Valgus Arthritic Knee Responds Better to Conservative Treatment than the Varus Arthritic Knee

Background and Objectives: Clinically, it is beneficial to determine the knee osteoarthritis (OA) subtype that responds well to conservative treatments. Therefore, this study aimed to determine the differences between varus and valgus arthritic knees in the response to conservative treatment. We hypothesized that valgus arthritic knees would respond better to conservative treatment than varus arthritic knees. Materials and Methods: Medical records of 834 patients who received knee OA treatment were retrospectively reviewed. Patients with Kellgren-Lawrence grades III and IV were divided into two groups according to knee alignment (varus arthritic knee, hip-knee-ankle angle [HKA] > 0° or valgus arthritic knee, HKA < 0°). The Kaplan-Meier curve with total knee arthroplasty (TKA) as an endpoint was used to compare the survival probability between varus and valgus arthritic knees at one, two, three, four, and five years after the first visit. A receiver operating characteristic (ROC) curve was used to compare the HKA thresholds for TKA between varus and valgus arthritic knees. Results: Valgus arthritic knees responded better to conservative treatment than varus arthritic knees. With TKA as an endpoint, the survival probabilities for varus and valgus arthritic knees were 24.2% and 61.4%, respectively, at the 5-year follow-up (p < 0.001). The thresholds of HKA for varus and valgus arthritic knees for TKA were 4.9° and -8.1°, respectively (varus: area under the ROC curve [AUC] = 0.704, 95% confidence interval [CI] 0.666-0.741, p < 0.001, sensitivity = 0.870, specificity = 0.524; valgus: AUC = 0.753, 95% CI 0.693-0.807, p < 0.001, sensitivity = 0.753, specificity = 0.786). Conclusions: Conservative treatment is more effective for valgus than for varus arthritic knees. This should be considered when explaining the prognosis of conservative treatment for knees with varus and valgus arthritis.

Estimation of the proper gap ratio using preoperative radiography for posterior tibial slope maintenance in biplanar open wedge high tibial osteotomy

BACKGROUND

This study aimed to estimate the ratio of the anterior and posterior gaps before surgery that can minimize the posterior tibial slope (PTS) change through preoperative radiography, and to confirm whether the use of the block helps maintain the PTS during open wedge high tibial osteotomy (OWHTO).

METHODS

Patients who underwent OWHTO between 2015 and 2018 were included. To measure optimal anterior gap (AG) and posterior gap (PG) ratio, hinge to medial tibial tuberosity length (HTL), total osteotomy length (TOL), and PTS were measured using knee AP X-ray. Real AG and PG were measured using postoperative knee computed tomography. Use of the block was also confirmed.

RESULTS

Total 107 knees (95 patients) were included. The average ratio between HTL and TOL was 70.9%. The average ratio AG: PG was 72.9%. PTS increased significantly from 10.2° to 11.2° postoperatively (p = 0.006). When the difference in HTL: TOL and AG: PG, and the amount of PTS change were analyzed using linear regression, there was a statistically significant correlation (correlation coefficient: - 25.9; p < 0.001). There was no difference in AG: PG according to the use of the block (p = 0.882).

CONCLUSION

In OWHTO, PTS change can be minimized by estimating the ratio of the AG and PG using radiographs, and is was approximately 70%. If the ratio is increased by 10% from the predicted value, the PTS increases by approximately 2.6°. Using a block during OWHTO did not have a considerable advantage in terms of PTS maintenance compared to the group not using a block.

LEVEL OF EVIDENCE

Level IV.

The effect of Parkinson's disease on total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

The purpose of this systematic review was to determine the effect of Parkinson's disease (PD) on clinical outcomes and complications after total knee arthroplasty (TKA). Our systematic review was conducted to answer the following questions: (1) does TKA negatively affect clinical outcomes in patients with PD? and (2) does TKA cause more complications in patients with PD?

METHODS

A rigorous and systematic approach was used, and each selected study was evaluated for methodological quality. Data on study design, total number of cases enrolled, follow-up duration, PD severity, clinical outcome, and complications after TKA were analyzed.

RESULTS

Fourteen studies were included. Nine studies reported clinical scores. TKA significantly increased knee and functional scores in the PD group. However, compared with knee and functional scores in the non-PD group, the increase in scores in the PD group was not statistically significant, but tended to be less than that in the non-PD group. Eleven studies reported complications. In six studies, there was no difference in the complication rate between the PD and non-PD group or did not include a control group. In five studies, the PD group had higher medical complication rates and similar or higher surgical complication rates than the non-PD group.

CONCLUSIONS

Patients with PD who underwent TKA showed satisfactory functional improvement and pain reduction. However, these outcomes were not as good as those in the non-PD group. The PD group had a higher probability of occurrence of medical complications than the non-PD group. Further, the PD group had a similar or higher surgical complication rate than the non-PD group.

Quadriceps muscle volume has no effect on patellofemoral cartilage lesions in patients with end-stage knee osteoarthritis

PURPOSE

The quadriceps muscle has a positive effect on anterior knee pain. However, its effect on the patellofemoral (PF) cartilage in patients with end-stage knee osteoarthritis is unknown. The present study aimed to evaluate whether the quadriceps muscle area had a positive effect on the PF cartilage and whether this muscle had a positive effect on the clinical scores.

MATERIALS AND METHODS

Patients with confirmed cartilage status and clinical scores who underwent total knee arthroplasty (TKA) were included. The PF cartilage status was evaluated during TKA. The thickness and the area of the quadriceps muscle were measured using a knee computed tomography scan obtained before the surgery. The Q-angle, hip-knee-ankle angle, alignment, and Insall-Salvati ratio were measured by radiography.

RESULTS

Altogether, 204 patients were included in the study. Logistic regression was performed including factors associated with PF cartilage lesions. The regression model was found to be statistically significant (Hosmer-Lemeshow test, χ² = 0.493). A smaller hip-knee-ankle (HKA) angle was associated with a higher incidence of PF cartilage lesions (p = 0.033) and only the alignment had an effect on the PF cartilage lesions. PF cartilage lesions did not correlate with the clinical scores. A thicker medial portion of the quadriceps muscle was associated with a significantly higher Knee Society Knee Score (KSKS) (p = 0.028).

CONCLUSIONS

Quadriceps muscle thickness and area, Q-angle, and patellar height were not associated with PF cartilage lesions, while a smaller HKA angle was associated with PF cartilage lesions. The presence of PF cartilage lesions did not affect the clinical symptoms. However, a thicker medial portion of the quadriceps muscle was associated with a higher KSKS.

Allogeneic Umbilical Cord Blood-Derived Mesenchymal Stem Cell Implantation Versus Microfracture for Large, Full-Thickness Cartilage Defects in Older Patients: A Multicenter Randomized Clinical Trial and Extended 5-Year Clinical Follow-up

Background:

There is currently no optimal method for cartilage restoration in large, full-thickness cartilage defects in older patients.

Purpose:

To determine whether implantation of a composite of allogeneic umbilical cord blood–derived mesenchymal stem cells and 4% hyaluronate (UCB-MSC-HA) will result in reliable cartilage restoration in patients with large, full-thickness cartilage defects and whether any clinical improvements can be maintained up to 5 years postoperatively.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

A randomized controlled phase 3 clinical trial was conducted for 48 weeks, and the participants then underwent extended 5-year observational follow-up. Enrolled were patients with large, full-thickness cartilage defects (International Cartilage Repair Society [ICRS] grade 4) in a single compartment of the knee joint, as confirmed by arthroscopy. The defect was treated either with UCB-MSC-HA implantation through mini-arthrotomy or with microfracture. The primary outcome was proportion of participants who improved by ≥1 grade on the ICRS Macroscopic Cartilage Repair Assessment (blinded evaluation) at 48-week arthroscopy. Secondary outcomes included histologic assessment; changes in pain visual analog scale (VAS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and International Knee Documentation Committee (IKDC) score from baseline; and adverse events.

