The Future is Non-cemented Total Knee Arthroplasty: Volume Trends at the Hospital for Special Surgery

INTRODUCTION

The optimal fixation method for total knee arthroplasty (TKA) is still a debate. Cemented fixation has excellent long-term results and is the gold standard. However, longevity in the younger, heavier, and more active population is suboptimal. Cementless TKA offers the opportunity to gain biological fixation and overcome these shortcomings.

METHODS

This is a retrospective review of all consecutive cementless TKA procedures performed at a single academic institution from 2016 until 2020. Demographics, aseptic revisions, and septic revisions were pulled from the electronic medical record. The number of yearly implanted cementless TKA prosthesis was determined to analyze utilization trends.

RESULTS

Eight-hundred and two patients were identified with a mean age of 61.57 ± 7.78 years, and a mean of BMI 32.12 ± 5.98 kg/m². The mean time to revision was 12.31 ± 13.91 months. There were four septic failures and nine aseptic failures during the study period. Of these nine aseptic failures only five were due to mechanical loosening. There was a yearly linear increase in the use of cementless fixation.

CONCLUSION

Cementless fixation is here to stay, and its use will continue to increase. Early and mid-term outcomes have been excellent thus far. Changing clinical practice takes time but we have already seen this transition take place in total hip arthroplasty. As technology and design continue to evolve, we believe it is a possibility.

Improved Sexual Function After Total Hip and Knee Arthroplasty for Osteoarthritis

Osteoarthritis of the hip and knee is known to affect sexual activity. For patients with osteoarthritis, pain during sexual activity can lead to decreased quality of life and other associated health issues. The authors designed a prospective study to evaluate the effect of total hip arthroplasty and total knee arthroplasty on the psychosocial and physical aspects of sexuality pre- and postoperatively. Between April 2009 and December 2011, patients received questionnaires in the mail preoperatively. They were asked to return the preoperative questionnaire before surgery and the postoperative questionnaire 6 months after surgery. Data were analyzed to evaluate the psychosocial and physical aspects of sexuality and participants' subjective assessment of their appearance. Preoperatively, 91% and 67% of patients reported psychosocial and physical issues, respectively. After the arthroplasty procedure, 84% (P<.001) and 47% (P<.001) of patients reported improvement psychosocially and physically, respectively. Of the patients, 16% reported that arthroplasty adversely affected sexual function, with their predominant fear being joint damage (63%). A greater number of women and patients undergoing hip procedures reported improvement in sexual activity after surgery compared with men (P=.02) and patients undergoing knee procedures (P=.002). Both hip and knee osteoarthritis and arthroplasty had a significant effect on overall sexual function-psychosocially, physically, and in terms of patients' assessment of their external appearance-with higher rates of improvement seen after hip arthroplasty. Because of the effect of osteoarthritis and arthroplasty on sexual function, this topic should be addressed both pre- and postoperatively. [Orthopedics. 2021;44(2):111-116.].

Soft-Tissue Balancing Technology for Total Knee Arthroplasty

» Improperly balanced total knee arthroplasties are at increased risk for complications including residual pain and/or instability, which are often corrected by a revision surgical procedure. » Because of the morbidity and financial burden associated with revision total knee arthroplasty, different technological applications, such as tibial insert sensors and computer-assisted gap balancing, are being used to assist with soft-tissue balancing during primary total knee arthroplasty. » Computer-assisted gap balancing increases the accuracy of mechanical alignment and improves the precision of balancing flexion and extension gaps during total knee arthroplasty. It is unclear whether this translates to improved short-term or long-term outcome measures. Considerations of this technology include increased cost, increased operative time, and a steep learning curve. » Intraoperative sensors increase the accuracy of balancing by quantifying the mediolateral intercompartmental load distribution through the range of motion, which may lead to improved outcome scores, patient satisfaction, higher activity levels, and decreased pain. The advantages of this technology compared with computer assistance include decreased cost and no disruption of operative time or workflow. Limited availability with constrained implants, limited implant choices, and a lack of long-term follow-up data have reduced utilization of intraoperative sensors. » Computer-assisted gap balancing and intraoperative sensors are not yet universally accepted, and the cost-benefit ratio associated with their use remains a consideration in today’s cost-conscious health-care environment. Future research should focus on longer-term follow-up to evaluate implant survivorship, cost-effectiveness, and clinical outcomes.

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.

Early failure of a modern moderately cross-linked polyethylene acetabular liner

Modern polyethylene components for total hip arthroplasty have shown excellent long-term wear properties. However, among 204 primary total hip arthroplasty procedures performed by one surgeon using the Exactech Connexion GXL Liner, we identified 5 cases of severe polyethylene wear and osteolysis which occurred within 5 years of the index surgery. Among the 5 cases, all patients had a size 36 head with an acetabular component from size 52 to 56 mm. All patients had a UCLA activity scale score of at least 6 at the time that the osteolysis was detected. The average wear rate was 0.265 mm ± 0.207 mm per year. This review of 5 cases of catastrophic early polyethylene wear demonstrates a concerning trend with the use of the Exactech Connexion GXL liner. Further investigation is warranted to evaluate material characteristics which may have caused this accelerated wear and to prevent recurrences of this complication in the future.

A comparison of clinical and patient-reported outcome measures of TKR: Comparison of Asian to North American patients

BACKGROUND

Cultural differences between continents may also affect the outcome on interventions. This study compared an Asian and North American cohort of total knee replacement (TKR) patients.

