Management of Chondral Lesions of the Knee: Analysis of Trends and Short-Term Complications Using the National Surgical Quality Improvement Program Database

A systematic review of cartilage procedures for unstable osteochondritis dissecans

OBJECTIVES

Osteochondritis dissecans can result in significant limitations in activity, pain, and early osteoarthritis. There are various treatment modalities to address these defects. The purpose of this study was to provide a qualitative summary of the various treatment options for unstable osteochondritis dissecans in the knee.

METHODS

A literature search was performed on osteochondritis dissecans in the knee using PubMed (MEDLINE), Embase, and Cochrane electronic databases. The search was completed using a combination of the following terms: 'osteochondritis dissecans,' 'OCD,' 'osteochondral,' 'articular cartilage,' 'repair,' 'surgery,' 'treatment,' 'osteochondral allograft,' 'autologous chondrocyte implantation,' 'unstable,' 'knee,' 'clinical studies.'

RESULTS

A total of 682 studies were found, of which 24 were included in the qualitative analysis. The quality score ranged from 46 to 80, and the mean follow-up ranged from 2 to 17 years. The most common surgical procedures were internal fixation (n = 7 studies), ACI (n = 6), fragment excision (n = 3), MACI (n = 2), bone graft + ACI (n = 2), OCA (n = 2), mosaicplasty/OAT (n = 2), and scaffold (n = 2). Overall, the reported outcome measures were heterogeneous in nature. Post-operative International Knee Documentations Committee (IKDC) scores ranged from 75 to 85 and Lysholm scores ranged from 70 to 93.5. Tegner scores ranged from 4 to 5. Rates of failure, complication, and revision were highly variable across studies and surgical techniques.

CONCLUSION

There are a variety of surgical options for the treatment of unstable osteochondritis dissecans. In skeletally immature patients, internal fixation demonstrated acceptable rates of radiographic union and patient reported outcome measures. In skeletally mature patients with large lesions, MACI and OCA transplantation provided similar patient reported outcomes.

Surgical Management of Failed Articular Cartilage Surgery in the Knee

Failure rates of cartilage restoration surgery range from 14% to 43%. When failure of prior cartilage restoration surgery is suspected, a thorough clinical workup should be performed to assess the timing and duration of symptoms. Attention should be paid to patient risk factors such as age, body mass index, and smoking status. Concomitant pathology such as malalignment, ligament insufficiency, and meniscus status must be evaluated before revision surgery. As outlined in our treatment algorithm, the size/location of the lesion and the type of primary procedure will guide planning for revision procedures. [Orthopedics. 2023;46(5):262-272.].

The Large Focal Isolated Chondral Lesion

Focal chondral defects (FCDs) of the knee can be a debilitating condition that can clinically translate into pain and dysfunction in young patients with high activity demands. Both the understanding of the etiology of FCDs and the surgical management of these chondral defects has exponentially grown in recent years. This is reflected by the number of surgical procedures performed for FCDs, which is now approximately 200,000 annually. This fact is also apparent in the wide variety of available surgical approaches to FCDs. Although simple arthroscopic debridement or microfracture are usually the first line of treatment for smaller lesions, chondral lesions that involve a larger area or depth require restorative procedures such as osteochondral allograft transplantation or other cell-based techniques. Given the prevalence of FCDs and the increased attention on treating these lesions, a comprehensive understanding of management from diagnosis to rehabilitation is imperative for the treating surgeon. This narrative review aims to describe current concepts in the treatment of large FCDs through providing an algorithmic approach to selecting interventions to address these lesions as well as the reported outcomes in the literature.

Prognostic Factors for the Clinical Outcome after Microfracture Treatment of Chondral and Osteochondral Defects in the Knee Joint: A Systematic Review

OBJECTIVE

The objective of this study is to establish which patient and lesion characteristics are related to the clinical outcome after microfracture of cartilage defects in the knee.

STUDY DESIGN

Systematic review.

METHODS

After preregistration, PubMed, Embase, and Cochrane were searched for studies that analyzed prognostic factors for the outcome of microfracture treatment in the knee. The criteria for inclusion were outcome measured using Patient-Reported Outcome Measures (PROMs), a clinical study with ≥10 participants receiving microfracture, and a minimal follow-up period of 1 year.

RESULTS

For none of the investigated prognostic factors, effect size reporting was sufficiently homogeneous to conduct a meta-analysis. However, a majority of the included studies identified higher age, larger lesion size, longer preoperative symptom duration, and previous surgery on the ipsilateral knee, especially meniscectomy and anterior cruciate ligament reconstruction, as factors that are reported to be correlated to a less favorable outcome. A lesion location that does not include the trochlea or the patellofemoral joint and is not weightbearing, a nondegenerative mechanism of injury, and a single lesion were reported as factors that predict a favorable outcome. As to gender, body mass index, preoperative activity level, smoking, and concomitant knee surgery, the included articles were inconclusive or no effect was reported.

CONCLUSIONS

Several factors correlated with the clinical result after microfracture treatment. However, the information on the effect sizes of the influence on clinical outcome is incomplete due to poor reporting. Large-scale registries or pooling of homogeneous, well-reported data is needed to work toward prognostic models. That would be an important step toward personalized treatment.

Nanowarming and ice-free cryopreservation of large sized, intact porcine articular cartilage

Successful organ or tissue long-term preservation would revolutionize biomedicine. Cartilage cryopreservation enables prolonged shelf life of articular cartilage, posing the prospect to broaden the implementation of promising osteochondral allograft (OCA) transplantation for cartilage repair. However, cryopreserved large sized cartilage cannot be successfully warmed with the conventional convection warming approach due to its limited warming rate, blocking its clinical potential. Here, we develope a nanowarming and ice-free cryopreservation method for large sized, intact articular cartilage preservation. Our method achieves a heating rate of 76.8 °C min-1, over one order of magnitude higher than convection warming (4.8 °C min-1). Using systematic cell and tissue level tests, we demonstrate the superior performance of our method in preserving large cartilage. A depth-dependent preservation manner is also observed and recapitulated through magnetic resonance imaging and computational modeling. Finally, we show that the delivery of nanoparticles to the OCA bone side could be a feasible direction for further optimization of our method. This study pioneers the application of nanowarming and ice-free cryopreservation for large articular cartilage and provides valuable insights for future technique development, paving the way for clinical applications of cryopreserved cartilage.

