Leon Root

Discoid lateral meniscus in children. Long-term follow-up after excision.

We retrospectively reviewed the results for fifteen patients, eight girls and seven boys, who had had a total of eighteen meniscectomies performed for a discoid meniscus at The Hospital for Special Surgery between January 1, 1955, and December 31, 1983. The average age was ten and a half years (range, six to sixteen years) at the time of the operation and twenty-eight years (range, twenty to thirty-six years) at the time of follow-up. The average duration of follow-up was seventeen years (range, eight to twenty-eight years). The primary indication for the meniscectomy was continuing pain in fourteen knees and locking or snapping in three. One patient had tenderness and walked with a limp. A meniscal tear was found in twelve knees at the time of the operation. According to the scale of Ikeuchi, the result was excellent for ten knees, good for three, and fair for five. Of the five patients (five knees) who had a fair result, four had mild intermittent discomfort after strenuous physical activity as well as clicking (three knees) or swelling (one knee), and one had clicking. One of these five patients was subsequently found to have rheumatoid arthritis, and two subsequently had a patellar realignment. No degenerative changes were evident on the roentgenograms of the eight patients (nine knees) for whom they were made at the latest follow-up evaluation.

The Material Basis for Reduced Mechanical Properties in oim Mice Bones

Osteogenesis imperfecta (OI), a heritable disease caused by molecular defects in type I collagen, is characterized by skeletal deformities and brittle bones. The heterozygous and homozygous oim mice (oim/+ and oim/oim) exhibit mild and severe OI phenotypes, respectively, serving as controlled animal models of this disease. In the current study, bone geometry, mechanics, and material properties of 1‐year‐old mice were evaluated to determine factors that influence the severity of phenotype in OI. The oim/oim mice exhibited significantly smaller body size, femur length, and moment of area compared with oim/+ and wild‐type (+/+) controls. The oim/oim femur mechanical properties of failure torque and stiffness were 40% and 30%, respectively, of the +/+ values, and 53% and 36% of the oim/+ values. Collagen content was reduced by 20% in the oim/oim compared with +/+ bone and tended to be intermediate to these values for the oim/+. Mineral content was not significantly different between the oim/oim and +/+ bones. However, the oim/oim ash content was significantly reduced compared with that of the oim/+. Mineral carbonate content was reduced by 23% in the oim/oim bone compared with controls. Mineral crystallinity was reduced in the oim/oim and oim/+ bone compared with controls. Overall, for the majority of parameters examined (geometrical, mechanical, and material), the oim/+ values were intermediate to those of the oim/oim and +/+, a finding that parallels the phenotypes of the mice. This provides evidence that specific material properties, such as mineral crystallinity and collagen content, are indicative and possibly predictive of bone fragility in this mouse model, and by analogy in human OI.

Relationships among musculoskeletal impairments and functional health status in ambulatory cerebral palsy.

Orthopedic surgery for patients with cerebral palsy addresses motion impairments, assuming that this will improve motor function. This study evaluates the relationships among clinical impairment measures with standardized assessments of function and disability as an initial step in testing this assumption. A total of 129 ambulatory children and adolescents across six institutions participated in a prospective evaluation that consisted of passive motion and spasticity examination of the lower extremities, three-dimensional gait temporal-spatial and kinematic analysis, and administration of the Gross Motor Function Measure (GMFM) and the Pediatric Outcomes Data Collection Instrument (PODCI). The analysis found that isolated impairment measures of motion and spasticity were only weakly related to motor function in cerebral palsy and even when averaged across multiple joints yielded no more than a fair correlation with functional scores, nor did a combination of impairments emerge that could predict substantial variance in motor function. These findings suggest that caution should be exercised when anticipating functional change through the treatment of isolated impairment and that addressing multiple impairments may be needed to produce appreciable effects.

A Controlled Study of the Effects of Alendronate in a Growing Mouse Model of Osteogenesis Imperfecta

Recent studies have reported that bisphosphonates reduce fracture incidence and improve bone density in children with osteogenesis imperfecta (OI). However, questions still persist concerning the effect of these drugs on bone properties such as ultrastructure and quality, particularly in the growing patient. To address these issues, the third-generation bisphosphonate alendronate was evaluated in the growing oim/oim mouse, an animal model of moderate- to-severe OI. Alendronate was administered to 6-weekold mice during a period of active growth at a dosage of 73 mg alendronate/kg/day for the first 4 weeks and 26 μg alendronate/ kg/day for the next 4 weeks. Positive treatment effects included a reduction in the number of fractures sustained by the alendronate-treated oim/oim mice compared with untreated oim/oim mice (2.1 ± 2.0 vs 3.2 ± 1.6 fractures per mouse), increased femoral metaphyseal density (0.111 ± 0.02 vs 0.034 ± 0.04 g/cm2), a tendency towards reduced tibial bowing (4.0 ± 3.7 vs 6.1 ± 5.8°), and towards increased femoral diameter (1.22 ± 0.12 vs 1.15 ± 0.11 mm). Potential negative effects included a persistence of calcified cartilage in the treated oim/oim metaphyses compared with treated wildtype (+/+) (33.8 ± 11.1 vs 22.1 ± 10.2%), and significantly shorter femora compared with nontreated oim/oim mice (14.8 ± 0.67 vs 15.3 ± 0.37 mm). This preclinical study demonstrates that alendronate is effective in reducing fractures in a growing mouse model of OI, and is also an important indicator of potential positive and negative outcomes of third-generation bisphosphonate therapy in children with OI.

