John E. Herzenberg

Femoral lengthening over an intramedullary nail : A matched-case comparison with Ilizarov femoral lengthening

Twenty-nine patients (thirty-two femora) had femoral lengthening over an intramedullary nail, with the nail and the external fixator applied concomitantly at the time of the femoral osteotomy. After gradual distraction at a rate of one millimeter per day, the nail was locked and the fixator was removed. The mean age was twenty-six years (range, ten to fifty-three years), and the mean amount of lengthening was 5.8 centimeters (range, two to thirteen centimeters). For comparison, thirty-one patients (thirty-two limbs) who had had standard Ilizarov femoral lengthening were matched with the group that had had lengthening over an intramedullary nail; the matching was performed on the basis of the amount of lengthening, the age of the patient, the etiology of the indication for lengthening, and the level of difficulty of the procedure. Lengthening over an intramedullary nail reduced the average duration of external fixation by almost one-half. The radiographic consolidation index (the number of months needed for radiographic consolidation for each centimeter of lengthening) for the limbs that had had lengthening over an intramedullary nail was reduced significantly (p < 0.001) compared with that for the matched-case group. The range of motion of the knee returned to normal a mean of 2.2 times faster in the group that had had lengthening over an intramedullary nail. There were six refractures of the distraction bone in the matched-case group. In the group that had had lengthening over an intramedullary nail, one nail and one proximal locking screw failed. The over-all rate of complications was 1.4 per cent in the group that had had lengthening over an intramedullary nail compared with 1.9 per cent in the matched-case group. With the numbers of patients available for study, we could not detect a significant difference between the groups with respect to the operative time (p = 0.124); however, the cost of treatment and the estimated blood loss were higher in the group that had had lengthening over an intramedullary nail. On the basis of clinical and radiographic criteria, there were twenty-three excellent, seven good, and two fair results in the group that had had lengthening over an intramedullary nail compared with twenty-six excellent, four good, and two fair results in the matched-case group (p = 0.37). The advantages of lengthening over an intramedullary nail include a decrease in the duration of external fixation, protection against refracture, and earlier rehabilitation.

Multiplier method for predicting limb-length discrepancy.

Background: In patients with a congenital or developmental limb-length discrepancy, the short limb grows at a rate proportional to that of the normal, long limb. This is the basis of predicting limb-length discrepancy with existing methods, which are complicated and require multiple data points. The purpose of our study was to derive a simple arithmetic formula that can easily and accurately predict limb-length discrepancy at skeletal maturity. Methods: Using available databases, we divided the femoral and tibial lengths at skeletal maturity by the femoral and tibial lengths at each age for each percentile group. The resultant number was called the multiplier. Using the multiplier, we derived formulae to predict the limb-length discrepancy and the amount of growth remaining. We verified the accuracy of these formulae by evaluating two groups of patients with congenital shortening who were managed with epiphysiodesis or limb-lengthening. We also calculated and compared the multipliers for other databases according to radiographic, clinical, and anthropological lower-limb measurements. Results: The multipliers for the femur and tibia were equivalent in all percentile groups, varying only by age and gender. Because congenital limb-length discrepancy increases at a rate proportional to growth, the discrepancy at maturity can be calculated as the current discrepancy times the multiplier for the current age and the gender. This calculation can be performed with use of a single measurement of limb-length discrepancy. For progressive developmental (noncongenital) discrepancies, the discrepancy at skeletal maturity can be calculated as the current discrepancy plus the growth inhibition times the amount of growth remaining. The timing of the epiphysiodesis can also be calculated with the multiplier. The predictions made with use of the multiplier method correlated well with those made with use of the Moseley method as well as with the actual limb-length discrepancy in both the limb-lengthening and epiphysiodesis groups. The multipliers derived from the radiographic, clinical, and anthropological measurements of femora and tibiae were all similar to each other despite differences in race, ethnicity, and generation. Conclusions: The multiplier method allows for a quick calculation of the predicted limb-length discrepancy at skeletal maturity, without the need to plot graphs, and is based on as few as one or two measurements. This method is independent of percentile groups and is the same for the prediction of femoral, tibial, and total-limb lengths. The multiplier values are also independent of generation, height, socioeconomic class, ethnicity, and race. We verified the accuracy of this method clinically by evaluating patients who had been managed with limb-lengthening or epiphysiodesis. The method was also comparable with or more accurate than the Moseley method of limb-length prediction.

