Failure of Bone Marrow Stimulation Techniques

3D Bioprinting of Hyaline Cartilage Using Nasal Chondrocytes

Due to the limited self-repair capacity of the hyaline cartilage, the repair of cartilage remains an unsolved clinical problem. Tissue engineering strategy with 3D bioprinting technique has emerged a new insight by providing patient's personalized cartilage grafts using autologous cells for hyaline cartilage repair and regeneration. In this review, we first summarized the intrinsic property of hyaline cartilage in both maxillofacial and orthopedic regions to establish the requirement for 3D bioprinting cartilage tissue. We then reviewed the literature and provided opinion pieces on the selection of bioprinters, bioink materials, and cell sources. This review aims to identify the current challenges for hyaline cartilage bioprinting and the directions for future clinical development in bioprinted hyaline cartilage.

Subchondral bone: An emerging target for the treatment of articular surface lesions of the knee

Purpose

When dealing with the health status of the knee articular surface, the entire osteochondral unit has gained increasing attention, and in particular the subchondral bone, which plays a key role in the integrity of the osteochondral unit. The aim of this article was to discuss the current evidence on the role of the subchondral bone.

Methods

Experts from different geographical regions were involved in performing a review on highly discussed topics about the subchondral bone, ranging from its etiopathogenetic role in joint degeneration processes to its prognostic role in chondral and osteochondral defects, up to treatment strategies to address both the subchondral bone and the articular surface.

Discussion

Subchondral bone has a central role both from an aetiologic point of view and as a diagnostic tool, and its status was found to be relevant also as a prognostic factor in the follow-up of chondral treatment. Finally, the recognition of its importance in the natural history of these lesions led to consider subchondral bone as a treatment target, with the development of osteochondral scaffolds and procedures to specifically address osteochondral lesions.

Conclusion

Subchondral bone plays a central role in articular surface lesions from different points of view. Several aspects still need to be understood, but a growing interest in subchondral bone is to be expected in the upcoming future towards the optimization of joint preservation strategies.

Level of Evidence

Level V, expert opinion.

Rehabilitation of Soccer Players' Knee Injuries: Cartilage Reconstruction, Anterior Cruciate Ligament Surgery, and Intensive Recovery-A Pilot Study

Knee injuries, particularly anterior cruciate ligament (ACL) damage and cartilage defects, are highly prevalent among athletes and affect their sports performance and long-term joint function. The purpose of this research was to evaluate the effectiveness of a comprehensive combination therapy approach for individuals with ACL and cartilage injuries. Twelve professional soccer players aged 18 to 30 years underwent bone-tendon-bone ACL reconstruction, microfracture cartilage repair surgery, and hyaluronic acid scaffold treatment. Early postoperative rehabilitation included immediate supervised physiotherapy and complete weight bearing. Follow-up assessments involved clinical evaluations, functional joint assessments, and magnetic resonance imaging (MRI) scans to measure cartilage defect repair and symptom alleviation. The results showed that patients resumed pain-free activities within 3-4 weeks and returned to their pre-injury level within 4.5 months. MRI demonstrated the absence of inflammatory reactions, repair of marrow edema, and the emergence of new cartilage. Six months and one year after surgery, the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Short Form (36) Health Survey (SF-36) questionnaire results demonstrated considerable improvement in patients' health condition and quality of life. Overall, the study suggests that the combination of Hyalofast membranes, microfracture surgery, tissue adhesive, and intensive postoperative physical therapy may be a potential alternative to commonly used treatments for patients with ACL rupture, allowing them to recover efficiently and return to sports activities.

O-alg-THAM/gel hydrogels functionalized with engineered microspheres based on mesenchymal stem cell secretion recruit endogenous stem cells for cartilage repair

Lacking self-repair abilities, injuries to articular cartilage can lead to cartilage degeneration and ultimately result in osteoarthritis. Tissue engineering based on functional bioactive scaffolds are emerging as promising approaches for articular cartilage regeneration and repair. Although the use of cell-laden scaffolds prior to implantation can regenerate and repair cartilage lesions to some extent, these approaches are still restricted by limited cell sources, excessive costs, risks of disease transmission and complex manufacturing practices. Acellular approaches through the recruitment of endogenous cells offer great promise for in situ articular cartilage regeneration. In this study, we propose an endogenous stem cell recruitment strategy for cartilage repair. Based on an injectable, adhesive and self-healable o-alg-THAM/gel hydrogel system as scaffolds and a biophysio-enhanced bioactive microspheres engineered based on hBMSCs secretion during chondrogenic differentiation as bioactive supplement, the as proposed functional material effectively and specifically recruit endogenous stem cells for cartilage repair, providing new insights into in situ articular cartilage regeneration.

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.].

