Nail Failure Research Articles

High resolution time domain reflectometry and coaxial cable for soil nail monitoring

Soil nailing is a popular application in soil slope stabilization. Failure of soil nailing could be mainly due to the issue of installation such as inaccuracy of actual length of the soil nail and integrity of cement grout annulus during grouting. This study focuses on using non-destructive technique of time domain reflectrometry (TDR) to monitor the quality of soil nail. TDR is originally used to detect changes in geometry and electromagnetic properties (dielectric or magnetic) happening along its transmission cable and detect the damage or leakage from the cable. The objective of this study is to use high resolution TDR and coaxial cable to detect changes of grout condition in soil nail. Results confirm the suitability of high resolution TDR and coaxial cable to detect void length which relates to grout condition in soil nail. The findings conclude that high resolution TDR model T631 and coaxial cable type RG-6 are capable to detect even small size void and is suitable to be applied for soil nail monitoring.

Femoral offset loss and internal arch restoration defect are correlated with intramedullary nail cut-out complications after pertrochanteric fractures: a case-control study.

In a previous study, we investigated the link between the femoral offset (FO) loss by trochanteric impaction (TI) and cut-out complication occurrence after pertrochanteric fractures. Three major factors are likely to drive to failure after intramedullary nailing (IN): fracture stability, reduction quality and osteosynthesis quality. We wanted to investigate the quality of the fracture reduction through the TI and the neck-shaft angle (NSA) measurement and correlate these parameters with the risk of mechanical failure occurrence. It was a retrospective multicentric one case-one control match design study with age and gender randomization. The cases presented a mechanical failure of nailing: [Formula: see text] in percentage. Femoral rotation was taken into account, and all TI were rotation-corrected (TIcorrected). Rotation-corrected neck-shaft angles (NSAcorrected) were calculated. The neck-shaft angle gap between the fractured and the healthy sides (NSAgap) was a ratio: [Formula: see text] in percentage. The tip-apex distance (TAD) was measured. Absolute values of TIcorrected and NSAgap were analyzed. Twenty-one cases and 21 controls were examined. The average TIcorrected rate was 30% for the cases and 11% for the controls (p = 0.007). A 13% TIcorrected threshold had maximum specificity and sensitivity, equal to 71%. The average TAD was 27mm for cases and 19mm for controls (p = 0.004). The average NSAgap rate was 7% for the case group and 4% for the control group (p = 0.009). The areas under the ROC curves for TIcorrected, TAD and NSAgap were 0.73, 0.73 and 0.66, respectively. Closed reduction and exclusive implantation of IN do not seem optimal in case of FO or NSA restoration failure after pertrochanteric fractures. Level III, case-control study.

The PRECICE magnetic IM compression nail for long bone nonunions: a preliminary report

IntroductionThe magnetic intramedullary (IM) compression nail is capable of providing sustained compression for the treatment of nonunions of long bones. This ability was previously only possible with the use of external fixation. We asked the following questions: How effective is the IM compression nail at achieving union? How do we know when adequate compression has been attained? Which types of nonunions are good candidates for this treatment?Materials and methodsFourteen patients with nonunions of the tibia (5) or femur (9) were treated with the PRECICE IM compression nail. The average age was 49 years number of previous surgeries was 1.9, 7 were atrophic and 7 normotrophic, 3 were metaphyseal and 11 diaphyseal. All PRECICE IM nails were pre-distracted prior to implantation. Compression was applied post-operatively until the locking bolts were seen on X-ray to be bending or the nail was no longer shortening despite applying the external magnet.ResultsUnion was achieved in 13/14 cases. The time to union was 24.5 weeks (range 11–60). The two proximal tibia metaphyseal nonunions, both deformed into varus (4°) and flexion (10°) after compression was applied with one failing to unite. The distal tibia metaphyseal and diaphyseal nonunions did not deform upon compression. Three patients had positive cultures and were treated with IV antibiotics for 6 weeks followed by 3 months of oral suppression without subsequent infection. No mechanical nail failures were seen.ConclusionsThe IM compression nail was successful at applying compression, preventing deformity, and obtaining union in all diaphyseal and in distal tibia metaphyseal nonunions. Signs of active compression are bending of the locking bolts and failure of the nail to shorten. Proximal tibia metaphyseal nonunion may not be suited for this treatment.

