Ligamentum Teres Tears and Increased Combined Anteversion Are Associated With Hip Microinstability in Patients With Borderline Dysplasia.

PURPOSE: To investigate the differences in the prevalence of ligamentum teres (LT) tears and other radiographic measurements in borderline dysplasia of the hip (BDDH) with/without microinstability and to evaluate the associations between these imaging findings and the prevalence of microinstability in patients with BDDH. METHODS: This was a retrospective study of symptomatic patients with BDDH (18° ≤ lateral center-edge angle <25°) treated with arthroscopy in our hospital between January 2016 and December 2021. These patients were divided into the BDDH with microinstability (mBDDH) group and the stable BDDH (nBDDH) group. The radiographic parameters associated with hip joint stability, such as the state of LT, acetabular versions, femoral neck version, Tönnis angle, combined anteversions, and anterior/posterior acetabular coverage, were reviewed and analyzed. RESULTS: There were 54 patients (49 female/5 male, 26.7 ± 6.9 years) in the mBDDH group and 81 patients (74 female/7 male, 27.2 ± 7.7 years) in the nBDDH group. The mBDDH group had greater LT tear (43/54 vs 5/81) and general laxity rates, increased femoral neck version, acetabular version and combined anteversion (52.4 ± 5.9 vs 41.5 ± 7.1 at 3-o'clock level) than the nBDDH group. Binary logistic regression showed that LT tears (odds ratio 6.32, 95% confidence interval 1.38-28.8; P = .02; R2 = .458) and combined anteversion at the 3-o'clock level (odds ratio 1.42, 95% confidence interval 1.09-1.84; P < .01; R2 = .458) were independent predictors of microinstability in patients with BDDH. The cutoff value of combined anteversion at 3-o'clock level was 49.5°. In addition, LT tear was correlated with increased combined anteversion at 3-o'clock level in patients with BDDH (P < .01, η2 = 0.29). CONCLUSIONS: LT tears and increased combined anteversion at the 3-o'clock level on the acetabular clockface were associated with hip microinstability in patients with BDDH, suggesting that patients with BDDH and LT tears might have a greater prevalence of anterior microinstability. LEVEL OF EVIDENCE: Level III, case‒control study.

What Factors Are Associated With Postoperative Ischiofemoral Impingement After Bernese Periacetabular Osteotomy in Developmental Dysplasia of the Hip?

