Increasing Body Mass Index Not Associated With Worse Patient-Reported Outcomes After Primary THA or TKA.

INTRODUCTION: As the US obesity epidemic continues to grow, so too does comorbid hip and knee arthritis. Strict body mass index (BMI) cutoffs for total hip and knee arthroplasty (THA and TKA) in the morbidly obese have been proposed and remain controversial, although current American Academy of Orthopaedic Surgeons guidelines recommend a BMI of less than 40 m/kg2 before surgery. This study sought to compare patient-reported outcomes and 30-day complication, readmission, and revision surgery rates after THA or TKA between morbidly obese patients and nonmorbidly obese control subjects. METHODS: All patients undergoing primary THA and TKA at our institution from May 2020 to July 2022 were identified. Patient demographics, surgical time, length of stay and 30-day readmission, revision surgery, and complication rates were prospectively collected. Preoperative and postoperative Hip and Knee Society (Hip Osteoarthritis Outcome Score [HOOS] and Knee Osteoarthritis Outcome Score [KOOS]) were collected. Patients were stratified by BMI as ideal weight (20 to 24.9), overweight (25 to 29.9), class I obese (30 to 34.9), class II obese (35 to 39.9), and morbidly obese (>40 m/kg2). RESULTS: A total of 1,423 patients were included for final analysis. No difference was observed in 30-day unplanned return to emergency department, readmission, or revision surgery in the morbidly obese cohort. Morbidly obese patients undergoing THA had lower preoperative HOOS (49.5 versus 54.5, P = 0.004); however, there was no difference in postoperative HOOS or KOOS at 12 months across all cohorts. DISCUSSION: No difference was observed in 30-day return to emergency department, readmission, or revision surgery in the morbidly obese cohort. Despite a lower preoperative HOOS, there was no difference in 12-month HOOS or KOOS when stratified by BMI. These findings suggest that such patients may achieve similar benefit from arthroplasty as their ideal weight counterparts.

Early Tibial Baseplate Fracture After Medial Unicondylar Knee Arthroplasty: A Report of 2 Cases.

CASE: Implant failure after unicondylar knee arthroplasty (UKA) is a rare but well-described complication in the arthroplasty literature. However, there is a paucity of literature regarding rapid catastrophic failure of modern implant designs. This is a case report of 2 patients with early catastrophic failure of the tibial baseplate after UKA with a Stryker Restoris MultiCompartmental Knee System implant using Mako robotic assistance, both requiring revision to total knee arthroplasty. CONCLUSION: Improved awareness and understanding of early UKA tibial baseplate failure may help identify both patient and surgical risk factors that could help prevent further instances in the future.

Acetabular fixation in total hip arthroplasty in the previously irradiated pelvis: a review of basic science and clinical outcomes.

Radiation therapy is a common primary, adjuvant, or palliative treatment for many intrapelvic tumors, including primary gastrointestinal, genitourinary, and hematopoietic tumors, as well as metastatic disease to bone. Radiation has well documented microbiologic and clinical effects on bone ranging from radiation osteitis to early degenerative changes of the hip joint and avascular necrosis of the femoral head. Conventional total hip arthroplasty methods have demonstrated high rates of failure in this population, with historical data describing aseptic loosening rates as high as 44-52%, as radiation have been shown to preferentially diminish osteoblast and osteocyte number and function and limit capacity for both cement interdigitation and biologic bony ingrowth. A review of the clinical literature suggests that patients with prior pelvic irradiation are at higher risk for both septic and aseptic loosening of acetabular components, as well as lower postoperative Harris Hip Score (HHS) when compared to historical controls. With limited evidence, trabecular metal shells with multi-screw fixation and cemented polyethene liners, as well as cemented cup-cage constructs both appear to be durable acetabular fixation options, though the indications for each remains elusive. Further prospective data are needed to better characterize this difficult clinical problem.

The Role of the Innate Immune System in Wear Debris-Induced Inflammatory Peri-Implant Osteolysis in Total Joint Arthroplasty.

Periprosthetic osteolysis remains a leading complication of total hip and knee arthroplasty, often resulting in aseptic loosening of the implant and necessitating revision surgery. Wear-induced particulate debris is the main cause initiating this destructive process. The purpose of this article is to review recent advances in understanding of how wear debris causes osteolysis, and emergent strategies for the avoidance and treatment of this disease. A strong activator of the peri-implant innate immune this debris-induced inflammatory cascade is dictated by macrophage secretion of TNF-α, IL-1, IL-6, and IL-8, and PGE2, leading to peri-implant bone resorption through activation of osteoclasts and inhibition of osteoblasts through several mechanisms, including the RANK/RANKL/OPG pathway. Therapeutic agents against proinflammatory mediators, such as those targeting tumor necrosis factor (TNF), osteoclasts, and sclerostin, have shown promise in reducing peri-implant osteolysis in vitro and in vivo; however, radiographic changes and clinical diagnosis often lag considerably behind the initiation of osteolysis, making timely treatment difficult. Considerable efforts are underway to develop such diagnostic tools, therapies, and identify novel targets for therapeutic intervention.

