Return to Sport and Sports-Specific Outcomes After Osteochondral Allograft Transplantation in the Knee: A Systematic Review of Studies With at Least 2 Years' Mean Follow-Up

Editorial Commentary: Three-Dimensional-Printed Biphasic (Osteochondral) Scaffolds Delivering Autologous Chondrocytes Hold Clinical Promise

Three-dimensional-printed biphasic scaffolds combine autologous chondrocytes for effective cartilage repair. A recent study demonstrated promising short-term outcomes for biphasic scaffolds compared with traditional marrow-stimulation techniques, although long-term durability and appropriate control comparisons remain concerns. Scaffold materials can include polysaccharides (e.g., alginate, hyaluronic acid, and chitosan) and proteins (e.g., collagen, gelatin, and fibronectin). They also may be combined with other classes of materials to improve their mechanical properties and bioactivity. Synthetic polymers include polyethylene glycol and poly(lactic-co-glycolic acid), among many others. Challenges of these scaffold materials include biocompatibility, inadequate integration, and variability in clinical outcomes. Delivering autologous minced chondrocytes via a biphasic scaffold consisting of poly(lactic-co-glycolic acid) for the chondral phase and β-tricalcium phosphate for the osseous phase is a promising technology.

Comparable Clinical and Functional Outcomes Between Osteochondral Allograft Transplantation and Autologous Chondrocyte Implantation for Articular Cartilage Lesions in the Patellofemoral Joint at a Mean Follow-Up of 5 Years

PURPOSE

To assess clinical outcomes and return to sport (RTS) rates among patients who undergo osteochondral allograft (OCA) transplantation and autologous chondrocyte implantation (ACI) or matrix-induced autologous chondrocyte implantation (MACI), for patellofemoral articular cartilage defects.

METHODS

A retrospective review of patients who underwent an OCA or ACI/MACI from 2010 to 2020 was conducted. Patient-reported outcomes collected included visual analog scale for pain/satisfaction, Knee Injury and Osteoarthritis Outcome Score (KOOS), and RTS. The percentage of patients that met the patient acceptable symptom state for KOOS was recorded. Logistic regression was used to identify predictors of worse outcomes.

RESULTS

A total of 95 patients were included (78% follow-up) with ACI or MACI performed in 55 cases (57.9%) and OCA in 40 (42.1%). A tibial tubercle osteotomy was the most common concomitant procedure for OCA (66%) and ACI/MACI (98%). Overall, KOOS pain was significantly poorer in OCA than ACI/MACI (74.7, 95% confidence interval 68.1-81.1 vs 83.6, 95% confidence interval 81.3, 88.4, P = .012), whereas the remaining KOOS subscores were nonsignificantly different (all P > .05). Overall, RTS rate was 54%, with no significant difference in return between OCA or ACI/MACI (52% vs 58%, P = .738). There were 26 (27%) reoperations and 5 (5%) graft failures in the entire group. Increasing age was associated with lower satisfaction in OCA and poorer outcomes in ACI/MACI, whereas larger lesion area was associated with lower satisfaction and poorer outcomes in ACI/MACI.

CONCLUSIONS

Clinical and functional outcomes were similar in patients who underwent OCA or ACI/MACI for patellofemoral articular cartilage defects at a mean follow-up of 5 years. Patients who received OCA had a greater proportion of degenerative cartilage lesions and, among those with trochlear lesions, reported greater pain at final follow-up than their ACI/MACI counterparts. Overall, increasing age and a larger lesion size were associated with worse patient-reported outcomes.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Return to Sport in Athletes After Osteochondral Allograft Transplantation: A Systematic Review

BACKGROUND

Management of symptomatic osteochondral defects of the knee remains challenging because of the limited inherent vascularity and healing potential of articular cartilage. Osteochondral allograft (OCA) transplantation has yielded satisfactory results in appropriate patients; however, the effect of OCA transplantation on athletes seeking to return to sport (RTS) remains largely unknown.

PURPOSE

To systematically review the literature to better understand outcomes after OCA, focusing on RTS rate and timing, and the incidence of postoperative complications.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Studies included in the PubMed, EMBASE, and Cochrane Library databases from inception to August 2024 that reported on athletes participating at the recreational, high school, collegiate, and professional levels undergoing OCA transplantation for osteochondral defects in the knee were identified. Inclusion criteria included studies reporting on patients identified as athletes undergoing OCA transplantation with reported origin, lesion characteristics (size and location), RTS rate and timing, complications, reoperations, and patient-reported outcomes.

RESULTS

A total of 14 studies, consisting of 471 athletes undergoing OCA transplantation with a weighted mean follow-up of 51.1 months, were identified. The weighted mean patient age was 31.4 years (range, 15-69 years), with 61% of patients being male. Lesion origin was reported in 49% (230/471) of patients, with osteochondritis dissecans (OCD) reported in 44% (100/230). The medial femoral condyle was the most common defect location (44%; 68/153). Lesion size ranged from 1 to 13.94 cm2. Sixteen percent (75/471) of patients were classified as competitive athletes, with basketball (n = 21) being the most common sport. RTS was reported in 72% (338/468) of patients, with 84% (231/275) returning at an equal or higher level of play at a weighted mean of 11.1 months (range, 6-26 months) after OCA. Complications were reported in 12% (41/351) of patients, with graft failure accounting for 54% (22/41) of complications in 6% (22/351) of patients.

CONCLUSION

For athletes undergoing OCA transplantation to the knee, OCD was the most commonly reported cause, with the medial femoral condyle most frequently affected. Successful RTS was reported in 72% of patients at a mean of 11.1 months, with graft failure representing the most common complication in 6%.

High Rate of Return to Sport for Athletes Undergoing Articular Cartilage Restoration Procedures for the Knee: A Systematic Review of Contemporary Studies

BACKGROUND

Continued advancements in cartilage surgery and an accumulating body of evidence warrants a contemporary synthesis of return to sport (RTS) outcomes to provide updated prognostic data and to better understand treatment response.

PURPOSE

To perform an updated systematic review of RTS in athletes after knee cartilage restoration surgery.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

PubMed, OVID/Medline, and Cochrane databases were queried in October 2023 for studies reporting any RTS outcome after knee cartilage restoration surgery. Meta-analyses with inverse-variance proportion and DerSimonian-Laird random-effects estimators were applied to quantify overall RTS. Comparative proportional subgroup meta-analyses with relative odds ratios (ORs) were constructed to quantify (1) the influence of the procedure on RTS and (2) RTS ability (lower vs same/greater level of play) based on procedure, competition level, and specific sport.

