The 2020 London International Hamstring Consensus meeting was convened to improve our understanding and treatment of hamstring injuries. The multidisciplinary consensus panel included 14 International specialists on the management of hamstring injuries. The Delphi consensus process consisted of two rounds of surveys which were completed by 19 surgeons from a total of 106 participants. Consensus on individual statements was regarded as over 70% agreement between panel members. The consensus group agreed that the indications for operative intervention included the following: gapping at the zone of injury (86.9%); high functional demands of the patient (86.7%); symptomatic displaced bony avulsions (74.7%); and proximal free tendon injuries with functional compromise refractory to non-operative treatment (71.4%). Panel members agreed that surgical intervention had the capacity to restore anatomy and function, while reducing the risk of injury recurrence (86.7%). The consensus group did not support the use of corticosteroids or endoscopic surgery without further evidence. These guidelines will help to further standardise the treatment of hamstring injuries and facilitate decision-making in the surgical treatment of these injuries.
Total hip replacement (THA) is among the most common and highest total spend elective operations in the United States. However, up to 7% of patients have 90-day complications after surgery, most frequently joint dislocation that is related to poor acetabular component positioning. These complications lead to patient morbidity and mortality, as well as significant cost to the health system. As such, surgeons and hospitals value navigation technology, but existing solutions including robotics and optical navigation are costly, time-consuming, and complex to learn, resulting in limited uptake globally. Augmented reality represents a navigation solution that is rapid, accurate, intuitive, easy to learn, and does not require large and costly equipment in the operating room. In addition to providing cutting edge technology to specialty orthopedic centers, augmented reality is a very attractive solution for lower volume and smaller operative settings such as ambulatory surgery centers that cannot justify purchases of large capital equipment navigation systems.Problem
Solution
Lumbar spine fusion in patients undergoing THA (total hip arthroplasty) is a known risk factor for hip dislocation with some studies showing a 400% increased incidence compared to the overall THA population. Reduced spine flexibility can effectively narrow the cup anteversion safe zone while alterations in pelvic tilt can alter the center of the anteversion safe zone. The use of precision cup alignment technology combined with patient-specific cup alignment goals based on preoperative assessment has been suggested as a method of addressing this problem. The current study assess the dislocation rate of THA patients with stiff or fused lumbar spines treated using surgical navigation with patient-specific cup orientation goals. Seventy-five THA were performed in 54 patients with a diagnosis of lumbar fusion, lumbar disc replacement, and scoliosis with Cobb angles greater than 40 degrees were treated by the senior author (SM) as part of a prospective, non-randomized study of surgical navigation in total hip arthroplasty. All patients were treated using a smart mechanical navigation tool for cup alignment (HipXpert System, Surgical Planning Associates, Inc., Boston, MA). Cup orientation goals were set on a patient-specific basis using supine pelvic tilt as measured using CT. Patients with increased pelvic tilt had a goal for increased cup anteversion and patients with decreased pelvic tilt had a goal for decreased cup anteversion (relative to the anterior pelvic plane coordinate system). Each patient's more recent outpatient records were assessed for history of dislocation, instability, mechanical symptoms, decreased range of motion or progressive pain. Additionally, last clinic radiographs were reviewed to confirm lumbar pathology in the form of spinal surgical hardware.Introduction
Methods
The effect of spine-pelvis position and motion on hip arthroplasty function has been increasingly appreciated in the past several years. Some authors have stressed the importance of using precision technologies for component placement while others have advocated the use of dual mobility articulations or large bearings and lateralized liners in patients with fused lumbar spines. The current study assesses the prevalence of stiff and fused spines in an elective total hip arthroplasty population. One hundred and forty-nine patients undergoing elective total hip arthroplasty were assessed preoperatively with CT (computed tomography) and functional radiographs for the purpose of CT based planning and intraoperative navigation of total hip arthroplasty (HipXpert System, Surgical Planning Associates, Inc., Boston, MA). The functional radiographs included standing and sitting lateral images (EOS Imaging, SA, Paris, France). Patients were assessed for supine, standing and sitting pelvic tilt (PT) and change in sacral slope (SS). Spine stiffness was defined by a change in sacral slope (SS) of less than or equal to 10 degrees on the standing to sitting lateral radiographs according to Luthringer et al JOA 2019.Introduction
