Prospective radiographic and clinical outcomes and complications of single solid rod instrumented anterior spinal fusion in adolescent idiopathic scoliosis.

STUDY DESIGN: Prospective clinical cases series. OBJECTIVES: To prospectively evaluate outcomes and critically review radiographic results and complications associated with single solid rod anterior spinal fusions in adolescent idiopathic scoliosis with 2-year minimum follow-up (range, 2-6 years). METHODS: Ninety consecutive patients at a single institution with thoracic (n = 43) or thoracolumbar/lumbar (n = 47) adolescent idiopathic scoliosis were treated by one of two surgeons with a similar anterior surgical technique using rib autograft, intradiscal structural (Harms) cages placed below T12, and anterior single solid rod convex compressive instrumentation. The patients were evaluated prospectively with the Scoliosis Research Society outcome instrument and upright radiographs before surgery and minimum 2-year follow-up. RESULTS (RADIOGRAPHIC): The average coronal correction of thoracic curves was from 55 degrees to 29 degrees (47%). The average correction of thoracolumbar/lumbar curves was from 50 degrees to 15 degrees (70%). In the sagittal plane, kyphosis was improved in thoracic fusions from 23 degrees to 30 degrees (T5-T12) and lordosis maintained in thoracolumbar/lumbar fusions at -58 degrees (T12-sacrum). Five patients (5.5%) developed a pseudarthrosis, four with implant failure. Three of five required a posterior fusion for a reoperation rate of 3.3%. The fourth and fifth patients were asymptomatic and appeared fused at the 2-year follow-up, with minimal loss of correction. Common risk factors for pseudarthrosis were smoking (4 of 5), weight >70 kg (4 of 5), and for thoracic pseudarthrosis, hyperkyphosis >40 degrees T5-T12 (2 of 3). RESULTS (CLINICAL OUTCOME): Scoliosis Research Society domain average scores were improved for function, pain, and self-image (P < 0.01). With the Scoliosis Research Society satisfaction domain, 88% responded that they were satisfied with their results and 89% would undergo the same treatment again. Four of five patients with pseudarthrosis did not have statistically significant lower final Scoliosis Research Society scores than those with solid fusions (93 vs. 97, P = 0.18). CONCLUSION: Anterior instrumented fusions for adolescent idiopathic scoliosis using a single solid rod had good radiographic and clinical outcomes. Consideration should be given to alternate techniques in larger adolescents (>70 kg) with thoracic hyperkyphosis (>40 degrees ), and smoking should be avoided. Poor radiographic outcomes did not correlate with final Scoliosis Research Society scores.

Spontaneous proximal thoracic curve correction after isolated fusion of the main thoracic curve in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective clinical, radiographic, and patient outcome review of surgically treated adolescent idiopathic scoliosis. OBJECTIVES: To evaluate the spontaneous correction of the noninstrumented proximal thoracic (PT) curve after isolated correction of the main thoracic (MT) curve by either an anterior (ASF) or posterior (PSF) instrumentation and fusion. SUMMARY OF BACKGROUND DATA: There are no studies comparing the structural PT curve response after anterior versus posterior instrumented fusion of the MT curve in adolescent idiopathic scoliosis. METHODS: Eighty-five patients (single surgeon) with adolescent idiopathic scoliosis underwent operative instrumentation and fusion of their MT curve. All patients had a PT curve > or =20 degrees (average 29 degrees, range 20-49 degrees; average residual side-bending 18 degrees, range 3-42 degrees ) and were evaluated for preoperative PT curve flexibility and postoperative curve correction after PSF with the PT curve not instrumented (n = 44) and ASF with the PT curve not instrumented (n = 41). Minimum follow-up was 2 years (average, 3.6 years). Preoperative, 1 week postoperative, and latest follow-up (minimum 2-year) full-length radiographs were evaluated for the PT, MT, and thoracolumbar-lumbar coronal, side-bending, and sagittal Cobb measurements, as well as T1 tilt, clavicle angle, radiographic shoulder height, and the PT, MT, and thoracolumbar-lumbar apical vertical translation. A patient outcome questionnaire was also completed to correlate patient satisfaction with respect to their shoulder balance and overall appearance. RESULTS: The two groups were found to be statistically equivalent (P = 0.66) in terms of preoperative PT curve, MT curve, and MT side-bending curves, with the PT side benders slightly more flexible for the ASF (43%) versus the PSF group (31%) (P = 0.02). RADIOGRAPHIC: The spontaneous improvement in the PT curve was significant (P < 0.0001) in both groups. Additionally, this correction was maintained over time. However, the spontaneous PT curve correction was significantly greater after an ASF versus PSF correction of the MT curve on both the immediate postoperative (P =0.017) and minimum 2-year (P = 0.0024) evaluations, whereas the MT curve correction was the same in both groups (P = 0.45). There was no difference in the postoperative sagittal change in the PT curve (P = 0.12) between the two groups, and there was no difference in radiographic shoulder height (P = 0.5883). PATIENT OUTCOME: Both groups reported improvement in shoulder balance and clinical appearance, but there was no statistical difference between the two groups (P = 0.24). Additionally, no patients reported deterioration in either parameter. CONCLUSIONS: Spontaneous proximal thoracic curve correction consistently occurs after instrumented correction of the main thoracic curve. Furthermore, this spontaneous correction is as good as or slightly better after an ASF versus PSF of the MT curve. The preoperative side bender radiographs (PT curve flexibility) positively correlate with the postoperative spontaneous PT curve correction.

