Recent studies indicate the benefits of total hip arthroplasty (THA) by using femoral neck-preserving short-stem implants (March et al 1999). These benefits rely on the preservation of native hip structure and improved physiological loading. However, further investigation is needed to compare the outcome of these implants versus the conventional neck-sacrificing stems particularly assessed by patient-reported outcomes (PROs). In this study, we have investigated the differences in PROs between a neck-sacrificing stem design and neck-preserving short stem design (MiniHip, Corin Inc.). We hypothesized higher PROs outcome in patients who received treatment by using neck-preserving implants. In this study, we retrospectively analyzed the pre and post-operative PROs of patients receiving THA treatment by using neck-sacrificing implant (n=90, age 57±7.9 years) and a matched (BMI, age) cohort group of neck-preserving patients (n=105, age 55.16±9.88 years). Hip disability and Osteoarthritis Outcome Scores (HOOS) were using with the follow-up of similar follow up of 412.76 ± 206.98 days (neck sacrificing implant) and 454.63 ± 226.99 days (Neck-Preserving). Multivariate analysis of variance and Mann-Whitney tests were conducted for statistical analyses. Holm-Bonferroni adjusted for multiple comparisons was used with initial significance level of 0.05.Background
Methods
Total Hip Arthroplasty (THA) has long been the standard treatment for cases in which non-surgical alternatives have failed to improve pain and function in hip osteoarthritis (OA) patients. Outcomes from THA have improved over time with better surgical techniques and improved implant designs. While conventional neck-sacrificing implants have been associated with favorable outcomes, there is evidence to suggest biomechanical advantages of newer, femoral neck-preserving short-stem implants, including the Corin MiniHip. However, there is a still a gap of knowledge regarding the potential benefits of the MiniHip stem over conventional neck-sacrificing stems in regards to patient-reported outcomes (PROs). In this study, we investigated the differences between a neck-sacrificing stem design and neck-preserving short-stem design (MiniHip, Corin Inc.) arthroplasty concerning PROs, and considering the known features of the short stem design, we hypothesized that MiniHip THA would be associated with improved PROs in comparison to a neck-sacrificing implant system. We further sought to investigate gender effects related to MiniHip or conventional stem surgery. Neck-sacrificing implant patients (n=90, age 57±7.9 years, female=58, male=32) and a matched (matching criteria: follow-up period, BMI, age) cohort group of MiniHip patients (n=105, age 55.16±9.88 years, female: 25, male: 80) reported both pre-operative and post-operative Hip disability and Osteoarthritis Outcome Scores (HOOS) at a minimum interval of 6 months post-operatively and up to three years postoperatively. We applied MANCOVA analysis to compare patient-reported outcome subscores from each group using follow-up period as a covariate and employing gender as an additional grouping factor to evaluate gender effects. Statistical significance was set at α=0.05 and Bonferroni corrections were applied to account for multiple comparisons.Background
Methods
The number of hip arthroplasty procedures has steadily increased in the United States over the last decade [Wolford, et. al, 2015]. This trend will continue as this treatment is the most effective approach in relieving pain, improving mobility, reducing fall risk and improving the quality of life in patients with end-stage osteoarthritis. The effectiveness of recovery can be impacted by factors such as access to postoperative physical therapy regimens. During the recovery period, it is important for therapists to be guided in their therapeutic decision making by accurate data concerning the patient's performance on a variety of measures. This project is designed to map the gait recovery curves of individuals who have undergone unilateral hip arthroplasty. To date, eight individuals (4 females, mean age 64.9, SD 11.1) have participated in the study. Five of the patients were treated by traditional press-fit Accolade II implants (Stryker, Mahwah, NJ USA) through a direct anterior approach THA and the other three has been treated by using DAA THA and using neck preserving MinihipTM short stem implant (Corin Ltd., Cirencester, UK). Each participant walked on an instrumented treadmill as a self-selected speed for three minutes pre-surgery. Post-surgery data collections occurred at three and six weeks, and three and six months and employed the same treadmill speed as used prior to surgery. Bilateral lower limb kinematic data was collected with a 12 camera motion capture system Vicon® (Oxford Metrics, Oxford, UK) using reflective markers attached to the hip, knee, ankle, heel and toe. Force plates embedded in the treadmill provided kinetic data that aided in the detection of heel strike and toe off. The temporal features associated with gait, including stride, stance time and double support time were obtained for both the surgical and non-surgical limbs and were used to assess changes in performance during the recovery period. The stance and double support data were also converted to a percentage of stance values which provide additional insights into gait control strategies. Repeated measure MANOVAs were used to evaluate any potential differences in the variables either between limbs or over time. Results from the statistical testing revealed that there were no significant differences between the two limbs for either stride or stance time. This was expected since global asymmetrical gait would have led to the participants veer off of the treadmill. There was a main effect of ‘Time’ for both stride and stance times. Post hoc testing indicated that the 6-month post-surgery measures were significantly reduced when compared to the Pre-surgery and 3-week post-surgery measures. Similarly, there were no significant differences in double support times between the two legs but there was a main effect for time. Post hoc testing revealed that the 6-month post-surgery double support time was significantly less than the Pre-surgery and 3-week post-surgery measures. These significant changes clearly indicate that surgery is effective in improving gait parameters. Moreover, clinicians may want to consider assessing double support time as this measure is a particularly robust indicator of the effectiveness of unilateral hip arthroplasty.
