Lag Screw Research Articles

A novel intramedullary nail design of intertrochanteric fracture fixation improved by proximal femoral nail antirotation

A proper and reliable fracture fixation is important for fracture healing. The proximal femoral intramedullary nail (IN), such as proximal femoral nail anti-rotation (PFNA) or Gamma nail, is widely used for intertrochanteric fracture fixation. However, it still suffers considerable stress concentrations, especially at the junction between the nail and the blade or lag screw. In this study, we propose a novel intramedullary nail design to enhance the intramedullary nail integrity by introducing a bolt screw to form a stable triangular structure composed of the nail, the lag screw, and the bolt screw (PFTN, Proximal femoral triangle nail). Systematic finite element numerical simulations were carried out to compare the biomechanical performances of PFTN and PFNA under both static and dynamic loads during the postures of ascending and descending stairs. The simulation results highlight the advantages of the proposed PFTN design with lower stresses, less stress concentration, and higher structure stability.

Letter to the Editor: Anterior Malreduction is Associated With Lag Screw Cutout After Internal Fixation of Intertrochanteric Fractures.

Letter to the Editor: Anterior Malreduction is Associated With Lag Screw Cutout After Internal Fixation of Intertrochanteric Fractures.

Biomechanics of internal fixation in Hoffa fractures – A comparison of four different constructs

ObjectiveCompare the biomechanical effectiveness of four different bone-implant constructs in preventing fracture displacement under axial loading. MethodsTwenty artificial femora had a standardized coronally oriented fracture of the lateral femoral condyle, representing a Hoffa fracture classified as a Letenneur type I. Four different fixation constructs were applied to the synthetic bones for biomechanical testing. The constructs consisted of a posterolateral (PL) buttressing locking plate in conjunction with two cannulated lag screws inserted from posterior to anterior (PA) – Group 1; Two cannulated screws inserted from anterior to posterior (AP) without plating– Group 2; A posterolateral (PL) buttressing locking plate in isolation – Group 3; and a combination of two lag screws from anterior to posterior (AP) in addition to a horizontal one-third tubular locking plate – Group 4. An axial load was applied to the fracture site with a constant displacement speed of 20 mm/min, and the test was interrupted when a secondary displacement was detected determining a fixation failure. We recorded the maximum applied force and the maximum fracture displacement values. ResultsGroup 1 demonstrated the highest overall bone-implant axial stiffness with the lowest secondary displacement under loading. Groups 3 and 4 showed equivalent mechanical behavior. Group 2 presented the lowest mechanical stiffness to axial loading. The combination of the one-third tubular locking plate with anterior-to-posterior lag screws (Group 4) resulted in 302 % increase in fixation stiffness when compared to anterior-to-posterior lag screws only (Group 2). ConclusionsThis study confirms the mechanical superiority of having a plate applied parallel to the main fracture plane in the setting of coronally oriented femoral condyle fractures. The addition of a horizontal plate, perpendicular to the main fracture plane, significantly increased the resistance to shearing forces at the fracture site when compared to constructs adopting just cannulated screws. Level of evidenceBiomechanical study

Effect of Wood Densification and GFRP Reinforcement on the Embedment Strength of Poplar CLT

Embedment strength is an important factor in the design and performance of connections in timber structures. This study assesses the embedment strength of lag screws in three-ply cross-laminated timber (CLT) composed of densified poplar wood with densification ratios of 25% and 50%, under both longitudinal (L) and transverse (T) loading conditions. The embedment strength was thereafter compared with that of CLT reinforced with glass-fiber-reinforced polymer (GFRP). The experimental data was compared with results obtained using different models for calculating embedment strength. The findings indicated that the embedment strength of CLT specimens made of densified wood and GFRP was significantly greater than that of control specimens. CLT samples loaded in the L direction showed higher embedment strength compared to those in the T direction. In addition, 50% densification had the best performance, followed by 25% densification and GFRP reinforcement. Modelling using the NDS formula yielded the highest accuracy (mean absolute percentage error = 10.31%), followed by the Ubel and Blub (MAPE = 21%), Kennedy (MAPE = 28.86%), CSA (MAPE = 32.68%), and Dong (MAPE = 40.07%) equations. Overall, densification can be considered as an alternative to GFRP reinforcement in order to increase the embedment strength in CLT.

