Analysis of Changing Practice Trends in Anterior Cruciate Ligament Reconstruction: A Multicenter, Single-Institution Database Analysis.

PURPOSE: To identify trends in anterior cruciate ligament reconstruction (ACLR), including graft choice, femoral tunnel drilling techniques, and augmentation techniques, and to assess how various surgeon factors impact these trends. METHODS: A retrospective review of primary ACLRs performed between 2014 and 2022 was completed using a multicenter institutional database. Patient demographic characteristics, graft type, femoral drilling technique, use of extra-articular tenodesis, and use of suture augmentation were recorded from the medical record. Surgeon fellowship training (sports trained vs non-sports trained), experience (high [minimum of 15 years in practice] vs low), and volume (high [minimum of 15 ACLRs/year] vs low) were used to stratify technique utilization. The z test for proportions was used to compare categorical variables. Pearson correlation analyses identified trends and assessed statistical significance, defined as P < .05. RESULTS: Our cohort consisted of 2,032 ACLRs performed in 2,006 patients. The average patient age was 28.3 ± 11.6 years, with more procedures performed in male patients (67.3%). The average length of surgeon experience was 19.7 ± 11.4 years, with an average annual procedural volume of 4.0 ± 5.4 ACLRs. Most surgeons were sports trained (n = 55, 64.7%), high experience (n = 44, 57.1%), and low volume (n = 80, 94.1%). There was an increasing annual proportion of ACLRs performed by sports-trained surgeons (R = 0.748, P = .020) and low-experience surgeons (R = 0.940, P < .001). Autograft reconstructions were most often performed by sports-trained (71.2%), low-experience (66.1%), and high-volume (76.9%) surgeons. There was an increasing proportion of autograft ACLRs that used quadriceps tendon among sports-trained (R = 0.739, P = .023), high-experience (R = 0.768, P = .016), and low-volume (R = 0.785, P = .012) surgeons. Independent drilling techniques were used in an increasing proportion of ACLRs performed by non-sports-trained (R = 0.860, P = .003) and high-volume (R = 0.864, P = .003) surgeons. Augmentation of ACLR with concomitant suture augmentation (n = 24, 1.2%) or extra-articular tenodesis (n = 6, 0.3%) was rarely performed. CONCLUSIONS: In our multicenter institution, the quadriceps tendon autograft has been increasingly used in ACLR by sports-trained, low-volume, and high-experience surgeons. Independent drilling techniques have been increasingly used by non-sports-trained and high-volume surgeons. CLINICAL RELEVANCE: Surgeons must stay current with the literature that affects their procedures to ensure that evidence-based medicine is being practiced.

Patient Demographic Factors Are Not Associated With Mesenchymal Stromal Cell Concentration in Bone Marrow Aspirate Concentrate.

Purpose: To describe the capacity for concentration of a single processing machine for bone marrow aspirate concentrate (BMAC) production and investigate the effects of demographic factors on the number of mesenchymal stromal cells (MSCs) in BMAC. Methods: Patients enrolled in our institution's randomized control trials involving BMAC who had complete BMAC flow cytometry data were included. Multipotent MSC phenotype, defined as cell-surface coexpression of specific-identifying antigens (≥95% positive) and the absence of hematopoietic lineage markers (≤2% positive), was determined for both patient bone marrow aspirate (BMA) and BMAC samples. The ratio of cells in BMA:BMAC samples was calculated and Spearman correlations (i.e., body mass index [BMI]) and Kruskall-Wallis (i.e., age: <40, 40-60, >60 years) or Mann-Whitney (i.e., sex) tests were used to determine the relationship of cell concentration to demographic factors. Results: Eighty patients were included in analysis (49% male, mean age: 49.9 ± 12.2 years). Mean concentration of BMA and BMAC was 2,048.13 ± 2,004.14 MSCs/mL and 5,618.87 ± 7,568.54 MSC/mL, respectively, with a mean BMAC:BMA ratio of 4.35 ± 2.09. A significantly greater MSC concentration was observed in the BMAC samples when compared with BMA (P = .005). No patient demographic factors (age, sex, height, weight, BMI) were found to predict MSC concentration in the BMAC samples (P ≥ .01). Conclusions: Demographic factors, including age, sex, and BMI do not impact the final concentration of MSCs in BMAC when using a single harvest technique (anterior iliac crest) and a single processing system. Clinical Relevance: As the role of BMAC therapy expands in clinical application, it becomes increasingly important to understand the determinants of BMAC composition and how it is affected by different harvesting techniques, concentrating processes, and patient demographics.

