An Overview of Research for the Application of a Novel Biofilm-Preventing Surgical Irrigation System for Total Joint Arthroplasty Procedures in Order to Reduce the Risk of Periprosthetic Infection.

Periprosthetic joint infection (PJI) is a serious postoperative complication in joint arthroplasty procedures that carries substantial morbidity and mortality associated with it. Several strategies have been developed both in the preoperative, perioperative, and postoperative periods to both combat and prevent the development of this devastating complication. Intraoperative irrigation is an important modality used during arthroplasty procedures prior to the implantation of final components that seeks to eradicate any biofilm formation. In this updated review, we discuss the XPERIENCE™ Advanced Surgical Irrigation solution (Next Science, Jacksonville, Florida) and the various completed, ongoing, and planned basic science and clinical investigations associated with it. Although there is already an impressive body of literature supporting its widespread utilization, future basic and clinical trials will continue to be performed to comprehensively characterize the effect this antimicrobial solution has on eliminating the risk of PJI following arthroplasty procedures.

Can Robotic-Arm Assistance Decrease Iatrogenic Soft-Tissue Damage During Direct Anterior Total Hip Arthroplasty?

INTRODUCTION: Manual techniques for total hip arthroplasty (THA) have been widely utilized and proven to be clinically successful. However, the use of advanced computed tomography (CT) scan-based planning and haptically-bounded reamers in robotic-arm assisted total hip arthroplasty (RTHA) holds promise for potentially limiting surrounding soft-tissue damage. This cadaver-based study aimed to compare the extent of soft-tissue damage between a robotic-arm assisted, haptically-guided THA (RTHA) and a manual, fluoroscopic-guided THA (MTHA) direct anterior approach. MATERIALS AND METHODS: There were six fresh-frozen torso-to-toe cadaver specimens included, with two surgeons each performing three RTHA and three MTHA procedures. One hip underwent an RTHA and the other hip received an MTHA in each cadaver. Postoperatively, one additional surgeon, blinded to the procedures, assessed and graded damage to nine key anatomical structures using a 1 to 4 grading scale: (1) complete soft-tissue preservation to <5% of damage; (2) 6 to 25% of damage; (3) 26 to 75% of damage; and (4) 76 to 100% of damage. Kruskal-Wallis hypothesis tests were used to compare soft-tissue damage between RTHA and MTHA cases and adjusted for ties. RESULTS: Pooled analysis of the gluteus minimus, sartorius, tensor fascia lata, and vastus lateralis muscle grades demonstrated that cadaver specimens who underwent RTHA underwent less damage to these structures than following MTHA (median, IQR: 1.0, 1.0 to 2.0 vs. 3.0, 2.0 to 3.0; p=0.003). Pooled analysis of the calculated volumetric damage (mm3) for the gluteus minimus, sartorius, tensor fascia lata, and vastus lateralis muscles demonstrated that the cadaver specimens that underwent RTHA underwent less damage to these structures than those that followed MTHA (median, IQR: 23, 2 to 586 vs. 216, 58 to 3,050; p=0.037). CONCLUSION: This cadaver-based study suggests that utilizing RTHA may lead to reduced soft-tissue damage compared with MTHA, likely due to enhanced preoperative planning with robotic-arm assisted software, real-time intraoperative feedback, haptically-bounded reamer usage, reduced surgical steps, as well as ease of use with reaming. These findings should be carefully considered when evaluating the utilization of robotic-arm assisted THA in practice.

A Novel Strategy to Substantially Reduce the Incidence of Periprosthetic Joint Infection Following Total Hip Arthroplasty with Antimicrobial Agents.

Periprosthetic joint infections (PJI) are devastating complications following total hip arthroplasty (THA) and are the most common reason for revision following primary arthroplasty. Although several devices, techniques, and procedures have been developed to combat this serious complication, there is little consensus as to how to prevent the development of PJI at the time of index arthroplasty. This article reviews the concept and implementation of a novel antimicrobial agent to substantially reduce the incidence of PJI. The regular implementation of this infection prophylaxis should be successful in drastically reducing the rate of PJI following primary THA.

Previous Extensor Mechanism Repair Is Associated With Increased Rates of Surgical Complications Following Total Knee Arthroplasty: A Propensity-matched Analysis.

Background: Although extensor mechanism failure following total knee arthroplasty (TKA) is a devastating complication and has been heavily studied in the literature, the impact of extensor mechanism rupture and concomitant repair prior to TKA has not previously been evaluated. The purpose of this investigation was to evaluate how quadriceps and/or patellar tendon repairs prior to TKA would impact medical and surgery-related complications following TKA. Methods: The PearlDiver database was retrospectively reviewed to identify all primary TKA patients from 2010 to 2019. Patients who underwent quadriceps or patellar tendon repair prior to TKA were matched using a propensity score algorithm to a control cohort. We compared medical and surgical complication rates, emergency room visits, readmissions, and 90-day cost of care between the groups. Results: A total of 1197 patients underwent extensor mechanism repair prior to TKA and were matched to 11,970 patients who did not undergo repair prior to TKA. Patients who underwent extensor mechanism repair had higher rates of 90-day medical complications, as well as 1-year surgery-related complications including revision TKA (odds ratio [OR] 6.06; P < .001), lysis of adhesions (OR 2.18; P = .026), aseptic loosening (OR 2.21; P = .018), infection (OR 7.58; P < .001), and fracture (OR 8.53; P < .001). Patients with prior extensor mechanism repair were more likely to return to the emergency department (OR 1.66; P < .001) and become readmitted (OR 4.15; P < .001) within 90 days. Conclusions: Patients with previous extensor mechanism repair exhibited higher medical and surgery-related complications, including lysis of adhesions, following TKA than a control cohort. These findings may suggest that patients may require additional surveillance in the early postoperative period to avoid these disastrous complications following primary TKA.

Juvenile Idiopathic Arthritis is Associated With Early Medical and Surgical Complications Following Primary Total Hip Arthroplasty: A National Database Study.

Background: Juvenile idiopathic arthritis (JIA) is an inflammatory arthropathy that classically affects children but can cause long-term deformity to the femoral head and hip joint, which may require an arthroplasty procedure. There is a paucity of data surrounding the medical and surgical outcomes of total hip arthroplasty (THA) in patients with JIA compared to a control cohort. Methods: Patients with JIA who underwent THA from 2010 to 2019 were identified in a large national insurance database. A propensity score matching algorithm was used to obtain a control cohort who did not have JIA based upon age, sex, and Elixhauser Comorbidity Index in a 1:10 ratio. Seven hundred sixty-three patients with JIA and 7434 patients without JIA were identified who underwent THA. Ninety-day medical outcomes, 1-year surgical outcomes, and 90-day return to the emergency department and readmission were calculated. Results: Patients with JIA were at increased risk of 90-day transfusion (odds ratio [OR] 1.79; P < .001), pneumonia (OR 2.68; P < .001), urinary tract infection (OR 2.64; P < .001), and wound disruption (OR 2.72; P < .001), as well as 1-year risk of revision THA (OR 2.27; P < .001), periprosthetic joint infection (OR 2.98; P < .001), periprosthetic fracture (OR 2.93; P < .001), aseptic loosening (OR 3.92; P < .001), dislocation (OR 2.61; P = .001), and debridement, antibiotics, and implant retention procedure (OR 2.71; P < .001). Patients with JIA were also at increased risk of 90-day emergency department visit (OR 2.54; P < .001) and readmission (OR 2.59; P < .001). Conclusions: Patients with JIA were at increased risk of early medical and surgical complications following THA. These findings are imperative for surgeons to consider and may warrant tailored perioperative decision-making to avoid the aforementioned medical and surgical complications.

Scoliosis Without Fusion and Increased Risk of Early Medical and Surgery-Related Complications After Total Hip Arthroplasty: A Propensity-score Analysis.

