Mechanical Failures in Magnetic Intramedullary Lengthening Nails.

BACKGROUND: Magnetic intramedullary lengthening nails (MILNs) have gained popularity in recent years for the treatment of limb-lengthening discrepancies. We sought to catalog mechanical failures and their prevention and management in a large, single-institution series. We specifically assessed the rate of mechanical failures, the types of failures observed, and management strategies. METHODS: We retrospectively reviewed 377 patients (420 limbs) who underwent limb lengthening with early (P1) or later (P2) MILN iterations with ≥12-month follow-up. Mechanical failure was defined as mechanical breakage of the instrumentation or nail and/or failure of the internal lengthening mechanism. Failure assessment was arranged by lengthening phases and was sorted with a complication classification system. All lengthening and alignment parameters were assessed radiographically. RESULTS: Mechanical failure was observed in 40 nails (9.5%), most of which (63%) were corrected with an additional surgical procedure. The mechanical failure rate was 11.3% in P1 nails and 9% in P2 nails. Two nails failed the intraoperative distraction test, and 1 nail was found to have a broken washer during the insertion phase. Sixteen nails had mechanical failures in the lengthening phase. Some nails (8 of 16) required nail replacement surgery. Thirteen nails failed during the consolidation phase; 7 of these cases were managed by replacement with either a functional MILN or a conventional intramedullary nail. Eight failures happened during the extraction phase and were managed intraoperatively. CONCLUSIONS: A 9.5% overall rate of mechanical failure of MILNs was observed in this large series. Resolution was achieved with an additional surgery in most cases. Nail distraction and weight-bearing compliance should be closely monitored during the lengthening and consolidation phases. Nail removal can be difficult and requires a careful study of radiographs for locking-screw bone overgrowth and backup removal equipment. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Motorized Intramedullary Nail Lengthening in the Older Population.

Limb lengthening has not been widely employed in the elderly population due to concerns that outcomes will be inferior. The purpose of this multicenter, retrospective case-control series was to report the bone healing outcomes and complications of lower limb lengthening in older patients (≥60 years) using magnetic intramedullary lengthening nail (MILN). Our hypothesis was that healing parameters including consolidation days, the consolidation index, maturation days, and the maturation index, as well as the number of adverse events reported in the older population, would be no different to those of the general adult population. We retrospectively reviewed charts and radiographs from patients ≥60 years of age with limb-length discrepancies who underwent femoral or tibial lengthening using a MILN. Parameters were compared among the age categories "≤19 years," "20-39 years," "40-59 years," or "≥60 years" and propensity-matched cohorts for the age groups 20-59 years and ≥60 years. Complications were reported as percentages for each age category. In the study period, 354 MILN were placed in 257 patients. Sixteen nails were placed in patients 60 years of age or older (mean 65 ± 5 years; range 60-72 years). Comparisons of healing parameters showed no difference between those aged 60+ and the younger cohort. Complication percentages were not statistically significant (p = 0.816). Limb lengthening with MILN may therefore be considered a safe and feasible option for a generally healthy elderly population.

Experience with negative-pressure wound therapy with instillation in complex infected orthopaedic wounds.

