Systematic review of complications with externally controlled motorized intramedullary bone lengthening nails (FITBONE and PRECICE) in 983 segments

Magnetic Intramedullary Lengthening Nails Can Be Lengthened to Their Maximum Capacity with No Increased Nail Complications: A Study of Pediatric and Adult Populations

BACKGROUND

Magnetic intramedullary lengthening nails (MILNs) have become an increasingly popular method for long-bone distraction osteogenesis as a means of overcoming the limitations of bone lengthening with an external fixator. While factors such as nail diameter, alignment, and other mechanical characteristics have been associated with an increased risk of nail breakage, the relationship between the percentage of maximum lengthening utilized and nail breakage remains unexplored. We specifically assessed overall complications, with and without the inclusion of contractures, based on the amount of distraction (25% to 60%, 61% to 90%, and 91% to 100% of maximum).

METHODS

We retrospectively reviewed the records for 176 pediatric patients and 109 adult patients who had undergone limb lengthening and had ≥24 months of follow-up. The cohort was further stratified by the amount of distraction: 25% to 60% (n = 75 children and 30 adults), 61% to 90% (n = 72 children and 29 adults), and 91% to 100% (n = 29 children and 50 adults). The mean ages were 14.53, 13.53, and 12.49 years, respectively, in the pediatric cohorts and 27.1, 34.3, and 23.8 years, respectively, in the adult cohorts. The percentages of males and females were 48% vs. 52%, 54.2% vs. 45.8%, and 48.3% vs 51.7%, respectively, in the pediatric cohorts and 56.7% vs. 43.3%, 51.8% vs. 48.2%, and 58% vs. 42% in the adult cohorts. Complications included contractures, loss of length, bone fracture, axial deviation, nail failure, failure to lengthen, nail fracture/failure, and screw failure. Analysis of variance (ANOVA) was conducted to compare mean complications across the 3 distraction categories, and Tukey pairwise t tests were performed to compare mean complications between individual distraction categories.

RESULTS

Without contractures, complication rates were similar between the pediatric cohorts (p = 0.09): 4.0% (25% to 60% distraction), 13.9% (61% to 90% distraction), and 6.9% (91% to 100% distraction). With contractures included, complication rates were greatest in the 61% to 90% pediatric cohort (38.9%), followed by the 91% to 100% cohort (27.6%) and the 25% to 60% cohort (13.3%) (p = 0.002). Similarly, the adult population had a homogeneous rate of complications without the inclusion of contractures (p = 0.13). Likewise, we observed a similarly variable distribution with contractures considered, with the greatest frequency in the 91% to 100% group (36%), followed by the 61% to 90% group (31%) and the 25% to 60% group (10%) (p = 0.04).

CONCLUSIONS

This is the first study to explore the relationship between the percentage of nail lengthening and nail complications. The speculation that full extension of the nail could lead to increased nail bending or breakage was not consistent with our findings. This finding was consistent whether contractures were included or not.

LEVEL OF EVIDENCE

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

Results of Lower Limb Bone Lengthening by Using Motorized and Magnet-Driven Intramedullary Nails to Treat Limb Length Discrepancy

INTRODUCTION

Limb length discrepancies (LLDs) can be treated with limb lengthening using external fixation or intramedullary nails, such as PRECICE or FITBONE. PRECICE is a magnetically driven titanium nail, while FITBONE is a motorized nail; both use an external remote control. This study aimed to determine the complications, compensation of length difference, time needed for compensation, and healing outcome of bone lengthening using motorized or magnet-driven intramedullary nails among non-cosmetic limb lengthening cases.

METHODS

 This retrospective study was derived from a single surgeon's practice at a tertiary hospital in Jeddah, Saudi Arabia. Between 2009 and 2020, 15 patients with LLDs, with a mean age of 25.43 years (range 16-35 years), were identified. The study included congenital, post-traumatic, idiopathic, and acquired causes of LLDs. Outcomes were measured using complete lengthening and healing indices, which need the presence of three intact cortices out of four.

RESULTS

All patients achieved correction of their limb length without any device failure or nail breakage. The achieved limb length for all patients averaged 38.4 mm, ranging from 21 to 60 mm. No intraoperative complications were observed. Postoperatively, one patient reported knee stiffness, and another developed deep venous thrombosis. Duration of distraction (average 43.93 days, range 30-66 days) and the mean healing index was 32 days/cm for both the femur and tibia.

CONCLUSION

 This study confirms that intramedullary nail PRECICE 2 and FITBONE systems are reliable and effective lengthening devices for treating lower LLDs and deformities. These devices significantly reduce complications and achieve excellent outcomes.

Outcomes and outcome measurement instruments in lower-limb lengthening surgery: a scoping review to inform core outcome set development

BACKGROUND AND PURPOSE

 The heterogeneous outcomes used in lower-limb lengthening surgery (LLLS) complicate evidence synthesis, weakening systematic reviews and clinical recommendations, and reducing research impact. This scoping review maps the outcomes and outcome measurement instruments (OMIs) used in LLLS.

METHODS

This pre-registered review systematically identified studies reporting outcomes in adults or children who underwent LLLS. Outcomes and OMIs were extracted verbatim, and experts grouped outcome terms under headings using the COMET taxonomy.

RESULTS

 The search found 5,308 unique hits, including 149 studies from 2020-2024. They reported 2,939 verbatim outcomes, which were consolidated into 92 outcome headings and 27 subheadings. "Life impact" accounted for 13%, while "Clinical outcomes" represented 83% of all outcomes. Among the clinical outcomes, "Musculoskeletal and connective tissue" was the most reported outcome domain (68% of all outcomes). The most frequently reported outcomes were "Lengthening," "Bone healing," "Range of motion," "Limb alignment", and "Complications."

CONCLUSION

 Outcomes reported for people undergoing LLLS are heterogeneous and vary widely in the definitions and measurement tools used to collect them. Outcomes likely to be important to patients (life impact outcomes), such as quality of life and measures of physical function, are rarely reported.

Comparative Efficacy and Safety of Intramedullary Lengthening Nails vs. Alternative Techniques for Femoral Limb Lengthening: A Systematic Review and Meta-Analysis

BACKGROUND

Limb lengthening procedures are performed for various indications, including limb length discrepancies (LLDs) and short stature. This systematic review and meta-analysis compares the efficacy and safety of the newer motorized intramedullary lengthening nails (MILNs) with the traditional alternative techniques (ATs) for femoral limb lengthening.

METHODS

We conducted a comprehensive literature search in the Medline, Embase, Cochrane, Web of Science, and Scopus databases, inclusive of all dates through July 1, 2023, and without language restrictions. Factors mediating outcomes included problems, obstacles, complications, total adverse events, healing/consolidation index, time to full weight-bearing, lengthening accuracy, percentage of lengthening goal achieved, and duration of hospital stay. Effect sizes were quantified using STATA 17.0. Statistical algorithms employed were random effects model standardized mean differences (SMDs) for continuous outcomes and log risk ratios (RRs) for dichotomous outcomes, both with 95% confidence intervals (CIs).

RESULTS

Our meta-analysis included 10 studies comparing MILN with AT: 180 femurs in the MILN group and 160 femurs in the AT group. This was exclusively comprised of retrospective cohort studies. When compared with AT, limb lengthening procedures utilizing MILNs had significantly lower problems (log RR, -1.35; 95% CI, -1.93 to -0.77; p < 0.001), complications (log RR, -0.56; 95% CI, -0.90 to -0.22; p = 0.001), and total adverse events (log RR, -0.69; 95% CI, -1.17 to -0.21; p = 0.005), as well as a superior bone healing index (SMD, -0.80; 95% CI, -1.32 to -0.28; p = 0.003). However, no significant differences were found in obstacles, percentage of lengthening goal achieved, lengthening accuracy, time to full weight-bearing, and duration of hospital stay.