Hip arthroplasty is commonly used as the final treatment approach for patients experiencing end-stage osteoarthritis. The number of these patients needing this treatment is expected to grow significantly by year 2030 to more than 572000 patients [Kurtz et al., 2007]. One of the important outcomes of hip arthroplasty is to improve patients' functions postoperatively. The evaluation of walking can provide a wealth of information regarding the efficiency of this treatment in improving a patient's mobility. Assessing the kinematic features of gait collected with a motion capture system combined with the aid of a motor-driven treadmill provides the advantage of enabling the evaluator to collect precise information about a large number of strides in a short period of time. Body segment kinematics (i.e. joint motion) are most often represented in the form of time series data with the abscissa (X axis) representing time and the ordinate (y axis) representing the motion of a particular joint. Although a great deal of information can be gained from the analyses of time series data, non-linear analyses tools can provide an additional and important dimension to a clinician's assessment of gait recovery. In this study eight patients (4 females, mean age 64.9, SD 11.1) have currently been assessed after unilateral hip arthroplasty. All surgeries were conducted by direct anterior approach by using two different approaches; three of the patients were treated by bone preservation technique and received Minihip short stem implant (Corin Ltd., Cirencester, UK) and five were treated by using a press fit stem implant Accolade II (Stryker, Mahwah, NJ USA). Patients performed a single three-minute trial of walking on a motor-driven treadmill at a self-selected pace. Using a 12 camera system, bilateral lower limb joint motion was collected prior to the surgery, at three and six weeks and at three and 6 months after the surgery. Depending upon the patient's preferred walking pace; between 40 and 45 strides were collected during each trial. Kinematic data obtained from force plates embedded in the treadmill were used to identify the heel strike and toe off events for each stride. After time normalizing the each of the joint angles (i.e. hip, knee, ankle) for each stride to 100 data points the data were then amplitude normalized to the initial point of the pre-surgery data. The non-linear tools of angle-angle and phase plane were used to explore relationships that are not readily apparent with linear wave form analyses. Angle-angle diagrams between a variety of joints angles both within a single limb or bilaterally enabled us to explore segmental coordination patterns and how they changed over the six months after surgery. Phase plane analyses included comparing joint motion relative to the velocity of that motion. This technique provided insights into the nature of the control of the joint. The additional information that results from the use of non-linear analyses provides an additional dimension of that can aide the clinician in understanding the recovery curve. This additional insight can be used to guide therapeutic decision making.