Implant Fracture Analysis of the TFNA Proximal Femoral Nail.

Mechanical failure of intramedullary nails is rare. This investigation was prompted by a series of cases of observed breakage of the recently introduced TFNA Proximal Femoral Nailing System (TFN [Trochanteric Fixation Nail]-Advanced; DePuy Synthes) in our region. Laboratory analysis and case data are presented, in contribution to post-market surveillance. Medical and imaging records from the 3 public tertiary orthopaedic trauma hospitals in Western Australia were reviewed. Relevant data of patients in whom breakage of the TFNA implant occurred between 2016 and 2018 were collected and analyzed. Laboratory review of retrieved implants was conducted at the Centre for Implant Technology and Retrieval Analysis (CITRA) in Western Australia. A total of 16 cases of TFNA implant breakage were recorded and analyzed. The predominant OTA/AO fracture classification was 31A3 (12 cases, 75%). The reduction quality was good in 10 cases, acceptable in 4 cases, and poor in 2 cases. The mean time to failure (and standard deviation) was 5.0 ± 2.2 months (range, 2.2 to 9.8 months). The treatment modality for the breakage was revision nailing in 11 cases, arthroplasty in 3, and nonoperative management in 2. All nails broke at the proximal screw aperture, with 1 nail additionally breaking at the distal aperture. Of 8 patients treated with a second TFNA implant for nail breakage, 3 (38%) returned with breakage of the revision implant. Laboratory analysis of the broken nails demonstrated a unique fracture pattern, with a stepped propagation pathway. This study represents the largest series, to our knowledge, of proximal femoral nail breakages in the published English literature and is the first that we are aware of to involve laboratory analysis of the TFNA implant. Changes to the nail design and/or alloy may have contributed to the observed cases of breakage, and this study will be followed by an evaluation of breakage rates in comparison with those of previous generations of nailing systems. We advise close clinical and radiographic surveillance of patients with unstable hip fracture patterns who undergo osteosynthesis with use of a TFNA implant. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Implant cut-out following cephalomedullary nailing of intertrochanteric femur fractures: Are helical blades to blame?

IntroductionImplant cut-out remains a common cause of cephalomedullary nail (CMN) failure and patient morbidity following surgical treatment of intertrochanteric femur fractures. Recent studies have suggested an increased rate of CMN cut-out with helical blades as opposed to lag screws. We compared rates of overall cut-out between helical blades and lag screws and used bivariate and multivariate analysis to determine the role of proximal fixation method among other variables on risk for cut-out. Subgroup analysis was performed on the basis of failure mechanism; superior migration (Fig. 2) versus medial perforation (Fig. 3). MethodsThree-hundred and thirteen patient charts were retrospectively reviewed over an 8-year period; 245 patients were treated with helical blades and 68 with lag screws. Radiographs were reviewed for fracture pattern, Tip-Apex Distance (TAD), Parker’s Ratio (PR) and reduction quality. Rate of implant cut-out was compared between groups and multiple logistic regression was used to analyze the ability of several independent variables to predict implant cut-out. ResultsTwenty cut-outs occurred; 15 with helical blades and 5 with lag screws. No difference in the rate of cut-out was observed between the two groups (p = 0.45). Poor fracture reduction was found to be a significant predictor of implant failure via bivariate and multiple logistic regression analysis (p = <0.01, OR 23.573). Helical blade fixation, fracture instability, TAD ≥ 25, and PR ≥ 0.45 were not predictive of implant cut-out during multivariate analysis. Similarly, patient smoking status and surgeon trauma fellowship training did not significantly increase the odds of implant cut-out. Failure by medial perforation occurred in 12 instances, all involving helical blades. Failure by superior migration occurred at a significantly higher rate with lag screws than helical blades (p = 0.02). ConclusionCMN cutout is likely multifactorial. A direct association between helical blade fixation and implant cut-out was not observed in our study. Amongst modifiable risk factors for implant failure, poorer fracture reduction was predictive of failure by cut-out. Subgroup analysis highlights differing modes of failure between lag screws and helical blades which warrants further investigation. Ideal TAD during helical blade fixation remains unknown.

