Clarke, Henry D.

AbstractIntroductionThe optimal alignment technique for total knee replacement (TKR) remains controversial. We previously reported six-month and two-year results of a randomized controlled trial comparing kinematically (KA) versus mechanically (MA) aligned TKR. In the present study, we report 12-year results from this trial.MethodsThe original cohort included 88 TKRs (44 KA using Shape Match patient-specific guides and 44 MA using conventional instrumentation), performed from 2008 to 2009. After IRB approval, the health record of the original 88 patients were queried. Revisions, re-operations, and complications were recorded. The non-deceased patients were contacted via phone. Reoperation and complications were documented via the patient's history. Further, a battery of patient-reported outcome measures (including patient satisfaction, WOMAC, Oxford, KOOS Jr, Forgotten Joint Score, and M-SANE) were obtained.ResultsOf the original 88 patients in the study, 15 patients had a least one reoperation (17%). Patella problems were the most common cause of reoperation accounting for 5/8 reoperations in the KA group versus 3/7 in the MA group. There was no statistically significant difference between the two alignment methods in terms of major and minor complications or reoperations. At the 12-year follow-up, 26 patients died leaving 62 patients for follow-up. Of these, 48 patients (77%) were successfully contacted. The kinematically aligned total knees self-reported better satisfaction (96% versus 82%), but no difference in other patient-reported outcome measures compared to mechanically aligned TKRs.ConclusionKA TKR demonstrates excellent mid to long-term results compared to MA TKR with similar reoperations, complications, and patient-reported outcome measures.

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.

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.

Introduction. This case report adds to current literature on management of a subdural hematoma following total knee arthroplasty and is particularly important as joint replacement moves into outpatient surgery centers where the orthopedic surgery team becomes the sole patient contact point. Case Presentation. A 66-year-old male presented to the emergency department five days after elective robotic-assisted left total knee arthroplasty performed with spinal epidural with the symptoms of a persistent nonpostural headache. CT of the head revealed a small bifrontal acute subdural hematoma. He was admitted for overnight monitoring as a precaution. No vascular abnormalities or underlying pathology was found on further advanced imaging. He was discharged the following morning after follow-up CT showed no focal changes. Magnetic resonance imaging (MRI) one month later confirmed resolution of the subdural hematoma. Conclusion. Orthopedic surgeons should be aware of the signs and symptoms, as well as the risk factors for subdural hematomas following lumbar puncture, as it is a rare, but potentially life-threatening complication of spinal epidural.

Aims Robotic-assisted total knee arthroplasty (RA-TKA) is theoretically more accurate for component positioning than TKA performed with mechanical instruments (M-TKA). Furthermore, the ability to incorporate soft-tissue laxity data into the plan prior to bone resection should reduce variability between the planned polyethylene thickness and the final implanted polyethylene. The purpose of this study was to compare accuracy to plan for component positioning and precision, as demonstrated by deviation from plan for polyethylene insert thickness in measured-resection RA-TKA versus M-TKA. Methods A total of 220 consecutive primary TKAs between May 2016 and November 2018, performed by a single surgeon, were reviewed. Planned coronal plane component alignment and overall limb alignment were all 0° to the mechanical axis; tibial posterior slope was 2°; and polyethylene thickness was 9 mm. For RA-TKA, individual component position was adjusted to assist gap-balancing but planned coronal plane alignment for the femoral and tibial components and overall limb alignment remained 0 ± 3°; planned tibial posterior slope was 1.5°. Mean deviations from plan for each parameter were compared between groups for positioning and size and outliers were assessed. Results In all, 103 M-TKAs and 96 RA-TKAs were included. In RA-TKA versus M-TKA, respectively: mean femoral positioning (0.9° (SD 1.2°) vs 1.7° (SD 1.1°)), mean tibial positioning (0.3° (SD 0.9°) vs 1.3° (SD 1.0°)), mean posterior tibial slope (-0.3° (SD 1.3°) vs 1.7° (SD 1.1°)), and mean mechanical axis limb alignment (1.0° (SD 1.7°) vs 2.7° (SD 1.9°)) all deviated significantly less from the plan (all p < 0.001); significantly fewer knees required a distal femoral recut (10 (10%) vs 22 (22%), p = 0.033); and deviation from planned polyethylene thickness was significantly less (1.4 mm (SD 1.6) vs 2.7 mm (SD 2.2), p < 0.001). Conclusion RA-TKA is significantly more accurate and precise in planning both component positioning and final polyethylene insert thickness. Future studies should investigate whether this increased accuracy and precision has an impact on clinical outcomes. The greater accuracy and reproducibility of RA-TKA may be important as precise new goals for component positioning are developed and can be further individualized to the patient. Cite this article: Bone Joint J 2021;103-B(6 Supple A):74–80.

