Comparison of Functional Recovery Between Unicompartmental and Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Comparisons of functional recovery between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) using performance-based tests are lacking. Therefore, this study aimed to compare 2-minute walk test (2MWT) and Timed Up-and-Go test (TUG) results between UKA and TKA for isolated medial knee osteoarthritis (OA). We hypothesized that UKA yields faster functional recovery than TKA as measured with the 2MWT and TUG. METHODS: We conducted a randomized controlled trial comparing medial UKA and TKA in patients with isolated medial knee OA. A total of 110 patients were enrolled; after 11 exclusions, 99 patients (50 UKA, 49 TKA) were included in the final analysis. The patients were tested using the 2MWT and TUG preoperatively and at 6 weeks, 3 and 6 months, and 1 and 2 years postoperatively. Patient-reported outcome measures (PROMs) were also evaluated. The mean 2MWT, TUG, and PROM results were compared between groups at each time point. RESULTS: The mean 2MWT distance after UKA was significantly longer than that after TKA at 6 weeks (96.5 ± 22.6 m for UKA compared with 81.1 ± 19.1 m for TKA; difference, 18 m [95% confidence interval (CI),10.4 to 25.6 m]; p < 0.001), 3 months (102.1± 24.4 compared with 87.5 ± 22.3 m; difference, 14.7 m [95% CI, 5.4 to 24.0 m]; p = 0.002), and 6 months (102.8 ± 16.2 compared with 89.6 ± 15.3 m; difference, 13.2 m [95% CI, 6.9 to 19.5 m]; p < 0.001). The values at 1 and 2 years were similar after UKA and TKA. The mean TUG after UKA was also significantly shorter than that after TKA at 6 weeks and 3 months. The mean PROMs were similar after both treatments, with the exception of the Oxford Knee Score and subscales of the Knee injury and Osteoarthritis Outcome Score at 6 weeks and 3 months postoperatively. CONCLUSIONS: The 2MWT indicated that UKA for isolated medial knee OA enabled faster recovery than TKA did at 6 weeks to 6 months, and earlier recovery was also seen with the TUG at 6 weeks to 3 months. The 2MWT and TUG results after UKA and TKA were similar to one another at 1 and 2 years. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Novel molded antibiotic cement spacer: is it better than handmade cement spacer for treatment of chronically infected total hip arthroplasty?

PURPOSE: A handmade antibiotic cement spacer is the easiest method for producing a spacer for treating chronic periprosthetic joint infection after total hip arthroplasty (THA). However, a molded spacer offers more head and stem sizes to match the patient's anatomy. The purpose of this study was to evaluate the functional outcomes and complications between handmade and molded spacers. METHODS: This retrospective case note study compared the functional results, re-infection rate, and spacer related complications after the first stage and second stage exchange arthroplasty between a handmade spacer and a novel molded cement spacer with three sizes of femoral head (45, 50, and 55 mm) and two stem sizes (small, large). RESULTS: Fifteen chronically infected THA patients were identified: nine handmade and 6 molded spacers. The modified Harris Hip Score showed no inter-group differences pre-operatively and after first stage and second stage exchange arthroplasty. The erythrocyte sedimentary rates and C-reactive protein concentrations were similar at all time points, and there were no re-infections. The molded spacer group showed lower post-operative complications with no spacer fractures, spacer dislocations, and periprosthetic fractures, but two had spacer subsidence. The handmade spacer had two spacer fractures, one spacer dislocation with a periprosthetic femoral fracture, and four cases of spacer subsidence. CONCLUSION: Our small study showed no differences in functional outcomes and no re-infections in either group, but higher spacer-related complications occurred in the handmade spacer group. These data suggest molded spacers are better than handmade spacers.

Does Nefopam Provide Analgesic Effect and Reduce Morphine Consumption After Primary Total Knee Arthroplasty? A Prospective, Double-Blind, Randomized Controlled Trial.