Decellularized Avian Cartilage, a Promising Alternative for Human Cartilage Tissue Regeneration

Articular cartilage defects, and subsequent degeneration, are prevalent and account for the poor quality of life of most elderly persons; they are also one of the main predisposing factors to osteoarthritis. Articular cartilage is an avascular tissue and, thus, has limited capacity for healing and self-repair. Damage to the articular cartilage by trauma or pathological causes is irreversible. Many approaches to repair cartilage have been attempted with some potential; however, there is no consensus on any ideal therapy. Tissue engineering holds promise as an approach to regenerate damaged cartilage. Since cell adhesion is a critical step in tissue engineering, providing a 3D microenvironment that recapitulates the cartilage tissue is vital to inducing cartilage regeneration. Decellularized materials have emerged as promising scaffolds for tissue engineering, since this procedure produces scaffolds from native tissues that possess structural and chemical natures that are mimetic of the extracellular matrix (ECM) of the native tissue. In this work, we present, for the first time, a study of decellularized scaffolds, produced from avian articular cartilage (extracted from Gallus Gallus domesticus), reseeded with human chondrocytes, and we demonstrate for the first time that human chondrocytes survived, proliferated and interacted with the scaffolds. Morphological studies of the decellularized scaffolds revealed an interconnected, porous architecture, ideal for cell growth. Mechanical characterization showed that the decellularized scaffolds registered stiffness comparable to the native cartilage tissues. Cell growth inhibition and immunocytochemical analyses showed that the decellularized scaffolds are suitable for cartilage regeneration.

Systematic Review and Meta-Analysis of the Clinical Evidence on the Use of Autologous Matrix-Induced Chondrogenesis in the Knee

OBJECTIVE

A systematic review and meta-analysis of Autologous Matrix-Induced Chondrogenesis (AMIC®) outcomes for grade III/IV chondral and osteochondral lesions of the knee treated with Chondro-Gide®.

DESIGN

Studies with a minimum follow-up of 1 year providing clinical results of AMIC repair in the knee were included based on PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Methodological quality was assessed by the modified Coleman Methodology Score (mCMS). The meta-analysis was comparing pain VAS (Visual Analog Scale), Lysholm score, and IKDC score (International Knee Documentation Committee) between baseline and follow-up after 1 or 2 years and after >3 years.

RESULTS

Twelve studies (375 patients) were included. The mCMS demonstrated a suboptimal study design (ranking between 52 and 80). The mean age was 36.2 years (14-70 years). The mean defect size was 4.24 cm² (0.8-22 cm²). The results from the random effects model indicated a clinically significant (P < 0.05) improvement of pain VAS from baseline to follow-up at year 1 to 2 of -4.02(confidence interval -4.37; -3.67), still significant after 3 years. Lysholm score at year 1 or 2 improved significantly and remained highly significant after 3 years. IKDC score showed highly significant improvement of 32.61 between 1 and 2 years versus baseline values maintained after 3 years.

CONCLUSIONS

The AMIC procedure significantly improved the clinical status and functional scoring versus preoperative values. Evidence was obtained in a non-selected patient population, corresponding to real-life treatment of knee chondral and osteochondral defects. The evidence is sufficient to recommend AMIC in this indication.

Long-term Patient-Reported Outcome Measures Following Particulated Juvenile Allograft Cartilage Implantation for Treatment of Difficult Osteochondral Lesions of the Talus

BACKGROUND

Conventional methods are not suitable for difficult to treat osteochondral lesions of the talus (OCLTs). The role of particulated juvenile allograft articular cartilage implantation is not well elucidated for long-term patient outcomes.

METHODS

Thirteen patients with difficult-to-treat OCLTs underwent arthroscopy-assisted implantation of particulated juvenile articular cartilage graft into defects from 2010 to 2012 by the same surgeon. "Difficult to treat" was defined as having at least 3 of the following features or 2 if both variables described lesion characteristics: (1) lesions size of 107 mm² or greater, (2) shoulder lesions, (3) patients who failed microfracture, (4) patient aged ≥40 years, or (5) patient body mass index (BMI) >25. Patients were evaluated using physical examination, patient interviews, and outcome score measures. Patients had follow-up at 2 years, 4 years, and between 6 and 10 years at their most recent follow-up. Differences in functional outcome scores were compared before and after surgery.

RESULTS

Patients (age: 46.5 ± 11.8 years, BMI: 28.5 ± 6.1) had, on average, most recent follow-up of 8.0 years (range 72-113 months). Average visual analog scale for pain score decreased for patients by 3.9 points (95% confidence interval [CI] 2.18-5.60), when compared to preoperative assessment. Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports subscale scores also improved from 46.5 to 80.9 (95% CI 21.35-47.43), and from 18.8 to 57.9 (95% CI 21.05-57.10), respectively. Short Form-36 Health Survey physical component scores showed significant improvement by an average of 45.5 points (95% CI 32.42-58.50). American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale scores improved from 55.2 to 80.3 (95% CI 12.459-37.741).

