Limb salvage reconstruction of the lower limb with complex ankle arthrodesis and magnetic internal lengthening nail.

PURPOSE: With advances in orthopedic implants, the use of intramedullary lengthening devices has gained increasing popularity as an alternative technique compared to lengthening with external fixators, with alleged comparable or better outcomes. The aim of this study is to report our single-center technique and outcomes of combined ankle arthrodesis and proximal tibial lengthening using external fixator with a motorized intramedullary nail, respectively. METHOD: Fourteen patients with post-traumatic advanced ankle arthritis underwent staged ankle arthrodesis with external fixator and proximal tibial lengthening using the PRECICE® ILN. Amount of shortening, length achieved, bone healing index, infection rate, ankle fusion rate, and ASAMI score were evaluated. RESULTS: The average age was 44 years old (range, 30-62). The mean follow up is 70 months (range, 43-121.4). The average amount of limb shortening for patients after ankle fusion was 36.7 mm (18-50) while lengthening was 35.9 mm (range, 18-50). Patients had the nail implanted for an average of 479 days (range, 248-730). Ankle fusions were healed in an average of 178.3 days. There were no surgical infections. All osteotomy-lengthening sites healed after an average 202 days (106-365). The mean bone healing index (BHI) was 56.0 days/cm (21.2-123.6) among the whole cohort. There were no cases of nonunion. ASAMI bone scores were excellent or good among all patients. CONCLUSION: Ankle arthrodesis with external fixation along with proximal tibial lengthening using motorized IMN yielded high rates of fusion and successful lengthening. This technique could be offered as a reasonable alternative to using external fixation for both purposes. LEVEL OF EVIDENCE: Level IV, Retrospective cohort study.

Clinical compatibility of magnetic resonance imaging with magnetic intramedullary nails: a feasibility study.

INTRODUCTION: The use of magnetic resonance imaging (MRI) with a magnetic intramedullary lengthening nail in place is contraindicated per the manufacturer due to the concern of implant activation and migration. A prior in vitro study did not confirm these complications only noting that a 3.0 T MRI weakened the internal magnet. Therefore, a retrospective analysis of patients who underwent an MRI with a magnetic nail in place was performed to determine if any adverse effects occurred in the clinical setting. MATERIALS AND METHODS: A retrospective review of all patients who underwent an MRI with a magnetic lengthening nail in place was performed. The time spent being imaged in the MRI, number of times the patient entered the MRI suite, and the images obtained were recorded. Radiographs were performed before and after the MRI to determine if any hardware complications occurred. The patients were monitored for any adverse symptoms while they were in the suite. RESULTS: A total of 12 patients with 13 nails were identified. Two patients underwent imaging with a 3.0 T MRI while the remaining 10 underwent imaging with a 1.5 T MRI. Each patient entered the MRI suite 2.1 times and spent an average of 84.7 min being imaged in the MRI (range 21-494). No patients noted any adverse symptoms related to the nail while in the suite and no hardware complications were identified. CONCLUSION: MRI appears to be safe with a magnetic nail in place and did not result in any complications. Given the manufacturer's recommendations, informed consent should be obtained prior to an MRI being performed and a 3.0 T MRI should be avoided when possible if further activation of the nail is required.