QUESTIONS/PURPOSES

This study aims to compare the patient-reported outcome measures as well as a functional outcome after TKR between these two different patient populations with a different cultural societal background in two different countries.

PATIENTS AND METHODS

A retrospective study on two cohorts of 76 Asian TKR patients and 64 North American TKR patients were compared. Demographics, patient-reported outcome measures (Knee Society Score (KSS), Patient-Administered Questionnaire (PAQ), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)), knee range of motion (RoM), and radiographic component position were compared.

RESULTS

The Asian cohort had more females compared to the North American and significantly worse preoperative RoM, and worse KSS function score and PAQ pain scores. The preoperative KSS knee score and WOMAC scores were comparable between the two groups. Postoperatively, the differences in WOMAC and KSS knee scores were significant, while KSS function and PAQ were comparable between groups.

CONCLUSIONS

Even though Asian TKR patients had significantly worse preoperative scores, their postoperative outcomes were comparable to North Americans. The higher preoperative functional deficit and the higher pain levels in the Asian population might be due to cultural differences and/or socioeconomic reasons, which made Asian patients present with more severe conditions in the preoperative consultation for a possible surgical treatment compared to North Americans. More research is needed to investigate the difference between these cultural impacts on TKR outcomes.

LEVEL OF EVIDENCE

Level III/Retrospective cohort study.

Increased utilization of constraint in total knee arthroplasty following anterior cruciate ligament and multiligament knee reconstruction

Aims

Anterior cruciate ligament (ACL) and multiligament knee (MLK) injuries increase the risk of development of knee osteoarthritis and eventual need for total knee arthroplasty (TKA). There are limited data regarding implant use and outcomes in these patients. The aim of this study was to compare the use of constrained implants and outcomes among patients undergoing TKA with a history of prior knee ligament reconstruction (PKLR) versus a matched cohort of patients undergoing TKA with no history of PKLR.

Patients and Methods

Patients with a history of ACL or MLK reconstruction who underwent TKA between 2007 and 2017 were identified in a single-institution registry. There were 223 patients who met inclusion criteria (188 ACL reconstruction patients, 35 MLK reconstruction patients). A matched cohort, also of 223 patients, was identified based on patient age, body mass index (BMI), sex, and year of surgery. There were 144 male patients and 79 female patients in both cohorts. Mean age at the time of TKA was 57.2 years (31 to 88). Mean BMI was 29.7 kg/m2 (19.5 to 55.7).

Results

There was a significantly higher use of constrained implants among patients with PKLR (76 of 223, 34.1%) compared with the control group (40 of 223, 17.9%; p < 0.001). Subgroup analysis showed a higher use of constrained implants among patients with prior MLK reconstruction (21 of 35, 60.0%) compared with ACL reconstruction (55 of 188, 29.3%; p < 0.001). Removal of hardware was performed in 69.5% of patients with PKLR. Mean operative time (p < 0.001) and tourniquet time (p < 0.001) were longer in patients with PKLR compared with controls. There were no significant differences in rates of deep vein thrombosis, pulmonary embolism, infection, transfusion, postoperative knee range of movement (ROM), or need for revision surgery. There was no significant difference in preoperative or postoperative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) scores between groups.

Conclusion

Results of this study suggest a history of PKLR results in increased use of constrained implants but no difference in postoperative knee ROM, patient-reported outcomes, or incidence of revision surgery. Cite this article: Bone Joint J 2019;101-B(7 Supple C):77–83

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.

Addition of Adductor Canal Block to Periarticular Injection for Total Knee Replacement: A Randomized Trial

BACKGROUND

Periarticular injection is a popular method to control postoperative pain after total knee replacement. An adductor canal block is a sensory block that can also help to alleviate pain after total knee replacement. We hypothesized that the combination of adductor canal block and periarticular injection would allow patients to reach discharge criteria 0.5 day faster than with periarticular injection alone.

METHODS

This prospective trial enrolled 56 patients to receive a periarticular injection and 55 patients to receive an adductor canal block and periarticular injection. Both groups received intraoperative neuraxial anesthesia and multiple different types of pharmaceutical analgesics. The primary outcome was time to reach discharge criteria. Secondary outcomes, collected on postoperative days 1 and 2, included numeric rating scale pain scores, the PAIN OUT questionnaire, opioid consumption, and opioid-related side effects.

RESULTS

There was no difference in time to reach discharge criteria between the groups with and without an adductor canal block. The Wilcoxon-Mann-Whitney odds ratio was 0.87 (95% confidence interval [CI], 0.55 to 1.33; p = 0.518). The median time to achieve discharge criteria (and interquartile range) was 25.8 hours (23.4 hours, 44.3 hours) in the adductor canal block and periarticular injection group compared with 26.4 hours (22.9 hours, 46.2 hours) in the periarticular injection group. Patients who received an adductor canal block and periarticular injection reported lower worst pain (difference in means, -1.4 [99% CI, -2.7 to 0]; adjusted p = 0.041) and more pain relief (difference in means, 12% [99% CI, 0% to 24%]; adjusted p = 0.048) at 24 hours after anesthesia. There was no difference in any other secondary outcome measure (e.g., opioid consumption, opioid-related side effects, numeric rating scale pain scores).

CONCLUSIONS

The time to meet the discharge criteria was not significantly different between the groups. In the adductor canal block and periarticular injection group, the patients had lower worst pain and greater pain relief at 24 hours after anesthesia. No difference was noted in any other secondary outcome measure (e.g., opioid consumption, opioid-related side effects, numeric rating scale pain scores).

