The relationship of body mass index on patient reported outcomes after platelet-rich plasma versus microfragmented adipose tissue for knee osteoarthritis: A secondary analysis of a randomized controlled trial.

OBJECTIVE: Body mass index (BMI) is known to contribute to outcomes for patients with knee OA. Furthermore, BMI influences the protein expression of orthobiologic treatments like platelet-rich plasma (PRP) and microfragmented adipose tissue (MFAT). We performed a secondary analysis of the association of BMI with PROs for patients with knee OA who received either PRP or MFAT injections. METHODS: Seventy-one patients with knee OA were randomized to receive a single ultrasound-guided injection of PRP or MFAT. PRP was created from 180cc of anti-coagulated blood and processed using a double-spin, buffy-coat concentration system. MFAT was created using autologous lipoaspirate that was processed according to minimal manipulation guidelines. PROs, and osteoarthritis outcome scores (KOOS) were tracked for 12-months. RESULTS: Forty-nine patients (PRP=23, MFAT=26) completed 12-month follow-up. KOOS- Quality of life and activity of daily living subscores were inversely correlated (both p < 0.05) with BMI in the MFAT but not PRPgroup. KOOS-Pain and Sport subscores showed a trend towards inverse correlation with BMI in the MFAT group (p = 0.07 and p = 0.06, respectively), but not PRP.Conclusion: BMI was negatively associated with PROs in patients who received MFAT injections for knee OA, but not for patients receiving PRP.

Microfragmented Adipose Tissue Is Equivalent to Platelet-Rich Plasma for Knee Osteoarthritis at 12 Months Posttreatment: A Randomized Controlled Trial.

Background: Platelet-rich plasma (PRP) is an effective treatment for knee osteoarthritis (OA). Microfragmented adipose tissue (MFAT) is another orthobiologic that holds promise, but data supporting its use are limited. Previous studies showed that MFAT created using the Lipogems device was equivalent to PRP created via noncommercial laboratory-based processes. Purpose: To perform a comparison of commercially available MFAT and PRP systems for treatment of knee OA. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 71 patients with symptomatic knee OA (Kellgren-Lawrence grades 1-4) were randomized to receive a single injection of either leukocyte-rich PRP (Angel; Arthrex) or MFAT (Lipogems) under ultrasound guidance. Patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score [KOOS], visual analog scale for pain with activities of daily living [VAS pain], and Tegner activity level) were recorded at baseline and at 1, 3, 6, and 12 months after injection. The primary outcome was the KOOS-Pain subscale score at 12 months after injection. Results: Overall, 49 patients completed their 12-month follow-up (PRP group, n = 23; MFAT group, n = 26). All demographic features were similar between groups, except that more men were randomized to the PRP group and more women to the MFAT group. At 12 months posttreatment, KOOS-Pain scores improved in both groups, with no significant group difference (PRP, 78 ± 17.9 vs MFAT, 77.8 ± 19.3; P = .69). Similarly, other KOOS subscales, VAS pain scores, and Tegner scores improved at 12 months, with no differences between treatment groups. Conclusion: Both PRP and MFAT injections for knee OA resulted in improved patient-reported outcomes at 12 months posttreatment, with no differences found between treatments. Registration: NCT04351087 (ClinicalTrials.gov identifier).

Tobramycin and Vancomycin in an In Vitro Model of Anterior Cruciate Ligament Allograft Decontamination.

BACKGROUND: Approximately 100,000 anterior cruciate ligament (ACL) reconstructions (ACLRs) occur annually in the United States, and postoperative surgical-site infection is a relatively rare but devastating complication, often leading to graft failure or septic arthritis of the knee, necessitating repeat surgery. Wrapping allografts in vancomycin-soaked gauze has been adopted as a common sterilization technique in the operating room to reduce surgical-site infection; however, identifying effective alternatives to vancomycin has not been extensively pursued. HYPOTHESIS: Tobramycin would be as effective as vancomycin in reducing the concentrations of Staphylococcus epidermidis bacteria on tendon allografts. STUDY DESIGN: Controlled laboratory study. METHODS: S. epidermidis strain ATCC 12228 was inoculated onto the human cadaveric gracilis tendon. The tendons were wrapped in sterile gauze saturated with tobramycin or vancomycin at various experimental concentrations. Bacteria remaining on the tendon were dislodged, serially diluted, and plated for colony counting. Statistical analysis was performed utilizing 2-way analysis of variance testing. Results were considered statistically significant when P < .05. RESULTS: Vancomycin (P = .0001) and tobramycin (P < .0001) reduced bacterial concentration. Tobramycin was found to produce a statistically significant reduction in bacterial concentration at concentrations as low as 0.1 mg/mL (P < .0001 and P = .01 at 10 and 20 minutes), while vancomycin produced a statistically significant reduction at a concentration as low as 2.5 mg/mL (P < .0001 at both 10 and 20 minutes). CONCLUSION: This study demonstrates that tobramycin is as effective as vancomycin in bacterial concentration reduction but can achieve this reduction level at lower doses. Further studies clarifying the biomechanical and cytotoxic effects of tobramycin on tendon tissue are indicated to solidify its use as a clinical alternative to vancomycin in ACLR. CLINICAL RELEVANCE: These results will begin establishing tobramycin as an alternative to vancomycin in ACL graft decontamination. Because of relatively frequent shortages of vancomycin, establishing tobramycin as an alternative agent is a useful option for the orthopaedic surgeon.