BACKGROUND: Any abnormal structures that contribute to the narrowing of the ischiofemoral space could induce ischiofemoral impingement. Bernese periacetabular osteotomy (PAO) medializes the hip center and, therefore, decreases contact stress on the cartilage in developmental dysplasia of the hip (DDH). However, medialization of the hip center might also narrow the ischiofemoral space, which may increase the risk of postoperative ischiofemoral impingement in patients with acetabular dysplasia who are undergoing PAO. Furthermore, the dysplastic hip has less ischiofemoral space and less space for the quadratus femoris. A few studies have focused on the amount of medialization of the hip center, but the proportion of postoperative ischiofemoral impingement after PAO has not been investigated. QUESTIONS/PURPOSES: (1) What proportion of patients develop ischiofemoral impingement after undergoing unilateral PAO for DDH? (2) What radiographic factors are associated with postoperative ischiofemoral impingement in patients who underwent PAO for DDH? (3) How much hip center medialization is safe so as to avoid postoperative ischiofemoral impingement during PAO? METHODS: Between 2014 and 2016, we treated 265 adult patients who had symptomatic residual acetabular dysplasia (lateral center-edge angle less than 20°) using PAO. During that time, we generally offered PAO to patients with acetabular dysplasia when the patients had no advanced osteoarthritis (Tönnis grade < 2). Of those, we considered only patients who underwent primary PAO without femoral osteotomy as potentially eligible. Based on that, 65% (173 of 265) were eligible; a further 9% (24 of 265) were excluded due to leg length discrepancy, spine disorders, or joint replacement in the contralateral side, and another 6% (17 of 265) of patients were lost before the minimum study follow-up of 2 years or had incomplete datasets, leaving 50% (132 of 265) for analysis in this retrospective study at a mean of 2.70 ± 0.71 years. The diagnosis of ischiofemoral impingement was defined by symptoms, MRI, and diagnostic ischiofemoral injection. We ascertained the percentage of patients with this diagnosis to answer the first research question. To answer the second question, we divided the patients into two groups: PAO patients with ischiofemoral impingement and PAO patients without ischiofemoral impingement. The demographic data and preoperative imaging parameters of patients in both groups were compared. There were statistical differences in acetabular version, ischial angle, neck-shaft angle, the presence of positive coxa profunda sign, McKibbin index, ischiofemoral space, quadratus femoris space, anterior acetabular section angle, and the net amount of hip center medialization. To investigate potential factors associated with postoperative ischiofemoral impingement in patients who underwent PAO, these factors underwent binary logistic regression analysis. To answer the third question, the cutoff value of the net amount of hip center medialization was evaluated using receiver operator characteristic curve and the Youden index method. RESULTS: We found that 26% (35 of 132) of PAO dysplastic hips had postoperative ischiofemoral impingement. After controlling for confounding variables such as acetabular version, ischial angle, femoral neck version, McKibbin index, and ischiofemoral space, we found that an increasing neck-shaft angle (odds ratio 1.14 [95% confidence interval 1.01 to 1.29]; p = 0.03), a positive coxa profunda sign (OR 0.13 [95% CI 0.03 to 0.58]; p < 0.01), and an increasing net amount of hip center medialization (OR 2.76 [95% CI 1.70 to 4.47]; p < 0.01) were associated with postoperative ischiofemoral impingement in patients with DDH who underwent PAO (R 2 = 0.73). The cutoff values of neck-shaft angle was 138.4°. The cutoff values of the net amount of hip center medialization was 1.9 mm. CONCLUSIONS: Postoperative ischiofemoral impingement could occur in patients with acetabular dysplasia who have undergone PAO after hip center medialization. An increasing neck-shaft angle, a positive coxa profunda sign on preoperative imaging, and excessive medialization of the hip center are factors associated with ischiofemoral impingement development in these patients. Therefore, we suggest that physicians measure the ischiofemoral space on a preoperative CT when patients with DDH have an increasing neck-shaft angle (> 138.4°) or a positive coxa profunda sign on radiological imaging. During PAO, the amount of hip center medialization should be carefully controlled to keep these patients from developing postoperative ischiofemoral impingement. LEVEL OF EVIDENCE: Level III, therapeutic study.

Increased Combined Anteversion Is an Independent Predictor of Ischiofemoral Impingement in the Setting of Borderline Dysplasia With Coxa Profunda.

PURPOSE: To investigate the differences in radiologic parameters between borderline dysplasia hips (BDDH) +/- coxa profunda and normal hips and to evaluate the correlations between these parameters and the prevalence of ischiofemoral impingement (IFI) in borderline dysplasia. METHODS: The imaging of patients with BDDH (18° ≤ lateral center edge angle <25°) treated in our hospital from January 2018 to December 2019 was retrospective reviewed. These patients were divided into BDDH with coxa profunda (acetabular fossa touches the ilioischial line, pBDDH) and without coxa profunda (nBDDH) groups. The groups were compared with a control group with normal acetabular coverage. Neck-shaft angle, femoral offset, acetabular versions, acetabular coverage, ischial angle, femoral neck version, and combined anteversion were reviewed and analyzed using computed tomography imaging using one-way analysis of variance. RESULTS: There were 43 patients (36 female/7 male, 26.13 ± 4.96 years) in the pBDDH group, 22 patients (17 female/5 male, 28.60 ± 5.89 years) in the nBDDH group, and 23 patients (14 female/9 male, 27.67 ± 5.98 years) in the control group. The pBDDH group had increased femoral version, ischial angle, acetabular versions, and decreased ischiofemoral space (IFS)/quadratus femoris space (QFS) than the other 2 groups. The IFS/QFS correlated with neck-shaft angle, femoral offset, femoral neck version, acetabular versions, ischial angle, femoral neck-lesser trochanter angle, posterior acetabular coverage, and combined anteversion in patients with BDDH. Combined anteversion at the 3-o'clock level was an independent predictor of a decreased IFS (beta = -0.348, P = .007) and QFS (beta = -0.255, P = .01, R2 = .550). Binary logistic regression demonstrated that patients with BDDH with large combined anteversion at the 3-o'clock level had a greater prevalence of IFI (odds ratio 1.148; P = .001, R2 = .505). CONCLUSIONS: In patients with borderline dysplasia, the QFS/IFS significantly correlated with combined anteversion at the 3-o'clock level on clock face of acetabulum. BDDH with coxa profunda might have a greater prevalence of IFI because of large combined anteversion. LEVEL OF EVIDENCE: III, retrospective comparative observation study.

