Efficacy of pulse oximetry for early diagnosis of pulmonary embolism after total knee arthroplasty.

INTRODUCTION: Early diagnosis and aggressive treatment of pulmonary embolism (PE) are crucial for preventing severe complications after total knee arthroplasty (TKA). This study aimed to examine the efficacy of measuring oxygen saturation (SpO2) using a pulse oximeter for early diagnosis of PE after total knee arthroplasty (TKA). MATERIALS AND METHODS: We consecutively examined 1645 patients who underwent TKA between January 2015 and November 2019. Postoperative SpO2 was measured with a pulse oximeter, which was stopped if SpO2 was maintained at ≥ 95% until postoperative day 2 (POD2). To diagnose PE, computed tomographic pulmonary angiography (CTPA) was performed for specific indications, including persistently low SpO2 < 95% (group 1), sudden decrease in SpO2 (group 2), and decrease in SpO2 after POD3 with presenting symptoms (group 3). Also, we divided the patients into unilateral, simultaneous and sequential TKA groups and compared the results with specific statistical techniques. RESULTS: Of the 1645 patients who underwent TKA, there were 20 patients with PE (1.2%), and symptomatic PE was observed in only 4 patients (0.24%). CTPA was performed in 58 (3.5%) patients, of whom 20 were diagnosed with PE. In groups 1 (n = 34), 2 (n = 21), and 3 (n = 3), CTPA was performed 2.4, 2.6, and 8.3 days after TKA, respectively, and 12, 8, and 0 patients were diagnosed with PE, respectively. Of the 782, 416, and 447 unilateral, simultaneous, and sequential (done in same admission with interval 1 or 2 weeks) patients with TKA, 38, 18, and 2 received CTPA, and 13, 6, and 1 were diagnosed with PE, respectively. All patients diagnosed with PE have persistently low SpO2 < 95% (group 1), or sudden decrease in SpO2 (group 2) until POD2. Of the patients diagnosed with PE, SpO2 decreased without the presentation of symptoms in 16 patients (11 and 5 from groups 1 and 2, respectively) and with the presentation of symptoms, such as mild dyspnea and chest discomfort, in 4 patients (1 and 3 from groups 1 and 2, respectively). CONCLUSIONS: Measuring SpO2 using a pulse oximeter until POD2 was an effective method for early diagnosis of PE after TKA. No case of morbidity or mortality was observed after early diagnosis with early stage CTPA and management of PE. We recommend measuring SpO2 with a pulse oximeter for early diagnosing of PE in TKA.

The Incidence Rate, Microbiological Etiology, and Results of Treatments of Prosthetic Joint Infection following Total Knee Arthroplasty.

Periprosthetic joint infection (PJI) remains among the most challenging and costly complications. PJI rates vary from 0.39% to 3.9% after total knee arthroplasty (TKA). This study aimed to identify the causative microorganisms involved and to report our experience of subsequent treatment of PJI following over 7000 TKAs performed over 19 years. A retrospective study was conducted on 4547 patients (7019 cases) from March 2000 to September 2019. The incidence rate of PJI was 0.5%. Gram-positive bacteria accounted for 88.8% (n = 16) of the 18 cases, and S. aureus was the most commonly isolated pathogen (n = 7, 38.8%). There were six cases of MSSA and one case of MRSA. Streptococcus species (n = 7, 38.8%) also showed the same pattern. The CoNS species (n = 2, 11.1%) and Gram-negative bacteria (n = 1, 5.5%) were also reported. Candida species were isolated from 1 patient (5.5%). Successful I&D and implant retention (DAIR procedures) was achieved at the final follow-up in 19 patients (82.6%). The incidence of causative microorganisms was different for each PJI onset type. The overall infection rate of PJI was less than 1%. Although the success rate of DAIR procedures is lower than the two-stage exchange arthroplasty in this study, it is possible to achieve acceptable success rates if DAIR procedures are carefully selected considering the virulence of the microorganism, duration since symptom onset, and early-onset infection.