Methods
The Superior Hip Approach allows for safe reconstruction of the hip while maximizing preservation of the surrounding soft tissues. The procedure involves an incision in the hip joint capsule posterior to the gluteus medius and minimus and anterior to the short external rotators. The technique involves preparation of the femur in-situ through the superior femoral neck and then excision of the femoral head, which avoids the attendant soft tissue dissection or injury associated with dislocation of the native hip. After component implantation, the capsule is closed anatomically. Two separate studies have demonstrated that over a 90-day period, patients whose hips were replaced using this technique consumed the least amount of cost of any patients treated by hip arthroplasty in the Commonwealth of Massachusetts. One study assessed all hips replaced in patients insured by Medicare over a four-year period. In this study, patients treated by the Superior Hip Approach were less costly by an average of more than $7,000 over 90 days. A second study assessed all hips replaced in patients insured by a large private insurer. This study showed again that patients treated by the Superior Hip Approach were the lowest cost patients. Notable, the cost on average was $23,500 less per procedure compared to the most well-known medical care organization in the state or roughly half the cost. Lower cost was due to both lower inpatient cost and reduced utilization of post-acute care resources. Since reduced resource utilization is a direct measure of accelerated recovery, these economic data combine with clinical outcomes and anatomical studies that document that the Superior Hip Approach is a reliable technique for achieving optimal results following THA.
In the United States, the Centers for Medicare and Medicaid Services consider rates of unplanned hospital readmissions to be indicators of provider quality. Understanding the common reasons for readmission following total joint arthroplasty will allow for improved standards of care and better outcomes for patients. The current study seeks to evaluate the rates, reasons, and Medicare costs for readmission after total hip and total knee arthroplasty. This study used the Limited Data Set (LDS) from the Centers for Medicare and Medicaid Services (CMS) to identify all primary, elective Total Knee Arthroplasties (TKA) and Total Hip Arthroplasties (THA) performed from January 2013 through June 2016. The data were limited to Diagnosis-Related Group (DRG) 470, which is comprised of major joint replacements without major complications or comorbidities. Readmissions were classified by corresponding DRG. Readmission rates, causes, and associated Medicare Part A payments were aggregated over a ninety-day post-discharge period for 804,448 TKA and 409,844 THA.INTRODUCTION
METHODS
Economic data, clinical outcome studies, and anatomical studies continue to support the Superior Hip Approach as a preferred approach for improved safety, maximal tissue preservation, rapid recovery, and minimised cost. Clinical studies show exceedingly low rates of all major complications including femur fracture, dislocation, and nerve injury. Economic data from Q1 2013 to Q2 2016 demonstrate that CMS-insured patients treated by the Superior Hip Approach have the lowest cost of all patients treated in Massachusetts by an average of more than $7,000 over 90 days. The data show that the patients treated by the Superior Hip Approach have lower cost than any other surgical technique. Matched-pair bioskills dissections demonstrate far better preservation of the hip joint capsule and short external rotators than the anterior approach. Design principles include: Preservation of the abductors; Preservation of the posterior capsule and short external rotators; Preparation of the femur in situ prior to femoral neck osteotomy; Excision of the femoral head, thereby avoiding surgical dislocation of the hip; In-line access to the femoral shaft axis; Ability to perform a trial reduction; Independence from intra-operative imaging; Independence from a traction table; Applicable to at least 99% of THA procedures. In contrast to the results of the Superior Approach, the anterior approach continues to show difficulties with wound problems, infection, intra- and post-operative fracture, and failure of femoral component osseointegration and even dislocation. Evidence continues to demonstrate that the Superior Hip Approach has advantages over all other surgical approaches to the hip.Conclusion
Knowledge-based total hip arthroplasty is becoming increasingly recognised for improved safety, efficiency, and accuracy. Pre-operative knowledge of native and planned femoral anteversion, the exact size of implants, neck length and offset, and head lengths can serve to safely accelerate surgery and reduce the need for intra-operative imaging. Pre-operative knowledge of the effect on change in leg length and offset effected by specific implant combinations can serve to minimise undesired changes. The use of a smart mechanical navigation tool superimposed on this knowledge, can serve to easily and swiftly achieve optimal component position. Economic data from Q1 2013 to Q2 2016 demonstrate that CMS-insured patients treated by knowledge-based surgery using the HipXpert mechanical navigation system combined with the superior hip approach have the lowest cost of all patients treated in Massachusetts by an average of more than $7,000 over 90 days for Medicare Part A expenditure (HipXpert System, Surgical Planning Associates, Boston, MA). The data show that these combined techniques outpace all other technology/technique combinations including robotics.Pre-operative knowledge