Characteristics and Treatment Strategies for Basicervical and Transcervical Shear Fractures of the Femoral Neck.

This study aimed to define basicervical and transcervical shear fractures using area classification and to determine the optimal osteosynthesis implants for them. The clinical outcomes of 1042 proximal femur fractures were investigated. A model of the proximal femur of a healthy adult was created from computed tomography images, and basicervical and transcervical shear fractures were established in the model. Osteosynthesis models were created using a short femoral nail with a single lag screw or two lag screws and a long femoral nail with a single lag screw or two lag screws. The minimum principal strains of the fracture surfaces were compared when the maximum loads during walking were applied to these models using finite element analysis software. Basicervical fractures accounted for 0.96% of all proximal femur fractures, 67% of which were treated with osteosynthesis; the failure rate was 0%. Transcervical shear fractures accounted for 9.6% of all proximal femur fractures, 24% of which were treated with osteosynthesis; the failure rate was 13%. Finite element analysis showed that transcervical shear fracture has high instability. To perform osteosynthesis, multiple screw insertions into the femoral head and careful postoperative management are required; joint replacement should be considered to achieve early mobility.

Mechanical outcomes of the TFNA, InterTAN and IMHS intramedullary nailing systems for the fixation of proximal femur fractures

IntroductionHip fractures have become a major public health priority due to their increasing incidence. Intramedullary (IM) nailing has gained popularity as a surgical technique for managing these fractures. However, comparative studies with extramedullary devices indicate potentially increased mechanical complications associated with IM nailing. Specifically, there have been recent reports of early implant fracture associated with the TFNA system. This study compares the rate of mechanical complications between 3 implants. Secondarily, we analysed the factors associated with implant fracture and all other mechanical complications. MethodsThis retrospective study included 803 IM nails performed between 2008–2021 for the fixation of proximal femur fractures at a level 1 trauma centre. We recorded patient demographics, AO fracture classification, implant specification and intra-operative parameters such as tip-apex distance, Cleveland index, reduction quality, presence of medial calcar integrity, neck-shaft angle. The outcomes analysed included implant fracture, lag screw cut-out, >10 mm backing out, autodynamisation, periprosthetic fracture, non-union at 6 months and time to revision surgery. ResultsThe overall implant fracture rate was 3.1 % (25/803), with no statistically significant difference between the three devices (p = 0.51). The TFNA group included 183 patients with a median follow-up of 1.6 years. The TFNA fracture rate was 2.2 % (4/183) which occurred at 207 +/- 16.66 days post-operatively. The rate of all mechanical complications was 4.9 % in the TFNA group, 12.9 % in the InterTAN group and 17 % in the IMHS group. Non-union (p < 0.001) and increasing lag screw length (p < 0.02) were identified as risk factors for implant fracture and other mechanical complications. The reverse oblique fracture pattern (AO 31 A3.1) was associated with mechanical complications only (p < 0.01). The cumulative survival rates without revision for the TFNA, InterTAN, IMHS groups were 97.8 %, 95.5 % and 87.9 % respectively at 2.5 years. DiscussionThe rates of implant fracture were comparable between the three nailing systems. The TFNA provides effective fixation for proximal femur fractures using a traditional screw without cement augmentation. The TFNA was associated with an overall reduction in mechanical complications compared to the InterTAN and IMHS. Previously reported mechanical complications associated with IM Nails may relate to older device designs.

Syndesmosis dislocation and ankle ligament stress in the posterior malleolus fracture fixated – “in vitro analysis”

