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

Aims. Cephalomedullary nails (CMNs) are commonly used for the treatment of intertrochanteric hip fractures. Total hip arthroplasty (THA) may be used as a salvage procedure when fixation fails in these patients. The aim of this study was to analyze the complications of THA following failed intertrochanteric hip fracture fixation using a CMN. Patients and Methods. Patients who underwent THA were identified from the 5% subset of Medicare Parts A/B between 2002 and 2015. A subgroup involving those with an intertrochanteric fracture that was treated using a CMN during the previous five years was identified and compared with the remaining patients who underwent THA. The length of stay (LOS) was compared using both univariate and multivariate analysis. The incidence of infection, dislocation, revision, and re-admission was compared between the two groups, using multivariate analysis adjusted for demographic, hospital, and clinical factors. Results. The Medicare data yielded 56 522 patients who underwent primary THA, of whom 369 had previously been treated with a CMN. The percentage of THAs that were undertaken between 2002 and 2005 in patients who had previously been treated with a CMN (0.346%) more than doubled between 2012 and 2015 (0.781%). The CMN group tended to be older and female, and to have a higher Charlson Comorbidity Index and lower socioeconomic status. The mean LOS was 1.5 days longer (5.3 vs 3.8) in the CMN group (p < 0.0001). The incidence of complications was significantly higher in the CMN group compared with the non-CMN group: infection (6.2% vs 2.6%), dislocation (8.1% vs 4.5%), revision (8.4% vs 4.3%), revision for infection (1.1% vs 0.37%), and revision for dislocation (2.2% vs 0.6%). Conclusion. The incidence of conversion to THA following failed intertrochanteric hip fracture fixation using a CMN continues to increase. This occurs in elderly patients with increased comorbidities. There is a significantly increased risk of infection, dislocation, and LOS in these patients. Patients with failed intertrochanteric hip fracture fixation using a CMN who require THA should be made aware of the increased risk of complications, and steps need to be taken to reduce this risk. Cite this article: Bone Joint J 2019;101-B(6 Supple B):91–96

Introduction. The vast majority of intertrochanteric fractures treated with cephalomedullary nails (CMN) will heal. Occasionally even though bony union occurs excessive lag screw sliding can cause persistent pain and soft tissue irritation and return to surgery for hardware removal. The purpose of this study was to evaluate if fracture stability, lag screw tip-apex distance (TAD), and quality of reduction have any impact excessive lag screw sliding and potential cutout. Methods. As part of our level one trauma center's institutional hip fracture registry, a retrospective analysis identified 199 intertrochanteric fractures fixed with CMN between 2009 and 2015 with follow up to union or a minimum of three months. The mean follow-up was 22 months (3 to 94 months). Mean patient age was 75 years (50 to 97 years) and 72% were women. Postoperative radiographs were used to measure the TAD, quality of reduction, neck-shaft angle (NSA), and lateral lag screw prominence. Follow-up radiographs were reviewed to assess fracture union, translation, and progression of lateral lag screw prominence. Complications and reoperations were recorded. Results. The average lag screw sliding was 5±5 mm. Excessive lag screw sliding (defined as > 10 mm; one standard deviation above the mean) was present in 12% of patients. Lag screw sliding was more common in unstable fracture patterns (21% vs. 5%, p<0.01) and patients with calcar fracture gapping > 4 mm (26% vs. 4%, p<0.01). Lag screw sliding was not associated with age (p=0.9), sex (p=0.4), TAD (p=0.3), implant (p=0.8), distal interlocking screws (p=0.3), or NSA (p=0.2). There were seven (3%) patients with prominent lag screws that required removal. These patients experience more lag screw sliding than those that did not require removal (9 mm vs. 5 mm, p<0.01). The average TAD was 17±5 mm. 15 (7%) of patients had TAD of 25 mm or more. There were 2 cutouts (1%). The average TAD was larger in the cutout group (26 vs. 17 mm, p<0.01). Conclusion. In this series, the incidence of cutout was low and associated with a larger tip-apex distance. Excessive lag screw sliding was associated with unstable fracture patterns, calcar fracture gapping, and more reoperations for symptomatic hardware. Careful attention to calcar fracture reduction may minimize excessive lag screw sliding

