Do fresh osteochondral allografts successfully treat femoral condyle lesions?

Graft-Recipient Anteroposterior Mismatch Does Not Affect the Midterm Clinical Outcomes of Osteochondral Allograft Transplantation of the Femoral Condyle

BACKGROUND

For the treatment of femoral condyle cartilage defects with osteochondral allograft transplantation (OCA), many surgeons have relaxed their graft-recipient size-matching criteria given the limited allograft supply. However, since the anteroposterior (AP) length is typically correlated with the radius of curvature for a given condyle, a large mismatch in graft-recipient AP length can indicate a corresponding mismatch in the radius of curvature, leading to articular incongruity after implantation.

PURPOSE

To evaluate the association between femoral condyle graft-recipient AP mismatch and clinical outcomes of OCA.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A retrospective review was conducted of patients treated with OCA for femoral condyle chondral defects from 2000 to 2015. Graft characteristics, including AP and mediolateral dimensions, were gathered from vendor-specific allograft offering documents. Patient condyle dimensions were measured on preoperative magnetic resonance imaging. Reoperations and patient responses to validated outcome measures were reviewed. Failure was defined by any partial removal/revision of the allograft or conversion to knee arthroplasty. A multivariable logistic regression model was fitted to examine the association of AP mismatch with OCA failure while adjusting for patient age and number of previous ipsilateral knee surgical procedures.

RESULTS

A total of 69 knees from 69 patients (mean age, 35.7 years; 71% male) met the inclusion criteria. Mean duration of follow-up was 4 years (range, 2-16 years). The mean absolute graft-recipient AP mismatch was 6.7 mm (range, 0-20 mm; P < .01). At final follow-up, 19 knees had failed. There was no significant difference in the mean absolute AP mismatch between failures (8.1 mm) and nonfailures (6.2 mm; P = .17). Multivariate logistic regression revealed that AP mismatch was not associated with graft failure ( P = .14). At final follow-up, significant improvements were noted in the 36-Item Short Form Health Survey, International Knee Documentation Committee subjective form, and Knee Outcome Survey-Activities of Daily Living ( P < .01 for all). Magnitude of AP mismatch was not associated with postoperative outcome scores or achievement of minimal clinically significant differences in outcome scores.

CONCLUSION

Magnitude of graft-recipient AP mismatch was not associated with midterm OCA failure rates or patient-reported outcome scores, suggesting that AP length mismatch within the limits measured here is not a contraindication for graft acceptance.

Does Anterior Cruciate Ligament Reconstruction Affect the Outcome of Osteochondral Allograft Transplantation? A Matched Cohort Study With a Mean Follow-up of 6 Years

BACKGROUND

Few studies have evaluated the influence of anterior cruciate ligament (ACL) reconstruction on the outcome of cartilage repair. Hypothesis/Purpose: The purpose was to investigate the association between ACL reconstruction and functional outcomes after osteochondral allograft (OCA) transplantation. The hypothesis was that patients treated with OCA transplantation who had a history of ACL reconstruction would have inferior clinical outcomes and lower osteochondral graft survivorship when compared with a matched group of patients undergoing OCA transplantation without a history of ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study compared 31 knees that underwent OCA transplantation with a history of ACL reconstruction (OCA and ACL group) and 62 knees treated with isolated OCA transplantation (OCA group) that had an intact ACL. Groups were matched by age, diagnosis, year of surgery, and graft size. Minimum follow-up was 2 years. Frequency and type of reoperation were assessed. Clinical failure was defined as revision OCA transplantation or conversion to arthroplasty. Subjective outcome measures included International Knee Documentation Committee scores, Knee injury and Osteoarthritis Outcome Scores, and patient satisfaction.

RESULTS

Clinical failure occurred in 3 of 31 knees (9.7%) in the OCA and ACL group and 6 of 62 knees (9.7%) in the OCA group ( P ≤ .999). Five- and 10-year survivorship of the OCA was 94.7% and 82.3% for the OCA and ACL group and 93.4% and 79.6% for OCA group, respectively ( P = .979). Mean follow-up was 6.2 ± 3.3 years among all knees with grafts in situ. Changes from preoperative to latest follow-up visit (difference scores) on all subjective outcome measures were greater in the OCA group; however, none of the difference scores were statistically significant. Satisfaction with the results of OCA transplantation was reported in 78.3% of the OCA and ACL group and 71.7% of the OCA group ( P = .551).

CONCLUSION

Treatment of cartilage lesions with OCA transplantation proved to be reliable and effective regardless of a history of ACL reconstruction as demonstrated by the improvements in outcome scores, long survivorship, and high satisfaction rates. History of ACL reconstruction did not influence outcome of OCA transplantation.

Osteochondral Allograft Transplantation and Opening Wedge Tibial Osteotomy: Clinical Results of a Combined Single Procedure

Objective To evaluate the outcome of patients who have undergone simultaneous osteotomy and osteochondral allograft (OCA) transplantation. Our hypothesis is that use of high tibial osteotomy and fresh OCA in a combined procedure is safe and effective without increasing morbidity in comparison to OCA alone. Design A case series of 17 patients underwent tibial osteotomy and simultaneous OCA during a single surgery. Osteotomy was indicated when axial alignment was within the affected compartment. Patients had a minimum of 2 years of follow-up after surgery. The mean graft size was 8.7 cm², with 82% located on the medial femoral condyle alone and 18% involving the medial femoral condyle and one or more other sites. Data collection included demographics, osteotomy correction, graft site(s) and area, and clinical evaluation. Failure was defined as conversion to arthroplasty. Results Two of 17 patients (12%) failed at a mean of 9.3 years. The remaining 15 patients (88%) had intact allografts with mean survival of 8.1 years (SD 3.3). Five patients (29%) had an additional procedure, all undergoing osteotomy hardware removal. Of those with surviving allografts, mean pain and function scores improved significantly from the preoperative to postoperative assessment and International Knee Documentation Committee total scores improved significantly from 40.9 ± 15.4 preoperative to 75.5 ± 24.0 at latest follow-up ( P = 0.003); 92% of patients were satisfied with the results of the surgery. No postoperative complications occurred. Conclusion Combining high tibial osteotomy and OCA in properly selected patients is safe and effective.

Orthopedic Surgical Options for Joint Cartilage Repair and Restoration

The limited natural capacity for articular cartilage to regenerate has led to a continuously broadening array of surgical interventions. Used once patients' symptoms are not relieved by nonoperative management, these share the goals of joint preservation and restoration. Techniques include bone marrow stimulation, whole-tissue transplantation, and cell-based strategies, each with its own variations. Many of these interventions are performed arthroscopically or with extended-portal techniques. Indications, operative techniques, unique benefits, and limitations are presented.

Effect of Bisphosphonate Pretreatment on Fresh Osteochondral Allografts: Analysis of In Vitro Graft Structure and In Vivo Osseous Incorporation

Fresh allograft transplantation of osteochondral defects restores functional articular cartilage and subchondral bone; however, rapid loss of chondrocyte viability during storage and osteoclast-mediated bone resorption at the graft-host interface after transplantation negatively impact outcomes. The authors present a pilot study evaluating the in vitro and in vivo impact of augmenting storage media with bisphosphonates. Forty cylindrical osteochondral cores were harvested from femoral condyles of human cadaveric specimens and immersed in either standard storage media or storage media supplemented with nitrogenated or non-nitrogenated bisphosphonates. Maintenance of graft structure and chondrocyte viability were assessed at 3 time points. A miniature swine trochlear defect model was used to evaluate the influence of bisphosphonate-augmented storage media on in vivo incorporation of fresh osteochondral tissue, which was quantified via μCT and decalcified histology. In the in vitro study, Safranin-O/Fast Green staining showed that both low- and high-dose nitrogenated-treated grafts retained chondrocyte viability and cartilage matrix for up to 43 days of storage. Allografts stored in nitrogenated-augmented storage media showed both μCT and histologic evidence of enhanced in vivo bony and cartilaginous incorporation in the miniature swine trochlear defect model. Several preclinical studies have shown the potential for enhanced storage of fresh osteochondral allografts via additions of relatively common drugs and biomolecules. This study showed that supplementing standard storage media with nitrogenated bisphosphonates may improve maintenance of chondrocyte viability and graft structure during cold storage as well as enhance in vivo osseous and cartilaginous incorporation of the graft. [Orthopedics: 2018; 41(3):e376-e382.].

