Objective To investigate the morphological changes of the proximalfemur and their implication to the total hip arthroplasty in patients with Crowe Ⅱ/Ⅲ developmental dysplasia of the hip (DDH). Methods The experimental gr oup was composed of 15 hips in 14 patients (Crowe Ⅱ, 9 hips; Crowe Ⅲ, 6 hips ) with osteoarthritis secondary to Crowe Ⅱ/Ⅲ DDH (2 males, 12 females; age, 35-61 years). None of the patients had accepted any osteotomy treatment. The control group was composed of 15 normal hips in 15 patients with unilateral DDH (3 males, 12 females; age, 35-57 years). Twelve hips came from the experimental group and the other 3 came from the patients with unilateral Crowe Ⅰ DDH. The femurswere examined with the CT scanning. The following parameters were measured: theheight of the center of the femoral head (HCFH), the isthmus position (IP), theneckshaft angle(NS), the anteversion angle, the canal flare index, and the canal width. Then, the analysis of the data was conducted. Results HCFH and IP in theexperimental group and the control group were 50.1±6.7 mm, 50.1±7.4 mm, and 107.4±21.5 mm, 108.7±18.1 mm，respectively, which had no significant differencebetween the two groups（Pgt;0.05）. In the experimental group and the control group, the NS were 138.3±10.0° and 126.7±5.7°，the anteversion angles were 36.5±15.9° and 18.8±5.4°, and the canal flare indexes were 4.47±0.40and 5.01±0.43. There was a significant difference between the two groups in the above 3 parameters （Plt;0.05）. As for the canal width of the femur, therewasa significant difference in the interior/exterior widths and the anterior/posterior widths at the level of 2 cm above the lesser trochanter and 4 cm belowthe lesser trochanter between the two groups （Plt;0.05）; however, there was nosignificant difference in the canal width of the femur at the isthmus between the two groups（P＞0.05）. Conclusion It is necessary to evaluate the morphology of the proximal femur before the total hip arthroplasty performed in patients with Crowe Ⅱ/Ⅲ DDH. The straight and smaller femoral prosthesis should be chosen and implanted in the proper anteversion position duringoperation.
Objective To compare the biomechanical characteristics of the less invasive stabilization system (LISS) and the dynamic condylar screw (DCS) in the fixation of subtrochanteric fractures of the femur so as to provide theoretical basis for choosing internal fixator in clinical application. Methods Twelve cadaveric human femurs (35-50 years old) were selected with similar proximal femur, excluding deformities, fractures, and other lesions. The twelve femur specimens were randomly divided into 2 groups, 6 specimens per group. An 1 cm gap of osteotomy model was made in the proximal femur up to 1 cm below the lesser trochanter to simulate a comminuted subtrochanteric fracture of femur, and the distal end was embedded with denture acrylic and liquid for denture acrylic. Fracture was fixed by LISS in group A, and was fixed by DCS in group B. The specimens were fixed on Instron-8874 servo-hydraulic mechanical testing machine in a single-leg standing position, and the axial compression test and dynamic fatigue test were carried out to compare the compressive strength and the strain distribution at both sides of the fracture line. Results Axial compression test: the strain values of the 2 strain gauges in group A were significantly smaller than those in group B (P lt; 0.01); the vertical down displacement of the femoral head in group A was significantly smaller than that in group B (P lt; 0.01) under the same load; when the load was 600 N, the axial rigidity of group A was (209.06 ± 18.63) N/mm, which was significantly higher than that of group B [(65.79 ± 7.26) N/mm] (t=3.787, P=0.004). Dynamic fatigue test: the vertical down displacement of the femoral head in group A was significantly smaller than that in group B in the same cyclic loading cycle (P lt; 0.01); when the vertical down displacement of the femoral head was 0.5 mm, the force and the cyclic loading cycles in group A were significantly larger than those in group B (P lt; 0.01). Conclusion LISS, which has good mechanical stability, can meet the requirements for subtrochanteric fracture of femur fixation in biomechanics and anatomical structures. It can be proven that the LISS internal fixator is firmer than the DCS internal fixator by biomechanical comparison.
