Callus formation in the humerus compared with the femur and tibia during limb lengthening

We investigated whether the callus formation in the humerus during the distraction period of limb lengthening proceeds at a higher rate than that in the femur and tibia. Ten achondroplastic patients underwent 3 bilateral humerus, 3 bilateral femur and 4 bilateral tibia lengthenings. To reduce the confounding effect of bone size, we used bone mineral apparent density (BMAD) to compare the three groups; this is a volumetric bone mineral density measurement. BMAD in the distracted callus space was evaluated at 8 weeks after the start of distraction using dual-energy X-ray absorptiometry (mean ± SD; g/cm³): in the humerus (0.24 ± 0.08) it was significantly higher than in the tibia (0.10 ± 0.02), while there was no difference between the humerus and femur (0.35 ± 0.11). We conclude that the callus formation in the humerus during the distraction period of limb lengthening proceeded at a significantly faster rate than in the tibia, but there was no significant difference between the humerus and femur. Received: 4 March 1997     

Treatment of post-traumatic limb shortening]

The physiological phenomenon of changes in callus formation during distraction was first described by Codivilla at the beginning of this century. Having investigated and proved the influence of tension stress on callus formation, Ilizarov used this as a method to treat limb shortening and deformities. Because of his remarkable results we introduced this method in our hospital in 1990, using the original Ilizarov ring fixator. From November 1990 to December 1991, we used this technique in 10 cases of combined post-traumatic bone shortening with deformity (the tibia was affected in six patients, the femur in three and the forearm in one). The mean shortening was 3.1 cm, the mean varus or valgus deformity 9.5 degrees, the mean anteflexion or recurvation 8.3 degrees, and the mean rotation deformity 8.5 degrees. Distraction/correction lasted between 8 and 55 days (mean: 37 days). Fixation was necessary for between 60 and 339 days. If corticotomy was performed in the diaphyseal bone, fixation lasted almost twice as long (11.33 days/mm lengthening) as in the metaphyseal area (6.55 days/mm lengthening). There were 14 complications, most of which were considered minor. The latter included pin infections (4), wire breaking (1) and restricted range of motion of the knee or ankle (5). Among the major complications were two nerve irritations, which recovered spontaneously, and two pin-induced local bone infections, which required surgical intervention. Achievement of the goals of treatment-complete correction of shortening and deformity-was not affected by these complications.     

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.     

Intermittent parathyroid hormone (1-34) enhances mechanical strength and density of new bone after distraction osteogenesis in rats.

Distraction osteogenesis is used both for leg lengthening and for bone transportation in the treatment of fractures and nonunions. The main problem with this method is that the time until full recovery may be up to a year, partly because of the time needed for the new formed bone to consolidate and become strong enough for weight bearing. We have studied whether intermittent parathyroid hormone (PTH(1-34)) could accelerate the consolidation of new formed bone after distraction osteogenesis in rats. Forty-seven, 3-months-old male Sprague-Dawley rats underwent lengthening of the right femur using an external fixator. After a middiaphyseal osteotomy and a 7-day latency period, the callus was distracted during 10 days, with a distraction rate of 0.25 mm twice a day. The consolidation time was either 20 days or 40 days after distraction was completed. A dose of 60 microg of human PTH(1-34)/kg body weight/injection or vehicle was given every second day beginning 30 days before the rats were killed. Both femura of each rat were subjected to mechanical testing and dual-energy X-ray absorptiometry. Blinded histological examination was done for the distracted femura. In the 20 days consolidation experiment, PTH(1-34) increased ultimate load (56%), stiffness (117%), total regenerate callus volume (58%), callus BMC (24%) and histologic bone density (35%) compared to untreated distraction osteogenesis specimens. In the 40 days consolidation experiment, PTH(1-34) increased ultimate load (54%), stiffness (55%), callus BMC (33%) and histologic bone density (23%) compared to untreated distraction osteogenesis specimens. Total regenerate callus volume was unchanged. The contralateral femur also became stronger, stiffer and denser under PTH(1-34) treatment, but to a lesser degree. PTH(1-34) might become useful to shorten the consolidation time after distraction osteogenesis in humans.     

