Leg lengthening with a motorized nail in adolescents : an alternative to external fixators?

Femoral Lengthening in Children: A Comparison of Motorized Intramedullary Nailing Versus External Fixation Techniques

BACKGROUND

Femoral lengthening is associated with high complication rates often related to the type of surgical device used to perform the lengthening. The advent of intramedullary lengthening devices has promised a reduction in complications when compared with external fixation systems. The purpose of this study was to compare the clinical outcomes of femoral lengthening in children using a motorized intramedullary nail (Precice) versus an external fixation system (Taylor Spatial Frame-TSF; or Monolateral Rail System-MRS) at a single institution, single surgeon practice.

METHODS

This study is a retrospective comparison of pediatric patients who had previously undergone femoral lengthening (±deformity correction). Patients ages 8 to 18 years of age were included and grouped based on whether they had undergone Precice nailing or external fixation (TSF or MRS) between 2010 and 2019.

RESULTS

Twenty-seven patients (32 femurs) were included. Thirteen patients (15 femurs) had undergone Precice nailing and 14 patients (17 femurs) had undergone external fixation. The Precice group had significantly fewer problems, obstacles, and complications than the external fixation group, Precice 6.6%, 0%, 0%, respectively, and external fixation 47.1%, 29.4%, 0% respectively (P<0.01). Unplanned return to the operating room occurred in 4 cases, solely in the external fixation group. There were no differences in percentage of goal length achieved, Precice (mean 93.6%, range: 66.7% to 114.3%), external fixation (mean 96%, range: 76.9% to 117.5%) P=0.31 and total length achieved, Precice (mean: 44 mm, range: 20 to 80 mm), external fixation (mean: 46 mm, range: 10 to 70 mm) P=0.72. There was no difference in consolidation index, Precice (24.1 d/cm), external fixation (28.5 d/cm) P=0.36. The Precice group had a significantly shorter length of stay (mean: 2.2 d, range: 1 to 4 d), compared with the external fixation group (mean: 3.7 d, range: 2 to 8), P=0.01.

CONCLUSIONS

Femoral lengthening in children using a motorized intramedullary nail was associated with a markedly reduced rate of complications and shorter length of stay compared with external fixation.

LEVEL OF EVIDENCE

Level III.

Retrograde Extramedullary Lengthening of the Femur Using the PRECICE Nail: Technique and Results

BACKGROUND

Lengthening of long bones by distraction osteogenesis is now possible using intramedullary lengthening nails. Constraints of bone size, medullary canal obstruction, and the presence of an open physis are contraindications in skeletally immature patients. We present a technique describing the "off-label" use of a magnetic lengthening nail placed extramedullary and in retrograde manner, for lengthening of the femur in skeletally immature patients.

METHODS

A retrospective review of 5 skeletally immature patients with significant length discrepancy of the femur are presented along with a description of the surgical technique. Data collected included age, sex, date of surgery, diagnosis, presence of associated deformities, the magnitude of length discrepancy, the amount of length gained, the amount of time to achieve full weight-bearing, the time to hardware removal, and any complications.

RESULTS

There were 5 patients (3 females). The mean age was 7.2±2.7 years (4 to 10 y). The mean limb length discrepancy was 6.5±3.7 cm (3.5 to 11 cm). A mean length of 3.46±0.4 cm (3.1 to 4 cm) was achieved which represents 12.9±1.8% (10.32 to 13.47%) of the bone length. The time taken to achieve full weight-bearing ambulation was 89.2±19.3 days (60 to 109 d) or 12.7 weeks. All hardware was removed 247.6±215.6 days (99 to 628 d) after surgery. Patients were followed up for a mean duration of 19.2 months (11 to 30 mo). No supplemental fixation was required and no complications were noted. Acute deformity correction was also performed at the time of surgery in 2 patients who had distal femur valgus deformity.

CONCLUSIONS

Retrograde extramedullary lengthening of the femur is an option that should be considered for limb length equalization in skeletally immature patients. It avoids the inconvenience of external fixation and can be used to simultaneously correct deformities of the distal femur. Although the total amount of length gained is modest, we believe it is a promising limb lengthening technique that merits further investigation.

LEVEL OF EVIDENCE

Level III.

[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.

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.

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.

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.

Pelvic Support Hip Reconstruction with Internal Devices: An Alternative to Ilizarov Hip Reconstruction

Aim and objective

Ilizarov hip reconstruction (IHR) is a traditional method of salvaging chronic adolescent problem hips but faces practical problems from external fixators leading to reduced compliance. We present the same reconstruction utilising only internal devices with a modification in technique and aim to review early results.

Materials and methods

We retrospectively evaluated eight patients between 2014 and 2017 with chronic painful hips treated by a two-stage reconstruction; stage 1 included femoral head resection and pelvic support osteotomy using double plating, while stage 2 comprised distal femoral osteotomy avoiding varus followed by insertion of retrograde magnetic nail for postoperative lengthening. Patients continued physiotherapy postoperatively while protecting from early weight-bearing.

Results

At mean follow-up of 19 months (range 6–36), all osteotomies healed with bone healing index of 47 days/cm (range 30–72). Pain improved from 8.3 (range 7–9) to 2 (range 0–6), while limb length discrepancy got corrected from 4.3 cm (range 3–5) to 1.4 cm (range 0–2.5) at final follow-up. Trendelenburg sign was eliminated in three and delayed in five. No examples of infection or permanent knee stiffness were noted. One patient had plates breakage due to mechanical fall and one had 35 mm of lateral mechanical axis deviation requiring corrective osteotomy.

Conclusion

Pelvic support hip reconstruction with exclusive internal devices is a technique in evolution with encouraging early results. It avoids common complications of external fixators and facilitates quick rehabilitation of joints. Refraining from distal varus can effectively eliminate Trendelenburg gait, albeit with some degree of lateral mechanical axis deviation. Unlike external fixation where there is a possibility of gradual correction, this staged procedure of internal fixation is technically demanding with a learning curve.

