A novel structural dynamics test method and device were designed to test the biomechanical effects of dynamic axial loading on knee cartilage and meniscus. Firstly, the maximum acceleration signal-to-noise ratio of the experimental device was calculated by applying axial dynamic load to the experimental device under unloaded condition with different force hammers. Then the experimental samples were divided into non-specimen group (no specimen loaded), sham specimen group (loaded with polypropylene samples) and bovine knee joint specimen group (loaded with bovine knee joint samples) for testing. The test results show that the experimental device and method can provide stable axial dynamic load, and the experimental results have good repeatability. The final results confirm that the dynamic characteristics of experimental samples can be distinguished effectively by this device. The experimental method proposed in this study provides a new way to further study the biomechanical mechanism of knee joint structural response under axial dynamic load.
Animals ; Cattle ; Biomechanical Phenomena ; Knee Joint/physiology* ; Meniscus ; Mechanical Phenomena ; Weight-Bearing

OBJECTIVE: To investigate the effectiveness of osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation in the treatment of tibial plateau fractures involving posterolateral column collapse. METHODS: A clinical data of 23 patients with tibial plateau fractures involving posterolateral column collapse, who had undergone osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation between January 2015 and June 2021, was retrospectively analyzed. There were 14 males and 9 females with an average age of 42.6 years ranging from 26 to 62 years. The causes of injury included traffic accident in 16 cases, falling from height in 5 cases, and other injuries in 2 cases. According to Schatzker classification, there were 15 cases of type Ⅴ and 8 cases of type Ⅵ. The time from injury to operation was 4-8 days with an average of 5.9 days. The operation time, intraoperative blood loss, fracture healing time, and complications were recorded. The depth of articular surface collapse of posterolateral column and posterior inclination angle (PSA) of the tibial plateau were compared before operation and at 2 days and 6 months after operation; fracture reduction of tibial plateau fracture was evaluated by Rasmussen anatomic score. The recovery of knee function was evaluated by Hospital for Special Surgery (HSS) score at 2 days and 6 months after operation. RESULTS: All 23 patients were completed the operation successfully. The operation time was 120-195 minutes, with an average of 152.8 minutes; the intraoperative blood loss was 50-175 mL, with an average of 109.5 mL. All patients were followed up 12-24 months, with an average of 16.7 months. One patient had superficial wound infection after operation, and the incision healed after dressing change; primary healing of incision of other patients was obtained. The fracture healing time was 12-18 weeks, with an average of 13.7 weeks. No failure of internal fixation, varus and valgus deformity of the knee joint, and instability of the knee joint was found at last follow-up. One patient developed joint stiffness and the range of motion of the knee joint was 10°-100°; the range of motion of the knee joint of other patients was 0°-125°. At 2 days and 6 months after operation, the depth of articular surface collapse of posterolateral column, PSA, and Rasmussen anatomic scores significantly improved when compared with those before operation ( P<0.05). There was no significant difference between the two postoperative time points ( P>0.05). The HSS score at 6 months after operation was significantly higher than that at 2 days after operation ( P<0.05). CONCLUSION For tibial plateau fractures involving posterolateral column collapse, reduction and internal fixation through osteotomy of non-core weight-bearing area of the lateral tibial plateau has the advantages of fully expose the posterolateral column fragment, good articular surface reduction, sufficient bone grafting, and fewer postoperative complications. It is beneficial to restore knee joint function and can be widely used in clinic.
Male ; Female ; Humans ; Adult ; Retrospective Studies ; Blood Loss, Surgical ; Tibial Plateau Fractures ; Treatment Outcome ; Bone Plates ; Tibial Fractures/surgery* ; Knee Joint ; Fracture Fixation, Internal ; Osteotomy ; Weight-Bearing