Lengthening of the amputation stumps of the distal phalanges using the modified Ilizarov method

PURPOSE: The purpose of this study was to introduce the technique for distraction lengthening of the traumatic amputation stumps of distal phalanges less than 10 mm long by using the Ilizarov minifixator (Ito Medical Instruments, Tokyo, Japan) and to report the treatment results and the problems we encountered. METHOD: Six patients (3 men and 3 women) underwent lengthening of the traumatic amputation stumps of distal phalanges using the Ilizarov minifixator. The mean pre-operative length of the distal phalanges was 6.0 mm and the mean deficiency in length was 9.5 mm compared with the contralateral finger or thumb. RESULTS: In 5 of the 6 patients callus lengthening was completed without early consolidation or bone failure related to the traction wires. The mean gain in lengthening of the distal phalanx was 6.8 mm and the mean final length of the distal phalanx was 12.8 mm. After surgery 4 patients had onychoplasty and advancement flap coverage of the distal phalangeal tip because of excessive skin tension and 1 patient had arthrodesis because of flexion contracture of the distal interphalangeal joint. The patients were satisfied with the cosmetic improvement of their fingertips. CONCLUSIONS: Although this callus distraction method required multiple surgical procedures it is considered worthy of more frequent application especially in young patients.     

Delayed distraction in bone lengthening. Improved healing in lambs.

We compared delayed distraction (DD) with immediate distraction (ID) in bone-lengthening. Open femoral diaphyseal osteotomy was performed on 24 three-month-old lambs, and external distractor fixators were applied. In the ID group (n 12), distraction commenced on the first postoperative day; in the DD group (n 12), distraction was delayed until the tenth day after surgery. In all the animals, the femur was lengthened by 2 cm at the rate of 1 mm/day. The animals were killed 1, 2, and 3 months postoperatively. Radiography and densitometry of the lengthened callus showed that DD, compared with ID, improved the quality of the callus with quicker, denser, and more homogeneous bone formation.     

Kallusdistraktion

The treatment of large bone defects to maintain the length of an extremity is often complicated. The Ilizarov method of callus distraction, which combines acute shortening with subsequent lengthening using an external ring fixator, offers a new approach to the treatment of bone defects.The principles of distraction and various systems of implementation are explained.They offer options for limb lengthening, bone defect bridging and also axial line correction.Complications described in the literature are failure of regeneration, pin infection, axis deviation and malunion.The results of our retrospective analysis of 157 patients with tibial segment loss and distraction in the case of osteomyelitis or defect fractures are presented.The most interesting detail to emerge was the significantly higher incidence of complications in smokers.We conclude that the Ilizarov techniques are effective in treating sequelae bone losses and axis deviations.For good results the preoperative planning is most important.Finally, this technique is complex and not easy to learn, but with appropriate training and experience it is a useful and successful method.     

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     

Treatment of traumatic bone defects by bone transport.

This study retrospectively evaluates the results of the management using the callus distraction method, of 19 patients who had developed bone defects following acute trauma. Sixteen patients were males, with a mean age of 19.4 years (6-41 years). Thirteen patients developed bone defects as a result of high-velocity gunshot injuries, and six had defects caused by traffic accidents. The location of 12 fractures was the tibia, and seven were in the femur. The mean follow-up period was 23.6 (12-40) months. The mean length of the bone defect was 6.8 cm (4-16 cm), the distraction index was 13.3 days/cm (7.5-18 days/cm) and the external fixation index was 36.6 days/cm (32.5-46 days/cm). Fifteen (9%) pintract infections were observed among those who underwent circular external fixation and four (10%) in cases who underwent unilateral external fixation. There were no deep infections. Refracture was noted in one patient (5%), and two (11%) had delayed union at the target site. One patient developed nonunion at the target site. For the treatment of large bone defects, the callus distraction method may be an alternative option to conventional treatment methods.     

Comparison between upper and lower limb lengthening in patients with achondroplasia: a retrospective study

Lengthening of the humerus is now an established technique. We compared the complications of humeral lengthening with those of femoral lengthening and investigated whether or not the callus formation in the humerus proceeds at a higher rate than that in the femur. A total of 24 humeral and 24 femoral lengthenings were performed on 12 patients with achondroplasia. We measured the pixel value ratio (PVR) of the lengthened area on radiographs and each radiograph was analysed for the shape, type and density of the callus. The quality of life (QOL) of the patients after humeral lengthening was compared with that prior to surgery. The complication rate per segment of humerus and femur was 0.87% and 1.37%, respectively. In the humerus the PVR was significantly higher than that of the femur. Lower limbs were associated with an increased incidence of concave, lateral and central callus shapes. Humeral lengthening had a lower complication rate than lower-limb lengthening, and QOL increased significantly after humeral lengthening. Callus formation in the humerus during the distraction period proceeded at a significantly higher rate than that in the femur. These findings indicate that humeral lengthening has an important role in the management of patients with achondroplasia.     

