Intentionally Increased Flexion Angle of the Femoral Component in Mobile Bearing Unicompartmental Knee Arthroplasty.

PURPOSE: The purpose of this study was to determine the results of mobile bearing unicompartmental knee arthroplasty (UKA) with an intentionally increased flexion angle of the femoral component in patients requiring high flexion. MATERIALS AND METHODS: We investigated 45 knees treated by UKA. Clinically, we measured the range of motion (ROM) and the American Knee Society (AKS) score preoperatively and at final follow-up and investigated complications. Radiologically, we measured the flexion angle of the femoral component, the posterior slope angle of the tibial component, the femorotibial angle and mechanical axis of the limb postoperatively. RESULTS: The ROM was increased from 123° preoperatively to 139° at the final follow-up. The AKS knee and function scores increased from 59 and 68, respectively, preoperatively to 94 and 96, respectively, at the final follow-up. The flexion angle of the femoral component was 9.1°, and the posterior slope angle of the tibial component was 8.6°. There was one case of bearing dislocation in the largest femoral flexion angle case. CONCLUSIONS: The results might reflect the positive effect of an increased flexion angle of the femoral component up to 10° on ROM in mobile bearing UKA, which would contribute to better quality of life after UKA especially in populations requiring deep knee flexion.

Does Cruciate-Retaining Total Knee Arthroplasty Show Better Quadriceps Recovery than Posterior-Stabilized Total Knee Arthroplasty? - Objective Measurement with a Dynamometer in 102 Knees.

BACKGROUND: Cruciate-retaining (CR) prostheses have been considered to produce more physiologic femoral rollback, provide better proprioception, and result in better quadriceps recovery than posterior-stabilized (PS) prostheses after total knee arthroplasty (TKA). However, there are very few studies demonstrating these benefits in an objective manner. We investigated whether CR-TKA could result in (1) better quadriceps recovery; (2) a greater proportion of patients with beyond the preoperative level of recovery; and (3) better clinical outcomes than PS-TKA. METHODS: This was a prospective non-randomized comparative study on the results of CR-TKA and PS-TKA. CR prostheses were used in 51 knees and PS prostheses in 51 knees. Quadriceps force was measured with a dynamometer preoperatively and at postoperative 6 weeks, 3 months, and 6 months consecutively. The Knee Society score (KSS) and range of motion (ROM) were also evaluated. RESULTS: There were no differences between two groups in terms of the objective quadriceps force during the follow-up period. The proportion of patients with beyond the preoperative level of recovery was similar between groups. Moreover, the KSS and ROM were not significantly different between two groups. CONCLUSIONS: CR-TKA did not result in better quadriceps recovery than PS-TKA during the 6-month follow-up. In other words, PS-TKA could lead to comparable quadriceps recovery despite greater preoperative weaknesses such as more restricted ROM and more severe degenerative changes of the knee.

Osteochondroma Arising from Anterior Inferior Iliac Spine as a Cause of Snapping Hip.

Snapping hip syndrome is a relatively common problem that can be easily managed with conservative treatment. This syndrome can be divided into external, internal and intra-articular types. Internal snapping hip syndrome is the rarest amongst these and its etiology is not well understood. We report a unique case of osteochondroma arising from the anterior inferior iliac spine (AIIS), which caused the internal snapping hip syndrome with hip pain and restriction of activity. This rare case of snapping hip syndrome from the AIIS was treated surgically and the symptoms completely disappeared after excision of the tumor.

Compartment syndrome following total knee arthroplasty: clinical results of late fasciotomy.

Compartment syndrome after total knee arthroplasty (TKA) is a rare complication. Because of its rarity, it may be overlooked and misdiagnosed as peroneal nerve palsy or deep vein thrombosis. This misdiagnosis could have a profound impact on the patient's outcome. We report a case of a 77-year-old female who developed unilateral compartment syndrome in the calf after staged bilateral TKA at an outside clinic. The patient presented with medical complications related to compartment syndrome: rhabdomyolysis and myoglobinuria, which caused acute renal failure. Thus, we performed late fasciotomy one week after symptom onset to debride necrotic tissue and salvage the compartment. In the discussion section, we will discuss risk factors for compartment syndrome after TKA, results of late fasciotomy and other indications for surgical treatment of compartment syndrome.

