Varus mal-alignment and residual displacement are associated with delayed union in subtrochanteric femur fracture- A retrospective observational study.

Background: Subtrochanteric femoral (ST) fractures are associated with high rates of delayed and non-union. The aim of this study was to analyse the risk factors associated with delayed/non-union in ST fractures. Methods: All patients with surgical stabilisation of ST fractures during the period 2014 to 2019 were identified in an electronic patient records database in two trauma centres. Exclusion criteria were incomplete clinical/radiological data, pathological fractures and loss to follow-up. Radiographs at about 6 months post-surgery were assessed for fracture union using Radiographic Union Score for Hip (RUSH). Fracture was deemed to be un-united if RUSH score was <18. CCD (caput-collum-diaphyseal) angle of operated and uninjured hip, residual displacement at fracture site and 3-point relationship was calculated on operative or immediate post-operative images in both groups. Student's t-test was used to compare CCD angle difference between operated and uninjured sides and the residual fracture displacement between delayed union and united fractures group. Chi-square test was used for 3-point relationship. Observational analysis was performed on implant failure rates including distal screw breakage. Results: During the study period, there were total of 278 patients. 193 with inadequate data and 22 with pathological fractures were excluded. Advanced age and female sex had significantly higher rate of delayed union (p value of 0.043 and 0.003 respectively). Delayed union group (26) had a mean RUSH score of 14.1 and united group (37) had a mean RUSH score of 26.3 (p = 0.019). The mean CCD angle difference between operated and uninjured sides was -5.77° for delayed union and -2.33° for united fractures (p = 0.03). Residual displacement at fracture site showed statistically significant difference between delayed union and united fractures on anteroposterior and lateral views (p = 0.001 each). There was no statistical difference in 3-point relationship of implant in two groups (p = 0.775). 10 revision procedures were performed for implant failures. Distal screw failure (3 cases) was not a precursor for non-union in this study. Conclusion: This study confirms varus alignment of hip and residual fracture displacement after fracture fixation of subtrochanteric fracture are surgeon associated significant risk factors for delayed union at 6 months. Fracture contact and alignment are key to reduce failures in these group of fractures. Among patient factors, advancing age and female sex predisposes to higher rate of delayed union.

Withdrawn: A Randomized Controlled Trial Comparing Modular and Nonmodular Neck Versions of a Titanium Stem.

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Medium-term results following large diameter metal-on-metal total hip arthroplasty: increasing failure after 6 years.

PURPOSE: The main aim of our study is to report the medium-term survivorship of Birmingham Hip Resurfacing (BHR) cup and a large modular metal head (MMT) on an uncemented Freeman femoral stem. No results have been reported till date with these implants combinations. METHODS: A total of 205 metal-on-metal total hip replacements (MoM THRs) were performed on 190 patients from October 2002 to November 2004. Prior to the Medicines and Healthcare Products Regulatory Agency (MHRA) guidelines, the patients were followed up at 3, 6 and 12 months postoperatively and annually thereafter. Following the MHRA alert in 2010, the patients were followed-up as per the MHRA guidelines.All statistical analyses were conducted using Stata 13. RESULTS: At a mean follow-up of 10.5 years, a total of 42 out of 205 hips were revised for reasons related to ALTR. The failure rates increased significantly over time (7% at 6 years and 29% at 10-year follow-up). The analysis showed no statistically significant association to age, gender, side, BMI or component size or position (p<0.05). Blood metal ions showed a poor discriminant ability to separate failed from well-functioning MoM hip replacements. CONCLUSIONS: Large head MoM BHR on an uncemented stem has extremely high failure rate. The authors do not recommend the use of large head MoM articulation in total hip arthroplasty in the wake of this report and similar findings across the world. Continued surveillance of these implants is required as the failure rates increase with time.

Vitamin D and oestrogen receptor polymorphisms in developmental dysplasia of the hip and primary protrusio acetabuli--a preliminary study.