Modes of failure of proximal femoral nail (PFN) in unstable trochanteric fractures

Modes of failure of proximal femoral nail (PFN) in unstable trochanteric fractures

A case of the failure of the intramedullary nail in an intertrochanteric femoral fracture

A case of the failure of the intramedullary nail in an intertrochanteric femoral fracture

Tension band plating of an anterior tibial stress fracture nonunion in an elite athlete, initially treated with intramedullary nailing: a case report

BackgroundLeg pain in athletes is a common condition and is often related to tibial stress fracture. When non-operative treatment fails, the optimal surgical treatment is controversial. The aim of this study was to report a case of tension band plating of an anterior tibial stress fracture nonunion, treated previously with intramedullary nailing. To the best of our knowledge, this is the first reported case in which tension band plating was placed without removing the preexisting intramedullary nail.Case presentationThe tibial shaft is a common location of stress fracture in athletes. Anterior tibial stress fractures are difficult to manage. When conservative treatment fails, intramedullary nailing is the mainstay of treatment. However, nonunion is a serious complication. In our case, a non-united anterior tibial stress fracture, treated with intramedullary nailing, was addressed with the application of a compression prebended plate over the nail in a 23-year-old French man of African origin who is an elite football player. At 3-months postoperatively he was pain free and started light exercises. At 6-months postoperatively, complete radiologic union of the fracture was evident. He was symptom free; he resumed at that time a full training program and he returned to play football at preinjury high competition level.ConclusionsCompression plating is a valuable method of treating non-united anterior tibial stress fractures. We believe that anterior tension band plating is superior to intramedullary nailing in managing anterior tibial stress fractures, not only after failure of intramedullary nailing, but also as a first-line surgical treatment. This technique offers advantages, such as no violation of the extensor mechanism and risk of anterior knee pain, and directly addresses the underlying problem of distraction forces acting on the anterior tibial cortex and compromising fracture healing. Especially in high-level athletes, who cannot tolerate prolonged inactivity, early surgical intervention of anterior tibial stress fractures with tension band plating is a reliable option that can accelerate recovery.

The Use of a Free Fibular Strut as a "Biological Intramedullary Nail" for the Treatment of Complex Nonunion of Long Bones.

Background:Nonunion of long-bone fractures is difficult to treat, especially when the bones are osteoporotic or there is a large bone gap as a result of repeated failure of the metallic nails or implants. In such cases, the use of an autologous intramedullary fibular strut graft may be a viable treatment option.Methods:Twenty-two patients with a complex nonunion of the shaft of the femur, humerus, or tibia were managed with a free autologous fibular strut graft for intramedullary fixation with use of closed or open methods. All patients had evidence of moderate to severe local osteoporosis and had a bone gap ranging from 4 to 20 mm. Nineteen patients had had 1 to 4 prior operations. The mean age was 51.5 years. The duration of nonunion ranged from 9 months to 4 years.Results:The mean time to union was 17 weeks (range, 8 to 26 weeks), and the mean duration of follow-up was 4 years (range, 6 months to 17 years). All but 2 patients had healing at the time of the latest follow-up.Conclusions:The identification of a viable option for the treatment of difficult nonunion in osteoporotic bones has been a challenge. The insertion of a free autologous intramedullary fibular strut graft provided mechanical stability, and osteogenesis occurred inside the medullary canal of the host bone.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Mechanical failure of a femoral lengthening nail: a case report