Prospective Randomized Trial of Biologic Augmentation With Bone Marrow Aspirate Concentrate in Patients Undergoing Arthroscopic Rotator Cuff Repair.

BACKGROUND: Although initial studies have demonstrated that concentrated bone marrow aspirate (cBMA) injections promote rotator cuff repair (RCR) healing, there are no randomized prospective studies investigating clinical efficacy. HYPOTHESIS/PURPOSE: To compare outcomes after arthroscopic RCR (aRCR) with and without cBMA augmentation. It was hypothesized that cBMA augmentation would result in statistically significant improvements in clinical outcomes and rotator cuff structural integrity. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Patients indicated for aRCR of isolated 1- to 3-cm supraspinatus tendon tears were randomized to receive adjunctive cBMA injection or sham incision. Bone marrow was aspirated from the iliac crest, concentrated using a commercially available system, and injected at the aRCR site after repair. Patients were assessed preoperatively and serially until 2 years postoperatively via the following functional indices: American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test, 12-Item Short Form Health Survey, and Veterans RAND 12-Item Health Survey. Magnetic resonance imaging (MRI) was performed at 1 year to assess rotator cuff structural integrity according to Sugaya classification. Treatment failure was defined as decreased 1- or 2-year ASES or SANE scores as compared with preoperative baseline, the need for revision RCR, or conversion to total shoulder arthroplasty. RESULTS: An overall 91 patients were enrolled (control, n = 45; cBMA, n = 46): 82 (90%) completed 2-year clinical follow-up and 75 (82%) completed 1-year MRI. Functional indices significantly improved in both groups by 6 months and were sustained at 1 and 2 years (all P < .05). The control group showed significantly greater evidence of rotator cuff retear according to Sugaya classification on 1-year MRI (57% vs 18%; P < .001). Treatment failed for 7 patients in each group (control, 16%; cBMA, 15%). CONCLUSION: cBMA-augmented aRCR of isolated supraspinatus tendon tears may result in a structurally superior repair but largely fails to significantly improve treatment failure rates and patient-reported clinical outcomes when compared with aRCR alone. Additional study is warranted to investigate the long-term benefits of improved repair quality on clinical outcomes and repair failure rates. REGISTRATION: NCT02484950 (ClinicalTrials.gov identifier).

Microdrilling Demonstrates Superior Patient-Reported Outcomes and Lower Revision Rates Than Traditional Microfracture: A Matched Cohort Analysis.

PURPOSE: The purpose of this study was to compare patient-reported outcomes and revision rates between the standard microfracture awl versus the microdrilling technique. METHODS: Microfracture patients were queried from a single-institution database between 2001 and 2016. Patient-reported outcome measure data were collected at preoperative and 6- and 12-month time points, inclusive of the International Knee Documentation Committee (IKDC) score, Short Form 12 (SF12) Physical Component Score (PCS) and Mental Component Score, and all Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales. A matching algorithm based on previous procedures, lesion size, and demographic factors created 2 technique-based cohorts. Outcomes including revision rates and both statistically and clinically significant differences (i.e., the minimally clinically important difference [MCID]) between awl and microdrill cohorts were compared using univariate statistics. RESULTS: A total of 68 patients (aged 32.0 ± 13.1 years, 48.5% female, body mass index 26.7 ± 5.3 kg/m2), with 34 patients in each group, were included after the match. At 6 months, the microdrilling group demonstrated significantly greater levels of improvement than the awl group on the IKDC, SF12 PCS, and KOOS Pain, Symptom, Sport, and Quality of Life (P < .04), although differences at 1 year were only maintained on the SF12 PCS instrument (P < .001). With respect to MCID achievement, the microdrilling group demonstrated greater achievement rates at 6 months on the IKDC, KOOS Pain, and KOOS Sport (P < .04). The awl group demonstrated a higher rate of revision surgery (P = .02) within 3 years of follow-up and a greater likelihood to require multiple subsequent procedures (41.1% vs 17.6%, P = .03). CONCLUSIONS: Microdrilling demonstrated superior outcomes relative to traditional microfracture awl techniques with respect to patient-reported outcomes at 6 months and revision rates within 3 years of follow-up. In addition, clinically meaningful differences were evident at 6 months in the microdrilling group. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Time to closure of orthopaedic surgical incisions: a novel skin closure device versus conventional sutures.