Background: Debridement and implant retention (DAIR) has variable success as a treatment for acute periprosthetic joint infection (PJI), with generally poor outcomes reported in the literature 1 . Because of the unacceptably high failure rate of DAIR, we implemented a 2-stage debridement protocol that includes the use of high-dose antibiotic beads between stages for the treatment of acute PJI. In 2 previous studies, with an average follow-up of 3.5 years in each study, we reported overall infection-control rates of 87% and 90% 2,3 . Description: Following exposure of the joint, cultures are obtained, and all modular components are removed, scrubbed, and soaked in an antiseptic solution. A thorough irrigation and debridement with complete synovectomy is performed, followed by temporary reinsertion of the original modular parts. High-dose antibiotic cement beads are inserted into the joint, and the joint is closed. Approximately 5 to 6 days later, a second debridement is performed, the beads are removed, and the new modular, sterile components are implanted. The patient is placed on a course of intravenous and, later, oral antibiotics, in addition to a standard postoperative rehabilitation protocol. Alternatives: Long-term suppressive antibiotic therapy. One-stage DAIR. One-stage exchange arthroplasty. Two-stage exchange arthroplasty. Resection arthroplasty. Amputation. Rationale: The treatment of acute PJI has historically consisted of a single irrigation and debridement, with exchange of modular parts and retention of the components, followed by intravenous antibiotic therapy. Despite having lower rates of patient morbidity compared with a 2-stage exchange arthroplasty, this more traditional procedure also has a higher rate of failure, with reported rates as high as 60% to 84% 4–12 . The utility of component retention continues to be a topic of debate 13 . Alternatives to component retention include both 1- and 2-stage exchange procedures. Although these modalities offer potentially higher rates of infection control, they are associated with substantial patient morbidity, particularly in patients with well-fixed implants 14–16 . Furthermore, exchange procedures may result in substantial iatrogenic bone loss, which can be problematic in revision total joint arthroplasty procedures, in which bone stock may already be limited. The double-DAIR protocol offers infection-control rates that are comparable with those of component-exchange procedures, but with the lower patient morbidity associated with component-retention procedures. Furthermore, the double-DAIR procedure provides the added benefit of retaining important bone stock. Expected Outcomes: The success rate for the double-DAIR procedure has been reproducible, with infection-control rates of 87% and 90% reported in 2 studies from a single cohort at our institution 2,3 . These rates represent a substantial improvement compared with a single irrigation and debridement 1 , and are on par with those reported for 2-stage exchange arthroplasty procedures 17–21 . The infection-control rates of the double-DAIR procedure did not significantly vary depending on whether infection occurred following a total knee or total hip arthroplasty. However, not surprisingly, patients who underwent debridement following a revision procedure had a lower rate of success (77.1% successful infection control) compared with patients debrided following a primary procedure (93.8% successful infection control). We could not demonstrate an association with organism and success or failure of treatment. Although not significant, there was a trend toward an association between the time from symptom onset to initial treatment and infection control (p = 0.07) 2 . Patients with successful infection control underwent the initial debridement an average of 6.2 days after symptom onset, compared with 10.7 days in patients in whom treatment had failed. Several other studies have demonstrated that successful infection control is associated with earlier initial irrigation and debridement 22–27 . We strongly support that, in the setting of confirmed acute PJI, prompt initiation of treatment optimizes the chances for successful infection control. Important Tips: Thorough debridement is key to successful infection control of infection. Antibiotic-loaded bone cement has repeatedly been demonstrated to be safe, and we recommend its use 28–31 . Extended oral antibiotics following debridement with component retention can increase infection-free survivorship 32 .

