Christopher, Zachary K.

Introduction Krackow Type II valgus deformity is defined by attenuation of the medial collateral ligament (MCL). However, little quantitative information exists about associated intra-operative MCL laxity. Furthermore, a corollary may exist in varus deformity with associated lateral ligament laxity but is poorly described. Robotic-assisted total knee arthroplasty (raTKA) includes quantitative assessment of intraoperative ligament function. This study evaluated whether increased preoperative medial or lateral radiographic joint space width (JSW) in valgus or varus knees, was associated with increased intraoperative soft tissue laxity of the respective compartment. Methodology Intraoperative data from 348 consecutive raTKAs with 270 varus knees (hip-knee-ankle angle [HKA]<-2°), and 78 valgus knees, (HKA>2°) were retrospectively reviewed. For varus knees, lateral JSW was measured on preoperative, standing anteroposterior radiographs to determine lateral widening (threshold 8.0mm). For valgus knees, medial JSW was evaluated to determine medial widening (threshold 7.0mm). Intraoperative medial and lateral gaps at 0° and 90° had been recorded during manual stress testing. Linear regression was performed to determine associations between intra-operative gaps, radiographic JSW, and HKA. Results 51 varus knees demonstrated lateral widening and 15 valgus knees had medial widening. In varus knees, lateral JSW was positively associated with the lateral extension (β=0.76, P <0.001) and flexion (β=0.74, P <0.001) gaps. Similarly, for valgus knees, medial JSW was positively associated with the medial extension (β=0.75, P <0.001) and flexion (β=0.77, P <0.001) gaps. Conclusion Increased preoperative radiographic JSW of the medial and lateral compartment in valgus and varus knees, predicted increased intraoperative gaps of that compartment, consistent with ligament attenuation.

Background: There has been minimal literature evaluating how a prior myocardial infraction (MI) influences outcomes after total knee arthroplasty (TKA). Thus, the purpose of this study was to evaluate how the timing, type, and treatment of MI prior to TKA affect postoperative cardiac complications, general medical complications, and surgical complications. Methods: A retrospective comparative study was conducted using a large insurance database. Patients undergoing primary TKA for osteoarthritis were included. Patients who had experienced MI within 2 years before TKA were identified and were matched 1:4 with patients who had not had such an MI on the basis of demographic variables and comorbidities. Patients who had a prior MI were stratified into 4 groups based on the timing of the MI: 0 to <6 months, 6 to <12 months, 12 to <18 months, and 18 to 24 months before TKA. The rates of postoperative cardiac, general medical, and surgical complications were compared between groups. Subanalyses on the prior MI type, treatment, and location were performed. Results: Prior MI was associated with increased risks of postoperative MI (odds ratio [OR], 3.97 [95% confidence interval (CI), 3.20 to 4.93]), heart failure (OR, 1.45 [95% CI, 1.24 to 1.75]), and 90-day mortality (OR, 2.15 [95% CI, 1.41 to 3.28]). The risk of postoperative MI was highest for those with MI within 6 months before TKA (OR, 6.86 [95% CI, 5.34 to 8.82]). Type-1 MI, ST-elevation MI (STEMI), non-ST-elevation MI (NSTEMI), and anterior and inferior MIs were linked to elevated postoperative MI and/or mortality risks, with timing closer to surgery further amplifying the risk. Percutaneous coronary intervention within 6 months before TKA also increased postoperative risks. Type-2 MI within 6 months before TKA was associated with an increased risk of periprosthetic joint infection compared with controls (OR, 4.23 [95% CI, 1.67 to 10.67]). Conclusions: Patients who had a prior MI, particularly within 6 months before TKA, had significantly elevated risks of postoperative MI, heart failure, and mortality. Outcomes varied by MI type, treatment, and location, with type-1 MIs and STEMIs increasing the postoperative mortality risk. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background: Although it is well established that the type of organism can be a risk factor for failure in patients with periprosthetic joint infection (PJI), no study to date has examined the impact of the number of positive cultures on treatment outcomes in patients undergoing 2-stage exchange. The purpose of this multicenter study was to determine the prognostic utility of multiple positive cultures at resection as a predictor of failure following reimplantation. Methods: This retrospective multicenter study identified 437 patients with chronic knee PJI who had undergone 2-stage exchange arthroplasty with a minimum of 1 year of follow-up following reimplantation. PJI was defined with use of the 2013 Musculoskeletal Infection Society (MSIS) criteria. Patients with culture-negative PJI were excluded (n = 138). Treatment failure was defined as either any reoperation for infection or PJI-related mortality. Multivariable regression controlling for risk factors for failure after a 2-stage arthroplasty was performed to determine whether ≥2 positive intraoperative cultures at resection can predict outcomes following reimplantation when compared with a single positive culture. Results: Two hundred and ninety-nine patients were included. At a mean follow-up of 6.2 ± 2.6 years, 48 patients (16.1%) experienced failure. Patients who had a failure were more likely to have had a longer interstage interval (p = 0.038) and were also more likely to have had ≥2 positive cultures at the time of resection arthroplasty (95.8% versus 75.3%; p = 0.001). On regression analysis, ≥2 positive cultures at resection was the only variable that was identified as a risk factor for failure following reimplantation in both the univariate (odds ratio [OR], 7.55 [95% CI, 2.24 to 47.0]; p = 0.006) and multivariable models (OR, 8.12 [95% CI, 2.31 to 51.9]; p = 0.005). Conclusions: This is the first study to examine the impact of the number of positive cultures on outcomes in patients with PJI. We found that the presence of ≥2 positive cultures at resection was an indicator of a poor prognosis and resulted in a greater than eightfold increase in the risk of treatment failure in patients undergoing a 2-stage exchange. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Purpose To evaluate the rates of lateral femoral cutaneous nerve (LFCN) injury in patients who underwent a direct anterior approach (DAA) total hip arthroplasty (THA) with and without previous hip arthroscopy. Methods We retrospectively investigated consecutive DAA THAs performed by a single surgeon. These cases were grouped into patients with and without a history of previous ipsilateral hip arthroscopy. LFCN sensation was assessed during the initial follow‐up (6 weeks) and 1‐year (or most recent) follow‐up visits. The incidence and character of LFCN injury was compared between the 2 groups. Results In total, 166 patients underwent a DAA THA with no previous hip arthroscopy, and 13 had a history of previous arthroscopy. Of the 179 total patients who underwent THA, 77 experienced some form of LFCN injury at initial follow‐up (43%). The rate of injury for the cohort with no previous arthroscopy was 39% (n = 65/166) on initial follow‐up, whereas the rate of injury for the cohort with a history of previous ipsilateral arthroscopy was 92% (n =12/13) on initial follow‐up ( P < .001). In addition, although the difference was not significant, 28% (n = 46/166) of the group without history of previous arthroscopy and 69% (n = 9/13) of the group with a history of previous arthroscopy had continued symptoms of LFCN injury at most recent follow‐up. Conclusions In this study, patients who underwent hip arthroscopy before an ipsilateral DAA THA were at increased risk of LFCN injury compared with patients who underwent a DAA THA without a previous hip arthroscopy. At final follow‐up of patients with initial LFCN injury, symptoms resolved in 29% (n = 19/65) of patients with no previous hip arthroscopy and 25% (n = 3/12) of patients with previous hip arthroscopy. Level of Evidence Level III, case–control study.

