Avoidance of malreduction of proximal femoral shaft fractures with the use of a minimally invasive nail insertion technique (MINIT)

History and Evolution of Hip Design to Decrease Failure

SUMMARY

The evolution of fracture fixation designs over the past 100 years is coupled with incredible advances in materials and manufacturing technology. Failures are unavoidable and should be evaluated from the perspective of refining our technology and technique to improve patient outcomes. Failure after intramedullary fixation of hip fractures is multifactorial with contributions from an unsuccessful surgery, some preventable, some unavoidable, and rarely, design and manufacturing errors. However, whenever implants are disseminated to large population groups with variable individual anatomy, physiology, and associated comorbidities, unexpected and unpredicted weaknesses in the design and surgical technique will be discovered. Surgeons have multiple choices for nail selection with specific and critical technical requirements. The surgeon should evaluate each patient individually and determine the treatment based on patient anatomy and morphology of the fracture. The surgical approach should be modified over time after deciding how best to improve surgical treatment based on the current scientific studies.

Comparing the rates and modes of failure of two third generation cephalomedullary nail systems in the treatment of intertrochanteric hip fractures

INTRODUCTION

Cephalomedullary (CMN) implants are commonly used to address elderly intertrochanteric hip fractures. Multiple CMN implant systems exist with subtle variation between manufacturers. Multiple modes of CMN failure have been described in the literature. The present study assessed the local modes and rates of construct failure (nail fracture, cut-out and non-union) of two such implants, after a change in implant supply provided the opportunity for retrospective comparison. Additional investigation was undertaken to assess whether any predictors of failure could be identified based on common radiographic measurement parameters.

METHODS

Based on local implant records, all consecutive patients who suffered an intertrochanteric fracture, treated at a tertiary care hospital with a cephalomedullary nail from January 2014 to January 2018 were included. Patients were excluded if they received a CMN for pathologic fracture. Within the collection period all patients received either a Synthes Trochanteric Fixation Nail (TFN) or Zimmer Natural Nail (ZNN). Patients were retrospectively assessed for fracture reduction and implant technique parameters at the time of initial surgery. Radiographic data were assessed at minimum two years post-operatively to assess for union. Patient demographic data was followed to assess rate and mode of failure.

RESULTS

Six hundred and sixty-two patients were included in the study, from which a propensity matched cohort was derived. Comparing across equivalent cohorts, no differences in the rate or mode of construct failure were identified between the TFN and ZNN. When assessing the entire cohort we observed 39 construct failures (5.9%), which included 31 instances of nail cutout (4.7%), 4 episodes of nail fracture (0.6%) and 4 failures related to non-union (0.6%). Tip to apex distance, sagittal malalignment and Cleveland zone were identified as significant predictors of nail failure.

CONCLUSION

No difference in rates or modes of failure were identified between the TFN and ZNN constructs. Similar to previous reports we again identified the impact of tip to apex distance on construct failure and further identified Cleveland zone and sagittal malalignment as significant risks for failure.

Retrograde entry portal for cephalomedullary nailing in difficult subtrochanteric fractures

An entry point medial to the tip of the greater trochanter is considered optimal for antegrade femur nailing. The deforming forces in a subtrochanteric fracture often make it difficult to establish a perfect entry point during antegrade cephalomedullary nailing. To overcome this problem, we report a simple technique of making a retrograde entry portal for select difficult subtrochanteric fractures. The technique was used in 12 subtrochanteric fractures. Our indications were morbid obesity, revision nailing and atypical fractures. The technique involves creating a nail entry portal through the fracture from distal to proximal taking advantage of the abducted proximal fragment. Fracture reduction and nail insertion then proceeds in a standard manner. Additional reaming of the thick endosteal lateral cortex through the fracture was performed in atypical fractures. Satisfactory fracture reduction was achieved in all patients and 11 out of the 12 fractures united in the series. 1 patient developed an infected nonunion and was considered failure of treatment. The retrograde entry portal is a valuable alternative method that can be considered in nailing of difficult subtrochanteric fractures to establish an ideal entry point and nail trajectory.