OBJECTIVE: New technologies are being developed to optimise healing of surgical incisions. BandGrip (US) is a micro-anchor skin closure device that replaces the need for subcuticular suturing and further dressing. The purpose of this study is to perform a matched cohort analysis comparing time to closure of surgical incisions between sutures and the novel skin closure device. METHOD: Patients undergoing orthopaedic surgery in 2019 underwent skin closure with either conventional sutures or the novel skin closure device. Patients were divided into three groups according to their procedural incisions: anterior cruciate ligament reconstruction (ACLR); simple arthroscopy; and general incisions. Patients who underwent closure of their surgical incision with the novel skin closure device were matched with patients undergoing superficial closure with sutures. Statistical analysis was performed to compare time to closure per centimetre of skin incision between the groups. RESULTS: A total of 86 patients were included in the study. Overall mean time to closure using the novel skin closure device was less than with sutures (8.6 seconds/cm versus 42.8 seconds/cm, respectively, p<0.001). Mean time to closure for ACLR incisions was 3.7 seconds/cm using the novel skin closure device and 35.5 seconds/cm using sutures (p<0.001). Mean time to closure for simple arthroscopy portals was 19 seconds/cm using the novel skin closure device and 47.6 seconds/cm using sutures (p<0.001). CONCLUSION: BandGrip is a novel skin closure device that allows for efficient surgical incision closure. Time to surgical skin incision closure is significantly less with the use of the novel skin closure device when compared with conventional sutures.

Osteochondral Allograft Transplant for Focal Cartilage Defects of the Femoral Condyles: Clinically Significant Outcomes, Failures, and Survival at a Minimum 5-Year Follow-up.

BACKGROUND: Osteochondral allograft (OCA) transplant for symptomatic focal cartilage defects in the knee has demonstrated favorable short- to midterm outcomes. However, the reoperation rate is high, and literature on mid- to long-term outcomes is limited. PURPOSE: To analyze clinically significant outcomes (CSOs), failures, and graft survival rates after OCA transplant of the femoral condyles at a minimum 5-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Review of a prospectively maintained database of 205 consecutive patients who had primary OCA transplant was performed to identify patients with a minimum of 5 years of follow-up. Outcomes including patient-reported outcomes (PROs), CSOs, complications, reoperation rate, and failures were evaluated. Failure was defined as revision cartilage procedure, conversion to knee arthroplasty, or macroscopic graft failure confirmed using second-look arthroscopy. Patient preoperative and surgical factors were assessed for their association with outcomes. RESULTS: A total of 160 patients (78.0% follow-up) underwent OCA transplant with a mean follow-up of 7.7 ± 2.7 years (range, 5.0-16.3 years). Mean age at the time of surgery was 31.9 ± 10.7 years, with a mean symptom duration of 5.8 ± 6.3 years. All mean PRO scores significantly improved, with 75.0% of patients achieving minimal clinically important difference (MCID), and 58.9% of patients achieving significant clinical benefit for the International Knee Documentation Committee score at final follow-up. The reoperation rate was 39.4% and was associated with a lower probability of achieving MCID. However, most patients undergoing reoperation did not proceed to failure at final follow-up (63.4% of total reoperations). A total of 34 (21.3%) patients had failures overall, and the 5- and 10-year survival rates were 86.2% and 81.8%, respectively. Failure was independently associated with greater body mass index, longer symptom duration, number of previous procedures, and previous failed cartilage debridement. Athletes were protected against failure. Survival rates over time were not affected by OCA site (P = .154), previous cartilage or meniscal procedure (P = .287 and P = .284, respectively), or concomitant procedures at the time of OCA transplant (P = .140). CONCLUSION: OCA transplant was associated with significant clinical improvement and durability at mid- to long-term follow-up, with 5- and 10-year survival rates of 86.2% and 81.8%, respectively. Maintenance of CSOs can be expected in the majority of patients at a mean of 7.7 years after OCA transplant. Although the reoperation rate was high (39.4%) and could have adversely affected chances of maintaining MCID, most patients did not have failure at long-term follow-up.