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

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.

Patients Discharged to Inpatient Rehabilitation Facilities Undergo More Diagnostic Interventions With No Improvement in Outcomes

The purpose of this study was to determine if there is a difference in the number of diagnostic tests and interventions, pain and function scores, or satisfaction of patients discharged to inpatient rehabilitation facilities vs to home. From February to May 2015, 171 consecutive patients were prospectively recruited following primary total knee arthroplasty. Six weeks postoperatively, based on the patients' recollections, the number and types of diagnostic imaging tests, number of blood transfusions, and overall satisfaction whether discharged to inpatient rehabilitation facilities (n=85) or to home (n=86) were assessed. A significantly greater proportion of patients discharged to inpatient rehabilitation facilities reported undergoing at least 1 diagnostic imaging test compared with patients discharged to home (25.9% vs 8.1%; P=.013). Multivariate logistic regressions revealed that patients discharged to an inpatient rehabilitation facility were more likely to have a greater number of diagnostic tests (odds ratio, 5.01; 95% confidence interval, 1.69-14.92; P=.004) and radiographs (odds ratio, 16.10; 95% confidence interval, 1.54-169.70; P=.020) performed. There was no significant difference in readmission rates for patients discharged to home (2.3%) vs to an inpatient rehabilitation facility (0%) (P=.246). No significant differences were observed in postoperative Knee Society pain or function scores (P=.083 and P=.057, respectively) or visual analog scale satisfaction scores (P=.206). Twenty-nine (34.1%) patients were discharged under the care of the visiting nurse service after leaving the rehabilitation facility. Patients discharged to an inpatient rehabilitation facility underwent more diagnostic testing, especially radiographs, than patients discharged to home. There were no clinically relevant differences in Knee Society pain or function scores or patient satisfaction. [Orthopedics. 2018; 41(6):e841-e847.].

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.

Incidence of Heterotopic Ossification Following a Multimodal Pain Protocol in Total Hip Arthroplasty With the Posterior Approach

Heterotopic ossification (HO) is prevalent after total hip arthroplasty (THA). Oral nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 (COX-2) inhibitors have reduced the incidence of HO; however, to the authors' knowledge, no studies have reported the incidence and severity of HO with a pain protocol highlighted by celecoxib in the pre- and postoperative period with a posterolateral approach. Between October 2014 and October 2015, a retrospective study was conducted of 687 consecutive primary THAs with minimum 1-year follow-up performed between January 2009 and December 2013. All patients underwent a posterolateral THA with a multimodal pain protocol consisting of preoperative celecoxib; local steroid infiltration intraoperatively; postoperative celecoxib, dexamethasone, and ketorolac; and aspirin or warfarin thromboprophylaxis. For all patients, pre- and postoperative radiographs were examined and classified for HO using the Brooker classification. Interobserver reliability was calculated for both incidence of HO and Brooker classification. Overall, HO was present around 98 (14.3%) THAs. The incidence of Brooker I, II, and III HO was 38 (5.5%), 47 (6.8%), and 12 (1.7%), respectively. No patients required surgical excision or had radiographic evidence of Brooker IV HO. Multivariate logistic regression identified male sex and hypertrophic osteoarthritis as significant risk factors. The use of aspirin for thromboprophylaxis significantly reduced the incidence of HO. This study found the overall incidence of HO when using celecoxib during a posterior THA to be 14.3%, which is similar to what others have reported with the direct lateral approach and with other COX-2 inhibitors for a posterior approach. Risk factors include male sex and preoperative hypertrophic osteoarthritis. [Orthopedics. 2018; 41(1):e92-e97.].

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.

Long-term Results of a First-Generation Annealed Highly Cross-Linked Polyethylene in Young, Active Patients

The survivorship of total hip arthroplasty in younger patients is dependent on the wear characteristics of the bearing surfaces. Long-term results with conventional polyethylene in young patients show a high failure rate. This study assessed the long-term results of a first-generation annealed highly cross-linked polyethylene (HCLPE) in uncemented total hip arthroplasty in young, active patients. Between 1999 and 2003, 112 total hip arthroplasty procedures performed in 91 patients with an average University of California Los Angeles activity score of 8 and mean age of 53 years (range, 24-65 years) were included from a prospective database. In all patients, a 28-mm metal femoral head on annealed HCLPE (Crossfire; Stryker, Mahwah, New Jersey) was used. At minimum 10-year follow-up (11.5±0.94 years), Kaplan-Meier survivorship was 97% for all failures (1 periprosthetic infection and 1 late dislocation) and 100% for mechanical failure (no revisions for osteolysis or loosening). This study showed low revision rates for wear-related failure and superior survivorship in young, active patients. Oxidation causing failure of the locking mechanism has not been a problem with Crossfire for up to 10 years.