Chronic exudative wounds are frequently seen in hospitalised patients, consuming hospital resources and leading to increased morbidity. Negative-pressure therapy (NPWT) with topical instillation "NPWTi" may be used to improve the wound healing process, with the unique features (removal of wound exudate, edema reduction, promotion of tissue perfusion and granulation tissue formation, as well as drawing the edges of the wound to facilitate, in addition to the cyclic cleansing mechanism). This report is a descriptive study of our experience with NPWTi on complex infected orthopaedic wounds as a potential method to decrease the need for multiple surgical debridements required for the closure of such wounds. A prospective observational study was conducted. Twenty patients with complex infected orthopaedic wounds were enrolled in our study. These patients were consulted by the Bone and Joint Infection Service and enrolled to receive NPWTi intraoperatively and to be used during their inpatient stay. Twenty patients with 20 complex infected lower limb wounds were included in our study. Of all the 20 wounds, the etiology was post-surgical in 80% (n = 16) and post-traumatic in 20% (n = 4). None of the patients received previous treatment with conventional NPWT before participation in the study. There were 11 males (55%) and 9 females (45%) with an average age of 57 years (22-83). All wounds were located in the lower limbs, with 25% leg (n = 5), 20% thigh (n = 4), 20% knee (n = 4), 20% foot (n = 4), 10% heel (n = 2), and 5% ankle (n = 1). The average length of treatment with NPWTi was 5.2 days (2-10). Successful wound closure within 6 weeks was achieved in 65% of the cases (n = 13). Of the closed wounds (n = 13), 54% (n = 7) were closed primarily and 46% (n = 6) were closed by secondary procedures (skin graft or skin flap). NPWTi is still considered a novel technique that can be used in the management of complex wounds, and the goal of this prospective study is to report our experience with NPWTi in the management of complex infected orthopaedic lower limb wounds. Randomised control studies with optimally matched wounds comparing NPWTi to the conventional methods of treatment are warranted.

Ilizarov External Fixation for Correcting Complex Postpolio Foot and Ankle Deformity: A Case Study.

Given their severity and resultant loss of function, postpoliomyelitic foot and ankle deformities require a unique correction method. Correction with dynamic Ilizarov external fixation is one such modality, although it is technically demanding and requires precise preoperative planning. In our case study, a 40-year-old male with a severe postpoliomyelitic equinocavovarus right foot and ankle deformity was treated with gradual correction using dynamic, hinged Ilizarov external fixation. The external fixation was in place for a total of 103 days, with gradual correction performed in 2 successive steps, achieving a functional, plantigrade foot. We maintained this position in a short leg cast for 30 days, followed by bracing and physiotherapy for 6 months. More than 2 years after the index surgery, the patient had achieved a painless and plantigrade foot, allowing for functional ambulation. This method does not require osteotomies, ankle arthrodesis, or tendon transfer.

Treatment with posterior capsular release, botulinum toxin injection, hamstring tenotomy, and peroneal nerve decompression improves flexion contracture after total knee arthroplasty: minimum 2-year follow-up.

PURPOSE: No definite treatment option with reasonable outcome has been presented for old and refractory flexion contracture after total knee arthroplasty (TKA). We describe a surgical technique for 21 refractory cases of knee flexion contracture, including 12 patients with history of failed manipulation under anesthesia (MUA). METHODS: Retrospective review was conducted for procedures performed by a single surgeon between 2005 and 2016. Twenty-one knees (19 patients) with knee flexion contracture after primary TKA were treated with all the following procedures: posterior capsular release, hamstring tenotomy, prophylactic peroneal nerve decompression, and botulinum toxin type A injections. Twelve of the 21 knees had at least 1 prior unsuccessful MUA before this soft-tissue release procedure. Mean age at intervention was 60 years (range 46-78 years). Mean preoperative knee range of motion (ROM) was - 27° extension (range - 20° to - 40°) to 100° flexion (range 90°-115°). All radiographs were evaluated for proper component sizing and signs of loosening. RESULTS: Full extension was achieved immediately after surgery in all patients. Only one knee required repeat botulinum toxin type A injection. All patients had full extension at mean follow-up of 31 months (range 24-49 months). No significant change was observed in knee flexion after the procedure (n.s.). Significant improvement was noted in the postoperative Knee Society Score (KSS) (mean 80, range 70-90) when compared with preoperative KSS (mean 45, range 25-65) (p = 0.008). CONCLUSION: The proposed surgical technique is efficacious in treating patients with refractory knee flexion contracture following TKA to gain and maintain full extension at minimum 2-year follow-up. LEVEL OF EVIDENCE: IV, retrospective case series.

Lengthening With Monolateral External Fixation Versus Magnetically Motorized Intramedullary Nail in Congenital Femoral Deficiency.

