Graft Suturing Method Affects on Graft Diameter in Hamstring-Based Anterior Cruciate Ligament Reconstruction.

INTRODUCTION:  Various benefits of needleless suture loop techniques in anterior cruciate ligament reconstruction graft preparation have been discussed, yet their impact on graft diameter remains unexplored. We hypothesized that the suture loop technique would reduce the graft diameter compared to the conventional locking suture technique. METHODS:  Fifty-seven patients whose grafts were made with the Krackow stitch (group K) and 54 patients with the suture loop (group SL) were analyzed retrospectively. (1) The distal (sutured side) diameter of each anteromedial bundle and posterolateral bundle was compared to the proximal (non-sutured side) diameter, and (2) the average of the proximal and distal graft diameters in each group was calculated. RESULTS:  In group K, 78.9% of anteromedial bundles and 40.3% of posterolateral bundles exhibited a larger distal diameter than the proximal, while in group SL, 42.6% of anteromedial bundles and 3.7% of posterolateral bundles showed a larger distal diameter. In both bundles, there were significantly fewer grafts with larger distal diameters in group SL (p < 0.001). The mean distal diameter of anteromedial bundles was smaller in group SL (6.33 ± 0.43 mm vs. 6.07 ± 0.43 mm, p < 0.005). Consequently, the distal cross-sectional area of anteromedial bundles in group SL was 8% smaller than that in group K. CONCLUSION:  The use of the suture loop technique resulted in a significantly smaller distal diameter of the anteromedial bundle. This reduces the size of the tibial tunnel and may contribute to a reduction in potential damage to adjacent structures.

Spontaneous Recurrent Hemarthrosis of the Knee: A Report of Two Cases with a Source of Bleeding Detected during Arthroscopic Surgery of the Knee Joint.

We report two cases of the spontaneous recurrent hemarthrosis of the knee. In these cases lateral meniscus was severely torn and a small tubular soft tissue with pulsation was identified on the synovium in the posterolateral corner during arthroscopic surgery of the knee joint. Gentle grasping of this tissue by forceps led to pulsating bleeding, which stopped by electrocoagulation. This soft tissue was considered a source of bleeding, since no recurrence of hemarthrosis was observed for more than four years after surgery. It was highly probable that this soft tissue was the ruptured end of the lateral inferior genicular artery or its branch. This case report strongly supports the theory that the bleeding from the peripheral arteries of the posterior portion of the lateral meniscus is the cause of spontaneous recurrent hemarthrosis of the knee.

Gravity-assisted pivot-shift test can predict the function of the reconstructed anterior cruciate ligament.

PURPOSE: The gravity-assisted pivot-shift (GAPS) test is a newly advocated test for anterior cruciate ligament (ACL) injury. We retrospectively investigated the relationships between the result of preoperative GAPS test and the function of the reconstructed ACL using autogenous hamstring tendon grafts. METHODS: Seventy-eight patients with unilateral ACL injury and a minimum of 1-year follow-up were enrolled in this study. According to the result of preoperative GAPS test, they were divided into two groups, i.e., positive test group (Group P) and negative test group (Group N). At the time of follow-up, the operated knee was examined manually and using KT-1000 arthrometer. According to these results, the function of the reconstructed ACL was classified. RESULTS: The proportion of the knees with a negative abnormal laxity test was less in Group P than Group N with the significant difference in Lachman test (P = 0.0029) and N-test (P = 0.0081). The proportion of the cases having greater than 3 mm of the side-to-side difference in anterior knee laxity using KT-1000 arthrometer was greater in Group P, in spite of no statistically significant difference. Regarding the classification of the function of the reconstructed ACL, Group P was worse than Group N (P = 0.0187), and all 4 knees classified as failed belonged to Group P. CONCLUSION: The knees with a preoperative positive GAPS test showed worse postoperative function of the reconstructed ACL than those with a negative test. Preoperative positive GAPS test is considered to be a predisposing factor to poor functional outcome after ACL reconstruction. It is possible that the use of hamstring tendons as a graft source should be avoided for the ACL-injured patients with a positive GAPS test.

Contributory factors to the results of gravity-assisted pivot-shift test for anterior cruciate ligament injury: the significance of muscle torque around the knee.

