Total Hip Arthroplasty With Trochanteric Ostectomy for Patients With Angular Deformity of the Proximal Femur

BackgroundTotal hip arthroplasty (THA) of patients with a proximal femoral deformity is technically demanding. This deformity poses the risk of femoral fracture or perforation; stem malposition; and failed stem fixation. To insert a femoral stem in neutral position with a good fit, we removed the greater trochanter in case of a varus deformity, and the lesser trochanter in case of valgus deformity, while performing THA. We aimed to evaluate stem position, implant stability, clinical results, and radiological changes after THAs using this technique.MethodsFifteen patients (17 hips; 11 varus hips and 6 valgus hips) underwent cementless THA using the trochanteric osteotomy technique in one institution. We evaluated procedure-specific complications: intraoperative femoral fracture, stem malposition, weakness of the abductor power and limp. Modified Harris Hip Score, radiological changes, and the stability of stems were assessed at a mean of 7.1 years of follow-up (range 2.0-15.5).ResultsFemoral fracture occurred during the insertion of the stem in 4 hips. All stems were aligned in neutral position. At the latest follow-up, the mean power of the abductor was 4.3 (range 3-5). Eleven patients had slight limp and 4 patients had moderate limp. All stems had bone-ingrown stability and no stem was revised. The mean modified Harris Hip Score improved from 50 points at the preoperative evaluation to 81 points at the final follow-up.ConclusionThe trochanteric excision enabled neutral insertion of cementless stem in patients with varus/valgus deformity of the proximal femur, and THA using this technique rendered favorable results.     

Effectiveness of controlled telescoping system for lateral hip pain caused by sliding of blade following intramedullary nailing of trochanteric fracture

IntroductionThe purpose of this study was to demonstrate the effectiveness of controlled telescoping system for lateral hip pain caused by sliding of the blade following intramedullary nailing of trochanteric fractures.Materials and methodsA retrospective cohort study was performed to compare the controlled telescoping system (Compression Hip Nail; CHN) with the conventional sliding system (Proximal Femoral Nail Antirotation; PFNA) for trochanteric fractures. 74 cases in the PFNA group and 77 cases in the CHN group were included from two university hospitals in this study. All patients had a minimum of 12-month follow up period. Lateral hip pain was evaluated and operation time and blood loss during the surgery were measured. The fracture classification was evaluated. The quality of postoperative reduction and other complications after surgery were also evaluated and tip-apex distance (TAD), telescoping and lateral protrusion of the blade and lag screw were measured.ResultsThe mean age was 78.5 years in the PFNA group and 74.7 years in the CHN group (p = 0.25). The mean telescoping was 19.2 mm in the PFNA group and 10.7 mm in the CHN group (p < 0.001). The mean length of lateral protrusion was 10.5 mm in the PFNA group and 2.5 mm in the CHN group (p < 0.001). Twenty-eight patients in the PFNA group complained of lateral hip pain, whereas 12 patients in the CHN group did (p = 0.002). These four variables showed statistically significant differences between the PFNA and CHN groups (p < 0.05). The length of lateral protrusion was the only variable significantly related to lateral hip pain through multivariate logistic regression analysis (p = 0.045).ConclusionsThe degree of lateral protrusion was mainly related to lateral hip pain. Therefore, controlled telescoping would help to decrease lateral hip pain by decreasing the lateral protrusion beyond the lateral femoral cortex.     

Femoral intertrochanteric nail (fitn): a new short version design with an anterior curvature and a geometric match study using post-operative radiographs