Intra-Articular Injection of a Novel DVS Cross-Linked Hyaluronic Acid Manufactured by Biological Fermentation (YYD302) in Patients With Knee Osteoarthritis: A Double-Blind, Randomized, Multicenter, Noninferiority Study.

PURPOSE: This double-blind, randomized, Phase III clinical trial was conducted to assess the efficacy and safety of the novel divinyl sulfone cross-linked hyaluronate (YYD302) compared with the 1,4-butanediol diglycidyl ether cross-linked hyaluronate (Synovian) in patients with knee osteoarthritis. METHODS: A total of 184 patients with osteoarthritis (Kellgren-Lawrence grade I-III) were randomized to 1 of 2 study groups (YYD302 group, n = 95; Synovian group, n = 89). A single injection of YYD302 or Synovian was given to both groups, and 182 participants completed the study (YYD302 group, n = 95; Synovian group, n = 87). The primary end point was the change in weight-bearing pain (WBP) at 12 weeks after the primary single injection. Secondary end points included the Knee Injury and Osteoarthritis Outcome Score; the Western Ontario and McMaster Universities Osteoarthritis Index score; the Patient Global Assessment and Investigator Global Assessment; the range of motion, swelling, and tenderness of the target knee; OMERACT-OARSI responder rate; WBP responder rate (the proportion of patients achieving at least 20 mm or 40% decrease in WBP); and rate of rescue medicine use and its total consumption at weeks 2, 4, and 12. Based on the efficacy results at week 12, the responders were administered an additional single injection of the same study drug at week 24, and safety and efficacy were additionally assessed at week 36. FINDINGS: Mean changes of WBP at 12 weeks after the primary injection were -31.76 mm with YYD302 and -29.74 mm with Synovian, proving noninferiority of the YYD302 group to the Synovian group as the lower bound of the 95% CI (-4.3 to 8.3) was well above the predefined margin (-10 mm). At week 2, the Knee Injury and Osteoarthritis Outcome Score (total, pain, activities of daily living, and sports/recreation) and Western Ontario and McMaster Universities Osteoarthritis Index scores (total, stiffness) were significantly better in the YYD302 group than in the Synovian group. There were no significant differences between the groups in all other end points. Local overall adverse events (pain, heat, erythema, or swelling) at the injection site were observed in 48.4% of the YYD302 group and in 47.7% of the Synovian group. No serious reactions were reported. There was no statistically significant difference between the 2 groups regarding re-injected patients (YYD302 group, n = 54; Synovian group, n = 46) in any of the efficacy outcomes at week 36. IMPLICATIONS: The results of this study support that YYD302 is comparable to Synovian in terms of the efficacy and safety of the intra-articular injection treatment for osteoarthritis of the knee joint. Furthermore, YYD302 provided faster improvements in some efficacy assessments compared with Synovian. ClinicalTrials.gov identifier: NCT03561779.

Incidence and risk factors analysis for mortality after total knee arthroplasty based on a large national database in Korea.

This study aimed to analyze the rates and risk factors of postoperative mortality among 560,954 patients who underwent total knee arthroplasty (TKA) in Korea. The National Health Insurance Service-Health Screening database was used to analyze 560,954 patients who underwent TKA between 2005 and 2018. In-hospital, ninety-day, and one-year postoperative mortality, and their association with patient's demographic factors and various comorbidities (ie., cerebrovascular disease, congestive heart failure, and myocardial infarction) were assessed. In-hospital, ninety-day and one-year mortality rates after TKA were similar from 2005 to 2018. The risk of in-hospital mortality increased with comorbidities like cerebrovascular disease (hazard ratio [HR] = 1.401; 95% confidence interval [CI] = 1.064-1.844), congestive heart failure (HR = 2.004; 95% CI = 1.394 to 2.881), myocardial infarction (HR = 2.111; 95% CI = 1.115 to 3.998), and renal disease (HR = 2.641; 95% CI = 1.348-5.173). These co-morbidities were also independent predictors of ninety-day and one-year mortality. Male sex and old age were independent predictors for ninety-day and one-year mortality. And malignancy was risk factor for one-year mortality. The common preoperative risk factors for mortality in all periods were male sex, old age, cerebrovascular disease, congestive heart failure, myocardial infarction, and renal disease. Malignancy was identified as risk factor for one-year mortality. Patients with these comorbidities should be provided better perioperative care.