Biological Response Following Inlay Arthroplasty of the Knee: Cartilage Flow Over the Implant

Objective Inlay arthroplasty (IA) has seen growing interest as a new primary arthroplasty intervention for patients that need to transition from biology to joint replacement. The purpose of this study was to investigate the biological response to this procedure. Design Patients presenting with symptomatic mono- or bicompartmental arthrosis and varus malalignment underwent IA and concurrent medial open wedge high tibial osteotomy (HTO). A subset of patients required hardware removal and consented to second-look arthroscopy without biopsy allowing for assessment of IA components and compartment-specific findings related to implant fixation, cartilage flow, propagation of lesions, and opposing tibial surfaces. Results In a series of 41 knees (35 patients) treated with combined IA and HTO (mean varus >7°), 26 knees (23 patients, 18 male, 5 female) with a mean age of 52 years (range = 43-67) required HTO plate removal. Concurrent second look arthroscopy was performed at a mean of 14 months (range = 12-19) following the index procedure. On probing, all arthroplasty components showed solid fixation without gap formation. On the medial femoral condyle, 15 mm implants ( n = 14) showed a peripheral cartilage flow of 12% (range = 5% to 25%), 20 mm implants ( n = 12) of 9% (range 5% to 15%), and trochlear implants ( n = 12) of 20% (range 10% to 40%). No progressive deterioration of the index defects or progression of tibial and retropatellar grades were seen. Conclusion Joint surface reconstruction using IA showed stable fixation with peripheral cartilage coverage ranging from 9% to 20% and no further chondral damage on opposing surfaces. Future clinical effectiveness studies are required to support the positive biological integration.

Does Treatment of the Tibia Matter in Bipolar Chondral Defects of the Knee? Clinical Outcomes with Greater Than 2 Years Follow-up

PURPOSE

To compare the osteochondral allograft (OCA) outcomes of bipolar defects with isolated femoral defects and to investigate the optimal treatment of bipolar defects by comparing femoral OCA with tibial debridement to femoral OCA and tibial microfracture.

METHODS

A series of patients with 2-year follow-up from March 2004 to September 2015 after femoral OCA for bipolar chondral defects was identified. Group 1 contained patients with tibial defects treated with debridement and group 2 contained patients with microfractured tibial defects. A third group (group 3) with isolated femoral defects treated with OCA was identified and matched by gender, body mass index (BMI), laterality, and OCA size to groups 1 and 2. Patient-specific, defect-specific, intraoperative, and postoperative data including patient-reported outcomes were collected on all patients. The study groups were compared using analyses of variance, paired sample t tests, and χ-square analyses.

RESULTS

Thirty-six patients who had femoral OCA for bipolar lesions were identified with 20 patients in group 1 and 16 patients in group 2. Group 3 had 20 patients. There were no differences between the 3 groups in terms of gender (P = .616), BMI (P = .271), number of previous surgeries (P = .451), femoral or tibial defect size (P = .296), and OCA size (P = .981). Preoperative to postoperative patient-reported clinical outcomes (PROs) revealed statistical and clinically meaningful improvement in all 3 groups, but did not differ between groups. Patient-specific and defect-specific factors did not correlate with PROs. The graft survivorship for group 1 was 85% at 4.5 years, 100% for group 2 at 2.5 years, and 95% for group 3 at 3.8 years.

CONCLUSIONS

Regardless of tibial treatment, patients with bipolar defects treated with femoral OCA have clinically meaningful improvements in PROs and excellent graft survivorship comparable to isolated femoral OCAs at more than 2 years.

LEVEL OF EVIDENCE

Level III, case-control study.

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.

Treatment of Failed Articular Cartilage Reconstructive Procedures of the Knee: A Systematic Review

Background

Symptomatic articular cartilage lesions of the knee are common and are being treated surgically with increasing frequency. While many studies have reported outcomes following a variety of cartilage restoration procedures, few have investigated outcomes of revision surgery after a failed attempt at cartilage repair or reconstruction.

Purpose

To investigate outcomes of revision cartilage restoration procedures for symptomatic articular cartilage lesions of the knee following a previously failed cartilage reconstructive procedure.

Study Design

Systematic review; Level of evidence, 4.

Methods

A literature search was performed by use of the PubMed, EMBASE, and MEDLINE/Ovid databases for relevant articles published between 1975 and 2017 that evaluated patients undergoing revision cartilage restoration procedure(s) and reported outcomes using validated outcome measures. For studies meeting inclusion criteria, relevant information was extracted.

Results

Ten studies met the inclusion criteria. Lesions most commonly occurred in the medial femoral condyle (MFC) (52.8%), with marrow stimulation techniques (MST) the index procedure most frequently performed (70.7%). Three studies demonstrated inferior outcomes of autologous chondrocyte implantation (ACI) following a previous failed cartilage procedure compared with primary ACI. One study comparing osteochondral allograft (OCA) transplant following failed microfracture (MFX) with primary OCA transplant demonstrated similar clinical outcomes and graft survival at midterm follow-up. No studies reported outcomes following osteochondral autograft transfer (OAT) or newer techniques.

Conclusion

This systematic review of the literature reporting outcomes following revision articular cartilage restoration procedures (most commonly involving the MFC) demonstrated a high proportion of patients who underwent prior MST. Evidence is sufficient to suggest that caution should be taken in performing ACI in the setting of prior MST, likely secondary to subchondral bone compromise. OCA appears to be a good revision treatment option even if the subchondral bone has been violated from prior surgery or fracture.

Large Osteochondral Allografts of the Knee: Surgical Technique and Indications

Large osteochondral allograft (OCA) transplant has become a valid alternative to restore articular surface in challenging articular lesions in young and active patients, either in primary or in revision procedures. Several studies support the effectiveness and safety of OCA, but costs and graft availability limit their use. The indications are the treatment of symptomatic full-thickness cartilage lesions greater than 3 cm ² , deep lesions with subchondral damage, or revision procedures when a previous treatment has failed. The goal of the transplant is to restore the articular surface with a biological implant, allow return to daily/sports activities, relieve symptoms, and delay knee arthroplasty. Grafts can be fresh, fresh-frozen, or cryopreserved; these different storage procedures significantly affect cell viability, immunogenicity, and duration of the storage. Dowel and shell technique are the two most commonly used procedures for OCA transplantation. While most cartilage lesions can be treated with the dowel technique, large and/or geometrically irregular lesions should be treated with the shell technique. OCA transplantation for the knee has demonstrated reliable mid- to long-term results in terms of graft survival and patient satisfaction. Best results are reported: in unipolar lesions, in patients younger than 30 years, in traumatic lesions and when the treatment is performed within 12 months from the onset of symptoms.

Use of mesenchymal stem cells seeded on the scaffold in articular cartilage repair

Articular cartilage has poor capacity for repair. Once damaged, they degenerate, causing functional impairment of joints. Allogeneic cartilage transplantation has been performed for functional recovery of articular cartilage. However, there is only a limited amount of articular cartilage available for transplantation. Mesenchymal stem cells (MSCs) could be potentially suitable for local implantation. MSCs can differentiate into chondrocytes. Several studies have demonstrated the therapeutic potential of MSCs in the repair of articular cartilage in animal models of articular cartilage damage and in patients with damaged articular cartilage. To boost post-implantation MSC differentiation into chondrocytes, the alternative delivery methods by scaffolds, using hyaluronic acid (HA) or poly-lactic-co-glycolic-acid (PLGA), have developed. In this review, we report recent data on the repair of articular cartilage and discuss future developments.