ObjectiveFemoral intertrochanteric fractures are usually fixed with short, straight cephalomedullary nails. However, mismatches between the nail and the femur frequently occur, such as tip impingement and tail protrusion. The authors designed a new type of short femoral intertrochanteric nail (fitn) with an anterior curvature (length = 19.5 cm, r = 120 cm) and herein report the geometric match study for the first of 50 cases.MethodsA prospective case series of 50 geriatric patients suffering from unstable intertrochanteric fractures (AO/OTA 31 A2/3) were treated. There were 15 males and 35 females, with an average age of 82.3 years. Post-operatively, the nail entry point position in the sagittal greater trochanter (in three categories, anterior, central and posterior), the nail-tip position in the medullary canal (in 5-grade scale) and the nail-tail level to the greater trochanter (in 3-grade scale) were measured using X-ray films.ResultsFor the nail entry point measurement, 5 cases were anterior (10%), 38 cases were central (76%), and 7 cases were posterior (14%). For the distal nail-tip position, 32 cases (64%) were located along the central canal axis, 13 cases (26%) were located anteriorly but did not contact the anterior inner cortex, 2 cases (4%) showed less than one-third anterior cortex thickness contact, and 3 cases (6%) were located posteriorly with no contact. For the proximal nail-tail level, there were no protrusions over the greater trochanter in 15 cases (30%), protrusion of less than 5 mm in 29 cases (58%), and protrusion of more than 5 mm in 6 cases (12%). The fitness was very high, as 96% cases showed no tip-cortex contact, and 88% cases showed less than 5 mm proximal tail protrusion.ConclusionThe newly designed femoral intertrochanteric nail has a good geometric match with the femur medullary canal and the proximal length in the Chinese population.     

Subsidence of collarless uncemented femoral stems in total hips replacements performed for trauma

IntroductionCollarless, uncemented, femoral stems give excellent results in elective hip replacements but few studies look at outcomes in trauma patients. The presence of osteoporosis and subsequent widened femoral canal may compromise the mechanical stability of uncemented femoral stems resulting in early subsidence. The aim of this study was to assess whether early subsidence occurred when collarless uncemented stems were used to treat trauma patients.Materials and methodsPost-operative radiographs of 46 patients, mean age 71, who underwent an uncemented, collarless, total hip replacement for trauma, were reviewed. The difference in distance from the calcar to the prosthesis tip between the immediate post operative radiograph and the subsequent follow-up radiograph was calculated and adjusted for magnification. The same procedure was performed on 36 age-matched patients, who underwent elective hip replacements for osteoarthritis. Hospital notes were reviewed to assess for complications and DEXA scans reviewed for trauma patients where available.ResultsThe mean femoral stem subsidence was significantly greater in the fracture cohort than in elective patients (p = 0.001) with mean subsidence of 4.27 mm (range 0.02–22.05 mm) and 1.57 mm (range 0–5.5 mm), respectively. In the fracture cohort there were 4 revisions within 6 months of surgery, 1 for infection and 3 for femoral stem subsidence leading to dislocation. There were no revisions in the elective cohort.Discussion and conclusionsThis study showed that collarless uncemented stems subsided significantly more when performed for fractures and had a high early revision rate. We recommend that uncemented collarless should not be used in trauma patients requiring total hip replacement.     

A biomechanical study comparing proximal femur nail and proximal femur locking compression plate in fixation of reverse oblique proximal femur fractures

BackgroundThe reverse oblique trochanteric fractures are common fractures and its treatment poses a challenge. The purpose of this study was to compare the biomechanical parameters of the construct using proximal femoral nail (PFN) and proximal femoral locking compression plates (PFLCP) in these fractures using cadaveric specimens.Materials and MethodsTwenty freshly harvested cadaveric femoral specimens were randomly assigned to two groups after measuring bone mineral density, ten of which were implanted with PFN and the other ten with PFLCP. The constructs were made unstable to simulate reverse oblique trochanteric fracture (AO type 31A3.3) by removing a standard size posteromedial wedge. These constructs were tested in a computer controlled cyclic compressive loading with 200 kg at a frequency of 1 cycle/s (1 Hz) and test was observed for 50,000 cycles or until implant failure, whichever occurred earlier. Peak displacements were measured and analysis was done to determine axial stiffness and subsidence in axial loading.ResultsAll the specimens in PFN group completed 50,000 cycles and in PFLCP group, seven specimens completed 50,000 cycles. Average subsidence in PFN group was 1.24 ± 0.22 mm and in PFLCP group was 1.48 ± 0.38 mm. The average stiffness of PFN group (72.6 ± 6.8 N/mm) was significantly higher than of PFLCP group (62.4 ± 4.9 N/mm) (P = 0.04). The average number of cycles sustained by PFLCP was 46634 and for PFN group was 50,000 (P = 0.06).ConclusionThe PFN is biomechanically superior to PFLCP in terms of axial stiffness, subsidence and number of specimens failed for the fixation of reverse oblique trochanteric fractures of femur.     

