Verlängerung der unteren Extremität mit dem Intramedullary Skeletal Kinetic Distractor (ISKD)

OBJECTIVE: Callus distraction of the femur or tibia with an intramedullary distractor, which lengthens mechanically through alternating rotations of at least 3 degrees. INDICATIONS: Femoral or tibial shortening between 20 and 80 mm. Angular and rotational deformities can be corrected at the osteotomy site. CONTRAINDICATIONS: Open epiphyses. Small medullary canal (after intramedullary reaming femoral diameter < 14.5 mm, tibial diameter < 12.5 mm). Severe deformities. Insufficient compliance. Osteitis. Soft-tissue infections. SURGICAL TECHNIQUE: Supine position. Femoral shaft osteotomy at the proximal or middle third by multiple drill holes completed with a chisel. For lengthening of the tibia, osteotomy with a Gigli saw is preferred. Control of the rotation by two parallel 3.0-mm Kirschner wires. Correction of angular or rotational deformities. Via stab incision reaming of the medullary canal with a flexible reamer. The femur is overreamed 2.0 mm and the tibia 1.5 mm above the desired implant diameter. Insertion of the Intramedullary Skeletal Kinetic Distractor (ISKD) into the medullary canal and distal locking in freehand technique. Control of the rotation and of the osteotomy gap. Proximal locking with an aiming device. For femoral lengthening 3 days and for tibial lengthening 5 days postoperatively the distraction is begun by increasing mobilization with partial weight bearing, to achieve daily distraction of 1 mm. In case of insufficient distraction, additional rotations are performed by the patient while checking the external monitor that displays the daily and total distraction length. RESULTS: Intramedullary lengthening with the ISKD was performed in four patients having an average age of 29 years (18-36 years). Two femoral shortenings were combined with complex rotational and angular deformities. The average lengthening of three femora and one tibia was 31 mm (26-40 mm). The average intraoperative blood loss was 230 ml (110-320 ml), the mean surgical time 108 min (90-145 min). The average daily distraction amounted to 1.2 mm (0.9-1.8 mm). Full weight bearing was permitted after 10 weeks (7-14 weeks), return to regular work after 11 weeks (7-16 weeks). At follow-up examination of an average of 2.3 years postoperatively the knee range of motion was full. Consolidation was noted 80 days (51-111 days) postoperatively with an average consolidation index of 2.9 days/mm (1.8-4.1 days/mm). No complications were observed. According to the Paley Score all patients had an excellent outcome.     

Längenkorrekturen der unteren Extremität mit voll implantierbaren Distraktionsmarknägeln

All commercially available fully implantable intramedullary distraction nails, Albizzia®, Fitbone® II and ISKD, were used for lengthening of the femur and tibia. Albizzia® has the best cost-performance ratio: the lengthening capacity is 100 mm; the stability tolerates early weight bearing and unlimited physiotherapy immediately after the operation; it has a reliable feed with safe function and so requires only a few clinical and radiological controls. The first activation of the lengthening system needs careful guidance by the surgeon. Fitbone® II appears easy to handle without active cooperation of the patient, and at present it is the only nail for simultaneous lengthening of four regions. It is expensive with limited stability and control and requires frequent clinical, sonographic and radiological controls. It allows the shortest maximal lengthening. ISKD is priced between Albizzia® und Fitbone® II, does not allow early weight bearing, is difficult to control and cannot be used for simultaneous lengthening. Internal systems for callus distraction are superior to the external devices in many respects: shorter hospitalization and rehabilitation times, low infection risk, more extensive physiotherapy, better aesthetic outcome and minimal consequential costs.     

Femur lengthening with a telescopic intramedullary nail ISKD--method presentation and early clinical results

