Association of Stability and Size of Unhealed Area With Failure After Internal Fixation for Osteochondritis Dissecans Lesions of the Knee: Radiological Evaluation Using Computed Tomography.

BACKGROUND: Open reduction and internal fixation (ORIF) has been widely performed because the osteochondral component of the osteochondritis dissecans (OCD) lesion is the most suitable for reconstructing the joint structure. PURPOSE: To evaluate radiological healing in terms of reconstructed bony structure after ORIF with bone graft by computed tomography (CT), to identify preoperative prognostic factors for failure, and to determine the cutoff value of radiological healing for risk of failure. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A retrospective cohort study of 42 patients (44 knees) who underwent internal fixation with bone graft for OCD lesions of the knee from 2004 to 2018 was conducted. All patients were evaluated 6 months postoperatively, and if not healed 6 months after surgery, they were evaluated by CT periodically thereafter. Radiological healing was judged according to the following 3 criteria: (1) reossification of the OCD lesion, (2) bony continuity between the OCD lesion and basal floor, and (3) reconstructed bony surface of the femoral condyle reconstructed to match the normal joint. Then, the percentage of the radiological healing area was calculated as the ratio of the healing length to the total lesion length. The nonhealing area was calculated by multiplying the sum of the total nonhealing length. Clinical failure was defined as any definitive reoperation for the same OCD lesion, such as fragment excision, or a cartilage restoration procedure. After 6 months, all eligible patients underwent arthroscopy to check for protrusion of the absorbable pin into the joint; the removal of an absorbable pin protruding into the joint was not considered a failure. RESULTS: Clinical failure was recorded for 4 cases (9.1%). The mean overall percentage of the radiological healing area of OCD 6 months after ORIF with bone graft was 79.5% ± 24.4%, and the mean overall nonhealing area at 6 months was 87.8 ± 107.9 mm2. The percentages of radiological healing area of stable (International Cartilage Regeneration & Joint Preservation Society OCD II) lesions and femoral condylar (lateral femoral condyle + medial femoral condyle) lesions were significantly lower than unstable lesions and femoral groove lesions, respectively (P = .01 and P = .03, respectively). On receiver operating characteristic curve analysis, the cutoff points for predicting a significantly increased risk of failure were 33.9% (sensitivity, 100%; specificity, 100%; area under the curve, 1) for the percentage of radiological healing area and 222.9 mm2 (sensitivity, 95%; specificity, 100%; area under the curve, 0.956) for the nonhealing area 6 months postoperatively. CONCLUSION: A stable lesion and a femoral condylar lesion were the predictors of poor radiological healing on CT images 6 months after ORIF with bone graft. The risk of failure was increased significantly in cases with only approximately one-third of the lesion healed or in cases with large nonhealing areas at 6 months postoperatively.

Five-Year Outcomes After Implantation of a Scaffold-Free Tissue-Engineered Construct Generated From Autologous Synovial Mesenchymal Stromal Cells for Repair of Knee Chondral Lesions.

Background: In an earlier study, a scaffold-free tissue-engineered construct (TEC) derived from autologous synovial membrane mesenchymal stromal cells (MSCs) was developed and demonstrated to be safe and effective for cartilage repair at 2 years postoperatively. Purpose: To investigate clinical outcomes and magnetic resonance imaging (MRI) findings at 5 years after implantation. Study Design: Case series; Level of evidence, 4. Methods: This was an observational first-in-human study limited to 5 patients (age, 28-46 years) with symptomatic knee chondral lesions (size, 1.5-3.0 cm2) on the medial femoral condyle, lateral femoral condyle, or femoral groove. Synovial MSCs were isolated from arthroscopic biopsy specimens and cultured to develop a TEC that matched the lesion size. The TECs were then implanted into chondral defects without fixation and assessed at up to 5 years postoperatively. The patients were clinically evaluated using the visual analog scale for pain, Lysholm score, Tegner score, and Knee injury and Osteoarthritis Outcome Score. An MRI scan evaluation was also performed for morphologic and compositional quality of the repair tissue at both 2 and 5 years of follow-up. Results: All clinical scores were significantly improved from the preoperative evaluation to the 2- and 5-year follow-ups and the results were stable over time. The MRI scan evaluation showed cartilage defects filled with newly generated tissues with good tissue integration to adjacent host cartilage over time. The cartilage thickness and surface smoothness of the repair cartilage were maintained up to 5 years postoperatively. The MOCART (magnetic resonance observation of cartilage repair tissue) 2.0 Knee Scores remained high at 5 years, although the total points decreased slightly. Conclusion: The results highlight the efficacy and feasibility of autologous scaffold-free TEC derived from synovial MSCs for regenerative cartilage repair via a sutureless and simple implantation procedure, showing good clinical outcomes and MRI findings with stable results at midterm follow-up. Further follow-up will be needed to assess the long-term quality of the repair tissue.

