Interobserver Reliability and Change in the Sagittal Tibial Tubercle-Trochlear Groove Distance with Increasing Knee Flexion Angles

The tibial tubercle-trochlear groove (TT-TG) distance is currently utilized to evaluate knee alignment in patients with patellar instability. Sagittal plane pathology measured by the sagittal tibial tubercle-trochlear groove (sTT-TG) distance has been described in instability but may also be important to consider in patients with cartilage injury. This study aims to (1) describe interobserver reliability of the sTT-TG distance and (2) characterize the change in the sTT-TG distance with respect to changing knee flexion angles. In this cadaveric study, six nonpaired cadaveric knees underwent magnetic resonance imaging (MRI) studies at each of the following degrees of knee flexion: -5, 0, 5, 10, 15, and 20. The sTT-TG distance was measured on the axial T2 sequence. Four reviewers measured this distance for each cadaver at each flexion angle. Intraclass correlation coefficients were calculated to determine interobserver reliability and reproducibility of the sTT-TG measurement. Analysis of variance (ANOVA) tests and Friedman's tests with a Bonferroni's correction were performed for each cadaver to compare sTT-TG distances at each flexion angle. Significance was defined as p < 0.05. There was excellent interobserver reliability of the sTT-TG distance with all intraclass correlation coefficients >0.9. The tibial tubercle progressively becomes more posterior in relation to the trochlear groove (more negative sTT-TG distance) with increasing knee flexion. The sTT-TG distance is a measurement that is reliable between attending surgeons and across training levels. The sTT-TG distance is affected by small changes in knee flexion angle. Awareness of knee flexion angle on MRI is important when this measurement is utilized by surgeons.

Trends and impact of three-dimensional preoperative imaging for anatomic total shoulder arthroplasty

BACKGROUND

The goals of this study were to determine the incidence in the United States of preoperative three-dimensional imaging prior to anatomic total shoulder arthroplasty for osteoarthritis and to determine if preoperative imaging is associated with decreased complication rates.

METHODS

Using a Medicare insurance database, we identified all patients who underwent computed tomography (n = 9380) and/or magnetic resonance imaging (n = 15,653) prior to anatomic total shoulder arthroplasty for a diagnosis of osteoarthritis from 2005 to 2014. The incidence of imaging over time was analyzed and complication rates compared between patients with imaging to matched controls.

RESULTS

The incidence of preoperative three-dimensional imaging significantly increased over time, with computed tomography increasing more than magnetic resonance imaging. Compared to controls, patients with preoperative computed tomography imaging had significantly lower revision rates at two years (odds ratio 0.72 (0.64-0.82), p = 0.008). There were no other significant differences in the other complications studied.

CONCLUSIONS

The use of preoperative three-dimensional imaging for anatomic total shoulder arthroplasty for a diagnosis of osteoarthritis has increased dramatically, with the use of computed tomography increasing the most. Patients who underwent preoperative computed tomography imaging experienced lower revision rates at two years postoperatively compared to matched controls without such imaging.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

The Effect of Acromioplasty on the Critical Shoulder Angle and Acromial Index

Purpose

To evaluate the effect of acromioplasty using a cutting block technique on bony coverage as measured by the critical shoulder angle (CSA) and acromial index (AI).

Methods

This study is a retrospective radiographic review using data from a previous prospective randomized clinical trial that offered enrollment to patients aged 18 years or older with a full-thickness tear of the superior rotator cuff between October 2007 and January 2011. Each patient was allocated to repair with either acromioplasty using a cutting block technique or non-acromioplasty treatment arms in a blinded fashion. Medical and demographic information was recorded for each patient. Between January 2017 and December 2017, patients were contacted for repeat follow-up clinical evaluation and radiographs. Measurements of acromial index and critical shoulder angle were performed on pre- and postoperative radiographs by a single reviewer.

Results

Seventy-one (75%) patients were available for follow up. The 2 groups were similar in terms of baseline demographics and acromial type. When compared with preoperative measures, acromioplasty did not result in significant reductions in mean CSA (34.5° vs 35.5°; P = .293) or AI (0.68 vs 0.66; P = .283). Furthermore, postoperative CSA (34.5° vs 36.2°, P = .052) and AI (0.66 vs 0.67, P = .535) demonstrated no statistically significant differences between patients with and without acromioplasty, respectively.