CONCLUSION

These results demonstrate positive patient-reported long-term outcomes for a cohort of patients with difficult OCLTs, followed over the course of 6-10 years after treatment with arthroscopy-assisted particulated juvenile articular cartilage implantation.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Engineering large, anatomically shaped osteochondral constructs with robust interfacial shear properties

Despite the prevalence of large (>5 cm²) articular cartilage defects involving underlying bone, current tissue-engineered therapies only address small defects. Tissue-engineered, anatomically shaped, native-like implants may address the need for off-the-shelf, tissue-repairing therapies for large cartilage lesions. This study fabricated an osteochondral construct of translationally relevant geometry with robust functional properties. Scaffold-free, self-assembled neocartilage served as the chondral phase, and porous hydroxyapatite served as the osseous phase of the osteochondral constructs. Constructs in the shape and size of an ovine femoral condyle (31 × 14 mm) were assembled at day 4 (early) or day 10 (late) of neocartilage maturation. Early osteochondral assembly increased the interfacial interdigitation depth by 244%, interdigitation frequency by 438%, interfacial shear modulus by 243-fold, and ultimate interfacial shear strength by 4.9-fold, compared to late assembly. Toward the development of a bioprosthesis for the repair of cartilage lesions encompassing up to an entire condylar surface, this study generated a large, anatomically shaped osteochondral construct with robust interfacial mechanical properties and native-like neocartilage interdigitation.

Clinically Significant Outcomes Following the Treatment of Focal Cartilage Defects of the Knee With Microfracture Augmentation Using Cartilage Allograft Extracellular Matrix: A Multicenter Prospective Study

PURPOSE

To determine the short-term outcomes following microfracture augmented with cartilage allograft extracellular matrix for the treatment of symptomatic focal cartilage defects of the adult knee.

METHODS

Forty-eight patients enrolled by 8 surgeons from 8 separate institutions were included in this study. Patients underwent microfracture augmented by cartilage allograft extracellular matrix (BioCartilage; Arthrex, Naples, FL) and were followed at designated time points (3, 6, 12, and 24 months) to assess patient-reported outcomes (PROs), clinically significant outcomes (CSOs), and failure and complication rates. Magnetic resonance imaging (MRI) was offered at 2 years postoperatively regardless of symptomatology, and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score was documented.

RESULTS

PRO compliance was 81.3% at 6 months, 72.9% at 12 months, and 47.9% at 2 years. All joint-specific and function-related PROs significantly improved compared to baseline at 3, 6, 12, 18, and 24 months of follow-up (P < .01), apart from Marx activity scale, which demonstrated a significant decline in postoperative scores at 2 years (P = .034). The percentage of patients achieving CSOs (as defined for microfracture) at 2 years was 90% for minimal clinically important difference and 85% for patient acceptable symptomatic state. Patient factors including age, sex, body mass index, symptoms duration, smoking, presence of a meniscal tear, lesion size, and location were not associated with CSO achievement at 2 years. One patient (2.1%) failed treatment 9.5 months postoperatively due to graft delamination and required a reoperation consisting of arthroscopic debridement. One complication (2.1%) consisting of complaints of clicking, grinding, and crepitus 15 months following the index procedure was reported. Two-year postoperative MRI demonstrated a mean 40.5 ± 22.9 MOCART 2.0 score.

CONCLUSIONS

In this preliminary study, we found cartilage allograft extracellular matrix to be associated with improvement in functional outcomes, high rates of CSO achievement, and low failure and complication rates at 2-year follow-up.

LEVEL OF EVIDENCE

Level III, prospective multicenter cohort study.

Treatment of Unicompartmental Cartilage Defects of the Knee with Unicompartmental Knee Arthroplasty, Patellofemoral Partial Knee Arthroplasty or Focal Resurfacing

Focal chondral defects are common lesions of the articular cartilage. They are predominantly found on the medial femoral condyle and often progress to osteoarthritis of the knee. Various conservative treatment options are available. The conservative treatment might reduce pain and delay the progress of degenerative processes. However, restoration of the articular cartilage cannot be accomplished. If the conservative treatment fails unicompartmental arthroplasty, patellofemoral joint replacement or focal resurfacing are reasonable options to postpone total knee arthroplasty. A careful patient selection before surgery is crucial for all three treatment options. The following overview reports indications and outcomes of medial partial knee replacement, patellofemoral partial knee replacement, and focal resurfacing treatment options for focal chondral defects.

Osteochondritis dissecans of the glenoid: an analysis of grades, treatment, and outcomes

Background

Osteochondritis dissecans (OCD) is an idiopathic disorder of subchondral bone that causes focal articular cartilage disruption with the potential long-term consequence of premature osteoarthritis. Glenoid OCD is exceedingly rare. This case series aims to identify the grades of glenoid OCD and report its grade-specific treatment with clinical, radiological, and functional outcomes.