BACKGROUND: One of the most undesirable results after total knee arthroplasty (TKA) is severe immediate postoperative pain, resulting in patient dissatisfaction. We aimed to evaluate nefopam's analgesic efficacy after primary TKA along with related outcomes, including morphine consumption and adverse events. METHODS: We conducted a double-blind, randomized controlled trial of patients undergoing unilateral primary TKA, comparing 24 hours of 80 mg of continuous intravenous nefopam to placebo infusion. A 100-mm Visual Analog Scale (VAS) for pain-at-rest and in-motion ≤48 hours was the primary outcome measure. Secondary outcomes were morphine and antiemetic consumption, adverse events, and functional outcomes: time-to-walk, timed up-and-go test, postoperative knee range of motion at 24 and 48 hours, time-to-discharge, and patient satisfaction scores. RESULTS: Patients in the nefopam group had significantly lower VAS at rest 6 hours postop (20.3 ± 27.3 vs 35 ± 24.3, P = .01). Other timepoints and in-motion VAS did not significantly differ. Total morphine consumption (0-48 hours) was 37% less, significantly lower, in the nefopam group (5.3 ± 4.5 vs 8.4 ± 7.5 mg, P = .03). Antiemetic consumption was also 61% lower in the nefopam group but not statistically significant (0.8 ± 2.3 vs 2.0 ± 3.8 mg, P = .08). There were no variations in adverse events, functional outcomes, and satisfaction scores between groups. CONCLUSION: Continuous nefopam administration as part of multimodal analgesia for 24 hours post-TKA produced a significant analgesic effect but only within the first 6 hours. However, there was a notable reduction in morphine use 48 hours postop. Nefopam is a useful agent for contemporary pain control after TKA. LEVEL OF EVIDENCE: Therapeutic Level I.

Efficacy and Systemic Absorption of Peri-articular Versus Intra-articular Administration of Tranexamic Acid in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

BACKGROUND: Tranexamic acid (TXA) is widely accepted as an effective method for reducing blood loss after total knee arthroplasty (TKA). As different routes of local TXA administration have been proposed to minimize systemic complications, we aimed to investigate the effectiveness and systemic absorption of peri-articular (PA) and intra-articular (IA) administration of TXA after primary TKA. METHODS: In a randomized controlled trial of patients scheduled for unilateral primary TKA, 108 were assigned to receive PA-TXA (15 mg/kg), IA-TXA (2 g), or no TXA injection. We assessed total blood loss, blood transfusion rate, and hemoglobin level changes 48 hours after surgery. Postoperative serum TXA levels, complications, and clinical symptoms of venous thromboembolism events were also evaluated. RESULTS: Total blood loss, hemoglobin level decreases, and blood transfusion rates in both TXA groups were significantly lower than those in the control group (P < .05), without significant differences between PA and IA groups 48 hours after surgery. Serum TXA levels in the IA group were significantly higher than those in the PA cohort at 2 hours (28.2 mg/L vs 15.6 mg/L, P < .01) and 24 hours (4.4 mg/L vs 1.7 mg/L, P < .01) postoperatively. No wound complications were found in both TXA groups, but 14% of the control group developed subcutaneous ecchymoses. No evidence of venous thromboembolism events was reported. CONCLUSIONS: PA-TXA is an excellent alternative route of local TXA injection to decrease postoperative blood loss after TKA. PA-TXA demonstrated lower levels of postoperative serum TXA, which may be beneficial for high-risk patients.

Modified Kerboul Angle Predicts Outcome of Core Decompression With or Without Additional Cell Therapy.

BACKGROUND: Core decompression is the most common procedure for early-stage osteonecrosis of the femoral head (ONFH). This study investigated outcomes of core decompression with/without bone marrow aspirate concentrate (BMAC), based on the Kerboul combined necrotic angles using magnetic resonance imaging. METHODS: We reviewed 66 patients (83 hips) with early ONFH, Association Research Circulation Osseous stages I-IIIa, who underwent core decompression alone (26 patients, 33 hips) or in combination with BMAC (40 patients, 50 hips). Survival rate and progressive collapse were analyzed using the Kaplan-Meier method, and conversion to total hip arthroplasty (THA) was evaluated. Subgroup analyses based on the modified Kerboul angle were performed: grade I (<200°), grade II (200°-249°), grade III (250°-299°), and grade IV (≥300°). RESULTS: Mean follow-up was 36 ± 23 months. Femoral head collapse with BMAC (16 hips, 32%) was significantly lower than without BMAC (19 hips, 58%, P = .019). Conversion THA was significantly lower with BMAC (28%) than without (58%, P = .007). Survival rates among groups showed significant differences (P = .017). In grade I, 0/12 hips with BMAC collapsed while 3/9 (33%) without BMAC collapsed (P = .063); in grade II, 2/16 hips (12%) with BMAC collapsed while 7/13 (54%) without BMAC collapsed (P = .023). There was no significant difference in collapse with (64%) or without (82%) BMAC in grade III-IV hips (P = .256). CONCLUSION: Core decompression with/without BMAC had a high failure rate, by increasing disease progression and the necessity for THA, for combined necrotic angles >250°. In our study, addition of BMAC had more reliable outcomes than isolated core decompression for precollapse ONFH if the combined necrotic angles were <250°.