Radiographic Prognostic Factors Relevant to Surgical Outcomes of Arthroscopic Partial Medial Meniscectomy in Elderly Patients with Mild Osteoarthritis.

The aim of this study was to investigate radiographic factors relevant to predict surgical outcomes of arthroscopic partial meniscectomy (APM) in elderly patients with mild osteoarthritis (Kellgren-Lawrence grades 1 and 2). Data of 172 consecutive patients aged >70 years who underwent arthroscopic meniscal surgery were reviewed retrospectively. The patients who met the inclusion criteria were classified into two groups based on the minimal clinically important difference value of the Lysholm knee scoring scale comparing the score of the last visit with that of the preoperative period: group 1 (with clinically significant improvement) and group 2 (without clinically important change). Radiographic factors assessed on X-ray and magnetic resonance images were evaluated using bivariate and logistic regression analyses. A total of 73 patients were included in this study. Bivariate analysis revealed that the extent of meniscus extrusion (p = 0.031), meniscus extrusion ratio (p = 0.001), and grade of meniscus degeneration (p = 0.019) were significantly different between the groups. Multivariate logistic regression analysis showed that the meniscus extrusion ratio was the most important independent predictive factor for surgical outcomes with clinically important changes (coefficient = 0.159, p = 0.009). On receiver operating characteristic (ROC) curve analysis, the cutoff point of the meniscus extrusion ratio discriminating the two groups was 34.2% (sensitivity: 79.3%; specificity: 68.6%; accuracy: 72.6%). Meniscus extrusion ratio was the most relevant predictive factor for discriminating patients with clinically important change. Meniscus extrusion ratio, with the cutoff point of 34.2%, could serve as a guide to determine whether to perform APM in elderly patients with mild osteoarthritis. This is a Level IV, therapeutic case series study.

Risk factors of postoperative complications following total knee arthroplasty in Korea: A nationwide retrospective cohort study.

BACKGROUND: The number of patients undergoing total knee arthroplasty (TKA) is gradually increasing and there is also increase in postoperative complications. The patient's demographic, socio-economic factors, hospital and clinical factors are all factors that can influence postoperative complications. The purpose of this study was to determine the risk factors associated with complications following TKA in a large national cohort. METHODS: Among patients diagnosed with primary knee arthrosis, a total of 560,954 patients older than 50 years who underwent TKA from January 1, 2005 to December 31, 2018 were included in the study. The risk of postoperative complications (surgical site infection, sepsis, cardiovascular complications, respiratory complications, pulmonary embolism, stroke, acute renal failure, periprosthetic joint infection, and periprosthetic fracture) were assessed with eight independent variables: gender, age, place of residence, household income, hospital bed size, procedure type (unilateral or bilateral, primary or revision TKA), length of stay (LOS), use of transfusion. Multivariable Cox Proportional Hazard model analysis was used. The significant predictors for complications (P < .05) were as follows. RESULTS: Surgical site infection: male, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Sepsis: male, household income, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Cardiovascular complications: male, age, household income, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Respiratory complications: male, household income, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Pulmonary embolism: male, household income, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Stroke: male, age, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Acute renal failure: male, household income, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Periprosthetic joint infection: male, household income, procedure type (bilateral, revision), LOS (≥35 days), transfusion. Periprosthetic fracture: male, procedure type (bilateral, revision), LOS (≥35 days), transfusion. CONCLUSION: In summary, male, procedure type (bilateral, revision), LOS (≥35 days), and use of transfusion were shown to be risk factors of postoperative complications following TKA.

