Joshua S. Everhart

A case-control study of anterior cruciate ligament volume, tibial plateau slopes and intercondylar notch dimensions in ACL-injured knees ☆

The role played by anatomical factors in ACL injury remains elusive. In this study, objective methods were used to characterize ACL volume, tibial slopes and notch geometry from ACL-injured and matched-control subjects. The study tested four hypotheses: (1) the medial tibial plateau slope is steeper posteriorly in the injured group compared to the non-injured group, (2) the lateral tibial plateau slope is steeper posteriorly in the injured group compared to the non-injured group, (3) the femoral intercondylar notch dimensions are smaller in the injured group compared to the non-injured group and (4) the ACL volume, tibial plateau slopes and intercondylar notch dimensions are all independent of each other. Fifty-four subjects were divided into two groups, those who had suffered a non-contact ACL injury and those who still had two healthy ACLs, matched to the injured subjects by gender, age, height and weight. The lateral tibial plateaus in the uninjured contralateral knees of the injured subjects had a significantly steeper posterior slope (1.8 degrees vs. -0.3 degrees ), a factor that potentially contributed to the ACL injury in the opposite knee. The intercondylar notch dimensions were found to be smaller in the injured subjects, potentially putting the ACL at risk of impingement, and intercondylar notch volume was correlated to ACL volume (r=0.58). Discriminant analysis showed that the notch width at the inlet was the best single predictor of ACL injury.

Association of Noncontact Anterior Cruciate Ligament Injury With Presence and Thickness of a Bony Ridge on the Anteromedial Aspect of the Femoral Intercondylar Notch

Background: Noncontact anterior cruciate ligament injuries are among the most common injuries in sports medicine, and identification of risk factors for noncontact injury is an area of active research. Hypothesis: Evaluation of the femoral notch along the path of the anterior cruciate ligament may elucidate anatomical risk factors previously unseen on conventional images. Study Design: Case-control study; Level of evidence, 3. Methods: Twenty-seven patients with noncontact anterior cruciate ligament injuries were matched to healthy individuals for height, weight, age, and sex in this case-control study. Sagittal magnetic resonance images of the contralateral knee of the injured patients and randomized knees of the healthy controls were digitally transformed for viewing along the plane of the anterior cruciate ligament and evaluated for abnormalities of femoral notch outlet shape. Femoral notch shape was also evaluated by computer-generated surface models of the knee. Results: A bone ridge was observed on the medial side of the anterior notch outlet, and increasing ridge thickness was strongly associated with noncontact anterior cruciate ligament injury (3.87 ± 2.17 mm in injured and 2.16 ±1.80 mm in controls; P = .0014). Anterior and posterior femoral notch outlet stenosis were both significantly associated with noncontact anterior cruciate ligament injury (P = .0008 and .02, respectively), although anterior outlet stenosis became nonsignificant when stratified by the presence of an anteromedial bone ridge. Finally, images directed through the femoral notch with the knee at 45° of flexion provided an unobstructed view for ridge detection that may be utilized in plain radiography. Conclusion: The presence and thickness of an anteromedial bone ridge in the femoral notch has been identified as a potential risk factor for noncontact anterior cruciate ligament injury. A biomechanical injury model involving the femoral notch ridge in anterior cruciate ligament tears is proposed in which the anterior cruciate ligament may be tented and stretched over the anteromedial notch ridge during knee valgus and internal tibial rotation; alternatively, the anterior cruciate ligament may be impinged at the lateral anterior outlet wall during knee valgus and external tibial rotation. Further investigation to determine the origin of the bone ridges and the validity of the proposed injury model is recommended.

Psychological Factors Affecting Rehabilitation and Outcomes Following Elective Orthopaedic Surgery.

