Emin Taşkıran

Analysis of meniscal and chondral lesions accompanying anterior cruciate ligament tears: relationship with age, time from injury, and level of sport

The purposes of this multi-center study were: (a) to document the location and type of meniscal and chondral lesions that accompany anterior cruciate ligament (ACL) tears, and (b) to test for possible relationships between these lesions and patient age, time from initial injury (TFI), and sports level (i.e., recreation, amateur, professional, and national). The cases of 764 patients with ACL tears who underwent arthroscopy for the first time were retrospectively analyzed. The group included 684 males and 80 females of mean age 27 years (range 14–59 years). The mean TFI was 19.8 months (range 0.2–360 months). Eighty-seven percent of the group engaged in regular sporting activity. Thirty-seven percent had medial meniscal tears, 16% had lateral meniscal tears, and 20% had tears of both menisci. The most common tear types were longitudinal tears in the posterior and middle horns of both menisci. Tears of the lateral meniscus were more centrally located than those of the medial meniscus. Incomplete tears and radial tears were significantly more common in the lateral meniscus. Nineteen percent of the knees had one or more chondral lesions. Sixty percent of the chondral lesions were located in the medial tibio-femoral compartment. Patient age was statistically associated with presence of a medial meniscal tear, presence of a grade 3 or 4 chondral lesion, and presence of a complex tear of the medial meniscus. Sports level was not statistically related to any of the parameters studied. The odds of having a medial meniscal tear at 2 to 5 years TFI were 2.2 times higher than the odds in the first year post-injury, and the odds at >5 years were 5.9 times higher than at 0 to 12 months TFI. The frequency of lateral meniscal tear remained fairly constant at 2 years TFI. The odds of having a grade 3 or 4 chondral lesion were 2.7 times greater at 2 to 5 years TFI than they were at 1 year post-injury, and these odds increased to 4.7 when patients at >5 years TFI were compared to those in the 2 to 5 years category. Multivariate analysis demonstrated that TFI and age were equally important predictors of lateral meniscal tears and of grade 3 or 4 chondral lesions; however, TFI was the better predictor of medial meniscal tear.

Tensile properties of the superior glenohumeral and coracohumeral ligaments

Recent evidence has shown that the superior glenohumeral ligament (SGHL) and coracohumeral ligament (CHL) are important static stabilizers. To clarify the function of these two ligaments, we studied their tensile properties with bone-ligament-bone complexes from fresh-frozen shoulders, 10 SGHLs and 10 CHLs. Each ligaments cross-sectional area was measured, and uniaxial tensile testing of each complex was performed. The stiffness, ultimate load, percent elongation, and energy absorbed to failure of each bone-ligament-bone complex were derived from its load-elongation curve. The cross-sectional area of the coracohumeral ligament was significantly greater than that of the superior glenohumeral ligament of their midportions (CHL, 53.7 +/- 3.2 mm2 vs. SGHL, 11.3 +/- 1.6 mm2, p < 0.05). Results also reveal significant differences between the tensile properties for the two ligaments, with the coracohumeral ligament possessing greater stiffness (CHL, 36.7 +/- 5.9 N/mm vs. SGHL, 17.4 +/- 1.5 N/mm, p < 0.05) and ultimate load (CHL, 359.8 +/- 40.3 N vs. SGHL, 101.9 +/- 11.5 N, p < 0.05) than the superior glenohumeral ligament. Our findings confirm that the coracohumeral ligament is an important capsuloligamentous structure of the glenohumeral joint.

Differential Corticomotor Control of a Muscle Adjacent to a Painful Joint

Objective. To assess the effects of chronic knee pain on neural control of the nearby quadriceps muscle. Methods. Motor-evoked potentials (MEP) in response to transcranial magnetic stimulation (TMS) of the motor cortex, maximal M responses, patellar tendon responses, and EMG activity during maximal isometric contraction were recorded from the right vastus medialis oblique (VMO) and vastus lateralis (VL) muscles in 13 patients with chronic patellofemoral pain syndrome (PPS) and 13 healthy volunteers. MEP and maximal M responses were also recorded from the right extensor digitorum brevis (EDB) muscle. Results. MEP amplitudes from VMO and VL were larger in patients with PPS than in controls. On the other hand, maximal M responses, EMG activity with maximal voluntary contraction, and tendon responses were smaller in patients than in controls. Motor-evoked responses and maximal M responses of the EDB muscle did not show significant difference between the 2 groups. Conclusions. These results indicate that chronic knee pain modulates central motor control of an adjacent muscle.

