Objectives. The paradoxical migration of the femoral neck element (FNE) superomedially against gravity, with respect to the intramedullary component of the cephalomedullary device, is a poorly understood phenomenon increasingly seen in the management of pertrochanteric hip fractures with the intramedullary nail. The aim of this study was to investigate the role of bidirectional loading on the medial migration phenomenon, based on unique wear patterns seen on scanning electron microscopy of retrieved implants suggestive of FNE toggling. Methods. A total of 18 synthetic femurs (Sawbones, Vashon Island, Washington) with comminuted pertrochanteric fractures were divided into three groups (n = 6 per group). Fracture fixation was performed using the Proximal Femoral Nail Antirotation (PFNA) implant (Synthes, Oberdorf, Switzerland; n = 6). Group 1 was subjected to unidirectional compression loading (600 N), with an elastomer (70A durometer) replacing loose fracture fragments to simulate surrounding soft-tissue tensioning. Group 2 was subjected to bidirectional loading (600 N compression loading, 120 N tensile loading), also with the elastomer replacing loose fracture fragments. Group 3 was subjected to bidirectional loading (600 N compression loading, 120 N tensile loading) without the elastomer. All constructs were tested at 2 Hz for 5000 cycles or until cut-out occurred. The medial migration distance (MMD) was recorded at the end of the testing cycles. Results. The MMDs for Groups 1, 2, and 3 were 1.02 mm, 6.27 mm, and 5.44 mm respectively, with reliable reproduction of medial migration seen in all groups. Bidirectional loading groups showed significantly higher MMDs compared with the unidirectional loading group (p < 0.01). Conclusion. Our results demonstrate significant contributions of bidirectional cyclic loading to the medial migration phenomenon in cephalomedullary nail fixation of pertrochanteric hip fractures. Cite this article: G. W. Law, Y. R. Wong, A. K-S. Yew, A. C. T. Choh, J. S. B. Koh, T. S. Howe. Medial migration in cephalomedullary nail fixation of pertrochanteric hip fractures: A biomechanical analysis using a novel bidirectional cyclic loading model. Bone Joint Res 2019;8:313–322. DOI: 10.1302/2046-3758.87.BJR-2018-0271.R1

Controversy exists whether to treat unstable pertrochanteric hip fractures with either intra-medullary or extra-medullary devices. A prospective randomised control trial was performed to compare the outcome of unstable pertrochanteric hip fractures stabilised with either a sliding hip screw or long Gamma Nail. The hypothesis was that there is no difference in outcome between the two modes of treatment. Over a four year period, 210 patients presenting with an unstable pertrochanteric hip fracture (AO/OTA 31 A2) were recruited into the study. Eligible patients were randomised on admission to either long Gamma Nail or sliding hip screw. Follow-up was arranged for three, six, and twelve months. Primary outcome measures were implant failure or ‘cut-out’. Secondary measures included mortality, length of hospital stay, transfusion rate, change in mobility and residence, and EuroQol outcome score. Five patients required revision surgery for implant cut-out (2.5%), of which three were long Gamma Nails and two were sliding hip screws (no significant difference). There were no incidences of implant failure or deep infection. Tip apex distance was found to correlate with implant cut-out. There was no statistically significant difference in either the EuroQol outcome scores or mortality rates between the two groups when corrected for mini mental score. There was no difference in transfusion rates, length of hospital stay, and change in mobility or residence. There was a clear cost difference between the implants. The sliding hip screw remains the gold standard in the treatment of unstable pertrochanteric fractures of the proximal femur

Controversy exists whether to treat unstable pertrochanteric hip fractures with either intramedullary or extramedullary devices. A prospective randomised control trial was performed to compare the outcome of unstable pertrochanteric hip fractures stabilised with either a sliding hip screw (SHS) or Long Gamma Nail (LGN). The hypothesis was that there is no difference in outcome between the two modes of treatment. Over a four year period, 210 patients presenting with an unstable pertrochanteric hip fracture (AO/OTA 31 A2.1/A2.2/A2.3) were recruited into the study. Eligible patients were randomised on admission to either LGN or SHS. Follow-up was arranged for three, six, and twelve months. Primary outcome measures were implant failure and implant ‘cut-out’. Secondary measures included mortality, length of hospital stay, and EuroQol outcome score. Five patients required revision surgery for implant cutout, of which three were LGNs and two were SHSs (no significant difference). There was a significant correlation between tip apex distance and the need for revision surgery. There were no incidences of implant failure or deep infection. Mortality rates between the two groups were similar when corrected for mini mental score. There was no difference between the two groups with respect to tip apex distance, hospital length of stay, blood transfusion requirement, and EuroQol outcome score. The sliding hip screw remains the gold standard in the treatment of unstable pertrochanteric fractures of the proximal femur

