Size and shape of the lunate surface differs substantially among different types of pincer impingement. In contrast to hips with protrusio acetabuli, retroverted and deep hips do not have an increased size of the lunate surface. Acetabular rim trimming in retroverted and deep hips should be performed with caution. Based on our results, acetabular reorientation would theoretically be the treatment of choice in retroverted hips.

Hips with synovial chondromatosis may present with clinical and radiographic features resembling those of cam-type femoroacetabular impingement. As simultaneous treatment of both conditions is best accomplished with surgical hip dislocation rather than other, less-extensive surgical approaches, we recommend preoperative consideration of synovial chondromatosis in patients presenting with unilateral cam-type femoroacetabular impingement.

III.

Background THA for high-riding developmental dysplasia of the hip (DDH) is challenging in terms of length equalization. Although previous studies suggested preoperative templating on AP pelvic radiographs is insufficient in patients with unilateral high-riding DDH because of hypoplasia of the hemipelvis on the affected side and unequal femoral and tibial length on scanograms, the results were controversial. The EOS™ (EOS™ Imaging) is a biplane X-ray imaging system using slot-scanning technology. Length and alignment measurements have been shown to be accurate. We used the EOS to compare the lower limb length and alignment in patients with unilateral high-riding DDH. Questions/purposes (1) Is there an overall leg length difference in patients with unilateral Crowe Type IV hip dysplasia? (2) In patients with unilateral Crowe Type IV hip dysplasia with an overall leg length difference, is there a consistent pattern of abnormalities in the femur or tibia that account for observed differences? (3) What is the impact of unilateral high-riding Crowe Type IV dysplasia on femoral neck offset and knee coronal alignment? Methods Between March 2018 and April 2021, we treated 61 patients with THA for Crowe Type IV DDH (high-riding dislocation). EOS imaging was performed preoperatively in all patients. Eighteen percent (11 of 61) of the patients were excluded because of involvement of the opposite hip, 3% (two of 61) were excluded for neuromuscular involvement, and 13% (eight of 61) had previous surgery or fracture, leaving 40 patients for analysis in this prospective, cross-sectional study. Each patient’s demographic, clinical, and radiographic information was collected with a checklist using charts, Picture Archiving and Communication System, and an EOS database. EOS-related measurements that were related to the proximal femur, limb length, and knee-related angles were recorded for both sides by two examiners. The findings of the two sides were statistically compared. Results The overall limb length was not different between the dislocated and nondislocated sides (mean 725 ± 40 mm versus 722 ± 45 mm, mean difference 3 mm [95% CI -3 to 9 mm); p = 0.08). Apparent leg length was shorter on the dislocated side (mean 742 ± 44 mm versus 767 ± 52 mm, mean difference -25 mm [95% CI -32 to 3 mm]; p < 0.001). We observed that a longer tibia on the dislocated side was the only consistent pattern (mean 338 ± 19 mm versus 335 ± 20 mm, mean difference 4 [95% CI 2 to 6 mm]; p = 0.002), but there was no difference between the femur length (mean 346 ± 21 mm versus 343 ± 19 mm, mean difference 3 mm [95% CI -1 to 7]; p = 0.10). The femur of the dislocated side was longer by greater than 5 mm in 40% (16 of 40) of patients and shorter in 20% (eight of 40). The mean femoral neck offset of the involved side was shorter than that of the normal side (mean 28 ± 8 mm versus 39 ± 8 mm, mean difference -11 mm [95% CI -14 to -8 mm]; p < 0.001). There was a higher valgus alignment of the knee on the dislocated side with a decreased lateral distal femoral angle (mean 84° ± 3° versus 89° ± 3°, mean difference - 5° [95% CI -6° to -4°]; p < 0.001) and increased medial proximal tibia angle (mean 89° ± 3° versus 87° ± 3°, mean difference 1° [95% CI 0° to 2°]; p = 0.04). Conclusion A consistent pattern of anatomic alteration on the contralateral side does not exist in Crowe Type IV hips except for the length of the tibia. All parameters of the limb length could be shorter, equal to, or longer on the dislocated side. Given this unpredictability, AP pelvis radiographs are not sufficient for preoperative planning, and individualized preoperative planning using full-length images of the lower limbs should be performed before arthroplasty in Crowe Type IV hips. Level of Evidence Level I, prognostic study.

