Using cement plugs in soft tissue infection and osteomyelitis.

Operative foot and ankle osteomyelitis is challenging for orthopedic surgeons because of the area's unique anatomy, high trauma incidence, local and systemic disease effects, and often limited space. Standard treatment includes aggressive operative debridement with local and systemic antibiotic administration to control infection. Dead space management is critical yet technically demanding. The authors report a modified antibiotic cement bead therapy technique in which antibiotic sticks, minnows, and mushroom-shaped plugs are used to strike a balance between the stability of the load-bearing unit and radical removal of infection to preserve a functional foot. Three cases are presented.

Flexor hallucis longus tendon transfer in treatment of Achilles tendinosis.

BACKGROUND: In patients with Achilles tendinosis, Achilles tendon debridement can be supplemented with flexor hallucis longus tendon transfer. Outcomes have not been studied prospectively in older, sedentary, and overweight patients. METHODS: Fifty-eight consecutive limbs in fifty-six consecutive older, sedentary patients with insertional or midsubstance Achilles tendinosis were enrolled prospectively and underwent the procedure. Ten patients were lost to follow-up, leaving forty-eight limbs in forty-six patients available for evaluation after twenty-four months. RESULTS: The forty-six patients who were included in the study had an average age of 54 ± 10 years with an average body mass index of 33.8 ± 6.8 kg/m². Significant improvement was observed between baseline and twenty-four months in terms of the visual analog scale for overall pain intensity (6.7 ± 2.3 versus 0.8 ± 2.0; p < 0.001), the Short Form-36 physical score (34.3 ± 8.0 versus 49.0 ± 9.3; p < 0.001), the Ankle Osteoarthritis Scale pain (54.4 ± 19.2 versus 1.9 ± 2.7; p < 0.001) and dysfunction (62.6 ± 21.4 versus 11.0 ± 24.2; p < 0.001) subscale scores, and performance of a single-leg heel rise (1.9 ± 3.0 versus 7.3 ± 2.7 cm; p < 0.001). Significant improvement compared with baseline was observed at three or six months except in the single-leg heel rise. Improvements in terms of pain and function occurred over twenty-four months, with the most improvement occurring in the first twelve months. At twenty-four months, maximum gastrocnemius circumference was significantly less in the involved compared with the uninvolved leg (40.2 ± 5.1 versus 41.2 ± 4.8 cm; p < 0.001). The mean passive range of motion of the first metatarsophalangeal joint decreased from 85.1° ± 25.3° preoperatively to 68.1° ± 36.7° (a 20% change) at six months (p = 0.03). Most patients reported no hallux weakness (57%; twenty-six of forty-six patients) and no loss of balance due to hallux weakness (76%; thirty-five of forty-six patients). Postoperative peroneal tendinitis was observed in seven patients. Complications included deep-vein thrombosis (two patients), superficial infection or delayed wound-healing (six), scar pain (four), and early disruption of the reconstruction due to a fall (one). CONCLUSIONS: Surgical debridement of the Achilles tendon with flexor hallucis longus tendon transfer was associated with significant improvement in terms of Achilles tendon function, physical function, and pain intensity in a group of relatively inactive, older, overweight patients. When present, hallux weakness had minimal functional sequelae.

Spinal growth modulation with an anterolateral flexible tether in an immature bovine model: disc health and motion preservation.