Trends in Lateral Retinacular Release from 2010 to 2017

Historically, lateral retinacular release (LRR) procedures have been utilized in the treatment of a variety of patellofemoral disorders, including lateral patellar instability. However, in the past decade, there has been an increasing awareness of the importance of the lateral stabilizers in patellar stability, as well as the complications of LRR, such as recurrent medial patellar instability. The purpose of this study was to investigate current trends in LRR procedures from 2010 through 2017 using a large national database. The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for arthroscopic LRR procedures (the Current Procedural Terminology [CPT] code, 29873) from 2010 to 2017. The number and incidence of lateral release procedures, both isolated and nonisolated, were analyzed and separated into cohorts for analysis. Age and gender of the LRR cohort was investigated and compared with all other orthopaedic procedures during the same time period in the NSQIP database. In addition, concomitant procedures and associated International Classification of Disease-9th Revision (ICD-9) and ICD-10th Revision (ICD-10) codes were analyzed over time and between LRR groups. From 2010 to 2017, 3,117 arthroscopic LRRs were performed. The incidence for LRR was 481.9 per 100,000 orthopaedic surgeries in 2010 and significantly decreased to 186.9 per 100,000 orthopaedic surgeries in 2017 (p < 0.01). LRR was more commonly performed in females (66%) and 58% of patients were under 44 years of age. In addition, LRR was most commonly performed with a concomitant meniscectomy (36%), synovectomy (19%), or microfracture (13%), and for a diagnosis of pain (22%). The overall incidence of LRR procedures significantly decreased from 2010 to 2017. LRRs were more commonly performed in younger, female patients for a diagnosis of pain with the most common concomitant procedure being meniscectomy, synovectomy, or microfracture.

Reoperation After Osteochondral Autograft and Allograft Transfer in the Pediatric Knee

Osteochondral autograft (OAU) transfer and osteochondral allograft (OAL) transfer are options for treating sizable articular cartilage lesions in the knee, but there is little evidence to support one technique over another. The goal of this study is to compare the rate of reoperation among children and adolescents undergoing OAU or OAL of the knee. In this retrospective cohort study, the Pediatric Health Information System, a national database consisting of 49 children's hospitals, was queried for all patients undergoing OAU and OAL between 2012 and 2018. A total of 732 subjects with a mean age of 15.4±2.4 years were included. Of these, 393 (53.7%) initially underwent OAL and 339 (46.3%) underwent OAU. The overall reoperation rate was 144 of 732 (19.7%) at a median of 6.6 months (range, 0.6-53.5 months) after the index operation. This rate was similar for OAL and OAU. For 18 subjects (2.5%), OAU, OAL, or autologous chondrocyte implantation (ACI) was performed at the time of revision surgery. When analyzing only open procedures, we found that the reoperation rate was 25.5% for open OAU compared with 16.5% for open OAL (P=.03). When adjusting for covariates in multivariate regression, we found that those who underwent open OAU had 1.7 times higher odds of requiring a future reoperation than those who underwent open OAL (95% CI, 1.1-2.8; P=.04). Although the rate of reoperation after OAU or OAL among children and adolescents is relatively high, few require revision OAU, OAL, or ACI. Patients undergoing open OAU have higher odds of ultimately requiring reoperation than those undergoing open OAL. [Orthopedics. 2022;45(6):378-383.].

Satisfactory clinical outcomes with autologous matrix-induced chondrogenesis in the treatment of grade IV chondral injuries of the knee

OBJECTIVE

The research aims to evaluate short- and medium-term outcomes of patients treated using autologous matrix-induced chondrogenesis (AMIC) with a hyaluronic acid scaffold (Hyalofast, Anika Therapeutics, MA, USA) in grade IV chondral lesions according to the Outerbridge classification in the knee.

METHODS

This is a multicentre, non-randomized, retrospective study conducted between 2017 and 2022. To determine the clinical outcome of the patients, the follow-up was done with the subjective International Knee Documentation Committee (IKDC) score, pre-surgery, and with a follow-up at 12, 24, and 32 months.

RESULTS

Fifty patients (28 female) with a mean age of 45.9 ± 12.7 years were recruited. The mean size of the lesion was 3.5 cm², and the injuries located in the patella (30%) and trochlear groove (24%) were the most frequent. The total IKDC clinical score significantly increased from baseline to the 32 months of follow-up with a mean difference of 36.4 (95% CI, 29.1-43.7, p < 0.001). Besides, there was a statistically significant improvement in all categories of the IKDC (symptoms, sports activities, function, and activity of daily living) compared between pre-surgery and 24 and 32 months of follow-up. The patients younger than 45 years presented better clinical outcomes than older ones with a difference between medians of 10.40 (95% CI, 1.10-11.50, p = 0.0247), and a negative correlation was found between the 32-month IKDC score and the age. In addition, no statistically significant difference was found when comparing the last results of the IKDC between patients with and without associated surgical procedures or between patients with single and several lesions, neither nor between men and women. The level of satisfaction with the procedure of all the patients, on a score of 1-10, was on average 8 ± 1.5.

CONCLUSION

Results of this study indicate that patients who underwent the AMIC procedure with hyaluronic acid scaffold for the treatment of grade IV chondral lesions in the knee presented satisfactory results throughout the follow-up.

LEVEL OF EVIDENCE

Level IV.

Evaluation of Commercially Available Knee Cartilage Restoration Techniques Stratified by FDA Approval Pathway

BACKGROUND

Commercially available products used in knee cartilage reconstructive and restorative surgical practices fall under unique US Food and Drug Administration (FDA) regulatory pathways that determine the level of evidence required to market each product.