Vascular Calcification in Patients Undergoing Total Knee Arthroplasty: Frequency and Effects on the Surgery.

BACKGROUD: This study aims to investigate the frequency of distal femoral and popliteal arterial calcification and to evaluate the intraoperative and postoperative effects of arterial calcification in patients undergoing total knee arthroplasty using a tourniquet. METHODS: The records of 5,438 patients who had undergone primary total knee arthroplasty between January 2003 and January 2017 were retrospectively reviewed. We examined the preoperative radiographs of the knee from all patients for calcifications of the femoral and popliteal arteries. Vascular calcification was identified on preoperative radiographs in 223 cases. Intraoperative and postoperative complications were investigated among these patients. Postoperative complications were analyzed from the time of surgery to the last follow-up (minimum 1-year follow-up). RESULTS: Vascular calcification of the arteries around the knee was found in 223 cases (4.1%). The mean patient age was 70.6 years in the non-calcification group and 73.8 years in the calcification group (p > 0.05). The calcification group was classified into medial, intimal, or mixed subgroups according to the morphology of calcification on preoperative radiographs. The medial type included 46 cases (20.6%); intimal type, 161 cases (72.2%); and mixed type, 16 cases (2.7%). There was no statistically significant difference in demographic and surgical data among the three groups. There were intraoperative complications in two cases in the medial type group, both of which involved tourniquet failure. There was also a postoperative complication in one case in the medial type group, which involved wound dehiscence at 2 weeks postoperatively. No other postoperative complications were identified during 1-year follow-up. CONCLUSIONS: Despite the presence of calcifications in the arteries around the knee, total knee arthroplasty (using a tourniquet) can be performed without serious complications.

Osteochondral Fracture of Posterior Aspect of Lateral Femoral Condyle After Lateral Patella Dislocation: A Case Report.

CASE: A healthy 15-year-old girl presented with osteochondral fracture at the posterior aspect of the lateral femoral condyle (LFC) associated with a right patellar dislocation after a noncontact injury. The patient remained asymptomatic 18 months after the arthroscopically assisted reduction and internal fixation of the osteochondral fracture using bioabsorbable pins and was able to eventually resume her usual activities of daily living. CONCLUSIONS: This is the first report of an osteochondral fracture at the posterior aspect of the LFC after an acute patellar dislocation, successfully treated with arthroscopically assisted reduction and internal fixation using bioabsorbable pins. This rare injury and unique mechanism of injury have been discussed.

Acute Gout Attack Immediately After Total Knee Arthroplasty: A Case Report.

CASE: We report a case of acute gouty arthritis-mimicking infection that occurred immediately after right total knee arthroplasty in a 73-year-old man. Repetitive laboratory tests showed acute inflammation and did not easily distinguish acute gout from bacterial infection. Surgical treatment was undertaken for diagnostic and therapeutic purposes. A large amount of chalky whitish crystals suggestive of acute gout was found in both knees without the suspicion of bacterial infection, and thorough irrigation and debridement were performed. CONCLUSIONS: Although conservative treatment is generally administered for acute gouty arthritis, early surgical intervention may ensure a good clinical result in a prosthetic joint.

Does Obesity Affect Clinical and Radiological Outcomes in Minimally Invasive Total Knee Arthroplasty? Minimum 5-Year Follow-up of Minimally Invasive TKA in Obese Patients.