INTRODUCTION: Limb discrepancy over 4 cm is an indication for limb lengthening. Surgical techniques rely on osteotomy, external stabilisation and gradual distraction. The ISKD (Intramedullary Skeletal Kinetic Distractor) nail allows distraction osteogenesis and no external fixator is required. AIM OF PAPER: Aims of paper are: presentation of limb elongation method with the ISKD device, and presentation of early own results. MATERIAL AND METHODS: Material consists of 5 patients, age 14-16 years, 3 boys and 2 girls, who underwent femur lengthening with the ISKD nail between 2005 and 2007. We evaluated: initial shortening, surgical procedure, complications, amount of lengthening, lengthening rate, distraction index, time of treatment and mobility of adjacent joints. RESULTS: Initial shortening was 4-11 cm. No surgical complications were observed, mean time of surgery was 145 minutes, mean blood loss--200 ml. In three patients difficulties with initial distraction required manipulations under general anaesthesia. Distraction was complicated in 3 cases--in two patients premature consolidation was noted; in one case the distraction rate was too high. Mean lengthening rate in the study group was 0.7 mm/day (0.6-0.7 mm/day). Mean distraction index was 41.7 days/cm (26.2-55 days/cm). Full weight bearing was allowed after mean 234 days (210-275 days). Transient decrease of adjacent joint mobility was observed. CONCLUSION: The fully implantable, telescopic ISKD eliminates the need of external fixation and associated complications. Early results of limb lengthening with ISKD are encouraging. Careful patient selection and preoperative planning is required. Further studies and longer follow-up periods are needed.     

Promises and difficulties with the use of femoral intra-medullary lengthening nails to treat limb length discrepancies

Limb lengthening using external fixation may be associated with problems such as pin-track infections, poor patient acceptance, muscle transfixation, secondary axial deformity and re-fractures. Intramedullary lengthening nails have been designed to address these issues. We present our results for femoral limb lengthening in adults managed by intramedullary lengthening nails. A retrospective review was undertaken for 8 femoral lengthening procedures performed in adults using intra-medullary lengthening nails over a three-year period. The average age of our patients was 34 years; the average duration of follow-up was 26.5 months (range: 8 to 40 months). An Albizzia nail was used in 5 procedures, an Intra-medullary Skeletal Kinetic Distractor (ISKD nail) in 3 procedures. Target lengthening was achieved in 6 out of 8 femurs with an average of 38.77 mm (range: 0 to 70 mm) length gained. The distraction index (length gained per day) was 0.58 on average (range: 0-1.25) and the consolidation index average was 5039 (range: 0-79) days/cm. Premature consolidation was noted in 4 cases, runaway acute lengthening in one patient; prominent metalwork--noted in 4 patients--and a bent nail were frequent obstacles and meant multiple visits to theatre. Femoral lengthening with an intramedullary lengthening nail is a reasonable alternative to external fixators, thereby avoiding problems associated with callotasis using external fixation methods. It is however, important to counsel patients regarding possibilities of significant obstacles including failure and multiple visits to theatre during the process.     

Lower extremity lengthening by Wagner's method and by callus distraction

Fifty-three patients underwent 64 lengthenings of the femur or tibia by the Wagner technique or by the callus distraction method. Thirty-six femoral and 28 tibial segments were lengthened. Simultaneous lengthening of the femur and tibia was performed in seven limbs. Three segments underwent repeat lengthenings. The average length gained by the Wagner method was 5.1 cm in the femur and 5.4 cm in the tibia. Length gains by callus distraction were 4.9 cm in the femur and 4.5 cm in the tibia. Complication rates were fewer and less severe with callus distraction. The number of operations, days of hospitalization, and length of total treatment were less in patients operated on with the callus distraction method than in those who underwent the Wagner technique.     

A novel intramedullary callus distraction system for the treatment of femoral bone defects

An intramedullary device has some advantages over external fixation in callus distraction for bone defect reconstruction. There are difficulties controlling motorized intramedullary devices and monitoring the distraction rate which may lead to poor results. The aim of this study was to design a fully implantable and non-motorized simple distraction nail for the treatment of bone defects. The fully implantable device comprises a tube-in-tube system and a wire pulling mechanism for callus distraction. For the treatment of femoral bone defects, a traction wire, attached to the device at one end, is fixed to the tibial tubercle at its other end. Flexion of the knee joint over a predetermined angle generates a traction force on the wire triggering bone segment transport. This callus distraction system was implanted into the femur of four human cadavers (total 8 femora), and bone segment transport was conducted over 60-mm defects with radiographic monitoring. All bone segments were transported reliably to the docking site. From these preliminary results, we conclude that this callus distraction system offers an alternative to the current intramedullary systems for the treatment of bone defects.     