Diagnostic Algorithm for Residual Pain After Total Knee Arthroplasty

Although total knee arthroplasty is a successful and cost-effective procedure, patient dissatisfaction remains as high as 50%. Postoperative residual knee pain after total knee arthroplasty, with or without crepitation, is a major factor that contributes to patient dissatisfaction. The most common location for residual pain after total knee arthroplasty is anteriorly. Because residual pain has been associated with an un-resurfaced patella, this review includes only registry data and total knee arthroplasty with patella replacement. Some suggest that the pathogenesis of residual knee pain may be related to mechanical stimuli that activate free nerve endings around the patellofemoral joint. Various etiologies have been implicated in residual pain, including (1) low-grade infection, (2) midflexion instability, and (3) component malalignment with patellar maltracking. Less common causes include (4) crepitation and patellar clunk syndrome; (5) patellofemoral symptoms, including overstuffing and avascular necrosis of the patella; (6) early aseptic loosening; (7) hypersensitivity to metal or cement; (8) complex regional pain syndrome; and (9) pseudoaneurysm. Because all of these conditions can lead to residual pain, identifying the etiology can be a difficult diagnostic challenge. Often, patients with persistent pain and normal findings on radiographs and laboratory workup may benefit from a diagnostic injection or further imaging. However, up to 10% to 15% of patients with residual pain may have unexplained pain. This literature review summarizes the findings on the causes of residual pain and presents a diagnostic algorithm to facilitate an accurate diagnosis for residual pain after total knee arthroplasty.

Management of Resistant, Atypical and Culture-negative Periprosthetic Joint Infections after Hip and Knee Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication following lower extremity total joint arthroplasty (TJA). It is a leading cause of morbidity and revision following TJA. As such, PJI is a significant driver of healthcare costs. The prevalence of PJI related to resistant and atypical organisms is increasing, and approximately 10-30% of PJIs are culture-negative. The purpose of this review is to summarize the current epidemiology, diagnostics, and management of PJI associated with resistant and atypical pathogens and of culture-negative PJIs.

METHODS

The published literature related to the epidemiology, diagnosis, and management of atypical, drug-resistant, and culture-negative PJI is reviewed.

RESULTS

The clinical diagnosis of PJI is often challenging, particularly when pathogens are fastidious or when antibiotics have been administered empirically. Molecular diagnostic studies, such as synovial α-defensin, may provide rapid, accurate identification of PJI, even in the setting of concurrent antibiotics administration or systemic inflammatory disease. Once PJI is diagnosed, two-stage exchange arthroplasty remains the gold standard for treating PJI with resistant microorganisms, since there is a high rate of treatment failure with irrigation and debridement and with one-stage exchange arthroplasty.

CONCLUSION

Additional research is needed to define the optimal treatment of PJIs associated with rare pathogens, such as fungi and mycobacteria. There is a need for inexpensive, reliable tests that rapidly detect specific microbial species and antimicrobial susceptibilities. Additional research is also required to define the specific organisms, clinical scenarios, surgical techniques, and antimicrobial regimens that allow for reproducible treatment success with prosthetic retention strategies.

Use of Oversized Highly Porous Cups in Acetabular Revision

This study assessed the efficacy of highly porous cups in revision total hip arthroplasty for Paprosky types II and III acetabular bone loss. The authors identified 33 acetabular revisions in 29 patients from a prospective database (66% type III, 7 with pelvic dissociation). Initial stability was achieved with interference fit between the anterior inferior iliac spine, pubis, and ischium with cups that were 2 to 4 mm larger than the reamed acetabulum and augmented with multiple screw fixations without allograft or wedges. At mean follow-up of 6 years (range, 2.7-7.7 years) after revision surgery, no dislocation, infection, or reoperation was noted. Mean satisfaction score was 6±3.2. Mean anteversion and abduction angles were 43°±4.6° and 21.5°±4.4°, respectively. Complications included limp in 13% of patients, wound issues in 10%, and heterotopic ossification in 17%. Osteointegration was seen in all cups, without any migration. Mean overall osteointegration, based on the average percentage of the 3 zones in both views, was 55%±21% (range, 25%-95%). The most osteointegration was seen in zone I (superior) and zone VI (posterior), and the least osseointegration was seen in zone II (medial) and zone IV (anterior). This method can provide reproducible results in acetabular revision arthroplasty.

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.

Long-term results of total knee arthroplasty in young and active patients with posterior stabilized design

BACKGROUND

The aim of this study was to evaluate long-term quality and performance of cemented posterior-stabilized (PS) total knee arthroplasty (TKA) in young and active patients with gap balancing technique.

METHODS

Between January 2000 and October 2001, 55 TKAs (21 rotating platform [RP] and 34 fixed bearing [FB]) in 41 patients, 60 years and younger, with University of California Los Angeles (UCLA) activity score of five and above were included in this study and prospectively followed. Clinical assessments included Western Ontario and McMaster Universities (WOMAC), Knee Society, UCLA activity score, and Patient Administered Questionnaire (PAQ). Radiographic measurements included component positioning, patellar tilt and thickness, radiolucency, loosening or osteolysis.

RESULTS

At a mean follow-up of 12.3±0.5 years (11 to 13), there was no instability, malalignment, or patellofemoral maltracking. Sixty eight percent of patients were still participating in regular recreational activities at the final follow-up. The mean satisfaction score was 9.1±1.9 and 8.5±2.1 in RP-PS and FB-PS groups, respectively. There was no malalignment or osteolysis, no revision for osteolysis or loosening. One patient in the FB-PS group underwent open reduction and internal fixation for a peri-prosthetic fracture. Overall Kaplan-Meier survivorship was 98%.

CONCLUSION

The PS TKA in young and active patients can provide long-term durability and high quality of function.

LEVEL OF EVIDENCE

III.

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.

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.

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.

