Introduction. The anatomic abnormalities are observed in developmental dysplasia of the hip (DDH) and it is challenging to perform the total hip arthroplasty (THA) for some DDH patients. If acetabular cup was placed at the original acetabular position in patients with high hip dislocation, it may be difficult to perform reduction of hip prosthesis because of soft tissue contracture. The procedures resolving this problem were to use femoral shortening osteotomy, or to place the acetabular cup at a higher cup position than the original hip center. Femoral shortening osteotomy has some concerns about its complicated procedure, time consuming, and risk of non-union. Conversely, implantation of the acetabular cup at the higher cup position may eliminate these shortcomings and this procedure is considered to be preferred if possible. However, the criteria of cases without femoral shortening osteotomy are not clear. In this study, we retrospectively analysed the clinical outcomes of patients performed THAs for high hip dislocation, and clarified the adaptation of THA with or without femoral shortening osteotomy. Methods. We included a total of 65 hip joints from 57 patients who underwent primary THA using Modulus stem for high hip dislocation from November 2007 to December 2015 at our institution. The mean follow up period was 5.2 years (2 – 10 years). The mean age at surgery was 65.4 years (Table 1). Thirty seven hips were classified as Crowe III, and twenty eight hips as Crowe IV based on Crowe classification. We classified patients into two groups based on the use of femoral osteotomy. Then, we compared the surgical time, blood loss, Japanese Orthopaedic Association (JOA) Score as clinical outcomes, preoperative position of the greater trochanter, the cup position, and complications between two groups. The position of the greater trochanter was measured the height of the tip of greater trochanter from the inter teardrop line. The cup center position was assessed by measuring the distance between the cup center and ipsilateral tear drop. Receiver operating characteristic (ROC) curves were plotted for deciding the cut-off value for the height of the greater trochanter. The cut-off value presented the maximum sensitivity and specificity was determined. Results and Discussion. Fifty three THAs were operated without femoral shortening osteotomy, and twelve THAs were performed with femoral shortening osteotomy. The surgical time was significantly longer in the osteotomy group than the non-osteotomy group. The mean height of the tip of the greater trochanter were 53.2±11.4mm in the non-osteotomy group and 92.2±19.7 mm in the osteotomy group (Table 2). The cut-off value of the height of greater trochanter evaluated from the ROC curve analysis was 69.5mm (Fig.1). There were no significant differences in clinical score between two groups. More ratio of revisions and fractures were observed in the osteotomy group with significant differences. Conclusion. There were significant differences in postoperative complications in osteotomy group compare to non-osteotomy group. In cases with a greater trochanter tip height of 69.5 mm or less, it may be considered to avoid femoral shortening osteotomy

