Comparison of Moseley and Rotterdam straight-line graphs in predicting leg lengths and leg-length discrepancy at maturity.

PURPOSE: One method of predicting leg-length discrepancy at maturity is the Moseley straight-line graph. Beumer et al developed an alternative graph, using a more modern Dutch population. The purpose of this study was to compare the prediction accuracy of these two graphs in a cohort of patients treated at our institution using epiphysiodesis. METHODS: We identified 76 patients treated using epiphysiodesis for leg-length discrepancy who were followed to maturity and had adequate preoperative radiographic assessment for straight-line graph construction. We compared predicted long leg length (after epiphysiodesis), short leg length, and residual leg-length discrepancy to actual outcome for both methods, using both chronological and skeletal ages. RESULTS: Both methods were more accurate using skeletal age rather than chronological age. The Rotterdam graph showed modest improved accuracy compared to the Moseley graph in developmental aetiologies and in Hispanic patients. Using a difference of one centimetre in prediction error as clinically relevant (long leg [after epiphysiodesis], short leg, and leg-length discrepancy in each of the 76 patients, 228 predictions), we found comparable predictions in 171, more accurate prediction using the Rotterdam in 32, and using the Moseley in 25 predictions. CONCLUSIONS: Straight-line graphs provide a generally more accurate prediction of leg lengths at maturity by virtue of multiple preoperative evaluations. The Rotterdam straight-line graph was equal to or superior to the Moseley graph in most patients in this cohort. Use of skeletal age resulted in more accurate predictions than chronological age. Clinicians should remain familiar with the concept and use of the straight-line graph. LEVEL OF EVIDENCE: III, case-control study.

Somatosensory evoked potential monitoring of peripheral nerves during external fixation for limb lengthening and correction of deformity in children.

We undertook a retrospective analysis of 306 procedures on 233 patients, with a mean age of 12 years (1 to 21), in order to evaluate the use of somatosensory evoked potential (SSEP) monitoring for the early detection of nerve compromise during external fixation procedures for limb lengthening and correction of deformity. Significant SSEP changes were identified during 58 procedures (19%). In 32 instances (10.5%) the changes were transient, and resolved once the surgical cause had been removed. The remaining 26 (8.5%) were analysed in two groups, depending on whether or not corrective action had been performed in response to critical changes in the SSEP recordings. In 16 cases in which no corrective action was taken, 13 (81.2%, 4.2% overall) developed a post-operative neurological deficit, six of which were permanent and seven temporary, persisting for five to 18 months. In the ten procedures in which corrective action was taken, four patients (40%, 1.3% overall) had a temporary (one to eight months) post-operative neuropathy and six had no deficit. After appropriate intervention in response to SSEP changes, the incidence and severity of neurological deficits were significantly reduced, with no cases of permanent neuropathy. SSEP monitoring showed 100% sensitivity and 91% specificity for the detection of nerve injury during external fixation. It is an excellent diagnostic technique for identifying nerve lesions when they are still highly reversible.

Adolescents undergoing surgery for idiopathic scoliosis: how physical and psychological characteristics relate to patient satisfaction with the cosmetic result.

STUDY DESIGN: Patient satisfaction with the cosmetic result of spinal fusion surgery was studied in 42 cases of adolescent idiopathic scoliosis. Neutral or dissatisfied patients were compared with satisfied patients on several physical and psychological characteristics. OBJECTIVES: To determine whether adolescents generally report satisfaction with the postoperative appearance of their back after the correction of severe curves and whether preoperative medical and/or psychological factors distinguish between patients who will report satisfaction with the cosmetic surgical result from those who will report neutrality or dissatisfaction. SUMMARY OF BACKGROUND DATA: Previous reports emphasize the need for medical outcomes research that evaluates both patient satisfaction and technical success. Patient satisfaction with spinal surgery has largely been evaluated in retrospective studies and most consistently related to postoperative cosmesis and degree of curve correction. METHODS: Forty-two adolescents with idiopathic scoliosis without comorbidity, who were 12 years 6 months of age or older, and who did not require both anterior and posterior spinal fusion, were studied preoperatively and postoperatively by physical and psychological measurements. RESULTS: Of patients undergoing surgical correction of severe curves, 73% reported satisfaction with the cosmetic result. Neutral or dissatisfied patients were more likely than satisfied patients to have a lower body mass index (P < 0.05), to be younger in menarcheal status (P < 0.05), and have a King II or King III curve type. Preoperative psychological difficulties (P < 0.05) and unmet expectations regarding the postoperative cosmesis (P < 0.05) were more common among neutral or dissatisfied patients. CONCLUSIONS: Most adolescents with idiopathic scoliosis expressed satisfaction with the cosmetic surgical result. Preoperative physical characteristics, psychological difficulties, and unrealistic expectations regarding postoperative cosmesis are associated with patient neutrality or dissatisfaction.