Abstract Background The minimum clinically important difference (MCID) is intended to detect a change in a patient-reported outcome measure (PROM) large enough for a patient to appreciate. Their growing use in orthopaedic research stems from the necessity to identify a metric, other than the p value, to better assess the effect size of an outcome. Yet, given that MCIDs are population-specific and that there are multiple calculation methods, there is concern about inconsistencies. Given the increasing use of MCIDs in total hip arthroplasty (THA) research, a systematic review of calculated MCID values and their respective ranges, as well as an assessment of their applications, is important to guide and encourage their use as a critical measure of effect size in THA outcomes research. Questions/purposes We systematically reviewed MCID calculations and reporting in current THA research to answer the following: (1) What are the most-reported PROM MCIDs in THA, and what is their range of values? (2) What proportion of studies report anchor-based versus distribution-based MCID values? (3) What are the most common methods by which anchor-based MCID values are derived? (4) What are the most common derivation methods for distribution-based MCID values? (5) How do the reported medians and corresponding ranges compare between calculation methods for each PROM? Methods The EMBASE, MEDLINE, and PubMed databases were systematically reviewed from inception through March 2022 for THA studies reporting an MCID value for any PROMs. Two independent authors reviewed articles for inclusion. All articles calculating new PROM MCID scores after primary THA were included for data extraction and analysis. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each article. In total, 30 articles were included. There were 45 unique PROMs for which 242 MCIDs were reported. These studies had a total of 1,000,874 patients with a median age of 64 years and median BMI of 28.7 kg/m 2 . Women made up 55% of patients in the total study population, and the median follow-up period was 12 months (range 0 to 77 months). The overall risk of bias was assessed as moderate using the modified Methodological Index for Nonrandomized Studies criteria for comparative studies (the mean score for comparative papers in this review was 18 of 24, with higher scores representing better study quality) and noncomparative studies (for these, the mean score was 10 of a possible 16 points, with higher scores representing higher study quality). Calculated values were classified as anchor-based, distribution-based, or not reported. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each study. Anchor-based and distribution-based MCIDs were compared for each unique PROM using a Wilcoxon rank sum test, given the non-normal distribution of values. Results The Oxford Hip Score (OHS) and the Hip Injury and Osteoarthritis Score (HOOS) Pain and Quality of Life subscore MCIDs were the most frequently reported, comprising 12% (29 of 242), 8% (20 of 242), and 8% (20 of 242), respectively. The EuroQol VAS (EQ-VAS) was the next-most frequently reported (7% [17 of 242]) followed by the EuroQol 5D (EQ-5D) (7% [16 of 242]). The median anchor-based value for the OHS was 9 (IQR 8 to 11), while the median distribution-based value was 6 (IQR 5 to 6). The median anchor-based MCID values for HOOS Pain and Quality of Life were 33 (IQR 28 to 35) and 25 (14 to 27), respectively; the median distribution-based values were 10 (IQR 9 to 10) and 13 (IQR 10 to 14), respectively. Thirty percent (nine of 30) of studies used an anchor-based method to calculate a new MCID, while 40% (12 of 30) used a distribution-based technique. Thirty percent of studies (nine of 30) calculated MCID values using both methods. For studies reporting an anchor-based calculation method, a question assessing pain relief, satisfaction, or quality of life on a five-point Likert scale was the most commonly used anchor (30% [eight of 27]), followed by a receiver operating characteristic curve estimation (22% [six of 27]). For studies using distribution-based calculations, the most common method was one-half the standard deviation of the difference between preoperative and postoperative PROM scores (46% [12 of 26]). Most reported median MCID values (nine of 14) did not differ by calculation method for each unique PROM (p > 0.05). The OHS, HOOS JR, and HOOS Function, Symptoms, and Activities of Daily Living subscores all varied by calculation method, because each anchor-based value was larger than its respective distribution-based value. Conclusion We found that MCIDs do not vary very much by calculation method across most outcome measurement tools. Additionally, there are consistencies in MCID calculation methods, because most authors used an anchor question with a Likert scale for the anchor-based approach or used one-half the standard deviation of preoperative and postoperative PROM score differences for the distribution-based approach. For some of the most frequently reported MCIDs, however, anchor-based values tend to be larger than distribution-based values for their respective PROMs. Clinical Relevance We recommend using a 9-point increase as the MCID for the OHS, consistent with the median reported anchor-based value derived from several high-quality studies with large patient groups that used anchor-based approaches for MCID calculations, which we believe are most appropriate for most applications in clinical research. Likewise, we recommend using the anchor-based 33-point and 25-point MCIDs for the HOOS Pain and Quality of Life subscores, respectively. We encourage using anchor-based MCID values of WOMAC Pain, Function, and Stiffness subscores, which were 29, 26, and 30, respectively.

