Introduction. The FitBone lengthening nail (Orthofix UK) is an intramedullary device licensed for the lengthening of long bones in adults in the UK. It contains a motor powered by electricity transmitted via an induction coil placed underneath the skin. It was developed in Germany two decades ago but uptake in the UK has only started more recently. The aim of this study was to review the first cohort of FitBone lengthening nails in a unit with significant experience of other lengthening nails (including PRECICE and Stryde). Materials & Methods. Demographic, clinical and radiological data was prospectively collected on all FitBone cases starting in February 2022. Accuracy of lengthening rate, patient satisfaction and implant issues were all considered. Complications and learning points were recorded and discussed by the multidisciplinary team involved in the patients care. Results. Eleven lengthening nails were inserted between February and November 2022 (6 right femurs, 5 left femurs). The average patient age was 31 (16–57) with 4 females and 7 males. The average lengthening achieved was 44mm (13– 70) over an average of 59 days (35 to 104). Significant technical issues were encountered in this cohort of patients including slow opening up at osteotomy site (3 requiring speeding up of programme), early consolidation (one requiring re-do osteotomy) and backing out of locking screws (3 out of 11 nails). There were also patient use concerns with difficulty using the motor and the inability to reverse the lengthening without an additional component to the motor. Conclusions. We present the first UK cohort of patients with femoral lengthening using the FitBone implant and device. We highlight the technical and patient issues encountered during this learning curve and propose solutions to avoid these pitfalls

Introduction. Intramedullary lengthening devices have been in use in older children with closed /open growth plates with good success. This study aims to present the early experience of the FITBONE nail since withdrawal of the PRECICE nail. Materials & Methods. Retrospective analysis of both antegrade and retrograde techniques were utilized. Only patients where union was achieved and full weight bearing commenced were included. The complication rate, length gained, distraction index, weight bearing index (WBI) as well as mechanical axes were analysed. Results. 14 (7 males, 7 females) of a total of 16 (7 males, 7 females) patients with a mean age of 16.9 years with varied diagnosis of LLD were analysed. The mean length gained was 38 mm with an average distraction index of 0,74 mm/day. WBI in these patients on average was 59,6 days/cm lengthened. 6 complications were observed, including two nonunions (successfully treated) and a knee subluxation. Mechanical axis deviation improved from 13,3 mm to 6 mm on average. Overall there has been a nonsignificant tendency for WBI to decrease (Spearman's rank correlation coefficient −0.47, p=0.08) with increasing number of cases done, while no correlation between length gained and WBI (−0.01, p=0.96, respectively) was observed. Some nuances will be discussed. Conclusions. Limb lengthening with the FITBONE nail is relatively safe and efficient, however no significant change was seen in the outcome with previous motorized nails

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

Introduction. Management of deformity involving limb length discrepancy (LLD) using intramedullary devices offers significant benefits to both patients and clinicians over traditional external fixation. Following the withdrawal of the PRECICE nail, the Fitbone became the primary implant available for intramedullary lengthening and deformity correction within our service. This consecutive series illustrates the advantages and complications associated with the use of this device, and describes a novel technique modification for antegrade intramedullary lengthening nails. Materials & Methods. A retrospective cohort review was performed of patient outcomes after treatment with the Fitbone nail at two tertiary referral limb reconstruction services (one adult, one paediatric) between January 2021 to December 2023. Aetiology, indications, initial and final LLD, use of concomitant rail assisted deformity correction (ORDER), removal time and healing index were assessed. Complications of treatment were evaluated and described in detail, alongside technique modifications to reduce the rate of these complications. Results. 21 nails (18 femoral, 2 tibial, 1 humeral) were inserted in 6 adult and 13 paediatric patients. Post-traumatic and congenital/developmental LLD were the most common indications for surgery in the adult and paediatric cohorts respectively. ORDER was employed in 11 cases (9 femurs and 2 tibias). Treatment goals were achieved in all but one case. Complications included superficial infection, locking bolt migration, periprosthetic fracture and component failure. Seven patients required unplanned returns to theatre. Conclusions. The Fitbone nail is an established option for intramedullary limb lengthening, however its use in the UK has been relatively limited compared to the PRECICE until 2021. Our data helps to define its place for limb lengthening and complex deformity correction in both adult and paediatric patients, including in humeral lengthening and retrograde femoral insertion across an open physis. We have identified important potential risks and novel techniques to simplify surgery and avoid complications

Introduction

At Sheffield Children's Hospital, treatment of leg length discrepancy is a common procedure. Historically, this has been done with external fixators. With the development in intramedullary technology, internal nails have become the preferred modality for long bone lengthening in the adolescent population. However, it is important to review whether this technology practically reduces the known challenges seen and if it brings any new issues. Therefore, the aim of this review is to retrospectively evaluate the therapeutic challenges of 16 fit-bone intramedullary femoral lengthening's at Sheffield Children's Hospital between 2021–2022.