Osteochondral Allograft Transplantation of the Knee in Patients Aged 40 Years and Older

BACKGROUND

Treatment of large chondral defects of the knee among patients aged ≥40 years remains a difficult clinical challenge owing to preexisting joint degeneration and the lack of treatment options short of arthroplasty.

PURPOSE

To characterize the survivorship, predictors of failure, and clinical outcomes of osteochondral allograft transplantation (OCA) of the knee among patients aged ≥40 years.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Prospectively collected data were reviewed for 54 consecutive patients aged ≥40 years who were treated with OCA. Preoperative levels of osteoarthritis (according to Kellgren-Lawrence classification) and meniscal volume and quality were graded from review of radiographs and magnetic resonance imaging. Complications, reoperations, and patient responses to validated outcome measures were reviewed. A minimum follow-up of 2 years was required for analysis. Failure was defined by any removal or revision of the allograft or conversion to arthroplasty.

RESULTS

Among 51 patients (mean age, 48 years; range, 40-63 years; 65% male), a total of 52 knees had symptomatic focal cartilage lesions (up to 2 affected areas) that were classified as Outerbridge grade 4 at the time of OCA and did not involve substantial bone loss requiring shell allografts or additional bone grafting. Mean duration of follow-up was 3.6 years (range, 2-11 years). After OCA, 21 knees (40%) underwent reoperation, including 14 failures (27%) consisting of revision OCA (n = 1), unicompartmental knee arthroplasty (n = 5), and total knee arthroplasty (n = 8). Mean time to failure was 33 months, and 2- and 4-year survivorship rates were 88% and 73%, respectively. Male sex (hazard ratio = 4.18, 95% CI = 1.12-27.13) and a higher number of previous ipsilateral knee operations (hazard ratio = 1.70 per increase in 1 surgical procedure, 95% CI = 1.03-2.83) were predictors of failure. A higher Kellgren-Lawrence osteoarthritis grade on preoperative radiographs was associated with higher failure rates in the Kaplan-Meier analysis but not the multivariate model. At final follow-up, clinically significant improvements were noted in the pain (mean score, 47.8 to 67.6) and physical functioning (56.8 to 79.1) subscales of the Short Form-36, as well as the International Knee Documentation Committee subjective form (45.0 to 63.6), Knee Outcome Survey-Activities of Daily Living (64.5 to 80.1), and overall condition statement (4.5 to 6.8) ( P < .001). No significant changes were noted for the Marx Activity Rating Scale (5.1 to 3.9, P = .789).

CONCLUSION

A higher failure rate was found in this series of patients aged ≥40 years who were treated with OCA as compared with other studies of younger populations. However, for select older patients, OCA can be a good midterm treatment option for cartilage defects of the knee.

Autologous Chondrocyte Implantation "Sandwich" Technique Compared With Autologous Bone Grafting for Deep Osteochondral Lesions in the Knee

BACKGROUND

Treating symptomatic osteochondral defects is challenging, especially in young adults with deep (>8-10 mm) empty defects after osteochondritis dissecans (OCD) or collapsed condyles secondary to avascular necrosis (AVN). For this population, osteoarthritis (OA) is inevitable if articular congruence is not restored.

PURPOSE

To describe the autologous chondrocyte implantation (ACI) "sandwich" technique with autologous bone grafting (ABG) and compare it with ABG alone for restoration of the osteochondral unit. The midterm to long-term outcomes in patients after the treatment for OCD and AVN will be reported and compared.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The outcomes for a consecutive cohort of 24 patients who underwent combined ABG with the ACI sandwich technique between 2001 and 2013 (ACI sandwich group) was compared with a historical control group of 17 consecutive patients who underwent ABG alone between 1995 and 2002 (ABG group) by a single surgeon for symptomatic deep (>8 mm) osteochondral lesions. Patients who were followed up with a minimum of 2 years were included in this study. The modified Cincinnati Knee Rating System, the Western Ontario and McMaster Universities Osteoarthritis Index, a visual analog scale (VAS), the Short Form-36, and a patient satisfaction survey were used to evaluate clinical outcomes. Survival analysis was performed using the Kaplan-Meier method, with no clinical improvement, graft failure, or conversion to prosthetic arthroplasty as the endpoint (failure). Kellgren-Lawrence (K-L) grading to assess OA progression was also performed.

RESULTS

In the ABG group, 13 of 17 patients (76%) were available with a mean follow-up of 15.7 years postoperatively (range, 5-21 years). In the ACI sandwich group, all 24 patients were available with a mean follow-up of 7.8 years postoperatively (range, 2-15 years). No significant differences were observed between the groups in terms of age, sex, side of the operated knee, body mass index, lesion type, lesion size, lesion depth, lesion location, or the need for realignment osteotomy. Eight patients (62%) were considered failures in the ABG group, while 3 patients (13%) were considered failures in the ACI sandwich group. The survival rate was significantly better in the ACI sandwich group than the ABG group (87% vs 54% at 5 years, respectively; P = .0025). All functional scores in patients with retained grafts significantly improved in the ACI sandwich group, whereas only the VAS score showed significant improvement in the ABG group. The patient satisfaction survey showed a very high satisfaction rate in the ACI sandwich group, with over 90% of patients reporting their knees as good or excellent and being satisfied with the procedure. In the ACI sandwich group, K-L grading demonstrated no significant OA progression from preoperatively to a mean 5.1 years postoperatively.

CONCLUSION

Our study showed that the ACI sandwich technique provided excellent and superior survival rates compared to ABG alone and significant improvements over midterm to long-term follow-up. This unique treatment offers native joint preservation for conditions that naturally will progress to OA and eventually require prosthetic arthroplasty.

Similar Outcomes After Osteochondral Allograft Transplantation in Anterior Cruciate Ligament-Intact and -Reconstructed Knees: A Comparative Matched-Group Analysis With Minimum 2-Year Follow-Up

PURPOSE

To compare failure rates and clinical outcomes of osteochondral allograft transplantation (OCA) in anterior cruciate ligament (ACL)-intact versus ACL-reconstructed knees at midterm follow-up.

METHODS

After a priori power analysis, a prospective registry of patients treated with OCA for focal chondral lesions ≥2 cm² in size with minimum 2-year follow-up was used to match ACL-reconstructed knees with ACL-intact knees by age, sex, and primary chondral defect location. Exclusion criteria included meniscus transplantation, realignment osteotomy, or other ligamentous injury. Complications, reoperations, and patient responses to validated outcome measures were reviewed. Failure was defined by any procedure involving allograft removal/revision or conversion to arthroplasty. Kaplan-Meier analysis and multivariate Cox regression were performed to evaluate the association of ACL reconstruction (ACLR) with failure.

RESULTS

A total of 50 ACL-intact and 25 ACL-reconstructed (18 prior, 7 concomitant) OCA patients were analyzed. The mean age was 36.2 years (range, 14-62 years). Mean follow-up was 3.9 years (range, 2-14 years). Patient demographics and chondral lesion characteristics were similar between groups. ACL-reconstructed patients averaged 2.2 ± 1.9 prior surgeries on the ipsilateral knee compared with 1.4 ± 1.4 surgeries for ACL-intact patients (P = .014). Grafts used for the last ACLR included bone-patellar tendon-bone autograft, hamstring autograft, Achilles tendon allograft, and tibialis allograft (data available for only 11 of 25 patients). At final follow-up, 22% of ACL-intact and 32% of ACL-reconstructed patients had undergone reoperation. OCA survivorship was 90% and 96% at 2 years and 79% and 85% at 5 years in ACL-intact and ACL-reconstructed patients, respectively (P = .774). ACLR was not independently associated with failure. Both groups demonstrated clinically significant improvements in the Short Form-36 pain and physical functioning, International Knee Documentation Committee subjective, and Knee Outcome Survey-Activities of Daily Living scores at final follow-up (P < .001), with no significant differences in preoperative, postoperative, and change scores between groups.