Mechanical properties of the long head of the biceps tendon

In this study, the geometric and mechanical properties of the long head of the biceps tendon were determined in order to elucidate its role in shoulder stability. We used a laser-micrometer system to measure the cross-sectional area and shape of seven fresh-frozen tendons at three levels: proximal, middle, and distal levels. The cross-sectional areas were found to be 22.7±9.3 mm2, 22.7±3.5 mm2, and 10.8±2.7 mm2, respectively. While statistically significant differences could not be demonstrated between the magnitudes of the areas, a consistent difference in shape was noted between the proximal and middle levels, the tendon being flatter as it progressed over the humeral head and more triangular as it passed through the bicipital groove. We then performed cyclic relaxation tests and uniaxial tensile testing of the tendons which revealed a cyclic stress relaxation of 18±4% over ten cycles. All tensile failures occurred within the midportion of the tendon substance. Additionally, the modulus was calculated between 3% and 6% strain and found to be 421±212 MPa, while the ultimate tensile strength, ultimate strain, and strain energy density were 32.5±5.3 MPa, 10.1±2.7%, and 1.9±0.4 MPa, respectively. These mechanical properties of the long head of the biceps tendon are of the same order of magnitude as tendons from other joints. The high stiffness of this tendon indicates that it has an ability to support the large load transferred to it by the muscle and to act as a humeral head depressor.

Effect of the vastus medialis obliquus on the patellofemoral joint

Abstract In this study, the effect of dynamic stabilizers on the patellofemoral (PF) joint was investigated in normal volunteers (group I) and in patients with patellar pain (group II) or instability (group III) by using computed tomography (CT) analysis and integrated electromyography (iEMG) of the quadriceps muscle. Nine subjects (16 knees) from group I, 10 patients (12 knees) from group II and 8 patients (12 knees) from group III were included in the study. CT scans of the PF joint with quadriceps contracted (QC) and uncontracted (QU) and iEMG of vastus medialis obliquus (VMO), vastus lateralis (VL) and rectus femoris (RF) were obtained with the aid of a specially designed jig at 0°, 15°, 30° and 45° of knee flexion. The same muscle contraction pattern simulating closed kinetic chain exercise was used for both CT and iEMG. The difference between the congruence angles (CA) and tilt angles (PTA) in QC and QU positions and VMO:VL ratio from the iEMG were calculated separately for each flexion angle. CA was increased in all groups with quadriceps contraction at 0° and 15° of flexion. PTA was decreased in group I and increased in groups II and III with quadriceps contraction at the same flexion angles. This difference was statistically significant in group III at 0° and 15° of flexion. Quadriceps contraction did not affect the patellar position significantly even in the instability group at 45° of flexion. In all flexion angles the balanced VMO:VL activity ratio was observed only in group I. In the other goups, VL activity was higher than VMO activity except at 45° of flexion. These findings do not support the hypothesis of dominant centralizing effect of VMO on the patella in extension, but the effect of the VMO may be more clearly demonstrated by measuring PTA in both QC and QU positions.