Intertrochanteric fractures are common, accounting for nearly 30% of all fracture related admissions. Some have suggested that these fractures should be treated in community hospitals so as not to tax the resources of Level One trauma centers. Since many factors predictive of fixation failure are related to technical aspects of the surgery, the purpose of this study was to compare radiographic parameters after fixation comparing trauma fellowship trained surgeons to non-fellowship trained community surgeons to see if these fractures can be treated successfully in either setting. Using our hospital system's trauma database, we identified 100 consecutive patients treated with cephalomedullary nails by traumatologists, and 100 consecutive patients treated by community surgeons. Quality of reduction, neck shaft angle (NSA), tip-to apex distance (TAD) were compared. The mean TAD for the trauma group was 10mm compared to 21mm for the community group (p<0.001). The mean postoperative NSA for the trauma group was 133 degrees compared to 127 degrees for the community group (p<0.001). The mean difference in the NSA of the fractured side compared to the normal hip was 2.5 degrees of valgus in the trauma group compared to 5 degrees of varus for the community group (p<0.001). There were 93 good reductions in the trauma group compared to 19 in the community group (p<0.001). There were no poor reductions in the trauma group and 49 poor reductions in the community group (p<0.001). Fellowship trained traumatologists achieved significantly more accurate reductions and implant placement during cephalomedullary nailing of intertrochanteric hip fractures

Introduction. Cephalomedullary nails (CMN) are commonly used for the treatment of intertrochanteric (IT) hip fractures. Total hip arthroplasty (THA) is commonly used as a salvage procedure for failed IT hip fractures that progress to post-traumatic arthritis. This study analyzed the complications of THA following treatment of failed IT hip fractures with cephalomedullary nails. Methods. Patients who had a primary THA were identified from the 5% subset of Medicare Parts A/B from 2002–2015. A subgroup with previous CMN for IT hip fracture within the previous 5 years was identified and compared to the remaining THA patients without prior CMN. Length of stay (LOS) was compared using both univariate and multivariate analysis. Infection, dislocation, revision, and readmission were compared between those with and without prior CMN, using multivariate analysis (adjusted for demographic, hospital, and clinical factors). Results. 5% subset of the Medicare data yielded 56,522 primary THA, with 369 treated with prior CMN. The percentage of primary THA from 2002–2005 with prior cephalomedullary nails (0.346%) more than doubled in 2012–2015 (0.781%). The prior CMN group tended to be older, female, higher CCI, and lower socioeconomic status. Mean LOS was 1.5 days longer (5.3 vs 3.8) in the prior CMN group (p<0.0001). The percentage of postoperative complications was significantly higher in the prior CMN group compared to non-CMN cohort: infection (6.2% vs 2.6%), dislocation (8.1% vs 4.5%), revision (8.4% vs 4.3%), revision for infection (1.1% vs 0.37%), and revision for dislocation (2.2% vs 0.6%). Discussion. Conversion from failed IT hip fractures with cephalomedullary nails to total hip arthroplasty continues to increase. These cases occur in elderly patients with increased comorbidities. There is a significantly increased risk of infection, dislocation and LOS in the CMN group. Patients with failed IT hip fractures undergoing THA should be made aware of the increased complication risk and further steps need to be undertaken to diminish the elevated risk

The purpose of this study was to identify factors that predict implant cut-out after cephalomedullary nailing of intertrochanteric and subtrochanteric hip fractures, and to test the significance of calcar referenced tip-apex distance (CalTAD) as a predictor for cut-out. We retrospectively reviewed 170 consecutive fractures that had undergone cephalomedullary nailing. Of these, 77 met the inclusion criteria of a non-pathological fracture with a minimum of 80 days radiological follow-up (mean 408 days; 81 days to 4.9 years). The overall cut-out rate was 13% (10/77). The significant parameters in the univariate analysis were tip-apex distance (TAD) (p <  0.001), CalTAD (p = 0.001), cervical angle difference (p = 0.004), and lag screw placement in the anteroposterior (AP) view (Parker’s ratio index) (p = 0.003). Non-significant parameters were age (p = 0.325), gender (p = 1.000), fracture side (p = 0.507), fracture type (AO classification) (p = 0.381), Singh Osteoporosis Index (p = 0.575), lag screw placement in the lateral view (p = 0.123), and reduction quality (modified Baumgaertner’s method) (p = 0.575). In the multivariate analysis, CalTAD was the only significant measurement (p = 0.001). CalTAD had almost perfect inter-observer reliability (interclass correlation coefficient (ICC) 0.901). Our data provide the first reported clinical evidence that CalTAD is a predictor of cut-out. The finding of CalTAD as the only significant parameter in the multivariate analysis, along with the univariate significance of Parker’s ratio index in the AP view, suggest that inferior placement of the lag screw is preferable to reduce the rate of cut-out. Cite this article: Bone Joint J 2014; 96-B:1029–34

