Factors Influencing Clinical and MRI Outcomes of Mesenchymal Stem Cell Implantation With Concomitant High Tibial Osteotomy for Varus Knee Osteoarthritis.

BACKGROUND: Cartilage repair procedures using mesenchymal stem cells (MSCs) can provide superior cartilage regeneration in the medial compartment of the knee joint when high tibial osteotomy (HTO) is performed for varus knee osteoarthritis (OA). However, few studies have reported the factors influencing the outcomes of MSC implantation with concomitant HTO. PURPOSE: To investigate the outcomes of MSC implantation with concomitant HTO and to identify the prognostic factors that are associated with the outcomes. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 71 patients (75 knees) were retrospectively evaluated after MSC implantation with concomitant HTO. Clinical and radiological outcomes were evaluated, and magnetic resonance imaging (MRI) was used to assess cartilage regeneration. Statistical analyses were performed to determine the effect of different factors on clinical, radiographic, and MRI outcomes. RESULTS: Clinical and radiographic outcomes improved significantly from preoperatively to final follow-up (P < .001 for all), and overall cartilage regeneration was encouraging. Significant correlations were found between clinical and MRI outcomes. However, radiographic outcomes were not significantly correlated with clinical or MRI outcomes. Patient age and number of MSCs showed significant correlations with clinical and MRI outcomes. On multivariate analyses, patient age and number of MSCs showed high prognostic significance with poor clinical outcomes. CONCLUSION: MSC implantation with concomitant HTO provided feasible cartilage regeneration and satisfactory clinical outcomes for patients with varus knee OA. Patient age and number of MSCs were important factors that influenced the clinical and MRI outcomes of MSC implantation with concomitant HTO for varus knee OA.

Comparative matched-pair cohort analysis of the short-term clinical outcomes of mesenchymal stem cells versus hyaluronic acid treatments through intra-articular injections for knee osteoarthritis.

PURPOSE: Intra-articular injection of hyaluronic acid (HA) has shown promises in reducing pain and improving physical function in knee osteoarthritis (OA). Recently, cell-based therapies using mesenchymal stem cells (MSCs) have emerged as potential treatments. However, few studies have compared the treatment outcomes between MSCs and HA. This study aimed to compare the clinical and radiological outcomes of intra-articular injections of MSCs versus HA in patients with knee OA. METHODS: A cohort of 209 patients with knee OA were retrospectively screened for those who underwent intra-articular injections using MSCs or HA. Thirty MSC-treated patients (MSC group) were pair-matched with thirty HA-treated patients (HA group) based on gender and age. Clinical outcomes were evaluated using the visual analog scale (VAS), International Knee Documentation Committee (IKDC) rating system, and Lysholm scoring system. Radiological evaluation was assessed using the Kellgren-Lawrence (K-L) grading system. RESULTS: MSC treatment yielded consistent significant improvements in VAS, IKDC and Lysholm scores. In the HA group, VAS scores significantly decreased at 1 month, slightly increased at 3 months, and increased significantly from 3 months to 1 year after injection. The IKDC and Lysholm scores improved significantly until 3 months, but gradually worsened thereafter. Significantly greater improvements in VAS (P = 0.041), IKDC (P = 0.014), and Lysholm (P = 0.020) scores were observed in the MSC group compared to those in the HA group at 1-year post-treatment. The K-L grade worsened in a few patients, especially those in the HA group, albeit no significant difference. CONCLUSIONS: MSC group showed better VAS, IKDC, and Lysholm scores at 1-year post-treatment, compared to the HA group, although earlier clinical improvements were superior in the HA group for the initial 3 months. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Mesenchymal Stem Cell Implantation in Knee Osteoarthritis: Midterm Outcomes and Survival Analysis in 467 Patients.