Emergency transport and positioning of young children who have an injury of the cervical spine: the standard backboard may be Hazardous

In ten children who were less than seven years old, an unstable injury of the cervical spine was found to have anterior angulation or translation, or both, on initial lateral radiographs that were made with the child supine on a standard flat backboard. In all ten patients, extension was the proper position for reduction of the injury of the cervical spine. Young children have a large head in comparison with the rest of the body. When a young child is positioned on a standard backboard, the neck may be forced into relative kyphosis. Supine and upright lateral radiographs that were made of seventy-two children who did not have a fracture also demonstrated more relative cervical kyphosis in younger children when they were in the supine position. Calculations from anthropometric data documented disproportionate rates of growth of the head and the chest. The circumference of the head grows logarithmically, but the circumference of the chest grows linearly. This disproportionate growth causes young children to have a relatively large head. When they lie supine, the neck is flexed. To prevent undesirable cervical flexion in young children during emergency transport and radiography, a standard backboard can be modified to provide safer alignment of the cervical spine. This can be accomplished by the use of a recess for the occiput to lower the head or of a double mattress pad to raise the chest.

Intramedullary Infections Treated With Antibiotic Cement Rods: Preliminary Results in Nine Cases

The treatment of intramedullary infections after nailing usually includes removal of the rod, debridement of the canal, and, in many cases, insertion of antibiotic-impregnated cement beads. These beads offer no mechanical support and are difficult to remove if left in place for more than 2 weeks. We present an alternative for filling the medullary canals noncollapsible dead space with an antibiotic-impregnated cement rod. This rod can be custom-made at the time of surgery, using different diameter chest tubes as molds and embedding a 3-mm beaded guidewire within the cement. The smooth molded surface of this nail makes extraction of the cement rod relatively easy. The cement rod also provides some limited temporary support to the fracture or nonunion site while the infection is being treated. After 6 weeks, the rod can be removed and replaced with a definitive metal intramedullary nail, with or without bone grafting to treat the previously infected fracture or nonunion site. We retrospectively reviewed nine cases of intramedullary infection treated with antibiotic-impregnated molded cement rods. These included six femora, two tibiae, and one humerus. The cause of infection was lengthening or transport over nail in six cases, fixator-augmented nailing of osteotomies in two, and fracture fixation in one. The follow-up period after surgery ranged from 38 to 48 months. No recurrent infection occurred during this follow-up period, and no patient required antibiotics after the rod was removed. In all cases, the canal cultures were negative after rod removal. The cement rod was removed between 29 and 753 days after implantation. Fracture of the rod occurred in one case in which the rod was left in place for more than 1 year. We conclude that this method is a relatively simple and inexpensive alternative for the treatment of intramedullary infections.

Nerve lesions associated with limb-lengthening.

BACKGROUND Nerve injury is one of the most serious complications associated with limb-lengthening. We examined the risk, assessment, and treatment of nerve lesions associated with limb-lengthening. METHODS We retrospectively studied the records on 814 limb-lengthening procedures. Nerve lesions were defined by clinical signs and symptoms of motor function impairment, sensory alterations, referred pain in the distribution of an affected nerve, and/or positive results of quantitative sensory testing with use of a pressure specified sensory device. RESULTS Seventy-six (9.3%) of the limbs had a nerve lesion. Eighty-four percent of the nerve lesions occurred during gradual distraction, and 16% occurred immediately following surgery. The pressure specified sensory device showed 100% sensitivity and 86% specificity in the detection of nerve injuries. The patients in whom the lesion was diagnosed with this method, or with this method as well as with nerve conduction studies, had significantly faster recovery than did those diagnosed on the basis of clinical symptoms or nerve conduction studies alone (p = 0.02). Patients undergoing double-level tibial lengthening and those with skeletal dysplasia were at higher risk for nerve lesions (77% and 48%, respectively). Nerve decompression was performed in fifty-three cases (70%). The time between the diagnosis and the surgical decompression was strongly associated with the time to recovery (p = 0.0005). Complete clinical recovery was achieved in seventy-four of the seventy-six cases. CONCLUSIONS Early detection based on signs and symptoms or testing with a pressure specified sensory device improves the prognosis for nerve injury that occurs during limb-lengthening. Of the methods that we used to identify neurologic compromise, testing with the pressure specified sensory device was the most sensitive. Aggressive early treatment (slowing the rate of lengthening and/or performing decompression) allows continued lengthening without incurring permanent nerve injury. When indicated, decompression of the affected nerve should be performed as soon as possible, thereby improving the chances of and shortening the time to complete recovery.

Treatment of Malunion and Nonunion at the Site of an Ankle Fusion with the Ilizarov Apparatus