A variety of patient reported outcome (PRO) surveys have been established and validated to evaluate the effectiveness of surgical interventions. The Hip Disability and Osteoarthritis Outcome Score (HOOS) has been validated as one method to evaluate the effectiveness of total hip arthroplasty patients. This PRO facilitates the assessment of factors that alter patient outcomes in hip arthroplasty. This retrospective study assesses the effect of psychological post-operative expectations on HOOS in total hip arthroplasty patients. In this pilot study, patient data was collected for 499 patients using the AAOS established Musculoskeletal Outcomes Data Evaluation and Management System (MODEMS) [1] and HOOS surveys. Patient data was matched using similar preoperative HOOS scores to allow for comparable room for improvement in HOOS score postoperatively. These patients were placed into groups of high performers and low performers. HOOS is based on a 0 to 100 scale, 100 as the best. High performers were defined as those with a ratio of change in HOOS score between preoperative and postoperative over the highest difference in score possible (reaching a postoperative HOOS of 100) of 1. Low performers were defined as those with the aforementioned ratio, but under the value of 0.3. Using these defined groups we were able to compare the summation of patient specific MODEMS scores using a univariate regression. The HOOS growth ratio is calculated based on the following. HOOS growth ratio = (HOOS postop – HOOS preop)/(100-HOOS preop) A principal component analysis (PCA) was conducted to identify the significant group of factors that could identify changes in the outcome of 41 patients (20 low performers and 21 high performers).Introduction
Method
Hip Resurfacing has been shown to be a valuable treatment for younger osteoarthritis patients related to functional outcomes. On the other hand, there is a higher risk for potential neck fractures and there is serious concern over metal-ion release and related health risks associated with the current metal-on-metal designs. Neck-preserving, short-stem implants may be a good alternative for younger patients. The current study investigated patient-reported outcomes from resurfacing and total hip arthroplasty (THA) with a neck preserving, short-stem implant (Corin MiniHip®). Hip disability and osteoarthritis outcome scores (HOOS) from a young group of patients (n= 52, age 48.9±6.1 years) who underwent hip resurfacing surgery and a cohort of patients who underwent MiniHip® THA surgery (n=73, age 48.2±6.6) were compared. MANCOVA analysis was conducted including follow-up period as covariate. To compare complexity of the surgical intervention, the average durations for both types of surgery were compared using non-parametric testing (Mann-Whitney's U).Introduction
Methods
The application of digital radiography in orthopaedic settings has facilitated the improvement in the retention and utilization of these images in pre and post-operative assessments [1]. In addition to the cost-effectiveness of such technology the use of digital imaging combined with advanced computer image processing software such as TraumaCadTM software system (TraumaCad, BRAINLAB, Westchester, IL, USA) can provide more accurate details about patients in total hip replacement arthroplasty (THA), a process traditionally called preoperative templating [2] by which intraoperative complications are minimized and overall surgical time is reduced[3]. In a study of 486 patients we demonstrated that patients demographic had significant effect on the outcome of the measurement and utilizing them in a predictive model had helped with improving the results [4]. In this study, we aimed to improve and optimize the proposed algorithm by utilizing more patients’ information and improving the model by using a nonlinear relationship. Our main hypothesis in this study was that the model would significantly predict the actual implant size based on the preoperative assessments. We analyzed the outcome of digital radiographs of 1018 patients who were treated with THA. Digital radiographs were acquired in the anteroposterior view of the pelvis centered over the pubic symphysis. The hip was internally rotated 10° to 15°. We evaluated multiple interactions and nonlinear models and developed the most significant model based on the available clinical data.Introduction
Method
Minimum
Maximum
Mean
Std. Deviation
Templated Acetabulum Size
44.00
64.00
54.12
4.05
Height (m)
147.32
202.20
172.02
10.73
Weight (kg)
39.10
139.10
84.44
19.67
BMI
15.48
43.06
28.33
5.18
Acetabular Size
44.00
64.00
54.25
3.75
11%–19% of patients are unsatisfied with outcomes from Total Knee Arthroplasty (TKA). This may be due to problems of alignment or soft-tissue balancing. In TKA, often a neutral mechanical axis is established followed by soft tissue releases to balance and match the flexion/extension gaps with the distal femoral and proximal tibial resections at right angles to the mechanical axis. Potential issues with establishment of soft tissue balance are due to associated structures such as bone tissue of the knee, the static (or passive) stabilizers of the joint (medial and lateral collateral ligaments, capsule, and anterior and posterior cruciate ligaments), and the dynamic (or active) stabilizers around the knee. An optimized balance among these systems is crucial to the successful outcome of a TKA. Additionally, the importance of correct