Short Term Outcomes (Average Follow-Up of 2.4 Years) of a Constrained Acetabular Liner in Primary and Revision Total Hip Arthroplasty.

BACKGROUND: As instability continues to be a burden post-total hip arthroplasty (THA), there has been a controversial discussion on the ideal implant choice. We report the outcomes of a modern constrained acetabular liner (CAL) system in primary and revision THA at an average follow-up of 2.4 years. METHODS: We performed a retrospective study of all patients undergoing primary and revision hip arthroplasty and being implanted with the modern CAL system from 2013 to 2021. We identified 31 hips, of which 13 underwent primary THA and the remaining 18 underwent revision THA for instability. RESULTS: Of those implanted with CAL primarily, 3 had concomitant abductor tear repair and gluteus maximus transfer, 5 had Parkinson's disease, 2 had inclusion body myositis, 1 had amyotrophic lateral sclerosis, and the remaining two were over 94 years of age. All patients implanted with the CAL had active instability post-primary THA and underwent only liner and head exchange without revision of the acetabular or femoral components. At an average follow-up of 2.4 years (ranging from 9 months to 5 years and 4 months), we had 1 case (3.2%) of dislocation post-CAL implantation. None of the patients undergoing surgery with CAL for active instability had a redislocation. CONCLUSION: In conclusion, a CAL provides excellent stability in both primary THA in high-risk individuals and revision THA in cases of active instability. There were no dislocations when using a CAL to treat active instability post-THA.

Clinical Outcomes of a Modern Total Knee Arthroplasty Prosthesis Compared to Its Predecessor at 5-Year Follow-Up: Matched Pair Analysis.

BACKGROUND: Residual pain is an important cause of patient dissatisfaction after total knee arthroplasty (TKA). A recent study at our institution found that a modern prosthesis was associated with less residual and anterior knee pain at 2-year follow-up when compared to its predecessor. The aim of this study is to evaluate these implants at 5-year follow-up. METHODS: From July 2012 to December 2013, 100 consecutive modern TKAs were identified from our prospective Institutional Review Board approved database. All patients with 5-year clinical follow-up (n = 77) were matched in a one-to-one fashion based on age, gender, body mass index, and follow-up with a predecessor TKA. Clinical outcomes were assessed with a patient-administered questionnaire for specifically anterior knee pain, painless noise, painful crepitation, and satisfaction. Overall function was assessed using Knee Society Scores and Western Ontario and McMaster University Osteoarthritis Index. RESULTS: At 5-year follow-up, there were no significant differences between the modern TKA and a predecessor TKA in the Knee Society pain or function scores (P = .24 and P = .54, respectively). The overall prevalence of residual pain was less with the modern TKA compared to its predecessor (19.5% vs 36.3%; P = .02), but the prevalence of isolated anterior knee pain was similar in both cohorts (11.7% vs 22.1%; P = .09). There was no difference in painless noise (19.5% vs 13.3%; P = .28) or satisfaction scores (7.9 ± 2.4 vs 7.6 ± 2.6; P = .25) between the modern and predecessor cohorts. CONCLUSION: At 5-year follow-up, we found that both the modern and predecessor prostheses provided excellent clinical outcomes. The modern TKA was associated with less residual pain compared to its predecessor, but we were unable to detect differences in the prevalence of isolated anterior knee pain, painless noise, Knee Society Scores, or radiographic evaluation.

Biomechanical Assessment of a Novel Posterior Soft Tissue Repair Technique in Primary Total Hip Arthroplasty.