Callus distraction lengthening of the tibia with the intramedullary kinetic nail (case report)

In this report the first experience with callus distraction lengthening using the intramedullary kinetic nail is described. This was performed on a left tibia with a total shortening of 34 mm. The distraction phase lasted 36 days and the rate of distraction was 0.95 mm per day. The full weight-bearing of the treated lower extremity was allowed at 12 weeks after surgery. Complete consolidation of the callus was achieved at 112 days and the consolidation index was 3.21 days/mm. No serious complications were recorded during the post-operative period. At 12 months after surgery, the patient showed a full range of motion in the knee, his ankle range of motion was S 15-0-35, and he achieved an excellent functional outcome on evaluation by Paley's classification.     

Problems encountered in leg shortening

We reviewed 46 leg-shortening operations (37 femoral and nine tibial), performed by different methods, to assess the incidence of complications and permanent disability. Shortening of as much as 7.5 cm in the femur and 5 cm in the tibia was achieved in men of normal height without any loss of function. Complications were seen with all surgical techniques despite the use of modern implants. Most problems arose from inadequate stabilisation of the osteotomy. The most reliable method of femoral shortening was open subtrochanteric osteotomy with preservation of the isthmus, and fixation with an intramedullary nail locked at its proximal end. In tibial shortening, bone excision should be at the level of the flare in the lower diaphysis in order to achieve reliable bone healing. Simple intramedullary nail fixation should be supplemented with a long-leg cast for six weeks or the nail should be locked at both ends to prevent postoperative distraction or rotation.     

Callus patterns in femoral lengthening over an intramedullary nail

Our objectives were to evaluate callus patterns seen in femoral lengthening over an intramedullary nail by Li classification regarding shape and type and to predict the result while using the nail to reduce the external fixation period and its complications. Eight hundred digital radiographs of 15 patients with 15 segments of femur shortening who underwent femoral lengthening with a monolateral external fixator over an intramedullary nail were analyzed retrospectively by four observers. Each radiograph was studied for callus shape, feature type, and callus density using pixel values. The classification was tested for concurrence and reproducibility by interobserver studies and callus patterns were compared with treatment indices to evaluate how they correlated with the outcome. Mean length gained was 4.5 cm (range: 2–8 cm). External fixator index (EFI) was 21.68 days/cm. Average distraction consolidation index (DCI) was 48.49 days/cm. Fusiform callus was seen in three cases, cylindrical in seven, and lateral in five. The homogenous pathway had higher DCI (43.7) than the heterogeneous pathway (32.9), and mixed pathways making up the rest had a DCI of 50.1. Pixel value of callus showed gradual increase in density until 20–24 weeks, then density gradually fell for 8 weeks, again increased after 32 weeks, again gradually fell, and was comparable to adjacent normal bone by 44–48 weeks. Our results suggest that the Li classification can be satisfactorily applied to lengthening procedures over intramedullary nails. The radiologic pattern and pixel value of regenerate can be correlated with the clinical outcome and can be an aid of prognostic value for the surgeon. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1106–1113, 2011     

Lower limb lengthening by a modified Wagner technique

A series of 50 patients who underwent femoral and tibial lengthenings using the Wagner apparatus is reviewed. Satisfactory gains in leg length with an acceptably low complication rate were achieved. Both substitution of cortical osteotomy for complete osteotomy and delaying of distraction increased callus formation. The particular problems of lengthening the congenital short femur and tibia are discussed.     

Improved comfort in lower limb lengthening with the intramedullary skeletal kinetic distractor

Introduction Limb lengthening by external fixators is associated with many problems such as pain at the pin tracts, muscle transfixation, pin tract infections, reduced joint motion, and prolonged fixation time. The intramedullary skeletal kinetic distractor (ISKD) is a new internal, mechanically activated implant, which distracts by mild rotations of 3°.Material and methods In a prospective clinical study, four patients with an mean age of 29 years (18–36 years) underwent intramedullary lengthening via ISKD. The average lengthening of three femora and one tibia was 31 mm (26–40 mm).Results All patients performed the rotations for the distraction themselves without any significant problems. One patient took mild analgesics during the first days of distraction, whereas three patients did not require any analgesics. The average patient discharge occurred 10 days (8–11 days) postoperatively with no complications during the hospital stay. The planned length of distraction was achieved in all patients with normal alignment and normal joint orientation. Full weight bearing was performed on average after 10 weeks (7–14 weeks). Consolidation was noted 80 days (51–111 days) postoperatively with an average consolidation index of 2.9 days/mm. No complications were observed during the follow-up period of 14 months. The Enneking score was 26.8 points, and according to the classification of Paley all patients had an excellent result.Conclusions From these preliminary results we conclude that the comfort of limb lengthening with the ISKD is increased by the elimination of fixator-associated complications and by the simple distraction mechanism, which is well tolerated by the patients. Further advantages of the ISKD are early full weight bearing and excellent limb function.     