CONCLUSION

Limb lengthening with MILNs vs. AT may offer more favorable patient outcomes, lowering risk for problems, complications, and total adverse events, while optimizing the bone healing/consolidation index. However, the limitation of nonrandomized retrospective studies and high heterogeneity should be acknowledged.

LEVEL OF EVIDENCE

Level II (meta-analysis of cohort studies). See Instructions for Authors for a complete description of levels of evidence.

The need for state-of-the-art orthopedic surgical technology in low- to middle income countries : The case of distraction epiphyseolysis for limb lengthening in children with fibular hemimelia in Uzbekistan

INTRODUCTION

Amongst low- to middle income countries (LMIC), outdated and poorly documented orthopedic interventions may pose patients at risk for complications, serious adverse events (SAE) and unsatisfactory results, contradicting the World Health Organization's (WHO) Safe Surgery mandates. Use cases of conditions managed inadequately in LMIC environments are necessary to increase awareness of stakeholders and overcome deficiencies in collaboration with high-income countries (HIC).

MATERIALS AND METHODS

Methodological and clinical experts from the BG Kliniken and the Charité, Berlin, Germany, were invited to investigate established processes for musculoskeletal disorders and injuries in Tashkent, Uzbekistan. Congenital lower leg discrepancy due to fibular hemimelia was recognized as an illustrative example to prove the effectiveness of local treatment guidelines, still relying on distraction epiphyseolysis (chondrodiatasis) via an Ilizarov frame. Routine data from hospital records, images and outpatient follow-up examinations were compared to estimates from a review of studies of limb-lengthening by other techniques.

RESULTS

Data from 16 of 49 immature patients (10 males, 6 females, mean age at surgery, 4.2 ± 2.3 years) undergoing chondrodiatasis between 2017 and 2021 showed a mean limb elongation of 2.4 (95% confidence interval [CI], 1.9 to 2.9) cm after a median follow-up of 29 (range, 24 to 36) months. While no complications or SAE were noted, findings are compatible with a risk of 21% under an upper 97.5% confidence limit for null events. No reproducible classification of hemimelia, surgical or general complications, assessment of functional outcomes or health-related quality of life were available. The pooled average length gain from 21 studies on different other interventions with osteotomy enrolling 458 limbs was 5.1 (95% CI, 5.0 to 5.3) cm.

CONCLUSIONS OF THE USE CASE

Limb lengthening for hereditary fibular hemimelia in Uzbekistan revealed rather obsolete surgical algorithms, inadequate documentation, and unreliable outcome assessment. Resource limitations notwithstanding, knowledge transfer, implementation of current procedures and hardware, and international collaboration is vital to improve quality of care in this scenario and for the benefit of LMIC in general.

Extraction of a Broken PRECICE Bone Transport System: A Case Report and Technique for Residual Limb Salvage

Aim

To describe a surgical technique for the safe removal of a broken non-cannulated PRECICE bone transport nail (NuVasive Specialized Orthopedics) without compromising limb reconstruction.

Background

The removal of broken non-cannulated intramedullary lengthening nails (IMLNs) is challenging. Few techniques have been described for the safe removal of these devices without compromising bone salvage.

Case description

A 42-year-old male presented for complex right tibia reconstruction following a type IIIB open tibia fracture with a 92-mm bone defect. The bone defect was initially managed with an all-internal bone transport nail system (PRECICE bone transport). At the 13-month follow-up, the patient presented with a broken lengthening nail, varus limb deformity, and nonunion at the docking site. The nail components were extracted sequentially, and a burr hole was created in the distal segment of the nail through the nonunion site to facilitate removal. The residual varus deformity and tibial shaft nonunion were managed with a hexapod frame.

Conclusion

The IMLN was successfully removed without compromising limb reconstruction. By sequentially removing the components of the nail and altering the distal portion of the implant through the nonunion site, safe removal of the implant without further bone loss was achieved.

Clinical significance

This report describes an efficient technique for the removal of broken non-cannulated IMLNs when extractors are not available.

How to cite this article

Legler J, Martel S, Mailhot P, et al. Extraction of a Broken PRECICE Bone Transport System: A Case Report and Technique for Residual Limb Salvage. Strategies Trauma Limb Reconstr 2024;19(3):171-176.

Femoral Lengthening in Children with Congenital Femoral Deficiency: A Systematic Review

BACKGROUND

Congenital femoral deficiency (CFD) presents a significant challenge in pediatric orthopaedics, characterized by a spectrum of congenital anomalies ranging from mild femoral shortening to complete absence of the proximal femur and hip joint. This review aims at reviewing the latest concepts of femoral limb lengthening modalities in treating CFD, to explore the efficacy, complications, and long-term outcomes of various surgical techniques.

METHODS

A comprehensive search of the literature was performed for clinical studies involving lengthening in patients with proximal focal femoral deficiency (PFFD) in several databases.

RESULTS

We analyze the evolution of limb lengthening procedures, from the Wagner and Ilizarov methods to the latest advancements in distraction osteogenesis, and assess their role in addressing the functional needs of patients. We also analyze the possible risk factors for the occurrence of complications with each method and alternatives to avoid them.

CONCLUSION

The review highlights the importance of individualized treatment plans, considering factors such as the degree of femoral deficiency and the potential for achieving a functional limb length; however, it requires a multidisciplinary approach and careful preoperative planning to optimize patient outcomes. The review underlines the need for ongoing research to refine surgical techniques and to compare them and improve the quality of life for individuals with PFFD.

LEVEL OF EVIDENCE

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

Disintegration of Multiple Parts of a Bone Transport Nail During Planned Removal: A Case Report

CASE

A 34-year-old man with a distal tibia bone defect was treated with an intramedullary bone transport nail (Precice Bone Transport System, NuVasive). During planned removal after successful treatment, 7 separate subcomponents of the nail became disconnected and had to be separately removed using specialized instrumentation. This occurred despite adherence to the manufacturer's recommended technique for nail removal and in the absence of clinical or radiographic evidence of implant failure.

CONCLUSION

When planning for implant removal, surgeons should be aware of potential intraoperative disconnection of subcomponents of this magnetic bone transport nail and ensure that equipment for retrieval (e.g., very long endoscopy forceps) is available.

PRECICE nail for the management of posttraumatic bone defects with nonunion or malunion: Experience from a Latin American center

BACKGROUND

To evaluate the clinical outcomes using the PRECICE magnetic limb lengthening intramedullary nail for the correction of lower limb length discrepancies (LLD) in adults with posttraumatic nonunion or malunion defects in a Latin American center.

METHODS

A retrospective review of 25 adult patients with LLD associated with posttraumatic nonunion or malunion defects of femur or tibia treated with the PRECICE nail between January 2018 and December 2020. The primary outcomes considered were lengthening length achieved in mm, incidence of complications and quality of life (EQ-5D-3 L questionnaire).

RESULTS

Twenty-five cases (20 femoral and 5 tibial nails) were performed, with a median follow-up of 27 months (Interquartile range-IQR: 17.5 to 34.5). The average age was 36.5 ± 12.9 years; 10 cases were women. Fifteen cases had an LLD secondary to a malunion defect and 10 cases had an LLD secondary to a nonunion. PRECICE nails were inserted for the treatment of a median LLD of 40.0 mm (IQR: 30.2 to 74.2) in the femur and 30.0 mm (28.5 to 50.0) in the tibia. An accuracy of 100% was reported in 18 cases (Femur: 14 and tibia: 4) and consolidation was achieved in 22/25 cases with the PRECICE nail in situ. Complications were recorded in 9 (36%) cases (6/20 femur, 3/5 tibia), mainly related to the consolidation process (5/9). The median EQ-5D and EQ-VAS were 0.79 (IQR: 0.63 to 0.79) and 80.0 (IQR: 50.0 to 90.0), respectively.