Outcomes After Management of Subspine and Femoroacetabular Impingement Using a Direct Anterior Mini-Open Approach.

BACKGROUND: Subspine impingement (SSI) has been commonly managed with arthroscopic decompression. However, arthroscopic decompression is a demanding technique, as under- or over-resection of the anterior inferior iliac spine (AIIS) could lead to inferior outcomes. An anterior mini-open approach has also been used in the management of femoroacetabular impingement (FAI), and it could provide adequate visualization of the anterior hip joint without a long learning curve. PURPOSE/HYPOTHESIS: The objective of the current study was to compare the outcomes of SSI patients with FAI who underwent arthroscopic subspine decompression and osteoplasty with a group undergoing subspine decompression and osteoplasty using a modified direct anterior mini-open approach. It was hypothesized that there would be no significant difference in outcomes between the groups. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We reviewed the records of SSI patients who underwent decompression surgery (arthroscopic or mini-open) at our institution from June 1, 2015 to December 31, 2016. Both groups underwent the same postoperative rehabilitation protocol. Preoperative and 2-year postoperative patient-reported outcomes were compared using the modified Harris Hip Score (mHHS), International Hip Outcome Tool-33 (iHOT-33), and Hip Outcome Score-Activities of Daily Living (HOS-ADL). Major and minor complications as well as reoperation rates were recorded. RESULTS: Included were 47 patients (49 hips) who underwent subspine decompression using an anterior mini-open approach and 35 patients (35 hips) who underwent arthroscopic subspine decompression. There were no differences in demographic and radiological parameters between the groups, and patients in both groups showed significant improvement in all outcome scores at follow-up. The pre- to postoperative improvement in outcome scores was also similar between groups (mini-open vs arthroscopy: mHHS, 26.30 vs 27.04 [P = .783]; iHOT-33, 35.76 vs 31.77 [P = .064]; HOS-ADL, 26.09 vs 22.77 [P = .146]). In the mini-open group, 10 of the 47 patients had temporary meralgia paresthetica, and fat liquefaction was found in 1 female patient. There were no reoperations in the mini-open group. CONCLUSION: Subspine decompression using the anterior mini-open approach had similar outcomes to arthroscopic decompression in the management of SSI. The lateral femoral cutaneous nerve should be protected carefully during use of the anterior mini-open approach.

Crystal structure of catena-poly[[[aqua-bis-(1H-imidazole-κN (3))copper(II)]-µ-3-({4-[(2-carboxyl-atoeth-yl)carbamo-yl]phen-yl}formamido)-propano-ato-κ(2) O:O'] dihydrate].

In the title polymeric complex, {[Cu(C14H14N2O6)(C3H4N2)2(H2O)]·2H2O} n , the Cu(II) cation, located on a twofold rotation axis, is coordinated by one water mol-ecule and two imidazole mol-ecules as well as two symmetry-related 3-([4-[(2-carboxyl-atoeth-yl)carbamo-yl]phen-yl]formamido)-propano-ate dianions (L (2-)) in an approximately square-pyramidal geometry. The coordinating water mol-ecule is located on a twofold rotation axis while the L (2-) anion sits about an inversion center. The L (2-) anions bridge the Cu(II) cations, forming polymeric chains propagating along the [101] direction. In the crystal, O-H⋯O, N-H⋯O hydrogen bonds and weak C-H⋯π inter-action link the polymeric chains and the solvent water mol-ecules into a three-dimensional supra-molecular architecture.