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.

[Surgical Explantation of a Bioprosthesis Nine Months After Transcatheter Aortic Valve Implantation].

CASE: 82-year-old female. In October 2020, the patient underwent transcatheter aortic valve implantation( TAVI)[Evolut PRO R 23 mm] via left subclavian artery approach for severe aortic valve stenosis. The patient was discharged home without any issues. However, nine months after surgery, the patient was hospitalized at another hospital for a right upper arm fracture and developed a fever. The patient was transferred to our hospital and was diagnosed with Enterococcal bacteremia while receiving antibiotic treatment. Echocardiography revealed leaflet thickening and cord-like structure on the artificial valve, and a diagnosis of prosthetic valve endocarditis (PVE) was made. The patient then underwent surgical removal of the valve. The patient had a good postoperative course and completed 4 weeks of antibiotic treatment before being transferred back to the referring hospital 31 days after surgery. TAVI made unprecendented revolution in the treatment of aortic valve stenosis. TAVI is often used for elderly patients with comorbidities because of high perioperative risk is for surgical aortic valve replacement. Although TAVI is widely promoted for its benefits, it is not without limitations. In cases with more than one year of follow-up, there are many complications and the risk of surgery is high. There have been few reports of cases from Japan requiring surgical removal of TAVI valve. In this case, PVE was diagnosed nine months after TAVI and the patient had a good outcome.

Posterior Ankle Impingement Caused by Hyaline-Like Cartilage Generation in Ballet Dancers-A Report of 2 Cases.

Posterior ankle impingement syndrome is mainly seen in ballet dancers and frequently associated with specific movements in ballet such as pointe and demi pointe in which the whole-body weight is applied to the maximally plantar flexed ankle. We performed arthroscopic debridement for 2 dedicated ballet dancers on the intervening soft tissue causing posterior ankle impingement syndrome (PAIS). In both cases, T2-weighted magnetic resonance imaging (MRI) revealed low-signal intensity of meniscus-like soft tissue without abnormal osseous findings, connecting from the posterior side of the talus to Kager's fat pad. To examine the intervening soft tissue in detail, we performed histological evaluation by hematoxylin and eosin staining, Safranin O fast green staining, and immunohistochemistry for type I collagen and type II collagen. Hematoxylin and eosin staining showed that there was cartilage-like tissue including chondrocyte-like cells in contact with fibrous tissue. The extracellular matrix in the cartilage zone was consistently stained by Safranin O staining and type II collagen without any staining with type I collagen. These findings suggested that the meniscus-like soft tissue appearing as low-signal intensity on MRI at the posterior side of talus included hyaline-like cartilage. To the extent of our knowledge, these were rare cases of hyaline-like cartilage generation causing PAIS in ballet dancers, which might be associated with ballet specific movements resulting in chondrogenesis.

Quick and simple test to evaluate severity of acute lateral ankle sprain.