Effect of Different Tourniquet Pressure on Postoperative Pain and Complications After Total Knee Arthroplasty: A Prospective, Randomized Controlled Trial.

BACKGROUND: Tourniquet pressure inflation is commonly selected between 100 and 150 mm Hg above the systolic blood pressure (SBP). Given the lack of evidence to support a given inflation pressure, our study aimed to ascertain the lowest tourniquet pressure that facilitated total knee arthroplasty (TKA) and resulted in the least postoperative pain and complications. METHODS: In a double-blind, randomized controlled trial of patients scheduled for unilateral primary TKA, 150 were assigned to use tourniquet pressures of SBP + 75 mm Hg (group I), SBP + 100 mm Hg (group II), and SBP + 150 mm Hg (group III). The quality of the bloodless field, total blood loss, and limb swelling were determined perioperatively. Clinical outcomes were evaluated by visual analog scale for pain at thigh and surgical site, serum creatinine phosphokinase levels, wound complications, range of motion, and Knee Society Score. RESULTS: Visual analog scale for pain at thigh and surgical site were lowest in group I (P < .01) and highest in group III (P < .01). However, the quality of bloodless field at the tibial cutting surface was significantly better in group III compared to group I/II but not at the femoral cutting surface. The total blood loss and limb swelling showed no difference among 3 groups. Postoperative serum creatinine phosphokinase levels at 24 and 48 hours and wound complications in group III were significantly higher than group I (P < .01) and group II (P < .01). Nevertheless, postoperative knee range of motion and Knee Society Score were not significantly different among 3 groups. CONCLUSION: Post TKA, the lowest tourniquet pressure was associated with significantly less postoperative tourniquet and surgical site pain, muscle damage, and wound complications.

The effect of immediate post-operative knee range of motion photographs on post-operative range of motion after total knee arthroplasty : An assessor-blinded randomized controlled clinical trial in sixty patients.

PURPOSE: We attempted to determine the effect of immediate post-operative knee range of motion (ROM) photographs on improving ROM after total knee arthroplasty (TKA). METHODS: Sixty patients, scheduled for unilateral primary TKA, were randomized into two groups. The photo group (n = 30) were immediately shown post-TKA knee ROM photographs as motivation for rehabilitation. The non-photo group (n = 30) received identical post-operative pain control and rehabilitation programs. Post-operative knee ROM and Knee Society Scores (KSS) at day three, six weeks, three months, six months, one year, and two years were evaluated. Outcome assessors were blinded to the groups during the study. RESULTS: Patients in the photo group had better knee flexion on day three (99.9° ± 15.3°, 95% confidence interval (CI) 94.1-105.7° vs. 92.3° ± 11.4°, 95% CI 87.9-96.8°; p = 0.038) and at six weeks (120.9° ± 13.4°, 95% CI 115.7-126.0° vs. 112.5° ± 13.6°, 95% CI 107.2-117.8°; p = 0.023); however, there were no differences in range of flexion beyond six weeks post-operatively. Knee extension did not significantly differ throughout. Clinical KSS was significantly higher in the photo group at six weeks (90.7° ± 6.2° vs. 86.6° ± 6.4°, p = 0.017). Functional KSS showed no differences between groups during follow-up. CONCLUSION: Showing knee ROM photographs seemed to result in significant improvement of knee flexion and clinical KSS in the first 6 weeks post-TKA and may be recommended as part of post-TKA rehabilitation.

Outcomes of Cemented Total Knee Arthroplasty for Secondary Osteonecrosis of the Knee.

BACKGROUND: Secondary osteonecrosis of the knee (SOK) generally occurs in relatively young patients; at advanced stages of SOK, the only viable surgical option is total knee arthroplasty (TKA). We conducted a retrospective study to investigate implant survivorship, clinical and radiographic outcomes, and complications of contemporary cemented bicompartmental TKA with/without patellar resurfacing for SOK. METHODS: Thirty-eight cemented TKAs in 27 patients with atraumatic SOK, mean age 43 years (17 to 65), were retrospectively reviewed. Seventy-four percent had a history of corticosteroid use, and 18% had a history of alcohol abuse. Patellar osteonecrosis was coincidentally found in six knees (16%), and all were asymptomatic without joint collapse. The mean followup was 7 years (2 to 12). Knee Society Score (KSS) and radiographic outcomes were evaluated at 6 weeks, 1 year, then every 2 to 3 years. RESULTS: Ninety-two percent had implant survivorship free from revision with significant improvement in KSS. Causes of revision included aseptic tibial loosening (one), deep infection (one), and instability with patellofemoral issues (one). Four of six cases also with patellar osteonecrosis received resurfacing, including one with periprosthetic patellar fracture after minor trauma, with satisfactory clinical results after conservative treatment. None of the unrevised knees had progressive radiolucent lines or evidence of loosening. An unresurfaced patella, use of a stem extension or a varus-valgus constrained prosthesis constituted 18%, 8% and 3%, respectively. CONCLUSION: Cemented TKAs with selective stem extension in patients with SOK had satisfactory implant survivorship and reliable outcomes. Secondary osteonecrosis of the patella should be carefully evaluated prior to operation.

Initial Presentation and Progression of Secondary Osteonecrosis of the Knee.

BACKGROUND: Early detection and intervention are critical to maintaining the native articular cartilage before collapse in secondary osteonecrosis of the knee (SOK). We conducted a retrospective study documenting the initial stage of presentation and the progression of SOK. METHODS: Our database was reviewed for patients younger than 65 years of age diagnosed with atraumatic SOK between 2002 and 2018. Demographic data, plain radiographs as well as MRI at initial evaluation, and initial treatment were classified and analyzed. RESULTS: One hundred four patients with 164 knees were identified. Mean age was 39 ± 16 years. Females (64%) with bilateral disease (58%) predominated. Seventy-five percent of patients had a history of corticosteroid use, of which 41% were diagnosed with hematologic malignancy and lupus. Fifteen percent of patients had a history of ethanol abuse. At initial presentation, 55% of patients were diagnosed with Ficat-Arlet stage I/II, while 45% were diagnosed with Ficat-Arlet stage III/IV. We found a significant difference in the mean age of patients at early stage of SOK with corticosteroid use (31 ± 12 years of age) when compared to ethanol use (43 ± 13 years of age, P = .02). Treatments included observation (57%), joint preservation surgery (20%), and total knee arthroplasty (23%). CONCLUSION: Nearly half of patients presented at late stage compromising the potential for joint preservation. The difference in age of referral by over a decade, based on etiology of SOK, suggests a strong provider-based referral or screening bias may be present. Hence, a multidisciplinary approach to earlier detection and referral may be a more effective strategy for preventing the progression of SOK.

Diagnosis of Osteonecrosis of the Femoral Head: Too Little, Too Late, and Independent of Etiology.