BACKGROUND: The aim of this study was to evaluate the clinical and radiological outcomes of minimally invasive total knee arthroplasty (MIS-TKA) in obese patients. METHODS: We examined the records of 371 cases of MIS-TKA performed using the mini-midvastus approach from January 2006 to December 2006. According to body mass index (BMI), the cases were classified into group A (BMI < 25 kg/m2, 114 knees), group B (25 kg/m2 ≤ BMI < 30 kg/m2, 179 knees), and group C (BMI ≥ 30 kg/m2, 78 knees). Clinical outcomes were measured with the Hospital for Special Surgery Score and Knee Society Score. Radiological evaluation included measurements of knee alignment. RESULTS: MIS-TKA was performed on all patients. The skin incision size in group A, group B, and group C was 8.2 ± 0.8 cm, 8.3 ± 0.8 cm, and 8.5 ± 0.9 cm, respectively, and the operation time was 86.4 ± 10.4 minutes, 85.9 ± 11.3 minutes, and 89.0 ± 11.4 minutes, respectively, indicating no significant difference among the groups (p > 0.05). There was no difference in terms of the accuracy of the tibial implant alignment, with 97.6%, 95.2%, and 93.4% of each group showing 90° ± 3° varus angulation (p > 0.05). With respect to the accuracy of the femorotibial angle, 93.9%, 94.6%, and 90.2% of each group had 6° ± 3° valgus angulation, with group C demonstrating the lowest level of accuracy (p < 0.05). The preoperative range of motion and Knee Society Score of group C were less than those of groups A and B (p < 0.05), but there was no notable difference among groups at the postoperative 3-month and 1-year follow-ups (p > 0.05). CONCLUSIONS: MIS-TKA in obese patients showed satisfactory clinical and radiological results without significant difference in surgical results compared to nonobese patients.

Treatment of Recurrent Hemarthrosis after Total Knee Arthroplasty.

PURPOSE: The purpose of this study is to evaluate the incidence and treatment of recurrent hemarthrosis after total knee replacement (TKR). MATERIALS AND METHODS: Among a total of 5,510 patients who underwent TKR from March 2000 to October 2016, patients who had two or more bleeding 2 weeks after surgery were studied. Conservative treatments were performed for all cases with symptoms. In patients who did not respond to conservative treatment several times, embolization was performed. We retrospectively evaluated the postoperative bleeding time, bleeding frequency, treatment method, and outcome. RESULTS: Seventeen (0.3%) of the 5,510 patients developed recurrent hemarthrosis. Bleeding occurred at an average of 2 years 3 months after the operation. Joint aspiration was performed 3.5 times (range, 2 to 10 times) on average, and 14 cases (82.3%) were treated with conservative treatment. In 3 patients with severe bleeding and hemorrhage, embolization was performed. CONCLUSIONS: Recurrent hemarthrosis after TKR is a rare disease with a low incidence of 0.3% and usually could be treated by conservative treatment. If recurrences occur repeatedly, embolization through angiography or surgical treatment may be considered, but the results are not satisfactory and careful selection of treatment modalities is warranted.

Extramedullary Tibial Bone Cutting Using Medial Cortical Line in Total Knee Arthroplasty.

Purpose: This study aims to identify the effectiveness of the medial cortical line for attaining a more accurate tibial component alignment in proximal tibial resection using an extramedullary alignment rod. Materials and Methods: The study examined 100 cases of total knee arthroplasty performed from December 2013 to February 2014 in a retrospective manner. On a preoperative anteroposterior (AP) radiograph of the entire tibia, we identified the medial cortical line that runs parallel to the tibial anatomical axis and passes the medial tibial spine, and measured the point where the medial cortical line crosses between the medial malleolus and the lateral malleolus in the ankle joint. Results: The preoperative AP radiograph of the tibia showed the medial cortical line passing the point 40.4%±0.8% medial to the distance from the medial malleolus to the lateral malleolus including the skin thickness in the ankle joint. When the proximal tibial resection was performed with the extramedullary tibial cutting guide aligned with the medial cortical line, the tibial component angle averaged 0.7°±0.3° varus and the alignment accuracy of the tibial component within 0°±3° varus amounted to 97.0%. Conclusions: The use of the medial cortical line in proximal tibial resection with an extramedullary tibial cutting guide allowed for relatively accurate alignment of the tibial component.

Safety and efficacy of bi-annual intra-articular LBSA0103 injections in patients with knee osteoarthritis.