BACKGROUND/OBJECTIVE: For early return to sports after a lateral ankle sprain (LAS) and recurrence prevention, effective rehabilitation and gradual return to sports should be initiated while predicting the return time based on the appropriate severity evaluation immediately after injury. However, since severity evaluations performed in previous studies required large space and stairs and involved high-revel activity, their use as a test and index to evaluate severity after LAS was not appropriate considering convenience and risk of re-injury. Therefore, a quick and simple test was developed to evaluate the severity of acute LAS. This study aimed to verify the association between ankle function for severity evaluation and anterior talofibular ligament (ATFL) injury type by ultrasonography and to clarify the usefulness for acute LAS severity evaluation of the single-leg loading (SLL) test. METHODS: In total, 50 patients (34 men, 16 women) out of 58 patients who visited our sports clinic within 3 days after acute LAS and who conformed to the study criteria were included in this study. During the first visit, SLL test and objective/subjective ankle joint evaluation were performed. The SLL test consists of single-leg standing, single-leg heel raising and single-leg hopping, and patients were classified into four levels from 1 to 4 according to results. In addition, ultrasonographic evaluation was performed within 1 week after the first visit to evaluate the type of ATFL injury. Type I was defined as intact ATFL, Type II as swollen ATFL with an almost intact fibrillar pattern and Type III as ATFL appearing swollen with a disrupted fibrillar pattern. The relationship between the SLL test and each evaluation item was investigated using Spearman's correlation coefficient. RESULTS: As a result of the SLL test, 15 patients had Level 1 (30%), 19 Level 2 (38%), 5 Level 3 (10%) and 11 Level 4 (22%). With regard to correlation coefficients of the SLL test, Japanese Society for Surgery of the Foot ankle/hindfoot scale and sports activity were rs = 0.71 (p < 0.001) and rs = 0.66 (p < 0.001), respectively, showing a significant positive correlation. SLL test and the type of ATFL injury also showed a significant negative correlation (rs = -0.58, p < 0.001). CONCLUSIONS: The SLL test was a simple and useful test that can be used as an index to evaluate the severity of acute LAS.

Abrasion arthroplasty promotes improvement of degenerated femoral trochlear cartilage after medial open wedge high tibial osteotomy.

OBJECTIVES: Several studies have reported negative effects of open wedge high tibial osteotomy (OWHTO) on patellofemoral joints with cartilage degeneration and recommended performing other procedures. However, if chondral resurfacing surgery could promote improvement of cartilage degeneration in the patellofemoral joint, OWHTO would be an acceptable option. The purposes of this study were to arthroscopically evaluate the femoral trochlear articular cartilage after abrasion arthroplasty combined with OWHTO and to investigate the factors promoting improvement of that cartilage. METHODS: The present study cohort comprised 18 knees of 18 patients with varus osteoarthritis of the knee who had (1) International Cartilage Repair Society (ICRS) grade 4 femoral trochlear chondral lesions at the time of OWHTO; (2) undergone abrasion arthroplasty of the femoral trochlear cartilage in combination with OWHTO; (3) undergone second-look arthroscopy; and (4) been followed up for more than 2 years. Cartilage status was arthroscopically graded at the time of OWHTO and second-look arthroscopy. Patients were allocated to two groups according to the status of the femoral trochlear cartilage at the time of second-look arthroscopy: the improved group comprised patients with an ICRS grade of less than 3, and the not improved group comprised those with an ICRS grade of 4. Clinical outcomes, expressed as Knee Injury and Osteoarthritis Outcome Score (symptoms, pain, activities of daily living, function in sports/recreation and quality of life) and selected radiographic variables were compared between the two groups. RESULTS: There were 11 (61%) knees in the improved group and 7 (39%) in the not improved group. A comparison of radiographic variables between the two groups revealed that neither limb alignment nor patellar height affected cartilage changes. The two groups had similar results on the symptoms, pain, sports/recreation and activities of daily living subscales of the Knee Injury and Osteoarthritis Outcome Score. However, the quality of life subscale significantly differed between the two groups (p=0.025). CONCLUSION: Degenerated femoral trochlear cartilage can improve after combined abrasion arthroplasty and OWHTO. A comparison of clinical outcomes between the improved and not improved groups revealed that neither radiographic variables nor clinical symptoms, including pain, affected cartilage changes at short-term follow-up. LEVEL OF EVIDENCE: Case series, level V.

Second-look arthroscopy after anatomic anterior cruciate ligament reconstruction: Bone-patellar tendon-bone versus hamstring tendon graft.