PurposeThe objectives of this study were to compare syndesmosis dislocation and ankle ligament stress after the fixation of the posterior malleolus fracture (PMF) with four different techniques by Finite Element Analysis (FEM). MethodsFour internal fixation techniques used for fixation of PMF were assessed by FEM: posterior one-third tubular 3.5 mm buttress plate (PP) with one screw (PP 1 screw), PP with two screws (PP 2 screws), two cannulated 3.5 mm lag screws in the anteroposterior (AP) direction (AP lag screws), and two posteroanterior (PA) cannulated 3.5 mm lag screws (PA lag screws). PMF with 30% fragment size was simulated through computational processing reconstructed from computed tomography (CT). The simulated loads of 700 N and 1200 N were applied to the proximal tibial end. The FEM evaluated the syndesmosis dislocation (mm) and stress values of the posterior tibiofibular ligament (PTFL) (in Kpa) and deltoid ligament (in Kpa) in the four mentioned subgroups. ResultsWe found that with a load of 700 N, syndesmosis dislocation varied from 6.5 to 7.9 mm, being the lowest and greatest for PA lag screw and PP 1 screw, respectively. In all groups was observed a greater dislocation in the syndesmosis at 1200 N of load. We observed that the stress values on the PTFL were lower for AP lag screws and PP 2 screws with 700 N and 1200 N, respectively. For both loads, PP 1 screw presented the greatest stress. Regarding the stress in the deltoid ligament, the AP lag screws presented the lowest stress for 700 N and PP 1 screw for 1200 N. For all fixation techniques, the syndesmosis displacement and ligament stresses were higher when 1200 N were imposed. ConclusionThis study demonstrated that PMF fixed with lag screws presents greater stability in the distal tibiofibular syndesmosis and higher joint loadings promoted greater displacement and ligaments stress, regardless of the fixation technique. Besides, lower stress in the syndesmosis is accompanied by a greater load on the deltoid ligament.

Treatment of intertrochanteric fractures using cephalomedullary nail: One or two cephalic screws?

ObjectivesTo determine the incidence of cut-out, cut-in, cut-through, Z-effect, and reverse Z-effect in two cephalomedullary nail (CMN) systems: one with single cephalic screw fixation and the other with dual-screw fixation using a lag screw and an anti-rotation screw. MethodsA retrospective study from a cohort of patients was conducted between January 2017 and August 2019 in patients with intertrochanteric fractures treated with osteosynthesis using CMN. ResultsOne hundred ninety-six patients with intertrochanteric fractures who met the inclusion criteria were recruited. The median age was 81 years [interquartile range (IQR) 12]. Seventy-six percent had fractures classified as Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen (OTA/AO) 31A2. Twenty-one mechanical complications occurred, 8.7% (17) was cut-out with a single cephalic screw CMN and 2% (4) was Z-effect with a dual-screw CMN non-integrated. The median tip-apex distance (TAD) was 19.4 mm (IQR 10.8) in patients who experienced cut-out and 19 mm (IQR 10) in those who experienced Z-effect. The median time to cut-out occurrence was 39,5 days (IQR 47,5), while the median time to Z-effect was 90 days (IQR 86). ConclusionsThe incidence of osteosynthesis failure using CMN is more frequent in patients treated with a single cephalic screw CMN. Level of EvidenceTherapeutic, Level III

Augmentative lag screws as a treatment for aseptic hypertrophic nonunion after internal fracture fixation

BackgroundHypertrophic nonunion after intramedullary (IM) nailing and plating is Uncommon and the treatment remained controversial. The aim of this study was to show the result of a simple augmentative lag screws technique for vital non-unions after internal fixation Patients and methodsWe retrospectively reviewed the patients with nonunion after internal fixation between January 2016 to August 2022. Patients with unacceptable shortening or deformity were excluded as well as nonunion septic cases. All the patients were followed up for at least 6 months. ResultsSeven patients achieved bony union in a median time of 12 weeks (IRQ 12–16). There was a failure case with persistent non-union and brokerage of the screws. DiscussionVarious techniques have been described to treat non-union after intramedullary nailing or plating. The existing nail is frequently removed, and the non-union site is either re-reamed and re-nailed or fixed with a plate or external fixation devices or rechanged by a nail in the case of plates. In our study of non-union, augmentative lag screws were successfully applied to treat eight patients with aseptic nonunion, resulting in the healing of non-union in all cases except one. ConclusionAugmentative lag screws represent a simple technique for the management of aseptic hypertrophic nonunion after internal fixation with a significantly shorter operating time.