OBJECTIVE: To study and analyze the clinical effect of the self-developed new adjustable weight-bearing rehabilitation brace in the rehabilitation of the femoral intertrochanteric fracture after the operation of PFNA. METHODS: From July 2015 to June 2017, 62 patients with typeⅡ (Evans-Jensen classification) intertrochanteric fracture of femur were treated with PFNA internal fixation. There were 11 males and 19 females in the routine rehabilitation group, with an average age of (70.73± 6.09) years;17 males and 15 females in the brace rehabilitation group, with an average age of (71.25±6.60) years. Among them, the patients in the routine rehabilitation group recovered according to the routine method, and the patients in the support rehabilitation group used the self-developed new adjustable weight-bearing rehabilitation support of lower limbs to assist the early rehabilitation. The pain intensity(VAS score), weight-bearing of affected limb, clinical healing time of fracture, Harris score and complications were recorded and analyzed. RESULTS: Nine patients lost their visit half a year later, the other 53 patients were followed up for 9 to 18 months. The VAS score at 1, 3, 6 months after operation of brace rehabilitation group was lower than that of routine rehabilitation group(<0.05). The weight bearing of the limbs in the rehabilitation group was significantly higher than that in the conventional rehabilitation group(<0.05), but the clinical healing time of fracture in the brace rehabilitation group was shorter than that in the routine rehabilitation group(<0.05). In addition, the Harris score of the postoperativebrace rehabilitation group was better than that of the conventional rehabilitation group(<0.05). The incidence of complications was lower than that of the conventional rehabilitation group(=0.048). CONCLUSION In the rehabilitation of Evans Jensen typeⅡintertrochanteric fracture after PFNA internal fixation, the new self-developed adjustable weight-bearing rehabilitation brace can significantly relieve postoperative pain, regulate and moderately increase the stress stimulation at the fracture end, so as to promote fracture healing, accelerate the recovery of hip joint function, reduce the incidence of complications, and its clinical effect is safe and reliable.
Aged ; Bone Nails ; Braces ; Female ; Fracture Fixation, Intramedullary ; Hip Fractures ; Humans ; Lower Extremity ; Male ; Middle Aged ; Retrospective Studies ; Treatment Outcome ; Weight-Bearing

OBJECTIVE: To investigate clinical effect of partly weight-bearing walking and functional exercise immediatly after operation for Achilles tendon rupture(ATR) on function of ankle joint and rate of fragmentation of Achilles tendon, through comparing effect of partly weight-bearing walking and functional exercise immediatly at 2 weeks after operation for Achilles tendon rupture. METHODS: Sixty-four patients with ATR selected from March 2012 to March 2013 were randomly divided into two groups. There were 34 patients in treatment group, including 18 males and 16 females with an average age of 41.4±7.6, they began to do functional exercise and walk on fields with partly weight-bearing at two days after operation; there were 30 patients in control group, including 16 males and 14 females with an average age of 39.9±7.6, and they were immobilized with plaster in plantar flexion at two weeks after operation, and started to do functional exercise and walk on fields with partly weight-bearing at two weeks after operation. Two groups were performed by the same doctor with the same operation. The rate of fragmentation of Achilles tendon, and AOFAS score and complications between two groups were observed and compared. RESULTS: AOFAS score in treatment group at two weeks after operation was 74.3±3.9, which in control group was 71.7±4.2, and had statistical differences between two groups; AOFAS score in treatment group at one year after operation was 93.3±3.9, which in control group was 92.0±4.1, and had no statistical significance. No Achilles tendon fragmentation in treatment group occurred at three years after operation, and 1 patient occurred in control group. Two patients in treatment group occurred complications after operation, and 1 patient occurred in control group, however, there was no statistical significance between two groups. CONCLUSIONS Functional exercise immediate after operation for Achilles tendon rupture(ATR) patients in the early days, the AOFAS scores is higher than the fixing for two weeks, and does not increase the rate of fragmentation of Achilles tendon and complication after operation, and benefits for function recovery.
Achilles Tendon ; Adult ; Female ; Humans ; Male ; Middle Aged ; Rupture ; Tendon Injuries ; Treatment Outcome ; Weight-Bearing

In order to study the mechanical behavior of degeneration and nucleotomy of lumbar intervertebral disc, compression experiments with porcine lumbar intervertebral discs were carried out. The lumbar intervertebral discs with trypsin-treated and nucleus nucleotomy served as the experimental group and the normal discs as the control group. Considering the effects of load magnitude and loading rate, the relationship between stress and strain, instantaneous elastic modulus and creep property of intervertebral disc were obtained. The creep constitutive model was established. The results show that the strain and creep strain of the experimental group increase significantly with the increase of compression load and loading rate, whereas the instantaneous elastic modulus decreases obviously, compared with the control group. It indicates that the effect of load magnitude and loading rate on load-bearing capacity of intervertebral disc after nucleotomy is larger obviously than that of normal disc. The creep behavior of the experimental group can be still predicted by the Kelvin three-parameter solid model. The results will provide theoretical foundation for clinical treatment and postoperative rehabilitation of intervertebral disc disease.
Animals ; Biomechanical Phenomena ; Intervertebral Disc ; physiology ; surgery ; Lumbar Vertebrae ; Stress, Mechanical ; Swine ; Weight-Bearing

