Effects of Preserving Anatomically Positioned and Adequate Remnant ACL Tissue in Double-Bundle ACL Reconstruction.

Background: The advantages of remnant tissue preservation in anterior cruciate ligament (ACL) reconstruction (ACLR) remain controversial. Hypothesis: It was hypothesized that a large amount of remnant tissue, especially if anatomically positioned, would improve patient-reported outcomes and second-look graft appearance after preserved double-bundle ACLR (DB-ACLR). Study Design: Cohort study; Level of evidence, 3. Methods: This retrospective study included 89 consecutive patients who underwent unilateral remnant-preserving DB-ACLR using 2 hamstring tendon autografts. The authors categorized the arthroscopic findings into 3 groups according to the location and volume of the ACL remnant tissue in the femoral notch: (1) anatomical attachment (group AA; n = 34); (2) nonanatomical attachment (group NA; n = 33); and (3) no remnant (group NR; n = 22). Based on second-look arthroscopy, the reconstructed graft was graded as excellent, fair, or poor. Patient-reported outcomes were evaluated at 2 years after surgery using the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Japanese Anterior Cruciate Ligament Questionnaire-25 (JACL-25). Results: The AA and NA groups had a significantly shorter time from injury to surgery compared with the NR group (P = .0165). Considering the second-look arthroscopic findings, the authors found a significant difference in synovial coverage of the grafts between the 3 groups (P = .0018). There were no significant differences in the overall KOOS and JACL-25 score among the 3 groups; however, the KOOS-Sport and Recreation and KOOS-Quality of Life subscale scores were significantly higher in the AA group compared with the NA and NR groups (P = .0014 and .0039, respectively). The JACL-25 score for middle- to high-speed flexion and extension was significantly better in the AA group versus the NR group (P = .0261). Conclusion: This study showed that preserving anatomically positioned and adequate remnant tissue during DB-ACLR improved second-look graft appearance and KOOS-Sport and Recreation and KOOS-Quality of Life scores.

Inclination of Blumensaat's line influences on the accuracy of the quadrant method in evaluation for anterior cruciate ligament reconstruction.

PURPOSE: The quadrant method is used to evaluate the bone tunnel position with the grid based on the Blumensaat's line in anterior cruciate ligament (ACL) reconstruction. This study aimed to clarify the influence of variation in the Blumensaat's line on the accuracy of the quadrant method measurements. METHODS: A retrospective review of the radiological records of patients aged 18-30 years who underwent computed tomography (CT) scanning of the knee joint was conducted. The Blumensaat's line inclination angle (BIA), along with the most posterior point of the posterior condyle (point P) position using the quadrant method and morphology of the Blumensaat's line were measured on true lateral transparent three-dimensional CT images of the distal femoral condyle in 147 patients. Statistical analysis was conducted to determine associations among these measurements. RESULTS: BIA was 37.5° (standard deviation 4.2°; range 27°-48°). The point P position was significantly correlated with BIA in the high/low (R2 = 0.590, P < 0.0001) and deep/shallow (R2 = 0.461, P < 0.0001) directions. The morphology of the Blumensaat's line was straight in 35 knees (23.8%); whereas, the remaining 112 knees (76.2%) were not straight but had some hill on the Blumensaat's line. No significant difference among the morphological variation of the Blumensaat's line was observed in BIA and the point P position. CONCLUSION: There was a strong correlation between BIA and the point P measured using the quadrant method, suggesting the influence of the Blumensaat's line on the accuracy of the quadrant method measurements in ACL reconstruction. As for the clinical relevance, surgeons should be careful in application of the quadrant method for ACL reconstruction, because the variation of the Blumensaat's line inclination influences the accuracy of this method.

Preoperative knee deformity and kinematics impact postoperative knee kinematics in total knee arthroplasty.

