Management of Intraoperative Graft-related Challenges in Anterior Cruciate Ligament Reconstruction.

Anterior cruciate ligament reconstruction (ACLR) is one of the most frequently performed procedures in orthopaedic sports medicine. Intraoperative challenges related to graft procurement, graft preparation, and graft placement are common. Frequently encountered difficulties include insufficient graft diameter and graft-tunnel length mismatches, whereas less frequent challenges may be encountered during graft harvest and handling. This article discusses these possible complications and the strategies for their prevention and management. For successful ACLR, clinicians must be prepared to address each of these potential sources of difficulty.

A retrospective comparison of the incidence of bacterial infection following anterior cruciate ligament reconstruction with autograft versus allograft.

PURPOSE: To compare the incidence of bacterial infection in anterior cruciate ligament (ACL) reconstruction with autograft versus allograft. METHODS: We completed a retrospective medical record review of ACL reconstructions performed at our institutions between 2001 and 2005. These included 170 autograft, 628 allograft, and 3 combined autograft/allograft reconstructions. Data collection included patient demographics, comorbidities, preoperative antibiotics, fixation type, and the occurrence of deep postoperative infection. RESULTS: Of the 801 patients who underwent ACL reconstruction, 6 (0.75%) developed a confirmed deep infection. There were 2 confirmed deep infections in 170 autograft reconstructions (1.2%) compared with 4 confirmed deep infections in 628 allograft reconstructions (0.6%). Multivariate analysis revealed that ACL reconstruction using autograft had a nearly twice the risk of infection compared to allograft reconstructions (adjusted odds ratio, 1.83; 95% confidence interval, 0.16 to 12.94). CONCLUSIONS: This study failed to find a higher rate of deep bacterial infection in ACL reconstructions when allograft tissue was used. We therefore feel that surgeons should consider allograft tissue as an alternative to autograft when there is a concern about donor-site morbidity, or for revision reconstructions. LEVEL OF EVIDENCE: Level III, therapeutic retrospective comparative study.

Ochrobactrum anthropi septic arthritis of the acromioclavicular joint in an immunocompetent 17 year old.

Ochrobactrum anthropi is a ubiquitous, aerobic, gram-negative bacillus of low virulence, most frequently associated with nosocomial infections and infections related to indwelling catheters in immunocompromised hosts. This article presents the first reported case of O anthropi septic arthritis, here occurring at the acromioclavicular joint of an otherwise healthy patient, and provides treatment recommendations based on our experience.

An anatomical study comparing standard fluoroscopy and virtual fluoroscopy for the placement of C1-2 transarticular screws.

OBJECT: The authors sought to compare radiation exposure, surgical time, and accuracy of screw placement when using either standard fluoroscopy or virtual fluoroscopy for the placement of C1-2 transarticular screws. METHODS: Twenty-two C1-2 transarticular screws were placed in 11 cadavers in a randomized and alternating order by using either standard fluoroscopy or virtual fluoroscopy (fluoronavigation). The radiation time, procedure time, and accuracy of screw placement were recorded and statistically compared. A small but statistically significant reduction in fluoroscopy time was noted with the virtual fluoroscopy technique but the surgical times were similar between the two techniques. The incidence of noncritical and critical breaches (those at risk of causing a neurovascular injury) was not significantly different between the two groups. Careful analysis of the C1-2 anatomy in these specimens underscored the importance of placing the screw path in a maximally dorsal and medial portion of the C-2 isthmus to avoid injury to the vertebral artery and to maximize the bone purchase of the C-1 lateral mass. CONCLUSIONS: Although virtual fluoroscopy may represent a useful tool for transarticular screw placement, it does not supplant traditional surgical techniques and does not appear to lower the incidence of bone breaches that can occur when performing this demanding procedure.

Interposition arthroplasty with bone-tendon allograft: a technique for treatment of the unstable sternoclavicular joint.

Sternoclavicular joint instability is an uncommon but challenging clinical problem for the orthopaedic surgeon. Although most cases can be treated nonoperatively with minimal long-term pain or functional limitation, a small percentage may require surgical intervention. This includes chronic anterior instability associated with persistent pain or functional limitation as well as irreducible or recurrent posterior instability. Although numerous procedures have been described for treatment of the unstable sternoclavicular joint, the optimal method for stabilization has not been determined. Here we describe a technique using Achilles tendon allograft to create an interpositional arthroplasty and briefly present 3 illustrative cases in which we performed the procedure. We believe this method effectively stabilizes the joint, restores function, relieves pain, and has applications for traumatic sternoclavicular instability as well as instability related to other etiologies.

Management of bony deficiency in revision anterior cruciate ligament reconstruction using allograft bone dowels: surgical technique.