Stem length in revision total knee arthroplasty

Stems are intramedullary extensions of either the femoral or tibial component of a total knee arthroplasty (TKA) designed to increase the mechanical stability to decrease the risk of aseptic loosening. Biomechanical studies have shown that TKA stems increase the mechanical stability by transferring load over a larger area and thereby reduce strain at the bone-component interface [1-4]. The length of a revision TKA stem is determined by the patient's anatomy and the intended fixation, namely fully cemented or press-fit cortical contact. The advantages and disadvantages of various stem lengths must be weighed against the needs of the patient to achieve an optimal outcome.

Fixed Bearings versus Rotating Platforms in Total Knee Arthroplasty

Rotating platforms were introduced as an alternative to fixed bearings in hopes of providing more natural kinematics and improved clinical outcomes. In-vitro wear studies showed significantly less wear with rotating platforms as opposed to fixed-bearing designs. Kinematic follow-up studies showed significantly improved axial rotation with rotating-platform knees. However, these benefits have failed to translate into improved clinical outcomes or survivorship. This article reviews our institution's experience, as well as the latest clinical research on wear, kinematics, clinical outcomes, and survivorship of fixed-bearing and rotating-platform knees.

Pregabalin and pain after total knee arthroplasty: a double-blind, randomized, placebo-controlled, multidose trial

BACKGROUND

Pregabalin may reduce postoperative pain and opioid use. Higher doses may be more effective, but may cause sedation and confusion. This prospective, randomized, blinded, placebo-controlled study tested the hypothesis that pregabalin reduces pain at 2 weeks after total knee arthroplasty, but increases drowsiness and confusion.

METHODS

Patients (30 per group) received capsules containing pregabalin (0, 50, 100, or 150 mg); two capsules before surgery, one capsule twice a day until postoperative day (POD) 14, one on POD15, and one on POD16. Multimodal analgesia included femoral nerve block, epidural analgesia, oxycodone-paracetamol, and meloxicam. The primary outcome was pain with flexion (POD14).

RESULTS

Pregabalin did not reduce pain at rest, with ambulation, or with flexion at 2 weeks (P=0.69, 0.23, and 0.90, respectively). Pregabalin increased POD1 drowsiness (34.5, 37.9, 55.2, and 58.6% in the 0, 50, 100, and 150 mg arms, respectively; P=0.030), but did not increase confusion (0, 3.5, 0, and 3.5%, respectively; P=0.75). Pregabalin had no effect on acute or chronic pain, opioid consumption, or analgesic side-effects. Pregabalin reduced POD14 patient satisfaction [1-10 scale, median (first quartile, third quartile): 9 (8, 10), 8 (7, 10), 8 (5, 9), and 8 (6, 9.3), respectively; P=0.023). Protocol compliance was 63% by POD14 (50.0, 70.0, 76.7, and 56.7% compliance, respectively), with no effect of dose on compliance. Per-protocol analysis of compliant patients showed no effect of pregabalin on pain scores.

CONCLUSIONS

Pregabalin had no beneficial effects, but increased sedation and decreased patient satisfaction. This study does not support routine perioperative pregabalin for total knee arthroplasty patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: http://www.clinicaltrials.gov/ct2/show/study/NCT01333956.

Patient-controlled epidural analgesia or multimodal pain regimen with periarticular injection after total hip arthroplasty: a randomized, double-blind, placebo-controlled study

BACKGROUND

The optimal postoperative analgesia after primary total hip arthroplasty remains in question. This randomized, double-blind, placebo-controlled study compared the use of patient-controlled epidural analgesia (PCEA) with use of a multimodal pain regimen including periarticular injection (PAI). We hypothesized that PAI would lead to earlier readiness for discharge, decreased opioid consumption, and lower pain scores.

METHODS

Forty-one patients received PAI, and forty-three patients received PCEA. Preoperatively, both groups were administered dexamethasone (6 mg, orally). The PAI group received a clonidine patch and sustained-release oxycodone (10 mg), while the PCEA group had placebo. Both groups received combined spinal-epidural anesthesia and used an epidural pain pump postoperatively; the PAI group had normal saline solution, while the PCEA group had bupivacaine and hydromorphone. The primary outcome, readiness for discharge, required the discontinuation of the epidural, a pain score of <4 (numeric rating scale) without parenteral narcotics, normal eating, minimal nausea, urination without a catheter, a dry surgical wound, no acute medical problems, and the ability to independently transfer and walk 12.2 m (40 ft).

RESULTS

The mean time to readiness for discharge (and standard deviation) was 2.4 ± 0.7 days (PAI) compared with 2.3 ± 0.8 days (PCEA) (p = 0.86). The mean length of stay was 3.0 ± 0.8 days (PAI) compared with 3.1 ± 0.7 days (PCEA) (p = 0.46). A significant mean difference in pain score of 0.74 with ambulation (p = 0.01; 95% confidence interval [CI], 0.18 to 1.31) and 0.80 during physical therapy (p = 0.03; 95% CI, 0.09 to 1.51) favored the PCEA group. The mean opioid consumption (oral morphine equivalents in milligrams) was significantly higher in the PAI group on postoperative day 0 (43 ± 21 compared with 28 ± 23; p = 0.002) and postoperative days 0 through 2 (136 ± 59 compared with 90 ± 79; p = 0.004). Opioid-Related Symptom Distress Scale (ORSDS) composite scores for severity and bothersomeness as well as scores for nausea, vomiting, and itchiness were significantly higher in the PCEA group (p < 0.05). Quality of Recovery-40 scores and patient satisfaction were similar.