femoral rotation has been well documented due to its effect on patella alignment and flexion instability, range of motion, and polyethylene wear. There are several methods used in TKA procedures to establish femoral component rotation. The more prominent ones are a conventional method of referencing to the posterior condylar axis with a standard external rotation of 3° (PCR), anterior-posterior line or “Whiteside's line” (AP axis), transepicondylar axis (TEA) (Figure 1), and the gap balancing technique, however, it is not yet clear, which method is superior for femoral rotational component alignment. In the current study, we sought to investigate an alternative method based on soft-tissue, dynamic knee balancing (DKB) while using an alternative analysis approach. DKB dictates femoral component rotation on the basis of ligament balance and force measures. DKB has become more prominent in TKA surgeries. While retaining ligament balance in TKA, it is possible that this technique also leads to higher precision of rotational alignment to the anatomical axis. The primary objective of this study was to compare efficiency of DKB versus other methods for rotational implant alignment based on post-surgery computed tomography (CT). 31 patients underwent computer-navigated total knee arthroplasty for osteoarthritis with femoral rotation established via a flexion gap balance device (Synvasive eLibra). Alternative, hypothetical alignments were assessed based on anatomical landmarks during the surgery. Postoperative computed tomography (CT) scans were analyzed to investigate post-surgery rotational alignment. Repeated measures ANOVA and Cochran's Q test were utilized to test differences between the DKB method and the other techniques.Introduction
Methods
The concept of neck preserving stems, known as short femoral stems or metaphyseal stems has been utilized to improve the outcomes of standard cementless stems. The preservation of the proximal femoral bone stock results in decreasing the potential stress shielding and thigh pain. Additionally, these stems may be used in less invasive procedures and provide the option for easier revision procedures if implant failure occurs. In this study we aim to demonstrate the clinical outcome of direct anterior approach of total hip arthroplasty (THA) with short stem prosthesis. In this study, 390 total cases of THA in 345 patients who underwent an anterior approach of THA by using a new type of short-stem prosthesis (Minihip, Corin) between 2009 and 2013 were reviewed. There were 282 male and 62 female patients and Table 1 summarizes the demographics. In 48 cases avascular necrosis (AVN) was the diagnosis and 339 cases were reported to be due to osteoarthritis. Twenty eight patients were assessed to have American Society of Anesthesiologist (ASA) physical functional score of class I, 258 patients had class II, 103 had class III, and 1 had class IV. Table 2 shows the Charnley classification of the patients. In the current study we evaluated the outcomes of the surgery by utilizing Hip Disability and Osteoarthritis Outcome Score (HOOS) subscales (Pain, Symptoms, Function in daily living (ADL), Function in sport and recreation (Sport) and hip related Quality of life (QOL)).Introduction
Methods
Hip arthroplasty is an ultimate treatment for individuals with severe hip osteoarthritis. There are several available approaches when performing this type of surgery, however there is a growing interest in using the least invasive procedures. These less invasive procedures aid in healthy bone preservation which may be particularly important for younger populations undergoing hip arthoplasy (Rajakulendran & Field, 2012). Accurate and reliable measurement techniques are needed to better study and monitor the outcome of different implantation techniques during the postop recovery. To develop a better understanding of spatiotemporal aspects of gait pre- and post- hip arthroplasty through the anterior approach.BACKGROUND
OBJECTIVES
Cementless stems have been used in treatment of patients with osteoarthritis however, the new design concept of neck preserving stems also known as short femoral stems have been utilized to decrease the potentially adverse symptoms of the standard stems such as stress shielding and thigh pain. In this ongoing study we aim to demonstrate the clinical and radiographic outcome of direct anterior approach of total hip arthroplasty (THA) by using short stem prosthesis. In this study, 390 total cases of THA in 345 patients who underwent an anterior approach of THA by using a short-stem prosthesis (Minihip, Corin) between 2009 and 2013 were reviewed. This group included 282 male and 62 female patients. Table 1 summarizes the demographic information of the patients. In 48 cases avascular necrosis (AVN) was the diagnosis and 339 cases was reported to be due to osteoarthritis. Twenty eight patients were assessed to have American Society of Anesthesiologist (ASA) physical functional score of class I, 258 patients had class II, 103 had class III, and 1 had class IV. In the current study we evaluated the outcomes of the surgery by utilizing Hip Disability and Osteoarthritis Outcome Score (HOOS) subscales (Pain, Symptoms, Function in daily living (ADL), Function in sport and recreation (Sport/Rec) and Quality of life (QOL)).Introduction
Methods
