Robert D. Fitch

Tibial tubercle avulsions

Avulsion of the tibial tubercle is not common. Sixteen cases are recorded, with a mean age of 15 years 2 months. All subjects were boys, 15 cases were left-sided, and three individuals had other associated knee injuries. All were treated operatively. Immobilization time aver-aged 4.9 weeks, with a mean follow-up of 15 months. Fourteen subjects regained full motion and activity. Three complications were noted, none of which was associated with this injury. This injury occurs in a vulnerable period when the physis is undergoing physiologic changes that weaken its ability to resist tensile loading.

Severin Classification System for Evaluation of the Results of Operative Treatment of Congenital Dislocation of the Hip. A Study of Intraobserver and Interobserver Reliability

The Severin classification system frequently is used to evaluate the radiographic results of operations performed for the treatment of congenital dislocation of the hip. However, the reliability of this classification scheme has not been established, to our knowledge. Ideally, a classification system should be validated before it is used to promote therapeutic guidelines or to compare results of treatment; the purpose of the present study was to establish the intraobserver and interobserver reliability of the Severin classification system. Four blinded raters and the operating surgeon independently used the Severin system to evaluate the most recent radiographs of thirty-seven children (fifty-six hips) who had been managed, an average of nine years previously, with a medial open reduction for congenital dislocation of the hip. Three of the raters evaluated the same radiographs again under similar testing circumstances eight weeks later. Ten paired interobserver and three intraobserver comparisons then were analyzed with use of the Cohen kappa coefficient (&kgr;). The average kappa coefficient for the six pairwise comparisons between the four blinded raters was 0.15 (range, -0.05 to 0.42) when all Severin classes were analyzed independently. The average kappa coefficient for the four pairwise comparisons between the blinded raters and the operating surgeon was even lower (0.02). The kappa coefficients for the three intraobserver comparisons were 0.20, 0.38, and 0.44 (average, 0.34). Kappa analysis demonstrated variable and low levels of agreement when the Severin system was used to rate the results of operations performed for the treatment of congenital dislocation of the hip. We believe that the unadjusted kappa coefficient should indicate excellent agreement (&kgr; > 0.75) for all comparisons if this system is to be used for the evaluation of clinical results. The unacceptably low levels of intraobserver and interobserver reliability call into question the clinical conclusions of reports in which the Severin system has been used as the basis of proof.

Knee arthrodesis with circular external fixation.

Knee arthrodesis can enable limb salvage in patients with disability secondary to trauma, infected total knee arthroplasty, pyarthrosis, and other complications. Historically, intramedullary nailing has resulted in the highest overall knee fusion rates. However, intramedullary nailing is relatively contraindicated in the presence of active infection. Nineteen patients who underwent knee arthrodesis with circular external fixation were studied retrospectively. Postoperative radiographs were evaluated for evidence of bony fusion, which was defined as trabecular bridging between the femur and tibia. Patients were interviewed and graded using the functional assessment portion of the Knee Society clinical rating system. Fusion was successful in 13 of 19 (68%) patients. Overall, patients spent an average of 4 months 8 days wearing the circular external fixator. Average time to radiographic and clinical evidence of arthrodesis (defined as lack of motion across the fusion site) was 4 months 18 days. No patient with successful fusion considered himself or herself housebound. All but one of these patients require some form of assistive device for ambulation. Complications occurred in 16 of 19 (84%) patients overall. Superficial pin tract infection (55%) and nonunion (32%) were the most common. Circular external fixation is an effective method for obtaining knee arthrodesis in patients who are not good candidates for intramedullary nailing.

Results after replantation and revascularization in the upper extremity in children.