Return to Work After Primary Rotator Cuff Repair: A Systematic Review and Meta-analysis.

BACKGROUND: Rotator cuff tears are a prevalent pathology in injured workers, causing significant economic ramifications and time away from work. To date, published articles on work outcomes after rotator cuff repair have not been cumulatively assessed and analyzed. PURPOSE: To systematically review reports on return to work after rotator cuff repair and perform a meta-analysis on factors associated with improved work outcomes. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 4. METHODS: A systematic review of return-to-work investigations was performed using PubMed, Embase, and the Cochrane Database of Systematic Reviews in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Individual studies reporting rates of return to previous work with level of evidence 1 to 4 were independently screened by 2 authors for inclusion, and study quality was assessed using the Methodologic Index for Non-randomized Studies and Newcastle-Ottawa Scale. Work outcome data were synthesized and analyzed using random effects modeling to identify differences in rates of return to previous work as a function of operative technique, work intensity, and workers' compensation status. RESULTS: Thirteen retrospective investigations comprising 1224 patients who underwent rotator cuff repair met inclusion criteria for this investigation. Across all investigations, a weighted average of 62.3% of patients returned to previous level of work at 8.15 ± 2.7 months (mean ± SD) after surgery. Based on random effects modeling, higher rates of return to previous work were identified with decreasing work intensity (P < .001), while rates were similar between open and arthroscopic repair technique (P = .418) and between workers' compensation and non-workers' compensation cohorts (P = .089). All shoulder pain and functional outcome assessments demonstrated significant improvements at final follow-up when compared with baseline across all investigations. CONCLUSION: The majority of injured workers undergoing rotator cuff repair return to previous work at approximately 8 months after surgery. Despite this, >35% of patients are unable to return to their previous work level after their repair procedure. Similar rates of return to work can be anticipated regardless of workers' compensation status and operative technique, while patients in occupations with higher physical intensity experience inferior work outcomes.

Distal Tibial Allograft Augmentation for Posterior Shoulder Instability Associated With Glenoid Bony Deficiency: A Case Series.

PURPOSE: To report the clinical history and preliminary outcomes of patients who underwent posterior glenoid reconstruction using a distal tibial allograft (DTA) for the management of posterior shoulder instability with glenoid bone loss. METHODS: Patients who underwent posterior shoulder stabilization with a DTA in our institution between 2011 and 2019 were retrospectively reviewed. Demographic characteristics, operative reports, and clinical and functional outcomes were recorded. Outcomes included postoperative range of motion (ROM), recurrent instability, complications, and revision surgery. All patients underwent at least 1 year of follow-up, except 2 patients who underwent revision surgery. Preoperative and postoperative ROM was compared using the 2-tailed Student t test for paired samples. RESULTS: Ten patients who underwent DTA augmentation for posterior instability were included, comprising 2 female and 8 male patients with an average age of 24 years (range, 17-35 years). Five patients had a prior sports-related traumatic event, and 2 patients had a seizure disorder. Seven patients had undergone a prior stabilization procedure. The average reverse bony Bankart lesion was 26% of the glenoid diameter. Concomitant procedures included 4 capsular repairs, 2 labral repairs, 2 capsular plications, and 1 repair for humeral avulsion of the glenohumeral ligament. One patient reported recurrent instability after surgery. Two patients underwent revision surgery, with one removal of symptomatic hardware and one early revision owing to screw penetration into the glenoid. There was no significant difference in preoperative versus postoperative ROM. CONCLUSIONS: Posterior shoulder instability with significant bony deficiency can be managed using DTA augmentation with good outcomes and a reasonable complication rate in these challenging cases. LEVEL OF EVIDENCE: Level IV, case series.

Establishing the Minimal Clinically Important Difference, Patient Acceptable Symptomatic State, and Substantial Clinical Benefit of the PROMIS Upper Extremity Questionnaire After Rotator Cuff Repair.