The impact of antegrade intramedullary nailing start site using the SIGN nail in proximal femoral fractures: A prospective cohort study

IntroductionIn many low and middle-income countries (LMICs) SIGN nail is commonly used for antegrade femoral intramedullary (IM) nailing, using a start site either at the tip of the greater trochanter or piriformis fossa. While a correct start site is considered an essential technical step; few studies have evaluated the impact of using an erroneous start site. This is particularly relevant in settings with limited access to fluoroscopy to aid in creating a nail entry point. The purpose of this study was to evaluate the impact of antegrade SIGN IM nailing start site on radiographic alignment and health-related quality of life.MethodsIn this prospective cohort study, adult patients with proximal femur fractures (OTA 32, subtrochanteric zone) treated with antegrade IM SIGN nail at Muhimbili Orthopaedic Institute (MOI), Dar es Salaam, Tanzania were enrolled. Start site was determined on the immediate postoperative X-ray and was graded on a continuous scale based on distance of the IM nail center from the greater trochanteric tip. The primary outcome measurement was coronal alignment on the post-operative x-ray. The secondary outcomes were reoperation rates, RUST scores and EQ5D scores at one year follow-up.ResultsSeventy-nine patients were enrolled. 50 of them (63.3%) had complete data at 1 year and were included in the final data analysis. Of the fifty patients, nine (18%) had IM nails placed laterally, 26 (52%) medially and 15 (30%) directly over the tip of the greater trochanter. Compared to a start site at the tip or medial to the greater trochanter, a lateral start site was 9 times more likely to result in a varus malalignment (95% CI: 1.42–57.70, p = 0.021).ConclusionsLateral start site was associated with varus malalignment. Although lateral start site was not significantly associated with reoperation, varus deformity was associated with higher reoperation rates. Surgeons should consider avoiding a start site lateral to the tip of the greater trochanter or allow the nail to rotate to avoid malalignment when using the SIGN nail for proximal femur fractures.     

Intraoperative lateral wall fractures during Dynamic Hip Screw fixation for intertrochanteric fractures-Incidence,causative factors and clinical outcome

IntroductionThe intact lateral wall plays a key role in stabilization of trochanteric fracture. Hence extreme precaution should be taken to prevent lateral wall damage during DHS fixation. Present study is aimed at evaluating the determinants of lateral wall fracture and its effect on outcome in intertrochanteric fracture femur treated with DHS.Material and methodsThis is a prospective study involving intertrochanteric fractures treated with DHS fixation from July 2013 to June 2014. Out of 135 patients 49(36.3%) had stable fractures and 86(63.7%) unstable fractures. Cortical thickness index (CTI) was measured to evaluate osteoporosis. Lateral wall thickness in anteroposterior radiograph was also measured.All patients underwent 135 ° DHS fixation.Postoperative x-rays are assessed for implant position, intactness of the lateral wall, tip apex distance (TAD) and medialization. Functional outcome was measured at the end of fracture union by modified Harris hip score and Parkers mobility score. Clinical information including age, gender, fracture classification, TAD, lateral wall thickness and functional outcome of the patients were subjected to statistical analysis.Results34 (19.5%) patients had lateral wall fractures. Medialization was found in 22 out of these 34 (64.7%) patients. The mean preoperative lateral wall thickness of these patients is 19.2 mm, compared with 26.8 mm in patients with intact lateral wall (p < 0.001). The mean values of CTI and TAD are comparable in both the groups. In patients with intact lateral wall, mean Harris hip score is 73.1 compared to 65.5 in lateral wall fracture group (p < 0.001). Preinjury mobility status was achieved in 70.2% of intact lateral wall patients, whereas only 32.3% (11) achieved that in lateral wall fracture group. Threshold for lateral wall thickness that could predict lateral wall fracture was found to be 21 mm with 95% sensitivity and 88.2% specificity.ConclusionLateral wall fractures during DHS fixation are not uncommon and osteoporosis has no bearing on its occurrence. It alone can lead to poor radiological and functional outcome independent of TAD. Lateral wall thickness is a reliable predictor of intra operative lateral wall fracture during DHS fixation and nailing is a good option especially when lateral wall thickness is <21 mm.     

Plate fixation in periprosthetic femur fractures Vancouver type B1—Trochanteric hook plate or subtrochanterical bicortical locking?