Antegrade posterior column screw fixation for acetabular fractures: It's time to standardize the surgical technique

Antegrade fixation of posterior column fractures of the acetabulum is challenging due to the narrow corridor and risk of screw misplacement. Although both antegrade and retrograde lag screws have been previously described for posterior column fracture fixation, the literature lacks a standardized technique for correct and safe screw placement, especially in an antegrade fashion. This technical note aims to optimize intraoperative images during posterior screw insertion using the antegrade technique, according to predetermined landmarks to save surgical time, decrease radiation exposition, and prevent surgical complications.

Implant-associated fracture of the tibial plateau in cementless medial unicondylar knee prosthesis : Locking plate osteosynthesis

Cementless medial unicondylar knee prostheses with mobile inlays have proved to be successful and are increasingly being used worldwide; however, there is a risk of fracture of the medial tibial plateau in the postoperative healing phase. In most cases we observed split fractures starting from the keel of the implant. These can be treated with a small posteromedial locking plate, whereby the upper screws are inserted through the keel slot and then interlocked. This achieves an optimally strong bond between the implant and the screws and a stable construct. A longitudinal skin incision is made at the level of the keel slot. A radial T‑plate is placed subcutaneously. The plate is fixed with a lag screw in the middle section. The compression usually closes the fracture gap. Then three locking cortical bone screws are inserted through the keel slot in the transverse section of the plate. Distal fixation by locking or standard screws. Immediate pain-adapted partial weight bearing, unrestricted mobility. Healing of the fracture and full weight bearing mostly achieved after 4weeks.

Evaluation of osteosynthesis of miniplate versus lag screw in management of mandibular angle fracture - A comparative study

The aim of the study was to compare lag screw and standard (Champy’s) miniplate fixation in the management of mandibular angle fractures and to analyze advantages and disadvantages of one over the other. A total of 30 patients involving mandibular angle fracture reporting to the Department of Oral, Maxillofacial and Reconstructive Surgery, Bapuji Dental College and Hospital, Davangere, were included in the study. Patients were divided into two groups randomly. The procedure was carried out under general anesthesia. Following strict aseptic precautions, an appropriate intraoral/extra-oral incision was selected; fracture site identified, reduced, and after obtaining satisfactory occlusion, temporary maxillo-mandibular fixation was placed using either Erich’s arch bar or Ivy loop eyelet wiring. Fixation was done using either standard miniplate (Group 1) or lag screw (Group 2). The patients were followed up for a period of 2 months at the interval of 1 week, 2 weeks, 4 weeks, and 8 weeks by a blinded experienced oral surgeon for infection, segmental mobility, postoperative occlusion and radiological evaluation of reduction and fixation. Duration of fixation was found to be less in lag screw group than in miniplate group. Radiological evaluation of reduction and fixation was significant in both the groups. No significant difference was found between both the groups in clinical parameters such as infection, segmental mobility and postoperative occlusion. The clinical outcomes of both the lag screw system and standard miniplate systems in the present study were similar. However, the following advantages with the use of lag screw can be highlighted: Relatively lesser fixation time, Superior fracture fragment stability, fewer complications, Stable occlusion &amp; less hardware, less cost required.

Long Cephalomedullary Nails Can Be a Cheap and Effective Interval Revision Prosthesis in Infected Hip Replacements That Require Proximal Femoral Replacement: A Small Case Series.

Hip prosthetic joint infection management is complex and expensive, especially in severe bone loss.Reducing the price of interval prosthesis when performing staged revision could minimize costs without compromising outcomes. We present 2 similar techniques developed independently that use an antibiotic-coated cephalomedullary nail with a total hip arthroplasty bearing (head and cemented acetabular component) attached to it as an interval proximal femoral replacement prosthesis. Using this technique, the femoral implant cost was reduced up to 10-fold. All patients have recovered well with resolution of infection and functional recovery similar to patients undergoing proximal femoral replacement. In one case, the lag screw (femoral neck) fractured at 5 months prompting the second-stage revision. This complication should be considered when deciding the timing of second-stage revisions in these cases.

Operative Fixation of a Humeral Shaft Periprosthetic Fracture After IlluminOss: A Case Report.