Objective To study the effectiveness of anterolateral C-shaped approach in the treatment of intertrochanteric fracture of the femur in elderly patient by comparing with traditional anterolateral approach. Methods Between April 2010 and November 2011, 66 patients with intertrochanteric fracture of the femur were analyzed retrospectively. Of 66 patients, 37 underwent improved anterolateral C-shaped approach combined with fixation of dynamic hip screw (DHS) (improved group), and 29 underwent traditional anterolateral approach combined with fixation of DHS (conventional group). There was no significant difference in gender, age, injury cause, side, disease duration, fracture type, and complication between 2 groups (P gt; 0.05). The operation time, intraoperative blood loss, postoperative drainage volume, and hospitalization time were recorded; and X-ray films were taken to observe the fracture healing. The hip function was evaluated according to self-established criterion. Results The operation was successfully completed in all patients, and primary healing of incision was achieved. All patients were followed up 12-24 months (mean, 17.8 months). Bone union was achieved in both groups; the fracture healing time was 3-6 months (mean, 4.8 months). No loosening or breaking of internal fixation was observed during follow-up period. The operation time and postoperative drainage volume of improved group were significantly less than those of conventional group (P lt; 0.05); no significant difference was found in intraoperative blood loss and hospitalization days between 2 groups (P gt; 0.05). According to self-established criterion, improved group was significantly better than conventional group in recovery of hip joint motion and function at 6 and 12 months after operation (P lt; 0.05). Conclusion Anterolateral C-shaped approach combined with DHS could minimize muscle injury and scar formation, which is beneficial to surgical exposure and early postoperative rehabilitation.
Objective To investigate the effect of the morphological changes in the proximal femur on the prothesis selection in the total hip arthroplasty in the patients with ankylosing spondylitis. Methods The experimental group was composed of 13 patients (16 hips) with ankylosing spondylitis, which was treated with the total hip arthroplasty, and the control group was composed of 16 patients（19 hips）with non-ankylosing spondylitis，which was also treated with the total hip arthroplasty. In the two groups, the measurements of Singh index，canal flare index，morphological index of the cortex and cortical index were performed in the two groups. Results The results of the statistical analysis on Singh index，canal flare index, morphological index of the cortex and cortical index in the experimental group were 3.81±0.54, 2.63±0.41, 2.02±0.38 and 1.69±0.69, respectively, but 4.63±0.62, 3.03±0.27, 2.76±0.28 and 2.12±0.24, respectively in the control group. Therewas a significant difference in Singh index, canal flare index, and morphological index of the cortex between the two groups (Plt;0.05)，while there was no statistical difference in cortical index between the two groups (P＞0.05). The patientswith ankylosing spondylitis had more serious osteoporosis in their proximal femur. Conclusion Cemented femoral prosthesis should be used in the total hip replacement in patients with ankylosing spondylitis, and the revision total hip arthroplasty should be performed on patients with more serious osteoporosis.
Astronauts who are exposed to weightless environment in long-term spaceflight might encounter bone density and mass loss for the mechanical stimulus is smaller than normal value. This study built a three dimensional model of human femur to simulate the remodeling process of human femur during bed rest experiment based on finite element analysis (FEA). The remodeling parameters of this finite element model was validated after comparing experimental and numerical results. Then, the remodeling process of human femur in weightless environment was simulated, and the remodeling function of time was derived. The loading magnitude and loading cycle on human femur during weightless environment were increased to simulate the exercise against bone loss. Simulation results showed that increasing loading magnitude is more effective in diminishing bone loss than increasing loading cycles, which demonstrated that exercise of certain intensity could help resist bone loss during long-term spaceflight. At the end, this study simulated the bone recovery process after spaceflight. It was found that the bone absorption rate is larger than bone formation rate. We advise that astronauts should take exercise during spaceflight to resist bone loss.
