Introduction: The majority of implants available in the market today were designed to allow for a flexion up to 130 degree angle. The LPS Flex was designed to accommodate deep flexion, up to 160 degree angle. The purpose of this study is to evaluate the clinical result of the LPS Flex knee.

Materials and Methods: From January 1999 to Dec 2006, 1773(Over seventeen hundred) surgeries were performed on patients treated for advanced osteoarthritis. All the surgeries were carried out by the same surgeon. The majority of the patients had bilateral total knee replacements simultaneously. Pre-operative ranges of motion were documented on lateral x-ray. Patients were considered to have full flexion if they were able to fix the knee to at least 130 degree angle sit on the ground with calf touching thigh for at least one minute.

Results: 61% obtained full flexion as defined above. The majority of the cases with full flexion had full movement pre-operatively, except for 116 cases. Some complications were reported. There were 6 cases of peroneal nerve palsy, five of dislocation, and three of infection. There was also two case of rupture of MCL ligament, a case of intraoperative tibial plateau fracture and six of supracondylar femur fracture. Five revisions were performed.

Conclusion: The LPS Flex Implant had a similar complication rate to those reported by other series. There was no complication that could be specifically attributed to deep flexion, in general, it should be stressed that this exceptional result has to do mainly with careful patient selection.

The majority of papers covering MIS total knee describe a surgical approach where the quads tendon is violated. This presentation describes a modified subvastus approach using MIS technique. The results are compared to the regular subvastus approach.

Material and methods: 423 total knee replacements were performed through MIS subvastus approach from November 2002 to February 2004. All cases were performed by the same surgeon. The subvastus approach was modified to allow more quads excursion so the surgery can be performed without dislocating the patella. The data was processed at University of Dundee. The results were compared to the results of 361 cases of standard subvastus approach performed by the same surgeon.

Kanasaki et al. (ISTA 2002) has shown that patients who had subvastus approach were able to regain the ability to do a straight leg raising faster than the standard parapateller incision. The results in this paper confirm the same showing that the ability of patients to rehabilitate is not related only to the size of the incision. Having relatively small incisions help in shorten hospital stay but did not make any difference in blood loss. The subvastus approach the only true quad sparing approach and it can be performed through 10 cm incision safely even in heavy patients with severe knee deformity.

The majority of implants available in the market today were designed to allow for a flexion up to 130 degree angle. The LPS Mobile Flex was designed to accommodate deep flexion, up to 160 degree angle. The purpose of this study is to evaluate the clinical result of the LPS Mobile Flex knee.

From January 1999 to February 2004, 635 surgeries were performed on patients treated for advance osteoporosis. All the surgeries were carried out by the same surgeon. The majority of the patients had bilateral total knee replacements simultaneously. Pre-operative ranges of motion were documented on lateral x-ray. Patients were considered to have full flexion if they were able to fix the knee to at least 140 degree angle sit on the ground with calf touching thigh for at least one minute.

68% obtained full flexion as defined above. The majority of the cases with full flexion had full movement pre-operatively, except for 26 cases. Some omplications were reported. There were 2 cases of personal nerve palsy, three of dislocation, and one of infection. There was also a case of rupture of MCL ligament, a case of intra-operative tibial plateau fracture and one of upra-condyler femur fracture. No revision was performed. There were no patella complications

The LPS Flex Implant had a similar complication rate to those reported by other series. There was no complication that could be specifically attributed to deep flexion. Surprisingly, there were no patella complications and the implant, in general, had an excellent clinical outcome as far as mobility. However, it should be stressed that this exceptional result has to do mainly with careful patient selection.

Introduction Full flexion is important for daily living activities in Asian societies. The purpose of this presentation is to discuss our experience with full flexion after knee replacement in over 900 cases and to address some areas of concern.

Materials and Methods 911 cases were performed on 492 patients. LPS flex implants were used; all surgeries were performed by a single surgeon between December 1999 and august year 2004. Data was processed at University of Dundee in Scotland. MIS subvastus approach was used. Full flexion was defined as a flexion of over 135 degree with the ability to kneel on the ground, calf touching thigh for at least one minute. X-ray review was carried on cases with more than 2 years of follow up.

Results 67% of patients were able to get full flexion after surgery. The majority of those cases had full flexion pre-operatively. The results were compared with the data base at University of Dundee: our patients has significantly better flexion than the data base yet the knee score was almost the same .Complication rates were the same and there was no complication that can be attributed to deep flexion.

Discussion The result clearly shows that in spite of the fact that patient has a better range of motion the knee score failed to capture the improvement of patient function. It is unfortunate that we still do not have a universal way to describe the activities of deep flexion and no objective methods to assess the importance of deep flexion on daily activities. There is still great need to improve our understanding of the biomechanics of deep flexion so we can choose proper implants for our patients. Our x-ray review shows that mobile bearing is better choice in accommodating the lateral femoral condyle subluxation that happens with deep flexion and we were able to document that on 3D images.

Conclusion Full flexion is achievable and safe after TKA. Further work will be needed to develop new ways to asses function after TKA and to further modify the implant to accommodate deep flexion.