Evaluation and management of atypical femoral fractures: an update of current knowledge

Atypical femoral fractures are often attributed to the use of anti-resorptive medications such as bisphosphonates (BP). Whilst they have proven effects on fragility fracture prevention, clinical and laboratory evidence is evolving linking BP-related suppression of bone remodelling to the development of atypical stress-related sub-trochanteric fractures (Shane et al. in JBMR 29:1-23, 2014; Odvina et al. in JCEM 90:1294-301, 2005; Durchschlag et al. in JBMR 21(10):1581-1590, 2006; Donnelly et al. in JBMR 27:672-678, 2012; Mashiba et al. in Bone 28(5):524-531, 2001; Dell et al. in JBMR 27(12):2544-2550, 2012; Black et al. in Lancet 348:1535-1541, 1996; Black et al. in NEJM 356:1809-1822, 2007; Black et al. in JAMA 296:2927-2938, 2006; Schwartz et al. in JBMR 25:976-82, 2010). Injuries may present asymptomatically or with prodromal thigh pain and most can be successfully managed with cephalomedullary nailing and discontinuation of BP therapy. Such injuries exhibit a prolonged time to fracture union with high rates of non-union and metal-work failure when compared to typical subtrochanteric osteoporotic femoral fractures. Despite emerging literature on AFFs, their management continues to pose a challenge to the orthopaedic and extended multi-disciplinary team. The purpose of this review includes evaluation of the current evidence supporting the management of AFFs, clinical and radiological features associated with their presentation and a review of reported surgical strategies to treat and prevent these devastating injures.

Development of a novel fracture fragment stabilization system for minimally invasive osteosynthesis and in vitro comparison to traditional Kern bone reduction forceps

OBJECTIVE

To develop and evaluate a novel fracture fragment stabilization system, the Sirius minimally invasive bone reduction handle system (SMH), in an artificial fracture model (FxM) simulating a canine femoral fracture repair with a minimally invasive orthopedic approach.

STUDY DESIGN

In vitro experimental study.

SAMPLE POPULATION

Synthetic fractured femurs with soft-tissue coverage analog (n = 8).

METHODS

The developed SMH consisted of modified Kern forceps connected with existing external skeletal fixation components. Intramedullary Steinman pin placement with the SMH or traditional Kern forceps only (KO) was performed by 16 participants in randomized order. Demographics and surgical experience of participants and outcome variables (fragment movement, early/final gap formation, time of procedure, assessed practicability by visual analog scale) were recorded and statistically evaluated.

RESULTS

The SMH was more difficult and took longer to assemble (P = .031 and P = .008); SMH resulted in a smaller final reduction gap (P = .008). More surgical experience resulted in faster surgery times (R² = 0.766) but was not correlated with final fracture gap formation.

CONCLUSION

The SMH was associated with reduced fragment gap formation in this simulated setting.

CLINICAL SIGNIFICANCE

The SMH may be helpful for maintaining reduction of femoral fractures in dogs. Additional studies of the SMH should be conducted to fully assess the effectiveness and practicality in clinical cases.

Greater trochanteric versus piriformis fossa entry nails for femur shaft fractures: Resolving the controversy

BACKGROUND

Intramedullary nailing is the treatment of choice for shaft of femur fractures in adults. Antegrade nails involve entry through either piriformis fossa (PE) or greater trochanteric (GT) tip. The superiority of one entry point over the other is a matter of debate, and the present review was done to determine the same.

RESEARCH QUESTION

Is GT entry for antegrade femur nailing superior to the PE for shaft femur fractures in adults?

OBJECTIVE

The present systematic review was conducted to determine the superiority of one entry point over the other by comparing the outcome parameters like operative time, exposure to fluoroscopy, mal-unions, non unions, abductor weakness, varus malalignment and Harris Hip scores (HHS).

METHODOLOGY

Three databases of PubMed, EMBASE and SCOPUS were searched for relevant articles that directly compared GT with PE for nailing in shaft femur fractures in adults.

RESULTS

We analysed a total of 9 studies published between the years 2011-2017. There were 5 retrospective and 4 prospective studies, out of which 3 were randomised. The total number of patients was 256 in GT group and 460 in PE group.

OUTCOMES

There was significant superiority of GT entry over PE on meta analysis; lesser operation time: standard mean difference (SMD): -21.01; lesser exposure to fluoroscopy : SMD: 36.36; lesser incidence of abductor weakness: Odd's ratio (OR): 14.35; better functional outcome (HHS): SMD -2.48.