BACKGROUND: A cell-based tissue engineering approach that uses mesenchymal stem cells (MSCs) has addressed the issue of articular cartilage repair in knees with osteoarthritis (OA). PURPOSE: To evaluate the midterm outcomes, analyze the survival rates, and identify the factors affecting the survival rate of MSC implantation to treat knee OA. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We retrospectively evaluated 467 patients (483 knees) who underwent MSC implantation on a fibrin glue scaffold for knee OA with a minimum 5-year follow-up. Clinical outcomes were determined based on the International Knee Documentation Committee (IKDC) and Tegner activity scale results measured preoperatively and during follow-up. Standard radiographs were evaluated using Kellgren-Lawrence grading. Statistical analyses were performed to determine the survival rate and the effect of different factors on the clinical outcomes. RESULTS: The mean IKDC scores (baseline, 39.2 ± 7.2; 1 year, 66.6 ± 9.6; 3 years, 67.2 ± 9.9; 5 years, 66.1 ± 9.7; 9 years, 62.8 ± 8.5) and Tegner scores (baseline, 2.3 ± 1.0; 1 year, 3.4 ± 0.9; 3 years, 3.5 ± 0.9; 5 years, 3.4 ± 0.9; 9 years, 3.2 ± 0.9) were significantly improved until 3 years postoperatively and gradually decreased from 3- to 9-year follow-up (P < .05 for all, except for Tegner score at 5 years vs 1 year [P = .237]). Gradual deterioration of radiological outcomes according to the Kellgren-Lawrence grade was found during follow-up. Survival rates based on either a decrease in IKDC or an advancement of radiographic OA with Kellgren-Lawrence scores were 99.8%, 94.5%, and 74.5% at 5, 7, and 9 years, respectively. Based on multivariate analyses, older age and the presence of bipolar kissing lesion were associated with significantly worse outcomes (P = .002 and .013, respectively), and a larger number of MSCs was associated with significantly better outcomes (P < .001) after MSC implantation. CONCLUSION: MSC implantation provided encouraging outcomes with acceptable duration of symptom relief at midterm follow-up in patients with early knee OA. Patient age, presence of bipolar kissing lesion, and number of MSCs were independent factors associated with failure of MSC implantation.

Implantation of mesenchymal stem cells in combination with allogenic cartilage improves cartilage regeneration and clinical outcomes in patients with concomitant high tibial osteotomy.

PURPOSE: This study aimed to compare the clinical, radiological, and second-look arthroscopic outcomes of implanting mesenchymal stem cells (MSCs) alone and together with allogenic cartilage in patients treated with concomitant high tibial oteotomy (HTO) for varus knee osteoarthritis. METHODS: Eighty patients treated with cartilage repair procedures and concomitant HTO were prospectively randomized into two groups: MSC implantation (MSC group), and MSC implantation with allogenic cartilage (MSC-AC group). Clinical outcomes were evaluated using the Lysholm Score and the Knee Injury and Osteoarthritis Outcome Score (KOOS) at preoperative and every follow-up visit. Radiological outcomes were evaluated by measuring the femorotibial angle and posterior tibial slope. During second-look arthroscopy, cartilage regeneration was evaluated according to the Kanamiya grade. RESULTS: Clinical outcomes at the second-look arthroscopy (mean 12.5 months [MSC group] and 12.4 months [MSC-AC group]) improved significantly in both groups (P < 0.001 for all). Clinical outcomes from the second-look arthroscopy to the final follow-up (mean 27.3 months [MSC group] and 27.8 months [MSC-AC group]) improved further only in the MSC-AC group (P < 0.05 for all). Overall, the Kanamiya grades, which were significantly correlated with clinical outcomes, were significantly higher in the MSC-AC group than in the MSC group. Radiological outcomes at final follow-up revealed improved knee joint alignments relative to preoperative conditions but without significant correlation between clinical outcomes and Kanamiya grade in either group (n.s. for all). CONCLUSION: Implantation of MSCs with allogenic cartilage is superior to implantation of MSCs alone in cartilage regeneration accompanied with better clinical outcomes. LEVEL OF EVIDENCE: Therapeutic study, level II.

Computational analysis of customized cruciate retaining total knee arthroplasty restoration of native knee joint biomechanics.

The purpose of this study was to verify if customized prosthesis better preserves the native knee joint kinematics and provides lower contact stress on the polyethylene (PE) insert owing to the wider bone preservation than that of standard off-the-shelf prosthesis in posterior cruciate-retaining type total knee arthroplasty (TKA). Validated finite element (FE) models for were developed to evaluate the knee joint kinematics and contact stress on the PE insert after TKA with customized and standard off-the-shelf (OTS) prostheses as well as in normal healthy knee through FE analysis under dynamic loading conditions. The contact stresses on the customized prosthesis decreased by 18% and 8% under gait cycle loading conditions, and 24% and 9% under deep-knee-bend loading conditions, in the medial and lateral sides of the PE insert, respectively, compared with the standard OTS prosthesis. The anterior-posterior translation and internal-external (IE) rotation in customized TKA were more similar to native knee joint behaviors compared with standard OTS TKA under gait loading conditions. The difference from normal knee kinematics was lower for femoral rollback and IE rotation in customized TKA than in standard OTS TKA in the deep-knee-bend condition. In general, customized prostheses achieve kinematics that are close to those of the native healthy knee joint and have better contact stresses than standard OTS prostheses in gait and deep-knee-bend loading conditions.