Methods

Prospectively collected data of consecutive patients diagnosed with a symptomatic glenoid OCD, who had a minimum 2-year follow-up, following nonoperative or surgical treatment, was retrospectively analyzed. Osteochondral defects secondary to acute trauma, instability, and primary osteoarthritis were excluded. Pretreatment and posttreatment clinical, radiological, and sports participation data were collected. This included pretreatment MRI for grading of glenoid OCD according to the International Cartilage Research Society (ICRS) OCD staging system, and postoperative MRI for grading of articular cartilage repair using the MOCART (MRI observation of cartilage repair tissue) scoring system.

Results

The study identified 7 competitive overhead athletes with symptomatic unilateral glenoid OCD, with a post-treatment minimum 2-year follow-up. Of 4 patients with ICRS OCD I, 3 healed with nonoperative treatment, whereas 1 progressed to ICRS OCD II. This patient along with another 3 patients with unstable glenoid OCD underwent arthroscopic OCD excision with bone marrow stimulation cartilage repair. All patients improved following treatment and had full passive and active range of shoulder movements, with normal strength and stability at the 2- year follow-up. The mean MOCART score on MRI at 2 years for the 4 patients who underwent surgery was 82.5 (range, 75-90). MRI documented healing in all 3 patients with ICRS OCD I who underwent nonoperative treatment. All patients returned to the same or higher level of sport following treatment, with mean time to return to sports being 8.0 months (range, 6-11 months) for nonoperative treatment, and 6.8 months (range, 5-10 months) for operative treatment. This difference was not statistically significant (P value .55). No patient had recurrence of symptoms till latest follow-up.

Conclusion

Despite the glenoid being a concave non–weight-bearing articular surface, OCD at this site has pathological grades similar to other convex weight-bearing articular surfaces. Notwithstanding the limited number of cases, it would appear that ICRS OCD I can often be successfully treated with nonoperative treatment, whereas ICRS OCD II, III, IV, warrant operative treatment. Bone marrow stimulation is a safe and predictable option for glenoid OCD cartilage repair and allows athletes a quick and successful return to sports.

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.

Management of bilateral osteochondritis dissecans of the trochlea in a skeletally immature patient

Osteochondritis dissecans (OCD) lesions are injuries that occur more commonly in the skeletally immature population. In most cases, the aetiology is not well understood, but fortunately, many OCD lesions may heal on their own over time, particularly in skeletally immature patients with open physes. Conversely, if the lesion is considered unstable, surgical intervention may be required. This case demonstrates an especially rare presentation of bilateral OCD lesions within the lateral femoral trochlear facet. The lesions became symptomatic approximately 1 year apart without a specific injury. Non-operative treatment was not recommended in either case due to the size and instability of each lesion. The surgical treatment used an augmented microfracture technique. At 12 and 23 months after surgery, both knees remain asymptomatic and the patient has returned to their desired activities.

Extracellular matrix derived from allogenic decellularized bone marrow mesenchymal stem cell sheets for the reconstruction of osteochondral defects in rabbits

Bioactive scaffolds from synthetical polymers or decellularized cartilage matrices have been widely used in osteochondral regeneration. However, the risks of potential immunological reactions and the inevitable donor morbidity of these scaffolds have limited their practical applications. To address these issues, a biological extracellular matrix (ECM) scaffold derived from allogenic decellularized bone marrow mesenchymal stem cell (BMSC) sheets was established for osteochondral reconstruction. BMSCs were induced to form cell sheets. Three different concentrations of sodium dodecyl sulfate (SDS), namely, 0.5%, 1%, and 3%, were used to decellularize these BMSC sheets to prepare the ECM. Histological and microstructural observations were performed in vitro and then the ECM scaffolds were implanted into osteochondral defects in rabbits to evaluate the repair effect in vivo. Treatment with 0.5% SDS not only efficiently removed BMSCs but also successfully preserved the original structure and bioactive components of the ECM When compared with the 1% and 3% SDS groups, histological observations substantiated the superior repair effect of osteochondral defects, including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular cartilage integrated with native tissues in the 0.5% SDS group. Moreover, RT-PCR indicated that ECM scaffolds could promote the osteogenic differentiation potential of BMSCs under osteogenic conditions while increasing the chondrogenic differentiation potential of BMSCs under chondrogenic conditions. Allogenic BMSC sheets decellularized with 0.5% SDS treatment increased the recruitment of BMSCs and significantly improved the regeneration of osteochondral defects in rabbits, thus providing a prospective approach for both articular cartilage and subchondral bone reconstruction with cell-free transplantation.

