How precise is the PRECICE compared to the ISKD in intramedullary limb lengthening? Reliability and safety in 26 procedures

Simultaneous correction of leg length discrepancy and angular deformity of the distal femur with retrograde Precice nails: a retrospective analysis of 45 patients

BACKGROUND AND PURPOSE

Magnetically controlled motorized intramedullary lengthening nails (ILNs) can be employed for simultaneous correction of angular deformities of the distal femur and leg length discrepancy. This spares typical complications of external fixators but requires precise preoperative planning and exact intraoperative execution. To date, its results are insufficiently reported. We aimed to elucidate the following questions: (i) Is acute angular deformity correction and gradual femoral lengthening via a retrograde ILN a reliable and precise treatment option? (ii) What are the most common complications of treatment?

METHODS

Acute angular deformity correction and subsequent gradual lengthening of the distal femur with retrograde ILN was retrospectively analyzed in 45 patients (median patient age: 15 years, interquartile range [IQR] 13-19 and median follow-up: 40 months, IQR 31-50). Outcome parameters were accuracy, precision, reliability, bone healing, and complications of treatment.

RESULTS

The median distraction was 46 mm (IQR 29-49), median distraction and consolidation index 0.9 mm/day (IQR 0.7-1.0) and 29 days/cm (IQR 24-43), respectively. The median preoperative mechanical axis deviation (MAD) was 30 mm (IQR 23-39) in the varus cohort and -25 mm (IQR -29 to -15) in the valgus cohort and reduced to a mean of 8 mm (standard deviation [SD] 8) and -3 (SD 10), respectively. Accuracy, precision, and reliability of lengthening were 94%, 95% and 96%, respectively. Accuracy and precision of deformity correction were 92% and 89%, respectively. In total, 40/45 of patients achieved distraction with a difference of less than 1 cm from the initial plan and a postoperative MAD ranging from -10 mm to +15 mm. In 13/45 patients unplanned additional surgeries were conducted to achieve treatment goal with nonunion being the most frequent (4/45) and knee subluxation (3/45) the most severe complication.

CONCLUSION

Acute deformity correction and subsequent lengthening of the distal femur with retrograde ILN is a reliable and accurate treatment achieving treatment goal in 89% but unplanned additional surgeries in 29% of patients should be anticipated.

Outpatient limb lengthening using magnetic intramedullary nails: A single Institution's experience

Introduction

The advantages of outpatient surgery have been shown in other orthopedic subspecialities to be a means of driving down costs and reducing the average length of hospital stay. However, there is a scarcity of literature examining the utility of a specific, hospital-based facility performing such procedures for limb lengthening. Considering this, we aimed to investigate surgical factors, patient characteristics, and the incidence of outpatient postoperative complications for patients undergoing surgery and subsequent distraction osteogenesis utilizing the Precice® nail, a state-of-the-art magnetic intramedullary nail (MILN).

Methods

We performed a retrospective review of medical records pertaining to outpatient limb lengthening procedures occurring between January 2012 and September 2023 at a single institution, as performed by three surgeons. Variables of interest included baseline demographics, type of anesthesia, operative bone, laterality, preoperative diagnosis, osteotomy level, procedure performed, prosthesis, point of entry, nail diameter/length, goal length, goal achieved, postoperative complications, and elective nail removal.

Results

The cohort comprised 20 limbs, with an average age at index surgery of 24.8 (SD 7.96). There were no complications related to the outpatient nature of the procedure. Five of the 20 limbs had postoperative complications, including deep vein thrombosis (DVT), screw backout, and nail breakage.

Conclusion

Our initial investigation of outpatient limb lengthening at a specific, hospital-based facility demonstrated favorable postoperative outcomes for those patients undergoing limb lengthening procedures with an MILN. The field would certainly benefit from future research assessing outcomes of pediatric surgeries in the outpatient setting on a larger scale, as well as across hospital systems, the country, and globally. With the proven advances and benefits of MILNs, prioritizing examination of their efficacy in an outpatient population is imperative. Furthermore, the success of outpatient procedures in other orthopedic subspecialities, such as total joint arthroplasty, is a logical, driving precedent for this rationale.

Lengthening Patients Previously Treated for Massive Lower Limb Reconstruction for Bone Tumors with the PRECICE 2 Nail

The objective of this study was to determine the efficacy of the PRECICE 2® nail in the treatment of lower limb length discrepancy in patients with a history of bone tumors. This study reports on outcomes, complications, and the safety of the PRECICE 2 limb lengthening nail in a cohort of pediatric patients with limb length discrepancy after surgery for bone tumors. Seventeen patients were treated with intramedullary magnetic nails. The average patient age at the time of surgery was 19 (range 11-32). The PRECICE 2 nail was used on 14 femurs (6 retrograde and 8 anterograde) and 3 tibias. The average consolidation time was 141 days (range 50-360) with a mean CI of 31 ± 12 days/cm. The ASAMI bone score showed 14 (82%) excellent results, 1 (6%) good result, and 2 (12%) poor results. The ASAMI functional score showed 13 (84.6%) excellent results, 3 (11.5%) good results, and 1 (3.8%) fair result. Patients treated with chemotherapy for bone cancer did not show any increase in distraction time or consolidation time. A total of 3 (17%) problems, 1 obstacle (5.5%), and 1 complication (5.5%) were encountered in our case series. The PRECICE 2 nail allows for effective and accurate lengthening preserving the range of motion in patients treated for bone tumors.

Current Management of Diaphyseal Long Bone Defects-A Multidisciplinary and International Perspective

The treatment of defects of the long bones remains one of the biggest challenges in trauma and orthopedic surgery. The treatment path is usually very wearing for the patient, the patient's environment and the treating physician. The clinical or regional circumstances, the defect etiology and the patient´s condition and mental status define the treatment path chosen by the treating surgeon. Depending on the patient´s demands, the bony reconstruction has to be taken into consideration at a defect size of 2-3 cm, especially in the lower limbs. Below this defect size, acute shortening or bone grafting is usually preferred. A thorough assessment of the patient´s condition including comorbidities in a multidisciplinary manner and her or his personal demands must be taken into consideration. Several techniques are available to restore continuity of the long bone. In general, these techniques can be divided into repair techniques and reconstructive techniques. The aim of the repair techniques is anatomical restoration of the bone with differentiation of the cortex and marrow. Currently, classic, hybrid or all-internal distraction devices are technical options. However, they are all based on distraction osteogenesis. Reconstructive techniques restore long-bone continuity by replacing the defect zone with autologous bone, e.g., with a vascularized bone graft or with the technique described by Masquelet. Allografts for defect reconstruction in long bones might also be described as possible options. Due to limited access to allografts in many countries and the authors' opinion that allografts result in poorer outcomes, this review focuses on autologous techniques and gives an internationally aligned overview of the current concepts in repair or reconstruction techniques of segmental long-bone defects.

[Options and limits of leg length correction in paediatric orthopaedics]

For paediatric orthopaedic surgeons treating leg length discrepancy, knowledge of the available procedures and their options and limits is just as important as mastery of the very different surgical methods and implants, as well as the possible complications, in order to be able to advise and treat the children and adolescents and their parents comprehensively and in the best interests. Both the growth inhibiting procedures and the complex bone lengthening procedures require a great deal of experience to successfully guide patients and families through what is often a lengthy and sometimes complicated treatment process. Careful preoperative indications and planning, precise surgical techniques with suitable instruments and implants, and attentive postoperative check-ups are mandatory prerequisites for the desired therapeutic success.