Changes in patellar height after anatomical ACL reconstruction with BTB autograft with a focus on patellar tendon removal volume.

BACKGROUND: Although anatomical anterior cruciate ligament reconstruction (ACLR) can provide satisfactory outcomes, little is known about how this procedure impacts patellar height. Since harvesting bone-patellar tendon-bone (BTB) autografts is a potential risk factor for decreased patellar height, we examined changes in patellar height after anatomical ACLR with BTB autograft with a focus on the size of the harvested graft. METHODS: Subjects were 84 patients (49 males, 35 females; mean age, 23 years) who underwent primary anatomical ACLR with central third BTB autograft. Preoperative to postoperative Caton-Deschamps index (CDI) ratio was calculated using lateral knee radiographs before and 6 months after surgery. The length and cross-sectional area (CSA) of the graft were measured intraoperatively, and the CSA of the contralateral patellar tendon was measured by ultrasound 6 months postoperatively. The difference in graft CSA relative to the contralateral tendon CSA, expressed as a percentage (gCSA:ctCSA percentage), was also calculated. RESULTS: Patellar height decreased slightly after surgery (preoperative CDI: 0.856 ± 0.113; postoperative CDI: 0.841 ± 0.113), with a mean difference between preoperative and postoperative CDIs of -0.015 (range: -0.293 to 0.101). Although the CDI of male subjects significantly decreased after surgery (preoperative: 0.852 ± 0.117; postoperative: 0.827 ± 0.115), no significant changes were noted in female subjects (preoperative: 0.862 ± 0.108; postoperative: 0.861 ± 0.108). Graft length and CSA did not significantly impact the CDI ratio (r = -0.138 and r = -0.038, respectively). Moreover, no significant relationship was observed between the gCSA:ctCSA percentage and CDI ratio (r = 0.118). CONCLUSIONS: Although patellar height slightly, but significantly, decreased at 6 months after anatomical ACLR with BTB autograft, it was not affected by the length and CSA of harvested grafts. The decrease in postoperative patellar height was observed only in male subjects, suggesting the potential importance of sex differences in soft tissue healing during the postoperative period.

Rectangular bone-patellar tendon bone grafts reduce early graft failure in chronic ACL-Deficient knees.

