Masanori Terauchi

Proprioception and performance after anterior cruciate ligament rupture

The aim of this study was to investigate the characteristics of proprioception in patients with an anaterior-cruciate-ligament (ACL)-injured knee and to determine whether there is a correlation between proprioception and performance. We studied 32 patients with unilateral isolated ACL ruptures. Proprioception of the knee was evaluated by examining the joint position sense. Functional performance was evaluated with the one-leg hop (OLH) and one-leg vertical jump (OLV) tests. The mean error angle of the joint position sense was 3.6±1.5° on the intact side and 5.2±1.9° on the injured side. The joint position sense was thus clearly reduced on the injured side (p<0.05). The distance of jumping in the OLH test and the height of jumping in the OLV test was also clearly reduced on the injured side compared with that on the intact side (p<0.01) both with and without visual control. Moreover, we found a significant correlation between proprioception and performance in the ACL-injured knees, and this correlation was more distinct with visual deprivation. In conclusion, decreased proprioception in patients with ACL deficiency reduced their functional ability.RésuméLe but de cette étude était d’étudier les caractéristiques de proprioception chez les malades avec une lésion du LCA, et déterminer s’il y avait une corrélation entre proprioception et performance. Nous avons étudié 32 malades avec une rupture isolée unilatérale du LCA. La proprioception du genou a été évalué en examinant le sens des positions de l’articulation. La fonction a été évaluée avec le saut à cloche-pied (OLH) et saut vertical unipodal (OLV). L’angle moyen d’erreur de position était 3,6±1,5° sur le côté intact et 5,2±1,9° sur le côté blessé. Le sens de position était donc notablement réduit du côté blessé (p<0.05). La distance de saut dans l’épreuve OLH et la hauteur du saut dans l’épreuve OLV ont aussi été réduite du côté blessé comparé avec le côté intact (p<0.01) les deux avec et sans contrôle visuel. De plus, nous avons trouvé une corrélation certaine entre proprioception et performance dans les genoux avec lésion du LCA, et cette corrélation était encore plus nette avec privation visuelle. En conclusion, la diminution de la proprioception chez les malades avec une insuffisance du LCA à réduit leur capacité fonctionnelle.

Sagittal Alignment of the Knee and Its Relationship to Noncontact Anterior Cruciate Ligament Injuries

Background: Knee hyperextension and tibial posterior slope are related to sagittal alignment of the knee. The relationship of sagittal alignment to noncontact anterior cruciate ligament (ACL) injuries has been reported with conflicting results. Purpose: To determine whether there is a difference in sagittal alignment of the knee between an ACL-deficient group and a negative control group and to find risk factors contributing to noncontact ACL injuries. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Magnetic resonance images of the knee in full extension were acquired in the patient group, which consisted of 33 male and 40 female patients with noncontact ACL injuries, and in the negative control group, which consisted of 28 male and 30 female participants. Three angles were measured: the angle between the femoral axis and the tibial axis, designated as the extension angle; the femoral plateau angle, between the femoral axis and a line tangent to the concave profile of the medial tibial plateau (P line); and the tibial posterior slope angle, 90° minus the angle made by the intersection of the tibial axis and the P line. Results: In the female group, the femoral plateau angle and the tibial posterior slope angle were significantly larger in the ACL-deficient patients than in the negative control group, although these differences were not seen in the male group. In the female subjects, a negative correlation between the extension angle and the tibial posterior slope angle was seen in the ACL-deficient group, suggesting that knees with hyperextension had a small tibial posterior slope, whereas knees without hyperextension had a large tibial posterior slope. Conclusion: There were 2 types of large femoral plateau angles: one had its origin in an increasing tibial posterior slope; the other resulted from hyperextension of the knee. Large posterior tibial slope and hyperextension are both correlated with noncontact ACL injury in women.

