Purpose

Meniscus allograft transplant (MAT) is traditionally not recommended for patients with moderate to severe osteoarthritis. We hypothesize that clinical and graft survival of MAT will not be impacted by the severity of cartilage damage assessed by Outerbridge (OB) grade at the time of surgery, if the damaged cartilage is also treated.

Methods and Materials

Clinical data and patient reported outcome measures (PROMs) were recorded for 343 procedures (310 patients). Articular cartilage damage was repaired at time of MAT, and intraoperative OB grade was recorded for later analysis. PROMS were assessed using WOMAC, IKDC and Tegner scores. Graft failure was defined as allograft removal without revision, progression to unicompartmental or total knee replacement. 10% increase in WOMAC pain score = clinical failure. Statistical analysis included X2, t-tests, paired t-tests, Kaplan-Meier (KM) survival analysis and Cox proportional hazards model; α<0.05.

Results

Intraoperative articular cartilage status did not significantly affect graft failure (log-rank test, p=0.206) or clinical failure (log-rank test, p=0.889) as assessed by KM survival analysis (Figure 1). Mean graft survival and clinical survival were 17.8 years and 16.7 years respectively. 245/343 (71.4%) patients had moderate to severe articular cartilage changes (OB III-IV). Patients greater than 2 years post-op experienced significant (P=0.0001) improvement in PROMs as measured by pain, activity and function (Figure 2); mean follow-up time= 5.72 ± 4.37 years. Mean age = 42.9 ± 11.6 years.

Conclusion

Graft and clinical survival is independent of OA status, measured by ipsilateral compartment OB grade at time of surgery, provided chondral lesions are repaired prior to or during MAT. Mean estimated benefit time is 16 years. Indications for MAT should be expanded to include older subjects with more severe cartilage degenerative changes.
This data provides support for the field of biological joint replacement and the treatment of arthritic knees with tissue regeneration and replacement.

Purpose

While multiple studies have shown the effectiveness of osteochondral allograft transplantation (OCA) in the treatment of symptomatic chondral defects, outcomes in obese patients (BMI >30) have not been well defined. This study aims to determine outcomes in patients undergoing OCA based on BMI.

Methods and Materials

Between 2014 and 2017, 235 patients underwent OCA at our institution and completed pre-operative patient-reported outcomes. IKDC, KOOS, and Marx were collected pre-operatively and at 6-months, 1-year, and 2-years post-operatively. Patients were stratified into groups based on common obesity classification- BMI: <20, 20-<25, 25-<30, 30-<35, >35. One-way ANOVA and Student T-tests were performed to analyze differences in outcome scores between groups.

Results

A total of 235 patients (30.0±9.42 years, 53.6% female) with average BMI 26.6±4.40 and mean lesion size 3.2±1.17cm² completed 2-year follow-up and were included in this study. Patients with BMI <35 demonstrated significant improvement in PROs at 1-year post-operatively for IKDC, KOOS Symptoms, KOOS Pain, KOOS ADL, and KOOS Sport (all p<0.05). Patients with BMI <30 also showed significant improvement in KOOS QoL. Those with BMI >35 only showed significant improvement in KOOS Pain at 1 year (Table 1). Patients with BMI >25 showed significant decrease in Marx at 1 year. Patients with BMI’s >30 demonstrated significantly lower baseline, 6-month, and 1-year PRO scores relative to those with BMIs <25 (Figure 1) and significantly less improvement in KOOS PS and KOOS JR at 6 months.

Conclusion

Those with BMI >30 have significantly lower preoperative baseline PROs as well as significantly lower 1-year scores when compared to those with BMIs <30. However, significant improvements are still observed across PROMs in patients with BMI <35, suggesting those with BMI <35 experience clinically significant benefits after OCA. Further research should consider defining outcomes in those with greater BMIs based on clinically significant thresholds (MCID, SCB, PASS).

Purpose

Osteochondral allograft transplantation (OCA) of the patella is limited by the availability of suitable size-matched patella donor tissue. The purpose of this study was to assess magnetic resonance imaging (MRI) and clinical outcomes of patients treated with non-orthotopic patellar OCA using a femoral hemicondyle (FH) donor.

Methods and Materials

A prospective institutional registry review identified 43 patients treated with patellar OCA using FH donor from 2009 to 2016. OCA plugs were harvested from FH at the trochlea-condyle junction and implanted using press-fit technique (Figure 1). Bone, cartilage, and ancillary features on postoperative MRI were graded by a blinded musculoskeletal radiologist using the Osteochondral Allograft MRI Scoring System (OCAMRISS). VAS, IKDC, and KOS-ADL scores preoperatively and at 1 year postoperatively were compared using the paired t-test.

