Allogenic Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Are More Effective Than Bone Marrow Aspiration Concentrate for Cartilage Regeneration After High Tibial Osteotomy in Medial Unicompartmental Osteoarthritis of Knee.

PURPOSE: The purpose of this study was to compare the outcome of cartilage regeneration between bone marrow aspirate concentrate (BMAC) augmentation and allogeneic human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSCs) transplantation in high tibial osteotomy (HTO) with microfracture (MFX) for medial unicompartmental osteoarthritis (OA) of the knee in the young and active patient. METHODS: Between January 2015 and December 2019, the patients who underwent HTO and arthroscopy with MFX combined with BMAC or allogeneic hUCB-MSCs procedure for medial unicompartmental OA with kissing lesion, which was shown full-thickness cartilage defect (≥ International Cartilage Repair Society [ICRS] grade 3B) in medial femoral cartilage and medial tibial cartilage, were include in this study. Retrospectively we compared clinical outcomes, including Hospital for Special Surgery score, Knee Society Score (KSS) pain and function, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between BMAC and hUCB-MSCs group at minimum of 1-year follow-up. Also, second-look arthroscopy was performed simultaneously with removal of the plate after complete bone union. Cartilage regeneration was graded by the ICRS grading system at second-look arthroscopy. Radiological measurement including hip-knee-ankle (HKA) angle, posterior tibial slope angle, and correction angle were assessed. RESULTS: Of 150 cases that underwent HTO with MFX combined with BMAC or allogeneic hUCB-MSCs procedure for medial unicompartmental OA, 123 cases underwent plate removal and second-look arthroscopy after a minimum of 1 year after the HTO surgery. Seventy-four cases were kissing lesion in medial femoral cartilage and medial tibial cartilage during initial HTO surgery. Finally, the BMAC group composed of 42 cases and hUCB-MSCs group composed of 32 cases were retrospectively identified in patients who had kissing lesions and second-look arthroscopies with a minimum of 1 year of follow-up. At the final follow-up of mean 18.7 months (standard deviation = 4.6 months), clinical outcomes in both groups had improved. However, there were no significant differences between the IKDC, WOMAC, or KSS pain and function scores in the 2 groups (P > .05). At second-look arthroscopy, the ICRS grade was significantly better in the hUCB-MSC group than in the BMAC group in both medial femoral and medial tibial cartilage (P = .001 for both). The average ICRS grade of the BMAC group improved from 3.9 before surgery to 2.8 after surgery. The average ICRS grade of the hUBC-MSC group improved from 3.9 before surgery to 2.0 after surgery. Radiological findings comparing postoperative HKA angle, posterior tibial slope angle, and correction angle showed no significant differences between the groups (P > .05). Therefore it was found that the postoperative correction amount did not affect the postoperative cartilage regeneration results. CONCLUSIONS: We found that the hUCB-MSC procedure was more effective than the BMAC procedure for cartilage regeneration in medial unicompartmental knee OA even though the clinical outcomes improved regardless of which treatment was administered. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Bone marrow aspirate concentration provided better results in cartilage regeneration to microfracture in knee of osteoarthritic patients.

PURPOSE: To determine whether microfracture with bone marrow aspirate concentrate (BMAC) improves functional outcome and cartilage regeneration better than microfracture alone in patients undergoing high tibial osteotomy (HTO) for medial unicompartmental osteoarthritis (OA). METHODS: Among 436 patients treated with HTO for medial unicompartmental OA with varus deformity between 2010 and 2016, clinical outcomes were retrospectively compared between the microfracture alone group (group I, 43 cases) and microfracture with BMAC augmentation group (group II, 48 cases). Of these, 64 patients underwent a second-look arthroscopic assessment. Clinical outcomes were compared based on the Knee Society Score (KSS), International Knee Documentation Committee (IKDC) subjective score, and Western Ontario and McMaster Universities Arthritis Index (WOMAC). Cartilage regeneration was assessed according to Koshino's staging system and the International Cartilage Repair Society (ICRS) Cartilage Repair Assessment (CRA) grading system. RESULTS: At the last follow-up, there were no significant intergroup differences in terms of KSS for pain and function (p > 0.05). Moreover, WOMAC scores were similar between the two groups (p > 0.05). Regarding second-look arthroscopy findings, according to Koshino's staging system, there was no significant intergroup difference in terms of defect coverage (p = 0.187). However, group II showed a significantly better mean CRA score than group I (p = 0.035). CONCLUSION: There were no significant differences in clinical outcomes and cartilage regeneration between the groups. However, the CRA score was significantly higher with BMAC augmentation and microfracture than microfracture alone. Therefore, BMAC augmentation had a synergistic effect for a better cartilage regeneration, although studies with a longer follow-up might help to confirm whether microfracture with BMAC augmentation would ensure better clinical outcomes than microfracture alone for the treatment of knee OA.

Comparison of Clinical and Radiologic Outcomes and Second-Look Arthroscopic Findings After Anterior Cruciate Ligament Reconstruction Using Fixed and Adjustable Loop Cortical Suspension Devices.

PURPOSE: To compare clinical and radiological outcomes, including tunnel widening, and to evaluate graft status by second-look arthroscopy after anterior cruciate ligament (ACL) reconstruction using 2 different femoral cortical suspension devices (fixed and adjustable loop). METHODS: Seventy-nine patients were included for this study. The patients were divided into 2 groups, 41 patients of fixed loop group (EndoButton) and 38 patients of adjustable loop group (TightRope). The Tegner activity, Lysholm knee score, Lachman test, and pivot-shift test were compared between the 2 groups. Anterior stress radiographs and femoral tunnel widening on plain radiographs were also compared. Twenty-seven patients (66%) in the EndoButton group and 21 patients (55%) in the TightRope group underwent the second-look arthroscopy. RESULTS: At the final follow-up, the mean Tegner activity, Lysholm, and International Knee Documentation Committee scores were improved in both groups and there were no statistically significant differences (5.1 ± 1.6 and 5.5 ± 2.1, P = .312; 90.4 ± 7.8 and 91.0 ± 6.5, P = .525; and 87.4 ± 6.7 and 88.7 ± 5.3, P = .127, respectively). There were no statistical significances in the both groups in terms of Lachman test and pivot-shift tests (P = .392, .559) as well as anterior stress radiographs (mean 3.2 ± 1.4 mm and 2.9 ± 1.1 mm, P = .343). Moreover, radiologic measurements comparing femoral tunnel widening at proximal and distal half also showed no significant differences (P = .540 and .412 on anteroposterior view; P = .254 and .437 on lateral view). In the second-look arthroscopy findings for graft tear and synovial coverage, there were no significant differences (P = .784 and .897). CONCLUSIONS: Both fixed loop and adjustable loop devices in ACL reconstruction provided good clinical and radiological outcomes. In patients with both devices, femoral tunnel widening at proximal and distal portion have no significant differences after ACL reconstruction. Moreover, second-look arthroscopy revealed no significant differences in terms of synovial coverage and rupture of the graft. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Mesenchymal Stem Cells Decrease Tunnel Widening of Anterior Cruciate Ligament Reconstruction in Rabbit Model.

BACKGROUND AND OBJECTIVES: The study investigated the effect of mesenchymal stem cells (MSCs) or fibrin glue on tunnel widening after anterior cruciate ligament (ACL) reconstruction compared with biologic free control without any biologic agents in the rabbit model. METHODS AND RESULTS: ACL reconstructions were performed in 18 New Zealand white rabbits. All animals were divided into 3 groups according to the following reconstruction conditions and euthanized 12 weeks postoperatively for radiologic and histologic analyses. Thirty-two knees (control group=10; fibrin group=11; MSCs group=11) were finally evaluated. On micro-CT scan, mean femoral tunnel widening on oblique-sagittal image was 0.7±0.4 mm in the control group, 0.22±0.1 mm in the fibrin group and 0.25±0.1 mm in the MSCs group (p=0.001). Fibrin group and MSCs group showed significant differences compared with control group (p=0.002, 0.002). Mean tibial tunnel widening on oblique-sagittal image was 0.76±0.5 mm, 0.27±0.1 mm and 0.29±0.2 mm in the control, fibrin and MSCs group. Fibrin and MSCs group showed significant differences compared with control group (p=0.017, 0.014). Hounsfield Units (HU) were not significantly different between 3 groups (p＞0.05). Histological analysis revealed that the architecture of graft in the MSCs group featured hypercellularity and compact collagen deposit. CONCLUSION: ACL reconstruction using MSCs seemed decrease tunnel widening in rabbit model. Further study with large animals is required to confirm efficacy on decreasing tunnel widening.

Comparison of the Modified Broström Procedure for Chronic Lateral Ankle Instability With and Without Subfibular Ossicle.

BACKGROUND: Subfibular ossicles are frequently found in patients with chronic lateral ankle instability (CLAI). However, there is a lack of consensus about the optimal surgical treatment for CLAI with subfibular ossicle. PURPOSE: To evaluate the clinical and radiographic outcomes of the modified Broström procedure with subfibular ossicle excision compared with the same procedure for CLAI without subfibular ossicle. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Ninety-six patients (96 ankles) treated with the modified Broström procedure using bone tunnel and suture anchor techniques for CLAI constituted the study cohort. The 96 ankles were divided into 2 groups with and without subfibular ossicles. The ossicle group (42 ankles) and nonossicle group (54 ankles) consisted of patients with a mean age of 26.6 and 30.3 years, respectively, at the time of surgery with a mean follow-up duration of 63.7 and 62.1 months, respectively. Subfibular ossicles were excised in the ossicle group. RESULTS: Mean Karlsson scores improved from 55.2 to 95.3 in the ossicle group and from 56.4 to 94.8 in the nonossicle group at final follow-up. Mean American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores also improved from 63.3 to 95.9 in the ossicle group and from 62.8 to 95.1 in the nonossicle group at final follow-up. Mean talar tilt angles were 14.0° in the ossicle group and 12.2° in the nonossicle group preoperatively and 7.6° and 6.8° at the final follow-up, respectively. Mean anterior talar translations in the ossicle group and nonossicle groups improved from 9.3 and 9.4 mm preoperatively to 5.8 and 5.7 mm at final follow-up, respectively. No significant differences were found between the 2 groups in terms of Karlsson score, AOFAS score, talar tilt angle, and anterior talar translation at final follow-up (P > .05). CONCLUSION: The modified Broström procedure with subfibular ossicle excision provided similarly good clinical and radiographic outcomes compared with the same procedure without subfibular ossicle excision. Accordingly, the study results suggest that these procedures appear to be effective and reliable method for the treatment of CLAI with subfibular ossicle.