CONCLUSIONS

The results of this study demonstrated that the PRECICE nail is an effective device for the management of posttraumatic LLD during the treatment of nonunion or malunion bone defects of femur and tibia, offering a reasonable quality of life, despite its postoperative complication risk.

A Novel Electromechanical Intramedullary Nail System for Limb Lengthening

Background/Purpose of the Study

Many methods have been developed to treat leg length discrepancies. Extensible intramedullary nails are the most commonly used systems. However, complications such as excessive distraction, blockage of the nail, aditional surgery, uncontrolled lengthening and much pain occur during the use of these systems, and the desired success rate cannot be achieved. This study aims to develop a new extensible intramedullary system with two mechanisms (electronical and mechanical) for femur and tibia that treats leg length inequalities in a way that allows lengthening without complications as much as possible and does not require a second surgical intervention. It was planned to perform basic mechanical and cadaver functional tests of the new system, which will be designed and developed for this purpose.

Methods

The 3D design of the system has been completed with 3D computer software. A compact system has been developed that is mechanically activated by sudden axial loading and electronically activated by a controllable electric motor. Basic mechanical and functional tests of the new system have been performed within a cadaver.

Results

The rapid prototype of the system with electronical and mechanical units has been produced. As a result of the mechanical tests (axial loading), the nail was found to be resistant to compression forces. Its application to the cadaver and function tests was successfully performed.

Conclusions

We believe that the system we have developed will have advantages, such as working principle, ease of application, controlled lengthening, patient mobility compared to existing leg lengthening methods. The success of the system in practice will be evaluated by in-vivo animal experiments after more detailed mechanical experiments on cadavers. According to the results, it will be ready for human use by performing necessary restorations.

Osmotic pump with potential for bone lengthening distracts continuously in vitro and in vivo

BACKGROUND

In pediatric orthopedics, long bone lengthening procedures are routinely performed using manual, motorized or magnetically controlled implants. This study aims to prove expansion of a newly designed osmotic pump prior to long bone lengthening in living organisms and to rule out any complications related to in vivo conditions, such as congestion of the semipermeable membrane, local infection, or lack of water to drive the osmotic pump, as well as to compare in vivo and in vitro expansion data.

METHODS

Osmotic pumps, which were designed to distract a plate osteosynthesis, were inserted in the dorsal paraspinal musculature of four piglets. To compare the performance of the pumps in in vivo and in vitro conditions, another set of pumps was submerged in physiologic saline solution at different temperatures. The lengthening progress was measured radiographically and sonographically in the study animals.

RESULTS

Both, in vitro and in vivo tested osmotic pumps started distraction after an intended rest phase of four days and distracted evenly over the following twelve days. No complications, clogging or damages occurred. However, we observed a temperature dependency of the distraction rate ranging from 0.98 mm/day at 39°C to 1.10 mm/day at 42°C. With a second setup, we confirmed that the distraction rate differed by 72% within a measured temperature interval of 14° C.

CONCLUSIONS

The data presented here confirm that the novel osmotic pump showed comparable lengthening characteristics in vivo and in vitro. No complications, such as congestion of the semipermeable membrane, local infection, or lack of water to drive the osmotic pump were observed. Thus, osmotic pumps may have great potential in future applications such as long bone lengthening procedures, where continuous distraction probably provides a better bone quality than intermittent lengthening procedures. The fact that one pump failed to elongate in each condition, highlights the importance of technical improvement, but also demonstrates that this was not due to different circumstances within the in vivo or in vitro condition.

Deformity correction and limb lengthening with externally controlled motorized extendable intramedullary nails: Comparison of 2 different nails

OBJECTIVE

The aim of this study was to assess and compare the clinical, radiological, and functional results of patients treated with FITBONE or PRECICE nails due to deformity and length discrepancy in their lower extremities.

METHODS

This retrospective cohort study included 41 patients with length discrepancy and deformity in their lower extremities, who underwent limb lengthening surgery with either FITBONE (group F) or PRECICE (group P) nails between 2010 and 2020. The mean postoperative follow-up period was 15.95 ± 4.75 months in group F (20 patients) and 20.48 ± 7.57 months in group P (21 patients). Lower extremity mechanical and anatomical axes were measured on x-rays preoperatively and at the end of treatment. Consolidation and distraction indexes were also calculated to assess bone healing. Lower Extremity Functional Scale test was used to evaluate functional outcomes and quality of life.

RESULTS

Neither of the treatment methods caused deviations in the mechanical axes and femoral distal angles (P > .05). No statistically significant difference in consolidation and distraction indexes was found between the groups (P > .05). Postoperative complications were seen in 3 of the patients in group F and 4 of the patients from group P. There was no significant difference in Lower Extremity Functional Scale scores between groups (P = .425).

CONCLUSION

This study has demonstrated that treatment with both the FITBONE and PRECICE nails resulted in improved physical and emotional functional outcomes. Both nails had similar radiographic results, complication rates, high patient compliance, and good cosmesis.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Precice Stryde® Magnetic Internal Lengthening Nail does not Impair Bone Healing Despite Radiographic and Clinical Symptoms

Aims

The Precice Stryde® internal magnetic lengthening nail allowed many patients a full weight-bearing experience during femur and tibia lengthening, but concerns over corrosion, pain and radiographic changes led to the implant's recall. Despite the recall, it is important to understand the rate of these occurrences and their influence on the overall success of the lengthening procedure. We aimed to investigate radiographic changes, patient-reported symptoms and bone healing indices for our cohort of Stryde lengthening.

Materials and methods

Our surgical database and electronic medical record system were used to review and document patient demographics, indications for lengthening, length achieved, bone healing index (BHI), location and type of radiographic changes, time until radiographic changes were first visible, presence of pain symptoms (not attributable to surgery or distraction), time to implant removal and if the pain symptoms resolved following implant extraction.

Results

From January 2019 to February 2021, 90 Stryde nails (78 femur and 12 tibia) were implanted in 63 patients. The cohort included 48 males and 15 females. The average length [± standard deviation (SD)] achieved was 58.4 ± 22.7 mm. The 66 bones (73%) developed radiographic changes and were found to be 58/78 (74%) femurs and 8/12 (67%) tibias. The average time to initial radiographic changes was 168 ± 108.1 days (femur) and 276 ± 126.8 days (tibia). Late-onset pain developed in 10 femur lengthening (11.1% of all nails) surgeries across eight patients (12.7% of all patients). All patients' pain resolved; three instances prior to nail removal and the remaining seven after nail removal. No patients were re-presented with worsening pain or radiographic changes following implant removal. Radiographic or symptomatic abnormalities did not impair bone formation. The BHI for femurs with (29.6 ± 16.6 days/cm, n = 58) vs without (29.4 ± 17.9 days/cm, n = 20) radiographic or symptomatic irregularity were nearly identical (p = 0.961). The difference between BHI for tibias with (39.3 ± 7.8 days/cm, n = 8) vs without (86.1 ± 38.2 days/cm, n = 4) radiographic changes was influenced by outliers and underpowered to draw a conclusion.

Conclusion

Bone lengthening with the Stryde nail was associated with high rates of radiographic abnormalities, but symptoms were uncommon and resolved with explantation. The radiographic changes did not affect bone healing in the femur.

Clinical significance

Radiographic changes including bone hypertrophy and osteolysis were common after bone lengthening with the Stryde nail, but the development of pain following consolidation was rare and resolved with implant removal.The BHI in femurs was not affected by radiographic changes.

How to cite this article

Reif TJ, Geffner A, Hoellwarth JS, et al. Precice Stryde® Magnetic Internal Lengthening Nail does not Impair Bone Healing Despite Radiographic and Clinical Symptoms. Strategies Trauma Limb Reconstr 2023;18(2):94-99.