The objective of this study is to assess the safety and efficacy of repeated intra-articular injection of high molecular weight hyaluronic acid (LBSA0103) at a 26-week interval, in patients with osteoarthritis of the knee. The study was an open-label, single arm, multicentre prospective trial conducted in patients with symptomatic knee osteoarthritis. The intervention consisted of two intra-articular injections of LBSA0103, with the second injection performed 26 weeks after the first injection. The primary outcome was the incidence of adverse drug reactions related to each injection. Assessment of efficacy of repeated injections in terms of maintenance of pain relief was a secondary objective of this study. Of the 185 patients screened, 174 patients received the first injection and 153 patients received both injections of LBSA0103. Nine adverse drug reactions occurred in seven patients (4.02%) after the first injection, while only one adverse drug reaction occurred (0.65%) after the second injection. As a secondary outcome measure, the improvements in the efficacy parameters including total WOMAC score and weight-bearing pain were all significant at both week 13 and 39 compared to the baseline value (P < 0.001), and improvements after the second injection were consistent with those after the initial injection of LBSA0103 (between week 26 and week 39, P < 0.001). Repeated intra-articular injection of LBSA0103 at a 26-week interval is safe without increased risk of adverse drug reactions. Additionally, LBSA0103 is effective in reduction of osteoarthritis knee pain and in maintenance of pain reduction for a 39-week period when a second injection is administered.

Fracture Preventing Effects of Maxmarvil® Tablets (Alendronate 5 mg + Calcitriol 0.5 µg) in Patients with Osteoporosis.

BACKGROUND: The purpose of this prospective, open-label, observational study was to assess the fracture preventing effect of Maxmarvil® tablets (alendronate 5 mg + calcitriol 0.5 µg) in patients with osteoporosis and to evaluate the change in bone mineral density (BMD) at the minimum 1-year follow-up. METHODS: In this multicenter observational study, 691 patients with osteoporosis (aged 50 years or older) were treated with alendronate 5 mg + calcitriol 0.5 µg/day during their normal course of care. Patients were assessed at baseline and at 6 and 12 months. Baseline characteristics (including age, gender, concomitant disease, and baseline fractures) were evaluated. RESULTS: From among the 848 participants, 149 individuals were lost to follow-up at the time of the study and 8 people had died. The 691 participants (54 men and 637 women) finished the follow-up study and completed the questionnaire. The mean age of the participants was 71.5 years (range, 50-92 years; mean age, 72.3 years for men and 71.4 years for women). Osteoporotic fracture occurred in 19 patients (2.7%). BMD of the lumbar spine and hip was improved by 5% and 1.5% at the latest follow-up. At the latest follow-up, 24 patients (3.5%) complained of drug-related complications such as dyspepsia, constipation, and nausea. CONCLUSIONS: This prospective observational study demonstrated that alendronate 5 mg + calcitriol 0.5 µg/day had a preventive effect on osteoporotic fracture and it increased the BMD of the lumbar spine by 5% at the latest follow-up.

Efficacy and safety of single injection of cross-linked sodium hyaluronate vs. three injections of high molecular weight sodium hyaluronate for osteoarthritis of the knee: a double-blind, randomized, multi-center, non-inferiority study.

BACKGROUND: This randomized, double-blind, multi-center, non-inferiority trial was conducted to assess the efficacy and safety of a cross-linked hyaluronate (XLHA, single injection form) compared with a linear high molecular hyaluronate (HMWHA, thrice injection form) in patients with symptomatic knee osteoarthritis. METHODS: Two hundred eighty seven patients with osteoarthritis (Kellgren-Lawrence grade I to III) were randomized to each group. Three weekly injections were given in both groups but two times of saline injections preceded XLHA injection to maintain double-blindness. Primary endpoint was the change of weight-bearing pain (WBP) at 12 weeks after the last injection. Secondary endpoints included Western Ontario and McMaster Universities Osteoarthritis index; patient's and investigator's global assessment; pain at rest, at night, or in motion; OMERACT-OARSI responder rate; proportion of patients achieving at least 20 mm or 40% decrease in WBP; and rate of rescue medicine use and its total consumption. RESULTS: Mean changes of WBP at 12 weeks after the last injection were -33.3 mm with XLHA and -29.2 mm with HMWHA, proving non-inferiority of XLHA to HMWHA as the lower bound of 95% CI (-1.9 mm, 10.1 mm) was well above the predefined margin (-10 mm). There were no significant between-group differences in all secondary endpoints. Injection site pain was the most common adverse event and no remarkable safety issue was identified. CONCLUSIONS: This study demonstrated that a single injection of XLHA was non-inferior to three weekly injections of HMWHA in terms of WBP reduction, and supports XLHA as an effective and safe treatment for knee osteoarthritis. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT01510535 ). This trial was registered on January 6, 2012.