RESULTS

A total of 52 studies (n = 2387) were included. The overall pooled RTS was 80.3% (95% CI, 73.3%-86.5%). Matrix-assisted chondrocyte implantation (MACI) (OR, 2.15) and osteochondral autograft transplantation system (OATS) (OR, 1.83) demonstrated the highest likelihoods of RTS at the same/greater level, while microfracture (MF) (OR, 0.78) was the only treatment demonstrating a higher likelihood of RTS at a lower level. The fastest mean RTS was observed after OATS (6.6 ± 2.6 months). Professional athletes demonstrated an OR of 1.01 for RTS at the same/greater level, whereas recreational/amateur athletes demonstrated an OR of 1.63; however, all professional athletes underwent MF, and recreational/amateur athletes who underwent MF demonstrated lower likelihoods of RTS (OR, 0.78), indicating a consistent association between MF and low RTS propensity. Basketball players demonstrated the lowest likelihood of RTS at the same/greater level (OR, 1.1), while American football and soccer were associated with high likelihoods of RTS (OR, 3 and 2.4, respectively) across all procedure types.

CONCLUSION

Cartilage restoration allows for high overall RTS, with OATS and MACI conferring the greatest propensity for RTS, while OATS allowed for the fastest RTS. Undergoing MF was associated with consistently poor RTS ability. This study identified several important associations between the level of RTS and clinically relevant factors when discussing RTS, with recreational/amateur athletes, soccer players, and American football players demonstrating a higher relative propensity to RTS.

Outcomes of Revision Cartilage Restoration Surgery for Failed Primary Treatment of Chondral or Osteochondral Defects of the Knee: A Systematic Review

BACKGROUND

Failure of primary cartilage restoration procedures of the knee that proceed to necessitating revision cartilage procedures represent a challenging clinical scenario with variable outcomes reported in previous literature.

PURPOSE

To perform a systematic review and meta-analysis of clinical outcomes and adverse events after revision cartilage restoration procedures of the knee for failed primary cartilage procedures.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

The PubMed, OVID/MEDLINE, and Cochrane databases were queried in August 2023 for trials reporting on the outcomes of revision cartilage restoration procedures of the knee. Information pertaining to rates of failure, reoperations, graft-related complications, and patient-reported outcome measures were extracted. A meta-analysis using inverse-variance proportion models using Freeman-Tukey double-arcsine transformations and DerSimonian-Laird random-effects estimators was constructed to quantitatively describe the cumulative incidence of adverse events.

RESULTS

Sixteen studies (1361 patients; mean age, 35.7 ± 9.3 years) were included. The most frequently performed revision cartilage procedure was autologous chondrocyte implantation (ACI; n = 755 [55.5%]). The overall rate of failure was 25.1% (95% CI, 14.4%-37.3%) at a mean 6.5 years (range, 2-26 years). The majority of studies (n = 9) reported a failure rate exceeding 20%. A significant reduction in failure was observed in favor of the revision osteochondral allograft cohort (19.0% [75/395] vs 35.7% [273/764]; relative risk, 0.63; P < .0001) compared with the revision ACI cohort. The pooled all-cause reoperation event rate was 40.8%, which ranged between 18.2% and 71.4% (13 studies). Of these studies, 12 reported reoperation rates exceeding 20%, and 7 reported rates exceeding 40%. The pooled graft-related complication event rate was 27.2%, which ranged between 5.4% and 56.6% (11 studies). Notably, all analyses demonstrated considerable or moderate heterogeneity, potentially influencing the observed variability in pooled effect estimates.

CONCLUSION

One of every 4 patients may experience a secondary failure after undergoing a revision cartilage procedure. Revision using an osteochondral allograft may confer a meaningful reduction in the risk of failure relative to revision using ACI. High rates of graft-related complications and reoperations are also frequently observed in this population, highlighting the challenge of treating patients with failed primary treatment of chondral or osteochondral defects of the knee.

Hybrid Fixation for Large Unstable Juvenile Osteochondritis Dissecans Lesions: Midterm Results in Adolescent Patients With Completely or Partially Salvageable Progeny Fragment

BACKGROUND

This study aimed to describe the midterm clinical and radiographic outcomes of a hybrid fixation technique (HFT) combining interfragmentary compression with screws and biological support provided by the osteochondral autograft transplantation system (OATS) for treating large unstable juvenile osteochondritis dissecans (JOCD) lesions involving the knee in patients aged ≤18 years.

METHODS

Thirteen patients (15 knees, 9 males) with unstable JOCD lesions in the knee underwent treatment. HFT was indicated for lesions that had a completely salvageable (N=10) or partially salvageable progeny fragment (N=5). Patients were evaluated at a minimum follow-up of 1 year. The mean age of the patients was 15.3 years (range, 11 to 18 y), with 10 lesions involving the medial femoral condyle and 5 involving the lateral femoral condyle. The mean lesion area were 397.7 mm 2 . The outcome measures included the Pedi-IKDC and Tegner activity scales. Radiographic evaluation consisted of assessing osteochondral graft integration using the MOCART score on MRI and determining the degree of osteoarthritis using the Kellgren-Lawrence system (KL).

RESULTS

At a mean follow-up of 51 months (range, 12 to 143 mo), the mean Pedi-IKDC and Tegner activity scale were 90.1±7.2 and 94.7±6.7 points, respectively. Patients with unilateral lesions resumed sports activities on average after 7.7 months (range, 6 to 12 mo). All patients exhibited progeny fragment integration on MRI, with a mean MOCART score of 85±6.5 (range, 75 to 95). Radiographs indicated grade 1 KL joint space in 13 knees and grade 2 in 2 knees. At the last follow-up, 12 patients were asymptomatic, whereas 1 patient experienced occasional mild discomfort during intense physical activity. Six patients required additional surgery for hardware removal, and 1 patient underwent intra-articular loose body removal.

CONCLUSION

The hybrid fixation technique showed promising outcomes in terms of fragment healing and midterm results for unstable JOCD lesions. These findings suggest that HFT can be considered a valid treatment option for large unstable lesions involving the femoral condyles of the knee in adolescents.

STUDY DESIGN

Therapeutic study (level of evidence IV).

Return to Sport in Professional Athletes After Cartilage Restoration Surgery of the Knee: A Systematic Review and Meta-Analysis Demonstrates Gender Inequality and the Need for Improved Reporting

OBJECTIVE

To synthesize the literature concerning return to sport (RTS) and related outcomes after cartilage restoration surgery of the knee in professional athletes.