BACKGROUND: The aim of this study was to assess early graft failure after anterior cruciate ligament (ACL) reconstruction according to chronicity of ACL deficiency (ACLD) and clarify predisposing factors. METHODS: A total of 731 patients who underwent anatomic ACL reconstruction were divided into 3 groups based on chronicity of ACLD: <6 months (Group 1), 6 months to 2 years (Group 2), and >2 years (Group 3). Types of ACL grafts used included single-bundle hamstring tendon (HT), multiple-bundle HT, and rectangular bone-patellar tendon-bone (BTB) grafts. Preoperatively and immediately postoperatively, lateral radiographs in full extension were taken to examine anterior tibial subluxation (ATS). All ACL grafts were evaluated by MRI at 6 months to identify graft failure. The group with the highest failure rate was further examined to compare possible risk factors between the intact and failure subgroups, followed by multivariate logistic regression analysis to identify predisposing factors. RESULTS: Early graft failure on MRI without any episode of postoperative trauma was observed in 7 (1.4%), 2 (1.8%), and 11 (9.2%) patients in Groups 1, 2, and 3, respectively, with a significantly higher rate in Group 3 (P < 0.001). Of the 119 patients in Group 3, significant differences were observed between intact and failure subgroups with regard to surgical procedure (P = 0.03), chondral lesions (P < 0.01), and preoperative ATS (P < 0.01). Multivariate logistic regression analysis revealed that surgical procedures (odds ratio, 3.8; 95%CI, 1.16-12.59) and preoperative ATS (odd ratio, 2.4; 95%CI, 1.26-4.38) were predisposing factors of early graft failure. CONCLUSION: Patients with ACLD for >2 years experienced early graft failure with an incidence rate of 9.2%. Predisposing factors of early graft failure in these patients included the use of single-bundle HT grafts and preoperative ATS. The use of rectangular BTB grafts resulted in a lower graft failure rate. STUDY DESIGN: Case Series.

Two Uncommon Complications Related to Suture Knots After Meniscal All-Inside Suture Repair: A Case Report.

CASE: A 17-year-old male patient suffered a radial lateral meniscus tear and underwent an arthroscopic all-inside suture repair. After 7 months, the patient experienced catching. Magnetic resonance imaging and computed tomography revealed an intra-articular loose body without calcification, which was removed surgically. The excised specimen was histopathologically confirmed to be a necrotic meniscus fragment with a suture knot. In addition, cartilage damage because of suspected impingement by a residual suture knot was observed. After removing the loose body and knot, the patient's symptoms were relieved, and he returned to sports. CONCLUSION: Suture knot-related complications should be considered while performing meniscal repairs.

The Wound Dressing Influenced Effectiveness of Cryotherapy After Anterior Cruciate Ligament Reconstruction: Case-Control Study Comparing Gauze Versus Film Dressing.

Purpose: To compare the clinical effectiveness of cryotherapy after anterior cruciate ligament reconstruction using 2 different wound dressings, conventional postoperative gauze dressings and polyurethane semipermeable transparent film dressings. Methods: In total, 60 patients who had undergone arthroscopic anterior cruciate ligament reconstruction with an autogenous patellar tendon were assigned to 2 groups. The surgical wound was covered with 5 sheets of gauze with an elastic bandage (control group) in 30 patients and film dressing was used (film group) in the remaining 30 patients. Silicone drainage catheters were inserted at the intercondylar notch, beside the distal outlet of the tibial tunnel for 2 days. After 1 hour of cooling using the device, the knee was chilled with an ice bag every 2 hours until the next morning. The severity of pain was evaluated by the number of times an analgesic, 50 mg of diclofenac sodium suppositories, had to be administered in the 24 hours after surgery. The amount of drainage during the following 2 days, the range of motion at 21 days, the change of hemoglobin concentration at 1 and 7 days, and C-reactive protein (CRP) at 1 and 7 days were examined. Results: The number of patients who used an analgesic was 18 in the control group and 7 in the film group (P = .003). The amount of drainage was 165.2 ± 72.9 mL in the control group and 289.7 ± 77.6 mL in the film group (P < .001). The postoperative CRP value was 0.77 ± 0.65 mg/dL at 1 day in the control group and 0.39 ± 0.42 mg/dL in the film group (P = .009). No statistical difference was seen for hemoglobin concentration at 1 or 7 days, CRP at 7 days or range of motion at 21 days. Conclusions: In this study, we found that film dressing enhanced the effect of cryotherapy with respect to pain control, wound drainage, and inflammation immediately after surgery compared with traditional gauze dressing with elastic wrap. Level of Evidence: III, case-control study.

The lateral meniscal extrusion after repair with concomitant anterior cruciate ligament reconstruction at a mean follow-up of 3.5 years.