CONCLUSIONS

OCA in the setting of prior or concomitant ACLR does not portend higher failure rates or compromise clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Patellofemoral Articulating Osteochondral (Kissing) Lesion Treated with Autologous Chondrocyte Implantation: A Case Report

INTRODUCTION

Autologous chondrocyte implantation (ACI) is an effective treatment for chondral defects of the knee; however, its use in kissing lesions is less well documented.

CASE REPORT

A 23-year-old female with a kissing lesion of the patellofemoral compartment on magnetic resonance imaging underwent two-stage ACI to her medial patella (20 mm × 22 mm) and medial trochlea (27 mm × 18 mm). At 1-year follow-up, the patient had returned to all activities with near-complete resolution of symptoms and substantial improvement in clinical outcome scores.

CONCLUSION

Patients with kissing lesions of the knee can be treated successfully with ACI performed to multiple sites.

Condyle-Specific Matching Does Not Improve Midterm Clinical Outcomes of Osteochondral Allograft Transplantation in the Knee

BACKGROUND

Condyle-specific matching for osteochondral allograft transplantation (OCA) pairs donor and recipient condyles in an attempt to minimize articular incongruity. While the majority of cartilage defects are located on the medial femoral condyle, lateral femoral condyles are more commonly available as a graft source. The purpose of this study was to compare the clinical outcomes of patients treated with non-orthotopic (lateral-to-medial condyle or medial-to-lateral condyle) OCA with those treated with traditional orthotopic (medial-to-medial condyle or lateral-to-lateral condyle) OCA. We hypothesized that clinical outcomes would be similar between groups at midterm follow-up.

METHODS

A retrospective review of prospectively collected data on patients treated with OCA from 2000 to 2014 was conducted. Seventy-seven patients with a full-thickness cartilage defect of a femoral condyle were treated with either orthotopic (n = 50) or non-orthotopic (n = 27) OCA. A minimum follow-up of 2 years was required for analysis. Patients in each group were matched according to sex, age, and total chondral defect size. Reoperations and patient responses to validated outcome measures were reviewed. Failure was defined as any revision cartilage procedure or conversion to knee arthroplasty.

RESULTS

The mean duration of follow-up was 4.0 years (range, 2 to 16 years). The orthotopic and non-orthotopic OCA groups were comparable in terms of demographics, the mean number of prior ipsilateral knee operations, and the percentage of concomitant procedures at baseline. Reoperation (p = 0.427) and failure (p = 0.917) rates did not differ significantly between groups. Both groups demonstrated significant increases in the Short Form-36 (SF-36) physical functioning and pain, International Knee Documentation Committee (IKDC), and Knee Outcome Survey-Activities of Daily Living (KOS-ADL) scores compared with baseline (p < 0.004). Outcome scores (baseline and postoperative) and change scores did not differ significantly between groups.

CONCLUSIONS

Clinical outcomes do not differ between patients treated with orthotopic OCA and those treated with non-orthotopic OCA, suggesting that condyle-specific matching may not be necessary.

LEVEL OF EVIDENCE

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

Effectiveness of Lavage Techniques in Removing Immunogenic Elements from Osteochondral Allografts

Objective This study aimed to compare standard saline lavage to combination saline and high-pressure carbon dioxide (CO₂) lavage in removing marrow elements from osteochondral allografts. Design Six fresh hemicondyles were obtained. Three osteochondral allograft plugs (15-mm diameter, 6-mm depth) were harvested from each hemicondyle and randomized to 1 of 3 treatment arms: A, no lavage; B, 1 L standard saline lavage; C, simultaneous saline (1 L) and 1-minute high-pressure CO₂ lavage. After hematoxylin and eosin staining, a "percentage fill" of remaining marrow elements was calculated for each overall sample and then repeated in 3 distinct compartments for each sample based on depth from surface: 1, deepest third; 2, middle third; and 3, most superficial third. Trial arms B and C were compared with 1-tailed Student t tests. Results Group A had an overall percentage fill of 51.2% ± 8.8%. While both lavage techniques decreased overall remaining marrow elements, group B yielded significantly higher percentages of remaining marrow elements than group C (28.6% ± 16.5%, 14.6% ± 8.7%, P = 0.045). On depth analysis, group A exhibited homogenous filling of trabecular space (63.0% ± 15.5%, 67.6% ± 13.7%, and 55.2% ± 10.1% in zones 1, 2, and 3, respectively). Both lavage arms equally removed marrow elements from superficial zone 3 (B, 17.4% ± 9.2%; C, 15.6% ± 12.4%, P = 0.41) and middle zone 2 (B, 30.2% ± 17.7%; C, 21.4% ± 15.5%, P = 0.18). However, group C lavage removed significantly more marrow elements in deep zone 1 than group B (29.7% ± 10.9%, 58.5% ± 25.2%, P = 0.01). Conclusion Combination saline and high-pressure CO₂ lavage more effectively clears marrow elements from osteochondral allografts than saline alone.

Multicompartmental Osteochondral Allografts of Knee and Concomitant High Tibial Osteotomy

Chondral lesions of the knee can occur secondary to limb malalignment. To address these interrelated problems, a high tibial osteotomy with concomitant osteochondral allograft transfer may be performed. It is important to address these chondral lesions as they often affect the young and active population and cause morbidity in an otherwise healthy population. Although numerous approaches for the treatment of chondral lesions have been described, long-term results demonstrating regeneration of hyaline cartilage have yet to be reported. Furthermore, larger, full-thickness cartilage defects, which can be caused by limb malalignment, have proven to be particularly challenging to treat. This Technical Note details our technique for multicompartmental osteochondral allograft transplantation with concomitant high tibial osteotomy in a patient with 2 focal cartilage lesions in the knee.

Osteochondral Allograft Transplants for Large Trochlear Defects

Focal articular cartilage injuries in the knee are common and can cause severe morbidity and reduced function. The articular cartilage is avascular and has limited ability to heal, and hence, patients with cartilage injuries have increased risk of progressing to osteoarthritis. Most of the cartilage injuries are located on the femoral condyles. Engaging focal cartilage injuries involving the trochlea are challenging because of the morbidity caused by these injuries and the limited treatment options. Osteochondral allograft transplantation is emerging as a promising treatment for full-thickness articular cartilage defects. Recent studies have reported high success rates with the use of osteochondral allografts. This article reports our technique of osteochondral allograft transplantation for the treatment of a focal full-thickness defect of the trochlea.

Can Competitive Athletes Return to High-Level Play After Osteochondral Allograft Transplantation of the Knee?

PURPOSE

To investigate functional outcomes among competitive athletes undergoing osteochondral allograft (OCA) transplantation of the knee, including rates of return to play (RTP), and factors preventing RTP.

METHODS

A retrospective review identified all competitive athletes (high school, intercollegiate, professional) undergoing isolated femoral condyle OCA from 2004 to 2013. Patient-reported outcome (PRO) questionnaires (Lysholm, International Knee Documentation Committee [IKDC], Knee Injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMasters Universities Arthritis Index [WOMAC], 12-Item Short Form Health Survey [SF-12], Tegner, and Marx) and custom RTP surveys were administered. All subsequent reoperations were documented.

RESULTS

Thirteen athletes (4 intercollegiate, 9 high-school) were identified with an average follow-up of 5.9 ± 2.5 years. Seven athletes (54%) returned to competitive sport at an average of 7.9 ± 3.5 months, 5 of whom returned to preinjury functional levels. Of the 8 athletes who either did not return to competitive sport or failed to sustain their high level of play, the most common reasons cited were graduation from high school or college (4 patients, 50%) or fear of reinjury (3 patients, 38%). All 4 patients citing graduation as the primary factor preventing return to preinjury level of competitive sport resumed recreational sport without limitations, yielding an adjusted RTP rate of 10 patients (77%) who either returned to competitive play or believed they could return if they had not graduated. At final follow-up, athletes reported significant improvements in all PRO scores except for KOOS-Sport, WOMAC-Stiffness, and SF-12 Mental subscales. There were 3 reoperations at an average of 3.8 ± 3.3 years after the index OCA. There were no instances of graft failure.