More Is Not Merrier: Increasing Numbers of All-Inside Implants Do Not Correlate with Higher Odds of Revision Surgery.

The purpose of this study was to evaluate the relationship between the number of all-inside meniscal repair implants placed and the risk of repair failure. We hypothesized that the use of higher numbers of all-inside meniscus repair implants would be associated with increased failure risk. A retrospective chart review identified 351 patients who underwent all-inside meniscus repair between 2006 and 2013 by a sports medicine fellowship-trained orthopaedic surgeon at a single institution. Patient demographics (age, body mass index [BMI], sex) and surgical data (number of implants used, concomitant anterior cruciate ligament reconstruction [cACLR], and tear type/size/location) were recorded. Patients who received repairs in both menisci or who had follow-up < 1-year postoperatively were excluded. Repair failure was identified through chart review or patient interviews defined as a revision surgery on the index knee such as partial meniscectomy, total knee arthroplasty, meniscus transplant, or repeat repair. Logistic regression modeling was utilized to evaluate the relationship between the number of implants used and repair failure. A total of 227 all-inside meniscus repairs were included with a mean follow-up of 5.0 ± 3.0 years following surgery. Repair failure was noted in 68 knees (30.3%)-in 28.1% of knees with fewer than four implants and in 35.8% of knees with four or more implants (p = 0.31). No significant increase in failure was observed with increasing number of all-inside medial (odds ratio [OR]: 1.15; 95% confidence interval [CI]: 0.79-1.7; p = 0.46) or lateral (OR: 0.86; 95% CI: 0.47-1.57; p = 0.63) implants after controlling for patient age, BMI, cACLR, tear type, or size. Tears of the lateral meniscus located in the red-white and white-white zones had lower odds of failure (OR: 0.14; 95% CI: 0.02-0.88; p = 0.036) than tears within the red-red zone, and patients with cACLR had lower odds of repair failure (OR: 0.40; 95% CI: 0.18-0.86, p = 0.024) than those without. The number of all-inside implants placed during meniscus tear repair did not affect the likelihood of repair failure leading to reoperation after controlling for BMI, age, tear type, size, location, and cACLR. LEVEL OF EVIDENCE: III.

Management of Patellar Tendinopathy.

Patellar tendinopathy is a common pathology typically seen in athletes involved in repetitive explosive jumping and running activities. Also known as jumpers' knee, it is commonly seen in high-level basketball players. Typically, athletes continue to play with symptoms, which can be aggravated and progress to partial patellar tendon tears. When partial patellar tendon tears occur, prolonged recovery and decreased performance is commonly seen. The pathology and treatment can be frustrating for both the athlete and medical provider. Patellar tendinopathy typically does not involve inflammation but rather microinjury to the tendon fibers, which leads to mucoid degeneration, necrosis, and loss of transitional fibrocartilage. When partial tendon tears do occur, the typical location is posteromedially adjacent to the patella. Treatment involves a stepwise approach starting with nonoperative means, including activity modification, nonsteroidal anti-inflammatories, and physical therapy focused on eccentrics. Extracorporeal shock wave treatments and injections with platelet-rich plasma or bone marrow aspirate concentrate should be considered, with evolving literature to support their use. Ultrasound percutaneous tendon scrapping with a needle supplemented with the aforementioned injections is an emerging treatment option that the authors have found to be helpful, although further studies are required. Surgical intervention is considered after failure of nonoperative treatments, and typically occurs in tears greater than 50% of the tendon thickness and in tendons with increased thickness (>8.8 mm). Open or arthroscopic debridement can be considered, with no studies showing superior outcomes with either technique; however, no high-quality comparison studies exist. The authors prefer an open technique where, much like a bone-patellar tendon-bone harvest, the unhealthy proximal tendon and bone are excised with then closure of the healthy tendon with absorbable sutures. Suture anchor repair may also be used when necessary. In a recent systematic review, surgical management of patellar tendinopathy has been shown to result in improved patient-reported outcomes with return to sport at high levels.1 Treatment for the difficult and sometimes frustrating pathology of patellar tendinopathy continues to evolve, with biologic and less-invasive ultrasound-based treatments showing promise, and surgical intervention providing reliable outcomes.

