Aims

This study aimed to determine whether lateral femoral wall thickness (LWT) < 20.5 mm was associated with increased revision risk of intertrochanteric fracture (ITF) of the hip following sliding hip screw (SHS) fixation when the medial calcar was intact. Additionally, the study assessed the association between LWT and patient mortality.

The lateral wall thickness (LWT) in trochanteric femoral fractures is a known predictive factor for postoperative fracture stability. Currently, the AO/OTA classification uses a patient non-specific measure to assess the absolute LWT (aLWT) and distinguish stable A1.3 from unstable A2.1 fractures based on a threshold of 20.5 mm. This approach potentially results in interpatient deviations due to different bone morphologies and consequently variations in fracture stability. Therefore, the aim of this study was to explore whether a patient-specific measure for assessment of the relative LWT (rLWT) results in a more precise threshold for prediction of unstable fractures. Part 1 of the study evaluated 146 pelvic radiographs to assess left-right symmetry with regard to caput-collum-angle (CCD) and total trochanteric thickness (TTT), and used the results to establish the rLWT measurement technique. Part 2 reevaluated 202 patients from a previous study cohort to analyze their rLWT versus aLWT for optimization purposes. Findings in Part 1 demonstrated a bilateral symmetry of the femur regarding both CCD and TTT (p ≥ 0.827) allowing to mirror bone's morphology and geometry from the contralateral intact to the fractured femur. Outcomes in Part 2 resulted in an increased accuracy for the new determined rLWT threshold (50.5%) versus the standard 20.5 mm aLWT threshold, with sensitivity of 83.7% versus 82.7% and specificity 81.3% versus 77.8%, respectively. The novel patient-specific rLWT measure can be based on the contralateral femur anatomy and is a more accurate predictor of a secondary lateral wall fracture in comparison to the conventional aLWT. This study established the threshold of 50.5% rLWT as a reference value for prediction of fracture stability and selection of an appropriate implant for fixation of trochanteric femoral fractures

Introduction and Objective. Hip fractures represent one of the most challenging injuries in orthopaedic practice due to the associated morbidity, mortality and the financial burden they impose on the health care systems. By many still considered as the gold standard in the management of intertrochanteric fractures, the Dynamic Hip Screw utilizes controlled collapse during weight bearing to stabilize the fracture. Despite being a highly successful device, mechanical failure rate is not uncommon. The most accepted intraoperative indicator for lag screw failure is the tip apex distance (TAD), yet lateral femoral wall thickness (LWT) is another evolving parameter for detecting the potential for lateral wall fracture with subsequent medialization and implant failure. The aim of this study is to determine the mean and cut off levels for LWT that warrant lateral wall fracture and the implications of that on implant failure, revision rates and implant choice. Materials and Methods. This prospective cohort study included 42 patients with a mean age of 70.43y with intertrochanteric hip fractures treated with DHS fixation by the same consultant surgeon from April 2019 to December 2019. The study sample was calculated based on a confidence level of 90% and margin of error of 5%. Fracture types included in the study are 31A1 and 31A2 based on the AO/OTA classification system. LWT was assessed in all patients preoperatively using Surgimap (Nemaris, NY, USA) software. Patients were divided into two groups according to the post-operative integrity of the lateral femoral wall, where group (A) sustained a lateral femoral wall fracture intraoperatively or within 12 months after the index procedure, while in group (B) the lateral femoral wall remained intact. All patients were regularly followed up radiologically and clinically per the Harris Hip Score (HHS) for a period of 12 months. Results. At 12 months five patients (12%) suffered a postoperative lateral wall fracture, while in 37 patients (88%) the lateral femoral wall remained intact. The mean preoperative LWT of patients with a postoperative lateral wall fracture was 18.04 mm (SD ± 1.58) compared to 26.22mm (SD ± 5.93) in the group without a lateral wall fracture. All patients with post-operative lateral femoral wall fracture belong to 31A2 group, while 78.4% of the patients that did not develop post-operative lateral femoral wall fracture belong to 31A1 group. Eighty percent of patients in group (A) experienced shortening, collapse, shaft medialization and varus deformity. The mean Harris hip score of group (A) was 39.60 at 3 months and 65.67 at 6 months postoperatively, while that of group (B) was 80.75 and 90.65 at 3 and 6 months respectively, denoting a statistically significant difference (P<0.001). Treatment failure meriting a revision surgery was 40 % in group (A) and 8% in group (B) denoting a statistically significant difference (p<0.001). The cut-off point of LWT below which there is a high chance of post-operative lateral wall fracture when fixed with DHS is 19.6mm. This was shown on the receiver operating curve (ROC) by plotting the sensitivity against the 100 % specificity with a set 95% confidence interval 0.721 – 0.954. When lateral wall thickness was at 19.6 mm, the sensitivity was 100% and specificity was 81.8%. The area under the curve (AUC) was 0.838, which was statistically significant (P = 0.015). Conclusions. Preoperative measurement of LWT in elderly patients with intertrochanteric hip fractures is decisive. The cut off point for postoperative lateral wall fracture according to our study is 19.6 mm; hence, intramedullary fixation has to be considered in this situation