Results:

Among 114 randomized participants (mean age, 55.9 years; 67% female; body mass index, 26.2 kg/m²), 89 completed the phase 3 clinical trial and 73 were enrolled in the 5-year follow-up study. The mean defect size was 4.9 cm² in the UCB-MSC-HA group and 4.0 cm² in the microfracture group (P = .051). At 48 weeks, improvement by ≥1 ICRS grade was seen in 97.7% of the UCB-MSC-HA group versus 71.7% of the microfracture group (P = .001); the overall histologic assessment score was also superior in the UCB-MSC-HA group (P = .036). Improvement in VAS pain, WOMAC, and IKDC scores were not significantly different between the groups at 48 weeks, however the clinical results were significantly better in the UCB-MSC-HA group at 3- to 5-year follow-up (P < .05). There were no differences between the groups in adverse events.

Conclusion:

In older patients with symptomatic, large, full-thickness cartilage defects with or without osteoarthritis, UCB-MSC-HA implantation resulted in improved cartilage grade at second-look arthroscopy and provided more improvement in pain and function up to 5 years compared with microfracture.

Registration:

NCT01041001, NCT01626677 (ClinicalTrials.gov identifier).

Comparative Analysis of Diaphyseal versus Metaphyseal tracker Placement in Imageless Navigation Systems for Total Knee Arthroplasty

This work was designed to compare the intraoperative parameters and clinical and radiologic outcomes of total knee arthroplasty (TKA) during a minimum follow-up period of 2 years and to discuss the pros and cons of two different tracker placement (diaphyseal and metaphyseal) navigation systems. The null hypothesis was that there would be no clinical or radiologic difference between the two different systems. Primary TKA was performed in a total of 100 knees using the two different image-free navigation systems (group 1: diaphyseal tracker placement and group 2: metaphyseal tracker placement) with the strict gap balancing technique. Symptom severity was assessed at preoperative and at 3, 6, 12, and 24 months after surgery using the Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Possible adverse issues (major and minor) associated with TKA procedure were observed. Careful assessments were also made of the screw insertion site for infection, stress fractures, and any other related adverse effects. The follow-up periods for groups 1 and 2 were 38 ± 8 months and 38 ± 7 months, respectively. The minimum follow-up period was 24 months. The mechanical alignment improved to 0.1 (valgus) ± 2.2 (group 1) and 0.2 (valgus) ± 2.1 (group 2). There were no radiologic differences between the groups (p > 0.05). In both groups, the KSS and WOMAC improved from before surgery to 24 months after surgery (p < 0.0001). However, the total operation time was 50 ± 5 minutes for group 1, compared to 65 ± 13 minutes for group 2 (p < 0.0001). The metaphyseal tracker navigation system resulted in increased operation time.

Risk of Revision Following Total Knee Arthroplasty or High Tibial Osteotomy: A Nationwide Propensity-Score-Matched Study

BACKGROUND

High tibial osteotomy (HTO) is often performed to postpone or avoid the need for subsequent total knee arthroplasty (TKA). We designed the present study to investigate the incidence rate and risk factors for subsequent revision in patients treated with HTO compared with those managed with TKA.

METHODS

In this retrospective nationwide cohort study, we reviewed the South Korean National Health Insurance claims database from January 1, 2009, to August 31, 2017. We evaluated patients ≥41 years old who had undergone TKA or HTO as the primary surgical procedure without a history of having undergone either procedure during the preceding 2 years. By including only new interventions without such prior surgery, we could eliminate the influence of previous TKA and HTO treatments. Multivariable logistic regression models were used to compare the risk of revision between the groups after propensity score matching with inverse probability of treatment weighting (IPTW). Revision was defined as conversion to revision TKA after primary TKA and conversion to TKA after HTO.

RESULTS

After applying the IPTW, a total of 436,538 patients with TKA and 452,724 patients with HTO were identified. The risk of revision during the entire study period was higher for patients with HTO than for patients with TKA (adjusted hazard ratio [HR], 2.47). The Kaplan-Meier 8-year survival was 97.8% in the TKA group and 91.5% in the HTO group. Compared with patients with TKA, patients with HTO had an increased risk of revision in cases of advanced age (HR of 1.85 for patients who were ≥61 to 69 years old and HR of 4.17 for those who were ≥70 years old), female sex (HR, 2.90), recipients of Medical Aid program benefits (HR, 4.77), the presence of hyperlipidemia (HR, 3.70), the presence of diabetes (HR, 4.86), and the presence of osteoporosis (HR, 3.53). However, younger patients with HTO (≤60 years old) had a lower risk of subsequent revision (HR, 0.64).

CONCLUSIONS

The risk of revision was higher for patients with HTO than for patients with TKA. The risk factors for subsequent revision in patients with HTO in our cohort of patients were advanced age (>60 years), female sex, receipt of Medical Aid, and the presence of comorbidities, such as diabetes, osteoporosis, and hyperlipidemia.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Rotating hinge knee versus constrained condylar knee in revision total knee arthroplasty: A meta-analysis

There is debate in the literature whether rotating hinge knee (RHK) or constrained condylar knee (CCK) prostheses lead to better clinical outcomes and survival rates in patients undergoing revision total knee arthroplasty (RTKA). The purpose of this meta-analysis is to compare the survivorship and clinical outcomes of RHK and CCK prostheses. In this meta-analysis, we reviewed studies that evaluated pain and function scores, range of motion (ROM), complications, and survival rates in patients treated with RHK or CCK with short-term (<5 years) or midterm (5-10 years) follow-up. The survivorship was considered as the time to additional surgical intervention such as removal or revision of the components. A total of 12 studies (one randomized study and 11 non-randomized studies) met the inclusion criteria and were analyzed in detail. The proportion of the knees in which short-term (<5 years) survival rates (RHK, 83/95; CCK, 111/148; odds ratio [OR] 0.52; 95% CI, 0.24-1.11; P = 0.09) and midterm (5-10 years) survival rates (RHK, 104/128; CCK, 196/234; OR 1.05; 95% CI, 0.56-1.97; P = 0.88) were evaluated did not differ significantly between RHK and CCK prostheses. In addition, there were no significant differences in ROM (95% CI: -0.40 to 9.93; P = 0.07) and complication rates (95% CI: 0.66 to 2.49; P = 0.46). In contrast, CCK groups reported significantly better pain score (95% CI: 0.50 to 2.73; P = 0.005) and function score (95% CI: 0.01 to 2.00; P = 0.05) than RHK groups. This meta-analysis revealed that 87.4% of RHK and 75.0% of CCK prostheses survive at short-term (<5 years), while 81.3% of RHK and 83.8% of CCK prostheses survive at midterm (5-10 years). The differences in standardized mean pain and function scores we detected were likely to be imperceptible to patients and almost certainly below the minimum clinically important level, despite a significant difference in both groups. Based on the findings of the current meta-analysis, RHK prostheses continue to be an option in complex RTKA with reasonable midterm survivorship.

Unicompartmental knee arthroplasty fails to completely restore normal gait patterns during level walking

PURPOSE

Gait analysis is a valuable instrument for measuring function objectively after unicompartmental knee arthroplasty (UKA). However, most gait analysis studies have reported conflicting results for functional assessment after UKA. This meta-analysis compared the gait patterns of UKA patients and healthy controls during level walking.

METHODS

Studies were included in the meta-analysis if they recorded vertical ground reaction force (GRF), flexion at initial contact, flexion at loading response, extension at mid-stance, flexion at swing, walking speed, cadence, and stride length in UKA patients or healthy controls.

RESULTS

Seven studies met the criteria for inclusion in the meta-analysis. The UKA patients and healthy controls were similar in terms of vertical GRF (95% CI - 0.54 to 0.23; ns), flexion at initial contact (95% CI - 0.47 to 4.96; ns), flexion at loading response (95% CI - 1.29 to 3.69; ns), and flexion at swing (95% CI - 8.85 to 0.40; ns). In contrast, extension at mid-stance (95% CI 0.53 to 4.88; P = 0.01), walking speed (95% CI - 2.13 to - 0.15; P = 0.02), cadence (95% CI - 1.02 to - 0.25; P = 0.001), and stride length (95% CI - 2.02 to - 0.22; P = 0.01) differed significantly between groups. Subgroup analyses revealed that the pooled data were similar between groups: 1st maximum (heel strike), - 0.43 BW (ns); 1st minimum (mid-stance), 0.61 BW (ns); and 2nd maximum (toe off), - 0.46 BW (ns).