Revision anterior cruciate ligament (ACL) reconstruction surgery has become increasingly common over the past decade and its popularity is likely to rise further as the number of primary ACL reconstructions increases each year. More than 75% of all cases of failed ACL reconstruction are the result of technical error and, of these, more than 70% are attributed specifically to malpositioned tunnels. Management of tunnel malposition in revision surgery often requires innovative approaches for dealing with the resultant bony defects. In addition, tunnel osteolysis may create bone loss that interferes with desired tunnel placement. A number of options have been described for handling these bony deficiencies, many of which are technically difficult and time consuming. We describe a novel technique to address bony defects during revision ACL reconstruction using freeze-dried allograft bone dowels. These allografts are readily available and can be used easily to fill deficiencies resulting from previous tunnels or osteolysis. The grafts provide sufficient structural support for redrilling of new tunnels through or next to the bony plug, allowing uncompromised tunnel placement.

A cadaveric study comparing standard fluoroscopy with fluoroscopy-based computer navigation for screw fixation of the odontoid.

Although direct osteosynthesis of certain types of odontoid fractures may increase union and decrease the need for prolonged immobilization, screw fixation remains a technically demanding procedure. This study compares radiation exposure, surgical time, and accuracy of hardware placement using standard fluoroscopy versus computer-assisted fluoroscopy-based navigation ("virtual fluoroscopy") to assist with the placement of odontoid screws. Twenty-two cadavers were divided into two groups and underwent placement of a single odontoid screw using either standard fluoroscopic or virtual fluoroscopic guidance. Following screw placement, dissection of the C1-C2 segments was performed to assess accuracy. A significant reduction in fluoroscopy time was noted with the computer-based fluoroscopy technique, whereas the surgical time was not found to differ significantly between the techniques. No critical breaches (those risking neurovascular injury) were noted in either group, and the rate of noncritical breaches did not differ. The authors conclude that fluoroscopy-based virtual navigation appears to have a safety profile similar to standard fluoroscopy while allowing a reduction in radiation exposure.

Semitendinosus regrowth: biochemical, ultrastructural, and physiological characterization of the regenerate tendon.

BACKGROUND: Previous studies have suggested that hamstring tendons can regenerate following harvesting for anterior cruciate ligament reconstruction. HYPOTHESIS: This "neo-tendon" is a true, functional tendon, not scar tissue. STUDY DESIGN: Controlled laboratory study. METHODS: Semitendinosus tendons were harvested from 35 New Zealand white rabbits using a standard tendon stripper. The rabbits were sacrificed 9 to 12 months following the index procedure and thoroughly evaluated. RESULTS: Thirty-one rabbits were available at the time of sacrifice. The neo-tendon was present in 26 rabbits but was highly variable in size and location of its tibial insertion. Histologic and immunohistochemical staining confirmed that the regenerate tissue was indeed tendon with normal cellularity, organization, and immunolocalization of type I collagen. Electron microscopy showed regeneration of organized collagen tissue that simulated native tendon but with a smaller cross-sectional diameter. Functionally, the neo-tendon was able to transmit force across the musculotendinous junction but at a significantly slower rate than the opposite, control leg. Biomechanical properties of the neo-tendon were significantly less than the control side. Biochemical analysis revealed that the neo-tendons contained glycosaminoglycans and collagen, but levels were significantly lower than normal tendons. CONCLUSIONS: Semitendinosus tendons regenerate with biologically reactive tendinous tissues in an animal model. This tissue has many of the characteristics of a normal tendon but appears to be inferior to the original musculotendinous unit at 9- to 12-month evaluation. Further characterization of the "lizard tail phenomenon" is still needed. CLINICAL RELEVANCE: Hamstring tendon regrowth may have a dramatic impact on postoperative function of patients who undergo anterior cruciate ligament reconstruction with these tendons. Further modulation of this regeneration may further reduce graft harvesting morbidity.

Independent drilling outperforms conventional transtibial drilling in anterior cruciate ligament reconstruction.

BACKGROUND: Optimal tunnel placement is critical in anterior cruciate ligament reconstructive surgery, yet the method used to drill the tunnels may compromise their placement. HYPOTHESIS: An independent drilling method versus a conventional transtibial drilling method will place tunnels in different locations and produce reconstructions with different kinematics. STUDY DESIGN: Controlled laboratory study. METHODS: Ten pairs of knees had anterior cruciate ligament reconstructions produced by either a conventional transtibial drilling method or an independent drilling method. The location of the tunnels was recorded, and the knees were tested for laxity in the normal state, with the anterior cruciate ligament removed, and with the anterior cruciate ligament reconstructed. A surgical navigation system guided the placement of the independently drilled tunnels and measured joint laxity in response to various combinations of anterior force and rotational torques. RESULTS: The conventional transtibial drilling method used in this study placed tibial tunnels posterior and femoral tunnels superior relative to their footprints and resulted in more vertical grafts. In contrast, the independently drilled tibial and femoral tunnels were more anterior and central in their respective footprints, resulting in more horizontal grafts. The horizontal grafts of the independent drilling method were superior to the vertical grafts of this study's transtibial drilling method in restoring normal anterior and rotational knee laxity. CONCLUSION: An independent drilling method can produce tunnels with superior function compared with tunnels produced by a conventional transtibial drilling method. CLINICAL RELEVANCE: Single-bundle anterior cruciate ligament reconstructions will be improved if grafts are centered in their anatomical insertions by an independent drilling method versus grafts placed by a conventional transtibial drilling method.

