James A. Rand Young Investigator's Award: Questioning the "Nickel Free" Total Knee Arthroplasty.

BACKGROUND: A study was performed to measure metal ions present in the knee joint after performing a total knee arthroplasty (TKA) with standard cobalt chromium (CoCr) components as well as with "nickel-free" oxidized zirconium femoral and titanium tibial (OxZr/Ti) components. METHODS: Knee joint fluid was collected prior to arthrotomy, and on postoperative day one to determine the amount of metal debris generated when performing a TKA with standard instrumentation from consecutive cases with CoCr components (n = 24) and OxZr/Ti components (n = 16). RESULTS: CoCr implant patients had statistically higher levels of nickel (Ni) (29.7%, P = .033), cobalt (Co), (1,100.7%, P < .0001) and chromium (Cr) (118.9%, P < .0001) postoperatively. The cutting blocks and sawblades do not contain Co, which therefore must have come from the components. The metal ions generated from the sawblades and cutting blocks, therefore, could be discerned from the OxZr/Ti whose components don't contain Co, Cr, or Ni. The OxZr patients had significantly higher Cr (9.5×, P < .001) and Ni (5.1×, P < .001) post-TKA vs pre-TKA; Co levels were not significantly different as expected with the absence of Co in the components (P = .60). The Ni levels generated in performing an Oxinium TKA was 3.3 times higher than when performing a CoCr TKA (1.37 vs. 41 ppb, P < .001). CONCLUSIONS: The substantial degree of Ni generation resulting from performing a hypoallergenic "nickel-free" TKA calls into questions the rationale of utilizing more expensive lower Ni components on the basis of known or suspected Ni or Cr allergy.

Early-Career Sports Medicine Surgeons Perform a Large Volume of Non-Sports Medicine Procedures: American Board of Orthopaedic Surgery (ABOS) Part-II Data Regarding Orthopaedic Surgeons Specializing in Sports Medicine.

BACKGROUND: The purpose of this study was to utilize the American Board of Orthopaedic Surgery (ABOS) Part-II Case List database to (1) define the practice patterns of sports medicine-trained ABOS Part- II Oral Examination Candidates and (2) describe the frequency and practice patterns of individuals who are dual fellowship-trained sports medicine candidates. METHODS: The ABOS Part-II Case List database was utilized to define all cases submitted by 3,298 applicants indicating completion of a sports medicine fellowship between January 1, 2003, and January 1, 2020. Cases were classified by subspecialty category and case type. The frequency and practice patterns of candidates pursuing additional fellowship training (i.e., "dual fellowship-trained") were recorded. Descriptive statistical methods were used to describe the annual and overall procedure volume and candidate case mix. Trends in the relative frequency of cases performed and fellowship training patterns were determined using linear regression analysis. RESULTS: On average, sports medicine-trained candidates submitted 100.6 cases for review during the 6-month case collection period: 59.0 (58.6%) sports medicine/arthroscopy cases, 29.3 (29.1%) trauma/general cases, 4.5 (4.5%) adult reconstruction cases, and 7.8 (7.8%) "other" cases per candidate. Although candidates performed fewer total (r 2 = 0.84, p < 0.001) and sports medicine/arthroscopy (r 2 = 0.85, p < 0.001) cases over the study period, the proportion of sports medicine/arthroscopy cases did not change over the study period (p = 0.18). Dual fellowship training was indicated by 333 individuals (10.1%). The number of dual fellowship-trained candidates pursuing additional fellowship training in pediatrics and adult reconstruction increased over the study period, and the number of dual fellowship-trained candidates pursuing additional fellowship training in trauma decreased over the study period. CONCLUSIONS: Early-career sports medicine candidates are likely to perform >40% of cases outside of the sports medicine subspecialty. Sports medicine trainees are increasingly likely to pursue a second fellowship in pediatrics or adult reconstruction. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Local delivery of tobramycin and vancomycin in primary total knee arthroplasty achieves minimum inhibitory concentrations for common bacteria causing acute prosthetic joint infection.

AIMS: The aim of this study was to determine if the local delivery of vancomycin and tobramycin in primary total knee arthroplasty (TKA) can achieve intra-articular concentrations exceeding the minimum inhibitory concentration thresholds for bacteria causing acute prosthetic joint infection (PJI). METHODS: Using a retrospective single-institution database of all primary TKAs performed between January 1 2014 and May 7 2019, we identified patients with acute PJI that were managed surgically within 90 days of the initial procedure. The organisms from positive cultures obtained at the time of revision were tested for susceptibility to gentamicin, tobramycin, and vancomycin. A prospective study was then performed to determine the intra-articular antibiotic concentration on postoperative day one after primary TKA using one of five local antibiotic delivery strategies with tobramycin and/or vancomycin mixed into the polymethylmethacrylate (PMMA) or vancomycin powder. RESULTS: A total of 19 patients with acute PJI after TKA were identified and 29 unique bacterial isolates were recovered. The mean time to revision was 37 days (6 to 84). Nine isolates (31%) were resistant to gentamicin, ten (34%) were resistant to tobramycin, and seven (24%) were resistant to vancomycin. Excluding one Fusobacterium nucleatum, which was resistant to all three antibiotics, all isolates resistant to tobramycin or gentamicin were susceptible to vancomycin and vice versa. Overall, 2.4 g of tobramycin hand-mixed into 80 g of PMMA and 1 g of intra-articular vancomycin powder consistently achieved concentrations above the minimum inhibitory concentrations of susceptible organisms. CONCLUSION: One-third of bacteria causing acute PJI after primary TKA were resistant to the aminoglycosides commonly mixed into PMMA, and one-quarter were resistant to vancomycin. With one exception, all bacteria resistant to tobramycin were susceptible to vancomycin and vice versa. Based on these results, the optimal cover for organisms causing most cases of acute PJI after TKA can be achieved with a combination of tobramycin mixed in antibiotic cement, and vancomycin powder. Cite this article: Bone Joint J 2020;102-B(6 Supple A):163-169.