IntroductionProximal plate fixation in periprosthetic femur fractures can be improved by plate anchorage in the greater trochanter (lateral tension band principle) or bicortical locking screw placement beside the prosthesis stem in an embracement configuration. Both concepts were compared in a biomechanical test using a femoral hook plate (hook) or a locking attachment plate (LAP).MethodsAfter bone mineral density (BMD) measurement in the greater trochanter, six pairs of fresh frozen human femora were assigned to two groups and instrumented with cemented hip endoprostheses. A transverse osteotomy was set distal to the tip of the prosthesis, simulating a Vancouver B1 fracture. Each pair was instrumented using a plate tensioner with either hook or LAP construct. Cyclic testing (2 Hz) with physiologic profile and monotonically increasing load was performed until catastrophic failure. Plate stiffness was compared in a four-point-bending-test. Paired student’s-t-test was used for statistical evaluation (p < 0.05).ResultsMean BMD was 250 mgHA/ccm ± 47. The hook construct exhibited a significantly (p = 0.015) lower number of cycles and load to failure (26′177 cycles ± 2777; 3′118N ± 778) correlating significantly with BMD (R² = 0.83; p = 0.04) compared to the LAP construct (37′423 cycles ± 5′299; 4′242N ± 1′030) (R² = 0.71;p = 0.11). BMD was a significant covariate (p = 0.01). Plate stiffness was in a comparable range (hook Plate 468 N/mm ± 7; LCP 445 N/mm ± 6).ConclusionSubtrochanterically placed LAP provides an increased fixation strength under repetitive loading compared to hook plate fixation in the greater trochanter. Trochanteric fixation is highly BMD dependent and may be restricted to major greater trochanteric involvement requiring stabilization.     

Trochanteric entry femoral nails yield better femoral version and lower revision rates—A large cohort multivariate regression analysis

IntroductionIntramedullary nailing (IMN) has become the standard of care for the treatment of most femoral shaft fractures. Different IMN options include trochanteric and piriformis entry as well as retrograde nails, which may result in varying degrees of femoral rotation. The objective of this study was to analyze postoperative femoral version between three types of nails and to delineate any significant differences in femoral version (DFV) and revision rates.Materials & methodsOver a 10-year period, 417 patients underwent IMN of a diaphyseal femur fracture (AO/OTA 32A-C). Of these patients, 316 met inclusion criteria and obtained postoperative computed tomography (CT) scanograms to calculate femoral version and were thus included in the study. In this study, our main outcome measure was the difference in femoral version (DFV) between the uninjured limb and the injured limb. The effect of the following variables on DFV and revision rates were determined via univariate, multivariate, and ordinal regression analyses: gender, age, BMI, ethnicity, mechanism of injury, operative side, open fracture, and table type/position. Statistical significance was set at p < 0.05.ResultsA total of 316 patients were included. Piriformis entry nails made up the majority (n = 141), followed by retrograde (n = 108), then trochanteric entry nails (n = 67). Univariate regression analysis revealed that a lower BMI was significantly associated with a lower DFV (p = 0.006). Controlling for possible covariables, multivariate analysis yielded a significantly lower DFV for trochanteric entry nails than piriformis or retrograde nails (7.9 ± 6.10 vs. 9.5 ± 7.4 vs. 9.4 ± 7.8°, p < 0.05). Using revision as an endpoint, trochanteric entry nails also had a significantly lower revision rate, even when controlling for all other variables (p < 0.05).ConclusionComparative, objective comparisons between DFV between different nails based on entry point revealed that trochanteric nails had a significantly lower DFV and a lower revision rate, even after regression analysis. However, this is not to state that the other nail types exhibited abnormal DFV. Translation to the clinical impact of a few degrees of DFV is also unknown. Future studies to more in-depth study the intricacies of femoral version may lead to improved technology in addition to potentially improved clinical outcomes.     

Femoral nerve block in a representative sample of elderly people with hip fracture: A randomised controlled trial