Conclusions

There was no statistically significant change in either the CSA or AI following acromioplasty, nor was there a significant postoperative difference in CSA or AI between the group that underwent acromioplasty and the group that did not.

Clinical Relevance

Some studies suggest a greater postoperative CSA may result in greater risk of retear after arthroscopic rotator cuff repair. The CSA and AI may not be modifiable with acromioplasty.

Predictors of Osteochondral Lesions of the Talus in Patients Undergoing Broström-Gould Ankle Ligament Reconstruction

Chronic ankle instability is associated with intra-articular and extra-articular ankle pathologies, including osteochondral lesions of the talus. Patients with these lesions are at risk for treatment failure for their ankle instability. Identifying these patients is important and helps to guide operative versus nonoperative treatment. There is no literature examining which patient characteristics may be used to predict concomitant osteochondral lesions of the talus. A retrospective chart review was performed on patients (N = 192) who underwent a primary Broström-Gould lateral ankle ligament reconstruction for chronic ankle instability from 2010 to 2014. Preoperative findings, magnetic resonance imaging, and operative procedures were documented. Patients with and without a lesion were divided into 2 cohorts. Fifty-three (27.6%) patients had 1 lesion identified on preoperative magnetic resonance imaging. Forty (69.0%) of these lesions were medial, 18 (31.0%) were lateral, and 5 patients had both. Female sex was a negative predictor of a concomitant lesion (p = .013). Patients were less likely to have concomitant peroneal tendinopathy (30.2% vs 48.9%; p = .019) in the presence of a lesion. However, sports participation was a positive predictor of a concomitant lesion (p = .001). The remainder of the variables (age, body mass index, smoking, trauma, duration, contralateral instability, global laxity) did not show a significant difference. In patients who underwent lateral ankle ligament reconstruction, females were less likely to have a lesion than males. Patients with peroneal tendinopathy were less likely to have a lesion compared with patients without. Additionally, athletic participation was a positive predictor of a concomitant lesion.

When Would a Metal-Backed Component Become Cost-Effective Over an All-Polyethylene Tibia in Total Knee Arthroplasty?

The importance of cost control in total knee arthroplasty is increasing in the United States secondary to both changing economic realities of healthcare and the increasing prevalence of joint replacement. Surgeons play a critical role in cost containment and may soon be incentivized to make cost-effective decisions under proposed gainsharing programs. The purpose of this study is to examine the cost-effectiveness of all-polyethylene tibial (APT) components and determine what difference in revision rate would make modular metal-backed tibial (MBT) implants a more cost-effective intervention. Markov models were constructed using variable implant failure rates and previously published probabilities. Cost data were obtained from both our institution and published United States implant list prices, and modeled with a 3.0% discount rate. The decision tree was continued over a 20-year timeframe. Using our institutional cost data and model assumptions with a 1.0% annual failure rate for MBT components, an annual failure rate of 1.6% for APT components would be required to achieve equivalency in cost. Over a 20-year period, a failure rate of >27% for the APT component would be necessary to achieve equivalent cost compared with the proposed failure rate of 18% with MBT components. A sensitivity analysis was performed with different assumptions for MBT annual failure rates. Given our assumptions, the APT component is cost-saving if the excess cumulative revision rate increases by <9% in 20 years compared with that of the MBT implant. Surgeons, payers, and hospitals should consider this approach when evaluating implants. Consideration should also be given to the decreased utility associated with revision surgery.

Chronic Nocardia cyriacigeorgica Periprosthetic Knee Infection Successfully Treated with a Two-Stage Revision: A Case Report

CASE

We report the successful treatment of a Nocardia cyriacigeorgica periprosthetic joint infection (PJI) that occurred at the site of a total knee arthroplasty. To our knowledge, this organism has not previously been reported in the literature as a cause of PJI. Given the need for a prolonged duration of treatment for this organism (a minimum of 6 to 12 months), modifications to the standard 2-stage revision were made in consultation with infectious-disease specialists.

CONCLUSION

PJI is a devastating complication that leads to substantial patient morbidity and utilization of health-care resources. As the number of PJIs continues to rise, new and increasingly challenging infections are being encountered more frequently. In the case described here, the second stage of the revision was delayed for 6 months and antibiotics were continued for 7 months after the second operation, for a total of 13 months of antibiotic treatment. The present report provides a possible treatment plan for patients infected with durable bacteria similar to N. cyriacigeorgica.

