Management of Osteochondral Lesions of the Talus

Management strategies for symptomatic osteochondral lesions of the talus are primarily surgical. Treatment options for symptomatic osteochondral lesions of the talus most commonly include bone marrow stimulation techniques, osteochondral autograft transplantation, osteochondral allograft transplantation, autologous chondrocyte implantation, matrix-induced autologous chondrocyte implantation, and particulated juvenile articular cartilage. The selection of the most appropriate treatment option should be based on the specifics of a talar lesion, in particular, lesion size.

Lisfranc Injuries in the Elite Athlete

The management of sports-related Lisfranc injuries is optimized by a detailed understanding of the relevant anatomy, mechanisms of injury, clinical diagnostic maneuvers, imaging, and treatment options for patients with this disabling injury. A lower energy ligamentous variant Lisfranc injury, which was first observed in professional football players, has recently been described. The treatment options for patients with a Lisfranc injury include nonsurgical management, open reduction and internal fixation, suture-button fixation techniques, and arthrodesis.

Challenges and Controversies of Foot and Ankle Trauma

Traumatic injury to the foot and ankle can result in long-term disability, which may have substantial negative implications on a patient's functional outcomes and quality of life. The diagnosis and appropriate management of these challenging injuries are not always agreed on or straightforward. In particular, the appropriate diagnosis and management of distal tibiofibular syndesmotic injuries as well as the surgical approach and role of primary subtalar arthrodesis for intra-articular calcaneal fractures are controversial.

High-Risk Stress Fractures in Elite Athletes

Surgeons should understand common factors that predispose high-level athletes to stress injuries as well as the importance of vitamin D and specifics related to vascular supply, location of injury, biomechanics, and susceptibility factors in high-level athletes who have stress injuries. Surgeons should be aware of diagnostic- and management-based recommendations for and the outcomes of anterior tibia, medial malleolus, tarsal navicular, and proximal fifth metatarsal stress fractures in professional athletes.

Lateral Ankle Instability and Peroneal Tendon Pathology

Surgeons should understand the anatomic, vascular, biomechanical, and predisposing factors related to lateral ankle instability and peroneal tendon injuries, including peroneal tendinitis and tenosynovitis, peroneal tendon tears and ruptures, as well as peroneal tendon subluxation and dislocation. Surgeons should understand the treatment options and recommendations for patients who have lateral ankle instability and peroneal tendon injuries from the perspective of a sports medicine foot and ankle specialist. In addition, surgeons should be aware of arthroscopic approaches and an algorithm for the treatment of patients who have lateral ankle instability and peroneal tendon injuries.

Achilles Tendon Rupture in Elite Athletes

The management of acute Achilles tendon rupture in elite athletes is a current area of clinical controversy. Recent studies have reported near-equivocal outcomes in patients who undergo either nonsurgical or surgical treatment of Achilles tendon rupture; however, similar functional outcomes may not be observed in elite athletes who are at the highest levels of athletic performance and undergo nonsurgical or surgical treatment of Achilles tendon rupture. Surgeons should understand the risks and benefits of nonsurgical and surgical management of acute Achilles tendon rupture. Surgeons also should understand the accelerated rehabilitation protocols; functional nonsurgical and postoperative rehabilitation protocols; as well as the standard open, percutaneous, and minimally invasive surgical techniques for the management of Achilles tendon rupture from the perspective of a sports medicine foot and ankle specialist.

Radiographic Outcomes of Lisfranc Injuries Treated with a Suture Button Device

Category:

Trauma

Introduction/Purpose:

Disagreement exists as to the optimal treatment of Lisfranc injuries of the midfoot. Some authors suggest that primary arthrodesis should be the treatment of choice, whereas others are proponents of open reduction and internal fixation (ORIF). There has been increased interest in using a suture button device in lieu of traditional screw fixation, which in general must be removed. Biomechanical studies comparing screw fixation with suture button devices have had conflicting results. The aim of this study was evaluate patients with Lisfranc injuries treated with a suture button radiographically over time.