Complications and risk factors of intramedullary bone lengthening nails: a retrospective multicenter cohort study of 314 FITBONE and PRECICE nails

BACKGROUND AND PURPOSE

Intramedullary bone-lengthening nails have become increasingly popular. The 2 most used and successful nails are the FITBONE and the PRECICE nails. Uniform reporting is lacking on complications of intramedullary bone-lengthening nails. The purpose was therefore to assess and categorize the complications of lower limb bone-lengthening nails and investigate risk factors.

PATIENTS AND METHODS

We performed a retrospective review of patients operated on with intramedullary lengthening nails at 2 hospitals. We included only lower limb lengthening with FITBONE and PRECICE nails. Recorded patient data was patient demographics, nail information, and any complication. Complications were graded according to severity and origin classification. Complication risk factors were assessed with modified Poisson regression.

RESULTS

314 segments in 257 patients were included. The FITBONE nail was predominantly used (75%), and most of the lengthenings were performed in the femur (80%). 53% of the patients had complications. 269 complications were identified in 175 segments (144 patients). Device-related complications were most frequent (0.3 complications/segment), followed by joint complications (0.2 complications/segment). An increased relative risk was found for complications in the tibia compared with the femur and for age groups above 30 years compared with the 10-19 years group.

CONCLUSION

Complications with intramedullary bone lengthening nails were more frequent than has previously been reported, with 53% of patients sustaining a complication. Future studies need to document the complications meticulously so that the true risk can be established.

Mechanical Failures in Magnetic Intramedullary Lengthening Nails

BACKGROUND

Magnetic intramedullary lengthening nails (MILNs) have gained popularity in recent years for the treatment of limb-lengthening discrepancies. We sought to catalog mechanical failures and their prevention and management in a large, single-institution series. We specifically assessed the rate of mechanical failures, the types of failures observed, and management strategies.

METHODS

We retrospectively reviewed 377 patients (420 limbs) who underwent limb lengthening with early (P1) or later (P2) MILN iterations with ≥12-month follow-up. Mechanical failure was defined as mechanical breakage of the instrumentation or nail and/or failure of the internal lengthening mechanism. Failure assessment was arranged by lengthening phases and was sorted with a complication classification system. All lengthening and alignment parameters were assessed radiographically.

RESULTS

Mechanical failure was observed in 40 nails (9.5%), most of which (63%) were corrected with an additional surgical procedure. The mechanical failure rate was 11.3% in P1 nails and 9% in P2 nails. Two nails failed the intraoperative distraction test, and 1 nail was found to have a broken washer during the insertion phase. Sixteen nails had mechanical failures in the lengthening phase. Some nails (8 of 16) required nail replacement surgery. Thirteen nails failed during the consolidation phase; 7 of these cases were managed by replacement with either a functional MILN or a conventional intramedullary nail. Eight failures happened during the extraction phase and were managed intraoperatively.

CONCLUSIONS

A 9.5% overall rate of mechanical failure of MILNs was observed in this large series. Resolution was achieved with an additional surgery in most cases. Nail distraction and weight-bearing compliance should be closely monitored during the lengthening and consolidation phases. Nail removal can be difficult and requires a careful study of radiographs for locking-screw bone overgrowth and backup removal equipment.

LEVEL OF EVIDENCE

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

A clinical and radiological matched-pair analysis of patients treated with the PRECICE and STRYDE magnetically driven motorized intramedullary lengthening nails

AIMS

Distraction osteogenesis with intramedullary lengthening devices has undergone rapid development in the past decade with implant enhancement. In this first single-centre matched-pair analysis we focus on the comparison of treatment with the PRECICE and STRYDE intramedullary lengthening devices and aim to clarify any clinical and radiological differences.

METHODS

A single-centre 2:1 matched-pair retrospective analysis of 42 patients treated with the STRYDE and 82 patients treated with the PRECICE nail between May 2013 and November 2020 was conducted. Clinical and lengthening parameters were compared while focusing radiological assessment on osseous alterations related to the nail's telescopic junction and locking bolts at four different stages.

RESULTS

Osteolysis next to the telescopic junction was observed in 31/48 segments (65%) lengthened with the STRYDE nail before implant removal compared to 1/91 segment (1%) in the PRECICE cohort. In the STRYDE cohort, osteolysis initially increased, but decreased or resolved in almost all lengthened segments (86%) after implant removal. Implant failure was observed in 9/48 STRYDE (19%) and in 8/92 PRECICE nails (9%). Breakage of the distal locking bolts was found in 5/48 STRYDE nails (10%) compared to none in the PRECICE cohort. Treatment-associated pain was generally recorded as mild and found in 30/48 patients (63%) and 39/92 (42%) in the STRYDE and PRECICE cohorts, respectively. Temporary range of motion (ROM) limitations under distraction were registered in 17/48 (35%) segments treated with the STRYDE and 35/92 segments (38%) treated with the PRECICE nail.

CONCLUSION

Osteolysis and periosteal reaction, implant breakage, and pain during lengthening and consolidation is more likely in patients treated with the STRYDE nail compared to the PRECICE nail. Temporary ROM limitations during lengthening occurred independent of the applied device. Implant-related osseous alterations seem to remodel after implant removal.Cite this article: Bone Joint J 2023;105-B(1):88-96.

No osteolysis at the telescopic junction of 128 FITBONE lengthening nails

BACKGROUND

Motorized lengthening nails are the treatment standard for bone lengthening of the lower limbs. However, bony changes namely osteolysis and periosteal hypertrophy have been described after certain type of magnetically driven lengthening nails. The aim of this study was to estimate the proportion rate of radiological bone abnormalities of Fitbone TAA femoral or tibial lengthening nails with a minimum follow-up time of 1 year.

HYPOTHESIS

The bone surrounding the telescopic junction of Fitbone lengthening nails does not exhibit osteolysis or periosteal reactions. The bone surrounding the locking screws exhibits cortical hypertrophy.

PATIENTS AND METHODS

Single-centre retrospective case series of patients treated with a Fitbone nails with a minimum follow-up of 1 year after implantation. Standard orthogonal radiographs were obtained postoperatively, weekly during the distraction phase, and then monthly for 6 months, and before removal of the equipment. We looked for bone abnormalities at the telescoping junction of the nail and at the locking screws before removal.

RESULTS

In total, 101 patients (58 males, 43 females) with a mean age of 21 years (range: 11.8-53.5) had 128 (101 femoral and 27 tibial) limb lengthening nails implanted between 2010 and 2021. The mean follow-up period was 925 days (range: 371-3587). The mean lengthening was 4.7cm (range: 1.5-8.0). No bones exhibited focal osteolysis or periosteal reactions at the telescopic junction of the lengthening nail. Cortical hypertrophy at the locking screws was observed in significantly more Fitbone nails than previously reported, i.e., 101/128 (79%).

DISCUSSION

Neither focal osteolysis, nor periosteal reactions were observed at the bone surrounding the telescopic junction of 128 Fitbone lengthening nails. Cortical hypertrophy around the single diaphyseal locking screw was observed in 101/128 (79%) of the cases. These absences of osteolytic changes after long term observation are reassuring for both surgeons and patients alike.

LEVEL OF EVIDENCE

IV.