BACKGROUND: The purpose of this study was to evaluate the relationship between the preoperative knee deformity/kinematic pattern and the postoperative knee kinematic pattern in posterior cruciate ligament substituting (PS)-total knee arthroplasty (TKA). METHODS: This study involved 39 patients with medial osteoarthritis who underwent a primary PS-TKA using a computed-tomography-based navigation system. All the operations were performed by a single surgeon using a subvastus approach, modified gap technique and the same PS type of prosthesis (Genesis II™ total knee system, Smith & Nephew, Memphis, TN, USA). Knee deformity, kinematic pattern after capsule incision (preoperative knee kinematics), and kinematic pattern after implantation (postoperative knee kinematics) in PS-TKA were measured. Kinematic patterns were divided into two groups: a medial pivot group and a non-medial pivot group. RESULTS: Preoperative varus knee deformity was significantly larger in the non-medial pivot group than in the medial pivot group (femorotibial angle: 184.7±6.4° vs. 180.8±3.9°, P<0.05). In addition, preoperative knee kinematics were conserved postoperatively, at a rate of 82% (P<0.01). CONCLUSIONS: The severity of varus knee deformity and the preoperative knee kinematic pattern might have affected the postoperative knee kinematics in PS-TKA. This must be confirmed with a randomized controlled trial on a large population study. LEVEL OF EVIDENCE: case control study, Level III.

Effects of Multiple Intra-articular Injections of 0.5% Bupivacaine on Normal and Osteoarthritic Joints in Rats.

PURPOSE: To determine the in vivo effects of multiple local anesthetic injections of 0.5% bupivacaine on normal and osteoarthritic articular cartilage. METHODS: Rats with normal knee joints received an intra-articular injection of 0.9% saline solution or 0.5% bupivacaine in their right knees joint once a week for 5 consecutive weeks, starting 4 weeks after the beginning of the experiment. Rats were humanely killed at 8, 16, and 24 weeks. In a parallel experiment, rats underwent anterior cruciate ligament transection to induce osteoarthritic changes. These rats were subjected to the same protocol as those with normal knee joints, starting 4 weeks after the procedure. Static weight-bearing tests were performed on both hind limbs to evaluate changes in weight-bearing ability throughout the experiments. Rats were humanely killed at 8 and 16 weeks. Cell viability was assessed with confocal microscopy, using samples from the distal femur. Histologic assessment of osteoarthritis was performed using samples from the tibial plateau based on the Osteoarthritis Research Society International (OARSI) cartilage histopathology assessment system (i.e., OARSI score). RESULTS: Static weight-bearing tests showed no significant changes after intra-articular injection of saline solution or bupivacaine, and bupivacaine injection did not increase weight bearing compared with saline solution injection, regardless of whether there were osteoarthritic changes. There were also no significant differences in cell viability, cell density, or OARSI scores between the saline solution and bupivacaine groups at each time point, regardless of whether osteoarthritic changes were induced. CONCLUSIONS: This study suggested that single or intermittent intra-articular bupivacaine injections might not have deleterious effects on either osteoarthritic or normal joints. CLINICAL RELEVANCE: There is no strong evidence that intra-articular bupivacaine injection induces degenerative changes in articular cartilage. Therefore, these results may apply to normal and osteoarthritic joints.

Therapeutic effects of intra-articular ultra-purified low endotoxin alginate administration on an experimental canine osteoarthritis model.

