Proper component orientation and soft tissue balancing are essential for longevity of total knee arthroplasty (TKA), especially in young and active patients. The aim of this study was to evaluate long-term results and quality of TKA in young and active patients with extension first gap balancing technique, in 2 Posterior-Stabilized (PS) total knee designs with identical femoral component. 43 consecutive Rotating-Platform (RP-PS, 33 patients) and 38 Fixed-Bearing (FB-PS, 29 patients) with University of California Los Angeles (UCLA) activity score of 5 or above and mean age was 53 ± 1.5 years were followed prospectively for a minimum of 10 years. 18 random TKAs were analyzed for component rotation using MRI.Introduction:
Material and Methods:
Total hip arthroplasty (THR) is one of the most successful procedures performed today. Uncemented acetabular components have by and large replaced cemented cups. As such, optimal fixation, bony ingrowth with longevity, and safety is highly demanded. In this study, we look at the safety and efficacy of the Stryker® Trident PSL™ acetabular component based on radiographic and clinical analysis. We looked at 860 consecutive patients between 2003 and 2007. Of these, 231 consecutive patients had a minimum 5 year follow up. All cases were for degenerative joint disease (DJD), except 2 for dysplasia, 1 for avascular necrosis (AVN), 1 femoral neck nonunion. Average Hospital for Special Surgery (HSS) hip scores at final follow up were recorded. Radiographic analysis included classification based on Delee and Charnley's zones 1–3. Osseointegration was assessed based on presence of Introduction
Materials and Methods
Jumbo cups (58 mm or larger diameter in females and 62 mm or larger diameter in males), theoretically have lowered the percentage of bleeding bone that is required for osseointegration in severe acetabular defects. The purpose of this study was to analyze the safety and efficacy of Tritanium jumbo cups in patients with major acetabular defects (Paprosky type IIIa and IIIb) and assess the extent of osseointegration. From February 2007 and August 2010, 28 consecutive hips (26 patients, mean age of 69 years) underwent acetabular revision arthroplasty for treatment of Paprosky type IIIa and IIIb defects using Tritanium jumbo cups (Stryker, Mahwah, New Jersey).Introduction:
Material and Methods:
Numerous studies have reported the importance of acetabular component positioning in decreasing dislocation rates, the risk of liner fractures, and bearing surface wear in total hip arthroplasty (THA). The goal of improving acetabular component positioning has led to the development of computer-assisted surgical (CAS) techniques, and several studies have demonstrated improved results when compared to conventional, freehand methods. Recently, a computed tomography (CT)-based robotic surgery system has been developed (MAKO™ Robotic Arm Interactive Orthopaedic System, MAKO Surgical Corp., Fort Lauderdale, FLA, USA), with promising improvements in component alignment and surgical precision. The purpose of this study was to compare the accuracy in predicting the postoperative acetabular component position between the MAKO™ robotic navigation system and an imageless, CAS system (AchieveCAS, Smith and Nephew Inc., Memphis, TN, USA). 30 THAs performed using the robotic navigation system (robotic cohort) were available for review, and compared to the most recent 30 THAs performed using the imageless, CAS system (CAS cohort). The final, intraoperative reading for acetabular abduction and anteversion provided by each navigation system was recorded following each THA. Einsel-Bild-Roentgen analysis was used to measure the acetabular component abduction and anteversion based on anteroposterior pelvis radiographs obtained at each patient's first, postoperative visit (Figure 1). Two observers, blinded to the treatment arms, independently measured all the acetabular components, and the results were assessed for inter-observer reliability. Comparing the difference between the final, intraoperative reading for both acetabular abduction and anteversion, and the radiographic alignment calculated using EBRA analysis, allowed assessment of the intraoperative predictive capability of each system, and accuracy in determining the postoperative acetabular component position. In addition, the number of acetabular components outside of the “safe zone” (40° + 10° of abduction, 15° + 10° of anteversion), as described by Lewinnek et al., was assessed. Lastly, the operative time for each surgery was recorded.Background:
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Patellar mobilisation methods used during total knee arthroplasty (TKA) have been debated in the literature, with some proponents of minimally invasive TKA suggesting that laterally retracting, rather than everting the patella may be beneficial. It was our hypothesis that by using randomised, prospective, blinded study methods, there would be no significant difference in clinical outcome measures based solely on eversion of the patella during total knee arthroplasty. After an Introduction