AbstractBackgroundInnovations in machined and three‐dimensionally (3D) printed implant technology have allowed for customized complex pelvic reconstructions. We sought to determine the survivorship of custom hemipelvis reconstruction using ilium‐only fixation at a minimum 2‐year follow‐up, their modes of failure, and the postoperative complications resulting from the procedure.MethodsA retrospective review identified 12 consecutive patients treated with custom hemipelvis reconstruction. Indications for surgery were bone tumor requiring internal hemipelvectomy (four patients) or multiply revised, failed hip arthroplasty with massive bone loss (eight patients). All patients had a minimum of 2‐year follow‐up with a mean of 60.5 months. Kaplan–Meier survivorship analysis was determined for all patients. Postoperative complications and reoperations were categorized for all patients.ResultsAt a mean of 60.5 months, 11 of 12 patients had retained their custom implant (92% survivorship). One implant was removed as a result of an acute periprosthetic joint infection (PJI). There were no cases of aseptic loosening. Seven of 12 patients required reoperation (three PJI; two dislocations; two superficial wound complications), with five patients going on to reoperation‐free survival.ConclusionsCustom hemipelvis reconstruction utilizing an ilium monoflange provides durable short‐term fixation at a minimum 2‐year follow‐up. Reoperation for infection and dislocation is common.

Abstract Background Patient-reported outcome measures (PROMs) are frequently used to assess the impact of total knee arthroplasty (TKA) on patients. However, mere statistical comparison of PROMs is not sufficient to assess the value of TKA to the patient, especially given the risk profile of arthroplasty. Evaluation of treatment effect sizes is important to support the use of an intervention; this is often quantified with the minimum clinically important difference (MCID). MCIDs are unique to specific PROMs, as they vary by calculation methodology and study population. Therefore, a systematic review of calculated MCID values, their respective ranges, and assessment of their applications is important to guide and encourage their use as a critical measure of effect size in TKA outcomes research. Questions/purposes In this systematic review of MCID calculations and reporting in primary TKA, we asked: (1) What are the most frequently reported PROM MCIDs and their reported ranges in TKA? (2) What proportion of studies report distribution- versus anchor-based MCID values? (3) What are the most common methods by which these MCID values are derived for anchor-based values? (4) What are the most common derivation methods for distribution-based values? (5) How do the reported medians and corresponding interquartile ranges (IQR) compare between calculation methods for each PROM? Methods Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review was conducted using the PubMed, EMBASE, and MEDLINE databases from inception through March 2022 for TKA articles reporting an MCID value for any PROMs. Two independent reviewers screened articles for eligibility, including any article that calculated new MCID values for PROMs after primary TKA, and extracted these data for analysis. Overall, 576 articles were identified, 38 of which were included in the final analysis. These studies had a total of 710,128 patients with a median age of 67.7 years and median BMI of 30.9 kg/m 2 . Women made up more than 50% of patients in most studies, and the median follow-up period was 17 months (range 0.25 to 72 months). The overall risk of bias was assessed as moderate using the Jadad criteria for one randomized controlled trial (3 of 5 ideal global score) and the modified Methodological Index for Non-randomized Studies criteria for comparative studies (mean 17.2 ± 1.8) and noncomparative studies (mean 9.6 ± 1.3). There were 49 unique PROMs for which 233 MCIDs were reported. Calculated values were classified as anchor-based, distribution-based, or not reported. MCID values for each PROM, MCID calculation method, number of patients, and study demographics were extracted from each study. Anchor-based and distribution-based MCIDs were compared for each unique PROM using a Wilcoxon rank sum test given non-normal distribution of values. Results The WOMAC Function and Pain subscores were the most frequently reported MCID value, comprising 9% (22 of 233) and 9% (22 of 233), respectively. The composite Oxford Knee Score (OKS) was the next most