The application of digital radiography in clinical settings has provided the opportunity to obtain high quality images while reducing the overall cost of imaging, thus this technology is gaining more popularity in clinical settings specifically in orthopaedic clinics 1. In addition, advanced computer software helps with quick and easy approach to perform preoperative measurements with high accuracy 2. Preoperative templating has become one of the standard of care procedures that prepares the surgical team to lower surgical time and more efficiently face intraoperative complications 3. Commonly, the acetabular cup size and femoral stem size are templated and used for estimation process 4. However, the goal of this study was to investigate whether patients' demographics would play a role in increasing the accuracy of templating. We hypothesized that preoperative implant templating (acetabular and femoral components), gender, weight, height, and body mass index (BMI) would contribute to higher accuracy of templating in total hip arthroplasty (THA). Digital radiographs of 468 patients treated with THA from August 2012 to December 2013 at a single institution were reviewed. They aged 59.96 ±12.50 years and 436 of them were diagnosed with osteoarthritis, 53 with avascular necrosis, 13 with failed THA, 2 with infection, 4 post trauma, and 13 with failed hemi arthroplasty. THA templating was conducted by assessing the anteroposterior view of the pelvis that was centered over the pubic symphysis, with the hips in 10° to 15° of internal rotation and we utilized a lateral frog-leg view of the affected hip. A backward stepwise multiple regression model was used to exclude the parameters that had no significant contribution to the accuracy of the measurement.Introduction
Method
Unicompartmental knee replacement (UKR) facilitates the use of smaller sized implants that require less bone resection and allows preservation of the anterior and posterior cruciate ligaments (ACL and PCL)[1]. Therefore, UKR preserves the intact kinematics and may improve the clinical outcomes especially compared to the outcomes of total knee replacement (TKA). Despite the known benefits of UKR in arthritis limited to one compartment, in multicompartment disease TKA remains the gold standard. Current TKA designs require the sacrifice of the ACL in all cases, whereas the surgeon can decide to use a cruciate sparing or substituting design altering normal knee kinematics. Performing bi-UKR or tri-UKR with traditional instruments is very challenging and rarely done due to the difficulty in establishing the correct spatial relationship of the separate components. Recent advances in robotic surgery have provided the opportunity to utilize partial knee replacements. The MAKO Rio platform is a surgeon-interactive robotic arm with haptic guidance that allows computer assisted planning and intraoperative accurate placement of multiple unicompartmental components including the bi-UKR. Currently there is a lack of understanding about the short-term and long-term clinical outcomes of the bi-UKR compared to the traditional TKA. The objective of the current study was to investigate the differences in the clinical outcomes of bi-UKR and TKA.INTRODUCTION:
OBJECTIVES:
Discrepancies in patient outcomes after total knee arthroplasty have encouraged the development of different treatment options including early preventive interventions. In addition, improvements in surgical techniques and instrumentation have increased the accuracy of the surgeries. In this case study, we review the first robotic-arm assisted modular tricompartmental knee arthroplasty in which bone and soft tissues are conserved by employing a precise planning and execution technique. A 63 year old Caucasian female with a Body Mass Index (BMI) of 27 presented to the surgeon (SK) with knee pain and a varus mechanical alignment. The patient received modular tri-unicompartmental arthroplasty performed with robotic-arm assistance; (see figure 1 for post-op radiograph). Range of Motion (ROM), Knee Society Score (KSS) and Knee Injury and Osteoarthritis Outcomes Score (KOOS) were measured pre-operatively and post-operatively at 6, 16, and 23 months. At 6 months post-op an in-depth in vivo kinematic analysis was conducted by using a validated fluoroscopic assessment technique [1]. The patient simulated stair climbing, kneeling activity, and deep lunge while under single plane fluoroscopy. Three dimensional models were created from CT scans and were matched to 2D fluoroscopic images for kinematic assessment.Background
Materials and Methods
The popularity of the direct anterior approach (DAA) for total hip arthroplasty (THA) is increasing as this approach causes less soft tissue damage and no muscular detachments and significantly shorter postoperative recovery time. Despite the promising early results the complication rate in the DAA cases has been concerning such as 9% rate in 247 DAA cases reported by Woolen et. al [1]. As DAA has not conventionally being used by surgeons these complications are expected to be reduced when the surgeons are more experienced. Therefore to better understand the issues that cause the postop complications in DAA we have conducted the present study. The objective of the current study is to investigate the postop complications in individuals with arthritic hips treated by DAA THA over a period of 3.5 years by a one surgeon.INTRODUCTION:
OBJECTIVES:
The current study was conducted to report the short-term clinical outcome of the THA by using Minihip neck preserving stem.INTRODUCTION:
OBJECTIVES: