Andrew W. Mack

Adjacent vertebral body osteolysis with bone morphogenetic protein use in transforaminal lumbar interbody fusion.

BACKGROUND CONTEXT Recent studies have demonstrated cases of adjacent vertebral body osteolysis when assessing the effect of bone morphogenetic protein (BMP) on fusion rates. However, no study to date has evaluated the course of osteolysis at different periods. PURPOSE To determine the incidence and resolution of osteolysis associated with BMP used in transforaminal lumbar interbody fusions (TLIF). STUDY DESIGN Retrospective review. PATIENT SAMPLE All TLIF cases using BMP performed at one institution with routine postoperative computed tomography (CT) scans at defined intervals. OUTCOME MEASURES Area of osteolysis and fusion as determined by CT scan. METHODS We performed a retrospective analysis of all patients at our facility who underwent TLIF with BMP. Included were all patients who had obtained a CT scan within 48 hours of surgery, 3 to 6 months postoperatively, and 1 to 2 years postoperatively. Areas of osteolysis were defined as lucency within the vertebral body communicating with the interbody spacer that was not present on the immediately postoperative CT scan. Areas of osteolysis were measured in all three planes and the volume used for comparison of the 3 to 6 months CT scans with the greater than 1 year CT scan. RESULTS Twenty-three patients who underwent TLIF with BMP had obtained CT scans at all time periods required for evaluation. Seventy-eight vertebral bodies/end plates were assessed for osteolysis (39 levels). The incidence of osteolysis 3 to 6 months postoperatively in the adjacent vertebral bodies was 54% compared with 41% at 1 to 2 years. The mean volume of osteolysis was at 0.216 cm(3) at 1 to 2 years compared with 0.306 cm(3) at 3 to 6 months (p=.082). The area/rate of osteolysis did not appear to significantly affect the rate of fusion or final outcome with an overall union rate of 83%. CONCLUSIONS The rate of osteolysis decreased at 1 year compared with 3 to 6 months, but only 24% of the vertebral bodies with evidence of osteolysis at 3 to 6 months completely resolved by 1 year.

Microbiology and injury characteristics in severe open tibia fractures from combat.

BACKGROUND: Type III open tibia fractures are common combat injuries. The purpose of the study was to evaluate the effect of injury characteristics and surveillance cultures on outcomes in combat-related severe open tibia fractures. METHODS: We conducted a retrospective study of all combat-related open Gustilo and Anderson (G/A) type III diaphyseal tibia fractures treated at our centers between March 2003 and September 2007. RESULTS: One hundred ninety-two Operation Iraqi Freedom/Operation Enduring Freedom military personnel with 213 type III open tibial shaft fractures were identified. Fifty-seven extremities (27%) developed a deep infection and 47 extremities (22%) ultimately underwent amputation at an average follow-up of 24 months. Orthopedic Trauma Association type C fractures took significantly longer to achieve osseous union (p = 0.02). G/A type III B and III C fractures were more likely to undergo an amputation and took longer to achieve fracture union. Deep infection and osteomyelitis were significantly associated with amputation, revision operation, and prolonged time to union. Surveillance cultures were positive in 64% of extremities and 93% of these cultures isolated gram-negative species. In contrast, infecting organisms were predominantly gram-positive. CONCLUSIONS: Type III open tibia fractures from combat unite in 80.3% of cases at an average of 9.2 months. We recorded a 27% deep infection rate and a 22% amputation rate. The G/A type is associated with development of deep infection, need for amputation, and time to union. Positive surveillance cultures are associated with development of deep infection, osteomyelitis, and ultimate need for amputation. Surveillance cultures were not predictive of the infecting organism if a deep infection subsequently develops. LEVEL OF EVIDENCE: III.

Does the Zone of Injury in Combat-Related Type III Open Tibia Fractures Preclude the Use of Local Soft Tissue Coverage?

Objectives: Does the large zone of injury in high-energy, combat-related open tibia fractures limit the effectiveness of rotational flap coverage? Design: Retrospective consecutive series. Setting: This study was conducted at Brooke Army Medical Center, Walter Reed Army Medical Center, and National Naval Medical Center between March 2003 and September 2007. Patients/Participants: We identified 67 extremities requiring a coverage procedure out of 213 consecutive combat-related Type III open diaphyseal tibia fractures. Intervention: The 67 Type III B tibia fractures were treated with rotational or free flap coverage. Main Outcome Measures: Flap failure, reoperation, infection, amputation, time to union, and visual pain scale. Results: There were no differences between the free and rotational flap cohorts with respect to demographic information, injury characteristics, or treatment before coverage. The reoperation and amputation rates were significantly lower for the rotational coverage group (30% and 9%) compared with the free flap group (64% and 36%; P = 0.05 and P = 0.03, respectively). The coverage failure rate was also lower for the rotational flap cohort (7% versus 27%, P = 0.08). The average time to fracture union for the free flap group was 9.5 months (range, 5-15.8 months) and 10.5 months (range, 3-41 months) for the rotational flap group (P = 0.99). Conclusions: There was a significantly lower amputation and reoperation rate for patients treated with rotational coverage. Contrary to our hypothesis and previous reports, the zone of injury in combat-related open tibia fractures does not preclude the use of local rotational coverage when practicable.