PURPOSE

To evaluate the levels of evidence in the literature supporting commercially available cartilage repair procedures stratified by FDA regulatory pathway (section 351 vs section 361 of "Human Cells, Tissues, and Cellular and Tissue-Based Products" [HCT/P] in the Code of Federal Regulation) with the hypothesis that products requiring approval under a stringent regulatory pathway (351 HCT/P) have higher levels of evidence in the literature supporting use and that products with a less stringent regulatory pathway (361 HCT/P) have a higher number of products available for use in the United States.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A search of the PubMed database was performed to identify all peer-reviewed articles pertaining to either allograft or autologous cartilage repair technologies. Predefined inclusion and exclusion criteria were used to find clinical, preclinical, and laboratory studies while excluding duplicates, systematic reviews, and products not available in the United States. Articles were categorized by regulatory pathway (351 and 361 HCT/P), and variables including publication year, type of publication, level of evidence, and number of publications were analyzed.

RESULTS

After application of predefined criteria, 470 of 1924 articles were included in this study. The 351 HCT/P group was composed entirely of autologous chondrocyte implantation (ACI) technology; 94% of the 361 HCT/P group was composed of osteochondral allografts (OCA). The articles regarding 351 HCT/P were more likely to be clinical in nature than the articles on 361 HCT/P (80% vs 48%, respectively; P = .0001) and entailed significantly more level 1 studies (25 vs 0, respectively; P < .0001). Twice as many articles in the 351 HCT/P group were published in the American Journal of Sports Medicine compared with the 361 HCT/P group (71 vs 38, respectively; P = .18).

CONCLUSION

Both ACI and OCA have robust evidence supporting their use, whereas the remaining regulated products have little or no supporting evidence. Technologies regulated by 351 HCT/P were more likely to be level 1 clinical studies and published in the highest impact journal. The 361 HCT/P pathway regulated many more products, with fewer articles supporting their use.

Treatment of Cartilage Defects of the Knee in Military Tactical Athletes: An Overview of Management and Clinical Outcomes

Cartilage defects of the knee are a common problem that can be caused by trauma or chronic repetitive overload and result in debilitating functional limitations. These consequences are of particular significance to military service members, who, by in large, are a group of young, active individuals with professional duties requiring full, unrestricted activity and function. The burden of knee chondral-related disease among military tactical athletes is well established, and systematic approach to the evaluation of a military member with suspected knee chondral pathology facilitates the execution of a surgical procedure that maximizes the likelihood of a return to duty. Despite advances in cartilage restoration surgery, chondral pathology of the knee remains a vexing problem and an omnipresent threat to military medical readiness and warfighter lethality.

Evaluation of Electrospun PCL-PLGA for Sustained Delivery of Kartogenin

In this study, kartogenin was incorporated into an electrospun blend of polycaprolactone and poly(lactic-co-glycolic acid) (1:1) to determine the feasibility of this system for sustained drug delivery. Kartogenin is a small-molecule drug that could enhance the outcome of microfracture, a cartilage restoration procedure, by selectively stimulating chondrogenic differentiation of endogenous bone marrow mesenchymal stem cells. Experimental results showed that kartogenin did not affect the electrospinnability of the polymer blend, and it had negligible effects on fiber morphology and scaffold mechanical properties. The loading efficiency of kartogenin into electrospun membranes was nearly 100%, and no evidence of chemical reaction between kartogenin and the polymers was detected by Fourier transform infrared spectroscopy. Analysis of the released drug using high-performance liquid chromatography-photodiode array detection indicated an abundance of kartogenin and only a small amount of its major hydrolysis product. Kartogenin displayed a typical biphasic release profile, with approximately 30% being released within 24 h followed by a much slower, constant rate of release up to 28 days. Although additional development is needed to tune the release kinetics and address issues common to electrospun scaffolds (e.g., high fiber density), the results of this study demonstrated that a scaffold electrospun from biodegradable synthetic polymers is a suitable kartogenin delivery vehicle.

Incidence and risk factors for symptomatic venous thromboembolism following anterior cruciate ligament reconstruction

PURPOSE

To determine the incidence of symptomatic venous thromboembolism (VTE) following anterior cruciate ligament (ACL) reconstruction using a large national database and to identify corresponding independent risk factors.

METHODS

The Humana administrative claims database was reviewed for patients undergoing ACL reconstruction from 2007 to 2017. Patient demographics, medical comorbidities, as well as concurrent procedures were recorded. Postoperative incidence of VTE was measured by identifying symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) at 30 days, 90 days, and 1 year postoperatively. Univariate analysis and binary logistic regression were performed to determine independent risk factors for VTE following surgery.

RESULTS

A total of 11,977 patients were included in the study. The incidence of VTE was 1.01% (n = 120) and 1.22% (n = 146) at 30 and 90 days, respectively. Analysis of VTE events within the first postoperative year revealed that 69.6% and 84.3% of VTEs occurred within 30 and 90 days of surgery, respectively. Logistic regression identified age ≥ 45 (odds ratio [OR] = 1.88; 95% confidence interval [CI] 1.32-2.68; p < 0.001), inpatient surgery (OR = 2.07; 95% CI 1.01-4.24; p = 0.045), COPD (OR = 1.51; 95% CI 1.02-2.24; p = 0.041), and tobacco use (OR = 1.75; 95% CI 1.17-2.62; p = 0.007), as well as concurrent PCL reconstruction (OR = 3.85; 95% CI 1.71-8.67; p = 0.001), meniscal transplant (OR = 17.68; 95% CI 3.63-85.97; p < 0.001) or osteochondral allograft (OR = 15.73; 95% CI 1.79-138.43; p = 0.013) as independent risk factors for VTE after ACL reconstruction.

CONCLUSIONS

The incidence of symptomatic postoperative VTE is low following ACL reconstruction, with the majority of cases occurring within 90 days of surgery. Risk factors include age ≥ 45, inpatient surgery, COPD, tobacco use and concurrent PCL reconstruction, meniscal transplant or osteochondral allograft.

LEVEL OF EVIDENCE

III.