Survivorship of Patellofemoral Osteochondral Allograft Transplantation

Introduction

We performed a survivorship analysis of patients treated with patellofemoral osteochondral allograft transplantation (OCA) using either a shell or plug technique and identified variables associated with graft failure.

Methods

Consecutive patients at two institutions who underwent OCA of the patellofemoral compartment between March 1, 2001 to March 1, 2015, were retrospectively identified at minimum 2 years' follow-up. Demographic information, intraoperative findings, and postoperative data were collected. Patients were divided into two groups on the basis of surgical technique (plug group and shell group). Failure was defined as revision OCA, conversion to arthroplasty, or gross appearance of graft degeneration on second-look arthroscopy. Logistic regression analysis was performed to identify patient- and surgery-specific variables associated with survivorship.

Results

Fifty patients were identified (36 women and 14 men; mean age 37.43 ± 8.87 years). Sixteen patients received plug allografts, whereas 34 received shell allografts. Forty percent of patients underwent a concomitant meniscal, ligamentous, malalignment, or chondral procedure. Five patients in the Plug Group (31.3%) underwent reoperation at a mean 1.37 ± 1.34 years, and 28 patients (82.4%) who received Shell OCA underwent reoperation at a mean 1.94 ± 1.92 years. Two patients in the plug group had graft failure at a mean 9.17 ± 0.93 years, whereas 13 patients in the shell group had graft failure at a mean 3.81 ± 2.78 years. Patients with plug allografts demonstrated 100% and 66% survival at 5 and 9.8 years, respectively. For the shell group, survivorship was 65.8% and 37% at 5 and 10.6 years, respectively. Increasing body mass index was associated with failure for the case series overall (odds ratio 1.33, P = .020). Traumatic cause was found to be protective of failure (odds ratio = 0.02, P = .035).

Conclusions

Plug OCA of the patellofemoral compartment can be an efficacious procedure with quality mid-term outcomes. Shell OCA led to high failure rates at midterm outcomes. Increasing body mass index may predispose patients to failure, whereas traumatic cause of their lesion was associated with improved outcomes.

Level of Evidence

Level IV, Therapeutic case series.

Cartilage Restoration Surgery: Incidence Rates, Complications, and Trends as Reported by the American Board of Orthopaedic Surgery Part II Candidates

PURPOSE

To evaluate the current status of advanced cartilage restoration procedures among newly trained orthopaedic surgeons in the United States.

METHODS

The American Board of Orthopaedic Surgery database was queried to identify all advanced cartilage restoration procedure cases submitted by American Board of Orthopaedic Surgery part II board certification examination candidates from 2003 to 2015. All documented autologous chondrocyte implantation, autologous osteochondral transfer, osteochondral allograft transplantation, and marrow stimulation techniques (MSTs) procedures were analyzed. Analysis was performed to describe trends in annual incidence, types of complications, concomitant procedures, and geographical differences in incidence of advanced cartilage procedures.

RESULTS

From 2003 to 2015, a total of 2,827 surgeons submitted 7,522 cartilage restoration procedures, with 7,060 cases documented as MST (80.01%). The number of cartilage cases decreased significantly from 2003 to in 2015 (P <.001), with MST having the largest decline (P < .001). The incidence of open osteochondral allograft transplantation (odds ratio = 1.35; P = .023) and open autologous osteochondral transfer (odds ratio = 0.84; P = .004) increased over the study period. Overall, the majority of patients (57.0%) were male; however, female patients were on average significantly older than male patients (P < .001). Cartilage procedures were performed concomitantly with a realignment osteotomy procedure in 1.7% of cases. The incidence of surgical complications increased throughout the study period from 2.9% in 2003 to 9.5% in 2015 (P < .001).

CONCLUSIONS

Cartilage restoration procedures, specifically MSTs, are being decreasingly performed among recently trained orthopaedic surgeons. In contrast, complication rates have been increasing since 2003, demonstrating a possible paradigm shift toward more complex cartilage procedures, specifically osteochondral grafting procedures.

CLINICAL RELEVANCE

This study demonstrates a significant decline in the use of MSTs by recently trained orthopaedic surgeons. In addition, an increase in several more complex cartilage restoration procedures was found. Taken in sum, these changes may reflect a shift in residency and fellowship training away from marrow stimulation procedures that elicit a fibrocartilage reparative tissue and toward more complex procedures that provide a more hyaline-like articular cartilage surface.

Clinical and MRI Outcomes of Fresh Osteochondral Allograft Transplantation After Failed Cartilage Repair Surgery in the Knee

BACKGROUND

Fresh osteochondral allograft transplantation is an appealing option to address a failed cartilage repair surgical procedure, given the ability to treat large lesions and to address the subchondral osseous changes commonly seen in the revision setting. We hypothesized that osteochondral allograft transplantation after failed cartilage repair would result in low failure rates and improved function and that improved graft incorporation on postoperative magnetic resonance imaging (MRI) would correlate with a superior clinical outcome.

