Objective To summarize the occurrence mechanism of backside wear, the method of evaluating backside surface damage, the relationship between backside wear and osteolysis in acetabulum, and the approach to reduce backside wear in total hip arthroplasty with modular acetabulum prosthesis. Methods The recent articles about the backside wear in acetabular liners were extensively reviewed. Results Backside wear in acetabular liners is connected with micromotion between the liner and the shell, rough interface, thickness of the liner, and impingement. The methods to evaluate backside wear damage are only proceeded in revised acetabular liners. Backside wear can generate polyethylene particles that is likely related to the process of osteolysis in acetabulum through the screw holes of metallic shell. To reduce backside wear between the liner and the shell, measures such as improved locking mechanisms, smooth inner metallic shell, maximized shell liner conformity, improving the quality of polyethylene, and reducing impingement can be taken. Conclusion There is no method of evaluating the backside wear in vivo. The relationship between backside wear and osteolysis in acetabulum as well as aseptic loosening of acetabulum prosthesis is controversial.
ObjectiveTo compare the short-term effectiveness of femoral prosthesis with different neck-shaft angles for the reconstruction of proximal femoral anatomy after total hip arthroplasty (THA). MethodsBetween January 2012 and December 2013, 101 patients undergoing unilateral THA who accorded with selection criteria were selected for a retrospective study. The patients were divided into 2 groups:during THA, femoral prosthesis with 135° neck-shaft angle was used in 52 patients (group A) and femoral prosthesis with 127° neck-shaft angle was used in 49 patients (group B). There was no significant difference in gender, age, weight, body masss index, pathogeny, disease duration, preoperative neck-shaft angle, leg discrepancy, and preoperative Harris score between 2 groups (P>0.05). The postoperative Harris score was recorded to evaluate the effectiveness. And the femoral offset of the operated and contralateral sides, the change value of the femoral offset (xFO), the ratio of xFO to the offset of contralateral side (sdFO), the number of patients whose sdFO was more than 15% or less than -15% (outlier), the global offset, the height of femoral head rotation center, and leg discrepancy were measured at postoperation. ResultsOperative incision healed by first intension in 2 groups; no complication of infection, dislocation, or revision was found. All patients were followed up 12-32 months (mean, 23 months). The Harris score at last follow-up were significantly improved when compared with preoperative score in 2 groups (P＜0.05), but there was no signficant difference between 2 groups (t=1.267, P=0.832). The xFO and sdFO of group B were significantly larger than those of group A (P＜0.05); the number of outlier was 20 in group A and was 33 in group B, showing significant difference (P=0.005). The height of femoral head rotating center and global offset at 3 months after operation showed no signficant difference between 2 groups (P>0.05). And significant improvement in leg discrepancy was found at 3 months in 2 groups (P＜0.05), but there was no significant difference between 2 groups (t=0.403, P=0.689). ConclusionBoth of the two femoral prosthesis with different neck-shaft angles can restore the proximal femoral anatomy well and gain similar early effectiveness after THA. However, the Stryker Trident femoral prosthesis with 127° neck-shaft angle may have the tendency to enlarge the femoral offset.
ObjectiveTo explore the effectiveness of simple Ilizarov ring external fixation technique in treatment of tibial plateau fractures complicated with osteofascial compartment syndrome.MethodsBetween September 2013 and March 2017, 30 patients with tibial plateau fractures complicated with osteofascial compartment syndrome were treated with simple Ilizarov ring external fixation technique. There were 23 males and 7 females, with an average age of 34.4 years (range, 23-43 years). The injuries were caused by traffic accident in 12 cases, by falling from height in 4 cases, by falling in 8 cases, and by a crashing object in 6 cases. The time from injury to admission was 1-12 hours (mean, 4.8 hours). According to the Schatzker classification, there was 1 case of type Ⅱ, 3 cases of type Ⅲ, 10 cases of type Ⅳ, 7 cases of type Ⅴ, and 9 cases of type Ⅵ. All patients underwent fasciotomy due to osteofascial compartment syndrome; the interval between fasciotomy and operation was 10-15 days (mean, 12.5 days). Knee Society Score (KSS) and Ilizarov Method Research and Application Association (ASAMI) protocol were used to evaluate knee function.ResultsThe operation time was 110-155 minutes (mean, 123.1 minutes); the intraoperative blood loss was 100-500 mL (mean, 245 mL); the postoperative hospital stay was 3-5 days (mean, 3.8 days). All patients were followed up 20-24 weeks (mean, 22.7 weeks). Except for 2 patients with signs of needle tract infection, no other complication occurred. X-ray films showed that the fractures healed, and the healing time was 10-20 weeks (mean, 14.6 weeks). At last follow-up, the KSS clinical score was 70- 95 with an average of 87.5; the functional score was 70-90 with an average of 79.0. According to ASAMI protocol evaluation, the effectiveness was rated as excellent in 24 cases, good in 3 cases, fair in 2 cases, and poor in 1 case.ConclusionFor tibial plateau fractures complicated with osteofascial compartment syndrome, simple Ilizarov ring external fixation technique can basically restore joint function and has fewer complications. It is a relatively safe and effective treatment method.