BACKGROUND: The Patient-Reported Outcome Measurement Information System Upper Extremity (PROMIS UE) questionnaire has been validated as an effective and efficient outcome measure after rotator cuff repair (RCR). However, definitions of clinically significant outcomes used in interpreting this outcome measure have yet to be defined. PURPOSE: To define clinically significant outcomes of the PROMIS UE questionnaire in patients undergoing arthroscopic RCR. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: We reviewed charts of consecutive patients undergoing RCR in our institution between 2017 and 2018 and included patients who were administered the PROMIS UE before surgery and 12 months after surgery. At 12 months postoperatively, patients were asked domain-specific anchor questions regarding their function and satisfaction after surgery, which were then used to determine the minimal clinically important difference (MCID), Patient Acceptable Symptomatic State (PASS), and substantial clinical benefit (SCB) using receiver operating characteristic and area under the curve (AUC) analysis. Univariate and multivariate logistic regression analysis was utilized to identify patient factors associated with clinically significant outcomes. RESULTS: A total of 105 patients with RCR and minimum 12-month postoperative PROMIS UE were included in the analysis. The defined clinically significant outcomes were 4.87 for the MCID using a distribution-based method, 7.95 for the SCB (sensitivity, 0.708; specificity, 0.833; AUC, 0.760), and 39.00 for the PASS (sensitivity, 0.789; specificity, 0.720; AUC, 0.815). Among respondents, 79.0%, 62.9%, and 64.8% achieved the MCID, SCB, and PASS score thresholds, respectively. Workers' compensation was negatively associated with achievement of the PASS. Lower preoperative PROMIS UE scores were associated with obtaining the MCID (odds ratio [OR], 0.871; P = .001) and the SCB (OR, 0.900; P = .040), whereas higher preoperative scores were predictive of achieving the PASS (OR, 1.111; P = .020). CONCLUSION: This study defines the clinically significant outcomes for the PROMIS UE after RCR, of which the majority of patients achieved the MCID, PASS, and SCB at 12 months after surgery. These thresholds should be considered in future study design and interpretation of PROMIS UE in patients with RCR.

Recommendations to Optimize the Safety of Elective Surgical Care While Limiting the Spread of COVID-19: Primum Non Nocere.

COVID-19 has drastically altered our lives in an unprecedented manner, shuttering industries and leaving most of the country in isolation as we adapt to the evolving crisis. Orthopedic surgery has not been spared from these effects, with the postponement of elective procedures in an attempt to mitigate disease transmission and preserve hospital resources as the pandemic continues to expand. During these turbulent times, it is crucial to understand that although patients' and care-providers' safety is paramount, canceling or postponing essential surgical care is not without consequences and may be irreversibly detrimental to patients' health and quality of life in some cases. The optimal solution to how to balance effectively the resumption of standard surgical care while doing everything possible to limit the spread of COVID-19 is undetermined and could include such strategies as social distancing, screening forms and tests, including temperature screening, segregation of inpatient and outpatient teams, proper use of protective gear, and the use of ambulatory surgery centers (ASCs) to provide elective, yet ultimately essential, surgical care while conserving resources and protecting the health of patients and health care providers. Of importance, these recommendations do not and should not supersede evolving United States Centers for Disease Control and Prevention and relevant federal, state and local public health guidelines. LEVEL OF EVIDENCE: Level V.

Defining the Minimal Clinically Important Difference and Patient Acceptable Symptom State for Microfracture of the Knee: A Psychometric Analysis at Short-term Follow-up.

BACKGROUND: Several studies have investigated failure rates and magnitude of improvement in patient-reported outcome measures after microfracture surgery for focal chondral defects of the knee; however; what constitutes clinically significant improvement in this patient population is poorly understood. PURPOSE: To (1) establish the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) thresholds for microfracture surgery including the time-dependent nature of these thresholds and (2) identify predictors of achieving the MCID and PASS in patients specifically undergoing microfracture of the knee. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A secure institutional cartilage preservation repository was queried for all patients who underwent microfracture between 2004 and 2017. The distribution method was used to calculate MCID thresholds for the International Knee Documentation Committee (IKDC) score and the Knee injury and Osteoarthritis Outcome Score (KOOS), whereas an anchor-based method was used for the PASS. Multivariate logistic regressions were constructed to determine predictors of achieving the MCID and PASS. RESULTS: A total of 206 patients with a mean ± SD age of 33.7 ± 13.2 years and body mass index of 26.9 ± 5.3 kg/m2 were included. All thresholds for the MCID and PASS increased over time except for the MCID thresholds for the KOOS Sports and Symptoms subscales. The proportion of patients who achieved the MCID (6 months, 78.4%; 12 months, 83.9%; 24 months, 88.6%) and PASS (6 months, 67.7%; 12 months, 79.2%; 24 months, 76.1%) generally increased over time. Older age and larger lesion size were negative independent predictors of MCID achievement. Older age was also a negative predictor of the PASS, whereas male sex and higher preoperative KOOS Symptoms and Pain scores were positive independent predictors of the PASS. CONCLUSION: The MCID and PASS thresholds for the IKDC and KOOS in patients undergoing microfracture of the knee are dynamic, with an increasing number of patients achieving the MCID over time. The percentage achieving the PASS increased between 6 and 12 months and then declined slightly at 24 months. Independent predictors of achieving the MCID were lesion size and age at surgery, whereas predictors of achieving the PASS included lesion size, male sex, and greater preoperative KOOS Symptoms and Pain scores.