BACKGROUND: A meniscal repair is often performed on radial/flap or longitudinal tears of the lateral meniscus (LM) combined with anterior cruciate ligament reconstruction (ACLR). However, it is unknown if meniscal extrusion changes over time after repair. This study evaluated whether meniscal extrusion of the LM is maintained after repair or progresses with time using magnetic resonance imaging (MRI). METHODS: Among 574 patients who underwent primary anatomic ACLR, 123 patients followed up for more than 2 years were retrospectively analyzed. Forty patients with concomitant radial/flap tears of the LM (group R), 43 with longitudinal LM tears (group L), and 40 with intact LM (group C, matched-control group) were included. Clinical findings (pain, range of motion, swelling, and anterior laxity), lateral joint space on radiograph, and meniscal extrusion on MRI were assessed. Lateral/posterior meniscal extrusions were examined preoperatively, within 3 weeks after surgery, and at the final follow-up, and the absolute values and relative values (the preoperative values as baseline) were assessed respectively. RESULTS: There were no significant differences in the clinical and roentgenographic findings among the groups. No difference was observed in the relative values within 3 weeks after surgery among three groups, although the absolute values were larger in the repaired groups than in group C. At the final follow-up, however, the lateral extrusion in group L had progressed significantly, compared with that in group C (P = 0.033), while no significant difference was detected in the lateral extrusion between groups R and C (P = 0.177). The posterior extrusion in groups R and L had progressed significantly compared with that in group C (P < 0.001). CONCLUSIONS: LM extrusion could not be improved even immediately after meniscal repair, and it progressed laterally and posteriorly for more than 2 years after surgery.

Posterior Root Avulsion Fracture of the Medial Meniscus in a Skeletally Immature Child: A Case Report.

CASE: We describe a rare case of posterior root avulsion fracture of the medial meniscus in an 11-year-old boy. Previous reports have demonstrated delayed diagnosis, but in this case, multiplanar computed tomography (CT) combined with magnetic resonance imaging (MRI) enabled early diagnosis and treatment. Gradual ossification was observed after arthroscopic suture fixation, and meniscal extrusion did not progress. He returned to sports without any symptoms and showed no degenerative changes at 2.5 years postoperatively. CONCLUSION: This is the first case report of early diagnosis and time-course analysis of a rare avulsion fracture, emphasizing the usefulness of CT combined with MRI.

Outcomes More Than 2 Years After Meniscal Repair for Longitudinal Tears of the Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Meniscal function after repair of longitudinal tears of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated. PURPOSE: To evaluate not only the clinical outcomes and radiographic findings of patients who underwent repair of longitudinal tears of the LM combined with ACLR but also the healing status of the repaired meniscus and changes in chondral status with second-look arthroscopy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Among 548 patients who underwent primary anatomic ACLR at our institution between 2010 and 2017, 39 who had concomitant longitudinal tears of the LM and underwent repair were studied. During follow-up for more than 2 years, all patients were evaluated clinically (pain, range of motion, swelling, and knee instability) and with imaging (plain radiograph and magnetic resonance imaging [MRI]), and compared with a matched control group (based on age, sex, body mass index, and follow-up period) without any concomitant injuries who underwent ACLR. Measurements on MRI were recorded preoperatively, immediately after surgery, and at final follow-up, and the change in the values over time was assessed. Of the 39 patients in each group, 24 were assessed by second-look arthroscopy with hardware removal 2 years postoperatively. RESULTS: The mean follow-up times of the study and control group were at a mean of 42.4 and 45.4 months, respectively. There were no significant differences in clinical findings, lateral joint space narrowing on radiographs, and chondral status at the lateral compartment between groups, whereas lateral and posterior meniscal extrusion on MRI progressed significantly in the study group (0.43 ± 1.0 mm vs -0.29 ± 1.1 mm, P = .003; 1.9 ± 1.9 mm vs 0.14 ± 1.1 mm, P < .0001, respectively). Second-look arthroscopy revealed complete healing in 12 patients (50%), partial healing in 9 (37.5%), and failure in 3 (12.5%) in the study group, and no new tear in the control group. CONCLUSION: The clinical and imaging outcomes after repair of longitudinal tears of the LM combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at 42 months postoperatively, although meniscal extrusion showed progression on coronal/sagittal MRI. Based on the MRI findings and the result that only half of patients achieved complete healing, meniscal function could not be fully restored even after repair. Although degenerative changes were not apparent, longer-term follow-up is needed.