Methods
The goal of revision total hip arthroplasty (THA) for acetabular defects is to achieve the best stability and fixation with available host bone. Tritanium is a highly porous metal construct with a titanium matrix coating. We are reporting our experience of utilizing this material in patients with major acetabular defects. Between February 2007 and August 2010, 24 consecutive hips (23 patients) underwent acetabular reconstruction using the Tritanium cups. The acetabular defects were assessed using the Paprosky classification. Anteroposterior and lateral radiographs were analyzed at follow-up based for the presence of radiolucent lines more than 2 mm in any of the 3 zones.Introduction
Methods
Ceramic femoral heads have superior scratch resistant with better wettability and improved wear characteristics compared to metal heads in the laboratory setting. The objective of this study was to compare long-term in vivo wear rates of ceramic and metal femoral heads against conventional polyethylene articulation with cementless stems in young, active patients. Thirty-one matched pair of alumina and metal (Cr-Co) femoral heads against conventional polyethylene in young patients (between 45 and 65 years old) were analyzed for wear and failures for mechanical reasons. The match was based on gender and age at the time of surgery. All procedures were performed between June 1989 and May 1992 by a single surgeon via posterolateral approach, using cementless RB (Ranawat-Bernstein) stems, HG II (Harris-Galante) cups, 4150 conventional polyethylene and 28 mm femoral heads. Hospital for Special Surgery (HSS) hip score was used for clinical analysis. Wear measurements were performed between the initial anteroposterior standing pelvis radiographs, at a minimum of one year after the index procedure to eliminate the effect of bedding-in period, and the latest follow-up. Two independent observers analyzed polyethylene wear rates using the computer-assisted Roman 1.70 software. In revision cases, the wear rates were calculated from radiographs prior to revision surgery. A pair student t test was performed to analyze the statistical difference. Two-tailed ρ values less than 0.05 were considered statistically significant.Introduction
Materials and Methods
Osteoarthritis (OA) of the hip and the knee has been found to affect sexual activity. Few retrospective studies have investigated the role of total hip replacement on sexual function. We designed a prospective study to evaluate the influence of total hip arthroplasty (THA) and total knee arthroplasty (TKA) on the physical and psychological aspects of sexuality of patients. Between April 2009 and April 2011, patients under 70 years of age scheduled for primary THA or TKA for OA were invited to anonymously participate in this study. All patients were recruited from the practices of 2 arthroplasty surgeons (at the same institution) by mailing the 2 questionnaires, 2 pre-paid self-addressed envelopes and a cover letter. Patients were instructed to mail back the pre-operative questionnaire prior to surgery and the post- operative questionnaire 6 months after surgery. Enrolled patients were also contacted after 1 year of surgery to fill a similar questionnaire. Responses were identified only by a unique code number on the questionnaire.INTRODUCTION
METHODS
Cadaveric studies have reported damage to the direct head of rectus femoris and tensor fascia lata muscles with direct anterior approach(DAA) and to the abductors, external rotators with posterior approach(PA). The aim of this prospective study was to evaluate differences in hip muscle strength recovery between DAA and posterior approach (PA) THA. Patients with unilateral hip osteoarthritis undergoing THA at a single institution from January 2011 to October 2011 were enrolled. All DAA THA's were performed by one surgeon, and all PA THA's were performed by another surgeon with similar design of components, pain management and rehabilitation protocols. Hip muscle strength was measured with a handheld dynamometer in all planes by a single observer preoperatively, at 6 weeks, 3 months and 6 months. Functional recovery was assessed with the motor component of Functional Independence Measure, UCLA activity score, Harris hip score, SF-12 score.INTRODUCTION
METHODS