The spiral blade modification of the Dynamic Hip Screw (DHS) was designed for superior biomechanical fixation in the osteoporotic femoral head. Our objective was to compare clinical outcomes and in particular the incidence of loss of fixation.

In a series of 197 consecutive patients over the age of 50 years treated with DHS-blades (blades) and 242 patients treated with conventional DHS (screw) for AO/OTA 31.A1 or A2 intertrochanteric fractures were identified from a prospectively compiled database in a level 1 trauma centre. Using propensity score matching, two groups comprising 177 matched patients were compiled and radiological and clinical outcomes compared. In each group there were 66 males and 111 females. Mean age was 83.6 (54 to 100) for the conventional DHS group and 83.8 (52 to 101) for the blade group.

Loss of fixation occurred in two blades and 13 DHSs. None of the blades had observable migration while nine DHSs had gross migration within the femoral head before the fracture healed. There were two versus four implant cut-outs respectively and one side plate pull-out in the DHS group. There was no significant difference in mortality and eventual walking ability between the groups. Multiple logistic regression suggested that poor reduction (odds ratio (OR) 11.49, 95% confidence intervals (CI) 1.45 to 90.9, p = 0.021) and fixation by DHS (OR 15.85, 95%CI 2.50 to 100.3, p = 0.003) were independent predictors of loss of fixation.

The spiral blade design may decrease the risk of implant migration in the femoral head but does not reduce the incidence of cut-out and reoperation. Reduction of the fracture is of paramount importance since poor reduction was an independent predictor for loss of fixation regardless of the implant being used.

Cite this article: Bone Joint J 2015;97-B:398–404.

Although the importance of lateral femoral wall integrity is increasingly being recognised in the treatment of intertrochanteric fracture, little attention has been put on the development of a secondary post-operative fracture of the lateral wall. Patients with post-operative fractures of the lateral wall were reported to have high rates of re-operation and complication. To date, no predictors of post-operative lateral wall fracture have been reported. In this study, we investigated the reliability of lateral wall thickness as a predictor of lateral wall fracture after dynamic hip screw (DHS) implantation. A total of 208 patients with AO/OTA 31-A1 and -A2 classified intertrochanteric fractures who received internal fixation with a DHS between January 2003 and May 2012 were reviewed. There were 103 men and 150 women with a mean age at operation of 78 years (33 to 94). The mean follow-up was 23 months (6 to 83). The right side was affected in 97 patients and the left side in 111. Clinical information including age, gender, side, fracture classification, tip–apex distance, follow-up time, lateral wall thickness and outcome were recorded and used in the statistical analysis. Fracture classification and lateral wall thickness significantly contributed to post-operative lateral wall fracture (both p < 0.001). The lateral wall thickness threshold value for risk of developing a secondary lateral wall fracture was found to be 20.5 mm. To our knowledge, this is the first study to investigate the risk factors of post-operative lateral wall fracture in intertrochanteric fracture. We found that lateral wall thickness was a reliable predictor of post-operative lateral wall fracture and conclude that intertrochanteric fractures with a lateral wall thickness < 20.5 mm should not be treated with DHS alone. Cite this article: Bone Joint J 2013;95-B:1134–8