Subtrochanteric femoral fractures are a subset of hip fractures generally treated with cephalomedullary nail fixation\[1\]. Single lag screw devices are most commonly-used, but integrated dual screw constructs have become increasingly popular\[2,3\]. The aim of this study was to compare outcomes of fixation of subtrochanteric femoral fractures using a single lag screw (Gamma3 nail, GN) with a dual screw device (InterTAN nail, IN). The primary outcome was mechanical failure, defined as lag screw cut-out, back-out, nail breakage or peri-implant fracture. Consecutive adult patients (18yrs) with subtrochanteric femoral fracture treated in a single centre were retrospectively identified using electronic records. Patients that underwent surgical fixation using either a long GN (2010–2017) or IN (2017–2022) were included. Medical records and radiographs were reviewed to identify complications of fixation. Cox regression analysis was used to determine the risk of mechanical failure and secondary outcomes by implant design. Multivariable regression models were used to identify predictors of mechanical failure. The study included 622 patients, 354 in the GN group (median age 82yrs, 72% female) and 268 in the IN group (median age 82yrs, 69% female). The risk of any mechanical failure was increased two-fold in the GN group (HR 2.44 \[95%CI 1.13 to 5.26\]; _p=0.024_). Mechanical failure comprising screw cut-out (_p=0.032_), back-out (_p=0.032_) and nail breakage (_p=0.26_) was only observed in the GN group. Technical predictors of failure included varus >5° for cut-out (OR 19.98 \[2.06 to 193.88\]; _p=0.01_), TAD;25mm for back-out (8.96 \[1.36 to 58.86\]; p=0.022) and shortening 1cm for peri-implant fracture (7.81 \[2.92 to 20.91\]; _p=<0.001_). Our results demonstrate that an intercalated screw construct is associated with a lower risk of mechanical failure compared with the a single lag screw device. Intercalated screw designs may reduce the risk of mechanical complications for patients with subtrochanteric femoral fractures

Objectives

Fractures of the proximal femur are a common clinical problem, and a number of orthopaedic devices are available for the treatment of such fractures. The objective of this study was to assess the rotational stability, a common failure predictor, of three different rotational control design philosophies: a screw, a helical blade and a deployable crucifix.

Most hip fractures treated with modern internal fixation techniques will heal. However, failures occasionally occur and require revision procedures. Salvage strategies employed during revision are based on whether the fixation failure occurs in the femoral neck, or in the intertrochanteric region. Patient age and remaining bone stock also influence decision making. For fractures in young patients, efforts are generally focused on preserving the native femoral head via osteotomies and repeat internal fixation. For failures in older patients, some kind of hip replacement is usually selected. Disuse osteopenia, deformity, bone loss, and stress-risers from previous internal fixation devices all pose technical challenges to successful reconstruction. Attention to detail is important in order to minimise complications. In the majority of cases, good outcomes have been reported for the various salvage strategies.

Cite this article: Bone Joint J 2013;95-B, Supple A:7–10.

Many tumors metastasise to bone, therefore, pathologic fracture and impending pathologic fractures are common reasons for orthopedic consultation. Having effective treatment strategies is important to avoid complications, and relieve pain and preserve function. Thorough pre-operative evaluation is recommended for medical optimization and to ensure that the lesion is in fact a metastasis and not a primary bone malignancy. For impending fractures, various scoring systems have been proposed to determine the risk of fracture, and therefore the need for prophylactic stabilisation. Lower score lesions can often be treated with radiation, while more problematic lesions may require internal fixation. Intramedullary fixation is generally preferred due to favorable biomechanics. Arthroplasty may be required for lesions with massive bony destruction where internal fixation attempts are likely to fail. Radiation may also be useful postoperatively to minimise construct failure due to tumor progression.