Efficacy of perioperative halo-gravity traction in the treatment of severe scoliosis in children.

SUMMARY: Perioperative halo traction was used in the treatment of severe scoliosis in 19 children. Diagnoses included neuromuscular, idiopathic, and congenital scoliosis. Traction was transferable between the bed and a walker or wheelchair. Thirteen patients had prior spinal surgery, and most required osteotomy. Traction was used for 6 to 21 weeks. All patients underwent spinal fusion surgery after traction, with instrumentation used in 15 patients. Improvement was achieved in all patients. The Cobb angle improved 35% from an average 84 degrees before traction (range 63 degrees -100 degrees ) to 55 degrees preceding fusion. Trunk decompensation improved in all patients. Trunk height increased 5.3 cm in traction. Response to traction did not correlate with diagnosis, patient age, or prior surgery. There were no neurologic complications. Perioperative halo-gravity traction improves trunk balance and frontal and sagittal alignment in children with severe spinal deformity. Surgical fusion was enhanced by the improved alignment, and neurologic injury was avoided.

Effect of rhythm and level of distraction on muscle structure: an animal study.

To determine the optimal rhythm of distraction and level of osteotomy for maximal muscle preservation during limb lengthening, histologic and ultrastructural analysis of the peroneus tertius muscle was performed in 46 goats. Thirty-nine animals with 20% or 30% tibial lengthening at the rate of 0.75 mm per day at each osteotomy level were divided in two groups. The first group included 15 animals undergoing tibial middiaphyseal lengthening with automated distractor producing one (n = 5), four (n = 5), or 720 (n = 5) increments per day. The second group included 24 animals in which lengthening was performed at the proximal (n = 4), middle (n = 6), distal (n = 6), or double (n = 8) level of the tibia with distraction rhythm of three times per day. The remaining seven animals served as controls. Histomorphologic features of the lengthened muscles were characterized by a polymorphous appearance with foci of necrosis, atrophy, and sclerosis scattered among apparently normal muscle fibers. The intensity and dispersion of degenerative changes were in direct proportion to the amount of lengthening but in reverse proportion to the frequency of distraction. Tibial lengthening at the diaphysis caused intense fibroblast proliferation and remarkable muscle sclerosis, whereas metaphyseal distraction was associated with a predominance of muscle tissue regeneration over atrophy and sclerosis. Bifocal lengthening and a more fractionated rhythm of distraction were associated with enhanced preservation of existing muscle fibers and greater regenerative activity of the muscle.

Developmental coxa vara associated with spondylometaphyseal dysplasia (DCV/SMD): "SMD-corner fracture type" (DCV/SMD-CF) demonstrated in most reported cases.

BACKGROUND: This paper reports three children with short stature: developmental coxa vara unilateral in the first case and bilateral in the other two; somewhat squared and "ovoid" vertebral bodies in the first patient, and normal to slightly tall vertebral bodies in the third; metaphyseal changes in some long tubular bones including bone fragments similar to the corner fractures seen in child abuse in all three patients. MATERIALS AND METHODS: The first and second patients were sisters; their mother, also quite short, had surgical procedures in early life for bilateral "coxa vara"; their brother, also of short stature, had bilateral coxa valga with otherwise normal femoral heads and necks, and mild metaphyseal changes associated with two minute "corner fractures" in the proximal metaphysis of the left tibia. RESULTS: A review of reported cases of developmental coxa vara associated with spondylometaphyseal dysplasia revealed that simulated corner fractures were present in most instances.

Syme amputation for the treatment of fibular deficiency. An evaluation of long-term physical and psychological functional status.

