Use of polyetheretherketone spacer and recombinant human bone morphogenetic protein-2 in the cervical spine: a radiographic analysis.

BACKGROUND CONTEXT: Results recently reported in the literature have raised some concerns regarding the use of recombinant human bone morphogenetic protein (rhBMP-2) in the cervical spine. PURPOSE: We undertook a radiological and clinical review of cervical fusions performed at our institution with polyetheretherketone (PEEK) interbody cage and rhBMP-2. STUDY DESIGN: Observational study. PATIENT SAMPLE: Perioperative clinical and radiologic data of all patients who underwent an anterior cervical discectomy and fusion using PEEK and rhBMP-2 for cervical spondylotic radiculopathy or myelopathy were collected. OUTCOME MEASURES: Images were examined for fusion, heterotopic ossification, end-plate resorption, subsidence, and segmental sagittal alignment. METHODS: All patients underwent detailed postoperative radiologic analysis using a computed tomography (CT) scan obtained at least 6 months postoperatively and plain X-rays obtained at regular intervals. RESULTS: Twenty-two patients had 38 levels fused using PEEK and varying doses of rhBMP-2. No anterior cervical swelling requiring additional procedures or longer than anticipated hospital stays occurred. Pseudoarthrosis, shown as a horizontal radiolucent fissure through the midportion of the PEEK cage on CT, occurred in four patients. Excessive bone growth into the spinal canal or foramina occurred in 26 (68%) patients but did not result in neurologic sequelae. Cystic regions in the core of the PEEK spacer were seen in most patients, with 15 levels (39%) having cysts measuring 3mm or greater. Moderate or severe osteolysis of the end plates occurred in 57% of levels, and this led to subsidence of the construct and loss of some of the segmental sagittal alignment (ie, lordosis) that had been achieved with surgery. CONCLUSIONS: The unlimited supply of PEEK spacers and rhBMP-2 and their ease of use make them attractive platforms to achieve fusion. This study has demonstrated that the fusion process using rhBMP-2 is a dynamic one, with osteolysis dominating the initial phase, leading to end-plate resorption and consequently loss of some of the disc space height and sagittal alignment that was achieved with surgery. There is a high incidence of bone growth beyond the core of the PEEK spacer and cystic regions within the cage. Given our experience, we currently reserve the use of PEEK and rhBMP-2 for use in those patients who are at greatest risk of pseudoarthrosis.

Lumbar curve response to selective thoracic fusion in adult idiopathic scoliosis.

BACKGROUND CONTEXT: To date, no study has critically examined the radiographic characteristics of the lumbar curve after selective thoracic fusion for the adult idiopathic scoliosis patient population. PURPOSE: To evaluate the radiographic response of the lumbar curve to selective thoracic fusion in the adult scoliosis population with correlative clinical outcomes. STUDY DESIGN: Retrospective case series. PATIENT SAMPLE: Thirty patients with idiopathic scoliosis surgically treated at a mean age of 40 years (range, 20-66) using a posterior translational technique. OUTCOME MEASURES: Radiographic review and functional outcome assessment. METHODS: A retrospective, minimum 2-year follow-up, radiographic, and clinical review. All patients underwent selective thoracic posterior fusion with end-instrumented vertebra at T11 (1), T12 (7), L1 (14), and L2 (8). RESULTS: At a mean follow-up of 39 (range, 24-87) months, spontaneous lumbar curve Cobb improvement (36 degrees -18 degrees = 50% correction) was less than the bending radiograph (12 degrees , 68% correction). Lowest-instrumented vertebra (LIV) tilt angle improved from 24 to 9 degrees and LIV disc angle improved from 8 to 4 degrees (p < .001). Lumbar apical disc angle improved from 10 to 7 degrees (p < .001). Lumbar apical vertebral translation remained unchanged from pre-op (17 mm) to latest follow-up (17 mm) (p = .23). Lumbar curve rotation increased from 8 to 10 degrees (p = .11). One patient had coronal imbalance of greater than 3 cm and two patients had greater than 3 cm of negative sagittal imbalance. Mean subgroup scores of the Scoliosis Research Society-22 questionnaire improved (p < .01) for pain (3.0-3.8) and self-image (2.5-4.0) but remained the same for function and mental health. Only one patient required extension of fusion to include the lumbar curve 6 years postoperatively. CONCLUSIONS: The lumbar curve response in adult, selective thoracic scoliosis surgery is characterized by 1) moderate correction but less than the bending film Cobb; 2) greater change in LIV tilt and disc angle than apical vertebra disc angle; 3) no change in lumbar apical translation or rotation; 4) more significant disc height preservation at the LIV compared with lumbar apex. Good clinical outcomes can be achieved with posterior translational instrumentation in adult scoliosis patients.