Increased Body Mass Index is Associated with Worse Mid- To Long-Term Patient Outcomes after Surgical Repair of Multiligamentous Knee Injuries.

We evaluated the relationship between elevated body mass index (BMI) and mid- to long-term outcomes after surgical treatment of multiligamentous knee injury (MLKI). Records identified patients treated surgically for MLKI at a single institution. Inclusion criteria: minimum 2 years since surgery, complete demographics, surgical data, sustained injuries to two or more ligaments in one or both knees, and available for follow-up. Patients were contacted to complete patient-reported outcomes assessments and were classified according to mechanism of injury. Multivariate logistic regression analysis was used to predict the impact of BMI on outcome scores. A total of 77 patients (72.7% male) were included with a mean age at the time of injury of 29.4 ± 11.0 years and a mean BMI of 30.5 ± 9.4 kg/m2. The mean length of follow-up was 7.4 years. For each 10 kg/m2 increase in BMI, there is a 0.9-point decrease in Tegner activity scale (p = 0.001), a 5-point decrease in Knee Injury and Osteoarthritis Outcome Score (KOOS)-pain (p = 0.007), a 5-point decrease in KOOS-ADL (p = 0.003), a 10-point decrease in KOOS-QOL (p = 0.002), and an 11-point decrease in KOOS-Sport (p = 0.002). There were no significant correlations with BMI and Pain Catastrophizing Scale or Patient Health Questionnaire scores. Increasing BMI has a negative linear relationship with mid- to long-term clinical outcomes including pain, ability to perform activities of daily living, quality of life, and ability to perform more demanding physical activity after MLKI. BMI does not appear to have a significant relationship with knee swelling and mechanical symptoms or patients' mental health.

Predictors of Return to Activity at 2 Years After Anterior Cruciate Ligament Reconstruction Among Patients With High Preinjury Marx Activity Scores: A MOON Prospective Cohort Study.

BACKGROUND: Predictors of return to activity after anterior cruciate ligament reconstruction (ACLR) among patients with relatively high preinjury activity levels remain poorly understood. PURPOSE/HYPOTHESIS: The purpose of this study was to identify predictors of return to preinjury levels of activity after ACLR, defined as achieving a Marx activity score within 2 points of the preinjury value, among patients with Marx activity scores of 12 to 16 who had been prospectively enrolled in the Multicenter Orthopaedic Outcomes Network (MOON) cohort. We hypothesized that age, sex, preinjury activity level, meniscal injuries and/or procedures, and concurrent articular cartilage injuries would predict return to preinjury activity levels at 2 years after ACLR. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: All unilateral ACLR procedures from 2002 to 2008 performed in patients enrolled in the MOON, with preinjury Marx activity scores ranging from 12 to 16, were evaluated with a specific focus on return to preinjury activity levels at 2 years postoperatively. Return to activity was defined as a Marx activity score within 2 points of the preinjury value. The proportion of patients able to return to preinjury activity levels was calculated, and multivariable modeling was performed to identify risk factors for patients' inability to return to preinjury activity levels. RESULTS: A total of 1188 patients were included in the final analysis. The median preinjury Marx activity score was 16 (interquartile range, 12-16). Overall, 466 patients (39.2%) were able to return to preinjury levels of activity, and 722 patients (60.8%) were not able to return to preinjury levels of activity. Female sex, smoking at the time of ACLR, fewer years of education, lower 36-Item Short Form Health Survey Mental Component Summary scores, and higher preinjury Marx activity scores were predictive of patients' inability to return to preinjury activity levels. Graft type, revision ACLR, the presence of medial and/or lateral meniscal injuries, a history of meniscal surgery, the presence of articular cartilage injuries, a history of articular cartilage treatment, and the presence of high-grade knee laxity were not predictive of a patient's ability to return to preinjury activity level. CONCLUSION: At 2 years after ACLR, most patients with high preinjury Marx activity scores did not return to their preinjury level of activity. The higher the preinjury Marx activity score that a patient reported at the time of enrollment, the less likely he/she was able to return to preinjury activity level. Smoking and lower mental health at the time of ACLR were the only modifiable risk factors in this cohort that predicted an inability to return to preinjury activity levels. Continued effort and investigation are required to maximize functional recovery after ACLR in patients with high preinjury levels of activity.

Elevated Posterior Tibial Slope Is Associated With Anterior Cruciate Ligament Reconstruction Failures: A Systematic Review and Meta-analysis.