OBJECTIVE: This study aimed to elucidate the therapeutic effects of intra-articular administration of ultra-purified low endotoxin alginate (UPLE-alginate) on osteoarthritis (OA) using a canine anterior cruciate ligament transection (ACLT) model. DESIGN: We used 20 beagle dogs. ACLT was performed on the left knee of each dog and a sham operation was performed on the right knee as a control. All animals were randomly divided into the control (saline) and therapeutic (UPLE-alginate) groups. Animals in the control and therapeutic groups received weekly injections with 0.7 mL normal saline or 0.7 mL 0.5% UPLE-alginate, respectively, from 0 to 3 weeks after ACLT or sham operation. At 9 weeks after ACLT, the knee joints of all animals were observed using arthroscopy. All animals were euthanized at 14 weeks after ACLT and evaluated using morphologic assessment, histologic assessment, and biomechanical testing. RESULTS: Arthroscopic findings showed intact cartilage surface in both groups. Morphologic findings in the therapeutic group showed milder degeneration compared with those of the control group, but there were no significant differences between groups. Histologic scores of the medial femoral condyle (MFC) and lateral femoral condyle (LFC) were better in the therapeutic group than the control group (MFC: p = 0.009, LFC: p = 0.009). Joint lubrication did not differ significantly between groups. CONCLUSION: Intra-articular administration of UPLE-alginate in the early stage of OA slowed disease progression in canines. UPLE-alginate may have potential as a therapeutic agent for OA patients and reduce the number of patients who need to undergo total joint arthroplasty.

A Comparative Study With In Vitro Ultrasonographic and Histologic Grading of Metatarsal Head Cartilage in Rheumatoid Arthritis.

BACKGROUND: Ultrasonography is among the valid methods to assess articular cartilage in the foot. This study aimed to evaluate the validity of ultrasonographic grading to assess metatarsal head articular cartilage for rheumatoid forefoot deformity in vivo and to compare the findings with in vitro ultrasonographic and histologic gradings. METHODS: Participants were 15 patients scheduled to undergo resection arthroplasty of the metatarsal heads of the lesser toes because of rheumatoid arthritis of the metatarsophalangeal joints. Ultrasonographic examination was performed in vivo the day before surgery. Specimens of the second to fifth metatarsal heads taken intraoperatively were graded from in vitro ultrasonographic and histologic evaluations. Correlations among in vivo ultrasonographic, in vitro ultrasonographic, and histologic gradings were analyzed. RESULTS: In 46 metatarsal heads, the distribution of grading ranged from grade 1 to 6 for in vivo ultrasonographic examinations and from grade 1 to 4 for histologic examinations. In vivo ultrasonographic grading showed significant correlation to both in vitro ultrasonographic grading (P < .001, R = 0.74) and histologic grading (P < .001, R = 0.67). CONCLUSIONS: The significant correlations between in vivo ultrasonographic and histologic gradings suggest that a semiquantitative in vivo ultrasonographic assessment of forefoot deformity in rheumatoid arthritis may be possible. Ultrasonographic grading may prove useful for pre- and postoperative evaluation of remaining joint function in rheumatoid forefoot deformity. An ultrasonographic grading system for remaining joint surfaces might be helpful in selecting surgical procedures such as joint-sparing osteotomy and metatarsal head resection. LEVEL OF EVIDENCE: Level IV, case series.

External rotation of the femoral component decreases patellofemoral contact stress in total knee arthroplasty.

PURPOSE: The purpose of this study was to investigate the relationship between patellofemoral (PF) contact stress in vivo and the alignment of the femoral component in patients after total knee arthroplasty (TKA). METHODS: Thirty knees with medial compartment osteoarthritis that underwent mobile-bearing TKA with modified gap technique were evaluated. Surgery was performed using a subvastus approach to eliminate the effect of the approach to muscle balance, with a computed tomography-based navigation system (Vector Vision 1.61; Brain Lab, Heimstetten, Germany). PF contact stress was measured by a Flexiforce pressure sensor (Nitta Co., Ltd., Osaka, Japan) intraoperatively, and the results were compared with the alignment of the femoral component after TKA. RESULTS: The PF contact stress was not correlated with sagittal and coronal alignment of the femoral component and patellar tracking, whereas rotational alignment of the femoral component was negatively correlated with PF contact stress (r = -0.718, p < 0.01). CONCLUSIONS: Regarding the alignment of the femoral component, only the rotational alignment of the femoral component was correlated with PF contact stress. PF contact stress decreased more as the femoral component rotated more externally. LEVEL OF EVIDENCE: Case control study, Level III.