CONCLUSIONS

OCAs provide an adjusted RTP rate of 77% for high-level adolescent athletes. Social factors may be more likely than persistent pain to prevent return to sport.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Osteochondral Allograft Transplantation for Treatment of Medial Femoral Condyle Defect

Chondral lesions of the knee can affect the young, active population, thereby causing severe morbidity and a large economic burden. Although numerous approaches have been described in the literature, restoration of hyaline cartilage has yet to be shown. Specifically, larger, full-thickness cartilage defects remain a challenge. This Technical Note details our technique for biologic unicompartmental osteochondral allograft transplantation for the treatment of large femoral condyle articular cartilage defects.

How to Manage a Failed Cartilage Repair: A Systematic Literature Review

Purpose  The aims of this paper are to report the rate and risk factors for the failure of the most common cartilage repair technique, and analyze the most important factors that could influence the choice of a specific surgical treatment to revise a failed cartilage repair.

Methods  A review of the literature was performed focusing on failed cartilage repair and related treatments. Two of the authors independently screened articles. Conflicts about the inclusion of a paper was resolved by further evaluation by the senior author. Review articles, articles written in languages different from/other than English, case reports, and papers that did not evaluate the outcomes of interest were excluded. Full-text version of each included paper was obtained and relevant data were extracted and collected in a database.

Results  At the end of the screening process, 31 articles were included. Microfractures and mosaicplasty showed a nonnegligible failure rate at short- and midterm. Better results, especially in terms of time to failure or revision, were reported with the use of autologous chondrocyte implantation (ACI) and osteochondral allograft (OCA) transplantation. Regarding the treatment of failed cartilage repair, the use of OCA transplantation in patients with previous failed cartilage repair may be a safe option. The revision of failed OCA transplantation with further OCA seems to have a greater failure rate. Patients with previous failed ACI or matrix-induced autologous chondrocyte implantation (MACI) who underwent further MACI or ACI reported acceptable results. Otherwise, ACI in patients with history of previous subchondral marrow stimulation (SMS) demonstrated a greater failure rate.

Conclusion  From the analysis of the literature, OCA transplantation seems to be the most reliable treatment of a failed SMS. ACI or MACI showed acceptable results in patients with previously failed MACI or ACI.

Level of Evidence  Level IV, systematic review of level I-IV studies.

Rehabilitation and Postoperative Management Practices After Osteochondral Allograft Transplants to the Distal Femur: A Report From the Metrics of Osteochondral Allografts (MOCA) Study Group 2016 Survey

Context:

We present the current spectrum of postoperative management practices for patients receiving distal femur osteochondral allograft (OCA) transplants.

Evidence Acquisition:

The Joint Restoration Foundation database was examined in cooperation with the Metrics of Osteochondral Allografts study group to identify 121 surgeons who had performed at least 1 OCA transplant in the past year; 63% of surgeons responded.

Study Design:

Clinical survey.

Level of Evidence:

Level 3.

Results:

Postoperative weightbearing restrictions ranged from immediate nonweightbearing with full weightbearing by 12 weeks to immediate weightbearing as tolerated. Most surgeons who performed fewer (<10) OCA transplants per year followed the most restrictive protocol, while surgeons who performed more (>20) OCA transplants per year followed the least restrictive protocol. One-third of surgeons with the most restrictive protocol were more likely to change their protocol to be less restrictive over time, while none of those with the least restrictive protocol changed their protocol over time. Fifty-five percent of surgeons permitted return to full activity at 26 weeks, while 27% of surgeons lifted restrictions at 16 weeks.

Conclusion:

Characterization of the spectrum of postoperative management practices after OCA transplantation provides a foundation for future investigations regarding patient outcomes and associated cost to establish best practice guidelines. Fundamentally, surgeons with more experience with this procedure tended to be more aggressive with their postoperative rehabilitation guidelines. Most commonly, rehabilitation provided for some degree of limited weightbearing; however, the spectrum also included immediate full weightbearing practices.

Bioprinting of osteochondral tissues: A perspective on current gaps and future trends

Osteochondral tissue regeneration has remained a critical challenge in orthopaedic surgery, especially due to complications of arthritic degeneration arising out of mechanical dislocations of joints. The common gold standard of autografting has several limitations in presenting tissue engineering strategies to solve the unmet clinical need. However, due to the complexity of joint anatomy, and tissue heterogeneity at the interface, the conventional tissue engineering strategies have certain limitations. The advent of bioprinting has now provided new opportunities for osteochondral tissue engineering. Bioprinting can uniquely mimic the heterogeneous cellular composition and anisotropic extra-cellular matrix (ECM) organization, while allowing for targeted gene delivery to achieve heterotypic differentiation. In this perspective, we discuss the current advances made towards bioprinting of composite osteochondral tissues and present an account of challenges-in terms of tissue integration, long-term survival, and mechanical strength at the time of implantation-required to be addressed for effective clinical translation of bioprinted tissues. Finally, we highlight some of the future trends related to osteochondral bioprinting with the hope of in-clinical translation.

Fresh osteochondral allotransplants: Outcomes, failures and future developments

Osteochondral allografts are used to treat many different conditions as acute traumatic large-sized lesions, degenerative osteoarthritis, osteochondritis dissecans, avascular necrosis or in case of failure of previous procedures particularly in young patients for whom primary prosthesis is not desirable. Fresh allografts present the advantage of having mature viable hyaline cartilage, not causing donor morbidity, allowing the restoration of even large defects in a single surgical session. Conversely, they could account for risks of disease transmission, immunologic reactions, and for limited availability. The present review aimed to analyze published studies of the last decade in which patients received fresh osteochondral allografts by dividing them for knee or ankle regenerative purposes. We wish to report the observed failure rates and particularly to collect any other reported side effect or outcome for identifying major problems and limits linked to the procedure and for delineating possible future researches and approaches. The overall success rates resulted ranging from 5.3% to 48.3% in the ankle at a mean follow up of 3.3 years and from 0% to 85.7% in the knee at a mean follow up of 7.1 years. Among other outcomes, occurrence or progression of arthritis, osteolysis, graft instability, fractures, nonunions, edema and infections were recorded. Overall, the lack of well designed randomized and controlled clinical trials, of immunological determination of the anti-donor antibodies development and of local and systemic biomarkers to detect reaction to the graft seems to be the major drawback. Improvements in these limiting factors might be desirable in order to enhance the clinical scenario of a well-established and successful procedure to give, especially for young patients, a real regeneration of the joint.

Bipolar fresh total osteochondral allograft in the ankle: Is it a successful long-term solution?

INTRODUCTION

Severe post-traumatic ankle arthritis poses a reconstructive challenge in young and active patients. Although technically demanding and despite unsolved immunological issues, bipolar fresh total osteochondral allograft (BFTOA) represent an intriguing option to arthrodesis and prosthetic replacement. The purpose of this paper is to evaluate the outcomes of a series of 48 ankle BFTOA at 10 years follow up and to investigate the rate of survival long term.

METHODS

58 patients underwent BFTOA, of these 48 were available for follow up. The allograft was prepared with the help of specifically designed jigs and the surgery was performed using either a lateral or a direct anterior approach. Patients were evaluated clinically and radiographically preoperatively, and at a mean 121±18months of follow-up.

RESULTS

The AOFAS score improved from 31±11 pre operatively, to 65±25 at the last (p<0.0005). Fourteen failures occurred, with 70.8% allograft rate of survival. All the surviving allografts showed a reduction of the ankle joint movement, still associated with a satisfactory clinical result.