Radiologic Outcomes According to Varus Deformity in Minimally Invasive Surgery Total Knee Arthroplasty.

PURPOSE: To identify the accuracy of postoperative implant alignment in minimally invasive surgery total knee arthroplasty (MIS-TKA), based on the degree of varus deformity. MATERIALS AND METHODS: The research examined 627 cases of MIS-TKA from November 2005 to December 2007. The cases were categorized according to the preoperative degree of varus deformity in the knee joint in order to compare the postoperative alignment of the implant: less than 5° varus (Group 1, 351 cases), 5° to less than 10° varus (Group 2, 189 cases), 10° to less than 15° varus (Group 3, 59 cases), and 15° varus or more (Group 4, 28 cases). RESULTS: On average, the alignment of the tibial implant was 0.2±1.4°, 0.1±1.3°, 0.1±1.6°, and 0.3±1.7° varus, and the tibiofemoral alignment was 5.2±1.9degrees, 4.7±1.9°, 4.9±1.9°, and 5.1±2.0° valgus for Groups 1, 2, 3, and 4, respectively, in the preoperative stage, indicating no difference between the groups (p>0.05). With respect to the accuracy of the tibial implant alignment, 98.1%, 97.6%, 87.5%, and 86.7% of Groups 1, 2, 3, and 4, respectively, had 0±3° varus angulation, demonstrating a reduced level of accuracy in Groups 3 and 4 (p<0.0001). There was no difference in terms of tibiofemoral alignment, with 83.9%, 82.9%, 85.4%, and 86.7% of each group, respectively, showing 6±3° valgus angulation (p>0.05). CONCLUSION: Satisfactory component alignment was achieved in minimally invasive surgery in total knee arthroplasty, regardless of the degree of varus deformity.

Manipulation under Anesthesia for Stiffness after Total Knee Arthroplasty.

PURPOSE: This study evaluated the incidence of manipulation under anesthesia (MUA) for stiffness after total knee arthroplasty (TKA) and the degree of joint motion recovery after MUA. MATERIALS AND METHODS: A total of 4,449 TKAs (2,973 patients) were performed between March 2000 and August 2014. Cases that underwent MUA for stiffness after TKA were reviewed. TKAs were performed using the conventional procedure in 329 cases and using the minimally invasive procedure in 4,120 cases. The preoperative range of joint motion, timing of manipulation, diagnosis and the range of joint motion before and after MUA were retrospectively investigated. RESULTS: MUA was carried out in 22 cases (16 patients), resulting in the incidence of 0.5%. The incidence after the conventional procedure was 1.2% and 0.4% after the minimally invasive procedure. In the manipulated knees, the preoperative range of motion (ROM) was 102.5°±26.7°, and the preoperative diagnosis was osteoarthritis in 19 cases, rheumatoid arthritis in two, and infection sequela in one. MUA was performed 4.7±3.0 weeks after TKA. The average ROM was 64.5°±13.5° before manipulation. At an average of 64.3±41.3 months after manipulation, the ROM was recovered to 113.4°±31.2°, which was an additional 49.9° improvement in flexion. CONCLUSIONS: The satisfactory recovery of joint movement was achieved when MUA for stiffness was performed relatively early after TKA.