STUDY DESIGN: An immature bovine model was used to evaluate multilevel anterolateral flexible tethering in a growing spine. OBJECTIVE: To evaluate radiographic, biochemical, histologic, and biomechanical results of tethered spinal growth. SUMMARY OF BACKGROUND DATA: An anterolateral flexible tether has been shown to create a kyphotic and scoliotic spinal deformity in calves. Subsequent disc health and spinal motion has not been analyzed. METHODS: Four consecutive thoracic vertebral bodies (T6-T9) were instrumented anteriorly in 36 1-month-old calves. Seventeen animals (Tether Group) were instrumented with a vertebral staple-two screw construct connected by 2 flexible stainless steel cables. Nineteen animals (Control Group) were instrumented with 1 vertebral body screw with no connecting cable. After a 6-month survival period, the spines were harvest en-bloc and underwent radiographic, computed tomography, biochemical, histologic, and biomechanical analysis. RESULTS: On average, 37.6 degrees +/- 10.6 degrees of coronal and 18.0 degrees +/- 9.9 degrees of sagittal deformity was created in the Tether Group, with significant vertebral wedging toward the tether (P < 0.001). Disc thickness decreased significantly in the Tether Group (P < 0.001), however, disc wedging was not observed. There was no change in gross morphologic disc health or disc water content (P = 0.73). However, proteoglycan synthesis was significantly greater in the tethered discs compared with controls (P < 0.001), and collagen type distribution was different with a trend toward increased type II collagen present on the tethered side of the disc (P = 0.09). Tethers significantly increased spinal stiffness in lateral bending and in flexion/extension (P < 0.05) without affecting torsional stiffness, however, after tether removal range of motion returned to control values. CONCLUSION: Tethering resulted in vertebral wedging while maintaining spinal flexibility. Although changes in proteoglycan synthesis, collagen type distribution, and disc thickness were observed, the tethered discs had similar water content to control discs and did not demonstrate gross morphologic signs of degeneration. Growth modulation is an attractive treatment option for growing patients with scoliosis, avoiding multilevel fusions or brace wear. Strategies for fusionless scoliosis correction should preserve disc health, as adolescent patients will rely on these discs for decades after treatment.

Results of preoperative pulmonary function testing of adolescents with idiopathic scoliosis. A study of six hundred and thirty-one patients.

BACKGROUND: Previous research has suggested a correlation between pulmonary impairment and thoracic spinal deformity. The curve magnitude, number of involved vertebrae, curve location, and decrease in thoracic kyphosis independently contribute to pulmonary impairment, but the strength of these associations has been variable. The objectives of this study were to test the hypothesis that increased thoracic deformity is associated with decreased pulmonary function and to determine which, if any, radiographic measurements of deformity predict pulmonary impairment. METHODS: Preoperative pulmonary function testing and radiographic examination were performed on 631 patients with adolescent idiopathic scoliosis. Correlation analysis and subsequent stepwise multiple regression analysis were carried out to assess the associations between radiographic measurements of deformity and the results of pulmonary function testing. RESULTS: The magnitude of the thoracic curve, the number of vertebrae involved in the thoracic curve, the thoracic hypokyphosis, and coronal imbalance had a minimal but significant effect on pulmonary function. While these four factors were associated with an increased risk of moderate or severe pulmonary impairment, they explained only 19.7%, 18.0%, and 8.8% of the observed variability in forced vital capacity, forced expiratory volume in one second, and total lung capacity, respectively. The degrees of scoliosis that were associated with clinically relevant decreases in pulmonary function were much smaller than previously described, but the majority of the observed variability in pulmonary function was not explained by the radiographic characteristics of the deformity. CONCLUSIONS: Some patients with adolescent idiopathic scoliosis may have clinically relevant pulmonary impairment that is out of proportion with the severity of the scoliosis, and this may alter the decision-making process regarding which fusion technique will produce an acceptable clinical result with the least additional effect on pulmonary function.

Strut allograft union and remodeling using rhBMP-2 in a spinal corpectomy model.

STUDY DESIGN: Growth factor in a collagen sponge carrier was compared to autograft, both packed within an allograft strut following corpectomy in a bovine spinal model. OBJECTIVE: To evaluate incorporation of cortical strut allografts after lumbar corpectomy, comparing augmentation with recombinant human bone morphogenetic protein-2 (rhBMP-2) to local autograft. SUMMARY OF BACKGROUND DATA: Autogenous strut grafts are the gold standard for successful fusion in reconstruction following corpectomy; however, significant donor site morbidity can occur. Recent studies describing consistently successful anterior interbody fusions with BMP augmentation suggest an exciting prospect of unlimited and potent grafting material for these difficult fusions. METHODS: Sixteen calves underwent L3 corpectomy with instrumented strut allograft reconstruction. The rhBMP-2 impregnated collagen sponges filled the empty medullary canal of the allograft in 8 animals. Eight animals had the allograft strut filled with local autogenous bone. After 4 months, the lumbar spines were harvested for radiographic, biomechanical, and histologic evaluation. RESULTS: Computerized tomography revealed allograft fusion in 7 of 8 autograft specimens and 8 of 8 BMP specimens. The BMP treated group had denser bone at the ends of the cortical allograft, but a central void persisted. Autograft filled struts maintained a more uniform distribution of less organized bone throughout the strut canal. Histologic assessment verified remodeling and incorporation of the allografts for both groups. Biomechanical testing confirmed no significant difference in fusion strength between groups. CONCLUSIONS: Large cortical strut allografts (after lumbar corpectomy) supplemented with rhBMP-2 had incorporation and fusion strength comparable to allografts enhanced with cancellous autograft.