Wound complications following the use of FiberWire in lower-extremity traumatic amputations. A case series.

With the development of new arthroscopic approaches over the last decade, one innovation that has facilitated this trend has been the introduction of high-tensile-strength sutures. These nonabsorbable sutures allow for the reliable and secure fixation of soft tissues, such as the glenoid labrum and rotator cuff, to bone by means of anchors1,2. Similarly, these sutures have gained great acceptance in open procedures, such as tendon repairs and suture fixation of fracture fragments3. FiberWire (Arthrex, Naples, Florida) is one of the first members of this family of sutures. Currently, it is one of the most commonly used high-tensile-strength sutures in orthopaedic surgery. FiberWire is composed of an ultra-high molecular weight polyethylene multifilament core surrounded by a braided polyester jacket4. A silicone coating has been added to the surface of the polyester jacket to improve the handling and knot-tying characteristics of the suture. Ticron (Tyco, Waltham, Massachusetts) is the only other high-tensile-strength suture sold in the United States that has an outer silicone coating. The remaining high-tensile-strength sutures all employ proprietary blends of polyethylene and polyester without the use of a silicone coating. Over a two and a half-year period, we performed or revised 193 lower-extremity amputations at our institution in our treatment of injured soldiers. Because of its strength and the excellent documented clinical experience with FiberWire, we used it to suture the myodesis in 178 (92%) of the 193 transtibial and transfemoral amputations. Recently, five patients with similar-appearing draining sinuses through previously well-healed incisions presented during follow-up visits for the lower-extremity amputations. In all five patients, FiberWire had been used to secure the myodesis. This clustering of similar complications suggested a common cause. Thus, a quality assurance review was initiated. The purpose of this case series is to present the results of …

Biomechanical analysis of occipitocervical stability afforded by three fixation techniques

BACKGROUND CONTEXT Occipital condyle screws appear to be a novel technique that demands biomechanical consideration. It has the potential to achieve fixation anterior to the axis of rotation while offering a point of fixation in line with the C1/C2 screws. PURPOSE To compare the segmental stability and range of motion (ROM) of standard occipitocervical (OC) screw/rod and plate constructs versus a new technique that incorporates occipital condyle fixation. STUDY DESIGN Human cadaveric biomechanical analysis. METHODS After intact analysis, 10 fresh-frozen human cadaveric OC spine specimens were instrumented bilaterally with C1 lateral mass screws and C2 pedicle screws. Additional occipital instrumentation was tested in random order under the following conditions: standard occipitocervical plate/rod system (Vertex Max; Medtronic, Inc., Minneapolis, MN, USA); occipital condyle screws alone; and occipital condyle screws with the addition of an eyelet screw placed into the occiput bilaterally. After nondestructive ROM testing, specimens were evaluated under computed tomography (CT) and underwent destructive forward flexion failure comparing Group 1 to Group 3. RESULTS There was no significant difference in OC (Occiput-C1) axial rotation and flexion/extension ROM between the standard occipitocervical plate/rod system (Group 1) and the occipital condyle screws with one eyelet screw bilaterally (Group 3). Furthermore, the occipital condyle screws alone (Group 2) did allow significantly more flexion/extension compared with Group 1. Interestingly, the two groups with occipital condyle screws (Groups 2 and 3) had significantly less lateral bending compared with Group 1. During CT analysis, the mean occipital condyle width was 10.8 mm (range, 9.1-12.7 mm), and the mean condylar length was 24.3 mm (range, 20.2-28.5). On destructive testing, there was no significant difference in forward flexion failure between Groups 1 and 3. CONCLUSIONS With instrumentation across the mobile OC junction, our results indicate that similar stability can be achieved with occipital condyle screws/eyelet screws compared with the standard occipitocervical plate/rod system.

Contralateral Structural Femoral Autograft Use in Treatment of an Open Periarticular Knee Fracture to Perform Knee Arthrodesis

Combat-related blast injuries often cause devastating extremity trauma. We report a case of a 21-year-old male servicemember who sustained massive bilateral lower extremity trauma secondary to a blast injury. His orthopaedic injuries included a near traumatic disarticulation of the right knee and a left open type IIIB periarticular knee fracture with traumatic patellectomy, loss of the extensor mechanism, and segmental loss of the distal 11 cm of his femur. Definitive treatment of his injuries included a contralateral structural cortical femoral autograft which was implanted into the left knee segmental defect to facilitate knee fusion with an intramedullary knee fusion nail and a right transfemoral amputation. Radiographic evidence of solid fusion was obtained 8 months postoperatively. Currently, the patient is a community ambulator with the aid of his right lower extremity prosthetic limb and cane.