Minimum 5-year Follow-up Results of Minimally Invasive Total Knee Arthroplasty Using Mini-Keel Modular Tibial Implant.

PURPOSE: To evaluate the minimum 5-year mid-term clinical and radiological results of minimally invasive surgery total knee arthroplasty (MIS-TKA) using a mini-keel modular tibia component. MATERIALS AND METHODS: We retrospectively evaluated 254 patients (361 cases) who underwent MIS-TKA between 2005 and 2006. The latest clinical and radiological assessments were done in 168 cases that had been followed on an outpatient basis for more than 5 postoperative years. Clinical results were assessed using the Hospital for Special Surgery (HSS) score and Knee Society score. Radiological evaluation included measurements of knee alignment. RESULTS: The average postoperative knee range of motion and HSS score were 134.3°±12.4° and 92.7°±7.0°, respectively. The average postoperative femorotibial angle and tibial component alignment angle were 5.2°±1.7° valgus and 90.2°±1.6°, respectively. The average tibial component posterior inclination was 4.8°±2.1°. The percentage of cases with tibial component alignment angle of 90°±3° was 96.1%, and that with the femorotibial angle of 6°±3° valgus was 94.0%. Radiolucent lines were observed in 20 cases (12.0%): around the femur, tibia, and patella in 14 cases, 10 cases, and 1 case, respectively. However, they were less than 2 mm and non-progressive in all cases. The survival rate was 99.4% and there was no implant-related revision. CONCLUSIONS: MIS-TKA using a mini-keel modular tibial plate showed satisfactory results, a high survival rate, and excellent clinical and radiological results in the mid-term follow-up.

Congenital anomaly of the atlas misdiagnosed as posterior arch fracture of the atlas and atlantoaxial subluxation.

Partial or complete absence of the posterior arch of the atlas is a well-documented anomaly but a relatively rare condition. This condition is usually asymptomatic so most are diagnosed incidentally. There have been a few documented cases of congenital defects of the posterior arch of the atlas combined with atlantoaxial subluxation. We report a very rare case of congenital anomaly of the atlas combined with atlantoaxial subluxation, that can be misdiagnosed as posterior arch fracture.

Surgical outcomes of minimally invasive transforaminal lumbar interbody fusion for the treatment of spondylolisthesis and degenerative segmental instability.

STUDY DESIGN: This is a retrospective case study. PURPOSE: This study was designed to analyze the surgical outcomes of patients who underwent minimally invasive transforaminal lumbar interbody fusion (TLIF) for the treatment of spondylolisthesis and degenerative segmental instability. OVERVIEW OF LITERATURE: If the surgical outcomes of a procedure are evaluated together with multiple indications, it is not clear how the procedure helped each subgroup of patients. For the reason that some indications achieve better outcomes than the others, we performed a subgroup analysis using validated outcome measures to demonstrate the optimal indications and the treatment results of TLIF. METHODS: We conducted subgroup analyses by comparing the prospectively collecting data from the consecutive patients who underwent single-level minimally invasive TLIF for the treatment of the following 3 subgroups of indications: 23 cases of low-grade spondylolytic spondylolisthesis, 24 cases of degenerative spondylolisthesis, and 19 cases of degenerative segmental instability. RESULTS: The average duration of follow up was 36.1 ± 9.9 months (range, 24 to 63 months). The preoperative pain and disability scores were significantly improved at final postoperative follow-up in all the subgroups (all measurements: p < 0.0001). The 3 subgroups exhibited an equivalent improvement of the pain and disability scores at the final follow-up. The rates of radiographic solid fusion and complications were also similar among the 3 groups. CONCLUSIONS: Our data suggests that minimally invasive TLIF optimally and equivalently alleviates all of the associated symptoms and disabilities from low-grade spondylolisthesis and degenerative segmental instability. Furthermore, these patients seem to have optimal surgical indications for minimally invasive TLIF, while maintaining favorable surgical outcomes.