment on the follow-up x-rays was 3.9 degrees for the varus knees. The x-rays showed an increase of distal femoral valgus angle(1.79 degrees ) with 6 mm cut than with the 8mm cut(0.37 degrees ). The average proximal tibial varus angle was decreased from 5.45 degrees to 2.11 degrees and the average posterior slope of proximal tibia was decreased from 7.2 degrees to 4.5 degrees . CONCLUSION: Unicondylar knee arthroplasty by MIS technique guarantees early recovery and satisfactory radiological results. Therefore, long term follow-up evaluation is necessary.