ACLD patients exhibit additional knee kinematic asymmetries at the speed level of healthy subjects.

Anterior cruciate ligament deficiency (ACLD) patients tend to walk slowly but try to catch up with the speed level of healthy subjects daily. Exploring the effects of the walking speed level of healthy subjects on the ACLD patients' knee kinematics is important to improving non-operative treatments and delaying the progression of posttraumatic knee osteoarthritis. This study aimed to explore whether healthy controls' walking speed level leads to additional knee kinematic asymmetries in patients with ACLD. 27 ACLD patients and 29 healthy controls were recruited for the study. The ACLD patients walked at two levels of walking speed, including self-selected and healthy controls' walking speed levels. A three-dimensional gait analysis system was used to collect their knee kinematic data. ACLD patients exhibited more kinematic asymmetries when walking at healthy controls' walking speed level than at their self-selected speeds. The kinematic asymmetries included increased posterior tibial translation (4.6 mm) and anteroposterior tibial ROM (3.9 mm), abduction angle (1.5°), and distal tibial translation (3.2 mm) asymmetries (p < 0.05). Our findings are meaningful for developing non-operative treatment strategies for patients with ACLD. To get fewer knee kinematic asymmetries, self-selected walking speed could be suggested for patients with ACLD daily rather than the speed levels of healthy subjects.

The Influence of Age on Sensitivity to Dexmedetomidine Sedation During Spinal Anesthesia in Lower Limb Orthopedic Surgery.

To investigate the influence of age on sensitivity to dexmedetomidine sedation in adult patients, we selected 79 patients scheduled for lower limb orthopedic surgery under spinal anesthesia to identify the dexmedetomidine ED50 for adequate sedation among different age groups. After a spinal anesthetic was placed, a dose of dexmedetomidine determined by the Dixon up-and-down method was administered over 15 minutes. The ED50 in the elderly group was lower than in the other 2 groups (elderly: 0.88 ± 0.07; middle aged: 1.16 ± 0.08; young: 1.21 ± 0.06 µg/kg; both P < .001). There was no difference between the young and middle-aged groups (P = .160).

Biomechanical comparison of single- and double-bundle medial patellofemoral ligament reconstruction.

BACKGROUND: Recurrent patellar dislocation is common clinically, primarily in adolescents. However, the biomechanical properties of single- and double-bundle medial patellofemoral ligament (MPFL) reconstruction remain poorly understood. METHODS: Six fresh frozen adult cadaveric knee specimens were obtained for this study. Each specimen was fixed at 0° to test the force needed when the patella was laterally shifted 10 mm at a speed of 0.5 mm/s, and the test was repeated three times. This test was repeated when knee flexion was at 0°, 15°, 30°, 45°, 60°, and 90°. All six specimens were tested in four statuses, including MPFL intact, MPFL torn, single-bundle MPFL reconstruction, and double-bundle MPFL reconstruction. RESULTS: Similar force is required in these MPFL statuses at 0° of flexion, except for the MPFL torn group with a smaller force (45.5 ± 9.6 N, p < 0.05). The force required in the MPFL torn group reduced from 12.8 to 38.8% compared to other groups, at 0°, 15°, 30°, and 45° of flexion angles. At the flexion of 15°, the double-bundle reconstruction group required a statistically greater force (85.9 ± 10.1 N) compared to the single-bundle reconstruction group (74.0 ± 7.9 N). Interestingly, no statistical difference was found at flexions of 60° and 90° in these four groups. CONCLUSIONS: Both single-bundle and double-bundle MPFL reconstruction can restore the stability of the patella. The double-bundle reconstruction has an angular synergy effect that simulates the MPFL wide footprint in the patella, which enables it to have greater capacity to resist patellar dislocation before the patella entering the femoral trochlea at a smaller flexion angle.

Kinematic characteristics of anterior cruciate ligament deficient knees with concomitant meniscus deficiency during ascending stairs.

