Failure Following Revision Total Hip Arthroplasty after Cobalt-Chrome Femoral Heads are Placed on a Retained Femoral Stem.

BACKGROUND: Failure due to trunnionosis with adverse local tissue reaction (ALTR) has been reported with cobalt-chrome (CoCr) heads in total hip arthroplasty (THA); however, there is limited data on the use of these heads in the revision setting. The purpose of this study was to analyze the outcomes of patients who underwent revision THA with a retained femoral component and received a CoCr femoral head on a used trunnion. METHODS: In this retrospective review, we identified all patients who underwent revision THA with a retained femoral component and received a CoCr femoral head between February 2006 and March 2014. Demographic factors, implant details, and post-operative complications, including the need for repeat revisions, were recorded. In total, 107 patients were included (mean age 67 years, 74.0% women). Of the 107 patients, 24 (22.4%) required repeat revisions. RESULTS: Patients who required repeat revision were younger than those who did not (mean age: 62.9 versus 69, P = 0.03). The most common indications for repeat revision were instability (8 of 24, 33.3%), ALTR (5 of 24, 20.8%), and infection (4 of 18, 16.7%). Evidence of ALTR or metallosis was identified at the time of reoperation in 10 of the 24 patients who underwent re-revision (41.7%). CONCLUSION: The placement of a new CoCr femoral head on a used trunnion during revision THA with a retained femoral component carries a significant risk of complication (22.4%) and should be avoided when possible.

The Reverse Fragility Index: Interpreting the Current Literature on Long-Term Survivorship of Computer-Navigated Versus Conventional TKA: A Systematic Review and Cross-Sectional Study of Randomized Controlled Trials.

BACKGROUND: Despite the most recent American Academy of Orthopaedic Surgeons clinical practice guideline making a "strong" recommendation against the use of intraoperative navigation in total knee arthroplasty (TKA), its use is increasing. We utilized the concept of the reverse fragility index (RFI) to assess the strength of neutrality of the randomized controlled trials (RCTs) comparing the long-term survivorship of computer-navigated and conventional TKA. METHODS: A systematic review was performed including all RCTs through August 3, 2021, comparing the long-term outcomes of computer-navigated and conventional TKA. Randomized trials with mean follow-up of >8 years and survivorship with revision as the end point were included. The RFI quantifies the strength of a study's neutrality by calculating the minimum number of events necessary to flip the result from nonsignificant to significant. The RFI at a threshold of p < 0.05 was calculated for each study reporting nonsignificant results. The reverse fragility quotient (RFQ) was calculated by dividing the RFI by the study sample size. RESULTS: Ten clinical trials with 2,518 patients and 38 all-cause revisions were analyzed. All 10 studies reported nonsignificant results. The median RFI at the p < 0.05 threshold was 4, meaning that a median of 4 events would be needed to change the results from nonsignificant to significant. The median RFQ was 0.029, indicating that the nonsignificance of the results was contingent on only 2.9 events per 100 participants. The median loss to follow-up was 27 patients. In all studies, the number of patients lost to follow-up was greater than the RFI. CONCLUSIONS: The equipoise in long-term survivorship between computer-navigated and conventional TKA rests on fragile studies, as their statistical nonsignificance could be reversed by changing the outcome status of only a handful of patients--a number that was always smaller than the number lost to follow-up. Routine reporting of the RFI in trials with nonsignificant findings may provide readers with a measure of confidence in the neutrality of the results. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Continuous Femoral Nerve Block Reduces the Need for Manipulation Following Total Knee Arthroplasty.