BackgroundThis case report describes the mechanical failure of a femoral lengthening nail in order to allow early recognition and prevent its occurrence.Case presentationA femoral lengthening nail was used to achieve goal distraction length over eight weeks and sustained a mechanical failure during progressive weightbearing. Re-distraction was attempted with subsequent non-weight-bearing status. Although the patient was not able to attain the original goal length, radiographs demonstrated stable shortening of the patient’s right lower extremity along with early signs of incomplete regenerate bone. She eventually received exchange nailing with bone graft.ConclusionPost-operative protocol and weight-bearing status should be further researched and standardized after re-evaluating the mechanical stiffness of the intramedullary nail construct.

Efficacy of calf self-weight traction reduction combined with locking plate for treatment of intertrochanteric fractures in the elderly

Objective To investigate the efficacy of calf self weight traction reduction combined with locking plate fixation for the treatment of intertrochanteric fractures in the elderly. Methods A retrospective case series study was conducted on the clinical records of 174 elderly patients with the modified Evans I-III types of fresh intertrochanteric fractures treated with locking plate from January 2012 to December 2015. According to treatment method, the patients were assigned to traction bed reduction with locking plate fixation (Group A, 62 patients) and calf self weight traction reduction with locking plate fixation (Group B, 112 patients). Group A comprised 32 males and 30 females, with age range of 65-91 years [(72.47±6.35)years]. Group B comprised 68 males and 44 females, with age range of 65-95 years [(73.23±6.05)years]. The time of reduction, operation time, incision length, intraoperative blood loss, frequency of fluoroscopy, postoperative drainage volume, hospital stay, postoperative weight-bearing standing time or walking time (ambulation time), surgical complications, and fracture healing were recorded. Harris and modified Barthel index score in Chinese(MBI-C) were used to evaluate the functional recovery of hip joint. Results All patients were followed up for 5-61 months (mean, 15 months), and noted with fracture healing. The time of reduction in Group A was (13.27±3.03)minutes, longer than that in Group B (0 minute) (P 0.05). There were no significant differences in the postoperative complications such as deep venous thrombosis, pulmonary infection, incisional infection, urinary tract infection, delirium, bed sores, cardiac insufficiency, electrolyte disturbance, and postoperative plate rupture between the two groups (P>0.05). The incidence of deep vein thrombosis was 9.7% (6/62) in Group A, and 4.5% (5/112) in Group B (P>0.05). No screw fracture, nail and plate combination failure, bone nonunion, or screw cut out of the femoral head were observed in both groups. Conclusions For the modified Evans I-III types of intertrochanteric fractures, both traction bed reduction and calf weight reduction with locking plate have equivalent efficacy. However, the latter method has advantages of shorter reduction and operation time and less intraoperative X-ray exposure, and hence is worthy of clinical application. Key words: Femoral fractures; Fracture fixation, internal; Aged; Self-weight traction reduction method

Fatigue failure of the cephalomedullary nail: revision options, outcomes and review of the literature.

Cephalomedullary nail (CMN) failure is a rare entity following hip fracture treatment. However, it poses significant challenges for revision surgery, both mechanically and biologically. Nail failure rates have been reported at <2%; however, no published studies have reported revision surgery procedures and their respective outcomes. We present a regional experience, with outcomes, of the revision options. We identified 20 fatigued CMNs that underwent four different revision procedures. Mean age was 73±15.24years, with a 3:1 female preponderance, and a median ASA grade of 3. Post-operative CMN radiographs demonstrated a significant number of fractures were fixed in varus, with reductions in neck-shaft angles post-operatively. A "poor" quality of reduction resulted in significantly earlier nail failure, compared to "adequate" and "good" (p=0.027). Tip-Apex Distance (TAD) mean was 23.2±8.3mm, and an adequate TAD with three-point fixation was seen in only 35% of cases. Mean time to failure was 401.0±237.2days, with mean age at failure of 74.0±14.8years. Options after failure included revision CMN nail, proximal femoral locking plate (PFLP), long-stem or restoration arthroplasty, or femoral endoprosthesis. Barthel Functional Index scores showed no significant difference at 3 and 12months post-operatively, nor any difference between treatment groups. Mean 12-month mortality was 30%, akin to a primary hip fracture mortality risk according to NICE guidelines. Mortality rates were lowest in revision nails. Subsequent revision rates were higher in the PFLP group. There is no reported evidence on the best surgical technique for managing the failed CMN, with no clear functional benefit in the options above. Good surgical technique at the time of primary CMN surgery is critical in minimising fatigue failure. After revision, overall mortality rates were equivalent to reported primary hip fracture mortality rates. Further multicentre evaluations are required to assess which technique convey the best functional outcomes without compromising 12-month mortality rates.