Spontaneous osteonecrosis of the knee: HISTOPATHOLOGICAL DIFFERENCES BETWEEN EARLY AND PROGRESSIVE CASES

We prospectively examined the physical and imaging findings, including MRI, of 23 patients with spontaneous osteonecrosis of the knee after obtaining informed consent to acquire tissue specimens at surgery. There were four men and 19 women, with a mean age of 67.5 years (58 to 77). Plain radiographs were designated as stages 1, 2, 3 or 4 according to the classification of Koshino. Five knees were classified as stage 1, five as stage 2, seven as stage 3 and six as stage 4. The histological specimens were stained with haematoxylin and eosin and tetrachrome. In the early stages of the condition, a subchondral fracture was noted in the absence of any features of osteonecrosis, whereas in advanced stages, osteonecrotic lesions were confined to the area distal to the site of the fracture which showed impaired healing. In such cases, formation of cartilage and fibrous tissue, occurred indicating delayed or nonunion. These findings strongly suggest that the histopathology at each stage of spontaneous osteonecrosis is characterised by different types of repair reaction for subchondral fractures.

The management of medial ligament tears in patients with combined anterior cruciate and medial ligament lesions

Abstract The management of patients with combined medial collateral (MCL) and anterior cruciate (ACL) rupture remains controversial. We studied 25 such patients who elected to have the ACL lesion treated conservatively; 14 underwent MCL repair with early mobilization and 11 were treated with immobilization for two weeks. The mean follow up was 5.9 years (2 to 11). There was no difference in the clinical assessment of ligamentous laxity, KT-1000 measurements or Tegner activity scores between the two groups but there were significantly higher Lysholm function scores in the operated group.Résumé Le traitement optimal des cas associant des lésions du ligament croisé antérieur (ACL) à des lésions médiales collatérales (MCL) est controversé. Nous avons réalisé une étude sur le suivi du traitement de telles lésions dans le but d’évaluer si le traitement opératoire des déchirures de MCL peut apporter une amélioration des résultats fonctionnels pour des patients choisissant de ne pas subir une reconstruction de ACL. Notre étude portait sur 14 patients ayant subi une reconstruction du MCL et 11 patients traités sans opération. Nous n’avons pas observé de différences significatives entre les deux groupes pour les tests de relâchement manuel, ni pour les mesures KT-1000, ni pour les niveaux d’activité de Tegner. En revanche les patients du groupe opératoire ont obtenu un meilleur score fonctionnel de Lysholm.

The influence of osteoporosis on varus osteoarthritis of the knee

We studied 37 patients with varus osteoarthritis of the knee to determine the influence of the bone mineral density (BMD) on the varus deformity. There were 15 men (21 knees) and 22 women (38 knees). The mean age of the men was 69 years and of the women 68 years. BMD was measured in the L1-L4 spinal region using dual X-ray absorptiometry. In the women a low level of BMD was associated with varus deformity originating at the proximal tibia, but a high level was predominantly linked with deformity originating in the joint space. Similar findings were obtained in the men. Our results suggest that a low BMD predisposes to trabecular microfractures and consequently increased stress on the articular cartilage. A low BMD does not preclude osteoarthritic change in the knee.

Varus inclination of the distal femur and high tibial osteotomy

We have analysed retrospectively the relationship between the axial parameters of alignment of the lower limb and the recurrence of varus deformity after high tibial osteotomy. We studied 29 patients (37 knees) with a mean age at surgery of 66 years. The mean follow-up was for 7.4 years (5 to 10.5). Recurrence of varus deformity was defined as an increase in the femorotibial angle of 3 degrees or more, compared with that obtained six months after the operation. There were four patients (four knees) with recurrence of varus deformity. They had a greater varus inclination of the distal femur than those without varus recurrence. An association between varus inclination of the distal femur and horizontal obliquity of the joint surface was observed. Excessive obliquity prevents the shift of weight-bearing to the lateral compartment, and may cause a recurrence of varus deformity after high tibial osteotomy.