INTRODUCTION: Instability is one of the most common complications after total hip arthroplasty (THA), particularly when using the posterior approach. Repair of the posterior capsule has proven to significantly decrease the incidence of posterior hip dislocation. The purpose of the present study is to evaluate if a racking hitch knot utilizing a 2mm braided polyblend suture provides a stronger repair of the posterior soft tissues when compared to a traditional repair utilizing a non-absorbable suture after a posterior approach to the hip. MATERIALS AND METHODS: Ten cadaveric hips from donors, who were at a mean age of 80 ± 9 years old at the time of death, were evaluated after posterior soft tissue repair utilizing two different techniques. Five specimens were repaired utilizing a racking hitch knot with a 2mm braided polyblend suture (FiberTape®, Arthrex GmbH, Naples, Florida) and five other specimens were repaired with a traditional repair using a no. 2 non-absorable suture (FiberWire®, Arthrex GmbH, Naples, Florida). Cadaveric specimens were matched based upon age, sex, and laterality. Biomechanical tensile testing using the Instron E10000 Mechanical Testing System and the mechanisms of failure (MOF) were assessed. RESULTS: The ultimate load to failure was three times higher using braided polyblend sutures (390.00 ± 129.08 N) compared to non-absorbable sutures (122.81 ± 82.41 N) after posterior soft tissue repair (p<0.01). In the braided polyblend suture cohort, the mechanism of failure most commonly occurred as the braided suture pulled through the posterior soft tissues. However, in the non-absorbable suture repair, failure took place at the suture knot. CONCLUSION: The use of our posterior capsular repair utilizing a braided polyblend suture and racking hitch knot provides for a stronger repair of the posterior soft tissues when compared to non-absorbable suture repair following a posterior approach to the hip joint.

Addition of Infiltration Between the Popliteal Artery and the Capsule of the Posterior Knee and Adductor Canal Block to Periarticular Injection Enhances Postoperative Pain Control in Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Periarticular injections (PAIs) are becoming a staple component of multimodal joint pathways. Motor-sparing peripheral nerve blocks, such as the infiltration between the popliteal artery and capsule of the posterior knee (IPACK) and the adductor canal block (ACB), may augment PAI in multimodal analgesic pathways for knee arthroplasty, but supporting literature remains rare. We hypothesized that the addition of ACB and IPACK to PAI would lower pain on ambulation on postoperative day (POD) 1 compared to PAI alone. METHODS: This triple-blinded randomized controlled trial included 86 patients undergoing unilateral total knee arthroplasty. Patients either received (1) a PAI (control group, n = 43) or (2) an IPACK with an ACB and modified PAI (intervention group, n = 43). The primary outcome was pain on ambulation on POD 1. Secondary outcomes included numeric rating scale (NRS) pain scores, patient satisfaction, and opioid consumption. RESULTS: The intervention group reported significantly lower NRS pain scores on ambulation than the control group on POD 1 (difference in means [95% confidence interval], -3.3 [-4.0 to -2.7]; P < .001). In addition, NRS pain scores on ambulation on POD 0 (-3.5 [-4.3 to -2.7]; P < .001) and POD 2 (-1.0 [-1.9 to -0.1]; P = .033) were significantly lower. Patients in the intervention group were more satisfied, had less opioid consumption (P = .005, postanesthesia care unit, P = .028, POD 0), less intravenous opioids (P < .001), and reduced need for intravenous patient-controlled analgesia (P = .037). CONCLUSIONS: The addition of IPACK and ACB to PAI significantly improves analgesia and reduces opioid consumption after total knee arthroplasty compared to PAI alone. This study strongly supports IPACK and ACB use within a multimodal analgesic pathway.

Single- Versus Double-Row Repair of Hip Abductor Tears: A Biomechanical Matched Cadaver Study.