Risk factors for cut-out failure of Gamma3 nails in treating unstable intertrochanteric fractures: An analysis of 176 patients

BackgroundCut-out failure is one of the most common complications in the Gamma3 nail fixation system. The purpose of this retrospective study was to determine pre-operative or intra-operative risk factors for cut-out failure of lag screws in unstable, intertrochanteric fractures fixed with short Gamma3 nails. MethodsOne hundred and seventy-six patients over 60 years of age, with unstable intertrochanteric fractures (AO/OTA 31-A2, 31-A3) treated with short Gamma3 nails were included in this study. All patients completed a minimum of 1-year follow-up. Analysis of post-operative radiographs included assessment for cut-out failure of lag screw, appropriateness of the entry point, posterior lag screw axis, fracture gaps, posterior displacement of the proximal fragment, and tip-apex distance. ResultsOf the 176 patients in this study, 22 patients were identified with cut-out failure. Multivariate logistic regression analysis revealed that improper entry point in an antero-posterior projection (odds ratio 10.39, 95% confidence interval 1.74–78.4), posterior displacement distance of the proximal fragment in a lateral projection (odds ratio 1.35, 95% confidence interval 1.17–1.59), and female sex (odds ratio 17.14, 95% confidence interval 1.88–876.11) were correlated with cut-out failure. ConclusionThis study emphasizes the importance of an optimal position of reduction in the lateral projection in reducing the risk of cut-out failure. In addition, sex difference in bone mineral density, proximal femur geometry, and the bone strength in elderly females may explain why female sex is a risk factor.

Treatment with total hip arthroplasty for the failure of stable(3.1A1) femoral intertrochanteric fractures surgery using proximal femoral nail antirotation or dynamic hip screw

Objective To investigate the clinical effect of total hip arthroplasty in the treatment of failure of femoral intertrochanteric fractures(3.1A1.1-3) with proximal femoral nail antirotaion or dynamic hip screw. Methods A retrospective study was performed on 192 patients(192 hips) underwent total hip arthroplasty(THA) to cure failed femoral intertrochanteric fractures surgery using proximal femoral nail antirotation or dynamic hip screw from January 2007 to April 2016.The preoperative and postoperative data,from the reasons for internal fixation failure,imaging changes,improved Harris score and postoperative complications were analyzed. Results The scores of Harris in each group were significantly higher than those before operation(P<0.05). There was no significant difference between the two groups.There were more postoperative complications in the DHS group compared with PFNA group,and the difference was statistically significant(P<0.05). Conclusion The total hip arthroplasty in the treatment of femoral intertrochanteric fractures with proximal femoral nail or dynamic hip screw failure has good clinical results.The postoperative complications are more likely to occur in patients with DHS for the first time,there is no significant difference between the two prostheses of bone cement and non-bone cement. Key words: Femoral intertrochanteric fracture; Total hip arthroplasty; Dynamic hip screw; Proximal femoral nail antirotaion