INTRODUCTION: There is a paucity of literature that examines how the abnormal spinopelvic alignment of scoliosis affects outcomes after total hip arthroplasty (THA) in the absence of a lumbar fusion. METHODS: Patients with a history of scoliosis (idiopathic, adolescent, degenerative, or juvenile) without fusion and those without a history of scoliosis who underwent primary THA were identified using a large national database. Ninety-day incidence of various medical complications, emergency department (ED) visit, and readmission and 1-year incidence of surgery-related complications and cost of care were evaluated in both the scoliosis and control cohorts. Propensity score matching was used to control for patient demographic factors and comorbidities as covariates. RESULTS: After propensity matching, 21,992 and 219,920 patients were identified in the scoliosis and control cohorts, respectively. Patients with scoliosis were at increased risk of several 90-day medical complications, including pulmonary embolism (odds ratio [OR] 1.96; P < 0.001), deep vein thrombosis (1.49; P < 0.001), transfusion (OR, 1.13; P < 0.001), pneumonia (OR, 1.37; P < 0.001), myocardial infarction (OR, 1.38; P = 0.008), sepsis (OR, 1.59; P < 0.001), acute anemia (OR, 1.21; P < 0.001), and urinary tract infection (OR, 1.1; P = 0.001). Patients with a history of scoliosis were at increased 1-year risk of revision (OR, 1.31; P < 0.001), periprosthetic joint infection (OR, 1.16; P = 0.0089), dislocation (OR, 1.581; P < 0.001), and aseptic loosening (OR, 1.39; P < 0.001) after THA. Patients with scoliosis without a history of fusion were more likely to return to the emergency department (OR, 1.26; P < 0.001) and be readmitted (OR, 1.78; P < 0.001) within 90 days of THA. DISCUSSION: Patients with even a remote history of scoliosis without fusion are at increased risk of 90-day medical and surgery-related complications after hip arthroplasty. Hip and spine surgeons should collaborate in future studies to best understand how to optimize these patients for their adult reconstructive procedures.

Cemented Versus Cementless Femoral Fixation for Total Hip Arthroplasty Following Femoral Neck Fracture in Patients Aged 65 and Older.

BACKGROUND: Femoral neck fractures are common in individuals over 65, necessitating quick mobilization for the best outcomes. There's ongoing debate about the optimal femoral component fixation method in total hip arthroplasty (THA) for these fractures. Recent U.S. data shows a preference for cementless techniques in over 93% of primary THAs. Nonetheless, cemented fixation might offer advantages like fewer revisions, reduced periprosthetic fractures, lesser thigh pain, and enhanced long-term implant survival for those above 65. This study compares cementless and cemented fixation methods in THA, focusing on postoperative complications in patients aged 65 and older. METHODS: We analyzed a national database to identify patients aged 65+ who underwent primary THA for femoral neck fractures between 2016 and 2021, using either cementless (n = 2,842) or cemented (n = 1,124) techniques. A 1:1 propensity-matched analysis was conducted to balance variables such as age, sex, and comorbidities, resulting in two equally sized groups (n = 1,124 each). We evaluated outcomes like infection, venous thromboembolism (VTE), wound issues, dislocation, periprosthetic fracture, etc., at 90 days, 1 year, and 2 years post-surgery. A P-value < 05 indicated statistical significance. RESULTS: The cemented group initially consisted of older individuals, more females, and higher comorbidity rates. Both groups had similar infection and wound complication rates, and aseptic loosening. The cemented group, however, had lower periprosthetic fracture rates (2.5 versus 4.4%, P = .02) and higher VTE rates (2.9 versus 1.2%, P = .01) at 90 days. After 1 and 2 years, the cementless group experienced more aseptic revision surgeries. CONCLUSIONS: This study, using a large, national database and propensity-matched cohorts, indicates that cemented femoral component fixation in THA leads to fewer periprosthetic fractures and aseptic revisions, but a higher VTE risk. Fixation type choice should consider various factors, including age, sex, comorbidities, bone quality, and surgical expertise. This data can inform surgeons in their decision-making process.

Home health care is associated with an increased risk of readmission and cost of care without reducing risk of complication following shoulder arthroplasty: a propensity-score analysis.