PURPOSE: The purposes of this study were (1) to evaluate the percentage of gluteus medius and minimus tendon footprint restoration that can be achieved with fixation using single-row repair versus double-row repair and (2) to evaluate the yield load of a repair of the gluteus medius and minimus tendon using single-row versus double-row repair techniques. METHODS: Twelve human fresh-frozen cadaveric hip specimens (6 matched pairs, 4 female, mean age 47.5 ± 14.5 years) were tested. Specimens were excluded if they had any prior hip surgery or injury, if any abnormality of the tendon was noted on dissection, or if they had a body mass index <20 or >35 or a T-score <2.0 on dual-energy x-ray absorptiometry scanning. Matched pairs were randomized to receive either double-row repair with 2 standard suture anchors and 2 knotless anchor devices or a single-row repair with suture anchors only. The percentage of the footprint area covered after repair was determined using a computer-assisted digitization algorithm. With a mechanical testing system, each repaired specimen was tested for mechanical strength first with cyclic loading and then load to failure testing. RESULTS: Footprint coverage of the lateral facet was significantly greater for double-row repair (mean 76.6%) compared with single-row repair (mean 50.3%) (P = .03). There was no significant difference between single- and double-row repair for posterior-superior or anterior facet coverage. Mechanical testing showed a higher mean yield load for double-row anchor repair (197.6 ± 61.7 N vs 163.5 ± 35.4 N for single-row repair), but this did not reach statistical significance (P = .15). The predominant mode of failure was suture pullout through the musculotendinous unit (9/12 specimens: 5 double-row and 4 single-row). CONCLUSIONS: For hip abductor tears, double-row suture repair yields improved footprint coverage compared with single-row repair. Although it did not reach statistical significance, there was a higher mean yield load in the double-row group. CLINICAL RELEVANCE: Double-row suture fixation technique for hip abductor tears maximizes strength and footprint coverage of the repair.

Role of Anatomical Patella Replacement on Anterior Knee Pain.

BACKGROUND: Anterior knee pain (AKP) remains a complex issue affecting patient satisfaction after total knee arthroplasty. Several radiographic parameters have been shown to be causative factors with various designs. The aim of this study is to evaluate the known radiographic parameters of AKP and clinical outcomes (ie, AKP) in the setting of a modern prosthesis with an anatomic patella button. METHODS: Between July 2012 and December 2013, 90 total knee arthroplasties received 3 skyline views taken at 30°, 45°, and 60°. A patient-administered questionnaire was administered at 2-year follow-up to assess the incidence of AKP, painless noise, and satisfaction. Radiographs were analyzed for patellofemoral overstuffing, patellar tilt, and patellar displacement, and evaluated the patella resection angle. RESULTS: On the patient-administered questionnaire, 10 (11.1%) patients reported AKP of a mild-to-moderate nature. Thirty-one had the best view at 30 Merchant views, 24 had best views at 45, and 35 had best views at 60. We found that patellar resection angle correlated with AKP (odds ratio 1.21, P = .044) and painless noise (odds ratio 1.22, P = .034). Patellar displacement and patellofemoral stuffing did not correlate with AKP or painless noise. No radiographic measurements correlated with changes in Knee Society Score pain or function scores or range of motion. CONCLUSION: We found that a patellar resection angle correlated with the incidence of AKP and painless noise at 2-year follow-up. We failed to find any correlation with patellofemoral overstuffing, patellar displacement, or patellar tilt with clinical outcomes. We recommend the use of 3 Merchant views to fully evaluate the patellofemoral joint.

Preoperative Physical Therapy Education Reduces Time to Meet Functional Milestones After Total Joint Arthroplasty.