Introduction. Fully implantable distraction nails are frequently used for lengthening of the lower leg. What are the indications for humerus lengthening and which results can be expected?. Materials and Methods. The humerus as the best healing bone in the human body is suitable for lengthening with a nail as well but the indications are rare in comparison with the lower legs. Especially when driving a car or when working on a tablet length discrepancy of the arms of more than 4–5cm may cause severe hardening of the cervical muscles and induce chronical pain in the upper spine. Results. A distraction nail (FITBONE) was used in 5 cases for humerus lengthening. The nail was inserted in all cases from proximal. The mean age of the patients was 34 years. The mean lengthening amount was 58mm (55–100). In one case the system was exchanged to reach the desired length. There was no infection, no radial nerve irritation and no chronical shoulder pain. The system was removed in 4 cases in an average of 15 months the other nail will be removed soon as well. Conclusions. The preliminary results of our 5 cases demonstrate, that the FITBONE device is advantageous for lengthening the humerus, if the initial length is sufficient for implantation. In comparison with the use of external fixators the functional outcome, the comfort of treatment and the cosmetic result is amazing

Shortness of an extremity due to different causes is an issue that may adversely affect human life functional and psychologically. In this study, in the light of previous studies, it is aimed to develop a new expandable intramedullary system, providing lengthening in order to remove previous problems and complications and to annihilate leg length discrepancies at present and future without second surgical intervention as far as possibble by lenghtening the intramedullary nail. To this end, a new electromechanically activated intramedullary nail has been designed and generated. The intramedullary nail was designed to perform extremity lengthening electro-mechanically. The 3D design of the system is performed with computer software and the rapid and metal prototype of the system has been produced. The intramedullary nail system is comprised of three main units; Mechanical transmission unit, Electronic unit, Lengthening unit. The nail system is designed to function both mechanically and electronically complying with the requirement. This also provides an advantage that if any one (mechanic or electronic) fails, the lengthening process can continue with the other. Compression tests are applied in order to evaluate the strength of the system. The deformation values of the parts are recorded and stress values of each parts were calculated. The new system needs only 300N loading for mechanical lengthening. When 800N is considered as average human weight, the implant must withstand minumum 2400N load. Considering the safety conditions, we applied 4000N load on the new system. At 4000N, the whole system shows only 1.465 mm deformation which is less than the gap between the two bone parts. Also, when the system is implanted inside the bone, the loads are distributed proportionally between the bone and the implant. So, except for extraordinary conditions, the newly developed system is highly rigid and safe. In each applied method, lots of complications whether general or method-specific are seen. When the methods like Albizzia, ISKD and FITBONE avaliable and widely used today are examined separately, complications specific to these methods can be clearly observed [1–12]. Bliskunov Nail, Albizzia Nail and ISKD [13–18] have mechanical working principles and in these systems, lengthening process is obtained by rotational movement of the extremity. This rotational movement causes complications like pain, dislocation and uncontrolled lengthening [11,13,16,19–21]. In our newly developed system, only axial stimulation is needed for the activation of the mechanism. This is one of the advantages of our system. Both the mechanical unit and the electronical units are designed to be extended 0.1 mm at each activation. This means that the optimal amount of distraction (1mm/day) can be achieved in a controlled way. In other systems, the distraction amount can not be fully controlled and complications seen on other systems [1, 6, 8–10], like distruption of callus due to the excessive distraction and nonunion of the bone can be encountered. The success of the system at practice will be examined with in-vivo animal experiments and according to the results, it will be ready for use on human by performing necessary restorations

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.

Limb lengthening by callus distraction and external fixation has a high rate of complications. We describe our experience using an intramedullary nail (Fitbone) which contains a motorised and programmable sliding mechanism for limb lengthening and bone transport. Between 2001 and 2004 we lengthened 13 femora and 11 tibiae in ten patients (seven men and three women) with a mean age of 32 years (21 to 47) using this nail. The indications for operation were short stature in six patients and developmental or acquired disorders in the rest.

The mean lengthening achieved was 40 mm (27 to 60). The mean length of stay in hospital was seven days (5 to 9). The mean healing index was 35 days/cm (18.8 to 70.9). There were no cases of implant-related infection or malunion.

Aims

Double-level lengthening, bone transport, and bifocal compression-distraction are commonly undertaken using Ilizarov or other fixators. We performed double-level fixator-assisted nailing, mainly for the correction of deformity and lengthening in the same segment, using a straight intramedullary nail to reduce the time in a fixator.

Ollier’s disease is characterised by severe deformity of the extremities and retarded growth because of multiple enchondromas. For correction of deformity, the Ilizarov method has been used although it has many complications. A 17-year-old boy with Ollier’s disease had a limb-length discrepancy of 17.4 cm, with a valgus deformity of the right knee and recurvatum of the femur of 23°. He had undergone three unsuccessful attempts to correct the deformities by using external fixators. We used a fully implantable, motorised, lengthening and correction nail (Fitbone) to achieve full correction of all the deformities without complications. We decided to carry out the procedure in three stages. First, we lengthened the femur by 3.6 cm and the tibia by 4 cm. We then exchanged the femoral nail for a longer implant and achieved a further 6 cm of length. This reduced the shortening to 3.8 cm. When the boy has finished secondary school we will adjust the remaining discrepancy.