Clinical significance

Pelvic support hip reconstruction performed by internal implants is a viable alternative to IHR with potential benefits.

How to cite this article

Metikala S, Kurian BT, Madan SS, et al. Pelvic Support Hip Reconstruction with Internal Devices: An Alternative to Ilizarov Hip Reconstruction. Strategies Trauma Limb Reconstr 2020;15(2):91–97.

Pelvic Support Hip Reconstruction with Internal Devices: An Alternative to Ilizarov Hip Reconstruction

Aim and objective

Ilizarov hip reconstruction (IHR) is a traditional method of salvaging chronic adolescent problem hips but faces practical issues from external fixators leading to reduced compliance. We present the same reconstruction procedure using only internal devices with a modification in the technique and review early results.

Materials and methods

We retrospectively evaluated eight patients between 2014 and 2017 with chronic painful hips treated by two-stage reconstruction; stage I included femoral head resection and pelvic support osteotomy using double plating, whereas stage II comprised distal femoral osteotomy avoiding varus followed by the insertion of a retrograde magnetic nail for postoperative lengthening. Patients continued physiotherapy postoperatively while protecting from early weight-bearing.

Results

At a mean follow-up of 19 months (range, 6–36), all osteotomies healed with a bone healing index of 47 days/cm (range, 30–72). Pain improved from 8.3 (range, 7–9) to 2 (range, 0–6) while the limb length discrepancy got corrected from 4.3 cm (range, 3–5) to 1.4 cm (range, 0–2.5) at the final follow-up. Trendelenburg sign was eliminated in three patients and delayed in five patients. No examples of infection or permanent knee stiffness were noted. One patient had plate breakage due to mechanical fall, and another patient had 35 mm of lateral mechanical axis deviation (MAD) requiring corrective osteotomy.

Conclusion

Pelvic support hip reconstruction with exclusive internal devices is a technique in evolution with encouraging early results. It avoids common complications of external fixators and facilitates quick rehabilitation of joints. Refraining from distal varus can effectively eliminate Trendelenburg gait, although with some degree of lateral MAD. Unlike external fixation where there is a possibility of gradual correction, this staged procedure of internal fixation is technically demanding with a learning curve.

Clinical significance

Pelvic support hip reconstruction performed by internal implants is a viable alternative to Ilizarov hip reconstruction with potential benefits.

How to cite this article

Metikala S, Kurian BT, Madan SS, et al. Pelvic Support Hip Reconstruction with Internal Devices: An Alternative to Ilizarov Hip Reconstruction. Strategies Trauma Limb Reconstr 2020;15(1):34–40.

Relevant advances in bone lengthening research: a bibliometric analysis of the 100 most-cited articles published from 2001 to 2017

This study aimed to assess the scientific production of bone lengthening research by identifying the most-cited papers. All articles including the term 'bone lengthening' published between 2001 and 2017 were retrieved through the Web of Science database. The 100 most-cited articles on bone lengthening included a total of 4244 citations, with 414 (9.7%) citations in 2017. There was an average of 249.6 citations per year. The articles predominantly addressed biomechanics and bone formation (38). Different surgical techniques, including intramedullary nail (14), Ilizarov (nine), intramedullary skeletal kinetic distractor (ISKD) (six), Taylor spatial frame (6), the PRECICE device (three), and lengthening and submuscular locking plate (three), were the second most-studied topic. Most studies were therapeutic (58), whereas 30 studies were experimental investigations using animal models. Among the clinical studies, case series were predominant (level of evidence IV) (57). This study presents the first bibliometric analysis of the most relevant articles on bone lengthening. The list is relatively comprehensive in terms of identifying the top issues in this field. However, the most influential clinical studies have a poor level of evidence, although a slight tendency toward a better level of evidence has been observed in more recent years.

Bone reconstruction after malignant tumour resection using a motorized lengthening intramedullary nail in adolescents: preliminary results

PURPOSE

Bone reconstruction after malignant tumour of the lower limbs is a challenge. Our aim was to investigate the results of bone lengthening and transport using the Fitbone motorized lengthening nail.

METHODS

Eight patients were included. Two patients had had a tumour involving soft tissue only without bone resection. In six patients, the initial bone defect was 15.5 cm (8 to 24). The first step of reconstruction had consisted of temporary fixation and a cement spacer. The second step had consisted of bone grafting in five patients. One patient was managed with bone transport. Eventually, five patients had a limb-length discrepancy (LLD) managed with bone lengthening only. Two patients had a LLD and a nonunion managed with bone transport and lengthening. Mean age at bone lengthening was 15.2 years (11 to 19). Mean follow-up was 30.5 months (10 to 48).

RESULTS

In all, 11 nails were implanted in eight patients (eight femurs, three tibias). Mean length gain per procedure was 54.5 mm (30 to 80). Mean healing index was 48.4 days per cm (22.6 to 85.7). The complication rate was 18%. In two cases we observed a loose locking screw, which was revised. In all cases the lengthening involved the short bone (femur or tibia). Mean Musculoskeletal Tumor Society (MSTS) score improved from 52.7 (16.6 to 73.3) to 79.9 (63.3 to 96.6).

CONCLUSIONS

Bone reconstruction using a motorized intramedullary nail stands as a safe and reliable alternative after malignant tumour. It allows biological reconstruction with satisfactory clinical and radiological outcome and low complication rate.

LEVEL OF EVIDENCE

III.