Cost savings
Interest in tissue-preserving or minimally invasive total hip arthroplasty (THA) is increasing with focus toward decreased hospital stay, enhanced rehabilitation, and quicker recovery for patients. Two tissue-preserving techniques, the anterior and superior approaches to THA, have excellent clinical results, but little is known about their relative impact on soft tissue. The purpose of this study was to evaluate the type and extent of tissue damage after THA with each approach, focusing on abductors, short external rotators, and the hip capsule. Total hip arthroplasty was performed on bilateral hips of eleven fresh-frozen cadavers (22 hips). They were randomized to anterior THA performed on one side and superior THA performed on the other, in the senior authors' standard technique. Two independent examiners graded the location and extent of tissue injury by performing postsurgical dissections. Muscle bellies, tendons, and capsular attachments were graded as intact, split, damaged (insignificant, minimal, moderate, or extensive damage), or detached based on direct visual inspection of each structure. Tissue injury was analyzed with either a chi-squared (≥5 qualifying structures) or Fisher's exact test (<5 qualifying structures). P values <0.05 were significant.INTRODUCTION
METHODS
Goals for total hip arthroplasty include acceleration of recovery, optimisation of component placement, minimisation of peri-operative complications, and maximal preservation of surrounding soft tissues. Achieving these goals when combined with appropriate implant design and manufacture can lead to decades of excellent hip function. With the exception of relatively rapid recovery, which can also be achieved with virtually all modern surgical exposures, the anterior hip approach fails to reliably achieve these goals. Problems with the anterior exposure for total hip arthroplasty are becoming increasingly recognised. Complications with equal or higher incidences than alternative exposures include: 1.) Early wound complications, 2.) Infection, 3.) Intra-operative and post-operative femur fracture, 4.) Greater trochanteric fracture, 5.) Dislocation, 6.) Femoral component loosening, 7.) Poor component placement, 8.) Poor soft tissue balance, 9.) Incisions with poor aesthetics and associated superficial hypaesthesia and dysaesthesia. These complications may be in part due to: 1.) The anterior and posterior soft tissue releases often necessary to complete the exposure, 2.) Poor ability to anatomically repair the hip joint capsule, 3.) Reduced choices of femoral components with restriction generally to those with less robust fixation, 4.) The poorly extensile nature of the interval, 5.) The need to place the incision in the region of the flexion crease, 6.) The limited ability to assess soft tissue balance and impingement-free range of motion at the time of surgery, 7.) The undue reliance on unvalidated, inaccurate imaging techniques to assess component placement. While experienced surgeons can achieve excellent results with the anterior (or virtually any other) exposure for total hip arthroplasty, the anterior exposure is by no means close to being a first among equals.
Excellent outcomes following total hip arthroplasty require both optimal soft-tissue management and precise planning and placement of prosthetic components. The use of detailed and dynamic three-dimensional surgical plans combined with smart mechanical instruments for component placement facilitates precise and efficient surgery. Interest in these technologies has increased recently as surgeons and institutions are now responsible for poor outcomes in a growing percentage of the patient population. Cloud-based, patient-specific planning allows the surgeon to review and refine and execute surgical plans efficiently (HipXpert System, Surgical Planning Associates, Boston, MA). The surgical plans include cup size, cup orientation, stem size, head length, femoral anteversion, and planned change in leg length and offset, all in relation to the patients bony anatomy in 3D and multiplanar views. The associated smart tool is adjusted specifically for that patient and when docked, provides orientation information to the surgeon. The system has been proven to be robust, with repeated studies showing accurate cup placement in 100% of cases including by an independent study. This compares to a recent study of robotic methods that 88% of inclination and 84% for anteversion and to even greater inaccuracy of conventional surgery. Cloud-based 3D planning combined with smart mechanical navigation of cup placement offers the optimum combination of accuracy, speed, and simplicity for solving the ubiquitous problems of component sizing, orientation, and version, offset, and leg length correction. Knowledge of component sizing pre-operatively can facility inventory management and allows the surgery team to better anticipate the surgeon's goals during the procedure.