DESIGN

Cochrane, PubMed, and OVID/Medline databases were queried for data pertaining to RTS after knee cartilage surgery in professional athletes. Demographic information, cartilage lesion characteristics, and RTS-specific information were extracted. Freeman-Tukey Double-Arscine Transformations with Dersimonian-Laerd random-effects estimators were constructed to quantitatively describe the cumulative incidence of RTS, while heterogeneous data described narratively.

RESULTS

Eleven studies (476 athletes; mean age 27.5 ± 2.1 years; 96.6% male) were included. Nine (81.8%) studies investigated a form of microfracture as treatment, with 6 (54.5%) performing isolated microfracture. The remaining studies investigated osteochondral allograft transplantation and mosaicplasty. More than half (n = 6; 54.5%) did not report cartilage lesion location or size. The pooled RTS rate was 84.3% (95% CI: 75.4%-91.8%) at a mean 39.9 (range, 12-104) weeks postoperatively. In 6 studies reporting competition level, a trend toward returning to a lower than pre-injury level was observed. The definition of RTS was only provided in 6 (54.5%) studies, while the criteria for RTS was only reported in 2 (18.2%) studies, suggesting limited transparency. One study reported an objective imaging assessment of reparative tissue, while none reported formal RTS testing protocols or minimum RTS timeline.

CONCLUSION

Although the majority of professional athletes are reported to achieve a successful RTS after cartilage restoration surgery of the knee, the literature predominantly reflects microfracture treatment. Current limitations in this literature include a substantial lack of female representation and infrequent reporting of cartilage lesion characteristics, rehabilitation and RTS criteria, and objective imaging assessments of reparative tissue.

Assessment of Fresh Homologous Osteochondral Transplantation in Knees as a Salvage Treatment: A Prospective Case Series with a Minimum Follow-up Period of 10 Months

Objective  The present study evaluated the clinical outcomes and satisfaction of patients undergoing fresh homologous osteochondral transplantation in the knee as a salvage method. Methods  We analyzed eight knees from seven male patients who underwent fresh homologous osteochondral transplantation by a single surgeon. Their follow-up period ranged from 10 months to 5 years and 5 months. Clinical outcomes included the scores on the International Knee Documentation Committee (IKDC) and on the quality-of-life item of the Knee and Osteoarthritis Outcome Score (KOOS-QoL). Result  The sample consisted of complex cases since all operated knees had undergone previous surgeries. Functional improvement was variable, with six out of the seven operated patients showing statistically significant clinical improvement according to the IKDC score, and a single patient reported being moderately satisfied with the procedure. The quality-of-life item from the KOOS score improved in all patients. There was no failure, need for reintervention, or infection. Conclusion  Fresh homologous osteochondral transplantation is a safe salvage method in our setting to treat large lesions and those with failed previous procedures. Despite the small sample of this case series, most clinical outcomes were positive and had no complications.

Outcomes After Osteochondral Allograft Transplantation of the Medial Femoral Condyle in Patients With Varus and Nonvarus Alignment

BACKGROUND

Fresh osteochondral allograft (OCA) transplantation is an effective technique for the treatment of focal chondral and osteochondral defects in the knee. Coronal-plane malalignment leads to increased contact forces within a compartment and subsequently the cartilage repair site and may lead to higher failure rates. However, the magnitude of the effect of coronal-plane malalignment on graft survivorship and clinical outcomes has not been well characterized.

PURPOSE

To evaluate how varus malalignment affects graft survival and patient-reported outcomes after isolated OCA transplantation of the medial femoral condyle (MFC).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 70 patients (74 knees) who underwent primary OCA transplantation of the MFC between 2005 and 2019 were identified from a prospectively collected single-surgeon cartilage registry with a minimum 2-year follow-up. Coronal-plane alignment was evaluated utilizing standing hip-to-ankle radiographs. OCA failure, defined as removal of the graft or conversion to arthroplasty, and reoperations were recorded. Patient-reported outcomes were obtained preoperatively and postoperatively using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, modified Merle d'Aubigné-Postel score, and overall patient satisfaction score.

RESULTS

The mean mechanical tibiofemoral angle for patients with varus alignment was 3.9° of varus (range, 1.1° to 8.9°) and for patients with nonvarus alignment it was 0.02° of valgus (range, 3.6° varus to 4.6° valgus). Graft survivorship was 95.3% in the varus group and 95.8% in the nonvarus group (P = .918) at 5 years postoperatively. Reoperations after OCA transplantation occurred in 14.0% of the varus group and 22.6% of the nonvarus group (P = .336). The mean International Knee Documentation Committee total score improved from 45.2 preoperatively to 74.8 at latest follow-up in the varus group and from 40.5 preoperatively to 72.3 at latest follow-up in the nonvarus group. Patient satisfaction was >85%.

CONCLUSION

Patients undergoing isolated OCA transplantation of the MFC had high rates (>90%) of graft survivorship and significant improvements in pain and function. Patients with mild preexisting varus malalignment were found to have no difference in the failure rate or clinical outcomes compared with patients with nonvarus alignment.

Knee Joint Preservation in Tactical Athletes: A Comprehensive Approach Based upon Lesion Location and Restoration of the Osteochondral Unit

The unique physical demands of tactical athletes put immense stress on the knee joint, making these individuals susceptible to injury. In order to ensure operational readiness, management options must restore and preserve the native architecture and minimize downtime, while optimizing functionality. Osteochondral lesions (OCL) of the knee have long been acknowledged as significant sources of knee pain and functional deficits. The management of OCL is predicated on certain injury characteristics, including lesion location and the extent of subchondral disease. Techniques such as marrow stimulation, allograft and autologous chondrocyte implantation are examined in detail, with a focus on their application and suitability in tactical athlete populations. Moreover, the restoration of the osteochondral unit (OCU) is highlighted as a central aspect of knee joint preservation. The discussion encompasses the biomechanical considerations and outcomes associated with various cartilage restoration techniques. Factors influencing procedure selection, including lesion size, location, and patient-specific variables, are thoroughly examined. Additionally, the review underscores the critical role of post-operative rehabilitation and conditioning programs in optimizing outcomes. Strengthening the surrounding musculature, enhancing joint stability, and refining movement patterns are paramount in facilitating the successful integration of preservation procedures. This narrative review aims to provide a comprehensive resource for surgeons, engineers, and sports medicine practitioners engaged in the care of tactical athletes and the field of cartilage restoration. The integration of advanced preservation techniques and tailored rehabilitation protocols offers a promising avenue for sustaining knee joint health and function in this demanding population.