Introduction: The use of intramedullary nailing (IMHS) has increased at the expense of the dynamic hip screw (DHS), although the outcome is not different in the studies of pertrochanteric fractures (PTF), known as AO/OTA type 31A1-2 fractures with a preoperative intact lateral femoral wall. We therefore investigated the two implants in the subgroup of PTF with a fractured greater trochanter. Materials and Methods: Six hundred thirty-five consecutive patients with PTF fixated by a short IMHS or by a DHS mounted on a four hole lateral plate were prospectively included between 2002 and 2008. The fractures were preoperatively classified according to AO/OTA classification system, including status of the greater and lesser trochanter. The integrity of the lateral femoral wall, fracture reduction and implant positioning were assessed postoperatively. Reoperations due to technical failures were recorded for one year. Results: Among the 311 patients sustaining a PTF with a fractured greater trochanter, 4% (6/158) operated with an IMHS were reoperated compared to 14% (22/153) with a DHS (p=0.001). Multivariate logistic regression analysis combining demographic and biomechanical parameters showed the IMHS to have a lower rate of reoperation (p=0.002). During the operative procedure, the lateral femoral wall was fractured in 6% (9/158) of patients, in which an IMHS was performed versus 28% (42/153) operated with a DHS (p< 0.001). Among the DHS, a fractured lateral femoral wall was confirmed to be a predictor of a reoperation (31% (13/42) of patients with a fractured lateral femoral wall versus 8% (9/111) with an intact lateral femoral wall, p< 0.001). As in other studies, the different reoperation rate would have been overseen in the main group of AO/ OTA type 31A1-2 PTF fractures (4% (6/164) IMHS versus 6% (30/471) DHS, p=0.196). Conclusion: The IMHS seems to have a lower reoperation rate than the DHS in the subgroup of PTF with a fractured greater trochanter. In contrast to the DHS, the IMHS presumably keeps the integrity of the lateral femoral wall. In future studies, PTF should be divided into subgroups

The Pipino prosthesis was introduced as an alternative to hip resurfacing because of its bone preserving capability. Preserving the femoral neck to a greater extent saves valuable bonestock for possible revision procedures. The stem (proximal 2/3) and acetabular cup are hydroxyapatite coated. Bearings were all either ceramic or metal on polyethylene. All procedures were performed or directly supervised by the senior author. Patients in the cohort were assessed pre-operatively, in the short term and the medium term using the Harris Hip Score(HHS). Hip radiographs were performed at medium term follow-up to assess for radiological signs of aseptic loosening. The study is based on a cohort of 70 patients, 34 male and 36 female with mean age of 52 (range 13-71). Followed up over a mean period of 43 months (range 17-60). 70 patients were contacted and 64 patients were reviewed. Four patients were lost to follow-up. Indications for surgery were Osteoarthritis (56); Rheumatoid arthritis (8); AVN (3); SUFE (2); Perthes (2); DDH (1); Psoriatic Arthropathy (1). The cohort’s preoperative HHS showed a mean 50.1 (range 25-88). This increased to a mean of 95.9 (range 55-100) in the short term review period, during the medium term review the mean 93.6 (range 63-100). With 82% of patients in the excellent group and 88% good to excellent group. At the final review there was one case of aseptic loosening (Cup) which required revision surgery. There were 2 dislocations and one intraoperative lateral femoral wall fracture and no cases of superficial or deep infection. In conclusion we believe that the Pipino collum femo-ris preserving total hip arthroplasty has excellent short and medium term results