It is commonly believed that a torn ACL or a damaged meniscus may be associated with altered knee joint movements. The purpose of this study was to measure the tibiofemoral kinematics of ACL deficiency with concomitant meniscus deficiency. Unilateral knees of 28 ACL deficient participants were studied while ascending stairs. Among these patients, 6 had isolated ACL injuries (group I), 8 had combined ACL and medial meniscus injuries (group II), 8 had combined ACL and lateral meniscus injuries (group III) and 6 had combined ACL and medial-lateral meniscus injuries (group IV). Both knees were then scanned during a stair climb activity using single fluoroscopic image system. Knee kinematics were measured at 0°, 5°, 10°, 15°, 30° and 60° of flexion during ascending stairs. At 0°, 15° and 30° flexion of the knee, the tibia rotated externally by 13.9 ± 6.1°,13.8 ± 9.5° and 15.9 ± 9.8° in Group I. Group II and III exhibited decreased external rotation from 60° to full extension. Statistical differences were found in 0°, 15°and 30° of flexion for the 2 groups compared with Group I. In general, the tibia showed anterior translation with respect to the femur during ascending stairs. It was further determined that Group III had larger anterior translation compared with Group IV at 0° and 5° of flexion (-6.9 ± 1.7 mm vs. 6.2 ± 11.3 mm, P = 0.041; -9.0 ± 1.8 mm vs. 8.1 ± 13.4 mm, P = 0.044). During ascending stairs the ACL deficient knee with different deficiencies in the meniscus will show significantly different kinematics compared with that of uninjured contralateral knee. Considering the varying effect of meniscus injuries on knee joint kinematics, future studies should concentrate on specific treatment of patients with combined ACL and meniscus injuries to protect the joint from abnormal kinematics and subsequent postoperative degeneration.

Anterior Cruciate Ligament Injuries Alter the Kinematics of Knees With or Without Meniscal Deficiency.

BACKGROUND: Numerous studies have investigated kinematic alterations in patients with an isolated anterior cruciate ligament (ACL) injury. However, a substantial proportion of patients with injured ACLs also have concomitant meniscal tears. PURPOSE: To evaluate the in vivo alteration of knee kinematics after an ACL tear, with or without a combined medial or lateral meniscal tear, during level walking activity. STUDY DESIGN: Controlled laboratory study. METHODS: Fifty-six patients with unilateral ACL-deficient (ACLD) knees were studied. Among these patients, 15 had isolated ACL injuries (group 1), 15 had combined ACL and medial meniscal injuries (group 2), 15 had combined ACL and lateral meniscal injuries (group 3), and 11 had combined ACL and medial/lateral meniscal injuries (group 4). The kinematics of each knee was determined using an optical tracking system during treadmill gait. Range of motion (ROM) and kinematic alterations were compared between the contralateral ACL-intact (ACLI) and ACLD knees. RESULTS: All ACLD knees, with or without meniscal deficiency, had significantly less flexion than the ACLI knees (~3°-8°; P < .05). In groups 1, 3, and 4, the injured knees exhibited more femoral external rotation by approximately 1° to 2° (P < .05). Group 4 showed posterior femoral translation (anterior tibial translation) in the swing phase (~13 mm), while groups 2 and 3 showed increased anterior femoral translation (~2-3 mm). During medial-lateral translation, patients in group 2 had a more medial femoral shift (~4 mm) relative to the tibia initially, while those in group 4 exhibited a lateral femoral shift. CONCLUSION: The results indicate that meniscal injuries alter the kinematics of the ACLD knee when compared with knees with an isolated ACL injury. The location of the meniscal tear also affects knee kinematics. CLINICAL RELEVANCE: Considering the varying effects of meniscal injuries on knee joint kinematics, these data provide insight into the pathological function of the ACL-injured knee joint during walking.

Clinical Significance of a Novel Knee Joint Stability Assessment System for Evaluating Anterior Cruciate Ligament Deficient Knees.