Unicompartmental knee replacement (UKR) has good outcomes for the treatment of compartmental osteoarthritis of the knee. Mechanical alignment overcorrection is associated with early failure of the femoral and tibial components. Preoperative mechanical alignment is the most important predictor of postoperative alignment. However, most studies do not take into consideration the magnitude of preoperative deformity when reporting on mechanical alignment outcomes after UKR. We aimed to determine the magnitude of postoperative mechanical alignment achieved based on the magnitude of preoperative alignment; and to compare the number of cases of overcorrection into valgus to historical data. This was a radiographic review of patients who underwent robotic medial UKR by a single surgeon between 2007 and 2011. Two examiners measured pre- and postoperative mechanical alignment for all patients on long-leg radiographs. Patients were classified into three groups of preoperative mechanical alignment: mild varus (0–5®); moderate varus (5–10®); and severe varus (>10®). Patients with valgus alignment (<0®) were excluded. Linear regression was used to estimate the magnitude of postoperative alignment for each group, adjusting for age, BMI, gender, side, implant type, and polyethylene thickness. 89 patients were included. Mean preoperative alignment was 7.3® varus (95% CI = 6.6®–8®; range, 0.1–15® varus). Mean postoperative alignment was 2.8® varus (95% CI = 1.9®–3.8®; range, 1.4® valgus–9.7® varus). There was a significant difference in postoperative mechanical alignment between the three groups (Table 1) (P<0.05). Four overcorrections (4.5%) were detected, all under 1.5® valgus. This percentage of overcorrection was significantly better than previous conventional UKR reports (mean = 12.6%; P = 0.04). The magnitude of postoperative alignment in medial UKR depends on the severity of the preoperative deformity. Reports on radiographic outcomes of UKR should be stratified by the magnitude of preoperative alignment. The risk of overcorrection is reduced when using robotic assistance compared to using the conventional manual technique.
Ceramic femoral heads have proven to be more scratch resistant with better wettability and improved wear characteristics compared to metal heads in the laboratory setting. The objective of this study was to compare long-term survivorship and in vivo wear rates of ceramic and metal femoral heads against conventional polyethylene articulation in young patients. Thirty-one matched pair of alumina and metal femoral heads against conventional polyethylene in young patients (≤ 65 years) were analyzed for wear and failures for mechanical reasons. The match was based on gender and age at the time of surgery. All procedures were performed between June 1989 and May 1992 by a single surgeon via posterolateral approach, using non-cemented RB (Ranawat-Bernstein) stems, HG II (Harris-Galante) cups, 4150 conventional polyethylene and 28mm femoral heads. Hospital for Special Surgery (HSS) hip score was used for clinical analysis. Wear measurements were performed between the initial anteroposterior standing pelvis radiographs, at a minimum of one year after the index procedure to eliminate the effect of bedding-in period, and the latest follow-up. Two independent observers analyzed polyethylene wear rates using the computer-assisted Roman 1.70 software. In revision cases, the wear rates were calculated from radiographs prior to revision surgery. A pair student t test was performed to analyze the statistical difference. Two-tailed ρ values less than 0.05 were considered statistically significant.Introduction
Materials and Methods
Symptomatic hip disorders associated with cam deformities are routinely treated with surgery, during which the deformity is resected in an effort to restore joint range of motion, reduce pain, and protect the joint from further degeneration. This is a technically demanding procedure and the amount of correction is potentially critical to the success of the procedure: under-resection could lead to continued progression of the OA disease process in the joint, while over-resection puts the joint at risk for fracture. This study compares the accuracy of a new robotically assisted technique to a standard open technique. Sixteen identical Sawbones models with a cam type impingement deformity were resected by a single surgeon simulating an open procedure. An ideal final resected shape was the surgical goal in all cases. 8 procedures were performed manually using a free-hand technique and 8 were performed using robotic assistance that created a 3-dimensional haptic volume defined by the desired post-operative morphology. All of 16 sawbones, including uncut one as well, were scanned by Roland LPX-600 Laser scanner with 1mm plane scanning pitch and 0.9 degree of rotary scanning. Post-resection measurements included arc of resection, volume of bone removed and resection depth and were compared to the pre-operative plan.INTRODUCTION
METHODS
Fixation remains a challenge in Revision TKR. Irregular and cavitary bone loss may precludeproper metaphyseal cementation and pressurization. Metaphyseal sleeves have been proposed to improve theinherent rotational stability of the implant bone interface. The goal of this study was to assess the effect of the use of metaphyseal sleeves on the quality of the cement fixation achieved. Fifty consecutive revision TKRs for AORI type 2 and 3 bone loss between January 2005 through January 2008 with average 2 years follow up were assessed retrospectively. Twelve patients were excluded for inadequate follow up. Nineteen patients with 26 cemented metaphyseal sleeves (15 tibiae and 11 femora) formed group 1 and 19 patients with 36 revision components (without metaphyseal sleeves) served as control (group 2). Patients were assessed clinically with knee society scores (KSS) and radiographically by quality of metaphyseal cement mantle and radiolucent lines(RLL). Groups were matched for pre-op bone loss and length of follow-up.Introduction