Management of adolescent idiopathic scoliosis.

This article outlines several critical areas in the contemporary evaluation and treatment of the adolescent patient who has idiopathic scoliosis. Highlights of the physical examination combined with key radiographic measurements provide a framework for the algorithm of operative versus nonoperative treatment. The basics of the Lenke classification system are presented in a step-by-step outline, and the surgical treatment options based on this classification are summarized. This article provides a core knowledge base to facilitate a more thorough comprehension of adolescent scoliosis and allow readers to understand emerging publications more readily.

A novel source of cancellous autograft for ACDF surgery: the manubrium.

There are a variety of techniques and biologic options when performing interbody fusion during an anterior cervical discectomy and fusion (ACDF). Autologous graft provides high rates of fusion; however, complications associated with donor site morbidity from the iliac crest have prompted some surgeons to use alternative graft material. Ten patients (8 men, 2 women) with cervical radiculopathy underwent single-level ACDF with plate fixation, titanium mesh cage, and cancellous autograft from the manubrium. Cancellous bone was obtained through a cortical window on the anterior aspect of the manubrium through a 2-cm transverse incision. A minimum 1-year clinical and radiographic follow-up for all patients evaluated fusion rates, donor site morbidity, and patient satisfaction. All patients had immediate postoperative resolution of radicular symptoms and radiographic evidence of solid fusion within 3 months. No patient complained of donor site pain and narcotic pain medication was not required after discharge. No complications associated with the manubrium donor site were noted; however, 1 female patient was dissatisfied with its cosmetic appearance. The manubrium is an effective, safe, and technically facile source of autologous bone graft that yields high fusion rates and patient satisfaction in contemporary ACDF surgery. This new technique to obtain cancellous graft from the manubrium combines the advantages of autologous bone without the morbidity of iliac crest harvest.

Comparison of pelvic fixation techniques in neuromuscular spinal deformity correction: Galveston rod versus iliac and lumbosacral screws.

STUDY DESIGN: Retrospective radiographic and clinical review. OBJECTIVE: To evaluate the safety and efficacy of iliac screws as a method of pelvic fixation in neuromuscular spinal deformity correction using the Galveston rod technique as a comparison group. SUMMARY OF BACKGROUND DATA: Sacropelvic fixation in patients with neuromuscular spinal deformity has traditionally used Galveston rods placed into the iliac wing. Difficulties with radiographic halos around the rods (loosening), rod contouring, and attaching to lumbar spine anchors have prompted their replacement with iliac screws. METHODS: A minimum 2-year radiographic and clinical follow-up compared 20 patients with the Galveston technique to 20 patients with an iliac screw undergoing posterior spinal fusion (T2/T3-pelvis) for neuromuscular spinal deformity. All patients with the Galveston technique had sublaminar wires for their lumbar anchors, while the majority of patients with an iliac screw technique had at least 2 lumbar and/or sacral screws placed in addition to the iliac screws. RESULTS: There were no significant differences between the 2 groups in preoperative, postoperative, and latest follow-up (mean 3.1 years) measurements for coronal Cobb measures, coronal and sagittal C7 plumblines, and T1 offset. Pelvic obliquity was similar in both groups preoperatively (22 degrees) but at latest follow-up was statistically improved in the patients with an iliac screw (4.4 degrees) versus those with the Galveston technique (7.3 degrees) (P = 0.04). There were 13 patients with the Galveston technique versus 6 with an iliac screw who had radiolucent halos more than 2 mm around the pelvic anchor devices at latest follow-up (P < 0.05). The Galveston technique group had 4 broken rods and 2 reoperations, while the iliac screw group had 1 broken screw and no reoperations. CONCLUSIONS: Using iliac screws for pelvic fixation in neuromuscular spinal deformity affords equivalent maintenance of pelvic obliquity and scoliosis correction compared to the Galveston technique. Furthermore, the iliac screw technique avoids complex, lumbosacral 3-dimensional rod bends and yields minimal implant complications.

Selective posterior thoracic fusions for adolescent idiopathic scoliosis: comparison of hooks versus pedicle screws.

STUDY DESIGN: A retrospective review of adolescent idiopathic scoliosis (AIS) patients with major thoracic-compensatory lumbar C modifier curves treated with a selective posterior fusion using an all-hook construct versus pedicle screw construct. OBJECTIVES: To compare the clinical and radiographic results of selective posterior thoracic fusion using hooks versus pedicle screws in patients with major thoracic-compensatory lumbar C modifier AIS curves. SUMMARY OF BACKGROUND DATA: Although spontaneous lumbar curve correction often occurs following a selective thoracic spinal fusion, there are few reports that focus on selective posterior thoracic spinal fusion in the presence of a lumbar C modifier curve. METHODS: Sixty-six consecutive patients with major thoracic-compensatory lumbar C modifier AIS curves underwent selective posterior thoracic fusion to T12 or L1 at a single institution (1987-2001). Hooks were used for instrumentation in 32 patients and pedicle screws were used in 34 patients. Patients were evaluated at a minimum 2-year follow-up. To test for differences between groups analysis of covariance (ANCOVA) was used. RESULTS: There was no statistical difference between the preoperative thoracic and lumbar Cobb values for the hook group versus the pedicle screw group. The amount of correction obtained surgically of the thoracic Cobb and the amount of spontaneous lumbar Cobb correction were significantly greater in the pedicle screw group (P < 0.001). The incidence of postoperative coronal decompensation, with a greater than 20 mm shift to the left of the C7 plumbline, was higher in the hook group (13 patients) as compared with the pedicle screw Group 4 patients (P < 0.005). There were no complications or reoperations in either group. CONCLUSION: Selective thoracic fusion of main thoracic-compensatory lumbar C modifier AIS curves with pedicle screws allowed for better thoracic correction and less postoperative coronal decompensation than seen with hooks.

Acetabular and femoral radiographic abnormalities associated with labral tears.

UNLABELLED: The purpose of our study was to define the incidence of acetabular and femoral osseous abnormalities associated with symptomatic acetabular labral tears. We reviewed the radiographs of 78 patients treated arthroscopically for labral tears and 22 patients with asymptomatic hips for comparison. Overall, 49% of patients with labral tears had at least one radiographic abnormality (17% acetabular, 14% femoral, and 18% both). Hip dysplasia was more prevalent in patients with labral tears (36%) compared with control subjects (0%). A decreased head-neck offset was present in 18% of patients with labral tears versus 5% of the control subjects. An anterolateral prominence at the femoral head-neck junction, creating an aspherical femoral head, was present in 29% of patients with labral tears. Sixty-one percent of those patients also met criteria for dysplasia and/or decreased head-neck offset. A retroverted acetabulum was present in 12% of patients with labral tears and none of the control subjects. Osteoarthritis was more common in patients with labral tears (33%) than in control subjects (9%). Because acetabular and femoral osseous abnormalities commonly are associated with labral tears, recognition of these abnormalities is important to optimize surgical treatment of patients with symptomatic labral disease. LEVEL OF EVIDENCE: Diagnostic study, Level II (development of diagnostic criteria on consecutive patients-with universally applied reference "gold" standard). See the Guidelines for Authors for a complete description of levels of evidence.

Magnetic resonance arthrography versus arthroscopy in the evaluation of articular hip pathology.

In this study, we compared magnetic resonance arthrography results with hip arthroscopy findings to assess the diagnostic value of this imaging technique in evaluating acetabular labral tears and concurrent articular hip pathology. One hundred one consecutive patients (102 hips) with a clinical diagnosis of acetabular labral tear were assessed using magnetic resonance arthrography and had hip arthroscopy after failing to improve with nonoperative treatment. Magnetic resonance arthrography detected 71 of 93 (76%) acetabular labral tears (92 patients) with five false positive studies in five patients (4.9%). Articular cartilage findings diagnosed by magnetic resonance arthrography were confirmed by arthroscopy in 64 hips in 64 patients (62.7%). With respect to labral pathology, magnetic resonance arthrography showed a sensitivity of 71%, specificity of 44% positive predictive value of 93%, negative predictive value of 13%, and accuracy of 69%. With respect to articular cartilage pathology, magnetic resonance arthrography had a sensitivity of 47%, specificity of 89%, positive predictive value of 84%, negative predictive value of 59%, and accuracy of 67%. Although magnetic resonance arthrography is an excellent positive predictor in diagnosing acetabular labral tears and articular cartilage abnormalities, it has limited sensitivity. A negative imaging study does not exclude important intra-articular pathology that can be identified and treated arthroscopically.