Increased kinesiophobia leads to lower return to sport rate and clinical outcomes following osteochondral allograft transplantation of the knee

PURPOSE

The purpose of this study is to describe the postoperative psychological state of patients following osteochondral allograft (OCA) transplantation in the knee and to determine whether patient-perceived kinesiophobia is associated with the rate of return to sport (RTS).

METHODS

A retrospective review of the electronic medical record at a single institution was conducted for all patients that underwent OCA transplantation from January 2010 to 2020. Patient-reported outcomes including the visual analog scale (VAS), knee injury and osteoarthritis outcome score (KOOS) and the Tampa scale of kinesiophobia-11 (TSK-11) were collected. Patients were surveyed regarding their postoperative RTS status.

RESULTS

A total of 38 patients (52.6% female) were included in our analysis. Overall, 24 patients (63.2%) returned to sport with 12 (50%) of these patients returning at a lower level of play. When comparing patients that return to sport to those that did not, patients that return had significantly superior KOOS pain (p = 0.019) and KOOS QOL (p = 0.011). Measures of kinesiophobia (TSK-11) were significantly higher among patients that did not return to sport (p = 0.014), while satisfaction (n.s.) and pain intensity (n.s.) were comparable between groups. Logistic regression models controlling for demographic factors, VAS pain scores and lesion size showed that for every one-point increase in TSK-11 kinesiophobia score, patients were 1.33 times more likely to return to sport at a lower level (p = 0.009). For every one-point increase in TSK-11 scores KOOS QOL decreased by 2.4 points (p < 0.001).

CONCLUSION

Fear of reinjury decreases the likelihood that patients will return to their preoperative level of sport after OCA transplantation. Patients that do not return to sport report significantly greater fear of reinjury and inferior clinical outcomes, despite similar levels of satisfaction and pain compared to those that return.

LEVEL OF EVIDENCE

Level III.

Outcomes and Return to Sport After Knee Osteochondral Allograft Transplant in Professional Athletes

Background

Limited data are available on the outcomes and return-to-sport rates after osteochondral allograft transplant in professional athletes.

Purpose

To evaluate the experience of a single senior surgeon in treating professional athletes with osteochondral allograft transplant, including analyzing clinical outcomes and return to sport.

Study Design

Case series; Level of evidence, 4.

Methods

The authors performed a retrospective review of professional athletes treated with primary osteochondral allograft to the knee between January 1, 2001, and January 1, 2021, by a single surgeon. Athletes were required to play at the professional level in their sport and have a minimum of 2 years of follow-up. Return-to-sport rates and timing were evaluated. Patient-reported outcomes were assessed preoperatively and at final follow-up. Reoperations and failures were also tabulated.

Results

The study included 15 professional athletes who represented a variety of sports, with follow-up at a mean of 4.91 ± 2.2 years (range, 2.0-9.4 years). The majority (8 athletes; 53%) had undergone prior surgeries to the operative knee. Eleven (73%) returned to sport at a mean of 1.22 ± 0.4 years (range, 0.75-2 years), and of the 8 undergoing isolated osteochondral allograft, 7 (87.5%) returned at 1.28 ± 0.3 years. Ten athletes (66.7% of total; 90.9% of those who returned) returned to sport at the same level or higher compared with before surgery. Significant improvements were seen in each assessed patient-reported outcome score at final follow-up. Two of the 3 (66.7%) patients who underwent concomitant meniscal allograft transplant were able to return to sport at the same level or higher than presurgery. Three (20%) underwent second-look arthroscopy, 1 (6.7%) of whom underwent cartilage debridement of the osteochondral allograft.

Conclusion

Osteochondral allograft transplant in professional athletes can result in a high rate of return to play at a similar or higher level as presurgery, even when performed with concomitant procedures such as meniscal allograft transplant. High-level athletes should expect significant postoperative improvement in clinical outcomes.

Return to Play After Knee Articular Cartilage Restoration: Surgical Options, Rehabilitation Protocols, and Performance Outcomes

PURPOSE OF REVIEW

Numerous cartilage restoration techniques have proven to be effective in the treatment of articular cartilage defects. The ultimate goal of these procedures is to improve pain and function, thereby increasing the likelihood of a patient's return to physical activity. Postoperative rehabilitation is a key component for a successful and expedient return to activities. The purpose of this article is to review the current literature regarding common surgical options, rehabilitation protocols, and performance outcomes after operative treatment of articular cartilage defects.

RECENT FINDINGS

Studies have demonstrated improved short- to long-term outcomes in a majority of techniques. However, the clinical benefits of microfracture are short-lived, which has led to the use of alternative procedures. Rehabilitation protocols are not standardized, but emphasis has been placed on bracing, weightbearing, early continuous passive range of motion, and strengthening to improve function. There is growing evidence to suggest that accelerated rehabilitation after matrix-induced autologous chondrocyte implantation may result in superior outcomes compared to delayed rehabilitation. Overall, most techniques result in satisfactory rates of return to play, though existing comparative studies typically include patients with heterogeneous pathology, complicating effective synthesis of outcomes data. In appropriately selected patients, cartilage restoration procedures after articular cartilage injury result in favorable patient-reported clinical outcomes and high rates of return to play. While studies emphasize the critical role that rehabilitation plays with respect to outcomes after surgery, there are substantial inconsistencies in protocols across techniques.

Isolated Osteochondral Autograft Versus Allograft Transplantation for the Treatment of Symptomatic Cartilage Lesions of the Knee: A Systematic Review and Meta-analysis

BACKGROUND

Focal cartilage lesions of the knee remain a difficult entity to treat. Current treatment options include arthroscopic debridement, microfracture, autograft or allograft osteochondral transplantation, and cell-based therapies such as autologous chondrocyte transplantation. Osteochondral transplantation techniques restore the normal topography of the condyles and provide mature hyaline cartilage in a single-stage procedure. However, clinical outcomes comparing autograft versus allograft techniques are scarce.

PURPOSE

To perform a comprehensive systematic review and meta-analysis of high-quality studies to evaluate the results of osteochondral autograft and allograft transplantation for the treatment of symptomatic cartilage defects of the knee.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 2.