BACKGROUND: Home health services provide patients with additional professional care and supervision following discharge from the hospital to theoretically reduce the risk of complication and reduce health care utilization. The aim of this investigation was to determine if patients assigned home health services following total shoulder arthroplasty (anatomic [TSA] and reverse [RSA]) exhibited lower rates of medical complications, lower health care utilization, and lower cost of care compared with patients not receiving these services. METHODS: A national insurance database was retrospectively reviewed to identify all patients undergoing primary TSA and RSA from 2010 to 2019. Patients who received home health services were matched using a propensity score algorithm to a set of similar patients who were discharged home without services. We compared medical complication rates, emergency department (ED) visits, readmissions, and 90-day cost of care between the groups. Multivariate regression analysis was performed to determine the independent effect of home health services on all outcomes. RESULTS: A total of 1119 patients received home health services and were matched to 11,190 patients who were discharged home without services. There was no significant difference in patients who received home health services compared with those who did not receive home health services with respect to rates of ED visits within 30 days (OR 1.293; P = .0328) and 90 days (OR 1.215; P = .0378), whereas the home health group demonstrated increased readmissions within 90 days (OR 1.663; P < .001). For all medical complications, there was no difference between cohorts. Episode-of-care costs for home health patients were higher than those discharged without these services ($12,521.04 vs. $9303.48; P < .001). CONCLUSION: Patients assigned home health care services exhibited higher cost of care and readmission rates without a reduction in the rate of complication or early return to the ED. These findings suggest that home health care services should be strongly analyzed on a case-by-case basis to determine if a patient may benefit from its implementation.

Decreased Risk of Periprosthetic Joint Infection with Concurrent Hardware Removal During Conversion Total Hip Arthroplasty Compared to Staged Removal: A Matched Cohort Analysis.

INTRODUCTION: Hardware removal before conversion total hip arthroplasty (cTHA) is a challenging task for the orthopaedic surgeon, although there is little consensus on the timing of hardware removal to mitigate risk of surgery-related complication following cTHA. METHODS: Using a national insurance database, we evaluated patients who underwent hardware removal either on the same day or within 1 year before cTHA, resulting in a total of 7,756 patients. After matching based on demographic factors and comorbidities, both staged and concurrent groups consisted of 2,752 patients. The 90-day and 1-year risk of revision surgery, periprosthetic joint infection (PJI), periprosthetic fracture, and aseptic loosening were calculated and compared. Demographic factors and comorbidities were further evaluated as risk factors for PJI. RESULTS: The rates of infection were 1.85% and 3.05% at 90 days postoperatively and 2.94% and 4.14% at 1 year postoperatively for concurrent versus staged cohorts, respectively (P = 0.004 and P = 0.02). No difference was observed at 90 days or 1 year between the two cohorts in risk of fracture, revision surgery, or aseptic loosening. Diabetes (P = 0.002 and P < 0.001), tobacco use (P < 0.001 and P < 0.001), and obesity (P = 0.026 and P = 0.025) were identified as risk factors for PJI at both 90 days and 1 year postoperatively. DISCUSSION: The timing of hardware removal is associated with an increased risk of PJI, although no difference was observed in revision surgery, fracture, or loosening among staged versus concurrent cohorts. These findings are important to consider when surgeons are evaluating patients with periarticular implants surrounding their hip.

Systematic Review of Complications Associated With Proximal Hamstring Tendon Repair.

Background: Although several complications of proximal hamstring tendon ruptures have been reported in the literature, few studies have comprehensively analyzed the complication profile of proximal hamstring tendon repair. Purpose: To identify the overall rate of complications following proximal hamstring tendon repair and to differentiate these complications into categories. Study Design: Systematic review; Level of evidence, 4. Methods: Included in this review were studies that examined surgical repair of proximal hamstring tendon ruptures; all studies were in English and had an evidence level of 4 or higher. No restrictions were made regarding publication date or methodological quality. Data regarding complications were extracted to calculate the overall complication rate as well as the rate of major and minor complications. A quantitative data synthesis was conducted using the chi-square test to compare the proportion of patients who experienced complications with the endoscopic versus open approach. Results: A total of 43 articles including 2833 proximal hamstring tendon repairs were identified. The overall postoperative complication rate was 15.3% (n = 433). The rate of major complications was 4.6%, including a 1.7% rate of sciatic nerve injury, 0.8% rate of venous thromboembolism, 0.8% reoperation rate, 0.8% rerupture rate, and 0.4% rate of deep infection. Minor complications included a 2.4% rate of posterior femoral cutaneous nerve injury, 2.3% rate of persistent hamstring myopathy, 2.2% rate of persistent sitting pain, 1.8% rate of peri-incisional numbness, 1.1% rate of superficial infection, and 0.8% rate of hematoma/seroma. Conclusion: Proximal hamstring tendon repair is associated with an overall complication rate of 15.3%, including a 4.6% rate of major complications.

Adjustable Cortical Fixation Repair Is a Safe and Effective Technique for Quadriceps Tendon Rupture.

Purpose: To report the clinical outcomes of quadriceps tendon repair using adjustable cortical fixation devices at a minimum 2-year follow-up. Methods: A retrospective chart review identified patients who underwent quadriceps tendon repair using adjustable cortical fixation devices between January 2017 and March 2020. Patients with a partial tendon rupture were excluded. Demographic and injury-specific variables were gathered preoperatively and postoperatively from the electronic medical record and patient-reported outcomes (Lysholm Knee Questionnaire, Lower Extremity Functional Scale, and SF-12) were collected via telephone at a minimum of 2 years postoperatively. Results: Fourteen quadriceps tendon repairs were included in a total of 13 patients. The average time to follow-up was 3.5 ± 1.2 years with a range of 1.9 to 5.7 years. The mean age of this cohort was 55.7 ± 11.6 years, and the mean body mass index was 32.9 ± 6.0. Ten injuries (71.4%) were sustained by mechanical fall, 2 patients (14.3%) suffered a direct blow to the knee, and 2 patients (14.3%) reported a noncontact injury mechanism. Thirteen quadriceps ruptures (13/14, 92.9%) underwent surgery within 10 days of their injury. One knee (7.1%) had a postoperative extensor lag of 5°, whereas another knee (7.1%) required a reoperation for manipulation under anesthesia and arthroscopic lysis of adhesions at 3 months' postoperatively. None of the included patients (0.0%) developed a tendon re-rupture, venous thromboembolism, delayed wound healing, surgical-site infection, neuropraxia or nerve injury, hardware irritation, patella fracture, or heterotopic ossification. Conclusions: In this study, adjustable cortical fixation was a safe and effective surgical technique for quadriceps tendon repair, with adequate restoration of quadriceps function and a low rate of adverse events at 2 years postoperatively. Level of Evidence: Level IV, therapeutic case series.

Statistical Fragility of Randomized Controlled Trials Evaluating Rehabilitation After Arthroscopic Rotator Cuff Repair.

Background: Clinical decision-making often relies on evidence-based medicine, derived from objective data with conventional and rigorous statistical tests to evaluate significance. The literature surrounding rehabilitation after rotator cuff repair (RCR) is conflicting, with no defined standard of practice. Purpose: To determine the fragility index (FI) and the fragility quotient (FQ) of randomized controlled trials (RCTs) evaluating rehabilitation protocols after RCR. Study Design: Systematic review. Methods: A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching the PubMed, Cochrane Library, and Embase databases for RCTs evaluating rehabilitation protocols after arthroscopic RCRs from 2000 to June 1, 2022. The FI was determined by manipulating the dichotomous outcome events from each article until a reversal of significance with 2 × 2 contingency tables was achieved. The FQ was determined by dividing the FI by the sample size. Results: Fourteen RCTs with 48 dichotomous outcomes were ultimately included for analysis. The mean FI for the included dichotomous outcomes was 4 (interquartile range, 3-6), suggesting that the reversal of 4 events is required to change study significance. The mean FQ was 0.048. Of the RCTs that reported data regarding loss to follow-up, most studies (58.5%) indicated that >4 patients had been lost to follow-up. Conclusion: The results of RCT studies of RCR rehabilitation protocols are moderately fragile, something clinicians should be aware of when implementing study results into practice. We recommend the inclusion of FI and FQ in addition to standard P values when reporting statistical results in future RCTs with dichotomous outcome variables on this topic.

Hormone replacement therapy does not increase thrombosis risk following THA: a national database study.