Tibial lengthening and concomitant foot deformity correction in 14 patients with permanent deformity after poliomyelitis

BACKGROUND: In neuromuscular diseases, limb lengthening and foot deformity correction are associated with a high risk of complications associated with distraction callus and joint contracture. We have found no published articles of tibial lengthening and concomitant foot deformity correction using the Ilizarov method or traditional methods. To compare result of gradual distraction with triple arthrodesis for foot deformity combined with tibial lengthening, we investigated healing index and complications of two methods. PATIENTS AND METHODS: We reviewed 14 patients with permanent deformity after poliomyelitis who underwent tibial lengthening and concomitant foot deformity correction using the Ilizarov external fixator. Tibial lengthening over an intramedullary nail was performed in 3 patients and lengthening without a nail was performed in 11 patients. RESULTS: The mean external fixation time was 6 (3.6-10) months without nail and 1.6 (1.5-1.7) months with nail, whereas the mean healing index was 1.8 (0.8-3.1) months/cm without nail and 2 (1.8-2.3) months/cm with nail. Concomitant foot treatments included triple arthrodesis in 7 patients, pantalar arthrodesis in 2 patients with flail ankle, and gradual foot frame distraction without bony foot procedures in 5 patients. Delayed consolidation and recurrent equinus contracture of the ankle requiring additional lengthening of the Achilles tendon were the most common bone and joint complications during tibial lengthening. INTERPRETATION: The gradual foot frame distraction method was associated with major complications, such as recurrent foot deformity, joint luxation, and arthritis. We therefore recommend triple arthrodesis as a concomitant procedure during tibial lengthening     

Reconstruction of segmental bone defects due to chronic osteomyelitis with use of an external fixator and an intramedullary nail

BACKGROUND: Callus distraction over an intramedullary nail is a rarely used technique for the reconstruction of intercalary defects of the femur and tibia after radical débridement of chronic osteomyelitic foci. The aim of this study was to summarize our experience with distraction osteogenesis performed with an external fixator combined with an intramedullary nail for the treatment of bone defects and limb-shortening resulting from radical débridement of chronic osteomyelitis. METHODS: Thirteen patients who ranged in age from eighteen to sixty-three years underwent radical débridement to treat a nonunion associated with chronic osteomyelitis of the tibia (seven patients) and femur (six patients). The lesions were classified, according to the Cierny-Mader classification system, as type IVA (nine) and type IVB (four). The resulting segmental defects and any limb-length discrepancy were then reconstructed with use of distraction osteogenesis over an intramedullary nail. Two patients required a local gastrocnemius flap. Free nonvascularized fibular grafts were added to the distraction site for augmentation of a femoral defect at the time of external fixator removal and locking of the nail in two patients. At the time of the latest follow-up, functional and radiographic results were evaluated with use of the criteria of Paley et al. RESULTS: The mean size of the defect was 10 cm (range, 6 to 13 cm) in the femur and 7 cm (range, 5 to 10 cm) in the tibia. The mean external fixator index was 13.5 days per centimeter, the consolidation index was 31.7 days/cm, and the mean time to union at the docking site was nine months (range, five to sixteen months). At a mean follow-up of 47.3 months, eleven of the thirteen patients had an excellent result in terms of both bone and functional assessment. There were two recurrences of infection necessitating nail removal. These patients underwent revision with an Ilizarov fixator. Subsequently, the infection was controlled and the nonunions healed. CONCLUSIONS: This combined method may prove to be an improvement on the classic techniques for the treatment of a nonunion of a long bone associated with chronic osteomyelitis, in terms of external fixation period and consolidation index. The earlier removal of the external fixator is associated with increased patient comfort, a decreased complication rate, and a convenient and rapid rehabilitation.     