Treatment of Angular Deformity and Limb Length Discrepancy With a Retrograde Femur Magnetic Intramedullary Nail: A Fixator-assisted, Blocking Screw Technique

BACKGROUND

Fixator-assisted nailing techniques that incorporate magnetic internal lengthening nails (MILNs) permit acute deformity correction and then gradual limb lengthening without needing postoperative external fixators.

PURPOSES

We sought to investigate the safety and accuracy of a fixator-assisted, blocking screw technique using retrograde MILNs for the correction of LLD and limb malalignment.

METHODS

Forty-one patients (13 patients with genu varum and 28 patients with genu valgum) with LLD treated with fixator-assisted, blocking screw retrograde MILN reconstruction were included. Preoperative LLD, mechanical axis deviation, and joint orientation angles were compared with values at the end of treatment, and bone healing indices were calculated. Perioperative complications were tracked.

RESULTS

Preoperatively, the mean mechanical lateral distal femoral angle of the varus cohort was 98 ± 12°, whereas the mean lateral distal femoral angle of the valgus cohort was 82±4°. Both cohorts had an average 3-cm LLD. 99% of the planned limb lengthening was achieved. Final LDFAs were 91 ± 6° and 89 ± 4° in the varus and valgus cohorts, respectively, and the limb mechanical axis angles were normalized. 10 patients underwent a total of 21 returns to the operating room. Most commonly, this involved percutaneous injection of bone marrow aspirate concentrate to bone regenerate exhibiting delayed union (6 patients).

CONCLUSIONS

The use of a retrograde MILN with a fixator-assisted, blocking screw technique is an effective means of acute deformity correction and gradual limb lengthening through minimal incisions. The accuracy of deformity correction relies on intraoperative execution of the appropriate nail start site, osteotomy location, and placement of blocking screws.

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.

Callus distraction for brachymetatarsia - A comparison between an internal device and the external fixator

BACKGROUND

Symptomatic patients with severe brachymetatarsia are commonly treated with callus distraction using external mini-fixator (EF) or internal device (ID). This study points out advantages and limitations of both methods comparing clinical and radiographical parameters.

METHODS

Retrospective analysis of 21 metatarsal bones in twelve patients. Twelve metatarsals were treated with ID (Genos Mini), nine with EF (MiniRail).

RESULTS

Mean lengthening distance was 17.3 mm using EF and 11.7 mm using ID (p = 0.016). Adverse results were observed in 89% of metatarsals treated with EF and in 33% treated with ID (p = 0.011). Postoperative surgical intervention was required in 33% using EF compared to 0% using ID (p = 0.031). Mean total German Foot Function Index (FFI-T) improved from 49 to 33 using EF and from 47 to 22 using ID (p < 0.001).

CONCLUSION

CD is a reliable surgical treatment for BMT. Surgeons should be aware of implant-related advantages and complications when counseling patients about treatment options.

Unroofing osteotomy for dissociated tibial intramedullary magnetic rod during implant removal: a case report

The PRECICE® intramedullary rod (NuVasive, San Diego, CA) utilizes multiple telescopic components to magnetically drive limb lengthening. These devices are routinely explanted after desired growth correction is met. To the author’s knowledge, this is the first description of an osteotomy assisted extraction of a disassociated tibial magnetic lengthening rod. A 17-year-old girl with fibular hemimelia and resolved left tibial length discrepancy after successful surgical lengthening underwent a complex implant removal approximately seven years after regenerate consolidation. During implant removal, the telescopic portion of the rod remained lodged in the tibial medullary canal and a subsequent unroofing osteotomy of the tibia was performed. Tibial limb length discrepancies are oftentimes corrected with complex implants comprised of multiple fragile components that are routinely explanted. During the unfortunate event of a telescopic intramedullary rod dissociation, an unroofing osteotomy can be successfully performed to removal all implant components.

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.

Current Perspectives on the Management of Bone Fragments in Open Tibial Fractures: New Developments and Future Directions

Open tibial fractures may be associated with bone loss at the time of the injury or following surgical debridement of the fracture. This article discusses the various treatment options available and the latest developments surrounding the management of free bone fragments in open tibial fractures.

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.

Removal of a Broken Stainless-Steel Intramedullary Lengthening Stryde Nail: A Case Report and Review of the Literature

CASE

We report a 15-year-old female patient who underwent femur lengthening with a stainless steel intramedullary lengthening Stryde nail that broke at the end of the lengthening course and required removal. Given the solid noncannulated nature of the nail, this required special strategy to remove broken parts.

CONCLUSION

Stryde nails are stainless steel lengthening nails that were developed to allow more freedom with weight bearing. Regardless of this change, hardware failure remains possible. In addition to maintaining regenerate integrity, a surgeon must be creative when attempting to remove solid nail types because many techniques for removing failed hardware were developed for cannulated devices.

Comparison of Intramedullary Magnetic Nail, Monolateral External Distractor, and Spatial External Fixator in Femur Lengthening in Adolescents with Congenital Diseases

The aim of this study is to evaluate the course of the treatment and clinical and functional outcomes of femur lengthening in adolescents with congenital disorders by the application of different surgical methods. This retrospective study comprised 35 patients (39 procedures). A total of 11 patients underwent femur lengthening with the use of the intramedullary magnetic nail (IMN) Precise 2 (NuVasive, San Diego, CA, USA), 7 patients (11 procedures) with the use of the monolateral external distractor Modular Rail System (MRS) (Smith and Nephew, Memphis, TN, USA), and 17 with the use of the computer-assisted external fixator Taylor Spatial Frame (TSF) (Smith and Nephew, Memphis, TN, USA). The inclusion criteria were as follows: (1) congenital femoral length deficiency without any axial deformities and (2), independently of the finally applied treatment, the technical possibility of use of each of the analyzed methods. The distraction index did not differ significantly between the groups (p = 0.89). The median lengthening index was the lowest in the IMN group (24.3 d/cm; IQR 21.8–33.1) and statistically different in comparison to the MRS (44.2 d/cm; IQR 42–50.9; p < 0.001) and the TSF groups (48.4 d/cm; IQR 38.6–63.5; p < 0.001). Similarly, the consolidation index in the IMN group (12.9 d/cm; IQR 10.7–21.3) was statistically lower than that in the MRS (32.9 d/cm; IQR 30.2–37.6; p < 0.001) and the TSF (36.9 d/cm; IQR 26.6–51.5; p < 0.001) groups. This study indicates that IMN is a more valuable method of treatment for femoral length discrepancy without axial deformity than MRS and TSF in complication rate and indexes of lengthening and consolidation.

The influence of advanced age in bone healing after intramedullary limb lengthening

BACKGROUND

Distraction osteogenesis with an intramedullary motorized nail is a well-established method to treat leg length discrepancy (LLD). The complex process of bone consolidation is affected by age, location, comorbidities, smoking and gender. The purpose of this case series was to investigate influencing factors in bone regeneration after intramedullary callus distraction.

HYPOTHESIS

Advanced age influences the outcome of intramedullary limb lengthening.

PATIENTS AND METHODS

This retrospective analysis included 19 patients after intramedullary telescopic nailing (PRECICE) on the lower limb with a mean age of 43 years. Bone healing was assessed by distraction and healing parameters such as distraction-consolidation time (DCT), distraction index (DI), healing index (HI), lengthening index (LI), and consolidation index (CI).