We investigated the association of developmental dysplasia of the hip (DDH) and primary protrusion acetabuli (PPA) with Vitamin D receptor polymorphisms Taq I and Fok I and oestrogen receptor polymorphisms Pvu II and Xba I. 45 patients with DDH and 20 patients with PPA were included in the study. Healthy controls (n = 101) aged 18-60 years were recruited from the same geographical area. The control subjects had a normal acetabular morphology based on a recent pelvic radiograph performed for an unrelated cause. DNA was obtained from all the subjects from peripheral blood. Genotype frequencies were compared in the three groups. The relationship between the genotype and morphology of the hip joint, severity of the disease, age at onset of disease and gender were examined. The oestrogen receptor Xba I wild-type genotype (XX, compared with Xx and xx combined) was more common in the DDH group (55.8%) than controls (37.9%), though this just failed to achieve statistical significance (p = 0.053, odds ratio = 2.1, 95% CI = 0.9-4.6). In the DDH group, homozygosity for the mutant Taq I Vitamin D receptor t allele was associated with higher acetabular index (Mann-Whitney U-test, p = 0.03). Pvu II pp oestrogen receptor genotype was associated with low centre edge angle (p = 0.07). This study suggests a possible correlation between gene polymorphism in the oestrogen and vitamin D receptors and susceptibility to, and severity of DDH. The Taq I vitamin D receptor polymorphisms may be associated with abnormal acetabular morphology leading to DDH while the Xba I oestrogen receptor XX genotype may be associated with increased risk of developing DDH. No such correlations were found in the group with PPA.

Fracture strain and stability with additional locking screws in intramedullary nailing: a biomechanical study.

BACKGROUND: We studied the effect of additional locking screws on fracture strain and stability in tibial intramedullary nailing. METHODS: We drilled an additional diaphyseal locking hole into 8-mm solid tibial nails 185 mm from the proximal end of the nail, and locked it proximally and distally. An osteotomy was produced 4.5 cm distal to the additional hole, and the construct loaded axially, in flexion, extension, and torsion. The nails were also tested for their fatigue strength. RESULTS: With the additional locking screw, strain increased proximally during loading in neutral and flexion. Strain decreased on loading in extension. The extra locking screw decreased strain close to the osteotomy site in all loading positions. A significant reduction in angular motion at the osteotomy site occurred with the addition of the extra locking screw. The nails survived the fatigue test, although the stress increased around the additional locking hole CONCLUSIONS: Nails with additional locking options, by altering strain and motion at the fracture site, may have the clinical potential to affect fracture healing.

Unexpected long femur in adults with acetabular dysplasia.

Femoral length symmetry is assumed when assessing a patient with a dysplastic acetabulum. An unexpected long femur has been observed in some adults with acetabular dysplasia. We undertook a retrospective observation study of 18 adults with unilateral and 11 adults with bilateral acetabular dysplasia. Femoral lengths were assessed using CT measurements. The ipsilateral femur was found to be 5-10 mm longer in 66% (12 patients) with unilateral dysplastic acetabulae. Femoral lengths varied greatly in the presence of bilateral dysplastic acetabulae. In the presence of a acetabular dysplasia, asymmetry of femoral lengths is common and unpredictable. Femoral and total limb length assessment (with CT) is advised preoperatively. This will alert the surgeon and patient to the possible risk of post operative ipsilateral limb lengthening.

Femoral cement pressurization in hip arthroplasty: a laboratory comparison of three techniques.

BACKGROUND: Several cementing techniques are used for the proximal femur. MATERIAL AND METHODS: We evaluated 3 femoral cement pressurization techniques (standard, pressurizer in situ, and thumb pressurization) in 12 plastic femurs, with 4 sets of observations for each technique. Intramedullary pressure readings were obtained using proximal and distal pressure monitoring transducers. The peak pressure and the length of time for which the pressure was above a particular cutoff level (5 KPa and 100 KPa) were compared for the different techniques. RESULTS: We found significant differences between the 3 cementing techniques in the peak pressure and the length of time for which the pressure was above 100 KPa. The pressurizer in situ technique gave higher peak pressure (p < 0.001), both proximally (398) and distally (597). The standard technique produced a pressure of 100 KPa for a longer duration, both proximally and distally (mean 67 sec and 45 sec, p < 0.001) compared to the other two techniques (less than 5 and 17 sec for the thumb pressurization technique and the pressurizer in situ technique, respectively, both proximally and distally). Although the pressurizer in situ technique produced the highest peak pressure, the standard technique produced an optimum pressure of longer duration. INTERPRETATION: The standard technique appears to be adequate for achievement of optimum pressurization during femoral cementing without increased risk of embolization.

Infective lumbar discitis following laparascopic sacrocolpopexy.

STUDY DESIGN: A case report of infective lumbar discitis following laparoscopic sacrocolpopexy. OBJECTIVES: To improve awareness of the possibility of surgical procedures for genital prolapse causing discitis by presenting a case history. BACKGROUND: Infective lumbar discitis following laparoscopic sacrocolpopexy is very rare. METHODS: Case history of a 63 year old lady who developed infective L5-S1 discitis three weeks following a laparoscopic sacrocolpopexy. CONCLUSION: Discitis following a laparoscopic sacrocolpopexy procedure is a very rare but significant complication.