Background. The patients with high hip dislocation due to the sequelae of septic hip or neglected Developmental Dysplasia of the Hip (DDH) show severely impaired gait pattern. Total hip arthroplasty (THA) for these patients are expected to restore gait pattern by establishing better joint stability and biomechanics. To our knowledge, no study have investigated about objective change in gait parameters after total hip arthroplasty (THA) for these patients. So, we are to prospectively evaluate change in gait patterns after THA. Methods. Between 2012 and 2013, 11 patients with highly dislocated hip underwent unilateral THA with subtrochanteric osteotomy. There was 6 patients with DDH sequelae and 5 patients with septic hip sequelae. Spatio-temporal gait analysis was performed preoperatively and at 12 months after THA. We followed the patient 3, 6, 12 months and then annually postoperatively. The gait patterns were analyzed by several parameters such as cadence, speed, stride length, step length, step time, initial double support (IDS), terminal double support (TDS), stance phase and swing phase by a three-dimensional (3D) high-speed motion-capturing system (eight Eagle® cameras; Motion Analysis, Santa Rosa, CA, USA). Also dynamic range of motion (ROM) of hip joint and ground-reaction forces (GFR) were recorded. Clinical outcome was evaluated by using the Harris Hip Score (HHS). Radiographic assessments were evaluated for the changes in leg length discrepancy (LLD). Results. For operated limb, the mean period of TDS significantly increased from 8.6 % to 11.3 % respectively (p=0.038). As IDS, single support and TDS improved, mean period of stance phase increased from 54.4 % to 60.1 % of gait cycle and swing phase was relatively reduced from 45.4% to 39.9% (p=0.005) On the other hand, there were decrease in cadence, speed, step length on the affected limb postoperatively (p>0.05). In force graph, all patients showed significant increase of the peak force postoperatively. The first peak force (Fz1) was improved from 0.76 N (0.60 – 0.98) to 0.95 N (0.79 – 1.16) (p=0.007). The second peak force (Fz2) was improved from 0.70 N (0.44–0.96) to 0.94 N (0.85 – 1.14) (p=0.007). For the dynamic ROM, there were increase in sagittal plane motion and decrease in transverse and coronal plane. All of the changes were significantly not difference than preoperatively. Clinically, mean HHS was improved from 57.2 (range, 43–67) to 79.6 (range, 61–88) at last follow-up (p<0.05). In radiographic assessment, the patients showed 9.8 mm (range, 2.1 – 22.1) residual LLD at last follow-up. Conclusions. In the present study, patients with high hip dislocation who underwent primary THA showed improvement of gait pattern closer to that of normal hip joint. Although the patients showed improvement in gait analysis and clinical outcomes, but do not reach normal hip joint level and showed little residual antalgic gait pattern after THA

Background. Composite screws of uncalcined and unsintered hydroxyapatite (HA) particles and poly-l-lactide (PLLA) were developed as completely absorbable bone fixation devices. So far the durability of HA-PLLA composite screws is unclear when used for the fixation of acetabular bone graft in total hip arthroplasty under full-weight conditions. We have used this type of screw for the fixation of acetabular bone graft in cemented or reverse-hybrid total hip arthroplasty since 2003. Hence, we conducted a follow-up study to assess the safety and efficacy of these screws when used for cemented socket fixation. Methods. During 2003–2009, HA-PLLA composite screws were used for fixation of acetabular bone graft in cemented or reverse-hybrid primary THA in 106 patients (114 cases). All the THAs were performed through direct lateral approaches, and postoperative gait exercise with full weight bearing usually started two days after surgery. One patient died of an unrelated disease and seven patients were lost to follow-up within 5 years. Finally, 98 patients (106 cases) were followed up for over 5 years and were reviewed retrospectively (follow-up rate, 93%). Radiographic loosening of the acetabular component was assessed according to the criteria of Hodgkinson et al., and the radiolucent line around the socket was evaluated in all zones, as described by DeLee and Charnley. Results. The patient population comprised 10 men and 88 women with a mean age of 60.3 years (range, 41–81 years) at the time of surgery. The mean follow-up period was 7.6 years (range, 5–11 years). The original diagnosis for primary THA was secondary osteoarthritis in 97 cases and high hip dislocation in nine cases. No patient in this series required revision surgery, and no radiographical loosening occurred during the follow-up period. Grafted bone union was confirmed in all cases, and no apparent osteolysis around the cemented socket or composite screws was detected. Configurations of the HA-PLLA composite screws appeared obscure on radiographs at 5 years after surgery, and only osteosclerotic traces remained in the screw positions at the final follow-up. This finding was consistent in this series. The screw heads sometimes appeared to be broken with absorption within 3 years of surgery, and the remnants were identified in situ at the final follow up. Kaplan–Meier survival analyses with socket revision surgery for any reason, socket loosening, and appearance of a radiolucent line >1 mm in any zone as the endpoints yielded survival rates of 100%, 100%, and 86.8% at 5 years, and 100%, 100%, and 85.8% at 10 years, respectively. Conclusion. This absorbable screw seems to have no negative effects on the mid-term clinical results of cemented socket fixation

Aims

The Precice intramedullary limb-lengthening system has demonstrated significant benefits over external fixation lengthening methods, leading to a paradigm shift in limb lengthening. This study compares outcomes following antegrade and retrograde femoral lengthening in both adolescent and adult patients.