PURPOSE: The purpose of this study was to compare the morphological and clinical outcomes between anatomic rectangular tunnel (ART) ACL reconstruction with a BTB graft and anatomic triple-bundle (ATB) ACL reconstruction with hamstring tendon (HST) grafts. METHODS: The anatomic ACL reconstructions were performed on 467 patients; 233 patients with ART technique and 234 with ATB procedure. ART procedure was predominantly indicated for athletes with higher motivation to return to sports and aggressiveness for muscle training. A total of 113 patients, with a mean age of 20.7 years, had consented to undergo second-look arthroscopy. The average time from ACL reconstruction to the second-look was 10.0 months. This study included 56 ART techniques and 57 ATB procedures. The grafts underwent meticulous probing, and were evaluated based on tension, graft damage, and synovial coverage. Moreover, the femoral tunnel aperture was also observed in detail to assess the space between the femoral tunnel and the graft. As clinical evaluation, knee effusion, range of motion, Lachman test, pivot shift test, KT side-to-side difference, and Lysholm score were assessed. RESULTS: There was no significant difference in graft tension between two procedures, while HST graft in ATB procedure had more cases with graft damage (p = 0.05). Good synovial coverage was found in 98% in ART procedure and 70% in ATB procedure, showing a significant difference (P < 0.001). At femoral tunnel aperture, there were no cases with the space around BTB graft, while 33% showed the space around HST graft, again showing a significant difference (P < 0.001). There were no significant differences in clinical outcomes. CONCLUSION: BTB graft with the ART procedure was superior to HST graft with the ATB procedure in morphology at second-look arthroscopy, while there was no significant difference in clinical outcomes between two procedures.

Ultrasonographic Evaluation of the Early Healing Process After Achilles Tendon Repair.

BACKGROUND: Little is known about early healing of repaired Achilles tendons on imaging, particularly up to 6 months postoperatively, when patients generally return to participation in sports. PURPOSE: To examine changes in repaired Achilles tendon healing with ultrasonography for up to 12 months after surgery. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Ultrasonographic images of 26 ruptured Achilles tendons were analyzed at 1, 2, 3, 4, 6, and 12 months after primary repair. The cross-sectional areas (CSAs) and intratendinous morphology of the repaired tendons were evaluated using the authors' own grading system (tendon repair scores), which assessed the anechoic tendon defect area, intratendinous hyperechoic area, continuity of intratendinous fibrillar appearance, and paratendinous edema. RESULTS: The mean ratios (%) of the CSA for the affected versus unaffected side of repaired Achilles tendons gradually increased postoperatively, reached a maximum (632%) at 6 months, and then decreased at 12 months. The mean tendon repair scores increased over time and reached a plateau at 6 months. CONCLUSION: Ultrasonography is useful to observe the intratendinous morphology of repaired Achilles tendons and to provide useful information for patients who wish to return to sports. Clinical parameters such as strength, functional performance, and quality of healed repaired tendons should also be assessed before allowing patients to return to sports.

Contact area between femoral tunnel and interference screw in anatomic rectangular tunnel ACL reconstruction: a comparison of outside-in and trans-portal inside-out techniques.

PURPOSE: The purpose of this study was to compare the femoral tunnel length, the femoral graft bending angle at the femoral tunnel aperture, and the contact area between the femoral tunnel wall and an interference screw used for fixation in anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction (ART ACLR). METHODS: The study included 149 patients with primary ACL injury who underwent ART ACLR. Preoperatively, flexion angle of the index knee was checked under general anaesthesia. Those of less than 130° of passive flexion were assigned to the outside-in (OI) technique (78 patients), while the others to the trans-portal inside-out (TP) technique (71 patients). The patients underwent computed tomography with multiplanar reconstruction at 3-5 weeks post-operatively. Femoral tunnel length, graft bending angle, and contact ratio between the IFS and femoral tunnel were assessed. P < 0.05 was considered statistically significant. RESULTS: The femoral tunnel length in the OI technique was significantly longer than that in the TP technique (P < 0.001). The femoral graft bending angle in the OI technique was significantly more acute than that in the TP technique (P < 0.001). The contact ratio in the OI technique was significantly larger than that in the TP technique at every point in the femoral tunnel (P < 0.001). CONCLUSIONS: The OI technique resulted in a more acute femoral graft bending angle, longer mean femoral tunnel length, and larger contact ratio than the TP technique after ART ACLR. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Sox9 reprogrammed dermal fibroblasts undergo hypertrophic differentiation in vitro and trigger endochondral ossification in vivo.