OBJECTIVE: To investigate the six degrees of freedom (6DOF) kinematics of anterior cruciate ligament (ACL) deficient knees during gait and to explore the clinical significance of a novel knee joint stability assessment system (Opti_Knee, Innomotion, Shanghai, China) in comparison with imaging and arthroscopic examination. METHODS: Three subjects diagnosed with ACL deficient knees on the basis of preoperative MRI and CT findings were subjected to treadmill gait analysis. Motion of both knees in 6DOF was measured and analyzed with an optical joint kinematics measurement system. Arthroscopic examination, the gold standard, was performed to confirm the final diagnosis and the clinical diagnosis of ACL deficiency by imaging and motion marker techniques compared with this gold standard. RESULTS: Only two of the three subjects diagnosed with ACL deficiency by imaging techniques were later confirmed to have this condition by arthroscopic examination; the third was found to have an intact ACL. When the kinematics of their injured and contralateral knees were compared, abnormalities were found in the two subjects confirmed by arthroscopy to be ACL deficient However, no kinematic difference between the two knees was found in the ACL intact subject. CONCLUSIONS: Opti_Knee (Innomotion) can detect abnormal kinematics in ACL deficient knees and thus provides an effective way of assisting the diagnosis of this condition and has potential for clinical application.

Motion analysis of Chinese normal knees during gait based on a novel portable system.

Normative tibiofemoral data of Chinese or Asian subjects during gait is rarely reported. This study is aimed at investigating the six-degree-of-freedom (6DOF) knee kinematics of adult Chinese during gait, based on a novel portable system. Twenty-eight healthy Chinese subjects (56 knees) were studied during their treadmill gaits. A set of optical marker clusters were attached to the thighs and shanks of each subject, who was tracked by an optical joint kinematics measurement system. Knee landmarks were initially digitized with respect to the marker cluster sets to determine the local coordinate systems for calculation of 6DOF knee joint kinematics. The range of motion (ROM) in 6DOF and 5 kinematic parameters were calculated and compared between bilateral knees and genders. We discovered that knee rotations, as well as motion in proximodistal and mediolateral translations, showed similar patterns in flexion and extension. However, the anteroposterior translations did not show a clear pattern. The results of ROM in 6DOF obtained in this study are comparable with those reported in existing literature. No statistical difference was found between left and right knees either in the ROMs or in the 5 kinematic parameters. However, the ROM in the mediolateral direction during gait was found to be higher in men than women (P=0.014). In addition, the femurs of female subjects rotated more internally than the femurs of male during the stance phase (P=0.011). We concluded that normal Chinese knees exhibited distinct gait patterns, except for anteroposterior motion. Women and men exhibit different axial rotations and mediolateral translation patterns during their treadmill gait.

Biomechanics of single-tunnel double-bundle anterior cruciate ligament reconstruction using fixation with a unique expandable interference screw.

BACKGROUND: Single-tunnel double-bundle (STDB) anterior cruciate ligament (ACL) reconstruction can restore biomechanical function and anatomic structure, but existing methods of graft fixation are not adequate. The aims of this study are to examine knee biomechanics after STDB reconstruction using a unique expandable interference screw for fixation. METHODS: The biomechanical parameters of six pairs of human cadaveric knee specimens were measured with the ACL intact, after ACL removal, and after STDB reconstruction using the interference screw or single-tunnel single-bundle (STSB) reconstruction. Anterior tibial translation under 134 N anterior tibial load in a neutral position as well as in 15° and 30° internal and external knee rotation and the internal tibial rotation angle under the rotatory load (5 N·m internal tibial rotation) were measured. RESULTS: Anterior tibial translations at each degree of knee flexion in the STDB group were significantly less than in the STSB group (all, P<0.05). The internal rotation angles in the STSB group at five flexion angles were significantly higher than in the ACL intact group, whereas there were significantly less than those of the ACL absent group (P<0.05). Under rotatory loads in the neutral position, the tibial internal rotation angles of the STDB group were significantly lower than in the STSB group at all flexion angles (all, P<0.05). CONCLUSIONS: STDB ACL reconstruction with the expandable interference screw provides better anteroposterior and rotational stability than STSB reconstruction. CLINICAL RELEVANCE: The technique provides the advantages of double-bundle reconstruction using a single-tunnel technique.