RESULTS

Confounding factors such as smoking, previous operations on the treated bone, but also the occurrence of complications, and the number of revision surgeries are independent of the patients' age. Younger patients showed a shorter distraction distance, a lower DCT, a lower DI, a higher HI, and a higher CI than older patients. The complication rate requiring nail exchange was higher among the younger patients. Bony healing was observed in all age groups treated with a telescopic nail regardless of age.

CONCLUSION

Advanced age did not influence bone healing or complication rate in intramedullary lengthening. However, the conclusion is limited by the small patient number.

LEVEL OF EVIDENCE

IV; Case control study.

Implant failure after externally magnetic-controlled nail lengthening

The number of intramedullary procedures to treat leg length discrepancy (LLD) has risen in the past decade and this has led to increased complications such as nail breakage. The aim of this study was to reveal our experience with implant failure after externally magnetic-controlled telescopic bone lengthening. We observed nail-breakage in 4 out of 24 patients (16.7%) after 6 to 15 months (median 13.5 months) following lower limb lengthening for LLD due to non-union or insufficient bone healing. Three femora and one tibia were treated in one posttraumatic and three congenital cases. Three out of the four patients had an elevated Charleston Comorbidity Index (CCI). Revision surgery involved removal of the broken nail and implantation of a trauma nail. At final follow-up all patients showed subjective satisfaction, achievement of desired lengthening with complete bone healing. Based on our results no unequivocal risk factor including number of previous surgeries, comorbidities and age was identified. In cases of delayed bone formation, early revision surgery with an exchange to a trauma nail has to be considered to prevent breakage of the intramedullary telescopic device.

Limb lengthening with PRECICE magnetic nail in pediatric patients: A systematic review

BACKGROUND

Limb lengthening techniques play an increasingly important role in the pediatric orthopedic field. The principles of the osteogenesis distraction bonded traditionally with external fixators; however, the recent deployment of fully implantable systems has been able to overcome severities related to external fixators. The PRECICE^® is an implantable limb lengthening intramedullary nail system that is remotely controlled and magnetically driven.

AIM

To review the current literature available on this matter in order to assess the PRECICE clinical and radiological outcomes and its possible complications in a population of pediatric patients undergoing limb lengthening.

METHODS

Only five studies met the inclusion criteria and were consequently included in the review for a total of 131 patients and 135 femurs. The clinical and radiological outcomes of interest were: the main lengthening obtained, the distraction rate, the period of time to full weight bearing, the consolidation index, and the Association for the Study and Application of Methods of Ilizarov score.

RESULTS

In conclusion, data collected from the articles under investigation were comparable with the exception of the consolidation index. Unfortunately, the study population was too small and the patients’ follow-up was too short to make definitive conclusions.

CONCLUSION

This review shows that the PRECICE Nail System is still a therapeutic challenge in limb lengthening for pediatric orthopedic surgeons; however, careful pre-operative planning and an accurate surgical technique could allow the correction of more complex deformities with a low rate of complications.

Bone lengthening with magnetic nails. Experience in patients younger than 18

BACKGROUND AND GOAL

Bone elongation with magnetic endomedullary nails (MEN) has been proposed as an advantageous alternative to other techniques, by eliminating the drawbacks of external fixation. The aim of this work is to analyze the results and assess the complications in a series of patients under the age of 18.

MATERIAL AND METHODS

From 2014 to 2019, 31 elongations (23 femurs, 8 tibias) using MEN (Precice2™) have been performed in 28 patients younger than 18 (15 males and 13 females). In this observational retrospective study, only patients with follow-up longer than 18 months have been included. The average age has been 14.4 years (8-18). The most relevant aspects analyzed have been: previous shortening/deformity, elongation/correction achieved and time to full weight bearing. Complications and re-interventions have also been assessed.

RESULTS

The elongation achieved has been 5.5cm on average (3-8). In 28 elongations (90.3%) the planned goal of lengthening was achieved. The mean healing index was 1.1months/cm. More than half of elongations (55%) presented complications. Although they produced permanent sequelae in only two patients (7.1%), a total of 9 patients required re-intervention (13 operations). No infections were detected.

CONCLUSIONS

Bone lengthening with MEN in individuals younger than 18 has achieved its goal in more than 90% of patients in an effective, accurate and safe manner. The use of MEN in this series has eliminated the need for external fixators and has successfully tutorized the operated segment. The high number of complications detected in this study remains a concern.

Efficacy of PRECICE Nail in Treatment of Adult Patients With Posttraumatic Femoral Leg Length Discrepancy

Posttraumatic, limb length discrepancy in adults is a challenge to treat, and multiple treatment protocols over the years have shown varying levels of success and complications. Before the introduction of the PRECICE nail in 2011, our preferred method of limb lengthening used an Ilizarov or Taylor Spatial frame. To assess the PRECICE nail, we evaluated the accuracy and complications during treatment in a series of skeletally mature patients with posttraumatic femoral limb length discrepancy. The surgical technique along with a case series of 8 patients are described in detail. On average, the target lengthening for the PRECICE nail was 44 mm, and all patients achieved lengthening within 2 mm and complete bony consolidation. The only observed complication in our series was a broken screw 1 year after the patient started weight-bearing. The PRECICE nail demonstrated promising results and was useful for bone regeneration and consolidation without the need for additional procedures. The rate of complications was low compared with previous methods, making this device an excellent treatment option.

[Open fractures]

Open fractures are associated with a higher rate of infections and delayed fracture healing; therefore, in addition to fracture fixation, infection prevention and soft tissue management are also important. Administration of antibiotics should be carried out as early as possible and over 24-72 h depending on the injury. The initial debridement and assessment of the severity of injury determine the treatment strategy. Fracture fixation follows the general traumatological principles. Simple injury patterns can be treated by primary fixation and wound closure. With substantial contamination, loss of bone or extensive soft tissue damage, temporary fixation and temporary wound closure are carried out. The definitive treatment with soft tissue coverage should be performed within 72 h in order to reduce the risk of fracture-related infections. For osseous segmental defects, different approaches are available to restore bone continuity, depending on the size and soft tissue situation.

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.

Staged reconstruction of unilateral neglected hip dislocation through total hip arthroplasty and subsequent intramedullary femoral lengthening

Background and purpose

Total hip arthroplasty (THA) is a successful approach to treat unilateral symptomatic neglected hip dislocation (NHD). However, the extensive leg length discrepancy (LLD) can hereby only be partially corrected. In case of residual LLD of more than 2 cm, subsequent femoral lengthening can be considered.

Patients/material/methods

Retrospective analysis of clinical data and radiographs of five patients (age 38.1 (28–51) years) with unilateral NHD who underwent THA with (n  = 3) or without (n = 2) subtrochanteric shortening osteotomy (SSO) and secondary intramedullary femoral lengthening through a retrograde magnetically-driven lengthening nail (follow-up 18.4 (15–27) months).

Results

LLD was 51.0 (45–60) mm before and 37.0 (30–45) mm after THA. Delayed bone union at one SSO site healed after revision with autologous bone grafting and plate fixation. Subsequent lengthening led to leg length equalisation in all patients. Complete consolidation was documented in all lengthened segments.