BACKGROUND: As length of stay decreases for total joint arthroplasty, much of the patient preparation and teaching previously done in the hospital must be performed before surgery. However, the most effective form of preparation is unknown. This randomized trial evaluated the effect of a one-time, one-on-one preoperative physical therapy education session coupled with a web-based microsite (preopPTEd) on patients' readiness to discharge from physical therapy (PT), length of hospital stay, and patient-reported functional outcomes after total joint arthroplasty. QUESTIONS/PURPOSES: Was this one-on-one preoperative PT education session coupled with a web- based microsite associated with (1) earlier achievement of readiness to discharge from PT; (2) a reduced hospital length of stay; and (3) improved WOMAC scores 4 to 6 weeks after surgery? METHODS: Between February and June 2015, 126 typical arthroplasty patients underwent unilateral TKA or THA. As per our institution's current guidelines, all patients attended a preoperative group education class taught by a multidisciplinary team comprising a nurse educator, social worker, and physical therapist. Patients were then randomized into two groups. One group (control; n = 63) received no further education after the group education class, whereas the intervention group (experimental; n = 63) received preopPTEd. The preopPTEd consisted of a one-time, one-on-one session with a physical therapist to learn and practice postoperative precautions, exercises, bed mobility, and ambulation with and negotiation of stairs. After this session, all patients in the preopPTEd group were given access to a lateralized, joint-specific microsite that provided detailed information regarding exercises, transfers, ambulation, and activities of daily living through videos, pictures, and text. Outcome measures assessed included readiness to discharge from PT, which was calculated by adding the number of postoperative inpatient PT visits patients had to meet PT milestones. Hospital length of stay (LOS) was assessed for hospital discharge criteria and 6-week WOMAC scores were gathered by study personnel. At our institution, to meet PT milestones for hospital discharge criteria, patients have to be able to (1) independently transfer in and out of bed, a chair, and a toilet seat; (2) independently ambulate approximately 150 feet; (3) independently negotiate stairs; and (4) be independent with a home exercise program and activities of daily living. Complete followup was available on 100% of control group patients and 100% patients in the intervention group for all three outcome measures (control and intervention of 63, respectively). RESULTS: The preopPTEd group had fewer postoperative inpatient PT visits (mean, 3.3; 95% confidence interval [CI], 3.0-3.6 versus 4.4; 95% CI, 4.1-4.7; p < 0.001) and achieved readiness to discharge from PT faster (mean, 1.6 days; 95% CI, 1.2-1.9 days versus 2.7 days; 95% CI, 2.4-3.0; p < 0.001) than the control group. There was no difference in hospital LOS between the preopPTEd group and the control group (2.4 days; 95% CI, 2.1-2.6; p = 0.082 versus 2.6 days; 95% CI, 2.4-2.8; p = 0.082). There were no clinically relevant differences in 6-week WOMAC scores between the two groups. CONCLUSIONS: Although this protocol resulted in improved readiness to discharge from PT, there was no effect on LOS or WOMAC scores at 6 weeks. Preoperative PT was successful in improving one of the contributors to LOS and by itself is insufficient to make a difference in LOS. This study highlights the need for improvement in other aspects of care to improve LOS. LEVEL OF EVIDENCE: Level II, therapeutic study.

Wear Analysis of Highly Cross-Linked Polyethylene in Young and Active Patients at Average Fourteen Years: A Concise Follow-Up of a Previous Report.

BACKGROUND: Concerns persist regarding the oxidative stability of annealed highly cross-linked polyethylene (HXLPE) and hence its wear performance especially long term in young and active patients. The purpose of this study is to assess the wear rates and clinical outcomes of a first-generation annealed HXLPE. METHODS: Forty-six patients (57 hips) with noncemented fixation, a mean age of 53 years, and a mean University of California Los Angeles activity score of 8 underwent primary total hip arthroplasty. A 28-mm femoral head against HXLPE liner was used in all cases. Linear wear rates were measured by 2 independent observers. Radiological and clinical assessments were recorded. RESULTS: At a mean of 14 years (range 10-17), the wear rate was 0.03 mm/y (SD ±0.02). There were no revisions for wear-related complications. Using revision for wear-related complications as an endpoint, the survivorship was 100% and we observed no osteolysis. Western Ontario and McMaster Universities Osteoarthritis Index, patient administered questionnaire, and Hospital for Special Surgery hip scores were 91/100, 5/100, and 37/40 respectively. CONCLUSION: This study confirms that a first-generation annealed HXLPE shows excellent wear and clinical results at 10-17 years in young and active patients. Oxidative degradation of an annealed HXLPE does not adversely affect wear and shows no other wear-related complications.

Wear Rates With Large Metal and Ceramic Heads on a Second Generation Highly Cross-Linked Polyethylene at Mean 6-Year Follow-Up.