Gravity-assisted pivot-shift (GAPS) test is a newly advocated test for anterior cruciate ligament (ACL) injury. It induces anterolateral rotatory instability with valgus stress to the knee applied by gravitational force during patient's active knee motion. We investigated prospectively the relationships between the results of the GAPS test and the possible contributory factors and sought to clarify the determinant factors of the GAPS test. A total of 54 knee joints of 54 patients with unilateral ACL injury (29 males, 25 females, average 23.4 +/- 9.0 years old) were enrolled in this study and were divided into two groups, i.e., positive GAPS test group and negative GAPS test group. Muscle torque around the knee joints measured before surgery, configuration of the femoral condyle and tibial posterior slope angle measured on lateral radiograph, and other clinical factors were compared between the two groups using Mann-Whitney U test or chi-square test. According to the results of these analyses, factors having a statistically significant difference were additionally evaluated using multiple logistic regression analysis to reveal items with strong relevance to a positive GAPS test. The results of the multiple logistic regression analysis showed that the flexor/extensor peak torque ratio of contralateral uninjured knees and sex had a significant correlation with the results of the GAPS test. The relatively less flexor muscle torque compared with extensor muscle torque, and being a female patient were considered to be the determinant factors of a positive GAPS test.

Fluoroscopic-based navigation-assisted placement of the tibial tunnel in revision anterior cruciate ligament reconstruction.

With the increasing number of primary anterior cruciate ligament (ACL) reconstructions, revisions are more frequent. The most common cause of technical failure in primary ACL reconstruction is the bone tunnel misplacement. An incorrectly positioned bone tunnel or tunnel enlargement interferes with correct tunnel placement, which is critical for successful restoration of the knee kinematics. We describe a technique using fluoroscopic-based navigation systems to place the tibial tunnel in an ideal position with accuracy and reproducibility in the revision ACL reconstruction. With a reference frame attached to the middle part of the tibia, the conventional tibial guide with a tracking device provides surgeons with real-time visual guidance in multiple image planes. In 3 revision cases with incorrect tibial tunnels and without bone enlargement, the new tibial tunnel could be created in the ideal position under the control of the navigation system. Computer navigation and virtual ligament reconstruction enable surgeons to control bone tunnel positioning during technically demanding revision ACL cases.

Intra-articular fibrous tissue formation following ankle fracture: the significance of arthroscopic debridement of fibrous tissue.

PURPOSE: The purposes of this study were to understand the clinical consequences of arthrofibrosis following surgical reduction of ankle fractures and to examine the effectiveness of arthroscopic debridement. METHODS: Subjects included 33 patients (26 males, 7 females) aged 14 to 78 years (mean, 40.2 years) who had undergone open reduction and internal fixation of ankle fractures between May 2000 and May 2003. Arthroscopic examination was performed at the time of implant removal after an average of 12.4 months (range, 6 to 43 months), and abnormal fibrous tissue, when present, was removed through arthroscopy. The mean follow-up period after arthroscopy was 43.7 months (range, 22 to 68 months). Clinical outcomes before and after arthroscopy were evaluated with the American Orthopaedic Foot and Ankle Society scale and our own functional evaluation method. Arthroscopic findings, including the degree of articular cartilage damage and the quantity of fibrous tissue, were scored on a 3-point scale. RESULTS: Functional deterioration of the ankle joint was observed in 27% of subjects. Arthroscopy showed articular cartilage damage in 33% of patients and arthrofibrosis in 73%. In patients with functional deterioration, the rate of articular cartilage damage was 78%, and arthrofibrosis was present in all cases. Furthermore, when extensive fibrosis and impingement on the articular surface were present, 88% of patients showed impaired articular function. Arthroscopic debridement of fibrous tissue resulted in improved articular function in 89% of patients with functional deterioration of the ankle joint before arthroscopy. CONCLUSIONS: Arthrofibrosis following ankle fracture causes an unfavorable surgical outcome, and arthroscopic debridement of fibrous tissue is an effective means of improving articular function. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Endoscopic anterior cruciate ligament reconstruction using a computer-assisted fluoroscopic navigation system.