Conclusion

Staged reconstruction via THA and secondary femoral lengthening can successfully be used to reconstruct the hip joint and equalise LLD. The specific anatomical conditions have to be taken into consideration when planning treatment, and patients ought to be closely monitored.

Extracorporal noninvasive acute retraction of STRYDE® for continued lengthening in cases with limited nail stroke: a technical less invasive solution to reload the STRYDE®

With STRYDE^® nails (NuVasive Specialized Orthopedics, San Diego, CA), lengthening nails for full weight-bearing during callus distraction have been available CE-certified since February 2019 in Europe. At present only antegrade femur nails and tibia nails with various lengths and diameters are available. Due to a mismatch of bone length and realizable (implantable) nail length e.g., in cases of skeletal dysplasia or achondroplastic dwarfism, it may happen that a desired lengthening of 6-8 cm cannot be realized because of a nail stroke from only 5 cm. Retrograde usage of antegrade piriformis nails is technically possible as an individual (off label use) procedure since so far no retrograde implants are available. A new method of surgical intervention for retraction of the STRYDE nails at the end of the nail stroke with ongoing callus distraction in patients with bilateral femoral extension under anesthesia with extracorporeal use of the fast distractor device is described in detail. It is safe and with low risk for a reload of a capacity of 3-4 cm for antegrade and retrograde femoral implantation situation for the patient. The acute reload of the STRYDE nail stroke for further distraction is possible without skin incision or invasive soft tissue approaches. Application of the fast distractor extracorporeal within a few minutes is described in detail. The intervention is technically reproducible and can be performed for the proximal femur with antegrade STRYDE nails as well as for the distal femur with retrograde STRYDE nails in adult patients.

[Research progress of intramedullary lengthening nail technology]

Objective

To review the research progress of intramedullary lengthening nail technology.

Methods

The foreign literature on the development history, types, advantages and disadvantages, indications and contraindications, complications, and effectiveness of intramedullary lengthening nail were reviewed and analyzed.

Results

The intramedullary lengthening nail system mainly includes mechanical type, electric motor drive type, and magnetic drive type. Compared with traditional external fixation and lengthening technology, the intramedullary lengthening nail technology has certain advantages in incidence of complications, bone healing, postoperative functional rehabilitation, incision aesthetics, convenience, and patient satisfaction. However, there are also shortcomings, such as pain, uncontrollable distraction rate, device failure, etc. In the clinical application of intramedullary lengthening nails for limb lengthening, the indications should be grasped reasonably, and the related complications should be prevented and treated.

Conclusion

Intramedullary lengthening nails provide a new option for limb lengthening, and the initial effectiveness is good. It is one of the development direction of limb lengthening technology.

Dissociation of a Femoral Intramedullary Magnetic Lengthening Nail During Routine Hardware Removal: A Case Report

CASE

A 15-year-old boy with a right femur length discrepancy secondary to infection underwent hardware removal 1-year status-post right femur osteotomy with placement of an antegrade intramedullary magnetic lengthening nail after successful lengthening of 4.2 cm. During hardware removal, dissociation between the proximal (outer) and distal (inner) components of the device was observed. The distal component was removed using an endoscopic pituitary rongeur after considering multiple possible techniques.

CONCLUSIONS

In the event of nail disconnection during removal of an intramedullary implant, we recommend use of a long pituitary rongeur to retrieve the distal nail component.

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

Background and purpose - In recent years motorized intramedullary lengthening nails have become increasingly popular. Complications are heterogeneously reported in small case series and therefore we made a systematic review of complications occurring in lower limb lengthening with externally controlled motorized intramedullary bone lengthening nails.Methods - We performed a systematic search in PubMed, EMBASE, and the Cochrane Library with medical subject headings: Bone Nails, Bone Lengthening, and PRECICE and FITBONE nails. Complications were graded on severity and origin.Results - The search identified 952 articles; 116 were full text screened, and 41 were included in the final analysis. 983 segments were lengthened in 782 patients (age 8-74 years). The distribution of nails was: 214 FITBONE, 747 PRECICE, 22 either FITBONE or PRECICE. Indications for lengthening were: 208 congenital shortening, 305 acquired limb shortening, 111 short stature, 158 with unidentified etiology. We identified 332 complications (34% of segments): Type I (minimal intervention) in 11% of segments; Type II (substantial change in treatment plan) in 15% of segments; Type IIIA (failure to achieve goal) in 5% of segments; and Type IIIB (new pathology or permanent sequelae) in 3% of segments. Device and bone complications were the most frequent.Interpretation - The overall risk of complications was 1 complication for every 3 segments lengthened. In 1 of every 4 segments, complications had a major impact leading to substantial change in treatment, failure to achieve lengthening goal, introduction of a new pathology, or permanent sequelae. However, as no standardized reporting method for complications exists, the true complication rates might be different.

Combined antegrade femur lengthening and distal deformity correction: a case series

Background

Leg length discrepancy is often associated with distal femur angular deformities such as valgus or flexion. This study aims to report a new technique for simultaneous limb lengthening and acute distal femoral angular correction.

Methods

A retrospective chart review of patients undergoing a single procedure was conducted. Patients included had a single operation where they underwent distal femur osteotomy stabilized with a plate followed by antegrade nailing with a magnetically controlled intramedullary lengthening nail (PRECICE, Ellipse Technologies, Inc., Irvine, CA, USA) using a trochanteric entry.

Results

Seven femurs from 7 patients were included. The average age at operation was 13.6 years, and the leg length difference was 51 mm (range 30–105 mm). Associated deformities were valgus (4), knee flexion contracture (2), and both valgus and flexion contracture (1). Lengthening achieved was 43 mm (P = 0.0036), with a consolidation index of 27 days/cm and reliability of 0.87 (6/7). The 5 patients with angulation had an improvement of valgus from 12 to 4° (P = 0.006) and of the mechanical axis deviation from 34 to 3 mm (P = 0.0001). The range of motion also improved in the 3 patients with contractures. Preoperative gait disturbance, hip and knee pain, and functional scoliosis resolved after the limb deformities were corrected.

Conclusion

Combining a magnetic internal lengthening nail with a second distal osteotomy stabilized with a plate can successfully correct limb length and distal femur deformity acutely without altering the expected result of each procedure.

Pediatric Lower Limb Lengthening Using the PRECICE Nail: Our Experience With 50 Cases

BACKGROUND

Limb lengthening using intramedullary externally controlled motorized devices is becoming increasingly popular. There is limited literature regarding their use in the pediatric and adolescent population. This study reviews outcomes on 50 consecutive cases of intramedullary lower limb lengthening surgery in this population.

METHODS

A retrospective review of all pediatric and adolescent patients treated in our institution by intramedullary lengthening for lower limb length discrepancy using the PRECICE and STRYDE intramedullary lengthening nails between 2013 and 2019. All patients were operated by a single surgeon. Data were prospectively recorded. We report on nail accuracy and reliability, consolidation index, time to full weight-bearing from completion of lengthening, joint range of movement, ASAMI bone and functional scores, presence of problems, obstacles and complications, and patient reported outcome measures (PROMS).