Chronological changes in cross-sectional area of the bone-patellar tendon-bone autograft after anatomic rectangular tunnel ACL reconstruction.

PURPOSE: The purpose of this study was to evaluate the change in cross-sectional area (CSA) of bone-patellar tendon-bone (BTB) autografts up to 5 years after the anatomic rectangular tunnel (ART) anterior cruciate ligament reconstruction (ACLR). The changing pattern in CSA might be a potential indicator of the graft remodeling process. METHODS: Ninety-six (62 males, 34 females, mean age 27.0 years) patients were enrolled in this study with a total of 220 MRI scans after ART BTB ACLR to evaluate the CSA of the ACL autografts. The patients with first time unilateral ACLR that consented to undergo MRI evaluations at postoperative periods were included in this study. Intraoperatively, the CSA of the graft was measured directly using a custom-made area micrometer at the midpoint of the graft. Postoperatively, using an oblique axial slice MRI that was perpendicular to the long axis of the graft, the CSA of the graft was measured with digital radiology viewing program "SYNAPSE" at the midpoint of the graft. The postoperative MRI scans were classified into seven groups according to the period from ACLR to MRI evaluation: Group 0-2 months (m.), Group 3-6 m., Group 7-12 m., Group 1-2 years (y.), Group 2-3 y., Group 3-4 y., and Group 4 y.-. The percent increase of the CSA was calculated by dividing the postoperative CSA by the intraoperative CSA. RESULTS: The postoperative CSA was significantly larger than the intraoperative CSA in each group, with the exception of Group 0-2 m. The mean percent increase of the CSA in Group 0-2 m., 3-6 m., 7-12 m., 1-2 y., 2-3 y., 3-4 y., 4 y.- was 101.8 ± 18.2, 188.9 ± 27.4, 190.9 ± 43.7, 183.3 ± 28.9, 175.2 ± 27.9, 163.9 ± 19.8, 164.5 ± 25.4% respectively. The percent increase in Group 3-6 m., 7-12 m., 1-2 y., 2-3 y., 3-4 y., and 4 y.- was significantly greater than that in Group 0-2 m. CONCLUSIONS: The CSA of the BTB autografts after the ART BTB ACLR increases rapidly by 3-6 months after ACLR, reached a maximum value of 190% at around 1 year, decreases gradually after that, and reaches a plateau at around 3 years. The current study might help clinicians to estimate an individual BTB autograft's remodeling stages when considering returning patients to sports. LEVEL OF EVIDENCE: IV.

Promoting Effect of Basic Fibroblast Growth Factor in Synovial Mesenchymal Stem Cell-Based Cartilage Regeneration.

Synovial mesenchymal stem cell (SMSC) is the promising cell source of cartilage regeneration but has several issues to overcome such as limited cell proliferation and heterogeneity of cartilage regeneration ability. Previous reports demonstrated that basic fibroblast growth factor (bFGF) can promote proliferation and cartilage differentiation potential of MSCs in vitro, although no reports show its beneficial effect in vivo. The purpose of this study is to investigate the promoting effect of bFGF on cartilage regeneration using human SMSC in vivo. SMSCs were cultured with or without bFGF in a growth medium, and 2 × 105 cells were aggregated to form a synovial pellet. Synovial pellets were implanted into osteochondral defects induced in the femoral trochlea of severe combined immunodeficient mice, and histological evaluation was performed after eight weeks. The presence of implanted SMSCs was confirmed by the observation of human vimentin immunostaining-positive cells. Interestingly, broad lacunae structures and cartilage substrate stained by Safranin-O were observed only in the bFGF (+) group. The bFGF (+) group had significantly higher O'Driscoll scores in the cartilage repair than the bFGF (-) group. The addition of bFGF to SMSC growth culture may be a useful treatment option to promote cartilage regeneration in vivo.

