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Regis W Haid

Publications and source records attributed to Regis W Haid.

30 records · Page 2Linked to original sources
PubMed2002

The Cervical Spine Study Group anterior cervical plate nomenclature.

The authors review historical and biomechanical aspects of anterior cervical plate (ACP) systems. They propose a novel classification system for ACPs based on the biomechanical and graft-loading properties of these systems. A retrospective review of the literature comprising both clinical and laboratory investigations regarding the ACP system was undertaken. Comparison of each system is considered in the context of the biomechanical attributes and graft-loading properties of each type of plate. Salient characteristics reviewed include restriction of screw backout, screw-angle variability, and mobility at the screw-plate interface. A new classification system for ACPs is proposed that primarily considers the ability of the construct to restrict screw backout, as well as the properties of the plate-screw interface--that is, the capacity for rotational or translational movement. A new classification system is presented that provides unified, biomechanically descriptive nomenclature. Using this nomenclature, the ACP devices currently available and those developed in the future can be uniformly categorized.

Biomechanical Phenomena↗
PubMed2002

Atlantal lateral mass screws for posterior spinal reconstruction: technical note and case series.

OBJECT: A variety of techniques may be used to achieve fixation of the upper cervical spine. Transarticular atlantoaxial screws, posterior interspinous cable and graft constructs, and interlaminar clamps have been used effectively to achieve atlantoaxial fixation. Various anatomical factors, however, may preclude the successful application of these techniques. These factors include aberrant vertebral artery anatomy, irreducible atlantoaxial subluxation, exaggerated cervicothoracic kyphosis, and the absence of the osseous substrate for fixation. In these cases, an alternative method of fixation must be performed. The authors present an alternative method to achieve fixation of the atlas in which lateral mass screws can be applied to atlantoaxial and occipitocervical fixation. METHODS: Between February 1998 and November 2001, eight patients who ranged in age from 16 to 74 years underwent posterior fixation for upper cervical instability. Diagnoses included C-2 metastastic disease in two patients, irreducible odontoid fractures in two patients, atlantoaxial subluxation in two patients, and transverse ligament synovial cyst in two patients. Various anatomical factors precluded transarticular atlantoaxial screw fixation in seven patients. One patient with a highly unstable spine due to a C-2 metastasis and pathological fracture underwent occipitocervical fusion. Atlantocervical fixation was achieved in seven patients by using varying constructs incorporating C-1 lateral mass screws. Occipitocervical fixation was achieved in one patient by incorporating C-1 lateral mass screws as an additional fixation point. A total of 14 C-1 lateral mass screws were placed in eight patients. There were no intraoperative complications. In all patients rigid fixation was achieved as demonstrated on postoperative radiographs. One patient died on postoperative Day 9 of aspiration pneumonia. At a mean follow-up time of 7.4 months, rigid fixation was maintained in all patients. CONCLUSIONS: Atlantal lateral mass screws can be used to provide a safe and efficacious means of achieving atlantoaxial fixation when anatomical constraints preclude the use of a more traditional procedure. Atlantal lateral mass screws may also be incorporated in occipitocervical constructs to provide additional fixation points which may prevent construct failure.

Adolescent↗
PubMed2002

Posterior cervical fixation using a new polyaxial screw and rod system: technique and surgical results.

OBJECT: Standard lateral mass plate and screw systems are of limited use in patients with abnormal cervical anatomy and do not easily allow for extension to either the occipit or the thoracic spine. The objective of this study was to demonstrate the safety, surgical efficacy, and advantages of a new cervical polyaxial screw and rod system for posterior occipitocervicothoracic arthrodesis. METHODS: The authors reviewed a multicenter series of patients who underwent surgery in which they used a new posterior cervical polyaxial screw and rod system. The system was implanted in 32 (20 women and 12 men) adult patients (mean age 56.9 years, range 23-84 years). Twenty-three of the patients were treated for spondylostenosis; four for cervical fracture/dislocations; four for kyphosis; and one patient was treated for pseudarthrosis that developed after prior surgery. The system was successfully implanted in all patients despite the presence of anatomical lateral mass anomalies in the majority of cases. The mean number of levels fused was 3.9 (range one-eight levels). This dynamic system allowed for screw placement into the occiput, C-1 lateral masses, C-2 pars, C3-7 lateral masses, and low cervical as well as upper thoracic pedicles. Selective application of compressive or distractive forces was possible in adjacent segments. Surgery-related complications included one dural tear and one malpositioned screw. There were two cases of wound infection. CONCLUSIONS: Unlike standard lateral mass plate and screw systems, the new cervical polyaxial screw and rod system easily accommodates severe degenerative cervical spondylosis and curvatures. This instrumentation system allows for polyaxial screw placement with subsequent multiplanar rod contouring and offset attachment. The authors have used this system successfully, and without significant complications, to achieve posterior cervical arthrodesis.

Adult↗
PubMed2002

Anterior cervical plating enhances arthrodesis after discectomy and fusion with cortical allograft.

OBJECTIVE: Anterior plate fixation has gained widespread acceptance for the treatment of cervical spondylosis, theoretically enhancing the rate of arthrodesis. There are few studies comparing fusion rates after anterior cervical discectomy and fusion (ACDF) with and without a plate. The purpose of this study was to evaluate the efficacy of anterior cervical plating for fusion enhancement after one- and two-level ACDF with cortical allograft. METHODS: A retrospective review was performed with 251 patients who underwent one- or two-level ACDF with cortical allograft and plate stabilization between 1993 and 1999. An independent surgeon reviewer determined fusion status and complications. A successful fusion was defined by the absence of lucency around the graft, evidence of bridging bone between the endplate and the graft, and the absence of movement on dynamic imaging scans. Follow-up data, ranging from 9 months to 3.6 years, were available for 233 patients. A control group of 289 patients who underwent ACDF without plating was described in a previously published report by the senior author (RWH). Therefore, a total of 540 patients were evaluated for determination of the efficacy of anterior cervical plating with cortical allograft bone. Statistical significance was determined by chi(2) test. RESULTS: The fusion rates for one- and two-level ACDF with anterior fixation were 96 and 91%, respectively, compared with 90 and 72% for one- and two-level ACDF without anterior fixation. The observed increases in fusion rates for both one- and two-level procedures proved to be statistically significant (P < 0.05). There were no recorded infectious, neurological, or graft-related complications among the cohort treated with anterior cervical plating. Compared with the results for the cohort treated without anterior cervical plates, there was a statistically significant decrease in the graft-related complication rate with the application of plates (P < 0.001). Two patients who received plates were noted to have adjacent-segment degenerative changes that required surgical intervention. No hardware fractures were noted; however, one patient was noted to have a single displaced screw, without clinical consequences. CONCLUSION: The use of anterior cervical plating after one- and two-level ACDF with allograft cortical bone significantly enhanced arthrodesis. The improved fusion rate and negligible complication rate associated with anterior cervical plating are compelling factors justifying its use in the treatment of cervical spondylosis.

Adult↗
PubMed2002

Comparison of the mini-open versus laparoscopic approach for anterior lumbar interbody fusion: a retrospective review.

OBJECTIVE: The anterior lumbar interbody fusion (ALIF) procedure has become an accepted fusion technique for treating patients with degenerative disorders of the lumbar spine. Many consider laparoscopic ALIF to be the least invasive approach. A modification of the open laparotomy--the "mini-open" approach--is an attractive alternative. In this retrospective review, a comparison of these two ALIF approaches is presented. METHODS: We conducted a retrospective review of 98 patients who underwent ALIF procedures between 1996 and 2001 in which either a mini-open or a laparoscopic approach was used. Patient demographics, intraoperative parameters, length of hospitalization, and technique-related complications associated with the use of these two approaches were compared. The subset of patients who underwent L5-S1 ALIF procedures was analyzed separately. Statistical analysis was conducted with chi2 and Student's paired t tests. RESULTS: Between 1996 and 2001, a total of 98 patients underwent ALIF. A laparoscopic approach was used in 47 of these patients, and the mini-open technique was used in the other 51 patients. Operative preparation and procedure time were longer with the use of a laparoscopic approach, and significantly greater during L5-S1 ALIF procedures (P < 0.05). A marginal but significant increase in length of stay was observed after mini-open ALIF procedures (P < 0.05). The immediate postoperative complication rate was greater after mini-open ALIF procedures, 17.6 versus 4.3% (P < 0.05); however, the rate of retrograde ejaculation was higher in the laparoscopic group, 45 versus 6% (P < 0.05). CONCLUSION: Both the laparoscopic and mini-open techniques are effective approaches to use when performing ALIF procedures. On the basis of the data obtained in this retrospective review, the laparoscopic approach does not seem to have a definitive advantage over the mini-open exposure, particularly in an L5-S1 ALIF procedure. In our opinion, the mini-open approach possesses a number of theoretical advantages; however, the individual surgeon's preference ultimately is likely to be the dictating factor.

Adult↗
PubMed2002

Allograft implants for posterior lumbar interbody fusion: results comparing cylindrical dowels and impacted wedges.

OBJECTIVE: With the proliferation of implant types available for use in posterior lumbar interbody fusion (PLIF) procedures, the choices for surgeons have become increasingly complex. The goal of this study was to retrospectively review a series of 49 patients who underwent PLIF with the use of allograft cylindrical threaded cortical bone dowels (TCBDs) and allograft impacted wedges. Nerve root injury rates, fusion rates, and clinical outcomes of the allograft impacted wedge group are compared with those in the allograft cylindrical TCBD group. METHODS: We performed a retrospective chart and radiographic review of 49 patients. Twenty-seven patients underwent PLIF with impacted allograft wedges, and 22 patients underwent PLIF with allograft cylindrical TCBD. Permanent nerve root injury rates, fusion rates, and clinical outcomes were assessed on the basis of a minimum of 1 year of follow-up data in this nonconsecutive series. RESULTS: Permanent nerve root injuries in the impacted wedge and TCBD groups were documented with physical examinations conducted pre- and postoperatively. The cylindrical TCBD group showed a 13.6% rate of permanent nerve root injury, and the impacted wedge group demonstrated a 0% rate, and these rates were statistically significant (analysis of variance, P = 0.049). The fusion rate at a mean of 13.9 months of follow-up was 95.4% in patients in whom the cylindrical TCBD was implanted and 88.9% after a mean of 17.4 months of follow-up in patients in whom impacted wedges were used. The fusion rate difference between the TCBD and impacted wedge groups was not significant. The satisfactory outcome rate was 72.7% for the TCBD group and 85.1% for the impacted wedge group, and the impacted wedge group was found to have a significantly higher rate of satisfactory outcomes (P = 0.016, analysis of variance). Analysis of the patient outcomes in the TCBD and impacted wedge groups according to sex, mean length of follow-up, workman's compensation claim rate, and smoking habit yielded no significant difference. CONCLUSION: With a minimum of 1 year of follow-up in this nonconsecutive series of 49 patients, a comparison of the use of allograft TCBD versus allograft impacted wedges in PLIF procedures reveals a statistically significant increase in permanent nerve root injury rates with the use of cylindrical TCBD implants as compared with impacted allograft wedges. There is no difference between the two groups in terms of fusion rates, and clinical outcomes with the use of impacted wedges were significantly better.

Adolescent↗
PubMed2002

Cervical spinal stenosis: outcome after anterior corpectomy, allograft reconstruction, and instrumentation.

OBJECT: The authors undertook a retrospective single-institution review of 261 patients who underwent anterior cervical corpectomy, reconstruction with allograft fibula, and placement of an anterior plating system for the treatment of cervical spinal stenosis to assess fusion rates and procedure-related complications. METHODS: Between October 1989 and June 1995, 261 patients with cervical stenosis underwent cervical corpectomy, allograft fibular bone fusion, and placement of instrumentation for spondylosis (197 patients), postlaminectomy kyphosis (27 patients), acute fracture (25 patients), or ossification of the posterior longitudinal ligament (12 patients). All patients suffered neck pain and cervical myelopathy or radiculopathy refractory to medical management. Of the procedures, 133 involved a single vertebral level (two disc levels and one vertebral body), 96 involved two levels, 31 involved three levels, and a single patient underwent a four-level procedure. Clinical and radiographic outcomes were assessed postoperatively and at 6-month intervals. The mean follow-up period was 25.7 months (range 24-47 months). Successful fusion was documented in 226 patients (86.6%). A stable, fibrous union developed in 33 asymptomatic patients (12.6%), whereas an unstable pseudarthrosis in two patients (0.8%) required reoperation. There were no cases of infection, spinal fluid leakage, or postoperative hematoma. Complications included transient unilateral upper-extremity weakness (two patients), dysphagia (35 transient and seven permanent), and hoarseness (35 transient and two permanent). In 14 patients (5.4%) radiological studies demonstrated evidence of hardware failure. CONCLUSIONS: Cervical corpectomy with fibular allograft reconstruction and anterior plating is an effective means of achieving spinal decompression and stabilization in cases of anterior cervical disease. Symptomatic improvement was achieved in 99.2% of patients. In their series the authors found a fusion rate of 86.6% and rates of permanent hoarseness of 3.4%, dysphagia of 0.7%, and an instrumentation failure rate of 5.4%.

Adolescent↗
PubMed2002

Effect of spinal disease on successful arthrodesis in lumbar pedicle screw fixation.

OBJECT: Pedicle screw fixation with transverse process fusion has gained widespread acceptance since its inception. Improved rates of arthrodesis have been demonstrated when this technique is used. The authors present one of the largest series of patients to undergo this procedure at a single center; one of the goals was to correlate construct length and spinal disease with rates of successful arthrodesis by conducting a prospective analysis of lumbar fusion in which pedicle screws were placed. METHODS: During a 7-year period, the senior author performed pedicle screw fixation with posterolateral fusion in 457 patients; the mean follow-up period was 28.4 months. Indications for fusion included metastatic tumor, single-level degenerative disc disease (DDD), trauma, degenerative scoliosis, and translational vertebral instability. Successful fusion was based on the radiographic demonstration of a bilateral contiguous osseous bridge over the transverse processes and absence of movement on dynamic x-ray films. Fusion rates were lowest in cases of tumors (54%) and highest in cases of trauma (96%). In patients with single-level DDD the rate was 91%, and in those with translational instability it was 89%. Fusion rates, however, declined steeply in relation to each additional motion segment in the translational instability group. In this group a strong linear trend for proportion was demonstrated (p < 0.001). The overall fusion rate in patients with degenerative scoliosis was 70%. The overall fusion rate for the entire group was 86%. CONCLUSIONS: The data in this study can be used as a benchmark with which to compare newer technologies. Although overall pedicle screw-assisted fusion rate in cases of trauma or selected degenerative lesions approached 90%, the arthrodesis rates are not uniform for the different diagnoses. This appears to be related to the underlying spinal disease and the number of segments included in the fusion.

Adolescent↗
PubMed2002

Applications of a resorbable interbody spacer in posterior lumbar interbody fusion.

Polyhydroxy acids are a promising class of resorbable materials with potential applications in spinal surgery. One such polymer, MacroPore (MacroPore Biosurgery, Inc.), offers a balance of strength, predictable degradation, lack of stimulus of foreign body reaction, and biocompatibility with neural tissue. MacroPore can be formed into an array of shapes and can be manufactured, sterilized, and stored using conventional techniques. Limited clinical experience has been gained with resorbable implants used as load-sharing devices in a posterior lumbar interbody fusion construct.

Absorbable Implants↗
PubMed2002

Applications of a resorbable interbody spacer via a posterior lumbar interbody fusion technique.

Polyhydroxyacids are a promising class of bioresorbable materials withpotential applications in spinal surgery. One such polymer, MacroPore (MacroPore Biosurgery Inc, San Diego, Calif), offers a balance of strength, predictable degradation, lack of stimulus of foreign body reaction, and biocompatibility with neural tissue. MacroPore can be formed into an array of shapes and can be manufactured, sterilized, and stored with conventional techniques. Limited clinical experience has been gained with bioresorbable implants that are used as load-sharing devices in a posterior lumbar interbody fusion construct.

Absorbable Implants↗
PubMedDate not supplied

Posterior lumbar interbody fusion using recombinant human bone morphogenetic protein type 2 with cylindrical interbody cages.

BACKGROUND CONTEXT: In a large series of human patients undergoing open anterior lumbar interbody fusion with a tapered titanium fusion cage, recombinant human bone morphogenetic protein type 2 (rhBMP-2) on an absorbable collagen sponge carrier has been shown to decrease operative time and blood loss, to promote osteoinduction and fusion and to be a safe and effective substitute for iliac crest harvesting. PURPOSE: The purpose of the study was to determine the clinical and radiographic outcomes in patients treated for single-level degenerative lumbar disc disease with a posterior interbody fusion, using stand-alone cylindrical threaded titanium fusion cages with either autogenous bone graft or rhBMP-2 and an absorbable collagen sponge carrier. STUDY DESIGN/SETTING: A prospective, randomized, nonblinded, 2-year pilot study at 14 investigational sites. PATIENT SAMPLE: Between March 1999 and December 1999, 67 patients with symptomatic, single-level degenerative lumbar disc disease of at least 6 months' duration underwent a single-level posterior lumbar interbody fusion using two paired cylindrical threaded titanium fusion devices. Patients were randomly assigned to one of two groups: one (n=34 patients) received rhBMP-2 on a collagen sponge carrier; the other (n=33 patients) autogenous iliac crest bone graft. OUTCOME MEASURES: Clinical outcomes were measured using low back and leg pain numerical rating scales, the Short Form (SF)-36, Oswestry Low Back Pain Disability Questionnaire and work status. Plain radiographs and computed tomographic scans were used to evaluate fusion at 6, 12 and 24 months after surgery. METHODS: In this prospective nonblinded study, 67 patients were randomly assigned to one of two groups who underwent interbody fusion using two cylindrical threaded fusion cages: the investigational group (34 patients), who received rhBMP-2 on an absorbable collagen sponge, and a control group (33 patients), who received autogenous iliac crest bone graft. Clinical data were collected and analyzed by a commercial entity. RESULTS: The mean operative time and blood loss for the investigational rhBMP-2 group was 2.6 hours and 322.8 ml, respectively. For the autograft control group, these values were 3.0 hours and 372.7 ml. The differences were not significant. Although not statistically different, at 24 months, the investigational group's fusion rate of 92.3% was higher than the control's at 77.8%. At all postoperative intervals, the mean Oswestry, back and leg pain scores and physical components of the SF-36 improved in both treatment groups compared with preoperative scores, but no significant differences were found between groups. A statistically significant difference in the change in back pain was found at 24 months for the investigational group. In the control group, two adverse events related to harvesting of the iliac crest graft occurred in two patients (6.1%). CONCLUSIONS: This small multicenter, randomized, nonblinded trial showed few statistically significant differences between the study groups. Both groups showed comparable improvements on outcome scores. Overall results show that the use of rhBMP-2 can eliminate the need for harvesting iliac crest graft and may be an equivalent replacement for autograft for use in successful posterior lumbar interbody fusions. Further studies of the use of rhBMP-2 in posterior lumbar interbody fusion cage procedures are needed.

Adult↗