Between October 2001 and September 2009 we lengthened 242 lower-limb segments in 180 patients using the Intramedullary Skeletal Kinetic Distractor (ISKD). Mechanical failure was defined either as breakage of the ISKD or failure of the internal mechanism to activate. Retrieved nails which failed mechanically were examined by the manufacturer for defects. In all, 15 ISKDs in 12 patients (13 limbs) failed mechanically representing an overall failure rate of 6.2%, with fracture of the device occurring in ten of the 15 failures. Two nails in one patient failed to lengthen and had to be replaced. The manufacturer detected an error in the assembly of the nail, which prompted a wide recall. One nail jammed after being forcefully inserted, and two nails failed to lengthen fully. Lengthening was achieved in all 12 patients, although three required a second operation to exchange a defective nail for a new, functioning device.

The ISKD is a complex mechanical device which lengthens by the oscillation of two telescopic sections connected by a threaded rod. The junction between these sections is surrounded by a keyring collar. This keyring collar is the weakest part of the device.

The June 2012 Children’s orthopaedics Roundup³⁶⁰ looks at; open reduction for DDH; growing rod instrumentation for scoliosis; acute patellar dislocation; management of the relapsed clubfoot; clubfoot in Iran; laughing gas and fracture manipulation; vascularised periosteal fibular grafting for nonunion; slipped upper femoral epiphysis; intramedullary leg lengthening and orthopaedic imaging and defensive medicine.

Aims

Patients undergoing femoral lengthening by external fixation tolerate treatment less well when compared to tibial lengthening. Lengthening of the femur with an intramedullary device may have advantages.

Internal lengthening devices in the femur lengthen along the anatomical axis, potentially creating lateral shift of the mechanical axis. We aimed to determine whether femoral lengthening along the anatomical axis has an inadvertent effect on lower limb alignment. Isolated femoral lengthening using the Intramedullary Skeletal Kinetic Distractor was performed in 27 femora in 24 patients (mean age 32 years (16 to 57)). Patients who underwent simultaneous realignment procedures or concurrent tibial lengthening, or who developed mal- or nonunion, were excluded. Pre-operative and six-month post-operative radiographs were used to measure lower limb alignment. The mean lengthening achieved was 4.4 cm (1.5 to 8.0). In 26 of 27 limbs, the mechanical axis shifted laterally by a mean of 1.0 mm/cm of lengthening (0 to 3.5). In one femur that was initially in varus, a 3 mm medial shift occurred during a lengthening of 2.2 cm.

In a normally aligned limb, intramedullary lengthening along the anatomical axis of the femur results in a lateral shift of the mechanical axis by approximately 1 mm for each 1 cm of lengthening.

We report the results of intramedullary leg lengthening conducted between 2002 and 2009 using the Intramedullary Skeletal Kinetic Distractor in 69 unilateral lengthenings involving 58 femora and 11 tibiae. We identified difficulties that occurred during the treatment and assessed whether they were specifically due to the implant or independent of it. Paley’s classification for evaluating problems, obstacles and complications with external fixators was adopted, and implant-specific difficulties were continuously noted. There were seven failures requiring premature removal of the device, in four due to nail breakage and three for other reasons, and five unsuccessful outcomes after completion of the lengthening. In all, 116 difficulties were noted in 45 patients, with only 24 having problem-free courses. In addition to the difficulties arising from the use of external fixators, there were almost the same number again of implant-specific difficulties.

Nevertheless, successful femoral lengthening was achieved in 52 of the 58 patients (90%). However, successful tibial lengthening was only achieved in five of 11 patients (45%).

Femoral lengthening using the Intramedullary Skeletal Kinetic Distractor is a new technique. However, with intramedullary distraction the surgeon has less control over the lengthening process. Therefore, 33 femora lengthened with this device were assessed to evaluate the effect of operative variables under the surgeon’s control on the course of lengthening. The desired lengthening was achieved in 32 of 33 limbs. Problems encountered included difficulty in achieving length in eight femora (24%) and uncontrolled lengthening in seven (21%). Uncontrolled lengthening was more likely if the osteotomy was placed with less than 80 mm of the thick portion of the nail in the distal fragment (p = 0.052), and a failure to lengthen was more likely if there was over 125 mm in the distal fragment (p = 0.008). The latter problem was reduced with over-reaming by 2.5 mm to 3 mm. Previous intramedullary nailing also predisposed to uncontrolled lengthening (p = 0.042), and these patients required less reaming.

Using the Intramedullary Skeletal Kinetic Distractor, good outcomes were obtained; problems were minimised by optimising the position of the osteotomy and the amount of over-reaming performed.