BACKGROUND: Syme amputation is an accepted treatment for fibular deficiency. With improvement in limb-lengthening procedures, there has been renewed interest in limb salvage for these patients. The purpose of the present study was to evaluate the physical and psychological results in ten young adults who had had a Syme amputation for the treatment of fibular deficiency when they were children. METHODS: The evaluation consisted of physical examination, prosthetic assessment, psychological testing, and physical performance testing of knee extension and flexion with use of a Cybex-II dynamometer. RESULTS: Five patients reported no difficulty with the involved limb since the Syme amputation, four had had minor secondary procedures (three medial distal femoral or proximal tibial hemiepiphyseodeses, one reconstruction with an autologous patellar ligament graft, one revision of the stump, and one tibial osteotomy) on the affected extremity, and one had mild instability of the knee that had been treated nonoperatively. All ten patients had an appropriate, functional Syme prosthesis, and none reported difficulty with walking or running. On psychological testing, this group generally did not differ from the norm with regard to occupational satisfaction, personal growth, relationships with family members and peers, and recreational behavior. The patients' overall assessment of self-reported quality of life and self-esteem was similar to that of normative adult samples. In general, these patients were leading active, productive lives and had always done so. CONCLUSIONS: On the basis of the results of this study, we concluded that young adults who have had a Syme amputation apparently are not limited in their ability to pursue and achieve personal goals. In order to justify recommending limb salvage rather than early Syme amputation for the treatment of fibular deficiency, the results of multistaged lengthening and reconstruction would have to match the functional, psychological, and cost-effective results for the patients whom we studied, who had had a Syme amputation.

Outcome of ultrasonographic hip abnormalities in clinically stable hips.

A retrospective review was performed of 192 newborn hips in 112 patients referred for hip evaluation. The average age at presentation was 12.7 days, with average radiographic follow-up of 15.9 months. Inclusion criteria for our study were a normal physical examination of the hip without evidence of instability and an ultrasound examination that was considered abnormal. Pavlik harness treatment was chosen at the discretion of the treating physician. At final follow-up, dysplasia was defined as greater than two standard deviations above the mean acetabular index (AI) for age. Group I consisted of 43 hips that had Pavlik treatment, and group II consisted of 149 hips that did not receive treatment. There was no difference in these two groups with respect to risk factors for dysplasia or the initial abnormalities seen on ultrasound evaluation, although patients in group I had less coverage of the femoral head during stress maneuvers. No hip in group I and two (1.3%) hips in group II were considered dysplastic (AI > 2 SD) at final radiographic follow-up (p > 0.10). There was no correlation between the severity of the ultrasound abnormality at birth and the subsequent presence of dysplasia (p > 0.10). The two hips considered dysplastic on radiograph were not being actively treated. When the hip examination of a newborn hip younger than 1 month is normal, a screening ultrasound does not appear to predict accurately subsequent hip dysplasia. In this specific setting, an initial screening ultrasound may be too sensitive and does not appear warranted.

Orthopedic management of neuromuscular disorders in children.

In many cases, the orthopedic surgeon may be the first consultant requested to assess complaints of lower extremity weakness or deformity to result from such conditions and must remain alert to the primary diagnosis. In addition, the orthopedic surgeon should be prepared to guide appropriate physical therapy, prescribe orthotics, and perform surgery to improve function, prevent deformity, or provide comfort when necessary. Most deformities of the extremities result from a combination of muscle weakness and imbalance, and surgical procedures are aimed at correcting existing deformity and rebalancing existing musculature by release or transfer. Skeletally immature patients with neuromuscular disorders are also susceptible to the development of scoliosis, which may impair comfortable sitting or already compromised pulmonary function. This article reviews the clinical manifestation and orthopedic management of Duchenne's muscular dystrophy, spinal muscular atrophy, facioscapulohumeral dystrophy, and Charcot-Marie-Tooth disease.

Histomorphometry of distraction osteogenesis in a caprine tibial lengthening model.

Standardized histomorphometry of bone formation and remodeling during distraction osteogenesis (DO) has not been well characterized. Increasing the rhythm or number of incremental lengthenings performed per day is reported to enhance bone formation during limb lengthening. In 17 skeletally immature goats, unilateral tibial lengthenings to 20 or 30% of original length were performed at a rate of 0.75 mm/day and rhythms of 1, 4, or 720 times per day using standard Ilizarov external fixation and an autodistractor system. Two additional animals underwent frame application and osteotomy without lengthening and served as osteotomy healing controls. Histomorphometric indices were measured at predetermined regions from undecalcified tibial specimens. Within the distraction region, bone formation and remodeling activity were location dependent. Intramembranous bone formed linearly oriented columns of interconnecting trabecular plates of woven and lamellar type bone. Total new bone volume and bone formation indices were significantly increased within the distraction and osteotomy callus regions (Tb.BV/TV, 226% [p < 0.05]; BFR/BS, 235-650% [p < 0.01]) respectively, compared with control metaphyseal bone. Bone formation indices were greatest adjacent to the mineralization zones at the center of the distraction gap; mineral apposition rate 96% (p < 0.01); mineralized bone surfaces 277% [p < 0.001]); osteoblast surfaces 359% [p < 0.001]); and bone formation rate (650% [p < 0.01]). There was no significant difference (p < 0.14; R = 0.4) in the bone formation rate of the distracted callus compared with the osteotomy control callus. Within the original cortices of the lengthened tibiae, bone remodeling indices were significantly increased compared with osteotomy controls; activation frequency (200% [p < 0.05]); osteoclast surfaces (295% [p < 0.01]); erosion period (75%); porosity (240% [p < 0.001]). Neither the rhythm of distraction nor the percent lengthening appeared to significantly influence any morphometric parameter evaluated. Distraction osteogenesis shares many features of normal fracture gap healing. The enhanced bone formation and remodeling appeared to result more from increased recruitment and activation of bone forming and resorbing cells rather than from an increased level of individual cellular activity.