Results

Mean age was 36.6 years (range, 22 to 55 years), and mean body mass index 25.8 (range, 21.9 to 41.3), 61% female. Mean preoperative tibial tubercle to trochlear groove distance (TT-TG) was 14.0 mm (range, 5.5 to 19.8 mm). Donor specimens were 73%, 16%, and 11% lateral hemicondyle, medial hemicondyle, and whole distal femur allograft, respectively. On MRI at 11.4 months (range, 6 to 22 months) postoperative, mean total OCAMRISS score was 9.0 (range, 7 to 11). Mean bone, cartilage, and ancillary subscores were 2.6, 3.7, and 2.6, respectively. 59% of grafts demonstrated full osseous integration with crossing trabeculae and no discernable cleft, 65% demonstrated absence of cystic change at graft interfaces (Figure 2). At latest follow-up (mean 46.5 months, range 12-85 months), postoperative improvements in VAS (5.0 to 3.4; P=0.03), IKDC (45.4 to 63.0; P = 0.01) and KOS-ADL (62.7 to 75.1; P = 0.005) were noted.

Conclusion

OCA using non-orthotopic FH donor is a viable option for treatment of patellar osteochondral lesions, as it leads to improved pain and patient-reported outcomes, and good osseous incorporation on MRI.

Purpose

Osteochondral allograft (OCA) transplantation is a valuable treatment option for chondral and osteochondral lesions of the knee. Understanding the impact of clinical variables on the outcome of OCA transplantation would be useful for counseling patients on the relative risk of the procedure. The purpose of this study was to determine which variables predicted treatment failure in a large cohort of patients undergoing OCA transplantation of the knee.

Methods and Materials

OCA transplantation was performed in 673 knees from 1997 to 2016; 489 had a minimum follow-up of two years. Average age was 32 years and 63% were male. Mean graft size was 8.9 cm². Reoperations following the OCA transplantations were assessed, and treatment failure was defined as any procedure that involved removal of the allograft. Variables associated with treatment failure in univariate analyses (age, diagnosis, anatomic location, and graft size; Table 1) were included in a logistic regression model.

Results

Treatment failure occurred in 78 knees (16%); 58 conversions to arthroplasty, 19 revision allografting, and 1 patellectomy. Age, diagnosis, and graft size independently predicted a higher risk of failure (Table 2). Patients who were ≥30 years old were 2.4 times more likely than younger patients to experience a treatment failure. Compared to patients with osteochondritis dissecans or traumatic chondral injury, patients with degenerative chondral lesions, avascular necrosis, or osteoarthritis were more likely to have allograft failure. Grafts >8 cm² were 2.1 times more likely to fail than grafts ≤8 cm². Anatomic location and number of grafts were associated with failure in univariate analyses, but not after controlling for other variables in the multivariate analysis.

Conclusion

Older age, diagnosis of avascular necrosis or degenerative joint disease, and larger graft size were associated with higher risk of treatment failure. This data is useful in counseling individual patients on the risk of osteochondral allograft surgery.

Purpose

To determine if differences in patellar surface morphology (e.g., Wiberg classification) play a role in the ability of donor patellar osteochondral allografts to acceptably (<1mm deviation) match the native patellar surface for osteochondral defects involving the patellar central ridge.

Methods and Materials

Each of twenty (10 Wiberg I and 10 Wiberg II/III) fresh frozen recipient patellae were size-matched (within 2mm tibial width) with a Wiberg I and Wiberg II/III donor patella. A 16mm diameter osteochondral “defect” centered on the central ridge of the recipient patella was created (Fig. 1A). Within each patellar trio, a randomly ordered donor Wiberg I or Wiberg II/III patellar plug was harvested, transplanted, scanned with nano-CT, digitally reconstructed, and processed in DragonFly to determine circumferential step-off heights between the native and donor surfaces, percent of the circumference unacceptably proud (>1mm), and unacceptably sunken (>1mm) (Fig. 1B-D). The process was then repeated for the other allograft plug. Paired t-tests and one-way ANOVAs with Sidak comparisons were used (α = 0.05). Calculated sample size = 7/group.

Results

There was no significant difference in step-off heights between matched and unmatched Wiberg plugs. When analyzing by quadrant, the step-off heights of the superior and inferior quadrants were significantly different, but not clinically relevant, across all patellas and Wiberg I recipients. The inferior quadrant of Wiberg I recipient patellas demonstrated a significant, but not clinically relevant, difference between matched and unmatched Wiberg donors (Table 1). No significant differences between matched and unmatched donors for the percent of circumference unacceptably proud. Difference of <4% between groups in percent of circumference unacceptably sunken (lateral quadrant).