String test measurement to assess the effect of spinal deformity correction on spinal canal length.

STUDY DESIGN: Long cassette coronal and lateral radiographs before and after surgical correction were analyzed and string test measurements made by three observers in 55 surgical cases (13 surgical types). OBJECTIVES: The purpose of the study was to assess the effect of various corrective maneuvers for spinal deformity on the spinal canal length. SUMMARY OF BACKGROUND DATA: When perioperative neurologic deficit occurs, the surgeon removes implants because they are displaced into the spinal canal or the canal has been lengthened. It is important to know the effect certain constructs have on canal length because the ability of the spinal cord to adapt to canal lengthening is variable. METHODS: On the coronal radiographs the concave, convex, midvertebral, and adjusted midvertebral line, and on the sagittal radiographs, the anterior and posterior vertebral body lines were measured. The adjusted coronal line was the assumed path of the spinal cord starting at the midportion of the vertebral body at the top and the bottom of the deformity and then in between, hugging the pedicles as closely as possible while staying inside the pedicles. Adjustments for magnification were made. RESULTS: Anterior compression instrumentation without cages (n = 5) consistently shortened the spinal canal (mean delta -6.67 +/- 2.30 mm, P = 0.003), whereas instrumentation with cages (n = 13) lengthened the canal (mean delta 10.54 +/- 7.58 mm, P = 0.0003). Thoracic curves treated by posterior corrective forces (n = 14) demonstrated lengthening of the canal (mean delta 10.14 +/- 5.23 mm, P = 0.0001), large (n = 5) curves (81-140 degrees, mean delta 13.47 +/- 7.05 mm), and medium (n = 7) curves (50-80 degrees, mean delta 8.43 +/- 3.24 mm). CONCLUSIONS: Many deformity correction maneuvers, although they do not directly include application of posterior or anterior distraction forces, do indirectly lengthen the spinal canal.

Maintaining lumbar lordosis with anterior single solid-rod instrumentation in thoracolumbar and lumbar adolescent idiopathic scoliosis.