An Indigenous Removal Method of a Broken Interlocking Nail

ABSTRACT Breakage of locking nail is an important cause of interlocking nail failure in femoral fractures. Usually, it takes place at one of the ends of the nail. Here we report an unusual extraction method of intramedullary femoral nail failure with breakage of nail proximal to distal locking holes. Such a scenario usually complicates further management. This case was managed with exchange nailing and bone grafting after removal of implant using a novel technique and using commonly available orthopedic instruments in the operation theater. Here, we briefly review the literature regarding such an unusual presentation and discuss in detail the possible etiology of such a presentation and the management options when facing such a complex situation. How to cite this article Kedawat A, Mathur AK, Kumar M, Sharma A, Gupta A. An Indigenous Removal Method of a Broken Interlocking Nail. J Mahatma Gandhi Univ Med Sci Tech 2017;2(1):38-40.

Retrograde femoral nail for distal femoral fractures

Objective: The objective of this study was to review and evaluate the use of Targon retrograde femoral nail ( Targon RF® nail ) for distal femoral fractures at Al Jalaa Trauma Hospital, a teaching hospital belongs to Benghazi University. Subjects and method: We reviewed 37 fractures in 36 patients treated by Targon RF nail between 2006 and 2015. The fractures consisted of 18 type A1, 14 type A3, 3 type C1, and 2 type C2 fractures. The relationship between clinical results and fracture type, surgical approach, and patient age were retrospectively reviewed. Results: All fractures healed clinically and radiologically. Twenty five patients maintained gait performance almost equivalent to that before injury, the rest had less satisfying performance because of associated injuries or fractures which delayed rehabilitation. Average operating time was 115 min±40 min. ROM in the knee of all patients was -5º±5º in extension and 110º±20º in flexion. Extension lag was affected by age and surgical approach. There were seven cases of valgus/varus deformities, and two cases with loosening of distal and proximal locking screws, but no breakage of screws or nail failure. Conclusion: Targon RF nail for distal femur fractures was satisfactory in our patients

Laboratory study of a new screw nail and its interaction in sand

Experimental results of a series of laboratory pullout tests on a new screw soil nail are presented. A review of the literature for the screw soil nails as well as a comparison of its performance with other conventional types of soil nails is discussed. The present investigation also examines the fundamental interface mechanism and attempts to define the associated rupture zones in cohesionless material with the aid of thin vertical bands of coloured sand cast in a large distinctly fabricated pullout box. The philosophy behind the design and development of the new screw nail is briefly described first followed by presentation of the laboratory testing procedure and its instrumentation. The results of the testings indicate that the slip mechanism, which controls the pullout behaviour, is rather different to the conventional soil nails and the resultant pullout capacity is higher when compared to this type soil nails. This effect is attributed to the geometry of the screw nail and the installation processes that result in the development of different soil stresses around the soil nail. In addition, the experimental pullout results demonstrate, contrary to the conventional soil nail, that the screw nail pullout capacity is dependent on the overburden pressure and that the failure planes extends out a certain radial distance from the soil–nail interface. From the test results, it is shown that the failure of the screw nail satisfies the Mohr–Coulomb failure condition, which is similar behaviour seen in the conventional soil nail tests.

Metallurgical Failure Analysis of Intramedullary Nail Used for Femoral Fracture Stabilization

Currently orthopedics challenge is the use of intramedullary nails to straighten diaphyseal femoral fractures. In this paper it was conducted a case study on an intramedullary nail used for femoral fracture stabilization, in the case of one young patient. The evolution was unfavorable to the fracture site and the implant failed after three month of first surgical intervention. Intramedullary nail dimensions were 300mm length and 10mm in diameter. The following investigations were made in order to establish the failure causes: determination of the chemical composition through spectral analysis, macrostructural analysis using stereomicroscopy, optical microstructural analysis using optical microscopy, fractographic analysis using scanning electron microscopy. The final conclusions showed that the metallic biomaterial used for manufacturing the intramedullary nail was approximately an austenitic stainless steel AISI 316L, but with major microstructural defects. Macro-structural analysis revealed the presence of two zones of cracking, which are very rare at austenitic stainless steels. Also breaking with a fragile character has radial front tear propagation. In longitudinal section, cracks were evidenced due to the extraction operation and also the presence of corrosion products was shown. From fractographic analysis it was determined that intramedullary nail failure was predominantly through the mechanism of brittle fracture that took place at the point of maximum bending of the implant fragile.