PURPOSE: This study examined the effects of self-volar gliding combined with a strap and wrist distraction on pain and the active and passive wrist extension range of motion (ROM) in subjects with dorsal wrist pain during partial weight bearing of the hand.METHODS: Thirty subjects (14 males and 16 females) with dorsal wrist pain during partial weight bearing through the hand participated in this study. The two different self-volar gliding techniques were performed for each group. Self-volar gliding using a strap (SVGS) and SVGS and wrist distraction (SVGSD) were performed five times for one week for each group. The active and passive ROM of wrist extension and the peak pressure pushed by the hand at pain (PPHP) were measured. An independent t-test was used to compare the improvements of these elements between the two different self-volar gliding techniques. The level of statistical significance was at α=0.05.RESULTS: The active and passive ROM of wrist extension and PPHP were greater in both self-volar gliding groups after the one week intervention. On the other hand, these parameters were greater in the SVGSD group than in the SVGS group (p<0.05)CONCLUSION: SVGSD is recommended to improve the active and passive ROM of wrist extension and PPHP in subjects with dorsal wrist pain during partial weight bearing of the hand.
Hand ; Humans ; Male ; Range of Motion, Articular ; Weight-Bearing ; Wrist

PURPOSE: Bone single-photon emission computed tomography/computed tomography (SPECT/CT) has been widely used for evaluation of femoral head viability in patients with femoral neck fracture. The current study aimed to investigate utility of standardized uptake value (SUV) from quantitative bone SPECT/CT for assessment of femoral head viability.METHODS: From March 2015 to November 2018, quantitative bone SPECT/CT was performed in 9 patients with non-viable femoral head post femoral neck fracture and in 31 controls. Maximum (SUV(max)), mean (SUVmean), and minimum standardized uptake values (SUVmin) were measured over femoral head and neck. Mann-Whitney U test with Bonferroni correction was used to compare SUVs of ipsilateral and contralateral femurs from femoral neck fracture patients with those of control femurs.RESULTS: As for femoral head viability, SUV(max) and SUVmean were not significantly decreased in non-viable femoral heads compared to those in controls. Only the SUVmin was significantly reduced in non-viable femoral heads (mean ± standard deviation, 0.57 ± 0.38) than in controls (0.95 ± 0.26, p = 0.006) and contralateral femoral heads (1.36 ± 0.59, p = 0.008). The cutoff SUVmin of 0.61 (g/mL) yielded a sensitivity of 77.8% and specificity of 87.1% for detection of non-viable femoral heads (p = 0.006). Contralateral femoral necks of the femoral neck fracture patients showed significantly higher SUVmean and SUVmin (3.17 ± 1.20 and 1.64 ± 0.63) than those of controls (2.32 ± 0.53 and 1.04 ± 0.27; p = 0.021 and p = 0.002, respectively), which seemed to reflect weight bearing effect or metabolic derangement.CONCLUSIONS: The non-viable femoral heads from the femoral neck fracture showed significantly reduced SUVmin. Quantitative bone SPECT/CT holds promise for objective evaluation of femoral head viability.
Femoral Neck Fractures ; Femur ; Femur Neck ; Head ; Humans ; Neck ; Sensitivity and Specificity ; Weight-Bearing