METHODS

A comprehensive search of the literature was conducted using various databases. Inclusion criteria were level 1 or 2 original studies, studies with patients reporting knee cartilage injuries and chondral defects, mean follow-up ≥2 years, and studies focusing on osteochondral transplant techniques. Exclusion criteria were studies with nonknee chondral defects, studies reporting clinical outcomes of osteochondral autograft or allograft combined with other procedures, animal studies, cadaveric studies, non-English language studies, case reports, and reviews or editorials. Primary outcomes included patient-reported outcomes and failure rates associated with both techniques, and factors such as lesion size, age, sex, and the number of plugs transplanted were assessed. Metaregression using a mixed-effects model was utilized for meta-analyses.

RESULTS

The search resulted in 20 included studies with 364 cases of osteochondral autograft and 272 cases of osteochondral allograft. Mean postoperative survival was 88.2% in the osteochondral autograft cohort as compared with 87.2% in the osteochondral allograft cohort at 5.4 and 5.2 years, respectively (P = .6605). Patient-reported outcomes improved by an average of 65.1% and 81.1% after osteochondral autograft and allograft, respectively (P = .0001). However, meta-analysis revealed no significant difference in patient-reported outcome percentage change between osteochondral autograft and allograft (P = .97) and a coefficient of 0.033 (95% CI, -1.91 to 1.98). Meta-analysis of the relative risk of graft failure after osteochondral autograft versus allograft showed no significant differences (P = .66) and a coefficient of 0.114 (95% CI, -0.46 to 0.69). Furthermore, the regression did not find other predictors (mean age, percentage of female patients, lesion size, number of plugs/grafts used, and treatment location) that may have significantly affected patient-reported outcome percentage change or postoperative failure between osteochondral autograft versus allograft.

CONCLUSION

Osteochondral autograft and allograft result in favorable patient-reported outcomes and graft survival rates at medium-term follow-up. While predictors for outcomes such as mean age, percentage of female patients, lesion size, number of plugs/grafts used, and treatment location did not affect the comparison of the 2 cohorts, proper patient selection for either procedure remains paramount to the success and potentially long-term viability of the graft.

The Large Focal Isolated Chondral Lesion

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

Osteochondral Allograft Transplantation

Background:

Articular cartilage lesions are a significant cause of morbidity and impaired knee function, and attempts to surgically repair damaged cartilage have failed to reliably reproduce native cartilage. Thus, osteochondral allograft transplantation is an effective one-step procedure to repair large cartilage defects.

Indications:

Osteochondral allograft transplantation is indicated for young active patients with large focal defects, those with a history of previous cartilage repair, and those with cartilage-related degenerative disorders such as osteonecrosis, osteochondritis dissecans, and/or post-traumatic osteochondral defects.

Technique Description:

In short, after the focal chondral defect is identified, a socket is created with specific dimensions in depth and diameter. The donor cartilage is then secured in a graft station, and a sizing guide is placed through a bushing to confirm the allograft harvest location. Using stabilization from the graft station arm, a coring reamer is then advanced through the donor cartilage, and a saw is used to allow for easy removal of the graft from the donor condyle. The plug is then fashioned to fit the exact dimensions of the socket created earlier in the procedure. A cut on the donor plug is made to fashion the plug to the appropriate depth. A rongeur is used to make the plug more bullet shaped at the end to allow the plug to enter the socket more easily. Small holes are then drilled into the base of the socket to help promote incorporation of the plug into the socket during the healing process. After the socket is irrigated, the plug is then placed into the socket, and a tamp is used to gently tap the cartilage until it is flush with the surrounding surface.

Results:

After an appropriate rehabilitation protocol is followed for up to 10 months postoperatively, osteochondral allograft transplantation allows for near-to-complete restoration of patient functionality and strength, with return to full activity possible within 1 year.

Conclusion:

Acute repair of large focal chondral defects is effective in restoring knee strength and functionality and is associated with high patient satisfaction. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Osteochondral Allograft Transplantation for Focal Cartilage Defects of the Femoral Condyles

Focal cartilage defects of the knee are painful and difficult to treat, especially in younger patients¹. Seen in up to 60% of patients who undergo knee arthroscopy², chondral lesions are most common on the patella and medial femoral condyle³. Although the majority of lesions are asymptomatic, a variety of treatment options exist for those that are symptomatic; however, no clear gold-standard treatment has been established. In recent years, osteochondral allograft transplantation has been increasingly utilized because of its versatility and encouraging outcomes^4-7. The procedure entails replacing damaged cartilage with a graft of subchondral bone and cartilage from a deceased donor. Indications for this procedure include a symptomatic, full-thickness osteochondral defect typically ≥2 cm² in size in someone who has failed conservative management. Relative indications include patient age of <40 years and a unipolar defect^8,9.

Description

Osteochondral allograft transplantation requires meticulous planning, beginning with preoperative radiographs to evaluate the patient's alignment, estimate the lesion size, and aid in matching of a donor femoral condyle. The procedure begins with the patient supine and the knee flexed. A standard arthrotomy incision is performed on the operative side. Once exposure is obtained, a bore is utilized to remove host tissue from the lesion typically to a depth of 5 to 8 mm. Measurements are taken and the donor condyle is appropriately sized to match. A coring reamer is utilized to create the plug from donor tissue, which is trimmed to the corresponding depth. After marrow elements are removed via pulse lavage, the allograft plug is placed within the femoral condyle lesion through minimal force.

Alternatives

Nonoperative treatment involves a reduction in high-impact activities and physical therapy. Surgical alternatives include chondroplasty, microfracture, and osteochondral autograft transplantation; however, these options are typically performed for smaller lesions (<2 cm). For larger lesions (≥2 cm), matrix-induced autologous chondrocyte implantation (MACI) can be utilized, but requires 2 surgical procedures.

Rationale

Osteochondral allograft transplantation is selected against other procedures for various reasons related to patient goals, preferences, and expectations. Typically, this procedure is favored over microfracture or autograft transplantation when the patient has a large lesion. Allograft transplantation might be favored over MACI because of patient preference for a single surgical procedure instead of 2.

Expected Outcomes

To our knowledge, there are currently no Level-I or II trials comparing osteochondral allograft transplantation against other treatments for cartilage defects. There are, however, many systematic reviews of case studies and cohorts that report on outcomes. A 2016 review of 291 patients showed significantly improved patient-reported outcomes at a mean follow-up of 12.3 years^5,9. The mean survival of grafts was 94% at 5 years and 84% at 10 years⁵. Overall, data on long-term survival are lacking because interest in and use of this procedure have only increased over the past few decades¹⁰. Finally, the rate of return to sport is promising, with the systematic review by Campbell et al. showing rates as high as 88% with an average time to return to sport of 9.6 months¹¹. Postoperatively, patients can expect to immediately begin passive range of motion. Progression of heel-touch weight-bearing begins at 6 weeks, and patients may return to sport-specific activity after 8 months, as tolerated.