CONCLUSIONS

There were no significant differences in vertical GRF or overall kinematics in the sagittal plane between UKA patients and healthy controls during level walking. However, the UKA group had a significantly slower walking speed and cadence and a shorter stride length than healthy controls. The current findings suggest that, clinically, UKA fails to completely restore normal gait patterns.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Posterior-stabilized inserts are preferable to cruciate-substituting ultracongruent inserts due to more favourable kinematics and stability

PURPOSE

It is unknown whether the conforming superiority of ultracongruent (UC) inserts over posterior stabilized (PS) inserts, due to an increased anterior lip for prevention of anterior displacement of the condyles during knee flexion, leads to better knee scores or greater knee stability in arthroplasty patients. This meta-analysis compared clinical outcomes, intraoperative kinematics, sagittal stability, and range of motion (ROM) between groups with either UC or PS inserts in primary total knee arthroplasty (TKA).

METHODS

Studies that recorded clinical outcomes, intraoperative kinematics, sagittal stability, and ROM in patients who underwent primary TKA with UC or PS inserts were included in the meta-analysis. Subgroup analyses based on differences in flexion angles were performed for intraoperative kinematics.

RESULTS

Thirteen studies met the criteria for inclusion in the meta-analysis. The UC and PS insert groups reported similar pain scores (95% CI - 0.15 to 0.16; n.s.) and function scores (95% CI - 0.30 to 0.14; n.s.). In contrast, femoral rotation during flexion (95% CI - 0.06 to 6.35; p = 0.05), posterior femoral translation during flexion (95% CI - 2.74 to - 0.15; p = 0.03), tibial sagittal laxity at 90° (95% CI 2.91 to 7.72; p < 0.0001), and ROM (95% CI - 4.84 to - 1.53; p = 0.0002) differed significantly between the groups. Subgroup analyses revealed that the pooled data for femoral rotation were significantly different between groups: 60°, 4.09 (p < 0.00001); 90°, 7.94 (p < 0.00001); and 120°, 8.16 (p < 0.00001). Furthermore, pooled data for posterior femoral translation were significantly different between groups: 90°, - 3.70 (p < 0.00001); and 120°, - 3.96 (p < 0.00001).

CONCLUSIONS

There were no significant differences in clinical outcomes between the groups with UC and PS inserts. However, the UC insert group showed significantly greater external femoral rotation, less posterior femoral translation, greater tibial laxity in the sagittal plane, and less ROM than the PS insert group. Based on the results of the current meta-analysis, in substituting the PCL, PS inserts are preferable to UC inserts due to more favourable kinematics and stability, even though both inserts have equivalent clinical outcomes.

LEVEL OF EVIDENCE

Therapeutic study, Level II.

Intra-Articular Injection of Bone Marrow-Derived Mesenchymal Stem Cells Leading to Better Clinical Outcomes without Difference in MRI Outcomes from Baseline in Patients with Knee Osteoarthritis

Purpose

Bone marrow (BM) is frequently used as a source of mesenchymal stem cells (MSCs) because they have a high potential for differentiation. However, it is unclear whether BM-derived MSCs lead to better clinical and magnetic resonance imaging (MRI) outcomes postoperatively.

Materials and Methods

This meta-analysis compared the clinical and MRI outcomes in patients with knee osteoarthritis (OA) treated with BM-derived MSCs. Eight studies comparing the clinical and MRI outcomes assessed with various measurement tools in patients with knee OA treated with BM-derived MSCs were included.

Results

The range of motion (95% confidence interval [CI], −13.05 to 4.24; p=0.32) and MRI outcomes (95% CI, −0.16 to 1.40; p=0.12) did not differ significantly between the baseline and final follow-up. In contrast, pain (95% CI, 0.89 to 1.87; p<0.001) and functional outcomes (95% CI, 0.70 to 2.07; p<0.001) were significantly improved at the final follow-up when compared to the baseline.

Conclusions

This meta-analysis found no significant difference in the tested range of motion and MRI outcomes between the baseline and the final follow-up in patients treated with BM-derived MSCs, whereas significant functional improvement and pain relief were noted when compared with the baseline. Thus, BM-derived MSCs appear to be a viable alternative for patients with knee OA, although long-term and high-quality randomized controlled trials are needed to confirm the clinical benefits.

Effect of shape on bone cement polymerization time in knee joint replacement surgery

BACKGROUND

Although many factors are known to influence the polymerization time of bone cement, it remains unclear which bone cement shape predicts the precise polymerization time. The purpose of this study was to investigate whether different cement shapes influenced polymerization time and to identify the relationship between cement shape and ambient operating theater temperature, relative humidity, and equilibration time.

METHODS

Samples were gathered prospectively from 237 patients undergoing primary total knee arthroplasty. The cement components were made into 2 different shapes: lump and pan. The time at which no macroscopic indentation of both cement models was possible was recorded as the polymerization time.

RESULTS

There was no significant difference between hand mixing (lump shape: 789.3 ± 128.4 seconds, P = .591; pan shape: 899.3 ± 152.2 seconds, P = .584) and vacuum mixing (lump shape: 780.2 ± 131.1 seconds, P = .591; pan shape: 909.9 ± 143.3 seconds, P = .584) in terms of polymerization time. Conversely, the polymerization time was significantly shorter for Antibiotic Simplex (lump shape: 757.4 ± 114.9 seconds, P = .001; pan shape: 879.5 ± 125.0 seconds, P < .001) when compared with Palacos R+G (lump shape: 829.0 ± 139.3 seconds, P = .001; pan shape: 942.9 ± 172.0 seconds, P < .001). Polymerization time was also significantly longer (P < .001) for the pan shape model (904 ± 148.0 seconds) when compared with the lump shape model (785.2 ± 129.4 seconds). In addition, the polymerization time decreased with increasing temperature (lump shape: R = 0.334, P < .001; pan shape: R = 0.375, P < .001), humidity (lump shape: R = 0.091, P < .001; pan shape: R = 0.106, P < .001), and equilibration time (lump shape: R = 0.073, P < .001; pan shape: R = 0.044, P < .001).

CONCLUSIONS

The polymerization time was equally affected by temperature, relative humidity, and equilibration time regardless of bone cement shape. Furthermore, the pan shape model better reflected the cement polymerization time between implant and bone compared with the lump shape model. The current findings suggest that, clinically, constant pressure with the knee in <45° of flexion needs to be applied until remaining pan shaped cement is completely polymerized.

Unsatisfactory clinical outcomes of second-generation mobile bearing floating platform total knee arthroplasty: comparing outcomes with fixed bearing after five years minimum

BACKGROUND

The purpose of this retrospective study was to analyze and compare the clinical and radiologic outcomes of fixed bearing ultracongruent (UC) insert total knee arthroplasty (TKA) and mobile bearing (MB) floating platform TKA using the navigation-assisted gap balancing technique with a minimum follow-up of five years.

METHODS

The study retrospectively enrolled 105 patients who received the UC type fixed bearing insert (group 1) and 95 patients who received the floating platform MB insert (group 2) during the period from August 2009 to June 2012. All surgery was performed using the navigation-assisted gap balancing technique. For strict assessment of gap measurements, the offset-type-force-controlled-spreader-system was used. Radiologic and clinical outcomes were assessed before operation and at the most recent follow-up using the Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. For statistical analysis, paired sample t tests were used. A p value less than 0.05 was considered significant.

RESULTS

Although the radiologic alignments were satisfactory for both groups (99/105 [94%] cases were neutral for group 1 and 90/95 [94%] for group 2), the functional and total WOMAC scores were inferior in group 2 (p < 0.05). There were two cases of insert breakage in group 2 that required bearing exchange. The Kaplan-Meier survivorship rates for groups 1 and 2 at 77 months were 100.0 and 97.9%, respectively.

CONCLUSION

Second-generation MB floating platform TKA cases did not have satisfactory outcomes. There were two cases of insert breakage, which required bearing exchange. Other patients who underwent surgery with second-generation MB floating platform were encouraged to avoid high knee flexion activities, resulting in lower clinical performance.

Arthroscopic suture bridge fixation technique with multiple crossover ties for posterior cruciate ligament tibial avulsion fracture

PURPOSE

This study examined the clinical outcomes of a newly developed technique, arthroscopic suture bridge fixation with crossover ties of PCL tibial avulsion fracture using two tibial tunnels and a posterior trans-septal portal.