An 82-year-old man sustained a periprosthetic fracture after IlluminOss photodynamic bone stabilization system (PBSS) stabilization for an impending pathologic fracture. Nonoperative management was unsuccessful, and he subsequently underwent operative fixation, which featured lag screw fixation of the spiral distal humeral shaft fracture and osteotomy followed by plate fixation of the pathologic humeral shaft fracture. This is the first article to report this complication with IlluminOss PBSS stabilization and details regarding revision surgery.

Effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeⅡscapular pelvis fracture

To analyze the effect of lag screw and support plate through axillary approach for the treatment of Ideberg typeⅡscapular pelvis fracture. From January 2016 to June 2021, 26 patients with Ideberg typeⅡglenoid fractures were treated with trans-axillary lag screw combined with supporting plate, including 15 males and 11 females. The age ranged from 21 to 75 years, with an average of (43.12±6.56) years old. The Constant-Murley Shoulder joint Scale and University of California at Los Angeles (UCLA) score were used to evaluate the function and clinical efficacy of shoulder joint. All patients were followed up, and the duration ranged from 19 to 42 months, with an average of (30.6±10.5) months. One year after surgery, the Constant-Murley score increased from preoperative 34.9±2.5(ranged, from 28 to 47) to 87.2±6.8(ranged, from 70 to 95). The UCLA score improved from preoperative 17.9±1.7(9 to 25) to 33.1±2.3(29 to 35). Seventeen patients got an excellent result, with 7 good, and 2 fair. None of the patients had infection, screw, and plate loosening, fracture, and other complications after surgery. Two patients had different degrees of Chronic pain in the shoulder during the follow-up period. The treatment of Ideberg typeⅡscapular glenoid fractures through axillary approach with lag screws and supporting steel plates has the advantages of convenient exposure, direct visual restoration of the normal anatomical shape of the scapular glenoid, selection of suitable positions for screw and steel plate placement, achieving better treatment results, and fewer complications. It is an effective and reliable surgical method.

A Good Tip-Apex Distance Does Not Make Up For a Poor Reduction in Intertrochanteric Hip Fractures Treated with an Cephalomedullary Nail: The Utility of the Neck-Shaft Angle in Preventing Fixation Failure.

Determine if any fracture characteristics or radiographic parameters were predictive of fixation failure [FF] within 1 year following cephalomedullary nailing for intertrochanteric fractures. A consecutive series of intertrochanteric hip fracture patients (AO/OTA 31A) treated with a cephalomedullary nail were reviewed. Pre-fixation (neck-shaft angle [NSA], distance from ischial tuberosities to greater and lesser trochanters, integrity of lesser trochanter, and fracture angulation) and post-fixation (post-fixation NSA, posteromedial cortex continuity, lag screw position, tip to apex distance [TAD], and post-fixation angulation and translation) radiographic parameters were measured by blinded independent reviewers. The FF and non-FF groups were statistically compared. Logistic regression was performed to determine radiographic parameter correlates of FF. Of 1249 patients, 23 (1.8%) developed FF within 1 year. The FF patients were younger than their non-FF counterparts (77.2 years vs 81.0 years, p=0.048), however there were no other demographic differences. The FF cohort did not differ in frequency of TAD over 25 mm (4.3% vs 9.6%, p=0.624) and had decreased mean TAD (13.6mm vs 16.3mm, p=0.021) relative to the non-FF cohort. The FF cohort had a higher rate of a post-fixation coronal plane NSA more than 10° different from the contralateral side (delta NSA>10°, 34.8% vs 13.7%, p=0.011) with the majority fixed in relative varus. For every 1° increase in varus compared to the contralateral side the odds of FF increased 7% (OR=1.065, 95%CI[1.005-1.130], p=0.034) on univariate analysis. On univariate logistic regression, patients with an absolute post-fixation NSA of 10° or more of varus compared to contralateral were significantly more likely to have a FF (OR=3.139, 95%CI[1.067-8.332], p=0.026). Despite an acceptable TAD, post-fixation NSA in relative varus as compared to the contralateral side was significantly associated with failure in intertrochanteric hip fractures fixed with a cephalomedullary nail. Prognostic Level III.