CONCLUSION

GT entry nails are superior to PE nails for treating shaft of femur fractures in adults. They have a shorter learning curve and better functional outcomes, however the rates of union are comparable in both.

Provisional Plating of Subtrochanteric Femur Fractures Before Intramedullary Nailing in the Lateral Decubitus Position

Subtrochanteric femur fractures remain a challenge for surgeons to obtain and maintain adequate reduction and stable fixation. For this reason, multiple techniques have been described, but we are unaware of a detailed contemporary description of the combination of provisional plating before intramedullary fixation in the lateral decubitus position. We present our technique as it was used from 2011 to 2015 to treat 22 fractures and how it compared clinically to the other 48 subtrochanteric femur fractures treated during that period. The clinical and radiographic outcomes for all fractures were evaluated. The operative time was shorter when no open reduction was used but open cases showed no significant difference when using a provisional plate. Those patients treated with provisional plating were shown to have higher blood loss values and longer operative times, but when looking at the outcomes, the rate of malunion, which was defined as >5 degrees of angulation on postoperative radiographs, was significantly lower at 0% in the provision plating in the lateral decubitus position subset compared with the remaining subtrochanteric fractures, 27.7% (P = 0.013). As the quality of reduction and stability of fixation are the most significant factors in determining outcomes of subtrochanteric femur fractures, this study shows that this technique is a valuable tool in an orthopaedist's armamentarium and present it as such.

Implications of three-dimensional modeling of the proximal femur for cephalomedullary nailing: An Asian cadaver study

PURPOSE

To determine the variability in the ideal entry point of cephalomedullary (CM) nail around the greater trochanter (GT) and the consequent conformity with the proximal femur by analyzing three-dimensional (3D) modeling and virtual implantation MATERIALS AND METHODS: A total of 105 cadaveric femurs (50 males and 55 females) underwent continuous 1.0mm slice computed tomography (CT) scans. CT images imported into Mimics^® software to reconstruct the 3D model of the proximal femur and medullary canal. PFNA-II^® was processed into a 3D model using a 3D-sensor at the actual size and optimally implanted in the proximal femur model using Mimics^® software. The ideal entry point, nail conformity with the proximal femur, and the relationship between the entry point and adjacent structures were assessed.

RESULTS

The ideal entry point was located a mean of 2.38mm (SD, 3.53mm) medial to the tip of GT. No lateral cortex impingement of the proximal femur occurred in the coronal plane based on the recommended point. However, a disparity in the sagittal plane between the proximal shaft and nail curvature was found in 47 models (44.8%). Rotation and magnification of the 3D model exposed all nails above the surface of the medial side of the GT. The proximal nail end was contained entirely within bone and circumferential endosteal cortical contact was present at the nail-bone interface.

Healing of Atypical Subtrochanteric Femur Fractures After Cephalomedullary Nailing: Which Factors Predict Union?

OBJECTIVES

The purpose of this study was to determine the healing rate and time to union of atypical subtrochanteric fractures treated with cephalomedullary nailing.

DESIGN

Retrospective review, descriptive, and analytic study.

SETTING

Six level 1 trauma centers.

PATIENTS/PARTICIPANTS

The study included 42 patients with 48 displaced, atypical, bisphosphonate-associated subtrochanteric femur fractures who underwent surgical intervention.

INTERVENTION

Cephalomedullary femur nailing.

MAIN OUTCOME MEASUREMENT

The main outcome measures were radiologic healing and time to union.

RESULTS

The primary healing rate after cephalomedullary nailing of bisphosphonate-associated subtrochanteric femur fractures was 68.7% (33/48 patients). Mean time to union was 10.7 months. Malalignment was determined using the differences in neck-shaft angle (the difference between the normal side and the surgically repaired side) and sagittal angulation. These all proved to be significantly correlated with failure and delayed healing time. The cutoff points for neck-shaft angle, difference in neck-shaft angle, and sagittal angulation were 125.6, 4.4, and 5.5 degrees, respectively (receiver operating characteristic curve analysis).