Orthopaedic surgery often requires many months of rehabilitation to achieve a successful outcome, regardless of subspecialty. Several important psychological factors strongly influence pain perceptions, rehabilitation compliance, and patient outcomes after common orthopaedic surgeries that require extensive rehabilitation, including total joint arthroplasty, anterior cruciate ligament reconstruction, and spine surgery for degenerative disease. Early recognition of patients exhibiting psychological distress, fear-avoidance behavior, or poor perceived self-efficacy or pessimistic personality traits can be used to improve preoperative risk stratification for poor rehabilitation or surgical outcomes. Several intervention strategies exist to address these psychological factors when they appear to contribute suboptimal postoperative rehabilitation or recovery.

Correlation between histological outcome and surgical cartilage repair technique in the knee: A meta-analysis☆☆☆

BACKGROUND Compare histological outcomes after microfracture (MF), autologous chondrocyte implantation (ACI), and osteochondral autograft transfer (OATS). METHODS Literature review using PubMed MEDLINE, SCOPUS, Cumulative Index for Nursing and Allied Health Literature (CINAHL), and Cochrane Collaboration Library. Inclusion criteria limited to English language studies International Cartilage Repair Society (ICRS) grading criteria for cartilage analysis after ACI (autologous chondrocyte implantation), MF (microfracture), or OATS (osteochondral autografting) repair techniques. RESULTS Thirty-three studies investigating 1511 patients were identified. Thirty evaluated ACI or one of its subtypes, six evaluated MF, and seven evaluated OATS. There was no evidence of publication bias (Beggs p=0.48). No statistically significant correlation was found between percent change in clinical outcome and percent biopsies showing ICRS Excellent scores (R(2)=0.05, p=0.38). Percent change in clinical outcome and percent of biopsies showing only hyaline cartilage were significantly associated (R(2)=0.24, p=0.024). Mean lesion size and histological outcome were not correlated based either on percent ICRS Excellent (R(2)=0.03, p=0.50) or percent hyaline cartilage only (R(2)=0.01, p=0.67). Most common lesion location and histological outcome were not correlated based either on percent ICRS Excellent (R(2)=0.03, p=0.50) or percent hyaline cartilage only (R(2)=0.01, p=0.67). CONCLUSIONS Microfracture has poorer histologic outcomes than other cartilage repair techniques. OATS repairs primarily are comprised of hyaline cartilage, followed closely by cell-based techniques, but no significant difference was found cartilage quality using ICRS grading criteria among OATS, ACI-C, MACI, and ACI-P. LEVEL OF EVIDENCE IV, meta-analysis.

Physical Exam Risk Factors for Lower Extremity Injury in High School Athletes: A Systematic Review.

Objective:A stated goal of the preparticipation physical evaluation (PPE) is to reduce musculoskeletal injury, yet the musculoskeletal portion of the PPE is reportedly of questionable use in assessing lower extremity injury risk in high school-aged athletes. The objectives of this study are: (1) identify clinical assessment tools demonstrated to effectively determine lower extremity injury risk in a prospective setting, and (2) critically assess the methodological quality of prospective lower extremity risk assessment studies that use these tools. Data Sources:A systematic search was performed in PubMed, CINAHL, UptoDate, Google Scholar, Cochrane Reviews, and SportDiscus. Inclusion criteria were prospective injury risk assessment studies involving athletes primarily ages 13 to 19 that used screening methods that did not require highly specialized equipment. Methodological quality was evaluated with a modified physiotherapy evidence database (PEDro) scale. Main Results:Nine studies were included. The mean modified PEDro score was 6.0/10 (SD, 1.5). Multidirectional balance (odds ratio [OR], 3.0; CI, 1.5-6.1; P < 0.05) and physical maturation status (P < 0.05) were predictive of overall injury risk, knee hyperextension was predictive of anterior cruciate ligament injury (OR, 5.0; CI, 1.2-18.4; P < 0.05), hip external:internal rotator strength ratio of patellofemoral pain syndrome (P = 0.02), and foot posture index of ankle sprain (r = −0.339, P = 0.008). Conclusions:Minimal prospective evidence supports or refutes the use of the functional musculoskeletal exam portion of the current PPE to assess lower extremity injury risk in high school athletes. Limited evidence does support inclusion of multidirectional balance assessment and physical maturation status in a musculoskeletal exam as both are generalizable risk factors for lower extremity injury.