Study of anatomical parameters and intraoperative fluoroscopic techniques for transiliac crest anterograde lag screws fixation of the posterior column of the acetabulum

BackgroundCurrently, there is a lack of research investigating the feasibility of employing anterograde lag screw fixation through the iliac crest for minimally invasive percutaneous treatment of the posterior acetabular column, which encompasses retrograde and anterograde screw fixation in posterior acetabular lag screw fixation. And consequently, the purpose of this study was to examine the anatomical parameters of anterograde lag screw fixation of the posterior column of the pelvis through the iliac crest as well as to investigate the intraoperative fluoroscopy technique, to furnish a scientific rationale supporting the practical utilization of this method within clinical settings.MethodsIn this study, pelvic CT data of 60 healthy adults, including 30 males and 30 females, were accumulated. The mimics 21.0 software was developed to reconstruct the three-dimensional pelvis model, simulate the anterograde lag screw fixation of the posterior column of the acetabulum through use of the iliac crest, and precisely identify the insertion point: Utilizing the widest iliac tubercle as the starting point, the insertion point was moved toward the anterior superior iliac spine by 1.0 cm at a time until it reached 4.0 cm. With a total of five insertion points, all oriented toward the lesser sciatic notch, the initial diameter of the virtual screw measured 5.0 mm, and it was progressively enlarged by 1.0 mm increments until reaching a final diameter of 8.0 mm. Besides, the longest lengths of virtual screws with distinct diameters at divergent entry points were measured and compared. At the same time, the intraoperative fluoroscopy technique for optimal access was analyzed.ResultsThe cross-section from the iliac crest to the lesser sciatic notch was irregular, with multiple curved shapes. Furthermore, the diameter of the screw was determined by the anteroposterior radians and width of the iliac crest plate, while the screw length was determined by the curvature of the square body. On the condition that the screw diameter of the D channel (3.0 cm outward from the widest part of the iliac tubercle to the lesser sciatic notch) was 5 mm, 6 mm as well as 7 mm, the longest screw lengths were (145.6 ± 12.8) mm, (143.6 ± 14.4) mm and (139.9 ± 16.6) mm, correspondingly, indicating statistically substantial distinctions from other channels (P < 0.0001). Intraoperative fluoroscopy demonstrated that the C-arm machine was tilted (60.7 ± 2.9) ° to the iliac at the entrance position and perpendicular to the D-channel at the exit position.ConclusionIt is possible to use the new channel to fix the posterior column of the acetabulum with an anterograde lag screw through the iliac crest. In specific, the channel is 3.0 cm outward from the widest part of the iliac tubercle to the lesser sciatic notch. Providing a wide channel, long screw insertion, and high safety, this technique offers a novel approach for minimally invasive treatment of posterior column fractures of the acetabulum.

No effect of hydroxyapatite-coated sliding hip screw threads on screw migration in the femoral head/neck of pertrochanteric fractures: a randomized controlled trial using radiostereometric analysis

IntroductionCut-out is the most frequently reported mechanical failure of internal fixation of pertrochanteric fractures. The purpose of this study was to examine if hydroxyapatite-coated screw thread on a sliding hip screw (SHS) could reduce screw migration within the femoral head in patients with stable pertrochanteric fractures.Materials and methodsIn a double-blinded randomized controlled study, 37 patients at mean age 78 (range 56–96), with pertrochanteric fracture (Evans I, II, IV) received surgery with a SHS with a hydroxyapatite-coated or a non-coated lag screw thread. Radiostereometry and standard radiographs were obtained 1 day, 6 weeks, 3- and 6 months post-operatively to evaluate screw and fracture migration and fracture reposition. The two groups were combined to describe fracture migration.ResultsThere was similar and small screw migration in the femoral head between the two groups at 6 weeks, 3- and 6 months (p > 0.12). Fracture migration occurred predominantly in the first 6 weeks, where fracture impaction was 5.95 mm (CI 95% 2.87 to 9.04) and anterior rotation of the femoral head was -2.94° (CI 95% − 5.22 to − 0.66). Migration of the fracture (total translation) correlated to the post-operative fracture reposition (p = 0.002), but not significantly to screw migration (p = 0.09). Neither screw total translation (rho 0.06, p = 0.79) nor fracture total translation (rho 0.04, p = 0.77) correlated with bone mineral density.ConclusionThere was no clinical benefit of hydroxyapatite coating on lag screw migration in this patient cohort. Migration of the pertrochanteric fractures was higher with poor fracture reposition but fractures generally stabilized after 6 weeks follow-up. The study was registered at ClinicalTrials.gov (NCT05677061).Level of evidence IIPatient-blinded prospective randomized study.Trial registration number The study was registered at ClinicalTrials.gov (NCT05677061).