IntroductionThe number of elderly people with hip fracture and dementia is increasing, and many of these patients suffer from pain. Opioids are difficult to adjust and side effects are common, especially with increased age and among patients with dementia. Preoperative femoral nerve block is an alternative pain treatment.AimTo investigate whether preoperative femoral nerve block reduced acute pain and opioid use after hip fracture among elderly patients, including those with dementia.Patients and methodsIn this randomised controlled trial involving patients aged ≥70 years with hip fracture (trochanteric and cervical), including those with dementia, we compared femoral nerve block with conventional pain management, with opioid use if required. The primary outcome was preoperative pain, measured at five timepoints using a visual analogue scale (VAS). Preoperative opioid consumption was also registered.ResultsThe study sample comprised 266 patients admitted consecutively to the Orthopaedic Ward. The mean age was 84.1 (±6.9) years, 64% of participants were women, 44% lived in residential care facilities, and 120 (45.1%) had dementia diagnoses. Patients receiving femoral nerve block had significantly lower self-rated pain scores from baseline to 12 h after admission than did controls. Self-rated and proxy VAS pain scores decreased significantly in these patients from baseline to 12 h compared with controls (p < 0.001 and p = 0.003, respectively). Patients receiving femoral nerve block required less opioids than did controls, overall (2.3 ± 4.0 vs. 5.7 ± 5.2 mg, p < 0.001) and in the subgroup with dementia (2.1 ± 3.3 vs. 5.8 ± 5.0 mg, p < 0.001).ConclusionPatients with hip fracture, including those with dementia, who received femoral nerve block had lower pain scores and required less opioids before surgery compared with those receiving conventional pain management. Femoral nerve block seems to be a feasible pain treatment for elderly people, including those with dementia.     

Assessment of trochanteric osteotomy fragment union after acetabular fracture surgery

BackgroundTrochanteric osteotomies are performed in conjunction with standard approaches to improve surgical exposure during open reduction and internal fixation (ORIF) of acetabular fractures. The literature on total hip arthroplasty reports nonunion rates as high as 30% associated with trochanteric osteotomies; however, few data exist regarding the outcomes of trochanteric osteotomies for acetabular fracture surgery. Our hypotheses were 1) patients receiving trochanteric osteotomies during ORIF of acetabular fractures have a low rate of nonunion of the osteotomy fragment, and 2) hip abduction precautions are not necessary with digastric type osteotomies.Patients and methodsA retrospective review was conducted to identify patients with acetabular fractures between July 2002 and June 2010 (n = 734 fractures) who required trochanteric osteotomies (n = 64, 9% of fractures). Forty-seven met inclusion criteria of adequate follow-up (>56 days). No excluded patient experienced a complication. Fractures were classified using the Letournel-Judet classification system.ResultsOnly seven (20%) of 35 patients who received digastric osteotomies had hip abduction precautions applied during the postoperative period. All study patients were shown to have radiographic union at the trochanteric osteotomy site (100% union rate, n = 47). Hip abduction precautions intended to protect the osteotomy site and reduce the risk of nonunion and fixation failure were infrequently applied to patients with digastric osteotomies (20%) in this cohort. Multiple protective factors against nonunion were present in this study population compared with previous arthroplasty studies from other institutions.ConclusionsTrochanteric osteotomies are not associated with a significant nonunion rate, and digastric osteotomies might be safely managed without hip abduction precautions.     

Augmentation by cerclage wire improves fixation of vertical shear femoral neck fractures—A biomechanical analysis

BackgroundFemoral neck fractures in young individuals are typically vertical shear fractures. These injuries are difficult to stabilize due to a significant varus displacement force across the hip with weight bearing. The purpose of this study was to evaluate the biomechanical stability offered by the addition of an augmented wire to conventional inverted triangle triple screw fixation for stabilizing vertical shear femoral neck fracture.MethodsSixteen medium 4th-generation synthetic composite femurs (Sawbones Pacific Research Laboratories, Vashon, WA) were divided into two groups. Vertical osteotomy was performed to mimic Pauwels III femoral neck fracture. Group A (n = 8) was fixed with three parallel 6.5-mm cannulated screws (Stryker) with washer in inverted triangle configuration. In group B (n = 8), all the screws were set using methods identical to group A, with the addition of the cerclage wire. Both groups were tested with nondestructive axial compression test at 7 and 25 ° of valgus stress, respectively. Then axial cyclic loading test with 1000 N was applied for 1000 cycles, and interfragmentary displacement was measured with Fastrak magnetic tracking system (Polhemus, Colchester, VT, USA). Finally, destructive axial compression test was conducted at 7°of valgus stress.ResultsAxial stiffness showed that group B had a 66% increase (879 N/mm vs. 1461 N/mm, P < 0.01) at 7° valgus and a 46% increase (1611 N/mm vs. 2349 N/mm, P < 0.01) at 25° valgus in comparison with group A. Interfragmentary fracture displacement after cyclic loading was significantly less for group B compared with group A (0.34 vs 0.13 mm, P = 0.0016). For axial failure load, there was 42% increase in group B compared with group A (2602 N/mm vs. 3686 N/mm, P = 0.0023).ConclusionsOur study demonstrates that the addition of a cerclage wire to inverted triangle triple screws provides substantial improvement in mechanical performance regarding fixation of vertically oriented femoral neck fractures when compared with the conventional construct. Our study provides support from a mechanical analysis perspective for the reported clinical usefulness of the cerclage wire.     