Outcomes of reverse shoulder arthroplasty following failed superior capsular reconstruction.

BACKGROUND: Superior capsular reconstruction (SCR) can be used for massive irreparable rotator cuff tears in the absence of significant degenerative changes; however, those who fail an SCR may require reverse shoulder arthroplasty (RSA). The effect of a previously performed SCR on outcomes following RSA remains unknown. METHODS: Subjects who underwent RSA from May 2015 to January 2021 at 2 separate institutions were retrospectively identified through prospectively collected databases. Patients who underwent RSA after failed SCR were matched to those who underwent RSA after failed rotator cuff repair (RCR) based on the number of previous ipsilateral shoulder procedures (n = 1, 2, ≥3) and secondarily by age within 5 years. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, Single Assessment Numeric Evaluation (SANE), visual analog scale (VAS) for pain, and Western Ontario Osteoarthritis of the Shoulder index (WOOS) scores were compared between groups. The minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) thresholds were calculated to determine clinically relevant differences between groups. RESULTS: Forty-five patients were included (32 RSA following RCR, 13 following SCR). There were more smokers (P = .001) and worker's compensation cases (P = .034) in the SCR group. The RCR cohort was older (P = .007) and had a greater incidence of mental health (P > .999) and somatic disorders (P = .698), although these did not reach statistical significance. The mean follow-up for the RCR and SCR groups were 24.2 ± 23.3 and 20.4 ± 14.9 months following RSA, respectively (P = .913). The time from index RCR or SCR to RSA were 94.4 ± 22.2 and 89.2 ± 5.3 months, respectively (P = .003). Pre- and postoperative range of motion were similar between groups, as was the overall change in forward flexion (P = .879), abduction (P = .971), and external rotation (P = .968) following RSA. The RCR group had lower postoperative VAS pain (P = .009), higher SANE (P = .015), higher ASES (P = .008), and higher WOOS (P = .018) scores. The percentage achieving the MCID (P = .676) and SCB (P > .999) were similar; however, 56.7% of the RCR group met the SANE PASS threshold compared with 0.0% in the SCR group (P = .005). There were no differences in postoperative complications (P = .698) or revision rates (P = .308) following RSA between cohorts. CONCLUSION: When matched for number of previous procedures to the ipsilateral extremity and age, patients who underwent RSA following failed SCR had worse clinical outcome scores than their RSA following failed RCR counterparts. No patient in the SCR group met the SANE PASS threshold, whereas more than half of the RCR group did.

Transamniotic stem cell therapy (TRASCET) in a leporine model of gastroschisis.

BACKGROUND/PURPOSE: Transamniotic stem cell therapy (TRASCET) with amniotic fluid mesenchymal stem cells (afMSCs) has been shown to mitigate bowel damage in a rodent model of gastroschisis. As a prerequisite to clinical translation, we sought to study TRASCET in a larger animal model. METHODS: New Zealand rabbit fetuses (n=64) with surgically created gastroschisis were divided into three groups. One group (untreated) had no further manipulations. Two groups received volume-matched intraamniotic injections of either saline or a suspension of afMSCs. Nonmanipulated fetuses served as controls. Histomorphologic measurements of intestinal damage, along with biochemical profiling of inflammation markers, were performed at term. Statistical comparisons were by Fisher's exact test, ANOVA and the Wald test (P<0.05). RESULTS: Overall survival was 62.5%. Segmental and total intestinal wall thicknesses were significantly decreased in the afMSC group compared with the untreated and saline groups (all P<0.001), with no significant differences between untreated and saline groups (P=0.24 to 1.00, depending on layer). Muscularis and serosal layers were significantly thicker in the afMSC group than in normal controls (P=0.045 and P<0.001, respectively). CONCLUSIONS: Concentrated intraamniotic injection of afMSC lessens, yet does not prevent, intestinal damage in a leporine model of gastroschisis. TRASCET may become a valuable strategy in the management of gastroschisis. LEVEL OF EVIDENCE: N/A - animal/experimental studies.

A comparison between placental and amniotic mesenchymal stem cells for transamniotic stem cell therapy (TRASCET) in experimental spina bifida.

PURPOSE: We compared placental-derived and amniotic fluid-derived mesenchymal stem cells (pMSCs and afMSCs, respectively) in transamniotic stem cell therapy (TRASCET) for experimental spina bifida. METHODS: Pregnant dams (n=29) exposed to retinoic acid for the induction of fetal spina bifida were divided into four groups. Three groups received volume-matched intraamniotic injections of either saline (n=38 fetuses) or a suspension of 2×10(6) cells/mL of syngeneic, labeled afMSCs (n=73) or pMSCs (n=115) on gestational day 17 (term=21-22days). Untreated fetuses served as controls. Animals were killed before term. Statistical comparisons were by Fisher's exact test (p<0.05). RESULTS: Survival was similar across treatment groups (p=0.08). In fetuses with isolated spina bifida (n=100), there were higher percentages of defect coverage (either partial or complete) in both afMSC and pMSC groups compared with saline and untreated groups (p<0.001-0.03 in pairwise comparisons). There were no differences in coverage rates between afMSC and pMSC groups (p=0.94) or between saline and untreated groups (p=0.98). CONCLUSIONS: Both pMSC and afMSC can induce comparable rates of coverage of experimental spina bifida after concentrated intraamniotic injection in the rodent model. This broadens the options for timing and cell source for TRASCET as a potential alternative in the prenatal management of spina bifida.

