Faculty Bibliography

STUDY DESIGN: A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial. OBJECTIVE: To evaluate the safety and effectiveness of the ProDisc-L (Synthes Spine, West Chester, PA) lumbar total disc replacement compared to circumferential spinal fusion for the treatment of discogenic pain at 1 vertebral level between L3 and S1. SUMMARY OF BACKGROUND DATA: As part of the Investigational Device Exemption clinical trial, favorable single center results of lumbar total disc replacement with the ProDisc-L have been reported previously. METHODS: Two hundred eighty-six (286) patients were treated on protocol. Patients were evaluated before and after surgery, at 6 weeks, 3, 6, 12, 18, and 24 months. Evaluation at each visit included patient self-assessments, physical and neurologic examinations, and radiographic evaluation. RESULTS: Safety of ProDisc-L implantation was demonstrated with 0% major complications. At 24 months, 91.8% of investigational and 84.5% of control patients reported improvement in the Oswestry Low Back Pain Disability Questionnaire (Oswestry Disability Index [ODI]) from preoperative levels, and 77.2% of investigational and 64.8% of control patients met the > or =15% Oswestry Disability Index improvement criteria. Overall neurologic success in the investigational group was superior to the control group (91.2% investigational and 81.4% control; P = 0.0341). At 6 weeks and 3 months follow-up time points, the ProDisc-L patients recorded SF-36 Health Survey scores significantly higher than the control group (P = 0.018, P = 0.0036, respectively). The visual analog scale pain assessment showed statistically significant improvement from preoperative levels regardless of treatment (P < 0.0001). Visual analog scale patient satisfaction at 24 months showed a statistically significant difference favoring investigational patients over the control group (P = 0.015). Radiographic range of motion was maintained within a normal functional range in 93.7% of investigational patients and averaged 7.7 degrees. CONCLUSIONS: ProDisc-L has been found to be safe and efficacious. In properly chosen patients, ProDisc-L has been shown to be superior to circumferential fusion by multiple clinical criteria

Surgical repair of recurrent postmyocardial infarction septal defect is associated with a high mortality rate. We present 2 patients whose recurrent defects were closed percutaneously using an Amplatzer device

Toe flexor force (hallux and second toe) was determined in the right and left feet of 24 dancers and 29 non-dancers (sitting and standing positions) using a commercially-available pressure sensor connected to a voltmeter. For the hallux and second toe combined (all trials combined), average toe flexor force was slightly greater for dancers than non-dancers (dancers, 7 +/- 4 N; non-dancers, 6 +/- 4 N; P<0.049). For dancers and non-dancers combined (all trials), the average toe flexor force of the hallux was more than twice that of the second toe (hallux, 9 +/- 4 N; 2nd toe, 4 +/- 1 N; P<0.0001); average toe flexor force was slightly greater in standing than sitting positions (standing, 7 +/- 4 N; sitting, 6 +/- 3 N; P<0.0001); and the average toe flexor force was slightly greater for the right than left foot (right, 7 +/- 4 N; left, 6 +/- 4 N; P<0.012). The average toe flexor force was greatest for the first repetition and slightly decreased for the second and third repetitions (first repetition, 7 +/- 4 N; second and third repetitions each, 6 +/- 4 N; P<0.0013). Toe flexor force measurement may potentially be applicable to clinical practice as a guide to rehabilitation after injury or as a screening parameter for readiness to advance dance or other athletic training, performance, or competition

An intraarticular, dorsal, proximal epiphyseal stress fracture (Salter-Harris III) of the first metatarsal was identified in a 14-year-old boy. Successful fracture healing was achieved with a rocker sole shoe modification and activity limitation.

Injury to the anterior cruciate ligament removes the major stabilizing structure to anterior tibial translation. The initial trauma may lead to meniscal and cartilage damage, predisposing the knee to early degenerative changes. Moreover, a knee with an isolated ACL rupture may have recurrent episodes of instability that can lead to a similar degenerative course. At this time, one cannot accurately predict which patients will tolerate ACL deficiency, and which patients will not. Current long-term studies support a progressive worsening condition in the ACL and meniscal deficient knees. Physical therapy together with lifestyle modifications may be necessary. Those unwilling to make these types of changes or those with associated injuries may benefit from ACL reconstruction