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.     

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     

Pulsed electromagnetic stimulation of regenerate bone in lengthening procedures

Distraction osteogenesis for limb lengthening represents the treatment of choice in patients with small stature or limb length discrepancies. Bone lengthening and callus formation requires a long therapy. Pulsed electromagnetic fields (PEMF) are normally used to enhance osteogenesis in patients with non-unions. In this study we investigated whether pulsed electromagnetic fields could be used effectively to encourage callus formation and maturation during limb lengthening procedures. Thirty patients underwent bilateral bone lengthening of the humerus, femur or tibia. At day 10 after surgery, PEMF stimulation was started on one side, for 8 hours/day. Stimulated distraction sites exhibited earlier callus formation and progression, and a higher callus density compared to non-stimulated sites. External fixation could be removed on average one month earlier in PEMF stimulated bones. Our results show that the use of pulsed electromagnetic fields stimulation during limb lengthening allows shortening the time of use of the external fixation.     

Preliminary experience with motorized distraction for tibial lengthening

Limb lengthening by callus distraction is commonly performed with the use of external fixation. Lengthening is routinely performed by the patient through small increments throughout the course of a day. Ilizarov has shown that both the rate and frequency of distraction are important factors in the quality of osteogenesis. We report the effect of motorized high frequency distraction for tibial lengthening in comparison with manual low-frequency distraction at the same rate. Manual distraction (0.25 mm four times a day) in a group containing 43 tibiae was compared with motorized distraction (1/1,440 mm 1,400 times a day) in a group containing 27 tibiae. There was no significant difference in time to union or in the incidence of complications.     

Treatment of tibial hemimelia without amputation: preliminary report

Treatment of tibial hemimelia, traditionally, is by amputation. This is not acceptable in our community. Hence we treated our cases without amputation. We treated two cases of type Ia and four cases of type II tibial hemimelia. The age at operation ranged from 3.5 to 13 years For type Ia cases, we applied the Ilizarov external fixator to the femur, fibula and foot to centralize the fibula between the femoral condyles and talus using gradual distraction. The second step was the Brown procedure. Then the fixator was reapplied to correct the deformities. For type II, synostosis of the tibia and fibula was performed followed by differential lengthening. Then we overlengthened the femur. After follow-up for 2-5.5 years, all patients showed improved function and were satisfied. The tibial lengthening ranged from 6 to 8.5 cm, and femoral lengthening ranged from 5 to 7 cm.     

Prediction of Callus Subsidence in Distraction Osteogenesis Using Callus Formation Scoring System: Preliminary Study

Objective

To develop the scoring system which describes both quality and quantity of callus formation to predict the callus subsidence.

Methods

Forty‐seven bony segments with an average lengthening of 5.17 ± 2.83 cm were included. The score was calculated based on the amount of callus classified in five patterns and the summation with the density of the callus classified in four patterns; the total score was 9. Bony subsidence >10% or >10° angulation were considered significant. We analyzed all of the data to find the most appropriate score that would prevent callus subsidence <10% and prevented angulation of the regeneration bone <10 degrees. Data was analyzed by using the receiver operating characteristic (ROC) curve. An area under the curve of 0.9–1 indicated an excellent test, 0.8–0.9 indicated a good test, 0.7–0.8 indicated a fair test, 0.6–0.7 indicated a poor test, and 0.5–0.6 indicated a fail test. The appropriate score for Ilizarov removal was selected from the highest sensitivity and specificity.

Results

Twenty‐two tibia segments and 25 femur segments were included. The mean of bone lengthening was 5.17 ± 2.83 cm (range, 1.6–13.5 cm) and the mean of percentage lengthening was 16.58% ± 10.03% (range, 4.63%–56.84%). The mean distraction period was 5 months. The average months of follow‐up for measurement of bony subsidence was 4.2 months. Mean subsidence was 21.06% (1.54%–57.44%). The mean of callus subsidence was 1.29 ± 1.17 cm (range, 0.03–4.72 cm). There were 32 segments (68%) with callus subsidence greater than 10% and 15 segments (32%) with subsidence less than 10%. The callus subsidence ranged from 0.3 mm to 4.72 cm, with 68% of bony fragments having significant subsidence. Type 5 callus diameter was statistically significant (P < 0.0001) in preventing callus subsidence compared to the other types. Type 4 callus density was statistically significant in preventing callus subsidence compared to the other types (P < 0.0001). The ROC curve with area under the curve 0.961 and sensitivity 0.933 showed that a callus scoring system score >7.5 was effective in preventing significant callus subsidence. When using score 8 as a result from the ROC curve, 73.3% of bony fragment subsidence was <10% with sensitivity 93.3 and specificity 83.2.