BACKGROUND: During anterior cruciate ligament (ACL) reconstruction, placement of the reconstructed ligament affects the clinical results. To accomplish accurate and reproducible placement of the tibial bone tunnel, we employed a fluoroscopic navigation system for endoscopic ACL reconstruction. In this study, preciseness of the tibial tunnel placement was evaluated, and the advantages and disadvantages of this navigation system for endoscopic ACL reconstruction are discussed. METHODS: Altogether, 16 knees of 16 patients who had undergone ACL reconstruction using this system (navi group) were evaluated regarding the positioning of the tibial tunnel against Blumensaat's line using X-p and the route of the graft by magnetic resonance imaging (MRI). Another 16 knees of 16 patients who underwent endoscopic ACL reconstruction without the navigation system were the controls (control group). RESULTS: At the 1-year follow-up, maximally extended lateral knee X-p revealed that the anterior edge of the tibial tunnel and Blumensaat's line were almost aligned and that roof impingement was avoided; the T2-weighted MR images showed that the graft was placed close to and parallel to the intercondylar roof in all the knees of the navi group. The ratio of the distance between Blumensaat's line and the anterior edge of the tibial tunnel at the level of the tibial plateau to the anteroposterior width in fully extended true lateral radiographs was 2.7% +/- 3.4% in the navi group and 8.4% +/- 7.4% in the control group. CONCLUSIONS: The computer-assisted fluoroscopic navigation system improves accuracy and decreases dispersion of the tibial tunnel placement against Blumensaat's line in single-bundle ACL reconstruction. This innovative device renders the reconstruction procedure more reliable, eliminating the problem of skeletal variation among patients. However, the function of this navigation system for femoral tunnel placement is insufficient at present. Further refinement of the system is necessary, and the method of application requires improvement.

Effect of GDF-5 on ligament healing.

The effects of growth and differentiation factor-5 (GDF-5) on ligament healing were studied using a gap injury model of the medial collateral ligament in rat knee joints. The administration of GDF-5 once at the time of surgery significantly improved the mechanical properties of the femur-ligament-tibia complex. At 3 weeks after surgery, 30 microg of GDF-5 improved the ultimate tensile strength of the complex by 41%, and the stiffness by 60%, compared with the vehicle control (p < 0.05 for both; Fisher's PLSD test). The observation with a transmission electron microscopy revealed that GDF-5 increased the diameter of collagen fibrils in the repair tissue, which was considered to be a possible mechanism for the positive result in the biomechanical testing. Quantitative PCR and in situ hybridization revealed enhanced type I procollagen expression by GDF-5, and the PCR analysis also revealed that the GDF-5 treatment reduced the expression of type III procollagen relative to type I procollagen. The PCR analysis further showed that the expression of decorin and fibromodulin was relatively reduced against type I procollagen by the growth factor, which was considered to be responsible for the increase of collagen fibril diameter in the repair tissue. No adverse effects were observed, and the use of GDF-5 was considered a promising approach to facilitate ligament healing.

Gravity-assisted pivot-shift test for anterior cruciate ligament injury: a new procedure to detect anterolateral rotatory instability of the knee joint.

The denominated gravity-assisted pivot-shift test was introduced as a new procedure to detect anterolateral rotatory instability of the knee joint. The patient lies in the supine position or slightly rotated onto the affected side. The affected knee flexed approximately 60 degrees and the ipsilateral hip flexed, abducted and externally rotated so that the plane of the knee motion runs parallel to the floor. The examiner instructs the patient to raise the affected leg off the examining table and to extend the affected knee gradually. If the lower leg is internally rotated suddenly, with the knee subluxated at an angle of approximately 20 degrees , followed by the reduction in flexion, this test is regarded as positive. This test was investigated on 51 anterior cruciate ligament (ACL) deficient knees, being positive in 30 knees (Group P) and negative in 21 (Group N) with the positive rate of 59%. There was no significant correlation between the result of this test and the clinical features, but Group N included relatively small number of females and recurrent injuries tended to occur more frequently in Group P. Thirty-six knees received ACL reconstruction subsequently. There was no statistically significant difference between the groups in the side-to-side difference in anterior knee laxity at one year postoperatively. However, three patients with the side-to side difference of more than 3 mm belonged to Group P. Relatively low positive rate in ACL deficient knees suggests that it may not be used as a diagnostic procedure for ACL injury. It is possibly used for the prediction of high risk patients for symptomatic giving-way and/or patients with poor prognosis after ACL reconstruction.