Differences in Clinical and Functional Outcomes Between Osteochondral Allograft Transplantation and Autologous Chondrocyte Implantation for the Treatment of Focal Articular Cartilage Defects

Background:

Articular cartilage pathology can result from a spectrum of origins, including trauma, osteochondritis dissecans, avascular necrosis, or degenerative joint disease.

Purpose:

To compare the differences in clinical and patient-reported outcomes after autologous chondrocyte implantation (ACI) versus osteochondral allograft transplantation (OCA) in patients with focal articular cartilage defects without underlying bone loss.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective review identified patients who underwent ACI or OCA between 2008 and 2016 for isolated grades 3 and 4 articular cartilage defects without underlying bone loss. Outcome measures included the Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), International Knee Documentation Committee (IKDC) evaluation, and 12-Item Short Form Health Survey–Physical Component (SF-12-P) scores. Defect location, size, complications, and rate of subsequent surgery were determined.

Results:

Overall, 148 patients were included: 82 (55%) underwent ACI and 66 (45%) underwent OCA. The mean age at the time of surgery was 31.2 years within the ACI cohort and 37.7 years within the OCA cohort (P < .001); the mean follow-up for both cohorts was 6.7 years (P = .902). Within the ACI group, 28 (34%) patients had multifocal defects, 21 (26%) had defects confined to the femoral condyles, and 33 (40%) had defects in the patellofemoral region. Within the OCA group, 23 (35%) patients had multifocal defects, 30 (46%) had confined femoral condyle lesions, and 13 (20%) had patellofemoral defects. When comparing by lesion location, there were no significant differences in KOOS JR, and IKDC scores between the ACI and OCA cohorts (P < .05). There was, however, a significant difference for SF-12-P scores for FDD trochlear lesions. In both cohorts, traumatic patellofemoral pathology demonstrated lower patient-reported outcomes and higher failure rates than degenerative lesions. The overall rate of failure, defined as graft failure with revision surgery and/or conversion to arthroplasty, was significantly greater in the OCA group (21% vs 4%; P = .002).

Conclusion:

Study results indicated that ACI provides similar outcomes to OCA with or without concomitant procedures for the treatment of symptomatic articular cartilage defects in all lesion locations and may have a lower revision rate for multifocal and condylar lesions.

Time Matters: Knee Cartilage Defect Expansion and High-Grade Lesion Formation while Awaiting Autologous Chondrocyte Implantation

OBJECTIVE

The objective of this study was to assess potential risk factors, including time delay until implantation, for knee cartilage defect expansion or new high-grade defect formation between biopsy and Autologous Chondrocyte Implantation (ACI) or Matrix Autologous Chondrocyte Implantation (MACI).

STUDY DESIGN

Consecutive knee ACI and MACI cases by a single surgeon (n = 111) were reviewed. The relationship between time between biopsy and staged implantation and (1) progression in primary cartilage defect size and (2) development of a new high-grade (Outerbridge grade ≥3) cartilage defect were determined with adjustment for demographics, body mass index, smoking status, coronal alignment, initial cartilage status, and prior surgery.

RESULTS

Average size of the primary defect at time of biopsy was 4.50 cm². Mean time to chondrocyte implantation was 155 days. Defect expansion increased 0.11 cm² (standard error = 0.03) per month delay to implantation (P = 0.001). Independent predictors of defect expansion were male sex, smaller initial defect size, and delay to implantation (adjusted mean = 0.15 cm² expansion per month). A total of 16.2% of patients (n = 18/111) developed a new high-grade defect. Independent predictors of a new secondary defect were Outerbridge grade 2 changes (vs. 0-1) on the surface opposing the index defect and delayed implantation (per month increase, adjusted odds ratio = 1.21, 95% confidence interval: 1.01-1.44; P = 0.036).

CONCLUSIONS

Patients undergoing 2-stage cell-based cartilage restoration with either ACI or MACI demonstrated long delays between stages of surgery, placing them at risk for expanding defects and development of new high-grade cartilage defects. Patients who were male, had smaller initial defect size, and longer time between surgeries were at greater risk for defect expansion.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Differences in the Demographics and Preferred Management of Knee Cartilage Injuries in Soccer Players Across FIFA Centers of Excellence

OBJECTIVE

We sought to report on the demographics and epidemiology of knee cartilage injuries and preferred management in soccer players, across FIFA Medical Centers of Excellence (FMCE).

DESIGN

A descriptive questionnaire focusing on characteristics of knee cartilage injuries and their management in soccer players during the 10-year period prior to the distribution of the questionnaire was sent to all FMCE around the world in September 2019 via an online platform. Voluntary responses from centers were processed and analyzed. Descriptive characteristics were reported using median and interquartile ranges (IQR) for continuous variables and frequencies and percentages (%) for discrete variables.

RESULTS

A total of 15 centers from 5 continents responded to the questionnaire and reported on a total of 4526 soccer players. Among centers, the median age was 27 years (IQR: 23-38), the median rate of male players was 75% (IQR: 68-90), and the median rate of professional players was 10% (IQR: 5-23). The most common reported etiology for cartilage injury was traumatic (median 40%, IQR: 13-73). The most common nonoperative treatment utilized was physical therapy (median 90%, IQR: 51%-100%) and the most common operative treatment utilized was bone marrow stimulation/micro-fracture (median 40%, IQR: 19-54%). The utilization of other cartilage restoration procedures varied across centers.

CONCLUSIONS

Our findings highlight different tendencies in the management of these injuries across FMCE and emphasize the need for collaborative efforts focusing on establishing consensus guidelines for the optimal management of these challenging injuries in soccer players.

Collagen type II: From biosynthesis to advanced biomaterials for cartilage engineering

Collagen type II is the major constituent of cartilage tissue. Yet, cartilage engineering approaches are primarily based on collagen type I devices that are associated with suboptimal functional therapeutic outcomes. Herein, we briefly describe cartilage's development and cellular and extracellular composition and organisation. We also provide an overview of collagen type II biosynthesis and purification protocols from tissues of terrestrial and marine species and recombinant systems. We then advocate the use of collagen type II as a building block in cartilage engineering approaches, based on safety, efficiency and efficacy data that have been derived over the years from numerous in vitro and in vivo studies.

Treatment of knee osteochondritis dissecans with autologous tendon transplantation: Clinical and radiological results

BACKGROUND

Defect treatment with tendon autograft in osteochondral lesions has been published in the literature with an experimental study in dogs. To demonstrate that it is possible to treat knee osteochondral lesions with the technique of autologous tendon transplantation.

AIM

To evaluate the clinical and radiological results of patients with knee osteochondral lesions who were treated with autologous tendon transplantation.

METHODS

Twenty patients (22 knees) with osteochondritis dissecans (OCD) lesions involving the knee were treated with autologous tendon transplantation between 2005-2018. All lesions were International Cartilage Repair Society grade IV. All patients were evaluated clinically at final follow-up with knee injury and osteoarthritis outcome score (KOOS); and radiologically with magnetic resonance observation and cartilage repair tissue (MOCART) and Kellgren-Lawrence (KL) classification.

RESULTS

A total of 20 patients (22 knees) with a mean age of 25.5± 6.8 years were included. The average defect size was 4.2 ± 2.1 cm², and the average defect depth was 0.9 ± 0.4 cm. Total KOOS score was preoperatively 29.4 ± 5.5 and was later found to be 81.5 ± 5.9 after an average of 68.7 ± 37.7 mo follow-up. The mean MOCART score was 56.2 ± 10.7. Preoperatively, all of the patients had KL grades of 0–1; during the follow-up period, 80% of the patients showed no radiological progress of osteoarthritis. Patients with less than 4 cm² lesion had statistically significantly better overall KOOS than patients whose more than 4 cm² lesion, particularly in sport and quality of life subscales.

CONCLUSION

The autologous tendon transplantation is a single-step, safe, simple, cost-effective method for the treatment of knee OCD with satisfactory clinical and radiological outcomes, particularly in patients with less than 4 cm² lesion.

A Systematic Review of Focal Cartilage Defect Treatments in Middle-Aged Versus Younger Patients

Background:

Focal cartilage defects are often debilitating, possess limited potential for regeneration, are associated with increased risk of osteoarthritis, and are predictive for total knee arthroplasty. Cartilage repair studies typically focus on the outcome in younger patients, but a high proportion of treated patients are 40 to 60 years of age (ie, middle-aged). The reality of current clinical practice is that the ideal patient for cartilage repair is not the typical patient. Specific attention to cartilage repair outcomes in middle-aged patients is warranted.

Purpose:

To systematically review available literature on knee cartilage repair in middle-aged patients and include studies comparing results across different age groups.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic search was performed in EMBASE, MEDLINE, and the Cochrane Library database. Articles were screened for relevance and appraised for quality.

Results:

A total of 21 articles (mean Coleman Methodology Score, 64 points) were included. Two out of 3 bone marrow stimulation (BMS) studies, including 1 using the microfracture technique, revealed inferior clinical outcomes in middle-aged patients in comparison with younger patients. Nine cell-based studies were included showing inconsistent comparisons of results across age groups for autologous chondrocyte implantation (ACI). Bone marrow aspirate concentrate showed age-independent results at up to 8 years of follow-up. A negative effect of middle age was reported in 1 study for both ACI and BMS. Four out of 5 studies on bone-based resurfacing therapies (allografting and focal knee resurfacing implants [FKRIs]) showed age-independent results up to 5 years. One study in only middle-aged patients reported better clinical outcomes for FKRIs when compared with biological repairs.

Conclusion:

Included studies were heterogeneous and had low methodological quality. BMS in middle-aged patients seems to only result in short-term improvements. More research is warranted to elucidate the ameliorating effects of cell-based therapies on the aging joint homeostasis. Bone-based therapies seem to be relatively insensitive to aging and may potentially result in effective joint preservation. Age subanalyses in cohort studies, randomized clinical trials, and international registries should generate more evidence for the large but underrepresented (in terms of cartilage repair) middle-aged population in the literature.

Cartilage Restoration of Bipolar Lesions Within the Patellofemoral Joint Delays Need for Arthroplasty: A Systematic Review of Rates of Failure

Purpose

The purpose of the present review is to systematically review the available literature for failure rates and complications of cartilage restoration of bipolar chondral defects in the patellofemoral (PF) joint to assess the ability to treat these lesions without arthroplasty.

Methods

PubMed and MEDLINE databases were queried between 2000 to 2020 using the keywords "osteochondral" and "knee" and "microfracture," "autologous chondrocyte implantation (ACI)," or "transplantation." Patient selection included patients with bipolar chondral lesions of the patellofemoral joint that were treated with cartilage restoration procedures. Treatment of PF joints were reviewed for surgical indications/technique, rates of failure, defect characteristics, and time to failure. For the purposes of this study, failure was defined by each individual author on their respective studies.

Results

After screening 1,295 articles, there were 8 publications analyzed quantitatively and 10 articles analyzed both quantitatively and qualitatively. A total of 249 knees involved bipolar lesions of the patellofemoral joint. The weighted average age was 36.5 ± 10.4 years, and weighted average follow-up was 89.0 ± 31.7 months. There were failures in 0% to 50% of cases, revision procedures in 0% to 10% of cases, conversion to arthroplasty in in 0% to 50% of cases, and unsatisfactory outcome without revision in 0% to 8.3% of cases. The range in average failure rate was 0% to 50.0% (I² = 68.0%), whereas the range in average time to failure was 2.9 to 6.8 years (I² = 79.0%).

Conclusion

From the available data, established cartilage restoration procedures may provide favorable patient-reported function, avoidance of secondary surgery, and joint preservation in at least 80% of patients at short- to mid-term follow-up.

Level of Evidence

Level IV, systematic review of Level IV studies.

Chondral Lesions of the Knee: An Evidence-Based Approach

➤

Management of chondral lesions of the knee is challenging and requires assessment of several factors including the size and location of the lesion, limb alignment and rotation, and the physical and mental health of the individual patient.

➤

There are a multitude of options to address chondral pathologies of the knee that allow individualized treatment for the specific needs and demands of the patient.

➤

Osteochondral autograft transfer remains a durable and predictable graft option in smaller lesions (<2 cm2) in the young and active patient population.

➤

Both mid-term and long-term results for large chondral lesions (≥3 cm2) of the knee have demonstrated favorable results with the use of osteochondral allograft or matrix-associated chondrocyte implantation.

➤

Treatment options for small lesions (<2 cm2) include osteochondral autograft transfer and marrow stimulation and/or microfracture with biologic adjunct, while larger lesions (≥2 cm2) are typically treated with osteochondral allograft transplantation, particulated juvenile articular cartilage, or matrix-associated chondrocyte implantation.

➤

Emerging technologies, such as allograft scaffolds and cryopreserved allograft, are being explored for different graft sources to address complex knee chondral pathology; however, further study is needed.

Managing Chondral Lesions: A Literature Review and Evidence-Based Clinical Guidelines

BACKGROUND

Articular cartilage lesions are becoming increasingly common. Optimum diagnosis and management of chondral defects cause a lot of dilemma. A number of surgical methods have been reported in the literature for treating focal cartilage defects. There is a lack of consensus on the most effective management strategy, with newer surgical and cell-based treatments being advocated regularly.

STUDY DESIGN AND METHODS

A clinical review is constructed by appraising the published literature about clinical evaluation and diagnostic modalities for articular cartilage defects and subsequent surgical procedures, management strategies employed for such lesions. Prominent available databases (PUBMED, EMBASE, Cochrane) were also searched for trials comparing functional outcomes following cartilage procedures. Synthesis of a practical management guideline is then attempted based on the evidence assessed.

RESULTS

Systematic examination and optimal use of diagnostic imaging are an important facet of cartilage defect management. Patient and lesion factors greatly influence the outcome of cartilage procedures and must be considered while planning management. Smaller lesions < 2 cm² respond well to all treatment modalities. Autologous osteochondral transplants (OATs) are effective in high activity individuals with intermediate lesions. For larger lesions > 4 cm², newer generation autologous chondrocyte implantation (ACI) has shown promising and durable results. Stem cells with scaffolds may provide an alternate option. Orthobiologics are a useful adjunct to the surgical procedures, but need further evaluation.

CONCLUSIONS

Most treatment modalities have their role in appropriate cases and management needs to be individualized for patients. The search for the perfect cartilage restoration procedure continues.

Arthroscopic debridement for focal articular cartilage lesions of the knee: A systematic review

BACKGROUND AND PURPOSE OF THE STUDY

Arthroscopic debridement, the most commonly applied surgical technique for focal cartilage lesions in the knee, is not included in most treatment algorithms because of discouraging results in the management of osteoarthritis of the knee. The present systematic review evaluates the outcome of arthroscopic cartilage debridement as the primary treatment of focal knee chondral lesions in adults, and defines its indications and role as the primary treatment of focal knee chondral lesions.

METHODS

Two independent investigators searched PubMed, Cochrane CENTRAL, and Virtual Health Library databases using the terms "knee", "cartilage", "chondral", "lesions", "injury", "damage", "debridement", "chondroplasty", "chondrectomy", alone and in combination. Clinical studies evaluating the effect of mechanical cartilage debridement in adults with symptomatic focal cartilage lesions in the knee joint regardless of the defect size and depth were included. We excluded studies if patients had a concomitant ligament or meniscus injury, and/or had additional debridement with monopolar radiofrequency energy.

MAIN FINDINGS

Available studies suggest good to excellent short and medium-term functional outcomes (KOOS, LKSS, Tegner scale) for focal cartilage lesions treated with debridement regardless of the defect size and depth. Data are lacking comparing cartilage debridement versus other cartilage repair techniques.

CONCLUSIONS

Arthroscopic debridement of focal articular cartilage lesions of the knee is associated with good to excellent short and medium-term postoperative outcomes, especially in terms of functional improvement. Arthroscopic debridement may be considered in the primary treatment of focal cartilage injuries regardless of the defect size and depth. However, available studies are limited and the level of evidence is low.

Arthroscopic versus Open Osteochondral Autograft Transplantation (Mosaicplasty) for Cartilage Damage of the Knee: A Systematic Review

Osteochondral autograft transplantation (OAT) is a surgical option for repairing cartilage damage in knees, and can be performed using open or arthroscopic procedures. The aim of this review was to report clinical outcomes, postoperative complications, defect location, and defect size between open and arthroscopic OATs. Three electronic databases (EMBASE, PUBMED, and MEDLINE) were searched for relevant articles. In regard to eligibility criteria, knee articular damage cases solely treated with OAT were included and cases concomitant with ligament reconstruction, limb realignment, and meniscus repair were excluded. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and descriptive statistics are presented. A total of 24 studies were included with a total sample of 1,139 patients (532 in open OAT vs. 607 in arthroscopic OAT). Defect size in open OAT was three times larger than that of arthroscopic OAT (2.96 ± 0.76 vs. 0.97 ± 0.48 cm²). In terms of defect location, the medial femoral condyle (MFC) was the most common (75.4%), followed by the lateral femoral condyle (LFC; 12.1%), patella (6.7%), and trochlea (5.7%). All of these defect locations were treated with open OAT, whereas arthroscopic OAT treatments were restricted to the MFC and LFC. The clinical outcomes were overall favorable with the modified Hospital for Special Surgery knee scores being 89.6 ± 8.0 (36.1-month follow-up) versus 90.4 ± 6.0 (89.5-month follow-up) and the Lysholm scores being 81.6 ± 8.9 (44.2-month follow-up) and 83.3 ± 7.4 (12.0-month follow-up) between open and arthroscopic OATs, respectively. Fifty-three postoperative complications were observed (39/279 vs. 14/594) and the most common complication was hemarthrosis (13/39 in open, vs. 1/14 in arthroscopic OAT). The overall clinical outcomes were favorable in open and arthroscopic OATs, whereas open OAT allowed for treatment of lesions approximately three times greater in dimension than in arthroscopic OAT. Also, defect location was restricted to MFC and LFC in arthroscopic OAT. The most common complication was hemarthrosis.

Arthroscopic Minced Cartilage Implantation (MCI): A Technical Note

Articular cartilage lesions are identified with increasing frequency. Several cartilage repair techniques are available to treat symptomatic cartilage defects. The ultimate goal of any cartilage repair procedure is the prevention of premature osteoarthritis. Autologous chondrocyte implantation provides the best tissue quality. However, 2 operations and a resource-intense culturing process with high regulatory demands are disadvantages of this cartilage repair procedure. Furthermore, cellular dedifferentiation and senescence display further cell culture-associated drawbacks that hamper the procedure. Minced cartilage implantation is a relatively simple and cost-effective one-step procedure with promising biologic potential and satisfying clinical results. We present an arthroscopic surgical technique where the surgeon can apply autologous chondrocytes in a one-step procedure to treat articular cartilage defects at the knee joint.

BioCartilage augmentation of marrow stimulation procedures for cartilage defects of the knee: Two-year clinical outcomes

BACKGROUND

The present study evaluated short-term outcomes of microfracture augmented with micronized allograft cartilage matrix (BioCartilage) and platelet-rich plasma (PRP) for symptomatic focal femoral condyle or trochlea cartilage defects.

METHODS

Patients who underwent microfracture augmented with BioCartilage and PRP for isolated contained chondral defects were evaluated. Magnetic resonance imaging (MRI) was performed at one year postoperatively. Two-year postoperative outcomes included patient-reported outcome measures (PROMs) and rates of return-to-work and return-to-sport.

RESULTS

Mean age of the 10 patients who completed the study was 39.7 years (range, 19-66 years), and five (50%) were female. Mean post-debridement defect size of the five femoral condyle and five trochlea defects was 2.4 cm² (range, 0.7-5.0 cm²). One-year postoperative MRI analysis demonstrated that two chondral lesions were <50% filled, four sites were >50% filled, two sites were completely filled, and two sites had hypertrophied. Patients experienced improvements in three PROMs at six months, one year, and two years postoperatively (p < 0.01). Postoperative Marx Activity scores revealed no decrease in activity level compared to baseline preoperatively. Nine patients (90%) returned to their pre-injury level of work by one year postoperatively and remained at that level through two years postoperatively.

CONCLUSIONS

Our findings suggest that small, contained focal chondral injuries in the femoral condyle and trochlea treated with a marrow stimulation procedure augmented with BioCartilage and PRP are associated with significant improvements in patient-reported outcomes at two years postoperatively. Further studies are needed to evaluate the long-term durability and imaging characteristics of this intervention. Level of evidence Therapeutic Level IV.

Editorial Commentary: Aragonite-Based Implants for Osteochondral Defects-Could Coral Make Old Goats Run Again?

The population of patients with early arthritis remains a treatment challenge because of the specifics of their disease (diffuse chondrosis rather than focal defect, frequent associated morbidities such as instability or meniscal deficiency) and where they are in life (young, active, working). Too young with "not enough damage" for arthroplasty but frequently unresponsive to conservative care, they are in the midst of life yet functionally quite limited. The next generation of non-arthroplasty implants is being investigated to potentially bridge this treatment gap and provide relief for the ever-growing number of young patients with arthritis.

Evidence that reduction in volume protects in situ articular chondrocytes from mechanical impact

Chondrocytes, the resident cells in articular cartilage, carry the burden of producing and maintaining the extracellular matrix (ECM). However, as these cells have a low proliferative capacity and are not readily replaced, chondrocyte death due to extreme forces may contribute to the pathogenesis of osteoarthritis (OA) after injury or may inhibit healing after osteochondral transplantation, a restorative procedure for damaged cartilage that requires a series of mechanical impacts to insert the graft. Consequently, there is a need to understand what factors influence the vulnerability of in situ chondrocytes to mechanical trauma. To this end, the objective of this study was to investigate how altering cell volume by different means (hydrostatic pressure, uniaxial load, and osmotic challenge with and without inhibition of regulatory volume decrease) affects the vulnerability of in situ chondrocytes to extreme mechanical forces. Using a custom experimental platform enabling testing of viable and intact murine cartilage-on-bone explants, we established a strong correlation between chondrocyte volume and vulnerability to impact injury wherein reduced volume was protective. Moreover, we found that the volume-perturbing interventions did not affect cartilage ECM mechanical properties, suggesting that their effects on chondrocyte vulnerability occurred at the cellular level. The findings of this study offer new avenues for novel strategies aimed at preventing chondrocyte loss during osteochondral grafting or to halting the progression of cell death after a joint destabilizing injury.

Surgical Trends in Articular Cartilage Injuries of the Knee, Analysis of the Truven Health MarketScan Commercial Claims Database from 2005-2014

Purpose

To evaluate trends in procedures for the treatment of chondral injuries of the knee using the MarketScan database in the hope that further work can be performed to refine the indications for chondral intervention

Methods

The MarketScan Research Database was searched using Current Procedure Terminology, 4th edition, codes to identify patients who underwent chondral procedures of the knee from 2005-2014. Combined procedures, including meniscal transplant or osteotomy, were also identified. Patients were characterized by gender, age group and year of initial procedure. A χ² test was used to evaluate differences in surgical trends between individual patient groups delineated by age and gender. The Cochran-Armitage trend test was used to identify significant differences in surgical trends yearly.

Results

Of 148,373,254 unique patients, 520,934 patients underwent a total of 599,119 procedures. Arthroscopy with debridement/shaving of articular cartilage decreased in proportion from 75% of all procedures in 2005 to 51% of all procedures in 2014 (P < .0001). Open osteochondral allograft saw the greatest change during the study period; a higher number of females than males underwent condral procedures (P < .0001). Patients aged 45-54 underwent the most procedures (32.9% of all procedures). A total of 483 patients underwent chondral procedures in conjunction with meniscal transplant with variable incidence during the study period. A total of 1,418 patients underwent chondral procedures in conjunction with osteotomy; cumulative incidence decreased from 4.5 procedures per 1,000,000 patients/year in 2005 to 2.6 procedures per 1,000,000 patients/year in 2014 (P < .0001).