METHODS

Records were reviewed of 18 patients (median age 33.5 years, range 13-55 years) with PCL tibial avulsion fractures treated with an arthroscopic suture bridge technique. Knee function before surgery and at last follow-up was evaluated by Lysholm and Tegner scores. A KT-2000 arthrometer was used to evaluate knee stability, and fracture union was assessed by plain radiographs.

RESULTS

Mean postoperative Lysholm (P < 0.001) and Tegner (P = 0.011) scores showed significant improvements compared with preoperative scores. Arthrometry showed that the mean side-to-side difference improved significantly, from 7.8 ± 0.8 mm preoperatively to 3 ± 1.2 mm postoperatively (P = 0.012). Radiographic evaluation showed solid union at the fracture site in all 18 patients at last follow-up.

CONCLUSION

This new arthroscopic double-tunnel pull-out suture bridge fixation with multiple crossover ties and posterior trans-septal technique for PCL tibial avulsion fracture yielded good clinico-radiological outcomes, including satisfactory stability and fracture site healing. This technique can be a useful treatment option for PCL tibial avulsion fracture even with small comminuted fracture due to compression by the unique crossover configuration mesh of multiple fixation sutures.

LEVEL OF EVIDENCE

IV.

Satisfactory Short-Term Results of Navigation-Assisted Gap-Balancing Total Knee Arthroplasty Using Ultracongruent Insert

BACKGROUND

The use of highly conforming ultracongruent (UC) polyethylene insert is bone-preserving and became a relatively common alternative to the conventional posterior stabilized total knee arthroplasty (TKA) design. The purpose of this study was to analyze the short-term clinical and radiologic results of UC insert TKA using the navigation-assisted gap-balancing technique.

METHODS

Two hundred thirty-three knees were operated with a mean follow-up period of 8.1 years (minimum of 5 years). Radiologic and clinical outcomes were assessed before operation and at latest follow-up using the Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index score. For statistical analysis, paired sample t-test and analysis of variance were used. Significance was considered as P < .05.

RESULTS

According to the preoperative deformities (valgus, mild varus, and moderate varus), there were 23 cases (9.9%) of valgus deformity, 180 cases (77.3%) of mild varus deformity, and 30 cases (12.9%) of moderate varus deformity. Overall, the results at mean 8.1 years revealed an improvement in mean Knee Society Score (54 ± 12 to 92 ± 3) and mean Western Ontario and McMaster Universities Osteoarthritis Index scores (62 ± 14 to 17 ± 3). Overall, 220 of 233 cases (94.4%) were in neutral alignment (between -3° and +3°) at latest follow-up. There were no migrating or shifting prosthesis that should be considered as possible failure. There was 0% component revision rate.

CONCLUSION

Navigation-assisted gap-balancing technique using UC insert TKA had satisfactory short-term outcome. Strict gap-balancing technique using the offset-type-force-controlled-spreader-system aided in the satisfactory results.

Snapping Phenomenon after Revisional Total Knee Arthroplasty

The cases of revision total knee arthroplasty (TKA) are increasing. In this report, snapping phenomenon after final implantation of revision TKA has been presented. Snapping was caused by adhered iliotibial band (ITB) impinging against the lateral part of femoral component. Fractional lengthening the ITB by puncture resolved the snapping phenomenon. Surgeons should be aware of the presence of such a case which should be identified during operation to avoid secondary operations.

Use of autogenous onlay bone graft for uncontained tibial bone defects in primary total knee arthroplasty

Background

The use of autogenous bone graft is a well–known technique for reconstruction of tibial bone defects in primary total knee arthroplasty (TKA). In cases where the size of the bone graft is inappropriate, the stability of bone graft fixation and subsequent bone graft to host bone incorporation may be compromised. We describe a simple and reliable technique of reconstruction in a proximal tibia bone defect at the time of primary TKA by using autogenous onlay bone graft (AOBG).

Methods

Records were reviewed of 19 patients (mean age, 72 years) who underwent primary TKA using AOBG without the additional allogenous bone or metal augments, between August 2013 and August 2014.

Results

Mean Knee Society score (KSS) in the 22 knees was significantly higher postoperatively than preoperatively (92 ± 4 vs. 30 ± 7, P < 0.001). The mean range of motion (ROM) in the 22 knees, which was 106 ± 12° preoperatively, improved to 112 ± 10° at last follow-up, but this this difference was not significant (P = 0.32). No migration of implants and presence of radiolucent lines at the bone cement-prosthesis interface were observed. Furthermore, the serial radiographs of 19 patients had a mean time of 3.2 months (range, 2.7–4.4 months) for solid union with cross trabeculation between the proximal tibial bone and graft.

Conclusions

This simple AOBG supplement technique may biologically promote graft to host bone healing by enhancing fixation stability without the additional fixatives and assist the surgeon in managing the varying nature of uncontained bone defects.

Trial registration

Trial registration number: KCT0002328, May 15, 2017.

Intravenous versus topical tranexamic acid administration in primary total knee arthroplasty: a meta-analysis

PURPOSE

This meta-analysis was designed to compare the effectiveness and safety of intravenous (IV) versus topical administration of tranexamic acid (TXA) in patients undergoing primary total knee arthroplasty (TKA) by evaluating the need for allogenic blood transfusion, incidence of postoperative complications, volume of postoperative blood loss, and change in haemoglobin levels.

METHODS

Studies were included in this meta-analysis to check whether they assessed the allogenic blood transfusion rate, postoperative complications including pulmonary thromboembolism (PTE) or deep vein thrombosis (DVT), volume of postoperative blood loss via drainage, estimated blood loss, total blood loss, and change in haemoglobin levels before and after surgery in primary TKA with TXA administered through both the IV and topical routes.

RESULTS

Ten studies were included in this meta-analysis. The proportion of patients requiring allogenic blood transfusion (OR 1.34, 95 % CI 0.63-2.81; n.s.) and the proportion of patients who developed postoperative complications including PTE or DVT (OR 0.85, 95 % CI 0.41 to 1.77; n.s.) did not significantly differ between the two groups. There was 52.3 mL less blood loss via drainage (95 % CI -50.74 to 185.66 mL; n.s.), 52.1 mL greater estimated blood loss (95 % CI -155.27 to 51.03 mL; n.s.), and 51.4 mL greater total blood loss (95 % CI -208.16 to 105.31 mL; n.s.) in the topical TXA group as compared to the IV TXA group. The two groups were also similar in terms of the change in haemoglobin levels (0.02 g/dL, 95 % CI -0.36 to 0.39 g/dL; n.s.).

CONCLUSIONS

In primary TKA, there are no significant differences in the transfusion requirement, postoperative complications, blood loss, and change in haemoglobin levels between the IV and topical administration of TXA. In addition, results from subgroup analysis evaluating the effect of the times of TXA administration through the IV route suggested that double IV dose of TXA is more effective than single dose in terms of the transfusion requirements and blood loss via drainage. The current meta-analysis indicates that IV administration of 10 mg/kg of TXA 20 min before inflation of the tourniquet followed by 10 mg/kg of TXA 15 min before deflation of the tourniquet is effective and safe. The topical administration of 2 g of TXA mixed with 100 mL of normal saline after wound closure could be an alternative option in patients at greater risk of thromboembolic complications.

LEVEL OF EVIDENCE

Meta-analysis, Level III.