Treatment of fractures of femur and tibia with the telescopic locking nail: design of a new implant and the first clinical results.

BACKGROUND: This study was carried out to evaluate the first clinical experiences with the telescopic locking nail (TLN). The TLN is a newly developed universal locking nail system for both femur and tibia that permits cyclic dynamic loading at the fracture site while weightbearing. The nail can also be used for static interlocking or for compression of the fracture elements. The nail is strong enough to permit immediate weightbearing, and the diameter of 9 mm allows unreamed introduction in many cases. MATERIALS: Seventy-one consecutive patients were treated with the TLN, 24 patients with femoral and 47 patients with tibial fracture or nonunion. RESULTS: Functional outcome, complication rate, and union rate were comparable to other interlocking nail systems. CONCLUSION: Its distinctive biomechanical properties and its universal application in both femur and tibia make the TLN a sophisticated, yet in practice simple, new asset in the practice of intramedullary nailing.     

Tibial lengthening and concomitant foot deformity correction in 14 patients with permanent deformity after poliomyelitis

Background In neuromuscular diseases, limb lengthening and foot deformity correction are associated with a high risk of complications associated with distraction callus and joint contracture. We have found no published articles of tibial lengthening and concomitant foot deformity correction using the Ilizarov method or traditional methods. To compare result of gradual distraction with triple arthrodesis for foot deformity combined with tibial lengthening, we investigated healing index and complications of two methods.

Patients and methods We reviewed 14 patients with permanent deformity after poliomyelitis who underwent tibial lengthening and concomitant foot deformity correction using the Ilizarov external fixator. Tibial lengthening over an intramedullary nail was performed in 3 patients and lengthening without a nail was performed in 11 patients.

Results The mean external fixation time was 6 (3.6- 10) months without nail and 1.6 (1.5-1.7) months with nail, whereas the mean healing index was 1.8 (0.8-3.1) months/cm without nail and 2 (1.8-2.3) months/cm with nail. Concomitant foot treatments included triple arthrodesis in 7 patients, pantalar arthrodesis in 2 patients with fiail ankle, and gradual foot frame distraction without bony foot procedures in 5 patients. Delayed consolidation and recurrent equinus contracture of the ankle requiring additional lengthening of the Achilles tendon were the most common bone and joint complications during tibial lengthening.

Interpretation The gradual foot frame distraction method was associated with major complications, such as recurrent foot deformity, joint luxation, and arthritis. We therefore recommend triple arthrodesis as a concomitant procedure during tibial lengthening     

Leg lengthening using intramedullay skeletal kinetic distractor: Results of 57 consecutive applications

Background

Mechanically activated intramedullary lengthening nails are advantageous over external fixator. However, difficulties with the control of the distraction rate are the main drawbacks, which may in turn cause insufficient bone regenerate.

Patients and methods

A total of 57 lengthening procedures were performed using intramedullary skeletal kinetic distractor (ISKD) nail in 53 patients (femoral = 45 and tibial = 12). Average length gain was 4.3 ± 1.6 cm. The cause of shortening was post-traumatic (n = 33), congenital (n = 20), post-tumour resection (n = 1), cosmetic femoral lengthening (n = 2) and post-correction of distal femoral varus deformity (n = 1).

Results

The desired lengthening was achieved in all patients. The mean follow-up period was 23 ± 12 months. The healing index for patients with normal bone healing was 1.2 ± 0.32 months/cm. Complications in femoral lengthening were superficial wound infection (n = 1), premature consolidation (n = 4) and insufficient bone regenerate (n = 11), while in the tibial lengthening, two developed equinus contractures, one had compartment syndrome following implantation of the nail and one insufficient bone regenerate. Furthermore, nine runaway nails and three non-distracting nails were present in the femoral lengthening. One non-distracting nail responded to manipulation under anaesthesia, one required exchange nailing and accidental acute lengthening of 3 cm took place while manipulating the third nail. Patients with femoral lengthening and those with insufficient regenerate had significantly higher distraction rates (P = 0.006 and 0.003, respectively). Six out of the nine runaway nails developed insufficient bone regenerate. In addition, 10.7-mm tibial ISKD nails were found to have lower rates of runaway nails compared with other used diameters.