An update on the intramedullary implant in limb lengthening: A quinquennial review Part 1: The further influence of the intramedullary nail in limb lengthening

The goal of limb lengthening is to restore length to bone, safely stretch soft tissues and improve quality of life with minimal complications. Traditionally this was achieved with the use of external fixators, associated with complications related to pin site tethering and infections, joint stiffness and regenerate deformity and fracture following frame removal. The duration of treatment also impacts on patient mental health and well-being. In order to reduce external fixator time, intramedullary nails have been introduced as an adjunct, either at the initial surgery or after completion of lengthening. Complications related to the external fixator still remained and innovation has led to the popularisation of the intramedullary lengthening nail. The lengthening mechanism of the nail can be divided into those with ratchet systems and those driven by motors. In the ratchet group, patients are required to manually rotate their limb, with movement at the osteotomy site, in order to create forward movement. This was often associated with pain, and in some cases led to the requirement of general anaesthesia to enable rotation and continuation of lengthening. Further issues were reported related to lengthening rate control. Once the nail had lengthened sufficiently for the osteotomy to disengage, rapid lengthening termed a 'runaway' nail could occur. The nails were limited to forward movement, and once length was gained it could not be retracted, leading to poor regenerate formation and soft tissue contractures. The introduction of the Fitbone implant utilised a transcutaneous electrical conduit, powered by a high frequency electrical signal, enabling more control over the lengthening. The Precice intramedullary lengthening system is controlled by the use of an external device with two rotating neodymium magnets, which produce rotation of a third magnet in the nail. By altering the direction of the magnet rotation, the lengthening can be controlled both forwards and backwards with sub-millimetre precision. Following initial excellent outcomes published, the use of the lengthening intramedullary nail has become accepted by many as the implant of choice in limb lengthening. The aim of this article comes in two parts. The first to highlight the latest research and clinical results in the last five years using an intramedullary implant during limb lengthening, and the second to report the outcome in extended surgical indications and further implant innovation.

Correction of post-traumatic lower-limb discrepancy with Precice intramedullary lengthening nails: a review of 34 adults with an average follow-up of 2 years

BACKGROUND AND PURPOSE

We report results and complications of gradual bone lengthening for post-traumatic lower-limb length discrepancy (LLD) with Precice intramedullary lengthening nails in 34 adults.

PATIENTS AND METHODS

Inclusion criteria were lower-limb lengthening using the Precice nail, posttraumatic etiology, age older than 18 years, and minimum follow-up of 12 months after implantation. 34 patients met the inclusion criteria. Radiological and clinical outcome data were collected.

RESULTS

Precice lengthening was performed in the femur in 28 patients (21 antegrade, 7 retrograde) and in the tibia in 6. Mean patient age at time of surgery was 32 years (18-72). Mean preoperative LLD was 31 mm (20-71). Acute correction of axial or rotational malalignment was performed in 11 segments. At final follow-up (mean 2 years [1.1-3.6]), 33 of 34 nails had been removed. All lengthening sites were healed, and all patients mobilized with full weight-bearing. 14 adverse events occurred in 11 patients and were categorized as problems (n = 5), obstacles (n = 3), and complications (n = 6). Unplanned surgery was necessary in 7 patients, 3 of whom did not complete treatment with Precice.

INTERPRETATION

Correction of posttraumatic LLD with or without axial malalignment using Precice intramedullary lengthening nails is associated with a low number of complications and good functional outcome. However, one-fifth of patients in this series needed further unplanned surgery for revision of obstacles or complications.

Humerus Lengthening with a Motorized Intramedullary Nail: A Systematic Review of Outcomes and Complications

Aim

In the past decade, internal limb lengthening nails have gained popularity. In this study, we aim to systematically review the literature on humerus limb lengthening with a motorized intramedullary nail (MIN). We intend to assess the outcome and complications of this technique.

Materials and methods

A systematic review was performed in the following databases: PubMed, Embase, Web of Science, and the Journal of Limb Lengthening and Reconstruction. The inclusion criteria included limb lengthening of the humerus using an intramedullary nail, clinical studies, all levels of evidence, and no restriction to the date of publication.

Results

Our search yielded 239 journal articles. A total of nine articles remained relevant based on the inclusion and exclusion criteria. The total number of patients was 20, with 22 segments lengthened. The mean age of the patients was 20.8-year-old [standard deviation (SD), 12.0; range, 13-51]. The mean gained length was 5.7 cm (SD, 0.9; range, 5-7.5) with a mean distraction protocol of 0.82 mm/day (SD, 0.2; range, 0.6-1). The average duration of lengthening was 71.6 days (SD, 12.8; range, 50-93), and the mean duration of consolidation was 192.3 days (SD, 40.5; range, 120-228). Reported complications included a range of motion (ROM) limitation, hardware failure, and hypertrophic bone regeneration.

Conclusion

Humeral lengthening with an MIN provides favourable outcomes with low complication rates. Future high-level studies should focus on comparing long-term outcomes of humeral lengthening utilising internal and external fixation techniques.

Clinical significance

Humeral lengthening using MIN can be used safely. Each surgical approach and type of nail have different risks and benefits. These should be carefully discussed when planning the surgery.

How to cite this article

Lorange JP, Alamiri N, Marwan Y, et al. Humerus Lengthening with a Motorized Intramedullary Nail: A Systematic Review of Outcomes and Complications. Strategies Trauma Limb Reconstr 2022;17(3):165-171.

Do Surgeons Agree on Severity and Origin of Complications in Bone-lengthening Nails? An Inter- and Intra-rater Reliability Study

Background

Bone-lengthening nails result in various complications with different severity and origin. However, no universal reporting system for complications has been agreed upon, making it difficult to compare different nail designs and patient populations. This study aimed to assess the inter- and intra-rater agreement of a classification system of complications according to severity and origin.

Materials and methods

Four orthopaedic surgeons assessed 48 complications retrieved from patient charts in a single-centre cohort and 49 literature complications cases. Complications were classified according to severity grading (I, II, IIIA and IIIB) from Black et al. and origin with eight main types and 33 subtypes. A blinded independent assessment was performed twice at least six weeks apart. Cohen/Congers kappa estimated for the inter- and intra-rater agreement was interpreted after Svanholm et al.

Results

The surgeons had a good inter-rater agreement for complication severity with a kappa value of 0.68 [95% confidence interval (CI): 0.56-0.79] and complication origin with a kappa value of 0.63 (CI: 0.53-0.73), respectively, on the cohort cases. In literature cases, a good agreement on complication severity and origin grading was shown by kappa values of 0.64 (CI: 0.53-0.75) and 0.74 (CI: 0.65-0.83). The intra-rater assessment of complication severity and origin grading had good to excellent agreement with kappa values ranging from 0.51 to 0.97.

Conclusion and clinical significance

The study presents the first structured complication classification on severity and origin in intramedullary bone-lengthening nails. A good reproducibility agreement in both severity and origin was found between four orthopaedic surgeons for both cohort and literature complication cases. For clinical and research purposes, a shared language for communicating complications is essential. We encourage future studies to use a structured and validated complication classification.

How to cite this article

Frost MW, Rahbek O, Fridberg M, et al. Do Surgeons Agree on Severity and Origin of Complications in Bone-lengthening Nails? An Inter- and Intra-rater Reliability Study. Strategies Trauma Limb Reconstr 2022;17(3):153-158.

Use of the PRECICE Nail for distraction osteogenesis after tumor resection

INTRODUCTION

Reconstructing long bone defects following intercalary tumor resection presents an exciting challenge with a greater range of surgical solutions than more typical situations requiring arthroplasty. Segmental bone transport (distraction osteogenesis) is the least utilized option for intercalary reconstruction, however, it arguably provides patients with the most desirable result. Distraction osteogenesis can be used in the management of multiple skeletal conditions including deformity (either congenital or acquired), or in the presence of bone defects (by trauma or planned surgical excision). Lack of broader adoption of transport is likely due to the highly technical demands and common complications of utilizing fine-wire fixators via the Ilizarov method. More recently, internal lengthening nails such as the PRECICE nail have been employed to facilitate distraction osteogenesis without the added complexity of external fixation.

AREAS COVERED

This review will examine the literature on the indications, design, and safety of the PRECICE nail (NuVasive) for intercalary reconstruction after tumor resection.

EXPERT OPINION

Bone transport using the PRECICE nail represents a viable alternative to Ilizarov distraction and has the benefit of avoiding the complications of an external fixator. For large defects, the PRECICE nail can be supplemented with a locking plate for additional stability and maintenance of limb length.

