Late tibial interference screw extrusion following anterior cruciate ligament reconstruction: A case report

INTRODUCTION

Interference screws are used as back-up fixation in anterior cruciate ligament reconstructions. Historically these were composed of metal, but recently surgeons have switched to using bioabsorbable screws as they cause less symptoms and are biomedically advantageous. Usually these screws are absorbed by the body within one to two years after surgery.

CASE PRESENTATION

A 32-year-old male presented with aseptic extrusion of his intact tibial bioabsorbable interference screw eight years following successful anterior cruciate ligament reconstruction.

MANAGEMENT AND OUTCOMES

Patient underwent laboratory evaluation and magnetic resonance imaging to rule out infection as an underlying cause. He went on to heal the wound without complication.

CONCLUSION

Late aseptic extrusion of tibial interference screw can occur; however, infectious etiologies should be carefully ruled out.

Is Self-reported Return to Duty an Adequate Indicator of Return to Sport and/or Return to Function in Military Patients?

BACKGROUND

In the military, return-to-duty status has commonly been used as a functional outcome measure after orthopaedic surgery. This is sometimes regarded similarly to return to sports or as an indicator of return to full function. However, there is variability in how return-to-duty data are reported in clinical research studies, and it is unclear whether return-to-duty status alone can be used as a surrogate for return to sport or whether it is a useful marker for return to full function.

QUESTIONS/PURPOSES

(1) What proportion of military patients who reported return to duty also returned to athletic participation as defined by self-reported level of physical activity? (2) What proportion of military patients who reported return to duty reported other indicators of decreased function (such as nondeployability, change in work type or level, or medical evaluation board)?

METHODS

Preoperative and postoperative self-reported physical profile status (mandated physical limitation), physical activity status, work status, deployment status, military occupation specialty changes, and medical evaluation board status were retrospectively reviewed for all active-duty soldiers who underwent orthopaedic surgery at Madigan Army Medical Center, Joint Base Lewis-McChord from February 2017 to October 2018. Survey data were collected on patients preoperatively and 6, 12, and 24 months postoperatively in all subspecialty and general orthopaedic clinics. Patients were considered potentially eligible if they were on active-duty status at the time of their surgery and consented to the survey (1319 patients). A total of 89% (1175) were excluded since they did not have survey data at the 1 year mark. Of the remaining 144 patients, 9% (13) were excluded due to the same patient having undergone multiple procedures, and 2% (3) were excluded for incomplete data. This left 10% (128) of the original group available for analysis. Ninety-eight patients reported not having a physical profile at their latest postoperative visit; however, 14 of these patients also stated they were retired from the military, leaving 84 patients in the return-to-duty group. Self-reported "full-time duty with no restrictions" was originally used as the indicator for return to duty; however, the authors felt this to be too vague and instead used soldiers' self-reported profile status as a more specific indicator of return to duty. Mean length of follow-up was 13 ± 3 months. Eighty-three percent (70 of 84) of patients were men. Mean age at the preoperative visit was 35 ± 8 years. The most common surgery types were sports shoulder (n = 22) and sports knee (n = 14). The subgroups were too small to analyze by orthopaedic procedure. Based on active-duty status and requirements of the military profession, all patients were considered physically active before their injury or surgery. Return to sport was determined by asking patients how their level of physical activity compared with their level before their injury (higher, same, or lower). We identified the number of other indicators that may suggest decreased function by investigating change in work type/level, self-reported nondeployability, or medical evaluation board. This was performed with a simple survey.

RESULTS

Of the 84 patients reporting return to duty at the final follow-up, 67% (56) reported an overall lower level of physical activity. Twenty-seven percent (23) reported not returning to the same work level, 32% (27) reported being nondeployable, 23% (19) reported undergoing a medical evaluation board (evaluation for medical separation from the military), and 11% (9) reported a change in military occupation specialty (change of job description).

CONCLUSION

Return to duty is commonly reported in military orthopaedics to describe postoperative functional outcome. Although self-reported return to duty may have value for military study populations, based on the findings of this investigation, surgeons should not consider return to duty a marker of return to sport or return to full function. However, further investigation is required to see to what degree this general conclusion applies to the various orthopaedic subspecialties and to ascertain how self-reported return to duty compares with specific outcome measures used for particular procedures and subspecialties.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

The Effect of Subcritical Bone Loss and Exposure on Recurrent Instability After Arthroscopic Bankart Repair in Intercollegiate American Football

BACKGROUND

There is no consensus on the optimal method of stabilization (arthroscopic or open) in collision athletes with anterior shoulder instability.