Important Tips

Ensure that the allograft is of adequate quality and is size-matched prior to performing the surgical procedure.The cannulated cylinder should be perpendicular to both the host lesion and graft tissue in order to ensure symmetric estimations of size.Save subchondral bone shavings when preparing the host lesion. These can be utilized to take up space if your graft depth is not sufficient to fill the host defect.Utilize saline solution irrigation judiciously when reaming out the host tissue and graft plug.

Acronyms & Abbreviations

AAROM = active-assisted range of motionACI = autologous chondrocyte implantationAP = anteroposteriorBMI = body mass indexCPM = continuous passive range of motionGlut/glutes = gluteal musclesHTO = high tibial osteotomyICRS = International Cartilage Repair SocietyLFC = lateral femoral condyleLTP = lateral tibial plateauMACI = matrix-induced autologous chondrocyte implantationMFC = medial femoral condyleMobs = mobilizationMRI = magnetic resonance imagingNSAIDs = non-steroidal anti-inflammatory drugsOAT = osteochondral allograft transplantationPROM = passive range of motionQuad = quadriceps musclesROM = range of motionSLR = straight leg raise.

Osteochondral Allografts in Knee Surgery: Narrative Review of Evidence to Date

Knee articular cartilage defects can result in significant pain and loss of function in active patients. Osteochondral allograft (OCA) transplantation offers a single-stage solution to address large chondral and osteochondral defects by resurfacing focal cartilage defects with mature hyaline cartilage. To date, OCA transplantation of the knee has demonstrated excellent clinical outcomes and long-term survivorship. However, significant variability still exists among clinicians with regard to parameters for graft acceptance, surgical technique, and rehabilitation. Technologies to optimize graft viability during storage, improve osseous integration of the allograft, and shorten recovery timelines after surgery continue to evolve. The purpose of this review is to examine the latest evidence on treatment indications, graft storage and surgical technique, patient outcomes and survivorship, and rehabilitation after surgery.

Fresh Osteochondral Allograft Transplantation in Osteochondritis Dissecans in the Knee Joint

Osteochondritis dissecans (OCD) is a chronic and painful joint condition that can occur from childhood through to adult life. Microtrauma, vascular insufficiency, or abnormal endochondral ossification are the most common causes of OCD. Reconstructive techniques for OCD of the knee are typically necessary when either non-operative or reparative/regenerative operative treatments fail, or when the OCD is irreversible. To analyze the clinical outcomes and failure rates of fresh osteochondral allograft transplantation (FOCA) used as a reconstructive strategy in OCD patients, an in-depth search was carried out on the PubMed, Scopus, and Web of Science databases concerning the existing evidence related to the use of FOCA for OCD patients in the knee joint. A total of 646 studies were found through the search and 2 studies were added after a cross-referenced examination of the articles within the bibliography. Six studies with a total of 303 OCD lesions treated with FOCA, with a mean follow-up of 6.3 years, were included. Although a limited number of low-level evidence studies on this topic are available in previous research, satisfactory clinical results and survival rates of the reconstruction are reported. However, to better define the real advantages of FOCA in the healing process of OCD lesions, comparative studies with different techniques are needed.

Targeted treatment for osteoarthritis: drugs and delivery system

The management of osteoarthritis (OA) is a clinical challenge due to the particular avascular, dense, and occluded tissue structure. Despite numerous clinical reports and animal studies, the pathogenesis and progression of OA are still not fully understood. On the basis of traditional drugs, a large number of new drugs have been continuously developed. Intra-articular (IA) administration for OA hastens the development of targeted drug delivery systems (DDS). OA drugs modification and the synthesis of bioadaptive carriers contribute to a qualitative leap in the efficacy of IA treatment. Nanoparticles (NPs) are demonstrated credible improvement of drug penetration and retention in OA. Targeted nanomaterial delivery systems show the prominent biocompatibility and drug loading-release ability. This article reviews different drugs and nanomaterial delivery systems for IA treatment of OA, in an attempt to resolve the inconsonance between in vitro and in vivo release, and explore more interactions between drugs and nanocarriers, so as to open up new horizons for the treatment of OA.

ACL Study Group presents the global trends in ACL reconstruction: biennial survey of the ACL Study Group

OBJECTIVES

The primary objective of this survey was to gauge the current global trends in anterior cruciate ligament reconstruction (ACLR) as reported by the members of the Anterior Cruciate Ligament (ACL) Study Group (SG).

METHODS

A survey was created and distributed among the members of the ACL SG consisting of 87 questions and 16 categories related to ACLR, including member demographics, preoperative management, primary ACLR techniques and graft choice, use of concomitant procedures and biological augmentation, postoperative rehabilitation, and more.

RESULTS

The survey was completed by the 140 members of the ACL SG. Fifty per cent of members are from Europe, 29% from the USA, 15% from the Asia-Pacific and the remaining 6% are from Latin America, the Middle East, New Zealand and Africa. Most (92%) do not believe there is a role for non-operative management of ACL tears in higher level athletes; conversely, most agree there is a role for non-operative management in lower impact athletes (92%). A single-bundle (90%) technique with hamstring autograft (53%) were most common for primary ACLR. Tunnel position varied among respondents. Sixty-one per cent do not use allograft for primary ACLR. Fifty per cent of respondents use cortical suspensory fixation on the femur, with variable responses on the tibia. Most (79%) do not use biologics in primary ACLR, while 83% think there is a selective role for extra-articular augmentation in primary ACLR. Fifty per cent prefer bone-tendon-bone autograft for revision ACLR and extra-articular augmentation is more commonly used (13% always, 26% often) than in primary ACLR (0% always, 15% often). A majority (53%) use a brace after primary ACLR. The most common responses for minimal time to return to play after primary ACLR were 6-8 months (44%) and 8-12 months (41%).

CONCLUSION

We presented the thoughts and preferences of the ACL SG on the management of ACL injuries. This survey will help to facilitate an ongoing discussion with regard to ACLR by providing global insights into the current surgical trends in ACLR.

LEVEL OF EVIDENCE

Level V, Expert Opinion.

Osteochondral Allograft Transplantation in Professional Athletes: Rehabilitation and Return to Play

For the treatment of large chondral and osteochondral defects of the knee, osteochondral allograft transplantation (OCA) is an effective solution with relatively high rates of return to sport. In professional athletes, rehabilitation following OCA is a critical component of the process of returning the athlete to full sports activity and requires a multidisciplinary team approach with frequent communication between the surgical and rehabilitation teams (physical therapists, athletic trainers, coaching staff). In this review, we describe our five-phase approach to progressive rehabilitation of the professional athlete after OCA, which takes into account the biological processes of healing and optimization of neuromuscular function required for the demands of elite-level sport. The principles of early range of motion, proper progression through the kinetic chain, avoidance of pain and effusion, optimization of movement, regimen individuation, and integration of sports-specific activities underlie proper recovery.

Osteochondral Lesions of the Distal Tibial Plafond: A Systematic Review of Lesion Locations and Treatment Outcomes

BACKGROUND

Osteochondral lesions of the tibial plafond (OLTPs) remain less common than osteochondral lesions of the talus (OLTs), but recognition of the condition has increased.

PURPOSE

To systematically evaluate the literature on lesion locations and treatment outcomes of OLTPs, whether in isolation or in combination with OLTs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A search was performed using the PubMed, Embase, and CINAHL databases for studies on lesion locations or with imaging or treatment outcomes of OLTPs. Case reports and reports based on expert opinion were excluded. Lesion locations as well as outcome measure results were aggregated. The Methodological Index for Non-randomized Studies score was used to assess methodological quality when applicable.

RESULTS

Included in this review were 10 articles, all published in 2000 or later. Most studies were evidence level 4, and the mean Methodological Index for Non-randomized Studies score was 8.6 (range, 8-10). Overall, 174 confirmed OLTP cases were identified, and the mean patient age was 38.8 years. Of the 157 lesions with confirmed locations, the most common was central-medial (32/157; 20.4%). Of 6 studies on treatment outcomes, all but 1 evaluated bone marrow stimulation techniques. Microfracture of small lesions (<150 mm2) was the most common treatment utilized. Imaging and functional outcomes appeared favorable after treatment. The data did not support differences in outcomes between isolated OLTPs and OLTPs with coexisting OLTs.

CONCLUSION

Osteochondral lesions of the distal tibia most commonly occurred at the central-medial tibial plafond. Microfracture of small lesions was the most common treatment utilized, and clinical and magnetic resonance imaging results were favorable, although data were heterogeneous. Areas for future research include the following: the effect of patient factors and additional pathologies on outcomes; larger or deeper lesion treatment; more direct comparisons of outcomes between kissing or coexisting lesions and isolated lesions; and head-to-head comparison of treatments, such as microfracture, bone marrow-derived cell transplantation, and osteochondral autografts/allografts.

Return to Sport After Large Single-Surface, Multisurface, or Bipolar Osteochondral Allograft Transplantation in the Knee Using Shell Grafts

Background:

Return to sport (RTS) after osteochondral allograft (OCA) transplantation for large unipolar femoral condyle defects has been consistent, but many athletes are affected by more severe lesions.

Purpose:

To examine outcomes for athletes who have undergone large single-surface, multisurface, or bipolar shell OCA transplantation in the knee.

Study Design:

Case series; Level of evidence, 4.

Methods:

Data from a prospective OCA transplantation registry were assessed for athletes who underwent knee transplantation for the first time (primary transplant) between June 2015 and March 2018 for injury or overuse-related articular defects. Inclusion criteria were preinjury Tegner level ≥5 and documented type and level of sport (or elite unit active military duty); in addition, patients were required to have a minimum of 1-year follow-up outcomes, including RTS data. Patient characteristics, surgery type, Tegner level, RTS, patient-reported outcome measures (PROMs), compliance with rehabilitation, revisions, and failures were assessed and compared for statistically significant differences.

Results:

There were 37 included athletes (mean age, 34 years; range, 15-69 years; mean body mass index, 26.2 kg/m²; range, 18-35 kg/m²) who underwent large single-surface (n = 17), multisurface (n = 4), or bipolar (n = 16) OCA transplantation. The highest preinjury median Tegner level was 9 (mean, 7.9 ± 1.7; range, 5-10). At the final follow-up, 25 patients (68%) had returned to sport; 17 (68%) returned to the same or higher level of sport compared with the highest preinjury level. The median time to RTS was 16 months (range, 7-26 months). Elite unit military, competitive collegiate, and competitive high school athletes returned at a significantly higher proportion (P < .046) than did recreational athletes. For all patients, the Tegner level at the final follow-up (median, 6; mean, 6.1 ± 2.7; range, 1-10) was significantly lower than that at the highest preinjury level (P = .007). PROMs were significantly improved at the final follow-up compared with preoperative levels and reached or exceeded clinically meaningful differences. OCA revisions were performed in 2 patients (5%), and failures requiring total knee arthroplasty occurred in 2 patients (5%), all of whom were recreational athletes. Noncompliance was documented in 4 athletes (11%) and was 15.5 times more likely (P = .049) to be associated with failure or a need for revision than for compliant patients.

Conclusion:

Large single-surface, multisurface, or bipolar shell OCA knee transplantations in athletes resulted in two-thirds of these patients returning to sport at 16 to 24 months after transplantation. Combined, the revision and failure rates were 10%; thus, 90% of patients were considered to have successful 2- to 4-year outcomes with significant improvements in pain and function, even when patients did not RTS.

Return-to-Sport Review for Current Cartilage Treatments

The return to play outcome is an important measure for orthopaedic sports medicine treatments. This variable is especially important when discussing cartilage treatments because there are many different cartilage options available to athletes with articular injuries and this population is particularly interested in the ability to return to activities. Although many outcome variables are considered in any surgical procedure, the return-to-sport variable is focused on an active population and can be tailored to that patient's sport-specific goals. In this article, we will review some of the most recent and up-to-date articles describing return-to-sport outcomes for various knee cartilage treatments. This article will focus on the most common current knee cartilage treatments including microfracture, autologous chondrocyte implantation, osteochondral autograft transplant, and osteochondral allograft transplantation.