BACKGROUND: Bearing surface wear and osteolysis are major factors limiting the durability of total hip arthroplasty (THA). Second generation annealed highly cross-linked polyethylene (HXLPE) and ceramics were introduced to THA for their excellent wear rates. However, there is little data comparing the wear rates of metal and ceramic heads on second generation HXLPE. METHODS: Sixty patients who received a noncemented THA with a 32- or 36-mm delta ceramic head were matched with 60 THAs with a 32- or 36-mm metal head based on gender, head size, follow-up, and University of California, Los Angeles activity score. Linear and volumetric wear rates were measured. RESULTS: At mean 6-year follow-up, the mean linear wear rates were 0.012 mm/y (standard deviation [SD] 0.045; 95% confidence interval [CI] 0.001-0.024) and 0.018 mm/y (SD 0.025; 95% CI 0.012-0.025) for the ceramic and metal groups, respectively (P = .724). The mean volumetric wear rates for the ceramic and metal head groups were 11.9 (SD 43.0; 95% CI 0.7-23.0) and 17.3 (SD 23.9; 95% CI 11.1-23.4), respectively. No significant differences were detectable in either the mean linear or volumetric wear rates (P = .380 and P = .398, respectively). CONCLUSION: Second generation HXLPE had low wear rates and we were unable to detect a significant difference in wear rates with 32- or 36-mm metal and ceramic heads. We believe that this is due to the excellent tribological properties of second generation HXLPE. We continue to use ceramic as standard of care because of issues of trunnionosis with metal heads.

Clinical and Radiographic Results of Attune and PFC Sigma Knee Designs at 2-Year Follow-Up: A Prospective Matched-Pair Analysis.

BACKGROUND: Anterior knee pain (AKP) and/or crepitation are important causes of dissatisfaction after total knee arthroplasty (TKA). Aim of this prospective, matched-pair study was to compare 2 different designs of patellofemoral (ie, trochlear groove) TKA. The Attune knee has an anatomic trochlear groove with a medialized dome patellar component vs the PFC Sigma with a single radius trochlear groove with a domed shaped patella. METHODS: Between January 2010 and December 2014, 100 consecutive Attune TKAs were matched to 100 PFC Sigma TKAs based on age, gender, side, and body mass index. All surgeries were performed via medial parapatellar approach and used cemented, posterior-stabilized implants with patellar resurfacing. Clinical evaluations were assessed using Knee Society Scores (KSS) and a patient-administered questionnaire at 2-year follow-up (range, 1.5-3 years). RESULTS: Based on the KSS clinical rating system, excellent clinical results were achieved in 89.4% and 90.7% of Attune and PFC Sigma TKAs, respectively. There were no significant differences in the KS pain or function scores. The overall incidence of AKP was significantly lower with the Attune knee compared to that of the PFC Sigma (12.5% vs 25.8%; P = .02). The incidence of hearing or feeling noise was also less with the Attune knee (17.7% vs 30.9%; P = .02). The incidence of painful crepitation was low in both groups (1.0% vs 4.1%) with no significant difference between groups (P = .37). Both groups had similar high satisfaction scores of 8.6 and 8.4 for the Attune and PFC groups, respectively (P = .09). CONCLUSION: At 2-year follow-up, there were no differences between the PFC Sigma and Attune knees in KSS or satisfaction. However, the Attune group had a lesser incidence of AKP and crepitation. Further studies should focus on AKP and noise in cruciate-retaining knees.

Patient-Specific Total Knees Demonstrate a Higher Manipulation Rate Compared to "Off-the-Shelf Implants".

Patient-specific total knee replacements have been designed in hopes of providing better functional outcomes compared to "off-the-shelf" implants in primary total knee arthroplasty (TKA). We prospectively evaluated manipulation rates and clinical outcomes of 21 patient-specific TKAs matched with 42 posterior-stabilized and 11 cruciate-retaining "off-the-shelf" TKAs. Postoperatively, the patient-specific group had a range of motion significantly less than both control groups (P<0.01). Six of the 21 (28.6%) patient-specific TKAs required manipulation to improve range of motion. No manipulations were reported in either control groups. At minimum two-year follow-up the patient-specific TKAs had similar motion, but worse satisfaction and KSS pain scores. Radiographic analysis provided no insight to the cause of stiffness. Early manipulation is recommended for stiffness with patient-specific TKA.