Methods
Mechanical integrity of patella can be weakened by the technique of removing the articulating surface. The senior author developed the technique of maintaining subchondral bone of the lateral patellar facet in early 1980s. Though laboratory studies have demonstrated deleterious effect of excessive resection of patella on the strains in the remaining bone under load; clinical studies have not shown the importance of strong subchondral bone of lateral facet to have an effect on patellar fracture prevalence. We present the results of our patellar resection technique preserving the subchondral bone of lateral facet. 393 TKRs were performed between 1989 and 1996 using cruciate substituting modular knee with recessed femoral trochlear groove and congruent patello-femoral articulation. 45 patients with 48 knees died and 37 patients with 41 knees were lost to follow-up. Three hundred and four knees were followed for an average 10 years (range 5 -16 years). Patellar surface was resected with an oscillating saw without the use of cutting guide. The medial facet and most of the articular cartilage of the lateral facet was resected, while preserving the subchondral bone of lateral facet. An all-polyethylene implant with single peg was used in most cases.Introduction
Methods
It is not uncommon to encounter patients with atypical hip or lower extremity pain, ill-defined clinico-radiological features and concomitant hip and lumbar spine arthritis. It has been hypothesized that an anaesthetic hip arthrogram can help identify the source of pain in these cases. The purpose of this study is to analyze our experience with this technique in order to verify its accuracy. We undertook a retrospective analysis of 204 patients who underwent a hip anesthetic-steroid arthrogram for diagnostic purposes matching our inclusion criteria. Patient charts were scrutinized carefully for outcomes of arthrogram and treatment. Harris Hip Score was used to quantify outcome.Introduction
Methods
The current fellowship hiring process is decentralized, poorly functioning, unraveled and generally unfair. It creates anxiety for residents, residency directors, and fellowship directors alike. Residents are facing exploding offers, limited exposure to fellowship programs and, ultimately, an unraveling hiring market. Residents are in favor of changing the current decentralized process into either a more centralized clearing-house system or subspecialty-based match approach. In either system, accountability for both residents and fellowship directors is critical. Both the AOA and AAOS should devote resources to improve the fellowship hiring process.
The ability of optimised MRI to detect periarticular bony and soft tissue pathology in the post-arthroplasty hip is well documented; specifically it is able to detect early stages of particle disease well before osteolysis is apparent on radiographs. This is a prospective study designed to utilise MRI for the detection of early particle disease in asymptomatic patients after total hip arthroplasty. Patients who underwent routine non-cemented THA were recruited from three different groups: metal-on-polyethylene, ceramic-on-ceramic, and ceramic-on-polyethylene bearing surfaces. All patients enrolled underwent optimised MRI one to three years (mean 1.7) after the index procedure. Images were analyzed for the presence of synovial proliferation, fibrous membrane formation or osteolysis. Particle disease was correlated with type of bearing surface, pain, activity level, patient satisfaction, and clinical outcome scales. Thirty-two hips have been enrolled in the study to date. Early particle disease was seen in two of seven metal-on-polyethylene hips (29%), four of twelve ceramic-on-ceramic hips (33%), and six of thirteen ceramic-on-polyethylene hips (46%). Focal osteolysis was seen in one patient with a ceramic-on-polyethylene hip. These values were not statistically significant among the groups. The presence of early particle disease did not correlate with pain, activity level, patient satisfaction, or other clinical outcome scales. This study allows patients with a well functioning total hip arthroplasty to be prospectively followed with MRI. It is the first to document the natural history of particle disease in vivo and considerably enhances our knowledge of periarticular pathology in the post-operative hip. These results demonstrate early particle disease is relatively common yet asymptomatic; they do not demonstrate advantages of any bearing couple over another for protection against particle disease at short-term follow-up.