Intraoperative medial pivot affects deep knee flexion angle and patient-reported outcomes after total knee arthroplasty.

The aim of this study was to evaluate the relationship between clinical results including patient-reported outcomes and intraoperative knee kinematic patterns after total knee arthroplasty (TKA). A cross-sectional survey of forty consecutive medial osteoarthritis patients who had a primary TKA using a CT-based navigation system was conducted. Subjects were divided into two groups based on intraoperative kinematic patterns: a medial pivot group (n = 20) and a non-medial pivot group (n = 20). Subjective outcomes with the new Knee Society Score and clinical outcomes were evaluated. The functional activities, patient satisfaction and the knee flexion angle of the medial pivot group were significantly better than those of the non-medial pivot group. An intraoperative medial pivot pattern positively influences deep knee flexion and patient-reported outcomes.

Sagittal alignment of the first metatarsophalangeal joint after arthrodesis for rheumatoid forefoot deformity.

The present study assessed the midterm results of reconstruction for rheumatoid forefoot deformity with arthrodesis of the first metatarsophalangeal (MTP) joint, scarf osteotomy, resection arthroplasty of the metatarsal head of the lesser toes, and surgical repair of hammertoe deformity (arthrodesis of the proximal interphalangeal joint). Special focus was placed on the sagittal alignment of the first metatarsophalangeal joint after arthrodesis. We retrospectively evaluated the postoperative clinical outcomes and radiographic findings for 16 consecutive female patients (20 feet) with symptomatic rheumatoid forefoot deformities. The mean duration of follow-up was 7.9 (range 4 to 13) years. All first MTP joints and first metatarsal bones were fused successfully. The mean value of the American Orthopaedic Foot and Ankle Society and Japanese Society for Foot Surgery clinical scores significantly improved overall, except for 2 patients (10%), who complained of first toe pain at the final follow-up visit owing to sagittal misalignment of the fused first MTP joint. Sagittal alignment of the first metatarsal varies greatly because of the rheumatoid midfoot and hindfoot deformities. Therefore, inclination of the first metatarsal should be considered when determining the first MTP joint sagittal fusion angle.

What are the causes of revision total knee arthroplasty in Japan?

BACKGROUND: There is limited information regarding the cause of revision TKA in Asia, especially Japan. Owing to differences in patient backgrounds and lifestyles, the modes of TKA failures in Asia may differ from those in Western countries. QUESTIONS/PURPOSES: We therefore determined (1) causes of revision TKA in a cohort of Japanese patients with revision TKA and (2) whether patient demographic features and underlying diagnosis of primary TKA are associated with the causes of revision TKA. METHODS: We assessed all revision TKA procedures performed at five major centers in Hokkaido from 2006 to 2011 for the causes of failures. Demographic data and underlying diagnosis for index primary TKA of the revision cases were compared to those of randomly selected primary TKAs during the same period. RESULTS: One hundred forty revision TKAs and 4047 primary TKAs were performed at the five centers, indicating a revision burden of 3.3%. The most common cause of revision TKA was mechanical loosening (40%) followed by infection (24%), wear/osteolysis (9%), instability (9%), implant failure (6%), periprosthetic fracture (4%), and other reasons (8%). The mean age of patients with periprosthetic fracture was older (77 versus 72 years) and the male proportion in patients with infection was higher (33% versus 19%) than those of patients in the primary TKA group. There was no difference in BMI between primary TKAs and any type of revision TKA except other causes. CONCLUSIONS: The revision burden at the five referral centers in Hokkaido was 3.3%, and the most common cause of revision TKA was mechanical loosening followed by infection. Demographic data such as age and sex might be associated with particular causes of revision TKA.

Celecoxib does not affect the release of hyaluronic acid in end stage osteoarthritic joints.

