Gele Moloney

What does it take to have a high-grade pivot shift?

AbstractThe pivot shift is the most specific clinical test to assess pathological knee joint rotatory laxity following ACL injury. This article attempts to describe the anatomic structures responsible for creating a high-grade pivot shift and their potential role in customizing ACL reconstruction. A review of the literature demonstrates that disruption of the secondary stabilizers of anterior translation of the lateral compartment including the lateral meniscus, anterolateral capsule, and IT band contributes to a high-grade pivot shift in the ACL-deficient knee. The morphology of the lateral tibial plateau, including increased posteroinferior tibial slope and small size, can also contribute to high-grade pivot shift. Factors that may decrease the grade of the pivot shift include medial compartment injury, MCL injury, patient guarding, and osteoarthritis. In conclusion, a high-grade pivot shift in the ACL-deficient knee is often associated with incompetence of the lateral soft tissue envelope. Rotatory laxity as assessed by the pivot shift may also be falsely underestimated by concomitant injuries. Level of evidence IV.

Treatment of periprosthetic femur fractures around a well-fixed hip arthroplasty implant: span the whole bone

IntroductionPeriprosthetic femur fractures are a growing problem in the geriatric population. This study examines Vancouver B1 periprosthetic femur fractures treated with open reduction internal fixation using a laterally based plate. Outcomes using plates which spanned the length of the femur to the level of the femoral condyles were compared to those which did not. The hypothesis was that spanning internal fixation would result in a decreased rate of refracture and subsequent reoperation.Materials and methodsPatients admitted to three affiliated academic hospitals treated with open reduction internal fixation for a periprosthetic femur fracture in the setting of a preexisting total hip arthroplasty or hemiarthroplasty stem were identified. Patient data were reviewed for age, gender, fracture classification, operative intervention, time to union, as well as complications related to treatment and need for further surgery.ResultsOver a 5-year period, 58 patients were treated with open reduction internal fixation using a laterally based plate for Vancouver B1 femur fractures. Twenty-one patients were treated with plates that extended to the level of the femoral condyles. In that group there were no nonunions or subsequent periprosthetic fractures reported. Of 36 patients treated with short plates, 3 went on to nonunion resulting in plate failure and refracture and 2 sustained a subsequent fracture distal to the existing fixation.ConclusionsIn this series, fixation for periprosthetic femur fractures around a well-fixed arthroplasty stem which spans the length of the femur to the level of the femoral condyles is associated with a decreased rate of nonunion and refracture. By decreasing the rate of refracture and nonunion, spanning fixation decreases the morbidity and mortality associated with additional surgery in a fragile geriatric population.

Use of a Fluoroscopic Overlay to Assist Arthroscopic Anterior Cruciate Ligament Reconstruction

Background: A growing body of evidence supports the importance of anatomic tunnel positioning in the success of anterior cruciate ligament (ACL) reconstruction, which stimulates the need for technologies to aid surgeons in achieving accurate anatomic tunnel placement. Intraoperative fluoroscopy is potentially one such technology, while its efficacy and usability have yet to be established. Purpose: To investigate the performance of an intraoperative fluoroscopic overlay in guiding tunnel placement during ACL reconstruction. Study Design: Controlled laboratory study. Methods: Twenty cadaveric knees underwent computed tomography (CT) scans and arthroscopic digitization of ACL insertion sites. The outlines of the digitized insertion sites were mapped to the corresponding CT-acquired bone models through a co-registration procedure. Twenty orthopaedic surgeons performed simulated ACL reconstructions, each on a randomly assigned cadaveric knee, first without and then with the aid of a fluoroscopic overlay system. The overlay system displayed on a lateral fluoroscopic image targets points representing the locations of the ACL insertion sites estimated from the literature data. Surgeons were allowed to adjust their tunnel positions under the guidance of the fluoroscopic image. Their initial, intermediate, and final positions were documented and compared with the target points as well as the native insertion sites. Results: Surgeons demonstrated significant (P < .01) improvements in femoral and tibial tunnel placements relative to the target points from an average distance of 3.9 mm to 1.6 mm on the femur and 2.1 mm to 0.9 mm on the tibia. The improvements toward the knee-specific actual insertion sites were significant on the tibial side but not on the femoral side. Conclusion: Surgeons can be successfully guided with fluoroscopy to create more consistent femoral and tibial tunnels during ACL reconstruction. More research is warranted to develop better population representations of the locations of natural insertion sites. Clinical Relevance: Intraoperative fluoroscopy can be an effective, easy, and safe method for improving tunnel positioning during ACL reconstruction.