BACKGROUND: Joint preservation is more effective in early-stage osteonecrosis of the femoral head (ONFH); thus, prompt diagnosis when the femoral head is still salvageable is important. We report a 20-year retrospective study that summarizes age at presentation, etiology, and Association Research Circulation Osseous stage at diagnosis. METHODS: Our database was reviewed to identify patients younger than 65 years of age who were diagnosed with atraumatic ONFH between 1998 and 2018. Demographic characteristics of patients were evaluated and categorized into different subgroups. RESULTS: Four hundred thirteen patients were identified. At initial presentation, 23% were diagnosed with early-stage ONFH, while 77% were diagnosed with late-stage ONFH. Forty-nine percent had a history of corticosteroid use, of which 13% were diagnosed with hematologic malignancy and 8% were diagnosed with lupus. Ethanol abuse, idiopathic, sickle cell disease, and human immunodeficiency virus were present in 11%, 30%, 3%, and 3%, respectively. The mean age of patients with corticosteroid use (40 ± 14 years) was significantly younger than ethanol use (46 ± 11 years, P = .014) and idiopathic causes (48 ± 11 years, P < .001), but significantly older than sickle cell disease (32 ± 11 years, P = .031). There was no difference in the age of presentation for early-stage and late-stage ONFH by etiology. CONCLUSION: Nearly 80% of the patients presented with late-stage ONFH. Hence, we have a narrow window of opportunity for hip preservation surgery before femoral head collapse. A multidisciplinary approach to improve screening awareness for early detection by focusing on the etiologic identification and patient education might reduce the incidence of hip arthroplasty in young patients.

A new method for measurement of the size of subacromial spurs of the shoulder by cassette tilt view.

OBJECTIVE: Subacromial impingement syndrome is one of the most common causes of pain in the shoulder. To this date, there is no specific radiographic view that can be used to evaluate the size of a subacromial spur. This study aims to examine a cassette tilt view can be used to evaluate the size of a subacromial spur. METHODS: A cross-sectional study was conducted between the time period of January 1, 2016, and December 31, 2016. Forty-three consecutive patients that had planned treatment of arthroscopic subacromial decompression (SAD) participated in this study. Rockwood view and cassette tilt view (caudal tilt 30  with beam and cassette) X-rays were done in all these patients. The measurements of the spur sizes were calculated from both views and were compared to the spur sizes measured intraoperatively. RESULT: The size of the spurs from intraoperative measurement was not significantly different from the spur size measured using the cassette tilt view with a mean difference of 0.54 (95% confidence interval (CI): - 0.58, 1.65), but the intraoperative measurement was significantly different from the Rockwood view spur measurement, with a mean difference of 2.84 (95% CI: 1.56, 4.11). Average proportions of the size of the spur from the cassette tilt and Rockwood view compared to that from intraoperative measurements were 1.09 and 1.55, respectively. CONCLUSION: The cassette tilt view is a simple method of measurement of the size of subacromial spurs, with good inter- and intra-observer reliabilities and good validity. This can be useful clinically when setting the patient position and portals to evaluate the size of the spur when planning SAD. LEVEL OF EVIDENCE: This is level III.

Outcomes of mobile bearing unicompartmental knee arthroplasty in medial osteoarthritis knee with and without preoperative genu recurvatum.

AIM: To compare clinical outcomes of patients with and without preoperative genu recurvatum (GR) following mobile bearing unicompartmental knee arthroplasty (UKA). METHODS: We prospectively followed 176 patients for at least 24 mo who had been treated by unilateral, minimally invasive, Oxford UKA. Patients with medial osteoarthritis (OA) knee and preoperative GR (Group I) accounted for 18% (n = 32) and patients without preoperative GR (Group II) accounted for the remaining 82% (n = 144). Knee score, pain scores, and functional scores were assessed for each patient and compared between the two groups. The incidence of postoperative GR and the postoperative hyperextension angles also were recorded and analyzed. RESULTS: The pain score, knee score and functional score were not significantly different between the two groups. Similarly, the incidence of postoperative GR and the measured hyperextension angles were not significantly different between the two groups. The incidence of postoperative GR was 1/32 (3.12%) in Group I and 1/144 (0.69%) in Group II (P = 0.34). The mean postoperative hyperextension angles were 2.40° ± 2.19° (range: 1°-7°) for Group I and 1.57° ± 3.51° (range: 1°-6°) for Group II (P = 0.65). CONCLUSION: Medial OA of the knee and concomitant GR is not a contraindication for the mobile bearing UKA.

Risk factors and outcomes in asymmetrical femoral component size for posterior referencing bilateral total knee arthroplasty: a matched pair analysis.