OBJECTIVES: Non-steroidal anti-inflammatory drugs play a major role in the management of osteoarthritis (OA). However, it remains unknown whether these drugs affect cartilage and synovial metabolism in osteoarthritic joints. The aim of this study was to evaluate the effects of a selective cyclooxygenase (COX)-2 inhibitor, celecoxib, on synovial fluids and tissues in severely osteoarthritic knees. METHODS: Patients were randomized into three groups and medicated two weeks prior to total knee arthroplasty with celecoxib, diclofenac sodium, or no medication (control). We checked for the presence of matrix metalloproteinase-3 (MMP-3), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and hyaluronic acid (HA) in the synovial fluids of all three groups. RESULTS: MMP-3 significantly decreased in the celecoxib-treated patients (p = 0.0031). On the other hand, there were no significant differences among the three groups in their TNF-α and IL-1ß levels. HA in the joint fluid was significantly increased in the diclofenac-treated group, while HA was not changed in the celecoxib-treated patients. CONCLUSIONS: Our study suggests that celecoxib did not affect the level of HA in the joint fluid in the knee in severe OA, in contrast to the effect of the dual COX inhibitor.

Hemorrhagic-acquired factor XIII deficiency associated with tocilizumab for treatment of rheumatoid arthritis.

Factor XIII (FXIII) is the final enzyme in the coagulation cascade. Acquired FXIII deficiency is caused by inhibitors of FXIII or decreased synthesis and/or increased consumption of FXIII, which leads to severe bleeding. Recently, we experienced a case of hemorrhagic-acquired factor XIII deficiency that occurred during treatment with the IL-6 inhibitor tocilizumab for rheumatoid arthritis. A 48-year-old man was referred because of right hip pain due to a hematoma. Laboratory findings showed that routine coagulation tests were normal, while FXIII activity was slightly low (52.4 %). The patient was successfully treated with plasma-derived factor XIII concentrates. The time course of recovery suggests that tocilizumab might have inhibited FXIII production. To our knowledge, this is the first report of acquired factor XIII deficiency associated with administering of tocilizumab. When recurrent bleeding is seen during administering of tocilizumab, acquired factor XIII deficiency may have been induced, thus attending physicians should consider this disease in a differential diagnosis.

Repair of rabbit osteochondral defects by an acellular technique with an ultrapurified alginate gel containing stromal cell-derived factor-1.

The objective of this study was to determine whether the local administration of stromal cell-derived factor-1 (SDF-1) using ultrapurified alginate gel (UPAL gel) could improve reparative tissues of osteochondral defects compared with those without treatment. For the investigation, a full-thickness osteochondral defect 4.5 mm in diameter and 3 mm in depth was created in the patella groove of the distal femur in rabbits. Local expression of SDF-1 protein was temporarily upregulated at 1 week after creating the osteochondral defect. The local administration of SDF-1 enhanced the migration of host cells, mainly bone marrow stromal cells (BMSCs), to the site of the osteochondral defect. In vitro cell migration assay supported this result. In the SDF-1 (UPAL gel containing SDF-1) treatment group, the histological scores and the compressive modulus of reparative tissues were significantly improved compared with the no-treatment and vehicle (UPAL gel without SDF-1) groups. On the other hand, SDF-1 did not influence the cellular proliferation and chondrogenesis of BMSCs. Based on the results obtained here, we speculate that SDF-1 enhances the reparative process of osteochondral injuries not through direct effects on the behavior of host cells, but through increased migration of host cells to the injured site. UPAL gel, as a vehicle material, may play an important role in chondrogenesis of recruited cells, mainly BMSCs. The cell-free approach with local administration of SDF-1 may be an effective strategy for developing a minimally invasive technique for cartilage tissue regeneration.

Repair of articular cartilage defects with a novel injectable in situ forming material in a canine model.