Arthroscopic reconstruction of shoulder's labrum with extensive tears.

BACKGROUND: With the continuous development of arthroscopic techniques, the majority of superior labrum anterior-posterior (SLAP) lesions can be treated with minimally invasive endoscopic repair. The aim of this study was to determine the efficacy of arthroscopic capsulolabral reconstruction of SLAP lesions with extensive tears. METHODS: Eighteen patients with SLAP lesions with extensive tears (median age, 27.50 years) were included in this study. Twelve patients had type-V SLAP lesions, 4 patients had type-VIII SLAP lesions, and 2 patients had deeply located SLAP lesions. The average duration of follow-up was 15.83 months (range, 11-22 months). Outcome measures included shoulder range of motion (ROM), American Shoulder and Elbow Surgeons (ASES) and Constant-Murley scores, and visual analogue scale (VAS) pain score. RESULTS: After arthroscopic surgery, shoulder forward flexion, shoulder external rotation, and external rotation in 90° of abduction were significantly greater than before surgery (169.5° vs. 165.5°, P = 0.001), (90° vs. 63.5°, P < 0.001), and (90° vs. 81.5°, P = 0.004), respectively. Median ASES and Constant-Murley scores after surgery were both 94 as compared to 77.0 and 77.5, respectively, before surgery (both, P < 0.001). The median VAS score decreased to 1.5 after surgery as compared to 6 before surgery (P < 0.001). CONCLUSIONS: Arthroscopic repair of SLAP lesions with extensive tears can achieve good outcomes.

[Prevention and control strategies of common post-operative complications of microwave ablation in situ in treatment of bone tumors].

OBJECTIVE: To analyze the common post-operative complications of microwave ablation in situ in the treatment of bone tumors and the prevention and control strategies. METHODS: Between March 2009 and July 2012, 73 cases of bone tumors were treated with microwave ablation in situ, of which 54 cases met the inclusion criteria. There were 31 males and 23 females with a median age of 27 years (range, 9-74 years), including 37 malignant tumors and 17 benign tumors. In 49 primary bone tumors, 17 cases were in stage 3, 13 in stage IIA, and 19 in stage IIB according to Enneking grading system. The postoperative complications, managements, and outcomes in patients were analyzed. RESULTS: After operation, 54 patients were followed up 12-40 months (mean, 24 months). Seven kinds of complications occurred in 21 patients (38.9%) with 3 cases suffered from more than one, including pathologic fracture in 4 cases (7.4%), deep infection in 2 cases (3.7%), nerve injury in 7 cases (13.0%), deep vein thrombosis of the lower extremity in 1 case (1.9%), medial collateral ligament heat injury of the knee in 1 case (1.9%), hematoma in 2 cases (3.7%), and fat liquefaction of incision and flap necrosis in 8 cases (14.8%). CONCLUSION: Pathologic fracture is the primary complication which results in a second surgery. Deep infection is the main complication that often leads to failure of the limb salvage. Nerve injury and poor wound healing are the most common complications. Good control of microwave temperature is the key to successful operation, and the related preventive strategies could reduce complications.

[Features of the dual energy technique with dual-source computed tomography for anterior cruciate ligament injuries].

OBJECTIVE: To explore the diagnostic value of the dual-energy technique with dual-source computed tomography (DSCT) for anterior cruciate ligament injuries. METHODS: The clinical data of 8 patients with arthroscopic results were retrospectively reviewed. All patients underwent two- and three-dimensional imaging by multiplanar reconstruction, volume rendering, and tendon mode on DSCT. Dual-energy characteristics were compared with arthroscopic results. RESULTS: Six patients who were arthroscopically diagnosed as anterior cruciate ligament injuries, all of them were also correctly diagnosed by DSCT. Two patients who were arthroscopically diagnosed as normal, one was also diagnosed as normal by DSCT and the other was misdiagnosed. The overall agreement rate was 87.5% (7/8) . Under the dual energy tendon mode, the dual energy staining of the injured anterior cruciate ligament was lower than that of the contralateral normal cruciate ligament of the patient. CONCLUSION: The staining diminution in DSCT imaging may be a new feature that can be used to effectively diagnose anterior cruciate ligament injury.