RESULTS

Fifty cases (43 femoral and 7 tibial nails) were performed in 42 patients (20 males, 48% and 22 females, 52%). Six patients had bilateral lengthening and 2 patients had sequential lengthening. There were 28 antegrade femoral, 13 retrograde femoral and 5 tibia PRECICE nails, 2 tibial and 2 femoral PRECICE STRYDE nails. Mean age at surgery was 15 years old (12 to 17). Mean preoperative length discrepancy was 49 mm (20 to 90). Mean achieved lengthening was 46.5 mm (20 to 80). Mean percentage lengthening was 12.6% (5% to 25%). Nail accuracy was 96% and reliability 90%. Average distraction rate was 0.92 mm/d for femur and 0.64 mm/d for tibias. Consolidation index was 28 d/cm (18 to 43) and 39 d/cm (20 to 47), respectively. Time from completion of lengthening to independent full weight-bearing as observed in clinic was 45 days (21 to 70) and 34.2 days (23 to 50), respectively. ASAMI bone and functional scores were favorable and PROMS demonstrated high patient satisfaction levels. No significant complications were observed.

CONCLUSIONS

We have demonstrated excellent clinical results and high patient satisfaction with intramedullary lengthening in a pediatric/adolescent population. We highly recommend thorough preoperative preparation, patient education, and a multidisciplinary approach.

LEVEL OF EVIDENCE

Level IV.

Bone transport with magnetic intramedullary nails in long bone defects

Background

This study describes the outcomes of internal bone transport with magnetic nails in five cases of traumatic segmental femoral bone defects.

Methods

Five patients with open fracture of the femur and diaphyseal bone loss were included between May 2018 and August 2020. The mean femoral defect was 8.7 cm (range 5.6–16.0).

Intervention

We used plate-assisted bone segment transport (PABST) with PRECICE magnetic nails.

Results

All five patients have fully consolidated. The mean consolidation time and index were 7.5 months and 0.8 mo/cm, respectively. The mean follow-up was 21.3 months. The main complications were reduced knee ROM, mild varus deformity and plate bending. Post-operative SF-36, Oxford Knee scores and ED-5Q-5L scores were also compiled for four of five patients. SF-36 and Oxford Knee scores were reported without pre-injury data for comparison. ED-5Q-5L index and VAS were compared UK population norm and were both found to be statistically insignificant (p = 0.071 and p = 0.068, respectively).

Conclusion

Bone transport with magnetic nails has the capacity to obtain good functional recovery in long bone defects despite variable outcome pictures. In response to variable outcome reporting in the literature, we propose a standard reporting template for future studies to facilitate more rigorous analyses.

Intramedullary Bone Lengthening Following Preceding Hip Surgery-A Case Series

Limb length discrepancy (LLD) is a common problem after joint-preserving hip surgeries, hip dysplasia, and hip deformities. Limping, pain, sciatica, paresthesia, and hip instability are common clinical findings and may necessitate limb-lengthening procedures. The study included five patients (two female and three male, mean age of 28 years (20–49; SD: 12)) with symptomatic limb length discrepancy greater than 2.5 cm (mean: 3.6 cm) after total hip arthroplasty (THA), hip dysplasia, or post-traumatic hip surgery. They underwent either ipsi- or contralateral intramedullary limb-lengthening surgeries using the PRECICE™ telescopic nail. All patients achieved complete bone healing and correction of the pelvic obliquity after intramedullary lengthening. None of the patients had a loss of proximal or distal joint motion. The mean distraction-consolidation time (DCT) was 3.8 months, the distraction index (DI) 0.7 mm/day, the lengthening index (LI) 1.8 months/cm, the consolidation index (CI) 49.2 days/cm, the healing index (HI) 1.1 months/cm, and the modified healing index (HI*) 34 days/cm. Intramedullary limb lengthening after LLD in cases of hip dysplasia, hip deformity, and various kinds of hip surgery is a useful and safe procedure in young patients to achieve equal limb length. No functional impairment of the preceded hip surgery was seen.

Tibial lengthening using a retrograde magnetically driven intramedullary lengthening device in 10 patients with preexisting ankle and hindfoot fusion

Background and purpose - Motorized intramedullary lengthening nails (ILNs) have been developed as an alternative to external fixators for long bone lengthening. The antegrade approach represents the standard method for tibial ILN insertion. In patients with preexisting ankle and hindfoot fusion a retrograde approach provides an alternative technique that has not been evaluated so far. We report the outcome of this method in 10 patients. Patients and methods - This retrospective study included 10 patients (mean age 18 years [13-25]) with preexisting ankle and hindfoot fusion who underwent tibial lengthening with a retrograde ILN (PRECICE). The mean leg length discrepancy (LLD) was 58 mm (36-80). The underlying conditions were congenital (n = 9) and post tumor resection (n = 1). The main outcome measures were: ILN reliability, distraction achieved, distraction index (DIX), time to bone healing, consolidation index (CIX), complications, and functional results. Results - All patients achieved the goal of lengthening (mean 48 mm [26-80]). Average DIX was 0.6 mm/day (0.5-0.7) and mean CIX was 44 days/cm (26-60). Delayed consolidation occurred in 2 patients and healed after ILN dynamization or nail exchange with grafting. Toe contractures in 2 other patients were resolved with physiotherapy or tenotomy. Until last follow-up (mean 18 months [12-30]) no true complications were encountered, knee motion remained unaffected, and full osseous consolidation occurred in all patients. Interpretation - In patients with LLD and preexisting ankle and hindfoot fusion distal tibial lengthening using a retrograde ILN is a reliable alternative to the standard approach with equivalent bone healing potential and low complication rates leaving the knee unaffected.

How should we lengthen post-traumatic limb defects? a systematic review and comparison of motorized lengthening systems, combined internal and external fixation and external fixation alone

PURPOSE

Various external fixation systems for lower extremity long bone deformities have been used to various degrees of success, while newer mechanical lengthening nail (MLN) systems offer the potential for improved patient outcomes. Proponents of MLNs argue that they reduce the number of operations, infectious complications, and improve quality of life; however, the evidence to support these claims is scant. This systematic review aims to evaluate the optimal lengthening system for treating post-traumatic long bone deformity.

METHODS

The systematic review was conducted in accordance with PRISMA guidelines. PUBMED, EMBASE, CINAHL, and the Cochrane Library were searched for comparative studies of lengthening techniques among adult patients with axial deformities. Studies were screened and data extracted in duplicate. Treatment groups were pooled into external fixation (EF) alone, combined internal and external fixation (CIF), and mechanical lengthening nail (MLN). Outcomes were mean lengthening achieved, lengthening index, and reported complications.

RESULTS

Thirteen studies with 725 patients (mean age: 29.6 years, 74% male) were included. Nearly all of the studies were either prospective or retrospective cohort studies (n = 12), with one randomized controlled trial of moderate study quality. The mean limb lengthening achieved, lengthening index, and rate of reoperation were similar among the MLN, EF, and CIF groups.

CONCLUSION

The purported decreased the duration of lengthening and the risk of reoperation associated with MLNs was not demonstrated in this review. Patients with post-traumatic leg length deformities remain a challenging patient population to treat, with intervention being associated with high rates of infectious complications and need for revision operations.

How should we lengthen post-traumatic limb defects? a systematic review and comparison of motorized lengthening systems, combined internal and external fixation and external fixation alone

PURPOSE

Various external fixation systems for lower extremity long bone deformities have been used to various degrees of success, while newer mechanical lengthening nail (MLN) systems offer the potential for improved patient outcomes. Proponents of MLNs argue that they reduce the number of operations, infectious complications, and improve quality of life; however, the evidence to support these claims is scant. This systematic review aims to evaluate the optimal lengthening system for treating post-traumatic long bone deformity.