STUDY DESIGN: Records of 111 patients randomly selected from a population who received an interbody fusion cage during a clinical Investigation Device Exemption trial (BAK/L) yielded 126 operative levels and were retrospectively assessed. OBJECTIVES: This study examined lumbar spine sagittal alignment and clinical outcomes before and 2 years after fusion surgery. SUMMARY OF BACKGROUND DATA: Lumbar lordosis is important in spinal sagittal alignment and balance, especially the L4-S1 area. Perceived consensus is that anatomically correct lumbar lordosis is desired and that a loss of lumbar lordosis may lead to spine pathology. There is little information on lumbar lordosis after interbody fusion. METHODS: A random sample of 111 patients who received a cylindrical cage implant (total pool of 947 patients) yielded 126 operative lumbar segments. There were 52 posterior approaches and 59 anterior approaches, and all cages were placed in the L4-L5 or L5-S1 levels. Preoperative and 2-year follow-up lateral radiographs were measured for segmental lordosis. Cage position was measured relative to the posterior longitudinal ligament. Segmental lordotic change was correlated to clinical outcome at the 2-year follow-up. RESULTS: Preoperative lordosis was different as a function of surgical approach. There was a significant 2-year decrease in lordosis with the posterior approach group; however, all intervertebral angles were within typical ranges. Clinical outcomes were significantly improved 2 years postsurgery. There was no correlation between changes in lordosis and clinical outcomes. CONCLUSIONS: Interbody lumbar fusion with a threaded cylindrical cage does not appear to have any clinically relevant effects on segmental lordosis, which is maintained within anatomically normal levels. Clinical outcome measures show significant postsurgery improvement, and changes in lordotic angles are not predictive of clinical outcome

HYPOTHESIS: Similar to familial tumors, sporadic head and neck paragangliomas are associated with chromosomal deletions at either 11q13 or 11q22-23. BACKGROUND: Familial paragangliomas are inherited in an autosomal dominant pattern with genomic imprinting of the maternal allele. Genetic studies of familial paragangliomas have localized the causative genetic defect to two separate loci: 11q13.1 and 11q22-23. The molecular pathogenesis of sporadic head and neck paragangliomas has not been studied. METHODS: Blood and tumor samples from patients with sporadic head and neck paragangliomas were screened for deletions on chromosome 11 using DNA microsatellite markers and polymerase chain reaction. Polymerase chain reaction-amplified alleles from tumor specimens were compared with those from the blood of eight patients. A greater than 50% reduction in band intensity (as determined by densitometric analysis) between blood and tumor sample was indicative of a chromosomal deletion. RESULTS: Three of the eight patients were found to have deletions at chromosome 11q: two at chromosome 11q22-23 and one at 11q13. CONCLUSIONS: Sporadic head and neck paragangliomas are associated with deletions at chromosome 11q13 and 11q22-23. It is thus likely that sporadic and familial paragangliomas share a similar molecular pathogenesis.

The changes that occur in the body as part of the normal aging process and the degenerative changes that often accompany them predispose the elderly to various orthopedic problems. Age, general health, and functional level are all important factors in determining the optimum management of these patients. Treatments are aimed at restoring patient independence and activity to preinjury levels, while at the same time minimizing the risks of treatment complications

BACKGROUND: Ventricular pressure and volume overload may induce hemodynamically important ventricular interactions mediated by the thick interventricular septum. The purpose of this study was to determine whether analogous hemodynamically manifest atrial interactions occur across the thinner interatrial septum. METHODS: Right atrial (RA) and left atrial (LA) pressures were measured with micromanometer-tipped catheters before and after atrial pressure and volume overload elicited by sequential right ventricular (RV), RA, and septal ischemia induced in nine open-chest dogs. RESULTS: Following RV ischemia, RA pressure increased and RA contraction and relaxation were enhanced, as indicated by an augmented A wave and X descent. Despite decreased LV diastolic size, LA pressure increased, with similar increases in its A wave and X descent. RA ischemia depressed RA contraction and relaxation, resulting in diminished A wave and X descent. Parallel changes occurred in the LA waveform. Following septal ischemia, LA contraction and relaxation were enhanced, as reflected in an augmented A wave and X descent. Despite persistent RA ischemia, the RA A wave and X descent increased. CONCLUSIONS: These findings demonstrate interatrial transmission of pressure and waveform changes that may influence hemodynamic evaluation and cardiac function.