A Comparison of Blood Metal Ions in Total Hip Arthroplasty Using Metal and Ceramic Heads.

BACKGROUND: In recent time, metal ion debris and adverse local tissue reaction have reemerged as an area of clinical concern with the use of large femoral heads after total hip arthroplasty (THA). METHODS: Between June 2014 and January 2015, 60 patients with a noncemented THA using a titanium (titanium, molybdenum, zirconium, and iron alloy) femoral stem and a V40 trunnion were identified with a minimum 5-year follow-up. All THAs had a 32- or 36-mm metal (n = 30) or ceramic (n = 30) femoral head coupled with highly cross-linked polyethylene. Cobalt, chromium, and nickel ions were measured. RESULTS: Patients with metal heads had detectable cobalt and chromium levels. Cobalt levels were detectable in 17 (56.7%) patients with a mean of 2.0 µg/L (range: <1.0-10.8 µg/L). Chromium levels were detectable in 5 (16.7%) patients with a mean of 0.3 µg/L (range: <1.0-2.2 µg/L). All patients with a ceramic head had nondetectable cobalt and chromium levels. Cobalt and chromium levels were significantly higher with metal heads compared to ceramic heads (P < .01). Cobalt levels were significantly higher with 36-mm metal heads compared with 32-mm heads (P < .01). Seven patients with metal femoral heads had mild hip symptoms, 4 of whom had positive findings of early adverse local tissue reaction on magnetic resonance imaging. All ceramic THA was asymptomatic. CONCLUSION: The incidence and magnitude of cobalt and chromium levels is higher in metal heads compared to ceramic heads with this implant system (P < .01). Thirty-six millimeter metal femoral heads result in larger levels of cobalt compared with 32-mm metal heads.

Severe Hand Osteoarthritis Strongly Correlates With Major Joint Involvement and Surgical Intervention.

BACKGROUND: The presence of hand osteoarthritis (OA) increases the risk for developing OA in other major joints. Although genetic predisposition has been implicated in its causation, its exact role has yet to be established. The association of hand OA with symptomatic and asymptomatic major joints has not been previously studied. METHODS: Hundred consecutive patients had a hand photo taken for visual documentation of the hand joints. Radiographs of hand and all major symptomatic joints were analyzed and classified using the Kellgren-Lawrence scale by 2 independent observers including an orthopedic radiologist. RESULTS: Severe hand OA was present in 91% of the patients. Radiographic analysis showed that the hip was involved in 88% of the patients, of whom 85.2% (75) were symptomatic and 14.7% (13) were asymptomatic. Hip arthroplasty was required by 62.5% (55) of symptomatic hip patients. Knee involvement was present in 37% of the patients; all were symptomatic and 81.1% (30) of these required knee arthroplasty. Bilateral surgery was performed in 33% (28) and "2 joint (hip and knee)" surgery was performed in 6% (5). Spine involvement was present in 72% of the patients. There was a significant correlation between hand radiographic findings of OA and hip (r = 0.68; P = .03), knee (r = 0.58; P = .042), and spine (r = .39; P = .05) involvement. CONCLUSION: There was a significant correlation between severe hand OA and hip, knee, and spine involvement. Severity of Hand OA can have a predictive value on multiple joint involvement and risk of surgical intervention. This study emphasizes the need to investigate the genetic predisposition in causation of OA.

Effect of Spinal Deformity on Pelvic Orientation from Standing to Sitting Position.