A type II collagen mutation also results in oto-spondylo-megaepiphyseal dysplasia.

Oto-spondylo-megaepiphyseal dysplasia (OSMED) is a skeletal dysplasia characterized by severe sensorineural hearing loss, enlarged epiphyses and early onset of osteoarthritis. COL11A2 has been reported as a causative gene for OSMED. We have identified a novel COL2A1 mutation at a splice-acceptor site within intron 10 (c.709-2A>G) in an OSMED patient. This mutation caused the skipping of exon 11, and of exons 11 and 13. These exon-skipping events are presumed to cause an in-frame deletion of the triple helical region of the COL2A1 product. Thus, our findings highlight the genetic heterogeneity of OSMED and extend the phenotypic spectrum of type II collagenopathy, as well as confirming the overlap between type II and type XI collagenopathies.

Novel and recurrent mutations clustered in the von Willebrand factor A domain of MATN3 in multiple epiphyseal dysplasia.

Multiple epiphyseal dysplasia (MED) is a common skeletal dysplasia characterized by joint pain and stiffness, delayed and irregular ossification of epiphyses, and early-onset osteoarthritis. Six genes responsible for MED have been identified, including COMP, COL9A1, COL9A2, COL9A3, DSTDT and MATN3. MATN3 encodes matrilin-3, a cartilage-specific extracellular matrix protein. To date, seven different MATN3 mutations have been identified; all are located within the beta-sheet regions of the von Willebrand factor type A (vWFA) domain, which is encoded by exon 2. We examined MATN3 mutations in27 Japanese MED patients who were possibly autosomal dominant inheritance and had been excluded for COMP mutations. Ten of them had a positive family history. We examined all eight exons of MATN3 by PCR and direct sequencing from genomic DNA. We have identified four missense mutations in eight unrelated families; two are novel, and two have been characterized previously. Like previously characterized MATN3 mutations, those identified in this study are clustered within exon 2, specifically in and around the 2nd beta-sheet region of the vWFA domain (aa. 120-127). Contrary to the previous assumption that the MATN3 mutation in MED is confined to the beta-sheet regions, one novel mutation (p.F105S) is located outside the beta-sheet region, within an alpha-helix region.

Distinct roles of Smad pathways and p38 pathways in cartilage-specific gene expression in synovial fibroblasts.

The role of TGF-beta/bone morphogenetic protein signaling in the chondrogenic differentiation of human synovial fibroblasts (SFs) was examined with the adenovirus vector-mediated gene transduction system. Expression of constitutively active activin receptor-like kinase 3 (ALK3CA) induced chondrocyte-specific gene expression in SFs cultured in pellets or in SF pellets transplanted into nude mice, in which both the Smad and p38 pathways are essential. To analyze downstream cascades of ALK3 signaling, we utilized adenovirus vectors carrying either Smad1 to stimulate Smad pathways or constitutively active MKK6 (MKK6CA) to activate p38 pathways. Smad1 expression had a synergistic effect on ALK3CA, while activation of p38 MAP kinase pathways alone by transduction of MKK6CA accelerated terminal chondrocytic differentiation, leading to type X collagen expression and enhanced mineralization. Overexpression of Smad1 prevented MKK6CA-induced type X collagen expression and maintained type II collagen expression. In a mouse model of osteoarthritis, activated p38 expression as well as type X collagen staining was detected in osteochondrophytes and marginal synovial cells. These results suggest that SFs can be differentiated into chondrocytes via ALK3 activation and that stimulating Smad pathways and controlling p38 activation at the proper level can be a good therapeutic strategy for maintaining the healthy joint homeostasis and treating degenerative joint disorders.

The influence of tibial fixation on tunnel enlargement after hamstring tendon anterior cruciate ligament reconstruction.

