Shinichi Yoshiya

Medial Collateral Ligament Reconstruction Using Autogenous Hamstring Tendons Technique and Results in Initial Cases

Background Although various surgical procedures that attempt to restore the function of the medial collateral ligament have been reported, none have achieved consistently satisfactory results. Hypothesis Our reconstructive procedure using autogenous semitendinosus and gracilis tendons yields improved results compared with conventional procedures. Study Design Case series. Level of evidence, 4. Method In our surgical procedure, autogenous semitendinosus and gracilis tendons were used to anatomically reconstruct the anterior longitudinal component of the superficial medial collateral ligament. From April 1995 through December 2000, 27 patients with symptomatic medial instability underwent this surgical procedure. The majority of the subjects were diagnosed with combined cruciate ligament injuries, necessitating concomitant cruciate ligament reconstructions. Of these 27 patients, 24 were evaluated after a minimum period of 2 years, with a mean follow-up period of 27 months (range, 24-48 months). Results At follow-up, medial stability, as well as postoperative range of motion in all patients, was graded as normal or nearly normal according to the International Knee Documentation Committee evaluation system. No significant postoperative complications were encountered. Conclusion Although this is a short-term follow-up study involving a small number of cases, we considered our procedure to be an effective method of surgically restoring the function of the medial collateral ligament.

Meniscal repair using fibrin sealant and endothelial cell growth factor An experimental study in dogs

The effect of fibrin sealant and endothelial cell growth factor on the healing of defects of the avascular portion of canine menisci was investigated in 30 menisci of 15 adult mongrel dogs. The defects were treated in one of three ways: Group 1, the defect was left empty; Group 2, the defect was filled with fibrin sealant; and Group 3, the defect was filled with fibrin sealant and endothelial cell growth factor. The healing process was evaluated macroscopically and histologically at intervals of 1, 2, 6, 12, and 24 weeks. The average percentage of each defect that was filled with connective tissue was 5% in Group 1, 76.6% in Group 2, and 89.4% in Group 3. In the early phase of this repair, the extrinsic pannus-like tissue that contained many capillary vessels extended from the meniscosynovial junction into the defect. Sub sequently, organized fibrous connective tissue was formed, which had changed to cartilaginous tissue at 12 to 24 weeks. The combination of fibrin sealant and endothelial cell growth factor enhanced the neovascu larization and formation of granulation tissue, which accounted for the increased healing level in the avas cular portion of the meniscus.

Effect of basic fibroblast growth factor on the healing of defects in the canine anterior cruciate ligament.

Abstract The effect of basic fibroblast growth factor (bFGF) on the healing of partial anterior cruciate ligament (ACL) lacerations was investigated in 17 adult mongrel canines. The defect was created in the midsubstance of both ACLs using a biopsy punch. In the bFGF group, a bFGF-impregnated pellet was sutured to the infrapatellar fat pad close to the defect. In the control group, the same pellet without bFGF was used. The healing process was evaluated macroscopically and histologically at 1, 3, 6, and 24 weeks postoperatively. In the bFGF group, a pannus-like tissue which contained abundant blood vessels extended into the defect from the adjacent synovial tissue in the early postoperative phase. Histological examination of the tissue which filled the defect revealed initial remodeling processes with a decreased number of cells and better orientation of the collagen fibers at 6–24 weeks. On the other hand, in the control group, poor healing processes were observed at each examination period. This study demonstrated that the application of a bFGF-impregnated pellet may enhance the healing potential of a partially injured ACL. Enhanced neovascularization and the formation of granulation tissue induced by bFGF early in the healing process accounted for the increased healing response.

Light and electron microscopic study of remodeling and maturation process in autogenous graft for anterior cruciate ligament reconstruction

We evaluated the remodeling process of autogenous patellar tendon graft for anterior cruciate ligament (ACL) reconstruction by means of light microscopic (LM) and electron microscopic (EM) examinations from the biopsy specimens obtained at the time of second-look arthroscopy. Twenty-one patients were examined at various times postoperatively (from 6 weeks to 15 months, mean 9.5 months), and the results were correlated with the morphology of normal patellar tendon and normal ACL. Our study showed that the graft was revascularized in the early postoperative period, fibroblastic remodeling took place, and the graft obtained gross similarity to the original ACL on their arthroscopic and LM appearances at approximately 1 year postoperatively. However, EM study showed that at both approximately 6 months and 1 year postoperatively the grafts consisted equally of active fibroblasts with a higher cytoplasm-to-nucleus ratio compared with normal ACL. Collagen fibrils of these grafts were of uniformly small diameter compared with normal patellar tendon and ACL. Our results with ultrastructural study suggest that the grafts were still immature even at 1 year postoperatively.