CONCLUSIONS

PAI did not decrease the time to discharge and was associated with higher pain scores and greater opioid consumption but lower ORSDS scores compared with PCEA. The choice for analgesic regimen may depend on a particular patient's threshold for pain and the potential side effects.

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.

The impact of blood management on length of stay after primary total knee arthroplasty

The current study investigates the impact of patient factors, surgical factors, and blood management on postoperative length of stay (LOS) in 516 patients who underwent primary total knee arthroplasty. Age, gender, type of anticoagulation, but not body mass index (BMI) were found to be highly significant predictors of an increased LOS. Allogeneic transfusion and the number of allogeneic units significantly increased LOS, whereas donation and/or transfusion of autologous blood did not. Hemoglobin levels preoperatively until 48 hours postoperatively were negatively correlated with LOS. After adjusting for confounding factors through Poisson regression, age (p = 0.001) and allogeneic blood transfusion (p = 0.002) were the most significant determinants of LOS. Avoiding allogeneic blood plays an essential role in reducing the overall length of stay after primary total knee arthroplasty.

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.

Assessment of reactive synovitis in rotating-platform posterior-stabilized design: a 10-year prospective matched-pair MRI study

This is the first long-term (mean 11.6 years), prospective, matched-pair study (based on age, gender, BMI and UCLA scores) using MAVRIC (multi-acquisition variable-resonance image combination) magnetic resonance imaging to analyze reactive synovitis and osteolysis between rotating-platform posterior-stabilized (RP-PS), fixed-bearing metal-back (FB-MB), and all-polyethylene tibial (APT) in active patients (24 total, 8 in each group, mean age of 64 years, mean UCLA of 8.5) with identical femoral component and polyethylene. Reactive synovitis was observed in 6 RP-PS (75%), all 8 FB-MB (100%), and 6 APT (75%). There was a significant difference between the RP-PS and FB-MB knees in volumetric synovitis (P=0.023). Osteolysis with bone loss more than 4mm was seen in 3 FB-MB, 2 APT and none for RP-PS. These were not statistically significant.

Safety and efficacy of non-cemented femoral fixation in patients 75 years of age and older

The aim of this study was to assess peri-operative complications, safety and efficacy of non-cemented femoral fixation in total hip arthroplasty (THA) as compared to cemented femoral fixation in the elderly population. Fifty-two matched pair analysis of patients with 75 years of age and older (104 patients), who underwent primary THA from June 1997 to December 2004, was performed based on age, sex, BMI, and Charnley classification. Mean age was 81 years (75-101) and the average follow up was 3.1 ± 2.9 years (1.2-6.4). There was no difference in peri-operative cardiopulmonary complications, pulmonary failures, deep venous thrombosis, pulmonary embolus, length of stay, or discharge deposition between the two groups. Non-cemented fixation is safe and effective in patients older than 75 years of age.

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.

Long-term performance of ceramic and metal femoral heads on conventional polyethylene in young and active patients: a matched-pair analysis

BACKGROUND

Ceramic femoral heads produce less wear of the opposing polyethylene than do metal femoral heads in wear simulation studies. This is a matched-pair analysis of the wear of ceramic and metal femoral heads on conventional polyethylene in uncemented total hip replacements in young, active patients at a minimum of fifteen years of follow-up.

METHODS

From June 1989 to May 1992, thirty-one matched pairs of alumina ceramic or cobalt-chromium metal femoral heads were identified. Patients were matched on the basis of age, sex, body weight, diagnosis, and activity level. The mean age was 55 ± 9 years (range, twenty-three to sixty-five years) at the time of surgery. All procedures were performed with a posterolateral surgical approach by a single surgeon using press-fit Ranawat-Bernstein femoral stems, Harris-Galante-II acetabular cups, GUR 4150 conventional polyethylene (sterilized in argon), and 28-mm-diameter femoral heads. Wear measurements were performed by two independent observers using the computer-assisted Roman software.

RESULTS

The average duration of follow-up was 17 ± 1.7 years (range, fifteen to twenty years). The mean Hospital for Special Surgery hip scores (and standard deviation) in the ceramic and metal groups were 39 ± 4 and 40 ± 3 at the time of final follow-up. The University of California Los Angeles activity score at the time of the final follow-up was 6 ± 2 for both groups. The mean wear rates for the ceramic group and the metal group were 0.086 ± 0.05 mm/yr and 0.137 ± 0.05 mm/yr, respectively (p = 0.0015). There was one reoperation in the ceramic group because of distal femoral osteolysis. There were three failures in the metal group, requiring isolated liner exchange in two hips and revision of the acetabular component in one hip because of wear-induced osteolysis and/or loosening that caused symptoms. Five hips in the ceramic group and six hips in the metal group had radiographic evidence of acetabular or femoral osteolysis, but none were symptomatic.

CONCLUSIONS

Ceramic femoral heads produced significantly less wear on conventional polyethylene liners at the time of long-term follow-up than did metal heads in this matched-pair analysis of young and active patients with uncemented fixation.