STUDY DESIGN: A prospective radiographic evaluation of 20 consecutive patients with primary lumbar or thoracolumbar adolescent idiopathic scoliosis who were treated with anterior convex compressive single solid-rod spinal instrumentation and structural titanium mesh (Harms) cages. OBJECTIVES: To evaluate a lordosis-preserving anterior single solid-rod instrumented fusion technique for these specific adolescent idiopathic curves. SUMMARY OF BACKGROUND DATA: Maintaining instrumented segmental lumbar lordosis after anterior fusion and instrumentation for thoracolumbar and lumbar curves has been difficult. Twenty consecutive patients who underwent anterior single solid-rod fusion, aged 18 or younger with a primary thoracolumbar or lumbar curve, were observed for preservation of lordosis for a minimum of 2 years. METHODS: All patients underwent an identical anterior surgical technique, involving discectomies and anulectomies of all convex discs, structural titanium mesh (Harms) cages placed in the anterior half of all disc spaces below T12, morselized rib autograft packed in all disc spaces to be fused and inside the cages, and anterior single solid-rod (5.0-mm or 5.5-mm diameter) convex compressive spinal instrumentation with appropriate lordotic rod contour and rod rotation as necessary. The anterior rod was placed just posterior to the cages to optimize lordotic contouring of the spine during compression. None of the patients was braced after surgery. The lowest instrumented vertebrae (LIV) were L2 (n = 3), L3 (n = 15), and L4 (n = 2), typically the lower end vertebra of the Cobb measurement. RESULTS: Measurements for the primary coronal Cobb before surgery, 1 week after surgery, and 2 years after surgery were 48 degrees, 11 degrees, and 12 degrees; for C7 plumb line deviation from the midline: 3.6 cm, 1.9 cm, and 1.2 cm; for lowest instrumented vertebra translation: 31 mm, 15 mm, and 15 mm; and for LIV tilt: 29 degrees, 6 degrees and 6 degrees, respectively. Sagittal measurements before surgery, 1 week after surgery, and 2 years after surgery were: T12-L2: -1 degree, -6 degrees, and -6 degrees; T12-LIV: -8 degrees, -13 degrees, -9 degrees; T12-S1: -61 degrees, -56 degrees, -60 degrees; and entire instrumented levels: -6 degrees, -9 degrees, and -6 degrees, respectively. Coronal plane correction improved: 75% in the primary Cobb, 66% in the plumb line, 50% in LIV translation, and 80% in LIV tilt. Sagittal plane alignment improved in T12-L2 lordosis (P < 0.01) with preservation of physiologic lordosis in the instrumented levels, T12-LIV, and T12-sacrum. There were no instrumentation failures, pseudarthroses, or reoperations. CONCLUSIONS: Coronal plane correction with preservation of thoracolumbar and lumbar lordosis 2 years after anterior convex compressive spinal instrumentation was accomplished using a lordotically contoured single solid rod with structural cages placed anteriorly in the disc spaces of patients with primary thoracolumbar or lumbar adolescent idiopathic scoliosis.

The extraneural and intraneural arterial anatomy of the ulnar nerve at the elbow.

The purpose of this report was to investigate the vascular anatomy of the ulnar nerve at the elbow with a technique of combined India ink and latex injection followed by nondissection chemical debridement. Twenty-two fresh human cadaveric arms were injected with India ink to stain the intraneural microcirculation followed immediately by latex injection and chemical debridement for study of the extraneural vascularization. After clearing with a modified Spalteholtz technique, the intraneural blood supply was studied in 10 of the specimens. The findings demonstrated a consistent but segmental extraneural and intraneural vascular supply from the superior ulnar collateral, inferior ulnar collateral, and posterior ulnar recurrent arteries. No identifiable direct anastomosis was seen between the superior ulnar collateral and posterior ulnar recurrent arteries in 20 of 22 arms. The inferior ulnar collateral artery provided the only direct vascularization to the nerve in the region just proximal to the cubital tunnel. Although the clinical importance of maintaining specific arterial sources to the ulnar nerve has not been determined, these anatomic findings indicate that the arterial contribution from the inferior ulnar collateral artery may be more important than appreciated previously.

The extraosseous and intraosseous arterial anatomy of the adult elbow.