Peripheral nerve blocks improve both pain control and functional outcomes following total knee arthroplasty (TKA). However, few studies have examined the effects of different peripheral nerve block protocols on postoperative range of motion. The present study assessed the impact of a single-shot femoral nerve block (SFNB) versus continuous femoral nerve block (CFNB) on postoperative range of motion and the need for subsequent manipulation following TKA. Methods: We retrospective reviewed patient charts to identify patients who had undergone primary elective unilateral TKA by 2 surgeons at a high-volume orthopaedic specialty hospital over a 3-year period. A total of 1,091 patients received either SFNB or CFNB and were included in the data analysis. Identical surgical techniques, postoperative oral analgesic regimens, and rehabilitation protocols were used for all patients. Patients with <90° of flexion at 6 weeks postoperatively underwent closed manipulation under anesthesia (MUA). Results: Overall, 608 patients (55.7%) received CFNB and 483 patients (44.3%) received SFNB. Overall, 94 patients (8.6%) required postoperative manipulation for stiffness, including 36 (5.9%) in the CFNB group and 58 (12%) in the SFNB group. The 50% reduction in the need for manipulation in the CFNB group was independent of primary surgeon (p > 0.05). No significant differences were observed between the groups in terms of postoperative range of motion, either at the time of discharge or at 6 weeks postoperatively. A history of knee surgery, decreased preoperative range of motion, and decreased range of motion at the time of discharge were significantly associated with the need for further MUA (p = 0.0002, p < 0.0001, and p < 0.0001, respectively). Conclusions: Despite similar final postoperative range of motion between patients in both groups, our results suggest that CFNB may be superior to SFNB for reducing the need for postoperative manipulation after primary TKA. Furthermore, a history of ipsilateral knee surgery, decreased preoperative range of motion, and decreased range of motion at the time of discharge were identified as independent risk factors for postoperative stiffness requiring MUA after primary TKA. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Reducing Narcotic Usage With 0.5% Bupivacaine Periarticular Injections in Total Knee Arthroplasty.

BACKGROUND: Periarticular injections (PAIs) and adductor canal blocks (ACBs) are widely accepted pain management strategies for total knee arthroplasty (TKA); however, the optimal anesthetic concentration to provide adequate pain relief while avoiding toxicity remains controversial. The purpose of this study is to evaluate the efficacy of different anesthetic concentrations for PAI alone and in combination with ACB. METHODS: This retrospective cohort study of patients undergoing primary TKAs between January 2019 and November 2020 included 3 groups: 0.25% PAI (50 cc of 0.25% bupivacaine PAI diluted with 50 cc of saline and ketorolac), 0.5% PAI (50 cc of 0.5% bupivacaine with 50 cc of saline and ketorolac), and PAI + ACB (ultrasound-guided preoperative anesthesiologist-administered ACB and 0.25% PAI). RESULTS: In total, 368 TKAs were analyzed (123 0.25%, 132 0.5%, and 113 PAI + ACB). Total overall hospital narcotic usage in oral morphine equivalents (OME) was significantly lower for the 0.5% group (120.09 vs 165.26 and 175.75) compared to the 0.25% and PAI + ACB groups, respectively (P < .0001). Cumulative OME for the first 3 shifts was also lower for 0.5% (68.7 vs 83.7 and 76.4) compared to the 0.25% and PAI + ACB groups, respectively (P = .030). Total postoperative narcotics in OME were significantly lower for 0.5% (617.9 vs 825.2 and 1047.6) than 0.25% and PAI + ACB, respectively (P = .0003). Number of prescriptions within 6 weeks postoperatively were also significantly lower for 0.5% (1.7) than 0.25% (2.1) and PAI + ACB (2.4) (P = .0003). CONCLUSION: Patients receiving 0.5% PAI had lower narcotic usage compared to 0.25% PAI or PAI + ACB. ACB may be eliminated without compromising pain control if the dose of local anesthetic in the PAI is sufficiently high.

Range of Motion at Discharge Predicts Need for Manipulation following Total Knee Arthroplasty.

Stiffness following total knee arthroplasty (TKA) is a common complication that can result in unsatisfactory outcomes. Manipulation under anesthesia (MUA) has been widely employed to treat this problem. It is uncertain whether an association exists between range of motion (ROM) at discharge and need for MUA following primary TKA.A retrospective review of an institutional joint registry identified cases of primary TKA performed by three surgeons at a single institution over a 22-month period. A logistic regression model was used to examine the association between ROM at discharge and subsequent MUA controlling for confounding variables related to patient demographics and perioperative details. Of the 1,546 cases identified, 113 (7.3%) cases underwent subsequent MUA. As discharge ROM increased, manipulation rates decreased. Patients with discharge flexion <65 degrees were more likely to undergo MUA than those with flexion >90 degrees (odds ratio [OR] = 17.57, 95% confidence interval [CI] [7.97, 38.73], p < 0.0001). The largest differential in odds of MUA was observed between the <65 degrees at discharge group (OR = 17.57) and the 65 ≤ 75 degrees at discharge group (OR = 7.89). At discharge ROM of 80 ≤ 90 degrees of flexion, patients had more than a twofold increase in odds of MUA relative to those in the >90 degrees group (OR = 2.22, 95% CI [1.20, 4.10], p = 0.011). The results of this study suggest that there is an association between lower ROM at discharge and greater risk of MUA post primary TKA. Counseling patients in regard to discharge ROM and associated risk of MUA may optimize gains in ROM during recovery.