METHODS

A retrospective review of prospectively collected data was used to identify 43 patients treated with fresh osteochondral allograft transplantation after a previous cartilage repair surgical procedure and having a minimum follow-up of 2 years. Clinical outcomes were evaluated using the Short Form-36 (SF-36) score, International Knee Documentation Committee (IKDC) Subjective Knee Score, Marx Activity Scale, Knee Outcome Survey-Activities of Daily Living (KOS-ADL) Questionnaire, Cincinnati Sports Activity Score, and Cincinnati Overall Symptom Assessment. Postoperative MRI scans were obtained at a mean time of 19.7 months and were independently reviewed by a musculoskeletal radiologist using the Osteochondral Allograft MRI Scoring System (OCAMRISS).

RESULTS

At a mean 3.5-year follow-up after osteochondral allograft transplantation, significant improvements (p < 0.05) in SF-36 Physical Function, SF-36 Pain, KOS-ADL, IKDC Subjective Knee Score, and Cincinnati Overall Symptom Assessment were seen. Over 90% of grafts remained in situ at the time of the latest follow-up, although 17 knees (40%) underwent reoperation, the majority for arthroscopic debridement or manipulation for stiffness. Body mass index (BMI) of >30 kg/m was associated with worse clinical outcomes. The mean total OCAMRISS score demonstrated poorer allograft integration in patients with graft failure, but the total score did not meaningfully correlate with clinical outcome scores. However, better individual articular cartilage appearance and osseous integration subscores were associated with better clinical outcome scores.

CONCLUSIONS

Significant improvements in pain and function were seen following fresh osteochondral allograft transplantation after failed cartilage repair, with an overall graft survival rate of >90%. Patients with greater bone and cartilage incorporation on MRI had superior clinical outcomes, although persistent osseous edema was frequently seen. We concluded that osteochondral allograft transplantation is an effective salvage treatment after failed cartilage repair and recommend further evaluation of techniques to optimize graft integration.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Do Focal Chondral Defects of the Knee Increase the Risk for Progression to Osteoarthritis? A Review of the Literature

Background:

Focal chondral defects (FCDs) of the knee are believed to contribute to the development of osteoarthritis (OA), resulting in pain and dysfunction.

Purpose:

To investigate whether untreated FCDs of the knee progress to radiographically evident OA over time.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A literature review was performed by searching the PubMed, Embase, and Cochrane Library databases to locate studies evaluating clinical and/or radiological outcomes of patients with FCDs that were diagnosed by arthroscopic surgery or magnetic resonance imaging (MRI) and were left untreated with a minimum 2-year follow-up. Additionally, studies were included if there was a radiographic assessment of OA. Search terms used were “knee,” “focal,” “isolated,” “chondral,” “cartilage,” and “osteoarthritis.” Studies were evaluated based on clinical/radiological outcomes and OA risk factors. The study methodology was assessed using the modified Coleman Methodology Score.

Results:

Eight studies comprising 1425 knees met the inclusion criteria. All studies were of level 3 evidence. The risk of incident cartilage damage (enlargement of original FCDs or incidence of additional FCDs) at latest follow-up was assessed in 3 studies, while 1 study only reported the incidence of cartilage damage at follow-up. All 4 studies noted an increased progression of cartilage damage at follow-up. The progression of cartilage damage was most commonly seen in the patellofemoral joint and medial femoral condyle but was not associated with the development of knee OA based on the Kellgren-Lawrence grade. MRI of the FCDs revealed increased water content, cartilage deterioration, and proteoglycan loss within the medial and lateral compartments.

Conclusion:

Patients with untreated FCDs of the knee joint are more likely to experience a progression of cartilage damage, although the studies included in this review did not demonstrate the development of radiographically evident OA within 2 years of follow-up.

Clinical Outcomes of Multifocal Osteochondral Allograft Transplantation of the Knee: An Analysis of Overlapping Grafts and Multifocal Lesions

BACKGROUND

There is a paucity of literature regarding the outcomes of adjacent-plug osteochondral allograft transplantation (OCA) for irregular or ovoid lesions and multifocal OCA for multicompartmental, focal lesions.

PURPOSE

To quantify the survival of multiplug OCA for larger, high-grade chondral lesions with the "snowman" technique versus that of multicompartmental or bipolar OCA.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All patients who underwent primary, multiplug OCA for large unicondylar, multicompartmental (eg, bipolar patellofemoral and condylar, bicondylar), or bipolar chondral defects (ie, patellofemoral) with a minimum 2-year follow-up by a single surgeon from April 1, 2003, to April 1, 2015, were analyzed. Failure was defined as revision OCA, conversion to arthroplasty, or gross appearance of graft degeneration on second-look arthroscopic surgery.