UNLABELLED: We investigated the extraosseous and intraosseous arterial anatomy of the human adult elbow. Twenty-two fresh adult cadaveric upper extremities were studied with a technique of combined India-ink and latex injection followed by chemical débridement. The intraosseous vascularity of twelve extremities was then evaluated with a rapid Spalteholz clearing technique. Our findings demonstrated consistent patterns of extraosseous and intraosseous vascular anatomy, which were organized into three vascular arcades: medial, lateral, and posterior. The medial arcade was formed by the superior and inferior ulnar collateral arteries and the posterior ulnar recurrent artery. The lateral arcade was formed by the radial and middle collateral, radial recurrent, and interosseous recurrent arteries. The posterior arcade was formed by the medial and lateral arcades and the middle collateral artery. The intraosseous circulation of the elbow, which was segmental in organization, appeared to be dependent on the local blood supply. The capitellum and the lateral aspect of the trochlea were supplied by posterior perforating vessels arising from the radial recurrent, radial collateral, and interosseous recurrent arteries. The medial aspect of the trochlea was supplied by a circumferential vascular ring originating from the inferior ulnar collateral artery. Watershed areas were apparent between the blood supplies to the medial and lateral aspects of the distal end of the humerus. The olecranon was richly supplied by vessels coursing along its medial aspect from the posterior ulnar recurrent artery and along its lateral aspect from the interosseous recurrent artery. The radial head had a dual extraosseous blood supply from a single branch of the radial recurrent artery, which supplied the head directly, and from additional vessels from both the radial and the interosseous recurrent artery, which penetrated the capsular insertion at the neck of the radius. CLINICAL RELEVANCE: Our findings demonstrate that arterial contributions to the intraosseous circulation of the elbow are more specific than previously appreciated. The intraosseous circulation of the elbow is derived mainly from perforating vessels that arise from neighboring extraosseous arteries. These perforating arteries may be damaged by trauma or by extensile dissection during reconstruction of the elbow. An understanding of the extraosseous and intraosseous circulation of the elbow may help to avoid iatrogenic injury to the intraosseous circulation.

Arthrometric results of arthroscopically assisted anterior cruciate ligament reconstruction using autograft patellar tendon substitution.

Sixty-two patients who underwent arthroscopically assisted anterior cruciate ligament reconstruction with the middle-third patellar tendon autograft without extraarticular augmentation were retrospectively reviewed at a minimum 2-year (mean, 37-month) followup. A postoperative KT-1000 arthrometric evaluation revealed a mean maximum manual difference of 0.3 mm (range, -6 to +16). Ninety percent of the patients had a mean maximum difference of < or = 3 mm. Three patients had a > or = 5 mm mean maximum difference; positive pivot shifts were noted in two of these patients. Despite an early range of motion, early weightbearing protocol without an extraarticular backup, the pivot shift (92% negative) was reliably eliminated at postoperative followup. Arthrometric parameters were statistically reduced (P < 0.0001) from preoperative status and were consistent with the diagnostic criteria established for normal knees. There was no relationship established in the "tighter" knees (those with negative side-to-side arthrometric differences) and the incidence of knee flexion contractures, patellar pain symptoms, Cybex extension deficit (> 20%), functional indices, or postoperative rating scales.

Arthroscopy-assisted anterior cruciate ligament reconstruction using patellar tendon substitution. Two- to four-year follow-up results.

The purpose of this retrospective study was to evaluate clinically, functionally, and objectively our initial experience using free, autogenous middle third patellar tendon for anterior cruciate ligament reconstruction without extraarticular augmentation in 62 of 75 patients (80% followup) who were available for clinical review at a minimum 2-year followup. Subjective, clinical, functional, Cybex dynamometer, and KT-1000 arthrometer tests were performed along with modified tests of the Hospital for Special Surgery, Noyes Cincinnati, Tegner, and Lysholm knee rating scales. Ninety-two percent had a negative pivot shift at followup. The mean Cybex dynamometer extension deficits postoperatively were 9% and 7% at 180 and 240 deg/sec. Mild patellar pain symptoms were noted in 18%. The reoperation rate was 10% with a mild flexion contracture as the most common reason. The Hospital for Special Surgery scoring scale postoperatively was 88; Noyes, 86; Lysholm, 88; and Tegner, 6. Mean postoperative single-legged and vertical jump indices were 88% and 87%, respectively. The KT-1000 arthrometric evaluation postoperatively revealed a mean maximum manual difference of 0.3 mm; 92% of the patients had a maximum manual difference of < or = 3 mm. Subjectively, 95% indicated that they would undergo the procedure again. Early results demonstrate excellent stability, preservation of motion, and encouraging evaluations by scoring scales and arthrometric evaluation.