BACKGROUND: The effect of fixed spinal deformities on a functional pelvis from standing to sitting is not fully understood. We aimed to assess the change in preoperative sagittal pelvic tilt angle (SPTA) from standing to sitting in patients undergoing total hip arthroplasty, comparing flexible and fixed spinal deformities. METHODS: Between July 2011 and October 2011, 68 consecutive unilateral total hip arthroplasties were implanted in 68 patients with a mean age of 71 ± 6 years. Fixed spinal deformity was defined as <10° of the change in SPTA from standing to sitting. Preoperative radiographic evaluation included standing (weight-bearing) anteroposterior and lateral pelvic and lumbosacral radiographs and a sitting lateral pelvic radiograph. RESULTS: The mean standing and sitting SPTA was 3.7° of anterior tilt and 17.7° of posterior tilt, respectively (change of 21.4 ± 12.5°). Seventy-five percent had flexible pelvises, all of which had a posterior tilt from standing to sitting. One patient in the fixed pelvis (1.4%) had a loss of posterior tilt from standing to sitting. The mean change of SPTA from standing to sitting in the fixed and flexible pelvis groups was 5.9 ± 3.5° to 26.7 ± 9.6° of posterior tilt, which was statistically significant (P < .05). CONCLUSION: There was a significant change in sagittal pelvic tilt from standing to sitting, especially in patients with a flexible spine, in which the functional anteversion increases with sitting. The patients with a fixed pelvis had significantly less SPTA in standing (less anteversion) with less posterior sagittal tilt in sitting, which should be incorporated in cup positioning.

Performance of Non-Cemented, Hemispherical, Rim-Fit, Hydroxyapatite Coated Acetabular Component.

The purpose of this study was to assess the durability of a non-cemented, hemispherical rim-fit, hydroxyapatite coated cup with a highly cross-linked polyethylene in 223 total hip arthroplasties. At 6-years follow-up (range, 5-9), there were no cup revisions for osteolysis or loosening. Radiologic evidence of osseointegration was based on presence of Stress Induced Reactive Cancellous Bone and radial trabeculae, seen in 47% and 93% of cups, respectively; both were most prevalent in Zone 1. There was no interference demarcation in any zones. Two cups were revised (0.9%): one for dislocation and another for infection. The Kaplan-Meier survivorship for cup revision for any failure (infection, dislocation) was 99% and for mechanical failure (osteolysis, loosening) was 100%. This design has excellent safety, efficacy and durability.

Prospective Randomized Trial of the Efficacy of Continuous Passive Motion Post Total Knee Arthroplasty: Experience of the Hospital for Special Surgery.

Conflicting evidence has created substantial controversy regarding the use of continuous passive motion (CPM) in the in-patient setting post total knee arthroplasty (TKA). A total of 109 patients were randomly assigned to two groups, CPM or no CPM, applied after TKA. All patients received the same physical therapy protocol (3 sessions per day), with the only exception being the CPM. Both groups had a knee flexion of 115° at 6 weeks and 120° at 3 months, with no significant differences (P=0.69 and P=0.41, respectively). Length of stay was significantly less for the group who did not receive CPM. The use of CPM had no clinically relevant benefits with respect to AROM, clinical outcomes or discharge disposition and was associated with a cost of $235.50 per TKA.

Durable fixation achieved with medialized, high hip center cementless THAs for Crowe II and III dysplasia.

BACKGROUND: A high hip center total hip arthroplasty (THA) for dysplasia allows more complete socket coverage by native bone at the expense of abnormal hip biomechanics. Despite poor results with cemented components, intermediate-term results with cementless cups at a high hip center have been promising, but there are few reports at long-term followup without bone graft. QUESTIONS/PURPOSES: The purpose of this study was to examine (1) survivorship; 2) radiographic results; and 3) hip scores at a minimum of 10 years for patients treated with high hip center cementless THA for Crowe II and III dysplasia without bone graft. METHODS: We reviewed charts and radiographs of 32 patients with Crowe II or III dysplasia who were treated with high hip center cementless THA; at a mean followup of 12 years (range, 10-21 years), 23 patients (27 hips) were available for review. We sought to medialize cups to the inner table to achieve bony coverage of > 75%. At final followup, the WOMAC and Harris hip scores were recorded. Radiographic analysis including computerized wear evaluation was performed. Radiographic parameters were compared with a control group of 23 patients with Crowe I dysplasia who had cementless cups placed at an anatomic hip center; among the high hip center reconstructions, we also compared wear between those in the superolateral and superomedial quadrants. RESULTS: Kaplan-Meier survivorship for all-cause revisions was 97% (95% confidence interval, 79%-99%) in the high hip center group; this was no different from the anatomic hip center group. There were no revisions for acetabular loosening. Wear rates did not differ significantly between the high hip center and the control group, but lateralized high hip centers were associated with higher (p = 0.002) wear. Hip scores were excellent in both groups. CONCLUSIONS: In Crowe II and III dysplasia, a high hip center cementless cup obviates the need for bone graft and provides durable fixation beyond 10 years. Medialization of these reconstructions seems important to decrease wear.