The retrospective study was designed to evaluate tibial-tunnel enlargement after anterior cruciate ligament reconstruction with hamstring autograft. Forty-three patients (43 knees) were enrolled, among whom a spiked washer was used for the tibial side fixation in 20 knees (Group SW) and the WasherLoc was used in 23 knees (Group WL). After an average 16 (range 12-32) months' follow-up, the distance between the sclerotic margins of the tibial tunnel was measured at the joint level, and 1 and 2 cm distal to the joint level on the lateral view radiographs, from which the tibial-tunnel enlargement at each point (E1, E2, and E3 respectively) was determined. Anterior knee laxity was also measured using a KT-1000 or KT-2000 arthrometer at follow-up. E1, E2, and E3 were 2.3+/-1.3 mm (mean+/-standard deviation), 1.8+/-0.8 mm, and 1.5+/-0.8 mm respectively in Group SW, and 2.6+/-1.0 mm, 2.6+/-1.2 mm, and 2.9+/-1.6 mm in Group WL. Group WL had a larger mean value than Group SW at each level of measurement, with a statistically significant difference in E2 and E3. Fifty percent of the tunnels were the cone type in Group SW, whereas reversed cone-type tunnels were the most common (39%) in Group WL. The side-to-side difference in anterior knee laxity was -0.6+/-5.2 mm in Group SW and 1.8+/-9.0 mm in Group WL, which was significantly different between the groups. No statistical relationship was found between tunnel enlargement and side-to-side difference in anterior knee laxity in Group SW, whereas there was a slight negative correlation between E1 or E2 and anterior knee laxity in Group WL. It is possible that there is greater tension applied to the graft when the WasherLoc is used, which creates larger compressive forces on the posterior wall of the tibial tunnel by the graft. This was probably the reason for the greater tunnel enlargement and the high incidence of the reversed cone-type tunnel in Group WL.

A new technique to expand human mesenchymal stem cells using basement membrane extracellular matrix.

Mesenchymal stem cells (MSC) show a very short proliferative life span and readily lose the differentiation potential in culture. However, the growth rate and the proliferative life span of the stem cells markedly increased using tissue culture dishes coated with a basement membrane-like extracellular matrix, which was produced by PYS-2 cells or primary endothelial cells. Furthermore, the stem cells expanded on the extracellular matrix, but not those on plastic tissue culture dishes, retained the osteogenic, chondrogenic, and adipogenic potential throughout many mitotic divisions. The extracellular matrix had greater effects on the proliferation of MSC and the maintenance of the multi-lineage differentiation potential than basic fibroblast growth factor. Mesenchymal stem cells expanded on the extracellular matrix should be useful for regeneration of large tissue defects and repeated cell therapies, which require a large number of stem or progenitor cells.

Association analysis of single nucleotide polymorphisms in cartilage-specific collagen genes with knee and hip osteoarthritis in the Japanese population.

Osteoarthritis (OA) is one of the most common diseases in the elderly. Although its pathophysiology is complex and its molecular basis remains to be determined, much evidence suggests that OA has strong genetic determinants. To search for susceptibility loci of OA, we selected seven candidate genes encoding cartilage-specific collagens (type II, IX, X, and XI collagens) and performed association analysis for OA using single nucleotide polymorphisms (SNPs) in the coding region of these genes. Four hundred seventeen OA samples and 280 control samples were collected from the Japanese population, and 12 SNPs were genotyped. Our studies have identified two susceptibility loci of OA: COL2A1 and COL9A3. An SNP in COL9A3 showed significant association with knee OA (p = 0.002, odds ratio [OR] = 1.48). Haplotype analysis showed significant association between a specific haplotype of COL2A1 and hip OA (p = 0.024; OR = 1.30). Further analysis of these two genes will shed light on the molecular mechanisms of OA.

[Non-surgical treatments for Gonarthrosis].

The cause or progression of gonarthrosis have multifactor. Many varieties of treatments for this degenerative disease exist and indications of the treatments are complicated. Non-surgical treatments for gonarthrosis including quadriceps strengthen exercise and insole therapy were summarized. Further, force distribution in foot prints wearing one of three type of insole, lateral wedged, arch supported or combined insoles, were investigated using F-scan system, and different dynamic mechanisms of three types of insoles were revealed.