What Are the Potential Benefits and Risks of Using Magnetically Driven Antegrade Intramedullary Lengthening Nails for Femoral Lengthening to Treat Leg Length Discrepancy?

BACKGROUND

Limb lengthening with magnetically driven intramedullary lengthening nails is a fast-developing field and represents an alternative to external fixators. Although previous studies have assessed the application of magnetically driven intramedullary lengthening nails, these studies have been heterogenous regarding the nailing approach, the bone treated, and the implant type; they also have analyzed relatively small patient groups at short follow-up durations.

QUESTIONS/PURPOSES

(1) Is femoral lengthening with magnetically driven antegrade intramedullary lengthening nails accurate and precise? (2) What are the most common complications of treatment? (3) What factors are associated with unplanned additional surgery?

METHODS

We retrospectively analyzed the longitudinally maintained database of our orthopaedic teaching hospital to identify all patients who underwent surgery for leg length discrepancy (LLD) between October 2014 and April 2019. In total, we surgically treated 323 patients for LLD of 2 cm or more. Of those 55% (177 of 323) were treated with distraction osteogenesis with magnetically driven intramedullary lengthening nails, 18% (59 of 323) with external fixation, and 27% (87 of 323) with epiphysiodesis around the knee. Based on that, 29% (93 of 323) of patients underwent unilateral femoral distraction osteogenesis with magnetically driven antegrade femoral lengthening nails and were eligible for analysis. No patient was excluded, and 3% (3 of 93) were lost before the minimum study follow-up of 2 years, leaving 97% (90 of 93) for analysis. Patients with a distal femoral deformity were treated via a retrograde femoral approach (10% [33 of 323]) or with external fixators (3% [10 of 323]) and were not included in this study. Distraction osteogenesis with magnetically driven intramedullary lengthening nails was not considered for patients with deep tissue infection, those with bone dimensions considered to be too small in relation to the available implants, and for patients younger than 8 years. This study included 90 patients (44 females, 43 left femora) treated for a median (interquartile range) preoperative LLD of 39 mm (32 to 52) at a median age of 15 years (14 to 17). The same limb lengthening system was applied in all patients. The median (IQR) follow-up was 35 months (24 to 78). Data were acquired through a chart review performed by someone not involved in the surgical care of the included patients. Data acquisition was supervised and curated by two of the involved surgeons. Accuracy was calculated as 100 - [(achieved distraction in mm - planned distraction in mm) / (planned distraction in mm) x 100] and precision as 100 - (relative standard deviation of accuracy). Treatment-associated complications were summarized descriptively and characterized as complications resulting in unplanned additional surgery or those not resulting in unplanned surgery. To analyze the risk of unplanned additional surgery by entity, we calculated odds ratios (ORs) comparing the incidence of unplanned additional surgery in the different entity cohorts with the idiopathic LLD cohort as a reference. By calculating ORs, we analyzed the risk for unplanned additional surgery depending on sex, age, surgery time, and previous lengthening. Due to the lack of long-term evidence about motorized lengthening nails remaining in situ and concerns about potential implant-related adverse effects, removal was routinely scheduled 1 year after consolidation. For implant removal, 92% (83 of 90) of patients underwent planned additional surgery, which was not recorded as an adverse event of the treatment. Ninety-seven percent (87 of 90) of patients completed lengthening with the implant remaining in situ until the end of distraction. The median (IQR) distraction length was 37 mm (30 to 45) with a median distraction index of 0.9 mm/day (0.7 to 1.0) and median consolidation index of 31 days/cm (25 to 42).

RESULTS

The calculated accuracy and precision were 94% and 90%, respectively. In total, 76% (68 of 90) of our patients experienced complications, which resulted in 20% (18 of 90) of patients undergoing unplanned additional surgery. The most common complication overall was adjustment of the distraction rate in 27% (24 of 90) of patients (faster: 16% [14 of 90]; slower: 11% [10 of 90]) and temporary restriction of knee motion, which occurred in 20% (18 of 90) of our patients and resolved in all patients who experienced it. The most serious complications were bacterial osteomyelitis and knee subluxation, which occurred in 3% (3 of 90) and 1% (1 of 90) of our patients, respectively. With the numbers available, we found only one factor associated with an increased likelihood of unplanned additional surgery: Patients with postinfectious LLD had higher odds of unplanned additional surgery than patients with idiopathic LLD (7% [1 of 15] versus 50% [3 of 6], OR 14.0 [95% CI 1.06 to 185.49]; p = 0.02). However, we caution readers this finding is fragile, and the confidence interval suggests that the effect size estimate is likely to be imprecise.

CONCLUSION

Femoral distraction osteogenesis with magnetically driven antegrade intramedullary lengthening nails appears to be an accurate and reliable treatment for femoral lengthening. However, depending on the etiology, a high risk of unplanned additional surgery should be anticipated, and a high proportion of patients will experience temporary joint stiffness. We recommend close orthopaedic follow-up and physiotherapy during treatment. This treatment of LLD can be considered alongside other nails, external fixators, and epiphysiodesis. Multicenter studies comparing this with other approaches are needed.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Limb Lengthening With Precice Intramedullary Lengthening Nails in Children and Adolescents

BACKGROUND

The Precice intramedullary bone lengthening nail has been used in our department since 2013. We sought to determine the efficacy and safety of intramedullary limb lengthening with Precice nails in children and adolescents.

METHODS

We retrospectively investigated patients 18 years and younger who underwent lower-limb lengthening using the Precice nail. Radiologic and clinical outcome data were obtained from a prospective database. The minimum postimplantation follow-up was 12 months. Between March 2013 and March 2020, 161 patients underwent limb lengthening with a Precice nail; 76 patients met the inclusion criteria.

RESULTS

We used 84 nails in 76 patients (68 femurs and 16 tibias). Femoral nails were inserted using an antegrade approach in 57 patients and a retrograde approach in 11. The mean age at surgery was 16 years (range, 9 to 18 y). The mean lengthening was 33 mm (range, 14 to 80 mm) with additional acute axial or rotational malalignment correction in 16 segments. At the last follow-up (mean=2.1, years; range, 1 to 5 y), all regenerates had healed and all patients were mobile with full weight-bearing. Complications that necessitated surgical revision occurred in 6 patients (8%), and the desired lengthening was not achieved in 2 patients. Postlengthening malalignment occurred in 4 patients (5 tibial nails). The weight-bearing index, defined as days from surgery to full weight-bearing/cm of lengthening, was a mean of 45 days (range, 7 to 127 d/cm).

CONCLUSIONS

The Precice nail facilitated reliable and safe bone lengthening and was associated with a low complication rate. Correction of additional malalignment was possible by applying intraoperative acute correction or guided growth.

LEVEL OF EVIDENCE

Level IV-therapeutic study investigating the results of treatment.

Limb reconstruction in a resource-limited environment

INTRODUCTION

Limb salvage and reconstruction are often challenging and even more so in the limited resource setting. The purpose of this narrative review is to explore the strategies for addressing the unique obstacles and opportunities of limb reconstructive surgery in resource-limited environments globally.

METHODS

We review (1) the global burden and dimension of the problem, (2) the relevance of orthopedic forums and communication, (3) free and open-access software for deformity analysis and correction, (4) bidirectional learning opportunities, and the value of fellowships and mentoring between resource-rich and resource-limited countries, and (5) how societies like SICOT can help to tackle the problem. Finally, case examples are presented to demonstrate the choice of surgical implants, their availability in regions with limited resources, and how the universal principles of limb reconstruction can be applied, irrespective of resource availability.