Perioperative changes in pulmonary function after anterior scoliosis instrumentation: thoracoscopic versus open approaches.

STUDY DESIGN: A prospective evaluation of pulmonary function in patients with adolescent idiopathic scoliosis undergoing surgical correction. OBJECTIVE: To determine if a minimally invasive thoracoscopic approach had less postoperative pulmonary function impairment compared to open anterior instrumentation for idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Prior studies suggest that open anterior scoliosis surgery causes an initial decrease in pulmonary function that resolves by 2 years after surgery. However, the effect of thoracoscopic instrumented scoliosis correction on pulmonary function is unknown. METHODS: Fifty-four patients with AIS undergoing anterior spinal instrumentation and fusion at the authors' institutions were evaluated with pulmonary function tests assessing forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Patients were evaluated before surgery,as well as 3 months and 1 year after surgery. There were 2 groups of patients: in one group, a thoracoscopic technique was used to visualize and instrument the anterior spine (n = 31); and in the other, an open single or double thoracotomy was used (n = 23). RESULTS: Three months after surgery, the thoracoscopic group had a significantly smaller decline in FVC than the thoracotomy group; at 1 year after surgery, the thoracoscopic group had recovered, while FVC remained reduced in the open group. The decline in FEV1 from before surgery to 3 months after surgery was similar between groups; however, by 1 year after surgery, the thoracoscopic group had more recovery of pulmonary flow than the thoracotomy group. CONCLUSIONS: The thoracoscopic approach causes a smaller decline in pulmonary function 3 months and 1 year after surgery as compared to the more invasive technique of open thoracotomy for anterior spinal instrumentation for correction of adolescent idiopathic scoliosis.

Evaluation of a functional position for lateral radiograph acquisition in adolescent idiopathic scoliosis.

STUDY DESIGN: A retrospective examination of lateral spine radiographs of 50 patients with adolescent idiopathic scoliosis (AIS) was performed to evaluate the sagittal profile of patients in two different standing positions. OBJECTIVES: To evaluate segmental and global changes in the sagittal profile of the spine associated with two standing radiographic positions and determine if one position represents a more functional stance for accurate sagittal balance evaluation. SUMMARY OF BACKGROUND DATA: Studies of spinal sagittal balance during relaxed standing have indicated that the sagittal vertical axis (SVA), as determine by the horizontal displacement of a C7 plumb line from the posterior superior corner of the sacrum, is neutral or slightly positive. However, standing with the arms forward flexed to allow radiographic visualization of the spine results in a negative shift in SVA. METHODS.: Measurements were obtained from standing lateral radiographs in patients with AIS in two different standing positions: arms forward flexed to 45 degrees with elbows fully extended versus elbows fully flexed with fists resting on clavicles. Sagittal plane parameters were analyzed using correlation analyses and repeated-measures analyses of variance with significance set at 0.005. RESULTS: The study cohort included 25 patients who had undergone solely nonoperative treatment (without progression) and 25 patients who had undergone operative intervention for their scoliosis. In all patients, SVA was more negative (C7 shifted more posterior with respect to the sacrum) when the arms were in the forward flexed position compared to the fists on clavicles position (-4.2 +/- 2.5 cm vs. -1.3 +/- 2.4 cm, P < 0.001). In operative patients, the shoulder forward flexed position was associated with relative posterior rotation of the pelvis represented by an average increase of 2.7 +/- 3.8 degrees in pelvic tilt (P = 0.002) and an average decrease of 3.2 +/- 4.5 degrees in sacral slope (P = 0.002). There was no correlation between the degree of arm forward flexion and changes in sagittal measures between the two positions. CONCLUSIONS: The fists on clavicles position for lateral radiograph acquisition has less negative shift in SVA, and in patients with spinal instrumentation, less compensatory posterior rotation of the pelvis. This position is more representative of a patient's functional balance while still allowing adequate lateral radiographic visualization of the spine.