Ease of tying arthroscopic knots.

To date, there is no comprehensive study that determines which arthroscopic knots are easiest to learn to tie. In this study, 23 surgeons in training graded 10 arthroscopic knots with regard to ease of learning and tying using a 10-cm visual analog scale for No. 2 Ethibond and No. 1 polydioxanone (PDS) II suture. Statistical analysis was performed with analysis of variance and the Tukey Studentized range (HSD) test for post hoc analysis with a significant value of P < .05. The Tennessee slider, Duncan loop, Revo knot, and Nicky's knot were the easiest knots to tie by use of both Ethibond and PDS suture. The Field knot and double-twist knot were consistently the hardest knots to tie. Knots tied with Ethibond were easier to tie than knots tied with PDS. Novice surgeons should consider using the Revo knot when developing their arthroscopic knot-tying skills. Once they have mastered this knot, they can consider adding more difficult knots to their repertoire.

Incorporating evidence-based medicine in arthroscopic knot preferences: a survey of american orthopaedic society for sports medicine members.

An Internet-based survey was used to determine arthroscopic knot preferences. Inclusion criteria included American Orthopaedic Society for Sports Medicine (AOSSM) membership, and exclusion criteria included physician members without an e-mail address and nonphysician members. Our hypotheses were that the majority of arthroscopic knots used in clinical practice by AOSSM members are described in the orthopedic literature and have undergone biomechanical analysis, that the majority of members reinforced sliding arthroscopic knots with 3 reversed half-hitches on alternating posts (RHAPs), and that the majority of members used a half-hitch configuration that incorporates at least 3 reversed half-hitches and 3 alternating posts. Of the 1844 members contacted, 937 (50.8%) agreed to participate in the survey. The most common arthroscopic sliding knot used was the Duncan loop. Only 48.1% of respondents used 3 reversed half-hitches and at least 3 alternating posts when using nonsliding knots. Only 31% of respondents used 3 RHAPs to reinforce arthroscopic sliding knots. Only a minority of respondents used the optimal configuration determined in vitro for sliding knot reinforcement and when using a nonsliding half-hitch knot configuration. An evidence-based approach is recommended for determining arthroscopic knot preference for clinical use.

Descriptive epidemiology of the Multicenter ACL Revision Study (MARS) cohort.

BACKGROUND: Revision anterior cruciate ligament (ACL) reconstruction has worse outcomes than primary reconstructions. Predictors for these worse outcomes are not known. The Multicenter ACL Revision Study (MARS) Group was developed to perform a multisurgeon, multicenter prospective longitudinal study to obtain sufficient subjects to allow multivariable analysis to determine predictors of clinical outcome. PURPOSE: To describe the formation of MARS and provide descriptive analysis of patient demographics and clinical features for the initial 460 enrolled patients to date in this prospective cohort. STUDY DESIGN: Cross-sectional study; Level of evidence, 2. METHODS: After training and institutional review board approval, surgeons began enrolling patients undergoing revision ACL reconstruction, recording patient demographics, previous ACL reconstruction methods, intra-articular injuries, and current revision techniques. Enrolled subjects completed a questionnaire consisting of validated patient-based outcome measures. RESULTS: As of April 1, 2009, 87 surgeons have enrolled a total of 460 patients (57% men; median age, 26 years). For 89%, the reconstruction was the first revision. Mode of failure as deemed by the revising surgeon was traumatic (32%), technical (24%), biologic (7%), combination (37%), infection (<1%), and no response (<1%). Previous graft present at the time of injury was 70% autograft, 27% allograft, 2% combination, and 1% unknown. Sixty-two percent were more than 2 years removed from their last reconstruction. Graft choice for revision ACL reconstruction was 45% autograft, 54% allograft, and more than 1% both allograft and autograft. Meniscus and/or chondral damage was found in 90% of patients. CONCLUSION: The MARS Group has been able to quickly accumulate the largest revision ACL reconstruction cohort reported to date. Traumatic reinjury is deemed by surgeons to be the most common single mode of failure, but a combination of factors represents the most common mode of failure. Allograft graft choice is more common in the revision setting than autograft. Concomitant knee injury is extremely common in this population.

Metatarsal shaft fractures and fractures of the proximal fifth metatarsal.

Metatarsal fractures represent a relatively common injury, especially in athletes. The pertinent anatomy, evaluation, diagnosis, classification, and treatment of acute and chronic (stress) metatarsal shaft fractures are discussed. Fractures of the proximal fifth metatarsal, which are unique and important injuries, are also discussed. Treatment remains relatively straightforward for the traumatic metatarsal injury, whereas traditional stress fractures typically heal with decreased activity. The problematic proximal fifth metatarsal fracture (Jones fracture) frequently requires surgical intervention in patients who want to avoid non-weight-bearing cast immobilization. The authors' current treatment for this fracture includes the option of intramedullary fixation versus cast immobilization.