Does restoration of leg length and femoral offset play a role in functional outcome one year after hip hemiarthroplasty?

BackgroundThe objective of this study was to evaluate the correlation between specific joint biomechanical parameters and 1 year functional outcome scores in elderly patients receiving hemiarthroplasty in the setting of intracapsular hip fractures.MethodsThis is a retrospective, institutional registry based study. 168 hip hemarthroplasties were captured from October 2013 to June 2015. Patients were excluded based on contralateral hip surgery, perioperative complications or inadequate radiographs. 84 patients were alive at one year follow up. We compared mobility and pain scores to radiographically determined variations of leg lengths and femoral offset. We also compared the performance of fellowship trained arthroplasty surgeons to their non-fellowship trained counterparts.ResultsThe operated leg was a mean of 1.12 ± 6.8 mm longer than the contralateral. leg length discrepancy (LLD) was less than 10 mm in 72 patients. Mean difference in offset between limbs was 0.25 ± 3.3 mm. The difference was within 5 mm in 79 patients (94%). We found no statistically significant correlation between mobility or pain scores and variations in leg length or offset. We found significantly better performance of the arthroplasty surgeons in restoring leg length but no difference in offset reconstruction or functional benefit for the patient.ConclusionsOur study was unable to demonstrate a significant relationship between leg length or femoral offset restoration and the patient’s ultimate functional recovery. Arthroplasty surgeons performed better in restoring leg length, but no associated functional advantage was seen.     

Radiological assessment of the safe zone for medial minimally invasive plate osteosynthesis in the distal femur with computed tomography angiography

IntroductionSurgical treatment options for distal femur fractures include intramedullary nailing or plating using a lateral or lateral parapatellar approach. However, medial plating is required for additional stability in some fractures such as severely comminuted fractures and periprosthetic fractures, and in those for which use of a lateral plate or nail is not appropriate. This study aimed to explore the safe zone for medial minimally invasive plate osteosynthesis of the distal femur with computed tomography angiography.Material and methodsIn a series of 30 patients, the region of interest between the lesser trochanter (LT) to the adductor tubercle (AT) was divided into six levels (I to VI), and the distance from the femur to the femoral artery (FA) was measured. At each level, the medial half of the femur was divided into eight sections that were assigned ‘A to H’ from anteromedial to posteromedial, and the position of the FA and the deep femoral artery (DFA) was recorded.ResultsThe average length from the LT to AT was 295.0 mm. The average distance to FA was 38.0 mm, 29.9 mm, 26.9 mm, 27.0 mm, 21.8 mm, and 12.2 mm from level I to VI, respectively. The FA was positioned posteromedially below level IV and positioned at C–H below level II, which was out of the anterior aspect of the femur. The DFA was in the same location as the FA between levels II and III.ConclusionThe anteromedial aspect of the distal half of the femur is the safe zone, and a long plate can be positioned safely in this zone at the anterior aspect up to the level of 8 cm below the LT.     

A mathematical simulation of the tip-apex distance and the calcar-referenced tip-apex distance for intertrochanteric fractures reduced with lag screws