Assessment of material loss of retrieved magnetically controlled implants for limb lengthening

Purpose: We aimed to understand wear from the telescopic component of PRECICE nails, which are used for distraction osteogenesis of the femur or tibia. We also aimed to identify any correlation between implant performance and patient factors. Methods: This retrieval study involved 11 magnetically controlled intramedullary nails from nine patients who had achieved the targeted leg length. All the nails were assessed macroscopically and microscopically for wear. All implants were radiographed to assess the internal mechanism. A Talyrond 365 (Taylor Hobson, Leicester, UK) roundness measuring machine was used to generate three-dimensional surface maps of the telescopic components to allow for measurement of wear. Results: Visual assessment of all the nails showed evidence of wear from the telescopic component. The radiographs revealed that all the nails had intact internal mechanism and no evidence of fractured pins. The roundness measuring machine showed that the quantity of wear was lowest in the latest design of the PRECICE nail. There was no significant correlation between wear and the two patient factors (duration of the lengthening phase, the time of implantation) included in this study. Conclusion: This study is the first to investigate the performance of the three different designs of the PRECICE system with a focus on wear. We found that the latest design had the best implant performance. We are confident of the continued success of the PRECICE system and reassure surgeons and patients that they are unlikely to encounter problems with the implant related to wear.

A new technique for correction of leg length discrepancies in combination with complex axis deformities of the lower limb using a lengthening nail and a locking plate

PURPOSE

Intramedullary lengthening nails are an accepted alternative to external fixators but are limited by anatomical preconditions. Therefore, to date the use of external fixators is sometimes inevitable. We report on a new technique for correction of combined limb length discrepancies and complex axis deformities using solely internal devices - a lengthening nail and a locking plate.

METHODS

Between October 2008 and November 2011 five patients (two femora, three tibias) with a mean leg length discrepancy of 36 mm (25 to 50) and a complex angular deformity were treated with a fully implantable motorized lengthening nail (Fitbone) and a locking plate. All patients were evaluated with regards to the pre- and postoperative leg length as well as axis alignment, functional outcome, lengthening indices and complications.

RESULTS

A successful leg length equalization was achieved in all cases and physiological joint orientation angles in all but one case. The mean distraction index was 1.2 mm/day, the maturation index 24 days/cm and the consolidation index 35 days/cm. The functional outcome was very encouraging in all cases with bilateral free range of movement. In total, two complications were observed, one nonunion and one loss of leg length after an early locking bolt removal in a peripheral hospital.

CONCLUSION

The combination of a fully implantable motorized lengthening nail and a locking plate is a valuable alternative option for treating selected cases with limb length discrepancies in combination with a complex deformity of the lower leg. However, the reported technique puts high demands on the preoperative planning, operative technique as well as surgeon's skills.

LEVEL OF EVIDENCE

IV (retrospective series).

Gain of length-loss of strength? Alteration in muscle strength after femoral leg lengthening in young patients: a prospective longitudinal observational study

This study aimed to determine the alteration in maximum isokinetic torque in patients after intramedullary femoral leg lengthening. Thirty patients with a median leg-length discrepancy of 3.0 cm underwent femoral limb lengthening with an intramedullary motorized device. Maximum isokinetic, concentric torque of the extensors, and flexors of the knee was measured before (n=30) and 2 years after surgery (n=21). Postoperatively, a significant difference remained for the maximum isokinetic torque of the extensors (22%) between the lengthened and the normal leg, which might have been caused by muscle response to the distraction procedure itself in the form of higher stiffness, less immediate displacement, and inconsistent force relaxation properties. However, we provide evidence that physiotherapy after limb lengthening should focus on extensors to prevent loss of strength.

Aneurysmal bone cyst healing response with intramedullary lengthening nail

We report the treatment process of a pediatric patient with deformity and shortening in the arm after a recurrent aggressive aneurysmal bone cyst (ABC) in the proximal humerus. The patient was treated with curettage of the lesion and lengthening on an intramedullary nail following an osteotomy just distal to the ABC. The period of lengthening was approximately 50 days. At the end of the treatment the lengthening goal was achieved without any neurovascular complication. There was a minimal loss in shoulder hyperabduction due to the deformity of the humeral head.

The role of the intramedullary implant in limb lengthening

Limb lengthening is now an accepted practice in orthopaedic surgery. The principles of distraction osteogenesis have become well established with the use of external fixators, utilizing both monolateral and ring fixators. Corticotomy technique, frame stability, lengthening rate and rhythm all contribute to the formation of bone regenerate and tissues. Complications are however common including pin-site infection, soft tissue tethering from the pins and wires resulting in pain, regenerate deformity from soft tissue forces or fracture following frame removal and patient intolerance of the frames during treatment. Surgical techniques have changed to try and minimise these complications. The use of intramedullary nails have been used in conjunction with an external fixator or inserted after lengthening has been achieved, to reduce fixator time and prevent regenerate deformity. Implant innovation has led to the production of intramedullary lengthening nails. The initial devices used ratchet mechanisms with rotation of the bone fragments to achieve lengthening (Bliskunov, Albizzia and ISKD). More accurate control of lengthening and a reduction in pain, resulting from the manual rotation of the leg required to achieve the ratchet progression, was achieved by the use of a transcutaneous electrical conduit powered by external high frequency electrical energy (Fitbone). The most recent implant uses an external remote controller which contains two neodymium magnets. These are placed over the nail on the skin and rotate which in turn rotates a third magnet within the intramedullary nail (Precice). This magnet rotation is converted by a motor to extend or retract the extendible rod. There are multiple nail sizes and lengths available, and early results have shown accurate control with few complications. With such promising outcomes the use of this lengthening intramedullary nail is now recommended as the implant of choice in femoral lengthening. This article is an historical account of the intramedullary device and the impact on limb lengthening.

Limb reconstruction after traumatic bone loss

A variety of options exist to reconstruct limbs following traumatic bone loss. The management of these injuries is challenging and often requires prolonged and potentially painful treatment. The Ilizarov technique of bone transport using circular external fixators is widely used for limb reconstruction of large bone defects. Other techniques include vascularised fibular grafting, the use of induced pseudosynovial membranes combined with cancellous autologous bone grafts and the use of autologous, allogeneic or synthetic bone grafts on their own for smaller defects. Future directions include further research on bone tissue engineering using stem cell therapy and growth factors such as bone morphogenetic proteins. The purpose of this Continuing Medical Education article is to describe the key limb reconstructive techniques that may be employed to treat traumatic bone loss. In particular, this article is intended to serve as a revision tool for those preparing for postgraduate examinations.