Biomechanical analysis of anterior instrumentation for lumbar corpectomy.

STUDY DESIGN: In vitro biomechanical assessment of spinal stability after corpectomy reconstruction. OBJECTIVES To gain a more thorough understanding of the biomechanical properties of anterior plate versus dual rod systems used for anterior lumbar corpectomy reconstruction. SUMMARY OF BACKGROUND DATA: Vertebral corpectomy is commonly required in the treatment of several types of spinal pathology (fracture, tumor, infection). Stabilization with strut allograft and anterior instrumentation can be accomplished with one of several anterior implant systems. These include plate systems and rod-based systems with theoretically different structural properties. METHODS: Two instrumentation systems, the ATL Z-plate and the Antares system, were each applied to 10 calf lumbar spines with a cortical strut graft reconstructing an L3 corpectomy defect. All spines were tested biomechanically to determine construct stiffness under physiologic loads in multiple planes and then tested in torsion to failure. RESULTS: There was greater stiffness (P < 0.05) in all directions of bending (flexion, extension, lateral bending) for the Antares dual rod construct compared to the Z-plate constructs. No significant difference was noted in either torsional testing under physiologic loads or torque to failure between the groups. CONCLUSIONS: Although there was significantly greater resistance to bending with the dual rod construct, the ultimate selection of a system will require an individual analysis of implant profile, construct demand, and ease of use. Both systems provided secure initial fixation following lumbar corpectomy; however, the Antares system may increase the likelihood of graft incorporation in cases with greater instability and higher load demands.

Factors involved in the decision to perform a selective versus nonselective fusion of Lenke 1B and 1C (King-Moe II) curves in adolescent idiopathic scoliosis.

STUDY DESIGN: A retrospective evaluation of 203 adolescent idiopathic scoliosis patients with Lenke 1B or 1C (King-Moe II) type curves. OBJECTIVES: To evaluate the incidence of inclusion of the lumbar curve in the treatment of this type of deformity as well as radiographic factors associated with lumbar curve fusion. SUMMARY OF BACKGROUND DATA: In patients with structural thoracic curves and compensatory lumbar curves, many authors have recommended fusing only the thoracic curve (selective thoracic fusion). Studies have shown that correction of the thoracic curve results in spontaneous correction of the unfused lumbar curve; however, in some cases, truncal decompensation develops. Though there have been various attempts to define more accurately what type of curve pattern should undergo selective fusion, controversy continues in this area. METHODS: Measurements were obtained from the preoperative standing posteroanterior and side-bending radiographs of 203 patients with Lenke Type 1B or 1C curves from five sites of the DePuy AcroMed Harms Study Group. Patients were divided into two groups depending on their most distal vertebra instrumented: the "selective thoracic fusion" group included patients who were fused to L1 or above and the "nonselective fusion" group included patients fused to L2 or below. A statistical comparison was conducted to identify variables associated with the choice for a nonselective fusion. RESULTS: The incidence of fusion of the lumbar curve ranged from 6% to 33% at the different patient care sites. Factors associated with nonselective fusion included larger preoperative lumbar curve magnitude (42 +/- 10 degrees vs. 37 +/- 7 degrees, P < 0.01), greater displacement of the lumbar apical vertebra from the central sacral vertical line, (3.1 +/- 1.4 cm vs. 2.2 +/- 0.8 cm, P < 0.01), and a smaller thoracic to lumbar curve magnitude ratio (1.31 +/- 0.29 vs. 1.44 +/- 0.30, P = 0.01). CONCLUSIONS: The characteristics of the compensatory "nonstructural" lumbar curve played a significant role in the surgical decision-making process and varied substantially among members of the study group. Side-bending correction of the lumbar curve to <25 degrees (defining these as Lenke 1, nonstructural lumbar curves) was not sufficientcriteria to perform a selective fusion in some of these cases. The substantial variation in the frequency of fusing the lumbar curve (6% to 33%) confirms that controversy remains about when surgeons feel the lumbar curve can be spared in Lenke 1B and 1C curves. Site-specific analysis revealed that the radiographic features significantly associated with a selective fusion varied according to the site at which the patient was treated. The rate of selective fusion was 92% for the 1B type curves compared to 68% for the 1C curves.