Utility of postoperative radiography in routine primary total shoulder arthroplasty

BACKGROUND

The medical relevance and cost-benefit of routine radiographs after primary anatomic total shoulder arthroplasty (TSA) up to a year postoperatively are unknown. This study was performed to assess the medical relevance and cost-benefit of radiography after TSA during the first postoperative year.

METHODS

During the period 2010 to 2015, 160 consecutive patients undergoing anatomic TSA by a single fellowship-trained surgeon had radiographs obtained at 2 weeks, 6 weeks, 4 months, and 1 year postoperatively. Radiographs and clinic notes were assessed to determine if a change in postoperative care happened because of radiographic findings, including postoperative fracture, hardware complication, or any concerning radiographic feature. Cost data and amount billed were obtained.

RESULTS

Patients underwent radiography at 1.8 ± 0.2 weeks, 6.5 ± 1.2 weeks, 14.9 ± 2.9 weeks, and 46.8 ± 19.5 weeks postoperatively. Findings on the radiologist's reading were normal/unremarkable for 100.0%, 96.8%, 95.9%, and 95.2%, respectively, at each visit. Results were documented in the note for 92.5%, 97.4%, 98.0%, and 92.4%, respectively, at each visit. Review of the radiographs yielded no change in management based on these parameters. The amount billed for radiographs was $284,281 ($1776.76 per patient).

CONCLUSIONS

A lack of clinically meaningful impact from routine postoperative radiography does not justify the per-patient expense, as routine imaging did not cause a change in postoperative management. The available data suggest that routine radiographs after primary anatomic TSA may be unnecessary or perhaps the described frequency in which radiographs are obtained is in excess.

Patient-related risk factors for infection following knee arthroscopy: An analysis of over 700,000 patients from two large databases

BACKGROUND

To determine patient-related risk factors for infection following knee arthroscopy using two large databases.

METHODS

A private-payer (PP) and Medicare national insurance database were queried for patients undergoing simple knee arthroscopy procedures from 2005 to 2015. Patients undergoing concomitant open or complex procedures with grafts were excluded. Postoperative infection within 90days was assessed using ICD-9 and CPT codes. A multivariate logistic regression analysis was utilized to evaluate patient-related risk factors for postoperative infection. Adjusted odds ratios (OR) and 95% confidence intervals were calculated for each risk factor, with P <0.05 considered statistically significant.

RESULTS

One hundred thousand three hundred ninety nine patients from the PP database and 629,842 patients from the Medicare database met all inclusion and exclusion criteria. In the PP database, there were 250 patients with documented infections (0.25%); the incidence of infection was similar in the Medicare database (1755 patients, 0.28%). There were numerous patient-related comorbidities and demographics independently associated with a significantly increased risk of postoperative infection that were similar across the PP and Medicare patient populations, respectively, including younger age (OR=1.27, 1.43), morbid obesity (OR=1.26, 1.74), tobacco use (OR=1.34, 1.48), inflammatory arthritis (OR=1.61, 1.60), chronic kidney disease (OR=1.65, 1.14), hemodialysis (OR=1.93, 1.36), depression (OR=2.02, 1.73), and a hypercoagulable disorder (OR=2.76, 1.58).

CONCLUSION

The present study identified numerous patient-related risk factors independently associated with an increased risk of infection following knee arthroscopy in PP and Medicare-aged patients.

Limited utility of routine early postoperative radiography after primary ACL reconstruction

BACKGROUND

Given the overall success of anterior cruciate ligament (ACL) reconstruction and the infrequent occurrence of complications detectable on radiographs, the clinical utility and cost-effectiveness of routine radiographs in the early postoperative setting is questionable.

METHODS

Nine hundred thirty-three consecutive adult patients undergoing uncomplicated ACL reconstruction at a single institution were retrospectively reviewed to determine whether a postoperative knee radiograph was obtained within the first three months postoperatively. Images, reports and clinical notes were reviewed to determine if any clinical management change occurred due to x-ray findings. Radiograph charges, including imaging, technical and professional charges were calculated.

RESULTS

Five hundred ninety-nine of 933 primary ACL reconstruction patients (64.8%) had postoperative knee radiography at an average of 6.3±3.5 weeks postoperatively. A musculoskeletal radiologist read 97.7% of x-rays as normal. In the associated visit note, 70.3% of x-ray results were documented. Only 14.1% of patients with a postoperative x-ray had subsequent imaging. There were no significant management changes based on the routine postoperative radiographs using the defined criteria. A total of $336,683 ($562 per patient) was billed to patients for postoperative radiographs.