RESULTS

Twenty-six patients (28 knees) were identified, with 22 patients (24 knees; 50% female; mean age, 31.9 ± 9.1 years) having at least 2-year clinical follow-up (85.7%). Nine patients (9 knees) underwent isolated, condylar OCA with the snowman technique and had a mean follow-up of 7.4 ± 3.6 years (range, 1.38-11.14 years), while 13 additional patients (15 knees) underwent multifocal OCA and had a mean follow-up of 6.4 ± 3.9 years (range, 2.07-12.38 years). Reoperations were common, with 44.4% (n = 4) of the snowman group and 20.0% (n = 3) of the multifocal group undergoing at least 1 reoperation. There were 3 failures (33.3%) in the snowman group at a mean 7.7 ± 5.5 years and 1 failure (6.7%) in the multifocal group at 4.5 ± 0.0 years, with all undergoing secondary total knee arthroplasty. Patients who underwent snowman OCA demonstrated significant postoperative improvement in the Knee injury and Osteoarthritis Outcome Score (KOOS) pain subscore and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) overall score ( P < .05 for both). Patients who underwent multifocal OCA demonstrated significant improvement in the International Knee Documentation Committee score; KOOS symptoms, activities of daily living, sport, and quality of life subscores; WOMAC stiffness, function, and overall subscores; and 12-Item Short Form Health Survey physical component summary score ( P < .05 for all).

CONCLUSION

Patients who underwent unicondylar, multiplug OCA using the snowman technique demonstrated inferior clinical outcomes, higher reoperation rates, and greater failure rates than those who underwent isolated single-graft transplantation. By contrast, multifocal OCA may be a viable knee preservation technique for young, active patients with multicompartmental chondral disease, leading to improved clinical outcomes and low reoperation and failure rates at midterm follow-up.

Bone Marrow Aspirate Concentrate for Cartilage Defects of the Knee: From Bench to Bedside Evidence

Objective To critically evaluate the current basic science, translational, and clinical data regarding bone marrow aspirate concentrate (BMAC) in the setting of focal cartilage defects of the knee and describe clinical indications and future research questions surrounding the clinical utility of BMAC for treatment of these lesions. Design A literature search was performed using the PubMed and Ovid MEDLINE databases for studies in English (1980-2017) using keywords, including ["bone marrow aspirate" and "cartilage"], ["mesenchymal stem cells" and "cartilage"], and ["bone marrow aspirate" and "mesenchymal stem cells" and "orthopedics"]. A total of 1832 articles were reviewed by 2 independent authors and additional literature found through scanning references of cited articles. Results BMAC has demonstrated promising results in the clinical application for repair of chondral defects as an adjuvant procedure or as an independent management technique. A subcomponent of BMAC, bone marrow derived-mesenchymal stem cells (MSCs) possess the ability to differentiate into cells important for osteogenesis and chondrogenesis. Modulation of paracrine signaling is perhaps the most important function of BM-MSCs in this setting. In an effort to increase the cellular yield, authors have shown the ability to expand BM-MSCs in culture while maintaining phenotype. Conclusions Translational studies have demonstrated good clinical efficacy of BMAC both concomitant with cartilage restoration procedures, at defined time points after surgery, and as isolated injections. Early clinical data suggests BMAC may help stimulate a more robust hyaline cartilage repair tissue response. Numerous questions remain regarding BMAC usage, including cell source, cell expansion, optimal pathology, and injection timing and quantity.

Clinical Outcomes of Osteochondral Allograft Transplantation for Secondary Treatment of Osteochondritis Dissecans of the Knee in Skeletally Mature Patients

PURPOSE

To report clinical outcomes of osteochondral allograft transplantation (OCA) for skeletally mature patients with osteochondritis dissecans (OCD) lesions of the knee in whom prior surgical intervention has failed, and to describe return-to-sport (RTS) rates and any predictive demographic or preoperative variables associated with a higher likelihood to RTS.

METHODS

Patients who underwent OCA by a single surgeon (B.J.C.) between October 1, 2002, and November 30, 2014, for a diagnosis of OCD with a minimum of 2 years' follow-up were included. Demographic, surgical history, operative, and postoperative data points including RTS were analyzed for all patients collectively, with subanalysis to identify any demographic and operative variables associated with the ability to RTS. Failure was defined as revision OCA, gross appearance of graft failure on second-look arthroscopy, or conversion to arthroplasty.