Effect of sodium hyaluronate/carboxymethyl cellulose (Guardix-sol) on retear rate and postoperative stiffness in arthroscopic rotator cuff repair patients: A prospective cohort study.

PURPOSE: Hyaluronate-based anti-adhesive agents are expected to enhance rotator cuff healing; however, their effect on the incidence and extent of postoperative complications such as stiffness and retears has not been investigated. METHODS: From July 2012 to February 2013, 80 patients undergoing arthroscopic rotator cuff repair surgery were prospectively enrolled. Forty patients were assigned to the control group, while the other 40 were assigned to the injection group and received a Guardix-sol injection immediately after surgery. Passive range of motion, pain visual analog scale, and functional score were assessed at 8 weeks, 6 months, and 24 months postoperatively. Gliding motion between the deltoid muscle and the greater tuberosity of the proximal humerus was evaluated using ultrasonography at 2 and 8 weeks postoperatively, and tendon integrity was evaluated using magnetic resonance imaging at 6 months postoperatively. RESULTS: We found no significant difference between the groups regarding gliding motion at 2 weeks postoperatively. However, at 8 weeks, the incidence of poor gliding motion was 2.5% and 15% for the injected patients and control group, respectively, which was statistically significant. At 6 months after surgery, the retear rate between the two groups was not statistically significant. We found no statistically significant difference between the two groups regarding retear rate and clinical score throughout the follow-up period. We noted no complications related to the use of Guardix-sol. CONCLUSIONS: Patients who received the Guardix-sol injection showed improved gliding motion between the deltoid muscle and the greater tuberosity in the early postoperative period.

Supraspinatus muscle occupation ratio predicts rotator cuff reparability.

BACKGROUND: We wished to determine the correlation between supraspinatus muscle occupation ratio and reparability of rotator cuff muscles and that of each occupation ratio with 1-muscle, 2-muscle, and 3-muscle rotator cuff injury. METHODS: We evaluated 170 patients (average age, 62.3 [40-83] years) with complete (type II) or incomplete (type III) rotator cuff repair by arthroscopy. Type II repair was defined as complete repair but less optimal coverage of the entire medial-lateral footprint. Type III repair was defined as incomplete repair; a small portion (<10 mm) of the humeral head is exposed. Patients were divided into 2 groups: 96 and 74 patients who underwent type II and type III repair, respectively. Patients were also categorized into 4 groups: isolated supraspinatus tears, supraspinatus and infraspinatus tears, supraspinatus and subscapularis tears, and tears in all 3 muscles. Supraspinatus muscle atrophy was evaluated by the occupation ratio on the most lateral T1-weighted sagittal oblique view in which the scapular spine contacted the scapular body. The supraspinatus muscle occupation ratio was measured by 2 independent observers. RESULTS: On magnetic resonance imaging, the supraspinatus muscle occupation ratio was significantly different between the completely repaired and incompletely repaired groups. The mean occupation ratio of the completely repaired group (42.39 ± 10.1) was significantly higher than that of the incompletely repaired group (36.64 ± 6.94). The cutoff value of the supraspinatus muscle occupation ratio (complete to incomplete repair) was 41. The supraspinatus muscle occupation ratio significantly decreased as the tear increased (P < .001). CONCLUSION: A supraspinatus muscle occupation ratio of <41 can be the cutoff value for greater tuberosity coverage vs. incomplete coverage. There was a significant correlation between tear pattern and supraspinatus muscle atrophy ratio. The supraspinatus tear group had the lowest degree of muscle atrophy.

Simultaneous multiple anterior cruciate ligament reconstructions using a single Achilles tendon allograft.

This study aimed to evaluate simultaneous multiple anterior cruciate ligament (ACL) reconstructions performed with a single Achilles allograft. After selection of an Achilles allograft with suitable length, the circumference of the isthmus and length of the tendinous portion were measured. The Achilles tendon was divided along its fibers into two or three strips and each strip was looped into a two-strand construct. Fifteen Achilles allografts were used for 31 ACL reconstructions in 30 subjects. The median circumference at the isthmus was 29 mm and the median length of the Achilles tendon 185 mm before and 206 mm after removal of the insertional bone block. The median difference in length before and after removal of the bone block was 19 mm. Achilles allografts with proper length consistently yielded two free tendon grafts suitable for simultaneous multiple ACL reconstruction with good short-term results.