Objective To evaluate the effectiveness of membrane induction technique in the treatment of Gustilo-Anderson ⅢB type injury of distal femur complicated with bone defect. Methods The clinical data of 20 patients with Gustilo-Anderson ⅢB type injury of distal femur complicated with bone defects admitted between January 2019 and December 2020 were retrospectively analyzed, including 15 males and 5 females, with an average age of 35 years (range, 19-70 years). Causes of injuries included 15 cases of traffic accidents and 5 cases of falling from height. Bone defect located at metaphyseal in 11 cases and at proximal metaphyseal in 9 cases. The time from injury to primary first-stage surgery was 4-28 hours, with an average of 11 hours. After primary radical debridement, the length of bone defect was 3-12 cm, with an average of 6 cm. Antibiotic-containing bone cement was implanted in the bone defect site to induce membrane formation. At 34-56 days (mean, 45 days) after the first-stage surgery, bone grafting was performed in the induced membrane for the repair and reconstruction of bone defects; 16 patients received a combination of autogenous cancellous and allogeneic bone grafts and 4 patients received cancellous bone grafts. The bone graft healing time after the second-stage surgery was recorded; the visual analogue scale (VAS) score and Lysholm score were compared before the second-stage bone graft and at last follow-up to evaluate the pain and functional improvement of the affected limb; and the knee joint range of motion at last follow-up was recorded. Results None of the patients had a second revision after the first-stage surgery, 1 patient recieved flap transfer and the flap survived well after operation. All patients were followed up 12-36 months after the second-stage surgery, with an average of 23 months. All patients achieved bone union, and the bone union time was 7-10 months (mean, 8.4 months). No bone nonunion or donor site related complications occurred. The Lysholm score and VAS score at last follow-up were 85.6±4.1 and 1.7±0.8, respectively, and they were significantly improved when compared with those before the second-stage bone defect repair (42.7±4.6 and 7.1±0.8, respectively) (t=37.410, P<0.001; t=21.962, P<0.001). Knee flexion range of motion was 60°-120°, with an average of 95°; the limit of elongation was 0°-10°, with an average of 5°. ConclusionFor Gustilo-Anderson ⅢB type injury of distal femur complicated with bone defect, induction membrane technique can effectively control infection, promote bone healing of the defect site, and effectively restore the function of lower limbs with satisfactory effectiveness.
Objective To assess the effectiveness of the new anterolateral approach of the distal femur for the treatment of distal femoral fractures. Methods Between July 2007 and December 2009, 58 patients with distal femoral fractures were treated by new anterolateral approach of the distal femur in 28 patients (new approach group) and by conventional approach in 30 patients (conventional approach group). There was no significant difference in gender, age, cause of injury, affected side, type of fracture, disease duration, complication, or preoperative intervention (P gt; 0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, hospitalization days, and Hospital for Special Surgery (HSS) score of knee were recorded. Results Operation was successfully completed in all patients of 2 groups, and healing of incision by first intention was obtained; no vascular and nerves injuries occurred. The operation time and intraoperative fluoroscopy frequency of new approach group were significantly less than those of conventional approach group (P lt; 0.05). But the intraoperative blood loss and the hospitalization days showed no significant difference between 2 groups (P gt; 0.05). All patients were followed up 12-36 months (mean, 19.8 months). Bone union was shown on X-ray films; the fracture healing time was (12.62 ± 2.34) weeks in the new approach group and was (13.78 ± 1.94) weeks in the conventional approach group, showing no significant difference (t=2.78, P=0.10). The knee HSS score at last follow-up was 94.4 ± 4.2 in the new approach group, and was 89.2 ± 6.0 in the conventional approach group, showing significant difference between 2 groups (t=3.85, P=0.00). Conclusion New anterolateral approach of the distal femur for distal femoral fractures has the advantages of exposure plenitude, minimal tissue trauma, and early function rehabilitation training so as to enhance the function recovery of knee joint.
To evaluate the efficacy and safety of comprehensive prophylaxis for deep venous thrombosis(DVT) after proximal femur fractures in geriatric patients. Methods From July 2003 to May 2006, 157 geriatric patients with proximal femur fractures treated with operation were divided into prophylaxis group and control group randomly. There were 82 patients (34 males, 48 females, aged 65-97 years) in prophylaxis group, 30 with femoral neck fracture and 52 with intertrochanteric fracture of femur. There were 75 patients (33 males, 42 females, aged 65-94 years) in control group, 28 with femoral neck fracture and 47 with intertrochanteric fracture of femur. In the prophylaxis group, comprehensive prophylaxis for DVT which included Aspirin, fibrinolytic enzyme, passive and active circumduction of the foot and ankle, CPM management wasappl ied. In the control group, no thromboproxylaxis was taken. All patients in the both groups received color doppler flow imaging (CDFI) examination before operation and on the 7th and 14th days after operation. Results CDFI found 2 cases of DVT in the prophylaxis group 7 and 14 days after operation respectively, while 21 and 15 cases of DVT in the control group respectively. The incidence of DVT was 48.0% in the control group compared with 4.9% in the prophylaxis group and the reduction was significant (P lt; 0.01). One patient gave up the intervention due to Melena 3 days after operation in the prophylaxis group. In the control group, 1 patient died 8 days after operation and another died 11 days after operation. Both died of acute pulmonary embol ism confirmed by autopsy. Conclusion The comprehensive prophylaxis can significantly decrease the incidence of DVT in geriatric patients after proximal femur fractures. There is no significant adverse effect during the intervention.