Proprioception in patients with posterior cruciate ligament tears: A meta-analysis comparison of reconstructed and contralateral normal knees

Posterior cruciate ligament (PCL) reconstruction for patients with PCL insufficiency has been associated with postoperative improvements in proprioceptive function due to mechanoreceptor regeneration. However, it is unclear whether reconstructed PCL or contralateral normal knees have better proprioceptive function outcomes. This meta-analysis was designed to compare the proprioceptive function of reconstructed PCL or contralateral normal knees in patients with PCL insufficiency. All studies that compared proprioceptive function, as assessed with threshold to detect passive movement (TTDPM) or joint position sense (JPS) in PCL reconstructed or contralateral normal knees were included. JPS was calculated by reproducing passive positioning (RPP). Five studies met the inclusion/exclusion criteria for the meta-analysis. The proprioceptive function, defined as TTDPM (95% CI: 0.25 to 0.51°; P<0.00001) and RPP (95% CI: 0.19 to 0.45°; P<0.00001), was significantly different between the reconstructed PCL and contralateral normal knees. The mean difference in angle of error between the reconstructed PCL and contralateral normal knees was 0.06° greater in TTDPM than by RPP. In addition, results from subgroup analyses, based on the starting angles and the moving directions of the knee, that evaluated TTDPM at 15° flexion to 45° extension, TTDPM at 45° flexion to 110° flexion, RPP in flexion, and RPP in extension demonstrated that mean angles of error were significantly greater, by 0.38° (P = 0.0001), 0.36° (P = 0.02), 0.36° (P<0.00001), and 0.23° (P = 0.04), respectively, in reconstructed PCL than in contralateral normal knees. The proprioceptive function of PCL reconstructed knees was decreased, compared with contralateral normal knees, as determined by both TTDPM and RPP. In addition, the amount of loss of proprioception was greater in TTDPM than in RPP, even with minute differences. Results from subgroup analysis, that evaluated the mean angles of error in moving directions through RPP, suggested that the moving direction of flexion has a significantly greater mean for angles of error than the moving direction of extension. Although the level of differences between various parameters were statistically significant, further studies are needed to determine whether the small differences (>1°) of the loss of proprioception are clinically relevant.

Comparison of kinematic and mechanical alignment techniques in primary total knee arthroplasty: A meta-analysis

BACKGROUND

This meta-analysis compared clinical and radiographic outcomes and complications of kinematic alignment (KA) and mechanical alignment (MA) techniques in primary total knee arthroplasty (TKA).

METHODS

All studies comparing the operation time, change in hemoglobin, length of hospital stay, postoperative complications, and clinical and radiographic outcomes as assessed with various measurement tools, from direct interview to imaging methods, in patients who underwent primary TKA through the KA or MA technique were included.

RESULTS

Six studies were included in the meta-analysis. The proportion of patients who developed postoperative complications (OR: 1.10, 95% CI: 0.49-2.46; P = .69) did not differ significantly between the KA and MA techniques. The 2 groups were also similar in terms of change in hemoglobin (95% CI: -0.38 to 0.34; P = .91), length of hospital stay (95% CI: -0.04 to 0.55; P = .10), hip-knee-ankle angle (95% CI: -1.76 to 0.75; P = .43), joint line orientation angle (95% CI: -4.27 to 4.23; P = .99), tibial component slope (95% CI: -0.53 to 3.56; P = .15), and femoral component flexion (95% CI: -2.61 to 7.57; P = .34). In contrast, operation time (95% CI: -27.16 to -3.71; P = .01), overall functional outcome (95% CI: 6.59-11.51; P < .0001), knee anatomical axis (95% CI: -1.38 to -0.01; P = .05), femoral component relative to the mechanical axis (95% CI: -2.47 to -1.40; P < .0001), and tibial component relative to the mechanical axis (95% CI: 1.56-2.95; P < .0001) were significantly different between the 2 groups.

CONCLUSIONS

There were no significant differences in postoperative complications, change in hemoglobin, length of hospital stay, hip-knee-ankle angle, joint line orientation angle, tibial component slope, or femoral component flexion between the KA and MA techniques for primary TKA. However, the KA technique resulted in a significantly shorter operation time and better overall functional outcome than the MA technique, even though the femoral component was placed in a slightly more valgus position relative to the mechanical axis and the tibial component in a slightly more varus position with the KA technique.

Tibial nerve neuropathy following medial opening-wedge high tibial osteotomy-case report of a rare technical complication

A 63-year-old woman developed tibial nerve injury caused by an overlong K wire and 4.5-mm cortical lag screw through the first distal hole below the osteotomy during medial opening-wedge high tibial osteotomy (HTO), leading to a lack of sensation on the sole of the foot with no disturbances in motor functions. The temporary lag screw in the first distal hole below the osteotomy is often inserted by an excessive length in order to compress the potentially fractured opposite cortex. By doing so, posterior neurovascular structures including the tibial nerve and the popliteal vessels can be injured. To avoid this type of injury during medial opening-wedge HTO, proper knee position and appropriate Hohmann retractor position in combination with meticulous insertion of the K wire or screw under fluoroscopic control are essential. In addition, our study reinforces the fact that different presentations of injury to the tibial nerve should be carefully considered in the absence of common diagnostic features, including weakness of the toe flexors and posterior tibial muscle of the leg with intractable pain.

Proximal tibial anterior open-wedge oblique osteotomy: A novel technique to correct genu recurvatum

BACKGROUND

For successful acute correction of genu recurvatum, accurate correction of plateau angle, restoration of anatomical axis, rigid fixation, and preservation of patellar height are essential. However, a surgical treatment that satisfies all these conditions has not yet been established. The purpose of this study was to evaluate the novel technique of proximal tibial anterior open-wedge oblique osteotomy (PT-AOWOO) for the treatment of genu recurvatum.

METHODS

Five patients with genu recurvatum underwent PT-AOWOO from 2008 to 2013. The open-wedge center of rotation of angulation (CORA) was determined by the intersection of transverse bisector line and tibial posterior cortex to prevent secondary translational deformity. An osteotomy was performed from the distal margin of the tibial tuberosity to the planned CORA to maintain patellar height and provide sufficient space for fixation. The opening gap was calculated by the picture-archiving and communications system (PACS)-Photoshop method.

RESULTS

The mean angle of recurvatum was 17° (range, 14 to 25°) preoperatively and -0.4° (range, -5° to 5°) postoperatively. The mean angle of the tibial plateau was 79.8° (range, 67 to 85°) preoperatively and 98.4° (range, 95 to 105°) postoperatively. Tibial anatomical axis was restored and the patellar height was maintained in all patients. The overall results were excellent in three patients and good in two patients.

CONCLUSIONS

The PT-AOWOO and its unique osteotomy level corrected the tibial plateau angle accurately, restored the sagittal tibial axis without translation, maintained patellar height, and enabled rigid fixation. This technique showed satisfactory radiologic and clinical outcomes without any complications.

Comparison between two angular stable locking plates for medial opening-wedge high tibial osteotomy: Decisive wedge locking plate versus TomoFix™

BACKGROUND

An adequate stable fixation implant should be used for medial opening-wedge high tibial osteotomy (MOWHTO) to promote rapid bone healing without complications. This study compared the radiographic and clinical outcomes as well as plate-specific complications between two angular stable locking plates in patients following MOWHTO.

METHOD

This prospective study involved 97 patients (50 with DWL^®, group I; 47 with TomoFix™, group II) undergoing MOWHTO for primary medial compartment osteoarthritis between 2010 and 2013. Clinical and radiographic evaluations were performed by using the HSS and WOMAC scores, and calculating mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and posterior tibial slope (PTS) on radiographs both preoperatively and after 3 years.

RESULTS

A statistically significant difference was observed for the MPTA at the last follow-up between the two groups (P = 0.033). Additionally, the last follow-up MPTA of group I was associated with the osteotomy technique (P = 0.004) and preoperative JLCA (P = 0.034) whereas the last follow-up MPTA of group II was associated with gender (P = 0.001) and BMI (P = 0.008). Furthermore, the results showed that group I had a higher rate of non-union (4%) compared to that in group II (0%).

CONCLUSION

Both locking plates are useful tools in the treatment of medial compartment knee osteoarthritis with varus deformity in young, active patients. However, under special consideration of the complication we found in present study, the TomoFix™ seems to be a better alternative in using the MOWHTO for highly demanding patients.

Minimally invasive navigation-assisted versus conventional total knee arthroplasty: a meta-analysis

PURPOSE

It is unclear whether the minimally invasive navigation-assisted (MINA) or conventional (CONv) approach for primary total knee arthroplasty (TKA) leads to better clinical and radiographic outcomes. This meta-analysis compared the clinical and radiographic outcomes of the MINA and CONv approaches after primary TKA. It was hypothesized that there was no difference in clinical and radiographic outcomes between the two surgical approaches for primary TKA.

METHODS

This meta-analysis reviewed all studies that compared surgical time, incision length, flexion range of motion (ROM), Knee Society Score ( KSS), coronal mechanical axis (CMA), and coronal femoral component angle (CFCA) with various measurement tools, from direct interview to plain radiography, between the MINA and CONv approaches.