PURPOSE

To examine the effect of "subcritical" bone loss and football-specific exposure on the rate of recurrent shoulder instability after arthroscopic stabilization in an intercollegiate American football population.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Fifty intercollegiate football players underwent primary arthroscopic stabilization for anterior shoulder instability and returned to football for at least a single season. Preoperatively, 32 patients experienced recurrent subluxations, and 18 patients experienced a single or recurrent dislocation. Shoulders with glenoid bone loss >20%, an engaging Hill-Sachs lesion, an off-track lesion, and concomitant rotator cuff repair were excluded from the study. The primary outcome of interest was the ability to return to football without subsequent instability. Patients were followed for time to a subsequent instability event after return to play using days of exposure to football and total follow-up time after arthroscopic stabilization.

RESULTS

Fifty consecutive patients returned to American football for a mean 1.5 seasons (range, 1-3) after arthroscopic stabilization. Three of 50 (6%; 95% CI, 1.3%-16.5%) patients experienced recurrent instability. There were no subsequent instability events after a mean 3.2 years of military service. All shoulders with glenoid bone loss >13.5% (n = 3) that underwent arthroscopic stabilization experienced recurrent instability upon returning to sport, while none of the shoulders with <13.5% glenoid bone loss (n = 47) sustained a recurrent instability event during football ( X² = 15.80, P < .001). Shoulders with >13.5% glenoid bone loss had an incidence rate of 5.31 cases of recurrent instability per 1000 athlete-exposures of football. In 72,000 athlete-exposures to football with <13.5% glenoid bone loss, there was no recurrent instability. Significantly more anchors were used during the primary arthroscopic stabilization procedure in patients who experienced multiple preoperative instability events ( P = .005), and lesions spanned significantly more extensive portions along the circumference of the glenoid ( P = .001) compared with shoulders having a single preoperative instability event before surgical stabilization.

CONCLUSION

Arthroscopic stabilization of anterior shoulder instability in American football players with <13.5% glenoid bone loss provides reliable outcomes and low recurrence rates.

Current recommendations for anterior cruciate ligament bracing: when to use

Braces are often used during various stages of recovery from an anterior cruciate ligament tear despite there being sparse definitive research supporting their use. This article reviews the literature on brace use for patients with anterior cruciate ligament tears in order to provide a guide for clinicians. There is evidence to support immediate postoperative bracing, with the goals of maintaining full extension and decreasing effusion. There may be a psychological benefit for its use in return to sport; however, this should be weighed against decreased performance. In the context of modern graft-fixation techniques and early mobilization protocols, empiric functional brace prescription is not required for successful long-term clinical outcomes and return to sport.

Acute compartment syndrome of the thigh in combat casualties

Acute compartment syndrome of the thigh is a rare clinical entity often caused by high-energy trauma and presenting with a spectrum of associated injuries. Service members in combat are at risk for these causative mechanisms. This study presents a large cohort of thigh compartment syndrome combat casualties and investigates the injury mechanisms, associated mortality, and complications related to fasciotomies. Blasts were the most frequent injury mechanism, overall mortality was 23%, burns were associated with a higher mortality, and fasciotomy morbidity was reported by all respondents. The mortality was similar to civilian cohorts with thigh compartment syndrome and was isolated to patients with high Injury Severity Scores. While mortality associated with this injury is high, it is likely related to associated injury patterns rather than the compartment syndrome itself. Thigh compartment fasciotomies carried significant morbidity, consistent with civilian trauma publications.

Intra-articular risks of suprapatellar nailing

To determine the risks to local anatomy near the starting point for tibial nailing during suprapatellar nailing, 15 fresh-frozen hemipelvis specimens were nailed using a suprapatellar technique. After nail passage, the menisci and articular surfaces, anterior cruciate ligament (ACL) insertion, intermeniscal ligament, and fat pad were assessed for injury. The distance from the entry portal to the menisci, articular surfaces, and ACL insertion was determined. Medial meniscus injury occurred in 1 (6.7%) specimen and medial articular injury in 2 (13%). Nails passed through the fat pad in all specimens; intermeniscal ligament injury occurred in 3 (20%) specimens. The ACL insertion and lateral structures were not injured in any specimen. The distance from the entry portal margin to the lateral and medial menisci was 6.46±2.47 mm and 4.74±3.17 mm, respectively. The distances to the lateral and medial articular margins measured 10.33±3.62 mm and 6.54±3.57 mm, respectively. The distance to the ACL insertion averaged 5.80±3.94 mm. Suprapatellar nailing is associated with a risk of injury to anterior knee structures comparable to other nailing techniques. Additional clinical studies are warranted to further define the role of this technique in the management of tibial fractures.