Geriatric distal femur fracture: Are we underestimating the rate of local and systemic complications?

BACKGROUND Low energy distal femur fractures often occur in a fragile elderly population that is prone to local and systemic complications following operative treatment of extremity fractures. The nonunion rate and early complication rate following laterally based locked plating in this specific fracture are not well described. METHODS We conducted a retrospective cohort study conducted at three affiliated tertiary care hospitals to evaluate nonunion, early post operative complications, discharge disposition, length of stay, and mortality in patients over 60 years old undergoing laterally based locked plating of a low energy distal femur fracture. RESULTS Forty-four out of 176 patients were deceased at one year (25%). Predictors of one year mortality included older age, higher Charlson Comorbidity Index (CCI), and delay to surgery greater than 2days (p<0.001). Of 99 patients alive and with follow up at one year, 24 (24%) developed a nonunion and 21 of 24 required nonunion surgery. Development of a surgical site infection was statistically significantly correlated with development of nonunion. Age and CCI did not predict development of nonunion. Average length of stay was 10days and 82% of patients were discharged to a skilled nursing facility. Thirty eight percent of patients experienced at least one postoperative systemic complication. CONCLUSIONS Laterally based locked plating of the low energy geriatric distal femur fracture is most often followed by a tumultuous post-operative course with a high rate of local and systemic complications including death, nonunion, and extended hospital stays. LEVEL OF EVIDENCE Level III prognostic.

Equivalent mortality and complication rates following periprosthetic distal femur fractures managed with either lateral locked plating or a distal femoral replacement

INTRODUCTION Management of distal femur fractures above total knee arthroplasty (TKA) remains challenging. Two common surgical options are locked lateral plating (LLP) and distal femoral arthroplasty (DFR). Unfortunately, approximately 30-50% of patients may die within one year of injury, require further surgery, or not regain prior mobility performance. We compared 87 LLP to 53 DFR patients - to our knowledge the largest comparative study - focusing on 90- and 365-day mortality, mobility maintenance, and further surgery. METHODS We performed a retrospective review of patients at least 55 years old who sustained femur fractures near a primary TKA (essentially OTA-33 or Su types 1, 2, or 3) from 2000 to 2015 assigning cohort based on treatment: LLP or DFR. We excluded patients having prior care for the injury, whose surgery was not for fracture (e.g. loosening), or having other surgical intervention (e.g. intramedullary nail). RESULTS Results Cohorts were similar based on body mass index and age adjusted Charlson Comorbidity Index (aaCCI). LLP was more common than DFR for fractures above and at the level of the implant, but similar for fractures within the implant for patients with aaCCI ≥ 5. LLP and DFR had similar mortality at 90 days (9% vs 4%) and 365 days (22% vs 10%), need for additional surgery (9% vs 3%), and survivors maintaining ambulation (77% vs 81%). Patients whose surgery occurred 3 or more days after presentation had similar mortality risk to those whose surgery was before 3days. The mean age of one year survivors was 77 whereas for patients who died it was 85. Neither surgical choice nor aaCCI was associated with increased risk in time to surgery. CONCLUSIONS Fracture location, remaining bone stock, and patients prior mobility and current comorbidities must guide treatment. Our study suggests that 90- and 365-day mortality, final mobility, and re-operation rate are not statistically different with LLP vs DFR management.