Conclusion

Callus diameter 81%–100% and callus density type 4 could prevent significant callus subsidence. Based on the results of the present study we suggest using callus score > 8 to determine the time of Ilizarov removal.

     

Ilizarov's distraction osteogenesis using the mono-fixator system and initial clinical experiences with the injured lower leg

Distraction osteogenesis, as developed by Ilizarov, allows the limbs to be lengthened and intercalary defects to be filled by bone transport without the use of bone grafts. In five patients with traumatic sequelae (fractures of the lower leg), unilateral dynamic mono_fixation and a special distraction apparatus were used for application of the Ilizarov technique. With the distraction device, gradual distraction of the osteotomy surfaces (1/3 mm in three steps per day) is easy for the patients to perform. In three cases distraction osteogenesis was used to correct shortening of the lower leg and in two cases for bridging a tibial defect due to an infection in the plate osteosynthesis. In all cases, the course of treatment and bone healing were uneventful. Based on our first clinical experiences, we believe that mono_fixation provides appropriate stability and the distraction apparatus permits appropriate bone transportation for successful distraction osteogenesis in the tibia.     

Tibio-calcaneo-naviculo-cuboidale arthrodesis: 6 patients followed for 1-8 years

As a salvage procedure for patients with irreparable damage to the peritalar anatomy, we used a new method, the Ilizarov ring fixator, to stabilize a tibio-calcaneo-naviculo-cuboideal (TCNC) arthrodesis after resecting the talus in 6 patients with an average follow-up of 3 years. The tibia was lengthened by callus distraction, mean 6 (3.5-10) cm. Patients with exacerbation of a chronic talar osteomyelitis, symptomatic posttraumatic changes, and those with extremely unstable club feet and talar deformity preventing an adequate reduction of the joint, were successfully treated with the TCNC-fusion. The method permits early weight bearing, while providing stability and compression of the fusion, thereby avoiding further loss of bone stock.     

Pelvic tilt and leg length discrepancy

Pelvic obliquity caused by leg length discrepancy is a problem facing patients with a wide variety of conditions. It is the degree of discrepancy and the growth pattern of the legs that usually govern treatment decisions, with the cause of the discrepancy having little influence. We analyzed the results recorded in 345 patients with pelvic obliquity caused by leg length inequality operated on between 1969 and 1989. In 146 patients a shortening procedure was done and in 199 patients a lengthening procedure. Biological bone growth stimulation did not prove to be predictable and effective in 65 cases. In 134 patients and 138 segments a distraction procedure was performed. In 26 segments the technique was according to Wagner; in 37 cases the Ilizarov fixator was used and in 75 the Orthofix device. Excellent results were obtained in 65% and good results in 23%; the condition became worse in 12%. Analysis of the results justifies the use of epiphysiodesis, shortening osteotomies and bone lengthening according to the biological principles investigated by Ilizarov in the presence of well-defined indications outlined in this report. Patients with a discrepancy of up to 2-3 cm are treated conservatively by shoe lift. For patients with a leg length inequality of 3-5 cm, epiphysiodesis or shortening osteotomy is still a good indication although lengthening procedures can also be performed. Discrepancies between 5 and 15 cm are treated mainly by lengthening operations. New lengthening techniques such as corticotomy and callus distraction, as well as new external fixation systems like Orthofix and Ilizarov, have made bone lengthening a less risky, easier, and more effective procedure. In a growing child, careful clinical and radiological assessment and repeated analysis of past growth in order to predict future growth can provide an exact plan for effective treatment, which often consists of bone lengthening, combined with shortening procedures on the contralateral side to establish leg length equality even in cases when there is 20 cm difference. Surgical treatment can be especially gratifying when anatomical, cosmetic and functional symmetry is restored and a lifetime of shoe lifts, braces or prostheses can be avoided.