Comparison of screw-home movement between patients with knee osteoarthritis and normal adults.

BACKGROUND: Tibial rotation accompanying sagittal movement contains the phenomenon of screw-home movement (SHM) of the knee, which plays an important role in knee stability during extension. OBJECTIVE: This study aimed to investigate the change of SHM in patients with knee osteoarthritis (OA). METHODS: Thirty-one sex-matched patients with knee OA and 31 normal subjects were recruited. The total tibial rotation was obtained during knee sagittal movement (extension and flexion) using an inertial measurement unit. The acquired angle of tibial rotation was divided into eight periods. The total tibial rotation and the variation of each period were compared between the OA and control groups. The difference in tibial rotation according to Kellgren-Lawrence (KL) grade was compared. RESULTS: The total tibial rotation of the OA group decreased compared with the control group during knee extension and flexion (P< 0.001). Variations of tibial rotation were significantly different between groups in all periods (P< 0.001) except for knee extension at 70∘ to 45∘ (P= 0.081). There was no significant difference in tibial rotations among the KA grades of OA patients. CONCLUSION: We found a reduction in the total tibial rotation and loss of the SHM in the unloaded OA knee. It could be predicted that reduced SHM appeared early in knee OA.

Factors affecting stability after medial opening wedge high tibial osteotomy using locking plate: A cadaveric study.

OBJECTIVES: To investigate the effect of screw length, lateral hinge fracture, and gap filling on stability after medial opening wedge high tibial osteotomy (MOW HTO) using a locking plate. METHODS: Forty tibiae from fresh-frozen cadavers were randomly allocated into five groups. Group A was bicortically fixated, while Group B and Group C were unicortically fixated: 90% and 55% of drilled tunnel length, respectively. Group D was fixated using 90% length screws with a fractured lateral hinge. Group E was fixated using 90% length screws with gap filling using a bone substitute. Operated tibiae were tested under axial compressive load using a material testing machine. The medial gap changes under the serial axial load of 100-600 N and ultimate failure load were measured. RESULTS: Group D showed the biggest medial gap change and lowest failure load, while Group E presented the smallest gap change and highest failure load. The medial gap changes tended to increase with shorter screw length, but the difference was not significant between Groups A, B, and C. Group C and Group D showed greater medial gap change and lower failure load compared with Group E, while not differing from Group A and Group B. CONCLUSIONS: Unicortical fixation in proximal screw holes of a locking plate was not inferior to bicortical fixation regarding axial stability in MOW HTO, although proximal screws that are too short should be avoided. Lateral hinge fracture decreased, while gap filling with bone substitute increased axial stability.

Early Clinical Outcomes of a New Posteriorly Stabilized Total Knee Arthroplasty Prosthesis: Comparisons with Two Established Prostheses.

Purpose: We sought to determine whether early clinical performance of new posterior stabilized (PS) knee system, the Vega-PS (Aesculap), is better than that of two established total knee arthroplasty (TKA) prostheses, the E.motion-PS (Aesculap) and the Genesis II (Smith & Nephew) in terms of functional outcomes, patient satisfaction, and incidence of adverse events. Materials and Methods: We compared the clinical outcomes of 206 consecutive TKAs using Vega-PS with those of 205 TKAs using E.motion-PS and 216 TKAs using Genesis II at 2 years of follow-up. Results: Overall, the knees with the Vega-PS had better functional outcome scores than the knees with the E.motion-PS, but had similar outcome scores to the knees with the Genesis II, as evident from the American Knee Society knee score (94.2 vs. 92.5 vs. 93.2), Western Ontario McMaster Universities Osteoarthritis (WOMAC) stiffness index (1.8 vs. 2.3 vs. 2.0), WOMAC function index (11.8 vs. 16.8 vs. 18.5), Short Form 36 (SF-36) physical component summary score (41.9 vs. 39.3 vs. 41.6), and SF-36 mental component summary score (50.0 vs. 45.8 vs. 46.9). Patient satisfaction was higher in the Vega-PS and Genesis II groups than the E.motion-PS group. No notable group differences were found in terms of the incidence of adverse events. Conclusions: The Vega-PS, a newly developed PS fixed bearing prosthesis, had comparable or superior clinical performance in comparison with the two established fixed or mobile bearing PS prostheses.