Anthropometric Measures of the Posterior Condyles: Gender Differences and Correlation to Implant Sizing.

There is abundant data concerning morphological dimensions of the distal femur, particularly in women, which has led to redesign of the femoral component in total knee arthroplasty (TKA). Clinical experience reveals existing asymmetry of the femoral posterior condyles, yet current implant designs have a symmetrical femoral component. The objectives of this study were to analyze the dimensions of posterior condylar bone resection from a group of patients undergoing TKA and correlate the measurements to one prosthetic system. We retrospectively reviewed single surgeon morphological data from the posterior condyles of 105 knees during TKA. The study included 54 males and 51 females. Measurement of the posterior condylar bones was performed with a standard metric metal ruler by one investigator. Known dimensions of a single type of implant design were compared with the resection data. The average difference of posterior medial and lateral condylar width was 5.7 and 5.3 mm in males and females, respectively. The average host posterolateral condylar bone was 5.4 mm less than the trial implant across five sizes in both males and females. Results suggest that the dimension of the posterior lateral condyle is much smaller than the dimension of the implant in both groups of patients. Dimension of the posterior medial is close to dimension of the implant. Overhang of the component posterolaterally can create soft tissue irritation and result in postoperative pain and decreased range of motion. Our results increase awareness of the dimensions of the native posterolateral condyle and may influence future design of femoral implants used in total knee arthroplasty.

Intraoperative Proximal Tibia Periprosthetic Fractures in Primary Total Knee Arthroplasty.

Intraoperative fracture of the proximal tibia is a rare complication of total knee arthroplasty (TKA) with few studies available reporting risk factors or prognosis. A review of our prospective joint registry was performed to determine the incidence and associated risk factors of intraoperative tibia fractures during primary TKA; 14,966 TKAs of all manufacturers were performed with 9 intraoperative tibia fractures. All fractures occurred in a single TKA design. There were 8,155 TKAs of this design performed with a fracture incidence of 0.110%. All but one fracture occurred on the medial tibial plateau, and all but one occurred during preparation of the tibia with keel punching. A control group of 75 patients (80 knees) with the same TKA design were randomly selected. Baseplates size 3 or smaller were less likely to experience an intraoperative fracture (odds ratio [OR]: 0.864, 95% confidence interval [CI]: 0.785-0.951), as were knees with a polyethylene insert thickness of 13 mm or larger (OR: 0.882, 95% CI: 0.812-0.957). Fractures were treated with a variety of different methods, but every patient had at least one screw placed and most (67%) had postoperative weight-bearing restrictions. At final follow-up, there were no cases of nonunion, component subsidence, or need for reoperation. Intraoperative tibia fractures are a rare complication of this TKA design at 0.11%. Knees with baseplates of size ≤3 and polyethylene thickness ≥13 mm were less likely to experience intraoperative fracture. These findings may be related to the depth of tibial resection, requiring the use of a thicker polyethylene insert, and a change in the keel width in implants size 4 or larger. No fracture patients required reoperation.

Decreasing Incidence of Postoperative Ileus following Total Knee Arthroplasty: A 17-Year Retrospective Review of 38,007 Knee Replacements at One Institution.

Ileus following total knee arthroplasty is a clinically and financially significant postoperative complication that has not been extensively described in the orthopaedic joint literature. Ileus has been found to occur in 0.7 to 4.0% of patients after total joint arthroplasty. In a 17-year period (2001 fiscal year through 2017 fiscal year) at one institution, we found an incidence of 0.500% (190/38,007) following knee arthroplasty. In addition, the incidence of ileus following total knee arthroplasty (TKA) has drastically declined over this 17-year period, from 1.593% (13/816) in 2001 to 0.120% (4/3,332) in 2017. This decrease may be attributed to a reduction in narcotic use postoperatively, earlier ambulation following surgery, and reduction in length of hospital stay. Though postoperative ileus is not yet a preventable complication, recognition of risk factors may permit earlier intervention to ameliorate some of the morbidity associated with this condition.