The rates of survival of the amputated part and the functional outcomes were studied retrospectively after seventy-three replantations and eighty-nine revascularizations in the upper extremity in 120 children. All operations were performed between January 1974 and December 1988 after partial and complete amputations at various levels. The ages of the patients ranged from three days to sixteen years. The average duration of follow-up was thirty-six months (range, fourteen months to seven years) for the patients who had had a replantation and thirty months (range, fourteen months to eight years) for the patients who had had a revascularization. The rate of survival of the amputated part was significantly higher (p < 0.0002) after revascularization (seventy-eight parts [88 per cent]) than after replantation (forty-six parts [63 per cent]). There was no association, for either group, between survival and the preoperative duration of ischemia, the level of the injury, the digit that had been injured, the number of arteries that had been repaired, or the use of venous grafts. The rate of survival after replantation of completely amputated parts was 72 per cent (twenty-eight of thirty-nine parts) when the amputation had resulted from a laceration injury and 53 per cent (eighteen of thirty-four parts) when the amputation had resulted from a crush or an avulsion injury. The rate of survival after revascularization of incompletely amputated parts was 100 per cent (all forty-five parts) when the injury had been the result of a laceration and 75 per cent (thirty-three of forty-four parts) when it had been the result of a crush or an avulsion. We did not find any relationship between the age of the patient and the rate of survival of the amputated part after revascularization; however, there was a significantly higher rate of survival (p , 0.02) after replantation in children who were less than nine years old (77 per cent [twenty-four of thirty-one parts]) compared with the rate in those who were nine to sixteen years old (52 per cent [twenty-two of forty-two parts]). The viability of the digit was in jeopardy after twenty-nine (40 per cent) of the seventy-three replantations and nineteen (21 per cent) of the eighty-nine revascularizations. Immediate reoperation resulted in the salvage of only two of the twenty-one replanted parts and six of the twelve revascularized parts that had a reoperation.(ABSTRACT TRUNCATED AT 400 WORDS)

An assessment of the reliability of the Scoliometer.

Accurate noninvasive measurements of spinal curvature are crucial in planning treatment and assessing curve progression in adolescent idiopathic scoliosis. An inter-rater agreement trial and an intra-rater agreement trial were undertaken to estimate the reliability of axial rotation measurement using the Scoliometer (Orthopedic Systems, Inc., Heywood, California). In the Inter-rater trial, two orthopedic surgeon measured the thoracic and lumbar axial rotations of 22 patients with idiopathic scoliosis using the Scoliometer. In the intrarater, trial a single orthopedic surgeon measured the thoracic and lumbar axial rotations of 25 patients on four separate occasions with the Scoliometer. Inter-rater agreement using Scoliometer to estimate the magnitude of the hump (in centimeters) in the thoracic and lumbar regions was poor (intraclass correlation coefficient Rho = 0.57 a nd Rho = 0.76 for thoracic and lumbar regions, respectively). Inter-rater agreement using the Scoliometer to estimate the degree of axial trunk rotation was better (Rho =0.81 and Rho = 0.82 for the thoracic and lumbar regions, respectively). Intra-rater agreement using this device to estimate the magnitude of the hump (in centimeters) in the thoracic and lumbar regions was good (Rho = 0.90 and Rho = 0.84 for the thoracic and lumbar regions, respectively). Intrarater agreement using the Scoliometer to estimate the degreas of curvature was outstanding (Rho = 0.995 and Rho = 0.998 for the thoracic and lumbar regions, respectively). These results indicate that the Scoliometer can be a reliable noninvasive method for respectively assessing spinal axial rotation when used by a single trained observer.

Interleukin-17 synergizes with IFNγ or TNFα to promote inflammatory mediator release and intercellular adhesion molecule-1 (ICAM-1) expression in human intervertebral disc cells

Interleukin‐17 (IL‐17) is a cytokine recently shown to be elevated, along with interferon‐γ (IFNγ) and tumor necrosis factor (TNFα), in degenerated and herniated intervertebral disc (IVD) tissues, suggesting a role for these cytokines in intervertebral disc disease. The objective of our study was to investigate the involvement of IL‐17 and costimulants IFNγ and TNFα in intervertebral disc pathology. Cells were isolated from anulus fibrosus and nucleus pulposus tissues of patients undergoing surgery for intervertebral disc degeneration or scoliosis. The production of inflammatory mediators, nitric oxide (NOx), prostaglandin E2 (PGE2) and interleukin‐6 (IL‐6), as well as intercellular adhesion molecule (ICAM‐1) expression, were quantified for cultured cells following exposure to IL‐17, IFNγ, and TNFα. Intervertebral disc cells exposed to IL‐17, IFNγ, or TNFα showed a remarkable increase in inflammatory mediator release and ICAM‐1 expression (GLM and ANOVA, p < 0.05). Addition of IFNγ or TNFα to IL‐17 demonstrated a synergistic increase in inflammatory mediator release, and a marked increase in ICAM‐1 expression. These findings suggest that IVD cells not only respond with a catabolic phenotype to IL‐17 and costimulants IFNγ and TNFα, but also express surface ligands with consequent potential to recruit additional lymphocytes and immune cells to the IVD microenvironment. IL‐17 may be an important regulator of inflammation in the IVD pathologies.

Expression of Laminin Isoforms, Receptors and Binding Proteins Unique to Nucleus Pulposus Cells of Immature Intervertebral Disc

Intervertebral disc (IVD) disorders are believed to be related to aging-related cell loss and phenotypic changes, as well as biochemical and structural changes in the extracellular matrix of the nucleus pulposus (NP) region. Previously, we found that the laminin gamma1 chain was more highly expressed in immature NP porcine tissues, in parallel with the expression pattern for a laminin receptor, integrin alpha6 subunit, as compared to adjacent anulus fibrosus region. This result suggests that cell-matrix interactions may be unique to the immature NP. However, the identity of laminin isoforms specific to immature or mature NP tissues, their associated receptors, and functional significance are still poorly understood. In this study, we evaluated the zonal-specific expression of the laminin chains, receptors (i.e., integrins), and other binding proteins in immature tissue and isolated cells of rat, porcine and human intervertebral disc. Our goal was to reveal features of cellular environment and cell-matrix interactions in the immature NP. Results from both immunohistochemical staining and flow cytometry analysis found that NP cells expressed higher levels of the laminin alpha5 chain, laminin receptors (integrin alpha3, alpha6, beta4 subunit, and CD239), and related binding proteins (CD151), as compared to cells from adjacent anulus fibrosus. These differences suggest that laminin interactions with NP cells are distinct from that of the anulus fibrosus and that laminins may be important contributors to region-specific IVD biology. The revealed laminin isoforms, their receptors, and related binding proteins may be used as distinguishing features of these immature NP cells in the intervertebral disc.

Bilateral transpedicular decompression and Harrington rod stabilization in the management of severe thoracolumbar burst fractures.

Fifty–eight patients with severe thoracolumbar burst fractures were treated with bilateral transpedicular decompression, Harrington rod instrumentation, and spine fusion. Spinal realignment and stabilization was achieved by contoured dual Harrington distraction rods supplemented by segmental sublaminal wiring. Posterior element fractures were noted in 25 patients, 9 of whom had associated dural tears. Computed tomography was performed to assess the cross–sectional area of the spinal canal before surgery and after decompression. Patients at initial evaluation averaged greater than 67% spinal canal compromise. After surgery, successful decompression was accomplished in 57 patients. One patient required staged, anterior thoracoabdominal decompression and fibula strut grafting. At follow–up (average, 43 months; range, 25–70 months), neurologic improvement was found in 77% of the patients who initially presented with neurologic deficits. Thirty–four of 40 patients with incomplete paraplegia improved one or more subgroups on the Frankel scale. A solid fusion was attained in all 58 patients. No patient had a significant residual kyphotic deformity. Single–stage bilateral transpedicular decompression and dual Harrington rod instrumentation reliably provides decompression of the spinal canal and restores spinal alignment. The procedure allows early mobilization and provides an environment for solid fusion and maximum neurologic return.

Plastic deformation in pediatric fractures: mechanism and treatment

Abstract The plastic deformation often observed in childrens long bone fractures is due largely to the complex nature of the molecular and histologic aspects of pediatric bone. Pediatric cortical bone has a lower mineral content than adult bone, accounting in part for its different material properties. Although plasticity allows childrens long bones to absorb more energy prior to fracture, a significant deformity may persist after injury. An algorithm and technique for treatment of plastic deformation of the radius and ulna, the two most commonly involved bones in plastic deformation, are reviewed.

Possible interaction of genotypes at cystathionine β‐synthase and methylenetetrahydrofolate reductase (MTHFR) in neural tube defects

Neural tube defects are a common, complex disorder with genetic and environmental components to risk. We investigated the previously reported interaction between homozygosity for the thermolabile variant at the methylenetetrahydrofolate reductase and heterozygosity for the 844ins68 allele at the cystathionine β‐synthase loci in cases with lumbosacral myelomeningocele and their parents. Using control allele frequencies from our sample pooled with those published in the literature, we confirm a marginally significant interaction at these two loci. This finding suggests that additional, larger studies are warranted to investigate this possible interaction in more detail.