CONCLUSION

The use of BFTOA represents an intriguing option to arthrodesis or arthroplasty. A satisfactory clinical result associated to a good movement of the transplanted joint is to be expected up to short-mid-term, overtime. Long term, the range of motion (ROM) is progressively decreased up to spontaneous arthrodesis in some cases, still the joint results pain free and patient's perception is of a well functioning ankle. A deeper knowledge of the immunological behavior of transplanted cartilage is needed in order to improve the durability of this fascinating technique.

Review of Mechanical, Processing, and Immunologic Factors Associated With Outcomes of Fresh Osteochondral Allograft Transplantation of the Talus

Osteochondral lesions of the talus (OLTs) are an increasingly implicated cause of ankle pain and instability. Several treatment methods exist with varying clinical outcomes. Due in part to successful osteochondral allografting (OCA) in other joints, such as the knee and shoulder, OCA has gained popularity as a treatment option, especially in the setting of large lesions. The clinical outcomes of talar OCA have been inconsistent relative to the positive results observed in other joints. Current literature regarding OCA failure focuses mainly on 3 factors: the effect of graft storage conditions on chondrocyte viability, graft/lesion size, and operative technique. Several preclinical studies have demonstrated the ability for bone and cartilage tissue to invoke an immune response, and a limited number of clinical studies have suggested that this response may have the potential to influence outcomes after transplantation. Further research is warranted to investigate the role of immunological mechanisms as an etiology of OCA failure.

LEVEL OF EVIDENCE

Level V, expert opinion.

Pathohistological investigation of osteochondral tissue obtained during total knee arthroplasty after osteochondral autologous transfer: a case report

Background

Osteochondral autologous transfer is one of the repair techniques for cartilage defects of knee with promising knee function recovery. There are no reports including histopathological images concerning human osteochondral tissue after osteochondral autologous transfer. This is the first report to present pathohistological findings of transplanted plugs and host tissues extracted from the human body 3 years after osteochondral autologous transfer. This study aimed to explore the cause factor of chronic pain using histological techniques.

Case presentation

A 67-year-old Japanese man presented with adjusted total knee arthroplasty 3 years after osteochondral autologous transfer. Although in pain, arthroscopic assessment was not severe. The specimens which was gained during total knee arthroplasty were investigated in gross and microscopically using immunohistochemical staining technic. Histological examination revealed that the gap between grafted plugs and host osteochondral tissues was filled with fibrous tissue that stained positive for type I collagen. A degenerative change and some neovascularity were observed in the regenerated tissue and host trabecular bone. Furthermore, cysts and bone marrow edema were observed.

Conclusion

Our data suggests that the host osteochondral morbidity around grafted plugs might be related to chronical pain and revision surgery.

Return to Sport and Recreational Activity After Osteochondral Allograft Transplantation in the Knee

BACKGROUND

Osteochondral allograft (OCA) transplantation is an integral part of the cartilage repair paradigm, but insufficient data are available regarding return to sport or recreational activity after the procedure.

PURPOSE

The purpose of this study was to determine if athletic patients undergoing OCA transplantation returned to sport, assess reasons for not returning to sport, and ascertain patient and graft-related characteristics that differed between those who returned or did not return to sport. The secondary aims were to assess graft survivorship and patient-reported subjective outcome measures (pain, function, satisfaction) among athletic patients undergoing OCA transplantation.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We identified 149 knees in 142 patients who participated in sport or recreational activity before a cartilage injury (45% highly competitive athletes and 55% well-trained and frequently sporting) and underwent OCA transplantation in the knee. The mean age was 31.2 years and 58.4% were male. Information on preinjury and postoperative participation in sport or recreational activity was collected. Patients not returning to sport after OCA transplantation were mailed a questionnaire to assess why. Postoperative pain, function, and satisfaction scores were obtained, and further surgery on the operative knee was documented.

RESULTS

At a mean follow-up of 6 years, 75.2% of knees returned to sport or recreational activity. Among those who did not return to sport, knee-related issues and lifestyle changes were cited as reasons why. Patients who did not return to sport were more likely to be female, have injured their knee in an activity other than sport, and have a larger graft size. The diagnosis and anatomic location also differed. Overall, 71% of knees reported having "very good" to "excellent" function, and 79% were able to participate in a high level of activity (moderate, strenuous, or very strenuous) postoperatively. After OCA transplantation, 25.5% of knees underwent further surgery; 14 knees (9.4% of entire cohort) were considered allograft failures. Among the 135 knees that had the graft remaining in situ, pain and function improved from preoperatively to the latest follow-up on all measures, and 91% of patients were satisfied with the results of the surgery.

CONCLUSION

OCA transplantation is a successful treatment option for athletes and highly active patients who sustain a cartilage injury to their knee. The majority of patients returned to sport or recreational activity.

Tibial Allograft Transfer for Medial Tibial Plateau Resurfacing

A large cartilage lesion of the tibial plateau with a deficient meniscus in a young patient is a challenging pathology for the orthopaedic surgeon due to the limited options available. While hemiarthroplasty procedures can be an option, the risk of revision in a young patient is high, and therefore a reconstructive procedure is advocated. The purpose of this Technical Note is to describe our technique for tibial plateau resurfacing, including the preparation and implantation of a medial tibial plateau and medial meniscal allograft, in a patient with a post-traumatic KD-4 knee dislocation with a medial tibial plateau rim fracture, medial meniscus deficiency, and medial tibiofemoral joint subluxation.

Fresh Osteochondral Allograft Transplantation for Fractures of the Knee

Objective The purpose of this study was to evaluate functional outcomes and allograft survivorship among patients with knee fracture who underwent fresh osteochondral allograft (OCA) transplantation as a salvage treatment option. Design Retrospective analysis of prospectively collected data. Setting Department of Orthopaedic Surgery at one hospital. Patients Fresh OCAs were implanted for osteochondral lesions after knee fracture in 24 males and 15 females with an average age of 34 years. Twenty-nine lesions (74%) were tibial plateau fractures, 6 (15%) were femoral condyle fractures, and 4 (10%) were patella fractures. Main Outcome Measurements Clinical evaluation included modified Merle d'Aubigné-Postel (18-point), International Knee Documentation Committee, and Knee Society function scores, and patient satisfaction. Failure of OCA was defined as revision OCA or conversion to total knee arthroplasty (TKA). Results Nineteen of 39 knees (49%) had further surgery. Ten knees (26%) were considered OCA failures (3 OCA revisions, 6 TKA, and 1 patellectomy). Survivorship of the OCA was 82.6% at 5 years and 69.6% at 10 years. Among the 29 knees (74%) that had the OCA still in situ, median follow-up was 6.6 years. Pain and function improved from preoperative to latest follow-up; 83% of patients reported satisfaction with OCA results. Conclusion OCA transplantation is a useful salvage treatment option for osteochondral lesions caused by knee fracture. Although the reoperation rate was high, successful outcome was associated with significant clinical improvement.

Fresh osteochondral allograft transplantation for osteochondritis dissecans of the capitellum in baseball players

BACKGROUND

Osteochondritis dissecans (OCD) of the capitellum is a rare yet debilitating injury seen in young athletes. This is the first report in the literature describing fresh osteochondral allograft transplantation (FOCAT) to treat OCD of the capitellum.

METHODS

Nine male baseball players (mean age, 15.3; range, 14-18 years), with OCD of the capitellum were treated with FOCAT. There were 6 pitchers and 3 position players. A ligament-sparing, mini-open approach was used. A fresh femoral hemicondyle was used as a donor source. Of the 9 patients, 7 required 1 plug and 2 required 2 plugs. The average plug diameter was 11 mm (range, 8-18 mm). Five plugs were press fit, and 4 required additional fixation. Clinical outcomes were evaluated at a mean follow-up of 48.4 months (range, 11-90 months). Preoperative and postoperative outcome scores were calculated using the paired t test.