Publication rates of abstracts presented at the annual meeting of the Society of Military Orthopaedic Surgeons

Previous studies have reported publication rates of abstracts presented at orthopaedic meetings from 22 to 68 percent. The objective of this study was to determine the publication rate of papers presented at the Society of Military Orthopaedic Surgeons (SOMOS) meetings from 1999 to 2003. A database was created including all abstracts presented at SOMOS meetings from 1999 to 2003 as listed in official program books. To assess whether each abstract resulted in publication in a peer-reviewed journal, a computerized PubMed search of the presenting author and appropriate keywords from the title was conducted. Overall, 191 of the 435 abstracts presented at SOMOS from 1999 to 2003 were published in a peer-reviewed journal, giving a publication rate of 44%. The publication rate of abstract presentations at annual SOMOS meetings compares favorably with the rates for other orthopaedic meetings. However, less than 50% result in peer-reviewed publication.

Characteristics and impact of animal models used for sports medicine research

Animal models are commonly used for translational research despite evidence that the methodology of these studies is often inconsistent and substandard. This study describes the characteristics and impact of published research using animal models in the American Journal of Sports Medicine (AJSM). Peer-reviewed articles published in the AJSM between January 1990 and January 2010 using animal models were identified using MEDLINE. The articles were reviewed for funding source, anesthesia used, animal used, study type, study location, outcome measures, number of animals, duration of animal survival, main topic being studied, and positive or negative treatment effect. The impact factor of the studies published between 2005 and 2010 was calculated. Two hundred fifty-seven articles, or 6% (257/4278) of the total publications during the 20-year period, were analyzed. The impact factor increased from 1.83 in 2005 to 3.9 in 2010. The most common animals used were rabbits (24%) and pigs (16%). The anterior cruciate ligament was studied in 34% of the articles, and a pig model was used for 31% of these studies. Eighty-six percent of the studies had a positive treatment effect. This study shows that animal models used in sports medicine research lack uniformity in their methods and suggests that a publication bias may exist for animal research in the sports medicine literature.

Bacterial adherence to titanium, poly-L-lactic acid, and composite hydroxyapatite and poly-L-lactic acid interference screws

This study investigates a potential site of bacterial adherence, the implant surface, comparing titanium, poly-L-lactic acid (PLLA), and composite hydroxyapatite and poly-L-lactic acid (PLLA-HA) interference screws using a bioluminescent in vitro model. Interference screws of three materials, titanium (Arthrex, Naples, FL), bioabsorbable poly-L-lactic acid (BIORCI, Smith & Nephew, Andover, MA), and bioabsorbable composite hydroxyapatite and poly-L-lactic acid (BIORCI-HA, Smith & Nephew, Andover, MA) were immersed in a broth of bioluminescent Staphylococcus aureus. The screws were irrigated and then imaged with a photon-capturing camera system yielding a total photon count correlating with residual adherent bacteria. The titanium screws had the lowest mean total bacterial counts followed by the PLLA-HA screws and with the PLLA screws having the highest mean total counts. The difference in means between the titanium group and the PLLA group was statistically significant (p < .001). Titanium interference screws have less bacterial adherence than comparable bioabsorbable PLLA screws.

Silver dressings augment the ability of negative pressure wound therapy to reduce bacteria in a contaminated open fracture model

BACKGROUND

Despite a lack of evidence supporting their use, silver dressings are often used with negative pressure wound therapy (NPWT). This study investigates the effectiveness of silver dressings to reduce bacteria in contaminated wounds when used with NPWT.

METHODS

Complex orthopedic wounds were created on the proximal left legs of anesthetized goats. The wounds were inoculated with either a strain of bioluminescent Pseudomonas aeruginosa or Staphylococcus aureus. These bacteria are genetically modified to emit photons, thereby allowing quantification of bacterial concentration with a photon-counting camera system. The wounds were debrided 6 hours after inoculation and were treated with silver impregnated gauze combined with NPWT. Repeat debridements were performed every 48 hours for 6 days. Imaging was performed pre- and postdebridement. These results were compared with standard NPWT controls that used dressings without silver.