CONCLUSIONS

Routine early postoperative radiography after primary ACL reconstruction is of questionable utility. The significant per-patient expense is not balanced by the low yield of clinically meaningful data, as nearly all radiographs in the present series were normal and none resulted in significant changes in postoperative clinical management. These results suggest that routine radiographs after uncomplicated ACL reconstruction may be unnecessary although larger, multicenter studies are necessary to confirm these findings.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Arthroscopically Assisted Treatment of Navicular Osteochondral Defect Using Flowable Collagen, Iliac Crest Bone Marrow Aspirate and Fibrin Glue: A Case Report

A 32-year-old male recreational athlete presented with activity-related chronic dorsal midfoot pain. Conservative treatment, including a prolonged period of immobilization, physical therapy, nonsteroidal anti-inflammatory drugs, and use of a bone stimulator, failed to resolve his symptoms. Computed tomography and magnetic resonance imaging demonstrated a cystic appearing focus within the navicular in conjunction with a osteochondral lesion within the proximal articular surface of the navicular. This case report presents an arthroscopically assisted treatment of a navicular osteochondral lesion using curettage and backfilling with fibrin glue, flowable collagen, and autogenous bone grafting.

LEVELS OF EVIDENCE

Therapeutic, Level IV.

MRI for the evaluation of knee pain: comparison of ordering practices of primary care physicians and orthopaedic surgeons

BACKGROUND

Knee pain is one of the most common reasons for outpatient visits in the U.S. The great majority of such cases can be effectively evaluated through physical examination and judicious use of radiography. Despite this, an increasing number of magnetic resonance images (MRIs) of the knee are being ordered for patients with incomplete work-ups or for inappropriate indications. We hypothesized that MRIs ordered by orthopaedic providers were more likely to result in changes in diagnoses and/or plans for care than those ordered by non-orthopaedic providers.

METHODS

We reviewed the charts of all consecutive new patients seen at our orthopaedic outpatient office between January 1, 2010, and December 31, 2011, with International Classification of Diseases, Ninth Revision (ICD-9) codes for meniscal or unspecific sprains and strains of the knee. A total of 1592 patients met our inclusion criteria and were divided into two groups: those initially evaluated and referred by their primary care physician (PCP) (n = 747) and those initially evaluated by one of our staff orthopaedic surgeons (n = 845).

RESULTS

MRI-ordering rates were nearly identical between orthopaedic surgeons and PCPs (25.0% versus 24.8%; p = 0.945). MRIs ordered by orthopaedic surgeons, however, resulted in significantly more arthroscopic interventions than those ordered by PCPs (41.2% versus 31.4%; p = 0.042). Orthopaedic surgeons ordered MRIs for patients who were more likely to benefit from arthroscopic intervention, including patients who were younger (mean age, 45.1 years versus 56.5 years for those with PCP-ordered MRIs; p < 0.001), patients with acute symptoms (39.3% versus 22.2%; p < 0.001), and patients with a history of trauma (49.3% versus 36.2%; p = 0.019). Finally, orthopaedic surgeons were less likely than PCPs to order MRIs for patients with substantial osteoarthritis who subsequently underwent total knee arthroplasty (4.3% versus 9.2%; p = 0.048).

CONCLUSIONS

MRI utilization by orthopaedic surgeons results in more appropriate interventions for patients with symptoms and findings most amenable to surgical intervention.

Current concepts: mallet finger

Loss of the extensor mechanism at the distal interphalangeal (DIP) joint leads to mallet finger also known as baseball finger or drop finger. This can be secondary to tendon substance disruption or to a bony avulsion. Soft tissue mallet finger is the result of a rupture of the extensor tendon in Zone 1, and a bony mallet finger is the result of an avulsion of the extensor tendon from the distal phalanx with a small fragment of bone attached to the avulsed tendon. Mallet finger leads to an imbalance in the distribution of the extensor force between the proximal interphalangeal (PIP) and DIP joints. If left untreated, mallet finger leads to a swan neck deformity from PIP joint hyper extension and DIP joint flexion. Most mallet finger injuries can be managed non-surgically, but occasionally surgery is recommended for either an acute or a chronic mallet finger or for salvage of failed prior treatment.