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: Several pelvic osteotomy techniques are introduced for the treatment of Developmental Dysplasia of the Hip (DDH). However, there is no agreement on the optimal pelvic osteotomy in DDH. Thus, this study aimed to compare the outcomes of Pemberton Osteotomy (PO) and the Kalamchi Modification of Salter Osteotomy (KMSO). Objectives: Comparison of pemberton osteotomy and kalamchi modification of salter osteotomy in the treatment of developmental dysplasia of the hip. Methods: In a retrospective study, radiographic and clinical outcomes as well as surgical complications were compared between the patients who underwent unilateral DDH surgery using either KMSO or PO. The radiographic measures included the assessment of the acetabular index and the Shenton line. The clinical results of the osteotomies were evaluated by McKay’s criteria modified by Berkeley et al. Also, Kalamchi and MacEwen’s classification was used for the assessment of avascular necrosis. Results: The characteristic features of the patients, such as age and follow-up time, were statistically comparable between the two study groups. One year after the surgery, the Shenton line was intact in 55 patients (84.6%) of the KMSO group and 40 patients (88.9%) of the PO group (P=0.52). The Mean±SD value of the acetabular index was 21.1±5.1 and 20.7±3.9 in the KMSO and PO groups, respectively (P=0.13). Besides, the McKay’s clinical criteria were respectively excellent, good, and fair in 44, 16, and 5 patients (67.7%, 24.6%, and 7.7%, respectively) of the KMSO group, and 31, 12, and 2 patients (70%, 26.6%, and 4.4%, respectively) of the PO group (P=0.4). Moreover, the number of postoperative avascular necrosis did not significantly differ between the two study groups. Conclusion: The PO and KMSO techniques are equally safe and effective osteotomies in the treatment of DDH and can be used interchangeably.

Background: Vascular thromboembolism is one of the major concerns of orthopedic surgeons after hip or knee replacement surgery. Although many thromboprophylactic drugs have been introduced, there is still no consensus over their efficacy and safety. Therefore, this study aimed to compare the efficacy and safety of oral rivaroxaban and aspirin administration and enoxaparin injections in patients undergoing knee or hip replacement. Objectives: Determination and comparison of the side effect and efficacy of Rivaroxaban and Enoxaparin after total hip or knee arthroplasty. Methods: A total of 231 patients undergoing knee or hip replacement surgery were included in the study. Of them, 31 patients were excluded due to missing the follow-up. Of the remaining 200 patients, 42 low-risk and 158 moderate- to high-risk patients were identified, according to Caprini risk assessment model. Then, they were divided into three groups: aspirin (42 patients), enoxaparin (78 patients), and rivaroxaban (80 patients). Severe hemorrhage (hemoglobin reduction of more than 2 g/dL or requiring blood transfusion) was assessed after the first dose of medication until discharge through daily hemoglobin testing. Frequency of other side effects such as wound complications (ecchymosis, hematoma, and wound infection) and gastrointestinal or skin problems was recorded and compared by daily examination during the hospital stay and then in the future visits to the clinic up to 6 months in each group. Follow up visits were performed at weeks 6, 12, and 24. Results: No cases of deep vein thrombosis or pulmonary thromboembolism were observed in any of the study groups. There was no significant difference between the two groups in the number of major bleeding cases (P=0.39). Ecchymosis around the wound was significantly higher in the rivaroxaban group than in the enoxaparin group (33.8% vs. 23%). However, this difference was not statistically significant (P=0.06). Conclusion: The efficacy and safety of rivaroxaban and enoxaparin drugs are comparable. Although ecchymosis was seen after using rivaroxaban rather than enoxaparin, rivaroxaban is orally administered and costs less for the patient and the health system. So, its use as a thromboprophylactic drug of choice following hip and knee arthroplasty surgery is still recommended.

Background: An increased incidence of osteonecrosis of the femoral head (ONFH) has recently been observed in Iran, likely associated with the introduction of an illegal, steroid-containing opioid drug, Temgesic. The correlation of risk factors associated with the course of ONFH has yet to be determined. Objectives: The purpose of the present study was to assess the effects of etiologic factors on the course of ONFH after emergence of symptoms. Patients and Methods:We retrospectively assessed patients with untreated ONFH due to one of the four etiologies of steroid medication, Temgesic abuse, trauma and idiopathic. Patients with multiple risk factors and those without collapse at the last follow-up visit were excluded. The effect of age, gender, etiology of osteonecrosis, opium addiction and smoking on the time interval between pain onset and radiologic collapse were investigated. Results: In total, 110 patients (174 hips) were categorized into four etiologic groups. The average time between onset of pain to radiologic collapse in different etiologic groups was 12.8 months for all groups, 12.4 months for steroid, 8.7 months for Temgesic, 18.5 months for trauma and 16.6 months for idiopathic groups. Thirteen hips had collapse in less than six months. Patients who used steroid and Temgesic had shorter time interval to collapse, which was statistically significant (P Values < 0.001 and < 0.001, respectively). Smoking had a statistically significant association with the time to femoral head collapse (P Value = 0.003). Conclusions: Steroid medications and Temgesic abuse are associated with shorter time interval to femoral head collapse. Smoking is also a factor associated with shorter time interval to collapse. These factors should be considered in any joint preserving treatments for patients with FHON.