METHODS

The systematic review was conducted in accordance with PRISMA guidelines. PUBMED, EMBASE, CINAHL, and the Cochrane Library were searched for comparative studies of lengthening techniques among adult patients with axial deformities. Studies were screened and data extracted in duplicate. Treatment groups were pooled into external fixation (EF) alone, combined internal and external fixation (CIF), and mechanical lengthening nail (MLN). Outcomes were mean lengthening achieved, lengthening index, and reported complications.

RESULTS

Thirteen studies with 725 patients (mean age: 29.6 years, 74% male) were included. Nearly all of the studies were either prospective or retrospective cohort studies (n = 12), with one randomized controlled trial of moderate study quality. The mean limb lengthening achieved, lengthening index, and rate of reoperation were similar among the MLN, EF, and CIF groups.

CONCLUSION

The purported decreased the duration of lengthening and the risk of reoperation associated with MLNs was not demonstrated in this review. Patients with post-traumatic leg length deformities remain a challenging patient population to treat, with intervention being associated with high rates of infectious complications and need for revision operations.

How should we lengthen post-traumatic limb defects? a systematic review and comparison of motorized lengthening systems, combined internal and external fixation and external fixation alone

PURPOSE

Various external fixation systems for lower extremity long bone deformities have been used to various degrees of success, while newer mechanical lengthening nail (MLN) systems offer the potential for improved patient outcomes. Proponents of MLNs argue that they reduce the number of operations, infectious complications, and improve quality of life; however, the evidence to support these claims is scant. This systematic review aims to evaluate the optimal lengthening system for treating post-traumatic long bone deformity.

METHODS

The systematic review was conducted in accordance with PRISMA guidelines. PUBMED, EMBASE, CINAHL, and the Cochrane Library were searched for comparative studies of lengthening techniques among adult patients with axial deformities. Studies were screened and data extracted in duplicate. Treatment groups were pooled into external fixation (EF) alone, combined internal and external fixation (CIF), and mechanical lengthening nail (MLN). Outcomes were mean lengthening achieved, lengthening index, and reported complications.

RESULTS

Thirteen studies with 725 patients (mean age: 29.6 years, 74% male) were included. Nearly all of the studies were either prospective or retrospective cohort studies (n = 12), with one randomized controlled trial of moderate study quality. The mean limb lengthening achieved, lengthening index, and rate of reoperation were similar among the MLN, EF, and CIF groups.

CONCLUSION

The purported decreased the duration of lengthening and the risk of reoperation associated with MLNs was not demonstrated in this review. Patients with post-traumatic leg length deformities remain a challenging patient population to treat, with intervention being associated with high rates of infectious complications and need for revision operations.

Medium-term evaluation of leg lengthening by ISKD® intramedullary nail in 28 patients: Should we still use this lengthening system?

INTRODUCTION

Lower-limb lengthening presently uses intramedullary nailing. There are motorized systems and mechanical systems, each with their specific complications. The aim of the present study was to assess the efficacy of ISKD® mechanical nails (Orthofix Inc., Texas, USA) on 3D EOS® imaging, and also complications and functional impact.

HYPOTHESIS

The study hypothesis was that nail lengthening is effective but should no longer use the ISKD® system, due to the high rate of specific complications.

MATERIAL AND METHODS

A single-center retrospective study included 28 patients (14 female, 14 male) undergoing limb-lengthening by ISKD® nail between 2005 and 2018. Mean age was 29 years. Twenty-four procedures were femoral and 4 tibial. Lengthening and consolidation parameters and residual discrepancy were measured on 3D EOS® imaging. Complications and functional scores were collated.

RESULTS

Twenty-eight ISKD® nails were implanted in 28 patients. Mean follow-up was 75 months. Planned lengthening was achieved in 78.5% of cases, for a mean lengthening of 34.5mm. Mean lengthening and consolidation indices were respectively 0.94mm/day and 105 days/cm. Length discrepancy showed significant correction, with improvement in functional scores (p<0.01). The overall complications rate was 67.9%, 76% of which were specific to the ISKD® nail.

DISCUSSION

The present study confirmed that nail lengthening is an indication of choice in lower-limb length discrepancy, but that the ISKD® system should no longer be used, due to an excessive rate of specific complications. Complications are due to deficient control of lengthening rate, not found with new-generation motorized nails, which show much fewer complications.

LEVEL OF EVIDENCE

IV, retrospective study without control group.

Clinical results and complication rates of lower limb lengthening in paediatric patients using the PRECICE 2 intramedullary magnetic nail: a multicentre study

Implantable intramedullary nail lengthening devices (e.g., PRECICE 2 system) have been proposed as alternative method to external fixation for lower limb lengthening surgery. The aim of this study was to analyse our outcomes and complications using the PRECICE 2 (P2) nail system and review them in light of the existing literature. A retrospective multicentre study was conducted on patients <18 years, who were treated for limb lengthening using the P2 system. The inclusion criteria were a limb length discrepancy ≥ 30 mm and a follow-up ≥6 months after the end of treatment. A total of 26 (15 males) patients were included, average age was 14.7 ± 2.3 years; 26 nails (21 femur, 5 tibia) were implanted. The average goal lengthening was 49.4 ± 12.4 mm, while average achieved lengthening was 44.4 ± 11.6 mm. Average distraction and consolidation indexes were 11.9 ± 2.1 days/cm and 25.1 ± 8.1 days/cm, respectively. Nail accuracy and reliability were 91.1% and 88.5%, respectively. A total of five problems (joint contractures), one obstacle (femur fracture) and three complications (hip joint subluxation, deep infection and nail running back) were encountered. The P2 nail system is a valid alternative to external fixator for limb lengthening in young patients with no significant angular or rotation deformities. Our study confirms a favourable complication rate and available evidence from literature suggests a lower complication rate than external fixator systems. Nevertheless, surgeons should keep a watchful eye on risk of joint subluxation and mechanical complications with intramedullary lengthening.

A new standard radiographic reference for proximal fibular height in children

Background and purpose - To date there is a lack of studies defining the anatomical position of the proximal fibula. This is especially relevant when planning surgical interventions affecting the knee joint such as permanent or temporary epiphysiodesis to correct leg length discrepancies or angular deformities in growing patients. The goal of this study is to establish a standardized measurement technique and radiological reference values for the position of the proximal fibula in children.Patients and methods - 500 measurements were performed in calibrated long standing anteroposterior radiographs of 256 skeletally immature patients (8-16 years; 233 female, 267 male legs). As a radiographic reference in the frontal plane, the distance between the center of the proximal tibial growth plate and a line tangential to the tip of the fibular head and horizontal to the imaging plane was measured (dPTFH).Results - The average value of dPTFH in the studied population (median age 12 years) was -2.7 mm (SD 3, CI -3.0 to -2.5) and normally distributed (p = 0.1). There were no clinically significant sex or age-dependent differences. The inter-rater reliability analysis showed excellent ICC values (ICC = 0.88; CI 0.77-0.93).Interpretation - This study provides a new radiographic reference value to assess the position of the proximal fibula in relation to the proximal tibia in children and adolescents. This reference can aid preoperative decision-making as to whether additional fibular epiphysiodesis is necessary when performing tibial epiphysiodesis to correct moderate leg-length discrepancies.