Outcomes More Than 2 Years After Meniscal Repair for Radial/Flap Tears of the Posterior Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Meniscal function after repair of radial/flap tears of the posterior horn of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated. PURPOSE: To evaluate not only the clinical and radiographic outcomes of patients with repair of radial/flap tears of the posterior LM with ACLR but also the healing status of the repaired meniscus and changes of chondral status with second-look arthroscopy. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From January 2008 to April 2016, 41 patients of a consecutive series of 505 primary anatomic ACLR cases had a concomitant radial/flap tear of the posterior horn of the LM and underwent side-to-side repair with an inside-out or all-inside technique. All patients were followed for >2 years, evaluated clinically and radiologically (radiograph and magnetic resonance imaging [MRI]), and compared with a control group without any concomitant injuries that underwent ACLR. Of the 41 patients, 30 were assessed by second-look arthroscopy 2 years postoperatively. RESULTS: The mean follow-up times of the study and control groups were 3.4 and 3.9 years, respectively. The study group showed no significant differences in clinical findings, lateral joint space narrowing on radiograph, and coronal extrusion on MRI as compared with the control group, whereas sagittal extrusion on MRI progressed significantly in the study group (1.2 ± 1.5 mm vs 0.32 ± 1.0 mm, P < .001). Eighteen patients (60%) obtained complete healing; 9 (30%) showed partial healing; and 3 (10%) failed to heal on second-look arthroscopy. Changes of chondral status in the femoral condyle showed no significant difference between the groups (P = .29). However, chondral status of the lateral tibial plateau worsened significantly in the study group (P = .0011). CONCLUSION: The clinical and radiographic outcomes after repair of radial/flap tears of the posterior horn of the LM as combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at a mean postoperative follow-up of 3.4 years, except for sagittal extrusion on MRI. Chondral lesions of the lateral tibial plateau deteriorated regardless of meniscal healing at 2 years postoperatively. Surgeons should keep in mind that chondral injuries might progress over the midterm.

Autologous Osteochondral Transplantation in Full-thickness Patella Chondral Lesion: A Case Series.

PURPOSE: Autologous osteochondral transplantation (AOT) in the focal cartilage lesion of the patella has been reported with less successful results compared with other sites. The purposes were to investigate the clinical outcomes of AOT for focal patellar chondral lesion without patellofemoral instability. METHODS: Between 2001 and 2007, six patients (five males and one female) with a focal patellar cartilage lesion without patellofemoral malalignment and instability were treated with AOT. The mean age was 38 (27-51) years. Intraoperatively, the size and location of lesion were assessed by international cartilage repair society classification. Lysholm score was investigated preoperatively, at 6 months, 1- and 2-year, and final follow-up. Mean follow-up period was 51 months (24-101). Transplanted grafts were evaluated by magnetic resonance imaging (MRI) and second-look arthroscopy. RESULTS: The mean size was 133mm2(78-225). All six cases improved at final follow-up (Lysholm score 79-100). Although immediate pain relief obtained in four cases, severe pain was persistent in remaining two cases during the 1styear and gradually relieved by 2 years following surgery. The size of these two cases was significantly larger (over 170 mm2) than that of four cases (100 mm2 in average) (P<0.05), and their locations were apart from center of the patella inspite of four cases localized centrally (P<0.05). Repaired cartilage did not show any difference by MRI and arthroscopically. CONCLUSION: AOT in focal patellar chondral lesions without patellofemoral malalignment showed excellent results. In cases of large off-centeredlesions, however, it took longer for pain relief following AOT.