[Clinical analysis of treating 164 cases of tendon and ligament injuries with allograft tendon].

OBJECTIVE: To research the operative method and the clinical efficacy of repairing and reconstructing tendon and ligament with allograft tendon. METHODS: From September 2000 to May 2007, 164 cases with tendon and ligament injuries were treated, including 116 males and 48 females aged 21-47 years old (average 31.5 years old). There were 126 cases of anterior cruciate ligament injury, 18 cases of complete acromioclavicular dislocation, 10 cases of old dislocation of radial head, 4 cases of Achilles tendon rupture, 2 cases of tibialis anterior muscle rupture, 2 cases of patellar tendon rupture, and 2 cases of rectus femoris rupture. Time interval between injury and hospital admission was 4-345 days (average 75 days). Allograft tendon 10-26 cm in length with suture anchor or absorbable interference screw was used to reconstruct the ligament and tendon. RESULTS: All wounds healed by first intention, except one case of rectus femoris rupture. All patients were followed for 10-36 months (average 21 months). The international knee documentation committee and the Lysholm score of patients with anterior cruciate ligament injury 12 months after operation were significantly higher than that of before operation (P < 0.01). According to the Lazzcano and Karlsson score standard, 13 cases of complete acromioclavicular dislocation at 10-12 months after operation were graded as excellent and 5 cases were good. According to Arner Lindholm score standard, 3 cases of Achilles tendon rupture at 8-16 months after operation were graded as excellent and 1 case was good. For the patients with tibialis anterior muscle rupture, at 10-17 months after operation, the limitation of dorsal extension in ankle joint was 5 degrees, and the muscle strength in the anterior tibialis muscle was decreased. For the patients with patellar tendon rupture, one completely restored the motion range of the knee joint 14 months after operation, the other had knee extension limitation of 10 degrees at 13 months after operation. For the patients with rectus femoris rupture, one had 15 degrees of extension limitation at 18 months after operation, the other suffered limitation of both extension and genuflex at 12 months after operation. According to the Broberg-Morrey score standard, 7 cases with old dislocation of radial head were graded as excellent and 3 cases were good at 3-36 months after operation. CONCLUSION: Allograft tendon is a good material for repairing and reconstructing tendon and ligament injuries, but attention should be paid to postoperatively early exercise under appropriate protection and early management of local rejection.

[Preparation of cisplatin-impregnated coral hydroxyapatite drug delivery system].

OBJECTIVE: To prepare a cisplatin-impregnated coral-derived hydroxyapatite (CCHA) drug delivery system (DDS), and evaluate its inhibitory effect on human osteosarcoma cells U-2 OS, human breast cancer and prostatic carcinoma cells PC-3 in vitro. METHODS: The coral-derived hydroxyapatite (CHA) was manufactured by hydrothermal exchange and impregnated with cisplatin by vacuum freeze-drying techniques. The leaching solutions of this DDS was collected at different intervals in a course of 8 weeks and their inhibitory effect on the cells was tested in vitro by MTT assay. RESULTS: Electron microscope showed that cisplatin was distributed homogeneously in the pores of CHA. The inhibition rates of the leaching solution on all the tumor cells exceeded 50% except for PC-3 cells, whose inhibition rate was 29.92% when treated with the solution collected at the eighth week. CONCLUSION: CCHA allows sustained drug release and maintains excellent inhibitory effect on human bone tumor cells within 8 weeks in vitro.

[Results of 1310 knees of meniscal treatment evaluated by arthroscopy].