Use of a Fluoroscopic Overlay to Guide Femoral Tunnel Placement During Posterior Cruciate Ligament Reconstruction

Background: Intraoperative recognition of the local anatomy of the posterior cruciate ligament (PCL) is difficult for many surgeons, and correct positioning of the graft can be challenging. Purpose: To investigate the efficacy of an overlay system based on fluoroscopic landmarks in guiding femoral tunnel placement during PCL reconstruction. Study Design: Controlled laboratory study. Methods: Twenty cadaveric knees were arthroscopically prepared, and their PCL femoral insertion sites were digitized. The digitized images were co-registered to computed tomography–acquired 3-dimensional bone models. Twenty surgeons with diverse backgrounds performed simulated arthroscopic reconstruction of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, first without and then with the aid of a lateral fluoroscopic image on which the position of a target insertion site based on literature data was displayed as an overlay. The surgeons were allowed to adjust tunnel placement in accordance with the displayed target position. A 3-way comparison was made of the tunnel positions placed by the surgeons, the native insertion site positions, and the literature-based positions. Results: The overlay system was effective in helping surgeons to improve femoral tunnel placement toward the target and toward the anatomic insertion site (P < .05). For femoral AL tunnel placement, surgeons needed 2.35 ± 2.21 extra attempts, which added an extra 80.00 ± 67.95 seconds to the procedure. For PM tunnel placement, surgeons needed 1.80 ± 1.88 extra attempts, adding 66.00 ± 70.82 seconds to the simulated surgery. In their first attempts, more than half of the surgeons positioned either the AL or PM femoral tunnel >5 mm from the native insertion site. With the use of the overlay, 70% of the surgeons were <5 mm away from the PM and 75% from the AL native insertion site. Conclusion: The use of a fluoroscopic overlay to guide intraoperative placement of the femoral tunnel(s) during PCL reconstruction can result in more anatomic reconstructions and therefore assist in re-creating native knee kinematics after PCL reconstruction. Clinical Relevance: Intraoperative fluoroscopy is an effective, easy, and safe method for improving femoral tunnel positioning during PCL reconstruction.

Efficacy of an Intra-Operative Imaging Software System for Anatomic Anterior Cruciate Ligament Reconstruction Surgery

An imaging software system was studied for improving the performance of anatomic anterior cruciate ligament (ACL) reconstruction which requires identifying ACL insertion sites for bone tunnel placement. This software predicts and displays the insertion sites based on the literature data and patient-specific bony landmarks. Twenty orthopaedic surgeons performed simulated arthroscopic ACL surgeries on 20 knee specimens, first without and then with the visual guidance by fluoroscopic imaging, and their tunnel entry positions were recorded. The native ACL insertion morphologies of individual specimens were quantified in relation to CT-based bone models and then used to evaluate the software-generated insertion locations. Results suggested that the system was effective in leading surgeons to predetermined locations while the application of averaged insertion morphological information in individual surgeries can be susceptible to inaccuracy and uncertainty. Implications on challenges associated with developing engineering solutions to aid in re-creating or recognizing anatomy in surgical care delivery are discussed.

Joint space height correlates with arthroscopic grading of wrist arthritis

BackgroundOsteoarthritis of the radiocarpal joints is commonly encountered by hand surgeons. To date, there is no well-defined method of radiographically grading osteoarthritis of the wrist.MethodsPreoperative radiographs of 48 patients undergoing wrist arthroscopy were evaluated retrospectively. Images were graded subjectively by five surgeons based on overall severity of arthritis, osteophytes, subchondral cysts, and subchondral sclerosis. The joint space height (JSH) ratio was calculated by measuring the space of the mid-radioscaphoid and mid-radiolunate joints and dividing each by the height of the capitate. Arthroscopic grading of arthritis was obtained from operative records and compared to subjective and objective grades. ANOVA testing evaluated for statistical significance with p < 0.05. Inter-rater and intra-rater reliability was determined using Pearson’s correlation analysis and Cohen’s kappa coefficient.ResultsObjective measurement using the JSH ratio demonstrated a significant decrease as arthroscopic arthritis grade increased for both radioscaphoid and radiolunate joints. Subjective grading of radioscaphoid and radiolunate joints was able to detect moderate/severe, but not mild arthritis. Subjective grading underestimated the degree of arthritis, particularly in the radiolunate joint. Inter-rater reliability was better for objective compared to subjective grading.ConclusionsSubjective grading of wrist arthritis can detect moderate/severe radiocarpal arthritis but poorly evaluates early arthritis and underestimates severity. Objective grading using the JSH ratio accurately grades radioscaphoid arthritis and detects early radiolunate arthritis. The JSH ratio more accurately assesses radiocarpal arthritis compared with subjective grading. As there currently is no accepted method to radiographically grade wrist arthritis, the JSH ratio represents a promising option.