Takashi Horaguchi

Evaluation of the tunnel placement in the anatomical double-bundle ACL reconstruction: a cadaver study

The objective of this study was to investigate the accurate AM and PL tunnel positions in an anatomical double-bundle ACL reconstruction using human cadaver knees with an intact ACL. Fifteen fresh-frozen non-paired adult human knees with a median age of 60 were used. AM and PL bundles were identified by the difference in tension patterns. First, the center of femoral PL and AM bundles were marked with a K-wire and cut from the femoral insertion site. Next, each bundle was divided at the tibial side, and the center of each AM and PL tibial insertion was again marked with a K-wire. Tunnel placement was evaluated using a C-arm radiographic device. For the femoral side assessment, Bernard and Hertel’s technique was used. For the tibial side assessment, Staubli’s technique was used. After radiographic evaluations, all tibias’ soft tissues were removed with a 10% NaOH solution, and tunnel placements were evaluated. In the radiographic evaluation, the center of the femoral AM tunnel was placed at 15% in a shallow–deep direction and at 26% in a high–low direction. The center of the PL bundle was found at 32% in a shallow–deep direction and 52% in a high–low direction. On the tibial side, the center of the AM tunnel was placed at 31% from the anterior edge of the tibia, and the PL tunnel at 50%. The ACL tibial footprint was placed close to the center of the tibia and was oriented sagittally. AM and PL tunnels can be placed in the ACL insertions without any coalition. The native ACL insertion site has morphological variety in both the femoral and tibial sides. This study showed, anatomically and radiologically, the AM and PL tunnel positions in an anatomical ACL reconstruction. We believe that this study will contribute to an accurate tunnel placement during ACL reconstruction surgery and provide reference data for postoperative radiographic evaluation.

Intercondylar roof impingement pressure after anterior cruciate ligament reconstruction in a porcine model

Anterior cruciate ligament (ACL) graft impingement against the intercondylar roof has been postulated, but not thoroughly investigated. The roof impingement pressure changes with different tibial and femoral tunnel positions in ACL reconstruction. Anterior tibial translation is also affected by the tunnel positions of ACL reconstruction. The study design included a controlled laboratory study. In 15 pig knees, the impingement pressure between ACL and intercondylar roof was measured using pressure sensitive film before and after ACL single bundle reconstruction. ACL reconstructions were performed in each knee with two different tibial and femoral tunnel position combinations: (1) tibial antero-medial (AM) tunnel to femoral AM tunnel (AM to AM) and (2) tibial postero-lateral (PL) tunnel to femoral High-AM tunnel (PL to High-AM). Anterior tibial translation (ATT) was evaluated after each ACL reconstruction using robotic/universal force-moment sensor testing system. Neither the AM to AM nor the PL to High-AM ACL reconstruction groups showed significant difference when compared with intact ACL in roof impingement pressure. The AM to AM group had a significantly higher failure load than PL to High-AM group. This study showed how different tunnel placements affect the ACL-roof impingement pressure and anterior-posterior laxity in ACL reconstruction. Anatomical ACL reconstruction does not cause roof impingement and it has a biomechanical advantage in ATT when compared with non-anatomical ACL reconstructions in the pig knee. There is no intercondylar roof impingement after anatomical single bundle ACL reconstruction.

Evaluation of the intercondylar roof impingement after anatomical double-bundle anterior cruciate ligament reconstruction using 3D-CT

PurposeTo reveal the relationship between anatomically placed anterior cruciate ligament (ACL) graft and the intercondylar roof using three-dimensional computed tomography (3D-CT).MethodsTwenty-four patients undergoing anatomical double-bundle ACL reconstruction were included in this study. Anatomical double-bundle ACL reconstruction was performed with two femoral tunnels (antero-medial; AM and postero-lateral; PL) and two tibial tunnels. Hamstring autograft was used in all cases. Six to eight weeks after operation and when the subjects had obtained full extension of the knee, 3D-CT was performed with full knee extension. In the 3D-CT, the ACL graft was also reconstructed and visualized three dimensionally. Tunnel placement was evaluated with 3D-CT and intra-operative radiographs. The extension angle of the knee was also evaluated with 3D-CT.ResultsNo intercondylar roof impingement was observed. In 12 subjects, the ACL graft touched the roof (Touch group) but no graft deformation was observed. In 12 subjects, no roof-graft contact was observed (Non-touch group). No significant difference in femoral and tibial tunnel placement was observed between the Touch and Non-touch groups. All subjects attained full knee extension.ConclusionWe believe that 3D-CT is an effective means of evaluating impingement after ACL reconstruction. For the clinical relevance, when the grafts are positioned in an anatomical fashion, there is no risk of impingement, and surgeons can perform anatomical double-bundle ACL as an impingement-free reconstruction. Level of evidence: III (Case control study).

Association between intercondylar notch narrowing and bilateral anterior cruciate ligament injuries in athletes