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

Aims: The Precice Stryde® internal magnetic lengthening nail allowed many patients a full weight-bearing experience during femur and tibia lengthening, but concerns over corrosion, pain and radiographic changes led to the implant's recall. Despite the recall, it is important to understand the rate of these occurrences and their influence on the overall success of the lengthening procedure. We aimed to investigate radiographic changes, patient-reported symptoms and bone healing indices for our cohort of Stryde lengthening. Materials and methods: Our surgical database and electronic medical record system were used to review and document patient demographics, indications for lengthening, length achieved, bone healing index (BHI), location and type of radiographic changes, time until radiographic changes were first visible, presence of pain symptoms (not attributable to surgery or distraction), time to implant removal and if the pain symptoms resolved following implant extraction. Results: From January 2019 to February 2021, 90 Stryde nails (78 femur and 12 tibia) were implanted in 63 patients. The cohort included 48 males and 15 females. The average length [± standard deviation (SD)] achieved was 58.4 ± 22.7 mm. The 66 bones (73%) developed radiographic changes and were found to be 58/78 (74%) femurs and 8/12 (67%) tibias. The average time to initial radiographic changes was 168 ± 108.1 days (femur) and 276 ± 126.8 days (tibia). Late-onset pain developed in 10 femur lengthening (11.1% of all nails) surgeries across eight patients (12.7% of all patients). All patients' pain resolved; three instances prior to nail removal and the remaining seven after nail removal. No patients were re-presented with worsening pain or radiographic changes following implant removal. Radiographic or symptomatic abnormalities did not impair bone formation. The BHI for femurs with (29.6 ± 16.6 days/cm, n = 58) vs without (29.4 ± 17.9 days/cm, n = 20) radiographic or symptomatic irregularity were nearly identical (p = 0.961). The difference between BHI for tibias with (39.3 ± 7.8 days/cm, n = 8) vs without (86.1 ± 38.2 days/cm, n = 4) radiographic changes was influenced by outliers and underpowered to draw a conclusion. Conclusion: Bone lengthening with the Stryde nail was associated with high rates of radiographic abnormalities, but symptoms were uncommon and resolved with explantation. The radiographic changes did not affect bone healing in the femur. Clinical significance: Radiographic changes including bone hypertrophy and osteolysis were common after bone lengthening with the Stryde nail, but the development of pain following consolidation was rare and resolved with implant removal.The BHI in femurs was not affected by radiographic changes. How to cite this article: Reif TJ, Geffner A, Hoellwarth JS, et al. Precice Stryde® Magnetic Internal Lengthening Nail does not Impair Bone Healing Despite Radiographic and Clinical Symptoms. Strategies Trauma Limb Reconstr 2023;18(2):94-99.

Breakage of a re-activated PRECICE® nail: A case report.

INTRODUCTION AND IMPORTANCE: Distraction osteogenesis using motorized nails have shown promising results. These high-priced nails are regularly removed following successful lengthening sessions. The internal lengthening mechanism inside such nails is presumably intact and perhaps capable of running additional lengthening. Motorized nails are relatively weaker than conventional nails. This case report presented a broken re-activated PRECICE nail which has not been previously reported. PRESENTATION OF CASE: A 21-year-old male patient with right short tibia. He has completed an uneventful lengthening session using tibial PRECICE® nail. A residual length discrepancy persisted despite 4 cm length gain. Attempt of re-lengthening was conducted utilizing the pre-implanted PRECICE® nail. The re-lengthening session run smoothly throughout distraction phase. Late in the consolidation phase, partial nail breakage occurred. The patient acknowledged intermittent gentle weightbearing against the physician's recommendations. The broken nail was removed on emergency basis. Cast immobilization with non-weightbearing continued until achievement of full consolidation clinically and radiographically. CLINICAL DISCUSSION: Most of commercially available lengthening motorized nails are considered less rigid compared to conventional nails and hence more susceptible to deformation and metal failure. However, nail breakage has been reported in both conventional and lengthening nails. Re-activation of PRECICE nail for additional lengthening session could carry higher risk of breakage. CONCLUSION: Possibility of nail breakage may be higher in re-activated PRECICE® nails relative to newly implanted PRECICE® nails. More studies are required to evaluate behavior of re-activated lengthening nails. Defective lengthening nails must not be re-activated. The patient compliance is essential for successful re-activation of lengthening nails.

Comparison of forces generated using compression plating versus a magnetic lengthening nail in a sawbones femur model.

BACKGROUND: The purpose of this study is to compare compression generated by a Precice magnetic lengthening intramedullary nail and a 5.0 mm limited contact dynamic compression plate. METHODS: Transverse osteotomy sites were created in the femoral shaft of ten Sawbones fourth generation composite femurs. Antegrade 10-degree trochanteric Precice nails and 8-hole, 5.0 mm plates were used for fixation. The plates were compressed by placing a neutral screw and three eccentrically drilled compression screws on alternating sides of the osteotomy. Average compression and distribution of compression were compared, and P-values <0.05 were considered statistically significant. FINDINGS: The Precice nail generated an average of 2.38 megapascal across the osteotomy sites. The plate generated an average of 0.70 megapascal (P < 0.001) with the initial compression screw, 0.93 megapascal (P < 0.001) after the second screw, and 1.04 megapascal (p < 0.001) after the final screw. The distribution of compression was assessed utilizing a polar transformation to compare pressure values. We found that the distribution of compression was more circumferentially uniform in the Precice nail group (P = 0.046). INTERPRETATION: This study demonstrates that an electromagnetic intramedullary device is capable of generating significantly higher compression, in a more uniform distribution, than a 5.0 mm limited contact dynamic compression plate in a Sawbones model. The results indicate that electromagnetic intramedullary nail systems may be an ideal alternative to compression plating for treatment of at-risk fractures, nonunions, delayed unions, and intercalary allograft reconstruction.