PURPOSE: Hormone replacement therapy (HRT) causes a significant increase in the risk of venous thrombosis. The risk of medical and surgery-related complications among women taking HRT following total hip arthroplasty (THA) is poorly understood, and there are currently no guidelines in place regarding venous thromboembolism prophylaxis in this patient population. The purpose of this study was to evaluate the frequency of early medical and surgery-related complications following THA among women taking HRT. METHODS: Women aged > 40 years of age who underwent primary THA were identified from a retrospective database review. A control group of non-HRT users was matched using propensity scoring to HRT users. Rates of 90-day medical complications and 1-year surgery-related complications were compared between cohorts using odds ratios. Postoperative anticoagulation regimens were also compared. RESULTS: There were 3,936 patients in the HRT cohort who were matched to 39,360 patients not taking HRT. There were no significant differences in rates of DVT (OR 0.94, p = 0.6601) or PE (OR 0.80, p = 0.4102) between cohorts. Patients on HRT were more likely to sustain a dislocation (OR 1.35, p = 0.0269) or undergo revision surgery (OR 1.23, p = 0.0105). HRT patients were more likely to be prescribed warfarin (OR 1.21, p = 0.0001) or enoxaparin (OR 1.18, p = 0.0022) and less likely to be prescribed rivaroxaban (OR 0.62, p < 0.0001) compared to controls. CONCLUSIONS: HRT was not found to be an independent risk factor for thromboembolism following THA. Further research is warranted to better delineate the ideal perioperative medical management of HRT users undergoing THA.

Cushing's Syndrome Is Associated With Early Medical- and Surgical-Related Complications Following Total Joint Arthroplasty: A National Database Study.

BACKGROUND: Cushing's syndrome (CS) is a disorder characterized by exposure to supraphysiologic levels of glucocorticoids. The purpose of this study was to evaluate the association between CS and postoperative complication rates following total joint arthroplasty (TJA). METHODS: Patients diagnosed with CS undergoing TJA for degenerative etiologies were identified from a large national database and matched 1:5 to a control cohort using propensity scoring. Propensity score matching resulted in 1,059 total hip arthroplasty (THA) patients with CS matched to 5,295 control THA patients and 1,561 total knee arthroplasty (TKA) patients with CS matched to 7,805 control TKA patients. Rates of medical complications occurring within 90 days of TJA and surgical-related complications occurring within 1 year of TJA were compared using odds ratios (ORs). RESULTS: The THA patients with CS had higher incidences of pulmonary embolism (OR 2.21, P = .0026), urinary tract infection (UTI) (OR 1.29, P = .0417), pneumonia (OR 1.58, P = .0071), sepsis (OR 1.89, P = .0134), periprosthetic joint infection (OR 1.45, P = .0109), and all-cause revision surgery (OR 1.54, P = .0036). The TKA patients with CS had significantly higher incidences of UTI (OR 1.34, P = .0044), pneumonia (OR 1.62, P = .0042), and dislocation (OR 2.43, P = .0049) and a lower incidence of manipulation under anesthesia (MUA) (OR 0.63, P = .0027). CONCLUSION: CS is associated with early medical- and surgical-related complications following TJA and a reduced incidence of MUA following TKA.

No difference in load to failure or stiffness between transosseous tunnels, suture anchors, and cortical buttons for pectoralis major tendon repair: a systematic review & meta-analysis.

PURPOSE: Surgical options for pectoralis major tendon tears include primary repair, though there is no consensus as to which constructs are biomechanically superior for repair. METHODS: A systematic review was performed by searching PubMed, the Cochrane library, and Embase using PRISMA guidelines to identify studies that analyzed the biomechanical properties of bone tunnels (BT), cortical buttons (CB) and suture anchors (SA) techniques for pectoralis major tendon repair. The search phrase implemented was 'pectoralis major tendon repair biomechanics'. Studies that did not evaluate biomechanical outcome data, evaluated partial pectoralis major tendon tears, and non-English articles were excluded. Evaluated outcomes included ultimate load to failure (N) and stiffness (N/mm). RESULTS: Six studies met inclusion criteria, including a total of 124 cadaveric specimens, for pectoralis major tendon repair comparing BT with SA and CB. Pooled analysis from four studies reporting on ultimate load to failure between BT and SA failed to reveal a difference between BT and SA (p = 0.489). Pooled analysis from two studies reporting on stiffness failed to reveal a difference in favor of BT compared to SA (p = 0.705). Pooled analysis from four studies reporting on ultimate load to failure between BT and CB failed to reveal a difference between BT and CB (p = 0.567). Pooled analysis from two studies reporting on stiffness failed to reveal a difference in favor of BT compared to CB (p = 0.701). CONCLUSIONS: There was no difference in load to failure or stiffness when using BT, CB, or SA in pectoralis major tendon repairs. This review reveals that clinical outcomes may better inform which fixation construct to implement in pectoralis major tendon repairs. LEVEL OF EVIDENCE: I.