Discoid lateral meniscal repair without saucerization for adolescents with peripheral longitudinal tear.

Recently, successful clinical outcomes for symptomatic discoid lateral meniscus (DLM) have been reported following partial meniscectomy (saucerization) with repair. In contrast, some studies using radiography and magnetic resonance imaging (MRI) have suggested that function of load transmission might not be appropriately maintained after saucerization with repair. Therefore, in pursuit to uphold load transmission after surgery for DLM, this study tried to preserve the DLM shape to keep the original DLM function. Discoid lateral meniscus repair without saucerization was indicated, with strict criteria, for those who had a painful peripheral longitudinal tear with purely intact body caused after a single traumatic incidence. The repair was performed without saucerization for four adolescents (two males, two females; mean age 16.2 years; three complete types of DLM, and one incomplete type of DLM). Postoperatively, the following were evaluated with radiography and MRI at six, 12, and 24 months after surgery: clinical outcomes, degenerative changes, and morphology of repaired DLM. They all showed good clinical outcomes. Furthermore, no degeneration, deformation, nor extrusion was observed at the two-year follow-up after surgery. For limited cases of DLM, as mentioned above, DLM repair without saucerization can be one treatment option.

Tibial insertion of the anterior cruciate ligament and anterior horn of the lateral meniscus share the lateral slope of the medial intercondylar ridge: A computed tomography study in a young, healthy population.

BACKGROUND: The central intercondylar ridge (CIR) is an anatomical bony landmark that bisects the slope of the medial intercondylar ridge (MIR) between the tibial insertion of the anterior cruciate ligament (ACL) and anterior horn of lateral meniscus (AHLM) and was recently revealed by computed tomography (CT) evaluation corresponding to histologic slices of cadaveric knees. The purpose of this study was to clarify the shape and size of ACL and AHLM tibial insertion in young, healthy knees using the new bony landmark (CIR) and previously reported landmarks. METHODS: The contralateral healthy knees in 34 ACL-reconstructed patients (18 male patients, 16 female patients, mean age: 24.0 years) were scanned by CT. In the reconstructed coronal/sagittal images, bony landmarks of ACL (anterior: anterior ridge, posterior: blood vessel in tubercle fossa, medial: MIR, lateral: CIR) and AHLM (medial: CIR, lateral: bottom of the slope) were plotted for evaluation. The length of sagittal slices and the width in five coronal slices of the insertion were measured. RESULTS: The ACL insertion consistently showed a boot-like-shape adjacent to the square shape of AHLM on three-dimensional imaging. The mean ACL sagittal length was 14.5 ±â€¯1.9 mm, while the mean ACL widths (in mm) from anterior to posterior were 12.7 ±â€¯2.7, 8.1 ±â€¯1.9, 7.9 ±â€¯2.0, 7.5 ±â€¯1.5, and 7.2 ±â€¯1.6, which was highly correlated with the tibial plateau size. CONCLUSIONS: The boot-like-shape of the ACL tibial footprint insertion shared the slope of MIR with the rectangular shape of AHLM in young, healthy knees. This study may provide useful information for safe tibial tunnel creation at the time of ACL reconstruction.

Significant anterior enlargement of femoral tunnel aperture after hamstring ACL reconstruction, compared to bone-patellar tendon-bone graft.