frequently reported (9% [21 of 233]), followed by the WOMAC composite score (6% [13 of 233]). The median anchor-based values for WOMAC Function and Pain subscores were 23 (IQR 16 to 33) and 25 (IQR 14 to 31), while the median distribution-based values were 11 (IQR 10.8 to 11) and 22 (IQR 17 to 23), respectively. The median anchor-based MCID value for the OKS was 6 (IQR 4 to 7), while the distribution-based value was 7 (IQR 5 to 10). Thirty-nine percent (15 of 38) used an anchor-based method to calculate a new MCID, while 32% (12 of 38) used a distribution-based technique. Twenty-nine percent of studies (11 of 38) calculated MCID values using both methods. For studies reporting an anchor-based calculation method, a question assessing patient satisfaction, pain relief, or quality of life along a five-point Likert scale was the most commonly used anchor (40% [16 of 40]), followed by a receiver operating characteristic curve estimation (25% [10 of 40]). For studies using distribution-based calculations, all articles used a measure of study population variance in their derivation of the MCID, with the most common method reported as one-half the standard deviation of the difference between preoperative and postoperative PROM scores (45% [14 of 31]). Most reported median MCID values (15 of 19) did not differ by calculation method for each unique PROM (p > 0.05) apart from the WOMAC Function component score and the Knee Injury and Osteoarthritis Outcome Score Pain and Activities of Daily Living subscores. Conclusion Despite variability of MCIDs for each PROM, there is consistency in the methodology by which MCID values have been derived in published studies. Additionally, there is a consensus about MCID values regardless of calculation method across most of the PROMs we evaluated. Clinical Relevance Given their importance to treatment selection and patient safety, authors and journals should report MCID values with greater consistency. We recommend using a 7-point increase as the MCID for the OKS, consistent with the median reported anchor-based value derived from several high-quality studies with large patient groups that used anchor-based approaches for MCID calculation, which we believe are most appropriate for most applications in clinical research. Likewise, we recommend using a 10-point to 15-point increase for the MCID of composite WOMAC, as the median value was 12 (IQR 10 to 17) with no difference between calculation methods. We recommend use of median reported values for WOMAC function and pain subscores: 21 (IQR 15 to 33) and 23 (IQR 13 to 29), respectively.

» There are limited data that directly compare the efficacy of antiseptic irrigation solutions used for the prevention and treatment of periprosthetic joint infections in orthopaedic procedures; there is a notable lack of prospective data. » For prevention of periprosthetic joint infections, the strongest evidence supports the use of low-pressure povidone-iodine. » For the treatment of periprosthetic joint infections, delivering multiple solutions sequentially may be beneficial.

In the setting of below-knee amputation, compartment syndrome is a rare complication. Early clinical symptoms of an acute compartment syndrome following below-knee amputation can mimic or be masked by postoperative pain management. We present the case of a 38-year-old male with a significant past medical history of Proteus syndrome who underwent an elective transtibial below-knee amputation. Following surgery, the patient had extensive postoperative pain and high pain medication requirements and returned to the operating room for irrigation and debridement due to suspicion of an infection. Upon return to the operating room to manage the infection, the necrotic tissue was discovered and removed which had developed due to a suspected missed acute compartment syndrome. The necrotic tissue secondary to the compartment syndrome subsequently resulted in infection. Multiple irrigation and debridement procedures were performed to further manage the infection, and ultimately, the patient was deemed stable for discharge. Acute compartment syndrome (ACS) following below-knee amputation (BKA) is a rarely documented but critical complication. This case describes the unique setting in which a compartment syndrome can be masked due to postoperative pain management and infection. Orthopedic surgeons should be aware of the varying risk factors and presentations of an acute compartment syndrome (ACS) as it can occur and is a devastating complication.