Transamniotic stem cell therapy (TRASCET) mitigates bowel damage in a model of gastroschisis.

PURPOSE: We sought to determine whether intraamniotic delivery of concentrated amniotic-derived mesenchymal stem cells (afMSCs) could reduce damage to exposed bowel in experimental gastroschisis. METHODS: Rat fetuses (n=117) with surgically created gastroschisis were divided into three groups: untreated animals (n=62) and two groups receiving volume-matched intraamniotic injections of either saline (n=25) or 2 × 10(6) cells/mL of syngeneic, labeled afMSCs (n=30). Animals were killed before term, along with normal controls (NL). Blinded observers performed computerized measurements of total and segmental (serosa, muscularis, and mucosa) intestinal wall thicknesses. Statistical comparisons were by ANOVA (P<0.05). RESULTS: Among survivors with gastroschisis, there were statistically significant decreases in total bowel wall, serosal, muscular, and mucosal thicknesses in the afMSC group vs. the untreated group (P=0.001/0.035/0.001/0.005, respectively) and vs. the saline group (P=0.003/0.05/<0.001/0.026, respectively). There were no such significant differences between the untreated and saline groups. There were no differences between the afMSC group and NL, except for a significantly thicker muscular layer in the afMSC group (P=0.014). Labeled afMSCs were scarcely identified, suggesting a paracrine effect. CONCLUSIONS: Amniotic mesenchymal stem cells mitigate bowel damage in experimental gastroschisis after concentrated intraamniotic injection. Transamniotic stem cell therapy (TRASCET) may become a practical component of the treatment of gastroschisis.

Partial or complete coverage of experimental spina bifida by simple intra-amniotic injection of concentrated amniotic mesenchymal stem cells.

PURPOSE: We sought to determine whether simple intra-amniotic delivery of concentrated amniotic mesenchymal stem cells (afMSCs) may elicit prenatal coverage of experimental spina bifida. METHODS: Time-dated pregnant Sprague-Dawley dams (n=24) exposed to retinoic acid for the induction of fetal neural tube defects were divided in three groups. Group I had no further manipulations. Groups II and III received volume-matched intra-amniotic injections of either saline (Group II) or a suspension of syngeneic afMSCs labeled with green fluorescent protein (Group III) in all fetuses (n=202) on gestational day 17 (term=21-22 days). Animals were killed before term. Statistical comparisons were by ANOVA (P<0.05). RESULTS: Of 165 fetuses viable at euthanasia, a spina bifida was present in 58% (96/165), with no significant differences in defect dimension across the groups (P=0.19). However, variable degrees of coverage of the defect by a rudimentary skin confirmed histologically were only present in Group III (P<0.001), in which donor afMSCs were documented, with no differences between Groups I and II (P=0.98). CONCLUSIONS: Amniotic mesenchymal stem cells can induce partial or complete coverage of experimental spina bifida after concentrated intra-amniotic injection. Trans-amniotic stem cell therapy (TRASCET) may become a practical option in the prenatal management of spina bifida.

Extraluminal helicoidal stretch (Helixtretch): a novel method of intestinal lengthening.

PURPOSE: We sought to test a novel, extraluminal method of intestinal lengthening that precludes violation of the intestinal wall. METHODS: Sprague-Dawley rats (n=45) with size-matched bowel segments isolated by Roux-en-Y reconstruction were divided into three groups. Group 1 (n=14) had no further manipulations. In Groups 2 (n=12) and 3 (n=19), the isolated segment was wrapped around a length-matched device in a helicoidal fashion. In Group 2, the device consisted of plain polyurethane tubing. In Group 3, it consisted of a gradually expanding hygroscopic hydrogel (12.5mm final diameter). Euthanasia was performed at 8-21 days. Statistical analysis was by two-way ANOVA (P<0.05). RESULTS: Overall survival was 87% (39/45). There was a statistically significant increase in bowel length in Group 3 compared to the other two groups (P<0.001). This increase correlated with the number of helicoidal coils (P=0.018), but not with post-operative time (P>0.50). There were no significant differences in total DNA/protein ratio across the groups (P=0.65). Histologically, there was an apparent increase in the goblet cell density in Group 3. CONCLUSIONS: Measured extraluminal helicoidal stretch (Helixtretch) is tolerated by the intestine. Helixtretch induces bowel lengthening in a rodent model. Further analysis of this novel, minimally invasive alternative for intestinal augmentation is warranted.