Focal fibrocartilaginous dysplasia in the upper extremity.

Focal fibrocartilaginous dysplasia is a benign lesion known to cause tibia vara in young children. To date, this lesion has been recognized in only the proximal medial tibia. This study reports two additional cases of focal fibrocartilaginous dysplasia occurring in the long bones of the upper extremity. The clinical presentation, radiographic appearance, histopathology, and natural history of focal fibrocartilaginous dysplasia in the humerus and ulna are analogous to published descriptions involving the tibia. Spontaneous resolution of the lesion and the resultant angular deformity is possible but not entirely predictable. Limb-length discrepancy should be anticipated.

Monitoring peripheral nerve function during external fixation of upper extremities.

Limb lengthening of the upper extremity using external fixation devices is associated with a high risk of neurovascular impairment. To aid early detection of nerve injury, intraoperative monitoring of neural function was performed in five patients undergoing Ilizarov-type circular external-fixator application. The apparatus was applied to the humerus in two cases and to the forearm in the other three cases. The function of ulnar, median, and radial nerves was assessed continuously throughout the surgery by using sensory-evoked potential (SEP) monitoring technique. The responses were elicited by stimulation of these nerves in the distal forearm with recording at Erb's point and over the anterior cervical spine. During apparatus application, radial-response attenuation was identified in two instances. No corrective actions were performed in one case, and the patient had symptoms of radial nerve deficit postoperatively. In the other case, prompt removal of the offending half-pin after the detection of electrophysiologic abnormalities resulted in subsequent response restoration and the avoidance of postoperative nerve dysfunction. Sensory-evoked potential monitoring proved to be a reliable indicator of nerve compromise during external fixation of upper extremities and may be considered a valuable surgical adjunct.

Effects of external fixation and limb lengthening on peripheral nerve function.

To identify factors affecting peripheral nerve function during limb lengthening, serial somatosensory evoked potentials studies were performed in 18 goats and correlated with gross appearance of the soft tissues at necropsy. In 15 goats, a 20% or 30% tibial lengthening was done using the Ilizarov apparatus at a rate of 0.75 mm per day and rhythm of 1, 4, or 720 times per day. Three animals served as frame/corticotomy controls. Seven lengthened and 2 control animals maintained normal somatosensory evoked potentials throughout the study. At necropsy, the peroneal and tibial nerves appeared grossly normal. In one control animal with irreversible loss of evoked potentials documented intraoperatively, peroneal nerve impalement by a transfixion wire was identified at necropsy. Eight lengthened animals experienced significant changes of peroneal nerve conduction. In 6 of these 8 animals, transfixion wires were found to be disrupting the nerve in some way. In the remaining 2 animals, no offending wires were identified, but there was extensive diffuse soft tissue fibrosis within the extremity. The rhythm of distraction did not have an important influence on evoked potential changes during the course of distraction. Although there was a correlation between the amount of lengthening performed and the degree of evoked potentials deterioration, the anatomic relationship between the wires and nerves was a more important factor in the development of these abnormalities.

Cervical kyphosis in patients who have Larsen syndrome.

Four patients who had Larsen syndrome and cervical kyphosis were managed operatively and followed for an average of seventy months (range, forty to ninety-two months). The preoperative cervical kyphosis ranged from 35 to 65 degrees. The patients had had a posterior cervical arthrodesis alone when they were infants, at an average age fo fourteen months (range, ten to sixteen months). In three infants, the kyphosis either stabilized (one patient) or reversed into lordosis (two patients). Thus, the kyphosis corrected gradually by continued anterior growth in the presence of a solid posterior fusion. In the fourth infant, the kyphosis progressed to 110 degrees because of pseudarthrosis. This child had anterior decompression and arthrodesis for an acute neurological deficit. We believe that cervical kyphosis is sometimes present but not diagnosed in patients who have Larsen syndrome. Early diagnosis followed by operative stabilization should help such patients avoid neurological deficits. Posterior cervical arthrodesis alone, performed in infancy, provided stability and the opportunity for the gradual correction of the deformity by continued anterior growth in three of our four patients.