PURPOSE: To evaluate the association of posterior tibial slope (PTS) with anterior cruciate ligament (ACL) reinjury following primary ACL reconstruction. METHODS: PubMed, Scopus, Embase, and CINAHL databases were searched from inception through March 1, 2021, to retrieve relevant studies. Comparative studies reporting PTS measurements in a cohort of patients experiencing ACL graft failure versus patients with intact primary ACL reconstruction or studies comparing patients undergoing revision ACL reconstruction versus primary ACL reconstruction were included for analysis. A random-effects model was used to calculate the overall standardized mean difference (SMD) between groups. The following inclusion criteria were used: English language; full text available; Level I, II, or III evidence; studies in humans; and skeletally mature patients. RESULTS: After we systematically screened 1,912 studies, 15 studies met the inclusion/exclusion criteria. Radiographic measurements were used in 6 studies reporting medial PTS in 411 ACL failures versus 2808 controls. Patients with ACL failure had significantly greater medial PTS compared with controls (SMD 0.50; 95% confidence interval [CI] 0.23-0.77; P < .001). Magnetic resonance imaging (MRI) was used in 9 studies reporting lateral PTS measurements in 641 patients with a failed ACL reconstruction compared with 705 controls. Seven of the MRI studies also measured medial PTS in 552 failures versus 641 controls. Patients with ACL failure had significantly greater lateral PTS on MRI (SMD 0.58; 95% CI 0.13-1.03; P = .012) and medial PTS on MRI (SMD 0.59; 95% CI 0.23-0.96; P = .001) compared with controls. CONCLUSIONS: The present meta-analysis demonstrated that patients with elevated PTS on radiographs and MRI are at increased risk for ACL graft failure after primary ACL reconstruction. LEVEL OF EVIDENCE: Level III, meta-analysis of Level III studies.

Biologic Augmentation during Meniscal Repair.

We reviewed the literature regarding utility of biologic augmentation in meniscal repair. We hypothesized that the addition of biologic augmentation during meniscal repair improves postoperative knee function and reduces risk of repair failure. PubMed and Embase databases were systematically searched. Included studies were clinical studies in humans, published in English, and reported use of biologic augmentation techniques in addition to meniscal repair (including platelet-rich plasma [PRP], fibrin clot, bone marrow stimulation, meniscal wrapping, and bioscaffolds) for treatment of knee meniscal tears. Outcome measures included repair failure, repeat knee arthroscopic surgery, and magnetic resonance imaging), visual analog scale for pain, the International Knee Documentation Committee questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index Lysholm's Knee Scoring Scale, and the Knee Injury and Osteoarthritis Outcome Score. Study quality was assessed using the modified Coleman methodology score. Nineteen studies reported repair of 1,092 menisci including six studies that investigated fibrin clot augmentation, five studies that investigated PRP augmentation, three studies that investigated bone marrow stimulation augmentation, two studies that used meniscal wrapping augmentation, and three studies that used other techniques. The level of evidence ranged from I to IV and mean modified Coleman methodology score was 43 (range: 17-69), with higher scores noted in studies completed in recent years. PRP and bone marrow stimulation augmentation appear to decrease risk of failure in patients undergoing isolated meniscal repair but do not improve knee symptom scores. Fibrin clot and trephination augmentation techniques do not have sufficient evidence to support decreased failure risk at this time. Meniscal wrapping augmentation and scaffold implantation augmentation appear to be an attractive option to meniscectomy in complicated tears that are not candidates for repair alone, but further confirmatory studies are needed to support initial data. Evidence supporting augmentation of meniscal repair is limited at this time but suggests that the highest likelihood for effectiveness of augmentation is in the settings of isolated meniscal repair or meniscal repairs that would normally not be amenable to repair.

Larger Prior Tibial Tunnel Size Is Associated with Increased Failure Risk following Revision Anterior Cruciate Ligament Reconstruction.

We hypothesize that larger prior tunnel size is associated with an increased risk of failure of single-stage revision anterior cruciate ligament reconstruction (ACLR) as defined by the performance of a re-revision (third) ACLR on the index knee. Retrospective review identified 244 patients who underwent single-stage revision ACLR at a single center with available preoperative radiographs. Patient and surgical factors were extracted by chart review. The maximum diameter of the tibial tunnel was measured on lateral radiographs and the maximum diameter of the femoral tunnel was measured on anteroposterior radiographs. Record review and follow-up phone calls were used to identify failure of the revision surgery as defined by re-revision ACLR on the index knee. One hundred and seventy-one patients (70%) were reviewed with a mean of 3.9 years follow-up. Overall, 23 patients (13.4%) underwent re-revision surgery. Mean tibial tunnel size was 12.6 ± 2.8 mm (range: 5.7-26.9 mm) and mean femoral tunnel size was 11.7 ± 2.8 mm (range: 6.0-23.0 mm). Re-revision risk increased with tibial tunnel size. Tibial tunnels 11 mm and under had a re-revision risk of 4.2%, while tunnels > 11 mm had a risk of 17.1% (relative risk: 4.1, p = 0.025). No significant association between femoral tunnel size and re-revision risk was noted. Patients with prior tibial tunnels > 11mm in diameter at revision surgery had significantly increased risk of re-revision ACLR. Further studies are needed to explore the relationship between prior tunnel size and outcomes of revision ACLR.