RESULTS

There were fewer bacteria in the silver groups than the standard NPWT groups at 6 days. In the groups that were inoculated with P. aeruginosa, wounds in the silver group contained 21% ± 5% of baseline bacterial load compared with 43% ± 14% in the standard NPWT group. The addition of the silver dressings has a more pronounced effect on Staphylococcus. Wounds in the silver group contained 25% ± 8% of baseline bacterial load compared with 115% ± 19% in the standard NPWT group.

CONCLUSIONS

The use of silver dressings with NPWT is a fairly common practice with limited literature to support its use in contaminated wounds. This study demonstrates that the addition of a silver dressing to NPWT effectively reduces bacteria in contaminated wounds and is more beneficial on the gram-positive bacteria. These data support the use of silver dressings in contaminated wounds, particularly ones contaminated by S. aureus.

Bacterial adherence to suture materials

BACKGROUND

Wound infections may be problematic for physicians. Whether a practitioner is managing complex penetrating trauma or a skin biopsy, there may be a need for suture closure. Suture material is an operator dependent variable and while little objective data exist to guide the choice of suture, it may play a role in wound infection. This study evaluates bacterial adherence to commonly used suture materials with a bioluminescent in vitro model.

METHODS

In all, 11 strands of size 2-0 poliglecaprone suture (Monocryl; Ethicon, Inc, Somerville, New Jersey), polypropylene suture (Prolene; Ethicon, Inc), silk suture (Ethicon, Inc), polyglycolic acid suture (Vicryl; Ethicon, Inc), and antimicrobial polyglycolic acid suture treated with triclosan (VicrylPlus; Ethicon, Inc) were immersed in a broth of Staphylococcus aureus engineered to emit photons. After biofilm formation, the suture strands were irrigated and imaged with a photon-capturing camera system yielding a total photon count that correlates with residual bacteria.

RESULTS

The Vicryl suture had the highest counts and was statistically significant in bacterial adherence versus all other sutures. No other suture material was significantly different from any other.

CONCLUSIONS

This study gives data to guide the selection of suture materials. Absorbable braided suture should not be used in closure of contaminated wounds or wounds at risk for developing infection. The antibiotic impregnated absorbable braided suture was similar to the other suture types; however, it is at risk for reverting to the properties of its untreated counterpart over time. The bacterial adherence of suture materials should be taken into account by all practitioners when closing wounds or debriding infected wounds.

Safety analysis of all-inside arthroscopic repair of peripheral triangular fibrocartilage complex

PURPOSE

The purpose of this study was to determine whether an all-inside peripheral triangular fibrocartilage complex (TFCC) repair using the FasT-Fix device (Smith & Nephew Endoscopy, Andover, MA) is safe by measuring the proximity of the anchors to ulnar-sided anatomic structures.

METHODS

Eleven fresh-frozen cadaveric wrists were thawed and placed in traction. Under direct arthroscopic visualization, an all-inside arthroscopic peripheral TFCC repair was completed by placing a single FasT-Fix device in a vertical mattress fashion. The wrists were then dissected to visualize the 2 anchors. The distance between these anchors and the flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), and dorsal branch of the ulnar sensory nerve (DBUN) were measured with digital calipers and recorded.

RESULTS

The peripheral anchor averaged 4.2 mm (range, 0 to 14 mm) from the ECU tendon, 3.8 mm (range, 0 to 9 mm) from the DBUN, and 8.3 mm (range, 1 to 15 mm) from the FCU tendon. The central anchor averaged 9.6 mm (range, 2 to 15 mm) from the ECU tendon, 6.8 mm (range, 1 to 13 mm) from the DBUN, and 7.6 mm (range, 1 to 13 mm) from the FCU tendon.

CONCLUSIONS

This study exposes some safety concerns with the all-inside peripheral TFCC repair using the FasT-Fix device, which was found to reside in close proximity to the ECU, FCU, and DBUN. In multiple wrists the anchors were noted to underlie the anatomic structure that we measured, making it possible to pierce these structures with the needle before deployment of the anchor.

CLINICAL RELEVANCE

Though technically feasible, all-inside arthroscopic repair of the peripheral TFCC risks injury to the ulnar-sided anatomy.