Meniscal Allograft Transplants.

Meniscus allograft transplantation is an established surgical treatment indicated in symptomatic meniscus-deficient patients with minimal to no arthritis. Treatment decision making should be individualized after a thorough history and physical examination, with diagnostic imaging and arthroscopy to assess the status of the meniscus. The senior author prefers to use a bridge-in-slot technique, where osseous fixation of the allograft is completed through passage of a bone bridge to a tibial slot. Outcomes in meniscus allograft transplantation are favorable, with reported significant improvements in clinical outcome and low failures in short- and midterm follow-up studies.

The Use of Platelet-Rich Plasma in Symptomatic Knee Osteoarthritis.

With average life expectancy and the rising prevalence of obesity, osteoarthritis (OA) is creating an increasingly large financial and physical burden on the U.S. population today. As the body ages and experiences trauma, articular cartilage surfaces in joints are gradually worn away, leading to OA. Traditionally, treatment options have included lifestyle modifications, pain management, and corticosteroid injections, with joint replacement reserved for those who have exhausted nonsurgical measures. More recently, hyaluronic acid, micronized dehydrated human amniotic/chorionic membrane tissue, and platelet-rich plasma (PRP) injections have started to gain traction. PRP has been shown to have both anti-inflammatory effects through growth factors such as transforming growth factor-ß and insulin-like growth factor 1, and stimulatory effects on mesenchymal stem cells and fibroblasts. Multiple studies have indicated that PRP is superior to hyaluronic acid and corticosteroids in terms of improving patient-reported pain and functionality scores. Unfortunately, there are many variations in PRP preparation, and lack of standardization in factors, such as speed and duration of centrifugation, leads to wide ranges of platelet and leukocyte concentrations. This review examines the current literature addressing the use of PRP in symptomatic knee OA and addresses suggestions for future studies in this area.

Use of Allografts in Orthopaedic Surgery: Safety, Procurement, Storage, and Outcomes.

The use of allografts has become a vital option for orthopaedic surgeons in the treatment of a variety of musculoskeletal lesions, ranging from osteochondral defects in the glenohumeral joint to meniscal deficiency in the young athlete. Nevertheless, barriers to treating a patient with an allograft-based procedure may arise from concerns over disease transmission, the navigation of tissue banks that supply allografts, the process of obtaining insurance approval, or optimal storage methods. This review serves to support orthopaedic surgeons in the incorporation of allografts into their practice by quelling these potential concerns. Fresh osteochondral allografts, fresh-frozen meniscal allografts, soft tissue allografts, and off-the-shelf cartilage products are the focus of this review amid broad overviews of allograft safety and tissue bank practices in the United States.

Preservation of Knee Articular Cartilage.

Hyaline articular cartilage is critical for the normal functioning of the knee joint. Untreated focal cartilage defects have the potential to rapidly progress to diffuse osteoarthritis. Over the last several decades, a variety of interventions aiming at preserving articular cartilage and preventing osteoarthritis have been investigated. Reparative cartilage procedures, such as microfracture, penetrate the subchondral bone plate in effort to fill focal cartilage defects with marrow elements and stimulate fibrocartilaginous repair. In contrast, restorative cartilage procedures aim to replace the defective articular surface with autologous or allogeneic hyaline cartilage. This review focuses on the preservation of articular cartilage, and discusses the current reparative and restorative surgical techniques available for treating focal cartilage defects.