Leg Length Discrepancy- Treatment Indications and Strategies

BACKGROUND

Many people have leg-length discrepancies of greater or lesser severity. No evidence-based studies on the need for treatment are currently available.

METHODS

This review is based on publications retrieved by a selective search in the PubMed database, as well as on published recommendations from Germany and abroad and on the authors' own clinical experience.

RESULTS

If the two legs are of different lengths, this is generally because one leg is too short. It is debated whether leg-length discrepancy causes pain or long-term musculoskeletal disturbances. A direct connection to back pain is questionable, but a mildly elevated incidence of knee arthritis seems likely. The evidence base on the indications for treatment of leg-length discrepancy is poor; only informal consensus recommendations are available. There are a wide variety of conservative and surgical treatment options. The final extent of a leg-length discrepancy first noted during the growing years can be estimated with predictive algorithms to within 2 cm. The treatments that can be considered include a shoe insert, a high shoe, or an orthosis, surgically induced slowing of growth by blockade of the epiphyseal plates around the knee joint, or leg lengthening with osteotomy and subsequent distraction of the bone callus with fully implanted or external apparatus. Changes in leg length exert marked mechanical stress on the soft tissues. If the predicted leg-length discrepancy exceeds 5 cm, initial leg-lengthening treatment can already be considered during the patient's growing years.

CONCLUSION

It must be discussed with each patient individually whether the treatment should be conservative or surgical. The extent of the discrepancy is not the sole determining factor for the mode of treatment. The decision to treat is always elective.

OPTY-LINE remote-controlled adjustable intramedullary device implantation in open-wedge high tibial osteotomy: A prospective proof-of-concept pilot and comparison with Tomofix fixed-plate device method

PURPOSE

The objective was to evaluate the clinical and patient-related short- to medium-term performance of the OPTY-LINE nail device for high tibial osteotomy (HTO), comparing a case series of the said device to the established Tomofix fixed-plate device.

PATIENTS AND METHODS

Males with symptomatic medial compartmental osteoarthritis and no serious (co-morbid) knee pathology were followed up, five Tomofix and six OPTY-LINE patients. Patients underwent computed tomography assessment and completed Knee Injury and Osteoarthritis Outcome score (KOOS) and osteotomy surgery patient satisfaction questionnaires, 3 and 6 months post-surgery. A radiologist impression score and a quantitative digital bone density analysis were performed by two independent radiologists. Mann-Whitney U test was applied for inferential statistical tests.

RESULTS

At 6 months post-surgery, for Tomofix, the median radiologists' healing impression score was 'progressive healing' versus 'union virtually complete' for the OPTY-LINE nail; bone healing quotient was 1.30 (standard deviation (SD) 1.74) versus 1.78 (SD 1.58), p = 0.18. The post-operative absolute surgical accuracy was a mean 12 (7.5) for Tomofix versus 4.1 (2.3) for OPTY-LINE, p = 0.052. At baseline, however, Tomofix patients had more knee symptoms, as determined by KOOS symptom sub-score, when compared to the OPTY-LINE cohort (p = 0.009).

CONCLUSION

This initial, non-randomized, comparative evaluation of the OPTY-LINE device for HTO has produced similar outcomes to patients treated with the established Tomofix device. In particular, the rate of post-surgical bone regeneration and surgical accuracy achieved with the OPTY-LINE device are encouraging. Large-scale randomized controlled studies with longer follow-up are indicated to further evaluate the clinical and patient-related outcome performance for OPTY-LINE.

Post-retrieval functionality testing of PRECICE lengthening nails: The "Sleeper" nail concept

INTRODUCTION

PRECICE intramedullary magnetic lengthening nails, introduced in 2011, have changed the landscape of long bone limb lengthening. The implants have a stroke ranging from 5 to 8 cm, but it may be desirable to perform part of the lengthening at one treatment, allow bone healing, leave the implant in place, dormant, and then return one or more years later to re-lengthen with the same implant. We call this the "sleeper" nail concept. This strategy may be gentler for the joints and soft tissues. Would the nail mechanism still be functional one or more years later?

METHODS

We tested 102 intact, consecutively explanted nails. Using a "fast magnet," the male part was lengthened to 5 mm short of its maximum stroke capacity and retracted back to 35 mm (all nails start with the male part exposed 30 mm). The nails passed the test if the male part succeeded in lengthening to 5 mm short of the maximum stroke capacity and back to 35 mm (or only retract in case fully deployed at testing). During our testing, the nails were prevented from reaching their full capacity of lengthening/retraction to avoid jamming the gears. Failure was defined as the inability or partial ability to complete the process.

RESULTS

Eighty-six nails (84.3%) performed successfully according to our testing standard. When comparing successful and failed nails in terms of nail type, generation, diameter, length and in vivo interval, there was no statistical significance. Comparing both groups in terms of status at testing (fully deployed or not) showed statistical significance with 9 of the 16 failed nails fully deployed at testing (p < 0.001).

CONCLUSION

Dormant PRECICE nails can be reactivated for further lengthening. The results imply that full deployment may damage the mechanism, making future re-use by retracting and then re-lengthening unsuccessful. The candidate nails for this purpose should not have any signs of clear damage (bending or breakage) and should not have been fully deployed. However, surgeons and patients should be aware of the need for possible nail exchange if the "sleeper" nail fails to wake up.

LEVEL OF EVIDENCE

Level IV case series analysis of retrieved surgical implants.

Regenerate Deformity with the Precice Tibial Nail

Limb lengthening by distraction osteogenesis is an accepted orthopaedic surgical technique. The Precice intramedullary lengthening system is the most recent innovation in limb lengthening. Early results have been favourable in femoral lengthening but there is little reported on the outcome in tibial lengthening. The aim of this study is to present our early results of Precice tibial lengthening, and the stepwise evolution of our surgical technique.

Materials and methods

A case series of 17 consecutive tibial lengthenings were prospectively analysed. Healing index, length achieved, range of motion, and complications were recorded. The initial cases followed the recommended surgical technique. Progressive regenerate deformity during lengthening required changes to the surgical method.

Results

No cases were lost to follow-up. All the nails lengthened at the desired rate. There were no complications of infection or poor regenerate formation. Progressive valgus and procurvatum was prevented in later cases by the positioning of Poller blocking screws at the time of nail insertion.

Conclusion

The tibial Precice nail is successful in obtaining length and good regenerate formation. The recommended technique was insufficient to control the deforming forces from the lower limb muscle compartments during lengthening. We therefore recommend the addition of multiple blocking screws in an amended technique.

How to cite this article

Wright SE, Goodier WD, Calder P. Regenerate Deformity with the Precice Tibial Nail. Strategies Trauma Limb Reconstr 2020;15(2):98-105.

PRECICE intramedullary nail in the treatment of adult leg length discrepancy

BACKGROUND

Limb length discrepancy in adults is not an uncommon occurrence following trauma and limited literature exists on limb lengthening in skeletally mature populations using modern techniques. This study aimed to evaluate outcomes of limb lengthening surgery using the PRECICE magnetic limb lengthening intramedullary nail in an adult population.

METHOD

From 2013 to 2018, 21 adult patients were operated by a single surgeon, using the PRECICE nail, for lower limb length discrepancies. Low energy femoral osteotomies were performed via a limited approach. Tibial osteotomies were performed using a percutaneous technique and Gigli saw. A distraction rate of 0.75 mm/day was used as a standard protocol with change in rate of 0.25 mm/day implemented as required. Patients were followed up until radiological evidence of consolidation.