Better quadriceps recovery after minimally invasive total knee arthroplasty.

PURPOSE: The proponents of minimally invasive total knee arthroplasty (TKA) have reported better functional recovery than conventional TKA. In most of the previous studies, the results were shown with the relatively subjective methods. We investigated the objective results with a dynamometry in this prospective randomized study. It was hypothesized that minimally invasive TKA would have a better and earlier recovery of quadriceps force in terms of the objective numeric data. METHODS: Sixty-six TKAs were prospectively randomized into two groups. Thirty-three knees underwent minimally invasive TKA using mini-midvastus approach and 33 knees underwent conventional TKA using medial parapatellar approach. The quadriceps force was assessed using a dynamometer. The data were collected preoperatively and at postoperative 6 weeks, 3 months, 6 months and 1 year consecutively. RESULTS: The mean of quadriceps force in minimally invasive TKA group at postoperative 6 weeks was greater than conventional TKA after removing the covariate (preoperative quadriceps force) with analysis of covariance (P = 0.002), but thereafter, the difference was not significant till 1 year. Meanwhile, with repeated measures analysis of variance, conventional TKA group had greater quadriceps recovery than minimally invasive TKA group during postoperative 6 weeks to 3 months (P = 0.035). The proportion of patients unable to recover the quadriceps force to their preoperative levels by 1 year postoperatively was similar in two groups. CONCLUSION: Minimally invasive TKA has benefit in quadriceps recovery at earlier rehabilitation period although catch-up recovery in conventional TKA was accelerated from the postoperative 6 weeks to 3 months. It may support the concept of early return to full activity after minimally invasive TKA, and patients might get back early to normal life.

Treatment of Schatzker Type V and VI Tibial Plateau Fractures Using a Midline Longitudinal Incision and Dual Plating.

PURPOSE: The purpose of this study was to evaluate the results of the treatment of Schatzker type V and VI tibial plateau fractures using a midline longitudinal incision and dual-plate fixation. MATERIALS AND METHODS: Ten patients with Schatzker type V and VI tibial plateau fractures treated with a midline longitudinal incision and dual plating were analyzed. The patients were followed for a minimum of one year. Clinical outcomes were evaluated using range of motion, visual analogue scale (VAS) and Knee Society Score. Radiological outcomes were evaluated using the bony union time, medial proximal tibial angle (MPTA) and posterior proximal tibial angle (PPTA). RESULTS: The mean VAS score was 2.2 points, and the mean Knee Society function score was 85 points at the final follow-up. The mean flexion contracture was 2.5° and the mean further flexion was 125°. It took an average of 4 months until bony union occurred. The mean MPTA and PPTA were 90.5° and 4.4°, respectively. There was one case of delayed wound healing, but no other complications were observed. CONCLUSIONS: The treatment of Schatzker type V and VI tibial plateau fractures with a midline longitudinal incision and dual-plate fixation resulted in satisfactory clinical and radiological outcomes. This can be an option when treating Schatzker type V and VI tibial plateau fractures.

Is routine chemoprophylaxis necessary for prevention of venous thromboembolism following knee arthroplasty in a low incidence population?

BACKGROUND: Standard thromboprophylaxis guidelines have not been applied universally in regions with low incidence of deep-vein thrombosis (DVT) considering risks of chemoprophylaxis and low incidence itself. We evaluated the prevalence of DVT, efficacy and safety of chemoprophylaxis, and necessity of pharmacological prevention in a low DVT incidence population. METHODS: One hundred and forty-eight patients undergoing unilateral total knee arthroplasty (TKA) were prospectively randomized to receive either a placebo or 2.5 mg of fondaparinux once daily for 5 days. Doppler ultrasonography was performed preoperatively and 7 days after surgery. The primary efficacy outcome was prevalence of DVT up to day 7. Secondary efficacy outcome was prevalence of symptomatic venous thromboembolism (VTE) up to day 90. Primary and secondary safety outcomes were incidence of major and minor bleeding, respectively. RESULTS: The prevalence of total DVT was 25.7 % in placebo group and 6.8 % in fondaparinux group (p = 0.002) and the prevalence of proximal DVT was lower in both groups with no statistical difference. There was no symptomatic VTE in either group up to day 90. Although no major bleeding was developed, fondaparinux group had a significant increase of minor bleeding events (p < 0.001). CONCLUSIONS: There remains low incidence of VTE following TKA in East Asians even without chemoprophylaxis. Although short-term fondaparinux protocol could reduce the incidence of overall DVT, its routine use seems debatable due to extremely rare proximal DVT and symptomatic PE and drug-related bleeding complication. However, modified and selective use of chemoprophylaxis would be considerable in high risk patients.