OBJECTIVE: Corpectomy of the first lumbar vertebra (L1) for the management of different L1 pathologies can be performed using either an anterior or posterior approach. The aim of this study was to evaluate the usefulness of a retroperitoneal extrapleural approach through the twelfth rib for performing L1 corpectomy.METHODS: Thirty consecutive patients underwent L1 corpectomy between 2010 and 2016. The retroperitoneal extrapleural approach through the 12th rib was used in all cases to perform single-stage anterior L1 corpectomy, reconstruction and anterior instrumentation, except for in two recurrent cases in which posterior fixation was added. Visual analogue scale (VAS) was used for pain intensity measurement and ASIA impairment scale for neurological assessment. The mean follow-up period was 14.5 months.RESULTS: The sample included 18 males and 12 females, and the mean age was 40.3 years. Twenty patients (67%) had sensory or motor deficits before the surgery. The pathologies encountered included traumatic fracture in 12 cases, osteoporotic fracture in four cases, tumor in eight cases and spinal infection in the remaining six cases. The surgeries were performed from the left side, except in two cases. There was significant improvement of back pain and radicular pain as recorded by VAS. One patient exhibited postoperative neurological deterioration due to bone graft dislodgement. All patients with deficits at least partially improved after the surgery. During the follow-up, no hardware failures or losses of correction were detected.CONCLUSION: The retroperitoneal extrapleural approach through the 12th rib is a feasible approach for L1 corpectomy that can combine adequate decompression of the dural sac with effective biomechanical restoration of the compromised anterior load-bearing column. It is associated with less pulmonary complication, no need for chest tube, no abdominal distention and rapid recovery compared with other approaches.
Asia ; Back Pain ; Chest Tubes ; Decompression ; Female ; Follow-Up Studies ; Humans ; Lumbar Vertebrae ; Male ; Osteoporotic Fractures ; Pathology ; Ribs ; Spinal Fusion ; Spine ; Transplants ; Weight-Bearing

Animal models of osteoarthritis (OA) have played a key role in understanding the etiology of OA and in the development of new therapeutic strategies. Although pigs have an advantage as an animal disease model due to their similarity to humans, there are few studies on the induction of OA in minipigs. Therefore, this study aimed to characterize disease progression of OA in total medial meniscectomy (TMM)-operated skeletally mature minipigs, up to day 180 postoperatively. There were no significant alterations in vital signs or hematological indices throughout the observation period. However, clinical manifestations of OA in the medial femoral condyles of TMM-operated minipigs were progressive, depending on postoperative duration, with respect to osteophytes formation and roughened surfaces on radiological observation, cartilage erosion under macroscopic examination, and severe cartilage defects including fibrillation, vertical fissures, and cartilage denuding on histopathological observation, with the highest score indicating late-stage OA on day 180 and without indicating apparent variation between subjects. In particular, the lateral femoral condyles were also degenerated, possibly due to localization of weight-bearing from both menisci to the lateral meniscus. Therefore, TMM in minipigs is suitable for reproducible induction of degenerative changes in the femorotibial joints that closely resemble late-stage OA, and is suitable for use in further research.
Cartilage ; Disease Models, Animal ; Disease Progression ; Humans ; Joints ; Menisci, Tibial ; Models, Animal ; Osteoarthritis ; Osteophyte ; Swine ; Swine, Miniature ; Vital Signs ; Weight-Bearing

OBJECTIVES: To evaluate the influence of the restorative technique on the mechanical response of endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. MATERIALS AND METHODS: Forty-eight premolars received MOD preparation (4 groups, n = 12) with different restorative techniques: glass ionomer cement + composite resin (the GIC group), a metallic post + composite resin (the MP group), a fiberglass post + composite resin (the FGP group), or no endodontic treatment + restoration with composite resin (the CR group). Cusp strain and load-bearing capacity were evaluated. One-way analysis of variance and the Tukey test were used with α = 5%. Finite element analysis (FEA) was used to calculate displacement and tensile stress for the teeth and restorations. RESULTS: MP showed the highest cusp (p = 0.027) deflection (24.28 ± 5.09 µm/µm), followed by FGP (20.61 ± 5.05 µm/µm), CR (17.72 ± 6.32 µm/µm), and GIC (17.62 ± 7.00 µm/µm). For load-bearing, CR (38.89 ± 3.24 N) showed the highest, followed by GIC (37.51 ± 6.69 N), FGP (29.80 ± 10.03 N), and MP (18.41 ± 4.15 N) (p = 0.001) value. FEA showed similar behavior in the restorations in all groups, while MP showed the highest stress concentration in the tooth and post. CONCLUSIONS: There is no mechanical advantage in using intraradicular posts for endodontically-treated premolars requiring MOD restoration. Filling the pulp chamber with GIC and restoring the tooth with only CR showed the most promising results for cusp deflection, failure load, and stress distribution.
Bicuspid ; Dental Pulp Cavity ; Endodontics ; Finite Element Analysis ; Glass Ionomer Cements ; Tooth ; Weight-Bearing