PURPOSE: This study aimed to retrospectively compare the enlargement and migration of the femoral tunnel aperture after anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction with a bone-patella tendon-bone (BTB) or hamstring tendon (HT) graft using three-dimensional (3-D) computer models. METHODS: Thirty-two patients who underwent ACL reconstruction and postoperative computed tomography (CT) at 3 weeks and 6 months were included in this study. Of these, 20 patients underwent ACL reconstruction with a BTB graft (BTBR group), and the remaining 12 with an HT graft (HTR group). The area of the femoral tunnel aperture was extracted and measured using a 3-D computer model generated from CT images. Changes in the area and migration direction of the femoral tunnel aperture during this period were compared between the two groups. RESULTS: In the HTR group, the area of the femoral tunnel aperture was significantly increased at 6 months compared to 3 weeks postoperatively (P < 0.05). The average area of the femoral tunnel aperture at 6 months postoperatively was larger by 16.0 ± 12.4% in the BTBR group and 41.9 ± 22.2% in the HTR group, relative to that measured at 3 weeks postoperatively (P < 0.05). The femoral tunnel aperture migrated in the anteroinferior direction in the HTR group, and only in the inferior direction in the BTBR group. CONCLUSIONS: The femoral tunnel aperture in the HTR group was significantly more enlarged and more anteriorly located at 6 months after ACL reconstruction, compared to the BTBR group. LEVEL OF EVIDENCE: IV.

Arthroscopic minimum saucerization and inferior-leaf meniscectomy for a horizontal tear of a complete discoid lateral meniscus: Report of two cases.

INTRODUCTION: Treatment of a horizontal tear of a complete discoid lateral meniscus (DLM) is still controversial. Preserving peripheral rim as a normal shape of the meniscus with single-leaf resection is a conventional treatment, however meniscal function could not be fully restored. PRESENTATION OF CASE: A 28-year old woman and a 34-year old woman experienced knee pain and had restricted knee extension. MRI showed horizontal tears of complete DLM in both patients. Arthroscopic minimum saucerization preserving more than 10 mm peripheral rim and inferior-leaf meniscectomy was performed. Two years after the surgery, the patient had no pain and no restriction of ROM. MRI showed the remaining superior-leaf maintained about half its width and no progression of coronal/sagittal extrusion. DISCUSSION AND CONCLUSION: As resecting more meniscal tissue has been considered to be a cause of degeneration or extrusion of the meniscus, arthroscopic minimum saucerization, preserving more meniscal tissue than standard saucerization, and inferior-leaf meniscectomy can be an alternative treatment option of horizontal tears of complete DLM with satisfying clinical and radiological results.

First-in-Human Pilot Study of Implantation of a Scaffold-Free Tissue-Engineered Construct Generated From Autologous Synovial Mesenchymal Stem Cells for Repair of Knee Chondral Lesions.

BACKGROUND: Articular cartilage has limited healing capacity, owing in part to poor vascularity and innervation. Once injured, it cannot be repaired, typically leading to high risk for developing osteoarthritis. Thus, cell-based and/or tissue-engineered approaches have been investigated; however, no approach has yet achieved safety and regenerative repair capacity via a simple implantation procedure. PURPOSE: To assess the safety and efficacy of using a scaffold-free tissue-engineered construct (TEC) derived from autologous synovial membrane mesenchymal stem cells (MSCs) for effective cartilage repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Five patients with symptomatic knee chondral lesions (1.5-3.0 cm2) on the medial femoral condyle, lateral femoral condyle, or femoral groove were included. Synovial MSCs were isolated from arthroscopic biopsy specimens and cultured to develop a TEC that matched the lesion size. The TECs were then implanted into chondral defects without fixation and assessed up to 24 months postoperatively. The primary outcome was the safety of the procedure. Secondary outcomes were self-assessed clinical scores, arthroscopy, tissue biopsy, and magnetic resonance image-based estimation of morphologic and compositional quality of the repair tissue. RESULTS: No adverse events were recorded, and self-assessed clinical scores for pain, symptoms, activities of daily living, sports activity, and quality of life were significantly improved at 24 months after surgery. Secure defect filling was confirmed by second-look arthroscopy and magnetic resonance imaging in all cases. Histology of biopsy specimens indicated repair tissue approaching the composition and structure of hyaline cartilage. CONCLUSION: Autologous scaffold-free TEC derived from synovial MSCs may be used for regenerative cartilage repair via a sutureless and simple implantation procedure. Registration: 000008266 (UMIN Clinical Trials Registry number).