RESULTS

We identified 41 consecutive patients (43 knees), with 37 patients (39 knees, comprising 26 male and 13 female knees) available for clinical follow-up at an average of 7.29 ± 3.30 years. There was significant improvement (P < .05) in all patient-reported outcome scores, with the exception of the Short Form 12 mental subscale (P = .910). Most patients (81.6%) reported being either mostly satisfied or completely satisfied at final follow-up. Of patients self-identifying as athletes preoperatively (n = 22), 18 (81.8%) achieved RTS at an average of 14.0 ± 8.7 months. Athletes with failure to RTS had a significantly greater body mass index (RTS, 24.68 ± 3.67; no RTS, 27.82 ± 0.69; P = .005). Subsequent surgery was performed in 14 patients (35.9%), and primary OCA failed in 2 patients at an average of 6.2 ± 3.8 years.

CONCLUSIONS

OCA is a successful secondary surgical treatment for OCD of the knee in skeletally mature patients and leads to clinically meaningful improvements in patient-reported outcome scores and high patient satisfaction and RTS rates in low-level athletes at an average of 7.29 years' follow-up. Athletes with failure to RTS were found to have a significantly higher body mass index. Although reoperation may be common after OCA (35.9%), the failure rate is low (5.1%) in this series.

LEVEL OF EVIDENCE

Level IV, case series.

Long-term Clinical Outcomes After Microfracture of the Glenohumeral Joint: Average 10-Year Follow-up

BACKGROUND

Microfracture is an effective surgical treatment for full-thickness cartilage defects of the knee; however, little is known regarding long-term outcomes after microfracture in the shoulder.

PURPOSE

To present long-term clinical outcomes of patients undergoing microfracture of full-thickness articular cartilage defects of the glenohumeral joint.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Sixteen consecutive patients (17 shoulders) were retrospectively reviewed who underwent arthroscopic microfracture of the humeral head and/or glenoid surface, with or without additional procedures between 2001 and 2008 and with a minimum follow-up of 8.5 years. All patients completed pre- and postoperative surveys containing the visual analog scale, American Shoulder and Elbow Surgeons form, and Simple Shoulder Test. Complications and reoperations were analyzed. Failure was defined by biological resurfacing or conversion to arthroplasty.

RESULTS

Of the original 16 patients (17 shoulders), 13 patients (14 shoulders) were available for mean follow-up at 10.2 ± 1.8 years after microfracture (range, 8.5-15.8 years), for an overall clinical follow-up rate of 82%. The patients (6 men, 7 women) were 36.1 ± 12.9 years old at time of microfracture. The average size of humeral head defects was 5.20 cm² (range, 4.0-7.84 cm²), and the average size of glenoid defects was 1.53 cm² (range, 1.0-3.75 cm²). Four patients (4 shoulders) underwent at least 1 reoperation, and 3 were considered to have structural failures. The average time to failure was 3.7 years after microfracture (range, 0.2-9.6 years). The overall survival rate was 76.6% at 9.6 years. For these patients, there were statistically significant improvements in visual analog scale, Simple Shoulder Test, and American Shoulder and Elbow Surgeons scores as compared with preoperative values at long-term follow-up ( P < .05 for all), without any significant change from short-term (mean, 2.3 years) to long-term (mean, 10.2 years) follow-up. There was no significant difference in Single Assessment Numeric Evaluation or Short Form-12 Physical or Mental scores between short- and long-term follow-up. When compared with short-term follow-up, in which 2 patients had already failed, 1 additional patient progressed to failure at 9.6 years after the original microfracture. Two patients (2 shoulders) were considered to have clinical failure. Owing to the overall number of failures (3 structural failure and 2 clinical failure), the total long-term success rate of glenohumeral microfracture is 66.7% in the current study.

CONCLUSION

Treating full-thickness symptomatic chondral defects of the glenohumeral joint with microfracture can result in long-term improved function and reduced pain for some patients. However, in this case series, 21.4% of patients required conversion to arthroplasty <10 years after the index microfracture procedure, and 33% to 42% of patients were considered to have potential clinical failure. Additional studies with larger patient cohorts are needed.

Arthroscopic Management of Isolated Tibial Plateau Defect With Microfracture and Micronized Allogeneic Cartilage-Platelet-Rich Plasma Adjunct

Articular cartilage lesions of the tibial plateau are an uncommonly encountered clinical entity, and they have been comparatively less well studied than femoral condyle or patellofemoral defects. The management of these lesions is complicated by the challenging geometry, difficult surgical approach, and proximity to important anatomic structures, and thus, treating these lesions by previously established methods, such as osteochondral allograft transplantation or osteochondral autograft transfer, can be a technically challenging endeavor. These lesions remain readily available to undergo microfracture, and this is the preferred method of management in the senior author's practice. Although less technically difficult and less invasive than other techniques, microfracture is currently limited by concerns over the long-term durability of the method. Current research seeks to improve the quality of cartilage fill stimulated by microfracture, and adjunct techniques have become increasingly popular. In this technical report, we present a technique for arthroscopic treatment of an isolated tibial plateau defect with microfracture using a micronized allogeneic cartilage (BioCartilage; Arthrex, Naples, FL) and platelet-rich plasma adjunct.