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.

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.

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.

Early outcomes of magnetic intramedullary compression nailing for humeral fractures.

PURPOSE: The optimal treatment protocol for humeral shaft fractures at risk for nonunions is controversial. Here, we aim to describe magnetic intramedullary compression nailing as an option for these challenging scenarios and to evaluate its clinical and radiographic outcomes. METHODS: This retrospective case series was performed at an urban university-based level-1 trauma center. Patients aged 18-65 who underwent fixation of their at-risk humerus shaft fracture using the PRECICE nail were included in this investigation. These fractures are characterized by a persistent distraction gap, minimal callous formation, or malalignment greater than 20 degrees. The study data were collected through a retrospective chart review and review of the radiographic studies. Primary outcome measure was radiographic union. Secondary outcome measures included mechanical failure, nonunion, malunion, medical, and surgical complications. Functional outcome was determined by range of motion and restoration of rotator cuff strength. RESULTS: A total of six patients were included who underwent treatment of their humeral shaft fracture with a NuVasive PRECICE nail after failure of conservative management. After nail placement along with our compression protocol, all patients achieved bony union and experienced favorable outcomes with return to their previous working status. Two complications included a superficial incisional infection treated with antibiotics and a backing out of proximal screw which did not cause discomfort. No other mechanical failures, surgical complications, or medical complications occurred. CONCLUSIONS: Early results of controlled compression nailing for humeral shaft fracture demonstrated favorable clinical outcomes. This technique may be utilized for these challenging situations.

Humeral Lengthening with the PRECICE Magnetic Lengthening Nail.

BACKGROUND: Different types of external fixators have been used for humeral lengthening with successful outcomes reported in literature. Motorized intramedullary (IM) lengthening nails have been developed as an alternative to external fixators for long bone lengthening in the lower extremity. QUESTIONS/PURPOSES: This case series reports on using the new technology of IM lengthening nails for humeral lengthening. We assessed the radiological healing and functional outcomes after using the PRECICE IM nail for humeral lengthening. METHODS: This multicenter retrospective study included a total of six humeri in five patients (mean age was 20 years) that underwent lengthening with the magnetic IM PRECICE nail in two centers in the USA. The etiology was humeral growth arrest post-bone cyst (two segments), post-septic growth arrest (two segments), and multiple hereditary exostosis (bilateral segments in one patient). The outcomes measured were the length achieved, distraction index (DI; the length achieved in mm divided by the duration of lengthening in days), consolidation index (CI; number of days from surgery until consolidation divided by the length of the regenerate in cm), complications encountered, and functional outcomes (shoulder and elbow range of motion, the upper extremity functional index (UEFI), and QuickDASH functional scores). RESULTS: The mean follow-up period was 1.8 years (0.9 to 2.4 years). All segments achieved the goal of lengthening; the mean was 5.1 cm (4.5 to 5.8 cm). Mean DI was 0.7 mm/day (0.5 to 0.8). Mean CI was 36 days/cm (25 to 45 days/cm). No complications were observed. At the last follow-up, all patients maintained their preoperative range of motion (ROM) except one patient had reduced shoulder ROM. QuickDASH score and upper extremity functional index showed postoperative improvement compared to the preoperative scores. CONCLUSION: IM lengthening nails can provide successful and safe humeral lengthening. Specifically, the PRECICE nail has accurate control over the lengthening process.

Intramedullary magnetically actuated limb lengthening in a patient with congenital humeral limb shortening.

The treatment of leg length discrepancy has become a common procedure in orthopaedic surgery. However, lengthening of humeral deformities is still infrequent. The purpose of this case report was to present humeral lengthening with a new intramedullary lengthening device (PRECICE® P2 for tibia) in a 32 year old female patient with congenital shortening. Hereby the telescopic device presents a promising tool for humeral limb lengthening with excellent outcome at short-term in this case.

Unusual complication with an intramedullary lengthening device 15 months after implantation.

The treatment of leg length discrepancy and deformities has become more important over the last decades due to newly developed implants. Several different devices have been presented with various complications reported in literature. The purpose of this case report was to present an unusual complication 15 months after implantation of an intramedullary lengthening device (PRECICE(®)). An intramedullary lengthening device (PRECICE(®) P1 nail) was implanted in a 74 years old male patient with a congenital leg length discrepancy in January 2014. After bone lengthening of 6cm and obvious radiological callus formation a nail breakage with severe deformity occurred 15 months after implantation. Physicians have to be aware of the risk of such late complications regarding this device with serious implications for the patient.