BACKGROUND: Theoretically, potential errors in femoral component (FC) sizing can affect postoperative functional outcomes after total knee arthroplasty (TKA), including range of motion (ROM), anterior knee pain, and flexion stability. Incidences of asymmetrical femoral components (AFC) in bilateral TKA have been reported; however; there is a lack of data on exactly why AFC size selection may differ in patients who have had posterior referencing system bilateral TKA. Therefore, this study was conducted to determine risk factors of AFC size selection in patients specifically undergoing posterior referencing bilateral TKA and to compare clinical outcomes between those with AFC or symmetrical femoral component (SFC) sizes. METHODS: We conducted a retrospective matched-pair study comparing thirty-four patients who had undergone simultaneous and staged bilateral TKA using AFC size (Group I) and thirty-five patients with SFC size (Group II). Patients were matched according to gender, body mass index, prosthesis type, and operative technique. Preoperative radiographic morphology of both distal femurs including anteroposterior/mediolateral diameters, anterior-posterior femoral offset, and postoperative radiographic data of FC comprising flexion and valgus angle were recorded. The postoperative functional outcomes including ROM, anterior knee pain, knee society score, and functional score at 6 weeks, 3, 6, 12 and 24 months were compared. RESULTS: There were no differences in morphology between left and right distal femurs from preoperative radiographic data in both groups. The postoperative radiograph showed a significantly greater FC flexion angle difference in Group I vs. Group II (2.18° ± 1.29° and 1.36° ± 1.08° P = 0.007), while the other parameters were the same. The postoperative clinical outcomes displayed no distinction between groups. CONCLUSION: The factor primarily associated with AFC size selection in bilateral TKAs is the difference in FC flexion angle but not the morphological diversity between sides. The postoperative functional outcomes were not inferior in AFC patients in comparison with SFC patients.

Is Regular Knee Radiograph Reliable Enough to Assess the Knee Prosthesis Position?

BACKGROUND: Proper knee alignment and prosthesis position may theoretically provide better surgical results and increase longevity of total knee arthroplasty. The 3-feet standing long radiograph (LR) is the gold standard for assessment of these parameters. However, the conventional standing regular knee radiograph (RR) is still being used because of convenience and lower cost. We conducted a study to investigate the accuracy of RR compared to LR in assessing the coronal plane prosthesis position. METHODS: We conducted a retrospective cross-sectional study in 100 knee radiographs in 88 patients with knee prostheses. The picture archiving and communications system was used to produce digitized radiographs and perform the angle measurements. LR images were cropped to the same size as the RRs to eradicate rotation error. The femoral component angle (FCA), tibial component angle (TCA), and tibiofemoral angle (TFA) were measured and analyzed by Student t-test. Pearson's correlation coefficient was used to assess interobserver and intraobserver reliability. RESULTS: The RR measurements resulted in a mean increment of 1.3° (95% confidence interval [CI], 0.9°-1.6°; P < .001) for FCA and 1.4° (95% CI, 1.0°-1.9°; P < .001) for TFA compared to LR. The TCAs were similar between 2 techniques (0.2° mean difference; 95% CI, 0°-0.4°; P = .11). RR provided very strong intraobserver reproducibility but only strong interobserver reliability for FCA and TCA while LR provided very strong correlation for all angles. CONCLUSION: RR overestimation of FCA and TFAs in a valgus alignment was minimal, suggesting RR could be an acceptable alternative to LR.

Effectiveness Testing of Combined Innovative Pressurized Carbon Dioxide Lavage and Pulsatile Normal Saline Irrigation to Enhance Bone Cement Penetration in Total Knee Replacement: A Cadaveric Study.