Factors Influencing Survivorship in Vasculopathic Patients.

Total knee arthroplasty (TKA) in patients with peripheral vascular disease has sparsely been studied. This study examined patient and radiographic factors that could affect reoperation free survival in these patients. We retrospectively reviewed TKA procedures performed in patients with nonpalpable pulses on physical examination between January 1, 2004, and December 31, 2013. Ninety-two cases met inclusion criteria. Preoperative ankle-brachial index (ABI), date of surgery, sex, age, body mass index (BMI), tourniquet use, American Society of Anesthesiologists (ASA) score, presence of preoperative calcifications, and follow-up data were obtained. Failure was defined as reoperation. Patients were included if they experienced a failure or had at least 2 years of follow-up. Reoperation free survival was calculated by Kaplan-Meier's analysis. Odds ratios (ORs) were calculated for patient factors; hazard ratios (HRs) were calculated by Cox's regression analysis. Ninety-two TKAs were included in the study. Mean age was 68.8 years, mean BMI was 32.15, and mean ASA score was 2.44. Tourniquet was used in 78 patients. Mean preoperative ABI was 1.016. Nine patients had calcifications on X-ray prior to surgery. Reoperation free survival was 9.378 years. Patients with a preoperative ABI of below 0.7 had shorter reoperation free survival (ABI <0.7, 6.854 years; ABI >0.7, 9.535 years; p = 0.015). Patients with a preoperative ABI below 0.7 had greater odds of failure and were at higher risk for earlier failure (OR = 6.5, p = 0.027; HR = 1.678, p = 0.045). When corrected for age, sex, and BMI, the HR for patients with a preoperative ABI below 0.7 worsened (HR = 1.913, p = 0.035) compared with those with an ABI above 0.7. The remaining patient factors produced no statistically significant differences in survivorship, odds of failure, or HRs. No patient factors were associated with increased risk of mortality. These results suggest that patients who undergo TKA with an ABI below 0.7 are at increased risk for reoperation and have shorter reoperation free survival.

Total Knee Arthroplasty in Patients of Advanced Age: A Look at Outcomes and Complications.

Total knee arthroplasty (TKA) is one of the most highly successful orthopaedic procedures performed in North America. It is also one of the most common procedures performed, and its incidence continues to increase. Despite this, it is the opinion of many that patients of advanced age groups are not ideal candidates to undergo such procedures secondary to the concern over higher complication rates and poorer functional outcomes. This review article attempts to analyze the current body of literature concerning TKA outcomes and to evaluate some of the issues that are more specific to this population when they undergo TKA. It is our hypothesis that the literature does not support this popular misconception, and that older patients who do not have significant medical comorbidities are good candidates to undergo primary TKA. However, certain cohorts of this population are not ideal candidates to undergo this procedure. Also, certain joint reconstructive procedures, such as simultaneous and staged bilateral TKA, are higher risk procedures in this patient cohort.

Femoral Intramedullary Alignment in Total Knee Arthroplasty: Indications, Results, Pitfalls, Alternatives, and Controversies.

While femoral intramedullary alignment has been found to be the most accurate and reproducible method for proper femoral component orientation in total knee arthroplasty, certain situations preclude the use of intramedullary alignment, such as ipsilateral long-stem total hip arthroplasty, femoral shaft deformity (congenital or post-traumatic), capacious femoral canal, and retained hardware. These cases require alternative alignment guides, that is, extramedullary alignment. The purpose of this study was to determine the accuracy of intramedullary alignment in reproducing the femoral anatomic axis. Using 35 adult cadaveric femora without obvious clinical deformity, and 7 with proximal prosthetic devices blocking the passage of an intramedullary guide, the accuracy of the guide rod was assessed both anatomically and radiographically. In the seven femora with proximal femoral devices, the guide rod could not be completely seated, resulting in a greater degree of flexion of the guide rod compared with the mechanical axis of the femur, and a greater degree of varus compared with the anatomical axis, as compared with 35 femora without obvious deformity. In cases where seating of the intramedullary guide rod is either incomplete or impossible, extramedullary femoral guides allow more accurate determination of the distal femoral cut by referencing directly from the mechanical axis, that is, the center of the femoral head. We present case studies as examples of indications for use of an extramedullary femoral guide. In addition, we demonstrate two different techniques for extramedullary femoral alignment using fluoroscopic guidance in cases incompatible with intramedullary alignment.

