Modular Dual Mobility Constructs Used for Recurrent Hip Instability

Background

Recurrent hip dislocation despite prior attempts at surgical stabilization is a dreadful and technically challenging complication. A modular dual mobility (MDM) articulation has shown promise in addressing this problem, which might seem intractable. Our purpose was to examine the outcomes of revision total hip arthroplasty (THA) with an MDM placed through a direct anterior (DA) approach when all other conservative and surgical treatments have failed.

Methods

Fifteen patients revised with an MDM for recurrent instability (RI) between 2012 and 2018 by a single surgeon at a single institution were reviewed retrospectively, with a minimum of two years' follow-up. All patients underwent full acetabular revision with an MDM articulation through a DA approach with intraoperative fluoroscopy. No stems were revised. Dislocations, complications, and clinical outcomes are reported.

Results 

All patients had recurrent posterior instability with a mean number of 4 ± 2 (range: 2 to 8) dislocations prior to MDM revision THA (MDM rTHA). Eight patients had already failed surgical intervention for instability, and seven had failed repeated closed reductions and conservative care. After MDM rTHA, there were no dislocations at a mean follow-up of 4 ± 1 years (range: 2 to 8). Similarly, there were no further revisions or reoperations. Postoperatively, the mean cup inclination improved to 45 ± 2 degrees (range: 41 to 48), and the mean anteversion improved to 20 ± 2 degrees (range: 17 to 23). All cups were well-positioned utilizing fluoroscopic guidance. The mean effective head size increased from 32 mm to 44 mm. The mean hip disability and osteoarthritis disability score (HOOS, Jr) was 73 ± 25% (range: 40 to 100).

Conclusion

Refractory hip instability in THA may be effectively managed with an MDM articulation, even when prior attempts at surgical stabilization have failed. Intraoperative imaging and a direct anterior approach may aid the challenges of implant positioning and achieving hip stability in a revision setting.

Returning to Yoga Practice and Teaching After Total Hip Arthroplasty

Patients who practice yoga are motivated to return to practice after total hip arthroplasty (THA). With case reports of dislocations during yoga, the safety of such a return is unclear. The purpose of this study is to examine the timing and feasibility of a return in a subset of highly experienced and motivated patients. Between 2010 and 2019, a total of 19 THA’s performed in 14 patients who self-identified as yoga instructors were retrospectively reviewed. Patients who practiced yoga but were not teachers were excluded from this series. The primary outcome measures were the ability to return to yoga, to resume teaching, and fluency with 14 classic poses. Secondary outcomes measured were patient-reported Hip Disability and Osteoarthritis Outcome Score (HOOS, Jr.), complications, and radiographic position of the implants. After surgery, all patients returned to practicing and teaching yoga, and the mean time to each was 2 months. All patients were able to perform all 14 classic poses. At a mean follow-up of 5 years (SD ± 4), there were no complications, and the mean HOOS, JR score was 92 points (SD ± 15). This study demonstrates that a return to yoga in an experienced population is not only possible but also safe after a direct anterior THA. Limitations in performing the poses should be understood, and appropriate modifications should be incorporated when needed.

Aseptic Loosening of Smaller Corail Stems in Heavy, Active Males: A Report of Three Cases

Recent concerns have been raised regarding a higher failure rate with smaller size Corail stems. This case series examines early aseptic loosening with smaller stems in three large male patients with Dorr A bone. Each stem was fluoroscopically aligned and sized until stable with axial and rotational stress. In each case, failure occurred within six months due to symptomatic metaphyseal debonding. Careful analysis suggests a correlation of failure to small size stems that are comparatively 1) undersized relative to the metaphysis, 2) undersized relative to patient body mass index, and 3) undersized relative to the amount of offset created.

Managing Protrusio Acetabuli With a Direct Anterior Approach Total Hip Replacement

Introduction

The deformities of protrusio acetabuli (PA) present unique reconstructive challenges. An incarcerated femoral head, medialized center of rotation, deficient bone stock, and associated leg length discrepancy add significant technical complexity to total hip arthroplasty (THA).

Methods

We retrospectively reviewed 23 THAs in 21 patients with PA who underwent direct anterior (DA) approach THA with intraoperative fluoroscopy. All acetabular defects were reconstructed with morcellized femoral head autograft using Bone Mill (Stryker Corporation, Kalamazoo, MI).

Results

The mean AK distance preoperatively was 8 mm (range: 1-16). Postoperatively, the degree of protrusio improved in all cases, and the mean AK distance decreased to 0 mm. All bone grafts consolidated, and no cups loosened or were revised at a mean of 5.3 years of follow-up. The mean Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS, JR) at follow-up was 91.

Conclusions

These data suggest that the DA approach with intraoperative fluoroscopy may be a reasonable technique in the surgical management of this challenging population.

Two new cases of the Christchurch (Ch1) chromosome 21: evidence for clinical consequences of de novo deletion 21P-

We performed an investigation of two unrelated cases with extremal variants of chromosome 21 without visible materials of the short arms (Christchurch or Ch1 chromosome). In the first case chromosome 21p- was initially detected during routine cytogenetic amniocentesis. Chromosomal variant was inherited from phenotypically normal father to phenotypically normal fetus (phenotypically normal boy after the birth). The second case of chromosome 21p- was detected in 7 years old boy, referred to cytogenetic analysis due to mental retardation and mild congenital malformation, including prenatal hypoplasia, microcephaly, low-set dysplastic ears, short nose, micrognatia, short neck. Molecular characterization of 21p-variant chromosomes was performed by the use of FISH with DNA probes specific to the short arm and centromeric region of chromosome 21 (telomeric, beta-satellite, ribosomal, classical satellite and alphoid DNA probes). Chromosomes 21p-hybridized positively only with telomeric DNA at both chromosomal ends and alphoid DNA probes at centromeric region of the first patient. In second case (de novo deletion of 21p), the Ch1 was associated with clinical phenotype and loss of telomeric and subtelomeric DNA in the p-arm of chromosome 21. Therefore, the complete absent of the short arm of chromosome 21 may be considered as abnormal. We propose that de novo deletion 21p- could have negative consequences due to absence of large portion of chromosomal DNA from the p-arm (telomeric, satellite or ribosomal DNAs) and following imbalance in organization and functioning of genome.

Are clinical and biological IVF parameters correlated with chromosomal disorders in early life: a multicentric study

A multicentric study was carried out to analyse in a large series: (i) the chromosomal status of unfertilized oocytes, (ii) errors at fertilization and (iii) the chromosomal complement of cleaved embryos. Parameters such as type of sterility, maternal age, stimulation treatment, doses of gonadotrophins administered and oocyte preincubation time before insemination were studied in relation to the incidence of chromosome abnormalities. Twenty-six per cent of the unfertilized oocytes and 29.2% of the embryos had chromosome anomalies. Maternal age significantly increased the rate of aneuploidy in oocytes: 38% in patients over 35 years (versus 24% in younger patients). Fertilization-related abnormalities were significant, i.e. 1.6% parthenogenesis and 6.4% polyploidy. Unexplained infertility was correlated with an increase in the rate of parthenogenesis (4.2%) when compared with tubal infertility (1.2%). Triploidy was found to be correlated with three parameters. A lower rate of triploidy was observed in the group of couples referred because of male sterility (1.9% versus 6.3% for tubal sterility), in HMG-treated patients (2.4% versus 7% with analogues of LHRH/HMG) and with a short 2-h preincubation time before insemination (3% versus 7.2% for greater than 2 h). A general model for natural selection against embryos carrying a chromosome imbalance was proposed.