Articular cartilage homeostasis after anterior cruciate ligament reconstruction

Abstract Several factors may be responsible for osteoarthritis after anterior cruciate ligament (ACL) reconstruction. The detrimental effect of the surgical technique may explain part of the progression of the pathologic process. In this study, the effect of ACL reconstruction on articular cartilage was investigated by measuring proteoglycan fragments (PF) in synovial fluid collected from patients who had undergone this operation. Synovial samples were obtained from 44 patients with chronic ACL deficiency aged 26 ± 7 years preoperatively, and from some of them, samples were collected for monitoring at 1 month (n = 22), 3 months (n = 17), 6 months (n = 18) and 12s month (n = 18). Synovial fluid taken from 12 contralateral asymptomatic knees of 12 patients (not necessarily opposite knees of ACL-deficient cases) served as controls. Preoperative values were significantly larger than controls (P < 0.05). PF level reached its maximum value in the 1st month (P < 0.05) and then gradually decreased. It was significantly lower than preoperative values at 6 and 12 months but still greater than controls (P < 0.05). It seems that surgical trauma affects cartilage metabolism for the first 3 months postoperatively. Although reconstruction of the ACL contributes to articular cartilage homeostasis, a complete return to normal values cannot be achieved in 1st postoperative year at least in knees with chronic ACL deficiency. Long-term monitoring is needed to see whether these findings are early signs of osteoarthritis. Further studies may more clearly demonstrate the effect of the surgical procedure on knees with acute and subacute ACL deficiency.

Exogenously administered adenosine attenuates renal damage in streptozotocin-induced diabetic rats.

Abstract Background: Diabetic nephropathy (DNP) is one of the most serious complications of diabetes mellitus (DM). In the present study, we investigated the potential of adenosine as a therapeutic candidate for preventing DNP. Methods: Twenty-one adult male rats were included in the study. Fourteen rats were administered a single dose of 60 mg/kg streptozotocin (STZ) to induce diabetes. Seven rats served as normal control group. Diabetic rats were randomly divided into two groups: one group was treated with 1 mL/kg saline/day (DM + saline) and the other group was treated with 5 mg/kg/day adenosine (DM + adenosine) for 6 weeks. After 6 weeks, biochemical parameters including urea, creatinine, blood urea nitrogen (BUN), kidney injury molecule-1 (KIM-1) and tumor necrosis factor-α (TNF-α) were measured in plasma samples. Also, kidneys were removed for histopathological assessment. Results: Both of plasma KIM-1 and TNF-α levels were significantly higher in DM + saline group compared to controls. However, treatment of diabetic rats with adenosine significantly decreased the plasma KIM-1 and TNF-α levels compared to DM + saline group. Significant histopathological changes were observed in diabetic rats whereas adenosine treatment effectively prevented these changes. Conclusions: The findings of the present study suggest that adenosine may be a useful therapeutic agent for preventing DNP.

Effect of tibial tubercle elevation on patellofemoral compressive force in patellofemoral arthrosis.

Abstract In this study, the effect of tibial tubercle elevation on the patellofemoral compressive force (PFCF) was investigated in patients with patellofemoral arthrosis. Fifteen (11 women and 4 men) patients who had undergone tibial tubercle elevation were included in the study. The average follow-up was 4.5 years. The mean age of the patients was 59 years (range 34–71 years). They were able to maintain a normal pain-free daily life. Maximal isometric quadriceps force (Q) was calculated by equating the moment generated by this force to the moment of the force measured at the ankle by a modified hand dynamometer. PFCF was calculated from the quadriceps and patellar tendon forces. Statistical analyses were then applied to the measured and calculated quantities. The mean quadriceps force in the operated knee decreased by 20%. Likewise, the mean PFCF was found to be reduced by 30% in the operated knees as compared with the asymptomatic contralateral knees. The above differences in Q and PFCF between the operated knee and the asymptomatic knee were statistically significant (P < 0.05). Therefore, the results of this study do not agree with the previously held view that Q and PFCF increase due to the removal of pain after the elevation operation. It is our contention that comparison of the forces measured preoperatively in a painful joint with the forces that can be attained postoperatively in the pain-free joint can lead to errors in biomechanical evaluations.

Is it possible to avoid posterior tibial slope increase in open-wedge high tibial osteotomy?:

Aim: Posterior tibial slope has shown to be increased with open-wedge high tibial osteotomy (OWHTO) which may lead to an increase in loading of the anterior cruciate ligament and causing patellofemoral problems in return. In this case series, patients with an OWHTO performed posteromedial to the medial collateral ligament (MCL), keeping it intact was investigated. The aim of this study was to evaluate the influence of this technique on the posterior tibial slope. Methods: Thirty knees (15 right, 15 left) of 28 patients (22 women, 6 men) with a mean age of 53.57±5.9 years who had an OWHTO between January 2014 and February 2016 were included in this study. Surgical technique: A proximal tibial osteotomy is performed posteromedial to MCL keeping it intact. Following the osteotomy, distraction is also performed from the posteromedial aspect of tibia. Fixation is achieved utilizing TomoFix plate. Radiological evaluation: Preoperative and postoperative mechanical axes (MA) were measured on standard weight bearing long axis x-rays. Preoperative and postoperative posterior tibial slope angles were measured on lateral x-rays using three different Methods: the angles between medial tibial plateau and (1) posterior tibial cortex, (2) tibial proximal anatomical axis, and (3) posterior fibular cortex were measured. The correlations of three different measurement methods were analyzed. Patients were grouped according to preoperative MA deviations and postoperative MA changes (either <10º or >=10º). The posterior tibial slope changes were compared between groups. Statistical analyses: All statistical analyses were performed utilizing SPSS 18.0. Results: Mean preoperative and postoperative MA deviations were 9.81°±4.94° and -2.72°± 2.69° respectively. The mean correction angle of MA of lower extremity was 12.62°±4.58°. The three methods used to measure the posterior tibial slope angles were found to be highly correlated with each other ((1) and (2) r=0.961; (1) and (3) 0.906; (2) and (3) 0.934; p values <0.0001). Preoperative mean posterior tibial slope angles were 9.50º±4.47°, 11.51º± 4.50°, and 10.80º±4.58°; postoperative angles were 6.10º±4.23°, 8.78º±4.57° and 8.11º±4.55°, respectively. Posterior tibial slope angle was significantly decreased postoperatively with respect to all three methods (p <0.0001). The changes in the posterior tibial slope was not statistically significant between the groups with preoperative <10º and >=10º deformities (p values 0.861, 0.723, 0.727, respectively). Conclusions: Posterior tibial slope was found to be decreased with this posteromedial OWHTO technique. This technique offered the advantage of preserving the posterior tibial slopes postoperatively even in highly deformed knees which necessitated higher degrees of corrections in the mechanical axes.

Is it possible to use stress radiographs as a tool to diagnose medial meniscus posterior root tears

Aim: Medial meniscus posterior root tear (MMPRT) causes meniscal extrusion, loss of meniscus function, arthritic changes. Clinical history, physical examination and magnetic resonance imaging (MRI) findings are useful for the diagnosis of MMPRT. The aim of this study is to evaluate the utility of stress X-rays in the diagnosis of MMPRT. Methods: Twenty patients who had undergone high tibial osteotomy between March 2015 and May 2016 and whose preoperative bilateral varus and valgus stress x-rays (Telos device) along with weight bearing x-rays were available were included. These patients were grouped into two according to integrity of posterior roots of their medial menisci; there were ten patients both in the study and control groups. Lateral joint space width (LJW) on varus stress x-rays, medial joint space width (MJW) on valgus stress x-rays as well as LJW and MJW on weight bearing x-rays were measured bilaterally. Intragroup comparisons of joint space widths between index and opposite knees were performed. Differences of MJW and LJW between index and opposite knees were calculated. Differences of joint space widths between stress x-rays and weight bearing x-rays were also calculated. The changes in joint space widths between the two groups were compared. Statistical analyses were performed utilizing SPSS 18.0. Significance level was set at 0.05. Results: In MMPRT group, opening of LJ space of index knees under varus stress was greater than that of opposite knees (Index: (mean±SD) 10,27±1,17 mm, opposite: 8,61±1,37 mm; p<0,0001). In the control group the difference was not significant (Index: 9,29±2,55 mm, opposite: 9,68±1,44 mm; p=0,566). The difference in the opening of LJW (under varus stress) between index and opposite knees was significantly greater in the study group (p=0,013). The difference between LJW under weight-bearing and varus stress conditions was significantly greater in the study group. (Study: 3,64±0.217 mm, control:2,28±0,182 mm, p=0.018). Conclusions: The findings of this study showed that in patients who had MMPRTs, an increased opening in the LJW was observed under varus stress conditions. This may be relevant with the fact that when varus stress is applied, meniscal extrusion is increased in case of a MMPRT. Stress x-rays could be a useful tool in the diagnosis of MMPRTs. Further studies are needed to determine the sensitivity and specificity of this diagnostic tool.