Purpose: The purpose of this study is to provide an additional tool to determine the stability of AO 31A2 pertrochanteric hip fractures. This study is based on the lateral hip radiograph, which has been ignored in the current debate over stability. Method: One-hundred and thirty-one patients were identified through medical records with a diagnosis of pertrochanteric hip fracture treated with sliding hip screw from 2003–2008. Thirty-nine patients had AO 31A2 hip fractures, cross-table lateral injury films, intra-operative fluoroscopy and follow-up films. Only 23 had follow-up films beyond discharge. The landmarks of interest were angulation and translation between the femoral shaft and neck on cross-table lateral injury films. The neck was defined in three ways: the anterior cortex, two key points in the anterior cortex and the neck bisector. The most consistent measure was used. Translation of the neck was measured as a percentage of the shaft diameter. Measurements were taken by two blinded researchers with different levels of experience. Film sequence was randomized. The primary outcome was shortening of the sliding hip screw greater than one centimetre. This is the exact midpoint between 0.61 centimetres, which is not associated with reduced patient mobility, and 1.34 centimetres which is associated with reduced patient mobility, as described by Muller-Farber. The hip screw was measured from its tip to the point it enters the barrel. The diameter of the hip screw was known and provided scale. The measurement from intra-operative fluoroscopy films with the leg in traction, represented zero shortening. Results: The average follow up was 190 days. Using the neck bisector to measure angulation was most consistent (95% of measurements available versus 89% and 88% with other methods). More than 30° angulation and/or 30% translation on the lateral predicted shortening greater than one centimetre with 91% specificity and 33% sensitivity. The average shortening in this group was 1.6 centimeters, which is greater than shortening associated with reduced patient mobility (1.34 centimeters). Agreement between two researchers was 91% and considered “substantial” (kappa 0.71) as per Landis and Koch criteria. Conclusion: This is a highly specific and reproducible tool to detect a subset of AO 31A2 hip fractures which acquire unwanted collapse if treated with a sliding hip screw. This information adds clarity to the debate over stability of some AO 31A2 fracture cases, at no additional cost for the surgeon and facility. The “30/30 rule” (30° angulation and 30% translation) should not be used in isolation due to low sensitivity. Other factors may affect shortening, such as the degree of comminution and the antero-posterior film should still be considered

Aim: To compare two implants, the Gamma Nail and the ACE Trochanteric Nail in the treatment of pertrochanteric femoral fractures. Patients and methods: Sixty patients were randomized on admission to two treatment groups. Thirty patients were treated with the Gamma nail implants , and thirty had intramedullary fixation with ACE Trochanteric NailI . The average age of these patients was 79 years. 22 patients were men and 38 women. 11 fractures were stable and 49 unstable. Patients were followed for 1 year and had a regular clinical and radiological review at 1, 3 and 6 months postoperatively. Operation time, intra-operative blood loss and blood transfusion and complications were recorded. The mobility score was used to assess the preinjury and postoperative mobility status. All the patients were operated within 24 hours after their accident and 39 of them within the first 6 hours. Results: There were no complications during the surgery. All the patients were mobilized the first 24 hours post operatively irrespectively of the fracture’s type, and weight bearing was permitted as tolerated. The mean follow up time was 8 months (range 6 to 12 months). 3 patients were lost at the follow up and 2 died. Union of the fracture was achieved in all 55 patients. There was no statistically significant difference between the two groups with regard to intraoperative blood loss and the duration of the surgery. There was no mechanical failure of the implants despite the early patients mobilization. All the patients achieved mobility status similar to the preoperative at the latest follow up. Conclusions: Based on our study, intramedullary nailing of pertrochanteric hip fractures represents a reliable method of treatment. We did not observe any differences in the two patient groups concerning the operation time, the intraoperative blood loss, the postoperative complications and the patients functional status at the latest follow up

Aims

There are concerns regarding nail/medullary canal mismatch and initial stability after cephalomedullary nailing in unstable pertrochanteric fractures. This study aimed to investigate the effect of an additional anteroposterior blocking screw on fixation stability in unstable pertrochanteric fracture models with a nail/medullary canal mismatch after short cephalomedullary nail (CMN) fixation.

Objectives

The Sliding Hip Screw (SHS) is commonly used to treat trochanteric hip fractures. Fixation failure is a devastating complication requiring complex revision surgery. One mode of fixation failure is lag screw cut-out which is greatest in unstable fracture patterns and when the tip-apex distance of the lag screw is > 25 mm. The X-Bolt Dynamic Hip Plating System (X-Bolt Orthopaedics, Dublin, Ireland) is a new device which aims to reduce this risk of cut-out. However, some surgeons have reported difficulty minimising the tip-apex distance with subsequent concerns that this may lead to an increased risk of cut-out.

Objectives

Intramedullary fixation is considered the most stable treatment for pertrochanteric fractures of the proximal femur and cut-out is one of the most frequent mechanical complications. In order to determine the role of clinical variables and radiological parameters in predicting the risk of this complication, we analysed the data pertaining to a group of patients recruited over the course of six years.

This retrospective cohort study was conducted to investigate whether operative treatment of patients with a pertrochanteric femoral fracture outside working hours is associated with an increased risk of complications and higher mortality. During the study period 165 patients were operated on outside working hours and 123 were operated on during working hours (08.00 to 17.00). There was no difference in the rate of early complications (outside working hours 33% versus working hours 33%, p = 0.91) or total complications during follow-up (outside working hours 40% versus working hours 41%, p = 0.91). Both in-hospital mortality (outside working hours 12% versus working hours 11%, p = 0.97) and mortality after one year (outside working hours 29% versus working hours 27%, p = 0.67) were comparable. Adjustment for possible confounders by multivariate logistic regression analysis revealed no increased risk of complications when patients were operated on outside working hours.

On the basis of these data, there is no medical reason to postpone operative reduction and fixation in patients with a proximal femoral fracture until working hours.