OBJECTIVE: To evaluate results of 1310 knees of meniscal treatments by arthroscopy and to present good method of meniscal treatment. METHODS: Their age, traumatic mechanism and effects under arthroscopy were analysed in a series of 254 patients with meniscal injuries, there were 880 males and 374 females, the average of the patients was 25.5 years. The meniscal repair in 68 knee, partial meniscectomy in 756 knee, total meniscectomy in 480 knee and conservative treatment in 6 cases. RESULTS: The patients were followed up 1 to 12 years with the average of 4 years and 3 months. The mean Lysholm score was 86.3 points in arthroscopic meniscal repair, 84.0 points in partial meniscectomy and 76.1 points in total meniscectomy. The mean Lysholm 98.7 points in all children patients with conservative treatment. They showed significant difference (P < 0.01) in the results of three treatments. CONCLUSIONS: Meniscal injuries should not cut off as it, should be repaired in 5 mm from meniscus to synovium and or partial meniscectomy. The general adoption is not the surgical operation on meniscal injuries of the child.

[Biomechanical response of the femur-tibia model under impact loading of the body weight].

OBJECTIVE: To study the biomechanical response and the role of articular surface on the femur-tibia model under impact loading of the body weight. METHODS: A three-dimensional finite element (FE) model of the femur-tibia composite was reconstructed using the image data of the knee joint of Virtual Chinese Human No.1 Male, and FE calculation was performed to simulate the impact of the body weight on the knee joint while walking. RESULTS: The femur-tibia composite was compressed during the impact with obvious protrusive movement. Diffusion and attenuation of the stress occurred during its conduction to the articular surface. CONCLUSION: The femur-tibia composite is unstable under the vertical impact loading of the body weight, with obvious protraction movement, and the articular surface may serve as the buffer of the impact.

[Comparative clinical observation of the short-term bone fusion effect of composite biosynthetic bone and ilium auto-grafting].

OBJECTIVE: To evaluate the short-term bone fusion after implantation of composite biosynthetic bone made of coralline hydroxyapatite composite (CHC) as a substitute for autologous bone grafting. METHODS: A clinical sequential trial was designed and the biosynthetic bone and the patient's ilium were respectively used in the treatment of femoral nonunions and interbody fusion. X-ray examinations were performed 10 weeks after the operations and the bone fusion was graded according to Lane-Sandhu's method. RESULTS: The biosynthetic bone was capable of bone fusion as observed in this experiment. Sequential analysis found that the upper bound was reached when the X-ray examination scores of 15th pairs were transcribed in the chart with 2 pairs of cases dismissed for having the same grade. CONCLUSION: The bone fusion effect of CHC is better than auto-grafting judging from the present observation at 10 weeks after operation.

[The reason and prevention of upper cervical reoperations].

OBJECTIVE: To discuss the reasons for the operation performed on 13 patients with upper cervical disease and to explore the management and prevention of upper cervical disease. METHODS: Thirteen patients with upper cervical disease were retrospectively reviewed. The reason for of reoperations on these patients were analyzed. The measures to reduce upper cervical operational complication and bad prognosis were discussed to avoid reoperations. RESULTS: The reasons for reoperations included 9 cases with unstable or re-dislocated atlantoaxial joint, 10 cases with residual spinal cord compression, 1 case with malposition of odontoid screw, 1 case with adjacent cervical spine regression, 1 case with occipital-cervical fusion failure, 1 case with spinal cord injury during operation, 1 case with bone-plant slipped into canales spinalis, and 1 case with demand to take out internal fixation for aggravated symptom. CONCLUSIONS: The common reasons for upper cervical reoperations were due to instability or redislocation of atlantoaxial joint and residual of spinal cord compression. Some measures such as reducing operate miss, using firm internal fixation and decompressing were advisable to decrease the incidence of reoperations.

[Mosaicplasty osteochondral grafting to repair cartilaginous defects under arthroscopy].

OBJECTIVE: To study mosaicplasty a as method of autogenous osteochondral transplantation in the treatment of cartilaginous defects. METHODS: The technique involves obtaining small cylindrical grafts from the non-weight bearing periphery of the femur at the patellar femoral joint, and transporting them to the prepared recipient site by arthroscopy. RESULTS: Fifteen patients with defects cartilaginous received mosaicptasty osteochondral grafting. Follow up for 12 to 21 months (mean 15 months) showed good results. CONCLUSION: The treatment is indicated for patients with focal cartilaginous defects under the age of 45.