Osteogenesis Imperfecta: Clinical Evaluation and Management

A reclassification of osteogenesis imperfecta into a congenita type and two tarda types was made on the basis of ninety observed cases. The congenita type, in which the major lesions include blue sclerae and dentinogenesis imperfecta as well as osteoporosis, many fractures, and bowing of the bones, was seen in twelve patients. The two tarda types, differentiated on the basis of the presence or absence of bowing, were seen in forty-three and thirty-five patients, respectively. The frequency of other findings in the three groups is described, as well as differences in management, genetic pattern of inheritance, and course of the disease.

The severely unstable hip in cerebral palsy. Treatment with open reduction, pelvic osteotomy, and femoral osteotomy with shortening.

The results in thirty-one patients with cerebral palsy who had a total of thirty-five severely subluxated or dislocated hips were analyzed retrospectively a mean of seven years after open reduction, pelvic osteotomy, varus rotational osteotomy, and femoral shortening. Preoperatively, twenty-two patients had been unable to stand and thirteen had had pain; the mean acetabular index was 50 degrees, the mean center-edge angle was -19 degrees, and the mean migration index was 74 percent. At the latest follow-up examination, none of the hips were painful. Seven patients had an improvement of one level in their walking ability. All of the patients who were confined to a wheelchair had better sitting balance. The mean acetabular index was 40 degrees, the mean center-edge angle was 18 degrees, and the mean migration index was 25 percent. Four hips were subluxated (two of them posteriorly). One hip was treated with a repeat varus rotational osteotomy. Another hip, which was not dislocated, had a rotational osteotomy for excessive femoral anteversion. Eight femoral heads displayed signs of avascular necrosis. One tibial and two femoral fractures occurred after the cast was removed. Three of the four patients who had a subluxated hip had scoliosis. The combined approach improved coverage of the femoral head and decreased pain in the hip. Even though this procedure can be accompanied by serious complications, we believe that the results justify this extensive approach in these patients.

Resection arthroplasty of the hip for patients with cerebral palsy: an outcome study.

Thirteen patients (18 hips) with cerebral palsy and painful hip subluxation or dislocation underwent proximal femoral resection-interposition arthroplasty (PFRIA) as a salvage procedure for intractable pain or seating difficulty. Eleven patients (14 hips) had a prior failed soft-tissue or bony reconstruction. The average age at surgery was 26.6 years (range, 10.7-45.5 years), and average follow-up was 7.4 years (range, 2.2-20.8 years). All patients/caregivers noted significant improvement in subjective assessment of pain after the surgery. Upright sitting tolerance improved from an average preoperative value of 3.2-8.9 h postoperatively (p < 0.01). Four patients who were unable even to sit in a customized wheelchair before the operation could be easily seated in a custom chair after surgery. Hip range of motion including flexion, extension, and abduction was significantly improved postoperatively (p < 0.05). Single-dose radiation therapy was used postoperatively for five hips and resulted in a significantly lower grade of heterotopic ossification at final follow-up (p < 0.005). Skeletal traction in the postoperative period did not prevent proximal migration of the femur compared with skin traction. Maximal pain relief was achieved at an average of 5.6 months postoperatively (range, 0.03-14 months). Complications included transient postoperative decubitus ulceration (four patients), pneumonia (two patients), and symptomatic heterotopic bone (two patients). The significant improvements in pain management, sitting tolerance, and range of motion suggest that PFRIA is a reasonable salvage procedure for the painful, dislocated hip in cerebral palsy. Resolution of pain may not be immediate, as was noted in this series.

Distal lengthening of the hamstrings in patients who have cerebral palsy. Long-term retrospective analysis.

One hundred and twenty-six patients who had cerebral palsy and who had been managed with distal lengthening of the hamstrings were followed for three to fourteen years so that the long-term results of the procedure could be determined. Twenty-four of sixty-two patients who could not walk before the procedure were able to walk about the house postoperatively. Mild recurvatum developed in only ten patients, and twenty-two patients had a reoperation because of recurrence. Although straight-leg raising and the popliteal angle had improved markedly at one year in all but two patients, both parameters regressed gradually over time. Of several selected variables, only limitation of straight-leg raising preoperatively was of statistical significance (p < 0.001) for the prediction of recurrence. Age, preoperative walking ability, concomitant operations, and postoperative immobilization had no significant effect on the rates of recurrence or recurvatum.

Posterior tibial-tendon transfer in patients with cerebral palsy.

The results of fifty-seven posterior tibial-tendon transfers through the interosseous membrane to the dorsum of the foot that were performed in fifty-one patients who had cerebral palsy, and who were followed for a mean of 9.3 years (range, five to twenty-six years), were evaluated in terms of pattern of gait, alignment of the foot, formation of callus on the sole of the foot, and requirements for bracing. A good or excellent result was achieved in twenty-seven of thirty feet in the hemiplegic patients, twelve of sixteen feet in the paraplegic patients, and two of eleven feet in the quadriplegic patients. We found that in order for the tendon transfer to be successful the foot had to be passively correctable to at least a neutral position and that the tendon had to be passed superficial to the extensor retinaculum and inserted into the lateral cuneiform bone. The heel cord should be lengthened before the tendon transfer.

Measurement of plantar flexor spasticity during treatment with tone-reducing casts.

The purpose of this study was to examine the hypothesis that treatment with short-leg, tone-reducing casts will alter resistance of the plantar flexors to dynamic and static stretch. The torque resisting passive dorsiflexion was measured at angular velocities of 0, 42, 60, and 120°/s for 16 spastic extremities. The short-term changes in dynamic sensitivity and static sensitivity were not significant. Longer-term wearing resulted in significant decreases in both dynamic sensitivity and static sensitivity. Thus, a change in resistance to stretch did occur with longer-term casting.