CONCLUSIONS

The healing rate of atypical subtrochanteric femur fractures treated with cephalomedullary nailing is lower than that previously reported for atypical femur fractures. The quality of fracture reduction proved to be the most important factor in bony union and time to union.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Contemporary management of subtrochanteric fractures

Cephalomedullary interlocking nails that allow for trochanteric entry and minimally invasive fixation have revolutionized the contemporary management of subtrochanteric fractures with improved union rates and decreased incidence of fixation failure. The most successful alternative to intramedullary fixation remains the angled blade plate. Despite biomechanical superiority of contemporary intramedullary implants to previous intramedullary devices, the importance of achieving and maintaining satisfactory fracture reduction prior to and during hardware insertion cannot be overemphasized. In comminuted and more challenging fractures, additional techniques, such as limited open reduction with clamps and/or cables, can allow for canal restoration and more anatomic reductions prior to and/or during nail insertion.

Open reduction and intramedullary stabilisation of subtrochanteric femur fractures: A retrospective study of 56 cases

Subtrochanteric femur fractures commonly present with predictable displacement because of the deforming muscle forces acting upon the proximal femur. For this reason, successful closed reduction and femoral nailing can be a technically demanding procedure. Open reduction prior to nail placement has been advocated to improve and maintain anatomic fracture alignment. The purpose of this study was to evaluate the results of patients with closed subtrochanteric femur fractures treated with open reduction and a reamed antegrade statically locked intramedullary nail. An initial query of our database identified 154 patients who had sustained a subtrochanteric femur fracture over the defined study period. Ninety-six patients had adequate radiographic and clinical follow-up. Fifty-six (58%) patients were treated with open reduction and nail placement. There were no wound complications or infections and all patients went on to successful osseous union. There was no loss of reduction and a final coronal and sagittal plane deformity of <5 degrees in 55 of 56 (98%) patients. Open reduction of closed subtrochanteric femur fractures followed by intramedullary nailing leads to high union rates with rare complications.

Treatment of two-part proximal humerus fractures: intramedullary nail compared to locked plating

BACKGROUND

Two-part proximal humerus fractures are common orthopedic injuries for which surgical intervention is often indicated. Choosing a fixation device remains a topic of debate.

PURPOSE

The purpose of this study is to compare two methods of fixation for two-part proximal humerus fractures, locking plate (LP) with screws versus intramedullary nailing (IMN), with respect to alignment, healing, patient outcomes, and complications. To our knowledge, a direct comparison of these two devices in treating two-part proximal humerus fractures has never before been studied. We hope that our results will help surgeons assess the utility of LP versus IMN.

METHODS

A retrospective chart review was performed on 24 cases of displaced two-part surgical neck fractures of the humerus. Twelve shoulders were treated using IMN fixation and 12 others were fixated with LP. Data collected included sociodemographic, operative details, and postoperative care and function.

RESULTS

Radiographic comparison of fixation demonstrated an average neck-shaft angle of 124° and 120° in the IMN group and LP group, respectively. Adjusted postoperative 6-month follow-up range of motion was 134° of forward elevation in the IMN group and 141 in the LP group. The differences in range of motion and in complication rates were not found to be significant.

CONCLUSIONS

Our results suggest that either LP fixation or IMN fixation for a two-part proximal humerus fracture provides acceptable fixation and results in a similar range of shoulder motion. Although complication rates were low and insignificant between the two groups, a trend toward increased complications in the IMN group is noted.

Intramedullary nails for pediatric diaphyseal femur fractures in older, heavier children: early results

PURPOSE

A common treatment for pediatric femur fractures is intramedullary nail (IMN) insertion. Elastic stable intramedullary nails (ESINs) are often used for these procedures in heavier patients, but the potential for complications and malunion is greater. We describe here a rigid IMN specifically designed for adolescents, the adolescent lateral entry femoral nail (ALFN). The purpose of this study was to compare the recovery and complications for patients treated with ESINs to those treated with the ALFN.

METHODS

Our study design was a retrospective cohort study. We performed a review of medical records of 22 children ages 10-17 requiring surgical fixation of a femur fracture for a 2½-year period. Patients selected for the study had traumatic diaphyseal femur fractures and were treated with ESINs without end-caps or ALFNs. Our analyses evaluated injury, surgical, and outcome information for all patients.