Objective To study the clinical outcome of comminuted factures at distal femur and proximal tibia treated with AO less invasive stabilization systems (LISS). Methods The clinical data of 14 cases of distal femoral fracture and proximal tibial fracture from September 2003 to May 2005 were analyzed retrospectively. The injury was caused by traffic accident in 9 cases, by fall in 3 cases and by slipping in 2 cases. Of 14 cases, there were 5 open fractures and 9 close fractures, including 5 cases of distal femoral comminuted fracture and 9 cases of proximal shaft comminuted fractures. According to AO/OTA classification, the fractures were classified as 33C2 in 3 cases，33C3 in 2 cases,41A2 in 2 cases，41A3 in 2 cases，41B2 in 3 cases and 41C2 in 2 cases. All patients were treated by the internal fixation with LISS-distal femur or with LISS-proximal tibia. Healing of wounds, the X-ray films before and after operations, and therecovery of joint function were observed. Results The patients were followed up from 1 month to 20 months (11 months on average). Twelve cases achieved solid osseous unions from 3 months to 5 months postoperativly; 2 cases had a good reduction and recovered smoothly 2-3 months postoperatively. The results were excellent in 10 cases, good in 3 cases and fair in 1 case according to Johner-Wruhs knee scoring. The range of knee flexion-extension was 110-130° in 11 cases, 100° in 2 cases and 80° in 1 case. Conclusion LISS is an effective method of internal fixation for treating comminntedfracture of distal femur or proximal tibia. It has the advantages of less injury, satisfied reduction and reliable fixation.
ObjectiveTo study the effectiveness of a new anterolateral approach of distal femur in the treatment of type C distal femoral fractures by comparing with traditional lateral and anterolateral approaches. MethodsThe clinical data of 51 patients with type C distal femoral fractures treated between January 2008 and August 2011 were retrospectively analyzed. Of 51 patients, 24 patients received the new anterolateral approach of distal femur combined with fixation of condylar buttress plate (modified group), and 27 patients underwent traditional lateral or anterolateral approach combined with fixation of condylar buttress plate (traditional group). There was no significant difference in gender, age, injury cause, American Society of Anesthesiologist (ASA) classification, side, fracture type, complication, and the time from injury to operation between 2 groups (P>0.05). The operation time, intraoperative blood loss, frequency of intraoperative fluoroscopy, hospitalization time, fracture healing time, and Hospital for Special Surgery (HSS) scores of the knee at 3, 6, and 12 months were recorded. ResultsThe operation was successfully completed and the incision healed by first intention in all patients. The operation time and frequency of intraoperative fluoroscopy of modified group were significantly less than those of traditional group (P<0.05). But the intraoperative blood loss and the hospitalization time showed no significant difference between 2 groups (P>0.05). All patients were followed up 12-37 months (mean, 21.3 months). X-ray films showed all fractures were union. The fracture healing time was (12.92±2.24) weeks in the modified group and (13.24±2.52) weeks in the traditional group, showing no significant difference (t=0.476, P=0.637). The knee HSS scores of modified group were significantly higher than those of traditional group at 3, 6, and 12 months after operation (P<0.05). There was no significant difference in the incidence of knee varus or valgus, leg length discrepancy, internal fixator loosening, flexing dysfunction of knee, traumatic arthritis of knee, and total complications between 2 groups (P>0.05). ConclusionComparing with traditional lateral and anterolateral approaches, using the new anterolateral approach to treat type C distal femoral fractures has the advantages of less damage to soft tissue, excellent exposure, less operation time, and frequency of intraoperative fluoroscopy, and better postoperative rehabilitation of knee joint.