Background: Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA), and perioperative antibiotics are commonly administered to try to mitigate the chance of infection. Intraosseous regional administration (IORA) of prophylactic antibiotics during TKA is a method of antibiotic delivery that has been shown to achieve markedly higher tissue concentrations at much lower doses. Other advantages include ease of administration, ability to time the antibiotic delivery with the surgical start time for maximal effectiveness, and less systemic side effects. The concept is similar to a Bier block, except that IORA involves the use of antibiotics instead of local anesthetic to perfuse the limb and is given via intraosseous rather than intravenous access. Description: After standard patient preparation and draping, the tourniquet is inflated and an intraosseous needle is inserted into the proximal medial face of the tibia, just medial and slightly above the level of the tubercle. A large syringe containing the desired antibiotic (typically 500 mg vancomycin suspended in normal saline solution) is connected to the needle and the solution is administered over 1 to 2 minutes. The intraosseous needle can then be removed and the surgical procedure proceeds as it normally would per surgeon preference and technique. Alternatives: Systemic administration of intravenous antibiotics, vancomycin powder, and antibiotic-impregnated cement are alternative options that can be utilized during TKA. Rationale: IORA has several distinct advantages over other methods of antibiotic delivery, including the ability to (1) deliver antibiotic directly to the surgical bed and avoid systemic delivery, (2) precisely time and quickly administer antibiotics to achieve highest concentrations at the start of and throughout the surgical procedure, and (3) avoid several common and potentially serious side effects, especially those associated with antibiotics such as vancomycin. Expected Outcomes: This technique for antibiotic delivery achieves markedly higher tissue concentrations compared with systemic administration, without prolonged preoperative infusion times. Intraosseous delivery optimizes timing and reduces the risk of systemic side effects while simultaneously providing equal or enhanced antibiotic prophylaxis in TKA. This delivery mechanism is especially useful in patients who are at high risk for infection and in the revision TKA setting. Further, there is little to no additional risk and the use of this method does not substantially prolong operative time. Important Tips: The proximal aspect of the tibia is the optimal injection site because the cortex is thinner in this region, making needle insertion easier. Additionally, the metaphyseal bone allows faster flow rates for the infusion. We have found that insertions made slightly more proximally are easier and have faster flow rates. Of note, although the antibiotic is infused into the tibia, as seen in the attached technique video, intraosseous administration achieves rapid uptake into the vascular tree. Therefore, all tissues distal to the tourniquet, including the femur and patella, will receive this optimal dose as well. We prefer the use of a power driver (EZ-IO; Teleflex); however, manual needles (Cook Medical) can also be utilized. Longer needles are available if needed for obese patients. Flow rates are variable and the infusion typically takes 1 to 2 minutes to complete. If the flow rate is slow, twisting and withdrawing the needle slightly (2 to 4 mm) may increase the rate. This contrasts with the 1 to 2-hour intravenous infusion time required when vancomycin is administered systemically. In our experience, intraosseous injection is still successful in the case of a previous high tibial osteotomy, although the flow rate may be slower. In complex revision cases with compromised proximal tibial bone, the medial malleolus is an alternative site for intraosseous administration. Choice of antibiotic: as vancomycin is difficult to adequately administer intravenously, it is ideally suited for IORA. We have studied and utilized a 500-mg dose of vancomycin suspended in a solution of 140 mL of normal saline solution (prepared by our pharmacy). Of note, we have not found rapid infusion of intraosseous vancomycin to cause red-man syndrome as it would with rapid systemic infusion. This is because of the lower dose of 500 mg and the use of the tourniquet, which keeps the antibiotic in the local tissues about the knee without allowing systemic exposure. All patients, regardless of weight or the size of their limb, receive the dose of 500 mg of vancomycin. As cefazolin does not have the same difficulties with intravenous administration, we continue to use standard intravenous prophylaxis with an appropriate weight-based dose of cefazolin prior to incision. Indications for IORA of vancomycin include clinical scenarios in which vancomycin would be administered intravenously. These indications include revision TKA, obesity (body mass index >40 kg/m 2 ), diabetes, beta-lactam allergy, known colonization with methicillin-resistant Staphylococcus aureus (MRSA) , patients coming from institutions with a high prevalence of MRSA , previous ligamentous surgical procedure or osteotomies, and current or recent smokers. IORA can be utilized even in the primary TKA setting if the patient is considered high-risk as defined by the criteria above. We also use IORA during reimplantation following 2-stage exchange for PJI and in patients undergoing irrigation and debridement for acute PJI when the organism has been identified preoperatively.