RESULTS

Mean patient age was 36.4 years (range 21-65), with 19 patients being male. Seventeen femoral and four tibial lengthenings were performed. Mean follow up was 15.1 months (range 6-30). Eleven patients underwent deformity correction at time of nail insertion (10 femoral, 1 tibial). All patients achieved correct lengthening (mean gain 36.5 mm, range 18-80 mm). All patients consolidated their regenerate bone (mean 268 days, range 99-825). Mean femoral consolidation index was 6.5, mean tibial consolidation index was 16.1 (p = 0.002). Six patients had delayed consolidation of regenerate bone. Increasing age (p = 0.04), number of prior operations (p = 0.03), and smoking (p = 0.01) were associated with delayed consolidation. Four of 21 (19%) patients suffered a complication, with one implant failure.

CONCLUSIONS

The PRECICE intramedullary nail is a reliable limb lengthening device in skeletally mature patients, providing predictable lengthening and bone regeneration.

Does the external remote controller's reading correspond to the actual lengthening in magnetic-controlled growing rods?

PURPOSE

Magnetic-controlled growing rods (MCGRs) are now routinely used in many centres to treat early-onset scoliosis (EOS). MCGR lengthening is done non-invasively by the external remote controller (ERC). Our experience suggests that there may be a discrepancy between the reported rod lengthening on the ERC and the actual rod lengthening. The aim of this study was to investigate this discrepancy.

METHODS

This was a prospective series. Eleven patients who were already undergoing treatment for EOS using MCGRs were included in this study.

RESULTS

One hundred and ninety-two sets of ultrasound readings were obtained (96 episodes of rod lengthening on dual-rod constructs) and compared to their ERC readings. Only 15/192 (7.8%) readings were accurate; 27 readings (14.9%) were false positive; and 8 readings (4.2%) were an underestimation while 142 readings (74.0%) were an overestimation by the ERC. Average over-reporting by the ERC was 5.31 times of the actual/ultrasound reading. When comparing interval radiographs with lengthening obtained on ultrasound, there was a discrepancy with an average overestimation of 1.35 times with ultrasound in our series. There was a significant difference between ERC and USS (p = 0.01) and ERC and XR (p = 0.001). However, there was no significant difference between USS and XR (p > 0.99).

CONCLUSION

The reading on the ERC does not equate to the actual rod lengthening. The authors would recommend that clinicians using the MCGR for the treatment of early-onset scoliosis include pre- and post-extension imaging (radiographs or ultrasound) to confirm extension lengths at each outpatient extension. In centres with ultrasound facilities, we would suggest that patients should have ultrasound to monitor each lengthening after distraction but also 6-month radiographs. These slides can be retrieved under Electronic Supplementary Material.

Lengthening Nails for Distraction Osteogenesis: A Review of Current Practice and Presentation of Extended Indications

PURPOSE

Circular frames have been the gold standard of treatment for complex deformity corrections and bone loss. However, despite the success of frames, patient satisfaction has been low, and complications are frequent. Most recently, lengthening nails have been used to correct leg length discrepancies. In this article, we review the current trends in deformity correction with emphasis on bone lengthening and present our case examples on the use of lengthening nails for management of complex malunions, non-unions, and a novel use in bone transport.

MATERIALS AND METHODS

A nonsystematic literature review on the topic was performed. Four case examples from our institute, Brighton and Sussex University Hospitals, East Sussex, England, UK, were included.

RESULTS

New techniques based on intramedullary bone lengthening and deformity correction are replacing the conventional external frames. Introduction of lengthening and then nailing and lengthening over a nail techniques paved the way for popularization of the more recent lengthening nails. Lengthening nails have gone through evolution from the first mechanical nails to motorized nails and more recently the magnetic lengthening nails. Two case examples demonstrate successful use of lengthening nails for management of malunion, and two case examples describe novel use in management of non-unions, including the first report in the literature of plate-assisted bone segment transport for the longest defect successfully treated using this novel technique.

CONCLUSION

With the significant advancement of intramedullary lengthening devices with lower complications rates and higher patient satisfaction, the era of the circular frame may be over.

HOW TO CITE THIS ARTICLE

Barakat AH, Sayani J, O'Dowd-Booth C, et al. Lengthening Nails for Distraction Osteogenesis: A Review of Current Practice and Presentation of Extended Indications. Strategies Trauma Limb Reconstr 2020;15(1):54-61.

Complications and Effectiveness of Intramedullary Limb Lengthening: A Matched Pair Analysis of Two Different Lengthening Nails

Background

Intramedullary limb lengthening has become an accepted concept in reconstructive surgery, but as yet comparative clinical studies are missing. We compared the complications and effectiveness of two types of intramedullary limb lengthening devices (ISKD®; Fitbone®).

Materials and methods

In a retrospective series of 278 consecutive patients with internal limb lengthening, we found 17 matching pairs in terms of predefined matching parameters (group I with ISKD® and group II with Fitbone®). The surgeries were all performed with the same technique and managed with equivalent pre- and postoperative treatment protocols. The performance of the implants was evaluated using the distraction index and the weight-bearing index. Complications were rated according to Paley's classification for external lengthening.

Results

The distraction index in group I (ISKD®) was 0.99 mm/day (range 0.55-1.67) and in the group II (Fitbone®) 0.55 mm/day (range 0.14-0.92) (p value = 0.001). The mean weight-bearing index differed between group I and group II from 32.0 day/cm (range 16.4-64.0) to 51.6 day/cm (25.8-95.0) (p value = 0.001). There were 17 recorded incidents in group I and 19 in group II during lengthening.

Conclusion

Specific technical handicaps of the two systems, such as the so-called runaway of the ISKD® and backtracking of the Fitbone® nails seem to result in different distraction index and weight-bearing index. Further comparative studies might induce technical progress in intramedullary limb lengthening.

How to cite this article

Thaller PH, Frankenberg F, Degen N, et al. Complications and Effectiveness of Intramedullary Limb Lengthening: A Matched Pair Analysis of Two Different Lengthening Nails. Strategies Trauma Limb Reconstr 2020;15(1):7-12.

Repeated intramedullary stabilization following failed telescopic nail lengthening - An appropriate treatment strategy

Externally magnetic-controlled intramedullary telescopic nails for bone lengthening have recently gained popularity due to many advantages when compared to more traditional lengthening methods. Patients requiring lengthening often present with a clinical history of previous multiple surgeries increasing the risk for complications of further procedures. However, studies regarding the treatment of complications following implantation of these devices remain scarce in literature. Therefore, we report our experience with revision surgery after lengthening with a telescopic intramedullary lengthening nail. In 6 out of 20 cases (30%) of lower limb lengthening for leg length discrepancy revision surgery was necessary. Two revisions were necessary due to nail breakage while the other 4 cases required a secondary procedure for non-union. In all cases, revision surgery included standard intramedullary locking nailing with additional autologous bone grafting. The median interval between index and revision surgery was 11.5 months (range 2-15 months). Satisfying clinical results, the intended extend of lengthening and bony consolidation was observed in all 6 patients. We conclude that revision surgery using an intramedullary locking nail with autologous bone grafting after failed telescopic nail-based lengthening represents an useful salvage procedure in these cases.