Anterior Malreduction is Associated With Lag Screw Cutout After Internal Fixation of Intertrochanteric Fractures.

Lag screw cutout is a devastating complication after internal fixation of an intertrochanteric fracture. Although the tip-apex distance (TAD) is known to be associated with this complication, another factor we thought was potentially important-fracture reduction on an oblique lateral view-has not, to our knowledge, been explored. (1) Is a well-reduced fracture position on an oblique lateral view after internal fixation of intertrochanteric fracture associated with a lower odds of postoperative cutout, independently of the TAD? (2) Is postoperative sliding of the lag screw after fixation associated with postoperative cutout? Patients with intertrochanteric fractures who were at least 65 years old and who had been treated with internal fixation in one of six facilities between July 2011 and December 2017 were included. All patients in the study group had lag screw cutout, and controls were selected by risk-set sampling of age-matched and sex-matched patients using a ratio of 4:1 for patients from each hospital. Of the 2327 intertrochanteric fractures, there were 36 patients (0.02 per person-year), with a mean age of 85 years; 89% (32) were women. In the control group, there were 135 controls. There was no difference in age or sex between the two groups. Sagittal reduction was evaluated using an immediate postoperative oblique lateral radiograph (anterior malreduction versus anatomic reduction or posterior malreduction). The association between anterior malreduction and the odds of cutout was estimated by conditional logistic regression analysis with the TAD and interaction between the TAD and the reduced position as covariates. As a sensitivity analysis, we estimated whether sliding within 2 weeks postoperatively was associated with cutout. After controlling for the potentially confounding variables of age and sex, we found that anterior malreduction was independently associated with a higher odds of cutout compared with anatomic reduction or posterior malreduction (adjusted OR 4.2 [95% CI 1.5 to 12]; p = 0.006). There was also an independent association between cutout and larger TAD (≥ 20 mm) (adjusted OR 4.4 [95% CI 1.4 to 14]; p = 0.01). However, the association between cutout and reduction was not modified by the TAD (adjusted OR of interaction term 0.6 [95% CI 0.08 to 4]; p = 0.54). Postoperative sliding ≥ 6 mm within 2 weeks was associated with higher odds of cutout after adjusting for age and sex (adjusted OR 11 [95% CI 3 to 40]; p < 0.001). In patients older than 65 years with intertrochanteric fractures, anterior malreduction on a lateral oblique view was associated with much greater odds of postoperative cutout than anatomic reduction or posterior malreduction. Because anterior malreduction is within the surgeon's control, our findings may help surgeons focus on intraoperative reduction on an oblique lateral view to prevent cutouts. Although this factor is a reliable indicator, the results should be applied to cephalomedullary nails, because there was only one patient with cutout among those with sliding hip screws. Because this study was conducted in a homogenous Japanese population, future studies should focus on the association between anterior malreduction and cutout in people of different ethnicities, adjusting for confounding factors such as implant type and surgeon level. Level III, therapeutic study.

Variable Adjustment Methods for Hemihamate Autograft Arthroplasty in Proximal Interphalangeal Joint Fracture/Dislocations: A Surgical Technique Revisited and Case Series.

Proximal interphalangeal joint fracture/dislocations, even after surgical correction, often lead to long-term complications including posttraumatic arthritis, prolonged joint stiffness, and chronic joint instability. A wide range of surgical techniques has been devised to resolve this issue, but none has been promising enough. Despite this circumstance, arthroplasty using a hemihamate autograft of size and contour that match the middle phalangeal base has progressed into one of more acceptable methods that provide both articular congruency and osseous stability. In this article, we introduce various types of proximal interphalangeal joint fracture/dislocations and individualized surgical approach using hemihamate autograft and lag screw and/or hook plate as fixation methods.