RESULTS

Limb reconstruction can often be life-changing surgery with the goals of limb salvage, improved function, and ambulation. The contradiction of relatively few severe limb deformities in high-income countries (HICs) with abundant resources and the considerable burden of limb deformities in resource-limited countries is striking. Free, open access to education and software planning tools are of paramount importance to achieve this goal of limb reconstruction. Bidirectional learning, i.e., knowledge exchange between individual surgeons and societies with limited and abundant resources, can be reached via fellowships and mentoring. The presented cases highlight (1) fixator-assisted wound closure obliviating the need for plastic surgery, (2) open bone transport, and (3) hinged Ilizarov frames for correction of severe deformities. These cases underline that optimal clinical outcome can be achieved with low-cost and readily available implants when the principles of limb reconstruction are skillfully applied.

DISCUSSION

Limb lengthening and reconstruction are based on universally applicable principles. These have to be applied regardless of the planning tool or surgical implant availability to achieve the goals of limb salvage and improved quality of life.

Removal of broken PRECICE Stryde intramedullary lengthening nails

This paper describes two different techniques for removal of broken Precice Stryde intramedullary bone lengthening nails, which unlike trauma nails are solid containing mechanical components. Consequently, surgeons face unique challenges when these implants brake within medullary canal. Here, we present our surgical approach for removal of three broken implants. In one patient (46kg) both Ø10mm femoral Stryde implants (max. weight allowance 68kg) broke through the proximal locking screw hole preoperatively on the right side and intraoperatively on the left side (413 and 504 days after index surgery respectively). The third Ø11.5 femoral nail broke through the area containing the magnet (55kg patient, 325 days after index surgery). LEVEL OF EVIDENCE: IV.

Complications in Elective Removal of 271 Bone Lengthening Nails (FITBONE, PRECICE and STRYDE)

Background

Intramedullary lengthening nails have shown excellent short-term results. The FITBONE and the PRECICE nail are the two most commonly used intramedullary lengthening nails. The manufacturer of each nail recommends the removal of the implant after the completion of the treatment. Despite the need for removal of each nail, the authors are not aware of any prior publications documenting the results of standard intramedullary lengthening nail removal. Therefore, the aim of this study was to examine the intraoperative and postoperative complications of elective intramedullary lengthening nail removals.

Materials and methods

We performed a retrospective chart review of patients operated with intramedullary lengthening nails at two limb reconstruction centres (one in the United States, and the second in Denmark). Data retrieved from the patient charts included patient demographics, nail information and any complications occurring at or after nail removal. Only lower limb lengthening with FITBONE and PRECICE or STRYDE nails that had an elective nail removal was included.

Result

A total of 271 elective nail removals were included in the study. Complications occurred during 3% of the nail removals and in 13% after nail removal. There were 18 reported cases with postoperative knee pain. All these patients had nail removal through the knee joint, representing 8% of the retrograde femur nail removals and 7% of the tibia nail removals. Four postoperative fractures occurred, of which two needed surgery. Eleven percent of femur removals and 26% of tibial removals sustained a complication.

Conclusion and clinical significance

This study emphasises the importance of adequate follow-up of the bone lengthening patient even after the nail has been removed. It also shows that the recommended removal of the intramedullary nail (IMN) lengthening nails must be included in studies reporting on the overall risks of complications using bone lengthening nails.

How to cite this article

Frost MW, Kold S, Rahbek O, et al. Complications in Elective Removal of 271 Bone Lengthening Nails (FITBONE, PRECICE and STRYDE). Strategies Trauma Limb Reconstr 2021;16(2):110-115.

Plate-Tensioned-Nail for Salvage of Failed Subtrochanteric Intramedullary Motorized Limb Lengthening: A Case Report

CASE

A 43-year-old insulin-dependent man with a 4.4-cm posttraumatic femoral limb length discrepancy sustained a subtrochanteric femur fracture associated with failure of a motorized intramedullary limb lengthening nail during distraction osteogenesis. The patient requested a single-stage salvage operation. After implant removal, the femur was stabilized and compressed with a plate-tensioned-nail construct consisting of 4.5-mm locking compression plate tensioned and linked to a femoral reconstruction nail through interlocking screws with immediate weight-bearing.

CONCLUSION

A plate-tensioned-nail construct is a single-stage salvage option for a length-unstable subtrochanteric nonunion which permits immediate full weight-bearing.

The STRYDE limb lengthening nail is susceptible to mechanically assisted crevice corrosion: an analysis of 23 retrieved implants

Background and purpose - We noted several adverse events in patients in whom the first version of the STRYDE limb-lengthening nail (NuVasive Specialized Orthopaedics, San Diego, CA) had been implanted. Pain, osteolysis, periosteal reactions, and cortical hypertrophy at the nail junction were noted. Here, we present the analysis of 23 retrieved STRYDE implants.Materials and methods - We undertook visual inspection of the retrieved nails and screws, mechanical evaluation of the junction, micro-CT analyses, microscopic inspection of the bushing, screws, screw holes, and separated parts of the implants. Positive material identification (PMI) and energy-dispersive X-ray spectroscopy (EDS) were used to analyze the chemical composition. The hardness of the material was also investigated.Results - 20/23 retrieved nails had visible signs of corrosion, i.e., discoloration at the telescopic junction. Micro-CT verified corrosion attacks in 12/12 scanned bushings. Corrosion, predominantly mechanically assisted crevice corrosion, was observed at the locking screws and screw holes in 20/23 nails. Biological material inside the nail was observed in addition to oozing from the junction of 2 nails during hardware removal, which was experimentally reproducible. Notably, the mechanical construction of the bushing changed from PRECICE P2 to STRYDE nails.Interpretation - STRYDE nails are not hermetically sealed, and liquid can pass the bushing. Biodur 108 itself is corrosion resistant; however, mechanically assisted crevice corrosion of the bushing, locking screws, and screw holes may be aggravated due to manufacturing aiming for increased strength and hardness of the alloy.Observing several adverse events, we recently published a nationwide cross-sectional analysis of all 30 STRYDE limb- lengthening nails (NuVasive, Specialized Orthopedics, San Diego, CA) that were implanted in Denmark (Rölfing et al. 2021a). 27/30 STRYDE nails have now been removed and we present data from metallurgical analysis of 23 of the retrieved implants.

Radiographs of 366 removed limb-lengthening nails reveal differences in bone abnormalities between different nail types

AIMS

Limb-lengthening nails have largely replaced external fixation in limb-lengthening and reconstructive surgery. However, the adverse events and high prevalence of radiological changes recently noted with the STRYDE lengthening nail have raised concerns about the use of internal lengthening nails. The aim of this study was to compare the prevalence of radiological bone abnormalities between STRYDE, PRECICE, and FITBONE nails prior to nail removal.

METHODS

This was a retrospective case series from three centres. Patients were included if they had either of the three limb-lengthening nails (STYDE, PRECICE, or FITBONE) removed. Standard orthogonal radiographs immediately prior to nail removal were examined for bone abnormalities at the junction of the telescoping nail parts.

RESULTS

In total, 306 patients (168 male, 138 female) had 366 limb-lengthening nails removed. The mean time from nail insertion to radiological evaluation was 434 days (36 to 3,015). Overall, 77% of STRYDE nails (20/26) had bone abnormalities at the interface compared with only 2% of FITBONE (4/242) and 1% of PRECICE nails (1/98; p < 0.001). Focal osteolysis in conjunction with periosteal reaction at the telescoping interface was only observed in STRYDE nails.

CONCLUSION

Bone abnormalities at the interface of telescoping nail parts were seen in the majority of STRYDE nails, but only very rarely with FITBONE or PRECICE nails. We conclude that the low prevalence of radiological changes at the junctional interface of 242 FITBONE and 98 PRECICE nails at the time of nail removal does not warrant clinical concerns. Cite this article: Bone Joint J 2021;103-B(11):1731-1735.