BACKGROUND: Limb lengthening for congenital femoral deficiency (CFD) with or without fibular hemimelia can be performed with both external and internal devices. The purpose of this study is to compare clinical outcomes of femoral lengthening utilizing monolateral external fixation versus a magnetically motorized intramedullary nail in patients with CFD with or without fibular hemimelia. METHODS: This retrospective review included 62 patients with femoral lengthening, 32 patients had monolateral external fixation (group A), 30 patients had internal lengthening nail (group B). Mean age in years was 9.4±3.8 and 15.4±4.9 for groups A and B, respectively. Mean follow-up in years was 4.47±2.7 and 1.86±0.7 years for groups A and B, respectively. RESULTS: Mean lengthening achieved was 5.6±1.7 and 4.8±1.4 cm for group A and group B, respectively (P=0.052). Mean distraction index was 0.7±0.2 mm/d for group A and 0.7±0.2 mm/d for the group B (P=0.99). Mean consolidation index for group A was 29.3±12.7 and 34.8±11.2 d/cm for group B (P=0.08). Mean arc of motion before surgery and at final follow-up were similar between groups (P=0.35). Group A had significantly less range of motion at the end of distraction (P=0.0007) and at consolidation (P<0.0001). Both groups had similar rates of obstacles and complications. A significant difference between groups was found in the total problems (P<0.001) specifically with pin site/superficial infection (P<0.0001). CONCLUSIONS: The intramedullary nail had superior range of motion during the lengthening phase and at consolidation and an overall lower problem complication rate, while maintaining similar distraction and healing indices to monolateral external fixation. Internal lengthening nails represent a significant advance in technology for CFD lengthening. LEVEL OF EVIDENCE: Level IV-therapeutic.

Bone Ninja Mobile App for Reverse Planning Method in Internal Limb Deformity and Lengthening Surgery.

AIM: To report whether Bone Ninja (BN) is a reliable tool to teach the reverse planning method (RPM) for implantable intramedullary (IM) limb-lengthening devices and for deformity correction surgery. BACKGROUND: Motorised fully implantable implantable intramedullary (IM) lengthening devices have been gaining popularity all over the world for limb-lengthening procedures. Multiple advantages have been demonstrated over external fixator-controlled lengthening. Mechanical axis deviation may result if careful preoperative planning and surgical intervention are not completed for femur cases. The RPM proposed by Baumgart has been shown to be an accurate means of arriving at the desired end point. The RPM addresses the ideal correction position accounting for length, angulation, and translation created during lengthening along the nail axis. The original description calls for the use of life-size paper tracings of the bone and large light boxes to allow planning. We propose an alternative method using a digital tool that is readily available. The BN mobile app was developed for patient/physician education and is available for the Apple iPad platform. Bone Ninja has been shown to have similar accuracy for measurements of the limb length and deformity angles when compared to the gold standard picture archiving and communication systems (PACSs). TECHNIQUE: We used BN (version 4.2) on an iPad mini to perform the same RPM steps, using the same terminology originally described by Baumgart. CONCLUSION: Bone Ninja is a simple validated deformity correction tool with accuracy comparable to PACS. It is a reasonable alternative to paper/pencil cutouts for applying RPM for IM limb lengthening and deformity correction surgery. CLINICAL SIGNIFICANCE: We proposed a digitised RPM for internal limb-lengthening surgeries, which is highly feasible and practical to use conveniently without the need for the traditional tedious paper-cutting procedure and related equipment. HOW TO CITE THIS ARTICLE: Hung AL-H, McClure PK, Franzone JM, et al. Bone Ninja Mobile App for Reverse Planning Method in Internal Limb Deformity and Lengthening Surgery. Strategies Trauma Limb Reconstr 2019;14(2):72-76.

Trapezius Muscle Transfer for Restoration of Elbow Extension in a Traumatic Brachial Plexus Injury.