The high and ever increasing cost of medical care worldwide has driven a trend toward new payment models. Event based models (such as bundled payment for surgical events) have shown a greater potential for care and cost improvement than population-based models (such as accountable care organizations). Since joint replacement is among the most frequent and costly surgical events in medicine, bundled payments for joint replacement episodes have been at the forefront of evolution from fee-for-service to value-based care models and episode-based healthcare reform in general. Our education as surgeons in medical school, residency, fellowship, and in continuing education has been almost entirely non-economic in focus. Yet, we surgeons are now evolving from being primarily responsive for our patients' medical care to being also responsible for all expenditures associated with our patients' care. Similarly, while the cost of our patients' care was not even available to us, every dollar of expenditure for a patient's episode of care is now available to us in some circumstances. For example, a typical primary joint replacement episode may cost $30,000 for a patient insured by Medicare in the US. A surgeon performing 400 joint replacements per year is therefore authorizing upwards of $12M a year in health care spending by making the decisions to perform reconstructive procedures on those patients. The risk for value-based surgical episodes of care can be born by various entities including hospital systems or the surgeons themselves. Recent evidence demonstrates that quality improves and cost decreases more rapidly when surgeons take primary responsibility and risk for episodes of care as compared to when a hospital system or third party takes primary responsibility and risk. Yet, as surgeons, our education in the field of medical economics, value-based episodes of care, and payment reform is only just beginning. The more we understand about the cost and value of the services that we order for our patients, the more leadership can provide as healthcare evolves. The current presentation will describe the specific cost of care for the primary joint replacement patient preliminary experience with accepting risk and responsibility for these patients. It is likely that our patients will be best served if we surgeons provide as much leadership as possible in their care, both medically and economically.
Distal neck modularity places a modular connection at a mechanically critical location, which is also the location that confers perhaps the greatest clinical utility. The benefits of increased clinical options at that location must be weighed against the potential risks of adding an additional junction to the construct. Those risks include prosthetic neck fracture, taper corrosion, metal hypersensitivity, and adverse local tissue reaction. Further, in-vitro testing of ultimate or fatigue strength of femoral component designs has repeatedly failed to predict behavior in-vivo, raising questions about the utility of in-vitro testing that does not incorporate the effect of mechanically assisted crevice corrosion into the test design. The material properties of Ti alloy and CoCr alloy place limits on design considerations in the proximal femur. The smaller taper junctions that are necessary for primary reconstruction are particularly vulnerable to failure whereas larger taper junctions commonly used in revision modular femoral component designs have greater opportunity for success. Modular junctions of CoCr alloy on conventional Ti alloy have been shown to have a greater incidence of clinically significant mechanically assisted crevice corrosion and adverse reaction. Designs that have proven clinical strength and utility universally have larger, more robust junctions, that extend into the metaphysis of the femur. While these designs are primarily designed for revision total hip replacement (THR), they are occasionally indicated for primary THR. Overall, however, while design options at the neck-stem junction have unmatched clinical utility, no design that does not extend into the metaphysis has proven to be universally reliable. While routine use of modular neck components for primary THR does not appear to be clinically indicated based on current evidence, modular designs with proven successful proximal junctions appear to be indicated for revision THR and rare primary THR with extreme version or other anatomical circumstances.