A new femoral fixation device for anterior cruciate ligament reconstruction using the outside-in technique and hamstring tendon graft: A comparison between two devices in cadaveric human knee models.

BACKGROUND: A new device (T-anchor) was developed for ACL reconstruction and is implanted via the outside-in technique using hamstring grafts. The purpose of this study was to compare the T-anchor with the EndoButton Direct. METHODS: This study was conducted on 30 cadaveric knees (15 matched pairs). There were two groups of 15 each in the T-anchor and EndoButton Direct groups. After the harvest of grafts, fixation site profile and graft length were measured by loading the grafts onto both devices. They were then tested on a universal testing machine to assess elongation after cyclic loading, load to failure, ultimate load, and mode of failure. RESULTS: The fixation site profile was lower in the T-anchor group than in the EndoButton Direct group (2.3±0.4mm vs. 4.7±1.0mm, P<0.001). The length of the graft-device complex of the T-anchor specimens was longer than that of the EndoButton Direct specimens (125.0±8.9mm vs. 115.0±8.7mm, P<0.001). The mean cyclic elongation was lower for the T-anchor group when compared with the EndoButton Direct group (2.4±0.6mm vs. 3.9±2.6mm, P=0.015). There was no statistically significant difference in ultimate load and load to failure between the T-anchor and EndoButton Direct groups. For mode of failure, the T-anchor fared better (P=0.013) with all failures attributed to specimens. CONCLUSIONS: In this cadaveric study, the new device, T-anchor, performed better than the EndoButton Direct with respect to the above-mentioned study parameters except for ultimate load and load to failure.

What is the Ideal Route of Administration of Tranexamic Acid in TKA? A Randomized Controlled Trial.

BACKGROUND: TKA commonly involves substantial blood loss and tranexamic acid has been used to reduce blood loss after TKA. Numerous clinical trials have documented the efficacy and safety of intravenous (IV) or intraarticular (IA) use of tranexamic acid. Combined administration of tranexamic acid also has been suggested; however, there is no consensus regarding the ideal route of tranexamic acid administration. QUESTIONS/PURPOSES: (1) To compare the efficacy of tranexamic acid in terms of total blood loss and the allogeneic transfusion rate among three routes of administration: IV alone, IA alone, and combined IV and IA. (2) To compare these regimens in terms of venous thromboembolism (VTE) and the frequency of wound complications. METHODS: In total, 376 patients undergoing TKA between March 2014 and March 2015 were randomized to four groups by the route of tranexamic acid administration: IV only, IA only, low-dose combined (IV + IA injection of 1 g), and high-dose combined (IV + IA injection of 2 g). The calculated total blood loss, allogeneic transfusion rate, decrease in hemoglobin, the frequency of symptomatic deep vein thrombosis and pulmonary embolism, wound complications, and periprosthetic joint infection were compared among the groups. Total blood loss was calculated using estimated total body blood volume and hemoglobin loss. The decision regarding when to transfuse was determined based on preset criteria. RESULTS: The high- and low-dose combined groups and the IA-only group had lower total blood loss (564 ± 242 mL, 642 ± 242 mL, and 633 ± 205 mL, respectively) than the IV-only group (764 ± 217 mL; mean differences = 199 mL [95% CI, 116-283 mL], p < 0.001; 121 mL [95% CI, 38-205 mL], p = 0.001; 131 mL [95% CI, 47-214 mL], p < 0.001); no differences were found among the other three groups. No patients in any study group received an allogeneic transfusion. One patient in the IV-only group had a symptomatic pulmonary embolism develop, but no other symptomatic VTE events occurred in any group. In addition, no differences were observed in wound complications, such as superficial wound necrosis (one patient in the IV-only and the high-dose combined group, respectively) and oozing (IV-only, IA-only, low-dose combined, high-dose combined = 3%, 4%, 4%, and 7%; p = 0.572) between the groups. No patients had a periprosthetic joint infection. CONCLUSION: IA tranexamic acid administration further reduces blood loss after TKA in comparison to IV use alone; no additional effect in further reducing blood loss was found in combination with IV tranexamic acid. Appropriately powered studies are needed to confirm the safety of this route of administration as the preferred route of administration in TKA. LEVEL OF EVIDENCE: Level I, therapeutic study.