We developed an ultra-purified in situ forming gel as an injectable delivery vehicle of bone marrow stromal cells (BMSCs). Our objective was to assess reparative tissues treated with autologous BMSCs implanted using the injectable implantation system into osteochondral defects in a canine model. Forty-eight osteochondral defects in the patella groove of the knee joint were created in 12 adult beagle dogs (two defects in each knee). The defects were divided into a defect group (n = 16), an acellular novel material implantation (material) group (n = 16), and a BMSCs implantation using the current vehicle system (material with BMSCs) group (n = 16). The reparative tissues at 16 weeks postoperatively were assessed through gross, histological, and mechanical analyses. The reparative tissues of the material with BMSCs group were substituted with firm and smooth hyaline-like cartilage tissue that was perfectly integrated into the host tissues. This treatment group obviously enhanced the subchondral bone reconstruction. The compressive modulus of the reparative tissues was significantly higher in the material with BMSCs group than the other groups. This study demonstrated that the implantation of BMSCs using our novel in situ forming material induced a mature hyaline-like cartilage repair of osteochondral defects in a canine model.

A cellular implantation system using an injectable ultra-purified alginate gel for repair of osteochondral defects in a rabbit model.

We developed a novel cellular implantation system using an in situ forming ultra-purified alginate gel with quite low endotoxity. The aims of this study were to determine the superiority of chondrogenic potential of bone marrow stromal cells (BMSCs) cultured in the purified alginate gel compared with a commercial grade gel, and to assess reparative tissues treated with BMSCs implanted using the developed system into cartilage defects in rabbit knees. The effects of each alginate gel on cellular proliferation and chondrogenesis of rabbit BMSCs were determined by in vitro assessments. Using our purified alginate gel, a novel vehicle system for injecting BMSCs into osteochondral defects without periosteal patch was successfully established in this animal models. The in vitro analyses demonstrated that the purification of alginate significantly enhanced the cellular proliferation and chondrogenic differentiation of BMSCs. The in vivo assessments suggested that the implantation of BMSCs with the developed system using the purified alginate gel histologically and mechanically improved the reparative tissue of osteochondral defects. This system using the purified alginate gel shows the clinical potential for arthroscopically injectable implantation of BMSCs for the treatment of cartilaginous lesions.

Tunnel location in transparent 3-dimensional CT in anatomic double-bundle anterior cruciate ligament reconstruction with the trans-tibial tunnel technique.

It is difficult to precisely identify the locations of tunnels after double-bundle anterior cruciate ligament (ACL) reconstruction postoperatively. Using our novel transparent 3-dimensional computed tomography (T-3DCT), we evaluated intra-articular outlet locations and the angles of the anteromedial (AM) and posterolateral (PL) tunnels after anatomic double-bundle ACL reconstruction using the trans-tibial technique. A prospective study was performed with 123 consecutive patients. Tunnel outlet locations were identified on T-3DCT images showing the true lateral view of the femur and indicated by our originally defined X, Y coordinates. We also determined the angles between the tunnel axis and a joint surface line in the coronal plane, the long axis of the femur in the sagittal plane, and the posterior condyle line in the axial plane of both the femur and the tibia. The mean X, Y coordinates of the AM and PL tunnel outlets were 21, 43% and 0, 33%, respectively. In the coronal, sagittal, and axial planes, the mean AM femoral tunnel angles were 63 degrees, 48 degrees, and 55 degrees, respectively; the mean AM tibial tunnel angles in the tibia were 63 degrees, 49 degrees, and 71 degrees, respectively; the mean PL femoral tunnel angles were 38 degrees, 58 degrees, and 43 degrees, respectively; and the mean PL tibial tunnel angles were 46 degrees, 53 degrees, and 45 degrees, respectively. The AM and PL tunnel outlets and angles could be detailed precisely in three dimensions by using T-3DCT. This imaging technique may be useful to confirm surgical techniques and to improve clinical outcomes.