Bundled budgeting of payments for joint replacement services has become increasing common in an effort to improve quality while lowering cost. In the US, some Medicare bundled payment programs are voluntary whereas some now are mandatory. Large medical care and medical management organizations have largely been assigned or seized control of management of these programs, leaving the surgeon in a subordinate role. The current abstract describes an experience where surgeons provide leadership and accept responsibility in bundled payment program. We engaged a collective of 16 different private company orthopedic physician groups to apply to become episode initiators under under the Medicare Bundled Payment for Care Improvement (BPCI) models 2 and 3. The application process itself provided historical cost data, enabling each group to independently decide whether or not to proceed with the BPCI.Introduction
Methods
While total hip arthroplasty is considered to be one of the most cost-effective medical interventions, the total cost of care for a population patients treated by THR can present a significant burden on the payer, whether it be an employer, private insurer or government. Data on the true cost of care has rarely been made available to the treating physician. Such lack of information makes comprehensive management difficult. Bundled payment models of care require knowledge of all costs associated with the care of our patients and opens new opportunity for analysis to improve management and outcomes. The current study assess the influence of surgical technique on total cost of care for total hip arthroplasty. Payment data for 341 patients who underwent total hip arthroplasty at a single institution from June 1st, 2011 to October 31st, 2014 were analyzed. Each procedure was performed using either the superior, anterior, or posterior exposure. The superior exposure was performed with femoral head excision and without dislocation of the hip. The data were analyzed for total cost, inpatient cost, inpatient physician cost, readmission cost, skilled nursing facility cost, and home healthcare agency cost among the different approaches.Introduction
Methods
Ideal treatment of displaced femoral neck fragility fractures in the previously ambulatory patient remains controversial. Treating these patients with total hip arthroplasty has improved patient reported outcomes and reduced rates of revision surgery compared to those treated with hemiarthroplasty. However, possible increased risk of dislocation remains a concern with total hip arthroplasty. The anterolateral and direct anterior approaches to total hip replacement have been applied in the femoral neck fracture population to minimize dislocation rates. However, the anterolateral approach has been associated with abductor injury and increased rates of heterotopic ossification while the anterior approach has been associated with peri-prosthetic femur fracture, lateral femoral cutaneous nerve injury, and wound complications. The Supercapsular Percutaneously Assisted (SuperPATH) approach was developed to minimize disruption of the capsule and short-external rotators in an effort to reduce the risk of dislocation and assist in quicker recovery in the elective hip arthroplasty setting. To achieve this, the SuperPATH technique allows the femur to be prepared in situ and the acetabulum to be reamed percutaneously once the femoral head is removed. This study investigates the post-operative time to ambulation, length of stay, discharge destination, and early dislocation rate of previously ambulatory patients with a displaced femoral neck fragility fracture that were treated with a total hip arthroplasty via the SuperPATH technique. A retrospective chart review was performed of previously ambulatory patients consecutively treated for a displaced femoral neck fragility fracture with a total hip replacement using the SuperPATH technique. Thirty-five patients were included in the study and examined for demographic data, time to ambulation, length of stay, major and minor complications during their hospital stay. Phone interviews were conducted to check for dislocation events.BACKGROUND
METHODS
Cup malpositioning remains a common cause of dislocation, wear, osteolysis, and revision. The concept of a “Safe Zone” for acetabular component orientation was introduced more than 35 years ago1. The current study assesses CT studies of replaced hips to assess the concept of a safe zone for acetabular orientation by comparing the orientation of acetabular components revised due to recurrent instability and to a series of stable hip replacements. Cup orientation in 21 hips revised for recurrent instability was measured using CT. These hips were compared to a group of 115 stable hips measured using the same methods. Femoral anteversion in the stable hips was also measured. Images to assess femoral anteversion in the unstable group were not available. An application specific software modules was developed to measure cup orientation using CT (HipSextant Research Application 1.0.13 Surgical Planning Associates Inc., Boston, Massachusetts). The cup orientation was determined by first identifying Anterior Pelvic Plane Coordinate system landmarks on a 3D surface model. A multiplanar reconstruction module then allowed for the creation of a plane parallel with the opening plane of the acetabulum. The orientation of the cup opening plane in the AP Plane coordinate space was calculated according to Murray's definitions of operative anteversion and operative inclination2. Both absolute cup position relative to the APP and tilt-adjusted cup position3 were calculated.Introduction