Revision of a dual-modular stem in patients with adverse tissue reaction.

BACKGROUND: Dual-modular femoral components with exchangeable cobalt-chrome neck segments have had higher than expected failure rates due to corrosion and adverse local tissue reaction (ALTR). Complications, survival rates and early clinical outcomes of revision surgery for the treatment of corrosion and ALTR as a result of these implants are underreported. METHODS: We identified 44 cases of revision THA for corrosion and ALTR resulting from the same dual modular stem. All revision procedures were performed using a modular tapered fluted titanium stem, ceramic heads and highly cross-linked polyethylene. RESULTS: Complications included: dislocation, infection, reoperation, and chronic pain. Mean Harris Hip Score was 84 following revision surgery. CONCLUSIONS: Patients undergoing revision surgery for ALTR related to this prosthesis should be aware of the risk of postoperative dislocation and other complications and the potential long-term risk of some chronic pain.

Midterm follow-up of total hip arthroplasty in a patient with contralateral Van Nes rotationplasty for congenital proximal femoral focal deficiency.

Total hip arthroplasty is a durable and effective operation in those with normal gait patterns. However, to our knowledge, there is no current literature on longevity in patients who have had a contralateral Van Nes rotationplasty for proximal femoral focal deficiency. We found evidence that patients who underwent rotationplasty have increased demands on the contralateral extremity and higher percentage of their gait cycle on the unaffected extremity. Here, we present a unique case report of a 59-year-old male patient with a 6-year follow-up status after left total hip arthroplasty and a right-sided rotationplasty performed during adolescence. Upon chart and radiograph review, we found no early signs of wear of his hip arthroplasty and a fully functioning lower extremity. In our limited experience, we found that total hip arthroplasty was a safe and durable operation for our patient who underwent a contralateral Van Nes rotationplasty at the 6-year follow-up period.

Efficacy of manipulation under anesthesia beyond three months following total knee arthroplasty.

BACKGROUND: Stiffness after total knee arthroplasty (TKA) is often treated with manipulation under anesthesia (MUA) to improve range of motion (ROM). However, many authors recommend against MUA beyond 3 months after TKA. This study investigates the timing of MUA for stiffness after TKA, focusing on MUA performed at >12 weeks. METHODS: In total, 142 MUAs were retrospectively reviewed. "Early" MUAs were at <12 weeks after TKA; "Late" MUAs were >12 weeks. MUAs were further subdivided into 4 groups: 83 "Group I" cases at <12 weeks, 34 "Group II" between 12 and 26 weeks, 12 "Group III" between 26 and 52 weeks, and 13 "Group IV" at >52 weeks. Gains in ROM were compared between groups. RESULTS: Gains in flexion and overall ROM were statistically equivalent in Early vs Late MUA when controlling for pre-MUA ROM. ROM gains between the early Group I and the later Groups II-IV were also statistically comparable. Overall ROM gain in Group I was 24.1°, 17.9° in Group II, 20.8° in Group III, and 11.1° in Group IV. There were no significant complications. CONCLUSIONS: Early and late MUA resulted in statistically equivalent gains in ROM, regardless of timing after TKA. All groups showed an average improvement in ROM of ≥11°. MUA performed beyond 3 months, and even beyond 1 year, appears to be safe and may improve ROM and allow select patients to avoid revision surgery.

An Update to a Novel Technique for Centering the Femoral Stem in Primary Total Hip Arthroplasty.