RESULTS

Twenty-two patients were eligible for inclusion and were divided into two groups according to their treatment: the ESIN group with 7 patients and the ALFN group with 15 patients. We then performed a comparison of complications and recovery for these patients. The mean time to full weight-bearing was significantly less for the ALFN group (4.1 weeks; SD, 2.2), than the ESIN group (9.4 weeks; SD 3.9). There was no statistical difference in the incidence of major or minor complications.

CONCLUSIONS

Older, heavier pediatric patients treated for femur fracture with ALFNs had a shorter recovery time than similar patients treated with ESINs. However, the outcomes for both groups were satisfactory.

Intramedullary nailing: evolutions of femoral intramedullary nailing: first to fourth generations

Intramedullary femoral nailing is the gold standard for femoral shaft fixation but only in the past 27 years. This rapid replacement of closed traction and cast techniques in North America was a controversial and contentious evolution in surgery. As we enter the fourth generation of implant design, capabilities, and surgical technique, it is important to understand the driving forces for this technology. These forces included changes in radiographic imaging capabilities, biomaterial design and computer-assisted manufacturing, and the recognition of the importance of mobilization of the trauma patient to avoid systemic complications and optimize functional recovery.

Simultaneous use of cannulated reamer and schanz screw for closed intramedullary femoral nailing

Introduction. Closed reduction is a critical component of the intramedullary nailing and at times can be difficult and technically challenging resulting in increased operative time. Fluoroscopy is used extensively to achieve closed reduction which increases the intra-operative radiation exposure. Materials and Methods. Sixty patients with femoral diaphyseal fractures treated by locked intramedullary nailing were randomized in two groups. In group I, fracture reduction was performed under fluoroscopy with a cannulated reamer in the proximal fragment or with simultaneous use of a cannulated reamer in the proximal fragment and a Schanz screw in the distal fragment. Patients in group II had fracture reduction under fluoroscopy alone. Results. Closed reduction was achieved in 29 patients in group I and 25 patients in group II. The guide wire insertion time, time for nail insertion and its distal locking, total operative time, and total fluoroscopic time were 26.57, 27.93, 68.03, and 0.19 minutes in group I, compared with 30.87, 27.83, 69.93, and 0.24 minutes in group II, respectively. The average number of images taken to achieve guide wire insertion, for nail insertion and its locking and for the complete procedure in group I, respectively, was 12.33, 25.27, and 37.6 compared with 22.1, 26.17, and 48.27, respectively, in group II. Conclusion. The use of cannulated reamer in proximal fragment as intramedullary joystick and Schanz screw and in the distal fragment as percutaneous joystick facilitates closed reduction of the fracture during closed intramedullary femoral nailing with statistically significant reduction in guide wire insertion time and radiation exposure.

Functional outcome after antegrade femoral nailing: a comparison of trochanteric fossa versus tip of greater trochanter entry point

OBJECTIVES

This study was performed to explore the relationship between entry point-related soft tissue damage in antegrade femoral nailing and the functional outcome in patients with a proximal third femoral shaft fracture.

DESIGN

Retrospective clinical trial.

SETTING

Level I university trauma center.

PATIENTS

Seventeen patients with a high femoral shaft fracture treated with an antegrade femoral nail joined the study.

INTERVENTION

Nine patients with an Unreamed Femoral Nail (UFN; Synthes, Bettlach, Switzerland) inserted at the trochanteric fossa and eight patients with a long Proximal Femoral Nail (PFN; Synthes) inserted at the tip of the greater trochanter.

MAIN OUTCOME MEASUREMENTS

Pain, gait, nerve, and muscle function along with endurance.

RESULTS

Five patients with a UFN had a positive Trendelenburg sign and a reinnervated superior gluteal nerve after initial injury of the nerve at operation. None of these findings occurred in the long PFN group (P = 0.01). Isokinetic measurements showed diminished abduction as well as external rotator function in the UFN group rather than in the long PFN group. Leg endurance was significantly lower in patients with a UFN.

CONCLUSIONS

Compared with the trochanteric fossa, femoral nailing through the greater trochanter tip may decrease the risk of damage to the superior gluteal nerve and intraoperative damage to the muscular apparatus of the hip region, resulting in some improved muscle function. Therefore, a lateral entry point may be a rational alternative for conventional nailing through the trochanteric fossa.

Is there a standard trochanteric entry site for nailing of subtrochanteric femur fractures?

