Enoxaparin versus No Anticoagulation Prophylaxis after Total Knee Arthroplasty in Thai Patients: A Randomized Controlled Trial.

Background: There has been some controversy about routine use of thromboprophylaxis after total knee arthroplasty (TKA) in Asian patients. Objective: To compare the efficacy and safety of enoxaparin in preventing venous thromboembolic diseases after TKA in Asian patients. Material and Method: We randomized 50 patients undergoing primary TKA into two equal groups, 25 patients received once daily subcutaneous enoxaparin injections as thromboprophylaxis and 25 control patients did not receive anticoagulation. The primary outcome was deep vein thrombosis (DVT) identified by color Doppler ultrasonography and/or pulmonary embolism (PE). All significant bleeding complications were recorded. Results: Deep vein thrombosis occurred in only one patient in the control group (4%) and in none in the enoxaparin group (0%, p = 0.31). No patient in both groups had clinical signs of PE. No patient had significant bleeding complications. One patient in enoxaparin group had a minor bleeding complication (4%) and also a surgical wound complication. Conclusion: We concluded that the incidence of thromboembolic diseases after primary TKA in Thai patients is very low. Enoxaparin had no significant benefit in reducing venous thromboembolic complications after TKA in Asian patients, however it is safe in term of bleeding complications. We do not recommend routine use of enoxaparin as thromboprophylaxis after TKA in Asian patients.

Predictive factors for deep medial collateral ligament release in adjusted mechanical alignment total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) demands precision in achieving optimal alignment and soft tissue balance, especially in cases of medial compartment osteoarthritis where the need for medial soft tissue release is critical yet challenging to ascertain. OBJECTIVE: This study aims to systematically investigate the relationship between preoperative data, initial knee conditions and the necessity for deep collateral ligament (MCL) release in adjusted mechanical alignment total knee arthroplasty. METHODS: We conducted a retrospective study involving 61 TKA patients who underwent adjusted mechanical alignment robotic-assisted procedures. Soft tissue release was carried out when clinically indicated. We collected and statistically analyzed patient demographics, initial knee conditions, and surgical details. RESULTS: Among the patients, 52% required deep MCL release. Notably, patients without soft tissue release exhibited lower initial hip-knee-ankle (HKA) angles, reduced varus-valgus stress test angles, and a greater range of flexion. We identified a predictive threshold HKA angle of 6.250 degrees, demonstrating high sensitivity and specificity for determining the need for deep MCL release. CONCLUSION: This study underscores the significance of the initial HKA angle and varus-valgus stress tests in predicting deep MCL release during TKA. The established HKA angle threshold simplifies surgical decision-making, reducing the likelihood of unnecessary soft tissue release.

One- vs two stage surgery technique for implant placement in finger prosthesis.

BACKGROUND: The loss of the finger can lead to psychological problems. Although several reconstructive techniques may exist, the use of osseous-integrated implants to anchor digital prosthesis presents a suitable alternative for the amputation of finger. The surgery for implant placement has initially been described as a two-stage technique. However, no study in the literature has attempted to compare this technique with one-stage technique and stated a clear superiority technique in the implant retained finger prosthesis. METHODS: This article describes two cases of digital amputation as a result of accident; a 45-year-old female whose second finger of right hand was lost and a 25-year-old male patient with amputation of the first finger of right hand. RESULT AND CONCLUSION: One-stage implant placement technique for implant retained finger prosthesis is a reliable, safe and efficient option that allows a good result in a significantly lower operating time and hospital visits compared to the two-stage technique. It could therefore, be considered as good option for implant retained finger prosthesis.

Stress distribution in implant retained finger prosthesis: a finite element study.

BACKGROUND: Finger amputation may result from congenital cause, trauma, infection and tumours. The finger amputation may be rehabilitated with dental implant-retained finger prosthesis. The success of implant-retained finger prosthesis is determined by the implant loading. The type of the force is a determining factor in implant loading. OBJECTIVE: To evaluate stress distributions in finger bone when the loading force is applied along the long axis of the implant using finite element analysis. METHOD: The finite element models were created. The finger bone model containing cortical bone and cancellous bone was constructed by using radiograph. Astra Tech Osseo Speed bone level implant of 4.5 mm diameter and 14 mm length was selected. The force was applied to the top of the abutment along the long axis of the implant. RESULTS: Finite element analysis indicated that the maximum stress was located at the head of abutment screw. The minimum stress was located in the apical third of the implant fixture. The weakest point was calculated by safety factor which is located in the spongy bone at apical third of the fixtures. Finally, 4.9 times yield stress of spongy bone was needed for the deformation of the spongy bone. CONCLUSION: Finite element study showed that when the force was applied along the long axis of the implant, the maximum stress was located around the neck of the implant and the cortex bone received more stress than cancellous bone. So, to achieve long term success, the designers of implant systems must confront biomaterial and biomechanical problems including in vivo forces on implants, load transmission to the interface and interfacial tissue response.