RESULTS

Five studies met the inclusion/exclusion criteria for the meta-analysis. The findings of this study suggest that surgical time (95 % CI -18.51 to 39.09; n.s.), KSS (95 % CI -8.55 to 30.84; n.s.), CMA (95 % CI -1.01 to 0.54; n.s.), and CFCA (95 % CI -0.91 to 2.97; n.s.) were similar between the two surgical approaches, whereas incision length (95 % CI -5.18 to -3.69; P < 0.001) was significantly shorter in the MINA approach and flexion ROM (95 % CI 14.26-19.01; P < 0.001) was significantly greater in the MINA approach.

CONCLUSIONS

There were no significant differences in clinical and radiographic outcomes, including surgical time, KSS, CMA, and CFCA, in patients who underwent MINA and CONv approach for primary TKA, but the MINA approach resulted in a slightly shorter incision length and increased flexion ROM than the CONv approach. Therefore, if particular attention has to be paid to patient's selection with appropriate counselling and surgeon's experience, MINA approach can provide early clinical benefit when compared with CONv approach. Besides, orthopaedic surgeons need to master the MINA and CONv approaches because both approaches have similar clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Therapeutic study, Level II.

Development, Quantification, Method Validation, and Stability Study of a Novel Fucoxanthin-Fortified Milk

To extend the scope of application of fucoxanthin, a marine carotenoid, whole milk (WM) and skimmed milk (SM) were fortified with fucoxanthin isolated from the microalga Phaeodactylum tricornutum to a final 8 μg/mL milk solution concentration. Using these liquid systems, a fucoxanthin analysis method implementing extraction and HPLC-DAD was developed and validated by accuracy, precision, system suitability, and robustness tests. The current method demonstrated good linearity over the range of 0.125-100 μg/mL fucoxanthin with R(2) = 1.0000, and all validation data supported its adequacy for use in fucoxanthin analysis from milk solution. To investigate fucoxanthin stability during milk production and distribution, fucoxanthin content was examined during storage, pasteurization, and drying processes under various conditions. Fucoxanthin in milk solutions showed better stabilizing effect in 1 month of storage period. Degradation rate constant (k) on fucoxanthin during this storage period suggested that fucoxanthin stability might be negatively correlated with decrease of temperature and increase of protein content such as casein and whey protein in milk matrix. In a comparison between SM and WM, fucoxantin in SM always showed better stability than that in WM during storage and three kinds of drying processes. This effect was also deduced to relate with protein content. In the pasteurization step, >91% of fucoxanthin was retained after three pasteurization processes even though the above trend was not found. This study demonstrated for the first time that milk products can be used as a basic food matrix for fucoxanthin application and that protein content in milk is an important factor for fucoxanthin stability.

Alignment in knee flexion position during navigation-assisted total knee arthroplasty

PURPOSE

The aim of this study was to demonstrate the lower limb alignment in knee flexion position after navigation-assisted total knee arthroplasty using the gap technique and to identify the correlative factors.

METHODS

One hundred and twenty consecutive osteoarthritic knees (120 patients) were prospectively enrolled for intraoperative data collection. All TKA surgeries were performed using the navigation system (OrthoPilot™, version 4.0; B. Braun Aesculap, Tuttlingen, Germany). Before and after final prosthesis implantation, the lower limb navigation alignment in both knee extension (0°) and knee flexion (90°) position was recorded. The knee flexion alignment was divided into three groups: varus, neutral and valgus alignment. To determine the factors of the alignment in knee flexion position, preoperative demographics, radiologic and intraoperative data were obtained. Pearson's correlation (r) analysis was performed to find the correlation. The Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index were compared between groups.

RESULTS

Although all postoperative extension alignment was within neutral position (between -2° and +2°), postoperative knee flexion alignment was divided into three groups: varus (≤-3°), 24 cases (20 %); neutral (between -2° and +2°), 85 cases (70.8 %) and valgus (≥+3°) alignment, 11 cases (9.2 %). There were a good correlation of alignment in knee flexion position with the rotation of femoral component relative to posterior condylar axis (r = -0.502, p = 0.000) and weak correlations with posterior femoral cut thickness (lateral condyle) (r = 0.207, p = 0.026), medial flexion (90°) gap after femoral component rotation adjustment (r = 0.276, p = 0.003). Other variables did not show correlations. There were no statistical clinical differences between varus, neutral and valgus knee flexion alignment groups.

CONCLUSION

About 30 % of the cases showed malalignment of more than 3° in knee flexion position although with neutral alignment in extension position. The knee flexion alignment had a good correlation with the rotation of femoral component relative to posterior condylar axis. Neutral alignment in knee flexion position may be adjusted by femoral component rotation especially by the use of navigation system.

LEVEL OF EVIDENCE

IV.

A Novel Medial Soft Tissue Release Method for Varus Deformity during Total Knee Arthroplasty: Femoral Origin Release of the Medial Collateral Ligament

Introduction

Numerous methods of medial soft tissue release for severe varus deformity during total knee arthroplasty (TKA) have been reported. These include tibial stripping of the superficial medial collateral ligament (MCL), pie-crusting technique, and medial epicondylar osteotomy. However, there are inherent disadvantages in these techniques. Authors hereby present a novel quantitative method: femoral origin release of the medial collateral ligament (FORM).

Surgical Technique

For medial tightness remaining even after the release of the deep MCL and semimembranosus, the FORM is initiated with identification of the femoral insertion area of the MCL with the knee in flexion. Starting from the most posterior part of the femoral insertion, one third of the MCL femoral insertion is released from its attachment. If necessary, further sequential medial release is performed.

Materials and Methods

Seventeen knees that underwent the FORM were evaluated for radiological and clinical outcomes.

Results

Regardless of the extent of the FORM, no knees showed residual valgus instability at 24 weeks after surgery.

Conclusions

As the FORM is performed in a stepwise manner, fine adjustment during medial release might be beneficial to prevent inadvertent over-release of the medial structures of the knee.

Imageless Navigation Versus Conventional Open Wedge High Tibial Osteotomy: A Meta-Analysis of Comparative Studies

Purpose

To summarize and compare radiological and clinical outcomes of open wedge high tibial osteotomy (HTO) using imageless computer-assisted navigation with conventional HTO.

Methods

A literature search of online register databases was conducted. The risk ratio (RR) of radiological outliers and mean differences in clinical outcomes were compared between navigated and conventional HTOs. Radiological results were evaluated by subgroup analyses according to the study period (concurrent/consecutive) and the use of locking fixation device.

Results

Seven comparative studies with a total sample size of 406 knees were included in this review. Radiographically, the mechanical axis [MA] was within the acceptable range (0°–6°) in 83.7% of the navigation HTO group, showing significant difference from 62.1% of the conventional HTO group. Clinically, despite the forest plot demonstrating a general trend of favoring the navigation system, there were not sufficient studies to determine statistical significance in the meta-analysis. None of the subgroup analyses demonstrated significant differences in the RR of MA outliers.

Conclusions

The present meta-analysis indicates that the use of navigation in open wedge HTO improves the precision of mechanical alignment by decreasing the incidence of outliers; however, the clinical benefit is not conclusive. Additionally, none of the subgroup analyses demonstrated significant difference in the RR of MA outliers.

Subcutaneous versus intraarticular closed suction indwelling drainage after total knee arthroplasty: A randomised control trial

BACKGROUND

Total knee arthroplasty (TKA) is widely accepted treatment for moderate or severe osteoarthritis and rheumatoid arthritis. Significant blood loss can be seen during the early postoperative period where a blood transfusion may be necessary. Closed suction drainage is known to prevent the formation of hematomas in the operative field, decrease tension on incisions, diminish delayed wound healing and reduce the risk of infection. Subcutaneous indwelling closed suction drainage method has been known to be beneficial and an alternative to the intraarticular indwelling method. This prospective randomized study was to compare the visible, hidden, total blood loss and postoperative hemodynamic change of subcutaneous and intraarticular indwelling closed suction drainage method after TKA.

MATERIALS AND METHODS

One hundred and sixty patients with primary osteoarthritis who underwent unilateral TKA were enrolled; group A with subcutaneous (n = 78) and group B with intraarticular (n = 79) indwelling closed suction drainage method. Total blood loss, visible blood loss, internal blood loss, postoperative day 1, 5(th), 10(th) day hemoglobin, hematocrit levels were compared. Allogeneic blood transfusion rate and complications related to soft tissue hematoma formation were additionally compared.