Evaluation of Hamstring Strength and Tendon Regrowth After Harvesting for Anterior Cruciate Ligament Reconstruction

Background It is generally thought that tissue regeneration and good functional recovery can be expected after anterior cruciate ligament reconstruction using the hamstring tendons. However, persistent strength deficit in deep knee flexion has also been reported. Hypothesis Morphologic regeneration of the harvested hamstring tendon is not necessarily associated with its functional recovery. Study Design Retrospective follow-up study. Method Twenty-eight patients who underwent anterior cruciate ligament reconstruction with hamstring graft were evaluated after a minimum period of 2 years. Status of tendon regrowth was assessed by magnetic resonance imaging. To specifically analyze the functional deficit after graft harvest, the isometric hamstring strength was examined in a sitting position at 90° of flexion and a prone position at 90° and 110° of flexion. Then, the strength data were correlated with the extent of tendon regeneration. Results In 22 of the 28 patients, a regrowth of the semitendinosus tendon was found, whereas regeneration of the gracilis tendon was observed in 13 patients. In the evaluation of hamstring strength, the isometric peak torque was reduced to 86.2%, 54.6%, and 49.1%, respectively, in the aforementioned 3 postures as compared with the contralateral side. Conclusions Significant functional deficit of hamstring strength remains regardless of morphologic regeneration.

A Comparison of Bone–Patellar Tendon–Bone and Bone–Hamstring Tendon–Bone Autografts for Anterior Cruciate Ligament Reconstruction

Background Most of the previous comparative studies between patellar tendon and hamstring tendon anterior cruciate ligament grafts compared grafts of different constructs fixed with different methods. Purpose To compare patellar tendon and hamstring tendon grafts with the same fixation method used to reconstruct the anterior cruciate ligament. Study Design Randomized controlled trial; Level of evidence, 1. Methods During the reconstructive procedure, the hamstring tendon graft was prepared as a bone-hamstring-bone graft; both bone-patellar tendon-bone and bone-hamstring-bone grafts were fixed with interference screws. Eighty consecutive patients who underwent anterior cruciate ligament reconstruction were randomly assigned to either bone-patellar tendon-bone or bone-hamstring-bone groups. Follow-up examinations were performed for at least 5 years postoperatively. Seventy-two of the 80 patients (37 patients in the bone-patellar tendon-bone group and 35 in the bone-hamstring-bone group) were evaluated, with a mean follow-up period of 87.0 and 80.8 months, respectively. Follow-up examinations were performed using the International Knee Documentation Committee knee ligament standard and subjective knee forms. Results The mean KT-1000 arthrometer evaluation results showed no significant difference between the bone-patellar tendon-bone and bone-hamstring-bone groups (1.2 ± 2.1 mm and 1.7 ± 1.4 mm, respectively; P =. 24). However, symptoms related to graft harvest (anterior kneeling pain) were more frequently observed in the bone-patellar tendon-bone group, and unsatisfactory results were correlated with severe kneeling pain in 3 patients from this group (P =. 0056). Significant hamstring muscle weakness without complaint of functional deficit was found in the bone-hamstring-bone group (P =. 0045). Conclusion Bone-hamstring-bone grafts were shown to reduce the risk of problems at the graft harvest site compared to bone-patellar tendon-bone grafts, with comparable results in the remaining clinical parameters tested.

Evaluation of functional deficits determined by four different hop tests in patients with anterior cruciate ligament deficiency

Abstract The purpose of this study was to analyze the validity of the newly designed functional ability test (FAT) for the normal population and patients with deficiency of the anterior cruciate ligament (ACL). The FAT consists of four tests: the figure-of-eight hop, the up-down hop, the side hop, and the single hop. Sixty control subjects and 50 patients with unilateral ACL deficiency were tested. In the control group, the values measured were significantly different between males and females in all of the tests. On the other hand, when left/right difference values were compared, no significant difference was found between males and females in any of the tests. More than 95% of control group exhibited symmetrical function in each part of the FAT, whereas in the ACL-deficient group, the percentage of patients who showed abnormal symmetry was 68% in the figure-of-eight hop, 58% in the up-down hop, 44% in the side hop, and 42% in the single hop. The percentage of ACL-deficient patients with functional asymmetry in at least one of the four tests was 82%. The FAT was found to be useful in evaluating lower limb function in ACL-deficient patients.