Does the direct anterior approach in THA offer faster rehabilitation and comparable safety to the posterior approach?

BACKGROUND: Newer surgical approaches to THA, such as the direct anterior approach, may influence a patient's time to recovery, but it is important to make sure that these approaches do not compromise reconstructive safety or accuracy. QUESTIONS/PURPOSES: We compared the direct anterior approach and conventional posterior approach in terms of (1) recovery of hip function after primary THA, (2) general health outcomes, (3) operative time and surgical complications, and (4) accuracy of component placement. METHODS: In this prospective, comparative, nonrandomized study of 120 patients (60 direct anterior THA, 60 posterior THAs), we assessed functional recovery using the VAS pain score, timed up and go (TUG) test, motor component of the Functional Independence Measure™ (M-FIM™), UCLA activity score, Harris hip score, and patient-maintained subjective milestone diary and general health outcome using SF-12 scores. Operative time, complications, and component placement were also compared. RESULTS: Functional recovery was faster in patients with the direct anterior approach on the basis of TUG and M-FIM™ up to 2 weeks; no differences were found in terms of the other metrics we used, and no differences were observed between groups beyond 6 weeks. General health outcomes, operative time, and complications were similar between groups. No clinically important differences were observed in terms of implant alignment. CONCLUSIONS: We observed very modest functional advantages early in recovery after direct anterior THA compared to posterior-approach THA. Randomized trials are needed to validate these findings, and these findings may not generalize well to lower-volume practice settings or to surgeons earlier in the learning curve of direct anterior THA.

Reproducible fixation with a tapered, fluted, modular, titanium stem in revision hip arthroplasty at 8-15 years follow-up.

The use of tapered, fluted, modular, distally fixing stems has increased in femoral revision surgery. The goal of this retrospective study was to assess mid-term to long-term outcomes of this implant. Seventy-one hips in 70 patients with a mean age of 69 years were followed for an average of 10 years. Preoperative HHS averaged 50 and improved to 87 postoperatively. Seventy-nine percent hips had Paprosky type 3A or more bone-loss. All stems osseointegrated distally (100%). Two hips subsided >5mm but achieved secondary stability. Sixty-eight percent hips had evidence of bony reconstitution and 21% demonstrated diaphyseal stress-shielding. One stem fractured near its modular junction and was revised with a mechanical failure rate of 1.4%. Distal fixation and clinical improvement were reproducibly achieved with this stem design.

A novel method for accurate and reproducible functional cup positioning in total hip arthroplasty.

Cup positioning is an important variable for short and long term function, stability, and durability of total hip arthroplasty (THA). This novel method utilizes internal and external bony landmarks, and the transverse acetabular ligament for positioning the acetabular component. The cup is placed parallel and superior to the transverse ligament and inside the anterior wall notch of the true acetabulum, then adjusted for femoral version and pelvic tilt and obliquity based on weight bearing radiographs. In 78 consecutive THAs, the mean functional anteversion and abduction angles were 17.9° ± 4.7° and 41.7° ± 3.8°, respectively. 96% of the functional anteversion measurements and 100% of the functional abduction angles were within the safe zone. This technique is an easy, reproducible, and accurate method for functional cup placement.