Maximum load to failure of high dose versus low dose gamma irradiation of anterior cruciate ligament allografts: A meta-analysis ☆ ☆☆

BACKGROUND The objective of this study was to systematically evaluate the existing literature to compare the biomechanical effects of low dose and high dose gamma irradiation on commonly used ACL allografts. METHODS A systematic search was performed in PubMed, Cumulative Index for Nursing and Allied Health Literature (CINAHL), Cochrane Reviews, SCOPUS, and SportDiscus. Nine studies were identified that met the following inclusion criteria: 1) controlled laboratory study, 2) investigation of standard allografts for anterior cruciate ligament reconstruction (ACLR), 3) gamma irradiation (dose reported) and a negative control group, and 4) mechanical loading (results reported). RESULTS Nine studies met all inclusion and exclusion criteria. There was a dose-dependent relationship between radiation and decreased mechanical tendon integrity. Low dose radiation (<2.5Mrad [Mrad]) showed graft weakening with an average of 4.3% decrease in load to failure (standardized mean difference [SMD], 0.23; 95% CI 0.216, 0.68; p=0.31), whereas high-dose radiation showed a significantly larger (32.4% average) decrease in load to failure (SMD, 1.79; 95% CI 1.194, 2.38; p<0.001). CONCLUSIONS Gamma irradiation has a negative effect on tendon allograft strength that is dose-dependent, with particularly large effects noted at irradiation doses of ≥2.5Mrad.

Graft Choice in Isolated Medial Patellofemoral Ligament Reconstruction: A Systematic Review With Meta-analysis of Rates of Recurrent Instability and Patient-Reported Outcomes for Autograft, Allograft, and Synthetic Options

PURPOSE To determine whether graft selection or patient age affects the following after isolated medial patellofemoral ligament (MPFL) reconstruction: (1) rates of recurrent instability, (2) rates of postoperative complications (other than instability), and (3) subjective symptom improvement. METHODS A systematic search identified studies reporting outcomes for isolated MPFL reconstruction. Rates of recurrent instability, subjective Kujala knee function scores, and complications were tabulated. Symptom improvement was defined as change in Kujala score (preoperative evaluation to final follow-up). RESULTS Forty-five studies were included with 27 documented cases of recurrent instability among 1,504 patients (1.8%); instability rates ranged from 0% to 20.0% overall; among autograft in adults, 0% to 11.1% (1.4%, 18/1,260); among autograft in adolescents, 0% to 20% (10.0%, 8/80); among allograft, 0% (0/65 cases); and among synthetic, 0% to 3.3% (1.3%, 1/76). Among autograft choices in adults, rates of recurrent instability were low; recurrence with gracilis ranged from 0% to 11.1% (0.9%, 1/116); with semitendinosus, 0% to 6.3% (0.6%, 4/676); with quad or patellar tendon, 0% (0/65); and with adductor tendon, 5.6% to 8.3% (6.7%, 2/30). Complication rates ranged from 0% to 34.4%. All included studies reported significant improvement in Kujala scores after surgery (P < .01). There was significant heterogeneity in effect size and evidence of reporting bias among small studies, precluding reliable pooled analysis of treatment effect. CONCLUSIONS Autograft is not superior to allograft or synthetic grafts for isolated reconstruction of the MPFL, and rates of recurrent instability are generally low. Isolated MPFL reconstruction can provide significant symptom relief regardless of graft selection, although there is a bias toward reporting better than expected results among smaller studies. Pediatric patients and patients treated with adductor tendon autograft have higher recurrent instability rates. While caution should be used in making definitive recommendations secondary to the small number of allograft and synthetic studies, selection of graft type based on surgeon preference, comfort, and prior experience remains appropriate. LEVEL OF EVIDENCE Level IV, systematic review of Level I to IV studies.

When is hemiarthroplasty preferable to intramedullary prophylactic fixation of malignant lesions of the proximal femur

Malignant hip lesions can be managed operatively by intramedullary (IM) nail fixation and hemiarthroplasty.