Conclusion

Differences in Wiberg classification did not lead to differences in step-off heights circumferentially, or by quadrant. These findings suggest patellar surface morphology doesn’t play a role in matching donor allografts for patellar osteochondral defects.

Purpose

Osteochondral allograft (OCA) transplantation has demonstrated good functional outcomes and high rates of return to sport but in small cohort studies. This study reports the return to athletic activity and functional outcomes at minimum two years in a broader cohort of active patients who underwent knee OCA transplantation and reports predictive factors for return to activity.

Methods and Materials

Between 2000 – 2016, 163 active patients who underwent OCA transplantation within our institutional cartilage registry met inclusion criteria. ‘Active’ was defined as baseline pre-operative Cincinnati Sports Activity Scale (CSAS) of 3 or better (active at least 1-3x per month), running frequency of at least 1x/week or self-reported participation in sports at the time of injury. Patient characteristics and patient reported outcomes at yearly intervals (Knee Outcome Survey-Activities of Daily Living (KOS-ADL) score, International Knee Documentation Committee (IKDC) score, Marx Activity Rating Scale were reported.

Results

Patient characteristics are described in Table 1 . Mean age of the cohort was 39.4 +12.9 years with a male predominance (67%). At minimum two year follow-up, 144/163 patients (88.3%) returned to athletic activity (CSAS level 1-3), and 118/163 patients (76%) returned to the same level of activity or higher. Patient-reported outcomes are reported in Table 2. Mean change in KOS-ADL and IKDC at 2 years was 19 points and 25 points, respectively; which met the thresholds for minimal clinically important difference. Clinical predictors of return to activity on multivariate analysis were preoperative CSAS level 1 activity (participates 4+ days/week), and preoperative IKDC of >38 pts.

Conclusion

OCA results in high rates of return to athletic activity in active patients at 2 years. Clinically meaningful improvement in patient-reported outcome measures can be expected for most patients. High level of pre-operative function and activity were predictive of return to activity postoperatively.

Purpose

Osteochondral allograft (OCA) transplantation of the knee is an effective treatment for chondral and osteochondral lesions, but graft survivorship and clinical outcomes vary by patient-specific factors. Fresh OCA are often used for large or complex lesions or in the revision cartilage repair setting, but recent literature suggests that the most ideal candidates for OCA transplantation may be young patients with a small lesion on the femoral condyle or trochlea due to osteochondritis dissecans or chondral trauma. The purpose of this study was to assess outcomes following OCA transplantation in a cohort of “ideal” candidates.

Methods and Materials

We identified 91 patients (97 knees) who underwent primary OCA transplantation for osteochondritis dissecans (88%) or a traumatic chondral injury (12%), were age 30 years or younger, and had an isolated lesion(s) of the femoral condyle or trochlea less than 8 cm². Mean age was 20 years and 70% were male. Lesions were located on the femoral condyle (85%) or trochlea (15%). One graft was used in 85% of knees and two grafts were used in 15%. Mean total graft area was 5.2 cm². Evaluation included pain, function, satisfaction, and reoperations. OCA failure was defined as revision allografting or conversion to arthroplasty. Median follow-up was 5.7 years (range 2-17 years).

Results

Seventeen knees (18%) underwent reoperations. Two knees (2%) were classified as OCA failures (one revision OCA at 2.7 years and one conversion to unicompartmental arthroplasty at 10.2 years). Survivorship was 99% at 5 and 10 years. Pain and function improved (Table 1.), and 93% of patients were satisfied with the results of the OCA transplantation.

Conclusion

In this cohort of “ideal” cartilage repair patients undergoing OCA transplantation, graft survivorship and clinical outcomes were excellent, with high satisfaction, pain relief, and functional improvement. Outcomes were equal or superior to other cartilage repair techniques.

Purpose

The use of allograft tissue for reconstruction of articular cartilage and menisci is a viable and clinically effective solution. The purpose of this study was to evaluate the cost effectiveness of osteochondral allografts and meniscal allograft transplantation in knee reconstruction, as part of a European collaberative initiative.

Methods and Materials

A full health technology assessment was performed evaluating clinical and cost-effectiveness. Articles published from 2000 to February 15^th 2018 were analysed using standard systematic review methods. Data, costs and natural history assumptions were formulated in a Markov model, developing base-case analysis, transition probabilities and utilities to quantify cost-effectiveness.