Femoral lengthening in children and adolescents

Current lengthening techniques are still based on the Ilizarov method and the concept of callotasis. Research and progress in medical devices have led to constant improvement in results. Hexapod fixators allow more precise correction of complex deformities, with shorter learning curve. Associating lengthening by external fixation (EF) to internal fixation (K-wire, intramedullary nail or locking plate) has reduced EF times and complications rates, while improving anatomic and functional results. Lengthening nails provides faster recovery of range of motion and return to activity during lengthening and consolidation, with better psychological tolerance. Lengthening with deformity correction by retrograde nailing has no impact on consolidation. Monolateral EF is a reliable and easy-to-implement technique that is well tolerated by patients. Association to internal fixation gives promising results. Bone healing solidity assessment on plain X-ray is highly subjective, with wide inter- and intra-observer variation; bone mineralization is better assessed in terms of pixel-value ratio (PVR: ratio of pixel value of regenerate to adjacent bone) on picture archiving and communication system (PACS) digitized radiographs, providing objective assessment of callus solidity.

Current approaches to flexible intramedullary nailing for bone lengthening in children

Limb-length discrepancies and extremity deformities are among the most common non-traumatic orthopaedic conditions for which children are hospitalised. There is a need to develop new treatment options for lower-limb length discrepancy in order to ameliorate treatment outcomes, avoid or reduce rates of complication and provide early rehabilitation. The authors report on the basic principles, experimental and clinical data, advantages, problems and complications of a combined technique associating the Ilizarov method and flexible intramedullary nailing (FIN) in limb lengthening and deformity correction in children. They describe features of the use of hydroxyapatite-coated intramedullary nails in patients with certain metabolic bone disorders and in cases where bone consolidation has been compromised. The advantages of bone lengthening using a combined technique (circular fixator plus FIN) are a lower healing index, quicker distraction-consolidation, a reduced rate of septic and bone complications, the ability to correct deformities gradually and the increased stability of bone fragments during the external fixation period and after frame removal.

Intramedullary lengthening nails: can we also correct deformities?

Unlike external fixators, the use of solid intramedullary lengthening nails is restricted to defined anatomical preconditions, such as an adequate bone length. Furthermore, all deformity corrections except the lengthening procedure have to be implemented intraoperatively and cannot be adjusted postoperatively. Conversely, even complex deformity corrections can be performed using intramedullary devices after a thorough preoperative planning. For preparation of the intramedullary cavity as well as positioning of the lengthening nail according to the preoperative planning, reaming the medullary canal with rigid reamers which don't follow the line of least resistance is inevitable. However, the application of solid lengthening nails might be limited, especially in children with ongoing epiphyseal growth, although a central perforation of the growth plate was shown to have no adverse effects on the growth potential. In cases with complex or multilevel deformities, an additional osteotomy and locking plate fixation could sometimes be a valuable solution in order to avoid external fixation. The low complication rate as well as the reduced compromising of soft tissues and periosteum render intramedullary lengthening nails the state-of-the-art procedure for limb lengthening in combination with deformity correction in patients who meet the anatomical preconditions.

Pitfalls in automatic limb lengthening - First results with an intramedullary lengthening device

BACKGROUND

The treatment of leg length discrepancy and deformities has become more common over the last few decades due to newly developed implants. Lengthening using fully implantable intramedullary nails provides many advantages; however, only little data is available. Therefore, we aimed to determine: (1) safety of the implant, (2) the complication rate and (3) functional outcome after magnetic driven intramedullary bone lengthening with a telescopic implant.

HYPOTHESES

Automatic bone lengthening with intramedullary nails provide good short-term outcome.

PATIENTS AND METHODS

Ten patients with limb length discrepancy of lower extremity, treated with an Ellipse PRECICE^® nail, were included in this retrospective follow-up study. The mean limb length discrepancy was 4.7cm (range: 2.5-7.0cm).

RESULTS

In all patients, limb lengthening goals were reached within a range of ±0.5cm after a mean time of 53 days. However, in 2 patients, mechanical failures with unintended shortening were observed. In a further patient nail breakage occurred. Overall, 7 patients presented with complications during the follow-up period.

DISCUSSION

The PRECICE^® nail represents a new, fully implantable, magnetically driven device for limb lengthening. However, due to a high rate of complications, a close follow-up is necessary to identify early implant failures and to avoid severe adverse outcomes.

LEVEL OF EVIDENCE

Retrospective follow-up study, case series, level IV.

Outcomes following femoral lengthening

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.

Patients and Methods

We reviewed all cases of simple femoral lengthening performed at our unit from 2009 to 2014. Cases of nonunions, concurrent deformities, congenital limb deficiencies and lengthening with an unstable hip were excluded, leaving 33 cases (in 22 patients; 11 patients had bilateral procedures) for review. Healing index, implant tolerance and complications were compared.

Results

In 20 cases (15 patients) the Precice lengthening nail was used and in 13 cases (seven patients) the LRS external fixator system. The desired length was achieved in all cases in the Precice group and in 12 of 13 cases in the LRS group. The mean healing index was 31.3 days/cm in the Precice and 47.1 days/cm in the LRS group (p < 0.001). This was associated with an earlier ability to bear full weight without aids in the Precice group. There were more complications with LRS lengthening, including pin site infections and regenerate deformity. Implant tolerance and the patients’ perception of the cosmetic result were better with the Precice treatment.

Conclusion

Femoral lengthening with the Precice femoral nail achieved excellent functional results with fewer complications and greater patient satisfaction when compared with the LRS system in our patients. Cite this article: Bone Joint J 2016;98-B:1382–8.