Accelerated hypertrophic chondrocyte kinetics in GDF-7 deficient murine tibial growth plates.

The Growth/Differentiation Factors (GDFs) are a subgroup of the Bone Morphogenetic Proteins (BMPs) well known for their role in joint formation and chondrogenesis. Mice deficient in one of these signaling molecules, GDF-5, have recently been shown to exhibit a decreased rate of endochondral bone growth in the proximal tibia due to a significantly longer hypertrophic phase duration. GDF-7 is a related family member, which exhibits a high degree of sequence identity with GDF-5. The purpose of the present study was to determine whether GDF-7 deficiency also alters the endochondral bone growth rate in mice and, if so, how this is achieved. Stereologic and cell kinetic parameters in proximal tibial growth plates from 5-week-old female GDF-7 -/- mice and wild type control littermates were examined. GDF-7 deficiency resulted in a statistically significant increase in growth rate (+26%; p = 0.0084) and rate of cell loss at the chondrosseous junction (+25%; p = 0.0217). Cells from GDF-7 deficient mice also exhibited a significantly shorter hypertrophic phase duration compared to wild type controls (-27%; p = 0.0326). These data demonstrate that, in the absence of GDF-7, the rate of endochondral bone growth is affected through the modulation of hypertrophic phase duration in growth plate chondrocytes. These findings further support a growing body of evidence implicating the GDFs in the formation, maturation, and maintenance of healthy cartilage.

An intra-articular knee cyst in a 2-year-old associated with an aberrant anterior cruciate ligament.

Intra-articular ganglia of the knee occur infrequently, with an overall incidence estimated to be from 0.2 to 1.9%. To date, the youngest patient reported with an intra-articular ganglion was an adolescent. In this paper, we describe a 2-year-old patient with a massive intra-articular knee cyst and an aberrant anterior cruciate ligament (ACL) origin. The cyst was successfully treated with arthroscopic debridement. Proposed pathology and treatment recommendations for intra-articular cysts are reviewed.

Increased surgical volume is associated with lower THA dislocation rates.

The presumed correlation between an increasing volume of health care procedures and an improvement in outcomes is sometimes referred to as the practice-makes-perfect effect. Growing interest in outcomes-based research has led to numerous papers examining this relationship for various surgical procedures, including total hip arthroplasty. The results of these studies have important implications for consumers, providers, and healthcare financers. Accordingly, we review the literature to date examining surgeon and hospital volume effects on hip arthroplasty outcomes, with a specific focus on the effects of volume on dislocation. A systemic review of the literature demonstrates a substantial positive association between surgical volumes and improvement in most THA outcomes, including dislocation; that is, increasing surgical volume is associated with lower dislocation rates. This correlation appears to be stronger and is more clearly established for surgeon volumes than it is for hospital volumes.

Traumatic hemipelvectomy: case report and literature review.

Traumatic hemipelvectomy is a rare but devastating injury involving complete disruption of the hemipelvis from the pubic symphysis to the sacroiliac joints and often results in death. We present an interesting case of traumatic hemipelvectomy caused by a previously undescribed mechanism of injury in which judicious angiography and aggressive surgical treatment contributed to patient survival.

Factors affecting forearm compartment pressures in children with supracondylar fractures of the humerus.

This study evaluated forearm compartment pressures in 29 children with supracondylar humerus fractures. Pressures were measured before and after reduction in the dorsal, superficial volar, and deep volar compartments at the proximal 1/6th and proximal 1/3rd forearm. Pressures in the deep volar compartment were significantly elevated compared with pressures in other compartments. There were also significantly higher pressures closer to the elbow within each compartment. Fracture reduction did not have a consistent immediate effect on pressures. The effect of elbow flexion on post-reduction pressures was also evaluated; flexion beyond 90 degrees produced significant pressure elevation. We conclude that forearm pressures after supracondylar fracture are greatest in the deep volar compartment and closer to the fracture site. Pressures greater than 30 mm Hg may exist without clinical evidence of compartment syndrome. To avoid unnecessary elevation of pressures, elbows should not be immobilized in >90 degrees of flexion after these injuries.

Ash content modulation of torsionally derived effective material properties in cortical mouse bone.

The purpose of this study was to evaluate the effects of isolated alterations in mineral content on mouse bone torsional properties. The femora and tibiae from 25 eight-week-old male A/J strain mice were divided into five groups and selectively decalcified from 5% to 20%. The right femora were then tested to failure in torsion while the tibiae were ashed to determine final mineral content of the decalcified bones. Contralateral femora were serially cross-sectioned to determine geometric properties, and effective material properties were then calculated from the geometric and structural properties of each femoral pair. We found that the relationship between ash content and effective shear modulus or maximum effective shear stress could best be characterized through a power law, with an exponential factor of 6.79 (R2 = 0.85) and 4.04 (R2 = 0.67), respectively. This indicates that in a murine model, as with other species, small changes in ash content significantly influence effective material properties. Furthermore, it appears that (in adolescent A/J strain mice) effective shear modulus is more heavily affected by changes in mineralization than is maximum effective shear stress when these properties are derived from whole bone torsional tests to failure.