Background: The cementing technique in total knee arthroplasty (TKA) is essential for a successful outcome. Previous studies have shown that deeper cement penetration results in greater tensile and shear strength between the bony part and the prosthetic parts. Objective: Objective: To investigate the effectiveness of combined innovative pressurized carbon dioxide lavage and pulsatile normal saline irrigation for enhancing cement penetration into cancellous bone, as compared with standard pulsatile normal irrigation alone. Material and Method: An intra-individual comparative cadaveric study was conducted at the Department of Orthopaedic Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University in April 2015. Ten fresh cadavers underwent TKA via the medial parapatellar approach. The proximal tibia was cut perpendicular to its anatomical axis at a point nine millimeters inferior to the lateral plateau. After randomization of knees, the proximal tibia of one side was prepared with pulsatile normal saline irrigation followed by innovative pressurized carbon dioxide lavage. The contralateral side was then prepared using standard pulsatile normal saline irrigation alone. After completing bilateral cemented TKA, the tibial prostheses were removed from both knees. The proximal tibia was then cut on three planes. The posterior coronal plane cut, the medial sagittal oblique plane cut, and the lateral sagittal oblique plane cut facilitated visualization and measurement of the depth of cement penetration into the posterior, middle, and lateral columns, respectively. A bone sample from each column was measured by digital vernier caliper to evaluate bone cement penetration. Results: Combined innovative pressurized carbon dioxide lavage and pulsatile normal saline irrigation produced significantly deeper cement penetration into cancellous bone, as compared with pulsatile normal irrigation alone (1.90±0.39 mm vs. 1.21±0.21 mm, p = 0.04). Conclusion: Combined innovative pressurized carbon dioxide lavage and pulsatile normal saline irrigation produced significantly deeper bone cement penetration than pulsatile normal saline irrigation alone.

Vertical pelvic ring displacement in pelvic ring injury: Measurements in pelvic outlet radiograph and in cadavers.

BACKGROUND: Vertical pelvic ring displacement (VPRD) is a serious injury and needs assessment. Pelvic outlet radiographs are routinely taken. However, relationship of radiographic and actual VPRD is still in question. Thus, measurement of VPRD from pelvic radiographs was studied. MATERIALS AND METHODS: 2 dry pelvic bones and 1 sacrum from same cadaver was reconstructed to be the pelvic ring. Five specimens were enrolled. 10, 20 and 30 mm vertical displacement of right pelvic bone was performed at levels of sacroiliac joint and pubic symphysis for representing right VPRD. Then, the pelvis was set sacral inclination at 60° from X-ray table for outlet and anteroposterior pelvic radiographs. Right VPRD was measured by referring to superior most pelvic articular surface of both sacroiliac joints and sacral long axis. Radiographic VPRD and actual displacement were analyzed by Pearson correlation coefficient at more than 0.90 for the strong correlation and strongly significant simple regression analysis was set at P < 0.01. RESULTS: Radiographic VPRD from outlet and anteroposterior pelvic views at 10 mm actual displacement were 20.12 ± 1.98 and 4.08 ± 3.76 mm, at 20 mm were 40.31 ± 1.97 and 9.94 ± 7.27 mm and at 30 mm were 58.56 ± 2.53 and 11.29 ± 2.89 mm. Statistical analyses showed that radiographic VPRD from pelvic outlet view is 1.95 times of actual displacement with strong correlation at 0.992 coefficient and strongly significant regression analysis (P < 0.001) with 0.984 of R (2) value. Whereas, the measurement from anteroposterior pelvic radiograph was not strongly significant. CONCLUSION: Pelvic outlet radiograph provides efficient measurement of VPRD with 2 times of actual displacement.

Sterility verification of innovative pressurized carbon dioxide lavage for bone surface preparation in cemented knee arthroplasty.

OBJECTIVE: To verify sterility of innovative pressurized carbon dioxide (CO) lavage for bone surface preparation in cemented knee arthroplasty. MATERIAL AND METHOD: Twenty-five 500 L. air samples from the innovative pressurized CO, lavage were laboratory tested to verify the presence or absence of either bacteria or fungi in microbial air samplings taken in a biological safety cabinet. CO2 gas was delivered though a pressure regulator, a sterile delivery tube, a hand piece, and a microbial air filter with a pressure level of 50 psi, according to the medical standard. Contamination samples for bacteria and fungi were taken by using Tryptic Soy Agar and SabouraudAgar as the culture media and were then analyzed at 48 hours and 10 days, respectively. RESULTS: Twenty-five samples of microbial culture showed no bacterial or fungal growth on either Tryptic Soy Agar or Sabouraud Agar CONCLUSION: The sterility of the innovative pressurized carbon dioxide lavage was confirmed by laboratory test results and was approved for application for bone surface preparation in cemented total knee arthroplasty.