Careful surgical technique is a critical component of total hip arthroplasty. Femoral preparation and component positioning are vital to improving outcomes and preventing complications. Femoral preparation begins with creating an entry hole in the proximal femur. Various tools have been used for this purpose which resemble a "cookie cutter." An axial starter reamer, or awl, is then inserted through the entry hole in the proximal femur to aid in opening and centralizing the canal for sequential reaming or broaching. A novel technique was described previously which allows the awl to center itself in the canal with little risk of deviation from midline or cortical perforation. Since describing this technique in 2014, the senior surgeon has further modified the method of preparing the entry hole in the proximal femur. The surgeon now uses a 1/8" drill bit to penetrate the piriformis fossa, instead of a "cookie cutter" or osteotome. A 1/8" entry hole eliminates gaps between the bone and the implant, results in lateralization of the stem, and avoids varus malposition. We evaluated 300 primary hip arthroplasties by a single surgeon using one of the three techniques: traditional clockwise technique (Group 1), our previously published novel counterclockwise technique (Group 2), and our updated novel technique (Group 3). While the deviation from midline of Group 3 did not differ significantly from Group 2, it was significantly less than the deviation from midline of Group 1 (p=00006). This simple updated technique enables the surgeon to avoid potential malalignment during femoral preparation.

Comparison of the history and physical examination for hip osteoarthritis and lumbar spinal stenosis.

BACKGROUND: Leg pain associated with walking is sometimes incorrectly attributed to hip osteoarthritis (OA) or lumbar spinal stenosis (LSS). PURPOSE: This study compared physicians' values of signs and symptoms for diagnosing and differentiating hip OA and LSS to their clinical utility. STUDY DESIGN/SETTING: Musculoskeletal physicians were surveyed with online questionnaires. Patients were recruited from hip and spine specialty practices. PATIENT SAMPLE: Seventy-seven hip OA and 79 LSS patients. OUTCOME MEASURES: Signs and symptoms of hip OA and LSS. METHODS: Fifty-one of 66 invited musculoskeletal physicians completed online surveys about the values of 83 signs and symptoms for diagnosing hip OA and LSS. Of these, the most valued 32 symptoms and 13 physical examination items were applied to patients with symptomatic hip OA or LSS. Positive likelihood ratios (+LR) were calculated for each items' ability to differentiate hip OA from LSS, with a +LR>2 set as indicating usefulness for favoring either diagnosis. Positive LRs were compared with surveyed physicians' values for each test. RESULTS: All symptoms were reported by some patients with each diagnosis. Only 11 of 32 physician-valued symptoms were useful for discriminating hip OA from LSS. Eight symptoms favored hip OA over LSS: groin pain (+LR=4.9); knee pain (+LR=2.2); pain that decreased with continued walking (+LR=3.9); pain that occurs immediately with walking (+LR=2.4); pain that occurs immediately with standing (+LR=2.1); pain getting in/out of a car (+LR=3.3); pain with dressing the symptomatic leg (+LR=3.1); and difficulty reaching the foot of the symptomatic leg while dressing (+LR=2.3). Three symptoms favored LSS over hip OA: pain below the knee (+LR=2.3); leg tingling and/or numbness (+LR=2.7); and some pain in both legs (+LR=2.5). Notable symptoms that did not discriminate hip OA from LSS included: pain is less while pushing a shopping cart (+LR=1.0); back pain (+LR=1.1); weakness and/or heaviness of leg (+LR=1.1); buttocks pain (+LR=1.2); poor balance or unsteadiness (+LR=1.2); pain that increased with weight-bearing on the painful leg (+LR=1.3), and step to gait on stairs (+LR=1.7). Consistent with physicians' expectations, 7 of 13 physical examination items strongly favored hip OA over LSS: limited weight-bearing on painful leg when standing (+LR=10); observed limp (+LR=9); and painful and restricted range-of-motion with any of five hip maneuvers (+LR range 21-99). Four of five tested neurological deficits (+LR range 3-8) favored the diagnosis of LSS over hip OA. CONCLUSIONS: There is substantial crossover of symptoms between hip OA and LSS, with some physician-valued symptoms useful for differentiating these disorders whereas others were not. Physicians recognize the value of the examination of gait, the hip, and lower extremity neurological function for differentiating hip OA from LSS. These tests should be routinely performed on all patients for which either diagnosis is considered. Awareness of these findings might reduce diagnostic errors.

An Algorithm for Detection and Correction of Pelvic Tilt in Total Hip Replacement.

Successful joint replacement surgery requires precise preoperative planning and intraoperative placement of implants such that the function of the joint is optimized biomechanically and biologically. The five-step "pelvic tilt algorithm" will enhance the outcome of hip replacement surgery as a result of improved acetabular component alignment. It will solve the problem of pelvic tilt as an unknown variable during hip replacement surgery, and will allow for more consistent and accurate acetabular component placement.