Complications in leg lengthening using an Ilizarov external fixator and intramedullary alignment in children: comparative study during a fourteen-year period

BACKGROUND

The purpose of this retrospective study was to evaluate the complications associated with leg lengthening in children treated with the Ilizarov external fixator (IEF) and compare them between two groups of patients: one group was treated using an IEF alone and the other group was treated using an IEF in association with intramedullary alignment (IA).

PATIENTS AND METHODS

The study was performed at the University Children's Hospital in Belgrade, Serbia during a fourteen-year period (from 2000 to 2014). Complications occurred in 73 paediatric patients who underwent the leg lengthening procedure. Complications were classified according to the Caton classification and compared between two groups. Group I comprised 39 patients who underwent the limb lengthening procedure using IEF alone. Group II consisted of 34 patients who were treated with the combination of IEF and IA using two Kirschner wires (K-wires) or Titanium Elastic Nails (TEN). The duration of hospital treatment was also compared between the two groups and the impact of the type of IA on the occurrence of complications was assessed.

RESULTS

There was a high rate of complications in patients treated using an IEF compared with those treated using the combination of IEF and IA, but there was no statistically significant difference between the two groups. There was a statistically significant difference in the duration of initial hospitalisation between the two groups, particularly when comparing TEN usage in IA. A comparison of the group of patients treated using an IEF in association with K-wires and patients treated using IEF and TEN showed there was no statistically significant difference in complication rate and duration of initial hospitalisation.

CONCLUSION

IA has multiple advantages as a method of treatment of leg length inequality. The major effect of applying IA in association with a circular IEF is significantly reduced complication rate and duration of initial hospitalisation, particularly when using TEN as a method of IA. This method of treatment also decreases hospital costs.

Lengthening in Congenital Femoral Deficiency: A Comparison of Circular External Fixation and a Motorized Intramedullary Nail

BACKGROUND

Circular external fixation for limb-lengthening is associated with frequent and numerous complications. Intramedullary lengthening devices represent a potential advance in limb-lengthening. The purpose of this study was to compare the outcomes of femoral lengthening in pediatric patients treated by either circular external fixation or a motorized intramedullary nail.

METHODS

All patients with a diagnosis of congenital femoral deficiency who had undergone femoral lengthening with either circular external fixation or a motorized intramedullary nail were identified. The motorized intramedullary nail (FITBONE) was used with approval of the U.S. Food and Drug Administration on an individual compassionate-use basis.

RESULTS

Fourteen skeletally mature patients underwent fourteen femoral lengthening sessions using circular external fixation, and thirteen patients underwent fifteen lengthening sessions using the motorized nail. The amount lengthened was similar, with a mean of 4.8 cm (range, 1.0 to 7.4 cm) in the circular fixation group and 4.4 cm (range, 1.5 to 7.0 cm) in the motorized nail group. Complications occurred in all lengthening sessions in all fourteen patients managed with the circular external fixation and in 73% of fifteen lengthening sessions in the thirteen patients managed with the motorized nail. The circular external fixation group averaged 2.36 complications per lengthening session compared with 1.2 per session in the motorized nail group. Twenty-nine percent of the circular fixation group failed to achieve a lengthening goal of at least 4 cm compared with 27% of the motorized nail group who failed to reach the goal. Eight patients had undergone eleven femoral lengthening sessions with circular external fixation prior to undergoing ten lengthening sessions by motorized nail. These patients had a comparable rate of complications with both types of lengthening, but the total number of complications averaged 2.6 per lengthening session with circular external fixation compared with 1.6 per lengthening session with the motorized nail.

CONCLUSIONS

A decreased number of complications was noted with use of a motorized intramedullary nail compared with circular external fixation in pediatric patients undergoing femoral lengthening for congenital femoral deficiency.

LEVEL OF EVIDENCE

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

PRECICE intramedullary limb lengthening system

The PRECICE(®) Intramedullary Limb Lengthening System (Ellipse Technologies Inc., CA, USA) is a remotely controlled, magnetically driven, implantable limb lengthening intramedullary nail system. It has both CE mark and US FDA clearance for its first- (2011) and second-generation (2013) implants. It is indicated for the treatment of limb length discrepancy and short stature. It has been used worldwide in over 1000 cases. Its reported and published results in over 250 cases has been excellent with less pain and lower complication rates than with external fixation methods or previous implantable nail systems.

Tibial lengthening with a submuscular plate in adolescents

BACKGROUND

Lengthening over an intramedullary nail has become a common technique for reducing the period of external fixation. However, the technique presents difficulties in patients with an open physis or a small marrow canal. Lengthening using a submuscular plate offers a new substitute in such situations, but few studies have been undertaken to determine its efficacy in teenagers.

PATIENTS AND METHODS

A retrospective review was performed on 20 consecutive tibiae of 16 patients who underwent tibial lengthening with the aid of external fixator and submuscular plate. Charts and radiographs were reviewed for demographics, surgical details, and complications related to the technique.

RESULTS

The average age of the 16 patients was 14.3 years (range 10-17), and the amount of lengthening averaged 4.1 cm (range 3.0-5.0 cm), which represented 12.7 % of preoperative bone length (range 9.1-15.8 %). Mean time in the fixator was 60.3 days, mean external fixation index was 14.8 days/cm (range 13.2-22.5 days/cm), and mean healing index was 49.1 days/cm (range 37-59.3 days/cm). Twenty-seven complications occurred giving an overall complication rate of 1.35. Twenty of the 27 were minor complications, but 7 were major. These major complications were resolved surgically or by a resolution period exceeding 3 months. There were 3 cases of transient angular deformity of distraction callus, 2 cases of transient peroneal nerve palsy, 1 case of clamp loosening, and 1 case of plate failure. Functional results were good or excellent with an average score of 95.6 according to modified Paley's criteria.

CONCLUSIONS

Although complications were not uncommon, tibial lengthening with a submuscular plate proved to be a reliable technique for treating limb length discrepancy in adolescents with reduced external fixation duration.

LEVEL OF EVIDENCE

Level IV, case series.