BackgroundAs a predictor of the risk of lag screw cutout, it was recommended that keeping tip-apex distance (TAD) < 25 mm and placing the screw centrally or inferiorly, but positioning the lag screw too inferiorly in the head would produce TAD > 25 mm. We aim to simulate various positions of the lag screw in the femoral head and identify whether 25 mm is a suitable cut-off value that favours all sizes of femoral heads with intertrochanteric fractures of the hip.MethodsUsing a general mathematical software, the positions of the screw tip points were simulated. The virtual anterior–posterior and lateral views were then visualised, and the locus of the screw tips was projected into a Cartesian coordinate system according to the TAD and calcar-referenced tip-apex distance (CalTAD) formulas. Each original virtual anterior–posterior and lateral image was zoomed and compiled to match a calculated average image. The screw tip points were recorded, traced and compiled into volumes which could be used to visualise the screw's movements and positioning within the femoral head. The extracted volumes were calculated when 10 mm < TAD < 25 mm and 10 mm < CalTAD < 25 mm, and the region where these two volumes overlapped was also calculated. Suitable positions for the screw tip were then assessed.ResultsFor the TAD calculation, the shape of the traced screw tip points had a pancake-like appearance, while the CalTAD plot produced a teardrop-shaped region. The volume ratios of TAD, CalTAD and overlapping region relative to the femoral head volume were respectively 3.51 ± 1.30%, 5.19 ± 1.62% and 2.64 ± 1.32%. The volumes of the traced TAD, CalTAD and overlapping regions increased slower than the volume of an idealised sphere.ConclusionPositioning the lag screw should address geometrical effects of both tip-apex distance and femoral head size, with an emphasis on measuring the position of the screw tip for the suitable zone by volume ratio. The previous 25 mm TAD cut-off value should be adjusted according to the individual femoral head size.     

When does intraoperative 3D-imaging play a role in transpedicular C2 screw placement?

IntroductionThe stabilization of an atlantoaxial (C1-C2) instability is demanding due to a complex atlantoaxial anatomy with proximity to the spinal cord, a variable run of the vertebral artery (VA) and narrow C2 pedicles. We perfomed the Goel & Harms fusion in combination with an intraoperative 3D imaging to ensure correct screw placement in the C2 pedicle. We hypothesized, that narrow C2 pedicles lead to a higher malposition rate of screws by perforation of the pedicle wall. The purpose of this study was to describe a certain pedicle size, under which the perforation rate rises.Patients and methodsIn this retrospective study, all patients (n = 30) were operated in the Goel & Harms technique. The isthmus height and pedicle diameter of C2 were measured. The achieved screw position in C2 was evaluated according to Gertzbein & Robbin classification (GRGr).ResultsA statistically significant correlation was found between the pedicles size (isthmus height/pedicle diameter) and the achieved GRGr for the right (p = 0.002/p = 0.03) and left side (p = 0.018/p = 0.008). The ROC analysis yielded a Cut Off value for the pedicle size to distinguish between an intact or perforated pedicle wall (GRGr 1 or ≥2). The Cut-Off value was identified for the isthmus height (right 6.1 mm, left 5.4 mm) and for the pedicle diameter (6.6 mm both sides).ConclusionThe hypothesis, that narrow pedicles lead to a higher perforation rate of the pedicle wall, can be accepted. Pedicles of <6.6 mm turned out to be a risk factor for a perforation of the pedicle wall (GRGr 2 or higher). Intraoperative 3D imaging is a feasible tool to confirm optimal screw position, which becomes even more important in cases with thin pedicles. The rising risk of VA injury in these cases support the additional use of navigation.     

Pre-operative digital templating in cemented hip hemiarthroplasty for neck of femur fractures

Pre-operative digital templating allows the surgeon to foresee any anatomical anomalies which may lead to intra-operative problems, and anticipate appropriate instruments and implants required during surgery. Although its role is well-established in successful elective total hip arthroplasty, little work has been done on its use in hip hemiarthroplasty in neck of femur fractures. We describe our initial experience of digital templating in 40 consecutive patients who have undergone cemented hip hemiarthroplasty, assessing templating accuracy between templated implant sizes to actual implant sizes. 81% of implanted heads were templated to within two head sizes, and 89% of implanted stems were templated to within two sizes. Although there was a moderately strong correlation of 0.52 between templated and actual head sizes, this correlation was not demonstrated in femoral stem sizes. Mean leg length discrepancy was −2.5 mm (S.D. 8.5), and the mean difference in femoral offset between the operated and non-operated hip was −1 mm (S.D. 4.4). Digital templating is a useful adjunct to the surgeon in pre-operative planning of hip hemiarthroplasty in the restoration of leg length and femoral offset. However, its accuracy is inferior to that of elective total hip arthroplasty.     