Results

Osteochondral allografts (OCA) are clinically effectiveness with a high graft survival rate over 20 years. OCA appears highly cost-effective, but the cost per quality adjusted life year varies according to the widely-varying costs of allografts. Using UK health service costs of £15,560 for surgery, and a survival rate of 68% at 20 years, the ICER for OCA was £4,692, far below the NICE threshold for treatment costs.

Meniscal transplantation (MAT) is clinically effective in relieving symptoms, as measured by KOOS, IKDC and Tegner scores. Cost-effectiveness analysis is problematic due to lack of evidence on chondroprotection. Control groups matching symptomatic patients undergoing MAT is lacking with only one small pilot RCT. Data on determining at risk groups was found to be lacking and is required to measure effect size. MAT is considered likely to be cost-effective in at risk group but defining such groups was unclear.

Conclusion

OCA is both clinically effective and cost effective. MAT is clinically effective, but cost-effectiveness is unclear. This analysis provides essential information to aid decision making for surgeons and funding authorities. Specific data and research is required to provide robust information on cost-effectiveness of meniscal allografts

Purpose

Patients undergoing osteochondral allograft transplantation (OCA) for articular cartilage defects have demonstrated significant post-operative improvements in patient-reported outcome scores. The purpose of this study is to examine the achievement of clinically significant outcomes, minimally clinically important difference (MCID), in patients undergoing OCA, and identify factors associated with achievement.

Methods and Materials

A prospectively maintained institutional database was reviewed for all patients who have completed 2-year follow-up after OCA between 2014 and 2017. Achievement of MCID on various PROMs including International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain subscore were evaluated. Thresholds for MCID achievement were based on previously published literature in OCA patients (IKDC: 9.8; KOOSPain; 16.7). MCID achievement rates were examined across 6 month, 1 year and 2 year follow-up time points, and univariate analysis was utilized to examine the effect of lesion size and demographic factors on achievement rates.

Results

A total of 235 patients (30.0±9.42 years, 53.6% female, BMI 26.6±4.40) were included, with an average lesion size of 3.20±1.17cm². Achievement rates of MCID at 6-month, 1-year and 2-year time points were 54.07%, 79.31% and 80.95% for IKDC and 42.96%, 56.98% and 61.90% for KOOSPain, respectively. Patients had significantly increased odds of reporting MCID achievement on IKDC at 2 years when compared to 6 months [Odds Ratio: 3.16, p=0.003). Females were more likely than males to report MCID achievement on IKDC (p=0.043). Patients achieving MCID on KOOSPain had lower average BMIs than those failing to achieve MCID (26.1±4.0 vs. 27.5±4.5, p=0.043).

Conclusion

Two years post-operatively after OCA, achievement rates of MCID on function and pain outcome measures exceed 60%. Female patients are more likely to report some benefit in function following MFX than male counterparts, and those with greater preoperative BMIs are less likely to report minimal benefits with respect to pain.

Purpose

Despite improvements in treatment, articular cartilage lesions continue to be a major source of pain and disability. A recently developed fresh, cartilage allograft (ProChondrix, Allosource, Centennial, CO) has become available for treatment of articular cartilage lesions. This graft contains extracellular matrix, native growth factors and viable chondrocytes. While it has demonstrated promising results in laboratory and equine studies, its efficacy in human clinical use remains unknown. The purpose of this study is to evaluate the three year follow-up results of a novel 3D fresh cartilage matrix on isolated articular cartilage defects.

Methods and Materials

17 patients with isolated, symptomatic articular cartilage surface lesions were treated with microfracture followed by placement of a ProChondrix graft. Demographic and intra-operative data was recorded as well as pre- and post-operative International Knee Documentation Committee (IKDC), Short Form-36 (SF-36), Knee Injury and Osteoarthritis Outcome Score (KOOS), Visual Analogue Scale (VAS) and Tegner scores. Pre- and post-operative data was compared at 6, 12, 24, and 36 months post-operatively. Failures requiring reoperation were also recorded.

Results

At a mean follow-up of 2.5 years (6-43 months), VAS decreased from 6.55 to 2.55 (p=.02) and subjective IKDC scores increased from 37.61 to 59.65 (p=.02). Statistically significant increases were also seen in KOOS Function-Sports and Recreational Activities (+26.04, p=.04) and KOOS QOL (+18.76, p=.007) as well as in SF-36 Physical Functioning (+25.20, p=.04), Energy/Fatigue (+16.50, p=.02), Social Functioning (+11.79, p=.04), and Bodily Pain (+25.18, p=.04). There were two failures requiring reoperation: one conversion to a PFA, and one graft dislodging.

Conclusion

Treatment of articular cartilage lesions with ProChondrix have demonstrated sustained positive results out to 3 years in this case series. 2 failures required reoperation in this series.