Methods
Navigation of acetabular component orientation is still not commonly performed despite repeated studies that show that more than ½ of acetabular components placed during hip arthroplasty are significantly malpositioned1. The current study uses postoperative CT to assess the accuracy of a smart mechanical navigation instrument system for cup alignment. Thirty seven hip replacements performed using a smart mechanical navigation device (the HipXpert System) had post-operative CT studies available for analysis. These post-operative CT studies were performed for pre-operative planning of the contralateral side, one to three years following the prior surgery. An application specific software module was developed to measure cup orientation using CT (HipXpert Research Application, Surgical Planning Associates Inc., Boston, Massachusetts). The method involves creation of a 3D surface model from the CT data and then determination of an Anterior Pelvic Plane coordinate system. A multiplaner image viewer module is then used to create an image through the CT dataset that is coincident with the opening plane of the acetabular component. Points in this plane are input and then the orientation of the cup is calculated relative to the AP Plane coordinate space according to Murray's definitions of operative anteversion and operative inclination. The actual cup orientation was then compared to the goal of cup orientation recorded when the surgery was performed using the system for acetabular component alignment.Introduction
Patients and Methods
Patients less than 60 years old have been reported to have a higher risk of revision following total hip arthroplasty (THA) than older patient cohorts, possibly to due higher activity, a higher incidence of deformity and greater probability of prior surgery. Ceramic-on-ceramic bearing surfaces have been proposed for use in young and active individuals due to their low wear, low risk of adverse biologic reaction, and long-term survivorship. We assessed the clinical results and long-term survivorship of uncemented ceramic-on-ceramic THA in a young patient population. For the six year period from May 1999 to March 2005, 278 hip replacements in 244 patients less than 60 yeas of age at the time of surgery were performed using alumina ceramic-ceramic bearings. All hips had uncemented titanium femoral and acetabular components. The ceramic liner was fixed to the shell with an 18-degree flush-mounted taper design. Patients were followed clinically and radiographically. Attempts were made to contact all patients who had not been seen in the prior 3 years. Of the 278 hips, 17 hips (16 patients) remain lost to follow-up, leaving 261 hips (228 patients; 155 hips in men, 106 hips in women) for assessment. Mean age of the patients was 46.2 years at the time of surgery (range 17.8 to 59.9 years). 17% of hips had at least one previous hip surgery. Mean time following surgery was 9.75 years (range 2 to 16.8 years).INTRODUCTION
METHODS
Distal neck modularity places a modular connection at a mechanically critical location which is also the location that confers perhaps the greatest clinical utility. Assessment of femoral anteversion in 342 of our total hip replacement (THR) patients by CT showed a range from −24 to 61 degrees. The use of monoblock stems in some of these deformed femurs therefore must result in a failure to appropriately reconstruct the hip and have increased risks of impingement, instability, accelerated bearing wear or fracture, and adverse local tissue reaction (ALTR). However, the risks of failing to properly reconstruct the hip without neck modularity must be weighed against the additional risks introduced by neck modularity. There are several critical design, material, and technique variables that are directly associated with higher or lower incidences of problems associated with modular neck femoral components. Unfortunately, in vitro testing of the fatigue strength of these constructs has failed to predict their behavior in vivo. Designs predicted to tolerate loads that far exceed those experienced in vivo still fail at unacceptably high rates. Titanium alloy neck components subjected to the stresses at the neck-stem junction continue to fail at an unacceptable incidence. CoCr alloy neck components, while theoretically stronger, still fracture and are further compromised by mechanically assisted crevice corrosion, metal hypersensitivity, and rarely, adverse tissue reaction. Designs that have proven clinical strength and utility universally have larger, more robust junctions that extend into the metaphysis of the femur. While these designs are primarily designed for revision THR, they are occasionally indicated for primary THR. Overall, however, while design options at the neck-stem junction have unmatched clinical utility, no design that does not extend into the metaphysis has proven to be universally reliable. While routine use for primary THR does not appear clinically indicated based on current evidence, modular designs with proven successful proximal junctions appear to be indicated for extreme version or anatomical circumstances.