Analgesia after total knee replacement: local infiltration versus epidural combined with a femoral nerve blockade: a prospective, randomised pragmatic trial

In a randomised controlled pragmatic trial we investigated whether local infiltration analgesia would result in earlier readiness for discharge from hospital after total knee replacement (TKR) than patient-controlled epidural analgesia (PCEA) plus femoral nerve block. A total of 45 patients with a mean age of 65 years (49 to 81) received a local infiltration with a peri-articular injection of bupivacaine, morphine and methylprednisolone, as well as adjuvant analgesics. In 45 PCEA+femoral nerve blockade patients with a mean age of 67 years (50 to 84), analgesia included a bupivacaine nerve block, bupivacaine/hydromorphone PCEA, and adjuvant analgesics. The mean time until ready for discharge was 3.2 days (1 to 14) in the local infiltration group and 3.2 days (1.8 to 7.0) in the PCEA+femoral nerve blockade group. The mean pain scores for patients receiving local infiltration were higher when walking (p = 0.0084), but there were no statistically significant differences at rest. The mean opioid consumption was higher in those receiving local infiltration. The choice between these two analgesic pathways should not be made on the basis of time to discharge after surgery. Most secondary outcomes were similar, but PCEA+femoral nerve blockade patients had lower pain scores when walking and during continuous passive movement. If PCEA+femoral nerve blockade is not readily available, local infiltration provides similar length of stay and similar pain scores at rest following TKR.

Haptically guided robotic technology in total hip arthroplasty: a cadaveric investigation

The longevity of total hip arthroplasty (THA) continues to improve with advancements in design and bearing materials. However, the incidence of dislocation and impingement-related failures continue to rise, with the inability of the surgeon to achieve optimal component orientation cited as a cause. Computer-assistance has been shown to increase the accuracy of component orientation and robotic-assistance has been developed to translate this advantage into precise surgical execution. We sought to validate a haptically-guided robotic arm system in performing THA with the aim of comparing the accuracy of robotic-assisted acetabular cup placement to manual placement. We implanted 12 acetabular components in 6 cadaveric pelvises comparing robotic-assistance on one side with manual implantation on the other. We measured planned and actual center of rotation (COR), cup position, leg-length equalization and offset for each THA using computed tomography and the robotic platform. The root-mean-square (RMS) error for the robotic-assisted system was within 3 degrees for cup placement and within 1 mm for leg-length equalization and offset when compared to computed tomography. The robotic-assisted system was significantly more accurate than manual implantation in reproducing the COR and cup orientation, as determined by a preoperative plan. The RMS error for manual implantation compared to robotic-assistance was 5 times higher for cup inclination and 3.4 times higher for cup anteversion (p < 0.01). Robotic-assistance is more accurate than manual implantation in achieving optimal cup orientation. It has the ability to eliminate human error from THA and should be considered in light of THA failures due to component malposition.

Computed tomographic evaluation of femoral component rotation in total knee arthroplasty

BACKGROUND

Optimal femoral component rotational alignment in total knee arthroplasty (TKA) is crucial to establish a balanced knee reconstruction. Unbalanced knees can lead to instability, patellofemoral problems, persistent pain, stiffness, and generally poorer outcomes including early failure. Intraoperative techniques to achieve this optimal femoral component rotation include the use of the transepicondylar axis (TEA), the posterior-condylar-cut-parallel-to-the-tibial-cut (PCCPTC) technique and the anteroposterior axis technique (Whiteside's line). The purpose of this study was to compare the PCCPTC technique to the TEA technique using computed tomography (CT) scans to assess femoral component rotational alignment.

MATERIALS AND METHODS

This study used postoperative CT scans to compare the degree of femoral component rotation obtained with the use of PCCPTC technique and the TEA. The femoral component rotation of 30 TKA was measured on postoperative CT scans the angle of deviation between the two lines radiographic trans-epicondylar axis (rTEA) and femoral prosthesis posterior condylar line (FPPCL) was determined. This angle represented the rotation of the femoral component relative to the true rTEA.

RESULTS

The degree of rotation measured 2.67 ± 1.11 degrees in the PCCPTC group and 5.60 ± 1.64 degrees in the TEA group.

CONCLUSION

The use of the TEA technique for determining rotational alignment in TKR results in excessive external rotation of the femoral component compared to the PCCPTC technique.

The "Inside-Out" Technique for Correcting a Fixed Varus Deformity with Flexion Contracture in Total Knee Arthroplasty

Introduction

The inside-out technique is a safe and reproducible method to effectively correct a fixed varus-flexion deformity during total knee arthroplasty by performing a posteromedial capsular release and so-called pie-crust lengthening of the superficial medial collateral ligament (sMCL).

Step 1 Preoperative Planning

Analyze preoperative radiographs as a key step in planning the surgery for the required amount of osseous cuts and soft-tissue release.

Step 2 Exposure

Obtain adequate exposure for proper visualization and assessment.

Step 3 Tibial and Femoral Cuts

Adequate bone cuts with proper alignment are an essential step of this technique.

Step 4 Posteromedial Capsulotomy

This is the most important step for extension balancing in knees with flexion contracture; the posteromedial aspect of the capsule in varus deformity should be safely incised at the level of the tibial cut.

Step 5 Pie-Crusting of the sMCL

Perform pie-crusting followed by serial manipulations in a controlled manner to avoid overrelease of the sMCL.

Step 6 Flexion Gap Balancing

This is a key step for proper balancing, femoral sizing, rotation, lateralization, and patellofemoral tracking.

Results

From October 2006 to December 2009, thirty-one consecutive patients (thirty-four knees) with a severe fixed varus-flexion deformity (varus alignment of ≥15° and flexion contracture of ≥5°) underwent total knee arthroplasty with the inside-out technique.