RESULTS

The Mayo Elbow Performance score improved from an average 57.8 to 98.9 (P < .01). The Oxford Elbow Score improved from 22.4 to 44.8 (P < .01). The Disabilities of the Arm, Shoulder and Hand score improved from 35.2 to 5.4 (P < .01). The visual analog scale score improved from 7.8 to 0.5 (P < .01). The Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow score improved from 32.6 to 82.5 (P < .01). All patients returned to throwing and were still active in their sport or played at least 2 years of baseball before leaving the sport unrelated to the elbow.

CONCLUSIONS

FOCAT for OCD of the capitellum in properly selected cases is a viable treatment with significant functional improvement and pain reduction in throwers.

Deciding How Best to Treat Cartilage Defects

The decision-making regarding and treatment of cartilage abnormalities requires a systematic approach. This article reviews the concepts and principles that guide the management of this complex problem. The precise incidence, demographics, and progression of cartilage lesions have not been clearly delineated. Pursuing a patient-centered approach that considers the available nonsurgical and surgical options remains the cornerstone of patient care. The importance of determining concomitant knee pathologies, the proper interpretation and implications of imaging findings, and an accurate determination of the intra-articular and subchondral findings represent the primary elements of the decision analysis. Treatment options vary depending on patient goals, the disposition of the lesion, and a variety of other factors. The authors recommend proper patient education and consideration of how nonsurgical treatment or less invasive options such as arthroscopic debridement might be effective. If these strategies should fail, appropriate matching of a surgical procedure to the patient's pathology, goals, and expectations is warranted. Surgical options include debridement, marrow stimulation techniques, surface allograft treatments, autologous chondrocyte implantation, and osteochondral grafting (autograft and allograft) in addition to some emerging technologies. This article focuses on the decision-making process. [Orthopedics. 2016; 39(6):343-350.].

Osteochondral Allograft Transplantation in Patients With Osteochondritis Dissecans of the Knee

BACKGROUND

Osteochondritis dissecans (OCD) of the knee can be difficult to treat. Cartilage restoration techniques are often indicated when the lesion or fragment cannot be salvaged and the patient remains symptomatic. Fresh osteochondral allograft (OCA) transplantation can restore both bone and cartilage defects characteristic of OCD.

HYPOTHESIS

We hypothesized that osteochondral allografting is a successful method for treating OCD of the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This study comprised 135 patients (149 knees) who underwent OCA for OCD of the knee (type III or IV) between 1997 and 2013 and had a minimum follow-up of 2 years. The median age was 21 years (range, 12-55 years) and 75.8% of the patients were male. The mean allograft size was 7.3 cm² (range, 2.2-25 cm²). Evaluation included the following: frequency and type of reoperations; modified Merle d'Aubigné and Postel (18-point) scale; International Knee Documentation Committee (IKDC) pain, function, and total scores; and Knee Society function (KS-F) and knee (KS-K) scores. Clinical failure was defined as revision OCA or conversion to arthroplasty. Graft survivorship was determined.

RESULTS

The median follow-up time was 6.3 years (range, 1.9-16.8 years) and 62% of participants had more than 5-year follow-up. Thirty-four of 149 knees (23%) had reoperations, of which 12 (8%) were classified as allograft failures (7 OCA revisions, 3 unicompartmental knee arthroplasties, and 2 total knee arthroplasties). OCA survivorship was 95% at 5 years and 93% at 10 years. Of the 137 knees whose grafts were still in situ at the latest follow-up, the mean modified Merle d'Aubigné and Postel (18-point) score was 16.8; IKDC pain, function, and total scores were 2.1, 8.1, and 82.3; and KS-F and KS-K scores were 95.7 and 94.3, respectively. The majority of patients (95%) reported being satisfied with the outcome of their procedure.

CONCLUSION

OCA transplantation was an effective treatment for OCD of the knee, with a low rate of graft failure, significant improvement in pain and function scores, and high patient satisfaction.

Long-term Outcomes After Osteochondral Allograft: A Systematic Review at Long-term Follow-up of 12.3 Years

PURPOSE

To (1) evaluate long-term outcomes of osteochondral allograft (OCA) with regard to clinical outcome scores, reoperation and failure rates, and (2) examine if certain factors predispose patients to worse outcomes.

METHODS

A comprehensive review was performed with specific inclusion criteria for studies with long-term outcomes after OCA. Studies reported on patient clinical scores such as Hospital for Special Surgery score, Knee Society Score (knee and function score), and Lysholm score. Reoperation and failure rates were recorded for each study. Modified Coleman Methodology Scores assessed study methodological quality.

RESULTS

Five studies with a total of 291 patients (55% male, 45% female) and average age of 34.8 years (range, 15 to 69 years) were included. Of all lesions, 67% were on the femoral condyles, 29% on the tibial plateau, and 4% were patellofemoral. All scores (Knee Society Function Score, Knee Society Knee Score, and Lysholm score) have significant mean improvement from preoperative to final follow-up. The mean postoperative Hospital for Special Surgery score was 84.1. The mean failure rate was 25% at 12.3 years with a reoperation rate of 36%. A total of 72% of the failures were conversion to total (68%) or unicompartmental (4%) knee arthroplasty and 28% involved graft removal, graft fixation, and graft revision. Patellofemoral lesions (83%) had a significantly higher reoperation rate than lesions involving the tibial plateau or the femoral condyles (34%, P = .01).

CONCLUSIONS

Overall, OCA demonstrated significant improvements in clinical outcome scores and good durability with successful outcomes in 75% of the patients at 12.3 years after surgery. Patellofemoral lesions are associated with decreased clinical improvement and more frequent reoperations. The orthopaedic literature is limited by heterogeneity in surgical technique, lesion and patient characteristics, and reporting of nonstandardized outcome measures.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II and IV studies.

Fresh Osteochondral Allograft Versus Autograft: Twelve-Month Results in Isolated Canine Knee Defects

BACKGROUND

Osteochondral autografts and allografts have been widely used in the treatment of isolated grade 4 articular cartilage lesions of the knee. However, there is a paucity of literature regarding the basic science investigating the direct comparison between fresh osteochondral allografts to autografts.

HYPOTHESIS

At 12 months, fresh osteochondral allografts are equal to autografts with respect to function, bony incorporation into host bone, and chondrocyte viability.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight adult mongrel dogs underwent bilateral hindlimb osteochondral graft implantation in the knee after creation of an acute Outerbridge grade 4 cartilage defect. One hindlimb of each dog knee received an autograft, and the contralateral knee received an allograft. All dogs were sacrificed at 12 months. Graft analysis included gross examination, radiographs, magnetic resonance imaging (MRI), biomechanical testing, and histology.

RESULTS

MRI demonstrated excellent bony incorporation of both autografts and allografts, except for 1 allograft that revealed partial incorporation. Histologic examination of cartilage showed intact hyaline appearance for both autografts and allografts, with fibrocartilage at the host-graft interface of both. Biomechanical testing demonstrated no significant difference between allografts and autografts (P = .76). Furthermore, no significant difference was observed between allografts and the native cartilage with biomechanical testing (P = .84).

CONCLUSION

After 12 months from time of implantation, fresh osteochondral allograft tissue and autograft tissue in this study were not statistically different with respect to biomechanical properties, gross morphology, bony incorporation, or overall histologic characteristics. When compared with the previously reported 6-month incorporation rates, there was improved allograft and autograft incorporation at 12 months.

CLINICAL RELEVANCE

With no significant differences in gross examination, radiographs, MRI, biomechanical testing, or histology in the canine model, the use of allograft tissue to treat osteochondral defects may eliminate the morbidity associated with autograft harvest.

Development of a Fresh Osteochondral Allograft Program Outside North America

OBJECTIVE

To standardize and to develop a fresh osteochondral allograft protocol of procurement, processing and surgical utilization in Brazil. This study describes the steps recommended to make fresh osteochondral allografts a viable treatment option in a country without previous fresh allograft availability.