Prosthetic alignment and sizing in computer-assisted total knee arthroplasty

We implanted 60 posterior stabilized total knee prostheses (P.F.C. Sigma, DePuy, Warsaw, USA). In 30 cases, we used a CT-free navigation system (Vector Vision, Brain LAB, Heimstetten, Germany), and in 30 matched-paired controls, we used a conventional manual implantation. We compared postoperative long-leg radiographs in the two groups. The results revealed a significant difference in favor of navigation. In addition, we compared the preoperative anteroposterior dimension of the femoral condyle with the postoperative value. While there were no significant differences in the preoperative anteroposterior dimension of the femoral condyle between the two groups, the postoperative value in the navigation group was significantly larger than that of the preoperative value. Therefore, surgeons using navigation systems should guard against the possibility of oversizing when determining the size of the femoral component.RésuméNous avons implanté 60 prothèses totales postéro-stabilisées du genou (P.F.C. Sigma, DePuy). Dans 30 cas nous avons utilisé un système de navigation sans scanner (Vector vision R, Laboratoire du Cerveau, Heimstetten, Allemagne) et dans 30 contrôles appairés nous avons utilisé une implantation manuelle habituelle. Nous avons comparé les grandes radiographies postopératoires des membres inférieurs dans les deux groupes. Les résultats ont révélé une différence notable en faveur de la navigation. De plus nous avons comparé la dimension antéro-postérieure du condyle fémoral avant l’intervention avec la valeur postopératoire. Tandis qu’il n’y avait pas de différence notable dans la dimension antéro-postérieure préopératoire du condyle fémoral entre les deux groupes, la valeur postopératoire dans le groupe de la navigation était nettement plus grande que la valeur préopératoire. Par conséquent les chirurgiens qui utilisent des systèmes de navigation doivent prendre garde à ne pas implanter un composant fémoral sur-dimensionné.

Localization of growth factors in the reconstructed anterior cruciate ligament: immunohistological study in dogs

Abstract This study was designed to examine localization of the growth factors in the autogenous patellar tendon graft used to reconstruct the anterior cruciate ligament (ACL) in the canine model. Among the various growth factors, basic fibroblast growth factor, transforming growth factor-β1, and platelet-derived growth factor were selected for analysis as potential factors that regulate graft remodeling processes. In the control patellar tendon and the ACL only basic fibroblast growth factor was positively stained. In the reconstructed graft increased levels of staining for all the three factors were observed in the early postoperative period, reaching the greatest expression 3 weeks after implantation. Thereafter immunoreactivity of these growth factors decreased and returned to the preoperative levels, which were similar to that of the control ACL 12 weeks postoperatively. This rapid reduction in the level of their localization indicates that once the extrinsic cells are infiltrated to the graft and revascularization completed, these growth factors may have less significance for subsequent remodeling.

Efficacy of the axially loaded pivot shift test for the diagnosis of a meniscal tear

Abstract Although magnetic resonance imaging (MRI) has improved the diagnostic accuracy of meniscal pathology, the authors believe that physical examination remains essential to the evaluation of knee pathology. In this study, the diagnostic accuracy of five clinical tests for meniscal pathology was prospectively evaluated in 160 patients, who thereafter underwent arthroscopy. 69% (109 knees) of the knees tested had associated ACL deficiency. There were 144 meniscal lesions in 130 of the 160 knees which were examined. The sensitivity of the tests was lower than the specificity. Conventional tests such as McMurray and Apley tests showed a low accuracy rate of 45% and 28% respectively. The diagnostic value of the axially loaded pivot shift test was significantly higher, indicating that this remains a useful diagnostic aid.Résumé  Ils évaluent prospectivement la précision diagnostique de cinq différentes épreuves cliniques employées pour confirmer des déchirures méniscales chez des 160 sujets ayant subi une évaluation arthroscopique. Soixante–neuf pour cent (109) des genoux contrôlés par les auteurs présentaient une carence arthrocinétique complexe. Ils ont observé 144 déchirures méniscales sur 130 genoux. Toutes les épreuves cliniques présentaient généralement une sensibilité inférieure à leur spécificité. Quant au test de déplacement du pivot sous charge axiale, le fait que sa valeur diagnostique est, dans l’ensemble, significativement supérieure à celle des autres manoeuvres diagnostiques en fait un supplément de choix dans l’arsenal diagnostique.