Complications of the Intramedullary Skeletal Kinetic Distractor (ISKD) in distraction osteogenesis

BACKGROUND

The Intramedullary Skeletal Kinetic Distractor (ISKD) (Orthofix Inc, Lewisville, TX, USA) is an intramedullary device designed for more comfortable limb lengthening than that with external fixators; lengthening is achieved with this nail using rotational oscillation between two telescoping sections. However, the degree to which this device achieves this goal and its complication rate have not been fully documented.

QUESTIONS/PURPOSES

We determined (1) the frequency with which distraction was not achieved at the desired rate, (2) whether pain differed between patients with normally and abnormally distracting nails, (3) risk factors for abnormal nails, and (4) other complications.

METHODS

We analyzed 35 lengthening segments (26 femurs, nine tibias) in 19 patients. Mean length achieved was 47 mm. Femoral nails were categorized into four groups according to distraction rate: normal, runaway (unintentionally faster rate [> 1.5 mm/day]), difficult-to-distract (slower rate [< 0.8 mm/day] requiring manual manipulation but not requiring general anesthesia), and nondistracting (slower rate [< 0.8 mm/day] requiring manual manipulation under general anesthesia or reosteotomy). Possible risk factors, including age, BMI, preoperative thigh circumferences, degree of intramedullary overreaming, and length of the thicker portion of the nail within the distal fragment, were compared among groups. VAS pain scores were compared among groups under three conditions: rest, physiotherapy, and distraction motion. Complications were also analyzed. Minimum followup was 15 months (mean, 26 months; range, 15-38 months) after first-stage surgery.

RESULTS

Abnormal distraction rate was observed in 21 of 35 segments (60%; 17 femurs, four tibias). VAS pain scores showed no differences among groups during rest or physiotherapy but were higher (p = 0.02) in the problematic nails (7-8 points) versus normal nails (3 points) during distraction. Only mean length of the thicker portion of the nail within the distal fragment differed between normally and abnormally distracting nails (95 mm versus 100 mm; p = 0.03), although this was unlikely to be clinically important. Complications occurred in 10 patients (53%), including five with decreased ankle ROM during distraction, four with delayed bone healing, and one with mechanical device failure during distraction.

CONCLUSIONS

Rate control was difficult to achieve with the ISKD nail for femoral and tibial lengthenings, complications were relatively common, and among patients in whom rate control was not achieved, pain levels were high. Based on our findings, we believe that surgeons should avoid use of this nail.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Precision of the PRECICE internal bone lengthening nail

BACKGROUND

Previous designs of internal bone lengthening devices have been fraught with imprecise distraction, resulting in nerve injuries, joint contractures, nonunions, and other complications. Recently, a magnet-operated PRECICE nail (Ellipse Technologies, Inc, Irvine, CA, USA) was approved by the FDA; however, its clinical efficacy is unknown.

QUESTIONS/PURPOSES

We evaluated this nail in terms of (1) accuracy and precision of distraction, (2) effects on bone alignment, (3) effects on adjacent-joint ROM, and (4) frequency of implant-related and non-implant-related complications.

METHODS

We reviewed medical and radiographic records of 24 patients who underwent femoral and/or tibial lengthening procedures using the PRECICE nail from August 2012 to July 2013 for conditions of varied etiology, the most common being congenital limb length discrepancy, posttraumatic growth arrest, and fracture malunion. This group represented 29% of patients (24 of 82) who underwent a limb lengthening procedure for a similar diagnosis during the review period. At each postoperative visit, the accuracy and precision of distraction, bone alignment, joint ROM, and any complications were recorded by the senior surgeon (SRR). Accuracy reflected how close the measured lengthening was to the prescribed distraction at each postoperative visit, while precision reflected how close the repeated measurements were to each other over the course of total lengthening period. No patients were lost to followup. Minimum followup from surgery was 3 weeks (mean, 14 weeks; range, 3-29 weeks).

RESULTS

Mean total lengthening was 35 mm (range, 14-65 mm), with an accuracy of 96% and precision of 86%. All patients achieved target lengthening with minimal unintentional effects on bone alignment. The knee and ankle ROM were minimally affected. Of the complications requiring return to the operating room for an additional surgical procedure, there was one (4%) implant failure caused by a nonfunctional distraction mechanism and six (24%) non-implant-related complications, including premature consolidation in one patient (4%), delayed bone healing in two (8%), delayed equinus contracture in two (8%), and toe clawing in one (4%).

CONCLUSIONS

We conclude that this internal lengthening nail is a valid option to achieve accurate and precise limb lengthening to treat a variety of conditions with limb shortening or length discrepancy. Randomized, larger-sample, long-term studies are required to further confirm clinical efficacy of these devices, monitor for any late failures and complications, and compare with other internal lengthening devices with different mechanisms of operation.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Derotational femoral osteotomy technique with locking nail fixation for adolescent femoral antetorsion: surgical technique and preliminary study

Rotational femoral osteotomies for excessive femoral antetorsion may be considered only for symptomatic adolescents. Our main objective was to describe our femoral osteotomy technique. Preoperative planning was performed clinically and with the EOS imaging system. Percutaneous osteotomy was performed on distal femoral metaphysis under radioscopic control. Fixation was achieved with an antegrade locking nail. Rotation was checked precisely using a specially designed protractor before distal locking. We carried out a prospective pilot study between 2009 and 2010 on six patients (nine procedures). All the patients included presented a symptomatic femoral antetorsion greater than 20°. Clinical parameters including range of hip mobility and femoral antetorsion were measured every 2 months during the first 6 months, and then every year until skeletal maturation was reached. We obtained orthoroentgenograms using the same technique at each follow-up and torsional analysis by EOS 3D Imaging at 6 months. The average correction of the femoral antetorsion was 19.0 ± 4.0° (range, 13-25°). The average time of union was 3 ± 1.2 months (range, 2-6 months). Patients returned to full weight bearing at an average of 2.6 ± 0.4 months (range, 2-4 months). One patient experienced an early secondary displacement in varus for which a reoperation was required. We believe that this technique can accurately achieve derotational femoral osteotomies. A study is ongoing to evaluate the clinical results of this technique including mechanical and cosmetic advantages.