Incidence and Risk Factors for Posterior Cruciate Ligament Avulsion during Cruciate Retaining Total Knee Arthroplasty.

During cruciate retaining (CR) total knee arthroplasty (TKA), the posterior cruciate ligament (PCL) may avulse at its insertion. The incidence of PCL avulsion fracture has not been previously studied. The aim of this study is to report on the incidence and clinical significance of intraoperative PCL avulsion during primary CR TKA and to identify potential risk factors. Our institutional joint registry was retrospectively reviewed for PCL avulsion occurring during CR TKA implanted between April 2008 and April 2016. Patient demographics, preoperative range of motion (ROM), complications, and revision rate were examined. A control group of 132 patients was used for comparison to identify potential risk factors. Forty-four of 2,457 patients (1.7%) suffered a PCL avulsion fracture during primary CR TKA. No intraoperative repair was performed and no postoperative weight bearing or ROM restrictions were implemented. There was no significant difference in BMI (p = 0.258), mean preoperative ROM (p = 0.763), or femoral and tibial component sizes (p = 0.3069, p = 0.1306) between groups. Logistic regression found female gender (p = 0.0254) to be the only statistically significant risk factor for PCL avulsion. The incidence of intraoperative PCL avulsion fracture during CR TKA is low (1.7%) and does not appear to affect postoperative ROM, subjective stability, or incidence of revision. Female gender was identified as the only patient factor that increased the risk of PCL avulsion fracture.

Effects of Coronal Limb Alignment and Ligament Balance on Pain and Satisfaction Following Total Knee Arthroplasty at Short-Term Follow Up.

INTRODUCTION: Few studies have evaluated the concomitant effect of both total knee arthroplasty (TKA) limb alignment and ligament laxity. Therefore, the primary aim of this study is to evaluate the impact of lower extremity alignment on the short-term outcome (one year) following TKA, including pain relief, function, and patient satisfaction. The secondary aim of the study is to evaluate the impact of ligament laxity and balance on early outcomes following TKA. MATERIALS AND METHODS: A prospective evaluation of mechanical alignment and ligament tension was performed for 110 consecutive TKAs using an identical surgical technique. Patients were evaluated with knee society score, visual analog pain score, and satisfaction one year following TKA. Linear regression analysis was then performed to determine the effect of lower extremity alignment and ligament laxity. RESULTS: There was no significant relationship between lower extremity alignment and outcome measures. A significant relationship was identified between medial collateral laxity in full extension and knee society scores for function, but not for pain. There was also a significant relationship identified between lateral knee laxity at 90 degrees of flexion and knee society score and pain at one-year follow up. CONCLUSION: Our results demonstrated no correlation between mechanical alignment restoration and pain or function. However, more interestingly, this study found patients with medial laxity in extension and lateral laxity in knee flexion, similar to normal physiologic knee laxity, to have less pain and greater function and satisfaction at one-year short-term follow up.

Influence of Soft Tissue Preservation in Total Hip Arthroplasty: A 16-Year Experience.

BACKGROUND: Surgical technique in total hip arthroplasty (THA) has been a topic of debate over the last 50 years. Evidence-based studies are needed to compare one technique to another. This study investigated the outcome of the direct superior approach in primary THA as measured by patient perception of pain and recovery over a 16-year period. MATERIALS AND METHODS: We retrospectively reviewed a series of 3,357 consecutive patients who underwent primary THA by a single surgeon using the direct superior approach between 2001 and 2017. The surgical technique was modified twice during this 16-year period. The first modification (2007) consisted of piriformis tendon preservation. The second modification (2012) consisted of iliotibial band (ITB) preservation. These two modifications of the surgical technique created three different patient groups. A telephone interview regarding patient pain and recovery after each THA was conducted with 147 patients who had staged bilateral THA procedures wherein the surgical technique was modified between the first and second (contralateral) THA. RESULTS: Results show the addition of ITB preservation to capsular repair, with or without piriformis preservation, greatly improves the patient's perception of pain and recovery, causing the majority of patients to prefer their ITB-preserving surgery over their ITB-sacrificing surgery. In addition, the dislocation rate over this 16-year period is 0.17%. CONCLUSION: The direct superior approach to the hip results in excellent stability with a dislocation rate of 0.17%. The patient's perception of pain and recovery is dramatically improved with preservation of the iliotibial band.