Strategies for bone regeneration are undergoing a paradigm shift, moving away from the replication of end-stage bone tissue and instead aiming to recapture the initial events of fracture repair. Although this is known to resemble endochondral bone formation, chondrogenic cell types with favorable proliferative and hypertrophic differentiation properties are lacking. Recent advances in cellular reprogramming have allowed the creation of alternative cell populations with specific properties through the forced expression of transcription factors. Herein, we investigated the in vitro hypertrophic differentiation and in vivo tissue formation capacity of induced chondrogenic cells (iChon cells) obtained through direct reprogramming. In vitro hypertrophic differentiation was detected in iChon cells that contained a doxycycline-inducible expression system for Klf4, cMyc, and Sox9. Furthermore, endochondral bone formation was detected after implantation in nude mice. The bone tissue was derived entirely from host origin, whereas cartilage tissue contained cells from both host and donor. The results obtained highlight the promise of cellular reprogramming for the creation of functional skeletal cells that can be used for novel bone healing strategies.

Induction of chondrogenic cells from dermal fibroblast culture by defined factors does not involve a pluripotent state.

There is a significant need for cell sources for cartilage regenerative medicine. It has been reported that the combined transduction of two reprogramming factors (c-Myc and Klf4) and one chondrogenic factor (SOX9) directly induces chondrogenic cells from mouse dermal fibroblast (MDF) culture. To gain insights into the process by which cellular characteristics are altered by transduction of c-Myc, Klf4 and SOX9, we examined marker gene expression in the MDF culture at various time points after transduction. The expression of fibroblast-markers was reduced first, followed by an increase in the expression of a chondrocyte-marker. We detected no expression of pluripotent markers at any time point examined. To determine whether or not induced chondrogenic cells go through a pluripotent state after transduction, we analyzed MDFs prepared from Nanog-GFP transgenic mice by monitoring expression of the GFP-labeled pluripotent marker Nanog-GFP in the MDF culture, using time-lapse microscopic observation. Whole-well time-lapse observation revealed that none of the induced chondrogenic cells displayed GFP fluorescence during induction. These results indicate that cells do not undergo a pluripotent state during direct induction of chondrogenic cells from fibroblast culture by transduction of c-Myc, Klf4 and SOX9.

Generation of hyaline cartilaginous tissue from mouse adult dermal fibroblast culture by defined factors.

Repair of cartilage injury with hyaline cartilage continues to be a challenging clinical problem. Because of the limited number of chondrocytes in vivo, coupled with in vitro de-differentiation of chondrocytes into fibrochondrocytes, which secrete type I collagen and have an altered matrix architecture and mechanical function, there is a need for a novel cell source that produces hyaline cartilage. The generation of induced pluripotent stem (iPS) cells has provided a tool for reprogramming dermal fibroblasts to an undifferentiated state by ectopic expression of reprogramming factors. Here, we show that retroviral expression of two reprogramming factors (c-Myc and Klf4) and one chondrogenic factor (SOX9) induces polygonal chondrogenic cells directly from adult dermal fibroblast cultures. Induced cells expressed marker genes for chondrocytes but not fibroblasts, i.e., the promoters of type I collagen genes were extensively methylated. Although some induced cell lines formed tumors when subcutaneously injected into nude mice, other induced cell lines generated stable homogenous hyaline cartilage­like tissue. Further, the doxycycline-inducible induction system demonstrated that induced cells are able to respond to chondrogenic medium by expressing endogenous Sox9 and maintain chondrogenic potential after substantial reduction of transgene expression. Thus, this approach could lead to the preparation of hyaline cartilage directly from skin, without generating iPS cells.