Development and Validation of a Preoperative Surgical Site Infection Risk Score for Primary or Revision Knee and Hip Arthroplasty.

BACKGROUND Surgical site infection (SSI) is a major complication following total joint arthroplasty. Host susceptibility to infection has emerged as an important predictor of SSI. The purpose of this study was to develop and validate a preoperative SSI risk-assessment tool for primary or revision knee and hip arthroplasty. METHODS Data for 6,789 patients who underwent total joint arthroplasty (from the years 2000 to 2011) were obtained from a single hospital system. SSI was defined as a superficial infection within 30 days or deep infection within 1 year. Logistic regression modeling was utilized to create a risk scoring system for a derivation sample (n = 5,789; 199 SSIs), with validation performed on a hold-out sample (a subset of observations chosen randomly from the initial sample to form a testing set; n = 1,000; 41 SSIs). RESULTS On the basis of logistic regression modeling, we created a scoring system to assess SSI risk (range, 0 to 35 points) that is the point sum of the following: primary hip arthroplasty (0 points); primary knee (1); revision hip (3); revision knee (3); non-insulin-dependent diabetes (1); insulin-dependent diabetes (1.5); chronic obstructive pulmonary disease (COPD) (1); inflammatory arthropathy (1.5); tobacco use (1.5); lower-extremity osteomyelitis or pyogenic arthritis (2); pelvis, thigh, or leg traumatic fracture (2); lower-extremity pathologic fracture (2.5); morbid obesity (2.5); primary bone cancer (4); reaction to prosthesis in the last 3 years (4); and history of staphylococcal septicemia (4.5). The risk score had good discriminatory capability (area under the ROC [receiver operating characteristic] curve = 0.77) and calibration (Hosmer-Lemeshow chi-square test, p = 0.34) and was validated using the independent sample (area under the ROC curve = 0.72). A small subset of patients (5.9%) had a >10% estimated infection risk. CONCLUSIONS The patient comorbidities composing the risk score heavily influenced SSI risk for primary or revision knee and hip arthroplasty. We believe that infection risk can be objectively determined in a preoperative setting with the proposed SSI risk score.

Medical comorbidities and perioperative allogeneic red blood cell transfusion are risk factors for surgical site infection after shoulder arthroplasty

BACKGROUND Multiple perioperative factors have been implicated in infection risk after shoulder arthroplasty. The purpose of this study was to determine surgical site infection (SSI) risk due to medical comorbidities or blood transfusion after primary or revision shoulder arthroplasty. METHODS Comprehensive data on medical comorbidities, surgical indication, perioperative transfusion, and SSI were obtained for 707 patients who underwent primary or revision hemiarthroplasty or total shoulder arthroplasty in a single hospital system. Multivariate Poisson regression was used to determine the independent association between allogeneic red blood cell transfusion, medical comorbidities, and SSI after controlling for procedure. RESULTS The SSI rate was 1.9% for primary hemiarthroplasties and 1.3% for primary total shoulder arthroplasties. Among patients without prior shoulder infection, revision arthroplasty or prior open reduction and internal fixation had higher SSI risk than primary arthroplasties (incidence risk ratio [IRR], 11.4; 95% confidence interval [CI], 3.84-34.0; P < .001); among primary arthroplasties, SSI risk factors included male gender (IRR, 60.0; CI, 4.39-819; P = .002), rheumatoid arthritis (IRR, 8.63; CI, 1.84-40.4; P = .006), and long-term corticosteroid use (IRR, 37.4; CI, 5.79-242; P < .001). Perioperative allogeneic red blood cell transfusion significantly increased SSI risk and was dose dependent (IRR, 1.68 per unit packed red blood cell; CI, 1.21-2.35; P = .002). CONCLUSION Gender, rheumatoid arthritis, and long-term (>1 year) corticosteroid use affect SSI risk after shoulder arthroplasty. Revision surgery, particularly in the setting of prior infection, increased risk of future infection. Finally, allogeneic red blood cell transfusion increases SSI risk after shoulder arthroplasty in a dose-dependent manner.