International recognition of the Ilizarov bone reconstruction techniques: Current practice and research (dedicated to 100th birthday of G. A. Ilizarov)

The Ilizarov method is one of the current methods used in bone reconstruction. It originated in the middle of the past century and comprises a number of bone reconstruction techniques executed with a ring external fixator developed by Ilizarov GA. Its main merits are viable new bone formation through distraction osteogenesis, high union rates and functional use of the limb throughout the course of treatment. The study of the phenomenon of distraction osteogenesis induced by tension stress with the Ilizarov apparatus was the impetus for advancement in bone reconstruction surgery. Since then, the original method has been used along with a number of its modifications developed due to emergence of new fixation devices and techniques of their application such as hexapod external fixators and motorized intramedullary lengthening nails. They gave rise to a relatively new orthopedic subspecialty termed "limb lengthening and reconstruction surgery". Based on a comprehensive literature search, we summarized the recent clinical practice and research in bone reconstruction by the Ilizarov method with a special focus on its modification and recognition by the world orthopedic community. The international influence of the Ilizarov method was reviewed in regard to the origin country of the authors and journal's rating. The Ilizarov method and other techniques based on distraction osteogenesis have been used in many countries and on all populated continents. It proves its international significance and confirms the greatest contribution of Ilizarov GA to bone reconstruction surgery.

Complications common in motorized intramedullary bone transport for non-infected segmental defects: a retrospective review of 15 patients

Background and purpose - Since the introduction of intramedullary bone transport nails only very few cases have been reported in the literature. Thus we evaluated the results and complications in a single institution retrospective cohort.Patients and methods - 15 (median age 40 years (18-70), 8 males) consecutive patients, were included and the electronic patient records and radiographs were reviewed. Complications were severity graded and categorized as device or non-device related.Results - The segmental bone loss was due to non-union site in 8 femurs and 4 tibias, or traumatic bone loss in 2 femurs and 1 tibia. The segmental bone defect was a median of 3 cm (0.5-10). 9 of 10 femoral cases and 4 of 5 tibial cases healed with the bone transport nail. All 15 patients had a healed docking site and regenerate at the end of treatment after a median of 13 months (6-38). 24 complications (15 device related and 9 non-device related) occurred in 11/15 patients with a minimum follow-up of 6 months after nail removal. The number of unplanned surgeries due to device related complications was: 0 in 9 patients, 1 in 3 patients, 2 in 1 patient, 3 in 2 patients.Interpretation - Segmental bone defects can heal with a bone transport nail. However, the number of complications was high and 15 out of 24 complications were devicerelated. Optimizing nail design is therefore needed to reduce complications in intramedullary bone transport.

Pain, osteolysis, and periosteal reaction are associated with the STRYDE limb lengthening nail: a nationwide cross-sectional study

Background and purpose - Observing serious adverse events during treatment with the Precice Stryde bone lengthening nail (NuVasive, San Diego, CA, USA), we conducted a nationwide cross-sectional study to report the prevalence of adverse events from all 30 bone segments in 27 patients treated in Denmark.Patients and methods - Radiographs of all bone segments were evaluated regarding radiographic changes in February 2021. We determined the number of bone segments with late onset of pain and/or radiographically confirmed osteolysis, periosteal reaction, or cortical hypertrophy in the junctional area of the nail.Results - In 30 bone segments of 27 patients we observed radiographic changes in 21/30 segments of 20/27 patients, i.e., 19/30 osteolysis, 12/30 periosteal reaction (most often multi-layered), and 12/30 cortical hypertrophy in the area of the junction between the telescoping nail parts. Late onset of pain was a prominent feature in 8 patients. This is likely to be a prodrome to the bony changes. Discoloration (potential corrosion) at the nail interface was observed in multiple removed nails. 15/30 nails were still at risk of developing complications, i.e., were not yet removed.Interpretation - All Stryde nails should be monitored at regular intervals until removal. Onset of pain at late stages of limb lengthening, i.e., consolidation of the regenerate, should warrant immediate radiographic examination regarding osteolysis, periosteal reaction, and cortical hypertrophy, which may be associated with discoloration (potential corrosion) of the nail. We recommend removal of Stryde implants as early as possible after consolidation of the regenerate.

Focal osteolysis and corrosion at the junction of Precice Stryde intramedullary lengthening device : preliminary clinical, radiological, and metallurgic analysis of 57 lengthened segments

Aims

This study aims to enhance understanding of clinical and radiological consequences and involved mechanisms that led to corrosion of the Precice Stryde (Stryde) intramedullary lengthening nail in the post market surveillance era of the device. Between 2018 and 2021 more than 2,000 Stryde nails have been implanted worldwide. However, the outcome of treatment with the Stryde system is insufficiently reported.

Methods

This is a retrospective single-centre study analyzing outcome of 57 consecutive lengthening procedures performed with the Stryde nail at the authors’ institution from February 2019 until November 2020. Macro- and microscopic metallographic analysis of four retrieved nails was conducted. To investigate observed corrosion at telescoping junction, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX) were performed.

Results

Adjacent to the nail’s telescoping junction, osteolytic changes were observed in bi-planar radiographs of 20/57 segments (35%) after a mean of 9.5 months (95% confidence interval 7.2 to 11.9) after surgery. A total of 8/20 patients with osseous alterations (40%) reported rest and ambulation pain of the lengthened segment during consolidation.

So far, 24 Stryde nails were retrieved and in 20 (83%) macroscopic corrosion was observed at the nail’s telescoping junction. Before implant removal 11/20 radiographs (55%) of lengthened segments with these 20 nails revealed osteolysis. Implant retrieval analysis by means of SEM showed pitting and crevice corrosion. EDX detected chromium as the main metallic element of corrosion.

Conclusion

Patients are exposed to the risk of implant-related osteolysis of unclear short- and long-term clinical consequences. The authors advocate in favour of an early implant removal after osseous consolidation.

Cite this article: Bone Joint Res 2021;10(7):425–436.

Bone Lengthening with a Motorized Intramedullary Nail in 34 Patients with Posttraumatic Limb Length Discrepancies

The Fitbone® motorized nail system has been used to correct limb length discrepancies (LLD) for several years. This study focuses on its application in posttraumatic limb lengthening surgery, its outcome and challenges.

MATERIALS AND METHODS

A prospective, single center study was conducted between 2010 and 2019 in patients treated with motorized lengthening nails. The inclusion criteria were symptomatic LLD of 20 mm or more. An imaging analysis was done using TraumaCad® software (Brainlab AG, Munich, Germany) to compare frontal alignment angles and limb length discrepancy (LLD) on preoperative and latest follow-up radiographs of the lower limbs.

RESULTS

Thirty-four patients were included with a mean age of 28.8 ± 9.7 years, a mean follow-up of 27.8 ± 13 months and a mean hospital stay of 4.4 ± 1.7 days. The mean LLD was 44 ± 18 mm in 29 femoral and 32 ± 8 mm in 4 tibial cases, which was reduced to less than 10 mm in 25/34 (74%) patients. The mean healing index was 84.6 ± 62.5 days/cm for femurs and 92 ± 38.6 days/cm for tibias. The mean time to resume full weight-bearing without walking aids was 226 days ± 133. There was no significant difference between preoperative and final follow-up alignment angles and range of motion. The mechanical lateral distal femoral angle (mLDFA) was corrected in the subgroup of 10 LLD patients with varus deformity of the femur (preoperative 95.7° (±5.0) vs. postoperative 91.5° (±3.4), p = 0.008). According to Paley's classification, there were 14 problems, 10 obstacles and 2 complications.

DISCUSSION

Six instances of locking screw pull out, often requiring reoperation, raise the question of whether a more systematic use of blocking screws that provide greater stability might be indicated. Lack of compliance can lead to poor outcomes, patient selection in posttraumatic LLD patients is therefore important.

CONCLUSION

Limb lengthening with a motorized lengthening nail for posttraumatic LLD is a relatively safe and reliable procedure. Full patient compliance is crucial. In-depth knowledge of lengthening and deformity correction techniques is essential to prevent and manage complications.