Experimental assessment of a novel intramedullary nail for callus distraction by the segmental bone transport method

BACKGROUND

Segmental bone transport (SBT) is a revolutionary method for treating extensive bone defects, and it is in wide clinical use. Although external fixation is generally used to perform SBT, it is associated with problems such as complications due to pin placement and limitations of the amount and rate of lengthening. As a way to overcome these problems we developed a novel intramedullary (IM) nail for SBT that minimizes damage to the surrounding tissue and improves the amount and rate of bone lengthening. The purpose of this study was to perform SBT in the femur of beagle dogs using the novel IM nail that we devised, and to evaluate the morphology and quality of the regenerated bone and circulation status in the surrounding tissue. We also considered the possibilities and limitations of the IM in regard to clinical application.

METHODS

This experiment was conducted on six beagle dogs. The novel IM nail we devised was inserted into the marrow cavity of the femur, and a 30-mm bone defect was created. After a 7-day postoperative waiting period, a bone segment was transported by 1.0 mm per day in two 0.5-mm increments. Because the nail broke in two dogs, they received only partial elongation by 15 mm over a 15-day period, with a 15-mm defect remaining, whereas full elongation by 30 mm in 30 days was performed in the other four dogs. The elongation was followed by a 30-day bone hardening period.

RESULTS

The macroscopic and histological results demonstrated that high-quality, new bone had replaced the 30-mm bone defect created in the femur of all six dogs. The density and number of blood vessels that had penetrated the elongated segment of bone from the surrounding muscles was greater than in the corresponding segment of the contralateral femur, which served as a control. The results imply that the traction stimulus induced vigorous angiogenesis in the surrounding tissue.

CONCLUSION

We concluded that this method has tremendous potential for clinical application, and will overcome the limitations of conventional external fixators.

Limb shortening osteotomy in a patient with achondroplasia and leg length difference after total hip arthroplasty

Introduction:

Achondroplasia is the most common reason for disproportionate short stature. Normally, orthopedic limb lengthening procedures must be discussed in the course of this genetic disorder and have been successful in numerous achondroplastic patients in the past. In some cases, the disease may lead to leg length differences with need for surgical correction.

Case Report:

We report a case of achondroplastic dysplastic coxarthrosis with symptomatic leg length difference after bilateral total hip arthroplasty in a 52-year-old female patient, in which a distal femoral shortening osteotomy was successfully performed.

Conclusion:

Femoral shortening osteotomy is very uncommon in patients with achondroplasia. We conclude, however, that in rare cases it can be indicated and provide the advantage of shorter operation time, less perioperative complications and faster recovery compared to leg lengthening procedures.

Current concepts of leg lengthening

Any lower limb discrepancy may be equalised by conservative means (insoles, prosthesis and orthosis). However, their long-term acceptance is low in regard to function, costs, expenditure and appearance. Timely epiphysiodesis is the best option in uniplanar deformities with adequate remaining growth and for patients whose predicted final body height is above the 50th percentile. However, many patients present late or with multi-planar deformities, which warrant more sophisticated operative approaches. The history of surgical bone lengthening comprises 100 exciting years of struggling, development and ongoing learning. The initial strategy of acute or rapid incremental distraction had lasted almost half a century until Ilizarov recognised the benefits of biological periosteum-preserving osteotomies and incremental lengthening at slow rates (1 mm/day) at a 4 × 0.25-mm daily rhythm, well appreciated as callotasis. In parallel, ring and wire constructs made complex three-dimensional axial, translational and rotational bone moulding possible. Taylor Spatial Frames-built on hexapod strut-linked platform technology as known from flight simulators-took limb correction to a more reliable, more precise and aesthetical level, all the more that the whole process became web-based. It represents state-of-the-art methodology and technology for complex, multi-plane deformities. Due to the significant risk of secondary malalignment, indications for lengthening by unilateral fixation have shrunken to moderate amounts of length disparity and uni- to bi-planar deformities in patients with still open physes. Mechanical or motorised, minimally invasively placed nails prevent muscle fixation and, therefore, ease rehabilitation, increase patient comfort and potentially shorten the overall time of sick leave and refrain from sports activities. Hence, they offer a valuable alternative for low-grade complexity situations. It remains to be proved if the significantly higher implant costs are compensated by lower treatment costs. Overall, limb lengthening, particularly in combination with multi-planar deformity correction, can still be an arduous endeavour. In any case, wise judgement of the patient's deformity, medical and biological situation, psychosocial environment, selection of the appropriate method and hardware, as well as meticulous operating technique by an experienced surgeon are the cornerstones of successful outcomes.

[Intramedullary motorized nail for equalization of posttraumatic leg length discrepancies]

BACKGROUND

Fractures in childhood may result in a significant leg length discrepancy (LLD). The common correction method of LLD and deformities is callotasis with external fixation. This is often associated with pain, pin site infection, muscle tethering and reduced range of movement (ROM).

PATIENTS AND METHODS

Between 2006 and 2008 a total of 11 cases of posttraumatic LLD (range 2.4-4.3 cm) were treated with a fully implanted motorized lengthening device (Fitbone®). Hospitalization time, leg equalization, rehabilitation time and complications compared to external fixation were recorded.

RESULTS

Leg lengthening was successfully performed in all cases, in five combined with angular and/or rotatory corrections. The mean distraction index was 1.03 mm/day (range 0.6-1.2 mm/day) and the mean consolidation index was 40 days/cm (range 25.2-50.9 days/cm). The average hospital stay was 9.8 days (range 8-20 days). Bone or soft tissue infections were not observed, nor were the complications commonly associated with external fixation. Functional results were excellent as the preoperative knee ROM was regained in all cases and with improved ROM in three cases.