Graft Augmentation of Rotator Cuff Repair Improves Load to Failure But Does Not Affect Stiffness or Gap Formation: A Meta-analysis of Biomechanical Studies.

PURPOSE: To examine the biomechanical properties of rotator cuff repair with graft augmentation (RCR-G) with regard to ultimate load to failure, gap displacement, and stiffness. METHODS: A systematic review was performed by searching PubMed, the Cochrane library, and Embase using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies that analyzed the biomechanical properties of RCR-G. The search string implemented used the concepts "rotator cuff" and "graft," and "biomechanical" OR "cadaver." Meta-analysis was performed to provide a quantitative comparison of the 2 techniques. Primary outcome measures were ultimate load to failure (N), gap displacement (mm), and stiffness (N/mm). RESULTS: Our initial search yielded 1,493 articles for review. Following screening for inclusion criteria, 8 studies were included in the meta-analysis, including a total of 191 cadaveric specimens (106 RCR-G, 85 RCR). The pooled analysis from 6 studies reporting on ultimate load to failure revealed a statistically significant difference in favor of RCR-G compared with RCR (P < .001). Pooled analysis from 6 studies reporting on gap displacement failed to reveal a difference between RCR-G and RCR (P = .719). Pooled analysis from 4 studies reporting on stiffness failed to reveal a difference between RCR-G and RCR (P = .842). CONCLUSIONS: Graft augmentation of RCR in vitro resulted in significantly increased ultimate load to failure, with no influence on gap formation or stiffness. CLINICAL RELEVANCE: The biomechanical advantage of RCR with graft augmentation demonstrated via increased ultimate load to failure in cadaveric studies may provide an explanation for the decreased RCR retear rates and improved patient reported outcomes reported in the clinical literature regarding graft augmentation.

Posterior Root Tears of the Lateral Meniscus Only Affect Tibiofemoral Contact Forces when the Meniscofemoral Ligament Is Involved: A Cadaveric Study.

Purpose: The objective of this study was to examine the impact of progressive radial tears in the lateral meniscal root on the lateral compartment contact forces and joint surface area through a range of motion of knee and evaluate the role of the meniscofemoral ligament (MFL) in preventing adverse tibiofemoral joint forces. Methods: Ten fresh frozen cadaveric knees were tested using 6 experimental conditions (0% lateral meniscal posterior root tear, 25% tear, 50% tear, 75% tear, 100% tear, 100% tear and resection of MFL) at five flexion angles (0°, 30°, 45°, 60°, and 90°) under 100-1,000-N axial load. Contact joint pressure and lateral compartment surface area were measured using Tekscan sensors. Statistical analysis, including descriptive, ANOVA, and post hoc Tukey analysis, was performed. Results: Progressive radial tears of the lateral meniscal root were not associated with an increase in tibiofemoral contact pressure or decrease in lateral compartment surface area. Complete lateral root tear and resection of MFL were associated with increased joint contact pressure (P < .001) at knee flexion angles of 30, 45, 60, and 90° and decreased lateral compartment surface (P < .001) at all knee flexion angles area compared to complete lateral meniscectomy alone. Conclusion: Isolated complete tears of lateral meniscus root and progressive radial tears of the lateral meniscus posterior root were not associated with any change to tibiofemoral contact forces. However, additional resection of the MFL increased contact pressure and decreased lateral compartment surface area.