BACKGROUND Malunion and nonunion of an ankle fusion site are associated with pain, osteomyelitis, limb-length discrepancy, and deformity. The Ilizarov reconstruction has been used to treat these challenging problems. METHODS We reviewed the results in twenty-one ankles that had undergone a revision of a failed fusion, with simultaneous treatment of coexisting pathologic conditions, with use of the Ilizarov technique. Eight patients had undergone ankle fusion only, eleven had undergone ankle and subtalar fusion, and two had undergone pantalar fusion. Eighteen patients with an average limb-length discrepancy of 4 cm underwent limb lengthening simultaneously with the revision surgery. The average patient age was forty years. Indications for treatment were malunion (eleven patients), aseptic nonunion (eight patients), and infected nonunion (two patients). Clinical, subjective, objective, gait, and radiographic analyses were performed after an average duration of follow-up of 83.4 months. RESULTS Solid union was achieved in all ankles. The functional result was excellent for fifteen patients, good for three, fair for two, and poor for one. The bone result was excellent for ten ankles, good for nine, fair for one, and poor for one. All eighteen patients who underwent gait analysis had a heel-to-toe progression gait, and twelve achieved normal walking velocity with their shoes on. A plantigrade foot was achieved in each case, and only two patients had >5 degrees of residual deformity. During the Ilizarov treatment, forty-one minor complications (treated conservatively) and twenty major complications (treated surgically) occurred. After removal of the circular frame, seven other complications, which required four additional operations, occurred. CONCLUSIONS In patients with a failed ankle fusion, infection, limb-length discrepancy, and foot deformity can be addressed simultaneously with use of the Ilizarov apparatus to achieve a solid union and a plantigrade foot, usually with a clinically satisfactory result.

Ponseti management of clubfoot in older infants.

Treatment of clubfoot with the Ponseti method is successful when performed immediately after birth. We treated 23 infants (36 feet) who presented to us after casting, applied at other institutions, failed or after 3 months of age. Twenty-two infants had serial casting started during the first 2 months, and one infant who was 6 months old at presentation had not received previous treatment. The original orthopaedists of 18 patients advised posteromedial release. The parameter studied was the need for posteromedial release (ie, failure of Ponseti casting and percutaneous Achilles tenotomy to obtain satisfactory clinical appearance). Only one (2.8%) of 36 feet required open surgical release (posterior only). Thirty-five feet required percutaneous Achilles tenotomy. A mean of six Ponseti casts were applied before tenotomy. Two feet (two infants) required anterior tibialis transfer for mild relapse; three other feet (two infants) required repeat casting for mild relapse. Most pediatric orthopaedists think that successful clubfoot casting depends on treatment started immediately after birth. Our data suggest that older infants with clubfoot can be treated successfully without extensive surgery. Our results in older infants are similar to the results of a previous study we conducted with younger infants. In that study, one (2.9%) of 34 feet required posteromedial release surgery.Level of Evidence: Therapeutic study, Level IV (Case series). See the Guidelines for Authors for a complete description of levels of evidence.

Osteoid osteoma and osteoblastoma of the spine

Eleven patients with spinal osteoid osteoma and six patients with spinal osteoblastoma treated between 1975 and 1990 were reviewed to characterize the tumors as they affect the spine and to define the important differences between the two tumors. All patients with cervical osteoid osteoma presented with pain, limited range of motion of the neck, and torticollis. Four osteoblastomas had soft-tissue components in the epidural space, necessitating dissection of the tumor from the dura. No soft-tissue component was found in any of the osteoid osteomas. Our results were similar to a metaanalysis of the clinical, radiographic, and surgical findings of all published cases of spinal osteoid osteoma and osteoblastoma. Important features that have not been emphasized in the literature are the high incidence of torticollis with cervical lesions and the frequent association of epidural invasion with osteoblastoma. Surgeons treating osteoblastoma of the spine should be prepared to dissect tumor from the dura.

Knee range of motion in isolated femoral lengthening.

Twenty-five patients underwent isolated Ilizarov femoral lengthenings (mean lengthening, 6 cm). A retrospective review of the charts showed the specific changes in knee range of motion (ROM) during lengthening, after removal of the frame, and at the final follow-up examination. A decrease in ROM was seen during lengthening to an average minimum of 37 degrees +/- 15 degrees. Toward the end of the consolidation phase, improvement to 69 degrees +/- 28 degrees was noted. A progressive increase in ROM was seen after frame removal. Mean preoperative flexion was 127 degrees +/- 16 degrees, and at follow-up flexion was 122 degrees +/- 23 degrees (p = 0.191). Of the five patients who did not achieve 120 degrees flexion at the final follow-up examination, three had a diminished ROM (average, 107 degrees) at the outset. Two patients lost more than 15% of their preoperative flexion. There was no correlation noted between worst ROM (during lengthening) and final ROM at the last follow-up examination.

Clubfoot analysis with three-dimensional computer modeling.

Which way are the bones rotated in a club-foot? This question has long been debated by clubfoot surgeons. Opinions have been based on observations from surgery, radiographs, and autopsies. These methods all have pitfalls and are subject to misinterpretation. We used three-dimensional computer modeling to analyze histologic sections of a newborn clubfoot and a newborn normal foot. Relative to the bimalleolar axis in the axial plane, the normal talus demonstrated 5° of internal rotation of its body and 25° internal rotation of its neck. The clubfoot talus showed 14° of external rotation of its body and 45° of internal rotation of its neck. The calcaneus was externally rotated 5° in the normal foot and internally rotated 22° in the clubfoot.