RESULTS

Allogenic transfusion requirements between subcutaneous drainage group and intraarticular drainage groups (6.4% vs. 24.1%) were significantly different (P = 0.002). Although the minor complications such as the incidence of bullae formation and the ecchymosis were higher in the subcutaneous indwelling group, the functional outcome at postoperative 2 year did not demonstrate the difference from intraarticular drainage group.

CONCLUSION

Subcutaneous indwelling closed suction drainage method is a reasonable option after TKA for reduction of postoperative bleeding and transfusion rate.

Loose body as an obstacle for posterolateral arthroscopic portal formation in the knee joint

In this report, we present a case with difficult arthroscopic posterolateral portal formation due to loose body located in posterior compartment. These loose bodies are responsible for pain, decreased range of motion and cartilage damage in the knee joint. By making the posterior trans-septal portal prior, posterolateral portal could be made without difficulty completing the planned arthroscopic procedure.

Influence of Mixed Solvent on the Electrochemical Property of Hybrid Capacitor

The hybrid capacitors (2245 size, cylindrical type) were prepared by using activated carbon cathode and Li4Ti5O12 anode. In order to improve the cell operation at high temperature range, propylene carbonate (PC) was used in combination with acetonitrile (AN) with volume ratio of 7:3, 5:5, and 3:7, respectively. We investigated the electrochemical behavior of the hybrid capacitors that enabled cell operation with stability at high temperature. The organic electrolyte of hybrid capacitor containing PC and AN with a volume ratio 7:3 intended to exhibit highly reversible cycle performance with good capacity retention at 60 degrees C after 2200 cycles. From this study, it has been found that the very strong influence of the solvent nature on the characteristics of hybrid capacitor, and the difference in performance associated with the two solvents.

Current status of second-look arthroscopy after meniscal allograft transplantation: review of the literature

INTRODUCTION

Clinical assessments do not accurately reflect the status of meniscal transplants and cannot evaluate the graft condition itself and joint preservation effects of meniscal allograft transplantation correctly. The purpose of this review was to assess the need and to ascertain the indication and the role of second-look arthroscopy for objective evaluation after MAT.

MATERIALS AND METHODS

We performed a literature search to identify all published clinical studies on MAT with the following medical subject heading (MeSH) terms: "meniscus," "meniscal transplant," "transplantation and allograft," "meniscal and transplant." Include in the review are studies with at least 6 months clinical, radiological, and/or histological follow-up in human subjects. Evaluation method of MAT was reviewed with an aim to describe the frequency of second-look arthroscopy, its feasibility, patient compliance, purposes, and results.

RESULTS

We identified 15 clinical studies that satisfied our inclusion and exclusion criteria. Only two studies always performed second-look arthroscopies. Most of the second-look arthroscopy was conducted mainly for the objective evaluation of meniscal allograft transplantation but, in several studies, arthroscopy was performed to treatment of other knee problem.

CONCLUSIONS

Although second-look arthroscopy has inevitably ethical issues, especially for asymptomatic and well-functioning knees, in this review, it could be a more dependable method available to detect meniscal healing if performed for certain indications such as a symptomatic patient with a magnetic resonance image indicating abnormalities.

The use of contralateral knee magnetic resonance imaging to predict meniscal size during meniscal allograft transplantation

PURPOSE

The purpose of this study was to determine the size of each meniscus and compare it with the contralateral limb using conventional knee magnetic resonance imaging (MRI) taken from previously uninjured, healthy, young volunteers.

METHODS

The knee joints of 60 healthy volunteers (aged 21 to 43 years, 30 men and 30 women) were enrolled in this study. Standard 3.0-T MRI in a controlled setting was used. By use of the mid-coronal images, the height and width of each medial and lateral meniscus were measured. By use of the mid-sagittal images, the height and width of the anterior and posterior horns of each meniscus was measured. The whole length spanning from the most anterior margin to the most posterior margin of each meniscus was also measured. Mean, standard deviation, and 95% confidence interval values were determined for each measurement.

RESULTS

There were 3 incomplete discoid lateral menisci (10%) in men and 2 incomplete discoid menisci (6.7%) in women. The study group with non-discoid knees comprised 27 men and 28 women. The power of this study ranged from 0.57 to 0.66. All values showed good reliability (intraclass correlation coefficient range, 0.887 to 0.974). There were no significant differences between right and left menisci (all P > .05). There were significant differences between genders. All parameters showed significant differences (P < .05) except the medial meniscus width (P = .221).

CONCLUSIONS

In this small subset of patients, there were no differences between right and left meniscal measurements according to MRI. Therefore, when one is performing meniscal allograft transplantation, contralateral knee MRI may be useful to determine the required size. Identifying both the overall width and length of each meniscus is important when preparing an allograft.

CLINICAL RELEVANCE

Contralateral knee MRI may be used for more accurate meniscal size measurement in patients undergoing meniscal allograft transplantation.

Navigated Acetabular Cup Fixation for Acetabular Deformity or Revision Total Hip Arthroplasty

Purpose

To evaluate the usefulness of navigated acetabular cup fixation for total hip arthroplasty in patients with acetabular deformity or revision total hip arthroplasty.

Materials and Methods

This study enrolled 28 patients with at least 12 months' follow-up. The safe zone of the acetabular cup was defined as 40°±10°in inclination and 15°±10°in anteversion. The authors used the navigation and radiographic data to determine whether the acetabular cup was located within the safe zone or not. To evaluate the clinical outcomes, preoperative and last follow-up Harris hip scores were checked, and the occurrence of complications was evaluated.

Results

According to the navigation data, the mean inclination and anteversion were 38.5°±4.7°(range, 32°-50°) and 16.6°±4.0°(range, 8°-23°), respectively. According to the radiographic data the mean inclination and anteversion were 40.5°±4.6°(range, 32°-50°) and 19.4°±4.2°(range, 8°-25°), respectively. In both cases, all values were within the safe zone. Harris hip score was improved in all patients from preoperative 52.3±14.4 points (range, 29-87 points) to 88.0±9.0 points (range, 65-99 points) at the last follow-up. There was no dislocation or loosening of both cases.

Conclusion

Navigated acetabular cup fixation is a useful technique for total hip arthroplasty in patients with acetabular deformity or revision total hip arthroplasty because it prevents the malposition and related complications.

Thrombospondin-2 secreted by human umbilical cord blood-derived mesenchymal stem cells promotes chondrogenic differentiation

Increasing evidence indicates that the secretome of mesenchymal stem cells (MSCs) has therapeutic potential for the treatment of various diseases, including cartilage disorders. However, the paracrine mechanisms underlying cartilage repair by MSCs are poorly understood. Here, we show that human umbilical cord blood-derived MSCs (hUCB-MSCs) promoted differentiation of chondroprogenitor cells by paracrine action. This paracrine effect of hUCB-MSCs on chondroprogenitor cells was increased by treatment with synovial fluid (SF) obtained from osteoarthritis (OA) patients but was decreased by SF of fracture patients, compared to that of an untreated group. To identify paracrine factors underlying the chondrogenic effect of hUCB-MSCs, the secretomes of hUCB-MSCs stimulated by OA SF or fracture SF were analyzed using a biotin label-based antibody array. Among the proteins increased in response to these two kinds of SF, thrombospondin-2 (TSP-2) was specifically increased in only OA SF-treated hUCB-MSCs. In order to determine the role of TSP-2, exogenous TSP-2 was added to a micromass culture of chondroprogenitor cells. We found that TSP-2 had chondrogenic effects on chondroprogenitor cells via PKCα, ERK, p38/MAPK, and Notch signaling pathways. Knockdown of TSP-2 expression on hUCB-MSCs using small interfering RNA abolished the chondrogenic effects of hUCB-MSCs on chondroprogenitor cells. In parallel with in vitro analysis, the cartilage regenerating effect of hUCB-MSCs and TSP-2 was also demonstrated using a rabbit full-thickness osteochondral-defect model. Our findings suggested that hUCB-MSCs can stimulate the differentiation of locally presented endogenous chondroprogenitor cells by TSP-2, which finally leads to cartilage regeneration.