CONCLUSION

The Fitbone® nail is a valuable alternative to conventional methods which reduces complications commonly associated with external fixation.

Development of a Force-Driven Distractor for Distraction Osteogenesis

Distraction osteogenesis is a routine surgical procedure to lengthen a long bone. A fixed lengthening rate is typically used. We investigate measuring forces continuously and producing a variable distraction rate. A motorized distractor was instrumented with a load cell to measure the forces developed in a limb during distraction osteogenesis. The motor moves 2.6 μm at each step, with a variable frequency depending on the distraction rate. The forces were measured every 15 s and used to change the rate on the autodistractor. The autodistractor, load cell, data logger, controller, and battery pack were all mounted on a monolateral rail fixator, which was tested on a sheep that underwent tibial lengthening. Results show the feasibility of continually recording forces in vivo. The lengthening rate changed automatically, based around a threshold force of 300 N. Findings indicate that force readings are feasible and practical with a simple device. Force determination may provide an additional means to evaluate tissue integrity in real-time and away from the clinic. An automatic variable rate device could improve limb lengthening.

Intramedullary leg lengthening with a motorized nail

BACKGROUND AND PURPOSE

In the last decade, intramedullary limb lengthening has become a viable alternative to traditional external systems. We retrospectively analyzed the use of an intramedullary motorized nail (Fitbone) in a consecutive series of 32 patients.

PATIENTS AND METHODS

During the period September 2006 to December 2008, 32 consecutive patients with a median age of 17 (IQR: 15-19) years were treated with a fully implantable, motorized intramedullary lengthening device (Fitbone). The median leg length discrepancy was 35 (IQR: 30-44) mm at the femur (n = 21) and 28 (IQR: 25-30) mm at the tibia (n = 11).

RESULTS

Leg lengthening was successful in 30 of 32 cases, with no residual relevant discrepancy (± 5 mm). No intraoperative complications were observed. The consolidation index was significantly different (p = 0.04) between femoral lengthening (mean 35 days/cm) and tibial lengthening (mean 48 days/cm) but did not depend on age older/younger than 16 or previous operations at the affected site. 3 problems, 3 obstacles, and 4 complications (3 minor, 1 major) were encountered in 8 patients, 5 of which were implant-associated.

INTERPRETATION

This technique even allows correction in patients with multiplanar deformities. Compared to external devices, intramedullary systems provide comfort and reduce complication rates, give improved cosmetic results, and lead to fast rehabilitation since percutaneous, transmuscular fixation is prevented. This results in reasonable overall treatment costs despite the relatively high costs of implants.

Flexible intramedullary nail use in limb lengthening

BACKGROUND

The aim of this study is to evaluate the influence of the external fixation associated with flexible intramedullary nailing (FIN) on the healing index (HI) in limb lengthening.

METHODS

We compared the healing index between 2 groups of children undergone the lengthening of upper and lower limbs carried out with the Ilizarov external fixator alone (group I, 194 cases of lengthening) or with the combination of the Ilizarov external fixator and intramedullary nailing (group II, 92 cases). Two nails of the diameter from 1.5 to 2.0 mm with the ray of curvature about 40 degrees to 50 degrees were used for the intramedullary nailing.

RESULTS

The HI was less in every subgroup of Group II compared with Group I. A significant difference was noted in congenital pathologies: monofocal monosegmental lengthening at the level of femur and forearm, bifocal lengthening of the tibia, polysegmental lengthening; and in acquired discrepancy: monofocal tibial lengthening, bifocal femoral lengthening, and the forearm lengthening. The reduction of HI was between 60% and 85% in congenital pathologies: monosegmental femur and forearm, bifocal femur and tibia lengthening; and in acquired discrepancy: femur, tibia, humerus and forearm monosegmental lengthening, humerus and tibia bifocal lengthening, and polysegmental in upper and lower limbs. This difference varies from 1.9 days/cm to 19.1 days/cm. That means that the duration of the external fixator was decreased of 20% to 33% of the number of days between the Group I and the Group II. Maximum diminution of HI was noted for monofocal acquired forearm cases (51.3%) and bifocal acquired femoral lengthening cases which (59.9%).

CONCLUSIONS

The flexible intramedullary nailing allows adding multiple advantages to the method of limb lengthening with the external fixator. Correctly applied the FIN indeed respects the bone biology that is essential during the limb lengthening. The major effect of application of the combination of Ilizarov frame fixation with FIN is a significant decrease of duration of the external osteosynthesis.

LEVEL OF EVIDENCE

II.

Ilizarov hip reconstruction without external fixation: a new technique

PURPOSE

The Ilizarov hip reconstruction is a well accepted but complication-prone operative salvage procedure in chronically dislocated hips, not least due to the long-term application of external fixation. Although the advantages of fully implantable devices are well known in limb lengthening and are described consistently, until now, external fixation has been used exclusively to perform the Ilizarov hip reconstruction procedure. We present a new technique of Ilizarov hip reconstruction with purely internal implants.

METHODS

A 14-year-old girl with a history of spina bifida presented with a 4-cm-short right leg, a Trendelenburg gait and a complex neurological disease expression. Because of refusal of external fixation by the patient and significantly lower complication rates, an Ilizarov hip reconstruction without external fixation was performed. A locking compression plate was applied to fix the proximal femoral valgus-extension osteotomy and a motorised intramedullary distraction nail was used for the distal, lengthening-varisation osteotomy.

RESULTS

A healing index of 33 days/cm and full weight bearing after 6 months were noted. At the 1 year follow-up, the patient showed an improvement of the Trendelenburg gait, as well as successful leg equalisation. Satisfaction to a high degree was additionally noted by factors such as reduced pain, the ability to wear workaday clothes and cosmetically appealing scars. No complications were recorded.

CONCLUSION

The exclusive use of internal implants for Ilizarov hip reconstruction is a feasible and patient-friendly alternative to traditional methods. Their use, however, may be restricted by geometric preconditions.