Intraoperative SSEP monitoring during external fixation procedures in the lower extremities.

The efficacy of somatosensory evoked potentials (SSEPs) to detect acute peripheral nerve injury during external-fixator application in the lower extremities was evaluated in 40 children with 42 Ilizarov surgical procedures. The study included patients who were either clinically normal or who had preexisting neuropathy but consistent and reliable SSEP responses preoperatively. SSEPs were recorded from the popliteal fossa and lumbar regions after alternating stimulation of the peroneal and posterior tibial nerves at the ankle. SSEP changes due to anesthesia, Ilizarov apparatus application, and other intraoperative variables are described. Significant deterioration or total loss of SSEP response during surgery occurred in four cases. Two of these patients were normal preoperatively and had symptoms of neurologic deficit postoperatively; the other two had exacerbations of pre-existing neuropathy. In general, the peroneal nerve was at greater risk for injury during surgery. SSEP monitoring proved to be technically feasible in external-fixation procedures on the lower extremities and may be a practical tool for detection of intraoperative nerve compromise.

Syringomyelia and scoliosis in children.

We reviewed 28 patients < 18 years of age with scoliosis and syringomyelia. Children with scoliosis and syringomyelia had an equal incidence of left- and right-sided curves with a normal sagittal alignment. Most were first seen at Risser 0 with significant curves, and curve progression occurred in half of the patients. Bracing was not effective in preventing curve progression. Neurologic signs, present in most children, stabilized after syrinx drainage. Neither the sex or age of the child, nor the type of curve, nor the drainage of the syrinx was predictive of curve progression.

Computer-assisted surgery planning for lower extremity deformity correction by the Ilizarov method.

Starting in 1952, Prof. Gavril Ilizarov, a Russian orthopedic surgeon, devised a complex method of long bone deformity correction using an external bone fixation system consisting of rings and wires. We have developed a computer-assisted surgery planning system to aid in correction using the Ilizarov method. The hardware for the system is composed of an ultrasonic digitizer as input device, an HI plotter as output device, a 386/486 personal computer with super VGA monitor, and a mouse interfacing between user and computer. The software includes two separate programs. The main program is a menu-driven two-dimensional graphics program, which divides the planning procedure into several major stages, including preoperative planning and postoperative verification. The second program uses the information generated from the first program to create an image of the ideal three-dimensional frame construction to give a general impression of the appearance of the constructed frame.

Somatosensory evoked potential evaluation of acute nerve injury associated with external fixation procedures.

The effects of different mechanisms of acute nerve injury on peripheral nerve function during K wire application and 1 stage limb lengthening were evaluated prospectively in 24 goats using somatosensory evoked potentials. Stable somatosensory evoked potential recordings throughout 3-day experiments were obtained in animals with wires placed at a distance from or directly adjacent to a nerve but without producing any tension or pressure. Complete loss of the peroneal nerve somatosensory evoked potentials occurred if this nerve was perforated by wire, underwent excessive pressure by wire, or had been over-stretched due to acute 10% limb lengthening. Acute distraction resulted only in peroneal nerve dysfunction, while the tibial nerve was relatively unaffected. Although somatosensory evoked potential changes were not specific for the type of injury produced and the time of waveform disappearance varied, significant somatosensory evoked potential changes (> 50% amplitude reduction, > 10% latency delay or both) were seen within the first 15 minutes after injury in 90% of the cases. The somatosensory evoked potential changes did not reverse if the offending wire or distraction was left in place for the full duration of the experiment. Variable nerve conduction recovery was observed in all animals who had the insult removed immediately after the somatosensory evoked potentials disappearance. The greatest improvement occurred after discontinuation of nerve distraction. The worst somatosensory evoked potential waveform recovery was noted in animals with nerve perforation. Intraoperative somatosensory evoked potential monitoring proved to be a reliable and useful technique for earlier detection of acute nerve injury during external fixation procedures.

Spontaneous resolution of congenital anterolateral bowing of the tibia.

In a series of 43 patients diagnosed with congenital anterolateral bowing of the tibia or congenital pseudarthrosis of the tibia treated between 1980 and 1992, the deformities corrected themselves spontaneously in five patients who had no other congenital abnormalities or evidence of neurofibromatosis. At an average follow-up of 58 months (average age at follow-up 80 months), the only residual deformity seen was a limb-length discrepancy in patients with unilateral involvement. In patients with subperiosteal callus formation on the posteromedial concavity of this deformity and an uninvolved fibula, no treatment appears necessary, as this deformity will spontaneously resolve.