Conclusion

We emphasise the rule of distraction rates above 1.5 mm/day in the development of insufficient bone regenerate. Distraction problems with these nails are mostly due to dysfunction within the ratcheting mechanism, which may be related to the diameter of the nail. New designs for mechanically activated nails with a better control mechanism for the distraction rate are required.     

Limb lengthening and deformity correction with externally controlled motorized intramedullary nails: evaluation of 50 consecutive lengthenings

Background and purpose — Limb lengthening with an intramedullary motorized nail is a relatively new method. We investigated if lengthening nails are reliable constructs for limb lengthening and deformity correction in the femur and the tibia.

Patients and methods — 50 lengthenings (34 Precice and 16 Fitbone devices) in 47 patients (mean age 23 years [11–61]) with ≥12 months follow-up are included in this study. 30 lengthenings were done due to congenital and 20 because of posttraumatic deformity (21 antegrade femora, 23 retrograde femora, 6 tibiae). Initial deformities included a mean shortening of 42?mm (25–90). In 15 patients, simultaneous axial correction was done using the retrograde nailing technique.

Results — The planned amount of lengthening was achieved in all but 2 patients. 5 patients who underwent simultaneous axial correction showed minor residual deformity; unintentionally induced minor deformities were found in the frontal and sagittal plane. The consolidation index was 1.2 months/cm (0.6–2.5) in the femur and 2.5 months/cm (1.6–4.0) in the tibia. 2 femoral fractures occurred in retrograde femoral lengthenings after consolidation due to substantial trauma. There were 8 complications, all of which were correctable by surgery, with no permanent sequelae.

Interpretation — Controlled acute axial correction of angular deformities and limb lengthening can be achieved by a motorized intramedullary nail. A thorough preoperative planning and intraoperative control of alignment are required to avoid residual and unintentionally induced deformity. In the femur relatively fast consolidation could be observed, whereas healing was slower in the tibia.     

Femoral lengthening with a motorized intramedullary nail

Purpose — We assessed whether an intramedullary lengthening device would reduce the problems normally associated with the external fixation technique. We also wanted to determine whether it is a reliable construct for limb lengthening and deformity correction in the femur.

Patients and methods — We conducted a matched-pair comparison of 30 femoral lengthenings, 15 with a motorized intramedullary nail (the nail group) and 15 lengthenings with an external ring fixator (the fixator group). The patients were matched based on age, sex, amount of lengthening, and the etiology of leg length discrepancy. Mean lengthening was 35 (25–55) mm in the nail group and 38 (15–75) mm in the fixator group. Outcome measures were: lengthening and alignment achieved, consolidation index, knee range of motion (ROM), and complications.

Results — The pairs in this matched-pair study were similar in terms of age, sex, diagnosis, and amount of lengthening. The planned amount of lengthening was achieved in all patients in both groups and axis correction was considered sufficient. The mean radiographic consolidation index in the nail group, at 1.5 (0.9–3.0) months/cm, was better than the mean value for the fixator group (1.9 (0.9–3.4) months/cm) (p = 0.01). Knee ROM was better in the nail group during the lengthening, 6 weeks after lengthening was completed, and 6 months after lengthening was completed (p < 0.001). A larger number of complications were observed in the fixator group than in the nail group.

Interpretation — A lengthening nail may be superior to external fixation in femoral lengthening, when the anatomical conditions and the complexity of the deformity allow the use of an intramedullary nail.     

Tibial lengthening using a reamed type intramedullary nail and an Ilizarov external fixator

The aim of this study was to evaluate the efficacy of tibial lengthening using a reamed type intramedullary nail and an Ilizarov external fixator for the treatment of leg length discrepancy or short stature. This retrospective study was performed on 18 tibiae (13 patients) in which attempts were made to reduce complications. We used an Ilizarov external fixator and a nail (10 mm diameter in 17 tibiae and 11 mm in one tibia) in combination. Average limb lengthening was 4.19 cm (range, 2.5-5.5). The mean duration of external fixation was 12.58 days per centimetre gain in length, and the mean consolidation index was 40.53 (range, 35.45-51.85). All distracted segments healed spontaneously without refracture or malalignment. Gradual limb lengthening using a reamed type intramedullary nail and circular external fixation in combination was found to be reliable and effective and reduced external fixation time with fewer complications.