Methods:

43 patients with a Lisfranc injury treated surgically with a suture button device (Tightrope, Arthrex, Naples, FL) by two fellowship-trained orthopaedic foot and ankle surgeons were identified via a database query for the CPT code 28615 (open treatment of tarsometatarsal joint dislocation). The distances between the first and second metatarsal (M1-M2) and between the medial cuneiform and the second metatarsal (C1-M2) were measured on anterior-posterior (AP) radiographs using standardized, readily-identifiable landmarks. All measurements were performed independently by two musculoskeletal radiologists and were averaged. Accuracy of reduction was assessed by comparing measurements on weightbearing AP radiographs of the uninjured foot with the operatively-treated foot at 6 weeks postoperatively, also weightbearing. Maintenance of reduction over time was assessed by comparing measurements at 6 weeks postoperatively with measurements taken at the time of last follow-up. Measurements were also compared between the injured foot preoperatively and at time of last follow-up. T-tests using SPSS software were performed for statistical analysis in comparing the means of the different measurements.

Results:

Average radiographic follow-up was 35.8 weeks (6.1-178.9). Accuracy of reduction was less than 1 mm for both the M1- M2 and C1-M2 measurements when comparing the uninjured foot with the surgically-treated foot at 6 weeks postoperatively; this difference was significant in the C1-M2 measurement (difference = 0.77 mm, p=0.032), but not in the M1-M2 measurement (difference = 0.44 mm, p=0.190). There was no significant difference in measurements between 6 weeks postoperatively and at final follow-up (difference in M1-M2=0.22 mm, p=0.435; difference in C1-M2=0.27 mm, p=0.352). There was significant improvement in the measured distances of the injured foot preoperatively to that measured at final follow-up in the C1-M2 measurements (difference in C1-M2=-0.82mm, p=0.021), while the difference in the M1-M2 measurements approached significance (difference in M1-M2= -0.56 mm, p=0.067).

Conclusion:

To our knowledge, this is the first and largest series assessing radiographic outcomes of Lisfranc injuries in patients treated surgically with a suture button device. After open reduction of Lisfranc injuries, the suture-button device used in this study appears to adequately maintain this reduction over time while patients are weightbearing and back to full activity. We therefore conclude that based on our results, the suture button appears to present an effective alternative to traditional screw fixation for treatment of Lisfranc injuries.

BMP induced inflammation: a comparison of rhBMP-7 and rhBMP-2

Concern has been raised because of reports of inflammatory swelling following the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human bone morphogenetic protein-7 (rhBMP-7). The purpose of this study is to compare the inflammatory action of rhBMP-7 with those of rhBMP-2. ELISA assays (IL-6, TNF-α) were used to measure the cytokine response to different concentrations of rhBMP-7 and -2. Recombinant human BMP-7 was absorbed into absorbable collagen sponges and different amounts were implanted either subcutaneously (SC) or intramuscularly (IM) into the backs of rats. Using MRI and MIPAV software, we measured the degree of soft tissue edema at 3 h and at 2, 4, and 7 days postoperatively. After sacrificing rats on day 7 the inflammatory zone and mass were measured and the tissue examined histologically. Soft tissue edema after rhBMP-7 and rhBMP-2 implantation was dose-dependent and peaked at 3 h for the subcutaneous implants and at 2 days for the intramuscular implants. RhBMP-7 was associated with a significantly smaller soft tissue edema volume than was rhBMP-2 only at the highest dose (20 µg/ml). Both rhBMP-2 and rhBMP-7 triggered dose-dependent inflammatory reactions. Compared to rhBMP-2, rhBMP-7 is associated with somewhat smaller soft tissue edema volumes. Although rhBMP-7 is associated with an inflammatory reaction leading to soft tissue edema, at high doses this response is significantly less than that seen with rhBMP-2. Our animal model can be used to test materials that could ameliorate this reaction.

Kinematic Evaluation of Association between Disc Bulge Migration, Lumbar Segmental Mobility, and Disc Degeneration in the Lumbar Spine Using Positional Magnetic Resonance Imaging

Degenerative disc disease and disc bulge in the lumbar spine are common sources of lower back pain. Little is known regarding disc bulge migration and lumbar segmental mobility as the lumbar spine moves from flexion to extension. In this study, 329 symptomatic (low back pain with or without neurological symptoms) patients with an average age of 43.5 years with varying degrees of disc degeneration were examined to characterize the kinematics of the lumbar intervertebral discs through flexion, neutral, and extension weight-bearing positions. In this population, disc bulge migration associated with dynamic motion of the lumbar spine significantly increased with increased grade of disk degeneration. Although no obvious trends relating the migration of disc bulge and angular segmental mobility were seen, translational segmental mobility tended to increase with disc bulge migration in all of the degenerative disc states. It appears that many factors, both static (intervertebral disc degeneration or disc height) and dynamic (lumbar segmental mobility), affect the mechanisms of lumbar disc bulge migration.

Effects of the bone morphogenetic protein binding protein spp24 (secreted phosphoprotein 24 kD) on the growth of human lung cancer cells

Bone morphogenetic proteins (BMPs) and transforming growth factor-beta (TGF-β) contribute to the growth of some skeletal metastases through autocrine stimulation. Secreted phosphoprotein 24 kDa (spp24) has been shown to bind to both BMP-2 and TGF-β and to markedly inhibit the osteogenic properties of rhBMP-2. We hypothesized that the addition of spp24 would sequester autocrine growth factors (especially BMP-2) and reduce tumor growth in a system (A549 human non-small cell lung cancer cell line) where autocrine stimulation by BMP-2 is known to be important. A549 cells were injected into two sites (subcutaneous and intraosseus) in SCID mice with and without the co-injection of BMP-2 and spp24. Tumor growth after 8 weeks was assessed through gross examination, radiological imaging, and histological analysis. Spp24 attenuated the tumor growth enhancing effects of rhBMP-2 and reduced the tumor growth when added to tumor cells that were not treated with BMP-2. We conclude that spp24 can reduce A549 cell tumor growth in both soft tissue and intraosseus environments. We hypothesize that the mechanism for this inhibition is interruption of autocrine stimulation through the sequestration of BMP-2. Spp24 can be developed into a therapeutic agent that can be employed in clinical situations where the inhibitions of BMPs and related proteins is advantageous.

Bone morphogenetic protein-binding peptide reduces the inflammatory response to recombinant human bone morphogenetic protein-2 and recombinant human bone morphogenetic protein-7 in a rodent model of soft-tissue inflammation

BACKGROUND CONTEXT

Bone morphogenetic protein (BMP)-2 and BMP-7 are used to enhance bone formation in spine surgery, but the use of these materials is associated with side effects including inflammation, especially in the soft tissues of the neck. Bone morphogenetic protein-binding peptide (BBP) binds BMP-2 and BMP-7 and imparts a "slow-release" property to collagen carrier.

PURPOSE

To test the hypothesis that the addition of BBP will reduce the soft-tissue inflammation induced by the implantation of BMP-2 and BMP-7 on a collagen sponge.

STUDY DESIGN/SETTING

Prospective in vivo rodent model of inflammation.

METHODS

We implanted six different materials absorbed onto collagen sponges: absorbable collagen sponge (ACS) alone; BBP alone; recombinant human bone morphogenetic protein (rhBMP)-2 alone; rhBMP-2 plus BBP; rhBMP-7 alone; and rhBMP-7 plus BBP. Sponges were implanted bilaterally (subcutaneously [SC] and intramuscularly [IM]) into the backs of rats. Using magnetic resonance imaging, inflammation was assessed in terms of soft-tissue edema volume at 3 hours and at 2, 4, and 7 days. The animal subjects were killed on Day 7, and the dimensions of the inflammatory mass were measured manually in the case of SC tissue and those of the inflammatory zone were determined subsequently by microscopic examination in the case of muscle.

RESULTS

Both the SC and the IM soft-tissue edema volumes in the rhBMP-2 plus BBP and the rhBMP-7 plus BBP groups were significantly lower than those observed in the rhBMP-2 alone and rhBMP-7 alone groups. The edema volume associated with BBP alone was greater than that associated with ACS alone but less than that associated with the other treatment groups. The measurements of inflammatory masses and zone yielded similar results.

CONCLUSIONS

Bone morphogenetic protein-binding peptide may reduce the inflammatory response associated with the use of rhBMP-2 and rhBMP-7 in a rodent model of inflammation and in a form that has previously been shown to enhance the activity of BMPs. These preliminary studies suggest that BBP may have the potential to be used in the future to improve healing and reduce soft-tissue swelling in surgical applications of BMPs.

The effect of needle size inducing degeneration in the rat caudal disc: evaluation using radiograph, magnetic resonance imaging, histology, and immunohistochemistry

BACKGROUND CONTEXT

The rat caudal disc has been increasingly used in studying of disc degeneration because of its simplicity, low cost, and efficiency. However, the reproducibility and standardization are essential to facilitate the investigations of biologic therapeutics at different stages of degeneration.

PURPOSE

To identify the effect of different needle gauges to the degenerative response in rat caudal discs and to examine its pathogenesis by looking at the cellular and matrix changes.

STUDY DESIGN

In vivo study of injury-induced rat caudal disc degeneration using needle puncture.

PATIENT SAMPLE

Thirty-six Lewis rats aged 12-14 weeks.

OUTCOME MEASURES

The induced degenerative discs were analyzed by plain radiograph, magnetic resonance imaging (MRI) and histological examination. Proteoglycan content was assessed by alcian blue stain. Immunohistochemistry using aggrecan, collagen II, and Sox-9 was also evaluated to investigate cell differentiation and matrix changes.

METHODS

All rats were divided into three groups according to different needle gauges (18G, 20G, and 22G). Caudal discs were punctured percutaneously under image guidance. Radiographs and MRI were obtained at 2 weeks interval until 8 weeks. At each time point, three rats from each group were sacrificed for histological analysis and immunohistochemistry.

RESULTS

Larger needle gauges, especially 18G, produced more deterioration of the disc when compared with smaller sizes, particularly with time. Significant differences were identified in almost all parameters compared between 18G and 22G at the 8-week time point. For the effect of time in the same needle size, the differences occurred between 2- or 4-week and 8-week time point in the 18G and 20G groups. The proteoglycan and aggrecan stain gradually decreased over time. Chondrogenic differentiation was identified within the degenerative disc by detecting Sox-9 positive cells and collagen II accumulation increased as degeneration progressed.

CONCLUSIONS

The puncture-induced degenerative changes in rat caudal discs can imitate the human degenerative cascade as observed in plain radiograph, MRI, histology, and immunohistochemistry. We suggest that needle size affects the occurrence of progression of degeneration; thus, the large needle size was required to accelerate the deterioration. The size of needle and time point after injury should be considered when investigating the effect of therapeutic materials to retard degeneration or regenerate the intervertebral disc.

Magnetic resonance imaging grading of interspinous ligament degeneration of the lumbar spine and its relation to aging, spinal degeneration, and segmental motion

OBJECT

Degenerative changes of the interspinous ligaments (ISLs) have generally been ignored in previous studies. Factor-related causes, the effects that these changes have on other structures within the spinal functional unit, and their relation to kinematic changes in the spine are lacking. In this study, the authors evaluated the reliability of a proposed MR imaging grading system of ISL degeneration (ISLD). They also investigated the relationship between ISLD and aging, disc/facet joint degeneration, and lumbar segmental motion.

METHODS

The authors studied 256 lumbar motion segments from L-2 to S-1 in 64 patients (35 men and 29 women) with a mean age of 46.08 years (range 23–85 years). An MR imaging–based grading system for ISLD was developed and ranged from Grade A (mild) to Grade D (severe). The reliability was tested, and the correlation of the grade with the severity of the disc and facet joint degeneration was examined. The segmental motion of each functional unit was measured using flexion/extension MR imaging, and their relationships with ISL grades were identified.

RESULTS

Grade A was observed in 115 levels (44.9%), Grade B in 105 (41.0%), Grade C in 15 (5.9%), and Grade D in 21 levels (8.2%). The kappa coefficients for intraobserver and interobserver agreements were substantial to excellent (intraobserver [0.871] and interobserver [0.721–0.807]). Grade D was observed primarily in elderly patients. Segmental motion tended to decrease in the most severe grade, with a significant difference in angular mobility. As the severity of ISLD increased, the severity of disc/facet joint degeneration increased (p < 0.001 and p < 0.05, respectively).

CONCLUSIONS

The authors proposed a reliable and reproducible grading system that may be used to investigate spinal kinematics in association with ISLD. The authors' findings illustrated the distribution of ISLD grades. The most severe grade occurred primarily in elderly patients. Mobility decreased in the most severe grade; therefore, the stage of ISLD should be taken into consideration when evaluating spinal stability.

The relationship between degree of facet tropism and amount of dynamic disc bulge in lumbar spine of patients symptomatic for low back pain

Facet tropism has been investigated as a predisposing factor for degenerative changes in the lumbar spine; however, no prior study has evaluated the relationship between disc bulge and facet tropism. In this study, we used kinetic magnetic resonance imaging (kMRI) to investigate the association between degree of facet tropism and amount of disc bulge in the lumbar spine in relation to age. kMRIs in the flexion, neutral, and extension positions were performed on 410 consecutive patients with low back pain. T2-weighted midsagittal and axial mid-disc cuts were analyzed to measure disc bulge and facet angle. Facet asymmetry was calculated and classified as: no facet tropism, <6°; mild facet tropism, 6–11°; or severe facet tropism, ≥11°. Maximal static bulge (MSB), maximal dynamic bulge (MDB), and age in the facet tropism groups were compared by age subpopulations and MDB categories, defined by the positions between which the largest change in disc bulge occurs. We found the severe facet tropism group to be associated with a nearly significant increase in MSB and MDB over the no facet tropism group in the older subpopulation at the L4–L5 level only, and a larger MDB in the L4–L5 MDB category [E–N], where the greatest change in disc bulge occurs between neutral and extension positions (p = 0.013). Our findings suggest that severe facet tropism is associated with increased disc bulge at L4–L5 in only a subset of older age patients, but may in large part be due to biomechanical factors that define the [E–N] category.

MRI classification of interspinous ligament degeneration of the lumbar spine: intraobserver and interobserver reliability and the frequency of disagreement

Posterior spinal ligament pathology is becoming increasingly recognized as a significant cause of low back pain. Despite the growing clinical importance of interspinous ligament degeneration in low back pain patients, formal reliability studies for the magnetic resonance imaging (MRI) evaluation of interspinous ligaments have not been performed. We proposed an MRI classification system for interspinous ligament degeneration and conducted a comprehensive reliability and reproducibility assessment. Fifty patients who had low back pain with or without leg discomfort (26 males and 24 females) with a mean age of 48.8 years (range 23-85 years) were studied. The classification for lumbar interspinous ligament degeneration was developed on the basis of the literature using mid-sagittal T1- and T2-weighted images. Three spine surgeons independently graded a total of 200 interspinous ligament levels. Intraobserver and interobserver reliability were assessed by kappa statistics. The frequency of disagreement was also identified. The intraobserver agreement was excellent in all readers (kappa range 0.840-0.901). The interobserver agreement was lower as expected, and was substantial to excellent (kappa range 0.726-0.818). Overall complete agreement was obtained in 87.8% of all interspinous ligament levels. A difference of 1, 2, and 3 grades occurred in 8.1, 3.0, and 1.1% of readings, respectively. This proposed MRI classification of interspinous ligament degeneration was simple, reliable, and reproducible. Its use as a standardized nomenclature in clinical and radiographic research may be recommended.

The efficacy of rhBMP-2 versus autograft for posterolateral lumbar spine fusion in elderly patients

Few studies have specifically examined the outcomes following rhBMP-2 usage in patients 65 years and older. The purpose of this retrospective study is to evaluate the efficacy of rhBMP-2 with allograft versus autograft for posterolateral lumbar fusion in patients 65 years and older. One hundred twenty-seven patients were divided into three groups based on fusion material and age. Subjects in group A (n = 34) consisted of patients 65 years and older who received rhBMP-2 and allograft. Group B (n = 52) was composed of patients under 65 years of age with rhBMP-2 and allograft. Subjects in group C (n = 41) were 65 years and older with autograft use. A comparison was made of fusion rate, fusion time (noticed, solid), clinical outcome, VAS, perioperative complications and revision rate between each group. The fusion rate and fusion time were similar in groups A and C; however, these were lower than that observed in group B. Clinical outcomes were similar amongst the groups. There were no significant differences in VAS and perioperative complication rate between groups A and C. In patients 65 years and older, rhBMP-2 with allograft may lead to acceptable fusion rates and fusion times, good clinical outcomes and reduced perioperative complications. The combination of rhBMP-2 with allograft yields equivalent outcomes as autograft in elderly patients undergoing instrumented posterolateral lumbar fusion. Additionally, when compared to patients under 65 years of age undergoing posterolateral lumbar fusion, the use of rhBMP-2 was not sufficient to overcome all aspects of the age-related weakened osteoinductive capacity encountered in elderly patients.