ObjectiveThe anatomical calcaneal external fixator was designed by measuring and calculating the morphological data of the heel.MethodsA total of 100 normal people were randomly selected to obtain 200 hind foot data, including 45 males and 55 females, with an average age of 43.9 years (range, 19-67 years). According to the principles of human engineering and local anatomy, the morphological data of the heel in the weight-bearing standing position and supine position were measured with the direct measurement mode. The heel length, heel width, heel height, medial ankle height, lateral ankle height, and calcaneal pitch angle (CPA) were measured by vernier calipers and ulnar markers in weight-bearing standing position, and the gender groups and left and right foot groups were compared; the shape of the hind foot in the supine position was measured by three-dimensional (3D) dot matrix inverse model method. According to the stereoscopic data of the comprehensive anatomical morphology of the heel, the anatomical calcaneal external fixator was designed with AutoCAD 2019 and other 3D industrial design softwares.ResultsThe measurements of shoe size, heel length, heel width, heel height, medial ankle height, lateral ankle height, and CPA in male were significantly higher than those in female (P<0.05). There was no significant difference between the left and right feet in the other indexes except that the height of the medial malleolus of the left foot was significantly lower than that of the right foot (t=−2.827, P=0.005). The measurement of 3D dot matrix inverse model in supine position showed that the heel part was non-circular arc edge, and many groups of arc edges fluctuate in a limited range. Based on the above data, an anatomical calcaneal external fixator was designed, which could fit the anatomic radian in theory, so as to be flexible in configuration. On this basis, the ordinary configuration, compression configuration, and orthodontic configuration were designed to meet the treatment needs of calcaneal fractures in different degrees. The ordinary configuration was suitable for patients with Sanders Ⅰ, ⅡA, and ⅡB calcaneal fractures with no or slight displacement of intra-articular fractures; the ordinary configuration was mainly used for simple fixing. The compression configuration was suitable for patients with Sanders ⅡC, ⅢA, and ⅢB, tongue fractures, and avulsion fractures with severe displacement of intra-articular fractures; the compression configuration used obliquely drawn console wires to fix the displaced bones. The orthodontic configuration was suitable for patients with Sanders ⅢC and Ⅳ calcaneal fractures with severe displacement of intra-articular fractures or severe calcaneal bone defects; the orthodontic configuration was a multi-module design, which took into account the stable fixation of the fracture and the arbitrary adjustment of the joint fixation angle.ConclusionThe hind foot is special for morphology, so the external fixator designed based on the vernier caliper measurement method and 3D dot matrix measuring plate measurement method is an anatomical type and its configuration can theoretically meet stable and flexible clinical needs.
ObjectiveTo investigate the effectiveness of the nose ring drain (NRD) technique combined with Ilizarov circular external fixation in treatment of Gustilo ⅢA Pilon fracture.MethodsBetween March 2017 and December 2019, 17 patients with Gustilo ⅢA Pilon fractures were admitted and treated with NRD technique combined with Ilizarov circular external fixation. Among them, there were 11 males and 6 females; the age ranged from 24 to 63 years, with an average of 38.2 years. There were 3 cases of traffic accident injury, 13 cases of falling injury, and 1 case of penetrating injury. There were 13 cases of emergency admittance and 4 cases of wound infection after surgical treatment. Furthermore, there were 2 cases of fibula fractures and 3 cases of lateral malleolus fractures. ResultsAll patients were followed up 8-12 months, with an average of 9.9 months. All wounds healed by first intention, and 4 patients with preoperative infection had no recurrence during the follow-up. The external fixator was removed after fracture healing in 17 patients at 3-7 months after operation (mean, 4.5 months). At last follow-up, the pain score of the ankle joint Kofoe score was 40-50, with an average of 44; the functional score was 17-27, with an average of 25; the mobility score was 8-18, with an average of 14; and the effectiveness was rated as excellent in 8 cases, good in 7 cases, and poor in 1 case.ConclusionFor Gustilo ⅢA Pilon fractures, the NRD technique combined with Ilizarov circular external fixation has advantages of good fracture fixation and drainage effects, which greatly reduces the complications of traditional treatment options and the number of operations.