Crosscultural Adaptation and Validation of the Korean Version of the New Knee Society Knee Scoring System.

BACKGROUND: The 2011 Knee Society Score© (2011 KS Score©) is used to characterize the expectations, symptoms, physical activity, and satisfaction of patients who undergo TKA and is widely used to assess the outcome of TKA. However, it has not been adapted or validated for use in Korea. QUESTIONS/PURPOSES: We developed a Korean version of the 2011 KS Score and evaluated the (1) test-retest reliability, (2) convergent validity, and (3) responsiveness of the Korean version. METHODS: The Korean version of the 2011 KS Score was derived by using a well-established translational procedure based on international guidelines, which include translation, synthesis, back-translation, expert committee review, pretesting, and submission for appraisal. A total of 123 patients with knee osteoarthritis who were scheduled to undergo TKA were recruited for the study. Ninety percent of the patients (111 of 123) were women, which is an exact representation of the Korean population having TKAs. To evaluate reliability, the patients were evaluated twice during a 4-week interval using the questionnaire. Reliability was assessed by using intraclass correlation coefficients (ICCs) and internal consistency by using Cronbach's alpha to determine the validity of the Korean version of the 2011 KS Score. The patients were evaluated by using the validated Korean versions of the WOMAC and SF-36 questionnaires. Spearman's correlation coefficient was used for validation. Responsiveness was determined by calculating the standardized response mean from the preoperative and postoperative test scores in the Korean version of the 2011 KS Score. To address the gender disparity in our study we identified 53 males who underwent TKA for osteoarthritis after completion of this study and generated age-matched controlled groups to evaluate construct validity and responsiveness in Korean males. RESULTS: The reliability proved good to excellent with an ICC between 0.69 and 0.85, depending on the clinical properties tested, which included the following: symptoms, satisfaction, expectation, and total functional activity consisting of functional activity, standard activity, advanced activity, and discretionary activity. All subscales showed good to excellent internal consistency indicated by Chronbach's alpha (range, 0.83-0.92). For validity, three of the four domains (the exception was expectation) of the 2011 KS Score, correlated either strongly or moderately with the Korean WOMAC score (r ≥ 0.35). When compared with the SF-36, the satisfaction domain showed a weak positive correlation with all the subscales of the SF-36 except general health (r < 0.35). The activity domain showed a strong positive correlation with physical function (r = 0.62) and physical component summary (r = 0.52), moderate with physical role (r = 0.46), and weak with bodily pain (r = 0.26) and social function (r = 0.31). The symptom domain also exhibited a similar moderate positive correlation with physical function (r = 0.41) and weak positive correlation with bodily pain, social function, and physical component summary (r = 0.22, 0.20, and 0.26, respectively). For responsiveness, all the domains of Korean version of the 2011 KS Score, except for expectation, showed large changes (> 0.8), calculated as standardized response mean. The total amount of the Korean version of the 2011 KS Score (2.03, p < 0.001) showed higher responsiveness when compared with the WOMAC total (1.88, p < 0.001) and SF-36 physical and mental component summaries (1.14, p < 0.001; and 0.68, p < 0.001, respectively). CONCLUSIONS: The Korean version of the 2011 KS Score was successfully developed using a process of crosscultural adaptation for the Korean-speaking population who had undergone TKA for osteoarthritis of the knee. The Korean version of the 2011 KS Score was shown to be a reliable, valid, and responsive tool and can be used to assess functional outcomes and expectations of Korean patients who undergo TKA. The demographic features of TKA in the Korean population should be taken into account with additional studies recommended to further investigate these psychometric properties in Korean men. LEVEL OF EVIDENCE: Level II, diagnostic study.

Minimally invasive plate osteosynthesis using 3D printing for shaft fractures of clavicles: technical note.

This article describes a minimally invasive plate osteosynthesis technique for midshaft fractures of clavicles using intramedullary indirect reduction and prebent plates with 3D printing models. This technique allows for easy reduction of fractures with accurate prebent plates and minimal soft tissue injury around the fracture site.