Voluntary elbow extension is essential for optimal upper limb positioning required for daily living activities, particularly above-shoulder maneuvers. The authors present a case of traumatic brachial plexus injury in which paralysis of the musculature selectively supplied by the posterior cord was based on magnetic resonance imaging and nerve conduction studies. An attempt at a radial nerve graft at another center was not effective. Ipsilateral hand function improved after multiple local tendon transfers were performed. Restoration of active elbow extension was not possible using the posterior deltoid or the latissimus dorsi because they were denervated by the primary trauma and so the trapezius muscle was used as a donor muscle unit to restore voluntary elbow extension. The patient resumed biking 6 weeks after the transfer procedure. At 2-year follow-up, full active elbow extension was regained, elbow extension power scored 4 of 5, and the patient reported that he could ride his bicycle for 70 miles.

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.

Trochanteric Entry for Femoral Lengthening Nails in Children: Is It Safe?

BACKGROUND: Antegrade intramedullary (IM) nailing for skeletally immature femur fractures can damage the capital femoral epiphysis blood supply, leading to avascular necrosis (AVN) of the femoral head. Reported AVN rates are 2% for piriformis entry and 1.4% for trochanteric entry. None of previous reports described IM lengthening nails for limb lengthening procedures. We have used self-lengthening telescopic nails with a proximal Herzog bend and standard trochanteric entry for femoral lengthening in children. The purpose of this study is to determine whether trochanteric entry IM lengthening nails can be used safely (no AVN or proximal femoral deformity) in the skeletally immature femur. METHODS: A retrospective review was performed between 2004 and 2014 to determine all skeletally immature patients younger than 18 years of age who had a reamed IM lengthening nail inserted through the greater trochanter, with at least 1-year follow-up. RESULTS: Thirty-one femurs were lengthened in 28 patients (17 males and 11 females). The etiology was congenital femoral deficiency (10), achondroplasia (6), post-traumatic (5), hemihypertrophy (3), Ollier disease (2), and miscellaneous (5). An attending surgeon was present for all procedures. Mean age at time of surgery was 12.9 years (range, 7 to 17 y). Mean follow-up was 3.5 years (range, 1.4 to 9 y). The average amount of lengthening was 5.4 cm (range, 3 to 6.7 cm). Twenty-four nails were 10.7 mm in diameter. Seven nails were 12.5 mm in diameter. Intramedullary skeletal kinetic distractor was used in 18 femurs and PRECICE in 13 femurs. Ten segments (7 intramedullary skeletal kinetic distractor; 3 PRECICE) experienced 13 complications. None of the patients developed AVN or proximal femoral deformity. CONCLUSIONS: IM lengthening nails inserted through the greater trochanter may be utilized in skeletally immature patients without increased risk of AVN of the femoral head or proximal femoral deformity. Larger trials would be helpful to confirm our hypothesis. We recommend careful surgical technique with liberal use of the image intensifier to avoid trauma to the femoral head blood supply. LEVEL OF EVIDENCE: Level IV-therapeutic.

Treatment of Post-Traumatic Femoral Discrepancy With PRECICE Magnetic-Powered Intramedullary Lengthening Nails.

OBJECTIVE: To evaluate the outcomes of lengthening post-traumatic femoral segments using a recently available magnetic intramedullary (IM) lengthening system. DESIGN: Retrospective cohort study. SETTING: Urban level II Trauma Center. PATIENTS/PARTICIPANTS: Patients treated for post-traumatic femoral shortening at our institution between 2012 and 2015. We identified 17 femurs lengthened (14 men and 3 women). The mean age was 30 years (range, 11-72 years). INTERVENTION: Magnetic IM lengthening system. MAIN OUTCOME MEASUREMENTS: Amount of lengthening achieved, consolidation index, and complications encountered. RESULTS: The mean follow-up was 2.2 years (range, 1-3.7 years). Sixteen patients achieved the planned lengthening, a mean of 3.8 cm (range, 2.3-6.0 cm). Regenerate consolidation occurred at a mean of 119 days (range, 57-209 days). The mean consolidation index was 32 d/cm (range, 16-51 d/cm). Three patients (18%) experienced complications. CONCLUSION: IM lengthening nails are an improvement over external fixators for treatment of post-traumatic femoral shortening. Within certain limits, their use can be extended to problems of limb-length discrepancy with angular/rotational deformity. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Solid screw insertion for tension band plates: a surgical technique tip.

