Mid-term Results of Single-Radius Cruciate Retaining Total Knee Arthroplasty: Minimum 5 Year Follow-up

PURPOSE: The single-radius design of the knee implant was introduced to improve the results of total knee arthroplasty (TKA) by reducing maximum extensor forces, and it also represents more physiologic quadriceps force pattern, which could have a positive effect on knee function after TKA. We studied mid-term results of single-radius designed cruciate retaining (CR) TKA. MATERIALS AND METHODS: We analyzed the functional improvement and radiological osteolytic pattern after TKA using the single-radius Scorpio CR prosthesis. TKA was performed on 102 knees. The mean follow-up period was 73.8 months. For clinical assessment, the range of motion (ROM), Harris hip score, and functional outcome score were obtained preoperatively and at last follow-up. RESULTS: The average ROM was 100.2° preoperatively and 121.7° at last follow-up. The average knee score was 59.2 points preoperatively and 92.9 points at last follow-up. The average functional outcome score was improved from 51.9 points preoperatively to 85.4 points at last follow-up. Radiolucency was observed in four knees but all were non-progressive lesions smaller than 2 mm. CONCLUSIONS: The clinical outcome of TKA using the single-radius CR prosthesis was good during the mid-term follow-up and the incidence of osteolysis was very rare

A case of bilateral revision total knee arthroplasty using distal femoral allograft–prosthesis composite and femoral head allografting at the tibial site with a varus-valgus constrained prosthesis: ten-year follow up

Abstract Background We report the successful use of allograft–prosthesis composite (APC) and structural femoral head allografting in the bilateral reconstruction of large femoral and tibial uncontained defects during revision total knee arthroplasty (RTKA). Case presentation A 67-year-old female with degenerative arthritis underwent bilateral total knee arthroplasty (TKA) using the Press Fit Condylar (PFC) modular knee system at our clinic in March, 1996. At 8 years postoperatively, the patient presented with painful, bilateral varus knees, with swelling, limited passive range of motion (ROM), and severe instability. We treated to reconstruct both knee using a femoral head allograft at the tibial site, a structural distal femoral allograft at the femoral site, and a varus-valgus constrained (VVC) prosthesis with cement. At the 10-year follow up, we found no infection, graft failure, loosening of implants, in spite of using massive bilateral structural femoral head allografts in RTKA. Conclusion The use of APC enabled a stable and durable reconstruction in this uncommon presentation with large femoral bone deficiencies encountered during a RTKA

Quantitative assessment of neural elements in rat model using nerve growth factor after remnant-preserving anterior cruciate ligament reconstruction: a hematoxylin and eosin stain and immunohistochemical study

Abstract Background: Immunohistochemical analyses of anterior cruciate ligament (ACL) allografts following remnant-preserving ACL reconstructions using Achilles tendon allografts have provided evidence for the presence of neural elements. In this study, we aimed to examine the expression of neural elements and quantify the presence of neural cells in ACL remnants and Achilles allografts using nerve growth factor (NGF) therapy after remnant-preserving ACL reconstruction. Methods: Experiments were conducted on 5 pairs of rats (approximately 8 weeks old and weighting 320 g at the time of surgery). Longitudinally-split Achilles tendons from the paired rats were freshly frozen and later defrosted with warm saline and allografted onto the right ACL of the other, which was partially detached at the femoral attachment site. A sham operation was conducted on the left knee to be used as Control. NGF was injected in both the knee joints 1 week after surgery. The presence of neural cells in the ACL of the sham-operated knee, allografted Achilles tendon, and ACL remnant was examined 6 weeks post surgery using H and E and immunohistochemical staining. Results: H and E staining did not reveal neural cells in any of the three groups. However, immunohistochemical analysis showed the presence of nestin-positive neural elements in normal ACL as well as ACL remnants. Additionally, neural elements were examined in 7 of the 8 (87.5%) allograft tissues. Quantitative analysis showed no difference in the number and area of nuclei among the three groups. However, the number and area of neural cells in Achilles allograft were significantly lower than in the other two groups (p=0.000 and p=0.001, respectively). Conclusion: Our observations indicate that ACL remnants promote new ingrowth and persistence of neural cells. We suggest that the ingrowth of neural elements could support the persistence and new ingrowth of mechanoreceptors, thereby enhancing the functional stability of knee joints. Moreover, the expression of neural cells in Achilles allograft was lower than that of normal ACL or ACL remnants in the quantitative evaluation, thereby confirming the essential role of ACL remnants in knee joint functionalization. Key terms: anterior cruciate ligament, remnant preservation, immunohistochemistry, nerve growth factor</jats:p