BackgroundIntercondylar notch narrowing is a risk factor for anterior cruciate ligament (ACL) injuries, but it is unclear whether a narrow intercondylar notch correlates with bilateral ACL injuries.PurposeTo determine whether a narrow intercondylar notch is associated with bilateral ACL knee injuries in athletes, using magnetic resonance imaging (MRI) and radiography to investigate the notch size.Study designA retrospective case–control study.MethodsThis was a comparative cohort study on 50 subjects of which 25 patients with sport trauma-associated bilateral ACL injuries, 30 with unilateral ACL injuries, and 20 healthy subjects. The notch width index (NWI) was measured as the ratio of the width of the intercondylar notch to the femoral condylar width on radiography and the MRI slice containing the region near the ACL attachment site on the femoral side (NWI-A) and on the following posterior slice (NWI-P).ResultsThe mean NWI values on radiography were 0.257 (SD 0.040), 0.332 (SD 0.036), and 0.341 (SD 0.027) in the bilateral, unilateral, and control groups, respectively, with significant differences between the bilateral and unilateral groups and the bilateral and healthy groups. On MRI, the mean NWI-A values were 0.236 (SD 0.025), 0.243 (SD 0.048), and 0.266 (SD 0.030), respectively, with a significant difference between the bilateral and healthy groups. The mean NWI-P values were 0.239 (SD 0.021), 0.258 (SD 0.038), and 0.273 (SD 0.033), respectively, with significant differences between the bilateral and unilateral groups and the unilateral and healthy groups. A cutoff value of 0.25 for NWI-P gave an odds ratio of 22.667 for the risk of developing bilateral ACL knee injuries.ConclusionsThe intercondylar notch was significantly narrower in subjects with bilateral ACL injuries than in healthy subjects. NWI measurement using coronal MRI is useful for judging intercondylar notch narrowing. The risk for ACL injuries is very high when NWI is ≤0.25. Preventive measures for the unaffected knee are required for patients with a narrow intercondylar notch.

Therapeutic effect of Photodynamic therapy using Na-Pheophorbide a on osteomyelitis models in rats

OBJECTIVE In this study, we examined the therapeutic effect of photodynamic therapy (PDT) using the photosensitizer Na-Pheophorbide a (Na-Phde a) on osteomyelitis models in rats. BACKGROUND Osteomyelitis is one of the most serious infectious problems in the orthopedic field. Recently, as a new clinical approach against septic arthritis, an experimental in vivo and in vitro model for the inactivation of methicillin-resistant-Staphylococcus aureus by PDT using Na-Phde a has been developed. METHODS Methicillin-sensitive Staphylococcus aureus (MSSA) was injected into the tibia of the rats to create osteomyelitis models (n = 10, 10 legs). A total of 560 μmol/l of Na-Phde a solution was injected into five of these tibial osteomyelitis models (five legs) 48 h after the initial MSSA infection. Sixty minutes after the Na-Phde a injection, a semiconductor laser (125 mW, 670 nm) was used to irradiate the models for 10 min with a total energy of 93.8 J/mm(2). As a control group, five rats (five legs) were treated with a phosphate buffered saline injection at 48 h after MSSA infection. Weight and leg perimeter changes were plotted. Bacterial growth, histological examination and radiological examination were evaluated at 14 days after initial treatment. RESULTS PDT with Na-Phde a significantly prevented leg swelling. In the PDT group, bone destruction owing to osteomyelitis was inhibited not only histologically but also radiographically. CONCLUSIONS The results in these experiments show that PDT using Na-Phde a improved osteomyelitis in rats. This suggests that PDT using Na- Phde a can be a useful treatment for osteomyelitis.

Bactericidal Effect of Photodynamic Therapy Using Na-Pheophorbide a: Evaluation of Adequate Light Source

OBJECTIVE To evaluate the efficacy of photodynamic therapy (PDT) against methicillin resistant-Staphylococcus aureus (MRSA) by selecting different light sources for irradiation and combining them with the photosensitizer Na-Pheophorbide a (Na-Phde a). BACKGROUND The treatment of drug-resistant bacterial infection is a serious issue. Recently, as a new clinical approach against septic arthritis, an experimental in vivo and in vitro model for the inactivation of MRSA by PDT using the photosensitizer Na-Phde a has been developed. MATERIALS AND METHODS Na-Phde a solution (280 micromol/L) was mixed with MRSA strain bacterial inoculum. After 60 minutes, light was irradiated for 30 minutes using the following light sources: GaA1p semiconductor laser (300 mW, 670 nm), halogen lamp (75 W), xenon lamp (300 W) and fluorescent lamp (27 W). Bacterial growth was evaluated after 24 hours incubation in a blood agar culture. RESULTS The semiconductor laser and halogen lamp groups showed perfect bactericidal effects after PDT. The xenon lamp and fluorescent lamp groups showed partial bactericidal effects. CONCLUSIONS The results of this experiment showed that PDT using the combination of Na-Phde a with a semiconductor laser or halogen lamp showed a better bactericidal performance than with xenon or fluorescent lamps. These findings indicated that PDT using Na-Phde a could be a useful treatment for septic arthritis and soft tissue infection.

The importance of Blumensaat’s line morphology for accurate femoral ACL footprint evaluation using the quadrant method

PurposeThe purpose of this study was to evaluate the difference in the center position of the ACL footprint based on grid placement using the quadrant method according to the morphological variations of the Blumensaat’s line.MethodsFifty-nine non-paired human cadaver knees were used. The ACL was cut in the middle, and the femoral bone was cut at the most proximal point of the femoral notch, and the digital images were evaluated using Image J software. The femoral ACL footprint was periphery outlined and the center position was automatically measured. Following Iriuchishima’s classification, the morphology of the Blumensaat’s line was classified into straight, small hill, and large hill types. From the images, grid quadrants were placed as: Grid (1) without consideration of hill existence and not including the chondral lesion. Grid (2) without consideration of hill existence and including the chondral lesion. Grid (3) with consideration of hill existence and not including the chondral lesion. Grid (4) with consideration of hill existence and including the chondral lesion.ResultsThe straight type consisted of 19 knees, the small hill type 13 knees, and the large hill type 27 knees. Depending on the quadrant grid placement, significant center position difference was observed both in the shallow–deep, and high–low direction. When hill existence was considered, the center position of the ACL was significantly changed to a high position.ConclusionThe center position of the ACL footprint exhibited significant differences according to Blumensaat’s line morphology. For clinical relevance, when ACL surgery is performed in knees with small or large hill type variations, surgeons should pay close attention to femoral tunnel evaluation and placement, especially when using the quadrant method.