Less blood loss under concomitant administration of tranexamic acid and indirect factor Xa inhibitor following total knee arthroplasty: a prospective randomized controlled trial.

PURPOSE: The objective of this prospective randomized controlled trial was to assess the efficacy and safety of simultaneous application of tranexamic acid and indirect factor Xa inhibitor following total knee arthroplasty (TKA). METHODS: Seventy-two primary osteoarthritis patients undergoing unilateral TKA using fondaparinux as a basic thromboprophylaxis were randomized to receive either placebo (36 patients) or tranexamic acid (36 patients). Prophylaxis against venous thromboembolism in all patients was administered with subcutaneous doses of 2.5 mg fondaparinux for 5 days post-operatively. Post-operative retransfusion volume, allogenic transfusion volumes and drain amount were recorded for each patient. Level of haemoglobin, prothrombin time, activated partial thromboplastin time and D-dimer were also assessed. Doppler ultrasonography was performed preoperatively and 7 days after surgery. RESULTS: The rate of transfusion was lower in the tranexamic acid group than in the placebo group (p = 0.007). The drained blood volume during the initial 24 h and until drain removal was smaller in the tranexamic acid group than in the placebo group (p < 0.001). However, the haematologic laboratory results did not show any significant differences between the two groups. The prevalence of deep-vein thrombosis (DVT) was 4 (11.1 %) in the placebo group and 3 (8.3 %) in the tranexamic acid group (p = n.s.). There was no proximal DVT and no symptomatic pulmonary embolism in either group. CONCLUSION: The use of tranexamic acid could reduce acute blood loss significantly without any adverse effect resulted from drug interaction with concomitant use of indirect factor Xa inhibitor following TKA. Therefore, simple combination of these drugs can be recommended to reduce post-operative blood loss as well as to reduce DVT following TKA.

Patellar eversion does not adversely affect quadriceps recovery following total knee arthroplasty.

Although avoiding patellar eversion during a total knee arthroplasty (TKA) has theoretical benefit in quadriceps recovery, there has been paucity of supportive objective clinical results. We prospectively designed the study whether TKA without patellar eversion has better quadriceps recovery in an objective, dynamometer study. Seventy-two knees undergoing TKA with midvastus approach were randomized into two groups according to patellar eversion or not. Clinical data and objective quadriceps recovery using a dynamometer were investigated preoperatively and postoperative at 6weeks, 3months, 6months and 1year. There were no statistical differences between two groups throughout the follow-up periods in recovery of quadriceps force or power and clinical data. Choosing to evert patella during TKA using midvastus approach would not adversely affect postoperative quadriceps recovery.

Recent Korean perspective of deep vein thrombosis after total knee arthroplasty.

This prospective study was performed on 311 consecutive knees in 227 patients for total knee arthroplasty. The aim was to assess the recent incidence of deep vein thrombosis (DVT) after total knee arthroplasty without chemoprophylaxis in Koreans, the efficacy of plasma d-dimer levels as a screening test, and the associated risk factors. Deep vein thrombosis was found in 79 knees (26.60%). There were 9 cases (3.03%) of proximal DVT, 70 cases (23.57%) of distal DVT, and no symptomatic pulmonary embolism. Although this cohort had limited number of patients by a single surgeon, there is still low incidence of proximal DVT in Koreans with rare pulmonary embolism occurrence compared with those of the Western. High postoperative d-dimer levels were correlative, but no appropriate cutoff value was found. Obesity was a significant associated risk factor.