Bilateral condyle fracture of tibial insert in mobile bearing total knee arthroplasty

We report a case of polyethylene insert breakage in a 45-year-old man after 3.5 years of cruciate retaining type mobile bearing total knee arthroplasty (TKA). Interstingly, both condyles of the polyethylene insert have fractured. The visual assessment done by stereoscopic microscope in the investigation report suggested that the fracture propagation was a result of cyclic loading and that the fracture was from the articular surface as a result of tibio-femoral and anteroposterior shear loading. The initial flexion-extension gap mismatch and/or specific Asian habits like kneeling or deep knee bending could have been the possible factors for over-stress for the insert causing this complication. After replacement of the broken insert and modification for daily activity preventing deep knee flexion, the patient obtained complete relief of previous symptoms. It remains unclear whether insert breakage was secondary to polyethylene insufficient design or to the polyethylene material fracture propagation.

Predictive value of painful popping for a posterior root tear of the medial meniscus in middle-aged to older Asian patients

PURPOSE

The purpose of this study was to determine the accuracy, sensitivity, specificity, and predictive values of a single event of painful popping in the presence of a posterior root tear of the medial meniscus in middle-aged to older Asian patients.

METHODS

We conducted a retrospective review of medical records of 936 patients who underwent arthroscopic surgeries for an isolated medial meniscus tear between January 2000 and December 2010. There were 332 men and 604 women with a mean age of 41 years (range, 25 to 66 years). The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of a painful popping sensation for a posterior root tear of the medial meniscus were calculated.

RESULTS

Arthroscopy confirmed the presence of posterior root tears of the medial menisci in 237 of 936 patients (25.3%). A single event of a painful popping sensation was present in 86 of these 936 patients (9.1%). Of these 86 patients with a painful popping sensation, 83 (96.5%) were categorized as having an isolated posterior root tear of the medial meniscus. The positive predictive value of a painful popping sensation in identifying a posterior root tear of the medial meniscus was 96.5%, the negative predictive value was 81.8%, the sensitivity was 35.0%, the specificity was 99.5%, and the diagnostic accuracy was 77.9%.

CONCLUSIONS

A single event of painful popping can be a highly predictive clinical sign of a posterior root tear of the medial meniscus in the middle-aged to older Asian population. However, it has low sensitivity for the detection of a posterior root tear of the medial meniscus.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Total knee arthroplasty in a pseudoachondroplastic dwarfism patient with bilateral patellar dislocation

Late presentation of congenital patellar dislocation with advanced osteoarthritis is rare. This article presents a case of a 59-year-old man with underlying pseudoachondroplastic dwarfism. Advanced osteoarthritis due to bilateral neglected congenital patellar dislocation was treated with total knee arthroplasty without patella relocation surgery. Two years later, the patient had an improvement in Knee Society scores, painless function, and stability.

The management of the popliteus hiatus during lateral meniscal transplantation

Popliteofascicular injury had been proposed as a possible cause of unstable lateral meniscus. Meniscal repair at popliteal hiatus area during lateral meniscal allograft transplantation (MAT) had not been described in literature previously. In this report, a case of unstable lateral meniscus after MAT has been described. Arthroscopic repair for the unstable meniscus at popliteal hiatus resolved the mechanical symptom.

Comparison of the predictive power of the LODS and APACHE II scoring systems in a neurological intensive care unit

OBJECTIVE

A prospective study to compare the power of the Logistic Organ Dysfunction System (LODS) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring systems to predict survival, in patients admitted to the neurological intensive care unit (NICU).

METHODS

Clinical data from 521 consecutive NICU patients were collected during the first 24 h of admission and were used to compare the predictive power of both scoring systems.

RESULTS

The observed mortality rate was 10.0% compared with predicted mortality rates of 7.2% and 4.8% according to LODS and APACHE II, respectively. Both scoring systems had excellent discrimination but LODS had superior calibration.

CONCLUSION

The LODS scoring system was more stable than the APACHE II scoring system in the NICU setting.

Second-look arthroscopic assessment of arthroscopic single-bundle posterior cruciate ligament reconstruction: comparison of mixed graft versus achilles tendon allograft

BACKGROUND

Although controversy continues over the choice of graft tissue, including autografts, allografts, and synthetic ligaments, for posterior cruciate ligament (PCL) reconstruction, the use of a mixed graft consisting of a hamstring (semitendinosus and gracilis) autograft plus tibialis anterior allograft tendon has not been studied in detail.

HYPOTHESIS

Outcomes of PCL reconstructions performed with a mixed graft would be superior to those using solely an Achilles tendon allograft in terms of functional knee scores, posterior stability, and the graft appearance.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Fifty-eight patients who underwent isolated single-bundle PCL reconstruction using an arthroscopic trans-septal portal with remnant preservation technique were evaluated. They were divided into group A (mixed tendon; n = 30) and group B (Achilles tendon; n = 28). Knee function was evaluated using the Lysholm knee score, Tegner activity score, and the International Knee Documentation Committee (IKDC) grading scale. Anteroposterior stability was measured using the Telos stress view. Twenty patients (66.7%) from group A and 21 patients (75.0%) from group B underwent hardware removal and a second-look arthroscopic examination.

RESULTS

The Lysholm knee scores in groups A and B increased from a respective average of 43 and 50 preoperatively to 90 and 88 at follow-up. The IKDC grade and Tegner activity scores were also significantly improved in both groups. Stability was improved in both groups, with an average posterior laxity of 3.0 mm (group A) and 3.3 mm (group B) at follow-up (P > .05). However, there were 4 intraoperative complications in group B: 2 bone fractures and 2 graft pullouts during precyclic tensioning. Second-look arthroscopy revealed a partial tear in 8 cases (40%) from group A and 15 cases (71.4%) from group B (P = .03). All of the partial tears were located in the femoral aperture area. Complete synovial coverage was demonstrated in 10 patients (50%) from group A and 5 patients (23.8%) from group B (P = .04). However, clinical outcomes and stability were not affected by the arthroscopic graft appearance.

CONCLUSION

Satisfactory results were obtained for groups A and B in patients who underwent reconstruction for isolated PCL injury. However, 4 intraoperative complications (14.3%) were encountered with use of the Achilles tendon allograft (group B), with a relative higher rate of partial tear and less synovialization in the femoral aperture area.

Loss of PTEN induces microtentacles through PI3K-independent activation of cofilin

Loss of PTEN tumor suppressor enhances metastatic risk in breast cancer, although the underlying mechanisms are poorly defined. We report that homozygous deletion of PTEN in mammary epithelial cells induces tubulin-based microtentacles (McTNs) that facilitate cell reattachment and homotypic aggregation. Treatment with contractility-modulating drugs showed that McTNs in PTEN(-/-) cells are suppressible by controlling the actin cytoskeleton. Because outward microtubule extension is counteracted by actin cortical contraction, increased activity of actin-severing proteins could release constraints on McTN formation in PTEN(-/-) cells. One such actin-severing protein, cofilin, is activated in detached PTEN(-/-) cells that could weaken the actin cortex to promote McTNs. Expression of wild-type cofilin, an activated mutant (S3A), and an inactive mutant (S3E) demonstrated that altering cofilin phosphorylation directly affects McTNs formation. Chemical inhibition of PI3K did not reduce McTNs or inactivate cofilin in PTEN(-/-) cells. Additionally, knock-in expression of the two most common PI3K-activating mutations observed in human cancer patients did not increase McTNs or activate cofilin. PTEN loss and PI3K activation also caused differential activation of the cofilin regulators, LIM-kinase1 (LIMK) and Slingshot-1L (SSH). Furthermore, McTNs were suppressed and cofilin was inactivated by restoration of PTEN in the PTEN(-/-) cells, indicating that both the elevation of McTNs and the activation of cofilin are specific results arising from PTEN loss. These data identify a novel mechanism by which PTEN loss could remodel the cortical actin network to facilitate McTNs that promote tumor cell reattachment and aggregation. Using isogenic MCF-10A PTEN(-/-) and PIK3CA mutants, we have further demonstrated that there are clear differences in activation of cofilin, LIMK and SSH between PTEN loss and PI3K activation, providing a new evidence that these mutations yield distinct cytoskeletal phenotypes, which could have an impact on tumor biology.