OBJECTIVES

To evaluate the variability of the ideal trochanteric starting point as a possible cause for malreduction of subtrochanteric fractures and to analyze the accuracy of contralateral templating to predict correct entry site.

METHODS

Standardized anteroposterior pelvis radiographs of 50 patients were evaluated by two independent reviewers. Patients with advanced osteoarthritis, severe hip deformity, and radiographs with asymmetric hip rotation were excluded. Ideal nail entry site was established using a template for a trochanteric nail with a 6° proximal bend. The distance from the greater trochanteric tip to the ideal nail entry site was measured. Additionally, offset of the greater trochanter tip from the femoral longitudinal axis was measured. Interobserver reliability and accuracy of contralateral templating were evaluated.

RESULTS

The ideal entry point ranged from 16 mm medial to 8 mm lateral to the trochanteric tip (mean, 3 mm medial; standard deviation, 5 mm). In 70% of patients, the ideal entry point was medial to and in 23% lateral to the tip of the greater trochanter. Ideal entry points were located within 2 mm of the trochanteric tip in 29% and within 4 mm in 44% of patients. The location of the ideal entry point relative to the trochanteric tip had a weak correlation with patient height and neck shaft angle (r: -0.23 and r: -0.35, respectively). Interobserver reliability and agreement between left and right side measurements were strong (intraclass correlation coefficient: >0.94 and >0.88, P < 0.001, respectively). The mean measurement differences between sides was 0 mm (95% confidence interval: -1 to 1). Greater trochanter offset averaged 15 mm (range, 5-26 mm; standard deviation: 5) on the right and 15 mm (range, 5-25 mm; standard deviation: 5.1) on the left (P = 0.95).

CONCLUSION

A high degree of variability exists for the ideal trochanteric entry site. The trochanteric tip represents the ideal starting point in only the minority of cases. Preoperative contralateral templating provides an accurate means for establishing a patient-specific entry point to minimize fracture malreduction.

Correction of malalignment in proximal femoral nailing--Reduction technique of displaced proximal fragment

INTRODUCTION

External rotation, abduction, and flexion of the proximal fragment in proximal femoral fracture are one of the main obstacles in nailing. We introduced simple surgical technique using a long hemostatic forceps to achieve fracture reduction and to facilitate preparation of the nail entry site.

METHOD

Using this reduction method, 16 patients with displaced subtrochanteric or proximal femoral shaft fracture were treated through cephalomedullary or femoral nailing between January 2005 and May 2007.

RESULTS

The difference of the neck-shaft angle in the AP view compared to the normal side was 2.2 degrees (range, 0-5 degrees). Anterior angulation in the lateral view was 1.6 degrees (range, 0-15 degrees). One case of malunion was caused by too anterior nail insertion in the lateral view. Bone union was achieved in all cases with an average consolidation time of 5.1 months (range, 3-9 months).

CONCLUSION

A simple reduction technique using readily available instruments in the operating room (hemostatic forceps) is quite useful in reducing proximal femoral fragments in cephalomedullary or femoral nailing.

Splitting of the proximal femur with a new femoral nail

We present a case of a 19-year-old woman with a closed diaphyseal femur fracture and who had fixation of the fracture using a newer lateral entry nail, which resulted in an intraoperative proximal femur fracture. The patient underwent revision the following day and subsequently returned to regular activity without signs of implant failure or loss of reduction at latest follow-up. Caution should be exercised with the use of new implants that require a change in customary technique. In addition, some concern must be raised by the amount of offset from the top of this particular nail to its long axis.

Percutaneous/minimally invasive techniques in treatment of femoral shaft fractures with an intramedullary nail

Intramedullary nailing of the femur is often the treatment of choice in isolated fractures of the femoral shaft. Some surgeons are reticent to use intramedullary nailing for proximal and distal femoral fractures. However, indications for femoral nailing can be appropriately extended to highly comminuted fractures as well as distal and proximal fractures when the correct technique and reduction maneuvers are utilized. Implementation of these techniques will also respect the critical soft tissue envelope that is so important in fracture healing. Deforming forces of the muscles of the hip, knee and thigh are neutralized with reduction tools applied percutaneously, blocking screws and Schanz pins. Mastery of these techniques and appropriate reduction are incumbent on the orthopaedic surgeon treating femoral shaft fractures.