PURPOSE: Growth modulation with tension band plates (TBPs) and cannulated screws is the current mainstay of treatment for pediatric lower extremity angular deformities. Solid screws have been used as an alternative to cannulated screws to decrease the risk of screw failure, particularly in obese children. The downside of solid screws is the decrease in precision of placement. This study describes a surgical technique to insert solid TBP screws accurately. METHODS: TBP insertion starts with the same conventional steps by inserting the guidewires into the epiphysis and metaphysis, straddling the physis. After fluoroscopic confirmation of the position of the guidewires, the cannulated drill bit is used to broach the cortex to a depth of 5 mm in the bone. A standard 4.5-mm cannulated screw from the TBP set is used to tap the screw tract over the guidewires for approximately three-quarters of the planned screw length. After removing the guidewires, the solid screws are then inserted in each hole to follow the tapped tracts. RESULTS: This technique was used in five patients including four with Blount disease and one with bilateral genu varum. CONCLUSION: It is recommended to use solid screws with TBPs in patients with a high body mass index to avoid screw fracture. Our technique describes using a cannulated screw as a tap to create a tract to ease accurate insertion of the solid screws, and prevent the solid screw from deviating outside the desired path.

Mechanical rigidity of the Ortho-SUV frame compared to the Ilizarov frame in the correction of femoral deformity.

The Ortho-SUV frame (OSF) is a novel hexapod circular external fixator which draws upon the innovation of the Ilizarov method and the advantages of hexapod construction in the three-dimensional control of bone segments. Stability of fixation is critical to the success or failure of an external circular fixator for fracture or osteotomy healing. In vitro biomechanical modelling study was performed comparing the stability of the OSF under load in both original form and after dynamisation to the Ilizarov fixator in all zones of the femur utilising optimal frame configuration. A superior performance of the OSF in terms of resistance to deforming forces in both original and dynamised forms over that of the original Ilizarov fixator was found. The OSF shows higher rigidity than the Ilizarov in the control of forces acting upon the femur. This suggests better stabilisation of femoral fractures and osteotomies and thus improved healing with a reduced incidence of instability-related bone segment deformity, non-union and delayed union.

Determination of the Maximal Corrective Ability and Optimal Placement of the Ortho-SUV Frame for Femoral Deformity with respect to the Soft Tissue Envelope, a Biomechanical Modelling Study.

Circular fixation according to the Ilizarov method is a well-recognised modality of treatment for trauma and deformity. One shortcoming of the traditional fixator is its limited ability to correct more than one plane of deformity simultaneously, leading to lengthy frame-time indices. Hexapod circular fixation utilising computer guidance is commonplace for complex multidimensional deformity but difficulties often arise with correction of femoral deformity due to bulkiness of the frame construct, particularly in proximal deformity and in patients of increased size. The Ortho-SUV frame is an innovative hexapod which permits unique customisation to individual patient anatomy to maximise tolerance and optimal range of deformity correction. We hypothesised that the optimal configuration and maximal degree of correction achievable by the Ortho-SUV frame can be biomechanically modelled and applied clinically. A study was constructed using Ortho-SUV and femoral limb models to measure deformity correction via differing frame constructs and determine optimal frame configuration to achieve correction in proximal, middle, and distal third deformities with respect to the soft tissue envelope. The ideal frame configuration is determined for correction of deformity in all locations of the femur with the maximal parameters of correction calculated whilst avoiding and mitigating soft tissue irritation from bulky frame construction.