Conclusions

Knee arthroscopy with debridement/shaving of articular cartilage remains the most common procedure performed. Although open allograft and autograft transplantation saw a sustained increase in incidence, the overall incidence of cartilage procedures, as well as those performed with osteotomies, declined.

Level of Evidence

Level IV, cross-sectional study.

Clinical Outcomes of Revision Osteochondral Allograft Transplantation

PURPOSE

To assess the survivorship, clinical outcomes, and radiographic outcomes of patients who have undergone revision osteochondral allograft (OCA) to the knee in a retrospective case series.

METHODS

Nine patients who underwent revision OCA by the senior author between January 2003 and December 2015 with a minimum follow up of 2 years were reviewed retrospectively. Patients completed patient-reported outcome surveys containing the visual analog scale, the International Knee Documentation Committee, the Knee injury and Osteoarthritis Outcome Score, Lysholm score, and the Short-Form 12. Radiographic analysis included anteroposterior view graded via the Kellgren and Lawrence scale. Complications and reoperations were analyzed, with failure defined as conversion to arthroplasty. (Institutional review board 15050301.) RESULTS: One of 10 consecutive patients was lost to follow up, for an overall follow-up rate of 90% (5 males, 4 females); mean follow up, 4.53 ± 3.17 years. The median patient age at the time of revision OCA was 33 years (interquartile range [IQR], 8.6), the median defect size was 4.0 cm² (IQR, 0), and the median time from index OCA to revision OCA was 2.9 years (IQR, 1.9). Five patients (50%) underwent subsequent surgery at a median of 1.92 years (IQR, 7.25), with 1 progressing to arthroplasty at 23 months after revision OCA, for an overall failure rate of 11%. There were no significant differences in any of the patient-reported outcome assessments compared with prerevision OCA (postindex OCA) values at final follow up (P > .05 for all). Similarly, there were no significant differences in Kellgren and Lawrence score before and after surgery (P = .1).

CONCLUSIONS

At a mean 4.5 years following revision OCA, there was an 89% graft survivorship rate in a series of 9 patients, with no statistical changes in the radiographic progression of arthritis.

LEVEL OF EVIDENCE

Level IV, case series.

Should We Question the External Validity of Database Studies? A Comparative Analysis of Demographics

PURPOSE

To define the external validity of national and institutional databases for common sports medicine procedures.

METHODS

Patient demographic data including age, sex, body mass index (BMI), and 4 racial categories were aggregated between 2007 and 2016 across 2 databases for 4 common sports medicine procedures: anterior cruciate ligament reconstruction, arthroscopic rotator cuff repair (RCR), partial meniscectomy (PMx), and both arthroscopic and open shoulder stabilization. The first database of interest was a prospectively collected institutional database. The second was the National Surgical Quality Improvement Program (NSQIP) database. Two-sample t tests were performed to examine mean differences (MDs) in age and BMI, and χ² testing was used to test differences in sex and race.

RESULTS

A total of 7,019 institutional and 108,881 NSQIP patients were examined. The NSQIP cohort was significantly older (MD, 1.40 years), included more female patients (42.60% female patients vs 35.67% female patients), and showed a different racial distribution compared with the institutional data (all P < .0001). The NSQIP PMx cohort (MD, 7.38 years) was significantly older and the NSQIP RCR cohort (MD, 1.97 years) was significantly younger than their institutional counterparts (all P < .0001). The NSQIP anterior cruciate ligament reconstruction cohort (MD, 2.53) showed a greater average BMI (P < .0001). The NSQIP RCR cohort (41.8% female patients vs 33.3% female patients) and PMx cohort (46.0% female patients vs 37.9% female patients) also included more female patients. Race was distributed variably between databases for each procedure code (all P < .0001).

CONCLUSIONS

Significant differences in age, BMI, sex, and race distributions were observed between an institutional database and the NSQIP database. This study underlines the importance of defining the generalizability of database research, particularly when significant demographic differences between databases may underlie differences in postoperative outcomes.

LEVEL OF EVIDENCE

Level III, cross-sectional study.

Trends in the surgical treatment of pathological proximal femur fractures in the United States

BACKGROUND AND OBJECTIVES

Large scale data on the treatment of pathologic proximal femur fractures (PPFFs) are lacking. The purpose of this study was to evaluate trends in patient demographics, complication rates, and relative utilization rates of various techniques associated with PPFFs.

METHODS

The American College of Surgeons-National Surgical Quality Improvement Program (NSQIP) database was queried for PPFFs from 2009 to 2017. Patient demographics, 30-day complications, and utilization rates were recorded. Trends in these variables were determined over the study period.

RESULTS

Most patient demographics did not change during the study period. There were no trends toward decreasing rates of major complications (P = .82), reoperations (P = .65), non-home discharges (P = .17), readmissions (P = .07), or deaths (P = .75); transfusion rates significantly decreased (P < .001). Rates of hemiarthroplasty decreased (P = .03) and rates of intramedullary nailing increased (P = .001).

DISCUSSION

Despite advances in cancer therapeutics, the average PPFF patient has not significantly changed over the past decade. Similarly, most short-term outcomes after PPFF surgery have not improved, demonstrating a need for improved perioperative protocols. Finally, rates of IMN fixation are increasing while rates of HA are falling at NSQIP hospitals. Given that orthopedic oncologists favor endoprosthetic reconstruction in most cases, there may be a need for increased communication between orthopedic oncologists and other members of the orthopedic community treating PPFFs.

Editorial Commentary: When Performing Cartilage Restoration, Please Don't Put Down the Osteotomy Saw!

Cartilage restoration procedures appear to be increasing in popularity and are being performed more frequently for older patients according to a recent analysis of database data. Chondroplasty and microfracture are most commonly performed; however, chondrocyte transfer procedures, including osteochondral autologous transplantation and autologous chondrocyte implantation, are being performed more commonly. Relatively few corrective osteotomies are being performed in conjunction with these procedures; this is concerning because surgeons are either not looking for malalignment or not correcting it. Please, when performing joint preservation surgery, don't put down the saw!