The Importance of Tibial Tunnel Placement in Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE The purposes of this study were to measure the anterior edge of the tibial tunnel after anatomic anterior cruciate ligament (ACL) reconstruction on lateral radiographs and to determine whether the difference in tibial tunnel placement affects postoperative outcomes. METHODS For 60 patients who underwent anatomic double-bundle ACL reconstruction with semitendinosus tendon, we evaluated the side-to-side difference in anterior tibial translation on stress radiographs, as well as rotational stability by the pivot-shift test, 2 years after surgery. Loss of extension (LOE) was evaluated on lateral radiographs of both knees in full extension, and graft integrity was assessed during second-look arthroscopy 1 to 2 years after surgery. On true lateral radiographs, we measured the anterior placement percentage of the tibial tunnel using the method described by Amis and Jakob. The cutoff value was set at 25% of the mean value of the anterior edge of the ACL that Amis and Jakob reported, and patients were divided into 2 groups (27 in the anterior group and 33 in the posterior group). Postoperative clinical results were compared between the groups. RESULTS The mean anterior placement percentage was 26.0% ± 4.1%. The postoperative mean side-to-side difference was 1.4 ± 2.7 mm for the anterior group and 3.0 ± 2.7 mm for the posterior group, a significant difference (P < .05). The positive ratio of the pivot-shift test was not significantly different between groups (P > .05). Mean LOE in the anterior and posterior groups was 0.9° ± 3.0° and -0.8° ± 4.0°, respectively; the difference was not significant (P > .05). Five of 27 knees in the anterior group and 5 of 33 knees in the posterior group had superficial graft laceration or elongation, which was not significantly different (P > .05). CONCLUSIONS Anterior placement of the tibial tunnel in anatomic double-bundle ACL reconstruction leads to better anterior knee stability than posterior placement does. Anterior tibial tunnel placement inside the footprint did not increase the incidence of LOE and graft failure. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Untreated acute anterior cruciate ligament tears of the knee: progression and the influence of associated injuries.

Arthroscopy was performed on 53 consecutive patients with acutely torn ACL within two weeks after the initial injury. Arthrography was performed on 42 of the 53 patients prior to arthroscopy. Four Segonds fractures, twenty-six meniscus tears (eight medial, eighteen lateral) and nineteen medial collateral ligament (MCL) ruptures were revealed. One medial meniscectomy was performed under arthroscopy, and ten MCL tears were repaired in the acute phase. No surgical procedure was done on the torn ACL, but three excisions of ACL stubs were performed due to a restriction of full extension. The patients were reexamined clinically and radiographically after a period of from 3 years 7 months to 11 years 1 month, averaging 6 years 2 months. Four late meniscectomies were performed on the medial menisci in the chronic phase. Anterior translations of the tibia and knee rating scores of the patients with MCL tears and with Segonds fractures did not differ from those of the others. Anterior translations of the tibia in patients with medial meniscectomies increased (P<0.05), and their functional scores significantly decreased (P<0.01) more than those of the other patients. Patients with repaired MCL tears showed significantly higher functional scores than those of the patients with unrepaired MCL ruptures (P<0.05).

Relationship Between Femoral Component Rotation and Total Knee Flexion Gap Balance on Modified Axial Radiographs

Using modified axial radiographs, we investigated the relationship between femoral component rotation and flexion gap balance in 70 consecutive knees with varus osteoarthritis 1 year after they underwent cruciate-ligament-retaining total knee arthroplasty with the measured resection technique. We measured (1) the condylar twist angle, defined as the angle between the posterior condylar axis and the clinical epicondylar axis, and (2) the liftoff angle (LOA), defined as the angle between the posterior condylar axis and the tibial cutting surface. There was a significant positive correlation between the postoperative condylar twist angle (mean, 2.6°) and the postoperative LOA (mean, 1.8°). Our data suggest that a more accurate method of identifying the clinical epicondylar axis would lead to a smaller LOA as measured on modified axial radiographs.

Clinical and arthroscopic findings of acute anterior cruciate ligament tears of the knee.

Clinical, arthrographic, and arthroscopic findings in 53 patients with acutely torn anterior cruciate ligaments (ACLs) were documented. Arthroscopy and instability tests under anesthesia were performed on all patients within 2 weeks after the initial injury. Twenty-three patients complained of extension blocks, and localized tenderness on the medial side was revealed in 26 patients at the initial examination. Aspiration from joints exhibited hemarthrosis in 52 patients. Arthroscopy revealed ACL ruptures in all patients. Four Segonds fractures, 26 meniscus tears (8 medial and 18 lateral), 1 osteochondral fracture, and 19 medial collateral ligament ruptures were revealed. Arthroscopy detected only 1 of the 5 ruptures of the posteromedial corner of the medial meniscus, which were noted on arthrography. Three ACL stumps were protruding among the femorotibial joint, which seemed to be restricting full extension. Statistical analysis showed that tenderness on the medial side was not revealed more frequently in knees with medial collateral ligament injuries than in the others. The volume of aspirated fluids in knees with no leakage in arthrography significantly increased over those with leakages (p < 0.05). Diagnosis of ACL injuries should be completed by clinical, arthrographic, and arthroscopic examinations.