What to Watch For

IndicationsContraindicationsPitfalls & Challenges.

The effect of patellar replacement technique on patellofemoral complications and anterior knee pain

Routine patella replacement with total knee arthroplasty has not been universally adopted because of associated patellofemoral complications such as anterior knee pain (AKP). In the proposed technique, the articular surface of the lateral facet of the patella is excised to the depth of the subchondral bone, and the medial facet is then cut parallel to the anterior surface. We evaluated any correlation between various radiographic parameters and AKP in 100 consecutive fixed-bearing posterior-stabilized total knee arthroplasties. There were no cases of fracture, avascular necrosis, subluxation, dislocation, patellar baja, or overstuffing of the patella. Anterior knee pain was present in 11% of cases, and no cases were severe or disabling. There were no correlations between AKP, range of motion, patellar size and shape, and any of the radiographic parameters.

Correcting fixed varus deformity with flexion contracture during total knee arthroplasty: the "inside-out" technique: AAOS exhibit selection

BACKGROUND

Traditional methods for correcting a severe varus and flexion deformity of the knee during total knee arthroplasty can often lead to excessive release of the medial collateral ligament, hematoma formation, and reliance on constrained implants. The "inside-out" technique for correction of varus deformities involves performing a posteromedial capsulotomy at the level of the tibial cut and incising the superficial medial collateral ligament in a pie-crust manner in extension followed by serial manipulations with valgus stress. Our hypothesis was that this technique effectively corrects severe knee varus and flexion deformity with a reduced risk of complications.

METHODS

Thirty-one consecutive patients (thirty-four knees) with a severe fixed varus and flexion deformity (varus alignment of ≥ 15° and flexion contracture of ≥ 5°) underwent total knee arthroplasty with use of the inside-out technique between October 2006 and December 2009. Physical examination, radiographs, and multiple outcome instruments were used to evaluate the results.

RESULTS

The mean duration of follow-up was 3.1 ± 1.1 years (range, 1.7 to 4.9 years). There were no cases of hematoma formation, excessive release of the medial collateral ligament, or acute or delayed instability. A semi-constrained TC3 implant was used in two cases. The mean preoperative coronal alignment was 21.1° ± 4° of varus, which was corrected to 4.5° ± 1.6° of valgus after surgery. The mean preoperative flexion contracture was 10° ± 3.5°. Postoperatively, two patients (three knees) had a residual flexion contracture, which was ≤5° in all cases. The mean range of knee motion improved from 103.3° ± 14.1° preoperatively to 119.1° ± 8° at the time of final follow-up. The mean Knee Society Score pain subscore improved from 39.5 ± 12.6 to 93.2 ± 10.5, and the function subscore improved from 47.1 ± 17.8 to 78.5 ± 21.9. There was no evidence of implant loosening or osteolysis on radiographs.

CONCLUSIONS

The technique described was safe, reproducible, and effective in treating combined varus and flexion deformity of the knee during total knee arthroplasty. It reduced the risks of over-release of the medial collateral ligament, hematoma formation, and the need for constrained implants.

Pain management after total knee arthroplasty using a multimodal approach

Improvements in pain management techniques over the past decade have had a significant impact on the outcomes of total knee arthroplasty. Of these techniques, multimodal approaches have shown potential. The purpose of this study was to compare the results of periarticular injection (PAI) to a combination of patient-controlled epidural analgesia and femoral nerve block (PCEA/FNB). Ninety patients undergoing primary unilateral total knee arthroplasty between June 2010 and March 2011 were randomized into 2 groups. The first group received the PCEA/FNB protocol, whereas the second group received the PAI. Mean patient age was 66.1 ± 8.7 years. All patients were operated on using a similar standard medial parapatellar approach, and all received preemptive analgesia and postoperative pain protocols. All patients were interviewed twice daily for the first 3 days postoperatively, once on day 7, and once in month 6. The 2 groups had similar readiness for discharge (PCEA/FNB group, 3.3 ± 1.2 days; PAI group, 3.2 ± 1.9 days). The results indicated no statistical difference between the 2 groups in 3 of 4 categories (rest in the morning, rest in the evening, and ambulation in the morning). Pain on ambulation was the only category that was statistically lower in the PCEA/FNB group than in the PAI group.Although the study demonstrates similar results between the 2 groups, PAI can play a major role in postoperative pain control in institutions that may not have appropriately trained individuals, equipment, and resources for PCEA/FNB. It also reduces many of the side effects and complications associated with regional anesthesia.

Properties of the patient administered questionnaires: new scales measuring physical and psychological symptoms of hip and knee disorders

The Patient Administered Questionnaires (PAQ) incorporate physical and psychological symptoms into one scale and permit more comprehensive self-reports for hip and knee disorders. We tested the psychometric properties of the PAQ-Hip and PAQ-Knee. Correlations between baseline PAQ-Hip and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were .39 to .72 (n = 102), .39 to .69 for score change (n = 68 post-total hip arthroplasty), and most κ values > .60 (n = 50). Correlations between baseline PAQ-Knee and WOMAC were .35 to .64 (n = 100), .62 to .79 for score change (n = 43 post-total knee arthroplasty), and most κ values >.60 (n = 51). For both scales, effect sizes were higher than for the WOMAC, and there was modest correlation between physical and psychological questions, indicating these concepts are not completely interchangeable. Thus, the PAQ scales have strong psychometric properties and are unique compared with existing scales by including physical and psychological symptoms.