Load distribution between cephalic screws in a dual lag screw trochanteric nail.

BackgroundIt has been observed clinically that the Z-effect is a potential cause of failure of an intramedullary nail with two cephalic screws. It describes the migration behavior of the cephalic screws in the femoral head. The primary objective was to examine different cephalic screw configurations and test the load distribution between them as a function of their relative placement and their relative movement in the nail. It has been hypothesized that different cephalic screw positions may have an influence on the stress in the implant and bone and therefore on implant failures, such as the Z-effect.MethodsTo quantify the load distribution of a dual cephalic screw intramedullary femoral nail (Citieffe, Calderara di Reno, BO, Italy), a finite element model of the femur, focusing on the loading of the cephalic screws, was prepared. Four different screw lengths (90–105 mm) were examined. The investigation considered the stresses and strains in the bone and implant as well as the relative movement of the screws.ResultsIf the inferior cephalic screw had a shorter length, then the superior one and the femoral nail had to bear higher loads. In that case, the “equivalent von Mises stress” increased up to 10 % at the superior cephalic screw and up to 5 % at the femoral nail. The analysis of the relative movement showed that sliding of the inferior cephalic screw occurred in the nail. The total movement ranged from 0.47 to 0.73 mm for the different screw configurations.ConclusionsThe stresses were distributed more equally between the two cephalic screws in the bone and the implant if a longer inferior screw was used. The stresses in the bone and implant were reduced with a longer inferior cephalic screw. Therefore, a configuration using a longer inferior cephalic screw is preferable for trochanteric fracture fixation with a dual cephalic screw intramedullary device.

Exchange nailing for nonunion of diaphyseal fractures of the tibia: our results and an analysis of the risk factors for failure.

The aim of this study was to identify risk factors for the failure of exchange nailing in nonunion of tibial diaphyseal fractures. A cohort of 102 tibial diaphyseal nonunions in 101 patients with a mean age of 36.9 years (15 to 74) were treated between January 1992 and December 2012 by exchange nailing. Of which 33 (32%) were initially open injuries. The median time from primary fixation to exchange nailing was 6.5 months (interquartile range (IQR) 4.3 to 9.8 months). The main outcome measures were union, number of secondary fixation procedures required to achieve union and time to union. Univariate analysis and multiple regression were used to identify risk factors for failure to achieve union. Multiple causes for the primary nonunion were found for 28 (27%) tibiae, with infection present in 32 (31%). Six patients were lost to follow-up. Further surgical procedures were required in 35 (36%) nonunions. Other fixation modalities were required in five fractures. A single nail exchange procedure achieved union in 60/96 (63%) of all nonunions. Only 11 out of 31 infected nonunions (35.4%) healed after one exchange nail procedure. Up to five repeated exchange nailings, with or without bone grafting, ultimately achieved union in 89 (93%) fractures. The median time to union after exchange nailing was 8.7 months (IQR 5.7 to 14.0 months). Univariate analysis confirmed that an oligotrophic/atrophic pattern of nonunion (p = 0.002), a bone gap of 5 mm or more (p = 0.04) and infection (p < 0.001), were predictive for failure of exchange nailing Multiple regression analysis found that infection was the strongest predictor of failure (p < 0.001). Exchange nailing is an effective treatment for aseptic tibial diaphyseal nonunion. However, in the presence of severe infection with a highly resistant organism, or extensive sclerosis of the bone, other fixation modalities, such as Ilizarov treatment, should be considered. Exchange nailing is an effective treatment for aseptic tibial diaphyseal nonunion.