DESIGN

The process involves regulatory process modification, developing and establishing procurement, and processing and surgical protocols.

RESULTS

Legislation: Fresh osteochondral allografts were not feasible in Brazil until 2009 because the law prohibited preservation of fresh grafts at tissue banks. We approved an amendment that made it legal to preserve fresh grafts for 30 days from 2°C to 6°C in tissue banks. Procurement: We changed the protocol of procurement to decrease tissue contamination. All tissues were procured in an operating room. Processing: Processing of the grafts took place within 12 hours of tissue recovery. A serum-free culture media with antibiotics was developed to store the grafts. Surgeries: We have performed 8 fresh osteochondral allografts on 8 knees obtaining grafts from 5 donors. Mean preoperative International Knee Documentation Committee (IKDC) score was 31.99 ± 13.4, improving to 81.26 ± 14.7 at an average of 24 months' follow-up. Preoperative Knee Injury and Oseoarthritis Outcome Score (KOOS) score was 46.8 ± 20.9 and rose to 85.24 ± 13.9 after 24 months. Mean preoperative Merle D'Aubigne-Postel score was 8.75 ± 2.25 rising to 16.1 ± 2.59 at 24 months' follow-up.

CONCLUSION

To our knowledge, this is the first report of fresh osteochondral allograft transplantation in South America. We believe that this experience may be of value for physicians in countries that are trying to establish an osteochondral allograft transplant program.

Large osteochondral lesions of the femoral condyles: Treatment with fresh frozen and irradiated allograft using the Mega OATS technique

BACKGROUND

The purpose of this study was to review the clinical results of irradiated fresh frozen osteochondral allografts for large osteochondral defects of the knee using the Mega-OATS technique.

METHODS

Nine patients with a mean age of 32.1±6.6 (18 to 44) underwent Mega-OATS transplantation with irradiated (2.5Mrad), fresh frozen distal femur allograft. Three patients also underwent ACL-reconstruction; one patient a high tibial osteotomy. The underlying indication was osteochondrosis dissecans in four and trauma in five patients. The defect size was 25×25mm in three patients and 30×30 in six patients and the depth ranged from eight to 14mm. All OCD lesions were located on the medial femoral condyle; two of the traumatic lesions were located on the lateral femoral condyle. Clinical outcome was assessed using the Lysholm and IKDC scores. Radiographic incorporation was evaluated using serial radiographs and MR imaging at one year post surgery. All patients were reviewed at three, six, 12, and 24months following surgery.

RESULTS

The Lysholm (IKDC) score improved significantly (p=0.02 resp. p=0.007) within and between patients during the follow-up period from 40.9 (37) to 90.9 (87.1) at 2years. Radiographic union was observed in all patients at three months; on MR imaging at one year osseous integration was observed in eight patients. Graft subsidence with loss of the overlying cartilage was observed in one and subchondral cystic changes at the implantation side were seen in another patient.

CONCLUSION

The results of this case series suggest that irradiated osteochondral allograft provides significant medium-term clinical improvement in patients treated for large osteochondral lesions of the femoral condyles.

LEVEL OF EVIDENCE

IV, case series.

Osteochondral Allograft Transplantation of the Femoral Trochlea

BACKGROUND

Osteochondral allograft (OCA) transplantation is a recognized treatment modality for cartilage damage in the knee. Few reports are available on outcomes of OCA in the patellofemoral joint, and there are no reports on lesions isolated to the femoral trochlea.

PURPOSE

To evaluate graft survivorship and clinical outcomes in patients who had an OCA to the femoral trochlea.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

An OCA database was used to identify 29 knees in 28 patients (mean age, 30.2 years; range, 12-47 years; 8 female, 20 male) who were treated with a fresh OCA transplant limited to the femoral trochlea. The primary outcome was graft survivorship, and the minimum follow-up was 2 years. Clinical outcomes were assessed by the modified Merle d'Aubigné-Postel (18-point) score; Knee Society function (KS-F) score; International Knee Documentation Committee (IKDC) pain, function, and total scores; and University of California, Los Angeles (UCLA) activity score. The OCA patient satisfaction score (5-point scale from extremely satisfied to dissatisfied) was also reported.

RESULTS

The mean follow-up period was 7.0 years (range, 2.1-19.9 years). Graft survivorship was 100% at 5 years and 91.7% at 10 years. One patient was converted to a total knee arthroplasty 7.6 years after OCA surgery. The mean modified Merle d'Aubigné-Postel score improved from 13.0 to 16.1, the mean KS-F score from 65.6 to 85.2, and the mean IKDC total score from 38.5 to 71.9; the mean UCLA score was 7.9 postoperatively. Eighty-nine percent of patients were extremely satisfied or satisfied with the outcome of surgery.

CONCLUSION

Fresh OCA transplantation resulted in excellent clinical outcomes in this patient cohort with articular cartilage damage to the femoral trochlea. The procedure resulted in improved pain and function and high patient satisfaction.

Fresh Osteochondral Allograft Transplantation for Treatment of Articular Cartilage Defects of the Knee

Articular cartilage damage of the knee can cause severe morbidity. Owing to its avascular nature, articular cartilage has limited potential for self-healing and increased propensity to progress to osteoarthritis. Treatment of large, full-thickness cartilage defects is still a challenge for orthopaedic surgeons but has recently achieved high success rates with the use of osteochondral allografts. This article details our technique of osteochondral allograft transplantation for the treatment of articular cartilage defects of the knee.

Osteochondral allograft

Over the past decade, osteochondral allograft transplantation has soared in popularity. Advances in storage techniques have demonstrated improved chondrocyte viability at longer intervals and allowed for potential of increased graft availability. Recent studies have stratified outcomes according to location and etiology of the chondral or osteochondral defect. Unipolar lesions generally have favorable outcomes with promising 10-year survival rates. Though those undergoing osteochondral allograft transplantation often require reoperation, patient satisfaction remains high.

Medial Femoral Condyle Cartilage Defect Biomechanics: Effect of Obesity, Defect Size, and Cartilage Thickness

BACKGROUND

Medial femoral condyle (MFC) chondral defects cause knee pain. Clinical studies have shown worse functional outcomes and cartilage defect fill rates after microfracture in obese patients (BMI ≥30) and for defects with size ≥2 cm(2).

PURPOSE

To determine the effect of obesity, defect size, and cartilage thickness on the force sustained at the base of full-thickness MFC cartilage defects during weightbearing.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight human cadaveric knees were loaded in 15° of flexion. A sensor measured force across the medial compartment. The area at the base of the defect protected from load, termed the "area of containment," was quantified, and loads simulating weightbearing for BMIs of 20, 30, and 40 were applied. A full-thickness cartilage defect was created on the MFC. Cycles of loads were applied for defect sizes with diameters of 6, 8, 10, 12, 14, 16, 18, and 20 mm. A second sensor recorded force at the base of the defect for defects with diameters of 14, 16, 18, and 20 mm.

RESULTS

Loads simulating BMI ≥30 led to a decrease in the area of containment for all defects ≥14 mm in diameter (P ≤ .038). Base of defect force increased for defects ≥16 mm in diameter (area, ≥2 cm(2)) between loaded and unloaded states (P ≤ .042) and for loads simulating BMI ≥30 (P ≤ .045). Cartilage rim thickness <2 mm showed higher base of defect force than did thickness ≥2 mm, for all BMI groups (P ≤ .025).

CONCLUSION

Increased force at the base of MFC cartilage defects was observed for weightbearing loads simulating BMI ≥30, for defect size ≥2 cm(2), and for rim thickness <2 mm. This may lead to a biomechanically unfavorable environment after microfracture in these patient subsets.

CLINICAL RELEVANCE

These biomechanical findings corroborate clinical studies that have noted worse outcomes after microfracture in patients with BMI ≥30 and cartilage defects of size ≥2 cm(2). Further clinical studies are needed to compare microfracture with other cartilage restoration procedures in these patient subsets.