Influence of Staphylococcus epidermidis biofilm on the mechanical strength of soft tissue allograft.

We sought to determine the impact of bacterial inoculation and length of exposure on the mechanical integrity of soft tissue tendon grafts. Cultures of Staphylococcus epidermidis were inoculated on human tibialis posterior cadaveric tendon to grow biofilms. A low inoculum in 10% growth medium was incubated for 30 min to replicate conditions of clinical infection. Growth conditions assessed included inoculum concentrations of 100, 1000, 10,000 colony-forming units (CFUs). Tests using the MTS Bionix system were performed to assess the influence of bacterial biofilms on tendon strength. Load-to-failure testing was performed on the tendons, and the ultimate tensile strength was obtained from the maximal force and the cross-sectional area. Displacements of tendon origin to maximal displacement were normalized to tendon length to obtain strain values. Tendon force-displacement and stress-strain relationships were calculated, and Young's modulus was determined. Elastic modulus and ultimate tensile strength decreased with increasing bioburden. Young's modulus was greater in uninoculated controls compared to tendons inoculated at 10,000 CFU (p = 0.0011) but unaffected by bacterial concentrations of 100 and 1000 CFU (p = 0.054, p = 0.078). Increasing bioburden was associated with decreased peak load to failure (p = 0.043) but was most significant compared to the control under the 10,000 and 1000 CFU growth conditions (p = 0.0005, p = 0.049). The presence of S. epidermidis increased elasticity and decreased ultimate tensile stress of human cadaveric tendons, with increasing effect noted with increasing bioburden.

Association of Elevated Posterior Tibial Slope With Revision Anterior Cruciate Ligament Graft Failure in a Matched Cohort Analysis.

BACKGROUND: Elevated posterior tibial slope (PTS) has been identified as an important risk factor in anterior cruciate ligament (ACL) injuries and ACL graft failures. The cutoff value to recommend treatment with slope-reducing osteotomy remains unclear and is based on expert opinion and small case series. PURPOSE: (1) To determine whether there is a difference in PTS shown on lateral knee radiographs and magnetic resonance imaging (MRI) scans in a group of patients who experienced revision ACL graft failure versus a control group of patients who underwent successful revision ACL reconstruction, (2) to identify cutoff values of PTS measurements that predict risk of revision ACL graft failure, and (3) to examine whether there is a correlation between radiographic and MRI measurements of PTS. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 38 patients who experienced revision ACL graft failure were identified from a revision ACL database. These patients were matched 1:1 by age, sex, and graft type to a group of 38 control patients who underwent revision ACL reconstruction with no evidence of graft failure at a minimum 2 years of follow-up. Medial and lateral PTS were measured by lateral knee radiographs and MRI scans of the affected limb. Demographics, surgical characteristics, and PTS were compared between the groups. The optimal cutoff values of medial and lateral PTS per radiographs and MRI scans for predicting increased risk of revision ACL graft failure were determined by receiver operating characteristic curves. Conditional multivariable logistic regression was used to assess the relative contribution of PTS cutoff values as a predictor of revision graft failure. RESULTS: The mean PTS values in the failure group were significantly higher than those in the control group on radiographs (medial, 13.2°± 2.9° vs 10.3°± 2.9°; P < .001; lateral, 12.9°± 3.0° vs 9.8°± 2.8°; P < .001) and MRI scans (medial, 7.2°± 3.1° vs 4.8°± 2.9°; P < .001; lateral, 8.4 ± 3.1° vs 5.9 ± 3.0°; P < .001). A radiographic medial PTS ≥14° had the highest increased risk of revision ACL graft failure with sensitivity equal to 50% and specificity to 92.1% (odds ratio, 18.71; 95% CI, 2.0-174.9; P = .01). CONCLUSION: Elevated PTS was a significant risk factor for revision ACL graft failure. Patients with radiographic medial PTS ≥14° had 18.7-times increased risk of revision ACL failure.

Smaller Iatrogenic Defects Created by Inside-Out Compared With All-Inside Meniscus Repair Devices in Human Cadaveric Model.

PURPOSE: (1) To investigate the pattern and diameter of the iatrogenic defect that meniscal repair devices impose on meniscal tissue and (2) to determine whether repair-induced defect patterns or diameters differ across devices. METHODS: Sixty-one fresh frozen human cadaveric menisci were used (n = 9; eliminated). All-inside devices (n = 9) included ULTRA FAST-FIX, FAST-FIX 360, Depuy Mitek 0° and 12° TRUESPAN, ConMed Sequent, Zimmer Biomet JuggerStitch, Stryker IvyAIR, Arthrex FiberStitch and Meniscal Cinch II. Inside-out needles (n = 4) included ConMed HiFi, Depuy Mitek ORTHOCORD, Arthrex-2-0 FiberWire, and Stryker SharpShooter. Following India Ink staining, implant devices were inserted into cadaveric menisci. Samples were fixed in formalin solution and imaged with a high-resolution camera. Defects were classified by qualitative evaluation. Defect and needle diameter were quantified with software assistance. Statistical analysis was performed using analysis of variance testing. RESULTS: We analyzed 644 iatrogenic defects with mean defect diameter of 1.96 mm (standard deviation 0.86). For all-inside devices, defect patterns (n = 436) were 15.6% linear, 38.1% semilunar, 46.3% stellate, while inside-out devices (n = 208) were 95.7% stellate, 4.3% linear, and 0.0% semilunar. All-inside devices had mean defect diameter of 2.46 mm, while inside-out meniscus needles had mean 0.90 mm defect diameter (P < .001). FasT-FIX 360, ULTRA-FAST-FIX, and Arthrex Meniscal Cinch II induced smaller diameter defects than other all-inside devices (F = 20.2, P < .05). Strong positive correlation was found comparing outer needle diameter and mean defect diameters across all devices (R2 = 0.9447). CONCLUSIONS: Needles utilized in meniscal implant systems produce the following basic defect patterns: stellate (62.3%), semilunar (25.8%), and linear (11.9%). A strong positive correlation was found between mean defect size and outer needle diameter across all devices. Inside-out double-armed flexible needles produced significantly smaller defects than all-inside devices. Of the all-inside devices, ULTRA FAST-FIX, FAST-FIX 360, and Arthrex Meniscal Cinch II produced smaller defects on average. CLINICAL RELEVANCE: While the true clinical impact of these findings cannot be drawn from the present study, this investigation provides necessary context to better understand reported similarities and differences in healing rates and outcomes between inside-out and all-inside repair techniques.

Arthroscopic Bone Graft Technique for Two-Stage Revision Anterior Cruciate Ligament Reconstruction.

Revision anterior cruciate ligament reconstruction is an increasingly common procedure, with 2-stage surgery often required to address large bone defects and malpositioned tunnels. The arthroscopic bone grafting technique described herein uses morselized allograft bone to provide reproducible fill of asymmetrical bone defects without autograft harvest or additional loss of native bone. The second stage of the anterior cruciate ligament reconstruction can typically proceed 6 months following bone grafting.

Accelerated rehabilitation program following medial patellofemoral ligament reconstruction does not increase risk of recurrent instability.

BACKGROUND: Rehabilitation protocols following medial patellofemoral ligament (MPFL) reconstruction were historically restrictive, with patients often immobilized and/or given weightbearing restrictions. However, more recently published protocols have been more aggressive. We compared patient-reported outcomes and recurrent dislocation risk between patients treated with a restrictive rehabilitation program (early post-operative bracing and weightbearing restrictions) and an accelerated rehabilitation protocol (no post-operative bracing or weightbearing restrictions) following MPFL reconstruction. METHODS: Patients who underwent isolated MPFL reconstruction at an academic center between 2008 and 2016 were identified. Patient demographics, anatomical measurements, surgical details, and outcomes were collected. During this period, the rehabilitation protocol at the center transitioned from a restrictive to an accelerated rehabilitation protocol. Failure risk and patient-reported outcomes were compared based on rehabilitation protocol. RESULTS: Of the163 isolated MPFL reconstructions performed during the study period, 123 (75%) were available for minimum one-year follow up at a mean of 4.0 years post-operative. Overall, 53 knees (43%) underwent the accelerated rehabilitation protocol and the remaining 70 knees (57%) underwent the restrictive protocol. There were 3 recurrent dislocations during the study period (2.4%), all of which occurred in the restrictive rehabilitation group. Multiple linear regression demonstrated that being in the accelerated rehabilitation group was not associated with poorer Knee injury and Osteoarthritis Outcome Score (KOOS) subscales controlling for age, sex, body mass index, Caton-Deschamps Index, tibial tubercle-trochlear groove distance, sulcus angle, MPFL graft choice, and length of follow-up. CONCLUSION: An accelerated rehabilitation protocol without immobilization or weightbearing restrictions does not increase risk of recurrent patellar dislocation or poorer patient-reported outcome following isolated MPFL reconstruction.

Platelet-Rich Plasma Versus Microfragmented Adipose Tissue for Knee Osteoarthritis: A Randomized Controlled Trial.

Background: Platelet-rich plasma (PRP) has been established as safe and effective for knee osteoarthritis (OA). Another orthobiologic therapy, microfragmented adipose tissue (MFAT), has gained attention because of its heterogeneous cell population (including mesenchymal stem cells). However, prospective comparative data on MFAT are lacking. Because of the safety, efficacy, and simplicity of PRP, new therapeutics such as MFAT should be compared directly with PRP. Purpose: To compare patient-reported outcomes of a single injection of PRP versus MFAT for knee OA. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 58 patients with symptomatic knee OA (Kellgren-Lawrence grades 1-4) were randomized to receive a single injection of either leukocyte-rich PRP or MFAT under ultrasound guidance. PRP was created by processing 156 mL of whole blood. MFAT was created by harvesting 30 mL of adipose tissue via standard lipoaspiration. Scores for the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales and visual analog scale for pain with Activities of Daily Living (VAS-ADL) were recorded at baseline and at 1, 3, and 6 months after the injection. The primary outcome was the KOOS-Pain subscore at 6 months after the injection. Results: The PRP group (n = 30) had a mean volume of 5.12 ± 1.12 mL injected. This consisted of a mean platelet count of 2673.72 ± 1139.04 × 103/µL and mean leukocyte count of 25.36 ± 13.27 × 103/µL (67.81% lymphocytes, 18.66% monocytes, and 12.33% neutrophils). The MFAT group (n = 28) had a mean volume of 7.92 ± 3.87 mL injected. The mean total nucleated cell count was 3.56 ± 4.62 million/mL. In both groups, KOOS subscale and VAS-ADL scores improved from baseline, and there was no significant difference between the PRP and MFAT groups in the final KOOS-Pain subscore (80.38 ± 16.07 vs 81.61 ± 16.37, respectively; P = .67) or any other outcome score. Conclusion: A single injection of either PRP or MFAT resulted in a clinically meaningful improvement for patients with knee OA at 6 months, with no difference between treatment groups. Registration: NCT04351087 (ClinicalTrials.gov identifier).

Influence of Patellofemoral Anatomy on Outcomes of Isolated Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability.

Background: Patella alta and elevated tibial tubercle-trochlear groove (TT-TG) distance can predispose patients to lateral patellar dislocations and recurrent instability. Their influence on patient-reported outcomes (PROs) after medial patellofemoral ligament (MPFL) reconstruction is less clear. Hypothesis: We hypothesized that neither moderately increased TT-TG distance nor patella alta would negatively affect PROs after isolated MPFL reconstruction in patients with relatively normal patellar tracking (no large J-sign). Study Design: Cohort study; Level of evidence, 3. Methods: We identified patients who underwent isolated MPFL reconstruction at a single institution between 2008 and 2016. The decision to perform an isolated MPFL reconstruction was at the discretion of the operating surgeon but was not performed in the setting of a large J-sign. Patient characteristics and surgical details were collected, and patients completed the Norwich Patellar Instability Score, Knee injury and Osteoarthritis Outcome Score, and Marx activity score. Patellar height (Caton-Deschamps Index [CDI]) was assessed on preoperative lateral radiographs, and TT-TG distance was measured on preoperative axial magnetic resonance imaging (MRI) scans. Patients were grouped based on CDI and TT-TG distance, and outcomes were compared. Linear regression modeling was performed to determine whether patella alta or elevated TT-TG distance was associated with poorer PRO scores. Results: Of 165 knees in 152 patients who underwent isolated MPFL reconstruction, 115 patients (125 knees; 76%) with minimum 1-year follow-up were contacted at a mean of 5.2 years after surgery. Recurrent dislocation occurred in 5 of 125 knees (4%). Preoperative radiographs were available in 111 knees (89%), and preoperative MRI scans were available in 89 knees (71%). Mean CDI was 1.13, and 35% had a CDI ≥1.20. Mean TT-TG distance was 17.5 mm, and 26% had a TT-TG distance >20 mm. After adjusting for patient age, sex, body mass index, and graft choice, we observed that neither patella alta nor elevated TT-TG distance were associated with poorer PROs. Conclusion: Isolated MPFL reconstruction in the setting of moderately elevated TT-TG distance or patella alta was not associated with worse PROs in this cohort with relatively normal patellar tracking (no large J-sign).

Treatment of Chronic Proximal Hamstring Tendinopathy with Surgical Debridement and Suture Anchor Repair.

We evaluated outcomes following surgical debridement and suture anchor repair of chronic proximal hamstring tendinopathy without sciatic nerve decompression. Chart review identified eight patients (one bilateral) who met study requirements. All eight patients were available for follow-up at a mean of 6.7 years and none underwent re-operation on the index hip during the follow-up period. Seven patients completed patient-reported outcome scores. The mean LEFS score was 81.1, and the mean SANE score was 74.9. The mean Marx activity score was 2.8, and the mean Custom Marx score was 23.3. Pain relief was excellent. The mean numeric pain score at rest was 0.6, while the mean numeric pain score with activity was 4.0. Treatment of chronic, recalcitrant proximal hamstring tendinopathy with surgical debridement and suture anchor repair without exploration of the sciatic nerve results in excellent pain relief, good function, and low re-operation risk. (Journal of Surgical Orthopaedic Advances 31(1):061-064, 2022).

Several Techniques Exist With Favorable Biomechanical Outcomes in Radial Meniscus Tear Repair-A Systematic Review.

PURPOSE: To compare biomechanical properties of various radial tear repair techniques in the medial and lateral menisci. METHODS: A search was performed for key words regarding mechanical properties of repair of radial meniscal tears in PubMed, Embase, CINAHL, Scopus, and Cochrane databases, yielding 1791 articles. Articles were screened using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines against inclusion criteria and underwent Methodological Index for Non-Randomized Studies (MINORS) methodologic quality assessment. Repair constructs evaluated were classified based on repair technique, use of a transtibial augmentation, and the number, orientation, and pattern of stitches. Results published across different studies were compared but not subjected to meta-analysis due to variability in testing procedures and heterogeneity of repair methods. RESULTS: We identified 20 studies that performed mechanical testing on 21 different radial meniscal tear repair techniques. The greatest reported mean load-to-failure (LtF) were the transtibial 2-tunnel + 4 horizontal inside-out sutures (191.2 N ± 17.3, cadaver) and all-inside double vertical repair (146.3 N ± 36.2, porcine). The transtibial technique improved LtF and displacement of an inside-out (IO) horizontal repair. All-inside vertical repairs demonstrated greater LtF, stiffness, and displacement compared with IO horizontal repairs in 2 studies. Compared with IO double horizontal repairs, all-inside double vertical or IO double horizontal repairs with reinforcing stitches parallel to the tear exhibited greater LtF in 3 studies and stiffness in 2 studies. Two studies reported that parallel reinforcing stitches significantly reduced suture tear-through compared with similar, nonreinforced repairs. Mean MINORS score for all studies analyzed was 19.88 ± 1.47 points. CONCLUSIONS: A systematic review demonstrated that there may be alternatives to traditional IO horizontal repairs for radial meniscus tears. Less-invasive all-inside vertical techniques reinforced with suture parallel to the tear instead of standard IO horizontal sutures may improve strength of repair. In addition, transtibial 2-tunnel augmentation may also increase strength of radial meniscus tear repairs. CLINICAL RELEVANCE: There may be alternatives to IO horizontal repairs for radial meniscus tears.

Design Features and Rationale of the BEAR-MOON (Bridge-Enhanced ACL Restoration Multicenter Orthopaedic Outcomes Network) Randomized Clinical Trial.

BACKGROUND: BEAR (bridge-enhanced anterior cruciate ligament [ACL] restoration), a paradigm-shifting technology to heal midsubstance ACL tears, has been demonstrated to be effective in a single-center 2:1 randomized controlled trial (RCT) versus hamstring ACL reconstruction. Widespread dissemination of BEAR into clinical practice should also be informed by a multicenter RCT to demonstrate exportability and compare efficacy with bone--patellar tendon-bone (BPTB) ACL reconstruction, another clinically standard treatment. PURPOSE: To present the design and initial preparation of a multicenter RCT of BEAR versus BPTB ACL reconstruction (the BEAR: Multicenter Orthopaedic Outcomes Network [BEAR-MOON] trial). Design and analytic issues in planning the complex BEAR-MOON trial, involving the US National Institute of Arthritis and Musculoskeletal and Skin Diseases, the US Food and Drug Administration, the BEAR implant manufacturer, a data and safety monitoring board, and institutional review boards, can usefully inform both clinicians on the trial's strengths and limitations and future investigators on planning of complex orthopaedic studies. STUDY DESIGN: Clinical trial. METHODS: We describe the distinctive clinical, methodological, and operational challenges of comparing the innovative BEAR procedure with the well-established BPTB operation, and we outline the clinical motivation, experimental setting, study design, surgical challenges, rehabilitation, outcome measures, and planned analysis of the BEAR-MOON trial. RESULTS: BEAR-MOON is a 6-center, 12-surgeon, 200-patient randomized, partially blinded, noninferiority RCT comparing BEAR with BPTB ACL reconstruction for treating first-time midsubstance ACL tears. Noninferiority of BEAR relative to BPTB will be claimed if the total score on the International Knee Documentation Committee (IKDC) subjective knee evaluation form and the knee arthrometer 30-lb (13.61-kg) side-to-side laxity difference are both within respective margins of 16 points for the IKDC and 2.5 mm for knee laxity. CONCLUSION: Major issues include patient selection, need for intraoperative randomization and treatment-specific postoperative physical therapy regimens (because of fundamental differences in surgical technique, initial stability construct, and healing), and choice of noninferiority margins for short-term efficacy outcomes of a novel intervention with evident short-term advantages and theoretical, but unverified, long-term benefits on other dimensions.