Internal fixation versus conservative treatment for elderly patients with a trochanteric hip fracture in conjunction with post-stroke hemiplegia

ObjectiveTo retrospectively evaluated Gamma nail internal fixation in the treatment of elderly patients with post-stroke hemiplegia experiencing trochanteric hip fracture.MethodsThe patients were obtained consecutively from January 2005 to December 2010 with inclusion criteria. The total number was 138 and allocated to two groups: treated with the Gamma nail (n = 72,group A) and continuous skin traction (n = 66,group B). Preoperative variables including patient age, gender, duration of cerebrovascular accident, duration of hypertension, ASA risk score, Harris hip score and fracture type were recorded and compared. After treatment, time of patients activity on the bed, ambulation time, Harris hip score, mortality, complications were recorded and used to compare the outcomes.Results(1) Follow-up was undertaken from 3 to 10 years, with an average of 5.8 years. (2) No statistical difference in preoperative variables was found between the 2 groups. (3) two groups had statistical significance (P = 0.000) in the time of patients activity on the bed and ambulation time and group A can activities on the bed and ambulates earlier. (4) There were significant differences between 2 groups in Harris hip score at 1 and 3 years and group A was significantly higher than group B. (5) there were statistically significant differences in mortality of 3 years, 5 years and 10 years and the group B was significantly higher than the group A. (6) There was a statistical significance in complications between 2 groups and group B was higher than group A. Major complications in group A were pain, lag screw cut out, implant infection and distal femoral fractures caused by fall after the surgery.ConclusionOn elderly patients with trochanteric hip fracture on the hemiplegic lower side, Gamma nail internal fixation treatment can achieve better effect, patients can be early activity, fewer complications, and less mortality.     

Is a Total Hip Arthroplasty Stem in Varus a Risk Factor of Long-Term Mechanical Complication?

BackgroundThe impact of implanting cementless femoral stems in varus alignment on long-term mechanical complications remains poorly defined in the literature. The aim of our study was to compare survivorship and functional and radiographic outcomes of stems in varus alignment to those in neutral alignment with and average follow-up of 10 years.MethodsThis single-center, multisurgeon, retrospective case-control study compared a group of 105 total hip arthroplasty (THA) patients who had varus stem alignment (Varus Stem) to a matching group of 105 THA patients who had neutral stem alignment, operated on between January 2007 and December 2012. The primary outcome measure was implant survival. Secondary outcomes included functional (Harris Hip Score, Postel Merle d'Aubigné Score, thigh pain, dislocation and hip range of motion) and radiographic outcomes (radiolucency, osseointegration, heterotopic ossification, subsidence, and stress shielding).ResultsThere was no significant difference in implant survival between the 2 groups with 95.7% (±2.46) in the Varus Stem group versus 97.7% (±1.64) in the Neutral Stem group (P = .41) after an average follow-up of 10 years. There was no significant difference in clinical and radiographic outcomes between groups.ConclusionCementless femoral stems in varus alignment were not the cause of mechanical complications with an average follow-up of 10 years. The comparison between groups in terms of implant survival, functional, and radiographic outcomes does not show any significant differences. Positioning a femoral stem in varus alignment may be an alternative for surgeons wishing to restore preoperative offset and to ensure satisfactory hip stability.     

Fixation of displaced femoral neck fractures in young adults: Fixed-angle devices or Pauwel screws?

BackgroundWe sought to compare the incidence of complications after fixation of displaced femoral neck fractures in young adults treated with fixed-angle devices versus multiple cancellous screws and a trochanteric lag screw (Pauwel screw).MethodsWe conducted a retrospective cohort study at a level I trauma centre. Sixty-two skeletally mature patients (age range, 16–60 years) with displaced femoral neck fractures were included in the study. Forty-seven were treated with a fixed-angle device (sliding hip plate with screw or helical blade) and 15 with multiple cancellous screws placed in a Pauwel configuration. The main outcome measure was postoperative complication of osteonecrosis or nonunion treated with a surgical procedure.ResultsSignificantly fewer failures occurred in the fixed-angle group (21%) than in the screws group (60%) (p = 0.008). Osteonecrosis was rare in the fixed-angle group, occurring in 2% of cases versus 33% of cases in the screws group (p = 0.002). Consistent with previous studies, good to excellent reductions were associated with a failure rate of 25% and fair to poor reductions were associated with a failure rate of 55% (p = 0.07). The best-case scenario of a good to excellent reduction stabilised with a fixed-angle device yielded a success rate of 85%.ConclusionIn young patients with displaced high-energy femoral neck fractures, fixed-angle devices resulted in fewer treatment failures than did Pauwel screws.