Management of Large Focal Chondral and Osteochondral Defects in the Knee

Large, focal articular cartilage defects of the knee (> 4 cm²) can be a source of significant morbidity and often require surgical intervention. Patient- and lesion-specific factors must be identified when evaluating a patient with an articular cartilage defect. In the management of large cartilage defects, the two classically utilized cartilage restoration procedures are osteochondral allograft (OCA) transplantation and cell therapy, or autologous chondrocyte implantation (ACI). Alternative techniques that are available or currently in clinical trials include a hyaluronan-based scaffold plus bone marrow aspirate concentrate, a third-generation autologous chondrocyte implant, and an aragonite-based scaffold. In this review, we will focus on OCA and ACI as the mainstay in management of large chondral and osteochondral defects of the knee. We will discuss the techniques and associated clinical outcomes for each, while including a brief mention of alternative treatments. Overall, cartilage restoration techniques have yielded favorable clinical outcomes and can be successfully employed to treat these challenging large focal lesions.

Fresh Osteochondral Allograft Transplants in the Knee: Bipolar and Beyond

Knee patients who have sustained chondral and osteochondral lesions suffer from debilitating pain, which can ultimately lead to posttraumatic osteoarthritis and whole-joint disease. Older, nonactive patients are traditionally steered toward total knee arthroplasty (TKA), but younger, active patients are not good candidates for TKA based on implant longevity, complications, morbidity, and risk for revision, such that treatment strategies at restoring missing hyaline cartilage and bone are highly desired for this patient population. Over the past four decades, fresh osteochondral allograft (OCA) transplantation has been developed as a treatment method for large (> 2.5 cm²) focal full-thickness articular cartilage lesions. This article documents our own institutional OCA journey since 2016 through enhanced graft preservation techniques (the Missouri Osteochondral Preservation System, or MOPS), technical improvements in surgical techniques, use of bone marrow aspirate concentrate, bioabsorbable pins and nails, and prescribed and monitored patient-specific rehabilitation protocols. Further follow-up with documentation of long-term outcomes will provide insight for continued optimization for future applications for OCA transplantation, potentially including a broader spectrum of patients appropriate for this treatment. Ongoing translational research is necessary to blaze the trail in further optimizing this treatment option for patients.

Return to Sport Following High Tibial Osteotomy With Concomitant Osteochondral Allograft Transplantation

BACKGROUND

Young patients with symptomatic chondral defects in the medial compartment with varus malalignment may undergo opening wedge high tibial osteotomy (HTO) with concomitant osteochondral allograft transplantation (OCA) (HTO + OCA). Although patients have demonstrated favorable outcomes after HTO + OCA, limited information is available regarding return to sporting activities after this procedure.

PURPOSE

To evaluate (1) the timeline to return to sports (RTS), (2) patient satisfaction, and (3) reasons for discontinuing sporting activity after HTO + OCA, and to identify predictive factors of RTS.

STUDY DESIGN

Case series; level of evidence, 4.

METHODS

Consecutive patients who underwent HTO + OCA for varus deformity and medial femoral condyle focal chondral defects with a minimum 2-year follow-up were retrospectively reviewed. Patients completed a subjective sports questionnaire, satisfaction questionnaire, visual analog scale for pain, and Single Assessment Numerical Evaluation.

RESULTS

Twenty-eight patients with a mean age of 36.97 ± 7.52 years were included at mean follow-up of 6.63 ± 4.06 years. Fourteen patients (50.0%) required reoperation during the follow-up period, with 3 (10.7%) undergoing knee arthroplasty. Twenty-four patients participated in sports within 3 years before surgery, with 19 patients (79.2%) able to return to at least 1 sport at a mean 11.41 ± 6.42 months postoperatively. However, only 41.7% (n = 10) were able to return to their preoperative level. The most common reasons for sports discontinuation (n = 20; 83.3%) were a desire to prevent further damage to the knee (70.0%), persistent pain (55.0%), persistent swelling (30.0%), and fear (25.0%).

CONCLUSION

In young, active patients with varus deformity and focal medial femoral condyle chondral defects, HTO + OCA enabled 79.2% of patients to RTS by 11.41 ± 6.42 months postoperatively. However, only 41.7% of patients were able to return to their preinjury level or better. It is imperative that patients be appropriately educated to manage postoperative expectations regarding sports participation after HTO + OCA.

Return to Work Following High Tibial Osteotomy With Concomitant Osteochondral Allograft Transplantation

PURPOSE

To assess the timeline of return to work (RTW) following opening-wedge high tibial osteotomy (HTO) with concomitant osteochondral allograft transplantation (OCA) of the medial femoral condyle.

METHODS

Consecutive patients undergoing HTO + OCA due to focal chondral deficiency and varus deformity were retrospectively identified and reviewed at a minimum of 2 years following surgery. Patients completed a subjective work questionnaire, a visual analog scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire.

RESULTS

Twenty-eight patients (average age: 36.0 ± 7.9 years) were included at 6.7 ± 4.1 years postoperatively. Twenty-six patients were employed before surgery and 25 patients (96.2%) returned to work following HTO + OCA. However, only 88.5% of patients were able to return to the same level of occupational intensity by 3.5 ± 2.9 months postoperatively. The rate of RTW to the same occupational intensity for sedentary, light, medium, and heavy intensity occupations was 100%, 100%, 88.9%, and 80% (P = .8), whereas the duration of RTW was 9.0 ± 7.1 months, 1.7 ± 1.4 months, 2.7 ± 0.9 months, and 4.2 ± 1.9 months (P = .006), respectively. Two patients (7.7%) underwent knee replacement by 5.3 ± 3.1 years postoperatively due to progression of osteoarthritis in the medial compartment.

CONCLUSIONS

In patients with focal chondral deficiency and varus deformity, HTO + OCA provides a high rate of RTW (96.2%) by 3.5 ± 2.9 months postoperatively. However, patients with greater-intensity occupations may take longer to return to work than those with less physically demanding occupations.

LEVEL OF EVIDENCE

IV, Retrospective Case Series.

Editorial Commentary: Are We Really Ready to Talk About Sports After Osteochondral Allograft Transplantation?

When it comes to return to high-level sports participation, articular cartilage surgical treatment outcomes were historically abysmal, whereas osteochondral allografts have allowed return to sport at rates as high as 88%. However, although osteochondral allograft transplantation effectively reconstructs the damaged articular surface in affected knees, the grafts themselves do nothing to re-establish normal joint homeostasis, resulting in high reoperation rates. Return to sport should require recovery of nearly normal motion and strength, as well as magnetic resonance imaging showing intact cartilage, bony incorporation, and no effusion. These milestones typically occur at 6 months. Persistent joint inflammation and reactivity remain a vexing issue, and long-term durability is of significant concern. In the future, a goal could be to develop biological therapies that could modulate the joint inflammation and catabolism associated with articular cartilage injury.